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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application PCT/NZ2007/000123, filed on May 22, 2007, which is incorporated by reference herein in its entirety. This application entered the National Phase in the U.S. on Nov. 21, 2008 as application Ser. No. 12/302,009.
FIELD OF THE INVENTION
[0002] The present invention relates to a laminate material and the method by which it is produced. More particularly but not exclusively it relates to a laminate material having one or more internal layers of polyester resin, and its method of preparation and shaping.
BACKGROUND OF THE INVENTION
[0003] In one aspect the invention relates to the technology of building materials. Glass is a very common such material. Although it has a number of advantages, transparency being an obvious one, it has a number of disadvantages. Glass is heavy, breakable and can be difficult to manufacture and to form. The problems associated with glass include the weight, lack of insulating and sound proofing properties.
[0004] We propose the use of an acrylic. Many variations and types are used, mainly in signage, walkways building canopies and skylights, for example. It has medium to high impact resistance, and has good resistance to scratching. However it is still inferior to glass in a number of areas. Greater thickness is required over certain dimensions and spans in comparison to glass.
[0005] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention, as it existed before the priority date.
[0006] It is an object of the present invention to provide a laminate material of self-supporting character and preferably having one or more superior properties over glass, particularly when used as a construction or manufacturing material.
[0007] Additionally or alternatively it is an object of the present invention to provide a laminate material, which can be shaped or formed.
[0008] Additionally or alternatively it is an object of the present invention to provide a novel method of preparing a laminate material.
[0009] Additionally or alternatively it is an object of the present invention to provide a laminate material that at least provides the public with a useful choice.
[0010] Other objects of the invention may become apparent from the following description, which is given by way of example only.
SUMMARY OF THE INVENTION
[0011] In an aspect the invention consists in a self supporting curved laminate product resulting from curving of a planar precursor,
[0012] wherein the planar precursor is a self supporting laminate of two sheets of an acrylic thermoplastic, or of sheets including an acrylic thermoplastic, spaced by, but attaching to, an interposed thermoset polyester system,
[0013] and wherein curving has involved heating of the laminate sufficient to allow its curving without any substantial degradation of the lamination or its component layers.
[0014] Preferably said heating has been into the range of from 105° C. to 120° C.
[0015] Preferably one or both sheets is of an acrylic plastic or is at least primarily acrylic plastic.
[0016] Preferably said polyester system has been prepared at least in part from (A) carboxylic acid(s) or dicarboxylic acid(s) with (B) a component or components providing (a) hydroxyl(s) and/or dihydroxyl(s).
[0017] Preferably said polyester system involves a co-reactive monomer.
[0018] A preferred co-reactive monomer is styrene or a styrene derivative or analogue.
[0019] Preferably the co-reactive monomer is styrene or a styrene analogue that is present in the polyester system in a quantity from 30-55% w/w and most preferably, if styrene, 35-45% w/w.
[0020] Preferably the system when cured has an elongation at break greater than 150% (preferably greater than 170%).
[0021] Preferably the unsaturated polyester resin containing ethylenic unsaturation is present in the range of from 45-70% w/w.
[0022] Preferably the polyester system is or has been catalysed by free radical initiators, eg; a chemical initiator not reliant upon UV light. Alternatively, it can have been catalysed by a UV initiator of free radicals.
[0023] Preferably the polyester system has included or includes a metal salt provider to speed gel time upon initiation. This is particularly the case if a peroxide free radial initiator such as a MEKP is utilised (Methyl Ethyl Ketone Peroxide).
[0024] Preferably the level of said metal salt promoter is of the same order of or is less than the level of inclusion of any such initiator.
[0025] Preferably the level of any such initiator is no more than about 2% w/w of the system prior to the thermoset.
[0026] Preferably the level of such an initiator is less than 1% w/w of the thermoset system.
[0027] Preferably the lamination of the cursor laminate has involved the laying between the sheets, or the laying on one sheet and subsequent placement of the second sheet, of a liquid polyester system and thereafter allowing its thermoset.
[0028] Preferably the polyester resin system was a mix of:
45-70% w/w unsaturated polyester resin containing ethylenic unsaturation, 30-55% w/w styrene, less than 2% w/w catalyst (eg; MEKP), and less than 2% w/w initator (eg; metal salt provider).
[0033] Preferably the polyester resin system was mixed in the temperature range 18 to 22° C. (preferably about 20° C.). Preferably the polyester resin system sets at temperature(s) in the range 20° C. to 24° C. (preferably 22° C.).
[0034] Preferably the polyester resin system was mixed at a humidity in the range 57% to 67% (preferably about 62%). Preferably the resin is allowed to thermoset as a result of chemical initiation and its exothermicity at a humidity in the range of from 57% to 75% (preferably 62% to 73%) (eg; about 67%).
[0035] Preferably that surface of the acrylic plastic which is to interface with the polyester system is a clean face, ie; free of release agents and/or migrating materials from any removed cover sheet.
[0036] Preferably the surface of the sheets has been subjected to cleaning with a solvent.
[0037] Preferably said sheets have had the surface thereof to be presented to the polyester system, prior to its thermoset, cleaned with isopropyl alcohol.
[0038] Preferably said “without any substantial degradation” has involved some deformation of each layer but has not lead to any substantial detachment of the polyester system attachment to each said sheet.
[0039] Preferably throughout the curving process the interposed polyester system has remained non liquid, ie; has stretched, deformed, slipped and/or otherwise changed in shape without manifesting liquid characteristics, eg; as if it were a rubber or like material.
[0040] Preferably said interposed thermoset polyester system is of an unsaturated polyester system containing ethylenic unsaturation that has been linked with a coreactive monomer.
[0041] Preferably the polyester system is one which (without wishing to be limited to a theory) provides an attachment to each sheet as a result of either or both
cross linking with any free unsaturation in the acrylic material free monomer solvation of the acrylic material.
[0044] Preferably there is both chemical, (ie; said cross linking) and physical adhesive (ie; free monomer solvation of the acrylic material) attachment.
[0045] Preferably said polyester system has thermoset to a non tacky form at its interface with the acrylic material and it is only where there is air access to the material that there is a residual tackiness. Preferably the material has a pliable physical character at ambient temperatures.
[0046] Optionally the polyester system includes one or more of pigmentation(s), fire retardant additive(s) and filler(s).
[0047] Preferably the laminate is transparent.
[0048] Preferably the acrylic sheet(s) have been mixed and/or cured at about 20° C. and/or about 65% humidity.
[0049] In another aspect the invention consists in a self supporting laminate product comprising or including two sheets of an acrylic thermoplastic, or of sheets including an acrylic thermoplastic, spaced by, but attaching to, an interposed thermoset polyester system, the interposed polyester system being of some or all of, or at least,
[0050] Preferably one or both sheets is of an acrylic plastic or is at least primarily acrylic plastic.
[0051] Preferably styrene is present at 35-45% w/w.
[0052] Preferably the system when cured has an elongation at break greater than 150% (preferably greater than 170%).
[0053] Preferably the polyester system is or has been catalysed by free radical initiators, eg; a chemical initiator not reliant upon UV light. Alternatively, it can have been catalysed by a UV initiator of free radicals.
[0054] The polyester system has preferably included or includes a metal salt provider to speed gel time upon initiation. This is particularly the case if a peroxide free radial initiator such as a MEKP is utilised (Methyl Ethyl Ketone Peroxide).
[0055] Preferably the level of said metal salt promoter is of the same order of or is less than the level of inclusion of any such initiator.
[0056] Preferably the level of any such initiator is no more than about 2% w/w of the system prior to the thermoset.
[0057] Preferably the level of such an initiator is less than 1% w/w of the thermoset system.
[0058] Preferably the lamination of the cursor laminate has involved the laying between the sheets, or the laying on one sheet and subsequent placement of the second sheet, of a liquid polyester system and thereafter allowing its thermoset.
[0059] Preferably the polyester resin system was a mix of:
45-70% w/w unsaturated polyester resin containing ethylenic unsaturation, 30-55% w/w styrene, less than 2% w/w catalyst (eg; MEKP), and less than 2% w/w initator (eg; metal salt provider).
[0064] Preferably the polyester resin system was mixed in the temperature range 18 to 22° C. (preferably about 20° C.). Preferably the polyester resin system sets at temperature(s) in the range 20° C. to 24° C. (preferably 22° C.).
[0065] Preferably the polyester resin system was mixed at a humidity in the range 57% to 67% (preferably about 62%). Preferably the resin is allowed to thermoset as a result of chemical initiation and its exothermicity at a humidity in the range of from 57% to 75% (preferably 62% to 73%) (eg; about 67%).
[0066] Preferably that surface of the acrylic plastic which is to interface with the polyester system is a clean face, i.e.; free of release agents and/or migrating materials from any removed cover sheet.
[0067] Preferably the surface of the sheets has been subjected to cleaning with a solvent.
[0068] Preferably said sheets have had the surface thereof to be presented to the polyester system, prior to its thermoset, cleaned with isopropyl alcohol.
[0069] Preferably said “without any substantial degradation” has involved some deformation of each layer but has not lead to any substantial detachment of the polyester system attachment to each said sheet.
[0070] Preferably the laminate can be subjected to a curving process under non destructive heating during which the interposed polyester system remains non liquid, i.e.; can stretch, deform, slip and/or otherwise change in shape without manifesting liquid characteristics, eg; as if it were a rubber or like material.
[0071] Preferably the polyester system is one which (without wishing to be limited to a theory) provides an attachment to each sheet as a result of either or both
cross linking with any free unsaturation in the acrylic material free monomer solvation of the acrylic material.
[0074] Preferably there is both chemical, (i.e.; said cross linking) and physical adhesive (i.e.; free monomer solvation of the acrylic material) attachment.
[0075] Preferably said polyester system has thermoset to a non tacky form at its interface with the acrylic material and it is only where there is air access to the material that there is a residual tackiness. Preferably the material has a pliable physical character at ambient temperatures.
[0076] Optionally the polyester system includes one or more of pigmentation(s), fire retardant additive(s) and filler(s).
[0077] Preferably the laminate is transparent.
[0078] Preferably the acrylic sheet(s) have been mixed and/or cured at about 20° C. and/or about 65% humidity.
[0079] In another aspect the invention is a self supporting transparent laminate able to be curved when all layers of the laminate are heated to a temperature or temperatures unable to melt any layer to a liquid form, the laminate being of a transparent polyester system interposed and attaching to flanking transparent thermoplastic layers (the same or different), which thermoplastic layers attach to the polyester system by both
cross linking with any free unsaturation in the acrylic material free monomer solvation of the acrylic material.
[0082] In another aspect the invention is a self supporting transparent laminate able to be curved when all layers of the laminate are heated to a temperature or temperatures unable to melt any layer to a liquid form, the laminate being of a transparent polyester system interposed and attaching to flanking transparent acrylic thermoplastic layers (the same or different).
[0083] In another aspect the invention is a self supporting transparent laminate greater than 3 mm thick able to be curved when all layers of the laminate are heated to a temperature or temperatures unable to melt any layer to a liquid form, the laminate being of a transparent polyester system interposed and attaching to flanking transparent thermoplastic layers (the same or different), the polyester system being at least 0.5 mm thick.
[0084] The polyester system can account for from 5% to 40% of overall laminate thickness.
[0085] Preferably in any of the foregoing laminates the polyester system layer is at least 1 mm thick (preferably from 1 to 3 mms thick, eg; about 2 mm)
[0086] Preferably the acrylic sheet(s) is (are) at least 0.5 mm thick. More preferably from 0.5 to 5 mm thick (eg; about 2 mm)
[0087] The laminates can be symmetric as to pairing of the acrylic layers (thickness and/or material), or not. They can be asymmetric.
[0088] The laminates can also, or instead, be symmetric three, five, seven or more layered panels, or not. A five layer laminate would have two polyester system layers.
[0089] In another aspect the invention is a self supporting transparent planar laminate (preferably able to be curved when all layers of the laminate are heated to a temperature or temperatures unable to melt any layer to a liquid form), the laminate being of a transparent polyester system interposed and attaching to flanking transparent acrylic thermoplastic layers (the same or different) (ie; a symmetric three layer system where the acrylic layers are symmetric with each other and, also preferably of the same thickness as the polyester, the laminate system having a performance related to a notional variant having acrylic layers 2 mm thick on the outside and a polyester system 2 mm thick, being able without fracture and/or delamination to withstand a challenge loading in excess of 40 tonnes into its edges, on its minor axis if notionally a rectangle of 960×470 mms.
[0090] By way of example a polyester resin system in the form of
45-70% w/w unsaturated polyester resin containing ethylenic unsaturation, 30-55% w/w styrene, less than 2% w/w catalyst (eg; MEKP), and less than 2% w/w initator (eg; metal salt provider), and a thickness of 2 mm, 2 mm and 2 mm through the three layer laminate, when a rectangular panel of 960×470 mm squeezed on its minor axis can withstand without delamination between 60 and 80 tonnes.
[0096] The present invention therefore envisages laminates analogous to such performing laminates whether to be used in a planar form or in a curved form.
[0097] In another aspect the invention is a transparent laminate of at least three layers to an overall thickness of greater than 3 mm wherein a polyester resin system as a layer attaches to each of two acrylic layers the polyester resin system interposes.
[0098] In another aspect the invention is a transparent laminate of at least three layers to an overall thickness of greater than 3 mm wherein a polyester resin system as a layer attaches to each of two acrylic layers the polyester resin system interposes, the laminate being able to be curved under non destructive heating to a curved self supporting transparent form.
[0099] In another aspect the invention is a transparent laminate of at least three layers to an overall thickness of greater than 3 mm wherein a polyester resin system as a layer attaches to each of two acrylic layers the polyester resin system interposes, wherein the laminate is of any of the kinds previously defined.
[0100] In another aspect the invention is the use or methods of use and resulting structures of any planar and/or curved laminates as aforesaid.
[0101] In another aspect of the invention there is provided a laminate comprising:
a) a first thermoplastic layer, b) a second thermoplastic layer, and c) a thermoset resin layer intermediate between the first and second layers, wherein the thermoset layer is bonded to both layers and wherein there is a degree of cross linked bonding between the resin and the thermoplastic layers.
[0105] Preferably the thermoset resin is an unsaturated polyester resin. More preferably the thermoset resin, prior to curing, is a solution of a polyester in a monomer. Preferably the cross linked bonding is between the monomer and unsaturated sites available for bonding in the thermoplastic layers.
[0106] Preferably the monomer is styrene.
[0107] Preferably the resin has 30-45% styrene content.
[0108] Preferably the resin has an elongation at break of >150%; more preferably it has an elongation at break of around 170%. Preferably the resin has a glass transition temperature less than ambient temperature.
[0109] Preferably the styrene of the resin softens the surface of the thermoplastic layers allowing some degree of penetration of the resin into the thermoplastic layers.
[0110] In one embodiment at least one or both of the thermoplastic layers is polyethylene terphthalate glycol. In an alternative embodiment at least one or both of the thermoplastic layers is acrylic.
[0111] Preferably when the thermoplastic layer(s) is/are acrylic there is cross linking between unsaturated methyl methacrylate in the acrylic with the styrene monomer of the resin.
[0112] Preferably the resin has been catalysed by the addition of a free radical inhibitor; more preferably by the addition of a methylethyl ketone peroxide catalyst.
[0113] Preferably the acrylic is Polymethyl methacrylate (PMMA) or poly(methyl 2-methylpropenoate); preferably it is SHINKOLITE™ acrylic from Mitsubishi Rayon Japan.
[0114] Preferably the thermoplastic layer(s) have a degree of styrene resistance; preferably a high degree of styrene resistance. Alternatively or additionally the thermoplastic layer(s) have a styrene resistant surface coating.
[0115] Optionally the thermoplastic sheet(s) may be treated with one or more of the following:
a mar resistant coating solar protective additives (added after preparation or in its resin state upon preparation) texturing/etching/embossing/paint applied photographic imagery, transfers or reflective mirror coatings vinyls and metallic materials such as aluminium can be bonded and pressed onto outer surfaces an annealing process
[0122] Optionally the thermoset resin may include or be treated with one or more of the following:
pigmentation fire retardant additives filler materials.
[0126] Preferably the laminate of the invention is substantially transparent with a TV (rating total visible light) close to 100%.
[0127] Preferably when the thermoplastic sheet(s) is/are acrylic, they have been mixed under the pour conditions of around 20° C. temperature and around 65% humidity, and cured at around 20° C. and around 65% humidity.
[0128] In another aspect of the invention there is provided a method of preparing a laminate comprising the steps of:
providing resin precursor materials, adding a catalyst the resin precursor materials to give a catalysed thermoset resin, inserting a layer of the catalysed thermoset resin between two thermoplastic layers, and allowing the catalysed thermoset resin (the resin) to bond to the two thermoplastic layers,
[0133] wherein the step of allowing the resin to bond to the thermoplastic layers includes allowing the resin to cross link with the thermoplastic layers.
[0134] Preferably the catalysted thermoset resin formed in the first step is an unsaturated polyester resin; more preferably of a polyester in styrene monomer. Preferably the resin has 30-45% by weight styrene content. Preferably the resin has an elongation at break of >150%. Preferably the resin has a glass transition temperature less than ambient temperature.
[0135] Preferably the step of bonding includes cross linking between the thermoplastic layers and the styrene monomer of the resin. Preferably the step of bonding further includes softening of the surface of the thermoplastic layers by the styrene and a degree of penetration of the resin into the thermoplastic layers.
[0136] In one preferred form the thermoplastic layers are acrylic layers and the step of bonding includes cross linking between the styrene monomer of the resin with unsaturated methyl methacrylate sites of the acrylic.
[0137] In one embodiment the method is a batch process and the step of inserting a layer of the resin between two thermoplastic layers comprises pouring liquid (prior to gelation or curing) resin between two supported thermoplastic sheets and allowing to cure.
[0138] In an alternative embodiment the method is a continuous process and the step of inserting a layer of the resin between two thermoplastic sheets comprises advancing a first sheet or layer of the resin through a laminating station where at least one or preferably two of the thermoplastic layers contact the sheet or layer of resin.
[0139] In one form of the embodiment the resin is in a pre-gel state.
[0140] In another form of the embodiment the resin is in a gel-like state, at or near gelation of the resin.
[0141] In another form of the embodiment the resin is in a cured state and the step of advancing the resin may include heating the resin and/or one or both of the thermoplastic sheets to at least soften the resin and/or one or both of the thermoplastic sheets, prior to, or at about the same location as, or after, the laminating station.
[0142] In a further aspect there is provided a laminate material prepared according the above method.
[0143] In a further aspect of the invention there is provided a method of producing a curved laminate material comprising the steps of:
providing a laminate as hereinbefore described or produced according to the abovementioned method, wherein the thermoset resin has an elongation at break of >150% and a glass transition temperature less than ambient temperature, heating a shaping region of the laminate to a shaping temperature, shaping the laminate to the desired curvature, cooling the laminate,
[0148] wherein the step of heating the shaping zone of the laminate comprises heating substantially through all layers (including the thermoset and thermoplastic layers) of the laminate in the shaping zone.
[0149] Preferably the step of heating the shaping region comprises applying heat to the shaping region from both a top surface of the laminate in the shaping region, and a bottom surface of the laminate in the shaping region.
[0150] Preferably the conditions of the heating step, including one or both of the shaping temperature and the duration of the heating, is/are not sufficient to result in annealing of any of the layers of the laminate in the heating region.
[0151] Preferably the step of cooling the shaping region comprises allowing the laminate to cool to ambient temperature.
[0152] Preferably the step of shaping the laminate comprises placing the substrate over a mould or template and applying pressure (which may simply be gravity) to one or more regions of the laminate adjacent the shaping region.
[0153] In a further aspect there is provided a curved laminate material or article incorporating a region of curved laminate prepared according the above method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0154] The invention will now be described by way of example only and with reference to the drawings in which:
[0155] FIG. 1 illustrates a perspective end view showing a transparent laminate constructed with principles of the present invention;
[0156] FIG. 2 illustrates a perspective end view showing a transparent multiple ply constructed with principles of the present;
[0157] FIG. 3 illustrates the molecular characteristics of the unsaturated polyester resin before the laminated sheet is thermoformed into shape;
[0158] FIG. 4 illustrates the molecular characteristics of the unsaturated polyester resin when the laminated sheet is thermoformed into one desired shape;
[0159] FIG. 5 illustrates the use of fire retardant and foamed resin materials;
[0160] FIG. 6 preferred thermoforming heating process;
[0161] FIGS. 7 a , 7 b , 7 c illustrates side views of the jig of Example 3;
[0162] FIGS. 8 a and 8 b illustrates part of the process of Example 3;
[0163] FIG. 9 illustrates delamination; due to absorption of resin into incorrect rubber type dam seal;
[0164] FIG. 10 illustrates light travel in the laminate of the invention;
[0165] FIG. 11 illustrates one form of continuous manufacturing.
DEFINITIONS
[0166] As used herein the term “and/or” means “and” or “or”, or both.
[0167] As used herein “(s)” following a noun means the plural and/or singular forms of the noun.
[0168] “The term “comprising” as used in this specification and claims means “consisting at least in part of”; that is to say when interpreting statements in this specification and claims which include “comprising”, features, other than those prefaced by this term in each statement, can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in similar manner.”
[0169] As used herein is apparent that the term “thermoset” in respect of the polyester system encompasses a chemical initiated and/or UV light initiated polymerisation between the unsaturated polyester resin with its ethylenic unsaturation and the coreactive monomer(s). Once there has been such a thermoset, even if still to a pliable form (preferably non-tacky when excluded from ambient air), the material nonetheless can be deformed at the elevated temperature (i.e.; above ambient) required or chosen for reshaping of the thermoset acrylic material sheets without any substantial degradation of the laminate including the attachment of the polyester system to the acrylic material.
[0170] As used herein the term “curving” (and any derivative thereof eg; “curve” or “curved”) encompasses any mechanical manipulation of the precursor laminate that provides a three dimensional out come from the planar laminate eg; a curve of any shape, any bulge, any fold, etc. and includes part only of the overall precursor laminate sheet or all of it.
[0171] As referred to herein the term “laminate” preferably refers to a planar or curved sheet where the outer sheets (eg; of thermoplastic) and the interposed material of the polyester system is substantially coextensive. In some applications however this need not be the case, i.e.; there can, if desired, be unmatching of the outer sheets with respect to each other and/or one or both of the outer sheets with respect to the extent of the interposed polyester system, eg; if desired, some parts of an overall laminate could have direct fixing of one outer sheet to the other whilst other regions thereof have the polyester system interposed between such sheets.
[0172] As used herein, the term “forming” refers to any process by which the shape of a sheet is altered and includes, but is not limited to, bending, shaping, stretching, compressing, curving or arching a sheet.
[0173] As used herein, the term “styrene resistance” refers to the ability of the thermoplastic sheet(s) to resist the corrosive effect/attack of styrene. It is likely to relate to the resistance of the sheet to solubilisation by or in styrene. Styrene is present for example in one preferred thermoplastic resin.
[0174] As used herein, the term “transparency” refers to allowing of light to pass through the glazing without causing distortion, loss of clarity, or altering light transmission.
[0175] As used herein, the term “haze” refers to dullness or cloudiness. This can occur due to incompatibility of a resin with the outer sheets. For example the inner surface of the sheet becomes stressed and can react by separating its surface, and in severe cases complete delamination.
[0176] “Elongation” or “Elongation at break” is a standard measure for the amount a sample can stretch as a percentage of original length before it fails or breaks.
[0177] “Glass transition temperature” in respect of the resin means the temperature at which a reversible change occurs in the resin to undergo a rather sudden transition from a hard, glassy, or brittle condition to a flexible or elastomeric condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0178] This invention relates to a laminate material comprising a layer of thermoset resin inserted between two or more thermoplastic sheets. The preferred thermoplastic sheets are of acrylic, or polyethylene terphthalate glycol (P.E.T.G.).
[0179] FIG. 1 illustrate such a laminate, with outer sheets 1 , of acrylic, or P.E.T.G. and an inner layer 2 of resin. The thickness of the laminate when complete can vary depending on the thickness of the resin inserted between the thermoplastic sheets and also to the number and thickness of thermoplastic sheets and resin employed. FIG. 2 illustrates such a multi-ply laminate.
[0180] There have been several attempts to provide laminates using various forms of plastic sheets and protective coverings. Although this invention was initially developed as an alternative to glass for use in the building and construction industry, the invention has wide reaching applications as a result of the lightweight, extreme strength and formability of the laminate panel. For example, the panel can be formed or worked to construct boat hulls, vehicle construction including monocoque assembly and outside panels, furniture, household appliances and a wide variety of manufactured goods. It should therefore be regarded as a construction and manufacturing material.
[0181] The simplest embodiment of the laminate material of the invention is a single layer of thermoset polyester resin sandwiched between two layers of thermoplastic acrylic, or P.E.T.G. (as illustrated in FIG. 1 ).
[0182] One preferred method of preparing the laminate sheet is a continuously manufactured process by which the two sheets are brought together and injected with the unsaturated polyester resin at the correct temperature and humidity required for the resin curing process. The resin is bonded with the outer sheets. One alternative method of preparation is a batch process involving assembling the two outer sheets in a parallel arrangement in a jig or equivalent, and pouring or injecting the resin between the sheets.
[0183] Another alternative is to manufacture the resin to the required thickness in sheet form, or in continuous form. The continuous resin can be then rolled and stored onto a drum ready for introduction to manufacturing process. When ready the two outer thermoplastic sheets can be heated and pressed either side of the solidified resin (which may have been heated) to create a solid ply. The bonding between the resin and sheets must be controlled accordingly.
[0184] One further aspect of the invention relates to a method of forming or shaping the laminate and the ability of the laminate to be formed. Once prepared the laminate is then heated to a temperature, at which the laminate can be formed or shaped, and then forming or shaping the laminate to a desired curvature and configuration. This invention includes the forming of a laminate in both single and complex curvatures. For example, a curvature shape, a corrugation shape and a 90° angle are achievable with the present invention after a thermoforming procedure.
a) Thermoplastic Sheets
[0185] The preferred outer sheets of the laminate can be of acrylic or P.E.T.G. sheeting.
[0186] By acrylic we mean a material composed of various clear, thermoplastic resins obtained from acrylic acid and its derivatives, and from raw natural sources such as petroleum and natural gas. moulded, and thermoformed. By P.E.T.G. we mean glycol-modified terephthalate glycol.
[0187] All of the above preferably have inherent chemical resistance to the styrene as one preferred thermoset resin contains styrene. Sheets that have insufficient styrene resistance (i.e. are likely to dissolve in or disintegrate upon contact with, styrene) are subject to poor adhesion, break down of the sheet surface due to the corrosive reaction build up on the contact face to be bonded.
[0188] An alternative approach to the styrene resistance requirement is the use of a styrene resistant coating on the sheeting prior to exposure to the resin. This is a protective coating acting as a barrier between the sheeting and the resin, as would be contemplated by one skilled in the art.
[0189] Standard acrylic plastic sheet is a more cost effective material with good optical properties, and less resistant to scratching in comparison to P.E.T.G. Further, the less cross linked the acrylic structure, the more suitable for the laminate of the invention as the free methyl methacrylate sites can cross link with the resin as discussed below. However, all materials are employed within the scope of the invention. The laminate can contain two (or more) layers of acrylic; or two (or more) layers of P.E.T.G.
b) The Resin Material
[0190] As would be known by one skilled in the art there are a number of thermoset resins which are capable of bonding two thermoplastic sheets together. However the resin suitable for the laminate of the invention must have the following characteristics—
An unsaturated polyester resin Elongation at break characteristics sufficient to allow thermoforming of the laminate. Preferably an elongation over 150%; more preferably an elongation of around 170% or higher. A low glass transition temperature, which is less than ambient temperature. The preferred use of styrene as the monomer. Preferred styrene content is in the range 40-45%. Most polyester resins are viscous, pale coloured liquids consisting of a solution of a polyester in a monomer. The addition of styrene in amounts of up to 50% helps to make the resin easier to handle by reducing its viscosity. The styrene also performs the vital function of enabling the resin to cure from a liquid to a solid by ‘cross-linking’ the molecular chains of the polyester, without the evolution of any by-products. In the case of the current laminate invention we believe the styrene also has the role of softening the thermoplastic layers of the outer sheeting thereby assisting in the bonding process. In the case of acrylic sheeting the styrene may also be cross linking with unsaturated methyl methacrylate sites. For use in moulding, a polyester resin can benefit from the addition of several ancillary products. In particular a catalyst is required in the invention. The catalyst is added to the resin system shortly before use to initiate the polymerisation reaction. The catalyst does not take part in the chemical reaction but simply activates the process. Accelerators may also be used to speed up the curing process.
[0196] Upon addition of the catalyst, in the presence of the styrene, the styrene cross-links the polymer chains in a polymerisation process, to form a complex three-dimensional network. This is the curing process.
[0197] Care is needed in the preparation of the resin mix prior to moulding. The resin and any additives must be carefully stirred to disperse all the components evenly before the catalyst is added. This stirring must be thorough as any air introduced into the resin mix affects the quality of the final moulding. This is especially so when laminating with layers of reinforcing materials as air bubbles can be formed within the resultant laminate which can weaken the structure. It is also important to add the accelerator (if any) and catalyst in carefully measured amounts to control the polymerisation reaction to give the best material properties. Too much catalyst will cause too rapid a gelation time, whereas too little catalyst will result in under-cure.
[0198] An alternative monomer to styrene is methyl methacrylate. This is also within the scope of the invention.
Preferred Resin
[0199] One preferred resin we use is NC007 resin. This is a flexible, low viscosity, clear unsaturated polyester resin in styrene monomer. It is preferably prepromoted (i.e. pre-mixed together and batched prior to the introduction of the catalyst). We recommend that it should be gelled and cured with between 0.75 and 2% of a medium reactivity MEKP catalyst. MEKP (Methyl Ethyl Ketone Peroxide, a free radical initiator) is the catalyst added to polyester resins and vinyl ester resins. As the catalyst mixes with the resin, a chemical reaction occurs (as mentioned previously), creating heat, which cures (hardens) the resin.
[0000]
NC007 TYPICAL LIQUID PROPERTIES:
Viscosity @ 25° C.
1.5
ps
Gel time @ 25° C. 1% MEKP
45
minutes
Volatile content
36%
Appearance
Clear pale pink
[0000]
NC007 TYPICAL PHYSICAL PROPERTIES:
% elongation at break
170%
Tensile strength
3.2 mPa
[0200] The performance and characteristics of this resin during thermoforming is crucial to the success of the laminate.
[0201] Our preferred resin has an elongation percentage capacity of around or above 150%. This particular resin has an elongation at break of around 170%. It must be worked at between 105° C. and 120° C. At these temperatures we observe increased malleability allowing the molecules to stretch, settle, and when cooled hold their elongation and adhesion to the sheet surface. This can be shown in FIGS. 3 and 4 . FIG. 3 shows the laminate structure prior to forming including resin 41 and thermoplastic layers 42 .
(a) During the heating process the molecules of the resin begin to change shape and expand as the laminate product becomes more malleable. When the heating process begins prior to the forming and shaping process, the molecular structure of the internal resin within the laminate changes shape from being circular and honey combed to a more elongated state and stretches along the laminate surface as it is bent into shape. (b) When the temperature of all layers reach the desired forming temperature of between 105° C. and 120° C. forming is commenced. The time that the temperature takes to produce the penetration required will depend on the thickness of the ply being formed. FIG. 4 illustrates the change in structure of the resin 41 and thermoplastic layers 42 upon heating.
[0204] The fact that the product can be laminated, then put through a thermo-forming process which involves the heating of the finished product, bending or forming into any shape, and when cooled retains its form without delamination and loss of tensile strength is a surprising outcome. The controlled environment and the factors necessary to ensure that the forming process is successful allow the laminate product to change in molecular structure at exactly the right time and effect to produce a successful and different structural outcome.
Catalyst for Resin Curing
[0205] As mentioned above, a catalyst is required to cure the resin. It acts as an initiator for curing the resin. The general catalyst type suitable for the invention is a free radical inhibitor, preferably a MEKP (methylethyl ketone peroxide catalyst). One catalyst we have used successfully is our F00826 coded Catalyst (MEKP 40%) QC. It is a MEKP catalyst, with the following components:
[0000]
Dimethyl phthalate/dipropylene glycol phlegmatiser
30-70%
Methyl ethyl ketone peroxide
30%
Methyl ethyl ketone
0-10%
2,4-pentanedione peroxide
0-10%
[0206] It has a self-accelerating decomposition temperature (SADT) of approximately 60° C.
Gel and Cure Times; Procedure
[0207] Gel time refers to the point at which the catalyst and resin have crossed from an unstable liquid state to a state of at least semi hardness, or state of stability. If the early part of the curing or bonding (to the outer sheets) is disturbed then this could result in ultimate delamination. However, there is a time during the gel stage, before full cure, when the sheet may be manoeuvred, cut, and stored for a full cure time. It is important not to lift, bend or stress the sheet but rather to slide and manoeuvre the sheet along an aerated flat bed surface or flat belt feed table/conveyer.
[0208] The set time—refers to the point in time in which catalyst and resin complete cure and full adhesion to the sheet surfaces has occurred.
[0209] The time of complete cure and set will depend on the manufacturing process being used. By maximising the amount of catalyst and or accelerators and heating the NC007 system will dramatically accelerate the cure time. However whatever process is used a recommended period of 12 hours in storage prior to use.
c) Preparation of the Laminate
[0210] As mentioned previously, there are 3 main ways like laminate or the invention can be prepared. A batch process, (e.g. using a jig to hold sheets in place), a continuous process whereby the resin is poured or inserted between the sheets in a manufacturing line or alternatively using three solid sheets (two thermoplastic with the resin) and placing in contact with heating. The batch process is illustrated in the Examples. Typically in the batch process an amount of resin is mixed with the corresponding amount of catalyst using a mechanically assisted paddle. It is stirred for 2 minutes, allowed to stand for 2 minutes, or vibrated to allow excess air bubble removal. The formula is then poured directly into the cavity sample held within the cradle, a fine brass meshed funnel is used to further assist mixing and aiding in further removal of trapped air bubbles.
[0211] One form of continuous process could be as illustrated in FIG. 11 . This involves applying two outer thermoplastic sheets to pre-mixed resin. The variants of this include using simply pre-mixed (still runny) resin; semi-set (jelly-like) resin and fully set resin which is then heated to soften and applied. The Figure illustrates a semi-set resin 121 and rolls of outer skin 122 . The laminate proceeds through press rollers 123 to a mobile caterpillar pressure plate 124 . An outer edge dam rubber or caterpillar rotating outer edge seal is optional (to prevent overflow of liquefied resin during manufacture).
[0212] It should be noted that often thermoplastic sheeting is supplied from the manufacturer with a protective plastic or paper. This can be on one or both side(s). It should be removed prior to laminate preparation.
d) The Bond Between the Acrylic/P.E.T.G and the Resin
[0213] As mentioned previously, the bond between the resin is an important feature of the invention. In the preferred embodiment the resin includes 30-45% styrene content. This styrene plays an important role in the preferred bond formation. Without being bound by the following theory we believe the presence of the styrene can soften the surfaces of the outer thermoplastic layers and allow some penetration of the resin. Further we believe it is able to cross link with the outer thermoplastic layers to create the bonding. For example with acrylic outer sheets, the styrene monomer of the resin is able to cross link with any residual methyl methacrylate sites of the acrylic.
e) Bending/Forming the Laminate
[0214] The thermoforming or shaping process is one preferred forming method. It involves forming the flat laminate sheets into the desired shape by concentrating the required heat, in and onto a particular area rather than the system of having the whole sheet oven heated. Thus a particular area of the sheet may be bent/shaped at a temperature which the acrylic, or P.E.T.G softens and the unsaturated polyester resin changes consistency such as will allow the panel or sheet to be formed into the desired shape.
[0215] Commonly in the art forming occurs via strip forming. This involves heating a sheet from one side, relying on one radiated heat source to pass through the entire sheet prior to bending.
[0216] The single side heating approach is efficient and acceptable for normal and standard non-ply sheet. However it is not preferred for our laminate (but is still possible under certain conditions).
[0217] The temperature and time need to penetrate our ply sheet samples is critical as an undesired annealing process can take place if the temperature is too high for too long. The time and temperature required to penetrate our ply sheet with a single heat strip forming bar/heating from one side may result in an annealing effect of the heat exposed side of the sheet resulting in crazing, shattering or snapping the outer sheet to splitting the core ply and delamination during the forming process. We use a process of directing a heat source from both top and bottom, allowing a deeper more even penetration meeting toward the core of the ply. For a particular laminate structure there will be a desired temperature and time period to bring about correct malleability and prevent an annealing of the sheet surface and delamination a and fault. It is therefore important to not exceed the correct forming temperature and time period.
f) Optional Features
[0218] i) Mar Coating
[0219] An optional mar coating can be used to enhance resistance to abrasive or chemical attack. While two-side coated laminate (i.e. on the outer sides of the laminate) provides maximum protection, one-sided coated laminate offers economical advantages for application where only one side of the sheet is exposed.
[0220] ii) UV Protection
[0221] We can include UV inhibitors within the thermoset resin in order to enhance the UV resistance of the laminate. The UV resistance enhances the properties of the laminate as a building material (by protecting what is inside the building) but also increases the longevity of the laminate itself.
[0222] iii) Colour/Tinted/Clear
[0223] It is possible to provide a colouring/tinting finish to the laminate by use of coloured or tinted thermoplastic sheeting. Both opaque and translucent laminates can be prepared by appropriate selection of the sheets. Alternatively transparent thermoplastic sheeting can be used and we can tint or colour the thermo set resin as would be known by one skilled in the art. Colouring of the resin mix can be carried out with pigments. The choice of a suitable pigment material, even though only added at about 3% resin weight, must be carefully considered as it is easy to affect the curing reaction and degrade the final laminate by use of unsuitable pigments.
[0224] iv) Fire Retardant
[0225] As shown in FIG. 5 , fire retardant materials can be added to the thermoset resin 60 , which is sandwiched between the outer thermoplastic sheets 42 . It is likely a drop in transparency will be the result of this however.
[0226] v) Fillers
[0227] We can also use filler materials within the resin for a variety of reasons including:
To reduce the cost of the moulding To facilitate the moulding process To impart specific properties to the moulding
[0231] Fillers are often added in quantities up to 50% of the resin weight although such addition levels will affect the flexural and tensile strength of the laminate. The use of fillers can be beneficial in the laminating or casting of thick components where otherwise considerable exothermic heating can occur. Addition of certain fillers can also contribute to increasing the fire-resistance of the laminate.
[0232] vi) Other Possibilities
[0233] Other vinyls, metallic panels, such as aluminium, and fire retardant materials may be bonded and pressed to the outer layer of the resin sheet for requirements and cosmetics in the building industry. We can also place transfers, articles, and objects such as solar pick up panels within the resin formula within the cavity creating a solar glazing panel.
g) Advantages of the Laminate of the Invention
[0234] One preferred embodiment of the laminate sheet of the invention provides one or more of the following advantages when compared to glass:
Improved optical clarity Ease of fabrication Abrasion resistance Lightweight—half weight of glass Chemical resistance Strength—improved impact strength compared with glass Improved acoustic resistance Workable—skill saw cutting, drill and router Thermal resistance Thermoform ability
h) Blue Effect/Hazing
[0245] At times the product laminate can have hazing or blue lining. This tends to be due to one of three causes:
1) the effect of refraction due to the fibre optic effect of the sheet and formula eg; the edge of the sheet when exposed to light absorbs the light and allows light to travel the length of the sheet (see FIG. 10 ). At cure if there is a significant distortion in the outer sheet surface, or detour of the line of light travel, internal reflection may result, giving the appearance of a light blue, smoke haze. 2) The incorrect catalyst mix can cause the inner cavity formula to appear cloudy rather than having the same light refraction as the acrylic sheet, again causing internal reflection. 3) There is the possibility that the inner cavity sheet surface has been slightly tainted due to the percentage of non-styrene resistance.
[0249] Remedy for blue hazing:
The outer edge of the sheet can been sealed to prevent light travel; Ensure the jig or other setting apparatus results in a flat surface for curing; Ensure the correct catalyst mix percentage Ensure the correct sheet/styrene percentage Use a range of translucent tints.
EXPERIMENTAL
Example 1
One Preferred Formulation
[0255] The tests samples 300 mm×300 mm of continuous and cell cast acrylic called Shinkolite™ of Mitsubish Rayon, Japan were used. They were set in place in the jig to prevent distortion and set at 30° angle for pouring so any air bubbles may rise. Vibration can be applied to speed the release of any air.
[0256] The mixture of resin and Catalyst were as follows
[0257] Resin NC007 500 grms
[0258] Catalyst NA1 5 grms
[0259] Mix time 2 min
[0260] Mix temp 20°
[0261] Mix humidity 62%
[0262] Setting temp 22°
[0263] Humidity 67%
[0264] The sample pour can remain in upright in the jig during the cure process in a hot box. Alternatively the entry hole (used for the filling) can be plugged and then sample laid flat for curing in the hot box.
[0265] Generally samples should be left at least 8 hours before handling. In order to speed this up post-curing can be used.
[0266] Post curing can be a matter of preparing the catalyst within the resin some time prior to the pour so as the gel time can be due at introduction to the cavity rather than the gel time being to long within the sheet on the table therefore slowing down production. Ideally while the process is continually on the move the sheet should be at gel stage after five or so meters ready for cutting to length and storage. More catalyst and the heating of the sheet and resin during pour would speed up the cure time dramatically also. We can also add a gel accelerator.
Example 2
Cleaning and Preparing Cavity Side of Sheet
[0267] This can be necessary due to possible contamination from the various adhesives used with protective plastic wrap, which can be applied by some manufacturers. Simply, the adhesive glue is removed with an appropriate cleaner. We have used methylated spirits (both industrial and household) but find iso propyl Alcohol is the most preferred. The preferred cleaner will depend upon the different wraps used by the different manufacturers.
[0268] Alternatively we use the acrylic, or P.E.T.G. sheeting provided as a sheet or roll without the protective coating, or used on one side only. The protective coating would be left on the outside of the laminate sheets (i.e. not on the side of the sheets in contact with the resin).
Example 3
Pour Conditions
[0269] One preferred resin used in the laminate manufacture is our NC007 resin. It is a dissolved styrene unsaturated Polyester Resin.
[0270] The following Table B presents our investigations of pour conditions of the P.E.T.G. and acrylic sheeting with this resin.
[0000]
Mix
Mix
Box
Box
Resin
Cat
Set
Sample
Date
temp
hum
temp
hum
g
g
time
Result
Taiwan cast
16 Oct. 2005
20° C.
62
22° C.
67
500 g
5 g
8 hrs
Good
Acrylic
1%
no crazing
Taiwan cast
17 Oct. 2005
21° C.
58
32° C.
67
500 g
5 g
8 hrs
Not good
Acrylic
1%
crazing
Taiwan cast
18 Oct. 2005
21° C.
63
36° C.
65
550 g
4 g
8 hrs
Not good
Acrylic
0.75
crazing
Taiwan cast
19 Oct. 2005
22° C.
64
22° C.
58
550
4 g
6 hrs
Good
Acrylic
0.75
no crazing
Asia Poly cast
20 Oct. 2005
21° C.
65
22° C.
58
500 g
5 g
6 hrs
Good
Acrylic
1%
no crazing
Asia Poly cast
21 Oct. 2005
23° C.
63
36° C.
65
550 g
4 g
8 hrs
Not good
Acrylic
0.75
crazing
Asia Poly cast
22 Oct. 2005
21° C.
67
18°
58
550 g
4 g
8 hrs
Good
Acrylic
0.75
no crazing
Mitsub Japan
23 Oct. 2005
18° C.
64
18° C.
58
550 g
4 g
8 hrs
Slight
C/cast Acrylic
0.75
crazing
Mitsub Japan
24 Oct. 2005
20° C.
64
22° C.
58
500 g
5 g
8 hrs
Slight
C/cast Acrylic
1%
crazing
Australia High
25 Oct. 2005
22° C.
65
18° C.
