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FIELD OF THE INVENTION
[0001] This invention relates to processes for coating sewing thread, and in particular to processes for coating sewing thread using solventless systems.
BACKGROUND OF THE INVENTION
[0002] Sewing thread is typically constructed from multiple continuous filament multifilament plies which are individually twisted in one direction and then combined by twisting in the opposite direction to produce a multiple ply final thread. In general, this causes the separate plies to act as a single unitary ply during the sewing process.
[0003] In many highly demanding industrial environments, it can be necessary to further treat sewing thread prior to its use. Such treatments can improve the integrity and retention of individual filaments within the sewing thread under conditions of high abrasion, improve the adhesion of the plies or individual filaments to each other in monocord or multicord constructions, and improve durability of the thread in its final end use. In these instances, the thread is coated with a bonding agent in the form of a lacquer or other plastic material which essentially forms a solid yet flexible film or sheath surrounding the thread. This allows the thread to retain substantial flexibility because the individual filaments of the thread retain the ability to have some movement relative to each other.
[0004] If the bonding agent fully penetrates the cross-section of the thread, however, the individual filaments are bound to each other and a stiff thread results. Such a stiff thread performs similar to a monofilament thread and can be unacceptable for many end use applications.
[0005] Conventionally, sewing thread is coated by passing the thread through a suitable resin in a solvent and then through a heating oven which evaporates the solvent and leaves the film. This operation, however, can be slow and releases organic solvent materials into the atmosphere. In addition, the film or sheath tends to flake off the sewing thread when used in demanding applications. The flaking is highly undesirable because it produces a visible dandruff-like deposit on the product. Further, energy required to remove the solvent can increase production costs.
[0006] Solventless systems can avoid many problems associated with solvent based coatings. In an exemplary solventless system, sewing thread is coated with a prepolymer material (such as a monomer plus a catalyst) which is capable of reacting to form a film when exposed to ultraviolet (UV) radiation. However, radiation curable systems also tend to flake off the sewing thread when the sewing thread is used in demanding applications. Other problems which can be associated with the use of many solventless systems include incomplete cure, tackiness, low adhesion and low production speeds.
SUMMARY OF THE INVENTION
[0007] The present invention provides processes for coating sewing thread using solventless systems. The solventless systems are generally more environmentally acceptable than conventional solvent based systems. In addition, the solventless systems can be applied to the thread and then cured in an in-line process at a greatly increased rate as compared to solvent based processes, which can reduce production costs. Solvent or water does not have to be removed from the solventless system after coating, thus reducing energy costs. In addition, sewing thread can be coated using smaller sized equipment, thus reduction production space.
[0008] In contrast to prior solventless systems, however, the coated sewing thread exhibits improved resistance to flaking and powdering. In addition, the coated sewing threads of the invention can have excellent adhesion properties which can protect the thread surface during demanding high speed industrial applications.
[0009] In the invention, a radiation curable material or resin system is applied in-line to a continuous threadline. When the thus coated thread is exposed to radiation, the radiation initiates polymerization or cure of the resin. In contrast to prior solventless systems, however, the radiation initiates a reaction that is self sustaining following initiation, as explained below.
[0010] Preferably, the radiation curable system is a cationic initiated system in which the radiation initiates a self sustaining crosslinking reaction following initiation, in contrast to many radiation cured polymers which are based upon a free radical mechanism. In the latter type mechanism, it is currently believed that the reaction only proceeds in the presence of UV radiation. However, in the case of a sewing thread, it is believed that at least a portion of the resin applied to the thread is shielded from the UV radiation by the individual filaments in the thread. Thus, for free radical initiated UV resins, the shielded portion of the resin is never fully reacted and hardened.
[0011] In contrast, for cationic initiated resins, the shielded portion of the resin is hardened as a result of the self sustaining thermal reaction initiated by the UV radiation even though the shielded portion of the resin is never irradiated directly. As a result, the cationic initiated systems cure or react more completely and as a result do not suffer from the tacking and flaking problems associated with free radical radiation curable resins.
[0012] In the invention, to coat the sewing thread, the sewing thread is passed through a cavity in a coating apparatus which contains the radiation curable material under pressure. The radiation curable material is applied to the thread in the cavity using a “contact coating” process in which the pressurized radiation curable resin is applied to the exterior of the sewing thread as the sewing thread is contacted by a surface so as to impregnate resin into the periphery of the sewing thread. In one embodiment of the invention, contact coating is achieved by employing a coating die having an orifice of smaller diameter than the diameter of the sewing thread. Alternatively, a deformable porous media can be provided in the die cavity so that it surrounds and contacts the sewing thread as it passes through the cavity. As a result of contact coating, the resultant sewing thread exhibits a thin layer of radiation curable material that has been impregnated into the periphery of the sewing thread.
[0013] Following curing of the radiation curable coating, the sewing thread of the invention differs structurally from conventional organic solvent based coated sewing thread because the radiation curable composition is applied so that the composition penetrates into the periphery of the sewing thread, preferably to a depth of one to about three single filament layers (or diameters), and the peripheral filaments are bonded to each other and in some cases to the next interior level of filaments. Although the composition penetrates the thread, the degree of penetration is controlled to prevent the thread from becoming unduly stiff. Thus, a continuous sheath of resin is not formed around the sewing thread, in contrast with conventional coated sewing thread; instead, the coating extends into the periphery of the thread. This can advantageously minimize or prevent stripping of the coating caused by abrasive forces such as are encountered in sewing processes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Some of the features and advantages of the invention having been described, others will become apparent from the detailed description which follows, and from the accompanying drawings, in which:
[0015] [0015]FIG. 1 is a top view of an exemplary apparatus for coating sewing thread in accordance with the invention;
[0016] [0016]FIG. 2 is a side view of the apparatus of FIG. 1;
[0017] [0017]FIG. 3 is a cross sectional view of a sewing thread coating apparatus of the apparatus of FIG. 1, taken along line 3 - 3 thereof;
[0018] [0018]FIG. 4 is a partially broken top view of the coating apparatus of FIG. 3, taken along line 4 - 4 thereof;
[0019] [0019]FIG. 5 is an enlarged top view of the broken away portion of the apparatus of FIG. 4 illustrating a resin reservoir therein;
[0020] [0020]FIG. 6 is a greatly enlarged cross-sectional view of a cavity of the coating apparatus of FIG. 3, taken along line 6 - 6 thereof;
[0021] [0021]FIG. 7 is a greatly enlarged cross-sectional view of an alternative embodiment of a cavity of the coating apparatus of FIG. 3 illustrating the use of a porous, deformable contact media in the cavity;
[0022] [0022]FIG. 8 a cross-sectional view of an ultraviolet (UV) radiation curing chamber of the apparatus of FIG. 1, taken along line 8 - 8 thereof;
[0023] [0023]FIG. 9 is a top view of the UV radiation curing chamber of FIG. 8, taken along line 9 - 9 thereof;
[0024] [0024]FIG. 10 is cross-sectional end view of the UV radiation curing chamber of FIG. 8, taken along line 10 - 10 thereof;
[0025] [0025]FIGS. 11, 12 and 13 are photographs illustrating a perspective view of a coated sewing thread of the invention and further illustrate penetration of the coating into the periphery of the sewing thread;
[0026] [0026]FIG. 14 is a photograph illustrating a perspective view of a sewing thread prepared using a conventional solvent based coating system and illustrates how the conventional coating surrounds the thread without substantial penetration of the coating into the thread;
[0027] [0027]FIG. 15 is a photograph illustrating a perspective view of an abraded prior art sewing thread coated with a conventional solvent based system and illustrates stripping of the coating caused by abrasive forces such as are encountered in sewing processes; and
[0028] [0028]FIG. 16 is a photograph illustrating a perspective view of an abraded coated sewing thread of the invention and illustrates the absence of any substantial stripping of the coating.
DETAILED DESCRIPTION OF THE INVENTION
[0029] In the following, a detailed description of the preferred embodiment of the invention is given. It will be recognized that although specific terms are used, they are used in a descriptive and not in a limiting sense in that the invention is susceptible to numerous variations and equivalents within the spirit and scope of the description of the invention.
[0030] Referring to FIGS. 1 and 2, an exemplary process and apparatus for coating sewing thread in accordance with the invention is illustrated. FIGS. 1 and 2 illustrate a system for in-line coating of multiple threadlines. The skilled artisan, however, will appreciate that the invention can include coating more or fewer threadlines than illustrated.
[0031] The threadlines, designated generally as 10 , are directed from supply packages 12 into a coating apparatus, designated generally as 20 , via entry ports 22 . The threadlines can be preconditioned or pretreated to provide moisture levels desirable for a particular resin system, for example, by minimizing exposure of the threadlines to atmospheric humidity and/or removing moisture from the threadlines prior to coating. The threadlines can be preheated, for example, using a standard UV unit, prior to entry into the coating apparatus.
[0032] Typically, a threadline comprises one or more multifilament plies which are individually twisted in a first direction and then combined by twisting in an opposite direction to produce a multi-ply thread construction. The threadline, however, can include one, two, or more than three multifilament plies or other structures used to form sewing thread as will be apparent to the skilled artisan. The multifilament plies are typically composed of a relatively high tenacity multifilament continuous filaments such as nylon, polyester or the like. By way of illustration, the individual or single multifilament plies typically have a denier (decitex) within the range of from about 50 to about 500 denier (56-556 decitex). Thus, the thread illustrated in FIG. 1 (comprising three individual multifilament plies) typically has a total denier ranging from about 150 to about 2,000 denier (167 to about 2,222 decitex).
[0033] As illustrated in FIG. 2, a resin supply source 24 supplies a radiation curable composition (which also can be preheated) to a resin distribution manifold via line 26 and into coating apparatus 20 . As used herein, and as will be appreciated by the skilled artisan, the term “radiation curable composition” refers to compositions which photopolymerize or cure upon exposure to radiation. Generally the composition includes polymerizable compounds, including monomers, oligomers, polymers, prepolymers, resinous materials, and mixtures thereof, and a photoinitiator, which when exposed to a source of radiation, initiates a reaction of the polymerizable materials. The radiation curable composition may be polymerized to form homopolymers or copolymerized with various other monomers.
[0034] In the invention, the preferred polymerizable compounds cure cationically, and the photoinitiator generates a proton on exposure to radiation, typically ultraviolet (UV) radiation. This cation causes the polymerizable compounds to crosslink. The cationic cure is advantageous because it is self generating. In contrast, most radiation curable compositions that are widely used in commerce are cured via a free radical mechanism in which the photoinitiator generates free radicals upon exposure to radiation, which in turn attack and initiate polymerization of unsaturated polymerizable compounds. For the polymerization to take place, the composition must be exposed to the radiation source; once the radiation source is removed, the reaction stops because free radicals are no longer generated. Thus unreacted material can remain in the coating unless all of the coating is exposed to radiation. In such cases, the coating tends to flake and/or tack.
[0035] In contrast, the cationic initiated reaction is self generating, i.e., the reaction continues after the radiation source is removed. Such compositions can provide an improved protective coating for sewing thread because the composition can more fully cure, that is, essentially all available polymerizable components of the composition are reacted. As result, essentially no flaking is observed when the thread is used.
[0036] Preferred cationically curable compounds include epoxy resins. As the skilled artisan will appreciate, radiation curable compounds other than epoxy resins can be used in the invention so long as the curing or polymerization thereof is self sustaining after the reaction is initiated by exposure to radiation. Epoxy compounds or resins suitable for use in the invention include those materials having at least one polymerizable epoxy group per molecule, and preferably two or more such groups per molecule. The epoxides can be monomeric or polymeric, saturated or unsaturated, and include aliphatic, cycloaliphatic, aromatic and heterocyclic epoxides, and mixtures thereof, and may be substituted with various substituents, such as halogen atoms, hydroxyl groups, ether radicals, and the like.
[0037] Preferably the epoxide is a cycloaliphatic epoxide. Exemplary cycloaliphatic epoxides include diepoxides of cycloaliphatic esters of dicarboxylic acids such as bis(3,4-epoxycyclohexylmethyl)adipate, bis(3,4-epoxycyclohexylmethyl)oxalate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, bis(3,4-epoxycyclohexylmethyl)pimelate, and the like. Other cycloaliphatic epoxides include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylates such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-1-methylcyclohexylmethyl-3,4-epoxy-1-methylcyclohexane carboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-2-methylcyclohexylmethyl-3,4-epoxy-2-methylcyclohexane carboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexane carboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexane carboxylate and the like. Commercially available cycloaliphatic epoxides useful in the invention include epoxides available from Union Carbide Corporation as the “Cyracure” series of materials, epoxides available from UCB Chemicals as the “UVACURE® series of materials, and the like.
[0038] Preferably the moisture content of the threadlines is controlled to maximize performance of a particular resin system. For example, the threadlines can be preconditioned or pretreated prior to coating to minimize moisture uptake and/or reduce moisture content. Alternatively, or in addition to preconditioning, the percent humidity of the coating environment can be controlled to maintain a percent relative humidity desirable for performance of a particular resin.
[0039] The cycloaliphatic epoxies can be used alone, as mixtures with one another, and as mixtures thereof with other types of epoxides, such as glycidyl type epoxides, aliphatic epoxides, epoxy resol novolac resins, epoxy phenol novolac resins, polynuclear phenol-glycidyl ether derived resins, aromatic and heterocyclic glycidyl amine resins, hydantoin epoxy resins, and the like and mixtures thereof. These epoxides are well known in the art and many are commercially available.
[0040] The epoxy can be present in amounts between about 99.9 and about 85 percent by weight of the composition.
[0041] Suitable photoinitiators include onium salts as known in the art for photoinitiating cure of epoxy resins. Such onium salts can have the general formula: R 2 I + MX n − , R 3 S + MX n − , R 3 Se + MX n − , R 4 P + MX n − , R 4 N + MX n − , wherein different radicals represented by R can be the same or different organic radicals containing 1 to 30 carbon atoms, including aromatic carbocyclic radicals containing 6 to 20 carbon atoms, which can be substituted with 1 to 4 monovalent radicals selected from the group consisting of C1-C8 alkoxyl, C1-C8 alkyl, nitro, chloro, bromo, cyano, carboxy, mercapto, and the like, and also including aromatic heterocyclic radicals including pyridyl, thiophenyl, pyranyl, and the like; and MX hu − is a non-basic, non-nucleophilic anion such as BF 4 − , PF 6 − , AsF 6 − , SbF 6 − , HSO 4 − , ClO 4 − and the like as known in the art. The term “hetero” as used herein refers to linear or cyclic organic radicals having incorporated therein at least one non-carbon and non-hydrogen atom, and is not meant to be limited to the specific examples contained herein. Exemplary photoinitiators include triarylsulfonium complex salts, aromatic sulfonium or iodonium salts of halogen-containing complex ions, aromatic onium salts of Group VIa elements, aromatic onium salts of Group Va elements, and the like. Currently preferred photoinitiators include triarylsulfonium hexafluoroantimonate salts, triarylsulfonium hexafluorophosphate salts, mixtures thereof and the like. The photoinitiator is present in the radiation curable composition in conventional amounts, typically ranging from about 0.1% to about 15% by weight, based on the total weight of the composition.
[0042] Suitable radiation curable compositions are disclosed, for example, in U.S. Pat. Nos. 4,874,798; 4,593,051; and 4,818,776, the entire disclosure of each of which is hereby incorporated by reference.
[0043] In addition, the radiation curable composition can include a pigment capable of imparting color to the threadline. The pigment can be an organic or inorganic pigment, or a mixture thereof, as known in the art. Useful inorganic pigments include without limitation metallic oxides (iron, titanium, zinc, cobalt, chromium, and the like), metal powder suspensions (gold, aluminum, and the like), earth colors (siennas, ochers, umbers, and the like), lead chromates, carbon black, and the like and mixtures thereof. Useful organic pigments include without limitation animal pigments (rhodopsin, melanin, and the like), vegetable or plant pigments (chlorophylls, carotenoids, such as carotene and xanthophyll, flavanoids, such as catechins, flavones, flavanols, and anthocyanins, flavanones, leucoanthocyanidins, flavonols, indigo, and the like), synthetic organic pigments (phthalocyanone, lithos, toluidine, para red, toners, lakes, and the like), and the like and mixtures thereof.
[0044] [0044]FIG. 3 illustrates a cross-sectional view of coating apparatus 20 of FIG. 1 taken along line 3 - 3 . Coating apparatus 20 includes a horizontally split coating die 28 with upper and lower members 30 and 32 , respectively, each member having a generally elongate shape with a rectangular or square cross-section. Die 34 is provided with a plurality of cavities or reservoirs 34 which are each in communication with a corresponding threadline entry port 22 and a threadline exit port 36 . Lower member 32 of die 28 is also provided with a plurality of radial bores 38 , each in fluid communication with an individual reservoir 34 and with the resin distribution manifold via one of a plurality of lines 40 to allow the radiation curable composition from source 24 to be fed into each reservoir 34 . Each reservoir 34 preferably has a generally cylindrical shape which is tapered at the entry and exit ports, although other reservoir configurations can be used.
[0045] Each threadline enters the coating apparatus via a discrete entry port 22 into a reservoir 34 and then exits the coating apparatus via an exit port 36 . As best seen in FIGS. 5 and 6, the split coating die 22 is divided into the upper and lower members 30 and 32 along a plane that extends through the entry and exit ports 22 and 36 of each die cavity 34 . This construction allows easy threading at start-up of the coating process when the upper member 30 of the split die is removed. The threadlines can be alternatively threaded through the coating apparatus 20 using an aspirator or other suitable means.
[0046] Pressurized radiation curable composition is directed from resin supply source 24 through line 26 to the resin distribution manifold and into each reservoir 34 via lines 40 . As threadlines 10 pass through the coating apparatus, and in particular through reservoirs 34 filled with pressurized radiation curable composition, the threadlines are coated with the composition.
[0047] The pressure of the radiation curable composition within reservoirs 34 can vary, depending upon factors such as the working viscosity of the composition, the desired level of pickup, and the like. Advantageously, the composition is pressurized to assist with control of the desired level of pickup.
[0048] The inventors have also found that the invention can be used with a wide range of radiation curable composition viscosities, ranging from about 100 centipoise (cP) to about 8000 cP, and higher at room temperature. Preferably, the viscosity and pressure of the radiation curable composition within reservoir 56 are selected to provide a threadline pickup of about 1 to about 20 percent, and more preferably about 5 to about 12 percent. For example, in one advantageous embodiment of the invention, a radiation curable composition having a viscosity of about 500 to about 2000 cP is supplied within reservoir 56 at a pressure less than about 5 pounds per square inch (psi). Radiation curable compositions having higher viscosities can also be used in combination with higher pressures (for example, a viscosity of about 5000 to about 7000 cP at a pressure of about 30 to about 50 psi), to achieve comparable degree of resin pickup onto the threadline.
[0049] In addition to varying and controlling composition viscosity and pressure within reservoirs 34 to control pickup of the composition by the threadline, the coating process of the invention also includes a “contact coating” step to control pickup. As used herein, the term “contact coating” refers to applying the pressurized radiation curable composition to the exterior of the threadline within the coating apparatus 20 while also contacting the coated threadline with a suitable surface to impregnate the composition into the periphery of the threadline.
[0050] In one embodiment of the invention, each exit port 36 of coating die 28 has a diameter which is slightly smaller than the cross sectional dimension of each of the threadlines 10 . In this embodiment of the invention, the coated threadline contacts the edge of port 36 as the threadline passes therethrough. In another embodiment of the invention, a deformable porous media can be inserted into reservoir 34 which surrounds and contacts the threadline as it passes through the reservoir. For example, as illustrated in FIG. 7, a felt material 42 can be formed into a shape corresponding to the interior configuration of the reservoir 34 , although other conformable, porous media can also be used. In this embodiment of the invention, this contact in effect “wipes” the coated threadline so as to control pickup. As a result of the contact coating step, the resultant threadline exhibits a thin layer of radiation curable composition that has been impregnated into the periphery of the threadline to provide a coated sewing thread which is structurally distinct from conventional sewing thread, as described in more detail below. Impregnation can be controlled, however, so that the resultant thread is not undesirably stiff due to excessive penetration of the resin into the thread structure.
[0051] This contact coating step contrasts with conventional processes for coating continuous substrates. For example, typically sewing thread is immersed in a low solids content solution of the bonding agent, passed through cooperating rotating rolls to remove excess bonding agent, and then heated to evaporate the solvent. However, this process can result in undesirable levels of resin pickup, which can result in excessively thick coating sheaths, wasted material, and the like. The pressure of the nip can be controlled to remove excess resin, but excessive pressure can cause the resin to impregnate the thread. This is typically avoided because of the resulting increased stiffness.
[0052] On the other hand, conventional die coating processes for coating wires, optical fibers and the like with a radiation curable composition typically include directing the optical fibers through a coating apparatus which includes a cavity filled with a pressurized radiation curable composition. However, in contrast to the present invention, typical wire and optical fiber coating processes do not include a contact coating step. Instead, the exit orifice of the die has a diameter greater than the diameter of the fiber or wire and acts as a cylindrical doctor blade to apply a continuous sheathlike coating of the composition to the wire or optical fiber. Great efforts are taken in these processes to prevent the coated fiber from contacting or touching any surface to prevent harming the optic fiber.
[0053] Also as illustrated in FIGS. 3 and 4, coating apparatus 20 can include a clamping element 44 for applying substantially equalized clamping pressure to each reservoir 34 . The clamping element 44 includes a pair of pivoting arms 46 , each positioned for movement between a position that is non-aligned with the coating die 28 , and a die contacting and pressure distributing position aligned with an upper outer surface of the coating die (illustrated by the arrows in FIG. 4). Each arm preferably applies clamping pressure to the upper portion of the split die via a pressure distributing bar 48 attached thereto via suitable fastening means, such as a threaded bolt 50 .
[0054] When actuated, each arm 46 rotates from the noncontacting position inwardly towards coating die 28 until pressure distributing bars 48 rest upon an upper outer surface of the coating die 28 . The pressure distributing bars advantageously provides substantially equalized pressure across each cavity 34 so as to control and equalize pickup of resin by individual threadlines passing therethrough.
[0055] Returning again to FIGS. 1 and 2, after exiting the coating apparatus 20 , the coated threadlines 10 are directed into a radiation curing chamber 50 via a plurality of conventional guides, not shown. As illustrated in FIG. 8, radiation curing chamber 50 includes a housing 52 comprising a base 54 and a cover 56 mounted for movement about a pivot 58 . Disposed within the housing 52 is an elongate radiation source 60 oriented perpendicular to the path of the threadlines 10 , which emits radiation of a suitable wavelength and intensity to initiate cure of the radiation curable composition on the threadlines. The radiation source 60 is mounted in a reflecting chamber within housing 52 to focus radiation emitted by the radiation source about each threadline. In a preferred embodiment as illustrated in FIGS. 8 and 10, the reflecting chamber includes an upper focusing reflector 62 oriented in the direction of the threadlines and a single elongate bottom diffusing reflector 64 oriented in the direction of the radiation source 60 . Reflectors 62 and 64 can be formed of any of the types of material known in the art suitable for reflecting radiation.
[0056] The upper focusing reflector 62 includes a plurality of individual semicircular reflector cavities, each extending from a threadline entry port into the housing 52 to a threadline exit port out of the housing 52 , and each having a longitudinal axis parallel to the path of the threadlines 10 through the radiation chamber. The bottom diffusing reflector 64 (FIG. 10) is preferably a single channel shaped cavity having a longitudinal axis perpendicular to the path of the threadline through the radiation chamber. The radiation source 60 and the reflecting chamber, including top focusing reflector 62 and bottom diffusing reflector 64 , through which the threadlines travel are positioned so that substantially all of the periphery of the moving threadline is impinged by radiation emitted by the radiation source 60 . Although not required, the curing chamber 50 can be continuously flooded or purged with an inert fluid, such as nitrogen, argon, helium, and the like to prevent or minimize adverse effects on the curing due to the presence of oxygen in the curing chamber.
[0057] If desired, housing 52 can be adapted to receive a suitable monitoring device to monitor energy levels emitted by radiation source 60 , such as a probe 66 in FIG. 8. In addition, the curing chamber can include an exhaust duct 68 and cooling vent 70 to exhaust heat generated by the process from the chamber and to introduce cooling fluid into the chamber to thereby control temperature within the chamber.
[0058] Although the curing chamber as illustrated includes one radiation source, more than one radiation source can be included within the chamber. Alternatively, as illustrated in FIGS. 1 and 2, more than one curing chamber, designated as chambers 72 and 74 , can be provided. In addition, although an elongate radiation source is illustrated perpendicular to the path of the threadlines, in an alterative embodiment of the invention, one or more elongate radiation sources can be used which are parallel to the threadlines.
[0059] The active energy beams used in accordance with the present invention may be ultraviolet light or may contain in their spectra both visible and ultraviolet light. The polymerization may be activated by irradiating the composition with ultraviolet light using any of the techniques known in the art for providing ultraviolet radiation, i.e., in the range of 240 nm and 420 nm ultraviolet radiation, or by irradiating the composition with radiation outside of the ultraviolet spectrum. The radiation may be natural or artificial, monochromatic or polychromatic, incoherent or coherent and should be sufficiently intense to activate polymerization. Conventional radiation sources include fluorescent lamps, mercury, metal additive and arc lamps. Variable irradiant platform lamps available from Fusion Systems, which emit a narrow wavelength band of 308 nm, are also advantageous in the present invention to more closely match the chemistry of the radiation curable composition. Coherent light sources are the pulsed nitrogen, xenon, argon ion- and ionized neon lasers whose emissions fall within or overlap the ultraviolet or visible absorption bands of the compounds of the invention.
[0060] The radiation time can depend on the intensity of the radiation source, the type and amount of photosensitizer and the permeability of the composition and the threadline to radiation. The threadline can be exposed to radiation for a period ranging from about 0.05 second to about 5 minutes. Irradiation can be carried out in an inert gas atmosphere but this is not required.
[0061] Returning to FIGS. 1 and 2, threadlines 10 exit the curing chamber(s), are directed between the nip of a capstan device defined by cooperating idle rolls 76 and 78 , and taken up via a plurality of individual winders 80 for storage. Alternatively, the threadlines can be directed to additional downstream processing.
[0062] Also as illustrated in FIGS. 1 and 2, a computer control system 82 can be used to monitor threadline tension and detect breakage of a threadline. If a break is detected, the control system can actuate a value to close off the specific resin supply line 40 to the reservoir 34 associated with the broken threadline to stop resin feed into the reservoir to minimize resin loss. The control system can also deactivate the power supply to the threadline supply and/or wind up rolls associated with the broken threadline. Additionally, the control system can also monitor the coating resin supply.
[0063] The resultant coated sewing thread of the invention differs structurally from conventional coated sewing thread. As noted above, the radiation curable coating is applied so that the resin penetrates into the periphery of the sewing thread, preferably to a depth of one to about three single filament layers (or diameters). As a result, the peripheral filaments of the sewing thread are bonded to each other and in some cases to the next interior level of filaments. However, even though resin penetrates the thread, the sewing thread can be flexible and is suitable for conventional applications, and in particular for highly demanding industrial applications, such as assembly of densely woven fabrics used to produce shoes, soft luggage, and the like, and other dense materials such as leather.
[0064] [0064]FIGS. 11 through 16 illustrate the structural differences between sewing thread coated with a conventional solvent system and sewing thread of the invention which is coated with a radiation curable, self sustaining polymerizable composition. FIGS. 11 - 13 are photographs illustrating perspective views of sewing thread coated in accordance with the present invention. As demonstrated by FIGS. 11 - 13 , the resin penetrates into the periphery of the sewing thread for a distance of from one and up to about three filament diameters (and more in some cases), thus bonding the outer filaments to one another and to some of the immediately underlying interior filaments as well. Thus, in the coated sewing thread of the invention, the sheath or coating is integrated into the exterior filaments of the thread. Further, as illustrated by FIGS. 11 - 13 , the thickness of the coating is not uniform, but rather can vary, for example, depending upon the degree of penetration of resin in a given location along the periphery of the thread. Further, for thread comprising more than one multifilament ply, the coating can fill in the gaps between plies, in contrast to thread coated with a solvent system in which the cast resin bridges the gap between plies. Still further, the thickness of the coating can vary depending upon the percent pickup, the denier of the thread, the number of filaments per cross section of the ply, and the like.
[0065] In contrast, as demonstrated by FIG. 14, which is a greatly enlarged perspective view of a solvent coated sewing thread (again using the Elvamide system), a continuous sheath of resin is formed around the sewing thread and does not extend substantially into the thread. In essence, the solvent based system is cast as a separate film surrounding the periphery of the thread, which remains as the continuous sheath after the solvent is evaporated.
[0066] [0066]FIG. 15 is a perspective view of an abraded sewing thread which was coated with a nylon solvent based system, commercially available as the Elvamide series from DuPont. When the sewing thread was subjected to an abrasion test that simulates abrasion applied to the thread by a sewing needle, the coating is removed as strips. These strips are sometimes visible as a white powder or flakes on sewn products. In contrast, as illustrated in FIG. 16, when the coated sewing thread of the invention is subjected to the same abrasion conditions, minimal displacement of the coating is observed.
[0067] The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. | Processes for coating sewing thread using a radiation curable composition and the resultant coated sewing thread. Sewing thread is coated with a radiation curable composition, which exhibits a self sustaining cure after exposure to radiation. The composition is applied using contact coating techniques to coat and impregnate the thread with resin. The coated thread is then exposed to radiation to cure the coating. Because the cure is self sustaining, the composition more fully and completely reacts to form a coating with increased durability and reduced susceptibility to stripping or flaking during use in demanding industrial applications. | 3 |
FIELD
This invention relates to production of textile yarns.
PRIOR ART
It is known that core/wrap or wrapped core yarns may be produced by wrapping a fibrous sheath around a continuous filament core. Alternatively, a continuous filament may be wrapped around a staple fiber core. Still further, both the core and wrapping or sheathing may consist of staple fibrous materials, or both may be continuous filament materials. To date, in the production of ring-spun core/wrap yarn with staple fibrous materials, the wrapping step has been carried out prior to ring spinning, i.e., during the formation of roving from sliver, thereby producing a core-wrap roving, which subsequently must be spun into yarn in a ring spinning step; or during the drawing process, thereby producing a concentrically cored sliver, which subsequently must be roved into roving and spun into yarn in a ring spinning step. To date, no practical system has been developed to directly produce core/wrap yarn in a ring-spinning frame from a plurality of unwrapped roving strands.
The following definitions apply to several terms that appear in the specification and claims:
Carding--the use of a carding machine to align, clean, and straighten fibers, and to remove very short fibers as well as fine trash, to produce sliver.
Drawing--the making parallel and straightening of sliver fibers to improve the uniformity of linear density, usually accomplished in 1, 2, or 3 passages through drawing equipment known as a draw frame or drafting frame. In each passage through a draw frame, several sliver strands are combined into a single sliver strand.
Drafting--the process whereby a fiber bundle such as a sliver or roving is extended in length in order to reduce the linear density of the bundle and to increase the parallelization of the fibers. Various forms of drafting are employed in carding, drawing, roving, and ring-spinning.
Sliver--the product produced by carding or drawing, i.e., a very coarse strand of fibers having essentially no twist.
Roving process--conversion of sliver by drafting into a thinner strand called a roving in which a small amount of twist (normally 2 turns per inch) is imparted to the strand. This step is performed only in conjunction with subsequent ring spinning. No other type of spinning presently requires roving prior to spinning.
Ring-spinning process--As used herein, an operation for converting roving into yarn by drafting a roving and imparting twist through use of a ring and a moving traveler on a ring-spinned frame. A small percentage of ring-spinning machines do not require prior formation of roving, but instead convert sliver directly into yarn except that the sliver is passed through additional drafting apparatus on the ring frame immediately prior to passage through the ordinary draft rolls/aprons associated with ring spinning.
SUMMARY
A new system is provided for directly producing core/wrap yarn from a plurality of unwrapped rovings. Broadly, the invention comprises feeding a core strand and wrap strand on each side of the core strand from the nip of a pair of draft rollers directly to a stationary strand support immediately downstream from the nip. The wrap strands, which are spaced from the core strand at the nip, converge with the core strand in an open channel on the support means, and wrap around the core strand, so as to form core/wrap yarn.
The support means provides an outwardly, downwardly curved support surface for the core and wrap strands. The curved surface includes an open channel which extends along the outwardly, downwardly curved support surface. The convergence and wrapping of the strands takes place in the channel.
The wrapped yarn then is passed to an ordinary ring traveler and wind-up spindle of a ring-spinning assembly. In this manner, unwrapped roving is a converted to core/wrap yarn in a continuous process.
It is an object of the present invention to produce a new core/wrap yarn having the following advantages and distinctions over previous yarn products:
It is covered at least 90% compared to much lesser percentage of previous core/wrap products.
The core fibers are oriented along the length of the yarn and are positioned in the middle of the cross-section.
Due to unique interlacing of the cover fibers (effected by two strands of drafted rovings, one on each side of the core material), the yarn sheath does not strip from the core at all. Furthermore, the strip resistance is equally good in both directions along the yarn.
The staple-core/cotton-wrap yarn produced with a high tenacity staple fiber is significantly stronger than an equivalent 100% cotton yarn or an equivalent, regular intimate-blend yarn.
The device is capable of producing relatively fine yarns (e.g., yarns of up to 40/1 cotton count or finer).
Both the core as well as cover fibers contribute to the mechanical properties of the yarn produced by the present system; and mechanical properties, such as tear strength, tensile strength and abrasion resistance, of the fabrics produced from such yarns have exhibited significant improvements.
The staple-core-spun yarns of the present invention are economical compared to existing filament-core yarns, mainly because of the lower cost of the staple fibers, compared to filament yarns.
Inferior quality cotton, wool, manmade fibers, or any other fiber can be used in the core, and the premium fiber can be utilized in the cover to produce a premium-looking product.
Many types of novelty yarns and fabrics, such as crepe-like, denim-like, and differential dye effects, can be producing by the spinning technique of the present invention.
It is much easier to piece-up the ends during spinning, when compared to earlier reported spinning techniques.
The staple-core yarns are highly useful for producing textile products where high strength and cotton surface are both desirable and/or critical, such as strong, easy-to-care-for and comfortable apparel of predmoninantly cotton; certain military fabrics; such as tentage, chambray shirting, work uniforms, strong sewing threads with heat-insulation cotton cover, and strong pill-resistant fabrics.
Other objects and advantages of the present invention will be obvious from the following detailed description, in conjunction with the drawings in which:
FIG. 1 is a perspective view of the overall system of the present invention.
FIG. 2 is a partial perspective view of bar 20 of FIG. 1.
FIG. 2a is an alternative embodiment of FIG. 2.
FIG. 3 is a side view of part of the apparatus of FIG. 1.
FIG. 3a is a side view of an alternative embodiment.
FIG. 4 generally shows the use of bar 20 in conjunction with a plurality of side-by-side spinning systems mounted on the same frame.
DETAILED DESCRIPTION
Components of ordinary ring spinning equipment may be employed in the practice of the present invention. These are illustrated in FIG. 1 as rear draft rollers 1, drafting aprons 2, front draft rollers 3, pigtail guide 4, ring 5 and yarn bobbin 6. Hereinafter, this combination of elements is referred to as a single spinning system.
In addition, there are three bobbins upstream of rear draft rollers 1. Two of these bobbins feed wrap roving 9 and 10 such as cotton roving to rear rollers 1, while the other bobbin feeds core roving 12 such as polyester roving thereto.
Starting materials for the practice of the present invention, such as cotton and polyester rovings, may be prepared in a conventional manner.
A conventional roving condenser 14 is disposed between the bobbins and rear rollers 1 in order to maintain a space between rovings. In addition, another condenser 15 is positioned between rollers 1 and aprons 2 so as to provide unconventional spacing between strands that emerge from the nip of front rollers 3. That is, this latter condenser is dimensioned to provide unequal spacing from the core strand to each wrap strand at the point of emergence of the strands from the nip of front rollers 3. In other words, the space between wrap strand 9 and core 12 is not the same as the space between wrap strand 10 and core 12 at the point of emergence of these strands from the nip of the front rollers 3. More specifically, the spacing between strands 9 and 12 is slightly less than the spacing between strands 10 and 12 in the case of a "Z" twist at yarn formation (FIG. 2), and vice-versa in the case of "S" twist (FIG. 2a). Generally, the lesser spacing is about 70-80% of the greater spacing between centerlines of respective strands.
Referring to the lesser spacing between wrap and core, this will depend upon the fiber length being processed, and consequently on the size of the spinning equipment (i.e., short-, mid-, or long-staple spinning system). For a conventional cotton (short-staple) spinning system, the lesser space between wrap and core strands may be about 3/32" to 5/32". For long staple fibers such as wool, this dimension may vary from about 1/4" to 5/8".
Referring again to FIG. 1, disposed between pigtail guide 4 and front rollers 3 is a cylindrically-shape, hollow or solid bar 20. The bar provides an outwardly, downwardly directed support surface for the core and wrap strands. The bar acts as a support for the strands and as the point at which wrapped yarn formation occurs.
As can be seen in FIGS. 2 or 2a, a groove 21 is present in bar 20 which constitutes the necessary open channel in the support surface through which the core strand passes, and in which the wrap strands envelop the core strand. Groove 21, which lies in a plane which is perpendicular to the plane of the front roller nip, is positioned such that core strand 12 passes directly from the nip into the groove, while wrap strands 9 and 10 first pass in contact with the surface of bar 20 adjacent groove 21 before entering the groove.
Bar 20 and the wall of groove 21 most preferably are polished at least where these elements directly contact the wrap and core strands.
The diameter of bar 20 depends upon fiber length, especially of the wrap fiber length. For a typical 1.5" long polyester-staple-core and 1" long cotton-wrap fibers, the diameter of the bar may be about 3/8" to 3/4". For a 3" long staple fiber, the bar may be as much as 2" in diameter.
The fibrous strands emerging from the roller nip are weak due to absence of twist. Only the inter-fiber cohesion and the support of bar 20 keep the materials intact and continuously flowing without breakage or interruption.
The distance between bar 20 and the front roller nip should be such that there is essentially no drafting of the core strand between these two points. Thus, the distance between the yarn wrapping zone on bar 20 and the front roller nip, measured along the core strand, is less than the length of most of the fibers in the core strand. By avoiding drafting, the full yarn tension is maintained in the core strand upstream of bar 20. The loss of this tension otherwise would allow excessive "twist" upstream of bar 20 and would result in barber-poling and less than subsequent full coverage of the core strand by the wrap strands.
In addition, the distance of bar 20 from the front roller nip should be such that there is no drafting of the longest fibers (i.e., for cotton, the so-called "2.5% span length" fibers) in the wrap strands, but there is drafting of some of the shorter fibers therein. In other words, the distance along each wrap strand from the point of emergence of each wrap strand at the front roller nip to the yarn formation point on bar 20 is greater than the shortest fiber length therein but about 50-80% of the "staple" length. In the case of cotton-wrap fibers, the distance along the wrap strands measured from front rollers nip to yarn formation typically is about 1/2" to 7/8".
Thus, in the practice of the present invention, the fibers, after emerging from the nip of the front rollers, are loose with no twist to hold them together except for the slight twist imparted to the core-strand-fibers during passage from nip to bar. The bar acts as a guide for transportation of fibers from the nip to the yarn formation point on the bar.
With further regard to positioning the bar, its longitudinal axis generally may be approximately equidistant from and parallel to the axes of the two front rollers, as shown in FIG. 3. The exact position should be set to provide the appropriate fiber path, as set forth above, from the nip of the front rolls to the point of contact with the bar, while still allowing clearance between the bar and each of the front rolls. The clearance between the bar and the nip front roll should be sufficiently large that even the thickest segments of drafted strands cannot be gripped between these surfaces, which would otherwise have the undersirable effect that the lateral movements of the wrapper fibers would be restricted and the flow of fibers would be interrupted. The clearance between the bar and the bottom front roll should be sufficiently large to that the bar does not interfere with the scavenging of fibers by the spinning system's vacuum system in case of yarn breakage. The use of a bar having a half-circle rather than full circle cross-sectional shape permits the bar to be positioned closer to the nip and bottom roll, as shown in FIG. 3a.
Taking the above factors into account, a typical spacing between the front roller nip and the closest surface of the bar is about 1/4" to 7/16" in the case of cotton/polyester wrap/core, and about 1" to 2" with regard to wool/polyester wrap/core.
Referring again to FIGS. 2 or 2a, groove 21 in bar 20 may be "v" shaped, rectangular, oval, circular, or any concave shape. Its width preferably should be slightly wider than the core strand diameter, i.e., about 11/2 to 2 times the core strand diameter. The depth of the groove is about the same as the width, preferably about 75-150% of the groove width, depending upon groove shape. A flat (rectangular) groove may have a depth less than the width, while a "v" shaped groove may have a maximum depth greater than its maximum width.
Immediately after emergence from the front roller nip, the core and wrap strands tend to be flattened. However, the core strand tends to become cylindrical in cross-section as a result of being pulled into the groove 21 and as a result of some twist and tension being imparted thereto from downstream forces. These overall forces tend to condense and aggregate the core strand into a circular or oval cross-sectional shape.
As the strands emerge from the nip they are merged into a so-called sandwich in groove 21 with the core strand in the middle. One wrap roving lies below the core strand, and the other wrap roving lies about the core strand in the wrapping zone, as illustrated in the alternative embodiments of FIGS. 2 and 2a. The two wrap strands thereafter spirally wind around the core strand.
As shown in FIGS. 1-3, an "L" shaped yarn control guide 25, immediately downstream from and closely adjacent to bar 20, is screwed or otherwise attached to the bar. Guide 25 functions to prevent excessive yarn twist from flowing upstream past the guide.
In addition, guide 25 stabilizes the zone of contact between the fibers and bar 20. More specifically, as can be seen in FIGS. 1a or 1b, the initial points of contact between the core strand and each of the two wrap strands do not coincide with one another. The wrap strand which initially contacts the core on the underside of the core ordinarily is the first contact point between strands, which is designated as point C in FIG. 3, while the other wrap strand "overwraps" at a second downstream contact point D. The arc CD is the wrap zone. Prior to initial contact between any of the fibers, all three strands first should come into contact with the surface of bar 20 along a common line stream from point C, so that wrapping takes place on the bar 20, and not between the bar 20 and the front roller nip. This common line of contact, viewed on end as "A" in FIG. 3, is determined by the plane tangent to the upper roll of the front rollers 3 and the bar 20. Point B in FIG. 3 is the point of final contact of the wrapped yarn with the bar. This point is determined by the tangent from bar 20 to the surface of guide 25.
Arc AB in FIG. 3 defines the zone of direct contact between the fibrous strands and the bar. In operation, the wrapping zone CD should be stable and finite, and within AB, despite normal fluctuations in the overall nature of the contact between the fibrous strands and bar 20 during the dynamics of the spinning operation. Otherwise, there will be less than maximum coverage of the core strand by the wrap strands. In this context, about 30°-90° of arc measured along the core strand should remain in contact with bar 20 during operation.
Some factors which are taken into consideration in the postioning of guide 25 are as follows: As the pigtail guide 4 moves up and down with the ring rail 5 during winding of the product yarn, a positive deflection angle (FIG. 3 reference numeral 40) of the yarn from bar 20 around guide 25 to pigtail guide 4 (not shown in FIG. 3) should be maintained at all times. This deflection, however, should be as little as possible so as to avoid "trapping" too much twist, i.e., to avoid the situation where not enough twist flows upstream to maintain the integrity of the yarn or to perform the wrapping operation within the arc AB. This can be achieved by setting guide 25 so that it slightly deflects the path of the yarn from bar 20 to pigtail guide 4 when the pigtail and ring rail are at their lowest point in the package-building motion. For a typical cotton spinning frame, a minimum deflecton angle of about 10° to 15° is sufficient. The maximum deflection angle will occur when the pigtail guide and ring rail are at the maximum upward position, and typically will be about 9° greater than the initial (minimum) setting.
A simple way to provide for positioning of guide 25 is to fixedly secure it to bar 20 as by means of screws, and to mount the ends of bar 20 on the spinning frame in such a manner as to provide for rotational adjustment of the bar about its own axis (i.e., the bar is screwed at its axis to a bracket which in turn is fixed to the frame of the spinning system). In this arrangement, whenever the position of the bar is changed by loosening its axial screws and rotating the bar, guide 25 likewise is repositioned in a clockwise or counterclockwise direction around the bar.
During the spinning operation, if too much twist begins to flow back upstream so that, for instance, wrap zone CD migrates upstream of line A resulting in a barber-pole yarn, then the guide 25 can be repositioned (clockwise around bar 20 in FIG. 3) to increase the minimum deflection angle and thereby increase frictional drag, trap more twist, and re-adjust the position of the wrap zone back within arc AB on bar 20. This adjustment can be performed conveniently during the spinning operation, if the guide 25 is attached to the bar 20 as described above, by rotating the bar slightly while observing the wrap zone CD, so as to cause CD to center well within arc AB.
It also is desirable to minimize the change in deflection as the pigtail guide moves. Thus, guide 25 should be as close to bar 20 as possible to minimize this variation. On the other hand, there should be sufficient clearance to permit easy piecing up. Generally, a distance of about 1/2" to 3/4", between guide 25 and bar 20 will be sufficient for both these purposes. In an alternative embodiment, guide 25 may be spring-loaded against the surface of bar 20 so as to lightly grip the yarn passing between bar and guide.
In the preferred practice of the present invention, one continuous bar may accomodate several side-by-side spinning systems, as illustrated in FIG. 4, so that there is a single open channel or groove 21 adjacent each front roller pair in each of the spinning systems. The ends of the bar may be screwed into brackets 30 at the axis of the bar, which brackets in turn are secured to the overall frame 35 of the spinning systems.
With regard to the operational speeds of the system of the present invention, spindle speed may be the same as that employed to spin yarn of a given linear density and twist multiple, in the ordinary manner, from a roving having the same overall blend composition and combined linear density as the three rovings (two wrapper plus core). In this case, the same twist gear and draft gear ratio would be used, and the same linear density yarn produced. The three rovings creeled per position in the present invention would each have to be prepared with linear densities, on the average, 1/3 of the linear density of the conventional roving.
Alternatively, a separate approach would be to use three rovings, each having the same linear density as the comparable conventional single roving. In this case, however, the draft gear would be selected to increase the draft by a factor of three because three times as much roving (three rovings versus one roving) is pieced into the drafting zone. The same twist gear and spindle speed would produce the same yarn linear density and twist multiple as in the conventional single-roving case.
A third approach combines a change in linear density of the rovings with a change draft gearing. One combination would be to reduce the roving linear densities by a factor of two, and increase the draft by a factor of 1.5. For instance, if a 1-hank roving is normally used with a draft of 28 to produce Ne 28 yarn in the conventional way, then three 2-hank rovings (one core and two wrapper rovings of different composition) may be used with a draft of 42 to produce Ne 28 core/wrap yarn by the present invention. Once again, the spindle speed and twist gear ratio of the machine would be the same, as would the resultant twist multiple of the yarn produced.
It will be obvious to those skilled in the art that many other practical combinations as to operational parameters exist. Variations in twist multiple, production rate, and yarn count may be accomplished by purely conventional manipulation of the textile relationships between the variables of roving linear density, spindle speed, twist and draft gearing, traveler weight, and so forth. In addition, basic ring spinning rules are to be considered. For instance, in cotton ring spinning, it is generally desirable to keep the draft below 50, and the roving count below three hank.
The following are general spinning parameters for a 28-tex, 67% cotton/33% polyester-staple-corn yarn produced by the system of the present invention:
______________________________________polyester roving (1) = 2-hank (1.5"; 1.2 denier; and 6 g/deniercotton rovings (2) = 2-hank (1 1/16" staple; Acala) each;combined hank of roving = 0.67total draft = 42spindle speed (rpm) = 9,100twist multiple = 4.00traveller = #6 (1.6 grains)relative humidity = 51temperature (C.) = 20______________________________________
The present invention may be employed to wrap fibrous materials around continuous filament core material such as continous filament polyester, as well as around staple core material. When such continuous filament material is employed as the core strand, instead of being introduced into the drafting system through the back rolls, the filament core is fed into the drafting system immediately behind the front rollers and in alignment with groove 21 in bar 20. The operational speeds of the drafting zone and spindle speed are the same as for a similar system employing staple core material of the same linear density. The resulting product made from continuous polyester filament core strand and cotton wrap quite surprisingly has the same excellent strip resistance as a core/wrap yarn having a staple core strand. | A core wrap system is provided in which a core strand and wrap strands spaced from said core strand on each side of said core strand are passed from the nip of a pair of rollers to a stationary support surface that is outwardly, downwardly curved, and which includes an open channel therein which is outwardly, downwardly curved along the surface; wherein the core strand is passed through the channel from the nip; wherein the wrap rovings are passed from the nip to converge upon and wrap around the core strand in the channel to form wrapped yarn in the channel; and wherein wrapped yarn then is passed through a ring traveler to a wind-up spindle. | 3 |
[0001] The present Patent Invention has the objective of obtainment, by means of extrusion/injection, a polyamide compound, such as polyamide-6, reinforced with natural fibers.
[0002] Therefore, one of the objectives of the present patent is to replace the fibers of inorganic materials, such as, for example, fiberglass, with fibers from organic materials, such as, for example, Curauá fiber in polyamide compounds.
FUNDAMENTS OF THE INVENTION
[0003] The use of synthetic fibers as a reinforcement in polymers has been made by the industry in order to obtain materials with better mechanical performance. However, they have high abrasive power, resulting in wear in equipment used for the processing, in addition to the fact that they are not degradable by exposure to the environment.
[0004] There is a growing interest in the use of natural fibers as reinforcement in compounds with thermoplastic matrixes [M. Palabiyik, S. Bahadur. Wear, 253 (2002) 369-376.], [J. J. Rajesh, J. Bijwe, U. S. Tewari. Journal of Materials Science 36 (2001) 351-356.], [S.-H. Wu, F.-Y. Wang, C.-C. M. Ma, W.-C. Chang, C.-T, Kuo, H.-C. Kuan, W.-J. Chen. Materials Letters 49 (2001) 327-333.], [A. G. Pedroso, L. H. I. Mei, J. A. M. Agnelli, D. S. Rosa. Polymer Testing, 18 (1999) 211-215.], [A. G. Pedroso, L. H. I. Mei, J. A. M. Agnelli, D. S. Rosa. Polymer Testing, 21 (2002) 229-232.], [S. V. Joshi, L. T. Drzal, A. K. Mohanty, S. Arora.], [M. A. Silva Spinacé, K. K. G. Fermoselli, M.-A. De Paoli, PPS 2004 Americas Regional Meeting, 2004 Proceedings, Florianópolis, S. C., Brazil, 48-49.] and [A. L., Leão R. Rowell, N. Tavares, Sci. Technol. Polym. Adv. Mater, (1998) 756.].
[0005] This interest is due to its low cost and some advantages such as: they are atoxic, obtained from renewable sources, are recyclable, biodegradable, have low density, good mechanical properties and low attrition on processing equipment when compared to inorganic fibers. In addition, the production of inorganic fibers, such as fiberglass for instance, requires large amounts of power, increasing its impact on the environment. However, the hydrophilic nature of natural fibers influences in the properties of adhesion due to the weak interfacial interactions between the fiber and the polymeric matrix, affecting the mechanical properties of the compound. A way of improving the adhesion of the fiber with the polymeric matrix is by means of modification of the fiber surface by physical and or chemical methods, or by using coupling agents. Currently, different natural fibers have been studied for the obtainment of these compounds. Among them stands out the fiber extracted from plants belonging to the family of the bromeliaceous, which are found in the Amazon region. These species do not require soils of high fertility and can be planted in sandy texture soils, but with a high level of organic matter.
[0006] An example of this type of plant is the Curauá ( Ananás erectofolius of the species L. B. Smith), which was considered as the ideal substitute of fiberglass for some applications, as it presents a lesser density, cost and abrasiveness on the processing equipment, when compared with fiberglass.
BRIEF DESCRIPTION OF THE INVENTION
[0007] Based on the state of the art, and aimed at optimizing it, the present patent of Invention was developed.
[0008] The present invention establishes the fact of using a natural fiber to obtain a compound with mechanical properties similar to the one obtained from inorganic loads by means of a continuous process such as extrusion and molding by injection process.
[0009] The process treated herein allows the obtainment, by means of injection, of finished products with precise and complex dimensional features.
[0010] The natural fiber of preference is the natural fiber of Curauá, which presents properties similar to that of fiberglass.
[0011] The fact of the compound with the natural fiber of Curauá presenting suitable mechanical properties combined with a lesser density than the compound with inorganic load is interesting to the automotive industry as manufactured vehicles with lighter parts consume less fuel.
[0012] The compound in question can also be employed in the civil construction industry.
BRIEF DESCRIPTION OF THE FIGURES
[0013] The preset patent of invention shall be described in detail based on the figures listed below, namely:
[0014] FIGS. 1A and 1B illustrate an example of finished product, such product being a part of the automobile industry, molded by injection using the compound of polyamides with natural fibers treated herein. The aspect and finishing of the part and its performance demonstrate that it is possible to manufacture a finished product by injection molding using natural fiber as reinforcement.
DETAILED DESCRIPTION OF THE INVENTION
[0015] As described above, the present patent invention presents two objectives, namely the process of production of the polyamide compounds with natural fibers and the genuine polyamide compounds with natural fibers.
[0016] The production process of the compounds of polyamides with natural fibers
[0017] For the confection of the polyamide compounds, preferably polyamide-6, with natural fibers, preferably the fiber of Curauá, it is
(A) employed: Natural fibers in bulk form, i.e. without washing, drying and superficial treatment; and (B) Dry natural fibers for 1.5 hours at 100° C. in a conventional kiln without superficial treatment.
[0020] The process of confection of polyamide compounds with natural fibers involves the following stages:
1) Preparation of natural fibers. This stage establishes the following sub-stages: 1.1) The natural fibers, in the forms of A or B, are ground in a cutting (knives) mill until obtainment of mean length between 0.1 to 15 mm; 1.2) The natural fibers, already ground, are superficially treated with cold plasma of O 2 or N 2 , in a quartz reactor; 1.3) The fibers are treated between an interval of 30 minutes up to 2 hours in a solution of 10% in mass of NaOH (solution with pH approximately equal to 5.0), washed once with water from main water supply, and once with distilled water (w/pH value about equal to 6.0); and 1.4) Subsequently, the fibers are dried in a kiln at 100° C. for 2 hours. 2. Confection of polyamide compounds with natural fibers. This stage establishes the following sub-stages:
[0027] 2.1) Separate the quantity of natural fibers to be used;
[0028] 2.2 Homogenize the natural fibers prepared beforehand with the polymeric matrixes; and extrude the compound obtained in sub-stage 2.2.
[0029] It is important to mention that the quantity of fibers used is from 10 to 50% in ground fiber mass in relation to the mass of the polymeric matrixes used.
[0030] The treatment method of natural fiber that produces the compound with better performance is the treatment with oxygen plasma.
[0031] The polymeric matrixes used are: polyamide-6 without any modification and or polyamide-6 containing about 1 to 10% in poly(ethylene-co-propylene-co-diene) elastomer mass functionalized with anhydrous maleic (EPDM-g-AM).
[0032] The extrusion of the compound obtained in the sub-stage 2.2 should occur in extrusion equipment of single-worm thread type (L/D=30, D=32 mm), double-worm thread (L/D=13, D=29 mm, co-rotatory, interpenetrating, worm thread with segmented shape), using rotation between 50 to 300 rpm, and temperature profile between 200 and 250° C.
[0033] After the extrusion the compound are picked off and molded by injection using temperature profile between 200 and 260° C.
[0034] The polyamide compounds with natural fibers.
[0035] The compounds obtained from the process detailed above, for the purpose of testing, injected, and from such injection obtained the trial bodies.
[0036] The obtained trial bodies were used in traction, flexion, shock, thermal distortion temperature (HDT) and density essays.
[0037] The trial bodies were characterized using ASTM standards by means of traction trials (ASTM D 638-02), flexion (ASTM D 790-02), impact (ASTM D 256-02), HDT (ASTM D 648-98c) and density (ASTM D 792-00).
[0038] The results of the traction mechanical trials for the compounds revealed that the addition of natural fibers, treated or not, acts as reinforcement to polyamide-6, as the addition (20 wt %) promotes an increase of up to 300% in the module under traction and 80% in tension in maximum force.
[0039] The values of the mechanical properties and HDT described below refer to the 3 compounds with 80 wt % of polyamide-6 and 20 wt % of Curauá fiber, talc or fiberglass, respectively. The tension values at maximum force (σmax.) and the Young module under traction (E), obtained were 80 (±1), 73 (±1), 101 (±1) MPa; and 5.1 (±0.4), 6.7 (±0.6) and 6.5 (±0.5) GPa, respectively. The values of resistance to shock, such as Izod with indentation for three compounds described above were: 9 (±1), 9 (±2) and 7 (±1) J m −1 , respectively, and for shock resistance measures without indentation were of 35 (±2), 58 (±3) and 32 (±4) J m −1 , respectively. The values measured for tension at maximum force were: 116 (±2), 114 (±2), 160 (±5) MPa, respectively. The values measured for the Young model under flexion were: 3.7 (±0.1), 4.4 (±0.1), and 5.0 (±0.1) GPa, respectively. The HDT values using 1.82 MPa tension for these compounds were: 186 (±10), 110 (±4), and 194 (±1)° C., respectively; and using 0.45 MPa tension, were: 217 (±1), 206 (±4), and 214 (±1)° C., respectively. The densities obtained for these three compounds were: 1.18 (±0.01), 1.27 (±0.01) and 1.27 (±0.01) g cm −3 , respectively.
[0040] The treatment method of the Curauá fiber, which produces the compound with the best performance is the treatment with oxygen plasma. However, the compound prepared with the Curauá fiber without treatment and polyamide-6 without pre-drying presents performance comparable to that of polyamide-6 loaded with talc. For the compounds prepared with treated Curauá fiber, the performance results are above the one of the respective compounds using talc as load and the specific mechanical properties are comparable to the one of compounds containing fiber glass. Both the values of resistance to shock and to HDT are similar to the compounds containing fiberglass.
[0041] The sweep optical and electronic micrographies showed a good distribution, dispersion and adhesion of the fiber matrix.
[0042] The analysis of the intrinsic viscosity of the polyamide-6, of polyamide-6 with stabilizing additives, and without fibers processed and injected, and of the injected trial bodies of compounds with 20 wt % of Curauá fiber, were: η=96.59 (±0.23), η=98.02 (±0.66) and η=97.47 (± 3 . 03 ) mL g-1, respectively. Therefore, it was verified that there is no matrix degradation of the polyamide-6 during the processing with or without Curauá fiber. To evaluate the finishing and appearance, a part was injected using a mold provided by a parts company, which is used for producing polyamide parts reinforced with fiberglass, as shown in FIGS. 1A and 1B .
[0043] FIGS. 1A and 1B show the finished product molded by injection, using the raw material described in this technical report. The aspect and finishing of the parts reinforced with the Curauá fiber are superior to those of parts produced with polyamide-6, reinforced with fiberglass. The performance of the part in standard trials of the automobile industry reveals that it is possible to manufacture a finished product by injection molding using natural fibers as reinforcement. This fiber is a raw material of renewable and biodegradable source for application in the automobile, civil construction industry, etc. The description above of the present invention was presented with the purpose of illustrating and describing. In addition, the description is not intended to limit the invention to the manner by which its reveled herein. Consequently, variations and modifications compatible with the above teachings and the ability or knowledge of the relevant technique, are within the scope of the present invention.
[0044] The modalities described above are aimed at providing a better explanation of the known modes for the practice of the invention and allow the technicians of the area to use the invention in such, or other modalities, and with the modifications necessary by the specific applications, or uses of the present invention. It is the purpose of the present invention to include all of its modifications and variations within the scope described in the report. | The present invention relates to a process of production of polyamide compounds with natural fibers and polyamide compounds with natural fibers, establishes the fact of using natural fiber to obtain a compound with mechanical properties close to the one obtained with inorganic loads by means of continuous process with extrusion and molding by injection process; the processes presented allows the obtainment, by means of injection, of finished products with precise dimensional and complex features; the fact that the compound with natural Curauá fiber presenting suitable mechanical properties combined to a lesser density than the compound with inorganic load is interesting to the automotive industry as vehicles manufactured with lighter parts consume less fuel. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for pretreatment of fibrous material for use in a cellulose production system. In particular, the invention relates to sand and liquor separation for the containment of fibers being processed in a continuous digester system.
BACKGROUND OF THE INVENTION
[0002] In the art of chemical pulping, natural cellulose material, such as soft wood chips, are treated to produce cellulose pulp from which paper and other products are made. The chips are typically treated in a chemical digester using a kraft cooking processing. The cooking process involves the use of cooking liquor, such as white liquor and black liquor (which is liquor with dissolved organic material (DOM)). The cooking liquors may be extracted from a digester vessel, treated, and recirculated back into the digestion process.
[0003] Conventional black liquor treatment processes normally include a sand separator that removes from the black liquor sand and other heavy particulate matter. In addition, an in-line drainer may be used to removes excess liquor and retain useful wood fibers and wood pins in the remaining liquor.
[0004] Conventional sand separators remove sand and other particles from a liquid stream, such as kraft cooking liquor being recirculated through a chip transport system in a cellulosic fiber continuous digester plant. A conventional sand separator is shown in U.S. Pat. No. 4,280,902. The sand separator generally includes a tangential inlet to a cylindrical tank. Sand and other heavy particles swirl downward in the tank to a strainer funnel through which the sand and particles pass into a collection basket. The liquid, which is free of particles and sand, is extracted from the sand separator through a center, top outlet port.
[0005] Conventional in-line drainers for cellulosic fiber digesting systems are shown in co-pending and commonly-owned U.S. Pat. No. ______ (now application Ser. No. 09/573,390 (NV 10-1309)) entitled “IN-LINE DRAINER ENHANCEMENTS”, and U.S. Pat. No. ______ (now application Ser. No. 09/573,046 (NV-10-1303)) entitled “FEEDING CELLULOSE MATERIAL TO A TREATMENT VESSEL,” both of which are incorporated by reference herein. In-line drainers are also disclosed in U.S. Pat. Nos. 5,536,366 and 5,401,361.
[0006] In the conventional use of an in-line drainer, the drainer is positioned in a feed system of a continuous digester, for example, downstream of the outlet of a sand separator (as shown by item 37 in FIG. 1 herein). The liquid passed to the drainer from the sand separator can typically contain at least some wood fibers, chip pins, fine particles or other material. The in-line drainer is typically used to remove excess liquid from the low-pressure liquor circulation associated with the chip feed system. Conventional drainers include cylindrical screen baskets fashioned from steel bars oriented parallel to the direction of flow so that the liquid passes through vertical slots or apertures while retaining wood particles within the circulation. However, the bars and slots may be angled with respect to the flow direction so as to avoid fibers that are parallel to the flow from slipping through bars (which slippage may occur with bars parallel to the flow).
[0007] In a conventional in-line drainer of the conventional art, the potential for chips, pins, and fines to align with and pass through the vertical slots of the drainer basket can be minimized by introducing a horizontal velocity component to the liquid flow as it is passes through the drainer. This is typically achieved by introducing a helical baffle, or so-called “flight”, to the inlet of the drainer in order to impart a helical flow to the liquid as it is introduced to the drainer and passes through the drainer basket. Due to this helical flow, any chips, pins, or fines that may be present are oriented in the direction of the helical flow and thus oriented obliquely to the elongation of the slots of the vertical bars. Thus, in the conventional art, the helical flight in the inlet reduces the tendency for chips, pins, and fines to pass through the drainer basket or to be lodged in the slots of the drainer basket and cause pluggage of the drainer.
[0008] The conventional wisdom of having a sand separator device and in-line drainer device as separate components has served reasonably well to achieve the desired removal of sand and heavy particulate matters from the black liquor and to drain excess liquid from the black liquor. These separate components have not previously been combined because they perform entirely different functions. The sand separator removes particles, such as sand, from a black liquor stream. In contrast, the in-line drainer strains excess liquor and retains small particles, such as fibers, in a black liquor stream. The removal of sand and other particles from the stream requires different mechanical components than does the removal of excess liquor. It has been conventionally believed that separate devices are needed to remove sand and to extract excess liquor. Typically, a filter device, such as a strainer that is designed to extract excess liquid, will become clogged if subjected to sand or heavy particles. It would have been counterintuitive to form a single device to both filter sand and heavy particles from a black liquor stream and at the same time be applied to remove excess liquid liquor.
SUMMARY OF THE INVENTION
[0009] The present invention combines a sand separator and in-line drainer to form a single device that performs both sand and heavy particle removal as well as extraction of excess liquor. Fine wood fibers flow through the device to the output. But, sand and excess liquor are extracted.
[0010] A combined sand separate with internal liquor removal as a single device provides a single compact component to replace two existing devices. By using the outlet flange and internal cylinder of the sand separator to receive a vertical in-line drain strainer, the overall height of the combined component is reduced as compared to the combined height of a sand separator and in-line strainer. The combined device is more compact and takes less volume than would separate sand separator and in-line strainer devices. In addition, a single combined device is believed to have an overall lower acquisition cost than would two separate devices. In particular, it is believed that a combined sand separator in-line drain strainer may be manufactured and sold at a lesser cost than the combined cost of a sand separator and conventional in-line drain strainer.
[0011] In one embodiment, the invention is a separation device for a cellulose fiber processing system comprising: a particle separation tank having an axis, an upper tangential stream inlet, and a lower particle outlet; an inline drainer column extending at least partially down into the tank and said drainer, wherein the drainer has an inlet within the tank and aligned with the axis of the tank, and the drainer has a clear fluid outlet and an outlet for a mixture of fluid and cellulose fiber.
[0012] In another embodiment, the invention is a method for separating particles and clear fluid from a stream of liquor in a cellulose fiber processing system, wherein said method uses a device having a tank and a drainer column extending down into the tank, said method comprising: injecting the stream of liquor into an upper inlet to the tank; swirling the liquor in the tank such that centrifugal forces move particles towards a perimeter of the tank and away from a centerline of the tank; collecting the particles in a lower portion of the tank; introducing relatively particle free cooking liquor into an inlet to the drainer, where the drainer inlet is within the tank and substantially aligned with the centerline of the tank; in the drainer filtering to separate clear liquor for the relatively particle free liquor which includes cellulose fibers and thereby form condensed relatively free particle free liquor; passing the clear liquor through a clear liquor output of the drainer, and passing the condensed relatively particle free liquor to an outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention is shown in the accompanying drawings which are:
[0014] [0014]FIG. 1 is a schematic diagram of a continuous digester system employing a prior art feed system having a separate sand separator and in-line drainer.
[0015] [0015]FIG. 2 is a schematic diagram of a chip transport system showing a combined sand separator and liquor drainer as a combined device between a chip bin and digester.
DETAILED DESCRIPTION OF THE INVENTION
[0016] [0016]FIG. 1 is an illustration of a typical chip feed system 10 for a continuous cellulose fiber digestion plant.
[0017] The term comminuted cellulosic fibrous material may take many forms, including sawdust; grasses, such as straw or kenaf; agricultural waste, such as bagasse; recycled paper; or sawdust, for the sake of simplicity. The term “chips” will be used here when referring to comminuted cellulosic fibrous material, including any and all of the listed materials, and other fibers not listed, that may be processed by the present invention. Also, though a continuous digester in shown in FIG. 1, it is understood that the present invention as also applicable to feeding several continuous digesters or one or more discontinuous or batch digesters.
[0018] Chips 12 are introduced to the feed system 10 , for example, via a conveyor (not shown) from a chip storage facility, for example, a woodyard, via an isolation and metering device 13 . Though various types of vessels are known in the art, chip bin 14 is preferably a DIAMONDBACK® Steaming vessel as marketed by Andritz Inc. of Glens Falls, N.Y. and described in U.S. Pat. Nos. 5,500,083; 5,617,975; 5,628,873; and 4,958,741, or a chisel-type vessel as described in U.S. Pat. No. 6,199,299. The pressure in the bin 14 may be slightly below atmospheric pressure or slightly above atmospheric pressure, that is, the pressure in the bin 14 may vary from about −1 to 2 bar gage (that is, about 0 to 3 bar absolute). Other conventional pressurized steam vessels and chip feed systems could be used as well.
[0019] The steamed chip material is discharged from the bottom of the chip bin 14 to a metering device 15 , for example, a star-type metering device or Chip Meter as sold by Andritz Inc. of Glens Falls, N.Y., though any type of meeting device may be used. The chips discharged by the metering device 15 are introduced to a vertical conduit or pipe 16 , for example, a Chip Tube sold by Andritz Inc. of Glens Falls, N.Y. Cooking chemical and other liquids are typically first introduced to the chips in conduit 16 by means of one or more conduits 17 such that a level of liquid is established in conduit 16 and a slurry of chips and liquid is present in the bottom of conduit 16 .
[0020] Conduit 16 discharges the slurry of chips and liquid by means of a radiused section 18 to the inlet of slurry pump 19 . The slurry pump 19 pressurizes and transfers the slurry in conduit 16 via conduit 18 to the low-pressure inlet 20 of a high-pressure transfer device 21 . The high-pressure feeder 21 includes a pocketed rotor mounted in a housing typically having a low-pressure inlet 20 , a low-pressure outlet 22 , a high-pressure inlet 23 and a high-pressure outlet 24 . The low-pressure outlet 22 typically includes a screen plate (not shown) which minimizes the passage of chips out of the low-pressure outlet while allowing the liquid in the slurry to pass out to conduit 25 . The chips form a mat on the screen plate, which functions as a much finer strainer, in a manner similar to wedge-wire screens. However, sand and heavy particles (and some chips) do pass through the low-pressure outlet and into the conduit 25 .
[0021] The liquid discharged from the low-pressure outlet 22 of high-pressure feeding device 21 passes via conduit 25 to a cyclone-type sand separator 30 which isolates undesirable material and debris, such as sand, stones, etc., from the liquid in conduit 25 . Liquid having little or no undesirable material or debris is discharged from separator 30 and is passed through in-line drainer liquor-separating device 31 via conduit 32 between the sand separator outlet and the inlet to the in-line drainer. At least some liquid is removed by the in-line drainer 31 via conduit 32 and sent to a level tank 33 . Liquid discharged from tank 33 via conduit 34 and pump 35 is supplied to the digester as liquor make-up.
[0022] The liquid, with some fibers and chip pins, discharged from the in-line drainer 31 into conduit 17 may be supplemented with cooking chemical, for example, kraft white, green, orange (that is, liquid containing polysulfide additives) or black liquor, introduced via conduit from a liquor surge tank (not shown). The system described above is a Lo-Level® Feed System marketed by Andritz Inc. of Glens Falls, N.Y. Other feed systems could also be used, those systems would involve separate devices for sand separator and in-line drainer.
[0023] The present invention combines the conventional sand separator 30 and in-line drainer 31 (as shown in FIG. 1 or from other conventional feed systems) into a single device. FIG. 2 shows a sand separator with internal liquid separation device 100 . The generally-vertical device includes a first in-line vertical drainer column 102 having an internal cylindrical arrangement of strainer bars 104 and coaxial with the cylindrical outer wall of the drainer column. The strainer bars 104 allow excess liquor to flow through to an interior passage 106 of the drainer and flow upstream to a clear liquor outlet 108 . The clear liquor outlet is in fluid communication with the interior passage 106 formed by the cylindrical arrangement of bars. The clear liquid output may be connected to line 32 in FIG. 1.
[0024] An outer annular volume 110 of the drainer column 102 is formed between the cylindrical strainer bars and the outer wall of the strainer 102 . In this outer volume 110 , black liquor, with pulp fines and pin chips, flow upwards through the column to a liquor and slurry output 112 . This output may be coupled to line 17 in FIG. 1.
[0025] A lower end of the strainer basket includes a spiral device 114 that imparts a swirl to the flow of the stream entering the drainer. The swirl flow prevents fine and pin chips from becoming caught between bars in the drainer. The spiral increases the suspension of the fines and pin chips in the slurry entering the drain column. The spiral is adjacent and downstream of the inlet 116 to the drainer cylinder. The inlet 116 to the drainer cylinder is contained within a cylindrical tank 118 that forms the sand separator portion of the combined device 100 . Approximately one-half of the length of the drainer column 102 may be housed within the sand separator tank 118 . The drainer 102 may be mounted vertically along the vertical axis 120 of the sand separator tank. The drainer may extend through the top of the tank 118 and down into the tank such that the inlet 116 to the drainer is about halfway down into the depth of the tank and aligned with the tank centerline 120 . Due to the swirl in the tank, sand and heavy particles do not flow towards the centerline of the tank. Rather, the centrifugal force imparted by the swirling flow moves sand and other heavy particles to the perimeter of the tank. Thus, the fluid in the tank along the centerline is relatively free of sand and particles.
[0026] Appropriate structural devices are used to mount the drain cylinder to the sand separator device. These structural devices may include flanges, braces and other support devices to hold the drainer column 102 vertically in the top of the tank 118 .
[0027] The tank 118 is a generally-cylindrical vessel having at an upper end a dirty liquor inlet 122 that receives dirty liquor mixed with sand, other heavy particles, wood fibers and pin chips, via line 25 shown in FIG. 1. The dirty liquor inlet is in communication with the low-pressure output 22 of a high-pressure feeder 21 from a downstream portion of the chip transport system.
[0028] Dirty liquor enters the top of the sand separator tank 118 and settles within the tank. The dirty liquor enters the tank tangentially, and swirls around the tank. As the stream of dirty liquor swirls in the tank, sand and other large particles sink towards the bottom of the sand separator tank. The bottom of the tank may include a conical lower section 124 that funnels down towards a funnel strainer 126 at the bottom of the tank. The funnel has perforations 128 on its conical outer surface. These perforations are sufficiently large that sand and other large particles flow through them and into a sand basket 130 that forms a lower outer housing to the bottom of the tank and surrounds the funnel. The housing has a sand discharge port 132 .
[0029] In operation, the dirty liquor inlet 122 , which is mounted tangentially to the circular wall of the tank, allows dirty liquor to flow with some velocity into the tank. As the liquor enters the tank, it swirls around the tank. Heavy particles and sand contained within the dirty liquor tend to fall due to the force of gravity towards the bottom of the tank. As the sand and heavy particles swirl in the tank, they are propelled due to centrifugal forces to the outer periphery of the tank. As the sand and heavy particles flow along the outer surface of the tank, they ultimately drop down in the tank to the sand funnel 126 . The perforations 128 in the outer circumference of the sand funnel allow the sand and other heavy particles to flow through the perforations and into the lower housing and sand catcher 130 . As the sand catcher fills, the sand and other heavy particles may be removed via an outlet 132 to the housing.
[0030] In the tank of the sand separator, the liquor in the upper portions of the tank, especially along the centerline axis of the tank, is relatively free of sand and other heavy particles. The inlet 116 to the drainer column is oriented in the sand tank 118 along the centerline 120 of the tank and towards the upper half of the tank. Thus, the inlet to the in-line drain is positioned in the sand tank such as to receive dirty liquor which is relatively free of sand and heavy particles.
[0031] By positioning the inlet 116 to the in-line drainer at the center upper portion of the sand tank, the in-line drainer may be housed at least partially within the sand tank. The combined in-line drain and sand separator form a compact unitary device to perform the separate functions of sand removal and excess liquor removal.
[0032] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A separation device is disclosed for a cellulose fiber processing system comprising: a particle separation tank having an axis, an upper tangential stream inlet, and a lower particle outlet; an inline drainer column extending at least partially down into the tank and said drainer, wherein the drainer has an inlet within the tank and aligned with the axis of the tank, and the drainer has a clear fluid outlet and an outlet for a mixture of fluid and cellulose fiber. | 3 |
FIELD OF THE INVENTION
The present invention relates to an apparatus for synthesizing musical tones which resemble those produced by conventional (hereinafter referred to as natural) musical instruments, in particular, the decaying sounds of string type instruments.
BACKGROUND ART
Methods are known for synthesizing musical tones by means of modelling and reproducing the vibrational modes of various musical instruments. For example, to simulate the decaying sounds of a plucked string instrument, such as guitars, or of a struck string instrument, such as pianos, a closed-loop electric circuit can be used, consisting of a delay simulation circuit to represent the propagation modes of vibrating strings, and a low-pass filter circuit to represent acoustic decay of vibrating strings.
When such a circuit is excited with an input signal, representing an impact of a hammer striking a string, the excitation signal can be made to loop around the circuit to simulate the resonance vibration of the string. In such a circuit, the excitation signal undergoes decay, caused by the action of low-pass filters, to simulate the natural decay of a sound of an activated string. The decayed signal can be reproduced electrically to generate a musical tone to simulate the type of sound made by the natural instrument. Such techniques are disclosed in Japanese Patent Application Laid-Open Nos. S52-73721 and S63-40199.
In real situations, however, the natural musical tone colors generated by natural instruments display a variety of tone envelopes depending on the initial and residual touching modes, in the case of pianos and likewise for guitars, depending on such factors as the manner of plucking and the hardness of a pick.
Therefore, the present technology of simple adjustments of low-pass filters in a closed-loop circuit is inadequate for faithful reproduction of complex tone envelopes generated by natural instruments.
SUMMARY OF THE PRESENT INVENTION
The purpose of the present invention is to provide a musical tone synthesizing apparatus which enables generation of sounds whose tone envelopes are freely adjustable.
The invented musical tone synthesizing apparatus produces a tone according to a play of a note which initiates an external electrical input signal to an excitation signal generating device, which outputs a predetermined excitation signal to a signal processing device which is electrically connected, in a closed loop circuit, to the excitation signal generation device. The signal processing steps include controllable delays in the phase angle and controllable variations in the amplitude of the feedback signal. By controlling the loop gain of said feedback signal in accordance with the time duration of said play, and by superimposing the real-time play mode of said external input signal, a rich musical tone having a controllable complex tone envelope is generated from the musical tone generator to simulate the tone color of conventional musical instruments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a first embodiment of this invention, showing the various components of the tone synthesizing apparatus.
FIG. 2 is an example of a data table for tone color generation.
FIGS. 3 to 6 show flow charts for the various component circuits.
FIG. 7 illustrates an example of wave forms and of a tone envelope.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of this invention is explained in the following with reference to Figures presented above.
FIG. 1 is a schematic block diagram showing the various components of the tone synthesizing apparatus. As shown in this figure, the apparatus comprises a microprocessor 1 which controls various component circuits of the apparatus, a timer 2, parameter memory array 3, manually operable switch section 4 (hereinafter referred to as switch section 4), playing mode input section 5 (hereinafter referred to as touching section 5) and a musical tone generator 6.
Microprocessor 1 controls the timing of timer 2 which supplies interrupt signals to the microprocessor at regular time intervals. The switch section 4 is connected to a playing mode switch of a keyboard (not shown) which transmits information concerning the playing modes to the microprocessor 1. When a key/chord is played, the touching section 5 analyzes the manner of initial and residual touching information, and constructs playing mode data, which are supplied to both the microprocessor 1 and the musical tone generator 6.
Parameter memory array 3 contains all the necessary data regarding the musical tone generation, such as delay coefficients, decay data table, coefficients for filtering computation and other parameters essential for musical tone generation. The data from the parameter memory array 3 such as key-on event transmitted through the switch section 4 and other parameters corresponding to playing mode data, are supplied to the microprocessor 1, and to the musical tone generator 6.
The musical tone generator 6 comprises an adder 61, a delay circuit 62, a closed-loop circuit 60 consisting of a multiplier 63 and digital filters 64, an excitation signal generator 65 and an adder 66. The excitation signal generator 65 contains wave form memory section which stores many excitation signals of a wide variety of frequencies, including impulse wave forms, for example. When the microprocessor 1 commands a tone generation, the excitation signal generator 65 begins receiving various excitation wave forms stored in wave form memory section. These memory wave forms are compared against the inputted playing mode data, representing the style of key/chord pressing and touching, from the touching section 5 of the keyboard, and appropriate data are inputted into the multiplier 66. The results are then transmitted to one end of the input terminals of the adder 61.
The output signals from the adder 61 are fed back to the other end of the terminal of the adder after going through the delay circuit 62, the multiplier 63 and the filters 64. Therefore, once the excitation wave forms, generated by the excitation signal generator 65 and transmitted through the multiplier 66, are introduced into the closed-loop circuit 60, they begin circulating (looping) around within this circuit.
The delay circuit 62 comprises, for example, shift registers to create delaying effects of the input signals, and selectors to output appropriate signals selected from the delayed signals. The delay time is decided by the delay coefficients calculated by the microprocessor 1. The delay time requirement for the circuit 62 is set s that the time required for the signal to make a complete loop around the circuit 60 is equal to the value of the inverse of the first resonance frequency of the tone to be generated.
The decay coefficients for the multiplier 63 are determined and progressively altered, by the microprocessor 1, according to the elapsed time, measured from the instant of the tone generation. As a result, a tone envelop such as the one shown in FIG. 7 is achieved, which shows the time-dependent variations of the amplitude of vibration as the musical tone signal is made to loop around the closed-loop circuit 60.
The parameter memory array 3 includes decay data tables for determining the decay coefficients; for example, a portion of such a table is illustrated in FIG. 2. Each table consists of alternating sets of a decay coefficient, fg, accompanied by its duration, t, as fg 1 , t 1 , fg 2 , t 2 , fg 3 , t 3 , . . . fg n , t n and so on. The last coefficient in the table, fg n , is for use after the key-release.
The parameter memory array 3 contains a variety of decay data reference tables to correspond with a variety of requirements dealing with the tone pitch, initial touch and residual touch and so on, representing a variety of playing conditions. Microprocessor 1 computes an index, INDX, for use in data-seach in the decay table array, according to parametric requirements, determined by both the key code and key-on event triggered by the switch section 4, and by the real-time playing data collected by the touching section 5. The contents of the decay data table, INDX, is read by the microprocessor 1 and delivered in successive order to the multiplier 63, to carry out the task of switching the decay coefficients.
Filter 64 simulates acoustic loss of string sounds, and comprises low-pass filters, for example finite impulse response digital filter (FIR), and the coefficients for computation of acoustic loss are performed by the microprocessor 1. The reference coefficients for filters are also stored in the parameter memory array 3, corresponding to a variety of parametric requirements of the various key code. The appropriate parametric data for the key code (being played) are read off the memory array 3 and are applied to the filter 64, as required.
The operation of the musical tone synthesizer is explained below with reference t flow charts shown in FIGS. 3 to 6
When the power switch for the apparatus is turned on, the microprocessor 1 proceeds to step S1 of the main routine program shown in FIG. 3. The microprocessor 1 initializes all the registers, flags and other memory cells used for the control function contained within its internal memory. Thereafter, it repeats other processes for other function keys, such as the key routine (step S2) and for other ancillary function keys such as manually operable tone switch, volume control switch, and others in step 3 (S3).
In step S2, the key routine is activated, and the tone generation program routine (hereinafter referred to as the routine) proceeds to step S11 as shown in FIG. 4. In this step, various key action events on the keyboard, transmitted through the switch section 4, are recorded in the shift registers. Proceeding onto step S12, the microprocessor 1 checks whether the key event is the key-on event or not. If the keyboard is not turned on, the routine routes to "NO" and proceeds to step S19 to check whether the key-off event is operated by the switch section 4. If the key is not turned-off, both steps S12 and S19 route to "NO", and the routine returns to step S3 of the main routine, and repeats the above process of scanning for the status of other function keys.
When a key (not shown in FIG. 4) is operated to turn on the apparatus, the steps S11 to S12 in the key routine shown in FIG. 4 are activated. The control takes the "YES" route to step S13, where the key-on flag KON is set to "1" to indicate that the key is being depressed. At this point in step 14, a reference delay coefficient corresponding to the sound of the key code of the key (being depressed) is read out of the delay coefficient memory array 3, and inputted into the delay circuit 62. Proceeding onto step S15, an INDX table is set up to record the playing data, based on the reference key code and touch data of the touching section 5, to determine the decay coefficient for a musical key being played. In step S16, the parameter count PC in the decay reference data table are set to P=0, and in step S17, the microprocessor 1 activates the coefficient-determining routine shown in FIG. 5.
The coefficient-determining routine of the routine begins at step S31 shown in FIG. 5. The microprocessor reads out a parameter value to correspond with the appropriate parameter count PC from the reference decay data memory array 3, in this case, PC=0 in FIG. 4. The result is a storage, in the microprocessor 1, of the first decay coefficient, fg 1 , of the initial tone generation stage. In the next step S32, the chosen parameter, fg 1 , is entered into the multiplier 63. In the next step S33, the PC is incremented by one and the control proceeds to step S34, where the microprocessor 1 reads out a time value, t 1 , corresponding to PC=1 from the decay data array. This time value is stored temporarily in a register, to serve as a time marker TM to measure the elapsed time between the TM event and the next event.
The control proceeds to step S35, which tests whether or not the data in step S34 are the last data in the decay data table. This is made possible because there is stored a last decay data in each of the reference decay memory array, distinguishable clearly from the rest of the data by the extraordinary length of elapsed time associated with it. By this means, it is possible to judge whether or not the data read in the step S34 are complete. When the test result is "NO", the microprocessor 1 goes on to step S36 to increment the PC by one to repeat the key routine as shown in FIG. 4.
When the control reaches step S18 in FIG. 4, a tone generation command is issued to the excitation signal generator 65. The resulting wave data produced by the excitation signal generator 65 are multiplied in the multiplier 66 by the respective multiplier coefficients corresponding to the touch data and are then inputted to the closed-loop circuit 60, via the adder 61. The signal loops around within the circuit 60 while the signal level is being decremented gradually according to the decay coefficients, fg 1 , given to the multiplier 63 (refer to FIG. 7). Once the key subroutine is completed at step S18, the routine returns to step S3 of the main routine.
Throughout the above process, the control can interrupt any of the routine processing steps by means of the interrupt subroutine shown in FIG. 6. The interrupt subroutine is triggered by the interrupt signal from the timer 2. The microprocessor 1 upon receiving the interrupt signal proceeds to step S41, and examines whether or not the key-on flag KON is "1". In this case of "YES" the routine proceeds to step S42 to decrement the TM, and in step S43 it examines whether or not the TM=0, that is, whether sufficient time has elapsed to input another decay signal. In the case of "NO", the routine discontinues the interruption subroutine, and returns to the main routine. From this point on, every time an interrupt signal is generated, the time marker TM is decremented.
In step S42 of the above interrupt routine process, shown in FIG. 6, if the time marker becomes TM=0, then the routine routes to "YES" in step S43 and proceeds onto step S44 to carry out the coefficient generation subroutine shown in FIG. 5. The resulting new decay coefficient fg 2 is read out of the memory array 3 in step S31, and is applied to the multiplier 63 in step S32. Accordingly, a new time value t 2 is generated and stored as a new TM in step S34. The tone signal looping around in the closed circuit 60 is made to decay gradually, during the time interval t 2 , according to the decay coefficient fg 2 (refer to FIG. 7). From this point on, the control repeats the processes of replacing decay coefficients, fg k (where k=3, 4, . . . , n-1) read off the decay memory array and their accompanying elapsed time values t k (where k=3, 4, . . . , n-1), to be applied to the computation of tone signal decay.
In step S35 of the coefficient generation subroutine, when the data read is the last decay memory data, then the routine routes to "YES", and proceeds to step S37 to turn the key-on flag KON to "0". As a result, even if the interrupt subroutine is activated at this stage, the routine stops at step S41, because the key-on flag in step S41 would route to "NO". From this point on, the musical tone decays according to the final-entry decay coefficient, fg n .
When a play is ended by releasing the key, a key-off signal is send to microprocessor 1 to activate the key routine shown in FIG. 4. The routine routes to step S19 via steps S11 and S12, at which step it proceeds to step S20 through the "YES" flag to turn the key-on flag to "0". The routine proceeds onto step S21 to set the final decay coefficient, fg n in the multiplier 63 to generate a musical tone appropriate for signing-off.
The tone signals, processed according to the above described steps involved within the closed-loop circuit 60, are outputted ultimately from the adder 61 to a sound reproduction system (not shown) which reproduces synthesized musical sounds.
A second preferred embodiment is described next. In the first preferred embodiment, with the passage of time t 1 , t 2 , . . . , the decay coefficients fg 1 , fg 2 . . . are altered in discrete steps. In the second preferred embodiment, the decay coefficients are not held constant during a given time period but are made to decay continuously at some rate during this time period in order to reproduce a musical tone having a complex tone envelope. | A musical tone generating apparatus comprises an excitation signal generator, a signal processing device and loop gain controller. The signal processing device is electrically connected in a closed feedback loop with the excitation signal generator, via a delay unit. The loop gain controller controls gain of said closed feedback loop according to a lapse of time. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to integrated circuit manufacturing, and more particularly to insulated-gate field-effect transistors.
2. Description of Related Art
An insulated-gate field-effect transistor (IGFET), such as a metal-oxide semiconductor field-effect transistor (MOSFET), uses a gate to control an underlying surface channel joining a source and a drain. The channel, source and drain are located in a semiconductor substrate, with the source and drain being doped oppositely to the substrate. The gate is separated from the semiconductor substrate by a thin insulating layer such as a gate oxide. The operation of the IGFET involves application of an input voltage to the gate, which sets up a transverse electric field in the channel in order to modulate the longitudinal conductance of the channel.
In typical IGFET processing, the source and drain are formed by introducing dopants of second conductivity type (P or N) into a semiconductor substrate of first conductivity type (N or P) using a patterned gate as a mask. This self-aligning procedure tends to improve packing density and reduce parasitic overlap capacitances between the gate and the source and drain.
Polysilicon (also called polycrystalline silicon, poly-Si or poly) thin films have many important uses in IGFET technology. One of the key innovations is the use of heavily doped polysilicon in place of aluminum as the gate. Since polysilicon has the same high melting point as a silicon substrate, typically a blanket polysilicon layer is deposited prior to source and drain formation, and the polysilicon is anisotropically etched to provide a gate which provides a mask during formation of the source and drain by ion implantation. Thereafter, a drive-in step is applied to repair crystalline damage and to drive-in and activate the implanted dopant.
As IGFET dimensions are reduced and the supply voltage remains constant (e.g., 3V), the electric field in the channel near the drain tends to increase. If the electric field becomes strong enough, it can give rise to so-called hot-carrier effects. For instance, hot electrons can overcome the potential energy barrier between the substrate and the gate insulator thereby causing hot carriers to become injected into the gate insulator. Trapped charge in the gate insulator due to injected hot carriers accumulates over time and can lead to a permanent change in the threshold voltage of the device.
A number of techniques have been utilized to reduce hot carrier effects. One such technique is a lightly doped drain (LDD). The LDD reduces hot carrier effects by reducing the maximum lateral electric field. The drain is typically formed by two ion implants. A light implant is self-aligned to the gate, and a heavy implant is self-aligned to the gate on which sidewall spacers have been formed. The spacers are typically oxides or nitrides. The purpose of the lighter first dose is to form a lightly doped region of the drain (or LDD) at the edge near the channel. The second heavier dose forms a low resistivity heavily doped region of the drain, which is subsequently merged with the lightly doped region. Since the heavily doped region is farther away from the channel than a conventional drain structure, the depth of the heavily doped region can be made somewhat greater without adversely affecting the device characteristics. The lightly doped region is not necessary for the source (unless bidirectional current is used), however lightly doped regions are typically formed for both the source and drain to avoid additional processing steps.
Disadvantages of LDDs include increased fabrication complexity and increased parasitic resistance due to their light doping levels. During operation, LDD parasitic resistance decreases drain current. Linear drain current (i.e., drain current in the linear or triode region) is reduced by the parasitic resistance in both the source and drain. Saturation drain current (i.e., drain current in the saturation region) is largely unaffected by the parasitic resistance of the drain but greatly reduced by the parasitic resistance of the source. Therefore, saturation drain current can be improved while reducing hot carrier effects by providing a lightly doped region only on the drain side. That is, the drain includes lightly and heavily doped regions, and the entire source is heavily doped.
Asymmetrical IGFETs (with asymmetrically doped sources and drains) are known in the art. For instance, U.S. Pat. No. 5,424,229 entitled "Method For Manufacturing MOSFET Having An LDD Structure" by Oyamatsu discloses providing a mask with an opening over a substrate, implanting a dopant through the opening at an angle to the substrate to form a lightly doped drain region on one side without a corresponding source region on the other side, forming a gate in the opening which overlaps the lightly doped drain region, removing the mask, and implanting heavily doped source and drain regions using the gate as an implant mask. As another example, U.S. Pat. No. 5,286,664 entitled "Method For Fabricating The LDD-MOSFET" by Horiuchi discloses forming a gate, implanting lightly doped source and drain regions using the gate as an implant mask, forming a photoresist layer that covers the source side and exposes the drain side, depositing a single spacer on the drain side using liquid phase deposition (LPD) of silicon dioxide, stripping the photoresist, and implanting heavily doped source and drain regions using the gate and single spacer as an implant mask.
A drawback to these and other conventional asymmetrical IGFETs is that the heavily doped source and drain regions typically have identical dopant concentrations. Although the doping concentration of the heavily doped drain region may be constrained in order to reduce hot carrier effects, the doping concentration of the heavily doped source region need not be constrained in this manner. Furthermore, increasing the doping concentration of the heavily doped source region reduces the source-drain series resistance, thereby improving drive current.
Complementary metal-oxide semiconductor (CMOS) circuits typically include adjacent N-channel (NMOS) and P-channel (PMOS) devices. Since CMOS inverter circuits use very little power, CMOS is particularly useful in very large-scale integrated (VLSI) circuits where even small power dissipation in each transistor becomes a problem when thousands or millions of transistors are integrated on a chip. CMOS processes typically use N-well and P-well masks early in the processing sequence to define N-type and P-type active regions. CMOS processes also typically include a single masking step for forming the gates, separate masking steps for implanting lightly doped N-type source/drain regions into the P-type active region and lightly doped P-type source/drain regions into the N-type active region, formation of oxide spacers adjacent to the gates, and then separate masking steps for implanting heavily doped N-type source/drain regions into the P-type active region and heavily doped P-type source/drain regions into the N-type active region.
Accordingly, a need exists for improved asymmetrical N-channel and P-channel IGFETs that reduce both source-drain series resistance and hot carrier effects.
SUMMARY OF THE INVENTION
The present invention provides an asymmetrical N-channel IGFET and an asymmetrical P-channel IGFET. One or both IGFETs include a lightly doped drain region, heavily doped source and drain regions, and an ultra-heavily doped source region. Preferably, the lightly doped drain region and the heavily doped source region provide channel junctions, and the heavily doped drain region and the ultra-heavily doped source region are spaced from the channel junctions. Advantageously, one or both IGFETs have low source-drain series resistance and reduce hot carrier effects.
By definition, the dopant concentration of the ultra-heavily doped source region exceeds that of the heavily doped source and drain regions, and the dopant concentration of the heavily doped source and drain regions exceeds that of the lightly doped drain region. Furthermore, the heavily doped source and drain regions need not have similar dopant concentrations.
Preferably, both the N-channel and P-channel IGFETs include a source that consists of heavily doped and ultra-heavily doped source regions, and a drain that consists of the lightly doped and heavily doped drain regions. It is also preferred that the dopant concentration of the ultra-heavily doped source regions is in the range of 1.5 to 10 times that of the heavily doped source and drain regions, and the dopant concentration of the heavily doped source and drain regions is in the range of 10 to 100 times that of the lightly doped drain regions, and furthermore that the dopant concentration of the lightly doped drain regions is in the range of about 1×10 17 to 5×10 18 atoms/cm 3 , the dopant concentration of the heavily doped source and drain regions is in the range of about 1×10 19 to 1×10 20 atoms/cm 3 , and the dopant concentration of the ultra-heavily doped source regions is in the range of about 1.5×10 19 to 1×10 21 atoms/cm 3 .
In accordance with an aspect of the invention, a method of making asymmetrical N-channel and P-channel IGFETs includes providing a semiconductor substrate with a first active region of first conductivity type and a second active region of second conductivity type adjacent to an isolation region.
Forming a first IGFET includes forming a first gate with first and second opposing sidewalls over the first active region, applying a first ion implantation of second conductivity type to implant first lightly doped source and drain regions into the first active region, applying a second ion implantation of second conductivity type to convert substantially all of the first lightly doped source region into a first heavily doped source region without doping the first lightly doped drain region, forming first and second spacers adjacent to the first and second sidewalls, respectively, and applying a third ion implantation of second conductivity type to convert a portion of the first heavily doped source region outside the first spacer into a first ultra-heavily doped source region without doping a portion of the first heavily doped source region beneath the first spacer, and to convert a portion of the first lightly doped drain region outside the second spacer into a first heavily doped drain region without doping a portion of the first lightly doped drain region beneath the second spacer. A first source in the first active region includes the first heavily doped and ultra-heavily doped source regions, and a first drain in the first active region includes the first lightly doped and heavily doped drain regions.
Forming a second IGFET includes forming a second gate with third and fourth opposing sidewalls over the second active region, applying a first ion implantation of first conductivity type to implant second lightly doped source and drain regions into the second active region, forming third and fourth spacers adjacent to the third and fourth sidewalls, respectively, applying a second ion implantation of first conductivity type to convert a portion of the second lightly doped source region outside the third spacer into a second heavily doped source region without doping a portion of the second lightly doped source region beneath the third spacer, and to convert a portion of the second lightly doped drain region outside the fourth spacer into a second heavily doped drain region without doping a portion of the second lightly doped drain region beneath the fourth spacer, removing at least portions of the third and fourth spacers, and applying a third ion implantation of first conductivity type to convert the second heavily doped source region into a second ultra-heavily doped source region and to convert substantially all of the second lightly doped source region into a third heavily doped source region without doping the second lightly and heavily doped drain regions. A second source in the second active region includes the third heavily doped and the second ultra-heavily doped source regions, and a second drain in the second active region includes the second lightly doped and heavily doped drain regions.
Preferably, the method includes forming an insulating layer over the substrate to provide first, second, third and fourth sidewall insulators adjacent to the first, second, third and fourth sidewalls, respectively, depositing a blanket layer of insulative spacer material on the insulating layer, and applying an anisotropic etch such that first, second, third and fourth insulative spacers are adjacent to the first, second, third and fourth sidewall insulators, respectively. In this manner, the first spacer includes the first sidewall insulator and the first insulative spacer, the second spacer includes the second sidewall insulator and the second insulative spacer, the third spacer includes the third sidewall insulator and the third insulative spacer, and the fourth spacer includes the fourth sidewall insulator and the fourth insulative spacer. Removing at least portions of the third and fourth spacers is accomplished by removing the insulative spacers without removing the sidewall insulators.
Another aspect of the method includes forming the first and second gates, forming a first photoresist layer that covers the second active region, applying the first ion implantation of second conductivity type using the first photoresist layer and the first gate as an implant mask, forming a second photoresist layer that covers the first active region, applying the first ion implantation of first conductivity type using the second photoresist layer and the second gate as an implant mask, forming the insulating layer, forming a third photoresist layer that covers the second active region and the first lightly doped drain region, applying the second ion implantation of second conductivity type using the third photoresist layer and the first sidewall insulator and a portion of the first gate as an implant mask, forming the insulative spacers, forming a fourth photoresist layer that covers the second active region, applying the third ion implantation of second conductivity type using the fourth photoresist layer and the first gate and the first and second spacers as an implant mask, forming a fifth photoresist layer that covers the first active region, applying the second ion implantation of first conductivity type using the fifth photoresist layer and the second gate and the third and fourth spacers as an implant mask, removing the insulative spacers, forming a sixth photoresist layer that covers the fast active region and the second lightly and heavily doped drain regions, and applying the third ion implantation of first conductivity type using the sixth photoresist layer and the third sidewall insulator and a portion of the second gate as an implant mask.
These and other aspects, features and advantages of the invention will be further described and more readily apparent from a review of the detailed description of the preferred embodiments which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of the preferred embodiments can best be understood when read in conjunction with the following drawings, in which:
FIGS. 1A-1U show cross-sectional views of successive process steps for making an asymmetrical N-channel IGFET and an asymmetrical P-channel IGFET in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, depicted elements are not necessarily drawn to scale and like or similar elements may be designated by the same reference numeral throughout the several views.
In FIG. 1A, silicon substrate 102 suitable for integrated circuit manufacture includes P-type epitaxial layer 104. Preferably, epitaxial layer 104 is disposed on a P+ base layer (not shown). Substrate 102 also includes P- active region 106 and N- active region 108 adjacent to a planar top surface. Active region 106 has a boron background concentration on the order of 1×10 16 atoms/cm 3 , a <100> orientation and a resistivity of 12 ohm-cm, and active region 108 has an arsenic background concentration on the order of 1×10 16 atoms/cm 3 , a <100> orientation and a resistivity of 12 ohm-cm. Trench oxide 110, composed of silicon dioxide (SiO 2 ), provides dielectric isolation between active regions 106 and 108. Gate oxide 112, composed of silicon dioxide, is formed on the top surface of substrate 102 using tube growth at a temperature of 700° to 1000° C. in an O 2 containing ambient. Gate oxide 112 has a thickness of 50 angstroms. Thereafter, a blanket layer of undoped polysilicon 114 is deposited by low pressure chemical vapor deposition (LPCVD) on the top surface of gate oxide 112. Polysilicon 114 has a thickness of 2000 angstroms. If desired, polysilicon 114 can be doped in situ as deposition occurs, or doped before a subsequent etch step by implanting arsenic with a dosage in the range of 1×10 15 to 5×10 15 atoms/cm 2 and an energy in the range of 2 to 80 kiloelectron-volts. However, it is generally preferred that polysilicon 114 be doped during an implantation step following a subsequent etch step.
In FIG. 1B, photoresist 116 is deposited as a continuous layer on polysilicon 114 and selectively irradiated using a photolithographic system, such as a step and repeat optical projection system, in which I-line ultraviolet light from a mercury-vapor lamp is projected through a first reticle. Thereafter, photoresist 116 is developed and the irradiated portions are removed to provide openings in photoresist 116. The openings expose portions of polysilicon 114, thereby defining first and second gates.
In FIG. 1C, an anisotropic etch is applied that removes the exposed portions of polysilicon 114 and the underlying portions of gate oxide 112. Preferably, a first dry etch is applied that is highly selective of polysilicon, and a second dry etch is applied that is highly selective of silicon dioxide, using photoresist 116 as an etch mask. After etching occurs, the remaining portions of polysilicon 114 and gate oxide 112 above active region 106 provide polysilicon gate 120 with opposing vertical sidewalls 122 and 124 on gate oxide 126, and polysilicon gate 130 with opposing vertical sidewalls 132 and 134 on gate oxide 136. Polysilicon gate 120 has a length (between sidewalls 122 and 124) of 3500 angstroms, and polysilicon gate 130 has a length (between sidewalls 132 and 134) of 3500 angstroms.
In FIG. 1D, photoresist 116 is stripped, photoresist 138 is deposited as a continuous layer over substrate 102 and selectively irradiated using the photolithographic system and a second reticle, and the irradiated portions are removed to provide an opening in photoresist 138. The opening is above active region 106, and photoresist 138 covers active region 108.
In FIG. 1E, lightly doped source and drain regions 140 and 142 are implanted into active region 106 by subjecting the structure to ion implantation of phosphorus, indicated by arrows 144, at a dose in the range of 1×10 13 to 5×10 14 atoms/cm 2 and an energy in the range of 2 to 35 kiloelectron-volts. Polysilicon gate 120 and photoresist 138 provide an implant mask for the underlying portion of substrate 102. As a result, lightly doped source and drain regions 140 and 142 are substantially aligned with sidewalls 122 and 124, respectively. Lightly doped source and drain regions 140 and 142 are doped N- with a phosphorus concentration in the range of about 1×10 17 to 5×10 18 atoms/cm 3 .
In FIG. 1F, photoresist 138 is stripped, photoresist 146 is deposited as a continuous layer over substrate 102 and selectively irradiated using the photolithographic system and a third reticle, and the irradiated portions are removed to provide an opening in photoresist 146. The opening is above active region 108, and photoresist 146 covers active region 106.
In FIG. 1G, lightly doped source and drain regions 150 and 152 are implanted into active region 108 by subjecting the structure to ion implantation of boron difluoride (BF 2 ), indicated by arrows 154, at a dose in the range of 1×10 13 to 5×10 14 atoms/cm 2 and an energy in the range of 2 to 35 kiloelectron-volts. Polysilicon gate 130 and photoresist 146 provide an implant mask for the underlying portion of substrate 102. As a result, lightly doped source and drain regions 150 and 152 are substantially aligned with sidewalls 132 and 134, respectively. Lightly doped source and drain regions 150 and 152 are doped P- with a boron concentration in the range of about 1×10 17 to 5×10 18 atoms/cm 3 .
In FIG. 1H, photoresist 146 is stripped, and oxide layer 160 is deposited over substrate 102 using a low temperature deposition process. Oxide layer 160 has a thickness in the range of 100 to 500 angstroms. Oxide layer 160 includes sidewall oxide 162 adjacent to sidewall 122, sidewall oxide 164 adjacent to sidewall 124, sidewall oxide 166 adjacent to sidewall 132, and sidewall oxide 168 adjacent to sidewall 134.
In FIG. 1I, photoresist 170 is deposited as a continuous layer over substrate 102 and selectively irradiated using the photolithographic system and a fourth reticle, and the irradiated portions are removed to provide an opening in photoresist 170. The opening is above lightly doped source region 140, sidewall oxide 162, and a first portion of polysilicon gate 120 adjacent to sidewall 122. Photoresist 170 covers lightly doped drain region 142, sidewall oxide 164, a second portion of polysilicon gate 120 adjacent to sidewall 124, and active region 108.
In FIG. 1J, substantially all of lightly doped source region 140 is converted into heavily doped source region 172 by subjecting the structure to ion implantation of arsenic, indicated by arrows 174, at a dose of 4.5×10 15 atoms/cm 2 and an energy in the range of 10 to 80 kiloelectron-volts. Photoresist 170 and sidewall oxide 162 and the first portion of polysilicon gate 120 (outside photoresist 170) provide an implant mask for the underlying portion of substrate 102. As a result, heavily doped source region 172 is substantially aligned with sidewall oxide 162 on the side opposite polysilicon gate 120, and lightly doped drain region 142 is essentially unaffected. Heavily doped source region 172 is doped N+ with an arsenic concentration in the range of about 1×10 19 to 1×10 20 atoms/cm 3 . Preferably, the dopant concentration of heavily doped source region 172 is at least 10 times that of lightly doped drain region 142. As is seen, a very small portion of lightly doped source region 140 remains beneath sidewall oxide 162.
In FIG. 1K, photoresist 170 is stripped, and a tube anneal on the order of 850° C. for 60 minutes is applied to remove crystalline damage and to drive-in and activate the implanted dopants. As a result, heavily doped source region 172 diffuses into and essentially eliminates lightly doped source region 140. Furthermore, heavily doped source region 172 and lightly doped drain region 142 diffuse slightly beneath sidewalls 122 and 124, respectively, and lightly doped source region 150 and lightly doped drain region 152 diffuse slightly beneath sidewalls 132 and 134, respectively.
In FIG. 1L, a blanket layer of silicon nitride (Si 3 N 4 ) with a thickness of 2500 angstroms is conformally deposited over the exposed surfaces by plasma enhanced chemical vapor deposition (PECVD) at a temperature in the range of 300° to 800° C. Thereafter, the structure is subjected to an anisotropic etch, such as a reactive ion etch, that is highly selective of silicon nitride with respect to silicon dioxide. The anisotropic etch forms nitride spacers 176, 178, 180 and 182 adjacent to sidewall oxides 162, 164, 166 and 168, respectively. Nitride spacers 176, 178, 180 and 182 each extend 1200 angstroms across substrate 102. Moreover, sidewall oxide 162 and nitride spacer 176 collectively form a source-side spacer for the active region 106, sidewall oxide 164 and nitride spacer 178 collectively form a drain-side spacer for active region 106, sidewall oxide 166 and nitride spacer 180 collectively form a source-side spacer for active region 108, and sidewall oxide 168 and nitride spacer 182 collectively form a drain-side spacer for active region 108.
In FIG. 1M, photoresist 184 is deposited as a continuous layer over substrate 102 and selectively irradiated using the photolithographic system and the second reticle, and the irradiated portions are removed to provide an opening in photoresist 184. The opening is above active region 106, and photoresist 184 covers active region 108.
In FIG. 1N, a portion of heavily doped source region 172 outside oxide sidewall 162 and nitride spacer 176 is converted into ultra-heavily doped source region 186, and a portion of lightly doped drain region 142 outside oxide sidewall 164 and nitride spacer 178 is converted into heavily doped drain region 188 by subjecting the structure to ion implantation of arsenic, indicated by arrows 190, at a dose in the range of 2×10 15 to 3×10 15 atoms/cm 2 and an energy in the range of 20 to 80 kiloelectron-volts. Polysilicon gate 120, sidewall oxides 162 and 164, nitride spacers 176 and 178, and photoresist 184 provide an implant mask for the underlying portion of substrate 102. As a result, ultra-heavily doped source region 186 is substantially aligned with nitride spacer 176 on the side opposite sidewall oxide 162, and heavily doped drain region 188 is substantially aligned with nitride spacer 178 on the side opposite sidewall oxide 164. Furthermore, the portion of heavily doped source region 172 beneath sidewall oxide 162 and nitride spacer 176 and the portion of lightly doped drain region 142 beneath sidewall oxide 164 and nitride spacer 178 are essentially unaffected. Ultra-heavily doped source region 186 is doped N++ with an arsenic concentration in the range of about 1.5×10 19 to 1×10 21 atoms/cm 3 , and heavily doped drain region 188 is doped N+ with an arsenic concentration in the range of about 1×10 19 to 1×10 20 atoms/cm 3 . Preferably, the dopant concentration of ultra-heavily doped source region 186 is at least 1.5 times that of heavily doped source region 172 and heavily doped drain region 188.
In FIG. 1O, photoresist 184 is stripped, and a rapid thermal anneal on the order of 900° to 1050° C. for 10 to 30 seconds is applied to remove crystalline damage and to drive-in and activate the implanted arsenic from the previous two ion implantations. As a result, heavily doped source region 172 and ultra-heavily doped source region 186 merge to form a source, and lightly doped drain region 142 and heavily doped drain region 188 merge to form a drain for an NMOS device controlled by polysilicon gate 120. Heavily doped source region 172 provides a first channel junction 190 that is substantially aligned with sidewall 122, and lightly doped drain region 142 provides a second channel junction 192 that is substantially aligned with sidewall 124. In addition, ultra-heavily doped source region 186 and heavily doped drain region 188 are spaced from channel junctions 190 and 192.
In FIG. 1P, photoresist 194 is deposited as a continuous layer over substrate 102 and selectively irradiated using the photolithographic system and the third reticle, and the irradiated portions are removed to provide an opening in photoresist 194. The opening is above active region 108, and photoresist 194 covers active region 106.
In FIG. 1Q, a portion of lightly doped source region 150 outside oxide sidewall 166 and nitride spacer 180 is converted into heavily doped source region 196, and a portion of lightly doped drain region 152 outside oxide sidewall 168 and nitride spacer 182 is converted into heavily doped drain region 198 by subjecting the structure to ion implantation of boron difluoride, indicated by arrows 200, at a dose in the range of 2×10 15 to 3×10 15 atoms/cm 2 and an energy in the range of 20 to 80 kiloelectron-volts. Polysilicon gate 130, sidewall oxides 166 and 168, nitride spacers 180 and 182, and photoresist 194 provide an implant mask for the underlying portion of substrate 102. As a result, heavily doped source region 196 is substantially aligned with nitride spacer 180 on the side opposite sidewall oxide 166, and heavily doped drain region 198 is substantially aligned with nitride spacer 182 on the side opposite sidewall oxide 168. Furthermore, the portion of lightly doped source region 150 beneath sidewall oxide 166 and nitride spacer 180 and the portion of lightly doped drain region 152 beneath sidewall oxide 168 and nitride spacer 182 are essentially unaffected. Heavily doped source region 196 is doped P+ with a boron concentration in the range of about 1×10 19 to 1×10 20 atoms/cm 3 , and heavily doped drain region 198 is doped P+ with a boron concentration in the range of about 1×10 19 to 1×10 20 atoms/cm 3 . Preferably, the dopant concentration of heavily doped source and drain regions 196 and 198 is at least 10 times that of lightly doped source and drain regions 150 and 152. At this point, the doping in active region 108 continues to be symmetrical.
In FIG. 1R, photoresist 194 is stripped, and nitride spacers 176, 178, 180 and 182 are removed by applying a dry etch that is highly selective of silicon nitride with respect to silicon dioxide. Accordingly, oxide layer 160 is substantially unaffected by the etch, and oxide layer 160 provides an etch mask for polysilicon gates 120 and 130 and substrate 102.
In FIG. 1S, photoresist 202 is deposited as a continuous layer over substrate 102 and selectively irradiated using the photolithographic system and a fifth reticle, and the irradiated portions are removed to provide an opening in photoresist 202. The opening is above heavily doped source region 196, lightly doped source region 150, sidewall oxide 166, and a first portion of polysilicon gate 130 adjacent to sidewall 132. Photoresist 202 covers lightly doped drain region 152, heavily doped drain region 198, sidewall oxide 168, a second portion of polysilicon gate 130 adjacent to sidewall 134, and active region 106.
In FIG. 1T, substantially all of the remaining lightly doped source region 150 is converted into heavily doped source region 204, and heavily doped source region 196 is converted into ultra-heavily doped source region 206 by subjecting the structure to ion implantation of boron difluoride, indicated by arrows 208, at a dose of 4.5×10 15 atoms/cm 2 and an energy in the range of 10 to 80 kiloelectron-volts. Photoresist 202 and sidewall oxide 166 and the first portion of polysilicon gate 130 (outside photoresist 202) provide an implant mask for the underlying portion of substrate 102. As a result, heavily doped source region 204 is substantially aligned with sidewall oxide 166 on the side opposite polysilicon gate 130, and lightly and heavily doped drain regions 152 and 198 are essentially unaffected. Heavily doped source region 204 is doped P+ with a boron concentration in the range of about 1×10 19 to 1×10 20 atoms/cm 3 , and ultra-heavily doped source region 206 is doped P++ with a boron concentration in the range of about 1.5×10 19 to 1×10 21 atoms/cm 3 . Preferably, the dopant concentration of ultra-heavily doped source region 206 is at least 1.5 times that of heavily doped source and drain regions 204 and 198. As is seen, a very small portion of lightly doped source region 150 remains beneath sidewall oxide 166 and polysilicon gate 130.
In FIG. 1U, photoresist 202 is stripped, and a rapid thermal anneal on the order of 900° to 1050° C. for 10 to 30 seconds is applied to remove crystalline damage and to drive-in and activate the implanted boron from the previous two ion implantations. As a result, heavily doped source region 204 diffuses into and essentially eliminates what remains of lightly doped source region 150. In addition, heavily doped source region 204 and ultra-heavily doped source region 206 merge to form a source, and lightly doped drain region 152 and heavily doped drain region 198 merge to form a drain for an PMOS device controlled by polysilicon gate 130. Heavily doped source region 204 provides a first channel junction 210 that is substantially aligned with sidewall 132, and lightly doped drain region 152 provides a second channel junction 212 that is substantially aligned with sidewall 134. In addition, ultra-heavily doped source region 206 and heavily doped drain region 188 are spaced from channel junctions 210 and 212.
Further processing steps in the fabrication of IGFETs typically include forming salicide contacts on the gates, sources and drains, forming a thick oxide layer over the active regions, forming contact windows in the oxide layer to expose the salicide contacts, forming interconnect metallization in the contact windows, and forming a passivation layer over the interconnect metallization. In addition, earlier or subsequent high-temperature process steps can be used to supplement or replace the desired anneal, activation, and drive-in functions. These further processing steps are conventional and need not be repeated herein. Likewise the principal processing steps disclosed herein may be combined with other steps apparent to those skilled in the art.
The present invention includes numerous variations to the embodiment described above. For instance, the gate insulators can remain outside the gates during the ion implantations. The sources may include very small lightly doped source regions adjacent to the channel junctions as long as the lightly doped source regions, if any, are far smaller than the lightly doped drain regions. The nitride spacers can be replaced by other materials, such as polysilicon, that can be selectively etched without removing the sidewall oxides. The spacers may include several layers of sequentially grown or deposited materials, of which only one layer need be subjected to the anisotropic etch. Alternatively, the sidewall insulators (e.g., sidewall oxide 162) can be omitted and the spacers can include a single layer of material such as silicon dioxide. The sidewall insulators can be formed at various stages between forming the gates and forming the insulative spacers (e.g., nitride spacer 176). For instance, the sidewall insulators can be formed before implanting any of the lightly doped regions, or the sidewall insulators can be formed after implanting the lightly doped regions and the first heavily doped source region (e.g., region 172). In these instances, implanting the first heavily doped source region converts the entire first lightly doped source region (e.g., region 140) into a heavily doped region. The gates can be various conductors, and the gate insulators can be various dielectrics. The device conductivities can be reversed. Suitable N-type dopants include arsenic, phosphorus and combinations thereof; suitable P-type dopants include boron, boron species (such as boron difluoride) and combinations thereof.
Further details regarding asymmetrical IGFETs are disclosed in U.S. application Ser. No. 08/711,383 unassigned, attorney docket no. M-4289! filed concurrently herewith, entitled "Asymmetrical Transistor With Lightly Doped Drain Region, Heavily Doped Source and Drain Regions, and Ultra-Heavily Doped Source Region" by Gardner et al.; U.S. application Ser. No. 08/711,382 unassigned, attorney docket no. M-4215! filed concurrently herewith, entitled "Asymmetrical Transistor With Lightly and Heavily Doped Drain Regions and Ultra-Heavily Doped Source Region" by Kadosh et al.; and U.S. application Ser. No. 08/711,957 unassigned, attorney docket no. M-4356! filed concurrently herewith, entitled "Asymmetrical N-Channel and Symmetrical P-Channel Devices" by Gardner et al.; the disclosures of which are incorporated herein by reference.
The invention is particularly well-suited for fabricating N-channel MOSFETs, P-channel MOSFETs, and other types of IGFETs, as well as CMOS structures such as inverter circuits, particularly for high-performance microprocessors where high circuit density is essential. Although only a single pair of N-channel and P-channel devices has been shown for purposes of illustration, it is understood that in actual practice, many devices are fabricated on a single semiconductor wafer as widely practiced in the art. Accordingly, the invention is well-suited for use in an integrated circuit chip, as well as an electronic system including a microprocessor, a memory and a system bus.
Those skilled in the art will readily implement the steps necessary to provide the structures and methods disclosed herein, and will understand that the process parameters, materials, and dimensions are given by way of example only and can be varied to achieve the desired structure as well as modifications which are within the scope of the invention. Variations and modifications of the embodiments disclosed herein may be made based on the description set forth herein, without departing from the scope and spirit of the invention as set forth in the following claims. | An asymmetrical N-channel IGFET and an asymmetrical P-channel IGFET are disclosed. One or both IGFETs include a lightly doped drain region, heavily doped source and drain regions, and an ultra-heavily doped source region. Preferably, the heavily doped source region and lightly doped drain region provide channel junctions. Forming a first asymmetrical IGFET includes forming a gate with first and second opposing sidewalls over a first active region, applying a first ion implantation to implant lightly doped source and drain regions into the first active region, applying a second ion implantation to convert substantially all of the lightly doped source region into a heavily doped source region without doping the lightly doped drain region, forming first and second spacers adjacent to the first and second sidewalls, respectively, and applying a third ion implantation to convert a portion of the heavily doped source region outside the first spacer into an ultra-heavily doped source region without doping a portion of the heavily doped source region beneath the first spacer, and to convert a portion of the lightly doped drain region outside the second spacer into a heavily doped drain region without doping a portion of the lightly doped drain region beneath the second spacer. A second asymmetrical IGFET is formed in a related manner. Advantageously, one or both IGFETs have low source-drain series resistance and reduce hot carrier effects. | 7 |
FIELD OF THE INVENTION
The present invention relates to optical communication networks and, more particularly, to time-domain wavelength interleaved networks.
BACKGROUND OF THE INVENTION
Optical communication systems increasingly employ wavelength division multiplexing (WDM) techniques to transmit multiple information signals on the same fiber, and differentiate each user sub-channel by modulating a unique wavelength of light. WDM techniques are being used to meet the increasing demands for improved speed and bandwidth in optical transmission applications. For each ordered pair (N i , N j ) of nodes in a wavelength division multiplexing network, one could assign a wavelength λ ij so that data sent from node N i to node N j is always sent on the λ ij wavelength along some path from node N i to node N j . Distinct wavelengths can be assigned to each such communicating pair of nodes, if there are a sufficient number of wavelengths available, or the same wavelength could be assigned to a number of such node pairs, provided that the paths used are disjoint. In general, however, the number of wavelengths needed is quadratic with the number of network nodes. The capacity of a wavelength, however, far exceeds the typical communication load between nodes. Thus, it would be advantageous if the capacity of a wavelength could be shared in some way.
I. Widjaja et al., “Light Core and Intelligent Edge for a Flexible, Thin-Layered and Cost-Effective Optical Transport Network,” IEEE Optical Communications, S30-36 (May, 3003) incorporated by reference herein, proposed a network architecture, referred to as Time-domain Wavelength Interleaved Networking (TWIN), that combines wavelength division multiplexing and time division multiplexing techniques. Generally, according to the TWIN architecture, each node N i is assigned a distinct wavelength λ i and all other nodes send signals to N i using λ 1 in a time-shared manner. Thus, the number of wavelengths required is equal to the number of nodes rather than quadratic in the number of nodes. Each node can then be assigned time-slot(s) in which the node is permitted to send data to node N i with the time-slots chosen so that no two nodes send signals to node N i in the same time slot. In addition, a node can transmit a signal to at most one node during a given time slot. Scheduling time-slots in this manner is often challenging. TWIN also requires nodes in the network to function essentially as routers where the wavelength of a signal determines the outbound link for the signal.
A need therefore exists for a system and method for time-domain wavelength interleaved networking that reduce the need for complex time-slot scheduling and reduce the routing complexity.
SUMMARY OF THE INVENTION
Generally, a system and method are disclosed for time-domain wavelength interleaved networking that reduce the need for complex time-slot scheduling and reduce the routing complexity. According to one aspect of the invention, substantially all communications in the time-domain wavelength interleaved network pass through a hub node. In addition, interior nodes in the time-domain wavelength interleaved network will forward substantially all communications received from the hub node that are destined for another node on all branches outward from the hub node.
According to another aspect of the invention, since substantially all communications pass through the hub node, the hub node can impose a timing reference. In this manner, the transmission and reception of a message can be synchronized such that a message sent in a time-slot k by a node N i will be received by a node N j in the time-slot k. Further, the hub node can recover from a link failure by shifting transmission times of all nodes that are separated from the hub node by the failed link.
A more complete understanding of the present invention, as well as further features and advantages of the present invention, will be obtained by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a conventional TWIN network;
FIG. 2 is a schematic block diagram of an exemplary interior node of the conventional TWIN network of FIG. 1 ;
FIG. 3 illustrates a time-domain wavelength interleaved network incorporating features of the present invention;
FIG. 4 is a schematic block diagram of an exemplary interior node of the time-domain wavelength interleaved network of FIG. 3 ; and
FIG. 5 illustrates an exemplary WDM-TDM ring network.
DETAILED DESCRIPTION
The present invention improves the TWIN architecture by reducing the need for complex time-slot scheduling and the routing complexity of most nodes. In particular, the architecture of the present invention requires less complex equipment at all interior nodes except one specially designated hub node (that will require the same equipment as an interior TWIN node).
Conventional TWIN Network
FIG. 1 illustrates a network 100 according to the conventional TWIN architecture. As shown in FIG. 1 , the network 100 is a connected graph of nodes 120 , 200 , where each edge N i N j in the graph represents the fact that there is a directed fiber from N i to N j and an oppositely directed fiber from N j to N i . Nodes 120 , 200 represent locations where signals can originate or terminate and where switching can be performed. The network 100 includes one or more leaf nodes 120 - 1 through 120 - 5 and one or more interior nodes 200 - 1 through 200 - 3 (hereinafter, collectively referred to as interior nodes 200 , discussed further below in conjunction with FIG. 2 ).
In general, for each node N i , a spanning tree T i of the network 100 can be defined so that for any other node N j , signals from N j to N i are sent along the path in TI from N j to N i . Each node N i is assigned a wavelength λ i on which the other nodes will send signals to N i . Thus, whenever a node 120 , 200 other than N i gets an incoming signal on λ i , the node 120 , 200 routes the signal along the outgoing fiber that leads to node N i in the tree T i . It is noted that for simplicity, some fixed spanning tree T can be chosen with T i =T for all N i .
At each node 120 , 200 , there is a tunable laser (not shown in FIG. 1 ), that can operate at any of the assigned wavelengths for any given period of time. Time is partitioned into equal length disjoint time-slots. Each node N i requires some number d ij of time-slots in which to send data to each other node N j . The demand from N i to N j is referred to as d ij . The demand is satisfied by a schedule S if during S, for every i and j, the laser at N i is scheduled to operate at wavelength λ j over d ij time-slots.
Scheduling the tunable lasers at each node 120 , 200 to satisfy these requirements has several constraints. Since the tunable laser at a node N i can operate at only one wavelength over a given time-slot, the schedule must not require any node N i to transmit to more than one receiving node during a particular time-slot. Also, if two signals of the same wavelength collide along the path towards a node then the two signals will interfere with one another and data will be lost. Thus, the schedule must guarantee that no two signals to a given node N i (i.e., signals on the same wavelength λ i ) meet along T i . It is easily seen, however, that two signals on the same wavelength λ i never meet along T i if and only if their arrival times at N i differ by at least the duration of a time-slot. A schedule consists of frames where the sub-schedule during each frame satisfies every demand. The same sub-schedule is assumed to be repeated in every frame. The goal of the scheduler is to find the shortest frame that allows all demands to be satisfied.
FIG. 2 is a schematic block diagram of an exemplary interior node 200 of the conventional TWIN network 100 of FIG. 1 . As shown in FIG. 2 , the exemplary interior node 200 includes a wavelength selective cross-connect 220 (assuming connectivity c>2) that passes a signal received on an incoming fiber from any direction to an outgoing fiber in any other direction, depending on the wavelength of the received signal. The wavelength selective cross-connect 220 includes a dropper 230 for each of c fibers, to drop its own wavelength from any incoming fiber. In addition, the interior node 200 includes a tunable laser 210 for each of c fibers, or one tunable laser 210 with a c-fold splitter, that can each operate at any of the assigned wavelengths for any given period of time.
Improved TWIN Network
FIG. 3 illustrates a time-domain wavelength interleaved network 300 incorporating features of the present invention. The time-domain wavelength interleaved network 300 is embodied using the above described principles of TWIN, as modified herein to provide the features and functions of the present invention. In particular, the time-domain wavelength interleaved network 300 operates on a two-fibered tree with a designated hub 350 or WDM-TDM ring 500 , discussed further below in conjunction with FIG. 5 , at its center. The network 300 includes one or more leaf nodes 320 - 1 through 320 - 5 , one or more interior nodes 400 - 1 through 400 - 2 , discussed further below in conjunction with FIG. 4 , and the designated hub 350 . As in the conventional TWIN network 100 of FIG. 1 , each node N i 320 , 350 , 400 in the time-domain wavelength interleaved network 300 of FIG. 3 is associated with a wavelength λ i and reads signals only on that wavelength λ i . Again, in each node, signals are sent by tunable lasers, discussed below in conjunction with FIG. 4 , in a rotating schedule of time-slots so that messages sent by two different nodes to the same receiving node do not interfere with one another.
In conventional tree networks, such as the network 100 of FIG. 1 , all messages are sent along a path in a tree between two nodes 120 , 200 . In the time-domain wavelength interleaved network 300 of the present invention, on the other hand, even messages between two nodes 320 , 400 on the same branch pass through the hub 350 . For example, as shown in FIG. 3 , messages from node 320 - 1 to node 400 - 1 , or from node 320 - 1 to node 320 - 2 , pass through the hub 350 . This would waste bandwidth in an ordinary optical network because the bandwidth on the link between nodes 400 - 1 and 350 could potentially have been used for other traffic. The present invention recognizes, however, that in TWIN networks, the wasted bandwidth is free. There can only be one message in a given time-slot on a given wavelength, otherwise there would be interference and the node receiving that wavelength would experience data loss.
As discussed further below, routing such messages through the hub 350 in accordance with the present invention increases effective bandwidth in the time-domain wavelength interleaved network 300 , by enabling optimal time-slot scheduling. Routing such messages through the hub 350 also increases latency in the messages between nodes on the same branch from the hub 350 , but for reasonable placements of the hub 350 , not beyond the latency experienced by messages between nodes on different branches.
A leaf node 320 (e.g., nodes 320 - 1 through 320 - 5 in FIG. 3 ) behaves as it would in the conventional network 100 , using its single tunable laser to send messages to desired recipients, and reading its own wavelength; nothing is passed through. According to one aspect of the present invention, discussed further below in conjunction with FIG. 4 , an interior node 400 (nodes 400 - 1 or 400 - 2 in FIG. 3 ) has connectivity greater than one, but does not send its messages in all directions. As discussed below in conjunction with FIG. 4 , all originating messages are directed by a single tunable laser toward the hub 350 . Similarly, messages in the designated wavelength of the interior node 400 are read only from the direction of the hub 350 . All traffic reaching the interior node 400 from the direction of the hub 350 is passed outward via a passive, wavelength-agnostic splitter 430 along each outgoing link other than the one towards the hub 350 . All traffic from other directions is passed toward the hub 350 via a passive, wavelength-agnostic coupler 420 . While passing all traffic reaching the node 400 from the direction of the hub 350 outward along each outgoing link results in more photons than necessary, there is no cost in effective bandwidth. Thus, the interior nodes 400 do not require any wavelength selective elements, other than to be able to drop the wavelength associated with the given node.
The hub 350 operates in a similar manner to an interior node 200 of the conventional TWIN network 100 . Generally, the hub 350 reads its own wavelength from any direction and forwards other wavelengths each in the proper direction. The only operating difference is that in some cases traffic incoming from a branch consisting of more than one node is sent back out via the outgoing fiber for the same branch.
According to a further aspect of the invention, the time-domain wavelength interleaved network 300 extends the scheduling and provisioning advantages of a star network to a general tree network. It is noted that the time-domain wavelength interleaved network 300 of the present invention and the conventional TWIN network 100 are similar when the tree happens to be a star, i.e., the tree has no interior nodes 200 , 400 .
FIG. 4 is a schematic block diagram of an exemplary interior node 400 of the time-domain wavelength interleaved network 300 of FIG. 3 . As shown in FIG. 4 , all originating messages are directed by a single tunable laser 410 toward the hub 350 . As previously indicated, messages in the designated wavelength of the interior node 400 are read only from the direction of the hub 350 by a single dropper 440 . All traffic from other directions is passed toward the hub 350 via a passive, wavelength-agnostic coupler 420 . The wavelength-agnostic coupler 420 passes all traffic received from the direction opposite the hub 350 (inward) toward the hub 350 . In addition, a passive, wavelength-agnostic splitter 430 passes all traffic reaching the interior node 400 from the same direction as the hub 350 outward along each outgoing link other than the one towards the hub 350 .
Thus, relative to the conventional interior node 200 of FIG. 2 , the interior node 400 of the present invention only needs one tunable laser 410 , directed toward the hub 350 . The interior node 400 drops its own wavelength only from the fiber coming from the hub 350 . For through traffic, the interior node 400 needs no cross-connect or wavelength selectivity. Traffic from the hub 350 is passed toward the leaf nodes 320 via a passive 1×(c−1) splitter 430 , and traffic toward the hub 350 is merged via a passive (c−1)×1 combiner 420 , where c is the connectivity of the node (i.e., the number of edges incident at the node).
It is noted that interior nodes of connectivity only two require no combiners 420 , splitters 430 or cross-connects in either the conventional TWIN network of FIG. 1 , or the network 300 of the present invention ( FIG. 3 ), but in the network 300 of the present invention, interior nodes of connectivity, c, only two need only drop and transmit in one direction instead of two.
Time-Slot Scheduling
According to another aspect of the invention, since all communications in the network 300 of the present invention pass through the hub 350 , the hub 350 can impose an absolute timing reference. Among other benefits, transmission in the time-domain wavelength interleaved network 300 can be synchronized to allow easy, maximum-efficiency time-slot scheduling, regardless of line lengths.
In the conventional TWIN network 100 , time-slots must be assigned (either off-line, in response to anticipated traffic demands, or on-line, in response to immediate needs) so that (1) no node is required to send traffic in overlapping time-slots, and (2) no wavelength is used in overlapping time-slots along any fiber.
If time-slot length is large compared to maximum delay, the off-line problem is easily solved using Konig's Theorem, and the on-line problem is handled nicely by simple heuristics. Suppose, for example, that traffic demand requires d ij time-slots for communication from node N i to node N j ; then d:=max(max i Σ j d ij ,max j Σ i d ij ) is the maximum number of time-slots required for transmission or reception by any node, and thus at least d time-slots are necessary in the rotating schedule. Konig's Theorem tells us, in the off-line case, that d time-slots are in fact sufficient. Even if every node demands all d time-slots for input and all d for output, a perfect schedule exists and is easily found. See, e.g., D. Konig, Graphok és alkalmazásuk a determinansok és a halmazok elméletére {Hungarian}, Mathematikai és Természettudományi Értesito 34, 104-119 (1916); or J. H. van Lint and R. M. Wilson, A Course in Combinatorics, Chapter 5, Thm 5.4, page 39, Cambridge U. Press (1992).
The ideal time-slot size (on the order of a few microseconds) for the conventional TWIN network 100 is comparable to speed-of-light delays even in a metropolitan network. Time-slots sent on a given wavelength at non-overlapping times may interfere when they arrive. Arrival time-slots (and, for maximum efficiency, departing time-slots as well) no longer occupy integral time points and even if they did, Konig's Theorem fails. The time-slot scheduling problem becomes immensely more complicated and could cost as much as a factor of three in bandwidth efficiency. It has been found that the loss of efficiency caused by transmission delay will be far less. The complexity of scheduling with delays may outweigh the actual loss of efficiency as a practical consideration.
The scheduling payoff for the time-domain wavelength interleaved network 300 of the present invention is that time-slot scheduling can be done as if there were no delays. The key is that transmission and reception can be synchronized by the hub 350 (as in a star network) so that a message sent in transmitting time-slot k from node N i to node N j always arrives precisely in receiving time-slot k. There may also be some additional advantage incurred by receiving in regular integer time-slots.
Let t i be the delay incurred by the traffic from node N i to the hub 350 , and π i be the delay (usually the same) for traffic from the hub 350 to node N i . Let s be the length of a time-slot. As in a conventional TWIN network 100 , transmissions are scheduled in frames, each frame consisting of a fixed number of time-slots. Assume that frames consist of w time-slots numbered 0 through w−1. Consider a transmission from node N i to node N j that has been assigned time-slot k. Then node N i transmits on wavelength λ j starting at times 0≦ks−t i +mw for mεZ 0 for a duration of s. Then, the hub 350 will start to receive this signal at times ks+mw for each such m. Also, node N j will receive this signal starting at times ks+mw+π j for relevant values of m and lasting for a duration of s. Then, two distinct time-slots of traffic to node N j are transmitted at non-overlapping times if they are sent from the same originating node, they occur at the hub at non-overlapping intervals of time and occur at the destination node N j over non-overlapping intervals of time. Thus, throughout the network 300 , distinct time-slots on a particular wavelength never interfere with one another.
In the case of symmetric delays, the nodes can synchronize transmissions since all the nodes need is to time the receipt of a message from the hub 350 containing its schedule (and the value w, if that has been changed). If delays are for some reason asymmetric, transmission times with node identities are sent toward the hub 350 and the hub 350 sends back the necessary corrections.
Signaling
According to another aspect of the invention, the positioning of the hub 350 in the time-domain wavelength interleaved network 300 allows the hub node 350 to do time-slot scheduling and general in-band signaling, as well as synchronization. For example, if the wavelength of the hub 350 is “black”, each other node will have a time-slot reserved in the black wavelength, and correspondingly the hub 350 will have a time-slot reserved on each of the wavelengths of the other nodes. These time-slots are used for signaling, synchronization, time-slot schedule distribution and other management traffic.
For example, in an off-line scheduling implementation, each node will report to the hub 350 , on its designated time-slot in the black wavelength, giving the number of time-slots the node needs for transmission to specified other nodes. The hub 350 solves the scheduling problem and passes the time-slot assignments back out to each node in the hub's time-slot on that node's designated wavelength.
For an on-line scheduling implementation, each node will report to the hub 350 when its buffer occupation suggests that the node needs more time-slots for transmission to some specified other node. The hub 350 can use heuristics to assign time-slot numbers on the fly to the requesting node. Conceivably, heavy signaling traffic and heavy ordinary traffic for the hub node 350 could force the hub to have separate wavelengths for the two functions.
Restoration
As in any tree network, if a link goes down, the network 300 is reduced to two connected components, and a fiber link (or sequence of links) must be enlisted to reconnect them. For the time-domain wavelength interleaved network 300 , each link (say, from node N i to node N j ) can be associated with a fiber path from N i to N j , some of whose links, but none of whose fiber, may already be in operation. The advantage of the time-domain wavelength interleaved network 300 in this scenario is that the assignment of time-slots to demand does not need to be redone; the only change necessary is a shift of transmission timing by nodes which were separated from the hub 350 by the downed link. If the old delay along the link N i N j was t ij and the delay of the replacement path is t′ ij , then each such node shifts its entire transmission schedule up in time by the amount t′ ij -t ij .
Extending the Ring Network
FIG. 5 shows a WDM-TDM ring 500 extended to a general unicyclic graph. The WDM-TDM ring 500 can be operated in the same manner as the time-domain wavelength interleaved network 300 of FIG. 3 , provided the ring 500 itself satisfies the conditions necessary for scheduling as if there were no delays.
Let t be the total delay around the ring 500 , s the time-slot length and w the number of time-slots in one frame of the schedule. If sw divides t, i.e., if t/sw is an integer, then a time-slot sent by any fixed node of the ring 500 comes back around to that node synchronized and in the same numbered position. Thus, assuming all (primary) traffic travels around the ring 500 in the same direction, the transmission times can be synchronized so that delays can be ignored in scheduling. If the ring is short, so that t is small compared with s, the same effect can be achieved by allowing a small gap between time-slots.
The remaining nodes of the network 500 synchronize as follows: if the path from node N i to the ring 500 hits the ring 500 at node N j , node N i schedules its transmissions exactly as if it were in a time-domain wavelength interleaved network 300 tree with node N j as its hub 350 . For schedule propagation and/or signaling, any of the nodes in the ring 500 can be designated to play the role described above for the hub 350 of a tree network.
Latency
In the time-domain wavelength interleaved network 300 of FIG. 3 , traffic between two nodes on the same branch of the hub 350 travels farther than it needs to. While this increases latency, the effect on maximum latency in the network will be small unless the tree is severely unbalanced. For example, in FIG. 3 , traffic from node A to node C travels four links (to nodes 350 , 400 - 1 and 400 - 2 again before reaching node 320 - 2 ) instead of two. However, traffic from node 320 - 1 to node 320 - 5 requires four links anyway.
Power
The splitters 430 and combiners 420 used in interior nodes 400 of the time-domain wavelength interleaved network 300 cause a loss in power, typically by a factor of c−1 for a node of connectivity c. Of course, this may apply also to the use of wavelength-selective cross-connects in conventional TWIN networks 100 . In either case, the loss must of course be taken into account, and in a complex network optical amplifiers may be necessary to compensate.
Hub Reliance
All traffic goes through the hub 350 , and the hub 350 optionally manages signaling and synchronization. Thus, if the hub 350 cannot operate, the time-domain wavelength interleaved network 300 is disabled. In practice, it may be desirable to duplicate equipment at the hub 350 , or to provision another node to take its place in an emergency.
It is to be understood that the embodiments and variations shown and described herein are merely illustrative of the principles of this invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention. | A system and method are disclosed for time-domain wavelength interleaved networking that reduce the need for complex time-slot scheduling and reduce the routing complexity. Substantially all communications in the time-domain wavelength interleaved network pass through a hub node. In addition, interior nodes in the time-domain wavelength interleaved network will forward substantially all communications received from the hub node that are destined for another node on all branches outward from the hub node. The central hub node can impose a timing reference. Thus, the transmission and reception of a message can be synchronized such that a message sent in a time-slot k by a node N i will be received by a node N j in the time-slot k. Further, the hub node can recover from a link failure by shifting transmission times of all nodes that are separated from the hub node by the failed link. | 7 |
FIELD OF THE INVENTION
The invention relates to an oil separator for an internal combustion engine. More particularly, the invention relates to an oil separator for removing oil from PCV gases of an internal combustion engine.
DESCRIPTION OF THE RELATED ART
An internal combustion engine typically includes a combustion chamber, where a fuel air mixture is burned to cause movement of a set of reciprocating pistons, and a crankcase, which contains the crankshaft driven by the pistons. During operation, it is normal for the engine to experience “blowby,” wherein combustion gases leak past the pistons from the combustion chamber and into the crankshaft. These combustion or blowby gases contain moisture, acids and other undesired by-products of the combustion process.
An engine typically includes a Positive Crankcase Ventilation (PCV) system for removing harmful gases from the engine and prevents those gases from being expelled into the atmosphere. The PCV system does this by using manifold vacuum to draw vapors from the crankcase into the intake manifold. Vapor is then carried with the fuel/air mixture into an intake manifold of the combustion chambers where it is burned. Generally, the flow or circulation within the system is controlled by the PCV valve, which acts as both a crankcase ventilation system and as a pollution control device.
It is normal for blowby gases to also include a very fine oil mist. The oil mist is carried by the PCV system to the manifold. The oil mist is then burned in the combustion chamber along with the fuel/air mixture. This results in an increase in oil consumption. A known method of removing oil from the blowby gases is to use a labyrinth or cyclone-type separator design. A path is provided through which small oil droplets pass. The small oil droplets impact the walls of the path and coalesce into larger droplets. The droplets are then re-introduced back to a sump, which generally holds excess oil in the system. Conventional cyclone separators, however, have a fixed radius and convergent nozzle and, as a result, require a high velocity to generate a sufficient centrifugal force to promote a formation of oil film from smaller droplets. Conventional cyclone separators are also known to generate a high pressure loss. Examples of cyclone separators are disclosed in U.S. Pat. Nos. 6,279,556 B1 and 6,626,163 B1 to Busen et al., both of which are assigned Walter Hengst GmbH & Co. KG.
Thus, it remains desirable to provide a cyclone oil separator that provides improved oil separation performance, lower pressure loss and greater system flexibility over conventional cyclone designs.
SUMMARY OF THE INVENTION
According to one aspect of the invention, an oil separator for removing oil from ventilation gases flowing between a crankcase and an intake manifold of an internal combustion engine. The oil separator includes a housing, a wall and a diaphragm. The housing has an inlet and an outlet. The wall is cooperative with the housing to define a path through which the gases flow between the inlet and the outlet. The wall is movably coupled to the housing to effect a change in the height of the path. The diaphragm has a movable portion coupled to the wall. The diaphragm defines a substantially closed volume. The substantially closed volume is continuous with the intake manifold so that pressure changes in the intake manifold causes corresponding displacement of the movable portion and the wall relative to the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
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 an exploded view of an oil separator according to one embodiment of the invention;
FIG. 2 is a cross sectional view of the oil separator in an closed position;
FIG. 3 is a cross sectional view of the oil separator in an open position;
FIG. 4 is an exploded view of an oil separator according to a second embodiment of the invention;
FIG. 5 is a cross sectional view of the oil separator of FIG. 4 shown in the closed position; and
FIG. 6 is a cross sectional view of the oil separator of FIG. 4 shown in the open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1–3 , an oil separator according to an embodiment of the invention is generally indicated at 10 . The separator 10 includes a housing 12 having first 14 and second 16 halves. Each half 14 , 16 of the housing 12 is generally cylindrical and cup shaped with a closed end 18 , 20 and an open end 22 , 24 . The first half 14 of the housing 12 has a smaller diameter than the second half 16 , so that the first half 14 can be arranged concentrically inside of the second half 16 . The first 14 and second 16 halves are arranged with the open ends 22 , 24 facing each other, such that a cavity 26 is defined between the closed ends 18 , 20 of the first 14 and second 16 halves of the housing 12 . The cavity 26 is substantially enclosed. By this arrangement, the first 14 and second 16 halves of the housing 12 can be axially displaced relative to each other in a telescopic manner. Further, the volume of the cavity 26 varies as the first 14 and second 16 halves of the housing 12 are displaced relative to each other. The housing 12 includes an outlet 30 formed in the closed end 18 of the first half 14 of the housing 12 .
A spiral shaped guide 40 extends outwardly from the closed end 18 of the first half 14 of the housing 12 toward the second half 16 . A spiral shaped wall 42 extends outwardly from the closed end 20 of the second half 16 toward the first half 14 . The housing 12 includes an inlet 32 formed in the spiral shaped wall 42 of the second half 16 . The guide 40 and wall 42 have corresponding shapes so as to divide the cavity 26 and define a continuous spiral shaped path that guides a flow of gases between the inlet 32 and the outlet 30 . The guide 40 and wall 42 are slidably engaged along an axis 44 . Optionally, a seal or gasket is provided between the guide 40 and wall 42 to prevent gases from leaking therebetween. The path has a width that decreases in size between the inlet 32 and the outlet 30 . Preferably, the width of the path between the inlet 32 and the outlet 30 decreases at a constant rate. The function of the spiral path in the removal of oil from the crankshaft gases flowing between the inlet and the outlet of the housing is discussed in greater detail in co-pending U.S. patent application Ser. No. 10/961,557 filed on Oct. 8, 2004, which is incorporated herein by reference in it entirety.
The path has a height that varies within a predetermined range that corresponds with sliding movement of the wall 42 relative to the guide 40 along the axis 44 . More specifically, sliding the guide 40 and wall 42 apart increases the height and volume of the path, thereby increasing the amount of gases that can flow therethrough under a fixed pressure. Sliding the guide 40 and wall 42 toward each other decreases the height and volume of the path, thereby increasing flow speed under a fixed pressure drop condition.
The oil separator 10 also includes a cap 50 and a flexible diaphragm 52 . The cap 50 and diaphragm 52 are each cup shaped with frustoconical walls. The cap 50 and diaphragm 52 are arranged in an inverted or opposed manner relative to each other to define a substantially closed volume or cavity 54 therebetween. The cap 50 is fixedly secured to the housing 12 by a rigid L-shaped bracket 55 . The diaphragm 52 includes a movable portion or end 56 coupled to the wall 42 . The diaphragm 52 is made from an elastomeric material so as to be deformable between an closed position, as shown in FIG. 2 , and an open position, as shown in FIG. 3 . Deformation of the diaphragm 52 between the closed and open positions causes substantially linear displacement of the end 56 of the diaphragm 52 along the axis 44 . Optionally, the diaphragm is provided in the form a plurality of rigid shells arranged concentrically for telescopic movement between the open and closed position. Optionally, the diaphragm is provided in the form of a cylinder/plunger arrangement, wherein the plunger is slidably supported within the cylinder for movement between the closed and open positions. Optionally, the cap is integrally formed with the diaphragm, such that the diaphragm defines the substantially closed cavity.
A biasing member 60 is continuously energized between the cap 50 and the diaphragm 52 to bias the end 56 of the diaphragm 52 toward the closed position. Preferably, the biasing member 60 is a helical coil spring. Optionally, a washer 57 is disposed between the end 56 of the diaphragm 52 and the biasing member 60 . The washer 57 includes a boss to keep the biasing member 60 centered on the end 56 of the diaphragm 52 .
A conduit 58 is coupled between the cap 50 and the intake manifold (not shown) so that the cavity 54 of the diaphragm 52 is open with an atmosphere defined by the intake manifold. The diaphragm 52 stays in the closed position while the pressure of the cavity 54 remains above a threshold amount. The threshold amount is related to the predetermined spring rate of the biasing member 60 . That is, it is possible for the pressure to be below ambient pressure, while the biasing member 60 maintains the end 56 of the diaphragm 52 in the closed position.
Typically, a vacuum is created in the intake manifold and cavity 54 due to decreased engine speed. The diaphragm 52 begins to deform and collapse toward the open position when the pressure in the cavity 54 falls below the threshold amount. The extent of the deformation of the diaphragm 52 and resulting displacement of the end 56 of the diaphragm 52 is proportional to the amount of change in the pressure below the threshold amount. Thus, low engine speeds will result in the formation of a large vacuum or pressure drop in the intake manifold and cavity 26 . In turn, the large pressure drop below the threshold amount causes a large displacement of the end 56 and wall 42 along the axis 44 away from the guide 40 . Displacement of the wall 42 away from the guide 40 increases the height of the path, thereby allowing decreased gas flow velocity between the inlet 32 and outlet 30 of the housing 12 . The increased capacity of the path between the inlet 32 and outlet 30 , therefore, accommodates the decreased demand from the PCV valve.
Increased engine speeds results in a pressure drop decrease between manifold and cavity 26 , which tends to expand the cavity 54 and displace the end 56 of the diaphragm 52 toward the closed position. It should be appreciated that pressure increase means positive change in the pressure, although the resulting pressure may still be below ambient, i.e. a vacuum may still exist in the cavity 54 . Displacement of the diaphragm 52 toward the closed position shortens the path between the inlet 32 and outlet 30 , as the wall 42 is moved toward the guide 40 . The shortened path allows increased gas flow velocity between the inlet 32 and outlet 30 of the housing 12 for improving oil droplet capturing function. The capacity of the path between the inlet 32 and outlet 30 , therefore, increases device efficiency in response to the decreased functionality of PCV valve.
Referring to FIGS. 4–6 , a second embodiment of the oil separator is generally indicated at 110 , wherein like components are referenced by numerals offset by 100 . The oil separator 110 includes an impact plate 70 , a guide plate 72 and a wall 74 . The impact plate 70 , guide plate 72 and wall 74 are each planar and substantially parallel to each other. The guide plate 72 is disposed between the impact plate 70 and the wall 74 . The guide plate 72 includes a plurality of holes 76 allowing gases to flow between the inlet 132 and outlet 130 of the housing 112 . Each of the plurality of holes 76 has a predetermined diameter, preferably ranging between 2 and 4 mm. The wall 74 is slidably coupled to the housing 112 and coupled to the end 156 of the diaphragm 152 for movement along a linear path between the closed position, as shown in FIG. 5 , and the open position, as shown in FIG. 6 .
In the closed position, the wall 74 prevents the flow of gases through all except at least one of the plurality of holes 76 , therefore to increase gas flow velocity to improve oil droplet capturing efficiency. Sliding the wall 74 to the open position reveals all of the plurality of holes 76 allowing increased gas flow through the guide plate 72 when enough flow rate is achieved to main consistent oil droplet capturing efficiency at different engine operating conditions. The plurality of holes 76 are arranged in rows normal to the linear path of the wall 74 , such that movement of the wall 74 toward the open position reveals successive rows of holes 76 . In either position, gases flow through the guide plate 72 and toward the impact plate 70 . A high velocity impact region is formed at the impact plate 70 as gases are redirected around the impact plate 70 and toward the outlet 130 . The high velocity impact region promotes coalescence due to impact and removal of oil from the gas flow.
The invention has been described in an illustrative manner. It is, therefore, to be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Thus, within the scope of the appended claims, the invention may be practiced other than as specifically described. | An oil separator that removes oil from ventilation gases flowing between a crankcase and an intake manifold of an internal combustion engine. The oil separator includes a housing, a wall and a diaphragm. The housing has an inlet and an outlet. The wall is cooperative with the housing to define a path through which the gases flow between the inlet and the outlet. The wall is movably coupled to the housing to effect a change in the height of the path. The diaphragm has a movable portion coupled to the wall. The diaphragm defines a substantially closed volume. The volume is open with the intake manifold so that pressure changes in the intake manifold causes corresponding displacement of the movable portion and the wall relative to the housing. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35 U.S.C. §119 of German Patent Application DE 10 2013 008 425.3 filed May 16, 2013, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention pertains to a method for recognizing sensor poisonings in portable gas-measuring devices by means of a test station as well as to a test station for carrying out this method.
BACKGROUND OF THE INVENTION
[0003] Portable gas-measuring devices are usually used by persons who are located in areas in which they may be exposed to harmful gases. Such gas-measuring devices may be equipped with different models of sensors, e.g., infrared sensors, semiconductor sensors, electrochemical sensors, catalytic sensors or the like. However, the phenomenon of the so-called sensor poisoning plays a major role in respect to the ability of the gas sensor and hence of the gas-measuring device to function especially in the case of catalytic sensors.
[0004] Such catalytic sensors typically recognize not only a special gas, but there are so-called cross sensitivities, i.e., the sensor recognizes a plurality of different gases simultaneously, without being able to concretely indicate which of these gases it is actually measuring. However, the sensitivity to these gases may be different. The sensitivity to the recognized gases decreases in the course of the aging of such sensors. However, the sensitivity does not decrease uniformly for all recognized gases. The process is rather affected by the concrete history of the individual gas sensor, i.e., by the ambient and storage conditions and the gas species and quantities of gases to which the sensor was already exposed in the course of its life. However, the sensor may be damaged or poisoned above all by certain substances. Among others, substances such as silicon, sulfur compounds and polymerizing substances lead to such a poisoning in case of catalytic EX sensors (sensors that are used in an environment with potential explosion hazard and/or can detect explosible/explosive gases). One speaks of sensor poisoning in this connection if a certain gas or vapor to be detected cannot be processed in the catalytic sensor any longer and thus it cannot be detected any longer, or when the sensitivity is insufficiently low to initiate the necessary actions, e.g., alarms. The sensor in this case indicates a measurement result that is much too low compared to the actually present concentration of the gas to be detected. It may in this case happen that a sensor, which can measure a plurality of different gases, continues to correctly indicate a first gas, but it does not any longer correctly measure a second gas, for which it is already poisoned. This is especially significant if the calibrating gas, i.e., the gas with which the sensor sensitivity is set, corresponds to the gas for which the normal sensitivity was maintained. The loss of sensitivity for the second gas can thus remain suppressed.
[0005] Such a sensor poisoning may become especially relevant, for example, in case of catalytic sensors that shall detect combustible gases, e.g., in the area of firefighting, but also in the petrochemical industry, chemical industry or in mining. Such catalytic sensors can also recognize, besides methane, for example, different other gases and vapors, e.g., propane, pentane, butane or nonane and toluene or the like. For example, sensors that are used in the area of firefighting and shall indicate the presence of combustible gases or vapors, are often set by means of toluene or nonane, because they have a comparatively low sensitivity to these vapors. It is in this case assumed that a sensor thus set will adequately detect the entire range of combustible gases and vapors. However, it may be problematic that the sensitivity of the sensor to toluene and nonane is often retained for a long time, while the sensitivity to, e.g., methane declines much sooner, which is also called selective sensor poisoning for methane (or another corresponding gas). The gas sensor in this case measures the quantity of all gases present as a so-called sum signal, i.e., as a sum of a plurality of signals. The sum is composed of the individual measured values of the gases present. It cannot be recognized on the basis of the sum how high the actual percentage of the particular gases measured is. At the same time, the gas sensor is typically also unable to resolve the sum signal into the individual components. Thus, there may be a risk that the actually present concentrations of individual combustible gases, especially methane, but also of another gas, for which the sensor is already poisoned, is estimated incorrectly at an operating site. This may lead to drastic consequences for the user of the gas-measuring device in the worst case.
[0006] For example, US 2008/0257732A1, US 2006/0019402A1, and U.S. Pat. No. 5,670,115 A describe in this connection that sensor poisonings are determined by means of various calibrating or test gases, and the gas sensor to be tested is exposed to the calibrating or test gases one after another.
[0007] Test stations for gas-measuring devices, in which different test gases can be admitted simultaneously to a plurality of gas-measuring devices, are known from the documents JP 2006-003 115 A, U.S. Pat. No. 7,530,255 B2, and WO 2013/019178 A1.
SUMMARY OF THE INVENTION
[0008] Based on this, an object of the invention is to provide a method and a test station for carrying out the method, with which method the risk of incorrect estimation of a present concentration of a gas can be reduced.
[0009] In a method for recognizing sensor poisonings in portable gas-measuring devices by means of a test station, wherein the test station has a main unit including a control and analysis unit and wherein the test station has a plurality of test modules, which are connected with the main unit for data exchange, and into which a gas-measuring device each can be inserted (connected), wherein the test station has means for recognizing the model of the device for detecting the model of the device and/or the model of the gas sensor of the particular gas-measuring device inserted into a test module, wherein the main unit has a plurality of gas inlets for different test gases and wherein the test station has a first gas feed line, through which test gas can be sent to the test modules, a second gas feed line, through which a purging gas can be sent to the test modules, and a gas drain line, through which gas can be sent from the test modules back to the main unit, the present invention makes provisions for the method to have the following steps:
a. Insertion of at least one gas-measuring device into at least one of the test modules of the test station; b. Recognition of the model of the gas sensor of the gas-measuring device inserted and/or of the model of the gas-measuring device inserted by the means for recognizing the device model of the test station; c. Transmission of the recognized gas sensor model and/or of the model of the device of the gas-measuring device inserted at the control and analysis unit; d. Selection of a first test gas suitable for the model of the gas sensor of the gas-measuring device inserted by the control and analysis unit; e. Connection of the gas inlet, through which the selected test gas can be fed, to the first gas feed line in the test station; f. Feeding of the first test gas to the test module, in which the gas-measuring device is inserted; g. Detection of a first measured value by the gas sensor; h. Optionally: Purging of the gas-measuring device and of the gas sensor by means of a purging gas, which is sent through the second gas feed line from the main unit to the test module, in which the gas-measuring device is inserted; i. Selection of a second test gas suitable for the model of the gas sensor of the gas-measuring device inserted by the control and analysis unit; j. Connection of the gas inlet, through which the selected second test gas can be fed, to the first gas feed line in the test station; k. Feeding of the second test gas to the test module, in which the gas-measuring device is inserted; l. Detection of a second measured value by the gas sensor; and m. Determination whether a sensor poisoning is present on the basis of the first measured value detected and the second measured value detected.
[0023] A first gas feed line, through which test gas can be sent to the test modules, will also be called test gas feed line (test gas line) below. The second gas feed line, through which purging gas can be sent to the test modules, will also be called purging gas line (purging gas feed line).
[0024] Whether a sensor poisoning possibly occurs can be determined rapidly and in a simple manner based on the first and second measured values by means of the test station with such a method. For example, information on the measured value, that is ideally expected (expected measured value) for the particular model of gas sensor (sensor model) for a certain gas at a preset concentration of the gas in a gas mixture, can be stored for this in the control and analysis unit.
[0025] The analysis can then be based on the knowledge of the cross sensitivities of the two gases to one another. For example, the indicated measured value of the two gases is put into relationship with one another. If the value is below a limit, which can be considered to be sufficiently safe from the viewpoint of the protection of persons, it is meaningful to classify the sensor as being poisoned. For example, a value for the lower explosion limit (LEL) of a gas in a gas mixture may be stored for this. It may also be provided that a value that is markedly lower than the lower explosion limit, e.g., 50% of the lower explosion limit (50% LEL), is stored to ensure that the presence of corresponding combustible gases is detected in time in all cases.
[0026] Catalytic sensors, which detect a plurality of different such gases due to corresponding cross sensitivities, are typically not uniformly sensitive for all these gases. There are, for example, sensors that indicate, when exposed to a gas that contains methane at a concentration corresponding to 50% LEL, that methane is contained at a concentration of 50% LEL. However, when exposed to propane at a concentration of 50% LEL, the same sensor indicates only that propane is present at a concentration of 29% LEL. Such an exemplary sensor would therefore be expected, when exposed to a corresponding gas, to indicate 50% LEL for methane corresponding to 50% LEL and to indicate 29% LEL for propane. The expected measured value would be correspondingly 50% LEL for methane and 29% LEL for propane. Such values are usually known for the respective models of sensors and can therefore be correspondingly stored in the control and analysis unit.
[0027] In a very simple embodiment, it is possible, for example, for catalytic sensors, which are used as a primary measure in the protection against personal injuries due to explosions, to check whether after adjusting to the first, more insensitive gas, the second, more sensitive gas reaches at least the concentration that was fed. Thus, even though the ratio would drop to 1:1, but triggering an alarm in due time would still always be guaranteed.
[0028] To recognize selective poisonings in time, it is, however, recommended that a sensor-specific value be determined, which must not be undershot. This value can be determined experimentally. It is consequently advantageous if the test station with which the method is carried out is a test station in which measured values expected in the control and analysis unit are stored for a plurality of gas sensor models and/or for gases that are to be measured. What measured values are stored in the individual gas sensor models depends logically on the particular gas sensor model.
[0029] It may also be provided in this connection that information is stored in the control and analysis unit for individual models of gas sensors on which gas mixture can be used as the first test gas, which gas mixture as the second test gas, what measured value is expected in case of exposure to the first test gas and what measured value is expected on exposure to the second test gas. It may also be provided, as an alternative, that information is stored on which gas mixture can be used as the first test gas, which gas mixture can be used as the second test gas and on the ratio of the first measured value that is expected on exposure to the first test gas to the second measured value that is expected on exposure to the second test gas.
[0030] To determine whether a gas-measuring device or a gas sensor, which is used in a gas-measuring device, is still sufficiently in good working order to recognize a hazardous situation in time and reliably, the following procedure can then be followed by means of the method according to the present invention.
[0031] The gas-measuring device to be tested, i.e., the gas-measuring device in which a gas sensor to be tested is installed, is inserted into a test module corresponding to the steps a. through c. of the method according to the present invention. The test station in this case recognizes the gas-measuring device model that was inserted or what gas sensor model or, if a plurality of gas sensors are installed in the gas-measuring device, the gas sensor models the gas-measuring device inserted contains. The test station can preferably recognize both, i.e., the test station recognizes the model of gas-measuring device that was inserted and the model of gas sensor or the models of gas sensors that are installed in the gas-measuring device. This is advantageously carried out by means of the device model recognition means. Each test module advantageously has such a device model recognition means. The test module then transmits the recognized information via corresponding data exchange means, by which the test module is connected with the main unit for data exchange, to the control and analysis unit of the main unit.
[0032] Based, as was described above, on data stored in the control and analysis unit of the main unit, the control and analysis unit of the test station then selects, corresponding to step d. of the method according to the present invention, a first test gas, with which it can be determined, in principle, whether the gas sensor of the gas-measuring device, which said gas sensor is to be tested, is in good working order. A test gas is a gas mixture that contains one or more gases of a known composition. A gas mixture is defined, in principle, as a gas that contains one or more different gases with a known or unknown composition. If it shall be checked, for example, whether a catalytic sensor detects combustible gases correctly, the first test gas may be, for example, a gas mixture that contains combustible gases with a known composition.
[0033] The test station with which the method is carried out has a plurality of gas inlets, to which, for example, a pressurized gas cylinder each, which contains a certain test gas, can be connected. This is especially advantageous if the selection of test gases shall be able to be chosen individually. Individual pressurized gas cylinders can be replaced rapidly and simply in this case, as a result of which different test gases can correspondingly be made available, depending on the individual requirements of the operator of the test station. However, it may also be provided that stationary gas feed lines for such test gases are connected to the gas inlets. The control and analysis unit of the main unit of the test station in this case has corresponding information on what test is connected to which gas inlet. This can be recognized either by the control and analysis unit by means of a recognition device, or it is programmed correspondingly in the control and analysis unit by the operator of the test station. Corresponding connection data may, of course, also be preset and stored in the control and analysis unit. After the control and analysis unit of the test station has selected the suitable first test gas, it gives a prompt for the gas inlet through which the selected test gas can be fed to become connected, corresponding to step e. of the method according to the present invention, to become connected with the first gas feed line of the test station. This can take place, for example, by sending a corresponding control command to one or more valves in the test station.
[0034] If the corresponding gas port of the main unit is connected with the first gas feed line (connected to the first gas feed line), the test station can send, corresponding to step f. of the method according to the present invention, the first test gas to the test module, into which the gas-measuring device to be tested is inserted. The gas-measuring device will then measure the first test gas fed to it in just the same way as it would measure any other gas mixture during use in a real situation, and it sends a first measured value. Adjustment may optionally also be made to the first measured gas in this step, i.e., the first measured value is corrected such that it corresponds to the concentration in the test gas cylinder. This first measured value is detected by the test module and preferably transmitted by means of the data exchange means to the main unit, namely, to the control and analysis unit of the test station. A first measured value of the gas sensor is thus detected corresponding to step g. of the method according to the present invention. If the gas-measuring device to be tested contains a plurality of gas sensors, it is conceivable that steps d. through g. are carried out separately for each of these gas sensors.
[0035] To remove residues of the first test gas from the gas-measuring device to be tested following this first measurement and to thus prevent the subsequent second measurement from being possibly distorted, it may be useful to purge the gas-measuring device with a purging gas in a next step. The method according to the present invention therefore provides for the purging of the gas-measuring device inserted and of the gas sensor as an optional step h. by means of a purging gas, which is sent through the second gas feed line from the test station to the test module, into which the gas-measuring device is inserted. A purging gas is typically a neutral (inert) gas, in which the gas sensor does not detect any gases that are to be detected. This may be, for example, normal air. Depending on the environment in which the test station is used, this air may be fed through a pressurized cylinder, or it may also be taken up from the ambient air, for example, by means of a pump. The test station advantageously has a gas port for this in its main unit, which port can be connected either with a corresponding purging gas cylinder or with the ambient air. This gas port is preferably connected with the second gas feed line of the test station. The purging gas can be sent through this second gas feed line to the test modules, and the control and analysis unit of the test station can transmit the command for switching over from the first gas feed line to the second gas feed line to the test modules. The transmission preferably takes place via data exchange means. It may also be provided, as an alternative, that each test module has a control unit (test module control unit) of its own. This test module control unit can then control a switchover from the first gas feed line to the second gas feed line, which switchover is independent from the main unit.
[0036] Regardless of whether step h. is performed after detection of the first measured value or not, a second measured value is detected corresponding to the method according to the present invention by carrying out steps i. through l., in order to be finally able to determine, in step m., whether a sensor poisoning is possibly present. Steps i. through l. are carried out as was already described above for steps d. through g., step i. being carried out analogously to step d, step j. analogously to step e., step k. analogously to step f., and step l. analogously to step g. It is recognized that it is also readily possible in an alternative order in which the method is carried out to carry out step i. (selection of a second test gas suitable for the model of the gas sensor) already immediately after step d. and hence before step e.
[0037] To determine, corresponding to step m., whether sensor poisoning is present, the first measured value, which was detected in step g., and the second measured value, which was detected in step l., are compared with the respective expected measured values. The comparison may be carried out automatically by the control and analysis unit. However, it may also be provided that the control and analysis unit only passes on the actual measured values and the corresponding expected measured values to an output unit and an operator of the test station decides on the basis of this information whether or not sensor poisoning is present. It may also be provided, for example, that the operator receives the expected and actual measured values displayed on a display device (display), that the expected and actual measured values are outputted via a printing device, or even that these are transmitted to another terminal, e.g., a computer of the operator, and are analyzed there by the operator. However, the control and analysis unit preferably performs the comparison automatically and outputs only the result, namely, the determination of whether or not sensor poisoning is possibly present. It is even conceivable, in an especially preferred manner, that the control and analysis unit outputs the result in the form of a control command, which it selects on the basis of the result. Various scenarios are conceivable, e.g., the following: If the control and analysis unit arrives at the result that a sensor poisoning is possibly present, this control command may be, for example, that the corresponding gas-measuring device is blocked from further use. It may also be provided that the control command is the sending of a warning signal, the blocking of the removal of the gas-measuring device from the test module or something similar.
[0038] In any case, the result is determined by comparison of the first measured value with the second measured value. For example, the ratio of the first measured value to the second measured value can be formed. If the two measured values essentially correspond to the expected measured values or they deviate from the expected measured values by a constant error, which is generated by an incorrect setting of the sensor only, the ratio of the two measured values corresponds to the ratio of the expected measured values. If, however, there is sensor poisoning, the error with which the first measured value deviates from the expected first measured value from the error with which the second measured value deviates from the expected second measured value. As a consequence, the ratio of the first measured value to the second measured value also deviates significantly from the ratio of the expected first measured value to the expected second measured value. The limits within which a deviation of the ratio of the real measured values from the ratio of the expected measured values are considered to be a significant deviation may be stored preferably for each gas-measuring device to be tested or for each model of gas sensor to be tested in the control and analysis unit. It may also be provided that these limits are set and programmed by the operator when the test station is put into operation or during the operation of the test station.
[0039] It may also be provided that in case of a non-automatic analysis, in which the values are only displayed, for example, to the operator, the measured values or the ratios of the measured values are checked only by the operator comparing them, for example, with values present in tables or in another form or by a similar procedure. As an alternative to the comparison of the measured value ratios formed as described above, it may also be provided in such a case that a direct comparison of the measured values with the expected values is performed. For example, the operator can determine in this case for each measured value how great the error is by which the real measured value deviates from the expected measured value and then compare the errors with one another. If the two measured values deviate from the expected values by an equal error or an error that is similar within narrow limits, sensor poisoning is very likely to be absent and there is only an incorrect adjustment of the sensor by this more or less constant error. However, if the errors deviate markedly from one another, there is a possibility that a sensor poisoning is present. It is obvious that this procedure can also be carried out automatically by the control and analysis unit of the test station.
[0040] It is thus favorable in any case if the determination of whether a sensor poisoning is present in step m. comprises the following steps:
m.1 Transmission of the first measured value and of the second measured value to the control and analysis unit of the test station; m.2 Determination of the ratio of the first measured value to the second measured value; and m.3 Outputting of the ratio by means of an output unit and/or selection of a follow-up action by the control and analysis unit of the test station on the basis of the ratio determined.
[0044] Step m.2 may also be, as an alternative, a determination of the ratio of the errors by which the real first measured value, i.e., the first measured value detected in step g., deviates from the expected first measured value and by which the real second measured value, i.e., the second measured value detected in step l., deviates from the expected second measured value, as was explained above.
[0045] If only the ratio is outputted in step m.3 without a further follow-up action being selected by the test station, the operator can select an individual subsequent reaction on the basis of this outputted information.
[0046] The selection of a follow-up action by the control and analysis unit is advantageously performed by a comparison of the ratio determined in step m.3 with a ratio being stored in the control and analysis unit. The control and analysis unit in this case determines by how much the determined ratio deviates from the stored ratio and selects a follow-up action in the form of a control command on the basis of the result obtained in this case for the deviation. If no ratios are being stored in the control and analysis unit, but only individual expected measured values, the control and analysis unit may also form first the ratio of the expected measured value for selecting the follow-up action and subsequently compare this ratio with the ratio of the real measured values detected in steps g. and l.
[0047] It is recognized that it is always advantageous if the first test gas contains a gas that is to be measured during the operation of the gas-measuring device at a first, known concentration and if the second test gas contains the gas to be measured at a second, known concentration, which is different from the concentration of the gas in the first test gas. It may also be advantageous in this case if the second test gas contains, in addition to the gas to be measured, at least one gas for which the gas sensor model present in the gas-measuring device inserted has cross sensitivity. It is especially favorable in this connection, if the gas for which there is cross sensitivity is not a component of the first test gas. The first and/or second test gas may be selected especially preferably from the group containing propane, propane mixed with H 2 S, CO, O 2 and/or CO 2 , pentane, pentane mixed with H 2 S, CO, O 2 and/or CO 2 , butane, hydrogen as well as mixtures of these gases and gas mixtures mentioned. Further gaseous or vapor components may also be added, e.g., toluene, nonane, methane, propane, butane, hydrogen, pentane or even mixtures thereof.
[0048] In a method according to the present invention, in which the test station is advantageously designed such that each test module has a gas feed line, which can be connected with a gas inlet of the gas-measuring device to be tested, which said line has a first feed valve and a second feed valve and which can be connected with the first gas feed line via the first feed valve and with the second gas feed line via the second feed valve, the present invention preferably makes, in addition, provisions for the feeding of the first test gas to the test module in step f. and for the feeding of the second test gas to the test module in step k. to contain the following respective steps:
[0000]
f.1 and k.1
Closing of the second feed valve;
f.2 and k.2
Opening of the first feed valve.
[0049] As was already described above, the first gas feed line is the test gas feed line and the second gas feed line is the purging gas feed line here as well. The gas inlet of the gas-measuring device to be tested is the gas inlet via which the gas-measuring device draws in the gas to be measured during intended use.
[0050] It may also be provided in any case that a plurality of gas-measuring devices can be inserted simultaneously into the test station. The gas-measuring devices may also be inserted at different times into the test station. The respective test module, in which a gas-measuring device is inserted at any desired time, then transmits, independently from the other test modules of the test station, the information to the main unit that a gas-measuring device was inserted and which gas sensor model or which gas sensor models and/or which device model was recognized. The control and analysis unit can then select the corresponding first test gas, likewise independently from the state of the other test modules.
[0051] Furthermore, steps h. and i. as well as m. of the method according to the present invention can be carried out for each test module, into which a gas-measuring device was inserted, independently from the state of the remaining test modules. In other words, the control and analysis unit can determine, for example, for a certain test gas, which can be fed via one of the gas inlets to the first gas feed line of the test station, for which test modules this test gas is needed either as a first test gas or as a second test gas.
[0052] By contrast, steps e. through g. and steps j. through l. are preferably carried out synchronously for all test modules of the test station. Steps e. and j. and steps f. and k. as well as steps g. and i. can be carried out simultaneously for different test modules that are fundamentally different from one another. However, it is useful if each test module performs all steps a. through m. at least once for each gas-measuring device that is inserted into the test module.
[0053] The following would be, for example, a conceivable course of such a method: By performing steps a. through d. or by performing step i. for all test modules independent from one another, the control and analysis unit determines, as was described above, which test gas the individual test modules need in the respective next step, i.e., step e. or step j. The control and analysis unit then determines which of these needed test gases shall be sent as the next gas through the first gas feed line of the test station. The feed of the test gas from the first gas feed line is then interrupted, preferably for all test modules that do not need this test gas, by closing the feed valve that is arranged between the test gas feed line and the respective test module. As a consequence, only the test modules that need the same test gas in the next step are connected with the first gas feed line fluidically. Corresponding to steps e. and j., respectively, the gas inlet, through which the selected test gas can be fed, is then connected as the next step to the first gas feed line in the test station and the test gas is sent to the test modules as described above corresponding to steps f. and k., respectively. Finally, a measured value is determined according to steps g. and l., respectively, for each test module, consequently for each gas-measuring device to which the test gas was admitted in the preceding step. It is then determined again for all test modules, independently from one another, whether the gas-measuring device in question has already run through all steps a. through l. and whether it is thus possible to carry out step m. for the test module in question or the gas-measuring device inserted. It is possible to perform step m. when both a first measured value and a second measured value were detected for the test module in question or the gas-measuring device inserted into the test module in question. Step m. is carried out for the test modules for which it is possible to carry out this step. The corresponding, still missing measured value is detected corresponding to the above-described method for the test modules for which it is not possible to carry out step m.
[0054] It is consequently recognized that in case a plurality of gas-measuring devices are or will be inserted into the test station, it is advantageous if the method has the following steps:
A Carrying out of steps a. through d. and/or carrying out of step i. for each of the gas-measuring devices independently from one another; B Determination by means of the control and analysis unit which of the test modules are equipped with gas-measuring devices and which of these gas-measuring devices need the same test gas as the next test gas; C Closing of the feed valve that is arranged between the test gas feed line and the respective test module for all test modules that do not need the test gas selected in B in the next step; and D Carrying out steps e. through h. or steps j. through m. for each of the gas-measuring devices determined in B independently from one another;
wherein each of the steps a. through m. is carried out at least once for each gas-measuring device that is inserted into a test module of the test station. However, it is also useful if steps a. through m. are carried out for each test module into which a gas-measuring device is inserted in the above-described order from a. to m. However, it may also be provided that the steps are carried out in the order a., b., c., d. i., e., f., g., h., j., k., l., m. or in the order a., b., c., d., i., j., k., l., h., e., f., g., m., and step h. is an optional step, which may be carried out in any case, as before, at any other desired point and/or at a plurality of points of the method.
[0059] On the whole, the course of the method for a gas-measuring device that is inserted into a test module when other gas-measuring devices are already present in the test station for testing is in this case, for example, as follows:
Insertion of the gas-measuring device into one of the test modules corresponding to step a. The gas-measuring device is preferably inserted when the feed valve that is arranged between the first feed line and the respective test module is closed, Recognition of the model of the device and/or of the gas sensor corresponding to step b., Transmission of the recognized model of the device and/or of the model of the gas sensor corresponding to step c.,
[0063] Selection of the first test gas by the control and analysis unit corresponding to step d. and/or selection of the second test gas by the control and analysis unit corresponding to step i.,
Waiting until one of the two test gases selected previously is the test gas that shall be sent next through the first gas feed line, Connection of the gas inlet, through which the selected test gas can be fed, to the first gas feed line in the test station, feeding of the test gas to the test module and detection of a first measured value, Determination that step m. cannot yet be carried out because two measured values have not yet been determined, Selection of the second test gas unless this was done already before, Waiting until the second of the two test gases selected previously is the test gas that shall be sent as the next gas through the first gas feed line, Connection of the gas inlet through which the selected test gas can be fed to the first gas feed line in the test station, feeding of the test gas to the test module and detection of a first measured value, and Determination that step m. can be carried out and carrying out of step m.
[0071] Further variants of this course are, of course, conceivable as well. For example, it is conceivable that a gas-measuring device is inserted into a test module, which contains a plurality of gas sensors, for which the above-described method is carried out independently from one another. It is advantageous, for example, in this case if both the model of the device and the model or models of the gas sensor/gas sensors of the device are recognized in step b. of the method.
[0072] Moreover, it is conceivable that so-called filter breakthroughs can be detected by means of the method according to the present invention. For example, filters that are selectively permeable for certain gases only can be used if a sensor arranged downstream of the filter shall not measure corresponding gases for which the filter is not permeable. This may be especially useful if the sensor has a cross sensitivity, namely, for a first gas, which shall be detected with the sensor, on the one hand, and, on the other hand, for a second gas, which can be captured (blocked/filtered) by means of the filter and which shall not be detected with the sensor. If, however, the filter is no longer in good working order and becomes permeable for the second gas, which is actually to be captured, one speaks of a filter breakthrough. The second gas, which is in this case flowing unrecognized through the filter, can distort the measured value that is outputted by the sensor. However, such a filter breakthrough is also recognizable by means of the method according to the present invention if the first test gas and the second test gas are selected correspondingly.
[0073] In a test station for carrying out the above-described method according to the present invention, the present invention makes provisions for the test station to have a main unit including a control and analysis unit, wherein the test station has a plurality of test modules, which are connected with the main unit for data exchange and into which a gas-measuring device each can be inserted, and the test station has means for recognizing the model of the device in order to detect the model of the device and/or the model of the gas sensor of the respective gas-measuring device inserted into a test module, and the main unit has a plurality of gas inlets for different test gases, and the test station has a first gas feed line, through which test gas can be sent to the test modules, a second gas feed line, through which a purging gas can be sent to the test modules, and a gas drain line, through which gas can be sent back from the test modules to the main unit, and the control and analysis unit is set up to carry out and/or control steps d. through m. of the above-described method according to the present invention.
[0074] It is advantageous in this case if the control and analysis unit is set up to carry out and/or control steps B and C corresponding to the above-described method. Furthermore, it is advantageous if the gas feed line of each test module can be connected fluidically with the gas inlet of a gas-measuring device to be tested when the gas-measuring device is inserted into the test module. It is also useful if each test module has a gas drain line, which can be connected with the gas drain line of the test station. The gas feed line of at least one test module preferably has a first feed valve and a second feed valve, and this gas feed line can be connected with the first gas feed line via the first feed valve and with the second gas feed line via the second feed valve.
[0075] Further features, details and advantages of the present invention appear from the text of the claims as well as from the following description of exemplary embodiments and from the figures. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] FIG. 1 is a schematic view of a test station for carrying out the method according to the present invention;
[0077] FIG. 2 a is a schematic view showing a state during the course of the method for a gas-measuring device inserted into the test station;
[0078] FIG. 2 b is a schematic view showing another state during the course of the method for a gas-measuring device inserted into the test station;
[0079] FIG. 2 c is a schematic view showing another state during the course of the method for a gas-measuring device inserted into the test station;
[0080] FIG. 2 d is a schematic view showing another state during the course of the method for a gas-measuring device inserted into the test station;
[0081] FIG. 2 e is a schematic view showing another state during the course of the method for a gas-measuring device inserted into the test station;
[0082] FIG. 2 f is a schematic view showing another state during the course of the method for a gas-measuring device inserted into the test station;
[0083] FIG. 3 a is a detail showing a state during the course of the method in case of a plurality of gas-measuring devices inserted independently from one another into the test station;
[0084] FIG. 3 b is a detail showing another state during the course of the method in case of a plurality of gas-measuring devices inserted independently from one another into the test station; and
[0085] FIG. 3 c is a detail showing another state during the course of the method in case of a plurality of gas-measuring devices inserted independently from one another into the test station.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0086] Referring to the drawings in particular, a test station 10 , which has a main unit 20 and a plurality of test modules 30 , is recognized in FIG. 1 . The number of test modules 30 is variable. A control and analysis unit 21 is arranged in the main unit 20 . The control and analysis unit 21 is connected with an output unit 27 and with a port 26 via data exchange means 28 . The output unit 27 is likewise arranged in the main unit 20 . However, according to an alternative embodiment, the output unit 27 is a component separate from the main unit 20 . The port 26 can be connected with a plurality of gas inlets 22 arranged in the main unit 20 . A test gas P 1 , P 2 , P 3 can flow through each of the gas inlets 22 , and a separate gas inlet 22 is preferably provided for each test gas P 1 , P 2 , P 3 . The number of gas inlets 22 is variable, and the three gas inlets 22 shown in FIG. 1 are merely exemplary. More or fewer gas inlets 22 may also be present in alternative embodiments.
[0087] Port 26 is connected with a first gas feed line 23 , through which the test gas P 1 , P 2 , P 3 can flow from the main unit 20 to the test modules 30 .
[0088] A furthermore, a port for a purging gas S, which is connected with a second gas feed line 24 and through which purging gas S can flow to the test modules 30 , is formed in the main unit 20 . In addition, an outlet is formed in the main unit 20 for gas A flowing back from the test modules 30 , which outlet is connected with a gas drain line 25 , through which gas A can flow back from the test modules 30 to the main unit 20 .
[0089] The test modules 30 have a mount 32 each for a gas-measuring device 40 . A gas-measuring device 40 typically has a gas inlet 41 and a gas outlet 42 . Furthermore, each of the test modules 30 has a device model recognition means 50 . Furthermore, the test modules 30 are each connected with the main unit 20 , especially with the control and analysis unit 21 , via data exchange means 31 .
[0090] It is recognized that the test modules 30 have a gas feed line 33 and a gas drain line 36 each. The gas feed line 33 is connected with the mount 32 such that the gas feed line 33 can be connected fluidically with the gas inlet 41 of a gas-measuring device 40 inserted into the mount 32 . The gas drain line 36 is connected with the mount 32 such that the gas drain line 36 can be connected fluidically with the gas outlet 42 of a gas-measuring device 40 inserted into the mount 32 .
[0091] The gas feed line 33 has a first feed valve 34 . The first feed valve 34 can be connected with the first gas feed line 23 . The gas feed line 33 has, in addition, a second feed valve 35 . The second feed valve 35 can be connected with the second gas feed line 24 . The open or closed state of the first feed valve 34 and the second second feed valve 35 are controlled via the control and analysis unit 21 via connections from valve actuators to the control and analysis unit 21 . The gas feed line 36 can be connected with the gas drain line 25 via a port 37 .
[0092] A test station 10 can be recognized in FIG. 2 a before a gas-measuring device to be tested was inserted into one of the test modules 30 . The first feed valves 34 connected with the first gas feed line 23 are closed. The feed valves 35 connected with the second gas feed line 24 are opened. Purging gas S can thus flow through the test modules 30 . The port 26 is in a random port position; it is connected here with the gas inlet 22 , through which the test gas P 1 can be fed.
[0093] Corresponding to step a., a gas-measuring device 40 is inserted in FIG. 2 b into one of the test modules 30 . The gas inlet 41 of the gas-measuring device 40 is connected with the gas feed line 33 , and the gas outlet 42 is connected with the gas drain line 36 . According to step b., the device model recognition means 50 recognizes the device model of the gas-measuring device 40 , and it optionally even recognizes the gas sensor that is installed in the gas-measuring device 40 . The device model recognition means 50 transmits, corresponding to step c., the recognized information, i.e., the recognized model of the gas sensor and/or the recognized device model, to the control and analysis unit 21 . This is carried out by means of the data exchange means 31 . The first feed valve 34 continues to be closed during these steps a. through c., while the second feed valve 35 is opened, so that purging gas S flows through the gas feed line 33 into the test module 30 and consequently into the gas-measuring device 40 and back again into the gas drain line 25 through the gas outlet 42 and the gas drain line 36 .
[0094] After receiving the information transmitted in step c., the control and analysis unit 21 selects, according to step d., a first test gas, which is suitable for the model of the gas sensor of the gas-measuring device 40 inserted, in this case the test gas P 3 , and connects the gas inlet 22 through which the selected test gas P 3 can be fed to the first gas feed line 23 corresponding to step e., as can be recognized in FIG. 2 c . It is recognized in FIG. 2 c that the test gas P 3 will then flow through the first gas feed line 23 .
[0095] According to step f., the test gas P 3 is then sent to the test module 30 , in which the gas-measuring device 40 is inserted. As can be recognized in FIG. 2 d , the second feed valve 35 is closed and the first feed valve 34 is closed for this. The selected test gas P 3 can thus flow in this case into the test module 30 and further into the gas-measuring device 40 . The gas-measuring device 40 then outputs a first measured value m1, which is passed on to the control and analysis unit 21 via the data exchange means 31 . A first measured value m1 of the gas sensor of the gas-measuring device 40 is thus detected according to step g.
[0096] After detection of the first measured value m1, it is recognized in FIG. 2 e that the gas-measuring device 40 is purged corresponding to step h. The first feed valve 34 is closed and the second feed valve 35 is opened for this. At the same time, the control and analysis unit 21 has already selected, according to step i., a second test gas P 1 , P 2 , P 3 , here the test gas P 1 , which is suitable for the model of the gas sensor of the gas-measuring device 40 inserted. Furthermore, the control and analysis unit 21 shown in FIG. 2 e has already transmitted the control command to the port 26 and has connected the first gas feed line 23 with the gas inlet 22 , through which the selected second test gas P 1 can be fed. The gas inlet 22 , through which the test gas P 1 can be fed, is already connected to the first gas feed line 23 according to step j.
[0097] According to step k., the test gas P 1 is then sent to the test module 30 , in which the gas-measuring device 40 is inserted. As can be recognized in FIG. 2 f , the second feed valve 35 is again closed for this and the first feed valve 34 is opened. The selected test gas P 1 can subsequently flow into the test module 30 and further into the gas-measuring device 40 . The gas-measuring device 40 then outputs a second measured value m2, which is passed on via the data exchange means 31 to the control and analysis unit 21 . A second measured value m2 of the gas sensor of the gas-measuring device 40 is thus detected according to step l. The control and analysis unit 21 thereupon determines, according to step m., based on the first measured value m1 detected and the second measured value m2 determined, whether a sensor poisoning is present. It is recognized in FIG. 2 f that the control and analysis unit 21 displays information on the result determined by means of the output unit 27 .
[0098] Gas-measuring devices 40 ′, 40 ″, 40 ′″, which were inserted into the test station 10 at different times, are located in a plurality of test modules 30 ′, 30 ″, 30 ′″ in FIG. 3 a . The gas-measuring devices 40 ′ and 40″ inserted into the test modules 30 ′ and 30″ are exposed to the test gas P 1 at the time indicated in FIG. 3 a . The first feed valves 34 ′ and 34″ belonging to the test modules 30 ′ and 30″ are opened, while the second feed valves 35 ′ and 35″ are closed. The test gas P 1 is not selected either as the first test gas or as the second test gas for the gas-measuring device 40 ′″ inserted into the test module 30 ′″. The feed valve 34 ′″ is therefore closed at the time shown in FIG. 3 a and the second feed valve 35 ′″ is opened. It is recognized, furthermore, in FIG. 3 a that the test gas P 1 is used for the gas-measuring device 40 ′ to determine the first measured value m1 for this gas-measuring device 40 ′. By contrast, the test gas P 1 is used for the gas-measuring device 40 ″ to determine already the second measured value m2 for this gas-measuring device 40 ′. The control and analysis unit 21 can therefore already determine for the gas-measuring device 40 ″ according to step m. whether sensor poisoning is present and it sends information about this by means of the analysis unit 27 . FIG. 3 a , therefore, shows the test station 10 at a time at which steps a. through d. and i. have been carried out independently from one another corresponding to step A of the above-described method for each of the gas-measuring devices 40 ′, 40 ″, 40 ′″ and at which it is determined, corresponding to step B of the above-described method, by means of the control and analysis unit 21 that the test modules 30 ′, 30 ″, 30 ′″ are equipped with gas-measuring devices 40 ′, 40 ″, 40 ′″. Furthermore, it is already determined at the time shown in FIG. 3 a according to step B which of the gas-measuring devices 40 ′, 40 ″, 40 ′″ need the same test gas P 1 as the next gas. These are the gas-measuring devices 40 ′ and 40″ in the case being shown. The gas-measuring device 40 ′ needs this test gas P 1 for carrying out step g. and the gas-measuring device 40 ″ needs this test gas P 1 for carrying out step l.
[0099] The gas-measuring device 40 ′ will consequently have run through steps a. through g. at the time shown in FIG. 3 a , the gas-measuring device 40 ′ will have run through steps a. through d. and the method is concluded for the gas-measuring device 40 ″ after step m. has been carried out.
[0100] Accordingly, as is recognized in FIG. 3 b , the gas-measuring device 40 ″ is removed from the test module 30 ″ at the next point in time. Therefore, gas-measuring devices 40 ′, 40 ′ are inserted into the test modules 30 ′ and 30 ′ only at the time shown in FIG. 3 b . Corresponding to step B of the above-described method, this is already determined by the control and analysis unit 21 . The feed valve 34 ″ is consequently closed already corresponding to step C of the above-described method. Furthermore, it is likewise determined corresponding to step B of the above-described method that the gas-measuring devices 40 ′ and 40 ′ inserted into the test modules 30 ′ and 30 ′″ already need both the test gas P 2 as the next test gas P 1 , P 2 , P 3 . The gas inlet 22 , through which the test gas P 2 can be fed, is then connected to the first gas feed line 23 . The feed valves 34 ′ and 34 ′″ are opened, and the feed valves 35 ′ and 35 ′ are closed. The test gas P 2 therefore flows both into the gas-measuring device 40 ′ and into the gas-measuring device 40 ′.
[0101] The second measured value m2 is detected in this case for the gas-measuring device 40 ′ according to step l., and it is determined by the control and analysis unit 21 according to step m. whether sensor poisoning is present, and it is recognized that the control and analysis unit 21 indicates the result of step m. by means of the output unit 27 .
[0102] At the same time, the first measured value m1 is detected according to step g. for the gas-measuring device 40 ′″.
[0103] The method is therefore concluded after carrying out step m. for the gas-measuring device 40 ′ at the time shown in FIG. 3 b . The gas-measuring device 40 ′″ will have run through steps a. through g. at this point in time.
[0104] The gas-measuring device 40 ′ is then removed from the test module 30 ′ at the time shown in FIG. 3 c . The next gas-measuring device 40 ″″ may already be inserted into the test module 30 ″. Steps 1. and m. are carried out for the gas-measuring device 40 ′″ at this point in time. The first gas feed line 23 is connected in this case to the gas inlet 22 , through which the test gas P 3 can be fed. It is recognized that steps a. through m. are carried out at least once for all three gas-measuring devices 40 ′, 40 ″, 40 ′″ inserted into the test station 10 at the time shown in FIG. 3 a , and the test station always carries out the following steps:
A. Carrying out steps a. and d. and/or carrying out step i. for each of the gas-measuring devices 40 ′, 40 ″, 40 ′″ independently from one another; B. Determining, by means of the control and analysis unit 21 , which of the test modules 30 ′, 30 ″, 30 ′″ are equipped with gas-measuring devices 40 ′, 40 ″, 40 ′″ and which of these gas-measuring devices 40 ′, 40 ″, 40 ′″ need the same test gas P 1 , P 2 , P 3 as the next test gas; C. Closing the feed valve 34 ′, 34 ″, 34 ″, which is arranged between the first gas feed line 23 and the respective test module 30 ′, 30 ″, 30 ′″, for all test modules 30 ′, 30 ″, 30 ′″, which do not need the test gas P 1 , P 2 , P 3 selected in B in the next step; and D. Carrying out steps e. through h. or steps j. through m. for each of the gas-measuring devices 40 ′, 40 ″, 40 ′″ determined in B independently from one another.
[0109] The test gas P 1 , P 2 , P 3 may be selected from among one of the following gas mixtures in all the above-described exemplary embodiments:
Propane; Propane mixed with H 2 S, CO, O 2 and/or CO 2 ; Pentane; Pentane mixed with H 2 S, CO, O 2 and/or CO 2 ; Butane; Hydrogen; Methane; Methane mixed with H 2 S, CO, O 2 and/or CO 2 ; and Mixtures of these gas mixtures mentioned.
[0119] For example:
test gas P 1 may be (2.5 vol. % CH 4 ); test gas P 2 may be (0.9 vol. % C 4 H 10 ); and test gas P 3 may be (mixed gas containing 0.4 vol. % C 3 H 8 , 18 vol. % O 2 , 2 vol. % CO 2 , 50 ppm CO, 15 ppm H 2 S in N 2 )
in the example described in FIGS. 2 a through 2 f as well as in the example described in FIGS. 3 a through 3 c.
[0123] Other test gases and other concentrations are, of course, conceivable.
[0124] All the features and advantages emerging from the description, claims and drawings, including design details, arrangements in space and method steps may be essential for the present invention both alone and in the different combinations. While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
[0000]
APPENDIX
A
Gas
P1
Test gas
P2
Test gas
P3
Test gas
S
Purging gas
10
Test station
20
Main unit
21
Control and analysis unit
22
Gas inlet
23
Gas feed line
24
Gas feed line
25
Gas feed line
26
Port
27
Output unit
28
Data exchange means
30
Test module
31
Data exchange means
32
Mount
33
Gas feed line
34
Feed valve
35
Feed valve
36
Gas drain line
37
Port
40
Gas-measuring device
41
Gas inlet
42
Gas outlet
50
Device model recognition means | A method for recognizing sensor poisonings in portable gas-measuring devices with a test station having a main unit with a control and analysis unit and test modules connected with the main unit for data exchange with an connected device. The test station recognizes device model and/or gas sensor model of the connected device. The main unit has gas inlets for different test gases and there is a first gas feed line for sending test gas to the test modules and a second gas feed line for sending purging gas to the test modules and a gas drain line to return gas from the test modules to the main unit. The method includes detection of a first measured value and of a second measured value and determination of sensor poisoning on the basis of the two values. The test station control and analysis unit carries out the method. | 6 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/870,486 filed Dec. 18, 2006.
TECHNICAL FIELD
[0002] The present invention relates in general to bollards and more specifically to a bollard system that includes a mechanism to deter efforts to disable the bollard as a physical barrier.
BACKGROUND
[0003] There has been a long-felt need to provide barriers to protect secured areas from encroachment by motor vehicles. These secure areas vary in size and purpose and include by without limitation, high pedestrian areas proximate to motor vehicle traffic, structures providing drive-through access, and approaches to structures. These secure areas also include road block situations such as border crossings and/or motor vehicle access areas. Unfortunately, in this era of increased terrorism and violence it is a desire to provide barriers in more locations and of sufficient strength and adaptability to deter and/or prevent numerous methods and means of unauthorized access. Commonly, bollards provide a physical barrier or deterrent to entry by a motor vehicle. However, bollard systems fail to provide a mechanism to prevent or deter the disabling of the bollard, for example by cutting, prior to an attempted impact breach.
SUMMARY
[0004] An example of a bollard, which is positioned in a structure having a grade level, includes an outer member having a first section extending above the grade level and an inner member rotatably positioned within the outer member.
[0005] Another example of a bollard, which is positioned in a structure having a grade level, includes an outer member having a first section extending above the grade level; an inner member having a filler material; and a connector operationally connecting the inner member and the outer member, wherein the inner member straddles the grade level and is rotatable relative to the outer member.
[0006] An example of a bollard, for installing into a structure with a portion of the bollard extending above ground level, includes an outer member and an inner member rotatably positioned within the outer member.
[0007] The foregoing has outlined some of the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing and other features and aspects of the present invention will be best understood with reference to the following detailed description of a specific embodiment of the invention, when read in conjunction with the accompanying drawings, wherein:
[0009] FIG. 1 is a conceptual view of an example of a bollard of the present invention.
DETAILED DESCRIPTION
[0010] Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
[0011] FIG. 1 is a conceptual view of an example of a bollard system of the present invention, generally denoted by the numeral 10 . System 10 includes a bollard 12 mounted into a structure such as the ground 14 having a surface or grade level “GL”. In the illustrated example, bollard 12 is secured in the ground by a subsurface support such as concrete. However, it should be recognized that bollard 12 may be driven into ground 14 or secured in various manners.
[0012] Bollard 12 is a double-walled structure that provides strength against impact and deterrence to tampering. Bollard 12 includes an outer tubular member 18 and an inner member 20 . Outer tubular 18 may be constructed of any material to resist deformation upon impact from a motor vehicle, such as without limitation a metal pipe. Tubular 18 may have a circular cross-section or another geometric cross-section and may be referred to as a housing. The term tubular is utilized herein to include elongated members having an open interior or cavity. Outer tubular 18 includes an upper section 22 positioned above grade and a lower portion that is positioned below grade.
[0013] Inner member 20 may be constructive of various materials and for purposes of the illustrated example is constructed of a metal pipe. In the illustrated example, inner member 20 is includes a filler 26 , which may provide reinforcement for bollard 12 . In the illustrated example reinforcement is provided by the concrete filler 26 and reinforcement bars 28 .
[0014] Inner member 20 is rotatably positioned within the interior 24 of outer member 18 , so as to rotate or spin relative to outer member 18 . Inner member 20 may be functionally connected to outer tubular 18 in various manners to allow for rotational movement of inner member 20 relative to outer tubular 18 . For example, inner member 20 may be rotatably positioned in the earth and then outer tubular may be placed over it. Inner member 20 is connected to outer tubular 18 by an operational connector 30 . Operational connector 30 is particularly adapted to deter destruction of bollard 12 by cutting. For example, if one were to attempt to cut through bollard 12 the process would be stopped or delayed by inner member 20 rotating upon contact of the cutting blade.
[0015] Various assemblies may be utilized as operational connector 30 to support and provide rotation of inner member 20 relative to outer tubular 18 , it is noted that inner member 20 may not be physically connected directly to tubular 18 . In the illustrated example, connector assembly 20 is a swivel type assembly including a support structure 32 carrying or serving as a swivel 34 and a link 36 interconnecting structure 23 and inner member 20 .
[0016] In the illustrated example support structure 32 is as a cap, however it may be another type member such as a bar connected across tubular 18 . Support structure 32 may further be positioned above or below inner member 20 . Connecting link 36 , such as a metal shaft, chain or other linking member, is connected via swivel 34 between cap 32 and inner member 20 . Swivel 34 may include various mechanical devices or rotating connections. Swivel 34 may be provided at one or more locations such as, the connection between link 36 and cap 32 , the connection between link 36 and inner member 20 , and within a position on link 36 . In the illustrated example link 36 is a chain connected to one of the reinforcing member 32 . In the illustrated example, the provision of a connector assembly 30 forming a connection from the top of bollard 12 through inner member 18 maintains the subassemblies in connection when a disabling action is being attempted.
[0017] In operation, bollard 12 is installed within ground 14 or other structure such that upper section 22 is positioned above grade. Inner member 20 is rotatably positioned within outer member 18 so as to straddle the grade, illustrated by above grade portion 20 a and below grade portion 20 b . A stop 38 may be positioned below inner member 20 a distance “D” so as to maintain inner member 20 in an operational position if link 36 is parted. For example, if link 36 were cut, inner member 20 would rest atop stop. 40 and still extend above grade GL. Without link 36 in operation, inner member 20 is swiveling connected to outer member 18 by stop 40 . In effect, stop 40 serves as swivel connection 34 . It should be noted that it may be desired for swivel assembly 34 to be positioned below the grade to further prevent tampering.
[0018] From the foregoing detailed description of specific embodiments of the invention, it should be apparent that bollard that is novel has been disclosed. Although specific embodiments of the invention have been disclosed herein in some detail, this has been done solely for the purposes of describing various features and aspects of the invention, and is not intended to be limiting with respect to the scope of the invention. It is contemplated that various substitutions, alterations, and/or modifications, including but not limited to those implementation variations which may have been suggested herein, may be made to the disclosed embodiments without departing from the spirit and scope of the invention as defined by the appended claims which follow. | A bollard, which is positioned in a structure having a grade level, includes an outer member having a first section extending above the grade level; an inner member having a filler material; and a connector operationally connecting the inner member and the outer member, wherein the inner member straddles the grade level and is rotatable relative to the outer member. | 4 |
This application is a national phase of International Application No. PCT/US2014/035843 filed Apr. 29, 2014 and published in the English language, which claims priority to U.S. Provisional Application No. 61/816,975 filed Apr. 29, 2013.
TECHNICAL FIELD
The present invention relates to a polymeric matting article, and in particular, to a polymeric matting article configured to be foldable onto itself and secured in a folded position by engaging interlocking formations.
SUMMARY
In one aspect of the invention there is provided a polymeric matting article that includes a web of extruded polymer monofilaments, the polymer monofilaments being heat welded at junctions to form a matrix of tangled monofilament; and at least one pair of interlocking formations; wherein the web is configured to be foldable onto itself and secured in a folded position by engaging the interlocking formations.
The extruded polymer monofilaments of the matting article may be composed of a polyolefin, polyamide, polyester, polyvinylhalide, polystyrene, polyvinylester, or a mixture of two or more thereof.
In one embodiment, the interlocking formations include an elongated rib and a complementary elongated channel into which the elongated rib fits in a folded position.
In one embodiment, the web of extruded polymer monofilaments includes top and bottom shell halves and a hinge integrally formed with and interconnecting the top and bottom shell halves, the top and bottom shell halves cooperatively defining a filament free cavity.
In one embodiment, the polymeric matting article is a packaging material.
In another embodiment, the polymeric matting article is a building construction material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a portion of the polymeric matting article formed from tangled polymer filaments.
FIGS. 2A and 2B are perspective views of an embodiment of the polymeric matting article having an elongated rib and a complementary elongated channel in an unfolded position and in a folded position, respectively, in accordance with the present invention.
FIGS. 3A and 3B are cross-sectional views of an embodiment of the polymeric matting article having a clam shell configuration with complementary interlocking domes in an unfolded and folded position, respectively.
DETAILED DESCRIPTION
The polymeric matting article of the present invention is formed from a web of extruded polymer monofilaments. The fibrous web is extruded onto a substrate having a surface profile corresponding to that of the desired matting article, the matting article configured to be foldable onto itself and secured in a folded position by engaging interlocking formations
Referring to FIG. 1 , a portion of the matting article is shown. The matting article is constructed of a web 10 formed from a plurality of extruded polymer monofilaments 12 . The plurality of filaments 12 that are heat fused to one another at randomly spaced points to form a three-dimensional, convoluted and mutually interconnected filamentatious body having an open structure. Filament free voids 13 are formed within the resilient structure, which allows air flow within the structure while allowing the structure to absorb impacts. The polymer filament material is preferably constructed in accordance with techniques such as disclosed by, for example, U.S. Pat. Nos. 3,687,759; 3,691,004; and 4,212,692, the contents of all of which are hereby incorporated by reference in their entireties.
The monofilaments 12 of web 10 may be made from any thermoplastic polymer that provides the desired properties of strength and resilience for the application in which it is used. For example, the monofilaments 41 may be made of a polyolefin (e.g., polyethylene, polypropylene, etc.), polyamide (e.g., Nylon), polyester, polyvinylhalide (e.g., polyvinylchloride (PVC), polyvinylidene chloride, polyvinyltetrafluoride, polyvinyl chlorotrifluoride), polystyrene, polyvinylester (e.g., polyvinyl acetate, etc.) or a mixture of two or more thereof. The monofilaments 12 are extruded onto a substrate having the desired structural profile to form the web 10 .
Referring to FIGS. 2A and 2B , in one embodiment the matting article 20 includes an elongated channel 22 positioned between a first raised region 32 and a second raised region 34 , the raised regions 32 and 34 including a thickness of entangled filaments extending from the a first surface 36 of the matting article. The second raised region 34 is closest to the fold line 26 and is adjacent a flat planar region 30 on the opposite side of the fold line 26 . Adjacent the flat planar region 30 is an elongated rib 24 having a width that is the same or less than the width of the elongated channel 22 . The matting article 20 is illustrated in FIG. 2A in its unfolded position. Arrow 28 indicates the fold direction of the matting article 20 . The matting article 20 is illustrated in FIG. 2B in its folded position. Upon folding the matting article 20 along fold line 26 in the folding direction, the elongated rib 24 fits into and engages the elongated channel 22 to form a device having a uniform thickness. The device may be, for example, a lightweight, resilient building construction device. The building construction device being useful for providing, for example, cushioning, drainage, air circulation and/or sound damping when included as part of a building structure.
Referring to FIGS. 3A and 3B , in one embodiment the matting article 40 has a clam shell configuration, including a bottom shell half 42 and a top shell half 44 that are connected by connecting section 46 . Matting article 40 is illustrated in FIG. 3A in the unfolded, or open position. The bottom shell half 42 has an outer lip 56 that includes a downwardly facing locking dome 54 B. The top shell half 44 has an outer lip 58 that includes an upwardly facing locking dome 54 A, which is complementary to locking dome 54 B. The connecting section 46 , which acts as a flexible hinge for the matting article 40 , includes a pair of complementary interlocking domes 52 A and 52 B positioned on opposing sides of fold line 48 . Arrow 50 indicates the fold direction of the matting article 40 . FIG. 3B illustrates the matting article 40 in the folded, or closed position. Upon folding the matting article 40 along fold line 48 in the folding direction, dome 52 A engages dome 52 B and dome 54 A on the outer lip 58 of the top shell half engages dome 54 B on the outer lip 56 of the bottom shell half to secure the matting article in a closed position. Matting article 40 may be useful, for example, as a packaging material or as a building construction component for drainage and/or air circulation.
While the invention has been explained in relation to various embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading this specification. Therefore, it is to be understood that the invention provided herein is intended to cover such modifications as may fall within the scope of the appended claims. | A polymeric matting article includes a web of extruded polymer monofilaments, the polymer monofilaments being heat welded at junctions to form a matrix of tangled monofilament; and at least one pair of interlocking formations; wherein the web is configured to be foldable onto itself and secured in a folded position by engaging the interlocking formations. | 3 |
BACKGROUND OF THE INVENTION
[0001] When standing and talking with a relative in front of their fireplace, I became aware of the aroma of recent burned firewood. I also become overwhelmed with sympathy for I was glad I did not have this difficult task of cleaning this fireplace before me. I recalled thinking there had to be a better way to clean a fireplace without exposing yourself to the dirty mess of cleaning ash, the health risk of breathing these particles, and the ungodly amount of time expended on this task.
BRIEF SUMMARY OF THE INVENTION
[0002] This invention is a safe, simple, revolutionary new cleaning system that greatly reduces the amount of time and mess when cleaning a fireplace after burning firewood or artificial fire logs.
[0003] This very simple invention takes some of the same materials currently used in the firebox of the fireplace. Its basic concept is to add a tray or a removable floor to the firebox that can be easily removed and dumped outside into a disposal receptacle.
[0004] It improves upon fireplace cleaning by giving the laborer the ability to carry away most, if not all, the ash in one fleeting moment with little or no mess.
[0005] Several optional items maybe used in conjunction with the ashtray to make its use more convenient and long lasting. First a custom-fit cover is placed over the ashtray to trap the ash within the tray as it is transported to a fireproof receptacle for disposal. Secondly, the tray has optional detachable handles for lifting and carrying the ashtray to it disposal receptacle.
[0006] Built to last, the main components of the system are the ashtray, liner, tray handles, and temporary storage receptacle.
[0007] Steps have been taken to accommodate the many sizes and shapes of fireplaces. All fireboxes are not of the same height, width, and length; the ashtray must catch the ash as it falls to the floor of the firebox. It is best that the ashtray be “custom fitted” to your fireplace. With a better fit, the ash lands in the tray and not around it, minimizing additional cleanup.
[0008] Several other benefits are realized besides time and less mess. More real wood can be burned since the hard task of cleaning up the fireplace is eliminated. Conversely, it also cuts back on using non-renewable energy products like artificial and gas fire logs.
[0009] The metal tray (especially the custom-fit version) radiates the heat from the floor of the fireplace back to the center of the firebox where heat is drawn out into the room adding more heating and comfort.
[0010] From start to finish, anyone with this product can clean the fireplace within fifteen minutes or less.
[0011] The Fireplace Ashtray minimizes airborne ash and flying dust particles when cleaning the fireplace. All ash and dust is trapped in the tray.
BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWINGS
[0012] This patent application contains four drawing. These drawings are not required per the instruction outline in Patent and Trademark Office (PTO) literature. However, several drawings of two different types of ashtrays have been submitted. Each is discussed in detail in the following paragraphs.
[0013] At first glance, the only difference between the six-sided tray (pages 10/11) and the four-sided tray (pages 12/13) is the number of sides (four as opposed to six). All sides are modified or custom-fit.
[0014] As discussed earlier, all fireplaces are not made the same, but all designs must not block, hinder or touch the natural gas pipe that jettison from the firebox wall. The same is true for the ventilation ducts and vents.
DETAILED DESCRIPTION OF THE INVENTION
[0015] This section describes the components for which I seek a patent, followed by several safety and convenience items. The best mode of operation is to have all items available to aid in cleanup. The last section describes a step-by-step narration of the its proper use
[0016] Patented Components
[0017] The two main components of the tray are the ashtray and tray liner. Each is listed below with a specification.
[0018] Ash Tray
[0019] The tray can accommodate of plethora of sizes, but the best mode of operation is to have the tray custom-fitted to the floor of the firebox. This accommodates the many sizes and shapes of the firebox. The better the fit, the better the chances that all of the ash will remain in the tray and not fall outside or around it.
[0020] The tray is made from fourteen to sixteen gauge galvanized steel. The tray can have up to six sides depending on the design of the fireplace. The sides of the tray are approximately two inches high. The side(s) of the tray can be modified to accommodate the easy removal and replacement of the tray. Each side is folded at a ninety-degree angle with the top edge folded over forming a flange; this strengthens the sides of the tray.
[0021] The tray is drilled in four places (off-centered), two holes in the front and back allowing for the attachment of the tray handles.
[0022] The tray is painted with a high-temperature fire resistant paint (usually flat black) for cosmetics.
[0023] Tray Liner
[0024] The tray liner is made of a proprietary refractory material made by Thorley Industries located in the City of Industry, California. It is tan in color and is made of refractory material similar to the wall linings of a kilm or ceramic-making furnace. The tray liner protects the tray from excessive heat emanating from the fire, thus extending the life of the tray by keeping it from warping.
[0025] The liner is approximately one-half to three-quarters of an inch in thickness. The width of the liner is approximately twenty to twenty-four inches depending on the size of the tray. The liner can be cut to make a precise fit in the tray. The tray liner does not necessarily need to cover the entire tray. It must cover the center area where most of the heat is generated and where most of the protection is need. The tray liner can also be painted with a high-temperature fire resistant paint (usually flat black) for cosmetic reasons.
[0026] Optional Cleaning and Safety Items
[0027] A list of optional components is detailed below. They are part of the safety and convenience package. The fireplace ashtray can be used and operated without these items, but, as noted below, they provide an added degree of comfort and safety.
[0028] Tray Handles—The tray handles are made from over-the-counter link chain, usually thirteen to sixteen inches in length with a snap clamp on each end for attachment. The tray handles facilitate easy removal, transport, and replacement of the tray.
[0029] For added comfort, a soft plastic tube is pasted over the chain to prevent pinching by handles during use.
[0030] Temporary Storage Receptacle (Ash Can)—This can is a fireproof receptacle that is placed outside and away from any flammable items. One may fail to ensure embers from a fireplace are completely extinguished. For safety reasons, before dumping the ash into a permanent receptacle for disposal, temporary storage is provided to allow ash and embers to completely extinguish. This ashcan can be simple or fancy; it is usually made of steel. It is important to keep the ash separated from other combustibles until it is completely extinguished.
[0031] Ashtray Cover—The tray cover looks a lot like the fireplace ashtray. The main differences are the lighter gauged steel and the side notches cut out to allow the cover to fit over the ashtray during transporting to a disposable receptacle.
[0032] Cleaning Brush—A generic hand cleaning brush is used to sweep the ash off the tray and tray liner.
[0033] Dust Mask—Dust mask come in handy when the ash is dumped outside. The dust mask deters the inhalation of ash and dust particles that may flies during the outside dumping.
[0034] Plastic Gloves—Gloves, like the ones medical professionals wear, keep the hand and fingernails from get dirty during this entire process.
[0035] Safety Glasses—Glasses, like the ones mechanics wear provide added eye protection.
[0036] Best Mode of Operation:
[0037] The best mode of operation follows:
[0038] 1. First, spread newspaper in front of the fireplace, usual about three overlapping sheets, enough to allow the grate to set. Ensure the grate is out of the way so it does not become a tripping hazard.
[0039] 2. Don your optional safety equipment (gloves, mask, and goggles).
[0040] 3. Gently, remove the grate from the firebox while trying not to disturb the ash. Do not allow the grate to impact the tray liner. The tray liner is very fragile.
[0041] 4. Attach the optional tray handles to facilitate the removal of the ashtray from the firebox. Attach the front set of handles; then drag the tray out just far enough to attach the rear handles. Some balancing may be required. As you become familiar with the process, you may decide not to use the handles and omit this step.
[0042] 5. Remove the tray from the firebox using the handles or both hands and set it on the newspaper.
[0043] 6. Attach the tray cover. The cover should slide right over the tray.
[0044] 7. Lift the tray by the handles and carry it outside to the temporary storage receptacle. Ensure that you do not drop, shake, or stumble with the ashtray full of ash.
[0045] 8. Once outside, remove the tray cover.
[0046] 9. Grab the dust broom, tilt the ashtray, and gently sweep the ash into the disposal receptacle. Remember to secure the ashtray and tray liner because they are two separate pieces. Be extra careful when handling the tray liner, it is very fragile.
[0047] 10. Once the ash is disposed, brush clean the tray and liner.
[0048] 11. After cleaning, the tray, liner, and grate, placed all items back into the fireplace for its next use.
[0049] 12. Pick up all newspaper and put away all cleaning items. | This invention is a metal tray that is removed quickly and easily from the fireplace after burning firewood. It must be manually transported to a disposal receptacle for dumping ash then returned to the fireplace thus greatly eliminating messy cleanup. | 5 |
TECHNICAL FIELD
The invention relates generally to troffer-style luminaires (“troffers”) and more particularly, to a troffer that uses indirect light from light emitting diodes to output light with low glare and good cutoff.
BACKGROUND
A luminaire is a system for producing, controlling, and/or distributing light for illumination. For example, a luminaire can include a system that outputs or distributes light into an environment, thereby allowing certain items in that environment to be visible. Luminaires are often referred to as “light fixtures”.
A troffer is a light fixture that includes a relatively shallow, inverted trough-shaped housing (or “trough”) within which at least one light source is disposed. The trough includes a substantially closed top end and a bottom end with an opening through which light from the light source is emitted. Generally, the trough is either suspended from a ceiling or other surface or installed in an opening therein. For example, the trough can be recessed within the ceiling, with the bottom end of the trough being flush with the ceiling. Traditional troffers include fluorescent light sources, with one or more fluorescent lamps extending across a length of each troffer.
Increasingly, lighting manufacturers are being driven to replace fluorescent lamp fixtures with light emitting diode (“LED”) fixtures because LEDs tend to have better longevity than fluorescent lamps. Existing LED troffers include multiple LEDs spaced along the length of a top, interior surface of the troffer, with each LED pointing downward, into the environment to be illuminated. Because the LEDs are separate, bright light sources that emit light directly into the environment, the existing LED troffers generally emit light with bright and dark spaced spots onto a surface and poor cutoff. In particular, light emitted by the existing LED troffers tends to result in a substantial amount of glare because the shallow troughs of the LED troffers do not allow the LEDs to be recessed deep enough to achieve good cutoff. Accordingly, a need currently exists in the art for an improved LED troffer with reduced glare, improved cutoff, and more consistent light output.
SUMMARY
The invention provides a troffer that uses indirect light from LEDs to output light with low or no glare and good cutoff. The troffer includes a frame having first and second side ends. A top end of the frame can include top edges of the side ends. The top end also may include one or more top members and/or reflectors extending between the side ends. The frame also can include one or more bottom members extending across at least a portion of a bottom end of the frame. The ends of the frame define an interior region within the frame.
A first plurality of LEDs are coupled along an interior surface of the first side end, within the interior region. The troffer may or may not also include a second plurality of LEDs coupled along an interior surface of the second side end, within the interior region. For example, a troffer that only includes the first plurality of LEDs may emit light in a substantially asymmetric distribution, and a troffer that includes both the first and second pluralities of LEDs may emit light in a substantially symmetric distribution.
At least some of the LEDs can be coupled to their respective interior surface by being wedged between first and second members protruding into the interior region from the interior surface or another surface. In addition, or in the alternative, one or more spring clips can apply a force that presses the LEDs to the interior surfaces. For example, each spring clip can be at least partially disposed around one of the protruding members, with an end of the spring clip pressing an end of a substrate associated with the LEDs against the interior surface. As described in more detail below, pressing the substrates to the interior surfaces allows for transfer of thermal energy from the LEDs to the interior surfaces.
A reflector extends between the LEDs and the top end of the frame and reflects light from the LEDs towards a bottom end of the frame. The reflected, indirect light from the LEDs is emitted through the bottom end, into a desired environment. For example, the reflector can include a single arc-shaped member that extends between the side ends and reflects light from the first plurality of LEDs. Alternatively, the reflector can include two arc-shaped members that extend between the side ends. Each arc-shaped member can be associated with one of the first and second pluralities of LEDs and can reflect light generated therefrom. Because the light generated by the LEDs is indirectly emitted into the environment, via the reflector, the light emitted by the troffer has reduced glare and better cut-off compared to traditional LED troffers that directly emit light from shallowly-recessed LEDs. In certain exemplary embodiments, the bottom members, if any, block light from traveling directly from the LEDs to the environment, providing additional protection from glare as well as enhanced cut-off.
These and other aspects, features and embodiments of the invention will become apparent to a person of ordinary skill in the art upon consideration of the following detailed description of illustrated embodiments exemplifying the best mode for carrying out the invention as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description, in conjunction with the accompanying figures briefly described as follows.
FIG. 1 is a perspective bottom view of a troffer, in accordance with certain exemplary embodiments.
FIG. 2 is an exploded view of the troffer of FIG. 1 , in accordance with certain exemplary embodiments.
FIG. 3 is a partial perspective view of an interior region of the troffer of FIG. 1 , in accordance with certain exemplary embodiments.
FIG. 4 is a partially exploded side view of the troffer of FIG. 1 , in accordance with certain exemplary embodiments.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The following description of exemplary embodiments refers to the attached drawings, in which like numerals indicate like elements throughout the figures. FIGS. 1-4 illustrate a troffer 100 , according to certain exemplary embodiments. With reference to FIGS. 1-4 , the troffer 100 includes a frame 105 having a first side end 105 a , a second side end 105 b , and a top end 105 c extending between the first side end 105 a and the second side end 105 b . Third and fourth side ends 105 e and 105 f extend between the side ends 105 a and 105 b , on opposite sides of the frame 105 . In certain exemplary embodiments, each side end 105 a - b and 105 e - f extends from the top end 105 c at a substantially orthogonal angle.
In certain exemplary embodiments, the troffer 100 also includes a pair of bottom members 105 d extending towards one another, between the first and second side ends 105 a and 105 b . Each bottom member 105 d extends from a respective one of the side ends 105 a and 105 b . In certain exemplary embodiments, each bottom member 105 d extends from its respective side end 105 a , 105 b at a substantially orthogonal angle. An aperture 106 extends between the bottom members 105 d , substantially along an axis thereof.
In certain exemplary embodiments, each bottom member 105 d is integrally formed with its respective side end 105 a , 105 b , and the top end 105 c is integrally formed with at least one of the side ends 105 a - b and 105 e - f . For example, the members 105 d and/or top end 105 c can be formed with one or more of the side ends 105 a - b and 105 e - f via molding, casting, extrusion, or die-based material processing. Alternatively, at least one of the bottom members 105 d , the top member 105 c , and/or the side ends 105 a - b and 105 e - f can include a separate component that is separately coupled to at least one of the other components via solder, braze, welds, glue, plug-and-socket connections, epoxy, rivets, clamps, fasteners, or other fastening means. Although the exemplary embodiment is depicted in the figures as having a substantially rectangular-shaped geometry, alternative embodiments of the frame 105 have any of a number of different shapes, including, without limitation, a square shape and a frusto-conical shape. For example, in certain exemplary embodiments, one or more of the side ends 105 a - b and 105 e - f can be angled outward or inward relative to the top end 105 c . In addition, the frame 105 may not include a top member 105 c in certain alternative exemplary embodiments. In such embodiments, top edges of the side ends 105 a - b and 105 e - f can define a top end of the frame 105 .
The frame 105 also is capable of being configured in a number of different sizes. In certain exemplary embodiments, the frame 105 is two feet wide by two feet long. In other exemplary embodiments, the frame 105 is two feet wide by four feet long. A person of ordinary skill in the art having the benefit of the present invention will recognize that these sizes are merely exemplary and the frame 105 can have any other size in alternative exemplary embodiments. The frame 105 is configured to be suspended from, or recessed within, a ceiling or other surface (not shown).
The side ends 105 a - b and 105 e - f together with the top end 105 c and the bottom members 105 d define an interior region 107 . As best seen in FIG. 4 , each side end 105 a , 105 b includes a heat sink member 110 that has an interior side 110 a within the interior region 107 and an exterior side 110 b disposed opposite the interior side 110 a , outside of the interior region 107 . The interior side 110 a includes a top platform 108 and a bottom platform 109 . Each of the platforms 108 and 109 includes an elongated member that extends substantially perpendicularly or angularly from the interior side 110 a , into the interior region 107 . Each of the platforms 108 extends longitudinally along the length of its respective side end 105 a , 105 b . The top platform 108 engages and at least partially supports a reflector 150 , as described below. Each bottom platform 109 and a ridge 111 extending angularly from an interior side 105 d a of the bottom platform's corresponding bottom member 105 d support a substrate 120 for one or more LEDs 115 , as described below.
The substrates 120 and LEDs 115 are thermally coupled to the interior sides 110 a , along longitudinal axes thereof. More specifically the substrates 120 and LEDs 115 on each interior side 110 a are disposed substantially along a longitudinal axis of the interior side's corresponding side end 105 a , 105 b . In certain exemplary embodiments, some or all of the LEDs 115 on each side 110 a are mounted nearly end to end on a common substrate 120 , substantially in the form of a “strip.” Alternatively, groups of one or more of the LEDs 115 can be mounted to their own substrates 120 . In certain alternative exemplary embodiments, the troffer 100 can include LEDs 115 disposed only on one of the interior sides 110 a . In such embodiments, the troffer 100 can emit light in a substantially asymmetric distribution.
Each substrate 120 includes one or more sheets of ceramic, metal, laminate, circuit board, mylar, or another material. Each LED 115 includes a chip of semi-conductive material that is treated to create a positive-negative (“p-n”) junction. When the LEDs 115 are electrically coupled to a power source, such as a driver 125 , current flows from the positive side to the negative side of each junction, causing charge carriers to release energy in the form of incoherent light.
The wavelength or color of the emitted light depends on the materials used to make each LED 115 . For example, a blue or ultraviolet LED typically includes gallium nitride (“GaN”) or indium gallium nitride (“InGaN”), a red LED typically includes aluminum gallium arsenide (“AlGaAs”), and a green LED typically includes aluminum gallium phosphide (“AlGaP”). Each of the LEDs 115 is capable of being configured to produce the same or a distinct color of light. In certain exemplary embodiments, the LEDs 115 include one or more white LEDs and one or more non-white LEDs, such as red, yellow, amber, green, or blue LEDs, for adjusting the color temperature output of the light emitted from the troffer 100 . A yellow or multi-chromatic phosphor may coat or otherwise be used in a blue or ultraviolet LED to create blue and red-shifted light that essentially matches blackbody radiation. The emitted light approximates or emulates “white,” incandescent light to a human observer. In certain exemplary embodiments, the emitted light includes substantially white light that seems slightly blue, green, red, yellow, orange, or some other color or tint. In certain exemplary embodiments, the light emitted from the LEDs 115 has a color temperature between 2500 and 5000 degrees Kelvin.
In certain exemplary embodiments, an optically transmissive or clear material (not shown) encapsulates at least some of the LEDs 115 , either individually or collectively. This encapsulating material provides environmental protection while transmitting light from the LEDs 115 . For example, the encapsulating material can include a conformal coating, a silicone gel, a cured/curable polymer, an adhesive, or some other material known to a person of ordinary skill in the art having the benefit of the present disclosure. In certain exemplary embodiments, phosphors are coated onto or dispersed in the encapsulating material for creating white light. In certain exemplary embodiments, the white light has a color temperature between 2500 and 5000 degrees Kelvin.
Although illustrated in the figures as being arranged in a substantially rectangular-shaped geometry, a person of ordinary skill in the art having the benefit of the present disclosure will recognize that the LEDs 115 can be arranged in any geometry. For example, in certain alternative exemplary embodiments, the LEDs 115 are configured in circular or square-shaped geometries. The LEDs 115 are coupled to the substrate(s) 120 by one or more solder joints, plugs, screws, glue, epoxy or bonding lines, and/or other means for mounting an electrical/optical device on a surface. Similarly, each substrate 120 is typically coupled to one of the interior sides 110 a by one or more solder joints, plugs, screws, glue, epoxy or bonding lines, and/or other means for mounting an electrical/optical device on a surface. In certain exemplary embodiments, each substrate 120 is coupled to its corresponding interior side 110 a by a two-part arctic silver epoxy.
In addition, or in the alternative, one or more spring clips 145 applies pressure to at least a portion of each substrate 120 to couple the substrate(s) 120 to the interior sides 110 a . Each spring clip 145 is disposed at least partially around one of the bottom platforms 109 , with an end 145 a of each spring clip 145 engaging a first end 120 a of each substrate(s) 120 . Each spring clip 145 applies pressure for holding the substrate 120 up against the interior side 110 a . A second, opposite end 120 b of each substrate 120 rests on at least a portion of the ridge 111 proximate the side 110 a . The ridge 111 and spring clip 145 essentially wedge the substrate 120 against the side 110 a . In certain exemplary embodiments, the substrate 120 is coupled to the side 110 a by placing the bottom end 120 b between the ridge 111 and the side 110 a , placing the top end 120 a flush against the side 110 a , and engaging each spring clip 145 to the bottom platform 109 so that the end 145 a of the spring clip 145 engages the top end 120 a . In certain alternative exemplary embodiments, the troffer 100 does not include the ridge 111 , and each substrate 120 rests on the interior side 105 d a of its corresponding bottom member 105 d.
The LEDs 115 are electrically connected to the driver 125 , which supplies electrical power to, and controls operation of, the LEDs 115 . For example, one or more wires (not shown) couple opposite ends of each substrate 120 to the driver 125 , thereby completing one or more circuits between the driver 125 , substrate(s) 120 , and LEDs 115 . In certain exemplary embodiments, the driver 125 is configured to separately control one or more portions of the LEDs 125 to adjust light color and/or intensity. Although illustrated in the figures as being disposed within the interior region 107 , substantially along a center of the top member 105 c , the driver 125 can be located substantially anywhere else in or remote from the troffer 100 , in certain alternative exemplary embodiments.
As a byproduct of converting electricity into light, LEDs 115 generate a substantial amount of heat that raises the operating temperature of the LEDs 115 if allowed to accumulate. This heat can result in efficiency degradation and premature failure of the LEDs 115 . Each heat sink member 110 is configured to manage heat output by the LEDs 115 . In particular, each heat sink member 110 is configured to conduct heat away from the LEDs 115 by increasing the amount of surface area thermally coupled to the LEDs 115 . Each heat sink member 110 is composed of any material configured to conduct and/or convect heat, such as die cast or extruded metal.
As set forth above, the interior side 110 a of each heat sink member 110 includes a surface to which the LEDs 115 and substrates 120 are thermally coupled. At least one fin 160 extends from the exterior side 110 b of each heat sink member 110 , away from the interior region 107 . Each fin 160 includes an elongated member that extends longitudinally at least partially along its respective side end 105 a , 105 b . In certain exemplary embodiments, multiple fins 160 extend substantially perpendicular from and longitudinally along, and are spaced laterally apart along, the respective side ends 105 a and 105 b , between the top end 105 c and a corresponding one of the bottom members 105 d . Although illustrated in the figures as having a substantially rectangular-shaped geometry, each fin 160 is capable of having any of a number of different shapes and configurations. For example, each fin 160 can include a solid or non-solid member having a substantially rectilinear, rounded, or other shape.
Each heat sink member 110 is configured to dissipate heat from the LEDs 115 thermally coupled thereto along a heat-transfer path that extends from the LEDs 115 , through the substrate 120 , and to the fins 160 via the respective end 105 a , 105 b associated with the substrate 120 . The fins 160 receive the conducted heat and transfer the conducted heat to the surrounding environment (typically air in the ceiling) via convection. In certain exemplary embodiments, heat from the LEDs 115 and substrate 120 is transferred along a path from the LEDs 115 to the substrate 120 , from the substrate 120 to the side 110 a , from the side 110 a through the respective side end 105 a , 105 b to the first end 160 a of one or more of the fins 160 , from each first end 160 a to a second end 160 b of the corresponding fin 160 , and from each second end 160 b to the surrounding environment. Heat also can be transferred by convection directly from the side 110 b and/or the fins 160 to one or more gaps between the fins 160 .
As best viewed in FIG. 2 , the reflector 150 includes a member with two substantially arc-shaped segments 151 a and 151 b that converge along a line extending from the center of side end 105 e to the center of side send 105 f . Each segment 151 includes a first end 152 that engages a top surface 108 a of a respective one of the top platforms 108 , and a second end 153 that converges with the second end 153 of the other segment 151 . The top platforms 108 support at least a portion of the weight of the reflector 150 . In certain exemplary embodiments, the first end 152 extends angularly from a main body portion 154 of each segment 151 , so that the first end 152 is substantially flush with the top platform 108 . Alternatively, the first end 152 extends along the main body portion 154 without the first end 152 being flush with the top platform 108 . Each main body portion 154 is substantially convex, extending upward from the first end 152 , towards the top member 105 c , and downward from an apex 155 (of the main body portion 154 ) proximate the top member 105 c , towards the second end 153 .
Each segment 151 includes a reflective surface formed on one or both sides, or coupled thereto, for reflecting light generated by the LEDs 115 located proximate the first end 152 of the segment 151 . In particular, segment 151 a reflects light generated by the LEDs 115 coupled to the first side end 105 a , and segment 151 b reflects light generated by the LEDs 115 coupled to the second side end 105 b . Alternatively, segment 151 a can reflect light generated by the LEDs 115 coupled to the second side end 105 b , and segment 151 b can reflect light generated by the LEDs 115 coupled to the first side end 105 a . The reflected light travels downward from the reflector 150 , between the bottom members 105 d . Thus, the troffer 100 indirectly emits light generated by the LEDs 115 into an environment beneath the troffer 100 . Because the light generated by the LEDs 115 is indirectly emitted into the environment, via the reflector 150 , the light emitted by the troffer 100 has reduced glare and better cut-off compared to traditional LED troffers that directly emit light from shallowly-recessed LEDs. In certain exemplary embodiments, the bottom members 105 d block light from traveling directly from the LEDs 115 to the environment, providing additional protection from glare as well as enhanced cut-off. In certain alternative exemplary embodiments, one or both of the side ends 105 a and 105 b , and/or the LEDs 115 coupled thereto, can be angled relative to the top end 105 c to help enhance cut-off.
In certain exemplary embodiments, a lens 170 extends between the bottom members 105 d , filling at least a portion of the aperture 106 . The lens 170 includes an optically transmissive or clear, refractive or non-refractive material (not shown) that provides environmental protection for the LEDs 115 and other internal components of the troffer 100 while also transmitting light from the LEDs 115 into the environment. The lens 170 may not be included in certain alternative exemplary embodiments.
Although specific embodiments of the invention have been described above in detail, the description is merely for purposes of illustration. It should be appreciated, therefore, that many aspects of the invention were described above by way of example only and are not intended as required or essential elements of the invention unless explicitly stated otherwise. Various modifications of, and equivalent steps corresponding to, the disclosed aspects of the exemplary embodiments, in addition to those described above, can be made by a person of ordinary skill in the art, having the benefit of this disclosure, without departing from the spirit and scope of the invention defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures. | A troffer-style luminaire includes first and second side ends and a top end extending between the side ends. The side and top ends define an interior region. Light emitting diodes (“LEDs”) are coupled along interior surfaces of the side ends, within the interior region. At least some of the LEDs are coupled to the interior surfaces by being wedged between members protruding into the interior region from the interior or other surfaces. In addition, or in the alternative, one or more spring clips can apply a force that holds the LEDs against the interior surfaces. A reflector extends between the LEDs and the top member and reflects light from the LEDs towards a bottom end of the frame. The light emitted by the LEDs is directed to the reflector and then indirectly emitted through the bottom end, into a desired environment. | 5 |
TECHNICAL FIELD
[0001] The present disclosure relates to illumination, and more particularly, to an LED (light emitting diode) lamp having changeable light effect.
DESCRIPTION OF RELATED ART
[0002] LEDs have many advantages, such as high luminosity, low operational voltage, low power consumption, compatibility with integrated circuits, easy driving, long term reliability, and environmental friendliness. Such advantages have promoted the wide use of LEDs as a light source. Nowadays, LED lamps are commonly applied in general lighting. However, the LED lamps in different lighting spaces have different lighting requirements. Generally, the LED lamp with small lighting field can meet the lighting requirement of a small space, and the LED lamp with large lighting field can meet the lighting requirement of a large space. However, light sources of the typical LED lamp is often fixed. Thus, the lamp is difficult to satisfy different lighting requirements for spaces of different sizes.
[0003] What is needed, therefore, is an LED lamp having changeable light effect to overcome the above described shortcomings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the views.
[0005] FIG. 1 is an isometric, assembled view of an LED lamp in accordance with a first embodiment of the present disclosure.
[0006] FIG. 2 is similar to FIG. 1 , but shows a second light device pulled out from a first light device of the LED lamp.
[0007] FIG. 3 is an enlarged view of a circled part III of FIG. 1 .
[0008] FIG. 4 is an isometric, assembled view of an LED lamp in accordance with a second embodiment of the present disclosure.
[0009] FIG. 5 is similar to FIG. 4 , but shows a second light device pulled out from a first light device of the LED lamp.
[0010] FIG. 6 is similar to FIG. 5 , but shows the second light device separated from the first light device.
[0011] FIG. 7 is similar to FIG. 6 , but from another aspect.
DETAILED DESCRIPTION
[0012] Referring to FIGS. 1-3 , an LED lamp 10 in accordance with a first embodiment of the present disclosure is shown. FIG. 1 shows a retracted status of the LED lamp 10 , FIG. 2 shows an extended status of the LED lamp 10 . The LED lamp 10 includes a first light device 11 and a second light device 12 similar to the first light device 11 . The he first light device 11 and the second light device 12 are both strip-shaped. The second light device 12 is installed inside the first light device 11 (shown in FIG. 1 ), and can be pulled out from the first light device 11 (shown in FIG. 2 ).
[0013] The first light device 11 includes a strip-shaped first cover 110 and a first light strip 111 received in the first cover 110 . The first cover 110 is hollow with two opposite open ends. Alternatively, a top end 115 thereof can also be closed. The first cover 110 includes a front wall 112 , a rear wall 114 and two side walls 116 interconnecting the front and rear walls 112 , 114 . A light transmission window 1120 is defined in a middle of the front wall 112 . The first cover 110 further includes a dividing plate 118 formed in an inner chamber 1100 of the first cover 110 . The dividing plate 118 connects two middles of the two side walls 116 . The dividing plate 118 is parallel to the front wall 112 . The dividing plate 118 divides the inner chamber 1100 of the first cover 110 into a first receiving space 117 adjacent to the front wall 112 of the first cover 110 and a second receiving space 119 adjacent to the rear wall 114 of the first cover 110 . The first receiving space 117 is smaller than the second receiving space 119 . The first light strip 111 is received in the first receiving space 117 . The first light strip 111 includes a plurality of LEDs 113 exposed through the light transmission window 1120 of the front wall 112 .
[0014] The second light device 12 includes a strip-shaped second cover 120 and a second light strip 121 received in the second cover 120 . The second cover 120 includes a front wall 122 , a rear wall 124 and two side walls 126 interconnecting the front and rear walls 122 , 124 . The second cover 120 is smaller than the second receiving space 119 , and the second light device 12 is movably mounted in the second receiving space 119 . A light transmission window 1220 is defined in a middle of the front wall 122 . The second light strip 121 includes a plurality of LEDs 123 exposed through the light transmission window 1220 of the front wall 122 . An operating portion 128 is formed on a bottom of the second cover 120 . The operating portion 128 is semicircular and has a thickness equal to that of the first light device 11 .
[0015] The second light device 12 is completely received in the second receiving space 119 except the operating portion 128 when the LED lamp 10 is in a retracted status. The operating portion 128 covers and abuts against the open bottom of the first cover 110 . At this status, only the LEDs 113 of the first light device 11 are working, so the LED lamp 10 produces less light and form a relatively small light field. Thus, the LED lamp 10 can be used in a small space which does not need too much light. When the LED lamp 10 is required to be applied in a larger space, the second light device 12 is pulled out from the first light device 11 by pulling the operating portion 128 downwardly. A length of the second light device 12 exposed outside of the first light device 11 can be controlled by operating the operating portion 128 , so that a number of the exposed LEDs 123 of the second light device 12 can be changeable. Only the exposed LEDs 1220 are working by photosensitive control or other control methods for energy saving. Thus, the LED lamp 10 has a changeable light effect to meet different lighting requirements. The operation to change the lighting effect of the LED lamp 10 is simple just by pulling the second light device 12 out from the first light device 11 or pushing the second light device 12 in the first light device 11 .
[0016] Referring to FIGS. 4-5 , an LED lamp 20 in accordance with a second embodiment of the present disclosure is shown. FIG. 4 shows a retracted status of the LED lamp 20 , and FIG. 5 shows an extended status of the LED lamp 20 . The LED lamp 20 includes a first light device 21 and a second light device 22 similar to the first light device 21 . The LED lamp 20 in this embodiment has a shape similar to that of the LED lamp 10 in the first embodiment. The first light device 21 includes a strip-shaped first cover 210 and a first light strip 211 received in the first cover 210 . The first cover 210 includes a front wall 212 , a rear wall 214 and two side walls 216 interconnecting the front and rear walls 212 , 214 . A semicircular operating portion 218 is formed on a bottom of the first cover 210 . The operating portion 218 has a thickness equal to that of the first cover 210 . A light transmission window 2120 is defined in a middle of the front wall 212 . The first light strip 211 includes a plurality of LEDs 213 exposed through the light transmission window 2120 of the front wall 212 .
[0017] The second light device 22 includes a second cover 220 and a second light strip 221 received in the second cover 220 . The second cover 220 includes two front walls 222 , a rear wall 224 and two side walls 226 interconnecting the two front walls 222 and the rear wall 224 . The two front walls 222 are connected to the two side walls 226 , respectively. A light transmission hole 2220 is defined between the two front walls 222 . The second light strip 221 includes a plurality of LEDs 223 exposed through the light transmission hole 2220 of the front wall 222 . An operating portion 228 is formed on a bottom of the second cover 220 . The operating portion 228 is similar to the operating portion 218 of the first light device 21 and has a thickness equal to a thickness of the second cover 220 . The second light device 22 is mounted to the rear wall 214 of the first light device 21 .
[0018] Referring to FIGS. 6-7 , two sliding slots 2221 are defined respectively in the two front walls 222 of the second lighting device 22 . The two sliding slots 2221 are extended from top ends of the front walls 222 to the operating portion 228 of the second light device 22 . The two sliding slots 2221 are located near the two side walls 226 , respectively. Two sliding bars 2141 are formed on the rear wall 214 of the first light device 21 corresponding to the two sliding slots 2221 of the second light device 22 . The two sliding bars 2141 are extended from a top end of the rear wall 214 downwardly to a position corresponding to the operating portion 218 .
[0019] The two sliding bars 2141 of the first light device 21 are received in the two sliding slots 2221 of the second light device 22 , whereby the second light device 22 is movably mounted to the first light device 21 . The second light device 22 is completely covered by the first light device 21 when the LED lamp 20 is used in a small space. At this status, only the LEDs 213 of the first light device 21 are working. When the LED lamp 20 is used in a larger space, the second light device 22 is exposed by pulling the operating portion 228 downwardly. Only the exposed LEDs 223 are working by photosensitive control or other control methods for energy saving. Thus, the LED lamp 20 has a changeable light effect to meet different lighting requirements. The operation to change the lighting of the LED lamp 20 is simple just by pulling the second light device 22 out from the first light device 11 or pushing the second light device 22 towards the first light device 11 .
[0020] It is understood, the lengths of the first light device 11 , 21 and the second light device 12 , 22 can be different. The LED lamp 10 , 20 can include more than two light devices. Besides sliding, the first light device 11 , 21 can also be moved relative to the second light device 12 , 22 through other methods such as rotation.
[0021] It is believed that the present disclosure and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the present disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments. | An LED lamp includes a first light device and a second light device. The first light device includes a first cover and a first light strip received in the first cover. The second light device included a second cover and a second light strip received in the second cover. The second light device is movably mounted to the first light device. A light emitting area of the second light strip of the second light device is changeable according to movement of the second light device relative to the first light device whereby a total light emitting area of the LED lamp is adjustable. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the control of fluid flow into a wellbore. More particularly, the invention relates to a flow control apparatus that is self adjusting to meter production and choke the flow of gas into the wellbore.
[0003] 2. Description of the Related Art
[0004] In hydrocarbon wells, horizontal wellbores are formed at a predetermined depth to more completely and effectively reach formations bearing oil or other hydrocarbons in the earth. Typically, a vertical wellbore is formed from the surface of a well and thereafter, using some means of directional drilling like a diverter, the wellbore is extended along a horizontal path. Because the hydrocarbon bearing formations can be hundreds of feet across, these horizontal wellbores are sometimes equipped with long sections of screened tubing which consists of tubing having apertures therethough and covered with screened walls, leaving the interior of the tubing open to the inflow of filtered oil.
[0005] Horizontal wellbores are often formed to intersect narrow oil bearing formations that might have water and gas bearing formations nearby. FIG. 1 illustrates two such nearby formations, one of water and one of gas. Even with exact drilling techniques, the migration of gas and water towards the oil formation and the wellbore is inevitable due to pressure drops caused by the collection and travel of fluid in the wellbore. Typically, operators do not want to collect gas or water along with oil from the same horizontal wellbore. The gas and water must be separated at the surface and once the flow of gas begins it typically increases to a point where further production of oil is not cost effective. Devices have been developed that self adjust to control the flow of fluid into a horizontal wellbore. One such device is shown in U.S. Pat. No. 6,371,210 owned by the same assignee as the present invention and that patent is incorporated by reference in its entirety herein. The '210 patent teaches a self-adjusting device that chokes the flow of fluid into a horizontal wellbore as the flow of fluid increases relative to a preset value determined by a spring member. Multiple devices can be placed along the length of a wellbore to help balance the inflow of production throughout the length of the wellbore. The device includes a piston that is depressed by a force generated by fluid flow. The device is especially useful when several are used in series along the length of a horizontal wellbore. However, the devices are not designed to meter production while choking unwanted production components due to its lack of a constantly sized orifice though which to meter the flow of production and determine the relative amounts of gas or water.
[0006] There is a need therefore, for a self-adjusting flow control apparatus for downhole use in a wellbore that operates to limit the inflow of gas or water into the wellbore when that component in a production stream reaches a predetermined percentage relative to the oil. There is a further need, for a flow control apparatus for use in a wellbore that is self-regulating and self-adjusts for changes in the amount of fluid and gas in a production stream. There is yet a further need for a flow control apparatus that meters the flow of production into a horizontal wellbore.
SUMMARY OF THE INVENTION
[0007] The present invention provides an apparatus for use in a hydrocarbon producing wellbore to prevent the introduction into the wellbore of gas and/or water when the gas or water is of a given percentage relative to the overall fluid content of the production. In one aspect of the invention, a perforated inner tube is surrounded by at least one axially movable member that moves in relation to a pressure differential between sides of a piston having at least one sized orifice through which the production flows to enter the wellbore. The movable member selectively exposes and covers the perforations of the inner tube to pass or choke production. In another embodiment, a method is disclosed to choke the flow of production into a wellbore when a predetermined component of the production is made up of gas or water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
[0009] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, For the invention may admit to other equally effective embodiments.
[0010] FIG. 1 depicts a partial cross-sectional view of a vertical and horizontal hydrocarbon wellbore having a sand screen in the horizontal wellbore.
[0011] FIG. 2 is a partial cross-sectional view of the apparatus of the subject invention in an open position.
[0012] FIG. 3 is another cross-sectional view of the apparatus shown in a closed, choked position.
[0013] FIG. 4 is a cross-sectional view of a portion of the apparatus along a line 4 - 4 of FIG. 2 .
DETAILED DESCRIPTION
[0014] The present invention is intended to effectively monitor and self adjust the flow of production into a wellbore depending upon the components in the production. To facilitate the description of the invention, the device will typically be described as it would function in the presence of gas and oil in a production stream. However, it will be understood that the invention operates primarily due to differences in densities between oil and another component of production in a wellbore and could operate in the presence of oil and water or any other component having a density distinct from oil. FIG. 1 depicts a cross-sectional view of a well 200 having a flow control apparatus 212 of the present invention located therein. Specifically, an apparatus 212 for controlling the flow of oil or some other hydrocarbon from an underground reservoir 203 through the well 200 is depicted. The well 200 includes a cased, vertical wellbore 202 and an uncased, horizontal wellbore 204 . Production tubing 209 for transporting oil to the surface of the well is disposed within the vertical wellbore 202 and extends from the surface of the well 200 through a packing member 205 that seals an annular area 211 around the tubing and isolates the wellbore therebelow. The horizontal wellbore 204 includes a section of screened tubing 206 . The screened tubing 206 continues along the horizontal wellbore 204 to a toe 208 thereof. The apparatus 212 is attached to the screened tubing 206 near the heel 210 of the horizontal wellbore 204 .
[0015] FIG. 2 is a more detailed view of the apparatus 212 of the present invention. In the embodiment of FIG. 2 , the flow control apparatus 212 is a two-position apparatus with a first position preventing the flow of production and a second position permitting the inflow of production into the production tubing 209 . The apparatus 212 is shown in the second, open position. The apparatus 212 is additionally designed to assume any number of positions between the first and second positions, thereby providing an infinitely adjustable restriction to the inflow of production into the interior of the device.
[0016] The apparatus 212 includes an inner tubular body 307 and an outer tubular body 324 disposed therearound. Disposed in an annular area 305 between the inner 306 and outer 324 bodies is an axially slidable sleeve member 311 which is biased in a first position relative to the inner body 307 by a spring 320 or other biasing member. In the position shown in FIG. 2 , apertures 317 formed in the sleeve 311 are substantially aligned with mating apertures 308 formed in the inner body 307 to permit the passage of production fluid from the wellbore into the inner tube 307 . The production fluid flow into the apparatus is illustrated by arrows 313 . A piston surface 318 is formed on the sleeve 311 and is constructed and arranged to cause the sleeve 311 to become deflected and to move axially in relation to the inner body when acted upon by production fluid with sufficient momentum, mass and density to overcome the resistive force of the spring 320 and a pressure differential across the sleeve 311 . Specifically, the spring 320 is selected whereby a mass flow rate created by a pressure differential will result in a fluid momentum adequate to deflect the sleeve 311 , thereby shifting the apparatus 212 from the first fully closed position to the second, open position as it is shown in FIG. 2 .
[0017] Formed in the piston surface 318 are at least one orifice 321 that meters the flow of production into the apparatus 212 and defines the pressure differential across the sleeve 311 based on flow rate and density of the fluids passing through the orifice 321 . In the design shown in FIG. 2 , the only fluid path to the inner tube 307 is through the orifice 321 which is sized to permit flow but also to meter the production fluid as it travels through the sleeve 311 . In a preferred embodiment, when a certain percentage of the production fluid is made up of oil, its density will be adequate to cause a sufficient pressure differential as it flows through the orifice 321 to depress the sleeve 311 while an adequate amount flows through the orifice 321 sized to permit the flow of oil. If however, a substantial amount of gas is a component of the production fluid (or any other substance with a lower density than oil), the gas will not have adequate density to cause a sufficient pressure differential as it flows through the orifice 321 to depress the sleeve 311 , and any gas traveling through the orifice will be prevented from flowing into the wellbore. For some embodiments, the orifice 321 may not be formed in the sleeve 311 as long as the orifice 321 meters flow across the sleeve 311 . For example, the orifice 321 can be an insert that is locked (threaded, brazed, etc.) in place.
[0018] FIG. 3 is another section view of the apparatus 212 in the first or closed position. Accordingly, FIG. 3 illustrates the position of the sleeve 311 when there is not an adequate amount of force to depress the piston surface 318 due possibly to a lack of density in some component of the production.
[0019] FIG. 4 is a section view illustrating the radially spaced orifices 321 formed in the sleeve 311 . In the embodiment shown, there are six orifices that serve to meter the inflow of production. The piston surface 318 which must be acted upon and depressed by pressure developed by the production fluid is the surface area of the face of the sleeve 311 less the area of the orifices 321 . The orifices are sized to meter the flow of production permitting an adequate amount to flow through while the surface area of the piston and the spring member 320 against which it must act are designed to require that the production be made up of some predetermined, minimum amount of higher density oil than some other lower density material, like water or gas.
[0020] While the invention has been described as being fully self adjusting, it will be understood that in some instances the device might be remotely adjusted from the surface using a hydraulic control line to artificially influence movement of the sleeve or a solenoid that is battery powered and can be signaled from the surface of the well. At least one pressure sensor (not shown) can sense a pressure value and communicate the pressure value to the solenoid.
[0021] While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | Methods and apparatus for use in a wellbore to meter and choke certain components from being produced, based upon their density relative to the density of oil are disclosed. The device includes an inner tubular body portion having apertures in the wall thereof for passing oil, an outer tubular body and at least one metering orifice therebetween to meter production. Disposed around the inner body is an axially movable member to selectively cover and expose the apertures of the inner body, thereby permitting fluid to flow therethrough. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO MICROFICHE APPENDIX
Not Applicable.
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to gun sighting mounts and is concerned with gun mounts used in the sighting of long barrel guns having a magazine or other under gun ammunition feed system.
The invention is more particularly concerned with the sighting-in of high powered and/or semi-automatic and/or automatic long barrel weapons.
Many different types of gun mounts have been used, in the past, to aim and sight-in long guns. Recently, however, there have been many more gun owners desiring to sight-in high powered, automatic weapons.
Because high powered, extremely fast firing long guns discharge rounds at a very rapid rate, the weapons often have large bullet holding magazines, clips or belts that project beneath the weapon during use. It is therefore necessary that any gun mount used in sighting-in such weapons provide clearance beneath the supported weapon for such bullet holding and feed structures. At the same time, because of the explosive power of the bullets fired through the weapons, it is highly desirable that the weapon be mounted on structure that will absorb much of the shock resulting from the rapidly fired rounds used in aiming and sighting-in the weapon.
Additionally, many features found on known gun sighting mounts still need to be incorporated into a gun mount that will accommodate sighting of long guns having a bullet feed mechanism extending beneath the gun.
Consequently, a gun mount used for sighting long guns with bullet holding magazines, or the like, must also provide for vertical and horizontal adjustments to allow accurate sighting and locking in of a sight picture. It is also desirable to minimize recoil shock, and particularly recoil shock that may change the sight picture between successive shots.
Even though many gun mount devices have been proposed in the past for securing long guns during aiming and sighting-in, there remains a need for such a mount that will hold rapid firing, high powered long guns in a secured set position, during aiming and sighting-in.
BRIEF SUMMARY OF THE INVENTION
Objects of the Invention
Principal objects of the present invention are to provide a gun mount that can be conveniently positioned on a shooting table top or other suitable surface and that will receive and hold long guns during the aiming and sighting-in of such weapons.
Other objects of the invention are to provide a gun mount having ample clearance for a bottom loading magazine or other bullet holding and feed mechanism inserted into and projecting from the underside of a gun being aimed or sighted-in.
Another object of the invention is to provide a gun mount that is stable during aiming and sighting-in procedures and that will at least partially absorb and minimize the recoil shock occurring as rounds are fired and discharged from the muzzle of the weapon.
Still another object of the invention is to provide a weighted mount for aiming and sighting-in of rapid firing, high caliber long guns that can be easily setup, on a table, for example, to permit a user to raise, lower and horizontally rotate the barrel of a gun while aiming and sighting-in the weapon during single shot firing, semi-automatic firing, and fully automatic firing.
Yet another object is to provide a gun mount that will permit rotation of the gun being sighted in a horizontal plane as well as vertical pivoting of the gun muzzle when setting up a sight picture. The gun is locked in place to maintain the sight picture and shock absorbers are provided to prevent or reduce the possibility of the sight picture at any selected range will be lost due to recoil action of the weapon.
Features of the Invention
Principal features of the invention include a gun mount having a base with legs that are adjustable to permit leveling of the base. The base also has trays that can be readily filled with bags of sand, or other weights to further stabilize the base during use of the gun mount.
The gun mount further include a gun holder rotatably mounted on the base to permit horizontal alignment of a long gun positioned on the gun holder and a vertical adjustor to adjust and secure the gun sights for vertical position on a target.
The gun holder positions the gun to have clearance beneath the gun to accommodate a bottom ammunition feed system of the gun.
Shock absorbers acting between the base and the gun holder at least partially absorb recoil to minimize repositioning of the gun being sighted, and particularly to absorb torque forces that might otherwise occur if the gun being sighted-in is offset with respect to the pivot axis through a base bottom plate and an overlying central plate of the gun holder.
Additional objects and features of the invention will become apparent from the following drawings and detailed description.
BRIEF DESCRIPTION OF THE FIGURES OF THE INVENTION
In the Drawings
FIG. 1 is a top plan view of a gun mount of the invention;
FIG. 2 is a side elevation;
FIG. 3 is a perspective view taken from a front upper corner, of the invention, and showing the gun mount without shock absorbers;
FIG. 4 , a perspective view taken from a rear corner of another embodiment of the invention and showing an automatic rifle positioned on the gun holder;
FIG. 5 , a perspective view of the gun mount of the invention shown in FIG. 4 , but with the automatic rifle removed and with the view being taken from a front corner and slightly above the mount;
FIG. 6 , a top plan view of an embodiment of the invention shown in FIGS. 1-3 and including shock absorbers;
FIG. 7 , a side elevation view of the embodiment of the invention having a straight support arm positioned over the axis on which the gun holder rotates; and
FIG. 8 , a side elevation view of the embodiment of the invention shown in FIG. 7 , but showing shock absorbers connected between the base and the gun holder to absorb recoil shock of the weapon being fired while using the gun mount.
DETAILED DESCRIPTION
Referring Now to the Drawings
In the illustrated preferred embodiment shown in FIGS. 1-3 , the gun mount of the invention is shown generally at 10 . Gun mount 10 includes a base 12 having a bottom pivot plate, shown generally at 14 and a gun holder, shown generally at 16 . Bottom pivot plate 14 has tripod legs, comprising front legs 18 , 20 and a rear leg 22 , each fixed to and projecting outwardly and downwardly from the bottom pivot plate 14 .
Gun holder 16 is mounted on a pivot shaft formed by a bolt 26 that extends downwardly through the central pivot plate 32 through bottom pivot plate 14 and leg 22 . Rotation of the gun holder 16 and a gun positioned thereon will rotate a bottom face 30 of the central pivot plate 32 of the gun holder 16 around pivot shaft 26 and on a top surface 34 of bottom plate 14 . A nut 27 on the pivot shaft 26 , beneath the top surface of leg 22 holds the pivot shaft 26 in place.
A threaded post 36 is fixed to the top surface 34 of plate 14 of the base 12 and extends upwardly through an arcuate slot 38 formed through the bottom pivot plate 14 of the gun holder. The ends 40 and 42 of the arcuate slot 38 serve as stops to limit rotation of the central pivot plate 32 and the gun holder 16 supported thereon, relative to the bottom pivot plate 14 .
A knob 46 , threaded onto the upper end of threaded post 36 that projects through the arcuate slot 38 , can be turned downwardly on the threaded post 36 to clamp the bottom pivot plate 14 and central pivot plate 32 together. This prevents undesired rotation of the central pivot plate on the bottom pivot plate and horizontally sets a sight picture.
Gun holder 16 includes a pair of spaced apart upstanding plates 50 and 52 fixed to and projecting upwardly from the top surface of central pivot plate 34 .
A support arm 54 has a straight central portion 56 that extends between and beyond the upright plates 50 and 52 . A bolt pivot 58 , having an end cap 60 thereon, is inserted through plate 50 , support arm 54 and plate 52 . Thus, the support arm will rotate in a vertical plane on the pivot bolt 58 .
A vertical adjustment bolt 62 is threaded through the support arm 54 and into a foot member 64 that rests on top of the central pivot plate 32 . A knob 66 is fixed to the top of bolt 62 and is used to turn the bolt 62 through support arm 54 and to move the foot member 64 into engagement with a leading edge 68 of central pivot plate 32 . A coil spring 70 extends between a pocket 72 formed in the bottom of the support arm 54 and the top surface 34 at a trailing edge 76 of the plate 32 .
The front legs 18 and 20 each have an adjustable foot 78 on the end thereof remote from the bottom plate 14 . Each foot 78 is on the bottom end of a bolt 80 threaded through the end of the leg and a knob 82 is provided on and is affixed to the top of each bolt 80 so that turning of the knob will thread the bolt through and change the position of the foot relevant to the leg. A foot 84 is provided on the bottom surface of rear leg 22 , at the end of leg 22 remote from bottom plate 14 .
A weight receiving tray 86 is formed between each of the front legs 18 and 20 and the rear leg 22 . The trays each include a flat surface 88 on which sand bags or other weights (not shown) may be placed. A peripheral rim 90 is provided around each tray 86 , between a front leg 18 or 20 and the rear leg 22 to better hold the weights in place.
A front portion 98 of the support arm 54 extends beyond the knob 66 and is angled at 100 to extend angularly from one end of the central portion 56 of arm 54 . A barrel support 102 is attached to and extends upwardly from the free end of the forward angled portion 98 of arm 54 . The barrel support includes a U-shaped receiver 104 having spaced apart wings 106 extending upwardly from a web 108 . A threaded post 110 is attached to and extends from beneath web 108 and through a nut 112 and the free end of forward portion 98 of arm 54 , and is threaded into a nut 114 . The elevation of barrel support 102 is set by adjusting the position of nuts 112 and 114 on post 110 .
A rear portion 118 of support arm 54 is also angled at 119 from the central portion 56 of arm 54 to the same side of the central portion 56 as is the forward portion 98 . A stock support 120 is mounted on the free end of rear portion 118 of support arm 54 . Stock support 120 includes a receiver 122 for the butt of a long gun stock and has spaced apart wings 124 and 126 projecting upwardly from a platform 128 . The wings and platform are connected by a rear plate 130 . A bolt 129 extends downwardly from platform 128 and through rear portion 118 . A nut 131 threaded on bolt 129 secures the receiver 122 to the portion 118 of arm 54 . A cushion 132 is positioned on a back, shoulder engaging surface of rear plate 130 .
The front portion 90 and rear portion 118 of support arm 54 may extend outwardly to have the free ends an equal distance from the axis through the central portion 56 . Thus when a gun is positioned with the gun barrel in the barrel support 102 and the gun stock is positioned in the stock support 120 with the butt of the stock, against the rear plate 130 , the gun axis is on the dotted line axis shown at 134 . The gun axis is offset from and substantially parallel to the central portion 56 of arm 54 . With gun 28 so positioned, and offset from being above the plates 14 and 34 there is ample room for a magazine, or other bottom feed ammunition system extending beneath the gun as it is fired and sighted-in, using the gun mount 10 .
Whenever a long gun and particularly a high-powered gun, or a very fast firing automatic gun is fired on a gun mount, the recoil from firing may change a sighting picture both horizontally and vertically. Such recoil naturally tends to change the sighting picture even if the gun holder is positioned directly above a base structure on which the gun holder is positioned. When the gun barrel is positioned to be on a line that is offset from the base structure supporting the gun being fired from a gun mount, the recoil force may also result in a torque force that can also change the horizontal sight picture of a sighted-in gun.
As shown in FIGS. 4-8 , a pair of parallel extending shock absorbers 136 and 138 are provided with a shock absorber on each opposite side of and extending parallel to the support arm 54 . The shock absorbers serve to minimize the effects of recoil shock. Each shock absorber includes a cylinder 140 having a rear tab 142 through which a shaft 144 is inserted. Each shaft 144 is fixed to and projects from one of the upstanding plates 50 or 52 . A rod 146 projecting from each cylinder 140 has a free end 148 pivotally connected at 150 to a shaft 152 that is fixed to and projects from the arm 54 .
A pivot link 154 is provided at each side of the arm 54 . Each pivot link 154 has one end 156 pivotally mounted on a shaft 158 that extends through the links and the arm 54 . Nuts 160 threaded on the ends of shaft 158 hold the shaft in place. Opposite ends 162 of the links 154 are pivotally connected on a shaft 164 . Shaft 164 extends through the upstanding plates 166 and 168 that are welded to the central pivot plate 32 . Nuts 172 threaded on opposite ends of the shaft hold the shaft in place.
Each pivot link 154 has an impact edge 176 that is slightly spaced away from a rear edge 178 of the adjacent upright plate 50 or 52 . A lower end of the impact edge has a curved corner 180 interconnecting the impact edge with a bottom edge of the pivot link 154 .
In use of the gun mount 10 , the mount is positioned on a table or other suitable stable surface with the legs 18 , 20 and 22 resting on the surface.
A gun 186 , FIG. 4 , to be fired and sighted-in is placed in the gun holder 16 with the barrel supported in the barrel support 102 and the butt of the gun in the receiver 122 of stock support 120 .
As previously described and shown in FIGS. 1-3 , the support arm has angled front and rear ends 98 and 118 , respectively, extended such that gun axis of a gun placed on the gun holder 16 that is pivotally mounted on the base 12 will be parallel to the dotted line axis 184 . With the gun so positioned, recoil force is directed along the gun axis to the rear plate 130 of stock support 120 . The recoil force, with the gun axis positioned as shown in FIG. 1 and FIG. 2 creates a torque force to pivot the gun in a horizontal axis around the pivot shaft 26 .
As the gun is rotated on the gun support 16 , around the pivot shaft 26 , the projecting lengths of the rods of the shock absorbers 126 and 138 individually change as the shock absorbers absorb the force of arm 54 moving rearward and absorb torque force around the pivot shaft 26 .
If the gun axis is over the pivot shaft 26 , the shock absorber rods 136 and 138 , fixed to the arm 54 , will move substantially together to absorb all or part of the recoil shock as the recoil shock acts on the butt plate 130 .
Whether the gun holder has an arm 54 with a central arm portion 56 and angled front and rear portions 98 and 118 , respectively in straight alignment with an axis 190 overlying the pivot shaft 26 , as shown in FIG. 6 ; or has an arm 54 with front and rear angled portions 98 and 118 to form a gun holder having a gun axis offset from and parallel to the central portion 56 of arm 54 as shown in FIGS. 1-3 ; or has an arm 54 with one front or rear portion forming a straight connection with central portion 56 and the other front or rear portion angled from the central portion 56 of arm 54 , as shown in FIGS. 4-6 , the shock absorbers will receive recoil shock transmitted from a gun being fired through the butt of the stock of the rifle and end plate to move the arm 54 rearwardly.
As the arm 54 moves rearwardly it pivots upper ends 154 of links 156 and rotates the lower end 162 of the links 156 about pivot shaft 164 . Pivot shaft 164 extends through spaced apart plates 166 that are welded to central pivot plate 32 . The lower curved edges 180 of links 156 are then rotated into engagement with upstanding plate 50 and 52 to stop further rearward movement of arm 54 . The shock absorbers then return the links 156 and the arm 54 to their start positions, ready to modulate recoil from the next round fired from the gun.
Although a preferred embodiment of our invention has been herein described, it is to be understood that the present disclosure is by way of example and that variations are possible without departing from the subject matter coming within the scope of the following claims, which subject matter we regard as our invention. | A gun mount for use in sighting-in long guns having or not having a large bottom feed, clip magazine, belt, drum or other bottom loaded ammunition feed system includes a base to be mounted on a table top or other suitable surface and that supports a rotatably mounted gun holder on which a long gun is placed. The gun holder allows the gun barrel to be adjustably fixed in each of a horizontal and vertical position. An aligned sight picture is set into the gun sights and is maintained or reset after the gun is fired by shock absorbers that keep recoil shock from changing the sight settings, or return the gun to the position at which the sights have been set. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an ophthalmic apparatus for performing observation or treatment by illuminating an eye of a patient.
[0003] 2. Description of Related Art
[0004] As an ophthalmic apparatus for observing a patient's eye, there is known a slit lamp for projecting slit-shaped illumination light on the patient's eye, thereby allowing observation through an observation optical system, or a laser treatment apparatus constructed by a combination of the slit lamp and a laser irradiation device.
[0005] These ophthalmic apparatus each cause an illumination light source provided inside of the apparatus to project illumination light on the patient's eye to thereby performing observation and treatment. A tungsten lamp, a halogen lamp or the like is generally used for the illumination light source.
[0006] However, an illumination light source using a lamp is short in service life. Thus, such illumination light source requires frequent replacement, which is cumbersome and imposes burden on operators or the like. In addition, the lamp has a large heat rate during illumination, and may have a thermal effect on its periphery. It is therefore required to pay attention to a material or an installation position, etc. of the periphery of the illumination light source during design.
[0007] The slip lamp is provided with a mechanism to insert/remove a wavelength selection filter for enabling fluorescent observation or the like into/from an illumination optical path. This may increase complexity in configuration of the apparatus.
[0008] In many cases, a laser treatment apparatus for performing photocoagulation or the like is provided with a protective filter disposed in an observation optical path in order to protect an operator's eye from a laser beam for treatment reflected from the patient's eye or the like. However, in the case of observation through a protective filter for cutting a visible treatment laser beam, an observation image looks more colorful than that in the case where no protective filter is provided, has strangeness, and makes it difficult to ensure observation.
SUMMARY OF THE INVENTION
[0009] The present invention has been made in view of the above mentioned technical problems. It is an object of the present invention to provide an ophthalmic apparatus provided with an illumination light source which is easy-to-handle and arranged in simplified configuration.
[0010] Another object of the present invention is providing an ophthalmic apparatus capable of facilitating observation even in the presence of a protective filter during laser treatment.
[0011] In order to solve the foregoing problems, the present invention is characterized by comprising the following constituent elements.
[0012] According to a first aspect of the present invention, there is provided an ophthalmic apparatus including: an illumination optical system for illuminating an eye of a patient, the illumination optical system including a plurality of LEDs which are illumination light sources for emitting beams of light of wavelengths in different regions and a composing optical system for composing optical paths of the beams of light emitted from the LEDs; an observation optical system for observing the patient's eye; and a light quantity control section capable of controlling an illumination light quantity of each of the LEDs to produce substantially white illumination light.
[0013] According to another aspect of the present invention, there is provided an ophthalmic apparatus including: an illumination optical system for illuminating an eye of a patient, the illumination optical system including a plurality of LEDs which are illumination light sources for emitting beams of substantially white light and a composing optical system for composing optical paths of the beams of light emitted from the LEDS; an observation optical system for observing the patient's eye; and a light quantity control section for controlling the light emission quantity of each of the LEDs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate an embodiment of the invention and, together with the description, serve to explain the objects, advantages and principles of the invention.
[0015] In the drawings,
[0016] [0016]FIG. 1 is an external view showing a laser treatment apparatus in an embodiment according to the present invention;
[0017] [0017]FIG. 2 is a schematic view showing an optical system of the apparatus;
[0018] [0018]FIG. 3 is a block diagram schematically showing a control system of the apparatus;
[0019] [0019]FIG. 4 is a view showing wavelength characteristics of each LED;
[0020] [0020]FIG. 5 is a view showing wavelength transmission characteristics of a protective filter; and
[0021] [0021]FIG. 6 is a block diagram schematically showing a mechanism for selectively lighting LEDs.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] A detailed description of a preferred embodiment of an ophthalmic apparatus embodying the present invention will now be given referring to the accompanying drawings. The present embodiment exemplifies a laser treatment apparatus as the ophthalmic apparatus according to the present invention. FIG. 1 is an external view showing a laser treatment apparatus for performing photocoagulation treatment by irradiating a laser light beam for treatment (hereinafter, merely referred to as a treatment beam) to the periphery an affected part of a patient's eye. FIG. 2 is a schematic view showing an opitical system of the apparatus.
[0023] Reference numeral 1 denotes a main body of the laser treatment apparatus. Reference numeral 2 is a control board for setting and inputting irradiation output conditions of the treatment beam. Reference numeral 3 denotes a slit lamp delivery comprising a laser irradiation optical system 30 , an illumination optical system 40 , and an observation optical system 50 . Reference numeral 4 is a fiber cable for delivering the treatment beam or an aiming laser light beam (hereinafter, merely referred to as an aiming beam) from the main body 1 to the slit lamp delivery 3 . Reference numeral 5 is a foot switch for generating a trigger signal to start Laser irradiation. Reference numeral 6 is a joystick for moving the slit lamp delivery 3 .
[0024] Reference numeral 7 denotes a switch for lighting LEDs 41 a - 41 c that constitute an illumination light source incorporated in the slit lamp delivery 3 . Reference numeral 8 denotes a light adjusting knob for adjusting an illumination light quantity. Reference numeral 9 is a cable connecting between the slit lamp delivery 3 and a control section 60 (see FIG. 3) on the side of the main body 1 . The cable 9 is used for transmitting and receiving a command signal to insert/remove a protective filter 57 with respect to an optical path of the observation optical system 50 (hereinafter, referred to as an observation optical path) or a detection signal indicating the insertion or removal of the filter 57 (i.e. the presence or absence of the filter 57 in the observation optical path). The cable 9 is also used to transmit whether the toot switch 5 is active or inactive to the slit lamp delivery 3 .
[0025] Reference numeral 10 denotes a laser source for emitting a treatment beam. In the present embodiment, as the laser source 10 , an Nd:YAG laser capable of oscillating a fundamental wave of 1064 nm is used to generate a green light of 532 nm (linearly polarized light), which is double the fundamental wave. Reference numeral 11 is a beam splitter having the property of transmitting most part of the treatment beam emitted from the laser source 10 while reflecting a part of the beam. The part of the treatment beam reflected by the beam splitter 11 enters an output sensor 13 through a diffusing plate 12 for detecting the output value of the treatment beam.
[0026] Reference numeral 14 is a safety shutter. When the foot switch 5 is depressed, issuing a command for laser irradiation (i.e. generating a trigger signal), the safety shutter 14 is removed from the optical path, thus enabling the passing of the treatment beam. In case where an abnormality occurs, the safety shutter 14 is inserted into the optical path to thereby intercept the laser beam. The opening and closing of this shutter 14 is detected by means of a shutter sensor 14 a.
[0027] Reference numeral 15 denotes a laser light source for emitting an aiming beam. In the present embodiment, there is used a semiconductor laser source capable of emitting a red aiming beam of 630 nm. The aiming beam emitted from the light source 15 passes through a collimator lens 16 and is made coaxial to the treatment beam by means of a dichroic mirror 17 .
[0028] Reference numeral 18 is a second safety shutter. The opening and closing of this shutter 18 is detected by a shutter sensor 18 a . Reference numeral 19 denotes a focusing lens for focusing the laser beams (the treatment beam and the aiming beam) to an incident end face 4 a to enter the fiber 4 . The laser beams are delivered through the fiber 4 to the irradiation optical system 30 of the slit lamp delivery 3 .
[0029] The irradiation optical system 30 comprises a collimator lens 31 , a variable magnification lens group 32 , an objective lens 33 , and a driving mirror 34 . An operator can operate a manipulator (not shown), whereby to change the reflection angle of the driving mirror 34 to fine adjust a laser irradiation position.
[0030] Reference numeral 40 denotes an illumination optical system. Reference numerals 41 a , 41 b , and 41 c each denote an LED used as an illumination light source. The LEDs 41 a - 41 c emit beams of illumination light in wavelength regions for red (R), green (t), and blue (B), respectively, that are the primary colors of light.
[0031] The wavelength characteristics of each of the LEDs 41 a , 41 b , and 41 c are shown in FIG. 4. The LED 41 a emits illumination light of the blue wavelength region of which a peak light emission wavelength is close to 460 nm, and the blue illumination light is allowed to pass through dichroic mirrors 80 and 81 disposed on an optical axis L. The LED 41 b emits illumination light of a green wavelength region of which a peak light emission wavelength is close to 520 nm. The green illumination light is reflected by the dichroic mirror 80 to be composed with the blue illumination light. Then, the resultant light is allowed to pass through the dichroic mirror 81 . The LED 41 c emits illumination light of a red wavelength region of which a peak light emission wavelength is close to 630 nm. The red illumination light is reflected by the dichroic mirror 81 to be composed with the beams of blue and green illumination light.
[0032] In the present embodiment, although the dichroic mirrors 80 and 81 are used to make the beams of illumination light (red, green, and blue light beams) coaxial to each other (composed with each other), the present invention is not limited to such dichroic mirror. A beam combining device such as half mirror, polarizing plate, or prism may be used.
[0033] The beams of visible illumination light emitted from the LEDs 41 a - 41 c and made coaxial (composed with each other) on the optical axis L are allowed to pass through a condenser lens 42 . A height and a width of the resultant light are determined by a variable circular aperture plate 43 and a variable slit plate 44 respectively to be formed into a slit-shaped luminous flux. Then, the slit-shaped illumination light is allowed to pass through a projection lens 46 and then reflected by dividing mirrors 48 a and 48 b toward the patient's eye E. The light thus illuminates the eye E through a contact lens 49 . Reference numeral 47 is a correction lens, and reference numeral 45 is a wavelength selection filter to be inserted into or removed from the optical path of the illumination optical system 40 (hereinafter, referred to as illumination optical path).
[0034] An observation optical system 50 comprises: an objective lens 51 shared between the left and right observation optical paths; a variable magnification lens 52 ; an image forming lens 53 ; an erect prism 54 ; a field diaphragm 55 ; eyepiece lenses 56 ; and the protective filter 57 ; the elements 53 - 57 being disposed in the left and right observation optical paths, respectively. FIG. 5 is a view showing wavelength transmission characteristics of the filter 57 . The filter 57 used in the present embodiment has the property of cutting 99% or more of light of a narrow bandwidth wavelength region (520 nm-540 nm), the center of which is 532 nm of the treatment beam, while allowing most of light of the visible wavelength region.
[0035] The filter 57 is arranged to be insertable into or removable from the observation optical path by means of a movement mechanism constructed of a motor or the like (not shown). The insertion and removal of the filter 57 with respect to the observation optical path is effected based on the presence or absence of the trigger signal from the foot switch 5 . The condition of the filter 57 , or the presence or absence of the filter 57 in the observation optical path, is detected by means of a sensor 57 a.
[0036] Operation of the apparatus constructed as above will be described with reference to a block diagram schematically showing a control system shown in FIG. 3.
[0037] An operator turns on the LEDs 41 a - 41 c by means of the switch 7 . At this time, the light quantity of each of the illumination light beams emitted from the LEDs 41 a - 41 c is controlled in advance by a light quantity control section 61 so that white illumination light is produced after three luminous fluxes (red, green, and blue) have been composed. To be more specific, the light quantities of the LEDs 41 a , 41 b , and 41 c are each controlled so that the light quantities have the following ratio; LED 41 a : LED 41 b : LED 41 c (B:G:R)=0.5:0.6:1.0.
[0038] As a result, the illumination light beams emitted from the LEDs 41 a - 41 c are changed into a substantially white illumination light after they are composed; the white illumination light illuminates the patient's eye E; and the operator can obtain an observation image (observation visual field) in close to a natural color. It in to be noted that the light quantity ratio is not limited to the above, another ratio may be adopted if only the color of the illumination light produced by composition is within a region of white light.
[0039] Even when the light quantity of illumination light projected to the patient's eye E is changed by using the light adjusting knob 8 , the light quantity is increased or decreased by the light quantity control section 61 without changing the ratio of the light emission quantities of the LEDs 41 a - 41 c . This makes it possible to maintain the illumination light after composed in a substantially white color.
[0040] Since the LED is used as the illumination light source in the present embodiment, heating quantity can be reduced, thus eliminating the need to consider a thermal effect caused by the illumination light from the LED. Such each LED has its long service life, and may not be frequently replaced.
[0041] The illumination light beams from the LEDs 41 a , 41 b , and 41 c are composed by the dichroic mirrors 80 and 81 , whereby substantially white illumination light is produced as described above, which illuminates the patient's eye E through the illumination optical system 40 . The operator can observe through the observation optical system 50 the fundus of the patient's eye E illuminated by the white illumination light.
[0042] Next, the aiming laser source 15 is lit by a switch (not shown) on the control board 2 . Upon setting of the emission of the aiming beam, the control section 60 causes the shutter 18 to be removed from the optical path.
[0043] The operator operates the joystick 6 and a manipulator (not shown) while observing the aiming beam irradiated to the eye fundus, and performs alignment with respect to an affected part of the eye fundus. The operator sets irradiation conditions such as the irradiation power or irradiation time of the treatment beam by using various switches on the control board 2 . When the laser irradiation is ready, a READY status is established such that the irradiation of the treatment beam is enabled. Then, the operator operates the manipulator (not shown) to make fine adjustment for alignment with the affected part. After completion of the alignment, the operator depresses the foot switch 5 to start the laser irradiation. Upon receipt of the trigger signal from the foot switch 5 , the control section 60 generates a command signal to insert the filter 57 into the observation optical path. The sensor 57 a detects that the filter 57 is inserted into the observation optical path and transmits the detection signal to the light quantity control section 61 .
[0044] Upon receipt of the detection signal from the sensor 57 a , the light quantity control section 61 changes the ratio of the light quantities of the LEDs 41 a - 41 c in synchronization with the insertion of the filter 57 into the observation optical path. A change quantity of this light quantity ratio is preset so that the light densities of R, G, and B that pass through the filter 57 are close to those obtained in the absence of the filter 57 in the observation optical path.
[0045] The above change of the light quantity ratio by the light quantity control section 61 is effected for the following reason.
[0046] That is, when the reflection light from the patient's eye E passes through the filter 57 , light of wavelengths in a range of 520 nm to 540 nm is cut by the filter 57 in order to cut the treatment beam. In association with this, the density of the green light is reduced. In this case, the ratio of the light quantities of the light beams passed through the filter 57 becomes the following relation; B:G:R=0.8:0.3:1.0. Consequently, the entire observation image obtained during observation through the filter 57 is more colorful (purplish) than that obtained in the absence of the filter 57 .
[0047] To compensate for the density of the green light cut by the filter 57 , the density of light of a green wavelength region which is allowed to pass through the filter 57 is relatively increased.
[0048] The ratio of respective light quantities of the LEDs 41 a - 41 c is changed, for example, by increasing the light quantity of LSD 41 b , while decreasing those of the LEDs 41 a and 41 c , so that the light quantity ratio of the light beams passed through the filter 57 is adjusted to the relation; B:G:R=0.5:0.6:1.0. In this case, the ratio of respective actual light quantities of the LEDs shows the following relation; LED 41 a : LED 41 b LED 41 c (B:G:R)= 0.3:1.0:0.9. In this manner, the colored degree of an observation image is lowered, and an observation image produced in the presence of the filter 57 in the observation optical path can be given the tone close to the observation image produced in the absence of the filter 57 therein.
[0049] Relative control of the light quantity ratio of the LEDs 41 a - 41 c may be experimentally determined so that the tones of the observation images in the presence and the absence of the filter 57 are as identical to each other as possible.
[0050] When confirmed the insertion of the filter 57 into the observation optical path through the sensor 57 a (when received the detection signal representative of the presence of the filter 57 from the sensor 57 a ), the control section 60 causes the shutter 14 to be removed from the optical path and the laser source 10 to emit the treatment beam. The treatment beam is delivered through the optical system in the main body 1 , the fiber 4 , and the irradiation optical system 30 , to irradiate the affected part of the patient's eye E.
[0051] Even if the filter 57 is inserted during laser irradiation, i.e., in the observation optical path, the observation image is obtained in a color state close to a natural color which is obtained during the observation in the absence of the filter 57 . Thus, the state of the affected part or treatment result can be observed without any strangeness. Further, even when the filter 57 is placed in the observation optical path for a long time for continuous laser irradiation, there is no need to remove the filter 57 in the middle of treatment because of a low visibility in order to allow the operator to check the treatment state without the filter 57 . The light quantity control mentioned above is therefore particularly effective for the continuous laser irradiation.
[0052] When the operator stops depressing the foot switch 5 , no trigger signal is generated therefrom. In response to no signal from the foot switch 5 , the control section 60 stops the laser emission from the laser source 10 and removes the filter 57 from the observation optical path. In association with the detection signal from the sensor 57 a that has detected the removal of the filter 57 , the light quantity control section 61 resets the light quantity ratio of the LEDs 41 a - 41 c to the original light quantity ratio used before the insertion of the filter 57 . In this manner, even after the filter 57 is removed from the observation optical path, there can be obtained an observation image with substantially the same tone as that obtained before the insertion of the filter 57 into the observation optical path.
[0053] The present invention may be embodied in other specific forms without departing from the essential characteristics thereof.
[0054] For instance, in the above embodiment, the light quantity ratio of the LEDs 4 l a - 41 c is changed in association with the detection signal from the sensor 57 a representing the presence/absence of the filter 57 in the observation optical path. Alternatively, the ratio may be changed in response to the trigger signal from the foot switch 5 .
[0055] The above embodiment has described an example of using three types of LEDs for emitting beams of illumination light of wavelengths in regions for R, G, and B. However, if those three types of LEDs are insufficient to produce a substantially white illumination light, the types of LEDs for emitting beams of illumination light of wavelengths in different regions from the above three regions may be further increased so that the substantially white illumination light is easily obtained. In the case where the illumination light quantity is insufficient, the number of LEDs may be increased for each color.
[0056] Furthermore, although the present embodiment describes an example of a laser treatment apparatus, the present invention is, of course, applicable to only a slit lamp. In this case, there is conveniently provided selection keys 70 a , 70 b , and 70 c for selectively lighting the LEDs 41 a , 41 b , and 41 c for B, G, and R light or individually adjusting the light quantity of each of the 41 a - 41 c (see FIG. 6). For example, in the fluorescent observation using fluorescein eyewash, the LED 41 a is lit so that the patient's eye E is illuminated by blue illumination light capable of exciting fluorescein.
[0057] In the observation of blood vessels of conjunctiva or the like, the LED 41 b for emitting green illumination light is lit without illumination by red illumination light, thereby facilitating the observation. This makes it also possible to eliminate a filter mechanism for selecting wavelengths from the illumination optical system 40 . In such a case, an LED for emitting light of wavelengths required for the fluorescence observation or the like may be provided in advance as an LED for an illumination light source.
[0058] Alternatively, the light quantity of red illumination light may be reduced or the light quantity of green illumination light or blue illumination light may be increased in order to finely adjust the illumination light to an easy-to-observe color according to the color of an observation site.
[0059] The lighting of the LEDs 41 a - 41 c or the light quantity control is effected by the light quantity control section 61 connected to the selection keys 70 a - 70 c . In the case where the entire illumination light quantity is controlled without changing the light quantity ratio of the colors, the knob 8 is used. Alternatively, an LED for emitting illumination light of wavelengths according to types of the fluorescence observation or the like may be provided separately from the LED for an illumination light source.
[0060] Furthermore, even if only one type of a white-emitting LED is used without use of three types (R, G, and B) of LEDs, the use of such white-emitting LED is very effective in heat generation and service life in comparison with a conventional halogen lamp or tungsten lamp.
[0061] As has been described above, according to the present invention, the apparatus with an illumination light source which is easy-to-handle and a simplified configuration can be achieved. Furthermore, in the laser treatment, the affected part of the patient's eye can be easily observed even in the presence of the protective filter in the optical path of the observation optical system. | An opthalmic apparatus includes an illumination optical system for illuminating an eye of a patient, the illumination optical system including a plurality of LEDs which are illumination light sources for emitting beams of light of wavelengths in different regions and a composing optical system for composing optical paths of the beams of light emitted from the LEDs, an observation optical system for observing the patient's eye, and a light quantity control section capable of controlling an illumination light quantity of each of the LEDs to produce substantially white illumination light. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates in general to the field of vehicles, and more particularly to vehicles equipped with impact detectors. Still more particularly, the present invention relates to a video recording device for unattended vehicles that have been struck by another vehicle.
[0003] 2. Description of the Related Art
[0004] It is a common occurrence for vehicles to be damaged while parked in a public parking lot. That is, an unattended parked vehicle is often struck by another vehicle, shopping cart, person, etc., which/who then leaves the accident scene without acknowledging responsibility for the impact. The owner of the vehicle is therefore left with no recourse against the guilty party.
SUMMARY OF THE INVENTION
[0005] In order to enable an owner of an unattended parked vehicle to identify a party that struck the owner's unattended parked vehicle, the present invention provides for a method, system and computer-readable medium for integrating operation of an on-board recorder with one or more vehicle-mounted cameras. Whenever an impact of sufficient strength is detected by an impact detector on a vehicle, feed from one or more vehicle-mounted cameras, which have a field of view that encompasses the striking vehicle, is sent to the on-board video recorder. The feed can also be sent to a remote receiver, such as a computer, a Personal Digital Assistant (PDA), a video-enabled cell phone, or a law enforcement monitor.
[0006] The above, as well as additional purposes, features, and advantages of the present invention will become apparent in the following detailed written description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] 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 purposes 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, where:
[0008] FIGS. 1A-B depict a vehicle with one or more vehicle-mounted external camera whose fields of view are directed to various areas proximate to the vehicle;
[0009] FIG. 2 illustrates additional detail for an Impact Camera System (ICS);
[0010] FIG. 3 illustrates an exemplary on-board computer in which the present invention may be utilized; and
[0011] FIG. 4 is a flow-chart of exemplary steps taken by the present invention to visually record an impact to the vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] With reference now to the figures and in particular to FIGS. 1A-B , a vehicle 100 is presented. Note that while vehicle 100 is presented for exemplary purposes, and as a preferred embodiment, as an automobile, vehicle 100 may be any vehicle, including but not limited to trucks, buses, aircraft, water craft, construction equipment (e.g., forklifts, graders, etc.), agricultural equipment (e.g., tractors, combines, etc.), and any other vehicle capable of transporting passengers and/or material, and/or performing work during vehicle movement.
[0013] Vehicle 100 includes multiple vehicle-mounted cameras 102 a - e. As depicted for exemplary purposes, vehicle-mounted cameras 102 a - d have slightly overlapping directional fields of view, while vehicle-mounted camera 102 e has a 360° field of view. Optionally, each vehicle-mounted camera 102 is also equipped with an audio microphone (not shown). Also located on vehicle 100 are an impact detection logic 104 , an on-board computer 302 , a camera feed logic 106 , and an on-board video recorder 310 , which together make up part of an Impact Camera System.
[0014] With reference now to FIG. 2 , an exemplary Impact Camera System (ICS) 200 is depicted. In response to vehicle 100 being impacted with a force that is above a pre-determined level, impact detection logic 104 sends an impact detection signal to on-board computer 302 . The pre-determined level is defined as an impact level of force that can be caused only by a moving object having a momentum that is equal to or greater than that caused by a motorized passenger vehicle, such as an automobile (but not a light motorcycle, etc.). Alternatively, the pre-determined level is defined as a lesser impact level of force caused by a shopping cart, motorcycle, etc. Thus, in either embodiment, an impact caused by a pedestrian, a thief breaking a window or door on the vehicle, a light baby carriage, etc., will not be sufficient to cause impact detection logic 104 to send the impact detection signal to the on-board computer 302 . In a preferred embodiment, impact detection logic 104 is not only able to detect an impact force that exceeds the pre-determined level, but is also able to determine a direction, from which the impact force originated, through the use of an optional momentum detection logic 107 that has an ability to determine the direction from which the impact came. This direction detection may be accomplished by any means known to those skilled in the art, including but not limited to, a three-axis weighted strain gauge, an inertia detector, etc. In an alternative embodiment, a parked/motion logic 109 is able to detect that the vehicle is parked (not moving) and that the vehicle has been struck. Thus, if the vehicle is not moving, then a simple motion logic, such as a contact switch on a leaf or coil spring in the vehicle's suspension, can trigger a recording of a camera feed. By knowing that the vehicle is parked, then this contact switch can be assumed to be closed in response to a vehicle blow, rather than a pothole, bump, etc. that would close the contact during travel operations of the vehicle.
[0015] Once the on-board computer 302 receives the impact detection signal from the impact detection logic 104 , and assuming that the impact detection logic 104 includes the momentum detection logic 107 , then the on-board computer 302 sends a view selection signal to the camera feed logic 106 . Coming into camera feed logic 106 are multiple video (and optionally audio) feeds from different vehicle-mounted cameras 102 . Based on the direction from which the impact came, feed from that camera will be selected by the camera feed logic 106 for recording by on-board video recorder 310 . For example, assume that another vehicle hit the front of vehicle 100 shown in FIG. 1A . In this example, feed from vehicle-mounted camera 102 b would be selected, since vehicle-mounted camera 102 b would have a field of view most likely to “see” the other vehicle. Alternatively, a feed from vehicle-mounted camera 102 e may be selected, either as an alternative to the feed from vehicle-mounted camera 102 b or as a supplemental feed to provide additional video information.
[0016] With reference now to FIG. 3 , there is depicted a block diagram of an exemplary on-board computer 302 , in which the present invention may be utilized. On-board computer 302 includes a processor unit 304 that is coupled to a system bus 306 . A video adapter 308 , which drives/supports a on-board video recorder 310 , is also coupled to system bus 306 . System bus 306 is coupled via a bus bridge 312 to an Input/Output (I/O) bus 314 . An I/O interface 316 is coupled to I/O bus 314 . I/O interface 316 affords communication with various I/O devices, including a keyboard 318 , a mouse 320 , a Compact Disk—Read Only Memory (CD-ROM) drive 322 , a floppy disk drive 324 , and a flash drive memory 326 . The format of the ports connected to I/O interface 316 may be any known to those skilled in the art of computer architecture, including but not limited to Universal Serial Bus (USB) ports.
[0017] On-board computer 302 is able to communicate with a remote video receiver 350 via a wireless network 328 using a wireless network interface 330 , which is coupled to system bus 306 . Wireless network 328 may be any wireless network, including a cell phone based system, a satellite communication system, etc. Note the remote video receiver 350 , which may be a computer, a cell phone, logic at a law enforcement office, etc., may utilize a same or substantially similar architecture as on-board computer 302 .
[0018] A hard drive interface 332 is also coupled to system bus 306 . Hard drive interface 332 interfaces with a hard drive 334 . In a preferred embodiment, hard drive 334 populates a system memory 336 , which is also coupled to system bus 306 . System memory is defined as a lowest level of volatile memory in on-board computer 302 . This volatile memory includes additional higher levels of volatile memory (not shown), including, but not limited to, cache memory, registers and buffers. Data that populates system memory 336 includes on-board computer 302 's operating system (OS) 338 and application programs 344 .
[0019] OS 338 includes a shell 340 , for providing transparent user access to resources such as application programs 344 . Generally, shell 340 is a program that provides an interpreter and an interface between the user and the operating system. More specifically, shell 340 executes commands that are entered into a command line user interface or from a file. Thus, shell 340 (as it is called in UNIX®), also called a command processor in Windows®, is generally the highest level of the operating system software hierarchy and serves as a command interpreter. The shell provides a system prompt, interprets commands entered by keyboard, mouse, or other user input media, and sends the interpreted command(s) to the appropriate lower levels of the operating system (e.g., a kernel 342 ) for processing. Note that while shell 340 is a text-based, line-oriented user interface, the present invention will equally well support other user interface modes, such as graphical, voice, gestural, etc.
[0020] As depicted, OS 338 also includes kernel 342 , which includes lower levels of functionality for OS 338 , including providing essential services required by other parts of OS 338 and application programs 344 , including memory management, process and task management, disk management, and mouse and keyboard management.
[0021] Application programs 344 include a browser 346 . Browser 346 includes program modules and instructions enabling a World Wide Web (WWW) client (i.e., on-board computer 302 ) to send and receive network messages to the Internet using HyperText Transfer Protocol (HTTP) messaging, thus enabling communication with wireless Internet Service Providers (ISPs), etc. (not shown).
[0022] Application programs 344 in on-board computer 302 's system memory also include an Impact-Camera Integration Program (ICIP) 348 . ICIP 348 includes code for implementing the processes described in FIGS. 2 and 4 .
[0023] The hardware elements depicted in on-board computer 302 are not intended to be exhaustive, but rather are representative to highlight essential components required by the present invention. For instance, on-board computer 302 may include alternate memory storage devices such as magnetic cassettes, Digital Versatile Disks (DVDs), Bernoulli cartridges, and the like. These and other variations are intended to be within the spirit and scope of the present invention.
[0024] With reference now to FIG. 4 , a high-level flow-chart of exemplary steps taken by the present invention is presented. After initiator block 402 , a query is made to determine if a the impact detection logic in the vehicle has detected an impact of a force that is above a pre-determined level (query block 404 ). This pre-determined level may be reached by the vehicle 100 (shown in FIG. 1A ) being hit by another vehicle, either while vehicle 100 is parked, or alternatively, while vehicle 100 is moving. If so, then a video feed selection logic (e.g., camera feed logic 106 shown in FIG. 2 ) selects a video feed from an appropriate (left, right, front, rear, omnidirectional) camera, based on the direction from which the impact was delivered, and sends the selected video feed to the on-board camera for recording (block 406 ). Feed from the camera is recorded for any pre-determined period of time, ranging from a few seconds (if the on-board recorder is able to record only a limited amount of MPEG data) to an unlimited amount of time. The process thus ends at terminator block 408 .
[0025] With reference again to query block 404 , in an alternate embodiment, a video feed selection logic selects an appropriate video feed if a collision is determined to be imminent. This determination may be made by a speed/proximity combination logic, known to those skilled in the art, which determines that an impact is imminent based on the speed of an approaching object. By spooling up the video feed before the impact, relevant forensic evidence can be gathered by the vehicle-mounted cameras, such as the license plate of the other vehicle, road conditions, time of day, etc.
[0026] It should be understood that at least some aspects of the present invention may alternatively be implemented in a computer-useable medium that contains a program product. Programs defining functions on the present invention can be delivered to a data storage system or a computer system via a variety of signal-bearing media, which include, without limitation, non-writable storage media (e.g., CD-ROM), writable storage media (e.g., hard disk drive, read/write CD ROM, optical media), and communication media, such as computer and telephone networks including Ethernet, the Internet, wireless networks, and like network systems. It should be understood, therefore, that such signal-bearing media when carrying or encoding computer readable instructions that direct method functions in the present invention, represent alternative embodiments of the present invention. Further, it is understood that the present invention may be implemented by a system having means in the form of hardware, software, or a combination of software and hardware as described herein or their equivalent.
[0027] The present invention thus presents a new and useful method, vehicle, system, and computer-readable medium for recording an impact to a vehicle. In a preferred embodiment, the method includes the steps of: detecting an impact to the vehicle; and in response to detecting the impact to the vehicle, recording a video feed from a vehicle-mounted camera, wherein the vehicle-mounted camera has a field of view that captures a source of the impact. Preferably, the impact has a force that exceeds a pre-determined level, such as that caused by another vehicle. The method may further include the step of recording an audio record of the impact. In one embodiment, the video feed is created by activating, from a plurality of vehicle-mounted cameras, a specific vehicle-mounted camera that has the field of view of captures the source of the impact, wherein the specific vehicle-mounted camera is chosen according to a direction from which the impact hit the vehicle. The video feed may be from a single omnidirectional vehicle-mounted camera. The vehicle may be any type of vehicle, including a transportation vehicle.
[0028] More specifically, the vehicle may include an impact detection logic that selectively detects an impact to the first vehicle, wherein the impact is determined by the impact detection mechanism to be of sufficient force to have been caused by an other vehicle traveling at a sufficient velocity to damage the first vehicle; at least one vehicle-mounted camera, wherein the at least one vehicle-mounted camera captures an image of the other vehicle in response to the impact detection mechanism selectively detecting the impact to the first vehicle; a momentum detection logic, wherein the momentum detection logic detects a direction from which the impact originated; a camera feed logic, wherein the camera feed logic selects a video feed from a plurality of vehicle-mounted cameras according to the direction from which the impact originated; an on-board video recorder for recording the image of the other vehicle; and a transmission means for transmitting the image of the other vehicle to a remote video receiver. The image of the other vehicle may be a moving video image.
[0029] The inventive system, which may installed in any land, air, or water based transportation vehicle, as well as non-transportation equipment, may include an impact detection logic; an impact detection mechanism that selectively detects an impact to the first vehicle, wherein the impact is determined by the impact detection mechanism to be of sufficient force to have been caused by an other vehicle traveling at a sufficient velocity to damage the first vehicle; at least one vehicle-mounted camera, wherein the at least one vehicle-mounted camera captures an image of the other vehicle in response to the impact detection mechanism selectively detecting the impact to the first vehicle; a momentum detection logic, wherein the momentum detection logic detects a direction from which the impact originated; a camera feed logic, wherein the camera feed logic selects a video feed from a plurality of vehicle-mounted cameras according to the direction from which the impact originated; a transmission means for transmitting the image of the other vehicle to a remote video receiver; and an on-board video recorder for recording the image of the other vehicle.
[0030] While the present invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. Furthermore, as used in the specification and the appended claims, the term “computer” or “system” or “computer system” or “computing device” includes any data processing system including, but not limited to, personal computers, servers, workstations, network computers, main frame computers, routers, switches, Personal Digital Assistants (PDA's), telephones, and any other system capable of processing, transmitting, receiving, capturing and/or storing data. | In order to enable an owner of an unattended parked vehicle to identify a party that struck the owner's unattended parked vehicle, the present invention provides for a method, system and computer-readable medium for integrating operation of an on-board recorder with one or more vehicle-mounted cameras. Whenever an impact of sufficient strength is detected by an impact detector on a vehicle, feed from one or more vehicle-mounted cameras, which have a field of view that encompasses the striking vehicle, is sent to the on-board video recorder. The feed can also be sent to a remote receiver, such as a computer, a Personal Digital Assistant (PDA), a video-enabled cell phone, or a law enforcement monitor. | 1 |
BACKGROUND OF THE INVENTION
[0001] This invention concerns tissue or cell culture chambers such as incubators and similar chambers in which open culture vessels, i.e., culture dishes, are provided with a controlled environment, and is more particularly concerned with techniques for controlling the atmospheric parameters inside the incubation chamber, such as the concentration of a gas. The invention is more specifically directed to techniques for creating dynamic instead of static atmospheric conditions inside cell culture incubators for the purposes of achieving better growth, or achieving better viability over longer periods of time with or without growth, or achieving better simulation in vitro (in the dish) of those natural conditions that occur in vivo (in the body), including both normal and pathologic conditions.
[0002] Cells and tissue taken from a multi-cellular organism, for example, can be cultured outside the body in various liquid and semi-liquid media contained in culture vessels (in vitro) by simulating as closely as possible the environment to which these cells would normally be exposed while inside the body (in vivo). Many physical, chemical, and biological variables make up this critical environment. Generally, as long as all the essential variables remain within some physiologic range, cells and tissue in vitro will grow and differentiate and remain viable.
[0003] Since different cell types and different culture preparations of the same cell type have different requirements, the first step in the advancement of cell culture technology is to discover the entire set of essential variables for the given culture. The next step is to determine the optimum levels for each variable at every point in time over the course of that culture. Once these are accomplished, the final challenge is to simultaneously maintain each and every essential variable at or near its optimum level, at or near the proper time in the course of the culture, over the entire duration of the culture.
[0004] Oxygen concentration is one of the most universally important variables. Oxygen is the main electron sink driving respiration. Oxygen is also a critical substrate in many enzymatic oxygenation and oxidation reactions. For these reasons, oxygen must be maintained at sufficiently high levels in the media bathing the cells for the cells to function properly.
[0005] On the other hand, oxygen is also a concentration dependent toxin. It spontaneously breaks down and is metabolically broken down into free radicals and other highly reactive moieties, which are so unstable that they react indiscriminately with and damage whatever molecular structures happen to be nearby. For this reason, oxygen must be maintained at sufficiently low levels, so that the toxic byproducts of oxygen are not formed at a rate which will overwhelm the normal cellular antioxidant defense mechanisms.
[0006] Cell cultures are dynamic living entities that grow and evolve, and their metabolic activity changes over time. For one example, the oxygen consumption rate of a rapidly growing cell population in culture rises over time as the population size and density increases. Cell culture technologies that directly control oxygen in the culture vessel, such as bio-reactors, have the ability to respond to changes in oxygen demand. In response to an increase in oxygen demand, a direct control system will increase the oxygen supply rate to the culture in order to keep the oxygen concentration in the media from becoming dangerously low. Or it can change in the other direction: Overall oxygen consumption rate can decrease over time in culture, for instance, as a non-growing cell population differentiates from a high metabolic state to a more dormant state. Again, with direct control of oxygen in the culture vessel, the response would be to decrease the oxygen supply rate in order to keep the oxygen concentration in the media from becoming dangerously high. One example, among many others, of a direct oxygen control culture system is described in Pippen et al. U.S. Pat. No. 3,772,176.
[0007] However, many cells and tissues are cultured in culture vessels in which there is no direct control of oxygen. Instead the culture vessels are kept open and are placed inside controlled atmosphere chambers, typically called incubators, which create and contain a certain gas oxygen concentration considered to be at least sufficient if not optimal (in addition to a few other variables such as temperature, carbon dioxide concentration, and relative humidity). Oxygen is thereby indirectly controlled inside the culture vessel only as a result of the culture vessel being open with and contiguous to the common gas oxygen atmosphere inside the incubator. In some incubators oxygen is actively controlled at some specific level, and in other incubators it is not. With no control, oxygen is always fixed at just under the ambient air oxygen level. In any case, the typical objective of such incubators is to maintain the gas oxygen concentration constant throughout the incubator and constant over the time required for the cultivation of the culture. One example of a current state of the art controlled atmosphere cell culture incubator is described in Hugh et al. U.S. Pat. No. 5,792,427.
[0008] In any open culture vessel within such controlled atmosphere incubators, oxygen can only be supplied to the cells in the liquid media by diffusion of oxygen into the liquid phase from that part of the gas phase which is in contact with the liquid. If the oxygen concentration in the gas phase is constant, that means the oxygen supply rate is fixed. With a fixed oxygen supply rate and with no ability to respond to changes in oxygen demand in any of the culture vessels placed within them, common laboratory cell culture incubators with static oxygen atmospheres are severely limited in their ability to keep oxygen at optimum levels for very long over the course of any given culture. For example, once the oxygen demand rate exceeds the fixed supply rate in a culture with a rapidly increasing cell population density, the culture will not be able to get enough oxygen and can die of oxygen starvation.
[0009] Consequently, to keep rapidly growing cultures alive over long periods, one common procedure is to keep the cell population density within a certain range which is compatible with the fixed oxygen supply rate afforded by the incubator oxygen tension. This is carried out by routine subculture, before the cell population density reaches a dangerously high level that would lead to oxygen deprivation. Such a procedure involves considerable labor and materials, may increase chance of contamination, and limits the range of different culture preparations that can be grown.
[0010] However, since current incubator technology with static oxygen does not otherwise recognize that oxygen requirements change over time, there are only two other options when using current state of the art incubators. One option is to change the oxygen concentration in the incubator manually at appropriate times. The other is to maintain multiple incubators with different oxygen tensions and physically move the open culture vessels from incubator to incubator at the appropriate times. Both these options assume the incubators have oxygen control, and of course, many do not. Obviously, in incubators without oxygen control, neither option is available. Yet, even with those incubators that do have the ability to control oxygen, both options are inherently difficult to carry out. Manually changing the oxygen level in an incubator requires rigorous scheduling, which is both inconvenient and subject to human error. Moving cultures among multiple incubators has the same problems. In addition, physically handling the cultures increases chance of contamination, and also requires a considerable investment in equipment and space for all the incubators that would be needed.
[0011] Outside of incubators, the only other common way to control the atmosphere of open dish cultures is to place them inside a sealable container, and then flush the container with a prepared gas mixture to condition the gas phase. Once conditioned, the containers are sealed and placed in a temperature controlled chamber. It would be possible to dynamically change the oxygen concentration over the course of a culture by the use of numerous gas mixtures with different oxygen levels, and flush each appropriate mixture at the appropriate time. Yet this method is fraught with even more difficulty. It presents all the same problems of the aforementioned manual incubator procedures, but requires even more labor.
[0012] Moreover, none of these current options provide a definitive method for determining what the optimum gas oxygen levels are for different open dish culture preparations over the entire course of their culture period.
[0013] In view of the above noted problems and deficiencies of current controlled atmosphere incubators with static oxygen levels, there is a need for incubators and culture chambers for the culture of cells and tissue in open culture vessels in which the gaseous oxygen concentration is deliberately and automatically changed over time in a precise and reproducible way. Additionally, there is a need for apparatus and a technique for determining the optimal gas oxygen levels and timing that will be required for any given open dish culture preparation.
OBJECTS AND SUMMARY OF THE INVENTION
[0014] Accordingly, it is an object of the present invention to provide an incubator or controlled atmosphere chamber for open dish cultures which, instead of being limited with static controlled conditions, can carry out precise and deliberate automated changes in gas phase oxygen concentration. It will be able to change oxygen concentration while holding all other controlled parameters constant, or while one or more other controlled parameters are changed simultaneously or sequentially as well.
[0015] Another object is to control the atmosphere in an incubator for a cell and tissue culture in which the gaseous oxygen concentration is deliberately changed over time in a precise and reproducible way, while all the other parameters are held constant, or while one or more other controlled parameters are changed simultaneously or sequentially.
[0016] A related object is to determine the specific sequence and timing of changes in the gaseous oxygen concentration that will best indirectly regulate the desired dissolved oxygen concentration in the culture media inside open culture vessels that are placed inside the incubator.
[0017] Moreover, it is an object to employ specific gas oxygen profiles in such chambers for the purpose of achieving better growth over longer periods of time, or achieving better viability with or without growth over longer periods of time, or achieving better simulation in vitro (in the dish) of conditions that occur naturally in vivo (in the body) in the open dish cultures that are incubated in such chambers. That is, it is not only on object to create conditions of growth of healthy tissue, but in many cases it is desired to simulate cell pathologies. Gas oxygen profiles are defined here as a linear sequence of time segments of different or similar duration, each with different or similar gas oxygen concentration setpoints which can be controlled sequentially once, or cycled a defined number of times, or cycled continuously. Dissolved oxygen profiles, in contrast, are a linear sequence of timed dissolved oxygen setpoints.
[0018] It is another object of the invention to provide methodology for determining a specific gas oxygen profile in the culture chamber that will best indirectly regulate the desired dissolved oxygen concentration in the culture media inside the open culture vessels which contain certain cell or tissue culture preparations that are to be cultured inside the chamber.
[0019] In all embodiments of the invention, a servo control loop regulates the oxygen concentration. This oxygen control loop may be designed to work alone in some embodiments. In others, it may be designed to work in conjunction with one or more additional control loops used to control other variables in the same chamber, such as temperature or carbon dioxide. The oxygen control loop may be designed to control oxygen directly in the culture chamber, or indirectly in a secondary gas mixing apparatus and then circulate oxygen controlled gas to the culture chamber.
[0020] In typical servo fashion, this oxygen control loop utilizes the input or feedback from an oxygen sensor to activate one or more appropriate outputs in order to reduce towards zero the difference between the oxygen sensor reading and the oxygen setpoint. Setpoints are defined here as the oxygen concentration desired by the operator. They can be gas oxygen setpoints or dissolved oxygen setpoints. Setpoints can be entered manually one at a time by the operator, or a series of setpoints can be provided to the control loop automatically at times as specified by an oxygen profile. The outputs consist of one or more actuators of any suitable type that can increase the gas oxygen concentration in the chamber, and others that can decrease the gas oxygen concentration in the chamber. However, the input or feedback to this control loop can be provided by either a gas oxygen sensor or a dissolved oxygen sensor. Gas oxygen sensors monitor the oxygen concentration in the gas phase inside the incubation chamber, and can be of any suitable type. Gas sensors provide feedback to control gas setpoints. Dissolved oxygen sensors monitor the oxygen concentration in the liquid media contained in one or more of the open culture vessels incubating inside the chamber, and can be of any suitable type compatible with such culture vessels. Dissolved oxygen sensors serve as feedback to control dissolved oxygen setpoints in the liquid.
[0021] The invention contemplates several different embodiments and several different methods of operation depending on the particular needs of the operator and various limitations. Those limitations may be imposed by economic constraints, imposed by specific requirements of certain culture preparations, or imposed by the particular technology used to monitor the dissolved oxygen concentration in individual culture vessels.
[0022] Some embodiments may require only a gas oxygen sensor and may not need a dissolved oxygen sensor at all. If the gas oxygen profile is known, or if it is possible to empirically determine a suitable gas oxygen profile, it may be more economical and practical to employ in some culture chambers only a gas oxygen sensor to provide the feedback to the oxygen control loop. For example, just by knowing that the oxygen demand increases over time in a rapidly growing culture, it may be possible to achieve a substantial improvement over an incubator with a static oxygen level by simply controlling a gas oxygen profile that starts out at a low oxygen level and gradually increases the oxygen level over the duration of the culture.
[0023] Other embodiments may require only a dissolved oxygen sensor and may not need a gas oxygen sensor. Whenever the particular technology utilized for sensing the dissolved oxygen concentration is not disruptive in any significant way to the culture in which it is measuring the oxygen, it should be possible to directly control the oxygen concentration in the media inside the open culture vessel at any single dissolved oxygen setpoint or series of setpoints in a profile, with no particular need for a gas oxygen sensor at all. For example, it may be desirable to keep the dissolved oxygen tension constant at some hypoxic, normoxic, or hyperoxic level in a rapidly growing culture. With a fixed dissolved oxygen setpoint, the gas oxygen level would be adjusted higher and higher over the course of such a culture in order to keep up with increased It oxygen demand and thereby maintain a constant oxygen tension in the media. Such direct control of the dissolved oxygen tension could compensate in real time for variations in demand is over the course of the culture, and variations in demand among different culture preparations. In this regard it should be possible to achieve a substantial improvement over a static oxygen level incubator by letting the oxygen control loop blindly profile oxygen in the gas phase.
[0024] In circumstances where the process of sensing the dissolved oxygen concentration in the liquid media may be disruptive or potentially disruptive, it will be necessary to use a surrogate culture that is prepared to be similar to the culture of interest, or an identical sample of the same culture preparation which is expendable. Direct control of the dissolved oxygen in such a witness dish creates the gas oxygen profile which is optimal for the separate undisturbed neighboring culture of interest.
[0025] In one preferred embodiment at least one dissolved oxygen sensor and one gas oxygen sensor are utilized simultaneously in the same culture chamber. A primary aspect of this embodiment of the invention is that either the gas oxygen sensor or the liquid oxygen sensor can provide the input or feedback to the oxygen servo control loop. Furthermore, it will be possible to switch back and forth between the two at the beginning of each new culture, or at any point in time over the course of a culture. Switching can be done manually or automatically. Regardless of which type of oxygen sensor is serving as the input to the control loop, the oxygen readings from both types of sensors are continuously monitored and recorded, and preferably but not necessarily displayed in real time. Setpoints are differentiated as either dissolved oxygen setpoints or gas oxygen setpoints. Of course, such a dual sensor embodiment could be operated in either of the other single sensor modes described just above.
[0026] The invention further contemplates that simultaneous dissolved oxygen and gas oxygen sensing with switchable feedback provides the unique ability to determine the specific gas oxygen profile in the chamber that will best indirectly regulate the desired dissolved oxygen concentration in any given culture preparation. The procedure would first entail utilizing the dissolved oxygen sensor as the input to the oxygen control loop and directly controlling the oxygen concentration in the liquid media. As dissolved oxygen setpoints are controlled, the gas oxygen levels that result are recorded as a function of time. These gas oxygen levels are then converted to gas oxygen setpoints in a gas oxygen profile, which can then be recreated anytime. Recreating the same dynamic atmosphere over identical culture preparations will indirectly regulate the same dissolved oxygen concentrations. This can be verified in the same chamber by switching to the gas oxygen sensor for feedback to the loop, and controlling that same recorded gas oxygen profile during the repeat incubation of an identical culture preparation while monitoring the dissolved oxygen.
[0027] In an alternative method, the dissolved oxygen measurements are simply recorded over the time that a specific gas oxygen profile is controlled in the incubator. This allows an empirical approach to the optimization of a profile by testing different gas profiles and ascertaining how close each different profile comes to achieving the desired levels of dissolved oxygen.
[0028] Determination of the proper gas profile may be routine procedure for each new culture preparation so that subsequently it may be successfully cultured in chambers without dissolved oxygen sensors. It may be required for certain culture preparations in which the process of sensing the dissolved oxygen concentration is disruptive or potentially disruptive.
[0029] Oxygen profiling is a primary importance, but other embodiments could include profiling of other bio-active gases, such as CO 2 , CO, NO, Et, CH 4 , NH 3 , etc., and/or profiling of temperature, although temperature profiling is common in other applications. The tissue or cells may be human, other animal, plant, or microbial.
[0030] The above and many other objects, features, and advantages of this invention will be more fully appreciated from the ensuing description of preferred embodiments, which is to be read in conjunction with the accompanying Drawing.
BRIEF DESCRIPTION OF DRAWING
[0031] [0031]FIG. 1 is a functional schematic of a culture chamber and all associated components for carrying out the processes common to all different physical embodiments of this invention.
[0032] [0032]FIG. 2 is a schematic illustrating one physical embodiment described as a retrofit embodiment.
[0033] [0033]FIG. 3 is a schematic illustrating another physical embodiment described as a sub-chamber embodiment.
[0034] [0034]FIG. 4 is a schematic illustrating another physical embodiment described as a remote conditioning embodiment.
[0035] [0035]FIG. 5 is a schematic illustrating another physical embodiment described as an integrated stand-alone single chamber incubator embodiment.
[0036] [0036]FIG. 6 is a schematic illustrating another physical embodiment described as an integrated stand-alone multi-chamber incubator embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0037] With reference now to the Drawing, FIG. 1 is a block diagram and schematic of the functional components of the invention common to various physical embodiments as depicted in FIGS. 2 - 6 . An oxygen profile controller 16 controls gas oxygen tension inside each of one or more culture chambers 36 which contains the cell or tissue cultures in open culture vessels 32 and 33 . The culture chamber 36 may be a stand-alone chamber such as any commercially available incubator 10 as depicted in FIG. 2, or an integrated single chamber incubator 110 as depicted in FIG. 5, or an integrated multiple chamber incubator 210 as depicted in FIG. 6. Alternatively, the culture chamber 36 may be a sub-chamber inside another host chamber 360 as depicted in FIGS. 3 and 4, and multiple culture chambers 36 and 38 can be sub-chambers inside the same or different host chambers 360 .
[0038] In all embodiments the controller 16 controls oxygen via an oxygen servo control loop 160 in each culture chamber 36 according to feedback from either a gas oxygen sensor 12 monitoring gas oxygen tension 120 , or a liquid oxygen sensor 28 , 30 monitoring dissolved oxygen tension 280 in the culture media contained in at least one witness culture vessel 32 in that culture chamber 36 . The dissolved oxygen 280 in a witness dish 32 will be representative of the dissolved oxygen in all other non-monitored culture vessels 33 of the same culture preparation since their oxygen is supplied from the same common gas oxygen tension 120 . The dissolved oxygen sensor may be an invasive sensor 28 or a non-invasive sensor 30 . An invasive oxygen sensor 28 is one that is immersed into the culture media, such as an electrochemical oxygen sensor. A non-invasive oxygen sensor 30 is one that measures from outside the culture vessel 32 , such as an optical oxygen sensor. Depending on economic and technical constraints and needs of the operator, the oxygen servo control loop 160 in some culture chambers 36 will require only a gas oxygen sensor 12 , some will require only a dissolved oxygen sensor 28 or 30 , and some will require both. Those configured with both gas oxygen and dissolved oxygen sensors will have a switch 17 that will allow the operator to select which sensor is to provide the feedback to the oxygen control loop 160 .
[0039] The controller 16 can actuate control of the oxygen level via the oxygen servo control loop 160 in each culture chamber 36 most simply by the infusion of gases 26 from continuous supplies of those gases 20 in order to displace by dilution the previous atmosphere. Oxygen or oxygen-enriched gas can be infused to raise the oxygen level. Oxygen free gas such as nitrogen or oxygen-depleted gas can be infused to lower the oxygen level. However, any other suitable method of changing the oxygen level, such as generating or scrubbing oxygen may be utilized as well. Regardless of whether a gas oxygen sensor 12 or a dissolved oxygen sensor 28 or 30 is providing the feedback to the oxygen control loop 160 , the actuation of oxygen control is the same, that is, the raising or lowering of the chamber gas oxygen tension 120 .
[0040] Oxygen control setpoints are designated as either gas oxygen setpoints or dissolved oxygen setpoints according to whether the gas oxygen sensor 12 or the dissolved oxygen sensor 28 , 30 is providing the feedback to the oxygen control loop 160 . Oxygen setpoints for each culture chamber 36 can be entered to the oxygen servo control loop 160 manually by the operator one at a time at the operator interface 28 , or multiple setpoints can be entered automatically according to the timing and sequence of a particular profile during-profile control. Profiles are the specific series of timed setpoints that can be created by the user at the operator interface 28 , or can be created by recording 24 the gas oxygen tensions 120 that are generated as the result of direct control of the dissolved oxygen tension 280 while a dissolved oxygen sensor 28 , 30 is driving the oxygen control loop 160 . Once developed, profiles can be stored and used repeatedly. The operator interface 28 may be built into the controller 16 on the front panel 220 or located on an optional remote computer monitor or other console 22 as depicted in FIGS. 2 - 6 .
[0041] The controller 16 may or may not include other control or monitoring functions in addition to dynamic oxygen control, such as the control of temperature, humidity, CO 2 , or other gases. Sensors for these are depicted schematically in FIG. 1 by 14 . For example, since CO 2 is commonly employed in cell culture to maintain pH, it is likely any controlled atmosphere culture chamber 36 , 10 , 38 , 110 , 236 , 238 with dynamic oxygen control will also need CO 2 control. This is depicted schematically in FIGS. 3 - 6 by a tank of CO 2 with a solid arrow representing a necessity for CO 2 control in these embodiments. However, the retrofit embodiment as depicted in FIG. 2 has a hatched arrow for the CO 2 tank to represent the optional inclusion of the CO 2 control function in the oxygen profile controller 16 . Whether CO 2 control is necessary or not depends on the incubator 10 . If the commercially available incubator 10 to be retrofitted with the oxygen profile controller 16 is a CO 2 incubator, the CO 2 control function will not be required in the oxygen profile controller 16 because it is already built into the incubator. However, if the commercially available incubator 10 is just a thermal incubator with no CO 2 control, then CO 2 control will be necessary in the oxygen profile controller 16 . Temperature control involves similar considerations. Since temperature control is commonly necessary, some embodiments will require temperature control built into the oxygen profile controller as well, such as those embodiments depicted in FIGS. 5 and 6. However, if the culture chamber is a commercially available incubator 10 with temperature control as depicted in FIG. 2, or if the culture chambers are sub-chambers 36 , 38 inserted into a temperature controlled host chamber 360 as depicted in FIGS. 3 and 4, no temperature control will be required. Such additional control loops are depicted in FIG. 1 by bi-directional arrows 140 , but will not be discussed further since they are extraneous to the primary invention of dynamic oxygen control.
[0042] In multiple chamber configurations as depicted in FIGS. 3, 4, and 6 , the controller 16 controls oxygen and oxygen profiles and any other pertinent variables (e.g. CO 2 , temperature, humidity) simultaneously but independently in each chamber. Similar or different oxygen tensions can be controlled in each chamber. The same or different profiles can be started and stopped at any time in any chamber without disturbing the other chambers. Only two chambers are illustrated here to represent multi-chamber systems, but multi-chamber systems can consist of any number of chambers. Also, any combination of chambers with gas only, liquid only, or both gas and liquid sensors in the oxygen control loop 160 can be configured into such multi-chamber systems.
[0043] With reference now specifically to FIGS. 2 - 6 , these illustrate various different physical embodiments of the invention. The functional elements that have already been described and shown in FIG. 1 are identified with the same reference numbers in FIGS. 2 - 6 , and a detailed discussion of them need not be repeated here. Also, regardless of which physical embodiment is described in FIGS. 2 - 6 , it should be presumed that each of the depicted culture chambers with dynamic non-static oxygen control may be equipped with the entire complement of functional components depicted in FIG. 1 or any sub-set of functions thereof. That is, any culture chamber in any physical embodiment may be equipped with a gas oxygen sensor only, or a dissolved oxygen sensor only, or both gas and dissolved oxygen sensors that can be switched back and forth. This is depicted in FIGS. 2 - 6 by arrows pointing from the culture chamber to the controller to signify the feedback component of the oxygen profile control loop, but no further distinction will be made. Also, the man-machine interface depicted in FIG. 1 by functional block 28 , as schematized in FIGS. 2 - 6 , is either built into the controller 16 on the front panel 220 or located on an optional remote computer monitor or other console 22 , and need not be discussed further.
[0044] With reference now specifically to FIG. 2, this figure illustrates one physical embodiment in which the oxygen profile controller 16 is designed to retrofit an existing commercially available incubator 10 and control gas oxygen profiles in the entire incubator. If the incubator 10 is a CO 2 incubator with it's own CO 2 control, the oxygen profile controller 16 will not need to control CO 2 . If the incubator 10 has no CO 2 control, the controller 16 may also need to control CO 2 . While a single incubator 10 is shown here, it is possible to design one controller 16 that will control oxygen profiles independently but simultaneously in any number of incubators.
[0045] With reference now specifically to FIG. 3, another physical embodiment consists of one or more sub-chambers 36 , 38 placed inside one or more temperature controlled host chambers 360 . Only two sub-chambers are depicted here 36 , 38 , but any number of sub-chambers is possible. The host chamber 360 may be a commercially available thermal incubator, a commercially available CO 2 incubator with temperature control, a temperature controlled walk-in room, a temperature controlled water bath, or any other suitable host chamber with temperature control. The associated oxygen profile controller 16 controls the oxygen concentration independently but simultaneously in each sub-chamber 36 , 38 . In this case, CO 2 control for each sub-chamber may also be required, even where the sub-chambers 36 , 38 are inserted into a CO 2 controlled incubator, because the sub-chamber atmospheres are isolated from the atmosphere of the host chamber 360 .
[0046] [0046]FIG. 4 specifically illustrates yet another physical embodiment with dynamic non-static oxygen control that works by a method best described as remote conditioning. In this embodiment, gas is controlled remotely from the culture chamber(s) 36 , 38 in a separate mixing chamber 40 or gas stream blender. The controlled gas is then flushed into the various culture chambers 36 , 38 so as to condition their gas phase without actually having real-time gas control in any culture chamber. Conditioning can be continuous or intermittent. Dissolved oxygen sensors, if utilized, would be located in the culture chamber, but the gas oxygen sensor would be required in the mixing chamber 40 or blender. The controlled gas mixtures can be moved by means of a pump 42 or by means of simple pressure differentials. Furthermore, the controlled gas can be circulated back and forth between the mixing chamber/blender and a culture chamber, or it can be infused in one direction through the culture chamber and exhausted out. There may be one gas mixer/blender 40 for each separate culture chamber 36 , or it may be possible to multiplex from one mixer/blender 40 to multiple culture chambers 36 , 38 .
[0047] With reference now specifically to FIGS. 5 and 6, FIG. 5 illustrates an embodiment best described as a completely integrated stand-alone oxygen-profiling incubator 110 , with temperature, CO 2 , and O 2 controls all built in. The oxygen profile controller 116 is built into the incubator cabinet. FIG. 6 illustrates a similar integrated stand-alone oxygen-profiling incubator 210 , but here having more than one chamber 236 , 238 and having a built-in oxygen profile controller 216 for controlling the dynamic non-static oxygen tensions in each chamber 236 , 238 simultaneously but independently. While this illustration depicts two chambers, such an embodiment could have any number of chambers.
[0048] In operation in all the foregoing embodiments, open culture vessels 32 , 33 containing cultures are placed in the culture chamber 36 , and control is initiated in the oxygen control loop 160 and all the other pertinent control loops 140 . Over the duration of the culture, the gas phase oxygen concentration 120 is then raised or lowered as required to regulate the dissolved oxygen concentration 280 in the culture media at the desired levels. However, those actual gas oxygen tensions at those specific times that are required to achieve a desired result may not be obvious or straightforward. That is because the change dynamics of dissolved oxygen 280 as a function of the gaseous oxygen 120 in contact with the liquid is limited by the relatively slow rate of diffusion of oxygen in and out of the liquid phase, and throughout the depths of the medium. Superimposed on this is a potentially rapidly fluctuating oxygen consumption rate by the cells in the culture, which may be changing in number and metabolic activity. However, each specific culture preparation is likely to behave in a reproducible way. That is, if prepared identically, all will have the same diffusion constant as determined by the identical surface area of their gas/liquid interface, and the identical media depth. Plus, the same cells plated at the same density under the same conditions will usually proliferate and metabolize at roughly the same rate and thus create an equivalent demand for oxygen at each time point over the duration of the culture.
[0049] The best specific gas oxygen profile for any given culture preparation can be determined by culturing in a chamber 36 fitted with both a gas oxygen sensor 12 and a dissolved oxygen sensor 28 , 30 that is not disruptive to the culture of interest. First the oxygen control loop 160 is changed over via a switch 17 to receive feedback from the dissolved oxygen sensor 28 , 30 . Then the desired dissolved oxygen setpoint(s) are entered to the oxygen control loop 160 , and the culture is initiated. As the dissolved oxygen control loop works to control the dissolved oxygen tensions 280 by raising or lowering the gas oxygen tensions 120 , the gas oxygen sensor 12 records the achieved gas oxygen levels 120 and time points associated with these levels since the initiation of the culture. This recording is then used to create a series of timed gas oxygen setpoints that will result in a gas profile that can sufficiently recreate those same dissolved oxygen levels in all those specific culture preparation with identical diffusion constants and cells.
[0050] If the dissolved oxygen sensor 28 , 30 is disruptive to the culture of interest 33 , it may be possible to use an extra expendable witness culture 32 to serve as a surrogate. This extra culture 32 may be an identical sample of the same culture preparation, or a culture preparation designed to be similar to the culture of interest.
[0051] Once the proper gas oxygen profile for a culture is known, and if the culture chamber 36 is fitted with a gas oxygen sensor 12 , the gas oxygen sensor 12 may be used to provide feedback to the oxygen control loop 160 to control the gas oxygen setpoints in the profile. If the chamber also is fitted with a dissolved oxygen sensor 28 , 30 and it is not disruptive to the culture, it will be possible to observe and record the dissolved oxygen concentration 280 to verify that the desired oxygen levels are achieved. If that chamber 36 does not have a dissolved oxygen sensor 28 , 30 due to economic constraints, or if using the dissolved oxygen sensor 28 , 30 is disruptive in any way to the culture of interest and therefore cannot be used due to technical constraints, the gas oxygen profile may blindly control the dissolved oxygen concentration 280 . Furthermore, a gas oxygen profile may be used to control a fixed dissolved oxygen concentration 280 over the course of the culture, or a different profile may be used to deliberately change the dissolved oxygen concentration 280 over the course of the culture, according to the needs of the user.
[0052] If a chamber 36 is fitted with a dissolved oxygen sensor 28 , 30 that is not disruptive in any significant way to the culture of interest, the dissolved oxygen sensor 28 , 30 may be used to provide feedback to the oxygen control loop 160 and directly control oxygen setpoints designated as dissolved oxygen setpoints. A single dissolved oxygen setpoint may be used to keep the dissolved oxygen concentration 280 constant over the course of the culture, which is likely to but may not necessarily result in a dynamic change in the gas oxygen concentration 120 in order to do so. Alternately, a series of dissolved oxygen setpoints as specified in a dissolved oxygen profile may be controlled in order to deliberately change the dissolved oxygen concentration 280 over the course of a culture, which is likely to but may not necessarily result in a dynamic change in the gas oxygen concentration 120 . If that chamber 36 also has a gas oxygen sensor 12 , it will be possible to observe and record the gas oxygen level 120 over the course of the culture. As described previously, if that gas oxygen profile ever needs to be replicated, it can be converted to a series of gas oxygen setpoints in a designated gas oxygen profile. If that chamber 36 is not equipped with a gas oxygen sensor 12 due to economic constraints, it may blindly manipulate the gas oxygen levels 120 in order to control the dissolved oxygen concentration 280 .
[0053] In addition to the incubators and growth chambers discussed above, this dynamic gas control and profiling can be used favorably in glove chambers, refrigerators, plant growth chambers, and any other enclosures in which open culture vessels are placed in order to indirectly control dissolved oxygen (or other gas) by exposure to the controlled atmosphere.
[0054] Although the preferred embodiment has been employed in connection with cell and tissue culture in open culture vessels consisting of plastic or glass plates, flasks, micro-wells, beakers, etc., it is possible to employ the principles of this invention in other applications where the concentration of a dissolved gas can be optimized over time by the dynamic change of the gas concentration in the gas phase that is in contact with the liquid.
[0055] While the invention has been described with reference to specific preferred embodiments, the invention is certainly not limited to these precise embodiments. Rather, many modifications and variations will become apparent to persons of skill in the art without departure from the scope and spirit of this invention, as defined in the appended claims. | During growth of tissue culture in a controlled atmsophere incubator the oxygen (another environmental gas) is dynamic controlled according to an oxygen profile (or other profile). Gaseous oxygen concentration is deliberately changed over time in a precise and reproducible way, with other parameters being held constant, or with other controlled parameters being changed simultaneously or sequentially. Oxygen profile is developed based on the amount of gas phase oxygen needed to maintain the dissolved gas in the culture medium at a desired level. A gas controller is programmed with the gas profile, and the oxygen is dynamically controlled according to the oxygen profile. The specific sequence and timing of changes in gaseous oxygen concentration that best indirectly regulate the desired dissolved oxygen concentration in the culture media inside open culture vessels that are placed inside the incubator. | 2 |
FIELD OF THE DISCLOSURE
The present disclosure relates to a musical training device for measuring the air support applied to a musical instrument, so that the musical training device alerts the musician when the air support applied to the instrument is sufficient to produce an acceptable musical tone.
BACKGROUND
Wind musical instruments can be divided into two large classes, the woodwind instruments and the brass instruments. The woodwind instruments include those with reeds (saxophone, clarinet, oboe, and bassoon) and those with resonance openings (piccolo and flute). To produce sound the musician forms a pressure cavity with his mouth and blows air into or over (for piccolo and flute) the mouthpiece. The air travels through the reeded mouthpiece intermittently as the reed vibrates, or passes over the resonance opening in the flute and piccolo. Both actions cause the air mass in the mouthpiece to oscillate in pressure. This pressure oscillation then propagates into the musical instrument thereby producing sound. By varying the length of the air column in the instrument (by opening and closing valves on the instrument), tones of different frequencies are produced.
Many factors have an impact on the musical tone that is produced. The design of the instrument mouthpiece itself can have profound effects. For example, the design and depth of the tone chamber and the type of reed employed can alter the tone. In addition, the tuning or repair of the instrument can be a factor. These and other affects are equipment related. Parameters relating to the artist's technique include air speed or air pressure (known in the field as air support) and embouchure, both of which are factors that affect the musical tone. Embouchure is the physical placement of the artist's mouth on the instrument and includes the development of a pressure chamber to blow air into or over the mouthpiece. Air pressure in the mouth cavity and air velocity in a stream of air blown from the mouth are directly related mathematically (Bernoulli equation). Teachers of woodwind instruments are generally agreed that the foundational parameter for proper technique in these instruments is air support (pressure) for reeds, or air speed for flutes and piccolo.
The role of the embouchure is to provide an efficient pressure chamber by which to direct air into the mouthpiece and to allow the reed to vibrate freely or provide the correct flow (speed) of air over the open hole (flute and piccolo). A correct air support will strengthen the embouchure, while a weak one will damage it. In short, without proper air support, the student cannot produce a tone even with a good embouchure. If the musician does not produce the proper air support, the tendency is to compensate for the improper air support by altering the embouchure. As a result, a poor musical tone will be produced. Therefore, it is essential that a musician learn how to produce the proper air support consistently as the baseline for proper musical technique development.
In order to avoid the problems that are associated with improper air support, music instructors spend a great deal of time teaching musicians how to produce the necessary air support that will produce an acceptable musical tone. However, it is quite difficult to teach a student how to produce the proper air support without some feedback on the results of his or her efforts. Unless the musician already knows how producing the correct air support relates to an acceptable musical tone, the musician will require an instructor or some other knowledgeable observer in order to learn the correct level of air support. Furthermore proper air support varies with the instrument.
There are several training devices that are currently available that attempt to teach a musician how to produce the proper air support. However, they all suffer from disadvantages in their use. For example, U.S. Pat. No. 5,749,368 to Kase describes a breath air flow device that can be used to measure the air support applied to the device and provides a gauge readout of the air pressure downstream of the mouthpiece. A standard mouthpiece can be connected to the device, and the resistance of the device to the air that is flowed through the mouthpiece can be changed by opening and closing an aperture in the device in order to simulate the “feel” of different musical instruments. However, the device described by Kase suffers from the disadvantage that no sound is produced. While a musician may be able to correlate the feel of producing air support that produces a certain pressure reading, the musician will not be able to associate how producing that level of air support feels with how an acceptable musical tone sounds. In addition, since the musician is not using his/her own instrument, the musician must manipulate the aperture to make the device simulate the feel of his/her own instrument. Obviously, if the aperture setting is not correct, the device will not be even minimally effective as the musician will be training to produce an incorrect air support.
Therefore, what is needed is a training device that will measure the air support applied to a musical instrument and provide a signal to the musician when the air support is sufficient to produce an acceptable musical tone. This feedback signal must be generated while the musician is playing the instrument in a normal fashion, i.e., without any interference from the measurement device. In this manner, the musician will be able to correlate the feel of producing an air support sufficient to produce an acceptable musical tone with the sound of that tone. In addition, since the needed device allows a musician to use his/her own instrument, the issue of training to produce an air support that may be correct for a training device, but not appropriate for the musician's instrument is made mute. The present disclosure describes such a device.
SUMMARY
The present disclosure describes a musical training device that can measure the air support applied to a musical instrument and alert the musician when he or she is providing sufficient air support to produce an acceptable musical tone. In addition, the device can be incorporated into a musical instrument without altering the manner and style in which the musical instrument is played. Therefore, the musician can correlate the feel of producing an air support sufficient to produce an acceptable musical tone with the sound of the musical tone. There are no special adjustments to be made by the musician to the device to attain the benefits described as was required by many of the devices of the prior art.
The present disclosure describes a musical training device comprising a modified mouthpiece and a pressure sensor operationally coupled to the mouthpiece. The mouthpiece is of conventional design for a given type of musical instrument and comprises a directing means, such as an air passage within the mouthpiece, to direct at least a portion of the air support applied to the instrument to the pressure sensor. The pressure sensor comprises a measuring means, an indicating means and a housing to contain at least a portion of the above components. The measuring means comprises the components required to measure the air support applied to the instrument by a musician and to determine when the air support applied to the musical instrument is sufficient to produce an acceptable musical tone. The indicating means is functionally coupled to the measuring means and comprises the components necessary to alert the musician when the measuring means determines the air support applied to the instrument is sufficient to produce an acceptable musical tone. The housing comprises the components required to functionally arrange the components of the pressure sensor. In one embodiment, the measuring means comprises a flexible diaphragm in communication with a spring switch and a power source, the power source separated from the spring switch by a distance. The indicating means may comprise a light emitting diode, an incandescent light bulb or similar element that is capable of alternating between a first state and a second state. In the description that follows, the first state will alert the musician that the air support applied to the instrument is sufficient to produce an acceptable musical tone, while the second state will alert the musician that the air support applied to the instrument is not sufficient to produce an acceptable musical tone. It is preferred that the first state be characterized by a light emitting from the indicating means and the second state be characterized by an absence of light emitting from the indicating means.
In operation, the indicating means is functionally coupled to the measuring means in such a manner that when the air support applied to the instrument reaches a predetermined level sufficient to produce an acceptable musical tone, the measuring means causes an electrical circuit to close and current to flow through the indicating means, which causes the indicating means to switch to the first state. In the embodiment described above, when the air support is sufficient to produce an acceptable musical tone, the diaphragm flexes upward, an amount sufficient to bring the spring switch into contact with the power source. As a result, current flows from the battery into the indicating means, causes the indicating means to switch to the first state.
The first state of the indicating means alerts the musician that the air support being applied to the instrument is sufficient to produce an acceptable musical tone. The indicating means may be visible to the musician only, to an observing party only (such as a music instructor) or to both the musician and an observing party. It is preferred that at least the musician be able to view the indicating means at all times. Since the musician is provided with immediate feedback regarding the proper air support needed to produce an acceptable musical tone, the musician can learn and train to associate the correct air pressure with an acceptable musical tone.
The detailed description, in conjunction with the figures provided, will discuss various embodiments of the musical training device and its method of operation. The musical training device of the present disclosure can be adapted to fit any woodwind musical instrument, including, but not limited to, the saxophone, clarinet, piccolo and flute. For the instruments that are played by blowing a stream of air over a resonance opening (flute and piccolo), a pitot tube may be used to measure the air velocity. The pitot tube is a gas dynamic device that converts air velocity to air pressure (commonly used on airplanes). It is positioned on the mouthpiece at a location such that at least a portion of the air stream from the player's mouth impacts the tube and is converted to pressure. Hence for all the woodwind instruments, air support produced by the musician is the quantity measured by the musical training device herein disclosed. The figures described below illustrate a musical training device intended for use with a clarinet, but this illustration is way of example only and should not limit the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional side view of one embodiment of the musical training device of the present disclosure.
FIG. 2 is an exploded cross sectional side view of one embodiment of the musical training device of the present disclosure.
FIG. 3 is a cross sectional side view illustrating one embodiment of the arrangement of the pressure sensor in the housing; and
FIG. 4 is a circuit diagram illustrating one embodiment of the electrical circuit.
DETAILED DESCRIPTION
In the specification and claims that follow, the following terms should be given the definitions set forth below: Acceptable musical tone—An acceptable tone from a musical instrument is one that sounds the fundamental frequency and the overtone characteristic to that particular instrument. This can be determined electronically, but is more commonly judged by a musician experienced with the instrument being played. Air support—The pressure generated by the musician using his/her lungs and diaphragm and applied to the musical instrument.
With reference to FIGS. 1-4 a novel musical training device employing the concepts of the instant disclosure will be described. The musical training device 10 comprises a mouthpiece 12 for use with a musical instrument and a pressure sensor 14 operationally coupled to the mouthpiece 12 . The mouthpiece is of conventional design common for a given musical instrument and comprises a directing means to direct at least a portion of the air support applied to the instrument to the pressure sensor 14 . The pressure sensor 14 comprises a measuring means, an indicating means and a housing 16 , the measuring means and the indicating means being at least partially enclosed in the housing 16 . The measuring means comprises the components required to measure the air support applied to an instrument by a musician and to determine when the measuring means determines the air support applied to the instrument is sufficient to produce an acceptable musical tone. The indicating means is functionally coupled to the measuring means and alerts the musician when the air support applied to the instrument is sufficient to produce an acceptable musical tone. The musician may be alerted either though a visual signal, an audio signal or any other signal method made responsive to the measuring means, however, a visual signal is preferred.
In the embodiment illustrated, the measuring means comprises a flexible diaphragm 100 in communication with a spring switch 102 and a power source 104 . The spring switch 102 is separated from the power source 104 by a distance, the distance preferably being adjustable. The indicating means may comprise a light emitting diode, an incandescent light bulb or similar element that is capable of alternating between a first state and a second state. As stated above, the first state will alert the musician that the air support applied to the instrument is sufficient to produce an acceptable musical tone, while the second state will alert the musician that the air support applied to the instrument is not sufficient to produce an acceptable musical tone. It is preferred that the first state be characterized by a light emitting from the indicating means and the second state be characterized by an absence of light emitting from the indicating means.
In operation, the indicating means is functionally coupled to the measuring means in such a manner that when the air support applied to the instrument reaches a predetermined level sufficient to produce an acceptable musical tone, the measuring means causes an electrical circuit to close and current to flow through the indicating means, which in turn causes the signaling means to switch to the first state. In the embodiment described above and illustrated below, when the air support reaches the predetermined level, the diaphragm 100 flexes upward a sufficient amount so that the spring switch 102 traverses the distance and contacts the power source 104 such that current flows from the battery into the indicating means causing the indicating means to switch to a first state.
With reference to FIGS. 1 and 2, the mouthpiece 12 comprises a tip opening 18 and a generally cylindrical opening 20 opposite the tip opening 18 for joining the mouthpiece 12 to a musical instrument (not shown). Upper side 22 and lower side 24 extend from the tip opening 18 to the second opening 20 and are joined by an outer wall. The upper side 22 , lower side 24 and outer wall define the mouthpiece, and further define an interior tone chamber 28 . The mouthpiece 12 further comprises a directing means. The function of the directing means is to direct at least a portion of the air support applied to the instrument to the sensor 14 such that the air support is in communication with the measuring means. In FIGS. 1 and 2 the directing means comprises an internal channel 30 extending from the tip opening 18 to the upper side 22 , specifically to inlet channel 56 on receiving notch 32 , such that the air support is in communication with the measuring means. Other configurations of the directing means are possible, such as an external tube or hose that delivers at least a portion of the air support to the measuring means as described above. For certain musical instruments, such as the flute and piccolo, a pitot tube is used to divert a portion of the stream of air blown across the resonance opening to the pressure sensor 14 . Therefore, the pitot tube is also considered to be an alternate embodiment of the directing means and should be considered within the scope of the disclosure.
The housing 16 functionally arranges and protects at least a portion of the measuring means and the indicating means and is coupled to the mouthpiece 12 . Although many arrangements are possible, the applicant provides the following embodiment as illustration. Other arrangements that accomplish the functional arrangement are within the ordinary skill of one in the art and should be considered within the scope of this disclosure. With reference to FIGS. 1-3, the housing 16 comprises a mouthpiece adapter base 50 , a cap 52 and an internal housing 54 , the base 50 and cap 52 being adapted to adjustably receive the internal housing 54 . Generally, the base 50 serves to support the measuring means, the internal housing 54 functions to hold the power source 104 and the cap 52 serves to provide a seal for the housing and to receive a portion of the indicating means.
The base 50 is functionally coupled to the mouthpiece 12 such that the air support applied to the instrument is brought into communication with the measuring means. The base 50 is coupled to the upper side 22 of mouthpiece 10 . Several means to couple the base 50 to upper side 22 are possible. FIG. 2 illustrates base 50 interacting snugly with receiving notch 32 of upper side 22 so that base 50 is retained in notch 32 via adhesive bonding. Alternatively, the base 50 may be retained in notch 32 by a pressure fit or through the use of complementary threaded sections on the base 50 and notch 32 . In each of these methods to couple the pressure sensor 14 to the mouthpiece 12 , the path of the air support to the measuring means must be maintained. Other means for coupling that maintain the path of the air support to the measuring means are within the ordinary skill of one in the art and should be considered within the scope of this disclosure.
The base 50 has a bottom 58 and a generally circular wall 60 . The base 50 has a housing inlet channel 56 in bottom 58 in register with the directing means, in this case internal channel 30 , for delivering the air support to the measuring means, which is illustrated in FIGS. 1-3 as diaphragm 100 , spring switch 102 and power source 104 . The spring switch 102 is separated from the power source 104 by a distance when no air support is being applied to the instrument. The diaphragm 100 rests on the bottom 58 and is in communication with the air support delivered via the internal channel 30 and inlet channel 56 and the spring switch 102 . A gasket (shown in this embodiment as an O-ring) 62 separates the spring switch 102 from the internal housing 54 .
The internal housing 54 comprises a generally circular outer wall 64 which defines a cavity 65 , with an internal lip 66 extending around the circumference of one end of the wall 64 into cavity 65 . The exterior surface of the outer wall 64 has machine threads 68 for interaction with complementary threads 51 and 53 on the interior of wall 60 of base 50 and wall 80 on cap 52 , respectively. Therefore, the internal housing is removably and adjustably coupled to the base 50 and cap 52 . Any means that will allow this removable coupling can be used. A power source insulator 70 fits within internal housing 54 and comprises a generally circular wall 71 , with an internal lip 72 extending around the circumference of one end of the wall 71 into cavity 65 . The insulator 70 and spacer 73 isolate the power source 104 from the remainder of the housing 16 and ensure the electrical circuit path necessary for the activation of the indicating means is maintained by preventing the battery from contacting any conducting components that may cause a short in the electrical circuit (discussed below). A spacer/insulator 73 with opening 74 rests on power source 104 to add further insulation. The opening 74 in the spacer 73 allows components of the indicating means to be in communication with the power source 104 . In the embodiment illustrated, the indicating means is shown comprising a light emitting diode (LED) 106 , with a positive leg 108 and a negative leg 110 , both functionally linked to the LED 106 . The positive leg 108 extends through opening 74 to be in contact with power source 104 , while the negative leg 110 rests on the spacer 70 in contact with a conductive element, illustrated as the components of the housing 16 . However, the conductive element may be a section of conductive foil arranged within housing 16 or an additional section of wire. The function of the conductive element is to provide a return path for the current flow back to the power source 104 to produce a closed electrical circuit when required. The cap 52 comprises a top side 78 and a generally circular outer wall 80 surrounding the top side 78 . The top side 78 has an opening 82 to receive at least a portion of the indicating means, in this embodiment the LED 106 .
The pressure sensor 14 functions to provide a signal to the musician when the air support reaches a predetermined level sufficient to produce an acceptable musical tone as determined by the measuring means. In operation of the embodiment illustrated, the diaphragm 100 is in communication with spring switch 102 and is situated on bottom 58 of base 50 such that the diaphragm is in communication with the air support delivered by the internal channel 30 (directing means) and inlet channel 56 . As a result of this placement, the diaphragm 100 is responsive to the air support applied to the instrument, causing the diaphragm to flex upwards (away from bottom 58 ) and bear against spring switch 102 when air support is applied to the instrument. With increasing air support, the diaphragm 100 and spring switch 102 flex upward toward the power source 104 in proportion to the pressure level. With sufficient upward flexing (pressure), the spring switch 102 traverses the distance separating spring switch 102 and power source 104 , and is brought into contact with the power source 104 . In this manner the measuring means creates a closed electrical circuit and current flows from the power source 104 into LED 106 through positive leg 108 , and out of the LED 106 through negative leg 110 , causing the LED 106 to switch to the first state. The current then completes the electrical circuit back to the power source 104 through the conductive element (illustrated here as components of the housing 16 ). The circuit path described above is illustrated in FIG. 4 . However, as discussed above the conductive element may be a separate return wire or an internal conducting element (such as a conductive foil) situated as appropriate within housing 16 . In addition to LED 106 , other indicating means, such as incandescent lights may also be used. The electrical circuit may further comprise an in line resistor to modulate the current supplied to the LED 106 or other indicating means. As the air pressure decreases, the diaphragm 100 and spring switch 102 no longer flex upward a sufficient amount to bring spring switch 102 into contact with power source 104 , and the electrical circuit is opened and no current flows through the indicating means, switching the LED 106 from the first state to the second state.
The distance the spring switch 102 must travel to contact the power source 104 is adjustable by moving the internal housing 54 relative to the base 50 , which can be done by virtue of their threaded connections as illustrated in FIG. 2 . Internal housing 54 compresses O ring 62 to facilitate adjustment of the distance spring switch 102 must flex to contact power source 104 . The adjustment is made to cause the measuring means to close the electrical circuit at a level of air support determined to be that level of air support which is sufficient to produce an acceptable musical tone for a given instrument. As the air support to produce an acceptable musical tone can vary depending upon the instrument, it is important that the measuring means can be adjusted so that the indicating means is switched to the first state at the appropriate level of air support. If the distance is increased, the diaphragm will have to detect increased air support to bring spring switch 102 into contact with the power source 104 , requiring a greater air support before the indicating means is switched to the first state. Alternatively, the type of diaphragm may be altered so that the types of diaphragms used flex upward a different amount in response to a given level of air support. In a preferred embodiment, the pressure sensor 14 is adjusted so that the indicating means is switched to the first state at a pressure level of 15 to 18 inches of water. However, as discussed above, this pressure level can be adjusted either up or down by varying the distance between the spring switch 102 and the power source 104 , or by varying the diaphragm 100 used in the pressure sensor 14 .
The pressure sensor 14 may be modified so that the indicating means is visible to the musician only, to an observer only, or to both the musician and an observer. Such an arrangement can be helpful in various situations. For example, the observer may be a music instructor who may prefer that the indicating means be visible only to him/her and not to the musician in teaching situations. However, when the observer/instructor is not present, it is advantageous that the indicating means be visible to the student for training purposes. The modification may be as simple as a removable cap (not shown) that blocks out one half of the indicating means. When desired the cap may be placed on the indicating means to block the indicating means from being viewed by the musician or the observer and be removed so that both the musician and the observer can view the indicating means.
As discussed above, the pressure sensor 14 may be removable from the mouthpiece 12 . This is advantageous when the sensor 14 needs repair or adjustment or battery replacement. In the present embodiment, base 50 is adhesively bonded to the mouthpiece 12 , but the components of the sensor 14 can be removed for replacement of the power source 104 . All other parts of the pressure sensor 14 may be removed by unscrewing the internal housing 54 and indicator cap 52 .
The components of the pressure sensor 14 and the sensor housing 16 may be constructed from a variety of materials. The choice of materials can be made based on durability, costs and aesthetic considerations. In the present embodiment, the housing 16 is used to complete the electrical circuit used to provide current to the signaling means as discussed above and illustrated in FIGS. 1-4. When the housing 16 is used in this manner, it is preferred that the base 50 , cap 52 and internal housing 54 be manufactured from conductive materials such as aluminum or brass. If conductive materials are not used, a wire may be used to complete the electrical circuit, or the interior parts of the housing 16 may be lined with a conductive foil as appropriate.
The diaphragm 100 must be constructed of a flexible membrane. In the present embodiment, the diaphragm 100 is made of thin latex rubber, but other rubbers may be used. The spring switch 102 must exhibit elastic characteristics and be conductive. In the present embodiment, the spring switch 102 is constructed of phosphor bronze, but other conductive materials may be used. The power source 104 , LED indicator 106 and O ring 62 are commercially available and several varieties and sizes may be used. Battery size and LED characteristics together determine battery life. The battery insulator 70 and spacer/insulator 73 may be made of a variety of non-conducting materials. The mouthpiece 12 may be constructed from any material, but a variety of hard plastics are in more common use in musical instruments. | Disclosed is a musical training device to determine when the air support applied to a musical instrument is sufficient to produce an acceptable musical tone, and to alert the musician when the air support required to produce an acceptable musical tone has been achieved. The device can be incorporated into a musical instrument without altering the manner and style in which the musical instrument is played, allowing the musician to correlate the feel of producing an air support sufficient to produce an acceptable musical tone, with the sound of the correct musical tone. | 6 |
BACKGROUND OF THE INVENTION
The invention relates to devices which are associated with turnstiles in order to permit their angular movements in a particular direction whilst instantaneously preventing their returns or angular movements in the reverse direction from the preceding one.
It relates more particularly, among these devices, to those which are arranged so as to exert as desired their instantaneous angular blocking role in one direction or the other and which comprise for this purpose:
a drum of revolution of axis X fast to the turnstile and coaxial with the latter,
a fixed vee whose bisector plane contains the axis X of the drum, this vee being open on the side of this drum and positioned at a short distance from the latter,
a roller of axis parallel with the axis X, interposed between the vee and the drum and mounted so that, on a moveable support, it can be moved between a first end position for which it is blocked by wedging between the drum and one side of the vee and a second end position for which it is blocked by wedging between the drum and the other side of the vee,
and electromagnetic means to urge the support as desired towards one or other of its two end positions corresponding to the end positions of the roller.
Such a dual-action angular anti-return device operates in the following manner.
When the roller is placed in either one of its two end wedging positions by suitable energization of the electromagnetic means, it is not possible to make the drum, and hence the turnstile, rotate in the direction which would tend to increase this wedging of the roller through the effect of friction which exists between this roller and the drum.
On the contrary rotations of the drum and of the turnstile in the reverse direction are possible at least when authorization thereof is given by control means known to the technician and outside the present invention.
When the electromagnetic means are not energized, the roller is found to be in an unwedged neutral position and angular movements of the turnstile are possible in both directions, provided that the abovementioned authorization has been given.
Dual-action angular anti-return devices of the above type have been described in U.S. Pat. of Applicant No. 4658940 and in general give every satisfaction.
However it may happen that certain difficulties will be encountered to suppress the angular blocking of the turnstile produced for a given direction in the manner indicated above: in certain cases, this suppression is not ensured automatically by simply annulling the energization of the electromagnetic means which have caused said blocking.
Now such automatic suppression is obligatory in certain installations, for example, to render possible an emergency evacuation under circumstances manifested by cutting off the general electrical supply of the anti-return device concerned.
In such circumstances, special means must be provided to temporarily and automatically urge the support of the roller in reverse direction from the preceding one.
GENERAL DESCRIPTION OF THE INVENTION
It is a particular object of the invention to provide such means enabling such sollicitations to be ensured temporarily and automatically in reverse direction.
Accordingly, the electromagnetic control means of the angular anti-return devices according to the invention comprise also two electro-magnets associated with the support of the roller so as to urge respectively this support in two reverse directions on their respective energizations, a source of electrical DC current and switch means enabling said source to be connected alternately to each of the electromagnets for its supply, or to neither of them, and they are characterized in that they comprise in addition an electrical capacitor mounted so as to be charged by the source each time that any one of the two electromagnets is supplied by this source and to be automatically discharged into the other electromagnet as soon as said supply is interrupted.
In advantageous embodiments, recourse has been had in addition to one and/or other of the following features:
the source is connected to the terminals of three circuit sections mounted in parallel with one another, namely a first section comprising the capacitor, a resistor and the contact placed in a first position of a two-position electric switch, a second section comprising one of the electromagnets and a first switch, and a third section comprising the second electromagnet and a second switch, and the capacitor is mounted so that on the one hand one of its plates is connected to the first terminals, of the two electromagnets, which are connected in common to the source and that on the other hand its other plate is connected, through the contact, of the abovesaid two-position switch, placed in its second position, either to the second terminal of the second electromagnet through a third switch, or to the second terminal of the first electromagnet through a fourth switch,
the source is joined to the terminals of a fourth section of circuit comprising the coil of a relay adapted to actuate said two-position switch,
the first switch is associated with the third switch so as to be opened and closed at the same time as the latter and it is the same with the second and fourth switches,
in a device according to the preceding paragraph, each of the pairs of switches composed respectively of the first and third switches and of the second and fourth switches is mounted so as to be actuated automatically by the support of the wedging roller.
The invention comprises, apart from these main features, certain other features which are preferably used at the same time and which will be more explicitly considered below.
In the following, a preferred embodiment of the invention will be described with reference to the accompanying drawing given of course purely as a non-limiting example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 of this drawing show diagrammatically an angular anti-return device with two directions of blocking associated with a turnstile and constructed according to the invention, in two different states corresponding respectively to the blocking of the turnstile in one direction and to the beginning of a subsequent unblocking due to a current failure.
FIG. 3 shows diagrammatically a portion of a modification of the same embodiment also constructed according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
The turnstile 1 is here shown schematically by an arm mounted pivotally around an axis X.
This turnstile 1 is associated with any desirable locking, control, elastic return, damping . . . means: these means are known and do not form part of the invention so that they will not be described in the present specification.
In manner known in itself,
the angular movements of the turnstile are permitted in a first direction under certain conditions, such as the prior introduction of a valid ticket into an associated apparatus, and they are prevented in the opposite direction, at least beyond a given amplitude,
in addition means are provided to select at will the direction S1 or S2 for which the angular movements of the turnstile are blocked.
For this purpose recourse is had to an anti-return device comprising:
a drum of revolution 2 of axis X angularly fast to the turnstile 1,
a vee 3 bounded externally by two flat or slightly concave ramps 3 1 and 3 2 which intersect along a line Y parallel with the axis X, this vee being turned towards the drum and its bisector plane comprising the axis X,
a roller 4 of axis Z parallel with the axis X, interposed between the drum 2 and the vee 3 and mounted on a movable support 5 so as to be movable between a first end position for which it is wedged between one 3 1 of the ramps of the vee and the drum and another end position for which it is wedged between the other ramp 3 2 of the vee and the drum,
and electromagnetic means adapted to urge in turn the support 5 towards its two end positions corresponding to the wedgings of the roller.
These wedgings are obtained due to the fact that the distance between each ramp 3 1 , 3 2 and the drum is slightly less than the diameter of the roller.
The electromagnetic means comprise:
a source 6 of DC electric current,
two electromagnets 7 and 8 arranged on each side of the support 5,
and an electric circuit connecting the source 6 to the electromagnets 7 and 8 so that there may be ensured as a function of need the energization of the electromagnet 7 alone, that of the electromagnet 8 alone and the deenergization of the two electromagnets.
The support 5 is advantageously constituted by a lever mounted pivotally around an axis U parallel with the axis X, which lever is constituted at least in part of a magnetic material so as to be sensitive to the attraction or repulsion of the electromagnets 7 and 8.
The roller 4 is constantly urged towards the bottom of the vee 3, for which position it is separated from the drum 2.
This solicitation can be exerted by a spring, but it is advantageously obtained through simple gravity, in which case the vee is situated beneath the drum, of which the axis X is then horizontal or slightly inclined to the horizontal,
The operation of the device is as follows.
When none of the electromagnets 7 and 8 is energized, the roller 4 is applied to the bottom of the vee 3.
The rotations of the drum 2 are then free in both directions S1 and S2, likewise those of the turnstile 1.
If the electromagnet 7 is energized by connecting it to the source 6 (see FIG. 1), the support 5 is attracted magnetically by this electromagnet in the direction of the arrow F, which draws the roller 4 up to its end position for which it is wedged between the ramp 3 and the drum 2.
For this end position, rotations of the drum 2--and hence those of the turnstile 1-- are still possible in the direction S1, but this is no longer the case in the opposite direction S2 since the roller 4 then exerts a wedging effect in this direction: in fact, any attempt at angular movement of the drum 2 in this direction S2 tends to draw the roller in said direction due to the fact of the friction which exists between this roller and the drum; now it cannot be drawn thus due to the fact of the throttling defined by the facing surfaces of the ramp 3 1 and of the drum 2 beyond the end position then occupied by the roller 4.
To eliminate this angular blocking of the turnstile in the direction S2, it suffices generally to suppress the energizing of the electromagnet 7, which suppresses the magnetic attraction force F.
Such deenergization is, for example, obtained by the opening of a switch 9 mounted in series with the source 6.
What has just been explained for the blocking of the turnstile in the direction S2 is exactly transposable to the blocking in the direction S1: it suffices for this purpose to replace the electromagnet 7 by the electromagnet 8 in the foregoing description.
In certain cases, the simple suppression, indicated above, of the energizing of the electromagnet does not suffice to unwedge the roller 4.
The invention enables this drawback to be overcome by exerting automatically, and for a brief moment, on the support 5 a force opposite that which has caused the wedging of the roller, and whose intensity is sufficient to ensure unwedging.
This opposing force is exerted magnetically like the preceding one.
More precisely, there is provided a capacitor 10 mounted so that it is automatically charged by the source 6, through a resistor 11, when this source supplies any one of the two electromagnets 7 and 8 and so that it is automatically discharged into the other electromagnet as soon as said supply is cut off.
The relatively brief energization which is thus obtained of the "other" electromagnet has the effect of attracting the support 5 in the reverse direction from the preceding one.
In FIG. 2, which corresponds to the unblocking phase consecutive to the blocking described with reference to FIG. 1, the opposing unblocking force has been shown diagrammatically by the arrow G and corresponds to a discharge of the capacitor 10 into the electromagnet 8.
To be able to ensure the different blockings and unblockings of the roller 4 very simply for the two possible directions of blocking by means of a single capacitor 10, recourse is advantageously had to the electrical system illustrated in the drawings.
In this system, the terminals of the assembly constituted by the source 6 and the switch 9 are joined to four circuit sections mounted in parallel with another, namely:
a first section comprising in series a capacitor 10, the contact of a switch 12 1 placed in one of its two positions, called first position below, and the resistor 11,
a second section comprising the electromagnet 7 and a first switch 13,
a third section comprising the electromagnet 8 and a second switch 14,
and a fourth section constituted by a relay coil 12 adapted to actuate the switch 12 1 so that the energizing of this coil places the contact of said switch in its first position and conversely.
In addition the capacitor 10 is mounted as follows.
One of its two plates is connected to the common terminal, of the two electromagnets 7 and 8,--which terminal will be called below first terminal--, which terminal is joined to the source 6 without passing through one or other of the switches 13 and 14.
The other plate of the capacitor 10 is connected, through the contact of the switch 12 1 placed in its second position:
on the one hand to the second terminal of the electromagnet 8 through a third switch 15,
and on the other hand to the second terminal of the electromagnet 7, through a fourth switch 16.
The first switch 13 is coupled with the third switch 15 so that their respective closings and openings are simultaneous and this is the same for the second switch 14 with the fourth switch 16.
The operation of the circuit thus defined is as follows.
Suppose initially that it is desired to block the turnstile in the direction S2 (FIG. 1).
It suffices for this purpose, of course after closure of the switch 9, to close the dual switch 13,15.
The consequence of these closings is double:
on the one hand the electromagnet 7 is energized from the source 6 through the closed contact of the switch 13, which exerts on the lever 5 the force F and places the roller 4 in its position of blocking or wedging the turnstile in the direction S2.
on the other hand the relay 12 is energized and the capacitor 10 is therefore charged through the contact of the switch 12 1 placed in its first position.
The turnstile is hence free to rotate in the direction S1, when permission therefor is given, but not in the direction S2.
From this situation, if the energizing of the electromagnet 7 is cut off by the opening of the switch 9, immediately and automatically the following effects are observed:
the force F is annulled,
the relay 12 is deenergized, which places the contact of the switch 12 1 in its second position, and the capacitor 10 is discharged into the electromagnet 8 through the closed contact of the switch 15, which exerts on the lever 5 the unblocking force G.
This lever 5 therefore returns to its neutral position (FIG. 2).
To ensure the desired wedging of the turnstile again in the direction S2, it then suffices to reestablish the continuity of the circuit by reclosing the switch 9.
In view of the total symmetry of the circuit with respect to the energizations of the two electromagnets, the blocking of the turnstile in the single direction S1 is ensured by closing the double switch 14,16 instead of closing the dual switch 13,15, and the consecutive unblocking of the turnstile is automatically actuated as previously by simple opening of the switch 9.
This switch 9 may be that of a manually reset circuit breaker.
It may also be quite simply constituted by the accidental interruption of the circuit following wear or an accident.
The actuation of the dual switches 13,15 and 14,16 may also be ensured manually.
According to an advantageous embodiment enabling assurance of correct actuation in each case and this alone, the controls concerned of the dual switches are servo-coupled to the movements of the lever 5.
Thus the simple placing of this lever 5 in its blocking position corresponding to FIG. 1 may be automatically manifested by the closure of the dual switch 13,15, and of the latter only, which, as described above, results successively in the constant maintenance of the lever 5 in the blocking position that it then occupies, then on the contrary its forced unblocking on the occurrence of a current failure. There is also to be seen in the drawings two abutment rollers 17 applied against the drum 2 so as to balance the transverse thrusts exerted by the roller 4 on this drum and hence on the shaft 18 of the turnstile.
As a result of which, and as emerges besides already from the foregoing, there is finally obtained an antireturn device for a turnstile whose constitution and operation are seen sufficiently from the foregoing.
This device presents over those previously known the advantage of ensuring with certainty the unwedging of the roller 4 every time that it is desired to restore to the turnstile a freedom of angular movement involving such unwedging.
As is self-evident, and as emerges besides already from the foregoing, the invention is in no way limited to those of its types of application and embodiments which have been more especially envisaged; it encompasses, on the contrary, all modifications thereof, particularly that illustrated in FIG. 3.
According to this modification, the third and fourth switches 15,16, instead of being coupled respectively to the first and to the second switches 13,14, are actuated respectively by two relays 17,18 mounted so as to be automatically energized by the simple closings of said first and second switches: more precisely, the first relay 17 is mounted in series with the first switch 13, between the latter and the common terminal of the two windings of electromagnets 7 and 8 and the second relay 18 is mounted in series with the second switch 14, between the latter and the abovesaid common terminal.
The two relays 17 and 18 advantageously form together a double bi-stable relay.
This modification is interesting in that it requires for its operation the closings of simple contacts 13 and 14, which may be presented in the form of micro-contacts actuatable in the usual manner by simple rotations of the turnstile. | The invention relates to a dual-action angular anti-return device for a turnstile, comprising a drum fast to the turnstile, a fixed vee open facing the drum, a roller positioned between the vee and the drum and alternately wedgeable between the two faces of said vee and said drum, a support for the roller displaceable alternately by two electromagnets themselves energizable from a source. A capacitor is charged by the source on each energization of any one of the electromagnets and discharged into the other electromagnet as soon as said energization is interrupted, which then results in the desired unwedging of the roller. | 5 |
FIELD OF THE INVENTION
[0001] The present invention is an improvement in the apparatus disclosed in my prior U.S. Pat. Nos. 4,964,748 and 5,560,728, both of which are incorporated herein by reference. Each of these patents relate to articulated arms and locking devices for a surgical head clamp such as is used in neurosurgery.
BACKGROUND OF THE INVENTION
[0002] As described in above noted prior US patents, with the use of head clamps for positioning a patient's head for neurosurgery or other cranial surgery, it is necessary to provide a rigid support for the head and one which can be easily adjusted to allow access by the surgeon to selected portions of the head of the patient during an operation. To this end, my prior structures have provided three articulated arms each with locking levers so that once the head of a patient has been placed in a position as desired by the surgeon, the head can be locked in place. With my structure, selecting any position in space is a continuously variable, analog function. Also, during surgical operations, it is important that the stability and rigidity of the head supporting structure be assured once the position selection has been made. In the past, use of a number of types of head support structures has proven inadequate in terms of the possibility of accidental release of the support structure during a medical procedure. While the locking mechanisms of my prior patents noted above have lessened this possibility, there is a need for a head bracket support that will achieve rapid and secure locking of the head bracket in place without the possibility of rotation of the bracket relative to its support or release of the bracket.
SUMMARY OF THE INVENTION
[0003] The present invention provides an improvement in my prior devices that is easily accomplished yet inexpensive to install and which will positively prevent accidental release of the cranial bracket once placed in position for an operation. In a preferred embodiment, the head bracket is modified in that a single post is integrally formed with or attached to a portion of the bracket with the end of the post provided with recesses for cooperating with a holding device which will grip and lock the post against release as well as rotation once the post is inserted. With this arrangement, a quick release is also provided but one which requires a user to grab both the holding device for the post of the bracket as well as the bracket itself to effect release. Thus, accidental release will be discouraged if not positively prevented in all circumstances.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The foregoing and further advantages of the present invention will become apparent as consideration is given to the following description taken in conjunction with the accompanying drawings, in which:
[0005] FIG. 1A is a perspective illustration of the articulated arms of present head clamp support structure which includes elements from my prior support structure;
[0006] FIG. 1B is a side view in elevation, partly in section of a preferred version of the locking levers usable in the structure of FIG. 1A with a button operated locking device on the locking lever;
[0007] FIG. 2 is a side view, partly in section, of the device of FIG. 1 but with the arms rotated to another, selectable position and the levers deleted for clarity;
[0008] FIG. 3A is an enlarged, detailed view of the locking device of the present invention with parts broken away and with the post and ball as well as the clamping device in an unlocked condition;
[0009] FIG. 3 b is a view similar to FIG. 3A but with the post locking device in a locked condition;
[0010] FIG. 4 is a plan view in elevation of a modified head bracket used in my present invention; and
[0011] FIG. 5 is a detailed view, partly in section, of the locking device carried by a modified post and ball similar to the structures of FIGS. 3A and 3B .
DETAILED DESCRIPTION
[0012] Referring to FIG. 1A , there is shown a view of a head positioning device similar to that of my prior U.S. Pat. No. 4,964,748, the disclosure of which is incorporated herein by reference. According to the present invention, the device 10 includes three arms 12 , 40 and 41 with arm 12 being pivotally mounted on a rod 18 and held in position on the rod 18 by a clamping or gripping device 14 which is actuated by a locking lever 20 . When tightened, the grip of the clamping device 14 on the rod 18 secures the arm 12 against rotation about rod 18 which itself will be attached to a rigid support such as a portion of the operating table. The opposite end of the arm 12 also has a similarly designed clamping device 16 which grips a pin 33 as shown in FIG. 2 which is connected to a bracket 34 from one face of which the pin 33 and from the other face of which a pin 35 projects. It will be apparent that the gripping action of the clamps 14 and 16 about their respective pivot members 18 and 33 will be substantially simultaneous upon closing of the lever 20 . The same applies to the other arms 40 and 41 since the lever arm 43 activates gripping at both ends of the arm 40 while the lever arm 52 simultaneously activates the gripping device at 53 and the push lock device at 47 to secure locking device 90 in place. The gripping member 36 of the second arm 40 is adjustably positionable about pin 35 until its locking lever 43 (not shown in FIG. 2 ) is actuated to lock members 36 and 38 on their respective pins 35 and 37 , respectively. Pin 37 projects perpendicularly from one face of bracket 45 and another pin 33 ′ projects from the other face of bracket 45 just as pin 33 projects from bracket 34 . As shown in FIG. 1A , arm 41 is mounted at one end on the pin of bracket 45 while the free end 47 carries a locking device 90 which is described below.
[0013] To ensure stability, the ends of lever arms 20 , 43 and 52 will be provided with catch tabs which are inserted between two tongues as shown at 63 and 64 which are arranged to receive a projection carried on the end of the levers opposite their pivotal attachment to their respective arms. The tongues 63 , 64 will carry a spring biased ball detent to engage a recess on the projection of the respective arm to hold the arm in their locked positions. In a preferred form, the locking of the lever arms may be accomplished by the structure shown in FIG. 1B a variation of which is described in my co-pending application Ser. No. 10/941,604 which is incorporated herein by reference. In FIG. 1B , the locking lever 52 ′ is pivotally mounted on a pin 62 extending between two walls, one of which is shown at 64 , of a gap provided at the end of arm 40 ′. Also mounted on pin 62 is a rod 66 which extends through a bore formed in arm 40 ′. The opposite end of rod 66 is threaded to cooperate with an anchoring nut 70 which can be rotated to adjust the force exerted when the lever 52 ′ is pivoted on pin 62 to bring the leg members 72 and 74 of arm 40 ′ in gripping condition relative to the surfaces of pins 35 ′ and 37 ′. The arm 40 ′ is provided with a receiving cup 78 into which a shaft 76 can be inserted and which is provided with a detent arrangement, such as that described and shown in my copending application Ser. No. 10/941,604, so that once captured, release can only be effected by a conscious effort in pushing on the button 80 that extends through a bore in the lever 52 ′. Other types of arrangements to capture the locking lever arms will be apparent to those skilled in this art.
[0014] With reference to FIGS. 1A and 2 , arm 41 is pivotable about a pin 33 ′ similar to pin 33 but projecting perpendicularly from the face of the bracket 45 which is identical to bracket 34 . Arm 41 can be locked in a position by actuation of the lever arm 52 (not shown in FIG. 2 ) and such actuation will lock gripping member 53 on the pin 33 ′ of bracket 45 and at the same time will actuate the gripping function of locking device 90 at the free end of arm 41 as viewed in FIGS. 1A and 2 and which will now be described with reference to FIGS. 3A and 3B .
[0015] The locking device 90 at the free end of arm 41 will operate to engage and hold the ball 84 from which post 86 extends and with which it is integrally formed. The post 86 is thus adjustably positionable in a socket 88 defined by the cover 91 which is rotatably carried on locking device 90 by the threaded housing 89 attached to body 91 formed on the end of arm 41 . The post 86 is thus free to be positioned at any point relative to the axis of arm 41 through 360° of rotation about the axis of arm 41 and 180° of rotation about socket 88 . A recess 87 is formed on the end of arm 41 to receive the toggle actuator 85 formed on the end of lever arm 52 . An apertured plate 95 cooperates with toggle member 99 to move into or out of contact with the socket body to effect or release locking of the ball 84 in its housing. In FIG. 3A , the ball 84 is released while in FIG. 3B , the ball 84 is in its locked position. The shaft 104 operates in the same manner as shaft 66 described in conjunction with FIG. 2 in so far as the clamping device 53 is concerned so that the movement of the lever 52 will effect gripping of the pin 33 ′ while at the same time moving toggle member 99 upwardly as viewed in this figure to lock the ball 84 in a selected orientation. To this end, the toggle actuator 85 includes a pin 97 which extends through the upper end of shaft 104 . The opposite end of shaft 104 engages the gripping member 53 as shown.
[0016] Prior head brackets similar to head bracket 95 ( FIG. 4 ) would include a hollow tube into which post 86 will be inserted and usually held by a threaded bolt provided in the tube to hold the post 92 in place. The bolt is tightened against the post 86 but any loosening of the threaded bolt will result in rotation of the bracket about the post 86 which is undesirable. In my co-pending U.S. application Ser. No. 10/941,944, a locking device for the levers and the unnumbered lever for the head bracket is provided. The present invention provides a secure mounting in place of the post 86 of a head bracket similar to the bracket shown in my U.S. Pat. No. 5,560,728 but where the head bracket is modified as shown in FIG. 4 to cooperate with the locking feature of FIG. 5 .
[0017] As shown in FIG. 4 , there is shown a conventional head bracket 95 where the mounting post 92 has been modified to include an annular array of spaced apart recesses 94 to cooperate with a holding device 100 as described below. The recesses 94 are preferably adjacent one end of the post 92 . The device 100 , as shown in FIG. 5 , replaces the post 86 shown in FIGS. 3A and 3B on the end of arm 41 . The arm 41 , shown in FIG. 5 , is provided at its end with a head 110 about which the locking device 100 is positioned and which carries a washer 150 rotatably supported between two seal rings 152 and 154 . The locking device 100 is provided at one end with a peripheral flange 132 which extends radially inwardly toward the neck of the washer 150 . The interior wall of the locking device 100 is provided with a radially inwardly extending flange 156 which supports the coil spring 160 on its upper side as shown in FIG. 5 . The lower portion of the head 110 is also provided with a radially outwardly extending flange 158 which on its upper side supports one end of a coil spring 160 which acts between the flanges 156 and 158 to constantly urge the body 62 of the locking device 100 away from the arm 41 in an axial direction.
[0018] At a specific distance from the upper end of the arm 41 , apertures 194 are formed in the wall of the arm 41 with each aperture carrying a detent ball 166 . The apertures 194 will be shaped to limit the extent to which the individual balls may project into the interior 168 of the arm 41 . Preferably, there are at least four apertures and corresponding balls and more preferably, six apertures and balls are used. As shown, the interior of the body 162 is formed with a radially inwardly projecting camming member 170 which has an annular, inner sloping cam surface 172 for engaging the balls 166 . As viewed in FIG. 5 , the lower portion of the surface 172 projects radially inwardly a greater extent than the upper sloping portion. With this arrangement, with the body 162 moved by the coil spring 160 away from the bracket 90 when the post 92 is inserted as shown, the balls are permitted to move away from the post 92 . However, with the post 92 inserted and the body 162 moved downwardly by a user and then released, the lower portion of the camming surface 172 will urge the balls to each engage one of the recesses 94 formed adjacent the end of the post 92 . This action will effectively lock the post 92 in device 100 as well as prevent relative rotation between the post 92 and the arm 41 . Release of the post 92 and the bracket 90 is effected by a user grasping the bracket 90 and then moving the device 100 away from the bracket 90 to allow the upper portion of the camming surface 170 to move downwardly as viewed in FIG. 5 to allow the balls to be pushed back from their projecting position by the force applied by the movement of the post 92 .
[0019] With this arrangement, it will be evident that accidental release of the post 92 is effectively prevented. It will also be apparent that the camming action of the locking device 100 may take a number of forms in addition to the one illustrated. For example, the locking function may be achieved by moving the camming surface axially away from the bracket 12 where the slope of member 70 is opposite to that shown. Another alternative may involve requiring relative movement between two annular members to position or change the position of the camming surface. Further, for increased resistance to accidental release, one can make the spring constant of spring 160 larger than conventional for surgical clamps.
[0020] Having described the invention, it will be apparent to workers in this field that various modifications can be made without departing from the spirit of this invention. | A device for positioning and locking a head clamp in a selective position including a first arm, a second arm and a third arm. The third arm having a free end including both a spherical member carried in a socket and including a mounting tube and a gripping device to restrain movement of said spherical member. The head clamp includes a mounting post for insertion to said mounting tube wherein said mounting tube includes a releasable locking device for engaging and holding said mounting post against rotation and withdrawal of said mounting tube to prevent accidental release of the mounting post. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 11/335,591, filed Jan. 20, 2006 entitled Storm Drain Basin Gate System, now U.S. Pat. No. 7,234,894, issued Jun. 26, 2007.
BACKGROUND OF THE INVENTION
This invention relates generally to a gate system for use with a storm drain of the type typically found in the curb of a street. More particularly, this invention relates to such a system which during periods of low water flow is in a closed position to effectively prevent debris from entering into the storm drain, but which during periods of high water flow opens to allow the maximum amount of water to enter into the drain to alleviate the accumulation of water in the street and the surrounding areas.
What to do with excess runoff rain water has been an issue for urban planners and dwellers for a long time. Even in arid regions, the occasional heavy rainfall will create large volumes of run off that must be channeled effectively or flooding resulting in impassable roads at least or the loss of property and lives at worst may occur. In areas of high annual rainfall, effectively channeling that rainwater away from streets and homes is an absolute must.
For this reason, almost every city in the civilized world has an extensive underground storm drain system. And the most common inlet to the entire system is the ubiquitous curbside opening that is built into the sidewalk curb along the street. Those openings typically lead to a rather large underground chamber, often called a vault, at one end of which there is a conduit that leads to the main storm drain pipe that is usually set under the paved road adjacent the vault.
These drain systems have proven very effective in channeling runoff storm water away from the streets and populated areas, and usually into an adjacent river or into the ocean. However, another ubiquitous part of urban life—street debris and litter—also finds its way into the storm drain system. For example, some cigarette smokers seem to believe that their cigarette butts are not litter to be deposited in a trash can, but something that can be thrown on the ground wherever they happen to be when they must discard the cigarette—thrown into the gutter as they walk along the sidewalk, or thrown out of the car as they drive along. These cigarette butts, which are not environmentally friendly and do not naturally degrade easily, invariably end up in the drain system and then into the river or ocean into which it drains. Other trash, from paper cups to hamburger wrappers to envelops, all find their way into the gutters. drain systems and ultimately river and ocean. And this is just the man-made debris. Natural debris such as leaves and twigs are also commonly found in streets and gutters. and then make their way into the storm drain system when it rains, or when water from some other source makes its way into the street.
It is not just the introduction of these items into the drain system that is a problem. Most storm drain systems ultimately empty directly into a nearly body of water, often a river or the ocean. Also, the systems rarely include any type of intermediate water treatment facility, so what goes into the drain system usually ends up in river, lake or ocean, where it is unsightly and can be toxic.
Because the introduction of trash and other debris into the storm drain system is such a common occurrence, many street side drains are constructed with a sizeable open chamber into which the storm drain opening leads, with the conduit to the under-street pipe located at one end thereof. The purpose of this is to try to trap as much of the debris as possible in the vault, and only allow the water to run-off into the system. This has proven only partially effective. First, so much trash is often introduced into the vault that much of it gets into the system anyway. This is particularly true if there is an accumulation of trash in the vault when there is a heavy rainfall or other heavy flow of water into the vault. Second, this arrangement necessarily requires that the vault be periodically cleaned, and cleaning the vault cannot of course be done by the usual street sweeping equipment, but requires an entirely different piece of equipment with strong suction capability to literally vacuum the trash from the vault. Third, this arrangement is designed to allow the trash to accumulate in the vault in between cleanings, such that in a worst case scenario, the accumulated trash becomes so large that the drain becomes plugged wholly or partially, and flooding in the area occurs when it rains.
In light of these issues, various attempts have been made to prevent trash from getting into drain. For example, in some places, a sizeable plate has been securely attached over the drain opening, leaving only a little space for water to flow. This solution does prevent much of the trash from entering into the drain, but it also prevents much of the water as well, and essentially defeats the purpose of the large drain opening that was intended to prevent flooding during heavy water run off. Therefore, other attempts have been made to design a storm drain gate that would remain closed during periods of low water run off, but which would automatically open in periods of heavy water run off. One recent example is U.S. Pat. No. 6,972,088, to Yehuda, in which a Pivotal Gate For A Catch Basin Of A Storm Drain System is disclosed. That invention uses a rather complex system involving a rotatable paddle wheel and interconnected wires that interplay to open the gate when sufficient water begins to flow into the drain. While it appears workable, this system may not be desirable for widespread installation given its complexity, which translates into higher initial cost and higher cost of upkeep. It is a given in any piece of machinery that the more moving and complex the component parts, the more costly to manufacture and install, and the more costly to maintain, and more likely to malfunction. Other prior art devices suffer from one or more of these drawbacks. as the design goals of simplicity, ease of installation, durability, low maintenance, and high effectiveness are difficult to achieve.
Therefore, there exists a need in the art for such a simple, effective gate system.
SUMMARY OF THE INVENTION
The preferred embodiments of the invention herein depicted and described provides such a device wherein the gate portion of the system that prevents trash from entering into the vault or drain basin is kept in the closed position by virtue of a trip plate that is rotatably attached to the back of the gate portion. In one preferred embodiment of the invention, the trip plate is attached to the back lower portion of the gate portion, and is biased (in one preferred embodiment by a spring) to closed position that is, substantially perpendicular to and extending rearwardly from the gate portion in one preferred embodiment. The trip plate is prevented from moving backward (that is, away from the gate), which in one preferred embodiment is accomplished by two pins extending from the plate into a groove formed in each of a pair of bracket assemblies that are attached to the drain basin wall. Thus, when there is no-flow or low-flow of water through the gate portion onto or against the trip plate, the plate stays in position and in turn keeps the gate portion in a closed position, flush against the drain basin opening. When the flow of water increases to a predetermined point, however, the water weight on the trip plate increases to the point where the biasing is overcome, and the trip plate rotates into an open position. This releases the gate portion and allows it to open. When the water flow onto the trip plate stops or reduces to a sufficiently low flow, the water weight on the trip plate is no longer sufficient to overcome the biasing on the plate, and it rotates back into its closed position, which in turn causes the gate portion to rotate downward into its “closed” position against the drain basin opening. Also disclosed and claimed are improved and alternative apparatus for attaching the system to the storm drain basin, and for controlling the location of the trip plate.
The preferred embodiments of this invention will now be depicted and described. As will be apparent to those skilled in the art, however, there are many different ways of attaching the various components of this system to the basin, and to one another, and of creating the biasing of the trip plate, and there are too many different ways to do so to list and describe here. Such common variants, even if not specifically described, are nonetheless considered to be within the scope of this invention.
DESCRIPTION OF THE FIGURES
FIG. 1 is an exploded, perspective view of one embodiment of this invention.
FIG. 2 is a partial side view of the preferred embodiment of this invention, showing the interplay between the gate, the trip plate and the guide brackets.
FIG. 3 is a perspective view showing one of the preferred embodiments of the gate system in its closed position within the opening of a curb drain basin.
FIG. 4 is a perspective, exploded view, showing the component pieces of an alternative embodiment of this invention.
FIG. 5 is a perspective, exploded view, showing in isolation one side of one embodiment of the invention.
FIG. 6 is similar to FIG. 5 , expect that the component pieces are shown assembled, with the exception that the lag bolt by which this bracket piece is attached to the drain basis is shown in exploded view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Looking at FIG. 1 , it is seen that this preferred embodiment of the invention is for attachment to the inside of a curb-side storm drain basin 10 , adjacent to and providing a cover for the opening 12 that leads from the basin 10 to the street 14 through the curb 16 . It should be noted, however, that while the device of this invention is believed to find primary utility in this application, and is why the title of this invention includes a reference to a storm drain, the invention herein described and claimed is a gate system that is not limited to that one application. The device of this invention could be usefully applied to any situation where it is desired to screen particulate matter from a fluid flow through an aperture during no-flow and low-flow conditions, but to remove the screen from the aperture during high-flow conditions.
The overall system consists primarily of a gate assembly 18 , the biased trip plate 20 , trip plate brackets 22 , and the various means by which these components are attached to one another, and to the side of the basin 10 . All components of this system are preferably constructed of 304 stainless steel. Other materials, however, could be used so long as they exhibited the required strength and durability appropriate for the application in which the system is used.
Although FIG. 1 shows in an exploded, perspective view how all of the various components are connected, the interplay of the gate assembly 18 , the biased trip plate 20 and the trip plate bracket assemblies 22 can best be seen in FIG. 2 . The gate assembly 18 comprises in this embodiment a gate portion constructed of a pair of gate plates 24 and 26 that are held together by any conventional means, in this instance by nuts and bolts 28 . Of course, there are a myriad of other ways to attach the two gate plates together, such as welding, gluing, screws, rivets, brackets, etc. Also, the gate portion of assembly 18 does not have to be constructed of multiple plates, and could be of unitary construction, or could be of many individual plates.
In this embodiment, the gate plate assembly 18 is rotatably attached to the basin 10 by means of a hollow tube 30 that is attached to the top of the gate assembly 18 , a pair of side pins 32 that are slidably housed within either end of the tube 30 and which are biased outwardly of the tube 30 by means of a spring 34 that is also housed within the tube 30 and forces the pins 32 outwardly. The distal end of the pins 32 engage appropriately-sized holes 33 in the large side brackets 36 and 38 (seen in FIG. 1 , not shown in FIG. 2 ), which are in turn attached to the side of the basin 10 by conventional means—in this instance, by bolts 40 that are set into appropriated-sized holes 42 the side wall of the basin 10 on either side of the opening 10 . As will be appreciated, this arrangement allows for easy attachment and free rotatability of the gate assembly 18 to the large side brackets 36 and 38 , as one of the pins 32 can be placed into one of the holes 33 , and then the other pin 32 can be pushed inwardly, the tube 30 brought into alignment with the other hole 33 , and that pin 32 then allowed to extend into that hole 33 so that the entire gate assembly 18 is now firmly yet rotatably attached into position against the opening 12 . As will be apparent, the attachment inter-relationship between these components can be adjusted to ensure that the gate 18 is properly positioned flushly against the opening 12 .
To provide the desired screening function, the gate plates 24 and 26 have a number of holes 42 extending therethrough. These holes can be of any desired shape, size, configuration and distribution as desired under the circumstances. For example and not in way of limitation, commercial mesh screens could be used under the appropriate circumstances.
Referring now back to FIG. 2 , it will be seen that the trip plate 20 is rotatably attached to the lower end of the gate assembly 18 . Here, the attachment means provided are a pair of pins 44 attached to the side of the trip plate 20 and which communicate with appropriately sized holes 46 in small brackets 50 that are attached to the gate assembly 18 via the same nuts and bolts 28 that are used to attached gates plates 24 and 26 together. It will be appreciated, however, that the manner in which the trip plate 20 is attached to the gate assembly 18 is not limited to the means showed, and can be accomplished by any other conventional method and means whereby the trip plate 20 is securely but rotatably attached such that the trip plate 20 can rotate from a first or closed position to a second or open position.
Again looking at FIG. 2 , the interaction between gate assembly 18 , the trip plate 20 and the side bracket assemblies 22 can best be appreciated. At the distal end of the trip plate 20 , a pair of outwardly extending pins 52 communicate with an arcuate groove 54 formed in each of the bracket assemblies 22 . In a no-flow or low-flow situation in which no or very little water is entering into the storm drain through the gate assembly 18 , the trip plate 20 is biased upwardly so that the pins 52 are pressed against the top of the grooves 54 . In this embodiment, the biasing of the trip plate 20 upwardly is accomplished by a pair of torsion springs 56 (seen only in FIG. 1 ). One end of the torsion springs resides in hole 58 in the side bracket 50 and the other end of the torsion spring resides in the hole 60 in the trip plate 20 . Again, this is only one of many ways in which the trip plate 20 can be biased into its closed position, and this invention is not limited to the one method and means shown.
In this preferred embodiment, the side bracket assemblies 22 , the grooves 54 and the side pins 52 are all arranged such that in that position, the trip plate 20 extends in a horizontal fashion directly behind and perpendicular to the gate portion (that is, gate plates 24 and 26 ) on the gate assembly 18 . Thus, in this position, the interplay between pins 52 within the bracket grooves 54 , and the bracket assemblies 22 (which are attached to the side wall of the basin 10 ) has the effect of holding the gate plates 24 and 26 in a vertical, closed position, flushly against the opening 12 in the drain basin 10 .
In this preferred embodiment, the trip plate 20 will hold the gate portion of gate assembly 18 in that position for so long as the water flowing through the basin opening 12 and onto the trip plate 20 is sufficiently small that the weight of the water bearing down on trip plate 20 is insufficient to overcome the upward biasing on the trip plate 20 caused by the torsion springs 56 . As the flow of water increases, however, and the resultant force of the water acting on trip plate 20 increases, the upward biasing is overcome, and the trip plate 20 begins to rotate in a downward direction, shown by arrow 62 . As this occurs, the trip plate 20 moves out of its horizontal, perpendicular alignment relative to the gate portion of gate assembly 18 , which in turn allows the gate portion of gate assembly 18 to begin to rotate in an upward direction as shown by arrow 694 , effectively enlarging the open space to allow more water to flow into the basin. It will also be noted that as the trip plate 20 rotates downwardly, the side pins 52 travel downwardly within the grooves 54 . In one embodiment of this invention, the grooves 54 are provided with one or more detents 66 (only one of which is shown in FIG. 2 ) which act as intermediate stopping points during the downward movement of the trip plate 20 . In other words, as the water flow onto the trip plate 20 increases and its starts to rotate downward, it will encounter one of the detents 66 . The pins 52 are forced into the detent, and will tend to reside there until the water weight increases incrementally until the pins 52 are forced out of the detents 66 . This will allow for staged opening of the gate assembly 18 , and will also work to prevent fluttering of the gate assembly as the water flow ebbs and increases. It will be appreciated that the size and depth of the detents 66 must be controlled so as to not unduly hinder the movement of the trip plate in either the downward or upward direction.
As the water weight continues to increase, eventually the biasing and the detents are overcome, and the trip plate 20 will rotate entirely downward (as shown in shadow in FIG. 2 ). At this point, the trip plate 20 ceases to exercise any limiting function on the gate assembly 18 , which in turn is allowed to rotate entirely open. By appropriate sizing and placement of the brackets 50 , the side pins 44 and the other components, the gate assembly 18 can be allowed to rotate through a full 90 degrees such that it comes to rest against the ceiling of the drain basis, in which case the storm drain opening 12 is complete unobstructed, maximum flow of water into the basis is allowed, and even trip plate 20 is pulled up substantially away from the water flow.
In this preferred embodiment, once the water flow recedes, the biasing on the trip plate 20 will again be greater than the water force acting on the trip plate, and it will again rotate into its closed position, simultaneously forcing the gate portion of gate assembly 18 downward and into its closed position flush against the basin opening 12 .
Referring back to FIG. 1 , it will been seen that the trip plate bracket assemblies 22 are attached to the large side brackets 36 and 38 by nut and bolts 70 to provide added stability to the interplay between the trip plate pins 52 and the grooves 54 , the ends of the pins 52 can be fitted with washers 72 and screws 74 to ensure that the pins 52 remain within the grooves 54 at all times, even if the trip plate 20 happens to be subjected to an uneven, torquing force that might otherwise cause the pins to become dislodged from the grooves. Lastly, the overall system can include side plates 76 that are attached to the large side brackets 36 and 38 by conventional nut and bolts 78 and a simple flanged element 80 that is attached to the side bracket 38 by conventional nut and bolt 82 , and which acts as a “stop” to prevent the gate assembly 18 from being pulled open in the direction of the street.
Referring now to FIG. 4 , an other alternative embodiment is shown. This embodiment can be utilized in a wide variety of drain basins where the curb-side openings are of different width. In this embodiment there is a gate assembly 100 that has a gate portion 101 that comprises a frame 102 to which is attached a mesh material 104 . In this instance, the mesh material 104 is a section of metal grate commercially available that has apertures of the desired size and shape depending on the particulate matter to be kept from entering the basin when the gate portion 101 is in the closed position (as is shown in the FIGS.). The mesh material 104 is attached to the frame 102 by any conventional means, such as by welding. The upper portion of the frame 102 is attached to rod 106 . As shown here, the frame 102 is welded to circular rod 106 , but any other attachment means could be utilized so long as the attachment is secure, fixed and durable.
The rod 106 extends through a pair of appropriately sized apertures 108 and 110 , respectively, in bracket assemblies 112 and 114 . The size of apertures 108 and 110 should be only slightly larger than the diameter of rod 106 so that rod 106 can rotate, and slide side-to-side within the apertures, but is otherwise held generally in place. The overall length of rod 106 will be dictated by the overall width of the basin opening to be covered.
The bracket assemblies 112 and 114 are designed and constructed to be attached to the horizontal portion 116 of the drain basin opening 12 (compare to the brackets 36 and 38 above, which are designed to be attached to the vertical interior wall of the basin). The bracket assemblies 112 and 114 are preferably mirror images of one another, and, as best seen in FIG. 5 , (the following description also applies to each) bracket assembly 112 has a base 118 to which a flange 120 is attached, and extends perpendicularly above the base 118 . In this preferred embodiment, flange 120 has an upper tab 122 that extends perpendicularly from the flange 120 . The tab 122 has a threaded orifice 124 into which a threaded bolt 126 is screwed. Bolt 126 is used to secure the bracket within the curb opening 12 as, once the bracket assembly 112 is properly position within the curb opening 12 , bolt 126 is screwed upward against the upper surface of the curb opening 12 , thereby creating a tension fit. Flange 120 also has a pair of horizontally elongated attachment slots 128 . The other main component of bracket assembly 112 is the adjustable guide 130 . Adjustable guide 130 has a series of vertically elongated slots 132 . Guide 130 is attached to flange 120 by conventional bolts 134 , washers 136 , lock washers 138 , and nuts 140 . The combination of the dual slots 128 and the multiple slots 132 allows for a large adjustment of the guide 130 to the flange 120 . As best seen in FIG. 6 , the bracket assembly 112 is preferable secured within the curb opening 12 by means of a set bolt 142 that extends through hole 144 and engages an anchor (not shown) that has been set into the concrete of the basin opening.
As best seen in FIG. 6 , the rear (relative to the curb) portion of guide 130 is designed such that it has a rearwardly extending hook 150 . It will be noted that detent 152 of the hook 150 extends downwardly a sufficient distance so that a pin (to be described below) will reside within the hook and will restrain the pin against force asserted against it in the rearward direction. Immediately below the detent 152 , the rearward edge 154 of guide 130 slants forwardly, toward the curb.
Referring now to FIG. 4 , the purpose of the guide 130 , detent 152 and rearward edge 154 will be described. As seen in this Figure, attached to gate assembly 100 is a trip plate 160 that is attached to and extends from the rear portion of the gate portion 101 by means of hinges 162 and 164 . Hinges 162 and 164 are preferably attached to the lower corners of gate portion 101 , and can be attached by any conventional means, including welding, screws, or bolts, for example (not shown). Each of the hinges 162 and 164 have a hinge pin 166 and 168 that extend inwardly towards one another from the hinges 162 and 164 . The hinge pins 166 and 168 communicate with appropriately sized holes 170 and 172 on the side arms 174 and 176 on trip plate 160 such that when so engaged, the trip plate 160 is securely held within, but is rotatable with respect to, the hinges 162 and 164 , and hence to gate portion 101 . As will be understood by those skilled in the art, circular springs 180 and 182 fits over hinge pins 166 and 168 , and the extending spring coil legs 184 and 186 fit into properly sized holes 188 and 190 that are formed in the trip plate arm 176 and hinge 164 respectively so as to bias the trip plate 160 into an upward orientation. As will be appreciated by those skilled in the art, the biasing force can be pre-determined by selecting the size and number of coils within the springs 180 and 182 .
The remainder of this embodiment of the trip plate 160 comprises a central trough 192 that extends between the sides arms 174 and 176 . Also in this embodiment, the trip plate 160 has a pair of plates portions 194 and 196 that extend upwardly and rearwardly from the trough 192 . It will be noted that the trough 192 in this embodiment does not extend at the way to the from of the side arms 174 and 176 . Rather, there is a void area between the arms 174 / 176 , the trough 192 and the gate 101 .
The trip plate 160 also has a pair of pins 200 and 202 that extend laterally from the rear portion of the side arms 174 and 176 . In this embodiment, each of the pins 180 and 182 are of two piece construction as shown. Various different constructions are of course possible. When the gate assembly 100 is fully assembled according to the attachment dotted lines in FIG. 4 , it will be noted that when the trip plate 160 is in its closed (as shown in this embodiment, upward) position (as biased by the springs 180 and 182 , the pins 200 / 202 will be forced upwardly within the detent 152 portion of hooks 150 in the two mirror image bracket assemblies 112 / 114 . The detent portions 152 of the hooks 150 are each sized and shaped relative to the size of pins 200 / 202 such that when the pins 200 / 202 are in position within the detent 152 portion of hooks 150 , the pins 200 / 202 cannot move in a rearward direction, such movement being retrained by the detent portions 152 . As will be appreciated, this interaction between the pins 200 / 202 and detent portions 152 will hold the gate portion 101 into place in the closed position against the drain basin opening. As a low flow of water comes through the mesh material 104 of gate portion 101 , the natural tendency of moving water to adhere to an adjacent surface will cause the water entering the drain basin opening 12 mainly to flow into the void space in front of the trip plate 160 . As the water flow increases, however, some of the water will start to flow onto the trip plate 160 before cascading into the drain basis. As the water flow increases, the amount of water that is instantaneously acting against the trip plate 160 will also increase until the upward biasing force of the springs 180 / 182 is overcome. At that point, the rear portion trip plate 160 will start to move downwardly, rotating upon hinge pins 166 / 168 . Once the rear portion of trip plate 160 has moved downwardly a sufficient amount, then pins 200 / 202 are freed from hooks 150 . At that point, the pins 200 / 202 no longer act to hold the gate portion 101 in a closed position against the drain basin opening, and the pressure of water on gate portion 101 will swing it widely and immediately open. As it does, the gate portion 101 rotates on rod 106 into an open position against to top of the drain basin. Once the flow of water has receded, the gate 101 will drop back into place and the pines 200 / 202 will be brought back into position with the hooks 150 .
As will be appreciated, the size and shape of the gate portion 101 , the mesh material 104 , the trip plate 160 , the detent 150 , and the strength of the biasing springs can be varied, so long as the resultant design works to open the gate portion 101 upon the desired flow of water. As will be appreciated, as the flow of water increases, more pressure is applied to the gate portion 101 , which applies more pressure by pins 200 / 202 against the detent portions 152 , so that will have to be taken into consideration. This is easily done by those skilled in the art. A representative embodiment is shown in FIG. 4 , which is drawn generally to scale.
The final aspect of this embodiment includes side panels 206 and 208 . These side panels 206 / 208 preferably have a similar frame and mesh material construction as gate 101 , and are sized and shaped so as to fully occupy the remainder of the basin opening 12 on either side of the gate 101 (as best seen in FIG. 3 ). In this embodiment, the upper portion of the panels 206 / 208 are attached to a tubular member 210 / 212 which is sized and shaped so as to fit snugly onto rod 106 . Once in place within the complete system, it will be seen that the backside of panels 206 / 208 rest against flanges 120 and are thus held into the closed position. As will also be appreciated, where this overall system is to be installed on a number of drain basin openings of varying widths, this embodiment can be utilized with a standard gate system 100 of common size, but with the ability to easily change the size of only three components in the overall system (that being the length of rod 106 , and the width of side panels 206 / 208 ) in order to accommodate a wide variety of basin opening widths.
Lastly, in order to provide some protection to the rod 106 , an L-bar 214 can be attached to the upper portion of the basin opening 12 .
Although preferred embodiments have been shown and described, the disclosed invention and the protection afforded by this patent are not limited thereto, but are of the full scope of the following claims, and equivalents thereto. | A gate system for an opening through which fluid flows, such as the opening to a storm drain typically found in the curb of an urban street. The system is biased to a closed condition to keep trash out of the drain during dry and low fluid flow situations, then automatically converts to an open condition during heavy fluid flow situations, and then returns to a closed condition when the heavy fluid flow condition abates. The system has a gate portion that rotates between an open position and a closed position adjacent the opening, being biased to the closed position, and a trip plate, which is also biased to a closed position. The trip plate has one or more pins that communicate with one or more grooves and/or detents in one or more adjacent bracket assemblies to hold the gate portion in the closed position until the fluid flow on or against the trip plate reaches a predetermined level such that the trip plate rotates from the closed position, releasing the gate portion and allowing the fluid flow to push the gate portion into an open position. After the fluid flow abates, both the gate portion and the trip plate rotate back to their closed positions automatically. | 4 |
RELATED APPLICATIONS
[0001] This application claims the benefit of United States Provisional Application No. 60/046,826 filed Apr. 24, 1997.
[0002] This application is a divisional application of U.S. patent application Ser. No.: 09/729,789, filed Dec. 4, 2000, which is a continuation in part of U.S. patent application Ser. No. 09/403,109, filed Oct. 14, 1999, now U.S. Pat. No. 6,273,316, which is the national stage of an International Application No. PCT/US98/08060 having an international filing date of Apr. 15, 1998. U.S. application Ser. No. 09/403,109, filed Oct. 14, 1999, also having been divided, resulting in U.S. application Ser. No. 09/875,488, filed Nov. 19, 2002, now U.S. Pat. No. 6,481,611.
FIELD OF THE INVENTION
[0003] The present invention relates generally to power actuated fasteners used in construction, and particularly to an automated power actuated fastener tool with track feeding.
BACKGROUND OF THE INVENTION
[0004] Power actuated guns are frequently used in construction. The power actuated guns are used to fasten building materials to a hard surface. Power actuated guns generally use a powder charge or a cartridge to drive a nail or a stud with great force into a hard surface, such as cement. Fasteners are often used that are comprised of a shaped plate with a nail or stud placed there through. Often, an angled plate having a hole therein is used so that a wire or other device can be fastened thereto. An example of a fastener which is used with a power actuated gun is disclosed in U.S. Pat. No. 4,736,923 entitled “Fastener Assembly” issuing to Losada on Apr. 12, 1988, which is herein incorporated by reference. Power actuated fastener guns have been used in combination with the fastener assemblies. The stud or nail of the fastener assembly is placed within the barrel of the power actuated gun and placed adjacent a hard surface. The power actuated gun is then fired driving the stud or nail into the hard surface. Often, the fasteners will be used in ceiling applications with the power actuated gun being placed on a pole, the fastener assembly being inserted within the bore of the power actuated gun and the whole device raised to the ceiling with the pole. When pressure is applied to the pole, the power actuated gun fires, driving the nail or stud into the hard surface. The power actuated gun is then lowered for insertion of another fastener assembly. Often, it is also necessary to cock the gun or to advance the powder charge to render the gun operable for another firing. While this operation is satisfactory for many applications, it also requires a great deal of time to manually load each fastener assembly prior to firing the power actuated gun. Therefore, there is a need to improve and make more productive the use of power actuated guns and fastener assemblies so as to increase their efficiency and make each worker more productive. Increases in productivity are essential in the construction field where ever escalating labor costs make it essential that each worker as productive as possible. Therefore, there is a continuing need to increase the productivity of each worker and to automate the construction process as much as possible. One system that has greatly advanced the power actuated gun art is disclosed in U.S. patent application Ser. No. 09/403,109 filed Oct. 14, 1999 and entitled “Fastener Feeding System For Power Actuated Gun” invented by Losada, which is herein incorporated by reference. While this device has dramatically improved the productivity of workers, there is a need for yet further improvement.
SUMMARY OF THE INVENTION
[0005] In one embodiment of the present invention, a feeding system for use with a power actuated gun comprises a track to hold a plurality of fastener assemblies having guides for positioning a fastener assembly over a surface and to be received by the barrel of a power actuated gun. Once in position and held by the guides, the power actuated gun is moved relative to the feeding system, causing the guide to release the fastener assembly and the fastener assembly to be driven into a surface upon the firing of the power actuated gun.
[0006] In another embodiment of the present invention, a fastener loading control is used to prevent a fastener assembly adjacent the fastener assembly in position for firing from advancing prematurely.
[0007] In another embodiment of the present invention, the relative movement between the power actuated gun and an attachment is used to control various operations of the power actuated gun. In one embodiment, the relative movement is used to advance the charge on a strip, making the power actuated gun ready for another firing. In another embodiment, the relative movement is used to activate a trigger so as to fire the power actuated gun when the fastener assembly is in position.
[0008] In another embodiment, a stop is used to prevent the power actuated gun from firing when a fastener is not in position.
[0009] Accordingly, it is an object of the present invention to make laborers or workers more productive and thereby reduce construction costs.
[0010] It is another object of the present invention to provide a power actuated fastening system that has a smooth operation and is easy to use.
[0011] It is a further object of the present invention to use the relative movement between a power actuated gun and an attachment to automate various functions.
[0012] It is a further object of the present invention to provide a power actuated fastener system that is safe to use.
[0013] It is an advantage of the present invention that it saves time.
[0014] It is a further advantage of the present invention that the relative movement between the power actuated gun and an attachment is used to automate many different functions.
[0015] It is another advantage of the present invention that the power actuated gun cannot be fired unless a fastener assembly is in the proper firing position.
[0016] It is a feature of the present invention that a track holds a plurality of fastener assemblies.
[0017] It is a further feature of the present invention that a fastener loading control prevents the advancement of a fastener assembly within the track until the adjacent fastener assembly is cleared.
[0018] It is another feature of the present invention that a rod and spring provides relative movement between the power actuated gun and an attachment.
[0019] It is yet another feature of the present invention that a stop is used to prevent the firing of the power actuated gun without a fastener assembly being in the proper firing position.
[0020] These and other objects, advantages, and features will become readily apparent in view of the following more detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective view of an embodiment of the present invention.
[0022] FIG. 2 is a side elevational view of an embodiment of the present invention.
[0023] FIG. 3A is a partial cross section of an embodiment of a fastener loading control in a first position.
[0024] FIG. 3B is a partial cross section of an embodiment of a fastener loading control in a second position.
[0025] FIG. 3C is a plan view of an embodiment of the present invention.
[0026] FIG. 4A is a partial cross section of another embodiment of a fastener loading control.
[0027] FIG. 4B is a partial perspective view of the fastener loading control embodiment illustrated in FIG. 4A .
[0028] FIG. 5A is a partial cross section of another embodiment of a fastener loading control.
[0029] FIG. 5B is a partial perspective view of the fastener loading control embodiment illustrated in FIG. 5A .
[0030] FIG. 6A is a perspective view of a portion of another embodiment of the present invention.
[0031] FIG. 6B is a cross section taken along line 6 B- 6 B in FIG. 6A .
[0032] FIG. 7A is a partial cross section of another embodiment of the present invention illustrating the operation of a firing safety device in a first position.
[0033] FIG. 7B is a cross section of a portion of an embodiment of the present invention illustrating the firing safety device illustrated in FIG. 7A in a second position.
[0034] FIG. 8 is a partial elevational view of an embodiment of the present invention illustrating a charge advancing control mechanism.
[0035] FIG. 9 is a side elevational view of a portion of the present invention illustrating the charge advancing control /mechanism illustrated in FIG. 8 .
[0036] FIG. 10A schematically illustrates an embodiment of the present invention and the charge advancing control mechanism in a first position. FIG. 10B schematically illustrates the operation of the embodiment of the present invention and the charge advancing control mechanism in a second position.
[0037] FIG. 10C schematically illustrates the operation of the embodiment of the present invention and the charge advancing control mechanism in a third position.
[0038] FIG. 11A more clearly illustrates the operation of the charge advancing control mechanism in another first position.
[0039] FIG. 11B more clearly illustrates the operation of the charge advancing control mechanism in another second position.
[0040] FIG. 11C more clearly illustrates the operation of the charge advancing control mechanism in another third position.
[0041] FIG. 11D more clearly illustrates the operation of the charge advancing control mechanism in another fourth position.
[0042] FIG. 12A schematically illustrates the operation of a trigger control mechanism in a first non-firing position.
[0043] FIG. 12B schematically illustrates the operation of the trigger control mechanism in a second firing position.
[0044] FIG. 13 schematically illustrates an embodiment of the present invention having a curved fastener feeding track.
[0045] FIG. 14 schematically illustrates in an exploded view another means for moving the gun relative to an attachment or track.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] FIG. 1 illustrates an embodiment of the present invention. A power actuated gun or tool 10 is illustrated. The power actuated gun 10 may be based on any commercially available power actuated gun. Generally, there are several different types of operation of power actuated guns. For example, some power actuated guns may have to be cocked, some may fire when pressure is applied to the rear of the gun, some may require the pulling of a trigger to fire the gun, and some may require the charge to be manually advanced. The present invention may be adapted to any of a variety of these commercially available power actuated guns. Additionally, many power actuated guns may be modified in accordance with the teachings of the present invention in order to improve the power actuated gun. A fastener feeding track 12 is attached to the body of the power actuated gun 10 so as to be positioned over a barrel 11 . The fastener feeding track 12 contains a plurality of fastener assemblies comprising a fastener plate 14 with a nail or a stud 16 A frictionally fastened to the fastener plate 14 though an aperture formed therein. A fastener assembly placed within a channel in the fastener feeding track 12 is advanced forward into a position over the barrel 11 . A rear guide 18 is made of a spring metal that holds a portion of a positioned fastener plate 14 A. A side guard 20 also made from spring steel contacts a side of the positioned fastener plate 14 A, holding it into position over barrel 11 . Guides 18 and 20 only illustrate one means for holding the fastener assembly in position. A fastener loading control 22 is positioned adjacent the fastener assembly plate 14 A in position over the barrel 11 and is used to control the loading of the next adjacent fastener assembly plate 14 into position once the gun 10 is fired. The fastener assembly loading control 22 prevents an adjacent fastener assembly plate 14 from prematurely advancing into position before the barrel 11 of the power actuated gun is in position to receive another fastener assembly. Lever 24 having a coiled spring attached, not shown, biases the plurality of fastener assembly plates 14 down the track 12 , forcing the fastener assemblies into position sequentially over the barrel 11 . The track 12 comprises a channel piece 26 with an angled piece 28 . An opening 30 is formed within the angled piece 28 . A radius slide 32 is attached to the channel piece 26 and aids in the sliding of the plates 14 along the track 12 . A support plate 34 has a spacer plate 36 attached thereto. Formed on the spacer plate 36 and the support plate 34 are feet 38 . Contact 21 , forming a part of the fastener loading control 22 , may also act as a support or foot so as to provide three points of contact when the track 12 is placed adjacent a surface. A short rod 40 A has a spring 42 surrounding it. Short rod 40 A is slidably held within a collar 44 . Short rod 40 A has an end fixed to the support plate 34 . A long rod 40 B is attached to another portion of the track 12 and similarly has a spring 42 . One end of the long rod 40 B is slidably attached to collar 44 . The distal end of the long rod 40 B is attached to a control mechanism 41 . The positioning of the track 12 and the tension within the spring 42 may be adjusted by axially sliding collar 44 on the body of the power actuated gun 10 . The position of the collar 44 may be locked into place by set screw 46 . A fixed handle 48 contains therein a charge strip 50 . Charge strip 50 contains a plurality of powder charges that are used to drive the fastener assembly. A charge advance lever 52 is pivoted by pivot 49 and is used to advance the charge strip 50 . From FIG. 1 , the general operation of this embodiment of the present invention should be appreciated. A plurality of fastener assemblies, including plate 14 , are inserted through opening 30 and slid down the channel piece 26 while lever 24 is drawn rearward or away from the barrel 11 of the power actuated gun 10 . After a plurality of fastener assemblies have been inserted through opening 30 and slid down the track 12 , lever 24 may be released causing an end plate, not illustrated, to contact the last fastener assembly, forcing it against adjacent fastener assemblies until a fastener assembly is placed in a firing position adjacent the support plate 34 . The guides 18 and 20 retain the fastener assembly in the firing position. After placing the track 12 adjacent a surface through which the fastener assembly is to be driven, the power actuated gun is forced upward or towards the track 12 so as to cause the stud 16 A to enter the barrel 11 . The plate 14 A, it is pushed through the guides 18 and 20 so as to cause the fastener assembly to be securely forced against the surface into which it is to be driven. The application, in this particular power actuated gun, of additional force causes the gun to automatically fire. Upon release of pressure from the rear of the power actuated gun 10 , the springs 42 cause the barrel 11 to move away from the track assembly 12 . However, the fastener loading control 22 prevents a fastener assembly from advancing within the channel piece 26 until after the barrel 11 is withdrawn a sufficient distance and the contact 21 and feet 38 are removed a predetermined distance from the surface. The control mechanism 41 then causes the lever 52 to be depressed, advancing the charge strip 50 . The gun is now ready for another firing with another fastener assembly secured positioned in a firing position.
[0047] FIG. 2 more clearly illustrates the track 12 and the fastener loading control 22 . The plurality of fastener assemblies have a plurality of shaped plates 14 that abut one another. Additionally, wires 17 are shown attached to plates 14 . A particularly prevalent application of power actuated guns is to hang wire assemblies from ceilings, such that objects may be attached to the wires 17 and suspended or supported, for example a suspended ceiling. Guides 18 and 20 hold plate 14 A of the fastener assembly into position over barrel 11 . Plate 14 B of adjacent fastener assembly is held in position by fastener loading control 22 . The fastener loading control 22 comprises a contact 21 which is positioned adjacent a surface, forcing it toward the angled plate 28 and fastener plate 14 B. Spring 23 normally biases the contact 21 away from the top surface of the angled plate 28 . A screw 25 holds one end of the spring 23 onto a surface of the angled plate 28 while the distal end of the spring 23 has contact 21 attached thereto. Accordingly, the adjacent fastener assembly having plate 14 B is prevented from advancing until spring 23 biases contact 21 upward to release the plate 14 B. This assures that the plate 14 B is not advanced until after the barrel 11 is retracted or biased away from the channel 26 by springs 42 . Only after barrel 11 is sufficiently clear is the plate 14 B released to advance into a firing position.
[0048] FIGS. 3A and 3B more clearly illustrate the operation of the fastener loading control 22 . As the track 12 is placed adjacent a hard surface 54 and the distance d, between the foot 38 and the hard surface 54 is reduced, the contact 21 also contacts the hard surface 54 causing extension 27 downward towards stud 16 B. As the extension 27 moves downward, the point of stud 16 B enters space 29 within the extension 27 . Accordingly, when distance d 1 between the surface 54 and the foot 38 is reduced and the foot 38 contacts the surface 54 , the distance d 2 between barrel 11 and the surface 54 is then reduced and the barrel 11 advances. Accordingly, as is illustrated in FIG. 3B , as the track 12 moves in the direction of arrow 1 and the foot 38 contacts the surface 54 , the outer barrel 11 A contacts plate 14 A, stripping the plate 14 A from the guide 20 . The extension 27 engulfs the point of shaft 16 B, securely holding t adjacent plate 14 B in position. After the fastener assembly and plate 14 A are firmly against surface 54 , the inner plunger 11 B is forced downward in the direction of arrow 3 by an explosive charge so as to drive the stud 16 A within the hard surface 54 . After firing, the inner plunger 11 B and the outer barrel 11 A are withdrawn away from the surface 54 . Once the barrel 11 is withdrawn a sufficient distance and the power actuated gun is continued to be withdrawn from the surface 54 such that a gap forms between the surface 54 and foot 38 , the contact 21 will then be biased upward or away by spring 23 , causing release of the adjacent stud 16 B. Once the stud 16 B is released, the adjacent fastening assembly and the plate 14 B is advanced to the firing position over barrel 11 .
[0049] FIG. 3C is a plan view illustrating the surface of the track 12 and the holding of plate 14 A. Plate 14 A of the fastener assembly can clearly be seen in a position held by guides 18 and 20 and an adjacent fastener assembly having plate 14 B. The fastener loading control 22 can also more clearly be seen. Each plate 14 advances the adjacent plate 14 down the track 12 as respective fastener assemblies are driven into a surface with the power actuated gun.
[0050] FIGS. 4A and B illustrate another embodiment of a fastener loading control. In this embodiment, when a surface 54 contacts contact 121 forcing an extension 127 downward, the extension 127 is forced between plate 14 A and adjacent plate 14 B. Accordingly, plate 14 B is prevented from moving toward the firing position until after the biasing force in spring 123 forces the contact 121 away from the fastener assemblies as the track is removed from the surface 54 .
[0051] FIGS. 5A and B illustrate another embodiment of a fastener loading control. In this embodiment, surface 54 forces a block extension 227 adjacent portions of plate 14 B as track 212 is placed in position adjacent surface 54 . Friction then retains the plate 14 B in position, preventing it from advancing forward as the fastener assembly and plate 14 A are driven into surface 54 . Upon removal of the track 212 from the surface 54 , the biasing force in spring 223 forces the block extension 227 away from the track 212 and thereby releases the fastener assembly having plate 14 B. The plate 14 B is then free to advance into the firing position. Clearly, other equivalent fastener loading control devices are possible. For example, each fastener plate may have hole therein through which an extension can be inserted preventing unintentional movement of the fastener plate.
[0052] FIGS. 6A and B illustrate another guiding mechanism used in holding plate 14 A of a fastener assembly in a firing position over barrel 11 . In this embodiment, a support plate 134 houses a cam driven side guide 120 . Support plate 134 is attached to a spacer plate 136 , which has a foot 138 thereon. A rear guide 118 holds the angled portion of plate 14 A. FIG. 6B is a partial cross section taken along line 6 B- 6 B in FIG. 6A . FIG. 6B more clearly illustrates the operation of the cam driven side guide 120 . A spring 156 forces a guide slide 158 towards plate 14 A. Stop 162 prevents the guide slide 158 from being forced out of the support plate 134 . Accordingly, when plate 14 A is in a firing position, it is retained between the guide 120 and an adjacent plate 14 B. As the barrel 11 is moved adjacent the plate 14 A in the direction of the arrow on barrel 11 , nail or stud 16 A enters the barrel 11 and a corner of barrel 11 contacts cam surface 160 on the guide slide 158 . The guide slide 158 is forced in the direction of the arrow on the guide slide 158 against the bias force of spring 156 . The guide 120 is then caused to release the plate 14 A while the stud 16 A is securely retained within the barrel 11 . The plate 14 A of the fastener assembly is then free to be moved against the surface 54 and driven therein.
[0053] FIGS. 7A and B illustrate a safety stop designed to prevent the power actuated gun from firing should a fastener assembly not be placed in a firing position. Many power actuated guns have a safety feature such that if a portion of the barrel, for example an inner portion 13 , does not contact a sufficiently hard surface, a safety mechanism within the power actuated gun will cause the gun not to fire. Generally, this prevents the gun from firing unless the barrel is placed against a solid surface. However, in most applications, the barrel can be placed against a solid surface without a fastener assembly placed therein and the power actuated gun will still be able to fire. This may result in a dangerous firing of the gun, damage to the plunger of the gun, and at the least a waste of a charge. The embodiment illustrated in FIGS. 7A and B provide a safety feature associated with a track so as to prevent the firing of a power actuated gun should a fastener assembly not be in a firing position. In FIG. 7A , a track is illustrated with a foot 238 placed adjacent a hard surface, not illustrated, and the outer barrel 11 A being advanced with an inner safety barrel 13 forced against the plate 14 A. The outer barrel 11 A is allowed to continue to advance, placing sufficient force on the inner safety barrel 13 A to cause the power actuated gun to fire. The fastener plate 14 A pushes a detection leg 259 of a stop slide 258 compressing spring 256 . The stop leg 261 is therefore clear of the outer barrel 11 A. FIG. 7B illustrates operation of the safety feature when a fastener assembly is not positioned in the firing position. When a fastener assembly is not positioned in the firing position, the absence of a plate 14 A, illustrated in FIG. 7A , causes the detection leg 259 to move forward or towards the barrel 11 A due to the bias of spring 256 . The stop leg 261 therefore is moved into position so as to strike the outer barrel 11 A as it is advanced in the direction of the barrel on 11 A. The stop leg 261 prevents any further advancement of the outer barrel 11 A. Accordingly, the inner safety barrel 13 does not contact a hard surface preventing the power actuated gun from firing. Therefore, should the fastener assembly supply run out of the track or should a fastener assembly not be in a firing position for any reason, the safety device illustrated in FIGS. 7A and B will prevent the power actuated gun from firing. Other equivalent safety devices may be used to prevent the unintentional firing of the power actuated gun. For example a stop may be place at other locations. Additionally, it should be appreciated that the present invention is inherently safer than prior individually hand loaded power actuated guns. By providing automated feeding the risk of injury to an operator during loading of the barrel directly is substantially reduced or eliminated. Should the power actuated gun misfire during loading, serious injury could result.
[0054] FIGS. 8 through 11 illustrate the operation of a control mechanism 41 that takes advantage of the relative movement between a track 12 and the power actuated gun 10 . Sliding rods 40 A and 40 B and springs 42 permit relative movement between an attachment to the power actuated gun 10 and the power actuated gun 10 . Long rod 40 B may be attached to a control mechanism 41 . Generally, the control mechanism 41 may be used to operate any feature of a power actuated gun. However, in this embodiment, the control mechanism 41 operates a charge advancing lever 52 used to advance a charge strip 50 . The charge advancing lever 52 has a tab 51 thereon which contacts the charge strip 50 . The lever 52 is pivoted at one end by pivot 49 . A cam 57 forms a part of the control mechanism 41 and activates or depresses lever 52 .
[0055] FIG. 9 is a partial cross section taken along line 9 - 9 in FIG. 8 . FIG. 9 more clearly illustrates the operation of the control mechanism 41 . A spring 53 is attached to charge advance lever 52 , biasing the charge advance lever 52 away from the body of the power actuated gun 10 . The cam 57 fits in an opening within a fork of the lever 52 . A stop 59 prevents the cam 57 from pivoting on pivot 55 .
[0056] FIGS. 10 A-C schematically illustrate the general operation of the control mechanism 41 and its use advancing a charge strip 50 readying the power actuated gun 10 for a subsequent firing. In FIG. 10A , the power actuated gun 10 is moved forward, causing a fastener assembly in the firing position to be forced against the surface 54 . Springs 42 are compressed and the power actuated gun may be fired. This embodiment of the power actuated gun 10 is fired when continuous pressure is applied to the rear of the power actuated gun 10 and the barrel of the power actuated gun 10 is adjacent a hard surface. This embodiment of the power actuated gun 10 is often used on the end of a pole when applying fastener assemblies to a ceiling. However, this embodiment of the power actuated gun requires the charge strip 50 to be advanced to provide sequential firing of the power actuated gun 10 . The control mechanism 41 uses the relative motion between the power actuated gun 10 and a track 12 to automate the advancing of the charge strip 50 . This makes it unnecessary to bring the power actuated gun 10 down from the end of a pole when the power actuated gun 10 is used in applying multiple fastener assemblies to a ceiling. FIG. 10B illustrates the operation of the control mechanism 41 after a fastener assembly is driven into surface 54 . The springs 42 providing a relative movement between the power actuated gun 10 and a track 12 . The bias of the springs 42 move the power actuated gun 10 and handle 52 away from the track 12 . The cam 57 is forced upward by the stop 59 , resulting in the handle 52 being compressed against the body of the power actuated gun 10 as illustrated in the direction of the arrow adjacent the lever 52 . The charge strip 50 is thereby advanced as illustrated by the arrow adjacent strip 50 . FIG. 10C illustrates operation of the control mechanism 41 when a new fastener assembly is placed in a firing position and the power actuated gun 10 is moved closer to the track 12 compressing springs 42 . As the power actuated gun 10 and the attached lever 52 are moved closer to the track 12 , the cam 57 is caused to pivot counterclockwise on pivot 55 away from stop 59 . The cam 57 slides along the surface of lever 52 . Accordingly, lever 52 is not compressed towards the body of the power actuated gun 10 . Therefore, the charge strip 50 is not advanced while the barrel of the power actuated gun 10 pushes another fastener assembly away from the track and against the surface 54 .
[0057] FIGS. 11 A-D more clearly illustrate the operation of the control mechanism 41 . FIG. 11A illustrates the control mechanism 41 in a resting position. The cam 57 extends through an opening in the lever 52 . Advancing tab 51 is in position adjacent the charge strip 50 . Spring 53 biases the lever 52 away from the body of the power actuated gun 10 . FIG. 11B illustrates the operation of the control mechanism 41 as the power actuated gun 10 is moved to the left or in the direction of the arrow on the body of the power actuated gun 10 . As the handle 52 is moved with the power actuated gun 10 in the direction of the arrow on the body of power actuated gun 10 , the control mechanism 41 attached to the long rod 40 B remains stationary. As a result of the contact between the lever 52 and the cam 57 ,. the cam 57 is pivoted counterclockwise on pivot 55 away from stop 59 . FIG. 11C illustrates the full advancement of the power actuated gun 10 and the attached lever 52 with the cam 57 having sufficient clearance with the angled lever 52 so as not to depress the lever 52 or compress spring 53 . During the movement illustrated by FIGS. 11 A-C, the lever 52 has not moved resulting in no advancement of the charge strip 50 . FIG. 11D illustrates operation of the control mechanism 41 as the power actuated gun 10 is moved in the direction of the arrow illustrated on the body of the power actuated gun 10 . As the attached lever 52 is moved in the direction of the arrow on the body of the power actuated gun 10 , cam 57 is forced clockwise against stop 59 . This causes the lever 52 to pivot toward the body of the power actuated gun 10 and compressing spring 53 . The advancing tab 51 is caused to move with the lever 52 resulting in the charge strip 50 to advance in the direction of the arrow adjacent charge strip 50 . Accordingly, in this embodiment of the present invention, the relative motion between an attachment to a power actuated gun, for example a track, and the power actuated gun, results in the ability to control or activate different features on the power actuated gun. Other equivalent features of the power actuated gun may be controlled with the motion created by the power actuated gun.
[0058] FIGS. 12 A-B illustrate another type of control mechanism that may be utilized as a result of the relative movement between a track and a power actuated gun. In some power actuated guns, an external trigger must be activated before the gun will fire. In power actuated gun applications utilizing a pole to elevate the power actuated gun to a ceiling, a wire is sometimes used connected to a trigger to fire the gun from a ground location. However, this is often inconvenient and requires the operator to pull a wire mechanism to fire the gun. The embodiment illustrated in FIGS. 12 A-B provides a trigger control mechanism that automates the firing of a power actuated gun 310 . The power actuated gun 310 has a trigger 364 which must be activated or depressed in order to fire. This embodiment of the power actuated gun 310 may also have a charge advance mechanism 341 , similar to that previously illustrated in greater detail. A control rod 368 is attached to a track 312 containing a plurality of fastener assemblies having plates 14 . A plunger or activator 370 is attached to the trigger control rod 368 . The plunger or activator 370 may be spring loaded to the trigger control rod 368 . However, the spring must be sufficiently strong or provide a force greater than that necessary to activate the trigger 364 . This assures that any slight variances in distance or travel will not result in a gap between the plunger or activator 370 and the trigger 364 , resulting in the power actuated gun 310 not to fire. FIG. 12A illustrates the position of the power actuated gun 310 prior to advancing the power actuated gun 310 towards the track 312 and against the surface 54 . FIG. 12B illustrates the positioning of the power actuated gun 310 moved upward adjacent the surface 54 so as to compress springs 342 . Accordingly, a fastener assembly is stripped from the track 312 and caused to abut surface 54 . The trigger is then activated by the plunger 370 causing the power actuated gun 310 to fire. Accordingly, the embodiment illustrated in FIGS. 12 A-B can fully automate the firing of a power actuated gun 310 of the type having a trigger 364 . Therefore, in combination with the track 312 and control mechanisms 341 and 366 , the power actuated gun 310 may be repeatedly fired without having to lower and adjust or feed the power actuated gun 10 . Therefore, when the power actuated gun 310 is placed on a pole and used in a ceiling application, the power actuated gun 310 does not have to be lowered for insertion of a new fastener assembly, advancement of the charge, and a separate lever or cable pulled once in position to fire. The present invention therefore greatly facilitates the rapid firing of multiple rounds or charges to very rapidly sequentially drive fastener assemblies.
[0059] FIG. 13 illustrates another embodiment of a power actuated gun 410 having a control mechanism 441 and a curved track 412 . The curved track 412 operates substantially similarly to the previously described linear tracks in holding plates 14 of a fastener assembly. However, the curved track 412 makes the power actuated gun 410 more compact and permitting the invention to fit in tighter places than if the track was not curved.
[0060] FIG. 14 illustrates another embodiment of a power actuated gun 510 showing a different means for moving a track 512 relative to the power actuated gun 510 . A single concentric spring 542 may be placed over the barrel of the power actuated gun 510 and within a single cylinder attached to a track 512 .
[0061] Accordingly, it should be appreciated that the present invention may encompass a variety of different embodiments, only several of which have been illustrated in detail. It will be clear that the principles of the present invention can be applied to many different structures without departing from the spirit and scope of the invention. The present invention provides the automation of a power actuated gun that saves considerable time. Fastener assemblies can rapidly be positioned and driven with the worker or operator taking virtually no time between firing to reload a fastener assembly or advance the charge. | An automated power actuated gun having a fastener feeding track with guides for holding a fastener assembly having a plate and attached stud in a firing position. The power actuated gun is attached to the fastener feeding track so as to permit relative movement there between. A fastener loading control prevents movement of an adjacent fastener assembly held within the fastener feeding track from moving until the barrel of the power actuated gun is clear. The relative movement between the fastener feeding track and the power actuated gun is utilized to activate a control mechanism to perform various functions on the power actuated gun, such as to advance a charge or to push a trigger firing the power actuated gun. The functioning of the power actuated gun is automated, greatly increasing productivity of a worker and eliminating the need of the worker to tediously load by hand and fire individual fastener assemblies. | 1 |
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61,365,218 filed Jul. 16, 2010, and is a continuation-in-part of U.S. patent application Ser. No. 12/557,316, filed Sep. 10, 2009.
FIELD OF THE INVENTION
[0002] A combination of organic additives to organic electronic devices is formulated selected from organic moisture getters, hybrid organic/inorganic additives (such as silanes) to remove moisture, radical scavengers, antioxidants, UV stablizers, and photoretarders. The formulation improves operating lifetimes of organic electronic devices such as light emitting devices using polymer-based electroluminescent ink, non-polymer light-emitting devices, and organic photovoltaics, transistors and sensors.
BACKGROUND
[0003] Electroluminescent polymers are materials that emit light when sandwiched between two suitable electrodes and when a sufficient voltage is applied. A number of electroluminescent devices have been disclosed which use organic materials as an active light-emitting layer sandwiched between two electrodes. For example, VanSlyke et al. in U.S. Pat. No. 4,539,507 disclose a device having a bilayer of two vacuum-sublimed films of small organic molecules sandwiched between two contacts. The small organic molecules however are not printable using a solution-based process. In a related patent, Friend et al. in U.S. Pat. No. 5,247,190, disclosed a device having a thin dense polymer film made up of at least one conjugated polymer sandwiched between two electrodes. Subsequently, Braun at al. in U.S. Pat. No. 5,408,109 showed that high brightness light emitting devices could be made using soluble electroluminescent polymers. Their results indicated that it may be possible to make light emitting displays using inexpensive solution-based atmospheric processing techniques, such as ink jet printing, reel-to-reel or screen printing; however, efficient device operation required the use of low work-function metals, such as Ca, that are not stable under atmospheric processing (i.e. printing) conditions.
[0004] Pei et al. describe a polymer light-emitting electrochemical cell (U.S. Pat. No. 5,682,043) which contains a solid state electrolyte and salt that is used to electrochemically dope an organic electroluminescent layer, such as a conjugated polymer, via ionic transport. This system provides the ability to achieve efficient device operation without relying on the use of low work-function metals. Following this work, Cao showed in U.S. Pat. Nos. 5,965,281 and 6,284,435 that organic anionic surfactants cause a similar effect without needing ionic transport through the polymer film. The patents described in this paragraph disclose many anions and cations that are useful in the present invention, and their disclosures are incorporated herein by reference. In theory, electrochemical doping or anionic surfactants could be used to make an electroluminescent polymer device that would be fully compatible with liquid-based processing under atmospheric conditions. Nonetheless, the electroluminescent polymer solutions mentioned in these patents are not easy applicable to many fully liquid-based manufacturing process, such as screen printing and gravure, and also have limited lifetimes.
[0005] Screen printing is one of the most promising methods to inexpensively manufacture large-area electroluminescent displays. Screen printing has been successfully applied to manufacturing large area inorganic phosphor-based electroluminescent displays by Topp et al. in U.S. Pat. No. 4,665,342. Victor et al. later showed that screen printing, and related printing techniques, can be used to manufacture polymer-based electroluminescent displays (U.S. Pat. No. 7,115,216) using a fully printable cathode. Carter et al. (U.S. Pat. No. 6,605,483) revealed a method to make a printable electroluminescent ink that improves the screen printability and performance of electroluminescent polymer solutions through the use of soluble or dispersible additives, such as gel retarders, high boiling point solvents, and ionic dopants. More recently, flexographic, gravure, capillary, nozzle, slot and spray deposition techniques have been employed to deposit organic electronic inks in similar structures including electroluminescent, photovoltaic and sensing devices. Nonetheless, these inks still suffer form lower lifetimes when fully printed.
SUMMARY OF THE INVENTION
[0006] The invention is described below with respect to polymer-based electroluminescent inks. The invention is equally applicable to other organic and solution processible electronic devices, such as charge transporting and light emitting devices based on organic semiconductor materials, non-polymer light-emitting devices, organic photovoltaics, transistors, and sensors.
[0007] The development of novel polymer luminescent ink which can be printed and utilized in electroluminescent devices with long lifetimes is desired. There are several factors that limit lifetime. However, the presence of oxygen and water in the polymer-containing film and the formation of free radicals during device operation play critical roles as they can induce reactions within the film which subsequently degrade the active materials.
[0008] Novel polymer luminescent ink formulations containing additives are used to improve the lifetimes of electroluminescent devices fabricated from polymer luminescent ink. These additives include moisture getters, thermally-activated organic/inorganic hybrids, radical scavengers, antioxidants, UV stabilizers, and photoretarders. In some cases these additives or organic or organic functionalized materials allow compatibility with the semiconductor medium or solubility in the solution ink phase. The basic requirements for being a good additive include compatibility with the luminescent polymer, miscibility with organic solvents, and efficient reaction with water, oxygen, hydrogen, or free radicals. This reaction can include transformation or sequestration of unwanted species into an inert form or a less reactive state, or they may include transformation of the unwanted species into a more volatile form or different solubility form so that they can be more easily eliminated from the active layer films. In each of these cases, for water and oxygen scavengers, activation at elevated temperatures (e.g. 40° C. to 200° C.) is preferred. This allows for the handling of the device materials containing the scavengers under a lower temperature condition where higher levels of ambiently-supplied water or oxygen may also be present. At some later point, the device material containing the scavenger can be activated. This prevents unnecessary saturation or consumption of the scavenger prior to the time the scavenging step is actually needed, such as after a device is hermetically sealed or encapsulated or when the device actually needs to be electrically activated for its intended use.
[0009] In the present invention, an organic moisture getter is used to react with residual water in the light-emitting polymer film during thermal annealing to remove it from reacting with the active materials. Some hybrid organic/inorganic additives, such as silanes, are also used to remove moisture through an hydrolysis process upon heating. In addition, radical scavengers are added to capture reactive radicals before they attack the light emitting polymer. Finally, antioxidants, UV stabilizers, and/or photoretarders are used as sacrificial agents to react with oxygen and light, respectively. Here, we demonstrate that when these additives are incorporated into the light emitting polymer layer, the electroluminescent devices containing this layer have improved lifetimes.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 shows device performance of formulation A with no additives (Example 1).
[0011] FIG. 2 shows device performance of A with the moisture getter additive of Scheme 1 (Example 2).
[0012] FIG. 3 shows device performance of A with the antioxidant additive of Scheme 2 (Example 3).
[0013] FIG. 4 shows device performance of A with the antioxidant additive of Scheme 3 (Example 4).
[0014] FIG. 5 shows device performance of A with the radical scavenger additive of Scheme 4 (Example 5).
[0015] FIG. 6 shows device performance of A with the radical scavenger additive of Scheme 5 (Example 6).
[0016] FIG. 7 shows device performance of A with the UV stabilizer of Scheme 6 (Example 7).
[0017] FIG. 8 shows device performance of A with the UV stabilizer of Scheme 7 (Example 8).
[0018] FIG. 9 shows device performance of formulation B with no additives (Example 9).
[0019] FIG. 10 shows device performance of B with the organic-inorganic (silane) additive of Scheme 8 (Example 10).
[0020] FIG. 11 shows device performance of B with the organic-inorganic (silane) additive of Scheme 9 (Example 11).
[0021] FIG. 12 shows device performance of B with the organic-inorganic (silane) additive of Scheme 10 (Example 12).
[0022] FIG. 13 shows device performance of B with the organic-inorganic silane) additive of Scheme 11 (Example 13).
DETAILED DESCRIPTION OF THE INVENTION
[0023] An electroluminescent polymer solution is defined to include a soluble electroluminescent (conjugated) polymer that is mixed at 0.3% to 5% by weight into solution with an appropriate solvent. An example would involve mixing 0.8% of Merck Super Yellow polyphenylene vinylene derivative into an organic solvent, such as m-xylene and chlorobenzene, to form an electroluminescent polymer solution. Examples of electroluminescent conjugated polymers include polyfluorenes, polyphenylene vinylenes, polyphenylene ethynylenes, polyvinyl carbazole, polythiophenes, polyphenylenes, polyanthracenes, and polyspiro compounds. Examples of the solvent include o-xylene, m-xylene, p-xylene, chlorobenzene, dichlorobenzene, toluene, anisole, cyclohexanone, cyclopentanone, cumene, tetrahydrofuran, dioxane, methyl benzoate, methyl anisole, acetonitrile, chloroform, trichlorobenzene, dimethylformamide, dimethylsufoxide, and N-methylpyrrolidone. In addition, the electroluminescent polymer can be added to a mixture of the solvents above.
[0024] A printable electroluminescent polymer ink is defined to include a mixture of the electroluminescent polymer solution that may include other (non-emissive) polymers, multiple ionic surfactants and/or salts, and other organic additives used to decrease material degradation. These organic additives can include moisture getters, antioxidants, photoretarders, radical scavengers, UV stabilizers, and silanes.
[0025] Typical values for the ionic salt are a ratio of 1% to 10% of the ionic salt by weight of the electroluminescent polymer. Typical values for the non-electroluminescent polymer are a molecular weight between 50,000 and 10,000,000 added into the electroluminescent polymer solution in a ratio of 2% to 100% by weight of the electroluminescent polymer, depending on the relative solubility and molecular weights. Examples of preferred salts are given below, as are examples of screen printable electroluminescent polymer inks and resulting device properties. Derivatives of these inks have been demonstrated to produce high performance gravure printable and coatable light emitting polymer (LEP) inks. The present invention also applies to bar coating, gravure printing, spray coating, flexo printing, die coating, slot coating, ink jet printing and other deposition and printing techniques.
[0026] Addition of non-electroluminescent polymers of various molecular weights to the electroluminescent polymer solution may be used to increase the viscosity of the polymer solution or to improve ionic conductivity. Preferred luminescent ink viscosity at 100 rpm at room temperature is in a range of 1 to 300 cPs. Solutions that have too low viscosity can run, or bleed, through printing screens and on the printed substrate, resulting in blurred edges due to ink flow on substrates and print surfaces, loss of patterning, and sticking between the screen and substrate. The viscosity can be increased and controlled to improve printability through the use of polymer additives of various molecular weights. Such a polymer additive should meet several conditions: it should be soluble in a similar solvent as the electroluminescent polymer; it should be electrochemically inert in the chosen medium and operating conditions; it should have an electronic structure so that no significant charge transfer occurs from the electroluminescent polymer to the polymer additive; and it should have a sufficiently large band-gap so that the polymer additive does not significantly absorb the light emission from the electroluminescent polymer. Finally, the polymer additive should have a sufficiently high decomposition temperature that it remains as a solid in the electroluminescent polymer film after the solvent is removed by heating and/or applying a vacuum to the film. Polymers that can be used include ionic conducting materials such as homopolymers or copolymers having units of ethylene oxide, propylene oxide, dimethyl siloxane, oxymethylene, epichlorohydran, phosphazene, bis-(methoxyethoxyethoxy) phosphazene, oxetane, tetrahydrofuran, 1,3-dioxolane, ethylene imine, ethylene succinate, ethylene sulfide, propylene sulfide, oligo(oxyethlene)methacrylate, oligo(oxyethylene) oxymethylene, oligo(oxyethylene) cyclotriphosphaze, and mixtures thereof.
[0027] The ionic conductor in the ink can be selected from different molecular shapes. Examples include linear ionic conducting polymer or oligomer, star-shaped ionic conducting polymer or oligomer, block-ionic conducting polymer or oligomer, random-ionic conducting co-polymer or co-oligomer, dendritic-ionic conducting molecules, comb-ionic conducting polymer or oligomer, cyclic-ionic conducting molecules, or their mixtures. More specific examples are linear polypropylene oxide) (PPO), linear poly(ethylene sulfide), polyphosphazene, polysiloxane, polyethylene imine, star-PEO, star-PEO with silicon core, random copolymer or co-oligomer EO-PO (propylene oxide), random copolymer or co-oligomer EO-dimethylsiloxane, random copolymer or oligomer EO-methylphenyl siloxane, dendritic PEO, dendritic PEO with silicon core, block-EO-PO-EO, block-PO-EO-PO, block-EO-dimethylsiloxane-EO, block-EO-methylphenylsiloxane-EO, comb-PEO, comb-branched polyphosphazene, branched polyethylene imine, alkyl alkoxyl, or aromatic-substituted crown ether, alkyl, or alkoxyl, or aromatic-substituted aza-crown ether, or mixtures of above two or more ionic conducting materials.
[0028] Preferred luminescent conjugated polymers or oligomers or dendrimers contain at least one of the following repeat units: fluorene, spirofluorene, phenylene vinylene, phenylene ethynylene, carbazole, benzocarbazole, thiophene, benzothiophene, etc. Phosphorescent metal complexes can also be doped into LEP ink or chemically attached to luminescent materials.
[0029] In the ink formulation, the ionic salt can be selected from combinations of cation and anion ionic species. Examples of suitable cations are lithium cation, cesium cation, calcium cation, barium cation, rubidium cation, magnesium cation, sodium cation, potassium cation, imidazolium, pyridium, pyrrolidinium, pyrazolium, pyrazole, phosphonium, ammonium, guanidinium, uranium, thiouronium, sulfonium; examples of suitable anions are alkylsulfate, tosylate, methanesulfonate, trifluoromethanesulfonate, bis(trifluoromethylsulfonyl)imide, hexafluorophosphate, tetrafluoroborate, organoborate, thiocyanate, dicyanamide, and halides.
[0030] Multiple salts with different ionic sizes help to achieve a better balance of the ionic doping profile required to maximize charge injection at a device interface or shift the recombination zone away from either interface, and therefore improve lifetime and efficiency. A combination of salts with different mobilities can also be used to achieve faster device turn on while maintaining the longer lifetimes frequently associated with more electrochemically stable and less mobile salts. Less mobile aromatic salts that have better compatibility to LEP and result in better luminescent efficiency can be combined with more mobile non-aromatic salts for faster turn-on. The selection of salts with a specific set of desired properties is described in co-pending U.S. patent application Ser. No. 12/557,316, from which the present application claims priority.
[0031] Preferred organic solvents can dissolve all components of LEP, ionic conductor, and ionic species at room temperature or at an elevated temperature.
[0032] All the organic additives must be soluble in the ink solvents and should not chemically react with the active materials during ink mixing, printing, annealing or device operation. The concentration range is chosen to be between 0.01% to 20% by weight, relative to the weight of the active organic semiconductor materials in the ink. Finally, the additive should be colorless so that it does not absorb the emitted light.
[0033] Preferably, the luminescent ink of the present invention includes at least one luminescent material, at least one ionic salt and/or at least one ion conductor, at least one organic solvent, and at least one additive of organic moisture getter, organic/inorganic hybrid additive, radical scavenger, antioxidant, ultraviolet (UV) stabilizer, photoretarder, or mixtures of these. Examples of the additives include:
1. An organic moisture getter selected from compounds that can be hydrolyzed at temperatures ranging from room temperature (20° C.) to 200° C., for example where the structural component is a substituted oxazolidine unit. See Example 2 below, using BEOXa. 2. An organic/inorganic additive moisture getter selected from compounds that can be hydrolyzed at temperatures ranging from room temperature to 200° C., thereby removing reactive water from the LEP ink. Examples include compounds with structural components of substituted silane (such as alkyl-substituted silanes), or titanium (IV), or zirconium (IV) units. For example, these additives can include alkyl-substituted silanes that will undergo hydrolysis even at room temperature, but are more rapidly activated at higher temperatures. See Examples 10-13 below, using silanes. 3. A radical scavenger selected from compounds that can react with reactive radicals, converting them to less reactive species. For example, the radical scavenger may have a structural component that is an hydroquinone unit. See Examples 5 and 6 below, using MBQ and DMHQ. 4. The antioxidant additive is chosen so it reacts with an oxidant (i.e. a material that can oxidize or attack useful component materials in the LEP ink, in some cases in the presence of optically or electrically-generated excited states) so that it no longer acts as a reactive oxidant. The antioxidant is selected from compounds that can be preferably oxidized by oxygen, ozone, or moisture for example where the structural component consists of a vinyl, substituted phenol or a thioether unit. See Examples 3 and 4 below, using EBP and TDE. 5. A UV stabilizer selected from compounds that can absorb UV light preferably, so that UV light does not induce reactions in the LEP that could lead to photodegradation. For example, the structural component in the UV stabilizer may consist of benzophenones, benzotriazoles, triazines, benzoxazinones, hindered benzoates, or hindered amines. See Examples 7 and 8 below, using BMPP and DTHP. 6. A photoretarder additive is chosen to capture reactive ozone which can also lead to reactions with and degradation of the LEP. A photoretarder is selected from compounds that can react with light preferably, for example where the structural component is a stilbene unit.
[0040] Light emitting devices can be fabricated by printing or spin-casting luminescent ink onto an anode-patterned substrate, followed by printing or vacuum-evaporating a cathode. The device emits electroluminescent or phosphorescent light upon applying voltage or current.
[0041] The present invention removes or reduces the concentration of unwanted impurities and reactive species that are present in an ink formulation, or that are introduced into a printed feature during the deposition process or prior to encapsulation of a device. The unwanted impurities or reactive species can also be formed during device operation or be introduced through ingress of materials from the environment. In one form of the invention, the additives are temporarily inactive, of reduced activity, or latent acting at the time of deposition. The additives may act during or immediately after device fabrication, or they may act after some activation delay. In terms of duration, they may be used to remove initial residual unwanted gases, impurities, or reactive species in the ink or they may be used to remove unwanted species that appear in the ink later in its product cycle, such as by ingress through the encapsulation materials or by outgasing, or by reactions that occur within the ink itself. Materials that remove impurities or reactive species that primarily perform their function after printing using the ink are of particular interest, as these materials remove the unwanted species at a time when those species are no longer intentionally present. Such additives can be present during the fabrication of the device from printing or coating, but are able to perform their actions after the initial fabrication step. In the present invention, additives that originate in the ink are not permanently saturated or consumed by exposure in the process environment, such as while processing in air from solvent-borne solutions. The use of techniques to ensure that the additive materials are at least temporarily inactive, of reduced activity, or latent acting at the time of deposition provides improved function after the electronic device is encapsulated. The additives may then be activated through a variety of known techniques, such as thermal activation (e.g. heating to remove unwanted species to a temperature where they are active), optical activation, electrical activation, removal of a solvent or surfactant that retards activity of the additive, protection of the additive by a matrix that controls diffusion of unwanted species to the additive, or material loss during drying, heating or radiation exposure that activates the additive after the ink is printed or the devices sealed.
EXAMPLES
Standard Light-Emitting Polymer (LEP) Ink Formulation A
Example 1
[0042] In a glove box filled with nitrogen, a polyphenylene vinylene (PPV) polymer Yellow PDY132 (37 mg, Mw 1 million, Merck), polyethyleneoxide (PEO) (6 mg, Mw 600,000, Dow), and salts of tetra-n-hexylammonium hexafluorophosphate (1.70 mg, THAPF 6 ), tetra-n-butylammonium hexafluorophosphate (0.62 mg, TBAPF 6 ), and tribenzyl-n-octylammonium hexafluorophosphate (0.45 mg, BzOAPF 6 ) were mixed together in solvents of chlorobenzene (2.5 g) and m-xylene (2.5 g). After thoroughly mixing, the ink was transferred out from the glove box and screen-printed onto a pre-patterned indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrate with an active area of 1 cm 2 . After removing the solvents by heating the substrate, 600 nm LEP film was obtained on PET substrate. The top electrode Ag from silver paste was subsequently printed onto the luminescent polymer layer, to complete the device fabrication. The device was then transferred into a nitrogen glove box and tested under a constant current density at 4 mA/cm 2 (as was used in Examples 2-13). Both photocurrent and voltage were recorded as function of time ( FIG. 1 ). Here, we have converted the lifetime at maximum brightness to lifetimes at 100 cd/m 2 using an extrapolation t 1/2 ×(Lmax/100) y , where t 1/2 is the time to half maximum luminance, Lmax is the maximum brightness, and y is an exponent generally varying from 1.2 to 2.1. For these PLEC devices based on Merck's Super Yellow LEP, this factor is 1.8. Thus, this device has a brightness lifetime (100 cd/m 2 ) of 800 h when 1.8 power factor is used.
LEP Ink Mixed with Organic Moisture Getter
Example 2
[0043] This ink was formulated in a similar way as described above for Example 1, but adding an additional 6 mg of 3-butyl-2-(1-ethylpentyl)oxazolidine (BEOXa, Scheme 1). BEOxa is very soluble in chlorobene/m-Xylene mixed solvents and is also compatible to LEP polymers. It is believed that BEOXa will be hydrolyzed to open the oxazolidine ring and to form the ketone-alcohol product when heated during both LEP and Ag annealing processes. Removing water in devices definitely improves PLEC lifetime as shown below in FIG. 2 . It has a brightness lifetime (100 cd/m 2 ) of 900 h when 1.8 power factor is used ( FIG. 2 ).
[0000]
LEP Ink Mixed with Antioxidant
Example 3
[0044] This ink was formulated in a similar way as described above for Example 1, by adding additional 6 mg 2,2′-ethylidene-bis(4,6-di-tert-butylphenol) (EBP, Scheme 2). It has a brightness lifetime (100 cd/m 2 ) of 800 h when 1.8 power factor is used ( FIG. 3 ). This antioxidant EBP did not help improve device lifetime, suggesting that its compatibility with LEP was poor and its reactivity with oxidant was ineffective.
[0000]
Example 4
[0045] This ink was formulated in a similar way as described above for Example 1, by adding additional 6 mg 2,2′-Thiodiethanol (TDE, Scheme 3). It has a brightness lifetime (100 cd/m 2 ) of 1050 h when 1.8 power factor is used ( FIG. 4 ). Due to vulnerability of LEP towards oxidants (oxygen, ozone, etc.), TDE acting as a sacrificing agent is blended into LEP film and can easily react with these oxidants, resulting in improved device lifetime.
[0000]
LEP Ink Mixed with Radical Scavenger
Example 5
[0046] This ink was formulated in a similar way as described above for Example 1, by adding additional 6 mg methyl-p-benzoquinone (MBQ, Scheme 4). It has a brightness lifetime (100 cd/m 2 ) of 880 h when 1.8 power factor is used ( FIG. 5 ).
[0000]
Example 6
[0047] This ink was formulated in a similar way as described above for Example 1, by adding additional 6 mg 2,3-dimethylhydroquinone (2,3-DMHQ, Scheme 5). It has a brightness lifetime (100 cd/m 2 ) of 1030 h when 1.8 power factor is used ( FIG. 6 ). It is believed that this 2,3-DMHQ is more efficient to capture reactive radicals to form more stable quinone, as a result, longer device lifetime is achieved.
[0000]
LEP Ink Mixed with UV Stabilizer
Example 7
[0048] This ink was formulated in a similar way as described above for Example 1, by adding additional 6 mg 2-(2H-Benzotriazol-2-yl0-4,6-bis(1-methyl-1-phenylethyl)phenol) (BMPP, Scheme 6). It has a brightness lifetime (100 cd/m 2 ) of 915 h when 1.8 power factor is used ( FIG. 7 ).
[0000]
Example 8
[0049] This ink was formulated in a similar way as described above for Example 1, by adding additional 6 mg 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol (DTHP, Scheme 7). It has a brightness lifetime (100 cd/m 2 ) of 990 h when 1.8 power factor is used ( FIG. 8 ).
[0000]
[0000] Table 1 summarizes device data for Examples 1-8.
[0000]
TABLE 1
Additive
Lmax (cd/m 2 )
t 1/2 (h) for 100 cd/m 2
Standard A
240
800
BEOxa/Moisture getter
225
900
TDE/antioxidant
205
1050
EBP/antioxidant
205
800
MBQ/Radical scavenger
245
880
2,3-DMHQ/radical scavenger
235
1030
BMPP/UV stabilizer
225
915
DTHP/UV stabilizer
225
990
Standard Light-Emitting Polymer (LEP) Ink Formulation B
Example 9
[0050] Standard LEP ink formulation B was made in a similar way as standard LEP formulation A, by replacing Mw 600,000 PEO with Mw 300,000 PEO. It has a brightness lifetime (100 cd/m 2 ) of 1020 h when 1.8 power factor is used ( FIG. 9 ).
LEP ink mixed with organic/inorganic hybrid additives
Example 10
[0051] This ink was formulated in a similar way as described above for Example 10, by adding additional 6 mg triethoxy(octyl)silane (Silane 1, Scheme 8). It has a brightness lifetime (100 cd/m 2 ) of 1300 h when 1.8 power factor is used ( FIG. 10 ).
[0000]
Example 11
[0052] This ink was formulated in a similar way as described above for Example 10, by adding additional 6 mg triethoxyphenylsilane (Silane 2, Scheme 9). It has a brightness lifetime (100 cd/m 2 ) of 1240 h when 1.8 power factor is used ( FIG. 11 ).
[0000]
Example 12
[0053] This ink was formulated in a similar way as described above for Example 10, by adding additional 6 mg tetraethyl orthosilicate (Silane 3, Scheme 10). It has a brightness lifetime (100 cd/m 2 ) of 1450 h when 1.8 power factor is used ( FIG. 12 ).
[0000]
Example 13
[0054] This ink was formulated in a similar way as described above for Example 10, by adding additional 6 mg triethoxyvinylsilane (Silane 4, Scheme 11). It has a brightness lifetime (100 cd/m 2 ) of 1030 h when 1.8 power factor is used ( FIG. 13 ).
[0000]
[0000] Table 2 summarizes device data for Examples 9-13.
[0000]
TABLE 2
Additive
Lmax (cd/m 2 )
t 1/2 (h) for 100 cd/m 2
Standard B
295
1020
Silane 1
320
1300
Silane 2
315
1240
Silane 3
325
1450
Silane 4
300
1030
[0055] While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes in the methods and apparatus disclosed herein may be made without departing from the scope of the invention which is defined in the appended claims. | Organic additives are used to improve the lifetimes of organic electronic devices, such as electroluminescent devices fabricated from polymer luminescent ink. These additives include moisture getters, thermally-activated organic/inorganic hybrids, radical scavengers, antioxidants, UV stabilizers, and photoretarders. For water and oxygen scavengers, activation at elevated temperatures or through another activation method is preferred. This allows for the handling of the device materials containing the scavenger under a lower temperature condition in air where higher levels of ambiently-supplied water or oxygen may also be present. The invention also improves operational lifetimes as getters, scavengers and similar acting additives serve to reduce detrimental reactive species that transport into the device, are generated during operation, or become reactive during operation due to the presence of excited states or external stimulation by electrical, optical or other means. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2009/065374, filed Nov. 18, 2009 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 08021764.9 EP filed Dec. 15, 2008. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a power plant comprising a turbine unit having a turbine, a generator connected to the turbine for power transmission and a cooling device for cooling the generator.
BACKGROUND OF INVENTION
[0003] Various power plant systems are known in which primary energy is converted by means of a generator into electrical energy. In these power plants the heat of a heat generator is generally used to drive a thermal power machine which is connected mechanically to the generator. Both in the conversion of thermal energy into mechanical energy in the primary energy generator, for example a turbine, and also of the mechanical energy into electrical energy in the generator the respective available energy is not completely utilized. Residual energy—usually in the form of heat—is released into the environment.
[0004] In a generator this heat is usually taken away by a cooling medium, e.g. in a closed circuit, in order to prevent overheating of the generator. Since this heat is present at a low temperature level, usually below 100° C., this heat is released unused into the environment and is thus lost to the power plant process.
SUMMARY OF INVENTION
[0005] An object of the invention is to specify a power plant with a higher level of efficiency.
[0006] This object is achieved by a power plant of the type stated above, in which the cooling device is provided in accordance with the invention to release waste heat from the generator to a device of the power plant. The feeding back of waste heat into the power plant process means that it is not removed from the power plant process and is thus not a loss. The efficiency of the power plant can be increased in this way by the proportion of heat fed back into the working process. The turbine can be a gas turbine or a steam turbine.
[0007] Through the use of the generator waste heat in a power plant with a steam turbine for example either the maximum temperature of the steam of the turbine unit embodied as a steam turbine can be increased or the mass flow through the steam turbine can be increased. For a gas and steam turbine block with a total power of 400 to 500 MW the following picture typically emerges: the heat losses created by the generator range between 3 and 5 MW, of which around 2 to 4 MW can be fed back as a power increase into the gas and steam process or into a steam process. With a feed water mass flow of around 80 kg per second and 3 MW fed back generator power loss a temperature increase of around 10° C. is produced in the feed water. With an overall output of 400 to 500 MW this corresponds to a power increase of around 0.5%. With pure steam power processes this allows the quantity of steam which is used for preheating the feed water and which is thus no longer available for generating energy to be reduced.
[0008] In an advantageous form of embodiment of the invention the turbine unit includes a fuel preheater which is thermally connected to the cooling device. The output of waste heat from the generator to the fuel preheater enables the quantity of primary energy which would otherwise have to be supplied to the fuel preheater to be reduced accordingly. The driving force for the feedback is the temperature difference, since the heat can only be transferred to a medium that has a lower temperature than the waste heat of the generator. This usually applies to the fuel of a fossil-fuel power plant, which is at about ambient temperature. Gaseous or fluid fuels in particular can be preheated in a technically simple manner via a heat circuit. Such fuels are especially used in gas turbines. The preheating of the fuel reduces the necessary quantity of fuel for achieving the upper process temperature in the thermodynamic circulation process, whereby its efficiency is increased.
[0009] Advantageously the fuel preheater has a heat exchanger which is thermally connected to a cooling water circuit of the cooling device. For safety reasons fuels may only be combined with a non-oxidizing medium in a heat exchanger in order to avoid combustible mixtures in the event of leakages. The waste heat of the generator is predominantly taken away from the generator via a water circuit. Fuels can be preheated by a heat exchanger in the water circuit without an oxidizing medium coming into contact with the fuel in the event of a leak. If hydrogen is used example for direct cooling of the generator, the outer water circuit can be replaced by the fuel preheater.