58
550 g
4 g
8 hrs
Slight
Impact Acrylic
0.75
crazing
Australia High
26 Oct. 2005
19° C.
66
18° C.
58
500 g
5 g
8 hrs
Slight
Impact extruded
1%
crazing
Acrylic
PTEG Blue
27 Oct. 2005
20° C.
64
18° C.
58
500 g
5 g
8 hrs
Translucent
non UV
1%
Hazy
PETG Blue
28 Oct. 2005
18° C.
66
18° C.
64
550 g
4 g
8 hrs
Translucent
non UV
0.75
Hazy
Size: 300 mm × 300 mm × 2 mm thick
Temperature, mix, and times of test sample sheets
(All samples methylated spirit cleaned)
[0271] FIG. 8 a illustrates the end view of the pour apparatus. The outer edge seal/dam rubber is made up of a closed cell pvc foam sealing tape 25 mm in width with a single adhesive side 91 . After the 300 mm×300 mm sample sheet (of acrylic or PETG) 92 is prepared and cleaned the tape is laid out and cut to length, protective tape removed from one side exposing the adhesive. The tape 91 is then placed adhesive side down around outer inside edge of the sheet 92 . Joins in the tape 93 at the corners need to be sealed with Soudal High Tak sealant or equivalent polyester compatible sealant. Then Soudal High Tak sealant was applied to the exposed top surface of the pvc sealant tape giving adhesive seal for the top sheet.
[0272] A gap 94 at the two top corners is essential for the filling of resin and escape of air. The dam rubber must be compatible with the resin formula, if not the resin will seep into the dam seal drawing resin away from the sheet along the outer edges, causing delamination as illustrated in FIG. 9 . FIG. 9 shows delamination and air gap 98 due to resin soaking into the rubber dam seal 99 .
[0273] At the time of mixing care needs to be taken not to allow over speed of mixing machinery as this can over aerate the formula, if this happens a period of time is needed to allow the bubbles to surface otherwise vibration of the curing frame is necessary.
[0274] Small amounts of air may enter the formula while pouring, while rising to the surface the outer edge bubbles can at times cling to the side edges of the rubber this is not a problem as the edge is cut away after cure air bubbles within the sheet do not cause delamination or contamination but rather a cosmetic nuisance.
[0275] With reference to FIGS. 7 a, b and c (cross sectional, side and perspective views) a jig apparatus 80 was prepared for use with all samples. This enabled the sheets 81 to be held parallel whilst the resin was poured from above.
[0276] The jig was engineered from 15 mm thick Acrylic sheet 81 and braced horizontally with 10 mm ribbing 82 and held in place using nuts 83 . It was important not to over-tighten the outer edge of the jig as a concave appearance will show on the final product resulting in visual distortion to the sample.
Example 4
Annealing
[0277] As discussed previously, styrene resistance of the outer thermoplastic sheeting is an important feature of the invention. Our preferred invention uses sheeting which has an inherent styrene resistance. However it is also possible to anneal the sheeting prior to incorporation into the laminate in order to impart styrene resistance.
[0278] The following Table A relates to annealing Sample plates of Acrylic and PETG sheet sourced from various plastic sheet manufacturers, Samples sheet size, 3 mm Thick×150 long×75 mm wide, these where then cleaned with isopropyl-alcohol, placed into a cool oven on a flat non stick surface. Some samples were placed between sheets to prevent blistering or distortion. They were heated to the stated conditions and allowed to cool down over a period of 1 hour.
[0279] Samples were then re-cleaned, a dam rubber applied to the outer inner edge sealed and poured (under specific humidity and temperature conditions) with the resin formulation NC007 then placed into a preset temperature and humidity controlled environment for completion of cure.
[0000]
TABLE A
Sample
Time in oven
Temp ° C.
Results
Comments after pour
2 mm Asia Poly Cast
1
Hour
80-90° C.
Good Slight bow Slight blistering
Not poured due to blistering,
Meth cleaned
Lamp only
would give false readings
2 mm Asia Poly cast
1
Hour
80-90° C.
Good slight bow Slight blistering
As above
Non Meth cleaned
Lamp only
1 mm PTGE (blue)
I
Hour
80-85° C
Severe blistering and curling
As above
Meth cleaned
Lamp only
1 mm PTGE (blue)
45
Min
50-60° C
Blistering and curling
As above
Meth cleaned
Lamp only
1 mm PTGE (blue)
45
Min
70-80° C
Placed between sheets of glass
Slight hazing but translucent
Meth cleaned
Excellent result
colour could be added
Good bonding
1 mm PTGE (red)
UV protected
Meth cleaned
Test to be carried out plus
comparison between results of
blue non-UV PETG
1 mm PTGE (blue)
2
Hours
75-80° C
Placed between sheets of glass
Slight hazing but translucent
Meth cleaned
Excellent result
colour could be added
Good bonding
2 mm Asia Poly Cast/
1.5
Hours
95-98° C.
Placed on heat proof paper
No crazing
Meth Cleaned
Good bonding
2 mm Asia Poly Cast
1.5
Hours
95-98° C.
Placed on heat proof paper
As above
Non Meth Cleaned
2 mm Taiwan Continues
1.5
Hours
95-98° C.
Placed on heat proof paper
As above
Cast Meth Cleaned
Taiwan Continues Cast
1.5
Hours
95-98° C.
Placed on heat proof paper
As above
Non Meth Cleaned
2 mm Japanese Continues
1.5
Hours
95-98° C.
Placed on heat proof paper
As above
Cast Meth Cleaned
2 mm Japanese Continues
1.5
Hours
95-98° C.
Placed on heat proof paper
As above
Cast Meth Cleaned
Preferred sheet Shinkolite from Mitsubishi Rayon Japan
[0280] In general there was much improvement in the crazing of the samples. Results of the annealing studies showed styrene resistance can be imparted. However this is an inefficient and costly method of doing so. Thus whilst being within the scope of the invention, it is not a preferred step or characteristic.
Example 5
Forming/Folding of the Laminate
[0281] We tested a number of different combinations for their ability to thermoform. One preferred laminate consisted of two opposite outer layers of 2 mm acrylic sheet with an inner cavity barrier layer of 2 mm resin formula, forming an overall 6 mm sandwich or ply material for testing. The acrylic sheet used was Shinkolite (Mitsubishi Rayon Japan) though other suppliers can also provide suitable acrylics. The inner cavity material consisted of unsaturated polyester resin formula with 0.75 w/w (weight for weight) catalyst, e.g. 7.5 grams per litre of resin formula forming the said sandwich/ply sample, with an overall thickness of 6 mm.
[0282] Four samples of 300 mm×300 mm×6 mm thick were prepared. The pre poured sheet was poured at a room temperature of 20° C. and a humidity of 65% with curing time 6 hours, gel set time 1 hour. The sheets were placed in sealed controlled atmosphere, temperatures pre set to 20° C. Humidity 65%.
[0283] We attempted to pinpoint an optimum temperature for the maximum achievable curvature through a process of thermoforming.
[0284] Apparatus: Flat bed fan oven with an internal flat floor layer of Teflon mesh to prevent possible adhesion of test product to oven interior, having also a sealed glass inspection door for viewing.
[0285] Method: Place sample face down onto the Teflon oven base, the preheated oven temperature being 110° C., for a period of 10-12 minutes.
[0286] The sample sheet is then corner test lifted by a cotton-gloved hand. When the edge is at a stage of malleability the ply sheet is then removed by sliding a flat spatula underneath to prevent pre distortion and unnecessary exaggerated movement.
[0287] Forming method: Various Formed structures of ply MDF sheet curvature were prepared prior to sheet extraction from oven to a bench top so there is limited chance of movement as the sheet is clamped and manipulated over the chosen shape. To maximize the stress and to identify failure point of the experiment, a 45° angle with various degrees of sharpness at curvature was used.
[0288] The hot sheet was then directly placed over the mould and manipulated by hand to form and take the general shape of the mould, then at the latter stage clamped, secured and set in place to re cure. This is illustrated in FIG. 6 . The heat source 71 is a double sided heat source applied to the laminate 70 . Single sided heating is not ideal for our laminates.
[0289] Results of forming:
No crazing Delaminating centrally and along outer edging only occurred when the sample sheet was left to form and hold the intended shape without pressure and forced forming.
[0292] Results: We found that in all cases using severe curvature (45 degrees or more) it is necessary to have a complete marrying of the ply forms equal to outer e.g. having the sample sheet pressed between equal outer curvatures therefore the sample sheet becomes a cavity between the outer moulds, a pressure of 2 kilos is sufficient. It is preferably to allow a time of between 12 to 15 minutes before release.
[0293] Where in the foregoing description reference has been made to elements or integers having known equivalents, then such equivalents are included as if they were individually set forth.
[0294] Although the invention has been described by way of example and with reference to particular embodiments, it is to be understood that modifications and/or improvements may be made without departing from the scope or spirit of the invention.
[0295] In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognise that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group. | A self supporting curved laminate product resulting from curving of a planar precursor, wherein the planar precursor is a self supporting laminate of two sheets of an acrylic thermoplastic, or of sheets including an acrylic thermoplastic, spaced by, but attaching to, an interposed thermoset polyester system, and wherein curving has involved heating of the laminate sufficient to allow its curving without any substantial degradation of the lamination or its component layers. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 10/350,016, filed Jan. 24, 2003, which claims priority to German Patent Application No. 102 05 061.9, filed Feb. 7, 2002, the priority of which is claimed herein. The contents of the foregoing applications are incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
The invention relates to a device on a spinning preparation machine, for example a carding machine or draw frame, involving the discharge of a sliver with a discharging device and depositing of the sliver on a support. The discharge device and the support can be moved relative to each other and the sliver (sliver bundle) deposited on the support can be fed to a processing machine downstream.
In a known device shown in European Patent Document EP 0 457 099, a sliver produced by a sliver delivery machine (a carding machine or draw frame) is deposited in a spinning can with a rectangular cross-section. In the process, the can moves back and forth within the depositing region. Once the can is filled with the ring-shaped deposited sliver, the can is moved out of the depositing region and is supplied to a downstream-connected device. A plurality of filled cans are stored in intermediate storage areas and the cans are supplied from there to, for example, a spinning machine. The cans are transported between the storage area and the spinning machine with the aid of a carriage. One disadvantage of the device is the high equipment cost for the system. A plurality of empty cans must be supplied to the depositing region of the machines for depositing the sliver and the cans filled with the sliver must then be removed again from the depositing region. Added to the expense for the structural adaptation of the machine to the can and the handling involved with the additional conveying or transport expenditure for the cans is the considerable expenditure for the cans themselves (purchase, storage, repair and the like). Finally, the sliver must also then be removed again from the cans at the downstream-connected processing machine.
SUMMARY OF THE INVENTION
It is an object of the invention to create a device of the aforementioned type that avoids the above-mentioned disadvantages. In particular, the device should permit the easy displacement of the deposited sliver (sliver bundle) in the depositing region and/or out of the depositing region of the machine, thus making possible a considerable reduction in the equipment expenditure for the system.
Embodiments of the invention provide a device on a spinning preparation machine for receiving a sliver from a discharge device of the spinning preparation machine and transporting the sliver to a downstream machine, the spinning preparation machine having a depositing region, the device comprises a support for receiving the sliver deposited from the discharge device in the depositing region; and a moving device for moving the deposited sliver relative to the discharge device in the depositing region for forming a free standing sliver bundle, and for moving the free standing sliver bundle out of the depositing region for transport to a downstream machine.
Other embodiments of the invention provide a method of depositing and transporting a sliver bundle. The method comprises discharging a sliver from a discharge device of a spinning preparation machine; depositing the discharged sliver on a movable support in a discharge region of the spinning preparation machine; moving the support back and forth inside the depositing region relative to the discharge device to create a free standing deposited sliver bundle on the support; and moving the support with the free-standing sliver bundle to a downstream machine.
Sliver processing can be simplified considerably due to the fact that the deposited sliver (sliver bundle) as such can be moved during the sliver deposit with mechanical means within the depositing region, as well as out of the depositing region following the sliver deposit. Also, the removal of the slivers from cans or the like at the downstream-connected processing machine, for example a spinning machine, is omitted. Added to this is a large reduction in the equipment expenditure for the system. A structural adaptation of the sliver delivery machine (draw frame, carding machine) to a can is not necessary. In particular, the full scope of expenditure required for purchasing, storing and repairing a large number of cans and the like is avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained below in further detail with the aid of exemplary embodiments shown in the drawings, wherein:
FIG. 1 a is a schematic side elevation view of a draw frame with a device according to the invention, using a carriage for the sliver deposit, shown in one end position below a rotating plate;
FIG. 1 b shows the device according to FIG. 1 a , but in the other end position below the rotating plate;
FIG. 1 c shows the device according to FIGS. 1 a and 1 b , but outside of the sliver-depositing device;
FIG. 2 is a perspective view of a draw frame with a sliver depositing device according to the invention using a conveyor belt for the sliver deposit;
FIG. 3 is a schematic side elevation view of a carding machine with a device according to the invention;
FIG. 4 a is a top view of a sliver bundle deposited freely on the top of a carriage;
FIG. 4 b is a side elevation view of the sliver bundle shown in FIG. 4 a;
FIG. 5 a is a side elevation view of an embodiment of the invention using a conveyor belt that can be raised and lowered and functions as sliver deposit and removal device during the depositing operation;
FIG. 5 b is a side elevation view of the embodiment shown in FIG. 5 a during the removal operation;
FIG. 6 is a side elevation view of an embodiment of the invention having a thrust device fox the sliver bundle changeover; and
FIG. 7 is a side elevation view of an embodiment of the invention having a lifting device and extended conveyor belt which function simultaneously for traversing and removal.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of a high-performance draw frame 1 (autoleveller) manufactured by the company Trützschler, Mönchengladbach, Germany, such as the high-performance draw frame HSR 1000, in a schematic side elevation view. Individual slivers are fed from a can into the drawing unit that is not shown herein. In this unit, the slivers are drawn and combined to form a single sliver, which exits the unit. The sliver then passes through a rotating plate 2 and is subsequently deposited as a ring-shaped sliver bundle 4 on a support, for example a carriage 3 with rectangular top surface 3 a , which moves back and forth in the direction of arrows A and B. In this example, the rotating plate 2 rotates about fixed axis 102 . The carriage 3 is operated with a controllable drive motor 5 , which is connected to an electronic control and regulating device 6 , for example a machine control. A cover plate 10 for the sliver depositing device (sliver coiler arrangement) is attached to a support plate 7 . The arrow F indicates the operating direction (fiber-material flow) within the draw frame. The rotating plate 2 delivers the sliver bundle 4 in an essentially vertical direction. The depositing region is indicated by the reference number 8 , while the region outside of the depositing region 8 is indicated by the reference number 9 . The depositing region 8 comprises the drawing distance a according to FIG. 1 b.
Carriage 3 moves back and forth horizontally below the rotating plate 2 while the sliver 4 is deposited. One end position of carriage 3 is shown in FIG. 1 a while the other end position is shown in FIG. 1 b . As a result, the sliver bundle 4 is also moved back and forth below the rotating plate 2 in the direction of arrows A and B. Once it reaches the end position shown in FIG. 1 a , the carriage 3 moves in the direction of arrow C, wherein the carriage 3 is accelerated, then driven with a steady speed and subsequently decelerated again. After reaching the end position shown in FIG. 1 b , the carriage 3 moves back in the direction of arrow D, wherein the carriage 3 is accelerated, then driven with a uniform speed and subsequently decelerated once more. The control unit 6 in connection with the drive motor 5 implements the back and forth movement.
The speed-controlled electric motor 5 drives the carriage 3 with a non-jolting or nearly non-jolting speed. The acceleration and deceleration, in particular, occur without jolting or nearly without jolting while the speed between the acceleration and deceleration remains uniform. The sliver bundle 4 thus remains stable during the back and forth movement in the depositing region 8 , according to FIGS. 1 a and 1 b , as well as during the movement out of the depositing region 8 according to FIG. 1 c . The movements are controlled in such a way that the highest possible production speed is realized, without slippage or tilting of the sliver bundle 4 .
While the sliver is being deposited, the control unit 6 (see FIG. 1 a ) controls the back and forth movement of the carriage 3 to create a stable sliver bundle 4 . In one embodiment, the rotating plate 2 rotates at a fixed location and discharges the sliver onto the carriage 3 at a constant charging pressure. The constant charging pressure is generated by discharging the sliver at a constant feed rate per material layer of sliver. For instance, the rotating plate 2 discharges sliver onto the carriage 3 at a constant rate so that each layer of sliver rings deposited during either the forward or backward movement receives a substantially uniform amount of sliver. Having a constant amount of sliver per layer promotes the stability of the sliver bundle 4 .
The rate of the back and forth movement of the carriage 3 is also controlled to increase the stability of the sliver bundle 4 . As the carriage 3 reaches the reversal point at either end of the back and forth movement, the control unit 6 decelerates the carriage 3 as the carriage 3 approaches a seam area 402 a or 402 b of the sliver bundle 4 and accelerates the carriage 3 as the carriage leaves the seam area 402 a or 402 b . In between the seam areas 402 a and 402 b on either side of the sliver bundle 4 , the control unit 6 controls the carriage 3 to have a constant speed. The seam area 402 a or 402 b is the location on either end of the sliver bundle 4 where the sliver rings deposited on the carriage 3 do not completely overlap (see FIG. 4 a and FIG. 4 b ). The seam area 402 a or 402 b occurs shortly before the reversal point of the movement of the carriage 3 at either end of the sliver bundle 4 . In contrast, in the non-seam area 404 , during either the forward or backward movement of the carriage 3 , the back edge of each sliver ring is deposited on top of the front edge of a previously deposited sliver ring.
To account for less sliver being deposited in the seam area 402 a or 402 b , the control unit 6 decelerates the carriage 3 so that more sliver may be deposited in the seam area 402 a or 402 b and accelerates the carriage 3 to a constant speed in the non-seam area 404 . The deceleration of the carriage 3 increases the amount of sliver deposited in the seam area 402 a or 402 b since the rotating plate 2 discharges the sliver at a constant rate independent of the movement of the carriage 3 . When the carriage 3 decelerates, more sliver may be deposited at that location to account for the non-overlapping rings of sliver near the reversal points. The non-uniform speed of the carriage 3 permits a substantially uniform amount of sliver to be deposited at both the seam area 402 a or 402 b and the non-seam area 404 of the sliver bundle 4 for each layer of sliver deposited in the back and forth movement of the carriage 3 . The non-uniform speed of the carriage 3 also provides substantially uniform density of the sliver at all locations within the sliver bundle 4 . This uniform density of sliver permits the sliver bundle 4 to be formed stably on the carriage 3 and allows the sliver bundle 4 to be accelerated back and forth while minimizing the possibility that the canless, laterally unsupported, sliver bundle 4 will become unstable and topple over.
Once the depositing of the sliver bundle 4 on the surface 3 a is complete, the carriage 3 together with the sliver bundle 4 moves in the direction of arrow E out of the sliver-depositing device (sliver coiler arrangement). The control unit 6 controls the movement of the carriage 3 for the changeover from the back and forth movement (arrows A, B) during the sliver deposit to the movement (arrow E) out of the depositing region 8 .
In the embodiment of the invention shown in FIG. 2 , round cans 44 are arranged below the sliver intake 45 and the feed slivers 46 are pulled off via rollers and fed into the draw frame. Following the passage through the draw frame 11 , the drawn sliver 12 arrives at the rotating plate 2 and is deposited in rings on a rectangular plate 13 . The plate 13 is arranged on an endlessly circulating conveyor belt 14 , which is driven by a controllable electric motor 15 that ensures the back and forth movement of the conveying belt 14 , the plate 13 and the sliver bundle 4 in the direction of arrows G, H. In this example, the conveyor belt 14 is at least twice as large as the maximum movement of the sliver bundle 4 in the horizontal direction in the depositing region. The electric motor 15 is connected to an electric control and regulating device 6 .
FIG. 3 shows a carding machine, for example a Trützschler high-performance carding machine model DX 903, comprising a feed roller 16 , feed table 17 , licker-ins 18 a , 18 b , 18 c , main carding cylinder 19 , doffer 20 , stripping roll 21 , crushing rolls 22 , 23 , sliver guide element 24 , web trumpet 25 , withdrawing rolls 26 , 27 , traveling flats 28 , 14 and sliver coiler arrangement 29 . Curved arrows indicate the rotational directions of the rollers. The carding machine operating direction is shown by arrow I. A housing 31 with therein-disposed rotating plate 2 is located above the cover plate 30 for the sliver coiler arrangement. A sliver support is embodied as carriage 3 , which is provided with a rectangular plate 3 a on the top. During the sliver deposit on the rectangular plate 3 a , the carriage 3 is moved back and forth in the direction of arrows K, L with the aid of a drive mechanism, for example the controlled motor 32 .
FIG. 4 a shows a view from above of a ring-shaped sliver bundle 4 , deposited freely on the top 3 a of the carriage 3 . FIG. 4 b shows a view from the side of the sliver bundle 4 that is positioned freely on the carriage 3 . As depicted in FIGS. 4 a and 4 b , the sliver bundle 4 is formed into a rectangular shape of sliver rings. The rectangular shape of the sliver bundle 4 is formed by the manner in which the sliver is deposited. The rotation of the rotating plate 2 as the sliver is discharged forms a layer of overlapping rings of sliver on a receiving surface of the carriage 3 , and the movement of the carriage 3 back and forth under the control of the control unit 6 adjusts the locations at which the sliver rings are formed on the receiving surface. The movement of the carriage causes the deposited rings to be offset from one another and to partially overlap on the receiving surface of the carriage 3 , which creates the substantially rectangular shape of the sliver bundle 4 when viewed from the top. At either end of the sliver bundle 4 , the changing of the direction in the back and forth movement of the carriage 3 leaves the sliver bundle 4 with rounded ends for the rectangular shape, as best shown in FIG. 4 a . In one embodiment, the rectangular shape of the sliver bundle 4 is advantageous since it promotes the stability of the sliver bundle, as compared with conical or cylindrical shaped sliver bundles.
FIG. 5 a illustrates a further exemplary embodiment of the movement of the devices according to the claimed invention. FIG. 5 a shows a carriage 3 with a holding device 34 a , 34 b , for example a post, arranged on the top. A conveyor belt 33 is attached to this holding device, such that it can be displaced up or down in the direction of arrows M, N. In this example, the conveyor belt 33 has a length substantially equal to a maximum movement of the sliver bundle in the horizontal direction in the depositing region. The sliver bundle 4 is deposited on the upper belt section 33 a of the conveyor belt 33 . During the sliver deposit, the carriage 3 moves back and forth in the direction of arrows C, D. After reaching each respective end position (compare FIGS. 1 a , 1 b ), the conveyor belt 33 is displaced downward in the direction M by as much as a sliver thickness, for example 10 mm, with the aid of a drive motor (not shown herein) to create a substantially constant space for the next layer of sliver material to be deposited into. The substantially constant space refers to the temporary area between the top of the laterally unsupported sliver bundle 4 and the bottom of the rotating plate 2 . This space is immediately filled with new sliver material to create a constant filling pressure for each layer of sliver deposited. The substantially constant space permits only a substantially constant amount of area for sliver to be deposited for each layer of sliver. A layer of sliver may be considered the amount of sliver deposited between a single pair of movement reversal points for the carriage 3 (i.e., from the point at which the movement of the carriage 3 changes direction until the next reversal point). Discharging the sliver into the substantially constant space allows a substantially uniform density of sliver to be formed at all locations within the sliver bundle 4 , which promotes stability of the sliver bundle 4 .
As shown in FIG. 5 b , when the sliver depositing operation is completed, the upper belt section 33 a is moved in the direction R, for example with a controlled drive motor (not shown herein), so that the sliver bundle 4 , 4 ′ is pushed onto a secondary, essentially flat supporting surface 35 , for example a transporting tray. The edge of the support surface 35 , which faces the carriage 3 for example, is beveled, rounded or has a similar shape.
FIG. 6 illustrates another exemplary embodiment of an apparatus according to the present invention. As shown, a lifting base 36 , for example a platform, is arranged on the carriage 3 , which can be attached to holding elements in the manner shown in reference DE 44 07 849 A1. The lifting base 36 can be adjusted in the direction of arrows O, P by means of lifting elements 42 a , 42 b , for example controlled pneumatic cylinders. The carriage 3 is provided with a support element 37 , for example a post. A sliding device 38 is attached to this post via a suitable, controlled drive element 39 , for example a pneumatic cylinder, a spindle drive, or the like. Once the sliver bundle 4 is deposited completely on the surface of the lifting base 36 , the sliding device 38 is moved in the direction of arrow S toward the sliver bundle 4 . The sliver bundle 4 is thus pushed from the lifting base 36 onto the support surface 35 through direct pressure exerted by the sliding device 38 . The support surface 35 rests on a frame 40 or the like, can be removed from the surface of the frame 40 together with the sliver bundle 4 ′ and can be supplied to a downstream-connected processing device, for example a spinning machine, or to a storage area.
FIG. 7 shows a lifting platform 41 , which can be lifted and stopped in the direction of arrows T, U by means of lifting elements 42 a , 42 b , for example controlled pneumatic cylinders. A conveyor belt 43 is provided on the surface of lifting platform 41 , the belt sections of which can be moved in the direction of arrows X, Y. The drive and control of the conveyor belt 43 correspond to the type shown in FIG. 2 . During the depositing operation, the upper belt section 43 a is moved back and forth underneath the rotating plate 2 , in the direction of arrows X, Y. Once the sliver is deposited as sliver bundle 4 on the upper belt section 43 a , a control unit 6 (see FIG. 2 ) controls a drive motor 15 (see FIG. 2 ) in such a way that the upper belt section 43 a moves the sliver bundle 4 out of the depositing region 8 underneath the rotating plate 2 and places it onto a support surface 35 .
The invention has been described in detail with respect to preferred embodiments and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. The invention, therefore, is intended to cover all such changes and modifications that fall within the true spirit of the invention. | A device is provided on a spinning preparation machine for receiving a sliver from a discharge device of the spinning preparation machine and transporting the sliver to a downstream machine, the spinning preparation machine having a depositing region. The device has a support for receiving the sliver deposited from the discharge device in the depositing region, and a moving device for moving the deposited sliver relative to the discharge device in the depositing region for forming a free standing sliver bundle, and for moving the free standing sliver bundle out of the depositing region for transport to a downstream machine. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority of German Application No. 10 2011 007 082.6, filed Apr. 8, 2011, the disclosure of which is hereby incorporated by reference in its entirety into this application.
FIELD AND BACKGROUND OF THE INVENTION
The invention relates to a winding shaft for a roller blind system with a main body for holding a rolled up planar structure that can be unwound from the winding shaft, where the main body takes the form of a partial cone around a winding shaft axis.
Generic winding shafts are known to the pri- or art. They are used for roller blind systems in motor vehicles where it is desirable for a planar structure stowed on the winding shaft not to be unrolled from the winding shaft in a straight line, but to follow a slightly curved path. The outsides of these generic winding shafts have the form of a partial cone, where opening angles of less than 10° are usually employed.
The manufacture of generic winding shafts has until now represented a problem with no satisfactory solution. The effort required to produce a conically widened plastic body is comparatively high, and its stability is not satisfactory. For this reason, use is instead most often made of cylindrical base bodies onto which a planar structure is glued and which, due to an approximately triangular form of the planar structure when glued, gives the winding shaft an approximately conical form. The use of hollow cylindrical shafts as a base body, onto the surface of which plastic is sprayed in order to achieve the shape of a cone or partial cone, is also known.
SUMMARY OF THE INVENTION
The object of the invention is to provide an alternative design for a winding shaft that is advantageous from the points of view of the effort of manufacture and of its functional properties.
This is achieved in accordance with the invention in that the main body of a generic winding shaft is formed as a hollow metal part shaped as a partial cone.
It has been found that if appropriate manufacturing methods are used, the direct manufacture of the main body in the shape of a partial cone as a hollow, metal part is easy to handle and furthermore leads to superior properties of the winding shaft in respect of its vibration properties and its stiffness. A winding shaft in accordance with the invention thus comprises a hollow metal part of this type shaped as a partial cone, which preferably itself offers, in its exterior surface, that surface onto which the lowest layer of the planar structure can be wound directly.
It is considered advantageous if not only the external diameter of this hollow metal body has the form of a partial cone, but also its interior surface. As a result, the mass is lower than that of a winding shaft with a cylindrical inner surface. It may however be seen as particularly advantageous if the conicity of the exterior surface and the inner surface of the winding shaft are designed such that the wall thickness of the main body changes along the direction of the winding shaft axis. It has been found that a variable wall thickness of the main body of this sort provides the advantageous possibility of being able specifically to give the main body increased stability and improved vibrational properties. It is particularly advantageous here if the wall thickness increases from a first end of the main body of greater external diameter down towards a second end of the main body of smaller diameter. As a result, the mass distribution of the winding shaft is more evenly distributed. The torsional stiffness is also increased in the region with the smaller external diameter.
In order to achieve a low mass, it is advantageous if the main body is made of aluminium or of an aluminium alloy.
The outer surface in particular of a winding shaft in accordance with the invention can be manufactured by metal-cutting manufacturing methods. A variable internal diameter too can be achieved through metal-cutting manufacture, for instance by step-drilling using drills of various diameter.
It is nevertheless advantageous if the main body is shaped as a partial cone starting from a cylindrical metal tube by means of a forming process, particularly preferably by means of a hot-forming process and/or preferably through blows made with a hammer along the central axis of the metal tube.
This way of manufacturing winding shafts or their main bodies in accordance with the invention is of considerable economical advantage when winding shafts in accordance with the invention are mass produced. This avoids or minimizes the metal-cutting manufacturing steps. The main step in machining is performed by forming the originally cylindrical metal tube, which is preferably subjected to hammer blows while a rotary movement of the metal tube is being executed, leading to a reduction in the external diameter of the metal tube. It is also of particular advantage here that the required increase in the wall thickness in the region of smaller external diameter is in this way already achieved without the need to perform an additional step for this purpose. In those areas where the external diameter is significantly reduced as a result of radial blows, the wall thickness is also increased. Assuming that the blows applied for the forming process only result in an insignificant increase in the length of the main body, this even leads to a largely consistent mass distribution of the main body along the winding shaft.
This production method for making a winding shaft in accordance with the invention or its conical main body is itself also to be understood as part of the invention.
The invention moreover concerns a roller blind system having a winding shaft axis rotatably mounted about a winding shaft axis as well as a flexible planar structure, one edge of which is fastened to the winding shaft. The winding shaft is here designed as described above.
It is of particular advantage here if a coil spring is mounted inside the winding shaft, this coil spring being preferably arranged, relative to a centre of the winding shaft, offset towards the end with the greater external diameter.
This design exploits the fact that in the region with the greater external diameter, the internal diameter of a winding shaft in accordance with the invention is also usually greater, so that the space needed to house the coil spring is available here. One end of the coil spring is connected directly or indirectly to the main body of the winding shaft. Its opposite end is designed to be attached to a mounting part of the roller blind system that has a fixed location during operation.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the invention emerge are found not only in the claims but also in the following description of a preferred embodiment of the invention.
FIG. 1 shows a sectional view of a roller blind system in accordance with the invention with a winding shaft in accordance with the invention and
FIG. 2 shows a separate illustration of the main body of the winding shaft of the roller blind system according to FIG. 1 .
DETAILED DESCRIPTION
FIG. 1 illustrates a roller blind system 10 in accordance with the invention with a winding shaft 20 in accordance with the invention.
This roller blind system 10 is designed in particular for use in the interior of a vehicle. Due to its special feature in accordance with the invention, the conical shape of the winding shaft 20 , it is particularly useful for shading systems for the side windows of the vehicle.
The roller blind system 10 has as the primary components a winding shaft 20 with a main body 22 as well as caps 28 at the ends. A planar structure 30 is partially wound onto the outer surface of the main body 22 . As can be seen from the partially unwound area 30 a of the planar structure 30 , the latter is not rectangular, but has a shape approximating to that of a circular segment. Planar structures with this shape are usual for the side windows as mentioned of the vehicle.
The main body 22 that serves to hold the planar structure, which is represented separately in FIG. 2 , is adapted to this shape of the planar structure and is designed as a hollow metal tube with a tapering external diameter. This external diameter 24 is at its maximum at a first end 22 a , and tapers from there continuously down to an opposite, second end 22 b . The internal diameter 26 of the main body 22 also tapers, but to an even greater extent, so that the thickness of the walls in the region of the first end 22 a is significantly less than it is at the opposite end 22 b . As a result, the mass distribution of the main body 22 made of aluminium remains substantially constant along the central axis 2 . That part whose external diameter is greater in the direction of the end 22 a therefore does not have a greater mass corresponding to the increased external diameter, relative to a defined unit of length, in the direction of the central axis 2 .
As can be seen from FIG. 1 , the two ends of the main body 22 , which is preferably between 20 cm and 50 cm in length and whose opening angle is preferably greater than 0° and less than 10°, are closed by means of the aforementioned end caps 28 . Bearing holes 28 a are provided in these end caps 28 , through which protrude axle stubs 40 fixed to the vehicle. Whereas the axle stub 40 at the narrow end 22 b merely has the function of a bearing, the axle stub 40 at the opposite end 22 a also functions as the thrust bearing for a coil spring 50 . One end of this coil spring is fastened to the axle stub 40 and the opposite end is inserted into a recess in the main body 22 , so that the coil spring 50 is twisted as the planar structure 30 is unwound.
In order to manufacture the winding shaft in accordance with the invention, in particular the main body, a cylindrical metal tube is first used as a blank workpiece. It has an external diameter equalling or greater than the external diameter at the end 22 a of the main body. This cylindrical tube is tapered by blows applied radially in the direction of the central axis 2 , where the blows generated by a tool preferably under automatic control are distributed over the cylindrical metal tube circumference. The cylindrical metal tube is preferably rotated for this purpose during its machining and the associated tapering while being particularly preferably moved axially, continuously or in steps. This manufacturing method results in the greater wall thickness at the end of 22 b compared with the end 22 a , without the necessity of taking additional steps. | A winding shaft for a roller blind system with a main body for holding a rolled up planar structure that can be unwound from the winding shaft, wherein the main body takes the form of a partial cone around a winding shaft axis. The main body is formed as a hollow metal tube shaped as a partial cone. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for making flexible bands, and more particularly to an apparatus for making flexible fabric bands for use in apparel.
Machines for making flexible bands, and particularly elastic fabric bands for use in the manufacture of apparel, in which a strip of fabric material is measured and cut and the free ends sewn together, are known in the art.
Moreover, the concept of feeding an elongated strip of fabric material beneath a sewing machine by clamping its lead edge and pulling the strip beneath the sewing machine, subsequently deflecting a portion of the strip beneath the sewing machine to form a measured loop, clamping the end portions, cutting the trailing end portion of the deflected loop, placing the trailing and leading edges of the loop upon the sewing machine work plate, and subsequently stitching the overlapping ends of the deflected loop together and ejecting the completed loop, is known in the art.
However, the mechanism for measuring or forming the deflected loop presently in use, includes a transverse measure rod which is mounted on the free end of an elongated pivotally mounted arm. The adjustment of the pivotal sweep of this arm in order to permit the formation of deflected loops of various lengths for the manufacture of different sizes of fabric bands, is somewhat complicated, and requires an excessive amount of down-time for each length adjustment. Moreover, the pivotally mounted measuring arms now in use, occupy an extensive amount of space for carrying out the function of measuring the length of the deflected loop.
Furthermore, the ejection mechanism in current use for ejecting and discharging the completed bands from the sewing machine utilize a pivotal ejection arm supporting a hook for engaging and removing the completed band through the swinging motion of the ejection arms. Not only does this swinging arm ejection mechanism occupy an unnecessary amount of space, but also the cycle of feeding and pulling the next strip of fabric into its measuring position must be delayed until the previous band is completed and removed from the sewing machine, thus, limiting the number of bands that can be made per unit of time. Furthermore, a swinging ejection mechanism must swing through greater areas to remove bands of greater length, resulting in timing and adjustment problems for bands of different lengths.
Heretofore, in the feeding the the fabric strip toward the measuring and sewing stations, some of the fabric strip portions, which are wrinkled or twisted, must be manually straightened, requiring unnecessary down-time.
SUMMARY OF INVENTION
It is therefore an object of this invention to provide an apparatus for making a fabric band basically utilizing the original concept of feeding and pulling a flexible fabric strip through a measuring station beneath a sewing station, deflecting the fabric strip to form a deflected open loop of a pre-determined length, clamping and cutting the end portions of the open loop and placing the end portions upon the sewing plate in an overlapping position for stitching by the sewing machine, and then removing the completed band from the sewing machine.
However, the measuring mechanism utilized in this apparatus is considered unique in its structure and function, and is also provided with an adjustment mechanism for quickly and easily adapting the measuring mechanism for measuring deflected loops of various desired lengths.
Furthermore, this apparatus contemplates a loop extraction mechanism for withdrawing the clamped open loop from the measuring path of the fabric strip to permit the initiation of the next measuring cycle while the first loop ends are being stitched, thereby condensing the length of each band cycle to improve the production of the flexible fabric bands.
This apparatus is particularly adapted for the fabrication of flexible elastic fabric bands which are to be used in various types of apparel, such as underwear and outer wear for both men and women. Accordingly, this apparatus utilizes a tensionless feed mechanism for feeding the elastic fabric strips, and also for measuring the strips, without any perceptible elongation of the elastic strips.
The apparatus also includes an ejection clamping mechanism of novel structure, which initially places the free ends of the open loop into their final position for securing or stitching by the sewing needle and for holding these ends in place while stitching, as well as for removing the completed loop from the sewing station and for discharging the completed loop to a discharge station, such as a receptacle.
The apparatus also includes a unique oscillating feed mechanism for straightening the fabric strip before it is measured.
In this apparatus both the measuring mechanism and the ejection mechanism have linear or reciprocable motions, instead of pivotal motions, for more positive action and to minimize space requirements.
Other advantages of this apparatus will become apparent from the detailed description of the apparatus.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic front elevation of the apparatus, made in accordance with this invention, with the measuring device in its operative position for forming a measured deflected loop in the fabric strip;
FIG. 2 is a section taken along the line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary side elevation of the pull clamp mechanism;
FIG. 4 is a left end elevation of the pull clamp mechanism disclosed in FIG. 3;
FIG. 5 is an end elevation of the knife mechanism, schematically disclosed in FIG. 1;
FIG. 6 is an enlarged, fragmentary front elevational view of the loop measuring device;
FIG. 7 is a section taken along the line 7--7 FIG. 6;
FIG. 8 is a fragmentary end elevational view of the loop extraction mechanism disclosed in FIG. 1, with portions broken away;
FIG. 9 is a front elevational view of the loop extraction mechanism disclosed in FIG. 8, with portions broken away;
FIG. 10 is a top plan view taken along the line 10--10 of FIG. 9;
FIG. 11 is a fragmentary section taken along the line 11--11 of FIG. 8;
FIG. 12 is a fragmentary front elevational view of the loop loading mechanism;
FIG. 13 is a fragmentary right end elevation of the loop loading mechanism disclosed in FIG. 12;
FIG. 14 is a top plan view of the loop loading mechanism disclosed in FIG. 12;
FIG. 15 is a fragmentary top plan view of the band ejection mechanism;
FIG. 16 is a front end elevational view of the ejection mechanism disclosed in FIG. 15;
FIG. 17 is a fragmentary right end elevational view of the ejection mechanism enclosed in FIG. 15;
FIG. 18 is a section taken along the line 18--18 of FIG. 15;
FIG. 19 is a fragmentary top plan view of the portion of the ejection mechanism disclosed in FIG. 18, with portions removed;
FIG. 20 is an enlarged fragmentary front elevational view of the oscillating feed mechanism;
FIG. 21 is a right end elevation of the oscillating feed mechanism disclosed in FIG. 20; and
FIG. 22 is a fragmentary top plan view of the oscillating feed mechanism disclosed in FIG. 20.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in more detail, FIGS. 1 and 2 disclose an apparatus 20 for making a flexible band 21 (FIG. 2) from an elongated strip of flexible material, such as an elastic fabric strip 22.
The machine or apparatus 20 includes a frame 23 having a horizontally disposed longitudinal feed track or guide 24, shown at the left hand side of the frame 23 in FIG. 1.
Fixed to and above the frame 23 is a conventional sewing machine head 25 having a stitching station 26 including a work plate 27 adapted to support the fabric strip 22 for stitching, and a vertically reciprocable needle 28 adapted to carry a thread reciprocably through the fabric strip in a known manner.
An arm 29 extending from the left side of the frame 23 as viewed in FIG. 1, supports a pair of feed rollers 30 adapted to be driven by a motor 31 for feeding a fabric strip 22 toward the frame 23 from a fabric strip source, such as the fabric supply roll 32. The fabric strip 22 is guided through an oscillating feed mechanism 33 and over the transverse guide bars or rollers 34 and 35 to the feed rollers 30.
From the feed rollers 30, the fabric strip 22 passes through a guide loop 36 on the free end of an elongated pivoted tension arm 37 operatively connected to an electric switch 38 electrically connected to the feed motor 31 for starting and stopping the feed motor 35. From the guide loop 36, the fabric strip passes over the guide track 24, where it is held in a stationary position by the pivotally mounted pawl 40.
Thus, the tension arm 37 is adapted to maintain a tensionless or slack loop 41 in the fabric strip 22 by controlling the actuation of the feed motor 31. As the loop 41 gets deeper or larger, the weight of the tension arm 37 will actuate the switch 38 to stop the feed motor 31 to prevent the accumulation of anymore fabric within the slack loop 41. However, as the fabric strip 22 is drawn toward the right of FIG. 1, over the guide track 24 to reduce the size of the loop 41, the tension arm 37 will be raised actuating the switch 38 to re-start the feed motor 31, feeding more of the fabric strip from the supply roll 32 to the slack loop 41. In this manner, the fabric strip 22, particularly an elastic fabric strip, for which the apparatus 10 is particularly adapted, will be fed and transferred with a minimum of tension, to prevent stretching or expansion of the fabric strip 22.
As the fabric strip 22 passes over the guide track 24, it will move past a cutting station 42 including a stationary lower knife blade 43 and a moveable upper knife blade 44, both extending transversely of the feed path of the fabric strip 22.
An example of one form of cutting mechanism 45 which can be utilized at the cutting station 42 is disclosed in FIG. 5. The cutting mechanism 45 includes the stationary lower blade 43 adapted to cooperate with the upper moveable blade 44 which is pivotally mounted about the pivot pin 46 and is integral with a pivotal knife arm 47 connected to a piston rod or plunger 48 controlled by the pneumatic cylinder 49.
As disclosed in FIGS. 1, 3 and 4, a pull-clamp mechanism 50 is mounted on the frame 23 on the opposite side of the sewing head 25 from the fabric guide 24 and in substantial horizontal alignment therewith. The clamp mechanism 50 may include a C-shaped clamp frame 51 having an upper fixed jaw 52. Opposing the upper jaw 52 is a lower moveable jaw actuable by a fluid motor or cylinder 54 supported in the lower part of the clamp frame 51. Actuation of the fluid cylinder 54 causes the lower clamp jaw 53 to move toward and engage the upper fixed clamp jaw 52.
The C-shaped clamp frame 51 is fixed to a piston rod 55 actuable by a fluid cylinder 56. The clamp frame 51 is also provided with an elongated guide rod 57 slideable in the guide cylinder 58. An adjustment stop screw 59 in the rear of the guide cylinder 58 provides a means for adjusting the longitudinal horizontal travel of the clamp frame 51.
The pull-clamp mechanism 50 may be fixed to the frame 23 by means of the mounting plate 60.
A measuring device of mechanism 61 is provided directly below the sewing machine head 25 and longitudinally between the cutting station 42 and the pull-clamp mechanism 50. The function of the measuring mechanism 61 is to deflect downward a portion of the fabric strip 22 pulled into the measuring path P beneath the sewing head 25 by the pull-clamp mechanism 50 in order to measure a pre-determined deflected open loop 62 (FIGS. 1 and 6).