[0010] It is also proposed that a fuel feed to the turbine is advantageously routed through the generator for heating of the fuel. The fuel can assume the function of the cooling medium in the generator so that a separate circuit for removing heat from the generator, for example a water circuit, can be dispensed with.
[0011] In a further advantageous embodiment of the invention the turbine unit includes an air feed which is thermally connected to the cooling device. The entry temperature of fresh air which enters into a compressor of a gas turbine is that of the environment. It can thus accept waste heat from the generator. This enables the thermal efficiency of the power plant to be increased.
[0012] In the part load range in a combined cycle gas and steam power plant the overall efficiency is increased for fixed power if the compressor entry temperature is increased. If in this power range the generator waste heat is used for this purpose, a corresponding increase in the thermodynamic efficiency of the power plant is achieved. The feeding of the waste heat to the fresh air can be undertaken by a heat exchanger in the air feed or by the air feed being routed through the generator.
[0013] Advantageously the power plant includes a control means for controlling a heat feed from the generator to a power plant device. The device can be the air feed of the turbine unit for example. In particular the control means is provided for controlling the heat feed as a function of a danger of icing of the air supply. With ambient temperatures close to freezing point and high air humidity air can be heated up before entering the compressor in order to avoid ice formation which can result in damage to components. For this purpose compressed and thereby heated air is fed back to the compressor unit, which adversely affects the efficiency of the compressor. If the waste heat of the generator is used instead, the compressor efficiency remains unaffected and a higher level of efficiency can be advantageously achieved. The control of the control medium can comprise a closed loop process. The probability of icing up can be referred to as danger of icing.
[0014] In a further advantageous form of embodiment of the invention the cooling device has an open cooling circuit and a cooling air feed to an air feed of the turbine unit. In this way the air used for cooling the generator in the open air circuit can be used directly as combustion air for the turbine unit.
[0015] It is also proposed that the turbine unit has an air preheater which in a cooler stage is connected thermally to the cooling device and in a warmer stage to a further heat source of the power plant, for example to a flue gas heat exchanger. In steam power plants the combustion air is typically heated up by an air preheater before entry into the flame chamber of the steam generator. The air preheater is usually supplied with heat from flue gas. However the flue gas may only be cooled down to above dew point since otherwise condensation of water with sulfur compounds results. This would result in greater corrosion. Since the heat from generator and flue gas is present at different temperature levels it can expediently be used sequentially for preheating the combustion air. First of all the combustion air can be preheated by using waste heat of the generator or warm waste air of the generator and in a second step the combustion air can be heated up by heat from the flue gas, in a further heat exchanger for example.
[0016] Advantageously the turbine unit includes a feed water heater, with the cooling device being thermally connected to the feed water heater. In this way waste heat of the generator can be used to preheat the feed water of a steam process or of a gas and steam process. The hot cooling medium in the generator cooling circuit typically reaches the temperature of around 80° C. The preheating is undertaken expediently immediately beyond the feed water pump, where the steam circuit usually reaches the lowest temperature level.
[0017] In principle feed water preheating can be achieved in two ways: In direct incorporation the feed water flows directly through the heat exchanger on the generator. In indirect incorporation a further heat exchanger is used on the feed water side and a separate circuit transfers the heat from the generator to the feed water. For indirect incorporation the cooling device advantageously includes a cooling water circuit which is a part of the feed water circuit of the turbine unit.
[0018] Large power plant systems usually have an extensive complex of buildings which, in addition to the machine halls and the control rooms, also includes office buildings for the administration. In the respective buildings, depending on type and use and taking into consideration the appropriate health and safety at work regulations, appropriate air-conditioning systems must be provided. To this end heating is required in winter while in summer both in the office buildings and also in the machine halls cooling of the ambient air is sensible.
[0019] If the cooling device is connected thermally to a building heating system of the power plant, generator heat occurring in the cooling circuit can be made available for heating the buildings.
[0020] In a further variant the generator waste heat can be used for operating an absorption cooler for buildings air-conditioning. This enables generator waste heat to also be included in the cooling. The overall energy balance of the power plant is increased by relieving the load on the in-house demand network. The load on the feedback cooling circuit of the generator can be relieved in order to contribute in this way to an additional reduction of the power plant's own demands—through the increased net power plant output.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will be explained in greater detail with reference to exemplary embodiments which are shown in the drawings:
[0022] The figures show:
[0023] FIG. 1 a schematic diagram of power plant with a turbine unit and a generator, the waste heat of which is used for preheating a fuel,
[0024] FIG. 2 a schematic diagram similar to FIG. 1 , with the fuel being routed through the generator as a cooling medium,
[0025] FIG. 3 a schematic diagram of a power plant in which generator waste heat is transferred into an air compressor inflow,
[0026] FIG. 4 a schematic diagram of a power plant in which the feed water of a steam turbine is routed through a generator for heating,
[0027] FIG. 5 a feed water circuit for a steam turbine which is thermally connected via a heat exchanger to a coolant circuit of the generator,
[0028] FIG. 6 the feed water circuit in which feed water is routed as a cooling medium via an intermediate cooling circuit of the generator,
[0029] FIG. 7 a schematic diagram of the generator, the waste heat of which is supplied to an air supply before an air preheater for a steam generator, and
[0030] FIG. 8 a diagram similar to FIG. 7 , with an airflow being supplied to an air preheater as a coolant flow through the generator.
DETAILED DESCRIPTION OF INVENTION
[0031] FIG. 1 shows a schematic diagram of a layout of a power plant 2 with a turbine unit 4 which is connected via a shaft 6 to a generator 24 of a generator unit 8 . The turbine unit 4 comprises a turbine 10 which is embodied as a gas turbine and operates an air compressor 12 via the shaft 6 in an air supply 14 to a combustion chamber 16 of the turbine unit 4 . In the combustion chamber 16 fuel from a fuel line 18 is mixed into the compressed air and burned. The hot exhaust gases are supplied to the turbine 10 for its operation. In addition the turbine unit 4 comprises a fuel preheater 20 in the fuel line 18 for preheating the gaseous fuel.
[0032] During the operation of the power plant 2 the turbine 10 drives the air compressor 12 via the shaft 6 and drives the generator 24 via a coupling 22 . During this operation the generator 24 generates heat which is removed from the generator 24 via a cooling circuit 26 . The cooling circuit 26 and a heat exchanger 28 are a component of a cooling device 30 of the generator unit 8 for cooling the generator 24 . The cooling medium of the cooling circuit 26 , for example water, transfers heat in the heat exchanger 28 which it has taken from the generator 24 to a heating circuit 32 through which the heat in its turn is transferred in the fuel preheater 22 the fuel in the fuel line 18 . Through this generator waste heat is used for the purposes of fuel preheating. This causes the necessary quantity of fuel for reaching the upper process temperature in the turbine unit 4 to be reduced and the thermodynamic efficiency of the power plant 2 is increased.
[0033] Instead of the transmission of the waste heat from the generator 24 to the fuel in the fuel line 18 by the fuel preheater 20 , the waste heat from the generator 24 can be used as depicted in the exemplary embodiment shown in FIG. 1 for heating of buildings. A heat exchanger which transfers the waste heat in the heat circuit to a buildings heating circuit would be used for this purpose instead of the fuel preheater 20 . Also conceivable would be the routing of the heating circuit 32 directly through a building and through corresponding heating elements for heating the building for example.
[0034] FIG. 2 shows a schematic diagram of the power plant 2 with an alternate cooling device 36 . The descriptions below are essentially restricted to the differences from the respective preceding exemplary embodiments, to which the reader is referred for features and functions which remain the same. Components which essentially remain the same are basically labeled with the same reference characters and features not mentioned are transferred into the following exemplary embodiments without being described once again.
[0035] By contrast with FIG. 1 , the fuel line 18 is designed with a branch which is routed through the generator 24 . The quantity of fuel to be routed through the generator 24 or a fuel preheater 40 can be adjusted by a valve 38 through a control means 34 . By contrast with the preceding exemplary embodiment the fuel preheater 40 is not thermally supplied with waste heat from the generator 24 but from another heat source. Through the combination of heat transfer to the fuel by the fuel preheater 40 and the cooling device 36 the fuel in the fuel line 18 can also be heated up to a desired temperature independently of the heat occurring in the generator 24 .
[0036] Of course an additional arrangement of the fuel preheater 40 in the fuel line 18 from FIG. 1 is also possible and advantageous. For example it can be arranged in the fuel flow after the fuel preheater 20 as an additional heat source for heating the fuel.
[0037] In the exemplary embodiment shown in FIG. 3 waste heat is transferred from the generator 24 via the cooling circuit 26 and the heat exchanger 28 of the cooling device 30 via a heat exchanger 42 to combustion air in the air feed 14 . Since the overall efficiency of the combined gas and steam power plant can be increased with a fixed output especially in the part load range if the compressor inlet temperature of the combustion air is increased, the combustion air preheating is sensible for increasing the efficiency of the power plant 2 . If the generator waste heat is used to this purpose in this power range in particular, a corresponding increase in the thermodynamic efficiency is achieved.
[0038] A further advantage of the heating of compressor induction air lies in being able to counteract a danger or air filter, compressor diffuser and the first stages of the compressor icing up. Compressor induction air is expediently heated up by this so called anti-icing if it has a temperature around freezing point, i.e. typically between +5° C. and −5° C., and when an air humidity of over 80% exists. The corresponding heating of the compressor induction air is controlled by the control means 34 and by means not shown in the diagram for taking heat from the cooling device 30 .
[0039] The schematic diagram in FIG. 4 shows a power plant 44 with a turbine unit 46 comprising a steam turbine 48 . The steam turbine 46 is supplied with fresh steam which drives the steam turbine 48 via a feed water circuit 50 . Expanded steam is condensed in a condenser 52 and routed by a feed water pump 54 to the generator unit 8 in order to take heat from the cooling device 30 of the generator unit 8 with it for preheating the feed water. In a vessel 56 the feed water preheated with the generator waste heat is brought up to its upper temperature and pressure level and is subsequently routed as fresh steam to the steam turbine 48 .
[0040] To make additional cooling of the generator unit 8 possible the cooling device 30 includes a secondary cooling circuit 58 with a secondary cooler 60 and a cooling water pump 62 . With the aid of the control means 34 and valve 64 additional heat can be extracted by the secondary cooling circuit 58 from the generator 24 , even if no feed water heating is necessary at that moment and the feed water circuit is stationary because the valves 66 are closed.
[0041] The generator 24 is manufactured with a water-called stator and cooling channels made of stainless steel, typically V2A, so that the feed water is routed directly through the stator and can be used for cooling the stator windings.
[0042] Compared to pure steam power processes the quantity of steam which is normally used for preheating the feed water and is thus no longer available for energy generation can be reduced.
[0043] In the exemplary embodiments shown in FIGS. 5 and 6 feed water of the feed water circuit 50 is likewise heated with generator waste heat. In the layout shown in FIG. 5 the feed water is heated up directly in a heat exchanger 72 on the generator 24 . By contrast, in the exemplary embodiment shown in FIG. 6 , an indirect incorporation is realized, in which a further heat exchanger 74 is used on the feed water side and the waste heat from the generator 24 is transferred to the feed water on a separate circuit 76 .
[0044] FIGS. 7 and 8 show sections from a power plant layout similar to FIGS. 1 and 2 , in which the generator waste heat is used by means of a heating circuit 32 ( FIG. 7 ) or directly for heating fresh air for fossil firing of the power plant 2 ( FIG. 8 ). To this end a heat exchanger 42 is arranged in the air feed 14 to a steam generator or vessel of the power plant 2 for example for heating the ambient air with generator waste heat. For additional heating of the combustion air a further heat exchanger 68 is available which is supplied with flue gas heat. In the exemplary embodiment from FIG. 8 the combustion air is routed directly via an air compressor 70 as the cooling medium through the generator 24 and thus directly extracts waste heat from the generator 24 .
[0045] Since the temperature level of the generator 24 and thus of the heating circuit 32 is lower than the temperature level of the flue gas and thus of the heat exchanger 68 , the waste heat from the generator unit 8 is used for first preheating of the combustion air. The subsequent second preheating to a higher temperature level occurs in the heat exchanger 68 . | A power plant including a turbine unit having a turbine, a generator connected to the turbine for power transmission, and a cooling device for cooling the generator is provided. The cooling device is provided to release waste heat from the generator to a device of the power plant. Waste heat may be used in the power plant process, thus attaining increased efficiency. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based on and hereby claims priority to PCT Application No. PCT/DE2003/002943 filed on Sep. 4, 2003 and German Application No. 102 43 142.6 filed on Sep. 17, 2002, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
Radio communication systems are used for the transmission of information, speech or data, with the aid of electromagnetic waves over a radio interface between a sending and a receiving radio station. An example of a radio communication system is the known GSM mobile radio network, as well as its further development GPRS, for which the network architecture is described for example in B. Walke, “Mobilfunknetze und ihre Protokolls” (Mobile Radio Networks and their Protocols), Volume 1, Teubner-Verlag Stuttgart, 1998, Pages 139 to 151 and Pages 295 to 311. In this case a channel formed from a narrowband frequency range and a time slot is provided in each case for transmission of a subscriber signal.
For packet switched data transmission, the data is transmitted for a plurality of subscribers in the time division multiplex over one and the same channel. Each subscriber can thus occupy a plurality of channels simultaneously in this case.
For packet switching, a radio communication system, for example a GSM mobile radio network with GPRS, comprises a plurality of packet data service nodes (Serving GPRS Support Node, SGSN) which are internetworked and establish access to a fixed network. The Serving GPRS Support Nodes are further connected to Base Station Controllers (BSC). Each Base Station Controller in its turn makes possible at least one connection to at least one Base Station (BTS) and handles the administration of the technical resources of the base stations connected to it. Such a base station is a transceiver unit which can establish a telecommunication connection to mobile stations over a radio interface.
The individual subscribers are assigned to a channel via a packet data control unit which is provided in the base station controller in each case.
An area covered by a radio communication system is divided up into individual radio zones which are also referred to as cells. A cell here is served by one of the base stations via which radio connections are set up from mobile stations located in this cell. Further the area which is covered by a radio communication system is subdivided into residence zones, also known as routing areas. A routing area in this case comprises a plurality of radio cells. The area which is controlled by a Serving GPRS Support Node (SGSN) can be assigned a plurality of routing areas. The routing areas are administered by an administration system which is frequently also referred to as Mobility Management and is housed on the packet service node.
If a mobile station moves from the area of a cell into another cell, if the radio connection is still in place, an automatic procedure known as a handover is undertaken. This means that an active radio connection is retained even across cell borders. In the handover procedure the radio connection which is established over a first transceiver unit is switched over to a second transceiver unit.
If a mobile station moves out of the territory of one routing area into another routing area a process known as a routing area update must be undertaken. The mobile station is assigned an identifier in the relevant routing area, known in the GPRS system by the name of Temporary Logical Link Identifier (TLLI). In this case the mobile station must be assigned a new TLLI in the new routing area.
In the GPRS system, Release 5 (see 3GPP TS23.060, Pages 32 to 110) there is provision for the mobile station to establish the necessity for a handover procedure for packet switched data. If a handover procedure is to be performed for a mobile station, the mobile station registers with the base station of the new cell. If a change of routing area is taking place at the same time, a procedure for routing area update must first be performed, in which the mobile station will be assigned a new identifier. Only after the procedure for routing area update has successfully concluded can the exchange of data between the new transceiver unit and the mobile station continue. During the routing area update procedure the exchange of data is interrupted. This interruption is perceived as disruptive for various applications such as streaming applications or conversational services for example.
SUMMARY OF THE INVENTION
There is a need for a method and a suitably adapted radio communication system for executing a handover procedure for a packet switched connection in which the length of time during which the exchange of data is interrupted is reduced.
A packet switched connection is set up between a mobile station and a first transceiver unit. In this case the mobile station is assigned to a first cell, which is served by a first transceiver unit, and a first routing area. If the mobile station now moves into a second cell which is served by a second transceiver unit, and into a second routing area, the connection is assigned a routing area update identifier. Subsequently a handover procedure of the packet switched connection from the first cell into the second cell is performed. After the handover procedure an exchange of data is resumed again over the packet switched connection. After the exchange of data is resumed a procedure for routing area update is performed.
Since the procedure for routing area update is not performed until after the exchange of data has been resumed after the handover procedure, the procedure for routing data update runs in parallel with that for data exchange. This means that the length of an interruption to the data exchange during the handover procedure is greatly reduced. Since the connection is allocated a routing area update identifier which is available in the radio communication system, it is also possible before the procedure for routing area update is performed, to send data to the mobile station which is now in the second cell and the second routing area.
Preferably, before the handover procedure from the first cell into the second cell is executed, radio resources for the packet switched connection are reserved in the second cell. This enables the switchover of the packet switched connection from the first cell to the second cell to be undertaken very quickly, so that in practice an interruption to the exchange of data will be avoided
Preferably data packets for the mobile station which arrive at the first transceiver unit are duplicated as soon as the routing area update identifier is allocated to the connection, that is as soon as it is clear that there is provision for a switchover from the first cell into the second cell and the first routing area into the second routing area. The duplicated data packets are made available in the second transceiver unit, so that the identical data packets are present in both the first transceiver unit and also in the second transceiver unit. The data packets can be duplicated in the first transceiver unit. In this case the duplicated data packets must be transferred via an assigned Serving GPRS Support Node SGSN to the second transceiver unit. Alternatively the data packets can be duplicated in the assigned Serving GPRS Support Node SGSN, from which the data packets are transmitted to the first transceiver unit and to the second transceiver unit. The duplication of the data packets during the time for the handover procedure from the first cell into the second cell ensures that data packets arriving during this period reach the mobile station regardless of via which of the transceiver units the connection is currently switched.
It is possible, that, after the handover procedure, at least for a transitional period, the same data compression and the same data encryption are used as before the handover procedure. The advantage of this is that the handover procedure runs below the layers responsible for data compression and data encryption. These layers, usually LLC (Logical Link Control) and SNDCP (Sub-Network Dependant Convergence Protocol), and the associated protocols can thus continue to be used unchanged. In addition the signaling overhead for a reconfiguration of encryption and compression is avoided.
It is also possible for the mobile station in the first routing area to be assigned a first identifier and in the second routing area a second identifier. The first identifier and the second identifier can be embodied as Temporary Logical Link Identifiers TLLI. For the switchover of the mobile station into the second cell, the mobile station will be assigned a temporary identifier which is used until the procedure for routing area update has been performed. This temporary identifier enables the mobile station to be reached in the second cell, although the procedure for routing area update has not yet been performed. The temporary identifier can be assigned to the mobile station by an administrator, for example the network operator. Alternatively the temporary identifier can be assigned by the associated Serving GPRS Support Node SGSN.
The temporary identifier can be selected from a set of reserved identifiers available for this purpose. These can typically be specific TLLI identifiers, which can for example be designated as handover TLLIs. These identifiers are for example specified by the administrator.
Alternatively the temporary identifier will be made up of a first identifier and of a supplementary identifier, for example a flag. The supplementary identifier is simply appended to the first identifier or prefixes it. The routing area update identifier can for example be used as a supplementary identifier.
Since in the radio communication network it is known from the assigned routing area update identifier that the mobile station with a foreign identifier is located in the second routing area, it is guaranteed that data intended for the mobile station reach the mobile station. A foreign identifier here is taken to mean an identifier which is not assigned to the second routing area, or alternatively an identifier which is assigned to the second routing area but for which an entry has not yet been made in the Mobility Management, as would be the case for a correctly registered subscriber, since the procedure for routing area update has not yet been performed.
At the end of the handover procedure a data packet may be transmitted from the mobile station to the second transceiver unit. Based on the receipt of this data packet the second transceiver unit recognizes that the handover procedure can be completed and starts sending to the mobile station. The data packet which is sent from the mobile station to the second transceiver unit can, if there is no data present to be sent from the mobile station to the transceiver unit, be generated separately for this purpose.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawing of which:
The Figure shows a schematic of the exchange of messages for a cell and routing area update between a mobile station, a base station system and a Serving GPRS Support Node SGSN.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
In a first cell, which is served by a first transceiver unit, a packet switched connection 1 is established from a mobile station MS via a base station system BSS to a Serving GPRS Support Node SGSN. In this case data is transmitted both in the uplink direction from the mobile station MS to the base station system BSS and also in the downlink direction, from the base station system BSS to the mobile station MS. In addition measurement reports 2 , from which the quality of the connection between the mobile station MS and the base station system BSS can be derived, are sent between the mobile station MS and the base station system BSS. On the basis of the measurement reports 2 the necessity for a change from the first cell into a second cell and from a first routing area into a second routing area is recognized in the base station system BSS.
After this a preparation 3 for a handover procedure is started in the base station system BSS. Radio resources are reserved in the second cell for this purpose. This includes the reservation of the transmission capacity on the uplink and downlink channels in the second cell. Furthermore virtual data connections, so-called Network Service Virtual Connections, are reserved for the uplink direction in the second cell. Furthermore the packet switched connection is assigned a routing area update identifier, for example Routing Area Change.
Subsequently a request 4 for a handover procedure is directed to the Serving GPRS Support Node SGSN. The request 4 contains as one of its parameters the routing area update identifier Routing Area Change, identifying the second cell, into which the handover procedure is to lead, as well as information about the properties of the packet data which will be transmitted over the packet switched connection. This type of information is for example so-called Packet Flow Contexts, from which priority and quality of service of the packet data involved are obtained.
In the Serving GPRS Support Node SGSN the packet switched connection is then put into a special mode 5 , which for example is called Handover with delayed Routing Area Update. Simultaneously virtual data connections, for example Network Service Virtual Connections, are reserved in the second cell for the downlink direction. It is also ensured that incoming data packets are duplicated and are forwarded to the first base station and the second base station.
Subsequently the Serving GPRS Support Node SGSN transmits to the base station system BSS an instruction 6 for a handover procedure. The routing area update identifier in the form of the specific state handover procedure with delayed routing area update is sent as an argument. The instruction 6 also includes a temporary identifier HO-TLLI, which is assigned to the mobile station by the Serving GPRS Support Node SGSN. The instruction 6 does not contain any information for reconfiguration of higher layers. In the base station system the instruction 6 is supplemented by parameters of the reserved radio resources, which generates an instruction 7 which is transmitted from the base station system BSS to the mobile station MS.
The mobile station announces itself in a request for communication process 8 with the temporary handover identification HO-TLLI in the second cell and is registered by the base station system BSS. The handover procedure is then ended. The mobile station MS transmits to the base station system BSS a message 9 which signals the end of the handover procedure. This message is called HO-Complete for example. Furthermore the mobile station MS initiates a data transfer 11 to the base station system BSS and transmits to the mobile station MS a data packet in the uplink direction to the base station system and to the Serving GPRS Support Node SGSN. The message 9 HO-Complete can be sent and the data transfer 11 of the data packet undertaken simultaneously or consecutively. In this case it makes no difference whether the message 9 is sent first or the data 11 is transferred first. The message 9 produces an action 10 in the base station system BSS which causes data stored in the base station system BSS for the downlink direction to be sent from the base station system BSS to the mobile station MS. In addition the base station system BSS releases radio resources in the first cell.
The receipt in the Serving GPRS Support Node SGSN of the data packet which was sent in the data transfer 11 brings about an action 12 which causes the duplication of the data packets to be ended. Furthermore the radio resources are released for the first cell. A data transfer 13 in the downlink direction is then undertaken exclusively from the Serving GPRS Support Node SGSN via the second transceiver unit to the mobile station MS.
After the exchange of data 11 , 13 between the mobile station MS and the base station system BSS and the Serving GPRS Support Node SGSN has been resumed again, a procedure 14 for a routing area update is executed in the known way.
In the example described it has been assumed that the first cell and the second cell are served by base stations belonging to one and the same base station system BSS. If this is not the case, the preparation 3 of the handover procedure and the ending 9 of the handover procedure are each undertaken in conjunction with the Serving GPRS Support Node SGSN.
If is also assumed that the data packets are duplicated in the downlink direction in the Serving GPRS Support Node SGSN. A possible alternative is also to duplicate the packets in the base station system BSS. The duplication ensures that data packets to be sent in the downlink direction are kept available during the handover procedure both in the first transceiver unit and also in the second transceiver unit.
The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” or a similar phrase as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004). | A packet-switching connection is set up from a mobile station through a first transceiver unit, whereby the mobile station is assigned to a first cell and a first residence zone. As the mobile station moves to a second cell and a second residence zone, the connection is assigned a residence zone change identification. A transfer procedure for the packet-oriented connection from the first cell to the second cell is carried out. After the transfer procedure a data exchange by the packet-switched connection is reestablished. After reestablishing the data exchange a procedure for residence zone exchange is carried out. | 7 |
CROSS REFERENCE TO A RELATED APPLICATION
This application is based on Provisional Patent application No. 60/456,975, filed Mar. 22, 2003 and entitled “CAPACITANCE MANOMETER HAVING A RELATIVELY THICK FLUSH DIAPHRAGM UNDER TENSION TO PROVIDE LOW HYSTERESIS”.
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention is in the field of pressure transducers having a variable capacitance between a diaphragm exposed to the pressure and a fixed electrode.
2. Description of the Related Art
Capacitance diaphragm gauges (CDGs) have been used for many years to measure pressures. CDGs are particularly useful for measuring very low pressures (e.g., much lower than atmospheric pressure) such as pressures in an evacuated system (e.g., a semiconductor fabrication system). A CDG produces an electrical output that represents a measure of a pressure input with respect to a reference pressure.
Basically, an exemplary CDG includes at least one electrode that is supported on a suitable support structure. The electrode is positioned in close proximity to a flexible diaphragm in a sealed and evacuated cavity. The diaphragm is positioned in the device so that one face of the diaphragm (the pressure face) is exposed to an unknown pressure to be measured. The electrode is proximate to the opposite face of the diaphragm (the electrode face). The unknown pressure on the pressure face is measured relative to a reference pressure on the electrode face. The reference pressure is substantially constant within the sealed and evacuated cavity. The diaphragm and the electrode comprise the two plates of a variable capacitor that has a capacitance the varies in response to deflections of the diaphragm caused by pressure variations.
In many applications, the CDG is positioned within a suitable housing of a pressure-measuring device with the pressure face of the diaphragm exposed to the unknown pressure via suitable passages. Alternatively, the pressure face of the diaphragm may be exposed directly to the unknown pressure. For example, the CDG may be mounted such that the pressure face of the diaphragm is in a gas flow conduit, in which case it is preferable that the diaphragm and other portions of the CDG do not extend into the gas flow to partially block the gas flow or to cause turbulence in the gas flow. If no portion of the CDG extends beyond the pressure face of the diaphragm, the pressure face can be mounted substantially flush with an inner wall of the gas flow conduit. A CDG having such a configuration is called a flush diaphragm design. One skilled in the art will appreciate that a flush diaphragm CDG can be welded into a housing to make a more general device. On the other hand, a CDG that does not have flush diaphragm generally is not convertible to be used in applications requiring a flush diaphragm device because the outer support structures for the diaphragm extend beyond the pressure face of the diaphragm.
CDGs having flush diaphragms are known in the art. For example, a first type of flush diaphragm CDG is machined out of a solid block of suitable material to leave a thin layer of material at one end of the block to form the diaphragm. In some cases, the material may be heat treated for certain desired results or because of the properties of the material.
Another known type of flush diaphragm CDG is called corrugated diaphragm CDG. The corrugated diaphragm has waves formed into the surface to cause extra material to be present in order to produce more linear deflections in response to the applied pressure. The diaphragm for this type is usually welded into place.
A third type of flush diaphragm CDG has a diaphragm formed from a thin material. The thin material is highly tensioned in some manner and is welded in place.
Much emphasis is placed on the hysteresis characteristics of a finished pressure measuring device. Hysteresis refers to the differences between the output of the transducer on approaching a given pressure from different directions (i.e., approaching the given pressure from higher pressures as the unknown pressure is decreasing versus approaching the given pressure from lower pressures as the unknown pressure is increasing). Although the same output value should be generated for the given pressure irrespective of the previous pressure, hysteresis effects may cause the output value to be too high when the given pressure is approached from a higher pressure and may cause the output value to be to low when the given pressure is approached from a lower pressure.
The maximum value of the hysteresis error is usually at the midpoint of the pressure excursions. An excursion from zero pressure to full-scale pressure is the maximum normal excursion. Abnormal excursions can cause greater errors. Since hysteresis errors depend at least in part on the magnitude of the pressure excursions, the hysteresis errors are usually unpredictable and are therefore major concerns. In contrast, other errors, such as, for example, linearity or temperature errors, are more correctable because they are repeatable and therefore predictable.
A diaphragm subjected to pressure has to carry the pressure load. The difference between the pressures applied on the opposite faces of the diaphragm causes a deflection of the diaphragm. The electrode face of diaphragm acts as one plate of a variable capacitor having the electrode as the other plate of the capacitor. If additional electrodes are included, multiple capacitors are formed with the electrode face of the diaphragm forming one plate of each capacitor. The deflection of diaphragm moves the diaphragm closer to or farther from the electrode, thus varying the capacitance. The capacitance is determined in a suitable conventional manner to provide a measurable quantity responsive to the pressure applied to the pressure face of the diaphragm.
In order to produce repeatable measurements of the unknown pressure, the diaphragm deflection should occur with a minimum of hysteresis. That is, when the pressure returns to the previous magnitude, the diaphragm should return to its previous state of deflection regardless of whether the pressure initially increased and then decreased or initially decreased and then increased.
Reduction of hysteresis has been accomplished by carrying the load in tension. It has been found that smaller changes in the magnitude of the tension in response to pressure changes results in less hysteresis and thus results in greater measurement accuracy. One problem with high pressure measuring devices is to keep the deflection small enough by having a pretension carrying the load.
Many techniques have been used to pretension diaphragms, particularly for diaphragms in low pressure CDGS; however, the techniques used for high pressure diaphragms have proven to be very limited, and as the devices have become smaller, the techniques have become even more limited. One technique that has been used to pretension a diaphragm is to heat the diaphragm prior to welding the diaphragm to the body of the CDG so that when the diaphragm cools, the diaphragm will shrink and develop tension. Previous attempts to do pretension a diaphragm with this technique consisted of placing the diaphragm in contact with a heated platen. This technique causes the whole fixture to become hot and thus causes a significant uncertainty in results as sequential units are processed. Such a technique also presents problems in maintaining good thermal contact between the diaphragm and the platen, which again causes the resulting tension on the diaphragm to be nonrepeatable.
The support structure in a typical CDG is formed as one piece with a portion of the structure proximate to the diaphragm providing the function of a shim that spaces the diaphragm away from the electrode in its rest or zero position. Forming the shim as part of the CDG body is a very expensive and unrepeatable way to obtain the spacing between the diaphragm and the electrode. For example, the thin lip of the shim needs to be machined in with great care to provide the tolerances that are necessary to produce a repeatable initial zero capacitance. The shim is under great pressure when the diaphragm deflects. Therefore, the shim needs to be extremely hard. In order to obtain the required hardness with the one-piece design, the part is heat-treated after machining. The heat-treating may cause the part to warp and to lose the spacing accuracy that is required for precision measurements.
SUMMARY OF INVENTION
Embodiments in accordance with the present invention provide a capacitance diaphragm gauge (CDG) having a flush diaphragm with low hysteresis characteristics. The CDG has a simple structure that can be repeatably manufactured in an affordable manner.
One aspect of embodiments in accordance with the present invention is a capacitance diaphragm gauge (CDG) having a flush diaphragm mounted on the body of the CDG by a technique that produces a very high pretension on the diaphragm with a magnitude approximately half the magnitude of the ultimate strength of the diaphragm material. Such a pretension can be shown to be the optimum operating point that minimizes the bending stress of the diaphragm relative to the allowable stress. Since the bending stress on the diaphragm is a primary cause of hysteresis, the hysteresis is minimized by this technique.
In particular, in embodiments described herein, heat is applied to the diaphragm prior to welding the diaphragm to the CDG body. After the welding is completed, the diaphragm is pretensioned as the diaphragm shrinks while cooling.
In a preferred embodiment, the diaphragm is illuminated with high intensity radiation. For example, the radiation may be provided by a laser or other suitable source. In one particular embodiment, the radiation is generated by a halogen lamp suitably positioned to irradiate a face of the diaphragm. The radiation source is turned on for a few seconds before beginning the welding process and remains on during the welding process. The radiation is caused to selectively heat the diaphragm by raising the emissivity of the diaphragm relative to its surroundings to increase the absorption of the radiation. By increasing the temperature of the diaphragm relative to the surrounding material of the CDG body, the diaphragm expands relative to the surrounding material prior to the welding process. The diaphragm is welded while it is expanded to cause the diaphragm to become pretensioned when it is cooled after the welding is completed.
The radiation intensity from the laser, the halogen lamp or other radiation source can be controlled adequately to provide a repeatable temperature so that the pretensioning produces repeatable stress of approximately one half the ultimate stress.
An ordinary metal has a very low emissivity and thus has very low absorption. Substantially all of the incident radiation is reflected, and the small amount retained will increase the temperature an inadequate amount. Furthermore, the temperature increase is not likely to produce repeatable results. In accordance with the particularly preferred embodiment, the emissivity of the surface of the diaphragm is increased by coating the surface with carbon or another suitable substance. Preferably, the surface of the diaphragm is coated in a manner that permits the diaphragm to be cleaned easily after the welding process is completed. For example, carbon black (e.g., soot) has been found to be suitable to increase the emissivity and to be easily removed after the processing is completed. In one particular embodiment, the carbon black is applied by exposing the pressure surface of the diaphragm to an oxidizing flame of butane (e.g., from a lighter or the like). The oxidizing flame deposits a thin layer of carbon on the pressure surface. The thin carbon layer absorbs radiation to cause the diaphragm to heat rapidly while the other components remain relatively cool. The carbon layer washes off easily without requiring abrasive cleaning.
The techniques described herein are used to produce CDGs having separate, thin unmachined diaphragms. The diaphragms are easily heat treated to the optimum properties in contrast to the very expensive process of machining the diaphragm and support out of one piece and then trying to heat treat the diaphragm after machining without warping the diaphragm. The process described herein allows a diaphragm to be installed on the support in a cost efficient and optimum manner and provides outstanding performance with respect to the deflection characteristics of the diaphragm. In particular, the diaphragm has a low hysteresis.
Unlike prior devices with a one-piece body structure having the shim formed as a part of the body structure, embodiments in accordance with the present invention include a separate shim that can be heat treated separately. Like the diaphragm, the shim does not need to be machined. Therefore, the shim does not warp or change its thickness in any way. Thus, optimum performance is obtainable with low-cost parts that are easy to manufacture with repeatable characteristics. As a result, the support structure (e.g., the body of the CDG) in accordance with the embodiments described herein is a simple mass producible part.
In order to weld the diaphragm while heated, the diaphragm and the shim are fixed between an upper pressure nose and a lower support surface of a hydraulic arbor press while the heated diaphragm and the shim are welded to the CDG body. In non-flush diaphragm configurations, an outer support ring is also welded during the same process and remains as part of the CDG. In order to obtain a flush diaphragm in accordance with the embodiments described herein, the diaphragm rests on a reusable support jig during the welding process. The support jig is positioned on the lower support surface of the arbor press, and the upper pressure nose is forced against the rear surface of the CDG body. Pressure from the arbor press secures the diaphragm to the CDG body during the welding process. The support jig comprises a high temperature (e.g., refractory) material that does not melt during the welding process and thus does not become attached to the diaphragm. Exemplary refractory materials, such as, for example, tantalum and silicon carbide, are suitable for the support jig.
Alternative embodiments in accordance with the present invention include a two-piece electrode that provides a stable capacitance under variations of temperature in contrast to known single-piece electrode designs in the past. The expansion of an electrode in response to temperature increases the rest capacitance. The increase in rest capacitance may be cancelled by increasing the space between diaphragm and the electrode. The increased space can be provided by making the net expansion of the single electrode smaller than the support path through the shim. This is accomplished in preferred embodiments using a two-piece electrode. A two-piece electrode suitable for high pressure measurements comprises an outer portion comprising titanium or titanium alloy. The titanium or titanium alloy material has high strength bonding characteristics that withstand the great forces of overpressure that are unique to a high pressure CDG. The inner portion of the two-piece electrode is joined to the outer portion by welding (or by another suitable manner that joins the pieces as if they were welded). For example, 300 series stainless steels have been found to be suitable for use as the inner portion. In an embodiment described herein, the inner portion advantageously comprises nickel. Alternatively, suitable performance can be achieved by a single-piece electrode comprising titanium or a titanium alloy.
Further embodiments in accordance with the present invention include a second electrode positioned proximate to the perimeter of the diaphragm to compensate for the expansion of the space between the electrode and the diaphragm by providing a second capacitance measurement signal that can be processed to cancel out the effect of the expansion.
BRIEF DESCRIPTION OF DRAWINGS
The foregoing and other features of embodiments of the present invention are described below in connection with the accompanying drawing figures in which:
FIG. 1A illustrates a front perspective view of an embodiment of a capacitance diaphragm gauge (CDG) in accordance with the present invention, showing the pressure face of a flush diaphragm;
FIG. 1B illustrates a rear perspective view of the CDG of FIG. 1A showing the shielded electrode connection, the threaded hole for making electrical connection to the body of the CDG and the pinched-off evacuation tube;
FIG. 2A illustrates a cross section of the CDG of FIG. 1A taken along the lines 2 A— 2 A in FIG. 1A ;
FIG. 2B illustrates an enlarged cross section of the CDG taken along the lines 2 B— 2 B of FIG. 2A to show the shim between the diaphragm and the CDG body in more detail;
FIG. 3 illustrates an exploded rear perspective view of the CDG of FIGS. 1A and 1B showing the electrode, the electrode shield, the insulating glass preforms and the evacuation tube;
FIG. 4 illustrates an exploded front view of the CDG of FIGS. 1A and 1B showing the relationship between the diaphragm, the shim and the electrode;
FIG. 5 illustrates a pictorial depiction in partial cross section of the CDG body, the shim and the diaphragm positioned on a reusable supporting ring in a hydraulic arbor press, which applies pressure while a radiation source applies radiation to heat the diaphragm during a welding process; and
FIG. 6 illustrates a cross section of an alternative embodiment in accordance with the present invention in which two electrodes are provided in order to compensate for changes in the spacing between the diaphragm and the center electrode with temperature.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A , 1 B, 2 A, 2 B, 3 and 4 illustrate an embodiment of a capacitance diaphragm gauge (CDG) 100 . As shown in FIG. 1A , the CDG 100 includes a body structure 110 , having a front surface 112 (see FIG. 4 ) and a rear surface 114 (see FIG. 4 ). In the embodiments illustrated herein, body structure 110 is generally cylindrical, and the front surface 112 and the rear surface 114 have circular shapes. In the preferred embodiments, the area of the front surface 112 is smaller than the area of the rear surface 114 , and a forward cylindrical portion 116 of the body structure 110 proximate to the front surface 112 has a smaller diameter than a rearward cylindrical portion 118 proximate to the rear surface 114 such that the body structure 110 has a stepped transition from the front portion 116 to the rear portion 118 that forms a lip 119 around the front portion 116 . The lip 119 may be used when mounting the CDG 100 in certain applications.
A flush diaphragm 120 is mounted proximate to the front surface 112 of the body structure 110 and is spaced apart from the front surface 112 by a circular shim 122 (shown more clearly in FIGS. 2A , 2 B and 4 ). The diaphragm 120 has a diameter of approximately 1 inch (2.54 cm) and has a thickness that can range from 0.001 inch (0.025 to 0.015 inch (0.38 mm). Preferably, the diaphragm 120 comprises Inconel 750 or another suitable material.
The circular shim 122 comprises Inconel 750 formed as a thin ring having an outer diameter of approximately 1 inch (2.54 cm) and an inner diameter of approximately 0.98 inch (2.49 cm). In a preferred embodiment, the shim 122 has a thickness of approximately 0.003 inch (0.08 mm). Thus, the diaphragm 120 is spaced from the front surface 112 by approximately 0.003 inch. In the preferred embodiment, the shim 122 is a separate unit as illustrated in the figures. The shim 122 forms a raised perimeter portion that bounds the flat front surface 112 of the body structure 110 . In alternative embodiments, the shim 122 can be formed as part of the body structure 110 by machining or other suitable technique to form a raised perimeter portion around a substantially flat central portion of the front surface 112 . The raised perimeter portion has an effective thickness measured perpendicular to the central portion of the front surface 112 that corresponds to the thickness of the shim 122 , as discussed above.
As shown more clearly in FIGS. 2A and 4 , a cylindrical bore 124 extends through the body structure 110 from the front surface 112 to the rear surface 114 and is generally centered with respect to both surfaces. An electrode assembly 130 extends through the cylindrical bore 124 . The electrode assembly 130 comprises a cylindrical electrode 132 surrounded by a concentric electrode shield 134 . The electrode assembly 130 is positioned through the cylindrical bore 124 so that a front surface 136 of the electrode 132 and a front surface 138 of the electrode shield 134 are substantially flush with the front surface 112 of the body structure 110 , as shown in FIGS. 2A and 4 .
As shown in FIG. 2A , the electrode 132 is electrically insulated from the electrode shield 134 by a first concentric insulator 140 positioned between the electrode 132 and the electrode shield 134 . Similarly, the electrode shield 134 is electrically insulated from the wall of the bore 124 and is thus insulated from the body structure 110 by a second concentric insulator 142 positioned between the electrode shield 134 and the wall of the cylindrical bore 124 .
As illustrated in FIG. 3 , the first concentric insulator 140 is advantageously formed by placing a first plurality of ring-shaped glass preforms 140 a , 140 b around a portion of the electrode 132 , positioning the electrode shield 134 over the first plurality of glass preforms 140 a , 140 b . The second concentric insulator 142 is advantageously formed by placing a second plurality of glass preforms 142 a , 142 b , 142 c , 142 d around the electrode shield 134 and then positioning the electrode shield 134 within the cylindrical bore 124 . The glass preforms 140 a , 140 b are sized to generally center the electrode 132 within the electrode shield 134 , and the glass preforms 142 a , 142 b , 142 c , 142 d are generally sized to center the electrode shield 134 within the cylindrical bore 124 .
The components are positioned as described in an alignment fixture (not shown). The front surface 136 of the electrode 132 advantageously includes a small opening 144 that is engageable with a pin (not shown) in the alignment fixture. Similarly, a hole (not shown) in the alignment fixture is engageable with a contact pin 146 extending from a rear surface 148 of the electrode 132 . The opening 144 and the pin 146 maintain the electrode 132 in a substantially concentric position within the electrode shield 134 until the glass preforms 140 a , 140 b , 142 a , 142 b , 142 c , 142 d have been heated sufficiently to flow around the electrode 132 and the electrode shield 134 and have subsequently cooled. In certain preferred embodiments, the glass preforms, 140 a , 140 b , 142 a , 142 b , 142 c , 142 d advantageously comprise borosilicate glass that softens sufficiently at approximately 700° C. to flow around the components and form a permanent insulating bond.
After the body structure 110 has cooled, the front surface 112 of the body structure 110 is smoothed by lapping or other suitable method so that the front surface 136 of the electrode 132 is flush with the front surface 112 .
In the preferred embodiment, the electrode 132 comprises a front portion 132 a and a rear portion 132 b . The rear portion 132 b advantageously comprises titanium, which has a low coefficient of expansion in response to temperature. Thus, as the temperature is increased to cause the glass preforms to flow and subsequently decreased to form the permanent bond, the diameter of the rear portion 132 b remains sufficiently constant that the glass bond formed around the rear portion 132 b remains intact as the glass hardens.
In the preferred embodiment, the diaphragm 120 , the shim 122 and the body structure 110 comprise Inconel 750 or other suitable material. The front portion 132 a of the electrode 132 advantageously comprises nickel. The front portion 132 a has a similar coefficient of expansion in response to temperature as the body structure 110 , the diaphragm 120 and the shim 122 . Thus, the front portion 132 a expands and contracts substantially in proportion to the other components to thereby maintain a relatively fixed spacing with respect to the diaphragm 120 . The electrode shield 134 also advantageously comprises nickel in order to have a similar coefficient of expansion.
FIG. 5 illustrates a system for mounting the diaphragm 120 and the shim 122 to the body member 110 . After the electrode 132 and electrode shield 134 are bonded to the each other and to the body structure 110 , as described above, the shim 122 and the diaphragm 120 are welded to the front surface 112 of the body structure in a manner that pretensions the diaphragm 120 . In particular, the shim 122 is positioned on the front surface 112 such that the outer perimeter of the shim 122 substantially conforms to the outer perimeter of the front surface 112 . The circular diaphragm 120 is then positioned on the shim 122 . A reusable, ring-shaped tooling jig (support jig) 170 is then positioned over the diaphragm 120 .
The body structure 110 , the shim 122 , the diaphragm 120 and the tooling jig 170 are positioned in a hydraulic arbor press 172 , a portion of which is shown in FIG. 5 in partial cross section. The tooling jig 170 rests on a cylindrical lower support surface 174 of the arbor press 170 with the diaphragm 120 , the shim 122 and the body structure 110 resting on the tooling jig 170 . A cylindrical upper pressure nose 176 of the arbor press 172 is positioned on the rear surface 114 of the body structure 110 . A varying force is applied to the pressure nose 176 of the arbor 172 by hydraulic cylinders (not shown) or other conventional equipment to thereby squeeze the diaphragm 120 and the shim 122 between the perimeter of the front surface 112 and the tooling jig 170 .
As further shown in FIG. 5 , a source 180 of radiant energy is positioned below the diaphragm 120 . For example, a halogen lamp 180 advantageously provides the radiant energy in the illustrated embodiment. The radiant energy is directed toward the diaphragm 120 to heat the diaphragm and cause the diaphragm to expand.
Since the diaphragm 120 comprises Inconel, which has a generally high reflectivity, a substantial portion of the radiant energy incident on the diaphragm 120 from the lamp 180 would ordinarily be reflected. In order to enhance the absorption of the radiant energy, the diaphragm is coated with a high emissivity material since a high emissivity material also readily absorbs radiant energy. On the other hand, many high emissivity coatings are difficult to remove from a surface. Any contaminating material remaining on the exposed surface of the diaphragm 120 would likely affect the performance of the diaphragm. In preferred embodiments, the exposed surface of the diaphragm 120 is coated with lamp black (e.g., soot) 182 . For example, in one embodiment, the lamp black 182 is formed on the diaphragm 120 by positioning a butane flame (not shown) proximate the exposed surface. After permanently fixing the shim 122 and the diaphragm 120 to the body structure 110 , as described below, the lamp black 182 is easily removed from the diaphragm with water or a mild cleaning solution without using abrasives or force that might damage the diaphragm 120 .
Initially, a sufficient pressure is applied to the rear surface 114 of the body structure 110 to maintain the relative positions of the body structure 110 , the shim 122 and the diaphragm 120 while the diaphragm 120 is heated by the radiant energy absorbed by the lamp black 182 , thus causing the diaphragm 120 to expand. Full pressure is then applied to the assembled components to restrain the diaphragm 120 in the expanded configuration.
A welding head 190 is activated to fuse the diaphragm 120 and the shim 122 to the front surface 112 of the body structure 110 . The welding head 190 revolves about the perimeter of the diaphragm in a conventional manner (e.g., electrical arc welding, laser welding, electron beam welding, or other suitable bonding processes) to form a continuous weld around the entire perimeter of the diaphragm 120 . The diaphragm 120 and the shim 122 are secured to the body structure 110 to thereby form a sealed cavity between the inner surface of the diaphragm and the front surface 112 of the body structure.
The tooling jig 170 comprises a refractory metal or other suitable material (e.g., tantalum or silicon carbide) having a much higher melting temperature than the Inconel 750 material used for the body structure 110 , the shim 122 and the diaphragm 120 . Thus, the tooling jig 170 is not affected by the welding process and does not fuse with the other components. The welded components are readily removable from the tooling jig 170 , and the same tooling jig 170 can be used multiple times.
When the lamp 180 is turned off, the diaphragm 120 gradually cools and contracts. However, since the outer perimeter of the diaphragm 120 is firmly secured to the body structure 110 , which was not heated to any significant extent by the radiant energy, the surface of the diaphragm 120 effectively stretches and becomes pretensioned as it cools.
Because of the pretensioning introduced by the foregoing assembly method, the diaphragm 120 has very little hysteresis. When used in a pressure-sensing application, the pretensioning of the diaphragm 120 causes the diaphragm to return to its initial undeflected position after being deflected by pressure variations.
As further illustrated in FIGS. 1B and 3 , a smaller through bore 150 extends from the front surface 112 to the rear surface 114 . During assembly of the CDG 100 , an evacuation tube 152 is mounted into the bore 150 . After the CDG 100 is fully assembled, a very low pressure is applied to the evacuation tube 152 to remove any residual gases within a cavity formed between the front surface 112 and the diaphragm 120 . The evacuation tube 152 is then pinched to form a cold weld and the excess portion of the evacuation tube 152 is removed to form a stub as shown in FIG. 1 B.
The rear surface 114 further includes a threaded bore 160 that extends a selected depth into the body structure 110 but does not extend to the front surface 112 . When the CDG 100 is installed in a pressure sensing application, an electrical connection (not shown) is attachable to the body structure 110 by engaging the threaded bore 160 with a screw (not shown) to thereby complete an electrical circuit to the diaphragm 120 via the body structure 110 and the shim 114 . Thus, a first electrical connection is made to one plate of the variable capacitor formed by the diaphragm 120 and the front surface 136 of the electrode 132 . A second electrical connection is made to the electrode 132 by engaging the pin 146 with the center contact of a coaxial connector (not shown). The shield contact of the coaxial connector engages the electrode shield 134 .
Note that the cross section in FIG. 2A is selected so that the through bore 150 , the evacuation tube 152 and the threaded bore 160 are not shown.
In some embodiments, an additional through bore (not shown) may be included to allow installation of a conventional getter can (not shown) to chemically remove any residual gas remaining after the evacuation process.
The structure of the CDG 100 and the method of pretensioning the diaphragm 120 permits CDGs to be manufactured with a wider range of pressure-sensing capabilities. For example, a diaphragm 120 having a diameter of approximately 1 inch (2.54 cm) and having a thickness of approximately 0.001 inch (0.025 mm) can be manufactured to measure pressures in a range extending from 0.0001 Torr to 1 Torr up to a range extending from 0.001 Torr to 10 Torr. A diaphragm 120 having a similar thickness and a diameter of approximately 2 inches (5.08 can be manufactured to measure pressures in a range extending from 0.00001 Torr to 0.1 up to a range extending from 0.001 Torr to 10 Torr.
The structure of the CDG 100 and the method of pretensioning the diaphragm 120 is particularly advantageous for manufacturing CDGs for measuring higher ranges of pressures using much diaphragms that are proportionately thicker with respect to their diameters.
Heretofore, CDGs having pretensioned flush diaphragms with very low hysteresis and having sufficient thicknesses to measure higher pressure ranges were not available at reasonable costs. The structure and method of the embodiments described herein provide low cost, very accurate flush diaphragms that can be manufactured for use in a variety of applications. For example, a diaphragm 120 having a diameter of approximately 0.75 inch (1.9 cm) and a thickness of 0.001 inch (0.025 mm) can be manufactured to measure pressures in a range extending from 0.01 Torr to 100 Torr. A diaphragm 120 having a diameter of approximately 0.75 inch (1.9 cm) and a thickness of 0.003 inch (0.076 mm) can be manufactured to measure pressures in a range extending from 0.1 Torr to 1,000 Torr. A diaphragm 120 having a diameter of approximately 0.75 inch (1.9 cm) and a thickness of 0.01 inch (0.254 mm) can be manufactured to measure pressures in a range extending from 1 Torr to 10,000 Torr.
FIG. 6 illustrates a cross section of an alternative embodiment of a CDG 200 in accordance with the present invention in which two electrodes are provided in order to compensate for changes in the spacing between the diaphragm and the center electrode responsive to temperature variations. The embodiment of FIG. 6 is particularly advantageous for improving the performance of CDGs having larger diameter diaphragms (e.g., diameters on the order of 2 inches). The structure of the CDG 200 is similar to the structure of the CDG 100 described above, and like elements not specifically discussed below are not numbered in FIG. 6 .
The CDG 200 includes a body structure 210 comprising Inconel 750 . The body structure 210 is generally circular as was illustrated above for the body structure 110 of the CDG 100 . The body structure 210 has a diameter of approximately 2 inches (5.08 cm). The body structure 210 has a front surface 212 and a rear surface 214 .
A diaphragm 220 is positioned proximate to the front surface 212 and is spaced from the front surface 212 by a circular shim 222 . The diaphragm 220 and the shim 222 are constructed as described above; however, the diameters are larger (e.g., 2 inches (5.08 cm) to correspond to the diameter of the body structure 210 .
A first bore 224 a extends through the body structure 210 from the center of the front surface 212 to the center of the rear surface 214 . A second bore 224 b extends through the body structure 210 in parallel to the first bore 224 a . The second bore 224 b is located near the perimeter of the front surface 212 .
A first electrode assembly 230 a is positioned within the first bore 224 a , and a second electrode assembly 230 b is positioned within the second bore 224 b . Each of the electrode assemblies 230 a , 230 b is advantageously constructed in the manner described above with respect to the electrode assembly 130 . In particular, the first electrode assembly 230 a includes a first electrode 232 a that has a first electrode front surface 236 a , and the second electrode assembly 230 b includes a second electrode 232 b that has a second electrode front surface 236 b.
The body structure 210 advantageously includes a through bore to accommodate a evacuation tube and a threaded bore to receive an electrical connection. These elements are not shown in FIG. 6 ; however, the elements correspond to like elements shown in FIG. 3 .
The CDG 200 is assembled as described above in connection with the CDG 100 so that the diaphragm 220 is pretensioned across the front surface 212 of the body structure 210 , and the cavity between the inner surface of the diaphragm 220 and the front surface 212 is evacuated and sealed.
The inclusion of the second electrode assembly 230 b in the CDG 200 is particularly advantageous when a larger diameter diaphragm is used. As the temperature increases around the CDG 200 , the shim 222 will tend to expand to cause the diaphragm 220 to move away from the front surface 212 proximate to the front surface 236 a of the first electrode 232 a . Thus, the capacitance between the first electrode 232 a and the diaphragm 220 will change with temperature. Since the change in capacitance caused by temperature may not be readily distinguished from the change in capacitance caused by pressure, the measured capacitance may not accurately indicate the pressure.
Since the second electrode assembly 230 b is located near the perimeter of the diaphragm 220 where the diaphragm 220 is secured to the front surface 212 via the shim 222 , the spacing between the portion of the diaphragm 220 and the front surface 236 b of the second electrode 232 b changes very little in response to pressure changes. However, the spacing between the diaphragm 220 and the front surface 236 b of the second electrode 232 b changes substantially the same as the spacing between the diaphragm 220 and the front surface 236 a of the first electrode 232 a in response to temperature changes. Thus, the change in capacitance caused by the change in temperature is substantially the same for both electrodes. Therefore, the capacitance measurement taken between the diaphragm 220 and the first electrode 232 a and the capacitance measurement taken between the diaphragm 220 and the second electrode 232 b are used to compensate for the effect of temperature when the pressure is determined.
This invention may be embodied in other specific forms without departing from the essential characteristics as described herein. The embodiments described above are to be considered in all respects as illustrative only and not restrictive in any manner. The scope of the invention is indicated by the following claims rather than by the foregoing description. Any and all changes which come within the meaning and range of equivalency of the claims are to be considered within their scope. | A capacitance diaphragm gauge (CDG) for measuring pressure includes a flush diaphragm mounted to a body structure via a shim or other raised perimeter portion. The diaphragm and the shim are welded to the body structure while the diaphragm is maintained at an elevated temperature. Contraction of the diaphragm as it cools pretensions the diaphragm to substantially reduce hysteresis effects. An electrode advantageously includes two portions with one portion providing excellent bonding characteristics and the other portion having temperature characteristics corresponding to the body structure and the diaphragm. An alternative CDG includes two identical electrodes with a first electrode positioned proximate to the center of the diaphragm and with a second electrode positioned proximate to the perimeter of the diaphragm. The second electrode provides a second capacitance signal that is used to compensate for changes in capacitance between the diaphragm and the first electrode caused by temperature changes. | 6 |
TECHNICAL FIELD
The present invention relates in general to automotive shade roller assemblies, and more particularly to closures for shade rollers in combination with a security light.
BACKGROUND OF THE INVENTION
Shade rollers are well known in the art, and a wide variety of designs have been successful over the years. Typically used in SUV's (Sport Utility Vehicles), a shade roller allows the cargo area to be obscured from view and restrains cargo in the cargo area from projectile motion in accidents or sudden stops. These shades are typically drawn from a roller cassette anchored adjacent the cargo area, either directly behind the rear seat (rear pull) between the trim panels of the rear cargo area, or along one trim panel of the cargo area (side pull). In either instance, the shade typically includes one or more ergonomic grips or handles to facilitate gripping by a human hand to deploy the shade, which is convenient to the person deploying the shade from the rear of the vehicle. To provide a comfortable gripping surface, the handle should preferably have a curved portion generally perpendicular to the shade panel portion to allow human fingers to engage the handle and provide a horizontal force, distributed along the pads of the fingers, rather than a thin or sharp edge which would concentrate the force and “dig” into the fingers.
There are also various known methods of storing flashlights in automobiles, as well as in other locations. Stowing a flashlight inside a vehicle, for example, can make a light source available in situations that must otherwise be navigated in the dark. This is particularly important in automotive vehicles that travel between lighted populated areas through areas which may not be lighted. Automotive engineers, however, are always searching for new ways to conserve space. Further, concerns of safety and convenience continue to drive the search for new ways to store and position supplemental light sources in automobiles.
It is thus desirable to provide a method of securely storing a removable light source at a location near the rear of a vehicle where it can be quickly and easily retrieved. The present invention is directed to solving one or more of the shortfalls or problems associated with related inventions.
SUMMARY OF THE INVENTION
In one aspect, a handle for an automobile shade roller assembly is provided. The handle includes a substantially D-shaped handle body having a holder for securing a removable light. The holder is positioned within a cavity defined by the handle body, and includes a plurality of holder members snap-fittingly engageable with the light.
In another aspect, a handle for a vehicle shade roller assembly is provided. The handle includes a substantially D-shaped handle body having an integrated security light holder for receiving and storing a security light in a removable fashion.
In still another aspect, a vehicle security roller shade is provided. The roller shade includes an extensible and retractable flexible shade body secured at one end to a roller assembly, and having an opposite end secured to a handle. The handle defines an interior storage cavity, and includes a holder for removably retaining a light member in the handle body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a shade handle according to the preferred embodiment of the present invention;
FIG. 2 is a bottom view of the shade handle of FIG. 1, illustrating an included flashlight in a stowed position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there are shown top and bottom views, respectively, of a shade handle 10 according to a preferred constructed embodiment of the present invention. Shade handle 10 comprises a D-shaped handle body 11 with an arcuate-shaped grip portion 21 connected to a holder portion 23 . Grip portion 21 preferably has a partially flattened bottom side 17 , and a top/upper side 19 which is also preferably partially flattened. Holder portion 23 is preferably substantially straight with a narrowed region 25 . Holder portion 23 has a top side 27 , which is preferably rounded, and defines a cavity 26 in a bottom side 29 , within which a security light holder is positioned (described below). Grip portion 21 and holder portion 23 each share a continuous inner edge 33 , which defines a central channel 14 . Channel 14 is located in the interior of handle body 11 and has a perimeter represented by inside edge 33 of handle body 11 . Preferably, this perimeter 33 is substantially parallel to an outside edge 35 of handle body 11 . Handle 10 may be manipulated by inserting one's hand through channel 14 , and gripping grip portion 21 .
Handle body 11 is preferably formed from a top piece 20 and a bottom piece 30 , and has a front side 18 and a rear side 16 . In a preferred embodiment, grip portion 21 is constructed in part by top piece 20 and in part by bottom piece 30 , while holder portion 23 is also constructed in part by top piece 20 and in part by bottom piece 30 . Top piece 20 preferably includes top side 27 of holder portion 23 , and a top side 22 of grip portion 21 . Bottom piece 30 preferably includes bottom side 17 of grip portion 21 . Bottom piece 30 may be textured or coated with a suitable rubber, or other high-friction material, to facilitate manual manipulation. It should be appreciated that the use of separate pieces merely represents one embodiment, and a handle of unitary construction might be made without departing from the scope of the present invention. Top piece 20 and bottom piece 30 preferably each define in part a set of two mounting apertures 32 positioned along the rear side 16 of handle body 11 , one of which is illustrated in FIG. 2 . In the preferred embodiment, handle body 11 is pivotably attached to an automobile shade (not shown) at its rear side 16 via mounting apertures 32 by a known method, for example, inserting mounting members (not shown) into mounting apertures 32 . Handle 10 may then be pivoted about the attached mounting members, which are secured to the shade. A person can thus grasp grip portion 21 and pull the attached shade to cover an automobile storage compartment or, alternatively, control the retracting motion of the attached shade while uncovering the automobile storage compartment.
Referring now in particular to FIG. 2, cavity 26 is preferably located within top piece 20 . A security light member 15 , illustrated as a conventional flashlight, is held by the security light holder within cavity 26 , which is preferably a trough with a slightly larger diameter than the associated security light 15 . The interior of cavity 26 conforms roughly in shape to the exterior surface of the light 15 . In this embodiment, the cross section of cavity 26 is generally U-shaped, however, this feature is dictated in part by the shape of the included light member, which might vary considerably, necessitating a different shaped cavity. The security light holder preferably comprises a plurality of holder members 28 positioned within cavity 26 , protruding into its interior. Each holder member 28 is preferably positioned in cavity 26 opposite another holder member 28 and separated by a distance that is slightly smaller than the diameter of security light 15 . Because top piece 20 is preferably constructed of a relatively flexible plastic, security light 15 can be snap-fit into cavity 26 in a manner known in the art. The preferred embodiment employs four holder members 28 , however, it should be appreciated that a different number of holder members, or even a different method altogether of securing security light 15 might be employed without departing from the scope of the present invention. Furthermore, the conventional flashlight illustrated need not be used; a light with a different shape might be utilized, along with a corresponding cavity shape. For example, it is contemplated that the light can be rectangular in cross section with its narrow dimension extending into the holder so as to reduce the span between the handle edge and the finger opening.
Returning to FIG. 1, holder portion 23 has a roughly oval aperture 12 , through which a portion of security light 15 is exposed. When detachment of security light 15 is desired, manual pressure may be applied to security light 15 via aperture 12 to push security light 15 free of cavity 26 , overcoming the force of holder members 28 . Because top piece 20 is constructed of a relatively flexible plastic material, as are holder members 28 , the downward force on security light 15 causes holder members 28 to flex outward, freeing security light 15 . In manufacturing handle 10 , it should be appreciated that the level of force necessary to disengage security light 15 from cavity 26 should be carefully calculated. Because cavity 26 faces a down direction in the preferred embodiment, the weight of security light 15 is continuously bearing down against holder members 28 , imparting a tendency for security light 15 to dislodge. Furthermore, inertial forces resulting from bumps and movements of handle 10 create a risk that security light 15 will fall from cavity 26 at an undesirable time if it is held too loosely. Conversely, if security light 15 is held too securely, it may not be quickly and easily available in an emergency, or provide too much resistance for young or elderly people or others with low hand strength. Thus, the relative flexibility of the plastic material from which top piece 10 is constructed, and the relative distance between oppositely positioned holder members 28 should be carefully selected to ensure sufficient holder strength, while still allowing quick and easy removal of security light 15 when desired.
An alternative embodiment might position the security light on the top of handle 10 , which would securely hold the light in place and require less clamping force from the holders. However, such an arrangement would tend to expose the light to view, making it aesthetically undesirable. Thus, in this alternate embodiment, it is preferred to have a cover over the cavity 26 , which can pivot or slide to expose the light for removal.
It should be understood that the present description is for illustrative purposes only, and should not be construed to limit the scope of the present invention in any way.
Those skilled in the art will appreciate that various modifications could be made to the disclosed embodiments without departing from the spirit and scope of the present invention. For instance, security light 15 might be affixed to handle 10 with Velcro™ or a similar material, or even with magnetic means. In addition, a different method of disengaging security light 15 might be used, such as a button with a return spring. Other aspects and features of the present invention will be evident upon examination of the attached drawing figures and appended claims. | A combination shade handle and light is provided comprising a handle body with a grip portion and a holder portion. The holder portion has a cavity for receiving and storing a security light. A plurality of holder members are provided which secure the security light in the cavity in a snap-fit fashion. The shade handle is attachable to an automobile shade roller assembly for covering an automobile storage compartment. In another aspect, a roller shade is provided having a handle with an integrated removable security light. | 1 |
This application is a National Stage completion of PCT/EP2013/057348 filed Apr. 9, 2013, which claims priority from German patent application serial no. 10 2012 209 166.1 filed May 31, 2012.
FIELD OF THE INVENTION
The present invention concerns a method and a device for controlling a mobile work machine.
BACKGROUND OF THE INVENTION
Work machines, particularly those used on building sites, are often required to reverse during working operation, i.e. to reverse their direction of movement. This can be carried out by a so-termed “power-shuttle” function. One possibility is to change the driving direction by virtue of a powershift in the main group by way of a reversing clutch gearbox. In addition a hydrodynamic torque converter is arranged between the engine and the reversing clutch gearbox. In this case the torque converter is used to brake the work machine when the driving direction is reversed. However, large energy losses occur at the torque converter during the braking. A possible way to reduce these energy losses is shown by DE 602 12 384 T2. This describes a method for reversing the driving direction of a moving vehicle, in which to reverse its driving direction the vehicle is braked by a service brake. It is true that in this case braking is not carried out by the engine and torque converter, but with this method significant energy losses occur at the vehicle's brakes.
SUMMARY OF THE INVENTION
The purpose of the present invention is therefore to propose a method and a device of the aforesaid type, which reduce energy losses when the mobile work machine is braked in order to reverse its driving direction.
According to the invention, this objective is achieved by virtue of the characteristics specified in the description below.
To reverse the driving direction of the work machine, it is proposed that braking should be carried out in a recuperative manner. In this way the braking energy used to carry out the driving direction reversal can be recovered and fed back to the work machine. This minimizes or avoids energy loss during braking.
The work machine can be braked recuperatively by means of a hybrid drive. The hybrid drive comprises a primary source of drive-power, in particular an internal combustion engine or the like, and a secondary drive-power source with an energy accumulator. In the latter the braking energy generated at the secondary drive-power source can be stored and fed back again to the secondary drive-power source of the work machine. As the secondary drive-power source, for example an electric machine with an electrical energy accumulator, which can be operated both as a generator and as a motor, or a hydraulic drive with a hydraulic accumulator, or a mechanical drive with a kinematic energy store can be provided.
A particularly simple way to brake the work machine in a recuperative manner, once a direction reversal command has been received at a first point in time, consists in operating an electric machine of a hybrid drive in the drive-train of the work machine as a generator. Preferably, this is continued until at a second point in time the work machine is virtually at rest and the torque transmission is changed from one driving direction clutch to the other with the work machine effectively at rest. The electrical energy produced by operating the electric machine as a generator during this can be fed to an electrical energy accumulator, for example an electric battery. Alternatively, it can be supplied directly to electric auxiliary aggregates. It is also conceivable for part of the energy produced recuperatively to be supplied directly to consumers and otherwise stored.
If in the drive-train of the work machine the electric machine is arranged in the force flow ahead of the driving direction clutches of a reversing clutch gearbox, then the driving direction clutch associated with the current driving direction is kept engaged until a speed of the work machine close to standstill is reached at the second point in time. During this the driving direction clutch associated with the new driving direction is closed before the second time-point is reached. This ensures a completely recuperative braking by the electric machine. Furthermore, the torque transmission from one driving direction clutch to the other can be carried out quickly and simply, for example powershifted by means of overlapping shifts when the work machine is almost at rest at the second point in time.
If in the drive-train of the work machine the electric machine is arranged in the force flow ahead of a hydrodynamic torque converter, then during the braking of the work machine it is advantageous for the converter bridging clutch of the torque converter to be closed or kept in the closed condition. When a predetermined lower rotational speed of the internal combustion engine is reached, which is preferably close to the stalling speed, the converter bridging clutch can be opened and held in the open condition, and the work machine is then braked to rest at the second time-point by means of a service brake or vehicle brake of the work machine. To change the torque transmission to the new driving direction, the driving direction clutch associated with the new driving direction can then be closed.
If in the drive-train of the work machine the electric machine is arranged in the force flow behind the torque converter, then during the braking of the work machine the converter bridging clutch of the torque converter can be changed to or kept in the open condition until the work machine is almost at rest at the second point in time. In this way the torque converter, which is not bridged during its operation, ensures a decoupling of the rotational speed of the internal combustion engine from the speed of the work machine during the braking process. This securely avoids stalling of the internal combustion engine and enables recuperative braking until, at the second time-point, a speed of the work machine close to standstill is reached.
Once the driving direction has been changed, the converter bridging clutch can be held in or brought to its open condition and the vehicle can be driven, for example accelerated by the internal combustion engine, in the new driving direction. When the converter bridging clutch reaches a predetermined operating point it is closed.
In the new driving direction, before and after closing the converter bridging clutch the work machine can be driven by the internal combustion engine and the electric machine, in each case alone or, for example in order to assist the internal combustion engine or the electric machine, together. For example, while driving in the new driving direction the dynamic of the internal combustion engine can be relaxed, whereby fuel consumption and emissions are reduced.
When the electric machine is arranged in the force flow ahead of the driving direction clutches, then during the braking of the work machine it is advantageous for the internal combustion engine to be decoupled from the drive-train by means of a separator clutch. This ensures that as much braking energy as possible is recuperated by the electric machine.
Following a successful change of the driving direction clutch, if the separator clutch is closed and the converter bridging clutch is opened or held open, the vehicle can be driven in the new driving direction by the internal combustion engine and/or by the electric machine. When the converter bridging clutch reaches a predetermined operating point it is closed and, to assist the internal combustion engine, at the same time the work machine is also driven by the electric machine.
Alternatively, after a change of the driving direction clutch the converter bridging clutch can be kept in or changed to its open condition and the vehicle can be driven in the new driving direction by the internal combustion engine and/or the electric machine. For example, by such electrical boosting, high rotational speeds and high power of the work machine can be produced as quickly as possible.
If in the drive-train of the work machine the electric machine is arranged in the force flow behind the torque converter, then after a change of the driving direction clutch the converter bridging clutch can be kept in or changed to its open condition and the vehicle can be driven in the new driving direction by the electric machine, whereas until it reaches an operationally required rotational speed and an operationally required torque the internal combustion engine follows on. In this way the fuel consumption and emissions of the internal combustion engine can be reduced.
When the driving direction clutch has been changed, during a transition phase the separator clutch can be kept in or changed to its open condition and the work machine can be driven by the electric machine, whereas until it reaches an operationally required rotational speed and an operationally required torque the internal combustion engine follows on and the separator clutch is then closed and the work machine is driven by the internal combustion engine.
Preferably, when the separator clutch is open the internal combustion engine is switched off. It is also conceivable, if a work drive output is arranged in the force flow ahead of the separator clutch, for the internal combustion engine to be operated in order to power the work drive output.
If the electric machine is arranged in the force flow behind the driving direction clutches, then at the first point in time the driving direction clutch associated with the current driving direction can be opened and the work machine can be braked by the electric machine until it comes to rest at the second time-point. This makes it possible to carry out the braking by means of the electric machine in a fully recuperative manner, with the internal combustion engine decoupled, until the work machine comes to rest at the second time-point.
If the driving direction clutches of the reversing gearbox are open, then driving can continue in the new driving direction by means of the electric machine, so that the internal combustion engine is not needed at all.
During this it is possible, when the work machine has come to rest at the second time-point and with the driving direction clutches open, to change the driving direction of the work machine by operating the electric machine with its rotational direction reversed.
Alternatively, before the second time-point has been reached the driving direction clutch associated with the new driving direction can be closed continuously and the propulsion of the work machine assisted, for example, by the internal combustion engine.
According to a further alternative, when the driving direction of the work machine has been changed the driving direction clutch associated with the new driving direction can be kept open and only when the work machine has reached a certain speed is it closed and the driving of the work machine assisted by the internal combustion engine. This reliably avoids stressing the driving direction clutches by a high starting torque and a large rotational speed difference.
Furthermore, after braking and bringing the work machine to rest at the second time-point, the driving direction clutch associated with the new driving direction can be changed to a slipping condition and the work machine can be started by the internal combustion engine and its movement at the same time assisted by the electric machine. During this it is conceivable to close the converter bridging clutch at an early stage and to carry out the starting process by the internal combustion engine and the electric machine only by way of the slipping driving direction clutch.
A further possibility is to keep the current driving direction clutch and the converter bridging clutch in the closed condition or change them thereto during the braking process. In this way the engine braking effect can be used for braking. To avoid stalling the internal combustion engine, when the internal combustion engine reaches a predetermined lower rotational speed limit the converter bridging clutch is opened and held in that condition, so that the work machine is braked to a standstill at the second time-point by the electric machine alone.
The work machine can also be braked by operating the electric machine as a generator and by means of the service brakes of the work machine. In this case the braking can be done both with a time offset and also simultaneously by the electric machine and by the service brakes.
The objective of the invention is also achieved by means of a device for controlling a mobile work machine having a reversing gearbox and a hybrid drive, in particular to carry out one of the above-described processes. The device according to the invention comprises a control unit connected to exchange signals with the drive-train of the work machine for implementing a powershifted driving direction reversal, by means of which unit at least one electric machine of the hybrid drive can be actuated for the recuperative braking of the work machine during the driving direction reversal.
For this purpose the control unit has a signal connection for detecting the accelerator pedal position, a signal connection for detecting a driving direction command from the driver, a signal connection for detecting a state of charge of the electrical energy accumulator for storing the energy recovered recuperatively and for supplying energy to the electric machine, signal connections for controlling the torque and rotational speed of the electric machine, signal connections for controlling the driving direction clutches of the reversing gearbox, and a signal connection for controlling the converter bridging clutch of the hydrodynamic torque converter. It is also conceivable to provide signal connections in the control unit for controlling the service brakes of the work machine.
It is advantageous for the control unit to be functionally integrated in a transmission control unit of the work machine.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, the present invention is explained in more detail with reference to the drawings, in which:
FIG. 1 : A first example shows three diagrams of various parameters as a function of time for a method according to the invention for carrying out a driving direction reversal of a mobile work machine;
FIG. 2 : A second example shows three diagrams of various parameters as a function of time for a method according to the invention for carrying out a driving direction reversal of a mobile work machine;
FIG. 3 : A schematic view of a control system for reversing the driving direction, relating to a drive-train of a mobile work machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show graphical representations of respective example embodiments of a method according to the invention for carrying out the driving direction reversal, for example from the forward to the reverse driving directions of a mobile work machine, although the procedure according to the invention can also be used for the converse direction change. In each case the diagram at the top shows the speed variation 1 , 5 of the work machine, the middle diagram shows the actuation sequence 2 , 3 , 6 , 7 of the driving direction clutches KF, KR, and the lower diagram in each case shows the torque variation 4 , 8 of the electric machine 9 (EM).
A first example embodiment of a method according to the invention, shown in FIG. 1 , relates to an arrangement of the electric machine 9 of a hybrid drive in the drive-train of the work machine, ahead of the driving direction clutches KF, KR in the force flow direction. Driven by the internal combustion engine 10 of the hybrid drive, the work machine first moves at a certain constant initial speed in the forward direction, as can be seen from the speed variation 1 . During this the driving direction clutch currently associated with the forward driving direction KF is at first kept closed and the driving direction clutch associated with the reverse driving direction KR is at first kept open, as can be seen from the actuation sequences 2 and 3 . When a driving direction command is received from the driver, the work machine is braked recuperatively (speed variation 1 , first time-point t 1 ). For this the electric machine 9 is operated as a generator and therefore produces a negative torque, as can be seen from the torque variation 4 . During this the speed of the work machine falls linearly to zero, which is reached at a second time-point t 2 . The actuation sequence 3 of the driving direction clutch associated with the reverse driving direction KR shows that it is closed in a linear and continuous manner as the second time-point t 2 corresponding to zero speed is approached, so that at the zero-speed second time-point t 2 the clutch KR is approximately half-closed. At that time point the driving direction clutch associated with the forward driving direction KF is opened abruptly, as shown by the corresponding actuation sequence 2 . Thus, the actuation sequences 2 and 3 overlap. In this way, shortly before the second time-point t 2 when the speed of the work machine reaches zero the driving direction clutches KF, KR are changed over to reverse the driving direction by a so-termed overlapping shift. Since the driving direction clutch associated with the forward driving direction KF is kept closed until shortly before the work machine comes to a standstill, it is ensured that the braking energy is recuperated by the electric machine 9 until the work machine has almost come to rest at the second time-point t 2 . After the driving direction change, in order to assist the internal combustion engine 10 the electric machine 9 is operated as a motor and produces a positive torque at constant acceleration until the constant initial speed is reached in the new, reverse direction (speed variation 1 , third time-point t 3 ), when the electric machine 9 is switched off.
A second example embodiment of a method according to the invention for carrying out a driving direction reversal, shown in FIG. 2 , relates to an arrangement of the electric machine 9 behind the driving direction clutches KF, KR in the drive-train. With this arrangement braking by the electric machine 9 can be carried out with the driving direction clutches KF, KR open. For this, at the beginning of the braking process the driving direction clutch currently associated with the forward driving direction KF is opened abruptly, as can be seen from the actuation sequence 6 (first time-point t 1 ). In this way, during the braking process the internal combustion engine 10 is decoupled from the drive input and from the electric machine 9 . Consequently, almost until the work machine has come to a standstill (at the second time-point t 2 ) the braking energy can be recuperated completely by the electric machine 9 , as indicated by the negative torque variation 8 . During this, as shown by its actuation sequence 7 the driving direction clutch associated with the reverse driving direction KR is at first held in the open condition. Close to the zero-speed time-point (second time-point t 2 ) of the work machine, as shown by the speed variation 5 and in accordance with the actuation sequence 7 the driving direction clutch associated with the reverse driving direction KR is closed continuously in a linear manner as in the method according to FIG. 1 , and after the driving direction has changed the internal combustion engine 10 is assisted by a positive torque variation 8 provided by the electric machine 9 during acceleration in the new driving direction.
FIG. 3 shows an example of a mobile work machine, with reference to which a device according to the invention for controlling a powershifted driving direction reversal in a mobile work machine will be explained.
The drive-train comprises an internal combustion engine 10 , an electric machine 9 and a reversing gearbox 11 for reversing the driving direction of the work machine, the gearbox comprising, at least, respective driving direction clutches KF, KR for the forward and reverse driving directions and a reversing gearset, as well as a main transmission which is connected to the differential Diff of the drive axle of the work machine. The internal combustion engine 10 and the electric machine 9 form a so-termed parallel hybrid. In the drive-train they are arranged in the force flow one behind the other, so that they can act conjointly upon the drive-train. The electric machine 9 is arranged in the force flow between the internal combustion engine 10 and the transmission input of the reversing gearbox 11 . In the drive-train the internal combustion engine 9 can produce a torque T and a rotational speed n in the drive-train. Conversely, from the drive-train a torque T and a rotational speed n can be transmitted to the internal combustion engine 10 .
In the drive-train, in the force flow the reversing gearbox 11 comprises one behind the other a hydrodynamic torque converter TC with a converter bridging clutch LC, at least driving direction clutches KF, KR for the forward and reverse driving directions, a reversing gearset and a powershift transmission as the main transmission. In this case a plurality of forward gears of the powershift transmission are associated with one driving direction clutch KF and one reversing gear is associated with the other driving direction clutch KF. The torque converter TC with its converter bridging clutch LC is arranged in the force flow between the internal combustion engine 10 and the driving direction clutches KF, KR. The powershift transmission is in driving connection with a differential of a driven axle of the work machine, which distributes the drive power produced in the drive-train to the wheels of the axle.
To select an appropriate strategy for reversing the driving direction of the work machine, a control unit 12 detects signals from the system components and evaluates them. To carry out the driving direction reversal the system components can be actuated by the control unit 12 . In an electrical energy accumulator 13 (ACCUM), in this case an electric battery, the electrical energy E produced recuperatively by the electric machine 9 during braking can be stored and returned again to the electric machine 9 as necessary.
The electric signal flow connections or signal connections are in each case indicated by arrows. The control unit 12 detects the accelerator pedal position AccPos, the driver's driving direction command DriveDir, the state of charge SOC of the electric battery 13 , the torque T EM and the rotational speed n EM of the electric machine 9 and the operating condition of the converter bridging clutch LC. To carry out the driving direction reversal the torque T EM and the rotational speed n EM of the electric machine 9 , the converter bridging clutch LC, the driving direction clutches KR, KF and if necessary the service brakes BRAKE of the work machine that act on the wheels can be actuated by the control unit 12 .
Alternatively, a separator clutch SC for decoupling the internal combustion engine 9 from the drive-train can be arranged between it and the electric machine 10 , the operating condition of the separator clutch SC being detected by the control unit 12 so that the separator clutch SC can be actuated by the control unit 12 .
INDEXES
1 Speed variation
2 Actuation sequence
3 Actuation sequence
4 Torque variation
5 Speed variation
6 Actuation sequence
7 Actuation sequence
8 Torque variation
9 Electric machine
10 Internal combustion engine
11 Reversing gearbox
12 Control unit
13 Electrical energy accumulator
E Energy
T Torque
n Rotational speed
AccPos Signal connection for accelerator pedal position
DriveDir Signal connection for driving direction command
SOC Signal connection for state of charge of the battery or energy accumulator
TEM Signal connection for the torque of the electric machine
nEM Signal connection for the rotational speed of the electric machine
LCS Signal connection for the converter bridging clutch
KFS Signal connection for a current/forward drive direction clutch
KRS Signal connection for an other/reverse drive direction clutch
BRAKE Signal connection for the service brakes
t 1 First time-point, start of recuperation
t 2 Second time-point, work machine at rest
t 3 Third time-point, electric machine switched off
VFz Speed of the work machine
Diff Differential of the drive axle of the work machine | A method of controlling a mobile work machine having a reversing gearbox. The driving direction reversal is initiated by detecting a driving direction reversal command. A change of the torque transmission from a current driving direction to a new driving direction is carried out as a powershift. Braking for the driving direction reversal occurs in a manner so as to recuperate energy. Furthermore, a device for controlling a mobile work machine, in particular for implementing the method, is also disclosed. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The instant invention relates generally to tire cleats and more specifically it relates to an improved traction device for a tire on a driven wheel of a motor vehicle.
2. Description of the Prior Art
Numerous cleats have been provided in prior art. For example McKenzie U.S. Pat. No. 998,369 ; Bixby et al U.S. Pat. No. 1,169,525, to Younglove U.S. Pat. No. 2,449,033 and Dyrdahl U.S. Pat. No. 4,159,731 all are illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.
The patent to McKenzie, U.S. Pat. No. 998,369 teaches an anti-skid device including an arcuate plate adapted to embrace a tire transversely and having a tread face concave from edge to edge of the plate forming a chain seat. Lugs are arranged adjacent to the longitudinal edges of the chain seat. A means is for securing the plate to a wheel tire. A link chain lying in the valley of the concave chain seat has terminal hooks removably and pivotally engaging the securing means. The chain being swingable bodily to a slight degree in the concave seat, whereby the chain constantly clears itself of accumulations. The movement of the chain being limited by contact with the outwardly curving longitudinal sides of the seat valley. Contact with and consequential mutual erosion of the lugs and chain when under load is positively prevented.
The Bixby et al. U.S. Pat. No. 1,169,525 teaches an anti-skidding device of the class described, the combination of a plurality of plates. Each of the plates comprising a body having flat inner surfaces being adapted to rest upon the outer periphery of a tire. A body portion is formed integral upon the plate adjacent each corner thereof. A central base is formed upon the plate. Transversely extending ribs are formed upon the bodies and base. The ribs extend for a considerable distance beyond the outer surfaces of the plate. The ribs being adapted to hold the plate against slipping. A means is for holding the plate in engagement with the outer portion of a tire.
The Younglove U.S. Pat. No. 2,449,033 teaches a traction device for use on a tire and attachment to the out-turned side flanges of a tire-retaining rim comprising a hook-shaped member adapted to straddle the tire and provided on one end with gripping lugs adapted to seat against one of the flanges. The member having at its other end a reduced tongue adapted to extend alongside the other of the flanges. An end thumb screw in the tongue is adapted to be turned against the other flange. The screw coacts with the lugs to clamp the member to the outer sides of the flanges.
The Dyrdahl, U.S. Pat. No. 4,159,731 teaches a traction device for vehicle wheels is provided comprising spaced traction plates having traction bars extending from both major surfaces thereof. The plates being interconnected by U-shaped tire side wall gripping elements. The device being expandable to span tires of different widths. A spring biased shoe carried by the bight portion of one of the U-shaped gripping elements is adapted to more tightly grip the tires as forces tending to pull the device from the tire are applied. The shoe is easily manually released to remove the device from a tire.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide an improved traction device that will overcome the shortcomings of the prior art devices.
Another object is to provide an improved traction device for a tire on a driven wheel of a motor vehicle, having a studded base to produce traction when stuck on ice, snow or any other slippery road surface.
An additional object is to provide an improved traction device that contains a clamping structure for the studded base that can quickly attach to and detach from the side walls of the tire and be adjustable thereto in order to fit different sized tires.
Still an additional object is to provide an improved traction device which applies pressure against both sides of the tire in order to secure the device to the tire, the amount of pressure being predetermined so as to prevent the side wall of the tire from becoming dislodged from the driven wheel.
A further object is to provide an improved traction device that is simple and easy to use.
A still further object is to provide an improved traction device that is economical in cost to manufacture.
Further objects of the invention will appear as the description proceeds.
To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
Various other objects, features and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is la front perspective view of a motor vehicle in snow or ice, showing the instant invention installed on a tire of a drive wheel.
FIG. 2 is a rear perspective view of the instant invention per se taken in the direction of arrow 2 in FIG. 1.
FIG. 2A is a cross sectional view taken along line 2A--2A in FIG. 2.
FIG. 3 is a front perspective view taken in the direction of arrow 3 in figure, with the tire and wheel broken away.
FIG. 4 is a rear elevational view taken in the direction of arrow 4 in FIG. 3.
FIG. 5 is a top view taken in the direction of arrow 5 in FIG. 2.
FIG. 6 is a front perspective view of a portion thereof with parts broken away taken in the direction of arrow 6 in FIG. 3, with the lever lifted up.
FIG. 7 is a cross sectional view taken along line 7--7 in FIG. 6 with parts broken away.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, FIGS. 1 through 7 illustrate an improved traction device 10 for a tire 12 on a driven wheel 14 of a motor vehicle 16 comprising a base 18 adapted to rest longitudinally upon the tread 20 of the tire 12. A facility 22 is for securing the base 18 to the tire 12. A structure 24 on the base 18 is for providing traction when the tire 12 is stuck on ice/snow 26 and any other slippery road surface.
The base 18 includes a slightly curved inner concave surface 28, to best fit up against the tread 20 of the tire 12. The slightly curved inner concave surface 28 of the base 18 is serrated to better grip and prevent slippage of the base 18 on the tread 20 of the tire 12, especially at the moment of rotation when the tread 20 of the tire 12 presses down onto the base 18.
The securing facility 22 is an adjustable clamp assembly 30 extending from longitudinal sides 32, 34 of the base 18, so as to hold onto the side walls 36, 38 of the tire 12 so as to apply pressure against both sides of the tire 36, 38 to secure the improved traction device 10 to the tire 12. The base 18 includes a greater curved convex outer surface 40, to best conform to the tread 20 of the tire 12. The traction structure 24 consists of a plurality of studs 42 extending away from the greater curved convex outer surface 40 of the base 18.
The adjustable clamp assembly 30 contains a rear jaw 44. A facility 46 on the first longitudinal side 32 of the base 18 is for adjusting in a retained course manner the rear jaw 44. A front jaw 48 is also provided. A facility 50 on the second longitudinal side 34 of the base 18, is for adjusting in a retained normal manner the front jaw 48. A facility 52 on the second longitudinal side 34 of the base 18 is for adjusting in a retained fine manner the front jaw 48, so that the rear jaw 44 and the front jaw 48 will butt up against the opposite side walls 36, 38 of the tire 12.
The rear jaw 44 includes an inner concave surface 54 to conform to the rear side wall 36 of the tire 12. The front jaw 48 includes an inner concave surface 56, to conform to the front side wall 38 of the tire 12. The inner concave surface 54 of the rear Jaw 44 is serrated, to better grip and prevent slippage on the rear side wall 36 of the tire 12. The inner concave surface 56 of the front jaw 48 is serrated to better grip and prevent slippage on the front side wall 36 of the tire 12.
The coarse adjusting facility 46 consists of the slightly curved inner concave surface 28 of the base 18 having a pair of spaced apart transverse grooves 58 extending from the first longitudinal side 32. Each groove 58 has a plurality of forwardly angled holes 60 therealong. The rear jaw 44 has a pair of spaced apart curved arms 62. Each arm 62 has a straight portion 64 sized to fit into one groove 58. Each straight portion 64 has a plurality of forwardly angled fingers 66 therealong, to adjustably snap fit into the forwardly angled holes 60 in the matching groove 58.
The normal adjusting facility 50 includes the base 18 having three spaced apart transverse apertures 68, 70, 72 extending from the second longitudinal side 34. The second middle aperture 70 has a plurality of spaced apart transverse side slots 74. A pair of guide pins 76, 78 extend from the front jaw 48 into the first and third transverse apertures 68, 72 in the base 18 in an adjustable manner. A shaft 80 extends through the front jaw 48 and into the second middle aperture 70 in an adjustable manner. A plurality of spaced apart stub posts 82 are on the shaft 80. When the shaft is rotated ninety degrees, the stub posts 82 will enter and engage with the transverse side slots 74, to lock the shaft 80 into position.
The fine adjusting facility 52 contains a pivot cam 84 rotatively connected off center to an outer distal end of the shaft 80. A lever 86 is connected to the pivot cam 84. When the lever 86 is rotated against the front jaw 48, the pivot cam 84 will gently press against the front jaw 48, to allow the front jaw 48 to apply a pre-determined amount of pressure against the front side wall 38 of the tire 12, to retain the base 18 in place and to prevent the side wall of the tire 12 from being dislodged from the driven wheel 14.
The front jaw 48 includes a pair of spaced apart lugs 88 extending from an outer surface 90 between the lever 86, when the lever is rotated against the front jaw 48. A shackle 92 of a padlock can engage with the lugs 88 to lock the lever 86 in place against the front jaw 48.
LIST OF REFERENCE NUMBERS
10--improved traction device
12--tire
14--driven wheel
16--motor vehicle
18--base of 10
20--tread of 12
22--securing facility of 10
24--traction structure on 18
26--ice/snow
28--slightly curved inner concave surface of 18
30--adjustable clamp assembly
32--first longitudinal side of 18
34--second longitudinal side of 18
36--rear side wall of 12
38--front side wall of 12
40--greater curved convex outer surface of 18
42--stud of 24
44--rear jaw
46--coarse adjusting facility on 32
48--front jaw
50--normal adjusting facility on 34
52--fine adjusting facility on 34
54--inner concave surface of 44
56--inner concave surface of 48
58--transverse groove in 28
60--forwardly angled hole in 58
62--curved arm
64--straight portion of 62
66--forwardly angled finger on 64
68--first transverse aperture in 18
70--second transverse aperture in 18
72--third transverse aperture in 18
74--transverse side slot in 70
76--guide pin into 68
78--guide pin into 72
80--shaft into 70
82--stub post
84--pivot cam on 80
86--lever
88--lug on 90
90--outer surface of 48
92--shackle of 94
94--padlock
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A traction device for a tire for a driven wheel of a vehicle includes a base for resting circumferentially upon the tread of a tire. The device includes an adjustable clamp assembly extending across the base longitudinally and includes a front and a rear jaw which, when mounted, hold onto the sidewalls of the tire. The front jaw is adjustable in any and all of three different settings: coarse, normal and fine. | 1 |
BACKGROUND AND SUMMARY
The present invention relates generally to building constructions. More particularly, this invention relates to snap-fit assemblies for retaining greenhouse structural panels.
Present day greenhouses can be constructed with a number of different coverings. For example, greenhouses have been covered with thin, flexible plastic sheeting which is often available at low cost. This plastic sheeting is typically secured to the structural support members of the greenhouse. Various clip arrangements have been employed for this purpose. Many of these clips are constructed from aluminum. However, plastic sheeting often has to be replaced since it was easily damaged by wind, rain, and normal wear and tear.
As an alternative to plastic sheeting, plate glass can be used to cover the greenhouse. In order to connect glass to the structural support members of the greenhouse, a different type of fastening system is used. This fastening system needs to securely retain the relatively heavy panels but without breaking or cracking the glass.
Since glass panels break relatively easily, plastic panels have been employed instead. Presently, a number of different types of plastic structural panels are being used on greenhouses. One particular type of plastic panel is called polycarbonate structural sheeting and is sold by Polymark of Janesville, Wis. Polycarbonate sheets have several advantages over the glass structural panels. For example, while polycarbonate sheets can use similar fastening systems as glass sheets, polycarbonate sheets are less easily broken. Also, polycarbonate sheets can provide better insulating characteristics than glass sheets in many applications.
The present invention provides novel improvements to clip-type fastening systems used to connect greenhouse structural panels together. In the greenhouse industry, translucent structural panels, such as those of glass or polycarbonate, are connected to each other and also to the supporting structure or underlying framework of the greenhouse. Prior fastening or connecting clips have also been made from polycarbonate materials. One type of polycarbonate clip is called an H-Clip Profile and is available from Polymark of Janesville, Wis. The H-Clip Profile has been used for side wall and roof constructions in greenhouses. This device is a two-piece interlocking base and cap fastening system which can incorporate many of the desirable characteristics of polycarbonate sheeting. H-Clip Profile fastener systems are typically much lower in cost than comparable fastener systems formed from aluminum. Polycarbonate clips have better light transmission and thermal insulation characteristics than aluminum clips. Further, H-Clip Profiles have no exposed fasteners to the underlying framework. Their secure, interlocking grip can create a weather-tight seal without the use of neoprene gaskets. H-Clip Profiles have considerably less weight than metal fastener systems. Thus, shipping and construction costs are reduced and, at the same time, load stress on the greenhouse support structure is decreased. However, while the H-Clip Profile has a number of advantages over the prior fastener systems, it does not provide a uniform fastening system for structural panels having significantly different thicknesses. Also, this fastener system does not provide the same thermal insulating efficiencies as the structural panels it connects.
Another polycarbonate fastener is called an H-Profile. This is a single piece device and is also available from Polymark. H-Profiles include a plurality of opposing recesses for receiving the edges of structural panels. To install the panels, this clip is slid into position from one end of each panel. With H-Clip Profiles, on the other hand, the panels are set in place on the base and the cap is subsequently snap-fit into the base. However, both of these fastener devices support and retain the structural panels between substantially flat surfaces.
Various other panel fastener systems are known which are formed from materials other than polycarbonate. It has been known, for example, to provide a two-piece clip assembly with the separate members connected together by mating projections. These projections typically have a series of mutually interlocking teeth thereon to permit the separate members to be secured at selected distances to accommodate a particular panel thickness. However, without the use of additional clip assembly elements, these devices are not known to secure two panels together which each have a different thickness.
Other two-piece clip assemblies are known to have some flexibility in the cap member so as to bias the panels toward the base member. However, these typically secure the panels over a broad surface rather than at discrete points. Also, such devices often require compressible gaskets to provide proper sealing.
Therefore, it is an object of this invention to provide an improved fastening system.
It is another object of this invention to provide a fastening system that can accommodate a wide range of thicknesses of structural panels while using a uniform cap and a uniform base member.
A further object is to provide a fastening system that does not significantly restrict the transmission of light into the greenhouse.
Still another object is to provide a fastening system that has the same thermal characteristics as the structural panels being held.
Yet another object is to provide a fastening system with a base member that can be attached to a support purlin by various fasteners through the longitudinal center axis of the base member without effecting the fastening means of the system.
Yet still another object is to provide a clip arrangement that is self sealing to water and air.
A still further object is to provide a two-piece clip assembly for securing two panels each having a different thickness.
These and other objects of the present invention are attained by the provision of a fastener system having two mutually interlocking clip members, each clip member including a connection element and a pair of panel retaining walls. The connection element of one clip member is received and retained by the connection element of the other clip member through a series of interlocking hooks. The panel retaining walls of the cap clip member are flexibly arched and each includes a plurality of discrete panel engaging projections. The base clip member receives each panel on its retaining walls and can locate the panel ends against the connection element. The panel retaining walls of the cap clip member are independently flexible to permit each panel to have a different thickness. The discrete panel engaging projections are biased by the arch of the retaining walls to ensure proper sealing and secure panel retention.
The connection elements of the present invention are specially adapted to assist in retaining two panels, each having a different thickness. Each connection element includes spaced-apart arms having interlocking hooks formed thereon. Each hook arm of one connection element cooperates with a hook arm of the other connection element to act as a panel locking set. Within each such set at least one arm includes a plurality of spaced hooks such that different vertical spacing between clip members can be secured. Each locking set is operationally associated with the clip member retaining walls for a given panel and can be adjusted independently of the other locking set to establish different spacing for its retaining walls resulting in different thicknesses of panels being secured.
The components of the present invention are preferably formed from light transmitting materials, such as translucent polycarbonate. At the same time, additional barriers can be provided in the connection members to improve thermal insulation. Also, each set of spaced apart arms are spaced apart sufficiently to allow fasteners to be disposed within the connection member to secure the fastener system to the underlying support structure.
Other objects, advantages and novel features of the present invention will now become readily apparent upon consideration of the following description of preferred embodiments in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-sectional view of a fastening system embodying the present invention prior to assembly.
FIG. 2 shows a cross-sectional view of the fastening system of FIG. 1 after assembly.
FIG. 3 is a cross-sectional view of a cap member of an alternative embodiment of the present invention.
FIG. 4 shows a cross-sectional view of the fastening system of FIG. 1 clamping two panels each of different thicknesses.
FIG. 5 is a top plan view with portions broken away of the fastening system of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a preferred embodiment of the present invention. A base member 10 is shown secured to a structural supporting member or purlin 12 by fastener 14. Base member 10 has outwardly extending bottom walls 16 for supporting and locating structural panels 18. Two spaced-apart arms 20 and 22, extend upwardly from walls 16, substantially parallel to axis Z--Z, and preferably continue the longitudinal length x--x of the bottom walls. Arms 20 and 22 are, for example, spaced an equal distance from each other over their entire lengths. Arms 20 and 22 can also serve as a stop to locate panels 18 in position prior to engagement of cap 26 into the base 10. Arms 20 and 22 are preferably integrally formed with bottom walls 16 and made of a resilient material having sufficient flexibility and resiliency to allow engagement with the arms of cap 26 as described below, and yet have sufficient strength to hold cap portion 26 in position as the cap and base clamp the panels 18 in position.
Arms 20 and 22 include hooks 28 and 30, and 32 and 34 respectively, extending inwardly from the arms towards the axis Z--Z of FIG. 1. These hooks form notches 36 and 38 and 40 and 42 which face inwardly towards axis Z--Z. Two sets of notches are show in the drawing, for illustrative purposes, although additional sets of notches are contemplated. The number and spacing of the sets of notches correspond generally to the thickness of the panels to be connected by the particular fastening apparatus. Arms 20 and 22 form a recess 44 between them. Recess 44 has sufficient width to allow fastener 12 to be disposed within, in order to attach base member 10 to support 12. Recess 44 is spaced apart from wall 24 by an inner wall 46 extending from one arm 20 to the other arm 22 preferably over the longitudinal length of the base. This inner wall 46 extends, for example, substantially parallel to wall 20 and is spaced from wall 20 to form a dead air space 48 which helps to provide the base with better thermal insulating characteristics.
The fastening system of this invention also includes cap 26 having a reinforced middle section 50 with arms 52 and 54 extending outwardly from wall 56. Arms 52 and 54 are preferably substantially parallel to the Z axis of FIG. 1, and wall 56 is, for example, arched or crescent-shaped in cross section. Arms 52 and 54 are preferably integrally formed with wall 56. Arms 52 and 54 cooperate with arms 20 and 22 of base 10 to provide the panel locking means of the fastening system. Arms 52 and 54 extend, for example, along the longitudinal length of cap 26. An inner wall 58 is provided which is spaced apart from surface 56 of cap 26 to form another dead air space 60. As with wall 46, inner wall 58 preferably extends the longitudinal length of cap 26.
Composite wall 62 includes a first set of cantilevered and flexible arms 64 and 66 attached to reinforced base section 50 on one side. Attached to the other side is a second set of cantilevered and flexible arms 68 and 70 extending outwardly with the first set of arms. Arms 64, 66, 68, and 70 attach together with wall 56 to form a crescent-shaped or arched cross-section of the outer composite wall 62 ofo cap 26. Wall 62 has a third set of intermediate arms 72 and 74 extending outwardly from the connection of arms 64 and 68 and 66 and 70, respectively, typically extending the length of the cap parallel to each other. These arms are preferably substantially parallel to arms 52 and 54 when the cap is not engaged in base 10. Intermediate arms 72 and 74 provide additional contact or interface surfaces to further retain a structural panels 18 between the cap 26 and the base 10 when the cap is secured in the base. Intermediate arms 72 and 74 also provide additional strength to wall 62. In alternative embodiments, these intermediate arms can be constructed of various configurations or left out entirely as seen in FIG. 3 depending on the desired biasing forces or thickness of the structural panels to be fastened.
Arms 52 and 54 of the cap 26 are provided with hooks 76 and 78 protruding outwardly away from axis Z--Z and from the arms. These interlocking hooks are made to cooperate with hooks 28, 30, 32 and 34 of base 10. Inclined surfaces on hooks 28, 30, 32, 34, 76 and 78 help ease the insertion of cap 26 into base 10. The surface of the hooks 76 and 78 act as inclined planes pushing the arms 20 and 22 of the base outwardly and the arms 52 and 54 of the cap in as both can resiliently flex during insertion of the cap member. After sliding past hooks 28 and 32, hooks 76 and 78 of the cap are inserted within recessed portions or notches 36 and 40 of the base and, thereupon, the arms 52 and 54 spring back into position to hold cap and base together.
If there is insufficient holding force of the structural panels at this stage of insertion, cap 26 is forced further into base 20. Hooks 76 and 78 again force arms 20 and 22 outwardly and arms 52 and 54 inwardly as hooks 76 and 78 are pushed past hooks 30 and 34 of base 10 into recessed areas 38 and 40. This position is typically used when panels of smaller thickness are connected.
As illustrated in FIG. 1 and FIG. 2, when connecting panels of similar thickness, depending on the thickness of the panel to be secured, the hooks 76, 78 are engaged in recessed areas 36 and 40 or 38 and 42. Three pairs of cantilevered and flexible arms 64 and 66, 68 and 70, 72 and 74 provide the biasing forces.
The clip arrangement of this invention can hold differently sized structural panels together. For example, both 6 mm and 7 mm panels are connectable as the hooks 76 and 78 are, for example, connected within the notches 38 and 42 respectively. The 7 mm panels are typically held somewhat tighter than the 6 mm panels, yet both panels are adequately secured in place. The crescent shape and flexible characteristics of the polycarbonate material of wall 62 are believed to allow this biasing force to hold both sizes. When 10 mm and 12 mm sheets are to be connected, hooks 76 and 78 are, for example, held within notches 36 and 40, respectively.
In addition, as seen in FIG. 4, recessed portions 36, 38, 40 and 42 have sufficient depth to allow cap member 26 to be cocked in base 10 and still be securely engaged. As illustrated, hooks 76 and 78 can be engaged in recessed areas 38 and 40. In this position, a structural panel 118 relatively of small thickness can be connected to a structural panel 218 of relatively large thickness. Crescent shaped wall 62 provides biasing force to secure this type of connecting. This is believed to be possible because such of the three sets of arms 68 and 70, 64 and 66, 72 and 74 interact to provide resilient forces against the surfaces of panels 18 by way of resilient hinge joints A, B, and C.
Thus, it can be seen walls 16 and 62 form snap-fit panel receiving chambers between each other with an intermediate chamber formed by walls 28, 32, 52, and 54. This intermediate chamber includes two dead air insulating layers and an independent variable interlocking arrangement. The dead air layers serve a similar function as dead air layers 120 and 220 in the panels. At the same time, the walls defining the intermediate chamber provide positive location for the panels.
The clip arrangement is self-sealing at the end of wall 62 at arms 68 and 70 and at the end of arms 72 and 74 to provide a double seal. When the base, cap, and panel are made of the same material, preferably polycarbonate, there is typically no significant difference in the coefficient of thermal expansion between the components despite changes in environmental temperature. The resilient nature of the material also contributes to the sealing effect of the clip.
As seen in FIG. 3, the cap 26 can alternatively be constructed without wall 58 and arms 72 and 74. With this embodiment, arms 352 and 354 are forced outwardly away from axis Z--Z when arched wall 362 is flattened by engagement with a panel. This results in arms 352 and 354 being forced tightly within corresponding notches. The cap is hinged at joints 400 during this movement.
The translucent fastening system of the present invention provides for light to be transmitted into the building through the fastening system as well as the panels.
Some embodiments can use a cap member made from polycarbonate or another plastic material with the base member of aluminum. Other preferred embodiments include the base member formed integrally with the structural supporting member 12. In particular, where the structural member would restrict light transmission an integrally formed arrangement of aluminum could be used. The base would have a positive connection to the structural member and simplify construction of the building.
Although the present invention has been described in detail, the same is by way of illustration and example only and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims. | A two-piece fastening arrangement for joining two structural greenhouse panels. The fastener is capable of connecting a wide range of thicknesses of structural panels. A cap member snaps into a base member and biases the structural panels between the cap and base. The snap engagement is between two sets of cooperative arms extending from each member, one member having hooks which are inserted into recessed areas or notches of the other member. The notched member has a plurality of notches in the arms making the fastener capable of connecting a wide range of different width panels. The cap member has a crescent shape to bias the structural panel and improve the sealing of the joint. With the crescent shape and size of the notches, different thicknesses of panels can be connected to each other with a uniform fastener. | 4 |
RELATED APPLICATIONS
This application claims benefit of U.S. Provisional Patent Application No. 60/201,304, filed May 2, 2000 and entitled “VOICE-OPERATED RADIO INTERFACE.”
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to communications. More specifically, this invention relates to a communications interface between two or more disparate systems.
2. Description of Related Art
Public crisis events (such as natural disasters or terrorist actions) may demand responses by several public safety agencies, including police, firefighters, and medical and rescue services. In order for these agencies to deploy their services more effectively and remediate the situation more quickly, it is critical to establish command and control communications with as little delay as possible. Therefore, it is desirable at least for the commanders of first response agencies to be able to communicate with one another in order to coordinate their operations at the scene. Unfortunately, a lack of interoperability (i.e. useable connectivity) between the communications apparatus of many such organizations often impedes such cooperation in practice. A similar deficiency may arise when military units require real-time transfer of information but utilize dissimilar radio-frequency bands and/or modulation schemes.
A proposed solution to this problem is a central device to receive all of the various RF signals and rebroadcast them over the appropriate RF bands. Such a device, however, is large and bulky, must be transported rather than carried, requires the on-site availability of significant power resources, requires highly trained personnel to set up and operate, and is expensive both to purchase and to maintain. A portable and rapidly deployable device that provides such interoperability has not yet existed, much less a device that has such features combined with ease of operation and low cost.
SUMMARY OF THE INVENTION
An interface according to an embodiment of the invention includes a number of input/output (I/O) ports, a corresponding number of voice-operated-transmit (VOX) circuits, and a switching matrix.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of an interface 100 according to an embodiment of the invention;
FIG. 2 illustrates an exemplary application of an interface 100 ;
FIG. 3 shows a block diagram of a VOX circuit 20 according to an embodiment of the invention;
FIG. 4 shows a schematic diagram of a priority circuit 150 according to an embodiment of the invention;
FIG. 5 shows a block diagram of an alternate implementation 22 of a VOX circuit according to an embodiment of the invention;
FIG. 6 shows a block diagram of a switching matrix 30 ;
FIG. 7 shows an alternate implementation 32 of a switching matrix according to an embodiment of the invention;
FIG. 8 illustrates an exemplary application of an alternate implementation 102 of an interface according to an embodiment of the invention;
FIG. 9 shows a block diagram of the alternate implementation 102 of an interface according to an embodiment of the invention;
FIG. 10 shows a block diagram of an input port 12 ;
FIG. 11 shows a schematic diagram of an input select circuit 360 ;
FIG. 12 shows a block diagram of a supply voltage monitor circuit 300 ; and
FIG. 13 shows a block diagram of an alternate implementation 302 of a supply voltage monitor circuit.
DETAILED DESCRIPTION
FIG. 1 shows a block diagram of an interface 100 according to an embodiment of the invention. Interface 100 connects to a number of communications devices via input/output ports 10 . Specifically, interface 10 receives an input signal S 10 from, and transmits an output signal S 16 and a PTT (push-to-transmit) command S 60 to, the communications device connected to each input/output port 10 .
Interface 100 includes a number of VOX circuits 20 , each receiving a input signal S 10 via the respective I/O port 110 . Each VOX circuit is also coupled to a common control bus that carries a priority signal S 50 to the VOX circuits 20 . In accordance with these inputs, each VOX circuit 20 outputs a channel activation signal S 30 to a switching matrix 30 and a PTT command S 60 through the respective I/O port 10 . As described below, the VOX circuits 20 may be identical to one another, or one or more of the VOX circuits 20 may be adjusted or constructed differently from another according to the characteristics of a particular communications device.
Interface 100 also includes a switching matrix 30 that receives the input signals S 10 and channel activation signals S 30 and produces the output signals S 16 accordingly. In the signal paths between I/O port 10 and switching matrix 30 , it may be desirable to provide circuits (active and/or passive) that perform signal conditioning operations such as RF suppression, DC blocking, lowpass filtering, and/or signal level adjustment (not shown).
FIG. 2 shows a block diagram of an application of interface 100 . In this example, communications devices 1 A- 1 D include portable two-way radios (e.g. ‘walkie-talkies’, transceivers) that may communicate on different bands (such as HF, VHF, UHF, sideband, etc.) and/or using different modulation schemes, and one communications device 1 is provided for each communications path to be supported. Because the communications devices 1 A- 1 D used to support the various paths are stand-alone off-the-shelf units, they can be replaced easily and individually in case of failure. Moreover, adding a communications path to a new service group may be performed easily on-site, e.g. by simply connecting a communications device drawn from one of the members of that group to interface 100 as described below. Further implementations of interface 100 extend such interoperability to other communications devices such as cellular and wireline telephones, 3-wire or 4-wire intercoms, tape recorders, and one-way radios.
Each communications device 1 is connected to a corresponding I/O port 10 through a signal and control cable 220 that carries input signal S 10 , output signal S 16 , and PTT command S 60 . Cable 220 may terminate at either end with one or more standard connectors (such as 2.5- or 3.5-mm miniature audio plugs), and/or specialized connectors may be used, depending upon the particular physical characteristics of the associated communications device. It is also possible for the audio and PTT command signals to be carried between port 10 and a communications device 1 over two or more separate cables rather than through a single signal and control cable 220 . Upon connection with communications devices 1 A- 1 D as described above, interface 100 operates as described herein to enable users of communications devices 2 A- 2 D (each matching a respective one of the devices 1 A- 1 D) to communicate with each other.
FIG. 3 shows a block diagram of a VOX circuit 20 according to an embodiment of the invention. Conditioning circuit 110 receives input signal S 10 and outputs a conditioned audio signal to rectifying circuit 120 . Conditioning circuit 110 may perform signal processing operations on input signal S 10 such as gain, equalization, and filtering. In an exemplary implementation, conditioning circuit 110 provides variable gain by including an operational amplifier (op amp) configured to have variable resistive feedback. The several VOX circuits 20 may be implemented on separate circuit boards within interface 100 , or one or more of the VOX circuits 20 may be implemented on the same board.
Conditioning circuit 110 may be constructed to perform equalization operations as desired according to the output characteristics of a particular communications device. For example, a cellular or wireline telephone may provide an audio signal having a different spectral distribution than a two-way radio.
Existing VOX designs are often disfavored because of a susceptibility to false keying in response to interference such as ambient noise. It may be desirable for conditioning circuit 110 to narrow the frequency content of the signal it outputs to rectifying circuit 120 in order to enhance rejection of ambient noise by VOX circuit 20 . For example, conditioning circuit 110 may include a bandpass filter centered at approximately 125 Hz, which corresponds to a fundamental frequency (F 0 ) of the voice of a typical adult male speaker (alternatively, the frequency may be limited to a band near or including 210 Hz, the fundamental frequency of the voice of a typical adult female speaker). Depending upon the intended application, the energy content of one or more different frequency bands may be used to establish a keying event. In a case where gain and bandpass equalization or filtering is provided, it may also be desirable to divide the bandpass operation into a lowpass and a highpass operation such that the gain operation may be performed between the filtering operations.
Another feature that may help to reduce the probability of false keying is the provision of RF shielding within and around VOX circuit 20 . This shielding may comprise filtering on the input and output signal paths, on the paths to the power supply rails, and on paths between stages. Additional RF shielding may be provided in the construction of the enclosure which houses the apparatus. In this way, the sensitivity of VOX circuit 20 to a RF burst from a nearby transmitter may be significantly reduced.
Rectifying circuit 120 receives the conditioned audio signal and outputs a peak signal S 20 . In one implementation, rectifying circuit 120 includes a nonlinear device such as a PN junction device. For example, the nonlinear device may be a diode or the base-emitter or base-collector junction of a bipolar junction transistor (BJT).
Comparator 140 receives peak signal S 20 and compares it to a reference voltage Vc. In one example, the reference voltage Vc has an approximate value of Vcc/3. When the voltage of peak signal S 20 exceeds the reference voltage Vc, comparator 140 outputs a channel activation signal S 30 . It is possible but not necessary to choose a different reference voltage Vc for each VOX circuit 20 .
It may be desirable to continue channel activation signal S 30 for some period of time after the voltage of peak signal S 20 falls below the reference voltage Vc. Timing circuit 130 provides a tail delay to continue a level of peak signal S 20 . In one example, timing circuit 130 includes a capacitance to ground in parallel with a resistance. When peak signal S 20 is active, the capacitance is charged. When the conditioned audio signal becomes less active or inactive, the charged capacitance maintains a voltage level of peak signal S 20 until the resistance discharges it to ground. In a further example, the resistance is variable to provide a time constant of from less than one second to several seconds.
Priority circuit 150 receives peak signal S 20 and channel activation signal S 30 and outputs PTT command signal S 60 to the associated communications device. Priority circuit 150 is also coupled to a bidirectional priority signal S 50 . In an exemplary implementation, priority signal S 50 is common to all of the VOX circuits 20 .
Priority circuit 150 responds to an activation of either channel activation signal S 30 (by comparator 140 ) or priority signal S 50 (by another instance of priority circuit 150 ). In a case where channel activation signal S 30 becomes active, priority circuit 150 asserts priority signal S 50 and does not assert PTT command signal S 60 . As a result, other channels are prevented from being activated, and the associated channel is maintained in receive mode.
In a case where another circuit asserts priority signal S 50 , priority circuit 150 asserts PTT command signal S 60 and prevents assertion of channel activation signal S 30 . As a result, the channel is prevented from being activated and is switched into transmit mode.
FIG. 4 shows an exemplary implementation of priority circuit 150 that includes a peak suppression element 210 , a mode select element 220 , a PTT closure element 230 (all implemented in this example using FETs), and a diode 240 . This implementation also includes two resistances 250 and 260 (each resistance having a value of 100 kilohms) that may slow a response of mode select element 220 and reduce an incidence of false responses.
In a case where priority circuit 150 receives channel activation signal S 30 , mode select element 220 is turned on. The resulting path to ground in mode select element 220 prevents peak suppression element 210 from being turned on, thus preventing peak suppression element 210 from pulling peak signal S 20 to ground. The same path to ground also prevents PTT closure element 230 from being turned on, thus maintaining the associated communications device in a receive mode. Channel activation signal S 30 also causes priority signal S 50 to be asserted through diode 240 .
In a case where priority circuit 150 receives priority signal S 50 , peak suppression element 210 is turned on. The resulting path to ground in peak suppression element 210 pulls peak signal S 20 to ground, thus preventing channel activation signal S 30 from being asserted (by keeping peak signal S 20 from exceeding the reference voltage Vc and by preventing charging of the capacitance in timing circuit 130 ). Priority signal S 50 also causes PTT closure element 230 to turn on, thus pulling PTT command S 60 to ground and sending a PTT closure command to the associated communications device.
FIG. 5 shows a VOX circuit 22 according to an alternate implementation of VOX circuit 20 . VOX circuit 22 includes an initialization circuit 170 that prevents the assertion of channel activation signal S 30 during power-up of the interface 100 . For example, initialization circuit may pull peak signal S 20 below the reference voltage Vc (e.g. to ground) during power-up. In an exemplary implementation, initialization circuit 170 includes a BJT having its collector coupled to peak signal S 20 , its emitter coupled to ground, and its base coupled to a supply voltage of interface 100 through a capacitance. A transient occurring on the supply voltage during power-up causes the capacitance to conduct a voltage to the base of this BJT, creating a conductive path between the collector and emitter until the supply voltage reaches a steady state.
FIG. 6 shows a block diagram of a switching matrix 30 . Each input signal S 10 is inputted to a corresponding analog switch Sw 1 . Switch Sw 1 is closed upon assertion of channel activation (CA) signal S 30 , at which time input signal S 10 passes through resistance R 1 onto a common bus. A corresponding multiplexer M 1 also receives CA signal S 30 , and assertion of CA signal S 30 causes that multiplexer M 1 to select a null input for output signal S 16 . The other multiplexers M 1 (i.e. those receiving an unasserted CA signal S 30 ) select the input signal S 10 on the common bus for the corresponding output signals S 16 . In an exemplary implementation, switches Sw 1 and multiplexers M 1 are implemented using analog multiplexers of the 74HCT family.
FIG. 7 shows an alternate implementation 32 of a switching matrix according to an embodiment of the invention. In this implementation, a circuit Ckt 1 conditions the signal on the common bus before it passes into multiplexers M 1 . Rather than a null input as shown in FIG. 6, a nonnull input based on a reference voltage Vr is selected by the multiplexer M 1 corresponding to the asserted CA signal S 30 . The nonnull input may be produced by a circuit Ckt 2 as shown in FIG. 7 . Reference voltage Vr may be chosen to be at least one-quarter of Vcc; in one embodiment, reference voltage Vr is approximately one-half of Vcc. Use of a nonnull voltage rather than a null voltage may improve audio quality by reducing popping noise at keying events.
FIG. 8 illustrates an exemplary application of an alternate implementation 102 of an interface according to an embodiment of the invention that includes an U/O port 12 that communicates with a telephone, which may be wired (e.g. having a landline connection to the PSTN) and/or wireless (e.g. having a connection to a cellular telephone network), over a cable 220 t . In one embodiment of the invention, cable 220 t includes an acoustic coupler. FIG. 9 shows a block diagram of interface 102 . In order to compensate for a difference in audio quality (e.g. spectral content) in the signal provided by the telephone and/or the acoustic coupler, I/O port 12 may include gain and/or equalization operations in conditioning circuits 310-340 as shown in FIG. 10 . In an exemplary implementation, conditioning circuit 340 outputs an active differential (e.g. balanced) output on acoustic coupler output signal S 96 to compensate for inefficiencies in the transfer of acoustic energy to the telephone.
FIG. 11 shows a schematic diagram of an input select circuit 360 . By providing a short or an open circuit across input select terminals T 98 , cable 220 t causes circuit 360 to select input signal S 10 t from among signals S 90 c and S 92 c (corresponding to acoustic coupler input signal S 90 and wired input signal S 92 , respectively).
In a similar manner, an interface according to an embodiment of the invention may also be adapted to support communications paths to other keyed and nonkeyed devices such as 3-wire or 4-wire intercoms, tape recorders, or one-way radios. In an alternative embodiment, two or more interfaces 100 may be connected for increased capacity.
FIG. 12 shows a block diagram of a supply voltage monitor circuit 300 including two voltage level sensors 310 and 320 . Each of these sensors 310 and 320 monitors the supply voltage by indicating a relation between the supply voltage and a predetermined threshold voltage. FIG. 13 shows a block diagram of an alternate implementation 302 of a supply voltage monitor circuit, in which each sensor 310 / 320 includes a voltage divider 312 / 322 and a threshold detector 314 / 324 . In this implementation, sensor 320 is configured to have a higher threshold voltage than sensor 310 . When sensor 320 indicates the predetermined relation between the supply voltage and its higher threshold voltage, the indication signal is also inputted to suppression circuit 330 , which suppresses an indication by sensor 310 of a relation between the supply voltage and the lower threshold voltage.
An interface 100 according to an embodiment of the invention is designed to work reliably and at low power. Because the current demand of apparatus 100 is kept at a minimum, and because the communications devices 1 A- 1 D are self-powered, apparatus 100 may operate reliably on common, primary-type, DC battery cells, a vehicle cigarette-lighter jack, or another low-power source such as may be readily available on the scene (e.g. a +28 VDC aircraft power bus), with no need for an inverter, generator or landline AC supply.
In addition to the benefits mentioned above, an interface according to an embodiment of the invention may be extremely portable and inexpensive, especially in comparison to existing alternatives. Moreover, such an interface allows a user with only minimal training to deploy a system for interoperated support of multiple communication paths and leave it to operate unattended.
In a further embodiment of the invention, switching matrix 30 is configurable so that an organizational structure among the communications devices 1 A- 1 D may be incorporated. For example, communications received from members of one service group may generally be transmitted only to radios within that group, while communications received from any commander may be transmitted by all other communications devices. In a further embodiment of the invention, at least one of the cables 220 supports an additional control path so that the configuration of switching matrix 30 may be controlled at least in part by a control signal from the corresponding communications device.
In an interface according to a further embodiment of the invention, at least one of the cables 220 is replaced by a low-power RF link. For example, such a link may conform to a version of the Bluetooth specification (e.g. as approved for Part 15 radio devices operating in the 2.4 GHz ISM band or similar devices operating in another band). In a further implementation, a cable 220 carries an input signal S 10 and a corresponding output signal S 16 , while a low-power RF link as described above carries the corresponding PET command S 60 . | A voice-operated communications interface permits communications between two or more groups using incompatible communications devices such as two-way radios. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to the removal of encapsulants from the integrated circuits.
Many integrated circuits are coated with an elastomeric encapsulant to protect the circuit components against condensed moisture, particulate matter, damage during assembly, and in some cases, light. After completion of the encapsulation process, it is often found that one or more components are defective. Since many of the circuits are quite complex and expensive, it is often economically feasible to repair a defective circuit rather than discard it. Repair can only be achieved after the encapsulant has been removed from the area containing the defective component.
Removal of encapsulating materials where the cohesive strength is greater than the adhesive strength does not present a problem. The area to be removed is outlined by cutting and the coating to be removed simply gripped at one edge with a tweezer and peeled off. It was found that other encapsulating materials where the cohesive strength is less than the adhesive strength cannot be as easily removed by this method because the encapsulant breaks apart when peeling is attempted. Furthermore, attempts to pry or lift the latter encapsulants often resulted in destruction or damage of many of the circuit components.
It is therefore a primary objective of this invention to provide a means that would enable non-peelable elastomeric encapsulants to be peeled from integrated circuits without damaging sensitive circuit components.
SUMMARY OF THE INVENTION
This and other objects are achieved in accordance with the invention by using low temperatures to temporarily modify the material properties of the encapsulant. The region of coating to be removed is defined by cutting through the encapsulant, and the region is cooled and peeled from the circuit. Cutting may be done either before or during cooling. In one embodiment of the invention, the outlined encapsulant is cooled with chilled nitrogen gas in the temperature range of -60 to -90° C. The process allows an effective, convenient and reproducible method to remove elastomeric encapsulants that do not peel easily at room temperature from integrated circuits without permanently altering the circuit.
The foregoing will be more apparent from the following more particular description of the preferred embodiment of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a perspective view of a portion of a typical hybrid integrated circuit;
FIG. 2 is a cross-sectional view of a portion of the circuit of FIG. 1 at one stage of the process in accordance with one embodiment of the invention; and
FIG. 3 is a cross-sectional view of the same circuit during another stage of the process in accordance with the same embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a portion of a hybrid integrated circuit which may utilize the present invention. As shown in FIG. 1, the circuit comprises an insulating substrate 1 with integrated circuit chips, 2, and associated conductors 8 bonded thereto. A cured encapsulant layer, 3, is deposited over the substrate 1 and chip 2. For the purposes of illustration, only three chips are shown on the substrate in FIG. 1 but it should be clear that a greater number of chips are usually formed on a typical integrated circuit along with further components such as resistors and capacitors.
As shown in FIG. 2, in accordance with one embodiment of the present method, the region of encapsulant to be removed, 4, was outlined by cutting with a suitable non-metallic tool (not shown), such as a sharpened plexiglass rod. The encapsulant is typically an elastomeric (rubber) resin, made from a silicone, a silicone-organic copolymer, or a silicone-organic polymer blend, each containing siloxane bonds (Si-O-Si) as a major constituent. An example is a silicon rubber comprising a methoxy terminated dimethyl siloxane polymer and sold by Dow Corning Co. under the designation Q3-6550 RTV (room temperature vulcanizing), but the invention may be used with a number of encapsulants known in the art.
For easy removal of the encapsulant, it should be cooled such that its cohesive strength becomes greater than its adhesive strength. In accordance with the main feature of the invention, the area of encapsulant 4 to be removed was cooled to allow it to be peeled from the circuit. This may be achieved by cooling the entire circuit and encapsulant 3 or by the use of localized cooling of the portion of encapsulant 4 to be removed.
A particular method of cooling is shown in FIG. 3. A flow of chilled nitrogen gas 5 was projected from a nozzle 6 at an angle of 30° to 45° to the plane of the substrate 1. This range of angles facilitates peeling, although an angle from 0° to 90° is sufficient to allow the encapsulant to be readily peeled from the circuit. In this embdiment, using Dow Corning Q3-6550 RTV as an encapsulating material, the temperature range of -60 to -90° C was used. It was discovered that the tear strength of the RTV increased dramatically upon cooling from room temperature to below -60° C, as the encapsulant developed crystalline regions, thus increasing its peel capability. Whether this is the only reason for the development of peel capability is not presently known. The temperature range at which an encapsulant becomes peelable, as well as its precise causes, may vary with different materials, since physical and thermal characteristics of elastomers depend on polymer type and the types and amounts of added fillers and other constituents.
The encapsulant 4 was then gripped at one end with tweezer 7 and peeled from the substrate 1 as illustrated in FIG. 3. As the peeling progressed, the flow of chilled gas 5 was continuously aimed at the encapsulant-substrate interface and also at the peeled encapsulant where the peel force was being applied to insure sufficient cooling and maintain the increased tear strength.
The chilled nitrogen gas was obtained by flowing the gas through 1/4 inch diameter coiled copper tubing submerged in a Dewar of liquid nitrogen in accordance with known techniques. A flow rate of 12-18 liters/minute was used, with the nozzle a distance of 1 - 11/2 inches from the circuit. The temperature of the nitrogen gas at the encapsulant surface is easily controlled by the rate of flow of nitrogen through the coil and the distance of the nozzle from the circuit. Increasing the flow rate or decreasing the distance between nozzle and circuit will further cool the circuit, a well known technique to those skilled in the art.
Although the preferred embodiment of the invention has been described in detail, it is to be understood that various changes, substitutions and alterations can be made without departing from the spirit and scope of the invention. | A technique is disclosed for the mechanical removal of elastomeric encapsulants from integrated circuits. The encapsulant to be removed is outlined by cutting, and the outlined area is cooled sufficiently either during or subsequent to cutting such that the encapsulant may be removed by gripping one edge with tweezers and peeling from the circuit. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional patent application of U.S. patent application Ser. No. 11/749,587, filed May 16, 2007 (now U.S. Pat. No. 7,780,375), which claimed priority of U.S. Provisional Patent Application Ser. No. 60/824,005, filed Aug. 30, 2006, both of which are hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to marine platforms such as oil and gas well drilling platforms. More particularly, the present invention relates to an improved method and apparatus for elevating the deck area of a fixed marine platform to better protect equipment that is located on the deck area from storms (e.g. hurricanes) that generate heightened wave action.
2. General Background of the Invention
There are many fixed platforms located in the oil and gas well drilling areas off the United States coast such as in the Gulf of Mexico. Such marine platforms typically employ an undersea support structure that is commonly referred to as a jacket. These jackets can be many hundreds of feet tall, being sized to extend between the seabed and the water surface area. Jackets are typically constructed of a truss like network of typically cylindrically shaped pipe, conduit or tubing that is welded together. The jackets can be secured to the seabed using pilings that are driven into the seabed. The jacket is then secured to the piling. The part of the offshore marine platform that extends above the jacket and above the water surface is typically manufactured on shore and placed upon the jacket using known lifting equipment such as a derrick barge. This upper portion is the working part of the platform that is inhabited by workers.
Marine platforms can be used to perform any number of functions that are associated typically with the oil and gas well drilling and production industry. Such platforms can be used to drill for oil and gas. Such platforms can also be used to produce wells that have been drilled. These fixed platforms typically provide a deck area that can be crowded with extensive equipment that is used for the drilling and/or production of oil and gas.
When storms strike the Gulf of Mexico and other areas, offshore marine platforms are put at risk. While the jacket and platform are typically designed to resist hurricane force wind and wave action, equipment located on the deck of the marine platform can easily be damaged if hurricane generated wave action reaches the deck area.
An additional consequence of wave action reaching the platform deck is catastrophic platform collapse, which happened in several instances during recent storms in the United States Gulf of Mexico.
BRIEF SUMMARY OF THE INVENTION
The present invention solves these prior art problems and shortcomings by providing a method and apparatus for elevating the deck area of an existing marine platform so that equipment that occupies the deck can be further distanced from the water surface. The method of the present invention this provides more clearance, more freeboard and more protection to deck area equipment during severe storms such as hurricanes.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIG. 1 is a schematic, elevation view of a fixed marine platform;
FIG. 2 is a perspective view illustrating a method step of the present invention;
FIG. 3 is a perspective view illustrating a method step of the present invention;
FIG. 4 is a perspective view illustrating a method step of the present invention, placement of the upper and lower bushing sleeves;
FIG. 5 is a partial perspective view of a preferred embodiment of the apparatus of the present invention illustrating placement of the upper and lower bushing sleeves;
FIG. 6 is a partial perspective view of a preferred embodiment of the apparatus of the present invention illustrating a method step of the present invention;
FIG. 7 is a partial perspective view of a preferred embodiment of the apparatus of the present invention illustrating one of the extension sleeve guides;
FIG. 8 is a sectional view taken along lines 8 - 8 of FIG. 7 ;
FIG. 9 is a partial elevation view of a preferred embodiment of the apparatus of the present invention illustrating placement of the extension sleeve guides;
FIG. 10 is a partial elevation view of a preferred embodiment of the apparatus of the present invention showing positions of the leg cuts;
FIG. 11 is a partial perspective exploded view of a preferred embodiment of the apparatus of the present invention;
FIG. 12 is a partial perspective view of a preferred embodiment of the apparatus of the present invention illustrating the method of the present invention, placement of the upper ring;
FIG. 13 is a partial elevation view of a preferred embodiment of the apparatus of the present invention illustrating placement of the upper ring;
FIG. 14 is a partial perspective exploded view of a preferred embodiment of the apparatus of the present invention illustrating placement of the hydraulic pistons;
FIG. 15 is a partial perspective view of a preferred embodiment of the apparatus of the present invention illustrating placement of the hydraulic pistons;
FIG. 16 is a fragmentary elevation view illustrating the method of the present invention, namely the step of completing the leg cuts;
FIG. 17 is a fragmentary perspective of a preferred embodiment of the apparatus of the present invention illustrating extension of the leg with the hydraulics pistons;
FIG. 18 is a partial perspective view of the method and apparatus of the present invention, showing the method step of closing the sleeve openings; and
FIG. 19 is an elevation view of a preferred embodiment of the apparatus of the present invention illustrating the marine platform after its deck area has been elevated using the method and apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a marine platform deck elevating system 10 that is shown generally in FIGS. 14-15 and 17 and in method steps that are illustrated in FIGS. 2-18 .
In FIG. 1 , a fixed marine platform 11 is shown having a deck 16 that is positioned at an elevation 18 that is elevated above the water surface 12 a distance H 1 that is indicated by the numeral 19 in FIG. 1 . The numeral 19 and the dimension line H 1 represent the existing clearance above water. It is necessary to protect equipment that is contained on the deck 16 from storm generated wave action. In the Gulf of Mexico, hurricanes can generate a storm surge and wave action that puts equipment and/or personnel located on deck 16 at peril. If a deck is not located at a safe elevation, it must be elevated. FIG. 1 illustrates a typical fixed platform 11 having a plurality of legs 14 that support the deck 16 . Diagonal braces 17 can extend between legs 14 and deck 16 as shown in FIG. 1 . The platform 11 can include other structure such as for example horizontal beams or members and/or additional vertical or diagonal members.
Legs 14 can be of a constant diameter or can include tapered sections 13 , wherein the diameter of the upper leg section 15 A is less than the diameter of the lower leg section 15 B. Leg 14 can thus include a number of different leg sections such as a lower, larger diameter leg section 15 B, a tapered leg section 13 , and an upper, smaller diameter leg section 15 A that is positioned above the tapered section 13 . The method and apparatus of the present invention can be used to elevate the deck 16 to a new elevation 20 (see FIG. 19 ) that is higher than the previous, existing deck elevation 18 of FIG. 1 . The method and apparatus of the present invention thus provides a new clearance 21 above water surface 12 (also shown by the arrow H 2 in FIG. 19 ).
FIGS. 2 and 3 illustrate an initial method step of the present invention, namely the placement of lower bushing sleeve 24 . The lower bushing sleeve 24 can be comprised of a pair of half sleeve sections 22 , 23 as shown in FIGS. 2-3 . The sections 22 , 23 can be joined with welds 26 as shown in FIGS. 3-4 . Arrows 25 in FIG. 2 schematically illustrate the placement of sleeve sections 22 , 23 upon leg 14 at a position below tapered section 13 as shown.
In FIGS. 4-6 , upper bushing sleeve 29 can also be comprised of a pair of sleeve half sections. The sleeve sections 27 , 28 each provide an opening 35 or 36 that is receptive of a pin 50 as will be explained more fully hereinafter. Weld ring sections 30 , 31 can be used to attach the sleeve sections 27 , 28 to tapered section 13 . As with the lower bushing sleeve 24 , one or more welds 37 can be used to join the sleeve sections 27 , 28 to each other. Arrows 33 in FIG. 4 illustrate the placement of sleeve sections 27 , 28 upon tapered section 13 . Arrows 34 in FIG. 4 illustrate the attachment of weld ring 32 to the assembly of sleeve sections 27 , 28 and to tapered section 13 .
In FIGS. 6-9 and 11 , a plurality of extension sleeve guides 38 are shown. These extension sleeve guides 38 are attached to the platform 11 leg 14 at a position that is above upper bushing sleeve 29 . The extension sleeve guides 38 can extend from tapered section 13 to smaller diameter leg section 15 A as shown in FIGS. 6 and 9 . Arrows 39 illustrate placement of extension sleeve guides 38 to leg 14 . Each extension sleeve 38 can be comprised of flanges 40 and webs 41 . The web 41 actually contacts the leg 14 and can be shaped to conform to the shapes of tapered section 13 and smaller diameter leg section 15 A as shown in FIGS. 7 and 9 (see DIM “A”, FIG. 7 ).
In FIGS. 10-15 , an extension sleeve 44 can be comprised of a pair of extension sleeve sections 45 , 46 . Each extension sleeve section 45 , 46 has slots 47 , 48 that can be used to complete a cut through the leg 14 after the sleeve sections 45 , 46 have been attached to leg 14 and guides 38 .
Before attachment of the sleeve sections 45 , 46 four cuts are made through leg 14 as shown in FIG. 10 . The cuts 42 , 43 do not extend 360 degrees around the leg 14 , but rather extend only a partial distance as shown in FIG. 10 . Though partial cuts 42 , 43 are made, enough of the leg 14 remains to structurally support the platform 11 and its deck 16 considering the use of sleeve 44 and the method of the present invention disclosed herein.
After the sleeve sections 45 , 46 have been installed, a cut can be made to encircle the leg 14 thus severing it in two parts. In order to complete the cut, slots are provided in the sleeve sections 45 , 46 . In FIG. 11 , the sleeve section 45 has slot 47 . In FIG. 11 , the sleeve section 46 has slot 48 .
After installing the upper bushing sleeve 29 , circular cut openings 49 are made through the leg 14 at the openings 35 , 36 in the sleeve sections 27 , 28 . These cut openings 49 enable pin 50 to be placed through the openings 67 , 68 in sleeve sections 45 , 46 respectively as well as through the openings 49 in upper bushing sleeve 29 . Pin 50 prevents uplift from damaging the platform 11 should a storm produce excess wave action before the method of the present invention can be completed.
Each of the sleeve sections 45 , 46 provides lugs to which hydraulic pistons can be attached. Sleeve section 45 provides a plurality of lugs 51 . Sleeve section 46 provides a plurality of lugs 52 . Each of the lugs provides an opening for enabling a pinned connection to be made between the lugs 51 , 52 and the hydraulic pistons 64 . Lugs 51 provide openings 53 . Lugs 52 provide openings 54 . In a preferred method and apparatus, four pairs of lugs 51 , 52 are thus provided to the extension sleeve 44 . Each pair of lugs 51 , 52 can be spaced circumferentially about sleeve 44 , about 90 degrees apart.
A ring 55 is positioned above extension sleeve 44 as shown in FIGS. 12-15 and 17 - 19 . Ring 55 is used to form a connection between the leg 14 and the hydraulic piston 64 . Ring 55 can be formed of a pair of ring sections 56 , 57 that are attached to the smaller diameter leg section 15 A as shown in FIGS. 12 and 13 . Each of the ring sections 56 , 57 provides a plurality of lugs 58 , 59 . The ring section 56 has lugs 58 . The ring section 57 has lugs 59 . Each lug 58 , 59 has a lug opening 60 that enables a pinned connection to be made between a lug 58 or 59 and a piston 64 . Each ring section 56 , 57 can be formed of arcuate generally horizontal plate sections and vertical plate sections. Each of the ring sections 56 , 57 thus provide an upper arcuate plate section 61 and a lower arcuate plate section 62 . Vertical plate sections 63 span between the upper and lower arcuate plate sections 61 , 62 .
Hydraulic pistons 64 are provided for elevating that portion of the leg 14 that is above the cuts that are made through the leg 14 (see FIGS. 10 and 16 ). Preferably three (3) or four (4) pistons can be used, but as few as two (2) rams can be used or more, such as many as eight (8) could be used for example.
Each hydraulic piston 64 can be comprised of a cylinder 65 and an extensible push rod 66 . Each end portion of hydraulic piston 64 provides an opening 69 on cylinder 65 that enables a pinned connection to be formed between each end of hydraulic piston 64 and lugs 51 , 52 or 58 , 59 . The upper end portion of each hydraulic piston 64 attaches with a pinned connection to a lug 58 or 59 that is a part of ring 55 . The lower end portion of each hydraulic piston 64 forms a pinned connection with the lugs 51 , 52 of extension sleeve 44 as shown in FIGS. 14-15 . Arrows 74 in FIG. 14 illustrate assembly of pistons 64 to lugs 51 , 52 , 58 , 59 .
Once the hydraulic pistons 64 have been installed to the position shown in FIG. 15 , a cut can be completed for severing leg 14 . This can be seen in more detail in FIGS. 10 , 15 - 16 wherein the previously formed cuts 42 , 43 are shown. Notice that uncut portions 70 (DIM “B”, FIG. 16 ) of leg 14 align with the slots 47 or 48 of sleeve sections 45 , 46 . The leg 14 can thus be cut 360 degrees by cutting the previously uncut section 70 at slot 47 or 48 , indicated by phantom lines as cut 73 in FIG. 16 . The three hundred sixty degree cut ( 42 , 43 , 73 ) is made after the extension sleeve 14 , hydraulic pistons 64 and ring 55 form a structural support of the leg 14 above and below the cuts 42 , 43 . In order to then elevate the smaller diameter leg section 15 A relative to the larger diameter leg section 15 B below tapered section 13 , each hydraulic piston 64 can be activated as illustrated by arrows 72 in FIG. 17 .
Once elevated, the various openings and slots in sleeve 44 can be covered for corrosion protection using a plurality of curved cover plate sections 71 . To complete the repair, the sleeves 44 can be welded to the leg 14 and using shims as necessary between sleeve 44 and leg 14 , tapered section 13 or sections 15 A, 15 B. While the method disclosed herein contemplates that the elevation process would preferably take place as one jacking operation. The invention should not be so restricted. The method of the present invention contemplates a method wherein the jacking process could be subdivided into several smaller (or shorter) jacking elevations. The legs 14 would be pinned off at an intermediate point and the jacks moved to a second set of lugs. Arrow 75 in FIG. 17 shows the distance that the upper leg section 15 A is elevated.
The following is a list of parts and materials suitable for use in the present invention.
PARTS LIST
Part Number
Description
10
marine platform deck elevating system
11
platform
12
water surface
13
tapered section
14
leg
15A
smaller diameter leg section
15B
larger diameter leg section
16
deck
17
diagonal brace
18
existing deck elevation
19
existing clearance above water
20
new deck elevation
21
new clearance above water
22
sleeve section
23
sleeve section
24
lower bushing sleeve
25
arrow
26
weld
27
sleeve section
28
sleeve section
29
upper bushing sleeve
30
weld ring section
31
weld ring section
32
weld ring
33
arrow
34
arrow
35
opening
36
opening
37
weld
38
extension sleeve guide
39
arrow
40
flange
41
web
42
cut
43
cut
44
extension sleeve
45
extension sleeve section
46
extension sleeve section
47
slot
48
slot
49
drilled opening
50
support pin
51
lug
52
lug
53
opening
54
opening
55
ring
56
ring section
57
ring section
58
lug
59
lug
60
lug opening
61
upper arcuate plate section
62
lower arcuate plate section
63
vertical plate section
64
hydraulic piston
65
cylinder
66
pushrod
67
opening
68
opening
69
opening
70
uncut portion
71
cover plate
72
arrows
73
cut
74
arrow
75
arrow
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | A method of elevating the deck area of a marine platform (e.g. oil and gas well drilling or production platform) utilizes a specially configured sleeve support to support the platform legs so that they can be cut. Once cut, jacks elevate the platform above the cuts. The sleeve support is then connected (e.g. welded) to the platform leg and becomes part of the structural support for the platform. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is for entry into the U.S. national phase under §371 for International Application No. PCT/IB02/004630 having an international filing date of Nov. 5, 2002, and from which priority is claimed under all applicable sections of Title 35 of the United States Code including, but not limited to, Sections 120, 363 and 365(c).
FIELD OF THE INVENTION
The invention relates to a mobile electronic system comprising means which realize the function of a compass and to components of such a system. The invention relates equally to a method for a mobile electronic system.
BACKGROUND OF THE INVENTION
It is known from the state of the art to provide mobile electronic systems with a two dimensional compass. Such a mobile electronic system may be included for instance in a communication device like a mobile phone.
In German patent application DE 198 37 568 A1, it is proposed to provide a Personal Digital Assistant (PDA) with a Global Positioning System (GPS) receiver, a mobile communication unit and a compass. The compass is used for determining the current orientation of the PDA, which is required for realizing navigation functions in the PDA.
In British patent application GB 2 298 539 A, it is equally proposed to provide a hand held device containing a GPS receiver with a compass. A displayed information relating to the current environment, e.g. a map, is rotated in accordance with the respective orientation of the device.
Further, it is proposed in international application WO 01/88687 A2 to access context information with a user equipment, e.g. a mobile phone. The context information is downloaded from a network based on a location service. Then, the orientation of the user equipment is determined using a compass in the user equipment. Once the orientation is known, a visual user interface is generated at the user equipment for displaying the downloaded context information. In order to select a virtual object displayed in the visual user interface, the user can point to the respective object by orienting the user equipment. During the movement of the user equipment, the displayed virtual objects move accordingly in front of the user.
A mobile electronic system may also comprise an Inertial Navigation Systems (INS), which INS can be used for determining the position of the mobile electronic system. In such a system, it is essential that provided heading information remains accurate along time, since even small errors in the computed orientation cause significant errors to the position estimate. Traditionally, IN Systems utilize gyro-compasses to ensure an accurate heading. Gyro-compasses, however, have several disadvantages. They constitute quite expensive components due to their complicated electronics. Moreover, they are physically large sensors and can thus not be implemented in small modules. The use of a conventional 3-axis gyro-compass in a small INS is not feasible at all, since it requires even more complex electronics and its power consumption is much higher. As a result, it is more expensive and it also requires more space. A 3-axis operation, however, is essential for an accurate INS.
SUMMARY OF THE INVENTION
It is an object of the invention to expand and enhance the usability of a mobile electronic system.
This object is reached according to the invention with a mobile electronic system, which comprises output means enabling a presentation of information to a user of the mobile electronic system. The proposed mobile electronic system further comprises a 3D (three-dimensional) magnetometer performing magnetic measurements in three dimensions and providing data indicative of the current posture of the mobile electronic system based on these measurements. The 3D magnetometer thus realizes the functions of a 3-dimensional compass. Finally, the proposed mobile electronic system comprises processing means processing the data provided by the 3D magnetometer for enabling a posture related presentation of information via the output means.
The mobile electronic system may be a single unit or be composed of several units. It may be comprised, for example, completely in a user equipment like a mobile communication device. Alternatively, the mobile electronic system may comprise for example a user equipment including the output means, while at least the 3D magnetometer is included in a separate, complementary unit which can be connected to the user equipment. In the latter case, the connection should be rigid so that the posture of the complementary unit with the 3D magnetometer corresponds always to the posture of the user equipment. The processing means can then be included in either of the two units or be distributed to the two units. The unit comprising the output means may be for example a mobile phone and the complementary unit comprising the 3D magnetometer a functional cover for the mobile phone.
The object of the invention is equally reached with a corresponding complementary unit and with a corresponding user equipment comprising either the part of the proposed mobile electronic system not comprised by a complementary unit or the entire proposed mobile electronic system.
The object of the invention is further reached with a corresponding method for a mobile electronic system. The method comprises in a first step performing magnetic measurements in three dimensions in the mobile electronic system. The method comprises moreover determining data indicative of the current posture of the mobile electronic system based on the performed magnetic measurements. Finally, the proposed method comprises processing this data for enabling a posture related presentation of information to a user of the mobile electronic system.
The invention is based on the consideration that a 3D magnetometer is able to sense not only the orientation of a device in which it is included or to which it is attached in a horizontal plane, like a 2D compass, but also its current inclination. This additional data can be employed for a variety of new or enhanced functions of a mobile electronic system. It can be used for example to enhance the presentation of information and/or to select a mode of presentation depending on the current posture of the mobile electronic device. A 3D magnetometer can further be used as main source for heading information in an inertial navigation system, since it is smaller and less expensive than a gyro-compass.
Preferred embodiments of the invention become apparent from the dependent claims.
In a preferred embodiment of the invention, the presented information comprises compass information.
In another preferred embodiment of the invention, different modes of presentation are selected depending on the posture of the mobile electronic system. In case the output means comprise a display and the mobile electronic system is held basically horizontally, the display and functioning can resemble e.g. to a traditional compass. When the mobile electronic system is held basically vertically, in contrast, the presentation of information may be switched to some other mode.
In another preferred embodiment of the invention, the output means comprise a 3D display for a presentation of compass information, e.g. a presentation of a floating compass. This enables a new user experience compared to a 2D electrical compass, which cannot even be used in free posture.
In another preferred embodiment of the invention, the system comprises additional sensor means, which provide further measurement data. These further measurement data can be employed by the processing means in addition for enabling the posture related presentation of information via the output means. The additional measurement data allow the processing means to adjust the functionality of the system to the environment and/or to a user profile. For example, data on the posture and the characteristics of the movements of the mobile electronic system can be used to change the functionality. The adjustment of the functionality may comprise for example an adjustment of the presentation of information via the output means and/or an adjustment of a filtering of signals provided by the 3D magnetometer.
The additional sensor means may comprise for example a 2D or 3D linear accelerometer measuring the acceleration of the mobile electronic system in two or three dimensions, respectively, or a 3D angular accelerometer measuring the angular acceleration of the mobile electronic system in three dimensions.
Since a magnetic compass is subjected to unpredictable disturbances, a 3D angular accelerometer can be used to verify whether sudden changes of direction indicated by the 3D magnetometer actually occurred or whether there was only a temporary disruption. This enables a compensation of random magnetic disturbances. From an implementation point of view, angular accelerometers have the advantage that they do not require any dedicated electronics and that they can be read with the same electronics as linear accelerometers. Angular accelerometers are also inexpensive and smaller than gyro-compasses.
In case a 3D angular accelerometer is used as additional sensor means, the 3D magnetometer may provide first data indicating a current heading of the mobile electronic system, while the 3D angular accelerometer provides second data indicating a current heading of the mobile electronic system. Moreover, the processing means may comprise a complementary filter combining the first and second data, in order to obtain a particularly reliable information on the current heading of the mobile electronic system.
A combination of a 3D magnetometer and a 3D angular accelerometer is of particular advantage for an INS realized in the mobile electronic system.
It is understood that data provided by the 3D magnetometer may be used for various applications in the mobile electronic system.
BRIEF DESCRIPTION OF THE FIGURES
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings, wherein:
FIG. 1 schematically illustrates a first posture dependent display mode employed in a first embodiment of the invention;
FIG. 2 schematically illustrate a second posture dependent display mode employed as first example in the first embodiment of the invention;
FIG. 3 schematically illustrate a second posture dependent display mode employed as second example in the first embodiment of the invention;
FIG. 4 a - d schematically illustrate a simulation of a floating compass in a second embodiment of the invention;
FIG. 5 is a block diagram of a complementary filter employed in a third embodiment of the invention; and
FIG. 6 is a block diagram of a complementary filter in one compass plane that is based on two axis of a magnetometer and on an angular accelerometer.
DETAILED DESCRIPTION OF THE INVENTION
In a first embodiment of the invention illustrated in FIGS. 1 to 3 , a mobile phone 10 can be employed as a two-dimensional compass with two different presentation modes. The mobile phone 10 comprises buttons 11 , a display 12 , a 3D magnetometer, a 3D accelerometer and processing means.
The 3D magnetometer constantly performs magnetic measurements in all three dimensions. The measurement results, which constitute an information on the current posture of the mobile phone 10 , are provided to the processing means. Moreover, the 3D accelerometer constantly performs acceleration measurements in all three dimensions. Also these measurement results, which allow one to draw conclusions as to the current velocity of the mobile phone, are provided to the processing means.
As long as the measurement results by the 3D accelerometer indicate that the mobile phone is only moved slowly, a fast acting filtering software is activated in the processing means for filtering the measurement results provided by the 3D magnetometer. The fast acting filtering software filters the measurement results with an integration period of about 1 to 3 seconds, which removes e.g. the influence of hand vibrations, of by-passing cars and of disturbances in the magnetic fields of the earth.
In case the measurement results by the 3D accelerometer indicate, in contrast, that the mobile phone is moved with an increased velocity, a slow filtering software is activated in the processing means for filtering the measurement results provided by the 3D magnetometer. The slow filtering software filters the measurement results with an integration period of about 5 to 10 seconds. The slow filtering is activated for instance in case the compass function is to be used while the user is driving in an urban city environment, in order to filter temporary fluctuations in the magnetic field due to bypassing trams, buses, buildings, metal constructions, etc.
The filtered measurement results of the 3D magnetometer are then evaluated by the processing means for presenting compass information on the display 12 of the mobile phone 10 .
When the magnetic measurements indicate that the phone 10 is positioned basically horizontally, which may e.g. be the case when a user of the phone 10 is walking, a first mode of presentation is selected by the processing means. In the first mode of presentation, the display 12 and the functioning resembles a traditional compass.
For this first mode of presentation, the processing means determine the direction in the horizontal plane to which the top of the mobile phone 10 is oriented based on the provided measurement results. The orientation information contained in the filtered signal is then reflected by an arrow 13 in a circle 14 on the display 12 of the mobile phone 10 , as shown in FIG. 1 . The circle 14 with the arrow 13 represent a conventional compass. Accordingly, the arrow 13 is always oriented such that it points to the North. Alternatively, any other predetermined direction could be indicated based on the filtered signals. The fast acting filtering, which is activated when the user is walking, allows the user to find North without unnecessary delays.
When the magnetic measurements indicate, in contrast, that the degree of an inclination of the mobile phone exceeds a predetermined value, which may e.g. be the case when a person is tilting the phone or when it is kept in a car stand, a second mode of presentation is selected.
For the second mode of presentation, the processing means determine the orientation of the back of the tilted mobile phone based on the filtered magnetic measurement results. The presentation of the determined compass information differs moreover from the presentation in the first mode of presentation, since a simulation of a conventional compass as in the first mode of presentation is not appropriate with a tilted phone.
Two possibilities for the second mode of presentation are illustrated in FIGS. 2 and 3 .
In the first possibility illustrated in FIG. 2 , the presentation on the display 12 resembles a “marine compass”. In a first row, the current orientation of the phone is indicated by the points of the compass North “N”, East “E”, South “S” and West “W”, while in a second row, the current orientation of the phone is indicated by corresponding degrees “90”, “180”, “270” and “360”. In the situation depicted in FIG. 2 , the user of the phone faces North-West or 315°, since the center of the first row lies between an indicated “N” and an indicated “W”, and the center of the second row lies between indicated “360” and “270” degrees.
The second possibility for the second mode of presentation illustrated in FIG. 3 is provided in order to enable a user of a mobile phone 10 to easily keep a preset target direction. The direction may be entered via the buttons 11 of the mobile phone 10 . The desired direction can be selected in particular using the points of the compass or a corresponding indication in degrees.
The direction information contained in the filtered magnetic measurement results is then reflected by a simple arrow pointing in the desired direction on the display.
FIG. 3 presents the view of a driver of a car who is using the mobile phone 10 with the second possibility for the second mode of presentation. The mobile phone 10 is fixed in a car stand, which is connected to the dashboard on the right hand side of the steering wheel of the car. In the presented example, the arrow 15 shown on the display 12 of the mobile phone 10 indicates that the desired direction is straight ahead.
With the second possibility for the second mode of presentation, thus a simplified navigation system is provided. It may be used for example when driving in an urban environment towards an airport, which is lying in a known direction. The slow filtering, which is activated when the user is driving, ensures that most magnetic disturbances are not visible in the presentation of the compass information.
In a second embodiment of the invention, a mobile phone can be employed for simulating a floating three-dimensional compass, e.g. a floating navy compass. Like the mobile phone of the first embodiment, the mobile phone of the second embodiment comprises buttons, a display, a 3D magnetometer, a 3D accelerometer and processing means. In the second embodiment, however, the display is a 3D display.
The 3D magnetometer constantly performs magnetic measurements in all three dimensions, which provide an information on the current posture of the mobile phone. The 3D accelerometer further measures the accelerations of the mobile phone in all three dimensions.
The measurement results of the 3D magnetometer and the 3D accelerometer are used by the processing means for presenting the floating compass on the display of the mobile phone. More specifically, the measurement results provided by the 3D accelerometer are used by the processing means for filtering the measurement results provided by the 3D magnetometer with a delay, similarly as described for the first embodiment. Then, the processing means show a 3D compass on the 3D display, of which the orientation corresponds to the posture information contained in the filtered measurement results. The compass is represented by the processing means on the 3D display such that a user can view the compass from all sides by tilting the mobile phone. Due to the filtering of the signals, the displayed compass follows changes of the posture only slowly, resulting in the particular effect of a virtual floating compass.
FIGS. 4 a - 4 d schematically illustrate the presentation of the floating compass on the display 42 of the mobile phone for various postures of the phone.
The compass is represented as a sphere 43 on the 3D display 42 of the mobile phone. The top of the sphere 43 , and thus of the virtual compass, is indicated by circles 44 . In all four cases illustrated in FIGS. 4 a - 4 d , the user of the mobile phone is facing South-East (SE). An arrow 45 indicating the direction which the user faces is thus labeled “SE”. The arrow 45 is always pointing to the top 44 of the sphere 43 . A circle 46 is depicted around the middle of the sphere 43 , all points of the circle being equidistant to the top 44 of the sphere 43 .
FIG. 4 a shows the display 42 in a first situation, in which the mobile phone is hold vertically. The top 44 of the compass is depicted next to the top 47 of the display 42 . The arrow 45 indicating South-East is rather short in the first situation.
FIG. 4 b shows the display 42 in a second situation in which, proceeding from the first situation in FIG. 4 a , the mobile phone is tilted sideways to the right. The user has exactly the same view on the represented compass as in FIG. 4 a . That is, the top 44 of the compass is now depicted next to the upper left corner 48 of the display 42 . The arrow 45 indicating South-East has the same length as in FIG. 4 a.
FIG. 4 c shows the display 42 in a third situation, in which, proceeding from the first situation in FIG. 4 a , the mobile phone is tilted forward. As a result, the bottom of the mobile phone is now somewhat closer to the user than the top of the mobile phone. The represented compass appears to be rotated towards the user, since the top 44 of the compass is shifted in direction of the center of the display 42 . The arrow 45 indicating South-East is slightly longer than in FIGS. 4 a and 4 b.
FIG. 4 d shows the display 42 in a fourth situation, in which the mobile phone is hold horizontally. The user of the mobile phone has now a top view on the represented compass. Thus, the top 44 of the compass is depicted in the center of the visible part of the sphere 43 . The arrow 45 indicating South-East extends throughout the visible part of the sphere 43 . The visible part of the sphere 43 is now limited by the circle 46 depicted around the middle of the sphere 43 .
The second embodiment of the invention is ideal for mobile phones having a large color display.
In a third embodiment of the invention, a mobile phone is employed for realizing an INS. To this end, the mobile phone comprises a display, a 3D magnetometer, a 3-axis angular accelerometer and processing means.
Measurement results provided by the 3D magnetometer and the angular accelerometer are used by the processing means for presenting the current heading of the user of the mobile phone on the display. The 3D magnetometer provides an excellent long term reference for the angular position of the device. However, magnetometers are sensitive to external disturbances. The angular accelerometer on the contrary presents low noise operation but poor stability. Thus, the combination of the magnetometer and the angular accelerometer provides means to perform a measurement with good stability and good tolerance to external disturbances.
FIG. 5 is a block diagram which illustrates the processing of the signals provided by the 3D magnetometer and the angular accelerometer. The block diagram comprises a first block 50 representing the 3-axis angular accelerometer and a second block 51 representing the 3D magnetometer. The output of the angular accelerometer 50 is connected to first filter means 52 and the output of the 3D magnetometer 51 is connected to second filter means 53 . The outputs of the filter means 52 , 53 are connected to a summing point 54 . The filter means 52 , 53 and the summing point 54 , which form a complementary filter, are part of the processing means of the mobile phone.
The angular accelerometer 50 measures angular accelerations of the mobile phone in any direction proceeding from a point of time at which the heading was known until a new point of time t. Based on the measured movements and on the last known heading, the angular accelerometer then estimates the new heading at point of time t and provides a corresponding first heading signal. This first heading signal comprises the true heading s(t) at point of time t and a noise component n 1 (t), which takes account of errors in the angular measurements.
At the same point of time t, the 3D magnetometer 51 performs in addition magnetic measurements, in order to determine the current posture of the mobile phone. Based on the magnetic measurements, the 3D magnetometer 51 then estimates as well the new heading of the mobile phone at point of time t and provides a corresponding second heading signal. This second heading signal comprises equally the true heading s(t) at point of time t and a noise component n 2 (t), which takes account of errors in the magnetic measurements.
As a result, two redundant measurements of the same signal are available. These two measurements can now be combined in a way that the measurement error is minimized. This is achieved with the complementary filter, to which the two heading signals are provided.
The first heading signal is subjected by the first filter means 52 to a filtering function which has a transfer function G(s). Moreover, the result of the function G(s) is subtracted from 1. The second heading signal is only subjected by the second filter means 53 to a filtering with a transfer function G(s). The output of the filter means 52 , 53 is then summed at the summing point 54 , resulting in the sum x(t). Such a complementary filtering allows to filter the noise without distorting the signal.
The signal output by the summing point 54 thus reflects very closely the true heading of the mobile phone at point of time t, and a corresponding information can be presented on the display of the mobile phone.
FIG. 6 presents a more concrete implementation of a complementary filtering based on the use of an angular accelerometer for compensating magnetic field disturbances in the signals of a magnetometer. FIG. 6 is more specifically a block diagram of a complementary filter for one compass plane that is based on a two axis magnetometer and an angular accelerometer. A similar implementation is required for all three directions.
The block diagram of FIG. 6 comprises two blocks 61 , 62 representing measurement values m x , m y of a 3D magnetometer in a first direction x and a second direction y, respectively. The two blocks 61 , 62 are connected to a block 63 representing compass functions. The output of this block 63 is connected on the one hand via a block representing a derivator 64 to a first summing point 65 and on the other hand to a second summing point 66 . The block diagram moreover comprises a block 67 representing measurement values xy of an angular accelerometer. This block 67 is connected to an integrator 68 and further to the first summing point 65 . The output of the first summing point 65 is connected to a block representing an adaptive filter 69 . The output of block 69 is connected as well to the second summing point 66 . A dashed line separates the sensor related blocks 61 , 62 and 67 on the left hand side from the other, digital signal processing related blocks on the right hand side.
The compass signal θ xy that is calculated in block 63 from the magnetometer values m x , m y is differentiated in the derivator 64 with respect to time in order to remove the constant field value. The resulting value indicates the angular velocity based on the magnetic field, but includes high frequency disturbances. The corresponding angular acceleration signal xy is integrated in the integrator 68 . The resulting value indicates the true angular velocity based on the acceleration of the mobile phone, but comprises a low frequency drift. The time constants of derivator 64 and integrator 68 are matched.
The two signals {dot over (θ)} xy output by the derivator 64 and the integrator 68 are compared by means of the summing point 65 in order to separate the disturbances and the low frequency drift of the true angular velocity. The summing point 65 subtracts more specifically the value obtained from the derivator 64 from the value obtained from the integrator 68 . The signal is then passed through the adaptive filter 65 . The adaptive filter applies a high-pass filtering on the received signal in order to separate the disturbances of the signal. The disturbances are further integrated in the adaptive filter 65 in order to obtain an estimate of the angular error of the device for the inertial navigation purposes.
The high-pass filtered estimate of the angular error is then subtracted by the second summing point 66 from the compass heading information θ xy including disturbances, which is output by block 63 . The output of the second summing point 66 is thus a corrected compass heading θ xy,corr for one compass plane.
The system of FIG. 6 can be further improved by using adaptive filters, such as Kalman filters, for the error signal processing.
It is to be noted that the described embodiments constitute only selected ones of a variety of possible embodiments of the invention. | The invention relates to a mobile electronic system. In order to expand and enhance the usability of the mobile electronic system, it is proposed that it comprises a 3D magnetometer 51 performing magnetic measurements in three dimensions and providing data indicative of the current posture of the mobile electronic system based on these measurements. Further, it is proposed that the mobile electronic system comprises processing means 52, 54 processing the data provided by the 3D magnetometer 51 for enabling a posture related presentation of information via output means 12, 42 of the mobile electronic system. The invention relates equally to components of such a system and to a corresponding method. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a sheet material for primary use as shoe insoles.
Before the present invention, shoe insoles of various materials were shown for placement against the lower surface of the feet. Such insoles gradually deform by simple loading and do not relieve the pressure points caused by the uneven contact between the foot and the insole. Eventually insoles do permanently deform due to the deterioration of the insole material over time in response to the continued loading of the material A fitting pad is disclosed in U.S. Pat. No. 4,255,202.
SUMMARY OF THE INVENTION
A principal feature of the present invention is the provision of an improved sheet of material which deforms to a shape which smooths out pressure distribution between the foot and the insole in a relatively short time.
In one embodiment, the sheet material of the invention comprises, a laminate having a plurality of layers comprising a carrier fabric coated on both sides by a waxy material, relatively small granules in the waxy material, and relatively stiff small fibers in the waxy material.
In another embodiment, the sheet material comprises a batt of relatively stiff small fibers having disposed therein hollow glass or plastic microspheres and a matrix of waxy material being bonded to a covered sheet.
A feature of the present invention is that the sheet material may be shaped for use as the insole of a shoe.
A further feature of the present invention is that the fibers and granules may move upon the application of pressures, and yield to form a relatively permanent irregular layer to reduce the forces between the foot and the insole after a short period of time.
Still another feature of the invention is that the fibers and granules become fixed in relation to each other after application of pressure, and the sheet material has been shaped by use, and the fibers and granules retain their relationship and the sheet retains its shape until different forces are applied.
Thus, a feature of the present invention is that the material quickly conforms to reduce or eliminate the pressure points preceived in the contact of the foot and against the insole sheet material.
A feature of the present invention is that when used as an insole, the sheet material provides an "old usedshoe" feel after a relatively short period of time.
Further features will become more fully apparent in the following description of the embodiments of this invention and from the appended claims.
DESCRIPTION OF THE DRAWINGS
In the drawings
FIG. 1 is an elevational view showing the sheet material of the present invention interposed between a foot and the composite midsole/outsole of a shoe in an unloaded condition;
FIG. 2 is an elevational view of the sheet of the present invention in a loaded condition;
FIG. 3 is a sectional view of laminate for the laminate sheet material of one embodiment of the present invention;
FIG. 4-6 are sectional views of the sheet material of another embodiment of the present invention showing its fabrication in a stepwise fashion.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, there is shown a foot 10 having its skeletal bones 12 indicated and the support platform 14 which may comprise any known midsole/outsole combination. Interposed between the foot and the support platform is a sheet of material 16 which serves as an insole. As shown in FIG. 1, insole 16 is of essentially uniform thickness.
When the shoe is loaded by having foot 10 forced against insole 16 on support platform 14, as shown in FIG. 2, the insole 16 deforms and has areas of non-uniform thickness to account for an equalization of pressures from the foot as shown by deformed area 18 under the metatarsal arch 19 and the essentially non-deformed area under the fatty portion 20 of the foot.
Referring now to FIG. 3, there is shown the sheet material 24 of one embodiment of the present invention. The sheet material 24 comprises a laminate 26 of a plurality of individual layers or plies 28 which are placed against each other in the sheet material 24.
Each of the layers 28 comprises a central carrier fabric 30, such as a woven, knitted, nonwoven, or scrim material. In a suitable form, the carrier fabric 30 may comprise a nonwoven material sold under product No. LY143089 by the Kendall Company of Boston, Mass.
Both sides of the carrier fabric 30 are coated by a waxy or adhesive material 32, such as a low molecular weight hydrocarbon or paraffin, which has a relatively low melting point, such as 200° F. The waxy material 32 is sprayed or laid in molten form onto opposed sides of the carrier fabric 30, and the carrier fabric 30 may be any suitable material which will hold the waxy material 32. The waxy material 32 holds the laminate 26 together during use.
As shown, a plurality of granules 34 are placed in the waxy material 32 in its molten condition. The granules 34 may comprise hollow glass microspheres, plastic microspheres, or bubbles preferably having a diameter of less than 100 microns Although the granules 34 are shown on one side of the carrier fabric 30, it is understood that the granules 34 may be placed on both sides of the carrier fabric 30.
A plurality of chopped stiff fibers or flock 36 are also placed in the waxy material 32 in its molten condition. The fibers 36 may comprise a suitable fiber such as Dacron, a trademark of E.I. duPont de Nemours Although the fibers 36 are shown as being placed on one side of the carrier fabric 30, it will be understood that the fibers 36 may be placed on both sides of the fabric 30 in the waxy material 32. Thus, both the granules 34 and fibers 36 are placed in the waxy material 32 while it is in a softened condition, after which the waxy material 32 is allowed to solidify.
The laminate 26 may comprise any suitable number of layers, such as about 10 plies which are placed against each other. The laminate 26 may have durable opposed cuter covering layers 38, such as a suitable nonwoven material The resultant sheet material may have a thickness of about 1/8 inch.
During use, the sheet material 24 deforms responsive to the application of pressure in order to eliminate the pressure points between the foot 10 and the midsole/outsole formation 14 by the movement of the granules and flock within the insole 16 for the shoe. In this manner, the sheet material 24 provides a comfortable feel for the foot in a relatively short period of time. The granules 34 or micropheres provide lightness for the sheet material 24 and are permitted to move around in the waxy material 32 upon the application of pressure. The granules take up space in the waxy material 32, have a high strength, and do not break under the application of loads. Responsive to the the application of pressure, the granules 34 become closely packed, and quickly provide an old shoe feel for the insole 16. Of course, during the application of pressure, the microspheres 34 flow or move in the waxy material 32.
Also, during use, the fibers or flock 36, which may be chopped, interlock, and when weight causes heat to build up in the waxy material 32 which melts somewhat and allows the fibers 36, as well as the granules 34, to move in the laminate 26. The fibers 36 provide strength to the laminate 26, and the fibers migrate and interlock such that they mat up in the deformed sheet material 24.
In this manner, the sheet material 24 yields to pressure in a relatively short period of time, such as a few hours. The sheet material 24 deforms to the pressure profile of the foot, and does not move back to the original shape in order to provide comfort and cushioning for the foot. The sheet will adjust, however, to different pressure profiles taken by the foot. Thus, the fillers comprising the granules 34 and fibers 36 interlock upon the application of pressure for a relatively short period of time, in order to provide conformability by the sheet material 24 to the pressure points
Turning now to FIG. 4-6, another embodiment of the invention is illustrated in the sequense in which the composite sheet is manufactured.
The composite sheet 50 comprises a single consolidated web having a bondable cover sheet 40 which is relatively impervious to the migration of the waxy or adhesive material to which is adhered a batt 42 of fibrous materials. As shown in FIG. 4, fibers 44 are loosely packed giving the batt a low bulk density.
FIG. 5 shows the batt 42 bonded to cover sheet 40 by means of adhesive layer 46 and having granules or microspheres 48 dispensed therein.
FIG. 6 shows the composite after hot wax has been sprayed on the batt 42, wicking through the fibers causing the fibers 44 and the granules or microspheres 48 to pack down to form a sheet of material suitable for use in shoe insoles.
The foregoing 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. | A sheet material which yields under non-uniform pressures caused by irregularities of contact between two relatively hard surfaces adapted to provide a more uniform pressure distribution comprising the combination of relatively small granules and relatively small stiff fibers in a matrix of waxy material adhered to a cover sheet of flexible material. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to endoluminal prosthetic conduit systems and in particular to methods and components for joining together endoluminal prosthetic conduit components.
BACKGROUND OF THE INVENTION
[0002] Stents or stent grafts are forms of transluminal prosthetic components which are used to maintain, open or dilate stenotic lesions in body lumens or to cover and repair an aneurysm. It is often the case that an aneurysm occurs at a branch or bifurcation in a vessel. To repair such an aneurysm using modular components, one current technique is to initially deploy across the aneurysm a main body stent or stent graft having a side wall opening. The side wall opening is aligned with the side branch ostium. A second stent or stent graft is then deployed through the main body stent side wall opening and into the side branch vessel. This modular repair approach requires the modular components to be effectively sealed at their connection points to prevent blood leakage into the aneurysm. In addition the modular components must be locked or joined together to prevent subsequent relative displacement of the modular components. Similar requirements apply to those procedures that use multiple stent grafts that are coupled together to increase the effective length of the repair device.
SUMMARY OF THE INVENTION
[0003] The present invention provides modular prosthetic conduit systems such as stent or stent graft systems. The modular prosthetic conduit systems may be tailored for the repair of aneurysms or for the repair of compromised vessel walls. The systems incorporate various embodiments for the secure interlocking of the multiple modular components used in a vessel repair procedure.
[0004] An aspect of the invention includes a prosthetic conduit system comprising: an expandable main conduit having a first open end, a second open end, a main conduit wall extending therebetween, an outer conduit surface, and an inner conduit surface having at least one protuberance thereon; an expandable secondary conduit having a first open end, a second open end, a secondary conduit wall extending therebetween, and attachment portion extending at an angle of less than 90 degrees from the secondary conduit wall when in a deployed state; and wherein at least a portion of the secondary conduit is sized to fit inside the main conduit.
[0005] A further aspect of the invention includes a prosthetic conduit system comprising: an expandable main conduit having a first open end, a second open end, a main conduit wall extending therebetween, at least one opening through the main conduit wall, and an internal channel having an inner surface, an outer surface, a first open end located within the main conduit and a second open end at the opening in the main conduit wall; an expandable secondary conduit having a first open end, a second open end, a secondary conduit wall extending therebetween, and attachment portion extending at an angle of less than 90 degrees from the secondary conduit wall when in a deployed state; and wherein at least a portion of the secondary conduit is sized to fit inside the internal channel and through the opening in the main conduit wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a side view of a main conduit with an interconnected secondary conduit as implanted across an aortic aneurysm.
[0007] FIG. 2 is a perspective view of a main conduit having an internal protuberance.
[0008] FIG. 3 is a cross-sectional view of a main conduit having an internal protuberance.
[0009] FIG. 4 is a perspective view of a main conduit joined to a secondary conduit.
[0010] FIGS. 5A and 5B are perspective and side views of a secondary conduit having an attachment portion. Shown is a defined angle between an attachment portion and a secondary conduit longitudinal axis or secondary conduit wall.
[0011] FIG. 6 is a cross-sectional view of a main conduit having an internal protuberance that is discontinuous or segmented.
[0012] FIG. 7 is a cross-sectional view of a main conduit having an internal protuberance that incorporates stiffening support structures.
[0013] FIG. 8 is a cross-sectional view of a main conduit having an internal stent or support structure with barbs or hooks configured to engage a secondary conduit.
[0014] FIGS. 9A and 9B are cross-sectional views of a main conduit having internal barbs or internal hooks configured to engage a secondary conduit.
[0015] FIGS. 10A and 10B are perspective views of a secondary conduit having external barbs or external hooks configured to engage a main conduit.
[0016] FIG. 11 is a perspective view of a secondary conduit having an external cuff that is configured to engage and lock onto an open end of a support channel.
[0017] FIG. 12 is a cross-sectional view of a main conduit having two opposed cuffs.
[0018] FIG. 13 is a side view of a secondary conduit having two opposed cuffs.
[0019] FIG. 14 is a perspective view of a main conduit and an interconnected secondary conduit.
[0020] FIGS. 15 A and 15 B are side views of main conduits according to certain aspects of the invention.
[0021] FIGS. 16 A and 16 B are side views of main conduits and secondary conduits according to certain aspects of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] A better understanding of the invention will be had with reference to the several figures.
[0023] Shown in FIG. 1 is a main conduit 20 having a first open end 22 and a second open end 24 . A secondary conduit 26 is shown inserted into the second open end 24 of the main conduit 20 . The secondary conduit 26 is shown as a bifurcated endoluminal device bridging an aortic aneurysm 28 . The main conduit 20 and the secondary conduit 26 are expanded and share an engagement portion or engagement length 30 . In an aspect of the invention the main conduit 20 and the secondary conduit 26 can be self-expanding or balloon expandable.
[0024] A main conduit can have various configurations including stent grafts with or without side-branches or side-branch openings. Stent grafts can be fabricated, for example, according to the methods and materials as generally disclosed in U.S. Pat. Nos. 6,042,605; 6,361,637; and 6,520,986 all to Martin et al. Details relating to the fabrication and materials used for a main conduit with an internal side branch support tube or channel can be found in, for example, U.S. Pat. No. 6,645,242 to Quinn.
[0025] The main conduit comprises at least one protuberance on the inner surface of the main conduit. Protuberances according to an aspect of the invention can be in many forms. For example, shown in FIG. 2 is a perspective view of a main conduit 20 having a first open end 22 and a second open end 24 . Internal to the main conduit is protuberance in the form of cuff 32 on the inner surface of the main conduit.
[0026] FIG. 3 is a cross-sectional view of a main conduit 20 as viewed along the cross-sectional plane 3 of FIG. 2 . Shown is a section of a main conduit 20 , first and second open ends 22 , 24 and protuberance 32 . The protuberance 32 is in the form of a cuff 34 that is configured to engage an attachment portion of a secondary conduit. A protuberance or cuff can have various configurations and can be fabricated, for example, from tubes, sheets or films formed into tubular shapes, woven or knitted fibers or ribbons or combinations thereof. Protuberance or cuff materials can include conventional medical grade materials such as nylon, polyester, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylchloride, polyurethane and elastomeric organosilicon polymers. A protuberance or cuff can be joined to a graft or stent wall by sutures, medical grade adhesives or thermoplastics or can be integral to the graft or stent wall.
[0027] Shown in FIG. 4 is a main conduit 20 having a first open end 22 and a second open end 24 and a wall 25 extending between the two open ends. The wall defines an outer conduit surface 21 and an inner conduit surface 23 . A secondary conduit 26 is shown inserted into the second open end 24 of the main conduit 20 . The secondary conduit 26 has a first open end 27 a second open end 29 and a wall 31 extending between the two open ends. The secondary conduit 26 has an attachment portion 36 shown in a deployed state as flared apices of a stent support structure. The attachment portion 36 is shown engaged into the protuberance 32 of main conduit 20 . The flared apices of the stent support are therefore engaged and interlocked into the cuff 34 , preventing or inhibiting the secondary conduit 26 from dislodging toward the direction indicated by arrow 38 . An improved sealing surface between the secondary and the main conduits may also be provided by the protuberance 32 . Forces exerted by the flow of blood may encourage or drive the flared apices of the stent support into contact with or full engagement with the cuff 34 .
[0028] Shown in FIG. 5A is a secondary conduit 26 having open ends 27 and 29 , a wall 31 extending from open end 27 to open end 29 , a longitudinal axis 40 and attachment portion 36 shown in an unconstrained or deployed state as flared-out apices of a support stent. The inner surface 42 of the attachment portion 36 defines axis 44 . An angle 46 is shown between the secondary conduit longitudinal axis 40 (and the wall 31 ) and the attachment portion axis 44 . Shown is an angle of about 45°. Angle 46 can be any angle less than about 90°. For example angle 46 can be just less than 90°, about 80°, about 70°, about 60°, about 45°, about 30°, about 20° or less.
[0029] Similar to FIG. 5A , shown in FIG. 5B is a secondary conduit 26 having open ends 27 and 29 , a wall 31 extending from open end 27 to open end 29 , a longitudinal axis 40 and an attachment portion 36 shown in a deployed state as flared-out apices of a support stent. The inner surface 42 of the attachment portion 36 defines axis 44 . An angle 46 ′ is shown between the secondary conduit wall 31 and the attachment portion axis 44 . Shown is an angle of about 45°.
[0030] Various alternate configurations of attachment portions and/or protuberances are possible. For example the protuberance 32 can be discontinuous, forming discrete protuberance segments along the inner wall of a main conduit. A main conduit can have two, three, four or five or more discrete protuberance segments, spaced along the inner wall. Shown in FIG. 6 is a cross-sectional view of a main conduit 20 as viewed along the cross-sectional plane 3 as defined in FIG. 2 . Shown is a section of a main conduit 20 , first and second open ends 22 , 24 and discontinuous protuberances 34 . The protuberances 34 form a series of cuffs that are configured to engage attachment portions of a secondary conduit, such as depicted in FIG. 4 .
[0031] To assist in the engagement of an attachment portion, a protuberance can incorporate semi-rigid or densified segments along its length. Such semi-rigid sections along a protuberance may prevent or inhibit the protuberance from collapsing. Shown in FIG. 7 is a cross-sectional view of a main conduit 20 as viewed along the cross-sectional plane 3 as defined in FIG. 2 . Shown is a section of a main conduit 20 , first and second open ends 22 , 24 and a protuberance, shown as cuff 34 . Densified or semi-rigid sections 62 are incorporated into the protuberance to add rigidity to cuff 34 and thus inhibiting or even preventing the cuff from collapsing. Semi-rigid sections 62 can be incorporated into segmented or discontinuous protuberances as previously described in FIG. 6 .
[0032] Semi-rigid or densified segments may be formed from conventional medical grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethylmethacrylate, polypropylene, polytetrafluoroethylene, polytrifluorochlorethylene, polyvinylchloride, polyurethane, elastomeric organosilicon polymers; metals such as stainless steels, cobalt-chromium alloys and nitinol and biologically derived materials such as pericardium and collagen. Semi-rigid or densified segments can also comprise bioresorbable materials such as poly(amino acids), poly(anhydrides), poly(caprolactones), poly(lactic/glycolic acid) polymers, poly(hydroxybutyrates) and poly(orthoesters).
[0033] The at least one protuberance of the main conduit may comprise an internal stent or support structure that incorporates barbs, hooks or other suitable configurations to engage and/or lock with a secondary conduit. Shown in FIG. 8 is a cross-sectional view of a main conduit 20 as viewed along the cross-sectional plane 3 of FIG. 2 . Shown is a section of a main conduit 20 , first and second open ends 22 , 24 and an internal stent or support structure 64 . Protruding out of the stent or support structure 64 are a series of barbs or hooks 66 . The barbs or hooks are oriented inwards toward the center of the main conduit and are configured to engage and/or lock onto a wall or attachment portion of a secondary conduit.
[0034] A main conduit may have a series of internal, barbs or hooks that are integral to the main conduit wall or integral to a main conduit support stent. For example if the main conduit has a stent support structure, portions of the stent can be formed into hooks or barbs that are configured to engage and lock a secondary conduit. Shown in FIG. 9A is a cross-sectional view of a main conduit 20 as viewed along the cross-sectional plane 3 of FIG. 2 . Shown is a section of a main conduit 20 , first and second open ends 22 , 24 and a series of internal barbs 68 . Similarly shown in FIG. 9B are a series of internal hooks 70 . The barbs or hooks are oriented inwards toward the center of the main conduit and are configured to engage and/or lock onto an external wall of a secondary conduit. Barbs or hooks may be formed from conventional medical grade materials such as those listed above.
[0035] Secondary conduits can also incorporate various forms of attachment portions to engage and/or lock onto main conduits. For example shown in FIG. 10A is a perspective view of a secondary conduit 26 having first and second open ends 27 , 29 and a wall 31 . Protruding outwardly away from the secondary conduit wall 31 are a series of external barbs 72 . Similarly, shown in FIG. 10B are a series of external hooks 74 . The barbs or hooks are oriented outwardly away from the center of the secondary conduit and are configured to engage and lock onto an internal wall and/or protuberance of a main conduit.
[0036] A secondary conduit may also incorporate an external cuff that is configured to engage a main body protuberance or an open end of an internal channel. For example shown in FIG. 11 is a perspective view of a secondary conduit 26 having first and second open ends 27 , 29 and a wall 31 . Formed about the first open end 27 is an external cuff 76 configured to engage an internal protuberance or a first open end of an internal channel of a main conduit. The external cuff may incorporate semi-rigid sections as shown in FIG. 7 to add rigidity to the cuff.
[0037] A main conduit may have opposed anchoring cuffs that prevent a secondary conduit from being displaced in two directions. Shown in FIG. 12 is a cross-sectional view of a main conduit 20 having two opposed engagement cuffs 78 . The cuffs 78 are configured in a linear state as shown in FIG. 2 and FIG. 3 . The cuffs 78 are configured to engage attachment portions 36 of a secondary conduit 26 . The engagement of the attachment portions 36 to the cuffs 78 inhibit or prevent dislodgement of the secondary conduit in the two directions shown by arrows 38 and 80 .
[0038] Secondary conduits can also incorporate attachment portions in the form of bi-directional cuffs that inhibit or prevent dislodgement in two directions. Shown in FIG. 13 , is a secondary conduit 26 having bi-directional cuffs 82 . The bi-directional cuffs 82 are configured to engage opposed main conduit cuffs as shown in FIG. 12 .
[0039] In some surgical procedures it is desirable to have a side-branched endovascular device, particularly for the repair of a vessel that is in close proximity to branched vasculature.
[0040] FIG. 14 is a perspective view of an alternate main conduit 50 having a first open end 22 and a second open end 24 . Within the main conduit 50 is an internal channel 54 having a first open end 56 and a second open end 58 that is aligned to an opening 60 in the main conduit wall 25 . Such a main conduit can be fabricated according to the teaching in U.S. Pat. No. 6,645,242 to Quinn. A secondary conduit 26 having a first open end 27 , a second open end 29 , a wall 31 , and an attachment portion 36 in a deployed state is shown inserted into the internal channel 54 . The secondary conduit 26 is shown exiting out through the second open end 58 of the internal channel 54 and through the opening 60 in the main conduit wall. The attachment portion 36 is configured to engage and/or interlock onto the first open end 56 of the internal channel. This interlocking may prevent the dislodgement of the secondary conduit 26 along the direction depicted by arrow 38 . Forces exerted by the flow of blood may encourage or drive the attachment portion 36 into full contact with the first open end 56 of the internal channel 54 .
[0041] Stents can have various configurations as known in the art and can be fabricated, for example, from cut tubes, wound wires (or ribbons) or flat patterned sheets rolled into a tubular form. Stents can be formed from metallic, polymeric or natural materials and can comprise conventional medical grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethylmethacrylate, polypropylene, polytetrafluoroethylene, polytrifluorochlorethylene, polyvinylchloride, polyurethane, elastomeric organosilicon polymers; metals such as stainless steels, cobalt-chromium alloys and nitinol and biologically derived materials such as bovine arteries/veins, pericardium and collagen. Stents can also comprise bioresorbable materials such as poly(amino acids), poly(anhydrides), poly(caprolactones), poly(lactic/glycolic acid) polymers, poly(hydroxybutyrates) and poly(orthoesters).
[0042] Grafts can have various configurations as known in the art and can be fabricated, for example, from tubes, sheets or films formed into tubular shapes, woven or knitted fibers or ribbons or combinations thereof. Graft materials can include conventional medical grade materials such as nylon, polyester, polyethylene, polypropylene, polytetrafluoroethylene (including expanded polytetrafluoroethylene (“ePTFE,”)), polyvinylchloride, polyurethane and elastomeric organosilicon polymers.
[0043] Stents can be used alone or in combination with graft materials. Stents can be configured on the external or internal surface of a graft or may be incorporated into the internal wall structure of a graft. Moreover, main and secondary conduits can incorporate various stent or support structures. For example as shown in FIG. 15A , a main conduit 20 may comprise separate stent segments 90 A and 92 A, positioned at or near the first and second open ends 22 and 24 of the main conduit 20 . Similarly the stent segments 90 A and 92 A can comprise a single stent 94 A extending from the first open end 22 to the second open end 24 of the main conduit 20 .
[0044] Shown in FIGS. 16A and 16B are secondary conduits 26 tailored to be inserted into main conduits 22 along direction arrows 96 . As shown in FIG. 16A , a secondary conduit 26 can incorporate stents 90 B and 92 B at or near the first and second open ends 27 and 29 of the secondary conduit 26 . Similarly the stent segments 90 B and 92 B can comprise a single stent 94 B extending from the first open end 27 to the second open end 29 of the secondary conduit 26 .
[0045] Expandable conduits according to the invention can be delivered in a constrained state endoluminally by various catheter based procedures known in the art. For example self-expanding endoluminal devices can be loaded onto the distal end of a catheter, compressed and maintained in a constrained state by an external sheath. The sheath can be folded to form a tube positioned external to the compressed device. The sheath edges can be sewn together with a deployment cord that forms a “chain stitch”. Once the constrained device is positioned at a target site within a vessel the device can be deployed. In the deployed state, the device may still be constrained by the vasculature or by another device. For example a device may assume a diameter of 20 mm when fully unconstrained. This same device may be deployed into a vessel (or other device) having a lumen diameter of 15 mm and would therefore be “constrained” in the deployed state. An “un-constrained state” can therefore be defined as the state assumed by the device when there are no external forces inhibiting the full expansion of the device. A “constrained state” can therefore be defined as the state assumed by the device in the presence of external forces that inhibit the full expansion of the device. The deployed state can be defined as the state assumed by the device when expanded into a vessel or other device.
[0046] To release and deploy the constrained device, one end of the deployment cord can be pulled to disrupt the chain stitch, allowing the sheath edges to separate and release the constrained device.
[0047] Constraining sheaths and deployment cord stitching can be configured to release a self-expanding device in several ways. For example a constraining sheath may release a device starting from the proximal device end, terminating at the distal device end. In other configurations the device may be released starting from the distal end. Self expanding devices may also be released from the device center as the sheath disrupts towards the distal and proximal device ends. Details relating to constraining sheath materials, sheath methods of manufacture and main body compression techniques can be found in U.S. Pat. No. 6,352,561 to Leopold et al., and U.S. Pat. No. 6,551,350 Thornton et al.
[0048] In the deployment of a secondary conduit for example, the secondary conduit can be released from a constraining sheath starting at the proximal (or hub) end of the constrained conduit. In typical procedures, the attachment portion of the secondary conduit is located about the proximal end of the conduit and in an aspect of the invention this proximal end is the first end released from a constraining sheath, thus also deploying the attachment portion.
[0049] While particular embodiments of the present invention have been illustrated and described above, the present invention should not be limited to such particular illustrations and descriptions. It should be apparent that changes and modifications may be incorporated and embodied as part of the present invention within the scope of the following claims. | A modular prosthetic conduit system such as a stent or stent graft system tailored for the repair of aneurysms or other compromised vessel walls. The stent or stent graft system incorporates various means to interlock the multiple modular components used in the repair procedure. The present invention further provides a modular stent graft system tailored for the repair of aneurysms or other compromised vessel walls that cross or are adjacent to a branch or bifurcation in a vessel. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional application based upon U.S. provisional patent application Ser. No. 60/991,200, entitled “AGRICULTURAL HARVESTER SPEED CONTROL”, filed Nov. 29, 2007, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates generally to agricultural harvesters. More particularly, it relates to speed control of auxiliary equipment associated with agricultural harvesters.
BACKGROUND OF THE INVENTION
[0003] An agricultural harvester typically includes a self-propelled vehicle on which an engine and various pieces of auxiliary equipment are mounted. The engine, through several drive trains, drives the auxiliary equipment on the agricultural harvester which typically includes a large threshing rotor, cleaning fans, drive wheels, straw choppers, straw walkers, sieves, chaffers, and headers, among other devices.
[0004] Many of these devices are driven by mechanical devices such as gear boxes, rotating shafts, belts, pulleys, and hydraulic pumps connected to the engine. In one common arrangement, the engine is coupled to the large threshing rotor and to the cleaning fan by a drive train which includes a series of mechanical drive elements such as gear boxes driven by rotating shafts, belts and pulleys. In a common arrangement, one or more pulleys, having a variable pulley diameter, is disposed in the drive train between the engine and the threshing rotor or the cleaning fan, to control the speed of the rotor or the cleaning fan with respect to the engine.
[0005] One drawback of these variable pulleys is their slow response time. When a signal is sent to the variable pulley to command a change in its diameter, and thus a change in its speed relative to the engine speed, it takes a relatively long amount of time to affect this change. Variable pulleys cannot tolerate rapid changes in pulley diameter under load without suffering undue wear to the belt and pulley.
[0006] For this reason, adjustments are seldom made to the variable pulley diameter. Changes in the diameter of the variable pulley function to change the speed of the rotor or the cleaning fan with respect to the engine. As a general matter, the operator typically selects a new desired speed of the rotor or the cleaning fan, and the control system that controls the diameter of the pulley then establishes a new pulley diameter that will provide that new desired speed (assuming the engine keeps running at the same speed). The control system then stops adjusting the diameter of the pulley, at least until the operator requests a new desired speed.
[0007] If the load on the agricultural harvester increases, such as by running into a heavy crop or starting to climb a hill, then the engine speed will drop. When the engine speed drops, the rotor speed and the cleaning fan speed drop proportionally.
[0008] Similarly, if the load on the agricultural harvester is reduced, for example, by the crop thinning or the harvester starting to go downhill, the engine speed will increase. When the engine speed increases, the rotor and the cleaning fan speed increase proportionately.
[0009] In one prior art arrangement, the operator is able to select a desired new speed of the rotor or the fan using an operator input device such as a button, a knob, or a lever to select a desired new rotor or fan speed. In response to this, a control system increases or decreases the diameter of the variable pulley over a period of several seconds, until the speed of the rotor or fan reaches the desired new speed. Once the control system determines that the rotor or fan speed is at the desired new speed, it stops adjusting the diameter of the variable pulley. From that time on, as the engine speed changes, the rotor or fan speed changes proportionately, and the control system makes no further adjustment to the diameter of the variable pulley.
[0010] Unfortunately, this algorithm, while relatively simple, will not always give the results the operator anticipates. For example, since it takes a finite but nontrivial period of time for the control system to change the diameter of the pulley, occasionally the engine speed changes at the same time.
[0011] To illustrate the problem from the operator's perspective, imagine the following situation. The cleaning fan is operating at 1150 rpm and the engine is operating at 2300 rpm. The operator desires to reduce the fan speed to 1050 rpm, and operates the operator input device to select this speed. The control system, responding to the operator input device, begins the process of changing the diameter of the pulley to reduce the speed of the fan.
[0012] Shortly after the operator selects a desired new speed of 1050 rpm, the engine experiences a heavy load and the engine speed drops to 2100 rpm. When the engine speed drops to 2100 rpm, the cleaning fan speed drops automatically and coincidentally to the new target speed of 1050 rpm since the engine and the cleaning fan operate at speeds that are strictly proportional due to the fixed ratio gear train that couples them together.
[0013] The control system, even if it has made no change in the diameter of the pulley, senses that the fan is now running at the desired new speed of 1050 rpm. At this point, the control system ceases to adjust the diameter of the variable pulley, assuming that the control system adjustments are complete, based on the cleaning fan operating at the desired new speed. The control system stops adjusting the diameter of the pulley, even though it has made no adjustment to the diameter of the variable pulley.
[0014] The operator will immediately notice this failure to go to the desired new speed when the engine shortly recovers from its increased load and speeds back up to its normal operating speed of 2300 rpm. When this happens, the cleaning fan will again return to its original operating speed of 1150 rpm. The control system in effect mistakes the change in the cleaning fan speed caused by a temporary drop in the engine speed as actually setting a desired new cleaning fan speed.
[0015] What is needed in the art is a system for accommodating changes in engine speed while an adjustment is made to the cleaning fan (or threshing rotor) speed so that the operator's natural expectations are preserved.
SUMMARY OF THE INVENTION
[0016] The invention in one form is directed to a computer-controlled method of controlling the speed of an agricultural harvester load coupled to an agricultural harvester engine of an agricultural harvester by a power transmitting arrangement having various output speeds. The method includes the steps of electronically receiving a desired new load speed from an operator when the engine is operating at an initial engine speed and electronically driving the power transmitting arrangement through a sequence of the various output speeds until the actual speed of the agricultural harvester load and the actual speed of the agricultural harvester engine are in the same ratio to each other as the desired new load speed and the initial engine speed.
[0017] The step of electronically driving a variable pulley may further include the steps of repeatedly and electronically receiving the actual speed of the agricultural harvester engine from a first speed sensor; repeatedly and electronically receiving the actual speed of the agricultural harvester load from a second speed sensor; repeatedly and electronically calculating a ratio of the actual speeds of the harvester engine and the harvester load; repeatedly and electronically comparing the ratio of the actual speeds to a ratio of the new desired speed and the initial engine speed; and repeatedly and electronically changing the diameter of the variable pulley until the two ratios are the same.
[0018] The invention in another form is directed to an agricultural harvester including an agricultural harvester engine, an agricultural harvester load, a power transmitting arrangement, and a system for controlling the actual speed of the agricultural harvester load. The agricultural harvester engine has an actual speed when operating and the agricultural harvester load has an actual speed when operating. The power transmitting arrangement connects the load to the engine. The agricultural harvester load is coupled to the agricultural harvester engine of the agricultural harvester by the power transmitting arrangement. The system includes a first sensor coupled to the engine for sensing the actual speed of the engine and a second sensor coupled to the load for sensing the actual speed of the load. The system also includes a power transmitting arrangement, an operator input device, and a control unit. The power transmitting arrangement couples the load to the engine and is configured to provide a selectable plurality of speeds of the load for a given speed of the engine. The operator input device receives input from an operator of the agricultural harvester requesting a change in speed of the load to a revised load speed. The control unit receives a signal from the first sensor indicative of the actual speed of the engine, a signal from the second sensor indicative of the actual speed of load and a signal from the operator input device indicative of the desired load speed. The control unit calculates the ratio of the actual engine speed when the input is received from the operator to the desired load speed. The control unit sends a signal to the power transmitting arrangement to change the actual speed of the load to a different one of the selectable plurality of speeds corresponding to a speed having the same ratio to the actual speed of the engine as the desired load speed has to the actual engine speed when the input was received from the operator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The FIGURE shows an embodiment of a drive train of an agricultural harvester in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring now to the FIGURE, a drive train 100 of an agricultural harvester includes an engine 102 that is coupled to and drives a series of first mechanical drive elements 104 , here illustrated in simplified form as a gear train 104 , although it may be any combination of shafts, gears, belts, pulleys, or other mechanical drive elements. Mechanical drive elements 104 are coupled to a power transmitting arrangement 105 . Power transmitting arrangement 105 , as shown, includes a first pulley 106 which, in turn, is coupled to and drives a second pulley 108 . Belt 110 couples the pulleys 106 and 108 together to transmit power therebetween. Pulley 106 , pulley 108 and belt 110 form power transmitting arrangement 105 in the form of a pulley and belt arrangement 111 . Pulley 108 is coupled to and drives a load 112 , which may be, for example, the rotor of an agricultural harvester, or a cleaning fan. In this typical arrangement, all the mechanical elements in the drive train 100 rotate at speeds that are in fixed proportion to each other, unless, for example, the diameter of one of the pulleys is changed, or a gear ratio of a gearbox in drive train 100 is changed.
[0021] A first speed sensor 114 is coupled to one of the first mechanical drive elements 104 in the drive train 100 that is on the engine side of pulley and belt arrangement 111 . In this embodiment, first speed sensor 114 is shown connected to engine 102 . In alternative embodiments, first speed sensor 114 is connected to any of the first mechanical drive elements 104 between engine 102 and pulley 106 . Wherever first speed sensor 114 is located, it provides a speed signal 115 proportional to the speed of one of the first mechanical drive elements 104 on the drive (i.e. the engine) side of pulley and belt arrangement 111 .
[0022] A second speed sensor 116 is coupled to one of second mechanical drive elements 117 in the drive train 100 that is on the load side of pulley and belt arrangement 111 . In this embodiment, speed sensor 116 is coupled directly to load 112 . Alternatively, it could be connected to second pulley 108 or to any of the second mechanical drive elements 117 coupling second pulley 108 to load 112 . Wherever second speed sensor 116 is located, it provides a speed signal 119 proportional to the speed of one of the second mechanical drive elements 117 on the load (i.e. the cleaning fan or threshing rotor) side of the pulley and belt arrangement 111 .
[0023] Pulley 106 and/or 108 is a variable diameter pulley. By “variable diameter” we mean that the diameter of belt 110 as it travels over the pulley can be adjusted, typically by moving one side of the pulley closer to or further apart from the other side of the pulley, to close or, alternatively, to open the gap therebetween. Typically, the inner face of the sides of the pulley taper away from each other in the direction of the outer diameter of the pulley, so that belt 110 contacts the inner faces closer to the outside diameter when the sides that are closer together. As the belt moves closer to the outside diameter of the second pulley 108 , the shaft supporting belt 110 rotates more slowly.
[0024] This adjustment can be affected by a mechanical device, such as a mechanical linkage that forces the pulley sides together, or it may be hydraulic, such as by a piston that is moved by hydraulic fluid under pressure to force the pulley sides together.
[0025] In the embodiment shown here, second pulley 108 is a variable diameter pulley, and is coupled to actuator 118 that is configured to change the diameter of second pulley 108 when so commanded by a control system 120 .
[0026] Control system 120 is coupled to drive train 100 to vary the speed of agricultural harvester load 112 relative to agricultural harvester engine 102 . Control system 120 includes an electronic control unit (ECU) 122 , an operator input device 124 (here shown as a keyboard), and an operator signaling device 126 (here illustrated as a visual display). Input device 124 and signaling device 126 are communicatively coupled to ECU 122 .
[0027] ECU 122 includes a digital microprocessor having random access memory (RAM), read only memory (ROM), and signal conditioning circuits that permit ECU 122 to drive operator signaling device 126 and to receive and process signals 123 from operator input device 124 , to receive and process signals from speed sensors 114 and 116 , and to transmit signals sufficient to drive actuator 118 . ECU 122 is configured to indicate a speed of load 112 with signaling device 126 , preferably by displaying the speed as numeric values on visual display device 126 . ECU 122 is configured to receive speed command signals that the operator enters using operator input device 124 .
[0028] ECU 122 is also coupled to speed sensors 114 and 116 to receive signals therefrom that indicate the speed of one of the mechanical drive element 104 on the drive side of the pulley and belt arrangement 111 (in this case the engine) and to receive signals that indicate the speed of one of the second mechanical drive elements 117 on the load side of pulley and belt arrangement 111 (in this case, agricultural harvester load 112 ).
[0029] ECU 122 is also coupled to actuator 118 to drive actuator 118 and, thereby, to change the diameter of second pulley 108 . In this embodiment, actuator 118 is configured to vary the diameter of second pulley 108 . In other embodiments (not shown) first pulley 106 is a variable diameter pulley and actuator 118 is coupled to pulley first 106 to vary the diameter of first pulley 106 . In operation, ECU 122 continuously monitors the speed of load 112 , reading second speed sensor 116 and displaying it on signaling device 126 . Whenever the operator wishes to change the speed of load 112 , he manipulates operator input device 124 to select a desired new speed for load 112 , and this desired new speed is transmitted to ECU 122 .
[0030] On receipt of this speed, ECU 122 transmits the desired load speed to operator signaling device 126 . ECU 122 also reads the actual engine speed indicated by speed sensor 114 at the same time and calculates a new speed ratio. The speed ratio being the desired new load speed divided by the actual engine speed at the moment the operator selected the desired new load speed and therefore before the engine speed has a chance to change significantly.
[0031] It is this new speed ratio that the control system 120 uses to vary the diameter of second pulley 108 . Once ECU 122 has established the new speed ratio (which can be thought of generally as the ratio of engine speed to load speed), ECU 122 sends a signal to actuator 118 to change the diameter of second pulley 108 .
[0032] As the diameter of second pulley 108 changes, load 112 on the engine 102 may change, either due to decreasing or increasing the load on engine 102 because the diameter of second pulley 108 is changing, or because of external conditions, such as changing ground terrain or density of the crop.
[0033] When ECU 122 changes the diameter of second pulley 108 , it also reads speed signals from first speed sensor 114 and second speed sensor 116 and calculates a ratio of the two. This instantaneous speed ratio changes as the diameter of second pulley 108 changes, the ratio gradually approaching the new speed ratio established at the outset of the speed change process. The diameter of second pulley 108 is typically not changed randomly, but is gradually moved stepwise from a smaller to a larger diameter, or a larger to a smaller diameter, depending on which change will cause the actual speed ratio to approach the new speed ratio.
[0034] If, for some reason, the actual speed ratio overshoots the new speed ratio during this adjustment process (i.e. the 2 speed ratios pass each other in value and start growing farther and farther apart), ECU 122 is configured to reverse the direction of change of the diameter of the variable pulley in order to make the actual speed ratio again approach the new speed ratio.
[0035] ECU 122 is configured to keep sequentially repeating these steps of changing the diameter of second pulley 108 and reading the speed signals from speed sensors 114 and 116 until eventually the instantaneous speed ratio equals the new speed ratio (or alternatively comes within a predetermined value from the new speed ratio). When this happens, ECU 122 is configured to stop changing the diameter of second pulley 108 and exit its speed control loop until the operator enters another desired new load speed, at which time the entire process is repeated.
[0036] By controlling the diameter of the variable pulley based upon the ratio of engine speed to rotor speed instead of controlling the diameter of the variable pulley based upon the rotor speed alone, control system 120 becomes immune to any drift or change in engine speed as ECU 122 changes the diameter of second pulley 108 .
[0037] Once the speed changing process terminates, and once the load 112 on the engine 102 returns to its typical operating load and the engine speed will return to its original speed, i.e. the engine speed at the time the operator originally requested a desired new load speed, and the actual speed of load 112 will equal the desired new load speed.
[0038] Using this process, control system 120 is rendered immune to transient changes in engine speed, and the operator achieves what he desires: the load rotating at the desired speed when engine 102 is running at its initial speed.
[0039] The actual calculations described above need not be performed in the order they are described. The calculations can proceed in any order as long as the end result is changing the diameter of second pulley 108 until it permits the engine and the load to rotate with respect to each other at speeds that are proportional to the initial engine speed and the desired load speed selected by the operator. Changing the order of calculations to any arbitrary sequence is well known to programmers skilled in the art.
[0040] Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. | A computer-controlled method of controlling the speed of an agricultural harvester load that is coupled to an agricultural harvester engine by a power transmitting arrangement having various output speeds. The method includes the steps of electronically receiving a desired new load speed from an operator when the engine is operating at an initial engine speed, and electronically driving the power transmitting arrangement through a sequence of the various output speeds until the actual speed of the agricultural harvester load and the actual speed of the agricultural harvester engine are in the same ratio to each other as the desired new load speed and the initial engine speed. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a system comprising a device for neural stimulation of a patient's cochlea and a programming unit for adjusting the stimulation device.
[0003] 2. Description of Related Art
[0004] The sense of hearing in human beings involves the use of hair cells in the cochlea that convert or transduce acoustic signals into auditory nerve impulses. Hearing loss, which may be due to many different causes, is generally of two types: conductive and sensorineural. Conductive hearing loss occurs when the normal mechanical pathways for sound to reach the hair cells in the cochlea are impeded. These sound pathways may be impeded, for example, by damage to the auditory ossicles. Conductive hearing loss may often be overcome through the use of conventional hearing aids that amplify sound so that acoustic signals can reach the hair cells within the cochlea. Some types of conductive hearing loss may also be treated by surgical procedures.
[0005] Sensorineural hearing loss, on the other hand, is caused by the absence, destruction or malfunction of the hair cells in the cochlea which are needed to transduce acoustic signals into auditory nerve impulses. People who suffer from sensorineural hearing loss may be unable to derive significant benefit from conventional hearing aid systems, no matter how loud the acoustic stimulus is. This is because the mechanism for transducing sound energy into auditory nerve impulses has been damaged. Thus, in the absence of properly functioning hair cells, auditory nerve impulses cannot be generated directly from sounds.
[0006] To overcome sensorineural hearing loss, numerous auditory prosthesis systems (e.g., cochlear implant (CI) systems) have been developed. Auditory prosthesis systems bypass the hair cells in the cochlea by presenting electrical stimulation directly to the auditory nerve fibers. Direct stimulation of the auditory nerve fibers leads to the perception of sound in the brain and at least partial restoration of hearing function.
[0007] To facilitate direct stimulation of the auditory nerve fibers, a lead having an array of electrodes disposed thereon may be implanted in the cochlea of a patient. The electrodes form a number of stimulation channels through which electrical stimulation pulses may be applied directly to auditory nerves within the cochlea. An audio signal may then be presented to the patient by translating the audio signal into a number of electrical stimulation pulses and applying the stimulation pulses directly to the auditory nerve within the cochlea via one or more of the electrodes.
[0008] Typically, the audio signal, which usually is captured by a microphone, is divided into a plurality of analysis channels, each containing a frequency domain signal representative of a distinct frequency portion of the audio signal, wherein the frequency domain signal in each analysis channel may undergo signal processing, such as by applying channel-specific gain to the signals. The processed frequency domain signals are used for generating certain stimulation parameters according to which the stimulation signals in each stimulation channel is generated. The analysis channels are linked to the stimulation channels via channel mapping. The number of stimulation channels may correspond to the number of analysis channels, or there may be more stimulation channels than analysis channels, or there may be more analysis channels than stimulation channels. Various stimulation strategies are used, such as current steering stimulation (in order to maximally excite a stimulation site located in between areas associated with two or more electrodes) and N-of-M stimulation (wherein stimulation current is only applied to N of M total stimulation channels during a particular stimulation frame).
[0009] An example for such a CI system with electrical cochlea stimulation is described in International Patent Application Publication WO 2011/032021 A1 and corresponding U.S. Pat. No. 8,422,706.
[0010] Typically, neural stimulation of the cochlea occurs by electric pulses applied via an electrode array implanted within the cochlea; alternatively or in addition neural stimulation of the cochlea may occur via light pulses or heat pulses applied within the cochlea.
[0011] For electric stimulation CI devices deliver trains of electrical pulses via an electrode array implanted within the cochlea which evoke neural responses in the auditory nerve. In present systems, pulse shapes are typically biphasic, with equal current amplitudes and durations of the positive and negative phase and with an optional gap in-between the two phases.
[0012] The basic functioning of the electrodes and integrity of electrode-nerve interface can be assessed by measurements of the auditory nerve response elicited by electrical stimulation. Electrically-evoked compound action potentials (ECAPs) can be recorded on the intracochlear electrodes and sent back to the implant external processor by back-telemetry. The ECAP is a voltage signal that comprises a negative and smaller positive peak; the typical order of magnitude of the ECAP is between 50 and 500 microvolts. To a first approximation, the ECAP magnitude is monotonically related to the amount of auditory nerve fibers that responded to the stimulus. Cochlear implant manufacturers have developed software tools to easily set stimulation and recording parameters and monitor the corresponding ECAP response. Examples of such neural response measurements are found in U.S. Pat. No. 7,282,877 B1. Another measure of the evoked neural activity is the auditory brain stem response (ABR) which may be recorded via external scalp electrodes.
[0013] The article “Efficiency analysis of waveform shape for electrical excitation of nerve fibers” by A. Wongsarnpigoo et al., in IEEE Trans Neural Syst Rehabil Eng 18(3), 2010, pages 319 to 328, relates to a study wherein, using a population model of mammalian axons and in vivo experiments on the cat sciatic nerve, the effects of waveform shape and duration on the charge, power and energy efficiency of neural stimulation were investigated.
[0014] U.S. Pat. No. 6,751,505 B1 relates to a CI system wherein the stimulation rate and the operation mode, including the staggering order of the pulses, are adjusted according to the neural response to the pulses which is measured in-situ by neural response telemetry utilizing the electrode array.
[0015] International Patent Application Publication WO 2010/150002 A1 and corresponding U.S. Patent Application Publication 2012/0130449 relate to a CI system wherein the wave shape of the pulses depends on the location of the electrode; it is mentioned that by varying the waveshape between its normal and inverted versions the effectiveness of the neural stimulation can be varied in location between a position close to the driven electrode and a position close to the reference electrode.
[0016] U.S. Pat. No. 6,219,580 B1 relates to a CI system comprising a pulse table for defining the stimulation pattern.
[0017] U.S. Pat. No. 7,974,697 B2 relates to an implantable neural stimulation device, wherein stimulation signal parameters are adjusted according to a brain map obtained by using a medical imaging device.
[0018] The article “Effects of waveform shape on human sensitivity to electrical stimulation of the inner ear” by A. van Wieringen et al., in Hearing Research 200 (2005), pages 73 to 86, relates to a study on how thresholds and dynamic ranges of CI users can be controlled by manipulating the way in which the charge produced by the initial phase of an electrical is recovered, wherein different types of pulses are investigated.
[0019] The article “Effect of electrical pulse shape on AVCN unit responses to cochlear stimulation” by J. A. Wiler et al., in Hearing Research 39 (1989), pages 251 to 262, relates to a study on the effect of electrical pulse shape on stimulation of guinea pig cochlea.
[0020] The article “Asymmetric pulses in cochlear implants: effects of pulse shape, polarity and rate” by O. Macherey et al., in JARO 7 (2006), pages 253 to 266 relates to a study on the perception effects of the shape, polarity and rate of asymmetric pulses.
[0021] The article “Forward-masking patterns produced by symmetric and asymmetric pulse shapes in electric hearing” by O. Macherey et al., in J. Acoust. Soc. Am. 127 (1), 2010, pages 326 to 338 relates to a study concerning forward-masking experiments with varying pulse shapes.
[0022] The article “The perceptual effects of inter phase gap duration in cochlear implant stimulation” by C. M. McKay at al., Hearing Research 181 (2003), pages 94 to 99 relates to a study on the effect of interphase gap duration on loudness perception.
SUMMARY OF THE INVENTION
[0023] It is an object of the invention to provide for a system for neural cochlear stimulation having a particularly low power consumption of the stimulation process; it is a further object to provide for a method of adjusting a device for neural cochlear stimulation.
[0024] According to the invention, these objects are achieved by a system as and a method as described herein.
[0025] The invention is beneficial in that, by applying test stimulation signals and measuring a response of the patient to the test stimulation signals in-situ, with the pulse shape parameter sets being evaluated according to the power consumption of the respective pulse and the stimulation response of the respective pulse, the pulse shape can be individually optimized with regard to power consumption and stimulation efficiency, so that the power consumption required for a given stimulation response can be minimized.
[0026] According to one embodiment, the programming unit is adapted to obtain for each shape parameter set under test an amplitude scaling factor required to evoke a predetermined response by the patient, wherein the amplitude scaling factor is used for evaluating the power consumption of the respective test pulse, i.e. that test shape parameter set is selected as the optimal test shape parameter set which results in the lowest amplitude scaling factor.
[0027] According to an alternative embodiment, the programming unit is adapted to provide the test shape parameters such that each test shape parameter set results in the same predetermined power consumption of the respective test pulse, wherein that test shape parameter set is selected as the optimal test shape parameter set which results in the largest stimulation response level.
[0028] Preferably, the patient specific response data are obtained from ECAP measurements. Preferably, the programming unit is adapted to supply and evaluate the test shape parameter sets in subsequent groups, wherein for each group the test shape parameter sets are scored, wherein the test shape parameter sets of each group are selected according to the evaluation result of the previous group of test shape parameter sets, and wherein that optimal test shape parameter set is selected for programming of the stimulation device which results in the best evaluation across all subsequent groups.
[0029] Hereinafter, examples of the invention will be described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a schematic representation of an example of a system according to the invention;
[0031] FIG. 2 is a schematic representation of an example of the CI device of the system of FIG. 1 ;
[0032] FIG. 3 is a schematic cross-sectional view of a human cochlea with marked stimulation sites;
[0033] FIG. 4 is a block diagram of an example of the signal processing structure of a CI device to be used with the present invention;
[0034] FIG. 5 is a flow chart of one example of the optimization procedure of the stimulation pulse shape according to the invention;
[0035] FIG. 6 is a flow chart of an alternative example of the optimization procedure of the stimulation pulse shape according to the invention;
[0036] FIG. 7 shows three different types of stimulation pulse shapes which may be used with the present invention; and
[0037] FIG. 8 is a schematic illustration of a setup for ECAP-measurements by reverse telemetry.
DETAILED DESCRIPTION OF THE INVENTION
[0038] FIG. 1 is a schematic representation of an example of a neural stimulation system according to the invention, comprising a programming unit 13 , which may be implemented as a computer, a programming interface 15 and a CI device 10 comprising a sound processing subsystem 11 and an implantable relation subsystem 12 , with the CI device being worn by a patient 17 . The programming unit 13 communicates with the sound processing subsystem 11 via the programming interface 15 , which may be implemented as a wired or wireless connection.
[0039] The programming unit 13 serves to control the sound processing subsystem 11 such that test stimulation signals are applied to the patient 17 via the stimulation subsystem 12 and to evaluate the test stimulation signals according to their power consumption and according to the stimulation response created by the test stimulation signals, with the stimulation response, according to a preferred embodiment, being measured by the CI device 10 . According to an alternative embodiment, the stimulation response may be measured by a physiological measuring device (indicated at 21 in FIG. 1 ) which may be provided in addition to the CI device 10 .
[0040] It is to be understood that the programming unit 13 is used with the CI device 10 only for adjustment/fitting, but not during normal operation of the CI device 10 .
[0041] In FIG. 2 an example of the cochlear implant device 10 of the system of FIG. 1 is shown schematically. The sound processing sub-system 11 serves to detect or sense an audio signal and divide the audio signal into a plurality of analysis channels, each containing a frequency domain signal (or simply “signal”) representative of a distinct frequency portion of the audio signal. A signal level value and a noise level value are determined for each analysis channel by analyzing the respective frequency domain signal, and a noise reduction gain parameter is determined for each analysis channel as a function of the signal level value and the noise level value of the respective analysis channel. Noise reduction is applied to the frequency domain signal according to the noise reduction gain parameters to generate a noise reduced frequency domain signal. Stimulation parameters are generated based on the noise reduced frequency domain signal and are transmitted to the stimulation sub-system 12 .
[0042] Stimulation sub-system 12 serves to generate and apply electrical stimulation (also referred to herein as “stimulation current” and/or “stimulation pulses”) to stimulation sites at the auditory nerve within the cochlear of a patient 17 in accordance with the stimulation parameters received from the sound processing sub-system 11 . Electrical stimulation is provided to the patient 17 via a CI stimulation assembly 18 comprising a plurality of stimulation channels, wherein various known stimulation strategies, such as current steering stimulation or N-of-M stimulation, may be utilized. In addition, the stimulation assembly 18 also may be used for ECAP measurements via reverse telemetry, as will be described in more detail with regard to FIG. 8 below.
[0043] As used herein, a “current steering stimulation strategy” is one in which weighted stimulation current is applied concurrently to two or more electrodes by an implantable cochlear stimulator in order to stimulate a stimulation site located in between areas associated with the two or more electrodes and thereby create a perception of a frequency in between the frequencies associated with the two or more electrodes, compensate for one or more disabled electrodes, and/or generate a target pitch that is outside a range of pitches associated with an array of electrodes.
[0044] As used herein, an “N-of-M stimulation strategy” is one in which stimulation current is only applied to N of M total stimulation channels during a particular stimulation frame, where N is less than M. An N-of-M stimulation strategy may be used to prevent irrelevant information contained within an audio signal from being presented to a CI user, achieve higher stimulation rates, minimize electrode interaction, and/or for any other reason as may serve a particular application.
[0045] The stimulation parameters may control various parameters of the electrical stimulation applied to a stimulation site including, but not limited to, frequency, pulse width, amplitude, waveform (e.g., square or sinusoidal), electrode polarity (i.e., anode-cathode assignment), location (i.e., which electrode pair or electrode group receives the stimulation current), burst pattern (e.g., burst on time and burst off time), duty cycle or burst repeat interval, spectral tilt, ramp on time, and ramp off time of the stimulation current that is applied to the stimulation site.
[0046] FIG. 3 illustrates a schematic structure of the human cochlea 200 . As shown in FIG. 3 , the cochlea 200 is in the shape of a spiral beginning at a base 202 and ending at an apex 204 . Within the cochlea 200 resides auditory nerve tissue 206 which is organized within the cochlea 200 in a tonotopic manner. Low frequencies are encoded at the apex 204 of the cochlea 200 while high frequencies are encoded at the base 202 . Hence, each location along the length of the cochlea 200 corresponds to a different perceived frequency. Stimulation subsystem 12 is configured to apply stimulation to different locations within the cochlea 200 (e.g., different locations along the auditory nerve tissue 206 ) to provide a sensation of hearing.
[0047] Returning to FIG. 2 , sound processing subsystem 11 and stimulation subsystem 12 is configured to operate in accordance with one or more control parameters. These control parameters may be configured to specify one or more stimulation parameters, operating parameters, and/or any other parameter as may serve a particular application. Exemplary control parameters include, but are not limited to, most comfortable current levels (“M levels”), threshold current levels (“T levels”), dynamic range parameters, channel acoustic gain parameters, front and backend dynamic range parameters, current steering parameters, amplitude values, pulse rate values, pulse width values, polarity values, filter characteristics, and/or any other control parameter as may serve a particular application.
[0048] In the example shown in FIG. 2 , the stimulation sub-system 12 comprises an implantable cochlear stimulator (“ICS”) 14 , a lead 16 and the stimulation assembly 18 disposed on the lead 16 . The stimulation assembly 18 comprises a plurality of “stimulation contacts” 19 for electrical stimulation of the auditory nerve. The lead 16 may be inserted within a duct of the cochlea in such a manner that the stimulation contacts 19 are in communication with one or more stimulation sites within the cochlea, i.e. the stimulation contacts 19 are adjacent to, in the general vicinity of, in close proximity to, directly next to, or directly on the respective stimulation site.
[0049] In the example shown in FIG. 2 , the sound processing sub-system 11 is designed as being located external to the patient 17 ; however, in alternative examples, at least one of the components of the sub-system 10 may be implantable.
[0050] In the example shown in FIG. 2 , the sound processing sub-system 11 comprises a microphone 20 which captures audio signals from ambient sound, a microphone link 22 , a sound processor 24 which receives audio signals from the microphone 20 via the link 22 , and a headpiece 26 having a coil 28 disposed therein. The sound processor 24 is configured to process the captured audio signals in accordance with a selected sound processing strategy to generate appropriate stimulation parameters for controlling the ICS 14 and may include, or be implemented within, a behind-the-ear (BTE) unit or a portable speech processor (“PSP”). In the example of FIG. 2 the sound processor 24 is configured to transcutaneously transmit data (in particular data representative of one or more stimulation parameters) to the ICS 14 via a wireless transcutaneous communication link 30 . The headpiece 26 may be affixed to the patient's head and positioned such that the coil 28 is communicatively coupled to the corresponding coil (not shown) included within the ICS 14 in order to establish the link 30 . The link 30 may include a bidirectional communication link and/or one or more dedicated unidirectional communication links. According to an alternative embodiment, the sound processor 24 and the ICS 14 may be directly connected by wires.
[0051] In FIG. 4 , a schematic example of a sound processor 24 is shown. The audio signals captured by the microphone 20 are amplified in an audio front end circuitry 32 , with the amplified audio signal being converted to a digital signal by an analog-to-digital converter 34 . The resulting digital signal is then subjected to automatic gain control using a suitable automatic gain control (AGC) unit 36 .
[0052] After appropriate automatic gain control, the digital signal is subjected to a filter bank 38 comprising a plurality of filters F 1 . . . Fm (for example, band-pass filters) which are configured to divide the digital signal into m analysis channels 40 , each containing a signal representative of a distinct frequency portion of the audio signal sensed by the microphone 20 . For example, such frequency filtering may be implemented by applying a Discrete Fourier Transform to the audio signal and then divide the resulting frequency bins into the analysis channels 40 .
[0053] The signals within each analysis channel 40 are input into an envelope detector 42 in order to determine the amount of energy contained within each of the signals within the analysis channels 40 and to estimate the noise within each channel. After envelope detection the signals within the analysis channels 40 are input into a noise reduction module 44 , wherein the signals are treated in a manner so as to reduce noise in the signal in order to enhance, for example, the intelligibility of speech by the patient. Examples of the noise reduction module 44 are described in International Patent Application Publication WO 2011/032021 A1 and corresponding U.S. Pat. No. 8,422,706.
[0054] The noise reduced signals are supplied to a mapping module 46 which serves to map the signals in the analysis channels 40 to the stimulation channels S 1 . . . Sn. For example, signal levels of the noise reduced signals may be mapped to amplitude values used to define the electrical stimulation pulses that are applied to the patient 17 by the ICS 14 via M stimulation channels 52 . For example, each of the m stimulation channels 52 may be associated to one of the stimulation contacts 19 or to a group of the stimulation contacts 19 .
[0055] The sound processor 24 further comprises a stimulation strategy module 48 which serves to generate one or more stimulation parameters based on the noise reduced signals and in accordance with a certain stimulation strategy (which may be selected from a plurality of stimulation strategies). For example, stimulation strategy module 48 may generate stimulation parameters which direct the ICS 14 to generate and concurrently apply weighted stimulation current via a plurality 52 of the stimulation channels S 1 . . . Sn in order to effectuate a current steering stimulation strategy. Additionally or alternatively the stimulation strategy module 48 may be configured to generate stimulation parameters which direct the ICS 14 to apply electrical stimulation via only a subset N of the stimulation channels 52 in order to effectuate an N-of-M stimulation strategy.
[0056] The sound processor 24 also comprises a multiplexer 50 which serves to serialize the stimulation parameters generated by the stimulation strategy module 48 so that they can be transmitted to the ICS 14 via the communication link 30 , i.e. via the coil 28 .
[0057] The sound processor 24 may operate in accordance with at least one control parameter which is set by a control unit 54 . Such control parameters may be the most comfortable listening current levels (MCL), also referred to as “M levels”, threshold current levels (also referred to as “T levels”), dynamic range parameters, channel acoustic gain parameters, front and back end dynamic range parameters, current steering parameters, amplitude values, pulse rate values, pulse width values, polarity values and/or filter characteristics. Examples of such auditory prosthesis devices, as described so far, can be found, for example, in International Patent Application Publication WO 2011/032021 A1 and corresponding U.S. Pat. No. 8,422,706.
[0058] The stimulation strategy module 48 also controls the shape of the stimulation pulses. In general, the pulse shape is determined by a shape parameter set including at least one shape parameter. Such shape parameter set may be stored in a memory 56 .
[0059] Examples of different types of pulse shapes are shown in FIG. 7 . The left-hand example in FIG. 7 shows an asymmetric biphasic pulse which may be described, for example by the following parameters: duration of the negative phase (d 1 ), amplitude of the negative phase (a 1 ), duration of the positive phase (d 2 ), amplitude of the positive phase (a 2 ), and duration of the interphase gap (d g ).
[0060] While the example shown at the left-hand of FIG. 7 is a staircase pulse, other parameterizations are also conceivable. For example, the pulse shape could be described in terms of an arbitrary set of basic functions, such as a sum of exponential-shaped pulses (see center of FIG. 7 , wherein the pulse is parameterized by the peak amplitudes (a 1 , a 2 , a 3 , a 4 ) of four exponentials different fixed decay rates) or Gaussian shaped pulses (see right-hand of FIG. 7 , wherein the pulse is parameterized by the peak times (t 1 , t 2 ), amplitudes (a 1 , a 2 ) and pulse widths (w 1 , w 2 ) of two Gaussian-shaped pulses). The motivation for such different representation could be two-fold. Firstly, an appropriate set of basic functions can provide for a more parsimonious representation of complex analog or quasi-analog pulse shapes than a finely sampled staircase. Hence, the number of optimization parameters and the time required for the optimization may be reduced, even if the idealized analog shape is finally delivered approximately as a staircase pattern by the CI implant electronics (as it is presently typically the case). Secondly, more advanced CI devices may not be restricted to staircase stimulation patterns but may even use current sources which physically generate non-rectangular pulses themselves.
[0061] The programming unit 13 is connected to the CI device 10 via the programming interface 15 for programming the CI device in a manner so as to optimize the pulse shape with regard to power consumption. To this end, the programming unit 13 may communicate with the control unit 54 in order to make the CI device 10 subsequently apply test stimulation signals having pulses of different test shapes defined by a plurality of different test shape parameter sets. For example, the test shape parameter sets may implement systematic variations of the duration and amplitude of the negative and positive phase and the interphase gap duration.
[0062] Further, the programming unit 13 determines the power consumption for evaluation of the respective test pulses.
[0063] In addition, the stimulation response to each test pulse is measured and the respective stimulation response data is supplied to the programming unit 13 for evaluating each test pulse width regard to that stimulation response. According to a preferred embodiment, the stimulation response data is obtained from ECAPs measurements carried out by the CI device 10 , with the evoked potential data being recorded by reverse telemetry from the ICS 14 to the sound processing subsystem 11 , from where the data is supplied via the programming interface 15 to the programming unit 13 (this path is schematically indicated at 58 in FIG. 4 ).
[0064] FIG. 8 shows a schematic illustration of an example of auditory nerve excitation and the resulting ECAP recording at electrode 18 A by reverse telemetry, following electrical stimulation at electrode 18 B by forward telemetry (the stimulated neurons are indicated by dark grey circles in FIG. 8 , the return electrodes are indicated at 18 C and 18 D, respectively). The current-source 60 and the amplifiers 62 are positioned inside the receiver part of the ICS 14 . The typical ECAP peaks are indicated at N 1 and P 1 in example of an ECAP signal vs. time in FIG. 8 . The peaks may be used as markers to measure the ECAP amplitude as the differential voltage between P 1 and N 1 .
[0065] Alternatively, stimulation response data may be obtained by a scalp recording electrode or any other known means of recording neural responses. In particular, stimulation response data may be obtained from auditory brain stem response (ABR) measurements, electrically evoked stapedius reflex measurements, post-auricular muscle reflex measurements, cortical potential measurements or iris contraction measurements. According to further alternative embodiments, the stimulation response data may be obtained from EEG (electro-encephalography), MEG (magneto-encephalography) or functional imaging measurements. According to a still further embodiment, stimulation response data may be obtained from psychophysical measurements, such as detection threshold measurements or loudness ratings, which, however, involve active participation of the patient, limiting this approach in practice to adult patients only.
[0066] According to one example, which is schematically shown in FIG. 5 , for each test shape parameter set a minimum amplitude scaling factor required to evoke a given response is obtained from the response measurement. Typically, the given neural response will be a neural response threshold. Rather than directly measuring the response, an indirect estimate or a related measure thereof, such as tNRI (neural response imaging) levels derived from ECAPs measurements (cf., for example “Comparisons between neural response imaging thresholds, electrically evoked auditory reflex thresholds and most comfortable loudness levels in CII bionic ear users with HiResolution sound processing strategies”, by D. M. Han et al., in Acta Otolaryngol 125(7), 2005, p. 732-735) may be determined.
[0067] The investigated test shape parameter sets then may be scored and ranked according to the power consumption required for generating the respective test pulse. According to a more elaborate scoring scheme, in addition a cost function could be used which incorporates additional penalties for various undesirable properties of the pulse shape, such as stimulation near the compliance voltage of the implant, or excessive total pulse duration.
[0068] Preferably, the test shape parameter sets are iteratively evaluated in subsequent groups, wherein the optimal test shape parameter set, i.e., the parameter set having been awarded the best evaluation across all groups, is finally used for programming the CI device 10 . According to such iterative method, a first group of n test parameter sets is investigated, and after investigation of the first group a second group of n parameter sets is defined based on the scoring results obtained for the first group of parameter sets, the second group is investigated, and so on, until a stopping criterion is reached. Such stopping criterion may be the lapse of a given time period since the start of the optimization procedure, or the iteration may be stopped when for a given time period no test shape parameter set has been found having a better evaluation than the already evaluated test shape parameter sets.
[0069] One benefit of group-wise iteration is that it thereby may be avoided that the optimization process halts prematurely after having reached a particular local maximum of the scoring function.
[0070] An alternative optimization procedure is illustrated in FIG. 6 , wherein the test shape parameter sets are provided such that each test shape parameter set results in the same predetermined power consumption of the respective test pulse. In this case the test shape parameter sets are scored according to the magnitude of the stimulation response level, i.e. the test parameter set resulting in the highest stimulation response level will receive the highest score.
[0071] While in the example of FIG. 5 , the measuring system has to return threshold stimulus amplitudes, it has to return response amplitudes in the example of FIG. 6 . A priori, one may expect that the procedure of FIG. 5 is slower than the procedure of FIG. 6 on each iteration cycle, since the determination of a response threshold requires taking repeated measurements at various stimulus amplitudes. However, the procedure of FIG. 6 may be prone to greater intrinsic variability due to the fact that stimulation is not targeted at a constant criterion response level as in the procedure of FIG. 5 .
[0072] In any case, the optimization procedure serves to determine the optimal pulse shape parameter set which is to be stored in the memory 56 for operation of the CI device 10 .
[0073] Preferably, the optimal test shape parameter set is determined for each stimulation channel separately, with test pulses being applied only to one stimulation channel at a time. In general, the CI device 10 may be designed for electrical stimulation of the cochlea only, for stimulation of the cochlea with light, for the stimulation of the cochlea with heat, or combinations of such stimuli.
[0074] By optimizing the stimulation pulse shape, the present invention helps to reduce power consumption of the implant, thereby prolonging battery life and/or allowing for smaller speech processor designs. This is important in view of the fact that size and weight of external components are major criteria for the comfort, usability and esthetic appeal of a CI device to a patient. | A system having a device for neural stimulation of a patient's cochlea, an in-situ device for measuring a patient's response to the neural stimulation of the cochlea, and a programming unit for adjusting the stimulation device; the stimulation device having a stimulation signal unit for generating a stimulation signal formed of pulses having a shape determined by a shape parameter set including at least one shape parameter; a cochlear implant stimulation arrangement with a plurality of stimulation channels for stimulating the cochlea based on the stimulation signal; the measuring device providing patient-specific response data concerning the stimulation response to a programming unit that controls the stimulation signal unit by subsequently supplying a plurality of different test shape parameter sets to the stimulation signal unit for causing the stimulation signal unit to generate corresponding test pulses, the programming unit evaluating each test shape parameter set based on stimulation response data. | 0 |
RELATED APPLICATION
[0001] This application is a divisional of co-pending a U.S. patent application having Ser. No. 12/650,499, filed 30 Dec. 2009, which is incorporated by reference herein.
TECHNICAL FIELD
[0002] The present application relates to devices for injecting lift gas into a production conduit of an oil well via one or more gas lift flow control devices and to a gas lift flow control device for use in the method.
BACKGROUND
[0003] Lift gas can be pumped into an annulus between a production tubing and surrounding well casing and subsequently into the production tubing from the annulus via one or more one way gas lift flow control devices in side pockets that are distributed along the length of the production tubing. The lift gas which is injected through the flow control devices into the crude oil (or other fluid) stream in the production conduit reduces the density of the fluid column in the production conduit and enhances the crude oil production rate of the well.
[0004] Gas lift flow control devices can use one way check valves which comprise a flapper type valve that presses against a seating. They can also include a ball or hemisphere or cone which is pressed against a valve seating ring by a spring. If the lift gas pressure is higher than the pressure of the crude oil stream in the production conduit then this pressure difference exceeds the forces exerted to the check valve by the spring so that the spring is compressed and the valve is opened and lift gas is permitted to flow from the gas filled injection conduit into the production conduit. If however the pressure of the crude oil stream is higher than the lift gas pressure in the injection conduit, the accumulated forces of the spring and the pressure difference across the gas lift flow control device closes the check valve and prevents crude oil, or other fluid, to flow from the production conduit into the injection conduit.
[0005] Issues exist relating to integrity of the sealing function of the one way valve, particularly across a wide range of pressure differentials, e.g., zero to high pressure differential. Also, issues exist with degradation of the seals through exposure to flow of gas and well fluids for various reasons, e.g., debris in the flow.
[0006] Accordingly, it is desirable to improve the sealing of the one way valve, and also to protect the integrity of the sealing components during flow of the gas and operation in general.
SUMMARY
[0007] A preferred embodiment includes a gas lift valve that has a longitudinally extending tubular body having an inlet and an outlet, a flow path extending between the inlet and the outlet, and a flow tube located inside the body. The flow tube is translatable in the axial direction between at least a first and a second position. A venturi orifice is located inside the body along the flow path. A seal part is located proximate to the outlet of the body. A flapper is connected with the body by way of a hinge part and the flapper has at least a first open position and a second closed position. The closed position is where the flapper contacts the seal thereby closing the flowpath and the second closed position is where the flapper does not contact the seal and does not close the flowpath.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The following is a brief description of figures herein showing some preferred embodiments of various designs.
[0009] FIG. 1 shows a side section view of an embodiment.
[0010] FIG. 2 shows a side section view of an embodiment.
[0011] FIG. 3 shows a side section view of an embodiment.
[0012] FIG. 4 shows a side section view of an embodiment.
[0013] FIG. 5 shows a side section view of an embodiment.
[0014] FIG. 6 shows a side section view of an embodiment.
[0015] FIG. 7 shows a side section view of an embodiment.
DETAILED DESCRIPTION
[0016] In the following description, numerous details are set forth to provide an understanding of the present embodiments. However, it will be understood by those skilled in the art that the present embodiments may be practiced without many of these details and that numerous variations or modifications from the described embodiments are possible.
[0017] As used here, the terms “above” and “below”; “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or diagonal relationship as appropriate.
[0018] FIG. 1 shows a side view of various features. A gas lift valve has a body 5 that contains and supports various parts of the device. A flow tube 4 is located inside the body 5 . The body 5 can be a generally tubular shape. The flow tube 4 is a hollow tubular shape and can be translatable along an axial direction within the body 5 . A flapper valve 1 is connected with the body 5 by way of a hinge part 7 . The flapper valve 1 seals an opening leading into a portion of the body 5 that houses the flow tube 4 . The flow tube 4 is translatable and has at least two distinct positions. In one position the flow tube 4 is retracted and does not extend though the opening defined by a seal part 2 . In another position, the flow tube 4 extends though the opening defined by the seal part 2 . The seal part 2 and the flapper 1 contact one another and together close the opening defined by the seal part 2 . In other words, the flapper 1 seats itself with the seal part 2 thereby closing the opening. This configuration is effectively a one way valve as flow cannot occur is a direction into the flow tube 4 . The hinge part 7 connected with the flapper 1 can include a spring that biases the flapper 1 into the closed position covering the opening defined by the seal part 2 .
[0019] A purpose of the flow tube 4 is to protect the seal part 2 . According to embodiments, when in use the gas lift valve is located in a conduit connecting a well annulus with an internal production tube. The gas lift valve is located in a side pocket of the production tubing that connects the annulus with the interior of the production tubing. Gas is forced into the annulus and when a proper pressure is reached, the gas travels from the annulus, through the gas lift valve, and into the production tubing. As is apparent from FIG. 1 , the gas travels through the flow tube 4 , out the opening defined by the seal 2 , and into the annulus. Accordingly, as the flow tube 4 is extended when the flow occurs, any debris in the flow is shielded from the seal part 2 , thereby maintaining the integrity of the seal part 2 and allowing for a longer life.
[0020] The seal part 2 can be made up of a hard metal portion 18 and at least one softer spring or elastomeric portion 19 . Additionally, the seal part 2 can have a self aligning feature. In FIG. 1 , elastic elements 17 contact and support the hard metal portion to help align the hard metal portion 19 with the flapper 1 when the flapper 1 is in the closed position as shown in FIG. 1 .
[0021] FIG. 2 shows an embodiment and includes a venturi style restriction 9 . The body 5 has passages 8 where the gas from the annulus enters the body 5 . The flow tube 4 and the body 5 are connected by way of a spring 10 that biases the flow tube 4 into the retracted position. Also, the flapper 1 can be biased toward the closed position. Accordingly, there is a need to force the flow tube into the extended position upon application of the gas in the annulus. According to the present application, there are a number of embodiments that accomplish that goal.
[0022] In FIG. 2 , a blunt body is located at the end of the flow tube 4 . The blunt body is in the flowpath and thereby forces the flow tube 4 into the extended position during flow of the gas. The blunt body can be any part that impinges the flow and transfers force from the flow to the flow tube 4 . The extension of the flow tube 4 and the gas opens the flapper 1 . As the flow tube 4 extends during flow of the gas the seal part 2 is protected.
[0023] FIG. 3 shows embodied features according to the present application. A pressure tap 11 connects the outside of the body 5 in the annulus with a passage that is adjacent to and connects with the flow tube 4 . Upon application of pressure in the pressure tap 11 , the flow tube 4 is forced into an extended position through the opening defined by the seal 2 , thereby protecting the seal 2 during flow of the gas. Also, the flapper 1 is forced open.
[0024] FIG. 5 shows an embodiment where the venturi flow restrictor 9 is connected with the flow tube 4 . As gas flows through the venturi 9 , force is created by way of the pressure drop across the venturi that forces the flow tube 4 into an extended position. FIG. 5 shows the flow tube 4 in an extended position through the opening defined by the seal 2 where the flapper 1 is open.
[0025] FIG. 6 shows an embodiment including a nose profile 12 that is connected with the body 5 . The nose profile 12 helps deploy and locate the gas lift valve in a pocket of the production tubing. The nose profile 12 is generally a contoured or pointed part in that regard. A hole can be present in nose profile 12 so that the flapper can fully open. Absent the hole, the flapper 1 would likely contact the nose profile 12 and not open fully. An aspect of the present application is the nose profile 12 being made from a degradable material that will dissolve relatively quickly in a well environment. If the nose profile 12 dissolves quickly enough, there is no need for a hole to accommodate the opening of the flapper 12 .
[0026] FIG. 7 is a close up view of an embodiment of the seal part 2 . According to this embodiment, the seal part 2 has three components. The first component is a hard seat 18 made from metal. Under high pressure differential the metal seat 18 will contact the flapper 1 and form a seal. The second component is a PEEK/Teflon seat 15 . Under a pressure lower than the high pressure, the PEEK/Teflon seat 15 will form the primary seal. The third component is an elastomeric seat 16 . The elastomeric seat 16 forms the primary seat when lower or no pressure differential is experienced. In other words, as the pressure differential increases, the various seats are compressed to different degrees and as the pressure gets higher, different components form the primary seal.
[0027] The embodiments described herein are merely examples of various preferred designs and are not meant in any way to unduly limit the scope of any presently recited or subsequently related claims. | A gas lift valve can include a degradable component; a valve; and a longitudinally extending tubular body that defines a flow path therein that includes the valve disposed between the degradable component and an opening of the tubular body. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/581,547, filed Dec. 23, 2014, which is a continuation-in-part application of U.S. patent application Ser. No. 14/359,890, entitled “Treatment of Urinary Incontinence,” filed May 21, 2014, which claims priority to international patent application PCT/US2012/066613, filed Nov. 27, 2012, and U.S. provisional Patent Application No. 61/563,889, filed Nov. 28, 2011, the entireties of which are incorporated herein by reference for all purposes.
BACKGROUND
[0002] The present embodiments relate to the devices, diagnosis, and treatment of fecal incontinence in females and males. The diagnosis and treatment may involve the use of a multiple sensor-enabled catheter capable of providing real-time data regarding the patient's anatomy and physiology, such as muscular function of the pelvic floor and rectal sphincter, as well as the position and movement of the catheter within the patient.
[0003] Fecal incontinence refers to the involuntary loss of gas or liquid stool (called minor incontinence) or the involuntary loss of solid stool (called major incontinence). An estimated 6.5 million Americans suffer with fecal incontinence, but the number of patients suffering from this condition is likely under-reported due to the embarrassment associated with the malady. The percentage of affected females is higher than males because of trauma to the pelvic floor musculature experienced during parturition. More specifically, female fecal incontinence can be caused by sphincter damage at the time of childbirth, injury to the muscles of the pelvic floor, or the innervation of these tissues. These injuries increase in direct proportion to the number of deliveries, the weight of the baby, and the number of operative deliveries. Cesarean section decreases the incidence of fecal incontinence in females, but carries the risks and complications of surgery. Other reasons for fecal incontinence in both females and males include constipation, chronic diarrhea, old age, depression, urinary incontinence, systemic diseases such as Irritable Bowel Syndrome (IBS), and problems involving the nervous system such as stroke, spinal cord injury, multiple sclerosis, and Parkinson's disease.
[0004] Current medical diagnostic tests for fecal incontinence include direct examination, anorectal manometry, sensory testing, anal endosonography, defecography, ultrasound, magnetic resonance imaging (MRI), pudenal nerve terminal latency (PNTML), and stool tests. Current treatments for fecal incontinence may involve changes in diet, pelvic floor muscle training (PFMT), medical therapy, and surgical correction.
[0005] PFMT (or Kegel) exercises includes a series of exercises designed to rehabilitate the musculature of the pelvic floor. For example, PFMT can help strengthen and tone the muscles under the uterus, bladder, and bowel (large intestine), and thus aid those who have problems with bowel control or rectal sphincter function. A current problem with PFMT, however, is that the individual is often unable to visualize or attain the proper muscle position and control to carry out an efficient and effective exercise regimen required to rehabilitate the pelvic floor muscles.
SUMMARY
[0006] The embodiments described herein relate to the diagnosis and treatment of fecal incontinence in females and males. In one embodiment, diagnosis and treatment involves the use of a probe device capable of providing real-time data regarding a patient's anatomy and physiology; such as muscular function of the rectal sphincter or pelvic floor, as well as the position or movement of the device within the patient. In one embodiment, the device may be a pressure sensor-enabled catheter.
[0007] In one embodiment, the multiple sensor-enabled catheter may include at least one sensor capable of providing real-time data of one or more types selected from the group consisting of position, movement, pressure, and flow. In this regard, a sensor may have a single measurement and reporting capability, or may have multiple measurement and reporting capabilities.
[0008] The present embodiments also provide for methods for the diagnosis or treatment of fecal incontinence in females and males, comprising positioning a multiple sensor-enabled catheter in a patient's rectum and determining the anatomical state of the patient, which treatment is capable of relieving or ameliorating incontinence. The anatomical state may be the sphincteric or supportive functions of the pelvic floor, such as muscle tone and strength. The method of diagnosis or treatment may also include manipulating the patient to relieve the fecal incontinence. The manipulation may be performed by the health care provider or the patient. The manipulation may include achieving a particular anatomical position of the patient's internal organs to achieve a particular muscular function of the pelvic floor.
[0009] The present embodiments contemplate the real-time position and movement tracking as described in U.S. Pat. No. 8,805,472. In this regard, the real-time position and movement tracking may include sensing the position of a fixed reference point(s) within the subject's body, by providing a catheter enabled with a sensor and capable of providing positional or movement data that can be perceived by a device, person, health care provider, or patient. The fixed reference point within the patient's body may be the pubic bone, the coccyx, the bladder, the urethra, the uterus, the prostate, or the rectum. The method may be performed in real-time, for example, during an operation. In another embodiment, the method may be performed at multiple time intervals. The multiple time intervals may occur, for example, pre- and post-event, wherein the event may be parturition, injury, or surgery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 depicts a view of an example probe device comprising a multiple sensor-enabled catheter.
DETAILED DESCRIPTION
[0011] All patents, applications, and other publications identified are expressly incorporated herein by reference for the purpose of describing and disclosing, for example, the devices methodologies described in such publications that might be used in connection with the present invention. These publications are provided solely for their disclosure prior to the filing date of the present application. Nothing in this regard should be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention or for any other reason. All statements as to the date or representation as to the contents of these documents are based on the information available to the applicants and does not constitute any admission as to the correctness of the dates or contents of these documents.
[0012] As used herein and in the claims, the singular forms include the plural reference and vice versa unless clearly indicated otherwise by context. Throughout this specification and claims, unless otherwise indicated, “comprise,” “comprises” and “comprising” are used inclusively rather than exclusively. The term “or” is inclusive unless modified, for example, by “either.” Other than in the operating examples, or where otherwise indicated, all numbers should be understood as modified in all instances by the term “about.”
[0013] Unless otherwise defined, scientific and technical terms used herein shall have the meanings that are commonly understood by those of skill in the art. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention, which is defined solely by the claims.
[0014] One embodiment described herein provides for methods for the diagnosis or treatment of fecal incontinence in females and males, comprising positioning in the rectum of a patient a multiple sensor-enabled catheter, visualizing the anatomical state of the patient, and manipulating the patient's body to a position capable of relieving the fecal incontinence. In an additional embodiment, the anatomical state is the relative position of one or more internal anatomical reference points selected from the pubic bone, the coccyx, the bladder, the urethra, the uterus, the prostate, or the rectum. In another embodiment, the anatomical state is the muscular function of the rectal sphincter.
[0015] An additional embodiment provides for a method of rehabilitating the pelvic floor musculature, comprising positioning in the rectum of a patient a multiple sensor-enabled catheter and visualizing the anatomical state of the patient, wherein the patient manipulates the catheter as a method of exercising control of sphincter or pelvic floor muscles.
[0016] In the present embodiments, for example, a catheter is enabled with at least one sensor capable of providing real-time data of at least one data type selected from the group consisting of position, movement, pressure, and flow. In this regard, a sensor may have a single measurement and reporting capability, or may have multiple measurement and reporting capabilities. The data obtained by the multiple sensor-enabled catheter may be reported in any number of ways know in the art, including the transmission to, and visualization on, a graphical user interface. For purposes of the embodiments, “real-time” may include instantaneous as well as delayed observation, reporting, or recording of an event as it elapses.
[0017] Advantageously, by viewing a real-time image of where one or more fixed anatomical reference points are located relative to one another during a procedure, a health care provider may manipulate the patient such that the patient is in a position capable of relieving or ameliorating fecal incontinence. In other instances, a patient may visualize her or his own anatomical state using the multiple sensor-enabled catheter, and may manipulate her or his body such that she or he is in a position capable of relieving fecal incontinence. Additionally or alternatively, the patient may visualize her or his own anatomical state using the multiple sensor-enabled catheter, and may manipulate her or his body to a position capable of controlling her or his pelvic floor muscles to relieve fecal incontinence.
[0018] A multiple sensor-enabled catheter provides a valuable study or diagnostic tool for a health care provider as well as a patient, particularly when the patient is considering surgery that may result in fecal incontinence as a post-surgical complication (e.g., from colorectal or prostate surgery). For example, a health care provider may provide the patient with an in-office procedure that determines a baseline position or relative mobilization of the an anatomical reference point within the patient's body (baseline) before possible damage to her or his pelvic floor; such that if surgical repair is subsequently performed, the bladder can be repositioned to the original, pre-incontinence anatomic position. Surgery could also be performed on patients with a surgically correctable structural defect, using the multiple sensor-enabled catheter to provide positioning data. Such procedures may involve a pelvic sling or other surgical intervention.
[0019] A multiple sensor-enabled catheter also provides a valuable study or diagnostic tool for a health care provider as well as a female patient pre- or post-childbirth. For example, a health care provider may provide a patient with an in-office procedure that determines a baseline position or relative mobilization of the an anatomical reference point within the patient's body (baseline) before possible damage to her pelvic floor, particularly injuries that result in pelvic organ prolapse; such that if surgical repair is subsequently performed, the bladder or prolapsed organs can be repositioned to the original, pre-incontinence anatomic position. With a female patient, another embodiment may involve a multiple sensor-enabled catheter inserted in the rectum and another multiple sensor-enabled catheter inserted in the vagina or urethra to provide additional positional or pressure data.
[0020] A multiple sensor-enabled catheter may incorporate at least one sensor capable of measuring or reporting data of various types, including position, movement, pressure, or flow. A multiple sensor-enabled catheter with more than one individual sensor may be arrayed as depicted in FIG. 1 , or it may incorporate a single sensor that has multiple measurement and reporting capabilities.
[0021] The position or movement data may be of the sort measured or reported by any number of sensor devices, including accelerometer, gyroscope, inductive non-contact position sensor, string potentiometer, linear variable differential transformer, potentiometer, capacitive transducer, Eddy-current sensor, Hall effect sensor, optical proximity sensor, piezo-electric transducer, or photodiode array sensor devices. The position or movement data may also include magnetic, electromagnetic, microelectromechanical, radio frequency, ultrasound, or video data.
[0022] The pressure or flow data may be of the sort measured or reported by any number of sensor devices, including force collector types, such as piezo-resistive, capacitive, electromagnetic, piezo-electric, optical, potentiometric, or other types, such as resonant, thermal, ionization, ultrasonic, or density (mass and index of refraction) sensor devices.
[0023] For example, an embodiment of a multiple sensor enabled catheter comprising a firm tip, which may be about ½ inch in length to guide the catheter through the rectum. The catheter may be a Foley catheter. The number and precise placement of an individual sensor may vary depending on the type of positional, movement, pressure or flow measurement or reporting system employed. An individual sensor may have a single function or be multifunction (such as positional tracking combined with pressure and flow sensing). The multiple sensor-enabled catheter may also embody a video observation or recording device as well as an illumination source to facilitate such video capture. The precise placement of the sensor(s) and video capture component(s) are not pre-defined, and may be configured according to the requirements of the desired application.
EXAMPLES
[0024] As described herein, catheters useful in the present embodiments may embody at least one sensor capable of measuring and reporting at least one data type, including position, movement, pressure, and flow. These include, but are not limited to, magnetic, electromagnetic, microelectromechanical, radio frequency, ultrasound, and video. One example of a multiple sensor-enabled catheter, as shown in FIG. 1 , is a probe or catheter 100 containing multiple sensors arranged in an array 102 . The probe or catheter 100 may be constructed of a silicon or other material suitable for medical use in or on a patient's body. The probe or catheter 100 may include a distal probe or catheter tip 101 , which may be constructed of a material with sufficient hardness or rigidity to facilitate the ease of insertion of the probe or catheter 100 into a patient's rectum. The probe or catheter 100 may also contain a proximal portion with a connector/handle 104 to facilitate positioning or movement of the probe or catheter 100 by the patient or health care provider. A sensor, such as a pressure sensor 103 , may be contained in the proximal portion of the probe or catheter 100 to facilitate the assessment of rectal sphincter strength and/or control when the probe or catheter 100 is inserted into the patient's rectum.
[0025] In other embodiments, the sensor(s) may be positioned in the probe or catheter 100 without a particular spatial relationship to any other sensor(s). The probe or catheter 100 may contain a microelectromechanical (MEMS) device(s), a 3-axis accelerometer, a roll/pitch gyroscope and a yaw rate gyroscope, and a pressure and flow transducer. The devices may also be mounted on a small flexible printed circuit board (PCB) and then attached to the probe or catheter. The 3-axis accelerometer may track translation of the probe or catheter in three directions. The gyroscopes are utilized to account for gravitational rotation, allowing real-time movement to be tracked.
[0026] In one embodiment, a PCB may be prepared with the three MEMS devices mounted thereon. Soft leads trail the MEMS devices to supporting devices, including, for example, a data acquisition card which may be used for transforming analog signals to digital signals. The PCB is set within the wall of the probe or catheter. The location of the probe or catheter may be determined by the output signals of the MEMS devices.
[0027] The multiple sensor enabled catheter may be linked via data cable 105 to a transmitter 106 , which can provide a wireless data signal (such as Bluetooth) to a device 107 (computer, tablet, smartphone, or similar device) capable of receiving the transmission of data collected by the sensors. The connection of the data cable 105 to the catheter or probe 100 may be achieved through a mating interface with connector/handle 104 . Alternatively, the transmitter may be contained within the probe/catheter or the probe/catheter handle. The linked device 107 may process the data or provide a graphical user display, or transmit such information to another device(s) to accomplish similar tasks. In another embodiment, the probe or catheter 100 may transmit a wireless data signal directly to the device 107 .
[0028] The patient may be asked to recreate maneuvers that induce fecal incontinence at the same time that the parameters for the location/pressure/flow/visualization of the anatomical reference point(s) are determined.
[0029] The patient's body (and the anatomical reference point(s)) may be manipulated to the position where rectal sphincter pressure is optimized and fecal continence is improved or restored to normal. These anatomical reference point positions may be displayed in real-time on a graphical user interface or recorded. The patient's body may be manipulated by a health care provider, or by the patient as described herein.
[0030] In the case of surgical intervention, if no pre-incontinence position is known, the patient's body (and the anatomical reference point(s)) may be positioned based on data collected from a cohort of patients with a similar fecal incontinence history or profile. Where pre-incontinence data is available (e.g., the positions of particular anatomical reference points are based on patient information from an earlier date), then at the time of surgery the corresponding anatomical reference points are repositioned to the location where the patient was previously fecally continent.
[0031] Following examination using the multiple sensor-enabled catheter, a health care provider may conclude that rehabilitation is an efficacious option for treating a patient's fecal incontinence. In this regard, the measurements provided by the multiple sensor-enabled catheter may be recorded to facilitate appropriate patient instructions on performing Kegel exercises in an optimal manner using the visual (on-screen) information provided by the catheter in real-time. Once engaging the proper musculature has been communicated successfully to a patient during a medical office visit, the patient may be sent home with the instructions to perform Kegel exercises five to six times daily, for example. Four to six weeks later, the patient may return for another examination using the multiple sensor-enabled catheter to evaluate rehabilitative treatment effectiveness, which may allow a health care provider to advise the patient about the prospects for restoring complete fecal continence with a continued rehabilitation regime or a surgical procedure.
[0032] Detailed embodiments are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the claimed invention that may be embodied in various forms. It will be appreciated that many modifications and other variations that will be appreciated by those skilled in the art are within the intended scope of this invention as claimed below without departing from the teachings, spirit, and intended scope of the invention. | Methods and devices to diagnose and treat fecal incontinence in females and males are provided. A multiple sensor-enabled catheter for positioning in a patient's rectum allows for the visualization and manipulation or positioning of an anatomical reference point(s) in the patient's body. A multiple sensor-enabled catheter for rectal insertion in a patient allows for the visualization and implementation of efficient and effective exercises to strengthen pelvic floor muscles. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. Ser. No. 09/179,507, filed Oct. 27, 1998.
BACKGROUND
[0002] The invention relates to addressable downhole activation systems.
[0003] To complete a well, one or more sets of perforations may be created downhole using perforating guns. Such perforations allow fluid from producing zones to flow into the wellbore for production to the surface. To create perforations in multiple reservoirs or in multiple sections of a reservoir, multi-gun strings are typically used. A multi-gun string may be lowered to a first position to fire a first gun or bank of guns, then moved to a second position to fire a second gun or bank of guns, and so forth.
[0004] Selectable switches are used to control the firing sequence of the guns in the string. Simple devices include dual diode switches for two-gun systems and concussion actuated mechanical switches or contacts for multi-gun systems. A concussion actuated mechanical switch is activated by the force from a detonation. Guns are sequentially armed starting from the lowest gun using the force of the detonation to set a switch to complete the circuit to the gun above and to break connection to the gun below. The switches are used to step through the guns or charges from the bottom up to select which gun or charge to fire. However, if a switch in the string is defective, then the remaining guns above the defective gun become unusable. In the worst case situation, a defective switch at the bottom of the multi-string gun would render the entire string unusable.
[0005] Other conventional perforating systems do not allow for the confirmation of the identity of which gun in the string has been selected. The identity of the selected gun is inferred from the number of cycles in the counting process. As a result, it is possible to fire the wrong gun unless precautions are followed, including a physical measurement, such as a voltage drop or amount of current to determine which gun has been selected before firing. This, however, adds complexity to the firing sequence. Furthermore, such precautionary measures are typically not reliable.
SUMMARY
[0006] In general, according to one embodiment, the invention features a system to activate devices in a tool string. The system includes control that are adapted to communicate with a central controller. Switches are controllable by corresponding control units to enable activation of the devices.
[0007] Other features will become apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a diagram of a tool string incorporating an embodiment of the invention.
[0009] [0009]FIG. 2 is a block diagram of a control unit according to an embodiment used in the tool string of FIG. 1.
[0010] [0010]FIG. 3 is a flow diagram of software executed in a system to control activation of devices according to one embodiment.
[0011] [0011]FIG. 4 is a block diagram of a control system according to another embodiment of the invention.
[0012] [0012]FIG. 5 is a flow diagram of software executed in a system to control activation of devices according to the other embodiment.
[0013] [0013]FIG. 6 is a schematic diagram of a control unit in the control system according to the other embodiment.
DETAILED DESCRIPTION
[0014] Referring to FIG. 1, a perforating system 10 according to an embodiment of the invention for use in a well 12 is illustrated. The perforating system 10 in the illustrated embodiment includes a multi-gun string having a control system that may include multiple control units 14 A- 14 C that control activation of guns or charges in the string. Each control unit 14 may be coupled to switches 16 and 18 (illustrated as 16 A- 16 C and 18 A- 18 C). The cable switches 18 A- 18 C are controllable by the control units 14 A- 14 C, respectively, between on and off positions to enable or disable current flow through one or more electrical cables 20 (which may be located in a wireline or coiled tubing, for example) to successive control units. The switches 16 A- 16 C are each coupled to a detonating device 22 (illustrated as 22 A- 22 C) that may be found in a perforating gun for example. The detonating device may be a standard detonator, a capacitor discharge unit (CDU), or other initiator coupled to initiate a detonating cord to fire shaped charges or other explosive devices in the perforating gun. If activated to an on position, a switch 16 allows electrical current to flow to a coupled detonating device 22 .
[0015] In the illustrated embodiment, the switch 18 A controls current flow to the control unit 14 B, and the switch 18 B controls current flow to the control unit 14 C. For added safety, a dummy detonator 24 may optionally be coupled at the top of the string. The dummy detonator 24 is first energized and set up before the guns or charges below may be detonated. The dummy detonator 24 includes a cable switch 26 that controls current flow to the first control unit 14 A. The dummy detonator 24 also includes a control unit 31 as well as a dummy switch 28 , which is not coupled to a detonator.
[0016] The one or more electrical cables 20 extend through a wireline, coiled tubing, or other carrier to surface equipment (generally indicated as 30 ), which may include a surface system 32 , which may be a general-purpose or special-purpose computer, any other microprocessor- or microcontroller-based system, or any control device. The surface system 32 is configurable by tool activation software to issue commands to the downhole tool (e.g., perforating system 10 ) to set up and to selectively activate one or more of the control units 14 .
[0017] Bi-directional electrical communication (by digital signals or series of tones, for example) between the surface system 32 and control units 14 downhole may occur over one or more of the electrical cables 20 . The electrical communication according to one embodiment may be bi-directional so that information of the control units 14 may be monitored by the tool activation software in the surface system 32 . The information, which may include the control units' identifiers, status, and auxiliary data or measurements, for example, is received by the system 32 to verify correct selection and status information. This may be particularly advantageous where an operator at the wellsite desires to confirm which of the devices downhole has been selected before actual activation (or detonation in the case of a perforating gun or explosive).
[0018] In other embodiments, a system such as a computer or other control device may be lowered downhole with the tool string. This system may be an interface through which a user may issue commands (e.g., by speech recognition or keyboard entries).
[0019] In one embodiment of the invention, each control unit 14 may be assigned an address by the tool activation software in the surface system 32 during system initialization. One advantage provided by the soft-addressing scheme is that the control units 14 do not need to be hard-coded with predetermined addresses. This reduces manufacturing complexity in that a generic control unit can be made. Another advantage of soft-addressing is that the control units may be assigned addresses on the fly to manipulate the order in which devices downhole are activated. In other embodiments, the control units 14 may be hard coded with pre-assigned addresses or precoded during assembly. Additional information may be coded into the control units, including the type of device, order number, run number, and other information.
[0020] The tool activation system according to embodiments of the invention also allows defective devices in the string to be bypassed or “skipped over.” Thus, a defective device in a multi-device string (such as a gun string) would not render the remaining parts of the string inoperable.
[0021] Referring to FIG. 2, a control unit 14 and switches 16 and 18 according to an embodiment are shown. A microcontroller 100 (which may by way of example be an 8051 microcontroller made by any one of several manufacturers) forms the processing core of the control unit 14 , which communicates with other equipment (located downhole or at the surface) through an input/output (I/O) circuit 102 and the electrical cable 20 . The components of the control unit 14 may be powered by a power supply 110 . Other types of control devices may be substituted for the microcontroller 100 , including microprocessors, application specific integrated circuits (ASICs), programmable gate arrays (PGAs), discrete devices, and the like. Although the description of some embodiments refer to microcontrollers, it is to be understood that the invention is not to be limited to such embodiments. In this application, the term control device may refer to a single integrated device or a plurality of devices. In addition, the control device may include firmware or software executable on the control device.
[0022] In one embodiment, the microcontroller 100 may control the switches 16 and 18 through high side drivers (HSDs) 104 and 106 , respectively. HSDs are included in the embodiment of FIG. 2 since positive polarity voltages (typically in the hundreds of volts, for example) may be transmitted down the electrical cable 20 . The microcontroller 100 in the illustrated embodiment may be biased between a voltage provided by the power supply 110 and ground voltage. The outputs of the microcontroller 100 may be at TTL levels. To activate the switches 16 and 18 , the HSDs 104 and 106 , respectively, convert TTL-level signals to high voltage signals (e.g., one or two threshold voltages above the electrical cable voltage) to turn on field effect transistors (FETs) 112 and 114 . In further embodiments, HSDs may not be needed if negative polarity signals are transmitted down the electrical cable 20 . Other types of switches may be used, including, for example, switches implemented with bipolar transistors and mechanical-type switches.
[0023] The microcontroller 100 is adapted to receive commands from the tool activation program in the surface system 32 so that it may selectively activate FETs 112 and 114 as indicated in the commands. When turned on, the transistor 114 couples two sections 120 and 122 of the electrical cable 20 . Likewise, the transistor 112 couples the signal or signals in the upper section 120 of the cable 20 to the detonating device 22 . In addition, each microcontroller 100 may be configured according to commands issued by the tool activation program
[0024] Referring to FIG. 3, a flow diagram is shown of the tool activation program executable in the surface system 32 . Before any unit in the string is activated, a sequence of set up and verification tasks are performed. The tool activation program first sends a wake event (at 202 ) down the electrical cable 20 to a control unit 14 downhole. In one embodiment, the top control unit is the first to receive this wake event. This process is iteratively performed until all control units 14 in the multi-tool string have been initialized and set up.
[0025] The wake event is first transmitted to a control unit I, where I is initially set to the value 1 to represent the top control unit. The program next interrogates (at 204 ) the control unit I to determine its address and status (including whether it has been assigned an address or not), positions of switches 16 and 18 , and the status of the microcontroller 100 . If the control unit I has not yet been assigned an address, the program assigns (at 206 ) a predetermined address to the control unit I. For example, the bottom unit may be assigned the lowest address while the top unit is assigned the highest address. Thus, if activation is performed by sequentially incrementing the address, the bottom unit is activated first followed by units coupled above.
[0026] Next, the program requests verification of the assigned address (at 208 ). Next, the program confirms the assigned address (at 210 ). If an incorrect address is transmitted back by the control unit I, then the process at 202 - 210 is repeated until a correct address assignment is performed. If after several tries the address assignment remains unsuccessful, the control unit I may be marked defective. If the address is confirmed, then a command is sent by the tool activation program down the electrical cable 20 to close the cable switch 18 associated with the control unit I. This couples the electrical cable 20 to the next control unit I+1 (if any). The program may next interrogate (at 214 ) control units 1−I (all units that have been so far configured) to determine their status. This may serve as a double-check to ensure proper initialization and set up of the control units.
[0027] The program then determines if the end of the multi-tool string has been reached (at 216 ). If not, the value of I is incremented (at 218 ), and the next control unit I is set up ( 202 - 216 ).
[0028] If the end of the multi-tool string has been reached (as determined at 216 ), then all tools in the string have been configured and activation power may be applied (at 220 ) to the next functional control unit in the activation sequence, which the first time through may be the bottom control unit in one example. The activation power is transmitted down the cable 20 and through the switch 16 to initiate the detonating device 22 to fire the attached perforating gun.
[0029] The process is repeated to activate the other tools in the string. For example, if a control unit N has been activated to fire perforating gun N, then the control unit N−1 is classified as the last unit in the string. Power is removed from the electrical cable 20 and the tasks performed in FIG. 3 are then applied to the remaining control units (control units 1 to N−1, with control unit N−1 being considered the last control unit in the string). After sequencing through the tasks to set up the control units 1 to N−1, activation power may next be applied to control unit N−1. This process may be repeated for all tools in the string until the very top tool has been activated. In addition, if at any time interrogation by the program indicates that a control unit or tool is defective, that particular control unit and tool may be bypassed to activate the remaining control units. As a result, a defective tool does not render the entire multi-tool string inoperable.
[0030] Referring to FIG. 4, a tool activation system according to another embodiment of the invention is illustrated. The system includes a series of addressable control units 300 A- 300 C each coupled to corresponding tools 302 A- 302 C (which in the illustrated embodiment are detonating devices forming parts of perforating guns). Commands are transmitted by the surface system 32 to select one of the control units 300 A- 300 C. The command signals may be in the form of digital signals, a series of tones, or other types of communication, for example. The addressable control units 300 A- 300 C prevent power from reaching the detonating devices 302 A- 302 C prior to receipt of a specific command to arm the detonating devices. When addressed, each control unit responds with a specific identification and its status. The identification may include a manufacturer's serial number, an address, or some detailed information about the tool. Each control unit in the illustrated embodiment of FIG. 4 may include a microcontroller 304 (or another device or devices such as microprocessors, ASICs, PGAs, discrete devices, and the like) and switches 306 , 308 , 310 and 312 . The electrical cable 20 essentially feeds into a series of three switches 312 , 310 and 308 , all controllable by the microcontroller 304 . The switch 306 is a cable or cable switch that couples the electrical cable 20 above to the next control unit 300 . The arming sequence of the control unit is as follows: first the microcontroller 304 activates a PREARM signal to enable the switch 312 ; next, the microcontroller 304 asserts a signal ARM 1 to activate the switch 310 ; and finally, the microcontroller 304 activates a second arming signal ARM 2 to activate the third switch 308 . Only when all three signals are activated is shooting power provided to the detonating device 302 through the switches 306 - 310 . Further, as added precaution, the three signals need to be activated above certain threshold levels.
[0031] Once the detonating device 302 is initiated and the attached perforating gun fired, the cable switch 306 may be closed by the microcontroller 304 in response to a surface command to allow selection of the next control unit 300 . The cable switch 306 also can be used to bypass a defective control unit (such as a control unit that does not respond to a command).
[0032] Referring to FIG. 5, the tool activation control sequence according to this other embodiment of the invention is illustrated. First, a low amount of power is provided by the surface system 32 to the tool string (at 402 ) to activate the control units in the tool string. The amount of current supplied is sufficiently low to ensure that the coupled detonating devices 302 do not detonate in the event of an electrical connection failure. When the initial current is received by the first control unit ( 300 A), the microcontroller 304 starts an initialization sequence that maintains the PREARM and ARM signals deasserted. In addition, the microcontroller 304 sends data up the electrical cable to the surface system 32 that includes the microcontroller's address and a status of disarmed. Other information may also be included in the data transmitted to the surface.
[0033] The tool activation program in the surface system next determines if a response has been received (at 404 ) from a tool down below. If so, the received data may be stored and displayed to a user (at 406 ). Next, the program sends a command to couple to the next control unit in the sequence by closing the cable switch 306 . In response, the microcontroller 304 activates the control signal to the cable switch 306 to close it. In one embodiment, the microcontroller 304 may be coupled to a timing device. If the microcontroller 304 does not respond to the bypass switch close command, the timing device would expire to activate the closing of the switch 306 .
[0034] Next, the program waits for a time-out condition (at 410 ), which indicates the end of string has been reached. Control units are adapted to respond within a certain time period—if no response is received within the time period, then the surface system assumes that either no more devices or a defective device is coupled downstream. The process at 404 - 410 is repeated until the end of string is reached.
[0035] The surface system program next creates (at 410 ) a list of all detected devices downhole. As an added precaution, the user may compare this list with an expected list to determine if the string has been properly configured. The list of detected devices can also identify device timings as well as devices that are defective. Thus, the user may be made aware of such defective devices downhole, which are bypassed in the activation sequence.
[0036] To activate a particular tool downhole, the user would issue a command to the surface system. When the tool activation program receives this user command (at 412 ), it transmits an activate command or series of commands (which includes an address of the selected control unit) down to the tool string (at 414 ). At this point, because of the initialization process, all the cable switches 306 in all the control units are closed. Thus, each of the microcontrollers 304 is able to receive and decode the activate command. However, only the microcontroller 304 with a matching address will respond to the activate command. When the surface system program receives a confirmation from the selected device downhole (at 416 ), it checks the information transmitted with the confirmation to verify that the proper device has been selected. If so, the surface system program enables the supplying of activation power to the selected device (at 418 ). The tool activation program then waits for the next activation command.
[0037] The addresses of the control units may be preset during manufacture. Alternatively, jumpers or switches may be set in these control units to set their addresses. Another method includes the use of nonvolatile memory in the control units that may be programmed with the control unit's address any time after manufacture and before use.
[0038] Referring to FIG. 6, some of the circuits of a control unit according to the alternative embodiment are illustrated in more detail. The illustrated embodiment is merely one example of how the control unit may be implemented—other implementations are possible. The electrical cable 20 is coupled from above through a diode 502 to a node N 1 in the control unit 300 . An over-voltage protection circuit 504 couples the internal node N 1 to ground to protect circuitry from an over-voltage condition. The microcontroller 304 includes a receive input (RCV) to receive data over the cable 20 and a transmit output (XMIT) to transmit data to the cable 20 . The RCV input is coupled to an output of an inverter 506 , whose input is coupled to a resistor and capacitor network including resistors 508 , 510 and a capacitor 512 all coupled between node N 1 and the ground node. A signal coming down the cable 20 is received by the input of the inverter 506 and provided to the RCV input of the microcontroller 304 . The XMIT output drives the cathode of a diode 514 . A zener diode 516 is coupled between the anode of the diode 514 and node N 1 . On the other side, a resistor 518 is coupled between the anode of the diode 514 and ground.
[0039] A clock generator 520 provides the clock input to the microcontroller 304 . The other outputs of the microcontroller 304 include signals PREARM, ARM 1 , and ARM 2 . Logically, as shown in FIG. 4, the signals PREARM, ARM 1 , and ARM 2 control switches 312 , 310 and 308 , respectively, in each control unit. These switches 312 , 310 and 308 may be implemented using serially coupled transistors 522 and 524 , which couple the node N 1 to the detonating device 302 through a diode 526 . The gate of the transistor 522 is coupled through a resistor 528 and a diode 530 to the signal PREARM of the microcontroller 304 . The gate of the transistor 522 is also driven by the output of an inverter 532 through a resistor 534 . The input of the inverter 532 is coupled to the signal ARM 2 controlled by the microcontroller 304 . The gate of the transistor 524 is driven by the output ARM 1 from the microcontroller 304 . Thus, the sequence for activating the detonating device 302 is as follows: the signal PREARM is driven high, the signal ARM 1 is driven high, and the signal ARM 2 is driven low. This turns both transistors 522 and 524 on to couple power from the electrical cable 20 through node N 1 to the detonating device 302 .
[0040] The cable switch 306 in one embodiment may be implemented with a transistor 536 , which couples the internal node N 1 of the control unit to the cable down below. The gate of the transistor 536 is coupled to a node BYPG that is the output of an RC network formed by a resistor 538 and a capacitor 539 . The other side of the resistor 538 is coupled to a bypass output (BYP) of the microcontroller 304 . In the illustrated embodiment, the timing device to bypass a defective microcontroller is formed by the resistor 538 and the capacitor 539 . Thus, if the microcontroller 304 is not functioning for some reason, a pull-up resistor (not shown but coupled to the output pin BYP either internally or externally to the microcontroller) pulls the node BYPG to a “high” voltage after an amount of time determined by the RC constant defined by the resistor 538 and the capacitor 539 . The node BYPG is coupled to the gate of a FET 536 , which is part of the cable switch 306 . When the node BYPG is pulled high after the time delay, the FET 536 is turned on, which allows communication to downstream devices on the electrical cable. This allows a defective microcontroller to be bypassed.
[0041] In the illustrated embodiment of FIG. 6, negative polarity signals are transmitted down the electrical cable 20 . The microcontroller is biased between the voltage at node N 1 and a high voltage provided by a power supply (not shown). To turn off the transistors 522 , 524 , and 536 , the gates of those transistors are driven to the voltage of N 1 . To activate the transistors, their gates are driven to the power supply high voltage.
[0042] Other embodiments are within the scope of the following claims. For example, although the drawings illustrate a perforating system that may include multiple guns or explosives, other multi-device tool strings may incorporate the selective activation system described. For example, such tool strings may include coring tools.
[0043] While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of the invention. | A tool activating system includes a multiple control units coupled to activate devices in a tool string positioned in a well. A processor is capable of communicating with the control units to send commands to the control units as well as to retrieve information (such as unique identifiers and status) of the control units. Selective activation of the control units may be performed based on the retrieved information. Further, defective control units or devices may be bypassed or skipped over. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a convertible motor vehicle roof such as for hatchbacks or pickups.
2. Description of Related Art
The published European application EP 0 989 008 A2 discloses one such motor vehicle roof for a motor vehicle which has a louvered roof with several louvered roof parts which are arranged behind one another. The louvered roof parts are hinged to one another and are movably supported on guides on side lengthwise roof frames or side roof members. To open the louvered roof, the louvered roof parts are moved on the guides to the rear into a storage space in a rear door and then are arranged, stacked in a vertical alignment.
SUMMARY OF THE INVENTION
The primary object of the invention is to provide a convertible motor vehicle roof with greater flexibility. Another object of the invention is to provide such a convertible motor vehicle roof with at least one roof part which is supported to move lengthwise on the side roof members so that when the roof is being opened, the roof part is movable into a storage position.
These and other objects and advantages are achieved in the aforementioned motor vehicle roof in accordance with the present invention in that the roof part or roof parts are moveable onto a roof unit or rear unit before lowering of the roof into a storage space. The storage space compactly accommodates the roof part or the roof parts arranged stacked therein so that due to the reduced space requirement, the possibilities for movement and storage on the body for the movable and storable roof parts are improved. The roof part may be formed in different ways, for example by a folding roof, a shade roof or a solid roof element, or the motor vehicle roof is a louvered roof with several louvers as the roof parts.
Feasibly, the roof parts together with the movable roof unit or the movable rear unit, may be moved into the storage position. Thus, the roof parts are first transferred to a storage space which is advantageously arranged under structural or formal boundary conditions. The storage space is then moved with the roof unit or rear unit which contains it when the roof is being lowered to the final storage position for the roof parts.
According to one advantageous embodiment, the roof parts, together with the movable roof unit or the movable rear unit, may be moved into the storage position.
In one embodiment, the storage space for the roof parts is located preferably on the roof cassette, the rear element or the rear door.
The roof unit may preferably be a roof cassette which forms a rear roof section and which contains the storage space for the roof parts which are stacked.
According to another advantageous embodiment of the present invention, the side roof member located in front of the roof unit or the roof cassette is moved by a bearing means laterally next to or to under the roof cassette when the roof is being opened.
The rear unit preferably includes a rear element which extends over the width of the motor vehicle and/or two lateral rear columns.
According to one embodiment, the roof cassette is supported on a motor vehicle side part by a lateral rear column which is hinged on the roof cassette, and when the roof cassette is being lowered, is swivelled into a side horizontal position.
To attain the above, the lateral rear column is preferably movably supported on its lower end on a guideway on the side part of the motor vehicle.
Preferably, the roof cassette is movably supported by a front rod on the side part of the motor vehicle and the front rod, together with the rear column, forms a four-bar mechanism by which the roof cassette can be lowered into the storage position, especially in a horizontal alignment.
The roof part or the roof parts can be accommodated, stacked in a rear door according to one advantageous embodiment, and the rear element which has one rear column, and one top rear transverse part at a time is, on the one hand, pivotally attached via the rear column to the body, and on the other hand, is hinged to the side roof member.
The side roof member on the rear element is supported in a joint which guides the side roof member to the outside when the rear element is being swivelled forward, and at the same time, swivels it down, the support on the other end of the side roof member enabling a swivelling-sliding motion.
The roof part or roof parts may be accommodated stacked in a rear door according to one advantageous embodiment and the roof unit is a roof cassette which forms the rear roof section. Furthermore, the side roof member which is located in front of the roof cassette when the roof is being opened, may be moved to under the roof cassette by a bearing means. Finally, the lateral rear column supports the roof cassette on the side part of the motor vehicle which is hinged to the roof cassette, and is swivelled into a lateral horizontal position when the roof cassette is being lowered.
The lateral rear column or the rear element is movably supported on its bottom end on or in a guideway on the motor vehicle side part.
The roof cassette is movably supported by a front rod on the motor vehicle side part, and the front rod, together with the rear column, forms a four-bar mechanism by which the roof cassette can be lowered into the storage position, especially in a horizontal alignment.
Preferably, the side roof member which is located in the lengthwise direction of the motor vehicle in front of the roof unit or the roof cassette when the roof is being opened, is located laterally on the roof cassette by the bearing means.
The lateral rear column supports the roof cassette on a motor vehicle side part. It is hinged on the roof cassette and swivels when the roof cassette is being lowered into a lateral horizontal position.
The lateral rear column is preferably movably supported on its bottom end on, or in, a guideway on the motor vehicle side part.
These and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the invention when viewed in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic side view of a motor vehicle with a convertible motor vehicle roof in accordance with one embodiment of the present invention;
FIGS. 2.1 to 2 . 3 each show a perspective rear view of a first embodiment of the convertible roof in different positions of motion when being stored;
FIGS. 3.1 to 3 . 3 each show a perspective rear view of a second embodiment of the convertible roof in different positions of motion when being stored;
FIGS. 4.1 to 4 . 3 each show a perspective rear view of a third embodiment of the convertible roof in different positions of motion when being stored;
FIGS. 5.1 to 5 . 6 each show an angled side view of another embodiment of the convertible roof in different positions of motion when being stored;
FIGS. 6.1 to 6 . 5 each show an angled side view of another embodiment of the convertible roof in different positions of motion when being stored;
FIG. 7 shows a schematic side view of another embodiment of the convertible roof in the converted stored position;
FIG. 8 shows a schematic side view of still another embodiment of the convertible roof in the converted stored position;
FIG. 9 shows a schematic side view of yet another embodiment of the convertible roof in the converted stored position;
FIG. 10 shows a schematic side view of another embodiment of the convertible roof in the converted stored position;
FIG. 11 shows a schematic side view of still another embodiment of the convertible roof in the converted stored position;
FIG. 12 shows a schematic side view of another embodiment of the convertible roof in the converted stored position;
FIG. 13 shows a schematic side view of yet another embodiment of the convertible roof in the converted stored position;
FIG. 14 shows a schematic side view of another embodiment of the convertible roof in the converted stored position;
FIG. 15 shows a schematic side view of still another embodiment of the convertible roof in the converted stored position;
FIG. 16 shows a schematic side view of another embodiment of the convertible roof in the converted stored position;
FIG. 18 shows a schematic side view of yet another embodiment of the convertible roof in the converted stored position;
FIGS. 18.1 to 18 . 3 each show a schematic side view of one embodiment of the convertible roof, FIG. 18.1 and 18 . 2 showing the storage space for louvered roof parts of a louvered roof when the roof is in a closed configuration while FIG. 18.3 shows the same embodiment with the storage space containing the motor vehicle roof;
FIG. 19 shows a schematic side view of one embodiment of the convertible roof with the storage space for louvered roof parts of a louvered roof when the roof is in a closed configuration;
FIGS. 20.1 to 20 . 3 each show a schematic side view of another embodiment of the convertible roof, FIG. 20.1 and 20 . 2 showing the storage space for louvered roof parts of a louvered roof when the roof is in a closed configuration while FIG. 20.3 shows the same embodiment with the storage space containing the motor vehicle roof;
FIGS. 21.1 to 21 . 3 each show a schematic side view of still another embodiment of the convertible roof, FIG. 21.1 and 21 . 2 showing the storage space for louvered roof parts of a louvered roof when the roof is in a closed configuration while FIG. 21.3 shows the same embodiment with the storage space containing the motor vehicle roof;
FIG. 22 shows a schematic side view of one embodiment of the convertible roof with the storage space for louvered roof parts of a louvered roof when the roof is in a closed configuration;
FIG. 23 shows a schematic side view of another embodiment of the convertible roof with the storage space for louvered roof parts of a louvered roof when the roof is in a closed configuration;
FIGS. 24.1 and 24 . 2 each show a schematic side view of one embodiment of the convertible roof, FIG. 24.1 showing the storage space for louvered roof parts of a louvered roof while FIG. 24.2 shows the same embodiment with the motor vehicle roof in an opened configuration;
FIGS. 25.1 and 25 . 2 each show a schematic side view of another embodiment of the convertible roof, FIG. 25.1 showing the storage space for louvered roof parts of a louvered roof while FIG. 25.2 shows the same embodiment with the motor vehicle roof in an opened configuration;
FIGS. 26.1 and 26 . 2 each show a schematic side view of still another embodiment of the convertible roof, FIG. 26.1 showing the storage space for louvered roof parts of a louvered roof while FIG. 26.2 shows the same embodiment with the motor vehicle roof in an opened configuration;
FIGS. 27.1 and 27 . 2 each show a schematic side view of yet another embodiment of the convertible roof, FIG. 27.1 showing the storage space for louvered roof parts of a louvered roof while FIG. 27.2 shows the same embodiment with the motor vehicle roof in an opened configuration;
FIGS. 28.1 and 28 . 2 each show a schematic side view of another embodiment of the convertible roof, FIG. 28.1 showing the storage space for louvered roof parts of a louvered roof while FIG. 28.2 shows the same embodiment with the motor vehicle roof in an opened configuration.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a motor vehicle such as a station wagon or a general purpose vehicle with a fastback contains a body 1 with a rear fixed motor vehicle side part 2 which is located on each side of the vehicle and which extends from the B column 3 to the rear towards the back of the motor vehicle. The front fixed side roof member 4 extends as far as the body-mounted C column 5 . The motor vehicle roof 6 to be opened contains a louvered roof with several movable louvered roof parts 7 which are made as solid, openable roof parts and which in the closed position of the motor vehicle roof 6 , are located behind one another. The movable louvered roof parts 7 are movably supported laterally toward the front by the fixed side roof member 4 and toward the rear by movably supported side roof member 8 . The rear section of the motor vehicle roof 6 is formed by a roof cassette 9 which adjoins the two movable side roof members 8 and is supported via a rear unit in the form of the two lateral rear columns 10 on the back end 11 of the rear fixed side parts 2 . The rear unit can also be a rear element which extends over the width of the motor vehicle.
The rear side window 12 , with the motor vehicle roof 6 closed tightly, adjoins the rear side roof member 8 , the roof cassette 9 , and the lateral rear column 10 . The rear side window 12 may be lowered or otherwise removed from this position into the side part 2 when the motor vehicle roof 6 is to be opened and converted and the elements of the roof 6 are lowered into the storage position.
Since the motor vehicle and the motor vehicle roof 6 are made largely symmetrical with respect to the vertical middle lengthwise plane of the motor vehicle, the motor vehicle roof is illustrated and described simply using the motor vehicle side or motor vehicle half as shown.
To open the roof opening 13 in the manner shown in FIGS. 2.1 to 2 . 3 , the louvered roof parts 7 are pushed on lateral guides (not shown) by a drive into the roof cassette 9 as shown in FIG. 2.1, and stored stacked on top of one another therein. To convert the motor vehicle roof 6 , after the lowering of the rear window and side windows 12 (not shown), the side roof member 8 is pushed laterally next to the roof cassette 9 by a mechanism which is formed, for example, in the manner of a sliding door mechanism. In this regard, after releasing the connection to the front side roof member 4 , a cable drive (not shown) driven by an electric motor may be used to execute the displacement motion of the side roof member 8 .
The rear column 10 which is pivotally mounted on the roof cassette 9 via a joint 14 around a transverse axis, is movably supported on its lower end by rod 15 in a guideway 16 located on the side part 2 . The roof cassette 9 is also pivotally mounted on the C column 5 via a front rod 17 which is pivotally mounted both on the roof cassette 9 , and also on the C column 5 . To lower the roof cassette 9 , the rod 15 is pushed forward (toward the front of the vehicle) in the guideway 16 and is fixed in the front end position 18 such that the rear column 10 is located in the swivel position which forms a four-bar mechanism which consists of a front rod 17 and a rear column 10 with its rod 15 as shown in FIG. 2.2.
The four-bar mechanism which is moved via the drive means swivels the roof cassette 9 by the intended swivelling movements of the front rod 17 and the rear column 10 with its rod 15 into the horizontal storage position in or on the trunk compartment.
Conversion of the motor vehicle roof 6 in the closing process takes place in the opposite sequence of motions.
Various other embodiments of a convertible motor vehicle roof are described herein below, common reference numerals being used for similar features in the various embodiments to facilitate understanding. A second embodiment of a convertible motor vehicle roof 6 is shown in FIGS. 3.1 to 3 . 3 that contains, instead of the above described roof cassette 9 , a rear element 19 which has a top rear transverse part 21 which joins two rear columns 20 , only one being shown. The rear element 19 is movably connected by a joint mechanism 22 to the side roof member 8 . The movable side roof member 8 on its front end, has an attached rod 23 which is supported on the side roof member 4 or on the C column 5 so that it is able to swivel and move translationally. The rear element 19 is furthermore mounted by means of a joint 24 which is attached to the back end of the rear column 20 on the back end 11 of the fixed side part 2 to be able to swivel essentially around the transverse axis of the motor vehicle.
When the motor vehicle roof 6 is opened and converted, the louvered roof parts 7 are pushed on lateral guides (not shown) into a rear door 25 and held therein in the storage position in a stacked arrangement. After the lowering of the rear window and the side windows 12 (not shown), the side roof member 8 is swivelled out of the fixed arrangement on the rear element shown in FIG. 3.1 via the joint mechanism 22 on its back end, into a position, for example, next to the rear element 19 so that the rear element 19 can be swivelled around the joint 24 and forward into the trunk compartment. In doing so, the side roof member 8 which is entrained via the joint mechanism 22 , is swivelled via its rod 23 relative to the fixed side roof member 4 into a position along the C column 5 as shown in FIG. 3.3. The rod 23 can execute the required translational compensation motion on its support on the side roof member 4 , on the movable side roof member 8 , or by a telescoping configuration.
In a third embodiment shown in FIGS. 4.1 to 4 . 3 which represents a modification of the first embodiment, the louvered roof parts 7 are pushed into the rear door 25 and accommodated therein in the storage position in a stacked arrangement. The movable side roof member 8 is pushed into the roof cassette 9 by a mechanism which can also be formed, for example, in the manner of a sliding door mechanism after releasing the connection to the front side roof member 4 . The mechanism may have a cable drive (not shown) driven by an electric motor to allow execution of the displacement motion.
According to a fourth embodiment as shown in FIGS. 5.1 to 5 . 6 , the motor vehicle roof 6 which has been modified relative to the aforementioned embodiments contains a rear movable side roof member 26 which extends as far as the top end of the lateral rear column 10 in the closed position of the motor vehicle roof 6 in the manner shown in FIG. 5.1. The roof cassette 9 is located between the two side roof members 26 which are laterally opposite one another and the roof cassette 9 is supported via a rod arrangement 27 on the respective side part 2 of the body. The rod arrangement 27 contains a front four-bar mechanism with a first rod 28 and a second rod 29 which on the one hand, are supported in swivel joints 30 and 31 on the side part 2 , and on the other hand are pivotally connected to the connecting rod 32 which in turn, is pivotally connected on its other end via a joint 33 to the roof cassette 9 , for example, on its front section.
The rod arrangement 27 further contains a rear, roughly L-shaped rod 34 which is pivotally mounted in a joint 35 on the side part 2 and is connected via a coupling rod 36 to the rod 29 of the front four-bar mechanism, and is also connected to the rear column 10 via a rod 37 which is rigidly attached to the rear column 10 . The rear column 10 contains, on its top end, a permanently attached rod 38 which is clearly shown in FIG. 5.2 which is coupled in a joint 39 to the rear section of the roof cassette 9 as shown in FIG. 5.3.
The side roof member 26 is supported laterally on the roof cassette 9 or on the rods 32 and 38 . The support is attained, for example, via a four-bar mechanism (not shown) located in the plane which is tilted to the roof cassette 9 that acts to swivel the side roof member 26 to the outside and down relative to the roof cassette 9 when the roof cassette 9 is being lowered. The four-bar mechanism may be coupled to the rod arrangement 27 for executing its motion or can be driven by its own drive.
When the motor vehicle roof 6 is being opened and converted, the louvered roof parts 7 are first moved into or under the roof cassette 9 as shown in FIG. 5.1. By swivelling the front four-bar mechanism, for example, by a hydraulic cylinder which engages the rod 28 or the rod 29 and correspondingly, the coupling rod 32 and the rear column 10 which is coupled to it, the roof cassette 9 is lowered through the intermediate positions shown in FIGS. 5.2 to 5 . 5 into the storage position as shown in FIG. 5.6. In doing so, the side roof member 26 is initially decoupled from the front fixed side roof member 4 , and then swivelled out and down around the lengthwise axis such that the front end of the side roof member 26 is lowered inwardly of the C column.
The side separating line which runs in the preceding embodiment of FIGS. 4.1 to 4 . 3 between the side roof member 8 and the roof cassette 9 in the transverse plane is eliminated in this embodiment shown in FIGS. 5.1 to 5 . 6 in which the side roof member 26 runs along the roof cassette 9 and the separating line is thus located in the lengthwise plane in a continuation of the lengthwise line on the roof section formed by the louvered roof parts 7 .
An embodiment which has been modified relative to the above described embodiment is shown in FIGS. 6.1 to 6 . 5 . The rod arrangement 27 likewise contains the front four-bar mechanism with the first rod 28 and the second rod 29 in the described arrangement. The rod arrangement 27 furthermore contains a rear four-bar mechanism with a first rod 40 and a second rod 41 which on the one hand, are supported in swivel joints 42 and 43 on the side part 2 , and on the other hand, are pivotally connected to the coupling rod 44 which in turn is pivotally coupled on its other end via a joint 45 to the rear column 10 . The rear column 10 is in turn, coupled via attached rod 38 and joint 39 to the rear section of the roof cassette 9 as shown in FIG. 6.2. The coupling rod 46 is attached to the rod 29 of the front four-bar mechanism and is pivotally coupled to a coupling section 47 of the first rod 40 of the rear four-bar mechanism via joint 48 .
Opening and converting the motor vehicle roof 6 take place in a similar way as the previous embodiments, by swivelling the front or the rear four-bar mechanism, for example, by a hydraulic cylinder, which engages one of the respective rods. The swiveling motion is initiated and the roof cassette 9 is lowered through the intermediate positions shown in FIGS. 6.2 to 6 . 4 into the storage position as shown in FIG. 6.5.
FIGS. 7 to 17 each show various embodiments of the motor vehicle roof 6 each in their converted open position and are each discussed briefly below.
FIG. 7 shows one embodiment which is similar to the embodiment shown in FIGS. 2.1 to 2 . 3 . The louvered roof parts 7 are moved into the roof cassette 9 . The side roof member 8 is folded under the roof cassette 9 . The rear column 10 which is connected to the roof cassette 9 , is lowered under the roof cassette 9 via the lowering motion of the roof cassette 9 . The roof cassette 9 is stored with the side roof member 8 and the rear column 10 over the trunk compartment. According to one version, the side roof member 8 is placed laterally against the roof cassette 9 in accordance with the embodiment shown in FIGS. 2.1 to 2 . 3 . Advantages of this embodiment include a very compact arrangement of the stored roof without adversely affecting the back seats, good trunk accessibility, protection of the trunk compartment by the roof cassette, and the possibility of using conventional rear doors.
FIG. 8 shows one embodiment in which the louvered roof parts 7 are moved into the roof cassette 9 , and the rear column 10 which is connected to the roof cassette 9 is lowered into the side space of the trunk compartment via the lowering motion of the roof cassette. The roof cassette 9 is stored over the trunk compartment, while the side roof member 8 is swivelled to the C column. Advantages of this embodiment include good trunk compartment accessibility, protection of the trunk compartment by the roof cassette, and the possibility of using a conventional rear door.
FIG. 9 shows one embodiment in which the louvered roof parts 7 are moved into the roof cassette 9 and the side roof member 8 , in its original arrangement on the roof cassette 9 , remains connected to it. The rear column 10 is folded under the roof cassette 9 . The roof cassette 9 is then stored over the trunk compartment. This embodiment has the advantage that the roof cassette 9 and the side roof member 8 form a unit which need not be separated. In addition, this embodiment also has the advantage that the trunk compartment has good accessibility, that the trunk compartment is protected by the roof cassette and that there is the possibility of using a conventional rear door or a production rear door. According to one version, the rear column 10 is connected to the roof cassette 9 such that the rear column 10 is stored under the roof cassette 9 via the lowering motion of the roof cassette 9 .
In the embodiment shown in FIG. 10, the louvered roof parts 7 are also moved into the roof cassette 9 . The side roof member 8 is folded inwardly to the front of the roof cassette 9 in a transverse alignment and the rear column 10 is folded under the roof cassette 9 . The roof cassette 9 is then stored with the folded-on parts 8 and 10 over the trunk compartment. This embodiment has the advantage of a compact arrangement. Furthermore, the back seats are not adversely affected, the trunk compartment is easily accessible and protected by the roof cassette, a production rear door can be used, and there are no collision problems between the side roof member 8 and the rear column 10 in the folded-in state. According to one version, the rear column 10 is connected to the roof cassette 9 such that the rear column 10 is stored under the roof cassette 9 via the lowering motion of the roof cassette 9 .
The embodiment shown in FIG. 11 is a modification of the embodiment shown in FIG. 10 . In contrast to the embodiment of FIG. 10, the shown embodiment of FIG. 11 contains a rear column 10 which is folded inwardly under the roof cassette 9 in a transverse alignment. Advantages include a compact arrangement, no adverse affect on the back seats, protection of the trunk compartment by the roof cassette 9 , using a production rear door, a connection between the roof cassette 9 and the side roof member 9 , and no possibility of collision between the side roof member 8 and the rear column 10 .
The embodiment shown in FIG. 12 is a modification of the embodiment shown in FIG. 8 . In contrast to the embodiment of FIG. 8, the shown embodiment of FIG. 12 contains a side roof member 8 which is placed underneath against the roof cassette 9 . Alternatively, the side roof member 8 may be placed laterally against the roof cassette 9 . In this way, there is no adverse affect on the back seats, the trunk compartment is protected by the roof cassette 9 , there is good accessibility of the trunk compartment, a production rear door can be used, and there is no possibility of collision between the side roof member 8 and the rear column 10 .
In the embodiment shown in FIG. 13, the louvered roof parts 7 are moved into the roof cassette 9 . The side roof member 8 is swivelled inwardly to the C column and the roof cassette 9 , which is rigidly connected to the rear column 10 , is folded forward into the trunk compartment so that in the stored position, it is located behind the rear seatbacks. This embodiment offers good accessibility to the trunk compartment and a production rear door can be used. Finally the roof cassette 9 and the rear column 10 can remain joined.
FIG. 14 shows the embodiment shown in FIGS. 3.1 to 3 . 3 in the open stored position in which the louvered roof parts 7 are moved into the rear door 25 , and instead of the roof cassette 9 , there is rear element 19 with the two rear columns 20 and the connecting top rear transverse part 21 . The long side roof member 8 is swivelled on or into the C column 5 and the rear element 19 is folded forward over the trunk compartment. This embodiment provides good trunk compartment accessibility, a large volume of the trunk compartment, and few roof elements.
In the embodiment shown in FIG. 15, the louvered roof parts 7 are moved into the rear door 25 , the side roof member 8 is stored in the roof cassette 9 and the rear column 10 is folded under the roof cassette 9 . The roof cassette 9 is then stored with the side member 8 and the rear column 10 over the trunk compartment. In one version, the rear column 10 is connected to the roof cassette 9 by a joint connection which lowers the rear column 10 to under the roof cassette 9 by the lowering motion of the roof cassette 9 . Advantages of this embodiment include a very compact arrangement of the stored roof without adversely affecting the back seats, good trunk compartment accessibility, protection of the trunk compartment by the roof cassette, and low weight of the roof cassette 9 since the roof louvers 7 are stored in the rear door 25 .
In the embodiment shown in FIG. 16, the louvered roof parts 7 are moved via guides (not shown) to a position behind the rear seatbacks into a storage space in which they are located in the upright position. The side roof member 8 is folded laterally to the front end of the roof cassette 9 roughly in the upright alignment of the louvered roof parts 7 . The rear column 10 is connected to the roof cassette 9 and is stored under the roof cassette 9 via the lowering motion of the roof cassette 9 . The roof cassette 9 is stored over the trunk compartment with the parts folded. In one version, the rear column 10 is folded under the roof cassette 9 and is stored with it. Advantages of this embodiment include low weight of the roof cassette 9 , no adverse affect on the back seats since the louvered roof parts 7 are stored in the rear door 25 , good accessibility of the trunk compartment, protection of the trunk compartment by the roof cassette, and the possibility of using a production rear door.
FIG. 17 shows an embodiment in which the louvered roof parts 7 are likewise located behind the rear seatbacks in the upright position. The side roof member 8 remains securely joined to the roof cassette 9 and the rear column 10 is folded under or laterally next to the roof cassette 9 . The roof cassette 9 is stored with the parts folded over the trunk compartment. In one version, the rear column 10 is connected to the roof cassette 9 by a joint connection which lowers the rear column 10 under or laterally next to the roof cassette 9 by the lowering motion of the roof cassette 9 . This embodiment offers good trunk compartment accessibility, the trunk compartment is protected by the roof cassette, and a production rear door can be used. Finally, the roof cassette 9 and the side roof member 8 can remain joined to one another in the original alignment.
The storage space for the louvered roof parts 7 on the roof cassette 9 is bounded in one embodiment shown in FIGS. 18.1 to 18 . 3 by a variable bottom part 50 which is shifted down via a scissors mechanism 51 from its neutral position on a top holder 52 , against the force of a tension spring 53 in order to open the storage space 29 to the size necessary for accommodating the louvered roof parts 7 . The louvered roof parts 7 are moved via a guide rail 54 on the front fixed side roof member 4 or via a guide rail 55 on the rear side roof member 8 and via a feed 56 into the storage space.
The storage space shown in FIG. 19 is formed by two rails 57 and 58 which can be folded down out of their horizontal arrangement to an angled or vertical arrangement on the feed 56 for the louvered roof parts 7 and thus, form the storage space.
FIGS. 20.1 to 20 . 3 show a storage space which is located on the rear element 10 which is formed like the storage space of FIG. 18 . The storage space includes a movable bottom part 50 which is shifted to the inside from its neutral position on a holder 52 via the scissors mechanism 51 , the holder 52 being mounted on the rear element 10 against the force of a tension spring 53 . The louvered roof parts 7 are moved via the feed 56 into the storage space and are accommodated therein in an essentially upright and stacked arrangement shown in FIG. 20.3.
The storage space can be located in or behind a rear door 59 as well as shown in FIGS. 21.1 to 21 . 3 . The louvered roof parts 7 are moved via the feed 56 which is elongated downward into the storage space and are accommodated therein in an essentially vertical and stacked arrangement as shown in FIG. 21.3. As in the preceding example, the storage space is formed with a variable, movable bottom part 50 .
Furthermore, the storage space which is formed as shown in FIG. 19 with two folding rails 57 and 58 can be located on the rear element 10 as shown in FIG. 22, or on the rear door 59 as shown in FIG. 23 .
FIG. 24.1 shows one embodiment of the roof in which the stacked louvered roof parts 7 are located on the roof cassette 9 . The roof cassette 9 is rigidly connected to the rear element 10 which is movably supported on the guide rails 60 located in the rear area of the body. The roof cassette 9 is lowered as a unit with the rear element 10 and the side roof member 8 as shown in FIG. 24.2.
FIG. 25.1 shows one embodiment of the roof in which the roof cassette 9 and the side member 8 form a unit and are movably supported via a four-bar mechanism with a first rod 61 and a second rod 62 on the C column. The roof cassette 9 contains the storage space for the louvered roof parts 7 and is connected to the rear element 10 via a swivel joint 63 . The rear element 10 is movably supported on its lower end in a curve-shaped guide rail 64 . To lower the roof cassette 9 the rear element 10 is swivelled forward with a lower bearing 65 along the guide rail 64 and is lowered together with the roof cassette 9 and the side roof member 8 in the manner shown in FIG. 25.2.
FIG. 26.1 shows one embodiment of the roof which is similar to the above described embodiment, but which contains the storage space for the louvered roof parts 7 in or behind the rear door 59 . Lowering takes place in a similar manner as shown in FIG. 26.2.
FIGS. 27.1 and 27 . 2 show one modification of the embodiment as shown in FIGS. 24.1 and 24 . 2 in that the storage space for the louvered roof parts 7 are located on the rear element 10 . Lowering takes place otherwise in a similar manner as shown in FIG. 27.2.
FIGS. 28.1 and 28 . 2 show a modification of the embodiment as shown in FIGS. 25.1 and 25 . 2 in that the storage space for the louvered roof parts 7 are located on the rear element 10 . Lowering takes place otherwise in a similar manner.
While various embodiments in accordance with the present invention have been shown and described, it is understood that the invention is not limited thereto. The present invention may be changed, modified and further applied by those skilled in the art. Therefore, this invention is not limited to the detail shown and described previously, but also includes all such changes and modifications. | A convertible motor vehicle roof, especially for hatchbacks or pickups, with at least one roof part which is supported to move lengthwise on the side roof members and when the roof is being opened, can be moved into the storage position. The roof part or roof parts can be moved onto a roof unit or rear unit before lowering of the roof into a storage space. The storage space compactly accommodates the roof part or the roof parts arranged stacked therein so that due to the reduced space requirement, the possibilities for movement and storage for the movable and storable roof parts on the motor vehicle body are improved. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional Patent Application No. 61/233,111 filed Aug. 11, 2009.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable.
REFERENCE TO A SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISC
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] A. Field of the Invention
[0005] The field of the present invention relates generally to apparatuses and systems for dispersing a substance, such as water or various chemicals, over an area where application of such substance is believed to be beneficial. In particular, the present invention relates to such dispersing apparatuses and systems that are configured to effectively and efficiently disperse a substance over a large area. Even more particularly, this invention relates to such apparatuses and systems that utilize rotary atomizers and fans to disperse the substance.
[0006] B. Background
[0007] As generally well known, there is often a need to disperse a substance over an area to benefit persons, animals or plants in the area, to treat the land or crops growing on the land or to achieve other beneficial objectives. For instance, at a gathering of people in an outdoor area during warm or hot weather, it is well known to disperse water, in the form of a mist, over the area to cool the people who are at least generally in the sprayed area. Such systems are commonly utilized at outdoor restaurants, concerts and like outdoor gatherings. Substance dispersing systems are also utilized by those in the business of raising animals and crops. For instance, those in the business of raising milk cows know that higher ambient air temperatures generally reduce the production efficiency of the cows. Because it is usually neither practical nor economic to maintain the cows in an air conditioned facility, during the summer months milk cows are substantially exposed to the hot ambient air temperatures. Shading and various cooling devices and systems are utilized in an attempt to cool the cows and maintain the desired level of milk production. Horses and other animals also benefit from efforts to keep them cool during hot weather. Plants, particularly crops, also benefit from attempts to maintain their temperature in a more desirable range so as to prevent exposing the plants to freezing or very hot temperatures.
[0008] In addition to attempting to regulate or at least partially control the air temperature, substances are dispersed in an area to accomplish other objectives. For instance, the area where animals are raised or where they otherwise reside benefits from the dispersion of substances to kill flies and other pests and/or substances that can reduce the odor associated with the animals. Crops and other plants benefit from the dispersion of pesticides, nutrients and/or other beneficial substances onto the plants, on the ground where the plants grow or in the general area of the plants. Water and other fluids are commonly dispersed in construction sites or other dusty areas as a means of dust control. Areas also benefit from the dispersion of fire suppression substances either in anticipation of an approaching fire or to control a fire that is burning. Urban areas are known to benefit from the dispersion of antiviral agents and/or substances for controlling mosquitos, flies or other pests. Numerous other substances can be dispersed in an area to achieve certain, usually specific, benefits.
[0009] The use of a dispersing apparatus to disperse a substance over an area is generally well known. Outdoor areas where people gather commonly use misting apparatuses to disperse a very fine mist of water to cool the ambient air temperature. Ideally, such apparatuses are configured such that the mist is so fine that it substantially evaporates in the air before it contacts persons in the area to prevent those persons from getting wet. A common configuration for a misting apparatus comprises a source of pressurized water that is directed through a spray nozzle. To achieve the desired fine mist, a pump or other pressurizing device is utilized to pressurize the water and the nozzle is configured with a discharge that results in the fine spray. In addition to the requirement to pressurize the fluid, the water or other fluid that is used for the mist must be very clean, often filtered, to avoid clogging or damaging the spray nozzle. Due to the requirement of having a very clean, non-clogging fluid, most conventional mist sprayers are not suitable for dispersing substances other than water or substances that are completely soluble in water or other liquid. Conventional misting apparatuses are also not suitable for dispersing a substance over a large area, such as an area where cows are being raised, a large group of people are gathering or where crops or other plants are being grown. Use of such systems would require significant initial and ongoing costs to purchase a large volume of misters, pressurize the fluid and clean and/or replace nozzles as they become clogged.
[0010] One prior art livestock cooling apparatus, described in U.S. Pat. No. 6,705,599 to Terrell, et al., comprises an electrically-powered fan having a fan blade and fan motor mounted in a fan enclosure which is attached to a fan yoke that allows the user to change the angle of the fan enclosure and, as a result, the direction of the air stream created by the fan. The fan yoke connects to a drive shaft supported within a bearing means that is attached to a support means, which may be a structural member of a livestock protective structure, such as a barn or shade structure. The patent also describes use of a mist ring, which has a plurality of nozzles attached thereto, at the front or discharge opening of the fan enclosure for injecting water droplets into the air stream of the fan. A pump, connected to a pump motor, provides pressurized water to the nozzles that can result in a drench, mist or fog. The patent discloses the benefit of using very small diameter nozzles and supplying the water at high pressure to obtain extremely small water particles that results in cool animals with little wetting of the animal's hair-coat and virtually no wetting of the animal's bedding. U.S. Pat. Nos. 6,578,828, 6,675,739 and 6,883,251, each also to Terrell, et al., disclose livestock cooling systems that utilize the above-described cooling apparatus. As with the misting apparatuses, the cooling apparatus and systems of the aforementioned patents require high pressure pumps and small diameter nozzle openings and, as such, they are likely to have the same issues with regard to costs and clogging and being limited to spraying substantially pure water or other liquids or substances that are completely soluble in water or other liquid.
[0011] Improved sprayers and associated spraying systems for dispersing a fluid over a relatively large area have been developed and are in use. One such apparatus is the SMI® Polecat Evaporator available from SMI Evaporative Solutions of Midland, Michigan, which are commonly, but not exclusively, utilized to throw a water spray for producing snow or to evaporate away unwanted water. These and similarly configured sprayers atomize water for the spray with a plurality of nozzles, such as thirty such nozzles, at the discharge end of a powerful spray mechanism that is capable of throwing a spray over 200 feet from the discharge end of the apparatus. The nozzles are configured to introduce the atomized substance into the air stream created by the spray mechanism. As such, this type of sprayer requires a pump to supply pressurized fluid, such as an optimum operating pressure between 80 and 100 psi, to the apparatus. To avoid plugging the nozzles, such sprayers are typically used with one or more water filters to filter the water prior to the nozzles. For purposes of attempting to cool a large area, such as an area where cows, other animals or people are located, these sprayers have certain disadvantages, namely spraying too much water, plugging of the nozzles and requiring a pump and filter.
[0012] Another mechanism for atomizing water is a rotary atomizer, such as available from Ledebuhr Industries, Inc. out of Williamston, Mich. In general, rotary atomizers utilize have a two-stage atomizing process. Fluid enters the atomizer and is spun around the inside of the atomizer basket and then discharged out the atomizer through a holes on the side of the basket. The typical rotary atomizer does not require pressurized fluid, thereby eliminating the need for a pump, and does not have any nozzles that can be plugged, thereby generally eliminating the need to pre-filter the fluid. Another benefit of rotary atomizers is that they are typically better suited to atomizing substances which are not completely soluble.
[0013] What is needed is an improved apparatus for dispersing a substance over a large area. Preferably, such an apparatus should be configured to efficiently and effectively spray a substance over a large area to affect the temperature of the area, treat the area or otherwise beneficially affect the area. A preferred apparatus will not require the use of pumps to pressurize the fluid and will not have nozzles that are subject to clogging, thereby eliminating most filtering requirements. The preferred apparatus should be relatively inexpensive to manufacture, relatively easy to operate and be suitable for use in typical outdoor environments.
SUMMARY OF THE INVENTION
[0014] The dispersing apparatus of the present invention provides the benefits and solves the problems identified above. That is to say, the present invention discloses an improved apparatus for dispersing a substance over a large area, such as dispersing a cooling fluid over an area where people are gathered or where cows or other animals are located. The dispersing apparatus of the present invention can be utilized to disperse a wide variety of substances over areas where it is beneficial for people, animals, plants or the land itself. The present apparatus does not require the use of a high pressure fluid and does not use any nozzles, thereby eliminating, in most applications, the need for a high pressure pump and a filtration system. The dispersing apparatus of the present invention can be manufactured with readily available components, is easy to use and is suitable for most outdoor environments. In one embodiment, the dispersing apparatus of the present invention is particularly adaptable for use to spray water or other liquids over a stockyard or other large outdoor or indoor area where cattle or other animals are kept.
[0015] In a primary embodiment of the present invention, the dispersing apparatus generally comprises a ducted fan configured to create a strong air stream and a rotary atomizer configured to atomize a fluid and discharge the atomized fluid into the air stream so that it may be blown over and across a large area to cool, heat or provide other benefits to the area or to people and animals in the area. The ducted fan has a shroud with an intake end and a discharge end, a plurality of fan blades that are rotatably disposed in the shroud generally towards the intake end thereof and a motor that is operatively connected to the fan blades. The fan blades are configured to draw air into the shroud and produce an air stream that flows toward the discharge end of the shroud. The motor is connected to a source of power, such as an electrical panel or other source of electricity. The rotary atomizer is disposed inside the shroud generally towards the discharge end thereof and in fluid flow communication with the air stream. One or more conduits hydraulically connect the rotary atomizer to a source of fluid. The rotary atomizer is configured to discharge atomized fluid from the source of fluid into the air steam so as to produce a spray mist that is discharged generally over the large area. In a preferred embodiment, the dispersing apparatus has a tilting mechanism for tilting the ducted fan so as to vertically direct the discharge end of the shroud towards the large area and generally discharge the spray mist over the large area. The tilting mechanism can comprise a lever or like device operatively connected to the shroud so the user can manually tilt the shroud up or down to best achieve the coverage over the large area he or she desires. The preferred embodiment of the dispersing apparatus also includes an oscillating mechanism for oscillating the ducted fan in a generally left and right or back and forth direction. The oscillating mechanism is operatively connected to the shroud so as to sweep the discharge end of the shroud towards the large area and generally discharge the mist across the large area. The oscillating mechanism can comprise a motor connected to the source of power and a gear assembly that is operatively connected to each of the motor and the ducted fan. One or more brace members can be utilized to interconnect the rotary atomizer with an inner surface of the shroud to support the rotary atomizer inside the shroud. Preferably, the one or more brace members are configured to dispose the rotary atomizer in spaced apart relation to the inner surface of the shroud. The preferred dispersing apparatus also includes a screen at the intake end of the shroud to prevent large debris from damaging the fan blades or other equipment inside the shroud and to protect persons from being injured by the rotating fan blades. The screen must comprise a plurality of openings to allow the fan blades to draw sufficient air into the shroud to provide the desired dispersing of the spray mist.
[0016] Accordingly, the primary aspect of the present invention is to provide an improved apparatus for dispersing a substance over a large area that has the advantages discussed above and which overcomes the various disadvantages and limitations associated with prior art substance dispersing apparatuses.
[0017] It is an important aspect of the present invention to provide a dispersing apparatus that is configured to disperse a substance over a large area without requiring the substance to be pressurized and injected into an air stream through a plurality of nozzles.
[0018] It is also an important aspect of the present invention to provide a dispersing apparatus that is particularly configured to be used outside to disperse a substance of a relatively large area without being clogged by dirt, dust or other debris commonly found in outdoor environments.
[0019] It is also an important aspect of the present invention to provide a dispersing apparatus that is capable of dispersing a wide variety of substances over relatively large areas where the substance can benefit people, animals, plants or the land itself.
[0020] It is also an important aspect of the present invention to provide a dispersing apparatus that can be used to disperse cooling fluids, pesticides, deodorants, heated air and other substances over a relatively larger area.
[0021] Another important aspect of the present invention is to provide a dispersing apparatus that is readily adaptable for use to spray water, other liquids and/or various solids dissolved in liquids.
[0022] Yet another important aspect of the present invention is to provide a dispersing apparatus that is relatively inexpensive to manufacture, relatively easy to operate and suitable for use in typical outdoor environments, including areas where cattle or other animals are kept.
[0023] The above and other aspects and advantages of the present invention are explained in greater detail by reference to the attached figures and the description of the preferred embodiment which follows. As set forth herein, the present invention resides in the novel features of form, construction, mode of operation and combination of the above presently described and understood by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In the drawings which illustrate the preferred embodiments and the best modes presently contemplated for carrying out the present invention:
[0025] FIG. 1 is a left side perspective view of an apparatus for dispersing a substance over a large area configured according to a preferred embodiment of the present invention shown dispersing a substance;
[0026] FIG. 2 is a back perspective view of the first or intake end of the apparatus of FIG. 1 ;
[0027] FIG. 3 is a right side perspective view of the apparatus of FIG. 1 ;
[0028] FIG. 4 is a front perspective view of the second or discharge end of the apparatus of FIG. 1 ;
[0029] FIG. 5 is a rear perspective view of a rotary atomizer that can be utilized with the dispersing apparatus of the present invention;
[0030] FIG. 6 is a side view of the rotary atomizer of FIG. 3 ; and
[0031] FIG. 7 is a top plan view of a large area having a dispersing apparatus of the present invention being used to cool cattle kept in the area.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] With reference to the figures where like elements have been given like numerical designations to facilitate the reader's understanding of the present invention, the preferred embodiments of the present invention are set forth below. The enclosed text and drawings are merely illustrative of one or more preferred embodiments and, as such, disclose one or more different ways of configuring the present invention. Although specific components, materials, configurations and uses are illustrated, it should be understood that a number of variations to the components and to the configuration of those components described herein and in the accompanying figures can be made without changing the scope and function of the invention set forth herein. For instance, although the figures and description provided herein show certain shapes and configurations for the fan mechanism and rotary atomizer, those skilled in the art will understand that this is merely for purposes of simplifying this disclosure and that the present invention is not so limited.
[0033] A dispersing apparatus that is configured pursuant to a preferred embodiment of the present invention is shown generally as 10 in FIGS. 1 through 4 . The dispersing apparatus 10 generally comprises a ducted fan 12 and a rotary atomizer 14 for introducing an atomized substance into the air stream 15 created by the ducted fan 12 to produce a very fine spray, such as the spray mist shown as 16 in FIGS. 1 through 3 , that can be dispersed over a relatively large area, shown as 17 in FIG. 7 . In a preferred embodiment, ducted fan 12 comprises an elongated shroud 18 having a first or air intake end 20 and a second or discharge end 22 . The embodiments shown in the figures and discussed below utilize ducted fan 12 having a shroud 18 with a bell-shaped intake end 20 housing the fan blades 24 , best shown in FIG. 4 , with a generally round tubular discharge end 22 . Rotatably mounted inside the shroud 18 are, preferably, a plurality of fan blades 24 , best shown in FIG. 4 , that are sized and configured to draw air in through the intake end 20 and direct air out the discharge end 22 of shroud 18 . As will be readily apparent to those skilled in the art, the above-described configuration for shroud 18 is not required for the operation of dispersing apparatus 10 and modifications to the shape of shroud 18 can be made as desired by the manufacturer and/or user of dispersing apparatus 10 . As well known, the shroud 18 of ducted fan 12 is preferably configured to reduce losses in discharge volume and pressure (e.g., thrust if ducted fan 12 were used for propulsion). By varying the cross-section of shroud 18 , the velocity and pressure of the airflow out discharge end 22 can be varied as desired by the manufacturer or user of dispersing apparatus 10 to meet particular dispersing requirements.
[0034] In the preferred embodiment of the present invention, the fan blades 24 of ducted fan 12 are operatively connected to a fan motor 26 , which can be an electric or hydraulic motor, and are configured to move a relatively large volume of air through the interior of shroud 18 . Specifically, the fan blades 24 are configured to draw air in through the intake end 20 of shroud 18 and direct a powerful stream of air out through the discharge end 22 thereof. The configuration of fan blades 24 necessary to achieve movement of large quantity of air through shroud 18 and their relationship to a shroud or duct, such as shroud 18 , is generally well known within the art. Typically, but not exclusively, the fan motor 26 for ducted fan 12 will be fixedly mounted inside the shroud 18 , as shown in FIG. 4 . In one embodiment, the fan motor 26 for ducted fan 12 is a 25 hp electric motor connected to a source of electricity by wire(s) 28 , as best shown in FIGS. 1 through 3 .
[0035] For use in outdoor environments, such as corrals, pens and other animal holding areas, intake end 20 of shroud 18 will generally have a screen 30 , shown in FIGS. 2 and 4 , that substantially covers intake end 20 and is configured to prevent larger-sized debris being drawn into the shroud 18 and damaging fan blades 24 and/or other equipment inside shroud 18 . In addition, the screen 30 will prevent people from contacting fan blades 24 during operation of dispersing apparatus 10 , which would likely cause severe injury. However, the screen 30 should have sufficient number of appropriately sized openings 32 so the screen 30 does not significantly interfere with the ability of fan blades 24 to draw air into shroud 18 through intake end 20 . In one embodiment, screen 30 comprises is a metal mesh or mesh-like configured structure that defines a plurality of openings 32 , as best shown in FIGS. 2 and 4 , through which air will be drawn into shroud 18 by fan blades 24 . If desired, various other materials and configurations of screen 30 can be utilized.
[0036] Preferably, dispersing apparatus 10 will also include tilting mechanism 34 , best shown in FIG. 3 , that is operatively associated with ducted fan 12 so as to allow the user of dispersing apparatus 10 to vertically direct the discharge end 20 of shroud 18 so as to affect the upward or downward angle of the discharge end 20 and, therefore, the general direction spray mist 16 will travel over the large area 17 . In one embodiment, tilting mechanism 34 comprises a lever 36 mounted on shroud 18 that can be manually operated by the user to adjust the vertical tilt or angle of shroud 18 in a manner that directs the spray mist 16 generally upward, downward or horizontally from the discharge end 22 of shroud 18 . The tilting mechanism 34 can be configured to tilt the ducted fan 12 relative to a yoke 38 that supports the dispersing apparatus 10 on a support structure, which may be a building, canopy cover or the like or, preferably, a separate carriage or stand 40 such as shown in FIGS. 1 through 3 . The stand 40 can include a plurality of frame members 42 that support the ducted fan 12 , via yoke 38 , above the ground or other surface. In the preferred embodiment, the dispersing apparatus 10 also includes an oscillating mechanism 44 , also shown in FIGS. 1 through 3 , that is configured to oscillate the ducted fan 12 in a generally left and right direction relative to stand 40 so as to sweep the discharge end 20 of shroud 18 across the large area 17 where the spray mist 16 is generally desired so spray mist 16 will be generally discharged across the large area 17 . As known in the art, oscillating mechanism 44 can comprise a motor 46 and a gear assembly 48 that, respectively, provide the power to oscillate the yoke 38 , which is attached to and supports the ducted fan 12 , and pivotally interconnect yoke 38 to the stand 40 , as best shown in FIGS. 1 and 2 . Other means of powering oscillating mechanism 44 and pivotally mounting the yoke 38 on stand 40 will be readily apparent to those skilled in the art.
[0037] A example of a ducted fan 12 that could be suitable for use with dispersing apparatus 10 of the present invention, depending on the application desired for dispersing apparatus 10 , is the Super PoleCat available from SMI (referenced above). Various other high volume fans, whether commercially available or custom made, are likely to be suitable for use as ducted fan 12 for dispersing apparatus 10 of the present invention. In the embodiment shown in FIGS. 1 through 3 , the dispersing apparatus 10 also includes an electrical panel 50 attached to stand 40 and an electrical control box 52 attached to yoke 38 . Wires 28 interconnect the electrical panel 50 and control box 52 with the fan motor 26 and the motor 46 of oscillating mechanism 44 .
[0038] In the preferred embodiment of the dispersing apparatus 10 of the present invention, rotary atomizer 14 is mounted inside shroud 18 at or near the discharge end 22 thereof forward of fan blades 24 , as shown in FIGS. 1 , 3 and 4 . The rotary atomizer 14 , which is disposed in the air stream 15 created by fan blades 24 of ducted fan 12 , is selected to produce a fine mist 16 that can be blown the desired distance by the air stream 15 . In a preferred embodiment, the rotary atomizer 14 is mounted inside the shroud 18 with one or more brace members 54 that are sized and configured to dispose the rotary atomizer 14 in spaced apart relation to the inner surface 56 of shroud 18 . In one embodiment, best shown in FIGS. 4 , 5 and 6 , the rotary atomizer 14 comprises an 2 hp electric motor 58 , which is also connected to the supply of electrical power via electrical panel 50 and control box 52 , and a generally circular-shaped basket 60 that produces a radial spray pattern. Typically, basket 60 can be selected to have either a fine or coarse configuration, or others, for different types of mist 16 . A fluid conduit 62 , best shown in FIGS. 3 and 4 , connects the rotary atomizer 14 to a source of fluid 64 , such as the outdoor faucet shown in FIGS. 1 and 2 . In one use, the supply of fluid is a conventional low pressure water supply such as is commonly available from most municipalities. As with the ducted fan 12 , the motor 58 for the rotary atomizer 14 can be electrically powered, as shown, or it can be a hydraulic motor. In addition to selecting the configuration of the basket 60 , the user can also change the particle size produced by rotary atomizer 14 by changing its speed, with a slower speed producing larger droplets and a faster speed producing smaller droplets. Rotary atomizer 14 can have an electrical controller associated with the electrical panel 50 or control box 52 that allows the user to increase or decrease the speed of motor 58 while dispersing apparatus 10 is operating. An example of a commercially available rotary atomizer 14 that is suitable for use with dispersing apparatus 10 is Ledebuhr Industries' twelve inch dual stage rotary atomizer. Other rotary atomizers are also likely to be suitable for the dispersing apparatus 10 of the present invention.
[0039] The dispersing apparatus 10 of the present invention is particularly useful for cooling the ambient air temperature over a large area, such as the cattle holding area 17 shown in FIG. 17 , utilizing water as the substance. The inventor has utilized a pair of such dispersing apparatuses 10 at a dairy facility to cool ten acres approximately five degrees. The dispersing mechanism 10 can also be utilized to cool a large area 17 where people are gathered, such as a concert or an outdoor market, to reduce the temperature in that area 17 . In addition, dispersing apparatus 10 can be utilized to cool a relatively large outdoor area 17 where construction workers, farm workers or other people are working. For temporary use, a portable generator can supply the power and a tank can hold the water to be dispersed. Dispersing apparatus 10 can also be utilized to disperse a deodorant, pesticide or antiviral substances (among many others) over a large area 17 . The dispersing apparatus 10 can also be utilized to create a fog-like blanket over a crop growing area 17 to keep the crop cool to slow/control growth of the plants for better quality, as is known to be beneficial for alfalfa and certain other crops, particularly in greenhouses and the like. If desired, the dispersing mechanism 10 can also be utilized for fire suppression by dispersing a fire retardant on a large area 17 where a fire is approaching or where it is burning. The dispersing mechanism 10 can also be used on cold and or foggy days to heat a large area 17 and clear the fog to benefit people, animals or plants in the area 17 , such as a dairy, vineyard, orchard or the like, by warming the ambient air. Heated air can also be utilized for drying highways and clearing fog on a road to make vehicle travel on the road safer. The substance to be dispersed by dispersing apparatus 10 can be kerosene or other flammable substance that is atomized and then misted out the discharge end 22 of shroud 12 to produce, when lit, a warming flame that is more efficient than present large area heaters due to the atomization of the fuel. As will be readily apparent to those skilled in the art, the materials and/or coatings selected for the various components of dispersing apparatus 10 should be selected for their relative durability, corrosion resistance and long life. If desired, the dispersing mechanism 10 of the present invention can also be utilized to produce snow with less expense and equipment than prior art snow-making systems.
[0040] Although the preferred embodiment of the dispersing mechanism 10 does not require a pump or filter there may be uses when such components are required or beneficial. For instance, the user may desire to utilize a pond, lake or other surface water as the source of fluid. This may be particularly beneficial in an emergency to fight a fire. In such circumstances, a low pressure pump will be required to draw fluid from the source and a screen or filter, as may be applicable, should be used to prevent damage to the pump and/or rotary atomizer 14 . As set forth above, however, there is generally no need to utilize a high pressure pumps to pressurize the fluid or to use very fine screens or filters to avoid plugging the nozzles of any nozzle-type spraying mechanism (which are not utilized in the dispersing apparatus of the present invention).
[0041] In use, a person connects the fan motor 26 of ducted fan 12 and the motor 58 for rotary atomizer 14 to the source of power (e.g., electric or hydraulic) and the conduit 62 to the source of the fluid to be sprayed. The discharge end 22 of shroud 18 is then pointed in the direction of the large area 17 to be affected (e.g., cooled, heated, treated, or etc.). Once the dispersing apparatus 10 is activated, fluid will be atomized by the rotary atomizer 14 and the resulting mist 16 will be blown toward the area 17 by the air stream 15 generated by the ducted fan 12 , which can be 55 mph or more. The dispersing mechanism 10 will disperse the mist 16 toward and over the area 17 providing the desired benefits.
[0042] While there are shown and described herein a specific form of the invention, it will be readily apparent to those skilled in the art that the invention is not so limited, but is susceptible to various modifications and rearrangements in design and materials without departing from the spirit and scope of the invention. In particular, it should be noted that the present invention is subject to modification with regard to any dimensional relationships set forth herein and modifications in assembly, materials, size, shape and use. For instance, there are numerous components described herein that can be replaced with equivalent functioning components to accomplish the objectives of the present invention. | An apparatus for dispersing a spray mist over a large area that cools or provides other benefits to the area or to people and animals in the area. The dispersing apparatus comprises a ducted fan having a shroud with a plurality of fan blades disposed inside the shroud near its intake end and a rotary atomizer positioned inside the shroud towards its discharge end and in the air stream created by the fan blades. The fan blades are powered by a motor inside the shroud. A tilting mechanism tilts the discharge end of the shroud up or down to aim the spray mist and an oscillating mechanism pivots the ducted fan to discharge the spray mist generally across the area. The rotary atomizer discharges an atomized substance, which may be water, pesticide, deodorant, liquid fuel, fire retardant or a wide variety of other materials, into the air stream. | 0 |
INTRODUCTION AND BACKGROUND OF THE INVENTION
This invention relates generally to the field of the manufacture of felt webs, and is more particularly directed to apparatus for making bonded felt webs, the apparatus being suitable for putting the method into practice.
Techniques which are already known for making sheets or webs of fibres agglomerated by bonding use materials specially adapted in view of the nature of the fibres to be utilised, taking note in particular of the fineness, of the length, of the dynamometric resistance, and of the elasticity. There are thus employed, especially, carded webs in a vast range of varieties of non-woven or felt textiles, of which the fibres are bonded, either by means of liquid or pulverulent bonding agents acting under the effect of heat, or by the intervention or mechanical means, such as those which work for the trapping and in view of the interlacing of the fibres. Sometimes the two methods are put into practice together in order to obtain the desired resilience.
The present invention has as one object to mitigate some of the disadvantages of the processes described above, and has as another object to provide apparatus for making non-woven webs which allow the utilisation of fibres of all kinds and characteristics, which may be treated separately or in mixtures.
BRIEF SUMMARY OF THE INVENTION
The method performed by the apparatus according to the invention essentially comprises the steps of depositing a layer of fibres in the form of flocks upon a feeding support, passing this layer between two fluted rollers, then carding the said layer by means of a drum furnished with points or saw teeth, or the like. Following this carding operation the separated fibres are recovered in a chamber where they are mixed intimately with fine pulverulent resins. The mixture of fibres and resins is maintained in suspension in air in the chamber during the lapse of a period of time which is regulatable by virtue of a circulation of air in the chamber. This circulation of air puts the interior of the mixing chamber under a sub-atmospheric pressure and deposits the fibres mixed with resin upon a perforated support. The wadding layer thus constituted is then levelled in respect of its thickness then compressed, and finally transported towards positions for subsequent treatment.
FURTHER DESCRIPTION AND ADVANTAGES OF THE INVENTION
According to an optional feature of the invention there may equally be provided in addition to the fibres, before or after their mixing with the bonding resin, charges of heavy powders such as sulphate of baryta, micas, bitumens, etc.
The invention has also as an object the provision of an apparatus for putting into practice the method described above, constituted essentially by a feeding device, by two fluted rollers, by a carding drum, by a mixing chamber, by a device for sprinkling resins supplied to the mixing chamber through a channel, by a collecting device which is perforated and forms the lower part of the mixing chamber, by a suction chest disposed below the collecting device and connected through the intermediary of a duct to a fan, by a device for equalising the thickness of the non-woven layer, and finally by a flattening roller.
According to one feature of the invention the upper part of the mixing chamber is closed, over a portion of its length, by a perforated metal plate.
According to another feature of the invention the device for equalising the thickness comprises a perforated drum and a segment of a cylinder mounted co-axially within this perforated drum, this segment being regulatable in such a manner as to present its opening at a distance which is more or less great from the perforated collecting device.
The invention may be well comprehended with the aid of the following description with reference to a preferred embodiment, given by way of non-limitative example and explained with reference to the accompanying schematic drawing.
BRIEF DESCRIPTION OF THE VIEW IN THE DRAWING
The single view in the accompanying drawing is a schematic longitudinal sectional elevation of an apparatus according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In conformity with the invention and as shown in the accompanying drawing, the apparatus of the invention is constituted essentially by a perforated feed conveyor 1 on which is disposed a layer 2 of fibres in the form of flocks, by two fluted rollers 3 and 4, by a carding drum 5 provided with points 6 or saw teeth or the like and adapted to feed the separated fibres into a mixing chamber 7. The latter is provided in its upper part with a sprinkler 8 whereby resins are fed into the mixing chamber 7 through a channel 9. The lower part of the mixing chamber 7 is closed by a perforated collecting conveyor 10, underneath which is disposed a suction chest 11 which is connected through the intermediary of a duct 12 to a suction fan 13. At the end of the mixing chamber 7 remote from the carding drum 5 there is provided a levelling device 14 for equalising the thickness of the resulting wadding layer 15, and downstream of this device 14 there is a flattening roller 16.
The upper part of the mixing chamber 7, between the zone adjacent to the sprinkler 8 for supplying resin and the levelling device 14 for equalising the thickness, is closed by a perforated metal plate 17 permitting the entry of air into the said chamber 7, and the portion remaining between the perforated metal plate 17 and the fluted roller 4 is formed by a plain metal plate 18 delimiting a narrow archway above the carding drum 5.
The levelling device 14 for equalising the thickness of the wadding roller 15 is constituted by a perforated drum 19 in which is disposed co-axially a cylindrical segment 20 having an opening 21, this segment 20 being regulatable in such a manner as to present its opening 21 at a more or less great distance from the perforated collecting conveyor 10.
The suction chest 11 is provided with openings 22 and 23 and 24, which are in communication with the duct 12 connected to the fan 13, permitting a regular suction over the whole surface of the perforated collecting conveyor 10 passing above the suction chest 11.
The fan 13 withdraws the air sucked into the chamber 7 and expels it partially through a duct 25 connected to a second suction fan (not shown) which returns the air to the atmosphere directly or through a filtering installation. Another portion of the air leaving the fan 13 is expelled through a channel 26, of which the outlet opening is regulatable by means of a flap 27 and which feeds this air into the chamber 7.
The degree of vacuum in the chamber 7 and the period of suspension therein of the mixture of fibres and resins are regulated by changing the performance of the fan 13 by means of draught registers 28 and 29, disposed respectively at the discharge from the fan 13 and in front of the duct 25.
The closing of the chamber 7 at the level of the levelling device 14 is effected by means of a flap 30 articulated at a pivot point 31 upon the upper part of the chamber 7, and urged against the perforated drum 19 by means of a counterpoise 32.
The illustrated apparatus for making non-woven webs in conformity with the invention functions in the following manner: The feed conveyor 1, carrying a layer 2 of fibres in the form of flocks, feeds these fibres between the two rollers 3 and 4, the latter pressing the fibres in the direction of the roller 3, both of these rollers being fluted. At the exit from between the rollers 3 and 4 the layer 2 is seized by the points 6 of the carding drum 5, which rotates at a tangential speed, preferably regulatable, between 600 and 2500 meters per minute, and which projects the separated fibres through the narrow archway formed below the plain metal plate 18 and into the mixing chamber 7. In this latter the fibres come into contact with resins dispersing from the channel 9 of the sprinkler 8, and the resins and fibres become intimately mixed. This mixture of fibres and resins remains in suspension during a period which is regulatable by action upon the suction arrangement with the aid of the draught registers 28 and 29, which allows regulation of the degree of vacuum prevailing in the interior of the chamber 7. As the metal sheet 17 is perforated it allows a circulation of the air in the direction from the ambient atmosphere into the chamber 7, and thus maintains the degree of vacuum substantially constant. The removal of the air by the fan 13, through the duct 12, is effected with the aid of the suction chest 11 disposed underneath the perforated collecting conveyor 10 and connected to the duct 12 by the openings 22 and 23 and 24. The air extracted through these openings is partially returned through the channel 26 into the chamber 7, the excess of the volume of air passing by the fan 13 being extracted by a second suction fan (not shown) at the exit from the duct 25.
The fibres coated with resin are deposited, under the effect of the suction which exists above the suction chest 11, upon the perforated conveyor 10 and accumulate there progressively. The wadding layer 15 thus constituted, of which the thickness and the weight per square meter are regulatable, either by action upon the linear speed of the conveyor 10 with a constant rate of feed to the drum 5, or with a constant speed of the conveyor 10 by action upon the rate of feed upstream of the drum 5, arrives in front of the levelling device for equalisation of the thickness. This device 14 has for its object to even out any irregularities in the thickness of the wadding layer 15, and to determine the final thickness of the felt to be obtained as well as its weight per square meter. Thus any fibres which are at a level above the opening 21 of the cylindrical segment 20 are recirculated by a circulation of air within the chamber 7. The wadding layer 15 is then compressed by the perforated drum 19 and is then flattened by the roller 16 and leaves the felt-making apparatus in order to be transported towards stations for subsequent treatment.
According to another optional feature of the invention there may be added at the upstream or downstream side of the bonding resin sprinkler 8 one or more devices for dispensing charges of heavy powders such as, for example, sulphates of baryta, micas, bitumens, etc.
The apparatus in conformity with the invention can easily be introduced into a manufacturing installation without involving great cost, and it permits the treatment of fibres of all kinds and of textile or animal or vegetable or mineral origins, whatever their inherent characteristics may be.
Moreover, with the apparatus of the invention, a very large linear production is possible, for example of the order of 15 to 20 metres per minute; as the fibres become deposited in all directions and relative orientations there can be obtained dynamometric resistances which are equal in all directions; because the mixing process is slow and efficient there can be achieved an important economy in the use of bonding resins, and the density of the felts can be varied within a wide range, for example between 5 and 80 kg/m 3 .
Modifications are possible within the scope of the invention as defined in the following claims, notably with regard to the constitution of the various components of the apparatus. | The disclosure is of apparatus for making a bonded felt web, wherein fibre flocks are carded and the separated fibres are mixed with powdered bonding agent and floated in air at sub-atmospheric pressure, collected on a perforated conveyor, then levelled and flattened. | 3 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to a roof bolt bearing plate and method for use in underground mining operations. In one aspect, this invention relates to a roof bolt bearing plate and method for supporting the roof in an underground coal mine.
2. Background
Mining operations today use roof bolt bearing plates to support the roofs in underground mines.
Support integrity for the mine roof provides a safe work place and maintains the important safety required for working in an underground mine. Failure to control the stability of the roof of the mine leads to the majority of serious or fatal accidents occurring in underground mines in the United States today. Accidents involving major cave-ins of mine roofs have become less prevalent, but a fatal accident can occur from the falling of large rock from the roof of a mine. Accordingly, mine roof control systems must provide safety integrity for personnel working in the mines. The Mine Safety and Health Administration (MSHA) of the United States government enforces mine safety standards, including roof support standards, and inspects mine roof control plans and practices in the mining industry.
Enhanced safety and roof support have reduced serious accidents involving major roof cave-ins substantially since the 1970's. Compliance with MSHA standards now requires underground mines to have a roof control plan in place, and such plan includes “primary roof support.” Primary roof support includes abatement provisions designed to prevent a roof cave-in by sealing the lowest layers of a mine roof to upper strata of rock.
Methods for attaching lower level rock strata to upper layers use a roof bolt and epoxy resin to seal layers of rock strata. Roof bolts vary in length and size but are typically one-half inch or more in diameter and 30 inches to 12 feet long or longer in overall length. A motorized roof bolter places a roof bolt in a roof ceiling. Positioned in the front, unprotected face of the mine, a drilling mechanism drills several feet up through the mine roof. After a hole is placed in the roof, an epoxy resin in a pliable plastic tube is inserted in the hole. Next, a roof bolt is placed in the hole, and the placing of the roof bolt tears the packaging for the epoxy resin and mixes the resin to the bolt itself and the surrounding rock layers. The epoxy resin typically “sets up” or hardens within a matter of seconds, and the bolt and rock layers are sealed to each other.
In most underground mining situations, a roof bolt is placed approximately every four feet in the mine. Accordingly, placement of the roof support is a major undertaking and a major source of expense for the mine operator. Despite the cost, roof bolt and epoxy combinations are the conventional means for providing primary roof support and meet the requirements promulgated by MSHA and various state enforcement authorities.
INTRODUCTION TO THE INVENTION
Roof plates available commercially today can be viewed as severely limited with respect to the ability to compress the roof strata surrounding a roof bolt and adjacent areas.
Saab U.S. Pat. No. 5,207,535 discloses a mesh screen over a threaded end of a rock bolt. The Saab device is not used to pressurize the roof surrounding the roof bolt or compress the broken and loose strata. Saab does not support the roof but only the mesh, and the mesh supports the loose rock. Saab does not prevent the rock from breaking away from the immediate area of the bolt. The flat design and the split-leg portions do not support the roof under any type of pressure.
Wilcox U.S. Pat. No. 4,518,282 discloses a square plate for flat roof conditions. As a square or rectangle plate, the Wilcox plate leaves sharp edges and corners protruding downward, thereby causing a hazard to persons if the plate is installed in uneven areas of the roof. The outer edge of the Wilcox type plate turns downward and pulls the plate away from the roof. In spite of the size of the plate, a large portion of the intended area is left unsupported by the bearing plate.
Stankus U.S. Pat. No. 5,769,570 discloses a square plate used in conjunction with a cable bolt. The Stankus type plate shows the center protruding downward to form a cone shape away from the roof face. The Stankus plate uses a washer to mate with the surface of the plate and the bolt head.
Robertson US 2002/0028113 A1 discloses a plate used as a secondary roof support in conjunction with the primary roof support. Robertson's plate is convex from the center to the plate to the outer edge. Robertson's plate has an umbrella effect when used in an area of uneven roof. The center is pushed beyond the level plane and causes the outside rim to protrude down and away from the roof leaving only the center contacting the roof.
Payne U.S. Design Pat. No. 275,452 and Cassidy U.S. Design Pat. No. 301,687 disclose a plate of one plane.
Francovitch U.S. Pat. No. 4,520,606 discloses in the construction field a water tight seal to the roof of buildings. The Francovitch device could not be used to support the roof in underground mines.
Simpson U.S. Pat. No. 3,918,233 joins panels for roof and walls in the construction field.
Villaescusa U.S. Design Pat. No. 388,193 discloses a plate with minimal contact to pressurize the roof when installed. The two sides are punched out to accept a “J” hook which leaves even less of the area on the sides actually to contact and pressurize the roof. A hump on all four corners remains off the roof when the plate is installed and serves no purpose in supporting or pressurizing the surrounding roof at the bolt. The Villaescusa plate allows air to concentrate on the base of the bolt and allows a so-called weathering effect to take place and leave the entire area unsupported and dangerous.
Lemke U.S. Pat. No. 4,987,714 discloses a device used in the construction field for securing roofing materials and making a water tight seal. The Lemke device is building material hardware and could not be used as an underground roof support in the mining industry.
Durget U.S. Pat. No. 3,224,202 discloses a filler to contact the roof and conform to the roof conditions. The Durget type of roof bolting is very expensive and time consuming.
Roof plates available commercially today can be viewed as severely limited with respect to personnel safety because of the plate's sharp edges and corners, which protrude downward when in uneven areas of the mine.
New apparatus and method are needed to provide a roof bolt plate which: a) will securely contact the roof and compress the roof to stabilize the area immediately adjacent to the roof bolt, and b) will not bend down from the roof, creating a hazard to personnel.
Accordingly, novel roof bolt plate apparatus and method are needed to overcome the drawbacks attributable to traditional roof bolt plates used in underground mines today.
Accordingly, new mining roof bolt plate apparatus and method are needed to overcome the deficiencies found in conventional systems.
It is an object of the present invention to provide novel roof bolt bearing plate apparatus and method for providing a roof support system in an underground mine.
It is an object of the present invention to provide novel roof bolt plate apparatus and method that will pressurize the roof and maintain constant pressure on the roof surrounding the roof bolt.
It is another object of the present invention to provide a safer and less hazardous roof bolt plate with a rim that bends upward, even on irregular surfaces, leaving no sharp edges or corners that protrude downward and can injure workers.
It is another object of the present invention to provide a roof bolt bearing plate apparatus and method that will maintain more even pressure on the roof by compensating for uneven roof conditions and to provide a roof bolt bearing plate that will not be loosened when passing equipment comes in contact with the plate or bolt head.
It is a further object of the present invention to provide a roof bolt bearing plate apparatus and method that will ensure proper installation by enabling the roof bolter to determine immediately the quality of anchorage into the upper strata as soon as a bolting machine is lowered from the roof bolt.
It is a further object of the present invention to provide a roof bolt bearing plate that will form a cone shape around the base of the roof bolt and eliminate the weathering effect by compressing the roof bolt and preventing air from deteriorating the area of the roof adjacent to the roof bolt.
These and other objects of the present invention will become apparent from the detailed description which follows.
SUMMARY OF THE INVENTION
The apparatus and method of the present invention provide novel method and device for primary roof support in an underground mine. The apparatus and method of the present invention provides roof support in an underground mine including a round, dome-shaped support member having an extended lateral surface for contacting an inside roof of an underground mine and a center aperture in the support member for accommodating a roof bolt such that the roof bolt can be passed through support member to secure the support member to the roof of the underground mine. A round, dome-shaped plate of preferred size and thickness preferably is adaptable to changing roof conditions in an underground mine and provides primary mine roof support. The round dome-shaped apparatus and method of the present invention increase the bearing surface in the positive contact area. The novel plate and method stabilize the immediate roof in an underground mine and hold constant pressure on the surrounding roof in all directions.
The apparatus and method of the present invention provide a primary mine roof support and stabilizing system to accommodate adverse weathering. Weathering is when the immediate roof around the roof bolt deteriorates after time and falls to the mine floor leaving the area unsupported by the roof bolts.
The apparatus and method of this invention provides a device for primary mine roof support which decreases the amount of injuries imposed on primary mine support members by producing a dome-shaped plate, unlike square or rectangular ones. The dome-shaped plate does not bend away from the roof and eliminates the hazard of mine support members hitting the sharp corners of bent plates.
The apparatus and method of the invention provides a primary mine support system which will apply equal support in all directions of the roof. A uniform pattern of roof bolting is essential for proper roof control. When installed in this manner, the roof bolting compresses the lower roof strata and creates a beam like effect that helps support the upper layers of roof.
The apparatus and method of the present invention provide an apparatus for primary mine roof support having a recessed center to reduce the possibility of contact with persons passing under the roof bolt head.
The apparatus and method of the present invention provide easier installation for the operator of the roof bolt machine. The operator monitors the bolts anchoring in the roof as the operator lowers the roof bolt machine away from the head of the bolt. Accordingly, the novel apparatus and method of the present invention serve to reduce personnel difficulty involved in transporting the device, so as to increase the likelihood that the device will be used by mine employees.
The apparatus and method of the present invention overcomes the disadvantages inherent in prior art methods and devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the points of contact between the safety plate and the roof of the underground mine.
FIG. 2 shows Section A—A of FIG. 1 .
FIG. 3 shows the general placement pattern of roof bolts in an underground mine.
FIG. 4 shows a variation of the safety plate as an oval or elliptical plate that can be used as an alternative to the round plate when required.
FIG. 5 shows Section B—B of FIG. 4 .
FIGS. 6 and 7 show the comparison between the square or rectangle plates to the safety plate (round dome-shaped plate) of the present invention.
FIGS. 8 and 9 show the safety plate before and after the compression of the plate take place.
FIG. 10 shows an alternate model of the safety plate containing rib for extra strength.
FIG. 11 shows Section A—A of FIG. 10 .
FIG. 12 shows the actual cross sectional view of the roof, roof bolt, epoxy resin, and the safety plate.
FIG. 13 shows a plate pushing on the roof at 30 to 45 degree angles in all directions around the plate and straight up the center.
FIG. 14 shows the safety plate and locations of the “J” hook hangers.
FIG. 15 shows Section B—B, a one quarter cut away view of FIG. 14 .
DETAILED DESCRIPTION
In the mining of coal today, mining companies are finding the need to provide for enhanced safety and working conditions for the removal of larger and larger volumes and weights of mined material out of the mine. Apparatus and method must operate safely in the mine environment which typically subjects the miner personnel to a harsh and hostile environment.
In the mining of coal, particularly but not limited to coal strip mines, many coal seams are exposed and/or identified which have a low vertical seam height. By low vertical seam height is meant less than standing room. The low coal seam vertical height makes it extremely difficult or impossible to recover the coal by conventional deep mining equipment and techniques. The low coal is left behind when the cover over the seam is too high to mine the coal by strip mining techniques. Moreover, since the vertical height of these coal seams is so low, it is extremely difficult, if not impossible, to mine the low coal with people in the shaft.
It is therefore more imperative to provide more effective and safe roof bolts to protect miner personnel called to mine low coal.
In underground mining, and particularly in, but not limited to, underground mining wherein the vertical work space affords less than standing room, physical tasks are made more difficult by the confined spaces and constraints imposed by the underground mine. Although the apparatus and method of the present invention are not intended to be limited by particular dimensions in a low-coal mine, physical movements and activity are made significantly more demanding in low seam mining, e.g., less than 48 inches in vertical height.
When miners work to remove material from the mine in low coal, and when the miners apparatus is called upon to extend and retract in the mine, e.g., in conjunction with the continuous miner, the roof bolt plates must be constructed in the confining spaces and constraints within the mine, and conventional roof bolts and support apparatus are severely lacking in the areas of accommodating the difficult physical activities found in the confining spaces or constraints in the underground mine in low coal. The novel apparatus and method of the present invention facilitate rapid and flexible working conditions in the underground mine and increase mine prodcutivity.
Traditional roof bolt plates typically have a square or rectangle shape. The square shape causes sharp edges and protruding corners that cause a hazard to people if the plate is installed in an uneven area of the roof.
The roof of a mine is not a flat smooth surface. Grooves are left in the roof from the cutting machine bits, and ledges are formed from the rock falling and inconsistent operators. As the machine cuts the coal, a cutting bit scrapes the roof at different pressures and leaves different depths of gouges and ledges in the roof.
When a flat plate is used to support the roof in an underground mine, the center of the plate pulls up into the grooves and causes the outer edges to protrude downward. The flat plate has been found to leave a large percentage of the plate ineffective and to cause a hazard to persons in the lower coal seams.
Nearly every person working in the low seam mines has been injured to some extent by the plates that have the sides and corners protruding downward. The plate of the present invention will not protrude downward leaving a sharp edge to harm anyone, when the center is pulled into the grooves. The plate of the present invention has an outer rim which will stay tight to the roof and conform to the uneven areas. Square and rectangle plates that are not domed have a tendency to become loose when brushed by passing equipment and in turn are ineffective. The plate of the present invention will not become loose easily because of the constant pressure and conforming that takes place when the plate is tightened to the roof.
The apparatus and method of the present invention provide a novel roof bolt plate including a round, dome-shaped plate of preferred size and thickness adaptable to changing roof conditions in an underground mine. Novel plates are used in conjunction with various types and sizes. Novel plates of the present invention are made of metals now produced commercially. The plates are manufactured for the use of cable hangers and/or “J” hooks. A round dome-shaped design increases the bearing surface because of the positive contact area.
The novel rounded plate of the present invention provides a center of the plate recessed to a certain specified degree so that when the bolt and plate are installed, the outer rim of the plate contacts the roof first, and then as the bolt is tightened against the mine roof, the entire area around the bolt is compressed. The novel plate stabilizes the immediate roof by holding constant pressure on the surrounding roof in all directions. The novel plate design also eliminates a so-called weathering effect. Weathering is when the immediate roof around the roof bolt deteriorates after time and falls to the mine floor leaving the area unsupported by the roof bolts.
The recessed area in the center of the plate has a number of important benefits further to applying constant pressure to the outer rim and center of the novel plate. The recess also is useful in determining the quality of installation and the movement of the roof after the bolt has been installed by comparing the head of the bolt to the raised portion of the plate. The recess also protects the head of the bolt from possible damage done by passing equipment.
The novel roof bolt plate is substantially round instead of rectangular or square. The novel configuration increases the square inch coverage in all directions of the installed bolt. The plate is indented in the center with a through hole of different sizes for bolt insertion. The center indentation of the novel plate is displaced in structure lower than the outer rim so that the outer rim contacts the roof surface first. The lower center indentation provides the advantage when the bolt is installed, pushed to the roof, and tightened. A positive tension on the outer rim applies against the roof and the center of the plate against the roof. The indentation conceals some of the head of the roof bolt and aids in preventing damage to the bolt from equipment or harm to persons when passing under the installed bolt. The novel plate is punched out for the use of “J” hooks to hang cables. Plates for underground roof bolting support the roof and are punched out for the “J” hook or a similar device for hanging cables and wires.
The novel plate of the present invention provides novel outer rim contact. The rim of the plate is only as wide as the thickness of the material used to produce the plate. When the plate is installed, the outer rim contacts the roof first, and then as the bolt is being pushed to roof, the rim of the plate spreads out away from the center and pushes upwards on the roof at 30 to 45 degree angles. When the center of the plate is pushed to the roof and the bolt is set or tightened, the plate is seated firmly against the roof.
The apparatus and method of the present invention provide more coverage and support than conventional roof bolt plates. When the bolt is installed, the plate acts like a lock washer holding pressure on the roof and the head of the bolt. By holding tension on the roof and bolt head, the roof is compacted around the base of the bolt and eliminates the so-called weathering effect. The weathering effect when the roof deteriorates around the base of the bolt after time and falls to the bottom leaves the area unsupported and illegal. The novel plates of the present invention are made in a round or ellipse shape, although round is preferable because of the equal coverage and support in all directions.
It has been found that the indented center of the present invention provide further important advantages including to conceal and protect the head of the bolt from damage by passing equipment and further to prevent injuries caused by low hanging bolt heads. The bolt head is recessed in the center of the plate to a certain degree, which reduces the possibility of contact with persons passing under the bolt head. With visual observation, it is possible to determine if the roof was moving or the bolt has lost its anchorage, by noting the distance from the very end of the bolt head in comparison to the lower portion of the plate. It has been found to be particularly helpful when the bolt is being installed. The operator of the roof bolting machine is provided with the ability to determine when the bolts are anchoring in the roof as the operator lowers the machine away from the head of the bolt. If the plate pushes the bolt head downward, the bolt is not secured in the roof properly and the operator installs another bolt to replace the failed bolt, because of the lock washer effect. A machine bolt would show similar actions if the threads were stripped off of the bolt or nut and tightened on a lock washer.
Plates having a flange on the outside edge running parallel with the roof push perpendicular to the roof and compress the roof directly above the plate. Most of the pressure is in the center of the plate because the outside will bend away from the roof, as the center is being pushed. Square and rectangular plates have a tendency to bend away from the roof as they are being tightened in irregular or uneven roof. When the bending away happens, a large percentage of the coverage and support are lost. Moreover, the plate then has protruding sharp edges and corners facing downward, and becomes dangerous to the persons moving around the mine, especially in lower seams of coal. Many injuries have been caused by these hanging plates. Miners who have worked in low coal testify to injuries from sharp corners and edges from square and rectangle plates because they become loose with bumping by equipment passing under and brushing against the plate or bolt head. In fact, one test, which a coal mine inspector performs, is to hit the plate on the side with a hammer to test its tightness. If the plate is loose or becomes loose with the test, the bolt should be replaced and the inspector can insist on the replacement or repair of this bolt, which procedures are very expensive and time consuming.
The plate and method of the present invention do not leave sharp corners or edges because of the dome-shape and the rim forced into or flush with the roof. The novel equipment of the present invention is directed over the plate and bolt head and will be not dislodge and loosen. It has been found that the test the inspectors perform with a hammer does not loosen the novel plate of the present invention.
All underground mines are required to have a “roof control plan.” The roof control plan dictates the minimum required roof support systems. All materials (roof bolts and roof plates) must be approved by MSHA (Mine Safety and Health Administration) before they can be used in underground mines as a primary roof control system. Anything above and beyond the minimum plan can be used without approval, which is called a supplementary system. The plate of the present invention will be used as a primary support and will require testing by MSHA.
Referring now to the drawings of the figures, the following identifying numerals list the items being references in the several figures.
2 . Shows the aperture where roof bolt is installed into the plate, before installation in the mine roof.
4 . Shows the recessed area in the roof bolt plate. This is the area that the bolt head will be recessed in the plate after the bolt is installed and compressed to the mine roof.
6 . Shows the outer rim and first area of contact to the mine roof.
8 . Shows how the pressure is applied to the plates outer rim when an upward force is applied to the center of the plate.
10 . Designates the round dome shaped roof bolt plate.
12 . Shows a square roof bolt plate.
14 . Shows the rectangular roof bolt plate.
16 . Shows the elliptical or oval shaped roof bolt plate.
18 . Shows the mine roof, some with cutting machine grooves.
20 . Shows the area of the roof pressurized by the roof bolt plates.
22 . Designates the roof bolt.
24 . Coal face or the area where the coal is being extracted.
26 . Coal rib, the sides of the entries. That area is left standing to support the roof and direct ventilation.
28 . Epoxy resin in a pliable plastic tube, made up of two equal parts, one the resin and the other the hardener, separated by a thin partition.
30 . Immediate roof strata.
32 . Predrilled hole.
34 . Upper strata.
36 . Aperture for “J” hooks.
38 . Strengthen ribs. For extreme roof conditions.
40 . Directions of pressure applied to the roof.
Referring now to FIG. 1 , a sectionalized view A—A is shown of the contact area of mine roof 18 and safety plate 10 . The first contact will be outer rim 6 , and then center 4 will be forced to the roof 18 by the installation of a roof bolt 22 . Safety plate 10 maintains pressure on mine roof 18 immediately adjacent to the roof bolt 22 and in all directions from that area.
FIG. 2 shows Section A—A of FIG. 1 .
FIG. 3 shows the general pattern of the placement of roof bolts 22 . The irregular pattern of square 12 and rectangle shaped plates 14 compare to round safety plates 10 .
Referring now to FIG. 3 , a consistent and uniform pattern is shown to form an essential part for proper and effective roof control.
FIG. 4 shows the variations of the safety plate 10 of the present invention.
Referring now to FIG. 4 , an elliptical/oval plate 16 can be used as an alternative to the round plate 10 when required. In areas of the mines where channels and cross bars are used to assist in the support of the roof or in areas in need of repairs, the oval plate 16 can be inserted between the crossbars and in channels when additional reinforcement is required. Sectionalized views A—A and B—B show the same beneficial dome-shape that the round plate 10 offers.
FIG. 5 shows Section B—B of FIG. 4 .
FIGS. 6 and 7 show the edges of safety plate 10 of the present invention and how it operates to hug the roof.
Referring now to FIGS. 6 and 7 , the plate 10 of the present invention eliminates the hazards associated with the protruding edges of the conventional plates. As the center of the rectangular plate 14 is tightened to the roof of the mine, the edges of the plate 10 bend downward from the roof 18 , leaving sharp edges and corners that protrude. This condition creates a hazard for workers moving about the mine. Often times, machine operators moving through the mine in a sitting position must tilt their heads even then missing the roof 18 by just inches.
FIGS. 8 and 9 show a plate 10 pushed to the roof and compressed.
Referring now to FIGS. 8 and 9 , as the dome-shaped plate 10 is bolted to the roof, the outer rim contacts the roof first 6 . When the outer edge is tight, the center starts to compress 4 , flattening the plate out. The plate 10 continues to pressurize the roof until the center of the plate is firmly seated against the roof. With the safety plate 10 of the present invention, the plate actually spreads out, conforming to the contours of safety plate 10 .
FIG. 10 shows the alternate model of safety plate 10 of the present invention containing strengthening ribs 38 .
Referring now to FIG. 10 , strengthening ribs 38 are used, for example, in extraordinary roof conditions where a stronger plate is needed.
FIG. 11 shows Section A—A of FIG. 10 .
FIG. 12 shows the installation of safety plate 10 of the present invention when used with a roof bolt 22 .
Referring now to FIG. 12 , after epoxy resin 28 has been inserted into a predrilled hole 32 , the bolting machine spins and forces the bolt into the hole, breaking and mixing the container of resin, and pushing the bolt 22 and plate 10 against the mine roof 18 . After a few seconds, the bolt sets and hardens in the epoxy resin 28 inside the roof 18 and then remains tight. The plate's outer rim 6 sits against the roof 18 , compressing strata 34 and tightening them firmly to the roof 18 .
FIG. 13 shows a plate 10 pushing on the roof at 30 to 45 degree angles in all directions around the plate 10 and straight up in the center.
Referring now to FIG. 13 , as the safety plate 10 of the present invention of the present invention is tightened to the roof 18 , the force applied to the center of the plate by the bolt causes the plates outer rim 6 to push up on the roof at a 30 to 45 degree angle. When the bolt 22 is secured, the plate 10 compresses directly above its center, which in turn, compresses the roof 18 in all directions 40 adjacent to the roof bolt 22 .
FIG. 14 shows the safety plate 10 and locations of the apertures for “J” hook 36 .
FIG. 15 shows Section B—B of FIG. 14 with a quarter cut away view.
The roof plate of the present invention is made of a tough, abrasion-resistant material and a large outer diameter, e.g., such as by way of example, 7-12 inches outside diameter, and serves to provide greater square inch coverage in all directions of the installed roof bolt. The constant moving of machinery around the mine and friction against the roof greatly increases the wear and tear on the roof and increases the maintenance interval correspondingly.
In one aspect, the apparatus and method of the present invention preferably provide 36-113 square inches of roof coverage having 7-12 inches outside diameter (7-12″ O.D.). The preferred embodiment includes a center aperture of one inch in diameter.
Sharp corner edges are avoided by not using the square or rectangle shaped plates. In one aspect, the present invention provides a thin rim, and the plate will conform to the roof and always bow upward toward the roof.
The present invention has the center set flush on the roof when the bolting procedure is completed and has a certain amount of the bolt head concealed by the upward indentation. The plate of the present invention is used as a primary roof support in all types of roof.
EXAMPLE
Roof bearing plates in accordance with the present invention were tested by the Mine Safety and Health Administrator. The procedure used by the MSHA to test these plates was to put the plate over a 4 inch hole, and a 1.75 inch ram is pushed in the center of the plate. The plate is preloaded to 6000 foot lbs., and then a measuring device is attached to the plate. The movement or displacement is recorded on a graph. The MSHA test is called the deflection test. After the 6000 foot lbs. force is applied to the plate, the movement can only be 0.120 inches from 6000 to 15000 foot lbs and 0.250 inches from 6000 to 20000 foot lbs. The plates performed as shown in table 1.
TABLE 1
Displacement
Displacement
Strength
Strength
Center
(in.)
(in.)
(lbs.)
(lbs.)
Thickness
Hole Dia.
6 k - 15 k
6 k - 20 k
Load at
Ult. Load
No.
(in.)
(In.)
(.120 max.)
(.250 max.)
.250 in.
(20,000 min.)
1
.132
1″
.022
.062
—
24,100
2
.131
1″
.024
.059
—
24,300
3
.133
1″
.014
.053
—
25,300
4
.133
1″
.032
.070
—
25,400
5
.131
1″
.039
.062
—
29,700
6
.133
1″
.025
.054
—
25,000
7
.133
1″
.022
.063
—
24,000
8
.133
1″
.030
.066
—
25,900
9
.133
1″
.026
.065
—
24,700
10
.133
1″
.030
.064
—
25,200
TABLE 2
Displacement
Displacement
Strength
Strength
Center
(in.)
(in.)
(lbs.)
(lbs.)
Thickness
Hole Dia.
6 k - 15 k
6 k - 20 k
Load at
Ult. Load
No.
(in.)
(In.)
(.120 max.)
(.250 max.)
.250 in.
(20,000 min.)
1
.130
1″
.066
.117
—
24,000
2
.130
1″
.055
.104
—
24,000
3
.130
1″
.052
.100
27,400
27,400
4
.130
1″
.065
.113
27,000
27,000
5
.130
1″
.061
.110
27,400
27,400
6
.130
1″
.063
.113
27,500
27,500
7
.130
1″
.065
.115
27,600
27,600
8
.130
1″
.078
.127
27,700
27,700
9
.130
1″
—
—
—
27,200
10
.130
1″
.055
.198
26,700
26,700
The present invention is used in underground mines to support the roof, during and after the mineral (coal) is extracted.
The apparatus of the present invention is a one piece plate that applies pressure to the roof surrounding a roof bolt as it is installed.
A roof bolt plate, when a roof bolt is installed, provides a larger area to suspend the roof, rather than just the head of the bolt, to prevent the immediate roof from crumbling and becoming unstable. The plate also compresses any cracks in the strata around the bolt and prevents air from entering the cracks and deteriorating the roof. The method of the present invention compresses the area by having the outer rim contact the roof first, and as the bolt is tightened, the plate applies pressure to the roof at a certain (30-45 degree) angle before the center contacts the roof. The roof bolt plate and method of the present invention spread the support out and up from the base of the bolt giving a broader support to the mine roof.
Weathering effect when the roof area around the base of a roof bolt and plate deteriorates and falls to the mine floor leaves a space between the plate and the remaining roof. The weathered area then is considered to be unsupported and unsafe. The method of the present invention cups the area and prevents the weathering condition by confining the immediate roof into a cone shape.
The apparatus and method of the present invention require no filler. The apparatus and method of the present invention operate to have the plate compress the roof and surrounding area by plate to roof contact in as many points as possible. In the apparatus and method of the present invention, the plate bends to conform to the roof and hold pressure between the roof and the plate. By having the plate bend, the plate apparatus and method of the present invention then acts as a lock washer for the bolt and will not allow the plate to loosen. As the plate of the present invention is tightened, the outer rim will not bend away from the roof.
In one aspect, the apparatus and method of the present invention provide increased safety because the safety plate's recessed center conceals the roof bolt head when installed and edges that press against the roof
In one aspect, the apparatus and method of the present invention provide improved safety of personnel by preventing or greatly reducing the number of injuries caused by contact with sharp edges and corners.
In one aspect, the apparatus and method of the present invention provide a substantial reduction in or elimination of the “weathering-effect” by compressing the roof more effectively
The novel mining apparatus and method of the present invention provide increased safety, greater coverage and support of the mine roof, longer lasting components, fewer injuries, and more successful inspections as a result.
I have found that the safety plate of the present invention adheres tightly to the roof. Because of a lock washer effect, the safety plate of the present invention remains tight even when the inspector attempts to loosen it during testing. Many conventional plates become loose and can be rotated, even immediately after installation. Such plates offer inadequate adhesion and require immediate repair or replacement. By contrast, when the safety plate of the present invention is installed, i.e., the roof bolt is pushed to the roof, the plate adheres tightly to the roof.
The novel mining apparatus of the present invention provide a preferred advantage over conventional apparatus. Workers who have toiled in the dark, confined spaces and constraints, often times working in muck and mire, appreciate the feature of increased ceiling height and elimination of dangerous corners and edges with the safety plate, and these features reduce the number and severity of injuries.
The novel mining apparatus and method of the present invention not only provide a more secure, safer work environment through greater support and fewer injuries, but also reduce the need for repair and replacement of roof bolts, and further also supply a positive means of roof control easily monitored by installers, inspectors, and mine examiners.
The roof bolt and plate combination of the present invention provide enhanced safety for a mining system for low coal seams, e.g., such as less than about 48 inches in vertical height. The low coal seams make it extremely difficult for physical activity in the confining spaces and constraints of the underground mine. Every physical effort is magnified many fold in difficulty level by the confining spaces of the low coal.
In one embodiment, the roof bolt and plate provide an effective, low cost means of increasing worker safety and conforming to regulations while extending the life of the roof support system of the mine.
The novel mining apparatus and method of the present invention are capable of providing not only a recessed area, which conceals most of the roof bolt head, but also an outer rim contact area that compresses the roof as the bolt is tightened.
In one aspect, the present invention includes an efficient method to hang cables and wires, thereby to protect power cables from damage by not being run over by equipment.
I have found that the apparatus and method of the present invention permit use in a wide variety of roof conditions, including roofs that are loose or broken regardless of the condition of the roof. The safety plate of the present invention compresses the area, preventing air from entering and deteriorating the roof.
I have found empirically that the combination insert of the present invention allows for use in a low height mine where space is limited.
I also have found that the combination insert of the present invention allows for use in all types of roof conditions, even extremely broken roof strata.
The novel apparatus and method of the present invention accordingly are significantly preferred over conventional apparatus and methods which typically result in significantly less maintenance and repair of areas of the mine that have been weathered and deteriorated over time.
The apparatus and method of the present invention are not intended to be limited to the descriptions of specific embodiments herein above, but rather the apparatus and method of the present invention should be viewed in terms of the claims which follow and equivalents thereof. | Roof bolt bearing plate and method are disclosed for use in underground mining operations. A dome-shaped roof bolt bearing plate and method support the roof in a mine. The bearing plate is round or elliptical different from conventional commercial roof support devices. No dangerous edges and corners protrude downward. A recessed center is lower than the outer rim. A thin outer rim conforms to roof irregularities. The roof bolt bearing plate and method have been found to provide important advantages over conventional commercial roof support devices, including (1) concealing the head of the roof bolt to a preferred degree, (2) conforming to the roof's irregularities which will cause causing the plate to remain tight, (3) provide readability so the installer can to determine the quality and integrity of installation and anchorage, and (4) compressing the lower strata of the mine roof, thereby and creating a beam like support for the upper layers of the mine roof. | 4 |
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a friction brake shoe assembly and method of producing same, and more particularly, to a brake shoe assembly usable for motor vehicles which includes a perforated metal backing plate having raised tabs onto which friction material is cast.
Drum type friction brakes include brake shoe assemblies which are typically urged into contact with an inner cylindrical surface of a rotating brake drum by a hydraulic actuating cylinder. Various approaches to attaching the friction material, typically asbestos based, to the metal shoe or to a separate backing plate have been previously employed or proposed. Generally speaking, two major types of fastening system are currently employed. In one type of system, a pre-formed segment of friction material is bonded by adhesives to the metal brake shoe or to a backing plate which becomes attached to the brake shoe by mechanical fasteners. Another major type employs mechanical fasteners such as deformable rivets which are placed at a plurality of locations on the surface of the friction material and engage bores in the associated brake shoe or backing plate, thereby fastening these parts together. Irrespective of which of the above systems are selected for manufacturing a brake shoe assembly, it is necessary to separately form a segment of friction material and thereafter attach it to a supporting structure.
In view of the above, it is a principal aspect of this invention to provide a brake shoe assembly which may be produced at lower cost as compared to currently available brake shoe assemblies. It is another aspect of this invention to provide a brake shoe assembly featuring excellent mechanical engagement between the friction material and the brake shoe.
The above principal aspects of this invention are provided by an assembly constructed by a process involving casting friction material directly onto a metal brake shoe or to a backing plate which includes a plurality of perforations and raised tabs which cause an interlocking engagement to occur between the friction material and the supporting structure. In accordance with the teachings of this invention, the perforations and raised tabs are formed by cutting a portion of the brake shoe or backing plate and bending a tab portion formed within the area of the cut.
Casted brake shoe assemblies have been previously proposed and a list of such references teaching such techniques are listed below.
______________________________________U.S. PAT. NO. INVENTOR DATE______________________________________1,880,750 T. F. Brackett October 4, 19321,937,140 W. A. Blume November 28, 19331,927,252 W. H. Winters September 19, 19332,650,022 J. C. McCune October 20, 19531,872,850 M. N. Trainer August 23, 19322,948,361 R. B. Pogue August 9, 1960______________________________________
These references, however, do not teach the novel aspects of the brake shoe assembly and method according to this invention.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates upon a reading of the described preferred embodiments of this invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial exploded view of a brake shoe assembly illustrating a first embodiment of this invention;
FIG. 2 is a pictorial view of the backing plate according to the first embodiment of this invention;
FIG. 3 is a cross-sectional view taken along FIG. 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view illustrating the engagement between the cast-on friction material within the perforations and deflected tabs formed by the backing plate;
FIG. 5 illustrates a second embodiment according to this invention wherein each of the deflected tabs are oriented in the same direction;
FIG. 6 illustrates a third embodiment of this invention illustrating a substantially square-shaped deflected tab;
FIG. 7 illustrates a fourth embodiment according to this invention wherein the projecting tab includes a rounded end configuration; and
FIG. 8 illustrates a fifth embodiment wherein the angle between the backing plate and tab is approximately 45 degrees.
DETAILED DESCRIPTION OF THE INVENTION
A brake shoe assembly in accordance with the teachings of this invention is shown by FIG. 1 and is generally designed by reference character 10. Brake lining 17 is composed of backing plate 16 to which a layer of friction material 20 is cast. Brake shoe assembly 10, which is typically actuated into contact with a rotating brake drum by a hydraulic cylinder actuator, is constructed by attaching brake shoe 12 to brake lining 17 by threaded fastener 14. Backing plate 16 includes a plurality of protruding threaded bosses 18 which engage fasteners 14. As is evident from FIG. 4, friction material 20 is cast onto backing plate 16 such that material flows within perforations 22 formed therein. Preferably, a sufficient quantity of friction material 20 is applied under pressure within a forming mold such that the material is caused to flow into perforations 22, and upon solidification, tightly engages backing plate 16. Perforations 22 are formed by cutting backing plate in a manner that a curved cut is formed. The ends of the cut are not joined such that no material becomes separated from the backing plate. Projecting tabs 24 are formed by bending the material within the cut in a radially outward direction with respect to the center of rotation of the associated wheel.
Perforations 22 and tabs 24 may be oriented in various patterns. For example, with reference to FIG. 2, three distinct circumferential lines 26, 28 and 30 are formed by tabs 24. The outermost perforations 22 and tabs 24 are oriented such that they are directed in a direction toward a center circumferential line. The orientation of tabs 24 with respect to brake shoe 12 influences the integrity of the bond between the friction material 20 and backing plate 16. Tabs 24 along central circumferential line 28 are oriented such that they extend in a direction transverse to the circumferential direction of line 28, thereby strongly resisting movement of friction material 20 relative to backing plate 16 due to external loads exerted in the direction of that line. Likewise, tabs 24 along lines 26 and 30 strongly resist displacement of friction material 20 in a direction transverse to the circumferential lines. Another orientation for tabs 24 is illustrated by FIG. 5 wherein, as described in connection with the first embodiment, tabs are directed along three circumferential lines, 26, 28 and 30. However, the second embodiment illustrates each of the tabs being directed in the same direction. Such configuration would provide enhanced strength when the friction material 20 is loaded primarily in a circumferential direction. Since forces exerted on friction material 20 are normally exerted in a circumferential direction by a rotating brake drum, the embodiment illustrated by FIG. 5 would likely be preferred for most applications.
Tabs 24 are formed by cutting backing plate 16 along three sides of a square or rectangle and bending along the fourth side. Other shapes for the tabs formed within brake lining base 16 are also possible. A third embodiment of this invention is shown by FIG. 6 in which tabs 124 have a substantially square or rectangular shape. Such configuration for tabs 124 provide a somewhat greater area of engagement between friction material 20 and backing plate 16. An additional embodiment is shown by FIG. 7 wherein tab 224 are provided having a rounded terminal end. Such configuration has advantages over the first embodiments in that the perforation formed has fewer sharp corners from which fatigue fractures could emanate. Tabs 224 are formed by cutting backing plate 16 along a pair of parallel lines connected at one end by a curved line, and bending along a line connecting the two parallel lines. The embodiments depicted by FIGS. 6 and 7 are subject to the same selective orientation as was explained with regard to the first two embodiments.
A fifth embodiment of this invention is shown by FIG. 8, and varies from the above-described embodiments in that the angle formed by tab 24 with respect to backing plate 16 is approximately 45 degrees as compared to 90 degrees of the previous embodiments. This angle is identified as angle "A" in FIG. 8. By decreasing angle A, the service life of the brake shoe assembly can be increased, since the tabs protrude a smaller distance in a radial direction into friction material 20, as compared to the first through fourth embodiments. Angle "A" must, however, be sufficiently great to permit free flow of friction material 20 into perforation 22 during the casting process.
While the perimeter shape of tabs 24, 124 and 224 differ, they are each substantially planer in shape and each are formed by bending along a straight line. Such configuration features simplify the tooling and cost thereof as compared to designs requiring complex forming operations.
During production, tabs 24 are formed first by cutting backing plate 16. The stock within the cut portion is next deflected along a straight break line to form protruding tabs 24. Alternatively, the process of cutting and bending tabs 24 could be performed in one step using a single tool. Upon completion of processing of backing plate 16, the plate is loaded into a casting apparatus wherein a layer of friction material 20 is deposited in a fluid or semi-fluid state and thereafter cures to a solid state. As a final manufacturing step, the completed assembly would likely be arced or ground such that the outer cylindrical surface is properly shaped.
While the above description specifies an assembly and method involving a brake shoe assembly 10 employing a separate backing plate 16, processes and assemblies wherein perforations 22 and tabs 24 are formed within brake shoe 12 are equally within the scope of this invention.
While the above description constitutes the preferred embodiments of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims. | An improved brake shoe assembly is provided wherein friction material is cast directly onto a brake liner plate. The brake liner includes a plurality of perforations which form protruding tabs. Interengagement between the cast friction material and the perforated areas and tabs provides excellent interlocking strength between these components. The number, size, orientation and configuration of these tabs may be selected with regard to the specific operating characteristics to which the brake shoe assembly is to be employed. | 5 |
BRIEF DESCRIPTION OF THE INVENTION
The invention relates to a sewing machine, and more particularly relates to a needle position control system of an electronic sewing machine, in which a needle position may be displaced, depending on the stitching type, to the most suitable position in the lateral swinging range of the needle relative to the fabric to be sewn, instead of locating the fabric in reference to the needle.
In sewing up with the straight stitches the edge of fabric which is folded up two or three times, it is conventionally general to displace the needle position to the center of the lateral swinging range of the needle and locate the edge of the fabric under the needle. As a result, the thicker edge of the fabric is placed only on a part of the feed dog and placed under only a part of the presser foot, and the fabric is not suitably transported and also the presser foot is unstable, and therefore a desired stitching operation cannot be attained. Further in case the edge of the fabric is accompanied by the fabric folding operation during stitching, the fabric cannot be suitably displaced relative to the needle and the feed dog. Further in case there are obstacles or steps in the fabric in the sewing direction and additionally the fabric cannot be displaced relative to the needle and the feed dog, a desired stitching operation cannot be attained.
The invention has been provided to eliminate the defects and disadvantages of the prior art. It is a primary object of the invention to provide a sewing machine which is able to displace the needle position in the straight stitching relative to the fabric to be sewn, thereby to elevate the operation efficiency of the sewing machine especially with respect to the edge stitching of the fabric.
It is another object of the invention to provide a sewing machine which is simple in structure and easy in operation for attaining the above mentioned object.
The features and advantages of the invention will be apparent from the following description of the preferred embodiment in reference to the attached drawings.
SUMMARY OF THE INVENTION
The present invention provides a sewing machine to produce stitches, which is electronically controlled to change the relative position between needle and fabric to be sewn. The sewing machine comprises a first memory (ROM1) storing pattern data including the data for producing straight stitches, a pattern selecting means selectively operated to select a set of pattern data of such data stored in the first memory, a second memory (ROM2) storing automatic setting information each specific to the selected patterns and controlling commonly the stitches of the selected pattern, operator controlled means (VR1,VR2) for adjusting the control of the automatic setting information with respect to the stitches of the selected pattern, and calculating means (AU1,AU2) receiving the output of at least one of the second memory (ROM2) and the operator controlled means (VR1,VR2) to calculate the stitches of the selected pattern.
The pattern selective means can comprise pattern selecting switches. One of the pattern selecting switches can be a straight stitch selecting switch. The pattern selecting means can comprise NAND circuits (NA 1 to NA 3 ) connected to the pattern selecting switches and a latch can be connected to the NAND circuits and to the second memory.
The pattern selecting means can further comprise a NAND-circuit for detecting pattern selection and connected to the pattern selecting switch and a monostable multivibrator (MM1) connected to and triggered by the NAND circuit for detecting pattern selection and connected to the latch.
The sewing machine can further comprise an automatic-manual switch for needle swing amplitude ratio reduction and a flip-flop circuit (FF1) connected to the monostable multivibrator (MM1), to the calculating means and to the automatic-manual switch (S8). There can also be provided an automatic-manual switch concerning fabric feed control and a second flip-flop circuit (FF2) connected to monostable multivibrator (MM1), to calculating means and to the automatic-manual switch concerning fabric feed control. There can also be provided an AND-OR circuit connected to the monostable multivibrator (MM1) and a time delay circuit (TD) connected to the monostable multivibrator (MM1) and to the first memory.
The sewing machine can further comprise NAND-gate (NA 5 ) connected to time delay circuit and a second latch connected to the NAND-gate (NA 5 ) and to the first memory. A NAND-gate (NA 6 ) can be connected to the time delay circuit and a NAND-gate (NA 7 ) can be connected to NAND-gate NA 6 and to the second latch. The sewing machine can also comprise a pulse generator (TPG) and a second monostable multivibrator (MM2) connected to the pulse generator and connected to the NAND-gate (NA 7 ). The first memory preferably produces fabric feed control signals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B shows a control circuit of an electronic control sewing machine according to the invention, and
FIG. 2 shows a code table.
DETAILED DESCRIPTION OF THE INVENTION
The invention will be explained in reference to the attached drawings. In reference to FIGS. 1A and 1B, PC is a circuit for selecting the patterns to be stitched and generating the signals controlling the stitches of selected patterns, and is substantially the same with that of the Japanese Patent Application No. 50-124,306 of the same applicant. S0 to S7 are pattern selecting switches generally arranged on the front part of the sewing machine. S0 is a straight stitch selecting switch. ROM1 is an electronic memory storing the stitch control data of the patterns to be stitched, and has the input terminals A1-A8 for receiving the address signals which are produced at the address changing output terminals 01-06 for addressing said memory itself per each of the stitches. The memory has the output terminals 07-011 of fabric feed control signals which are called as (GF) hereinafter. Those feed control signals (GF), when they include no reducing ratio of the needle swinging movement, designate the fabric feeding amount of 2.5 mm in the reverse direction by the digital number 0 and the fabric feeding amount of 2.5 mm in the normal forward direction by the digital number 30, thus dividing the fabric feeding range into 30 positions. The memory also has the output terminals (012-016) of needle swing control signals which are called as (GB) hereinafter to designate the needle position at a point in the maximum leftward direction by the decimal number 0 and at a point in the maximum rightward direction by the decimal number 30, thus dividing the needle swinging range into 30 positions. The straight stitch selecting switch S0 is provided with the data 30 in relation to the basic needle position changing data in a manner which will be described hereinafter.
L1 and L2 are latch circuits. The latch circuit L1 receives the pattern selecting signals of the switches S0-S7 via NAND circuits NA1, NA2, NA3 encoding the pattern selecting signals. If one of the switches is operated, the monostable multivibrator MM1 receives at the trigger terminal Cp a rising signal of NAND circuit NAND4 detecting the pattern selection. Thus the monostable multivibrator MM1 is operated. Then the latch circuit L1 receives at the trigger terminal Cp the signal of the monostable multivibrator MM1 and latches the encoding pattern selecting signals so that the memory ROM1 may perform the addressing operation based on the selected pattern. AND-OR circuit AND-OR, which is operatively connected to the monostable multivibrator MM1 and the time delay circuit TD, gives at the time of pattern selection 1 bit as an addressing signal to the input terminal A6 of the memory ROM1. The 1 bit is so selected that the AND-OR circuit produces another 1 bit of the outputs of the latch circuit L2 as the subsequent address signals.
The latch circuit L2 is at first reset by the pattern selecting signal passing through NAND circuit NA5, and is released from the reset condition by activation of the monostable multivibrator MM1. The latch circuit L2 receives at the trigger terminal Cp a signal passing through NAND circuits NA6, NA7 and rising at the delaying circuit TD, and latches the signals of the address changing terminals O1-O6 directed to the address input terminals A1-A6 of A1-A8 of the memory ROM1 for making the first stitch. Then each time when the latch circuit L2 receives at its trigger terminal Cp the rising signal, through the monostable multivibrator MM2, of the pulse generator TPG operated in synchronism with rotation of the upper shaft of the sewing machine, the latch circuit L2 latches the signals of the address changing terminals O1-O6 to the address input terminals A1-A6 for the subsequent stitches.
R1 is an ordinary limit resistor connected to a DC control power source (+V) and giving a reference control voltage to each of the switches S0-S7.
The output from the pulse generator or position detector TPG is at H level (H) in a region where the needle is located above the fabric, while it is at L level (L) in a region where the needle penetrates into the fabric, and the output terminal thereof is connected to the trigger terminal Cp of the monostable multivibrator MM2. ROM2 is an electronic auxiliary memory storing automatic setting data specific to individual stitch patterns stored in the ROM1. The ROM2 receives, as the address signals, at the input terminals B1, B2, B3 thereof, the pattern selecting signals from the latch circuit L1, and releases from the stored contents in response to said address signals, two groups of 5 bits setting data. The stored contents are as shown in FIG. 2 in which (B) shows, in the decimal system, the address codes which are designated by the address terminals B1, B2, B3 in response to the pattern selection. The numerals 0 to 7 correspond to the pattern selecting switches S0-S7. (AF) are the data to be used for calculation to automatically set the fabric feeding conditions in relation with the selected patterns, and the setting data are issued from the output terminals P1-P5. Similarly, (AB) are data to be used for calculation for automatically setting the needle lateral swinging amplitude, and are issued from the output terminals P6-P10. (N) is a needle dropping hole changing device which enlarges the needle dropping hole in a laterally elongated hole when the patterns of stitches made by the needle lateral swinging movements are selected by the pattern selecting switches S1-S7, and which reduces the laterally elongated hole into a circle hole when the straight stitching is selected by the switch S0. In addition to the straight stitching selection, if some operation, which will be described hereinafter, is made to change the needle position for the straight stitches, the device N is operated to change the needle dropping hole into the laterally elongated one. Such a needle dropping hole changing control device which is provided with an electromagnetic drive control element, is disclosed in the Japanese Patent Application No. 53-7680 of the same applicant. When the straight stitching is selected by the pattern selecting switch S0, NOR circuit NOR receives the code 0 0 0 issued from the latch circuit L1 and produces the signals of H level which is applied to one input of AND circuit AND. This input causes the AND circuit to provide a high level signal at the input of the needle dropping hole changing device N in the condition that the operation is not carried out to change the needle position for straight stitches. Thus, the needle dropping hole changing device N is caused to provide the reduced circular needle dropping hole. Otherwise the needle dropping hole changing device N is operated by the L level signal to provide the laterally elongated needle dropping hole. S8 is an automatic-manual operating switch for controlling the lateral swinging movement of the needle. If the switch S8 is operated after one of the switches S0-S7 has been operated, the switch S8 changes the automatic set of needle swing amplitude ratio reduction in accordance with the selected pattern to the manual set of such a ratio reduction including the change of the needle position for the straight stitching. The automatic set is recovered by another operation of the switch S8. FF1 is a D-type flip-flop circuit which is set when it receives at the preset terminal PS a falling signal of a complement output terminal (Q) of the monostable multivibrator MM1. The flip-flop circuit FF1 has a true side output terminal (Q) connected to the other input of AND circuit AND, and makes effective the input of AND circuit AND after selection has been made by the switches S0- S7. The flip-flop circuit FF1 has a data input terminal D connected to the complement output (Q) thereof so that the flip-flop FF1 may invert the previous condition of the outputs Q, Q when FF1 receives the pulse signal at the trigger terminal Cp thereof by operation of the switch S8. When the output (Q) is at L level, FF1 makes L level the input of the needle dropping hole changing control device (N) to designate the needle dropping hole to be laterally elongated. (R2) is a pull-up resistor. (IN1) is an inverter. (VR1) is a variable resistor for manually controlling the reducing ratio of the needle lateral amplitude including the change of needle position for the straight stitching and an operating part of the variable resistor VR1 is disposed at, e.g., the front part of the sewing machine, and the controlled result is converted into a digital value by an analog-digital converter (A/D1) which has a number of data bits each connected to the input of a group of AND-OR circuits (AND-OR) (in the drawing one of them is shown and the others are omitted). Each of AND-OR circuits receives the complement output signal (Q) of the flip-flop FF1 directly and also in the inverted condition as shown. If the signal is H level, the AND circuit directly receiving the signal receives the data of the converter (A/D1). On the other hand, the AND circuit receiving the inverted signal receives one bit composing the output (AB) of the ROM2. If the inverted signal (Q) of the flip-flop FF1 is L level, the AND circuit receives the signal of ROM2. The output of the AND-OR circuit (AND-OR1) is connected to the input K1 of the first arithmetic unit AU1, which also has the input receiving the needle swing control data (GB) of ROM1, and has also another input K2 of 4 bits receiving the output of the NOR circuit NOR through the inverter IN2, the output being common to the 4 bits forming the needle position changing code. The arithmetic unit AU1 carries out a calculation according to a formula of K'1(G'B-K'2)/30+K'2 wherein the primed value is converted in the decimal number, and gives the encoded data to a needle swing control device (BD). (S9) is an automatic-manual switch concerning the fabric feed control. When the switch (S9) is operated after selection of the switches S0-S7 has been made, it changes the automatic set of fabric feed ratio reduction in accordance with the selected pattern to the manual set of such a ratio reduction. The automatic set is recovered by another operation of the switch (S9). (FF2) is a D-type flip-flop circuit which has the same function with the flip-flop circuit (FF1) but does not have a true side output terminal. (R3) is a pull-up resistor, and (IN3) is an inverter. (VR2) is a variable resistor for manual control of the fabric feed ratio reduction. (A/D2) is an analog-digital converter thereof. (AND/OR2) is a group of AND-OR circuits, the output of which is connected to the input data terminals (K3) of the second arithmetic unit (U2). The arithmetic unit (AU2) carries out the calculation by the formula of K'3(G'F-15)/30+15 similarly as in the arithmetic unit (AU1), and encodes the calculated result to give it to the fabric feed driving device (FD).
In the above mentioned structure, if the straight stitching is selected by the pattern selecting switch (S0), the data G'B of the needle lateral swinging amplitude control signal GB becomes 30. The code of the latch circuit (L1) becomes 0 0 0 to put the output of NOR circuit (NOR) at H level, and therefore the needle position changing code K2 of the first arithmetic unit (AU1) becomes 0 0 0 0 as shown in FIG. 2, and K'2 becomes 0. The flip-flop circuit (FF1) is set via NAND circuit (NA4) and the monostable multivibrator (MM1), and the complement output (Q) is made at L level and causes the group (AND-OR1) of AND-OR circuits to make the input AB operative, and K1 becomes 0 1 1 1 1 and K'1 becomes 15. The arithmetic unit (AU1) becomes 15(30-0)/30+0=15 by the formula of K'1(G'B-K'2)/30+K'2, and designates the center part of the needle swinging range, and the needle swing driving device (BD) positions the needle at the center position. Concurrently, the AND circuit (AND) becomes H level and the needle dropping hole changing device (N) is operated to provide a reduced circular needle dropping hole. The change of the needle dropping hole is made when the displacement of the needle has been separately detected.
Then if the automatic-manual changing switch (S8) for the needle lateral swinging control is once pushed, the flip-flop FF1 is reset, and the needle dropping hole changing device (N) provides the laterally elongated needle dropping hole. The group of AND-OR circuits (AND-OR1) makes operative the digitalized value of the manually controlled value by operation of the variable resistor (VR1) to provide the input K1 of the arithmetic unit (AU1). When the resistance of variable resistor (VR1) is set at the minimum value, the decimal number K'1 is 0 and "0(30-0)/30+0=0" is provided by the formula of K'1(G'B-K'2)/30+K'2, and the needle position is designated at a point maximum in the leftward direction. Similarly, when the resistance is set at the maximum value, the decimal number K'1 is 30, and "30(30-0)/30+0+30" is provided, and the needle position is designated at a point maximum in the rightward direction. Thus the needle is displaced laterally at a desired position in the swinging range.
When the pattern including the needle swinging movement is selected by operation of any one of the pattern selecting switches (S1-S7), the latch circuit (L1) includes H level in its output code, and therefore, the output of AND circuit (AND) becomes L level, irrespective of the condition of the flip-flop FF1. As a result the needle dropping hole changing device (N) provides a laterally elongated needle dropping hole. The switch (S1) is for selecting the zigzag stitching, and, for example, if it is operated, the data AB of the memory (ROM2) is 1 0 1 1 0 according to the Table in FIG. 2, and the decimal number K'1 becomes 22. The memory (ROM2) gives, at its output GB, 0 0 0 0 0 and 1 1 1 1 0 alternately for the zigzag stitches. Namely, the memory produces 0 and 30 alternately as the decimal number G'B, and the needle position changing code K2 becomes 1 1 1 1 in reference to the Table in FIG. 2, and the decimal number K'2 becomes 15. The arithmetic unit (AU1), therefore, issues 22(0-15)/30+15=4 and 22(30-15)/30+15=26, alternately in accordance with the predetermined formule. Thus, the needle swing control device (BD) produces the zigzag stitches which are each reduced at the right and the left ends more than the maximum zigzag stitches in the needle swinging range. The operation including the calculation of the fabric feed is substantially the same as the above mentioned operation. | An electronically controlled sewing machine to produce stitches and to change the relative position between the needle and the fabric to be sewn. The sewing machine comprises a first memory (ROM1) storing pattern data including the data for producing straight stitches, pattern selecting means selectively operated to select a set of pattern data of such data stored in the first memory and a second memory (ROM2) storing automatic setting information each specific to the selected pattern and controlling commonly the stitches of the selected pattern. An operator control means adjusts the control of the automatic setting information with respect to the stitches of the selected pattern and a calculating means receives the output of at least one of the second memory (ROM2) and the operator controlled means (VR1, VR2) to calculate the stitch coordinate to each of the stitches of the selected pattern. | 3 |
REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Patent Application No. 60/055,154, filed Aug. 8, 1997.
NOTICE OF GOVERNMENT RIGHTS
This invention was made with Government support under a contract awarded by DARPA. The Government has certain rights in this invention.
TECHNICAL FIELD
The present invention relates to method of growing large, single crystal, superconducting YBa 2 Cu 3 O 7-x crystals (123 YBCO) and to the crystals so produced. More particularly, the invention relates to sintering fine powders of YBa 2 Cu 3 O 7-x precursors, where x≦0.6, for controlled times at suitable temperatures in a thermal gradient controlled independently for the radial crystal growth and axial crystal growth to produce superconducting 123 YBCO single crystals several centimeters in diameter (typically 2-8 cm; about 1-3 inches).
BACKGROUND OF THE INVENTION
Superconductors based on the YBa 2 Cu 3 O 7-x system [123 YBCO], where x≦0.6, have been known since IBM researchers discovered them in 1986. They are called "high temperature" superconductors because they are superconducting at temperatures well above absolute zero, e.g., at liquid nitrogen temperature (77° K) and higher.
YBa 2 Cu 3 O 7-x crystals can trap magnetic fields, but the flux density is largely dependent on the grain size and the microstructure. The largest trapped magnetic fields require large grain, single crystal specimens, but growing YBa 2 Cu 3 O 7-x crystals larger than 0.5 cm in diameter is difficult. It is especially difficult to make crystals that can achieve a current density (J c ) exceeding 10 3 A/cm 2 in a magnetic field of 1 Tesla or higher at 77° K. Conventionally made YBa 2 Cu 3 O 7-x superconductors tend to exhibit rapid loss of J c when subjected to magnetic fields of increasing strength.
Several researchers have attempted to increase crystal and grain sizes and improve J c by a quench-melt-grow method (Mat'l Res., Vol. 7, No. 4, April 1992, pp. 801-807) or by directional solidification (Cryogenics, Vol. 30, January 1990, pp. 5-10). These prior art methods have not achieved a crystal with sufficient magnetic flux trapping ability and current density capacity for practical application in such devices as low loss magnetic bearings, high strength magnetic clamps, or high gain electromagnetic antennas.
SUMMARY OF THE INVENTION
A large, single crystal 123 YBCO material that is practical for these applications can be made using the method of the present invention. This crystal iis superconducting at temperatures at or below about 77° K is made by mixing powders comprising from about 1 to 25 weight percent (1-25 wt %) Y 2 BaCuO 5 , [211 YBCO] from about 0.05-1.0 wt % platinum, and the balance YBa 2 Cu 3 O 7-x , [123 YBCO] where x≦0.6. The powders have an average particle size of about 5 micrometers or less, and are preferably pressed into a compact having a substantially right circular cylindrical shape.
We place a seed crystal of SmBa 2 Cu 3 O 7-y , [123 SBCO] where y=1.6, in a base plane slab or slice at the center of the top or bottom circular surface of the compact. The seed crystal is oriented so that the desired seed crystal plane is substantially parallel to the compact's top or bottom surface. The compact and seed crystal are placed on a setter which prevents leaching of the liquid phase during sintering. The compact is then heated to a sintering temperature between about 1010-1050° C. and held at that temperature for a time sufficient to fuse the seed crystal to the compact surface, generally at least about 0.1 hour. Then the temperature is lowered at a rate of from about 1-10° C. per hour. YBa 2 Cu 3 O 7-x [123 YBCO] crystal growth nucleates from the SmBa 2 Cu 3 O 7-x [123 SBCO] seed crystal as the crystal cools. After nucleation, the compact is cooled at a rate of from about 0.1-1.0° C. per hour to a temperature of about 950° C. 123 YBCO crystal growth radiates from the nucleation site until the entire compact consists essentially of single crystal, single grain YBa 2 Cu 3 O 7-x body. The compact may then be cooled more quickly to room temperature. The sintered compact is annealed at a temperature in the range from about 400-600° C. in an oxygen atmosphere for at least about 10 hours.
The present invention, therefore, relates to a method for making a large, single crystal 123 YBCO superconductor using a samarium oxide seed crystal to promote growth in a compact of 123 YBCO precursor powders and an effective amount of Pt.
A preferred feature of the present invention also relates to a method for making a large, single crystal 123 YBCO superconductor by, first, creating independent temperature gradients radially and axially in a compact of 123 YBCO precursor powder, 211 YBCO precursor powder, and an effective amount of Pt. The gradients are each generally about 1-20° C./inch of compact. Cooling the compact further while maintaining the temperature gradient at a rate of cooling sufficient to nucleate single crystal growth in the compact produce the desired large crystal.
We control the microstructure in these single crystals to achieve substantially uniform, large critical current densities that provide excellent superconducting performance in large magnetic fields. We have made crystals up to 3 inches in diameter and crystals with critical current densities over 10 4 A/cm 2 in magnetic fields of 2-8 Tesla or more at 77° K.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a furnace suitable for processing superconducting YBa 2 Cu 3 O 7-x bodies in accordance with the invention.
FIG. 2 is a perspective view of a powder compact and a seed crystal on the surface of a compact of 123 YBCO precursor powders prior to sintering showing grain growth directions from the seed crystal.
FIG. 3 is another perspective view, similar to FIG. 2, showing a seed crystal embedded into the center of the compact.
FIG. 4 is a graph that illustrates the current densities at different magnetic field strengths we have achieved with two inch diameter single crystal 123 YBCO materials of the present invention.
FIG. 5 is a graph that illustrates the AC susceptibility as a function of temperature for 123 YBCO single crystals of the present invention.
FIG. 6 is another graph that illustrates the trapped field profile for our two inch diameter 123 YBCO materials at 77° K.
DETAILED DESCRIPTION
In accordance with a preferred embodiment of the present invention, a large, substantially single crystal of superconducting YBa 2 Cu 3 O 7-x , where x≦0.6, [123 YBCO] is made by combining micron size particles comprising from about 1-25 wt % Y 2 BaCuO 5 (211 YBCO) with about 0.05-1.0 wt % platinum (Pt), and the balance YBa 2 Cu 3 O 7-x in an organic solvent, such as hexane or acetone, to form a thin slurry. The 211 YBCO provides flux pinning centers throughout the single crystal while the Pt, we believe, limits the growth of the 211 YBCO particles and limits the loss of liquid from the melt during crystal growth. The slurry mix is attrited in a ball mill for a time sufficient to provide thorough mixing of the several constituents, generally for several hours. The slurry is cooled sufficiently, if necessary, to prevent evaporation of the solvent. After attriting, the powder is sieved from the slurry and passed through an air driven jet mill. The milled powder is either processed immediately or stored in an inert atmosphere until needed. The average particle size is less than 5 micrometers.
To process the powder into a superconducting body, it is pressed into a green compact disk in a standard press at 2,000-10,000 psi, and then further condensed by cold, isostatic compaction at 15,000-45,000 psi or higher. The preferred compact shape is cylindrical to promote single crystal growth, however, other desired shapes may be formed by adapting the sintering cycle described below.
Referring to FIG. 1, the compact 2 is placed on a setter 4 prior to sintering. Seed crystal 6 of a suitable material such as SmBa 2 Cu 3 O 7-x , where x=1.6, is placed generally at the center 8 of top circular surface 10. The seed crystal 6 is oriented so that the desired crystal plane, preferably the A-B plane of a SmBa 2 Cu 3 O 7-x crystal, is in contact with and substantially parallel to the compact's top surface 10. If desired, such a seed crystal may be pressed into the compact during powder consolidation anywhere along a central axis of the compact.
The setter 4 is preferably lined with a layer 12 of a sintered YBa 2 Cu 3 O 7-x gravel which is relatively rich in platinum. The setter 4 is preferably low mass so that it does not cause substantial conductive heating to the compact 2. Layer 12 is adapted to prevent crystallization of the compact 2 and to prevent leaching of liquid phases during sintering.
The setter 4 is supported in the furnace 14 with a ceramic rod 16. The rod may be made of silica or other refractory material which does not interfere with sintering of the compact 2. The rod 16 may be moved up and down in the furnace 16 through asealed outlet 18. A controlled draft of filtered air is provided to the sintering chamber 20 within the furnace 14 through port 22. The floor 24 and walls 26 of the furnace 14 are also made of a suitable refractory material such as mullite. Sets of heating coils 28, 30, and 32 surround the walls 26 and are heated separately and independently to create desired temperature gradients within the sintering chamber 20. Top 34 and top cap 36 of the furnace are preferably made from fused, transparent silica to form an observation window that is resistant to the furnace temperature yet allowing viewing of the compact 2 during heating. Top 34 has a central opening or port 38. The cap 36 can be moved with respect to the port 38 to control gas flow from the sintering chamber 20. An iris shutter 42 in retaining ring 44 is thermally reflective and can be opened and closed to further modulate temperature in the chamber 20.
The following examples describe our preferred methods for making large 123 YBCO single crystals:
EXAMPLE 1
(a) Powder Process
Mix 85 mol % 123 YBCO, 15 mol % 211 YBCO, and 0.5 wt. % platinum Standard process batch size:
1500 g 123 YBCO
185 g 211 YBCO
8.425 g platinum
These powdered materials are mixed in a large excess of hexane in a large beaker using an industrial stirring blade to create a thin slurry. Mixing time is about 1 hour. The resulting slurry is poured into a large capacity attritor (ball mill) while the mill is turning at about 120 rpm. The grinding media in the mill generally is silicon nitride coated with Y, Ba, Cu oxide. The materials are ground/mixed (i.e., "attrited" for 6 hours, and the resulting slurry is poured into trays to remove the hexane. The silicon nitride grinding media is removed, and the dry powder is sieved through a 75 micron sieve. The powder is then weighed and placed in appropriate containers for later use.
(b) Pressing Process
The materials are weighed and poured into the proper size die, and pressed to between 4750 and 5250 psi for a 1.2" or 1.4" diameter die, to about 3000 psi for a 2.1" die, and to about 2250 psi on a 3" or 3.5" die. The pressed pellets are pushed out of the die and are placed in a rubber isostatic pressing bag and sealed. A vacuum is then "pulled" on the inside of the bag. The bag is placed in the isostatic press, and pressed with about 20,000-25,000 psi. The sample is removed from the bag just prior to being placed in the sintering furnace.
(c) Growing Procedure
black max #2
powder preparation and pressing as previously explained.
[Boeing ID# B95037]
1.4"×0.8" to start
Set up the furnace from bottom to top as follows:
1) 1 large alumina disc; sample support--0.5"×0.2"
2) 4 (2 stacks of 2 each) alumina spacers-offset from center 2" (that is, 2"×0.6"×0.06" (0.12" combined))
3) 1 very thin, permanent alumina plate--0.4"×0.028"
4) 1 very thin, consumable alumina plate--0.4"×0.028"
5) 1 thin disc of magnesium oxide--2.25"×0.2"
6) 1 premelted disc of 123 YBCO--1.8"×0.3"
7) 3 formed cubes of pure platinum--placed equidistant from the edge to the center of where the sample is to be placed, 120° apart--0.1"×0.1"×0.1"
8) sample (pellet) to be processed--1.275"×0.75", 70.298 g
9) samarium oxide [123 SBCO] seed crystal--0.5 mm×0.5 mm×0.25 mm atop the pellet in the proper orientation.
The sample and associated equipment are lowered into the furnace 20 to a point where the sample surface is about 22.25" from the top of the processing tube, and is centered radially. A 0.13" quartz disc is placed over the top of the process tube. The furnace temperature was controlled to heat with the following profile:
______________________________________180° C./hr - 1084° C. set hold 0.5 hours10° C./hr - 1071° C. set no hold0.5° C./hr - 1064° C. set no hold0.1° C./hr - 1053° C. set no hold0.5° C./hr - 1025° C. set no hold50° C./hr - 23° C. (ambient) end______________________________________
Our laboratory furnace exhibited a nonlinear radial gradient of 10-12° C. After cooling, we removed excess material from the bottom of the sample.
(d) Test Results
Flux Trap Measurements--after 70 Hours in Oxygen
5000 Gauss applied--3960 Gauss top, 3040 Gauss bottom after 230 hours in oxygen
5000 Gauss applied--4180 Gauss top, 3370 Gauss bottom after 390 hours in oxygen
5000 Gauss applied--4075 Gauss top, 3200 Gauss bottom
10000 Gauss applied--5300 Gauss top, 4300 Gauss bottom
EXAMPLE 2
Growing Procedure
Ceramics Lindberg
Powder preparation and pressing as previously explained.
[Boeing ID# B95052]
1.4"×0.625" to start
Set up the furnace from bottom to top as follows:
1) 1 block of commercial fire brick--2"×2"
2) 1 very thin square of alumina--3"×3"×0.028"
3) 1 thin disc of magnesium oxide.--2.25"×0.2"
4) premelted disc of 123 YBCO--1.8"×0.3"
5) Small amount (enough to cover the area of the pellet to be processed) of pre-melted crushed 123 YBCO--300 to 589 microns
6) Sample (pellet) to be processed--1.275"×0.6", 56.02 g
7) Samarium oxide [123 SBCO] seed crystal atop the sample in the desired orientation--0.5 mm×0.5 mm×0.25 mm
The sample and associated substrates were placed in the center of the furnace horizontally and vertically, and the furnace is then sealed. The furnace temperature was controlled to heat with the following profile:
______________________________________200° C./hr - 1010° C. set hold 0.5 hours10° C./hr - 995° C. set no hold0.3° C./hr - 944° C. set no hold100° C./hr - 23° C. end______________________________________
This particular furnace exhibited a thermal gradient of between 0 and 2° C./inch in the sample area.
After cooling, excess material was removed from the bottom of the sample.
Test Results
______________________________________Flux trap measurements - after 160 hours in oxygen______________________________________ 5000 Gauss applied 4440 Gauss top, 3710 Gauss bottom10000 Gauss applied 6400 Gauss top, 5000 Gauss bottom after 320 hours in oxygen10000 Gauss applied 6600 Gauss top, 5000 Gauss bottom______________________________________
We prefer to use a specific temperature cycle and 3-dimensional thermal gradient during crystal growth. This gradient allows two phases of YBCO (Y 2 BaCuO's or 211 plus a liquid barium cuprate phase, Ba 2 CuO's) to react. This reaction is heterogeneously initiated by a seed crystal of SmBa 2 Cu 3 O 7-y (123 SBCO) where y≦1.6. The crystals are typically grown from the center of a disk outward until the entire disk is one grain. Other geometries, such as a long rectangular bar, are possible. Our method of achieving our specific thermal gradient (and the parameters of this gradient) are what enable us to control the crystal growth conditions. The radial and vertical thermal gradients we use are from 1-20° C. per inch of radius on a circular specimen and from 1-20° C. per inch of thickness. Equivalent gradients are used on rectangular specimens.
We place a SiBa 2 Cu 3 O 7-y (123 SBCO) single seed crystal on or within the compacted YBCO powder disk prior to heating. We make the seeds in our laboratory using a process similar to that for making the 123 YBCO single crystals. A 123 SBCO seed crystal or its equivalent initiates the epitaxial growth of the 123 YBCO crystal at the desired location and in the desired orientation. The process of growing the SBCO seed crystals for proper YBCO crystal nucleation is unique, we believe, to the process of the present invention. The seed crystals must have the purity and lattice dimensions appropriate for the heterogeneous nucleation of 123 YBCO.
A specific ratio and particle size distribution of 123 and 211 YBCO powders with the addition of a specified amount and particle size of platinum powder achieves the desired growth of 123 YBCO single crystals capable of trapping high fields.
Platinum added to the powder precursor improves yield and quality. We have been successful with several methods for processing the platinum. These processing methods include: a method for making colloidal platinum, precipitating platinum hydroxide, or reducing platinum oxide to elemental platinum. The addition of finely divided platinum to the YBCO precursor powders prevents coarsening the grain size of the 211 YBCO during the crystal growth process.
We generally use the following 17 sequential steps to fabricate large YBCO superconducting single crystals successfully:
(1) Comminute the 123 YBCO and 211 YBCO powders so that all particles are less than 37 micrometers in size, and comminute platinum so that all particles are between 0.25 and 2 micrometers in size.
(2) The individual powders are dispersed with a nonaqueous, liquid solvent, such as hexane or acetone, to form thin slurries.
(3) The three slurries are mixed. The resulting slurry has 123 YBCO powder, about 0-25 wt % dispersed 211 YBCO powder, and about 0-1 wt % dispersed platinum powder.
(4) The solvent in the combined slurry is evaporated, and the powder is further comminuted by jet miffing until the average particle size is less than 5 micrometers, as determined by particle size analysis.
(5) The powder is then uniaxially compacted into a disc or other shape using a single or double acting die and a pressure of 2,000 to 10,000 psi. We prefer a steel die.
(6) The compacted pellet is then isostatically pressed at 15,000 to 45,000 psi (and, preferably, 20,000-25,000 psi) but pressures outside this range could be used. Lower pressures would result in, so we have not tested beyond that. The compacted pellet is typically protected in an evacuated, and sealed neoprene bag prior to isostatic pressing.
(7) Either before or after isostatic pressing, the SBCO seed crystal is placed on the pellet surface in an appropriate location and with the appropriate orientation. The size of a typical seed crystal is about 1 to 2 mm in diameter. The seed crystal can also be included within the powder compact during the initial compaction stage in step 5.
(8) The pellet with the seed crystal is typically placed on the horizontal stage within a vertical tube furnace. Multiple heating zones along the length of the vertical tube aid in maintaining the desired vertical thermal gradient.
(9) The bottom of the furnace tube is closed to prevent excessive convective air flow, and the top of the furnace tube is covered with an optically transparent aperture (typically made from fused silica or sapphire). The ceramic furnace tubes used have been made from silica, alumina, or mullite.
(10) The furnace stage, on which the YBCO pellet rests, can be raised or lowered until the proper crystal growing conditions of (a) temperature at the pellet center and (b) radial thermal gradient are achieved.
(11) A radial thermal gradient within the range of 1-20° C. per inch of radius is typically used, along with vertical thermal gradient of 1-20° C. per inch of specimen.
(12) The furnace is heated to raise the temperature of the specimen at a rate of 100 to 500° C. per hour to an upper temperature of between 1010 and 1050° C. This temperature is held for 0.1 to 2 hours.
(13) The specimen temperature at the SBCO seed location is lowered at from 1-10° C. per hour. A temperature of between 1040-1000° C. is adequate for 123 YBCO crystal nucleation from the surfaces of the SBCO seed crystal.
(14) Following crystal nucleation, the specimen temperature is lowered at from 0.1 to 1° C. per hour to allow for grain growth to proceed both radially and vertically. A typical temperature range for this step is from 1039 to 950° C.
(15) Following completion of the crystal growth the furnace is cooled at a rate of 10-200° C. per hour to room temperature.
(16) After removal of the crystal from the cooled furnace, the 123 YBCO single crystals are reheated to 400-600° C. at a rate of 10-100° C. per hour in an oxygen-rich atmosphere for 10-10,000 hours for annealing. Following oxygenation, the crystals are cooled at from 5-100° C. per hour to room temperature.
(17) The final step in single crystal fabrication is to machine the single crystal, if necessary, to whatever shape and tolerances are required for the application. This step is often done prior to the oxygenation step.
The oxygenation (step 16) attempts to minimize the value of "x" in the 123 YBCO material.
While we have described preferred embodiments, those skilled in the art will readily recognize alternatives, variations, and modification which might be made without departing from the inventive concept. Therefore, interpret the claims liberally with the support of the full range of equivalents known to those of ordinary skill based upon this description. The examples illustrate the invention and are not intended to limit it. Accordingly, define the invention with the claims and limit the claims only as necessary in view of the pertinent prior art. | We make large (in excess of 2 cm in diameter), single crystal YBa 2 Cu 3 O 7-x [123 YBCO] crystals, where x≦0.6, in a seventeen step process or some variant thereof from finely ground and well mixed 123 YBCO and 211 YBCO powders with a small amount of Pt by controlling the rate of cooling from within a compact of the powders using a temperature gradient in the radial and axial planes (independently) of about 1-1° C./inch diameter of compact to nucleate the crystal growth. We promote crystal growth as well using a samarium oxide seed crystal, preferably SmBa 2 Cu 3 O.sub.(7-y), where y≦1.6. After nucleation we cool the compact slowly at a rate from about 0.1-1° C./hr to promote the single crystal development. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a device which can be used for transporting a handicapped child to and from a bed to a bathtub and supporting the child in the tub while being bathed by an attendant. The device can also be used as a seat.
Various appliances are presently available to aid in bathing invalids or the handicapped. The Dalton U.S. Pat. No. 3,104,399 and Farmer U.S. Pat. No. 2,439,163 are illustrative of hydraulic lifts for raising patients from a bed and transferring them to a chair or bathtub. A similar device is marketed under the name Hoyer Patient Lifter and includes a sling for supporting the patient during the use thereof. The Batty U.S. Pat. No. 3,220,575 also shows a lift. These devices are expensive and difficult to manipulate, particularly in the confines of small bathrooms.
Another category of device is a bath seat which is either a self-supporting plastic bucket seat with a support harness or a frame with a web or sling which is supported on a frame within the tub to support the handicapped child or patient while being bathed by an attendant. A device of this character is advertised in "The Exceptional Parent" of August 1978 by LaCaron Industries, Inc. A device called a Support-A-Bather, employing a metal tubular frame and hammock sling, is sold by Modular Medical Corporation. Rehabilitation Engineering of the Ontario Crippled Children's Center, Toronto, Ontario, markets a bath frame which employs a tubular steel frame with suction cups and lawn chair webbing to support a child. U.S. Pat. No. 3,999,227 also shows a sling seat supported on a metal frame.
Palmco Engineering sells a bathtub seat having a web with a zipper to enable lowering a patient's head to facilitate hair washing.
SUMMARY OF THE INVENTION
The present invention provides a relatively simple and inexpensive appliance by which a handicapped child can be transported from a bed to a bathtub and the patient and appliance placed in the tub without the attendant handling the entire weight of the patient. The appliance includes an elongated, generally rectangular frame with a foot run, head run, interconnecting side runs and a U-shaped fulcrum frame which surrounds the fabric seat to protect the patient. The fulcrum frame provides a fulcrum which is placed on the edge of the bathtub and enables lifting of the lower foot end of the frame upwardly to clear the edge of the tub. When the foot is elevated to clear the edge of the tub, the appliance is swung or pivoted about a vertical axis to place the foot end in the tub to support the appliance and patient, and then the patient and appliance are lowered as a unit into the tub by shifting the fulcrum bar from the edge of the tub. More specifically, wheels at the foot run provide a pivot for swinging the entire frame and patient as a unit laterally onto the edge of the tub, and the fulcrum bar, when rested on the side of the tub, enables the attendant to swing the foot portion upwardly and horizontally over the rim of the tub and then lower the foot portion into contact with the tub bottom, whereupon the fulcrum bar can then be lowered onto the floor of the tub, supporting the patient at an inclined sitting position in the tub. Wheels on the fulcrum bar aid in transporting the appliance on the floor.
Alternatively, the patient and appliance can be loaded in the tub by approaching the tub with the device at right angles to the longitudinal axis of the tub, tilting the appliance rearwardly about the wheels on the fulcrum bar to raise the front wheels above the rim of the tub. The frame can then be slid into the tub for a portion of its length and the attendant then picks up the appliance and patient and slides the frame over the tub rim. When the front wheels have contacted the bottom of the tub, the head end of the frame is swung into the tub.
A deep pocket in the web, which extends well below the side runs, forms a seat for the patient and, together with a seat belt, securely retains the patient in the appliance. The web is loose adjacent the frame foot portion to form a slight recess or pocket for the feet to aid in positively positioning the patient on the appliance. Foot straps are also provided.
The foot and head ends of the web are fastened to the frame by straps held by Velcro fasteners or the like. Hence the head panel can be released to enable lowering of the back of the patient's head in the water to facilitate shampooing.
Further objects, advantages and features of the invention will become apparent from the disclosure hereof.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the bathing appliance of the invention.
FIG. 2 is a side elevational view thereof.
FIG. 3 is a plan view of the appliance shown in FIG. 2.
FIG. 4 is an end view of the head end of the appliance shown in FIG. 2.
FIGS. 5, 6, 7, 8, 9 and 10 are diagrammatic views showing the sequence of loading a patient from a bed into the appliance, transporting the patient to a bathtub and loading the patient and appliance into the tub as a unit.
FIG. 11 is a diagrammatic plan view showing the pivot action of the appliance on the side of a bathtub.
FIG. 12 is a perspective view showing the loading technique illustrated in FIG. 11.
FIGS. 13 and 14 show an alternate technique for loading the patient and appliance as a unit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.
FIG. 1 discloses an appliance 10 which includes a frame 12 and a mesh fabric web 14 which is supported by the frame 12, as subsequently described. The frame includes a mid or center portion 16 which has two side runs 18 and 20 and a U-shaped fulcrum frame 21 having a fulcrum bar 22 connected by leg portions 24 and 26. The frame also includes a foot section 25 with two side runs 27 and 28 connected by a cross run or foot run 30. The head section 32 includes side runs 34 and 36 and an inclined head rest portion 38. The ends of the foot and head frame sections interfit in telescopic relationship with the center frame 24. Apertures 37 and screws 29 can be employed to hold the telescoped frame parts in assembly. A sufficient number of apertures 37 are provided to afford adjustment of the length of the foot section. In Europe, where typical tub heights are 21 inches as compared with 15 or 16 inches in the United States, the additional length and the extended foot section provides better stability for the patient when loading the patient in the tub as hereinafter described.
The foot run 30 is provided with two casters or wheels 40 and 42 which are rotatably supported by ears or tabs 44 which are welded to the frame run 30. The center frame is provided with ears 50 which are welded to the fulcrum bar and which rotatably support wheels 46, 48.
The web 14 is desirably formed of one piece of mesh or imperforate material to enable drainage and has marginal sleeves 74 supporting the sides of the web on the side runs of the frame sections. The foot section runs 27 and 28 are inserted into sleeve openings 75, 77 and the head section runs 34, 36 are inserted in the sleeve openings 79, 81. Gaps 72 in the sleeves intermediate the ends (FIG. 4) enable insertion of the side runs 16, 18 of the central frame section, with the legs 24, 26 extending through the gaps. The foot end of the web is fastened to the frame by one or more straps 80 which are wrapped around the run 30 and secured with a Velcro fastener at the end. The head end of the web is secured to run 38 by straps 82 which are wrapped around the frame portion 38 and secured with Velcro fasteners. The web 14 is also provided with straps for holding the invalid on the appliance. Leg or foot straps 84, leg straps 86 and a waist strap 88 are provided. The straps are stitched to the web fabric. The web 14 also has a formed-in seat portion or deep pocket 90 which retains the hips of the invalid well within the side frames during use. The pocket also lowers the center of gravity of the device to prevent tipping when the appliance and patient are unattended. Looseness of the web in the foot portion helps positively position and retain the patient against shifting.
The pocket 90 is desirably located within the fulcrum frame so that the frame will protect the patient's hips and buttocks. Moreover, when the appliance is being pivoted as illustrated in FIG. 8, the pocket is located so that the appliance is balanced with respect to the fulcrum bar for maximum stability as the appliance is swung laterally. When the appliance is at rest in the FIG. 2 position, with all wheels on the floor or ground, the center of gravity is desirably forwardly of the wheels 46, 48 so the appliance won't tip backward.
In use, the appliance can be positioned on a bed adjacent to the patient (FIG. 5) and the patient placed on his or her side and shifted laterally onto the appliance and strapped in place. The patient and appliance can then be rolled into the upright position on the bed and the front wheels lowered onto the floor. When the appliance is in the FIG. 5 position, the laterally projecting fulcrum frame aids in supporting the frame and patient. In FIG. 6, the attendant 100 is transporting the patient 99 either with all four wheels on the floor or with the front wheels 40, 42 on the floor, depending on the weight of the patient and the height of the attendant.
To load the patient and appliance into the tub, as illustrated in FIGS. 7-11, the appliance is moved parallel to the side of the tub, as illustrated in FIG. 7. In FIG. 7 the attendant has lifted the fulcrum bar 22 up and placed it on the edge or rim 104 of the tub 106, with the foot section 25 remaining exteriorly of the tub. The attendant then pivots the device to raise the front wheels upwardly, as illustrated in FIG. 8, to clear the rim 104. The foot 24 is then swung over the rim, as illustrated in FIG. 11, so that the front wheels can be placed in the tub, as illustrated in FIG. 9. The patient and appliance can then be lowered into the tub, as illustrated in FIG. 10. When the device is supported in part on the edge of the tub, as illustrated in FIGS. 7, 8 and 9, the angle A between the wheels and the fulcrum support is such that there will be clearance between the bathtub side rail 104 and the wheels so as not to interfere with the swinging movement of the device during the FIGS. 7 through 9 sequence. It is also desirable that the wheels extend rearwardly at an appropriate angle to minimize the height of the appliance when in the tub for maximum immersion of the patient. The angle of the tabs holding the front wheels 40 and 42 is also intended to minimize the overall height of the patient in the tub.
FIG. 12 shows the patient and appliance being supported on the fulcrum bar on the rim of the tub during the pivoting or swinging action to place the foot end of the appliance in the tub prior to lowering the fulcrum bar to the bottom of the tub. Referring to FIG. 2, certain dimensional relationships of the components have been found to maximize the advantages of the invention and position the seat portion 91 of the pocket 90 in a generally horizontal position when the device is in the FIG. 7 and FIG. 9 positions. An appliance with a length L of 471/2 inches and height H of 20 inches and pocket depth P of 8 inches has provided good results. With these dimensions, the angle B (FIG. 2) of 15° to 20° will provide an angle C (FIG. 7) of between 35° and 45° to hold the seat horizontal. An angle higher than 50° will not provide the desired stability and security for the patient during manipulation into the tub. Adjustment of the length of the foot section to provide an angle within this range is desirable.
If it is desired to lower the patient's head partially in the water to facilitate washing and shampooing, the straps 82 can be unfastened and the head portion of the web pushed down on the frame over the tubes a selected amount to enable lowering of the patient's head the desired depth.
FIGS. 13 and 14 show an alternate procedure for loading the appliance and patient into the tub. In FIG. 13 the appliance 10 is approaching the tub at generally right angles with the longitudinal center line 120 of the tub. The appliance is tilted rearwardly about the fulcrum frame 22 and the wheels 48 to lift the foot end 25 above the rim 123 of the tub. The front frame sections 27 and 28 are then slid over the rim of the tub and the patient and appliance tilted as illustrated in FIG. 14 to touch the front wheels on the floor of the tub. Once the front wheels have touched the floor of the tub, the patient and appliance are swung to align the appliance with the longitudinal center line 120 of the tub and the patient is lowered into the tub. The sequence can be reversed for removing the patient and appliance from the tub. With the technique illustrated in FIGS. 13 and 14, as with the technique previously disclosed, the attendant does not have to handle the entire load at all times because the rim 123 of the tub supports part of the load.
A skidproof coating 93 on the bar 22 facilitates handling of the device on the tub rim.
The use of straps with Velcro fasteners enables adjustment of the length of the frame to accommodate patients of different heights. However, other types of fastening techniques could be employed. | Disclosed herein is an appliance for transporting an invalid or handicapped patient to and from a bathtub and for supporting the patient while in a tub. An elongated generally rectangular frame is provided with a web having a pocket which forms a seat for the patient, with the pocket surrounded by a U-shaped fulcrum bar which protects the patient's hips and buttocks. The fulcrum bar enables loading of the appliance into the tub without the attendant handling the entire load. The appliance can also be used as a comfortable, stable all purpose seat for a handicapped patient. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to automatic adaptive equalizers such as are used in high speed quadrature-amplitude modulation (QAM) data communications equipment. (The term QAM is used herein broadly to include all systems in which the transmitted signal can be represented as the superposition of two modulated signals, each being obtained by pulse-amplitude modulation of a signal sequence on a sinusoidal carrier, the two signal sequences being generated in synchronism at the same rate, and the two carriers being of the same frequency but 90° apart in phase. QAM thus includes a wide variety of double sideband systems, including pure phase modulation and combined amplitude and phase modulation.) The invention is particularly useful in a multi-point data transmission system in which a central station communicates with a number of remote stations.
It is common practice to adapt the equalizer in a receiver to the particular channel and transmitter from which it is to receive a signal burst, by using a known training sequence as part of a preamble of the burst. One review of prior equalization art is Proakis and Miller, IEEE Trans. Inf. Theo., Vol. IT-15, No. 4, 1969.
Typically, the preamble also includes signals for initial adjustment of other receiver parameters. In particular, the first segment of the preamble typically contains a sequence for initialization of the timing recovery circuitry, to optimize the timing epoch τ, where output signals are put out by the receiver at times kT + τ, k = 0, 1, . . . , the receiver being adapted to receive signals as 1/T signals per second. The timing recovery sequence precedes the equalizer training sequence in conventional systems because improper setting of τ may interfere with proper equalization.
SUMMARY OF THE INVENTION
The invention makes possible training of the equalizer without regard for the value of the timing epoch, so that the timing recovery segment of the preamble preceding the training sequence may be eliminated. Accordingly, equalizer training may begin as soon as signals reach the desired principal tap coefficient location in the equalizer, and the overall length of time required for set up of the receiver is thus substantially shortened, increasing the data capacity of the receiver. This is particularly important in multi-point operation, where the central receiver must repeatedly adapt itself to communication with different remote transmitters. In addition, the insensitivity of the equalizer of the invention to timing epoch makes possible simplification of the timing recovery circuit. Further, the overall delay length of the equalizer may be reduced.
In general, the invention features spacing the equalizer taps apart by T/n seconds, where n is greater than TB, where B Hz is the bandwidth of the transmitted signal, and providing control circuitry for early actuation of the equalizer tap adjustment circuitry to begin adjustment of the tap coefficients and hence training of the equalizer regardless of the initial value of the timing epoch. In preferred embodiments the receiver includes detection circuitry for detecting the beginning of an incoming burst of signals, and the control circuitry comprises means for actuating the adjustment circuitry within a predetermined time interval after such detection, wherein that time interval is preferably less than the total delay length of the equalizer; n is an integer preferably equal to 2; the receiver includes sampling circuitry for sampling received signals at a rate of n/T samples per second and providing the samples to the equalizer; the receiver is part of a central station in a multi-point transmission system having in addition a central transmitter and a number of remote transmitter/receiver stations, and each remote transmitter is adapted to send a training sequence as a preamble of each burst, and the control circuitry of the central receiver comprises means to actuate the adjustment circuitry to begin training of the equalizer with the first signals in the preamble; the receiver includes timing recovery circuitry for adjusting τ, and the control circuitry comprises means for actuating the adjustment circuitry prior to any substantial adjustment in τ by the timing recovery circuitry; the control circuitry comprises means for actuating the adjustment circuitry to begin training of the equalizer when the first signal in the burst has arrived at a pre-selected tap position in the equalizer at which it is desired to locate the principal tap coefficient; and the timing recovery circuitry comprises means for keeping the principal tap coefficient within a predetermined number of taps from the center of the equalizer.
T/2 tap spacing in an equalizer is disclosed in Lucky U.S. Pat. No. 3,617,948, in a single sideband (SSB) receiver, although without suggestion of the present invention. (Since correct setting of initial local carrier phase is important in SSB and vestigial sideband (VSB) receivers, an initial segment of preamble is normally required in such receivers to set up the carrier recovery circuit, so that use of T/2 tap spacing would not substantially reduce preamble length, even though it would make equalizer performance relatively independent of timing epoch.) Lucky employs the odd numbered taps to do spectral shaping, simplifying his low pass filter. In some instances receivers embodying the present invention may also carry out some spectral shaping in the equalizer, although for fast training a good quality low pass filter is still necessary to facilitate rapid convergence of the tap coefficients and optimum equalizer performance.
Other advantages and features of the invention will be apparent from the description and drawings herein of a preferred embodiment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a multi-point data communications system;
FIG. 2 is a schematic diagram of a receiver embodying the invention;
FIG. 3 is a schematic diagram of an equalizer embodying the invention; and
FIG. 4 is a schematic diagram of a timing recovery circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of a multi-point data transmission system. A single transmitter 10 at a central site broadcasts data and control information to a number of remote receivers 11 1 , 11 2 , . . . on a common outbound line 12. In return, the remote transmitters 13 1 , 13 2 , . . . transmit over a common return line 14 to the central site receiver 15. The remote transmitters are selected in turn by the central site transmitter to send non-overlapping bursts of signals. Each burst includes information preceded by a preamble that allows the central site receiver to initialize and prepare itself for data reception from that transmitter. The preamble represents overhead time that is wasted for data transmission purposes, and therefore should be minimized.
FIG. 2 is a block diagram of a receiver for a QAM modem. The received signal is passed through an automatic gain control (AGC) circuit 21 that normalizes the received power, and a filter 22 that rejects out-of-band noise. A carrier detect circuit 23 monitors the received signal and puts out a "carrier present" logic signal when the power in the received signal exceeds a predetermined threshold level. The output of the AGC and filter is demodulated by both an in-phase local carrier 25, cos[W c t + θ(t)], and a quadrature local carrier 26, sin[W c t + θ(t)], which are generated by a carrier recovery circuit 27. Here W c is the nominal carrier frequency in radians/sec and θ(t) is the instantaneous phase of the carriers generated by the carrier recovery circuit. The in-phase and quadrature demodulated signals 28 and 29 are passed through identical low-pass filters (LPFs) 30 and 31 to remove unwanted second harmonic terms and provide some spectral shaping of the data signal. The filtered outputs 32 and 33 are sampled at intervals determined by a timing recovery circuit 34 whose inputs are the filtered outputs 32 and 33. In conventional receivers the sampling occurs at times kT + τ, k = 0, 1, 2, . . . , k is an index denoting the sampling time. The sampled outputs 35 and 36 are digitized in A/D converters 37 and 38, and the two resulting digital numbers ReZ k and ImZ k are regarded as the real and imaginary parts of a complex signal value
Z.sub.k = ReZ.sub.k + iImZ.sub.k
where
i = √-1, k = 0, 1, 2, . . . .
The complex numbers Z k then pass through a complex baseband equalizer 39, which uses complex arithmetic to compute complex equalized output values according to the formula ##EQU1## where the N tap coefficients g j , O≦j≦N-1, are digital complex numbers that are stored in the equalizer and determine its characteristics. Finally, the equalized outputs y k are entered into a decision-and-error circuit 40 which in data (decision-directed) mode decides which complex data signal d k must have been sent by the transmitter, and then computes the complex apparent error signal e k = y k - d k . During training mode (initial adjustment of the equalizer) the transmitter sends known, predetermined data signals d k which are also generated in the receiver by training mode control circuit 41 to compute the error signal e k . The error signal is used to adjust the equalizer tap coefficients g j and the carrier recovery circuit phase. The decisions d k represent the transmitted data and are converted to a serial bit stream 42 in a data out circuit 43 for delivery to the user.
The place where analog-to-digital conversion occurs in such a receiver is a design choice that is highly conditioned by the available technology. In early implementations the equalizer was often implemented as an analog transversal or tapped-delay-line filter, whose output was sampled at T-second intervals to give the equalized outputs y k . More recent implementations realize nearly the whole receiver digitally, with digitization immediately after the AGC.
The initial adjustment of such a receiver is conventionally performed as follows. The remote transmitter first sends a very simple first segment of the preamble with strong spectral components at the band edges of the transmitted spectrum. The receiver carrier detect circuit detects the appearance of energy on the line and causes the receiver to start its initialization or training procedure. The AGC is put into a fast, high-gain mode and quickly establishes the proper signal level. The timing recovery circuit uses the strong band-edge spectral components to make an initial determination of the best sampling epoch τ. The carrier recovery circuit may also initialize its phase and frequency at this time, although in a QAM system with a complex equalizer this is not necessarily required since the equalizer is capable of removing any phase offset, and frequency offsets are typically not bothersome. The remote transmitter then changes to a pseudo-random training pattern suitable for training the equalizer.
In a conventional system of the general type described thus far the setting of the sampling epoch τ determines the effective sampled-data frequency response of the channel, which the equalizer must equalize. Improper setting of τ may make the equalizer's job more difficult or impossible; the residual intersymbol interference after equalization is strongly a function of τ. Therefore the initial setting of τ during the first segment of the preamble is critical.
According to the invention, equalizer performance is made practically independent of τ by taking the samples in FIG. 2 at intervals of T/2 seconds, and by making the equalizer tap spacing T/2 seconds. For typical channels the equalization performance (residual intersymbol interference) with N taps spaced T/2 seconds apart and with any sampling epoch is comparable to the performance of a conventional equalizer with the same number N of taps spaced T seconds apart with the optimal sampling epoch, even though the time-domain response of the equalizer of the invention is only half as long. The criticality of the sampling epoch τ is thus eliminated with no economic penalty.
A principal feature of the invention is elimination of the first segment from the conventional training preamble. The transmitter may now simply start with a pseudo-random training sequence; the receiver detects the beginning of a signal burst when energy appears on the line and starts adjusting the equalizer without initializing the sample timing epoch or local carrier phase. (As before, the AGC can be made to settle very quickly.)
A suitable adjustment algorithm for the equalizer is the so-called least-mean-squares (LMS) algorithm of Widrow and Hoff (1960 WESCON Convention Record, IRE, Pt. 4, pp. 96-104), as described in complex form by Proakis and Miller, supra. The procedure is illustrated in FIG. 3, which is a schematic representation of a complex equalizer with taps spaced T/2 seconds apart. The equalizer inputs 50, a sequence of complex numbers Z k representing the LPF outputs sampled T/2 seconds apart, are available at the taps 51 0 , 51 1 , . . . , 51 N -1 with delays of O, T/2, . . . , (N-1) T/2 seconds respectively. At times kT + τ, k = 0, 1, . . . , the tap outputs are multiplied by the complex tap coefficients 52 0 , 52 1 , . . . , 52 N -1 in complex multipliers 53 0 , 53 1 , . . . , 53 N -1 and the outputs are summed in the complex adder 54 to form the complex equalized output 55(y k ). The complex transmitted signal 56(d k ), which is known during training mode, is subtracted from 55 in complex subtractor 57 to form a complex error signal 58(e k ). Each tap coefficient g j k is then adjusted to a new value g j k +1 according to error signal e k and the tap values Z k -j , O≦j≦N-1, by the following rule: ##EQU2## where a is a small real constant and Z k -j is the complex conjugate of Z k -j . The rule is implemented by complex conjugators 59 0 , 59 1 , . . . , 59 N -1 , complex multiplier 60, complex multipliers 61 0 , 61 1 , . . . , 61 N -1 , complex subtractors 62 0 , 62 1 , . . . , 62 N -1 , and complex registers 63 0 , 63 1 , . . . , 63 N -1 storing the tap coefficients.
Initially all tap coefficients are set to zero. At a predetermined time (approximately half the total delay length of the equalizer in the present embodiment, and preferably no greater than the total delay length of the equalizer to obtain maximum advantage of the invention) after the carrier detect circuit indicates the onset of signal energy on the line, such that the main pulse due to the first preamble signal d 0 should be approximately in the center of the equalizer (or other desired position of the principal equalizer tap coefficient), the adjustment algorithm commences, using d 0 as the first desired output signal in forming the first error signal e 0 = y 0 - d 0 (= -d 0 , since y 0 = 0). The adjustment algorithm then proceeds as indicated above, with adjustments of every tap coefficient every T seconds thereafter. The implementation of the above sequence is shown in FIG. 2. Training mode control 41 has a counter circuit 70 which is set to zero upon receipt of the carrier present signal from circuit 23. The T clock pulse 72 increments the counter by one for each signalling interval T. Read only memory circuit 74 stores the sequences of d k 's forming the training preamble. The T clock pulse causes circuit 70 to emit index k (the number of intervals T since carrier present), which in turn causes circuit 74 to feed to decision and error circuit 40 the preamble d k 's at the desired times (i.e., in the present embodiment, beginning at half the equalizer length after carrier present). Circuit 74 also stores and feeds to circuit 40 a control signal S k , which is 0 prior to training mode, 1 during training mode, and 2 during data mode, to cause the decision and error circuit to operate in the desired mode, and to initialize the equalizer tap coefficients to zero prior to training mode.
Another consequence of the insensitivity of the T/2-spaced equalizer to timing epoch is that the timing recovery circuit can be simplified. Any timing update algorithm that tends to keep the principal equalizer tap coefficients near the center of the equalizer can be used. Indeed, if initially the principal coefficients appear off-center due to inaccurate initial synchronization, they can be slewed back to the preferred center positions by gradual timing adjustments without interruption of data transmission, provided that adjustments are slow enough that the equalizer coefficients can continually adapt in response. It will be apparent from the discussion of the equalizer above that a feature of the invention is that equalizer training begins prior to any substantial adjustment of τ by the timing recovery circuit.
FIG. 4 illustrates a representative timing recovery circuit of this type. During each signalling interval T the equalizer tap coefficients 80 are searched by scanning circuit 81, which determines the index j max of the tap coefficient g j of largest magnitude. If j max is less than the desired value, say j 0 , then the epoch of the sampling clock is advanced by some small increment Δ; if j max is greater than j 0 , then the sampling epoch is retarded by Δ, while if j max = j 0 , no adjustment is made. This can be done, for example, as follows: let Δ be chosen so that T/2 = MΔ, where M is a large integer; then use a high-frequency clock 82 of period Δ and a divide-by-M countdown chain 83 to generate the sample time clock 84, with a nominal period of T/2; finally, when the sampling time adjustment logic 85 indicates "advance," arrange the countdown chain to count to (divide) by M-1 instead of M, and on "retard" count to M+1. Thus the index of the largest tap coefficient will tend to move toward j 0 and remain there. The rate of timing epoch change depends on the value of Δ, which should be chosen sufficiently small that the equalizer tap coefficients can adapt in response to changes in the timing epoch.
Another advantage of the T/2-spaced equalizer is that it has approximately half the delay of the conventional equalizer, since the total number of adjustable taps required for a given equalizer is not changed by T/2 spacing. This means less delay in starting to receive transmissions from remote transmitters, and thus yields another reduction in overhead time in multi-point applications. Also, since the equalizer is in the carrier recovery loop in FIG. 2, it allows faster carrier tracking, which is of particular advantage during initial training.
Tap spacings T/n other than T/2 may be used, provided that the demodulated and low-pass-filtered signal has no significant spectral components above (n/2T) Hz. If the bandwidth of the transmitted signal is B Hz, then the demodulated signal will have no significant spectral components above B/2 Hz, so that the constraint on n is that n be greater than TB. It is impossible in principal (by Nyquist's sampling theorem) for TB to be less than 1, but in QAM modems that use bandwidth efficiently TB is typically not much greater than 1. Therefore, n could usually be smaller than 2, which might be of advantage when analog equalizers using tapped delay lines are used. In the broadest view of the invention n need not be an integer. However, it is very convenient to have T/n an integer fraction of the signalling interval T in order that the equalizer output may be sampled at intervals of T seconds without interpolation, particularly in digital implementations. Since there are normally no spectral components above (1/T) Hz, there is normally no advantage to going to n = 3 or higher integer fractions, so n = 2 is the preferred choice.
Other embodiments (e.g., QAM systems using bandpass equalizers, as to which the same constraints on n apply, etc.) are within the following claims. | In a high speed QAM data communications receiver of the type adapted to receive bursts of signals having a bandwidth B Hz and sent at a predetermined rate of 1/T signals per second over a channel, wherein the receiver includes an automatic adaptive equalizer having taps spaced equally apart, tap coefficient circuitry for repeatedly multiplying the output of each tap by a respective tap coefficient, and adjustment circuitry for adjusting the tap coefficients, and output circuitry responsive to the equalizer for providing output signals at times kT + τ, k = 0, 1, . . . , where τ is a timing epoch, that improvement wherein the taps are spaced apart by T/n seconds, where n is greater than TB, and control circuitry is provided for early actuation of the adjustment circuitry to begin adjustment of the tap coefficients and hence training of the equalizer regardless of the initial value of the timing epoch, whereby the data capacity of the receiver is increased by reduction of the time required for set up of the receiver. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electrical connector provided with a front-mounted retainer, and in particular to an electrical connector having an increased creeping distance between its sockets.
2. Prior Art
It is known to hold a terminal firmly in a housing using a doubly-stopped retainer. For a water-proof electrical connector, a common double-stopping system utilises a front-mounted retainer, that is to say one which is inserted from the front of the connector housing. A front-mounted retainer is generally used because it is undesirable to provide an opening for attachment of a retainer on the side of a connector housing. FIGS. 8 and 9 of the drawings show an example of a front-mounted retainer 63, together with an associated female electrical connector 61. The connector 61 includes a main body 61a formed with a plurality of parallel sockets 62 into which female terminals are insertable. The retainer 63 is attached to the main body 61a from its front so that it covers the front portion of the main body after attachment. The retainer 63 is formed with apertures 64 which align with the sockets 62 when the retainer is attached to the connector 61. A pin of a respective terminal of a corresponding male connector (not shown) fits into each aperture 64. The retainer 63 is provided with a respective deformation regulating member 67 within each aperture 64. In use, each of the members 67 enters a recessed portion 66 of a respective lance 65 provided in each of the sockets 62.
During assembly, when a female terminal is inserted into its socket 62, the corresponding lance 65 serves as a first stop by resilient engagement therewith. Then, as shown in FIG. 9, when the retainer 63 is attached, each deformation regulating member 67 enters the recessed portion 66 of the respective lance 65, thereby preventing it from bending. The deformation regulating member 67 thereby serves as a second stop, and consequently double-stopping is effected.
Where this type of connector comes in contact with water, and water reaches the mouths of its sockets 62 so that a film of water covers the spaces between the sockets, there is a danger of electrical shorting between proximally located terminals via the film of water. One way of reducing the chance of this happening, is to provide ribs between adjacent sockets 62 on the front surface of the main body 61a. The ribs thus define tortuous water flow paths between adjacent sockets (by increasing the "creeping distance" therebetween), thereby preventing a film of water from extending continuously over the adjacent sockets 62, and so preventing an electrical short.
Unfortunately, as the ribs are formed on the front surface of the main body 61a, there is a danger of the ribs breaking during, for example, transportation. Moreover, where a front-mounted retainer is used, the ribs get in the way during attachment of the retainer, making it difficult to attach the retainer.
The aim of the invention is to provide an electrical connector which has an increased creeping distance between its sockets, even when the connector is used with a front-mounted retainer.
SUMMARY OF THE INVENTION
The present invention provides an electrical connector comprising a housing, a plurality of parallel cavities formed in the housing for receiving terminals, and a retainer fitted to the housing from a first end thereof, a respective resilient lance being provided in each of said cavities, each lance being formed with a recess portion, the lances resiliently engaging terminals positioned in said cavities as the retainer is fitted to the housing, the lances thereby constituting first terminal stop means, the retainer being formed with a plurality of terminal insertion apertures which open onto a front face of the retainer and are contiguous with said cavities, and a respective deformation regulating member is provided for each terminal insertion aperture, the deformation regulating members being insertable into the recessed portions of the lances as the retainer is fitted to the housing, thereby regulating the deformation of the lances to constitute second terminal stop means, characterised in that the front face of the retainer is formed with elongate water diversion members between the adjacent terminal insertion apertures.
Since the water diversion members are provided between the terminal insertion apertures that are adjacently located on the front face of the retainer, when the retainer is attached to the housing, the creeping distance between the cavities, which are formed so as to be continuous with the terminal apertures, is increased. In other words, the connector of the invention allows, even in the case where a front-mounted retainer is used, an increase in the creeping distance between the cavities, and the effective prevention of electric shorting between terminals inserted into said cavities.
In a preferred embodiment the elongate water diversion members mate with complementary members formed on a face of complementary connection means to which the connector is to be connected. In this case, when the connector, having the retainer attached thereto, is fixed to the complementary connection means, the water diversion members of the retainer mate with the complementary members of the connection means. This results in the connector being fixed to the connection means with the front face of the retainer and an insertion face of the connection means making contact. In addition, the connector fits snugly with the connection means since, when the connection means is inserted, the retainer matingly engages the connection means.
The elongate water diversion members may comprise ribs or recesses.
Advantageously, the elongate water diversion members comprise upstanding ribs, thus arrangement permitting a more compact arrangement of terminal insertion apertures. This arrangement is especially advantageous where the complementary connection means comprises an injection moulded connector having protruding male terminals. Such terminals are relatively far apart and thus the terminal housing is able to accommodate corresponding recesses to receive the upstanding ribs of the retainer without increasing the spacing of adjacent terminals which would result in an enlarged connector.
Preferably, the retainer and the connector housing are provided with inter-engageable means for locking the retainer to the housing. The inter-engageable means may be constituted by claw members formed on the retainer and stop members formed on the housing, and by projections formed on the retainer and grooves formed within the housing.
The housing and the retainer may each be integrally moulded from a synthetic resin material. The cavities may be defined by tubular members integrally moulded with the housing.
Preferably, the connector is a female connector, a respective female terminal being positioned in each of said cavities.
The invention also provides a connector assembly comprising a female connector as defined above and a complementary male connector, the male connector being provided with male terminals for engagement within the female terminals.
Advantageously, the male connector and the female connector are provided with inter- engageable means for locking the two connectors together.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail, by way of example, with reference to FIGS. 1 to 7 of the drawings, in which:
FIG. 1 is an exploded perspective view of a female connector constructed in accordance with the invention;
FIG. 2 is a longitudinal sectional view showing the connector of FIG. 1 prior to the attachment of its retainer;
FIG. 3 is a longitudinal sectional view showing the connector of FIG. 1 prior to the attachment of a complementary male connector;
FIG. 4 is a perspective view showing the male connector;
FIG. 5 is a front elevation of the male connector;
FIG. 6 is a perspective view showing the connector of FIG. 1 prior to the attachment of the male connector; and
FIG. 7 is longitudinal sectional view showing the connector of FIG. 1 after the attachment of the male connector.
FIGS. 8 and 9 are sectional views of an electrical connector known in the prior art.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 shows a water-proof female connector F comprising a housing 1, a water-proof seal 2 and a retainer 3.
The housing 1, which is integrally moulded using synthetic resin material, has a main body 5, from which an inwardly-stepped front portion 7 extends (towards the left in FIG. 2). This front portion 7 is covered by a hood member 6. The main body 5 is of a generally rectangular configuration when seen from the front. Five generally tubular members 8 project from the front face of the main body 5, three of the tubular members forming a lower level, and the remaining two members forming an upper level. The tubular members 8 of the upper level are located above the spaces between the three tubular members of the lower level.
The hood member 6 is also of a generally rectangular configuration when seen from the front.
As shown in FIG. 2, the main body 5 is formed with sockets 11 for receiving female terminals 10, the sockets each extending from the rear face of the main body to the front face of a respective tubular member 8. The rear of each socket 11 defines a circular aperture 12, and the front thereof defines a generally rectangular aperture 13. Each terminal 10 is connected to a respective electrical wire 15, and a respective water-proof rubber seal 16 is fitted tightly into each circular aperture 12 around the respective electrical wire. Each terminal 10 is formed with a box-shaped main body 17 which fits within a respective aperture 13.
A respective lance 20 is formed on that surface of each socket 11 which defines the base of the associated aperture 13. Each lance 20 is a resilient fit within an aperture 18 formed in the lower surface of the main body 17 of the associated female terminal 10. Each lance 20 is resiliently deformable in the direction of a recessed portion 26 formed on its underneath surface. Each socket 11 is formed with terminal insertion aperture 22 at its front end. Each terminal insertion aperture 22 is arranged to receive a pin 46 of a male terminal 45, to be described later.
The water-proof seal 2 is made of rubber, and is generally rectangular when seen from the front. The water-proof seal 2 is arranged to fit around the front portion 7 of the main body 5 of the housing 1.
The retainer 3 is also integrally moulded from synthetic resin material. In use, it covers the periphery of the tubular members 8 of the housing 1, and fits around the front portion 7 of the main body 5. The rear face of the retainer 3 (the right-hand side in FIG. 2) is formed with five insertion apertures 24 which receive the respective tubular members 8. Each insertion aperture 24 is formed with a mouth 25 which fits around a respective terminal insertion aperture 22 of an associated socket 11. A respective deformation regulating member 27 is provided on that surface of the retainer 3 defining the base of each insertion aperture 24. When the retainer 3 is attached to the housing 1, each deformation regulating member 27 enters the recessed portion 26 of the lance 20 provided in the respective socket 11, thereby regulating the deformation of that lance.
A flange 28 is formed on the periphery of the rear face of the retainer 3, the flange serving to stop the attached water-proof seal 2 from coming loose. A respective resilient stop claw 31 is formed on that surface of the retainer 3 defining the top of each of the upper two insertion apertures 24. The stop claws 31 are arranged to engage behind corresponding stops 30 formed on the upper surfaces of the two upper tubular members 8 of the housing 1. Projections 33 are formed on the opposite side faces of the centrally-located lower insertion aperture 24. The projections 33 are arranged to fit within grooves 32 formed on the external side surface of the corresponding tubular member 8.
As shown in FIG. 3, when the retainer 3 is inserted, and the tubular members 8 of the housing 1 enter the respective insertion apertures 24, the resilient stop claws 31 engage behind the stops 30 as the rear of the retainer strikes the shoulder between the inwardly-stepped front portion 7 and the main body 5 of the housing 1. Furthermore, the projections 33 fit into the grooves 32, thereby attaching the retainer 3 firmly to the housing 1. At this point, the front surface of the retainer 3 is aligned with the front ends of the tubular members 8 and with the front end of the hood member 6. Each tubular member 8 is inserted into the respective insertion aperture 24 until the respective terminal insertion aperture 22 fits within the associated mouth 25 of the retainer 3. Moreover, each deformation regulating member 27 enters the recessed portion 26 of the respective lance 20.
The front face of the retainer 3 is provided with integrally-formed ribs 35 which project therefrom over a predetermined distance. As shown in FIG. 1, the ribs 35 are located between the mouths 25 of the apertures 24, and are formed so as to separate the five mouths.
FIGS. 3 to 6 show a male connector M that is to be fitted to the female connector F. The male connector M has a housing 1 made of synthetic resin material, the housing having a generally rectangular tubular portion 42, opening out to the front (the right-hand side in FIG. 3). The housing 41 has a thick rear face plate 43 integrally formed with the hollow portion 42. The hollow portion 42 is arranged to be insertable between the hood member 6 of the housing 1 and the front portion 7 of the main body 5 of the female connector F. Pins 46 of five male terminals 45 are provided on the inner wall of the rear face plate 43 of the housing 41 so as to project within the hollow portion 42. The male terminals 45 are installed by means of insert moulding, and their other terminal ends project outwardly in a single line from the outer wall of the rear face plate 43.
The inner wall of the rear face plate 43 is formed with grooves 48 provided between the pins 46. The grooves 48 are arranged to mate with the ribs 35.
The upper surface of the housing 41 is formed with a pair of mutually-parallel, longitudinally-extending projections 49 which, in use, mate with corresponding grooves 50 formed in the upper surface of the housing 1. A stop member 51 is formed between the two projections 49 of the housing 41, this stop member engaging, in use, with an aperture 52 formed in a resilient stop member 53 provided between the grooves 50 of the housing 1. As shown in FIG. 3, the stop member 53 is resiliently deformed when the male connector M is fully engaged within the female connector F, the stop member 53 being formed with a central support member 54. Consequently, when the housing 41 of the male connector M is inserted, the stop member 53 strikes the member 51 and is deformed resiliently to push its front end upwards. This allows the insertion to proceed. After the insertion proceeds up to a specified point, the stop member 53 reverts to its original shape, as the stop member 51 enters the aperture 52. This prevents the housing 41 from being removed.
A manually-engageable tab 55 is provided at the rear end of the stop member 53. In order to release the male connector M, the tab 55 is depressed thereby resiliently deforming the stop member 53 to force its front end upwards. This results in the stop member 51 coming out of the aperture 52, thereby releasing the engagement with the stop member 53.
In order to assemble the female connector F, the water-proof seal 2 is fitted around the front portion 7 of the main body 5 of the housing 1. The female terminals 10 are then inserted into the sockets 11, from the rear side thereof. Each female terminal 10 pushes the associated lance 20 downward, thereby resiliently deforming it. When each female terminal 10 reaches the front end of its socket 11, and the respective lance 20 reverts to its original shape and enters the respective aperture 18, thereby resulting in a first stop for the female terminal 10. At the juncture, each water-proof seal 16 fixed around its electrical wire 15 fits tightly into the respective circular aperture 12, thereby water-proofing the sockets 11.
After the insertion of the female terminals 10 is complete, the retainer 3 is attached to the housing 1 from the front side thereof. As described earlier, as the retainer 3 is inserted, the tubular members 8 of the housing 1 enter the corresponding insertion apertures 24. As shown in FIG. 3, when the retainer 3 comes into contact with the front portion 7 of the main body 5 of the housing 1, the stopping claws 31 are stopped by the stop member 30. Moreover, the projections 33 are stopped in the grooves 32, thereby preventing removal of the retainers. At this point, the terminal insertion aperture 22 of each socket 11 enters the mouth 25 of the respective retainer 3. Furthermore, each deformation regulating member 27 of the retainer 3 regulates the deformation of the associated lance 20 by entering the recessed portion 26 thereof. This results in the female terminals 10 being doubly stopped.
If a female terminal 10 is in a half-inserted position, the respective lance 20 projects outwards from the associated recessed portion 26, and the deformation regulating member 27 strikes that lance, thereby preventing the retainer 3 from being pushed into the fully-inserted position. This allows detection of incomplete insertion of a terminal fitting 10.
Once the retainer 3 is correctly positioned, the flange 28 rests against the front face of the water-proof seal 2, thereby maintaining the water-proof seal in its correct position. Moreover, if the water-proof seal 2 is positioned forwardly of its correct position, it is pushed by the flange 28, when the retainer 3 is inserted, into the correct position.
The female connector F and the male connector M are then connected, after they are put to face each other as shown in FIGS. 3 and 6. The housing 41 of the male connector M is guided by the engagement of the projections 49 and the grooves 50; and the hollow portion 42 thereof is inserted between the retainer 3 and the hood member 6 of the housing 1 of the female connector F. The ribs 35 provided on the front face of the retainer 3 mate with the grooves 48 provided on the rear face plate 43 of the housing 41.
As shown in FIG. 7, when the front face of the retainer 3 comes in contact with the inner wall of the rear face plate 43 of the housing 41, as described earlier, the stop member 51 of the housing 41 enters the aperture 52 provided in the stop member 53 of the housing if resulting in the male connector M and the female connector F being fitted together. At the same time, each pin 46 passes through the respective terminal insertion aperture 22 inside each aperture 24 of the retainer 3, and is inserted into the main body 17 of the respective female terminal 10. Accordingly, each male terminal 45 is connected to the corresponding female terminal 10. Moreover, when the male connector M and the female connector F are connected together, the front end of the hollow portion 42 of the housing 41 pushes the water-proof seal 2 onto the exterior of the front portion 7 of the main body 5 of the housing 1. As a result, water-proofing between the female housing 1 and male housing 41 is ensured.
Furthermore, even after providing the water-proofing means described above, there is a possibility of there being a water leak towards, for example, the front face of the housing 1. In order to prevent this, the ribs 35 are provided between the mouths 25 of the insertion apertures 24 of the retainer 3, each mouth 25 being contiguous with a respective socket 11 of the housing 1. Accordingly, the configuration is such as to allow a large creeping distance between the sockets 11. Consequently, if water does enter the insertion face of the housing 1, a film of water is prevented from forming between the front faces of the adjacent sockets 11 by the tortuous paths defined by the ribs 35. As a result, electrical shorting between adjacent terminal fittings can be effectively prevented. It will be apparent that, even a for a connector having a front-mounted retainer, the creeping distance between its sockets can be made large, thereby improving leak-proofing.
The embodiment described above would be modified. For example, instead of providing the front face of the retainer 3 with ribs 35, it is possible to increase the creeping distance by making the front face of the retainer thick and forming grooves between adjacent mouths 25. In this case, it is desirable to provide projections on the insertion face of the corresponding male connector, the projections being arranged to mate with the grooves.
It would also be possible to provide a male connector with the described means for increasing the creeping distance--in this case the ribs or grooves would be provided between the pins 46.
Moreover, the present invention applies equally to a simplified water-proof connector, and has the same effect of improving leak-proofing. | An electrical connector is formed with a plurality of cavities in an ordered way in a housing. A retainer is fitted to the housing to cover the front faces of the cavities. The retainer doubly stops the female terminals by means of deformation regulating members provided therein, each of which enters a recessed portion of a respective lance, thereby regulating its deformation. The lances are associated with the cavities. The front face plate of the retainer has apertures formed thereon that align with the terminal insertion apertures located on the front face of the cavities. Ribs are formed between the apertures and project outwards, partitioning the apertures. Grooves that fit with the ribs are formed on the insertion face of a complementary connector. The creeping distance between the adjacent cavities is increased due to the provision of the ribs. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to surface hardening of steel workpieces. In particular, the present invention is a method of hardening selected surface areas of steel cutting instruments, such as cutting rules or knife blades, using laser beams to perform both surface hardening and stress relief of the workpiece.
2. Description of the Related Art
Typically, hardening of metals has been performed by carburizing, induction heating and, more recently, laser heat-treating. In conventional gas carburizing methods, a steel workpiece is heated in an atmosphere of a selected gas. Materials from the gas dissolve in the surface of the workpart becoming part of the crystalline structure. For example, a steel workpart is heated in an atmosphere of CO 2 causing minute amounts of carbon to be liberated on the surface of the hot metal and to dissolve in the metal. A subsequent heat treatment to form a martensitic microstructure on the surface produces a hard surface. A martensitic microstructure is formed by heating the steel above the critical temperature—the temperature at which the steel changes phases from a ferrite or cementite microstructure to an austenite microstructure—and rapidly cooling, or quenching, the steel to form a new microstructure phase, martensite. Martensite is the hardest of the steel microstructure phases.
However, the rapid cooling required to produce martensite also induces internal stresses within the microstructure that make the martensite brittle. Therefore, a subsequent tempering process is required to relieve these internal stresses. Tempering typically entails heating the steel to a temperature below the critical temperature for several hours. Heating the steel below the critical temperature avoids inducing a microstructure phase change back to austenite, but also reduces some of the hardness of the martensite. The hardness reduction is the result of some of the carbon particles trapped in the martensite being released. Thus, the microstructure before tempering appears as untempered martensite and after tempering the microstructure appears as tempered martensite.
Some drawbacks are present in surface hardening by carburizing. One such drawback is that it is difficult to surface harden only selected areas of the workpart. In order to only harden selected areas, those surfaces not to be hardened must be masked. The masking prevents those surfaces from being subjected to the gas atmosphere, thereby preventing hardening of the masked surface. The masking process is often difficult, time-consuming and unreliable due to the intense heat of the carburizing process. Another drawback of carburizing is controlling the depth of the hardened surface. Carburizing typically requires post-processing machining, such as grinding, in order to obtain the desired hardened case depth. Carburizing also requires an additional tempering process after the quenching process in order to stress relieve the part. Such a stress relief process typically entails placing the workpiece in an oven, often for a period of several hours. This significantly increases both the cost and the amount of time to process the workpiece.