The measuring mechanism 61 includes a vertically disposed and fixed guide rod 63 upon which vertically travels a guide member or guide block 64. The guide block 64 supports an upstanding arm 65 to which is fixed a forwardly projecting, horizontally disposed, measure rod 66. The measure rod 66 is located directly below the sewing machine head 25 and in substantial vertical alingment with the axis of the sewing needle 28. In its inoperative upper position, the transverse measure rod 66 lies above and transversely over the measuring path P of the fabric strip 22. However, when the measure rod 66 is forced downward, it engages and deflects downward a portion of the fabric strip 22, to form the open loop 62. The depth of the loop 62 is determined by the downward travel of the measure rod 66.
In order to vertically reciprocate the measure rod 66, the guide block 64 is provided with a bracket 67 fixed to the opposite ends of a chain or cable 68, or other inelastic flexible linear member, trained about the upper and lower pulleys or sheaves 69 and 70 (FIG. 6). The cable 68 extends longitudinally through the fluid cylinder 72 where it is fixed to a piston 73 adapted to reciprocate within the cylinder 72. When hydraulic or pressurized fluid is introduced into the cylinder 72 through the lower inlet conduit 74, the piston 73 is driven upward to drive downward the measure rod 66. Simultaneously the fluid on the upper side of the piston 73 is exhausted through the upper conduit 75. By reversing the flow of hydraulic fluid through the conduits 75 and 74 and the cylinder 72, the measure rod 66 is raised to its upper inoperative position shown in solid lines in FIGS. 6 and 7.
Both the hydraulic cylinder 72 and the vertical guide rod 63 are fixed between an upper portion of the machine frame 23 and a lower frame member 76.
A pair of guide rails 77 and 78 are also fixed between the upper portion of the machine frame and the lower horizontal frame member 76 to provide a vertical guide slot therebetween in vertical alignment with the travel of the horizontal measure rod 66.
The lower limit of travel of the measure rod 66 is determined by the adjustable stop member 80, which includes a rear clamp plate 81 having a stop flange 82 and a front clamp member 83. The clamp members 83 and 81 are moved toward and away from each other by the rotary threaded stud 84 controlled by the rotary clamp handle 85. By releasing the clamp mechanism in the stop member 80, the stop flange 82 may be located in any vertical position along the clamp plates 77 and 78, such as the solid-line position disclosed in FIGS. 6 and 7.
The left guide plate 77 may include the graduations G, which are calibrated to correspond with different desired band lengths. Thus, when a particular band length is desired, the stop member 80 is moved to register with one of the graduation marks G, and a band 21 having the indicated length will be produced by the apparatus 20.
As the hydraulic cylinder 72 causes the measure rod 66 to descend, the block 64 will continue to travel until it engages the stop flange 82, such as illustrated in phantom in FIG. 7, to stop the measure rod 66 at its lowermost position to form the open loop 62 of the desired depth. The stop flange 82 engaging the block 64 will override any further movement of the cable 68 even though the hydraulic cylinder 72 is still actuated.
With reference to FIGS. 6, 12, 13 and 14, a loop loading mechanism 86 is located slightly below the measuring path P of the fabric strip 22, and astride the open loop 62 for clamping and loading the upper ends of the open loop 62 upon the sewing machine head 25. The loop loading mechanism 86 includes a cylinder mounting bar 87 fixed to a portion of the frame 23. The cylinder mounting bar 87 supports a pair of stop cylinders 88 and a pair of clamp cylinders 90. These pairs of cylinders are disposed symmetrically about the axis of the vertical path of reciprocation of the measure rod 66. The piston rods 91 actuated by the fluid clamp cylinders 90 are fixed to a transverse clamp carriage 97 to which are fixed the upward projecting clamp fingers 92.
The push-up or lift cylinders 89 are slidably mounted in the cylinder mounting bar 87 and are fixed to the clamp carriage 97. Thus, when the clamp carriage 97 moves upward with the clamp fingers 92, the push-up cylinders 89 along with the push-up fingers 93 actuated by the push-up cylinders 89 are likewise carried with the carriage 97.
The stop piston 94 actuated by each stop cylinder 88 extends slidably through the carriage 97 and terminates in an enlarged stop head 95.
A clamp plate 96 is fixed to the bottom of the sewing machine head 25 to cooperate with the clamp fingers 92 in clamping the opposite end portions of the open loop 62 between the fingers 92 and the clamp plate 96.
The clamp carriage 97 is adapted to occupy a lower retracted position, as disclosed in the right-hand portion of FIG. 12 and also in FIG. 6, whereby all parts of the loading mechanism 86 will be out of the way of the reciprocal path of the pull-clamp mechanism 50. An intermediate measuring position of the clamp carriage 97 is disclosed in the left-hand portion of the carriage 97 in solid lines in FIG. 12, in which the clamp fingers 92 have their upper-clamp faces or tips substantially in the plane of the measuring path P to function as guides over which the upper end portions of the open loop 62 are held and guided during the measuring cycle. This measuring position is determined by the stop heads 95 which are locked in their solid-line positions disclosed in FIG. 12 by the stop cylinders 88.
When the pressure in the stop cylinders 88 is released to permit the stop heads 95 to float, the clamp cylinders 90 can then thrust the carriage to an upper clamping position in which the clamp fingers 92 clamp against the clamp plate 96, thereby clamping the upper end portions of the open loop 62 against the fixed clamp plate 96.
After the clamped end portions are cut by the knife blades 44 and 43, the cut free end portions of the open loop 62 project outward beyond the clamp fingers 92 and in the path of the push-up fingers 93. By actuation of the push-up cylinders 89, the push-up fingers 93 will protract upward to deflect the free end portions of the open loop 62 up along the sides of the sewing machine head 25, preparatory to having the free end portions deflected over the work plate 27 and into the stitching station 26.
The ejection mechanism 98 is best disclosed in FIGS. 15-19. The ejection mechanism 98 is mounted on a support bar 99 in front of the sewing machine head 25 for longitudinal movement toward and away from the sewing machine head 25. The ejection mechanism 98 includes a carriage frame 100 reciprocably movable front-to-rear by piston rod 101 actuated by the hydraulic cylinder 102.
The carriage frame 100 include a pair of rearward projecting arm members 103 and 104 supporting vertically disposed clamp cylinders 105 operating vertically reciprocable upper clamp shoes 106. The upper clamp shoes 106 are adapted to cooperate with the lower fixed clamp shoes 107.
Each arm 103 and 104 is also provided with a rotary shaft or stem 109 to which is fixed a wiper finger 110 which is free to swing in a horizontally rotary path. Each wiper finger 110 is controlled by a hydraulic wiper cylinder 111 to swing across the upstanding free ends of the open fabric loop 62 held against the sewing machine head 25 by the push fingers 93. The inward swinging wiper fingers 110 depress the loop ends and cause them to overlap each other in loading station 112 (FIG. 19) adjacent the sewing station 26. The clamp cylinders 105 are actuated to depress the upper clamp shoes 106 downward upon the fabric ends and hold them against the lower clamp shoes 107.
After the free end portions of the fabric loop 62 are clamped in the loading station 112 as disclosed in FIG. 19, the ejector mechanism 98 is retracted to move the overlapping clamped fabric ends from the loading station 112 to the sewing station 26, as disclosed in FIGS. 15 and 19. This movement is accomplished by releasing the pressure on the stop cylinder 113, which normally supports a stop head 114 in the phantom load position disclosed in FIG. 15. When the pressure is relieved from the stop cylinder 113, pressure within the cylinder 102 causes the rod 118 to overcome the stop head 114 to move the overlapping fabric ends into the sewing station 26.
As illustrated in FIG. 19, when the overlapping fabric ends are moved into the sewing station 26, they abut against a fixed edge flange 115 to align the fabric edges before the stitching operation.
The ejector mechanism 98 remains in the retract position clamping the open ends in overlapping relationship as long as the stitching operation continues. After the needle 28 has completed its stitching of the overlapping ends of the open fabric loop 62, the controls, not shown, are automatically actuated to cause the ejection carriage 100 to protract forwardly, carrying with it the completed band 21. The clamp shoes 106 and 107 remain closed about the legs of the stitched completed fabric band 11. As the carriage 100 continues protracting to remove the band from the sewing machine head 25, a depending stationary fork member 116 engages the band while the upper clamp shoes 106 are retracted upward to release the band 11 from the ejection mechanism 98. The removed loop falls to a discharge site, not shown, such as a receptacle for the completed bands or a discharge conveyor, not shown.
Also mounted on the frame 23 in front of the sewing machine head 25, is a loop extraction mechanism 120 (FIGS. 2 and 8-11). The frunction of the loop extraction mechanism 120 is to remove the open loop 62 out of the fabric measuring path P as soon as the free ends of the open loop 62 have been clamped by the clamp fingers 92 against the clamp plate 96, to permit the initiation of the next measuring cycle without having to wait until the previous band is completely sewn and removed. The loop extraction mechanism 120 includes a pair of vertical standards 121 fixed upon a slide block 122 having bearings permitting it to travel along the slide rods 123 fixed to the horizontal machine frame member 76. The slide block 122 is connected to a piston rod 124 actuated by the hydraulic or fluid cylinder 125 also fixed to the frame member 76. As disclosed in FIGS. 8 and 9 the front ends of the guide rods 123 may be supported by a bracket 126 and an adjustable foot member 127.
Supported in the vertical standards 126 are corresponding vertically adjustable extension arms 128 which terminate in rearwardly projecting hook members 129. The hook members 129 oppose each other, having lateral bight portions 130 terminating in forwardly directed, converging free end portions 131. The converging free end portions 131 are so shaped that as the hook members 129 move rearwardly, the free end portions will engage and cam the depending legs of the suspended open loop 62 toward each other. After the legs of the loop 62 have cleared the free end portions 131 they will spring back to their original attitude, but now in alignment with, and in front of, bight portions 130 of the hook members for engagement therewith upon the forward travel of the hook members 129.
In the initial position of the extraction mechanism 120, the slide block 122 and hook members 129 are retracted rearwardly until the hook members 129 are behind the depending band legs far enough that the band legs will be captured by the hook members 129. Thus, upon the forward movement of the extraction mechanism 120, the lateral bight portions 130 will engage the legs of the open band loop 62 to carry them forward, out of the way of the longitudinal measuring path of the fabric strip 22. Thus, the open loop 62 is completely out of the way of the reciprocable path of the pull-clamp mechanism 50, so that the clamp member 51 may be projected to the area of the cutting station 42 for gripping the cut end of the continuous fabric strip 22.
Because of the extraction mechanism 120, the next measuring cycle can be initiated before the previous cycle of stitching the ends of the loop 62 and ejecting the fabric band 21, is completed, thereby reducing the operational time and improving the production of the apparatus 10.
It has been found that the apparatus 10 may operate to produce continuously as many as 14 bands per minute, as opposed to prior known machines which make approximately 10 bands per minute.
The purpose of the oscillating feed mechanism 33 is to oscillate or vibrate the initial portion of the fabric strip 22 being fed to the apparatus 10 from the supply roll 32 in order to straighten out the fabric strip 22 and to eliminate any folds, wrinkles or twisted portions.
As best disclosed in FIGS. 20-21 the oscillating feed mechanism 53 includes a rotary electric motor 133 fixed upon a bracket 134 connected to a portion of the frame arm 29 and adapted to drive a crank arm 135. The extremity of the crank arm 135 is connected to a cam roller 136 extending through an elongated slot 137 of an oscillating arm 138. The upper end of the oscillating arm 138 is connected to the mounting plate 134 by a pivot pin 139, while its lower end supports a guide loop 140 for receiving the fabric strip 22. Actuation of the motor 133 causes the oscillating arm 138 to oscillate rapidly about its pivot pin 139 and causes the guide loop 140 to rapidly shake or vibrate the fabric strip 22 to remove any folds or wrinkles from the strip in order to straighten the fabric strip 22 as it is fed to the guide track 24.
The operation of the apparatus 10 readily becomes apparent from the previous description of the structure and function of the various elements.
The elongated fabric strip 22 is fed from the roll 32 through the oscillating feed mechanism 33, where the folds and wrinkles are removed from the fabric strip 22 in order to straighten it. The fabric strip is then drawn over the guide rods 34 and 35 by the feed rollers 30 to the guide track 24, where the free end portion of the strip 22 is held against the track 24 by the weighted pivotal pawl 40.
A slack loop 41 is maintained in the fabric strip 22 between the drive feed rollers 30 and the guide track 24 by the pivotal tension arm 37 controlling the switch 38, which in turn controls the operation of the motor 31.
The controls for the sequential steps of the various mechanisms are of a conventional type, and they may include timer motors, timer switches and/or limit switches at appropriate locations.
After the fabric strip 22 is positioned with its free end at the cutting station 42, the pull-clamp mechanism 50 is actuated to cause the clamp frame 51 to project longitudinally beneath the sewing machine head 25 and toward the cutting station 42. When the clamp frame 51 is in the cutting station 42, the lower clamp 53 is actuated to grip the free end portion of the fabric strip 22 between the clamp jaws 52 and 53. Then, the pull-clamp mechanism 50 is retracted to draw the fabric strip along the measuring path P beneath the sewing machine head 25 and beneath the measure rod 66 in its upper inoperative position. When the pull-clamp mechanism 50 has reached its fully retracted position as disclosed in FIGS. 1 and 3, the free end of the fabric remains clamped by the clamp frame 51, preparatory to the measuring cycle.
The hydraulic cylinder 72 of the measuring mechanism 61 is then actuated to cause the measure rod 66 to move downward engaging and deflecting that portion of the fabric strip 22 in the measuring path, until the guide block 64 engages the stop flange 82.
At this point, the open loop 62 has been established to its desired depth.
About this time, the controls are sequenced to actuate the extraction mechanism 120 to move behind, capture and then move forward and engage the opposite legs of the open loop 62 to transfer the loop 62 out of the measuring path P of the fabric strip 22 to permit continued cycling of the apparatus 10.
The actuation of the cylinder 72 is then reversed to cause the measure rod 66 to return to its upper inoperative position. The upper end portions of the open loop 62 are clamped by the respective clamp fingers 92 against the fixed clamp plate 91, at which time the cutting mechanism is actuated to cut the fabric strip 22 and separate the open loop 62 from the rest of the strip 22.
The ejection mechanism 98 is actuated to cause the carriage 100 to retract toward the sewing machine head 25, causing the wiper fingers 110 to wipe the upper free ends of the fabric loop 62 across each other upon the sewing machine work plate 27 in the loading station 112. The upper clamp shoes 106 are depressed to grip the opposite end portions of the overlapping open loop 62. The carriage 100 is then retracted further to place the overlapping ends in the stitching station 26 while the sewing machine head 25 operates to stitch the ends of the open loop 62 together to form the completed band 21. The clamp shoes 106 and 107 remain closed while the carriage 100 protracts to remove the completed band from the sewing machine until the band is engaged by the depending fork member 116, the clamp shoes are opened and the band is discharged from the apparatus 20.
In order to make bands of a different length, the clamp member 80 is adjusted along the vertical track defined by the guide plates 77 and 78 to the desired position opposite the graduation marks G and the stop flange 82 is re-clamped in the new position. Such an adjustment operation requires a minimum of time in order to change over to the fabrication of the new fabric band of different length. | An apparatus for securing the free ends of an elongated strip of flexible material to form a band, such as an elastic band for various types of apparel. The machine includes a securing station, such as a sewing station including a sewing machine, and an apparatus for drawing a strip of flexible material longitudinally beneath the securing station in a measuring path. A measuring device deflects a predetermined length of the strip downward away from the measuring path to form a measured open loop. A knife mechanism cuts the trailing end portion of the loop. Loading and clamping mechanisms position the free ends of the loop in the securing station for attachment, such as by stitching. An ejection mechanism withdraws the finished loop from the sewing station for discharge. The measuring device is provided with adjustment means for adjusting the length of the deflected loop and therefore the size of the completed band. The apparatus preferably includes an extraction mechanism for withdrawing the clamped, measured loop from the measuring path while the loop is being secured to permit initiation of the next measuring cycle. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates in general to automated patient management and, specifically, to a system and method for providing hierarchical medical device control for automated patient management.
BACKGROUND OF THE INVENTION
[0002] In general, implantable medical devices (IMDs) can provide in situ therapy or monitoring under preprogrammed autonomous control. Autonomous control is governed by tunable and fixed control parameters, which are physician-selected to meet therapy goals. IMDs must be periodically interfaced to external devices, such as programmers and patient management devices, for physician follow-up. Physicians assess a patient's current condition based on downloaded patient data and lab or clinical tests, such as electrophysiology tests, treadmill stress tests, and blood work, to determine if treatment goals are being met or whether control parameters require reprogramming.
[0003] IMD therapy is intended to meet specific goals and therapy is selected based upon physician experience and population data for comparable patient outcomes. A therapy goal is implemented by specifying actions to be performed by the IMD under a treatment plan through downloadable control parameters. The medical means for implementing a treatment plan will depend upon the patient profile and medical resources available.
[0004] Progress towards a therapy goal can be gauged in light of the scope of control over and the therapeutic affect made upon a patient. For example, an IMD exercises direct control over a patient. IMD resources are constrained in terms of processing, storage, and power budget. As a result, IMDs can only provide a temporally limited perspective of the efficacy of the therapy provided due to the restricted memory available.
[0005] Implementing goal-directed operation on IMDs can be a challenge. Therapy is directed to patient management at a micro level and IMDs lack the resources to maintain and track progress towards a goal defined more broadly than an event occurrence. Goal-directed patient management is better handled at a macro level as provided on an external device, such as a server or patient management device. External devices allow patient data to be downloaded and tracked over time to build a more comprehensive picture of the patient's progress and therapy can be adjusted as necessary. Conventional approaches to goal-directed patient management, however, adopt open loop control strategies that require the involvement of a clinician, such as a physician, nurse, or other qualified individual.
[0006] U.S. Pat. No. 6,416,471, issued to Kumar et al. (“Kumar”) discloses a remote patient telemonitoring device. A disposable sensor band with electrode patches detects and transmits vital signs data to a signal transfer unit, which can either be worn or be positioned nearby the patient. The base station receives data transmissions from the signal transfer unit for transferring the collected data to a remote monitoring station. Indications are provided to a patient from the base station when threshold violations occur, but the system requires an operator, such as a physician or nurse, to manually review and provide an interpretation of the patient data.
[0007] U.S. Pat. No. 6,024,699, issued to Surwit et al. (“Surwit”) discloses a central data processing system configured to communicate with and receive data from a plurality of patient monitoring systems, which may implement a medical dosage algorithm to generate dosage recommendations. Blood from a pricked finger may be read on a chemically treated strip. Modifications to medicine dosages, medicine dosage algorithms, patient fixed or contingent self-monitoring schedules, as well as other treatment information are communicated, but screen mechanisms are provided to case managers for ensuring that treatment or information provided is medically sound before communicating that treatment or information to the patient or patient management device.
[0008] U.S. Pat. No. 6, 083,248, issued to Thompson discloses a worldwide patient location and data telemetry system for implantable medical devices. An implanted device telemetry transceiver within the implanted medical device communicates data and operating instructions to and from a medical device in a coded communication. A global positioning system provides data identifying the position of the patient. Should a need to upgrade or change the behavior of implanted devices arise, the system allows the central monitoring site to revise interfaced IMDs by transmitting new programming instructions, assuming appropriate governmental authorities and patients′physicians have agreed to the need for such changes.
[0009] Therefore, there is a need for providing remote patient management with closed loop reporting and control in a hierarchical structure that allows goal and sub-goal delegation and therapy feedback through levels of distributed control.
SUMMARY OF THE INVENTION
[0010] A system and method includes a closed loop control hierarchy having two or more levels. The top, or root level, contains a server that centrally manages a control strategy. The penultimate level includes medical devices, such as implantable or external medical devices or sensors, and the bottom, or terminal, level includes their respective sensors and effectors. In one embodiment, the control hierarchy includes an intermediate logical level that includes one or more patient management devices, each dedicated to servicing one or more of the medical devices. Both the server and each patient management device function as controllers over physical plants that can include those devices assigned to children nodes in the control hierarchy. Control is exercised over and feedback is received from the assigned devices. Control is exercised by delegating sub-goals to the assigned devices. Feedback is analyzed against locally-maintained state to identify whether changes to the existing control strategy are necessary.
[0011] One embodiment provides a system and method for providing hierarchical medical device control for automated patient management. A processor is operatively coupled to a plurality of medical devices on a substantially continual basis to receive sensor data. A control strategy is assigned to the processor to specify actions to be taken by the medical devices to affect the attainment of a therapy goal. State is maintained, selected from the group comprising a history of changes to the control strategy and past sensor data received from the medical devices. Feedback is periodically received. The feedback includes new sensor data from the medical devices. The feedback and the state are analyzed against the actions specified in the control strategy. Control is provided to one or more medical device in response to an actionable change from the actions specified in the control strategy.
[0012] Still other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein are described embodiments of the invention by way of illustrating the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the spirit and the scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a functional block diagram showing, by way of example, an automated patient management environment.
[0014] FIG. 2 is a tree diagram showing, by way of example, a control hierarchy of medical devices for use in the patient management environment of FIG. 1 .
[0015] FIG. 3 is a data flow diagram showing hierarchical medical device control and feedback in the patient management environment of FIG. 1 .
[0016] FIGS. 4 A-C are Venn diagrams showing, by way of example, data sets as maintained in the patient management environment of FIG. 1 .
[0017] FIG. 5 is a graph showing the relationship between sampling frequency and sample size.
[0018] FIG. 6 is a flow diagram showing a method for providing hierarchical medical device control for automated patient management for use on the server of FIG. 3 .
[0019] FIG. 7 is a flow diagram showing a method for providing hierarchical medical device control for automated patient management for use on a patient management device of FIG. 3 .
[0020] FIG. 8 is a flow diagram showing a method for providing hierarchical medical device control for automated patient management for use on a medical device of FIG. 3 .
[0021] FIG. 9 is a block diagram showing a system for providing hierarchical medical device control for automated patient management for use on the server of FIG. 3 .
[0022] FIG. 10 is a block diagram showing a system for providing hierarchical medical device control for automated patient management for use on a patient management device of FIG. 3 .
[0023] FIG. 11 is a block diagram showing a system for providing hierarchical medical device control for automated patient management for use on a medical device of FIG. 3 .
DETAILED DESCRIPTION
[0000] Automated Patient Management Environment
[0024] Automated patient management encompasses a range of activities, including remote patient management and automatic diagnosis of patient health, such as described in commonly-assigned U.S. Pat. application Pub. No. US2004/0103001, published May 27, 2004, pending, the disclosure of which is incorporated by reference. Such activities can be performed proximal to a patient, such as in the patient's home or office, centrally through a centralized server, such from a hospital, clinic or physician's office, or through a remote workstation, such as a secure wireless mobile computing device. FIG. 1 is a functional block diagram showing, by way of example, an automated patient management environment 10 . In one embodiment, a patient 14 is proximal to one or more patient monitoring or communications devices, which are interconnected remotely to a centralized server 13 over an internetwork 11 , such as the Internet, or through a public telephone exchange (not shown), such as a conventional or mobile telephone network. The patient monitoring or communications devices non-exclusively include a patient management device 12 , such as a repeater, personal computer 19 , including a secure wireless mobile computing device, telephone 20 , including a conventional or mobile telephone, and facsimile machine 21 . In a further embodiment, a programmer 22 , such as a programmer or programmer-recorder monitor, can be used by clinicians, such as physicians, nurses, or qualified medical specialists, to interrogate and program medical devices. Finally, the centralized server 13 is remotely interfaced to a patient care facility 25 , such as a clinic or hospital, to ensure access to medical response or patient care providers. Other patient monitoring or communications devices are possible. In addition, the internetwork 11 can provide both conventional wired and wireless interconnectivity. In one embodiment, the internetwork 11 is based on the Transmission Control Protocol/Internet Protocol (TCP/IP) network communication specification, although other types or combination of networking implementations are possible. Similarly, other network topologies and arrangements are possible.
[0025] Each patient management device 12 is uniquely assigned to a patient under treatment 14 to provide a localized and network-accessible interface to one or more medical devices, which serve as patient data sources 15 - 18 , either through direct means, such as wired connectivity, or through indirect means, such as inductive coupled telemetry, optical telemetry, or selective radio frequency or wireless telemetry based on, for example, “strong” Bluetooth or IEEE 802.11 wireless fidelity “WiFi” and “WiMax” interfacing standards. Other configurations and combinations of patient data source interfacing are possible.
[0026] Patient data includes physiological measures, which can be quantitative or qualitative, parametric data regarding the status and operational characteristics of the patient data source itself, and environmental parameters, such as the temperature, barometric pressures, or time of day. The patient data sources collect and forward the patient data either as a primary or supplemental function. Patient data sources 15 - 18 include, by way of example, medical devices that deliver or provide therapy to the patient 14 , sensors that sense physiological data in relation to the patient 14 , and measurement devices that measure environmental parameters occurring independent of the patient 14 . Other types of patient data are possible, such as third party data 26 received from external data sources, including repositories of empirical studies, public and private medical databases, patient registries, and the like. Additionally, current clinician-established guidelines associated with treatment can help to guide acceptable best practice treatment for patient care. Each patient data source can generate one or more types of patient data and can incorporate one or more components for delivering therapy, sensing physiological data, measuring environmental parameters, or a combination of functionality.
[0027] In a further embodiment, data values can be entered by a patient 14 directly into a patient data source. For example, answers to health questions could be input into a measurement device that includes interactive user interfacing means, such as a keyboard and display or microphone and speaker. Such patient-provided data values could also be collected as patient information. Additionally, measurement devices are frequently incorporated into medical therapy devices and medical sensors. Medical therapy devices include implantable medical devices (IMDs) 15 , such as pacemakers, implantable cardiac defibrillators (ICDs), drug pumps, and neuro-stimulators, and external medical devices (EMDs) 16 , such as automatic external defibrillators (AEDs). Medical sensors include implantable sensors 17 , such as implantable heart and respiratory monitors and implantable diagnostic multi-sensor non-therapeutic devices, and external sensors 18 , such as 24-hour Holter arrhythmia monitors, ECG monitors, weight scales, glucose monitors, oxygen monitors, and blood pressure monitors. Other types of medical therapy, medical sensing, and measuring devices, both implantable and external, are possible.
[0028] The patient management device 12 collects and temporarily stores patient data from the patient data sources 15 - 18 for periodic upload over the internetwork 11 to the server 13 and storage in a patient population database 24 . Each patient 14 can be remotely managed through hierarchical control exercised by the server 13 over the patient management devices 12 and patient data sources 15 - 18 , as further described below beginning with reference to FIG. 2 . Briefly, a clinician defines a therapy goal for a patient based on a stored physiological assessment of a diagnosed disease state. The server 13 defines a control strategy for meeting a therapy goal and the control strategy is delegated to each of the devices through goals and sub-goals to form a closed loop control system. Control flows downward through the hierarchy, increasing in specificity with each decreasing level, and feedback flows upward, increasing in detail and temporal scope with each increasing level.
[0029] Each patient data source 15 - 18 collects the quantitative physiological measures on a substantially continuous basis and also records the occurrence of events, such as therapy or irregular readings. In a still further embodiment, the patient management device 12 , personal computer 19 , telephone 20 , or facsimile machine 21 record or communicate qualitative quality of life (QOL) measures that reflect the subjective impression of physical well-being perceived by the patient 14 at a particular time. Other types of patient data collection, periodicity and storage are possible.
[0030] In a further embodiment, the collected patient data can also be accessed and analyzed by one or more clients 23 , either locally-configured or remotely-interconnected over the intemetwork 11 . The clients 23 can be used, for example, by clinicians to securely access stored patient data assembled in the database 24 and to select and prioritize patients for health care provisioning, such as respectively described in commonly-assigned U.S. patent application, Ser. No. 11/121,593, filed May 3, 2005, pending, and U.S. patent application, Ser. No. 11/121,594, filed May 3, 2005, pending, the disclosures of which are incorporated by reference. Although described herein with reference to physicians or clinicians, the entire discussion applies equally to organizations, including hospitals, clinics, and laboratories, and other individuals or interests, such as researchers, scientists, universities, and governmental agencies, seeking access to the patient data.
[0031] In a further embodiment, patient data is safeguarded against unauthorized disclosure to third parties, including during collection, assembly, evaluation, transmission, and storage, to protect patient privacy and comply with recently enacted medical information privacy laws, such as the Health Insurance Portability and Accountability Act (HIPAA) and the European Privacy Directive. At a minimum, patient health information that identifies a particular individual with health-and medical-related information is treated as protectable, although other types of sensitive information in addition to or in lieu of specific patient health information could also be protectable. Additionally, for purposes of utilizing information in the population database 24 or third party data 26 , comparison data can be de-identified, such that specific patient identification is not available.
[0032] Preferably, the server 13 is a server-grade computing platform configured as a uni-, multi-or distributed processing system, and the clients 23 are general-purpose computing workstations, such as a personal desktop or notebook computer. In addition, the patient management device 12 , server 13 and clients 23 are programmable computing devices that respectively execute software programs and include components conventionally found in computing device, such as, for example, a central processing unit (CPU), memory, network interface, persistent storage, and various components for interconnecting these components.
[0000] Medical Device Hierarchy
[0033] A control strategy is a closed-loop combination of all actions taken by the various medical devices that affect the attainment of a therapy goal. A control strategy can involve a server 13 , one or more patient management devices 12 , and one or more medical devices 15 - 18 . By default, the specificity of control, as delegated through the control strategy, is exercised over the operations performed by the server 13 , patient management devices 12 , and medical devices 15 - 18 to increase with immediacy to the patient 14 . Conversely, the scope of feedback provided by these devices increases with distance from the patient 14 . These characteristics can be formed into a hierarchy of bi-directional control and feedback. FIG. 2 is a tree diagram showing, by way of example, a control hierarchy 30 of medical devices for use in the patient management environment 10 of FIG. 1 . The control hierarchy 30 is structured into four levels respectively corresponding to a server; one or more patient management devices; one or more medical devices that are each assigned to a patient management device; and sensors and effectors that respectively measure physiological data and deliver therapy.
[0034] A server is at the top or root level 31 of the control hierarchy 30 and serves as the primary controller for the patient management environment 10 . From the prospective of the server, the successive levels 32 - 34 of the control hierarchy 30 constitute the physical plant over which control is exercised and from which feedback is received.
[0035] The patient management devices form an intermediate level 32 of the control hierarchy 30 and interface to both the server and one or more medical devices. In one embodiment, each patient management device is uniquely identified to a single patient 14 . In a further environment, a patient management device can be shared by a plurality of patients 14 . Each patient management device operates as a controller over the medical devices assigned, which constitute the physical plant over which the patient management device exercises control and from which feedback is received. In addition, each patient management device sends feedback to the server and receives control in the form of sub-goals from the server.
[0036] The medical devices form a penultimate level 33 of the control hierarchy 30 and can include sensors, effectors, or both, which are on the bottom or terminal level 34 of the control hierarchy 30 . Each medical device functions as a controller over the sensors and effectors, which, in combination with the patient 14 , constitute the physical plant over which control is exercised via the effectors and from which feedback is received from the sensors. In addition, each medical device sends feedback to the patient management device and receives control in the form of sub-goals from the patient management device.
[0037] In a strict control hierarchy 30 , control is only exercised over and feedback is only received from the devices assigned to the next immediate level of the control hierarchy 30 . In a more relaxed and pragmatic control hierarchy 30 , control can flow down to and feedback can be received from the devices in any successive level of the control hierarchy 30 , with one exception. Each medical device is physically coupled to sensors and effectors and operates under an event response control strategy, which does not admit to cooperative external control. However, a server can still exercise control over and receive feedback directly from patient medical devices and medical devices.
[0038] When executing as a closed loop control system, outside control and feedback reporting are not provided. However, direct control over the server, patient medical devices, and medical devices is possible and, for bootstrapping the server, necessary to specify initial therapy goals and implementing actions, including control parameters, environmental settings, and hierarchy assignments, such as further described below with reference to FIG. 3 . Other levels or configurations and arrangements of tiered hierarchical control in addition to or lieu of a tree structure are also possible.
[0000] Data Flow
[0039] Generally, control flows downward in increasing levels of specificity and feedback flows upward in increasing levels of detail and temporal scope. FIG. 3 is a data flow diagram showing hierarchical medical device control and feedback 40 in the patient management environment 10 of FIG. 1 . The server 41 is operatively coupled to a one or more patient management devices 42 , which are each in turn operatively coupled to one or more medical devices 43 . Each medical device 43 includes one or more sensors 44 , one or more effectors 45 , or a combination of both sensors 44 and effectors 45 depending upon the type of medical device.
[0040] The server 41 exercises patient-level control 56 over the patient management device 42 assigned and, in a further embodiment, device-level control 52 over medical devices 43 . Each patient management device 42 exercises device-level control 52 over the medical devices 43 assigned. As event/response control devices, each medical device 43 maintains exclusive control over the interfaced sensors 44 and effectors 45 . Each medical device 43 delivers therapy 48 , such as pacing stimuli, through the interfaced effectors 45 and receives physiological measures 46 from the interfaced sensors 44 . The received physiological measures 46 are transiently staged by the medical device 43 as limited state 47 before being uploaded to the assigned patient management device 42 and, in a further embodiment, the server 41 , as device-level feedback 50 that can be analyzed with local state 51 , 55 against the current control strategy. Each patient management device 42 uploads patient-level feedback 54 to the server 41 , which can include physiological measures, parametric data, and environmental parameters as well as the results of local analyses and unprocessed device-level feedback 50 . In addition to analyzing patient-level feedback 54 and, in a further embodiment, device-level feedback 50 , the server 41 maintains access to the patient population database 24 and, in a further embodiment, third party data 26 , which can both be factored into the analyses performed by the server 41 . Other types of feedback and data access, exchange, and storage are possible.
[0041] A control strategy is implemented through goals and sub-goals that are delegated to devices in order of increasing specificity relative to the level of control exercised over the patient 14 . Patient-level control 56 , for instance, delegates a control strategy specific to a particular patient 14 who is uniquely assigned to a patient management device 42 . Patient-level control 56 can affect one or more individual medical devices 43 . Similarly, device-level control 52 delegates a control strategy specific to a particular medical device 43 based on the medical device type and the indicated form of therapy.
[0042] Direct control 49 , 53 , 57 can respectively be exercised over each medical device 43 , patient management device 42 , and the server 41 , as would be necessary, for example, to set up the initial control parameters and environment settings necessary for each device to join into a hierarchical control strategy. Direct control over a medical device 43 can be provided through a programmer 22 (shown in FIG. 1 ) or patient management device 42 . Direct control over a patient management device 42 could be provided through a client 23 (also shown in FIG. 1 ) or via a user interface of the patient management device 42 . Direct control over the server 41 could be provided through a client 23 .
[0043] Conversely, the detail and temporal scope of feedback increases as the available resources for storing and processing feedback increase and as the number of individual sources of feedback grow. Medical devices 43 , as event/response control systems, maintain only limited state 47 in which to store temporarily physiological measures 47 received from interfaced sensors 44 . With limited processing and power budget resources, each medical device 47 is typically constrained to limit processing of the physiological measures 46 to the extent necessary to determine the applicability to therapy delivery to the patient 14 . Patient management devices 42 enjoy significantly more capable resources, including processing and storage, in which to store and analyze device-level feedback 50 , which can be evaluated against the control strategy and analyzed, for instance, for trends indicating a progression, regression, absence, onset, or status quo of a physiological condition, and changes to the control strategy exercised by the assigned medical devices 43 can be effected through device control 52 , which can include control parameters to reprogram assigned medical devices 43 . The server 41 enjoys processing and storage resources at least on par with the patient management devices 42 and, typically, has far more capable resources. However, the wider range of sources of feedback, including patient-level feedback 54 from a plurality of patient management devices 42 and, in a further embodiment, directly-received device-level feedback 50 from a plurality of medical devices 43 , introduce a richness of patient data at a population level that enables the server 41 to perform a wider range of comparative analyses across a spectrum of patient characteristics and health conditions, such as described in commonly-assigned U.S. patent application, entitled “System And Method For Providing Goal-Oriented Patient Management Based Upon Comparative Population Data Analysis,” Ser. No.______, filed on Jan. 19, 2006, pending, the disclosure of which is incorporated by reference. Other forms of analyses and processing are possible.
[0000] Data Set Examples
[0044] Each device maintains data sets that include feedback and control strategy data. FIGS. 4 A-C are Venn diagrams showing, by way of example, data sets 70 as maintained in the patient management environment 10 of FIG. 1 . The composition of each data set reflects the capabilities and storage capacities of the device. For instance, the data sets maintained by each medical device 43 are the most constrained due to the limited processing and storage resources available, whereas the data sets maintained by each patient management device 42 and by the server 41 are less constrained in terms of both processing and storage resources. Referring first to FIG. 4A , the data sets 70 maintained by medical devices 43 can include physiological measures or locally-generated data and analyses (“measures”) 71 , control parameters 72 , or a combination of measures and control parameters 73 , depending upon the type of medical device.
[0045] Patient management devices 42 have greater processing capabilities and storage capacities than medical devices 43 . Referring next to FIG. 4B , the data sets 74 maintained by patient management devices 42 can include measures recorded or generated by assigned medical devices 75 , control parameters of assigned medical devices 76 , or a combination of measures and control parameters 77 . The measures 75 are provided as device-level feedback 50 . In addition, the data sets 74 can also include physiological measures or data and analyses 78 that have respectively been locally measured or generated by the patient management devices 42 .
[0046] Finally, the server 41 has a patient population-wide prospective, which potentially encompasses all of the individual data sets for assigned patient management device 42 and medical devices 43 . Referring to FIG. 4C , the data set 79 maintained by the server 41 can include all of the medical device data sets and patient management device data sets. In addition, the data set 79 can also include data and analyses (not shown) that have been locally generated by the server 41 . Other forms, combinations, and compositions of data sets are possible.
[0000] Sampling
[0047] The detail and temporal scope of feedback grows as the number of independent sources and the rates of sampling applied at each hierarchy level increase. FIG. 5 is a graph 80 showing the relationship between sampling frequency and sample size. The x-axis represents the sampling frequency 81 and the y-axis represents the sample size 82 .
[0048] In a control system with unlimited sampling resources, including state, an unconstrained sample size will continue to increase as a function 83 of the sampling frequency. However, due to the inherent limits in sampling resources in discrete devices, particularly with respect to medical devices 43 and the limited state 47 available for storing samples, the sample size instead decreases as a function 84 of the sampling frequency with the smallest samples being collected with the highest frequency by the medical devices 43 and largest samples being collected by the server 41 and patient management devices 42 with the lowest frequencies. Thus, medical devices 43 generally employ sampling rates in the millisecond range, while dedicated patient management devices 42 can sample on an hourly or daily basis and the server 41 can sample on a daily, weekly or monthly basis. The differences in sampling frequency allow each respective device to accumulate additional patient data samples and, where resources permit, to perform comparative analyses on the patient data to summarize and identify trends. Other sampling frequency and samples size relationships between the medical devices are possible.
[0000] Server Method
[0049] The operations performed by the server 41 , patient management devices 42 , and medical devices 43 are dependent upon the applicable sources and destinations of feedback and control strategy. Except when provided direct control 57 from external sources, such as a clinician providing instructions through a client 23 , the server 41 functions as an autonomous closed loop controller that exercises control over the patient management devices 42 and medical devices 43 assigned to the control hierarchy. FIG. 6 is a flow diagram showing a method 90 for providing hierarchical medical device control for automated patient management for use on the server 41 of FIG. 3 . The method 90 is generally performed on the server 41 , but could also be performed on a patient management device 42 or client 23 with sufficient resources and interconnections.
[0050] Initially, a control strategy is defined (block 91 ), which can be provided through direct control 57 or by analysis of the patient population database 24 or other sources, such as described in commonly-assigned U.S. patent application, entitled “System And Method For Providing Goal-Oriented Patient Management Based Upon Comparative Population Data Analysis,” Ser. No.______, filed on Jan. 19, 2006, pending, the disclosure of which is incorporated by reference. The control strategy can be decomposed into sub-goals that can be delegated to patient management devices 42 as patient-level control 56 and, in a further embodiment, as device-level control 52 to medical devices 43 (block 92 ). A closed control loop is then initialized (block 93 ) by verifying, as necessary, connectivity to each assigned patient management device 42 and medical device 43 and confirming satisfactory operational statuses. The continuous closed control loop (blocks 94 - 99 ) is then performed until the processing infrastructure, for instance, the server 41 , terminates execution.
[0051] During each cycle (block 94 ), patient-level feedback 54 is received and integrated into the state 55 maintained by the server 41 (block 95 ). The patient-level feedback 54 and state 55 are analyzed against the current control strategy, such as through data mining (block 96 ). In one embodiment, the state is represented as a matrix dimensioned temporally as a set of vectors for the tracked patient data, including physiological measures, control parameters, and environmental parameters. Other types of tracked patient data and forms of internal state representation are also possible. If based on the analysis, the control strategy requires adjustment (block 97 ), revised patient-level control 56 and, in a further embodiment, device-level control 52 , are sent to the appropriate device (block 98 ). Closed control loop processing (block 99 ) is performed continually, but can be subject to interruption or modification by external sources, such as direct control 57 .
[0000] Patient Management Device Method
[0052] Except when provided direct control 53 , each patient management device 42 also functions as an autonomous closed loop controller that exercises control over the medical devices 43 assigned to the control hierarchy, subject to patient-level control 56 delegated by the server 41 . FIG. 7 is a flow diagram showing a method 110 for providing hierarchical medical device control for automated patient management for use on a patient management device 42 of FIG. 3 . The method 110 is preferably performed by a patient management device 42 but, in a further embodiment, could also be performed by a server 41 or client 23 .
[0053] Each patient management device 42 operates in two logical roles. First, as part of the physical plant of the control system implemented by the server 41 , each patient management device 42 receives patient-level control 56 , which defines the initial control strategy to be executed (block 111 ). Second, as a controller to the medical devices 43 assigned, each patient management device 42 delegates sub-goals (block 112 ), which, in a further embodiment, could also be sent to other patient management devices 42 or the server 41 . Other patient management device functions are possible. A closed control loop is then initialized (block 113 ) by verifying, as necessary, connectivity to each assigned medical device 43 and confirming satisfactory operational statuses. The continuous closed control loop (blocks 114 - 124 ) is then performed until the processing infrastructure, for instance, the patient management device 42 , terminates execution.
[0054] During each cycle (block 114 ), three threads of control are performed to receive patient-level control 56 (blocks 115 - 117 ), receive device-level feedback 50 and send device control 52 (blocks 118 - 121 ), and send patient-level feedback 54 (blocks 122 - 123 ). In the patient-level control thread, changes to the control strategy that are received as patient-level control 56 from the server 41 are monitored (block 115 ). If the control strategy has changed (block 116 ), the control parameters for the patient management device 42 , and if applicable, for one or more of the attached medical devices 43 , are revised (block 117 ). Device-level control 52 to the appropriate assigned medical devices 43 is also sent. In the medical device control thread, patient data is received as device-level feedback 50 from each assigned medical device 43 and is integrated into the state 51 for the patient management device 42 (block 118 ). The device-level feedback 50 and state 51 are analyzed against the current control strategy (block 119 ) and, if the current control strategy requires adjustment (block 120 ), device-level control 52 is sent to the appropriate assigned medical devices 43 (block 121 ). Finally, in the patient-level feedback thread, device-level feedback 50 and state 51 are processed (block 122 ) and provided as patient-level feedback 54 to the server 41 (block 123 ). Processing can include summarizing and extrapolating the patient data over those devices that constitute the physical plant of the patient management device 42 . Other types of processing are possible. Closed control loop processing (block 124 ) is performed continually, but can be subject to interruption or modification by external sources, such as direct control 53 .
[0000] Medical Device Method
[0055] Except when provided direct control 49 , each medical device 43 also functions as an autonomous event/response controller that receives physiological measures 46 from sensors 44 and delivers therapy 48 through effectors 45 , subject to patient-level control 56 delegated by an associated patient management device 42 and, in a further embodiment, the server 41 . FIG. 8 is a flow diagram showing a method 130 for providing hierarchical medical device control for automated patient management for use on a medical device 43 of FIG. 3 . The method 130 is performed by a medical device 43 .