Another known method of surface hardening steel workparts is induction heating. In induction heating, the steel workpart is placed within an induction coil. An electrical current is passed through the induction coil which induces secondary currents to flow along the surface of the workpart. The secondary current flow causes the surface of the workpart to be preferentially heated. As the electrical current in the induction coil is increased, the surface of the workpart is heated above the critical temperature, thus causing a microstructure phase change to austenite. When the workpart is rapidly cooled, or quenched, a martensitic microstructure is formed. Thus, when only a shallow surface of the part is heated above the critical temperature and is rapidly quenched, only the shallow surface is transformed into a martensitic microstructure while the remainder of the part remains unchanged. This shallow surface of martensite forms the hard surface.
However, the rapid cooling induces internal stresses that cause the steel part to become brittle. Therefore, a subsequent tempering process is required to relieve the internal stresses.
Induction heating has some of the same drawbacks as carburizing. Namely, it is difficult to harden only selected surface areas and the steel workpart requires a post-hardening tempering process that is costly and time-consuming.
Additionally, shallow hardened case-depths are difficult to achieve with induction hardening. Typically, the case depth is controlled during induction hardening by producing a higher frequency current in the induction coil. However, common induction heating machines present limitations on the highest frequency available. Common induction heating machines have a frequency limit of about 1 MHz. However, if a case depth of 0.004-0.006 was desired, an induction machine frequency of approximately 10 MHz would be required. Such a machine is costly and commonly only available in Europe.
Induction heating has been the most common method of producing steel cutting rules. Steel cutting rules produced by induction heating generally provide good bendability properties, thereby allowing the rules to be formed into a number of shapes. However, induction heated rules generally have low durability properties, thereby requiring frequent replacement. Additionally, induction heated steel cutting rules require air or liquid quenching during the heat-treating process which causes thin rules to warp and further requires tempering to relieve internal stresses. The tempering process typically lowers the surface hardness previously obtained during the heat treating step. Therefore, common induction hardened rules are typically hardened to only about 55 R c .
Another known method of surface hardening is laser heat-treatment. Various types of lasers are available for heat treating workpieces, including continuous wave CO 2 lasers. Laser heat treatment using a CO 2 laser typically entails applying an absorbent substance, such as black oxide or phosphate coatings, to the surface area of the part to be heated. This coating reduces reflection of the laser beam and focuses the energy of the laser beam to the area to be hardened. The laser beam is then focused, via a lens or the like, which generates an intense energy flux that rapidly heats the surface.
One distinct advantage of laser heat treatment is that the laser beam may be controlled to heat the surface of the metal piece above the critical temperature to a depth of only a few thousandths of an inch or less. Controlling the depth of the heating to this shallow level allows for self quenching. That is, no liquid or air quenching is required. Self-quenching is accomplished by conduction due to the mass and temperature disparity between the portion of the workpart not heated by the beam and the small depth of the surface heated above the critical temperature by the beam. The heat on the surface is quickly transferred to the unheated portion thereby quenching the heated surface. However, the self-quenching process has been taught to be undesirable for thin parts such as knife blades and therefore air or liquid quenching has been particularly advisable. Air or liquid quenching is required due to the insufficient mass of the part to facilitate the conduction. The addition of such air or liquid quenching increases both the cost and the processing time.
One such method of laser-treating steel workparts is disclosed in U.S. Pat. No. 4,304,978. This patent teaches laser heat treating a flat part, such as a knife or blade, by focusing a laser beam perpendicular to the major flat surface of the part using a cylindrical lens. The width of the beam is adjusted according to the desired width of the part to be heated. The part is then moved through the laser or the laser may be moved along the part to heat the surface. U.S. Pat. No. 4,304,978 teaches that thin parts, such as a knife blade, requires gas quenching to prevent melting of the part. Therefore, one shortcoming of U.S. Pat. No. 4,304,978 is that the laser treated part, such as a knife blade, is not self quenching.
Therefore, it is desirable to provide a method of hardening a steel cutting rule or knife blade so as to obtain equivalent or superior ductility properties as common induction heated rules, but with superior wear resistance. It is also desirable that the method provide for self quenching of the cutting rule or knife blade to reduce processing time and cost.
Further, it is desirable to provide a method of stress relieving the heat treated cutting rule that reduces the processing time and cost without weakening the metal part.
SUMMARY OF THE INVENTION
The present invention addresses the foregoing shortcomings of conventional steel hardening techniques by providing a method of surface hardening metal workparts while maintaining the untempered martensitic microstructure and relieving internal stresses, thereby removing brittleness usually characterized with untempered martensite but maintaining the hardness. Additionally, the present invention provides self-quenching of thin workparts, such as cutting rules or knife blades. The present invention accomplishes the above while also producing hardened cutting rules with comparable ductility properties to that of current cutting rules, but with superior durability properties.
The present invention accomplishes the foregoing by providing a process of surface hardening metal workparts by heat treating and stress relieving the parts using laser beams. The process entails first heat treating the parts using a narrowly-focused laser beam and subsequently stress relieving the parts using a laser beam of a lower intensity.
The heat treating process is controlled by adjusting the laser beam intensity in order to obtain a desired case depth, preferably a shallow case depth. The process does not require the parts to be air or liquid quenched since the process results in self-quenching of the parts.
Subsequent to the heat treating process a stress relief process is performed. The stress relief process consists of subjecting the part to the laser beam a second time, usually at a lower intensity than that used in the heat treating process. The stress relief process is controlled so as to only perform stress relief and not to temper the microstructure of the parts. The resultant microstructure after stress relief appears as untempered martensite but without the brittleness usually accompanying untempered martensite.
In one aspect of the invention, metal workparts are surface hardened using laser beams to perform both heat treatment and stress relief of the part. Prior to heat treating, a laser beam is configured to obtain the desired hardness results. After configuring the laser beam, a metal workpart is subjected to the laser beam to perform the heat treatment process. The workpart is preferably passed through the laser beam; however, the laser beam may be traversed across the workpart surface. The heat treating process is performed such that the parts are self-quenching. That is, no air or liquid quenching is required. The heat treating process forms a hard martensitic layer having a microstructure of untempered martensite. Internal stresses created in the untempered martensite layer make the untempered martensitic layer brittle, thereby requiring stress relief.
Subsequent to the heat treating process the workpart is stress relieved by being subjected to a laser beam a second time. The laser beam is reconfigured to obtain the desired results for performing stress relief. The workpart is then subjected to the laser beam for stress relief either by passing through the laser beam or by the laser beam traversing the surface of the part. The resultant microstructure after stress relief appears as untempered martensite. However, the internal stresses have been relieved. Therefore, the hardness of the martensitic layer has been retained but the brittleness has been eliminated.
In another aspect of the invention thin workparts such as steel cutting rules or knife blades are surface hardened. The process entails first heat treating and subsequently stress relieving the cutting rule. Prior to the heat treating process, a laser beam is configured to obtain the desired hardness results. During the heat treating process the cutting rule is fed through the laser beam vertically, in an upright position, such that only the cutting tip of the cutting rule is subjected to the laser beam for hardening. The tip of the cutting rule is hardened by the laser beam to form a shallow hardened case of only a few thousandths of an inch.
The cutting rule is subsequently stress relieved by being subjected to the laser beam a second time. The laser is reconfigured to obtain the desired results for performing stress relief. The cutting rule is then passed through the laser beam, thereby performing the stress relief. The microstructure of the hardened surface after heat treatment but before stress relief appears as untempered martensite. After being subjected to stress relief, the microstructure maintains its appearance as untempered martensite. However, the internal stresses have been relieved, thereby eliminating brittleness.
The process may provide for additional steps such as cleaning the cutting rule prior to the heat treatment process and application of a corrosion inhibitor after the stress relief process. Further, an additional step of applying a laser beam absorbent substance to the surface area to be heat treated may be required depending on the type of laser being used. For example, a continuous wave CO 2 laser beam would require a laser beam absorbent substance, whereas a YAG laser would not require application of the laser beam absorbent substance.
The resultant laser hardened cutting rule performs with the bendability properties of known cutting rules. However, the durability, wear-resistance, characteristics are greater than commonly known cutting rules.
This brief summary has been provided so that the nature of the invention may be understood quickly. More complete understanding of the invention may be obtained by reference to the following detailed description of the preferred embodiments thereof in connection with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of a laser hardening process according to the present invention.
FIG. 2 is a side perspective view of a laser hardening process according to the present invention.
FIG. 3 is an enlarged view of a central laser processing station.
FIG. 4A is an enlarged side view of the laser beam-cutting rule interface.
FIG. 4B is an enlarged front view of the laser beam-cutting rule interface.
FIG. 5 is an enlarged view of the interface shown in FIG. 4 B.
FIG. 6A is a top view of a typical steel rule spring coil.
FIG. 6B is a sectional view of a typical steel rule spring coil.
FIG. 6C is a sectional view of a typical cutting rule after having a beveled edge machined on one side.
FIG. 7 is a flow diagram for a laser hardening process.
FIG. 8 is a flow diagram for a laser hardening process.
FIG. 9A is a photograph of a cross-section of a steel cutting rule before heat treating.
FIG. 9B is a photograph of a cross-section of a steel cutting rule grain microstructure after laser heating but before stress relief.
FIG. 10 is a photograph of a cross-section of a steel cutting rule grain microstructure after being both laser heat treated and stress relieved.
FIG. 11 is a photograph of a cross-section of a steel cutting rule after being surface hardened by induction heating.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, a detailed description of the preferred embodiments according to the present invention will be described.
FIG. 1 is a top perspective view and FIG. 2 is a side perspective view of a laser hardening process setup according to one aspect of the present invention. As seen in FIG. 1 and FIG. 2, a laser heat-treating process setup for laser hardening a steel cutting rule contains a central laser processing station 1 , a start/finish station 2 and an intermediate takeup station 3 . Located between start/finish station 2 and central processing station 1 are cleaning station 4 , laser absorbent applying station 5 , laser absorbent drying station 6 , and corrosion inhibitor applying station 7 . Located along a path connecting start/finish station 2 , cleaning station 4 , laser absorbent applying station 5 , drying station 6 , central laser processing station 1 and takeup station 3 are a means for guiding steel cutting rule 14 through the various processing stations, such as guide rollers 11 .
Start/finish station 2 and takeup station 3 provide a means for retaining cutting rule 14 during the laser hardening process. The function of stations 2 and 3 is to retain cutting rule 14 , whatever the form, during the laser hardening process and to maintain tension in the cutting rule between stations 2 and 3 throughout the process. In the present embodiment, cutting rule 14 is in the form of a spring coil 16 , therefore, a means compatible for retaining spring coil 16 will be described. In the present embodiment, start/finish station 2 and takeup station 3 preferably contain a spindle 12 and drive motor 13 connected via a shaft or the like. Spindle 12 contains a means for winding and unwinding spring coil 16 such as slot 15 . Drive motors 13 are preferably common electrically driven motors. Drive motors 13 do not drive cutting rule 14 during the laser hardening process. Rather drive motors 13 maintain tension in cutting rule 14 between stations 2 and 3 during the laser hardening process by each applying an opposing rotational force to their respective spindles. Drive motors 13 are preferably controlled by a common programmable linear controller (PLC) 33 .
Cleaning station 4 provides a means for cleaning cutting rule 14 at the initial stages of the laser hardening process. Cleaning is sometimes necessary to remove dust and dirt particles that may cause defects in the hardened surface. In the present embodiment, cleaning station 4 preferably contains cleaning pads 17 connected to actuating device 18 . Cleaning pads 17 are preferably covered with a soft cloth material 19 , such as cheesecloth or the like. Actuating device 18 preferably actuates in a vise-like manner applying a clamping force between cleaning pads 17 .
Laser absorbent applying station 5 provides a means for applying a laser beam absorbent substance, such as a water-soluble ink or black oxide, to a selected surface area of cutting rule 14 . In the present embodiment, laser absorbent applying station 5 preferably contains an applicator 20 , such as a roll-on applicator, an ink reservoir 21 , and a means for supplying the ink from ink reservoir 21 to applicator 20 , such as tube 22 . Ink reservoir 21 preferably contains a water soluble ink 23 and is preferably pressurized.
Drying station 6 provides a means for drying the laser absorbent substance applied in station 5 . In the present embodiment, drying station 6 is preferably comprised of a series of air nozzles 24 . Air nozzles 24 supply compressed air 25 for drying of the ink applied in the laser absorbent applying station 5 .
Corrosion inhibitor applying station 7 provides a means for applying a corrosion inhibiting substance 27 , such as a rust preventative oil, to the surface of cutting rule 14 . In the present embodiment cleaning station 4 is reconfigured as corrosion inhibitor applying station 7 after the laser hardening process and before the stress relief process. In station 7 , cleaning pads 17 are removed and replaced by oil applying pads 26 . Pads 26 are soaked in a corrosion preventative oil such that when cutting rule 14 passes between pads 26 , the oil is wiped onto the surface of cutting rule 14 . Station 7 also preferably contains an oil drip system 37 for supplying additional oil to pads 26 during the process. Drip system 37 preferably contains a pressurized oil reservoir pressurized to cause oil to drip from an outlet in the reservoir onto pads 26 .
Central laser processing station 1 provides a means for laser heat treating and laser stress relieving cutting rule 14 . In the present embodiment, central laser processing station 1 preferably comprises a laser beam producing device 8 , a laser beam focusing device 9 , and drive motors 10 a and 10 b. Laser beam producing device 8 is preferably a 1,000 watt continuous wave CO 2 laser beam producing mechanism. As a substitute for a continuous wave CO 2 laser, a YAG laser may be used or any other type of laser that reaches a level of at least 500 watts continuous wave may be used. Use of a YAG laser eliminates the need for application of the water-soluble ink solution adding station, i.e. stations 5 and 6 . However, a YAG laser may create a safety hazard, requiring special equipment not necessary for the use of a continuous wave CO 2 laser. Central laser processing station 1 may also contain a means for supplying an assist gas for facilitating the laser heating process, such as assist gas nozzle 34 . Assist gas nozzle 34 may provide a gas such as nitrogen to the interface of the laser beam and the surface of the cutting rule being hardened in order to facilitate the hardening process.
Laser beam focusing device 9 preferably comprises an optical device 30 and an adjustable height optical device support 31 . It has been found that when optical device 30 is a plano/convex lens, optimum laser hardening results are achieved. Optical support 31 preferably contains a linear translation mechanism 29 that provides controlled vertical translation of optic 30 . Vertical translation of optic 30 provides a means for controlling the focal point of laser beam 28 which will be described in more detail below. Translation mechanism 29 is preferably a shaft having a sliding frictional lock collar or other similar arrangement. Translation mechanism 29 also preferably contains a means for measuring the translation, such as a micrometer. Translation mechanism 29 may also be a motorized translation device, such as a ball screw actuator, and may also be computer controlled.
Drive motors 10 a and 10 b provide rotational power to drive wheels 32 . Drive wheels 32 provide a frictional force for feeding cutting rule 14 through the laser hardening process stations. Drive wheels 32 are preferably made of a substance such as rubber. Drive motors 10 a and 10 b are preferably common electrically driven motors synchronously controlled by a common programmable linear controller 33 . Controller 33 provides a proper feed rate for performing both the heat treating and stress relief processes on cutting rule 14 .
Having obtained the processing stations setup according to the foregoing, a description will now be made of the laser hardening process for laser hardening a steel cutting rule. Prior to performing the laser hardening process, central laser processing station 1 is configured to obtain the desired laser hardening results, and the steel cutting rule is prepared and installed in the laser processing setup.
Referring now to FIGS. 3, 4 a, 4 b, and 5 a detailed description will be made of the laser beam settings and adjustment according to one aspect of the present invention.
As seen in FIG. 3, central laser processing station 1 comprises a laser beam producing device 8 and laser beam focusing device 9 . Laser beam producing device 8 is preferably a 1,000 watt continuous wave CO 2 laser that produces a D-mode laser beam 35 . Laser beam focusing device 9 comprises optic 30 and adjustable height optic support 31 . Optic 30 is preferably a 1½ inch diameter, 5 inch focal length plano/convex optic and is connected to optic support 31 . Optic support 31 preferably contains a linear translation mechanism 29 that provides a means for focusing laser beam 28 . In the present embodiment, translation mechanism 29 preferably contains a shaft and sliding collar having a frictional lock and a means for measuring the translation, such as a micrometer. Upon actuation of translation mechanism 29 , optic 30 translates vertically along a Z axis, thereby providing for adjustment of the focal point of laser beam 28 . The focal point reference origin O is preferably the cutting edge surface of cutting rule 14 . Utilizing cutting surface O as a reference, a focal distance F may be obtained.
The laser beam power setting and focal point are first established for the heat treating process. The power settings for the heat treating process of the present embodiment preferably comprise a laser beam power setting of between 500 to 550 watts. The 50 watt range is used as a variable for adjusting the hardened surface case depth. It should be noted that there is an almost limitless number of options available to obtain a desired hardness result. For example, the laser power setting and focal point may each be independently varied to obtain a desired hardened surface case depth. Additionally, the rate at which the workpart is fed through the laser beam may also be varied in order to obtain a desired result. Therefore, the laser power settings, focal point, and feed rates described herein have been found to produce the optimum results for the present invention. As seen in FIG. 4A, the laser beam focal point referenced from surface O is optimally 0.010 inch as designated by dimension F. For the heat treating process the laser beam dimensions L and W, as seen in FIGS. 4A and 5, are approximately 1¼ inch and 0.010 to 0.012 inch, respectively. The resultant beam has a substantially parabolic shape as denoted by P in FIG. 4 A.
After having obtained the laser hardening process configuration and laser beam adjustments according to the foregoing, a steel cutting rule raw material is prepared for the laser hardening process. As seen in FIGS. 6A and 6B, the steel cutting rule raw material commonly comes in a spring coil 16 form. The cutting rule raw material commonly has a rectangular cross-section, as seen in FIG. 6 B. The preferred dimensions of the steel cutting rule raw material according to the present embodiment are a thickness T of 0.021 to 0.042 inches and a height H of two inches or less. However, thicknesses up to 0.084 inch may also be used. The preferred material for the cutting rule according to the present embodiment is AISI 1050 spring steel. The preferred body hardness of the raw material is 33-35 R c and has a grain structure consisting mainly of tempered martensite with as much as 10-15% bianite. However, other material types and sizes may also be utilized. As seen in FIG. 6C, a beveled edge 36 is machined on one side of the steel cutting rule raw material. Beveled edge 36 may be machined by common methods such as grinding or forming. Having machined beveled edge 36 , steel cutting rule coil 16 is now ready for installation in the laser hardening process system.
As seen in FIG. 1, steel cutting rule coil 16 is installed in start/finish station 2 . Steel cutting rule coil 16 is installed on spindle 12 with free end 37 on the innermost portion of coil 16 installed in slot 15 on spindle 12 . The outermost free end 38 of spring coil 16 is fed through the various processing stations and into slot 15 of spindle 12 in intermediate takeup station 3 . The portion of steel cutting rule 14 initially fed through the processing stations is not subjected to the laser hardening process. Rather, it is excess material, known as lead, to be discarded after the laser hardening process.
Upon commencing the laser hardening process, steel cutting rule 14 is fed through the laser hardening process by drive motor boa with drive motor 10 b being idle. The speed of drive motor 10 a is controlled by programmable linear controller 33 and is preferably set to a feed rate of about 125 feet per minute. It has been found that a feed rate of 125 ft./min. coupled with the previously described laser beam settings of 500-550 watts with a 0.010 focal distance from origin O provide the optimum laser hardening results. However, as previously described, the feed rate may be varied according to a desired hardness result. Drive motors 13 in stations 2 and 3 are also controlled by controller 33 . Drive motors 13 apply opposing rotational forces to their respective spindles 12 to maintain tension in cutting rule 14 during the laser hardening process.
The first step of the laser hardening process is to clean the cutting rule in cleaning station 4 . In the present embodiment of the invention, steel cutting rule 14 passes between cleaning pads 17 in cleaning station 4 . Actuating device 18 supplies a clamping force between pads 17 sufficient to supply wiping of steel cutting rule 14 but not excessive such as to cause binding of steel cutting rule 14 . Steel cutting rule 14 is wiped clean by cloth 19 attached to cleaning pads 17 . Although described in terms of the present embodiment, alternate embodiments for cleaning station 4 may be used. For example, cutting rule 14 may be cleaned by air curtains or a spray nozzle which dispenses a cleaning solution rather than being wiped by cloth 19 . After passing through cleaning station 4 steel cutting rule 14 next passes through laser absorbent applying station 5 .
In laser absorbent applying station 5 , a laser beam absorbent substance such as a water-soluble ink or black oxide is applied to a selected surface area of steel cutting rule 14 . In the present embodiment of the invention, a water-soluble ink solution is applied to cutting edge O of steel cutting rule 14 . The ink solution is applied by an applicator 20 , such as a roll-on or drip applicator. Applicator 20 is connected to an ink reservoir 21 containing a water-soluble ink 23 . Ink reservoir 21 is preferably pressurized by an external pressure source, such as compressed air, to a pressure of approximately 5 psi (pounds per square inch). Pressurization of ink reservoir 21 is preferably sufficient to cause the water-soluble ink 23 to flow to applicator 20 at a desired rate in order to effect optimum application of the water-soluble ink solution 23 to the selected surface of cutting rule 14 . Pressurization of ink reservoir 21 is preferably controlled by programmable linear controller 33 . As steel cutting rule 14 passes through applying station 5 , water-soluble ink solution 23 is applied by applicator 20 to the selected surface area of steel cutting rule 14 to be hardened. Although described in terms of the present embodiment, alternate laser absorbent materials and application methods may also be used. For example, a black oxide or phosphate coating may be applied rather than ink. Additionally, the laser absorbent material may be applied by an alternate applying means such as a spray nozzle. After application of the water-soluble ink solution, steel cutting rule 14 next passes through drying station 6 .
Drying station 6 contains a means for drying the laser absorbent substance applied in station 5 . In the present embodiment of the invention, drying station 6 preferably contains a series of air curtains 25 . Air curtains 25 preferably comprise compressed air supplied by a series of air nozzles 24 . The air pressure supplied to nozzles 24 is preferably regulated to approximately 80 psi and is preferably controlled by programmable linear controller 33 . The air pressure supplied by nozzles 24 is preferably sufficient to dry water-soluble ink solution 23 but insufficient to cause removal of the ink solution from the surface. Alternate methods of drying the laser absorbent substance may also be employed. For example, a heat source may be applied to the laser absorbent substance in order to dry it. After passing through drying station 6 , steel cutting rule 14 next passes through central laser processing station 1 .
Having obtained the laser power settings of 500-550 watts and focal point of 0.010 inch from cutting edge surface O according to the foregoing description, steel cutting rule 14 is heat treated by passing steel cutting rule 14 beneath laser beam 28 . The laser beam intensity at the cutting rule surface is sufficient to cause a shallow depth of the cutting rule surface to be heated above the transformation temperature, thereby changing the phase of the steel to austenite. After passing through laser beam 28 and being transformed to austenite, the shallow surface area is rapidly cooled by self-quenching, thereby transforming the steel phase to martensite. The resulting martensite layer formed by the laser heat treating process preferably has a hardness of at least 60 R c and a case depth of about 0.004 to 0.006 inches. A shallow depth of 0.004 to 0.006 inch has been found to provide optimum surface hardness and ductility properties. However, case depths between 0.001 to 0.010 may be obtained by varying the laser power settings, focal point and feed rate. The hardened surface provides increased wear resistance, thereby increasing the longevity of cutting rule 14 and reducing the cost of requiring frequent replacement of the cutting rule. Furthermore, the hardened surface depth is shallow enough that the cutting rule maintains its ductility properties, thereby allowing the cutting rule to be bent or formed into a number of shapes after being laser hardened.
FIG. 9A is a photograph of a cross-section of a steel cutting rule prior to being subjected to the foregoing laser heat treatment process. FIG. 9B is a photograph of a cross-section of a steel cutting rule after being subjected to the foregoing laser heat treatment process. As seen in FIG. 9B, the tip of the cutting rule has been heated and contains a grain microstructure that has an appearance of untempered martensite. The heat treated surface area is depicted by the white area in the tip of the cutting rule. It should be noted that the laser heat treatment process of the present invention results in a uniform grain structure throughout the heat treated tip area. In contrast, FIG. 11 is a photograph of a cross section of a common induction hardened steel cutting rule having a non-uniform heat treated tip. As seen in FIG. 11, a grayish area in the middle of the heat treated tip has not been heat treated, thereby resulting in a non-uniform heat treatment process. This results in a lower surface hardness than that achieved by the foregoing laser heat treatment process.
The hard untempered martensitic layer formed by the foregoing laser heat treatment process contains internal stresses that make the hardened surface brittle. In order to remove the internal stresses, a stress relief process must be performed. The stress relief process for the present invention is described in more detail below. The next processing station after cutting rule 14 passes through laser processing station 1 for the heat treatment process in intermediate takeup station 3 .
In the present embodiment of the invention, intermediate takeup station 3 winds steel cutting rule 14 back into the form of a spring coil. This is accomplished by drive motor 13 in station 3 applying a rotational force to spindle 12 , thereby causing steel cutting rule 14 to wrap around spindle 12 forming coil 16 . Although described in terms of a coil winder, takeup station 3 may provide for an alternate method to takeup the steel cutting rule after the laser hardening process has been accomplished. After all of the steel cutting rule has passed from station 2 to station 3 , the process is reversed to perform stress relief of the laser hardened surface.
In the present embodiment of the invention, prior to performing the stress relief, central laser processing station 1 is reconfigured to perform the stress relief and cleaning station 4 is reconfigured into corrosion inhibitor applying station 7 .
Central laser processing station 1 is reconfigured by adjusting the laser beam power setting and by adjusting the focal point of the laser beam. The laser beam power setting for performing the stress relief is preferably set to about 80 watts below the power setting for the heat treating process. For example, a power setting of 500 watts for heat treating would require a power setting of about 420 watts for stress relief. The focal point of the laser beam is adjusted by adjusting translation mechanism 29 , thereby adjusting the distance of optic 30 from the laser hardened surface O. The focal point of laser beam 28 for the stress relief process is preferably set to 0.170 inch from cutting surface O, thereby defining dimension F, as seen in FIG. 4 A. It has been found that the 80 watt power setting differential coupled with the 0.170 inch focal distance from cutting edge O provides for the optimum stress relief results. However, as previously discussed, the power settings, focal point and feed rate may be varied as desired to achieve a desired result.
Cleaning station 4 is reconfigured into corrosion inhibitor applying station 7 by removing cleaning pads 17 and installing corrosion inhibitor applying pads 26 in place of cleaning pads 17 . Corrosion inhibitor applying pads 26 are preferably soaked in a corrosion preventive oil prior to installation onto actuating device 18 . Corrosion inhibitor applying station 7 also preferably contains a reservoir 39 of corrosion preventive oil and a means for supplying the oil from the reservoir 39 to applying pads 26 . Reservoir 39 is also preferably pressurized similar to reservoir 21 in applying station 5 and the pressurization is preferably controlled by programmable linear controller 33 . The pressurization is preferably controlled to provide a predetermined continuous drip rate of the corrosion preventive oil from reservoir 39 to oil applying pads 26 . Supplying a continuous drip of oil from reservoir 39 to pads 26 ensures that pads 26 remain soaked with the oil and thereby ensuring the oil is applied to cutting rule 14 .
After having reconfigured stations 1 and 7 , cutting rule 14 is prepared for the stress relief process. Free end 37 of cutting rule 14 , now contained on intermediate takeup station 3 , is fed through the processing stations and back onto spindle 12 in start/finish station 2 . Free end 37 is installed in slot 15 of spindle 12 such that upon application of a rotational force by drive motor 13 to spindle 12 , cutting rule 14 is wound back into the form of a coil 16 .
Upon commencement of the stress relief process, steel cutting rule 14 is fed through the processing stations by drive motor 10 b while drive motor 10 a remains idle. Drive motor 10 b is preferably controlled by programmable linear controller 33 and is set to provide a feed rate of about 155 feet per minute. It has been found that a feed rate of 155 ft./min. coupled with the laser settings of 80 watts below the heat treating power setting and a 0.170 focal distance, provide optimum stress relief results. However, as mentioned, these variables may be adjusted in order to achieve a desired result.
During the stress relief process steel cutting rule 14 first passes through central laser processing station 1 . The selected surface area of steel cutting rule 14 which was previously hardened during the heat treating step is now subjected to laser beam 28 a second time to perform stress relief. Laser beam 28 's intensity is set such that only stress relief is performed while retaining the previously hardened untempered martensite microstructure. One objective of the present invention is to relieve the internal stresses in the untempered martensite layer formed in the heat treating step without substantially reducing the hardness of the untempered martensite.
Typically, the stress relief process relieves internal stresses by releasing some of the carbon particles trapped in the microstructure when the untempered martensite was formed. The release of these carbon particles from the microstructure reduces the hardness of the untempered martensite and also changes its microstructure appearance to tempered martensite. However, in the present invention, the laser beam power setting and focal point are established such that the internal stresses are relieved but the microstructure retains its appearance as untempered martensite.
FIG. 10 is a photograph of a cross-section of a steel cutting rule after being subjected to the foregoing stress relief process. As seen in FIG. 10, the previously heat treated tip of the cutting rule retains its appearance as untempered martensite. However, since the internal stresses have been relieved, the brittleness has been removed. The resultant steel cutting rule has a surface hardness of at least 60 R c , about 5 R c higher than conventional cutting rules, but has equivalent ductility properties since the brittleness has been removed. After being stress relieved in central laser processing station 1 , steel cutting rule 14 moves on to corrosion inhibitor applying station 7 .
Upon entering corrosion inhibitor applying station 7 , steel cutting rule 14 passes between corrosion inhibitor applying pads 26 . Pads 26 are preferably soaked in a corrosion preventive oil. Actuating device 18 applies a clamping force between pads 26 , such that as cutting rule 14 passes between pads 26 , corrosion preventive oil is wiped onto the surface of cutting rule 14 . As the stress relief process proceeds, reservoir 39 is pressurized by an external pressure source preferably to about 5 psi. The pressure is sufficient to provide a continuous drip of oil contained within the reservoir to be applied to pads 26 , thereby maintaining saturation of pads 26 . Although the present embodiment employs a wipe-on method of applying corrosion preventive oil, alternate methods such as a spray or immersion bath application may also be employed.
Upon completion of the stress relief process, steel cutting rule 14 is wound into the form of a spring coil 16 and is retained in start/finish station 2 . spring coil 16 is then removed from station 2 and is now ready for use in its final form.
In another aspect of the invention the foregoing laser hardening process is utilized in laser hardening a metal workpart. The metal workpart is not limited to the form of a steel cutting rule but may be in any form such as a shaft or a flat plate. As seen in FIG. 7, the metal workpart is surface-hardened by being processed through central laser processing station 101 . Central laser processing station 101 may be similar to central laser processing station 1 according to the foregoing description. Central laser processing station 101 performs both a laser heat treat process and a stress relief process similar to the foregoing description. The laser beam configuration, such as the power settings and focal point, are adjusted according to the foregoing description in order to perform both the laser heat treatment and the stress relief process on the metal workpart. The metal workpart may be passed through central laser processing station 101 by means such as a conveyor belt or other similar means or central laser processing station 101 may be traversed across a stationary metal workpart. The metal workpart is first heat treated by being subjected to the laser beam, thereby forming a hard surface layer having an appearance of untempered martensite. The metal workpart is then stress relieved by being subjected to the laser beam a second time similar to the foregoing description. After the stress relief process, the metal workpart microstructure retains its appearance as untempered martensite. However, internal stresses have been relieved, thereby removing brittleness.
The metal workpart may also be subjected to additional processing steps, such as cleaning station 104 , laser beam absorbent applying station 105 , laser beam absorbent drying station 106 and corrosion inhibitor applying station 107 , as seen in FIG. 8 . Stations 104 through 107 as seen in FIG. 8 are similar to stations 4 through 7 according to the foregoing description. Accordingly, the metal workpart may be cleaned by methods such as a dry cloth wipe, spray on cleaning solution or being subjected to an air curtain. Also, a laser beam absorbent substance may be applied to the surface area of the metal workpart depending on the type of laser beam used in the laser hardening process. The laser beam absorbent substance may be applied by various methods, such as roll on or spray on application. Additionally, the laser beam absorbent substance may require drying, such as being subjected to a series of air curtains or a heat source. Further, a corrosion inhibiting substance such as oil may be applied to the surface of the metal workpart after being subjected to the stress relief process.
Although the present invention has been illustrated with reference to certain preferred embodiments, it will be appreciated that the present invention is not limited to the specifics set forth therein. Those skilled in the art readily will appreciate numerous variations and modifications within the spirit and scope of the present invention, and all such variations and modifications are intended to be covered by the present invention, which is defined by the following claims. | The invention relates to surface hardening of steel workpieces using laser beams and more particularly to laser hardening steel cutting rules. The method comprises applying a first laser beam of a first intensity and focused to a first focal point to a selected surface area of the metal workpart and subsequently applying a second laser beam having a second intensity and focused to a second focal point to the selected surface area. Application of the first laser beam heat treats the selected surface area to a predetermined depth, thereby increasing the surface hardness. Application of the second laser beam relieves internal stresses produced by the heat treating while retaining the increased hardness. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
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BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to the field of computer speech navigation and more particularly to a method and apparatus for speech enabling labeless controls in an existing graphical user interface.
2. Description of the Related Art
Speech recognition, also referred to as speech-to-text, is technology that enables a computer to transcribe spoken words into computer recognized text equivalents. Speech recognition is the process of converting an acoustic signal, captured by a transducive element, such as a microphone or a telephone, to a set of words. Subsequently, these words can be used for speech navigation and speech dictation. Though the use of speech recognition for speech dictation has flourished, the transparent application of speech navigation to a graphical user interface for speech command and control lags behind.
Originally, speech application developers accomplished speech navigation by associating a discrete number of commands available in a graphical user interface with command and control macros. In turn, speech application developers assigned to each command and control macro a corresponding speech command. Thus, a speech navigation system user's utterance invoked a particular command and control macro associated with a command in the graphical user interface. Still, the command specific nature of the speech user interface inhibited its generic application to customized graphical user interfaces. Notably a graphical user interface could include interface objects capable of performing at least one action, for example a button or a list box. Unless the speech developer was aware of each control in a graphical user interface, those controls unknown to the speech developer remained separate from the speech navigation system. Hence, past speech navigation systems lacked portability.
Recently, speech recognition systems have integrated speech navigation, at least as applied to standard graphical user interface controls. Using an accessibility interface, for instance Microsoft® Active Accessibility®, speech developers can provide a more seamless interface between the speech navigation system and the graphical user interface. By way of example, Active Accessibility® can supply a speech navigation system with a wide variety of information concerning controls such as toolbars, buttons and menus in a program's graphical user interface. Using an accessibility interface, speech developers can dynamically assign speech commands to individual controls according to information provided to the speech navigation system by the accessibility interface. In consequence, when a user invokes a window containing a set of controls, the speech navigation system, using the accessibility interface, can query the window for its contents identifying each control. Subsequently, the speech navigation system can assign corresponding standard speech commands according to the identity of each control.
Still, present speech navigation systems cannot properly supply an appropriate speech command for labeless controls not recognized by an accessibility interface. Specifically, present speech navigation systems cannot properly supply an appropriate speech command for controls not having an inherent label. As a result, in a window containing labeless controls in addition to standard controls, the accessibility interface can report only the identity of the standard controls. The speech navigation system will remain ineffective as to each labeless control. Thus, present systems do not provide a complete integration between the speech navigation system and the graphical user interface.
SUMMARY OF THE INVENTION
A system for extending the range of speech commands to labeless controls in an existing graphical user interface in accordance with the inventive arrangement satisfies the long-felt need of the prior art by providing a complete integration between the speech navigation system and the graphical user interface. Thus, the inventive arrangements provide a method and system for speech enabling labeless controls in an existing graphical user interface. The inventive arrangements have advantages over all known speech enabling methods used to speech enable graphical user interface controls, and provides a novel and nonobvious system, including apparatus and method, for speech enabling labeless controls in an existing graphical user interface.
A method for speech enabling labeless controls in an existing graphical user interface can comprise the steps of: identifying controls in a window contained in the graphical user interface; testing each identified control for an associated label; for each identified control having an associated label, adding the associated label to an active grammar of a speech recognition system; for each identified control not having an associated label, creating a label based upon object properties of contextual relevant user interface objects, for instance those object positioned proximate to the identified control; and, further adding each created label to the active grammar. In testing each identified control for an associated label, an accessibility interface query can be applied to each identified control in the window. In addition, in creating the label, each contextually relevant object can be searched for an object property descriptive of the identified control not having an associated label. Subsequently, a label can be formed based upon the descriptive object property found in the searching step.
A method for speech enabling labeless controls in an existing graphical user interface can further comprise the steps of: for each identified control not having a created label based upon an object property of contextually relevant object found in the searching step, determining whether the identified control has a default action; assigning a generic label to the identified control having a default action; associating the determined default action with the assigned label; and, adding the assigned label corresponding to the default action to the active grammar. Additionally, for each identified control having multiple actions with no clear default action, the method can further include the steps of forming a help panel with information about speech commands accessible for that identified control; and, assigning the help panel as the default action.
BRIEF DESCRIPTION OF THE DRAWINGS
There are presently shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a pictorial representation of a computer system with audio capabilities on which the method of the invention can be used.
FIG. 2 is a block diagram showing a typical high level architecture for the computer system in FIG. 1 .
FIGS. 3A-3C, taken together, are a flow chart illustrating the inventive method.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a typical computer system 1 for use in conjunction with the present invention. The system preferably comprises a computer 3 including a central processing unit (CPU), fixed disk 8 A, and internal memory device 8 B. The system also includes a microphone 7 operatively connected to the computer system through suitable interface circuitry or “sound board” (not shown), a keyboard 5 , and at least one user interface display unit 2 such as a video data terminal (VDT) operatively connected thereto. The CPU can comprise any suitable microprocessor or other electronic processing unit, as is well known to those skilled in the art. An example of such a CPU would include the Pentium or Pentium II brand microprocessor available from Intel Corporation, or any similar microprocessor. Speakers 4 , as well as an interface device, such as mouse 6 , can also be provided with the system, but are not necessary for operation of the invention as described herein. The various hardware requirements for the computer system as described herein can generally be satisfied by any one of many commercially available high speed multimedia personal computers offered by manufacturers such as International Business Machines (IBM), Compaq, Hewlett Packard, or Apple Computers.
FIG. 2 illustrates a presently preferred architecture for a speech navigation system in computer 1 . As shown in FIG. 2, the system can include an operating system 9 , a speech navigation system 10 in accordance with the inventive arrangements, and a graphical user interface 11 . A speech enabled application 12 can also be provided. In FIG. 2, the speech navigation system 10 , the graphical user interface 11 , and the speech enabled application 12 are shown as separate application programs. It should be noted, however, that the invention is not limited in this regard, and these various applications could, of course, be implemented as a single, more complex applications program.
As shown in FIG. 2, computer system 1 includes one or more computer memory devices 8 , preferably an electronic random access memory 8 B and a bulk data storage medium, such as a fixed disk drive 8 A. In a presently preferred embodiment described herein, operating system 9 is one of the Windows family of operating systems, such as Windows NT, Windows 95 or Windows 98 which are available from Microsoft Corporation of Redmond, Wash. However, the system is not limited in this regard, and the invention can also be used with any other type of computer operating system. The system as disclosed herein can be implemented by a programmer, using commercially available development tools for the operating systems described above.
In the present invention, audio signals representative of sound received in microphone 7 are processed within computer 1 using conventional computer audio circuitry so as to be made available to operating system 9 in digitized form. The audio signals received by the computer 1 are conventionally provided to the speech navigation system 10 via the computer operating system 9 in order to perform speech recognition functions. As in conventional speech recognition systems, the audio signals are processed by the speech navigation system 10 to identify speech commands spoken by a user into microphone 7 . Recognized speech commands subsequently can be converted to corresponding system commands in the graphical user interface 11 associated with the speech enabled application 12 .
FIGS. 3A-3C, taken together, are a flow chart illustrating a process for speech enabling labeless controls in an existing graphical user interface. In FIG. 3A, the method in accordance with the inventive arrangements begins in block 20 upon a window becoming the exclusive active window in the foreground of the graphical user interface 12 , commonly referred to as obtaining focus. Following path 21 to decision block 22 , the process continues only if unidentified objects remain in the active window. Continuing along path 23 to block 24 , the next unidentified object in the window is identified and, in block 26 , tested to determine if the object is a control suitable for speech navigation. If the object is determined not to be a control, returning along paths 39 and 33 to decision block 22 , the process can repeat, if necessary.
If, in block 26 , the object is determined to be a control, following path 27 to decision block 86 , it is further determined whether the control has multiple actions and no clear default action. If the control is determined to have a single action, or a clear default action in decision block 86 , the method continues along path 87 to decision block 28 . Alternatively, if the control has multiple actions and no clear default action, following path 79 to block 80 , a help panel can be formed to include information pertaining to the standard speech commands available for use with the particular class of controls corresponding to the subject control. For instance, the help panel for a list-box type control could include “Scroll Up”, “Scroll-Down”, or “Enter-Key”. Moreover, following path 81 to block 82 , the newly formed help panel can be assigned to the subject control. Finally, the presentation of the help panel is assigned to the control as the default action in block 84 . In this way, the user can be informed of possible speech commands consistent with the subject control.
Continuing along path 85 to decision block 28 , the control can be queried for a corresponding label. Specifically, each control can be queried through the use of an accessibility interface provided by Microsoft® Active Accessibility®. Active Accessibility® is based on the Component Object Model (COM), the Microsoft®-developed industry standard that defines a common way for applications and operating systems to communicate. In an Active Accessibility® application, sometimes referred to as a server, the server can provide information about the contents of the computer screen that is within the server's control. Accessibility aids, referred to as clients, use Active Accessibility® to obtain information about the user interface of other applications and the operating system. With Active Accessibility®, user interface elements are exposed to clients as COM objects. These accessible objects maintain pieces of information, called properties, which describe the object's name, screen location, and other information needed by accessibility aids. Accessible objects also provide methods, which are functions that clients can call to cause the object to perform some action. Accessible objects are implemented using Active Accessibility®'s COM-based IAccessible interface. This interface includes functions such as IAccessible::get_accName and IAccessible::accLocation, which allow clients to examine an object's properties. The interface also provides methods such as IAccessible::accDoDefaultAction and IAccessible::accHitTest, which clients can call to cause the object to perform some action. Clients obtain information about or interact with an object by calling the IAccessible properties and methods.
Thus, in decision block 28 , a control identified in decision block 26 can be queried for a corresponding label using IAccessible::get_accName. If the Active Accessibility® interface returns a label, following path 31 to block 30 , the label can be added to the active grammar of the speech navigation system. Returning along path 33 to decision block 22 , the next object can be tested unless no more unidentified objects remain in the active window. Accordingly, following path 37 to block 32 , the process terminates.
In contrast, if in decision block 28 the Active Accessibility® interface fails to return a label, following path 29 to jump circle B, contextually relevant user interface objects, for instance objects proximate to the labeless control, can be examined for object properties pertinent to the identity of the labeless control. Specifically, in FIG. 3B, following path 41 from jump circle B to decision block 40 , the process can continue so long as unidentified contextually relevant objects remain. If unidentified contextually relevant objects remain to be inspected, the process continues along path 45 to block 42 in which the object properties of each contextually relevant object are inspected for a potential label. Following path 47 to decision block 44 , the next contextually relevant object can be examined if the process fails to uncover a descriptive object property in the present contextually relevant object.
If, however, a descriptive property is found in a contextually relevent object in decision block 44 , continuing along path 49 to block 46 , a label can be created using the uncovered descriptive object property. Subsequently, following path 51 to block 48 , the created label can be added to the active grammar of the speech navigation system before returning along path 53 to jump circle A to decision block 22 in FIG. 3A, whereupon the next window object can be identified and labeled, if necessary. But, if all contextually relevant objects have been identified in decision block 40 , yet none provide a descriptive object property useful in the creation of a label for the control, then following path 43 to jump circle C, a default method can provide an appropriate mechanism suitable for speech navigation which can be associated with the subject labeless control as a label substitute.
FIG. 3C illustrates the default method for providing a substitute label for unhandled labeless controls. From jump circle C, leading to block 68 along path 61 , a speech command can be associated with the labeless control corresponding to the labeless control's default action. Following path 67 to block 64 , a numeric label can be assigned to the labeless control as a label. Finally, following path 71 to block 66 , the assigned label is added to the active grammar. Subsequently, the process can return along path 73 to jump circle A to decision block 22 in FIG. 3A, whereupon the next window object can be identified and labeled, if necessary.
Having assigned a label or label substitute to each control and labeless control in the active window, the speech navigation system 10 in coordination with graphical user interface 12 can display each label in or near the controls to which they apply. If labeling obstructs the view of objects in the active window, a symbol, for instance a transparent image of a speech bubble with a line therethrough, or a small red dot, can be positioned proximate to the control. The symbol can indicate to the user that the user must take an affirmative action to display the controls. The affirmative action can be a click of mouse 6 , or a tap of a key in keyboard 5 . Furthermore, the affirmative action could be the speech command, “Show Me What To Say.” Upon receiving the affirmative command, the labels can be displayed until the user either issues a speech command affecting a control in the active window, issues a speech command to hide the labels, or until a reasonable timeout period, for instance one minute, elapses. As an alternative, each label can be drawn transparently over the label's corresponding control so as to not obscure important graphical information.
When the speech navigation system 10 receives a speech command corresponding to a label associated with a control in the active window, the speech navigation system 10 can execute the single function associated with that control. In contrast, where the control associated with the invoked label is more complex and can respond to several speech commands, the help panel containing information about each speech command pertaining to a control aspect of the object can be displayed. In any event, however, each control contained in the active window, including labeless controls, can be manipulated by the speech navigation system 10 . Hence, the present inventive method provides a complete integration between the speech navigation system 10 and the graphical user interface 12 . | A method for speech enabling labeless controls in an existing graphical user interface can comprise the steps of: identifying controls in a window contained in the graphical user interface; testing each identified control for an associated label; for each identified control having an associated label, adding the associated label to an active grammar of a speech recognition system; for each identified control not having an associated label, creating a label based upon an object property of a contextually relevant user interface object; and, further adding each created label to the active grammar. In testing each identified control for an associated label, an accessibility interface query can be applied to each identified control in the window. In addition, in creating the label, each contextually relevant object can be searched for an object property descriptive of the identified control not having an associated label. Subsequently, a label can be formed based upon the descriptive object property found in the searching step. | 6 |
BACKGROUND OF THE INVENTION
The invention relates to a device for detecting objects lying in the earth, especially explosive objects, such as non-exploded mines, grenades, munitions or bombs, with a mobile device on which a jib swivellable at least about a vertical axis is mounted, on the free end of which several measuring heads are arranged.
Former military sites often have explosive objects in the earth which must be removed from the earth before the terrain can be directed toward a new use. Since it is usually a question of very large areas, it would be too expensive to remove all the earth in the upper soil layers and search for the objects mentioned.
In order to be able to implement cleanups of old military encumbrances with a reasonable expenditure, it is first of all necessary to detect not yet exploded objects and to remove only the earth at the find sites and cleanse it of explosive objects in a second step. Since large surface segments of land must be combed, conventional detection devices are not practicable for this and are associated with great dangers for life and limb of the personnel.
With known manual searching apparatus which are guided by operators over the ground, only relatively narrowly restricted areas can be searched with a reasonable expenditure of time. Moreover, the danger for operating personnel is very great, because the person must walk over the grounds to be searched with the metal detector and can cause the objects detected to detonate through inattention under certain circumstances.
Moreover, vehicles are known on the front side of which metal detectors are firmly installed, so that only the area in front of the vehicle can be searched for explosive objects. Even with these vehicles, the surface yield is not sufficient. A further disadvantage consists in that, as a rule, only flat ground can be examined because the measuring heads are rigidly fastened on the vehicle. Uneven terrain therefore leads to considerable errors in identifying the location of the objects, which has as a consequence that the cleanup troops are either exposed to a heightened risk or must carry off more ground than is necessary in order to discover the objects, or that on account of the cants in troughs dead areas arise, so that many explosive objects are not located at all.
U.S. Pat. No. 4,021,725 describes a mine detecting apparatus which has a jib on the front side of a mobile device on whose free end a detection device is arranged. The jib is swivellable around a vertical and/or horizontal axis. The detection device possesses several probes in order be able to construct the position of magnetic dipoles and a map with the position of these discovered objects. During the forward movement, the jib executes an oscillating swinging movement. Owing to the fact that the probes are arranged in a row transverse to the direction of travel, the terrain is only probed along a line. Further, the mine detecting apparatus is usable only for level terrains. As soon as uneven terrains emerge, recognition of the position is erroneous, or mines located in the soil are not identified at all.
DE 42 27 461 A1 describes a mine reconnaissance and detector system which has a remote-controlled vehicle which is connected with a processing and control unit through an interconnecting cable. The sensor device is installed firmly on the mobile device, so that with uneven terrain erroneous measurements likewise occur. The marking device is located at the back end of this vehicle with the disadvantage that the exact position of discovered objects cannot be marked.
DE 35 26 492 A1 describes an apparatus for discovering metal, particularly mines. The metal seeking probe has a spool, whose diameter is greater than half the width of the vehicle, on which the probe is fastened by means of a carrier device. The carrier device is displaceable only in a vertical direction.
FR51551 describes a mobile mine searching device with a jib which is swivellable in a vertical direction about a horizontal axis, on which jib is suspended a net-shaped arrangement with measuring heads.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to make available an apparatus for detecting objects located in the ground which, independently of topography, soil structure and state of the terrain, makes possible high surface yields with great exactitude with reference to identification of the position of the objects to be detected, and without endangering the operators.
This object is accomplished with a device in which the jib is constructed in at least two parts from a rear jib and a front jib, wherein the front and the rear jibs are swivellable in a vertical direction independently of each other, the measurement heads for sweeping over strip-shaped surface areas of the terrain to be examined are arranged alongside one another, and in which at least one ground marking device for distinguishing the find sites found by the measurement heads is allocated to the measurement heads at the free end of the jib. The at least two part construction of the jib has the advantage that the measurement heads can always be held at the predetermined distance from the ground, so that uneven soil formations can also be covered. Advantageous embodiments are objects of the dependent claims.
In order to prepare the terrain to be examined for use of the device of the invention, it is only necessary first of all to lay out travel paths, for example with a remote controlled grenade mill. This way, objects situated in the surface area, for example, grenades, munitions, bombs or mines, are removed or detonated, so that in the area of the travel paths, the vehicle of the invention can be moved without danger. In the event that further explosive material is found lying still deeper in the travel path area, this is not dangerous for the apparatus to such extent, because the mobile device preferably involves a vehicle with low surface pressure, or the ground located in front of the vehicle can be searched before driving over it and, if necessary, cleared.
In accordance with a preferred embodiment, the mobile device is a tracked vehicle in which the weight of the overall device is distributed over a large contact area. Further advantages of a tracked vehicle are the high tractive capacity, good maneuverability, good ability to climb and great stability, so that even difficult terrain formations can be searched.
The vehicle is moved forward on the travel path and, in accordance with one possible operating method, stopped at certain predetermined intervals. With the jib arc-shaped surface areas are subsequently swept, the width of which depends on the type and number of the measurement heads arranged alongside one another on the free end of the jib. In accordance with another possible mode of operation, the jib is swung into a predetermined position, and path-shaped surface areas parallel to the travel path can be searched by continuous forward movement of the mobile device.
The jib can either be arranged on the chassis of the vehicle or on a frame enclosing the test room cabin. In the test room cabin the evaluation instruments of the measurement head signals and the operating personnel are housed. Preferably, installations for the overriding control of the mobile device are also accommodated in the test room cabin, so that the navigator can assume command over the vehicle in danger situations which the driver does not recognize.
Preferably, the measurement heads are based on the principle of magnetic navigation, so that appropriate measured curves of the ground examined can be generated. If a measured curve belonging to a measurement head shows a deflection, the jib is moved back and forth over the find site for exact localization. Afterward, the jib is held in this position and the find site marked. The ground marking device provided for this includes a stake marking device which is preferably equipped with stakes of nonmagnetic material.
At the find site located, one of the stakes is inserted into the ground for rough marking. So that the stakes are visible from a distance, they are preferably provided with a luminous paint. Variously configured stakes can be used according to soil characteristics. For hard soils, a hardened stake tip is of advantage. If the stakes for any reason cannot be inserted into the ground, the stakes can be constructed as self-uprighting marking buoys. Preferably, they possess a shaft with a round, for example hemispherical, foot element, wherein the materials for the shaft and the foot element are so coordinated that the center of gravity of the stake is located in the foot element. Since location over bodies of water is also anticipated, find sites must also be marked in the water. For this, floating stakes are used.
In order to be able to mark several find sites, the stake marking device preferably has at least one rotatable mounting star or a rotatable mounting drum which is outfitted with the stakes and in a preferred configuration is drivable by a tension belt, or especially a rubber tension belt. The stake marking device is preferably constructed as self-recharging. Stops are provided so that unstressing the tension belt is possible only when the mounting star or drum is empty.
In addition to or instead of the stake marking device, the ground marking device can have a paint marking device by means of which a paint marking is sprayed on the ground. As the paint marking device is preferably arranged next to each measurement head, a fine marking of the find site is thereby possible. The paint spraying device preferably has a valve and a spraying nozzle which is connected to a paint pressure conduit.
Between the front and the rear jib, an intermediate jib can be arranged which is telescopable by means of a linear drive device, so that in addition the distance between the measurement heads and the vehicle can also be changed. By a suitable soil distance measuring device on the free end of the jib, the movement of the jib can be controlled completely automatically, so that the predetermined distance of the measurement heads to the soil is always maintained. In this way, measurement exactitude is additionally improved.
In order not to influence negatively the detection of predominantly metallic objects, at least the front jib is manufactured from non-magnetizable material, preferably plastic. Even the component parts of the ground marking device must therefore not consist of magnetic material. This specification makes it necessary to operate the stake marking device and the paint marking device, for example, with compressed gas, especially compressed air, since electrical devices such as motors or the like can influence the measurement signals.
The stake marking device is connected to an intermediate container through a first gas conduit, which is connected with a compressor device through a second gas conduit, wherein the cross section of the second gas conduit is smaller than the cross section of the first gas conduit, and wherein a switchable valve is arranged after the intermediate container in the first gas conduit. By having the intermediate container remote from the stake marking device, for example being arranged at the front end of the rear jib, an electrically switchable valve can be used thereby disturbing the measurement heads.
The measuring heads are preferably hung freely swinging, so that a perpendicular measurement direction is always maintained. Especially on uneven terrain, measurement exactitude with respect to position recognition is distinctly improved this way. For this, the test heads are preferably attached to the jib or a special probe holder through a parallelogram suspension.
For special uses, for example for examining extremely steep slopes, it can be of advantage if the measuring heads are rigidly attached to the front jib or to the probe holder. It is thereby possible to align the probes perpendicular to the slope surface. Preferably, the measuring heads are hereby fastened to the jib or probe holder with cords or vibration damping swinging bars or by pliable elements, such as elastic tubes or rods. If during the movement of the jib the measuring heads should strike an obstacle, the elastic suspension yields despite the rigid arrangement, so that the measuring heads are not damaged.
Since the spraying nozzle is advantageously arranged adjacent to the respective measuring head, an appropriate suspension like that of the measuring heads is provided. The end of the paint pressure conduit provided with the valve and the spraying nozzle can therefore likewise be suspended swinging freely on the front jib or on the probe holder.
In accordance with a further embodiment, the probe holder can be rotated about a vertical and/or horizontal axis. In this way it is possible to change the width of the strip-shaped surface area to be examined.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments are explained in greater detail below on the basis of drawings.
FIG. 1 shows a perspective representation of a device of the invention in the terrain to be examined,
FIGS. 2, 3 and 4 show the device in side view in various uses,
FIG. 5 shows the device in side view in accordance with a further embodiment,
FIG. 6 shows the device in side view in accordance with a further embodiment,
FIGS. 7 and 8 show the device in plan view,
FIG. 9 shows the device in side view in accordance with a further embodiment,
FIG. 10 shows the stake marking device in front view,
FIG. 11 shows the stake marking device illustrated in FIG. 10 in side view and partially in section,
FIG. 12 shows the stake marking device in accordance with a further embodiment in side view and partial section,
FIG. 13 shows the stake marking device illustrated in FIG. 12 in plan view, and
FIG. 14 shows the stake as marker buoy for a solid upper surface.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, the device for detecting objects 6 located in the ground is represented in perspective on a terrain to be investigated, in which first of all a travel path 1 has been produced by means of a suitable munitions clearing device. If a large terrain is to be searched, several travel paths 1 are laid down parallel to one another, whose distance can amount to 20 to 30 m. The mobile device 10, which is represented as a tracked vehicle in the embodiment depicted here, moves in this travel path 1. Behind the driver's cab 12 of the mobile device 10, there is situated a personnel and testing room cabin 13 which is enclosed by a frame 14 on which a jib 20, positioned over the roof, is mounted, the jib having an arrangement of several measuring heads 40 on its free end.
The dimensions of the vehicle 10, and here especially the tracks 11, are laid out such that despite the great overall weight of the device only a small surface pressure is exerted on the ground of the travel path 1. This is necessary so that explosive objects, which are situated in deeper lying layers of the ground of the travel path 1 and which were not yet found by the travel path clearing vehicle, cannot be caused to explode. Furthermore, the vehicle 10 is suitable for roads and fording. The speed of the vehicle 10 is steplessly regulable.
The jib 20 is constructed in two parts from a rear jib 21 and a front jib 23, wherein the rear jib 21 is attached on a swivelling platform 24. The jib 20 is moved back and forth around a vertical axis by means of the swivelling device 26 mounted in the swivelling platform 24, so that the measuring heads 40 sweep over arc-shaped surface strips 2a-2d, whereby for reasons of safety even the corresponding area of the travel path 1 is searched. After a surface strip 2a-d has been searched in this way, the vehicle 10 is moved further by a strip width and the jib 20 swivelled again. The length of the jib can amount to 20 m, whereby a terrain strip with an arrangement of six measuring heads 40 can have a width of 3 m and more. With this dimensioning of the device, it is possible to search about 1 to 2 hectares of terrain for explosive objects within an hour.
The following measuring systems, for example, can be used as measuring heads:
1. Magnetometer for detection of Fe materials,
2. Magnetic field variometer for detection at greater traveling speeds,
3. Sensors for measuring the electrical conductivity of the soil with low frequency signal (up to 100 KHz), whereby foreign bodies in the soil which alter the electrical conductivity of the homogenous soil structure can be detected up to 20 m deep,
4. Geo-radar, which operates in the high frequency range of 100 MHZ-2 GHz.
Foreign bodies which deliver a response signal for the high frequency measuring signal, including excavations in the soil, abrupt structural changes such as cavities, deposit edges etc., can be detected up to 20 m deep. In all cases, preferably an electronic data processing assisted evaluation of the measurements is undertaken in the test room cabin 13.
In order to be able to adjust the measuring heads 40 at a predetermined distance over the terrain strips 2a-d to be examined, a first lifting cylinder 25 is mounted on the swivelling platform 24 and a second lifting cylinder 27 is mounted on the front end of the rear jib 21, which engages in fulcrum 30 on the front jib 23 through an activation rod 29.
The measuring heads 40 are suspended freely swinging on the front jib 23 in a row alongside one another on cords 43, wherein the cord 43 can be identical with the measuring conduit 41. Above the measuring heads 40, the cords 43 are connected with one another by a connecting cord 44 or a damping connection element, so that an uncontrolled swinging back and forth by the measuring heads 40 prevented. The suspension depicted here is designated as parallelogram suspension, because the measuring heads 40 are arranged parallel to the front jib 23 in every position of the front jib 23 and hang vertically, so that a vertical measuring direction is also always guaranteed. This becomes clear in FIG. 2, where the measuring head arrangement can be adapted to the slope inclination.
The travel and swinging movements of the vehicle 10 and the jib 20 are executed by the driver as long as no bomblets etc. are detected by the measuring heads. If, however, one or more of the measuring heads 40 detect objects in the ground, this is indicated by the evaluating apparatus located in the personnel and test room cabin 13, and the swinging control of the jib is then conducted by the operator (navigator) of the measuring instruments by override. The navigator swings the jib 20 back and forth until the find site is precisely established on his indicator. Thereafter, the ground marking device 60 is activated. This includes a stake marking device 66 arranged on the free end of the front jib 23 for rough marking and paint marking devices 61 allocated to the measuring heads 40 for fine marking. Both devices will be described in further detail in connection with FIGS. 11 to 14.
In order not to influence the measurement sensitivity of the measuring heads 40 unfavorably, the front jib 23 is manufactured from non-magnetizable material. This also requires that the ground marking device 60 likewise consist of non-magnetizable component parts and be so operated that no electromagnetic disturbance fields occur. In the embodiment depicted here, the stake marking device 66 and the paint marking device 61 are therefore operated by a compressed gas, especially compressed air.
From a main air container located on the vehicle 10, compressed air is pumped through a gas conduit 84 with a small cross section into an intermediate container 82 which is installed on the front section of the rear jib 21. The intermediate container here fulfills a storage function. Should the stake marking device 66 be activated, then the switchable valve 83 arranged adjacent to the intermediate container 82, which can be a magnetic valve, is activated by the navigator so that the gas stored in the intermediate container 82 abruptly escapes through the gas conduit 81, which has a larger cross section in comparison with gas conduit 84. The escaped gas reaches the stake marking device 66 with little resistance where it is conducted to the stake 67 ready for discharge. The pressure applied suffices to press the stake 67 out of its mounting and shoot it into the soil. The gas pressure and the amount of gas of the intermediate container 82 are adapted to the necessary shooting energy of the marking stake.
In the representation shown here the stake marking device 66 is arranged approximately centrally among the measuring heads 40. It is also possible to provide several stake marking devices 66 beside each other in order to designate the find site more exactly. The stakes 67, which likewise do not consist of magnetizable material, preferably have a luminous paint so that the find sites are recognizable even from a great distance.
Should a fine marking be undertaken in addition, then the navigator activates the paint spraying device 61, which basically has arranged alongside the respective measuring head 40 a valve with spraying nozzle and a corresponding supply conduit. A colored liquid is sprayed by means of a compressed air surge at the place on the soil where the allocated measuring head 40 has detected an explosive object.
In order to make the range of use of the device of the invention clear, the vehicle 10 in FIG. 2 is positioned on an elevation 3, from which it is exploring a slope 4 in which explosive objects 6 are situated. The connection of the cords 43 or measuring conduits 41 ensures that when the front jib 23 is inclined upward or downward, the complete measuring head system always behaves like a parallelogram, and the measurement by the measuring heads always takes place vertically. By suitable displacement of the lifting cylinders 27 and 25, the front jib 23 can be so inclined that the distance of all measuring heads from the surface of the incline 4 is basically of equal size. By means of lifting cylinders 25, 27, an independent swivelling about the horizontal axis of the rear jib 21 or of the front jib 23 is possible. The stake marking device 66 is likewise suspended swinging, so that it always hangs vertically downward following the center of gravity.
In FIG. 3 use over a body of water 5 is represented. Because of the great length of the jibs 21, 23, not too large a body of water can consequently be searched for explosive objects 6 from the shore.
In FIG. 4 the vehicle 10 is situated in a depression 7, from which an elevation 3 can be examined for explosive objects 6. Since it is a matter of a horizontal plateau here, the rear jib 21 is swivelled upward by means of the first lifting cylinder 25, and the front jib 23 is aligned horizontally by appropriate activation of the second elevation cylinder 27, so that all measuring heads 40 have the same distance from the surface of the earth. When adjusting the jibs 21, 23, an uncontrolled swinging of the measuring heads 40 fastened to the cords 43 would occur if these where not joined to one another through a connecting cord 44. The mutual coupling of the cords 43 suppresses the swinging motion. The cords 43 can also be replaced by vertically swinging rods of non-magnetizable material with a damping device installed on the suspension. In this case, the connecting cord 44 is unnecessary.
In FIG. 5 a further embodiment of the jib 20 is represented. While in the preceding figures the activation rod 29 fastened on the second lifting cylinder 27 is pivoted on the front jib 23 at point 30, here the activation rod 29 is pivoted on the probe holder 45. The front jib 23 is rigidly connected with the rear jib 21, and the probe holder 45 is pivotably mounted on the front jib 23 about fulcrum 32 around a horizontal axis. By activating the second lifting cylinder 27, the probe holder 45 can be swivelled. The probe holder 45 basically consists of a non-magnetizable rod or tube on which the cords 43 of the measuring heads 40 are suspended swinging freely. This embodiment has the advantage that the measuring heads 40 can be aligned without the distance from the vehicle 10 essentially being changed, as this is the case with a suspension on the front jib 23. Furthermore, there also exists a slope influence of the probe mounting 45 with greater differences in height between travel and measuring planes.
In FIG. 6 a further embodiment of the vehicle 10 is represented. Owing to the abbreviated construction of the test room cabin 13, the jib 20 can be attached to the chassis of the vehicle 10. In the representation shown here, a conventional mobile crane 28 is used for the jib 21, on whose front end the front jib 23 is hinged. The displacement possibilities of the rear and front jibs 21, 23 correspond to those of previously described embodiments. If necessary, an intermediate jib 22 can be provided between the two jibs 21, 23.
The measuring heads 40 are suspended on the probe holder 45, whereby this is aligned perpendicular to the direction of travel. It can be seen in this representation that in the direction of travel in front of the respective measuring head, a valve 64 and a spraying nozzle 63 are arranged, by means of which the paint for marking the find site is sprayed on the soil. The spraying nozzle 63 is supplied through the paint pressure conduit 62, which is likewise suspended freely swinging.
The probe holder 45 is rotatably arranged on the front jib 23 and can be rotated around a vertical axis by means of the electrically operated swivelling roller 48 and the swivelling roller 46 as well as the driving cord 49. The swivelling roller 48 with electric drive has the job of constantly aligning the probe holder 45 at right angles to the direction of travel according to the swing position of the rear jib 21. With the aid of the linear drive device 47, the intermediate jib 22 can be lengthened or shortened.
An appropriate working example is represented in FIG. 7. The probe holder 45 covers a surface strip with the measuring heads 40 mounted on it, which is wider than the vehicle 10. This is especially advantageous when the ground in front of the vehicle 10 is to be searched as well. The jib 20 can be swung into a predetermined position, wherein the probe holder 45 is aligned at right angles to the direction of travel corresponding to this deviation. If the vehicle 10 is moved continuously, parallel surface strips 2a, 2b or 2c, 2d and 2e can consequently be searched for explosive objects. With each trip by the vehicle 10, the jib 20 and the probe holder 45 are brought into the new position. Stopping the vehicle, as is the case in the operating mode in accordance with FIG. 1, is not necessary here.
But even when executing swivelling motions according to FIG. 1, it can be advantageous to reset the probe holder 45 correspondingly. A working example is represented in FIG. 8. During the swinging of the jib 20 the probe holder 45 is reset, such that it is always aligned in the direction of travel. The surface strip 2a swept over hereby narrows toward the outside, which, however, has the advantage that the margin of the area to be examined is precisely recorded. When the outer swivelling position is reached, the vehicle 10 can be moved along, and the swivelling movement of the jib 20 is conducted in the opposite direction, whereby the probe holder 45 is likewise reset. The swivelling movement is represented by the arrows drawn in.
FIG. 9 depicts an embodiment with a bent front jib 23 to which the measuring heads 40 are basically rigidly fastened. The measurement heads 40 can be attached to the front section 34 of the front jib 23 by elastic elements 50 which, for example, can be constructed in the form of a bellows. On the one hand, a rigid attachment is guaranteed in this way, so that even when raising the front jib 23 out of position I, the measuring heads 40 retain their arrangement in relation to the jib 23 (see position II). It is thereby possible to align the direction of measurement of the heads 40 perpendicular to the surface of a slope 4. The rigid attachment of the measuring heads 40 is to be understood such that, upon encountering an obstacle, a deviation of the measuring heads 40 is still possible.
In FIG. 10 the stake marking device 66 is represented in enlargement. A mounting 85 is suspended swinging on the front jib 23, which mounting is connected with the rotary transmission 76. On the rotary transmission 76, a mounting star 68 is pivotably mounted. The mounting star 68 has guide tubes 69 arranged in a star-shaped manner, which are equipped with stakes 67. Coupled with the mounting star 68 is a winding drum 87, to which a rubber tension belt 72 is fastened, which passes over a guide pulley 86 fastened to the mounting and is attached to the mounting 85. Charging the mounting star 68 takes place manually by introducing the marking stakes 67 until reaching a stop location. By insertion in the sequence indicated a prestressing is reached with the aid of the rubber tension belt 72 which suffices for a complete rotation of the mounting star 68. The marking stake situated in the shooting position lies against a stop 70 of the mounting 85. When this stake is shot off, the mounting star 68 rotates further owing to the tension of the rubber tension belt 72 until the succeeding stake 67 lies against the stop. After shooting off the last stake, the stop 71 of the guide tube 69 lies against stop 70.
In FIG. 11 the stake marking device 66 represented in FIG. 10 is shown in side view. The front jib 23 is represented as a plastic tube in which the compressed air conduits 77 and 62 as well as the measurement conduit 41 are laid. The compressed air conduit 77 leads to the rotary transmission which accommodates the mounting star 68. The compressed air consequently arrives at the stake 67 located in the shooting position, which has at the upper end a locking groove 73, in which the locking pin 75 of a locking lever 74 engages. When the marking stake 67 is acted upon by a compressed air surge, the force of the locking lever 74 is overcome and the stake 67 is shot out of the guide tube 69.
The paint pressure conduit tube 62 has on its lower end a valve 64 with a spraying nozzle 63. Paint liquid is likewise sprayed through the spraying nozzle 63 under the action of pressure.
In FIGS. 12 and 13 a further embodiment of the stake marking device 66 is represented. The stakes 67 are arranged in a drum 80 which is swinging suspended by a mounting 85 on the front jib 23. The drive of the drum 80 likewise takes place by a rubber tension belt 72, which is wound over the upper end of the drum 80. A compressed air conduit 77 is likewise provided, which ends at the stake 67 located in the shooting position. The stake 67 situated in the shooting position is likewise held by a locking lever 74 by means of its locking pin 75. When a compressed air surge is emitted through the compressed air conduit 77, this is shot out of the drum 80, which immediately moves on into the next position. Corresponding to the previously described embodiments, stops 70, 71 are also provided here.
When all stakes 67 have been shot off, the mounting drum 80 is rotated so far in the direction of the arrow that the stop 70 strikes upon stop 71, which is fastened to the lower end of the rotary transmission 76 and consequently prevents a further rotation of the drum 80 in relation to the rotary transmission 76. This way a total unstressing of the tension belt 72 is prevented and loading is simplified.
With too hard or stony soils, a marking buoy 100 is used as stake 67. It functions in accordance with FIG. 14 according to the gravity self-uprighting principle and is subject to the condition m 1 .a 1 >m 2 .a 2 . The shaft 102 should be constructed as lightly as possible, and has a locking groove 73 for accommodation into the stake marking device. The relatively heavy lower part 101 has the object of moving the marker buoy 100 into a standing position from any position. The hollow space 103 is so proportioned that the upright buoy can float. | There is described a device for the detection of objects lying in the earth which, irrespective of topography, soil structure and state of the terrain, permits high surface yields with great precision in identifying the position of the objects to be detected without endangering the operating personnel. On a mobile device (10) is arranged at least one jib (20) swivellable about a vertical axis, on whose free end are arranged adjacent to each other several measuring heads (40) for sweeping over strip-shaped surface areas (2a-d) of the terrain to be investigated. With the measuring heads (40) on the free end of the jib (20) at least one ground marking device (60) is arranged for distinguishing the find site determined by the measuring heads (40). The ground marking device (60) includes a paint spraying device (61) as well as a stake marking device (66) next to each measuring head (40). | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to an arrangement in a sewing machine of the type which is provided with an electronic control unit, the arrangement comprising a needle mechanism having a needle bar, a presser bar provided with a presser foot and actuated by a resilient means in order to provide a controllable presser foot pressure against the cloth to be sewn, and a lifting device for adjusting the presser foot between an operative position and an inoperative position spaced from the cloth.
According to the invention, in a sewing machine of the above-mentioned kind extended and improved sewing functions have been obtained. An object of the arrangement according to the invention is to provide power-driven elevation of the presser foot to an inoperative position when the actual seam is completed. Another object is to provide an intermittent, limited elevation of the presser foot during the sewing procedure, the cloth being held during stretching of the sewing-thread and released when the needle is at its top position in order to enable manual cloth feed. Another object is to provide an intermittent, limited elevation of the presser foot when the needle is at its bottom position and engaging the cloth, to enable lateral cloth feed by means of the needle. Another object is to enable control of the presser foot pressure to a preferred value irrespective of the thickness of the cloth. A further object is to enable sensing of the cloth thickness and to adjust the sewing-thread tension in relation to the sensed value.
SUMMARY OF THE INVENTION
The above-mentioned objects have been obtained by means of an arrangement of the kind mentioned in the introduction which according to the invention is characterized in that the lifting device comprises a power-driven lifting lever cooperating with the presser bar to adjust the presser foot between said positions and a third, operative position in which the presser foot pressure is relieved, said lifting lever being operatively connected to said resilient means for controlling the presser foot pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail in the following with reference to the accompanying drawings, in which
FIG. 1 is a view of the arrangement according to the invention as seen from the back of the sewing machine,
FIG. 2 is a section along line II--II of the arrangement shown in FIG. 1,
FIG. 3 is a partial end view of the arrangement shown in FIG. 1,
FIG. 4 is a top plan view of the same arrangement, and
FIGS. 5-7 are partial side views of the arrangement in different positions.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The arrangement shown in the drawings, which is intended to constitute a portion of a domestic sewing machine, comprises a vertically movable needle bar 10 provided with a needle 11 and a likewise vertically movable presser bar 12 provided with a presser foot 13. The presser bar is provided with a horizontal pin 14 at the top end thereof.
The vertical movement of the presser bar is provided by means of a lifting lever 15 which is rotatably journalled on a shaft 16 and provided with an abutment 17 cooperating with the pin 14. The lifting lever is powered by a stepping motor 18 via a reduction gear 19 having a pinion 20 meshing with a gear segment 21 of the lifting lever. In order to obtain an appropriate, resilient presser foot pressure a tension spring 22 is provided which extends between the pin 14 of the presser bar and a horizontal pin 23 provided on the lifting lever 15. The presser foot pressure can thereby be controlled by means of the lifting lever, as will be described in more detail in the following.
In order to determine the position of the presser bar and the presser foot, the arrangement comprises a code disc 24, one end of which is rotatably journalled on the shaft 16 and the other end of which is movably connected to the presser bar by means of an elongated opening 25 through which the pin 14 extends with a close fit. By means of a differential gauge comprising optical position sensors 26 attached to the lifting lever 15 and cooperating with a toothed segment 27 of the code disc the mutual positions of the lifting lever and the code disc are determined. When the presser foot is in its elevated position and thus not engaging the cloth below, no mutual movement of the lifting lever and the code disc takes place. When the presser foot is lowered and engages the cloth, whereby its descending movement is stopped, the continuing downward movement of the lifting lever 15 will result in tensioning the spring 22 and a corresponding increase of presser foot pressure. With a knowledge of the spring constant, the position difference sensed by the sensor 26 provides a indication of the presser foot pressure. A suitable presser foot pressure is set by the control unit of the machine with regard to input values of cloth material, seam selection, etc.
During normal sewing (FIGS. 3 and 5) the cloth is held between the presser foot 13 and a supporting needle plate 29. When the thickness of the cloth varies, for example due to a varying number of cloth layers, the presser bar will be displaced, which in a conventional sewing machine will lead to a variation of the presser foot pressure due to actuation of the spring tension. Such variation of the presser foot pressure in relation to the cloth thickness is in most cases disadvantageous to the sewing result. The arrangement according to the invention offers the possibility to avoid this drawback in that the movement of the presser bar is sensed by the differential gauge 26, 27, and by keeping the sensed value constant it is possible, if preferred, to provide a constant presser foot pressure irrespective of variations of the cloth thickness. This is obtained in that the position of the lifting lever 15 is adjusted by means of the motor 18 a distance corresponding to the displacement of the presser bar, whereby the tension of the spring 22 is maintained unchanged. It is also possible to obtain any desired relation between the presser foot pressure and the cloth thickness that might be appropriate for the actual sewing operation. In such case, the preferred relation between the presser foot pressure and the cloth thickness is set by means of the control unit of the sewing machine.
When the presser foot is to be adjusted to the elevated position shown in FIG. 6, the motor 18 is actuated to assume an angular position pre-programmed in the control unit, whereby the abutment 17 of the lifting lever engages the pin 14 of the presser bar and the presser foot is raised to a predetermined position. In addition to a normal elevated position, the machine preferably has a second elevated position in which the presser foot is raised a further distance to enable inserting extra thich cloth under the same. This extra elevation is preferably activated by keeping the control button for raising the presser foot on the control panel (not shown) of the machine depressed for a suitable, predetermined time.
In FIG. 7, the presser foot 13 is shown in a position in which it is raised just enough to relieve the presser foot pressure whereby the cloth is not held in a fixed position but can be moved. To provide adjustment to this position the stepping motor is activated for lifting until the movement sensed by the differential gauge 26, 27 has ceased, and then an additional predetermined number of steps, to release the cloth. This position can be used optionally in two different ways during the sewing operation.
In a first sewing program utilizing this pressure relief the machine is programmed to release the cloth temporarily during a short period when the needle is in its top position in which a cloth feed is normally carried out by means of the feed dog of the machine. Due to the fact that the cloth is not fixed in this stage, a manual cloth feed can be made instead of the automatic cloth feed which is then preferably made inoperative. By the end of the mentioned period the presser foot returns to its lowered position and normal presser foot pressure, whereby the cloth is held during stitch formation and thread tensioning. This sewing program thus permits manual cloth feed in any desired direction and can preferably be used in for example basting or darning.
In a second sewing program, the cloth is temporarily released for a short period when the needle is in its lower position and thus engages the cloth (FIG. 3). In this case, lateral cloth feed is provided by the zigzag mechanism of the machine. In the illustrated embodiment, this mechanism comprises a stepping motor 30 provided with a pinion 31 engaging a toothed segment 32 provided on a lever 33 which is rotatably journalled on a shaft 34. The lever 33 is connected via a link 35 to the bearing of the needle bar 10 whereby the needle can be displaced laterally a distance which can be selected by the zigzag control of the machine. As is known, such lateral displacement of the needle normally takes place at the top position of the needle to provide zigzag stitching. In the sewing machine according to the invention, the cloth is released at the lower position of the needle and the cloth is then displaced laterally by means of the zigzag mechanism and the needle 11. The presser foot is then lowered again and a normal presser foot pressure is applied.
By utilizing this sewing function it is possible to provide a seam extending cross-wise of the normal sewing direction of the machine. In addition, by combining this lateral cloth feed with normal forward or backward cloth feed at the top position of the needle and selecting a preferred stroke for both said mutually perpendicular cloth feeds, it is possible to produce a seam extending in any preferred direction. It should be easily realized that this provides new and generally unlimited possibilities of producing utility as well as fancy seams. It is an advantage in comparison with lateral feed by the normal cloth feed dog, as is provided in certain types of sewing machines, that much longer lateral feed strokes can be obtained, by utilizing the entire zigzag width for the lateral cloth feed.
A further advantageous feature of the described arrangement is that it provides the possibility of continuous control of the cloth thickness during the sewing procedure. For determining the cloth thickness, the position of the presser foot is calculated which is obtained with the aid of the angular position of the stepping motor 18 and the value sensed by the differencial gauge 26. The actual presser foot position is compared with a reference position in which the presser foot engages the needle plate without any intermediate cloth. The reference position is stored in the memory of the control unit in the form of an angular position of the motor 18. The sensing of the cloth thickness is used for adjusting the tension of the sewing thread. This is carried out in such way that the previously set thread tension, which is selected with regard to cloth material and type of seam, is continuously fineadjusted in relation to the actual cloth thickness by utilizing the sensed value for controlling a servo motor (not shown) which actuates the thread tensioning device of the sewing machine. The adjustment is made such that the thread tension increases with the cloth thickness. As the thread tension is constantly adjusted to the actual cloth thickness, it is possible to obtain a seam of high and even quality irrespective of the variations of the cloth thickness. | A sewing machine of the type having an electronic control unit is provided with an arrangement comprising a needle mechanism with a needle bar, a presser bar (12) provided with a presser foot (13) and actuated by a resilient means (22) to provide a controllable presser foot pressure on the cloth (28) to be sewn, and a lifting device for adjusting the presser foot between its operative position and an inoperative position spaced from the cloth. According to the invention, the lifting device comprises a power driven lifting lever (15) coacting with the presser bar (12) for adjusting the presser foot (13) between said two positions and a third, operative position, in which the presser foot pressure is relieved, and the lifting lever (15) is operatively connected to said resilient means (22) for controlling the presser foot pressure. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to amplitude modulating techniques and, more particularly, to the task of amplitude modulating a high powered laser beam.
There are several applications in which it is desirable to modulate a beam of electromagnetic radiation for transmission. One such application is to provide an amplitude modulated source of infrared radiation to be used as sensing beams for gathering three dimensional image information which can be retrieved and later processed to extract useful data from a sensed object. A particularly powerful image processor for analyzing such image data is disclosed in U.S. Pat. No. 4,167,728 to Sternberg and related improvements such as those disclosed in U.S. Ser. No. 73,818, filed Sept. 10, 1979, to Sternberg, now U.S. Pat. No. 4,322,716, which are hereby incorporated by reference. Where these sensors are designed to detect objects whch are far away, the source of the detection beam must be relatively powerful and the beam must be amplitude modulated within a prescribed frequency range to achieve optimum performance. Preferably, the detection beams are derived from a CO 2 laser providing 4-40 watts of power and providing a beam of 5-7 millimeters in diameter.
One widely used technique for modulating light beams is through the use of electro-optical devices. Electro-optical modulation unfortunately entails bi-refringent crystals, polarization analyzers, and quarter-wave plates. The high drive powers (in order of 4-40 watts) required for electro-optical modulation of high power laser beams also leads to problems resulting from RF heating when modulation is carried out in the megahertz range.
Traveling wave acousto-optic modulators are, on the other hand, less expensive and simpler devices which require less drive power for achieving amplitude modulation of collimated laser radiation. In traveling wave acousto-optical modulators the laser beam is passed through a medium such as germanium which has an acoustic transducer mounted on one surface. The acoustic transducer is driven by a relatively high frequency source (typically 40-50 megahertz) which generates an acoustical wave which travels from one end of the medium and passes out of the other end. Modulation is accomplished by turning the acoustical drive source on and off. Modulation frequencies of up to tens of megahertz may be achieved if the laser beam is focused to a very small diameter.
Thus, it can be appreciated that while traveling wave acousto-optical modulation techniques may be valuable for low power laser beams, this approach is not practical for moderate to high power beams. The power density within the focal volume of the higher powered beams may readily exceed the damage threshold of the optical medium. It has been discovered that continuous wave CO 2 lasers with several watts of output power may only be modulated to frequencies of no higher than about one megahertz using traveling wave acousto-optical devices. Even so, the modulation efficiency is very low, approaching only about 30%. Those skilled in the art will appreciate that this results in a very poor signal to noise ratio.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of this invention to provide a method and a device for efficiently amplitude modulating a high powered beam of infrared radiation at relatively high modulating frequencies, preferably in excess of one megahertz.
It is a further object of this invention to accomplish the above objective in a comparatively inexpensive manner requiring low drive power which will operate over an extended period of time in an extremely satisfactory manner.
These and other objects of the invention are provided by way of generating a standing (as compared to traveling) acoustical wave front in an acousto-optical medium, such as a germanium crystal and using the cyclical collapsing acoustical wave front to modulate a high powered laser beam passing through the medium. An acoustical transducer on the medium is driven by a low powered source of drive signals at half the desired modulation frequency.
In the preferred embodiment, a laser is used to generate a 4-40 watt beam with a diameter of 5-7 millimeters. The beam is passed through a germanium crystal having a lead zirconate titanate (PZT) acoustic transducer on one surface. A standing acoustical wave front is generated in the crystal generally perpendicular to the axis of the beam by applying a drive signal of less than two watts at a frequency less than ten megahertz to the transducer.
Very little drive power is required and almost 100% modulation has been achieved even though the drive frequencies are so low. Conventional thinking in the art would lead one to believe that good modulation efficiency could only be obtained while operating acousto-optical devices in the Bragg region (drive frequencies above 26 megahertz) and that poor results would be obtained for devices characterized as Raman-Nath cells having much lower drive frequencies.
Another feature of the present invention includes provision of a unique construction for carrying out the above modulation technique. A heat sink includes a major upper surface and an upstanding portion with an end face extending perpendicular to the major surface. The acousto-optical medium takes the form of an elongated block having its bottom affixed to the major surface of the heat sink and an upper portion of one side affixed to the end face of the upstanding portion of the heat sink. A strip of acoustic transducer material is secured to an opposite lower side of the optical medium beneath a projection of the contact area between the medium and the heat sink end face. Drive means are coupled to the transducer to generate the standing acoustical wave in the lower portion of the medium having an unobstructed opposite lower side spaced from the heat sink end face. In such manner the acoustic wave is efficiently reflected back upon itself in that portion of the medium through which the beam passes. Divergent acoustic waves are coupled out of the medium by way of the heat sink end face thereby precluding deleterious acoustic waves from returning to the modulation region.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the present invention will become apparent to one skilled in the art by reading the following specification and by reference to the drawings in which:
FIG. 1 is a partial isometric view of a device made in accordance with this invention for amplitude modulating a high powered light beam; and
FIG. 2 is a cross-sectional view of the device of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment of this invention the amplitude modulation is carried out by way of modulating device 10. Device 10 employs a heat sink made of aluminum or other conventional thermally conducting material. Heat sink 12 is formed of two members 14 and 16. Member 14 has an upper major surface 18 to which the lower surface of member 16 forms the upstanding portion of the heat sink and is secured, for example, by way of thermally conductive material. Member 16 has a vertically extending end face 20 defined by recess 22. Passageway 24 serves as a conduit for transporting recirculating coolants, such as water, from a reservoir (not shown).
A rectangular solid block 26 serves as the acousto-optical medium. In the preferred embodiment, block 26 is a germanium crystal with the dimensions of 12×15×40 millimeters. As shown in FIG. 1, device 10 is adapted to receive a laser beam from laser 28 such that the beam 50 enters the block 26, propagates through the germanium crystal along the 112 crystal axis, and exists the block 26 as a zeroth order or undeflected beam 50'. The laser beam is also positioned so that it passes through the lower portion of block 26 between recess 22 and an acoustic transducer 30. Transducer 30 preferably takes the form of an 8×35 millimeter strip of lead zirconate titanate (PZT) having gold electrodes 32 and 34 on opposite surfaces thereof, electrode 34 curling over one edge of PZT transducer 30 to provide an easily accessible connection surface. A source 36 of radio frequency drive signals are connected to electrodes 32 and 34 by way of coaxial cable 38. Suitable impedance matching circuitry (not shown) may also be employed. In the preferred embodiment, thirty gauge copper wires 40, 42 are bonded to the electrodes using silver paint, with the opposite ends of wires 40, 42 being connected to the grounded shielding and insulated conductor in cable 38, respectively, which are, in turn, connected to source 36 through the impedance matching circuit. PZT transducer 30 is mounted to the lower portion of one side of germanium block 26 using suitable araldite material.
Germanium block 26 is held in good thermal contact with heat sink 12 by way of spring clips 44, 46 and 48. The bottom surface of block 26 thus is flush with major surface 18 of heat sink memeber 14. The upper side surface of block 26 is pressed against end face 20 of heat sink member 16. In such manner the side surface of block 26 directly opposite transducer 30 remains unobstructed for the purposes which will now be explained.
The operation of the present invention will be described in connection with a particular example in which the primary purpose is to amplitude modulate an infrared frequency laser beam (having a beam diameter of 5-7 millimeters and delivering 4-40 watts of power at carrier or modulating frequencies in excess of 1 megahertz). In particular, the present invention will be described in connection with amplitude modulating a CO 2 laser 28 which provides a beam of about 6 millimeters in diameter and delivers about 16 watts of power. Device 10 will operate to modulate the continuous wave beam 50 from laser 28 to provide an amplitude modulated zeroth order (or undeflected) beam 50' at its output which is modulated at a frequency of 7.8 megahertz.
A resonant or standing acoustic wave is generated along the 111 crystal axis direction in germanium block 26. The standing wave is established by launching an acoustic wave into block 26 from transducer 30 and allowing the wave to be reflected by the opposing parallel free surface bounded by recess 22. The width of germanium block 26 is chosen to be an integer multiple of the acoustic half wave lengths supplied by transducer 30 so that the counter propagating acoustic waves interfere to set up a resonant or standing acoustic wave. The acoustic wave collapses (i.e., due to destructive interference) twice per acoustic cycle such that the modulation frequency of the ultimately transmitted laser beam is exactly twice the drive frequency applied from source 36 to the acoustic transducer 30.
By way of experimentation it was determined that the strongest resonant acoustic frequency for germanium block 26 is at about 3.906 megahertz and thus the RF drive source 36 is conditioned to provide drive signals to transducer 30 at about the same frequency. Drive source 36 may comprise a conventional tunable RF oscillator (such as GRC model 1211B) and a broad band power amplifier (such as ENI Model 240L) with a through-line RF watt meter. The CO 2 laser 28 was a Laakmann Model 16000 which was up-collimated to a diffraction-limited 5.6 millimeter diameter beam (2.6 mrad divergence) and provided 16 watts of radiation to be modulated. Up-collimation serves to reduce the power density of the laser radiation within the modulating device 10 and, more particularly, to reduce the laser beam divergence such that the diffracted orders are spatially separated in the far field.
Almost 100% modulation of the laser beam 50 into the zeroth order beam 50' is accomplished by modulating device 10 with the drive source 36 providing only a limited amount of power. In this example, drive source 36 need only provide drive power on the order of less than about 2 watts and, more particularly, about 1 watt.
One skilled in the art should now realize that the standing wave modulator device 10 of the present invention using relatively low acoustic frequency drive signals has several advantages over conventional traveling wave modulator devices operating in the Bragg region with much higher acoustic drive frequencies. Whereas the present invention provides nearly 100% amplitude modulation efficiency with about 1 watt of RF drive at about 4 megahertz, a conventional traveling wave Bragg device provides only about 30% deflection efficiency and that required 10 watts of RF drive at 35 megahertz. Additionally, it has been discovered that the modulator device 10 is much less sensitive to changes in orientation. Modulator device 10 can be tilted by ±3° with respect to the laser beam 50 with less than 10% loss in modulation efficiency. A much more considerable loss in efficiency is encountered when the traveling wave modulator device of the prior art is varied from the precisely defined Bragg angle. The modulator device 10, after being tuned for optimum modulation, can be left unattended for several hours without degradation of performance. The changing of RF drive power or incident laser power similarly has no deleterious effect upon the resonance of the device due to the excellent cooling arrangement provided by the heat sinking portion of the device 10.
The modulated laser beam as provided by the specific example set forth above finds particular applicability in an imaging sensor device. The beam is directed at the object 52 to be sensed. The distance between the sensor and various patterns in the scene can be readily detected by measuring the differences between the phases of successive beams rebounding off of the object. Since the acoustic transducer 30 is operated at a frequency of about 4 megahertz but the resulting beam is modulated at about 8 megahertz, very little radio frequency interference problems are encountered. For optimum usage as an image sensor device, laser 10 should provide electro-magnetic wave lengths between 8-12 microns and provide 4-40 watts of power with a beam diameter of 5-7 millimeters. The modulating or carrier frequency should be about 2-20 megahertz. The modulator device 10 and accompanying method for using it performs this function quite well.
However, it is expected that the present invention may find applicability in other applications. Greater or lesser modulating frequencies may be achieved by a selection of an acoustic transducer of appropriate half-wave thickness. The upper frequency limit is established by transducer technology, impedence matching and a loss of acoustic Q due to increased acoustic absorption at high frequencies. The lower frequency limit is established by the loss of acoustic Q which results from increased acoustic divergence or the overlapping of diffracted orders as the diffraction angle approaches the laser beam divergence.
Therefore, while this invention has been described in connection with specific examples thereof, no limitation is intended thereby except as defined in the appended claims. This is because other modifications will become evident to one skilled in the art after a study of the drawings, specification, and following claims. | A method and device for amplitude modulating a high powered beam of infrared radiation at frequencies in the megahertz range are disclosed. A laser is used to generate a beam of 4-40 watts of power and the beam is passed through as acousto-optical crystal having an acoustic transducer on one surface. A standing acoustical wave in the crystal is provided by a low powered drive signal at a frequency of one to ten megahertz. The beam is efficiently modulated by the standing wave at exactly twice the frequency of the drive signal. The device incorporates a heat sinking arrangement which serves to preclude deleterious action of divergent acoustical waves generated in the crystal, as well as to provide excellent removal of thermal energy. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to electro-optic modulators. More particularly, the present invention relates to electro-optic modulators having extended bandwidths.
BACKGROUND OF THE INVENTION
[0002] Electro-optic modulators are used in optical communications systems to rapidly modulate and optical signal in accordance with an electrical signal. In an electro-optic mode converter, a type of electro-optic modulator, an input beam of light having an input state of polarization (SOP) impinges on and traverses through an electro-optic waveguide that is subjected to an applied electric field. The applied electric field modifies the modal properties of the waveguide via the electro-optic effect. When the input SOP is not aligned with a principal axis of the waveguide, and the propagation speed of the light through the two principle axes differs, the beam of light at the output of the waveguide will generally have an output SOP different from the input one. With proper choice of input SOP, waveguide geometry and applied electrical field, it is possible to have the output SOP orthogonal to the input SOP. This allows the use of the electric field to control the mode conversion so that the output optical signal is modulated in accordance with a signal used to generate the electric field.
[0003] Structurally, an electro-optic mode converter or a modulator will usually include an electro-optic guiding layer such as a III-V semiconductor or LiNbO 3 -type material, an optical waveguide defined in the optical guiding layer and an electrode structure disposed in the vicinity of the optical waveguide. As a voltage is applied to the electrodes, an electric field is formed across the optical waveguide and modifies the modal properties of the waveguide such as the orientation of its principal axes and/or its birefringence thus allowing for a modification of the SOP of a light beam traversing the optical waveguide. In the ideal, the principle axes are rotated to 45° from an X-Y orientation, and the birefringence of the axes is then modulated to control the phase relationship of the two fundamental hybrid optical modes. The phase relationship in turn determines the output SOP.
[0004] U.S. Pat. No. 5,566,257, hereinafter referred to as '257, issued Oct. 15, 1996 to Jaeger et al., which is incorporated herein by reference, discloses an electro-optic modulator having an electrode structure with two spaced apart conductive strips or electrodes disposed on either side of a single semiconductor optical waveguide. Each electrode includes projections, or fins, projecting towards the other conductive strip and disposed so as to affect the optical permittivity tensor of the waveguide material upon a voltage being applied to the electrodes. At the end of the projections, adjacent the waveguide, are pads, the geometry of which having an impact on the electrode structure capacitance.
[0005] The electrode structure of '257 is referred to as a “slow wave” electrode structure because it matches a microwave index to the optical index of the waveguide, so that a signal applied to the electrodes propagates through the signal path at the same velocity that the optical signal propagates through the waveguide. As a result, the optical signal can be cleanly modulated in accordance with the changing electric field generated by the application of a signal to the electrodes.
[0006] The teachings of '257 provide an electro-optic modulator requiring less electrical and optical power and capable of running at higher frequency than Mach-Zehnder type slow wave modulators such as described in U.S. Pat. No. 5,150,436, hereinafter referred to as '436, issued Sep. 22, 1992 to Jaeger et al., which is incorporated herein by reference.
[0007] For efficient operation, electro-optic mode modulators such as the one disclosed in '257 usually require a bias voltage to adjust the operating point of the modulator. The bias voltage may be applied to the signal electrode with the ground electrode connected to the ground of the package housing the mode converter in order to achieve current return. This method of biasing requires that a DC blocking circuit be disposed at the input of the electrode structure in order to prevent excessive voltage due to the biasing voltage from appearing in the modulation driving circuit. Furthermore, the DC blocking circuit must be such that it does not affect the modulation signal across the operational bandwidth of the modulator.
[0008] It would thus be desirable to have a mechanism for applying a biasing voltage to the mode converter that does not require a DC blocking circuit and that does not impair the operational bandwidth of the mode converter.
[0009] Additionally, electro-optic modulators as disclosed in '257 tend to have their electrodes exhibit a resistive loss of the electrical signal that increases as the frequency of the electrical signal is increased. This is due to the skin effect and leads to a substantial reduction of the electro-optic bandwidth of the modulator.
[0010] Consequently, it would be desirable to have a mechanism for alleviating the frequency dependent skin effect.
[0011] Another concern for electro-optic mode converters or modulators such as disclosed in '257 relates to their grounding. In order for the mode converter or modulator to exhibit proper radio frequency (RF) behaviour, the ground electrode of the modulator should be in electrical contact with the ground of the modulator package and, the connection length between the modulator and package grounds should be as short as possible. Conventional methods of accomplishing this connection usually lead to the appearance of mechanical stress in the mode converter as the temperature of the package varies. Such stresses adversely affect the performance of the mode converter, and can induce an unwanted strain-optic effect in the waveguide that changes its known parameters.
[0012] It would thus be desirable to have a grounding mechanism that provides proper RF behaviour and does not affect the mode converter performance as the temperature of the package housing the mode converter is varied.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to obviate or mitigate at least one disadvantage of previous electro-optic mode converters.
[0014] In a first aspect of the present invention, there is provided an electro-optic modulator. The modulator comprises and AC coupled ground electrode, a signal path electrode and a waveguide. The signal path electrode carries an electrical signal, and is disposed substantially parallel to the AC coupled ground electrode. The waveguide is disposed between the signal path and AC coupled ground electrodes. The waveguide transmits an optical signal and modulates the polarization of the optical signal in accordance with an electric field generated between the signal path and AC coupled ground electrodes in response to the transmission of the electrical signal through the signal path electrode.
[0015] In an embodiment of the first aspect of the present invention, the AC coupled ground electrode and the signal path electrode each include a series of projections, extending from an edge towards the waveguide, and each of the series of projections imparts a capacitance to the signal path. In another embodiment, the AC coupled ground electrode includes a plate capacitively coupled to ground by at least one capacitor, the capacitor optionally being formed by having the AC coupled ground electrode is connected to a plurality of ground plates by a dielectric, the connection through the dielectric forming a capacitor to capacitive couple the AC ground electrode to ground. In a further embodiment, the electro-optic modulator includes a biasing means coupled to the AC coupled ground electrode. The biasing means biases the AC coupled ground electrode, the bias level can be used to set an operating point for the modulator.
[0016] In another embodiment, the signal path electrode includes a signal path input for receiving the voltage signal and a signal path terminal end having resistive termination to attenuate back reflections, where optionally the signal path electrode is disposed on an optical semiconductor chip and the signal path input and the signal path terminal end, are disposed on a separate chip and are connected to the signal path electrode by bond wires. In another embodiment of the present invention the waveguide is disposed on a semiconductor material, which is optionally Al x Ga 1-x As, x being selected from 0 and 1. In another embodiment, the electro-optic modulator includes a predistortion network connected to an input to the signal path electrode, the predistortion network for distorting signals transmitted across the signal path electrode to compensate for signal distortion in the signal path electrode, where optionally the predistortion network includes interconnected resistors and capacitors to distort the signals to compensate for skin effect resistive loss in the signal path electrode.
[0017] In other embodiments, the AC coupled ground electrode is mounted on the surface of a first chip, and is capacitively coupled to a ground plate on the surface of a second chip, which is connected to a ground plane on the base of the second chip by at least one of vias and edge wrap around connections. In one embodiment, the AC coupled ground electrode is indirectly capacitively coupled to the ground plate.
[0018] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
[0020] FIG. 1 is a perspective view of a preferred embodiment of the electro-optic modulator;
[0021] FIG. 2 is a cross-sectional view of the electro-optic modulator of FIG. 1 ;
[0022] FIG. 3 is a cross-sectional view of the electro-optic modulator of FIG. 1 depicting an insulator disposed between the chips of the modulator;
[0023] FIG. 4 is a graph showing the improved performance of the electro-optic modulator of the present invention over a prior art modulator; and
[0024] FIG. 5 is a cross-sectional view of the elector-optical modulator of FIG. 1 depicting means for grounding the modulator.
DETAILED DESCRIPTION
[0025] Generally, the present invention provides a system for extending the operational bandwidth of an opto-electronic polarization modulator.
[0026] In the system of the present invention, an electrical signal path is used as an electrode, as is an AC coupled ground. As an electrical signal is applied to the electrical signal path, an electric field is generated between the electrodes. This electric field is used to modulate the polarization state of light input to the modulator. The AC coupled ground allows for the application of a DC biasing voltage, which allows easy selection of an operating point of the circuit. The AC coupling is achieved by capacitively coupling a DC biased plate to a ground plate. The physical connection can be a series of ground plates, on the same chip, or to a single ground plate, with a dielectric disposed between the two. This creates a distributed capacitance between the two plates, which appears substantially as a short circuit over the operational bandwidth of the modulator, and an open circuit to the applied DC voltage. As a result, a biasing voltage can be applied, without the difficulty experienced in the prior art. The use of a series of ground plates allows for a discretized distributed capacitance, so that in the event that one of the segments has the dielectric misapplied, the capacitive coupling is still maintained. Further enhancements, including the use of discrete large capacitors connected to the AC coupled ground allow the ground to have the desired characteristics while maintaining a wide frequency response band.
[0027] A perspective view of a preferred embodiment of the present invention is shown in FIG. 1 . There, electro-optic modulator 1 is shown as having a first chip 2 , which includes a semiconductor material and an electro-optic semiconductor-based waveguide 3 , disposed between a first electrode 4 and a second electrode 5 . The semiconductor-based waveguide 3 is preferably a ridge waveguide including Al x Ga 1-x As, x being between 0 and 1.
[0028] As seen in FIG. 2 , which is a cross-sectional view taken along line AB of FIG. 1 , first electrode 4 is disposed atop an insulating layer 10 , which is overlapping grounding pads 11 . Grounding pads 11 may be disposed on an insulating buffer layer (not shown).
[0029] Also depicted in FIG. 1 , are first end 12 and second end 13 of the signal path electrode 5 . Additionally, first electrode 4 and second electrode 5 are shown as being substantially parallel to each other and to waveguide 3 . However, such parallelism is not necessary to practice the present invention.
[0030] Continuing with FIG. 1 , first electrode 4 and second electrode 5 are provided with a plurality of projections 14 extending from a side of the electrodes towards waveguide 3 . Projections 14 are for imparting a capacitance to modulator 1 . Some possible designs of projections 14 have been previously disclosed in '257 and '436 where the appellations “fins” and “fins” with “pads” are used instead of “projections”.
[0031] Another chip, chip 15 , is shown disposed on the left hand side of chip 2 and is preferably made of an insulator material containing, for example, alumina i.e. Al 2 O 3 . Chip 15 includes conductive input segments 20 a and 20 b, the latter being in electrical contact with first end 12 of electrode 5 , the electrical contact being provided by one of conductive wires 21 , which are preferably gold wires. Disposed between conductive input segments 20 a and 20 b, and electrically coupled to conductive input segments 20 a and 20 b, is a pre-distortion circuit 22 , also referred to as a predistorer, which will typically include, but is not limited to, a resistor and a capacitor. Predistortion circuit 22 , as illustrated, is part of the presently preferred embodiment, but should not be viewed as essential.
[0032] Chip 15 is also depicted as including conductive terminal segment 23 being in electrical contact with second end 13 of signal path electrode 5 , the electrical contact being provided by a bond wire. Connected between conductive terminal segment 23 and ground 24 is resistive termination 25 . One skilled in the art will appreciate that the signal path is resistively terminated to ensure that constant impedance is found on all parts of the signal path. Chip 15 includes ground electrode 30 which is in electrical contact with grounding pads 11 using a set of conductive wires 21 . Additionally, capacitors 31 are disposed atop ground electrode 30 , and can be formed by sandwiching insulating layer 32 between a top plate and the ground electrode 30 as shown in FIG. 2 . Moreover, conductive bias pad 33 is disposed on chip 15 and is electrically coupled to first electrode 4 via one of conductive wires 21 .
[0033] An additional feature of the present invention is depicted in FIG. 3 where a space separating chips 2 and 15 includes a dielectric material 34 such as, for example, a benzocyclobutene-based polymer, for reducing impedance of conductive wires 21 . The application of the dielectric material 34 is preferably done in a manner that minimizes the stress imparted to chip 2 .
[0034] Fabrication and micro-fabrication techniques for depositing patterns of conductive materials on insulator and semiconductor materials as well as techniques for depositing insulating layers on insulators, conductors and semiconductors together with other fabrication techniques used in the practice of the present invention are well known in the art of device fabrication and will not be described here.
[0035] Further structural and operational features of electro-optic modulator I will now be described in relation to the operation of the modulator.
[0036] A light beam 35 , having an input state of polarization (SOP) is provided to waveguide 3 at input port 40 and propagates through waveguide 3 . An electrical signal is applied to conductive input segment 20 a, and is then carried to the signal path electrode 5 over a bond wire. Prior to passing to signal path electrode 5 , the input electrical signal is modified by predistorer 22 to compensate for anticipated distortion related to the skin effect resistive loss in the signal path. As a signal is carried along signal path electrode 5 , an electric field is generated between electrodes 4 and 5 , which resulting in a field across waveguide 3 . The electric field across waveguide 3 modifies the optical properties of waveguide 3 and affects one or both of the birefringence and the orientation of principal axes of the waveguide. Light beam 35 will thus generally have its initial SOP modulated in accordance with the input electrical signal as it propagates through waveguide 3 , exiting waveguide 3 at port 50 . Modulation of the voltage signal leads to a modulation of the electric field, which modulates the optical anisotropy of waveguide 3 thereby modulating the SOP of light beam 35 .
[0037] The electrical signal applied to signal path electrode 5 may include a high frequency AC modulation extending up to and beyond 40 GHz. At such high frequencies, the electrodes are susceptible to the skin effect. As a result, high frequency AC current has a tendency to reside near the surface of signal path electrode 5 , which results in an effective augmentation of the resistive losses of modulator 1 . This decreases the effective bandwidth of the system. Pre-distortion circuit 22 , as previously described, can be used to intentionally distort the signal path to pre-emptively counter the skin effect. The performances of electro-optic modulator 1 , using a predistortion network 22 , and that of an electro-optic modulator not having a pre-distortion circuit are shown in FIG. 4 .
[0038] FIG. 4 presents a graph 51 plotting the electro optic frequency response, or electro-optic S 2 , as a function of frequency. Electro-optic S 21 is calculated as 20*log10(Vo/Vi) where Vo is the amplitude of the optical modulation as detected by an infinite bandwidth optical power detector and Vi is the amplitude of the electrical signal applied to conductive input segment 20 a. The 3 dB bandwidth of modulators such as modulator 1 is determined by using their low frequency response as the 0 dB reference and then determining the frequency at which the response decreases by 3 dB. FIG. 4 shows trace 52 measured for a modulator not having pre-distortion circuit 22 . In this case, the low frequency response is −0.5 dB and, therefore, the frequency at which the response has dropped by 3 dB is approximately 35 GHz. In the case of the response of modulator 1 , i.e. a modulator including pre-distortion circuit 22 , trace 53 shows a low frequency response of −1.5 dB. Therefore, the frequency at which the response has dropped by 3 dB is approximately 41 GHz. Thus, in the example of graph 51 , the presence of pre-distortion circuit 22 has improved the modulator bandwidth by approximately 6 GHz.
[0039] The geometry of ground electrode 4 and signal path electrode 5 is central to the performance of modulator 1 . The geometry of electrodes 4 and 5 is preferably designed to match the phase velocity of the electrical signal with the group velocity of light beam 35 as it travels through waveguide 3 .
[0040] Additionally, the voltage signal driving circuit (not shown) will have a nominal impedance, which is typically 50 n. The geometry of electrodes 4 and 5 is preferably designed to have a characteristic impedance matched to the voltage signal driving circuit. In order to avoid electrical back reflections from modulator I to the voltage driving circuit, resistive termination 25 is impedance-matched to the nominal impedance of the voltage signal driving circuit and electrodes 4 and 5 , and connected between conductive terminal segment 23 and ground 24 .
[0041] In order to operate efficiently, electro-optic modulator 1 is usually required to function within an operating range attained through a DC bias voltage. The AC coupled ground electrode 4 can easily be DC biased to select an operating point for the modulator. In previous designs such as, for example, those disclosed in '257, it is also possible to apply a DC bias to the signal electrode. However, as mentioned above, this requires that a DC blocking circuit be disposed at the electrical input of the modulator in order to prevent excessive voltage, resulting from the DC biasing voltage, from appearing in the modulation driving circuit. Furthermore, the DC blocking circuit must be designed so that it does not affect the modulation signal across the very wide operational bandwidth of the modulator.
[0042] The present invention allows for the DC bias voltage to be applied to AC coupled ground electrode 4 by connecting a DC bias voltage source (not shown) to conductive bias pad 33 , which is in electrical contact with AC coupled ground electrode 4 via a bond wire. AC coupled ground electrode 4 is capacitively coupled to grounding pads 11 and is in electrical contact with capacitors 31 via conductive wires 21 . Grounding pads 11 are in turn in electrical contact with ground electrode 30 via conductive wires 21 . Furthermore, capacitors 31 capacitively couple the AC coupled ground electrode 4 to ground electrode 30 , which is ultimately connected to ground 24 . The use of discrete high capacitance capacitors 31 extend the operation bandwidth of the system to include lower frequencies.
[0043] This manner of applying the DC bias voltage to modulator 1 provides a capacitively coupled ground, also referred to as an AC coupled ground, which alleviates the need for a DC blocking circuit at the electrical input of modulator 1 . Furthermore, the capacitors formed by AC coupled ground electrode 4 and grounding pads 11 can be made to have sufficient capacitance to provide an effective low impedance ground path at low frequencies and yet, provide low inductance current paths for currents flowing into and out of AC coupled ground 4 , the low inductance being important in order to maintain a low impedance at the high frequencies. Additionally, the disposition of the capacitors formed by AC coupled ground electrode 4 and grounding pads 11 along the transmission axis of the waveguide, i.e. along the line joining ports 40 and 50 , allow for a substantially constant impedance along waveguide 3 .
[0044] Capacitors 31 formed between ground plates and ground electrode 30 modify behaviour of modulator 1 at low frequencies and will usually have higher capacitance values than those of the capacitors formed between ground electrode 4 and grounding pads 11 . This presently preferred feature provides a simple mechanism to extend the lower bandwidth of the circuit by providing a current path that appears as a low impedance at very low frequencies.
[0045] In order to prevent unwanted electrical modes of propagation along AC coupled ground electrode 4 and signal path electrode 5 upon the modulator being packaged, ground electrode 30 can be electrically connected to a package ground through ground 24 . An illustration of such an embodiment is provided in FIG. 5 , which illustrates a partial cross-sectional view of modulator 1 . Conductive through connection 60 is disposed in a bore through ground electrode 30 and the second chip 15 . Conductive through connection 60 , also referred to as a via, which is in physical contact with ground electrode 30 and lower ground electrode 30 b, is fastened to conductive package 62 by a conductive attach material 64 , for example solder or a conductive adhesive, which is connected to ground 24 . A plurality of through connections 60 are disposed in a similar manner at a plurality of locations on ground electrode 30 . Alternatively, or in addition to conductive through connections 60 , ground electrode 30 may include an edge wrap around connection, such as metalized wall 63 , allowing electrical contact between ground electrode 30 and lower ground electrode 30 b. Lower ground electrode 30 b, also referred to as a ground plane, makes contact to conductive package 62 by a conductive attach material 64 .
[0046] In addition to preventing unwanted electrical modes of propagation along first electrode 4 and second electrode 5 , the electrical connection mechanisms of ground electrode 30 to the ground 24 allow for a substantial reduction of temperature related effects on the performance of modulator 1 by reducing the need for the optical transmission chip 2 to be secured to the packaging in a manner that would apply stress to the chip under temperature changes. Void A prevents second attach material 64 b, which may be conductive or non-conductive and used to secure chip 2 to conductive package 62 , from wicking upwards into void B during assembly, thereby reducing mechanical interaction (which may result from temperature changes) of chip 2 and second chip 15 . Reduced mechanical interaction-of chip 2 and second chip 15 facilitates maintaining a stable position of chip 2 relative to conductive package 62 , allowing position of waveguide 3 to be stable relative to conductive package 62 . Positional stability of waveguide 3 relative to conductive package 64 facilitates stable optical coupling into waveguide 3 at input port 40 by an input coupling system (not shown) and out of waveguide 3 at output port 50 by an output coupling system (not shown), both input and output coupling systems being in stable position relative to conductive package 62 .
[0047] The structures and functions described with relation to chip 15 could be implemented in chip 2 . However, some of these structures and functions are easier and more economical to implement on an insulator material such as the one of chip 15 than it is on a semiconductor material described in chip 2 . As an example, implementing pre-distortion circuit 22 on chip 15 is more economical than it would be to implement it on chip 2 .
[0048] The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto. | A semiconductor based electro-optic modulator comprising a capacitively coupled ground allowing for DC biasing of the modulator and a pre-distortion circuit for alleviating RF skin effect and for increasing bandwidth of modulator. Electrical components and functions of modulator partly located on an alumina pane. Reduction of thermally-induced stresses by connecting modulator ground to package ground via alumina pane is also disclosed. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to human nail decorations, and more specifically the invention pertains to structure and methods for placement of preformed artificial nails and tips for adherence to human nails.
BACKGROUND OF THE INVENTION
[0002] For various aesthetic reasons, many individuals wish to possess elongated fingernails or fingernails having a more finished or polished appearance. However, some are unable or unwilling to grow their own natural fingernails out to the desired length. Alternately, they may not have the time, skill, or financial wherewithal to maintain or obtain a more finished appearance that may result from well manicured and/or polished nails. As a result, entire industries have developed around the artificial supplementation and enhancement of natural nails. Such enhancements may range from manicuring and polishing of natural fingernails to individually building artificial nails on the natural nail and nail form from an acrylic powder and liquid which chemically bond to the nail surface as the artificial nail is built. Between these two extremes, are preformed, artificial nails that are glued or otherwise bonded to a person's own naturally occurring fingernails. Such nails are readily available to a wide range of users through drug stores, food stores, dollar store and department stores. Such preformed artificial nails may be clear or opaque, and/or prepolished and/or decorated to provide the desired appearance.
[0003] Artificial nails are commonly made from molded thermoplastic and are available in a wide range of lengths and styles. One broad category of an artificial nail style is the full nail form. As its name implies, the full nail form simulates the entire human fingernail and includes a proximate edge intended to overlay substantially the entire nail bed and a distal free edge which is intended to extend beyond the fingertip of the wearer. The proximate edge is shaped to be disposed substantially adjacent or abut against the cuticle of the finger. The distal free edge may have any of various lengths and shapes, such as oval, square, or flared, depending upon the desired look. Preferably, the artificial nail is sufficiently durable and rigid to withstand the hazards inherent in its use.
[0004] In contrast, nail tips do not simulate the complete nail, but, rather, only the free edge and, typically, a small extended portion to cover only a portion of the nail bed in order to facilitate attachment to the nail. In use, nail tips are secured to the edge of the nail bed adjacent the free edge and the tip only. Tips are often utilized with the construction of acrylic nails or gel nails.
[0005] Manufacturers typically provide users with a range of nail sizes, e.g., identified by size numbers 0-9, to accommodate most nail sizes. Generally, artificial nails are packaged together in sets including a range of different sizes so that the purchaser receives differently artificial nails for their different fingers. In addition to the set of different sized artificial nails, the package may also include liquid adhesive, peel-off adhesive pads, and/or preplaced tacky adhesive for bonding the artificial nails to the purchaser's natural fingernails.
[0006] Artificial nails are provided in a variety of lengths ranging from relatively long nails having either a straight profile or arched profile, to relatively short nails, which more closely simulate well groomed natural nails. In placement of the artificial nail on a user's natural nail, the adhesive is typically applied either directly to the user's natural nail bed or to the nail bed portion of the artificial nail. The artificial nail is then placed on the user's natural nail bed with the proximal end of the artificial nail disposed at or near the user's cuticle, and pressure is applied to ensure the desired adhesion of the artificial nail to the user's natural nail. Inasmuch as the adhesive used in placing artificial nails is generally tacky, it is difficult to make adjustments to the position of the artificial nail on the natural nail once initial placement is made. Attempts to reposition the artificial nail relative to the natural nail or to remove and replace the artificial nail may result in either a substandard appearance to the artificial nail, or time consuming additional cleaning of the artificial nail and repetition of the placement process. As a result, it is important that the artificial nail be placed at the desired position on the natural nail at the first attempt so as to avoid the need to remove and reposition the nail.
[0007] Longer artificial nails typically extend well beyond the free edge of the user's natural nails. Consequently, in placing relatively long artificial nails on the user's natural nails, one may generally utilize the extended free edge of the artificial nail to hold the artificial nail prior to placement, and to manipulate and accurately position the artificial nail on the user's nail bed. When utilizing smaller artificial nails, however, the free edge is very short, and does not extend far beyond the user's natural nail or finger tip, if at all. Accordingly, such short nails can be particularly difficult to accurately place on the user's natural nail by simply grasping the artificial nail using one's fingers.
[0008] As a result, manufacturers have proposed various tools to allow for holding and placing artificial nails during application. One such tool comprises an elongated rod with a tacky adhesive pad or tape at the end of the tool to grip the artificial nail, such as the tools shown in U.S. Pat. No. 6,220,250 to Park and the tool marketed by Sally Hansen®. This tacky, adhesive pad, however, has proven unreliable in use, however, inasmuch as the retaining force exerted by the adhesive on the artificial nail typically deteriorates over time such that it does not exert a consistent retaining force on the artificial nail. Moreover, should the adhesive pad become contaminated with dust or the like, it becomes generally useless in that it does not exhibit adequate force to retain a series of nails for placement.
[0009] Another such tool is shaped like a concave shovel with a shorter opposing lip that is disposed parallel to the shovel such that a small slot or gap is formed between the inside surface of the shovel and the lip, as shown in U.S. Pat. No. D441,134 to Manzione and marketed by Uptown Nails, LLC. In use, the outer, arched surface of the artificial nail is disposed against the inside surface of the shovel with the free edge of the artificial nail disposed in the gap between the lip and the shovel. This tool likewise exhibits deficiencies. While the “shovel” tool does not deteriorate with use, it is cumbersome to utilize. Should the gap between the shovel and lip be sufficiently small to exert a retaining force on the artificial nail, the user will typically be required to exert an external downward, retaining force on the artificial nail when it is placed against the natural nail in order to facilitate release of the artificial nail by the tool. Inasmuch as the user's free hand grasps the tool, the user must typically use a different finger from the placement hand to exert a retaining force the placed artificial nail to facilitate release of artificial nail from the tool. Conversely, if the tool does not exert adequate retaining force to hold the artificial nail during the placement process, the tool may allow artificial nail to move within the gap, making accurate placement of the artificial nail against the natural nail significantly more difficult.
[0010] The assignee of the present invention has proposed a tool that utilizes a small suction cup disposed at the distal end of an elongated rod. In applying an artificial nail to a natural nail, the user places the suction cup on the upper surface of the artificial nail and expels any air trapped between the cup and the nail. The user then utilizes the tool to position the artificial nail on the natural nail. The suction cup provides sufficient force to retain the nail during placement, yet that force is overcome by the tackiness of the adhesive or the adhesive bond between the artificial nail and the natural nail once properly placed. Moreover, the retaining force of the tool typically does not deteriorate over time. The tool is disclosed in greater detail in PCT Publication WO06/062963A.
[0011] Manufacturers have likewise proposed severable protrusions that extend from one or more edges of the artificial nail itself. The protrusions are utilized to place the artificial nail and then severed from the nail once proper placement has been achieved. For example, U.S. Pat. No. 6,892,736 to Chinn et al. includes a tab that extends from the distal edge of the nail. A similar arrangement is disclosed in U.S. Pat. No. 5,005,595 to Aylott.
[0012] While nail packaging often times includes single nails displayed in individual display wells or product bubbles, in view of space considerations, artificial nail packaging generally includes a larger well or space that includes a plurality of nails in loose or free configuration. This is generally the case with both artificial nails without application tabs, and artificial nails that include application tabs. Such is the case with nails incorporating aspects of the design disclosed in the '736 patent to Chinn. Nails marketed under the name Broadway Nails—Real Life French Nail Kit include a tab and nail arrangement shaped generally as shown in the '736 patent. The packaging of the Real Life French Nail Kit includes a general well which encloses a plurality of nails together in a loose configuration.
[0013] While nails are sometimes identified by a size number, unfortunately, this loose configuration can make it difficult to locate an artificial nail in a desired size for placement on a nail. This problem can be aggravated in packages where the nails include an application tab, which can cause nails to become further entangled. Possible solutions to this dilemma include the provision of a product bubble for each nail, respectively, or the provision of all such nails of a package attached to a nail tree. Examples of such nail trees are provided in the '736 patent to Chinn, as well as a number of other references. Unfortunately, both of these solutions typically require the use of a larger packaging arrangement than may be utilized when a large product well is used to contain a plurality of loose nails. Such larger packages may be undesirable when display space at a retail establishment is limited or at a premium.
[0014] As a result, it is desirable to provide a nail placement arrangement that overcomes these shortcomings of the prior art to provide for accurate and reliable, repeatable placement of artificial nails. It is further desirable that the arrangement for presentation of such nails in a package is easy to utilize and facilitates location of desired nail sizes, yet does not require presentation of each nail individually or on a single tree.
BRIEF SUMMARY OF THE INVENTION
[0015] The invention provides a nail application tab assembly that extends between a pair of artificial nails, preferably of the same size. The application tab assembly generally includes an area of weakness between the tab assembly and the respective nails to facilitate separation. The assembly also may optionally include an area of weakness within the tab assembly itself such that the tab assembly may be separated into two separate tabs, each secured to a respective artificial nail. In this way, the tab assembly may be kept as a single unit to facilitate placement of the nails, or the assembly may be separate tabs coupled to the respective nails. The weakened area within the tab assembly itself, and/or between the tab assembly and the artificial nails may include, for example, a perforation, an area of reduced thickness, a score line, or a reduced cross-sectional area.
[0016] The tab assembly may be secured to the artificial nails at any appropriate position. Preferably, it is disposed along the distal end of the nail, the body of the application tab assembly extending from the lower surfaces of the nails and/or the distal edges of the nails. Moreover, the tab assembly may be disposed in a relatively horizontal plane, a plane relatively vertical to one or more of the nails, or at any angle therebetween.
[0017] The kit may further include additional items such as an adhesive, a towelette including a cleaner, a roughening surface, a stick, and/or a placement tool.
[0018] These and other objects and advantages of the invention will be apparent to those skilled in the art upon reading the following summary and detailed description and upon reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a perspective view of a kit having exemplary contents, including an artificial nail assembly according to teachings of the invention.
[0020] FIG. 2 is a perspective view of a pair of artificial nails with application tab constructed in accordance with teachings of the invention.
[0021] FIG. 3 is top plan view of the artificial nail assembly of FIG. 2 .
[0022] FIG. 4 is a side elevational view of the artificial nail assembly of FIGS. 2 and 3 .
[0023] FIG. 5 is a perspective view of an alternate embodiment of an artificial nail assembly constructed in accordance with teachings of the invention.
[0024] FIG. 6 is a top plan view of the artificial nail assembly of FIG. 5 .
[0025] FIG. 7 is a side view of the artificial nail assembly of FIGS. 5 and 6 .
[0026] FIGS. 8A and 8B are perspective views of a manner in which the pair of nails may be separated.
[0027] FIG. 9 is a perspective view of an alternate embodiment of a pair of artificial nails constructed in accordance with teachings of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Turning now to the drawings, wherein like reference numbers refer to like elements, there is illustrated in FIG. 1 a nail kit 16 comprising a package 18 containing a plurality of preformed artificial nail assemblies 20 . Each nail assembly 20 comprises an artificial nail 22 which has a proximal end 30 , adapted to be placed generally adjacent the user's cuticle, and a distal end 32 that is generally disposed at or beyond the end of the user's natural nail when properly placed. The area between the proximal and distal ends 30 , 32 of the artificial nail 22 generally defines the nail bed portion 34 and the free edge 36 , the nail bed portion 34 being adapted to be placed adjacent the user's natural nail bed and the free edge 36 being adapted to extend beyond the end of the user's finger. The artificial nails 22 further include right and left side edges 37 , 38 with the nail 22 having a generally arched contour between the side edges 37 , 38 and a generally less arched contour between the proximal and distal edges 31 , 33 .
[0029] The nail kit package 18 typically includes an outer covering 40 , here in the form of a box, having at least one transparent portion 41 for viewing the contents of the package 20 . The package 20 further includes an inner support housing 42 that generally retains the contents of the package 20 in position within the package 20 . The inner support housing is typically formed of a polymeric material. The inner support housing 42 generally includes a plurality of recessed areas 44 , and additional contents of the package 20 may be retained in a rear open portion of the inner support housing 42 .
[0030] In accordance with the invention, the artificial nail assembly includes an application tab assembly 50 secured to a pair of artificial nails 22 A, 22 B, the application tab assembly 50 facilitates placement of an artificial nail 22 A, 22 B on a natural nail (see FIGS. 2-4 ). In order to assist the user in selection and placement of the nails, the artificial nails 22 A, 22 B of the pair are preferably of like size. The application tab assembly 50 includes a body 52 for the user to grasp during placement, and a neck 54 , 56 that extends between the body 52 and the respective nails 22 A, 22 B.
[0031] The neck 54 , 56 attaches the body 52 to the respective nails 22 at their distal ends 32 . The nail tab arrangement may be of any suitable design, however. For example, while the neck 54 may extend from the distal edge 33 , as shown in FIGS. 2-4 , it may alternately extend from the upper or lower surface of the artificial nail 22 or a combination of the distal edge 33 and one or both of the upper or lower surfaces, as explained in greater detail in application Ser. No. 11/739,371, which is incorporated herein in its entirety for everything disclosed therein. As shown in that application, for example, the neck may extend from the lower surface. Such an arrangement is illustrated in FIG. 9 . It will be appreciated by those of skill in the art that when the neck is separated from the nail in such an arrangement, the neck will not leave any sharp edges or points protruding from the distal edge of the nail, and subsequent manicuring, as by filing for example, may be minimized.
[0032] According to a feature of the invention, once appropriately placed, the application tab assembly 50 may be separated from the nail 22 by any appropriate mechanism. For example, the neck 54 , 56 of the application tab assembly 50 may include a weakened area, such as, for example, a relatively small cross-section at the location where the neck 54 , 56 meets the nail 22 A, 22 B, such as is as shown, for example in FIGS. 2-4 , a thinned section substantially adjacent the nail 22 , as shown, for example, at 64 , 66 in FIGS. 5-7 , a perforation, a score line, or any combination of such structures. Examples of such weakened areas are likewise shown in application Ser. No. 11/739,371. While less desirable, those of skill in the art will appreciate that the application tab assembly 50 could alternately be severed from the nail 22 A, 22 B by a tool, such as scissors or a blade.
[0033] An alternate example of an application tab assembly 60 according to teachings of the invention is illustrated in FIGS. 5-7 . It will thus be appreciated by those of skill in the art that the tab assembly may be of any suitable design, so long as it couples a pair of artificial nails. The application tab assembly 60 of this embodiment includes a slight widening of the tab assembly 60 in the central area. Similarly, the application tab assembly 80 may be at any appropriate orientation to the nails 82 . For example, the tab assembly 80 may be disposed at substantially a right angle to the nails 82 , as shown, for example, in FIG. 9 and as discussed in more detailed in application Ser. No. 11/739,371. As similarly shown in FIG. 9 , the tab assembly 80 may attach to the nails 82 along a lower surface of the nail, for example.
[0034] In order to further assist the user in artificial nail choice, at least the body 62 of the application tab assembly 60 may be sufficiently wide to display information for the user. Thus, the tab assembly 60 may include indicia 68 such as, for example, the size number of the accompanying nail, the name of the manufacturer, a trademark or trade name, the nail color or instructions. The indicia 68 may be provided on the application tab assembly 60 by any appropriate mechanism, such as, for example, molding the indicia into the arrangement, or printing the indicia thereupon. In this way, such indicia 68 may facilitate the user's choice of nail for application.
[0035] According to another feature of the invention, the application tab assembly 60 may include an area of weakness 70 which facilitates the separation of the application tab assembly 60 into two separate application tabs 72 , 74 . As with the weakened area 54 , 56 , 64 , 66 , the area of weakness 70 may include, for example, a relatively small cross-section 58 , such as is as shown, for example in FIGS. 2-4 , a thinned section, as shown, for example, at 70 in FIGS. 5-7 , a perforation, a score line, or any combination of such structures. As shown in FIGS. 8A and 8B , the user may separate the application tab assembly 60 into a pair of separate application tabs 72 , 74 , each secured to an artificial nail 22 A, 22 B. Thus, the user has the option of either applying the nails 22 A, 22 B from a position attached to the application tab assembly 50 , 60 as a single unit, or attached respectively to separated tabs 72 , 74 .
[0036] It will be appreciated that the preformed artificial nails 22 utilized in the nail kit 18 may be of any appropriate design. For example, the invention may likewise be utilized in connection with a nail tip, as opposed to a full nail, as illustrated in the figures. Thus, for the purposes of this disclosure and the claims appended hereto, the term “nail” will be used to correspond to both a full nail and a nail tip. Those of skill in the art will appreciate that the nail tip is essentially the same as a full nail with the exception that the nail tip includes only a portion that is adapted to cover only a distal portion of the natural nail. Moreover, the nail kit may include additional items, such as, by way of example only, an appropriate adhesive, such as is shown in FIG. 1 , a rough or emery type surface for buffing the natural nail prior to placement of the artificial nail, a towelette including an acetone or other substance to clean the nail prior to placement, a rosewood stick and/or an application tool for assistance during installation of the artificial nail onto the natural nail surface. Further, the assembly of a pair of artificial with application tab assembly may be fabricated by any appropriate process. By way of example only, the may be injection molded or the like.
[0037] While this invention has been described with an emphasis upon preferred embodiments, variations of the preferred embodiments can be used, and it is intended that the invention can be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications encompassed within the spirit and scope of the invention as defined by the following claims.
[0038] All of the references cited herein, including patents, patent applications, and publications, are hereby incorporated in their entireties by reference. | A preformed artificial nail assembly comprising a pair of artificial nails sized to correspond to at least a portion of said natural nail, and an application tab assembly extending between the pair of artificial nails. The application tab assembly includes a body portion and a neck portion adjacent each said artificial nail, said neck portion being disposed between the body portion and the distal end of the artificial nail. The application tab assembly may include an area of weakness that allows the assembly to be separated into two separate tabs, one adjacent each of the artificial nails of the pair. The user my utilize the application tab assembly as a single unit to place the nails, or separate the assembly into to separate tabs to allow the user to place the nails utilizing separate tabs. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of patent application Ser. No. 10/950,401 filed on 28 Sep. 2004 which is a patent application based upon Provisional Patent Application Ser. No. 60/524,873, entitled “System for Monitoring Cardiovascular Condition” filed provisionally on 26 Nov. 2003.
FIELD OF USE
[0002] This invention is in the field of systems that monitor a patient's cardiovascular condition using implanted devices that interact with other devices located externally to the patient.
BACKGROUND OF THE INVENTION
[0003] Heart disease is the leading cause of death in the United States. A heart attack (also known as an acute myocardial infarction (AMI)) typically results from a thrombus (i.e., a blood clot) that obstructs blood flow in one or more coronary arteries. AMI is a common and life-threatening complication of coronary artery disease. Myocardial ischemia is caused by an insufficiency of oxygen to the heart muscle. Ischemia is typically provoked by physical activity or other causes of increased heart rate when at least one coronary artery is narrowed by atherosclerosis. Patients will often (but not always) experience chest discomfort (angina) when the heart muscle is experiencing ischemia. Those with coronary atherosclerosis are at higher risk for AMI if the plaque becomes further obstructed by thrombus. Those patients who do not have any symptom of ischemia or AMI are said to have “silent ischemia.” These patients are at the highest risk of dying from coronary artery disease.
[0004] The current treatment for a coronary artery narrowing (a stenosis) is the insertion of a drug eluting stent such as the Cypher™. sirolimus-eluting stent from Cordis Corporation or the Taxus™. paclitaxel-eluting stent from the Boston Scientific Corporation. The insertion of a stent into a stenosed coronary artery is the most reliable medical treatment to eliminate or reduce coronary ischemia and to prevent the complete blockage of a coronary artery, which complete blockage results in an AMI.
[0005] Acute myocardial infarction and ischemia may be detected from a patient's electrocardiogram (ECG) by noting an ST segment shift (i.e., voltage change) over a relatively short (less than 5 minutes) period of time after a complete blockage of a coronary artery. However, without knowing the patient's normal (i.e., baseline) ECG pattern, detection from a standard 12 lead ECG can be unreliable.
[0006] Fischell, et al in U.S. Pat. Nos. 6,112,116, 6,272,379 and 6,609,023 describe implantable systems and algorithms for detecting the onset of acute myocardial infarction and providing both treatment and patient alerting. While Fischell, et al discuss the acute detection of a shift in the ST segment of the patient's electrogram from an electrode within the heart as the trigger for alarms, it may be desirable to provide more sophisticated long term tracking of myocardial ischemia to provide early prediction of coronary obstruction before the occurrence of a complete coronary artery blockage that results in an AMI. An important aspect of the Fischell, et al patents is that the heart's electrical signal from inside the patient's body, which is called an “electrogram,” is a more accurate means to discern ischemia as compared to the heart's signal as measured on the patient's skin which is the ECG.
[0007] The Fischell, et al patents as listed above discuss the storage of recorded electrograms and/or electrocardiogram data; however techniques to optimally capture the appropriate statistical electrogram and/or electrocardiogram data over days, weeks and months in a limited amount of system memory are not described.
[0008] The Reveal™. subcutaneous loop Holter monitor sold by Medtronic, Inc. uses two case electrodes spaced about 3 inches apart to record electrogram information. Recording can be triggered automatically when arrhythmias are detected or upon patient initiation using an external device. The Reveal is designed to record electrogram data and does not include the signal processing capability to track changes in the heart signal over an extended period of time. The Reveal also does not have the capability to measure ST segment shift. In fact, its high pass filtering and electrode spacing preclude accurate detection of changes in the low frequency aspects of the heart's electrical signal, which low frequency aspects are required for the detection of ischemia.
[0009] While pacemakers track the numbers of beats paced or not paced and pacemaker programmers can display the beat data in histogram format, pacemakers do not produce histograms of heart signal parameters related to the electrogram wave form. In other words, pacemakers track pacemaker operation but pacemakers do not measure or compute heart signal parameters of the beats in the electrogram signal, nor do they save the computed values of heart signal parameters in memory.
[0010] Pacemakers have been used to collect intramyocardial electrogram (IMEG) data for the purpose of using a decrease in electrogram QRS complex voltage as an indicator of the rejection of a transplanted heart. The expense, patient discomfort and inconvenience of endomyocardial biopsy to detect heart transplant rejection makes an electronic method highly desirable. The published paper “Clinical Heart Transplantation without Routine Endomyocardial Biopsy” by Warnecke, et al in the November/December 1992 issue of The Journal of Heart and Lung Transplantation showed that IMEG recordings made with a cardiac pacemaker have the potential to replace endomyocardial biopsy (EMB) as a diagnostic method to detect transplant rejection. Specifically, Warnecke et al showed that an 8% decline in IMEG voltage provided the best sensitivity and specificity as an indicator of potential acute moderate allograft rejection of a transplanted heart. Unfortunately, pacemakers are not designed to collect weeks or months of statistical data on electrogram voltage variations. The additional external support equipment needed to continually offload the raw electrogram data from a pacemaker is expensive and inconvenient to use..
[0011] The term “medical practitioner” shall be used herein to mean any person who might be involved in the medical treatment of a patient. Such a medical practitioner would include, but is not limited to, a medical doctor (e.g., a general practice physician, an internist or a cardiologist), a medical technician, a paramedic, a nurse or an electrogram analyst. Although the masculine pronouns “he” and “his” are used herein, it should be understood that the patient or medical practitioner could be a man or a woman. A “cardiac event” includes an acute myocardial infarction, ischemia caused by effort (such as exercise) and/or an elevated heart rate, bradycardia, tachycardia or an arrhythmia such as atrial fibrillation, atrial flutter, ventricular fibrillation, premature ventricular contractions or premature atrial contractions (PVCs or PACs) and the rejection of a transplanted heart.
[0012] For the purpose of this invention, the term “electrocardiogram” is defined to be the heart's electrical signal as sensed through skin surface electrodes that are placed in a position to indicate the heart's electrical activity (depolarization and repolarization). An electrocardiogram segment refers to electrocardiogram data for either a specific length of time, such as 10 seconds, or a specific number of heart beats, such as 10 beats. For the purposes of this specification, the PQ segment of a patient's electrocardiogram is the typically flat segment of a beat of an electrocardiogram that occurs just before the Q and R waves. For the purposes of this specification the ST segment of a patient's electrocardiogram is that segment of a beat of an electrocardiogram that occurs just after the S wave.
[0013] Although occasionally described as an electrocardiogram (ECG), the electrical signal from the heart as measured from electrodes within the body is properly termed an “electrogram” or intramyocardial electrogram (IMEG). For the purpose of this invention, the term “electrogram” is defined to be the heart's electrical signal from one or more implanted electrode(s) that are placed in a position to indicate the heart's electrical activity (depolarization and repolarization). An “electrogram segment” refers to a recording of electrogram data for either a specific length of time, such as 10 seconds, or a specific number of heart beats, such as 10 beats. For the purposes of this specification the PQ segment of a patient's electrogram is the typically flat, generally horizontal segment of an electrogram that occurs just before the Q and R waves. For the purposes of this specification the ST segment of a patient's electrogram is that segment of an electrogram that occurs just after the S wave. For the purposes of this specification, the term QRS voltage is defined as a measure of QRS complex voltage amplitude which may either be measured from Q to R, or S to R of a beat of the electrogram. For the purposes of this specification, the term QRS segment or QRS complex is that segment of the electrogram from the Q through the R and ending at the J point of the S wave. For the purposes of this specification, the terms “detection” and “identification” of a cardiac event have the same meaning. A beat is defined as a sub-segment of an electrogram or electrocardiogram segment which covers the electrical signal from the heart for exactly one beat of the heart and includes exactly one R wave. If the heart rate is 60 bpm, then the sub-segment of the electrogram that is exactly one beat would represent a sub-segment of the electrogram that is exactly 1.0 second in duration. For the purposes of this invention, the term “average value”, “average amplitude” or “average voltage” of any segment (viz., QRS complex, ST segment or PQ segment) of the electrogram shall be defined as meaning either the mean or the median of a multiplicity of measurements of that segment. It is also envisioned that in some cases both mean and median may be computed and will on occasion be described separately herein.
[0014] “Heart signal parameters” are defined to be any measured or calculated value created during the processing of one or more beats of electrogram (or electrocardiogram) data. Heart signal parameters are features of the electrogram derived from one or more measured values and include PQ segment average voltage, ST segment average voltage, R wave peak voltage, ST deviation (ST segment average voltage minus PQ segment average voltage), ST shift (ST deviation compared to a baseline average ST deviation taken at some prior time), average signal strength, T wave peak height, T wave average voltage, T wave deviation, QRS complex width, QRS voltage, heart rate and R-R interval. Counts of the number of arrhythmia related events such as PACs, PVCs and/or episodes of atrial fibrillation are not considered herein to be heart signal parameters as they do not directly result from a measured value derived from a beat of the electrogram. ST segment related heart signal parameters include, ST segment average voltage, ST deviation and ST shift.
SUMMARY OF THE INVENTION
[0015] A “tracker system” as defined herein includes implanted electrical leads which are part of an implanted cardiotracker plus external equipment that includes external alarm means and a physician's programmer. The present invention is the tracker system for monitoring the degradation of a patient's cardiovascular condition from one or more causes. These causes include the rejection of a transplanted heart and further include the progression of a stenosis in a coronary artery; e.g., as one or more stenoses in a coronary artery become progressively more narrow thereby causing reduced blood flow to the heart muscle. As less and less blood is available to the heart muscle, the patient's ST segment will shift during exertion by an ever increasing amount. Eventually, if the stenosis severely restricts blood flow or a plaque rupture occurs, a thrombus can form causing an AMI. By noting changes over time in the shift of ST segment voltage in relation to the patient's heart rate, the patient's doctor can identify coronary artery narrowing and intervene before a potentially fatal AMI occurs. The preferred intervention for such narrowing is the implantation of one or more drug eluting stents to restore normal blood flow for the coronary circulation. The tracker system also has the capability for tracking electrogram signal amplitude (e.g., QRS voltage) as well as electrogram feature time durations such as the width of the QRS complex, etc. A decrease in the average value of the QRS voltage as compared to a baseline value for that parameter has been shown to be an early indicator of rejection of a transplanted heart. By careful monitoring of this heart signal parameter, the number of periodic biopsies of heart tissue as an indicator of transplant rejection can be greatly reduced which provides a significant cost savings as well as a reduction in the myocardial scar tissue created by each biopsy.
[0016] As previously stated, the tracker system includes a device called a cardiotracker for processing and recording patient heart electrical signals, a physician's programmer and an external alarm system. In the preferred embodiment of the present invention, the cardiotracker is implanted along with the leads that have electrodes that can sense the heart's electrogram. In an alternative embodiment, the cardiotracker including the electrodes could be external but attached to the patient's body. Although the present invention (as described herein) in most cases refers to the preferred embodiment of an implanted cardiotracker which can process electrogram data from implanted electrodes, the techniques described are equally applicable to an alternative embodiment where an external cardiotracker processes electrocardiogram data from appropriately placed skin surface electrodes.
[0017] In the preferred embodiment of the cardiotracker, either or both subcutaneous electrodes or electrodes located on a pacemaker type right ventricular or atrial leads can be used. It is also envisioned that one or more electrodes may be placed within the superior vena cava or other vessels of the circulatory system. One version of the implanted cardiotracker device using subcutaneous electrodes would have an electrode located under the skin on the patient's left side. This could be best located between 2 and 20 inches below the patient's left arm pit. The cardiotracker case acting as the indifferent electrode would typically be implanted like a pacemaker under the skin on the upper left side of the patient's chest. Still another version of the cardiotracker could utilize epidural electrodes attached externally to the heart. This attachment of epidural electrodes to the exterior surface of the heart from an epidural lead could take place during the surgery for a transplanted heart.
[0018] The physician's programmer is used to program the cardiotracker with respect to any or all of its diagnostic, detection, alarming and alerting functions. The physician's programmer is also used to retrieve and analyze recorded electrogram segments and other processed heart signal data from the cardiotracker memory.
[0019] Such processed heart signal parameter data includes histograms and statistical data that can be used to identify changes in cardiovascular condition over time periods of days, weeks, months or even years. The histogram data can be analyzed by the patient's physician using analysis tools provided in the physician's programmer. The histogram and/or average value data can also be compared against preset thresholds that are programmed into the cardiotracker. If the thresholds are exceeded, the cardiotracker can activate internal and/or external alarm means for alerting the patient to seek medical attention.
[0020] Of particular importance is the ability of the histograms in the cardiotracker to track QRS complex voltage amplitude (or simply the QRS voltage) on a daily basis. While QRS complex peak-to-peak voltage is the preferred measurement used for QRS voltage, other signal amplitudes such as PQ segment to R height or S wave amplitude are also envisioned. A current publication “Clinical Heart Transplantation Without Routine Endomyocardial Biopsy” by Warnecke et al in The Journal of Heart and Lung Transplantation showed that intramyocardial electrogram (IMEG) recordings made with a cardiac pacemaker have the potential to replace endomyocardial biopsy (EMB) as a diagnostic means to detect transplant rejection. Specifically, Warnecke et al showed that an 8% decline in electrogram voltage provided the best sensitivity and specificity as the indicator of potential acute moderate allograft rejection.
[0021] While pacemakers are not designed to collect weeks or months worth of statistical data on electrogram voltage variations, the present invention cardiotracker and tracker system is ideally suited for that purpose. A daily histogram stored in cardiotracker memory which tracks the electrogram voltage for every beat analyzed, (e.g., 3 to 12 beats every 30 seconds) can provide the data needed to identify potential transplant rejection without the need for endomyocardial biopsy. The histogram data would be downloaded to the tracker system's physician's programmer for analysis allowing the medical practitioner to identify a drop in electrogram voltage indicative of transplant rejection. Specifically, a decrease in the average value of a multiplicity of recently measured QRS voltages compared to a baseline QRS voltage taken when the transplanted heart was not being rejected can be used by the cardiotracker to detect the early rejection of a transplanted heart. This detection can also be used to initiate a patient alert warning signal to advise the patient to seek medical attention. By changing medications as to type or amount, the rejection of the heart transplant can be reversed and the patient's life can be saved. It also may be desirable that the cardiotracker or tracker system programmer be capable of calculating the average (i.e., mean or median) and standard deviation of the distribution of the multiplicity of measured QRS voltages captured by a histogram data storage technique. For example a reduction of greater than 8% of the daily mean QRS voltage compared to a baseline value for this parameter could be an important indicator of transplant rejection. It is also envisioned that the average QRS voltage over a preset data collection time period (e.g., a day) could be collected by a cardiotracker without the need for a histogram.
[0022] The cardiotracker histogram capability could also track electrogram segment voltages as a function of heart rate creating two or more histograms per day where each histogram represents the distribution of QRS voltage for every beat in a pre-specified heart rate range. Furthermore, the cardiotracker could be programmed to record the QRS complex voltage only during a limited time period. It may be preferable to select a time period when the patient would normally be sleeping such as from midnight to 5 AM.
[0023] Similar to the cardiosaver device described by Fischell et al in U.S. Pat. Nos. 6,112,116, 6,272,379 and 6,609,023, which are incorporated herein by reference, the cardiotracker can detect an acute change in the patient's electrogram that is indicative of a cardiac event, such as an acute myocardial infarction, within five minutes after it occurs and then automatically warn the patient that the event is occurring. To provide this warning, the tracker system includes an internal alarm sub-system (internal alarm means) within the cardiotracker and/or an external alarm system (external alarm means). In the preferred embodiment, the cardiotracker communicates with the external alarm system using a wireless radio-frequency (RF) signal. It is envisioned that the external alarm system of the tracker system would have capabilities equivalent to those described by Fischell et al in U.S. Pat. Nos. 6,112,116, 6,272,379 and 6,609,023.
[0024] As in the Fischell et al devices as previously described, it is envisioned that there would be at least two types of alarms: a major/critical event alarm (an “EMERGENCY ALARM”) signaling the detection of a major cardiac event (e.g., a heart attack which is an AMI) and the need for immediate medical attention, and a less medically significant alert (a “SEE DOCTOR ALERT” or alarm) signaling the detection of a less serious condition that is not life threatening such as exercise induced ischemia resulting from a stenosis that is limiting blood flow in a coronary artery. Detection of a decreased QRS voltage indicative of the rejection of a transplanted heart could most appropriately be indicated by a SEE DOCTOR ALERT because this is not an emergency situation but rather one which should inform the patient to see a doctor as soon as convenient.
[0025] It is also envisioned that the external alarm system of the tracker system would have capabilities equivalent to that described by Fischell et al in U.S. Pat. Nos. 6,112,116, 6,272,379 and 6,609,023.
[0026] Techniques to capture electrogram data and heart signal parameter data computed from electrograms over days, weeks or months are important because, as discussed above, some of the processes of heart malfunction are gradual and it is desirable to detect and treat such conditions before the onset of an acute event such as an AMI or ventricular fibrillation or the complete rejection of a transplanted heart. Limiting the amount of memory and electrical power needed in the implanted cardiotracker to collect, store and analyze the electrogram data looking for trends is especially important in implantable and portable systems.
[0027] The present invention cardiotracker will compute the value of one or more heart signal parameters for each of a multiplicity of beats of the electrogram. These values will be stored in memory for a first time period which is defined as the “data collection time period.” The cardiotracker would typically store these values of the one or more heart signal parameters for a multiplicity of data collection time periods over a second time period which is defined as the “collected data retention time period.” The cardiotracker would typically compute extracted heart signal parameters (e.g., the mean or median value) extracted from the heart signal parameter values stored in memory during each data collection time period. The cardiotracker would typically store the values of extracted heart signal parameters for a third time period defined as the “extracted data retention time period.” In the preferred embodiment of the present invention, the values of the one or more heart signal parameters stored during the data collection time period would be stored as a histogram or histograms.
[0028] The present invention cardiotracker can track any combination of the following heart signal parameters:
[0029] 1. ST segment voltage
[0030] 2. ST deviation (ST segment amplitude—PQ segment amplitude for a single heart beat),
[0031] 3. R-R interval (time period between successive R waves),
[0032] 4. R-R interval variability,
[0033] 5. R peak height,
[0034] 6. R wave width
[0035] 7. QRS voltage,
[0036] 8. QRS width,
[0037] 9. RS width,
[0038] 10. T wave width and/or amplitude,
[0039] 11. T wave alternans, and
[0040] 12. QRS shift (a recent average value of QRS voltage over a data collection time period minus the baseline QRS voltage where baseline QRS voltage is the average value of the QRS voltage for a multiplicity of heart beats at a time when the heart of a heart transplant patient is not undergoing rejection)
[0041] The present invention cardiotracker can also count arrhythmia related events (that are not heart signal parameters) including:
[0042] a) incidence of PACs or PVCs
[0043] b) PVC beats per electrogram segment,
[0044] c) occurrences of two consecutive beats that each have a PVC,
[0045] d) the incidence and duration of episodes of ventricular tachycardia,
[0046] e) occurrences of three consecutive PVCs and/or
[0047] f) the incidence and time duration of episodes of atrial fibrillation.
[0048] Some of these data will be predictive of ventricular fibrillation. For example, if there is a change in the frequency of beats with a heart signal parameter that is indicative of a forthcoming episode of ventricular fibrillation, then certain medication may be prescribed or an implantable cardioverter defibrillator (ICD) could be implanted.
[0049] In one preferred embodiment of the present invention cardiotracker, the above mentioned heart signal parameters and/or counts of arrhythmia related events are tracked using a histogram technique.
[0050] The dictionary defines a histogram as a “representation of a frequency distribution by means of rectangles whose widths represent class intervals and whose areas are proportional to the corresponding frequencies”. The present invention cardiotracker is designed to create histograms to track the frequency distribution of beats (number of beats in a preset time period) having heart signal parameter levels within a multiplicity of pre-specified ranges (class intervals). Such a histogram could be displayed by the physician's programmer as a bar chart (a collection of rectangles) where the width of each bar represents a single pre-specified range (class interval) of a heart signal parameter and the area of the bar (height.times.width) is proportional to the number of beats (corresponding frequency) in that range of the heart signal parameter. The preferred embodiment of the present invention uses a uniform width (pre-specified range) for each bar and has the height of the bar equal to the number of beats in the data collection time period having that one heart signal parameter within that pre-specified range. As an example, in the heart rate range of 50 to 80 beats per minute (bpm), the height of a particular bar could indicate that in the data collection time period of 24 hours, there were 3,005 beats having a measurement of QRS voltage between 96% and 98% of the baseline QRS voltage that was measured during a period of 24 hours at 10 days after the heart transplant surgery when biopsy showed no indications of rejection. In a preferred embodiment of the present invention the QRS voltage range of 96% to 98% of baseline would also be expressed as the percent deviation from baseline QRS voltage of −4% to −2%.
[0051] The histograms of the present invention can be used to aid the medical practitioner in determining if a patient is developing a potentially dangerous heart condition. As far as the detection of ischemia (including detection of AMI) is concerned, the tracker system as described herein could accurately be called an “Ischemia Management System” or IMS. The use of such histograms will be clarified with the assistance of FIGS. 6A , 6 B, 7 A and 7 B as provided below in the DETAILED DESCRIPTION OF THE INVENTION.
[0052] In addition, the present invention cardiotracker could provide a set of histograms where each histogram represents a range of a first heart signal parameter and the class intervals of each histogram represent pre-specified ranges of a second heart signal parameter. For example, a first heart signal parameter would be the R-R interval for the beat and the second heart signal parameter would be the ST deviation. It is also envisioned that the cardiotracker would contain a multiplicity of histogram sets where each set would represent the data collected from a different time period (e.g., if the data collection time period is a day, then 7 sets are needed for a week and that week would be the collected data retention time period).
[0053] Furthermore, the implanted cardiotracker can process the histogram(s) to compute extracted histogram data such as:
[0054] 1. the median ST deviation for each histogram,
[0055] 2. the histogram bin having the highest value for a specific parameter,
[0056] 3. The mean value of ST deviation for each histogram,
[0057] 4. the standard deviation of the histogram distribution with respect to the highest value bin or with respect to the mean or median,
[0058] 5. The number of beats per day per histogram exceeding a pre-specified threshold of ST deviation,
[0059] 6. The moving average over two or more data collection time periods of any of items 1 through 5,
[0060] 7. The median of the QRS or RS width histogram, and
[0061] 8. The average (mean and/or median) QRS voltage over a pre-specified time period and/or within a certain range of heart beats per minute.
[0062] 9. The QRS shift which is the average QRS voltage over a data collection time period compared to the baseline QRS voltage. QRS shift is typically the average QRS voltage given as a percentage deviation from the baseline QRS voltage.
[0063] If number 5 above is used, suggested values for each pre-specified ST deviation histogram threshold could be calculated by the programmer based on previously collected histogram data.
[0064] The extracted histogram data can then be compared by the cardiotracker with a detection threshold. If the threshold is exceeded, the cardiotracker can take one or more actions including alerting the patient by means of a SEE DOCTOR ALERT. It is also envisioned that the cardiotracker could compare changes in extracted data between two time periods to detect a change that warrants alerting the patient.
[0065] Examples of use of these histograms for the present invention are as follows:
[0066] 1. For each beat it processes, the cardiotracker would typically compute three heart signal parameters, the ST deviation (i.e., average ST segment signal level minus average PQ segment signal level), the QRS voltage and the R-R interval which is the time between heart beats whose inverse is a measure of heart rate. The QRS voltage might be computed only during a programmed period each day (e.g., during sleep) while the ST deviation would typically be monitored all the time.
[0067] 2. a. The cardiotracker memory would have a current section containing a set of five ST deviation histograms, where each of the five histograms corresponds to a different range of heart rate (i.e., five different R-R intervals). Each ST deviation histogram has (for example) 25 bins where each bin acts as a counter for the number of beats having an ST deviation within a specific range. That specified range has previously been termed the “class interval”. An example of the specific range or class interval for ST deviation might be between −7.5% and −2.5% of the amplitude of the average baseline ST deviation taken at approximately the same time on the prior day
[0068] b. The cardiotracker memory would also have a current section containing two or three QRS voltage histograms, where each of the QRS voltage histograms corresponds to a different range of heart rates (i.e., different R-R intervals). Each QRS voltage histogram has (for example) 25 bins where each bin acts as a counter for the number of beats having a QRS voltage within a specific range.
[0069] 3. The value of the R-R interval computed in (1) above will be used by the cardiotracker to select one of the five ST deviation histograms (2a) into which the ST deviation data for the beat is placed, and one of the QRS voltage histograms (2b) into which the QRS voltage data for the beat is placed. That is, an R-R interval of 1.0 second corresponds to a heart rate of 60 bpm. Therefore, if the R-R interval is 1.0 second, data on a particular heart signal parameter would be placed in that specific histogram for heart rates between 50 and 80 bpm.
[0070] 4. The value of ST deviation computed in (1) above will then be used to pick and increment by one, one of the bins within the selected ST deviation histogram where the value of ST deviation of the beat lies within the range of ST deviation associated with that specific bin. The value of QRS voltage computed in (1) above will then be used to pick and increment by one, one bin within the selected QRS voltage histogram where the value of QRS voltage of the beat lies within the range of QRS voltage associated with that specific bin.
[0071] It is also envisioned that instead of a single histogram per data collection time period, there might be a set of histograms allowing the cardiotracker to track the first heart signal parameter (e.g., those listed above) for different ranges of a second heart signal parameter. For example, QRS voltage might be tracked in a set of three different histograms where each of the three histograms in the set corresponds to a different range of R-R interval or heart rate. Furthermore, these data can be tracked where each histogram (or histogram set) represents a time period as short as a minute to as long as several years. Similarly, many histograms or histogram sets corresponding to successive data collection time periods may be stored in the cardiotracker and/or programmer to allow the physician to follow the long term cardiovascular condition of the patient.
[0072] In a preferred embodiment of the present invention, a multiplicity of histogram sets would track the frequency distribution of beats with respect to two heart rate parameters where each set would correspond to one day. Eight sets would be contained in memory to provide one set for the current day and seven sets corresponding to the previous seven days.
[0073] Additional memory for extracted histogram data would hold basic and/or processed extracted data for each histogram in each set for each day for as long as a year. This provides tremendous data compression. For example, with only 2 kilobytes of memory, the cardiotracker memory could store any of the following types and amounts of data:
[0074] 1. 10 seconds of electrogram data at 200 samples per second, or
[0075] 2. 8 days of histogram data in 5 different heart rate ranges with 25 bins per histogram, or
[0076] 3. 6 months of the average value of a heart signal parameter (viz., the average value of the QRS voltage within a particular range of heart rates)., and number of beats in each day's histograms from (2) above.
[0077] For the purpose of this disclosure, the term “data collection time period” is defined as the time during which the cardiotracker will be updating a histogram or histogram set. The data collection time period could be as short as a minute and as long as many months. Ideally, collection on a daily basis would provide important information and would minimize effects from daily cycles. A data collection time period of less than an hour would be useful to collect ST deviation vs. heart rate data during a stress test in the doctor's office. The data collected during such a stress test could be compared to earlier stress tests using analysis tools built into the physician's programmer of the tracker system. In this way the doctor could detect an increased level of coronary ischemia which may be caused by progressive narrowing of one or more coronary arteries.
[0078] The “collected data retention time period” is hereby defined as the time period over which a histogram or histogram set is stored in cardiotracker memory before it is overwritten with new data. For example if the data collection time period is one day and there are 8 sections of histogram memory (each corresponding to a day), then one section will be the current day with histogram stored from the 7 previous days thus the collected data retention time period is 7 days. The “extracted data retention time period” is similarly defined as the time period over which the extracted histogram data is stored in cardiotracker memory before it is overwritten with new data. For example, if the extracted histogram data (median ST deviation and number of counts) are extracted at the end of each day from that day's histogram, and each day's value of extracted data is stored in cardiotracker memory for 6 months before it is overwritten with new data, then the extracted data retention time period is 6 months.
[0079] Important aspects of the present invention are the techniques used by the physician's programmer to display the collected histogram data to allow a physician to clearly see trends in his patient's cardiovascular condition. These displays include:
[0080] 1. a screen including bar charts separately showing each of the histograms in a set of histograms for one or more data collection time periods (e.g., one or more days). For example, the five ST deviation histograms corresponding to five different heart rate ranges form a set of histograms and QRS voltage histograms for two or three different heart rate ranges form a set of QRS voltage histograms,
[0081] 2. a screen that shows line graphs combining all of the histograms in a set of histograms for one or more data collection time periods where each histogram in the set is represented by a different line, Each line being either a different pattern (e.g. solid line, dashed line, dotted line, etc.) or a different color for a line.
[0082] 3. a screen including the line graphs of item 2 for more than one data collection time period where a typical data collection time period is one day, and
[0083] 4. a screen including a line graph of one or more types of extracted histogram data as a function of time (e.g., the QRS shift) plotted each day for a period of 6 months where the 6 months is the extracted data retention time period).
[0084] The physician's programmer would also be used by the physician to define or select the heart signal parameters that will be tracked using the histogram technique. It is also envisioned that the physician's programmer will be able to process the histogram data downloaded from the patient's cardiotracker to suggest detection thresholds for the detection by the cardiotracker of future cardiac events that warrant patient alerting or alarming.
[0085] An important part of the concept of the present invention is the comparison of a recent value for some heart signal parameter with a baseline value for that parameter that was measured at a prior time. The baseline value would typically be an average value of the heart signal parameter collected over a pre-specified period of time, e.g., the data collection time period.
[0086] For example, while it is envisioned that the cardiotracker might measure the QRS voltage for each beat and use the actual measured QRS voltage values to populate QRS voltage histograms, a preferred embodiment of the present invention would track the QRS voltage for each beat as a percentage of baseline QRS voltage or preferably as the percent deviation (change) from the baseline QRS voltage. In a preferred embodiment of the present invention, the histograms would therefore track the percentage deviation from baseline QRS voltage. Similarly, the average QRS voltage for each data collection time period would be tracked as a percentage deviation from the baseline QRS voltage. Average QRS voltage for each data collection time period is an example of extracted histogram data that would be stored in the extracted histogram data memory of the cardiotracker. For example, the cardiotracker could calculate the baseline QRS voltage being the average value of the QRS voltage for one day at a time after a heart was transplanted into a human subject when traditional medical testing showed that the heart is not being rejected. This would serve as the “baseline QRS voltage” against which all future QRS voltage measurements would be compared. The useful concept here being that a significant decline of the current QRS voltage compared to the baseline QRS voltage would indicate that the transplanted heart is being rejected.
[0087] For example, each day after the baseline QRS voltage is obtained, the value of the day's average QRS voltage (either as measured or as a percent deviation from the baseline QRS voltage) would be placed in the computer memory of the cardiotracker. This would be the “recent” average QRS voltage. The cardiotracker would be designed to detect transplant rejection when the deviation between the recent average QRS voltage compared to the baseline QRS voltage exceeds a preset threshold. Thus, if the recent daily average QRS voltage was less than the baseline QRS voltage by more than (let us say) 8%, the cardiotracker would detect rejection. If enabled, the patient alerting function of the cardiotracker would then initiate a SEE DOCTOR ALERT to be triggered from either or both an internal alarm means and/or an external alarm means. This alarm would alert the patient to seek medical attention in a timely manner, hopefully, to save the patient's life.
[0088] While it may be sufficient to detect transplant rejection when the deviation of average daily QRS voltage as compared to the baseline QRS voltage exceeds a preset threshold for a single day, it may be more reliable to require that the threshold be exceeded for two or more sequential days.
[0089] Thus it is an object of this invention is to have a tracker system including a cardiotracker designed to track slow changes in the condition of the patient's heart.
[0090] Another object of the present invention is to have a tracker system including a cardiotracker designed to track one or more heart signal parameters through the use of stored histograms.
[0091] Still another object of the present invention is to have a cardiotracker capable of comparing basic or processed extracted histogram data with a physician-set threshold and alerting the patient when that threshold is crossed.
[0092] Still another object of the present invention is to have a cardiotracker that can calculate a moving average of extracted histogram data over relevant time periods and use the moving average to track the condition of the patient's heart.
[0093] Still another object of the present invention is to have the physician's programmer process downloaded histogram and extracted histogram data from the cardiotracker to suggest detection thresholds for acute cardiac event detection by the cardiotracker.
[0094] Still another object of the present invention is to have the cardiotracker determine average values for QRS voltage over a data collection time period and also have the capability to provide a SEE DOCTOR ALERT if that average value of the QRS voltage deviates from a baseline QRS voltage by more than a preset amount for one or more sequential data collection time periods.
[0095] Yet another object of the present invention is to have a cardiotracker store QRS voltage as a percentage of the baseline QRS voltage.
[0096] Yet another object of the present invention is to have a cardiotracker store QRS voltage as a percentage deviation from the baseline QRS voltage.
[0097] Yet another object of the present invention is to have a cardiotracker compute the average QRS voltage over a data collection time period as a percentage deviation from the baseline QRS voltage, which percentage deviation is the QRS shift.
[0098] These and other objects and advantages of this invention will become obvious to a person of ordinary skill in this art upon reading of the detailed description of this invention including the associated drawings as presented herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0099] FIG. 1 illustrates a tracker system for the detection of a cardiac event and for warning the patient that a cardiac event is occurring.
[0100] FIG. 2 is a plan view of an implantable cardiotracker showing the cardiotracker electronics module and two electrical leads each having one electrode.
[0101] FIG. 3 is a block diagram of the cardiotracker.
[0102] FIG. 4 illustrates a normal electrogram pattern with a set of typical heart signal parameters.
[0103] FIG. 5 is a block diagram showing the structure of the histogram data memory.
[0104] FIG. 6A is an example of a programmer display screen showing a set of histograms for ST deviation for a single data collection time period (viz., one day), where each histogram corresponds to a different heart rate range.
[0105] FIG. 6B is an example of a programmer display screen showing a set of histograms for the percent deviation of the QRS voltage from a baseline QRS voltage for a single data collection time period (viz., one day), where each histogram corresponds to a different heart rate range.
[0106] FIG. 7A is an example of a programmer display screen showing ST deviation histograms for three different days, where each frequency plot shows 5 different heart rate ranges on one graph with multiple lines.
[0107] FIG. 7B is an example of a programmer display screen showing histograms for the percent deviation of the QRS voltage from the baseline QRS voltage for three specific days and for three different ranges of heart rate.
[0108] FIG. 8A is an example of the programmer display screen showing a graphical representation of the 5 day moving average of the daily average ST deviation for each of five heart rate ranges over a period of 26 weeks.
[0109] FIG. 8B is an example of the programmer display screen showing a graphical representation of the percent deviation of the daily median QRS voltage from the baseline QRS voltage for each of three heart rate ranges over a period of 26 weeks.
DETAILED DESCRIPTION OF THE INVENTION
[0110] FIG. 1 illustrates an example of a tracker system 10 including an implanted cardiotracker 5 and external equipment 7 . The cardiotracker 5 includes electrical wire leads 12 and 15 and a battery-powered electronics module contained within a metal case 11 . The cardiotracker 5 can track the patient's cardiovascular condition over extended periods of time. The cardiotracker 5 can also detect acute cardiac events including acute myocardial infarction and arrhythmias and warn the patient when such an event occurs. The cardiotracker 5 can also track slowly changing cardiac functions such as day-to-day changes in QRS voltage that can be indicative of the rejection of a transplanted heart. The cardiotracker 5 can record the patient's electrogram signal for later review by a medical practitioner. The cardiotracker 5 can capture histogram-based historical representations of one or more heart signal parameters for later analysis and review by a medical practitioner. The cardiotracker 5 can also send out wireless signals 53 to and receive wireless signals 54 from the external equipment 7 . The functioning of the cardiotracker 5 will be explained in greater detail with the assistance of FIGS. 2 , 3 , 4 and 5 .
[0111] The cardiotracker 5 has two leads 12 and 15 that have one or more electrical conductors (wires) with surrounding insulation. The lead 12 is shown with two electrodes 13 and 14 . The lead 15 has subcutaneous electrodes 16 and 17 . In fact, the cardiotracker 5 could utilize as few as one lead or as many as three and each lead could have as few as one electrode or as many as eight electrodes. Furthermore, electrodes 8 and 9 could be placed on the outer surface of the case 11 without any wire leads extending from the cardiotracker 5 .
[0112] The lead 12 in FIG. 1 could advantageously be placed through the patient's vascular system with the electrode 14 being placed into the apex of the right ventricle. The lead 12 with electrode 13 could be placed in the right ventricle or right atrium or the superior vena cava similar to the placement of leads for pacemakers and implantable cardioverter defibrillators (ICDs). The metal case 11 of the cardiotracker 5 could serve as an indifferent electrode with either or both electrodes 13 and/or 14 being active electrodes. It is also conceived that the electrodes 13 and 14 could be used as bipolar electrodes. Alternately, the lead 12 in FIG. 1 could advantageously be placed through the patient's vascular system with the electrode 14 being placed into the apex of the left ventricle. The electrode 13 could be placed in the left atrium.
[0113] The lead 15 could advantageously be placed subcutaneously at any location where the electrodes 16 and/or 17 would provide a good electrogram signal indicative of the electrical activity of the heart. Again for this lead 15 , the case 11 of the cardiotracker 5 could be an indifferent electrode and the electrodes 16 and/or 17 could be active electrodes or electrodes 16 and 17 could function together as bipolar electrodes. The cardiotracker 5 could operate with only one lead and as few as one active electrode with the case 11 of the cardiotracker 5 being an indifferent electrode. The tracker system 10 described herein can readily operate with only two electrodes. It is also envisioned that the lead 15 could be an epicardial lead with the electrode 17 being firmly attached to the heart muscle from outside of the patient's heart and the electrode 13 being implanted elsewhere within the patient's body.
[0114] One embodiment of the cardiotracker device 5 using subcutaneous lead 15 would have the electrode 17 located under the skin on the patient's left side. This could be best located between 2 and 20 inches below the patient's left arm pit. The cardiotracker case 11 could act as the indifferent electrode and would typically be implanted under the skin on the upper left side of the patient's chest. Alternately, both electrodes 8 and 9 could, like the Medtronic Reveal™., be located on the surface of the cardiotracker case 11 .
[0115] FIG. 1 also shows the external equipment 7 that consists of a physician's programmer 68 having an antenna 70 and an external alarm system 60 including a charger 166 that could be used to charge a rechargeable battery (not shown) in the external alarm system 60 . It should be understood that the external alarm system 60 could also be powered by a conventional (i.e., non-rechargeable) battery. The external equipment 7 provides means to interact with the implanted cardiotracker 5 . These interactions include programming the cardiotracker 5 , retrieving data collected by the cardiotracker 5 and handling alarms generated by the cardiotracker 5 .
[0116] The purpose of the physician's programmer 68 shown in FIG. 1 is to set and/or change the operating parameters of the implantable cardiotracker 5 and to read out data stored in the memory of the cardiotracker 5 such as stored electrogram segments, histograms and extracted histogram data. This would be accomplished by transmission of a wireless signal 54 from the programmer 68 to the cardiotracker 5 and receiving of telemetry by the wireless signal 53 from the cardiotracker 5 to the programmer 68 . When a laptop computer is used as the physician's programmer 68 , it would require connection to a wireless transceiver for communicating with the cardiotracker 5 . Such a transceiver could be connected via a standard interface such as a USB, serial or parallel port or it could be inserted into the laptop's PCMCIA card slot. The screen on the laptop physician's programmer 68 would be used to provide guidance to the medical practitioner in communicating with the cardiotracker 5 . Also, the screen could be used to display both real time and stored electrograms that are read out from the cardiotracker 5 as well as histograms and extracted data based on any one of several heart signal parameters.
[0117] In FIG. 1 , the external alarm system 60 has a patient operated initiator 55 , an alarm disable button 59 , a panic button 52 , an alarm transceiver 56 , a speaker 57 , a modem 165 and an antenna 161 . The modem 165 allows data transmission to and from medical services 67 via the communication link 65 . It is also envisioned (but not shown in FIG. 1 ) that the external alarm system 60 could include a microphone and associated electronics for two-way voice communication with the medical services 67 .
[0118] If a cardiac event is detected by the cardiotracker 5 or the long term cardiovascular tracked data has exceeded a programmed limit, an alarm message is sent by a wireless signal 53 to the alarm transceiver 56 via the antenna 161 . When the alarm message is received by the alarm transceiver 56 , a signal 58 is then sent to the loudspeaker 57 . The signal 58 will cause the loudspeaker 57 to emit an external audio alarm signal 51 to warn the patient that an event has occurred. Examples of external alarm signals 51 include a periodic buzzing, a sequence of tones and/or a speech message that instructs the patient as to what is happening and what actions should be taken. Furthermore, the alarm transceiver 56 can, depending upon the nature of the signal 53 , can send an outgoing signal over the link 65 to contact emergency medical services 67 . When the detection of an acute myocardial infarction or other life threatening cardiac event (e.g., tachycardia) is the cause of the alarm, the alarm transceiver 56 could automatically notify medical services 67 that a serious cardiac event has occurred and an ambulance could be sent to treat the patient and to bring him to a hospital emergency room or directly to a catheterization laboratory.
[0119] If communication with medical services 67 is enabled and a cardiac event alarm is sent within the signal 53 , the modem 165 will establish the data communications link 65 over which a message will be transmitted to the medical services 67 . The message sent over the link 65 may include any one, a combination of several or all of the following information types: (1) a specific patient is having an acute myocardial infarction or other cardiac event, (2) the patient's name, address and a brief medical history, (3) a map and/or directions to where the patient is located (using the GPS satellite or cellular location means is also envisioned), (4) the patient's stored electrogram including baseline electrogram data and the specific electrogram segment that generated the alarm (5) continuous real time electrogram data, and (6) a prescription written by the patient's personal physician as to the type of treatment and/or the amount of drug to be administered to the patient in the event of a specific cardiac event. If the medical services 67 include an emergency room at a hospital, information can be transmitted that the patient has had a cardiac event and should be on his way to the emergency room. In this manner the medical practitioners at the emergency room and/or a catheterization laboratory could be prepared for the patient's arrival.
[0120] Just as the ONSTAR™. service will respond to help a driver immediately after a car's air bags deploy, so might the medical services 67 respond to the patient upon receipt of information that a serious cardiac event has occurred. Such a serious cardiac event would cause an EMERGENCY ALARM signal to be initiated by the internal alarm means in the cardiotracker and (if within range) an external alarm would sound from the external alarm system 60 . Based on the patient's cardiac event and prior instructions from the patient's physician, the medical services personnel can instruct the patient and summon appropriate help.
[0121] The purpose of the patient operated initiator 55 is to give the patient the capability for initiating transmission of captured electrogram segments and histogram data from the cardiotracker 5 , through the external alarm system 60 , to a medical practitioner at the medical services 67 . This will enable one or more electrogram segments to be displayed for a medical practitioner. The alarm disable button 59 can be used by the patient to turn off the internal alarm signal generated within the cardiotracker 5 and/or turn off the external alarm signal 51 played through the speaker 57 . If the alarm disable button is not pressed, either or both the internal and external alarms would continue for a preset period of time such as 15 minutes. A reminder alarm signal might then be triggered at some later time (e.g., 2 to 5 hours later) if the patient has not turned off the alarms by means of the alarm disable button 59 .
[0122] The patient might press the panic button 52 in the event that the patient feels that he is experiencing a cardiac event even if there is no alarm signal from either the internal or external alarm means. The panic button 52 will initiate the transmission from the cardiotracker 5 to the external alarm system 60 via the wireless signal 53 of both recent and baseline electrogram segments. Also, following the use of the panic button 52 , the tracker system 10 can be programmed to transmit the last set of histograms tracking a particular aspect of the patient's cardiovascular condition. In addition, an analysis of the histogram data, for example, the 5 day moving average of a heart signal parameter (e.g., ST deviation) over the last week or month, may be transmitted to medical practitioners at the medical services 67 to allow them to see trends in the patient's cardiovascular condition. The external alarm system 60 will then retransmit these data via the link 65 to medical services 67 where a medical practitioner will view the data. The medical practitioner remotely located at the medical services 67 could then analyze the data and call the patient back to offer advice as to whether this is an emergency situation or the situation could be routinely handled by the patient's personal physician at some later time.
[0123] FIG. 2 is a plan view of the cardiotracker 5 having a metal case 11 and a plastic header 20 . The case 11 contains the battery 22 and the electronics module 18 . This type of package is well known for pacemakers, implantable defibrillators and implantable tissue stimulators. Electrical conductors placed through the plastic header 20 connect the electronics module 18 to the electrical leads 12 and 15 , which have respectively electrodes 14 and 17 . The lead electrodes 13 and 16 and the on-case electrodes 8 and 9 of FIG. 1 are not shown in FIG. 2 . It should also be understood that the cardiosaver 5 can function with only two electrodes, one of which could be the case 11 . All the different configurations for electrodes shown in FIGS. 1 and 2 , such as the electrodes 8 , 9 , 13 , 14 , 16 or the metal case 11 are shown only to indicate that there are a variety of possible electrode arrangements that can be used with the cardiosaver 5 .
[0124] On the metal case 11 , a conducting disc 31 mounted onto an insulating disc 32 can be used to provide a subcutaneous electrical tickle to warn the patient with a SEE DOCTOR ALERT or an EMERGENCY ALARM or the disc 31 could act as an independent electrode for sensing the patient's electrogram. Alternatively, the electrode 8 or the electrode 9 of FIG. 1 could be used as a sensing electrode for the electrogram.
[0125] FIG. 3 is a block diagram of the cardiotracker 5 with battery 22 . The electrodes 14 and 17 connect with wires within the leads 12 and 15 respectively to the amplifier 36 that is also connected to the case 11 acting as an indifferent electrode. As two or more electrodes 14 and 17 are shown here, the amplifier 36 would be a multi-channel amplifier. If only one electrode was used, the amplifier would be a single channel amplifier. The amplified electrogram signals 37 from the amplifier 36 are converted to digital signals 38 by the analog-to-digital converter 41 . The digital electrogram signals 38 are buffered in the First-In-First-Out (FIFO) memory 42 . A processor shown as the central processing unit (CPU) 44 coupled to memory means shown as the Random Access Memory (RAM) 47 can process the digital electrogram data 38 stored within the FIFO 42 according to the programming instructions stored in the program memory 45 . This programming (i.e., software) enables the cardiotracker 5 to detect the occurrence of cardiac events such as an acute myocardial infarction.
[0126] A clock/timing sub-system 49 provides the means for timing specific activities of the cardiotracker 5 including the absolute or relative time stamping of detected cardiac events. The clock/timing sub-system 49 can also facilitate power savings by causing components of the cardiotracker 5 to go into a low power standby mode in between times of electrogram signal collection and processing. Such cycled power savings techniques are often used in implantable pacemakers and defibrillators. In an alternative embodiment, the function of the clock/timing sub-system 49 can be provided by a program subroutine run by the central processing unit 44 .
[0127] In a preferred embodiment of the present invention, the RAM 47 includes specific memory locations for 3 sets of electrogram segment storage. These are the recent electrogram storage 472 that would store the last 2 minutes to 24 hours of recorded electrogram segments so that the electrogram data for the last day (even if there are no events) or in the period just before the onset of a cardiac event can be reviewed at a later time by the patient's physician using the physician's programmer 68 of FIG. 1 . For example, the recent electrogram memory 472 might contain eight, 10 second long electrogram segments that were captured every 30 seconds over the prior 4 minute time period. The baseline electrogram memory 474 would also provide storage for baseline electrogram segments collected at preset times over one or more days. For example, the baseline electrogram memory 474 might contain 24 baseline electrogram segments of 10 seconds duration, one from each hour for the prior 24 hours.
[0128] The event memory 476 occupies the largest part of the RAM 47 . The event memory 476 is not overwritten on a regular schedule as are the current electrogram memory 472 and baseline electrogram memory 474 but is typically maintained until read out by the patient's physician with the programmer 68 of FIG. 1 . When a cardiac event such as excessive ST shift indicating an acute myocardial infarction is detected by the CPU 44 , all (or part) of the entire contents of the baseline and recent electrogram memories 472 and 474 would typically be copied into the event memory 476 so as to save the pre-event data for later physician review. Following the occurrence of a cardiac event, post event electrogram data would be saved in the event memory 476 for a preset time period.
[0129] The RAM 47 also contains memory sections for programmable parameters 471 and calculated baseline data 475 . The programmable parameters 471 include the upper and lower limits for the normal and elevated heart rate ranges and physician programmed parameters related to the cardiac event detection processes stored in the program memory 45 . The calculated baseline data 475 contain detection parameters extracted from the baseline electrogram segments stored in the baseline electrogram memory 474 . Calculated baseline data 475 and programmable parameters 471 would typically be saved to the event memory 476 following the detection of a cardiac event. The RAM 47 also includes patient data 473 that may include the patient's name, address, telephone number, medical history, insurance information, doctor's name, and specific prescriptions for different treatments or medications to be administered by medical practitioners in the event of different cardiac events.
[0130] Finally, the RAM 47 contains histogram data memory 43 whose structure is shown in FIG. 5 .
[0131] It is envisioned that the cardiotracker 5 could also contain pacemaker circuitry 170 and/or defibrillator circuitry 180 similar to the cardiosaver device described by Fischell et al in U.S. Pat. No. 6,240,049.
[0132] The alarm sub-system 48 is the internal alarm means that contains the circuitry and transducers to produce the internal alarm signals for the cardiotracker 5 . The internal alarm signal can be a mechanical vibration, a sound or a subcutaneous electrical tickle.
[0133] The telemetry sub-system 46 with antenna 35 provides the cardiotracker 5 the means for two-way wireless communication to and from the external equipment 7 of FIG. 1 . The outgoing signal 53 being from the cardiotracker 5 to the external equipment 7 and the incoming signal 54 being from the external equipment 7 to the cardiotracker 5 . Existing radiofrequency transceiver chip sets such as the CHIPCOM CC1000 or the Ash transceiver hybrids produced by RF Microdevices, Inc. can readily provide such two-way wireless communication over a distance of up to 10 meters from the patient. It is also envisioned that short range telemetry (less than 6 inches) such as that typically used in pacemakers and defibrillators could also be applied to the cardiotracker 5 . It is also envisioned that standard wireless protocols such as Bluetooth and 802.11a, 802.11b or 802.11g might be used to allow communication with a wider group of externally located peripheral devices.
[0134] A magnet sensor 190 could be incorporated into the cardiotracker 5 . An important use of the magnet sensor 190 is to turn on the cardiotracker 5 on just before programming and implantation into a human subject. This would reduce wasted battery life in the period between the times that the cardiotracker 5 is packaged at the factory until the time that it is implanted into the human subject.
[0135] FIG. 4 highlights the features of one normal beat 500 of an electrogram segment and also shows some portions of the prior beat. The beat 500 shows typical heart beat wave elements labeled P, Q, R, S and T. The beat 500 is defined to be a sub-segment of an electrogram segment containing exactly one R wave and including the P and Q elements before the R wave and the S and T elements following the R wave. The R-R interval 507 for the beat 500 is defined as the time from the R wave before the beat 500 to the R wave of the beat 500 . Both the prior R wave and the R wave of the beat 500 are shown in FIG. 4 .
[0136] For the purposes of detection algorithms, different sub-segments, elements and calculated values related to the beat 500 are hereby specified. The peak of the R wave of the beat 500 occurs at the time T.sub.R ( 509 ). The PQ segment 501 and ST segment 505 are sub-segments of the normal beat 500 and are located in time with respect to the time T.sub.R ( 509 ) as follows:
[0137] a. The PQ segment 501 has a time duration D.sub.PQ ( 506 ) and starts T.sub.PQ ( 502 ) milliseconds before the time T.sub.R ( 509 ).
[0138] b. The ST segment 505 has a time duration D.sub.ST ( 508 ) and starts T.sub.ST ( 502 ) milliseconds after the time T.sub.R ( 509 ).
[0139] The ST segment 505 and the PQ segment 501 are examples of sub-segments of the electrogram signal from a patient's heart. The R wave and T wave are also sub-segments. The dashed lines V.sub.PQ ( 512 ) and V.sub.ST ( 514 ) illustrate the average voltage amplitudes of the PQ and ST segments 501 and 505 respectively for the normal beat 500 . The “ST deviation” .DELTA.V ( 510 ) of the normal beat 500 is defined as:
[0000] .DELTA. V (510)= V .sub. ST (514)− V .sub. PQ (512)
[0140] The parameters T.sub.PQ, T.sub.ST, D.sub.PQ and D.sub.ST would typically be set with the programmer 68 of FIG. 1 by the patient's doctor at the time the cardiotracker 5 is implanted so as to best match the morphology of the patient's electrogram signal at a normal (e.g., resting) heart rate.
[0141] The R height V.sub.PQR ( 519 ) for the beat 500 is defined as
[0000] V .sub. PQR (519)= V .sub. R (503)− V .sub. PQ (512)
[0142] V.sub.PQ ( 512 ), V.sub.ST ( 514 ), V.sub.R ( 503 ), V.sub.PQR ( 519 ) and .DELTA.V ( 510 ) are examples of per-beat heart signal parameters for the beat 500 .
[0143] Although it may be effective to fix the values of start times T.sub.PQ ( 502 ) and T.sub.ST ( 504 ) and the time durations D.sub.PQ ( 506 ) and D.sub.ST ( 508 ), it is envisioned that the start times T.sub.PQ and T.sub.ST and the durations D.sub.PQ and D.sub.ST could be automatically adjusted by the cardiotracker 5 to account for changes in the R-R interval 507 (i.e., changes in the patient's heart rate). If the R-R interval 507 increases or decreases, as compared with the R-R interval for patient's normal heart rate, it is envisioned that the start times T.sub.PQ ( 502 ) and T.sub.ST ( 504 ) and/or the durations D.sub.PQ ( 506 ) and D.sub.ST ( 508 ) could be adjusted depending upon the R-R interval 507 for a specific beat or the average R-R interval for an entire electrogram segment. A simple technique for doing this would vary the start times T.sub.PQ and T.sub.ST and the durations D.sub.PQ and D.sub.ST in proportion to the change in R-R interval. For example, if the patient's normal heart rate is 60 beats per minute, the R-R interval is 1 second. At 80 beats per minute the R-R interval is 0.75 seconds, a 25% decrease. This could automatically produce a 25% decrease in the values of T.sub.PQ, T.sub.ST, D.sub.PQ and D.sub.ST. Alternately, the values for T.sub.PQ, T.sub.ST, D.sub.PQ and D.sub.ST could be fixed for each of up to 20 preset heart rate ranges. In either case, it is envisioned that after the device has been implanted, the patient's physician would, through the programmer 68 of FIG. 1 , download from the cardiotracker 5 to the programmer 68 , a recent electrogram segment from the recent electrogram memory 472 (of FIG. 3 ). The physician would then use the programmer 68 to select the values of T.sub.PQ, T.sub.ST, D.sub.PQ and D.sub.ST for the heart rate in the downloaded recent electrogram segment. The programmer 68 would then allow the physician to choose to either manually specify the values of T.sub.PQ, T.sub.ST, D.sub.PQ and D.sub.ST for each heart rate range or have the cardiotracker 5 automatically adjust the values of T.sub.PQ, T.sub.ST, D.sub.PQ and D.sub.ST based on the R-R interval 507 for each beat of any electrogram segment collected in the future by the cardiotracker 5 . It is also envisioned that only the start times, T.sub.PQ and T.sub.ST, might be automatically adjusted and the time durations D.sub.PQ and D.sub.ST would be fixed so that the average values of the ST and PQ segments V.sub.PQ ( 512 ), V.sub.ST ( 514 ), V′.sub.PQ ( 512 ′) and V′.sub.ST ( 514 ′) would always use the same number of data samples for averaging.
[0144] While the simplest method of adjusting the start times T.sub.PQ and T.sub.ST is to adjust them in proportion to the R-R interval 507 from the preceding R wave to the R wave of the current beat, a preferred embodiment of the present invention is to adjust the start times T.sub.PQ and T.sub.ST in proportion to the square root of the R-R interval 507 from the preceding R wave to the R wave of the current beat. It is also envisioned that a combination of linear and square root techniques could be used where T.sub.ST and D.sub.ST could be set to be proportional to the square root of the R-R interval while T.sub.PQ and D.sub.PQ could be linearly proportional to the R-R interval.
[0145] When pacemaker circuitry 170 is used with the cardiotracker 5 , it envisioned that the start time T.sub.ST and duration D.sub.ST of the ST segment may have different values depending on whether or not the heart is being paced. When the pacemaker is pacing the heart, the ST segment shifts so as to occur later relative to the start of the R wave as compared to the position of the ST segment when the pacer is not pacing the heart. It is also envisioned, that the offset for the start of the ST segment may be better measured from the S wave instead of the R when the pacemaker is not pacing. The technique of using different timing parameters for start and duration when pacing can be applied to analysis of any sub-segment of the electrogram including the sub-segment that includes the T wave peak. When the pacemaker circuitry 170 is used with the cardiotracker 5 , the algorithm for measurement of the ST segment can be adjusted to respond to either the pacing or no-pacing condition of the pacemaker circuitry 170 .
[0146] An example of a sequence of steps used to calculate the ST deviation 510 for the normal beat 500 is as follows:
[0147] 1. Identify the time T.sub.R ( 509 ) for the peak of the R wave for the beat 500 ,
[0148] 2. Calculate the R-R interval 507 and use that value to look up in a table or calculate the values of the start times T.sub.PQ, T.sub.ST and the time durations D.sub.PQ and D.sub.ST,
[0149] 3. Average the amplitude of the PQ segment 501 between the times (T.sub.R−T.sub.PQ) and (T.sub.R−T.sub.PQ+D.sub.PQ) to create the PQ segment average amplitude V.sub.PQ ( 512 ),
[0150] 4. Average the amplitude of the ST segment 505 between the times (T.sub.R+T.sub.ST) and (T.sub.R+T.sub.ST+D.sub.ST) to create the ST segment average amplitude V.sub.ST ( 514 ), and
[0151] 5. Subtract V.sub.PQ ( 512 ) from V.sub.ST ( 514 ) to produce the ST deviation, .DELTA.V ( 510 ) for the beat 500 .
[0152] At preset time intervals during the day the cardiotracker 5 will calculate the “average baseline ST deviation” .DELTA.V.sub.BASE defined as the average of the ST deviations .DELTA.V ( 510 ) for at least two beats of a baseline electrogram segment. Typically the ST deviation of 4 to 8 beats of the baseline electrogram segment will be averaged to produce the average baseline ST deviation .DELTA.V.sub.BASE which can be used for later comparison with the ST deviation of recent beats to identify changes indicative of a cardiac event such as an acute myocardial infarction. Fischell et al in U.S. Pat. No. 6,609,023 describe in detail the methods for detecting AMI and exercise induced ischemia.
[0153] As (for example) the ST deviation, .DELTA.V ( 510 ) or the QRS voltage, V.sub.QRS ( 511 ) for each beat is calculated, one or more histograms stored in the histogram data memory 43 of FIGS. 3 and 5 will be incremented with that specific value of that heart signal parameter.
[0154] FIG. 5 is an example of a structure for the histogram data memory 43 of the cardiotracker 5 of FIG. 3 . The histogram data memory 43 contains two types of histogram data, raw histogram data stored in the memory sections 430 through 43 N and extracted histogram data stored in the extracted histogram data memory 439 . One of the raw histogram data sections 430 through 43 N will always be the section currently being incremented as individual beats are processed by the processor 44 of FIG. 3 to compute the value of one or more heart signal parameters for each processed beat. The other histogram sections will usually be the histograms collected during prior data collection time periods.
[0155] In this example, each section 430 through 43 N has 5 histograms (e.g., section 430 has histograms 4301 , 4302 , 4303 , 4304 and 4305 ). Each of the 5 histograms in each section has a multiplicity of bins (e.g., histogram 4301 has bins 4301 a, 4301 b through 4301 y ). Each bin is a counter that is typically stored in one to 3 bytes of the histogram data memory 43 .
[0156] As the cardiotracker 5 processes a beat of the patient's electrogram, one or more heart signal parameters will be measured or computed for the beat. For each processed beat, the counter value of one bin in one of the histograms of the current histogram section will be incremented by one.
[0157] The choice of which bin in which histogram is incremented will be based on two heart signal parameters. The selection of one of the 5 histograms will be based on the value of a first heart signal parameter and the choice of which bin is to be incremented will depend upon the value of a second heart signal parameter. Specifically, a specific histogram will be selected if the value of the first heart signal parameter is within the range of the first heart signal parameter associated with that specific histogram. Similarly, a bin within the selected histogram will be incremented if the value of the second heart signal parameter is within the range of the second heart signal parameter associated with that bin.
[0158] For example, if the data collection time period used for tracking a heart signal parameter, like ST deviation, is one day and collected data retention time period is one week, then N=7 (i.e., section 43 N is section 437 ) and there will be 8 sections 430 through 437 in the histogram memory 43 with seven sections storing the data for each one of seven prior days and the eighth section storing the data for the current day. In this example, each of the five histograms per section correspond to a different range of R-R interval (or heart rate) [the first heart signal parameter] and each bin within a histogram corresponds to a different range of ST deviation [the second heart signal parameter]. As a further example, section 4301 corresponds to heart rates that are between 50 and 80 bpm and each of the bins 4301 a through 4301 y would correspond to a 5% wide (.+−02.5%) range of ST deviation as a percentage of baseline R height. Furthermore bin 4103 a would correspond to a range of ST deviation of −60%.+−02.5% of baseline R height and bin 4301 y would correspond to a range of ST deviation of +60%.+−02.5% of baseline R height. Therefore the bin 4301 n (not shown) would correspond to a range of ST deviation between +2.5% and +7.5% (i.e., 5%.+−02.5) of the average baseline level of ST deviation. This bin 4301 n would have the data shown as the highest bar of graph 601 in FIG. 6A . In FIG. 6A it is shown that there are a total of 25 bins in each of the histograms 601 - 605 inclusive. These bins run from −60% plus or minus 2.5% to +60% plus or minus 2.5%. The 14.sup.th bin is 4301 n which is +5% plus or minus 2.5% and the 25.sup.th bin in section 4301 is 4301 y which is +60% plus or minus 2.5%. The five different heart rate ranges shown for the histograms 601 to 605 inclusive of FIG. 6A would (for example) correspond to the sections 4301 to 4305 inclusive of FIG. 5 .
[0159] It is envisioned that the levels of ST deviation can be representative of actual voltages (e.g., millivolts) or they may be a normalized value with respect to the signal amplitude of the beat or electrogram segment. Examples of such a signal amplitude is the QRS voltage V.sub.QRS ( 511 ) or the R wave height above the PQ segment which is V.sub.PQR ( 519 ) of FIG. 4 .
[0160] In FIG. 5 , if section 432 is the present day's current histogram, then section 431 is from the day before, section 430 from 2 days before, and because the data rolls over, 437 (not shown) is the histogram for 3 days before, 436 (not shown) from 4 days before, 435 (not shown) from 5 days before, 434 (not shown) from 6 days before and section 433 (not shown) from 7 days before. For each beat analyzed by the cardiotracker for the current day's histogram, the R-R interval (heart rate) for that beat is used to select one of the histograms 4321 through 4325 and the value of ST deviation computed for that beat will be used to select the bin in the selected histogram that will be incremented by 1. Further using the labeling of FIG. 4 , assume the R-R interval for the beat just analyzed is within the heart rate range of the first histogram 4321 of the current section 432 and the ST deviation 510 of the beat analyzed is −0.1 millivolts which is −1% of the R height 519 . In this case the bin corresponding to a range of ST deviations that includes −1% of R height will be incremented by 1. In this way each beat is counted in one bin of one histogram of the current section, in this case, section 432 . Over a 24 hour period as the patient's heart rate (R-R interval) goes up and down, the histograms will track the ST deviation of each beat processed in each of the ranges of heart rate.
[0161] At the end of the data collection time period (24 hours in this example) during which section 432 is the current section, the cardiotracker will clear section 433 (the section with the oldest data) of all previously stored data and make section 433 (now empty) the current section for data collection. The previous current section 432 now becomes the section from one day before and is saved until the cycle repeats. On the day following the day where section 437 is the current day, section 430 will become the current section.
[0162] It is envisioned that before clearing section 433 , the cardiotracker might extract or analyze the data in 433 and save the extracted data in the extracted histogram data memory 439 . For example, the median value of ST deviation could be calculated for section 432 and that data could be time stamped as to the day of the year and placed into the extracted histogram data memory 439 . Alternately, the extracted data placed in the extracted histogram data memory 439 may be calculated for the current histogram section 432 at the end of the data collection time period where the section 432 was designated as the current section.
[0163] Examples of extracted data for any data collection time period can include any one, some or all of the following:
[0164] 1. number of beats in a histogram exceeding an ST deviation or ST shift threshold,
[0165] 2. average ST deviation or average ST shift,
[0166] 3. standard deviation of ST deviation or ST shift distribution (may include both positive and negative standard deviation values),
[0167] 4. total number of beats in the histogram (if there are very few beats in a particular histogram, using the average and/or standard deviation could be misleading),
[0168] 5. ST deviation or ST shift bin with greatest number of beats,
[0169] 6. the moving average over 2 or more data collection time periods of any of items 1 through 5 immediately above,
[0170] 7. the average of the QRS or RS width, and
[0171] 8. the average QRS voltage.
[0172] When the patient's physician downloads the data from the histogram data memory 43 (of FIG. 3 ), the histograms for the current data collection time period up to the time of download, and the complete histograms for the previous collected data retention time period can all be viewed using the physician's programmer 68 of FIG. 1 .
[0173] Although the examples above used one day per section as the data collection time period, shorter or longer periods are envisioned. Although 8 sections, (representing 7 days plus a current day's histogram section) are described above, with sufficient memory, a month (32 sections), a year (367 sections) or more of data can be saved in this format.
[0174] Although 5 histograms per section are described in the example above, it is envisioned that as few as one and as many as 100 could be used to collect relevant data. There are a number of heart signal parameters including QRS width or RS width of the electrogram wave form and R-R interval variability indicative of changes in the balance of the patient's sympathetic and parasympathetic nervous systems that are most likely to be tracked in a single histogram per data collection time period. Other heart signal parameters such as ST deviation, ST segment voltage, ST shift (ST deviation relative to average baseline ST deviation), T wave height, QRS voltage and/or R wave height may be preferably tracked with respect to heart rate (determined from R-R interval) using multiple histograms per section.
[0175] It is envisioned, that the data collection time period could be as short as a minute and as long as many months. A preferred embodiment uses a data collection time period of one day as collection on a daily basis would eliminate any affects from daily cycles (i.e., from circadian rhythm). A data collection time period of less than an hour would be useful to collect ST deviation vs. heart rate data during a stress test in the doctor's office. The data collected during such a stress test could be compared to earlier tests using analysis tools built into the physician's programmer 68 of the tracker system 10 . Histogram data does not require large amounts of data storage. For example, each of the five histograms 4321 through 4325 of FIG. 5 might have 25 bins 4321 a, 4321 b through 4321 y, with each bin requiring 2 bytes of data storage. Thus only 50 bytes are needed per histogram and 250 bytes for the entire section 432 . The eight sections would therefore require only 2 kilobytes, approximately 7.5 kilobytes would suffice for a month's (30 days) data and approximately 90 kilobytes for a year of data. Being able to store a one week to twelve month history of cardiovascular condition within the cardiotracker would be of tremendous value to cardiologists in diagnosing the progression of cardiovascular disease. Two byte bins are typically sufficient for a day's data as the cardiotracker is designed to only monitor some fraction of the beats (e.g., 10 seconds out of every 30 seconds) and a two byte counter could handle every third beat for 54 hours. If a longer data collection time period than 4 days is required, three bytes could handle more than year's worth of data where a third of all beats are captured. Four bytes per bin would be sufficient to count every heart beat for one hundred years.
[0176] It is also envisioned that the physician's programmer 68 of FIG. 1 could include the capability to manually clear the data in the current histogram. This would allow a “clean slate” for data collection from a stress test where, as each beat is analyzed, the ST deviation data build up is a representation of the patient's cardiovascular condition. It is also envisioned that a special cardiotracker data collection mode where every beat is analyzed could be enabled to collect more data during such a stress test. If every beat is too high a burden on the cardiotracker processor, then the cardiotracker might process a higher percentage of beats than during standard cardiotracker operation.
[0177] The actual turnover time for automated clearing of the oldest histograms at the end of each data collection time period would be programmable (e.g., midnight of the patient's time zone for a one day data collection time period). If the manual clearing function is used, it is envisioned that the current section of histogram memory would still be used until the next turnover time.
[0178] FIG. 6A is an example of a histogram set 600 consisting of five histograms 601 through 605 inclusive representing an example of a programmer display screen of a single section of histogram data memory 43 of FIG. 3 for a single data collection time period (viz., one day). In FIG. 6A , the horizontal scale is the ST deviation (i.e., ST segment voltage minus PQ segment voltage) as a percent of the R height, V.sub.PQR ( 519 ) of FIG. 4 . Also in FIG. 6A , the vertical scale of each histogram 601 through 605 is the number of beats in the data collection time period (viz., one day) where the ST deviation was in one of the ranges listed on the horizontal scale of the histogram. Each of the five histograms 601 through 605 represents all the beats processed (during the data collection time period of one day) that had R-R intervals corresponding to the heart rate range for that histogram. It is envisioned that the heart rate (or R-R interval) ranges for each histogram 601 through 605 may be either permanently set or programmable using the physician's programmer 68 of FIG. 1 . In the histograms 601 through 605 each bin represents a range of ST deviation expressed as a percentage of the R height, V.sub.PQR ( 519 ) as shown in FIG. 4 . Each bin represents the shown value of −60, −55, −50, . . . +60, in percent of R height plus or minus 2.5%. Therefore, each bin covers a range (i.e., a class interval) of 5% of the R height 519 . The bin showing the value 5 (i.e., +5%) in histogram 601 would be incremented by one every time a beat with an R-R interval corresponding to a heart rate of 50 to 80 bpm had an ST deviation between 2.5% and <7.5% of the R height of that beat. The next higher bin would be 7.5% to <12.5% of the R height, and so on. It is also envisioned that instead of using the R height 519 of each beat as the reference, the average R height of a multiplicity of beats of a baseline electrogram segment would be used as a reference.
[0179] Although the heart rate range for histogram 602 in FIG. 6A is shown as 81 to 100 bpm, the cardiotracker will classify any beat whose R-R interval corresponds to a heart rate greater than 80 bpm and less than or equal to 100 bpm as belonging in this heart rate range. Similarly the heart rate range labels of 101 to 120 bpm (histogram 603 ), 121 to 140 bpm (histogram 604 ) and 141 to 160 bpm (histogram 605 ) will include beats with R-R intervals corresponding to heart rates of >100 to <120 bpm, >120 to <140 bpm and >140 to <160 bpm. This correspondence is also applied to the charts in FIGS. 6B , 7 A, 7 B, 8 A and 8 B wherever heart rate ranges are specified.
[0180] The technique of expressing ST deviation as a percentage of R height 519 compensates for signal level variations from causes such as long term changes in electrode impedance or changes in the gain of an amplifier. As an alternative, it is also envisioned that the actual voltage or signal level or the percentage of a preset maximum signal level for the ST deviation (e.g., millivolts) could be used as the range for each bin in the histograms 601 through 605 . For example, the bins in 601 might represent between −60% to +60% of a maximum signal level of 10 millivolts. Thus the bin labeled 5 would be incremented if the ST deviation was between 2.5% and 7.5% of 10 millivolts (i.e., 0.25 to 0.75 millivolts). The technique described here will work with preset bin ranges. Preferably, this invention envisions bin ranges that can be set by the physician using the physician's programmer 68 of FIG. 1 .
[0181] Also shown in FIG. 6A are the median (or average) values 611 through 615 inclusive of the histograms 601 through 605 respectively. The median value and number of beats counted in a histogram are useful extracted data that would typically be saved in the extracted histogram data memory 439 of FIG. 5 . The medians and numbers of beats can also be used to compute moving averages by either the cardiotracker 5 or programmer 68 of FIG. 1 . It is envisioned that comparison of the medians and/or the moving averages to pre-set thresholds can be used to alert the patient to a significant change in their cardiovascular condition.
[0182] FIG. 6B shows a set of histograms 650 consisting of the histograms 651 , 652 and 653 at three different ranges of heart rate (50 to 80, 81 to 100 and 101 to 120 bpm) for the heart signal parameter QRS voltage calculated as a percent deviation from the baseline QRS voltage. In FIG. 6B , the horizontal scale represents 41 histogram bins (from −20% to +20%) with each bin corresponding to the labeled percent deviation of QRS voltage from the baseline QRS voltage plus or minus 1%. Also in FIG. 6B , the vertical scale represents the number of heart beats whose percentage deviation from the baseline QRS voltage fell within each of the 41 bins during the data collection time period (e.g., one day). For example, for the histogram 651 , in the bin labeled “− 2 ” there were 3,000 recorded beats that had a percentage difference between the measured QRS voltage and the baseline QRS voltage between −3% and −1%. For example, if the baseline QRS voltage was 10 millivolts, histogram 651 shows that there were 3,000 beats with measured QRS voltage between 9.7 and 9.9 millivolts. Similarly, the bin to the right of the −2% bin of histogram 651 indicates that approximately 600 beats during the data collection time period had a QRS voltage within .+−0.1% of the baseline QRS voltage.
[0183] The dashed lines 661 , 662 and 663 represent the average values −2%, −4% and −8% of the histograms 651 , 652 and 653 respectively. The average value dashed lines 661 , 662 and 663 represent respectively the median (or mean) values of the percent QRS voltage deviation for three different heart rate ranges, namely: 50-80 bpm, >80-100 bpm and >100 to 120 bpm for the histograms 651 , 652 and 653 . The heart rate ranges can be set and adjusted by the medical practitioner using the programmer 68 of FIG. 1 .
[0184] FIG. 7A is a histogram display 700 that shows five different heat rate ranges of histograms for three different days 701 , 703 and 707 . This representation would typically be shown as a screen on the physician's programmer 68 of FIG. 1 . The display 700 of FIG. 7A would allow the physician to examine trends in the ST deviation vs. heart rate over time. This example clearly shows in day 7 (chart 707 ) that there is a significant change in the distribution of ST deviation at higher heart rates as compared with days 1 and 3. This would be indicative of a narrowing or partial occlusion of one or more coronary arteries in the heart. Although this is a good way to look at changes between two different time periods, the display of FIG. 8A is a preferred means to clearly see such changes. It is also envisioned that instead of the distributions of ST deviation as shown in FIG. 7A , the average or median ST deviations for each heart rate range could be displayed as a single vertical bar or line.
[0185] FIG. 7B is a histogram display 750 that shows three different heart rate ranges for three different days 751 , 753 and 757 . Comparable to FIG. 7A , FIG. 7B shows the histograms for QRS voltage for a multiplicity of beats plotted as a percent deviation from the baseline QRS voltage.
[0186] FIG. 8A is a graphical representation 800 of the five day moving average of the average daily ST deviation for each of five heart rate ranges 801 through 805 inclusive for a period of 26 weeks (6 months). The display 800 as shown in FIG. 8A , would be of tremendous value to a cardiologist in recognizing a gradual but potentially life threatening change in a patient's cardiovascular condition. As a patient with the cardiotracker 5 of FIG. 1 goes about daily activities their heart rate will go up and down. Each beat analyzed by the cardiotracker (typically between 6 and 80 beats in any particular minute) will increment the appropriate heart rate range related histogram allowing the cardiotracker 5 to store the daily distributions of ST deviation in the five different heart rates. While the cardiotracker 5 may only store the histogram data for a week or two, the extracted histogram data memory 439 of FIG. 5 could be used to store extracted histogram data for a much longer period of time. In fact, the use of extracted histogram data is an extremely efficient way to track the changes in heart signal parameters over an extended period of time. For example storing the average ST deviation and number of beats in each of five daily histograms (5 heart rate ranges) requires only 15 bytes per day within the extracted histogram data memory 439 . This translates to approximately 450 bytes per month and 5,500 bytes per year. This efficient data storage can be compared with electrogram data storage where at 200 samples per second, 30 seconds of electrogram storage requires 6,000 bytes of data storage.
[0187] The display 800 could result from calculations made by the programmer 68 of FIG. 1 after downloading six months worth of daily histograms or extracted histogram data from the cardiotracker 5 . Alternatively, the programmer 68 could combine data downloaded from the cardiotracker 5 on multiple occasions. Moving averages could also be calculated within the cardiotracker 5 or within the programmer 68 from the daily average or median value for ST deviation using the beat count extracted from the histogram data. Such calculations would not overly tax the power consumption on the cardiotracker 5 as the calculations would require at most a few seconds of processor time per day.
[0188] It is also envisioned that the cardiologist might set an alarm threshold 820 for any or all heart rate range curves so that when one or more of the five day moving averages of ST deviation crosses the limit, the patient would be alerted. Different thresholds for each heart rate range could also be implemented. In the example of FIG. 8A , the alarm threshold 820 for the 121-140 bpm heart rate range 804 was set to −12% of the R height, and a SEE DOCTOR ALERT would have been initiated by the cardiotracker 5 two weeks before the current date. It is envisioned that the programmer 68 would allow the physician to set these detection thresholds. The programmer 68 would also allow the physician to specify what type of alarm will be generated by the cardiotracker 5 if the detection threshold is passed, e.g., either a SEE DOCTOR ALERT or an EMERGENCY ALARM. It is also envisioned that detection thresholds could be set for the slope of the curves of FIG. 8A so that significant downward slope of ST deviation would initiate a patient alert. Also, it is envisioned that a combination of a specific value above the threshold 820 when combined with a specific downward slope could also be used to trigger a SEE DOCTOR ALERT.
[0189] Instead of using the fixed threshold 820 for triggering a SEE DOCTOR ALERT from the 5 day moving average of the average ST deviation for each heart rate range, an adaptive threshold that is based on the difference between the maximum and minimum of the 5 day moving average curves exceeding a preset threshold is a preferred embodiment for the present invention.
[0190] The processing of extracted histogram data would typically be performed once per day although longer and shorter data collection time periods are also envisioned. An example of the extraction process for average ST deviation would be as follows:
[0191] 1. Once per data collection time period (e.g., once per day), the ST deviation histogram data collected during the previous data collection time period is summarized, stored and analyzed. For each heart rate range, estimates are made of the average (e.g., mean and/or median) ST deviation, the average −1 sigma and the average +1 sigma of the ST deviation.
[0192] 2. Other data, e.g., number of analyzed beats in each heart rate range and the average 24 hour baseline signal amplitude (e.g., R height or QRS voltage) may also be stored as part of the summary data.
[0193] 3. An N day moving average (N is typically between 1 and 30) of the daily average (e.g., mean or median) ST deviation for each heart rate range is then determined, along with the maximum and minimum values of the N day moving averages for each heart rate range.
[0194] If the difference between the maximum moving average and the minimum moving average of the ST deviation for any of the ST deviation moving average curves 801 through 805 exceeds a preset threshold, an ST deviation histogram trending event for that heart rate range can be detected. If enabled, a SEE DOCTOR ALERT would then be triggered.
[0195] The hour at which the daily extraction would occur is programmable by the doctor so that detection of such a trending event would trigger the SEE DOCTOR ALERT at time that is convenient to the patient (e.g., not while he would be sleeping). Once a SEE DOCTOR ALERT has been triggered and the patient has had therapy (e.g., a stent or angioplasty procedure) that relieves the ST depression (or elevation) the programmer 68 of FIG. 1 can be used to reset the start date for future histogram trending analysis so that the ST shift data that caused the alert in the past is not used in future analysis. An alternative technique to accomplish this is to clear all previously stored histogram data from the cardiotracker memory once the ST shift has been treated. Therefore any new analysis would not include the data that caused the histogram trending event. The prior data would however, remain in the programmer 68 for later review and tracking of the patient's history.
[0196] For example, once per day at noon, to avoid alerting the patient when he might be asleep, the cardiotracker could calculate the daily average (mean or median) ST deviation from the histogram for each heart rate range (e.g., 601 through 605 ) of FIG. 6A . The cardiotracker would then calculate the 5 day moving average that includes the just calculated daily average ST deviation and the averages from the four previous days. The cardiotracker could then identify the maximum and minimum values of the moving average data for each heart rate range after a start date set by the programmer 68 . If the difference between the maximum and minimum values exceeds a preset threshold for any heart rate range, then a histogram trending event is detected and, if enabled, a SEE DOCTOR ALERT would be triggered in the implanted cardiotracker 5 .
[0197] FIG. 8B illustrates a display 850 on the physician's programmer 68 for the median (or mean) value of the percent deviation of QRS voltage over a six month period compared to a baseline QRS voltage. The display 850 shows the percent deviation for QRS voltage for three different heart rate ranges corresponding to the heart rate ranges shown for FIGS. 6B and 7B . The three curves, 851 , 852 and 853 correspond respectively to the heart rate ranges of 50-80 bpm, 81-100 bpm and 101 to 120 bpm.
[0198] It is expected that the display 850 of FIG. 8B would be of great value to doctors who treat heart transplant patients. Specifically, it has been shown by Warnecke, et al that a decrease of 8% in the QRS voltage from a baseline QRS voltage value from a time when the heart is not being rejected can indicate rejection of a transplanted heart at an early enough time to change the patient's medication to save that heart. The present “gold standard” for detecting rejection is a biopsy that (starting two years after implant) is typically carried out only once each six month time period. This biopsy is done in a catheterization laboratory and it is typically difficult for the patient and quite expensive. Also, if rejection occurs starting at some time between the six month biopsy procedures, then that early detection of rejection will not be possible. If however, a patient has an implanted cardiotracker 5 that has an alarm that is triggered by the −8% decrease in QRS voltage, then that SEE DOCTOR ALERT setting 860 as shown in FIG. 8B will occur and the heart in that transplant patient can be saved by appropriate medication therapies. It is envisioned that the setting of the level 860 for triggering a SEE DOCTOR ALERT could be between −1% and −20% below the baseline value of the QRS voltage. Furthermore, one could combine a negative slope of any of the curves of FIG. 8B with a higher value for triggering the SEE DOCTOR ALERT. For example, if a slow descent of the percent deviation of QRS voltage utilized a −8% drop as the level to set off the SEE DOCTOR ALERT, it is envisioned that a level of (let us say) −6% could be used to set off the SEE DOCTOR ALERT if the downward slope corresponded to (let us say) a −1% per week decrease in QRS voltage. Thus the patient would be warned two weeks earlier that he is going to reach the level of −8% when his doctor would prescribe a change in the patient's medication regime.
[0199] While it may be sufficient to detect transplant rejection when the deviation of average daily QRS voltage as compared to the baseline QRS voltage exceeds a preset threshold for a single day, it may be more reliable to require that the threshold be exceeded for two or more consecutive days. An example of the extraction process for average (mean or median) QRS voltage would be as follows:
[0200] 1. Once per data collection time period (e.g., once per day), the QRS voltage data collected during the previous data collection time period is summarized, stored and analyzed. For each heart rate range, calculations are made of the average (e.g., mean and/or median) QRS voltage and the average −1 sigma and average +1 sigma deviations of the QRS voltage.
[0201] 2. Other data, e.g., number of analyzed beats in each heart rate range baseline R height for the past 24 hours could also be stored as part of the summary data.
[0202] If the average QRS voltage has declined more than a preset percentage of the baseline QRS voltage, a transplant rejection event for that heart rate range will be detected. If enabled, a SEE DOCTOR ALERT would then be triggered. The baseline QRS voltage is an average QRS voltage captured at an earlier time when the transplanted heart was not experiencing rejection. It is also envisioned that to reduce the possibility of a false positive detection, a SEE DOCTOR ALERT would only be triggered after a specified number of successive transplant rejection events. For example, it might require two or three successive transplant rejection events to trigger the alert.
[0203] The hour at which the daily extraction of collected data would occur is programmable by the doctor so that detection of such an event would trigger the SEE DOCTOR ALERT at a time that is convenient to the patient (e.g., not while the patient would be sleeping). Once a SEE DOCTOR ALERT has been triggered and the patient has had therapy (e.g., an increase in cyclosporine) that reverses the rejection episode, the programmer 68 of FIG. 1 can be used to reset the baseline QRS voltage so that the data that caused the alert is in the past and is not used in future analysis.
[0204] For example, once per day at noon, the cardiotracker will calculate the daily average (mean or median) QRS voltage from the histogram for each heart rate range (e.g., the heart rate ranges 651 through 653 of FIG. 6B ). If the difference between the recently calculated average QRS voltage and the baseline QRS voltage exceeds a preset threshold 860 for any heart rate range, then a transplant rejection event is detected and if enabled, a SEE DOCTOR ALERT (or possibly an EMERGENCY ALARM) is triggered.
[0205] Although a decline in the average QRS voltage is cited here as a known means for early detection of rejection for a transplanted heart, it is also envisioned that some other heart signal parameter may be equally or better suited for that purpose. Specifically, ST deviation or ST shift, R wave slope, QRS complex width or another heart signal parameter could be used for the early detection of rejection of a transplanted heart. Furthermore, it is envisioned to place an accelerometer onto the end of an epicardial or endocardial lead, which end is firmly attached to the heart muscle, to detect a change in heart wall motion that could be indicative of early rejection. The combination of a means to measure heart wall motion with a second means to detect a change in a heart signal parameter is also envisioned as a means for early detection of the rejection of a transplanted heart.
[0206] Although ST deviation and QRS voltage have been the primary examples used here for histogram data collected based on a patient's heart rate, it is envisioned that any other heart signal parameter measured or calculated can be usefully used with this histogram methodology. Examples of such parameters include QRS or RS complex width, ST shift (ST deviation compared to a baseline ST deviation), R wave width, T wave shape, T wave alternans, changes in R-R interval variability and number of overly long R-R intervals. These parameters may be monitored independent of the patient's heart rate, or separate histograms could be used for each of multiple heart rate ranges.
[0207] Although the present invention has described the use of histogram memory for cardiovascular electrical signals, these techniques are also applicable for electrical signals collected using electrodes from other portions of the human body. Such electrical signals include signals from the human brain, gastrointestinal tract, the liver, the pancreas and musculature. Any of these organs may (for example) have a change in their electrical signal that might indicate an early stage of rejection. Furthermore, although only electrogram related histograms have been described herein, it should be understood that other measurements including measurements by heart motion sensors, temperatures at certain places in the body and devices to measure pressure and/or pO.sub.2 may be used to generate histograms of cardiovascular condition of the patient.
[0208] It is also envisioned that all of the processing techniques described herein for an implantable cardiotracker are applicable to a tracker system configuration using skin surface electrodes and a non-implanted cardiotracker. For systems that were totally external to the patient, the term “electrogram” would be replaced by the term “electrocardiogram”. Thus the cardiotracker device described in FIGS. 1 through 3 inclusive would also function as a monitoring device that is completely external to the patient.
[0209] It is important to note that many of the functions of the tracker system as described herein that are programmable by a medical practitioner could be preset in manufacture to typical settings that are useful for most patients. Thus the doctor could use this default mode instead of trying to set particular alarm parameters for a particular patient. Furthermore, the physician's programmer 68 could have a default mode to restore all the settings of either or both the cardiotracker 5 and external alarm system 60 to values that are recommended by the manufacturer. There may also be separate default settings for men and woman and others that would be related to a specific medical problem that the patient has.
[0210] Although the histogram technique is a preferred embodiment of the present invention as it greatly reduces the amount of memory needed to store the values of a heart signal parameter for each beat analyzed during a data collection time period, it is also envisioned that the each measured or calculated value of one or more heart signal parameters could be directly stored in memory. For example, the value of ST deviation would be measured for each beat during a one hour data collection time period (e.g., during a stress test). These values would all be stored in memory and at the end of the data collection time period, the average ST deviation for each heart rate range could be calculated from the stored values. This technique would be of greatest value where the data collection time period is shorter than a day.
[0211] Various other modifications, adaptations, and alternative designs are of course possible in light of the above teachings. Therefore, it should be understood at this time that, within the scope of the appended claims, the invention can be practiced otherwise than as specifically described herein. | Disclosed is a “tracker system” that includes implanted electrical leads which are part of an implanted cardiotracker plus external equipment that includes external alarm means and a physician's programmer. The tracker system is designed to monitor the degradation of a patient's cardiovascular condition from one or more causes. These causes include the rejection of a transplanted heart and/or the progression of a stenosis in a coronary artery. As one or more stenoses in a coronary artery become progressively more narrow thereby causing reduced blood flow to the heart muscle coronary circulation, the tracker system can alert the patient by either or both internal and/or external alarm means to take the appropriate medical action. The physician's programmer can be used to display histograms of key heart signal parameters that are indicative of the patient's cardiovascular condition. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a ventilator for a glass block window and associated products.
2. Background Information
Ventilators for glass block windows are known. For example, U.S. Pat. No. 5,675,948 discloses such a ventilator in which a sash tilts away from a frame that is mounted in a glass block window. The sash, however tilts such that rain, snow and the like can be captured by the sash and directed into an opening in the ventilator. This particular ventilator also includes a screen disposed interiorly of the sash, however, that screen appears to be fixedly mounted in the frame, thus making removal thereof difficult, if not impossible.
What is needed is an improved ventilator for a glass block window that overcomes the shortcomings of the prior art, and particularly, the ventilator shown in U.S. Pat. No. 5,675,948.
SUMMARY OF THE INVENTION
The invention has met or exceeded the above-captioned needs as well as others. A ventilator for a glass block window is provided that includes a window frame, a window sash pivotably mounted in the window frame and a screen also pivotably mounted in the window frame. Preferably, the window sash is pivotable between a closed position and an open position such that when the window sash is in the open position, rain and snow and the like are resisted from passing through the ventilator and into the building which has the glass block window.
The invention also encompasses providing a ventilator as described above without the screen. Finally, a screen for a window is also provided. The screen of the invention is pivotably mounted to the window frame of the window. This screen can be used not only for the ventilator but also for other types of windows.
BRIEF DESCRIPTION OF THE DRAWINGS
A full understanding of the invention can be gained from the following detailed description of the invention when read in conjunction with the accompanying drawings in which:
FIG. 1 is an elevational view of a glass block window looking from the inside of a building in which the glass block window is installed.
FIG. 2 is a perspective view, partially cutaway, showing the ventilator separated from the glass block window and also showing the window sash in an open position.
FIG. 2A is a detailed view of one of the hinge members.
FIG. 2B is a cross-sectional view taken along line 2 B— 2 B of FIG. 2 A.
FIG. 3 is an elevational view, partially cutaway, showing the ventilator separated from the glass block window and also showing the window sash in a closed position.
FIG. 4 is a back perspective view, partially cutaway, showing the pivotable screen of the invention in a closed position.
FIG. 5 is a view similar to FIG. 4 only showing the screen pivoted to the open position.
DETAILED DESCRIPTION
FIG. 1 shows a glass block window 10 . The glass block window 10 consists of a plurality of square glass blocks, such as glass block 12 , arranged in a rectangular shape to form a completed glass block panel 14 . The glass blocks are joined together with a bonding type material 16 such as, for example, mortar. The ventilator 20 of the invention is mounted, preferably, in the center of the glass block window. As is known, the ventilator 20 provides a method of providing ventilation to an area enclosed by the glass block window 10 .
Referring now more particularly to FIGS. 2 and 3, the ventilator 20 of the invention will be discussed in more detail. The ventilator 20 includes a frame 22 that is comprised of a left jamb 24 , right jamb 26 , superior head 28 and interior sill 30 . These portions are preferably made of an extruded vinyl, although other materials, such as aluminum, can be used. The vinyl extrusions are welded together to form the frame 22 . In accordance with the invention, a sash 40 is pivotably mounted in the frame 22 . The sash 40 shown is rectangular in shape and corresponds to the dimensions of the opening in the frame 22 . The sash 40 is fixed to the superior head 28 of the frame 22 and pivots about a pivot line P—P that is generally horizontally disposed. The sash 40 includes a sash frame 42 , which includes a vertical left portion 44 , a vertical right portion 45 , a horizontal top portion 46 and a horizontal bottom portion 47 . Portions 44 - 47 are separate miter cut extruded vinyl pieces which are welded together. Mounted in the sash frame 42 is a double panel window 48 . The window 48 is mounted by any known means. It can be appreciated that the exterior pane of glass can be translucent to obscure any view into the building through the glass. The interior pane of glass can be transparent.
FIG. 3 also show the sash latch 50 . This is a standard pivotable latch including an extended handle portion 52 and a lower tab portion 54 that is adapted to fit into an engaging portion 56 formed in frame 22 .
Referring to FIGS. 2, 2 A and 2 B, the sash 40 is pivotably mounted to the frame 22 by means of a pair of hinge members 60 , 62 . Each hinge member 60 , 62 is similar in construction. Each hinge member includes a bar, such as bar 64 defining a lower slot 66 of hinge member 62 . A fastener attaches a first end of the bar to vertical portions of the sash frame. FIG. 2 shows one such fastener 68 which is attached to sash frame member 44 . A second fastener, such as fastener 72 of hinge member 62 , is attached to the right jamb 26 . The fastener 72 includes a head portion 73 and an underlying washer 74 . The head portion 73 and washer 74 preferably have a diameter greater than the width of the slot 66 . The second fastener 72 is disposed in the lower slot 66 (FIG. 2 A). It will also be seen that the lower slot 66 also defines a notched area 76 defined by inwardly facing notches 77 and 78 . The fastener 72 includes a bushing 79 on which the bar 64 slides against.
In operation, when it is desired to move the sash 40 from the closed position (FIG. 2) to the open position (FIG. 3 ), the sash 40 , if necessary, is unlocked from the frame 22 by using the sash latch 50 . The user then pushes the sash frame 42 near its bottom to cause the bottom to pivot away from the frame along the pivot line P. The pivot line P is generally horizontal in orientation and is disposed generally along the upper portion of the frame 22 , as is shown in FIG. 2 . This at first causes the bar 64 to rotate, and then to move upwardly along an angular path due to the second fastener 72 . At some point, the second fastener 72 engages the notches 77 and 78 . At that point the user applies a greater outward pressure on the sash 40 to allow the bar 64 to keep moving upward and beyond the notched area 76 . Once the second fastener 72 is past the notched area 76 , the sash 40 is in its full open position (FIG. 3) and will stay there due to the presence of the notches 77 and 78 .
There are several advantages to this structure and operation over the prior art. The greatest advantage is that the sash forms an awning that resists the entry of snow and rain into the opening of the ventilator. This can also include water runoff from the sides of the building in which the glass block window is mounted. This arrangement prevents moisture from lying on the interior sill 30 of the frame 22 , thus increasing the effectiveness and useful life of the ventilator.
In order to return the sash 40 to the closed position (FIG. 3 ), the process is reversed, with an extra inward force from the user being used to clear the second fastener 72 past the notched area 76 . The sash 40 is then pivoted back to the closed position (FIG. 2) and sash latch 50 is locked.
FIGS. 2 and 3 also show the large bubble type insulation bead 78 that is disposed around the edge of the sash frame 42 . This provides superior insulation properties for the ventilator to reduce heating and cooling costs.
Referring now to FIGS. 4 and 5, the pivotable screen 80 of the invention will be discussed. The pivotable screen 80 can be moved from a closed position (FIG. 4) to an open position (FIG. 5 ). The screen 80 includes a pair of vertically opposed frame members 82 , 83 and a pair of horizontally opposed members 84 , 85 which form a frame having an opening in which is disposed a standard mesh screen 88 .
The screen 80 is fixed in a closed position by means of a standard screen latch 90 that includes a handle portion and an extending tab portion. As is known, the tab portion 93 engages into an engaging slot formed in the jamb 24 .
In order to move the screen 80 , it is unlocked (if necessary) and then pivoted to the open position (FIG. 5) on pivot line P 1 . Preferably, the screen 80 is pivotably mounted in the frame 22 by means of hinge pins 95 and 96 disposed on the upper and lower left hand portions of the screen 80 which engage into complementary holes (not shown) in the frame 32 (FIG. 4 ). When it is desired to move the screen 80 to the closed position (FIG. 4) the process is merely reversed, and the screen latch 90 is locked.
It will be appreciated that the pivotable screen is not limited to application for glass block window ventilators, but can be used in association with any type of window whether double hung, casement or awning type windows. The advantages of the pivotable screen are numerous. In the case of a ventilator for a glass block window, the pivotable screen allows for easy access of entry for certain household items, such as garden hoses and electrical cords. With the prior art ventilators, this was not possible, as the screen was fixed in the frame. Furthermore, the pivotable screen allows for easier access to clean the interior of the sash and the interior portion of the window. If the screens are used on double hung windows and thus disposed exteriorly of the window surface, the screen can be merely pivoted out of the way instead of being totally removed, thus making cleaning of the exterior surface of that double hung window much easier.
It will be appreciated that a ventilator for a glass block window is provided that has numerous improvements over the prior art. A pivotable screen, which can be used not only for the ventilator but also for other types of windows, is also provided.
While specific embodiments of the invention have been disclosed, it will be appreciated by those skilled in the art that various modifications and alterations to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breath of the appended claims and any all equivalents thereof. | The invention comprises a ventilator for a glass block window that includes a window frame, a window sash pivotably mounted in the window frame and a screen also pivotably mounted in the window frame. The window sash is pivotable between a closed position and an open position such that when the window sash is in the open position, rain and snow and the like are resisted from passing through the ventilator and into the building which has the glass block window. The invention also encompasses providing a ventilator as described above without the screen. Finally, a screen for a window is also provided. The screen is pivotably mounted to the window frame of the window. This screen can be used not only for the ventilator but also for other types of windows. | 4 |
CONTINUITY
[0001] This is a continuation-in-part of my U.S. patent application Ser. No. 08/058,197, filed May 4, 1994, which is a continuation of my U.S. patent application Ser. No. 826,491, filed Jan. 27, 1992, now U.S. Pat. No. 5,233,773, which issued Aug. 10, 1993, which is a continuation-in-part of U.S. patent application Ser. No. 07/536,765, filed Jun. 11, 1990, now U.S. Pat. No. 5,111,606, which issued May 12, 1992.
FIELD OF INVENTION
[0002] The present invention relates to lighted merchandising display devices for advertising purposes in stores and, more particularly, provides a flexible display device having a battery supply mount. The device is engineered and employed principally for locations in mercantile establishments such as grocery stores, supermarkets, discount centers, and the like.
BACKGROUND AND BRIEF DESCRIPTION OF PRIOR ART
[0003] In the past there have been several different types of approaches taken in advertising merchandise carried on grocery store shelves, in refrigerator cabinets, and so forth. Advertising media are important, of course, to draw the attention of shoppers to various specials, new items, and featured items for a particular sale. Merchandisers have noted the advantages of having lighted signs or sign displays proximate merchandise such as canned goods to be placed on special. Many conventional signs have their electrical circuits connected to an AC source; this is impractical, however, because the provision of multiple AC outlets along a very long shelf display becomes prohibitively expensive. Certain display signs carry a battery pack proximate the display area; however, this does interfere with the viewing of the sign, especially bi-directional viewing to accommodate customers. A further problem in the prior art is presented in the case of rigid signs which might be inadvertently bumped and possibly damaged should a rigid connection be maintained between the outwardly projecting sign and its mount to a shelf, for example. A certain flexibility feature relative to the sign and its mount to the shelf has been adopted in the past as is evidenced by U.S. Pat. Nos. 4,881,707 and 4,805,331; also, certain approaches have been taken in supplying battery power to signs, but which exclude practical application relative to the sign for bi-directional viewing, see U.S. Pat. Nos. 4,317,303 and 4,924,363.
[0004] For several reasons, and not believed disclosed in the prior art, what is needed is a battery supply proximate, i.e., at the mount of the device at the shelf proper, or the refrigerator enclosure which is to incorporate the sign. In this way both forward and rear surfaces of the outwardly projecting signs are completely free and unobstructed for viewing in either direction; this magnifies the uses of the sign for traffic in both directions in stores utilizing the device. A further feature which is needed, and not believed shown in the prior art, is the concept of having electrical connection from the battery station fixed adjacent to the shelf, to and through the flexible or articulative structure to the electrical circuit board of the sign proper. There is no art currently known to the inventor which teaches the concept of supplying electrical leads, for example, or other electrical connections between a battery supply mount and a flexible lighted sign, through a tongue, or spring, or articulative joint, so as to preserve resilience to the structure, and yet not interfere with sign lighting or the displacements and automatic restoration of the sign relative to its mount. A number (24) of U.S. patents are known which bear upon signs in general, however, and will be of interest and, to some small degree, relevant. These are as follows:
1. Des 243,639 9. 3,070,911 17. 4,096,656 2. Des 245,945 10. 3,084,463 18. 4,317,303 3. 469,487 11. 3,226,866 19. 4,682,430 4. 900,590 12. 3,517,937 20. 4,805,331 5. 2,654,172 13. 3,696,541 21. 4,819,353 6. 2,817,131 14. 3,931,689 22. 4,881,707 7. 2,924,902 15. 4,028,828 23. 4,924,363 8. 3,041,760 16. 4,055,014 24. 4,984,693
[0005] A primary difficulty with respect to traditional sign displays, particularly bi-directionally viewable sign displays located within aisles of a store, has been a need for the sign display to be flexible and resilient. It is desirable for the sign display to be deflectable in a horizontal or side-to-side direction in addition to being deflectable in an up-and-down or vertical direction. As such, the sign can be deflected regardless of the angle of impact (either from a shopping cart or a person) and resiliently returned to its original position.
[0006] Another traditional problem with respect to sign displays, again particularly bi-directionally viewable sign displays within an aisle of a shopping area, involves the impediment created by the sign display in stacking shelves and removing items from shelves. Such sign displays that are rectangular may extend above and below the particular shelf area to which it is attached. This can impede access to the shelf.
[0007] Still another problem with respect to sign displays relates to the presentation angle of the sign display so that it is pleasing from a marketing standpoint. Since particular sign displays may vary in terms of shape and size, it is desirable to have an ability to change the angle at which the sign display is positioned to provide a desirable presentation angle for marketing purposes.
[0008] With respect to illuminated sign displays in particular, the power supply, similar to the sign display, may impede access to shelf storage areas depending on the orientation of the power supply. There is therefore a need to incorporate a power supply into a sign display that minimizes impedance with access to shelf storage areas.
[0009] Another problem with respect to lighted sign displays is the light necessary for illuminating the sign display. Traditional sign displays have required several light sources. Therefore, each light source is susceptible to failure, which requires repair and/or replacement. The fewer light sources incorporated into the sign display, the fewer number of potential failures involved.
[0010] Another primary design concern with respect to sign displays is the attention it provides to the particular shelf to which it is attached. In a typical shopping aisle, there are so-called primary shelves and secondary shelves. The primary shelves are typically eye level and are the easiest, most convenient shelves for the shopper to view. The present invention is designed to overcome primary/secondary shelf distinction by rendering any shelf to which the sign display of the present invention is attached a primary shelf.
BRIEF DESCRIPTION AND OBJECTS OF THE INVENTION
[0011] In the present invention a lighted merchandising display includes its own individual electrical circuit such as a circuit board for powering lights disposed at the margins or about the periphery of the display, this preferably at opposite sides of the frame of the display. The display is of a slim-line design and has viewing windows on opposite sides of the frame so that advertising matter may be viewed from both sides of the display as customers are approaching the display. A battery pack, case or holder is provided and is directly mounted to the shelf molding of the display shelf, or also to the transparent door of a refrigerator or freezer, by way of example. The display frame relative to the battery pack is flexibly connected so as to allow for temporary deflections of the sign should passersby inadvertently bump the same and thus deflect the sign from its usual orthogonal position.
[0012] Accordingly, a coil deflection spring, a torsion spring, or a flexible resilient tongue is provided to contribute the flexibility needed relative to the display and its fixedly mounted battery pack. Electrical leads proceed through the tongue, spring, or articulative pivotal joint incorporating the torsion spring, so that electrical connection is always maintained between the battery pack and the sign whatever the temporary disposition of the frame of the device. Perforated ears and a pin element positioned therethrough are designed to releasably secure advertising cards within the frame of the display as well as serve other functions. The circuit board is preferably U-configured so as to provide for a convenient receptacle and the support for cards to be inserted in the frame and within the circuit board. The battery is maintained outside of the frame and its advertising display, and is proximate the mounting of the unit to external structure. This mounting is preferably adjustable but may be fixed and secure so as to eliminate the chancing of inadvertent dislodgment of the batteries, or its case. Of prime importance, and whether an articulative or pivotal joint is incorporated or some type of tongue, whether resilient and/or spring, the electrical connectors from the battery support maintain continuous communication via the tongue or spring, etc. whereby to facilitate continuous connection to the circuit board or other lighting circuit of the frame. In the above manner the frame of the device is made free of the battery pack so that it can insure a slim-line design and be functional bi-directionally at opposite sides of the frame as well as be flexible.
[0013] Another aspect of the present involves a tapered sign display having a relatively small section at a proximal end of the sign display and a relatively tall section at a distal end of the sign display. The tapered frame portion of the sign display is mounted to a battery pack oriented to coincide with the horizontal plane of the shelf to which the sign display is attached. As such, the sign display creates minimal interference with access to storage areas above and below the shelf.
[0014] Still another aspect of the present invention involves a resilient flexion joint interconnecting the sign display and the mounting mechanism for the sign display. The flexion joint allows for resilient movement of the sign display in side-to-side directions and in up-and-down directions.
[0015] Yet another aspect of the present invention involves an adjustment mechanism that allows the orientation of the sign display to be adjusted. That is, the presentation angle of the bi-directionally observable sign can be changed as desired.
[0016] Another aspect of the invention involves mounting a pair of lights within the tubular frame members of the sign display, and mounting respective parabolic reflectors at opposite ends of the tubes for illuminating the tubular frame portions of the sign display.
[0017] In view of the foregoing, it is a principal object of the present invention to provide a new and improved advertising display device.
[0018] A further object is to provide an advertising display device carrying its own battery pack and being suitable for attachment to the molding of a merchandise shelf, to the transparent door of a refrigerator or freezer, and so forth.
[0019] A further object is to provide a device having an articulative pivotal joint suitably spring-biased to provide a restoring force for the device frame to return the same to orthogonal projection subsequent to inadvertent bumping or displacements by customers, shopping carts, and the like.
[0020] An additional object is to provide a battery pack or battery holder mount for outwardly projecting display signs, wherein the battery pack mount includes the electrical connections which are maintained with the lighting circuit of the sign provided, even though such sign may be temporarily displaced from its intended orthogonal position.
[0021] A further object is to provide a means for securing cards in display signs, wherein the structure provided may also serve as a tag- or other sign-support.
[0022] Still another object of the invention is to provide a sign display that minimizes impedance with respect to access to shelf areas adjacent the sign display.
[0023] Another object of the invention is to provide an adjustment device for changing the presentation angle of the sign display.
[0024] Yet another object of the invention is to provide a sign display that is resiliently moveable in the side-to-side directions as well as the up-and-down directions.
[0025] Still another object of the invention is to provide a sign display that includes an integral power source aligned to correspond with the shelf area to which the sign display is attached.
[0026] Another object of the invention is to provide a sign display that minimizes the number of light sources used in connection with the sign display.
[0027] Still yet another object of the invention is to provide a sign display that renders the shelf to which it is attached a primary shelf in terms of customer attention and focus.
[0028] Other objects, features, and advantages of the present invention may best be understood by reference to the following detailed description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Preferred embodiments of the invention are described below with reference to the accompanying drawings:
[0030] [0030]FIG. 1 is a fragmentary perspective view of a shelf incorporating the display device of the present invention.
[0031] [0031]FIG. 1A is an enlarged fragmentary detail of a corner of the display device of FIG. 1 wherein the same contains a single card receiving slot.
[0032] [0032]FIG. 2 is an enlarged fragmentary elevation taken along the arrow 2 in FIG. 1.
[0033] [0033]FIG. 2A is a cross-sectional detail taken along the arcuate lines 2 A- 2 A in FIGS. 2 and 11, illustrating that the attachment construction of the display device may be modified so that the same can be adapted for direct attachment to the front panel of the glass door of a display cabinet a fragmentary detail of a portion of which is shown.
[0034] [0034]FIG. 3 is a vertical section taken along the line 3 - 3 in FIG. 2.
[0035] [0035]FIG. 4 is an elevation taken along the arrow 4 in FIG. 1.
[0036] [0036]FIG. 5 is a vertical transverse section taken along the line 5 - 5 in FIG. 4.
[0037] [0037]FIG. 6 is an enlarged section detail taken along the lines 6 - 6 in FIG. 4.
[0038] [0038]FIG. 7 is a schematic diagram of a representative electrical circuit that can be employed in conjunction with the subject advertising display device.
[0039] [0039]FIG. 8 is similar to FIG. 4 but illustrates this time that the display device can contain in its frame directly the electrical circuit means including its battery.
[0040] [0040]FIG. 9 is an enlarged fragmentary section taken along the line 9 - 9 in FIG. 8.
[0041] [0041]FIG. 10 is an enlarged vertical section taken along the line 10 - 10 in FIG. 8.
[0042] [0042]FIG. 11 is a perspective view of a conventional display cabinet, but with the same having the display device of the invention attached to the cabinet's transparent door.
[0043] [0043]FIG. 12 is a fragmentary side elevation, shortened horizontally for convenience of illustration, of another embodiment of the invention illustration usage of a horizontal battery case which is part of the mount of the device, and incorporating a coil-spring tongue or extension connected to the device frame, carrying electrical leads to the circuit of the frame, and lending flexibility to the structure.
[0044] [0044]FIG. 12A is an enlarged fragmentary cross-section, taken along the line 12 A- 12 A in FIG. 12, illustrating circuit-board insertion-receipt of the advertising card employed.
[0045] [0045]FIG. 12B is a partial end view, taken along the line 12 B- 12 B, illustrating the slot receiving the advertising card for positioning within the frame of the device.
[0046] [0046]FIG. 13 is an enlarged horizontal section, taken along the line 13 - 13 in FIG. 12, illustrating the battery pack or holder and its mounting to a display shelf and its flexible securement to the display sign.
[0047] [0047]FIG. 14 is a side elevation of another embodiment of the invention.
[0048] [0048]FIG. 14A is an enlarged fragmentary cross-section taken along the line 14 A- 14 A in FIG. 14.
[0049] [0049]FIG. 15 is a vertical transverse section taken along the line 15 - 15 in FIG. 14.
[0050] [0050]FIG. 16 is an enlarged fragmentary top plan taken along the line 16 - 16 in FIG. 14.
[0051] [0051]FIG. 16A is a longitudinal vertical section taken along the line 16 A- 16 A in FIG. 16.
[0052] [0052]FIGS. 17 and 17A are essentially identical to FIGS. 16 and 16A, respectively, but illustrate a re-arrangement of conductive leads to accommodate single, centralized, screw-attachment placement.
[0053] [0053]FIG. 18 is a top plan of a circuit board which may be used in the frame of the device to power its lights.
[0054] [0054]FIG. 19 is a schematic of one of several electrical circuits which can be used in powering the lights of the advertising display sign.
[0055] [0055]FIG. 20 is an isometric view of an alternative embodiment of a sign display apparatus according to the present invention.
[0056] [0056]FIG. 21 is a right side elevation view, partly in section, of the sign display apparatus of FIG. 20.
[0057] [0057]FIG. 22 is a top view of the sign display apparatus of FIG. 20.
[0058] [0058]FIG. 23 is a sectional side elevation view, taken along the line 23 - 23 , of FIG. 22.
[0059] [0059]FIG. 24 is an exploded isometric view of the mounting bracket portion of the sign display apparatus of FIG. 20.
[0060] [0060]FIG. 25 is a sectional view, taken along the line 25 - 25 , of the display frame portion of FIG. 23.
[0061] [0061]FIG. 26 is a sectional top view of the power source housing and attachment bracket, taken along the line 26 - 26 of FIG. 20.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0062] In FIG. 1 advertising or merchandising display device 10 comprises a panel 11 , a resilient flexible tongue 12 integral therewith, and a mounting bracket or clip 13 . The panel 11 has a peripheral edge 14 which is contiguous with frame portions 15 at opposite sides of the panel, the frame portions comprising respective peripheral margins 16 at opposite sides of panel 11 . Panel 11 includes also a central portion or partition 17 , from which tongue 12 extends, that serves as a backing for a pair of display cards 18 , by way of example, which may be contained in respective pockets 19 and 20 in panel 11 . Small interior detents as at 20 A can be employed to aid in keeping the advertising cards in place. The tab portion or tongue at 12 is designed to be flexible and may be comprised of a coil spring, a resilient, flexible metallic rubber or resilient plastic member, and so forth, this to insure that any jarring of the panel as produced by the movement of a shopping cart will not damage the display device but will rather allow it to give, in the direction of motion of the cart, such that when the cart passes, the display device will spring back to its normal, perpendicular condition relative to the shelf edge of the display shelf.
[0063] The display shelf 19 is customarily made of metal and has a forward lip 20 which is vertical in orientation. The lip 20 serves as a backing for channel or edge molding 21 . The channel 21 includes upper and lower channel slots 22 and 23 , each of which receive a respective foot portion 24 and 25 of upper and lower legs 26 and 27 . Legs 26 and 27 form integral portions of, and comprise flanges of the composite mounting clip 13 . Battery container 28 is secured to tongue or tongue portion 12 by any conventional means and is also made integral, preferably, with mounting clip 13 . The battery container 28 is shown in greater detail in FIG. 6 wherein a nine volt battery, by way of example, is included at 29 , having its battery terminals 30 and 31 engaging electrical connections 32 and 33 , respectively, of the battery housing or container 28 . The left end 28 A of battery container 28 is closed off excepting for a central aperture 34 , designed to receive an implement such as a pencil 35 which can be used to eject the battery 29 from its container 28 in the direction of arrows 36 and 37 . A series of screws or rivets 38 can be employed to secure the channel 21 directly to the front lip or portion 20 of the display shelf 19 . FIG. 1 thus shows the display shelf as containing a series of cans or other containers at 39 , the display device 10 being employed to draw the attention of shoppers to particular specials or other advertising information relative to such goods at 39 .
[0064] Comparison of FIGS. 1 and 4 indicate that different types of signs may be employed concurrently in the respective forward and rear pockets 19 and 20 of the display device, see also FIG. 3.
[0065] A circuit which may be employed in the display device 10 is shown as circuit 39 in FIG. 7. The same includes battery 29 and, with the same, flasher control circuit 40 as well as a series of lights 41 such as parallel connected LEDs (light emitting diodes). A push button on/off switch 42 is preferably included in the circuit, see FIG. 7 and also FIGS. 1 and 10. An optional way of including the battery in the structure is shown in FIG. 8, wherein a disc-type battery 29 A is simply dropped into slot 43 , engages electrical connections 44 and 45 leading to the lighting circuit, and wherein the slot 43 is permissibly covered by a cover 46 that is hinged or pivoted at 47 in FIG. 8. The inclusion of the battery at 29 A in FIG. 8, corresponding to battery 29 in FIGS. 6 and 7, will this time power the circuit, leaving the mounting clip 13 A, corresponding to mounting clip 13 in the other figures, free of battery inclusion; instead the legs and feet may be designed simply to spring outwardly, as is also the case with mounting clip 13 , to engage the upper and lower channel portions 48 and 49 of channel 21 , see FIGS. 1 and 8. For most type of grocery shelves that are presently used, and which do include, generally, the channel 21 , then the upper and lower flanges of the mounting clip 13 , comprising upper and lower legs 26 and 27 with their respective feet, will be made resilient such that the legs can be depressed inwardly so that the outer ends of the feet can slip past the upper and lower lips of the channel, this such that these legs can spring outwardly, with the feet engaging slots 22 and 23 .
[0066] If desired, the clip and the battery container, with an exposed portion of the tongue 12 , may be plastic encased for protection purposes.
[0067] [0067]FIG. 1A illustrates that panel 11 A, corresponding to panel 11 in FIG. 1, may include simply a single slot 50 that can receive a display card 51 containing advertising indicia on both sides, by way of example.
[0068] The several lights 41 , 52 may comprise, again, light emitting diodes or LEDs, or any other type of light. Included is the concept of employing HID (high intensity discharge) lights which customarily comprise U-shaped tubes having suitable terminal and filled with xenon gas. Other types of gases such as argon, etc., may be employed. Typical xenon HID lights may be employed and are shown at 52 A in FIGS. 8 and 9. These, or other lights can include parabolic or other concave reflectors as at 53 , which may be either integrally formed with the panel 11 or comprise separate elements tending to concentrate light emissions from the various light elements. The lights themselves are preferably electrically connected together in parallel and, to prolong battery life, and on/off switch as at 42 can be employed. In the structure shown it is preferable that there be two pockets on either side of the central portion of the panel; these pockets contain their respective cards which can be inserted from the tongue or clip side of the device. The tongue, or tongue tab-portion 12 , is bendable and resilient so that the cards are not exposed to inadvertent vandalism or withdrawal by young shoppers.
[0069] It will of course be understood that the device of the present invention, see the fragmentary cross-sectional view of FIG. 2A, may be used in conjunction with display shelves where the shelves themselves are close to but separated by passersby by means of a glass or plastic door 53 of a refrigerated display cabinet 54 . Cabinet 54 , see also FIG. 11, thus has door 53 which is provided with door knob 61 and hinge mounts 62 secured to the cabinet proper in a conventional manner. The cabinet may include shelves 55 and 56 , and the display device 10 this time includes a plastic or even a metal channel length 57 that can simply be glued or otherwise secured at surface 58 , see also FIG. 2A, to the door 53 . Accordingly, the display device will highlight the contents of the cabinet, yet the door can be opened in customary fashion so that the shopper achieves easy access to the shelves.
[0070] Where the battery and battery container form a portion of or are contained by the mounting clip 13 and the same made integral with tongue, tongue or tab-portion 12 , then it is preferred that the electrical wire leads from the battery as at 59 and 60 , see FIG. 4, be actually encased in the tongue 12 . In this way the wire leads are protected from passersby; yet, their nature permits their flexing with the tab portion or tongue in response to inadvertent movement of display device 10 .
[0071] Accordingly, what the present invention offers is an at-or-proximate shelf merchandising display device which is illuminated, battery powered, and which serves to draw attention to a variety of store goods. The battery is either self-contained in the panel of the display device or is encased within the clip used to mount the flexible tongue of such device to a forward lip channel associated with a given store shelf.
[0072] Rather than, or in addition to plural lights, the subject advertising panel may include battery powered, electrically energized alpha-numeric, liquid crystal or other display indicia, as is conventional with various battery-powered readouts in watches, etc. on the market. Again, the invention is suitable not only for shelves per se, but also for frozen food cabinets, refrigerators, freezers and the like.
[0073] In FIG. 12, an advertising display device 63 is shown and includes a frame 64 having outer edge 65 and rear and front rectangular frame margins 66 and 67 , these respectively being disposed on opposite sides of the frame. Such margins form opposite windows 68 which display the faces of one or more advertising cards 69 . The frame 64 can include an electrical circuit 70 , as before, which is coupled to and electrically powers the several display lights 52 and may take the form of electrical circuit board 102 in FIG. 18.
[0074] It is noted that the frame 64 includes a slot 71 serving as an admittance slot relative to card insertion of card 69 . The interior slot formed by the inner edges of circuit board 102 forms a support receptacle for card 69 . The light powering electrical circuit 70 may include electrical leads 59 and 60 , see FIG. 1, which pass through a new design of tongue 72 . The latter is formed of a flexible resilient sheath 73 which encases deflection restoring coil spring 74 . Spring 74 is seated at its opposite end turns 75 and 76 to and within recesses 77 and 78 of battery case 79 and frame 64 , respectively. Again, the wires 59 and 60 project through the tongue, i.e., through the interior of spring 74 to connect to the electrical circuit 70 powering lights 52 . This will be in the same fashion in connection with the electrical circuit shown in the embodiment of FIG. 1, etc. Battery case 79 may include an end aperture 80 for receiving a battery push-out tool such as pencil 35 in FIG. 6. Optional to this of course may be included a battery rejection spring within battery case 79 for enabling a battery retrieval. The inner circuit 81 of battery case or holder 79 includes a pair of conductor strips 82 and 83 which are electrically connected to leads 59 and 60 . Conductive strip 82 leads to battery end contact 84 which is secured at 85 to the battery case in a manner conventional with battery case constructions. Conductive strip 83 is connected to a conductive threaded ring 86 at the remaining end of the battery, and a plug or cap 87 is provided with a contact 88 and a conductive strip 89 leading to matching conductive threaded ring 90 . Accordingly, insertion of batteries 91 and 92 within the cavity 93 of the battery case, and the securement of the cap 87 , produces an electrical contact circuit and hence an electrical energy supply circuit, via the battery and its conductive strips to electrical circuit leads 59 and 60 .
[0075] Mounting clip 93 can be designed similarly to clip 13 in FIG. 2 and, in any event, will be secured by attachments 94 to battery case 79 . The clip may be designed to be resilient, whereby the up-turned ends thereof 95 and 96 will be releasably and selectively received into the upper and lower recesses of channel molding 97 that corresponds to molding 21 in FIG. 1. Molding 97 of course will be secured in the usual manner to shelf 98 of any description which corresponds to shelf 19 in FIG. 1. In the preferred form of the invention, the mounting clip 93 will be locked in place relative to the channel molding. This will be accomplished by the locking structure shown in FIG. 14 whereby the securement of the mounting clip relative to the channel molding is made permanent or is of a semi-permanent character. The securement of the channel molding 97 to the outer-shelf edge may be effected by attachment 99 .
[0076] Accordingly, FIGS. 12, 12A, 12 B and 13 illustrate the incorporation of a horizontal battery case with contained batteries with the same being supplied an electrical circuit leading through a tongue or extension such as, this time, a coiled deflection-restoring spring 74 , to the electrical circuit of the frame 64 of advertising display device 63 . What is accomplished, therefore, is the provision of a battery pack, i.e., case and batteries, which is separate from the frame proper, but constructed for selected mounting to a shelf molding. More importantly, the leads powered by the batteries in the case project through the tongue, i.e, this time through the spring 74 and its protective sheath, to connect to the electrical circuit of the device. An on-off switch may be provided for the electrical circuit if desired, and in accordance with the teaching of the prior figures.
[0077] [0077]FIGS. 14, 14A, 15 , 16 , and 16 A, with FIGS. 18 and 19 constitute another embodiment of the invention. However, other than being U-shaped to accommodate insertion and support for card insertion in the frame, the circuit board of FIG. 18 and its representative circuit as shown in schematic form in FIG. 19 are strictly conventional and may take any one of a number of forms, familiar to all skilled in the art. Representations as inverters U 1 and counter U 2 . VCC (voltage common cathode) connection is had at the customary points for the circuit components. LED light positioning, D 1 -D 20 , for lights 52 , is also illustrated. Standard resistors are utilized at R 1 , R 2 as well as capacitor C 1 , all selected in accordance with conventional established design procedures. The particular circuit design selected for the circuit board forms no part of the invention.
[0078] [0078]FIGS. 17 and 17A illustrate yet another embodiment of the advertising display device that is closely similar to that shown in FIG. 14, e.g., but illustrates certain minor modifications.
[0079] In FIG. 14 the advertising display device 100 is shown to include a frame 101 that is interiorly provided with a circuit board 102 , having conventional elements as seen in circuit 103 in FIG. 19, but which will be encased within the frame to supply electrical power therefore to the several lights 52 and, additionally, provide a slot 104 for the reception of advertising card 105 . Where desired, the frame 101 may be constituted by separate halves 106 and 106 A which can be secured together by male, female connectors 107 , 108 , by screws, or by other means. Frame half 106 A can be integral with body 137 . Card 105 is designed to slip into end slot 109 which can be similar to slot 71 in FIG. 12B. A tag 110 may be one of several provided, the same incorporating an aperture 111 which receives a hook-shaped pin 112 . This pin proceeds through apertures 113 and 114 of ears 115 , protruding outwardly on both sides of the frame. Accordingly, pin 112 is operative not only to support “special” or other tags, for promotional purposes, but also releasably secures the card 105 within the frame of the advertising display device. The shelf 98 in FIG. 14 is provided with channel edge molding 97 A, corresponding to channel molding 97 in FIG. 12.
[0080] [0080]FIGS. 16 and 16A illustrate that the embodiment introduced by FIG. 14 includes a fixed securement member 116 and also a sliding securement member 117 . The sliding securement member 117 includes a central aperture 118 having a threaded metal insert 119 that receives adjustment screw 120 . Access to adjustment screw 120 is had through the bore or aperture 118 by an elongated screw driver, Allen wrench fitting or the like. Channel edge molding 97 A is also seen. Thus, as to member 119 , the same provides a locking mechanism for locking the entire display device 100 in position by simply tightening down on the screw 120 , which is recessed to be tamper-proof. Member 117 may be configured as shown in FIG. 16 with outer ribs 121 , 122 . Therefore, the sliding securement member is retained in slide disposition by the undercut slots or grooves 123 and 124 as the same is adjusted up and down by screw 120 . FIG. 16A illustrates that the fixed securement member 116 includes an interior circular cavity 125 which receives serially connected batteries 126 and 127 . A battery spring 128 serves to retain the batteries together and also provides electrical contact to conductive strip 129 which leads to lead 136 of the electrical circuit powering lights 52 . Correspondingly, battery spring 130 is supplied to the cap member 131 and connects to conductive strip 132 which leads to spring 133 . Spring 133 in turn is connected to conductor strip 134 connected to lead 135 which is associated with the electrical lighting circuit of the display sign. Thus, the ground and VCC (power) lines, see FIG. 19, will be coupled to the electricity supply leads 135 and 136 .
[0081] Body 137 forms an extension of and moves with frame 101 and includes a recessed seat 138 which accommodates the bearing engagement of end 139 of member 116 . The raised boss 140 is recessed to provide for the battery spring 128 . Accordingly, and relative to the engagement of fixed securement member 116 with body 137 , it is seen that the latter can be rotationally displaced about pivot access R in accordance with temporary deflections of the frame as occasioned by inadvertent impact by passengers or carts in the direction of arrows S and T in FIG. 16. More will be said about this in conjunction with the return torsion spring feature of the invention at a later point.
[0082] At this point it is important to note the cap member 140 A and its provision with electrical current conducting battery spring 130 in the latter engagement with batteries 126 and 127 . Cap member 140 A likewise includes the spring 133 as previously mentioned which provides for electrical connection between conductive strip 132 and strip 134 coupled to lead 135 . The depending portion 142 of cap member 140 A is illustrated and additionally serves to hold down and hold in place the batteries 126 and 127 . Importantly, see FIG. 16, the upper portion 143 of cap member 140 A includes a circularly arcuate enlarged major recess 145 and, contiguous therewith, the arcuate minor recess 146 . These are seen in both FIGS. 16 and 16A. The arcuate major recess or travel path 145 accommodates the movement of the outwardly turned extremities 147 and 148 of circular torsion spring 151 as the sign is laterally deflected according to forces S and T in FIG. 16. Shoulder stop 149 and shoulder stop 150 respectively retain the remaining end of the torsion spring 151 . Upstanding pins 152 and 153 co-act with the torsion spring and are upstanding from fixed securement member 116 . Screws 155 and 156 are provided in FIG. 16 to retain the cap member 140 A in position. Thus, these screws will be threaded into apertures, not shown, positioned in body 137 .
[0083] The remainder of the operation of the embodiments shown in FIGS. 14, 16 and 16 A is as follows: The batteries 126 and 127 with their electrical circuit elements, comprising springs 128 and 130 and conductive strips before mentioned leading to leads 135 and 136 , supply power to the circuit board in the frame of the display device. The apparatus is assembled as heretofore indicated, with cap member 140 A finally being positioned in place and fixed to the frame and screws 155 and 156 tightened.
[0084] In referring to FIG. 16, an inadvertent and temporary deflection in the direction of, e.g., arrow S will produce a clockwise rotation of the sign about axis R. This is simultaneously accompanied by a rotational displacement of cap member 140 A, and hence of its shoulder stops 149 and 150 . The upstanding pins 152 and 153 , upstanding from fixed securement member 116 , are stationary, however, relative to the shelf edge molding, so that there will be a temporary torsional tightening of the spring by one of the pins 152 , 153 , depending upon the direction of frame displacement and thus producing a potential restoring force in the spring. Once temporary pressure is relieved relative to arrows S and/or T, then the spring will operate against its associated pin 152 , 153 to restore the sign to orthogonal relationship relative to the shelf. It is important to note that the pivoting functioning is accomplished proximate the battery case enclosure and that the unit may be clamped to the molding strip, remain stationary, and yet provide for the flexibility and circuit connection needed for the sign proximate the battery enclosure. The display device 100 A in FIGS. 17 and 17A is essentially identical with that shown at 100 in FIGS. 14, 16 and 16 A, but with the following exceptions. A single screw 155 A is employed to secure cap member 140 A, corresponding to cap 140 in FIG. 16A, to the body 137 of the unit. Conductive strips 170 and 171 this time are secured to the spring 130 , see FIG. 16A, and are angulated in dog-leg configuration to connect at 172 to the electrical circuit of the sign. In this manner but a single screw can be used at 155 , can be centered, and the electrical circuit required, with its connections, still be supplied. Metal conductive pin 173 may be employed at the point indicated in FIG. 17A to complete the circuit.
[0085] Hence, what is provided in this invention are a plurality of embodiments of advertising display signs having sufficient flexibility to allow for a restoring force and yet temporary relief for inadvertent forces acting on the sign. Furthermore, the several embodiments illustrate that the display sign can be releasably or securely engaged with the molding strip of a store shelf, and a battery case supplied at the mount for powering the sign. In a preferred form of the invention the battery case itself incorporates structure whereby to facilitate a pivotal displacement of the sign as may be occasioned.
[0086] At all events, the electrical circuit requirement is met for the displacement sign, whether a spring, a resilient member, or other structure is employed.
[0087] [0087]FIG. 20 shows a particular alternative embodiment of the present invention. Specifically, a sign display 200 for point-of-purchase advertising is shown. The sign display generally includes a frame portion 202 , a power supply housing 204 , and an attachment bracket assembly 206 . A yieldable, resilient flexion joint 208 couples the frame portion 202 with the combined power supply housing 204 and attachment bracket assembly 206 .
[0088] The frame portion 202 is best described with reference to FIGS. 20, 23, and 25 . The frame portion 202 includes a top frame member 210 , a bottom frame member 212 , a proximal frame member 214 , and a distal frame member 216 . In one embodiment, the frame portion 202 is generally configured such that the proximal frame member 214 defines a relatively small proximal sign segment 218 and the distal frame member 216 defines a relatively large distal sign segment 220 . The relatively small sign segment 218 provides for substantially unrestricted access to shelf areas above and below the sign display, while the relatively large distal sign segment 220 provides ample sign surface area for effective point-of-purchase advertising.
[0089] The distal frame member 216 further defines a slot 222 for inserting advertising materials 224 , such as a rigid paperboard or the like, into operative position within the sign display 200 . The slot 222 is sized to accommodate the largest vertical dimension of the advertising material 224 . It should be understood that the advertising material 224 may comprise a substantially opaque material such as paperboard, cardboard, paper, or like material. Alternatively, the advertising material 224 may comprise a partially transparent material (e.g., polycarbonate or glass) with specific advertising indicia affixed thereon. As yet another alternative, the advertising material 224 may comprise a series of sheets, such as a pair of transparent sheets of material (e.g., glass or polycarbonate) and an opaque sheet of material positioned in between. Still another alternative embodiment may include a substantially transparent material (e.g., glass or plastic) with indicia provided on at least one surface of the transparent material.
[0090] In the embodiment shown in FIGS. 20 - 23 , the shape of the advertising material 224 is substantially pie-shaped or triangularly shaped with a relatively short vertical dimension provided adjacent the small proximal segment 218 and a relatively tall vertical dimension corresponding with the large distal segment 220 of the sign display 200 . Indicia provided on the advertising material 224 may require that the orientation of the sign be adjusted to a particular presentation angle β (FIG. 21). To adjust the presentation angle β, the attachment bracket assembly 206 includes a worm gear assembly 226 (FIGS. 23 - 24 ) specifically comprising a stationary gear 228 having a plurality of teeth and a rotating adjustment screw 230 having a plurality of threads 232 . The threads 232 rotate through the teeth of the stationary gear 228 to move the frame portion 202 through a plurality of presentation angles until the desired angle β is achieved. The rotatable adjustment screw 230 includes a head 234 into which an adjustment device, such as a straight-slot screwdriver, can be inserted to adjust the presentation angle. The presentation angle is preferably set to orient the advertising material in a manner that will be easy for a purchaser to read.
[0091] The attachment bracket assembly 206 still further comprises a mounting base 236 , formed by two mirror halves 236 A and 236 B. A sliding block 238 is slidably mounted between the halves 236 A and 236 B. An upper clip 240 is mounted to the sliding block 238 . A lower clip 242 is mounted to the base 236 so as to be inserted through slots created by a tongue member 244 (FIG. 24). A rotatable adjustment screw 246 is disposed between the tongue member 244 and the sliding block 238 . Rotation of the screw 246 moves the sliding block 238 relative to the base 236 to adjust the spacial relationship of upper clip 240 and lower clip 242 for securing or releasing the sign display from a shelf or other advertising area. As the sliding block 238 moves away from tongue member 244 , the upper clip 240 and lower clip 242 lock into an attachment bracket associated with the shelf or other display structure. As shown in FIGS. 20, 22, and 24 , a pair of sidewalls 248 are mounted to the base members 236 A and 236 B to prevent lateral displacement of the power supply housing 204 relative to the attachment assembly 206 . The first base member 236 A is secured to the second base member 236 B by means of conventional fasteners 250 . The sidewalls 248 include male posts 249 inserted into corresponding apertures 251 (only one shown in FIG. 24) in the base 236 . The posts allow articulation of the frame portion 202 relative to the mounting base portion 206 upon movement of the adjustment screw 230 .
[0092] With reference to FIGS. 22, 23, and 26 , the power supply housing 204 comprises a main compartment structure 254 and an end cap 256 threadedly received by the main housing structure 254 . Conventional batteries 258 are held within the power supply housing 204 . Lead wires 260 extend from the power supply housing through an opening 262 formed in the main housing structure 254 . The lead wires supply power to the light display associated with the frame section 202 . The lead wires are protected by a yieldable, resilient flexion joint 208 . As shown in FIG. 26, the flexion joint more specifically comprises a resilient spring-bias member 264 surrounded by a rubber boot 266 . The boot 266 allows the resilient bias member 264 to yield and bend while protecting the lead wires 260 . Mounted within the proximal section 218 is the circuitry 270 used in illuminating the frame section 202 . The circuitry 270 may comprise any conventional circuitry to illuminate light sources 272 . The circuitry may provide differentiating illumination for the light sources 272 , alternating the supply of power to the light sources 272 , or any other desired result. The light sources 272 are provided to direct light through the upper frame section 210 and the lower frame section 212 . A pair of parabolic mirrors 274 are mounted within the upper and lower frame sections 210 , 212 , respectively, to provide enhanced illumination within the tubular areas. The frame sections 210 , 212 are preferably made of a translucent material so that light is emitted to catch the attention of shoppers. A benefit of the present invention is that with the illumination as proposed, only two light sources are required to fully illuminate the top and bottom frame sections 210 , 212 .
[0093] With reference to FIG. 25, the frame portion 202 is formed by joining a first frame half 202 A and a second frame half 202 B. A slot is formed between the two frame halves which enables the sign 224 to be inserted therein, as shown in FIG. 20.
[0094] In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not to be limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. | A lighted flexible display device or sign, useful for advertising purposes, and having a battery supply mount. The display device herein is a lighted display and is constructed to be flexible in the presence of inadvertent bumping or deflection thereof. The mounting is resilient such that, when the deflecting force is removed, the sign springs back to its normal lateral position. The mount for the display device includes a battery supply, with such supply being electrically connected to the electrical circuit of the sign proper. This is accomplished by means of electrical leads passing through a deflection restoration spring, by such leads passing through a resilient tongue, or with connectors used in a spring-biased pivotal construction for connecting the battery supply to the electrical lighting circuit of the sign. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of PCT Application PCT/US96/12160, filed Sep. 12, 1995, designating the United States, which claims priority from South African application no. 94/0711, filed Sep. 12, 1994, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to a process for treating a liquid. It also relates to a process for recovering citric acid.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided a process for treating a liquid, which process comprises: (a) subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step; and (b) obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution.
In other words, there is a greater degree of rejection of the less desirable component than of the citric acid in the filtration step. The nanofiltration will normally involve contacting the liquid with a nanofiltration membrane. Nanofiltration will naturally also separate the citric acid from any component with a molecular weight which is significantly greater than that of citric acid.
The molecular weight or relative molecular mass of the less desirable component may be within 20% of that of citric acid. For example, the molecular weight of the less desirable component may be within 10%, and even within about 7%, of that of citric acid. In other words, the molecular weight of the second component may range from 0.8 MW-1.2 MW, e.g., 0.9 MW-1.1 MW, or even about 0.93 MW-about 1.07 MW, where MW is the molecular weight of the citric acid.
The Applicant believes that the process will have particular, but not necessarily exclusive, application in the treatment of fermentation broth to separate citric acid present therein as a fermentation product from residual glucose and/or fructose, thereby recovering the citric acid. It has been found that, with the process of the invention, the citric acid can be separated from residual glucose and/or fructose as well as other impurities such as medium and higher molecular weight by-products such as peptides and polysaccharides, produced by fermentation microorganisms, and which can be undesirable. In other words, the process has specific application in the recovery of citric acid from a fermentation broth, particularly from a clarified citric acid fermentation broth.
The clarified citric acid fermentation broth can typically be that obtained by fermenting a carbohydrate feedstock to produce citric acid-rich fermentation broth and waste solids, and separating the broth from the solids.
Citric acid has a similar molecular mass to glucose and fructose and can preferentially be separated from glucose and/or fructose in the process according to the invention, as a result of its greater permeability through the nanofiltration membrane as compared to that of glucose and/or fructose.
The filtration step may be carried out at a concentration of the citric acid in the broth of 5%-30% by mass, preferably 10%-20% by mass, and the nanofiltration may be carried out at a temperature of 10° C.-100° C., preferably 20° C.-50° C. The pressure drop across the nanofiltration membrane will depend on the nature of the membrane and one the nature of the citric acid and the less desirable component to be separated and can be established by routine experimentation.
The clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange to remove cations, such as potassium and magnesium ions, therefrom.
The process may include further treating the citric acid solution from the filtration step to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, such as sodium citrate.
Thus, the citric acid solution from the filtration step may be purified by anion exchange, e.g., to remove traces of anionic impurities, and/or by contacting it with activated carbon to remove traces of organic matter.
The purified citric acid solution may then be concentrated. This may include treating the solution to obtain solid pure citric acid and residual mother liquor. The concentration may include subjecting the solution to at least one evaporation and crystallization sequence. In particular, the concentration may include passing the solution sequentially through an evaporator; a first crystallizer; a first centrifuge; optionally a dissolution tank, a second crystallizer and a second centrifuge; and producing mother liquor in the first centrifuge and, when present, in the second centrifuge. A portion of the mother liquor from the second centrifuge, when present, may then be recycled to the first crystallizer, while the mother liquor from the first centrifuge is withdrawn. The contacting of the citric acid solution with the activated carbon hereinbefore referred to may instead, or additionally, be effected after the purified citric acid solution has been concentrated at least partially, e.g., after it has passed through the evaporator.
The process may also include: (i) recycling a portion of the mother liquor from the first centrifuge to upstream of the evaporator; and/or (ii) withdrawing at least a portion of the mother liquor from the first centrifuge as a liquid product; and/or (iii) drying and/or granulating at least a portion of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and/or (iv) treating at least a portion of the mother liquor from the first centrifuge, in a recovery step, to recover citric acid for recycle, or citrate salts as product.
When the process includes treating at least a portion of the mother liquid from the first centrifuge in a recovery step to recover citric acid, this citric acid may be recycled to upstream and/or downstream of the nanofiltration step. The treatment in the recovery step may then comprise one of the following: calcium citrate precipitation by adding lime thereto and redissolving with sulphuric acid; solvent extraction of citric acid utilizing a suitable solvent, followed by re-extraction of citric acid from the solvent into water using concentration differences or heating; ion exchange using a resin which selectively adsorbs citric acid, followed by elution; or various types of chromatography.
At least a portion of the retentate from the filtration step may be withdrawn as a liquid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be dried or granulated to obtain a solid citric acid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be treated in a citric acid recovery step, which may then be the same as the citric acid recovery step hereinbefore described, to recover citric acid or a derivative thereof therefrom.
The retentate from the filtration step may be combined with the mother liquor from the first centrifuge for withdrawal as a liquid product and/or for drying or granulating and/or for treatment in a recovery step, as hereinbefore described.
According to a second aspect of the invention, there is provided a process for recovering citric acid, which process comprises subjecting a clarified citric acid fermentation broth to nanofiltration in a filtration step to obtain, as a permeate, a purified citric acid solution.
The clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange as hereinbefore described. The citric acid solution from the filtration step may be treated further to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, as hereinbefore described. The filtration step may also be as hereinbefore described.
The invention will now be described by way of example, with reference to the accompanying simplified flow diagram in FIG. 1 of a process according to the invention for treating a fermentation broth, and with reference to the non-limiting examples.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a flow diagram of a process for treating a fermentation broth.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, reference numeral 10 generally indicates a process according to the invention for treating a fermentation broth.
The process 10 includes a cation exchanger stage 32. A clarified citric acid fermentation broth feed line 30 leads from a fermentation stage (not shown) into the stage 32. A regeneration water/acid flow line 34 also leads into the stage 32, while a waste product withdrawal line 36 leads from the stage 32. A flow line 38 also leads from the stage 32.
The flow line 38 leads to a nanofiltration step or stage 40, with a waste product or retentate withdrawal line 42 leading from the stage 40. A cleaning water/base and diafiltration flow line 41 leads into the nanofiltration stage 40. A filtrate flow line 44 leads from the stage 40 to an anion exchanger 46, with a regeneration water/base flow line 48 leading into the exchanger 46. A waste product withdrawal line 49 leads from the stage 46, while a flow line 50 leads from the exchanger 46 to an activated carbon bed stage 52.
A flow line 54 leads from the stage 52 to an evaporation stage 56, with a steam flow line 58 leading into the stage 56. A condensate line 60 leads from the stage 56. A flow line 62 leads from the stage 56 to a first crystallization stage 64. A flow line 66 leads from the crystallization stage 64 to a first centrifugation stage 68. A flow line 70 leads from the first centrifugation stage 68 to a dissolution tank 72, with a water make-up line 74 leading into the tank 72. A flow line 76 leads from the tank 72 to a second crystallization stage 78, with a flow line 80 leading from the second crystallization stage 78 to a second centrifugation stage 82. A mother liquor recycle line 84 leads from the stage 82 to the crystallization stages 64, 78. A flow line 86 leads from the second centrifugation stage 82 to a drier 88, with a flow line 90 leading from the drier 88 to a screening stage 92. A solid product withdrawal line 94 leads from the screening stage 92.
The second crystallization stage 78 and second centrifugation stage 82 are used to improve crystal quality and are optional; they can be dispensed with, if necessary.
A mother liquor withdrawal line 96 leads from the first centrifugation stage 68.
In a first embodiment of the invention, the line 96 can be routed back to the flow line 50 for recycling a portion of the mother liquor.
In a second embodiment of the invention, the flow line 96 can lead to a suitable liquid product withdrawal stage 98.
In a third embodiment of the invention, the flow line 96 can lead to a drying and granulation stage 100.
In a fourth embodiment of the invention, the flow line 96 can lead to a recovery stage 102. A waste product withdrawal line 104 leads from the stage 102. A citric acid recycle line 106 leads from the stage 102 back to upstream and/or downstream of stage 40.
It will be appreciated that the first, second, third and fourth embodiments described hereinbefore are optional and can be used individually, or a combination of two or more of the embodiments can be used, as desired.
A flow line 108 can, if desired, lead from the flow line 42 to the flow line 96 upstream of the product withdrawal stage 98, the drying and granulation stage 100, and/or the citric acid recovery unit 102.
In use, clarified citric acid fermentation broth, produced in known fashion in the fermentation stage, passes to the cation exchanger 32 where it is contacted with a suitable resin to remove cations such as calcium and sodium ions. If these ions are not removed they would form complexes with the citrate ions and be retained by the nanofilter element in the subsequent filtration stage 40 leading to product losses. The resin bed can be regenerated in known fashion, when required.
The broth then passes to the nanofiltration stage 40 where the citric acid is separated, by contacting the broth with a nanofiltration membrane, from glucose, fructose, and higher molecular weight components in the broth such as protein, residual anti-foaming agents, sucrose, peptides and polysaccharides which thus form the retentate. Smaller molecules as well as some anions pass through the nanofiltration membrane and, together with the citric acid and most of the water, form the permeate. The permeate is thus in the form of a purified citric acid solution in which the ratio or proportion of the concentration of citric acid to that of glucose and fructose is greater than the ratio or proportion of the concentration of citric acid to that of the glucose and fructose in the feed to the stage 40. Thus, in the filtration stage 40, glucose and fructose, which have a similar molecular weight (180) to citric acid (192) are separated therefrom. The permeate from the filtration stage 40 passes to the anionic exchanger 46 where anionic impurities are removed and withdrawn. The resin bed of the anionic exchanger 46 is regenerated in known fashion, when required.
The citric acid containing solution from the exchanger 46 passes to the activated carbon bed stage 52 where traces of organics are removed.
The citric acid solution thereafter passes to the evaporator where it is concentrated, using steam, from a concentration of 15% to 20% by mass citric acid, typically up to about 65% to 80% by mass citric acid. Condensate from the evaporation stage 56 leaves along the line 60. The concentrated citric acid solution passes to the first crystallization stage 64 where crystallization of the citric acid is effected. The stream then passes to the first centrifuge stage 68 where the citric acid crystals are separated from the mother liquor. The citric acid crystals pass into the dissolution tank 72 where they are redissolved in make-up water, whereafter they are recrystallized in the second crystallization stage 78 to improve crystal quality. The make-up water may be obtained from any suitable source, such as process condensate, a dilute citric acid stream, or the like. The stream from the crystallization stage 78 passes to the second centrifugation stage 82 where mother liquor is again removed. The moist crystals pass to the drier 88, with dried crystals passing to the screening stage 92. Dried solid substantially pure citric acid crystals are withdrawn along the flow line 94.
The crystallization stages 64, 78 typically comprise known crystallizers, and will thus include ancillary equipment normally associated therewith such as steam feed/condensate outlet lines, cooling fluid lines, and the like.
Mother liquor from the first centrifugation stage 68 is withdrawn along the flow line 96.
In a first embodiment, a portion of this mother liquor can be recycled to the activated carbon bed 52.
In a second embodiment, at least a portion of this mother liquor can be withdrawn as a liquid product in the stage 98.
In a third embodiment, at least a portion of this mother liquor can be dried and granulated in the stage 100 to obtain a citric acid/carbohydrate solid commercial product.
In a fourth embodiment, at least a portion of this mother liquor can pass to the recovery stage 102. Waste product, e.g., glucose and trace impurities, from the recovery stage 102 is withdrawn, while if pure citric acid is recovered, it may be recycled to upstream or downstream of stage 40; or if citrate salts are recovered, they will be recovered as product. A portion of the retentate from the nanofiltration stage 40 can be routed, by means of the flow line 108, to the stream 96 and then routed to any of the optional stages 98, 100 and/or 102, if desired, to recover residual citric acid or a derivative thereof present in this stream.
In one version of the invention, the recovery stage 102 may utilize calcium citrate precipitation after lime addition; followed by sulphuric acid addition to form citric acid as well as the by product gypsum, to recover citric acid.
In another version, the citric acid in the mother liquor may, in the stage 102, be extracted using a suitable solvent, followed by re-extraction of citric acid from the solvent phase into water using concentration differences or with the aid of heat.
In yet another version, the recovery stage 102 may comprise an ion exchange resin which selectively adsorbs citric acid, with elution of the product into water thereafter taking place.
In yet a further version of the invention, the citric acid recovery stage may comprise various types of chromatography.
The Applicant believes that with the process 10, citric acid can be recovered effectively and at relatively low cost. In addition, it is believed that the process 10 will be relatively simple to operate.
EXAMPLES
The following examples are provided for illustrative purposes, and are not intended to limit the scope of the invention as claimed herein. Any variations in the exemplified methods which occur to the skilled artisan are intended to fall within the scope of the present invention.
Example 1
The process 10 of the invention was simulated theoretically as follows:
Clarified citric acid fermentation broth containing 18.4 weight percent citric acid, can be obtained by fermentating various cultures, such as Aspergillus niger, on a purified carbohydrate feedstock, and filtering off the resultant biomass. The broth leaving the fermenters can contain 0.2% (w/w) unfermented glucose or 0.2% (w/w) unfermented fructose.
The clarified citric acid fermentation broth is then subjected to cation exchange, to remove cations such as potassium and magnesium ions.
The clarified decationized citric acid fermentation broth is then contacted with a nanofiltration membrane, and 80 or more percent of the citric acid transfers to the permeate, which contains up to 18 weight percent citric acid. The permeate also contains the following from the clarified decationized citric acid fermentation broth: a portion of the glucose and fructose, anions, cations, amino acids and sucrose, as well as 80 or more percent of the water. The retentate can be treated in a citric acid recovery step, using the UOP™ Citric Acid Sorbex™ Process (Citrex™), to recover the remaining citric acid.
The permeate from the nanofiltration step can be subjected to anion exchange, to remove traces of anionic impurities, followed by contacting with activated carbon, to remove traces of organics.
The permeate can thereafter be concentrated by evaporation in an evaporator, followed by a first crystallizer, a first centrifuge, a dissolution tank, a second crystallizer and a second centrifuge; with 20% by weight of the mother liquor from the second centrifuge being recycled to the first crystallizer, while the mother liquor from the first centrifuge is withdrawn.
The process can include (i) recycling 25% (w/w) of the mother liquor from the first centrifuge to upstream of the evaporator, (ii) withdrawing 10.0% (w/w) of the mother liquor from the first centrifuge as a liquid product, (iii) drying and granulating 21.6% (w/w) of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and (iv) treating the remainder of the mother liquor from the first centrifuge, together with 80% (w/w) of the nanofiltration retentate, using the UOP™ Citric Acid Sorbex™ Process (Citrex™) process (this process revolves around any one of various chromatographic techniques, such as ion exclusion chromatography, whereby citric acid is separated from the feed stream by selective adsorption onto a solid adsorbent) in a recovery step, to recover citric acid which can be recycled to downstream of the nanofiltration step.
In the Citrex recovery step, which uses a very dilute solution of sulfuric acid as desorbent, the extract can contain, from the feed stream, on a weight to weight basis: 92% of the citric acid, 1% of the glucose and fructose, 1% of the cations and anions, 1% of the amino acids and biomass, negligible sulfuric acid, and 44% of the water from both the feed stream and the desorbent stream. The balance of the above mentioned components report to the raffinate (waste stream).
Example 2
In a simulation of the nanofiltration step or stage 40, laboratory scale tests were conducted on simulated citric acid fermentation broths containing, by mass, 18-19% citric acid, 1% lactose, 0.2% glucose and 0.05% yeast extract. The yeast extract was used to mimic other components normally present in commercial formation broths. Each test was conducted with a pair of membranes, by treating a batch of the simulated broth. Concentrations of each of the components were measured, and the rejections calculated. The results are set out in Tables 1, 2 and 3 (all percentages are on a mass bases).
TABLE 1______________________________________Results of Nanofiltration Test 1Experiment 1 Citric Acid % Lactose % Glucose %______________________________________Feed 18.8 0.88 0.22Permeate - 12.3 0.01 0.03Membrane APermeate - 14.6 0.18 0.09Membrane BConcentrate 29 2.1 0.47______________________________________ Membrane A: Filmtec NF45 membrane obtained from Dow Liquid Separations in the USA or from Dow Deutschland Inc., Industriestrasse, 77836 Rheinmunster, Germany. Membrane B: MPKW MPF21 membrane obtained from Membrane Products Kiryate Weizman Limited, Post Office Box 138, Rehovot 76101, Israel.
TABLE 2______________________________________Results of Nanofiltration Test 2Experiment 2 Citric acid % Lactose % Glucose %______________________________________Feed 18 0.88 0Permeate - 11.4 0.01 noneMembrane APermeate - 11.7 0.05 0.07Membrane BConcentrate 28 1.9 0.38______________________________________
TABLE 3______________________________________Rejections of the two membranesRejectionsexpressed aspercentages Citric acid % Lactose % Glucose %______________________________________Filmtec NF45Test 1 34.6 98.9 86.4Test 2 36.7 98.9 >90MPKW MPF23Test 1 22.3 79.5 59.1Test 2 35.0 94.3 65.0______________________________________
One of the key parameters in nanofiltration is the rejection. For the simulated citric acid fermentation broths, it was expected, according to literature and product information, that membrane rejections would be in the order lactose>citric acid>glucose. However, as can be seen from Table 3, the actual rejection of citric acid was surprisingly found to be lower than that of glucose.
This feature thus provides the basis for a simple and efficient means of separating citric acid from high and medium molecular weight impurities as well as removing most of the residual glucose, in respect of fermentation broth.
It is to be appreciated that, together with the citric acid, other more valuable fermentation products can be separated from the glucose. | A process for treating a liquid comprising subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step. From the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution, is obtained. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of U.S. Provisional Application No. 60/319,122 filed on Feb. 25, 2002.
BACKGROUND OF INVENTION
[0002] The present invention relates to an apparatus and method for debarking logs prior to further processing such as lumber production or production of wood chips.
[0003] Log debarking is typically accomplished using ring debarkers or drum debarkers. In a ring debarker, a log passes through a ring of abrasive or cutting heads which contact the circumference of the log. By necessity, a ring debarker may only handle one log at a time and therefore multiple units operating at high speeds are required for efficient processing of small diameter stems.. As well, ring debarkers are subject to high stresses from the impact of logs propelled at high speed from the log delivery system.
[0004] A drum debarker has a continuously rotating drum which is partially filled with logs (usually from 30 to 40% full by volume) and as the drum rotates, the log burden inside the drum is lifted causing the logs to cascade down and roll back on and impact the logs below. It is this continuously lifting, rotational and impacting/rubbing action of logs on each other that removes the bark as the logs progress down the drum toward the discharge gate. The logs are usually fed into the drum in a continuous stream of groups of logs from an elevated hopper at one end of the drum and slide by gravity into the drum. Although drum debarkers can process large volumes of logs, pretreatment is usually required to achieve acceptable debarking cleanliness when dealing with severe winter conditions (frozen logs) or difficult to debark species.
[0005] Rotary debarkers exist which use rollers having debarking teeth or bars. An example of a rotary debarker is the Fuji King debarker designed by Fuji Kogyo and licensed to CAE in Canada. In this example, the debarker consists of a fixed trough assembly containing a pair of openings to allow the placement of a cylindrical rotor in each opening. The rotors are mounted at their ends on roller bearings and are driven with electrical drives. Mounted on the surfaces of the rotors are debarking plates. The rotors are very tight within their openings and the protruding plates pass through slits in the edges of these openings. Logs and branches typically are fed into the debarker with a transverse chain deck. The deck feeds an infeed hopper that delivers the logs into the trough in the same axis as the rotors. As the furnish enters the debarker, it is impacted by the plates on the surface of the spinning rotors. The contact of these plates begins the removal of bark by first breaking the bond with the fiber at the cambium layer. Additionally, the plates cause the logs to spin about their own axis and move within the trough, contacting the other logs and branches. Bark is abraded from the logs through mutual contact and the striking of the plates.
[0006] The wood fibre debris processor disclosed in co-owned U.S. Pat. No. 5,394,912 (the contents of which are hereby incorporated in its entirety) may also be used as an effective debarker machine. Like the Fuji King debarker, the logs are fed into one end of the apparatus and discharged at the other end, traveling in a direction consistent with their longitudinal axis.
[0007] However, there is a need in the art for rotary type debarker which mitigates the disadvantages of the prior art and which improves upon or provides an effective alternative to the prior art.
SUMMARY OF INVENTION
[0008] The present invention is directed to a rotary debarker and wood fibre processor which may batch process logs and discharge the debarked logs laterally. In its most basic form, the debarker is adapted to accept batches or bundles of logs and to discharge them laterally instead of longitudinally.
[0009] Accordingly, in one aspect of the invention, the invention comprises a debarking apparatus comprising:
[0010] (a) a rectangular bin having two endwalls and two elongate sidewalls;
[0011] (b) a plurality of substantially parallel abrader rotors placed across the bin;
[0012] (c) a plurality of abrader blocks attached to the abrader rotors in a longitudinally spaced manner; and
[0013] (d) wherein one sidewall or a portion of one sidewall may be displaced to release logs held within the bin.
[0014] In one embodiment, the debarker may have a live floor comprising the rotors and abraders and an open bottom where the bark and small debris may accumulate. Alternatively, elongated finger plates may be provided between adjacent rotors. Preferably, there are three or more rotors which are arrayed on an incline such that the rotors are parallel but not on the same horizontal plane. The rotors may be independently rotated to rotate in the same or different directions and at the same or different speeds. The abrader blocks may be fitted with replaceable abrader tips, which may be welded or bolted to the blocks. Various designs of abrader blocks and tips are possible, besides those disclosed herein. The abrader blocks and tips may be aligned parallel to the longitudinal axis of the rotors or may be offset. In one embodiment, the abrader tips may be aligned helically about the rotors.
[0015] In one embodiment, the sidewall may be raised or lowered vertically to release logs. Alternatively, the sidewall may be hinged, either at the top or bottom, to swing outwards. In one embodiment, the sidewall may move vertically and also be hinged.
[0016] A control system is preferably provided to allow remote or electronic control of the debarking process, including dwell time, speed and direction of shaft rotation and other variable parameters of the process. The control system may include a programmable logic controller (“PLC”).
[0017] The debarker may accept logs simply using a grapple loader or a hopper which aligns the logs and directs them into the debarker. Alternatively, a live hood may be incorporated to ensure or assist in log orientation and rotation.
[0018] In another aspect of the invention, the invention comprises method of debarking logs comprising the steps of:
[0019] (a) providing a debarking apparatus including a rectangular bin having two endwalls and two elongate sidewalls; a plurality of abrader rotors placed across a lower section of the bin parallel with the sidewalls; a plurality of abrader blocks attached to the abrader rotors, and one sidewall or a portion of one sidewall may be displaced to release logs held within the bin;
[0020] (b) introducing a batch of logs into the apparatus and rotating the rotors until the logs are substantially debarked;
[0021] (c) displacing the sidewall to discharge the logs laterally.
[0022] The logs may be discharged laterally into a receiving chamber, a conveyor, a step feeder, a quandrant feeder or other transfer mechanism, or a singulation device. The debarker may be portable or rail mounted and used to transport logs within a facility to various discharge points.
BRIEF DESCRIPTION OF DRAWINGS
[0023] The invention will now be described by way of an exemplary embodiment with reference to the accompanying simplified, diagrammatic, not-to-scale drawings. In the drawings:
[0024] [0024]FIG. 1 is a vertical cross-section view of one embodiment.
[0025] [0025]FIG. 2 is a top plan view of one embodiment.
[0026] [0026]FIG. 3 is a front elevation view of one embodiment.
[0027] [0027]FIG. 4 is a vertical cross-section view of one embodiment.
[0028] [0028]FIG. 5 is a top plan view of one embodiment.
[0029] [0029]FIG. 6 is a front elevation view of one embodiment.
[0030] [0030]FIG. 7 is a vertical cross-section view of one embodiment.
[0031] [0031]FIG. 8 is a top plan view of one embodiment.
[0032] [0032]FIG. 9 is a front elevation view of one embodiment.
[0033] [0033]FIG. 10 is a top plan view of one embodiment where one debarker may feed three strander feed decks.
[0034] [0034]FIG. 11 is a front elevation view of FIG. 10.
[0035] [0035]FIG. 12 is a side view of FIG. 10.
[0036] [0036]FIG. 13 is a top plan view of one embodiment.
[0037] [0037]FIG. 14 is a front elevation view of FIG. 13.
[0038] [0038]FIG. 15 is a side view of FIG. 13.
[0039] [0039]FIG. 16 is a top plan view of one embodiment.
[0040] [0040]FIG. 17 is a front elevation view of FIG. 16.
[0041] [0041]FIG. 18 is a side view of FIG. 16.
[0042] [0042]FIG. 19 is a vertical cross-section of a bolt-on style abrader assembly.
[0043] [0043]FIG. 20 is a vertical cross-section of a weld-on style abrader assembly.
[0044] [0044]FIGS. 21, 22 and 23 are top plan views of adjacent showing differing abrader assembly spacing.
[0045] [0045]FIGS. 24, 25 and 26 are perspective views of helical arrangements of the abrader assemblies.
[0046] [0046]FIG. 27 is a schematic view of a multiple shaft arrangement of differing helical arrangements of abrader assemblies.
[0047] [0047]FIGS. 28, 29 and 30 are side views of different embodiments utilizing 3 , 4 or 5 .
[0048] [0048]FIG. 31 is a top view of powered by individual power sources.
[0049] [0049]FIG. 32 is a side view of FIG. 31.
[0050] [0050]FIG. 33 is a side view of a upper finger bar.
[0051] [0051]FIG. 34 is a side view of an alternative live upper finger bar.
[0052] [0052]FIG. 35 is a side view of an alternative embodiment using inter-shaft finger plates.
DETAILED DESCRIPTION
[0053] The present invention provides for a method and apparatus for debarking logs. When describing the present invention, all terms not defined herein have their common art-recognized meanings.
[0054] As shown in FIGS. 1, 2 and 3 , the apparatus comprises a bin ( 10 ) constructed of structural steel which has two end walls ( 12 ) and a closed sidewall ( 14 ) and a discharge sidewall ( 16 ). The bin may therefore have a rectangular horizontal and vertical cross-section. Three rotating rotors ( 18 ) are disposed within the bin along a substantially horizontal plane. In a preferred embodiment, the plane of the three rotors ( 18 ) is inclined downwardly towards the discharge sidewall ( 16 ) and each rotor ( 18 ) is parallel to each other. It is conceivable that non-parallel rotors may be used.
[0055] Logs (L) may be top-loaded into the bin by means of a grapple loader is shown in FIG. 1. However, the means and orientation of loading the logs is not an essential part of the invention. Any means of placing a batch of logs within the debarker is intended to be within the scope of the present invention. In one embodiment, the closed sidewall ( 14 ) may open to permit entry of a batch of logs.
[0056] The discharge sidewall ( 16 ) is hinged along its top edge permitting its bottom edge to swing outwards as illustrated. When the discharge sidewall is opened in that fashion, it is readily seen that logs may be laterally discharged from the bin.
[0057] While size is not a limiting factor of the present invention, bins may generally be 3 to 9 meters long, 3 to 5 meters wide and 3 to 9 meters high. The bins and rotors may be made longer to allow for debarking of longer logs, as necessary. The bins may be made larger to process larger quantities of logs if desired.
[0058] The rotors ( 18 ) each carry a plurality of abrader assemblies ( 20 ) which are spaced along the longitudinal length of each rotor ( 18 ). The abrader assemblies ( 20 ) comprise ring-like projections around the circumference of the rotor and are preferably staggered on adjacent rotors in an alternating interleaved fashion. This arrangement of rotors and abrader assemblies ( 20 ) creates a live floor with gaps. The size of the gaps are governed by the lateral spacing between adjacent rotors as well as the longitudinal spacing of the abrader assemblies along the rotors. As seen in FIG. 3, the bottom portion of the bin is open to receive bark which is removed from the logs and which falls through the gaps.
[0059] Also seen in FIG. 1 are the top fingerplate ( 24 ) and the bottom fingerplate ( 22 ) which are affixed to the closed sidewall ( 14 ) and discharge sidewall ( 16 ) respectively.
[0060] In an alternative embodiment illustrated in FIGS. 4, 5 and 6 , the discharge. sidewall is adapted to slide vertically between open and closed positions. In a further alternative embodiment shown in FIGS. 7, 8 and 9 , the discharge sidewall both slides vertically and is hinged along its top edge.
[0061] As shown in FIGS. 10, 11 and 12 , the debarker may discharge logs laterally directly to a strander feed deck ( 30 ). In one embodiment, the debarker may be mounted to rails or the like to feed a plurality of strander feed decks ( 30 ) installed side by side.
[0062] In another embodiment shown in FIGS. 13,14 and 15 , the debarker may be disposed immediately above a log pond ( 40 ) so that the logs may be laterally discharged directly into the log pond or down a chute ( 42 ) into the log pond.
[0063] In another embodiment, the bin ( 10 ) may enclose two sets of rotors ( 18 ) as may be seen in FIGS. 16, 17 and 18 . Such a double length bin may be particularly suitable for debarking very long logs.
[0064] One embodiment of the abrader assemblies ( 20 ) is illustrated in FIG. 19 and an alternative embodiment is shown in FIG. 20. In either example, the abrader assemblies are affixed to a parent ring (not shown) which encircles the rotor ( 18 ). In FIG. 19, a support ring ( 50 ) having a hexagonal profile is welded to the parent ring and abrader blocks ( 52 ) are then welded to the flat outer surfaces of the support ring ( 50 ). The replaceable abrader tips ( 54 ) are then bolted into the abrader blocks ( 52 ) as shown. In FIG. 20, a circular support ring ( 56 ) comprises a few sections which are welded to parent ring. The abrader tips ( 54 ) are then welded directly to the support ring ( 56 ). In either case, two types of abrader tips ( 54 ) are provided and are alternated about the periphery of the abrader assembly. A primary abrader tip ( 54 A) may typically have three teeth ( 58 ) while a secondary abrader tip ( 54 B) has typically a single tooth ( 60 ). The number of teeth on each of the primary and secondary abrader tips may be varied depending on debarking conditions required or desired.
[0065] The longitudinal spacing between abraders ( 20 ) along a shaft determines the amount of void space in the live floor created by the rotors ( 18 ) and abraders ( 20 ). In FIG. 2 1 , a relatively wide spacing of d=4.5 inches is shown. In FIG. 22, a moderate spacing of d=2.5 inches is shown while in FIG. 23 a tight spacing of d=0.5 inches is shown. The design of this particular variable, and others disclosed herein, in the design of specific debarker in accordance with present invention may be varied for particular conditions and species of wood to be processed with minimal experimentation and trial and error.
[0066] The abrader tips ( 54 ) may be aligned along a rotor such that primary abrader tips and secondary abrader tips are aligned longitudinally, parallel to the rotor axis.
[0067] Alternatively, the primary and secondary abrader tips may be alternated along such a longitudinal axis. In another alternative embodiment, the abrader assemblies are arranged such that the primary and/or secondary abrader tips are aligned helically about the rotor axis as shown in FIG. 23. Tighter helical arrangements are shown in FIGS. 24 and 25. The helical arrangement may follow a right-hand or left-hand helix and both left and right helices may be used in a debarker. In one embodiment shown in FIG. 26, having five rotors, the lower two rotors have left-hand helices while the upper two rotors have right-hand helices. The middle rotor may be either left-hand or right-hand. Alternatively, right and left-hand helices may be alternated from rotor to rotor. As may be appreciated by one skilled in the art, the use of helically arranged abrader tips may promote some limited longitudinal movement of the logs within the bin, enhancing the debarking process.
[0068] The invention is not intended to be limited by the number of rotors ( 18 ) disposed within the bin ( 10 ). In alternative embodiments, three, four or five rotor models may be provided as shown in FIGS. 27, 28 and 29 . Conceivably, the invention could be operated with as few as two rotors and with as many rotors as can practically be fit within a bin. In a preferred embodiment, each rotor is individually driven by an independent power source ( 70 ) which may be a variable speed electric motor, hydrostatic drive or any other suitable power source. In this manner, the direction and speed of rotation of each rotor may be individually controlled and varied to achieve desired results. The power sources are illustrated in FIGS. 30 and 31.
[0069] The upper fingerplate shown in FIG. 32 ensures that logs which roll up against the closed sidewall ( 14 ) do not jam between the uppermost rotor ( 18 ) and the sidewall ( 14 ). In an alternative embodiment shown in FIG. 33, supplementary rotating elements ( 80 ) are provided behind the fingerplate ( 24 ) to allow logs to more easily slide upwards or downwards along the fingerplate. Alternatively, the supplementary rotating elements ( 80 ) may be actively rotated using a power source to encourage upward movement of the logs.
[0070] In an alternative embodiment, the invention may also comprise inter-rotor finger plates ( 90 ) as shown in FIG. 34. These finger plates ( 90 ) fit between adjacent rotors ( 18 ) and the abrader assemblies ( 20 ). The finger plates ( 90 ) have the effect of providing a closed floor apparatus which will tend to retain smaller pieces of wood fibre which would otherwise be rejected through the bottom of the debarker.
[0071] In a preferred embodiment, the apparatus may be controlled by a computer system which controls operating variables in accordance with user settings. The operating variables may include dwell time of logs within the apparatus, speed of rotation of the rotors and direction of rotation of the rotors. In one embodiment, the system may be programmed to initiate a debarking batch by rotating all of the rotors in the same direction with a relatively fast speed. The speed and direction of rotation may then be varied within a single dwell cycle to achieve efficient debarking. The control system may also control the opening or displacement of the discharge sidewall to discharge the logs after a debarking process.
[0072] As will be apparent to those skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the scope of the invention claimed herein. Various features of the invention described herein may be combined in different combinations that those specifically disclosed herein. | A batch debarking apparatus includes a rectangular bin and a plurality of abrader rotors placed across the bin. Log batches are debarked within the bin and discharged laterally through one sidewall of the apparatus. | 1 |
TECHNICAL FIELD
This disclosure relates to heterojunction field effect transistor (HFET) based variable gain amplifiers having variable transconductance.
BACKGROUND
As is known in the art, microwave systems, including microwave radar systems, can benefit from an amplifier whose gain can be adjusted in a predictable manner. For example, Group III-V (such as Gallium Nitride (GaN)) HFET amplifiers used in radars may have oscillation problems under certain conditions (e.g. temperature) due to excessive gain at a given condition (e.g. temperature).
As is known in the art, HFETs generally are formed by providing semiconductor layers of different materials forming a heterojunction. One such layer may be, for example, GaN and the other AlGaN to provide a high-electron mobility transistor (HEMT). The heterojunction supports a two-dimensional electron gas (2DEG) confined in a triangular quantum well (a potential well with only discrete energy values) at the heterojunction. This confinement of the 2DEG leads to quantized energy levels for motion along the channel of the HFET. Electrons confined to the heterojunction of HEMTs exhibit higher mobilities than those in MOSFETs, since the former utilizes an intentionally undoped channel thereby mitigating the deleterious effect of ionized impurity scattering.
As is also known in the art, the gain of a GaN HFET amplifier is set by the HFET transconductance (g m , the change in drain current divided by change in gate voltage) having a value fixed by the geometry and construction of the device and set by a fixed gate bias voltage applied at the gate above the channel of the transistor. One attempt to provide a variable gain of an FET amplifier uses two separate transistors in a cascode arrangement, such as described in a paper entitled “AlGaN/GaN-based Variable Gain Amplifiers for W-band Operation” by Diebold et al., Microwave Symposium Digest (IMS), 2013 IEEE MTT-S International DOI:10.1109/MWSYM.2013.6697340 publication year 2013 pages 1-4. However, the use of two separate transistors is relatively costly, lower yielding, and occupies a relatively large surface area.
SUMMARY
In accordance with the present disclosure, an HFET having a heterojunction semiconductor structure is provided. The heterojunction semiconductor structure includes: a pair of layers of different semiconductor materials forming a quantum well within the channel of the structure to support the 2DEG; source, drain and gate electrodes above the channel with the HFET having a predetermined transconductance; and a transconductance control electrode for varying an electric field within the structure under the channel to vary the shape of the quantum well and thereby the transconductance of the HFET in accordance with a variable control signal fed to the transconductance control electrode.
In one embodiment, an HFET is provided having: a source electrode in ohmic contact with a first portion of a surface of a heterojunction semiconductor structure having a pair of layers of different semiconductor materials forming a quantum well within the channel of the structure to support the 2DEG; a drain electrode in ohmic contact with a second portion of the surface of the structure; and a gate electrode in Schottky contact with a third portion of the surface of the structure disposed between the first portion and the second portion for controlling a flow of carriers between the source contact and the drain contact as such carriers pass through the channel. The source electrode, drain electrode and gate electrodes are disposed above the channel on a first one of the pair of layers. A fourth electrode is provided for varying an electric field within the structure to vary the shape of the quantum well in accordance with a variable control signal fed to the fourth electrode.
In one embodiment, an HFET is provided having: a source electrode in ohmic contact with a first portion of a surface of a heterojunction semiconductor structure having a pair of layers of different semiconductor materials forming a quantum well within the channel of the structure to support the 2DEG; a drain electrode in ohmic contact with a second portion of the surface of the structure; and a gate electrode in Schottky contact with a third portion of the surface of the structure disposed between the first portion and the second portion for controlling a flow of carriers between the source contact and the drain contact as such carriers pass through the channel. The source, drain and gate electrodes are disposed above the channel on a first one of the pair of layers. The HFET has a predetermined transconductance. A transconductance control electrode is provided for varying an electric field within the structure to vary the shape of the quantum well and thereby the transconductance of the FET in accordance with a variable control signal fed to the transconductance control electrode.
In one embodiment, the transconductance control electrode is disposed in the second one of the pair of layers for varying the electric field within the structure.
In one embodiment, the transconductance control electrode is disposed in a region of the second one of the pair of layers structure under the channel for varying the electric field within a region.
In one embodiment, an insulating layer is disposed between the transconductance control electrode and the region of the second one of the pair of layers structure under the channel.
In one embodiment, the transconductance control electrode is in ohmic contact with the region of the second one of the pair of layers structure under the channel.
In one embodiment, the transconductance control electrode is in Schottky contact with the region of the second one of the pair of layers structure under the channel.
In one embodiment, an HFET structure is provided, comprising: a heterojunction semiconductor structure having a pair of layers of different semiconductor materials forming a quantum well within the channel of the structure to support the 2DEG, such structure having a predetermined nominal transconductance; a source electrode in ohmic contact with a first portion of a surface of a semiconductor; a drain electrode in ohmic contact with a second portion of the surface of the semiconductor structure; a gate electrode in Schottky contact with a third portion of the surface of the structure, the third portion being disposed between the first portion and the second portion for controlling a flow of carriers between the source contact and the drain contact as such carriers pass through the channel. The source, drain and gate electrodes are disposed above the channel. A transconductance control electrode is for varying an electric field within the semiconductor under the channel to varying the shape of the quantum well and thereby the transconductance of the transistor in accordance with a variable control signal fed to the transconductance control electrode.
In one embodiment, a system is provided, comprising: an HFET, comprising: a heterojunction semiconductor structure having a pair of different semiconductor layers forming a quantum well within the channel of the structure to support the 2DEG, such structure having a predetermined nominal transconductance; a source electrode in ohmic contact with a first portion of a surface of a semiconductor; a drain electrode in ohmic contact with a second portion of the surface of the semiconductor structure; and a gate electrode in Schottky contact with a third portion of the surface of the structure, the third portion being disposed between the first portion and the second portion for controlling a flow of carriers between the source contact and the drain contact as such carriers pass through the channel. The source, drain and gate electrodes are disposed above the channel. A transconductance control electrode is provided for varying an electric field within the semiconductor under the channel to varying the shape of the quantum well and thereby the transconductance of the transistor in accordance with a variable control signal fed to the transconductance control electrode. The system includes a variable control signal generator for producing the variable control signal.
In one embodiment, the HFET structure and the variable control signal generator are disposed on a common semiconductor.
In one embodiment, the variable control signal generator senses temperature of the semiconductor and the control signal varies in accordance with variations in the sensed temperature.
With such arrangement, varying the shape of the quantum well and thereby the transconductance (g m ) of an HFET is provided by adding a fourth electrode (the transconductance control electrode in addition to the source, gate, drain) to provide an electric field under the channel to confine and modulate the 2DEG, thereby varying drain current flow and hence varying the transconductance of the device.
Thus, the transconductance g m of the HFET is varied by adding a 4th electrode (in addition to the source, gate, drain) to provide an electric field under the 2DEG channel to confine and restrict the 2DEG channel, thereby restricting drain current flow and hence varying the transconductance of the device (since transconductance is defined as change in drain current divided by the change in gate voltage).
The details of one or more embodiments of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic diagram of circuit having an HFET structure with a 2DEG in the channel having a predetermined nominal transconductance and a transconductance control electrode for varying an electric field under the channel to vary the shape of the quantum well and thereby the transconductance of the FET in accordance with a variable control signal fed to the transconductance control electrode in accordance with the disclosure;
FIG. 1A , is an analog circuit used as a temperature sensing compensation section of the circuit of FIG. 1 ;
FIG. 1B , is a digital circuit used as a temperature sensing compensation section of the circuit of FIG. 1 ;
FIG. 2 is a cross section of an HFET structure having a fourth electrode implemented as an metal-insulator-semiconductor contact used in FIG. 1 in accordance with the disclosure;
FIG. 3 is a cross section of an HFET structure having a fourth electrode implemented in ohmic or Schottky contact used in FIG. 1 in accordance with another embodiment of the disclosure.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
Referring now to FIG. 1 , a system 10 is shown formed on a single crystal substrate 12 , here for example, silicon carbide (SiC). The system 10 includes a HFET amplifier 14 having an HFET 16 . The HFET 16 has a gate 18 (G) fed to an RF input signal (V in ) through a coupling capacitor C in and to a V g bias voltage (−V g ) through an RF blocking inductor L 1 , as shown. The source electrode S of the HFET 16 is connected to ground, as shown. The drain D is connected to a (+V d ) bias through an RF blocking inductor, L 2 , as shown and provides the amplified output (V out ), after passing through a dc blocking capacitor C 2 , as shown.
The HFET 16 is provided with a transconductance control electrode 20 for varying the shape of the quantum well and thereby the transconductance of the HFET 16 in a manner to be described in more detail below. Suffice it to say here that the transconductance control electrode 20 is a control signal from a variable control signal generator, here, for example, a temperature sensing section 24 , formed on the substrate 12 , to be described. The temperature sensing section 24 generates the control signal in accordance with variations in the sensed temperature of the substrate 12 .
Here, for example, absent the temperature sensing section 24 , the HFET 16 has an unwanted oscillation when the substrate 12 is at room temperature; however, the oscillation reduces as the temperature of the substrate 12 increases because the gain of the HFET 16 reduces with increasing temperature as correspondingly the unwanted oscillation reduces. Here, the temperature sensing section 24 includes a temperature sensing device TS, here, for example, a diode D-(or mesa resistor or thermistor), as a part of either analog circuitry ( FIG. 1A ) or digital circuitry ( FIG. 1B ), to reduce the transconductance, and hence the gain, of the HFET 16 at room temperature to reduce or remove the unwanted oscillation and as the temperature of the substrate 12 increases above room temperature, the temperature sensing section 24 increases the transconductance, and hence the gain, of the HFET 16 in such a way so as not to reintroduce the unwanted oscillation.
Thus, in FIG. 1A , here the temperature sensing device TS, is here, for example, a diode D or mesa resistor or thermistor, formed on the substrate 12 , serially connected between a predetermined negative voltage source −VREF and ground through a pair of resisters R 1 and R 2 , as shown. The output of the temperature sensing device TS is fed to the fourth electrode 20 , as shown. Thus, a voltage divider network is formed having in addition to the serially connected resistors R 1 and R 2 the temperature sensing device TS. The voltage at the junction between temperature sensing device TS and the resistor R 1 is fed to the fourth electrode 20 . When the substrate 12 is at room temperature the values of R 1 , R 2 and −VREF of the temperature sensing section 24 are selected to produce a voltage at the fourth electrode 20 that results in removal or reduction of the unwanted oscillation and, as the temperature of the substrate 12 increases above room temperature, the temperature sensing section 24 adjust the voltage at the fourth electrode 20 so that it becomes more positive to thereby increase the transconductance of the HFET 24 without reintroducing the unwanted oscillation.
For example, a measurement is made of the voltage drop V x across of the temperature sensor TS, for example diode D (or mesa resistor or thermistor), at room temperature with a predetermined current passing through it, for example, 3 mA. Assume V x =2 Volt is measured with 3 mA current passing through it at room temperature. Next, the value of R 1 is set to a convenient value, for example, R 1 =500 ohms. Next, the −V REF is set to a convenient negative voltage, for example, −5 Volts. With the voltage at the fourth electrode 20 at 0 Volts, the voltage at the gate electrode G, V G , is selected for the desired drain current Id and/or the desired peak transconductance g m ; for example V G =−2V. The value of the resistance of R 2 is adjusted to yield a voltage applied to the fourth electrode 20 such that the oscillation at room temperature stops. For example, R 2 =500 ohms, and the voltage of the fourth electrode 20 is =−1.5 V
In FIG. 1B the temperature sensing section 24 ′ has the temperature sensing device TS, again, for example, the diode D (or mesa resistor or thermistor) and voltage at the junction between the anode of the temperature sensing device TS and the resistor R 1 is first converted into a corresponding digital signal by an analog to digital converter (A/D). The corresponding digital signal is fed to a microprocessor 40 , as shown. As a result of an a priori calibration process which produces a relationship between the voltage produced at the output of the diode D (or thermistor or mesa diode) (and hence a measure of substrate 12 temperature) and proper voltage at the fourth electrode 20 (and hence the transconductance of the HFET 24 ) to reduce or remove unwanted oscillations at room temperature while not reintroducing the unwanted oscillation above room temperature, the produced relationship is stored as data in a table of the microprocessor 40 . The microprocessor is programmed to use the stored data to produce a proper voltage for the fourth electrode 20 at room temperature and above room temperature in accordance with the voltage produced by the diode D (or thermistor or mesa diode).
Referring now to FIG. 2 , the HFET 16 is shown to include: a heterojunction semiconductor structure 30 having the single crystal substrate 12 , here for example, silicon carbide (SiC), a III-V buffer or nucleation layer 34 , here for example, Aluminum Nitride (AlN) on the substrate 12 , a gallium nitride (GaN) layer 36 on the nucleation layer 34 ; and an Aluminum Gallium Nitride (AlGaN) layer 38 formed on the gallium nitride (GaN) layer 36 in any conventional manner to form a heterojunction between the gallium nitride (GaN) layer 36 and the Aluminum Gallium Nitride (AlGaN) layer 38 to thereby produce a quantum well to support the 2DEG 40 within the structure 30 . Once fabricated, the HFET has a predetermined nominal transconductance.
The HFET 16 has: a source electrode, S, in ohmic contact with a first portion of a surface of a source contact region 42 of the Aluminum Gallium Nitride (AlGaN) layer 38 ; a drain electrode, in ohmic contact with a drain contact region 44 of the Aluminum Gallium Nitride (AlGaN) layer 38 ; and a gate electrode, G, in Schottky contact with a Schottky contact region 46 of the Aluminum Gallium Nitride (AlGaN) layer 38 , the gate contact, 18 , being disposed between the source S and drain D for controlling the flow of carriers between the source S and the drain D as such carriers pass through the 2DEG 40 . It is noted that the source electrode, S, the drain electrode D and gate electrode 18 (G) are in contact with the AlGaN layer 38 above the 2DEG 40 .
The structure 30 includes a fourth electrode 20 , here a transconductance control electrode. More specifically, a via 54 is formed through the back side 52 of the substrate 12 using any conventional technique, such as photolithographic etching or laser drilling. The via terminates in a bottom portion 56 disposed in the GaN layer 36 , under the portion of the 2DEG 40 in a region between, and under, the Schottky region 46 and drain contact region 44 as shown. After forming the via 54 , the sidewalls of the via 54 , including the bottom portion 56 of the via 54 are coated with a thin dielectric layer 58 , here, for example, silicon nitride (SiN) having a thickness in the range of 5 to 100 nm.
Next, a conductive layer 60 , here a metal, for example gold, is deposited over the bottom surface 52 of the substrate 12 and is then selectively removed from the bottom 52 of the substrate 12 using any conventional photolithographic etching technique to form the fourth electrode 20 , as shown. It is noted that the bottom of the fourth electrode 20 is separated from the GaN layer 36 , as well as from the AlN layer 34 by underlying portions of the dielectric layer 58 . With a variable voltage applied to the fourth electrode 20 , a varying electric field will be produced within the GaN under the 2DEG 40 varying the shape of the quantum well and thereby the transconductance of the HFET 16 in accordance with a variable control signal fed to the transconductance control electrode, as for example, from the temperature sensing section 24 of FIG. 1 .
Referring now to FIG. 3 , another embodiment is shown for the HFET 16 ′. Here, after coating the sidewalls of the via 54 , including the bottom portion 56 of the via 54 with the dielectric layer 58 , here for example. SiN, the portion of the dielectric layer 58 on the bottom portion 56 is removed to expose an underlying portion of the GaN layer 36 . Next, a conductive layer 60 ′ is deposited over the bottom surface 52 of the substrate 12 and is then selectively removed from selected portions of the bottom 52 of the substrate 12 to form the fourth electrode 20 ′, as shown. It is noted that here the fourth electrode 20 ′ may be formed either in ohmic or Schottky contact with the portion 37 of the GaN layer 36 at the bottom portion 56 of the via 54 .
A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. For example, other control circuits may be used instead of the temperature sensing compensation section, such as a section that detects output power and produces a control signal for the fourth electrode to set the gain necessary for the desired output power level. Accordingly, other embodiments are within the scope of the following claims. | A heterojunction semiconductor field effect transistor HFET having a pair of layers of different semiconductor materials forming a quantum well within the structure to support the 2DEG. Source, drain and gate electrodes are disposed above the channel. The HFET has a predetermined transconductance. A transconductance control electrode varies an electric field within the structure under the channel to vary the shape of the quantum well and thereby the transconductance of the FET in accordance with a variable control signal fed to the transconductance control electrode. | 7 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to heating devices and, more particularly to novel, improved devices for heating or warming the contents of bottles and other containers.
The principles of the present invention can be employed to particular advantage in warming shampoos, conditioners, and other hair care products; and the principles of the present invention will accordingly be developed primarily with reference to such applications of the invention. It is to be understood, however, that this is being done for the sake of brevity and clarity and is not intended to limit the scope of the invention as defined in the appended claims.
BACKGROUND OF THE INVENTION
It is well known that the application of unheated, room temperature shampoos, rinses, conditioners, shaving cream, and the like to a person's scalp or face can produce a very uncomfortable and unpleasant feeling. This gives rise to frequent complaints in beauty salons, barbershops, and other establishments where the customer's comfort and consequent satisfaction is of paramount importance.
Unpleasant sensations can be avoided and comfort assured by warming the shampoo or other formulation in its container before applying it to the customer's scalp or face.
Also, there are preparations which tend to congeal, crystallize or precipitate, agglomerate, or become viscous at room temperature. This makes it difficult to pour or otherwise expel the contents of the container. Again, this is a problem which can be readily solved by employing a heater utilizing the principles of the present invention to warm the preparation at the time and point of use.
A number of patents disclose heaters for bottles and similar containers, and some of them even disclose heaters for hair care products. The patents of which I am aware are U.S. Pat No. 2,090,666 issued Aug. 24, 1937 to Copeland for HEATER FOR SCALP SOLUTIONS; U.S. Pat. No. 2,292,992 issued Aug. 11, 1942 to Crouch for HEATING DEVICE; U.S. Pat. No. 2,413,176 issued Dec. 24, 1946 to Deaton for MILK BOTTLE HEATER; U.S. Pat. No. 2,713,112 issued Jul. 12, 1955 to Mills et al. for BOTTLE OR CONTAINER WARMER; U.S. Pat. No. 3,005,904 issued Oct. 24, 1961 to Thompson for COMBINATION SALT DRIER AND NIGHT LIGHT; U.S. Pat. No. 3,138,699 issued Jun. 23 1964 to Taylor for HEATING APPLICANCES; U.S. No. 3,152,245 issued Oct. 6, 1964 to Litman for INFRARED NURSING BOTTLE HEATER; U.S. Pat. No. 3,456,679 issued Jul. 22, 1969 to Woods for PACKAGED FOOD DISPLAY AND HEATING DEVICE; U.S. Pat. No. 4,107,513 issued Aug. 5, 1978 to Ashford for SHAMPOO CONDITIONER WARMER; U.S. Pat. No. 4,119,834 issued Oct. 10, 1978 to Losch for ELECTRIC RADIANT HEAT FOOD WARMER AND ORGANIZER; U.S. Pat. No. 4,215,843 issued Aug. 5, 1980 to Gay et al. for TOY MOLDING APPARATUS AND MATERIAL FOR USE THEREWITH; and U.S. Pat. No. 4,273,992 issued Jun. 16, 1981 to Thomas for ELECTRIC HEATING APPARATUS FOR HEAT-TREATING PHARMACEUTICALS.
Heating devices as disclosed in the foregoing patents tend to have a number of drawbacks and disadvantages. One is that they are unsafe to use, particularly in beauty salon and other operations where the user may have wet hands and therefore be particularly susceptible to injury if subjected to electrical shock. Also, the prior art heating devices tend to be very difficult to clean to the level required by local regulations applicable to beauty salons and comparable establishments. Efficient distribution of heat to the product being warmed and lack of easy access to the heating element are still other disadvantages of these prior art heating devices.
SUMMARY OF THE INVENTION
There have now been invented, and disclosed herein, certain new and novel devices for warming shampoo and for other applications which do not have the foregoing or other disadvantages of kindred heating devices. These devices are, efficient, safe to use, and easy to clean. The heating element is well protected, and it is easy accessible. At the same time, the novel heating devices disclosed herein are simple and correspondingly inexpensive to manufacture.
Generally speaking, the novel heating devices disclosed herein include a housing with a base. A heating element such as a conventional incandescent bulb is mounted on the base, typically in an upright orientation and midway between the ends of the casing.
A removable end wall and circular openings in the top wall of the casing give the operator easy access to the interior of the casing and to heating element when it becomes necessary to replace it. The top wall openings also serve as installation ports for removable, elongated, vertically oriented, cylindrical inserts or container holders with a closed lower end and an open upper end. The inserts rest on the bottom or lower wall of the heating device casing and extend upwardly to and into loose fitting engagement with the upper wall of the casing.
The inserts position the containers of shampoo or other product in the casing of the heating device and are so constructed as to promote the transfer of heat from the heating element to the product. With the inserts removed from the casing of the heating device, both they and the interior of the casing can be easily cleaned. The inserts also facilitate the task of keeping the casing interior clean by capturing any product which might run or drip down the sides of the containers.
From the foregoing, it will be apparent to the reader that one primary and important object of the present invention resides in the provision of novel, improved devices for warming shampoos, conditioners, and other packaged products.
A related and also important objects of the invention resides in the provisions of such heating devices which have the attributes and advantages identified above.
Still other important features, advantages, and objects of the invention will be apparent to the reader from the foregoing and the appended claims and as the ensuing detailed description and discussion proceeds in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a heating device embodying the principles of the present invention and a bottle containing product which is to be warmed by the heating device;
FIG. 2 is a longitudinal section through the heating device, show in this figure in a partially, disassembled configuration with the bottles and inserts removed.
FIG. 3 is a section through a removable insert which is a component of the heating device;
FIG. 4 is a bottom view of the heating device; and
FIG. 5 is a schematic of an electric heater employed in the heating device.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, FIG. 1 depicts a heating device 20 for warming the contents of a plastic bottle or container 24 and the contents of a second, similar container 28. Heating device 20 is constructed in accord with, and embodies the principles of the present invention. In a typical application, bottle 24 will contain a shampoo; and bottle 28 will contain a conditioner or rinse.
The major components of heating device 20 include a casing 30 which houses a radiant heater 32 (see FIG. 2) and two removable, container-receiving inserts 34 and 36 which also serve as heat sinks and even out the transfer of thermal energy to the products being heated. The casing 30 of heating device 20 has a parallelpipedal configuration defined by side walls 38 and 40, end walls 42 and 44, a top wall 46, and a bottom wall or base 48.
End wall 44 can be detached to give easy access to the interior of casing 30. It is secured in place as by the illustrated machine screws 50. These extend through the end wall and are threaded into two upper bosses 52 (only one of which is shown, see FIG. 2) and a lower boss 54. Bosses 52 extend inwardly from the side walls 38 and 40 of the casing adjacent op wall 46, and boss 54 extends upwardly from base 48 at a locus intermediate the casing side walls.
Internally threaded apertures 56 in the three bosses (only one of which is shown) accept screws 50 and retain them in place.
Openings 58 and 60 are formed through the top wall 46 of heating device casing 30. They are centered on the longitudinal, vertical centerplane of casing 30 and are located at equal distances from the end walls 42 and 44 of the casing. Openings or apertures 58 and 60 are configured to complement the cross sectional configuration of inserts 34 and 36. They are so dimensioned as to have a loose fit with the top wall 46 of the casing when the inserts are in place (see FIGS. 1 and 2).
Heating device casing 30 will typically be fabricated from a heat and impact resistent polymer such as Monsanto Plastic's 252, 452, or 752 Lustran ABS extrusion resins.
Referring now specifically to FIG. 2, the radiant heater 32 of device 20 includes a conventional incandescent bulb 62 and an electrical socket 64. Socket 64 is centered between inserts 34 and 36 and also between casing side walls 38 and 40. It extends upwardly from base 48 to which it is attached as by the illustrated screws 66.
Socket 64 is connected to an external, typically 110V AC power source 68 (see FIG. 5) as by the illustrated line cord 70. The line cord has two leads or conductors 72 and 74. A line cord switch S76 allows an operator to turn the incandescent bulb 62 of radiant heater 32 on and off.
As is shown in FIGS. 1-3, line cord 70 is trained through an opening 78 in heating device casing base 48. Downwardly opening recesses 80 and 82 in casing side walls 38 and 40 and comparable recesses 83 and 84 in casing end walls 42 and 44 (see FIGS. 1 and 3) allow line cord 70 to be routed from beneath the heating device to a wall or floor socket, etc. (not shown) toward the front, the back, or either end of the casing. This is a decided convenience.
Bulb 62 is intended to warm the product in a container 24 or 26 to a temperature which is comfortable, not hot--typically a temperature in the 100°-107° F. range. A 25 watt bulb is typically the size best suited to maintain the product temperature in the preferred range.
Temperatures in the preferred range also have the advantage that they are not apt to cause unwanted changes in the chemical composition of the product. If the temperature to which a product can be safely heated is in doubt, this information should of course be solicited from the manufacturer or supplier.
The two container-receiving inserts 34 and 36 which position containers 24 and 26 in heating device casing 30 and in the wanted, equidistantly spaced relationship to radiant heater 32 are identical. Therefore, only insert 34 will be described in detail.
That insert, best shown in FIGS. 1 and 3, has a vertically extending side wall 86 and an integral bottom wall 88. These walls cooperate to define an open compartment 90 for container 24. While the cross sectional configurations of the insert and container are complementary, the internal diameter of the insert side wall 86 is larger than the external diameter of bottle 24. This allows the bottle to be easily installed in and removed from the insert.
Installed, inserts 34 and 36 are seated on the base 48 of heating device casing 30. They extend from that base up into the openings 58 and 60 through casing top wall 46 with the open, upper end of the insert (see, for example, that end of insert 30 identified by reference character 92 in FIG. 3) slightly below the exposed surface of the upper casing wall and out of an operator's way. At the same time, the loose fit between the insert and casing top wall 46 keeps the insert properly located in casing 30.
The inserts 34 and 36 and casing 30 are preferably so dimensioned in the vertical direction that the bottles 24 and 28 holding the products to be warmed will extend approximately the illustrated finger's width above the top wall of the casing. This promotes the heating of container contents 22 and 26 by placing the contents of the bottle almost entirely within casing 30, even if the bottle is full. At the same time, exposure of the container upper end makes it easy for the operator to install containers 24 and 28 in inserts 34 and 36 and to remove them from the inserts.
As is shown in FIGS. 1 and 3, inserts 34 and 36 are free of attachment to casing 30, and they can be removed from the casing with exceptional ease; i.e., by merely lifting them out of the casing through the associated top wall openings 58 and 60. Installation of the inserts in heating device casing 30 is equally simple. This is accomplished by lowering the inserts through openings 58 and 60 until they reach the base 48 of casing 30.
In a typical application of the present invention, the casing top wall openings 58 and 60 are 30 large enough in diameter for an operator's hand to fit through them. This makes it easy to replace incandescent bulb 60 and to wipe clean the interior of casing 30, once inserts 34 and 36 have been removed in the manner just described. Alternative, and perhaps preferably, the bulb can be changed by removing casing end wall 46.
Inserts 34 and 36 are preferably fabricated of a relatively heat resistant polymer which is essentially transparent to the infrared radiation emitted by incandescent bulb 62. Among the many polymers which can be employed are the thermoplastic Rohm & Haas Plexiglas® poly(methyl methacrylates).
As is shown, vertical slots 94, 96, and 98 extend from toward the bottom wall 88 of insert 34 (and insert 36) toward the open, upper end of the insert so that air can circulate freely through the insert and between the insert and the container installed in it. This promotes the heating of the container's contents by natural convection of air heated by incandescent bulb 62 as well as by the radiant energy emitted from that infrared radiation source. Also, slots 94, 96, and 98 eliminate dead air spaces, ensuring that the product being warmed is uniformly heated.
As is shown in FIGS. 1 and 3, the lower ends 100 of slots 94, 96, and 98 are kept at a level well above the bottom wall 88 of the insert in which they are formed. This results in the side wall 86 and bottom wall 88 of the insert cooperating to form a cavity 102 in the lower end of bottle-receiving compartment 90..
Product leaked from a bottle 24 or 28 as through the valve 104 in its closure 106 and dripping down the container can collect in cavity 102. So can water reaching the bottle from an operator's hand--for example, from the hand of one giving a customer a shampoo in a beauty salon. This is an important practical feature of the present invention as it keeps the product, water, etc. from reaching and soiling the interior of heating device casing 30. Any foreign material which does collect in the bottom of the insert can be easily reached by removing end wall 46.
Also, by keeping water and other conductive fluids from running along the base 48 of casing 30, the inserts significantly reduce the exposure of persons using heating device 20 to electrical shock.
An integral, ringlike seat is formed on the top of each insert's bottom wall 88. This seat of insert 34 is identified by reference character 108 in FIGS. 1 and 3. The seat just described positions the bottom 110 of container 24 (or 28) above the bottom wall 88 of the associated insert 34 or 36. This keeps a product which may have escaped from a container or been left on the bottle by an operator's hand away from the bottom of that container. This avoids further soiling of the container by the product or liquid.
The integral seats 108 also allow heated air to circulate across the bottom 110 of container 24 and the bottom of container 28. That further contributes to the efficiency with which heating device 20 operates.
The operation of heating device 20 is believed to be apparent from the foregoing detailed description of that device. Nevertheless, for the sake of completeness, a summary of the modus operandi follows.
Unless done previously, the initial step is to install removable inserts 34 and 36 in heating device casing 30 in the manner discussed above. Next, the operator inserts the bottle or bottles containing the product to be heated in the insert(s) by lowering each container through a top wall opening 58 or 60 until it reaches the integral seat 108 on the insert bottom wall 88. Next, line cord switch S76 is manually closed, turning on heater 32. Thereafter, radiant energy emitted from the heater's incandescent bulb 62 and air warmed by the bulb and circulated into heat transfer relationship with the container by natural convection heat the container's contents. Once these are warm, which will typically take on the order of one hour, the operator removes the container from heating device 30 through the appropriate top wall opening 58 or 60 and utilizes the warmed product for the intended purpose. Of course, all or part of the bottles and their contents may be warmed before they are placed in the heating device 30. In that case, they are instantly ready for use.
The invention may be embodied in other forms without departing from the spirit or essential characteristics of the invention. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | A heating device for warming the contents of bottles and other containers. The device has a casing in which a radiant heater is mounted and a container-receiving cylindrical insert in the casing in heat transfer relationship to the radiant heater. The insert is removable from the casing through an opening in the casing top to facilitate cleaning. The insert has an imperforate lower portion capable of intercepting and trapping any product which may drip or run down the container side and openings in an upper portion allowing air to circulate into convective heat transfer with the container. The closed base of the insert has a raised seat which spaces the bottom of the container above the insert base to allow air to circulate across the bottom of the insert and to prevent any product collected in the insert from soiling the container. | 7 |
BACKGROUND
The subject matter presented herein relates to apparatus and methods for displaying information. More particularly, it relates to those apparatus and methods for power management in displays of electronic devices generally and in electronic books or e-books, specifically.
Traditionally, e-books have differed from computers in that e-books run in low power mode due to their black and white static screens run by low power microcontrollers. Their screen technology only uses power on change, and books are static so they do not need to change often (for example, once every 30 seconds or so is adequate).
However, the present inventors have recognized herein that as the e-book product category matures in function, higher end (and higher power) features will be added that support markups, multimedia and other direct user input. These features will require a higher featured operating system and graphics controllers and higher power LCD screens with high refresh rates than previously needed for e-books. Problems will arise when e-books spend too much time in the higher power mode. Usable reading time after charging of the internal battery may be drastically reduced.
SUMMARY
Thus, what is described herein is an electronic device comprising a power source; a display having a high power mode and a low power mode, the display being powered by the power source; and a power controller which switches the device to a low power mode in response to no changes being indicated for one or more first selected regions of the display for at least a predetermined time, wherein the area of said one or more first selected regions is less than the area of the display. The power controller can switch the display from the low power mode to the high power mode in response to changes to the display being indicated in display portions other than the one or more first selected regions.
In the low power mode, the display can be static, and is not refreshed. The predetermined time can be between fractions of a second and sixty seconds.
The electronic device can have a region selection mode, wherein one or more second regions of the display are selected so that changes in the second regions do not change the mode of the display from a low power mode to a high power mode. The one or more of the second regions that are selected can be a region for the display of a specific icon. The icon can be selected from the group consisting of a clock icon and a status icon. The electronic can have a monitoring mode wherein changes in the second selected regions of the display do not switch the display from a low power mode to a high power mode. Change in regions of the display other than the second selected regions of the display can switch the display from a low power mode to a high power mode.
The electronic device can be configured as an electronic book.
Also described herein is a method comprising providing an electronic device including a display having a high power mode and a low power mode; wherein a switching of the device to a low power mode occurs when no changes to one or more first selected regions of the display are indicated for at least a predetermined time wherein the area of said one or more first selected regions is less than the area of the display.
The switching of the display from the low power mode to the high power mode can occur when changes of the display are indicated in display portions other than the one or more first selected regions. In the low power mode, the display can be static, and is not refreshed. The predetermined time can be, for example, between a fraction of a second and sixty seconds. The method can further comprise placing the device in a region selection mode wherein second regions of the display are selected so that changes in the second regions do not change the mode of the display from a low power mode to a high power mode.
A region of the second regions that are selected can be a region for the display of a specific icon. The icon can be selected from the group of a clock icon and a status icon.
The method can further comprise placing the device in a monitoring mode wherein changes in the second selected regions of the display do not switch the display from a low power mode to a high power mode. Change in regions of the display other than the second selected regions of the display can switch the display from a low power mode to a high power mode.
Also described herein is an electronic device comprising a power source; a display memory; a display for displaying contents of the display memory, the display defaulting to a low power mode during ordinary use, and having a high power mode, the display being powered by the power source; and a power controller which switches the device to a high power mode in response to changes being indicated in the display memory.
Also disclosed is a computer storage medium having computer readable code stored thereon for execution by an electronic device including a display having a high power mode and a low power mode, so as to switch the display to a low power mode when no changes to one or more selected regions of the display are indicated for at least a predetermined time.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and other features of the present embodiments are explained in the following description, taken in connection with the accompanying drawings, wherein:
FIG. 1 depicts a non-limiting example of e-book according to an embodiment.
FIG. 2 is a flow chart of the operation of the e-book of FIG. 1 .
FIG. 3 is an additional flow chart of the operation of the e-book of FIG. 1 .
DETAILED DESCRIPTION
As an overview, it is assumed that an e-book device can detect when it needs to move from the low power “e-book mode” into “full OS” (full operating system) mode. Full OS mode is used to enable higher end graphics features such as pen input and can include other graphics operations such as video, system status notifications, etc. The graphics subsystem can quickly notify the e-book power management engine that it is complete with the operations by monitoring the contents of the frame buffer that is being displayed to the e-book at any given time. When no changes have occurred within a predetermined time, the power management control is signaled to go back into low power e-book mode. In accordance with a further aspect, specific areas within the screen boundaries of the “full OS” mode that are not critical regions are identified. These regions can be just status icons, or the clock or other low priority pieces of information. Changes are allowed in the frame buffer for these areas but do not drive the device to “full OS” mode.
Referring to FIG. 1 , there is shown a block diagram of a non-limiting example of e-book 10 . Although a single embodiment is shown in the drawings, it should be understood that there can be many alternate forms and embodiments. In addition, any suitable size, shape or type of elements or materials could be used.
E-book 10 is operated under the control of a processor 12 connected to a system memory 14 , which may store therein an operating system and appropriate software for permitting operation of the various other components of e-book 10 as described below. Processor 12 may also be connected to a wireless subsystem 16 , having an antenna element 18 for permitting e-book 10 to interface with a network, such as the internet or a 3G wireless network so that data, including books to be stored and eventually read by using e-book 10 , may be received by e-book 10 .
Processor 12 may also be connected to a touchscreen controller 20 so that appropriate user inputs may be provided to facilitate the operation of e-book 10 . Processor 12 may also be connected to an input/output block 22 including a USB interface 24 , an SD card slot 26 , and an audio output 28 for, for example, a headphone 30 . A display controller 32 is connected to processor 12 . Display controller 32 is connected to a display memory 34 , which provides input for what is displayed on an e-book display 36 . Display memory 34 includes a video frame buffer 35 .
E-book 10 is powered by power management and power controller block 38 , which receives power from a battery and controller block 40 . Generally, a power adapter (not shown), of a type well know in the art, plugs into a 120 or 240 volt power outlet in a home or office, and supplies suitable direct current input to a jack 42 to charge a battery associated with block 40 .
Referring to the flow chart of FIG. 2 , at block 50 , power management and power controller block 38 , is in a full power state, wherein display 36 may be refreshed at a high rate, such as 60 times per second (60 Hz). At this time, display events may be occurring very rapidly. At block 52 , monitoring of display memory 34 is conducted for a programmable period of time. By way of example and not by way of limitation the predetermined time can be between a fraction of a second and sixty seconds. At 54 , if there have been changes to the content of the video frame buffer 35 of display memory 34 , the programmable period of time specified by block 52 is restarted. If at 54 , there have been no changes to the content of the video frame buffer 35 of display memory 34 , then, at 56 , power management and power controller block 38 switches e-book 10 to a low power mode where the refresh rate for e-book display 36 is dropped to 0 Hz (in other words, the display is static), taking advantage of the very low power required when the e-book display is in this mode. It will be understood that most e-books use displays 36 of this kind so that battery life, when simply reading a book, is enhanced. Thus, if no changes are indicated (defined as required changes, detected changes, made changes, queued changes, or a determination that changes must be made) for the predetermined period of time, the transition is made.
At 58 , events that require e-book display 36 to be updated are monitored. These events can be those associated with a change in the video frame buffer that requires a screen update, as described below, or other events such as, for example, a low battery alarm, the operation of the touchscreen, or a signal indicating that a file for a new book is being downloaded or has completed downloading. At 60 , a determination is made as to whether one of those events has occurred. If not, monitoring continues at 58 . If one of those events has occurred, such as the need for a change in contents for display, then at 62 , e-book display 36 is switched to the high power mode wherein it is refreshed at 60 Hz. For example, this could be due to the video frame buffer of display memory 34 being updated in other than certain limited ways, as described below.
Referring to FIG. 3 , there is illustrated the manner in which a selection is made as to which changes in the video frame buffer 35 of display memory 34 are significant in terms of changing the display mode of e-book display 36 from a low power mode to a high power mode. At block 70 , a selection is made as to a portion of the display 36 (selected by moving a cursor in a closed path or by selecting a particular icon) which portion can undergo changes without switching display 36 to the high power display mode. These areas might be just status icons, or the clock or other areas of the display that show low priority pieces of information.
At 72 , a determination is made as to the memory ranges in the video frame buffer 35 of display memory 34 that are associated with the region or icon selected at 70 . At 74 , a decision is made as to whether all regions or icons of the display 36 have been selected, that are of interest for not changing the mode of display 36 when the information to be displayed is changed. If additional regions or icons are to be changed, then branching to block 70 occurs. If no additional regions or icons are to be selected, then they system is caused to transition from a region or icon selection mode to a monitoring mode at 76 , wherein the video frame buffer is monitored for any changes. It should be noted that icons and regions are not synonymous; for example, a region may contain one or more icons or gadgets therein, or individual icons or gadgets may be selected. The terms icons and regions are to be given their plan and ordinary meanings.
If there are no changes detected at 78 , then monitoring continues at 76 . If there are changes at 78 , then at 80 , a determination is made as to whether the changes occurred in the memory ranges of video frame buffer 35 of display memory 34 associated with the regions or icons of display 36 which were selected in the selection mode of blocks 70 , 72 and 74 . If the changes in video frame buffer 35 of display memory 34 were in the selected memory range(s), then branching to block 76 occurs, and there is no change in the display mode from the low power mode to the high power mode of display 36 . If the changes in video frame buffer 35 of display memory 34 were not in the selected memory range(s), then branching to block 82 occurs. A report is sent to block 58 of FIG. 2 indicating that a significant change in the video frame buffer 35 of display memory 34 has occurred, thus changing the display mode from the low power mode to the high power mode of display 36 .
In view of the above, it will be understood that changes are allowed in the frame buffer only for certain regions of the display, or certain icons thereon that do not drive the e-book display into a “full OS” mode. However, if a user of the e-book wishes to be certain that the latest information is displayed by, for example, icons that have been selected so that changes do not update the display, (a specific example could be the time on a clock icon) it is only necessary for the user to perform an operation that changes a portion of the display that has not been so selected, such as, for example, but not by way of limitation, moving the screen cursor to a region or an icon that has not been selected. This will cause a change in video frame buffer 35 of display memory 34 which will be in a memory location that is not inhibited from causing a change in the power state of display 36 , and the of display mode of display 36 will move to a high frequency of update, thus providing the latest information (such as the current time on a clock icon).
The operation shown in FIG. 2 and FIG. 3 can be implemented in hardware or software. In one embodiment, the contents of the video frame buffer can be monitored by hardware configured accordingly. When implemented in hardware, the monitoring and other functions shown in FIG. 2 and FIG. 3 can occur very quickly without any software dependency, minimizing the latency period required to go into low power mode, and thus enhancing battery life. However, the technology described herein can also be implemented in software. In that regard, the required program instructions can be stored on a computer storage medium that can be connected to the e-book via an internal bus. This bus can connect the processor to an on board ROM or other storage medium from where the instructions can be stored and executed.
There are at least two embodiments wherein the device can be placed in a low power mode. In one embodiment, power management and power controller 38 places at least the graphics subsystem into the low power mode from a high power mode. In another embodiment, power management and power controller 38 places all subsystems which are not required to come out of low power mode into a low power mode to further reduce power consumption. By way of a non-limiting example, power management and power controller 38 can place into a low power mode processor 12 , system memory 14 , wireless subsystem 16 , and input/output block 22 in addition to the graphics subsystem which comprises at least display controller 32 , display memory 34 , video frame buffer 35 , and eBook display 36 .
It should be understood that the foregoing description is only illustrative. Various alternatives and modifications can be devised by those skilled in the art. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. | An electronic device, such as an e-book, for displaying information includes a power source; a display having a high power mode and a low power mode, said display being powered by said power source; and a power control arrangement for switching the display to a low power mode when no changes to selected regions of the display are required for at least a predetermined time. The power control arrangement switches said display from said low power mode to said high power mode when changes of said display are required in display portions other than said selected portions. A method for operating the electronic device. A computer readable medium having computer readable instructions thereon for implementing the method. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to an axle suspension for a vehicle axle guided by a trailing arm, with a support which can be fixed on each vehicle side underneath a vehicle chassis, in which a trailing arm is fastened for rotary movement, which is supported by its other end via an air spring opposite the vehicle chassis, with a vehicle axle which crosses the trailing arm and fitted at its ends with the vehicle wheels, and with at least one axle lift with a force element, a pressure transmission means movable by actuating the force element against the trailing arm, as well as a console bracket which is provided with a supporting means for the force element and the pressure reaction forces acting on same, and which furthermore for fixing on the support is provided with a console bracket part on which a plug-in or hook connection is formed for engagement in the support. The invention also relates to an axle lift for a vehicle axle with a force element, a pressure transmission means which is movable by actuation of the force element against an axle link of the vehicle axle, as well as a console bracket which is provided with a supporting means for the force element and the pressure reaction forces acting on same, and which furthermore for fastening on a support which consists of two side walls and an end wall pointing in the drive direction and connecting the side walls together, is provided with a console bracket part on which a plug-in or hook connection is formed for engaging in the support.
In the axle suspension of an air-suspended vehicle axle according to EP 0 961 726 B1 a diaphragm cylinder operated by compressed air serves as the force element for raising the vehicle axle. This cylinder is supported on a console bracket which is mounted underneath the support of the vehicle axle. The support holds in its two side walls a bearing bolt which defines the pivotal axis for each relevant axle link of the vehicle axle. In order to divert the considerable forces used when lifting the axle to the support the console bracket engages by the arms formed thereon over the side walls of the support wherein the arms are supported inter alia against the bearing bolt. A part of the forces which occur during lifting of the vehicle axle is therefore transferred to this bolt and thus to parts of the axle suspension which are involved in the dynamic driving process.
From DE 699 17 105 T2 an axle suspension with an axle lift is known in which the force element which is designed here as an air spring is supported on a console bracket which is made up as a whole from three parts. A first console part on which the force element is directly supported is provided with a plug-in connection for engaging in the region of the end wall of the support. Constituent parts of the console brackets are furthermore suspension plates on either side of the support wherein the lower ends of the plates are each screwed to the first console bracket part and whose upper ends are suspended from the screw bolt. Also with this embodiment the axle lift is therefore supported inter alia on that bearing bolt which supports the axle link so that at least a part of the forces acting during lifting of the vehicle axle is also transferred to this bolt and thus to parts of the axle suspension which are involved in the dynamic driving process.
An axle suspension and axle lift without these drawbacks is known from DE 10 2006 044 598 A1. In order to obtain a console bracket which is adjustable over a wide region this bracket is designed in two parts wherein a first bracket part is a block-shaped pressure member which is screwed between two arms of the second console bracket part and is supported from below against the rod support. A second console bracket part is connectable via corresponding rows of holes in different positions to both the first bracket part and also the support. During assembly of the axle lift, in order to avoid faulty installation, it is necessary to use the correct pairs of holes, i.e. those which match the relevant chassis geometry. After horizontally inserting the first console bracket part the rows of holes of the second console bracket part have to be brought to overlap the two holes of the side walls of the support. It can thereby happen that the wrong hole is chosen for the connection, and the first console bracket part then no longer engages adequately with the end wall of the support. There is the danger that this connection subsequently becomes loose through the loads arising during driving operation. As a result the axle lift would pivot out of the way and lose its function since the lifting force no longer engages on the site provided for that purpose, and in the worst case scenario the second console bracket part could even shear off.
The axle lift according to DE 10 2006 044 598 A1 operates with a favorable diversion of the pressure reaction forces but up to the final fitting of the axle lift several assembly steps are required, inter alia for correctly adjusting and positioning the two console bracket parts.
The aim of the invention is therefore to be able to mount the console bracket of the axle lift with few manual steps in a basic setting on the support.
SUMMARY OF THE INVENTION
This is achieved through an axle suspension wherein the console bracket part can be attached in only one single position relative to the support. This is further achieved through an axle lift wherein the console bracket part is provided spaced from its plug-in or hook connection with at least one further connecting means which is formed for engaging in the support.
With few manual steps the console bracket can be fastened on the support in a basic position in which the axle lifting forces are safely transferred. The connection takes place in two regions at a distance from one another. The first connecting means is a plug-in or hook connection which is formed on the console bracket part. The other connecting means, at a distance from this, can consist for example of a rod mounted transversely in the console bracket part. This can be passed through openings located in the side walls of the support in order to fasten on the support.
When fixing the console bracket part first the plug-in or hook connection is brought into engagement with the support for which it is only necessary to move the console bracket part accordingly up to engagement. Further manual steps, thus for example screwing, fixing a securing ring etc. are not required in respect of this first connection.
A load-bearing mounting of the console bracket part is achieved in a clearly defined position which allows no other alternative. For mounting only a few manual steps are necessary which moreover take place only at one of these locations, whilst the connection at the other location is already reached by simply pushing in or hooking on the console bracket part.
Of advantage is the separation as regard forces of the axle lift from the chassis components which are involved in the dynamic driving process since the support of the console bracket housing the force element of the axle lift takes place solely on the base body of the support, and not on those parts of the axle suspension which are involved in the dynamic driving process. It is particularly avoided that a part of the considerable pressure reaction forces acting on the console bracket part is transferred to the bearing bolt which connects the axle link for pivotal movement to the support.
During the assembly in the basic position which is simple to execute, a further console bracket part on which the force element of the axle lift is supported can already be connected to the first console bracket part. As an alternative however it is also possible to fasten the further console bracket part only subsequently on the first console bracket part.
With goods vehicles for which the axle suspension is primarily used, different types of vehicles also require different driving heights. Driving height means to the technical expert the distance maintained by the valve of the air spring between the underside of the longitudinal beam of the vehicle, and the center point of the axle. In the schedule of an axle manufacturer the same axle link is combined with different height supports, air spring bellows as well as differently angled air spring console brackets. The pivotal range, thus the minimal and maximum outlet angle of the link from the support, also differs from chassis to chassis. Sometimes this range lies higher, sometimes it lies lower. As a result of these conditions and for the widest possible useful field the axle lift also has to be adaptable in its dimensions relevant for functioning.
In order to achieve this adaption through a corresponding arrangement of the force element, it is proposed in one configuration that the second console bracket part can be fastened on the first console bracket part in at least two different positions. For this, a one-piece shaped sheet metal part can be a constituent part of the first console bracket part and is comprised of two parallel side arms and a web section connecting these to one another on which the plug-in or hook connection is formed. With this type of construction the side arms of the first console bracket part are each provided with a number of openings for selectively passing through a screw connector with the second console bracket part. In this way the second console bracket part which holds the diaphragm cylinder can be fastened in at least two different positions on the first console bracket part in order to adapt to the relevant required geometry of the axle lift.
With a further development it is proposed that a one-piece shaped sheet metal part is a constituent part of the second console bracket part and is comprised of two parallel side arms and a cross wall connecting these together and on which the supporting means for the force element is located, and that the side arms are each provided with at least one opening for pushing through the screw connector to the first console bracket part.
For a favorable introduction of the lifting reaction forces acting on the console bracket onto the support it is further proposed that the upper side of the web section is provided with a supporting surface for bearing against the underside of the support.
With a further development it is proposed that the plug-in or hook connection is formed to engage horizontally into the support wherein the further connection means has horizontally no play or at maximum a play which is lower than this horizontal engagement.
The adjustment of the axle lift to the relevant chassis geometry can be undertaken alternatively or additionally also on the axle link where during operation of the force element its lifting force impacts on the axle link in order to lift this. With further developments of the invention measures are therefore proposed to allow a force absorbing member mounted on the axle link for the lifting force to be fitted simply in more than just one position.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details and advantages of the invention are apparent from the following description of embodiments with reference to the associated drawings. They show:
FIG. 1 in a perspective mainly lateral view, parts of an air-sprung axle suspension including a support, as well as an axle link pivotally mounted therein, but without illustrating the axle itself;
FIG. 2 a the area of the support and the axle lift fastened thereon including a first console bracket part of the axle lift mounted underneath;
FIG. 2 b the objects according to FIG. 2 a with a second console bracket part additionally fastened thereon;
FIG. 3 a perspective view of the first console bracket part;
FIG. 4 a second embodiment of an axle link with a force absorbing member which can be fastened thereon in different positions; and
FIG. 5 a further embodiment of an axle link with a force absorbing member which can be fastened thereon in different positions.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows the axle suspension of a goods vehicle trailer or semi-trailer. Supports 2 are fastened on the left and right underneath the vehicle frame, preferably by welding the upper edge 4 of the support to the underside of the longitudinal beam of the vehicle frame. An axle link or trailing arm 5 for the vehicle axle is mounted for pivotal movement in each support 2 , each pivotal about a bolt 6 .
Each axle link or trailing arm 5 is formed as a cast part of cast steel or light metal. The front end of each axle link 5 is formed as an eye in which a rubber bush or a rubber-steel bush is seated. The bolt 6 extends through this bush as well as through the side walls 7 a , 7 b of the support 2 . Air spring bellows of an air suspension formed in the conventional way are each fastened at the rear end of the axle links 5 (not shown in the drawing). Such air spring bellows are generally supported from underneath against the vehicle frame.
Each axle link 5 is connected in an axle socket 3 to the axle body of the vehicle axle. The axle body, preferably an axle rod, is designed to pass from the left to the right side of the vehicle and supports at its two ends the wheel bearings of the vehicle wheels.
To adjust the track and forward running of the vehicle axle the supports 2 are provided with adjusting devices 8 .
The base body of the support 2 is designed with a U-shaped cross-section and is comprised of the two side walls 7 a , 7 b which are substantially parallel to one another, and of an end wall 14 which points forwards in the driving direction. The base body of the support 2 is open to the back and downward. It can be designed in one piece in an advantageous technical manufacturing process wherein all its walls, thus the two side walls 7 a , 7 b and the front end wall 14 , are sections of one and the same sheet metal strip. This sheet metal strip of for example steel plate is shaped in a cold shaping process, e.g. in a stamping or stamping-bending process into the shaped sheet metal part which is shown in the drawing. A support made from cast material is also conceivable.
The side walls 7 a , 7 b are provided with holes. The bolt 6 passes through these holes as well as through the front eye of the axle link 5 and thus forms the pivotal axis of the axle link.
In order to lift the air-sprung vehicle axle shown in FIG. 1 in the driving position into its raised position if this axle is not required for the driving operation, an axle lift is provided with a lifting device 9 which is mounted underneath the support 2 . A constituent part of the lifting device 9 is a diaphragm cylinder 11 which is operated by compressed air and which is mounted rigidly on the support 2 by means of a console bracket 12 whose individual parts will be explained in further detail below. The console bracket 12 is provided with a supporting means 10 for fastening the diaphragm cylinder 11 . Constituent parts of the supporting means 10 are screws 16 which are mounted on either side of an opening 13 on the console bracket and which fasten the diaphragm cylinder rigidly to the console bracket 12 .
The axle link 5 of the axle suspension is provided on its underside with a force absorbing member 15 on which a rolling surface 15 A is formed to take up the lifting force. The force absorbing member 15 is designed here in block fashion. It is hung by a hook from below in an opening of the axle link, and is secured at the same time by a screw.
The diaphragm cylinder 11 is the force element of the axle lift. Its housing is supported rigidly on the console bracket 12 by means of the screw connectors 16 . A part of the diaphragm cylinder 11 hereby projects upwardly inclined through an opening 13 in the console bracket. In this region there is an axial guide 19 for a piston rod 18 which passes out from the diaphragm cylinder 11 and is driven by the compressed medium in the diaphragm cylinder. The axial guide 19 can be a plastics bush which guides the piston rod 18 axially over a certain part of its length. At its end the piston rod 18 is provided with a roller 20 mounted on an anti-friction bearing.
During actuation of the force element 11 by means of compressed air, through the unit of piston rod 18 and roller 20 which together form a force transmission unit, an upwardly inclined pressurised force is directed against the opposing force absorbing member 15 on the axle link 5 . The axle link 5 is thereby pivoted upwards about the bolt 6 , and the axle is raised.
Away from the axle lift operation, the force transmission unit 18 , 20 composed of the piston rod and roller, is drawn back towards the diaphragm cylinder 11 whereby the roller 20 has no more contact with the force absorbing member 15 and the axle link 5 can move freely according to the driving conditions.
The rolling surface 15 A on the force absorbing member 15 , here formed as a block, is designed as an involute curved concave relative to the roller 20 . The path of the involute is such that the surface normal of that site at which the roller 20 bears against the rolling surface 15 A coincides precisely with the longitudinal axis of the piston rod 18 . Through this alignment and geometric configuration of the component parts involved the result is that no or in any case very slight transverse forces are exerted on the roller 20 and thus on the piston rod 18 . Equally it can be advisable to guide the piston rod 18 axially for which the axial guide 19 is fastened on the housing of the diaphragm cylinder close to the exit of the piston 18 out from the housing of the diaphragm cylinder 11 .
The console bracket 12 of the axle lift is designed in two parts. It consists essentially of a first console bracket part 31 and a second console bracket part 41 . The first console bracket part 31 is fastened directly on the support 2 in a non-changeable position, and transfers the reaction forces which are connected with lifting to this support. On the other hand the second console bracket part on which the supporting means 10 of the diaphragm cylinder 11 and thus of the force element of the axle lift are located, is fastened on the first console bracket part 31 , and thus only indirectly on the support.
The construction and fastening of the console bracket parts will be explained in further detail below with reference to FIGS. 2 a , 2 b and 3 .
The first console bracket part 31 consists essentially of a shaped sheet metal part 32 and an axially secured rod 33 which is only indicated along its center line in FIG. 2 a . The console bracket part 31 is connected to the support 2 at two sites located horizontally at a distance from one another. As a front connection in the driving direction, a plug-in connection or hook connection 36 A serves for engaging in the end wall 14 of the support. The connection 36 A is thus shaped so that it engages through simple keyed connection in a correspondingly shaped structure in the support 2 , namely here in an opening in the lower region of the end wall 14 of the support.
The shaped sheet metal part 32 of the console bracket part 31 is comprised of two legs 35 which in the assembled state are mounted outside on the side walls 7 a , 7 b of the support, and of a web section 36 which connects these two. The plug-in or hook connection 36 A which engages horizontally in the opening in the support 2 is located on the web section 36 .
The web section 36 extends transversely through beneath the support 2 wherein its upper side serves as the support face which is supported from below against the support 2 , and thus diverts the major part of the pressure reaction forces which occur during lifting of the axle, in a direct route into the support 2 . As an alternative the pressure reaction forces can also be introduced into the support 2 exclusively or predominantly via the plug-in and hook connection 36 A and/or via the other connection at a distance therefrom.
At the rear end of the shaped sheet metal part 32 its legs 35 are each provided with a bore 34 which aligns flush with the bore 34 in each other legs 35 . The bores 34 are arranged so that when the console bracket part 31 is fitted they align flush with the bores 24 in the side walls 7 a , 7 b of the support 2 . The rod 33 which is a constituent part of the console bracket part 31 is passed through these in total four bores 24 , 34 and is axially secured. For axial securing, the rod 33 is provided at its one end with an enlarged head, and at its other end with a ring groove on which a securing clip 37 ( FIG. 1 ) can be fitted.
Fastening the first console bracket part 31 on the support 2 is carried out by moving the console bracket part forwards until the plug-in and hook connection 36 A formed at the front passes into the opening in the end wall 14 of the support 2 . Then possibly by slightly lifting the sheet metal shaped part 32 whose bores 34 are brought to overlap with the bores 24 of the support, the rod 33 is passed through and secured axially by means of the securing clip 37 . The front connecting means in the form of the plug-in or hook connection can then no longer be loosened since the rear connecting means spaced horizontally from the front connecting means and in the form of the rod 33 prevent this. For this purpose the correspondingly small tolerance of the rod 33 and bores 24 , 34 are required. The horizontal play which is possible there is less than the horizontal engagement of the plug-in or hook connection 36 A at the front on the console bracket part 31 .
Alternatively the plug-in and hook connection can also take place in the side walls 7 a , 7 b of the support 2 . It is likewise conceivable that the other connection, arranged at a distance, serves only to secure several plug-in or hook connections, and undertakes no function supporting the console bracket.
According to FIG. 2 b , the other console bracket part 41 also consists substantially of a one-piece shaped sheet metal part 42 which is comprised of two side arms 45 parallel to one another, and a cross wall 36 connecting these together, wherein the diaphragm cylinder 11 is supported on this cross wall 46 by means of the screw connections 16 .
In order to adjust the second console bracket part 41 in relation to the first console bracket part 31 the legs 35 are each provided with a pattern of holes. Screws 49 can be selectively pushed through these holes 39 ( FIG. 1 ) in order thus to be able to fasten the second console bracket part on the first console bracket part in one of several optional available positions and to adapt the path of movement of the axle lift to the relevant chassis geometry.
Constituent parts of the second console bracket part 41 are through-guides 44 serving as studs on both side arms 45 which always engage in an oblong hole 38 in the relevant legs 35 of the first console bracket part 31 . The oblong holes 38 are not straight but follow an arc whose reference center point coincides approximately with the bolt 6 .
Adjusting the axle lift can be carried out subsequently and individually by the vehicle manufacturer after the first console bracket part 31 has been first mounted on the support 2 in its non-variable basic position. Alternatively the possibility exists of connecting the two console brackets parts 31 , 41 in a specific relative position which is suitable for the relevant type of chassis prior to attaching the axle lift on the support. The thus prepared console bracket comprising the two console bracket parts 31 , 41 is then fastened as a unit underneath the support 2 without the risk of an accidental faulty fitting.
Adapting the axle lift and more particularly its movement path to the relevant chassis geometry can however also take place on the sides of the axle link, which is shown in two different embodiments in FIGS. 4 and 5 .
According to FIG. 4 the force absorbing member 15 mounted underneath the axle link 5 is provided with one arm 52 each on either side of the axle link 5 . This comprises structures which permit fitting at different heights, here three different heights. The structures consist in slits 53 open on one side as well as bores 54 in the arms 52 . These are selectively connectable with a corresponding stud 55 or a bore 56 of the axle link 5 in order thus to adjust the position of the rolling face 15 A which is formed on the force absorbing member 15 so that during operation of the axle lift an alignment with the force transmission unit consisting of the piston rod 18 and roller 20 is set. The force absorbing member 15 is thus always arranged in an extension of the active direction of the force element 11 .
With the embodiment according to FIG. 5 , the force absorbing member 15 is designed in two parts comprising a base element 60 which can be screwed to the axle link 5 only in one position, and a block 61 which is adjustable in several positions relative to the base element 60 and on which the rolling face 15 A is formed.
LIST OF REFERENCE NUMERALS
2 Support
3 Axle socket
4 Edge
5 Axle link (trailing arm)
6 Bolt
7 a Side wall
7 b Side wall
8 Adjusting device
9 Lifting device
10 Supporting means
11 Force element, diaphragm cylinder
12 Console bracket
13 Opening
14 End wall
15 Force absorbing means
15 A Rolling surface
16 Screw
18 Piston rod
19 Axial guide for piston rod
20 Roller
24 Bore
31 First console bracket part
32 Shaped sheet metal part
33 Rod
34 Bore
35 Leg
36 Web section
36 A Plug-in or hook connection
37 Securing clip
38 Oblong hole
39 Hole pattern
41 Second console bracket part
42 Shaped sheet metal part
44 Through-guides
45 Side arm
46 Cross wall
49 Screw
52 Arm
53 Slit
54 Bore
55 Stud
56 Bore
60 Base element
61 Block | An axle suspension for a vehicle axle guided by a trailing arm and also, furthermore, an axle lift for a vehicle axle are proposed. The axle lift includes a force element ( 11 ), a pressure transmission means ( 18, 20 ) which is movable towards an axle link ( 5 ) of the vehicle axle by actuation of the force element, and a bracket ( 12 ). The bracket ( 12 ) is provided with a supporting means ( 10 ) for the force element ( 11 ) and the pressure reaction forces acting on the latter and, in addition, for the fastening to a support ( 2 ) is provided with a bracket part ( 31 ), on which a plug-in or hook connection ( 36 A) for engagement in the support ( 2 ) is formed. With the aim of being able to fit the bracket ( 12 ) in a fixed basic setting on the support ( 2 ) with just a few actions, it is proposed that the bracket part ( 31 ), at a distance from the plug-in or hook connection ( 36 A) thereof, is provided with at least one further connecting means ( 33 ), which is designed for engagement in the support ( 2 ). | 1 |
BACKGROUND OF THE INVENTION
The present invention is directed to a method and an apparatus for the heat treatment of a workpiece and in particular, for the heat treatment of a workpiece having a cavity formed therein. More particularly, the present invention is directed to a method and an apparatus for supporting an outer race member of a universal joint during a heat treatment operation.
It is often difficult to obtain a quality hardened part when the part has cavities formed in it, due to the nature of the heat treating operation used to harden the parts. Typically, a part is heat treated by heating the part in a carborizing atmosphere to a predetermined temperature and subsequently quenching the part with a cooling fluid. If the part is positioned so that the cavity formed in the part opens upwardly, the cooling fluid used in the quenching operation fills the cavity and the cooling fluid is carried out of the quench tanks after the quenching operation is complete. Therefore, an additional operation is required to remove the cooling fluid from the part and to replace the cooling fluid in the quench tank. A portion of the cooling fluid is wasted during this additional operation.
Alternatively, when the workpiece is heat treated with the cavity disposed such as to open downwardly, the carborizing atmosphere used during the heating step of the heat treatment operation becomes trapped in the upper portion of the cavity during the quench segment of the heat treatment. The carborizing atmosphere, therefore, prevents the cooling fluid from entering the cavity, preventing the workpiece from being uniformly quenched. In particular, the interior surface of the cavity may not be sufficiently hardened by the heat treatment process.
The above described problem exists for all workpieces having cavities, but is particularly serious when the interior surface of the cavity performs a load bearing function, since insufficient hardening of a load bearing surface may result in premature failure of the part.
There are many universal joints in common commercial use which include an outer race member having a cavity formed therein, and an inner race member disposed within the cavity. Various means, well known in the art, are used for interconnecting the inner race member with the outer race member, such as bearing balls, which transfer torque between the inner and outer race members. The inner surface of the cavity experiences substantial loads when torque is transferred between the inner and outer race members and, therefore, must be adequately hardened so as to provide a long life for the outer race member.
To avoid the above described problems during a heat treatment operation, the method and the apparatus of the prior art used for heat treating the outer race members of the universal joints and similar workpieces involved placing the outer race member or workpiece in a horizontal position such that the cavity opened horizontally. This avoids the entrapment of either the carborizing atmosphere or the oil within the cavity. However, in practice, when an outer race member is heat treated in a horizontal position a substantial amount of material movement takes place within the part. This material movement results in an undesirably high rejection rate of outer race meabers which have already been manufactured and heat treated.
What is needed, therefore, is a method and an apparatus for the even and reliable heat treatment of a workpiece having a cavity and, particularly, of the outer race member of a universal joint.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus for the even and reliable heat treatment of workpieces having cavities and, more particularly, for the heat treatment of the outer race member of a universal joint.
According to the method of the present invention, the workpiece is mounted to the upper end of an elongated vertically disposed post by inserting the upper end of the elongated vertically disposed post into the cavity of the workpiece. The outer race member is heated to a predetermined temperature level in a carborizing atmosphere, the cavity being in communication with the environment external to the outer race member by means of a passage formed in the elongated vertically disposed post. Finally, the outer race member is quenched with a cooling fluid to rapidly cool the outer race member.
The apparatus according to the present invention includes a horizontally disposed base, an elongated vertically disposed post interconnected with the horizontally disposed base and extending upwardly therefrom, and a passage extending longitudinally of the elongated vertically disposed post. A workpiece is mounted to the upper end of the elongated vertically disposed post by the insertion of the upper end of the elongated vertically disposed post into the cavity of the workpiece. The passage in the elongated vertically disposed post provides communication between the cavity of the workpiece and the environment external to the workpiece.
In the preferred embodiment, the apparatus includes one or more plates, each being constructed of a plurality of tubular portions forming sockets therein, and a plurality of web portions interconnecting the tubular portions, such as to form an array of parallel sockets. A plurality of the elongated posts are provided, each having a lower end and an upper end opposite the lower end. A plug is formed at the lower end of each of the plurality of elongated vertically disposed posts for selective insertion into one of the sockets. A passage is provided in each of the plurality of the elongated vertically disposed posts for interconnecting the upper end thereof with an intermediate portion thereof. When more than one plate is used, a plurality of support posts are provided for interconnecting a first plate with a second plate, each of the support posts having a plug disposed at an upper end and a plug disposed at a lower end for selective insertion, respectively, in sockets of the first and second plates.
A principal object of the present invention is to provide a reliable method and apparatus for the heat treatment of a workpiece having a cavity.
Another object of the present invention is to provide a reliable method and apparatus for the even heat treatment of an outer race member of a universal joint.
Yet another object of the present invention is to provide a method and apparatus for the heat treatment of an outer race member of a universal joint such that the cavity of the outer race member is downwardly opened during the heat treatment process.
These, and the many other objects, features, and advantages of the present invention will become apparent to those skilled in the art when the following detailed description of the preferred embodiment is read in conjunction with the drawings appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings appended hereto, wherein like reference numerals refer to like components throughout:
FIG. 1 is a top view of an apparatus for the heat treatment of an outer race member of a universal joint according to the present invention, with parts removed;
FIGS. 2 and 3 are sectional views taken, respectively, approximately along lines 2--2 and 3--3 of FIG. 1; and
FIG. 4 is a partial front elevational view, with parts cut away, showing the apparatus of FIG. 1, with certain modifications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, an apparatus 100 according to the present invention for racking an outer race member 30a or 30b of a universal joint for purposes of heat treating is illustrated in detail.
As shown in FIG. 1, the apparatus 100, according to the present invention, includes a base 10 and a plurality of lower posts 20 and upper posts 50, the lower and upper posts 20 and 50 extending upwardly from the base 10 for the mounting thereto of the outer race member 30a or 30b.
More particularly, the base 10 is a unitary member formed of a suitable metallic or composite material. The base 10 has a plurality of sockets S 1 ,1 through S 5 ,5 arranged in a suitable array such as a rectangular array, to define possible interconnection points for the plurality of lower and upper posts 20 and 50, in a manner described herein. The sockets S 1 ,1 through S 5 ,5 are parallel to each other, as shown in FIGS. 2 and 3. Furthermore, the sockets S 1 ,1 through S 1 ,1 are preferably tapered for a purpose to be described later. In the preferred embodiment, the sockets S 1 ,1 through S 5 ,5 of the base 10 are tubular portions which are interconnected by webs 14 with each other and with a perimetric frame 12, the perimetric frame completely surrounding the array of sockets. The base 10 is further provided with a flat bottom surface 16 and a flat top surface 18, as shown in FIGS. 2 and 3.
As indicated above, a plurality of lower posts 20 extend upwardly from the base 10. Each lower post 20 is provided at its lowermost end with a plug 22, as shown in FIG. 3, extending downwardly therefrom for selective insertion in one of the plurality of sockets S 1 ,1 through S 5 ,5 of the base. The plug 22 is tapered so as to cooperate with the taper of the socket with which it is interconnected to secure the lower post 20 in a fixed position. As illustrated, the plug 22 may be t-shaped in cross-section.
Each lower post 20 further includes an elongated trunk 24 extending upwardly from the plug 22. A plurality of ears or flanges 26 extend radially outwardly and longitudinally upwardly of the uppermost end of the elongated trunk 24.
The outer race member 30a, well known in the art, is mounted to the uppermost end of the elongated trunk 24, as shown in FIGS. 1 and 4, by insertion of the upper end of the elongated trunk 24 into a cavity 28 of the outer race member. The outer race member 30a is thereby supported by the lower post in a vertical position with a shaft 32 of the outer race member 30a shown only in FIG. 4 of the drawing, extending vertically upwardly therefrom. The ears or flanges 26 of the elongated trunk 24 of the lower post 20 cooperate with the outer race member to removably secure the outer race member 30a in a fixed position relative to the base 10. The ears 26 further cooperate with the outer race member 30a to support the outer race member in a position such that a base 29 of the cavity 28 is disposed a short distance above an uppermost end 31 of the elongated trunk 24 of the lower post 20.
Each of the plurality of lower posts 20 is provided with a passage 34, as depicted in FIGS. 1 and 3, extending partially along the longitudinal axis of the elongated trunk 24 from the uppermost end 31 of the elongated trunk 24 to an intermediate portion thereof. The passage 34 is provided with an opening 36 at the uppermost end 31 of the elongated trunk 24, as depicted in FIG. 3. The opening 36 communicates the passage 34 with the cavity 28 of the outer race member 30a.
The elongated trunk 24 of each lower post 20 is further provided with a boss 38 extending radially therefrom at an intermediate location between the ears or flanges 26 and the plug 22. An aperture 40 is formed through the center of the boss 38, as shown in FIG. 3, the aperture 40 opening into the passage 34. One end of a pipe 42 is fitted in the aperture 40 and is interconnected with the boss 38 by means of welds 44. The pipe 42 is bent into an L-shape and extends first radially outwardly from the boss 38, and then upwardly therefrom. The pipe 42 is provided with an opening 46 at its end furthest from the boss 38, the opening communicating the passage 34 with the environment external of the outer race member 30a.
As stated above, a plurality of upper posts 50 also extend upwardly from the base 10. As illustrated in FIG. 2, each of the upper posts 50 are provided with a plug 52 for removable interconnection of the upper post with one of the sockets S 1 ,1 through S 5 ,5 of the base 10 and an elongated trunk 54 extending upwardly therefrom. Each of the upper posts 50 has a plurality of ears or flanges 56 similar to the plurality of ears or flanges 26 of the lower posts 20. An outer race member 30b may be mounted to the upper post 50 in a manner similar to that described above for the mounting of an outer race member 30a to a lower post 20, as depicted in FIGS. 1 and 4. However, the elongated trunk 54 of the plurality of upper posts 50 is substantially longer than the elongated trunk 24 of the plurality of lower posts 20 so as to support an outer race member 30b at a greater height relative to the base 10 than an outer race member 30a supported by one of the plurality of lower posts 20 as shown in FIG. 4. The length of the elongated trunks 24 and 54 are preselected such as to permit a dense packing of the outer race members 30a and 30b in a staggered triangular array. For example, a total of thirteen outer race members 30a and 30b may be mounted to the base 10 by interconnecting a lower post 20 with each of the nine sockets S 1 ,1, S 1 ,3, S 1 ,5, S 3 ,1, S 3 ,3, S 3 ,5, S 5 ,1, S 5 ,3, and S 5 ,5 and by interconnecting the upper posts 50 to each of the four sockets S 2 ,2, S 2 ,4, S 4 ,2, and S 4 ,4.
As best shown in FIG. 2, each of the plurality of upper posts 50 are provided with a longitudinal passage 64 having an opening 66 disposed adjacent the upper end 61 of the elongated trunk 54 thereof. Each of the plurality of upper posts 50 has a boss 68, and an aperture 70 therethrough, the aperture 70 extending into the longitudinal passage 64. A pipe 72 is fitted into each of the apertures 70 of the plurality of upper posts 50 and is welded to the boss 68 thereof by welds 74. Each of the pipes 72 is L-shaped and extends radially outwardly of the upper post 50 and then upwardly therefrom.
An opening 76 is provided at the upper end of the pipe 72, remote from the boss 68. The openings 66 and 76 communicate the cavity 28 of an outer race member 30b mounted to the upper end of the upper post 50 with the environment external of the outer race member 30b.
As shown in FIG. 4, the apparatus 100 according to the present invention may be extended upwardly for the mounting of additional outer race members 30a and 30b by the provision of an additional base 10' substantially identical to the base 10 described previously. As indicated in FIG. 4, the additional base 10' has a plurality of sockets, only the socket S 4 ,4 ' being shown in the drawing, interconnected by a plurality of webs 14' with each other and with a perimetric frame 12'. The additional base 10' is further provided with a flat bottom surface 16'.
A plurality of support posts 80, only one of which is shown in the drawing, are provided for mounting the additional base 10' to the base 10. Each support post 80 has an elongated trunk 82 provided with a lower plug 84 similar to the plugs 22 and 52, respectively, of the lower posts 20 and the upper posts 50. The lower plug 84 is removably insertable in a socket, for example the socket S 4 ,4 of the base 10. The elongated trunk 82 is stabilized in position, relative to the base 10, by means of a radial flange 86 disposed adjacent to the lower plug 84, the radial flange 86 cooperating with the top surface 18 of the base 10.
Each support post 80 is also provided with an upper plug 88 removably insertable in one of the sockets, for example the socket S 4 ,4 ' of the additional base 10'. Unlike the lower plug 84 and the plugs 22 and 52, the upper plug 88 of the support post 80 is not tapered. A radial flange 90 extends from the elongated trunk 82 to the support post 80 adjacent the upper plug 88. The radial flange 90 cooperates with the bottom surface 16' the additional base 10' to provide a stable interconnection between the support post 80 and the base 10'.
The apparatus 100 of the present invention may be modified to include more additional bases 10' , each mounted by a plurality of support posts 80 to be disposed above an additional base 10' in the above described manner. A plurality of lower posts 20 and upper posts 50, not shown, extend upwardly from each of the additional bases 10'.
To use the apparatus 100 of the present invention, a plurality of outer race members 30a and 30b are mounted, as indicated above, to the uppermost ends of the plurality of lower posts 20 and upper posts 50. The apparatus 100, together with the plurality of outer race members 30a and 30b is heated in a carborizing atmosphere and subsequently quenched with a suitable cooling fluid, such as oil, to heat treat the plurality of outer race members 30a and 30b. During the heat treating operation, the passages 34 and 64 in the plurality of lower posts 20 and upper posts 50, respectively, communicate the cavities 28 of each of the outer race members 30a and 30b with the environment external to the cavity such as to vent carborizing atmosphere from the cavities. The passages 34 and 64 thereby permit admission of the cooling fluid into the cavity during the quenching operation. Furthermore, since the cavity 28 opens downwardly, the cooling fluid will not collect in the cavity so as to be removed from the quenching tank when the apparatus of the present invention is removed from the quenching tank.
The above detailed description is merely exemplary of the present invention. For example, while an array of twenty-five sockets is shown in the drawing, in practice, a much larger array of sockets, such as a 25×20 rectangular array, may be used. The number of sockets which are provided in the base 10 and the number of additional bases 10' will depend on the proportions of the ourter race member 30a and 30b, or other workpiece used in conjunction with the apparatus 100, on the proportions of the heat treatment apparatus, and the weight of the outer race member 30a or 30b or other workpiece.
Still other variations and modifications may be made from the detailed description of the preferred embodiment without departing from the spirit of the present invention. Such modifications and variations are included within the intended scope of the claims appended hereto. | A method and an apparatus for the heat treatment of a workpiece, particularly an outer race member of a universal joint, having a cavity formed therein. The apparatus includes a horizontally disposed base and at least one elongated vertically disposed post extending upwardly therefrom with a passage extending at least partially longitudinally therethrough. The workpiece is mounted on the elongated vertically disposed post by insertion of the upper end of the elongated vertically disposed post into the cavity, the passage providing a venting of the cavity during the heat treatment operation. The method provides for mounting the outer race member to the upper end of an elongated vertically disposed post by insertion of the upper end of the post into the cavity of the workpiece, heating the workpiece to a predetermined temperature level, communicating the cavity in the workpiece with the environment external to the workpiece by a passage means formed in the elongated vertically disposed post, and quenching the workpiece with a cooling fluid to rapidly cool the outer race member. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/237,803, filed Oct. 4, 2000. Application Ser. No. 60/237,803 is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This description generally relates to the field of electrical circuit inspection. More particularly, the field of interest involves systems and methods for fabricating and inspecting electrical circuit conductors in electrical circuits.
BACKGROUND OF THE INVENTION
[0003] The production of printed circuit boards is an expensive undertaking, and many extraordinary measures are routinely taken to ensure the highest possible production quality. Automated optical inspection (AOI) harnesses the power, speed, and reliability of computer technology to assist with the task of inspection of printed circuit boards for defects. Existing automated optical inspection (AOI) systems, such as the PC-14 Micro™ and Blaser™ AOI systems, are available from Orbotech of Yavne, Israel.
[0004] Existing AOI systems that just inspect conductor width, however, do not provide information for evaluating the cross-section of the conductors.
[0005] As used herein, the term “printed circuit board” will be understood to refer in general to any electrical circuit on any substrate, including printed circuit boards, multi-chip modules, ball grid array substrates, integrated circuits and other suitable electrical circuits.
SUMMARY OF THE INVENTION
[0006] A general aspect of the present invention relates to employing a combination of inspection inputs or attributes for the width of a conductor along a top surface and for the width of a conductor along a bottom surface thereof to determine an inspection attribute that may indicate the presence of a defect in a conductor or in a manufacturing process used to fabricate an electrical circuit.
[0007] A more particular aspect of the present invention relates to an automated optical inspection system operative to inspect electrical circuits to determine the width of a top surface of conductors forming the circuit at a multiplicity of locations, the width of a bottom surface of conductors forming the circuit at a multiplicity of locations, and the slope of the side walls of conductors, or other defects in the shape of conductor side walls, forming the circuit at a multiplicity of locations.
[0008] Another more particular aspect of the present invention relates to a system and method for optically inspecting electrical circuits and calculating therefrom impedance values for conductors forming the electrical circuit.
[0009] Another more particular aspect of the present invention relates to a method of producing printed circuit boards, whereby production and/or fabrication process control decisions (such as whether a defect exists in a conductor or in a manufacturing process) are based on inspection outputs indicative of the conductor dimension along the top surface and bottom surface respectively, or the slope of the sides of conductors.
[0010] The above and other aspects of the invention are achieved by a system, described in detail below, in which a laser scanner is provided to scan a laser beam across an electrical circuit being inspected. The laser produces a beam which has sufficient energy to cause fluorescence (also referred to herein as luminescence) of the substrate on which conductors are formed. In addition, the beam is reflected by copper conductors which typically have a higher work function than the substrate and do not fluoresce under illumination of the laser beam. The reflected and fluorescent light is collected and the respective intensities of the reflective and fluorescent light are analyzed. Fluorescent light provides an indication of the width of a conductor along its bottom surface, while the reflected light (another attribute) provides an indication of the width of the conductor along its top surface. Comparison of the respective widths of the bottom surfaces and top surfaces of the conductors provides an indication of the slope of the side-walls of a conductor.
[0011] The top and bottom dimensions can be used in combination to provide an inspection attribute for a single point or at various sampling points along the length of conductors, and can be used for various analyses of characteristics of the electrical circuit. For example, information about the slope of the side walls of conductors may be used to calculate a cross sectional dimension of an electrical circuit at various sampling points which can be used to derive an impedance value for a conductor. Additionally, statistical information about uniformity in the respect widths of conductors along their top and bottom surfaces may be used to indicate various flaws in etching processes.
[0012] The above and other aspects of the invention will be more fully understood and appreciated when read in the light of the detailed description provided below, and the enclosed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a functional block diagram of an automated optical inspection system operative to inspect electrical circuits for defects in accordance with a preferred embodiment of the present invention.
[0014] [0014]FIG. 2 is a simplified representation of a conductor on a substrate, shown in cross-section.
[0015] [0015]FIG. 3 shows a signal generated in correspondence to an amount of detected luminescent light generated when the conductor and substrate of FIG. 2 are scanned with a laser.
[0016] [0016]FIG. 4 shows a signal generated in correspondence to an amount of detected reflective light generated as in FIG. 3.
[0017] [0017]FIG. 5 is a report of distribution of top surface and bottom surface dimension of conductors in an electrical circuit in accordance with a preferred embodiment of the present invention.
[0018] [0018]FIG. 6 shows, in highly simplified schematic form, a system for manufacturing electrical circuits according to an embodiment of the invention.
[0019] [0019]FIG. 7 is a flow diagram for explaining the processing of the system shown in FIG. 6.
[0020] [0020]FIG. 8 shows, in highly simplified schematic form, another system for manufacturing electrical circuits according to an embodiment of the invention.
[0021] [0021]FIG. 9 is a flow diagram for explaining the processing of the system shown in FIG. 8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] Using the above-identified figures, the invention will now be described with respect to various embodiments of the invention. Although many specificities will be mentioned, it must be emphasized that the scope of the invention is not be taken to be that of only the embodiments described herein, but should be construed in accordance with the claims appended below.
[0023] In FIG. 1, automated optical inspection system 10 is operative to inspect electrical circuits for defects in accordance with an embodiment of the present invention.
[0024] AOI system 10 suitably is a V- 300 automated optical inspection system available from Orbotech Ltd., of Yavne Israel. In FIG. 1, reference numeral 12 indicates a source of radiant energy; reference numeral 14 indicates a beam of radiant energy; reference numeral 16 indicates a portion of a printed circuit board substrate under inspection; reference numeral 18 indicates a conductor; reference numeral 20 indicates a substrate on which the conductor 18 is disposed; reference numeral 22 indicates a device such as a rotating polygonal mirror that scans the beam 14 across the printed circuit board 16 ; reference numeral 24 indicates a luminescence (also referred to herein as fluorescence) collector; and reference numeral 34 indicates a reflectance collector.
[0025] Operation of certain aspects of system 10 are described in U.S. Pat. No. 5,216,479, and are readily grasped by those familiar with this field. Thus, a highly detailed description of the operation of AOI system 10 is omitted here in favor of a brief overview.
[0026] The source of radiant energy 12 may be a laser, such as any suitable CW or solid state laser, and preferably is a He:Cd laser, available from Kimmon Electric Company of Japan, producing coherent light in the blue spectrum, at about 442 nm. Substrate 20 may, e.g., be a fiberglass or organic substrate.
[0027] The beam 14 is scanned across the circuit portion 16 , and the collectors 24 and 34 are kept operationally positioned to collect their respective types of light at the point at which the beam 14 impinges on the circuit portion 16 . To this end, it is convenient if the collectors 24 and 34 are linear in a main scanning direction of the beam 14 , although this is not essential. The collectors 24 and 34 are shown in FIG. 1, in highly simplified form, as point collectors instead of linear collectors for the sake of ease of illustration.
[0028] It will be appreciated that the collectors, sensors, and processors mentioned above may together be thought of as an inspection functionality.
[0029] [0029]FIG. 2 shows a cross section of a conductor 18 on a substrate 20 . Reference numeral 35 indicates an upper, substantially flat surface of conductor 18 . The upper surface 35 of conductor 18 has shoulders 19 on either side of it, sloping down in some shape to the substrate 20 . Reference numeral 17 indicates a lower, bottom surface of conductor 18 .
[0030] The width of conductor 18 at its top surface 35 may be referred to hereinafter as a top surface width, or top width, or also a surface dimension.
[0031] The width of conductor 18 at its bottom surface 17 may be referred to hereinafter as a bottom surface width, or bottom width, or also as a footprint dimension.
[0032] When the spot of beam 14 impinges on the substrate 20 at a location free of conductor 18 , a localized part of the substrate fluoresces, giving off luminescent light collected by luminescence collector 24 and sensed by luminescence sensor 26 . At such a location, the reflected light given off by substrate 20 is very low because substrate 20 tends to diffuse the light, and a substantially zero value is output by reflectance sensor 36 .
[0033] When the spot of beam 14 impinges on the substrate 20 at a location where a conductor 18 is present, the conductor does not fluoresce because the work function of the conductor 18 is greater than required to release a photon, due to the quantum effect of illumination by beam 14 . Thus, luminescence sensor 26 outputs a substantially zero value. Conductor 18 , however, is relatively reflective. Reflectance collector 34 therefore collects reflectance and reflectance sensor 36 outputs a value above zero at such a point.
[0034] [0034]FIG. 3 shows a luminescence signal 30 produced by luminescence sensor 26 , indicative of an amount of luminescence emitted by the surface as a beam spot scans over the cross-section of conductor 18 shown. When the beam spot is over the substrate only, the luminescence has a non-zero value. As the spot begins to cross from the exposed substrate to the shoulder portion 19 of the conductor 18 , the detected luminescence decreases rapidly. It will be appreciated that, in the example shown, the beam spot has a finite width, and so as it moves to the shoulder portion 19 from the exposed substrate, the amount of exposed substrate being impinged upon by the beam spot decreases to zero, as does the amount of detectable luminescence. It will also be appreciated that the inspection is not strictly limited to only the conductor itself, but includes also the exposed substrate in the area. The conductor and the exposed substrate in the area may be referred to, for linguistic convenience, as a “conductor location, ” and a conductor location may comprise several pixels in the digital map 31 .
[0035] [0035]FIG. 4 shows a reflectance signal 40 output by reflectance sensor 36 , indicative of an amount of reflectance emitted by the surface as a beam spot scans over the cross-section of conductor 18 shown. When the beam spot is over the substrate only, the reflectance has a substantially zero value. As the spot begins to cross from the exposed substrate to the shoulder portion 19 of the conductor 18 , the detected reflectance increases. Depending on the angle of incidence, the reflectance may reach a maximum value when the spot is impinging on only the top surface 35 , as shown in FIG. 4. When the spot begins to move from the top surface 35 to the shoulder portion 19 , the amount of reflectance that is collected by the reflectance collector 34 decreases quickly, but is greater than zero. This is because the angle of the shoulder portion 19 tends to reflect some of the light in a direction away from the reflectance collector 34 .
[0036] In operation, the sensor 26 may include analogue to digital circuitry processing luminance signal 30 to produce a digital image or map 31 (FIG. 1) of luminance values at selected locations on the surface of substrate 20 . Digital image 31 is supplied to bottom width processor 28 . Likewise, the reflectance sensor 36 may include analogue to digital circuitry processing reflectance signal 40 , to produce a digital image or map 41 (FIG. 1) of reflectance values at selected locations on the surface of substrate 20 .
[0037] The bottom width processor 28 calculates a footprint dimension of one or more conductors 18 at selected conductor locations therealong. This footprint dimension, as can be seen from FIG. 1, is based on the luminance signal 30 . The top width processor 38 calculates a top surface dimension of one or more conductors 18 at selected conductor locations therealong. This top surface dimension, as can be seen from FIG. 1, is based on the reflectance signal 30 .
[0038] The respective outputs of bottom width processor 28 and top width processor 38 may be thought of as different attributes of the conductor, and are provided to an analyzer 42 , which may be operative on several modes. In one mode of operation, analyzer 42 calculates a cross section configuration of conductors based on the respective width dimensions measured for the top surface 35 and bottom surface 32 respectively of conductors 18 . Analyzer 42 may also be thought of as an attribute analyzer
[0039] In another mode of operation, analyzer 42 derives the slope of side walls of conductors 18 , at one or more locations along a conductor, from the respective top surface width and bottom surface widths of conductors 18 at those locations.
[0040] In another mode of operation, analyzer 42 analyzes a distribution of top surface widths and of bottom surface widths of conductors disposed along all or part of the surface of substrate 20 . Analysis of the distribution of top widths and bottom widths provides information which can be used to control etching processes. In a system configuration enabling this mode of operation, a histogram generator 44 may be included in cross section configuration analyzer 42 . Reference is made to FIG. 5 which is a pictorial illustration of a report of the distribution of top surface and bottom surface dimensions of conductors in an electrical circuit in accordance with an embodiment of the present invention.
[0041] As seen in FIG. 5, histogram generator 44 produces a statistical report of the respective width distribution of top surfaces and bottom surfaces for predetermined sampling points along selected conductors. From the histogram, an average top surface width and an average bottom surface width may be determined, along with other useful statistical calculations. These calculations, and the difference between the top and bottom dimensions, are indicative of a shape of conductors, including a slope of conductor side walls. It will be appreciated that information relating to the shape of conductors is useful for understanding and improving photo-lithography and/or etching processes that are employed in manufacturing printed circuit boards.
[0042] Moreover, information relating to the shape of conductors may be employed, for example, to calculate a nominal impedance of conductors. The nominal impedance may be calculated in a manner that will be readily grasped, since impedance is a function of the cross sectional dimension of a conductor.
[0043] The cross sectional shape of the conductor can be approximated in various ways, once the surface and footprint dimensions have been determined. For example, it could be assumed that the shoulders were constituted by straight lines, and that the cross sectional shape was a trapezoid. Thus, the cross sectional area of the conductor (and hence, impedance) could be computed in a simplified manner.
[0044] Another use of information relating to the cross sectional shape of conductors is to control photolithography and/or etching processes in order to obtain conductors having an optimized shape. Ideally, the top surface dimension 35 of conductors 18 should be slightly smaller than the bottom surface dimension 17 in order to maximize the usage of space along the surface of a printed circuit board substrate 20 . Thus if the distribution of top surface width dimensions is too small relative to the distribution of bottom surface width dimensions, then impedance problems are likely to occur since statistically some portions of conductors are likely to have an insufficient volume for efficiently carrying charge. Conversely, if the distribution of top surface width dimensions of conductors is too close relative to the distribution of bottom surface width dimensions, then shoulders 19 (FIG. 2) will typically be bowed inwardly in an exaggerated manner and there will be a high likelihood of cuts along conductors.
[0045] It is thus appreciated that analysis of a width distribution report of top width dimensions and bottom width dimensions, as seen in FIG. 5, is useful in adjusting photolithography and/or etching processes in order to optimize the relative dimensions of top and bottom surfaces of conductors 18 .
[0046] It will be appreciated that the report shown in FIG. 5 is just one possible example of a report 46 that may be generated by the cross section configuration analyzer 42 . For example, a report 46 may include an indication of top and bottom width dimensions of conductors at various locations along a conductor.
[0047] [0047]FIG. 6 shows a fabrication and inspection system, in which a controller 1 controls fabrication activities 9 that produce a printed circuit board 16 from input materials 6 . The printed circuit board 16 is input to the inspection system 10 . The report 46 is provided in a feedback loop to the controller 1 . The report 46 may include surface dimension information, and footprint dimension information. The surface dimension information and footprint dimension information may be thought of as a kind of cross-section information. Based on the cross-section information provided to the controller, the controller may, through an automatic or manual process, adjust the assembly activities 9 in response thereto. That is to say, the controller may cause equipment used during fabrication activities 9 to be adjusted, so that the assembly activities are performed in a manner that is projected to produce another printed circuit board 16 with more desirable inspection results.
[0048] [0048]FIG. 7 shows a flow diagram that illustrates the steps just described. In particular, in step 100 , a conductor is formed on a substrate. At least one conductor is formed, but as many as necessary are formed during assembly activities 9 to produce the desired printed circuit board 16 . The printed circuit board 16 is provided to the inspection system 10 . In step 110 , the printed circuit board 16 is inspected to determine the cross-section information (i.e., the surface dimension and the footprint dimension, and any other cross-section information that may be desired).
[0049] The report 46 is produced, containing cross-section information, and provided to the controller 1 in step 120 . In step 130 , the controller determines whether the cross-section information is acceptable. That is to say, the controller determines whether the cross-section information indicates a problem that needs correction, or does not indicate such a problem. If there is a problem that needs correction, processing continues from step 130 to step 140 , in which the controller adjusts the assembly activities based on the cross-section information prior to resuming production at step 100 . If there is not a problem that needs correction, processing may continue from step 130 to step 100 , and production may continue as before.
[0050] [0050]FIG. 8 shows another method of manufacturing electrical circuits, and is similar in many ways to the method illustrated in FIG. 6 except that the report 46 provided by the inspection system 10 is used to determine whether to undertake repair activities, to discard the printed circuit board, or to approve the printed circuit board. It will be appreciated that in this mode of operation, inspection system 10 typically provides an inspection report 47 containing inspection data correlated to specific locations on an inspected printed circuit board substrate 20 . This enables a decision making process that facilitates further automatic or manual inspection of defective locations, and ultimately the repair of those defective portions of the printed circuit board substrate 20 which are deemed repairable.
[0051] [0051]FIG. 9 is a flow diagram that illustrates the steps just mentioned. In particular, steps 100 - 120 are the same as mentioned above with respect to FIG. 7. In step 130 , however, if the cross-section information is acceptable, the printed circuit board 16 is approved. On the other hand, if the cross-section information is not deemed to be acceptable in step 130 , processing continues to step 230 in which it is determined whether repair can or cannot be performed. If it is determined that repair can be performed, then processing continues with the printed circuit board 16 being repaired in the step indicated as “repair conductor”. If it is determined that repair cannot be performed, then the printed circuit board 16 is discarded.
[0052] Another way of saying this, is that the circuit is discarded or repaired in response to a determination based on the cross sectional information.
[0053] It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art. | Surface dimension and footprint dimension values are determined by scanning a printed circuit board with a laser. Exposed substrate parts of the printed circuit board fluoresce significantly, emitting detectable luminance, while conductors do not. Conductors reflect the laser light much more strongly than the exposed substrate, especially at the substantially flat part of the top surface. Luminescence and reflectivity collectors provide signals indicative of the footprint and surface dimensions. This cross-sectional information is used in making adjustment determinations in the manufacturing process, and also decisions relating to repair or discard operations. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a mounting device for a continuous rope light intended to extend over an interior corner of a structure. The mount would be part of a system for mounting a continuous or a contiguous series of rope lights onto a plurality of topological surfaces such as a building exterior.
BACKGROUND
[0002] The external ornamentation of a structure such as a house or a building is well known in the industry especially for the purposes of holiday lighting and/or advertising indicia. Initially strings of incandescent lights were used that required no more than simple hooks to mount them to a structure. The next evolution of exterior structure lighting employed series of light emitting diodes (LEDs) and their supporting electrical conductors enveloped within a flexible, translucent plastic tube which were to become known as a rope lights. These early rope lights were produced in lengths limited to the manufacturing limitations of the external tube and the process for drawing the LED arrays into the tube.
[0003] The current state of the art in rope lights utilizes LEDs and their conductors extruded within a continuous medium of flexible, translucent plastic. Enveloping the lights and conductors within the plastic medium guaranteed efficient orientation of the LEDs for best light output and protected the lights and conductors from the effects of weather. This extruded configuration increased the practical length of the rope light greatly as the power utilization of the LEDs became the new limiting factor. Since the nature of LEDs is power efficiency, the maximum length of the rope light has increased dramatically. A new limiting factor introduced with the extruded rope light is the amount the rope light can bend before stressing or breaking the internal components in the extrusion.
[0004] When mounting a rope light to a structure it is advantageous to have as few breaks between continuous lengths of rope lights to minimize the possibility of breaks and exposure of the rope light circuitry. Systems of mounting modules have been created to conform a rope light to the external topography of structures but when encountering a significant angular redirection most systems require a junction module that necessitates a break in the rope light. This is most obvious when it comes to interior corners as most mounting systems are designed to be in direct contact with the surface of the structure.
[0005] Therefore what is needed is a mounting device that would function as module in a structural rope light mounting system, for a continuous rope light that can extend over an interior corner of a pair of adjoining surfaces without requiring a break in the rope light. The device should; aesthetically match with the other modules in the system, retain the rope light at a flexure curve that will not stress the rope light's internal components, be easily installable and able to be efficiently mass produced.
SUMMARY OF THE INVENTION
[0006] To meet these needs, the present invention generally provides a mounting module for a continuous rope light that is compatible with other mounting modules configured in a structural rope light system. The rope light mounting module is designed to attach to a structure in an interior corner without interrupting the rope light by a break in the extrusion or integrated electrical conductors. The module would hold the rope light at a flexure curve that assures an amount of stress non-detrimental to the internal conductors, light emitting diodes or other integrated components of the rope light.
[0007] In one aspect of the invention, the rope light mounting module would include structural elements such as holes, slots or indents for fixing the mounting module to the structure with fasteners such as screws, nails, staples or the like. The structural elements may be placed in a location where the fasteners would be occluded by the installation of the rope light.
[0008] In another aspect of the invention, the rope light mounting module would include connection elements such as a set of mated extensions and cavities to connect the ends of the interior corner module to other modules of the rope light mounting system. The connection elements would connect to each other in a seemingly seamless manner to enhance the aesthetic flow of the system.
[0009] In another aspect of the invention, a rope light mounting module is manufactured as a two piece construct with each of the two pieces being identical to each other. Such a design configuration would allow ease of manufacturing, assembly and parts maintenance.
[0010] A significant benefit provided by the present invention is that the interior corner mount would allow the mounting of a continuous rope light across an interior corner without the need of interruption to the rope light itself. Other advantages include an uninterrupted aesthetic to the rope light mounting system, ease of installation and efficiency of manufacture.
[0011] Further advantages of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
[0012] The invention will be better understood and objects of the invention will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
[0013] FIG. 1 is an exterior view of a structure with an interior angle to which a rope light system is attached
[0014] FIG. 2 is an upper perspective view of one embodiment of a rope light system illustrating the invention combined with other elements of the system.
[0015] FIG. 3 is an exploded view of FIG. 2 showing the constituent elements of this embodiment of a rope light system.
[0016] FIG. 4 is an enlarged perspective view of one embodiment of an interior corner mount module.
[0017] FIG. 5 is an enlarged perspective view of another embodiment of an interior corner mount module utilizing twin sections.
[0018] FIG. 6 is an enlarged perspective view of one twin section of the interior corner mount module of FIG. 5 .
[0019] FIG. 7 is a plan view of a single twin section of the interior corner mount module.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in detail sufficient to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and mechanical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
[0021] FIG. 1 depicts a structure ( 2 ) or building such as a house that includes and interior corner ( 4 ) or a pair of surfaces adjoined at an acute or obtuse angle. On the edge of the roof is depicted a rope light system ( 6 ) that is mounted along an interior corner ( 4 ) section of the roof's perimeter.
[0022] FIG. 2 is a close-up view of the rope light system ( 6 ) depicted in FIG. 1 . The system is comprised of five mounting modules ( 8 ) and a rope light ( 10 ). The specific modules, listing from left to right, include; an end cap ( 14 ), a linear rail ( 12 ), an interior corner mount module ( 20 ), another linear rail ( 12 ), and another end cap ( 14 ). It is anticipated that a rope light systems ( 6 ) utilizing many more parts, such as angled junctions, exterior corner mount modules, curved rails, angled rails, multi junctions, etc. could be configured, but for the purpose of specifying the present invention the simple rope light system ( 6 ) is sufficient for example.
[0023] FIG. 3 is an exploded view of FIG. 2 demonstrating the constituent parts of the rope light system ( 6 ). The rope light ( 10 ) is retained within a channel ( 26 ) that is integral to all of the mounting modules ( 4 ). Each mounting module also includes a rail face ( 32 ) or outer decorative molding that gives the rope light system ( 6 ) a clean and continuous look. The linear rails ( 12 ) include a pair of receiving cavities ( 30 ) within the rail faces ( 32 ) at each end designed to engage a coupling extension ( 28 ) from the adjacent mounting module ( 8 ). The embodiment specific to FIG. 3 depicts that the interior corner mount module ( 20 ) consists of a pair of twin sections ( 40 ) forming a lower and upper half divided along the longitudinal axis.
[0024] FIG. 4 shows the interior corner mount module ( 20 ) as a single piece. Both ends include a pair of coupling extensions ( 28 ) extending beyond the rail faces ( 32 ) for engaging with receiving cavities ( 30 ) formed within the rail faces ( 32 ) of its complimentary mounting modules ( 8 ) but the invention is not so limited. In alternate embodiments a pair of coupling extensions ( 28 ) may only exist on a first end having a pair of receiving cavities ( 30 ) at the second end. Likewise each end may include one coupling extension ( 28 ) and one receiving cavity ( 30 ) that would compliment any end-to-end connection. The coupling extension ( 28 ) comprises any extension of the interior corner mount module ( 20 ) that would be designed to fit or nest within the receiving cavity ( 30 ) of a complimentary mounting module ( 8 ). Such coupling extensions ( 28 ) may include any shape that would adequately fit into a corresponding receiving cavity ( 30 ). The coupling extensions ( 28 ) and receiving cavities ( 30 ) may be designed to engage each other in a mechanical engagement, tension attachment or merely align the connecting modules together to form a continuous aesthetic look with no means for fixture.
[0025] The configuration of the interior corner mount module ( 20 ) includes a pair of surfaces that are designed to match the angle of the interior corner ( 4 ) of the structure ( 2 ). The first matching surface ( 22 ) would conform to a first surface of the interior corner ( 4 ) of the structure ( 2 ) and the second matching surface ( 24 ) would conform to the second surface of the interior corner ( 4 ) of the structure. In the illustration of FIG. 4 the surfaces are aligned at a ninety degree angle to one another but the invention is not so limited. It is anticipated that a variety of interior corner ( 4 ) angles, both acute and obtuse, could be matched by alternate designs of the interior corner mount module ( 20 ). FIG. 7 best illustrates the relation of the first and second matching surfaces ( 22 & 24 ) to the interior corner mount module ( 20 ). In FIG. 4 these surfaces are located generally near the ends of the interior corner mount module ( 20 ) and include the fastener accommodations ( 34 ) for attaching each end of the interior corner mount module ( 20 ) one to each of the adjoining surfaces of the interior corner ( 4 ) of the structure ( 2 ).
[0026] The embodiment illustrated in FIG. 4 includes a matched or mirrored pair of decorative rail faces ( 32 ), one to each side of the channel ( 26 ). The rail face ( 32 ) is similar to molding which forms a decorative faqade intended to blend the look of the rope light system ( 6 ) apparatus into the aesthetic look of the structure's ( 2 ) exterior. Although a matched pair of rail faces ( 32 ) are shown in the exemplary Fig.s the invention is not so limited. It is anticipated that depending on the design of the rope light ( 10 ) the top and bottom rail faces ( 32 ) may be substantially dissimilar in size, cross-sectional shape, texture and/or angle. For example, the rail faces ( 32 ) of an alternative design may resemble crown molding, consist of a simple abutment or include a texture to match a complimentary style such as a pattern copied from wall paper.
[0027] The interior corner mount module ( 20 ) includes a channel ( 26 ) designed to receive and retain a rope light ( 10 ). The channel may include continuous well and wall surfaces or as depicted in the figures consist of a series structural ribs, all with channel forming cut-outs. The rope light ( 10 ) in the illustrated embodiment has a generally rectangular cross section that is retained within the channel ( 26 ) by a pair of overlapping lips formed by the end perimeter of the rail faces ( 32 ) forming the edges of the channel ( 26 ). In other embodiments the rope light ( 10 ) may have a different cross section to which the channel ( 26 ) would conform to retain the rope light ( 10 ) in a nested fit.
[0028] The interior corner mount module ( 20 ) is curved along its length conforming to a safe amount of flexure for the rope light ( 10 ). This amount of curve is calculated to assure the integrity of the constituent functional elements within the rope light ( 10 ) which may be damaged from flexing the rope light ( 10 ) too aggressively. Illustrated in the in FIGS. 1 through 7 are modules designed for a rectangular cross section rope light ( 10 ) with specific characteristics. It is anticipated that when employing a flatter, or more robust rope light ( 10 ) that the flexure angle could be more severe or if employing a thicker, or more delicate rope light ( 10 ) the flexure angle would be less severe. The measure of the flexure angle would be dependant of the specific characteristics of the rope light ( 10 ). The advantage provided by the curvature is that by holding the rope light ( 5 ) in such a manner allows the negotiation of an interior corner ( 4 ) without the need of a junction or break in the rope light ( 10 ).
[0029] The interior corner mount module ( 20 ) includes a number of fastener accommodations ( 34 ) for attaching it to the structure ( 2 ). In FIG. 4 the fastener accommodations ( 34 ) are in the form of holes, through which a screw (not shown) would be passed through and engaged to the structure ( 2 ) until the head of the screw could bias the interior corner mount module ( 20 ) against the structure ( 2 ) in a fixed yet removable manner. Similarly the same fastener accommodation ( 34 ) may employ a nail (not shown) to fix the interior corner mount module ( 20 ) to the structure. It is anticipated that a variety of fasteners may be used to attach the interior corner mount module ( 20 ) to the structure ( 2 ) including; staples, rivets, tension bolts, expansion bolts, twist locks, clasps, hooks, and etcetera wherein the shape and structure of the fastener accommodation ( 34 ) would be readily adapted by those skilled in the art to conform to the individual characteristics of the specific fastener. When assembled the installation of the rope light ( 10 ) would occlude the fastener accommodation ( 34 ) and fastener from view.
[0030] FIG. 5 illustrates an embodiment of the interior corner mount module ( 20 ) which consists of two twin sections ( 40 ) that when connected to each other form an alternative embodiment of an interior corner mount module ( 20 ′) similar to the embodiment depicted in FIG. 4 . The twin sections ( 40 ) are identical to each other and use a number of symmetrically and complimentarily placed alignment guides ( 42 ), tension tabs ( 44 ) and catches ( 46 ) to connect to each other. The fastener accommodations ( 34 ) in the twin section ( 40 ) embodiment, take the form of complimentary detents, which, when connected together, form a hole. Similarly the tension tab ( 44 ) mounted on one side complimentarily link with the catch ( 46 ) on the opposite side to form a means for interlocking the twin sections ( 40 ) together. The catch ( 46 ) in this embodiment is merely an opening designed to engage the hook end of the tension tab ( 44 ). That same opening also allows one to displace the proximal end of the tension tab ( 44 ) to disengage it from the catch ( 46 ) for disassembly. Alignment guides ( 42 ) may include any element that helps guide the individual twin sections ( 40 ) into proper alignment for engaging one another. In FIG. 5 , one alignment guide ( 42 ) is an extension of one of the ribs forming the channel ( 26 ) which slides between and the edge of the tension tab ( 44 ) and another channel forming rib. FIG. 6 illustrates a second alignment guide ( 42 ) taking the form of an extending ridge on the back of the interior corner mount module ( 20 ) which engages with a complimentary cavity formed in the symmetrically opposite side.
[0031] FIG. 6 represents a single twin section ( 40 ) illustrating the unengaged tension tab ( 44 ) and catch ( 46 ) as well as a pair of alignment guides ( 42 ).
[0032] FIG. 7 represents a top view of one of the twin sections ( 40 ) showing the angular relation of the first matching surface ( 22 ) and the second matching surface ( 24 ) to the overall shape of the interior corner mount module ( 20 ).
[0033] It should be appreciated from the foregoing description and the many variations and options disclosed that, except when mutually exclusive, the features of the various embodiments described herein may be combined with features of other embodiments as desired while remaining within the intended scope of the disclosure.
[0034] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments and combinations of elements will be apparent to those skilled in the art upon reviewing the above description and accompanying drawings. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. | A mounting module for a rope light system which easily attaches to the surfaces of an interior corner of a structure that can retain and support a rope light without the need of a junction or brake in the rope light by holding the rope light in a flexure curve that does not stress the LEDS or electrical conductors of the rope light. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a mounting means for a panic exit device.
There are numerous types and styles of mechanisms used for operating popular commercial or public door latches, including a panic bar release arrangement, or panic exit device, mounted on the inside of the door for rapid and foolproof actuation of the mechanism, to open the door. Such arrangements are characterized by readily accessible manual actuators for use in a panic or emergency situation.
A desirable feature in an installation of this type of panic exit device is a minimum size of an active door stile containing the latching arrangement such as a bolt assembly, and a minimum size of the panic exit device. This is particularly desirable with glass doors which derive their aesthetic quality from their uncluttered look. U.S. Pat. No. 4,839,988, assigned to the assignee of the present application, discloses such a panic exit device and door stile arrangement. It is desirable to provide an exit device which may be easily and economically mounted to a door stile, particularly to this type of door stile, and enhances the aesthetic quality of the door assembly. U.S. Pat. No. 4,839,988 discloses such a device but requires a plurality of screws attaching the exit device to a middle panel area or middle rail of the door. Mounting the exit device to the door thus presents a time consuming and labor intensive operation.
U.S. Pat. No. 3,663,047, U.S. Pat. No. 3,940,886, U.S. Pat. No. 3,993,335 and U.S. Pat. No. 4,083,590 disclose panic exit devices which are attached to their respective doors by screws. In U.S. Pat. No. 3,993,335 the exit device is secured to the door by a combination of shoulder screws and set screws engageable to the shoulder screws. In all these listed patents, a screwed connection into the door or stile is required to hold the panic exit device assembly to the door.
It is therefore new to the art to provide a means of attaching a panic exit device to a door which: is economical to manufacture; provides for a quick and foolproof installation or removal of a malfunctioning panic exit device; uses a minimum of drilled and tapped screwed connections into the door or door stile; and provides a rugged construction.
SUMMARY OF THE INVENTION
The present invention relates to a means of mounting a panic exit device to a door. More particularly, the invention relates to a mounting means for mounting a panic exit device which resides recessed interior of a middle horizontal rail of the door.
Objects of the invention are to provide a means of attaching a panic exit device to a door which:
provides a simple, foolproof manner of attachment;
provides for a minimum of required loose parts, such as screws;
provides for a rapid removal and reinstallation of the panic exit device to the door;
provides a panic exit device which requires no screw holes drilled into the door for installation;
provides an aesthetically pleasing attachment with a minimum of screwed connections visible; and
provides for a relatively adjustable fit up without need for aligning screw holes thus reducing manufacturing and maintenance time. These objects are inventively achieved in that:
the panic exit device mounting arrangement requires no attachment screw holes in either the panic exit device or the door;
the panic exit device can be quickly attached or removed from the door for initial installation or maintenance purposes;
the panic exit device mounting arrangement provides a rugged and secure means of mounting such a device into a midrail of the door;
the panic exit device mounting arrangement does not require the time and precision to align screw holes in the panic exit device to screw holes in the door, as in the prior art;
the panic exit device is more easily manufactured, eliminating the machining required for threaded screw holes into the body of the panic exit device;
the panic exit device comprises a protruding actuating lever which is easily received into an opening of the active stile to engage a latching mechanism residing therein, the device is properly mounted to the active stile by inward insertion into the midrail and then lateral transport to abut the active stile, the lever inserting into the opening and engaging the latching mechanism;
the panic exit device comprises formed tabs easily insertable into notches or recesses in the door, stile and an extending portion which is captured between the door and a clamping bar, the clamping bar using two set screws to generate pressing of the extending portion between the clamping plate and the door;
the formed tabs and the extending wall portion are made integral with a back side of the mounting base of the panic exit device, thus the mounting arrangement comprises only one additional separate piece, the clamping plate with integral set screws; and
the recesses for receiving the tabs are formed integral with an opening for receiving the actuating lever of the device into the active door stile, thus the combined opening in the active stile comprises a one hole configuration, simplifying fabrication, layout and fit ups.
BRIEF DESCRIpTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of an embodiment of the invention showing the mounting relationship of the panic exit device, the inactive and active stiles, and mounting rail of the door.
FIG. 2 is a fragmentary perspective exploded view of the mounting rail of the door and mounting components of the panic exit device mounting arrangement.
FIG. 3 is a front elevation of the panic exit device mounting arrangement with panic exit device mechanical components not shown for clarity.
FIG. 4 is a sectional view along line IV--IV of FIG. 3 showing the clamping plate in an engaged condition.
FIG. 5 is a sectional view along line IV--IV of FIG. 3 showing the clamping plate in a loosened condition.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a door actuating device such as a panic exit device 10 mounted into a mid-rail 20 of a door shown generally at 24. The mid-rail 20 attaches to an active stile 30 at one end and an inactive stile 40 at another end. The term "active stile" refers to a portion of a door which houses a latching mechanism. The term "inactive stile" refers to a portion of the door holding a hinging arrangement for mounting the door 24. The active stile 30 holds bolting mechanisms therein for securing the door 24 to a door frame (not shown). The active stile 30, the mid-rail 20 and the inactive stile 40 act as a frame to hold a first panel 42 on a top end of the door 24, and act as a frame to hold a second panel 44 on a bottom end of the door 24. In the preferred embodiment, the panels 42,44 are composed of glass, however other materials may be used.
The panic exit device 10 comprises a push bar 50 engaged by a user attempting to exit the door 24. The push bar 50 is advanced inwardly toward a mounting frame or base member 60 to disengage the bolting mechanisms from the door frame. A lever 64 protrudes from the panic exit device into an opening 74 of the active stile, and engages an actuating pin 70 and accomplishes the disengagement of the bolting mechanism when the push bar 50 is activated. Such a panic exit device is more completely described in U.S. Pat. No. 4,839,988. Although the preferred embodiment of the invention relates to a panic exit device as described in U.S. Pat. No. 4,839,988, the invention could be utilized in other door actuating devices and mounting arrangements for such devices are encompassed by the invention.
FIG. 2 shows an exploded view of the active stile 30 and the mid rail 20 along with the base member 60. The base member 60 is shown in simplified form without showing the plurality of mechanical attachments required as further described in U.S. Pat. No. 4,839,988. The base member 60 provides an upstanding plate member 75 which extends at a first end in two formed tabs 76a, 76b which protrude toward the active stile 30. The plate member 75 extends at a second end in extending portion 77. The plate member 75 is formed with two flanges 78a, 78b which provide rigidity of the base 60. The flanges 78a, 78b are formed along the length of the plate member 75 but terminate at the second end, short of the extending portion 77. Thus, the extending portion 77 is a flat member without flanges. A wedging means, such as a clamping bar 80 is shown which includes two set screws 82a, 82b.
The active stile 30 comprises an opening 74 for access to the latching mechanism by the panic exit device. The opening 74 further provides two recesses 86a, 86b wherein the formed tabs 76a, 76b are inserted to mount the panic exit device 10. The recesses 86a, 86b provide side walls 86c, 86d which prevent lateral movement of the tabs 76a, 76b with respect to the recesses 86a, 86b and thus prevent outward extraction of the base 60 from the midrail 20, at the first end.
The midrail 20 is shown comprising a generally C-shaped cross section with a backwall or upstanding leg 88 and two flange portions 90a, 90b. Flange portions 90a, 90b further provide inwardly projecting rails 92a, 92b arranged parallel to the upstanding leg 88. In the preferred embodiment the rails 92a, 92b substantially span the length of the midrail 20 but this is for aesthetic reasons and to add some structural rigidity. A pair of tabs or short rails could be used instead to abut the clamping plate 80 as described below.
FIG. 3 shows the base member 60 installed into the midrail 20 with the formed tabs 76a, 76b inserted into recesses 86a, 86b. The clamping bar 80 is in position pressing extending portion 77 and plate member 75 against upstanding leg 88 of the midrail 20.
FIG. 4 shows the base 60 mounted and secured into the midrail 20. The clamping bar 80 is pressed against rails 92a, 92b by inward extension of the set screws 82a, 82b against the extending portion 77 of the plate member 75. Inward extension of the set screws 82a, 82b presses the extending portion 77 against the upstanding leg 88 and creates an opposing pressing force of the clamping bar 80 to the rails 92a, 92b. Thus, the base member 60 is prohibited from outward extraction from the midrail 20 by interference of the clamping bar 80 with the rails 92a, 92b and the base member 60 is prohibited from lateral sliding movement along the midrail 20 by a frictional attachment of the plate 75 against the upstanding leg 88 caused by tightly pressing the extending portion 77 and the plate member 75 onto the upstanding leg 88. The rails 92a, 92b could be configured as tabs or short rails to abut the clamping bar 80 and any such abutting member attached to the midrail 20 is encompassed by the present invention.
The mounting base 60 is shown with flange 78b resting on the rail 92b for support.
FIG. 5 shows the base 60 in a condition preceding removal (or alternatively in an uncompleted stage of installation). The clamping bar 80 is in a loosened configuration with respect to the extending portion 77. The set screws 82a, 82b have been disengaged from the extending portion 77 and the clamping bar 80 is now in a position to be maneuvered away from the extending portion 77 and outwardly of the rails 92a, 92b. The base 60 can be slid away from the active stile 30 to disengage the lever 64. The panic exit device can then be removed outwardly of the midrail 20.
Installation of the panic exit device 10 is thus a simple process. The device 10 is inserted inwardly of the midrail 20 and slid toward the active stile 30. The lever 64 engages the pin 70 and the tabs 76a, 76b, are received by the recesses 86a, 86b. The clamping bar 80 is maneuvered between the extending portion 77 and the rails 92a, 92b. The set screws 82a, 82b are extended inwardly of the device 10 against the extending portion 77 which presses the extending portion 77 against the upstanding leg 88. The panic exit device 10 is thus mounted inside the midrail 20.
Although other modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art. | A mounting arrangement for mounting a panic exit device to a midrail of a door provides for a foolproof and quick attachment of the device to the door. The invention includes only two formed tabs insertable into matching recesses in the active stile of the door, and a clamping bar with two set screws holding a remote end of the device to the midrail of the door. The arrangement requires a minimum of machining, eliminating the need to match screw holes between the midrail of the door and the panic exit device, and reduces required precision in mounting such a device to a door midrail. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a U.S. national stage of International Application No. PCT/EP2009/057749, filed on 23 Jun. 2009. This patent application claims the priority of Austrian patent application A1486/2008 filed 24 Sep. 2008, the content of which application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to current regulators and, more particularly, to a current regulating system comprising at least one series branch containing a linear series regulator for forming a manipulated variable signal, where a series regulator is connected to a semiconductor control element, which is connected to a supply voltage referred to ground, and an output voltage referenced to ground at the series regulator on the output side. The invention also relates to a method for regulating a current.
[0004] 2. Description of the Invention There are numerous electrical and electronic applications that make current regulation necessary. For example, power supplies are known that regulate the current to output a constant current to one or more connected loads.
[0005] In addition, electronic protective devices are known that are used to safeguard one or more load circuits connected to a power supply. If a fault (e.g., a short-circuit) occurs in a load circuit, the electronic protective device limits the current for a short time (e.g., a few milliseconds) by current regulation and then turns off. The other load circuits continue to be supplied from the power supply. Also when momentary excess currents occur, for instance, when a load is switched on, electronic protective devices limit the current to a defined value.
[0006] In such applications, which only provide current limiting or current regulation for a short time, simple linear series regulators are mostly used. Such series regulators control a semiconductor control element, which absorbs energy for a short period to keep the current through a connected, faulty load at a defined value. The schematic layout of a corresponding current regulating system is shown in FIG. 1 . In this circuit, a series branch for regulating a current through a connected load is provided at a supply voltage.
[0007] A reference value or setpoint value for regulating the current, and a current measurement value are referenced to the output voltage, which drops across the connected load. The series regulator is supplied here from an auxiliary voltage, which likewise has the output voltage as the reference potential. The auxiliary voltage is used to generate a sufficiently high manipulated variable signal between a control terminal (gate) and an output terminal (source) of the semiconductor control element.
[0008] If, for example, a plurality of series branches are connected in parallel to a supply voltage, a separate auxiliary voltage must be provided for each series regulator because each auxiliary voltage generally has a different output voltage as the reference potential.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the invention to provide an improved current regulating system and a correspondingly improved method for current regulation.
[0010] These and other objects and advantages are achieved in accordance with the invention by a current regulating system and method in which a reference signal is supplied to a series regulator, a current measurement signal and the manipulated variable signal are referenced to ground, where the manipulated variable signal is supplied to a subtractor, which sums the output voltage and the manipulated variable signal and subtracts the supply voltage, and where the output signal from the subtractor that is formed in this manner is supplied to a semiconductor control element as a corrected manipulated variable signal. The current regulating system is thereby prevented from starting oscillation caused by impedances in the control path. The frequency of such an oscillation would lie above the cut-off frequency of the series regulator. The manipulated variable signal is corrected almost immediately by the subtractor because of a simple calculation operation. As a result, the corrected manipulated variable signal to control the semiconductor control element prevents oscillation of the control path because the voltage between the control terminal and the output terminal of the semiconductor control element is substantially unchanged until the series regulator defines a changed manipulated variable signal.
[0011] In an embodiment, the series regulator is connected to an auxiliary voltage which is referenced to ground. Here, it is advantageous if the auxiliary voltage is present at an auxiliary supply that is arranged in series with the supply voltage. The supply voltage is thereby also used to supply the series regulator to achieve a higher level than the supply voltage for the manipulated variable signal. This higher level is required for controlling the semiconductor control element.
[0012] In another embodiment, a current amplifier is advantageously provided to form the current measurement signal, where the current amplifier is connected to the auxiliary voltage and is connected to measurement points before and after a shunt resistor that is connected in series with the semiconductor control element. A shunt resistor creates a simple facility for making an accurate and highly responsive current measurement that is unaffected by external factors such as an ambient temperature.
[0013] The semiconductor control element changes its forward resistance as a function of the manipulated variable signal applied to the control terminal. Here, it is advantageous to use simple components, such as common bipolar transistors, field effect transistors (e.g. MOSFETs) or insulated gate bipolar transistors (IGBTs).
[0014] In a particularly advantageous embodiment, a plurality of series branches are provided that are connected to a supply voltage and have a common auxiliary voltage for supplying the respective series regulators. The fact that the current measurement signals and reference signals are referenced in common to ground obviates the need to supply each series regulator with a separate auxiliary voltage.
[0015] A method in accordance with the invention for regulating a current provides for a series regulator to be supplied with a current measurement signal and a reference signal, and a manipulated variable is formed as a function of the difference between these two signals, where the current to be regulated is controlled by a resistance change of a semiconductor control element arranged between a supply voltage and an output voltage. In addition, the reference signal and the current measurement signal are referenced to ground, and the manipulated variable is corrected by a subtractor so that the difference of the supply voltage minus the output voltage is subtracted from the manipulated variable.
[0016] Here, the corrected manipulated variable is formed almost immediately, thereby maintaining the stability of the control circuit even with a rapid change in the output voltage or supply voltage if, as a result of the current measurement signal and the reference signal being referenced to ground, positive feedback from a line impedance occurs in the series branch.
[0017] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention is described below by way of example with reference to the attached figures, in which:
[0019] FIG. 1 is a schematic block diagram showing a current regulating system having a series regulator in accordance with the prior art;
[0020] FIG. 2 is a schematic diagram showing a current regulating system having manipulated variable correction in accordance with an embodiment of the invention;
[0021] FIG. 3 is a schematic diagram showing a current regulating system having two series branches in accordance with an embodiment of the invention; and
[0022] FIG. 4 is a flow chart of the method in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] In the conventional current regulating system shown in FIG. 1 , a direct current source DC is provided, which is connected by one terminal to ground, and at the other terminal is a supply voltage U in . A capacitor Cin for voltage smoothing is arranged in parallel with the direct current source.
[0024] A semiconductor control element 2 is connected to the supply voltage U in , the line between the direct current source DC and the semiconductor control element 2 having an impedance Z L . The semiconductor control element 2 , for example, comprises an enhancement-mode n-channel MOSFET having a gate terminal G, a drain terminal D and a source terminal S. Here, the source terminal S is connected to the drain terminal D by a parasitic diode. Moreover, the drain terminal is connected to the supply voltage U in .
[0025] A manipulated variable signal from a linear regulator 1 is present at the gate terminal G. The source terminal S is connected to an output, at which an output voltage U out exists and to which is connected a terminal of a load 4 . A second terminal of the load 4 is connected to the ground. A shunt resistor R Sh for current measurement is arranged between the source terminal S and the output.
[0026] Before and after the shunt resistor R Sh , contact points are connected to the inputs of a current amplifier 3 . The current amplifier 3 outputs a current measurement signal, which is supplied to the series regulator 1 .
[0027] The current amplifier 3 and the series regulator 1 are supplied by an auxiliary supply U H , which is referenced to the output voltage U out .
[0028] The linear regulator 1 is additionally supplied with a reference signal for defining a current setpoint value I soll , where the reference signal is likewise referenced to the output voltage U out .
[0029] The semiconductor switching element 2 is normally conducting in fault-free operation, and therefore the output voltage U out equals approximately the supply voltage U in , assuming negligible component losses and line losses. In this state, the manipulated variable signal lies below the threshold voltage of the semiconductor switching element 2 .
[0030] If, as a result of a fault, the current rises above the defined current setpoint value I soll , the regulator will start to operate. The manipulated variable signal rises above the threshold value of the semiconductor switching element 2 , and therefore the forward resistance from the drain terminal to the source terminal of the semiconductor switching element 2 increases. It is self-evident that the maximum time that such current limiting is allowed to last depends on the surrounding thermal circumstances. Usually, it is possible to regulate a current to a defined setpoint value in this way for several seconds before the semiconductor switching element 2 suffers any damage.
[0031] In order to supply, for example, a plurality of series branches arranged in parallel by an auxiliary voltage, it is desirable that the auxiliary voltage and the individual reference signals and current measurement signals are referenced to a common ground. Although this achieves the desired independence from the output voltages of the individual series branches, which are generally of different value, a change in the output voltage in a series branch will cause positive feedback in the control loop because of the line impedance Z L .
[0032] If, for instance, when there is a step-change in load, the output voltage or the voltage at the source terminal of the corresponding semiconductor component falls, this necessarily causes the voltage between the gate terminal and the source terminal to rise, because the control-value signal referenced to ground does not fall synchronously with the output voltage as a result of the line impedance Z L . This positive feedback results in an unstable control circuit and causes permanent current oscillation.
[0033] In accordance with an embodiment of the invention, a manipulated variable correction is performed to eliminate the effect of the positive feedback in the control circuit. A suitable arrangement is shown in FIG. 2 .
[0034] The basic circuit comprises a series circuit, where a load 4 is connected to a supply voltage U in by an auxiliary switch element 2 . The circuit is closed by a ground that is the common reference potential for the supply voltage U in and the output voltage U out that is dropped across the load 4 .
[0035] The auxiliary switch element 2 comprises a MOSFET, for example, as shown in FIG. 1 , where the drain terminal D is connected to the supply voltage U in and the source terminal S is connected to the output, at which the output voltage U out exists. A shunt resistor R Sh is arranged here between the source terminal S and the output. The contact points before and after the shunt resistor are connected to the inputs of a current amplifier 3 . The current amplifier 3 , which is connected to the ground, is supplied with an auxiliary voltage, which exists at an auxiliary supply U H that is arranged in series with the supply voltage. Hence, the current measurement signal at the output of the current amplifier 3 , similarly to the auxiliary voltage, is referenced to ground as is the common reference potential of the supply voltage U in and the common reference potential of the output voltage drop U out across the load 4 .
[0036] The current measurement signal and a reference signal are input to a series regulator 1 , which is supplied, similarly to the current amplifier 3 , by the auxiliary voltage. The reference signal is referenced, much like the current measurement signal, to ground, and defines the current setpoint value I soll . Therefore, at the output of the series regulator 1 there exists a manipulated variable signal u, which is referenced to ground and is supplied to a subtractor 5 . The subtractor 5 is also connected to the supply voltage U in and to the output voltage U out , and generates a corrected manipulated variable signal u′ in accordance with the following relationship:
[0000] u′=u− ( U in −U out )
[0037] In accordance with the invention, this corrected manipulated variable signal u′ is applied to the gate terminal G of the semiconductor control element 2 .
[0038] The subtractor 5 is advantageously configured as a simple analog circuit, so that the manipulated variable signal u is corrected almost immediately, i.e., as soon as a change occurs in the output voltage U out or in the supply voltage U in . In any event, the correction is performed many times faster than an adjustment of the manipulated variable signal u by the series regulator 1 .
[0039] The positive feedback from the impedance Z L is thus avoided by the immediate correction of the manipulated variable signal u. This correction equals the difference, caused by the impedance Z L , of the supply voltage D in minus the output voltage U out , whereby the voltage between the gate terminal and the source terminal of the semiconductor control element 2 is substantially unchanged until the series regulator 1 defines a changed manipulated variable signal u. The control circuit is hence stable and no current oscillation occurs.
[0040] FIG. 3 is a schematic block diagram of two series branches having different output voltages U 1out , U 2out . The series circuits are supplied by a common supply voltage D in , which is connected in series with an auxiliary voltage U H . Each series circuit comprises a separate semiconductor control element 2 1 and 2 2 respectively, which limits the current to a respective defined current setpoint value I 1soll and I 2soll in the event of a short-circuit of the load 4 1 or 4 2 connected to the respective circuit or in the event of a brief overload. Each series branch comprises a separate respective shunt resistor R 1Sh and R 2Sh for the purpose of current measurement.
[0041] Each semiconductor control element 2 1 and 2 2 is controlled by a respective corrected manipulated variable signal u 1 ′ and u 2 ′ which exists at the output of a respective subtractor 5 1 or 5 2 . The respective subtractor 5 1 or 5 2 corrects the respective manipulated variable signal u 1 and u 2 that is defined by a respective series regulator 1 1 or 1 2 according to the respective impedance Z 1L or Z 2L that arises in the series branch.
[0042] Due to all the current measurement signals, reference signals and manipulated variable signals u 1 , u 2 being referenced to a common ground, given a plurality of series branches connected in parallel, there is now only a single auxiliary voltage required, to which all the series regulators 1 1 , 1 2 and current amplifiers 3 1 , 3 2 are connected. Here, it is self-evident that more than the two series branches shown in FIG. 3 can be connected in parallel in this manner.
[0043] FIG. 4 is a flow chart of a method for regulating a current. The method comprises supplying a linear series regulator with a current measurement signal and a reference signal, as indicated in step 410 . Here, the reference signal and the current measurement signal are referenced to ground. A manipulated variable is formed as a function of a difference between the current measurement signal and the reference signal, as indicated in step 420 . The manipulated variable is corrected using a subtractor to subtract a difference of the supply voltage minus the output voltage from the manipulated variable to form a corrected manipulated variable, as indicated in step 430 . A current to be regulated is controlled by a resistance change of a semiconductor control element arranged between a supply voltage and an output voltage based on the corrected manipulated variable, as indicated in step 440 .
[0044] Thus, while there are shown, described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the illustrated apparatus, and in its operation, may be made by those skilled in the art without departing from the spirit of the invention. Moreover, it should be recognized that structures shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. | A current control system comprising at least one series arm including a linear series regulator for generating a manipulated variable signal, wherein the linear series regulator is connected to a semiconductor control element which is connected to a supply voltage referenced to a ground potential, and the semiconductor control element includes an output voltage at its output side relative to the ground potential. A reference signal fed to the series regulator, a current measurement signal, and the manipulated variable signal are referenced to the ground potential, where the manipulated variable signal is fed to a subtractor which subtracts the difference of the feed voltage minus the output voltage from the manipulated variable signal, and the generated output signal of the subtractor is fed to the semiconductor control element as a corrected manipulated variable signal. | 8 |
This Application is a continuation-in-part of U.S. patent application Ser. No. 08/731,349, filed Oct. 11, 1996 , now U.S. Pat. No. 5,852,303 and entitled "Thin Film Amorphous Matrices having Dispersed Cesium and Method of Making".
FIELD OF THE INVENTION
This invention relates to cold cathode electron emitters and, more particularly, to an improved cold cathode electron emitter which exhibits a low surface work function and a display structure employing the improved cold cathode electron emitter.
BACKGROUND OF THE INVENTION
Cold cathode electron emitters are known in the prior art and generally comprise an electron emission structure that is spaced apart from a target. A potential is applied between the electron emission structure and the target which is sufficient to cause electron migration from the electron emission structure to the target. Successful cold cathode electron emitters are required to exhibit a low surface work function so as to avoid the necessity of excessively high applied voltages. Surface work function is the energy required to remove electrons from the surface of a material. Hot cathode electron emitters overcome an electron emission structure's surface work function by applying high levels of heat to provide the energy required to stimulate the electron emission.
In general, an electron emission structure is configured with a sharp tip so that the electric field present thereat is highly intense and thus able to overcome the emitter's surface work function. The electric field at a sharp tip is inversely proportional to the radius of the tip, thus a small applied voltage and a very small radius tip (approximately 1-10 manometers) provides a very strong electric field which enables the emission of electrons by the field emission mechanism.
Cold cathode electron emitters have been fabricated using thin-film techniques. Spindt et al. in "Physical Properties of Thin-film Field Emission Cathodes with Molybdenum Cones", Journal of Applied Physics, Volume 47, No. 12, December 1976, pages 5248-5263, describe a field emission cathode which utilizes a molybdenum emitter. Spindt et al. produce such emitters, using micro-lithography techniques, in arrays of molybdenum cones and have demonstrated the availability of currents in the range of 50-150 microamperes per cone.
Kumar et al. in "Diamond-based Field Emission Flat Panel Displays", Solid State Technology, May 1995, pages 71-74, describe a display structure which employs a cold cathode electron emitter. The emission substrate is a dense, nano-crystalline carbon film, with a large percentage of the available carbon exhibiting sp 3 "diamond"-bonded carbon while the remaining material is in the form of sp 2 graphitic carbon. Further details of other field emission displays can be found in "Europe's FPD Development Offers a Chance to Compete", Dance, B., Semiconductor International, July 1995, pages 229-232.
One of the major technical obstacles to the commercialization of field emission displays involves the reliability of the cold cathode electron emission arrays. The lack of reliability originates from the high fields required for emission at room temperature. Over time, these fields (through sputtering or sputtering contamination) damage the sharp emitter tips and thus decrease their electron emission efficiency. For this reason diamond-coated tips have been proposed as cold cathode electron emission structures because diamond, simultaneously provides both mechanical strength and relatively low field operation. Prototypes employing such diamond emitters, however, still suffer from high turn-on voltages, high cost and short working life.
A common feature of many prior art field emission displays is a requirement to switch relatively large voltages on a plurality of address lines. Such switching actions create large voltage excursions which causes noise and other interference affects during the operation of the display. Nevertheless, it has been thought to be a requirement to switch such high voltages, to achieve selective electron emission from the cold cathode emission sources.
Accordingly, it is an object of this invention to provide an improved cold cathode electron emission source which exhibits a lowered surface work function.
It is another object of this invention to provide a method for the manufacture of an improved cold cathode electron emission source which exhibits a lowered surface work function.
It is still another object of this invention to provide an improved cold cathode electron emission source which exhibits an improved electron beam pattern.
It is yet another object of this invention to provide a cold cathode electron emission structure which avoids the need for switching high voltages to achieve display cell activation.
SUMMARY OF THE INVENTION
A cold cathode electron emission structure includes an amorphous carbon matrix having cesium dispersed therein, with the cesium present in substantially non-crystalline form. A cesium-carbon-oxide layer is positioned on the amorphous carbon matrix, constitutes an electron emission surface and causes the cold cathode electron emission structure to exhibit a lowered surface work function. A display structure including the aforedescribed cold cathode electron emission structure further includes a target electrode including a phosphor and exhibiting a target potential for attraction of electrons. A gate electrode is positioned between the electron emission structure and the target electrode and is biased at a gate potential which attracts electrons, but which is insufficient, in combination with the target potential, to cause emission of a beam of electrons from the electron emission structure. A control electrode is coupled to the electron emission structure and selectively applies a low-voltage control potential which, in combination with the gate potential and the target voltage, is sufficient to cause the electron emission structure to emit a beam of electrons towards the target electrode. The cesium-carbon-oxide layer in combination with the control electrode further enables the achievement of a long focal length, field effect display structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is flow diagram illustrating the process used to create a cold cathode electron emission structure in accordance with the invention hereof.
FIG. 2 is a plot of surface work function versus post-annealing temperature for plural different films: (a) Cs on Si<100>, (b) CsC on Si<100>, and (c) oxygen treated CsC on Si<100>.
FIG. 2(a) illustrates the experimental setup used to measure work function.
FIG. 2(b) is a plot of (normalized photosignal) 1/2 versus work function for a sample photoemission measurement.
FIG. 3 is a sectional view of a cold cathode electron emission structure/display apparatus incorporating the invention.
FIG. 4 is a schematic circuit diagram showing the interconnections used with the structure of FIG. 3.
FIG. 5 is a diagram illustrating the configuration of an electron beam created by the structure of FIG. 3.
FIG. 6 illustrates a further embodiment of a cold cathode electron emission structure, incorporating the invention, which provides a more focused electron beam.
FIG. 7 is a diagram illustrating the configuration of the electron beam produced by the structure of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
Prior to describing the details of the invention, a brief resume of the electron emission structure and method disclosed in co-pending U.S. patent application Ser. No. 08/731,349 will be provided. The disclosure thereof is incorporated herein by reference. The electron emission structure described in the aforementioned application comprises an amorphous matrix of a base material, such as carbon, into which cesium has been dispersed. The matrix is formed on a substrate of the type commonly used in thin film depositions, such as molybdenum, silicon, glass, titanium dioxide, etc. The preferred carbon amorphous matrix exhibits a high sp 3 /sp 2 bond ratio. The cesium, preferably in ion form, is dispersed throughout the amorphous matrix. The carbon base material is largely in tetrahedrally bonded (sp 3 ) form. The cesium, rather than occupying the place of carbon in the matrix, is found between the matrix interstices.
The amorphous matrix can include dopants to increase the conductivity of the material. The combination of the cesium, dopant and carbon matrix make the resulting material amenable as a cold cathode electron emitter. Either N- or P-type dopants can be used and may be added by either co-implantation or a subsequent implantation after the formation of the amorphous matrix.
When the high sp 3 ratio amorphous diamond matrix is grown with cesium incorporated therein, the matrix becomes conductive. The incorporation of the cesium and (cesium compounds) into the bulk of the matrix reduces the matrix work function for electron emission. Electron emitting structures produced in accordance with the described process (and as further described in co-pending application Ser. No. 08/731,349) have evidenced a work function as low as 1.1 eV.
It has newly been determined that creation of an cesium-carbon-oxide surface on the amorphous matrix of carbon and cesium described above enables a lowering of the work function from 1.1 eV to 1.05 eV. Further, it has been determined that the work function characteristic of the resulting structure is stable up to 750° C. As is known, the lower the work function of an electron emission material, the lower the applied voltage that is required to enable the emission action to occur. This fact lessens the required applied voltage and reduces any sputtering effects that may be present.
Turning to FIG. 1, the process initially commences with a co-deposition (preferably) of cesium, a dopant and carbon to create an amorphous diamond matrix with cesium and dopant inclusions (box 10). Thereafter, the surface of the matrix, except that which is to serve as an electron emission region, is masked (box 11). Next, a cesium layer is deposited onto the emission surface with a deposition energy level of about 25 eV or less. Such deposition may be accomplished through use of a cesium ion beam or a cesium vapor (box 12). The deposited cesium layer is very thin (approximately 5 atomic layers) and serves to enable the creation of a subsequent cesium-carbon-oxide on (and into) the amorphous carbon/cesium matrix. Without the presence of the cesium layer, the chemical inertness of the carbon sp 3 rich bonding does not allow the formation of an oxide overlayer.
After deposition of the cesium layer, oxygen gas is flowed over the emitting surface at a temperature in the range of 250° C.-500° C. (box 13). This action enables the formation of a cesium-carbon-oxide layer, both on and into the emission surface. The cesium layer enhances the oxidation process and enables an oxide formation which extends into the uppermost surface layers of the emitting surface.
It has been determined that a relatively high cesium content source (i,e,. a cesium neutral flux greater than 10 13 Atoms/cm 2 sec) is necessary for the formation of a stable surface oxide layer. Films made with lower cesium flux levels (less than 10 12 Atoms/centimeter 2 sec) did not form an oxide overlayer due to the chemical inertness of the sp 3 rich bonding.
Referring to FIG. 2, a plot of work function versus post-annealing temperature is plotted for different films. The work function is measured after annealing and at each data point temperature. Plot (a) shows that a cesium on silicon<100> substrate commences with a work function of approximately 1.8 eV which then increases exponentially in a post-anneal temperature range of 200-250° C. This is due to evaporation of cesium (as it is not stably incorporated in the film). Plot (b) shows the change in work function of an amorphous matrix including cesium which has been deposited on a silicon substrate. With no anneal action, a work function of 1.1 eV is present which increases as the anneal temperature rises to 200°, eventually reaching approximately 1.2 after a 750° C. anneal. Plot (c) shows change in work function for an amorphous matrix of carbon with cesium, which has been subjected to the above-indicated oxidation treatment (where the substrate is silicon<100>. A work function of approximately 1.05 eV was determined. The cesium content of the amorphous film, made in accordance with the invention, was highly stable even after a 750° C. anneal. It is believed that the cesium stability results from the capping effect of the oxide overlayer. Thus, the oxidation treated surface shows high thermal stability, which establishes a capacity to withstand further post-deposition processing (e.g., a vacuum bake-out and sealing).
FIG. 2a illustrates the experimental arrangement for the measurements of work function that are plotted in FIG. 2. A tunable, monochromatic light source 14 was used and its wavelength output was precisely controlled using two gratings (not shown), one at 1200 lines/mm and another at 600 lines/mm. The 1200 lines/mm grating was used for the shorter wavelengths (250-850 nm) calibration and the 600 lines/mm grating was used for the longer wavelengths (850-1200 nm). A long wavelength-pass filter 15 was also used to eliminate second order dispersion of the gratings. A chopper 16, operating at 400-500 Hz, interrupted the light beam and further provided a reference signal to a lock-in amplifier 17. The interrupted beam was focused by lens 18 onto a target device 19. The photosignal from target device 19 was monitored by lock-in amplifier 17 by varying the wavelength of the incident light until the photosignal value was close to the background noise. The background noise from the obtained raw data was subtracted to obtain the pure photosignal. The resulting signals at different wavelengths were normalized by dividing by the spectral density value of the light source. The square root of the normalized photosignal was plotted versus photon energy as a least squares fit to a straight line. A plot of the straight line is shown in FIG. 2b and is a sample photo emission measurement which indicates that the work function can be estimated by reading an intercept value on the photon energy axis.
The measurements were obtained as follows. The surface of the target device was cleaned by cesium ion sputtering, annealed and then exposed to a dose of 25 eV cesium ions at room temperature. The target device was then moved to the work function station and the work function was measured. All work function measurements were taken after cooling of the target device to room temperature. The cesium dose was measured by integrating the current to the target device (i.e., a silicon substrate).
While there are many applications for cold cathode electron emission sources, one of the more widely used applications is in the field of flat panel displays. As is known, such displays employ orthogonal matrices of electrodes, with cold cathode emission structures positioned at the electrode intersections. Further, each emission site includes a gate structure positioned between the cold cathode emitter and an anode electrode which includes a phosphor. Because gate voltages on the order of 50-80 volts have been required to be switched in order to achieve picture element selection, substantial voltage transients are present during the operation of such a display panel. Such transients not only produce both inter-electrode noise and but also radiation effects.
Referring to FIG. 3, a single picture element (pixel) structure in a field emission display is illustrated which overcomes the problem of such voltage transients. Field emission pixel structure 20 is positioned between a pair of support plates 22 and 24. Plate 22 is preferably glass or a transparent plastic and has deposited thereon a phosphor layer 26 and an anode electrode 28. Anode electrode 28 is, preferably, comprised of a transparent conductor material such as indium-tin-oxide. An anode potential Va is applied to anode electrode 28 via conductor 30.
Bottom substrate 24 may be any of a number of materials, but is preferably glass on which a conductive layer 32 is positioned. Conductive layer 32 is preferably grounded and supports a cold cathode electron emission material such as has been described above. In brief, it is an amorphous carbon matrix with cesium and dopant inclusions (e.g. phosphorous) to render it into a conductive state. A portion of cold cathode electron emitter 34 is formed into a conical emission tip 38 which has been subjected to an oxide processing procedure as described above. As a result, oxide layer 36 covers conical emission tip 38.
A control electrode 40 is positioned in electrical contact with non-oxidized portions of the surface of cold cathode electron emitter 34. Electrodes 26 and 40 are preferably arranged in the form of orthogonally oriented row and column conductors and, together, perform a pixel element selection function. A dielectric layer 42 encompasses conical emission tip 38 and further supports a gate electrode 44. A gate bias voltage Vg is connected via conductor 46 to gate electrode 44. Preferably, both anode bias Va and gate bias Vg are fixed during the operation of pixel element 20.
Electron emission from cold cathode electron emitter 34 is controlled by a control voltage Vc applied to electrode 40 via conductor 48. Anode bias voltage Va and gate bias voltage Vg are, together, insufficient to overcome the surface work function of conical emission tip 38 and to cause emission of an electron beam therefrom. Only when control voltage Vc is selectively applied does the potential difference between conical emission tip 38 and anode electrode 28 attain a sufficient level to enable an electron beam 50 to be emitted towards anode electrode 28. This is not to say that no electrons are emitted from conical emission tip 38 prior to the application of an appropriate control voltage Vc. However, only when an appropriate level of Vc is applied to conductor 40 is a sufficient density of electrons emitted to cause a visible level of light to be emitted from phosphor 26.
Referring to FIG. 4, a circuit diagram illustrates exemplary values for anode potential Va, gate potential Vg and control voltage Vc. As is understood by those skilled in the art, the exact values of the applied voltages are dependent upon a number of factors and the aforesaid values are given for purposes of explanation only. The relative values of Va and Vg are adjusted such that the potential difference between conical emission tip 38 and anode conductor 28 is insufficient to enable the establishment of electron beam 50. Only when control voltage Vc is switched from 0 volts to -10 volts does the potential difference between conical emission tip 38 and anode 28 enable the establishment of electron beam 50. Thus, while the prior art has applied switching potentials to gate electrode 44 (thereby requiring a switching of 50 to 80 volts), by applying the switching potential to control electrode 40, while maintaining gate electrode 44 at a constant bias potential, much lower voltage swings are utilized to control a pixel element.
While not shown in the drawings, a processor is employed to enable appropriate selection of pixel element sites. Further, each pixel element site includes, preferably, three structures such as shown in FIG. 3 to enable three phosphors 26 to be utilized for full color presentations.
Turning to FIG. 5, a field plot is shown which illustrates the electron dispersion which occurs in beam 50 when a conical emission tip 38 is utilized. However, if a planar emission structure 38' is employed, such as shown in FIG. 6, a more focused beam 50 results. Planar emission structure 38' is produced by initially depositing a cesium layer on the amorphous carbon/cesium/dopant emission structure and subsequently oxidizing the emission area 38'. Further, the edges of control conductors 40 are beveled to provide a potential well. The resulting field plot is illustrated in FIG. 7 and shows the beam focusing effect which occurs as a result of the planar emissions surface, in combination with the potential well created by beveled conductors 40. The result of the use of the cold cathode emission structure shown in FIGS. 6 and 7 is to create a more precisely focused electron beam than that which results from the use of a conical emission tip.
The emission structure of FIGS. 6 and 7 is particularly useful in a long focal length, field effect display wherein the phosphor is positioned a substantial distance from the emitter (on the order of 1-10 centimeters, as contrasted to microns in short focal length field effect displays). Such a long-focal length structure enables use of phosphors that have been developed for CRT applications. Currently, field effect displays employ low voltage phosphors which are degraded by non-moving images (e.g., a tool bar or other icon). A highly focused electron beam projected over a range of centimeters enables the use of phosphors developed for use with CRT technologies.
It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. | A cold cathode electron emission structure includes an amorphous carbon matrix having cesium dispersed therein, with the cesium present in substantially non-crystalline form. A cesium-carbon-oxide layer is positioned on the amorphous carbon matrix, constitutes an electron emission surface and causes the cold cathode electron emission structure to exhibit a lowered surface work function. A display structure including the aforedescribed cold cathode electron emission structure further includes a target electrode including a phosphor and exhibiting a target potential for attraction of electrons. A gate electrode is positioned between the electron emission structure and the target electrode and is biased at a gate potential which attracts electrons, but which is insufficient, in combination with the target potential, to cause emission of a beam of electrons from the electron emission structure. A control electrode is coupled to the electron emission structure and selectively applies a low-voltage control potential which, in combination with the gate potential and the target voltage, is sufficient to cause the electron emission structure to emit a beam of electrons towards the target electrode. The cesium-carbon-oxide layer in combination with the control electrode further enables the achievement of a long focal length, field effect display structure. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of U.S. provisional Patent Application Ser. No. 60/536,946, filed Jan. 16, 2004, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention generally relate to milling within a wellbore. More particularly, the invention relates to straightening a shifted or restricted wellbore by reciprocating a flexible broach axially within the wellbore.
2. Description of the Related Art
Hydrocarbon wells typically begin by drilling a borehole from the earth's surface to a selected depth in order to intersect a formation. Steel casing lines the borehole formed in the earth during the drilling process. This creates an annular area between the casing and the borehole that is filled with cement to further support and form the wellbore. Thereafter, the borehole is drilled to a greater depth using a smaller diameter drill than the diameter of the surface casing. A liner may be suspended adjacent the lower end of the previously suspended and cemented casing. In general, the diameter, location, and function of the tubular that is placed in the wellbore determines whether it is known as casing, liner, or tubing. However, the general term tubular or tubing encompasses all of the applications.
Shifting of the wellbore caused by pressure changes in the wellbore, swelling of surrounding formations, subsidence, earth movements, and formation changes can deform, bend, partially collapse, or pinch downhole tubulars. Therefore, a cross section of downhole tubulars becomes more irregular and non-round over time. Further, the path through the wellbore may become crooked, offset, or bent at an abrupt angle due to the shifting. Bends in the wellbore and deformed tubulars that define the bore can obstruct passage through the bore of tubing, equipment, and tools used in various exploration and production operations. For example, the bend may prevent a sucker rod from functioning and cause production to cease. Even if the tool can pass through the bore, these obstructions often cause wear and damage to the tubing, equipment, and tools that pass through the obstructed bore.
Current remediation operations to correct bends in the wellbore utilize rotational mills. The rotational mills have cutting surfaces thereon that rotate along the shifted section of the wellbore to remove casing and surrounding materials, thereby reducing the severity or abruptness of the angle. The mill provides a straighter path through the wellbore and reestablishes a bore that a round tubular can pass through. A liner secures in place across the milled portion in order to complete the remediation operation.
However, there exist several problems with using rotational mills for shifted wellbore remediation. In operation, one end of a rigid mill contacts an opposite side of the casing at the shift in the wellbore and places large side loads on the mill along the area being milled. The side loads cause rigid mills to fail prematurely resulting in the expense of replacement and repeated trips downhole to complete the milling process. Further, the mill can sidetrack away from the wellbore if the mill is not kept within the portions of the wellbore on either side of the shifted area during the milling procedure. Recently, rotating mills disposed on flexible members such as cable have been used to initiate the milling process at the shifted portion of the wellbore, thereby permitting a second mill that is run in separately to complete the milling process. Milling by rotation of a flexible mill is described in detail in U.S. Pat. No. 6,155,349, which is hereby incorporated by reference in its entirety. Requiring two trips downhole to complete the milling of the shifted section of the wellbore requires additional time at an added expense. Further, the flexible member may prematurely fatigue due to the stresses caused by the rotation during the milling.
Mills are used in various other wellbore remediation and completion operations. Generally, mills may remove ledges and debris left on the inside diameter of the tubulars such as excess cement, equipment remnants, burrs on the tubular itself, or metal burrs on the inside of the casing around a milled window. Well tubulars may become plugged or coated during production from corrosion products, sediments, hydrocarbon deposits such as paraffin, and scum such as silicates, sulphates, sulphides, carbonates, calcium, and organic growth. Thus, milling operations can remove the debris that collects on the inside surface of the tubular in order to prevent obstruction of the passage of equipment and tools through the bore of the tubulars. Further, mills can be used to elongate windows and straighten the angle into a lateral wellbore.
Therefore, there exists a need for an improved tool and method of milling within a wellbore that reduces stress and fatigue from rotation. There exists a further need for an improved method for remediation of a shifted section of wellbore with a single trip downhole.
SUMMARY OF THE INVENTION
The present invention generally relates to methods and apparatus for milling and/or broaching within a wellbore. A flexible broach runs into the wellbore and is located adjacent a portion of the wellbore to be broached. The broach reciprocates axially within the wellbore and removes at least part of the portion to be broached. Weight may be coupled to the broach, thereby applying a resultant side load for broaching an offset portion of the wellbore. The broach comprises a flexible member that may be a bare cable. When an abrasive material is disposed on an outer surface of the flexible member, the flexible member may be a cable, a continuous rod, or pressurized coiled tubing. Alternatively, sleeves positioned on the flexible member may have an abrasive material on their outer surface. A rotational mill that is either coupled to the broach or run in separately from the broach can further mill the wellbore.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a sectional view of a wellbore illustrating a flexible broach reciprocating axially adjacent a shifted or bent section of the wellbore.
FIG. 2 is a view of a milling tool having a flexible broach portion coupled to a rotational mill portion.
FIG. 3 is a view of a cylinder of the flexible broach portion of the milling tool shown in FIG. 2 .
FIG. 4 is a view of the milling tool shown in FIG. 2 during a broaching operation within a wellbore.
FIG. 5 is a view of the milling tool shown in FIG. 2 during a milling operation within the wellbore.
FIG. 6 is a view of an elliptical cylinder for coupling to adjacent elliptical cylinders to form a flexible broaching tool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention generally relates to milling in a wellbore using a flexible broach. FIG. 1 illustrates a wellbore 100 having casing 102 and a flexible broach 104 positioned in the wellbore 100 adjacent a shifted or bent section of the wellbore 100 . A downhole camera (not shown) may be run in on the broach 104 or milling tool to establish proper position within the wellbore 100 prior to milling or broaching. Other known locating techniques or devices may be used for locating the broach 104 at the bent section. The broach 104 may be lowered to the bent section using any known conveyance member 108 . All of the mills and broaches described herein are run into a wellbore on a conveyance member and located therein. In certain embodiments, the broach 104 may be an integral portion of the conveyance member 108 as will be apparent for embodiments wherein the broach 104 is a cable, a continuous rod, or coiled tubing. As indicated by arrow 106 , the broach 104 reciprocates axially within the wellbore 100 to cut or broach a slot 110 in the casing and/or the surrounding formation or cement. The broach 104 may be reciprocated axially by any known method such as by axially moving the conveyance member 108 at the surface of the wellbore 100 . In this manner, elimination of rotational torque to the broach 104 prevents fatigue and failure of the broach 104 .
The broach 104 shown in FIG. 1 includes a flexible elongated body 112 and a weight 114 attached at a lower end of the elongated flexible body 112 . The weight 114 provides tension to the body 112 such that the body 112 frictionally contacts the bent section of the wellbore 100 where the slot 110 is formed. In one embodiment, the body 112 is a bare cable or wire rope that abrades or saws the slot 110 as the broach 104 reciprocates within the wellbore 100 . In an alternative embodiment, the body 112 is a cable, a portion of a continuous rod, or a portion of pressurized coiled tubing that is coated with an abrasive material 116 such as crushed tungsten carbide. The abrasive material 116 is shown spaced axially along the body 112 . However, the abrasive material 116 may be disposed along the entire length of the body 112 . The broach 104 permits cutting of the slot 110 at a high rate since the entire length of the broach 104 cuts the slot 110 using multiple blades formed by the abrasive material 116 .
With the broach 104 shown in FIG. 1 , it may be necessary to remove the broach from the wellbore 100 and further mill the slot 110 using a rotational mill (not shown) in order to open up the slot 110 to full gage. However, the slot 110 effectively reduces the angle of the bend, the amount of rotational milling required and the stress on the rotational mill. An exemplary rotational mill is illustrated by a rotational milling portion 201 of a milling tool 200 shown in FIG. 2 . However, any known rotational mill may be run into the wellbore 100 to open up the slot 110 . As explained with the milling tool 200 in FIG. 2 , the rotational mill may include a stinger section that guides the rotational mill into the slot 110 .
FIG. 2 shows a milling tool 200 having a flexible broach portion 202 coupled to a rotational mill portion 201 . The rotational mill portion 201 has a connector end such as box end 203 for connecting to a conveyance member and a stinger 205 opposite the box end 203 . Since the stinger 205 is integral with a shaft 207 of the rotational mill portion 201 , the rotational mill portion is long, preferably approximately twenty five feet. The length of the rotational mill portion 201 permits the rotational mill portion to flex, thereby aiding in relieving stress. Further, the length of the rotational mill portion 201 initially spaces the box end 203 from the sharp bend in the wellbore in order to prevent the connection at the box end 203 from breaking or failing. The stinger 205 preferably increases in outer diameter towards the box end 203 . As shown, the rotational mill portion 201 has five blade sections 204 axially spaced and located between the box end 203 and the stinger 205 . However, the rotational mill portion may include any number of blade sections 204 . Each blade section 204 has milling inserts (not shown) positioned along the blades directed to cut both down and sideways such that the rotational mill portion 201 relieves some of the side load by milling sideways as well as down.
Between the rotational mill portion 201 and the flexible broach portion 202 is a swivel 208 or knuckle joint that isolates rotational torque applied to the rotational mill portion 201 from the flexible broach portion 202 . Additionally, a cable connector such as a cable slip 209 may be used to couple a cable 212 (e.g., a left-hand wound cable) of the flexible broach portion 202 to the rotational mill portion 201 . In some embodiments, the cable 212 is fixed to a box connection or other connection in order to couple the cable 212 to the rotational mill portion 201 and does not require use of the cable slip 209 .
The flexible broach portion 202 includes the cable slipped through an internal longitudinal bore of a series of cylinders 210 coated with an abrasive such as crushed tungsten carbide. As shown in more detail in FIG. 3 , each cylinder 210 has the longitudinal bore 303 and a cutting helix 300 on an outside surface that is oriented such that the leading edge of the helix 300 is perpendicular to the area being cut. Thus, helix 300 provides a cutting surface on the cylinder 210 that is perpendicular to the area cut when the cylinder 210 reciprocates axially and not rotationally. The helixes can be offset or at alternating angles (e.g., clockwise and counter clockwise). A convex ball nose 301 of the cylinder 210 mates with a concave socket end 302 of an adjacent cylinder. The ball 301 and socket 302 mating of adjacent cylinders provides flexibility to the flexible broach portion 202 . Referring back to FIG. 2 , weights 213 are attached to the cable 212 below the cylinders 210 in order to supply tension to the flexible broach portion 202 during a broaching operation. Weights 213 and cylinders 210 may be attached together using tool joints that are babbitted to the cable ends. For example, connections such as between the cable 212 and the rotational mill portion 201 may be formed by positioning a tool joint over an end of the cable 212 , fraying the end of the cable and pouring a babbitt or epoxy resin into a socket of the tool joint as is known in the industry.
FIG. 4 shows the milling tool 200 shown in FIG. 2 during a broaching operation within a wellbore 400 . As indicated by arrow 406 , the milling tool 200 reciprocates axially to cut a slot 410 into a casing 402 at a bend in the wellbore 400 . During the broaching operation, the flexible broaching portion 202 is located adjacent the bend in the wellbore 400 . Thus, the reciprocation of the cylinders 210 having abrasive outer surfaces in contact with the casing 402 at the bend broaches the slot 410 .
FIG. 5 illustrates the milling tool 200 during a milling operation after forming the slot 410 in the casing 402 with the broaching operation. The stinger 205 enters the slot formed by the flexible broach portion 202 to guide the rotational mill portion 201 during the milling operation. Further, the stinger deflects in order to provide a side force so that the rotational mill portion 201 located adjacent the bend mills sideways to relieve its own stress. As indicated by arrow 506 , the milling tool 200 rotates to mill the wellbore 400 at the bend using the rotational mill portion 201 . The swivel 208 prevents transferring rotation to the flexible broach portion 202 . Even if rotation is transferred to the flexible broach portion 202 , the flexible broach portion 202 is not stressed during the rotation from the milling operation.