[0056] Each medical device 43 operates in two logical roles. First, as part of the physical plant of the control system implemented by the associated patient management device 42 and, in a further embodiment, the server 41 , each medical device 43 receives device-level control 52 , which defines the initial control strategy to be executed (block 131 ). Second, as an event/response controller, each medical device 43 delivers therapy, such as pacing stimuli, and receives physiological measures. Other medical device functions are possible. An event/response control loop is then initialized (block 132 ) by confirming satisfactory operational statuses of the sensors 44 and effectors 45 . The event/response control loop (blocks 133 - 143 ) is then performed until the processing infrastructure, for instance, the medical device 43 , terminates execution.
[0057] During each cycle (block 133 ), three threads of control are performed to receive device-level control 52 (blocks 134 - 136 ), control sensors 44 and effectors 45 (blocks 137 - 140 ), and send device-level feedback 50 (blocks 141 - 142 ). In the device-level control thread, changes to the control strategy that are received as device-level control 52 from the assigned patient management device 42 and, in a further embodiment, the server 41 are monitored (block 134 ). If the control strategy has changed (block 135 ), the control parameters for the medical device 43 are revised (block 136 ), which could affect the event occurrence and response characteristics of the medical device 43 . In the sensors 44 and effectors 45 , control thread, physiological measures 46 are received from each sensor 44 and are integrated into the limited state 47 for the medical device 43 (block 137 ). The physiological measures 46 and limited state 47 are analyzed against the current control strategy (block 138 ) and, if the current control strategy requires adjustment (block 139 ), revised control is applied to the interfaced sensors 44 and effectors 45 (block 140 ). Finally, in the device-level feedback thread, physiological measures 46 and the limited state 47 are processed (block 141 ) and provided as device-level feedback 50 to the associated patient management device 43 and, in a further embodiment, to the server 41 (block 142 ). Processing can include averaging or summarizing the physiological measures 46 . Other types of processing are possible. Closed control loop processing (block 143 ) is performed continually, but can be subject to interruption or modification by external sources, such as direct control 49 .
[0000] Server Structure
[0058] Generally, the server is responsible for exercising control over the patient management devices and medical devices assigned. FIG. 9 is a block diagram showing a system 150 for providing hierarchical medical device control for automated patient management for use on the server of FIG. 3 . The server 151 implements the system 150 and executes a sequence of programmed process steps, such as described above with reference to FIG. 6 , implemented, for instance, on a programmed digital computer system.
[0059] The server 151 includes a controller 152 , input processor 153 , and output processor 154 . The server 151 also maintains an interface to the patient population database 155 . The patient population database 155 is used to maintain patient data 156 , which can include patient characteristics, wellness, treatment plans, regimens, and other types of information. The patient information 156 is maintained for those patients belonging to the population of patients managed by the server 151 as well as for other patients not strictly within the immediate patient population, such as retrieved from third party data sources 26 .
[0060] The controller 152 processes feedback 158 that can include patient-level feedback 54 and, in a further embodiment, device-level feedback 50 , and the patient data 156 , which constitutes part of the state 55 maintained by the server 151 . The state is analyzed against the current control strategy 157 to determine if changes to the current control strategy 157 are needed. Other types of analyses are possible. The feedback 158 and control strategy 157 are received by the input processor 153 , which integrates the feedback 158 into the patient data 156 stored in the patient population database 155 and provides the control strategy 157 to the controller 152 , which delegates programming 159 as sub-goals to assigned patient management devices 42 , and, in a further embodiment, medical devices 43 . The output processor 154 sends programming 159 and can also provide feedback 160 to external sources, such as clients 23 (shown in FIG. 1 ) or displays associated with the patient management device for further display and analysis. Other components and functionality are possible.
[0000] Patient Management Device Structure
[0061] Generally, each patient management device is responsible for exercising control over the medical devices assigned. FIG. 10 is a block diagram showing a system 170 for providing hierarchical medical device control for automated patient management for use on a patient management device of FIG. 3 . The patient management device 171 implements the system 170 and executes a sequence of programmed process steps, such as described above with reference to FIG. 7 , implementing, for instance, on a programmed digital computer system.
[0062] The patient management device 171 includes a controller 172 , input processor 173 , and output processor 174 . Medical device data 175 is maintained for the assigned medical devices 43 . The controller 172 processes feedback 177 that can include device-level feedback 50 , which constitutes part of the state 51 maintained by the patient management device 42 . The state is analyzed against the current control strategy 176 to determine if changes to the current control strategy 176 are needed. Other types of analyses are possible; The feedback 177 and control strategy 176 are received by the input processor 173 , which integrates the feedback 177 into the medical device data 175 and provides the control strategy 176 to the controller 172 , which delegates programming 178 as control parameters to assigned medical devices 43 . The output processor 174 sends programming 178 and can also provide feedback 179 to the server 41 and external sources, such as clients 23 (shown in FIG. 1 ) for further display and analysis. Other components and functionality are possible.
[0000] Medical Device Structure
[0063] Generally, each medical device is responsible for monitoring physiological measures and providing therapy to the patient 14 . FIG. 11 is a block diagram showing a system 190 for providing hierarchical medical device control for automated patient management for use on a medical device of FIG. 3 . The medical device 191 implements the system 190 and executes a sequence of programmed process steps, such as described above with reference to FIG. 8 , implemented, for instance, on an embedded microprocessor-based system.
[0064] The medical device 191 includes a controller 192 , input processor 193 , and output processor 194 . Staged measures 195 are maintained for the sensors 44 . The controller 192 processes physiological measures 197 , which constitute part of the limited state 47 maintained by each medical device 190 . The limited state 47 is analyzed against the current control strategy 196 to determine if changes to the programming are required. Other types of analyses are possible. The physiological measures 197 and control strategy 196 are received by the input processor 193 , which integrates the physiological measures 197 into the staged measures 195 and provides the control strategy 196 to the controller 192 as programming that is implemented to change the event occurrence and response control performed by the medical device 190 . The output processor 194 delivers therapy 198 to the patient 14 and can also provide feedback 199 to the associated patient management device 42 and, in a further embodiment, the server 41 , plus external sources, such as clients 23 (shown in FIG. 1 ) for further display and analysis. Other components and functionality are possible.
[0065] While the invention has been particularly shown and described as referenced to the embodiments thereof, those skilled in the art will understand that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention. | A system and method for providing hierarchical medical device control for automated patient management is presented. A processor is operatively coupled to a plurality of medical devices on a substantially continual basis to receive sensor data. A control strategy is assigned to the processor to specify actions to be taken by the medical devices to affect the attainment of a therapy goal. State is maintained, selected from the group comprising a history of changes to the control strategy and past sensor data received from the medical devices. Feedback is periodically received. The feedback includes new sensor data from the medical devices. The feedback and the state are analyzed against the actions specified in the control strategy. Control is provided to one or more medical device in response to an actionable change from the actions specified in the control strategy. | 0 |
FIELD OF THE INVENTION
The present invention relates to non-destructive testing and inspection (NDT/NDI) and more particularly to a method of improving user interface functionality of NDT/NDI instruments by employing overlaying process combining hand-drawn information on a touch-screen with digital inspection data acquired from a NDT/NDI process.
BACKGROUND OF THE INVENTION
The measurement data from NDT/NDI instruments used for the routine monitoring of structural integrity must be sufficiently accurate to allow a valid assessment to be made on the condition of the structure under test. Examples of such structures are pipes and vessels which are widely used in the petrochemical and other industries. Examples of measurement or inspection data are pipe wall thickness and other geometric conditions, including, but not limited to, the presence of irregularities (e.g. corrosion, oxidation, etc.) and flaws (e.g. porosity, cracks, etc.).
Presently, some advanced NDT inspection instruments are equipped with graphical display, touch sensitive display (touch screen) and keyboard. In these instruments, touch sensitive displays are often used as a versatile keyboard by displaying virtual keys, which can be activated upon being pressed. Although it represents some major improvements by using these existing touch-screen-enabled instruments, however, in many cases, input methods allowed for users are limited to predefined formats. When this is the case, users cannot make input that does not respect the predefined formats. Most of time, these formats are alpha numeric and are entered by means of a keyboard and/or keys.
Another major drawback of these existing touch-screen enabled NDT/NDI instruments is that information being entered via touch screen is not correlated with graphical display of digital inspection data, limiting the usefulness of the touch screen input.
In NDT applications, one of the most import aspects of user interest is on the graphical display of inspection data, which is often generated based on digitized inspection data. It describes an inspected subject and some particularities of its condition. This information is only valid in a precise context and timing of an inspection session for a precise subject, which together with the acquired inspection data, forms a complete context of the inspection.
When the inspection data is saved in a media for later processing, the user would need this complete inspection context to be able to process, analyze and/or interpret the inspection data. It is a common practice that the user needs to identify the precise context associated with the specific inspection for later reference.
When using digital NDT inspection instruments equipped with graphical display, there are a lot of details and information presented to the user. This is currently available however not convenient to use in most of existing digital NDT inspection instruments. Particularly, it is not always easy, fast and practical for a user to identify and describe a precise element of information displayed on a graphical display and to make notes by using the existing of alpha numeric input formats provided by either touch screen virtual buttons or keyboards.
The specific challenge herein dealt with is to provide a method of combining touch screen (free form) user input information with the information acquired from digital inspection for the specific timing, geometry and context of the inspection session. This will ameliorate the cumbersome maneuvers of virtual or keyboard buttons.
Existing efforts related to usage of touch screen are found in some patents as follows.
U.S. Pat. No. 6,266,685B1 discloses a mechanical apparatus that can be employed for usage of a stylus in a handheld application. It does not address the type of information that is allowed to be entered or the link between the stylus entered information and other information available in the instrument.
Patent US20090256817A1 concerns more of a technology enabling the touch screen to sense pressure or touch more effectively and communicate the touch screen input accurately to the processor. It does not deal with providing a solution to link the touch-screen input with specific inspection information.
Patent WO2003090097A1 teaches a system that receives hand written information and transfers this information to some other system by means of an email.
As can be seen, existing efforts do not provide a solution of overlaying, combining or connecting hand-drawn touch-screen input with information acquired from inspection. Accordingly, a solution is much needed to overcome the drawbacks presented by existing touch-screen NDT/NDI instruments which require fixed-form touch screen input and/or do not provide compounded display of the touch-screen input and the inspection information.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide a system and method for overlaying, combining or connecting free-form touch-screen input with NDT/NDI inspection information. The resulting user interface functionality for digital NDT instruments allows users to make touch-screen input and later review and analyze the touch screen input in a complete context of an inspection session such as timing, waveform and geometric information of a defect.
It is another objective of the present invention to provide an instrument and method that allows the user make free-form hand notes or drawings directly on a touch sensitive display of the instrument and then gives the user an option to overlay the hand-drawing information with the digital inspection display already available in the instrument.
Yet it is another objective of the present invention to provide an instrument and method that allows the user to make touch screen input in both free-form or pre-fixed formats then overlays the input in both formats with the specific digital inspection result.
The foregoing and other objectives of the invention are realized with a non-destructive instrument configured according to the present disclosure.
In accordance to various embodiments of the system and method of the present disclosure presents the advantages for interface functionality which significantly improves the versatility and efficiency of the usage of NDT/NDI instruments. Other advantages include the improvements in the usability of inspection data.
Other features and advantages of the present invention will become apparent from the following description of the invention that refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing an NDT instrument with a touch-screen and display overlay feature according to the presently disclosed invention.
FIG. 2 is a flowchart diagram describing software modules or steps enabling the touch-screen input and display overlay in the preferred embodiment.
FIG. 3 is a schematic diagram showing an exemplary usage of the interface feature according to presently disclosed embodiment.
FIG. 4 is a schematic diagram showing the layers of information that are compounded during an exemplary overlaying process according to the presently disclosed embodiment.
FIGS. 5 a , 5 b and 5 c are exhibition of steps or process executed during some exemplary operations using the instrument devised with the presently disclosed embodiment.
DETAILED DESCRIPTION OF THE INVENTION
It should be noted that the term ‘real-time measurement’ is used in the present disclosure to mean the immediate measurement result provided to the user or external device by measurement device 101 ( FIG. 1 ). The measurement result may be provided to the user by means of display 104 ( FIG. 1 ). The measurement result may be comprised of, but not limited to, graphical display, such as waveforms or numerical values representing thickness, defects, damages or flaws of various kinds and/or an alarm indication.
The present invention is now described hereinafter with reference to the accompanying drawings, in which some examples of the embodiments of the inventions 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 by way of example so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
FIG. 1 illustrates schematically a digital NDT inspection instrument 101 in which an embodiment of the present invention is included. Instrument 101 is equipped with a touch sensitive graphic display 104 . It is also equipped with other user interface input and output means such as like a keypad 111 , another keypad on the right side 112 , a power key 102 and a stylus 103 , which all can be part of an existing NDT instrument. Further included in the preferred embodiment are a save key 105 , an “overlay” virtual key 109 and a “clear” virtual key 108 , which represent one of the novel aspects of the preferred embodiment.
It can be appreciated that the keypads and arrangement of keypads shown in FIG. 1 and as described above are only one example of many possible forms. Variations in them do not affect the scope of the present disclosure.
A probe 115 is connected to the instrument for performing predetermined inspection on a test object 118 . Probe 115 can be configured to provide output signal. The nature of the probe, probe signals or test object does not affect how the preferred embodiment works in this disclosure. Instrument 101 preferably transforms the signal returned by the probe from its original input, mostly in an analog form, to a digitalized form. The digitalized signal is then processed and plotted by instrument 101 as inspection result 107 which is displayed on the touch sensitive graphical display 103 .
Similar to some conventional NDT/NDI instrument, 101 can be configured to control some characteristic of the output signal and the preference of the characteristics of the digitized signals and the content of the display. The exemplary waveform 107 shown in FIG. 1 is of a typical digitized ultrasonic echo signal which, under typical inspection sessions, changes versus time and refreshes automatically at a predetermined data display rate.
Continuing with FIG. 1 , according to the preferred embodiment, if the operator notices a flaw or anything that warrant a more detailed future analysis on waveform 107 , the operator might choose to pause or freeze the display so that it does not refresh at the normal display rate. The capability of freezing a display is provided by many existing NDT instrument. One of the novel aspects of present invention is to allow the operator to enter touch-screen information (herein as “touch-screen input”) on top of the frozen waveform on the touch sensitive graphical display 104 and to overlay the information contained in the touch-screen input with the digital information represented by waveform 107 . The touch-screen input can be of free-form, or in a pre-fixed form, such as being tabbed in a predetermined form shown on screen. The capability allows the touch-screen input to be placed in the complete context of the inspection session, including the instant status of the waveform, the location of the particular concern, the geometry of the test object, etc.
Instrument 101 further comprises a computation module 122 , which is preferably loaded on a digital processor 116 . Computation module 122 functions to process the touch screen input, perform overlay requirement and providing overlay display as requested by the operator. Module 122 can be a block of stand-alone software or firmware, or, most preferably is a part of the conventional data processing of NDT instrument 101 . Instrument 101 further comprises a memory 120 which can be a detachable external memory or a part of the existing memory of instrument 101 .
It can be appreciated by those skilled in the art that computation module 122 is preferably loaded on and executable by processor 116 . Processor 116 and memory 120 are preferably assembled on a circuit board, which is together enclosed within instrument 101 . In order not to block display 104 and other display features, memory 120 and the computation module 122 are placed outside the instrument in FIG. 1 only for illustrative reasons.
Before continuing with the further disclosure, it should be noted that FIG. 1 should still be continuously referred back when reference is made to other figures.
Reference now is made to FIG. 2 , which illustrates a process or steps involved in operating the instrument embodying the touch sensitive display ( 104 ) and the novel configuration for overlaying the touch-screen input with inspection results according to the present disclosure. As can be appreciated, the steps herein presented are exemplary for illustrating purpose. Alternative steps associated with some specific types of NDT instruments can be employed within the scope of the present disclosure.
As shown in FIG. 2 , there are two main branches of steps, one led by steps 201 to the left-hand and the other led by step 203 to the right-hand, with the former relates more to the usage of making touch-screen input, the latter relates to existing instrument functions, respectively; however, both branches are necessary to make use of the embodiment according to the present disclosure. It should be noted that the steps or process in the two branches are independent steps and there's no definitive relationship in timing-wise between one and another. In another word, the steps related to touch-screen input and overlaying can be interjected at any point, before, during or after an inspection session. In addition, steps to the right hand side can vary from one particular operation to another.
As for each new inspection or inspection review session, at step 202 , instrument 101 is powered on. The user has a choice to load a complete context of one of the past inspections, which includes the information of a specific inspection setup, information on the object being inspected and the inspection results. If the user decides not to load a past inspection, the user needs to start a new inspection to gather inspection data to process. At step 207 , instrument 101 can be initialized to default ( 207 ). Step 207 can be executed by the user or automatically. It can also be optional. Initialization to default will set inspection complete context to a default state.
Similar to the experience of using many existing NDT instruments, user can manually modify some inspection parameters in the instrument. These parameters can be included in instrument setup 208 or being modified in step 209 . They can also be included in the step for setting up subject information and modified by step 210 which is optional depending from inspection to inspection.
Again, similar to any existing digital NDT instrument, presently disclosed instrument 101 can be configured to control some characteristic of the outputted signal and some characteristics of the digitalization of the altered signal. In step 209 , these configurable parameters can be grouped together and named “Inspection setup”.
To acquire new inspection data, the instrument is set in acquisition state or to manually start the acquisition at step 212 . This step could be optional if the instrument is set to acquisition state by default at step 207 .
Still referring to FIG. 2 , attention is now turned to the process of making touch-screen input and overlaying such information with the inspection result obtained either at step 206 or 220 .
One novel aspect of the embodiment in the present disclosure includes an “overlay mode” configured for instrument 101 . Before, during or after an inspection session, the user can initialize the overlay mode in step 211 at anytime by pressing a button or virtual key, such as overlay virtual key 109 . It should be noted that, without initializing the overlay mode, the user can preferably sketch any information on the touch screen 104 ; however the information will not be saved or overlaid until the user initialize the overlay mode by pressing overlay virtual key 109 (shown in FIG. 1 ). After the overlay mode is initialized, touch-screen input can be saved into the instrument.
In step 214 , under the overlay mode, the user can make any input on the touch screen either using a given stylus or by hand, depending on the design of the touch screen.
Likewise, in step 215 the user can at any time exit the overlay mode by pressing a button or virtual key designed for such function, or virtual key 109 again in this exemplary case. The touch-screen input will not be saved in this design, unless the save command or button 105 is pressed in step 218 .
If the user needs to clear the display overlay, he can do so by pressing “clear” key 108 in this exemplary case in step 213 .
At any moment, the user can press the “save key” ( 105 in FIG. 1 ) in step 218 to save/store the current on screen information, which include the touch-screen input, the specific timing and occasion of the waveform and the complete context of an inspection session into internal or external media ( 120 ).
Also worth noting in FIG. 2 is another feature conceived in the present invention shown in step 216 , in which when the user presses one of the designated virtual keys or buttons, a popup question window shows up on the screen with a form specifically related to the context of the operation or inspection. For instance, the pop-up form may be to ask the user to categorize the severity of a particular defect as identified by a hand drawn circle with one of the three choices, namely low, medium or high. The nature and the format of information are more specific because it is related to the inspection concurrently performed. The content of the form preferably is determined by the context of the instant inspection event, such as a gate event when the signal has crossed a certain threshold. There can be a predetermined the number of forms corresponding to a number of inspection events.
It can be understood by those skilled in the art that the steps in FIG. 2 , 211 ˜ 217 are all independent operational steps determined by the operator as to when to initialize and when to end. They are not necessarily sequentially related.
When save button 105 is pressed, one important novel aspect of the present disclosure is that the instrument is further configured to “stack” together all the information entered in the process above and saved into memory 120 . The “stacked” information may include any of the following: the inspection data captured either in step 206 or 220 , the free form touch-screen input made in step 214 , the popup information from step 217 , the instrument setup ( 208 ), the inspection setup ( 209 ) and the subject information ( 210 ). The method to correlate all the saved information is further explained later in association with FIG. 4 . The overlay-saving action collects together all the information related to a specific inspection event and makes it available in the instrument that maybe needed to analyze and/or process the inspection data.
It can be appreciated that the visual aspect of the entire screen display at the specific moment when the complete inspection context is saved with the corresponding touch-screen input provides convenience and valuable information for data analysis.
Reference is now made to FIG. 3 , wherein a sample case of the invention with some exemplary look of the user interfaces embodied by the instrument of the present disclosure. As can be seen, in interface 301 , the user presses “overlay” button to enter into overlay mode on the touch-screen, while looking at a digital display of the waveform shown on the screen. This corresponds to step 211 in FIG. 2 . In interface 302 , the user circles a spot with a flaw suspected using the touch-screen, which corresponds to step 214 in FIG. 2 . In interface 303 , the user presses virtual key again, in the exemplary design, to prompt a popup window 304 to invite user enter fixed-format information specifically related to what's circled in 110 . This corresponds to steps 216 and 217 in FIG. 2 .
Reference is now made to FIG. 4 which shows a representation of displayed layers of different kinds of information, their relationship and the method of correlating them, or the method of “overlaying” the layers.
It should be noted that what is displayed on screen display 104 does not necessarily have the same form in image processing in the instrument. In this example shown in FIG. 4 , there are four visual components that are mixed together to produce what is effectively displayed on the screen. These components can be named “layers”. Each layer contains information provided by a specific entity. In this example there is the “overlay control layer” 401 , the touch-input layer 402 , the “user interface layer” 403 and the “inspection data layer” 404 .
The information in overlay control layer 401 shown as the most upper displayed layer in this example overwrites information from all other display layers when display layers are overlaid or mixed. This layer is also preferably used to display overlay virtual key 108 .
Continuing with FIG. 4 , touch-input layer 402 is the second most upper display layer in this example. It overwrites every other layer except the overlay control layer 401 . It is important for the invention that this layer to be in the second most upper layers to allow the user to enter touch-screen information 409 over information already displayed.
User interface layer 403 is the display layer used to display and receive control command for inspection controls 411 which can include any information to be used by the user to interact with instrument 101 . Interaction includes modification of the instrument setup or any other setup except overlay control. It is also the layer on which information other than the “inspection data” is displayed. This information could be the date, time, battery level, menus, etc.
Inspection data layer 404 is the display layer on which digitalized inspection information 107 is displayed. It is the lowest or deepest display layer; therefore display on this layer 404 that overlaps displays on any other layer will be overwritten. Preferably, a special section of the screen is reserved for information from this display layer to make sure no inspection data is erased or over-written.
Still referring to FIG. 4 , all the layers shown, or any combination of any number of layers shown can be mixed or overlaid together to produce what is displayed on the screen 104 . Many commercially available tools for overlaying or mixing the above can be used. It can be appreciated that no matter what kind of mixing tools are used for the purpose of overlaying the above layers, the methods or technique all fall with the scope of the present disclosure.
The instrument of the present disclosure also embodies a layer of touch or pressure sensitive material shown as 407 . Layer 407 is not a display layer which is controlled by mostly software modules or coding. This is a physical layer comprised of touch sensitive material and translating touch trajectory to electronic signals to the instrument, which is displayed in layer overlay 402 .
One important aspect shown in FIG. 4 is a common coordinate 405 shared by all the layers discussed above. Common positioning and sizing shared by all layers are controlled by this common coordinate 405 , which is important to make sure information across all layers match geometrically.
Yet one more important aspect of the present disclosure shown in FIG. 4 is that each “layer” except touch sensitive material also represents a coding sub-module or sub-block that constitutes a part of computational module 122 of FIG. 1 , which is executed by digital data processor 116 that's normally used by typical NDT instrument.
As can be seen, the resultive display 106 compounded all the layers as described above.
Reference is now made to FIGS. 5 a , 5 b and 5 c , with continuous reference back to FIGS. 1 , 2 and 4 . FIG. 5 show some flowcharts describing the steps of processing display layers or the relationships among the coding modules represented by their corresponding layers during some simple but common use cases embodying the present invention.
Steps 501 to 505 elaborate step of 214 in FIG. 2 for entering touch screen input on touch sensitive display. In steps 501 and 502 , the user enters information on touch sensitive display layer 407 at a precise position in coordinate 405 and stores such information in memory space 120 . In step 502 , computational module 122 calculates coordinate information and set information at this coordinates into overlay display layer 402 . In step 503 , computational module 122 mixes together overlay control layer 401 , touch-input layer 402 , user interface layer 403 and inspection data layer 404 . In step 504 result of mixing all display layers memory spaces is processed by computational module 122 and displayed on the graphical touch sensitive display 106 .
Referring to FIG. 5 b , steps 506 to 508 elaborate step 215 in FIG. 2 for executing event when overlay virtual key is pressed. In step 507 touch-input layer 402 information is stored in a display overlay file in memory 120 of FIG. 1 for later use.
Referring to FIG. 5 c , steps 509 to 511 elaborate step 218 for executing the event when save button is activated. In step 510 display overlay file in FIG. 5 b is copied into a full context 305 as shown in FIG. 3 .
It is to be understood that embodiments of the invention may be embodied as a software or firmware program, as software and hardware, or as hardware and/or circuitry alone. The features disclosed and explained herein may be employed in any computerized devices and software systems for non-destructive devices.
Although the present invention has been described in relation to particular exemplary 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 not be limited by the specific disclosure. | A system and method for overlaying, combining or connecting touch-screen input either in free-form or fixed form, with NDT/NDI inspection information. The resulting user interface functionality for digital NDT instrument allows users to make touch-screen input in unrestricted or restricted format and later review and analyze the touch screen input in a complete context of an inspection session such as timing, waveform and geometric information of a defect or measurement target. | 6 |
TECHNICAL FIELD
[0001] The present invention generally relates to electronic user interfaces, and more particularly relates to an apparatus for controlling the movement of an object on a plane.
BACKGROUND
[0002] Increasingly, vehicles are being configured with electronic display systems that depict a plurality of images. These electronic display systems may include a cursor control device for manipulating a movable cursor on these images. These cursor control devices may be any one of a number of cursor control devices, including a mouse control, a joystick control, or a trackball control. Electronic display systems provide a user with useful information regarding the state of the vehicle, the surrounding area, or other data regarding the vehicle's environment.
[0003] While the use of standard cursor control devices on a vehicle is effective, it does suffer from certain drawbacks. For example, the use of a mouse control requires an immobile flat surface that the control slides across to direct the movement of the cursor. However, the surfaces inside of a moving vehicle vibrate and are subject to other forces that make the use of a mouse control difficult. In addition, it is possible for the mouse control to slide completely off of a surface of the vehicle when the vehicle turns or stops suddenly. In addition, while the use of a joystick control or a trackball control may be better suited for use in a vehicle (e.g., because these controls are coupled to a base), many users prefer to use a mouse control as it provides them with an intuitive sense for directing the movement of a cursor.
[0004] Accordingly, it is desirable to provide a cursor control device for use on a vehicle that is not affected by vibrations and other forces. In addition, it is desirable to provide a cursor control device that has the same intuitive feel as a mouse control. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.
BRIEF SUMMARY
[0005] An apparatus is provided for controlling the movement of an object on a plane. The apparatus comprises a basin, a movable object positioned within the basin, and a sensor coupled to the apparatus for detecting the movement of the movable object within the basin, wherein the movement of the object on the plane is related to movement of the movable object within the basin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
[0007] FIG. 1 . is a cross-sectional view of a device for controlling the movement of an object on a plane according to a first embodiment of the present invention;
[0008] FIG. 2 is a cross-sectional view of a device for controlling the movement of an object on a plane according to a second embodiment of the present invention; and
[0009] FIG. 3 is a block diagram of a system for controlling the movement of a cursor on an electronic display.
DETAILED DESCRIPTION
[0010] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
[0011] FIG. 1 is a cross-sectional view of a device 10 for controlling the movement of an object on a plane according to a first embodiment of the present invention. As further described below, in one embodiment device 10 comprises a cursor control device for controlling the movement of a cursor on an electronic display. The cursor control device may be used on a vehicle (e.g., ground, air, space, or submersible) or at any other location where a user interacts with an electronic display. It will be understood by one who is skilled in the art that device 10 may be used to control any object that moves on a plane, such as a robotic pen, a milling machine having a cutting apparatus that moves about two axes, or a vehicle that travels on a surface.
[0012] As depicted, device 10 includes a base 12 , a basin 14 , a movable object 16 , a spring 18 , and a sensor 20 . The base 12 includes a bottom 22 , a top 24 , and one or more sides (e.g., two as shown) 26 , 28 . The bottom 22 is of sufficient shape and size to provide support for device 10 . The top 24 of base 12 is positioned above the bottom 22 and is supported by the sides 26 , 28 . The bottom 22 , top 24 and sides 26 , 28 of base 12 form an inner chamber 32 .
[0013] Basin 14 having a predetermined curvature is formed in the upper surface of the top 24 of base 12 . In one embodiment basin 14 is circular. The curvature of basin 14 is determined based on desired characteristics of device 10 such as its desired size or the range of movement of movable object 16 described below. Basin 14 also includes an opening 34 positioned at its center. The opening 34 extends through basin 14 to inner chamber 32 .
[0014] Movable object 16 is normally positioned at the center of basin 14 , and has larger dimensions than opening 34 , preventing it from passing through opening 34 . The user of device 10 slides the object 16 along the surface of basin 14 to control the movement of a cursor on an electronic display (or any object that moves along a plane) in a fashion similar to the use of a mouse control. Object 16 follows the curvature of basin 14 providing the feeling that it is pivoting about a point above device 10 as it moves from one side of basin 14 to another. Object 16 and basin 14 may each comprise a low-friction material to allow for smooth and low effort motion. In one embodiment, object 16 is a substantially circular disc having a curvature that is substantially complementary to the curvature of basin 14 .
[0015] Movable object 16 is coupled to bottom component 22 of base 12 via spring 18 . Spring 18 is coupled to movable object 16 at one end, passes through opening 34 of basin 14 , and is coupled to the bottom 22 of base 12 at the opposite end. Spring 18 is in its relaxed state when movable object 16 is positioned at the center of basin 14 . As movable object 16 is displaced from the center of basin 14 , spring 18 deflects away from its relaxed state. When movable object 16 is released, spring 18 returns to its relaxed state and causes movable object 16 to return to the center of basin 14 . Thus, spring 18 biases object 16 toward the center of basin 14 . In addition, spring 18 constrains the movement of movable object 136 preventing it from being removed from basin 134 due to vibrations or other forces inside of the moving vehicle. The spring 18 and the curvature of basin 14 work together to restrict the movement of movable object 16 within a predetermined range of motion. For example, the range of motion for the movable object 16 may be restricted to basin 14 such that movement of object 16 is inhibited when its edge meets with the outer rim 36 of basin 14 . Although in the depicted embodiment the movement of movable object 16 is constrained via spring 18 , it should be noted that other restraint devices may also be used. For example, a retractable cord or any other mechanism may be coupled to movable object 16 and to base 12 to constrain the movement of movable object 16 .
[0016] Sensor 20 detects the movement of the object 16 within the basin 14 . In the depicted embodiment, sensor 20 is an optical sensor mounted near the rim of opening 34 . As object 16 slides along the surface of basin 14 , optical sensor 20 generates motion signals that describe the movement of object 16 . When object 16 is lifted away from the surface of basin 14 , sensor 20 is unable to detect its movement or to generate motion signals.
[0017] Other types of sensors may also be used with embodiments of the present invention. For example, FIG. 2 is a cross-sectional view of a device 50 for controlling the movement of an object on a plane according to a second embodiment of the present invention. As depicted, device 50 includes a base 52 that comprises a bottom 54 , a top 56 , and one or more sides 58 , 60 . The bottom 54 , top 56 , and sides 58 , 60 form an inner chamber 62 . A basin 66 is formed into the upper surface of the top 56 of base 52 . Basin 66 has an opening 67 in its center that extends into the inner chamber 62 . A movable object 68 is positioned in basin 66 . In this embodiment, movable object 68 also includes a downwardly extending stem 70 that extends through opening 67 into the inner chamber 62 . A magnet 72 is coupled to the end of stem 70 and a Hall Effect sensor 74 is mounted to the bottom 54 of base 52 , directly beneath the magnet 72 . Hall Effect sensor 74 detects movement of the magnet 72 when the movable object 68 is displaced and generates motion signals describing that movement.
[0018] In addition, this embodiment includes a conically shaped spring 76 for biasing movable object 68 toward the center of basin 66 and constraining its movement as described above. The spring encompasses stem 70 , magnet 72 , and Hall Effect sensor 74 . In other embodiments, spring 76 may comprise a plurality of smaller springs formed in a conical arrangement around stem 70 , magnet 72 , and Hall Effect sensor 74 . In addition, in still other embodiments magnet 72 may be placed within movable object 68 and Hall Effect sensor 74 may be placed near the rim of opening 67 .
[0019] FIG. 3 is a block diagram of an exemplary system 100 for use with embodiments of the present invention. As depicted, the system 100 includes a cursor control device 110 , a processor 120 , and an electronic display 130 . The cursor control device 110 corresponds to device 10 of FIG. 1 (or, alternatively, device 50 of FIG. 2 ). The cursor control device 110 is coupled to the processor 120 and includes a base 132 , a basin 134 , and a movable object 136 positioned in the center of the basin 134 . Object 136 is movable within a coordinate system 138 having X and Y-axes. Movement of object 136 is constrained to a predetermined range of motion. A sensor (e.g., the sensor 20 of FIG. 1 ) on the cursor control device 110 generates motion signals that describe the movement of movable object 136 within basin 134 .
[0020] The electronic display 130 is coupled to processor 120 and includes a display area 142 . The display area 142 displays an image that includes a cursor 144 that is movable within a coordinate system 146 which corresponds to coordinate system 138 of the cursor control device 110 . As described below, the movement of the cursor 144 within the image depicted in display area 142 is based on command signals that the electronic display 130 receives from the processor 120 in response to the motion signals that the processor 120 receives from the cursor control device 110 .
[0021] Processor 120 is coupled to cursor control device 110 and electronic display 130 . It receives motion signals describing the movement of movable object 136 within basin 134 from cursor control device 110 . In response to these motion signals, processor 120 determines the proper position for cursor 144 on the image depicted in the display area 142 and transmits a command signal to the electronic display 130 . The electronic display 130 displays the cursor 144 in the appropriate position.
[0022] The processor 120 moves cursor 144 across the image depicted on display area 142 in accordance with one of a plurality of modes. In a first mode (e.g., an absolute mode) each position within the range of motion of movable object 136 corresponds to a predetermined position of cursor 144 on the image depicted in display area 142 . Thus, the position of cursor 144 is at all time synchronized to the position of movable object 136 and the user may position cursor 144 at a desired location on the image by positioning movable object 136 at a corresponding position within basin 134 .
[0023] For example, the normal position of movable object 136 (e.g., the center of the basin 134 ) may correspond to the center of the image and each position at the border of the range of motion of movable object 136 may correspond to a position on the border of the image. In this case, when movable object 136 is positioned at the center of basin 134 , the processor 120 positions cursor 144 at the center of the image depicted on the display area 142 . If the user moves object 136 to a position at the border of its range of motion, processor 120 moves cursor 144 in a synchronized manner to a corresponding location on the edge of the image. Further, if movable object 136 is moved to a position 170 within basin 134 that corresponds to position 180 on the image depicted in the display area, processor 120 moves cursor 144 in a synchronized manner to the corresponding position on the image.
[0024] In a second mode of operation (e.g., a relative mode) movement of movable object 136 within basin 134 results in a corresponding movement of cursor 144 on the image depicted in display area 142 . However, the position of cursor 144 on the image does not necessarily correspond to the position of movable object 136 within basin 134 . For the purposes of describing the movement of movable object 136 and cursor 144 in relative mode, the origin of coordinate system 138 will at all time be positioned at the center of movable object 136 and the origin of coordinate system 146 will at all times be positioned at the center of cursor 144 . In this mode, if the user desires to move cursor 144 from its current position (e.g., the center of the image) to position 180 , the user moves object 136 in a direction within coordinate system 138 that corresponds to the direction of position 180 with respect to the origin of coordinate system 146 . Cursor 144 moves in the direction at a speed that corresponds to the speed of movable object 136 . Further, if the user then desires to move cursor 144 from position 180 to position 190 on the image depicted in display area 142 , the user moves object 136 from its current position in a direction within coordinate system 138 that corresponds to the direction of position 190 with respect to the origin of coordinate system 146 .
[0025] If movable object 136 reaches the border of its range of motion before cursor 144 reaches a desired location on the image, the position of movable object 136 must be reset within basin 134 before cursor 144 can continue moving toward the desired location. In one embodiment, movable object 136 may be reset by lifting it upward against the force of the spring 18 ( FIG. 1 ) and away from the surface of basin 134 and the sensor 20 ( FIG. 1 ). Movable object 136 may then be moved away from the border of its range of motion, set back down at desired location on the surface of basin 134 , and moved in the appropriate direction. This process may repeat until cursor 144 reaches the desired position.
[0026] In a third mode of operation (e.g., a rate mode), cursor 144 moves on the image depicted in display area 142 in a direction that is based on the position of movable object 136 with respect to the center of basin 134 and at a speed that is determined by the distance between the center of movable object 136 and the center of basin 134 . In rate mode, the origin of coordinate system 138 is positioned at all times at the center of basin 134 and the origin of coordinate system 146 is positioned at the center of cursor 144 . The movable object 136 may be displaced from the center of the basin 134 to position 170 . This displacement can be described by a vector 250 beginning at the origin of coordinate system 138 (e.g., the center of basin 134 ) and ending at position 170 . In response, the processor 120 moves the cursor 144 across the image in the display area 142 in a direction within coordinate system 146 that corresponds to the direction of vector 250 within coordinate system 138 . Cursor 144 accelerates in the appropriate direction until it reaches a speed that corresponds to the magnitude of vector 250 (e.g., the distance between the center of movable object 136 and position 170 ). If the user desires to change the direction or speed of cursor 144 , the user may move object 136 to another position 255 within basin 134 . In this case, vector 260 describes the new position 260 of movable object 136 . Processor 120 would then move cursor 144 in a direction with respect to coordinate system 146 that corresponds to the direction of vector 260 within coordinate system 138 and the speed of cursor 144 would change to correspond to the magnitude of vector 260 (e.g., the distance between the center of basin 134 and position 255 ). When the movable object 136 is returned to the center of the basin 134 , movement of the cursor 144 ceases.
[0027] Finally, in a fourth mode of operation (e.g., an acceleration mode) the cursor 144 accelerates across the image depicted in the display area 142 in a direction that is based on the orientation of the movable object 136 with respect to the center of basin 134 and at a rate that is based on the distance between the center of basin 134 and the center of movable object 136 . In acceleration mode, the origin of coordinate system 138 is positioned at all times at the center of basin 134 and the origin of coordinate system 146 is positioned at the center of cursor 144 . When movable object 136 is displaced from the center of the basin 134 to position 170 , processor 120 accelerates cursor 144 on the image depicted in display area 142 in a direction that corresponds to the direction of vector 250 . The acceleration of cursor 144 depends on the distance between the centers of basin 134 and position 170 . If movable object 136 is moved further away from basin 134 , processor 120 will cause cursor 144 to accelerate in the appropriate direction at in increased rate. Conversely, if movable object 136 is moved closer to basin 134 , processor 120 accelerates cursor 144 in the appropriate direction at a decreased rate. When the movable object 136 is returned to the center of the basin 134 , processor 120 causes cursor 144 to move across the image at a constant rate (e.g., with no acceleration because the distance between the center of basin 134 and the position of movable object 136 is zero). To stop the movement of the cursor 144 , the user must move the movable object 136 in a direction that is opposite of the direction of movement of the cursor 144 , causing the cursor to decelerate and ultimately stop moving.
[0028] It should be noted that although four exemplary modes of operation for controlling cursor 144 in response to movement of movable object 136 are described herein, other modes of operation may also be used. In addition, the cursor control device 110 may be used to interact with menus, lists, or other graphical user interface controls displayed in the display area 142 . For example, movement object 136 along the Y-axis of coordinate system 138 may enable the user to scroll through a menu or list that is depicted in the display area 142 . Further, movement of object 136 in a positive direction along the X-axis of coordinate system 138 may enable the user to select an object from the menu or list or proceed to a next menu and movement of object 136 in a negative direction along the X-axis of coordinate system 138 may enable the user to undo the last menu selection or move back to a previous menu.
[0029] In addition, although the embodiment of the present invention described in FIG. 3 is directed at a system 100 that includes a cursor control device 110 for controlling the movement of a cursor 144 in a display area 142 , it should be noted that in other embodiments the devices described above with respect to FIGS. 1 and 2 may be used to control other objects that move on a plane. In these embodiments, the object moves on the plane in response to movement of a movable object (e.g., the movable object 16 of FIG. 1 ) within in basin (e.g., the basin 14 of FIG. 1 ) in substantially the same manner as cursor 144 moves in the display area 142 in response to movement of movable object 136 according to a mode of operation as described above.
[0030] While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims. | An apparatus is provided for controlling the movement of an object on a plane. The apparatus comprising a basin, a movable object positioned within the basin, and a sensor coupled to the apparatus for detecting the movement of the movable object within the basin, wherein the movement of the object on the plane is related to movement of the object within the basin. | 6 |
FIELD OF THE INVENTION
This invention pertains to electronic delay lines and, in particular, tuneable electronic delay lines for feedforward amplifiers.
BACKGROUND
In cable communication systems it is often necessary to transmit signals long distances over coaxial cables. The strength of the transmitted signals decreases in proportion to the length of the cable over which the signals are transmitted, necessitating amplification of the signals at repeated intervals along the cable to maintain adequate signal strength. The electronic amplifiers used to amplify the signal inherently distort the signal as they amplify it. Ideally, such distortion is to be eliminated or reduced to some acceptable minimum level.
Feedforward amplifiers are able to provide relatively distortion-free amplification by extracting from the amplified signal a signal component representative of the distortion introduced by the amplifier, phase inverting that component, and then recombining the phase inverted distortion component with the amplified signal. The phase inverted distortion component cancels the distortion component in the amplified signal, leaving a relatively distortion-free amplified signal for transmission along the cable. To avoid further distortion, the signals must coincide precisely in time when they are recombined. To ensure such coincidence, delay means are provided to delay the signals and thereby compensate for time delays which arise when the signals pass through the various electronic components in the amplifier.
Two major design criteria govern the selection of a suitable delay means for inclusion in a feedforward amplifier. First, the delay means must delay signals passing therethrough for a precise time interval. For feedforward amplifiers passing signals in the 50 MHz-400 MHz band, the appropriate delay is on the order of a few nanoseconds, but the precise time delay required will vary from one amplifier to another. The second major design criterion requires that the delay means be matched to the impedance of the transmission cable in order to minimize attenuation of the signal.
One prior art technique utilized a short length of coaxial cable for the delay means in a feedforward amplifier. Because the delay means was constructed of cable identical to that comprising the main transmission cable, excellent impedance matching was obtainable. However, in order to adjust the time delay provided by such a coaxial cable segment, it is necessary to trim short pieces from the segment on a trial and error basis until the time taken for a signal to pass through the cable segment equals the desired time delay. This technique is extremely cumbersome and is not economically adaptable to the large scale volume production of feedforward amplifiers. Furthermore, the relatively bulky nature of such cable segments (about six feet of cable are typically required in each delay means) makes it difficult to package the amplifier which is preferably made as small as possible. In addition, the time delay characteristics of a cable segment are subject to change with temperature and so the vital design criteria mentioned above may be upset under field operating conditions.
Another prior art technique provided a delay line comprising a silicon substrate having a sapphire spiral precisely etched thereon (termed a "stripline" in the art). Computer control techniques were used to carefully control the etching process to yield a spiral having precise time delay and impedance characteristics. Such etched spirals may in practice only be adjusted by shortening the spiral length (wire jumpers are used for this purpose) which, in turn, varies the spiral time delay. This technique does not, however, enable independent adjustment of phase or time delay characteristics within a range of frequencies--which may be accomplished with the present invention. Furthermore, the time delay and impedance matching characteristics of such spiral elements are subject to change with temperature which is undesirable as mentioned above.