Any flexible broach 104 embodiment described in FIG. 1 may replace the flexible broach portion 202 of the milling tool 200 shown in FIG. 2 . Further, while FIGS. 2 , 4 and 5 are shown having the rotational mill portion 201 coupled to the flexible broach portion 202 , the flexible broach portion 202 may be used independently of the rotational mill portion 201 in a manner similar to the flexible broach 104 shown in FIG. 1 . In this instance, it may be necessary to have cylinders 210 that increase in outer diameter toward the surface of the wellbore. The cylinders 210 with a smaller diameter can enter a deformed portion of the casing that would not permit passage of the cylinders having a larger diameter. Once the smaller diameter cylinders broach the wellbore, the larger diameter cylinders can be lowered to broach the wellbore to full gage.
FIG. 6 illustrates an elliptical cylinder 610 with an abrasive material such as crushed tungsten carbide 600 on an outside surface thereof. The elliptical cylinder 610 slips onto a cable next to adjacent elliptical cylinders to form a flexible broaching tool similar to the flexible broach portion 202 shown in FIG. 2 . The elliptical cylinder 610 has a major axis that orients within casing that has been deformed by a shifted wellbore to also have a major axis. In this manner, the elliptical cylinder 610 orients in a predetermined direction and the major axis is large enough to create a full gage slot by broaching as described herein.
While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | A method and apparatus for milling and/or broaching within a wellbore. A flexible broach runs into the wellbore and is located adjacent a portion of the wellbore to be broached. The broach reciprocates axially within the wellbore and removes at least part of the portion to be broached. Weight may be coupled to the broach, thereby applying a resultant side load for broaching an offset portion of the wellbore. The broach comprises a flexible member that may be a bare cable. When an abrasive material is disposed on an outer surface of the flexible member, the flexible member may be a cable, a continuous rod, or pressurized coiled tubing. Alternatively, sleeves positioned on the flexible member may have an abrasive material on their outer surface. A rotational mill that is either coupled to the broach or run in separately from the broach can further mill the wellbore. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates in general to devices and methods for dispensing flowable materials having high viscosities, and more particularly to the dispensing of soft serve frozen confections such as ice cream and the like.
A frozen confection, such as ice cream, frozen yogurt, sherbet, or sorbet, is termed "soft serve" when it is at a temperature within a range of approximately 10°to 20° F., for example 18° F., so as to have a viscosity that will enable it to flow through a dispensing nozzle into an edible cone or other suitable container whereupon the soft serve confection is immediately consumed. Traditionally, complex machines have been provided at retail outlets to manufacture, store and dispense soft serve frozen confections. The complexity of the machines makes them costly not only to acquire but also to maintain, both from an operational and a hygienic standpoint. Also, the quality of the soft serve confection is difficult to control due to variations in the ingredients loaded into the machine, and due to variations in the level of skill of the machine operators. Further, it is difficult to provide, at the retail level, a wide variety of types and flavors of soft serve frozen confections since the noted machines must each be dedicated to providing only a few types and flavors of confections at any given time, and since the number of machines per retail outlet is limited by cost and space considerations.
As an alternative to the above, it has been proposed that soft serve frozen confections be manufactured at a central facility, and then stored at the facility in portable containers at a low storage temperature of 0° F. or below. By use of a central manufacturing and storage facility, the cost and quality of the frozen confections could be more readily controlled. Also, an inventory of prefilled containers providing a wide range of types and flavors of frozen confections could be established. The containers could then be shipped on demand from inventory to retail outlets wherein they would be thawed or tempered to a "soft serve" temperature. The containerized soft serve frozen confections could then be dispensed at the retail outlet from a simpler and more compact machine that would only function as a dispenser and storage means.
Examples of dispensers for containerized soft serve confections are illustrated by U.S. Pat. Nos. 5,048,724, 5,069,364, 5,215,222, and 5,244,277, all of which are expressly incorporated herein. The noted patents disclose dispensers wherein collapsible or otherwise deformable containers are mechanically compressed to expel or extrude soft serve frozen confections therefrom for each individual serving. While the noted compression type soft serve dispensers arguably represent an advance in the art, it has been found that repeated compression of soft serve frozen confections, which can contain up to 40% air, may degrade the quality of the dispensed product. It is believed that repeated pressurization of the frozen confection within the container causes undesirable ice crystals to form within the confection, degrading the taste and texture of the dispensed confection. Although this effect is small or almost negligible for each pressurization/depressurization cycle, since the entire volume of confection within the containers of these patents is repeatedly pressurized the cumulative effect is substantial and noticeable.
Also, the discharge rate from the earlier noted patented devices, which mechanically compress the product, is highly dependent upon product viscosity and, therefore, product formulation and temperature. For example, high fat content chocolate ice cream having a relatively high viscosity may have to be dispensed at a higher "soft serve" temperature, or a higher pressure, than a lower viscosity sorbet.
It is therefore an object of the present invention to provide a dispenser for containerized frozen confections and the like of the soft serve type that can operate over a relatively wide "soft serve" temperature range wherein frozen confections at the same temperature, but of substantially different viscosities can be dispensed. It is a further object of the present invention to provide a dispenser that will eliminate repeated compression or pressurization of the frozen confection within the container, and minimize compression or pressurization of dispensed frozen confection, so as to avoid or at least minimize the above noted problems associated therewith. It is also an object of the invention to provide a dispenser that will dispense ice cream in controlled predetermined amounts for purposes of portion control. It is a further object of the invention to provide a delivery means including a dispensing valve which is operable to dispense viscous material with a minimum of compression or pressurization of the viscous material being dispensed therefrom.
It is to be noted that while the above background and subsequent description of the invention focus mainly on the dispensing of soft serve frozen confections, it is clearly contemplated by the inventors that the invention may have applications to the dispensing of other high viscous food products, such as prepared vegetables and nutritional supplements.
SUMMARY OF THE INVENTION
In accordance with the present invention, a dispenser for viscous material such as ice cream and the like preferably includes a supply source of viscous material constituted by a portable container for storing the viscous material. The dispenser also includes a delivery means for discharging the viscous material, and a pump means connected between the supply source and the delivery means to establish fluid communication therebetween.
The pump means includes a pump member which is reciprocally movable in two directions. When the pump member moves in the first of its two directions, it pressurizes the viscous material to thereby push the material toward the delivery means for discharge thereof and to simultaneously extract viscous material from the supply source by means of suction. The pump member is movable in the second or opposite of its two directions without causing substantial movement of the viscous material relative to the delivery means or the supply source.
In further accordance with the present invention, a dispenser is provided which is operable to dispense containerized frozen confections and the like of the soft-serve type over a relatively wide temperature and viscosity range. The dispenser utilizes a positive displacement pump that dispenses predetermined quantities of confection with minimal compression of the confection being dispensed, and eliminates compression of the confection in the container, thereby avoiding or at least minimizing the problems, e.g. ice crystal formation, present in the prior art dispensing methods.
In further accordance with the present invention, the delivery means includes a dispensing valve for discharging viscous material. The dispensing valve includes a valve body which provides an inlet port, an outlet port, and a chamber in fluid communication with said ports. The viscous material flows from the inlet port to the outlet port via the chamber when the valve is in an open condition.
The dispensing valve further comprises a poppet member contained within the valve body and movable between a closed position when seated and sealed against the outlet port, and an open position when unseated and spaced from said outlet port. When in the seated and sealed position, the poppet member precludes the flow of viscous material out of the outlet port. When in the open position, the poppet member permits the flow of viscous material out of the outlet port.
The poppet member provides a surface which is acted upon by the pressurized viscous material within said chamber. The dispensing valve also includes a biasing means, e.g. a compression spring, which biases the poppet member toward its closed position. The poppet member is movable to its open position against the bias force of the biasing means solely by viscous material pressure which is created by movement of the pump member in the first of its two directions. Movement of the poppet member to its closed position is a result of the combination of the biasing force and a transient reduced pressure condition or suction force developed within the chamber by the pump means during movement of the pump member in the second of its two direction.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further features of the present invention will be apparent with reference to the following description and drawings, wherein:
FIG. 1 is a front perspective view of a dispenser according to the present invention;
FIG. 2 is a side elevational view, in cross-section, of the dispenser of FIG. 1;
FIG. 3 is a side elevational view, in cross-section, of a dispensing pump, a portable container and a delivery means in accordance with the present invention;
FIGS. 4A-4D show the dispensing pump and delivery means of FIG. 3 in various sequential operating conditions;
FIG. 5 is a front exploded perspective view of the pump and dispensing valve;
FIG. 6 is a top plan view of a rack mounting block and rack according to the present invention;
FIG. 7 is a rear elevational view of a discharge cylinder of the delivery means according to the present invention;
FIG. 8 is a front elevational view of a conduit member of the dispensing pump according to the present invention;
FIG. 9A is a front elevational view of an alternative portable container according to the present invention;
FIG. 9B is a front elevational view of another alternative portable container according to the present invention;
FIG. 9C is a front elevational view of a further alternative portable container according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A dispenser according to the present invention is generally illustrated in FIGS. 1 and 2, and includes a thermally insulated dispensing cabinet 10 having opposed vertical side walls 12 (one shown), horizontal top and bottom walls 14 and 16, and a vertical rear wall 18. The bottom wall 16 is spaced from a supporting surface by a base member 20 which houses various components, such as a conventional refrigeration compressor (not shown) and a conventional condenser structure (not shown). A front portion of the cabinet 10 provides spaced upper and lower openings 22, 24 which are separated by an inset panel 26, the openings 22, 24 being closed by upper and lower doors 28, 30 which are preferably mounted for pivotal movement about their left edge using appropriate hinge structures, as illustrated most clearly in FIG. 1. A drip pan 31 is provided above the lower door 30 and is removably attached to the lower end of inset panel 26, as illustrated.
The upper door 28 provides control devices, such as push buttons 32 (one for each of the two dispensing pump means to be subsequently illustrated), to control dispensing of frozen confection, and one or more inside recesses or pockets 34 which receive and thermally insulate frozen confection delivery means, as will be described more fully hereafter. The panel 26, walls 12, 14, 16, and 18, and doors 28 and 30 of the dispensing cabinet 10 are thermally insulated to reduce the energy required to maintain the temperature provided in the interior of the cabinet, which is typically between about 10°to 20° F.
FIG. 2 shows that the interior of the dispensing cabinet 10 is generally divided into upper and lower compartments or sections 36 and 38. The lower section 38 serves as a storage and temperature conditioning (tempering) cabinet whereby the temperature of a plurality of portable containers 40 of frozen confection, which hold between about two to five gallons of frozen confection and are typically introduced into the tempering cabinet at a temperature of about 0° F. or below, slowly rises to a dispensing temperature of between about 10°to 20° F. over an extended period of time, generally between about twelve and thirty-six hours. After the frozen confection within a particular container 40 is tempered or brought to the dispensing temperature, that particular container is ready to be placed in the upper section 36 and the confection dispensed therefrom upon demand.
The lower section 38 also houses refrigeration equipment including an evaporator structure 42 and a plurality of fans 44 that work in conjunction with the compressor and condenser structure housed within the base member 20 in the conventional manner as is known in the art. The fans 44 are operable to circulate relatively warmer air from the upper and lower sections 36, 38 of the dispensing cabinet 10 past the evaporator 42 and to circulate relatively colder air throughout the dispensing cabinet 10 as a result of the evaporators cooling effect. Temperature within the sections 36, 38 is preferably controlled by introducing electrical heat via resistance-type heating elements (not shown) in response to control signals provided by a proportional temperature controller (not shown), as is known in the art, to offset the cooling capacity of the refrigeration equipment and thus maintain the temperature within the upper and lower sections within a predetermined range, i.e. the dispensing or "soft serve" temperature. Naturally, any number of known equivalent temperature maintenance systems can be used without departing from the scope of the present invention.
For reasons of cleanliness, the upper section 36 is preferably separated by a dividing partition or wall 46 into front and rear regions 48 and 50. The rear region 50 houses a reversible motor 52, which preferably operates on standard 120 V, 60 Hz power, and a gear reduction unit 54. The front region 48 houses a dispensing pump means 56, which will be described hereafter.
A sliding rack 58, which is preferably enclosed by a flexible bellows 60, extends through an opening in the dividing wall 46 and operably connects the motor 52 to the dispensing pump means 56 via the gear reduction unit 54. FIG. 6 shows that the sliding rack 58 is movably mounted for reciprocating motion within a groove or channel 62 in a mounting block 64 beneath the motor 52 and provides a series of lengthwise extending teeth 66 which mesh with a pinion gear 68 provided by the gear reduction unit 54 (see FIG. 2). As the motor 52 is operated in a first mode or direction, the rack 58 is moved in a corresponding first direction by the pinion gear 68. Similarly, when the motor 52 is reversed to operate in a second mode or direction the rack 58 is moved in an opposite or second direction by the pinion gear 68. As such, the rack 58 and dispensing pump means 56, which are connected together as will be subsequently illustrated, are reciprocally operated.
Within the mounting block 64 are provided limit switches 70 and 72 which, as the rack 58 travels back-and-forth, sense the position of a notch 73 in the rack 58 and control the operation of the motor 52 accordingly. More specifically, position-relative signals provided by the limit switches 70 and 72 are used to control when the motor 52 is reversed to operate in the second mode or direction and to turn the motor off when a complete dispensing cycle has been completed. As the motor is operated in the first mode or direction, and the limit switch 70 engages the notch 73, the motor 52 will be reversed to operate in the second mode or direction. When the limit switch 72 engages the notch 73 the motor 52 will be turned off. By provision of additional notches in the rack, a number of different rack travel or stroke lengths, and a corresponding number of different volumes of dispensed frozen confection (i.e., 4 oz., 6 oz., 8 oz.), can be provided.
Alternatively, the limit switches 70, 72 could be replaced by an optical encoder which would count the number of revolutions of a motor shaft (not shown) or the pinion gear 68 and control the motor 52 such that a predetermined volume of material is dispensed. Other alternatives include a timer means which would measure the time period of motor operation in each direction corresponding to a predetermined volume of dispensed material or a stepper motor under microprocessor control which would track and control the position of a pump piston and, therefore, the volume of dispensed material. Other equivalent control means and methods could also be provided without departing from the scope of the present invention.
With continuing reference to FIG. 2, and also to FIGS. 3-8, a terminal end 74 of the rack 58 is pinned or otherwise attached to a connector 76 which releasably receives a piston rod 78 provided by the dispensing pump means 56. In the illustrated and preferred embodiment a spring clip 80 releasably attaches the piston rod 78 to the connector 76 to aid in quick assembly and disassembly of the dispensing pump means 56 for cleaning or maintenance. Any number of equivalent attachment means can be substituted for this arrangement without departing from the scope of the present invention.
The dispensing pump means 56 comprises a dispensing pump 82 and delivery means 84. Although two such dispensing pump means 56 are contained within the cabinet 10 of the illustrated and preferred embodiment, it is anticipated that the size and number of dispensing pumps 82, delivery means 84, and containers 40 will vary depending upon the anticipated volume of frozen confection to be served, and the number of flavors or types of confections desired to be dispensed at any given time.
The dispensing pump 82 provides a conduit member or pump cylinder 86 and the delivery means 84 provides a discharge cylinder 88. The conduit member 86 and discharge cylinder 88 are removably connected to one another by connector means 89, as will be described more fully hereafter. The conduit member 86 serially connects the container 40 and the delivery means 84 and has a first or rear end which is closed by a removable plug-like end wall member 90 and an opposite front or second end having an integral end wall 92. A cylindrical outlet spout or male connection 94 projects outwardly from the second end of the conduit member 86 and provides a pair of annular, axially spaced apart ribs 96 and a series of radially extending mounting tabs 98 (FIGS. 5 and 8). The annular ribs 96 define a groove therebetween for receipt of an O-ring 100, while the tabs 98 are adapted to be received by an inlet or female mounting portion 102 of the discharge cylinder 88 in a twist-and-lock fashion, as will be apparent from the discussion to follow. The outlet spout 94, which defines a conduit member outlet port 104, and the conduit member 86 are generally coaxial, with the outlet spout 94 having a smaller diameter than the conduit member 86.
Near the rear or first end of the conduit member 86 is provided an inlet port 106. The inlet port 106 includes an upwardly extending inlet spout 108 with which the container 40 communicates. In the preferred embodiment, a container adapter and mounting member 110 is provided to secure and support the container 40 on the inlet spout 108 of the conduit member 86.
As is best shown in FIG. 3, the adapter member 110 provides a downwardly extending, centrally located, cylindrical member 112 which receives the inlet spout 108, an upwardly extending cylindrical member 114 which projects into a lower end of the container 40, and a ring shaped body member 116. An outer peripheral portion 118 of the body member 116 receives and vertically supports a lower peripheral edge of the container 40, as illustrated.
The inlet spout 108 abuts an annular surface or stop 119 of the adapter 110 to limit insertion or travel of the spout 108 into the downwardly extending cylindrical member 112. Preferably, the downwardly extending cylindrical member 112 of the adapter 110 is permanently attached to the inlet spout 108 by adhesives, ultrasonic welding, or the like. Alternatively, the adapter member 110 could be integrally formed with the conduit member 86. Further, the adapter 110 can be removably secured to the inlet spout 108 by a threaded connection or other means to allow the adapter member 110 to be replaced by another adapter member designed to receive a different container having, for example, a larger or smaller diameter than the illustrated container 40.
The upwardly extending cylindrical member 114 is preferably resilient and radially deformed inwardly as it is received by the container 40 to seal the engagement therebetween in a fluid-tight manner. An annular rib 120 is provided on the outer surface of the upwardly extending cylindrical member 114 to further seal the adapter member 110 on the container 40. Alternatively, the upwardly extending cylindrical member 114 could be formed of a more radially stiff material and provided with an O-ring or other appropriate sealing means to sealably secure the container 40 to the adapter 110. Also, the container 40 could provided a threaded spout which could be threadably received by the upwardly extending cylindrical member 114 having mating threads.
From the foregoing it should be clear that the adapter member 110 described herein is specially designed for receipt of the preferred and illustrated container 40. Since the dispensing pump means 56 is adapted for use with various types of containers, some of which are illustrated hereinafter in FIGS. 9A-9C, the present invention is not to be limited to the specific adapter member 110 or container 40 disclosed herein. Rather, it is anticipated that the adapter member 110 will be interchangeable with various other equivalent adapter members for supporting and mounting various other containers.
Adjacent the inlet port 106, the rear or first end of the conduit member 86 provides a groove for threadably receiving threads 122 provided by the end wall member 90 to releasably secure the end wall member 90 thereto. The threads 122 engage an annular terminal or outer surface 123 of the conduit member 86 to limit insertion or travel of the end wall member 90 into the conduit member (see FIGS. 3 and 5). The end wall member 90 is generally cylindrical, and has a cut-away top portion 124 which aligns with the inlet port 106 when the threads 122 engage the outer surface 123 of the conduit member 86 to thereby allow viscous material to be freely introduced into the conduit member 86, as illustrated in FIGS. 3 and 5. The end wall member 90 has a cylindrical outer surface 126 which, with the aid of an O-ring 128, sealingly engages the inner circumference of the conduit member 86 adjacent the inlet port 106, as illustrated. A pair of gripping tabs 130 extend from the end wall member 90 to allow a user to rotate the end wall member 90 for installation and removal thereof.
A central circular hole 132 (FIG. 5) is provided in the end wall member 90 through which the piston rod 78 slidably extends. A circular groove surrounds the circular hole 132 and receives an O-ring 134 which slidably seals the engagement of the end wall member 90 and the piston rod 78. Thus, the end wall member 90 seals the rear or first end of the conduit member 86 while allowing the piston rod 78 to move reciprocally and axially relative to the conduit member 86. While the preferred end wall member 90 is illustrated in the drawings and described hereinabove, it should be clear that various other means could be substituted for the illustrated end wall member 90 without departing from the scope of the present invention.
The dispensing pump 82 comprises an assembly including a pump member or valved piston 136 (see FIG. 5) in addition to the piston rod 78, conduit member 86 and the end wall member 90. The piston 136 has coaxial inner and outer piston members 138 and 140 which are axially movable along the piston rod 78 relative to one another in a telescoping manner. As will be described more fully hereafter, there is lost motion between the inner and outer piston members 138, 140 to allow the inner piston member 138 to move relative to the outer piston member 140 during operation of the dispensing pump 82.
The outer piston member 140 includes a series of arms 142 that extend radially inwardly from an inner annular surface 144 to a central hub 146 (see FIG. 5). A flow path for viscous material is defined by the hollow or open area between the hub 146, arms 142, and inner annular surface 144. The hub 146 is formed of a resilient plastic and defines a slot-like snap-on, snap-off, U-shaped opening 148 for releasably receiving a reduced diameter portion or extension 78a of the piston rod 78. Preferably, the open end of the U-shaped opening 148 is slightly smaller than the diameter of the piston rod 78, causing the arms of the "U" to outwardly deform and releasably snap the piston rod 78 into place during assembly. Snap-fitting the outer piston member 140 on the reduced diameter portion 78a of the piston rod 78 facilitates assembly and disassembly of the dispensing pump means 56 for cleaning. The reduced diameter portion 78a of the piston rod 78 provides a terminal knob or button 150 to retain the outer piston member 140 thereon. The knob or button 150 is sized to allow its insertion between the arms 142 during assembly of the piston rod 78 on the outer piston member 140.
The outer piston member 140 also provides an outer cylindrical surface 152 and forward and rearward facing annular surfaces 154 and 156 (see FIG. 3). The rearward facing annular surface 156 is radially contoured or beveled, as illustrated, to direct or funnel viscous material into the hollow interior portion of the outer piston member 140. The forward annular surface 154 is generally planar. The outer cylindrical surface 152 is designed to slide adjacent the inner surface of the conduit member 86. A relatively forward end of the outer cylindrical surface 152 provides an annular groove for receipt of an O-ring 158 which seals the interface between the outer piston member 140 and the conduit member 86. More specifically, the O-ring 158 slidably and sealably engages the inner surface of the conduit member 86.
The inner piston member 138 has an outer cylindrical surface 162, forward and rearward-facing surfaces 163, 164, and a centrally located threaded bore 166. The threaded bore 166 allows the inner piston member 138 to be threadably and removably secured to the piston rod 78. The outer cylindrical surface 162, which slidably mates with the inner annular surface 144 of the outer piston member 140, has formed therein an annular or circumferential groove for receipt of an O-ring 168 which seals the engagement of the outer cylindrical surface 162 with the inner annular surface 144 of the outer piston member 140. As will be described more fully with regard to operation of the dispensing pump 82, when the inner piston member 138 moves into sealing engagement with the outer piston member 140 there is, in accordance with the present invention, a shearing action between the mating surfaces provided by the inner annular surface 144 of the outer piston member 140 and the outer cylindrical surface 162 of the inner piston member 138. The shearing action or interface area created at the mating surfaces helps to remove or shear particulate material, such as nuts and fruit, from the area of sealing engagement between inner and outer piston members 138 and 140, thereby insuring sealing engagement between the inner and outer piston members.
Thus, the inner piston member 138 is fixed to the piston rod 78 and cannot move relative thereto during operation of the dispensing pump 82 while the outer piston member 140 is removably and slidably secured to the piston rod 78 and has a limited range of axial motion relative to the inner piston member 138. In the illustrated embodiment, movement of the inner piston member 138 relative to the outer piston member 140 (i.e., the lost motion) is limited to the distance between the button or knob 150 on the piston rod 78 and the forward facing surface 163 of the inner piston member 138, less the thickness of the hub 146.
The dispensing pump 82 is assembled outside of the conduit member 86 by snap fitting the reduced diameter portion 78a of the piston rod 78, which already has the inner piston member 138 threadably secured thereto, to the hub 146 of the outer piston member 140. The piston 136 is inserted into the rear or first end of the conduit member 86 and the end wall member 90 is pushed onto the piston rod 78 and threadably secured to the conduit member 86.
The dispensing pump 82 is placed in the front region 48 (see FIG. 2) of the cabinet 10 such that the end of the piston rod 78 extends into the connector 76 and is attached, via the connector 76 and spring clip 80, to the rack 58 as discussed earlier. The conduit member 86 provides exterior mounting projections 170 (see FIG. 5) which are secured to a cabinet-provided support surface (not shown) by conventional fasteners such as thumb screws (not shown) to complete installation of the dispensing pump 82 within the cabinet 10.
With reference to FIGS. 3 and 7, the mounting portion 102 of the discharge cylinder 88 has a cylindrical body 174 including an outer end with inner and outer annular retaining walls 176, 178, a discontinuous clover-shaped annular groove 180, and a series of stop surfaces 182. The stop surfaces 182 are provided between the inner and outer retaining walls 176, 178, and form the discontinuities in the annular groove 180. Radial notches 184 are provided in the outer retaining wall 178 to receive the mounting tabs 98 of the conduit member outlet spout 94. During assembly, and with the conduit member 86 of the dispensing pump 82 fixed in position within the cabinet 10, the inlet or female mounting portion 102 of the discharge cylinder 88 is positioned relative to the male connection or outlet spout 94 such that the cylindrical body 174 slidably receives the male connection or outlet spout 94 and the mounting tabs 98 are received by the notches 184 in the outer retaining wall 178. Thereafter, the discharge cylinder 88 is rotated counterclockwise, causing the mounting tabs 98 to slide into the annular groove 180 between the inner and outer retaining walls 176, 178, with rotation being limited by the stop surfaces 182 such that the discharge cylinder 88 is generally vertically oriented, as illustrated. The O-ring 100 provided on the outlet spout 94 slidably engages the inner wall of the cylindrical body 174 to seal the union of the female mounting portion 102 and the male connection or outlet spout 94.
In addition to the inlet or mounting portion 102, the discharge cylinder 88 includes a hollow main body 186 and a reduced-diameter lower cylindrical extension or nozzle 188. The inlet or mounting portion 102 projects from the main body 186 and serves as a valve inlet port thereto. The main body 186 and nozzle 188 receive a piston-like poppet member 190 that is reciprocally movable within the discharge cylinder 88 and serves as a delivery valve for viscous material from the conduit member 86 toward and through an outlet provided at a lower end of the nozzle 188. A side of the main body 186 remote from the inlet or mounting portion 102 generally matches the shape of the poppet member 190 while a side proximate to the mounting portion 102 is scooped-out to allow viscous material to enter the discharge cylinder 88, as illustrated. An annular shoulder surface 192 surrounds an upper end of the nozzle 188 and serves as a seat against which the poppet member 190 seals.
The outer surface of the discharge cylinder 88 provides a pair of lugs or ears 194 which are adapted to be releasably received by slotted openings 196 (FIG. 5) in a cap 198 which is part of the delivery means 84. Although the cap 198 is preferably attached to the main body 186 with a bayonet-type connection as illustrated, it should be clear that threads or other suitable attachment means could be employed without departing from the scope of the present invention. The cap 198 includes projections 200 to facilitate user-rotation thereof during assembly and disassembly of the deliver means 84 for cleaning and maintenance and a vent hole 199 (FIG. 5).
The delivery means 84 includes a compression or coil-type biasing spring 202 in addition to the poppet member 190, discharge cylinder 88, and cap 198. The poppet member 190 is slidably received within the discharge cylinder 88 and provides an enlarged diameter upper portion 204 and a reduced diameter lower portion 206. The upper portion 204 provides an annular groove for receipt of an O-ring 208 which slidably seals against the inner surface of the main body 186 at a location upwardly spaced from the mounting portion 102 providing the valve inlet port. The lower portion 206 provides an annular groove within which an O-ring 210 is received, as illustrated. The O-ring 210 is provided to seal or seat against the annular shoulder surface 192 thereby closing the valve. A frustoconical transition surface 212 is provided intermediate the upper and lower portions 204 and 206 of the poppet member 190. The transition surface 212 serves as a surface against which the force of pressurized viscous material bears and forces the poppet member 190 upwardly, as will be described more fully hereafter.
The lower portion 206 of the poppet member 190 has a closed bottom end 214 (see FIG. 3) and is slidably received within the nozzle 188. As the poppet member 190 moves downwardly in the discharge cylinder 88, there is a shearing action between edge portions provided by an outer surface of the lower portion 206 of the poppet member 190 and the inner surface of the nozzle 188 to help remove particulate matter, such as nuts or fruit, from the nozzle 188.
The upper portion 204 of the poppet member 190 provides a cup shaped interior having an upstanding cylindrical member 216 which receives a lower end 218 of the spring 202. An upper end 220 of the spring 202 is received by a cylindrical member 222 which projects downwardly from the center of the cap 198.
The delivery means 84 is assembled by sliding the poppet member 190 downwardly into the discharge cylinder 88. Thereafter, the upper end 220 of the coil spring 202 is placed over the cylindrical member 222 of the cap 198, and the cap is placed over the open top end of main body 186 of the discharge cylinder 88 such that the lower end 218 of the spring 202 is received by the upstanding cylindrical member 216 of the poppet 190. The cap 198 is secured to the discharge cylinder 88 by pushing downwardly to compress the spring 202 and then rotating the cap 198 to allow the lugs 194 provided by the discharge cylinder 88 to be received within the slotted openings 196 of the cap 198. At this point the O-ring 210 on the lower portion 206 of the poppet member 190 is seated on the annular shoulder surface 192 due to the bias of the compressed spring 202 and the O-ring 208 of the upper member 204 is in sealing engagement with the inner surface of the main body 186 at a location upwardly spaced from the inlet port or mounting portion 102 as illustrated in FIG. 3. Thereafter the discharge cylinder 88 is attached to the conduit member 86 as described hereinbefore.
With the dispensing pump means 56 assembled and a container 40 of viscous material, such as frozen confection, placed and sealed upon the inlet spout 108, dispensing of viscous material is ready to begin. Initially, the conduit member 86 is charged or primed with viscous material from the container 40 by operating the dispensing pump means 56 through one or more cycles, as will be described hereafter, to introduce or fill the conduit member 86 with viscous material. As noted hereinbefore, positioning of the piston 136 within the conduit member 86 is controlled by the rack 58 and motor 52 in response to signals from the limit switches 70 and 72.
The dispensing pump means 56 is generally in the configuration shown in FIG. 4A at the start of a dispensing cycle wherein chambers A and B in front of and behind the piston 136, respectively, are fully charged with viscous material. Manipulation of the control devices or push buttons 32 (see FIG. 1) operates the motor 52 in a first mode or direction in which the pinion gear 68 drives the rack 58 and associated piston rod 78 leftwardly (as shown in FIG. 4A) through the conduit member 86. Since the outer piston member 140 is in sealing engagement with the conduit member 86 and is slidably mounted on the reduced diameter portion 78a of the piston rod 78, there is lost motion between the inner and outer piston members 138, 140, and the inner piston member 138 moves toward and into sealing engagement with the outer piston member 140 (FIG. 4B). As such, the inner and outer piston members 138 and 140 are in sealing engagement with each other and are prepared to move together down the conduit member 86 toward the integral end wall 92.
As the piston 136 moves along the inner surface of the conduit member 86, the viscous material in region A in front of the piston 136 is pressurized and therefore pushed or pumped toward the outlet port 104 while a vacuum or low pressure condition is simultaneously developed in region B behind the piston 136. The vacuum or low pressure condition created in the conduit member 86 suctions or evacuates viscous material from the container 40 into region B behind the piston 136.
The pushed or pumped viscous material flows through the outlet port 104 and into the main body 186 of the discharge cylinder 88, below the transition surface 212 of the poppet member 190. The pressurized or pumped viscous material provided by movement of the piston 136 bears against the transition surface 212 and forces the poppet member 190 to move upwardly against the bias of the spring 202, thereby unseating the O-ring 210 from the shoulder surface 192 and thus allowing viscous material within the discharge cylinder 88 to be dispensed from the cylindrical extension or nozzle 188.
At the end of a discharging or dispensing stroke, the dispensing pump means 56 is generally positioned as shown in FIG. 4C. Although the piston 136 is no longer pushing or pumping viscous material out of the nozzle 188, the poppet member 190 of the delivery means 56 does not return to its sealing position because the spring bias of the spring 202 is preferably not strong enough to force the viscous material remaining within the discharge cylinder 88 out of the nozzle 188. Naturally, the spring strength could be chosen such that the spring 202 would force the poppet member 190 to seat on the shoulder surface 192 at the end of the discharge stroke.
However, increasing the spring strength would also increase the pressure necessary to overcome the spring bias and unseat the poppet member 190 from the shoulder surface 192 during the discharge stroke and would correspondingly increase the energy required to dispense viscous material from the region A toward an amount comparable to the energy expended in suctioning or evacuating viscous material out of the container 40 and into region B. In the preferred and illustrated embodiment it is desired that the energy required to push or pump the viscous material from region A out of nozzle 188 be relatively small or minimal as compared with the energy expended in suctioning or evacuating viscous material out of the container 40 and into region B of the conduit member 86. Moreover, increasing the spring strength may result in an unwanted high velocity burst or discharge of viscous material from the nozzle 188. Also, if a higher strength spring is employed, the poppet member 190 may only move upwardly relative to the shoulder surface 192 a short distance and therefore act as a strainer to restrict or prevent dispensing of solid particulates, such as nuts and fruit, through the nozzle 188. Furthermore, the use of a higher strength spring will result in additional compression or pressurization of the viscous material to be dispensed, which may lead to undesirable ice crystal formation, as discussed earlier.
As the motor 52 is reversed to operate in a second mode or reverse direction due to signals from the limit switch 70, the outer piston member 140 remains stationary due to its sealing engagement with the conduit member 86 and the slidable mounting of the outer piston member 140 on the reduced diameter portion 78a of the piston rod while the inner piston member 138 moves rearwardly relative to the outer piston member 140. As the inner piston member 138 moves rearwardly relative to the outer piston member 140, the O-ring 168 slides across the inner annular surface 144 of the outer piston member 140 and produces a vacuum or reduced pressure condition in region A and discharge cylinder 88. The transient vacuum or suction force thus created tends to draw a small amount viscous material within the cylindrical extension or nozzle 188 back into the main body 186 and cooperates with the spring 202 to return the poppet member 190 to the sealing or seated condition illustrated in FIG. 4D.
Further rearward movement of the piston rod 78 causes the piston 136 to be configured as shown in FIG. 4D wherein the inner and outer piston members 138 and 140 are spaced from each other and the terminal knob or button 150 is in contact with the hub 146 and forces the outer piston member 140 to move rearwardly with the piston rod 78 and inner piston member 138. As the piston 136 is pulled through the viscous material which had previously been drawn or suctioned into region B by the piston 136 during the discharge or dispensing stroke, the inwardly-directed contour of the rearward annular surface 156 funnels or directs viscous material into the open interior of the outer piston member 140 wherein it flows past the arms 142 and hub 146 and into region A at the forward side of the piston 136. As such, the inner piston member 138 acts as a valve mechanism to allow the piston 136 to pass through the viscous material without causing substantial movement of the viscous material through the conduit member 86 in the rearward direction. Movement of the viscous material past the inner piston member 138 and through the outer piston member 140 homogenizes or stirs the viscous material, so as to enhance the consistency and texture of the dispensed product. When the piston 136 reaches the terminal position illustrated in FIG. 4A at the completion of a dispensing cycle, the limit switch 72 engages the notch 73 and turns the motor 52 off (see FIG. 6).
As the dispensing pump means 56 is operated through each of a number of dispensing cycles, viscous material is dispensed upon demand from the container 40 and the container collapses or otherwise deforms and thereby, in effect, reduces its internal volume available for holding viscous material. The container illustrated in FIGS. 2-4D provides a cylindrical outer wall 237, rigid fixed top and bottom end walls 238, 239 and an inner flexible bag 240, The cylindrical outer wall is preferably formed of card board or the like while the end walls 238, 239 are preferably formed of plastic or stainless steel. The bag 240, which is preferably formed of a flexible plastic, is preferably secured at a midpoint thereof to the interior of the cylindrical outer wall 237 to help insure that the bag 240 properly collapses toward the inlet spout 108 during evacuation of viscous material from the container 40. The closed end of the flexible bag 240 has secured thereto a stiff or rigid disc 241, preferably of plastic, which moves downwardly with the bag 240 as viscous material is evacuated therefrom and prevents the closed end of the bag 240 from being suctioned into the inlet spout 108 by operation of the dispensing pump 82. The open end of the bag 240 is crimped together with the bottom end wall 239 to the lower edge of the cylindrical outer wall 237, as illustrated best in FIGS. 3-4D. Naturally, other means of sealably connecting the bag 240 to the bottom end wall 239 and the outer wall 237 are known in the art and could be employed.
Alternatively, with reference to FIG. 9A, a container 40' which comprises a coiled wire or spring member 232 trapped between inner and outer cylindrical plastic layers 234, 236, could be used in place of the container 40. One or more turns of coiled wire is provided at the top and bottom ends of the container 40' to help stiffen the ends. Another alternative container 40'" is shown in FIG. 9B provides a rigid cylindrical outer wall 224, rigid top and bottom fixed end walls 226 and 228, and an axially movable piston 230. The piston 230 is generally disc-shaped and is located above the viscous material to be dispensed and moves downwardly with the material as it is drawn or suctioned toward the inlet spout 108 by operation of the dispensing pump means 56. For a more detailed description of the container 40, see U.S. Pat. No. 5,244,277, which has previously been incorporated herein by reference. A third alternative container 40'" is shown in FIG. 9C wherein the container is of the collapsible bellows type having a series of pleated folds 244 to allow the container 40'" to collapse toward the inlet spout 108. For a more detailed description of the container 40'" illustrated in FIG. 9C, see U.S. Pat. No. 5,215,222, which has been previously incorporated herein by reference.
It should be understood that the term "collapsible container" as used herein is intended to refer to containers wherein the available volume for viscous material storage is reduced as viscous material is dispensed from the container. As such, the term "collapsible container" shall have its broadest possible meaning and includes containers which have deformable sidewalls or axially movable pistons or ends walls, as disclosed in the above-noted patents, and any equivalent containers which deform, are reconfigured, or change shape to alter the internal volume available for storage of viscous material as viscous material is dispensed therefrom.
When viscous material will not be dispensed for a period of time, such as at the end of the working day, it is desirable to remove the delivery means 84 from the dispensing pump 82. The delivery means 84 is removed or unattached from the dispensing pump by rotating the discharge cylinder 88 clockwise to align the mounting tabs 98 of the male connection or outlet spout 94 with the notched openings 184 in the outer retaining wall 178 of the inlet or female mounting portion 102, and pulling the discharge cylinder 88 away from the dispensing pump 82. Thereafter, a valved or vented cap (not shown) can be placed on the male connection or outlet spout 94. The cap can be a plug which is inserted into the outlet spout 94 and which will allow viscous material to flow therethrough if the pump is unintentionally or accidentally operated without the dispensing means 84. The provision of a valved or vented cap would prevent damage to the dispensing pump means due to an overload or overpressure being developed within the conduit member 86. Since there are several structures for providing this function known in the art, and since the cap does not form a part of the present invention, no specific structure for the cap has been illustrated in the present application.
Once the cap is installed on the outlet spout 94, the viscous material within the conduit member 86 is isolated from atmosphere and foreign material is prevented from being introduced into the conduit member 86 via the outlet spout 94. If desired, the container 40 and dispensing pump 82 can be removed from the cabinet 10 and placed in storage until further dispensing is desired. Otherwise, the container 40 and dispensing pump 82 can remain within the dispensing cabinet 10 until the next time dispensing is desired, at which point a clean delivery means 84 can be reattached to the conduit member 86 via the connector means 89, as described earlier. By providing a removable delivery means 84, only the portion of the viscous material which is contained within the delivery means 84 must be discarded at the end of the working day, the viscous material within the conduit member 86 being retained for dispensing at a later time. Moreover, only the delivery means 84 must be disassembled for cleaning at the end of the working day. This represents an improvement in the art wherein a greater volume of viscous material must be discarded or wasted when the dispenser is not to be operated for a period of time and wherein the entire pump must be disassembled and cleaned at the end of each working day.
It should be further understood that the electric motor 52 described herein to drive the dispensing pump means 56 can be replaced by an type of power-operated means (i.e., non-manual), such as hydraulic or pneumatic drive means, and the like. Therefore, the term "motor driven" used in the claims appended hereto shall be given its broadest possible scope, and shall not be limited to the electric motor described hereinbefore. Furthermore, the inventors contemplate that the dispensing pump means could be non-motor driven, i.e., that it could be adapted for manual operation.
While the preferred embodiment of the present invention is shown and described herein, it is to be understood that the same is not so limited but shall cover and include any and all modifications thereof which fall within the purview of the invention. For example, while preferred, the dispensing cabinet 10 need not include a tempering cabinet. Also, although an automatic poppet-type valve is disclosed as part of the delivery means of the present invention, it is clear that other types of manual or automatic valves could be employed without departing from the scope and spirit of the invention as defined by the claims appended hereto. Moreover, several equivalent types of containers can be used with the dispensing pump means 56 of the present invention. Likewise, the sealing O-rings described herein are interchangeable with other suitable sealing means. It is also contemplated that the conduit member 86 and discharge cylinder 88 could be integrally formed as a single unit and that the portable containers described herein could be replaced by a refillable viscous material receiving hopper or receptacle or other non-portable container. Therefore, the scope of the present invention is not to be limited to the preferred embodiment illustrated herein, but is rather only defined by the claims appended hereto. | A reciprocating piston with an integral valve moves in a first direction within a cylinder to pressurize viscous material contained therein, such as ice cream or the like, thereby pushing it out of a dispensing nozzle located at one end of the cylinder while simultaneously extracting viscous material from a collapsible container into the other end of the cylinder by suctioning the material from the container. When the piston moves in a second direction, the integral valve opens to allow the piston to pass through the previously suctioned viscous material then within the cylinder. The dispensing nozzle includes a normally closed, spring-biased valve opened by the force of the pressurized material, closing of the valve being assisted by a transient suction force occurring as the valved piston begins to move in the second direction through the material. Suctioning the material from the collapsible container, as opposed to compressing the container to expel the material, is preferable when the material contains entrapped gas, as is the case with ice cream, since repeated compression of such containerized material can diminish its quality. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to an iron device, and more particularly, to a steam iron capable of adjusting the amount of spraying steam freely in ironing
BACKGROUND OF THE INVENTION
[0002] The electrical iron of prior art comprises a housing with a handle, a water container and a steam control device are disposed inside the housing, an electric heating plate is disposed in the lower portion of the housing, and the housing is provided with a power switch and a control button of the steam control device. The steam control device is used for controlling the water in the container to flow to the electric heating plate to generate steam. The steam generating method of the prior iron can be divided into two ways: first one, spraying steam: i.e. the water in the container continuously drip on the electric heating plate by the steam control device, thus a few of steam is continuously generated and sprayed out continuously through the outlet of the electric heating plate 2 , Second way, forceful spraying steam, or flash steam: i.e. the water in the container flow to the electric heating plate in a certain amount by the steam control mechanism, then large amount of steam generated in a short time sprayed out from the outlet of the electric heating plate abruptly. A CN utility model with the title of “Electric iron with forceful spraying steam” is disclosed in CN publication NO:2081850, application NO 91202225.6, in which the two ways of spraying steam are detailedly disclosed. However, the iron of the prior art has the following drawbacks: firstly, the amount and the duration time of the flash steaming can not be changed freely, if the user need large amount and continue steam in ironing corrugation, the iron of the prior art can not meet this requirement. Secondly, the controlling of generating forceful spraying steam need to press or rotate a special button, this is not fit for the operation requirement of the continue ironing.
SUMMARY OF THE INVENTION
[0003] The primary object of the present invention is to provide a steam iron capable of adjusting the amount and during time of the flash steam freely in continue ironing.
[0004] This object of the invention is achieved by providing: a steam iron comprising a housing with a handle, a water container, a steam control device and a vapor chamber provided with an electric heating plate; said steam control device comprising a pressure sensor mounted on the handle of said housing, a control board with a microprocessor and an pump for providing the water into said vapor chamber; said pump is controlled by said control board according to the pressure signal provided by said pressure sensor.
[0005] In a preferred embodiment of the present invention, said pump disposed inside said housing and provided with an inlet connected to said water container and an outlet connected to said first electric heating plate.
[0006] In another preferred embodiment of the present invention, said pump disposed inside an iron station and provided with an inlet connected to the water container and an outlet connected to said electric heating plate; said pump pumps the water in the water container to a second electric heating plate of the iron body via tube under the control of the control board.
[0007] The object of the present invention also can be achieved by providing: a steam iron comprising a housing with a handle, a water container, a steam control device, and a vapor chamber provided with a first electric heating plate; said steam control device comprising a pressure sensor mounted on the handle of said housing, a control board with a microprocessor and an execution unit providing the vapor into said vapor chamber to be secondly heated and sprayed out; said execution unit is controlled by said control board according to the pressure signal provided by said pressure sensor.
[0008] In another embodiment of the present invention, said execution unit comprises a pump and an evaporator, said pump pumps the water into said evaporator under the control of the control board for generating the steam and then said steam is transported to said electric heating plate via the steam tube to be secondly heated and sprayed out.
[0009] In a preferred embodiment of the present invention, said pump, said evaporator and said water container are disposed in the iron station;
[0010] In second embodiment, said water container is a boiler and said execution unit is an electromagnetic valve, said electromagnetic valve transport the steam generated in said boiler to said electric heating plate via the steam tube under the control of the control board and the steam is secondly heated and sprayed out.
[0011] In a preferred embodiment, said electromagnetic valve and said boiler are disposed inside said iron station.
[0012] The steam iron of the present invention is to mount a pressure sensor on the handle of the iron body which is under the palm, the user can touch the pressure sensor by adding the grasping force on the handle. The execution unit is controlled by the control board with microprocessor according to the pressure signal from the pressure sensor to transport the water in the water container to the electric heating plate so as to be heated to generate steam and sprayed out; Or the execution unit is controlled by the control board with microprocessor according to the pressure signal from the pressure sensor to transport the water in the water container to the electric heating plate so as to be secondly heated to generate steam and ejected out; The user can adjust the steam amount and spraying time freely in continue ironing, and doesn't need to stop the ironing to push the other button or rotate special knob, thus is facilitate to adjust the steam amount in continue ironing. Especially, if large amount of steam is needed when the user is ironing a relative big corrugation, it only need to press the pressure sensor on the handle by a certain pressure, then the iron device can add the steam amount automatically; thus the ironing is more user-friendly and more meet to the purpose of the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a sectional view of the steam iron in embodiment 1 of the present invention;
[0014] FIG. 2 is a sectional view of the steam iron in embodiment 2 of the present invention;
[0015] FIG. 3 is a sectional view of the steam iron in embodiment 3 of the present invention;
[0016] FIG. 4 is a sectional view of the steam iron in embodiment 4 of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
[0017] In this embodiment, the steam iron of the present invention is shown in FIG. 1 , the lower portion of the housing 110 is provided with an electric heating plate 120 . A power switch 130 is disposed on the handle 111 of the housing 110 . The top surface of the handle 111 is provided with an opening and a cover 112 made of flexible material is dispose on the opening A pressure sensor 140 is disposed beneath the opening in the handle 111 . A control board 150 with microprocessor, a pump 160 and a container 170 are mounted inside the housing 110 . the inlet 161 of the pump 160 is connected to the container 170 , and the outlet 162 of the pump 160 is connected to the vapor chamber 121 upper the electric heating plate 120 .
[0018] A steam control device is consisted of the pressure sensor 140 , the control board 150 and the pump 160 , in ironing, if forceful steam is needed, the user can press the cover 112 disposed in the opening of the handle 111 by palm. The cover 112 is pressed downwardly to press the pressure sensor 140 , and the pressure sensor 140 will transmit a pressure signal of the pressing by the user to the control board 150 , then the pump 160 is controlled by the control board 150 according to the strength and the continue time of the signal, and input the water in the container 170 into the vapor chamber 121 of the electric heating plate 120 proportionally so as to generate steam and spray the steam out from the outlet 122 of the electric heating plate 120 .
[0019] The control board 150 provides control signal to the pump 160 , for example, by frequency modulation; thus the control board 150 will provide a strengthened control signal frequency to the pump 160 if the pressure signal is strengthened suddenly, so that the steam amount can be added in a short time accordingly to get forceful steam.
Embodiment 2
[0020] As is shown in FIG. 2 , in this embodiment, the steam iron of the present invention is provided with an ironing station with evaporator,
[0021] The lower portion of the housing 210 is provided with an electric heating plate 220 . A power switch 230 is disposed on the handle 211 of the housing 210 . the top surface of the handle 211 is provided with an opening and a cover 212 made of flexible material is dispose on the opening. A pressure sensor 240 is disposed beneath the opening in the handle 211 . A control board 250 with microprocessor is disposed inside the housing 210 of the iron body.
[0022] A main power switch 320 , a pump 340 , a container 330 and an evaporator 350 are mounted inside the housing 310 of the iron station. The top of the container 330 is provided with an inlet 331 and the bottom of the container 330 is provided with a tube 332 which is connected to the inlet of the pump 340 . The outlet 341 of the pump 340 is connected to the inlet of the evaporator 350 . A tube 360 disposed between the iron station and the iron body contains a steam tube 213 , a power cord and a signal cord inside. The steam tube 213 connected to the outlet 351 of the evaporator 350 of the iron station and the vapor chamber 221 of the electric heating plate 220 of the iron body. The power cord provides power to the switch 230 of the iron body from the main switch 320 of the iron station. The signal cord is connected between the control board 250 of the iron body and the pump 340 of the iron station.
[0023] A steam control device is consisted of the pressure sensor 240 , control board 250 , pump 340 and evaporator 350 .
[0024] In ironing, if forceful steam is needed, the user can press the cover 212 disposed in the opening of the handle 211 by palm. The cover 212 is pressed downwardly to the pressure sensor 240 , and the pressure sensor 240 will transmit a pressure signal of the press by the user to the control board 250 , then the pump 360 is controlled by the control board 250 according to the strength and the continue time of the signal, and input the water in the container 330 to the vapor chamber 221 of the electric heating plate 220 so as to generate steam and spray the steam out from the outlet 222 of the electric heating plate 220 .
[0025] The control board 250 provides control signal to the pump 340 , for example, by frequency modulation; thus the control board 250 will provide a strengthened control signal frequency to the pump 340 if the pressure signal is strengthened suddenly, so that the working power of the pump 340 is added and more water can be pumped to the evaporator 350 from the container 330 , therefore, the steam amount can be added in a short time accordingly to get forceful steam.
Embodiment 3
[0026] In this embodiment, the steam iron of the present invention is provided with an iron station with an additional container, referring to FIG. 3 , The lower portion of the housing 410 is provided with an electric heating plate 420 . A power switch 430 is disposed on the handle 411 of the housing 410 . the top surface of the handle 411 is provided with an opening and a cover 412 made of flexible material is dispose on the opening. A pressure sensor 440 is disposed beneath the opening in the handle 411 . a control board 450 with microprocessor is disposed inside the housing 410 of the iron body.
[0027] A main power switch 520 , a pump 540 , a container 530 are mounted inside the housing 510 of the iron station. The top of the container 530 is provided with an inlet 531 ; and the bottom of the container 530 is provided with a tube 532 which is connected to the inlet of the pump 540 . A tube 360 disposed between the iron station and the iron body contains a water tube 413 , a power cord and a signal cord inside. The water tube 413 connected the outlet 541 of pump 540 of the iron station with the vapor chamber 421 of the electric heating plate 420 of the electric heating plate 420 of the iron body. The power cord provides power to the power switch 430 of the iron body from the main power switch 520 of the iron station. The control signal from the 450 is transmit to the pump 540 of the iron station by the signal cord.
[0028] A steam control device is consisted of the pressure sensor 440 , control board 450 and pump 540 .
[0029] In ironing, if forceful steam is needed, the user can press the cover 412 disposed in the opening of the handle 411 by palm, then the cover 412 is pressed downwardly to the pressure sensor 440 , and the pressure sensor 440 will transmit a pressure signal of the press by the user to the control board 450 , the pump 540 is controlled by the control board 450 according to the strength and the continue time of the signal, and input the water in the container 530 to the vapor chamber 421 of the electric heating plate 420 so as to generate steam and spray the steam out from the outlet 422 of the electric heating plate 420 .
[0030] The control board 450 provides control signal to the pump 540 , voltage or current control can be used besides the frequency control used in the afore two embodiment, for example, voltage control is used to control the pump, then the control board 450 will provide a strengthened voltage control signal to the pump 540 if the pressure signal is strengthened suddenly, so that the working power of the pump 540 is added and more water can be pumped to the evaporator 350 from the container 530 , therefore the steam amount can be added in a short time to get forceful steam.
Embodiment 4
[0031] As is shown in FIG. 4 , in this embodiment, the steam iron of the present invention is provided with an boiler ironing station,
[0032] The lower portion of the housing 610 is provided with an electric heating plate 620 . A power switch 630 is disposed on the handle 611 of the housing 610 . The top surface of the handle 611 is provided with an opening and a cover 612 made of flexible material is dispose on the opening. A pressure sensor 640 is disposed beneath the opening in the handle 611 . a control board 650 with microprocessor is disposed inside the housing 610 of the iron body.
[0033] A main switch 720 , an electromagnetic valve 740 and a boiler are mounted inside the housing 710 of the iron station. The top of the boiler 730 is provided with an inlet 731 ; and a steam outlet tube 732 provided on the top of the boiler is connected to steam inlet of the electromagnetic valve 740 . A tube 760 disposed between the iron station and the iron body contains a steam tube 613 , a power cord and a signal cord inside. The steam tube 613 connected the steam outlet tube 741 of the electromagnetic valve 740 of the iron station with the vapor chamber 621 of the electric heating plate 620 of the iron body. The power cord provides power to the switch 630 of the iron body from the main switch 720 of the iron station. And the signal cord transmit the control signal from the control board 650 of the iron body to the electromagnetic valve 740 of the iron station.
[0034] A steam control device is consisted by the pressure sensor 640 , control board 650 and the electromagnetic valve 740 .
[0035] In ironing, if forceful steam is needed, the user can press the cover 612 disposed in the opening of the handle 611 by palm. Then the cover 612 is pressed downwardly to the pressure sensor 640 , and the pressure sensor 640 will transmit a pressure signal of the pressing by the user to the control board 650 , the electromagnetic valve 740 is controlled by the control board 650 according to the strength and the continue time of the signal, and input the steam in the boiler 730 to the vapor chamber 621 of the electric heating plate 620 to secondly heated so as to generate forceful steam, and the forceful steam is sprayed out from the outlet 622 of the electric heating plate 620 .
[0036] The control board 650 provides voltage control signal to the electromagnetic valve 740 , and the control board 650 will provide a strengthened voltage control signal to the electromagnetic valve 740 correspondingly if the pressure signal from the pressure sensor 640 is strengthened suddenly, so that more steam can be allowed through the electromagnetic valve 740 to the vapor chamber 621 of the electric heating plate 620 from the boiler 730 , therefore the steam amount can be added in a short time to get forceful steam.
[0037] The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including configurations ways of the recessed portions and materials and/or designs of the attaching structures. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments. | The present invention discloses a steam iron comprising a housing with a handle, a water container, a steam control device and a vapor chamber provided with an electric heating plate, wherein the steam control device comprising a pressure sensor mounted on the handle of said housing, a control board with a microprocessor and an execution unit for providing the water into said chamber or providing the vapor generated by a evaporator into said chamber for secondly heated; the execution unit is controlled by the control board by the pressure signal provided by said pressure sensor. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application No. U.S. Ser. No. 14/946,203, filed Nov. 19, 2015, which is a continuation of U.S. patent application No. U.S. Ser. No. 14/635,573, filed Mar. 2, 2015, now U.S. Pat. No. 9,233,211, which is a continuation of U.S. patent application Ser. No. 13/919,251, filed Jun. 17, 2013, now U.S. Pat. No. 9,011,391, which is a divisional of U.S. patent application Ser. No. 13/040,198, filed Mar. 3, 2011, now U.S. Pat. No. 8,512,297, which is a continuation of U.S. patent application Ser. No. 11/483,546, filed Jul. 11, 2006, now U.S. Pat. No. 7,918,833, which is a continuation of U.S. patent application Ser. No. 10/790,225, filed Mar. 2, 2004, which claims priority to GB 0304822.0 filed Mar. 3, 2003, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to pen-type injectors, that is, to injectors of the kind that provide for administration by injection of medicinal products from a multidose cartridge. In particular, the present invention relates to such injectors where a user may set the dose.
[0003] Such injectors have application where regular injection by persons without formal medical training occurs. This is increasingly common amongst those having diabetes where self-treatment enables such persons to conduct effective management of their diabetes.
[0004] These circumstances set a number of requirements for pen-type injectors of this kind. The injector must be robust in construction, yet easy to use both in terms of the manipulation of the parts and understanding by a user of its operation. In the case of those with diabetes, many users will be physically infirm and may also have impaired vision. Where the injector is to be disposable rather than reusable, the injector should be cheap to manufacture and easy to dispose of (preferably being suitable for recycling).
SUMMARY
[0005] It is an advantage of the present invention that an improved pen-type injector is provided.
[0006] According to a first aspect of the present invention, a pen-type injector comprises
a housing; a piston rod adapted to operate through housing; a dose dial sleeve located between the housing and the piston rod, the dose dial sleeve having a helical thread of first lead; a drive sleeve located between the dose dial sleeve and the piston rod, the drive sleeve having a helical groove of second lead; characterized in that the first lead of the helical thread and the second lead of the helical groove are the same.
[0012] Preferably, the piston rod has a first threaded portion at a first end and a second threaded portion at a second end;
an insert or radially inwardly extending flange is located in the housing and through which the first threaded portion of the piston rod may rotate; the dose dial sleeve being rotatable with respect to the housing and the insert; the drive sleeve being releasably connected to the dose dial sleeve and connected to the piston rod for rotation with respect thereto along the second threaded portion of the piston rod; a button is located on the dose dial sleeve and rotatable with respect to the does dial sleeve; and clutch means are provided which upon depression of the button permit rotation between the dose dial sleeve and the drive sleeve.
[0018] Preferably, the injector further comprises a nut which is rotatable with respect to the drive sleeve and axially displaceable but not rotatable with respect to the housing.
[0019] More preferably, the drive sleeve is provided at a first end with first and second flanges with an intermediate thread between the first and second flanges, the nut being disposed between the first and second flanges and keyed to the housing by spline means. Additionally, a first radial stop may be provided on a second face of the nut and a second radial stop may be provided on a first face of the second flange.
[0020] Preferably, the first thread of the piston rod is oppositely disposed to the second thread of the piston rod.
[0021] Preferably, a second end of the clutch is provided with a plurality of dog teeth adapted to engage with a second end of the dose dial sleeve.
[0022] Preferably, the pen-type injector further includes clicker means disposed between the clutch means and spline means provided on the housing.
[0023] More preferably, the clicker means comprises a sleeve provided at a first end with a helically extending arm, a free end of the arm having a toothed member, and at a second end with a plurality of circumferentially directed saw teeth adapted to engage a corresponding plurality of circumferentially saw teeth provided on the clutch means.
[0024] Alternatively, the clicker means comprises a sleeve provided at a first end with at least one helically extending arm and at least one spring member, a free end of the arm having a toothed member, and at a second end with a plurality of circumferentially directed saw teeth adapted to engage a corresponding plurality of circumferentially directed saw teeth provided on the clutch means.
[0025] Preferably, the main housing is provided with a plurality of maximum dose stops adapted to be abutted by a radial stop provided on the dose dial sleeve. More preferably, at least one of the maximum dose stops comprises a radial stop located between a helical rib and spline means provided at a second end of the housing. Alternatively, at least one of the maximum dose stops comprises a part of a raised window portion provided at a second end of the housing.
[0026] Preferably, the dose dial sleeve is provided with a plurality of radially extending members adapted to abut a corresponding plurality of radial stops provided at a second end of the housing.
BRIEF DESCRIPTION OF THE FIGURES
[0027] The invention will now be described with reference to the accompanying drawings in which:
[0028] FIG. 1 shows a sectional view of a pen-type injector in accordance with the present invention in a first, cartridge full, position;
[0029] FIG. 2 shows a sectional view of the pen-type injector of FIG. 1 in a second, maximum first dose dialed, position;
[0030] FIG. 3 shows a sectional view of the pen-type injector of FIG. 1 in a third, first maximum first dose dispensed, position;
[0031] FIG. 4 shows a sectional view of the pen-type injector of FIG. 1 in a fourth, final dose dialed, position;
[0032] FIG. 5 shows a sectional view of the pen-type injector of FIG. 1 in a fifth, final dose dispensed, position;
[0033] FIG. 6 shows a cut-away view of a first detail of the pen-type injector of FIG. 1 ;
[0034] FIG. 7 shows a partially cut-away view of a second detail of the pen-type injector of FIG. 1 ;
[0035] FIG. 8 shows a partially cut-away view of a third detail of the pen-type injector of FIG. 1 ;
[0036] FIG. 9 shows the relative movement of parts of the pen-type injector shown in FIG. 1 during dialing up of a dose;
[0037] FIG. 10 shows the relative movement of parts of the pen-type injector shown in FIG. 1 during dialing down of a dose;
[0038] FIG. 11 shows the relative movement of parts of the pen-type injector shown in FIG. 1 during dispensing of a dose;
[0039] FIG. 12 shows a partially cut-away view of the pen-type injector of FIG. 1 in the second, maximum first dose dialed, position;
[0040] FIG. 13 shows a partially cut-away view of the pen-type injector of FIG. 1 in the fourth, final dose dialed, position;
[0041] FIG. 14 shows a partially cut-away view of the pen-type injector of FIG. 1 in one of the first, third or fifth positions;
[0042] FIG. 15 shows a cut-away view of a first part of a main housing of the pen-type injector of FIG. 1 ; and
[0043] FIG. 16 shows a cut-away view of a second part of the main housing of the pen-type injector of FIG. 1 .
DETAILED DESCRIPTION
[0044] Referring first to FIGS. 1 to 5 , there may be seen a pen-type injector in accordance with the present invention in a number of positions.
[0045] The pen-type injector comprises a housing having a first cartridge retaining part 2 , and second main housing part 4 . A first end of the cartridge retaining means 2 and a second end of the main housing 4 are secured together by retaining features 6 . In the illustrated embodiment, the cartridge retaining means 2 is secured within the second end of the main housing 4 .
[0046] A cartridge 8 from which a number of doses of medicinal product may be dispensed is provided in the cartridge retaining part 2 . A piston 10 is retained in a first end of the cartridge 8 .
[0047] A removable cap 12 is releasably retained over a second end of the cartridge retaining part 2 . In use the removable cap 12 can be replaced by a user with a suitable needle unit (not shown). A replaceable cap 14 is used to cover the cartridge retaining part 2 extending from the main housing 4 . Preferably, the outer dimensions of the replaceable cap 14 are similar or identical to the outer dimensions of the main housing 4 to provide the impression of a unitary whole when the replaceable cap 14 is in position covering the cartridge retaining part 2 .
[0048] In the illustrated embodiment, an insert 16 is provided at a first end of the main housing 4 . The insert 16 is secured against rotational or longitudinal motion. The insert 16 is provided with a threaded circular opening 18 extending therethrough. Alternatively, the insert may be formed integrally with the main housing 4 the form of a radially inwardly directed flange having an internal thread.
[0049] A first thread 19 extends from a first end of a piston rod 20 . The piston rod 20 is of generally circular section. The first end of the piston rod 20 extends through the threaded opening 18 in the insert 16 . A pressure foot 22 is located at the first end of the piston rod 20 . The pressure foot 22 is disposed to abut a second end of the cartridge piston 10 . A second thread 24 extends from a second end of the piston rod 20 . In the illustrated embodiment the second thread 24 comprises a series of part threads rather than a complete thread. The illustrated embodiment is easier to manufacture and helps reduce the overall force required for a user to cause medicinal product to be dispensed.
[0050] The first thread 19 and the second thread 24 are oppositely disposed. The second end of the piston rod 20 is provided with a receiving recess 26 .
[0051] A drive sleeve 30 extends about the piston rod 20 . The drive sleeve 30 is generally cylindrical. The drive sleeve 30 is provided at a first end with a first radially extending flange 32 . A second radially extending flange 34 is provided spaced a distance along the drive sleeve 30 from the first flange 32 . An intermediate thread 36 is provided on an outer part of the drive sleeve 30 extending between the first flange 32 and the second flange 34 . A helical groove 38 extends along the internal surface of the drive sleeve 30 . The second thread 24 of the piston rod 20 is adapted to work within the helical groove 38 .
[0052] A first end of the first flange 32 is adapted to conform to a second side of the insert 16 .
[0053] A nut 40 is located between the drive sleeve 30 and the main housing 2 , disposed between the first flange 32 and the second flange 34 . In the illustrated embodiment the nut 40 is a half-nut. This assists in the assembly of the injector. The nut 40 has an internal thread matching the intermediate thread 36 . The outer surface of the nut 40 and an internal surface of the main housing 4 are keyed together by splines 42 (see FIGS. 10, 11, 15 and 16 ) to prevent relative rotation between the nut 40 and the main housing 4 , while allowing relative longitudinal movement therebetween.
[0054] A shoulder 37 is formed between a second end of the drive sleeve 30 and an extension 38 provided at the second end of the drive sleeve 30 . The extension 38 has reduced inner and outer diameters in comparison to the remainder of the drive sleeve 30 . A second end of the extension 38 is provided with a radially outwardly directed flange 39 .
[0055] A clicker 50 and a clutch 60 are disposed about the drive sleeve 30 , between the drive sleeve 30 and a dose dial sleeve 70 (to be described below).
[0056] The clicker 50 is located adjacent the second flange 34 of the drive sleeve 30 . The clicker 50 is generally cylindrical and is provided at a first end with a flexible helically extending arm 52 (shown most clearly in FIG. 6 ). A free end of the arm 52 is provided with a radially directed toothed member 54 . A second end of the clicker 50 is provided with a series of circumferentially directed saw teeth 56 (of FIG. 7 ). Each saw tooth comprises a longitudinally directed surface and an inclined surface.
[0057] In an alternative embodiment (not shown) the clicker means further includes at least one spring member. The at least one spring member assists in the resetting of the clutch means 60 following dispense.
[0058] The clutch means 60 is located adjacent the second end of the drive sleeve 30 . The clutch means 60 is generally cylindrical and is provided at a first end with a series of circumferentially directed saw teeth 66 (see FIG. 7 ). Each saw tooth comprises a longitudinally directed surface and an inclined surface. Towards the second end 64 of the clutch means 60 there is located a radially inwardly directed flange 62 . The flange 62 of the clutch means 60 is disposed between the shoulder 37 of the drive sleeve 30 and the radially outwardly directed flange 39 of the extension 38 . The second end of the clutch means 60 is provided with a plurality of dog teeth 65 ( FIG. 8 ). The clutch 60 is keyed to the drive sleeve 30 by way of splines (not shown) to prevent relative rotation between the clutch 60 and the drive sleeve 30 .
[0059] In the illustrated embodiment, the clicker 50 and the clutch 60 each extend approximately half the length of the drive sleeve 30 . However, it will be understood that other arrangements regarding the relative lengths of these parts are possible.
[0060] The clicker 50 and the clutch means 60 are normally engaged, that is as shown in FIG. 7 .
[0061] A dose dial sleeve 70 is provided outside of the clicker 50 and clutch means 60 and radially inward of the main housing 4 . A helical groove 74 is provided about an outer surface of the dose dial sleeve 70 .
[0062] The main housing 4 is provided with a window 44 through which a part of the outer surface of the dose dial sleeve may be seen. The main housing 4 is further provided with a helical rib 46 , adapted to be seated in the helical groove 74 on the outer surface of the dose dial sleeve 70 . The helical rib 46 extends for a single sweep of the inner surface of the main housing 4 . A first stop 100 is provided between the splines 42 and the helical rib 46 ( FIG. 15 ). A second stop 102 , disposed at an angle of 180° to the first stop 100 is formed by a frame surrounding the window 44 in the main housing 4 ( FIG. 16 ).
[0063] Conveniently, a visual indication of the dose that may be dialed, for example reference numerals (not shown). is provided on the outer surface of the dose dial sleeve 70 . The Window 44 conveniently only allows to be viewed a visual indication of the dose currently dialed.
[0064] A second end of the dose dial sleeve 70 is provided with an inwardly directed flange in the form of number of radially extending members 75 . A dose dial grip 76 is disposed about an outer surface of the second end of the dose dial sleeve 70 . An outer diameter of the dose dial grip 76 preferably corresponds to the outer diameter of the main housing 4 . The dose dial grip 76 is secured to the dose dial sleeve 70 to prevent relative movement therebetween. The dose dial grip 76 is provided with a central opening 78 . An annular recess 80 located in the second end of the dose dial grip 76 extends around the opening 78 .
[0065] A button 82 of generally ‘T’ section is provided at a second end of the pen-type injector. A stem 84 of the button 82 may extend through the opening 78 in the dose dial grip 76 , through the inner diameter of the extension 38 of the drive sleeve 30 and into the receiving recess 26 of the piston rod 20 . The stem 84 is retained for limited axial movement in the drive sleeve 30 and against rotation with respect thereto. A head 85 of the button 82 is generally circular. A skirt 86 depends from a periphery of the head 85 . The skirt 86 is adapted to be seated in the annular recess 80 of the dose dial grip 76 .
[0066] Operation of the pen-type injector in accordance with the present invention will now be described. In FIGS. 9, 10 and 11 arrows A, B. C, D, E, F and G represent the respective movements of the button 82 , the dose dial grip 76 , the dose dial sleeve 70 , the drive sleeve 30 , the clutch means 60 , the clicker 50 and the nut 40 .
[0067] To dial a dose ( FIG. 9 ) a user rotates the dose dial grip 76 (arrow A). With the clicker 50 and clutch means 60 engaged, the drive sleeve 30 , the clicker 50 , the clutch means 60 and the dose dial sleeve 70 rotate with the dose dial grip 76 .
[0068] Audible and tactile feedback of the dose being dialed is provided by the clicker 50 and the clutch means 60 . Torque is transmitted through the saw teeth 56 , 66 between the clicker 50 and the clutch means 60 . The flexible arm 52 deforms and drags the toothed member 54 over the splines 42 to produce a click. Preferably, the splines 42 are dispose such that each click corresponds to a unit dose.
[0069] The helical groove 74 on the dose dial sleeve 70 and the helical groove 38 in the drive sleeve 30 have the same lead. This allows the dose dial sleeve 70 (arrow C) to extend from the main housing 4 and the drive sleeve 30 (arrow D) to climb the piston rod 20 at the same rate. At the limit of travel, a radial stop 104 on the dose dial sleeve 70 engages either the first stop 100 or the second stop 102 provided on the main housing 4 to prevent further movement. Rotation of the piston rod 20 is prevented due to the opposing directions of the overhauled and driven threads on the piston rod 20 .
[0070] The nut 40 , keyed to the main housing 4 , is advanced along the intermediate thread 36 by the rotation of the drive sleeve 30 (arrow D). When the final dose dispensed position ( FIGS. 4, 5 and 13 ) is reached, a radial stop 106 formed on a second surface of the nut 40 abuts a radial stop 108 on a first surface of the second flange 34 of the drive sleeve 30 preventing both the nut 40 and the drive sleeve 30 from rotating further.
[0071] In an alternative embodiment (not shown) a first surface of the nut 40 is provided with a radial stop for abutment with a radial stop provided on a second surface of the first flange 32 . This aids location of the nut 40 at the cartridge full position during assembly of the pen-type injector.
[0072] Should a user inadvertently dial beyond the desired dosage, the pen-type injector allows the dosage to be dialed down without dispense of medicinal product from the cartridge ( FIG. 10 ). The dose dial grip 76 is counter rotated. This causes the system to act in reverse. The flexible arm 52 now acts as a ratchet preventing the clicker from rotating. The torque transmitted through the clutch means 60 causes the saw teeth 56 , 66 to ride over one another to create the clicks corresponding to dialed dose reduction. Preferably the saw teeth 56 , 66 are so disposed that the circumferential extent of each saw tooth corresponds to a unit dose.
[0073] When the desired dose has been dialed, the user may then dispense this dose by depressing the button 82 ( FIG. 11 ). This displaces the clutch means 60 axially with respect to the dose dial sleeve 70 causing the dog teeth 65 to disengage. However the clutch means 60 remains keyed in rotation to the drive sleeve 30 . The dose dial sleeve 70 and associated dose dial grip 76 are now free to rotate (guided by the helical rib 46 located in helical groove 74 ).
[0074] The axial movement deforms the flexible arm 52 of the clicker 50 to ensure the saw teeth 56 , 66 cannot be overhauled during dispense. This prevents the drive sleeve 30 from rotating with respect to the main housing 4 though it is still free to move axially with respect thereto. This deformation is subsequently used to urge the clicker 50 , and the clutch 60 , back along the drive sleeve 30 to restore the connection between the clutch 60 and the dose dial sleeve 70 when pressure is removed from the button 82 .
[0075] The longitudinal axial movement of the drive sleeve 30 causes the piston rod 20 to rotate though the opening 18 in the insert 16 , thereby to advance the piston 10 in the cartridge 8 . Once the dialed dose has been dispensed, the dose dial sleeve 70 is prevented from further rotation by contact of a plurality of members 110 ( FIG. 14 ) extending from the dose dial grip 76 with a corresponding plurality of stops 112 formed in the main housing 4 ( FIGS. 15 and 16 ). In the illustrated embodiment, the members 110 extend axially from the dose dial grip 76 and have an inclined end surface. The zero dose position is determined by the abutment of one of the axially extending edges of the members 110 with a corresponding stop 112 . | The present invention relates to injectors, such as pen-type injectors, that provide for administration of medicinal products from a multidose-cartridge and permit a user to set the delivery dose. The injector may include a housing, a piston rod adapted to operate through the housing, a dose dial sleeve located between the housing and the piston rod, and a drive sleeve located between the dose dial sleeve and the piston rod. The dose dial sleeve may have a helical thread of first lead and the drive sleeve may have a helical groove of second lead. The first lead of the helical thread and the second lead of the helical groove may be the same. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to ice makers, and more particularly, to an improved drive and control module for ice makers used in refrigerators and the like.
BACKGROUND OF THE INVENTION
[0002] Ice makers are known for use in refrigerator/freezers, such as shown in U.S. Pat. No. 5,261,248, which include a mold in which water is frozen to form cube or other shaped ice bodies and a rotatable ice ejector having a plurality of radial ice ejector arms. A drive module is provided for rotating a shaft of the ejector, which includes a drive motor that drives the periphery of a gear wheel having an axial sleeve that receives and drives a vertical cam shaft, the rotation of which in turn rotates the ejector during an ejection cycle, as well as control rotation of an ice level sensing arm.
[0003] During the ejection cycle, ice bodies sometimes can become lodged between the ejector arms and the strippers so as to impede or interrupt rotation of the ejector. In an effort to overcome such obstructions, drive motors with increased torque have been employed for the ice ejector. Because the drive train between the drive motor and the ejector shaft include plastic parts, including the gear wheel and the vertical cam shaft, when rotation of the ice ejector shaft is interrupted by a jammed ice body, the larger powered drive motor can cause such high torque between the gear wheel and vertical cam shaft that fracture or breakage of the plastic drive components can result.
[0004] A further problem with such ice makers concerns the water fill cycle of the ice maker. To control operation of the water refill cycle, an electrical water fill contact of the control module will periodically contact a relatively moveable circumferential track of a face cam circuit mounted on the gear wheel. In order to selectively adjust the fill cycle time (and hence the water depth in the ice maker mold) the contact is radially positionable by means of an adjustment screw and the start up location is determined by an angled groove in the rotatable circuit track.
[0005] To establish the proper fill level, the adjustment screw for the water fill contact must be precisely set. This typically requires a multiplicity of assembly inspections and a water fill check procedure. Furthermore, after the contact position has been properly determined, shipping and handling of the ice maker, as well as subsequent installation in a refrigerator/freezer, can alter the radial position of the contact and hence cause unwanted changes in the water refill time. Moreover, since the contact adjustment screw can protrude from the device, it can impede packaging and be subject to breakage or damage during handling of the ice maker. Thus, while heretofore the adjustable positioning of the water refill contact relative to the gear contact track was intended to enable a precise fill level in the mold, it has resulted in uncertainty and water fill cycle problems in the field.
OBJECTS AND SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide an ice maker having a drive control module that is simpler in design and more reliable in operation.
[0007] Another object is to provide an ice maker as characterized above which has an ice body ejector drive that is less susceptible to fracture or failure in the event of an ice cube jam during an ejection cycle.
[0008] A further object is to provide an ice maker of the foregoing type having a control module that can be assembled with the ice maker to precisely control the water fill cycle without factory testing.
[0009] Still another object is to provide an ice maker of the above kind that has a control module in which the water fill cycle is substantially unaffected by alterations in the radial position of a water fill control relative to a rotatable face cam circuit track of the control. Yet a further object is to provide such an ice maker in which the control module has a water fill contact the position of which is less susceptible to alternation during shipping and handling of the ice maker, or during installation in a refrigerator/freezer.
[0010] Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a fragmentary perspective of a refrigerator ice maker in accordance with the invention;
[0012] FIG. 2 is an enlarged fragmentary vertical section of the illustrated ice maker taken in the plane of line 2 - 2 in FIG. 1 , with certain parts removed for clarity;
[0013] FIG. 3 is an enlarged exploded perspective of one embodiment of an ice ejector drive coupling in accordance with the invention;
[0014] FIG. 3 a is an enlarged fragmentary perspective of a drive sleeve of the gear wheel shown in FIG. 3 ;
[0015] FIG. 4 is a sectioned perspective of the drive coupling shown in FIG. 3 in assembled condition;
[0016] FIG. 5 is an exploded perspective of an alternative embodiment of ice ejector drive coupling in accordance with the invention;
[0017] FIG. 6 is an enlarged fragmentary perspective of a drive sleeve of the gear wheel shown in FIG. 5 ;
[0018] FIG. 7 is a side elevational view of a face cam electrical circuit of the control of the illustrated ice maker;
[0019] FIG. 8 is an enlarged fragmentary vertical section and side elevational view of a side plate of the control module of the illustrated ice maker, also taken in the plane of line 2 - 2 in FIG. 1 , with certain parts removed for illustrating the electrical control;
[0020] FIG. 9 is an enlarged side elevational view of the water fill contact shown in FIG. 8 ; and
[0021] FIGS. 10-13 are enlarged fragmentary sections of the water fill contact and its mounting in the illustrated control, taken in the planes of line 10 - 10 , 11 - 11 , 12 - 12 and 13 - 13 , respectively in FIG. 9 .
[0022] While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof has 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 forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring now more particularly to FIG. 1 of the drawings, there is shown an illustrative ice maker 10 in accordance with the invention. It will be understood that the basic construction and operation of the ice maker is disclosed in the afore-referenced U.S. Pat. No. 5,261,248, the disclosure of which is incorporated herein by reference and need not be repeated in detail.
[0024] The illustrated ice maker, as depicted in FIG. 1 , includes a mold 11 in which ice bodies are formed from water delivered to the mold 11 by a fill dispenser 12 fluidically connected to a solenoid valve 14 by a water supply line 15 . The solenoid valve 14 in turn is connectable to a suitable pressurized water supply. The ice maker 10 further includes a control module 18 disposed at the front of the mold 11 and arranged to operate an ice ejector 20 , which upon completion of a freezing cycle of water in the mold 11 , removes the ice bodies from the mold. The ice ejector 20 has a plurality of radial ejector arms 21 that rotatably engage and carry ice out of the mold 11 , which is stripped by strippers 22 and drop into an adjacent collecting bin 24 . A pivotably mounted ice level sensing arm 25 extends downwardly above the collecting bin 24 to sense the level of ice bodies in the bin 24 . The illustrated mold 20 includes a plurality of partition walls 28 extending transversely across the mold 20 to define a plurality of cavities in which a corresponding plurality of ice bodies are formed. The partition walls 28 may be formed with appropriate recesses 29 communicating between the cavities to permit the flow of water from cavity to cavity during a water fill cycle operation. It will be understood that removal of the ice bodies from the mold cavities may be facilitated by heating the underside of the mold 11 to free the ice bodies for ejection from the cavities by the ejector 20 .
[0025] The control module 18 includes a motor 30 having an output pinion 31 that drives the periphery of a relatively larger gear wheel 32 mounted on a front side of a side plate 34 of the control module 18 . The gear wheel 32 in turn drives a vertical cam shaft 35 , which in turn drives a central shaft 36 of the ice ejector 20 . The vertical cam shaft 35 in this case has a D-shaped opening 37 that receives the ice ejector shaft 36 for rotation therewith. The vertical cam shaft 35 carries a cam 38 , referred to in the art as a vertical cam, having a cam surface that cooperates with a lever mechanism 39 for controlling positioning of the ice level sensing arm 25 in a conventional manner in response to rotation of the cam 38 . The lever mechanism 39 in this case includes a lever arm 40 having a cam follower surface engageable with the cam 38 and being pivotal in response rotation of the cam shaft 35 for pivoting an actuator 41 to which the sensing arm 35 is fixed.
[0026] To reduce manufacturing costs, it is known to make various parts of the ice maker control module 18 of molded plastic, including the gear wheel 32 , vertical cam shaft 35 , level arm 40 , and actuator 41 . As indicated previously, in the event of an ice jam between the ejector arms 21 and the strippers 22 during an ice ejection cycle, large stresses can be imparted on the drive components by the drive motor 30 that can cause fracture or breakage of the plastic drive components, including particularly the gear wheel and/or cam shaft.
[0027] In accordance with one aspect of the invention, the drive gear and vertical cam shaft have a splined connection which more effectively distributes driving forces and substantially reduces the risk of fracture or part failure. In the illustrated embodiment, the gear wheel 32 has a central rearwardly extending sleeve 45 formed with an enlarged diameter cylindrical counter bore section 46 which defines an annular locating ledge 47 , and which communicates with a smaller diameter bore 48 that extends through a forward side of the gear wheel 32 . The vertical cam shaft 35 has a forward end that includes a cylindrical section 50 that is positionable within the cylindrical counter bore section 48 of the gear wheel-sleeve 45 and projecting locking legs 51 that extend forwardly through the central smaller diameter bore 48 of the gear wheel 32 . The locking legs in this case have tapered end surfaces 52 for camming the legs 51 together during forceful insertion through the gear wheel bore 48 and outwardly directed locking ledges 54 for lockingly engaging a forward side of the gear wheel 32 .
[0028] In keeping with the invention, the cylindrical counter-bore section 46 of the gear wheel sleeve 45 and the cylindrical section 50 of the vertical cam shaft 35 are formed with longitudinally extending, circumferentially spaced splines 55 , 56 , respectively which are adapted for inter fitting, radial force transmitting engagement with each other. The splines 55 , 56 in this case each have complimentary general V-shapes with peaks 58 and valleys 59 that may be rounded or squared. It will be understood that the splines 55 , 56 of the gear wheel 32 and cam shaft 35 can be positioned longitudinally into assembled relation to each other for providing radial force transmission as an incident to operation of the drive motor 30 and rotation of the gear wheel 32 . Indeed, the spline connection has been found to permit transmission of substantially greater torque, up to 30% or more, through the drive train without failure of plastic drive components. While the theory of operation is entirely understood, it is believed that the increased surface area attributed to the engaging splines 55 , 56 minimizes the magnitude of transmitted stresses between the gear wheel and vertical cam shaft that occur during high torquing, such as during temporary jamming of ice body between the mold and ejector arms during an ejection cycle.
[0029] It will be understood that while in the illustrated embodiment the gear wheel 32 drives the cam shaft 35 , which in turn is mechanically coupled to the ejector shaft 36 alternatively, the cam shaft 35 could be an integrated part of the ejector shaft 36 . For purposes herein, reference to a shaft section being operatively coupled to the ejector shaft is intended to mean a shaft section that is mechanically coupled to the ejector shaft or integral therewith.
[0030] An alternative embodiment of drive connection between the gear wheel 32 and vertical cam shaft 35 for improving torque transmission through the plastic drive components of the drive module 18 is shown in FIGS. 5 and 6 , wherein items similar to those described above have been given similar reference numerals. In this embodiment, the vertical cam shaft 35 again has a pair of locking legs 51 that are positionable through a central bore of the gear wheel 32 into locking engagement with a forward side thereof. For transmitting torque between the gear wheel 32 and vertical cam shaft 35 , in this case the cylindrical drive sleeve 50 of the gear wheel 32 is formed with a pair of diametrically opposed rearwardly extending drive lugs 60 at its end that are positionable into inter fitting relation with opposed recesses in an axial end face of the cam shaft 35 adjacent opposite sides of the locking legs 51 . Upon assembly of the gear wheel 32 and cam shaft 35 , it can be seen that the drive lugs 60 will transmit rotational torque to the cam shaft 32 as an incident to operation of the drive motor 30 .
[0031] In carrying out this embodiment of the invention, an annular metal collar 61 is positionable in tight fitting relation about the cylindrical drive sleeve 50 of the gear wheel 32 . The metal collar 61 , which preferably is made of steel and press fit onto the gear wheel sleeve 50 , unexpectedly has been found to enhance torque transmission between the gear wheel 32 and vertical cam shaft 35 without fracture or cracking of the plastic drive components. The metal collar 61 is believed to reinforce the drive connection and thereby permit substantially greater torque transmission without part failure.
[0032] In accordance with a further aspect of the invention, the plastic drive components of the drive module 18 , and particularly the gear wheel 32 and vertical cam shaft 35 , are formed of a stress resistant material that further enhances torque transmission through the drive module to the ejector 20 without cracking or other failure of the plastic parts. To this end, in the illustrated embodiment, the plastic drive components are made from a polyamide resin. The resin can be any suitable polyamide resin, but preferably the resin is a nylon resin. Suitable nylon resins include, but are not limited to, nylon 6 (e.g., polycaprolactam), nylon 6/6 (e.g., poly(hexamethylene adipamide)), and nylon 6/12, (e.g., poly(hexamethylene dodecanediamide)), copolymers thereof, and mixtures thereof. Preferably, the polyamide resin is nylon 6/6 (e.g., poly(hexamethylene adipamide)), which typically is made via the polycondensation of hexamethylene diamine and adipic acid. In order to further increase the mechanical strength of the polyamide resin from which the drive components are made, the polyamide resin preferably further comprises a reinforcing filler, such as glass fibers. The polyamide resin can comprise any suitable amount of reinforcing filler. For example, when the reinforcing filler is a glass fiber, the polyamide resin preferably comprises about 20% to about 30% (e.g., about 25%) by weight glass fiber based on the total weight of the resin and reinforcing filler. Suitable commercially available resin/filler blends include, but are not limited to, the nylon 6/6 resins marketed by DuPont under the trademark Zytel®, such as Zytel® FR50HF NC010 nylon 6/6 resin, and the nylon 6/6 resins marketed by Solutia under the trademark VYDYNE®, such as VYDYNE® 909 nylon 6/6 resin.
[0033] For controlling operation of electrically responsive functions of the ice maker 10 , a face cam circuit 65 is mounted on a rear side of the gear wheel 32 of the control module 18 . As known in the art, the face cam circuit 65 , as depicted in FIG. 7 , may define a plurality arcuate face cam circuit tracks of electrically conductive material. Rotation of the gear wheel 32 and face cam surface 65 in the counter-clockwise direction from a zero degree home position will sequentially move the arcuate tracks into electrical contact in relation with respective contacts mounted on the side plate 34 of the module 18 at radial positions corresponding to face cam circuit tracks for operating the electrically activated functions of the ice maker.
[0034] The water fill cycle of the illustrated ice maker 10 in which water is directed to the fill dispenser 12 for filling the compartments of the mold 11 is controlled by a track A of the face cam circuit 65 . As an incident to operation of the drive motor 30 and rotation of the gear wheel 32 , track A is movable into contact with a water fill contact 66 . The face cam circuit track A in this case is the most radially outwardly disposed face cam circuit track, as is the water fill contact 66 . Heretofore, as indicated above, it has been difficult to factory install such water fill contact for filling the mold cavities to a predetermined level without selective adjustable positioning of the water fill contact and factory testing of the water fill cycle. The setting of the water fill contact also can be altered during subsequent shipping, handling, or installation of the ice maker in a refrigerator/freezer resulting in unwanted changes in the water fill level.
[0035] In accordance with a further aspect of the invention, the face cam circuit track A and water fill contact 66 can be efficiently factory installed and assembled for establishing a predetermined water fill level in the mold and the water fill level will not be affected by slight alterations in the radial position of the water fill contact 66 during handling or shipping of the ice maker 10 . The water fill contact 66 in this instance has a generally elongated configuration comprising a first elongated section 68 having a contact head 69 extending transversely in a direction parallel to the circumferential line of movement of the face cam circuit track A past the contact 66 . The contact head 69 in this case has split fingers 70 that can be biased into engaging relation with the face cam circuit track A of an incident to circumferential movement of the face cam circuit A track passed the contact. Alternatively, it will be understood that the contact 66 can be in the form of a brush similarly oriented parallel to the line circumferential movement of the face cam circuit track. The illustrated water fill contact 66 in this case has a second elongated section 70 laterally offset from the first elongated section 68 , with a transverse leg 71 at the end thereof that is electrically connected to the control circuitry for the ice maker in a known manner.
[0036] The illustrated water fill contact 66 is mounted in channel-like recesses in the rear side of the module side plate 34 with the contact head 69 extending through an opening 72 in the side plate 34 into adjacent relation to the rear side of the gear wheel 32 . The first elongated section 68 of the water fill contact 66 is mountable in a channel recess defined by parallel walls 74 , 75 and is formed with side wings 76 for biased engagement with the side walls 74 , 75 for retaining the contact 66 in fixed relation between the walls. For retaining opposite longitudinal ends of the water fill contact 66 , and hence the radial position of the contact head 69 relative to the face cam circuit track A, the side plate 34 is formed with ribs 78 , 79 between which opposite elongated ends of the water fill contact 66 abut.
[0037] During operation of the ice maker drive motor 30 and rotation of the gear wheel 32 and face cam circuit 65 from the zero position shown in FIG. 7 , the water fill contact head 66 will initially be disposed in closely spaced relation to the rear face of the gear wheel 32 . Continued circumferential advancement of the face cam circuit track A will move and an inclined ramp 82 of an initial section 84 of the face cam circuit track A into engagement with the water fill contact 66 causing the fingers 70 of the contact head 69 to ride up the ramp 82 and be forced into biased engaging relation with the initial section 84 of the face cam circuit track A. Since in the illustrated embodiment, the initial section 84 of the face cam circuit track A is not electrically connected to the control circuitry for the ice maker 10 , it serves only to raise and bias the contact head finger 70 into sliding engagement with the track.
[0038] Continued circumferential movement of the cam face circuit track A will cause a gap 85 defined between a trailing edge 86 of the initial track section 84 of the face cam circuit track A and a leading edge 88 of a further operative section 89 of the face cam circuit track A to move under the water fill contact head 66 , with the edges 86 , 88 defined by the gap 85 cleaning any foreign matter that may have accumulated on the contact fingers 70 . Engagement of the leading edge 88 of the operative section 89 of the face cam circuit track A with the water fill contact 66 will close an electrical circuit effective for energizing and opening the solenoid water supply valve 14 . The water supply valve 14 remains open during the period of circumferential movement of the operative section 89 of the face cam circuit track A passed the water fill contact 66 and is closed by de-enerization of the solenoid valve 14 when a trailing edge 90 of the operative section 89 of the face cam circuit track A circumferentially passes beyond the water fill contact 66 .
[0039] In keeping with the invention, the leading and trailing edges 88 , 90 of the operative section 89 of the face cam circuit track A are designed such that a constant predetermined refill cycle is effected notwithstanding slight alteration in the radial position of the water fill contact head 69 relative to the face cam circuit track A through longitudinal movement of the water fill contact elongated sections 68 - 70 , such as can occur by reason manufacturing tolerances in the contact retaining ribs 78 , 79 or forces to which the contact may be exposed during shipping/handling or installation of the ice maker. To this end, the leading and trailing edges of the operative section 89 of the face cam circuit track A are radially oriented with respect to the axis of rotation of the gear wheel and face cam circuit 65 such that regardless of slight changes in the radial position of the water fill contact head 69 the water fill time remains constant and unaffected. By reason of the radial orientation of the leading and trailing edges 88 , 90 of the face cam circuit track A, which can be formed with close tolerances, the water fill contact 66 and face cam circuit 65 can be factory installed efficiently without tedious and time consuming assembly and test procedures. Moreover, since the water fill time, hence the water level in the mold, is governed entirely by the location of the leading and trailing radial edges 88 , 90 of the face cam circuit track A the mold can be filled to the same predetermined water level during each fill cycle not withstanding slight alterations in radial positioning of the water fill contact during assembly or handling of the ice maker.
[0040] From the foregoing, it can be seen that an ice maker is provided that has a drive control module that is simpler in design and more reliable in operation. The module has an ice ejector drive that is less susceptible to fracture or failure in the event of an ice cube jam during the injection cycle, and the control module is operable for refilling the ice maker mold to the same predetermined level notwithstanding alterations in positioning of a water fill switching contacts due to manufacturing tolerances or forces to which the ice maker is subjected during shipping, handling or installation. | An ice maker for a refrigerator/freezer having a control module for more reliably driving a rotatable ice ejector for removing ice bodies from a mold of the ice maker and for refilling mold cavities with water. The control module has an ice ejector drive with a drive coupling that includes a gear wheel and an ejector shaft section, both made of hard plastic material, preferably a polymide resin, for transmitting higher torque to the rotary ice ejector without failure of the plastic drive components. In one embodiment, a drive sleeve on the gear wheel and a drive shaft section have a spline coupling for more effectively distributing driving forces in the drive coupling. In another embodiment, a metallic collar is tightly positioned over the gear wheel sleeve for enhancing torque transmission in the drive coupling. The control module further is operable for refilling the ice maker mold cavities to a predetermined level during each cycle of operation notwithstanding slight alterations in positioning of water fill switching contact due to manufacturing tolerances or forces to which the ice maker is subjected during shipping, handling or installation. | 5 |
RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. Ser. No. 09/694,222 filed on Oct. 23, 2000, the contents of which is incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a novel fragrance material suitable for use in lawn and garden products.
BACKGROUND OF THE INVENTION
[0003] Fragrances and odor masking materials have been added to areas such as bedding, litter boxes and stables and other areas where animal excreta and animal odors are to be found to mask or hopefully eliminate the odors created by such excretions. The fragrances or odor maskants have been applied to materials such as clays, sawdust, litter, and wood shavings.
[0004] One of the more popular materials used for litters is cedar, because it is a natural material which means that animals typically do not have an aversion to using a bedding material or litter containing the scent. In addition, cedar has a pleasant odor and its ability to mask undesirable odors is well known. However, cedar is a desirable species and the removal of these trees to incorporate into sawdust for bedding and litter creates an undesirable environmental impact. Cedar is also a commercially important wood specie and is therefore relatively expensive.
[0005] There is a continuing need to provide natural materials that provide a pleasant odor and has the ability to mask odors which also does not cause an undesirable environmental impact.
SUMMARY OF THE INVENTION
[0006] The present invention provides a composition suitable for use in an animal litter product comprising an odor-inhibiting quantity of Juniperus occidentalis Hook, Cupressaceae. The common name of Juniperus occidentalis is western juniper. The present invention also includes a method of controlling odors through the addition of western juniper to litter products and in a preferred embodiment a fragrance is imparted to the western juniper to further enhance the fragrance.
[0007] A second embodiment of the present invention is the use of western juniper to provide a pleasant odor to pesticide products.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The amount of western juniper added to the litter material is effective to control odors. Odor controlling level is understood to mean that undesirable odors are reduced or substantially eliminated by the inclusion of the western juniper material. The amount of western juniper included in the litter is from about 0.01 to about 10 weight percent, preferably from 0.1 to about 8, more preferably from about 0.2 to about 5 weight percent. A highly preferred level of western juniper in the litter is about 0.4 weight percent.
[0009] Western juniper is added to a pesticide in an effective amount to provide an olfactory effect. Olfactory effect is understood to mean that undesirable odors are reduced or a pleasant odor is provided by the inclusion of the western juniper material. The present invention also provides a method for modifying an unpleasant odor, or in a more preferable embodiment providing a pleasant odor to the pesticide.
[0010] The amount of western juniper included in the pesticide product is from about 0.01 to about 10 weight percent, preferably from 0.1 to about 8, more preferably from about 0.2 to about 5 weight percent. A highly preferred level of western juniper in the pesticide product is about 0.4 weight percent.
[0011] As used in this application, pesticide is understood to mean a product that is applied to turf, crops or a specific area to kill or limit the level of insects, fungi or undesired plants. Western juniper can also be added to products such as fertilizers that are applied to stimulate plant growth or production of fruit, flowers, vegetables, and the like. Those with ordinary skill in the art will recognize that fertilizers can and often also contain active ingredients such as insecticides, miticides, and the like; as well as plant specific herbicides that kill or prevent crabgrass, dandelions, and other weeds.
[0012] The form of the western juniper that is added to the litter or pesticide product is not critical. Suitable forms include shredded, chipped and sawdust embodiments. Pesticide products are often granulated or encapsulated for longer delivery periods, safety and other considerations. If a liquid pesticide is desirable, the western juniper can be provided in a liquid form through the use of appropriate surfactants and emulsifiers to keep the particles in the liquid phase until applied.
[0013] When used in a litter, the preferred embodiment is the form most preferred by the animal using the litter. For example, since horses are stabled with straw, the western juniper would be incorporated in a larger size such as chips or shredded material. Since cats prefer small litter materials, it would be preferable that the western juniper be added to the litter in a smaller form, such as sawdust. When used with a pesticide product the western juniper can be formed to blend uniformly with the pesticide material, or if desired can be made of differing sizes so as to be visually distinct to the consumer.
[0014] Without wishing to be bound by any theory it is believed that western juniper is effective as an odor controlling agent, because the essential oil of western juniper contains (+)-Dihydromayurone, see Zhou et al., (+)-Dihydromayurone from Juniperus occidentalis , Planta Medica, 65 (1999) 680-681.
[0015] In a preferred embodiment of the invention, a second odor-controlling amount of fragrance is applied to the western juniper. The western juniper in addition to adding a pleasing scent, acts as a carrier for the second fragrance. The second fragrance is applied to the western juniper in any suitable manner, most commonly the second fragrance is sprayed onto the western juniper. The level of the second fragrance applied to the western juniper can vary widely.
[0016] The amount of fragrance admixed to western juniper is generally from about 0.5 to about 50 of the total weight of the fragrance and western juniper admixture, preferably from about 5 to about 40 weight percent, more preferably from 20 to about 35, and in a highly preferred embodiment about 25 weight percent of the total weight of the fragrance and western juniper admixture. Those with skill in the art will also recognize that the litter material itself can also contain additional fragrant materials without departing from the scope of the present invention. One advantage of the present invention is that the inclusion of the western juniper and optional fragrance does not require the remainder of the litter or bedding material to be scented. This allows less expensive materials to be employed in the bedding materials.
[0017] The amount of fragrance added to a pesticide product is generally from about 0.01 to about 10; preferably from about 0.015 to about 1 weight percent. Most preferably from about 0.02 to about 0.04 weight percent of an additional fragrance is applied to the pesticide product, preferably added to the western juniper, which acts as a carrier for the fragrance.
[0018] The second fragrance is not limited to any specific fragrance, and the fragrance can be selected on the scent desired as well as economic factors. Many types of fragrances can be employed in the present invention, limited only by the desired scent and the suitability for use with any given animal. Suitable fragrances include but are not limited to fruits such as almond, apple, cherry, grape, pear, pineapple, orange, strawberry, raspberry; musk, flower scents such as lavender-like, rose-like, iris-like, and carnation-like. Other pleasant scents include herbal and woodland scents derived from pine, spruce and other forest smells. Fragrances may also be derived from various oils, such as essential oils, or from plant materials such as peppermint, spearmint and the like. Other familiar and popular smells can also be employed, such as baby powder, popcorn, pizza, cotton candy and the like, in the present invention. Preferably the second fragrance is a woody scent which will compliment the natural fragrance of the western juniper.
[0019] A list of suitable fragrances is provided in U.S. Pat. No. 4,534,891, the contents of which are hereby incorporated by reference. Another source of suitable fragrances is found in Perfumes Cosmetics and Soaps, Second Edition, edited by W. A. Poucher, 1959. Among the fragrances provided in this treatise are acacia, cassie, chypre, cyclamen, fern, gardenia, hawthorn, heliotrope, honeysuckle, hyacinth, jasmin, lilac, lily, magnolia, mimosa, narcissus, freshly-cut hay, orange blossom, orchids, reseda, sweet pea, trefle, tuberose, vanilla, violet, wallflower, and the like.
[0020] In addition to the fragrance other agents can be used in conjunction with the fragrance. Well known materials such as surfactants, emulsifiers, polymers to encapsulate the fragrance can also be employed without departing from the scope of the present invention.
[0021] As used herein litter is understood to include any material used as bedding or waste retaining material for pets, livestock or other animals. Suitable materials include without limitation clays, wood chips, sawdust, shredded polymers, such as polyurethane, polyethylene, straw, clumping materials as described in U.S. Pat. Nos. 5,806,462, 5,458,091, 5,452,684, 5,469,809, 5,193,489, 5,101,771 and 5,000,115, the patents herein incorporated by reference as set forth in their entirety. The present invention also contemplates mixtures of the bedding or waste retaining materials in combination with the western juniper materials. The litter products of this invention can be used to inhibit, mask or eliminate animal odors found in environments such as cages, pens, enclosures, bedding, stables and areas where animals such as rats, mice, hamsters, guinea pigs, rabbits, squirrels, monkeys, horses, dogs, cats, raccoons, chickens and other birds are housed or enclosed.
[0022] One advantage of using western juniper is that it is considered a nuisance plant or a weed and it is commonly removed from areas to provide room for more desirable plants. Since it grows quickly and it is considered a weed, western juniper is inexpensive to obtain and can be easily obtained.
[0023] The compositions of the invention are relatively non-toxic to man and animals in the amounts that are added to the litter materials. In addition, Juniperus occidentalis has been reported to have acaricidal activity against Ixodes scapularis which has been linked to Lyme disease, see Zhou et al., (+)-Dihydromayuronefrom Juniperus occidentalis, Planta Medica, 65 (1999) 680-681. This additional biological activity is also believed to provide antibacterial properties that are also helpful in reducing undesirable odors.
[0024] These and additional modifications and improvements of the present invention may also be apparent to those with ordinary skill in the art. The particular combinations of element described and illustrated herein are intended only to represent only a certain embodiment of the present invention and is not intended to serve as limitations of alternative articles with the spirit and scope of the invention.
EXAMPLE 1
[0025] Various commercially available non-fragranced cat litters were purchased and three commercially available fragrances (available from International Flavors and Fragrances Inc.) were tested. The commercially available non-fragranced litters tested were TIDY CAT CRYSTALS, TIDY CAT MULTI CAT (long lasting) and TIDY CAT MULTI-CAT litters, available from the Ralston-Purina Company; FRESH STEP available from the Clorox Company and SUPER STOP available from Church & Dwight.
[0026] The three fragrances were added to the western juniper shavings at a level of 25 weight percent. The fragrance and western juniper admixture was added to the non-fragranced cat litter at a level of 0.4 weight percent. In addition, the same level of fragrance was added to the commercially available litters as was added to the western juniper.
[0027] The evaluation procedure was as follows: 50 grams of cat litter, both the commercially available unscented materials, the cat litter and the fragrance and those containing the western juniper and fragrance, were added to four ounce jars. One-half milliliter of cat urine was added to the jars and the jars were capped. Odors were allowed to accumulate in the headspace of the jars over one, two and three hours. The jars were opened and sampled for urine smell.
[0028] The samples that contained the mixture of fragrance and western juniper shavings performed much better than any of the commercially available litters, even those that contained fragrance. The litter containing the fragrance and western juniper shavings had little or no objectionable odor and in some instances a pleasant odor was still detected.
EXAMPLE 2
[0029] A suitable fragrance for use with a pesticide product is provided below. The fragrance was developed to be incorporated with the western juniper at the levels set forth in the specification above.
Name Weight Amyl Cinnamic Aldehyde 2 Amyl Salicylate 10 Aubepine 2.5 Benzyl Acetate 12.5 Bergamot Oil 22 Caraway Oil 0.4 Cedarwood Oil 1 Citronella Oil 2.5 Civet 10% DPG 0.8 Dimethyl Hydroquinone 0.2 GALAXOLIDE 50% DPG (IFF) 16.8 Geranium 3.8 HEDIONE (Firmenich) 2 Heliotropine 3.4 Indolarome 10% DPG 0.4 ISO E SUPER (IFF) 2 Lavandin Grosso 4 Linalyl Acetate 1 Methyl Salicylate 1 Patchouli Oil Light 1 Phenyl Ethyl Alcohol 2 Spearmint Oil 1 Tangerine Oil 1 Terpinyl Acetate 1.3 Vanillin 3.6 VERAMOSS (IFF) 0.8 Vertofix Coeur 1 TOTAL 100
[0030] As used in the chart above, the following initials and suppliers are understood to mean the following:
[0031] DPG is dipropylene glycol;
[0032] IFF is International Flavors & Fragrances Inc., Hazlet, N.J.; and
[0033] Firmenich is Firmenich Incorporated, Plainsboro, N.J. 08536.
[0034] Unless noted to the contrary all of the fragrance materials provided above are available from International Flavors & Fragrances Inc., Hazlet, N.J. 07730.
[0035] All percentages are by weight unless noted to the contrary. | Odor-inhibiting materials comprising litter containing an odor-inhibiting quantity of western juniper. The litter materials of the present invention are advantageous in that they can be used as animal bedding and the like to mask or prevent the formation of undesirable odors in animal laboratories, pet shops, litter boxes, kennels and the like. In another application, western juniper is used to provide a pleasant odor to pesticide materials. | 0 |
This is a Continuation of application Ser. No. 07/111,232, filed 10/22/87, now Pat. No. 490,7897.
BACKGROUND OF THE INVENTION
The present invention relates to a bearing device used in an electric motor employed for driving a computer hard disk having a high recording density and capacity.
A bearing device in a spindle motor for driving a hard disk of a type earlier designed by the present applicant (not prior art) is arranged as shown in FIG. 1. Data signal recording media having a high recording density and capacity, namely, magnetic disks 17, are mounted on a hub 6 fixedly fitted on one end portion of the rotary shaft of the spindle motor. A bearing 33 is fixedly positioned in a bearing holder 9 with a retainer 32. A coil spring 36 is positioned with a retainer 35 in such a manner that it is held between the retainer 35 and another bearing 34 which is movably fitted in the bearing holder. The coil spring 36 applies pressure to the bearing 34 to minimize the amount of play between the balls and the inner and outer races. A rotor case 29 is fixedly mounted on the other end portion of the rotary shaft so that the inclination of the shaft and accordingly the inclination of the magnetic disks is minimized. A magnetic seal mechanism including a magnet 16 held between two yokes 14 and 15 and a magnetic fluid 17 is provided at the upper end portion of the bearing holder so that metal powder formed by abrasion of the bearings is prevented from being scattered to the outside. A shield yoke 37 is fixedly fitted on the upper end portion of the bearing holder to prevent the magnetic disks from being affected by the magnet 16.
In this bearing device, the bearing holder is made of aluminum or steel (SUS 303), the bearings are made of bearing steel, and the shaft of steel (SUS 416), for instance. That is, these components are formed from different materials, and accordingly they have different thermal expansion coefficients. As a result, as the temperature of the bearing device changes, gaps are formed between the components, the shaft is inclined, and the magnetic disks are tilted. Furthermore, the shield yoke 37 and the retainers 32 and 35 have smaller thermal expension coefficients than the bearing holder. Therefore, as the temperature of the bearing device changes, the bearing holder, being locally strained, tends to deform. As a result, it is difficult to maintain the recording reproducing heads in stable sliding contact with the magnetic disks; that is, it is impossible to perform high density recording and errors are liable to occur during recording.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of this invention is to provide a bearing device in which the shaft, the bearings and the bearing holder respond substantially the same to changes in temperature so that the amount of inclination of the shaft due to temperature changes is minimized, whereby high precision is maintained.
A specific feature of the invention resides in a bearing device comprising a shaft, bearings supporting the shaft, and a bearing holder adapted to hold the bearing, in which the shaft, the bearings, and the bearing holder are made of materials which have substantially the same thermal expansion coefficient.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional side view showing an example of a conventional bearing device used in an electric motor for driving hard disks;
FIG. 2 is a sectional side view showing a first example of a bearing device according to the invention which is used in an electric motor for driving hard disks;
FIG. 3 is an enlarged sectional view showing the first example of the bearing device according to the invention;
FIG. 4 is a sectional side view showing a second example of a bearing device according to the invention; and
FIG. 5 is a sectional side view showing a third example of a bearing device according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described with reference to preferred embodiments shown in the accompanying drawings.
FIGS. 2 and 3 show a first embodiment of a bearing device of the invention. As shown in FIGS. 1 and 2, in the inventive bearing device, the lower end portion of a bearing holder 2, which is substantially in the form of a cylindrical pipe, is fitted in a central hole formed in a housing 1, and bearings 3 and 4 with no inner race are fitted in the bearing holder 2 to support a shaft 5. The bearing 3 includes balls 10 engaged with an annular groove 5a formed in the shaft 5 and an outer race 12. Similarly, the bearing 4 includes balls 11 engaged with an annular groove 5b formed in the shaft 5 and an outer race 13.
A magnet 16 held between two yokes 14 and 15 is fitted in the upper portion of the bearing holder 2. A seal mechanism impregnated with magnetic fluid 17 is provided between the shaft and the inner peripheries of the yokes.
A hub 6 is fixedly mounted on the upper end portion of the shaft 5. A plurality of magnetic disks 17 together with spacers 18 are mounted on the cylindrical outer wall of the hub 6. A disk clamp 19 is secured to the hub 6 with screws 20 so that the magnetic disks 17 are secured to the hub 6. Rotor magnets 21 are fixedly secured to the inner cylindrical wall of the hub 6.
A stator core 22 is mounted on the bearing holder 2 and secured to the latter with an adhesive agent, or to the housing 1 with screws (not shown).
The bearings 3 and 4 are secured to the bearing holder 2 as follows: A step 2a is formed in the upper portion of the inner wall of the bearing holder 2. The bearings 3 and 4 fitted on the shaft 5 are inserted into the bearing holder 2 from above by shrink fitting until the outer race 12 of the upper bearing 3 abuts against the step 2a. The outer race is secured with adhesive. Thereafter, the outer race 13 of the lower bearing 4 is pushed upwardly, and is fixed with an adhesive injected through small holes 2b.
When the bearings 3 and 4 have been secured in the above-described manner, the balls 10 and 11 are pushed against the edges of the grooves 5a and 5b under pressures to be positioned at a predetermined position so that play is absorbed.
In the above-described bearing device, the bearing holder 2 is made of martensite stainless steel (SUS 403), the bearings 3 and 4 of bearing steel (SUj2), and the shaft of martensite stainless steel (SUS 420).
The bearing holder 2, the bearing 3 and 4, and the shaft 5 may be made of martensite stainless steel (SUS 403) or bearing steel (SUj2).
The thermal expansion coefficients of the aforementioned steel materials are as follows:
Martensite stainless steel:
______________________________________(SUS 403) 9.9 × 10.sup.-6 /°C.(SUS 420) 10.3 × 10.sup.-6 /°C.Bearing steel 9.8 × 10.sup.-6 /°C.______________________________________
Thus, in the above-described bearing device, the bearing holder 2, the bearing 3 and 4, and the shaft 5 are made of materials which have substantially equal thermal expansion coefficients. Hence, the assembly is stable in the face of thermal changes. Therefore, the shaft 5 is substantially prevented from being thermally deformed. Thus, when the bearing device is used in a hard disk driving motor, high density and high capacity recording and reproducing operations can be stably performed, and the occurrence of errors is greatly reduced.
As described above, the bearing device is of the predetermined position pressurization type. Therefore, the pressurization is maintained unchanged, and the load characteristic of the bearing device is maintained stable.
Furthermore, because the play of the bearing in the radial direction is absorbed, the shaft is substantially prevented from being deformed by heat.
In addition, since the bearing holder 2 is made of magnetic material, the bearing device of the invention needs no shield yoke 37 as must be included in the conventional bearing device. That is, the shield yoke, the retainers 32 and 35, and the O-ring 38 of the conventional bearing device described above are not used in the bearing device of the invention. Therefore, in the bearing device of the invention, the bearing holder 2 is not strained.
FIG. 4 shows a second embodiment of the invention. In this embodiment, a step 2a is formed in the inner wall of a bearing holder 2. A bearing 3 is inserted into the bearing holder until it abuts against the step 2a, and it is secured with an adhesive. As a result, the balls 10 and 11, engaged with annular grooves 5a and 5b formed in a shaft 5, are pushed against the edges of these grooves under a predetermined pressure. Another collar 26 is fitted on the upper end portion of the shaft 5.
Similar to the first embodiment, in the second embodiment the bearing holder, the bearings 3 and 4, and the shaft 5 are made of materials having substantially equal thermal expansion coefficients.
FIG. 5 shows a third embodiment of the invention. Bearings 7 and 8, each having an inner race and an outer race, are fitted in a bearing holder 2 and secured thereto with an adhesive, thus supporting a shaft 5. The bearing 7 is positioned on the upper step 2a of a protrusion 2b extending inwardly from the inner wall of the bearing holder 2. A coil spring 24 is positioned on the lower step 2c of the protrusion 2b in such a manner that it is located between the lower step 2c and the bearing 8. Therefore, the balls 11 of the bearing 8 are pushed against the lower edge of the groove in the outer race 27 and the upper edge of the groove in the inner race 28 under a predetermined pressure.
Similar to the conventional bearing device of FIG. 1, the lower end portion of the bearing holder 2 is secured to the housing 1, a hub 6 is fixedly mounted on the upper end portion of the shaft 5, and a rotor case 29 is secured to the lower end portion of the shaft 5. Rotor magnets 21 are fixedly secured to the inner wall of the rotor case 29, and a stator core is fixedly secured to the lower end portion of the outer cylindrical wall of the bearing holder 2 in such a manner that it confronts the rotor magnets 21. A ball 30 fitted in the lower end face of the shaft 5 is positioned on a receiving place 31 secured to the housing 1.
In the above-described embodiments, the bearings 3, 4, 7 and 8 are ball bearings. However, metal bearings having substantially equal thermal expansion coefficients may be employed.
As described above, in the bearing device of the invention, the shaft, the bearings and the bearing holders are made of materials which have substantially equal thermal expansion coefficients. Therefore, even if the dimensions of these components change with the temperature of the bearing device, no gaps are formed between the various components, and accordingly the shaft is not deformed by heat. Thus, the bearing device of the invention is highly precise and can be applied to a variety of rotary machines, especially to an electric motor for driving a hard disk in which the inclination of the shaft should be as small as possible. In the latter case, the magnetic disk is not inclined due to thermal deformation of its shaft, and therefore the recording and reproducing head can be brought into sliding contact with the magnetic disk with high stability. Accordingly, with the bearing device of the invention, high density and high capacity recording operations can be achieved with significantly less error. | An improved bearing device for use in a spindle motor for driving computer hard disks is disclosed. The device includes a shaft, bearings supporting the shaft, and a bearing holder for holding the bearings. The bearing holder is made of a magnetic material. The shaft, the bearings, and the bearing holder are made of materials having substantially the same thermal expansion coefficient. | 5 |
FIELD OF THE INVENTION
This invention relates to air filtration masks, more particularly to a mask for grooming dogs with chalk, which mask includes filtration means and a transparent visor.
BACKGROUND OF THE INVENTION
Show dogs, particularly terriers, are prepared for exhibition and judging by, among others things, dusting the coat of the dog with chalk powder. First the dog's legs are wetted with water and VASELINE brand lubricant is put on the legs. The furnishings of the legs are then dusted with chalk to highlight their appearance. This process may take up to one-half hour and can be discomfiting to the dog. The dust may irritate the dog's eyes. This irritation not only causes watering and possibly reddening of the eyes, which conditions are unsightly in a show dog, but could conceivably cause the dog injury. In addition, the dust can enter the dog's lungs, which also can cause irritation and possible injury. Lastly, because this process can be upsetting to the dog, it can affect the dog's demeanor during exhibition.
Show dogs of this type are very valuable--they can sell for thousands of dollars. Furthermore, the dogs' owners are very emotionally attached to their pets and do not wish to cause them discomfort.
For this reason, there has been a need for means to protect terriers from the chalk dust which is used during the grooming process.
U.S. Pat. Nos. 3,918,238 to P. Iozzio and 3,742,679 to C. Jordan both teach protective wear for dogs. However, neither protects either the eyes or the nose of the dog and are thus unsuitable for use in the field of the present invention.
SUMMARY OF THE INVENTION
The present invention is a canine grooming mask which protects show dogs from the harmful effects of grooming chalk on their eyes and lungs. The mask utilizes filter paper or other filtration means to keep the chalk dust out of the dog's lungs while allowing the dog to breathe comfortably and naturally. A plastic visor protects the dog's eyes. The visor is transparent so that the dog can still see while being groomed. This is important for keeping the dog calm during what is otherwise a disturbing process.
The mask of the present invention utilizes a band which passes over the top of the dog's head between its ears to connect the body of the mask to a collar for the dog's neck. Because the crown band passes between the ears, the mask cannot rotate out of position.
Although different sizes of mask can be made for different classes of dogs, a particular mask can be adjusted to fit a particular dog by the use of a unique process. A planar filtration panel can be curved into a cone of varying shapes and sizes as dictated by the shape of the muzzle of the dog. Hook and loop fastening strips allow for adjustable fastening of the sides of the panel to retain the proper conical shape.
FEATURES AND ADVANTAGES
An object of this invention is to provide a dog grooming mask which filters the air the dog breathes while being groomed.
It is another object of this invention to both protect the dog's eyes and allow the dog to continue to see during the grooming process.
Yet another object is to provide a mask which is capable of remaining in place during the time of grooming without undue readjustment by the groomer.
To achieve the above and other objects of the invention, there is proposed, in accordance with a preferred embodiment thereof, a mask with a crown band to which is attached air filtration means and a collar for the dog's neck.
In accordance with a feature of the invention the collar is attached perpendicular to the crown band in order that the crown band may pass over the top of the head and still allow the collar to pass around the dog's neck.
In further accordance with the invention, the filtration means is filter paper formed in a flat panel. A transparent plastic visor panel is attached to the filter paper panel for shielding the eyes.
In accordance with another feature of the invention, adjustable attachment means are provided on the two sides of the paper panel which allow that panel to be curved into the shape of a cone and fastened in that position for covering the muzzle. Adjustable attachment means are also provided for securing the ends of the collar together.
Both attachment means referred to above may may consist of interlocking hook and loop strips, commonly sold under the trademark VELCRO.
Other novel features which are characteristic of the invention, as to organization and method of operation, together with further objects and advantages thereof will be better understood from the following description considered in connection with the accompanying drawing in which a preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only and is not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the mask of the present invention showing a dog, in phantom, wearing the mask; and
FIG. 2 is a front view of the mask of FIG. 1 in an open position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 2, there is shown therein a preferred canine grooming mask, generally designated as 2. Mask 2, prior to use, is flat; that is, all its components lie parallel to the plane of the drawing, with the exception of the corner containing a portion of strip 14 which is shown upturned for purposes of illustration only.
Mask 2 comprises five main components: muzzle panel 4; transparent visor 6; brow portion 8 (components 4,6,8 comprising the body 11 of the mask); crown band 9; and collar 10. Muzzle panel 4 is preferably made of filter paper through which air may freely pass but which traps chalk dust and similar particulate contaminants. Panel 4 could also be made of cloth or other material with suitable filtering properties.
Panel 4 is attached to a visor 6, the latter of which is made of a flexible transparent plastic which is impervious to dust. Visor 6, in turn, attaches to a transitional brow portion 8 for securing the body 11 of the mask 2 to crown band 9.
Crown band 9 connects body 11 to a neck collar 10. Parts 8,9,10, in the preferred embodiment are all made of the same filter paper as muzzle panel 4 in order to reduce expense and simplify manufacture. However, parts 8,9,10 could be made of more durable material, such as leather, if a non-disposable mask were desired.
For securing the mask 2 in place on a subject dog, hook and loop means are provided. Hook and loop strips are commonly available and are sold under the trademark VELCRO. The sides of the body 11 of mask 2 are secured in place by body hook strip 12 which attaches to body loop strip 14 when the muzzle panel 4 is bent over upon itself in the shape of a cone.
The ends of collar 10 are fastened together by collar hook strip 16 which attaches to collar loop strip 18 when the collar is looped around the neck of a dog.
Turning to FIG. 1, the mask 2 of FIG. 2 is shown fastened in place on the head of a subject dog 20 (in phantom). Stitching 21, which is used to hold the components of the mask 2 together, is shown in portions of FIG. 1, but is omitted from FIG. 2 for clarity.
Panel 4 is turned in upon itself over muzzle 22 of dog 20 and hook strip 12 is pressed in place upon the portion of loop strip 14 which it overlaps (greater or lesser portions of strips 12,14 overlap depending on the size of the dog's muzzle 22). Body 11 is adjusted in place over muzzle 22 such that nostril portion 5 of panel 4 covers the dog's nostrils 32 and transparent panel 6 covers the dog's eyes 30. The body 11 forms a cone when the panel 4 is rolled in this manner. In an alternate embodiment (not illustrated), a protruding flap, preferably rectangular in shape, can be added to portion 5 so that an aperture, which might otherwise open up at the end of the cone when the mask is used on dogs with wide muzzles, can be closed.
Band 9 is passed up over the crown 24 of the dog's head so that it is situated between, and is held in place by, ears 26. The ends 17,19 of collar 10 are then looped over themselves so that hook strip 16 may be pressed in place on loop strip 18, fastening the collar 10 to the dog's neck 28. Through the use of mask 2 in this manner, the dog 20 may see and breathe in comfort while being groomed.
While the above provides a full and complete disclosure of the preferred embodiments of this invention, various modifications, alternate constructions, and equivalents may be employed without departing from the true spirit and scope of the invention. For example, panel 4 could be made replaceable by the addition of separate hook and loop attachment means for securing it to the body 11 instead of stitches 21. Therefore, the above description and illustrations should not be construed as limiting the scope of the invention which is defined by the appended claims. | A dog filtration mask including a crown band having first and second ends; air filtration paper or cloth attached to the first end of the crown band; and a collar attached to the second end of the crown band. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of International Patent Application No. PCT/CN2012/000045 with an international filing date of Jan. 10, 2012, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201110149858.0 filed Jun. 5, 2011. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a method for manufacturing a disordered porous silicon dioxide material and a use of fatty alcohol polyoxyethylene ether in such a manufacturing method.
[0004] 2. Description of the Related Art
[0005] According to the definition of the International Union of Pure and Applied Chemistry, the porous material can be classified into three types on the basis of the magnitude of pore size: a microporous material with a pore size of less than 2 nm, a macroporous material with a pore size of larger than 50 nm, and a mesoporous material with a pore size between 2 and 50 nm. On the basis of the feature of the pore structure, the porous material can be classified into an ordered porous material and a disordered porous material. In 1992, the researchers in Mobil Corporation made a break-through in the conventional technique in which a single solvated molecule or ion acts as a template during the synthesis of microporous zeolite molecular sieve, and succeeded in synthesizing the M41S series ordered aluminosilicate mesoporous material with a large specific surface area, regularly-arranged channels, and an adjustable pore size through the self-assembly function of organic/inorganic components in the solution. This series of ordered mesoporous material includes MCM-41, MCM-48, and MCM-50 layered structures. Thereafter, various synthesizing systems and synthesizing approaches have been proposed. The mesoporous material has been widely used for catalysis, adsorption and separation, micro-reactor, sensor, or the like.
[0006] During manufacturing of the disordered porous material, micrometer-scale silicon spheres with relatively uniform dimensions are manufactured as follows. TEOS are hydrolyzed to form cores, and then octadecyltrimethoxysilane and tetraethyl orthosilicate are added simultaneously for hydrolysis and condensation so as to form small spheres with a micrometer structure. The octadecyl is removed by firing, so as to form disordered mesoporous silicon dioxide. Thereafter, non-magnetic ferric oxide (Fe 2 O 3 ) nano-particles with a dimension of 120 nm are employed, and octadecyltrimethoxysilane and tetraethyl orthosilicate are added for simultaneously for hydrolysis and condensation to deposit silicon species on the surface of Fe 2 O 3 particle. Thus, a mesoporous silicon oxide outer shell by calcination is obtained, and finally a magnetic microsphere with a core of Fe 3 O 4 and an outer shell of mesoporous SiO 2 by reducing at high temperature hydrogen is collected. The microsphere has a dimension of about 270 nm, a mesoporous pore size of about 3.8 nm, a specific surface of 283 m 2 /g, a hole volume of about 0.35 cm 3 /g, and a relatively strong magnetic response (27.3 emu/g), which greatly facilitates its applications. A conventional magnetic core/disordered mesoporous silicon dioxide shell manufactured by means of a self-assembly method has a diameter of about 300 nanometer, and the specific surface area of the mesoporous silicon sphere can be controlled by the amount of addition to the systems. As octadecyltrimethoxysilane which has a template function for forming mesoporous silicon dioxide increases in the amount of addition, the number of pores in each mesoporous microsphere in the systems increases, thus resulting in decrease in the dimension of mesopores and remarkably increase in the specific surface area. When the amount of addition reaches a certain amount, the pore size of mesoporous microspheres tends to maintain at a certain level.
[0007] However, during manufacturing of porous microspheres with nano-structure (including the research described above), it is commonly adopted in the art to provide a very high solvent ratio, in which a large amount of solvent is used to dilute the solute, so as to control the size of nano-scale microsphere and inhibit agglomeration, such as, microspheres with a size of 100-1000 nanometers (a solvent ratio of 1:5300), mesoporous microspheres with a size of 70 nanometers (a solvent ratio of 1:4000), mesoporous silicon spheres with a size of 30-50 nanometers with a solvent ratio of 1:2600, and highly-ordered silicon spheres with a size of about 120 nanometers with a solvent ratio of 1:1200. This kind of manufacturing method may greatly increase the manufacturing cost, because the large amount of reaction solvent can only produce few materials, thus making it not applicable for industrial production. Besides, the dispersity and uniformity in size are not ideal for the nano-particles produced by these methods.
[0008] Therefore, although the manufacturing of disordered porous silicon dioxide materials involves a relatively large range, the overall manufacturing is still in the early stage of development. In addition, it is well known that nano-particles tends to agglomerate and coagulate during reaction, so that it is impossible for particles to sufficiently disperse in the liquid media, and the particles are not uniform in size, thus greatly influence their practical applications. This phenomenon always occurred in the precedent researches. However in the literature up to now, these serious drawbacks have not or less been mentioned by the researchers. Therefore, there is no report regarding a good solution against agglomeration and coagulation in the prior art. In particular, there is no report regarding small particle mesoporous materials which have good dispersity, uniform size, and excellent performances to facilitating industrial production.
SUMMARY OF THE INVENTION
[0009] The fatty alcohol polyoxyethylene ether associated with manufacturing of disordered porous silicon dioxide materials in the invention is used as a leveling agent in the prior art, has a trade name of Peregal O, and belongs to a class of nonionic surfactants. It has a strong leveling property, retarding ability, permeability, and diffusivity for various dyes, has scouring aiding performance during scouring, and can be used with various surfactants and dyes by dissolving with them. It has been widely applied in respective process for the textile dyeing industry. There is no related research which has indicated that when it is applied for manufacturing disordered porous silicon dioxide materials, the excellent effects in which the disordered porous silicon dioxide materials have good dispersity and uniform particle grain size can be achieved.
[0010] In view of the above-described problems, it is one objective of the invention to provide a method for manufacturing a disordered porous silicon dioxide material comprising applying a fatty alcohol polyoxyethylene ether. By using such an additive, it is possible for the resulting disordered porous silicon dioxide materials have uniform particle size and particle dispersity; what is more important is that the disordered porous materials are no longer available by means of a large amount of matched solvent. As a result, the bottleneck conditions in which too much solvent is needed during manufacturing are broken, so that the manufacturing of the disordered porous materials is applicable for industrial mass production.
[0011] To achieve the above objective, in accordance with one embodiment of the invention, there is provided a method for manufacturing a disordered porous silicon dioxide material comprising applying a fatty alcohol polyoxyethylene ether as an additive, wherein the fatty alcohol polyoxyethylene ether has a formula of RO—(CH 2 CH 2 O) n —H, R is C 8-24 H 17-49 , and n=9-30.
[0012] The fatty alcohol polyoxyethylene ether is used as an additive for increasing particle dispersity of disordered porous silicon dioxide materials. The added fatty alcohol polyoxyethylene ether further enables the resulting disordered porous silicon dioxide materials to have good uniformity in particle size. The additive can increase solvent ratio during manufacturing, thus greatly reducing the required amount of solvent during manufacturing of disordered porous silicon dioxide materials. The solvent ratio in the invention refers to the mass ratio between the added raw material and the solvent.
[0013] The role of the fatty alcohol polyoxyethylene ether plays in manufacturing disordered porous silicon dioxide materials is as follows. Firstly, long-chain-alkyl silane is used as a template to form a certain steric configuration. Then, a silicon precursor such as tetraethyl orthosilicate hydrolyzes by taking the long-chain-alkyl silane as a kernel and gradually fills therebetween. At the same time, the fatty alcohol polyoxyethylene ether gradually grows and then forms a steric hindrance, which inhibits tetraethyl orthosilicate from accumulating continuously so as to prevent further growth of particle as well as fusion and adhesion between each other. In this way, even when the amount of solvent is reduced significantly, not only the material can still possess good dispersity (see FIGS. 3-4 ) and particle uniformity (see FIG. 5 ), but also it is possible to adjust the size by controlling the amount, synthesizing time, or the like. Reference is made to FIG. 1 for explaining the underlying mechanism.
[0014] In a class of this embodiment, the fatty alcohol polyoxyethylene ether has a formula of RO—(CH 2 CH 2 O) n —H, wherein R is C 16-18 H 33-37 , and n=9-30.
[0015] In a class of this embodiment, the disordered porous silicon dioxide material comprises (A) a silicon dioxide material with a long-chain alkyl and a disordered microporous structure; (B) a silicon dioxide material with a disordered mesoporous structure; (C) modifying (A), (B) materials respectively to be connected with a functional group; or (D) embedding in (A), (B), or (C) material respectively with an inclusion material.
[0016] In a class of this embodiment, the number of C (carbon) in long-chain alkyl is not less than 8, and preferably 8-20.
[0017] In accordance with another embodiment of the invention, there is provided a method for manufacturing a disordered porous silicon dioxide material, the disordered porous silicon dioxide material comprising (A) a silicon dioxide material with a long-chain alkyl and a disordered microporous structure; (B) a silicon dioxide material with a disordered mesoporous structure; (C) modifying (A), (B) materials respectively to be connected with a functional group; or (D) embedding in (A), (B), or (C) material respectively with an inclusion material, and
the method for manufacturing the (A) material comprising hydrolyzing a raw material comprising a silicon precursor, long-chain-alkyl silane, and fatty alcohol polyoxyethylene ether in a solvent, and then ageing, filtering, and eluting; the method for manufacturing the (B) material comprising hydrolyzing a raw material comprising a silicon precursor, long-chain-alkyl silane, and fatty alcohol polyoxyethylene ether in a solvent, and then ageing, filtering, drying, and calcining; the method for manufacturing the (C) material in any one of the following two manners:
1) adding a compound with a functional group into a raw material comprising a silicon precursor, long-chain-alkyl silane, and fatty alcohol polyoxyethylene ether; and hydrolyzing in a solvent and then ageing, filtering, and eluting to yield the (C) material, or hydrolyzing in a solvent and then ageing, drying, and calcining to yield the (C) material; or 2) hydrolyzing any one of the resulting (A) and (B) materials in an organic silane with a functional group to yield the (C) material;
the method for manufacturing the (D) material in any one of the following two manners:
1) adding a solvent in advance into an inclusion nano-particle which has been subject to dispersion treatment, then adding a raw material comprising a silicon precursor, long-chain-alkyl silane, and fatty alcohol polyoxyethylene ether, and hydrolyzing, ageing, filtering, and eluting to yield the (D) material, or hydrolyzing, ageing, filtering, drying, and calcining to yield the (D) material; or 2) soaking any one of (A), (B) or (C) material in a precursor solution of the inclusion material, and diffusing, reacting, or reducing to yield the (D) material.
[0026] In a class of this embodiment, the long-chain-alkyl silane is selected from RnXS, wherein R represents alkyl, n is the number of C, which is not less than 8, preferably n=8-20, X is a group for hydrolyzing the silane, and S represents silicon.
[0027] In a class of this embodiment, the functional group comprises a functional group for purpose of coupling and/or modifying. By means of a functional group for coupling, an intermediate product is obtained; by means of the functional group for coupling on the intermediate product to connect a functional group for modifying, a silicon dioxide material modified with the functional group is obtained; or the functional group for modifying is connected directly with the silicon dioxide material.
[0028] In a class of this embodiment, the functional group comprises one or more of amino, sulfydryl, ethyoxyl, alkyl, mercaptopropyl, and methoxy.
[0029] In a class of this embodiment, the inclusion material comprises nanometer Au, Pt, light-emitting quantum dots, nanometer silicon spheres, or magnetic particles, so that the material has characteristics of light-emitting, magnetic response or the like.
[0030] In a class of this embodiment, the solvent involved in the invention is a conventional solvent for dissolving and dispersing the raw material during manufacturing of disordered porous silicon dioxide materials.
[0031] During manufacturing of the disordered porous silicon dioxide material in the invention, the primary raw materials for manufacturing comprise a silicon precursor, long-chain-alkyl silane, and Peregal O. In case of absence of a calcining step, a silicon dioxide material with a long-chain alkyl and with a microporous structure is obtained. While in case that the silicon dioxide material with a microporous structure is subject to calcining for removing the long-chain alkyl, a silicon dioxide material with a mesoporous structure is obtained.
[0032] In the manufacturing method described in the invention, the solvent ratio can be greatly increased (for example, in Example 2 of the invention, up to 1:55), while the manufactured material has a uniform size, the hole and particle size can be adjusted. Besides, the material has a good dispersity, and is absolutely applicable for industrial mass production.
[0033] The silicon dioxide material with a mesoporous structure, which is calcined to remove the long-chain alkyl, has a large pore volume and specific surface area. The specific surface area may amount to 1,366 m 2 /g, and the pore volume may amount to 1.31 cc/g. The large specific surface area and pore volume enable the silicon dioxide material to be widely applied in various professional fields.
[0034] The disordered porous silicon dioxide materials manufactured in the invention are nearly spherical silicon dioxide particles, the particle diameter may be in the range of 40-5,000 nanometers, and the particle mesoporous channels are arranged in a disordered manner. In the invention, an inclusion material like nanometer Au, Pt, light-emitting quantum dots, or magnetic particles may be embedded in the material in advance or introduced in mesoporous channels after material manufacturing. The mesoporous silicon dioxide material particles and channels may be connected with functional groups at the surface.
[0035] Specifically, the method for manufacturing the disordered porous silicon dioxide material comprises the following steps:
1) evenly mixing a solvent of water and alcohol, adding the prepared mixture of the silicon precursor, long-chain-alkyl silane, and Peregal O, stirring to mix evenly, then adding an acid/base like ammonia water or hydrochloric acid, and stirring continuously for hydrolyzing; 2) ageing, filtering, eluting, and drying the substance in step 1), to obtain a silicon dioxide material with a long-chain alkyl and a disordered microporous structure; and 3) calcining to remove long-chain alkyl so as to obtain a silicon dioxide material with a disordered mesoporous structure.
[0039] The functional group may be introduced during manufacturing of the disordered porous materials. The solvent like water, alcohol is mixed evenly, the prepared mixture of silicon precursor, long-chain-alkyl silane, and Peregal O is added to the solvent, stirred to mix evenly. Then an acid/base like ammonia water or hydrochloric acid, and the compound with a functional group to be connected are added, stirred continuously for hydrolyzing, and subject to ageing, filtering, eluting, and drying. As required, a calcining step is added or not added to remove template long-chain alkyl, thus yielding the corresponding product.
[0040] The functional group may be introduced after manufacturing of disordered porous materials. By hydrolyzing the organic silicon, a functional group for coupling is grafted and modified on the internal channels and outer surface of the product, thus yielding an intermediate product. By connecting a functional group for grafting with the functional group for coupling on the intermediate product, a product material grafted and modified with a functional group is obtained. Some functional groups can be directly grafted and is not necessary to be connected through an intermediate group for coupling.
[0041] The inclusion material like nanometer Au, Pt, light-emitting quantum dots, or magnetic particles may be introduced during manufacturing of disordered porous materials. An inclusion material precursor, which has been subject to dispersion treatment, is added in advance with a solvent like a mixture of water and alcohol and mixed evenly; a prepared mixture of silicon precursor, long-chain-alkyl silane, and nonionic long-chain surfactant is further added and stirred to mix evenly; then an acid/base like ammonia water or hydrochloric acid is further added and stirred continuously for hydrolyzing; a corresponding product is formed by ageing and filtering, in which a calcining step is added or not add as required to remove template long-chain alkyl.
[0042] The inclusion material like nanometer Au, Pt, light-emitting quantum dots, or magnetic particles may be introduced after manufacturing of disordered porous materials. The product in which the template is removed or not removed is soaked in a precursor solution of inclusion material. The material comprising the final inclusion material in holes is obtained by diffusing, reacting, or reducing.
[0043] In a class of this embodiment, the deionized water, alcohol, ammonia water or hydrochloric acid in the solvent have a volume ratio of 1:(0.1-30):(0.1-10).
[0044] In a class of this embodiment, the silicon precursor, long-chain silane, and nonionic surfactant have a molar ratio of 1:(0.1-10):(0.2-5).
[0045] In a class of this embodiment, tetraethyl orthosilicate (and other raw materials like sodium silicate which similarly serves for hydrolyzing) is applied as the silicon precursor.
[0046] In a class of this embodiment, the long-chain-alkyl silane is preferably selected from RnXS, wherein R represents alkyl, n represents the number of C=8, 10, 12, 14, 16, 18, or 20, and R includes normal or heterogeneous alkyls obvious for the skilled in the art. After the template long-chain alkyl is removed, mesoporous materials with different pore size, pore volume, and specific surface area are obtained. X refers to the group in these silanes for hydrolyzing. In a manner which is apparent for the skilled in the art, since these groups are eventually removed during silane hydrolyzing, their presence and difference only indicate difference in choosing the process during hydrolyzing, and all of the final products are RnSiO 2 .
[0047] In a class of this embodiment, in step 1), the preparation reaction is conducted at room temperature (RT).
[0048] In a class of this embodiment, in step 1), the stirring time for the preparation reaction is 2-24 hours.
[0049] In a class of this embodiment, in step 2), ageing is conducting under RT for 1-24 hours.
[0050] In a class of this embodiment, in step 2), separation is conducted by filtering or centrifugal separation.
[0051] In a class of this embodiment, in step 2), drying is conducted under RT for 1-24 hours.
[0052] In a class of this embodiment, in step 2), the template is removed by firing, the heating rate is 0.1-30° C./min, and the temperature is maintained at 200-700° C. for 2-20 hours. By means of extraction, the extraction is conducted with 70° C. alcohol for 48-120 hours.
[0053] In a class of this embodiment, the functional groups for modifying and grafting are various organic silane coupling agents, and react by dehydration condensation with hydroxyl which is rich on the surface of the disordered porous materials, thus forming Si—O—Si bonds which are connected at the surface of the disordered porous materials.
[0054] As compared with the resulting material of the prior art, the disordered porous silicon dioxide materials manufactured by using the invention have the outstanding features and significant improvement in that they have excellent dispersity, uniform size for the material particle, low tendency of large difference in particle size during manufacturing of this type of material in the existing methods. Besides, the size can be adjusted, and the manufacturing process is simple and has a relatively short production cycle. The bottleneck conditions in which too much solvent is needed during manufacturing are broken, so that it is easy to implement industrial mass production. Furthermore, the material may be embedded in advance, or an inclusion material like nanometer metal, light-emitting quantum dots, and magnetic particle may be introduced in mesoporous channels after preparation of the material, so that material has a characteristic like light-emitting, magnetic response or the like. In addition, the surface functional group may also be modified during preparation or after preparation, thus greatly expanding the application field.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] FIG. 1 . is a schematic diagram showing the synthesizing mechanism of a disordered micropore silicon dioxide material;
[0056] FIG. 2 . is a schematic diagram showing the molecule structure of a disordered micropore silicon dioxide material (A);
[0057] FIG. 3 shows TEM photographs of a disordered micropore silicon dioxide material which is not added and added with Peregal (a: a TEM photograph showing Peregal is not added to the material, b: a TEM photograph showing Peregal is added to the material, see Example 1);
[0058] FIG. 4 shows TEM photographs of a disordered micropore silicon dioxide material which is not calcined and is calcined; a1: a global TEM showing the material which is not calcined and has a disordered microporous structure, a2: a local TEM showing the material which is not calcined and has a disordered microporous structure, b1: a global TEM showing the material which is calcined and has a mesoporous structure, b2: a global TEM showing the material which is calcined and has a mesoporous structure;
[0059] FIG. 5 is a particle size distribution statistical graph for a disordered microporous structure silicon dioxide material to which Peregal is added by using the method of the invention; it can be seen from this figure that the particle size of the resulting material in the invention is distributed within a narrow region, which demonstrates that the resulting particle size is very uniform;
[0060] FIG. 6 is a TEM for typical morphology for a disordered mesoporous silicon dioxide material manufactured by using the method of the invention;
[0061] FIG. 7 is a liquid nitrogen adsorption/desorption graph for a disordered microporous structure silicon dioxide material manufactured by using the method of the invention; and
[0062] FIG. 8 is a liquid nitrogen adsorption/desorption graph for a disordered mesoporous structure silicon dioxide material manufactured by using the method of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0063] For further illustrating the invention, experiments detailing a method for manufacturing a disordered porous silicon dioxide material are described below. It should be noted that the following examples are intended to describe and not to limit the invention.
Example 1
[0064] Deionized water, alcohol, and ammonia water are taken by volume of 1000:1750:310 mL to prepare a solvent. Tetraethyl orthosilicate, octadecyltrimethoxysilane, and Peregal O25 are weighed in the following amounts—7 grams:10 grams:6 grams, respectively, mixed and added to the solvent, and stirred continuously for 48 hours, then aged for 48 hours under RT, filtered with a filter paper, and then dried under RT for 48 hours. The grinded white powder is the silicon dioxide material with a long-chain alkyl and a disordered microporous structure as prepared. FIG. 4 shows in a1, a2 the TEM pictures of the material of this example in which the template has not been removed. In a1 of FIG. 4 , the global TEM picture may demonstrate that this material has an excellent mono-dispersity and remarkably uniform material particle size. During preparation the sample for TEM imaging of this material, only the ultrasonic vibration is conducted and no dispersing agent is used to help dispersing the material. In a2 of FIG. 1 , some local enlarged pictures are shown, indicating a particle size of about 100 nanometers.
Example 2
[0065] Deionized water, alcohol, and ammonia water are taken by volume of 400:750:120 mL to prepare a solvent. Tetraethyl orthosilicate, octadecyltrimethoxysilane, and Peregal O16 are weighed in the following amounts—7 grams:10 grams:6 grams respectively, mixed and added to the solvent, and stirred continuously for 48 hours, then aged for 48 hours under RT, filtered with a filter paper, and then dried under RT for 48 hours. The dried product is transferred to a crucible and then put into a muffle furnace, ramped in temperature at 3° C./min, and maintained at a temperature of 600° C. for 8 hours. After natural cooling, the resulting white powder is the mesoporous material as prepared. FIG. 4 shows in b1, b2 the TEM pictures of the mesoporous material of this example. In b1 of FIG. 4 , the global TEM picture may demonstrate that this material has an excellent mono-dispersity and remarkably uniform material particle size. During preparation the sample for TEM imaging of this material, only the ultrasonic vibration is conducted and no dispersing agent is used to help dispersing the material. In b2 of FIG. 4 , some local enlarged pictures are shown, indicating a particle size of about 100 nanometers. There are distinct irregular channels inside the material, but the pore size is also uniform.
Example 3
[0066] Deionized water, alcohol, ammonia water are taken by volume of 1000:1750:780 mL to prepare a solvent. Tetraethyl orthosilicate, hexadecyltrimethoxysilane, and Peregal O-10 are weighed in the following amounts—7 grams:9 grams:6 grams respectively, mixed and added to the solvent, and stirred continuously for 48 hours, then aged for 48 hours under RT, filtered with a filter paper, and then dried under RT for 48 hours. The grinded white powder the silicon dioxide material with a long-chain alkyl and with a microporous structure as prepared.
Example 4
[0067] Deionized water, alcohol, ammonia water are taken by volume of 1000:1750:780 mL to prepare the solvent. Tetraethyl orthosilicate, hexadecyltrimethoxysilane, and Peregal O25 are weighed in the following amounts—7 grams:9 grams:6 grams respectively, mixed and added to the solvent, and stirred continuously for 48 hours, then aged for 48 hours under RT, filtered with a filter paper, and then dried under RT for 48 hours. The dried product is transferred to a crucible and then put into a muffle furnace, ramped in temperature at 3° C./min, and maintained at a temperature of 600° C. for 8 hours. After natural cooling, the resulting white powder is the mesoporous material as prepared.
Example 5
[0068] Deionized water, alcohol, ammonia water are taken by volume of 1000:1750:780 mL to prepare the solvent. Tetraethyl orthosilicate, dodecyltrimethoxysilane, and Peregal O25 are weighed in the following amounts—7 grams:8 grams:6 grams respectively, mixed and added to the solvent, and stirred continuously for 48 hours, then aged for 48 hours under RT, filtered with a filter paper, and then dried under RT for 48 hours. The dried product is transferred to a crucible and then put into a muffle furnace, ramped in temperature at 3° C./min, and maintained at a temperature of 600° C. for 8 hours. After natural cooling, the resulting white powder is the mesoporous material as prepared.
Example 6
[0069] Deionized water, alcohol, hydrochloric acid are taken by volume of 1000:1750:920 mL to prepare the solvent. Tetraethyl orthosilicate, dodecyltrimethoxysilane, and Peregal O25 are weighed in the following amounts—7 grams:8.6 grams:6 grams respectively, mixed and added to the solvent, and stirred continuously for 48 hours, then aged for 48 hours under RT, filtered with a filter paper, and then dried under RT for 48 hours. The dried product is transferred to a crucible and then put into a muffle furnace, ramped in temperature at 3° C./min, and maintained at a temperature of 600° C. for 8 hours. After natural cooling, the resulting white powder is the mesoporous material as prepared.
Example 7
[0070] Deionized water, alcohol, ammonia water are taken by volume of 700:1250:215 mL to prepare the solvent. Tetraethyl orthosilicate, octadecyltrimethoxysilane, and Peregal O16 are weighed in the following amounts—7 grams:10 grams:6 grams respectively, mixed and added to the solvent, and stirred continuously for 48 hours, then aged for 48 hours under RT, filtered with a filter paper, and then dried under RT for 48 hours. The grinded white powder is the silicon dioxide material with a long-chain alkyl and with a microporous structure as prepared.
Example 8
[0071] This example is based on the method of Example 1, 2, or 3, except that the solvent in the raw material is added in advance into 30 mL nanometer ferroferric oxide magnetic fluid which has been subject to dispersion treatment and has a concentration of 30 milligram/mL. By calcining in the muffle furnace, and reducing by hydrogen at 600° C. for 10 hours, a material with embedded magnetic core and mesoporous shell is obtained.
Example 9
[0072] 3 grams tetraethyl orthosilicate is added in advance into a solvent of deionized water, alcohol, and ammonia water and hydrolyzes for 2 hours. Then the following steps are conducted in light of the method of Example 1, and the resulting core is a silicon dioxide material with a nanometer silicon sphere.
Example 10
[0073] This example is based on the method of Example 1, 2, or 3, and a powder mesoporous material is obtained. Then, 2 grams of the powder mesoporous material is soaked in a solution of 2 mol/l Fe 3+ and Fe 2+ slats, vibrated in a shaking table for 72 hours, separated by centrifugal separation, and then reduced by hydrogen at 600° C. for 10 hours. The resulting mesoporous silicon dioxide material contains magnetic particle in mesopores.
Example 11
[0074] This example is based on the method of Example 1, 2, or 3, except that after being stirred continuously for 12 hours, 2.6 mL amino silane such as APTES is added, and after RT drying, it is impossible to calcine to avoid being burnt away along with the amino group. It is only possible to apply extraction for removing the template and maintaining the amino group. As a result, the mesoporous silicon dioxide material grafted with amino is obtained.
Example 12
[0075] This example is based on the method of Example 1, 2, or 3, except that after being stirred continuously for 12 hours, sulfydryl silane such as 2.3 mL γ-mercaptopropyl tryi-ethyoxyl silane is added, and after RT drying, it is impossible to calcine to avoid being burnt away along with the amino group. It is only possible to apply extraction for removing the template and maintaining the amino group. As a result, the mesoporous silicon dioxide material grafted with sulfydryl is obtained.
Example 13
[0076] This example is based on the method of Example 1, 2, or 3, and a powder mesoporous material is obtained. Then, 3.3 grams of the material is subjected to ultrasonic dispersion in the reaction solvent such as dimethylbenzene. 3.5 mL Amino silane APTES is added, and is stirred continuously under temperature 120° C. for 48 hours. After filtering, washing, and drying, the mesoporous material descendent grafted with amino is obtained.
Example 14
[0077] This example is based on the method of Example 1, 2, or 3, and a powder mesoporous material is obtained. Then, 3.9 grams of the material is subjected to ultrasonic dispersion in the reaction solvent such as dimethylbenzene. 4.3 mL organic silicon source of γ-mercaptopropyl tri-ethyoxyl silane is added, and is stirred continuously under temperature 120° C. for 48 hours. After filtering, washing, and drying, the mesoporous material descendent grafted with sulfydryl is obtained.
[0078] While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A method for manufacturing a disordered porous silicon dioxide material including applying a fatty alcohol polyoxyethylene ether as an additive. The fatty alcohol polyoxyethylene ether has a formula of RO—(CH 2 CH 2 O) n —H, R is C 8-24 H 17-49 , and n=9-30. | 2 |
DESCRIPTION OF THE PRIOR ART
It is known from German specification No. 2,231,735 to provide a dental unit having a plurality of handpieces each mounted removably in a holder and provided with energy supply hoses or pipes leading into the unit. One or more of the handpieces is adapted to be driven by pressure air and one or more by electrical current, and the handpieces are adapted to be cut-in and out by a common starter, there being associated with each handpiece a switch operable upon extraction of the handpiece from its holder and which cuts-in in preparatory manner a supply of energy for the handpiece i.e. pressure air and/or electrical current. Thus, upon appropriate actuation of the common starter, the extracted handpiece i.e. the working handpiece, starts-up whereas the further handpieces which are disposed in their holders or extracted i.e. the inoperative handpieces, remain at a standstill.
The handpieces may be designed to be straight or angled, and conventionally the switches are arranged in or at the holders which are of for example "quiver" or sheath form.
In the known unit, the switches are designed as transmitters controlling logic-switched components connected sequentially of them, the component group of each transmitter being switched with (or linked to) the further component groups, for shutting down the inoperative handpieces when the working handpiece is extracted. With this arrangement, starting-up of the handpieces operated with different energies i.e. pressure air and also pressure water and electrical current, is prepared or programmed with the aid of electrical control means constituting the energy supply element, and this is extremely costly with reference to pressure air operated handpieces.
A similar dental unit is also known from German Auslegeschrift No. 2,038,976.
Finally, it is known from German Offenlegungsschrift No. 2,339,824, for individual control of handpieces operated by pressure air or electrical current, to provide a control block in each particular instance, and to assemble the said control blocks or units (corresponding in number to the number of handpieces) in close arrangement to constitute a control unit provided with a passage duct extending through all the control blocks and conveying the supply media for the handpieces, from which said passage duct there branches-off in each control block a branch duct into the flow path in which there is inserted a diaphragm or membrane associated with which is a control chamber provided on its side located opposite the incident-flow supply medium, which said control chamber is adapted to be subjected to the action, via a control line, of control pressure air for effecting blocking of the throughflow of the supply medium through the branch duct, there being provided in the control line a venting aperture which, in its open position, effects release of the supply medium throughflow through the branch duct. In the case of this known design, the said venting aperture is formed by the end of a venting line connected to the control line and extending as far as the holder of the particular handpiece. There, there is provided, a switch actuable by the handpiece on extraction out of or introduction into the holder, a closure valve adapted to be closed or sealed by the handpiece disposed in its inoperative position in the holder and, on the handpiece being removed, adapted to be opened by the air pressure building-up from a pressure air source. Thus, when the closure valve is opened, no control air flows to the control chamber.
In the case of this known design, the pneumatic control unit assembled from the individual control blocks has proved very satisfactory. However, the venting line connected to the control line of each individual control chamber and extending as far as the holder of the particular handpiece represents, with the closure valve associated with the end of each venting line, a relatively high structural outlay which nevertheless could be justified in the case of a dental unit having handpieces operated exclusively by pressure air.
It is an object of the invention to provide a dental unit of the type mentioned at the outset, i.e. having handpieces operated by pressure air and operated by electrical current, wherein the preparatory cutting-in or programming at least of starting-up of the pressure air driven handpieces, and also, in preferred development, the preparatory cutting-in or the feed of coolant or other supply pressure media both to the handpieces driven with pressure air and also to those driven with electrical current, is made possible using the known and well-tried pneumatic control unit, but avoiding a costly closure or sealing device for the venting aperture of the control lines.
SUMMARY OF THE INVENTION
According to the invention there is provided a dental unit comprising:
dental handpieces operable by pressure medium;
a holder for each handpiece;
a control unit operable to control the supply of pressure medium to each handpiece;
and switch means associated with each holder and with said control unit, each switch means being operable upon removal of the respective handpiece from its holder to initiate operation of the control unit for the supply of pressure medium to the handpiece;
in which the control unit comprises:
a control block corresponding to each handpiece;
a first passage extending through said control blocks and communicable with a supply of pressure medium for operating the handpieces;
a second passage in each control block communicable with said first passage for supplying pressure medium to the handpiece corresponding to the control block;
a diaphragm associated with each of said second passages and operable to control the communication between the respective second passage and said first passage;
a control chamber provided on one side of each diaphragm;
a control line communicable with each control chamber for supplying a control pressure medium to the control chamber thereby to operate the diaphragm to effect blocking of communication between said first passage and said second passage;
venting means communicating with each control line for discharging control pressure medium from the respective control chamber thereby to operate the diaphragm to permit communication between said first passage and said second passage when the venting means is open;
and an electrically operable closure device cooperable with each of said venting means, said closure device being controlled by one of said switch means in order to effect opening of the venting means when a respective handpiece is removed from its holder.
The operation of the closure device by the switch means, following removal of a particular handpiece from its holder, can, therefore, be employed for calling in a pre-programmed condition of the working handpiece, and also can effect blocking relative to the other inoperative handpieces.
By providing electrically operated closure devices, it is merely necessary to extend in each particular instance a simple exciter circuit comprising thin wires from the closure element to the switch means, instead of a voluminous control air venting line which is rigid and therefore liable to breakdown due to risk of crushing. Control of the closure element with the aid of an electrical current supplying the exciter circuit does not normally represent a supplementary outlay, because in the preferred embodiment the dental unit includes handpieces operated with pressure and also handpieces operated with electrical current, so that in any case it is connected to a source of electrical current.
The preparatory cutting-in or programming of starting-up of the handpieces operated with electrical current can be effected in known, simple manner, with the aid of electrical current supply elements or electrical control elements, but at the same time employing the above-mentioned exciter circuit.
A preferred design which is especially simple and space-saving comprises providing a venting aperture which is constituted by the open end of a venting line extending-out from a control line leading to the control chamber and projecting at its open end out of a free side wall of the control block, the closure element being arranged adjacent said open end.
One embodiment of the closure element may be provided by an electromagnetically actuable closure element constituted by a core made from magnetisable material and mounted to be displaceable in a stationary coil provided with an exciter winding, which said core is displaced, on excitation taking place, against the effect of a restoring spring, into a position releasing the venting aperture and, in the case of non-excitation, under the influence of the restoring spring into sealing abutment at the venting aperture.
A further embodiment is provided by an electromagnetically actuable closure element having a core made from magnetisable material and provided with an exciter coil, which said core extends parallel to and with spacing adjacent a lateral wall of the (square-form) control block, and is retained with one of its ends by a stationary strap made from magnetisable material, whereas the other end of the core is disposed, in the case of non-excitation, in spaced relationship relative to the free end of a one-armed lever made from magnetisable material and extending substantially transversely of the core, which said lever is so articulared to a stationary joint or hinge that the lever, on the core being excited, due to the magnetic attraction force of the latter, oscillates against the action of a restoring spring into sealing abutment at the venting aperture and, in the case of non-excitation of the core, under the influence of the restoring spring, swings back into the position releasing the venting aperture, the strap and the lever or the joint or articulation means thereof being connected by a component made from magnetisable material. With this arrangement, the component made from magnetisable material may be constituted by the control block itself, and in this case the strap and the lever joint may be arranged at the control block.
Furthermore, the electromagnetically actuable closure element may have a core made from magnetisable material and provided with an exciter winding, which said core extends parallel to and in spaced relationship adjacent to the lateral wall formed with the venting aperture of the square-form control block, and is secured with both its ends to two stationary straps made from magnetisable material and extending transversely of the core, which said straps end before the lateral wall of the control block, one of the two straps being provided at this end with a one-armed lever made from magnetisable material and pivotal about a joint, which said lever in the event of non-excitation of the core swings under the influence of a restoring spring into sealing abutment at the venting aperture and, on excitation of the core, swings-back against the action of the restoring spring into a position releasing the venting aperture.
Expediently, the electromagnetically actuable closure element is provided with a packing passing into abutment at the venting aperture.
The control unit can, apart from the passage duct conveying the driving pressure air for the handpieces driven by pressure air, also be provided with further passage ducts extending through all the control blocks, and conveying pressurised supply media such as cooling air, cooling water or the like, both for the handpieces driven by pressure air and also for those driven by electrical current, from which said further passage ducts there branches-off in the particular control block associated with each handpiece a branch duct connected with the energy supply hose of the particular handpiece and into the flow path of which there is inserted a diaphragm associated with which is a control chamber provided on its side opposite the incident-flow supply medium and connected with the control line of the remaining control chambers.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic illustration of a dental unit in accordance with the invention;
FIG. 2 is an exploded view of a control unit of the dental unit;
FIG. 3 is an exploded view of an alternative arrangement for a control block of the control unit shown in FIG. 2;
FIG. 4 is an enlarged sectional view of two adjacent control blocks of the control unit.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIG. 1, reference numeral 1 designates the apparatus stand or column of a dental device designed as a unit, at the other side of which, with the aid of a vertical shaft 2, a pivot arm 3 is mounted for pivotal movement in a horizontal plane. The pivot arm 3 has an arm extension 4 articulated to the pivot arm 3 so as to be pivotal in both a horizontal and also a vertical plane. Arranged in per se known manner at the forward end of the arm extension 4 is a receiving box 5 for substantially horizontally extractable dental handpieces 6, 7. The receiving box 5 is articulated to the free end of the arm extension 4 in such manner that it is always located in the horizontal position shown, independently of the relative pivoting positions of the arm 3 and extension 4.
FIG. 1 shows a starter 8, designed as a pedal starter and with the aid of which the handpieces 6, 7 can be cut-in and out. The handpieces 6, 7 are (as indicated for a typical handpiece 6 shown in FIG. 2) provided with energy supply hoses 11 debouching into holders 9, 10 of the receiving box 5 of the unit, and are mounted to be movable in and also extractable from the holders 9, 10. In the illustrated example, the handpieces 6 are adapted to be driven by pressure air and the handpieces 7 by electrical current. The handpieces 6 may be air turbine handpieces and/or air motor handpieces and the handpieces 7 may be handpieces having a built-in, miniature electrical motor.
The holders of the handpieces 6 (driven by compressed air) are designated 9 and the holders of the handpieces 7 (driven by electrical current) are designated 10. Turning to FIG. 2, one of the holders 9 is shown diagrammatically.
Associated with each handpiece 6, 7 is a switch 12 adapted to be tripped following removal of the handpiece from the holder 9, 10.
Referring to FIG. 2, there is shown only diagrammatically for a handpiece 6 operated by pressure air, a switch 12 which cuts-in in preparatory manner an energy supply element 13 for feeding driving pressure air to the handpiece 6 when extracted from its holder. On appropriate actuation of the starter, the extracted handpiece 6, i.e. the working handpiece, starts-up whereas the further handpieces disposed in their holders or extracted (i.e. the inoperative handpieces) remain at a standstill.
As FIGS. 2 and 3 show, the energy supply elements 13 for the handpieces 6 (operated by pressure air) each comprise a respective control block 14. Upper and lower control blocks 14 are assembled to form a control unit 18 having an input block 15 and an end block 16, by means of screws 17 which extend-through.
The control unit 18 is, referring to FIG. 2, formed with first passages in the form of passage ducts 19, 20, 21 extending from the input block 15 through the two control blocks 14 from below upwardly and carrying supply media for the handpieces 6 (or 7). The supply medium for the passage duct 19 passes through an input (or inlet) port stub 22, the supply medium for the passage duct 20 through an input port stub 23 and the supply medium for the passage duct 21 through the input port stub 24, into the input block 15. In use, the passage duct 19 may convey pressure air for driving the handpieces 6, the passage duct 20 may convey cooling water, and the passage duct 21 may convey cooling air, for example for forming a spray.
Disposed in each particular instance between the two control blocks 14 and also between the lower control block 14 and the end block 15 and the upper control block 14 and the input block 16 is, for sealing purposes, a respective diaphragm 25 formed with apertures a, b, c for the passage ducts 19, 20, 21.
In each of the two control blocks 14, there branches-off in each particular instance from the passage ducts 19, 20, 21 second passages in the form of a branch duct 19', 20', 21', which, according to FIG. 2, is connected with the energy supply hose 11 of the associated handpiece 6, the starter 8 (FIG. 1) being interposed (in a manner not shown) upstream of the handpiece 6.
As will be clear in particular from FIG. 4, which illustrates the path of the branch line 19' through either one of the blocks 14, the diaphragm 25 is connected in the flow path of the branch duct 19'. On the side remote from the branch duct 19', i.e. on the side of the diaphragm 25 located opposite the incident-flow pressure medium, there is a control chamber 26 adapted to be subjected to the action of pressure air (control pressure medium) by means of a pressure air control line 27' connected to a pressure air source 27. Arranged in the control line 27' is also a throttle 27".
A respective diaphragm 25 is simultaneously arranged as a packing or seal between each of the adjacent blocks 15 and 14, 14 and 14, and 14 and 16.
Referring to FIGS. 2 to 4, the control chamber 26 is in each instance provided in the upper one of the blocks 14 or the block 16, whereas there is provided on the side of the diaphragm 25 located opposite the control chamber 26, in both the upper and the lower block 14, a valve chamber 28 which is open towards the diaphragm 25 and which has a seat 29 for a freely displaceable valve body 30 actuable in the closure sense by the diaphragm 25.
The valve chamber 28 in the upper block 14 co-operates with one side of the diaphragm 25 between the upper block 14 and the block 16, whereas the control chamber 26 in block 16 co-operates with the other side of the diaphragm 25. Similarly, the control chamber 26 in the upper block 14 co-operates with one side of the diaphragm 25 between the upper and lower blocks 14, whereas the valve chamber 28 in the lower block 14 co-operates with the other side of the diaphragm.
The valve body or valve member 30 is designed as a valve disc and has a guide shaft 31 extending into the "arriving" element 19" of the branch duct 19'. Provided below the valve body 30 designed as a valve disc is a sealing ring 32. Furthermore, there is associated with the valve body 30 a compression spring 33 acting on it in a direction away from the valve seat 29.
The portion of each branch duct 19', 20', 21' extending away from the valve chamber 28 and connected with the energy supply hose 11 of the particular handpiece is designated 19'", 20'", 21'".
It is furthermore apparent from FIGS. 2 and 3 that a venting aperture 34 of each control chamber 26 has associated with it an electromagnetically actuable closure element 35 having an exciter circuit 36 which is controlled by the particular switch 12 associated with each handpiece. In FIG. 2, only one handpiece 6 is shown, which is associated with upper block 14. Also, the switch 12 shown in FIG. 2 controls the closure element 35 which is associated with end block 16. The switch 12 is designed as a switch moveable to close or to interrupt the exciter circuit 36. When the handpiece 6 is out of the holder 9, the switching element 12' is loaded so that it passes into abutment at the switching contact 12" and the switch 12, and therewith the exciter circuit 36, is closed. FIG. 2 also shows a closure element 35 associated with a venting aperture 34 of upper block 14, the closure element being controlled by a switch (not shown) which functions in an opposite manner to the switch 12 associated with end block 16. The switch (not shown) is operated by the handpiece 6 (also not shown) associated with lower block 14, but in opposite manner in that the respective circuit 36 is de-energised by opening of the switch when the handpiece is removed from its holder 9.
Each venting aperture 34 is, as FIGS. 2 and 3 show, constituted by the open end of a venting line 37 extending away from a control line 27 communicating with the control chamber 26. Through the agency of its open end, the venting line 37 projects out of a free side wall 38 of the upper control block 14 or of the end block 16, the electromagnetically actuable closure element 35 being arranged in front of this open end.
Referring to FIG. 2, the closure element 35 associated with the end block 16 serves to control the communication between the branch ducts 19', 20', 21' and their outward extensions 19'", 20'", 21'" of the upper control block 14, whereas the closure element 35 associated with the upper control block 14 serves similarly to control communication in the lower control block 14. Two embodiments of closure members 35 for end block 16 are shown in FIGS. 2 and 3, and one embodiment for upper block 14 is shown in FIG. 2.
The electromagnetically actuable closure element 35 associated in FIG. 2 with the end block 16 is constituted directly by a core 41 made from magnetisable material and mounted to be displaceable in a stationary coil 40 provided with an exciter winding 39. On excitation of the winding 39, the core 41 travels against the action of a restoring spring 42 designed as a compression spring into a position releasing the venting aperture 34 and, in the case of non-excitation, it travels under the action of the restoring spring 42 into sealing abutment at the venting aperture 34.
The electromagnetically actuable closure element 35 which, referring to FIG. 2, is associated with the upper control block 14, has a core 41 made from magnetisable material and provided with an exciter winding 39. The core 41 which is designed to be of rod-form extends parallel to and in spaced relationship adjacent a side wall 43 of the square-form control block 14. Through the agency of one of its ends, the core 41 is retained by a strap 44 secured to be stationary at the control block 14 and made from magnetisable material, whereas the other end of the core 41 (on non-excitation of the winding 39) extends in spaced relationship relative to the free end 45 of a one-armed lever 46 made from magnetisable material and extending substantially transversely of the core. The lever 46 is pivoted to a stationary articulation means 47 in such a way that, on excitation of the winding 39 or of the core 41, due to the magnetic attraction force of the latter, against the action of a restoring spring 42 designed as a compression spring, it pivots into sealing abutment against the venting aperture 34. In the event of non-excitation of the core 41, the lever 46 swings, under the influence of the restoring spring 42, back into the position freeing the venting aperture 34, the strap 44 and the lever 46 of the articulation means 47 thereof being connected by a component made from magnetisable material.
The last-mentioned component is, in the case of the example of embodiment described, constituted by the control block 14 itself which, in this case, is made from magnetisable material, and as already stated the strap 44 and the articulation means 47 of the lever 46 or the carrier 47' therefor are secured to the control block 14. The component can (in a manner not shown) be constituted by a yoke connecting the strap 44 with the carrier 47 secured to the control block.
The alternative closure element 35 (shown in FIG. 3) associated with the end block 16 has, again, a core 41 made from magnetisable material and provided with an exciter winding 39. The core 41 extends parallel to and in spaced relationship adjacent the lateral wall 38, formed with the venting aperture 34, of the square-form end block 16. Through the agency of its two ends, the core 41 is secured to two straps 48, 49 made from magnetisable material and extending transversely of the core. The straps 48, 49 terminate in spaced relationship a short distance before the lateral wall 38 of the end block 16. The left-hand strap 48 in FIG. 3 is, at the end disposed in spaced relationship before the lateral wall 38, provided with a one-armed lever 51 made from magnetisable material and pivotal about a hinge or joint 50. The lever 51 pivots, in the event of non-excitation of the core 41, under the influence of a restoring spring 42 designed as a compression spring, into sealing abutment at the venting aperture 34. In the event of excitation of the core 41, the lever 51 pivots, against the action of the restoring spring 42, back into a position wherein it frees the venting aperture 34.
The lever 46 in FIG. 2 and also the lever 51 in FIG. 3 is provided with a packing 52 passing into abutment at the venting aperture 34. Also the end of the core 41 facing the end block 16 (in the upper view according to FIG. 2) can be provided with such a packing.
As will be evident from FIG. 4, which illustrates the arrangement of a control chamber 26 on one side of a diaphragm 25 (with respect to end block 16 and upper block 14, or upper block 14 and lower block 14) the supply of control pressure medium to the chamber 26 will result in downward movement of the piston 30 so that seal 32 engages the seat 29 and thereby interrupts communication between the first passage (19,20,21) and the outlets (19'", 20'", 21'") to the handpieces 6. When one of the handpieces 6 is removed from its holder 9, the respective switch (12) controls the circuit 36 so that the chamber 26 can be vented via the venting aperture 34 which is now opened by the closure element 34. This then enables the piston 30 to move upwardly to establish communication between the "first passage" and the appropriate outlet to the handpiece so that the latter can receive a supply of pressure medium when the starter 8 is operated.
The control unit 18 can, apart from the passage duct 19 conveying the driving pressure air for the handpieces 6 driven by pressure air, and apart from the passage ducts 20, 21 conveying supply media such as cooling air, cooling water, hot water or the like for the said handpieces 6, also be provided with further passage ducts (not shown) for conveying supply media of the type mentioned for the handpieces 7 driven by electrical current, a supplementary control block being provided for each of these handpieces 7. These supplementary control blocks may be combined to a separate control unit. The aforementioned, further passage duct (not shown) then also have in the individual control blocks branch ducts which, with reference to preparatory cut-in of inflow of the supply media conveyed in them to the handpieces 7, are designed in the same manner as in the case of the embodiments according to FIGS. 2 to 4. | A dental unit having pressure-medium operated handpieces, a holder for each handpiece, a control unit operable to control the supply of pressure medium to each handpiece, and switch means associated with each holder and with said control unit, each switch means being operable upon removal of the respective handpiece from its holder to initiate operation of the control unit for the supply of pressure medium to the handpiece.
The control unit comprises a control block corresponding to each handpiece, a first passage extending through the control blocks to supply pressure medium for operating the handpieces, a second passage in each control block communicating with a respective handpiece, a diaphragm controlling the communication between the first passage and each second passage, a control chamber controlling the operation of the diaphragm, the control chamber being charged with control pressure medium in order to move the diaphragm to a position blocking communication between the first passage and the respective second passage, a venting arrangement for venting each control chamber, and an electrically operated closure element cooperating with each venting arrangement, the closure element being controlled by the respective switch means in order to vent the control chamber when one of the handpieces is removed from its holder so that the handpiece is ready to be supplied with pressure medium via the first passage and the second passage. | 0 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a piezoelectric element formation member comprising piezoelectric material layer which are deformable in accordance with the application of voltages, and a method of manufacturing such a piezoelectric element formation member. The present invention also relates to a piezoelectric actuator unit in which piezoelectric elements are arrayed and integrated with each other. The present invention also relates to a liquid ejection head incorporating such a piezoelectric actuator unit. For example, the present invention is directed to an ink jet recording head in which pressure fluctuation is caused to ink in pressure generating chambers by the piezoelectric elements to eject ink droplets from nozzle orifices.
[0002] It is known an ink jet recording head comprising a piezoelectric actuator unit of longitudinal vibration mode, wherein the piezoelectric elements are extended or shrunk in the axial direction thereof. In such a recording head, an actuation plate constitutes a part of the pressure generating chambers communicated with the nozzle orifices, so that the piezoelectric elements are deformed so as to actuate the actuation plate to generate the pressure fluctuation.
[0003] Japanese Patent Publication No. 11-10875A discloses such a piezoelectric actuator unit. As shown in FIGS. 8A and 8B, the piezoelectric actuator unit comprises a actuator array 19 and a fixation board 15 for supporting the actuator array 19 . In the actuator array 19 , a plurality of piezoelectric elements 14 are arrayed. Each of the piezoelectric elements 14 is a lamination type element in which internal common electrodes 11 and internal segment electrodes 12 are alternately laminated while sandwiching piezoelectric material layers 13 therebetween. The internal common electrodes are exposed to a rear end face of the actuator array 19 , and the internal segment electrodes 12 are exposed to a front end face of the actuator array 19 . On outer faces of the actuator array 19 , there are formed external segment electrodes 16 electrically connected to the internal segment electrodes 12 , and an external common electrode 17 electrically connected to the internal common electrodes 11 . Terminals of a flexible cable 18 are mounted on contact portions of the external segment electrodes 16 and the external common electrodes 17 by soldering or the like.
[0004] Such a piezoelectric actuator unit is generally manufactured as explained below.
[0005] First, as shown in FIGS. 9A and 9B, a piezoelectric element formation member 23 is prepared. Specifically, the piezoelectric element formation member 23 is formed by alternately laminating conductive layers 21 to be the internal common electrodes 11 and conductive layers 20 to be the internal segment electrodes 12 while sandwiching piezoelectric material layers 22 therebetween, and then subjected to a drying process and a baking process. More specifically, the conductive layers 21 are exposed to a rear end face of the piezoelectric element formation member 23 and extended to the vicinity of a front end face thereof. On the other hand, the conductive layers 22 are exposed to the front end face of the piezoelectric element formation member 23 .
[0006] Next, a mask 24 is placed on parts in a top face of the piezoelectric element formation member 23 where are to be boundaries of the external segment electrodes 16 and the external common electrode 17 and where to be dummy actuators (described later) arranged in both side ends of the actuator array 19 . The mask 24 is thus generally U-shaped.
[0007] Next, as shown in FIGS. 10A and 10B, conductive material is vapor-deposited on outer faces of the piezoelectric element formation member 23 except side faces and a bottom face thereof, to form the external segment electrodes 16 and the external common electrode. 17 . The mask 24 is removed after the completion of the vapor deposition.
[0008] Next, a non-active region of the piezoelectric element formation member 23 in which only the internal common electrodes 11 and the piezoelectric material layers 13 are laminated (see FIG. 10B) is placed on the fixation board 15 made of, for example, metal and fixed thereon by adhesive agent.
[0009] After then, slits 25 are formed by cutter such as a dicing saw and a wire saw (not shown) so as to extend from the front end of the piezoelectric element formation member 23 to at least rear ends of the internal common electrodes 12 , so that regions to be active regions of the piezoelectric elements 14 are pectinated. Incidentally, at the both side ends of the pectinated piezoelectric elements 14 , a pair of dummy actuators having a larger width than that of each piezoelectric element 14 are formed.
[0010] In the above method, the external segment electrodes 16 and the external common electrode 17 are finished by executing a single vapor deposition process under such a condition that the mask 24 is provided on their boundaries. The external segment electrodes 16 and the external common electrode 17 must be electrically insulated because the piezoelectric action cannot be performed if both electrodes are electrically connected.
[0011] Recently, in view of the cost problem or the like, it is a trend that a portion which is not directly involved with the piezoelectric action is so designed as to have a smaller dimension. That is, the mask 24 is subjected to such downsizing. In such a case, the width of the mask 24 is narrowed and the stiffness thereof is lowered. Accordingly, the downsized mask 24 is likely to be flexed during the vapor deposition, so that a gap is formed between the surface of the piezoelectric element formation member 23 and the mask 24 . If the conductive material enters the gap, the external segment electrodes 16 and the external common electrode 17 are electrically connected in the worst case. Such a gap is likely to be formed at a center portion of the mask 24 in the arrayed direction of the piezoelectric elements 14 .
[0012] In the piezoelectric actuator unit, the contact portions of the external common electrode 17 with respect to the terminal of the flexible cable 18 are arranged at regions which are outer than the region where the external segment electrodes 16 are formed in the arrayed direction of the piezoelectric elements 14 , because the contact portions must be arranged so as to avoid the wirings connected to the external segment electrodes 16 . For this reason, it is not necessary to make the width of the external common electrode 17 uniform entirely as shown in FIG. 10A only if the contact portions for the flexible cable 18 are secured. In other words, the external common electrode 17 is formed even in unnecessary portions. Further, severe tolerance is imparted to a part the mask 24 corresponding to such an unnecessary portion.
[0013] These problems may occur not only in ink jet recording heads, but also similarly occur in other liquid ejection heads for ejecting liquid other than ink.
SUMMARY OF THE INVENTION
[0014] It is therefore an object of the invention to provide a piezoelectric element formation member advantageous to the downsizing requirement and the yield enhancement, by providing an external electrode at a functionally proper portion to alleviate the tolerance requirement.
[0015] It is also an object of the invention to provide a method of manufacturing such a piezoelectric element formation member.
[0016] It is also an object of the invention to provide a piezoelectric actuator unit and a liquid ejection head incorporating such a piezoelectric element formation member.
[0017] In order to achieve the above objects, according to the invention, there is provided a piezoelectric element formation member, comprising:
[0018] a substrate, in which first internal electrode layers and second internal electrode layers are alternately laminated while sandwiching piezoelectric material layer therebetween, the first internal electrode layers being exposed to a first end face of the substrate, and the second internal electrode layers being exposed to a second end face of the substrate which is opposite to the first end face;
[0019] a first external electrode layer formed on the first end face and a third end face connecting the first end face and the second end face, the first external electrode layer being electrically connected to the first internal electrode layers; and
[0020] a second external electrode layer formed on the second end face and the third end face, the second external electrode layer being electrically connected to the second internal electrode layers, and being electrically independent from the first external electrode layer, wherein:
[0021] the first external electrode layer and the first internal electrode layers are to be divided by slits extending from the first end face to form a plurality of piezoelectric elements arrayed in a first direction; and
[0022] the second external electrode layer includes:
[0023] a pair of first sections provided on both end portions of the third end face in the first direction, and having a first dimension in a second direction perpendicular to the first direction; and
[0024] a second section provided between the first sections, and having a second dimension in the second direction which is less than the first dimension.
[0025] In order to form the above second external electrode layer, a mask having a widened portion corresponding to the narrowed second section is used when the external electrode layers are formed through the vapor deposition. Accordingly, the stiffness of the mask can be secured so that the undesired flexure during the vapor deposition is prevented even if the portion which is not involved with the piezoelectric action is downsized. Further, since the area of the unnecessary part of the second external electrode layer is reduced, it is advantageous to the cost reduction and the downsizing.
[0026] Preferably, the second dimension is substantially zero. In this case, the stiffness of the mask is further enhanced.
[0027] Preferably, a dimension of the second section in the first direction is greater than a dimension in the first direction of a region where the first external electrode layer is formed.
[0028] In such a configuration, a certain length between the external electrode layers can be secured.
[0029] Preferably, the first sections and the second section are connected in a stepwise manner.
[0030] Alternatively, it is preferable that the first sections and the second section are connected by third portions each dimension in the second direction of which is gradually varied from the first dimension to the second dimension.
[0031] According to the invention, there is also provided a method of manufacturing a piezoelectric element formation member, comprising steps of:
[0032] preparing a substrate, in which first internal electrode layers and second internal electrode layers are alternately laminated while sandwiching piezoelectric material layer therebetween, the first internal electrode layers being exposed to a first end face of the substrate, and the second internal electrode layers being exposed to a second end face of the substrate which is opposite to the first end face;
[0033] placing a mask on a third end face of the substrate which connects the first end face and the second end face; and
[0034] depositing conductive material on the masked substrate such that a first external electrode layer is formed on the first end face and the third end face, and a second external electrode layer is formed on the second end face and the third end face, and such that the second external electrode layer is made electrically independent from the first external electrode layer, wherein:
[0035] the first external electrode layer and the first internal electrode layers are to be divided by slits extending from the first end face to form a plurality of piezoelectric elements arrayed in a first direction; and
[0036] the mask is configured such that the second external electrode layer includes:
[0037] a pair of first sections provided on both end portions of the third end face in the first direction, and having a first dimension in a second direction perpendicular to the first direction; and
[0038] a second section provided between the first sections, and having a second dimension in the second direction which is less than the first dimension.
[0039] Preferably, the mask is configured such that the second dimension is substantially zero.
[0040] Preferably, the mask is configured such that a dimension of the second section in the first direction is greater than a dimension in the first direction of a region where the first external electrode layer is formed.
[0041] Preferably, the mask is configured such that the first sections and the second section are connected in a stepwise manner.
[0042] Alternatively, it is preferable that the mask is configured such that the first sections and the second section are connected by third portions each dimension in the second direction of which is gradually varied from the first dimension to the second dimension.
[0043] Preferably, the mask is configured such that a plurality of piezoelectric formation members each of which is described the above are simultaneously formed.
[0044] In such a configuration, the vapor deposition can be precisely executed even when a plurality of piezoelectric element formation members are simultaneously manufactured.
[0045] According to the invention, there is also provided a piezoelectric actuator unit, wherein a fourth end face opposite to the third end face of the above piezoelectric element formation member is joined to a fixation board in a cantilevered manner, such that a portion of the piezoelectric element formation member closer to the first end face becomes a free end.
[0046] Preferably, the slits are extended to at least an end of the first external electrode layer formed on the third end face and closer to the second end face.
[0047] According to the invention, there is also provided a liquid ejection head, comprising:
[0048] the above piezoelectric actuator unit;
[0049] a drive wiring, comprising a plurality of electrodes electrically connected, through contacts, to the divided ones of the first external electrode layer and the second external electrode layer, to supply signals for driving the piezoelectric elements; and
[0050] a vibration plate, which forms a part of each of pressure generating chambers communicated with a nozzle orifice from which an ink droplet is ejected,
[0051] wherein the second external electrode layer is electrically connected to at least two of the electrodes in the drive wiring via the first sections thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:
[0053] [0053]FIG. 1A is a perspective view of a piezoelectric actuator unit according to a first embodiment of the invention;
[0054] [0054]FIG. 1B is a side view of the piezoelectric actuator unit of FIG. 1A;
[0055] [0055]FIG. 2 is a section view of a liquid ejection head incorporating the piezoelectric actuator unit of FIG. 1A;
[0056] [0056]FIGS. 3A and 4A are plan views showing how to manufacture the piezoelectric actuator unit of FIG. 1A;
[0057] [0057]FIGS. 3B and 4B are side views showing how to manufacture the piezoelectric actuator unit of FIG. 1A;
[0058] [0058]FIG. 4C is a rear side view showing how to manufacture the piezoelectric actuator unit of FIG. 1A;
[0059] [0059]FIG. 5 is a perspective view of a piezoelectric actuator unit according to a second embodiment of the invention;
[0060] [0060]FIG. 6 is a perspective view of a piezoelectric actuator unit according to a third embodiment of the invention;
[0061] [0061]FIG. 7 is a plan view showing how to manufacture a plurality of piezoelectric actuator units of the invention;
[0062] [0062]FIG. 8A is a plan view of a related-art piezoelectric actuator unit;
[0063] [0063]FIG. 8B is a side view of the piezoelectric actuator unit of FIG. 8A;
[0064] [0064]FIGS. 9A and 10A are plan views showing how to manufacture the piezoelectric actuator unit of FIG. 8A; and
[0065] [0065]FIGS. 9B and 10B are side views showing how to manufacture the piezoelectric actuator unit of FIG. 8A.
DETAILED DESCRIPTION OF THE INVENTION
[0066] Preferred embodiments of the invention will be described below in detail with reference to the accompanying drawings. Members which are substantially the same as the related-art configuration shown in FIGS. 8A through 10B are designated by the same reference numerals.
[0067] As shown in FIGS. 1A and 1B, a piezoelectric actuator unit 1 according to a first embodiment of the invention comprises a piezoelectric element formation member 23 and a fixation board for supporting the piezoelectric element formation member 23 thereon in a cantilevered manner. This piezoelectric actuator unit 1 is assembled in a liquid ejection head such as an ink jet recording head.
[0068] The piezoelectric element formation member 23 is formed by alternately laminating internal electrodes serving as two poles in a piezoelectric element 14 with piezoelectric material layers 13 . Specifically, internal segment electrodes 12 to be segment electrodes each of which is electrically independent from an adjacent piezoelectric actuator, and internal common electrodes 11 to be a common electrode which is common to the respective piezoelectric actuators are alternately laminated while sandwiching the piezoelectric material layers 13 therebetween.
[0069] A plurality of slits 25 are formed in the piezoelectric element formation member 23 by a wire saw or the like. Each of the slits 25 is extended from the front end of the piezoelectric element formation member 23 at which the internal segment electrodes 12 to the rear ends of the internal segment electrodes 12 . The front end portion of the piezoelectric element formation member 23 is pectinated by the slits 25 to form a plurality of arrayed piezoelectric elements 14 . The bottom of each slit 25 is a slope as indicated by a dashed line shown in FIG. 1B.
[0070] At both side ends of the arrayed piezoelectric elements 14 , a pair of dummy actuators 26 are formed so as to have a width wider than that of each piezoelectric element 14 . The dummy actuators are not involved with the piezoelectric action for the liquid ejection, but serve as members for precisely positioning the piezoelectric actuator unit 1 when it is assembled in the liquid ejection head.
[0071] A region where the internal segment electrodes 12 , the internal common electrodes 11 and the piezoelectric material layers 13 are laminated becomes an active region of the piezoelectric element 14 . When voltage is applied between the internal segment electrodes 12 and the internal common electrodes 11 , the piezoelectric material layers 13 deforms so that the piezoelectric element 14 extends or shrinks in the axial direction thereof. On the other hand, a region where the internal segment electrodes 12 are not provided becomes a non-active region which is not involved with the piezoelectric action and is fixed on the fixation board 15 .
[0072] The internal segment electrodes 12 are exposed at a front end face of the piezoelectric element formation member 23 and electrically connected with external segment electrodes 16 describe later. On the other hand, the internal common electrodes 11 are exposed at a rear end face of the piezoelectric element formation member 23 and electrically connected with an external common electrodes 19 . The internal common electrodes 11 are extended to the vicinity of the front end face of the piezoelectric element formation member 23 .
[0073] Each of the external segment electrodes 16 is extended from the top face to the front end face of the piezoelectric element formation member 23 , and electrically connected with a flexible cable 18 at the top face of he piezoelectric element formation member 23 .
[0074] The external common electrodes 19 is extended from the top face to the rear end face of the piezoelectric element formation member 23 .
[0075] At the boundaries between the external segment electrodes 16 and the external common electrodes 19 , a no-electrode region 9 is formed so as to extend in the arrayed direction of the piezoelectric elements 14 . Further, no-electrode regions 5 are formed at both widthwise ends of the top face of the piezoelectric element formation member 23 so as to continue to the no-electrode region 9 .
[0076] A part of the no-electrode region 9 opposing to the external segment electrodes 16 is widened toward the rear end of the piezoelectric element formation member 23 . This widened portion of the no-electrode region 9 defines widened portions 2 of the external common electrode 19 at the both widthwise ends of the top face of the piezoelectric element formation member 23 . In other words, at the top face of the piezoelectric element formation member 23 , the external common electrode 19 has the widened portions 2 and a narrowed portion 3 formed therebetween. A dimension of each widened portion 2 in the longitudinal direction of the piezoelectric element 14 is larger than that of the narrowed portion 3 .
[0077] An interval between the widened portions 2 , that is, a dimension of the no-electrode region 9 defining the widened portions 2 and the narrowed portion 3 in the arrayed direction of the piezoelectric elements 14 is wider than a dimension in the arrayed direction of the region where the external segment electrodes 16 are formed. The external common electrode 19 is electrically connected to the flexible cable 18 at the widened portions 2 .
[0078] In the flexible cable 18 , a plurality of printed wirings are arrayed along the arrayed direction of the piezoelectric elements 14 . Wirings at both widthwise ends of the flexible cable 18 are electrically connected to the internal common electrodes 11 via the widened portions 2 of the external common electrode 19 . On the other hand, wirings between the above wirings at both widthwise ends are electrically connected to the internal segment electrodes 12 via the external segment electrodes 16 . In such a configuration, drive signals (voltages) are applied to the respective piezoelectric elements 14 through the flexible cable 18 .
[0079] [0079]FIG. 2 shows one example of a liquid ejection head 10 incorporating the above piezoelectric actuator unit 1 .
[0080] The liquid ejection head 10 is constituted by joining a flow passage unit 33 formed with nozzles 31 and pressure generating chambers 32 with a head case 35 accommodating the piezoelectric actuator unit 1 .
[0081] The flow passage unit 33 is formed by laminating: a nozzle plate 36 formed with the nozzles 31 ; a flow passage formation plate 44 in which opened spaces to be the pressure generating chambers 32 , a common reservoir 37 and liquid supply paths 38 communicating the chambers 32 to the reservoir 37 are formed; and an actuation plate 40 which closes the opened space of the flow passage formation plate 44 .
[0082] The piezoelectric element 14 shrinks in the axial (longitudinal) direction thereof when it is charged, whereas it extends when it is discharged. The front ends (free ends) of the piezoelectric elements 14 are fixed on island portions 40 A of the actuation plate 40 to vary the volume of the pressure generating chamber 32 .
[0083] In accordance with the extension or shrinkage of the piezoelectric elements 14 , the pressure generating chambers 32 are expanded or contracted to generate pressure fluctuation in liquid contained in the pressure generating chambers 32 , thereby pulling liquid from the reservoir 37 or ejecting liquid from the nozzles 31 .
[0084] The head case 35 is formed with a liquid supply passage 34 for introducing liquid such as ink to the reservoir 37 . A liquid supply tube 43 is formed at the end of the liquid supply passage 34 .
[0085] Next, there will be described how to manufacture the above piezoelectric actuator unit 1 .
[0086] First, as shown in FIGS. 3A and 3B, the piezoelectric element formation member 23 in which the internal segment electrodes 12 and the internal common electrodes 11 are alternately laminated while sandwiching the piezoelectric material layers 13 is prepared. More specifically, conductive material sheets to be the internal segment electrodes 12 and conductive material sheets to be the internal common electrodes 11 are alternately laminated while sandwiching piezoelectric material sheets such as titanate lead zirconate (PZT) to be the piezoelectric material layers 13 therebetween. The laminated structure is then subjected to a baking process. In this state, the internal segment electrodes 12 are exposed to the front end face of the piezoelectric element formation member 23 to be the free end, while the internal common electrodes 11 are exposed to the rear end face of the piezoelectric element formation member 23 to be the fixed end.
[0087] Next, a mask 4 made of stainless steel or the like is placed on the top face of the piezoelectric element formation member 23 . The mask 4 has a band section 7 for forming the no-electrode region 9 between the regions to be the external segment electrodes 16 and the external common electrode 19 . The band section 7 extends in the arrayed direction of the piezoelectric elements 14 and has a protruded portion 6 protruded toward the rear end of the piezoelectric element formation member 23 .
[0088] The mask 4 has side end portions 27 which are continued from both ends of the band section 7 to the front end of the piezoelectric element formation member 23 via the both widthwise end portions thereof. An interval between the side end portions 27 in the arrayed direction of the piezoelectric elements 14 is made smaller than a dimension of the protruded portion 6 in the arrayed direction of the piezoelectric elements 14 .
[0089] Next, as shown in FIGS. 4A and 4B, in a condition that the mask 4 is placed on the top face of the piezoelectric element formation member 23 , conductive material such as chromium, nickel, gold, platinum, copper or the like is deposited, so that the external segment electrodes 16 and the external common electrode 19 are formed at portions where are not covered with the mask 4 , while the no-electrode regions 5 , 9 are formed at portions where are covered with the mask 4 .
[0090] The thus formed external common electrode 19 has the above described widened portions 2 and the narrowed portion 3 . As shown in FIG. 4B, the external segment electrodes 16 are extended from the top face to the front end face of the piezoelectric element formation member 23 and electrically connected to the exposed internal segment electrodes 12 . As shown in FIGS. 4B and 4C, the external common electrode 19 is extended from the top face to the rear end face of the piezoelectric element formation member 23 and electrically connected to the exposed internal common electrodes 11 .
[0091] After the non-active region of the piezoelectric element formation member 23 is fixed on the fixation board 15 , the slits 25 are formed by the wire saw or the like to form the pectinated piezoelectric elements 14 as shown in FIGS. 1A and 1B.
[0092] In this embodiment, since the external common electrode 19 on the top face of the piezoelectric element formation member 23 is configured to have the widened portions 2 and the narrowed portion 3 , the mask 4 for forming the no-electrode region 9 is formed with the protruded portion 6 .
[0093] Thus, the stiffness of the mask 4 is enhanced, so that the undesired flexure of the mask 4 during the vapor deposition process can be avoided. The trouble that the deposited conductive material enters the gap formed by the flexure can be accordingly prevented. Therefore, even if the non-active region is subjected to the downsizing, the stiffness of the mask 4 can be maintained, thereby enhancing the yield.
[0094] In this embodiment, the external common electrode 19 is electrically connected with the flexible cable 18 via the widened portions 2 . The portion where is not used as the contact portions for the flexible cable 18 is provided as the narrowed portion 3 . In other words, the external common electrode 19 is not formed at the unnecessary portion. Further, since the protruded portion 6 is relatively wide, the severe tolerance is not required for the mask 4 .
[0095] In this embodiment, the interval between the widened portions 2 in the arrayed direction of the piezoelectric elements 14 is wider than the dimension of the region where the external segment electrodes 16 are formed in the arrayed direction of the piezoelectric elements 14 . Accordingly, a certain distance between both of the external electrodes can be secured, so that the stiffness of the mask 4 can be secured. Further, a space for a reinforcing jig or the like can be secured on the mask 4 .
[0096] [0096]FIG. 5 shows a piezoelectric actuator unit according to a second embodiment of the present invention.
[0097] In this embodiment, the band section 7 of the mask 4 is formed with a protruded portion 6 which extends to the rear end of the piezoelectric element formation member 23 . Accordingly, the narrowed portion 3 of the external common electrode 19 is formed as a region which is provided on the rear end face of the piezoelectric element formation member 23 , but is not provided on the top face thereof.
[0098] In such a configuration, the stiffness of the band section 7 is further enhanced, while further reducing the area of the unnecessary part of the external common electrode 19 .
[0099] [0099]FIG. 6 shows a piezoelectric actuator unit according to a third embodiment of the present invention.
[0100] In this embodiment, the widened portions 2 and the narrowed portion 3 are connected via portions 41 at which the width of the external common electrode 19 in the longitudinal direction of the piezoelectric element 14 is gradually varied. FIG. 6 show an example that the width at the portion 41 is linearly varied. However, the portion 41 may have a curved edge.
[0101] In this embodiment, the largest interval between the widened portions 2 in the arrayed direction of the piezoelectric elements 14 is made larger than the dimension of the region where the external segment electrodes 16 are formed in the arrayed direction of the piezoelectric elements 14 .
[0102] In such a configuration, the area of the contact portions of the external common electrode 19 with respect to the flexible cable 18 can be enlarged, so that the tolerance requirement for parts of the mask 4 for forming the contact portions can be alleviated. Any other attained advantages are the same as discussed with the above embodiments.
[0103] [0103]FIG. 7 shows how to manufacture a plurality of piezoelectric actuator units simultaneously. Specifically, a plurality of piezoelectric element formation members 23 explained in the first embodiment are arrayed such that the rear end face (lower side in the figure) of one formation member 23 faces the front end face (upper side in the figure) of adjacent one formation member 23 . In this example, three formation members 23 are arrayed.
[0104] A mask 28 covers simultaneously the arrayed piezoelectric element formation members 23 . The mask 28 is formed with first openings 29 for forming the external segment electrodes 16 and second openings 30 for forming the external common electrodes 19 .
[0105] A part partitioning the first opening 29 and the second opening 30 serves as the above described band section 7 . Both side portions of the first opening 29 serve as the above described side end portions 27 .
[0106] The second opening 30 is formed with widened portions 42 extended toward the first opening 29 at both ends of the second opening 30 in order to form the widened portions 2 .
[0107] In a state that the mask 28 is placed on the top faces of the piezoelectric element formation members 23 , the conductive material is deposited thereon, so that the external segment electrodes 16 and the external common electrodes 19 are formed at portions where is not covered with the mask 28 .
[0108] After the non-active region of each piezoelectric element formation member 23 is fixed on the fixation board 15 , the slits 25 are formed by the wire saw or the like to form the pectinated piezoelectric elements 14 as shown in FIGS. 1A and 1B.
[0109] In such a configuration, the vapor deposition can be executed with high accuracy even when the plural piezoelectric element formation members 23 are subjected to the vapor deposition.
[0110] In the above embodiment, the ink jet recording head is exemplified as the liquid ejection head. As another examples of the liquid ejection head, there may be exemplified a recording head installed in an image forming apparatus such as a printer, a coloring material ejection head used for manufacturing a color filter installed in a liquid crystal display or the like, an electrode material ejection head used for forming electrodes installed in an organic EL display, a field emission display or the like, and an organic compound ejection head used for manufacturing a biochip.
[0111] Although the present invention has been shown and described with reference to specific preferred embodiments, various changes and modifications will be apparent to those skilled in the art from the teachings herein. Such changes and modifications as are obvious are deemed to come within the spirit, scope and contemplation of the invention as defined in the appended claims. | First internal electrode layers and second internal electrode layers are alternately laminated in a substrate while sandwiching piezoelectric material layer therebetween. The first internal electrode layers are exposed to a first end face of the substrate, and the second internal electrode layers are exposed to a second end face of the substrate which is opposite to the first end face. A first external electrode layer is formed on the first end face and a third end face connecting the first end face and the second end face. A second external electrode layer is formed on the second end face and the third end face. The second external electrode layer is electrically independent from the first external electrode layer. The first external electrode layer and the first internal electrode layers are to be divided by slits extending from the first end face to form a plurality of piezoelectric elements arrayed in a first direction. The second external electrode layer includes a pair of first sections provided on both end portions of the third end face in the first direction, and having a first dimension in a second direction perpendicular to the first direction, and a second section provided between the first sections, and having a second dimension in the second direction which is less than the first dimension. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of prior U.S. Provisional Application No. 61/003,647, filed Nov. 19, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates generally to self-standing riser assemblies utilized during oil and gas exploration and production operations, and in a particular though non-limiting embodiment, to a self-standing riser system equipped with multiple buoyancy chambers suitable for deployment in a variety of water depths and sea conditions.
BACKGROUND OF THE INVENTION
[0003] Self-standing risers (hereinafter “SSR”) are employed in the oil and gas industry to suspend production and injection lines from subsea production units, and to support holding tendons associated with floating offshore structures. Known SSR can be used to facilitate standard “shallow-water” (e.g., between 0 feet and around 600 feet of water) drilling units and cost effective production facilities by placing blow-out preventers and production trees on top of a buoyancy chamber.
[0004] The conventional approach to the SSR design has been to employ one large buoyancy chamber that supports the riser or tendon loads. However, this approach has led to increased costs associated with the construction and installation of the buoyancy chambers. Such factors have resulted in a lack of significant SSR system development by operators who could realize a broad spectrum of associated benefits. Nonetheless, the industry as a whole desires a reduction in oil and gas production costs, a decrease in time delays for drilling exploration wells, and increased development of previously discovered fields. There is, therefore, a long-felt but unmet need for smaller, more flexible riser systems capable of more rapid manufacture and deployment that assist in the profitable development of previously under produced oil and gas fields.
SUMMARY OF THE INVENTION
[0005] A self-standing riser system suitable for deepwater oil and gas exploration and production is provided, the system including a lower riser assembly disposed in communication with a primary well-drilling fixture; one or more intermediate buoyancy chambers disposed in communication with the lower riser assembly and one or more portions of intermediate riser assembly, wherein one or more of the buoyancy chambers further includes an open-bottomed lower surface portion; and an upper riser assembly disposed in communication with one or more upper buoyancy chambers, wherein one or more of the upper buoyancy chambers further includes a fully enclosed portion.
[0006] Ballast loads for the chambers; stress joints for the riser assemblies; methods and means of system deployment and maintenance; access to blow-out preventers, wellheads and production trees; and various system interconnections are also provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The embodiments disclosed herein will be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
[0008] FIG. 1A is a schematic diagram of a self-standing riser system equipped with an open-bottom buoyancy chamber in calm waters, according to an example embodiment known in the prior art.
[0009] FIG. 1B is a schematic diagram of a self-standing riser system equipped with an open-bottomed buoyancy chamber that is nearing its spill point.
[0010] FIG. 1C is a schematic diagram of a self-standing riser equipped with an open-bottomed buoyancy chamber that has tilted beyond its spill point.
[0011] FIG. 2 is a schematic diagram depicting the effects of pressure, temperature and depth on a closed-bottom buoyancy chamber.
[0012] FIG. 3 is a schematic diagram of a self-standing riser system comprising multiple buoyancy chambers, according to example embodiments of the present invention.
[0013] FIG. 4 is a schematic diagram depicting the installation of a self-standing riser system comprising multiple buoyancy chambers, according to example embodiments of the invention.
DETAILED DESCRIPTION
[0014] There are presently two known types of submersible buoyancy chambers suitable for oil and gas exploration and production: a closed container design, and an open-bottomed design. Both types of chambers, if pressurized and secured by a riser, will exert an upward lifting force on the riser. Certain embodiments also comprise features lending adjustability to the system, as may be known to those of skill in the art.
[0015] The closed container design is similar in some respects to a submarine, in that there are typically one or more ballast chambers used to house a fluid, such as a light gas, seawater, etc. Once a desired ratio of fluids is achieved, the chamber is closed off by valves or other means known in the art.
[0016] An open-bottomed buoyancy chamber includes many design functions similar to those of the closed container design. However, once desired buoyancy characteristics are achieved, fluid disposed within the chamber is simply trapped by the sides and top thereof.
[0017] FIG. 1A illustrates a known, open-bottomed, buoyancy chamber disposed in communication with an SSR and filled with a fluid, for example, a pressurized gas. As seen, a combination of calm water currents, minimal external forces, and a sufficient amount of buoyancy applied to the SSR results in minimal lateral displacement force. Accordingly, the buoyancy chamber illustrated in FIG. 1A experiences little or no tilt relative to its vertical axis, and fluid contained within the chamber remains enclosed.
[0018] If, however, a sufficiently large enough force is applied to the chamber, such as a strong current as depicted in FIG. 1B , the SSR will begin to tilt away from its vertical axis. FIG. 1B also illustrates how the fluid contained within the chamber has shifted relative to the system's tilt away from its vertical axis. However, the chamber can accommodate a tilt of up to a certain critical angle (which depends largely on its design dimensions) before the critical spill point angle is reached, and fluid begins to escape from the chamber.
[0019] FIG. 1C further illustrates how the spill rate of the gas contained within an open-bottomed buoyancy chamber will increase as the critical tilt angle is reached and exceeded. In particular, spillage will result in even greater loss of buoyancy, and therefore a proportionately increasing tilt angle, which will cause more and more gas to escape from the chamber. Eventually, enough gas escapes that the buoyant force is reduced to the point where the chamber can no longer support the riser, thereby causing the system to fail.
[0020] Despite such drawbacks, open-bottomed chambers can operate at extreme water depths with a reduced concern of structural collapse than a closed system, since the open design allows fluid pressures within the chamber to equalize with surrounding pressures at even great depths. Furthermore, the open-bottomed design has less overall system weight due to a reduction in required construction materials, since there is no bottom, and the remainder of the shell will require less thickness and reinforcement in order to withstand deepwater fluid pressures.
[0021] In contrast, closed container buoyancy chambers do not suffer as greatly from the problem of tilting caused by currents and surface effects, and are typically the appropriate design choice in areas where currents and surface effects are significant enough to cause major lateral displacement from the vertical axis. However, if either of the described buoyancy chambers sustain a leak (for example, a leak caused by container breach, valve malfunction, etc.), the gas or other fluid will escape and the SSR can fail, as illustrated in FIG. 1C .
[0022] Closed container buoyancy chambers must also be robust enough to offset external forces such as deepwater fluid pressure. As illustrated in FIG. 2 , such chambers must, as a threshold matter, have sufficient structural integrity and wall thickness to resist expected pressures that might cause a collapse of the chamber's outer shell. Moreover, when deploying a closed buoyancy chamber filled with a gas, the internal gas pressures and temperatures should be sufficiently proportional to the external water pressures and temperatures that an associated pressure or temperature gradient will not induce an effective change in gas volume within the chamber which could cause the chamber's outer shell to crack or collapse.
[0023] Typically, SSR systems are constrained to include the use of only a single buoyancy chamber due to the chamber's large size. However, the larger buoyancy chamber designs increase the time and cost associated with building and deploying the operating system. Moreover, deployment of large, pressurized chamber at great depths (e.g., >500 ft. or so) can prove to be an exceedingly difficult task. Furthermore, as the diameter of the buoyancy chamber is increased, the probability of structural failure and warping caused by handling during construction and deployment is also increased.
[0024] The detailed description that follows includes exemplary systems, methods, and techniques that embody techniques of the presently inventive subject matter. However, it will be understood by those of skill in the art that the described embodiments may be practiced without one or more of the specific details disclosed herein. In other instances, well-known manufacturing equipment, protocols, structures and techniques have not been shown in detail in order to avoid obfuscation in the description.
[0025] Referring now to the example embodiment depicted in FIG. 3 , an SSR system 14 is depicted comprising a plurality of subordinate buoyancy chambers configured to admit to installation in deeper water depths than any previously known SSR systems. According to an alternative embodiment, SSR 14 can be stacked with multiple buoyancy chambers as illustrated in FIGS. 4A , 4 B, 4 C and 4 D. Although illustrated in FIG. 3 as a combination of lower SSR assembly 10 and upper SSR assembly 12 , embodiments of the overall SSR system 14 can comprise any number of individual SSR assemblies.
[0026] In the embodiment depicted in FIG. 3 , lower SSR assembly 10 is first deployed. In one example, a specially designed vessel equipped specifically to deploy buoyancy chambers and SSR assemblies is used. Following deployment, lower SSR assembly 10 is joined in mechanical communication with a casing wellhead established near the mud-line. In a typical embodiment, the casing wellhead has been preset into a well hole bored into an associated seafloor surface.
[0027] In further embodiments, one or more intermediate buoyancy chambers 16 is attached to lower SSR assembly 10 , thereby providing increased stability in deep or turbulent waters. Depending on operating conditions, intermediate buoyancy chamber 16 can comprise a closed-container design, but in most instances will comprise the open-bottomed design for the reasons described above, with the only firm requirement being that intermediate chamber 16 must in any event be capable of providing the support required to control lower SSR assembly 10 and upper SSR assembly 14 .
[0028] In further example embodiments, intermediate buoyancy chamber 16 is disposed in mechanical communication with either previously known or custom-designed drilling, production and exploration equipment. Thus, for example, the top and bottom portions of an intermediate buoyancy chamber may comprise one or more of a blowout preventer, a production tree, or a wellhead that functions in a manner similar to the casing wellhead placed near mud-line of the ocean floor. Attachment of the drilling, production and exploration equipment can be achieved using either known or custom connection and fastening members, e.g., hydraulic couplers, various nut and bolt assemblies, welded joints, pressure fittings (either with or without gaskets), swaging, etc., without departing from the scope of the invention.
[0029] In further embodiments, an upper SSR assembly 12 is deployed and disposed in mechanical communication with a wellhead, blowout preventer, or production tree (or another, custom-designed device combining elements of one or more of such devices) installed atop an upper surface of the intermediate chamber 16 or a connecting member associated therewith. According to other example embodiments, the installation process continues until the desired number of such assemblies are installed in serial communication with one another in order to achieve a stable and efficient SSR system 14 , as depicted in FIGS. 4A-4D .
[0030] In order to further stabilize the SSR system 14 , example embodiments can utilize stress joints 22 , as depicted in FIG. 3 . Stress joints 22 can comprise any known material, for example, a plastic, rubber, or metal material, but should in any event be capable of maintaining the SSR 14 system's structural integrity and overall stability.
[0031] Consistent with the example SSR system 14 illustrated in FIG. 3 , a plurality of upper buoyancy chambers 18 , 20 includes an open-bottomed chamber 18 and a closed-container type chamber 20 . In a one example embodiment, at least one of said upper chambers—generally the topmost—will comprise a closed design, while others in the system, including intermediate chamber 16 , will comprise an open-bottomed design. In another example embodiment, all of the chambers in the system are either open or closed, and in still further embodiments, combinations of open and closed chambers are employed across the system.
[0032] In some embodiments, the multiple open-bottomed design buoyancy chambers are utilized to facilitate deployment in deeper waters in which surrounding fluid pressures are greatest. Other embodiments utilize a plurality of closed-container type chambers disposed near the top of the SSR system 14 , thereby improving the system's overall stability and balance. Such configurations can also help avoid the system's tendency to tilt away from its vertical axis as a result of external lateral forces, such as a forceful cross-current.
[0033] In still further embodiments, a plurality of buoyancy chambers disposed in mechanical communication with upper SSR assembly 12 allows for the overall SSR system 14 to maintain required functionality and stability in varying water depths and conditions, thereby improving its efficiency and operability.
[0034] Further example embodiments comprise a plurality of upper buoyancy chambers disposed in mechanical communication with commonly known drilling, production and exploration equipment. Thus, for example, the top and bottom portions of an upper buoyancy chamber may comprise one or more of a blowout preventer, a production tree, or a wellhead designed to function in a manner similar to the casing wellhead placed near mud-line of the ocean floor.
[0035] In further embodiments, the buoyancy chambers utilized throughout the system further comprise auxiliary buoyancy materials, such as syntactic foam or air filled glass micro-spheres that lend buoyancy to the system. Injecting one or more of these materials within an open-bottomed chamber will assist in prevention of buoyancy fluid (e.g., gas, liquid, etc.) loss should tilting occur, or if there is a breach or failure of tubing, valves, or other equipment utilized in connection with the buoyancy chamber.
[0036] In the example embodiment illustrated in FIG. 4A , a deployment vessel deploys a lower SSR assembly 40 to the ocean floor where it is mechanically disposed in communication with a casing wellhead near the mud-line. FIG. 4A further depicts an intermediate buoyancy chamber 41 installed atop the SSR assembly 40 . Various embodiments of the intermediate buoyancy chamber 41 further comprise one or more previously known or custom-fit attachment mechanisms, such as a combined blowout preventer and production tree, so that the intermediate chamber 41 is useful during operations for purposes other than mere connection with an upper SSR assembly 42 . In various other embodiments, a plurality of intermediate buoyancy chambers 41 are deployed and mechanically disposed in communication with a previously installed SSR assembly or another intermediate buoyancy chamber (see, for example, FIGS. 4B-4D ).
[0037] In FIG. 4C , intermediate SSR assemblies 42 and 44 are deployed and disposed in mechanical communication with a well-head affixed atop intermediate buoyancy chamber 41 . In some example embodiments, additional intermediate buoyancy chambers 41 , 43 , 45 serve as additional support and connection components for the intermediate SSR assemblies. Such redundant embodiments can achieve heretofore unknown SSR system depths of more than 15,000 ft. with the addition of multiple intermediate SSR assemblies.
[0038] In the example embodiment depicted in FIG. 4D , a final SSR assembly 46 is deployed to complete the SSR system 50 . FIG. 4D further depicts an embodiment employing a plurality of buoyancy chambers 47 atop SSR assembly 46 in order to complete the overall SSR system 50 . As previously discussed, embodiments of the plurality of buoyancy chambers 47 can comprise a mixture of open-bottomed and closed-container designs, or any other configuration made desirable by operating conditions, including of course the installation of only a single such chamber.
[0039] The foregoing specification is provided for illustrative purposes only, and is not intended to describe all possible aspects of the present invention. Moreover, while the invention has been shown and described in detail with respect to several exemplary embodiments, those of ordinary skill in the art will appreciate that minor changes to the description, and various other modifications, omissions and additions may also be made without departing from the spirit or scope thereof. | A multi-tiered self-standing riser system includes one or more intermediate buoyancy chambers configured to provide an upward lifting force on strings of associated riser assemblies. The intermediate chambers have either an open-bottomed or closed container design. The chambers can further include an auxiliary buoyant material designed to either mix with or contain pressurized fluids injected into the chambers. The self-standing riser system further includes a lower riser assembly affixed to a primary well-drilling fixture. The system also includes an upper riser assembly and one or more additional buoyancy chambers disposed in either direct or indirect communication with one another, as well as with drilling, production and exploration equipment as required by associated operations. | 4 |
This application is a continuation-in-part of U.S. patent application Ser. No. 14/706,659 filed May 7, 2015, which claims priority to U.S. Patent Appln. No. 61/991,118 filed May 9, 2014.
BACKGROUND OF THE INVENTION
1. Technical Field
The present disclosure relates to components for a gas turbine engine and, more particularly, to the additive manufacture thereof.
2. Background Information
Gas turbine engines typically include a compressor section to pressurize airflow, a combustor section to burn a hydrocarbon fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases.
In the gas turbine industry, methods for fabricating components with internal passageways, such as blades and vanes within the turbine section, using additive manufacturing invite much attention. Since a component is produced in a continuous process in an additive manufacturing operation, features associated with conventional manufacturing processes such as machining, forging, welding, casting, etc. can be eliminated leading to savings in cost, material, and time.
An inherent feature of metallic components fabricated by additive manufacturing is that the metallic material forming the component has a polycrystalline microstructure. However, for numerous types of turbine components it is preferable to use a metallic material having a single crystal, or a columnar grain microstructure, which microstructure is able to withstand the higher temperatures and stresses typically experienced in the operating environment in a hot gas stream.
SUMMARY
A method of manufacturing a component according to one disclosed non-limiting embodiment of the present disclosure includes additively manufacturing a crucible for forming the component; solidifying a metal material within the crucible to form a metal directionally solidified microstructure within the component; and removing a sacrificial core to reveal the component.
In a further embodiment of the present disclosure, the step of solidifying the metal material includes directionally solidifying the material to have a single crystal microstructure.
In a further embodiment of the present disclosure, the step of solidifying the metal material includes directionally solidifying the material to have a columnar grain microstructure.
In a further embodiment of the present disclosure, the metal material is selected from the group consisting of a nickel based superalloy, cobalt based superalloy, iron based superalloy, and mixtures thereof.
In a further embodiment of the present disclosure, the crucible is additively manufactured of at least one of a ceramic material, a refractory metal alloy, or combinations thereof.
In a further embodiment of the present disclosure, the metal material is a powder.
In a further embodiment of the present disclosure, the crucible includes a core at least partially within a shell, the core at least partially defines at least one internal passageway within the component.
A further embodiment of the present disclosure includes forming the core via additive manufacturing.
A further embodiment of the present disclosure includes forming the shell via additive manufacturing.
In a further embodiment of the present disclosure, the core at least partially defines the internal passageways within the component.
A method of manufacturing a component according to another disclosed non-limiting embodiment of the present disclosure includes additively manufacturing the component of a metal material; additively manufacturing a core at least partially within the component; at least partially encasing the additively manufactured component and additively manufactured core within a shell; melting the additively manufactured component; solidifying the metal material of the additively manufactured component to form a metal directionally solidified microstructure; and removing the shell and the additively manufactured core from the directionally solidified component.
In a further embodiment of the present disclosure, the step of solidifying the metal material includes directionally solidifying the material to have a single crystal microstructure.
In a further embodiment of the present disclosure, the step of solidifying the metal material includes directionally solidifying the material to have a columnar grain microstructure.
In a further embodiment of the present disclosure, the metal material is a powder.
In a further embodiment of the present disclosure, the core at least partially defines at least one internal passageway within the component.
A further embodiment of the present disclosure includes concurrently additively manufacturing the component of a metal material and the core within the component.
In a further embodiment of the present disclosure, the core at least partially defines microchannels within the component.
In a further embodiment of the present disclosure, the microchannels are additively manufactured of a refractory material and the internal passageways are manufactured of a ceramic material.
In a further embodiment of the present disclosure, the additive manufacturing is performed by a multi-powder bed system.
A further embodiment of the present disclosure includes applying a wax material at least partially onto the component.
A further embodiment of the present disclosure includes melting the wax material prior to melting the additively manufactured component.
A further embodiment of the present disclosure includes applying the wax material to an airfoil portion of the component.
A component for a gas turbine engine, according to another disclosed non-limiting embodiment of the present disclosure includes a metal directionally solidified material component, the metal directionally solidified material component having been additively manufactured of a metal material concurrently with a core, the metal material having been remelted and directionally solidified.
In a further embodiment of the present disclosure, the component has a directionally solidified single crystal microstructure.
In a further embodiment of the present disclosure, the component has a directionally solidified columnar grain microstructure.
In a further embodiment of the present disclosure, the metal single crystal material component includes an airfoil.
In a further embodiment of the present disclosure, the metal single crystal material component is a rotor blade.
The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, the following description and drawings are intended to be exemplary in nature and non-limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows.
FIG. 1 is a schematic cross-section of an example of gas turbine engine architecture.
FIG. 2 is a schematic cross-section of another example of gas turbine engine architecture.
FIG. 3 is an enlarged schematic cross-section of an engine turbine section.
FIG. 4 is a perspective view of a turbine blade as an example component with internal passages.
FIG. 5 is a schematic cross-section view of the showing the internal passages.
FIG. 6 illustrates a crucible in accordance with aspects of this disclosure.
FIG. 7 is a schematic lateral cross-section view of the example component with internal passages within the crucible.
FIG. 8 is a flow chart of one disclosed non-limiting embodiment of a method for fabricating an example component with internal passages.
FIG. 9 is a flow chart of another disclosed non-limiting embodiment of a method for fabricating an example component with internal passages.
FIG. 10 is a lateral cross-section view of an example component with internal passages within a crucible as manufactured by the method of FIG. 9 .
FIG. 11 is a flow chart of another disclosed non-limiting embodiment of a method for fabricating an example component with internal passages.
FIG. 12 is a lateral cross-section view of an example component with internal passages within a crucible as manufactured by the method of FIG. 11 .
FIG. 13 is a flow chart of another disclosed non-limiting embodiment of a method for fabricating an example component with internal passages.
FIG. 14 is a lateral cross-section view of an example component with internal passages within a crucible as manufactured by the method of FIG. 13 .
FIG. 15 is a flow chart of another disclosed non-limiting embodiment of a method for fabricating an example component with internal passages.
FIG. 16 is a lateral cross-section view of an example component with internal passages within a crucible and coated with a wax layer as manufactured by the method of FIG. 15 .
DETAILED DESCRIPTION
FIG. 1 schematically illustrates a gas turbine engine 20 . The gas turbine engine 20 is disclosed herein as a two-spool turbo fan that generally incorporates a fan section 22 , a compressor section 24 , a combustor section 26 and a turbine section 28 . Alternative engine architectures 200 might include an augmentor section 12 , an exhaust duct section 14 and a nozzle section 16 ( FIG. 2 ) among other systems or features. The fan section 22 drives air along both a bypass flowpath and into the compressor section 24 . The compressor section 24 drives air along a core flowpath for compression and communication into the combustor section 26 then expansion through the turbine section 28 . Although depicted as a turbofan in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engine architectures such as turbojets, turboshafts, and three-spool (plus fan) turbofans.
The engine 20 generally includes a low spool 30 and a high spool 32 mounted for rotation about an engine central longitudinal axis X relative to an engine static structure 36 via several bearing structures 38 . The low spool 30 generally includes an inner shaft 40 that interconnects a fan 42 , a low pressure compressor (“LPC”) 44 and a low pressure turbine (“LPT”) 46 . The inner shaft 40 drives the fan 42 directly or through a geared architecture 48 to drive the fan 42 at a lower speed than the low spool 30 . An exemplary reduction transmission is an epicyclic transmission, namely a planetary or star gear system.
The high spool 32 includes an outer shaft 50 that interconnects a high pressure compressor (“HPC”) 52 and high pressure turbine (“HPT”) 54 . A combustor 56 is arranged between the high pressure compressor 52 and the high pressure turbine 54 . The inner shaft 40 and the outer shaft 50 are concentric and rotate about the engine central longitudinal axis “A” which is collinear with their longitudinal axes.
Core airflow is compressed by the LPC 44 then the HPC 52 , mixed with the fuel and burned in the combustor 56 , then expanded over the HPT 54 and the LPT 46 . The turbines 54 , 46 rotationally drive the respective low spool 30 and high spool 32 in response to the expansion. The main engine shafts 40 , 50 are supported at a plurality of points by bearing structures 38 within the static structure 36 . Bearing structures 38 at various locations may alternatively or additionally be provided.
With reference to FIG. 3 , an enlarged schematic view of a portion of the turbine section 28 is shown by way of example; however, other engine sections will also benefit here from. A full ring shroud assembly 60 within the engine case structure 36 supports a blade outer air seal (BOAS) assembly 62 with a multiple of BOAS segments 64 proximate to a rotor assembly 66 (one schematically shown).
The full ring shroud assembly 60 and the blade outer air seal (BOAS) assembly 62 are axially disposed between a forward stationary vane ring 68 and an aft stationary vane ring 70 . Each vane ring 68 , 70 includes an array of vanes 72 , 74 that extend between a respective inner vane support 76 , 78 and an outer vane support 80 , 82 . The outer vane supports 80 , 82 are attached to the engine case structure 36 .
The rotor assembly 66 includes an array of blades 84 circumferentially disposed around a disk 86 . Each blade 84 includes a root 88 , a platform 90 and an airfoil 92 (also shown in FIG. 4 ). A portion of each blade root 88 is received within a rim 94 of the disk 86 . Each airfoil 92 extends radially outward, and has a tip 96 disposed in close proximity to a blade outer air seal (BOAS) assembly 62 . Each BOAS segment 64 may include an abradable material to accommodate potential interaction with the rotating blade tips 96 .
To resist the high temperature stress environment in the hot gas path of a turbine engine, each blade 84 may be formed to have a single crystal or columnar grain microstructure. It should be appreciated that although a blade 84 with internal passageways 98 ( FIG. 5 ) will be described and illustrated in detail, other components including, but not limited to, vanes, fuel nozzles, airflow swirlers, combustor liners, turbine shrouds, vane endwalls, airfoil edges and other gas turbine engine components “W” may also be manufactured in accordance with the teachings herein.
The present disclosure involves the use of additive manufacturing techniques to form a component “W”, as will be disclosed in the embodiments described below. In general terms, additive manufacturing techniques allow for the creation of a component “W” by building the component with successively added layers; e.g., layers of powdered material. The additive manufacturing process facilitates manufacture of relatively complex components, minimize assembly details and minimize multi-component construction. In the additive manufacturing process, one or more materials are deposited on a surface in a layer. In some instances, the layers are subsequently compacted. The material(s) of the layer may be subsequently unified using any one of a number of known processes (e.g., laser, electron beam, etc.). Typically, the deposition of the material (i.e. the geometry of the deposition later for each of the materials) is computer controlled using a three-dimensional computer aided design (CAD) model. The three-dimensional (3D) model is converted into a plurality of slices, with each slice defining a cross section of the component for a predetermined height (i.e. layer) of the 3D model. The additively manufactured component is then “grown” layer by layer; e.g., a layer of powdered material(s) is deposited and then unified, and then the process is repeated for the next layer. Examples of additive manufacturing processes that can be used with the present disclosure include, but are not limited to, Stereolithography (SLS), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), Laser Net Shape Manufacturing (LNSM), Direct Metal Deposition (DMD), Direct Metal Laser Sintering (DMLS) and others. The present disclosure is not limited to using any particular type of additive manufacturing process.
In the embodiments described below, an additive manufacturing process is utilized to form a crucible 100 ( FIG. 6 ) and a component “W” 84 (e.g., a blade, a vane, etc.). With reference to FIG. 6 , the additive manufactured crucible 100 generally includes a core 102 and a shell 104 . The shell 104 and the core 102 define the geometry of the component “W” (e.g., including complex exterior and interior geometries of the component “W”), and provide a support structure for the component “W”. The shell 104 forms a structure having surfaces that will define the outer surfaces of the component “W”. The core 102 forms bodies that occupy volumes that will be voids (e.g., internal passages) within the final component “W”. The crucible 100 may comprise a variety of different material types; e.g., refractory metals, ceramics, combinations thereof, etc. As will be explained below, the crucible 100 may be utilized as a melting unit and/or a die during processing of the component “W”.
With reference to FIG. 8 , according to one disclosed non-limiting embodiment for forming single crystal or columnar grain superalloy component with internal passageways, a method includes forming a crucible 100 . The crucible 100 is additively manufactured (Step 202 ). It should be appreciated that the core 102 and/or shell 104 of the crucible 100 may be additively manufactured from materials that include, but are not limited to, ceramic material such as silica, alumina, zircon, cobalt, mullite, kaolin, refractory metals, combinations thereof, etc.
Following additive manufacture, the crucible 100 may be dried and fired (i.e. bisqued) at an intermediate temperature before high firing to fully sinter and densification. The additively manufactured crucible 100 thereby forms a cavity for forming the component W. That is, the crucible 100 is integrally formed by the additive manufacturing process such that the conventional separate manufacture of the core and shell are essentially combined into a single step. It should be appreciated that single or multiple molds and cavities may be additively manufactured and assembled.
The crucible 100 may then be filled with a component material such as a desired metal (Step 204 ). Non-limiting examples of metal component materials include superalloys; e.g., nickel based superalloys, cobalt based superalloys, iron based superalloys, combinations thereof, etc. In some instances, the component material added to the crucible 100 may be in powder form that can be subsequently melted. In other instances, the component material added to the crucible 100 may be in molten form that is subsequently solidified. The present disclosure is not limited, however, to adding component material in any particular form.
In some instances, the crucible is combined or utilized with structure (e.g., a starter seed and a chill plate) operable to cause the component W to be formed having a directionally solidified microstructure (i.e., a “DS” microstructure), such as a single crystal microstructure or a columnar grain microstructure. A single crystal solid (sometimes referred to as a “monocrystalline solid”) component is one in which the crystal lattice of the substantially all of the component material is continuous and unbroken to the edges of the component, with virtually no grain boundaries. Processes for growing a single crystal alloy structure are believed to be known to those of ordinary skill in the art, and therefore descriptions of such processes are not necessary here for enablement purposes. However, an example is provided hereinafter to facilitate understanding of the present disclosure. A portion of a metallic starter seed may extend into a vertically lower portion of the component material receiving portion of the crucible 100 . During subsequent processing of the component “W”, molten component material contacts the starter seed and causes the partial melt back thereof. The component material is subsequently solidified by a thermal gradient moving vertically through the crucible 100 ; e.g., the component is solidified epitaxially from the unmelted portion of the starter seed to form the single crystal component. The thermal gradient used to solidify the component may be produced by a combination of mold heating and mold cooling; e.g., using a mold heater, a mold cooling cone, a chill plate and withdrawal of the component being formed. As indicated above, the aforesaid description is an example of how a single crystal microstructure component may be formed, and the present disclosure is not limited thereto.
Now referring again to the embodiment described in FIG. 8 , a single crystal starter seed or grain selector may be utilized to enable the component “W” to possess a single crystal microstructure (or other DS microstructure) during solidification (Step 206 ). The solidification may utilize a chill block in a directional solidification furnace. The directional solidification furnace has a hot zone that may be induction heated and a cold zone separated by an isolation valve. The chill block and additively manufactured crucible 100 may be elevated into the hot zone and filled with molten super alloy. After the pour, or being molten, the chill plate may descend into the cold zone causing a solid/liquid interface to advance from the partially molten starter seed, creating the desired single crystal microstructure (or other DS microstructure type) as the solid/liquid interface advances away from the starter seed. The formation process may be performed within an inert atmosphere or vacuum to preserve the purity of the component material being formed.
Following solidification, the additively manufactured crucible 100 may be removed from the solidified component “W” by various techniques (e.g., caustic leaching), thereby leaving behind the finished single crystal component (Step 208 ). After removal, the component W may be further finished such as by machining, threading, surface treating, coating or any other desirable finishing operation (Step 210 ).
Now referring to FIGS. 9 and 10 , in another non-limiting embodiment a method 300 includes additively manufacturing a component “W” (e.g. a turbine blade, vane, etc.) having internal cooling passages (Step 302 ) and a crucible 100 . In this embodiment, the component “W” and the crucible 100 are additively manufactured using a multi-feedstock process such as a two-powder bed system. A structure 130 of the component W is manufactured of the desired superalloy, while the core 102 and shell 104 of the crucible 100 are manufactured of a different material such as a ceramic, a refractory metal, or other material which is later removed ( FIG. 10 ). With respect to the internal cooling passages of the component “W”, during the additive manufacturing process, a ceramic material, a refractory metal material, or other core 102 material is formed at the locations within the layers of the additively formed structure to coincide with the locations of the voids that will form the passages within the component. The core 102 within the component structure 130 and the shell 104 that surrounds the component structure 130 are later removed; e.g., in a manner as described above.
The structure 130 of the component W, being additively manufactured, may be a polycrystalline superalloy. As indicated above, it may be desirable for the component structure 130 to have a single crystal microstructure (or other DS microstructure) that is better suited to withstand the high temperature, high stress operating environment of the gas turbine engine.
To thereby facilitate formation of a component having a single crystal microstructure (or other DS microstructure), the additively manufactured superalloy structure 130 is re-melted within the crucible 100 (Step 304 ). For example, the additively manufactured superalloy structure 130 may be re-melted and directionally solidified (e.g., as described above) to form a metal single crystal structure (or other DS microstructure) within the crucible 100 . As indicated above, the present disclosure is not limited to any particular technique for creating the single crystal microstructure.
Following solidification, the additively manufactured crucible 100 may be removed from the solidified component W such as by caustic leaching, to leave the finished single crystal component (Step 306 ). After removal, the component W may be further finished such as by machining, threading, surface treating, coating or any other desirable finishing operation (Step 308 ).
Now referring to FIGS. 11 and 12 , a method 400 according to another non-limiting embodiment includes additively manufacturing component “W” with a multi-feedstock additive manufacturing process such as three-powder bed system (Step 402 ). The component “W” 140 is manufactured of the desired superalloy while the core 102 and shell 104 of the crucible 100 are manufactured of a different material ( FIG. 12 ). Locations for the internal cooling passages 142 of the component “W” are additively manufactured of ceramic material and locations for microcircuits 144 of the component “W” are additively manufactured of a refractory metal material. The microcircuit 144 is relatively smaller than, and may be located outboard of, the internal cooling passages 142 to facilitate tailorable, high efficiency convective cooling. The bodies formed to create the microcircuits may be formed of refractory metals (e.g., molybdenum (Mo), Tungsten (W), etc.) that possess relatively high ductility for formation into complex shapes and have melting points that are in excess of typical casting temperatures of nickel based superalloys. Refractory metals of this type can be removed by various know techniques (e.g., chemical removal, thermal leeching, oxidation methods, etc.) to leave behind a cavity forming the microcircuit 144 .