An object of the present invention is to provide a tuneable electronic delay line for a feedforward amplifier. The delay line may be installed in a feedforward amplifier and then adjusted to vary either its time delay or impedance matching characteristics, or both, as may be required to suit the operating requirements of the individual amplifier circuit with which the delay line is to function.
A related object is to provide a delay line for a feedforward amplifier which may be easily mass produced and which may be easily adjusted under volume production conditions.
SUMMARY OF THE INVENTION
In a preferred embodiment, the invention is directed to a tuneable electronic delay line for delaying signals passing between first and second end points. The delay line comprises a plurality of inductance coils connected in series between said first and second end points; a shunt capacitor connected between each connected inductance coil pair and electrical ground; a variable capacitor connected between the first end point and electrical ground; and, a reactive element connected between the second end point and electrical ground. Preferably, the reactive element comprises a short wire coil.
Advantageously, the coils and capacitors are closely confined within a metal enclosure. The enclosure includes a removable lid having a plurality of apertures for enabling access to the coils, the variable capacitor and the reactive element for tuning said delay line. The enclosure further includes a thermally and electrically conductive strap for connecting the enclosure to electrical ground and for conducting heat to the enclosure.
SUMMARY OF THE DRAWINGS
FIG. 1 is a block diagram of an ideal feedforward amplifier.
FIG. 2 is a block/schematic diagram of a feedforward amplifier having a delay line in accordance with the preferred embodiment of the invention.
FIG. 3A is a fragmented pictorial view (on an enlarged scale) of a delay line in accordance with the preferred embodiment of the invention.
FIG. 3B shows the connection side of a printed circuit board for mounting the delay line of FIG. 3A and for connecting it to a feedforward amplifier.
FIG. 4 is a pictorial representation of the circuit components of a feedforward amplifier, including a fragmented pictorial representation of a delay line in accordance with the preferred embodiment of the invention.
FIG. 5A is a graph showing degree of input loop cancellation ideally observed after tuning second delay means 22 as hereinafter described; first delay means 18 having been terminated to match the transmission line impedance. In FIG. 5A, signal attenuation in decibels relative to a reference line of "0" is plotted as the ordinate, and frequency in MHz is plotted as the abscissa.
FIG. 5B is a graph showing the input return loss ideally observed after tuning second delay means 22 as hereinafter described; first delay means 18 having been terminated to match the transmission line impedance. In FIG. 5B, power loss ("return loss") in decibels relative to an ideal impedance match represented by a reference line of "0" is plotted as the ordinate, and frequency in MHz is plotted as the abscissa.
FIG. 6A is a graph showing degree of output loop cancellation ideally observed after tuning first delay means 18 as hereinafter described; second delay means 22 having been terminated to match the transmission line impedance. In FIG. 6A, signal attenuation in decibels relative to a reference line of "0" is plotted as the ordinate, and frequency in MHz is plotted as the abscissa.
FIG. 6B is a graph showing the output return loss ideally observed after tuning first delay means 18 as hereinafter described; second delay means 22 having been terminated to match the transmission line impedance. In FIG. 6B, power loss ("return loss") in decibels relative to an ideal impedance match represented by a reference line of "0" is plotted as the ordinate, and frequency in MHz is plotted as the abscissa.
FIG. 7 is a block diagram representation of a test instrument setup for tuning the feedforward amplifier delay lines as hereinafter described.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The basic principles of operation of an ideal feedforward amplifier are first described with reference to FIG. 1 to provide those skilled in the art with a framework for understanding the invention.
FIG. 1 is a block diagram of an ideal (lossless) feedforward amplifier which includes a main amplifier 10 and an error amplifier 12. An RF signal "V" which is to be amplified is coupled from cable 14 to first directional coupler 16 which splits the signal into two portions, one of which is delivered to the input terminal of main amplifier 10 and the other of which is delivered to first delay means 18. The amplified signal appearing at the output terminal of main amplifier 10 has the form "VG+V d ", where "G" represents the gain of main amplifier 10 and "V d " represents the signal distortion inherently introduced by the amplification process. Ideally, the distortion component V d is to be eliminated to yield a "pure" amplified signal "VG".
The amplified signal "VG+V d ", which is 180° out of phase with respect to the input signal V, is coupled to second directional coupler 20 which splits the amplified signal into two portions, one of which is directed to second delay means 22 and the other of which is directed to attenuator 24. Attenuator 24 is adjusted to attenuate signals passing therethrough by an amount which is inversely proportional to the gain "G" of main amplifier 10. Accordingly, the signal appearing at the output terminal of attenuator 24 has the form "V+V d /G". This attenuated signal portion is coupled to third directional coupler 26 which combines it with the non-amplified signal portion passed through first delay means 18.
First delay means 18 is included to ensure that the non-amplified signal portion reaching third directional coupler 26 will coincide precisely in time with the attenuated signal portion passed to third directional coupler 26 by attenuator 24. If these signals do not coincide precisely in time then undesireable distortion results when they are combined.
Because the attenuated signal portion is 180° out of phase with respect to the non-amplified signal portion, signals in the two portions representative of the input signal "V" cancel one another, so that the signal leaving third directional coupler 26 has the form "V d /G".
Ideally, and to simplify the background discussion, the gain of error amplifier 12 is equal to the gain "G" of main amplifier 10. Thus, a signal representative of the distortion component "V d " introduced by main amplifier 10 appears at the output terminal of error amplifier 12.
Second delay means 22 delays the amplified signal "VG+V d " before presenting it to fourth directional coupler 28 so that it coincides precisely in time with the error amplifer output signal, which is also presented to fourth directional coupler 28. The signal "V d " appearing at the output of error amplifier 12 is 180° out of phase with respect to the signal leaving second delay means 22. Accordingly, when the error amplifier output signal is combined by fourth directional coupler 28 with the output signal from second delay means 22, signal components representative of the distortion "V d " introduced by main amplifier 10 precisely cancel one another, leaving a "pure" amplified signal "VG" for passage along cable 14.
First and second delay means 18 and 22 must be carefully designed to meet two objectives. First, each delay means must delay signals passing therethrough for a precise time interval so that separate signals reaching either of combining couplers 26 or 28 coincide precisely in time. Otherwise, undesirable distortion results. Second, each of first and second delay means 18 and 22 must be carefully impedance matched with the other amplifier circuit components to avoid undesirable signal attenuation caused by impedance mis-matching.
According to the invention, delay means 18 and 22 may each comprise a lumped LC circuit. Conventional circuit design principles suggest that a lumped LC circuit would be incompatible with the two objectives of precise time delay and impedance matching. For example, a lumped LC circuit which has been "tuned" to provide a given time delay would have a fixed impedance which, in all probability, would be seriously mismatched to the characteristic impedance of the amplifier circuit, thus defeating the objective of precise impedance matching. Conversely, a lumped LC circuit having the correct impedance would most likely not yield an appropriate time delay, thus defeating the other objective. Furthermore, signals passing through a lumped LC circuit are delayed in some frequency bands for time periods which are different than the time delay periods in other frequency bands. If attempts are made to "tune" lumped LC circuit, the signal time delay varies between different frequency bands, and, as mentioned above, the circuit impedance changes. However, the inventor has found that; notwithstanding these suggested difficulties, tuneable electronic delay lines comprising lumped LC circuits having time delay and impedance matching properties which are ideally suited to feedforward amplifier applications may be constructed in accordance with the invention.
FIG. 3A is a fragmented pictorial illustration of a tuneable electronic delay line constructed in accordance with the preferred embodiment of the invention. The preferred embodiment hereinafter described is a delay line for a feedforward amplifier operating in the 50 MHz-400 MHz range. The delay line provides a group delay over this frequency range of approximately 4 nanoseconds. Eight inductance coils 30a through 30h are connected in series between first and second delay line end points represented by the central terminals of conventional 75 ohm coaxial cable connectors 32a and 32b. Inductance coils 30a through 30h each comprise three turns of 26 AWG enamel wire. The coils have a diameter of 0.144 inches. Seven shunt capacitors 34a through 34g are connected between each connected inductance coil pair and electrical ground. Shunt capacitors 34a through 34g are each 5.6 pf N.P.O. chip capacitors. Such capacitors are manufactured without protruding wire leads which may introduce undesirable inductances. Furthermore, their capacitance remains substantially unaffected by temperature changes.
The exact number of inductance coils and shunt capacitors may vary with the feedforward amplifier frequency range. As explained above, a lumped LC circuit delays signals in different frequency bands for different time periods. A plurality of inductance coils and shunt capacitors affords a means for adjusting the time delay in different frequency bands and for adjusting the amplifier impedance matching characteristics as hereinafter explained in greater detail. However, the total number of inductance coils and shunt capacitors is, to some extent, dictated by the feedforward amplifier frequency range. For example, it has been found that nine inductance coils and eight shunt capacitors are required to provide adequate time delay in feedforward amplifiers which operate in the 50 MHz-350 MHz frequency range. If the amplifier frequency range is increased to 50 MHz-400 MHz then eight inductance coils and seven shunt capacitors have been found to suffice; whereas seven inductance coils and six shunt capacitors suffice if the amplifier frequency range is further increased to 50 MHz-450 MHz. In each case, the basic layout illustrated in FIG. 3A may be adapted to the desired frequency range of operation by adding or removing inductance coil/shunt capacitor pairs, from the end of the delay line which is closest to coaxial cable connector 32b.
Variable capacitor 36 is connected between the first delay line end point represented by connector 32a and electrical ground. Variable capacitor 36 is a 1-3 pf ceramic N.P.O. One end of a reactive element such as a short coil of wire 44 is connected to the second delay line end point comprising the central terminal of connector 32b. The other end of wire 44 is not connected to anything. Wire 44 provides a small amount of capacitance and inductance relative to electrical ground, which assists in tuning the delay line as hereinafter described.
Inductance coils 30a through 30h, shunt capacitors 34a through 34g, connectors 32a and 32b, variable capacitor 36 and wire coil 44 are mounted on a delay line printed circuit board as is shown in FIG. 3B. Inductance coil 30a is connected between pads 38 and 40a of the printed circuit board. Inductance coils 30b through 30g are connected, respectively, between pad pairs 40a-40b through 40f-40g. Inductance coil 30h is connected between pads 40g and 42. The central terminal of 75 ohm coaxial cable connector 32a is connected to pad 38 and its outer terminals protrude through holes in the ground plane 43 etched around the outer periphery of the circuit board and are connected to the ground plane. 75 ohm coaxial cable connector 32b is connected at the opposite end of the circuit board in similar fashion with its central terminal protruding through and connected to pad 42. Variable capacitor 36 is connected between pad 38 and the circuit board ground plane 43. Wire coil 44 is connected to the central terminal of cable connector 32b at pad 42.
Referring again to FIG. 3A, sheet metal enclosure 46 contains the delay line printed circuit board and closely confines inductance coils 30a through 30h, shunt capacitors 34a through 34g, variable capacitor 36 and wire coil 44. Enclosure 46 is provided with a removable metal lid 48 which has a plurality of apertures 50a through 50e through which the delay line may be tuned as hereinafter described. Metal enclosure 46 and lid 48 have an inherent capacitance relative to the electrical ground potential of the amplifier which serves to shield the delay line circuit components somewhat from the effects of interfering electrical signals produced outside enclosure 46. When the delay line has been tuned as hereinafter described a piece of copper tape is affixed over apertures 50a through 50e to close those apertures and seal the delay line.
FIG. 2 is a block/schematic diagram of a feedforward amplifier for amplifying signals in the 50 MHz-400 MHz band and having delay lines in accordance with the preferred embodiment. In FIG. 2, amplifier components described above with reference to FIG. 1 bear the same reference numerals as appear in FIG. 1. Parallel connected resistor/capacitor pairs are coupled to each of directional couplers 16, 20, 26 and 28 to provide directivity for the couplers in well known fashion. As hereinafter described, variable capacitors C x and C y enable adjustment of the amplifier return loss prior to commencement of the delay line tuning procedure. Delay lines 18 and 22 are represented schematically in FIG. 2 with conventional electrical symbols. In FIG. 2, wire coil 44 included in each of delay lines 18 and 22 is represented as a variable shunt capacitor having a broken arrow therethrough. Note that the end point of delay line 18 to which variable shunt capacitor 36 is connected is coupled to directional coupler 26. The end point of delay line 22 to which variable shunt capacitor 36 is connected is coupled to directional coupler 20.
As shown in FIG. 2, attenuator 24 includes a "T" resistance pad having a variable resistor 19 for adjusting the amount by which signals passing from second directional coupler 20 to third directional coupler 26 are attenuated. Variable capacitors 21 and 23 included in attenuator 24 are used to adjust the amplifier frequency response as hereinafter explained. In practice, variable capacitors 21 and 23 comprise small wire coils connected across resistor 19.
Also shown in FIG. 2 are amplitude modulators 50 and 52 which are included to assist in testing of the feedforward amplifier balance check modulation. Amplitude modulators 50 and 52 include, respectively, PNP transistors 54 and 56 which are shunted, respectively, by zener diodes 58 and 60.
FIG. 4 is a pictorial representation of a feedforward amplifier having two delay lines in accordance with the preferred embodiment. FIG. 4 illustrates the manner in which first and second delay means 18 and 22 may respectively be plugged, by means of 75 ohm connector pairs 31a-31b and 32a-32b into mating coaxial cable connector pairs on the amplifier circuit board. FIG. 4 also illustrates the provision of straps 66 which are rigidly affixed to sheet metal enclosures 46 to provide good thermal and electrical conductivity therewith. When first and second delay means 18 and 22 are installed as shown in FIG. 4, straps 66 press firmly against ground posts 68, thereby connecting enclosures 46 to electrical ground. Ground posts 68 protrude through the feedforward amplifier circuit board and are rigidly affixed to heat sinks on the opposite side thereof (not shown). A separate heat sink is provided for each of main amplifier 10 and error amplifier 12. The heat sinks dissipate heat generated by main amplifier 10 and error amplifier 12. Accordingly, ground posts 68 are heated and conduct heat via thermally conductive straps 66 to enclosures 46. Enclosures 46 and the delay line circuit components therein are thus maintained at a relatively constant temperature when the feedforward amplifier is in operation, which minimizes temperature induced changes in the time delay or impedance characteristics of the delay lines.
Preferably, main amplifier 10 and error amplifier 12 are pre-selected in "matched" pairs such that the gain of either amplifier in the pair does not deviate with respect to the gain of the other amplifier by more than 0.25 dB at any frequency between 50 MHz and 400 MHz. If the amplifiers are not matched in this fashion then it would be necessary to include a variable resistor in the feedforward amplifier circuit to compensate for variations in gain between the main and error amplifiers. This is undesirable because the impedance matching characteristics of the overall feedforward amplifier circuit may be upset by the inclusion of such a variable resistor. The foregoing criteria for "matched" amplifier pairs is not unduly restrictive. It has been found, for example, that a random sample of 100 integrated circuit amplifiers such as Motorola MHW4342 or 5342 will yield about 40 matched pairs which satisfy the foregoing criteria.
A feedforward amplifier having delay lines in accordance with the invention is tuned by adjusting the delay lines to provide the proper time delay and impedance matching characteristics so that the amplifier will function as closely as possible in accordance with the theoretical description given above.
FIG. 7 illustrates a test instrument setup for tuning the feedforward amplifier previously described. The tuning procedure is as follows:
1. Sweep generator 70 is used to inject a sweep signal of 40-500 MHz bandwidth into third directional coupler 26. The amplified signal appearing at the output of error amplifier 12 is applied to the input terminal of a 10 dB directional coupler 84.
2. Alternate sweep generator 72 is used to inject a second sweep signal having a 40 MHz-500 MHz bandwidth into the output terminal of directional coupler 84. Directional coupler 84 combines the signals originating from sweep generators 70 and 72. Sweep generators 70 and 72 must be alternately triggered by means of a suitable alternate sweep generator trigger 74 so that the sweep signals do not interfere with one another.
3. First return loss bridge 85 is coupled between sweep generator 70 and the input of the amplifier under test to provide, on display 86, an indication of input return loss (FIG. 6B) of the amplifier under test. Second return loss bridge 76 is coupled between alternate sweep generator 72 and the output terminal of directional coupler 84 to provide, on display 78, an indication of output return loss (FIG. 5B) of the amplifier under test.
4. Response detector 80 is tapped to directional coupler 84 to provide, on display 82, an indication of the degree of loop cancellation (FIGS. 5A and 6A) of the amplifier under test.
5. A matched pair of integrated circuit amplifiers are inserted into the feedforward amplifier circuit.
6. First and second delay means 18 and 22 are removed and replaced with 75 ohm terminators.
7. Variable capacitors C x and C y are adjusted to minimize return loss of the amplifier under test. This return loss must be adjusted to greater than minus 20 dB (less than 10% reflection).
8. The 75 ohm terminator which replaced second delay means 22 is removed and second delay means 22 is inserted into the feedforward amplifier circuit. The 75 ohm terminator that replaced first delay means 18 is not removed.
9. Second delay means 22 is tuned by observing the degree of loop cancellation and return loss displayed, respectively, on displays 82 and 78 (FIGS. 5A and 5B respectively). Lid 48 is removed from second delay means 22. Tweezers and a needle point are used to carefully move each of inductance coils 30a through 30h and to simultaneously adjust variable resistor 19 of attenuator 24 so as to "deepen" the overall loop null pattern observed on display 82 (FIG. 5A). Concurrently, variable capacitor 36 is adjusted to minimize the return loss observed on display 78 (FIG. 5B). Simultaneous adjustment of capacitors 21 or 23 in attenuator 24 may affect the degree of loop cancellation observed on display 82, without affecting the return loss observed on display 78.
10. When the best possible loop cancellation and return loss patterns are observed on displays 82 and 78, lid 48 is replaced on second delay means 22. This should improve loop cancellation somewhat without affecting return loss.
11. Additional fine tuning may be accomplished by passing a needle point through any of apertures 50a through 50e in lid 48 to make minor adjustments to the position of any of inductance coils 30a through 30h.
12. Once the desired loop cancellation is obtained, variable resistor 19 and variable capacitors 21 and 23 in attenuator 24 are not further adjusted. A piece of copper tape is placed over apertures 50a through 50e of second delay means 22 to shield it from possible damage or mis-adjustment.
13. Second delay means 22 is removed and replaced with a 75 ohm terminator. The 75 ohm terminator which replaced first delay means 18 is then removed and first delay means 18 is plugged into the circuit.
14. First delay means 18 is tuned by repeating steps 9 through 11 above to obtain the best possible loop cancellation and return loss for main amplifier 10 (FIGS. 6A and 6B). First delay means 18 is then sealed with copper tape to protect it from damage or mis-adjustment.
15. Second delay means 22 is reinstalled in the feedforward amplifier circuit and 10 dB directional coupler 84 is removed.
16. The amplifier frequency response is determined by sweeping it with a signal of 1 dB resolution. The amplifier frequency response should vary by no more than about 35 0.2 dB from 40 MHz through 410 MHz.
17. Final balance of the amplifier is achieved by observing the degree of cross-modulation present over the 40 MHz-400 MHz bandwidth. Small changes in balance may be corrected by adjusting resistor 19 in attenuator 24 or by adjusting wire coil 23 which represents a variable shunt capacitor connected across resistor 19. Resistor 19 varies balance over the entire frequency range whereas wire coil 23 affects only high frequency balance.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. | A tuneable lumped LC electronic delay line for delaying RF signals in a bandwidth of at least 100 MHz by a substantially constant amount throughout the band, the delay line including a plurality of deformable air coil inductors that are inductively coupled to one another, a plurality of capacitors connected between each inductor pair and electrical ground, and a reactive element connected at one end of the series of inductors and reactively coupled to electrical ground. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to information handling systems and more particularly to Ethernet switching of PCI Express Packets.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
It is known to provide information handling systems which conform to a Peripheral Component Interconnect (PCI) Express (PCIe) architecture. The PCIe architecture is a high-speed, serial, frame-based interconnect architecture. It is known to provide a PCIe information handling system with virtualization functionality. Virtualization provides a technique for hiding physical characteristics of computing resources from the way in which other systems, applications, or end users interact with those resources. The PCIe specification defines a plurality of virtualization constructs. These virtualization constructs include Single Root I/O Virtualization (SR-IOV) and Multi Root I/O Virtualization (MR-IOV). The PCIe specification also defines a switching architecture to provide virtualization support with system architectures that interconnect multiple PCIe root complexes to PCIe input/output (I/O) adapters. This virtualization support is accomplished using a frame-based PCIe protocol.
There are a number of issues relating to PCIe switching. These issues include scalability, maturity and a relatively limited number of vendors implementing these devices. Additionally, the PCIe architecture is also a local switching architecture that is unable to scale or reach beyond localized servers. Thus the PCIe architecture is not well suited to a blade system type environment.
It is also known to provide large scale information handling systems, such as blade type systems which conform to an Ethernet architecture. Ethernet is a family of frame-based computer networking technologies for local area networks (LANs). The Ethernet architecture defines wiring and signaling standards for a physical layer, through means of network access at the Media Access Control (MAC) and Data Link Layer (DDL), as well as a common addressing format. Ethernet switching is a mature architecture and a very large vendor ecosystem supports the architecture.
It would be desirable to provide a system and method to encapsulate PCIe packets within Ethernet packets and thus emulate PCIe behavior over the Ethernet switching fabric.
SUMMARY OF THE INVENTION
In accordance with the present invention a system and method are provided which encapsulate PCIe packets within Ethernet packets and thus emulate PCIe behavior over the Ethernet switching fabric.
More specifically, in one embodiment, the invention relates to a method for emulating Peripheral Component Interconnect Express (PCIe) behavior over an Ethernet switching fabric which includes encapsulating a PCIe packet within an Ethernet packet to provide an Ethernet encapsulated PCIe packet, and routing the Ethernet encapsulated PCIe packet within the Ethernet switching fabric via information included within the Ethernet packet.
In another embodiment, the invention relates to an apparatus for emulating Peripheral Component Interconnect Express (PCIe) behavior over an Ethernet switching fabric which includes means for encapsulating a PCIe packet within an Ethernet packet to provide an Ethernet encapsulated PCIe packet, and means for routing the Ethernet encapsulated PCIe packet within the Ethernet switching fabric via information included within the Ethernet packet.
In another embodiment, the invention relates to an information handling system which includes a processor and memory coupled to the processor. The memory stores a system for emulating Peripheral Component Interconnect Express (PCIe) behavior over an Ethernet switching fabric. The system for emulating Peripheral Component Interconnect Express (PCIe) behavior over an Ethernet switching fabric includes instructions executable by the processor for encapsulating a PCIe packet within an Ethernet packet to provide an Ethernet encapsulated PCIe packet, and routing the Ethernet encapsulated PCIe packet within the Ethernet switching fabric via information included within the Ethernet packet.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element.
FIG. 1 shows a system block diagram of an information handling system.
FIG. 2 shows a block diagram of an Open Systems Interconnection layer model and PCIe protocol.
FIG. 3 shows a block diagram of an encapsulation of a PCIe TLD/DLLP PDUs in an Ethernel Layer 2 frame.
FIG. 4 shows a block diagram of mapping of user priorities to PCIe TCs.
FIG. 5 shows a block diagram of mapping of VLANs to VCs.
FIG. 6 shows a block diagram of PCIe address to Ethernet MAC translation.
DETAILED DESCRIPTION
Referring briefly to FIG. 1 , a system block diagram of an information handling system 100 is shown. The information handling system 100 includes a processor 102 , input/output (I/O) devices 104 , such as a display, a keyboard, a mouse, and associated controllers, memory 106 , including volatile memory such as random access memory (RAM) and non-volatile memory such as read only memory (ROM) and hard disk drives, and other storage devices 108 , such as a floppy disk and drive or CD-ROM disk and drive, and various other subsystems 110 , all interconnected via one or more buses 112 . The memory 106 includes a basic input output system 128 as well as a PCIe transport module 130 .
The a PCIe transport system 130 enables the information handling system 100 to transport PCIe packets over an Ethernet switching fabric thereby emulating the facilities provided by a PCIe switching infrastructure.
For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components.
FIG. 2 shows a block diagram of an interrelation 210 (or lack thereof) between an Open Systems Interconnection (OSI) layer model 210 and PCIe protocol 212 is shown. FIG. 3 shows a block diagram of an encapsulation of a PCIe TLD/DLLP protocol data unit (PDU) 310 within an Ethernet frame 320 such as an Ethernet Layer 2 frame.
The PCIe protocol model 212 does not precisely correspond to the OSI layer model 210 . More specifically, the PCIe Transport Layer Protocol (TLP) and the PCIe Data Link-Layer Protocol (DLLP) being mutually aware of each other and not strictly layered with regard to responsibilities presents a challenge when encapsulating the PCIe protocol.
Referring to FIG. 4 , a block diagram of mapping of user priorities to PCIe traffic classes (TCs) is shown. There are facilities defined within the PCIe protocol to support Quality of Service (QoS) and virtual pathways. These facilities are referred to as Traffic Class (TC) facilities 410 and Virtual Channel (VC) facilities, respectively.
PCIe packets are routed either by address or by device/bus/function identifier. To move PCIe packets through a non-PCIe switching fabric, the transport system 130 should emulate the TC facilities, the VC facilities and the routing methods inherent in the PCIe definition. While the transport system 130 does not necessarily achieve exact correspondence, the system 130 should not adversely affect the expected behavior of the switching infrastructure.
Thus, to enable Ethernet as an underlying fabric for PCIe packet transport the transport system 130 maps TC and VC behavior and translates Ethernet MAC forwarding techniques to PCIe routing techniques. More specifically, the PCIe architecture defines eight levels of differentiated TC service with TC 0 being a best effort and TC 1 -TC 7 offering differentiated service levels. Additionally, Ethernet, such as Ethernet 802.1Q (802.1p historical sections), defines eight user priority levels. Accordingly, to enable Ethernet as an underlying fabric for a PCIe packet, the transport system 130 maps the TC levels of the PCIe architecture to the Ethernet user priority levels.
Referring to FIG. 5 , a block diagram of mapping of virtual local area networks (VLANs) to VCs is shown. More specifically, PCIe VCs 510 are artifacts that support a TC differentiated service facility. Each VC can have one or more TCs mapped to it. Thus, VCs provide an internal arbitrated buffering scheme that implement the TC capability by the placement of packets with different TC values into the appropriate VC buffers. There can be up to eight VCs in a PCIe infrastructure. VCs closely resemble Ethernet VLANs 520 , particularly VLANs that are priority based. VLANs, unlike VCs, are steered directly through the Ethernet switching fabric. Buffers in an Ethernet switch support the 802.1Q/p priority levels directly. VCs can thus be mapped to VLANs via the transport system 130 .
Referring to FIG. 6 , a block diagram of PCIe address to Ethernet MAC translation is shown. To route PCIe packets the transport system 130 associates MAC addresses with the PCIe address ranges supported by specific adapters. This is accomplished via a translation table 610 .
While the re-transmit facility of the PCIe DLLP layer is not possible using only Ethernet Layer 2 protocols, the corruption of an Ethernet Layer 2 packet is a rare event and can be handled by the upper layers of the Ethernet such as the Transmission Control Protocol (TCP). Additionally, the possibility of out-of-order packets is substantially eliminated within PCIe transport system 130 by using sequence numbers. While this function is not available within an Ethernet Layer 2 switch 630 , this function can be provided by the IP (Internet Protocol) layer. These events arc rare, especially in an internal fabric with dedicated lanes.
The present invention is well adapted to attain the advantages mentioned as well as others inherent therein. While the present invention has been depicted, described, and is defined by reference to particular embodiments of the invention, such references do not imply a limitation on the invention, and no such limitation is to be inferred. The invention is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent arts. The depicted and described embodiments are examples only, and are not exhaustive of the scope of the invention.
For example, the above-discussed embodiments include software modules that perform certain tasks. The software modules discussed herein may include script, batch, or other executable files. The software modules may be stored on a machine-readable or computer-readable storage medium such as a disk drive. Storage devices used for storing software modules in accordance with an embodiment of the invention may be magnetic floppy disks, hard disks, or optical discs such as CD-ROMs or CD-Rs, for example. A storage device used for storing firmware or hardware modules in accordance with an embodiment of the invention may also include a semiconductor-based memory, which may be permanently, removably or remotely coupled to a microprocessor/memory system. Thus, the modules may be stored within a computer system memory to configure the computer system to perform the functions of the module. Other new and various types of computer-readable storage media may be used to store the modules discussed herein. Additionally, those skilled in the art will recognize that the separation of functionality into modules is for illustrative purposes. Alternative embodiments may merge the functionality of multiple modules into a single module or may impose an alternate decomposition of functionality of modules. For example, a software module for calling sub-modules may be decomposed so that each sub-module performs its function and passes control directly to another sub-module.
Consequently, the invention is intended to be limited only by the spirit and scope of the appended claims, giving full cognizance to equivalents in all respects. | A method for emulating Peripheral Component Interconnect Express (PCIe) behavior over an Ethernet switching fabric which includes encapsulating a PCIe packet within an Ethernet packet to provide an Ethernet encapsulated PCIe packet, and routing the Ethernet encapsulated PCIe packet within the Ethernet switching fabric via information included within the Ethernet packet. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for driving a display device including the steps of providing a digital value as video level for each pixel or cell of a line of the display device, providing at least one reference driving signal and generating a driving signal on the basis of the digital value and the at least one reference driving signal. Furthermore, the present invention relates to a respective apparatus for driving a display device.
BACKGROUND OF THE INVENTION
[0002] The structure of an active matrix OLED (organic light emitting display) or AMOLED is well known. According to FIG. 1 it comprises:
an active matrix 1 containing, for each cell (one pixel includes a red cell, a green cell and a blue cell), an association of several TFTs T 1 , T 2 with a capacitor C connected to an OLED material. Above the TFTs the capacitor C acts as a memory component that stores a value during a part of the video frame, this value being representative of a video information to be displayed by the cell 2 during the next video frame or the next part of the video frame. The TFTs act as switches enabling the selection of the cell 2 , the storage of a data in the capacitor C and the displaying by the cell 2 of a video information corresponding to the stored data; a row or gate driver 3 that selects line by line the cells 2 of the matrix 1 in order to refresh their content; a column or source driver 4 that delivers the data to be stored in each cell 2 of the current selected line; this component receives the video information for each cell 2 ; and a digital processing unit 5 that applies required video and signal processing steps and that delivers the required control signals to the row and column drivers 3 , 4 .
[0007] Actually, there are two ways for driving the OLED cells 2 . In a first way, each digital video information sent by the digital processing unit 5 is converted by the column drivers 4 into a current whose amplitude is directly proportional to the video level. This current is provided to the appropriate cell 2 of the matrix 1 . In a second way, the digital video information sent by the digital processing unit 5 is converted by the column drivers 4 into a voltage whose amplitude is proportional to the square of the video level. This current or voltage is provided to the appropriate cell 2 of the matrix 1 .
[0008] However, in principle, an OLED is current driven so that each voltage based driven system is based on a voltage to current converter to achieve appropriate cell lighting.
[0009] From the above, it can be deduced that the row driver 3 has a quite simple function since it only has to apply a selection line by line. It is more or less a shift register. The column driver 4 represents the real active part and can be considered as a high level digital to analog converter.
[0010] The displaying of a video information with such a structure of AMOLED is symbolized in FIG. 2 . The input signal is forwarded to the digital processing unit that delivers, after internal processing, a timing signal for row selection to the row driver synchronized with the data sent to the column driver 4 . The data transmitted to the column driver 4 are either parallel or serial. Additionally, the column driver 4 disposes of a reference signalling delivered by a separate reference signalling device 6 . This component 6 delivers a set of reference voltages in case of voltage driven circuitry or a set of reference currents in case of current driven circuitry. The highest reference is used for the white and the lowest for the smallest gray level. Then, the column driver 4 applies to the matrix cells 2 the voltage or current amplitude corresponding to the data to be displayed by the cells 2 .
[0011] In order to illustrate this concept, the example of a voltage driven circuitry will be taken in the rest of this document. The driver of this example uses 8 reference voltages named V 0 to V 7 and the video levels are built as explained in the following table 1.
TABLE 1 Gray level table from voltage driver Video level Grayscale voltage level 0 V7 1 V7 + (V6 − V7) × 9/1175 2 V7 + (V6 − V7) × 32/1175 3 V7 + (V6 − V7) × 76/1175 4 V7 + (V6 − V7) × 141/1175 5 V7 + (V6 − V7) × 224/1175 6 V7 + (V6 − V7) × 321/1175 7 V7 + (V6 − V7) × 425/1175 8 V7 + (V6 − V7) × 529/1175 9 V7 + (V6 − V7) × 630/1175 10 V7 + (V6 − V7) × 727/1175 11 V7 + (V6 − V7) × 820/1175 12 V7 + (V6 − V7) × 910/1175 13 V7 + (V6 − V7) × 998/1175 14 V7 + (V6 − V7) × 1086/1175 15 V6 16 V6 + (V5 − V6) × 89/1097 17 V6 + (V5 − V6) × 173/1097 18 V6 + (V5 − V6) × 250/1097 19 V6 + (V5 − V6) × 320/1097 20 V6 + (V5 − V6) × 386/1097 21 V6 + (V5 − V6) × 451/1097 22 V6 + (V5 − V6) × 517/1097 . . . . . . V1 + (V0 − V1) × 2278/3029 251 V1 + (V0 − V1) × 2411/3029 252 V1 + (V0 − V1) × 2549/3029 253 V1 + (V0 − V1) × 2694/3029 254 V1 + (V0 − V1) × 2851/3029 255 V0
[0012] Table 1 illustrates the obtained output voltages (gray scale voltage levels) from the voltage driver for various input video levels. For instance, the reference voltages of Table 2 are used.
TABLE 2 Example of voltage references Reference Vn Voltage (V) V0 3 V1 2.6 V2 2.2 V3 1.4 V4 0.6 V5 0.3 V6 0.16 V7 0
[0013] Then, the grayscale voltage levels of following Table 3 depending on video input levels according to Table 1 and Table 2 are obtained:
TABLE 3 Example of gray level voltages Video level Grayscale voltage level 0 0.00 V 1 0.001 V 2 0.005 V 3 0.011 V 4 0.02 V 5 0.032 V 6 0.045 V 7 0.06 V 8 0.074 V 9 0.089 V 10 0.102 V 11 0.115 V 12 0.128 V 13 0.14 V 14 0.153 V 15 0.165 V 16 0.176 V 17 0.187 V 18 0.196 V 19 0.205 V 20 0.213 V 21 0.221 V 22 0.229 V . . . . . . 250 2.901 V 251 2.919 V 252 2.937 V 253 2.956 V 254 2.977 V 255 3.00 V
[0014] As can be seen in the previous paragraph current AMOLED concepts are capable of delivering 8-bit gradation per color. This can be further enhanced by using more advanced solutions like improvements on analog sub-fields.
[0015] In any case, there will be the need in the future of displays having more video-depth. This trend can be seen in the development of transmission standards based on 10-bit color channels. At the same time, various display manufacturers like PDP makers are claiming providing displays with more than 10-bit color-depth.
SUMMARY OF THE INVENTION
[0016] The object of the present invention is to provide a method and an apparatus capable of increasing the video depth depending on the video content of each line in order to provide a maximum of color gradation for a given scene. I.e., a line content picture enhancement shall be provided.
[0017] According to the present invention this object is solved by a method for driving a display device including the steps of
providing a digital value as video level for each pixel or cell of a line of said display device, providing at least one reference driving signal and generating a driving signal on the basis of said digital value and said at least one reference driving signal, as well as adjusting said video level and said at least one reference driving signal in dependence of the digital values of at least a part of said line.
[0022] Furthermore, there is provided an apparatus for driving a display device including
input means for receiving a digital value for each pixel or cell of a line of said display device, reference signalling means for providing at least one reference driving signal and driving means for generating a driving signal on the basis of said digital value and said at least one reference driving signal, as well as adjusting means for adjusting said video level and said at least one reference driving signal in dependence of the digital values of at least a part of said line.
[0027] Preferably, the display device is an AMOLED or a LCD. Especially, these display concepts can be improved by the above described method or apparatus.
[0028] The reference driving signal may be a reference voltage or a reference current. Each of these driving systems can profit from the present invention.
[0029] According to a further preferred embodiment, a maximum digital value of at least the part of a line is determined and when adjusting the reference driving signals, they are assigned to digital values between a minimum digital value, which is to be determined or is predetermined, and a maximum digital value. By this way, the whole range of gray scale levels is used for the video input of one line.
[0030] A further improvement can be obtained when determining a histogram of the digital values of at least the part of a line and adjusting the reference driving signals on the basis of this histogram. This results in an enhanced picture line-dependent gradation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Exemplary embodiments of the invention are illustrated in the drawings showing in:
[0032] FIG. 1 a circuit diagram of an AMOLED electronic according to the prior art;
[0033] FIG. 2 a possible OLED display structure according to the prior art;
[0034] FIG. 3 a sequence of the movie “Zorro” and a corresponding line analysis diagram;
[0035] FIG. 4 a sequence of a Colombia movie and a corresponding line analysis diagram;
[0036] FIG. 5 a histogram of line 303 from the sequence “Zorro”;
[0037] FIG. 6 a histogram of line 303 with optimized reference voltages and
[0038] FIG. 7 a block diagram of a hardware embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0039] The main idea behind the inventive concept is based on the fact that in a video scene, the whole video dynamic range is not used on a large part of the scene. FIGS. 3 and 4 show typical examples for frames of different dynamics. FIG. 3 shows a dark picture of the movie “Zorro”. The picture has the format 4:3 with 561 lines. On the right hand side of FIG. 3 the maximum video level of each line is plotted.
[0040] FIG. 4 shows a picture of a Colombia film. The picture has the format 16:9 with 267 lines. The right hand side diagram of FIG. 4 illustrates that nearly each line is driven with a maximum video level.
[0041] Together, FIGS. 3 and 4 show that for some sequences there are strong differences in the vertical distribution of video levels. The most differences are located in dark scenes with some luminous content as illustrated by the sequence “Zorro”.
[0042] On the other hand, it is important to notice that in dark scenes the eye is much more sensitive to picture gradation. Therefore, an optimization of picture gradation for dark scenes while keeping luminous scenes quite stable would have a positive effect on the global picture quality.
[0043] As already explained, the main idea is to perform a picture line-dependent gradation by optimizing the driver reference signalling (voltage or current) to the maximum of video levels available in a line. For instance, in the sequence “Zorro” of FIG. 3 , the maximum video level for line 303 is 128 . Therefore, if nothing is done, from the 8-bit of available gradations ( 0 to 255 ), only 7 are used for this line ( 0 to 128 ). However, according to the present invention, the 8-bit gradation for video levels between 0 and 128 will be used. In order to do that, the reference signalling of the driver is adjusted to these 129 levels. In the present example of a voltage driven system the maximum voltage level will be adjusted to the 129 / 256 of the original one and all other voltages accordingly. This is illustrated in following Table 4:
TABLE 4 Example of adjusted voltage references for line 303 Reference Vn Line 303 Voltage (Vn) Original Voltage (Vrefn) V0 1.5 3 V1 1.3 2.6 V2 1.1 2.2 V3 0.7 1.4 V4 0.3 0.6 V5 0.15 0.3 V6 0.08 0.16 V7 0 0
[0044] More generally, a complex function can be applied to the reference signalling under the form S n =f(Sref n ;MAX(Line)) where MAX(Line) represents the maximum video level used for a given line and Srefn the reference signaling (either voltage or current). This function can be implemented by means of LUT or embedded mathematical functions.
[0045] In the example shown in Table 4, all voltages have been modified using the same transformation
V n = ( Vref n - Vref 7 ) ⨯ MAX ( Line ) 255 + Vref 7
where Vref 0 represents the threshold voltage. This is the simplest transformation that can be used for voltage driven system since the gamma function is applied inside the OLED according to the proportionality L(x,y)∝I(x;y)=k×(V(x;y)−V th ) 2 where L(x;y) represents the luminance of the pixel located at (x;y) and I(x,y) the current provided to this pixel. Indeed in a first approach, it is intended to have L(x,y)∝k×(Video(x;y)) 2 if one could afford to have a gamma of 2 instead of a gamma of 2.2. In this case it is easy to understand that if the Video level dynamic is modified by a factor p, then it is sufficient to modify the voltages by the same factor. In all other cases, like gamma different from 2 or current driven systems where no inherent gamma is existing a more complex transformation is mandatory for the voltage adjustment since the voltages are no more proportional to the video values.
[0046] For instance, in a current driven system there is L(x,y)=k×(I−I th ) but ideally it should be L(x,y)∝(Video(x;y)) 2.2 . Then, a gamma transfer function of 2.2 is needed between the video level and the applied intensity. So if the video level is divided by 2, the provided intensity must be divided by 4.59 since
L ( x , y ) ∝ ( Video ( x ; y ) 2 ) 2.2 = ( Video ( x ; y ) ) 2.2 2 2.2 .
[0047] The same is true for a voltage driven system and a real gamma of 2.2 is aimed. In this case, there is a transformation of 1.1 between video and voltages under the form V(x,y)∝Video(x;y) 1.1 that is needed in order to have finally:
L ( x,y )∝( V ( x;y )− V th ) 2 ∝(Video( x;y ) 1.1 ) 2 =Video( x;y ) 2.2
[0048] In that case, if the maximum video is divided by 2, the voltages must be divided by 2 1.1 =2.14.
[0049] Such a transformation is quite complex and it is often difficult to be computed on-chip. Therefore, the ideal solution is to use a LUT containing 255 inputs, each one dedicated to a maximum value. The output can be on 8-bit or more in order to define the adjusting factor. Ideally, 10-bit is mandatory.
[0050] Reverting to the example of the current driven system, if the maximum amplitude per line is 128, the output of the 256×10-bit LUT will be 225. Then the voltages will be multiplied by 225 and divided by 1024 to obtain the factor 4.59. Here, it is very difficult to perform a division in hardware excepted if a 2 m divider is used that is simply a shift register. Indeed, dividing by 1024 corresponds to a shift by 10. Therefore the multiplication coefficients are always based on a 2 p divider. Some further examples for such a LUT are given in Table 5 below.
TABLE 5 Example of LUT for reference signalling adjustment LUT (Voltage LUT (current driven) driven) MAX (Line) power of 1.1 power of 2.2 96 350 119 97 354 122 98 358 125 99 362 128 100 366 131 101 370 133 102 374 136 103 378 139 104 382 142 105 386 145 106 390 148 107 394 152 108 398 155 109 402 158 110 406 161 111 410 164 112 414 168 113 418 171 114 422 174 115 426 178 116 431 181 117 435 184 118 439 188 119 443 191 120 447 195 121 451 199 122 455 202 123 459 206 124 463 210 125 467 213 126 472 217 127 476 221 128 480 225 129 484 229 130 488 233 131 492 237 132 496 241 133 500 245 134 505 249 135 509 253 136 513 257 137 517 261 138 521 265
[0051] In parallel to that the video levels must be modified accordingly to benefit of the enhanced gradation. In that case
L out = L in ⨯ 255 MAX ( Line )
applies. Here also the transformation should be better implemented via a LUT with 256 inputs corresponding to the 256 possible values for MAX(Line) and an output corresponding to a coefficient on 10-bit or more.
[0052] In the previous paragraph, a simple solution is shown based on adjusting the reference signalling range to the maximal available video level in a line. A more advanced concept would lead in an optimization of the gradation between the more used video levels. Such enhanced concept of picture line-dependent gradation will be based on a histogram analysis performed on each line. The example of the sequence “Zorro” and the line 303 shall be taken from such histogram analysis with the previous approach for voltage adjustment.