As described above, to facilitate formation of a component having a single crystal microstructure (or other DS microstructure), the additively manufactured component 140 is re-melted within the crucible 100 (Step 404 ) formed in step 402 , and subjected to processes for creating the single crystal microstructure (or other DS microstructure type) within the component 140 . As indicated above, the present disclosure is not limited to any particular technique for creating the single crystal microstructure.
Following solidification, the additively manufactured crucible 100 may be removed from the solidified component W such as by caustic leaching, to leave the finished single crystal component “W” 140 (Step 406 ). After removal, the component “W” may be further finished such as by machining, threading, surface treating, coating or any other desirable finishing operation (Step 408 ).
Now referring to FIGS. 13 and 14 , a method 500 according to another disclosed non-limiting embodiment includes additively manufacturing component “W” with a multi-feedstock additive manufacturing process such as two-powder bed system (Step 502 ). The component “W” 150 is manufactured of the desired superalloy while microcircuits 152 of the component “W” are additively manufactured of a refractory metal material. That is, the refractory metal material is additively manufactured within the structure 150 where the microcircuits 152 will be located.
In this embodiment, the internal cooling passages 154 of the component W may be filled with a ceramic slurry to form the core 102 (Step 504 ). The slurry may include, but is not limited to, ceramic materials commonly used as core materials including, but not limited to, silica, alumina, zircon, cobalt, mullite, and kaolin. In the next step, the ceramic core may be cured in situ by a suitable thermal process if necessary (Step 506 ).
Next, a ceramic shell may then be formed over the component 150 and internal ceramic core (Step 508 ). The ceramic shell may be formed over the component 150 and ceramic core by dipping it into ceramic powder and binder slurry to form a layer of ceramic material covering the component 150 . The slurry layer is dried and the process repeated for as many times as necessary to form a green (i.e. unfired) ceramic shell mold. The thickness of the green ceramic shell mold at this step may be from about 0.2-1.3 inches (5-32 mm) The green shell mold may then be bisque fired at an intermediate temperature to partially sinter the ceramic and burn off the binder material. The mold may then be high fired at a temperature between about 1200° F. (649° C.) to about 1800° F. (982° C.) from about 10 to about 120 minutes to sinter the ceramic to full density to form the shell mold.
As described above, to facilitate formation of a component having a single crystal microstructure (or other DS microstructure), the additively manufactured component is re-melted within the crucible 100 (Step 510 ), and subjected to processes for creating the single crystal microstructure (or other DS microstructure type) within the component 150 . As indicated above, the present disclosure is not limited to any particular technique for creating the single crystal microstructure.
Following solidification, the additively manufactured crucible 100 may be removed from the solidified component W such as by caustic leaching, to leave the finished single crystal component “W” 150 (Step 512 ). After removal, the component “W” may be further finished such as by machining, threading, surface treating, coating or any other desirable finishing operation (Step 514 ).
Now referring to FIGS. 15 and 16 , a method 600 according to another disclosed non-limiting embodiment facilitates a high quality surface finish. As described above, the component “W” is additively manufactured of a desired superalloy that itself forms the cavity pattern for the crucible. The additively manufactured component “W” is then re-melted within the crucible to facilitate formation of the single crystal microstructure. However, the crucible, being formed by the additive manufactured structure, may have a relatively poor surface finish typically not acceptable for use as a blade or vane in the gas turbine engine. That is, the airfoil surfaces of the blade and vanes in the gas turbine engine necessarily require particular contour tolerances and surface finishes that are typically not achieved by direct additive manufacture or may not be achieved in an additive manufacturing process within a reasonable cycle time.
To further improve the finish of an exterior surface of a component “W” 160 (additively manufactured according to any of the above-described embodiments), a relatively thin layer of a wax material 166 may be applied to an external, aerodynamic surface 168 (e.g. an airfoil surface) of the component 160 (Step 604 ; FIG. 16 ). The wax material provides a smoother surface finish than the relatively rough surface of an additively manufactured component 160 .
Next, a ceramic shell 104 is formed over the structure 160 (Step 606 ). The ceramic shell may be formed over the additively manufactured structure 160 by dipping or other process.
The relatively thin layer of a wax material 166 is subsequently removed (Step 608 ). The relatively thin layer of a wax material 166 may be removed by heating or other operation that but does not otherwise effect the additively manufactured structure 160 .
Then, as described above, to facilitate formation of the single crystal microstructure (or other DS microstructure), the additively manufactured superalloy structure 160 is re-melted within the shell of the crucible (Step 610 ), and subjected to processes for creating the single crystal microstructure (or other DS microstructure type) within the component 150 . As indicated above, the present disclosure is not limited to any particular technique for creating the single crystal microstructure. It should be further appreciated that the re-melting (Step 610 ) may alternatively be combined with the removal of the relatively thin layer of a wax material 166 (Step 608 ).
Following solidification, the solidified component W may be removed from the crucible by caustic leaching, to leave the finished single crystal structure 160 of the component W (Step 612 ). After removal, the component W may be further finished such as by machining, threading, surface treating, coating or any other desirable finishing operation (Step 614 ).
The method disclosed herein facilitates the relatively rapid additive manufacture of single crystal microstructure (or other DS microstructure type; e.g., columnar grain) components with complex internal passages and heretofore unavailable surface finishes to withstand the high temperature, high stress operating environment of a gas turbine engine environment. While some of the illustrative embodiments described herein related to the use of metal materials, other materials may be used. For example, in some embodiments a material that may be used may include silicon.
It should be understood that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting.
It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit here from.
Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present disclosure.
The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content. | A method of manufacturing a component includes additively manufacturing a crucible; directionally solidifying a metal material within the crucible; and removing the crucible to reveal the component. A component for a gas turbine engine includes a directionally solidified metal material component, the directionally solidified metal material component having been additively manufactured of a metal material concurrently with a core, the metal material having been remelted and directionally solidified. | 5 |
RELATED APPLICATION
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK
Not Applicable.
BACKGROUND
1. Field
The invention relates to a device for a vehicle mounted in the space between the vehicle console and a seat for catching debris or like or storing articles therein.
2. General Background
DESCRIPTION OF RELATED ART INCLUDING INFORMATION DISCLOSED UNDER 37 CFR 1.97 AND 1.98
Generally speaking, most vehicles have a console in the front or passenger section of the vehicle with a driver's seat on one side of the console and a passenger's seat on the other side of the console.
There is generally a space between the front console and each of the passenger and driver's seats. Anything that falls in this space ends up on the floor beneath the seat and is difficult to retrieve. Also, on some vehicles, there is no place to store items such as cell phones, pens, tissues, etc.
There is a need for a device that is located in the space between a console and a car seat that not only deflects items that fall into this space but easily traps and collects such items. Such a device should also provide storage for small items, work in all vehicles and be easy to remove and clean.
BRIEF SUMMARY OF THE INVENTION
It is an object of this invention to provide a device that fills the spaces between the console of a vehicle and the passenger and driver's seat on opposite sides of the console.
It is a further object of the invention to provide such a device that traps and collects items that normally would fall into the spaces between the console and the seats or provides a storage area for incidental items.
It is still another object of this invention to provide such a device which is quickly and easily installed in all vehicles, is inexpensive to manufacture and easily removable for cleaning and/or emptying.
These and other objects are preferably accomplished by providing a one-piece insert, generally V-shaped in cross-section, of a resilient material that is closed off at the ends, accommodates itself to the spaces between a vehicle console and the front seats and traps or holds items therein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a perspective view of the car seat catch all and storage device in accordance with the teachings of the invention;
FIG. 2 is an elevational side view of the device of FIG. 1 ;
FIG. 3 is an elevational side view of the side opposite that of FIG. 2 ;
FIG. 4 is a top plan view of the device of FIGS. 1 to 3 ;
FIG. 5 is an end view of the device of FIG. 1 ;
FIG. 6 is a cross-sectional view of a pair of devices, as in FIG. 1 , shown installed between the center console and the front passenger and driver's seats on each side of the console, the upper surface of the console being higher than the upper surfaces of the seats;
FIG. 7 is a cross-sectional view similar to FIG. 6 where the upper surface of the console is lower than the upper surfaces of the seats;
FIG. 8 is a plan view of a portion of the front of a vehicle showing a device in accordance with the teachings of the invention installed between the front driver's seat of a vehicle and the center console;
FIG. 9 is a top plan view of a modification of the device of FIGS. 1 to 8 ;
FIG. 10 is a cross-sectional view of the device of FIG. 1 illustrating a modification thereof; and
FIG. 11 is a cross-sectional view of the device of FIG. 1 illustrating a further modification thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 of the drawing, a car seat catch all and storage device 10 is shown having a generally Vee shaped configuration in cross-section with a first vertical elongated side wall 11 , a second elongated side wall 12 connected to side wall 11 along center line 13 , extending at an angle of about 35° to 45° to side wall 11 , and terminating in an outwardly extending, elongated generally horizontally extending lip 14 . Side wall 11 terminates along its upper elongated end in a flange 17 .
Device 10 is closed off at each end by end walls 15 , 16 (see also FIG. 4 ). As such, as seen in FIGS. 2 and 3 , wall 11 is higher than wall 12 (see also FIG. 4 ).
The V-shaped cross-section of device 10 is clearly shown in FIG. 5 .
FIG. 6 is a cross-sectional view of the front interior of a vehicle showing a center console 22 . A passenger seat 18 is disposed on one side of console 22 and a driver's seat 19 is disposed on the other side of console 22 . A space 20 is normally provided between seat 18 and console 22 and a space 21 is normally provided between seat 19 and console 22 .
As previously discussed, these spaces 20 , 21 provide areas into which pens, keys, waste material, etc. may fall into and be difficult to retrieve. Further, in many vehicles, there is no place to store one's pen, cell phone, tissues, etc.
As particularly contemplated in the invention, a pair of devices 10 are inserted into the spaces 20 , 21 between seats 18 , 19 and console 22 . In the illustration in FIG. 6 , the upper end of the console 22 is higher than the upper surfaces of seats 18 , 19 . Device 10 fills the space 20 , and being of a resilient material, spreads out with lip 14 resting on the upper surface of seat 18 . The flange 17 on wall 11 abuts against the side 23 of console 22 .
Device 10 , filling the space 21 , is reversed in orientation from device 10 filling space 20 . Thus, lip 14 rests on top of seat 19 and flange 17 abuts against the side 24 of console 22 .
The versatility of device 10 can be appreciated in the set-up of FIG. 7 . Here, the upper surface of console 25 is lower than the upper surfaces of seats 26 , 27 . Device 10 , disposed the space 28 between seat 26 and console 25 , is oriented as device 10 in FIG. 6 to the right of console 22 . That is, lip 14 ( FIG. 7 ) rests on the top of console 25 and flange 17 abuts against the side 29 of seat 26 . The device 10 , disposed in space 30 , has its lip 14 resting on the top of console 25 and flange 17 abuts against the side 31 of seat 27 .
FIG. 8 illustrates another unique feature of the invention. Here, device 10 is disposed in space 32 between the driver's seat 33 and console 34 . The device 10 , again being of a resilient material, curves to follow the contour of seat 33 . That is, lip 14 overlies seat 33 and curves along the upper surface thereof.
A modified device 35 is shown in FIG. 9 . Here, end walls 36 , 37 are curved and, as seen in FIG. 10 , the intersection of walls 11 , 12 is curved along bottom 38 . Also, as seen in FIG. 11 , instead of being curved at bottom, the intersection of walls 11 , 12 may be flat as indicated at bottom wall 39 . Like numerals in FIGS. 9-11 refer to like parts of the embodiment of FIG. 1 .
Devices 10 and 35 may be of one piece of a molded resilient plastic. The configurations of devices 10 and 35 have built in hanging mechanisms and end walls which retain items falling into devices 10 and 35 . Flange 17 provides structural support.
In summary, device 10 is preferably made of a resilient material, such as a thermoplastic rubber material, so that it conforms to the spacings 19 , 20 . Further, a device 10 may be inserted into space 20 and another device 10 may be reversed and inserted into space 21 .
As seen in FIG. 6 , the device 10 in space 20 has its vertical wall 11 abutting against the side wall 22 of console 17 with wall 12 extending at an angle therefrom with lip 14 overlying the top of seat 18 . Similarly, the device 10 disposed in space 22 has its vertical wall 11 abutting against the side wall 24 of console 17 with wall 12 extending at an angle therefrom and terminating in lip 14 overlying the top of seat 19 .
The end walls 15 , 16 retain debris or articles inside of device 10 . The device 10 can be quickly and easily lifted out, emptied, or even placed in a dishwasher for cleaning. Due to the resiliency of device 10 , it follows the contour of the car seat, such as the seat 33 in FIG. 8 , extending between seat 33 and console 34 in front of the seat belt connector. A conventional cup holder and tray compartment is shown in console 34 .
Thus, device 10 eliminates the need to dig between the seats of a car to retrieve valuables or the like. Device 10 both traps and stores articles or debris and fits all spaces or gaps between car consoles and car seats. It is of one piece and its V-shape and resilient material provides for material expansion and contraction to fit all sizes of gaps in a vehicle.
One side of the V-shaped device 10 has a flap or lip 14 to hang onto whatever is lower, the seat or console, and the other side 11 of the Vee is higher and straighter so that, when the V tilts from hanging onto the lower surface, the taller straight side 11 is tilted to the higher side (seat or console) to prevent device 10 from falling into the space between the seat and console. The configuration of walls 11 , 12 allows device 10 to fit into all irregular heights of seats and console.
It can be seen that there is described a device for not only deflecting items or objects that fall into the spaces between a vehicle console and the front passenger and driver's seat, but traps or captures objects therein. The device can be easily accommodated to these spaces in all vehicles and be easily removed for cleaning. It can be used in vehicles where the passenger and driver's seats are the same height as the console, or the console is higher or lower than the seat's height.
The device can be installed in either longitudinal direction of these spaces, front to rear, or rear to front, be easily removable for cleaning and of an elastomeric material, such as a thermoplastic rubber, to follow the contours of the seats. It can be of a one piece construction, dishwasher safe, and less expensive to manufacture than known prior art devices and molded or otherwise formed from one piece of material. Thus, being of a resilient material, the hanging mechanism is built in to accommodate spacings of differing widths. It collapses easily and in the same place each time to accommodate the differing widths. The built-in end walls serve to allow items and debris to be collected inside of the device without losing such items or debris out of the ends.
The device is designed to hang onto the lower of either the console or the seat, the 90 degree flap or lip protruding from one side of the V shaped device. This causes the device to tilt in the opposite direction, where that side of the V is taller and has a straight wall without a 90 degree flap. Thus, this side tilts against the wall of the higher of the seat or console.
The strategic placement of the folds of the device allows it to be molded in a malleable material, such as thermoplastic rubber or equivalent, that uses the unique design to allow it to adapt its shape to that of the gap between the car seats and the vehicle console, wide in some areas adjacent the seat belt and narrower toward the front of the seats. Also, most vehicle seats are not straight or linearly extending and have a side curvature adjacent the spacing between the seat and console and the unique design herein curves and still maintains the integrity of the inner collecting trough.
If desired, patches of hook and loop material may be provided for adhering the same to either the upper surface of a seat or console and the undersurface of lips 14 for securing the device 10 in position.
Although a particular embodiment of the invention is disclosed, variations thereof may occur to an artisan, and the scope of the invention should only be considered in conjunction with the scope of the appended claims. | A car seat catch all and storage device of a resilient deformable material adapted to fill the gaps between the front seats of a vehicle and the center console. The device has an interior for trapping and retaining items and debris therein and conforms to the width of the gap. The device is reversible so that it can conform and fill each gap in the vehicle. | 1 |
This is a continuation-in-part of application Ser. No. 855,932 filed Apr. 25, 1986, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to windmills, and more particularly to a novel design of a windmill which generates electricity regardless of the speed of the wind.
Historically, windmills have been used for a miltitude of purposes, but generally to do mechanical work or to provide electricity by having their mechanical output coupled to a generator. The generation of electricity from windmills is presently economically feasible at today's energy prices. Therefore, there is great interest in improving a windmill's ability to deliver electricity. 2. Description of Relevant Art
The relevant art is exemplified by: Cleland U.S. Pat. No. 204,481 entitled "WIND-ENGINE"; Smith U.S. Pat. No. 232,558 entitled "WIND WHEEL"; Wood et al. U.S. Pat. No. 324,510 entitled "WIND ENGINE"; Hardaway U.S. Pat. No. 640,901 entitled "WIND AND WATER MOTOR"; Ebert U.S. Pat. No. 1,299,151 entitled "COMBINED WINDMILL AND AIR COMPRESSING MECHANISM"; Hakkarinen U.S. Pat. No. 3,473,038 entitled "WIND DRIVEN GENERATOR"; Yengst et al. U.S. Pat. No. 3,942,909 entitled "VERTICAL AXIS FLUID DRIVEN ROTOR"; Luchuk U.S. Pat. No. 3,970,409 entitled "WIND POWER AND FLYWHEEL APPARATUS"; Baumgartner et al. U.S. Pat. No. 4,012,163 entitled "WIND DRIVEN POWER GENERATOR"; Tackett U.S. Pat. No. 4,118,637 entitled "INTEGRATED ENERGY SYSTEM"; Cymara U.S. Pat. No. 4,260,325 entitled "PANEOMONE WIND TURBINE"; Tuley U.S. Pat. No. 4,276,816 entitled "WIND PROPELLED FAN"; Retz U.S. Pat. No. 4,365,929 entitled "VERTICAL WIND TURBINE POWER GENERATING TOWER"; Piston U.S. Pat. No. 4,546,264 entitled "RELATING CELLULAR ENERGY GENERATING AND STORAGE DEVICE"; Australian Pat. No. 145,506; French Pat. No. 2,448,049; French Pat. No. 900,038; West German Pat. No. 2,612,200; Japanese Pat. No. 50-132459; and Japanese Pat. No. 57-135149.
The attempts at solving the problem of what speeds are preferred for generating electricity have generally centered upon two basic design features: designing windmills which generate electricity only at relatively low speeds of wind; and designing windmills which generate electricity only at high speeds of wind. Both of these solutions are inadequate to provide maximum electrical generating capacity as they will most certainly result in a major portion of the available wind power not being utilized. Importantly, the present art fails to utilize wind at its maximum potential because of deficiencies in design and construction.
SUMMARY OF THE INVENTION
The present invention reveals novel design features for a windmill which will allow it to make maximum use of all speeds of wind, and with wind from all directions, comprising: a central axial shaft, a first flywheel attached to the upper portion of said central axial shaft, a second flywheel attached to the lower portion of said central axial shaft, a plurality of primary turbine blades, a lower supporting frame running between said upper flywheel and said turbine blades, an upper supporting frame running between said shaft and said turbine blades, said blades being each provided with a bi-directional turbine blade and a plurality of piezoelectric benders, a top member and a base member, a plurality of stator blades movably attached between said top member and said base member, said stator blades being attached so as to provide inward and outward movement relative to said central axial shaft which is being turned when said rotor blades are caused to rotate by the force of wind exerted against them, said wind being directed thereon by said stator blades, and a plurality of wind processing blades rotatably mounted between said top member and said base member.
This windmill further comprises an upper bearing support operably disposed upon said central axis, split rings operably engaged with said central axial shaft and said upper bearing support which rests upon said rings, braking means which operably engage with said central axial shaft for controlling the rate of rotation of said shaft, a lower bearing support attached to the lower portion of said central axial shaft, and electrical generating means operably engaged with said central axial shaft.
The present invention contemplates being usable over a broad range of wind speeds. This is a result of utilizing the wind processing blades and the stator blades which direct wind into the primary turbine blades and its associated wind-directing and wind-passing members, and further a result of the fact that the windmill will always possess a high pressure side and a low pressure side which will vacuum wind through, thereby additionally using the wind as its exits the windmill. Additionally, because the windmill employs the use of flywheels which are liquid dynamic in nature, meaning that they contain liquid which at low speeds stays near the central axial shaft, but at higher speeds, drains outward as the windmill rotates faster, the windmill has the ability to be rotated by winds of either low or high speed.
It is an object of the present invention that all electrical output generated through the engagement of electrical generating means with said central axial shaft will be characterized by an alternating current output to be rectified at some later point in time, but most likely after it has been stored in batteries and when it is drawn from said batteries.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical view taken along the approximate cross-section of the invention exposing many of the operative elements thereof.
FIG. 2 is a top plan view of the invention utilizing arrows to indicate the direction of the wind.
FIG. 3 is a detailed top plan view showing a section of the primary turbine blade assembly again utilizing arrows to indicate the direction of the wind.
FIG. 4 is also a detailed top plan view showing a section of the invention utilizing arrows to indicate the wind exiting the turbine blade assembly.
FIG. 5 is a cross-sectional view of the interior of the liquid dynamic flywheel.
FIG. 6 is a side view of the dynamic flywheel with the outer layer of the flywheel body removed to expose the bleed holes provided in the horizontal fluid barriers for draining back fluid contained therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the invention, generally indicated by "1", in a preferred embodiment, exposed so as to reveal both internal and external elements thereof. While the configuration of the invention according to FIG. 1 is preferred, it is envisioned that alternative configurations of the present invention may be effectively employed without deviating from the invention as envisioned.
The exposed view of invention 1 in FIG. 1 discloses the principle elements of the invention according to the preferred embodiment. The central element of the invention, axial shaft 50, resides vertically in relation to the position of invention 1. Preferably, but not exclusively, there is provided on the shaft a plurality of flywheels. While it is envisioned that the flywheels may be conventional, according to the preferred embodiment there is provided a pair of dynamic flywheels, comprising upper dynamic flywheel 48 and lower dynamic flywheel 20.
The construction of the dynamic flywheels is best seen in FIGS. 5 and 6. Referring first to FIG. 5, there is shown a cross-sectional view of a flywheel according to the present invention. The flywheel has a plurality of concentric levels of increasing diameter, the level of the smallest diameter placed lowest in relation to axial shaft 50. According to the preferred embodiment, there is shown a flywheel body 302 having three concentric levels 350, 350', 350". Also according to the preferred embodiment there is provided a preselected amount of fluid within the flywheel body 302, generally indicated at its possible positions 360, 360', 360" on levels 350, 350', 350". Referring now to FIG. 6 the dynamic fly wheel according to this invention is illustrated with its outer layer removed so as to disclose further details of this aspect of the invention. Specifically, levels 350, 350', 350" are further provided with horizontal fluid barriers 370, 370', 370". Provided in the fluid barriers are a plurality of openings to allow the passage of fluid therethrough. While these openings may be of any effective configuration, they are here illustrated as being horizontal elongated slots 362.
Referring now back to FIG. 1, there is shown primary turbine blades 34, operatively attached to upper dynamic flywheel 48 by means of a support structure. According to the preferred embodiment, this structure is provided as lower blade support structure 47. Additional support of turbine blades 34 is provided by upper blade support structure 46, operatively provided between turbine blades 34 and shaft 50.
Axial shaft 50 is rotatably mounted in an appropriate structure having a plurality of support bearings and its further provided with a generator means for converting wind power into electrical power. According to the preferred embodiment, shaft 50 is rotatably supported by upper turbine base bearing 2 and lower turbine base bearing 4. These bearings are supported themselves by a support assembly fixed to a base member. According to the preferred embodiment, turbine support assembly 12 is fixably attached to lower support and housing structure 18. At or about the lowermost portion of vertical shaft 50 is provided generator means 14. For additional support of axial shaft 50, additional support members may be provided. For example, there is provided according to this embodiment upper structural support 40 which, while not necessarily a supporting bearing, does provide the preferred additional support.
Additionally provided on axial shaft 50 are split rings 24 which support lower turbine base bearing 4. Rotational movement of the axial shaft may at times be preferentially slowed, stopped, or entirely restricted. Accordingly, a braking means should be provided. According to the preferred embodiment, rotational movement of shaft 50 is stopped, slowed, or restricted entirely by means of disc and disc brake assembly 22, thus allowing controlled speed or complete stoppage for maintenance.
The invention according to the preferred embodiment has a top which acts as a roof, a positioning member, and a means of directing wind movement. Although this can be of any effective design, according to the preferred embodiment top 44 has downwardly-angled edges which assist in diverting effective passage of wind over the top of the invention while concurrently assisting to more effectively direct wind into the invention itself. For a similar purpose, there is preferably provided but not necessarily, downwardly-angled flanges 6 to lower structural support and housing 18.
In addition to top 44 and flanges 6, wind is effectively directed into and through invention 1 by means of a plurality of blades provided about axial shaft 50 and primary turbine blades 34. While it is envisioned that a number of means may be employed, there is provided according to the preferred embodiment at least two sets of directing blades, one set being generally characterized as outer blades and the other set inner blades. Specifically provided are stator blades 26 (inner blades) and wind processing blades 28 (outer blades). These blades function to direct wind into and through invention 1.
Wind processing blades 28 are pivotally provided between top 44 and lower support and housing structure 18 by means of wind processing blade pivotal shafts 31. By means of wind processing blade position drives 30, wind processing blades 28 may be rotated as desired to enhance both wind flow into and out from the central area of invention 1. Additionally, wind processing blades 28 may be rotated so as to entirely enclose the other blades of the invention, as is more fully described below.
Stator blades 26 function in a more complex manner. They too are provided between top 44 and lower support and housing structure 18 by means of stator blade shafts 33. Additionally, the movement of stator blades 26 are adjusted by means of stator blade position adjustment drives 32 which each independently controls the positioning of its associated stator blades 26. This control, as well as the control of the positioning of the outer wind processing blades 28 and the control of electricity to the piezoelectric benders 206, 208 and 226, is all controlled by computer. Screws assist in the radial adjustments of the stators blades 26. The electrical wiring leading to the piezoelectric benders is passed through the split rings. In addition to rotational movement, stator blades 26 are capable of radial inward and outward movement relative to shaft 50, this motion best illustrated by directions generally indicated by 118 in FIG. 2. This rotational and in-and-out movement provides a more efficient means by which wind is passed into and through the invention.
Finally, in FIG. 1, there is preferably, but not necessarily, provided wind speed and direction indicator 38 and an access to turbine base housing door 10.
Referring now to FIG. 2, there is shown a top plan view of the invention utilizing indicating arrows to show the direction of the wind. As illustrated, the wind enters from the left side, the high pressure side generally indicated by 122, and exits to the right, at the low pressure side, generally indicated by 116. A plurality of wind processing blades 28 direct the movement of the wind into the through the invention. The blades 28 may be preferentially moved as described above with respect to FIG. 1 so as to maximize utility of the movement of wind. Further enhancing this movement are stator blades 26 which are also capable of movement as described above with respect to FIG. 1 so as to provide maximum movement of the wind. Preferably, but not necessarily, two of these blades, blocking blades 120, act to block the wind at preferred places, so as to further enhance the efficient movement of wind.
Additionally provided are primary turbine blades 34 which are fixably attached to axial shaft 50 as described above with respect to FIG. 1. To enhance the wind utilization characteristics of turbine blades 34, each blade is additionally provided with turbine bi-directional blade 106.
The relationship between the primary turbine blades 34, their associated bi-directional blades 106 and other features is more clearly seen in FIGS. 3 and 4.
Referring first to FIG. 3 which indicates a high pressure side generally indicated by 122, there is shown a plurality of primary turbine blades 34. The relationship of these blades to the stator blades 26 is indicated. Preferably, but not exclusively, each primary turbine blade 34 is fitted with a bi-directional turbine blade 106. To prevent the build-up of accumulated pressure at the base of primary turbine blade 34, a build-up which reduces the efficiency of the rotational movement of blades 34, which, in effect, would be slowed by the capture of wind, bi-directional tubine blades 106 are pivotable at pivot points 218. This pivoting movement is enhanced by the presence of one or more counterweights 210. When primary turbine blades 34 are positioned on high pressure side 122, bi-directional turbine blades 106 pivot open, so as to allow passage of air thereby as indicated by the directional arrows provided, thus reducing or eliminating an undesirable back-up of air pressure.
Wind passage and direction is critical to the efficient operation of windmills. Accordingly, wind pressure edges 204 of primary turbine blades 34 are provided with high pressure piezoelectric deflector benders 206 which are comprised of material exhibiting the piezoelectric effect, i.e., the material can be distorted through selective and controlled input of electrical pulses. Said distortion directs the wind to pass by bi-directional turbine blades 106, thereby increasing the efficiency of the present device. Furthermore, to allow wind passage, a high pressure piezoelectric inlet bender 208 is provided on the back side of each primary turbine blade 34.
Referring now to FIG. 4, there is shown a plurality of primary turbine blades 34 and related members. According to this view, there is shown a low pressure side, generally indicated by 116, which indicates the passage of air from the invention as illustrated by the directional indicators provided. The bi-directional turbine blades 106 are pivoted in the direction opposite that shown in FIG. 3 to allow the passage of air from the invention. Additionally, low pressure outlet piezoelectric benders 226 are provided to facilitate more efficient movement of wind.
In operation, the windmill receives incoming wind at its high pressure side 122. The wind processing blades 28 and stator blades 26 are adjusted so as to maximize the flow-through of air, as are the piezoelectric devices provided on primary turbine blades 34, all of which are remotely operated by means known in the art. The fluid-containing flywheels 20, 48 provide a harmonic stabilizing or dampening effect. The fluid is allowed to proceed, from level to level, through openings 362 as speed dictates. Power is generated by generator means 14 as shaft 50 and its associated primary turbine blades 34, flywheels 20, 48, and support structures 46, 47 rotate as a unit. Braking or slowing is accomplished mechanically by operation of disc brake assembly 22.
When not in use or when preferred, wind processing blades 28 may be rotated by means of wind processing blade position drives 30 so as to effectively enclose the operating elements of the invention. To further enhance the energy-producing characeristics of the invention, the outer sides of wind processing blades 28 are preferably, but not necessarily, provided with solar energy collecting devices (not shown).
The invention described above with reference to the attached figures is not meant to limit the interpreting of the claims to any particular embodiment of the invention claimed. Furthermore, it is contemplated that various modifications may be made to the invention while still remaining within the scope of what is claimed below. | The present invention discloses a windmill capable of utilizing a broad range of wind speeds, comprising, a central axial shaft, a first flywheel attached to the upper portion of said central axial shaft, a second flywheel attached to the lower portion of said central axial shaft, a plurality of rotor blades operably connected to said first flywheel and said axial shaft, a supporting structure for rotatably supporting said shaft, a top structure and a base structure, a plurality of stator blades movably fitted between said top structure and said base structure, said stator blades being capable of rotational, inward and outward movement relative to said axial shaft, and a plurality of wind processing blades rotatably fitted between said top structure and said base structure. | 8 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to an inert gas debris removal subsystem to carry off particulate contaminants from the radiation-ablated region of a substrate being treated in a photo-ablation system. and specially relates to such a subsystem with multiple chambers having openings which meter a flow of inert gas in a plurality of chambers through openings for controlled partial pressure differentials in such chambers for particulate-flushing gas flow which does not interfere with the ablation beam or cause contaminant build-up.
(2) Description of Related Art
Semiconductor devices and integrated circuits are manufactured using multiple layers of different types of materials. These conductive, semi-conductive and insulation type material are deposited or formed on substrate, semiconductor die, wafer, may be used even simply on their own. The predetermined patterns for packaging electronics, biomaterials, etc are then made by removing material by etching, photolithography, photo-ablation, or other material removal techniques. During photo-ablation, the resonant energy is directly coupled into bond vibrational frequencies. This is done by quickly forcing violent vibrations between atoms so that the bonds break.
A by-product of the laser ablation process is the formation of laser “debris.” The material that is ejected by the laser ablation process consists of gaseous by-products, carbon, and polymer fragments. It is shown that the macroscopic debris does not appear until more than 0.5 μs after the laser pulse is incident on the surface. Since the excimer laser pulse widths are typically less than 50 ns, the ejected debris does not interfere with the incoming light.
The functionality of the imaging is reduced by gaseous and particulate matter and the contamination of the lens elements with the out-gassed particles from the substrate will cause lens distortion and scattering of light from the lens element. Gaseous materials are relatively easier to remove using vacuum, compared with the solid debris material, which is of a greater concern if left unattended. The solids contribute to greater contamination of the surface and may also interfere with incoming light from subsequent pulses. It is therefore advantageous to remove as much as possible of the ejected debris from the ablation area before the next laser pulse begins. Vacuum alone is typically not strong enough to remove the debris from the large volume above the exposed area. A system consisting of forced gas such as nitrogen or helium combined with an exhaust is devised to minimize the effects of the debris and ensure that the exposure site is free of debris prior to the arrival of the next laser pulse.
One common practice for carrying off ablation debris involves the use of an inert gas flow across the laser ablation site. Flushing with an inert gas, or with a semi-inert gas such as nitrogen, is intended to prevent oxidizing reactions, cooling the plume and substrate, and flushing the ablated material away from the ablation site.
Without debris elimination, large carbon fragments can agglomerate or be redeposited into an area under exposure. Most redeposited fragments can be ablated by subsequent pulses. However, under certain conditions (laser fluence, particle dimensions, and mask defects) some of the fragments may be too large for the laser to remove. Under these circumstances, the carbon cluster will prevent ablation of the polymer layer beneath, which results in a carbon-encapsulated “cone” of un-ablated polymer. The task of effectively removing debris becomes even more challenging where vacuum chucks are employed to hold down the substrate material due to the peeling effect of flexible substrates. These issues pose serious reduction in throughput due to reduced efficiencies of the laser in removing material and producing cleaner vias. However, this invention discloses a vacuum debris removal system designed right around the ablation site to work optimally between pulses to effectively remove debris material to produce clean features without affecting the position of a flexible substrate coating.
BRIEF SUMMARY OF THE INVENTION
This invention provides a vacuum debris removal system which can continuously remove debris and gases from the process region. The design of the vacuum debris removal system is such that it envelopes the process region, and especially the ablation site on the currently-positioned substrate, concentrically. This allows the radiation beam to be centered in a relatively large opening about the ablation site, so the radiation beam can go through the center of the radiation site opening while the flushing gas and particulates flow about the inner periphery of the radiation site opening. This concentric configuration enables rapid debris removal between pulses and provides a debris-free region for effective material removal using a laser. The flow is directed by differential vacuum partial pressure, and conductances all the way from vacuum pump (lowest partial pressure) to the orifice around the ablation site is designed and calculated such that an optimal speed and vacuum pressure for effective removal is obtained. The throughput of the process is related to speed of traversal and by the rate of ablation or other removal process, but they in turn depend directly on the effective removal of microscopic material before they agglomerate into macro particles and hinder material removal.
An object of this invention is to enable the cost-effective fabrication of microelectronic packaging products, biomaterials, micro-fluidics, and thus to enable high throughputs.
A feature of this invention is the use of multiple chambers with metering orifices to optimize vacuum partial pressure differentials for the desired sweeping flow. However, this also enables customization for different substrates held by vacuum chucks, and deliver optimal vacuum partial pressures for effective debris removal.
Another feature of this invention is that it provides a clear path for the radiation of the ablation beam to go right through the center region of the debris removal region. This is of prime concern due to the ineffectiveness of the debris removal systems acting across the ablation site from the sides.
Another feature of the system is that it is designed to surround the ablation site and the chambers of the ablation region from all sides, making it the most effective design for debris removal.
Another feature of the invention is the provision for the movement of the debris removal system from the surface of the substrate. This is crucial in optimizing for varying substrate surface materials, particle ejection characteristics and substrate peeling from the substrate vacuum chucks (prevalent in any processing industry).
An advantage of this invention is that a virtual chamber formed by the closely-spaced current substrate and the bottom surface of the adjacent metering chamber enclose an envelope of sweeping gas around the ablation site, which keeps ablation debris from escaping to another location on the substrate, but Instead curtail ablation particulate drifting and deliver ablation particulates from the current substrate into the mouth of the ablation orifice in the adjacent metering chamber.
Other objects, features, and advantages of the invention will be apparent from the following written description, claims, abstract, and the annexed drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a partially-sectioned view of the vacuum debris removal subsystem, showing the sweeping gas entry chamber, debris exhaust chamber, and low partial pressure vacuum pump connection chamber, plus a virtual centripetal sweeping gas chamber formed by the current substrate and the facing bottom surface of the sweeping gas entry chamber.
FIG. 2 shows the operation of the vacuum debris removal system, showing the three sweeping gas metering chambers R 1 , R 2 and R 3 and the virtual centripetal sweeping gas chamber vR 4 . The debris exhaust chamber R 2 is connected to the vacuum pump and a sweeping inert gas inlet is connected to the sweeping gas entry chamber R 3 . In this case, the sweeping gas is shown as Helium.
FIG. 3 shows logically the connections between the three metering chambers of the debris removal subsystem and the flow pattern, in which O 1 , O 2 , O 3 and O 4 represent the composite effect of orifices connecting R 3 , R 2 , and R 1 , and between R 1 and R 2 respectively.
FIG. 4 shows flow through orifice between chambers maintained at diminishing partial pressures P 1 and P 2 .
FIG. 5 shows a schematic of pressure differential of the chamber R 3 expunging inert gas. In this case Helium.
FIG. 6 illustrates the flow of inert sweeping gas from R 3 , debris and gases into chambers R 1 and R 2 .
FIG. 7 illustrates the flow of the mixture of sweeping gases and particulates settled into chambers R 1 and thence into R 2 , and to some extent passing into R 2 directly, exhaust chamber R 2 being connected to the vacuum pump which maintains lowest partial pressure. Individual items and representative individual items in groups of such items, are shown in the following table:
debris collection chamber (R1) 1
debris exhaust chamber (R2) 2
sweeping gas entry chamber (R3) 3
representative atmospheric pressue metering hole 4
ablation opening 5
ablation radiation beam 6
ablation site 7
ablation opening riser tube 8
representative bypass metering hole 9
0 representative direct metering hole 10
1 exhaust outlet 11
2 housing 12
3 housing window seal 13
4 housing window 14
5 currently positioned substrate 15
6 sweeping gas inlet 16
7 representative housing chamber seal
8 representative particle 18
9 virtual sweeping gas chamber vR4 19
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a sectional view of the vacuum debris removal subsystem in context of a photoablation system. A clear path for the ablation radiation beam, which typically is ultraviolet radiation, and may be generalized in discussion as “UV” or simply “light.” This light could preferably be from an excimer laser or other type of pulsed laser source. The ablation radiation beam 6 is provided generally along the axis line, essentially the centroid of the ablation opening 8 , which provides access to the ablation site 7 through all four intervening chambers.
Chamber 1 , otherwise called the debris collection chamber R 1 , acts as the turbulence eliminating low pressure region directly in line but most remote from above the processing area, ablation site 7 . Its large volume and relatively low partial pressure permit particulate debris to slow down and be carried through the only slightly larger metering holes 10 to the debris exhaust chamber R 2 .
Debris exhaust chamber 2 is connected to the vacuum pump (not shown) through the exhaust outlet 11 which maintains vacuum partial pressure at the lowest level in all of the debris removal subsystem. The air film above the processing region 7 of the current substrate 15 , which is so closely adjacent to the bottom surface of housing 12 as to form a virtual chamber vR 4 about ablation opening 5 .
Chamber vR 4 is identified as virtual sweeping gas chamber vR 4 at reference numeral 19 in the chart. The entry path of the sweeping gas flows circumpetally, that is, radially into ablation opening 5 and away from the substrate 15 in ablation opening riser tube I 8 . Because the sweeping gas, now carrying particulate matter and gaseous exhaust, enters into the lower partial pressure of debris collection chamber 1 , the flow follows the walls of ablation riser tube 8 , leaving little interference with the ablation radiation beam 6 , which follows the axis at a central position.
The sweeping gas with its gaseous and particulate products, collectively “waste,” is sucked primarily into debris exhaust chamber 1 , and to a lesser extent, bypasses chamber 1 and passes directly into debris exhaust chamber 2 .
Sweeping gas entry chamber 3 is connected to an inert gas inlet 16 supplying inert gas at high partial pressure. The sweeping gas is typically one or a mixture of air, nitrogen and helium. Helium is preferred in our embodiment. The sweeping gas, already reduced to a relatively high partial pressure, is fed through multiple atmospheric pressure metering holes 4 . The sweeping gas forms an enveloping gas virtual fence around the process region ablation site 7 over the substrate 15 . The combination of inert gas, debris particles 18 and air are all removed circumferentially out through the ablation opening 5 between chamber 2 and extension of chamber 1 and through the chamber 2 . This keeps the light path clear from any debris, under uniform gas density and free of turbulence.
Holes 9 and 10 are used to provide metering gas flow. This flow, in the direction of diminishing partial pressure, constantly but slowly passes from chamber 1 , which is sealed away from chamber 2 by o-rings 17 .
Interim Summary of Structure and Method of Operation
The nested chambers provide a balanced path between:
(First) high velocity sweeping gas flow to carry debris particles 18 from the processing area ablation site 7 ; and
(Second) steady, uniform density and non-turbulent sweeping gas flow with particulate debris particles 18 flowing through metering holes 9 - 10 , which are only slightly larger than the larger expected debris particles 18 .
This method ensures high conductance, and provides the most effective debris 18 removal without contaminating the surrounding optics. Clear optical window 14 is provided on top of the chamber 1 housing 12 and held in place by a housing window seal 13 , which in turn seals the chamber 1 away from atmospheric pressure.
Scientific Discussion
FIG. 2 shows a schematic of the vacuum debris removal subsystem of FIG. 1 . FIG. 2 will be helpful for conductance computation, which will follow in the written description text and in the following figures. The flow pattern is clearly illustrated where an envelope of gases from sweeping gas entry chamber 3 would hit the surface of substrate 15 and surround the processing region ablation site 7 . The sweeping gas flows through ablation opening 5 and in small measure through bypass metering holes 9 into debris exhaust chamber 2 , and primarily through region above ablation opening 8 into debris collection chamber 1 . The sweeping gas loses turbulence and any passenger particulate debris settles down in the large debris collection chamber 1 . The sweeping gas and passenger particles 18 continue into the debris exhaust chamber 2 , through direct metering holes 9 and 10 . Desired partial pressures are listed as well as the vacuum pump connection 11 and sweeping gas inlet connection 16 .
The chambers 1 , 2 and 3 will also be referred to as R 1 , R 2 and R 3 respectively for ease of understanding, especially with respect to formulations.
Conductance of vacuum line leading to the vacuum debris removal system shown in FIGS. 1 and 2 is based on achieving low pressure. In order to achieve low pressure in a vacuum line, gases must be removed by pumping each molecule out; as it is removed it must flow from one end of the tube to the other. The rate of flow of a gas, called the throughput Q, is defined as
Q = P ⅆ V ⅆ t
where P is the pressure at which it is measured, and dV/dt is the volume flow rate. Notice that throughput does not have the same units as ordinary gas flow rate (unit volume/unit time). The units of throughput are pressure×volume/time or energy/time, that is, L atm min −1 (sometimes Torr L/sec or in SI units, Pa m 3 s −1 , or J s −1 , or watts). The throughput depends directly on the resistance to flow and the pressure drop between the entrance and exit to a tube or channel:
Q = P 2 - P 1 Z = C ( P 2 - P 1 )
where P 1 is the downstream pressure (measured at the exit). P 2 is the upstream pressure (measured at the entrance), Z=1/C is the resistance and C is the conductance. The conductance is the throughput per unit pressure difference between the tube entrance and exit. The units of conductance are the same that of volume rate or pumping speed, so conductance can be expressed in L/min, L/sec, m 3 /hour, etc. Therefore, the cumulative conductance is calculated as
1 C T = 1 C 1 + 1 C 2 + 1 C 3 + …
The nature of gas flow through a tube is quite different at low pressures than at high pressures. In addition, the flow characteristics depend on the flow rate and the geometry of the tube, pipe, chamber or channel through which the gas flows. Three kinds of flow are recognized: turbulent, viscous (laminar), and molecular. The rough ranges of flow for each are summarized in the table.
TABLE 1 Summarizes the types of gas flow and their range Flow Type Pressure Reynolds No. Knudsen No. Turbulent High >2200 — Viscous Medium <1200 <0.01 Molecular Low — >1.00
As a result, at any pressure in Molecular Flow, the conductances of tubes, valves, traps, and other passive components is constant and at their lowest value. In Transition Flow, the conductance increases non-linearly as the pressure increase. In Continuum Flow (viscous flow) the conductances increases linearly (and sharply) with pressure. At atmospheric pressure, a particular component's conductance may be 10 4 times higher than its Molecular Flow value
In the region of viscous flow about 10 −3 Torr, gas properties depend upon collisions between molecules, which occur much more frequently than between molecules and their container. For viscous flow, the Poiseuille equation gives the throughput through a straight tube of circular cross section.
Q = π d 4 128 η l P ave ( P 2 - P 1 )
Where d and l are the tube diameter and length, η is the gas viscosity, and P ave is the average of P 2 and P 1 . If we combine equations, we obtain an equation for the viscous flow conductance in a tube of circular cross section:
C = π d 4 128 η l P ave
Note that unit of viscosity is the CGS unit, the poise: 1 poise=1 g cm −1 sec −1 . The SI unit is the Pa s: 1 Pa s=1 kg m −1 s −1 . Thus 1 poise=0.1 Pa s. The viscosity of air at 25° C. is 1.845×10 −4 poise=1.845×10 −5 Pa s. If d and l are given in centimeters and P ave in torr, then conductance of tube, C in L/sec for air at 25° C. is:
C
=
182
d
4
l
P
ave
FIG. 3 shows logically the connections between the three chambers of debris removal system for conductance computation in the following sections. Flow schematic for the debris removal system between the chambers and the substrate is shown, which will be used to compute effective conductance of the system. Here Inert gas from 3 flows through orifice O 1 and forms an envelope around the process region 7 and flows both through orifices O 2 and O 3 into region 2 and 3 respectively. Which in turn is connected to each other though orifice O 4 . The vacuum pump 11 exhausts debris and gas mixture from the region 2 . The concept of choked flow between these orifices is explained below. The conductance computation example along with the formulations will be further employed to describe the invention.
Critical Pressure—Choke Flow
P
1
P
2
=
(
γ
+
1
2
)
(
γ
γ
-
1
)
,
γ
air
=
1.4
,
γ
He
=
1.63
=
1.829
••••••••
air
=
2.03093
He
=
0.528
air
=
0.4928
He
Critical
ratio
Pressure
≈
0.5
(
mixture
)
FIG. 4 shows orifices and flow through two sections maintained at pressures P 1 and P 2 . For an orifice area A in cm 2 and for viscous flow the following equations (after Prandtl) apply to air at 25° C. where δ=p 2 /p 1 .
C = 76.6 δ 0.712 1 - δ 0.288 A 1 - δ ℓ s for δ ≥ δ cr C = 20 A 1 - δ ℓ s for δ ≤ δ cr C = 20 A ℓ s for δ ≥ 0.03 δ cr =( p 2 /p 1 ) cr =0.528 (Critical pressure for air)
Flow is choked at δ≦0.528 gas flow is thus constant.
FIG. 5 shows high pressure inert gas from 16 expunged out on to the substrate through orifices 4 . Flow through region 3 towards 7 is maintained at pressures P 1 and P 2 .
Atmospheric pressure=14.69 psi
P 2 P 1 = ( 14.69 30 ) = 0.4903 < 0.5 Choked flow
Using conductance formulation of the orifice
C = 20 A 1 - δ ℓ s for δ < δ cr = 39.24 A ℓ s = 39.24 π ( 0.07874 ) 2 4 = 0.1910 ℓ s
Cumulative conductance of 45 orifices from chamber R 3 to substrate, all in parallel to each other.
C =45 (no. of orifices)*0.1910=8.6 l/s
FIG. 6 shows flow through two chambers from the surface of the substrate. Chambers R 3 , R 2 and R 1 are maintained at pressures P 1 , P 2 and P 3 respectively. The effect of low pressure gas in 1, the chamber R 1 is understood by considering two cases, a) Gas at 300 torr and b) Gas at atmospheric pressure. The range of
Case (a)
Considering 30 psi=155*10 4 mTorr envelope pressure
P
3
P
1
=
(
76
*
10
4
155
*
10
4
)
=
0.4903
<<
0.5
Choked
Flow
(
i
)
P
2
P
1
=
(
100
155
*
10
4
)
=
0.0000645
<<
0.5
Choked
Flow
(
ii
)
Case (b)
Considering 14.5 psi=76*104 mTorr atmospheric pressure
P 3 P 1 = ( 300 76 * 10 4 ) = 3 .947 * 10 - 4 << 0.5 Choked Flow ( i ) P 2 P 1 = ( 100 76 * 10 4 ) = 1 .315 * 10 - 4 << 0.5 Choked Flow ( ii )
From conductance through orifices discussed above
C
=
20
A
1
-
δ
ℓ
s
for
δ
<
δ
cr
Case (a)
=39.2387 *A 2 =52.08 l/s [ A 2 =□(1.3) 2 /4=1.3273] (i)
=20.00129 *A 3 =11.86 l/s (ii)
Case (b)
=20.00789 *A 2 =26.55 l/s [ A 3 =2□(1.3)/2*0.1452=0.593] (i)
=20.00263 *A 3 =11.86 l/s (ii)
case (a) or (b) envelope pressure or no pressure
C=52.08 l/s into chamber R 1 (i)
C=11.86 l/s into chamber R 2 (ii)
FIG. 7 shows the flow from the inside of the region 1 from the side orifices 9 and top orifices 10 into the region 2 . The chambers R 1 and R 2 are maintained at pressures P 1 and P 2 repectively.
Orifice from chamber R 1 to R 2
P 2 P 1 = ( 100 76 * 10 4 ) = 0.33 < 0.5 Choked Flow C = 20 A ℓ s for δ < 0.03 = 20 A ℓ s = 20 π ( 0.15875 ) 2 4 = 0.3958 ℓ s
Cumulative conductance of 48 orifices from region R 1 to R 2 , all in parallel to each other.
C =48 (no. of orifices)*0.3958=19 l/s
The overall conductance of the system is computed with the required conductance from the module connected to vacuum pump is represented as C VP which incorporates pumping speed and conductances of valves, filters etc. The boxes 1 to 8 of the schematic diagram shown in figure represent module independent of the DRS model design.
C VP =C (from Sbst→R 1 →R 2 )+ C (from Sbst→R 2 )
C ( from Sbst → R 1 → R 2 ) = 1 / [ 1 C S → R 1 + 1 C R 1 → R 2 ] = 1 / [ 1 26.55 + 1 19 ] = 1 / [ 1 19 ] Case a : C ( from Sbst → R 1 → R 2 ) = 11.07 ℓ s Case b : C ( from Sbst → R 1 → R 2 ) = 13.91 ℓ s C ( from Sbst → R 2 ) = 11.86 ℓ s Case a: C VP =22.93 l/s and case b: C VP =25 l/s
In fact, reducing the requirement for higher flow rate from the vacuum pump and in turn providing a range of velocities for effective debris removal.
DRS Gap
DRS gap and control of velocity, in turn controlling force required in picking up of debris is equally important in comparison with maintaining of desired conductance.
Throughput Q=C*□P
= C*F/A since, difference in pressure=Force per unit area
F =( Q*A )/ C
=throughput*area/conductance
F∝Q
F∝ 1 /C
F∝A
but
Q∝C
C∝d 4 /l
A∝d 2
It can be said for a constant throughput maintained in the lines and DRS
F∝l/d 2
This is clearly against the requirement for maintaining better conductance. This means that with higher particle ejection rate the increase in particle size makes the conductance and velocity inversely proportional to each other. Thus this unique chamber design accommodates varying velocities and conductance thus delivering a steady state. Optimization over these interdependent chambers for maximizing velocity and conductance and customization depending upon the process, debris size and rate of removal can be done
While the invention has been shown preferably through the embodiments illustrated in the FIGS. 1-7 , it will be clear to those skilled in the art that the modifications described as alternatives, and other alternatives, may be pursued without departing from the spirit and the scope of the invention, as defined in the following claims. | A turbulence-controlled vacuum debris removal subsystem safely exhausts particles ejected during photoablation. Nested interconnected chambers provide diminishing sweeping gas partial pressure and diminishing turbulence, ejecting particles from the ablation beam path between pulses, without compromising continuing particle conductance. Removal rate (debris generation rate) depends on conductance and particle sizes. The chambers interconnect through metering holes which enable optimization of partial pressure differentials. Controlled flow accomplishes debris removal, reducing turbulence of the mixture of debris and sweeping gases. A preferred embodiment uses a nest of concentric chambers, providing a clear light path. Another preferred embodiment uses orifices on chamber faces for removal and forming an envelope of gas around the processing region for dynamically containing the ejected particulate matter from the ablation site to the exhaust. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit and priority of pending U.S. provisional patent application Ser. No. 60/441,336 filed Jan. 21, 2003, entitled “Single Tile Having Two Piece Appearance”. The present application also claims the fill benefit and priority of pending U.S. provisional patent application Ser. No. 60/423,971, filed Nov. 4, 2002, entitled “Method And Apparatus For Providing Multiple Tile Shapes From A Single Tile”. The present application claims the benefit and priority and is a continuation-in-part (CIP) of U.S. Non-Provisional patent application Ser. No. 10/347,663 filed Jan. 21, 2003 now abandoned entitled “Single Tile Having Two Piece Appearance”. The entire contents of the aforementioned two provisional patent applications and one non-provisional patent application are incorporated by reference.
BACKGROUND OF THE INVENTION
Various methods have been employed for making concrete tiles, such as concrete roof tiles. The particular methods used depend on such things as the shape of the tiles being formed. Typically, wet concrete is dispensed onto a moving pallet (a.k.a. “mold”), following which the pallet is passed under a roller and slipper to form and then shape the tile. A knife assembly chops and shapes the opposite edges of the tile. The wet concrete is cured and then removed from the pallet to provide the completed tile.
In a particular known method of making concrete roof tiles, a conveyor is used to transport the wet concrete from either a continuous mixer or a batch mixer to a making head assembly disposed above a conveyor containing a succession of moving pallets, arranged end-to-end. The pallets define the general shape of the tiles to be formed. As each pallet passes within the making head assembly, wet concrete is dispensed onto the pallet, with the help of a rotating roller which meters the concrete onto the pallet and compresses the wet concrete to a desired thickness. The pallet is then passed beneath a slipper which engages the wet concrete and has a profile selected to provide the concrete with a desired cross-sectional configuration. A knife assembly chops the continuous ribbon of concrete formed on the end-to-end succession of pallets to define the individual tiles and to shape the edges thereof. The pallets with the wet concrete extruded, compressed, shaped and chopped thereon are then separated and advanced to a racker, where the pallets are loaded onto racks for transport to a curing facility. The curing facility typically comprises an oven in which the tiles are heated at a desired temperature and for a desired period of time to cure the concrete. Following that, each concrete tile is removed from its supporting pallet to thereby provide the completed concrete tiles.
BRIEF SUMMARY OF THE INVENTION
Generally described, one embodiment of the invention includes the use of an S-Tile mold, including or combined with a scoring, knifing, shaping, or other type of process, which allows for subsequent controlled separation of what would normally be an S-Tile into two separate tile sections having a general C-shaped cross section. This allows for two types of tiles (S-tiles and Two-Piece Mission tiles) to be made from one type of mold (S-tile).
Another embodiment of the invention includes the use of an S-Tile mold, including or combined with a scoring, knifing, shaping, coloring, or other type of process, which allows for an S-Tile to be produced which appears to be two separate tile sections having a general C-shaped cross section, but in fact is a one piece element.
Another configuration of the present invention includes the use of an S-Tile mold, combined with a scoring, knifing, shaping, coloring, or other type of process, which allows for an S-Tile to be produced which appears to be two separate tile sections having a general C-shaped cross section, but in fact is a one piece element. However, this one piece element may be split itself if the need arises.
Therefore it is an object of the present invention to provide an improved method and apparatus for providing roof tiles.
It is a further object of the present invention to provide an improved roof tile and system for using same.
Other objects, features, and advantages of the present invention will become apparent upon reading the following detailed description of the preferred embodiment of the invention when taken in conjunction with the drawing and the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 is a pictorial view of a “modified” S-tile 5 , which includes sections 6 and 7 . Also provided is a rectangular-type channel 9 . This channel may be used as a breakage channel (to separate sections 6 and 7 ), or to simulate a dual-tile configuration (appearing to be two separate tiles). Exemplary nail holes NH 1 and NH 2 are also shown. This figure also shows optional items NH 3 and score line (or channel) 99 .
FIG. 2 is an end view of the tile of FIG. 1 . Exemplary support ribs, barely shown in FIG. 1 , are better shown as 6 R and 7 R in this figure. In this preferred embodiment, two substantially parallel ribs are used as a pair, with one each of each pair shown in FIG. 2 . These ribs are also shown in FIG. 6 ; note a pair is used at one end and a single rib is used at the other end.
FIG. 3A is a pictorial view of a modified slipper design 30 configured for use with the invention.
FIG. 3B are illustrative views of possible blade shapes.
FIG. 4 is a pictorial view of a plurality of Two-Piece Mission tiles.
FIG. 5 is a tile 5 according to one embodiment of the present invention, showing nail holes NH 1 and NH 2 , and showing a Head End “H.E.” and a Tail End “T.E.”.
FIG. 6 is the underside of that shown in FIG. 5 .
FIG. 7 is a more detailed view of the tile 5 of FIG. 5 , showing in more detail the location of channel 9 .
FIG. 8 is an illustrative drawing of the channel shown in FIG. 7 . Partial cross hatching is shown.
FIG. 9 is an illustrative drawing of alternate channels 9 ALT. Partial cross hatching is shown.
FIG. 10 is a partial tail (a.k.a., “butt”) end view of an alternate tile 110 having an alternate shape of an interface. As may be seen an overhang is provided which defines a single substantially flat shelf portion 1000 .
DETAILED DESCRIPTION OF THE INVENTION
The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may 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 satisfy applicable legal requirements. Like numbers refer to like elements throughout.
General Description
Generally described, the invention includes several different embodiments or concepts. These embodiments could be thought of as including the following three general categories:
S-Tile molding including separation “treatment” and breakage S-Tile molding including separation “treatment” and no breakage S-Tile molding including separation “treatment” and breakage or no breakage, as needed.
The term separation “treatment” is used to describe scoring, knifing, shaping, coloring, or another type of process, which allows for an S-Tile (a.k.a. “Espana”) to be produced which appears to be two separate tile sections having a general C-shaped cross section (a.k.a. “Mission”) and/or which can actually be separated or “broken” into two tile sections.
Category One
General
This category includes the use of a conventional S-Tile mold, combined with a scoring/knifing or other type of process, which allows for subsequent controlled separation of what would normally be an S-Tile into two separate tile sections having a general C-shaped cross section (a.k.a. Two-Piece Mission Tiles). This allows for two types of tiles (S-tiles and Two-Piece Mission tiles) to be made from one type of mold (S-tile).
More Details
Reference is first made to FIG. 1 , which is a pictorial view of a “modified” S-tile 5 , which includes sections 6 and 7 . Also provided is a separation channel 9 . It should be understood that under one embodiment of the invention, this tile shape would not be installed as a whole on a roofing structure, but would be broken as noted below. However, under another embodiment this tile shape could be so installed as a whole. As described elsewhere, after curing, the tile 5 is intended to be broken along channel 9 so that two Two-Piece Mission tile shapes are provided, corresponding to sections 6 and 7 .
Referring now also to FIG. 2 , which is an end view of the tile of FIG. 1 , the channel 9 is 3/16 inch wide, and 5/32 deep, although other configurations are contemplated without departing from the spirit and scope of the present invention. In an alternate configuration, a knife edge could be used instead of the formed channel.
It should be understood that under one embodiment of the invention, a “shading” treatment could be applied, which involves the use of a small jet to squirt suitable ink onto the score line, as shown generally on the surface 9 S in FIG. 2 . It should be understood that this “shading” treatment could be applied to any of the embodiments of the invention as needed.
It should be understood that a “conventional” S-tile is such as shown in FIGS. 1 and 2 , but without the channel 9 (or knife cut 99 ).
Manufacturing
The overall manufacturing process is as follows. Conventional S-type tiles can be made as needed in a conventional S-tile mold (not shown), with occasionally the modified S-tiles 5 being made. In one example, out of 40,000 tiles being made, the last 10-15% could be modified S-tiles. However, other manufacturing ratios may also be provided without departing from the spirit and scope of the present invention, and may be easily varied as needed to accommodate demand.
The conventional S-tiles will be manually or automatically de-palleted from the mold as is presently done in the art.
In order to “switch over” to Two-Piece Mission type tiles, under one version of the invention, the line is stopped and the slipper configuration is changed. Reference is now made to FIG. 3A , which is a pictorial view of a modified slipper design 30 , which includes a scoring blade 39 , which is configured to form the channel 9 during the forming process. In one configuration the scoring blade is 5/32 inches high, 3/16 inches wide, and 1.5 inches in length, although other configurations are contemplated without departing from the spirit and scope of the present invention. FIG. 3B shows various possible scoring blade configurations 39 A, 39 B, 39 C.
As noted above, under the first embodiment of the invention, in order to use the slipper configuration in FIG. 3 , the line has to be stopped and the slippers exchanged. However, an alternative invention includes the concept of configuring the slipper to allow the blade 39 to be moved up and down such that it scores as desired in one position, but presents a flat surface flush with the slipper in a second position. Another alternative configuration includes not modifying the slipper at all but simply lowering a tool into place downstream of the slipper; this could be done while the line is going.
The tile 5 will be allowed to cure as all other tiles. It will then be hand de-palleted from the mold, broken along the score line and packaged as two separate pieces.
Installation
The smaller tiles 6 and 7 can be installed such as shown in FIG. 4 , which shows a plurality of Two-Piece Mission tiles installed on a demonstration surface.
Category Two
General Description
Generally described, this embodiment invention includes the use of an S-Tile mold, combined with a scoring, knifing, and/or coloring process, which allows for an S-Tile to appear as two separate tile sections having a general C-shaped cross section, by use of a “simulation interface channel” 9 . These tile sections having a general C-shaped cross section may also be known as “mission tiles”.
More Detailed Discussion
Reference is first made to FIG. 5 , which is a pictorial view of a “modified” S-tile 5 , which includes portions 6 and 7 , and defines a head end HE and a tail end TE. Also provided is a channel 9 . It should be understood that under one embodiment of the invention this tile shape is intended for installation as a whole on a roofing structure, simulating two cooperating mission tile shapes.
FIG. 6 is the underside of that shown in FIG. 5 .
FIG. 7 is a more detailed view of the tile 5 of FIG. 5 , showing in more detail the channel 9 .
Referring now also to FIG. 8 , the channel can be 3/16 inch wide, and 5/32 deep, although other configurations are contemplated without departing from the spirit and scope of the present invention, especially if such other configurations are found more structurally and/or aesthetically effective or desirable. This simulation interface channel 9 simulates the interface of two separate tiles corresponding to portions 6 and 7 . It should be understood that this channel may also be painted, colored, or otherwise darkened in order to accent a “shadow” effect which causes the eye to better perceive separation of the two portions 6 and 7 .
Manufacturing Considerations
The overall manufacturing process can be as follows. Conventional S-type tiles can be made as needed in a conventional S-tile mold (not shown), with occasionally the modified S-tiles 5 being made. In one example, out of 40,000 tiles being made, the last 10-15% could be modified S-tiles. However, other manufacturing ratios may also be provided without departing from the spirit and scope of the present invention, and may be easily varied as needed to accommodate demand.
The conventional S-tiles will be manually or automatically de-palleted from the mold as is presently done in the art.
In order to “switch over” to Simulated Two-Piece Mission type tiles, under one version of the invention, the line is stopped and the slipper configuration is changed. Reference is now made to FIG. 3A , which is a pictorial view of a modified slipper design 30 , which includes a scoring blade 39 , which is configured to form the channel 9 during the forming process. In one configuration the scoring blade is {fraction 5/32)} inches high, 3/16 inches wide, and 1.5 inches in length, although other configurations are contemplated without departing from the spirit and scope of the present invention.
As noted above, under the first embodiment of the invention, in order to use the slipper configuration in FIG. 3A , the line has to be stopped and the slippers exchanged. However, an alternative invention includes the concept of configuring the slipper to allow the blade 39 to be moved up and down such that it scores as desired in one position, but presents a flat surface flush with the slipper in a second position. Another alternative configuration includes not modifying the slipper at all but simply lowering a tool into place downstream of the slipper; this could be done while the line is going.
Curing and Installation
The tile 5 will be allowed to cure as all other tiles, and can be installed in the same manner as a conventional S-tile. However, should the need arise, the channel could be used as a break line should the installer need a half tile width at the end of a course of tiles.
Alternatives
There are many alternative channel configurations which may be used. The rectangular channel may be used as shown in FIG. 8 , or alternative channel shapes such as shown in FIG. 9 or 10 may be used. Knife cuts could also be used.
Category Three
The present invention also contemplates the use of tiles such as described above which can be used as either a “breaking” tile or a non-breaking tile, purely at the decision of the installer.
Variations
Under another variation, a portion of the cap part of the S tile is installed on top of a cap on a regular S tile, which could be considered a “boosted” tile. This gives the appearance of an “old world” installation. Reference is made back to FIG. 1 . Under this version, the same channel 9 as before is provided. However there is also applied a second channel or knife cut 99 to the cap portion of the S tile perpendicular to the length of the tile and about 3½″ from the top of the tile, although other lengths may be provided without departing from the sprit and scope of the present invention. This knife cut is provided by a transverse knife edge coming down from above at a suitable location. An additional nail hole NH 3 is also applied in the cap portion of the tile approximately 4″ from the top (although this could also be varied). The knife cut only cuts about halfway through the concrete and acts like a perforation. When the tile is de-palleted and loaded on the roof, the roofer breaks the tile down the middle using the first score line (or channel). Then he breaks the top off using the perforation/score line of the second knife cut. The remaining piece (the one with the nail hole NH 3 ) can then be installed on top of the cap of an installed S tile with mortar to give it an “old” look. The additional nail hole NH 3 is for a wire clip to provide a mechanical attachment, as well as the mortar.
In this alternate configuration as may be seen there will be three tile members provided after the double breaking process; a long pan piece, a medium length cap piece, and a short cap piece. The long pan piece may be used as a course starter, and the shortest piece may be used either as a double boost element (stacking even higher on top of the medium length piece) or as needed in a hip stack environment.
It should be understood that other tile profiles could be used without departing from the spirit and scope of the present invention. For example, other types of back-supporting ribs could be used. Knife cuts could be used to provide channels such as 9 .
It should also be understood that etching or any type of chemical/fluid treatment could be used to provide the breakage line (a.k.a. “breakage treatment”). However, this would need to be done after the tile has cured.
CONCLUSION
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | According to various embodiments, methods, apparatuses, and products are provided that use an S-shaped die mold and a scoring/knifing process to produce two types of dies (S-shaped tiles and C-shaped tiles) from the S-shaped tile mold. The scoring/knifing process forms one or more channels or other suitable shapes in the S-shaped tile. At least one of the channels creates the appearance that the S-shaped tile comprises two separate and cooperating tile sections, each having a generally C-shaped cross section. In a further embodiment, at least one of the channels may be painted, colored, or otherwise darkened to accent a “shadow” effect, further creating the appearance that the C-shaped portions of the S-shaped tile are separate. In another embodiment, a method is provided that allows the S-shaped tiles to be broken or not broken along one or more of the channels, depending on the installer's preference. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage of International Application No. PCT/CA2013/000434, filed on 1 May 2013. International Application No. PCT/CA2013/000434 cites the priority of U.S. Patent Application No. 61/642,585, filed on 4 May 2012.
FIELD OF THE INVENTION
The present invention relates to ice resurfacers. More specifically, the present invention relates to systems, methods and devices for recycling snow and ice shavings from an ice rink for ice resurfacing.
BACKGROUND OF THE INVENTION
To maintain their optimum usefulness, all ice rinks require maintenance. Ice skates, by their very nature, are destructive to ice rinks as skates will score, scratch, and cut the ice on an ice rink. In addition to this, continued use of ice skates on an ice rink will cause the accumulation of slush, snow and dirt. It is, therefore, necessary to quickly and effectively resurface the used ice using minimal energy and resources. During rink maintenance, an ice resurfacer shaves a relatively thin layer ( 1/16-inch to ⅛-inch) of ice from the ice surface. The resulting ice shavings and snow is then collected and directed through a series of horizontal and vertical augers into the snow dump tank receptacle. As this is occurring, the ice resurfacer deposits on the surface of the rink a layer of fresh hot water which fills cracks and imperfections on the ice surface. Currently, after the ice resurfacer finishes its operation, the contents of the snow dump tank is disposed of inside or outside of the rink (for example, the content of the snow dump tank is often dumped outside of the ice rink building).
During the above operation cycle, a substantial amount of energy, labour, material and fresh water are used. For example, every time an average sized ice rink is flooded, it requires the use of approximately 200 to 700 liters of fresh water heated to a temperature of between 50 and 60 degrees Celsius. This large quantity of water must first be heated in a large commercial external hot water tank and, once heated, the water is then sent to another large commercial hot water holding tank. The heated water is stored so that it remains heated between resurfacing periods. The ice resurfacing and cleaning machine is manually filled with the hot water by a worker using a hose before ice resurfacing. The process thus requires material, labor, fresh water and additional energy before each ice resurfacing cycle.
Zamboni® and Olympia® are well-known brands of ice resurfacers.
Various machines have been proposed which use different heat sources to melt snow and ice shavings for water re-use. Examples of these machines include those disclosed in U.S. Pat. Nos. 7,380,355, 5,536,411, and 3,705,746. Different approaches include utilizing heat from the burning of a combustible fuel material, recovering heat from a refrigeration unit, or rejecting heat from the machine drive engine. While some of these approaches have advantages, most have not been adopted for use by ice resurfacers. As well, none of these approaches have been truly economical as they would require redesign and replacement of current ice resurfacers.
Based on the above, there is therefore a need for methods, systems, or devices which would mitigate if not overcome the deficiencies of the prior art.
SUMMARY OF INVENTION
The present invention provides methods, systems, and devices relating to ice resurfacers. A retrofitted ice resurfacer has a snow tank for storing ice shavings, an active heating system for melting the ice shavings, a filtration subsystem for filtering the melted ice shavings, a main water tank for storing the filtered water from the melted ice shavings, and a water tank heating subsystem for heating the main water tank. The ice resurfacer scrapes a layer of ice from the ice rink and the resulting ice shavings are dumped into the snow tank. The ice shavings are then melted using the active heating subsystem. The melted ice is then stored in the main water tank. In a preferred embodiment, the water is filtered and purified prior to being stored in the main water tank. While in the main water tank, the filtered and purified water is heated to a specific temperature. The heated filtered water is then re-used by the ice resurfacer when resurfacing the ice surface. Alternatively, the heated water in the main water tank can be filtered and purified prior to re-use.
In one aspect, the present invention provides a system for recycling water derived from ice from an ice rink, the system comprising:
a snow tank for ice shavings removed from said ice rink by an ice resurfacing machine; a heating subsystem for heating said ice shavings to thereby melt said ice shavings and produce water; a filtration subsystem for filtering water resulting from melted ice shavings and to thereby produce filtered water; a main water tank for receiving and storing filtered water from said filtration subsystem; a water tank heating subsystem for heating stored filtered water in said main water tank to produce heated water; a conduit system for routing heated water from said main water tank for use in resurfacing said ice rink;
wherein said system is located on said ice resurfacing machine.
In a further aspect, the present invention provides a method for modifying an existing ice resurfacing machine, the method comprising:
replacing and/or modifying an existing snow tank by (for example, by cutting out a hole for hopper and couplers to allow said snow tank to be in flow communication with a main water tank); installing a heating subsystem for heating ice shavings in said snow tank; installing a filtering subsystem, said filtering subsystem being for filtering water produced when said ice shavings are heated by said heating subsystem to produce filtered water and for directing the filtered water to a main water tank; replacing and/or modifying a main water tank, for example, by creating a hole in the top of the tank to fit the hopper assembly, creating one or more holes for the couplers, and removing and/or modifying the baffle to accommodate the piping; installing a water tank heating subsystem, said water tank heating subsystem suitable for heating filtered water in said main water tank.
In an additional aspect, the present invention provides a method for recycling water derived from ice shavings from an ice rink, the method comprising:
a) scraping ice shavings from a surface of an ice rink;
b) placing said ice shavings in a snow tank;
c) applying heat to said ice shavings to thereby melt said ice shavings and produce water;
d) directing water produced in step c) to a filtering subsystem;
e) filtering and purifying said water in said filtering subsystem to produce filtered water;
f) directing said filtered/purified water to a main water tank;
g) heating said filtered water to a predetermined temperature to produce heated filtered water; and
h) using said heated filtered water to resurface said surface of said ice rink.
In accordance with another aspect, the present invention provides a kit of parts for converting an existing ice resurfacing machine, the kit comprising:
a heating subsystem for heating an existing snow dump tank on said ice resurfacing machine, said heating subsystem suitable for melting ice and snow collected from an ice rink being resurfaced and stored in said snow dump tank; preferably a filtration and purification subsystem for filtering and purifying water resulting from melted ice and snow; a main water tank heating subsystem for heating a main water tank, said main water tank storing filtered water from said filter subsystem; a power system for providing power to said heating subsystem and said main water tank heating subsystem;
wherein a converted ice resurfacing machine resulting from installing said kit of parts on said ice resurfacing machine uses water recycled from said collected ice and snow to resurface said ice rink.
The present invention is suitable for use in the conversion of existing ice resurfacing and cleaning machines. This potentially reduces the ongoing cost required to maintain and operate such machines. As an example, the majority of ice and skating rinks already utilizes one or more ice resurfacing machines. By converting or retrofitting these machines to recycle the ice gathered during ice resurfacing, the energy, material and labour savings may be significant. These savings may amount to $50,000 to 60,000 USD a year.
The present invention has the potential to provide for a drastic reduction in the fresh water normally required by the ice resurfacing machines between ice rink maintenance periods. As well, converted ice resurfacing machines require less energy and manpower to operate, thereby leading to more savings.
Another advantage of the present invention stems from eliminating the need for two external hot water heating tanks. Currently, one tank is used to heat the fresh water while another tank is used to hold the heated water. The storage tank is kept at a temperature high enough to ensure that sufficient hot water is available for the ice resurfacing machines. Not only does the present invention only use a single tank, but in doing so, it also eliminates the wasted energy that would have been used by the two external hot water tanks.
The foregoing advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the present invention will now be described by reference to the following figures, in which identical reference numerals in different figures indicate identical elements and in which:
FIG. 1 represents a basic overview of the retrofitted ice resurfacing system.
FIG. 2 represents a detailed overview of the retrofitted system.
FIG. 3 represents the metal grate system installed in the snow dump tank receptacle for melting the collected ice and snow shavings.
FIG. 4 represents the hopper device for connecting the snow dump tank to the main water tank, and the main water tank that has been insulated and retrofitted with a heating device.
FIG. 5 represents of a schematic of the power system used to operate the heating devices in the retrofitted snow resurfacing machine.
The Figures are not to scale and some features may be exaggerated or minimized to show details of particular elements while related elements may have been eliminated to prevent obscuring novel aspects. 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 to variously employ the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The terms “coupled” and “connected”, along with their derivatives, may be used herein. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may be used to indicated that two or more elements are in either direct or indirect (with other intervening elements between them) physical or electrical contact with each other, or that the two or more elements co-operate or interact with each other (e.g. as in a cause and effect relationship).
An overview of a retrofitted ice resurfacing machine system for reusing collected snow and ice shavings for further ice resurfacing is shown in FIG. 1 . The system includes an existing ice resurfacing machine 100 . Inside the ice resurfacing machine is a snow dump tank 110 , a snow tank heating subsystem, a filtering assembly 130 (which connects to and allows flow communication between the snow dump tank and a main water tank 140 ), the main water tank 140 , a main water tank heating subsystem 150 , and a power system 160 .
An explanation of the ice resurfacing machine 100 illustrated in FIG. 1 can be better understood in conjunction with the details illustrated in FIG. 2 . Referring to FIG. 2 , the ice resurfacing machine 100 is equipped with a conditioner 170 . As the ice resurfacing machine 100 moves in a forward direction across an ice surface, the conditioner 170 is lowered to the ice surface (usually hydraulically lowered). Within the conditioner 170 is a blade 180 which is lowered to an industry standard height from the ice surface (usually manually lowered). The blade 180 shaves a thin slice off the ice surface. A series of coupled augers (horizontal augers 190 and vertical augers 200 ) collect the ice and snow shavings 210 and convey and deposit these to the snow dump tank receptacle 110 mounted on the ice resurfacing machine 100 .
In the illustrated embodiment of the present invention the snow dump tank 110 in the ice resurfacing machine 100 has been modified from that of a conventional ice resurfacing machine. The snow dump tank 110 is angled downwardly towards the back of the tank and incorporates a snow tank heating subsystem for melting the ice and snow shavings. The snow dump tank is replaced and/or modified to include holes for the hopper and couplers. Preferably, the snow tank heating subsystem is able to provide enough heat to melt the collected ice and snow shavings 210 into water. In the embodiment shown in FIG. 2 , the snow tank heating subsystem includes a heated metal filter screen 220 , a heated metal grate 230 and at least one heating pipe 240 (the heating pipe or tube may be constructed from any suitable material, including stainless steel, nickel alloys, as well as iron-chromium-aluminium alloys that can be used at temperatures up to 1250° C. (2280° F.)). These various parts are attached to or embedded in the snow dump tank 110 using metal clips, ties or pins. It would be readily apparent to a person skilled in the art that the snow dump tank on an ice resurfacing machine can be modified, as described above, or simply replaced with a snow dump tank adapted to function in accordance with the present invention.
Regarding the snow tank heating subsystem, the various components may be designed for ease of use. For portability and to facilitate easy cleaning and maintenance of the snow dump tank 110 , the heated metal grate 230 may ride on rollers or casters 250 spaced on each side of the heated metal grate 230 to allow it to be easily removed from the snow dump tank 110 . This arrangement is illustrated in FIG. 3 a , a plan view of the grate 230 showing the heating pipes 240 , the casters 250 , and the grate 230 .
Regarding construction, the removable heated metal grate 230 may be made by stitching or welding stainless steel grate pieces together and cutting off the extra pieces depending on the dimensions of the snow dump tank 110 . A person skilled in the art would be well aware that the grate 230 could be constructed from other materials that is heat resistant.
As noted above, in the illustrated embodiment the snow tank heating subsystem includes a removable heated metal filter screen 220 . This may be fastened to the stainless steel circulation heater pipes 240 with metal clips, ties or pins. A plan view of the metal filter screen is provided in FIG. 3( b ) . The removable heated metal filter screen 220 may be constructed from flat stainless steel sheets and is preferably positioned above the stainless steel circulation heater pipes 240 . The filter screen can be removed and cleaned by pulling it out from the front of the ice resurfacing device 100 . This is done by removing the stainless steel straps that are attached the stainless steel circulation heater pipes 240 . The metal filter screen 220 protects the stainless steel circulation heater pipes 240 and also may serve as a first filter to catch large debris such as hockey pucks that may be picked up along with the shaved snow and ice.
Regarding the snow tank heating subsystem shown in FIGS. 2 and 3 a , the removable heated metal grate 230 is heated by the heater pipes 240 . The pipes 240 may be filled with a heated solvent that would flow through the pipes 240 and which would, in turn, heat the pipes 240 , the metal grate 230 and the metal filter screen 220 . This heat will melt the collected ice and snow shavings into water. In one embodiment, the heater pipes 240 are filled with Therminol 75 oil, heated to 200° C. by a circulation heater 245 . Referring to FIG. 3( a ) , the heater pipes 240 are placed and tied down with metal clips, ties, or pins on top of the removable heated metal grate 230 . The heater pipes 240 are vertically spaced from the metal grate 230 and the filter screen 220 . The heater pipes 240 horizontally span from the front of the snow dump tank 110 to the back of the snow dump tank 110 . The number of pipes used can be varied to accommodate different temperatures outside the ice resurfacing device 100 , the amount of ice scraped off the blade, and the industry standard temperature required to clean the ice. The addition of more pipes and spacing the pipes closer to one another on the metal grate 230 would allow for quicker melting of the shaved ice and snow.
Referring to FIG. 2 , the stainless steel circulation heater pipes 240 are heated when the circulation heater 245 , heats the Therminol® 75 oil to 200° C. The heated oil is continuously pumped and circulated through the circulation heater pipes 240 by pump 265 . The circulation heater 245 used in one implementation is a 5 kilowatt Wattco circulation heater model # MFLS605X2421-TM. A person skilled in the art would be well aware that other suitable heaters can be used. A circulation heater pump 330 is used to pump and circulate the oil throughout the system. Preferably, the circulation pump is one which is designed specifically for handling hot thermal fluids. As well, it is preferred that the circulation pump be engineered to allow ambient air cooling while minimizing thermal transfer along the shaft eliminating any need for liquid cooling through their operating range. In one implementation, the circulation pump used is a ZTND model from SIHI Pumps Americas.
The Therminol 75 synthetic heat transfer fluid used in one implementation is composed of Terphenyl/quaterphenyl. This fluid is a high temperature liquid phase heat transfer fluid having excellent thermal stability. In one implementation, the Therminol 75 oil is used in the 5 kilowatt Wattco circulation heaters. Furthermore, a person of ordinary skill in the art would be well aware that other suitable heat transfer fluids may be used, for example, Dowtherm A or G/Therminol 59, 60, LT and VP1. Furthermore, in the event oil is not preferred as the fluid for use in the heating system, an ethylene glycol and water mix may be used.
It should be noted that the snow tank heating subsystem may include components and parts which have not been mentioned. It is to be understood that a skilled artisan will know of other commonly known alternatives and devices which may be incorporated into the present invention.
Once the shaved ice has been melted by the snow tank heating subsystem, the resulting water flows towards the filtering assembly 130 . The water from the melted shaved ice and snow flows into the filtering assembly 130 where the water is filtered and then funneled to the main water tank 140 .
Referring to FIGS. 3-5 , these diagrams detail the various features and components of subsystems which comprise part of the present invention. FIGS. 3 a and 3 b show parts of the snow tank heating subsystem which melts the ice and snow shavings to result in water. FIG. 4 illustrates the main water tank and the filtering subsystem which filters the melted ice to result in the filtered water that is stored in the main water tank.
Referring to FIG. 4 , includes a side view of the main water tank 140 , the main water tank heating subsystem 150 and the filtering assembly 130 is illustrated. The filtering assembly 130 has a filter 270 and a pull out filter casing 280 . The filter 270 may be any filter suitable for filtering the melted water, such as a charcoal filter. The filtering assembly 130 is preferably constructed of a stainless steel frame angled to form a downward pointing funnel shape such that filtered water is directed towards the main water tank 140 . The filter 270 may be placed inside the pull out filter casing 280 . This allows for the easy removal and replacement of the filter 270 from the filter casing 280 . The pull out filter casing 280 is constructed of a stainless steel frame with a pull handle attached to it. Preferably, the junction 290 between the filtering assembly 130 and the main water tank 140 is sealed using a rubber seal, silicone seal, or cork such that the junction is water-tight. The seal can be installed using glue, epoxy, strapping, or any other suitable means for attaching the seal to the main water tank and the filter assembly.
As the melted ice and snow flows as water to the filtering assembly 130 , the melted water is cleaned when it flows through the filter 270 . The filtered water is then gravity fed into the main water tank 140 . The downwardly pointed funnel shape of the filtering assembly assists in the melting of the shaved ice and snow as the large opening of the filter assembly will allow heated air from the heated main water tank 140 to rise into the snow dump tank 110 .
Regarding the main water tank 140 , this may be made of stainless steel. The main water tank 140 of the present invention is equipped to heat the collected melted snow and ice and to keep the filtered water at a specific temperature range. The present invention works with existing, modified and/or re-designed main water tanks. These main water tanks are, invariably, equipped with a water top-up pipe (not shown) should there be a need to use additional water or to top-up any evaporated water as needed.
The main water tank 140 is preferably insulated in order to minimize heat loss so that the water, once heated, stays heated longer in the main water tank 140 . In the illustrated embodiment, the main water tank 140 has insulation 300 . For example, the main water tank 140 can be insulated by first applying a gasoline sealant, such as Red Kote™, and then using a suitable insulator. Preferably, the insulator is a spray foam insulation with an insulation rating between R-12 and R-20. The main water tank is covered with a tank cover 305 made of stainless steel sheet with a cut-out to accommodate the filtering assembly 130 and may be secured to the main water tank 140 with the use of stainless steel self-tapping screws.
The main water tank 140 is equipped with a main water tank heating subsystem 150 to heat the water collected in the main water tank. As can be seen in FIG. 2 , one implementation of the main water tank heating subsystem includes stainless steel circulation heater pipes 310 . These pipes 310 are mounted on stainless steel brackets and are elevated at about 1 inch off the bottom of the main water tank 140 in order to keep the pipes from losing heat to the main water tank 140 . Referring to FIG. 4 , this implementation of the main water tank heating subsystem 150 includes two couplers 325 for the incoming and outgoing circulation pipes 310 . The couplers are welded onto the main water tank 140 to ensure the main water tank 140 is fully sealed. The number of pipes and the spacing can be varied to accommodate the temperature outside the ice resurfacing machine as well as the industry standard temperature required to clean the ice.
In one implementation, the pipes 310 are connected to a 5 kilowatt main water tank circulation heater 320 . The circulation heater can be adjusted to heat the filtered water to any suitable temperature which may be dictated by industry standards. The circulation heater heats the Thermal 75 oil to 400° C. and the heated oil is pumped (using pump 330 ) through the stainless steel circulation heater pipes 310 . The heated oil heats the filtered water in the main water tank 140 to the industry standard temperature of 140° C. (though a person skilled in the art would be well aware that the water in the main water tank can be heated to any desired temperature).
To further clean the filtered water, a water purification subsystem may be used. One such subsystem may use one or more submersible ultraviolet filters. These filters, each of which exposes the filtered water to ultra-violet light to purify the water, may be placed in the main water tank 140 . A person skilled in the art would understand that other suitable purification subsystems could be used in addition to or as an alternative to ultraviolet light, including purification tablets, chemicals and combinations thereof.
Returning to FIG. 2 , a control panel 340 is installed to control the 5 kilowatt heaters 320 and 245 . The control panel may be customized to monitor and adjust the temperature of the heated flowable substance in the pipes 240 , 310 . As noted above, the heated flowable substance may be Therminol 75 oil. The control panel 340 may include individual temperature and high limit controllers for each of the heaters. In one implementation, the Wattco Control Panel Terminal box NEMA 4 model # WT-6272 was used. This device has a moisture resistant enclosure and includes a main 30 A disconnect, 2 digital temperature controllers, 2 high limit controllers, 2 selector switches to be able to manually turn the heaters on-off, 2 red pilot lights which indicate when heater is on, a 240 v/120 v control circuit transformer, and 2 contactors and fuses for 2 loads of 5 kw, 240 v, 3 ph.
Shut off valves may be used to isolate the water for maintenance use.
A separate power system 160 may be required to power the snow tank heating subsystem and the main water tank heating subsystem 150 . The power systems of current ice resurfacing machines use batteries which will not be able to power the heating subsystems. The power system 160 would power the circulation heaters 320 , 245 as well as the pumps 265 , 330 .
Referring to FIG. 5 , a block diagram of the power system 160 is illustrated. In one implementation, the power system 160 includes eight 12V deep cycle batteries 360 . These batteries 360 are connected to two 6000 watt inverters 370 and two 2500 watt inverters 380 . The batteries 360 are also connected to a 300 A alternator 390 which would be used to charge the batteries 360 .
Each of the circulation heaters 320 , 245 is connected in series to a deep cycle battery 360 and by way of one of the 6000 watt inverters 370 .
Each of the pumps 330 , 265 is connected in series to one of the deep cycle batteries 360 by way of one of the 2500 watt inverters 380 .
When the water temperature in the main water tank 140 falls below a specified temperature, a temperature sensor will activate the two 12 volt deep cycle batteries 360 to power up the 6000 watt main water tank circulation heater 320 . The main water tank circulation heater 320 would then heat up the thermal oil. This, in turn, would heat the water in the main water tank 140 to the required industry standard temperature.
In one implementation, the system includes a means for maintaining the temperature of the heated water in the main water tank 140 . When the ice resurfacing machine 100 is parked and shut down, power system 160 can be plugged into an external 220V power source from the arena. A transfer switch 400 and plug 410 can be used as a back up when the ice resurfacing machine 100 is parked and shut down overnight.
If the power output from deep cycle batteries 360 drops below a nominal operating condition, and if the alternator of the ice resurfacer is unavailable because the ice resurfacing machine is not turned on, the transfer switch 400 would engage the external power source by way of the plug 410 to charge the batteries 360 while the water is being heated up.
The inverters 370 , 380 , batteries 360 , transfer switch 400 , control panel 340 , heaters 320 , 245 , and pumps 330 , 265 are all connected to a fuse box (not shown). As would be clear to a person skilled in the art, the power system is interconnected with wires (not shown) in order for the electronic devices to communicate with each other.
As an alternative, an inverter could be used. For this alternative, two batteries would be connected in series to the inverter which would connect to a heater and pump set. As an example two batteries and a larger inverter would connect to heater 320 and pump 330 . Similarly, two batteries and an inverter would connect to heater 245 and pump 265 .
A float and alarm system may also be used with the main water tank 140 to ensure that the water level in the main water tank does not drop below a certain level.
Alternatives and variants to the system described above are, of course, possible. In one variant, a blower or heater may be used either as a substitute or in conjunction with the snow tank heating subsystem. Another variant may use a tankless water heater system in place of installing a main water tank heating system for the main water tank 140 . A further variant may use an extra water tank in the event evaporation or water loss causes the main water tank 140 to have insufficient water to resurface the ice rink.
The system described above can be operated according to one aspect of the invention. As the ice resurfacing machine 100 moves in forward direction along the ice surface, the blade 180 shaves a thin slice off the ice surface. This thin slice is then collected by a series of coupled horizontal augers 190 and vertical augers 200 . The ice and snow shavings 210 are then deposited at the snow dump tank receptacle 110 . Inside the snow dump tank 110 , the collected ice and snow shavings are melted by the snow tank heating subsystem. The water resulting from the melted ice and snow shavings then flows through the filtering subsystem 130 where the water is filtered. After filtering, the filtered water flows into the main water tank 140 . Inside the main water tank 140 , the water is heated to an industry standard by the main water tank heating subsystem 150 . The heated water from within the main water tank 140 is directed to the conditioner 170 through the existing water distribution system. The heated and purified water is then poured on to the ice surface and spread evenly across the conditioner width by a towel 20 to leave a smooth clean ice surface.
One aspect of the invention provides a kit of parts for retrofitting an existing ice resurfacing machine so that snow and ice shavings from an ice rink can be recycled for further ice resurfacing. The kit of parts may include the heating subsystems 120 / 150 , the insulation for the snow dump tank 110 , the filter subsystem 130 , and the power system 160 .
It should be noted that another aspect of the invention involves the maintenance and servicing of retrofitted ice resurfacing machines. Once an ice resurfacing machine has been retrofitted to recycle ice shavings, on-going maintenance and service may be provided to the operator of the retrofitted ice resurfacing machine. The maintenance and service may include providing a qualified maintenance worker to inspect the various components which were installed on the ice resurfacing machine. Specifically, the maintenance worker would check and clean the heated metal grate 230 in the snow dump tank 110 , and replace the filter 270 in the filtering subsystem 130 . The maintenance and service would also include draining and replacing the heating oil used in the heating pipes 310 , 240 . Finally, the maintenance and service would include the replacement of any component which may be defective or which may not be working properly. The entity providing the maintenance and upkeep service to the ice resurfacing machine may do so under a suitable contract. The sale of a retrofit kit, installation of the retrofit kit to the ice resurfacing machine, and the service and maintenance of the retrofitted machine may all be provided under a single contract and price point.
As an extra service to the operators of the converted ice resurfacing machines, the water derived from the ice and snow scraped from the ice rink can also be disposed of in a safe manner. The water from the melted ice may be tainted with contaminants such as those from the paint used to color the ice surface, the logos on the surface, as well as the lines on the ice. While the ice scraped from the ice surface can be recycled, disposing of the waste water is not as simple as dumping the ice and the contaminated water outside the arena. The safe and proper disposal of this material can be provided as a further service to the operators of the converted ice resurfacing machines. The safe disposal may, of course, take different forms as the disposal should conform to the standards and rules in the area where the ice resurfacing machines are being used.
In one embodiment, the disposal of the contaminated water may involve pumping the contaminated water resulting from the scraped ice from the ice resurfacing machine's main water tank into a qualified disposal tank. Any remaining contaminated water is then cleaned from the main water tank. The contaminated water is then disposed of in accordance with existing relevant government regulations. This final step may involve transporting the contaminated water to an environmental hazard waste depot and disposing of the contaminated water at the facility.
A person understanding this invention may now conceive of alternative structures and embodiments or variations of the above all of which are intended to fall within the scope of the invention as defined in the claims that follow. | Systems, methods and devices for converting existing ice resurfacers to reuse collected ice and snow for further ice resurfacing. The systems, methods and devices allows for efficient, clean and environmental friendly ice resurfacing. The conversion includes the modification and/or replacement of the snow dump tank, main water tank and the installing of heating and power systems. This invention is designed for present machines and for incorporation into future manufacturing of ice resurfacers. While reducing the requirement for large amounts of fresh water, the surface water being pre-heated by two commercial hot water tanks, it also reduces the amount of labor and costs associated with ice resurfacing. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a ventilator and an improved ventilating method.
It is common for patients in the intensive care unit to be connected to mechanical ventilators to provide partial or complete assistance in breathing.
Weaning patients from ventilatory support is one of the major challenges involved in their case. The weaning process involves the application of an appropriate level of partial ventilatory support coupled with an ongoing assessment of the patient's status, so that the support level may be adjusted as necessary. For effective implementation this process requires that the mechanical properties of the patient's respiratory system be monitored regularly. With this information the magnitude of the muscular breathing efforts applied by the patient can be determined, and any adverse changes in the mechanical properties of the lungs can be determined.
The mechanical properties of the lungs are crucial determinants of their ability to function properly. Despite this, the assessment of respiratory mechanical function in mechanically ventilated patients in the intensive care unit is currently rudimentary, being limited for the most part to consideration of peak airway pressures and to visual inspection of flow-volume loops.
Many mechanical ventilators are available commercially. However, none is able to deliver both conventional ventilation flow waveforms and high frequency ventilation simultaneously. Also, although most modern ventilators have a variety of available flow waveforms they can deliver during inspiration, these are all pre-programmed and represent those considered the most important at the time of manufacture. No commercially available ventilator can deliver an arbitrary inspiratory flow waveform (within its band-width capabilities) with high precision.
Although some ventilators have the capability to estimate simple parameters of patient respiratory mechanics, there is a need for greater accuracy of signal measurement and greater sophistication in the analysis methods used.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a mechanical ventilator for human use which can be used both as a means of life-support in cases where the patient's respiratory musculature is unable to adequately ventilate the lungs, and as a means of applying broad-band oscillations in flow to the lungs for the purposes of identifying pulmonary mechanical parameters.
In accordance with one particular embodiment of the invention there is provided a mechanical ventilator comprising a hollow chamber having an interior wall,
an air displacement member mounted for oscillating movement in said chamber, said air displacement member having first and second opposed air displacing faces, and a free outer surface between said faces,
motor means to oscillate said displacement member in said chamber such that said free outer surface of said displacement member is maintained in closely spaced apart relationship with said interior wall throughout said oscillating movement,
first and second variable zones defined in said chamber, said first zone being defined between said first face and said interior wall and said second zone being defined between said second face and said interior wall, and
an air outlet and an air inlet in said first variable zone and an air flow port in said second variable zone for flow of air in and out of said second zone, and
said closely spaced apart relationship being selected such that resistance to air flow between said free outer surface and said interior wall is greater than mechanical impedance of a patient receiving air discharged from said air outlet.
In accordance with another particular embodiment of the invention there is provided a mechanical ventilator comprising a hollow chamber having a semi-cylindrical interior wall, an air displacement vane mounted for oscillating radial motion in said chamber, said vane having a free outer edge surface in closely spaced apart relationship with said interior wall, said relationship being maintained throughout said oscillating radial motion,
said oscillating motion having an air discharge mode and an air intake mode, an outlet for discharge of air from said chamber during said air discharge mode, and an air inlet for intake of air into said chamber during said air intake mode,
said closely spaced apart relationship being selected such that the resistance to air flow between said free outer edge surface and said interior wall is greater than mechanical impedance of a patient receiving air discharged from said air outlet.
In accordance with still another embodiment of the invention there is provided in a method of ventilating a patient in which air is discharged from a ventilating chamber by oscillating motion of an air displacement member, the improvement wherein chamber parameters comprising the volume of air discharged from the chamber and air pressures within the chamber are monitored and pulmonary mechanical properties of the patient are assessed from said parameters.
In accordance with yet another embodiment of the invention there is provided a method of ventilating a patient comprising providing a hollow chamber having a semi-cylindrical interior wall,
oscillating an air displacement vane in said chamber about an axis of rotation such that a free outer edge surface of said vane is maintained in closely spaced apart relationship with said interior wall throughout said oscillating,
each oscillation cycle having sequentially an air discharge phase and an air intake phase, and
discharging ventilating air to said patient in each air discharge phase.
DESCRIPTION OF PREFERRED EMBODIMENTS
The ventilator of the invention preferably includes valve means associated with said air outlet and air inlet, and control means adapted to maintain said air outlet open and said air inlet closed during an air discharge mode, and said air outlet closed and said air inlet open during an air intake mode.
The ventilator also preferably includes means to determine flow of air through the air flow port.
In an especially preferred embodiment the ventilator includes means for determining respiratory mechanical function from parameters of the chamber, said parameters comprising volume of air discharged from said first zone, air pressure in said first zone, pressure-flow characteristics of a conduit from said air outlet to the patient, and air pressure in the second zone or flow of air through the air flow port in the second zone.
The motor means which drives the air displacement member or vane suitably includes a control means for varying the frequency of the oscillating motion and the displacement of the air displacement member, the angular displacement in the case of the vane, during the oscillating motion.
Variation of the parameters of the oscillating motion alters the chamber parameters. Variation of the chamber parameters provokes response from the patient which permits assessment of lung function.
Thus the ventilator has a high band-width capability; that is, it can deliver flow waveforms to the lung with frequencies up to 10 Hz or more as well as being able to deliver conventional waveforms at normal breathing frequencies. Also, the ventilator is completely flexible in the waveforms that it can deliver, due to its being entirely under computer control.
Finally, the ventilator is designed so that the mechanical impedance of the load being ventilated (i.e. the patient) is identified continuously without the need for additional measuring equipment having to be installed in the ventilator circuit.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates schematically a ventilator of the invention in a preferred embodiment.
DESCRIPTION WITH REFERENCE TO DRAWINGS
The basic design of the ventilator is shown in FIG. 1. It consists of a half-cylindrical housing (inside radius r, length l) enclosed at both ends and on the bottom by flat plates. Pivoting inside the housing along an axis at its centre of curvature is a vane. The rod about which the vane pivots passes through the two housing endplates via sealed bearings.
The vane is machined to have dimensions r-d and l-d, where d is a very small quantity (small fraction of a mm). The dimensions r and 1, on the other hand have dimensions such that the vane is able to displace a liter or more of gas as it rotates throughout its allowable range. In other words, the vane has essentially the same dimensions as the inside of the housing except that it does not actually touch the walls of the housing as it rotates. The vane is driven by an electric torque motor with power sufficient to oscillate the vane. By way of example the vane may oscillate at frequencies up to 10 Hz and displacements at 10 Hz of up to 20 ml.
The floor of the housing to the right of the vane contains two valves, labelled in FIG. 1 as A and B. Valve A connects the housing directly to the patient via a relatively short segment of flexible but non compliant tubing. Thus, when A is open and B is closed, gas is forced into the patient's lungs as the vane sweeps in a clockwise direction (as seen from FIG. 1). Conversely, when A is closed and B is open, fresh air is drawn into the housing as the vane sweeps in a counter clockwise direction. At the same time, a third valve (labelled C in FIG. 1) allows the patient to exhale directly to atmosphere through a conventional pneumotachograph.
In the floor of the housing to the left of the vane is another hole which connects to atmosphere through a conventional pneumotachograph. A differential pressure transducer connected across the two ports of the pneumotachograph measures gas flow as it enters and leaves the housing from the left side of the vane.
This design allows the patient to be ventilated effectively, provided the dimensions of the housing are chosen correctly, the motor has sufficient power to overcome the inertia of the vane and the mechanical impedance of the patient, and the clearance between the vane and housing is sufficiently small that most of the vane displacement results in gas moving into the patient rather than flowing back past the vane. This latter requirement, broadly speaking, means that the resistance to gas flow of the space between the vane and the housing must be large compared to that of the patient.
This design also, however, allows one to estimate the mechanical load being ventilated. The angular displacement of the vane is accurately measured, and can be converted into volume displacement of the vane (V) from the geometry of the system (the housing and vane are constructed of essentially perfectly rigid materials). This volume displacement has three components: volume displaced into the patient (Vpat), compressed volume in the housing (Vcomp), and volume loss due to back flow past the vane (Vback). Vcomp is obtained from the pressure measured inside the right housing and the volume of gas in it (again obtained from the angular position of the vane). Vback is obtained from the difference in the volume displacement of the vane and the integrated flow measured entering the left housing.
Vpat=V-Vcomp-Vback
The pressure required to drive Vpat into the patient through the ventilator tubing is the pressure (P) inside the right housing. From the pressure-flow characteristics of the ventilator tubing the pressure at the patient from P and the flow through the tubing (dvpat/dt) can be determined.
The key points of difference between the ventilator of the invention and existing ventilators are:
1) The ventilator is completely flexible. Any volume perturbation can be applied to the lungs; it is merely a matter of creating the waveform in software. No other device exists for such a purpose.
2) The ventilator provides measurements of patient respiratory mechanics without requiring the direct measurement of flow into the lungs, and requires no extra measuring equipment to be installed in the ventilation line. Furthermore, the ventilator will be able to assess patient mechanics more accurately than existing devices, and will be able to apply more sophisticated analysis methods.
3) The ventilator combines both conventional mechanical ventilation (for life support) and flexible volume oscillation capabilities (for respiratory mechanics testing) in a single device. No other device does this.
4) The ventilator in a particular embodiment is based on a novel rotating vane design that is compact and allows precision control of flow to the patient.
Thus the ventilator of the invention allows measurement of respiratory mechanics in patients, especially ICU patients. In a specific embodiment the ventilator is based around a vane that rotates inside a semi-circular housing. The vane is machined to have a finite but tiny clearance from the housing as it rotates through its allowable range, displacing up to 1.8 liters of gas into the patient. The vane is driven under full computer control by an electric torque motor capable of oscillating it throughout its range of movement at normal breathing frequencies, and of generating displacements at 10 Hz of up to 20 ml. This design allows the patient to be ventilated using conventional ventilator waveform. It also permits the estimation of the mechanical load being ventilated from measurements of the angular displacement of the vane and the pressures within the housing either side of the vane, obviating the need for direct measurement of flow. The new ventilator may serve as a flexible research tool for mechanics studies in ICU patients, and ultimately as a device for routine assessment of respiratory mechanical status.
The ventilator can be used in a hospital intensive care unit, and has application for patients being mechanically ventilated during surgery. | A mechanical ventilator for ventilating a patient employs an air displacement member mounted for oscillating motion in a chamber; preferably the chamber is semi-cylindrical and the air displacement member is a vane mounted for oscillating movement about an axis of rotation such that a free outer edge surface of the vane is maintained in closely spaced apart relationship with the interior wall of the chamber throughout the oscillating; the ventilator permits significant variation in the ventilation flow waveform. | 0 |
[0001] This invention relates to a folding table, portable, in particular a massage table.
TECHNICAL OVERVIEW
[0002] Folding tables are known in which the plate is made of two elements folding over each other and with retractable legs (U.S. 2006/260516). We also know of folding tables in which the plate is comprising one element with retractable legs folding in two parts but requiring time and many manipulations to set up, not allowing a construction sufficiently strong and light, for example, for a portable massage table. Finally we know of folding tables whose plate comprises more than two elements (WO 2007/065919), but their general structure does not allow to make a portable massage tables, light, robust and manageable. In the particular field of portable massage tables, so far, one knows of folding tables with two halves which, when folded, have a large volume, making them bulky and difficult to transport. None of these tables were until now sufficiently compact, robust, lightweight and easy to use.
[0003] This invention proposes a folding table, which is at the same time easy to use, compact, lightweight and very robust.
[0004] To this end, the folding table according to the invention is characterized in that it comprises an elongated plate consisting of at least four elements mounted on rigid frames articulated together perpendicularly to the long side of the plate, means for locking the table in the open position, said plate being connected with legs, each leg being formed of at least two parts articulated together, the first parts being mounted with articulations on a part fixed to the end elements, the length of each part being less than the length of said plate elements; braces, comprising two arms articulated together by a hinge, are articulated to the second part of each leg at each inner end of the end parts of the plate, locking means are used between the braces of each end element and/or the legs of each end element to prevent lateral movement of the table; there are tension cables, linking articulations between the arms of the braces to the point situated above the articulation of the legs on the parts attached to the frame of the end elements, and means for locking the articulation between the parts of the legs to hold the legs in the open position and to make the whole rigid, the whole being designed in such a way that the legs and the articulated arms of each half of the table, once folded, fold into the frames of the adjacent elements, and that all the elements when folded, are superimposed.
[0005] Thus we obtain a table whose size when folded is reduced, for example for a massage table, whose installation is quick and easy, and also ensures high strength and stability, supporting high workloads with a very light construction.
[0006] According to one embodiment, the table is characterized in that it comprises an elongated plate made of at least four elements mounted on rigid frames articulated together perpendicularly to the long sides of the plate means for locking the table in the open position, said plate having legs, each leg being made of at least two parts articulated together, the first parts being articulated on a part attached to the end elements, the length of each part being less than the length of said elements of the plate, bracing, comprising two arms articulated together are articulated to the second section of each leg and to each inner end of the end elements of the plate, locking means are used between the braces of each end element and/or the legs of each end element to prevent lateral movement of the table, and there are tension cables connecting the articulations between the arms of the braces to the point located above the articulations of the legs on the parts attached to the frame of the end elements and tension cables connecting the legs, at a point above the articulation between the leg to the arm, to the articulations of the bracing with the inner ends of the end parts of the plate to hold the legs in the open position and make the whole rigid, the whole being designed in such a way that the legs and the articulated braces of each half of the table, once folded, fold into the frames of the adjacent elements and that all the elements, once folded, are superimposed.
[0007] According to one embodiment, the table is characterized in that in the folded position, the walls of the frames ( 2 a ) covers at least approximately completely the said parts of the legs and said folded braces.
[0008] According to one embodiment, the table is characterized in that each leg comprises a third part sliding on the second part and there are means to fix the two parts together in a desired position for adjusting the height of the table.
[0009] According to one embodiment, the table is characterized in that the two end elements of the plate are of a smaller width than the central elements of the plate in a way that in the folded state the lateral parts of the end elements of the plate are covered at least approximately by the parts of the frames of the central elements of the plate.
[0010] According to one embodiment, the table is characterized in that supporting means of the central elements comprise surface elements on the adjacent parts of the frames between the end elements and the central elements such that the vertical pressure exerted on the central elements is transmitted to the end elements and there are similar supporting means between the central elements.
[0011] According to one embodiment, the table is characterized in that the side parts of the frames of the central elements of the plate are articulated at a point and form, in the open state of the table, a rigid assembly maintaining the central elements of the plate aligned with each other when applying a force F 1 on the table.
[0012] According to one embodiment, the table is characterized in that means for locking the table in the open position comprise tension cables fixed on one side to the articulations between the two articulated arms of the braces and on the other side to the articulation of the braces with the end elements of the opposite side of the table, or tension cables respectively fixed between the articulations of the braces of the end elements and between the articulations between the two articulated arms of the braces of the end elements, said cables being fixed together by a part.
[0013] According to one embodiment, the table is characterized in that means for locking the table in the open position comprise tension cables attached between the articulations located between the two articulated arms of the braces and a point of the adjacent elements respectively.
[0014] According to one embodiment, the table is characterized in that means for locking the table in the open position comprise tension cables fixed firstly to the articulations between the two articulated arms of the braces with the end elements of the opposite side of the table and fixed together to their intersection by a part, the part passing through an orifice of a central part fixed and articulated to a part attached to the adjacent parts of the central elements, or tension cables respectively fixed between the articulations of the braces with the end elements and between the articulations located between the two articulated arms of the braces of the end elements, said cables being fixed together by a part, the part passing through the orifice of the central part.
[0015] According to one embodiment, the table is characterized in that means for locking the table in the open position comprise tension cables fixed on one side to the articulations between the two articulated arms of the braces and on the other side to the articulations of the braces with the end elements of the opposite side of the table, the cables passing through an orifice of a central part fixed and articulated to a part attached to the adjacent parts of the central elements, or tension cables fixed respectively between the articulations of the braces with the end elements and between the articulations between the two articulated arms of the braces of the end elements, said cables being secured together by a part, the part passing through the orifice of the central part and a cable fixed between the articulations of the braces with the end elements and passing through an orifice situated on the central part.
[0016] According to one embodiment, the table is characterized in that the attachment point of the tension cables and to the articulations of the braces to the end elements is removed to the point located above the articulations of the legs on a part of the frames of the end elements said cables passing through a fixed point of the articulation of the braces with the end elements.
DESCRIPTION
[0017] The invention will now be described in detail with the following description that refer to the accompanying drawings in which:
[0018] FIG. 1 is an elevation view of one embodiment of the table in the unfolded state.
[0019] FIG. 2 shows a view of the table in an intermediate folding state.
[0020] FIG. 3 is a bottom view of an end element of the plate with the legs folded inside.
[0021] FIG. 4 shows the folding step in which the two end elements are folded over the median elements.
[0022] FIG. 5 is an elevation view of the table when closed.
[0023] FIG. 1 b is an elevation view of the table according to a first embodiment.
[0024] FIG. 6 is an elevation view of the table in the unfolded position of a second embodiment.
[0025] FIG. 7 is an elevation view of the table shown in the intermediate position of folding according to the second embodiment.
[0026] FIG. 8 is an elevation view of the table in the unfolded position in a third embodiment.
[0027] FIG. 9 is an elevation view of the table shown in the intermediate position of folding according to the third embodiment.
[0028] FIG. 10 shows the stage of folding according to the second and third alternative embodiments in which the two end elements are folded over the median elements.
[0029] FIG. 11 is an elevation view of the table closed according to the second and the third embodiments.
[0030] FIG. 12 shows a detail of the table illustrating one way to secure the four elements of the plate between them.
[0031] According to the first embodiment illustrated in FIGS. 1 to 5 , the massage table consists of a rectangular plate 1 made of four elements approximately of the same length, 1 a, 1 b, 1 c, 1 d, the four elements being articulated to each other with articulations 14 , 20 c, the axis of which is perpendicular to the long side of the plate 1 .
[0032] Each element consists of a rigid frame 2 a, covered by a plate 2 b, its self covered with foam 2 c and upholstered. The two central elements 1 b, 1 c can be substantially wider than the end elements 1 a, 1 d. The parts 20 a, 20 b of the frames of the elements 1 b, 1 c are wider than the other parts of the frame so that the elements 1 a, 1 d can fold inside the elements 1 b, respectively 1 c, without projecting beyond these frames at these places ( FIG. 4 ), they allow to maintain the central elements 1 b, 1 c aligned, these elements are substantially wider than the end elements 1 a, 1 d as shown in FIGS. 1 , 2 , 5 and 11 in order to fold the table.
[0033] Adjacent parts of the frames 2 a of the central elements 1 b, 1 c can be wider in order to increase the resistance of the centre of the table. In this case the central elements 1 b, 1 c are slightly longer than the end elements 1 a, 1 d in order to fold the table.
[0034] At the four corners of the plate 1 are mounted the legs 3 each consisting of three parts. The first part 3 a is articulated at the point b by an articulation on a part B fixed to the free end 2 a of the frames of the end elements 1 a, 1 d. This first part 3 a is extended by a second part 3 b. This second part, connected to the first by an articulation 6 articulated at 6 c has longitudinal ribs. The third lower part 3 c of the leg has ribs corresponding to the ribs of the second part 3 b and can slide thereon without lateral play, making it possible to adjust the height of the table. There are a series of holes 3 x evenly distributed over the third part 3 c which can coincide with a single opening of the second part 3 b, fixation between the two parts can be made, for example, with a screw 30 passing through the two holes and a wing-nut, or similar, tightening the whole.
[0035] Alternatively, if one renounces to the height adjustment, legs can comprise only two parts articulated together.
[0036] On each side of the table there are two articulated braces, each one comprising several articulated arms, in the example shown there are two arms 7 , 8 articulated in 30 , 31 , 32 connecting the inner part 2 a in 32 of the end element 1 a, respectively 1 d to the second part 3 b of the corresponding leg 3 . There is also a mean, such as a part 9 connecting the articulated arms 7 and a part 10 connecting the articulated arms 8 associated with the element 1 a, respectively 1 d, making the whole rigid and preventing lateral movement of the table in its open position.
[0037] The stability of the table in the open position is ensured by a system of cables C 1 , C 2 , C 3 , exerting reverse tensions to the load distributed on the table on the different parts of the structure. A cable C 1 is attached between the point b 1 located above the leg 3 on a part B fixed to the frame 2 a, and the articulation 31 between the articulated arms 7 and 8 of the braces. A cable C 3 connects this same articulation 31 to the articulation 32 of the opposite end element. Finally, to lock the articulation between the two parts 3 a, 3 b of the legs 3 a cable C 2 connects the leg 3 at a point situated above the point 30 of articulation of the leg 3 to the brace 7 , 8 , to the articulation 32 of the same end element 1 a, respectively 1 d. The cable C 2 can be replaced by a hinge or self-locking hinge or a system to maintain aligned the two parts 3 a, 3 b of the legs 3 . To improve the locking in the open position of the articulation 6 the cable C 2 can be attached to a point 6 b of the first part 3 a of the leg 3 and slide on a part 6 a of the second part 6 b of the foot 3 , and so exert a force F 2 on the articulation 6 . The elements 6 a and 6 b being offset from the articulation point 6 c of the articulation 6 the force F 2 will have the effect of holding the elements 3 a and 3 b aligned.
[0038] The same cable system is planned for the other legs. The lengths of these cables are adjusted so that they are tensioned in the open position of the table.
[0039] The end elements 1 a, 1 d of the plate 1 are kept aligned to their adjacent elements 1 b, 1 c by the two sets of triangulation made by the cables C 1 and C 3 : b 1 , 31 , 32 on one hand and 32 , 31 , 32 on the other hand. The two central elements 1 b, 1 c of the plate 1 are kept aligned together by the parts 20 a and 20 b of their frames, articulated in 20 c. The same device is provided for the opposite sides of the frames ( FIG. 1 ). Thus the weight of the patient on the table will result to tension the cables C 3 and C 1 which will exert a force opposite to the weight on the arm 8 , involving triangulation b 1 , 31 , 32 , 32 , 31 , 32 .
[0040] In the open position of the table, to stabilize the position of the legs, it suffices to exert a pressure on the articulation 31 in the direction of the arrow F 3 , the braces 7 and 8 forming between them an obtuse angle. This pressure in 31 will cause tension to the cables C 1 and C 2 by the triangular forces and thus maintain aligned the elements 3 a and 3 b of the legs 3 perpendicular to the plate to make the whole rigid. To close the table, a pressure is exerted on the articulation 31 in the opposite direction of the arrow F 3 , which will release the cable tension C 1 and C 2 . Once the cables are not under tension anymore, the articulated braces 7 and 8 can be folded in the frame of the element 1 a, respectively 1 d, as illustrated in FIGS. 2 and 3 . Once the legs are retracted into the elements 1 a and 1 d, the elements 1 a, respectively 1 c can rotate a 180° on the articulations 14 . Then the two pairs of elements rotate 90° on the articulation 20 c ( FIGS. 4 and 5 ). In this position the four elements 1 a, 1 b, 1 c and 1 d are superimposed on each other and the side walls of the frames 2 a cover at least approximately completely the legs and braces folded, forming a compact structure not too bulky.
[0041] Since the end elements 1 a and 1 d are bearing the central elements 1 b and 1 c, in order to relieve the pressure on the articulation 14 , there are additional blocking means Z, for example mortise or tenon, to secure in the open position the central elements 1 b, 1 c, with bearing end elements 1 a, 1 d, as shown in FIGS. 11 and 12 . The same locking means may also be used between the central elements 1 b, 1 c for rigidifying the central part of the table and also to allow the second and third embodiments.
[0042] As shown in FIG. 1 , parts 2 a of the frames, at both ends of the table, may be wider on a portion of their length and have orifices 13 allowing for example the use of a face cradle.
[0043] A part S with a handle P can be fixed between the adjacent parts of the frames 1 b and 1 c ( FIG. 5 ).
[0044] According to a first alternative embodiment shown in FIG. 1 b a cable C 3 replacing the cable C 30 can be attached between the articulation 31 of the arms of the braces and a point 40 of the Central elements 1 b, 1 c.
[0045] According to a second embodiment ( FIGS. 6 and 7 ) the cables C 4 and C 5 can replace the cables C 3 , the four elements ( 1 a, 1 b, 1 c, 1 d ) are all of the same width or approximately the same width and the parts 20 a and 20 b of the central elements are eliminated. Elements 0 of adjacent parts of the central elements 1 b, 1 c make the frames broader in some places and are connected by hinges 14 in order to replace the articulation 20 c. Parts M are fixed in N and articulated in n 1 on the adjacent inner parts of the central frames 1 b, 1 c and fold into the table, in the open position of the table part M can pivot on its frame to reach the centre of the table at the junction of the cables C 4 and C 5 or remain upright, which implicates to slightly remove the junction point of the cables C 4 and C 5 . The cable C 4 is attached to the articulation 32 of the end elements 1 a to 1 d, the cable C 5 is attached to the articulation 31 of the end elements 1 a to 1 d, these two cables pass through the orifice m 1 in parts M, they are fastened together by a part X 1 , there are means for locking the part M so that it can not go beyond the point X 1 when it unfolds: for example, the part X 1 is equipped with a larger part that can not pass through the orifice m 1 , or the orifice m 1 is smaller at one of its ends in order that the part X 1 , used to fixe the cables C 5 and C 4 , can not cross it entirely. So the central elements 1 b and 1 c of the frame are kept aligned by the cable C 4 exerting a force on the part M, vertical and opposite to the load located on the table and the end elements 1 a, 1 d are kept aligned by the cables C 5 and C 1 exerting a pressure on the brace 8 vertical and opposite to the charge located on the table. As illustrated in FIG. 7 , the cables C 4 and C 5 can slide in m 1 to let the part M fold into the table. There are also locking means Z in order to distribute the vertical load on the central adjacent elements 1 a, 1 c. If the cables C 3 are not replaced by the cables C 4 and C 5 , they are fixed at their intersection, or near their intersection, by a part X 1 passing through the orifice ml and will have the same function as the cables C 4 and C 5 , C 4 or C 3 cables can be fixed to the top of the legs at points b 1 and pass through a loop or a similar item attached to the articulation points 32 of the elements 1 a and 1 d.
[0046] In a third alternative embodiment ( FIG. 8 ) cables C 3 are kept, they pass through an orifice m 1 of the part M that can be longer and have a second orifice m 2 . A cable C 6 attached to the articulation 32 of the elements 1 a to 1 d passes through the point m 1 , or to relieve the cable, through the point m 2 . C 6 cable can also be attached in b 1 and pass through the articulation 32 or a part attached to the articulation 32 . Cable C 6 has the effect of maintaining the central elements 1 b and 1 c aligned. If the part M is fixed to the element 1 c, the cable C 3 , attached to the articulation 31 of the bracing of the element 1 a, may be fixed in m 1 , if the part M is fixed to the element 1 b the cable C 3 attached to the articulation 31 of the element 1 d will be fixed in m 1 , this in order to unfold automatically the part M if it folds in the longitudinal direction of the table, and to fix it when unfolding the table, there is also the same locking means Z between the central elements 1 b, 1 c and also the same articulation system as in the second embodiment attached to the elements O of the adjacent parts of the central frames. In order to fold the part M in its frame, the cables C 3 remained free and C 6 slide through the openings m 1 and m 2 ( FIG. 9 ). The cables C 3 can be replaced by the cables C 4 and C 5 arranged in the same way as in the second embodiment, the cables C 4 can also be attached to the top of the legs at the points b 1 and go through a loop or similar part set at the articulations 32 of the elements 1 a and 1 d. | This invention relates to a folding table, portable, in particular a massage table, comprising a plate ( 1 ) made up of at least four elements ( 1 a, 1 b, 1 c, 1 d ) mounted on rigid articulated frames ( 2 a ), means for locking the table in the open position, said plate having legs ( 3 ) comprising at least two parts ( 3 a, 3 b ) articulated together, the first parts ( 3 a ) being articulated to the end elements ( 1 a, 1 d ), braces, comprising two arms ( 7, 8 ) articulated together, are articulated to the end elements ( 1 a, 1 d ), locking means ( 9, 10 ) are used between the arms ( 7, 8 ) and/or the legs ( 3 ). There are cables (C 1 ) for connecting the articulations ( 31 ) of said arms ( 7, 8 ) above (b 1 ) the articulations (b) of the legs ( 3 ) to the end elements ( 1 a, 1 d ), and means for locking the articulation ( 6 ) between the parts ( 3 a ) and ( 3 b ) of the legs to keep the legs erect and to make the whole rigid, the whole being designed in such a way that the articulated legs and arms of each half of the table, once folded, fold into the frames ( 2 a ). | 0 |
This application claims priority to U.S. Provisional Application Ser. No. 60/382,344, filed May 23, 2002, and is a continuation-in-part of U.S. application Ser. No. 10/150,088, filed May 20, 2002, the disclosure of which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a versatile contactless electronic transaction card which may provide a plurality of contactless functions on one card. The present invention also relates to a contactless card which may be convertible for use in operating environments having different size accommodations for the contactless card.
2. Brief Description of the Related Art
Electronic transaction cards have long been prevalent in modern society for storing user or account specific information to provide convenient and fast transactions in a variety of situations. For example, such cards may be used to store information regarding a user's account information to facilitate purchase transactions or service transactions, or a user's identity to gain access through secure or privileged networks and systems. Generally, there are two types of such electronic transaction cards—the more established contact-type cards and the more recent contactless transaction cards.
Examples of a contact-type electronic transaction card include the credit card, as shown in FIG. 1 , or the subscriber identity modules (SIM) card, as shown in FIG. 2 . While credit cards are well known in this country, SIM cards are used primarily in Europe and Asia (although gaining in popularity in the United States) in communication devices such as mobile telephones to enable a user to access an individual account or a particular wireless communication network in a specific country. Generally SIM cards are provided in one of two sizes, i.e., a full-sized card which is sized similarly to a credit card, and a micro or plug-in sized card (see FIG. 2 ) which is much smaller than a credit card (approximately 25 mm long and 15 mm wide). In the contact-type cards, the account and/or other user-specific information is stored or encoded on a magnetic strip or an integrated circuit (IC) chip embedded in the card. The information stored or associated with the card can only be accessed by placing the magnetic strip or IC chip in direct physical contact with a card reader or access device.
Contactless transaction cards, on the other hand, are presently commonly used in public transportation systems or for security/access control. Similarly to a contact-type card, the integrated circuit in a contactless transaction card may store information specific to a user such as a user's account information or identification information. On the other hand, while a contact-type card requires physical contact of the magnetic strip or IC with the card reader or access device, a contactless transaction card transmits and receives information from and to a card reader or access device via radiofrequency signals and does not require physical contact between the card and the reader or access device.
As shown in FIG. 3 , a contactless transaction card 200 includes an integrated circuit 210 mounted on a card substrate 230 and an antenna 220 extending from the IC 210 , wherein the antenna 220 is also mounted on card substrate 230 . Preferably, both the IC 210 and the antenna 220 are embedded inside a plurality of layers laminated together to form the card 200 . The antenna 220 has a relatively long total length with respect to the IC 210 , and is typically incorporated in the card 200 in a looped manner or wound in a pattern within the plane of the card. The transfer or reading of information to or from a contactless transaction card is achieved by the transmission of RF signals through the antenna 220 extending from the integrated circuit 210 . The length of the antenna is proportional to the transmission and reception range thereof, so that the longer the antenna, the greater the distance away from the reader/access device the card can be held to successfully transfer or access information between the card and the reader/access device.
In an example of using a contactless transaction card, a user is enabled to gain access to a secured location by simply bringing the contactless transaction card close to an access device within a range appropriate for the antenna, whereupon the access device is enabled to read the identification data contained in the IC via the antenna in the card. If the access device determines that the user, based on the detected identification information, is authorized to access the secured location, the access device sends a signal which controls the security system to enable the user to gain access to the secured location.
When a contactless transaction card is used in a transportation system, for example, the IC mounted in the card contains the user's account information, such as an available balance (for a declining balance type of arrangement), or billing information (for a credit type of arrangement). The manner of operation for using the card to enter or exit the transportation system or to access or update the user's account is similar to the operation for access control, in that the card is simply brought towards the card reader within the transmission range of the antenna.
Contactless transaction cards provide several advantages over the standard integrated circuit (contact-type) cards, such as faster transaction times, greater ease of use, and less wear and tear on the cards and the access devices. Hence, the popularity of contactless transaction cards is increasing as wireless technology becomes incorporated into a greater variety of applications.
One consequence of the increased use of contactless transaction cards is that a user may be required to carry several cards at one time, each card usable in a different environment and/or for different functions. It would thus be desirable to consolidate and/or provide versatility to a contactless transaction card to reduce the number of cards maintained by a user.
SUMMARY OF THE INVENTION
The present invention includes a contactless transaction card which includes first and second contactless integrated circuit (IC) chips and an antenna connected to both ICs for enabling contactless operation of the functions provided by each IC. The contactless transaction card is preferably fabricated by laminating together a plurality of layers to form a carrier substrate. The antenna and one of the IC chips is embedded within the layers of the carrier substrate so as to be permanently formed in the card, while the second IC chip is provided in the card in a region formed as a micro-sized card which is removable from the main portion of the carrier substrate.
The present invention also includes an adapter card having a holder for retaining a micro-sized contactless transaction card and containing an antenna arranged to connect with the micro-sized card. The adapter thus converts the micro-sized transaction card into a full-sized card and enables access to the information associated with the IC chip contained in the card.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a standard credit card corresponding to a first embodiment of a contact-type electronic transaction card as known in the art;
FIG. 2 shows a micro-sized SIM card corresponding to a second embodiment of a contact-type electronic transaction card as known in the art;
FIG. 3 shows a standard contactless transaction card as known in the art;
FIG. 4 illustrates a contactless transaction card in accordance with the present invention;
FIGS. 5A–5C illustrate the layers forming the contactless transaction card shown in FIG. 4 ;
FIG. 6 shows the micro-sized contactless transaction card of the present invention upon being separated from the card shown in FIG. 4 ;
FIG. 7 illustrates an adapter usable in connection with the micro-sized card shown in FIG. 6 in accordance with the present invention;
FIGS. 8A–8D illustrate the layers forming the adapter shown in FIG. 7 ;
FIG. 9 illustrates an alternative embodiment of a carrier for a micro-sized contactless card, formed as a cover for a mobile communication device;
FIG. 10 illustrates a first holder arrangement for the carrier shown in FIG. 9 ;
FIG. 11 is an exploded view of the carrier arrangement shown in FIG. 10 ; and
FIG. 12 illustrates an alternative holder arrangement for the carrier shown in FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
A full-sized contactless transaction card 100 according to the present invention is shown in FIG. 4 and includes a card substrate 102 having a first contactless integrated circuit (IC) chip 104 and an antenna 106 embedded therein, and a micro-sized card 108 formed in the substrate 102 with a second contactless IC chip 110 mounted in the micro-sized card 108 . As indicated in FIG. 4 , the first IC chip 104 and the antenna 106 are formed beneath the exterior surface of card substrate 102 . IC chip 108 , on the other hand, is accessible at the surface of micro-sized card 108 .
The micro-sized card 108 is formed in the card substrate 102 so as to be detachable therefrom. For example, a plurality of cuts 112 may be made through the thickness of the card substrate 102 to define the shape of the micro sized card 108 , leaving one or more uncut connection bridges 114 between the body of the micro-sized card 108 and the card substrate 102 . Alternatively, instead of forming cuts 112 around substantially the entire perimeter of the micro-sized card 108 , one or more sides of the micro-sized card may be detachably connected to the card substrate by a perforation through the card substrate (see FIGS. 5A–5C ).
Referring now to FIGS. 5A–5C , the card substrate is preferably formed as a laminate of at least three layers 202 a , 202 b , 202 c of a plastic or polymeric material, such as PVC. Top layer 202 a is shown in FIG. 5A and has a cut 212 a formed therethrough defining a substantial portion of the periphery of a micro-sized card 208 a . As shown in FIG. 5A , top layer 202 a does not include bridges between the body of micro-sized card 208 a and the main portion of top layer 202 a . In the example embodiment shown in FIG. 5A , however, one side of the micro-sized card 208 a is connected to the main portion of layer 202 a along a perforated line 218 a . IC chip 210 is provided in layer 202 a so that at least electrical contacts of the IC 210 are exposed at both the front and rear surfaces of layer 202 a.
The middle layer 202 b is shown in FIG. 5B and includes a micro-sized card 208 b defined therein by cuts 212 b . Similarly to layer 202 a , one side of micro-sized card 208 b is connected to the main portion of layer 202 b along a perforated line 218 b . Unlike layer 202 a , however, the cuts 212 b in layer 202 b are interrupted along the perimeter of the shape of micro-sized card 208 b to define bridges 214 between the body of micro-sized card 208 b and the main portion of layer 202 b.
Middle layer 202 b further includes an IC chip 204 mounted therein and an antenna 206 formed thereon. Antenna 206 typically (although not necessarily) has a total length several times the perimeter of card layer 202 b , and is therefore coiled or looped around the planar area of the layer 202 b . As antenna 206 is coiled around layer 202 b , it runs across and contacts IC chip 204 so as to enable information to be stored and accessed in IC chip 204 via RF transmission through the antenna 206 . Antenna 206 also includes end segments 216 extending from the coiled portion, over the bridges 214 and into the body of micro-sized card 208 b . Preferably, the bridges 214 are located along the peripheral shape of micro-sized card 208 b so that the end segments 216 of antenna 206 extend into the body of the micro-sized card 208 b at positions aligned with the appropriate contact points of IC chip 210 . Since the layers 202 a , 202 b 202 c will be stacked and laminated together, as described further below, the appropriate contact points of IC chip 210 contact the antenna end segments 216 at the rear surface of layer 202 a when the layers are assembled into the finished card as illustrated in FIG. 4 .
For each contactless chip, the antenna loop(s) are connected to the chip at a positive region thereof and also at a negative region of the chip, so that the electromagnetic signals flow in to the respective chip at one side thereof, and out from the chip at another side thereof The middle portion of each chip is ground.
Antenna 206 may be formed on the layer 202 b in several ways. For example, antenna 206 can be simply provided as a length of a filament or wire affixed to the surface of layer 202 b . Alternatively, antenna 206 may be formed as a continuous line of a conductive ink, which may be deposited on the layer 202 b by printing.
As shown in FIG. 5C , bottom layer 202 c of the card substrate is formed similarly to top layer 202 a shown in FIG. 5A , except that the cut-out shape of micro-sized card 208 c does not include a mounted IC chip. In particular, the cut 212 c substantially defining the periphery of micro-sized card 208 c does not include bridges. Thus, only the middle layer 202 b includes bridges 214 between the micro-sized card 208 b and the main portion of the card layer 202 b.
After forming the layers 202 a , 202 b and 202 c as described above, the layers are aligned over each other and laminated together to form the contactless transaction card as shown in FIG. 4 , with antenna 206 and IC chip 204 permanently integrated within the card substrate. In the final form of the contactless transaction card, the antenna 206 is in permanent contact with the contactless IC chip 204 to enable contactless operation of the function provided therein, similarly to a standard full-sized contactless card. Additionally, operation of another contactless function is enabled via the contactless IC chip 210 by the antenna ends 216 extending between or within the layers forming the micro-sized card to connect with the contactless IC chip 210 while the micro-sized card is retained as part of the full-sized card. Thus, the two contactless chips 204 and 210 share the antenna 206 for transmitting and receiving information to and from the respective IC chips, resulting in one contactless card being usable for more than one type of contactless transaction.
Preferably, the micro-sized card is connected to the main portion of the card along only one perforated edge formed through all of the layers 202 a , 202 b , 202 c , and only the middle layer 202 b includes the bridges 214 to provide a surface for the antenna to be connected to the IC chip 210 of the micro-sized card. The ease with which the micro-sized card can be detached from the larger contactless card is maximized by providing the perforated edge between the micro-sized card and the main portion of the card substrate and by reducing the thickness of the bridges by forming the bridges in only one of the plurality of layers of the card.
Although the construction of the contactless card has been described above with respect to a specific embodiment, in practice the invention encompasses alternative embodiments, including contactless cards having more than two IC chips embedded, contactless cards formed having more layers than that shown and discussed with reference to FIGS. 5A–5C , inter alia.
Upon removing the micro sized card 108 from the card substrate 102 , as seen in FIG. 6 , the micro sized card must then be connected with another antenna to restore contactless operation of the contactless chip 110 . For example, the micro sized card 108 may be inserted into an adapter card 300 , such as that shown in FIG. 7 , which includes a substrate 302 , an embedded antenna 304 , and a pocket 306 for holding a micro-sized card 108 .
Like the carrier substrate shown in FIGS. 5A–5C , the adapter card 300 may be formed of a plurality of layers laminated together. Preferably, the layers are each made of a plastic or polymeric film, although it is not necessary that each layer be made of the same material.
As shown in FIG. 8A , the top layer 302 a is formed with a cutout region 308 sized and shaped corresponding to about half the micro-sized card 108 . Layer 302 a preferably has a thickness which is sufficiently pliable to enable a micro-sized card to be slipped through the cutout region 308 and underneath the pocket 306 .
The second layer 302 b is shown in FIG. 8B and includes a cutout 310 the size and shape of the micro-sized card 108 . Preferably, the second layer 302 b has a thickness greater than that of the top layer 302 a and is approximately equal to or slightly less than the thickness of the micro-sized card 108 .
A third layer 302 c as shown in FIG. 8C includes an antenna 304 formed thereon in a manner similar to that provided on middle layer 202 b of the contactless card as shown in FIG. 5B . End segments 312 of the antenna 304 extend into an alignment indicator 314 formed on the surface of layer 302 c , so that upon assembly of the layers, the antenna ends 312 are affixed to the layer 302 c in the alignment indicator 314 region at a location corresponding to where the IC chip of contactless card 108 is positioned when the card is properly inserted into the adapter.
Alternatively, the antenna may be formed between the top layer 302 a and the second layer 302 b , with the end segments 312 affixed to the third layer 302 c in the region of the indicator 314 upon assembly of the adapter. Optionally, a fourth layer 302 d may be provided as the bottom layer of the adapter 300 . The bottom layer is solid, with no shapes, holes or cutouts formed therein. Other alternatives are also envisioned within the scope of the present invention, including adapter cards formed with additional or different layers, and carrier cards with different structures for forming the contactless card holder.
To use the adapter 300 , the micro-sized card 108 is inserted into the pocket 306 with the contactless IC chip 110 facing the alignment indicator 314 . This places the IC chip 110 into electrical contact with the antenna end segments 312 and enables contactless operation of the function provided by the chip.
Alternatively, the micro-sized card 108 may be operatively stored in a carrier provided on the housing of a mobile telephone. Since many people today typically keep their mobile telephones close at hand and readily accessible, it would be very convenient for them to keep the micro-sized contactless card within the housing of a mobile telephone. With this arrangement, a user only needs to wave the mobile telephone in front of the reader when necessary to use the contactless card, rather than having to rummage for the contactless transaction module in his or her wallet, purse or bag.
FIG. 9 shows a cover 50 in accordance with the present invention attached to a mobile telephone 40 . Cover 50 defines an interior space having a thickness at least sufficient to accommodate the thickness of a contactless transaction card 108 and a holder 60 ( FIG. 11 ) into which the contactless transaction module is inserted. As can be seen in FIGS. 10–12 , cover 50 includes stationary tabs 52 formed along the bottom edge thereof for engaging with corresponding slots formed in the housing of mobile telephone 40 .
As seen in FIG. 9 , cover 50 is shown to be attachable to the mobile phone along the top edge of cover 50 by a latch mechanism controlled by resilient pushtab 54 . For example, an upwardly-facing hook-type latch may be formed at the base of pushtab 54 , wherein the latch catches under a ledge 56 formed along the inner surface at the top edge of cover 50 when the cover is attached to mobile phone 40 . Alternatively, pushtab 54 and the corresponding latch may be formed on the top edge of cover 50 , to catch a corresponding ledge formed on the housing of mobile phone 40 .
Cover 50 can be attached to mobile phone 40 by inserting tabs 52 into the corresponding slots formed in the housing of mobile phone 40 , and pressing the top edge of cover 50 against mobile phone 40 until the latch on tab 54 catches under ledge 56 on cover 50 or on the housing of mobile phone 40 , depending on the configuration of the cover and phone.
Cover 50 can be detached from mobile phone 40 by pressing on pushtab 54 to release the latch from the ledge on cover 50 or on the telephone housing, whereby cover 50 can be lifted off the surface of mobile phone 40 so as to disengage tabs 52 from their respective slots in the phone housing.
The resiliency of pushtab 54 may be provided by a spring which secures the pushtab to the mobile phone housing or to cover 50 , or may be provided simply by the naturally deformable characteristic of a plastic material from which the tab is formed.
Of course, cover 50 can be adapted in shape and dimensions to accommodate different styles of mobile telephones. Moreover, depending on the handset style of the mobile telephone, particularly those in which a detachable battery unit forms the back cover of the phone housing, cover 50 may be constructed as an additional cover over the battery unit. In this variation, cover 50 may optionally be formed with inwardly-facing detents or other protruding elements along the side edges of cover 50 , for engaging corresponding grooves or slots formed on the battery unit or phone housing. Cover 50 may then be slid on and along the battery unit to engage and disengage cover 50 into position on the phone and to remove the same.
A first embodiment of such a cover 50 is shown in FIGS. 10 and 11 . In this embodiment, ridges 62 and 64 are formed on the interior surface of cover 50 which correspond in shape to the micro-sized card 108 . Ridges 62 , 64 may have a height as great as the thickness of card 108 , but may be lower. Ridges 62 and 64 serve as positioning guides to maintain the position of a contactless micro-sized card 108 inserted into holder 60 .
A retaining strip 68 is affixed to the interior surface of cover 50 by posts 66 and spans from the vicinity of the end of ridge 62 to the vicinity of the end of ridge 64 , across the space substantially encompassed between ridges 62 and 64 . The length of retaining strip 68 is at least equal to the corresponding length or width dimension of card 108 . The surface of retaining strip 68 facing the interior surface of cover 50 is preferably situated at a height which is very slightly less than the thickness of card 108 , to provide tension against card 108 when inserted into holder 60 , but not at a height so low as to prevent insertion of card 108 into holder 60 . Retaining strip 68 serves to securely hold card 108 in place against ridges 62 and 64 when the card is inserted into holder 60 .
Ridges 62 and 64 , posts 66 , and retaining strip 68 are preferably constructed of the same materials used to form the interior surface of cover 50 . Alternatively, retaining strip 68 may be made of a material having elasticity to enhance its retaining function.
Cover 50 may be provided with an antenna 30 already “built-in” on the surface of the cover 50 , with antenna ends 34 being provided at a location such that they would naturally line up with the IC 110 on the contactless card 108 when subsequently inserted into holder 60 . The antenna ends 34 may be provided either on the interior surface of cover 50 or on the surface of the retaining strip 68 which faces an inserted card 108 .
In the case in which the micro-sized card 108 is sized and shaped like a plug-in sized SIM card, the card 108 is inserted into holder 60 at an orientation such that the angled corner 14 is aligned with the position of ridge 62 , and then sliding the card 108 under retaining strip 68 until the inserted corners of the module abut ridges 62 and 64 , as shown in FIG. 10 . Of course, the orientation of holder 60 can be varied so that the angled corner of the inserted card 108 is positioned to the upper right side of the cover as opposed to the upper left side as illustrated in FIGS. 10 and 11 , or so that the angled corner is positioned at the lower left or lower right corner of the holder, wherein the card 108 is inserted from above the retaining strip 68 as seen in the drawings. Alternatively, ridge 64 can be designed to conform to the corner adjacent the angled corner of a micro-sized card 108 in the short dimension as opposed to the long dimension. Similarly, ridge 62 can be positioned to orient the angled corner marking at the upper left, upper right, lower left, or lower right corner of holder 60 .
Of course, if the size and shape of micro-sized card 108 is formed to be different from that of a plug-in sized SIM card and as illustrated in the drawings, holder 60 in cover 50 , specifically ridges 62 and 64 , should be correspondingly shaped to conform to the size and shape of the card 108 .
In view of the various possible orientations and configurations of micro-sized card 108 in holder 60 , ridges 62 and 64 should be configured so that when a micro-sized card 108 is inserted in holder 60 , IC 110 on micro-sized card 108 will be placed in the appropriate position facing the interior surface of cover 50 to become aligned with the ends 34 of antenna 30 provided on the surface of cover 50 , as seen in FIG. 11 .
Another embodiment of a carrier for a micro-sized contactless transaction card is shown in FIG. 12 . In this embodiment, a holder for a contactless transaction card is formed as a pocket 70 on the interior surface of cover 50 . Pocket 70 is formed by an envelope 72 securely attached to the interior surface of cover 50 , and is sealed or has a barrier along three of the four sides to prevent a contactless transaction card inserted therein from sliding out. The width of envelope 72 is sized to snugly accommodate the contactless transaction card therein, and the height thereof is preferably less than that of the card.
Envelope 72 also includes a window 74 large enough to enable the user to push an inserted module out of pocket 70 with his or her finger. Pocket 70 is positioned on the interior surface of cover 50 with its bottom end 78 close to one edge of cover 50 and pocket opening 76 positioned more towards the center of cover 50 , relative to bottom end 78 . To insert the card, the module is laid against the interior surface of the cover 50 above the pocket opening 76 and slid into pocket 70 .
Similarly to the carrier embodiment shown in FIGS. 10 and 11 , the antenna is permanently affixed on the surface of the cover, with the ends of the antenna located at the appropriate location to be aligned with the IC when the contactless transaction card is inserted into pocket 70 . Here, it is important that the contactless transaction card be inserted so that the side containing the IC is facing the surface of cover 50 , so that the IC lines up with the ends of the antenna provided on the cover.
Carriers for the contactless transaction modules according to the present invention may be embodied in alternative forms other than as the adapter 300 or a cover for a mobile telephone as disclosed above. For example, such carriers may be formed as a cover or an accessory for a laptop or notebook computer, a palmtop or handheld organizer or computing device such as a personal digital assistant, or any other type of portable electronic and/or communication device. Such carriers may be embodied in any form which may be convenient to a mobile user, so long as the carrier includes a holder for a contactless transaction module and an antenna provided in or on the carrier at a location so as to be aligned with a contactless transaction card when the card is inserted into the holder.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. | A contactless transaction card includes first and second contactless integrated circuit (IC) chips and an antenna connected to both ICs for enabling contactless operation of the functions provided by each IC. The contactless transaction card is preferably fabricated by laminating together a plurality of layers to form a carrier substrate. The antenna and one of the IC chips is embedded within the layers of the carrier substrate so as to be permanently formed in the card, while the second IC chip is provided in the card in a region formed as a micro-sized card which is removable from the main portion of the carrier substrate. Additionally, an adapter card includes a holder for retaining a micro-sized contactless transaction card and contains an antenna arranged to connect with the micro-sized card. The adapter may be used to convert the micro-sized transaction card into a full-sized card and to enable access to the information associated with the IC chip contained in the card. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a looper drive mechanism for a sewing machine, and more particularly to a looper drive mechanism for transmitting rotation of a main shaft to a looper.
2. Description of the Prior Art
A looper drive mechanism with a grooved cam as shown in FIG. 6 has been conventionally used as a looper drive mechanism for an overlock machine (Japanese Patent Application Laid-Open No. Sho 62-176487). In this looper drive mechanism, a barrel-shaped drum cam 201, provided with grooves 201a and 201b, is attached to a main shaft 200. When the barrel-shaped drum cam 201 rotates together with the main shaft 200, the rollers 203a and 203b engage the grooves 201a and 201b, resulting in oscillation of the looper drive shafts 206 and 207.
However, in the mechanism of this type with the barrel-shaped drum cam 201, since the drum cam 201, the looper drive shafts 206 and 207 and the looper are assembled by attaching to the main shaft 200 during the assembling process, the manufacture process is complicated, time-consuming and laborious. Also, in order to machine the grooves 201a and 201b in the drum cam 201, it is necessary to design and manufacture a special machine, resulting in increased manufacture cost.
To cope with such problems, a looper drive mechanism with a slant cam and a cam follower has been proposed (Japanese Patent Application Laid-Open No. Hei 5-15681). In this looper mechanism, as shown in FIG. 7, looper drive cams 301 and 302, each of which is a cylindrical slant cam are fixed to a main shaft 300. The looper drive bifurcated cam followers 305 and 306, each in the form of a U-shaped cam follower, are attached to looper drive shafts 303 and 304, and are engaged with the looper drive cams 301 and 302. The looper drive bifurcated cam followers 305 and 306 are mounted on the looper drive shafts 303 and 304 with freedom to cancel the displacement between the main shaft 300 and the looper drive shafts 303 and 304. Accordingly, as the main shaft 300 rotates, the slant angle of the cam surfaces of the looper drive cams 301 and 302 varies in the range of ±θ in a plane including the main shaft 300, whereby the looper drive bifurcated cam followers 305 and 306 are angularly moved to rotate the drive shafts 303 and 304.
However, the looper drive cams 301 and 302 and the looper drive bifurcated cam followers 305 and 306 are in line-contact with each other. Accordingly, when the looper drive cams 301 and 302 are angularly moved, the looper drive cams 301 and 302 and the looper drive bifurcated cam followers 305 and 306 generate heat due to frictional resistance. As a result, the durability of the looper drive cams 301 and 302 and the lopper drive bifurcated cam followers 305 and 306 suffers. It is therefore difficult to rotate the main shaft 300 at a high speed. Also, since the frictional resistance adversely affects the components even at a low rotational speed, a large motor having a large output power is required.
SUMMARY OF THE INVENTION
In view of the foregoing difficulties inherent in the conventional looper drive mechanism, an object of the invention is to provide a looper drive mechanism which is less expensive but superior in quality, and which does not require high precision in assembling.
In order to attain this and other objects, according to the present invention, there is provided a looper drive mechanism for a sewing machine, comprising: at least one looper; a looper drive shaft for driving the looper; a main shaft extending across one plane transverse to the looper drive shaft; and transmission means for transmitting rotation of the main shaft to the looper drive shaft. The transmission means includes at least one slant grooved cam fixed to the main shaft and having a groove extending around its full circumference and slanted relative to the main shaft; a U-shaped follower having two rollers each of which is supported by the looper drive shaft for rotation about its own axis within the groove of the slant grooved cam; and a connection pin for pivotally mounting the U-shaped follower on the looper drive shaft so that the U-shaped follower is not rotatable in a direction in parallel with a line connecting the two rollers, but is rotatable within a plane perpendicular to the line connecting the two rollers with each other.
In one embodiment of the looper drive mechanism according to the invention, the transmission means is provided in one looper. In another embodiment of the looper drive mechanism according to the invention, the transmission means is provided in an upper looper and a lower looper. The two slant grooved cams are fixed to the main shaft so that the two slant grooved cams have offset phases in association with the upper and lower loopers. The phases of the two slant grooved cams are offset from each other in the range of 30° to 50°.
Furthermore, the inner diameter of a hole formed in the U-shaped follower, into which the looper drive shaft is inserted, is larger than the outer diameter of the looper drive shaft.
When the slant cam rotates together with the main shaft, the angle of the groove of the slant grooved cam is changed within the plane including the main shaft. Defining the maximum angle between the groove of the slant grooved cam and perpendicular to the main shaft as θ, the slant angle varies within ±θ as the main shaft rotates. Accordingly, the U-shaped follower provided with the rollers engaged within the groove is swung within that angle range so that the looper drive shaft which supports the looper is angularly moved and the looper mounted on the looper drive shaft is driven. In this case, the rollers are rotated about their own axes and it is possible to angularly move the U-shaped follow to thereby reduce the frictional resistance in the drive system.
Thus, it is possible to enhance the durability of the sewing machine and to further reduce the drive torque of the sewing machine. Accordingly, a motor having low output power may be used.
Also, since the two slant grooved cams associated with the upper and lower loopers are mounted on the main shaft with their phases offset from each other, the mechanism is suitable for a single-needle, three-thread overlock machine. The phase offset range is preferably 30° to 50° for the normal sewing operation.
Furthermore, the U-shaped follower is not rotatable about the connection pin in a plane parallel with a line connecting the rollers, but is rotatable in a direction perpendicular to the line connecting the rollers. Accordingly, in assembling, it is unnecessary to effect adjustment such that the rotational center of the slant grooved cams is coincident with the looper drive shaft. Thus, the assembling work is simplified. Furthermore, excessive working precision is not needed for the positioning of the hole of the looper drive shaft, and hence the machining of the hole in the looper drive shaft relative to the main shaft may be simplified.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a perspective view showing a part of an overlock machine to which a looper drive mechanism according to the present invention is applied;
FIG. 2 is an exploded perspective view showing the looper drive mechanism according to one embodiment of the invention;
FIG. 3 is a frontal view showing looper drive cams according to one embodiment of the invention;
FIG. 4(a) is a frontal view showing the looper drive mechanism according to the embodiment of the invention;
FIG. 4(b) is a cross-sectional view taken along the line A--A of FIG. 4(a);
FIG. 5 is a side elevational view showing the looper drive mechanism according to the embodiment of the invention;
FIG. 6 is a front view showing a conventional looper drive mechanism using barrel-shaped drum cams; and
FIG. 7 is a front view showing a conventional looper drive mechanism using slant cams.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment will now be described with reference to the accompanying drawings, in which a looper drive mechanism according to the present invention is applied to a single-needle, three-thread overlock machine.
FIG. 1 shows the overall appearance of the single-needle three-thread overlock machine which is provided with a single needle 1 for substantially vertical linear reciprocating motion. A lower looper 2 travels with an arcuate reciprocating motion across the path of the needle 1, under a needle plate. An upper looper 3 travels with an elliptical reciprocating motion across the path of the needle 1 above the needle plate. Two looper drive cams 6 and 7, which are cylindrical slant grooved cams corresponding respectively to the upper and lower loopers 2 and 3, are attached to a main shaft 5 which rotates coaxially with a pulley 4.
As shown in FIG. 2, a needle rod eccentric cam 8 is formed on the looper drive cam 6 for driving the needle rod substantially vertically. A needle rod vertical rod 9 is held on the needle rod eccentric cam 8 by a base mount 10. Also, the looper drive cam 6 is fixed to the main shaft 5 by fastening screws, connection pins and a thrust receiver 11. The looper drive cam 7 is likewise fixed to the main shaft 5 by fastening screws and connection pins and is axially positioned through a positioning spacer 12. Thus, the looper drive cams 6 and 7 rotate together with the main shaft 5.
A groove is formed around the full circumference of each of the looper drive cams 6 and 7 and is slanted relative to the main shaft 5 at angles θ 1 and θ 2 with respect to planes perpendicular to the main shaft 5. Namely, in the single-needle, three-thread overlock machine according to the embodiment, the upper looper 3 is so constructed that it's motion is offset an angle of, for example, about 35° in terms of the rotation of the main shaft 5 relative to the lower looper 2. In correspondence therewith, the looper drive cam 7 is fixed to the main shaft 5 offset at an angle of about 35° relative to the looper drive cam 6. Accordingly, if, as shown in FIG. 3, the angle between the groove of the looper drive cam 6 and a plane perpendicular to the main shaft 5 (i.e., the paper surface of FIG. 3) θ 1 is at maximum. The looper drive cam 7 reaches a maximum angle θ 2 between its groove and a plane perpendicular to the main shaft 5 after the main shaft 5 has rotated through an angle of 35° beyond maximum θ 1 .
Incidentally, the grooves of the looper drive cams 6 and 7 may be machined by a general use lathe, thus reducing manufacture cost.
As shown in FIGS. 4(a) and 5, the lower looper 2 is fixed to a lower looper shaft 14 through a lower looper drive arm 13. As the lower looper drive shaft 14 rotates, the lower looper 2 is driven with an arcuate reciprocating motion within a plane perpendicular to the lower looper drive shaft 14 (i.e., the paper surface of FIG. 4(a)). The upper looper 3 is fixed to an upper looper drive shaft 17 through an upper looper drive arm 16. As the upper looper drive shaft 17 rotates, the distal end of the upper looper drive arm 16 is likewise driven with an arcuate reciprocating motion. An upper looper mount shaft 15 is connected to an end of the drive arm 16 through a pin 18 and its motion is restricted by a pivot 19. As the end of the drive arm 16 is driven with an arcuate reciprocating motion, the upper looper 3 mounted on the distal end of the drive shaft 16, in turn, is driven with an elliptical reciprocating motion, reaching top dead center of the needle plate 20 by crossing the needle plate 20 from below. The looper drive shafts 14 and 17 for driving these lower and upper loopers 2 and 3 are supported by the side plate of the machine (not shown) so that axes of the drive shafts 14 and 17 are both perpendicular to the main shaft 5.
Also, looper drive bifurcated cam followers 21 and 22, which respectively engage the looper drive cams 6 and 7, are mounted on the looper drive shafts 14 and 17, respectively. Since the structure of these bifurcated cam followers 21 and 22 are exactly the same, the following explanation will treat the bifurcated cam follower 21 only. As best seen in FIG. 4b, the bifurcated cam follower 21 is a U-shaped member with roller shafts 26 being fixed to the bifurcated ends by fastening screws. Rollers 25 are rotatably mounted on the roller shafts 26. The rollers 25 are engaged within the groove of the looper drive cam 6. The slant angle of the groove varies as the looper drive cam 6 rotates, whereby the rollers 25 swing following the angular movement to rotate the drive shaft 14.
The interconnection between the bifurcated cam follower 21 and the looper drive shaft 14 will now be explained. As shown in FIG. 2, the looper drive shaft 14 is inserted into a central hole 21a formed in the bifurcated cam follower 21 with an inner diameter that is somewhat larger than an outer diameter of the looper drive shaft 14. A connection pin 23 is inserted into a hole 14a in the looper drive shaft 14 and a hole 2lb the bifurcated cam follower 21 and is held therein with E-rings 24. A central portion of the connection pin 23 is fastened to the looper drive shaft 14 by a screw. Thus, the bifurcated cam follower 21 is rotatable in a plane perpendicular to a line connecting the rollers 25 but is not rotatable in a plane in parallel to the line connecting the rollers 25. Accordingly, even if the groove of the looper drive cam 6 is not centered relative to the centerline of the looper drive shaft 14 when the rollers 25 are engaged within the groove of the looper drive cam 6, the bifurcated cam follower 21 will nevertheless rotate in a plane perpendicular to the rollers 25 to thereby cancel the displacement from center, so that the looper drive shaft 14 may be positively driven.
Since the transmission means of the looper drive mechanism according to this embodiment is so designed as to cancel any offset between the centerline of the looper drive shaft 14 and the groove of the looper drive cam 6 in the lateral direction, it is possible to smoothly transmit motion from the looper drive cam 6 through the bifurcated cam follower 21 to the looper drive shaft 14.
In order to assemble the looper drive mechanism, the looper drive cam 6 provided with a needle rod eccentric cam 8, the needle rod vertical rod 9, the mount base 10 and the thrust receiver 11 are first fixed to the main shaft 5, and the looper drive cam 7 is then fixed to these components through the positioning spacer 12 to complete the assembly on the main shaft 5. Apart from this assembly, the looper drive shafts 14 and 17 provided with the looper drive bifurcated cam followers 21 and 22 and the pivot 19 are mounted on the machine side plate, the lower looper drive arm 13, to which the lower looper 2 is fastened, is fixed to the looper drive shaft 14, and the upper looper mount shaft 15, to which are fastened are the upper looper 3 and the upper looper mount shaft drive arm 16, is mounted on the looper drive shaft 17 with the pivot 19, to thereby complete the assembly on the machine side plate. After the assembly on the main shaft 5 side and the assembly on the machine side plate side are thus separately completed, the assembly on the machine side plate is mounted on the machine body so that the looper drive bifurcated cam followers 21 and 22 are engaged with the looper drive cams 6 and 7, respectively. Accordingly, the assembly is quite easy and the time needed for assembling is reduced.
The operation of the looper drive mechanism thus constructed will now be explained.
When the looper drive cams 6 and 7 are rotated by the rotation of the main shaft 5, the slants of the grooves of the looper drive cams 6 and 7 are changed in the ranges of ±θ 1 and ±θ 2 relative to a plane in which the main shaft 5 lies and which is perpendicular to the looper drive shafts 14 and 17. As a result, the looper drive bifurcated cam followers 21 and 22 provided with the rollers 25 engaged within these grooves are swung and the lower looper drive shaft 14 and the upper looper drive shaft 17 move integrally with the swinging movement through angles in the ranges of ±θ 1 and ±θ 2 . In this case, even if, with vibration of the main shaft 5, one of the rollers 25 is subjected to a thrust load in, for example, the left direction, the other roller 25 cancels the thrust load by pressing against the grooves of the looper drive cams 6 and 7. Accordingly, thrust due to vibration generation of the main shaft is suppressed to thereby make it possible to always attain stable arcuate reciprocating motion of the loopers 2 and 3. The rotation of the lower looper drive shaft 14 is transmitted to the lower looper 2 through the lower looper drive shaft 13 without any change, and the lower looper 2 is driven in an arcuate reciprocating motion within a plane that is perpendicular to the lower looper drive shaft 14. On the other hand, as the upper looper drive shaft 17 rotates, the end of the upper looper drive arm 16 is driven in an arcuate reciprocating motion to thereby move the upper looper mount shaft 15 connected to the drive arm 16 substantially vertically up and down. The upper looper mount shaft 15 is restricted by the pivot 19 and, at the same time, its movement causes the distal end to move with an elliptical reciprocating motion. Thus, the upper looper 3 has an elliptical reciprocating motion.
For instance, assume that a state where the needle 1 is located at the top dead center above the needle plate 20 is 0° of rotation of the main shaft 5 as shown in FIG. 5, and a state where the needle 1 is located at the bottom dead center is 180° of rotation of the main shaft 5 as shown in FIG. 4. When the rotation of the main shaft 5 is 0°, the groove of the looper drive cam 6 is at the maximum slant position of +θ 1 , and the lower looper 2 is located at the rightmost end. When the rotational position of the main shaft 5 is at 180°, the groove of the looper drive cam 6 is at the maximum slant position of -θ 1 , and the lower looper 2 is located at the left-most end. The phase of the upper looper 3 is offset by about 35°. When the rotational position of the main shaft 5 is at 35°, the groove of the looper drive cam 7 is at the maximum slant position of +θ 2 , and at this time, the upper looper 3 is located at the top dead center as shown in FIG. 5. When the rotational position of the main shaft 5 is 180°+35°, the groove of the looper drive cam 7 is at the position of -θ 1 , and at this time, the upper looper 3 is located at the bottom dead center as shown in FIG. 4.
Incidentally, in the foregoing embodiment, the upper looper 3 operates with an offset angle of about 35° relative to the lower looper 2. It is apparent that the invention is not limited to this offset angle and it is possible to carry out the sewing operation normally within an offset angle range of 30° to 50°.
Furthermore, in the foregoing embodiment, the needle 1 is moved up and down at a slight slant angle relative to the exact vertical direction and the upper looper 3 is moved within the vertical plane; that is, the upper looper drive shaft 17 is perpendicular to the vertical plane. However, it is possible to apply the invention to the case where the motion plane of the upper looper 3 is out of the vertical plane in relation to the motion of the needle 1. In this case, the upper looper drive shaft 17 is mounted so as to be perpendicular to the motion plane of the upper looper 3.
Also, the foregoing embodiment has been described with reference to a three-thread overlock machine but it is apparent that the looper drive mechanism according to the present invention is not limited to such an overlock machine and may be applied to any other type machine having at least one looper.
As is apparent from the foregoing description, in the looper drive mechanism according to the present invention, the looper drive shaft is driven by the cam followers provided with the rollers engaged with the grooves formed in the cams fixed to the main shaft, whereby the frictional resistance becomes small and the heat generation of the looper drive mechanism may be prevented, resulting in enhancement in durability of the sewing machine. Further, it is possible to reduce the drive torque of the machine so that a motor having a small output power may be used. In addition, the assembling does not require excessively high accuracy. It is therefore possible to provide a looper drive mechanism with high quality and low cost.
Also, in the looper drive mechanism according to the present invention, it is possible to assemble the machine side plate on which the loopers are to be mounted and the machine body on which the main shaft is to be mounted, in separate steps. Accordingly, the assembling work may be extremely simplified and time needed for assembling may be considerably shortened.
Various details of the invention may be changed without departing from its spirit or its scope. Furthermore, the foregoing description of the embodiments according to the present invention is provided for the purpose of illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. | A looper drive mechanism for a sewing machine includes: two loopers; looper drive shafts for driving the loopers; a main shaft extending across one plane transverse to the looper drive shafts; and torque transmission units for transmitting rotation of the main shaft to the looper drive shafts. The transmission units include: two slant grooved cams fixed to the main shaft and having grooves each extending through a full circumference and slanting relative to the main shaft; U-shaped followers each having two rollers, each of the rollers being supported by the looper drive shaft and rotating about its own axis within the groove of the slant grooved cams; and connection pins for pivotally mounting the U-shaped followers on the looper drive shafts so that the U-shaped followers are not rotatable in a direction in parallel with a line connecting the two rollers with each other but rotatable in a direction perpendicular to the line connecting the two rollers with each other. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a means whereby an operator controls a machine, for example, the control of an earth working back-hoe digger. The operator is typically located upon the machine and operates it through pushing or pulling numerous levers arranged before him. Each lever usually activates only one motion of the many required to perform useful work. The operator must be trained as to the functions of each lever and must concentrate upon the sequence and degree of actuation required to obtain the desired motions. Improper sequencing or over-actuation can cause accidents such as load dropping or striking objects. Efficiency and speed of operation are very dependent upon operator skill at manipulating this multiplicity of levers with split-second timing.
2. Prior Art
This control problem has been recognized in previous inventions. Askins (U.S. Pat. No. (3,642,159) utilizes one manually operated valve, linkages, and a pneumatic circuit to sequence movements on a shovel loader. Wallace (U.S. Pat. No. 3,614,273) controls the boom arms and bucket on a front-end loader through one control handle, linkages, and three valves, providing sequential operation. Fuzzell (U.S. Pat. No. 3,524,562) controls the bucket of a loader by means which electrically release a detent which is holding the control valve at a given setting. Horsch (U.S. Pat. No. 3,534,881) utilizes linkages connected to the control valve to maintain bucket position during raising and lowering. These inventions all relate to a relatively simple machine utilized to perform repetitive operations. The operator cannot interrupt the sequence at will and quickly, and he must be seated upon the equipment. Ito and Aihara (U.S. Pat. No. 3,695,377) remotely control a tractor through electrical signals sent through a control cable to operate relays and electropneumatic actuators connected to the various tractor controls.
3. Utility
The operator of farming, mining, or earth-moving machinery often finds himself in a noisy, dusty (or wet), vibrating, and generally unpleasant environment. He may not be in the best location to observe the results of his actions. He may also be in physical danger such as cave-ins when working in tunnels, at the base of cliffs, or in excavations; his machine could tumble down steep slopes or have the ground give way beneath him when working around excavations; he may be in toxic or inflammable environments; or he might accidentally sever high pressure pipes or contact high voltage lines. This invention allows the operator to move his operating controls to a location away from the equipment and operate the equipment by actuating a size-scaled version of the movably connected portions of the equipment with the actual equipment mimicking his motions. A feedback feature restricts the operator's motions when the equipment is incapable of following within certain limits. In many cases it is not desirable to remove the operator from the machine. The use of a vehicle mounted control station provides the improved control inherent with this system, thereby enhancing the efficiency of the operation.
SUMMARY OF THE INVENTION
This invention describes a three-cylinder control system for powered machinery in which a master cylinder attached to a particular linkage at the control station is connected hydraulically with a slave cylinder attached to the corresponding working element on the machinery and also to a control cylinder that is attached to the machinery lever that actuates that particular working element on the machinery. With the machinery power turned off, the master cylinder timing valves are opened and the control station handle is manipulated until the control station linkages have the same geometrical configuration as the machinery, at which point the master cylinder timing valves are closed. A movement of the control station handle moves one or more of the master cylinder pistons, forcing fluid into the control cylinders since the slave pistons have not moved. The control cylinder pistons move the original equipment levers, powering the machinery, thereby moving the slave cylinders, forcing their fluid into the control cylinders, and returning the control pistons to their centered positions. This returns the original equipment control levers to the neutral position and stops the motion of the machinery so that it corresponds to the new position of the linkages on the control station. By moving the control station handle in the desired fashion, the machinery is directed to follow without the operator having to think about the control of each motion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the three-cylinder system of this invention and also shows an alternate to the control cylinder.
FIG. 2 is a partial cross-sectional view of the accumulator shown in FIG. 1.
FIG. 3 is a schematic of a throttle control system which employs the hydraulic control system shown in FIG. 1.
FIG. 4 is a partial, cross-sectional view of the enlargement of the slave cylinder shown in FIG. 3.
FIG. 5 is a perspective view of a remote station controlling a wheel-backhoe using multiple control systems of the type shown in FIG. 1.
FIG. 6 is a side view of the control station mounted on a vehicle using the control system of the type shown in FIG. 1.
FIG. 7 is a perspective view of the enlargement of the control station shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A control station, either mounted on the machine or at a remote location, for the working elements of the machinery, is constructed to a scale convenient for the operator. The station may incorporate a counterweighting system and motion locks. To each rotating or sliding linkage on both station and machine are mounted double-acting hydraulic cylinders or rotary actuators. Those on the station are called master cylinders and those on the equipment are called slave cylinders. A third set of double-acting cylinders, called control cylinders, are used to push or pull the original machinery control levers. Tubing is used to connect the various cylinders together. Timing and locking valves can be provided to permit positioning the pistons of the various cylinders with respect to each other. Accumulators can pressurize the system and enable the system to withstand temperature variations. The hydraulic system is filled with any low viscosity fluid as the force and displacement working medium.
As shown in FIG. 1, master cylinder A with push rod 12 displaces fluid volumes 1 and 2 such that fluid is forced from volume 1 into volume 3 of control cylinder C by means of tubes 15, 24, and 19. Fluid from volume 1 also attempts to enter volume 5 of slave cylinder B via tubes 15, 24, and 16; however, volume 5 is fixed because slave cylinder piston rod 13 cannot move since it is attached to the machinery which has not yet moved. The increase in fluid in volume 3 forces fluid from volume 4 through tubes 20, 25, and 18 into volume 2; therefore, control cylinder piston rod 21 is slaved to follow master cylinder piston rod 12. The movement of control cylinder piston rod 21 actuates valve lever 8 which in turn through the normal hydraulic or electric system of the machine moves a linkage on the machine. By moving lever 8, a corresponding motion is generated in the linkage of the machinery. The movement of the linkage creates a movement of slave cylinder piston rod 13 causing the fluid in volume 6 to be displaced through tubes 17 and 20 into volume 4 of the control cylinder C. Increased fluid in volume 4 causes fluid to flow from volume 3 through tubes 19 and 16 into volume 5. Volumes 3 and 4 are equalized in cylinder C moving lever 8 to a central position which stops the motion of the linkage. Continued motion of master cylinder piston rod 12 keeps control cylinder C in an unequalized position which continues the motion of the linkage until such time as the slave cylinder piston rod 13 is in a corresponding position with master cylinder piston rod 12. Should the linkage be unable to move because of striking an object or reaching its mechanical limit, master cylinder piston rod 12 will be prevented from further motion. This provides position feedback to the operator. A timing valve 10 may be provided to allow flow between volume 1 and volume 2 so as to permit the control station linkages to be placed in a configuration similar or relative to the working elements of the machinery, thereby enabling the control station to have the same geometric configuration as the machinery, or a configuration that is more comfortable to the operator rather than a true geometric configuration of the machinery. An additional timing valve 9 may be provided to allow free flow of fluid between volumes 5 and 6 and volumes 3 and 4, thus permitting the normal operation of the equipment through manual actuation of lever 8. Closing valves 23 hydraulically lock the master cylinder piston rod 12 to hold the position of the linkage. Quick disconnect couplings 42 may be provided on the machine to facilitate convenient removal of the remote portions of the circuit. The control cylinder C is intended to be used as a retrofit to existing equipment. For original equipment installation on hydraulic machines, it is more practical to incorporate a pilot operated valve 11 in the basic construction of the machine's hydraulic system. This valve 11 would still have a lever actuator 14 to permit conventional manual operation.
A fluid pressurization system may be provided by accumulator 7. The accumulator is shown in partial cross-sectional detail in FIG. 2. The accumulator 7 provides means to maintain pressurization in the system, and an expansion volume to accommodate system temperature fluctuations. Other desirable features of this accumulator are that it provides the following functions:
a. rigid location to attach the hydraulic lines from a remote control station,
b. includes a pump means to increase the system pressure,
c. a visual means of indicating fluid level in the system,
d. incorporates overpressure relief to reduce the possibility of equipment damage due to operator attempting to overload control station,
e. incorporates timing valve 9 at a convenient location on the machine, allowing the machine to be operated manually when the control station is disconnected,
f. incorporates air venting means,
g. and fluid pressure gage.
Accumulator 7 is provided fluid from a reservoir by gravity feed through tube 31 into volume 26. Raising plunger 27 by hand draws fluid from volume 26 past check valve 28. Manual depression of plunger 27 forces the fluid past foot valve 29 into volume 30. Volume 30 is connected to the system through lines 15, 24, 18, and 25. Continued pumping of plunger 27 fills volume 30 raising piston 32 against spring 33. The spring 33 provides a force on the fluid in volume 30. The vertical position of piston 32 is indicated by the extent of the height of pump housing 34 above the top of the accumulator 7. Air trapped in volume 30 is expelled through pressure relief valve 35 into volume 26 where it raises through tube 31 into the fluid storage reservoir (not shown). The system pressure is indicated by gage 36 after all air is bled from all parts of the system. Volume 30 communicates with tubes 18 and 25 through fitting 37. Tubes 15 and 24 communicate with each other through fittng 43, but do not communicate with volume 30 since timing valve 9 is closed. Pulling plunger 39 of timing valve 9 and holding it open with wire clip 40 allows the free communication of fluid between tubes 24 and 25 (also tubes 15 and 18) through volume 30. On the occasion of overpressure of tubes 17, 25, and 18, fluid will flow into volume 30 and may vent through valve 35 and/or force down plunger 39 against spring 38 allowing fluid to pass into tubes 15 and 24. Overpressurization of tubes, 15, 16, and 24 is relieved through valve 41 through volume 30 into tubes 18 and 25 and/or out through valve 35.
One particular embodiment of this invention useful as a control system for an engine is shown in FIGS. 3 and 4. FIG. 3 is a schematic of the throttle control, while FIG. 4 is an enlargement of the slave cylinder B of FIG. 3. When remotely advancing a throttle, a question always exists as to the actual engine speed since that is a function of engine load as well as throttle setting. Use of the basic three-cylinder control system of FIG. 1 relieves this problem. In this case, the control cylinder piston rod 21 is connected to the throttle 45 and the position of slave cylinder piston rod 13 is determined by the length of an engine-driven flyball inkage 46. Advancing the remote throttle 47 displaces fluid from volume 2 through tubes 18, 25, and 20 into volume 4 of the control cylinder C. This displaces the piston rod 21 and the throttle linkage 49 connected to it. The engine 50 will spend up and the engine-driven shaft 51 will rotate faster, causing the weighted linkages 46 to separate by centrifugal force. The centrifugal force is balanced by the force of a spring located at 52 and/or 53. The separation of the linkages 46 in response to the larger centrifugal force reduces the distance between the engine-driven shaft 51 and the swivel bearing 55, thereby moving the piston rod 13 of the slave cylinder B, displacing fluid from volume 5 through tubes 16 and 19 into volume 3 of the control cylinder C, retarding the throttle 45. As the engine 50 slows in response to the new throttle setting, the flyball linkages 46 are pulled together by the springs 52 and/or 53, displacing fluid from volume 6 through tubes 17 and 20 into volume 4, thereby advancing the throttle 45. The tubes and volumes are sized to provide a damping to this oscillatory behavior and the engine settles to a consant speed determined by the fluid distribution set by the remote throttle 47. An increase in load will slow the engine, thereby displacing the fluid from volume 6 into volume 4 as before, advancing the throttle 45. A reduction of load has the opposite effect. Should the engine stop due to stalling or running out of fuel, the piston rod 13 of slave cylinder B would move to its extreme, forcing much of the fluid from volume 6 through tubes 17 and 20. Volume 4 of the control cylinder C is not large enough to accept this much fluid so it will flow into volume 2 of the master cylinder A, forcing piston rod 47 to move within its friction position holder 56, indicating to the operator that the engine speed has decreased below a controllable level. Valves 57 permit the bleeding of air from slave cylinder B and are present but not shown on all the cylinders and other locations wherever air could be trapped.
An example of a remote control station using the system of this invention is shown in FIG. 5. Multiple master, control, and slave cylinders provide this control although only one control and two slave cylinders are shown on the machinery for sake of simplicity. FIG. 5 is a perspective view of a remote control station 60 controlling a wheel-backhoe 65 with bucket attachment 62. The control station 60 is connected to machine 65 by means of a bundle of hydraulic tubes 63 which connect to the machine by means of rack 64 in which are mounted multiple accumulators (not shown). All master cylinders A are located on control station 60, and some of these master cylinders are shown as rotary actuators instead of as cylinders. Slave cylinders B are located on machine 65, and control cylinders C are located on machine 65 mechanically connected to levers 66. One sample operation is as follows: Associated with actuation of working element 67 is slave cylinder 68, master cylinder 69, and control cylinder 70, and accumulator 71 mounted on rack 64. While sitting at control station 60 the operator pulls handle 72 toward him which causes pivotal motion which displaces fluid from master rotary actuator 69 incorporated in the linkages. The fluid is displaced through tubes enclosed in the structural member 73 to manifold block 74, hence through tube bundle 63 to accumulator 71, to control cylinder 70, and slave cylinder 68. The displaced fluid moves a piston in control cylinder 70, actuating lever 66 which powers a piston in cylinder 75 causing motion about working element 67, resulting in motion of a piston in slave cylinder 68, displacing fluid which causes revers motion of the piston in control cylinder 70 which returns lever 66 to a neutral position stopping the piston in cylinder 75. Continued pulling of handle 72 will continue the displacement of the piston in control cylinder 70 and actuation of control lever 66 and power cylinder 75, resulting in continued motion of working element 67. Each linkage on the machine is controlled by a master A, control C, and slave B cylinder in a similar hookup. Control station 60, as depicted in FIG. 5, shows control means of all functions of the backhoe. Every working element on the machine that is hydraulically controlled is shown on control station 60. In addition, the throttle 47 is hydraulically controlled using the three-cylinder system of this invention (see FIGS. 3 and 4). The other control features, namely, braking 77, steering 76, gear shifting 78, and starting 79 are two-cylinder operations (not part of this invention) and are shown only to depict a complete remote control station. For operator comfort, possible counterbalancing means 80 are shown schematically, relieving the dead weight of the master system linkages.
FIG. 6 depicts the control station 81 and FIG. 7 is an enlargement of same mounted on vehicle 82. The operator sitting in the vehicle seat 83 has handle 84 in his hand. The valves which cause bucket curl and lift both are controlled by systems of the type shown in FIG. 1. Lifting handle 84 results in raising bucket 85. Rotating handle 84 results in curl of bucket 85. Swinging handle 84 in the horizontal plane results in turning vehicle 82 since column 86 is connected directly to the vehicle power steering 87. Forward and reverse control of the vehicle 82 is accomplished by pushing or pulling handle 84 which tilts column 86 actuating transmission lever 88. Vehicle's speed and braking are part of the conventional vehicle control system. Having this control system mounted on the vehicle provides the following advantages: (a) less fatigue on the operator, (b) faster operation of the vehicle, (c) less training needed for operator, and (d) better control of operation of the bucket, vehicle, and therefore, enhanced job performance.
While the invention has been described in detail with respect to a specific embodiment, it will be apparent that many variations are possible. Certain of the functions of devices described herein, including the accumulator, timing, and locking valves, may be accomplished by other mechanisms without departing from the scope of the invention. Other modifications are possible and accordingly it is not intended to limit the invention except as defined by the following claims. | A three-cylinder hydraulic system providing position feedback for controlling powered machinery is described wherein an operator moves a control handle and the various working elements of the machinery respond to follow the path of the control handle, the freedom of movement of which is limited by the ability of the machinery to respond. The system consists of a control station comprised of an assemblage of linkages resembling the machinery to be controlled. Associated with each movable element on both the control station and machine, and with each lever or switch on the machine, are double-acting hydraulic cylinders or rotary actuators. The three cylinders thereby associated with each particular working element and its actuation are connected hydraulically so that the control station cylinder hydraulically manipulates the cylinder that moves the lever or switch that actuates that working element on the machine. The cylinder on that working element on the machine in turn hydraulically manipulates both the control station cylinder and the cylinder that moves the lever or switch. The control station may be located either upon the machinery or at a position remote from the machinery. | 4 |
FIELD OF THE INVENTION
The present invention relates to a cooking area cover panel to be applied separately. More particularly, the invention relates to a cooking area cover panel whose outside dimensions correspond approximately to the dimensions of the cooking area. Preferably this cooking area cover panel is composed of several, in particular of exactly two individual partial cover panels to be applied separately.
BACKGROUND OF THE INVENTION
The known cooking area cover panel is intended for use with a cooking area on which this invention is based (German Utility Model 298 13 303 U1) for a glass ceramic cooking area. As a panel to be applied separately, it or each of the partial cover panels has several spacer feet, in particular at least four spacer feet designed on the underside or applied to the underside. The spacer feet hold the cooking area cover panel itself at a slight distance from the cooking zones of the glass ceramic cooking area, so that normally there is no overheating of the cooking area cover panel.
The known cooking area cover panel consisting of two individual partial cover panels to be applied separately is from the very beginning provided in a ready-to-use condition with spacer feet designed on or applied to the underside. When equipped with taller spacer feet accordingly, this can of course also be used with a cooking area with electric cooking plates inserted individually or with other types of cooking areas, in particular with gas cooking areas. The taller the spacer feet, the greater the amount of space needed for the cooking area cover panel in packaging, shipping and storing.
The teaching according to the present invention is based on the problem of improving the known cooking area cover panel with regard to universal applicability in the optimal way.
SUMMARY OF THE INVENTION
The problem posed above is solved by the cooking area cover panel to be applied separately for a cooking area. The cooking area cover panel is made of a hard material and comprise a plurality of individual partial covering panels having an underside and a top side and spacer feet provided with connecting means for selectively mounting on the cooking area cover panel. The spacer feet are mountable to the underside of the cooking area cover panel in a ready-to-use condition, wherein the spacer feet are separate from the cooking area cover panel in a disassembled condition of the cooking area cover panel.
According to this invention, the spacer feet are first supplied separately from the cooking area cover panel. They may be included in the shipment or purchased separately by the customer. At any rate, the spacer feet are separate from the cooking area cover panel at the time of purchase or delivery of the cooking area cover panel. However, they are provided with-means for attaching them subsequently to the cooking area cover panel. Thus, the customer can attach the spacer feet to convert the smooth cooking area cover panel to the ready-to-use condition with the spacer feet mounted on the underside. Even though the attachment in this connection is permanent, it must not be non-releasable. A temporary detachment may be recommendable especially for cleaning purposes.
The inventive teaching has firstly significant advantages with respect to the packaging and shipping of the cooking area cover plate.
However, this teaching has also considerable advantages with regard to universal applicability of a cooking area cover panel. For example, several sets of spacer feet of different heights could be packaged with a cooking area cover panel (optionally consisting of several partial cover panels) in the as-delivered or purchased state. Then, depending on the cooking area available in each specific case, the customer can select the spacer feet with the proper height and attach them to the cooking area cover panel. The other spacer feet that are not needed can be saved or discarded. This permits universal applicability of the cooking area cover panel, which can be used for a glass ceramic cooking area or for a metal cooking area with electric cooking plates or even for a gas cooking area using gas burners, depending on the customer's wishes.
Possible alternatives also consist of designing the spacer feet for the maximum installed height so they can be cut to the desired height, or they may be designed as multi-part plug-on or stick-on elements. An especially interesting alternative is to design the connecting means as suction cups. It is especially advisable here for the spacer foot to be detachable from the suction cup and therefore to have a catch opening for a catch nub on the suction cup.
All the alternatives have in common the fact that it is the customer or the user of the cooking area cover panel who puts it in the ready-to-use condition by attaching the proper spacer feet for his/her cooking area to the cooking area cover panel.
An independent alternative consists of providing separate elevation feet for the cooking area cover panel, so that the elevation feet can be attached to the cooking area at the desired locations, and the desired installation height of the cooking area cover panel on the cooking area can be achieved. This can also be achieved in principle with a cooking area cover panel that is smooth on the underside or with partial cover panels that are smooth on the underside. However, this is especially expedient to implement in combination with a cooking area cover panel which may optionally also be provided permanently with small spacer feet from the beginning. In the latter case, either the elevation feet may serve independently as support, or the spacer feet may be placed on the elevation feet.
In implementing suction cups as the connecting means, these suction cups may also be used as (low) spacer feet on the side working panel if the spacer feet which then function as elevation feet are designed to be easily removed from the suction cups.
Additional embodiments and refinements of the present invention are the object of the additional subordinate claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be explained in more detail with the aid of the drawing illustrating only one embodiment. The drawings show:
FIG. 1 a first embodiment with two partial cooking area cover panels of approximately the same size for a glass ceramic cooking area;
FIG. 2 another embodiment with partial cooking area cover panels of different sizes;
FIG. 3 an enlarged perspective view of a partial cooking area cover panel;
FIG. 4 a a first variant of a spacer foot provided with connecting means for a cooling area cover panel according to this invention;
FIG. 4 b a second variant of a spacer foot provided with connecting means for a cooling area cover panel according to this invention;
FIG. 4 c a third variant of a spacer foot provided with connecting means for a cooling area cover panel according to this invention;
FIG. 4 d a fourth variant of a spacer foot provided with connecting means for a cooling area cover panel according to this invention;
FIG. 5 a a first sample spacer foot of a first height for a cooking area cover panel according to this invention;
FIG. 5 b a second sample spacer foot of a second height for a cooking area cover panel according to this invention;
FIG. 5 c a third sample spacer foot of a third height for a cooking area cover panel according to this invention;
FIG. 6 a spacer foot that can be cut to different heights for another embodiment of a cooking area cover panel according to this invention;
FIG. 7 another embodiment of a cooking area cover panel according to this invention with a spacer foot and an elevation foot, shown in excerpts.
DETAILED DESCRIPTION OF THE INVENTION
The embodiment illustrated in FIG. 1 shows first a cooking area cover panel for a cooking area 1 which is installed in a kitchen working panel 6 in a known way. A cooking area cover panel 2 , 3 whose dimensions correspond to the dimensions of cooking area 1 is provided on the cooking area 1 . The cooking area cover panel 2 , 3 is composed of multiple partial cover panels 2 , 3 . The embodiment illustrated here, which is preferred, has two single partial cover panels 2 , 3 whose outside dimensions supplement each other to form the dimensions of the cooking area 1 . With a wider cooking area 1 with a width of 90 cm, for example, three partial cover panels 2 , 3 may also be arranged side by side. A larger number of partial cover panels 2 , 3 is also possible in principle.
A glass ceramic cooking area 1 is illustrated here, but this is not to be understood in a restrictive sense. The cook tops may also be metal cooking areas with individually inserted electric cooking plates or gas cooking areas with individual gas burners, for example. The teaching according to the present invention also relates to a particular design of a cooking area cover panel such that it can be used for different cooking areas 1 .
The advantages of multiple partial cover panels 2 , 3 as parts of an overall cooking area cover panel 2 , 3 are explained in the documents that form the basis of German Utility Model 298 13 303 U1, the prior art document mentioned above. Reference is herewith made to that utility model.
The embodiment illustrated in FIG. 1 shows two individual partial cover panels 2 , 3 which have the same outside dimensions. These two partial cover panels 2 , 3 can be stacked especially well. The embodiment illustrated in FIG. 2 has an alternative with two partial cover panels 2 , 3 which do not have the same outside dimensions.
The embodiments illustrated here show, as seen especially well in FIG. 3, that the partial cover panels 2 , 3 forming the cooking area cover panel 2 , 3 are provided with spacer feet 4 mounted on the underside in the ready-to-use condition. FIG. 3 shows a total of six such spacer feet 4 . The teaching of the present invention concerns the arrangement and design of these spacer feet 4 .
The figures also show cooking zones 5 of the glass ceramic cooking area 1 shown here, the working panel 6 and a cooking pot 7 placed on a cooking zone 5 in FIG. 2 as an example. FIG. 2 shows especially well how practically the partial cover panel 3 can be used on the working panel 6 , while the partial cover panel 2 can serve as a nearby working surface on the cooking area 1 next to the cooking pot 7 .
It is especially advantageous if the partial cover panels 2 , 3 are made of fracture-proof glass. It may be clear or provided with a decoration. Partial cover panels 2 , 3 made of hard, fracture-proof and scratch-proof glass meet all the requirements regarding ease of handling and hygiene in the kitchen. They are suitable for setting down hot pots and pans, and their scratch-proof and pore-free surface prevents bacteria from collecting and prevents odors from developing. The partial cover panels 2 , 3 can be cleaned well and form an excellent substrate as a working panel.
Materials other than fracture-resistant glass are fundamentally also possible for producing corresponding partial cover panels 2 , 3 for a cooking area 1 . In particular, heat-resistant laminates, molded plastics or glass ceramic may be used.
The spacer feet 4 are necessary for the cooking area cover panel 2 , 3 so that the cooking area cover panel 2 , 3 or its partial cover panels 2 , 3 do not come in contact with cooking area 1 or the corresponding electric cooking plates, gas burners and/or pot carriers, which can be very hot. The installed height of the spacer feet varies for the different cooking areas 1 (e.g., 25 mm for electric burners, 5 mm for glass ceramic cooking area, 40 mm for gas burners). The present invention takes this into account in that the spacer feet 4 are still separate from the cooking area cover panel 2 , 3 in the as-delivered or purchased condition. However, the spacer feet 4 are provided with connecting means 8 for later mounting on the cooking area cover panel 2 , 3 .
In particular, the spacer feet 4 can be made of a plastic that has the required heat resistance and which can be mounted well on the underside of the cooking area cover panel 2 , 3 . It is especially advisable for the spacer feet 4 to be made entirely or partially of a plastic with a surface having a high coefficient of friction, in particular a thermoplastic elastomer. As an alternative natural rubber is possible.
In particular, FIGS. 4 a , 5 a , 5 b , and 5 c and 6 show connecting means 8 on the spacer feet 4 which are designed as self-stick layers. The protective film is pulled away from the self-stick layer and the spacer foot 4 is pressed on the underside of the cooking area cover panel 2 , 3 and thus permanently attached there. In particular, reference is made in this regard to the applicants utility model patent application that was filed at the same time and relates to the matter of applying a protective film to the underside of the cooking area cover panel 2 , 3 .
FIG. 4 b shows an alternative which is characterized in that the connecting means 8 is designed as catch nubs on the spacer foot 4 . A measure must be provided on the cooking area cover panel 2 , 3 such that it has a corresponding catch opening 9 at the intended fastening spot for the spacer foot 4 . By pressing the catch nub into catch opening 9 , it is possible to achieve a permanent mounting of the spacer foot 4 on the cooking area cover panel 2 , 3 . This is illustrated in FIG. 4 b with cooking area cover panel 2 and its catch opening 9 , only a detail of which is shown.
An alternative also consists of providing the connecting means 8 as a threaded pin, optionally with a lock nut, and providing the cooking area cover panel 2 , 3 with a corresponding threaded socket 10 or a through-hole. FIG. 4 c shows this variant. If the cooking area cover panel 2 , 3 is made of fracture-proof glass, then a through-hole may instead be implemented as a threaded socket which is difficult to provide in it.
FIG. 4 d illustrates an embodiment which is characterized in that the connecting means 8 are designed as suction cups 11 . This also provides for the spacer foot 4 to be detachable from the suction cup 11 and therefore it has a catch opening 12 for a catch nub 13 of the suction cup 11 . The standing security is especially good here due to the fact that the spacer foot 4 is designed as an inverted cup shape or as a truncated conical shape. This alternative is especially advantageous with different cooking areas 1 with differently arranged and designed cooking zones 5 . The spacer feet 4 are simply attached to the cooking area 1 at the locations where this is an expedient arrangement with regard to the arrangement of the cooking zones 5 . The suction cups 11 are then snapped onto the spacer feet 4 . The suction cups 11 are moistened and then the corresponding partial cover panel 2 , 3 is pressed onto the respective suction cups 11 . Thus, the spacer feet 4 are automatically positioned in the correct locations.
If working with comparatively tall spacer feet 4 on working panel 6 which has a smaller height, the spacer feet 4 can easily be detached from the remaining suction cups 11 on the partial cover panel 2 , 3 , given a suitable design, and the suction cups 11 can then be used even with their catch nubs 13 as lower spacer feet on the working panel 6 . The “actual” spacer feet 4 then have the function of the elevation feet 14 to be explained below.
FIGS. 5 a , 5 b and 5 c show that for universal applicability for all types of cooking areas 1 , a cooking area cover panel 2 , 3 can be equipped with multiple sets of spacer feet 4 of different heights even in the as-delivered or purchased condition. As an alternative, it is of course also possible for the customer to order the proper set of spacer feet 4 for the cooking are cover panel 2 , 3 at the same time. If multiple sets of spacer feet 4 of different heights are provided for the different use cases from the beginning, then the customer can simply select the proper set of spacer feet 4 and attach them to the cooking area cover panel 2 , 3 .
FIG. 6 shows an alternative to the solution described above with multiple sets of spacer feet 4 of different heights, consisting of designing the spacer feet 4 with a height corresponding to the maximum possible installation height. The spacer feet 4 may then be cut to the desired height in the ready-to-use condition. One would then have, for example, the maximum installed height for a gas cooking area, but the spacer feet 4 can be cut to the minimum installed height for a glass ceramic cooking area if the respective customer has a glass ceramic cooking area. In the embodiment illustrated in FIG. 6 and discussed above, it is advisable for the spacer feet 4 to have cutting marks corresponding to the conventional installed heights. These may simply be visual marks, but they are preferably surface indentations or cuts that also serve as a guide for a suitable tool, so that a precise cut can be made.
Another alternative which is not illustrated in this drawing also consists of the fact that the spacer feet 4 are designed as multi-part plug-on or stick-on elements with a small individual height. This is opposite to the embodiment according to FIG. 6. A sufficiently large number of plug-on or stick-on elements, preferably similar, are provided prepackaged with the cooking area cover panel 2 , 3 , so that the required number of plug-on or stick-on elements can be assembled to achieve the required installed height of the spacer feet 4 for the given application.
In practice, it has been found that very high spacer feet 4 such as those which may be necessary for a gas cooking area 1 , for example, may be uncritical for covering the cooking area 1 per se, but they are not practical in handling if the cooking area cover panel 2 , 3 or the corresponding partial cover panels 2 , 3 are used next to the cooking area 1 on the kitchen working panel 6 . It is self-evident that a greater height of the spacer feet 4 contributes to their instability. The alternative of this invention as illustrated in FIG. 7 is to provide separate elevation feet 14 for the cooking area cover panel 2 , 3 , in which case the elevation feet 14 can be placed on the cooking area 1 and the desired installed height of the cooking area cover panel 2 , 3 in the cooking area 1 achieved by means of these elevation feet 14 . The elevation feet 14 of this alternative need not necessarily have spacer feet 4 on the cooking area cover panel 2 , 3 . However, they are especially expedient in combination with spacer feet 4 of a small height on the cooking area cover panel 2 , 3 . Thus, although the required installed height for the cooking area 1 is achieved, the (low) spacer feet 4 on the cooking area cover panel 2 , 3 nevertheless allow secure and stable working on the working panel 6 at the side.
In this case, because the spacer feet 4 have the lowest possible height, namely the height for a glass ceramic cooking area 1 , they may be permanently attached to the cooking area cover panel 2 , 3 from the very beginning, as is already known in the state of the art, which forms the starting point of the present invention. Only the elevation feet 14 are then purchased separately by the customer or are packaged with the cooking area cover panel 2 , 3 in the as-delivered or purchased condition.
The elevation feet 14 , one of which is indicated in FIG. 7, may be placed loosely on the cooking area 1 . This will more likely be the standard case. However, the elevation feet 14 may be attached permanently to the cooking area 1 , in particular by gluing them. Of course, this must be done with a connecting means suitable to tolerate the heating of the cooking area 1 .
Finally, FIG. 7 shows that in the embodiment illustrated here, the elevation feet ( 14 ) has a central opening or recess for mounting and lateral alignment of the spacer feet 4 . This may but need not be implemented in this way. The advantage of this arrangement is that the cooking area cover panel 2 , 3 or the corresponding partial cover panels 2 , 3 are aligned and secured at the sides and consequently cannot slip.
Moreover, in principle the same considerations apply to the elevation feet 14 as the spacer feet 4 , in particular with regard to multiple sets of elevation feet 14 , etc. of different heights.
FIG. 4 d shows that in the embodiment illustrated there, the connecting means 8 also have the function of a low spacer foot, and the spacer foot 4 accordingly forms the elevation foot in the terminology used previously. | A cooking area cover panel to be applied separately for a cooking area is made of a hard material and comprises a plurality of individual partial covering panels having an underside and a top side and spacer feet provided with connecting means for selectively mounting on the cooking area cover panel. The spacer feet are mountable to the underside of the cooking area cover panel in a ready-to-use condition, wherein the spacer feet are separate from the cooking area cover panel in a disassembled condition of the cooking area cover panel. | 5 |
FIELD OF THE INVENTION
The present invention relates generally to cellular wireless data communications networks, and more specifically to a method and apparatus relating to methods of handover for cellular radio systems.
BACKGROUND OF THE INVENTION
As is well known in the art, the concept of handover refers to the process of changing the server or set of servers that communicate payload data with a user equipment. Typically, each server serves a different area of wireless coverage, and a cellular radio base station may be equipped with several servers. The terms handover and handoff are generally used interchangeably in the art.
The process of handover has evolved between generations of cellular wireless; first and second generation systems employed what may be termed hard handover, in which data payload communication to a user was transferred from a single base station to another base station.
In third generation systems, such as UMTS release 99 using code division multiple access (CDMA), so-called soft handover is used, and involves several servers within an active set simultaneously transmitting the same payload data to a user equipment. The user equipment then combines the payload data using a combining algorithm; this is a robust system, in which the redundancy of having two or more base stations serving a user equipment has the effect that communication may be maintained even when communication between the user equipment and another server has failed due to shadowing, multipath fading, interference or other problems occurring in the transmission path. Thus, soft handover provides improved quality of service over hard handover. However, the simultaneous transmissions make demands on radio resource that could otherwise be used to transmit payload data.
In third generation evolutionary systems and fourth generation systems, such as HSPA (‘High Speed Packet Access’), and LTE (Long Term Evolution), handover again relates to the selection of a set of servers with which signalling is maintained, corresponding to the active set of a CDMA system, but in addition there is a process of selection of the best server within the set for data payload transfer, potentially on a packet-by-packet basis, a process known as best server selection and also known as re-pointing or fast server selection. Signalling is maintained between each user equipment and the set of servers but payload data is only sent between the best server and the user equipment, thus making efficient use of radio resource. However, it is none the less necessary to send duplicate data across the backhaul network to each server in the set in order that the data is available for selection should a given server be selected as best server. The disadvantage of sending duplicate data is that this places demands on backhaul resource.
The server within the set that provides the highest pilot signal power received at a user equipment over a measurement period is known as the primary server. A pilot signal is a component of a signal that is transmitted at a known amplitude; in the case of a CDMA, a pilot signal is typically a signal component that is transmitted with a scrambling code but not a Walsh spreading code. In the case of an orthogonal frequency division multiplexed (OFDM) signal, a pilot signal may comprise one or more subcarriers that are transmitted with predetermined amplitudes and phases at predetermined times and frequencies. Measuring the power of a pilot signal is thus a reliable way of determining a measure of the signal power, since variations due to modulation with unpredictable payload data are removed. The power of a pilot signal is however not the only possible measure of received signal power; for example, an average of a received signal strength indicator (RSSI) may be used to indicated received signal power. It should be understood that when reference is made to the power of a received signal, that power may be measured in terms of the power of a pilot signal or by other methods known in the art.
As user equipments move within a network between areas of coverage of different servers, the set and indeed the primary server will change. The network continually determines which servers should form the set for a given user equipment based, for example, on the received power of base station pilot signals as measured by the user equipment and reported to the network.
For example, FIG. 1 illustrates a user equipment 1 in communication with a set of servers 2 a and 2 b but not in communication with a third server 2 c . The servers 2 a , 2 b , 2 c are connected to a radio network controller 3 via a telecommunications network 5 . Typically the radio network controller controls the handover process. Thresholds are typically set by network operators to determine when to add or drop a server from the set for a user equipment in dependence on the measured received signal powers. Such thresholds are typically set in terms of received power of the server signal relative to the received power of the primary server signal. This may be expressed as a window of powers between the threshold power and the received power of the signal originating from the primary server, that is to say a power level range relative to the power of the signal associated with the primary server. A server may be added if its received power falls within the window, or above the threshold. The difference between the threshold and the received power of the primary server signal may be termed a margin. The margin is typically expressed in decibel (dB) terms; a difference in decibel values corresponds to a ratio of power levels expressed in linear terms.
FIG. 2 illustrates an example of a physical layout of servers 2 a , 2 b and 2 c , their respective areas of coverage 4 a , 4 b and 4 c , and the trajectory 6 of a user equipment moving relative to the servers.
FIG. 3 illustrates how the received power from the respective servers at a user equipment varies as the user equipment moves along the trajectory 6 ; received powers from servers 2 a , 2 b and 2 c are indicated by curves 8 a , 8 b and 8 b respectively. A threshold 10 is shown and the difference 12 between the threshold and the primary server power (the primary server power being shown by the sections of 8 a and 8 b shown as bold lines) is the margin, while the power range within the difference 12 is the window as previously mentioned. In the example of FIG. 3 a single threshold is used for determining the adding or dropping process. It can be seen that as the user equipment moves from point A via B to C that server 2 b will be added to an active set at position 9 , as the power 8 b exceeds the threshold 10 . At point 11 , server 2 c will also be added, and at point 13 server 2 a , assumed already a member of the set, will be dropped, followed by the dropping of server 2 b at position 15 .
In practice, different add and drop thresholds may be selected (relative to the primary server power), so that hysteresis is provided meaning that servers are not repeatedly being added or dropped to the active set as they fall above or below a single threshold. In the case of CDMA systems, typical operator settings would have the effect of adding to an active set any server which has a pilot power as measured by the user equipment of 4 dB lower than the primary server pilot power or better, and to drop from the active set any server which has a pilot power as measured by the user equipment of 8 dB lower than the primary server pilot power or worse.
Practical systems differ from the simple situation illustrated by FIG. 3 in that there are time constants involved in the process of adding or dropping servers. Typically, when a received signal from a server exceeds a threshold, a timer is started and if the threshold is still exceeded when the timer times out, then the process of adding the server to a set, typically an active set, takes place. Similarly, when a received signal from a server falls below a threshold, a timer is started and if the signal still falls below the threshold when the timer times out, then the process of dropping the server from a set can take place. The thresholds and the times between the start and end of a count, that is to say when the timer counts out, need not be the same for adding as for dropping a server from a set. This time delay may be imposed to prevent the adding or dropping of servers due to transitory changes in signal powers.
In addition to the time taken to decide to add or drop a server, there is also a period of time required to implement the adding or dropping process. Taking the example of adding a server to an active set in a CDMA system, the process typically involves signalling from the user equipment to one or more servers and from there to a radio network controller to indicate that the threshold has been passed to the required certainty. The radio network controller will then typically make a decision as to whether or not to add a server to the active set on the basis, for example, of available resources. A message will then need to be sent to the existing members of the active set of servers serving the user equipment indicating to the user equipment that it should expect to receive signals from the server joining the active set, communicating amongst other data the Walsh code that new server will be using. This message is then required to be passed on from the members of the existing active set, or from a sub-set of them, that may include only one server, to the user equipment. If the signal received from all of the existing active set falls below a minimum level, then communication to the user equipment may not be possible. The generation, sending and receiving of the above messages takes time, and if the communication from the existing active set is lost before the user equipment receives the information that a new member of the active set has been added, then the handover process may fail and any call taking place may be dropped.
The detail of the messaging may vary between systems, but typically there is a time delay between the crossing of a power threshold and communication being established between a user equipment and a server newly added to a set.
If a greater number of servers is maintained in the active set, for example by setting a lower threshold for adding a server to the active set, there may be a greater probability that communication may be maintained with at least one server, and so there may be a lower rate of dropped calls. However, as has been mentioned, this is at the expense of network capacity.
Typically, a network operator is able to balance the need for efficient utilization of network capacity (particularly on the downlink) and quality of service (for example probability of dropped calls) through network planning, including geographical cell planning, server selection, antenna orientation, and through choice of power thresholds or windows for adding and dropping servers from an active set. So it can be seen that whilst it is undesirable to have too many servers in the active set for a given user equipment, too few can result in quality of service issues.
One problem with the currently implemented methods described above is that they tend to be network-wide; that is to say that thresholds or windows for adding or dropping servers from active sets are specified across an entire network. These network-wide thresholds or windows do not take into account the differences in the radio environment that individual user equipments may be experiencing and are thus likely to be suboptimal for any given region of the network.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention, there is provided a method of handover in a cellular radio communications network comprising a plurality of servers, one or more of the servers being in a set of servers for serving a user equipment and the user equipment being capable of receiving signal power from each of the plurality of servers, the method comprising:
measuring the signal power received at the user equipment from at least one server of the plurality of servers;
evaluating a factor indicative of the motion of the user equipment;
determining a threshold of signal power for the signal from the at least one server in dependence on said factor; and
determining whether or not the at least one server should be added to or dropped from the set on the basis of a comparison of the measured signal power received from the at least one server with said threshold.
A benefit of determining the threshold on the basis of a factor indicative of the motion of the user equipment is that, in a network comprising a plurality of user equipments moving at different speeds, the average number of servers held in sets of servers for serving the user equipment is reduced. This is because faster moving user equipments require a lower threshold than slower moving user equipments, and so if—per conventional methods—the same threshold is used regardless of the speed of a user equipment, an unnecessarily high average number of servers are held in sets for serving slow moving user equipments. A reduction in the average number of servers held in sets of servers for serving the user equipment has the benefit of reducing data traffic loading in a backhaul network, since the need to send duplicated data to each member of sets of servers is reduced.
Preferably, the threshold is determined in dependence on a margin and the evaluated power from the primary server; the benefit of this is that, in code division multiple access systems, since the primary server appears as a source of interference, the threshold is in effect set in terms of carrier to interference ratio which is a good indicator of signal quality. In systems using best server selection, setting the threshold in dependence on a margin from a primary server, also known as the best server, is a convenient method to control the number of servers admitted to a set of servers for serving the user equipment.
Conveniently, the set of servers is an active set of servers in a cellular radio communications network using code division multiple access. The benefit of a reduction in the average number of servers held in active sets of servers is an increase in the data payload capacity a network, since the radio resource is used more efficiently because the proportion of servers sending duplicate data is reduced.
Conveniently, the threshold is determined in dependence on a predetermined threshold and an adjustment component that is dependent on the motion of the user equipment. The benefit is that an adjustment component may be calculated independently of knowledge of a predetermined threshold.
Preferably, the factor indicative of motion of the user equipment is determined in dependence on the Doppler spread of a signal received from the user equipment at one or more servers. This has the benefit that motion of the user equipment can be determined on the basis of a single frequency analysis operation that may require samples of the received signal to be taken over a shorter time period than would be required to deduce the motion of the equipment from a succession of measurements of signal level. A further advantage is that Doppler spread in a typical environment that is rich in multipath sources gives an indication of speed that takes into account both radial and tangential components of the motion of a user equipments.
In one arrangement, the Doppler spread is determined by transforming a pilot signal to the frequency domain and quantifying a range of frequencies comprising the transformed signal. A benefit of this is that a pilot signal is transmitted with a known frequency composition, so that Doppler spread may be accurately quantified.
Conveniently, the factor indicative of motion of the user equipment is determined from the Doppler spread of a signal received at the user equipment from a server. A benefit of this is that the threshold may be determined within the user equipment without the need to communicate with a radio network controller.
In one arrangement, the factor indicative of motion of the user equipment is determined from data generated by a satellite navigation receiver at the user equipment. A benefit of this is that the threshold may be determined within the user equipment without the need to signal to a radio network controller.
Advantageously, the factor indicative of motion of the user equipment may be determined from the rate of change of the strength of the signal received at at least one server from the user equipment. A benefit of this is that the component of the direction of movement of the user equipment towards or away from the user equipment may be determined in addition to the speed.
Conveniently, the factor indicative of motion of the user equipment may be determined from the rate of change of the strength of the signal received from at least one server at the user equipment. A benefit of this is that the component of the direction of movement of the user equipment towards or away from a server may be determined in addition to the speed, without the need to signal to a radio network controller.
Preferably, the factor indicative of motion of the user equipment comprises an indication of the direction of motion of the user equipment and the threshold applicable for a given server is determined to be lower if the direction of motion is towards the given server than if the direction of motion is away from the given server. A benefit of this is that the average number of servers held in sets of servers for serving user equipment may be reduced, in a network comprising a plurality of user equipments moving in different directions.
In one arrangement, it is determined whether or not a given server should be added to or dropped from a set on the basis of a quality factor assigned to the given server. Conveniently, the quality factor is indicative of the expected rate of change of the strength of a signal received from the at least one server said by a user equipment in an area of coverage of the at least one server. Preferably, the quality factor is indicative of a history of dropped calls associated with the at least one server. The benefit is that higher thresholds may be set for servers with a lower expected rate of change of signal strength or a low historical probability of dropped calls than for servers with a higher expected rate of change of signal strength or a higher historical probability of dropped calls; as a result the average number of servers held in sets of servers for serving user equipment in a network comprising servers with a variety of assigned quality factors can be reduced.
Apparatus, such as base stations, base station controllers (or radio network controllers) and other apparatuses arranged to perform the above methods are also provided. Apparatuses and methods combining the two aspects of the present invention are also provided.
Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the topology of a network according to an embodiment of the invention;
FIG. 2 is a schematic diagram showing an example of an arrangement of servers and a trajectory of a user equipment for use in describing the operation of an embodiment of the invention;
FIG. 3 is a schematic diagram showing received power on a logarithmic scale at a user equipment as a function of distance along the trajectory of FIG. 2 and showing a threshold for adding and dropping servers to a set according to a conventional method;
FIG. 4 is a schematic diagram showing received power on a logarithmic scale at a user equipment as a function of distance along the trajectory of FIG. 2 and showing thresholds for adding and dropping servers to a set according to an embodiment of the invention;
FIG. 5 is a schematic diagram showing as a function of time, received power on a logarithmic scale at a slow moving user equipment moving along the trajectory of FIG. 2 and showing a first threshold for admission of servers to an active set for a slow moving user equipment according to an embodiment of the invention;
FIG. 6 is a schematic diagram illustrating the problems that would be experienced if a fast moving user were to operate using the first threshold of FIG. 5 ;
FIG. 7 is a schematic diagram showing as a function of time, received power on a logarithmic scale at a fast moving user equipment moving along the trajectory of FIG. 2 and showing a second threshold for admission of servers to a set according to an embodiment of the invention;
FIG. 8 is a schematic diagram showing an example of a trajectory of a user equipment in an environment experiencing blocking as an illustration of an embodiment of the invention;
FIG. 9 is a schematic diagram showing, as a function of time, received power as measured by E c /I 0 on a logarithmic scale at a user equipment moving along the trajectory of FIG. 8 and showing a lower threshold for admission of servers to a set in an environment experiencing blocking according to an embodiment of the invention;
FIG. 10 is a schematic diagram showing an example of a trajectory of a user equipment across a cellular system as an illustration of an embodiment of the invention;
FIG. 11 is a diagram showing, as a function of time, received power on a logarithmic scale at a user equipment moving along the trajectory of FIG. 10 and showing a threshold for admission of servers to an active set specific to a server according to an embodiment of the invention; and
FIG. 12 is a diagram showing a typical logical flow of messages in a CDMA system implemented as an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In general, the present invention is directed to methods and apparatus that improve handover in cellular radio systems, in particular improving network capacity for networks involving a mix of fast and slow moving, including static, user equipments.
For clarity, the methods and apparatus are described mainly in the context of a network operating to a CDMA standard, and a set of servers will be referred to as an active set, but it will be appreciated that this is by way of example and that the methods and apparatus described are not limited to this example. In particular, the methods and apparatus are suited to operating within a high speed packet data system such as HSPA, LTE, or Wimax. In a system employing best server selection, also known as fast server selection or pointing, a set of servers is maintained from which a best server can be selected, potentially on a packet-by-packet or frame-by-frame basis. This set is analogous to the active set of a CDMA, and aspects of the invention can equally be applied to such a set as to an active set in a CDMA system.
As already mentioned, FIG. 3 illustrates the conventional use of a threshold 10 in a cellular wireless system as has already been described with reference to FIGS. 1 and 2 , for determining whether to add or drop a server to or from an active set of servers.
FIG. 4 illustrates an embodiment of the invention applied to the network topology of FIG. 1 for a user equipment moving through the network with the trajectory 6 of FIG. 2 . It can be seen in FIG. 4 that two different thresholds are shown; the higher of these, 10 b , is applicable to a slow moving or static user equipment, and the lower, 10 a , is applicable to a fast moving user equipment.
By comparison with FIG. 3 , in which the vertical scale is intended to be similar, it can be seen that the threshold 10 b for a slow moving or static equipment has been set at a higher level than would be used for a conventional network-wide threshold level; according to embodiments of the invention, the threshold may be set according to a factor indicative of the motion of the user equipment, so for a slow moving or static user equipment, the threshold may be set at a higher level than for fast moving equipment. That is to say that the margin 12 between the threshold and the primary server is reduced and so the window for the admission of servers to an active set is reduced. The benefit of the variable threshold will now be described.
The problem with a conventional method of setting a threshold, in which a network-wide threshold is set, is that the threshold has to be set to meet the needs of most demanding scenario; generally this will be a fast-moving user equipment and/or a server in an environment with significant obstructions to the radio propagation path, such as urban “street canyons” between tall buildings. In such demanding scenarios, it is beneficial to hold a higher number of servers in an active set, since this reduces the chances that all of the set will be lost due to rapid changes in the radio propagation due to the motion of the user equipment and blocking by obstructions. In addition, it is advantageous to keep at least a minimum number of servers in an active set, in order to maintain signal quality by diversity combination. What is more, it is advantageous to admit a new server to the active set early on in such demanding conditions, since, as has been already mentioned, it will take a finite amount of time to establish the new server in the active set and communicate to the user equipment to instruct it to receive the signal from the new server. For example, in CDMA systems the user terminal needs to be instructed as to which spreading, or Walsh, code is to be received from the new server. The sooner the new server is admitted to the active set, the less the chance that communication with the user equipment from the existing active set will be lost before the new server can be received, a situation that may result in a dropped call.
However, in a mobile network, it is generally a minority of user equipments that are fast moving. In fact, in many cases the majority of users are moving at less than 1 m/s, and many of these are static.
To certain extent the range of speeds of user equipments connected to a base station depends on the location of the base station at which the server is located; servers close to a road with fast-moving traffic or close to high speed train lines may be expected to show quickly changing signal levels. Even so, in the majority of cases, there is a predominance of base stations at which the majority of users are slow moving or static, and at which the signals level received by a user equipment tend to vary slowly in most cases due to a variety of factors, including the speed of the motion of the user equipments and the multipath and blocking environment in terms of radio frequency propagation.
Conventionally the add and drop thresholds for a network will be set on the basis of drive testing, in which statistical information is gathered by carrying a user equipment in a vehicle and moving about within the network at various speeds and locations, logging the performance of the link to the user equipment and the network, including quality of service metrics such as dropped call rate. Thresholds are set as a trade off between quality of service and network capacity, as has been already mentioned, on a network-wide basis.
However, it has been estimated that if, as an embodiment of the present invention, a higher threshold is used for slow moving or static user equipments than for fast moving user equipments, a significant increase in network capacity can be achieved. For example, it has been shown that a capacity increase of approximately 20% may be expected compared with a network using a uniformly applied add and drop threshold set with a margin of 6 dB compared to the primary server. It is to be noted that the results obtained using a using an add margin of 4 dB and a drop margin of 8 dB are similar to those obtained using a margin of 6 dB for both add and drop thresholds, in terms or relative capacity.
The dependence of the threshold on speed may be a continuous or stepped function, so that there may be for example be many values of threshold to be chosen amongst as a function of measured speed range. A particularly useful case is the application of two values of threshold according to a classification of user equipment speed as slow or fast based on an approximate speed threshold. For example, a margin of 3 dB may be applied relating to user equipment speeds below approximately 15 m/s and 6 dB for speeds above this, giving an improvement over a fixed threshold of approximately 15% in capacity compared to a system with a fixed margin of 6 dB.
For comparison, it has been shown that if a threshold is continuously variable (subject to a minimum margin of 1 dB), an increase of approximately 22% in system capacity may be expected compared to a system with a fixed margin of 6 dB.
Returning to FIG. 4 , it should be noted that for the sake of clarity the operation of the network is illustrated with the simplifying assumption that the same threshold is used for adding as for dropping a server; that is to say no hysteresis is shown. In practice, and as already mentioned, it is generally beneficial to use a system with hysteresis, that is to say a difference between thresholds for adding as opposed to dropping a server, with the benefit of reduced requirement for signalling since the incidence of adding and dropping is reduced. In such a system, the thresholds illustrated in FIGS. 3 and 4 may be considered as add thresholds, and the associated drop thresholds would be lower by an appropriate amount; typically drop thresholds are lower than add thresholds by approximately 3 to 6 dB, but other values may be used as appropriate to the system in question.
In FIG. 4 it can be seen that movement of a user equipment along the trajectory 6 of FIG. 2 is represented by a change in position on the horizontal axis of FIG. 4 through points A, B and C. The received powers from servers 2 a , 2 b and 2 c are represented by curves 8 a , 8 b and 8 c respectively.
Taking firstly the case of a fast moving user equipment, it is assumed that at point A on the horizontal axis, server 2 a is already included in the active set of servers. At position 9 a , the power received from server 2 b , represented by curve 8 b crosses threshold 10 a and (neglecting effects related to time constants), server 2 b is added to the active set. At position 15 a , however, the received power from server 2 b falls below the threshold 10 a (on the assumption of a zero hysteresis system) and so the server 2 b is dropped from the active set. It will therefore be appreciated that the server 2 b is held within the active set over the region 14 a.
Now considering the case of a slow moving or static user equipment, it is again assumed that at point A on the horizontal axis, server 2 a is already included in the active set of servers. At position 9 b , the power received from server 2 b , represented by curve 8 b crosses threshold 10 b and server 2 b is added to the active set. At position 15 b , the received power from server 2 b falls below the threshold 10 b and so the server 2 b is dropped from the active set. It can be seen that this case, the server 2 b is held within the active set over the region 14 b which is smaller than 14 a . The server 2 b is thus held in the active set over a smaller region of the network for a slow moving user equipment than for a fast moving user equipment. Clearly, the other servers will similarly be held in the active set over a smaller region of the network for a slow moving user equipment than for a faster moving user equipment. So, it can be seen that providing a higher threshold for slow moving or static user equipments has the effect that over the network taken as a whole, fewer servers will be held in active sets than would be the case if a universal threshold were applied at the level applicable for a fast moving user equipment.
FIGS. 5 , 6 and 7 illustrate an embodiment of the invention applied to the network topology of FIG. 1 for a user equipment moving through the network with the trajectory 6 of FIG. 2 , with the horizontal scale representing time rather than distance as was the case in FIGS. 3 and 4 . FIG. 5 illustrates the case of slow moving user equipment and FIGS. 6 and 7 illustrate the case of a faster moving user equipment. For the purposes of this illustration, a slow moving user equipment may, for example, have a speed of less than 10 m/s whereas a faster moving user equipment may have a speed of greater than 10 m/s. It should be noted that the rate of change of signal strength depends on other factors than the speed of the user equipment, such as the distance between base stations and the radio propagation conditions, so that the value of 10 m/s quoted in this illustration is simply an example.
FIG. 5 shows the variation of power as a function of time 8 a , 8 b , 8 c from each of respective servers 2 a , 2 b and 2 c . In the case of FIGS. 5 , 6 and 7 the threshold 10 is a threshold for the addition of a server to an active set. A similar threshold (not shown in this case), that may be at the same or a different level, exists for dropping a server from the active set.
The period of time 16 required to add a new server can be seen from FIG. 5 : the threshold 10 is crossed by the received power 8 c from server 2 c at time 18 . After the time period 16 , server 2 c is admitted to the active set. However, there will be a received signal level 17 , at which server 2 a , which is already assumed to be in the active set, will no longer to communicate with the user equipment; this occurs at time 20 in FIG. 5 . It can be seen that the period 16 for adding server 2 c ends before communication is lost with server 2 a . On the assumption that server 2 b has been added to the active set ahead of server 2 c , it can be seen that during the handover period from server 2 a to server 2 c , at least two servers are maintained within the active set, which is beneficial in terms of reducing the probability of dropped calls.
It should be understood that in practice the received signal level 17 will depend on the interference and noise environment, in which signals from other equipment may considered as interference, and so the level 17 will typically not be a constant received power level.
Considering now FIG. 6 , this illustrates what would happen if the same threshold were to be used for a fast moving user equipment as for a slow moving user equipment. It can be seen that the period 16 for adding server 2 c ends after communication is lost with server 2 a . As a result, the number of servers maintained within the active set falls to one in the handover period, risking dropped calls.
A solution according to an embodiment of the invention is shown in FIG. 7 . The use of a lower threshold 10 allows the start of the admission process of servers to the active set earlier than would be the case with a higher threshold, so that the time 18 occurs earlier than was the case in FIG. 6 . As a result, the period 16 for adding server 2 c ends before communication is lost with server 2 a , with the beneficial result that at least two servers are maintained within the active set in the handover period.
The period 16 for adding server may be quite significant; in some systems such as UMTS it may be as long as 500 ms.
FIG. 8 shows a trajectory 6 of a user equipment through an environment with significant blocking of radio frequency propagation, due to obstructions 7 a , 7 b , 7 c , 7 d such as buildings. Initially the user equipment has a line of sight to server 2 a and server 2 b is obstructed and on turning the corner as shown a line of sight becomes available to server 2 b but server 2 a is obstructed. The transition between these two states may be rapid. When a server is obstructed, some signal may still be received due to multipath, but this is typically quite variable and may be at a low level.
FIG. 9 illustrates the operation of an embodiment of the invention for a user equipment moving along the trajectory of FIG. 8 . The environment may be harsh as shown by a history of dropped calls due to the obstructions, and so a lower threshold 10 b may be imposed for servers 2 a and 2 b than the threshold 10 a used for servers in a benign environment with a history of a better quality of service, for example as measured by the rate of dropped calls. The dependency of threshold on speed of the user equipment may differ for a server in a harsh rather than a benign environment. For example, a lower threshold 10 b may be imposed for moving equipments at this server than for user equipments moving at the same speed at servers with a more benign environment; the rapid transitions between servers may also occur in the case of a relatively slow moving user equipment turning a corner close in to a building. However, the case may be different for user equipments that are static; these may not need a lower threshold than would be imposed for a static user equipment at another server, since for these user equipments the rate of change of signal strength may be no greater than that expected for other servers in a supposedly more benign environment.
It can be seen from the curves 8 a , 8 b representing the received powers from servers 2 a and 2 b respectively that the use of a lower threshold 10 b allows the period 16 a required for the addition of server 8 b to the active set to expire before communication is lost with server 2 a at time 20 when the signal level falls below an acceptable level. For this to happen, the threshold 10 b , in particular the add threshold, will typically be set at a low enough level that a server can be added on the basis of signals received due to multipath when the line of sight is heavily obstructed. As will be apparent, the benefit is statistical, since it will not always be possible to achieve handover in these circumstances if obstructions result in very deep fades.
By contrast, a higher threshold 10 a , that may be suitable for use in more benign environments, would not allow time to add server 2 b before server 2 a drops out, since time period 16 b would expire after time 20 .
As shown in FIG. 9 , a threshold may be set in terms of a measure known as E c /I 0 , rather than simply received power. The use of this measure is however not limited to the case illustrated by FIG. 9 ; it could equally well be applied to any example of the use of a threshold. E c /I 0 is the power of a respective pilot relative to the total power received.
For the case of a threshold 10 expressed as margin below a primary server level, it makes no difference whether the received power of the server in question and the primary server is expressed as simply the power of a pilot or as E c /I 0 , since the margin will be the same in dB terms. The ratio of the E c /I 0 value of a given server to the E c /I 0 value of the primary server is thus simply the ratio of the respective pilot powers, since the I 0 terms cancel. Hence, the vertical scales of FIGS. 3-7 and 11 could equivalently be labelled E c /I 0 .
However, as illustrated by FIG. 9 , a threshold for adding or dropping servers may alternatively be set as an absolute value of E c /I 0 , rather than a level relative to the received power of a primary server. In many cases in practice the primary server dominates the value of I 0 and so the effect is little different from the case where relative values are used, except for a constant offset value. Of course, different absolute threshold levels may be used for adding than for dropping servers from a set, similarly to the case for relative levels. An absolute threshold level as described may be applied to any situation in which a threshold relative to the received power of a primary server is applicable. The advantage of the use of an absolute value of E c /I 0 to set a threshold is that in some cases this value may be more readily available within a user equipment than the relative power levels of a primary server and the server in question, since the total power received may be easier to measure than the power of a pilot of a primary server.
FIG. 10 shows a trajectory 6 of a user equipment across a cellular network, comprising base stations at which are located servers 2 a , 2 b , 2 c , 2 d serving respective areas of coverage in sectors 4 a , 4 b , 4 c and 4 d.
FIG. 11 shows the variation of received power 8 a , 8 b , 8 c , 8 d received from servers 2 a , 2 b , 2 c and 2 d respectively at a user equipment moving along the trajectory 6 of FIG. 10 .
FIG. 11 illustrates that in an embodiment of the invention a threshold for the adding or dropping of a server to or from the active set for serving a user equipment may be set according to the motion of the user equipment with respect to the server. For example, as illustrated here, a lower threshold 10 b may be set for the adding a server to the active set if, as is the case of server 2 d , it is in the projected path of the user equipment. By contrast, server 2 c , that is not in the projected path of the user equipment may be given a threshold 10 b that is higher than 10 a . Hence the server 2 c is unlikely to be added to the active set since in the example of FIG. 11 the received power 8 c only fleetingly exceeds threshold 10 b at time 18 b and this is unlikely to trigger the addition to the active set as previously discussed due to the need to stay above the threshold for the duration of a timer period By contrast, the power 8 d of server 2 d , that is in the projected path, exceeds threshold 10 a at time 18 a and so it is added to the active set earlier than would have been the case had the higher threshold 10 b been applied. The benefit is that the active set is restricted to candidate servers with a good prospect of remaining in communication with the user equipment which improves the previously discussed capacity/quality of service trade off. So, the direction of travel of the user equipment may be taken into account in selecting the server for inclusion in the active set, such that those servers lying ahead of the moving user equipment may be preferentially included and those lying behind the user equipment preferentially excluded, despite their absolute or relative power levels.
Thus, a server with a positive or highly positive rate of change of power level as measured by the user equipment may be favoured for adding to an active set for that user equipment whereas a server with a negative or highly negative rate of change of power level as measured by the user equipment may be favoured for dropping from an active set for that user equipment. This may be so even though power levels of the two servers may be equal. In this manner, not only is the absolute or relative power level used to determine whether to add or drop a server from the active set, but also the rate of change of power level and, in particular, the sign of the rate of change of power level. Thus, for a user equipment moving away from a server, a negative rate of change of received power level would favour dropping that server, whereas for a user equipment moving towards a server, a positive rate of change of received power level would favour adding that server. By determining the members of an active set not only in dependence on the absolute or relative power levels, but also in dependence on the rate of change of power levels, the speed and direction of the user equipment may be indirectly taken into account, thereby enabling selection of servers towards which the user equipment may be heading for inclusion in the active set.
The Doppler spread of the uplink signal as received at a server from the user equipment is one possible way to estimate the speed of the user equipment. The Doppler spread can be defined as the maximum difference in frequency between different scattered components of the user equipments' transmission, that is the maximum difference in Doppler shifts between the different scattered components. Some scattered components may increase in frequency due to the motion of the user equipment while other components decrease in frequency according to whether the propagation path of respective scattered components is reduced or increased in length by the motion. This frequency difference can be measured, for example, by carrying out a long-term fast Fourier transform (FFT) of a train of pilot signals from the user equipment, and calculating the maximum frequency difference between FFT bins of significant power (i.e. of a power above the noise and interference). This Doppler spread value is directly proportional to the mobile's speed, and is inversely proportional to the carrier wavelength. This technique works most effectively within a rich scattering propagation environment, but this is in any event likely to be the case for most scenarios of practical interest.
Alternatively, the Doppler spread of signals received from one or more servers by the user equipment may be measured.
If the user equipment is equipped with a satellite navigation receiver, the motion of the user equipment in terms of speed and direction may be determined by the satellite navigation system and the determined values may be used for the calculation of a threshold for the adding or dropping of servers.
The determination of a threshold for adding or dropping servers may typically be carried out at a radio network controller. The radio network controller receives a factor indicative of the motion of the user equipment; this may be a message from the user equipment determined from measurements at the user equipment relating to rate of change of signal powers received from one or more servers, to Doppler spread, or to data derived from a satellite navigation system. Alternatively, the message may originate from a server, relating to the rate of change of a signal powers received from the user equipment and/or to Doppler spread.
The threshold may be determined at the radio controller on the basis of the factor or factors indicative of the motion of the user equipment and other factors as discussed. A message is then sent to the user equipment indicating the determined threshold and the user equipment reports to the radio controller if the threshold is exceeded (in the case of an add threshold) or if the signal falls below the threshold (in the case of a drop threshold). The add and drop threshold may be different, and may be sent separately, or alternatively one may be derived from the other at the user equipment. The controller determines whether or not a server should be added or dropped from a set on the basis of the report from the user equipment.
FIG. 12 shows typical signalling in a CDMA system implemented as an embodiment of the invention. At step S 12 . 1 UE 1 determines a factor indicative of motion (FIM) as previously discussed, for example on the basis of Doppler spread of received signals. A message 21 is then sent to the radio network controller 3 to convey the FIM at step S 12 . 3 . The radio network controller 3 then determines a threshold applicable to at least one server in dependence on the FIM message 21 (step S 12 . 5 ). The radio network controller then sends a message 22 to the user equipment conveying the determined threshold, which may be an add threshold T_ADD or a drop threshold, T_DROP, as shown at step S 12 . 7 . As discussed, a single threshold value may be used as both the add and drop threshold. At step S 12 . 9 the user equipment 1 then compares a measure of received power of at least one server with the determined threshold. If the add threshold is determined to be exceeded to an acceptable degree of certainty or if the received power is determined to be below the drop threshold to an acceptable degree of certainty then a soft handover request message (SHOR) 23 is sent from the user equipment to the radio network controller, as shown at step S 12 . 11 . This message indicates that a threshold has been crossed and requests that a server be added or dropped. The radio network controller 3 determines (step S 12 . 13 ) whether or not to add or drop the at least one server from the active set serving the user equipment 1 in dependence on the received soft handover request message 23 and on the availability of capacity at the at least one server. If it is decided to add or drop a server from the active set, this information is conveyed to the user equipment 1 by means of a server allocation message 24 (step S 12 . 15 ). The server allocation message indicates to the user equipment that it should expect to receive signals from the server joining the active set, communicating amongst other data the Walsh code that new server will be using. In a variant of the embodiment illustrated by FIG. 12 , factors indicating motion of the user equipment may be communicated from at least one of a plurality of servers 2 a , 2 b , 2 c to the radio network controller 3 . As previously discussed, the factors indicative of motion may be measures of Doppler spread of signals received from the user equipment or may be measures of the rate of change of signal strength received from the user equipment.
In a variant, the threshold may be determined at the user equipment 1 itself, on the basis of a factor indicative of the motion of the user equipment. In this case, the user equipment 1 sends a message 23 as before indicating to the radio network controller that the threshold has been exceeded by the signal received from a given server or that the signal has fallen below the threshold; again, there may be separate thresholds for adding as opposed to dropping servers.
At the expense of a potentially greater signalling overhead, it is also possible for the user equipment 1 to send regular indications of received signal strength to the radio network controller and for the comparison of these indications with the determined threshold to be carried out at the radio network controller rather than at the user equipment.
The above embodiments are to be understood as illustrative examples of the invention. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims. | In a cellular wireless system, power thresholds used for determining whether or not to add or drop servers held in a set of servers, such as an active set, for serving a user equipment are determined on the basis of the motion of the respective user equipment. A lower threshold may be used with respect to the adding or dropping of a given server to or from a set of servers for serving a fast moving user equipment than would be used for the same server with respect to its adding or dropping to or from a set of servers for serving a slow moving user equipment, while maintaining a given quality of service. As a result, the average number of servers held in sets is reduced in a typical network that comprises a plurality of user equipments moving at different speeds, compared to a situation in which the threshold is set irrespective of the motion of a user equipment. A reduction in the average number of servers held in sets of servers for serving the user equipment has the benefit of reducing data traffic loading in a backhaul network, since the need to send duplicated data to each member of sets of servers is reduced and/or increasing network capacity, since the radio resource is used more efficiently because the proportion of servers sending duplicate data is reduced. | 7 |
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