[0053] FIG. 5 shows in a histogram analysis the repartition of video levels for the line 303 of the sequence “Zorro” ( FIG. 3 ). The vertical lines represent the new adjusted voltages from the first embodiment presented in connection with Table 4. The reference voltages are represented according to the example from Table 1 and the video level is adjusted according to the equation
V n = ( Vref n - Vref 0 ) ⨯ MAX ( Line ) 255 + Vref 0 .
[0054] Now, for all examples simply a gamma of 2 shall be used. For this case, the new correspondence between video levels and voltages is shown in Table 6.
TABLE 6 Adjusted gray level table from voltage driver Video level Grayscale voltage level 0 V7 0.5 V7 + (V6 − V7) × 9/1175 1 V7 + (V6 − V7) × 32/1175 1.5 V7 + (V6 − V7) × 76/1175 2 V7 + (V6 − V7) × 141/1175 2.5 V7 + (V6 − V7) × 224/1175 3 V7 + (V6 − V7) × 321/1175 3.5 V7 + (V6 − V7) × 425/1175 4 V7 + (V6 − V7) × 529/1175 4.5 V7 + (V6 − V7) × 630/1175 5 V7 + (V6 − V7) × 727/1175 5.5 V7 + (V6 − V7) × 820/1175 6 V7 + (V6 − V7) × 910/1175 6.5 V7 + (V6 − V7) × 998/1175 7 V7 + (V6 − V7) × 1086/1175 7.5 V6 8 V6 + (V5 − V6) × 89/1097 8.5 V6 + (V5 − V6) × 173/1097 9 V6 + (V5 − V6) × 250/1097 9.5 V6 + (V5 − V6) × 320/1097 10 V6 + (V5 − V6) × 386/1097 10.5 V6 + (V5 − V6) × 451/1097 11 V6 + (V5 − V6) × 517/1097 . . . . . . 125.5 V1 + (V0 − V1) × 2278/3029 126 V1 + (V0 − V1) × 2411/3029 126.5 V1 + (V0 − V1) × 2549/3029 127 V1 + (V0 − V1) × 2694/3029 127.5 V1 + (V0 − V1) × 2851/3029 128 V0
[0055] As it can be seen on FIG. 5 , the maximum of video levels are located between level 15 (V 5 ) and level 95 (V 2 ) but this is not the location where the finest gradation is obtained. However, the finest gradation is obtained when reference voltages are near together. This example shows that the gradation obtained with this driver with voltages computed according to the first embodiment is not optimized to this particular line structure.
[0056] Therefore, according to a further embodiment there is provided an adaptation of the video transformation and voltage levels to adjust finest gradation where the maximum of video levels are distributed. In order to implement this concept, a first table is needed representing the driver behavior, which means the number of levels represented by each voltage. This is illustrated in Table 7 for the example of Table 1. A full voltage reference table for the driver chosen as example is given in Annex 1.
TABLE 7 Example of voltage references video rendition Reference Vn Amount of levels V7 0 V6 15 V5 16 V4 32 V3 64 V2 64 V1 32 V0 32
[0057] It is generally known that a histogram of a picture represents, for each video level, the number of times this level is used. Such a histogram table is computed for a given line and described as HISTO[n], where n represents the possible video levels used for the input picture (at least 8 bit or more). In order to simplify the exposition, an input signal limited to 8-bit (256 discrete levels) will be taken.
[0058] Now, the main idea is based on a computation of video level limits for each voltage. Such a limit represents the ideal number of pixels that should be coded inside each voltage. Ideally, this will be based on a percentage of the number of pixels per line. For example, for a display with 720 pixels per lines (720×3 cells) the voltage V 5 should be used to encode at least 720×3×16/255=135 cells. Based on this assumption the following Table 8 is obtained.
TABLE 8 Example of voltage references limitation Amount of Limit with Reference Vn levels 320 cells V7 0 0 V6 15 127 V5 16 135 V4 32 271 V3 64 542 V2 64 542 V1 32 271 V0 32 271
[0059] The limits of this table are stored in an array LIMIT[k] with LIMIT[ 0 ]=0, LIMIT[ 1 ]=127, . . . , LIMIT[ 7 ]=271.
[0060] Now, for each line following exemplary computation is performed:
LevelCount = 0 Range = 1 For (l=0; l<255; l++) { LevelCount = LevelCount + HISTO[l] If (LevelCount > LIMIT[Range]) { LevelCount = 0 LEVEL_SELECT[Range]=l Range++ } }
[0061] From this computation a table of video levels LEVEL_SELECT[k] results that represents the video level at the transition between the voltage k- 1 and k. The results for line 303 are given in Table 9 below, which is based on Annex 2.
TABLE 9 Results of analysis for line 303 Level Occurrence Accumulation Decision 0 27 27 Range 1 1 13 40 Range 1 2 1 41 Range 1 3 2 43 Range 1 4 3 46 Range 1 5 4 50 Range 1 6 3 53 Range 1 7 0 53 Range 1 8 1 54 Range 1 9 1 55 Range 1 10 2 57 Range 1 11 0 57 Range 1 12 5 62 Range 1 13 7 69 Range 1 14 4 73 Range 1 15 8 81 Range 1 16 9 90 Range 1 17 19 109 Range 1 18 29 138 Range 2 19 50 188 Range 2 20 35 223 Range 2 21 37 260 Range 2 22 24 284 Range 3 23 26 310 Range 3 . . . . . . 116 0 2149 Range 7 117 2 2151 Range 7 118 1 2152 Range 7 119 0 2152 Range 7 120 1 2153 Range 7 121 0 2153 Range 7 122 0 2153 Range 7 123 2 2155 Range 7 124 0 2155 Range 7 125 1 2156 Range 7 126 1 2157 Range 7 127 2 2159 Range 7 128 1 2160 Range 7
[0062] Table 9 shows that:
Levels [ 0 - 17 ] are used in Range 1 →voltage V 6 →LEVEL_SELECT[ 1 ]=18 Levels [ 18 - 21 ] are used in Range 2 →voltage V 5 →LEVEL_SELECT[ 2 ]=22 Levels [ 22 - 31 ] are used in Range 3 →voltage V 4 →LEVEL_SELECT[ 3 ]=32 Levels [ 32 - 40 ] are used in Range 4 →voltage V 3 →LEVEL_SELECT[ 4 ]=41 Levels [ 41 - 51 ] are used in Range 5 →voltage V 2 →LEVEL_SELECT[ 5 ]=52 Levels [ 52 - 60 ] are used in Range 6 →voltage V 1 →LEVEL_SELECT[ 6 ]=61 Levels [ 61 - 128 ] are used in Range 7 →voltage V 0 →LEVEL_SELECT[ 7 ]=128
LEVEL_SELECT[ 0 ]=0.
[0070] The result is illustrated in FIG. 6 showing a possible optimization of the voltages repartition according to the video levels repartition. The example of algorithm used here for this optimization should be seen as an example since other computations with similar achievements are possible. Indeed, it could be better to reduce a bit more the gap V 1 to V 0 in the above example. This can be achieved by a more complicated system.
[0071] As soon as the optimal voltages repartition for a given line is defined, two types of adjustment should be performed to display a correct but improved picture:
First the adaptation of the voltages themselves—this computation is similar to the computation done in the previous embodiment. In that case the following equation applies:
V n = ( Vref n - Vrefr n - 1 ) ⨯ ( LEVEL_SELECT [ n ] - LEVEL_SELECT [ n - 1 ] LIMIT [ n ] ) + V n - 1
with n≧1 Then, the modification of the video levels to suit the new voltages distribution. In that case for a level located in Range n the luminance value is:
L out = ( L i n - LEVEL_SELECT [ n - 1 ] ) ⨯ ( LIMIT [ n ] LEVEL_SELECT [ n ] - LEVEL_SELECT [ n - 1 ] ) +
TRANS [ n - 1 ]
[0075] With the table transition being an accumulation of the LIMIT[k] values so that
TRANS [ k ] = ∑ p = 0 p = k LIMIT [ k ] .
Consequently, one gets TRANS[ 0 ]=0, TRANS[ 1 ]=16, TRANS[ 1 ]=32, TRANS[ 2 ]=64, TRANS[ 3 ]=128, TRANS[ 4 ]=192, TRANS[ 5 ]=224 and TRANS[ 6 ]=256.
[0076] The results of the previous computations are given in Tables 10 and 11 below:
TABLE 10 Computed new voltages for line 303 Vref Vline 303 V7 0.00 V 0.00 V V6 0.16 V 0.19 V V5 0.30 V 0.23 V V4 0.60 V 0.32 V V3 1.40 V 0.43 V V2 2.20 V 0.57 V V1 2.60 V 0.68 V V0 3.00 V 1.52 V
[0077]
TABLE 11
Computed new video levels for line 303
Lin
Lout
0
0
1
0.833333
2
1.666667
3
2.5
4
3.333333
5
4.166667
6
5
7
5.833333
8
6.666667
9
7.5
10
8.333333
11
9.166667
12
10
13
10.83333
14
11.66667
15
12.5
16
13.33333
17
14.16667
18
15
. . .
. . .
116
249.2687
117
249.7463
118
250.2239
119
250.7015
120
251.1791
121
251.6567
122
252.1343
123
252.6119
124
253.0896
125
253.5672
126
254.0448
127
254.5224
128
255
[0078] As already explained the complex computations are most of the cases replaced by LUTs. In the situation of the video level adjustment described as:
L out = ( L i n - LEVEL_SELECT [ n - 1 ] ) ⨯ ( LIMIT [ n ] LEVEL_SELECT [ n ] - LEVEL_SELECT [ n - 1 ] ) +
TRANS [ n - 1 ]
[0079] A 8-bit LUT takes as input the value LEVEL_SELECT[n]−LEVEL_SELECT[n−1] and delivers a certain factor (more than 10-bit resolution is mandatory) to perform the division. The rest are only multiplications and additions that can be done in real time without any problem.
[0080] As already said, the example is related to a simple gamma of 2 in a voltage driven system to simplify the exposition. For a different gamma or for a current driven system, the computations must be adjusted accordingly by using adapted LUTs.
[0081] FIG. 7 illustrates an implementation of the inventive solution. The input signal 11 is forwarded to a line analysis block 12 that performs for each input line the required parameters extraction like the highest video level per line or even histogram analysis. This block 12 requires a line memory to delay the whole process of a line. Indeed, the results of the line analysis are obtained only at the end of the line but the modifications to be done on this line must be performed on the whole line.
[0082] After the analysis and the delay of the line, the video levels are adjusted in a video adjustment block 13 . Here the new video levels Lout are generated on the basis of the original video levels Lin. The video signal with the new video levels is input to a standard OLED processing unit. 14 . Column driving data are output from this unit 14 and transmitted to a column driver 15 of an AMOLED display 16 . Furthermore, the standard OLED processing unit 14 produces row driving data for controlling the row driver 17 of the AMOLED display 16 .
[0083] Analysis data of line analysis block 12 are further provided to a voltage adjustment block 18 for adjusting a reference voltages being provided by a reference signalling unit 19 . This reference signalling unit 19 delivers reference voltages Vref n to the column driver 15 . For adjusting the reference voltages, the voltage adjustment block 18 is synchronized onto the row driving unit 17 .
[0084] The control data for programming the specific reference voltages are forwarded from voltage adjustment block 18 to the reference signalling unit 19 . The adaptation of the voltages as well as that of the video levels is done on the basis of LUTs and computation.
[0085] In case of a current driven system, the reference signalling is performed with currents and block 18 takes care of a current adjustment.
[0086] The invention is not limited to the AMOLED screens but can also be applied to LCD displays or other displays using reference signalling means.
Annex 1 - Full driver voltage table Level Voltage 0 V7 1 V7 + (V6 − V7) × 9/1175 2 V7 + (V6 − V7) × 32/1175 3 V7 + (V6 − V7) × 76/1175 4 V7 + (V6 − V7) × 141/ 1175 5 V7 + (V6 − V7) × 224/ 1175 6 V7 + (V6 − V7) × 321/ 1175 7 V7 + (V6 − V7) × 425/ 1175 8 V7 + (V6 − V7) × 529/ 1175 9 V7 + (V6 − V7) × 630/ 1175 10 V7 + (V6 − V7) × 727/ 1175 11 V7 + (V6 − V7) × 820/ 1175 12 V7 + (V6 − V7) × 910/ 1175 13 V7 + (V6 − V7) × 998/ 1175 14 V7 + (V6 − V7) × 1086/ 1175 15 V6 16 V6 + (V5 − V6) × 89/1097 17 V6 + (V5 − V6) × 173/ 1097 18 V6 + (V5 − V6) × 250/ 1097 19 V6 + (V5 − V6) × 320/ 1097 20 V6 + (V5 − V6) × 386/ 1097 21 V6 + (V5 − V6) × 451/ 1097 22 V6 + (V5 − V6) × 517/ 1097 23 V6 + (V5 − V6) × 585/ 1097 24 V6 + (V5 − V6) × 654/ 1097 25 V6 + (V5 − V6) × 723/ 1097 26 V6 + (V5 − V6) × 790/ 1097 27 V6 + (V5 − V6) × 855/ 1097 28 V6 + (V5 − V6) × 917/ 1097 29 V6 + (V5 − V6) × 977/ 1097 30 V6 + (V5 − V6) × 1037/ 1097 31 V5 32 V5 + (V4 − V5) × 60/ 1501 33 V5 + (V4 − V5) × 119/ 1501 34 V5 + (V4 − V5) × 176/ 1501 35 V5 + (V4 − V5) × 231/ 1501 36 V5 + (V4 − V5) × 284/ 1501 37 V5 + (V4 − V5) × 335/ 1501 38 V5 + (V4 − V5) × 385/ 1501 39 V5 + (V4 − V5) × 434/ 1501 40 V5 + (V4 − V5) × 483/ 1501 41 V5 + (V4 − V5) × 532/ 1501 42 V5 + (V4 − V5) × 580/ 1501 43 V5 + (V4 − V5) × 628/ 1501 44 V5 + (V4 − V5) × 676/ 1501 45 V5 + (V4 − V5) × 724/ 1501 46 V5 + (V4 − V5) × 772/ 1501 47 V5 + (V4 − V5) × 819/ 1501 48 V5 + (V4 − V5) × 866/ 1501 49 V5 + (V4 − V5) × 912/ 1501 50 V5 + (V4 − V5) × 957/ 1501 51 V5 + (V4 − V5) × 1001/ 1501 52 V5 + (V4 − V5) × 1045/ 1501 53 V5 + (V4 − V5) × 1088/ 1501 54 V5 + (V4 − V5) × 1131/ 1501 55 V5 + (V4 − V5) × 1173/ 1501 56 V5 + (V4 − V5) × 1215/ 1501 57 V5 + (V4 − V5) × 1257/ 1501 58 V5 + (V4 − V5) × 1298/ 1501 59 V5 + (V4 − V5) × 1339/ 1501 60 V5 + (V4 − V5) × 1380/ 1501 61 V5 + (V4 − V5) × 1421/ 1501 62 V5 + (V4 − V5) × 1461/ 1501 63 V4 64 V4 + (V3 − V4) × 40/2215 65 V4 + (V3 − V4) × 80/2215 66 V4 + (V3 − V4) × 120/ 2215 67 V4 + (V3 − V4) × 160/ 2215 68 V4 + (V3 − V4) × 200/ 2215 69 V4 + (V3 − V4) × 240/ 2215 70 V4 + (V3 − V4) × 280/ 2215 71 V4 + (V3 − V4) × 320/ 2215 72 V4 + (V3 − V4) × 360/ 2215 73 V4 + (V3 − V4) × 400/ 2215 74 V4 + (V3 − V4) × 440/ 2215 75 V4 + (V3 − V4) × 480/ 2215 76 V4 + (V3 − V4) × 520/ 2215 77 V4 + (V3 − V4) × 560/ 2215 78 V4 + (V3 − V4) × 600/ 2215 79 V4 + (V3 − V4) × 640/ 2215 80 V4 + (V3 − V4) × 680/ 2215 81 V4 + (V3 − V4) × 719/ 2215 82 V4 + (V3 − V4) × 758/ 2215 83 V4 + (V3 − V4) × 796/ 2215 84 V4 + (V3 − V4) × 834/ 2215 85 V4 + (V3 − V4) × 871/ 2215 86 V4 + (V3 − V4) × 908/ 2215 87 V4 + (V3 − V4) × 944/ 2215 88 V4 + (V3 − V4) × 980/ 2215 89 V4 + (V3 − V4) × 1016/ 2215 90 V4 + (V3 − V4) × 1052/ 2215 91 V4 + (V3 − V4) × 1087/ 2215 92 V4 + (V3 − V4) × 1122/ 2215 93 V4 + (V3 − V4) × 1157/ 2215 94 V4 + (V3 − V4) × 1192/ 2215 95 V4 + (V3 − V4) × 1226/ 2215 96 V4 + (V3 − V4) × 1260/ 2215 97 V4 + (V3 − V4) × 1294/ 2215 98 V4 + (V3 − V4) × 1328/ 2215 99 V4 + (V3 − V4) × 1362/ 2215 100 V4 + (V3 − V4) × 1396/ 2215 101 V4 + (V3 − V4) × 1429/ 2215 102 V4 + (V3 − V4) × 1462/ 2215 103 V4 + (V3 − V4) × 1495/ 2215 104 V4 + (V3 − V4) × 1528/ 2215 105 V4 + (V3 − V4) × 1561/ 2215 106 V4 + (V3 − V4) × 1593/ 2215 107 V4 + (V3 − V4) × 1625/ 2215 108 V4 + (V3 − V4) × 1657/ 2215 109 V4 + (V3 − V4) × 1688/ 2215 110 V4 + (V3 − V4) × 1719/ 2215 111 V4 + (V3 − V4) × 1750/ 2215 112 V4 + (V3 − V4) × 1781/ 2215 113 V4 + (V3 − V4) × 1811/ 2215 114 V4 + (V3 − V4) × 1841/ 2215 115 V4 + (V3 − V4) × 1871/ 2215 116 V4 + (V3 − V4) × 1901/ 2215 117 V4 + (V3 − V4) × 1930/ 2215 118 V4 + (V3 − V4) × 1959/ 2215 119 V4 + (V3 − V4) × 1988/ 2215 120 V4 + (V3 − V4) × 2016/ 2215 121 V4 + (V3 − V4) × 2044/ 2215 122 V4 + (V3 − V4) × 2072/ 2215 123 V4 + (V3 − V4) × 2100/ 2215 124 V4 + (V3 − V4) × 2128/ 2215 125 V4 + (V3 − V4) × 2156/ 2215 126 V4 + (V3 − V4) × 2185/ 2215 127 V3 128 V3 + (V2 − V3) × 31/2343 129 V3 + (V2 − V3) × 64/2343 130 V3 + (V2 − V3) × 97/2343 131 V3 + (V2 − V3) × 130/ 2343 132 V3 + (V2 − V3) × 163/ 2343 133 V3 + (V2 − V3) × 196/ 2343 134 V3 + (V2 − V3) × 229/ 2343 135 V3 + (V2 − V3) × 262/ 2343 136 V3 + (V2 − V3) × 295/ 2343 137 V3 + (V2 − V3) × 328/ 2343 138 V3 + (V2 − V3) × 361/ 2343 139 V3 + (V2 − V3) × 395/ 2343 140 V3 + (V2 − V3) × 429/ 2343 141 V3 + (V2 − V3) × 463/ 2343 142 V3 + (V2 − V3) × 497/ 2343 143 V3 + (V2 − V3) × 531/ 2343 144 V3 + (V2 − V3) × 566/ 2343 145 V3 + (V2 − V3) × 601/ 2343 146 V3 + (V2 − V3) × 636/ 2343 147 V3 + (V2 − V3) × 671/ 2343 148 V3 + (V2 − V3) × 706/ 2343 149 V3 + (V2 − V3) × 741/ 2343 150 V3 + (V2 − V3) × 777/ 2343 151 V3 + (V2 − V3) × 813/ 2343 152 V3 + (V2 − V3) × 849/ 2343 153 V3 + (V2 − V3) × 885/ 2343 154 V3 + (V2 − V3) × 921/ 2343 155 V3 + (V2 − V3) × 958/ 2343 156 V3 + (V2 − V3) × 995/ 2343 157 V3 + (V2 − V3) × 1032/ 2343 158 V3 + (V2 − V3) × 1069/ 2343 159 V3 + (V2 − V3) × 1106/ 2343 160 V3 + (V2 − V3) × 1143/ 2343 161 V3 + (V2 − V3) × 1180/ 2343 162 V3 + (V2 − V3) × 1217/ 2343 163 V3 + (V2 − V3) × 1255/ 2343 164 V3 + (V2 − V3) × 1293/ 2343 165 V3 + (V2 − V3) × 1331/ 2343 166 V3 + (V2 − V3) × 1369/ 2343 167 V3 + (V2 − V3) × 1407/ 2343 168 V3 + (V2 − V3) × 1445/ 2343 169 V3 + (V2 − V3) × 1483/ 2343 170 V3 + (V2 − V3) × 1521/ 2343 171 V3 + (V2 − V3) × 1559/ 2343 172 V3 + (V2 − V3) × 1597/ 2343 173 V3 + (V2 − V3) × 1635/ 2343 174 V3 + (V2 − V3) × 1673/ 2343 175 V3 + (V2 − V3) × 1712/ 2343 176 V3 + (V2 − V3) × 1751/ 2343 177 V3 + (V2 − V3) × 1790/ 2343 178 V3 + (V2 − V3) × 1829/ 2343 179 V3 + (V2 − V3) × 1868/ 2343 180 V3 + (V2 − V3) × 1907/ 2343 181 V3 + (V2 − V3) × 1946/ 2343 182 V3 + (V2 − V3) × 1985/ 2343 183 V3 + (V2 − V3) × 2024/ 2343 184 V3 + (V2 − V3) × 2064/ 2343 185 V3 + (V2 − V3) × 2103/ 2343 186 V3 + (V2 − V3) × 2143/ 2343 187 V3 + (V2 − V3) × 2183/ 2343 188 V3 + (V2 − V3) × 2223/ 2343 189 V3 + (V2 − V3) × 2263/ 2343 190 V3 + (V2 − V3) × 2303/ 2343 191 V2 192 V2 + (V1 − V2) × 40/1638 193 V2 + (V1 − V2) × 81/1638 194 V2 + (V1 − V2) × 124/ 1638 195 V2 + (V1 − V2) × 168/ 1638 196 V2 + (V1 − V2) × 213/ 1638 197 V2 + (V1 − V2) × 259/ 1638 198 V2 + (V1 − V2) × 306/ 1638 199 V2 + (V1 − V2) × 353/ 1638 200 V2 + (V1 − V2) × 401/ 1638 201 V2 + (V1 − V2) × 450/ 1638 202 V2 + (V1 − V2) × 499/ 1638 203 V2 + (V1 − V2) × 548/ 1638 204 V2 + (V1 − V2) × 597/ 1638 205 V2 + (V1 − V2) × 646/ 1638 206 V2 + (V1 − V2) × 695/ 1638 207 V2 + (V1 − V2) × 745/ 1638 208 V2 + (V1 − V2) × 795/ 1638 209 V2 + (V1 − V2) × 846/ 1638 210 V2 + (V1 − V2) × 897/ 1638 211 V2 + (V1 − V2) × 949/ 1638 212 V2 + (V1 − V2) × 1002/ 1638 213 V2 + (V1 − V2) × 1056/ 1638 214 V2 + (V1 − V2) × 1111/ 1638 215 V2 + (V1 − V2) × 1167/ 1638 216 V2 + (V1 − V2) × 1224/ 1638 217 V2 + (V1 − V2) × 1281/ 1638 218 V2 + (V1 − V2) × 1339/ 1638 219 V2 + (V1 − V2) × 1398/ 1638 220 V2 + (V1 − V2) × 1458/ 1638 221 V2 + (V1 − V2) × 1518/ 1638 222 V2 + (V1 − V2) × 1578/ 1638 223 V1 224 V1 + (V0 − V1) × 60/3029 225 V1 + (V0 − V1) × 120/ 3029 226 V1 + (V0 − V1) × 180/ 3029 227 V1 + (V0 − V1) × 241/ 3029 228 V1 + (V0 − V1) × 304/ 3029 229 V1 + (V0 − V1) × 369/ 3029 230 V1 + (V0 − V1) × 437/ 3029 231 V1 + (V0 − V1) × 507/ 3029 232 V1 + (V0 − V1) × 580/ 3029 233 V1 + (V0 − V1) × 655/ 3029 234 V1 + (V0 − V1) × 732/ 3029 235 V1 + (V0 − V1) × 810/ 3029 236 V1 + (V0 − V1) × 889/ 3029 237 V1 + (V0 − V1) × 969/ 3029 238 V1 + (V0 − V1) × 1050/ 3029 239 V1 + (V0 − V1) × 1133/ 3029 240 V1 + (V0 − V1) × 1218/ 3029 241 V1 + (V0 − V1) × 1304/ 3029 242 V1 + (V0 − V1) × 1393/ 3029 243 V1 + (V0 − V1) × 1486/ 3029 244 V1 + (V0 − V1) × 1583/ 3029 245 V1 + (V0 − V1) × 1686/ 3029 246 V1 + (V0 − V1) × 1794/ 3029 247 V1 + (V0 − V1) × 1907/ 3029 248 V1 + (V0 − V1) × 2026/ 3029 249 V1 + (V0 − V1) × 2150/ 3029 250 V1 + (V0 − V1) × 2278/ 3029 251 V1 + (V0 − V1) × 2411/ 3029 252 V1 + (V0 − V1) × 2549/ 3029 253 V1 + (V0 − V1) × 2694/ 3029 254 V1 + (V0 − V1) × 2851/ 3029 255 V0
[0087]
Annex 2 - Histogram of line 303 from sequence “Zorro”
Level
Occurrence
0
27
1
13
2
1
3
2
4
3
5
4
6
3
7
0
8
1
9
1
10
2
11
0
12
5
13
7
14
4
15
8
16
9
17
19
18
29
19
50
20
35
21
37
22
24
23
26
24
19
25
23
26
12
27
24
28
26
29
23
30
25
31
31
32
56
33
54
34
64
35
61
36
78
37
42
38
59
39
61
40
75
41
78
42
61
43
41
44
55
45
52
46
43
47
48
48
42
49
42
50
46
51
45
52
28
53
29
54
27
55
26
56
28
57
25
58
25
59
33
60
39
61
38
62
38
63
25
64
23
65
12
66
11
67
22
68
13
69
5
70
4
71
5
72
6
73
13
74
8
75
3
76
7
77
6
78
4
79
2
80
2
81
2
82
4
83
5
84
3
85
3
86
6
87
2
88
1
89
3
90
2
91
0
92
3
93
0
94
1
95
1
96
0
97
1
98
0
99
1
100
0
101
0
102
0
103
1
104
1
105
1
106
0
107
2
108
0
109
0
110
1
111
1
112
0
113
1
114
0
115
0
116
0
117
2
118
1
119
0
120
1
121
0
122
0
123
2
124
0
125
1
126
1
127
2
128
1
129
0
130
0
131
0
132
0
133
0
134
0
135
0
136
0
137
0
138
0
139
0
140
0
141
0
142
0
143
0
144
0
145
0
146
0
147
0
148
0
149
0
150
0
151
0
152
0
153
0
154
0
155
0
156
0
157
0
158
0
159
0
160
0
161
0
162
0
163
0
164
0
165
0
166
0
167
0
168
0
169
0
170
0
171
0
172
0
173
0
174
0
175
0
176
0
177
0
178
0
179
0
180
0
181
0
182
0
183
0
184
0
185
0
186
0
187
0
188
0
189
0
190
0
191
0
192
0
193
0
194
0
195
0
196
0
197
0
198
0
199
0
200
0
201
0
202
0
203
0
204
0
205
0
206
0
207
0
208
0
209
0
210
0
211
0
212
0
213
0
214
0
215
0
216
0
217
0
218
0
219
0
220
0
221
0
222
0
223
0
224
0
225
0
226
0
227
0
228
0
229
0
230
0
231
0
232
0
233
0
234
0
235
0
236
0
237
0
238
0
239
0
240
0
241
0
242
0
243
0
244
0
245
0
246
0
247
0
248
0
249
0
250
0
251
0
252
0
253
0
254
0
255
0 | A method and an apparatus capable of increasing the video depths depending on the video content of each line in order to provide a maximum of color gradation for each given scene shall be proposed. For this purpose there is disclosed an apparatus for driving a display device including input means for receiving a digital value as video level for each pixel or cell of a line of the display device, reference signalling means for providing at least one reference driving signal and driving means for generating a driving signal on the basis of the digital value and the at least one reference driving signal. The apparatus further includes adjusting means for adjusting the at least one reference driving signal in dependence of the digital values of at least a part of the line. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is a continuation-in-part of U.S. patent application Ser. No. 13/411,407 entitled VENTILATION MASK WITH INTEGRATED PILOTED EXHALATION VALVE filed Mar. 2, 2012, which is a continuation of U.S. patent application Ser. No. 13/411,348 entitled VENTILATION MASK WITH INTEGRATED PILOTED EXHALATION VALVE filed Mar. 2, 2012, which claims priority to U.S. Provisional Patent Application Ser. No. 61/499,950 entitled VENTILATION MASK WITH INTEGRATED PILOTED EXHALATION VALVE filed Jun. 22, 2011 and U.S. Provisional Patent Application Ser. No. 61/512,750 entitled VENTILATION MASK WITH INTEGRATED PILOTED EXHALATION VALVE AND METHOD OF VENTILATING A PATIENT USING THE SAME filed Jul. 28, 2011, the disclosures of which are incorporated herein by reference.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to systems and methods for controlling delivery of a pressurized flow of breathable gas to a patient and, more particularly, to a ventilation mask such as a full face mask, nasal mask, nasal prongs mask or nasal pillows mask for use in critical care ventilation, respiratory insufficiency or OSA (obstructive sleep apnea) with CPAP (Continuous Positive Airway Pressure) therapy and incorporating a piloted exhalation valve inside the mask.
[0005] 2. Description of the Related Art
[0006] As is known in the medical arts, mechanical ventilators comprise medical devices that either perform or supplement breathing for patients. Early ventilators, such as the “iron lung”, created negative pressure around the patient's chest to cause a flow of ambient air through the patient's nose and/or mouth into their lungs. However, the vast majority of contemporary ventilators instead use positive pressure to deliver gas to the patient's lungs via a patient circuit between the ventilator and the patient. The patient circuit typically consists of one or two large bore tubes (e.g., from 22 mm ID for adults to 8 mm ID for pediatric) that interface to the ventilator on one end, and a patient mask on the other end. Most often, the patient mask is not provided as part of the ventilator system, and a wide variety of patient masks can be used with any ventilator. The interfaces between the ventilator, patient circuit and patient masks are standardized as generic conical connectors, the size and shape of which are specified by regulatory bodies (e.g., ISO 5356-1 or similar standards).
[0007] Current ventilators are designed to support either “vented” or “leak” circuits, or “non-vented” or “non-leak” circuits. In vented circuits, the mask or patient interface is provided with an intentional leak, usually in the form of a plurality of vent openings. Ventilators using this configuration are most typically used for less acute clinical requirements, such as the treatment of obstructive sleep apnea or respiratory insufficiency. In non-vented circuits, the patient interface is usually not provided with vent openings. Non-vented circuits can have single limb or dual limb patient circuits, and an exhalation valve. Ventilators using non-vented patient circuits are most typically used for critical care applications.
[0008] Vented patient circuits are used only to carry gas flow from the ventilator to the patient and patient mask, and require a patient mask with vent openings. When utilizing vented circuits, the patient inspires fresh gas from the patient circuit, and expires CO2-enriched gas, which is purged from the system through the vent openings in the mask. This constant purging of flow through vent openings in the mask when using single-limb circuits provides several disadvantages: 1) it requires the ventilator to provide significantly more flow than the patient requires, adding cost/complexity to the ventilator and requiring larger tubing; 2) the constant flow through the vent openings creates and conducts noise, which has proven to be a significant detriment to patients with sleep apnea that are trying to sleep while wearing the mask; 3) the additional flow coming into proximity of the patient's nose and then exiting the system often causes dryness in the patient, which often drives the need for adding humidification to the system; and 4) patient-expired CO2 flows partially out of the vent holes in the mask and partially into the patient circuit tubing, requiring a minimum flow through the tubing at all times in order to flush the CO2 and minimize the re-breathing of exhaled CO2. To address the problem of undesirable flow of patient-expired CO2 back into the patient circuit tubing, currently known CPAP systems typically have a minimum-required pressure of 4 cmH2O whenever the patient is wearing the mask, which often produces significant discomfort, claustrophobia and/or feeling of suffocation to early CPAP users and leads to a high (approximately 50%) non-compliance rate with CPAP therapy.
[0009] When utilizing non-vented dual limb circuits, the patient inspires fresh gas from one limb (the “inspiratory limb”) of the patient circuit and expires CO2-enriched gas from the second limb (the “expiratory limb”) of the patient circuit. Both limbs of the dual limb patient circuit are connected together in a “Y” proximal to the patient to allow a single conical connection to the patient mask. When utilizing non-vented single limb circuits, an expiratory valve is placed along the circuit, usually proximal to the patient. During the inhalation phase, the exhalation valve is closed to the ambient and the patient inspires fresh gas from the single limb of the patient circuit. During the exhalation phase, the patient expires CO2-enriched gas from the exhalation valve that is open to ambient. The single limb and exhalation valve are usually connected to each other and to the patient mask with conical connections.
[0010] In the patient circuits described above, the ventilator pressurizes the gas to be delivered to the patient inside the ventilator to the intended patient pressure, and then delivers that pressure to the patient through the patient circuit. Very small pressure drops develop through the patient circuit, typically around 1 cmH2O, due to gas flow though the small amount of resistance created by the tubing. Some ventilators compensate for this small pressure drop either by mathematical algorithms, or by sensing the tubing pressure more proximal to the patient.
[0011] Ventilators that utilize a dual limb patient circuit typically include an exhalation valve at the end of the expiratory limb proximal to the ventilator, while ventilators that utilize a single limb, non-vented patient circuit typically include an exhalation valve at the end of the single limb proximal to the patient as indicated above. Exhalation valves can have fixed or adjustable PEEP (positive expiratory end pressure), typically in single limb configurations, or can be controlled by the ventilator. The ventilator controls the exhalation valve, closes it during inspiration, and opens it during exhalation. Less sophisticated ventilators have binary control of the exhalation valve, in that they can control it to be either open or closed. More sophisticated ventilators are able to control the exhalation valve in an analog fashion, allowing them to control the pressure within the patient circuit by incrementally opening or closing the valve. Valves that support this incremental control are referred to as active exhalation valves. In existing ventilation systems, active exhalation valves are most typically implemented physically within the ventilator, and the remaining few ventilation systems with active exhalation valves locate the active exhalation valve within the patient circuit proximal to the patient. Active exhalation valves inside ventilators are typically actuated via an electromagnetic coil in the valve, whereas active exhalation valves in the patient circuit are typically pneumatically piloted from the ventilator through a separate pressure source such a secondary blower, or through a proportional valve modulating the pressure delivered by the main pressure source.
BRIEF SUMMARY OF THE INVENTION
[0012] In accordance with the present invention, there is provided a mask (e.g., a nasal pillows mask) for achieving positive pressure mechanical ventilation (inclusive of CPAP, ventilatory support, critical care ventilation, emergency applications), and a method for a operating a ventilation system including such mask. The mask preferably includes a pressure sensing modality proximal to the patient connection. Such pressure sensing modality may be a pneumatic port with tubing that allows transmission of the patient pressure back to the ventilator for measurement, or may include a transducer within the mask. The pressure sensing port is used in the system to allow pressure sensing for achieving and/or monitoring the therapeutic pressures. Alternately or additionally, the mask may include a flow sensing modality located therewithin for achieving and/or monitoring the therapeutic flows.
[0013] The mask of the present invention also includes a piloted exhalation valve that is used to achieve the target pressures/flows to the patient. In the preferred embodiment, the pilot for the valve is pneumatic and driven from the gas supply tubing from the ventilator. The pilot can also be a preset pressure derived in the mask, a separate pneumatic line from the ventilator, or an electro-mechanical control. In accordance with the present invention, the valve is preferably implemented with a diaphragm.
[0014] One of the primary benefits attendant to including the valve inside the mask is that it provides a path for patient-expired CO2 to exit the system without the need for a dual-limb patient circuit, and without the disadvantages associated with a single-limb patient circuit, such as high functional dead space. For instance, in applications treating patients with sleep apnea, having the valve inside the mask allows patients to wear the mask while the treatment pressure is turned off without risk of re-breathing excessive CO2.
[0015] Another benefit for having the valve inside the mask is that it allows for a significant reduction in the required flow generated by the ventilator for ventilating the patient since a continuous vented flow for CO2 washout is not required. Lower flow in turn allows for the tubing size to be significantly smaller (e.g., 2-9 mm ID) compared to conventional ventilators (22 mm ID for adults; 8 mm ID for pediatric). However, this configuration requires higher pressures than the patient's therapeutic pressure to be delivered by the ventilator. In this regard, pressure from the ventilator is significantly higher than the patient's therapeutic pressure, though the total pneumatic power delivered is still smaller than that delivered by a low pressure, high flow ventilator used in conjunction with a vented patient circuit and interface. One obvious benefit of smaller tubing is that it provides less bulk for patient and/or caregivers to manage. For today's smallest ventilators, the bulk of the tubing is as significant as the bulk of the ventilator. Another benefit of the smaller tubing is that is allows for more convenient ways of affixing the mask to the patient. For instance, the tubing can go around the patient's ears to hold the mask to the face, instead of requiring straps (typically called “headgear”) to affix the mask to the face. Along these lines, the discomfort, complication, and non-discrete look of the headgear is another significant factor leading to the high non-compliance rate for CPAP therapy. Another benefit to the smaller tubing is that the mask can become smaller because it does not need to interface with the large tubing. Indeed, large masks are another significant factor leading to the high non-compliance rate for CPAP therapy since, in addition to being non-discrete, they often cause claustrophobia. Yet another benefit is that smaller tubing more conveniently routed substantially reduces what is typically referred to as “tube drag” which is the force that the tube applies to the mask, displacing it from the patient's face. This force has to be counterbalanced by headgear tension, and the mask movements must be mitigated with cushion designs that have great compliance. The reduction in tube drag in accordance with the present invention allows for minimal headgear design (virtually none), reduced headgear tension for better patient comfort, and reduced cushion compliance that results in a smaller, more discrete cushion.
[0016] The mask of the present invention may further include a heat and moisture exchanger (HME) which is integrated therein. The HME can fully or at least partially replace a humidifier (cold or heated pass-over; active or passive) which may otherwise be included in the ventilation system employing the use of the mask. The HME is positioned within the mask so as to be able to intercept the flow delivered from a flow generator to the patient in order to humidify it, and further to intercept the exhaled flow of the patient in order to capture humidity and heat for the next breath. The HME can also be used as a structural member of the mask, adding q cushioning effect and simplifying the design of the cushion thereof.
[0017] The present invention is best understood by reference to the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] These, as well as other features of the present invention, will become more apparent upon reference to the drawings wherein:
[0019] FIG. 1 is top perspective view of a nasal pillows mask constructed in accordance with the present invention and including an integrated diaphragm-based piloted exhalation valve;
[0020] FIG. 2 is an exploded view of the nasal pillows mask shown in FIG. 1 ;
[0021] FIG. 3 is a partial cross-sectional view of the nasal pillows mask shown in FIG. 1 taken along lines 3 - 3 thereof, and depicting the valve pilot lumen extending through the cushion of the mask;
[0022] FIG. 4 is a partial cross-sectional view of the nasal pillows mask shown in FIG. 1 taken along lines 4 - 4 thereof, and depicting the pressure sensing lumen extending through the cushion of the mask;
[0023] FIG. 5 is a cross-sectional view of the nasal pillows mask shown in FIG. 1 taken along lines 5 - 5 thereof;
[0024] FIG. 6 is a top perspective view of cushion of the nasal pillows mask shown in FIG. 1 ;
[0025] FIG. 7 is a top perspective view of exhalation valve of the nasal pillows mask shown in FIG. 1 ;
[0026] FIG. 8 is a bottom perspective view of exhalation valve shown in FIG. 7 ;
[0027] FIG. 9 is a cross-sectional view of exhalation valve shown in FIGS. 7 and 8 ;
[0028] FIG. 10 is a cross-sectional view similar to FIG. 5 , but depicting a variant of the nasal pillows mask wherein an HME is integrated into the cushion thereof;
[0029] FIGS. 11A , 11 B and 11 C are a series of graphs which provide visual representations corresponding to exemplary performance characteristics of the exhalation valve subassembly of the nasal pillows mask of the present invention;
[0030] FIG. 12 is a schematic representation of an exemplary ventilation system wherein a tri-lumen tube is used to facilitate the operative interface between the nasal pillows mask and a flow generating device;
[0031] FIG. 13 is a schematic representation of an exemplary ventilation system wherein a bi-lumen tube is used to facilitate the operative interface between the nasal pillows mask and a flow generating device;
[0032] FIG. 14 is a side-elevational view of the nasal pillows mask of the present invention depicting an exemplary manner of facilitating the cooperative engagement thereof to a patient through the use of a headgear assembly;
[0033] FIG. 15 is a front-elevational view of the nasal pillows mask of the present invention depicting an exemplary tri-lumen tube, Y-connector, and pair of bi-lumen tubes which are used to collectively facilitate the operative interface between the nasal pillows mask and a flow generating device in accordance with the schematic representation shown in FIG. 12 ;
[0034] FIG. 16 is an exploded view of the tri-lumen tube, Y-connector and bi-lumen tubes shown in FIG. 15 ;
[0035] FIG. 17 is a perspective view of the Y-connector shown in FIGS. 15 and 16 in its disconnected state;
[0036] FIG. 18 is a side-elevational view of the Y-connector shown in FIGS. 15 , 16 and 17 in its disconnected state;
[0037] FIG. 19 is a cross-sectional view of one of the identically configured bi-lumen tubes taken along line 19 - 19 of FIG. 16 ;
[0038] FIG. 20 is a cross-sectional view of the tri-lumen tube taken along line 20 - 20 of FIG. 16 ;
[0039] FIG. 21 is a cross-sectional view of the tri-lumen tube, Y-connector and bi-lumen tubes shown in FIG. 15 as operatively connected to each other;
[0040] FIG. 22 is a cross-sectional view of one of the identically configured bi-lumen tubes shown in FIGS. 15 and 16 , but further illustrating in more detail the generally elliptical profile of the gas delivery lumen thereof relative to the generally circular profile of a corresponding connector of the nasal pillows mask which is advanced therein;
[0041] FIG. 23 is a cross-sectional view of one of the identically configured bi-lumen tubes which is similar to FIG. 22 , but further illustrates the manner in which the receipt of a corresponding, generally circular connector of the nasal pillows mask or Y-connector into the generally elliptical gas delivery lumen facilitates the compression of a portion of the bi-lumen tube as effectively maintains the frictional and airtight engagement thereof with the nasal pillows mask;
[0042] FIG. 24 is a perspective view of a segment of a quad-lumen tube which may be used an alternative to the tri-lumen tube shown in FIGS. 15-16 and 19 - 20 ; and
[0043] FIG. 25 is a cross-sectional view of the quad-lumen tube taken along line 25 - 25 of FIG. 24 ;
[0044] Common reference numerals are used throughout the drawings and detailed description to indicate like elements.
DETAILED DESCRIPTION OF THE INVENTION
[0045] Referring now to the drawings wherein the showings are for purposes of illustrating various embodiments of the present invention only, and not for purposes of limiting the same, FIGS. 1-4 depict a ventilation mask 10 (e.g., a nasal pillows mask) constructed in accordance with the present invention. Though the mask 10 is depicted as a nasal pillows mask, those skilled in the art will recognize that other ventilation masks are contemplated herein, such as nasal prongs masks, nasal masks, fill face masks and oronasal masks. As such, for purposes of this application, the term mask and/or ventilation mask is intended to encompass all such mask structures. The mask 10 includes an integrated, diaphragm-implemented, piloted exhalation valve 12 , the structural and functional attributes of which will be described in more detail below.
[0046] As shown in FIGS. 1-5 , the mask 10 comprises a housing or cushion 14 . The cushion 14 , which is preferably fabricated from a silicone elastomer having a Shore A hardness in the range of from about 20 to 60 and preferably about 40, is formed as a single, unitary component, and is shown individually in FIG. 6 . The cushion 14 includes a main body portion 16 which defines a first outer end surface 18 and an opposed second outer end surface 20 . The main body portion 16 further defines an interior fluid chamber 22 which is of a prescribed volume. In addition to the main body portion 16 , the cushion 14 includes an identically configured pair of hollow pillow portions 24 which protrude from the main body portion 16 in a common direction and in a prescribed spatial relationship relative to each other. More particularly, in the cushion 14 , the spacing between the pillow portions 24 is selected to facilitate the general alignment thereof with the nostrils of an adult patient when the mask 10 is worn by such patient. As seen in FIGS. 3 and 4 , each of the pillow portions 24 fluidly communicates with the fluid chamber 22 .
[0047] As shown in FIG. 2 , the main body portion 16 of the cushion 14 includes an enlarged, circularly configured valve opening 26 which is in direct fluid communication with the fluid chamber 22 . The valve opening 26 is positioned in generally opposed relation to the pillow portions 24 of the cushion 14 , and is circumscribed by an annular valve seat 27 also defined by the main body portion 16 . As also shown in FIG. 2 , the main body portion 16 further defines opposed first and second inner end surfaces 28 , 30 which protrude outwardly from the periphery of the valve opening 26 , and are diametrically opposed relative thereto so as to be spaced by an interval of approximately 180°. The valve opening 26 , valve seat 27 , and first and second inner end surfaces 28 , 30 are adapted to accommodate the exhalation valve 12 of the mask 10 in a manner which will be described in more detail below.
[0048] As shown FIGS. 3-6 , the main body portion 16 of the cushion 14 further defines first and second gas delivery lumens 32 , 34 which extend from respective ones of the first and second outer end surfaces 18 , 20 into fluid communication with the fluid chamber 22 . Additionally, a pressure sensing lumen 36 defined by the main body portion extends from the first outer end surface 18 into fluid communication with the fluid chamber 22 . The main body portion 16 further defines a valve pilot lumen 38 which extends between the second outer end surface 20 and the second inner end surface 30 . The use of the first and second gas delivery lumens 32 , 34 , the pressure sensing lumen 36 , and the valve pilot lumen 38 will also be discussed in more detail below. Those of ordinary skill in the art will recognize that the gas delivery lumens 32 , 34 , may be substituted with a single gas delivery lumen and/or positioned within the cushion 14 in orientations other than those depicted in FIG. 6 . For example, the gas delivery lumen(s) of the cushion 14 may be positioned frontally, pointing upwardly, pointing downwardly, etc. rather than extending laterally as shown in FIG. 6 .
[0049] Referring now to FIGS. 2-5 and 7 - 9 , the exhalation valve 12 of the mask 10 is made of three (3) parts or components, and more particularly a seat member 40 , a cap member 42 , and a diaphragm 44 which is operatively captured between the seat and cap members 40 , 42 . The seat and cap members 40 , 42 are each preferably fabricated from a plastic material, with the diaphragm 44 preferably being fabricated from an elastomer having a Shore A hardness in the range of from about 20-40.
[0050] As is most easily seen in FIGS. 2 , 7 and 9 , the seat member 40 includes a tubular, generally cylindrical wall portion 46 which defines a distal, annular outer rim 48 and an opposed annular inner seating surface 49 . As shown in FIG. 9 , the diameter of the outer rim 48 exceeds that of the seating surface 49 . Along these lines, the inner surface of the wall portion 46 is not of a uniform inner diameter, but rather is segregated into first and second inner surface sections which are of differing inner diameters, and separated by an annular shoulder 51 . In addition to the wall portion 46 , the seat member 40 includes an annular flange portion 50 which protrudes radially from that end of the wall portion 46 opposite the outer rim 48 . As shown in FIGS. 2 and 7 , the flange portion 50 includes a plurality of exhaust vents 52 which are located about the periphery thereof in a prescribed arrangement and spacing relative to each other. Additionally, as is apparent from FIG. 9 , the seat member 40 is formed such that each of the exhaust vents 52 normally fluidly communicates with the bore or fluid conduit defined by the wall portion 46 .
[0051] The cap member 42 of the exhaust valve 12 comprises a circularly configured base portion 54 which defines an inner surface 56 and an opposed outer surface 58 . In addition to the base portion 54 , the cap member 42 includes an annular flange portion 60 which circumvents and protrudes generally perpendicularly relative to the inner surface 56 of the base portion 60 . The flange portion 60 defines a distal annular shoulder 62 . As shown in FIG. 9 , the shoulder 62 and inner surface 56 extend along respective ones of a spaced, generally parallel pair of planes. Further, as shown in FIG. 8 , formed in the outer surface 58 of the base portion 54 is an elongate groove 64 which extends diametrically across the outer surface 58 . The use of the groove 64 will be described in more detail below. The seat and cap members 40 , 42 , when attached to each other in the fully assembled exhalation valve 12 , collectively define an interior valve chamber 59 of the exhalation valve 12 . More particularly, such valve chamber 59 is generally located between the inner surface 56 defined by the base portion 54 of the cap member 42 and the seating surface 49 defined by the wall portion 46 of the seat member 40 .
[0052] The diaphragm 44 of the exhalation valve 12 , which resides within the valve chamber 59 , has a circularly configured, central body portion 66 , and a peripheral flange portion 68 which is integrally connected to and circumvents the body portion 66 . The body portion 66 includes an annular lip 72 which circumvents and protrudes upwardly from one side or face thereof. The flange portion 68 includes an arcuately contoured primary region and a distal region which protrudes radially from the primary region. As such, the primary region of the flange portion 68 extends between the distal region thereof and the body portion 66 , and defines a continuous, generally concave channel 70 .
[0053] In the exhalation valve 12 , the flange portion 68 of the diaphragm 44 is operatively captured between the flange portions 50 , 60 of the seat and cap members 40 , 42 . More particularly, the annular distal region of the flange portion 68 is compressed (and thus captured) between the shoulder 62 defined by the flange portion 60 of the cap member 42 , and a complimentary annular shoulder 53 which is defined by the flange portion 50 of the seat member 40 proximate the exhaust vents 52 . The orientation of the diaphragm 44 within the valve chamber 59 when captured between the seat and cap members 40 , 42 is such that the channel 70 defined by the arcuately contoured primary region of the flange portion 68 is directed toward or faces the seating surface 49 defined by the wall portion 46 of the seat member 40 .
[0054] The diaphragm 44 (and hence the exhalation valve 12 ) is selectively moveable between an open position (shown in FIGS. 3-5 and 9 ) and a closed position. When in its normal, open position, the diaphragm 44 is in a relaxed, unbiased state. Importantly, in either of its open or closed positions, the diaphragm 44 is not normally seated directly against the inner surface 56 defined by the base portion 54 of the cap member 42 . Rather, a gap is normally maintained between the body portion 66 of the diaphragm 44 and the inner surface 56 of the base portion 54 . The width of such gap when the diaphragm 44 is in its open position is generally equal to the fixed distance separating the inner surface 56 of the base portion 54 from the shoulder 62 of the flange portion 60 . Further, when the diaphragm 44 is in its open position, the body portion 66 , and in particular the lip 72 protruding therefrom, is itself disposed in spaced relation to the seating surface 49 defined by the wall portion 46 of the seat member 40 . As such, when the diaphragm 44 is in its open position, fluid is able to freely pass through the fluid conduit defined by the wall portion 46 , between the seating surface 49 and diaphragm 44 , and through the exhaust vents 52 to ambient air. As shown in FIGS. 3 , 8 and 9 , the flange portion 60 of the cap member 42 is further provided with a pilot port 74 which extends therethrough and, in the fully assembled exhalation valve 12 , fluidly communicates with that portion of the valve chamber 59 disposed between the body portion 66 of the diaphragm 44 and the inner surface 56 of the base portion 54 . The use of the pilot port 74 will also be described in more detail below.
[0055] As will be discussed in more detail below, in the exhalation valve 12 , the diaphragm 44 is resiliently deformable from its open position (to which it may be normally biased) to its closed position. An important feature of the present invention is that the diaphragm 44 is normally biased to its open position which provides a failsafe to allow a patient to inhale ambient air through the exhalation valve 12 and exhale ambient air therethrough (via the exhaust vents 52 ) during any ventilator malfunction or when the mask is worn without the therapy being delivered by the ventilator. When the diaphragm 44 is moved or actuated to its closed position, the lip 72 of the body portion 66 is firmly seated against the seating surface 49 defined by the wall portion 46 of the seat member 40 . The seating of the lip 72 against the seating surface 49 effectively blocks fluid communication between the fluid conduit defined by the wall portion 46 and the valve chamber 59 (and hence the exhaust vents 52 which fluidly communicate with the valve chamber 59 ).
[0056] In the mask 10 , the cooperative engagement between the exhalation valve 12 and the cushion 14 is facilitated by the advancement of the wall portion 46 of the seat member 40 into the valve opening 26 defined by the cushion 14 . As best seen in FIG. 5 , such advancement is limited by the ultimate abutment or engagement of a beveled seating surface 76 defined by the flange portion 50 of the seat member 40 against the complimentary valve seat 27 of the cushion 14 circumventing the valve opening 26 . Upon the engagement of the seating surface 76 to the valve seat 27 , the fluid chamber 22 of the cushion 14 fluidly communicates with the fluid conduit defined by the wall portion 46 of the seat member 40 . As will be recognized, if the diaphragm 44 resides in its normal, open position, the fluid chamber 22 is further placed into fluid communication with the valve chamber 59 via the fluid conduit defined by the wall portion 46 , neither end of which is blocked or obstructed by virtue of the gap defined between the lip 72 of the diaphragm 44 and the seating surface 49 of the wall portion 46 .
[0057] When the exhalation valve 12 is operatively coupled to the cushion 14 , in addition to the valve seat 27 being seated against the seating surface 76 , the first and second inner end surfaces 28 , 30 of the cushion 14 are seated against respective, diametrically opposed sections of the flange portion 68 defined by the cap member 42 . As best seen in FIGS. 3 and 4 , the orientation of the exhalation valve 12 relative to the cushion 14 is such that the end of the valve pilot lumen 38 extending to the second inner end surface 30 is aligned and fluidly communicates with the pilot port 74 within the flange portion 60 . As such, in the mask 10 , the valve pilot lumen 38 is in continuous, fluid communication with that portion of the valve chamber 59 defined between the inner surface 56 of the base portion 54 and the body portion 66 of the diaphragm 44 .
[0058] To assist in maintaining the cooperative engagement between the exhalation valve 12 and the cushion 14 , the mask 10 is further preferably provided with an elongate frame member 78 . The frame member 78 has a generally V-shaped configuration, with a central portion thereof being accommodated by and secured within the complimentary groove 64 formed in the outer surface 58 defined by the base portion 54 of the cap member 42 . As shown in FIGS. 3 and 4 , the opposed end portions of the frame members 78 are cooperatively engaged to respective ones of the first and second outer end surfaces 18 , 20 of the cushion 14 . More particularly, as shown in FIG. 2 , the frame member 78 includes an identically configured pair of first and second connectors 80 , 82 which extend from respective ones of the opposed end portions thereof. The first and second connectors 80 , 82 each define opposed inner and outer portions which have generally cylindrical, tubular configurations. The inner portion of the first connector 80 is advanced into and frictionally retained within the first gas delivery lumen 32 of the cushion 14 . Similarly, the inner portion of the second connector 82 is advanced into and frictionally retained within the second gas delivery lumen 34 of the cushion 14 . As will be described in more detail below, the outer portions of the first and second connectors 80 , 82 of the frame member 78 are each adapted to be advanced into and frictionally retained within a corresponding lumen of a respective one of a pair of bi-lumen tubes fluidly coupled to the mask 10 .
[0059] As shown in FIGS. 3 and 4 , the frame member 78 further includes a pressure port 84 which is disposed adjacent the first connector 80 . Like each of the first and second connectors 80 , 82 , the pressure port 84 defines opposed inner and outer portions which each have a generally cylindrical, tubular configuration. The inner portion of the pressure port 84 is aligned and fluidly communicates with the pressure sensing lumen 36 of the cushion 14 subsequent to being advanced and frictionally maintained therein. The frame member 78 is also provided with a pilot port 86 which is disposed adjacent the second connector 82 and also defines opposed inner and outer portions which each have a generally cylindrical, tubular configuration. The inner portion of the pilot port 86 is aligned and fluidly communicates with the valve pilot lumen 38 of the cushion 14 subsequent to being advanced and frictionally maintained therein. As will also be discussed in more detail below, the outer portions of the pressure and pilot ports 84 , 86 of the frame member 78 are adapted to be advanced into and frictionally maintained within corresponding lumens of respective ones of the aforementioned pair of bi-lumen tubes which are fluidly connected to the mask 10 within a ventilation system incorporating the same. The receipt of the frame member 78 within the groove 64 of the cap member 42 ensures that the cushion 14 , the exhalation valve 12 and the frame member 78 are properly aligned, and prevents relative movement therebetween. Though not shown, it is contemplated that in one potential variation of the mask 10 , the cushion 14 may be formed so as not to include the valve pilot lumen 38 . Rather, a suitable valve pilot lumen would be formed directly within the frame member 78 so as to extend therein between the pilot port 86 thereof and the pilot port 74 of the exhalation valve 12 .
[0060] In the mask 10 , the exhalation valve 12 is piloted, with the movement of the diaphragm 44 to the closed position described above being facilitated by the introduction of positive fluid pressure into the valve chamber 59 . More particularly, it is contemplated that during the inspiratory phase of the breathing cycle of a patient wearing the mask 10 , the valve pilot lumen 38 will be pressurized by a pilot line fluidly coupled to the pilot port 86 , with pilot pressure being introduced into that portion of the valve chamber 59 normally defined between the body portion 66 of the diaphragm 44 and the inner surface 56 defined by the base portion 54 of the cap member 42 via the pilot port 74 extending through the flange portion 60 of the cap member 42 . The fluid pressure level introduced into the aforementioned region of the valve chamber 59 via the pilot port 74 will be sufficient to facilitate the movement of the diaphragm 44 to its closed position described above.
[0061] Conversely, during the expiratory phase of the breathing cycle of the patient wearing the mask 10 , it is contemplated that the discontinuation or modulation of the fluid pressure through the valve pilot lumen 38 and hence into the aforementioned region of the valve chamber 59 via the pilot port 74 , coupled with the resiliency of the diaphragm 44 and/or positive pressure applied to the body portion 66 thereof, will facilitate the movement of the diaphragm 44 back to the open position or to a partially open position. In this regard, positive pressure as may be used to facilitate the movement of the diaphragm 44 to its open position may be provided by air which is exhaled from the patient during the expiratory phase of the breathing circuit and is applied to the body portion 66 via the pillows portions 24 of the cushion 14 , the fluid chamber 22 , and the fluid conduit defined by the wall portion of the seat member 40 . As will be recognized, the movement of the diaphragm 44 to the open position allows the air exhaled from the patient to be vented to ambient air after entering the valve chamber 59 via the exhaust vents 52 within the flange portion 50 of the seat member 40 which, as indicated above, fluidly communicate with the valve chamber 59 .
[0062] As will be recognized, based on the application of pilot pressure thereto, the diaphragm 44 travels from a fully open position through a partially open position to a fully closed position. In this regard, the diaphragm 44 will be partially open or partially closed during exhalation to maintain desired ventilation therapy. Further, when pilot pressure is discontinued to the diaphragm 44 , it moves to an open position wherein the patient can inhale and exhale through the mask 10 with minimal restriction and with minimal carbon dioxide retention therein. This is an important feature of the present invention which allows a patient to wear the mask 10 without ventilation therapy being applied to the mask 10 , the aforementioned structural and functional features of the mask 10 making it more comfortable to wear, and further allowing it to be worn without carbon dioxide buildup. This feature is highly advantageous for the treatment of obstructive sleep apnea wherein patients complain of discomfort with ventilation therapy due to mask and pressure discomfort. When it is detected that a patient requires sleep apnea therapy, the ventilation therapy can be started (i.e., in an obstructive sleep apnea situation).
[0063] To succinctly summarize the foregoing description of the structural and functional features of the mask 10 , during patient inhalation, the valve pilot lumen 38 is pressurized, which causes the diaphragm 44 to close against the seating surface 49 , thus effectively isolating the fluid chamber 22 of the mask 10 from the outside ambient air. The entire flow delivered from a flow generator fluidly coupled to the mask 10 is inhaled by the patient, assuming that unintentional leaks at the interface between the cushion 14 and the patient are discarded. This functionality differs from what typically occurs in a conventional CPAP mask, where venting to ambient air is constantly open, and an intentional leak flow is continuously expelled to ambient air. During patient exhalation, the pilot pressure introduced into the valve pilot lumen 38 is controlled so that the exhaled flow from the patient can be exhausted to ambient air through the exhalation valve 12 in the aforementioned manner. In this regard, the pilot pressure is “servoed” so that the position of the diaphragm 44 relative to the seating surface 49 is modulated, hence modulating the resistance of the exhalation valve 12 to the exhaled flow and effectively ensuring that the pressure in the fluid chamber 22 of the mask 10 is maintained at a prescribed therapeutic level throughout the entire length of the exhalation phase. When the valve pilot lumen 38 is not pressurized, the exhalation valve 12 is in a normally open state, with the diaphragm 44 being spaced from the seating surface 49 in the aforementioned manner, thus allowing the patient to spontaneously breathe in and out with minimal pressure drop (also referred to as back-pressure) in the order of less than about 2 cm H2O at 601/min. As a result, the patient can comfortably breathe while wearing the mask 10 and while therapy is not being administered to the patient.
[0064] Referring now to FIGS. 11A , 11 B and 11 C, during use of the mask 10 by a patient, the functionality of the exhalation valve 12 can be characterized with three parameters. These are Pt which is the treatment pressure (i.e., the pressure in the mask 10 used to treat the patient; Pp which is the pilot pressure (i.e., the pressure used to pilot the diaphragm 44 in the exhalation valve 12 ); and Qv which is vented flow (i.e., flow that is exhausted from inside the exhalation valve 12 to ambient. These three particular parameters are labeled as Pt, Pp and Qv in FIG. 9 . When the patient is ventilated, Pt is greater than zero, with the functionality of the exhalation valve 12 being described by the family of curves in the first and second quadrants of FIG. 11A . In this regard, as apparent from FIG. 11A , for any given Pt, it is evident that by increasing the pilot pressure Pp, the exhalation valve 12 will close and the vented flow will decrease. A decrease in the pilot pressure Pp will facilitate the opening of the valve 12 , thereby increasing vented flow. The vented flow will increase until the diaphragm 44 touches or contacts the inner surface 56 of the base portion 54 of the cap member 42 , and is thus not able to open further. Conversely, when the patient is not ventilated, the inspiratory phase can be described by the third and fourth quadrants. More particularly, Qv is negative and air enters the mask 10 through the valve 12 , with the pressure Pt in the mask 10 being less than or equal to zero. Pilot pressure Pp less than zero is not a configuration normally used during ventilation of the patient, but is depicted for a complete description of the functionality of the valve 12 . The family of curves shown in FIG. 11A can be described by a parametric equation. Further, the slope and asymptotes of the curves shown in FIG. 11A can be modified by, for example and not by way of limitation, changing the material used to fabricate the diaphragm 44 , changing the thickness of the diaphragm 44 , changing the area ratio between the pilot side and patient side of the diaphragm 44 , changing the clearance between the diaphragm 44 and the seating surface 49 , and/or changing the geometry of the exhaust vents 52 .
[0065] An alternative representation of the functional characteristics of the valve 12 can be described by graphs in which ΔP=Pt−Pp is shown. For example, the graph of FIG. 11B shows that for any given Pt, the vented flow can be modulated by changing ΔP. In this regard, ΔP can be interpreted as the physical position of the diaphragm 44 . Since the diaphragm 44 acts like a spring, the equation describing the relative position d of the diaphragm 44 from the seating surface 49 of the seat member 40 is k·d+Pt·At=Pp·Ap, where At is the area of the diaphragm 44 exposed to treatment pressure Pt and Ap is the area of the diaphragm 44 exposed to the pilot pressure Pp. A similar, alternative representation is provided in the graph of FIG. 11C which shows Pt on the x-axis and ΔP as the parameter. In this regard, for any given ΔP, the position d of the diaphragm 44 is determined, with the valve 12 thus being considered as a fixed opening valve. In this scenario Pt can be considered the driving pressure pushing air out of the valve 12 , with FIG. 11C further illustrating the highly non-linear behavior of the valve 12 .
[0066] FIG. 12 provides a schematic representation of an exemplary ventilation system 88 wherein a tri-lumen tube 90 is used to facilitate the fluid communication between the mask 10 and a blower or flow generator 92 of the system 88 . As represented in FIG. 12 , one end of the tri-lumen tube 90 is fluidly connected to the flow generator 92 , with the opposite end thereof being fluidly connected to a Y-connector 94 . The three lumens defined by the tri-lumen tube 90 include a gas delivery lumen, a pressure sensing lumen, and a valve pilot lumen. The gas delivery lumen is provided with an inner diameter or ID in the range of from about 2 mm to 15 mm, and preferably about 4 mm to 10 mm. The pressure sensing and valve pilot lumens of the tri-lumen tube 90 are each preferably provided with an ID in the range of from about 0.5 mm to 2 mm. The outer diameter or OD of the tri-lumen tube 90 is preferably less than about 17 mm, with the length thereof in the system 88 being about 1.8 m or 6 ft. The Y-connector 94 effectively bifurcates the tri-lumen tube 90 into the first and second bi-lumen tubes 96 , 98 , each of which has a length of about 24 inches. The first bi-lumen tube 96 includes a gas delivery lumen having an ID in the range of from about 1 mm to 10 mm, and preferably about 3 mm to 6 mm. The gas delivery lumen of the first bi-lumen tube 96 is fluidly coupled to the outer portion of the first connector 80 of the frame member 78 . The remaining lumen of the first bi-lumen tube 96 is a pressure sensing lumen which has an ID in the same range described above in relation to the pressure sensing lumen of the tri-lumen tube 90 , and is fluidly coupled to the pressure port 84 of the frame member 78 . Similarly, the second bi-lumen tube 98 includes a gas delivery lumen having an ID in the range of from about 1 mm to 10 mm, and preferably about 3 mm to 6 mm. The gas delivery lumen of the second bi-lumen tube 98 is fluidly coupled to the outer portion of the second connector 82 of the frame member 78 . The remaining lumen of the second bi-lumen tube 98 is a valve pilot lumen which has an ID in the same range described above in relation to the valve pilot lumen of the tri-lumen tube 90 , and is fluidly coupled to the pilot port 86 of the frame member 78 .
[0067] In the system 88 shown in FIG. 12 , the pilot pressure is generated at the flow generator 92 . In the prior art, a secondary blower or proportional valve that modulates the pressure from a main blower is used to generate a pressure to drive an expiratory valve. However, in the system 88 shown in FIG. 12 , the outlet pressure of the flow generator 92 is used, with the flow generator 92 further being controlled during patient exhalation in order to have the correct pilot pressure for the exhalation valve 12 . This allows the system 88 to be inexpensive, not needing additional expensive components such as proportional valves or secondary blowers.
[0068] FIG. 13 provides a schematic representation of another exemplary ventilation system 100 wherein a bi-lumen tube 102 is used to facilitate the fluid communication between the mask 10 and the blower or flow generator 92 of the system 100 . As represented in FIG. 13 , one end of the bi-lumen tube 102 is fluidly connected to the flow generator 92 , with the opposite end thereof being fluidly connected to the Y-connector 94 . The two lumens defined by the bi-lumen tube 102 include a gas delivery lumen and a pressure sensing lumen. The gas delivery lumen is provided with an inner diameter or ID in the range of from about 2 mm to 10 mm, and preferably about 4 mm to 7 mm. The pressure sensing lumen of the bi-lumen tube 102 is preferably provided with an ID in the range of from about 0.5 mm to 2 mm. The outer diameter or OD of the bi-lumen tube 90 is preferably less than about 11 mm, with the length thereof being about 1.8 m or 6 ft. The Y-connector 94 effectively bifurcates the bi-lumen tube 102 into the first and second bi-lumen tubes 96 , 98 , each of which has a length of about 24 inches. The first bi-lumen tube 96 includes a gas delivery lumen having an ID in the range of from about 1 mm to 10 mm, and preferably about 3 mm to 6 mm. The gas delivery lumen of the first bi-lumen tube 96 is fluidly coupled to the outer portion of the first connector 80 of the frame member 78 . The remaining lumen of the first bi-lumen tube 96 is a pressure sensing lumen which has an ID in the same range described above in relation to the pressure sensing lumen of the bi-lumen tube 102 , and is fluidly coupled to the pressure port 84 of the frame member 78 . Similarly, the second bi-lumen tube 98 includes a gas delivery lumen having an ID in the range of from about 1 mm to 10 mm, and preferably about 3 mm to 6 mm. The gas delivery lumen of the second bi-lumen tube 98 is fluidly coupled to the outer portion of the second connector 82 of the frame member 78 . The remaining lumen of the second bi-lumen tube 98 is a valve pilot lumen which has an ID in the same range described above in relation to the pressure sensing lumen of the bi-lumen tube 102 , and is fluidly coupled to the pilot port 86 of the frame member 78 .
[0069] In the system 100 shown in FIG. 13 , the valve pilot lumen 38 is connected to the gas delivery air path at the Y-connector 94 . More particularly, the gas delivery lumen of the bi-lumen tube 102 is transitioned at the Y-connector 94 to the valve pilot lumen of the second bi-lumen tube 98 . As such, the pilot pressure will be proportional to the outlet pressure of the flow generator 92 minus the pressure drop along the bi-lumen tube 102 , which is proportional to delivered flow. This solution is useful when small diameter tubes are used in the system 100 , since such small diameter tubes require higher outlet pressure from the flow generator 92 for the same flow. In this regard, since the pressure at the outlet of the flow generator 92 would be excessive for piloting the exhalation valve 12 , a lower pressure along the circuit within the system 100 is used. In the system 100 , though it is easier to tap in at the Y-connector 94 , anywhere along the tube network is acceptable, depending on the pressure level of the flow generator 92 which is the pressure required by the patient circuit in order to deliver the therapeutic pressure and flow at the patient.
[0070] In each of the systems 88 , 100 , it is contemplated that the control of the flow generator 92 , and hence the control of therapeutic pressure delivered to the patient wearing the mask 10 , may be governed by the data gathered from dual pressure sensors which take measurements at the mask 10 and the output of the flow generator 92 . As will be recognized, pressure sensing at the mask 10 is facilitated by the pressure sensing lumen 36 which, as indicated above, is formed within the cushion 14 and fluidly communicates with the fluid chamber 22 thereof. As also previously explained, one of the lumens of the first bi-lumen tube 96 in each of the systems 88 , 100 is coupled to the pressure port 84 (and hence the pressure sensing lumen 36 ). As a result, the first bi-lumen tube 96 , Y-connector 94 and one of the tri-lumen or bi-lumen tubes 90 , 102 collectively define a continuous pressure sensing fluid path between the mask 10 and a suitable pressure sensing modality located remotely therefrom. A more detailed discussion regarding the use of the dual pressure sensors to govern the delivery of therapeutic pressure to the patient is found in Applicant's co-pending U.S. application Ser. No. 13/411,257 entitled Dual Pressure Sensor Continuous Positive Airway Pressure (CPAP) Therapy filed Mar. 2, 2012, the entire disclosure of which is incorporated herein by reference.
[0071] Referring now to FIG. 10 , there is shown a mask 10 a which comprises a variant of the mask 10 . The sole distinction between the masks 10 , 10 a lies in the mask 10 a including a heat and moisture exchanger or HME 104 which is positioned within the fluid chamber 22 of the cushion 14 . The HME 104 is operative to partially or completely replace a humidifier (cold or heated pass-over; active or passive) which would otherwise be fluidly coupled to the mask 10 a. This is possible because the average flow through the system envisioned to be used in conjunction with the mask 10 a is about half of a prior art CPAP mask, due to the absence of any intentional leak in such system.
[0072] The HME 104 as a result of its positioning within the fluid chamber 22 , is able to intercept the flow delivered from the flow generator to the patient in order to humidify it, and is further able to capture humidity and heat from exhaled flow for the next breath. The pressure drop created by the HME 104 during exhalation (back-pressure) must be limited, in the order of less than 5 cmH2O at 601/min, and preferably lower than 2 cmH2O at 601/min. These parameters allow for a low back-pressure when the patient is wearing the mask 10 a and no therapy is delivered to the patient.
[0073] It is contemplated that the HME 104 can be permanently assembled to the cushion 14 , or may alternatively be removable therefrom and thus washable and/or disposable. In this regard, the HME 104 , if removable from within the cushion 14 , could be replaced on a prescribed replacement cycle. Additionally, it is contemplated that the HME 104 can be used as an elastic member that adds elasticity to the cushion 14 . In this regard, part of the elasticity of the cushion 14 may be attributable to its silicone construction, and further be partly attributable to the compression and deflection of the HME 104 inside the cushion 14 .
[0074] The integration of the exhalation valve 12 into the cushion 14 and in accordance with the present invention allows lower average flow compared to prior art CPAP masks. As indicated above, normal masks have a set of apertures called “vents” that create a continuous intentional leak during therapy. This intentional leak or vented flow is used to flush out the exhaled carbon dioxide that in conventional CPAP machines, with a standard ISO taper tube connecting the mask to the flow generator or blower, fills the tubing up almost completely with carbon dioxide during exhalation. The carbon dioxide accumulated in the tubing, if not flushed out through the vent flow, would be inhaled by the patient in the next breath, progressively increasing the carbon dioxide content in the inhaled gas at every breath. The structural/functional features of the exhalation valve 12 , in conjunction with the use of small inner diameter, high pneumatic resistance tubes in the system in which the mask 10 , 10 a is used, ensures that all the exhaled gas goes to ambient. As a result, a vent flow is not needed for flushing any trapped carbon dioxide out of the system. Further, during inspiration the exhalation valve 12 can close, and the flow generator of the system needs to deliver only the patient flow, without the additional overhead of the intentional leak flow. In turn, the need for lower flow rates allows for the use of smaller tubes that have higher pneumatic resistance, without the need for the use of extremely powerful flow generators. The pneumatic power through the system can be kept comparable to those of traditional CPAP machines, though the pressure delivered by the flow generator will be higher and the flow lower.
[0075] The reduced average flow through the system in which the mask 10 , 10 a is used means that less humidity will be removed from the system, as well as the patient. Conventional CPAP systems have to reintegrate the humidity vented by the intentional leak using a humidifier, with heated humidifiers being the industry standard. Active humidification introduces additional problems such as rain-out in the system tubing, which in turn requires heated tubes, and thus introducing more complexity and cost into the system. The envisioned system of the prent invention, as not having any intentional leak flow, does not need to introduce additional humidity into the system. As indicated above, the HME 104 can be introduced into the cushion 14 of the mask 10 a so that exhaled humidity can be trapped and used to humidify the air for the following breath.
[0076] In addition, a big portion of the noise of conventional CPAP systems is noise conducted from the flow generator through the tubing up to the mask and then radiated in the ambient through the vent openings. As previously explained, the system described above is closed to the ambient during inhalation which is the noisiest part of the therapy. The exhaled flow is also lower than the prior art so it can be diffused more efficiently, thus effectively decreasing the average exit speed and minimizing impingement noise of the exhaled flow on bed sheets, pillows, etc.
[0077] As also explained above, a patient can breathe spontaneously when the mask is worn and not connected to the flow generator tubing, or when therapy is not administered. In this regard, there will be little back pressure and virtually no carbon dioxide re-breathing, due to the presence of the exhalation valve 12 that is normally open and the inner diameters of the tubes integrated into the system. This enables a zero pressure start wherein the patient falls asleep wearing the mask 10 , 10 a wherein the flow generator does not deliver any therapy. Prior art systems can only ramp from about 4 mH2O up to therapy pressure. A zero pressure start is more comfortable to patients that do not tolerate pressure.
[0078] As seen in FIG. 14 , due to the reduced diameter of the various tubes (i.e., the tri-lumen tube 90 and bi-lumen tubes 96 , 98 , 102 ) integrated into the system 88 , 100 , such tubes can be routed around the patient's ears similar to conventional O2 cannulas. More particularly, the tubing can go around the patient's ears to hold the mask 10 , 10 a to the patient's face. This removes the “tube drag” problem described above since the tubes will not pull the mask 10 , 10 a away from the face of the patient when he or she moves. As previously explained, “tube drag” typically decreases mask stability on the patient and increases unintentional leak that annoys the patient. In the prior art, head gear tension is used to counter balance the tube drag, which leads to comfort issues. The tube routing of the present invention allows for lower head gear tension and a more comfortable therapy, especially for compliant patients that wear the mask 10 approximately eight hours every night. The reduction in tube drag in accordance with the present invention also allows for minimal headgear design (virtually none), reduced headgear tension for better patient comfort as indicated above, and reduced cushion compliance that results in a smaller, more discrete cushion 14 . The tube dangling in front of the patient, also commonly referred to as the “elephant trunk” by patients, is a substantial psychological barrier to getting used to therapy. The tube routing shown in FIG. 14 , in addition to making the mask 10 , 10 a more stable upon the patient, avoids this barrier as well. Another benefit to the smaller tubing is that the mask 10 , 10 a can become smaller because it does not need to interface with large tubing. Indeed, large masks are another significant factor leading to the high non-compliance rate for CPAP therapy since, in addition to being non-discrete, they often cause claustrophobia.
[0079] Referring now to FIG. 15 , there is shown a front-elevational view of the nasal pillows mask 10 , 10 a of the present invention wherein an exemplary tri-lumen tube 90 , Y-connector 94 , and pair of bi-lumen tubes 96 , 98 are used to collectively facilitate the operative interface between the nasal pillows mask 10 , 10 a and a flow generating device 92 in accordance with the schematic representation of the ventilation system 88 shown in FIG. 12 . As indicated above, in the ventilation system 88 , the tri-lumen tube 90 is used to facilitate the fluid communication between the Y-connector 94 and the blower or flow generator 92 of the system 88 , with one end of the tri-lumen tube 90 being fluidly connected to the flow generator 92 , and the opposite end thereof being fluidly connected to the Y-connector 94 .
[0080] As is best seen in FIGS. 16 , 20 and 21 , the tri-lumen tube 90 has a ribbon-like, generally elliptical or oval cross-sectional configuration, and defines three (3) lumens, along with a lengthwise cross-sectional axis A 1 and a widthwise cross-sectional axis A 2 , both of which are shown in FIG. 20 . More particularly, the tri-lumen tube 90 includes a gas delivery lumen 104 , a pressure sensing lumen 106 , and a pilot lumen 108 . As best seen in FIG. 20 , like the tri-lumen tube 90 , the gas delivery lumen 104 has a generally elliptical profile or cross-sectional configuration. Along these lines, the gas delivery lumen 104 is preferably formed so as to have a maximum length L in the range of from about 5 ft. to 10 ft., and preferably about 6 ft.; a maximum width W in the range of from about 8 mm to 13 mm; and a cross-sectional area equivalent to a circular lumen with a diameter of about 2 mm to 15 mm, and preferably about 4 mm to 10 mm, and most preferably about 8 mm. The pressure sensing and pilot lumens 106 , 108 are disposed proximate respective ones of the ends of the gas delivery lumen 104 along the axis A 1 . However, both the pressure sensing and pilot lumens 106 , 108 each have a generally circular cross-sectional configuration, as opposed to an elliptical cross-sectional configuration. As is further apparent from FIGS. 16 , 20 and 21 , the cross-sectional area of the gas delivery lumen 104 substantially exceeds that of each of the pressure sensing and pilot lumens 106 , 108 , which are preferably identically sized to each other, and are each provided with an inner diameter or ID in the range of from about 0.5 mm to 2 mm. The tri-lumen tube 90 is preferably fabricated from a silicone, TPE or PVC material which has a Shore Hardness in the range of from about 50 A to 80 A, and thus possesses a prescribed level of resilience and flexibility.
[0081] The structural features of the tri-lumen tube 90 , coupled with the material properties thereof, are selected to not only make it resiliently flexible, but to prevent either of the pressure sensing or pilot lumens 106 , 108 from being collapsed by even an above-normal level of bending, twisting or other deflection of the tri-lumen tube 90 . In this regard, the elliptical cross-sectional configurations of the tri-lumen tube 90 and its gas delivery lumen 104 , coupled with the orientation of the pressure sensing and pilot lumens 106 , 108 adjacent respective ones of the opposed ends thereof (along of the lengthwise cross-sectional axis A 1 ), imparts to the tri-lumen tube 90 a tendency to bend in a direction which is generally perpendicular to, rather than aligned with or parallel to the axis A 1 (similar to the bending of a ribbon). This manner of bending, which is generally along the axis A 2 , substantially reduces the susceptibility of the pressure sensing or pilot lumens 106 , 108 to inadvertent collapse. Thus, even if the tri-lumen tube 90 is bent beyond that threshold which would typically be encountered during normal use of ventilation system 88 as could result in the collapse or blockage of the gas delivery lumen 104 , flow will typically still be maintained through both the pressure sensing and pilot lumens 106 , 108 . This unobstructed fluid or pneumatic communication through the pressure sensing and pilot lumens 106 , 108 provides a modality which, in concert with the control algorithms of the ventilation system 88 , may be used to facilitate not only the actuation of the exhalation valve 12 in a manner ensuring unhindered patient breathing through the mask 10 , 10 a, but also the sounding of an alarm within the ventilation system 88 and/or adjustment to other operational parameters thereof as are necessary to address the blockage or obstruction of the gas delivery lumen 104 .
[0082] As indicated above, the structural attributes of the Y-connector 94 , which will be described in more detail below, effectively bifurcates the tri-lumen tube 90 into the first and second bi-lumen tubes 96 , 98 , each of which is of a prescribed length. As best seen in FIGS. 19 , 22 and 23 , the first and second bi-lumen tubes 96 , 98 are identically configured to each other, and each have a generally tear-drop shaped cross-sectional configuration defining an apex 118 . The first bi-lumen tube 96 includes a gas delivery lumen 110 and a pressure sensing lumen 112 . Similarly, the second bi-lumen to 98 includes a gas delivery lumen 114 and a pilot lumen 116 .
[0083] In both the first and second bi-lumen tubes 96 , 98 , the gas delivery lumens 110 , 114 each have a generally elliptical cross-sectional configuration or profile, as is most easily seen in FIG. 19 . The elliptical cross-sectional area is equivalent to that of a circular lumen having a diameter in the range of from about 1 mm to 10 mm, and preferably about 3 mm to 6 mm, and most preferably about 5 mm. However, the pressure sensing and pilot lumens 112 , 116 each have a generally circular cross-sectional configuration or profile, with an inner diameter or ID in the range of from about 0.5 mm to 2 mm. Each bi-lumen tube 96 , 98 is preferably fabricated from a silicone, TPE or PVC material which has a Shore Hardness in the range of from about 50 A to 80 A, and thus possesses a prescribed level of resilience and flexibility. The advantages attendant to forming each of the gas delivery lumens 110 , 114 of the first and second bi-lumen tubes 96 , 98 with a generally elliptical profile will be discussed more detail below.
[0084] In the exemplary ventilation system 88 , the gas delivery lumen 110 of the first bi-lumen tube 96 is fluidly coupled to the generally cylindrical, tubular outer portion of the first connector 80 of the frame number 78 . The pressure sensing lumen 112 of the first bi-lumen tube 96 is itself fluidly coupled to the generally cylindrical, tubular outer portion of the pressure port 84 of the frame number 78 which, as indicated above, is disposed immediately adjacent the outer portion of the first connector 80 . As will be recognized, the pressure sensing lumen 112 is sized relative to the outer portion of the pressure port 84 such that the pressure port 84 is frictionally maintained within the first bi-lumen tube 96 once advanced into a corresponding end of the pressure sensing lumen 112 thereof. Similarly, the gas delivery lumen 110 is sized relative to the outer portion of the first connector 80 such that the first connector 80 is frictionally retained within the first bi-lumen tube 96 once advanced into a corresponding end of the gas delivery lumen 110 .
[0085] Similar to the first bi-lumen tube 96 , the gas delivery lumen 114 of the second bi-lumen tube 98 is fluidly coupled to the generally cylindrical, tubular outer portion of the second connector 82 of the frame number 78 . The pilot lumen 116 of the second bi-lumen tube 98 is itself fluidly coupled to the generally cylindrical, tubular outer portion of the pilot port 86 of the frame number 78 which, as indicated above, is disposed immediately adjacent the outer portion of the second connector 80 . As will be recognized, the pilot lumen 116 is sized relative to the outer portion of the pilot port 86 such that the pilot port 86 is frictionally maintained within the second bi-lumen tube 98 once advanced into a corresponding end of the pilot lumen 116 thereof. Similarly, the gas delivery lumen 114 is sized relative to the outer portion of the second connector 82 such that the second connector 82 is frictionally retained within the second bi-lumen tube 98 once advanced into a corresponding end of the gas delivery lumen 114 .
[0086] As seen in FIG. 22 , whereas the outer portion of each of the first and second connectors 80 , 82 has a generally circular cross-sectional configuration, the gas delivery lumens 110 , 114 of the first and second bi-lumen tubes 96 , 98 each have a generally elliptical cross-sectional configuration or profile as indicated above. In the ventilation system 88 , the relative orientations of the outer portions of the first connector 80 and pressure port 84 are the same as those of the outer portions of second connector 82 and pilot port 86 . Similarly, the relative orientations of the gas delivery and pressure sensing lumens 110 , 112 of the first bi-lumen tube 96 are the same as the gas delivery and pilot lumens 114 , 116 of the second bi-lumen tube 98 . In the ventilation system 88 , these relative orientations are specifically selected so as to achieve a prescribed offset between the axis of the outer portions of the first and second connectors 80 , 82 and corresponding ones of the gas delivery lumens 110 , 114 when the outer portions of the pressure and pilot ports 80 , 82 are coaxially aligned with respective ones of the pressure sensing and pilot lumens 112 , 116 of the first and second bi-lumen tubes 96 , 98 . As a result of these offsets, the advancement of the outer portions of the first and second connectors 80 , 82 into corresponding ends of respective ones of the gas delivery lumens 110 , 114 facilitates the resilient deformation of each of the first and second bi-lumen tubes 96 , 98 in a matter effectively compressing a web portion 120 thereof. As seen in FIGS. 19 , 22 and 23 , this web portion 120 is disposed between the gas delivery lumen 110 , 114 and a corresponding one the pressure sensing and pilot lumens 112 , 116 . Such compression of the web portion 120 effectively maintains a tight frictional engagement between the first and second bi-lumen tubes 96 , 98 and the outer portions of respective ones of the first and second connectors 80 , 82 which is less prone to leakage.
[0087] The structural features of the first and second bi-lumen tubes 96 , 98 , coupled with the material properties thereof, are selected to not only to provide resilient flexibility, but to prevent either of the pressure sensing or pilot lumens 112 , 116 from being collapsed by even an above-normal level of bending, twisting or other deflection of the corresponding bi-lumen tube 96 , 98 . In this regard, the elliptical or tear drop shaped cross-sectional configuration of each bi-lumen tube 96 , 98 , coupled with the orientation of the corresponding pressure sensing or pilot lumen 112 , 116 between the gas delivery lumen 110 , 114 and the apex 118 thereof, substantially reduces the susceptibility of the pressure sensing or pilot lumens 112 , 116 to inadvertent collapse. Thus, even if the first or second bi-lumen tube 96 , 98 is bent beyond that threshold which would typically be encountered during normal use of ventilation system 88 as could result in the collapse or blockage of the corresponding gas delivery lumen 110 , 114 , flow will typically still be maintained through both the pressure sensing and pilot lumens 112 , 116 . As with the tri-lumen tube 90 described above, this unobstructed flow through the pressure sensing and pilot lumens 112 , 116 provides a modality which, in concert with the control algorithms of the ventilation system 88 , may be used to facilitate not only the actuation of the exhalation valve 12 in a manner ensuring unhindered patient breathing through the mask 10 , 10 a, but also the sounding of an alarm within the ventilation system 88 and/or adjustment to other operational parameters thereof as are necessary to address the blockage or obstruction of either gas delivery lumen 110 , 114 .
[0088] Referring now to FIGS. 15-18 and 21 , as indicated above, in the ventilation system 88 the Y-connector 94 facilitates the operative interface between the tri-lumen tube 90 and the first and second bi-lumen tubes 96 , 98 . More particularly, the Y-connector 94 effectively divides the gas delivery lumen 104 of the tri-lumen tube 90 into the gas delivery lumens 110 , 114 of the first and second bi-lumen tubes 96 , 98 .
[0089] Advantageously, the Y-connector 94 is adapted to allow for the selective disconnection or de-coupling of the tri-lumen tube 90 from the first and second bi-lumen tubes 96 , 98 without disconnecting or separating either the tri-lumen tube 90 or either of the first and second bi-lumen tubes 96 , 98 from the Y-connector 94 . In this regard, the Y-connector 94 comprises a male member 118 and a complimentary female member 120 which are releasably engageable to each other. The male member 118 includes a base portion 122 which has a generally elliptical or oval-shaped cross-sectional configuration. In this regard, the cross-sectional length and width dimensions of the base portion 122 along the lengthwise and widthwise major axes thereof are preferably equal or substantially equal to those of the tri-lumen tube 90 .
[0090] In addition to the base portion 122 , the male member 118 includes first and second tube portions 124 , 126 which protrude from respective ones of the opposed sides or faces of the base portion 122 . Like the base portion 122 , the first and second tube portions 124 , 126 each have a generally elliptical or oval-shaped cross-sectional configuration. The height of the first tube portion 124 exceeds that of the second tube portion 126 . Additionally, the cross-sectional length and width dimensions of the second tube portion 126 are sized so as to slightly exceed those of the gas delivery lumen 104 of the tri-lumen tube 90 . Such relative sizing is selected such that the second tube portion 126 may be advanced into yet tightly frictionally maintained within one end of the gas delivery lumen 104 . The advancement of the second tube portion 126 into the gas delivery lumen 104 is typically limited by the abutment of the corresponding end of the tri-lumen tube 90 against that end or face of the base portion 122 having the second tube portion 126 protruding therefrom. As will be recognized, due to the maximum cross-sectional length and width dimensions of the base portion 122 preferably being equal or substantially equal to those of the tri-lumen tube 90 , the outer surface of the base portion 122 will be substantially flush or continuous with the outer surface of the tri-lumen tube 90 when the corresponding ends are abutted against each other in the aforementioned manner. In the male member 118 , the base portion 122 and the first and second tube portions 124 , 126 collectively define a gas delivery lumen 128 which is most easily seen in FIG. 21 .
[0091] The male member 118 further comprises first and second pressure sensing ports 130 , 132 which protrude from respective ones of the opposed sides or faces of the base portion 122 , and first and second pilot ports 134 , 136 which also protrude from respective ones of the opposed sides or faces of the base portion 122 . In this regard, the first and second pressure sensing ports 130 , 132 are coaxially aligned with each other, as are the first and second pilot ports 134 , 136 .
[0092] In the male member 118 , the first pressure sensing and pilot ports 130 , 134 are identically configured to each other, with the second pressure sensing and pilot ports 132 , 136 being identically configured to each other as well. Though the first and second pressure sensing ports 130 , 132 and the first and second pilot ports 134 , 136 each have tubular, generally cylindrical configurations with generally circular cross-sectional profiles, the outer diameters of the first pressure sensing and pilot ports 130 , 134 exceed those of the second pressure sensing and pilot ports 132 , 136 . As is best seen in FIG. 21 , the first and second pressure sensing ports 130 , 132 and the base portion 122 collectively define a pressure sensing lumen 138 of the male member 118 . Similarly, the first and second pilot lumens 134 , 136 and the base portion 122 collectively define a pilot lumen 140 of the male member 118 .
[0093] As is most apparent from FIG. 16 , the first pressure sensing and pilot ports 130 , 134 are oriented so as to be disposed adjacent respective ones of the opposed ends of the first tube portion 124 along the lengthwise cross-sectional axis thereof. Similarly, the second pressure sensing and pilot ports 132 , 136 are positioned adjacent respective ones of the opposed ends of the second tube portion 126 along the lengthwise cross-sectional axis thereof. Importantly, the orientation of the second pressure sensing and pilot lumens 132 , 136 relative to the second tube portion 126 is such that when the second tube portion 126 is coaxially aligned with the gas delivery lumen 104 of the tri-lumen tube 90 , the second pressure sensing and pilot ports 132 , 136 will be coaxially aligned with respective ones of the pressure sensing and pilot lumens 106 , 108 of the tri-lumen tube 90 . As such, when the second tube portion 126 is advanced into the gas delivery lumen 104 in the aforementioned manner, the second sensing port 132 will concurrently be advanced into one end of the pressure sensing lumen 106 , with the second pilot port 136 being concurrently advanced into one end of the pilot lumen 108 . Along these lines, the outer diameter dimensions of the second pressure sensing and pilot ports 132 , 136 are preferably sized relative to the inner diameter dimensions of the pressure sensing and pilot lumens 106 , 108 such that the second pressure sensing and pilot ports 132 , 136 are tightly frictionally retained within respective ones of the pressure sensing and pilot lumens 106 , 108 upon being fully advanced therein.
[0094] As is best seen in FIGS. 16-18 , the male member 118 further includes an opposed, juxtaposed pair of locking tabs 142 which protrude from the base portion 122 and extend along the first tube portion 124 . More particularly, the locking tabs 142 are positioned on opposite sides of the first tube portion 124 so as to extend in generally perpendicular relation to the widthwise cross-sectional axis thereof. As will be described in more detail below, the locking tabs 142 are used to facilitate the releasable engagement of the male member 118 to the female member 120 . As will also be described in more detail below, the locking tabs 142 may be identically configured to each other, or may alternatively have dissimilar configurations for purposes of insuring that the male and female members 118 , 120 are in prescribed orientations relative to each other as a precursor to being releasably engaged to each other.
[0095] The female member 120 of the Y-connector 94 comprises a main body portion 144 which itself has a generally elliptical or oval-shaped cross-sectional configuration. In this regard, the cross-sectional length and width dimensions of the body portion 144 along the lengthwise and widthwise major axes thereof are preferably equal or substantially equal to those of the base portion 122 of the male member 118 , as well as the tri-lumen tube 90 . As best seen in FIGS. 17 and 21 , the body portion 144 defines an elongate passage 146 which extends generally axially therein to one of the opposed sides or faces thereof.
[0096] In addition to the body portion 144 , the female member 120 includes an identically configured pair of first and second gas delivery ports 148 , 150 which protrude from a common side or face of the body portion 144 , and in particular that side opposite the side having the passage 146 extending thereto. The first and second gas delivery ports 148 , 150 each have a tubular, generally cylindrical configuration with a generally circular cross-sectional profile. Additionally, the first and second gas delivery ports 148 , 150 each fluidly communicate with one end of the passage 146 .
[0097] The female member 120 further comprises a pressure sensing port 152 and a pilot port 154 which are identically configured to each other, and protrude from that side or face of the body portion 144 having the first and second gas delivery ports 148 , 50 protruding therefrom. More particularly, the pressure sensing port 152 is disposed between the first gas delivery port 148 and one of the opposed ends of the body portion 144 along the lengthwise cross-sectional axis thereof. Similarly, the pilot port 154 is disposed between the second gas delivery port 150 and one of the opposed ends of the body portion 144 along the lengthwise cross-sectional axis thereof. The pressure sensing and pilot ports 152 , 154 also each have a tubular, generally cylindrical configuration with a generally circular cross-sectional profile. As is best seen in FIG. 21 , the pressure sensing port 152 and the body portion 144 collectively define a pressure sensing lumen 156 of the female member 120 . Similarly, the pilot port 154 and the body portion 144 collectively define a pilot lumen 158 of the female member 120 .
[0098] The first gas delivery port 148 of the female member 120 is adapted to be advanced into one end of the gas delivery lumen 110 of the first bi-lumen tube 96 , with the second gas delivery port 150 being adapted for advancement into one end of the gas delivery lumen 114 of the second bi-lumen tube 98 . However, whereas the first and second gas delivery ports 148 , 150 each have a generally circular cross-sectional configuration, the gas delivery lumens 110 , 114 of the first and second bi-lumen tubes 96 , 98 each have the generally elliptical cross-sectional configuration or profile as indicated above. In the ventilation system 88 , the relative orientations of the first gas delivery port 148 and the pressure sensing port 152 are the same as those of the first connector 80 and pressure port 84 of the mask 10 , 10 a. Similarly, the relative orientations of the second gas delivery port 150 and pilot port 154 are the same as those of the second connector 82 and pilot port 86 of the mask 10 , 10 a. As with the connection of the first and second bi-lumen tubes 96 , 98 to the mask 10 , 10 a as explained above, these relative orientations are specifically selected so as to achieve a prescribed offset between the axes of the first and second gas delivery ports 148 , 150 and corresponding ones of the gas delivery lumens 110 , 114 when the pressure sensing port 152 is coaxially aligned with the pressure sensing lumen 112 of the first bi-lumen tube 96 , and the pilot port 154 is coaxially aligned with the pilot lumen 116 of the second bi-lumen tube 98 . As a result of these offsets, the advancement of the first and second gas delivery ports 148 , 150 into corresponding ends of respective ones of the gas delivery lumens 110 , 114 facilitates the resilient deformation of each of the first and second bi-lumen tubes 96 , 98 in a manner effectively compressing the web portion 120 thereof. Such compression of the web portion 120 effectively maintains a tight frictional engagement between the first and second bi-lumen tubes 96 , 98 and respective ones of the first and second gas delivery ports 148 , 150 which is less prone to leakage.
[0099] The advancement of the first gas delivery port 148 into the gas delivery lumen 110 , as well as the advancement of the second gas delivery port 150 into the gas delivery lumen 114 , is limited by the abutment of the corresponding ends of the first and second bi-lumen tubes 96 , 98 against that end or face of the body portion 144 having the first and second gas delivery ports 148 , 150 , as well as the pressure sensing and pilot ports 152 , 154 , protruding therefrom. As will be recognized, when the first gas delivery port 148 is advanced into the gas delivery lumen 110 in the aforementioned manner, the pressure sensing port 152 is concurrently advanced into one end of the pressure sensing lumen 112 . Similarly, when the second gas delivery port 150 is advanced into the gas delivery lumen 114 , the pilot port 154 will concurrently be advanced into one end of the pilot lumen 116 . Along these lines, the outer diameter dimensions of the pressure sensing and pilot ports 152 , 154 are preferably sized relative to the inner diameter dimensions of the pressure sensing and pilot lumens 112 , 116 such that the pressure sensing and pilot ports 152 , 154 are tightly frictionally retained within respective ones of the pressure sensing and pilot lumens 112 , 116 upon being fully advanced therein.
[0100] As best seen in FIGS. 16 and 17 , the female member 120 further includes an opposed pair of retention tabs 160 which are formed in and extend partially along the body portion 144 . More particularly, the retention tabs 160 are positioned on opposite sides of the body portion 144 so as to extend in generally perpendicular relation to the widthwise cross-sectional axis thereof. As will also be described in more detail below, the retention tabs 160 are sized and configured to be releasably engageable to respective ones of the locking tabs 142 to facilitate the releasable engagement of the male member 118 to female member 120 . As with the locking tabs 142 , the retention tabs 160 may be identically configured to each other, or may alternatively have dissimilar configurations for purposes of ensuring that that the male and female members 118 , 120 are in prescribed orientations relative to each other as a precursor to being releasably engaged to each other.
[0101] In FIGS. 16-18 , the male and female members 118 , 120 of the Y-connector 124 are depicted in a disconnected or separated state. When the male member 118 is disconnected from the female member 120 , the gas delivery lumens 110 , 114 of the first and second bi-lumen tubes 96 , 98 each still fluidly communicate with the passage 146 of the female member 120 via respective ones of the first and second gas delivery ports 148 , 150 . In addition, the pressure sensing lumen 112 of the first bi-lumen tube 96 still fluidly communicates with the pressure sensing lumen 156 , with the pilot lumen 116 of the second bi-lumen tube 98 still fluidly communicating with the pilot lumen 158 . Further, the gas delivery lumen 128 of the male member 118 still fluidly communicates with the gas delivery lumen 104 of the tri-lumen tube 90 via the second tube portion 126 , with the pressure sensing lumen 138 still fluidly communicating with the pressure sensing lumen 106 and the pilot lumen 140 still fluidly communicating with the pilot lumen 108 .
[0102] The connection of the male and female members 118 , 120 to each other is facilitated by initially advancing both the first tube portion 124 and the locking tabs 142 of the male member 118 into the passage 146 of the female member 120 which has a complementary shape adapted to accommodate both the first tube portion 124 and the locking tabs 142 . The orientation of the first pressure sensing and pilot ports 130 , 134 of the male member 118 relative to the first tube portion 124 is such that the coaxial alignment of the first tube portion 124 with the passage 146 facilitates the concurrent coaxial alignment of the first pressure sensing port 130 with the pressure sensing lumen 156 and the coaxial alignment of the first pressure sensing port 134 with the pilot lumen 158 . Along these lines, the full advancement of the first tube portion 124 and locking tabs 142 into the passage 146 results in the concurrent advancement of the first pressure sensing port 130 into the pressure sensing lumen 156 , and the first pilot port 134 into the pilot lumen 158 . As is best seen in FIG. 21 , those end portions of the pressure sensing and pilot lumens 156 , 158 extending to the side or face of the body portion 144 having the open end of the passage 146 extending thereto are each slightly enlarged relative to the remainder thereof. These enlarged end portions of the pressure sensing and pilot lumens 156 , 158 are adapted to accommodate respective ones of the first pressure sensing and pilot ports 130 , 134 which, as indicated above, are slightly larger than corresponding ones of the second pressure sensing and pilot ports 132 , 136 .
[0103] As will be recognized, the full advancement of the first tube portion 124 and locking tabs 142 into the passage 146 , and advancement of the first pressure sensing and pilot ports 130 , 134 into respective ones of the pressure sensing and pilot lumens 156 , 158 is limited by the abutment of that side or face of the body portion 144 of the female member 120 opposite that having the first and second gas delivery ports 148 , 150 protruding therefrom against that side or face of the base portion 120 of the male member 118 having the first tube portion 124 protruding therefrom. At the point of such abutment, the locking tabs 142 will releasably engage respective ones of the retention tabs 160 in a manner maintaining the male and female members 118 , 120 in releasable engagement to each other.
[0104] Each of the retention tabs 160 is sized and configured to be resiliently flexible. Based on the complementary shapes of the locking tabs 142 and retention tabs 160 , the application of compressive pressure to each of the retention tabs 160 when the male and female members 118 , 120 are cooperatively engaged to each other facilitates the disengagement of the retention tabs 160 from respective ones of the locking tabs 142 as allows for the separation of the male and female members 118 , 120 from each other. In the ventilation system 88 , it is important that the male and female members 118 , 120 not be cross-connected as could result in the pressure sensing lumen 138 of the male member 118 being placed into fluid communication with the pilot lumen 150 of the female member 120 , and the pilot lumen 140 of the male member 118 being placed into fluid communication with the pressure sensing lumen 156 of the female member 120 . To prevent such occurrence, as indicated above, it is contemplated that the locking tabs 142 and/or the retention tabs 160 of each pair may be provided with dissimilar configurations as ensures that the male and female members 118 , 120 can only be releasably connected to each other in one prescribed orientation relative to each other. As will be recognized, such orientation ensures that the pressure sensing lumens 138 , 156 are properly placed into fluid communication with each other, as are the pilot lumens 140 , 158 .
[0105] As is best seen in FIG. 21 , the full receipt of the first tube portion 124 of the male member 118 into the passage 146 of the female member 120 facilitates the placement of the gas delivery lumen 128 into fluid communication with a segment of the passage 146 , as well as each of the first and second gas delivery lumens 148 , 150 which each fluidly communicate with the passage 146 . Similarly, the complete advancement of the first pressure sensing and pilot ports 130 , 134 of the male member 118 into respective ones of the pressure sensing and pilot lumens 156 , 158 of the female member 120 effectively places the pressure sensing and pilot lumens 138 , 140 of the male member 118 into fluid communication with respective ones of the pressure sensing and pilot lumens 156 , 158 of the female member 120 . Thus, when the male and female members 118 , 120 of the Y-connector 94 are releasably connected to each other in the aforementioned manner, the gas delivery lumen 104 of the tri-lumen tube 90 is effectively bifurcated or divided, and thus placed into fluid communication with the gas delivery lumens 110 , 114 of the first and second bi-lumen tubes 96 , 98 via the gas delivery lumen 128 of the male member 118 , a segment of the passage 146 of the female member 120 , and each of the first and second gas delivery ports 148 , 150 of the female member 120 . In addition, the pressure sensing lumen 106 of the tri-lumen tube 90 is placed into fluid communication with the pressure sensing lumen 112 of the first bi-lumen tube 96 by the pressure sensing lumen 138 of the male member 118 and the pressure sensing lumen 156 of the female member 120 . Similarly, the pilot lumen 108 of the tri-lumen tube 90 is placed into fluid communication with the pilot lumen 116 of the second bi-lumen tube 98 via the pilot lumen 140 of the male member 118 and the pilot lumen 158 of the female member 120 . Though not shown with particularity in FIGS. 16-18 and 21 , it is contemplated that the Y-connector 94 , and in particular the male and female members 118 , 120 thereof, may be outfitted with sealing members such as O-rings as needed to facilitate the formation of fluid-tight seals between the same when releasably connected to each other.
[0106] Referring now to FIGS. 24 and 25 , there is depicted a portion of a quad-lumen tube 190 which may be integrated into the ventilation system 88 as an alternative to the above-described tri-lumen tube 90 . The quad-lumen tube 190 has a generally circular, cross-sectional configuration, and defines four (4) lumens. More particularly, the quad-lumen tube 190 includes a gas delivery lumen 194 , a pressure sensing lumen 196 , a pilot lumen 198 , and an auxiliary lumen 200 . The pressure sensing, pilot and auxiliary lumens 196 , 198 , 200 are preferably disposed about the gas delivery lumen 194 in equidistantly spaced intervals of approximately 120°, and have identically dimensioned, generally circular cross-sectional configurations.
[0107] As is apparent from FIGS. 24 and 25 , the cross-sectional configuration of the quad-lumen tube 190 is not uniform along the entire length thereof. Rather, each of the opposed end portions of the quad-lumen tube 190 (one of which is shown in FIG. 24 ) have cross-sectional configurations differing from that the central section or portion of the quad-lumen tube 190 extending between such end portions. More particularly, as seen in FIG. 25 , the gas delivery lumen 194 defined by the central portion of the quad-lumen tube 190 extending between the end portions thereof does not have a generally circular cross-sectional configuration. Rather, portions of the quad-lumen tube 90 which accommodate respective ones of the pressure sensing, pilot and auxiliary lumens 196 , 198 , 200 protrude into the gas delivery lumen 194 , thus imparting a generally cloverleaf cross-sectional configuration thereto. In contrast, at each of the opposed end portions of the quad-lumen tube 190 , those portions of the quad-lumen tube 190 accommodating respective ones of the pressure sensing, pilot and auxiliary lumens 196 , 198 , 200 transition to the exterior of the gas delivery lumen 194 , thus resulting in such gas delivery lumen 194 assuming a generally circular cross-sectional configuration. Those of ordinary skill in the art will recognize that the quad-lumen tube 190 may be formed so as not to include the aforementioned alternatively configured end portions, the non-circular cross-sectional configuration of the central portion of the gas delivery lumen 194 thus being consistent throughout the entire length of the quad-lumen tube 190 . However, if the alternatively configured end portions are provided, it is contemplated that they may be formed through the implementation of a specialized extrusion process, or as separate parts which are glued or molded onto the aforementioned central portion of the quad-lumen tube 190 . In the quad-lumen tube 190 , it is also contemplated that the inner diameters of each of the pressure sensing, pilot and auxiliary lumens 196 , 198 , 200 will be similar to those of the pressure sensing and pilot lumens 106 , 108 of the tri-lumen tube 90 as described above, with the cross-sectional area of the gas delivery lumen 194 being similar to that of the gas delivery lumen 104 of the tri-lumen tube 90 as also described above.
[0108] As will be recognized by those of ordinary skill in the art, providing the gas delivery lumen 194 with a generally circular cross-sectional configuration or profile at each of the opposed end portions of the quad-lumen tube 190 makes it easier to couple or operatively interface the quad-lumen tube 190 to a Y-connector at one end thereof, and to a flow generator at the opposite end thereof. Along these lines, the circularly configured end portions of the gas delivery lumen 194 are more easily advanced over and frictionally retained upon a cylindrically configured port, as opposed to a port that would otherwise need to be provided in a non-standard configuration so as to be capable of advancement into the gas delivery lumen 194 having the shape shown in FIG. 25 . In the quad-lumen tube 190 , the auxiliary lumen 200 may be used, for example, to route optical fibers or wires as could potentially be used to illuminate the Y-connector. Assuming such Y-connector has a two-piece, detachable construction as described above in relation to the Y-connector 94 , the illumination thereof would provide greater ease to a patient to effectuate the disconnection of the male and female members from each other at night, in darkness.
[0109] The quad-lumen tube 190 is preferably fabricated from a silicone, TPE or PVC material which has a Shore Hardness in the range of from about 50 A to about 80 A, and thus possesses a prescribed level of resilience and flexibility. Further, as seen in FIG. 24 , it is contemplated that the wall of the quad-lumen tube 190 defining or partially defining the gas delivery lumen 194 will have a spiral-shaped reinforcement ribbon 202 embedded therein. It is contemplated that such ribbon 202 will extend along the central portion of the quad-lumen tube 190 , but not into either of the alternatively configured end portions thereof. The ribbon 202 enhances the structural integrity of the quad-lumen tube 190 , thus making the gas delivery, pressure sensing and pilot lumens 194 , 196 , 198 less susceptible to collapse upon any excessive bending or compression of the quad-lumen tube 190 . It is also contemplated that the ribbon 202 could be substituted with a reinforcement braiding which is adapted to enhance the structural integrity of the quad-lumen tube 190 in the aforementioned manner. However, those or ordinary skill in the art will recognize that the quad-lumen tube 190 need necessarily have the ribbon 202 or other type of reinforcement braiding integrated therein. Along these lines, it is also contemplated that the quad-lumen tube 190 could further be alternatively configured such that the pressure sensing, pilot and auxiliary lumens 196 , 198 , 200 assume a generally helical profile along the length thereof, thus mimicking the effect of the effect of the ribbon 202 , and assisting in the prevention of the kinking or collapse of the quad-lumen tube 190 . Also, though not shown, it is contemplated that a reinforcement ribbon similar to the ribbon 202 or reinforcement braiding may be integrated into the above-described tri-lumen tube 90 .
[0110] This disclosure provides exemplary embodiments of the present invention. The scope of the present invention is not limited by these exemplary embodiments. Numerous variations, whether explicitly provided for by the specification or implied by the specification, such as variations in structure, dimension, type of material and manufacturing process may be implemented by one of skill in the art in view of this disclosure. | In accordance with the present invention, there is provided a mask for achieving positive pressure mechanical ventilation (inclusive of CPAP, ventilator support, critical care ventilation, emergency applications), and a method for a operating a ventilation system including such mask. The mask of the present invention includes a piloted exhalation valve that is used to achieve the target pressures/flows to the patient. The pilot for the valve may be pneumatic and driven from the gas supply tubing from the ventilator. The pilot may also be a preset pressure derived in the mask, a separate pneumatic line from the ventilator, or an electro-mechanical control. The mask of the present invention may further include a heat and moisture exchanger (HME) which is integrated therein. | 0 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a solar cover of an openable motor vehicle roof with a transparent cover panel which is at least partially surrounded in the edge area by a plastic frame, and which is provided with a solar cell network on the inside of the cover panel which extends into the vicinity of the cover panel edge area, and with an inner cover sheet which is located in the cover panel edge area and which overlaps the solar cell network with its inside edge. The invention also relates to a process for producing such a solar cover.
2. Description of Related Art
A solar cover of the above-mentioned type is known, for example, from German Patent No. DE 40 20 655 C1. In this known solar cover, the outside edge of the inner cover sheet is integrated into the plastic frame; this requires that the inner cover sheet is already attached to the inside of the cover panel when the plastic frame is connected thereto, for example, by foaming on. This is relatively complex. The problem in this known solar cover is, moreover, that the solar cell network extends into the area of the inside of the cover panel that is surrounded by the inner cover sheet which, in this area, is in contact with the solar cell network. This loads the network in a manner detrimental to the endurance strength of the solar cover, since application of a load to the solar cell network over the long run leads to delamination of this network.
Another laminate composite glass pane with embedded solar cells is known from DE-U1 85 35 648.
SUMMARY OF THE INVENTION
In view of this prior art, a primary object of the present invention is to devise a solar cover of the initially mentioned type which can be easily produced and which ensures a long service life without adversely affecting the solar cell network.
In addition, it is a further object to provide a process for easily producing the inventive cover.
These objects are achieved with respect to the solar cover by a gap being left between the inside edge of the inner cover sheet and the solar cell network so that the inside edge of the inner cover sheet remains disengaged from the solar cell network. Furthermore, optionally, the inner cover sheet is securely connected by means of adhesive to the combination of the cover panel and the plastic frame.
These objects are achieved with respect to the process for production of the solar cover by, first of all, the plastic frame being molded to the edge area of the cover before the solar cell network is applied to the inside of the cover, and then the inner cover sheet being cemented to the combination of cover and plastic frame, optionally with contact-free overlapping of the solar cell network.
The core of the invention is accordingly formed by contact-free overlapping of the solar cell network by the inner cover sheet. This contact-free overlapping ensures the endurance strength of the solar cover since, in contrast to the prior art, no forces which lead to delamination of the solar cell network over the long term are applied to the solar cells by the inner cover sheet. On the other hand, the overlapping ensures a sufficiently large useful surface for the solar cell network so that the attainable solar power measured on the surface of the cover is optimum.
According to one advantageous development of the invention, the inside edge of the inner cover sheet, in the solar cell network overlapping area, follows the contour of the overlapped area of the solar cell network in order to ensure as small as possible a structural height of the solar cover in the edge area.
Another key aspect of the invention involves the provision of an adhesive connection of the inner cover sheet to the combination of the cover panel and the plastic frame such that contact between the inner cover sheet and the solar cell network is prevented. The adhesive connection of the inner cover sheet to the combination of the cover panel and the plastic frame, at the same time, enables simplified manufacture of the solar cover because, after completion of the combination of the cover panel and plastic frame, the solar cell network can be laminated onto the inside of the cover panel before attachment of the inner cover sheet without adversely affecting the rubber mat which is necessary for this lamination process, because the plastic frame in the area of its bottom can be made almost as flat as desired. Only after laminating the solar cell network onto the inside of the cover is the inner cover sheet adhesively connected.
The plastic frame can be made so thin that it provides tolerance equalization for the cover panel edge. One advantage of this thin design of the plastic frame is relatively low consumption of the corresponding plastic material, preferably foamable polyurethane. The plastic frame adheres to the cover panel only over the width necessary for the strength of the cover panel.
In the plastic frame, there is advantageously at least one recess that is open towards the adjoining inner cover sheet for holding the adhesive that joins it to the inner cover sheet. This is done by applying and holding the adhesive in the required thickness in a defined manner. Furthermore, it is advantageously provided that, inwardly from the plastic frame on the inside of the cover, an adhesive bead is applied for joining the inner cover sheet to the inside of the cover. This measure makes it possible to connect a wider inner cover sheet to the inside of the cover panel in a stable manner, while insuring that the inner cover sheet is spaced away from the inside of the cover panel far enough to prevent contact between the inner cover sheet and solar cell network.
Advantageously, in the plastic frame, in addition to the recesses for holding the adhesive there can be depressions or openings to border the channels or cavities which are used to hold electric lines or components.
The process for producing the above described solar cover in accordance with the invention is based on the above described adhesive connection between the inner cover sheet and the combination of the cover panel and plastic fame in which, after completion of the combination of the cover panel and plastic frame, the solar cell network can be laminated onto the inside of the cover panel before attachment of the inner cover sheet without adversely affecting the rubber mat which is necessary for this lamination process, because the plastic frame in the area of its bottom can be made almost as flat as desires. Only after laminating the solar cell network onto the inside of the cover is the inner cover sheet adhesively joined such that its inside edge overlaps the solar cell network without contact.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show several embodiments in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial cross section of a first embodiment of a solar cover in the edge area;
FIG. 2 is a view similar to FIG. 1 of a second embodiment of a solar cover;
FIG. 3 is a view similar to FIG. 1 of a third embodiment of a solar cover;
FIG. 4 shows a version of the FIG. 1 embodiment without a cover film;
FIG. 5 shows a version of the FIG. 2 embodiment without a cover film;
FIG. 6 is a sectional view of the combination of the cover panel and plastic frame of the solar cover in the receiving area for an electronic component assigned to the solar cover,
FIG. 7 shows a view of an embodiment of the solar cover in the edge area from underneath before cementing the inner cover sheet to the cover panel/plastic frame combination;
FIG. 8 is a view similar to FIG. 4 of another embodiment of the plastic frame configuration; and
FIGS. 9 through 11 each show a schematic section of a respective alternative embodiment plastic frame for the solar cover.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the solar cover of an openable motor vehicle roof made in accordance with the invention comprises a transparent cover panel 1 , for example, of single pane of safety glass, which is surrounded in the edge area by a plastic frame 2 . The material of the plastic frame is preferably polyurethane which is foamed onto the edge of the cover panel 1 during the production which is explained in detail below. In addition, the solar cover comprises an inner cover sheet 3 which is used to stiffen the solar cover and to attach it to the cover displacement mechanism (not shown) and which is securely joined to the combination of the cover panel 1 and plastic fame 2 .
In FIG. 1, the plastic frame 2 and cover sheet 3 are formed in their area outside the cover edge such that they define a groove 4 which is open to the outside and which is used to hold a cover sealing element which is not shown. The groove 4 is formed in the plastic frame 2 by an undercut 5 and opposite the undercut by the outside edge 6 of the inner cover sheet 3 . The inside edge 7 of the inner cover sheet 3 is bent to have a U-shaped cross section in FIG. 1 and a border 8 that are spaced away from the inside of the cover panel 1 such that the solar cell network 9 can extend into the area of the cover panel 1 covered by the U-shaped inside edge 7 without coming into contact with it. This means that a gap S exists between the inside edge 7 of the inner cover sheet 3 left which is at least so large that, with consideration of different coefficients of thermal expansion of the pertinent materials, under no circumstances does contact occur between the inner cover sheet 3 and the solar cell network 9 . The solar cell network 9 extends, otherwise, essentially over the entire inside of the cover panel 1 as far as its edge and ends in front of the inner edge of the plastic frame 2 without being in contact with it. The bottom of the solar cell network 9 is covered by a cover film 9 a.
The inner cover sheet 3 is cemented onto the bottom of the plastic frame 2 of the solar cover. This, cementing according to the embodiment of FIG. 1, calls for applying cement in the form of a cement bead 11 which is located in a recess of the plastic frame 2 which runs preferably parallel to the edge of the cover panel 1 .
FIG. 2 shows another embodiment of the solar cover in its edge area. The embodiment of FIG. 2 differs from that shown in FIG. 1 in that the inner edge 7 of the inner cover sheet 3 is not made U-shaped, but is double-stepped instead. In front of the first step or angle 19 , between the inside of the inner cover sheet 3 and the inside of the cover panel 1 , there is a preferably peripheral cement bead 11 by which in addition to cementing the plastic frame 2 to the cover panel 1 another attachment site for the inner cover sheet 3 is made available. Instead of the cement bead 11 , in this position of the inner cover sheet 3 , a seal track can also be formed from a sealing material which is designed to seal the inner cover sheet 3 relative to the cover panel 1 , and not to fix the inner cover sheet on the cover panel 1 . In this embodiment, between the inside edge 7 of the inner cover sheet and the solar cell network 9 , a gap S is also left.
FIG. 3 shows a third embodiment of the solar cover in its edge area. This embodiment largely corresponds to that shown in FIG. 2 with the differcences explained below, the elements which correspond to those of FIG. 2 being labelled with the same reference numbers.
In contrast to the embodiment shown in FIG. 2, the inner cover sheet 3 is not attached on the outside of the plastic frame 2 , but is integrated into it; i.e. the outer edge of the inner cover sheet 3 is embedded in the material of the plastic frame 2 ,and at that site, where the inner cover sheet 3 emerges from the plastic frame 2 , there is an adhesive bead 11 or sealing cord which connects the inner cover sheet 3 to the cover panel 1 or in the case of a sealing cord, which borders the material of the plastic frame 2 to the inside during injection molding or casting.
In this embodiment of the solar cover, a peripherally externally open groove 4 is provided on the cover edge which, however, is formed exclusively in the plastic frame 2 in is case.
The embodiment of FIG. 4 differs from that of FIG. 1 only in the absence of cover film 9 a, and the same is true for the embodiment of FIG. 5 relative to that of FIG. 2 . Furthermore, the peripheral recess of the plastic frame 2 in which adhesive 11 is located, can be either a continuous recess in plastic frame 2 or can be a series of recesses that are interrupted by crosspieces, for example, as shown in FIG. 7, where three recesses 12 , 13 , and 14 are separated from one another by transverse crosspieces 15 , 16 , and 17 . In this way, in the area of the inner edge 10 of the plastic frame 2 receiving spaces for adhesive are formed which ensure that the adhesive for attaching the inner cover sheet 3 to the plastic frame 2 has an optimum adhesive gap thickness in each case. On the other hand, this means that only as much area of the inside of the cover panel 1 need be covered with polyurethane as is necessary for secure joining of the plastic frame of a cover panel and for delineation of the adhesive islands in the recesses 12 , 13 , and 14 of the plastic frame 2 .
As shown in FIG. 8, in the area of the inner edge 10 of plastic frame 2 , cable channels 18 can also be formed for routing the lines for electrical connections, for example, to the solar cell network 9 . FIG. 8 shows a single channel of this type which runs in an S shape via the transverse crosspiece 16 and thus comes to lie on the outside of the recess 13 or the inside of the recess 14 . In the area of the recess 14 , the channel 18 opens onto the inner side of the cover panel 1 which is occupied with the solar cell network 9 in order to establish contact with the network by means of a line which is not shown and which is laid in the channel 18 .
FIG. 6 shows a version of the embodiments of the solar cover as shown in FIGS. 2 or 5 at a special site which is preferably locally delimited and which is intended to hold, for example, an electronic component, for example, a DC/DC converter. For this purpose, there is a receiving space 21 for this component which is formed laterally by crosspieces 22 and 23 that are one piece with the plastic frame 2 . Otherwise, the receiving space 21 is bordered by the inside of the cover panel 1 and opposite the latter by a section 24 of the inner cover sheet 3 which runs over the crosspieces 22 and 23 .
FIGS. 9 to 11 show different embodiments of the plastic frame 2 after a production step of the solar cover before the inner cover sheet 3 is cemented to it. As FIG. 9 shows, and otherwise also FIGS. 1 to 6 , the plastic frame 2 can be molded flush with the top of cover panel 1 and surrounding the bottom edge area of the cover panel 1 . However, alternatively, as shown in FIG. 10, the plastic frame 2 can be offset from the top of the cover panel 1 , surrounding the bottom edge area of the cover panel 1 . In such a case, an upwardly facing, open groove 25 is provided for holding a sealing element instead of the downwardly facing groove 5 .
As FIG. 11 shows, another alternative is to have a plastic frame 2 which flushly borders the top of the cover panel 1 and has an outside screen 26 which projects below the bottom of the of the cover panel 1 and plastic frame 2 , so that a groove 27 is formed between the main body of the plastic frame 2 and the screen 26 .
The above described solar covers are produced such that, first of all, the plastic (polyurethane) for forming the frame 2 is molded or cast onto the edge of the cover panel 1 . In the next step of the process, the solar network is laminated onto the inside of the cover panel 1 . Only after this combination of the cover panel 1 and the plastic frame 2 is produced is the inner cover sheet 3 cemented to this combination, either exclusively to the plastic frame 2 , preferably using the above explained adhesive islands, or alternatively, additionally by means of an additional adhesive bead 20 (FIG. 6) also to the inside of the cover panel 1 .
While various embodiments in accordance with the present invention have been shown and described, it is understood that the invention is not limited thereto, and is susceptible to numerous changes and modifications as known to those skilled in the art. Therefore, this invention is not limited to the details shown and described herein, and includes all such changes and modifications as are encompassed by the scope of the appended claims. | A solar cover of an openable motor vehicle roof with a transparent cover panel ( 1 ) which is surrounded in the edge area at least in part by a plastic frame ( 2 ), with a solar cell network ( 9 ) which is provided on the inside of the cover panel ( 1 ) and which extends into the vicinity of the cover panel edge area, and with an inside cover sheet ( 3 ) which is located in the cover panel edge area and which overlaps the solar cell network ( 9 ) with its inside edge. To prevent load application by the inner cover sheet ( 3 ) to the solar cell network ( 9 ) which leads to delamination the inside edge ( 7 ) of the inner cover sheet ( 3 ) is located in a noncontacting, overly relationship with respect to the solar cell network ( 9 ). Furthermore, the cover sheet ( 3 ) is connected by means of adhesive securely to the combination of the cover panel ( 1 ) and the plastic frame ( 2 ). | 7 |
BACKGROUND OF THE INVENTION
1. State of Art
In dry cleaning processes it is very important to separate solvents which are retained after the cleaning and centrifuging within the textiles in order to avoid pollution of the air when taking out the clothing from the machine and in order to recover the solvents. For this purpose it is known to add a drying process by drying the circulating air and following drying by fresh air. For drying the circulating air the air in the machine is circulated by a blower drawing the air from the textiles via a lint trap and pressing the air through a condenser and heating device back to the drum or basket of the machine. After a drying interval of about 10 to 20 minutes the drying process of the circulating air is followed by a drying process by fresh air which is drawn via the cleaning chamber and condenser towards a discharge or exhaust duct including an adsorber for separation of remaining solvents. Hitherto such drying process has been performed with full blower power. This is disadvantageous on account of the fact that for a time unnecessary much air is driven through the textiles, the condenser and heater and that the cooperation between recovery by condensation and adsorption is unsatisfactory. The problem is to transport during drying the circulating air by heating as much solvents as possible in a period as small as possible from the textiles towards the condenser for separating by condensation and to deodorize during drying by fresh air said textiles so that it is possible to take out the textiles essentially inodorous. The maximum output of the blower, however, is necessary only at the beginning and at the end of the drying process. Therefore, if the output of the blower is not diminished during the drying process unnecessary high energy is consumed for heating of the circulating air before its entrance into the textiles and much cooling water is consumed unecessarily for cooling the air leaving the textiles.
It has already been proposed to improve the recovery of solvents by the insertion of a water chamber within the air duct to the adsorber. However, such a water chamber generally represents a constant flow resistance and therefore is not suitable to adapt the volume of air flow to the rapidly changing concentration of solvent vapours. Furthermore, such water chamber has the disadvantage that little drops of water are drawn by the stream of air towards the adsorber and thus will diminish the effectiveness of the adsorbent material. Besides this, the separation of residuals of solvents by fresh air during the fresh air drying period is handicaped and the expenditure of time is highly increased without any benefit.
2. Problem
The main problem of the present invention is to provide a method and apparatus as outlined above which may guarantee an optimal drying and recovery process with low expenditure of energy and time.
SOLUTION OF THE PROBLEM
In achieving this aim, the invention starts from the principle that the drying and recovery process is running under rapidly changing conditions and that it therefore is necessary for optimal performance to adapt said factors very sensitively during the drying process. This can be reached according to the present invention in a very simple manner by that the volume of air stream per unit time interval (hereafter "air volume") is changed dependent on the condition values determining the effect of recovery by condensation and adsorption. Thereby it is possible to control the dwell periods of the mixture of air and solvent vapours within the textiles as well as within the condenser and adsorber and heater in such a manner that optimal proportions of influences are obtained for the recovery process.
In order to ensure a rapid and satisfying separation of solvents during circulating drying with low expenditure of energy it is advantageous to have a decreasing air volume during this drying process, for instance, by diminishing the air volume after heating to 1/10 of the initial air volume which then will be active at the beginning of the exhaust period through the adsorber. During the second drying period, the exhaust air drying period, the air volume preferably is increased beginning with a low value.
When heating the circulating air before entrance into the cleaning chamber with the textiles in it it is possible to reduce the heating energy so that a constant temperature of the circulating air is reached in spite of decreasing air volume. Also the volume of cooling water for the condenser may be controlled in such a manner that a given output temperature of the condenser is maintained.
After the beginning of the exhaust period the air volume is preferably controlled in such a manner that the fresh air will be heated up to approximately 60° C. within the yet warm textiles. The air volume may be controlled dependent on measured values of physical conditions influencing the separation of solvents, as for instance, concentration and/or temperature. Preferably the air volume is controlled automatically. Furthermore it is possible mostly to control the change of air volume by a timer which in some cases may be adjustable subject to changing conditions like room temperature and character as well as volume of the textiles. Known means may be used for change of air volume. Preferably such means consists of means for choking or throttling the stream of air within the circulating way or exhaust way.
Also without any change of the chemical dry cleaning apparatus itself it may be possible to obtain an essential improvement of the efficiency of separation of solvents by condensation in the condenser of the dry cleaning apparatus and following adsorption within the adsorber, merely by changing the air volume during the exhaust period of the drying and separation process. In such a case means for controlling the air volume are necessary only in the exhaust pipe, for instance, by providing the air inlet of the adsorber with means for throttling the air stream. In such a case it is advantageous to provide the adsorber with two separate air inlets, namely a first inlet which is provided with means for throttling the air stream and a second inlet for fresh air which is used for regeneration of the adsorbent. By a good dosage of air volume during the exhaust period it is possible to reach optimal conditions during the separation by condensation within the condenser of the cleaning machine as well as during adsorption in the connected adsorber and that in connection with small expenditure of energy and simple and compact technical means.
DESCRIPTION OF EMBODIMENTS
In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate diagrammatically and by way of example a preferred embodiment thereof, and in which:
FIG. 1 is a diagrammatic view of a dry cleaning machine with connected adsorber and regulation of air volume by a throttle means within the common part of circulation-and fresh air way,
FIG. 2 is an apparatus like that of FIG. 1, however, including separate means for throttling of the circulating air and the exhaust air,
FIG. 3 is an apparatus like that of FIG. 1, however, with regulation of air volume by a timer and
FIG. 4 is a diagram for illustration of the operation of the apparatus of FIGS. 1 to 3.
During the cleaning process which takes place in advance to the process for drying and separation of the solvents the textiles to be cleaned are subjected within a rotating drum or basket 1 of the cleaning chamber 2 to the influence of a cleaning substance including a chemical means like, for instance, Perchlorethylene, named solvent in the following description. At the end of the cleaning period the textiles are separated by a centrifugal power and then are dried for separation of most of solvents. This drying process is performed in two succeeding processes, namely a circulating interval and an exhaust interval.
During the circulating interval drying air is driven within a cycle by a blower 3 from the cleaning chamber 2 via a lint trap or fibre catching device 4 and then pressed through a condenser 5 and a heater 6 back to the cleaning chamber 2. The circulating air which is heated up to, for instance, 60° within the heater 6 will heat the textiles within the drum 1 and will take away solvents form the textiles. The air with increased concentration of solvents then will be cooled within condenser 5 by cooling water down to an outlet temperature of preferably smaller then 30° C. Almost all solvents at the entrance of condenser 5 exceeding the volume corresponding to the saturation temperature at the outlet of the condenser will be condensed and be separated as a liquid over a water separator to a tank of the cleaning machine.
After a certain interval the length of which is dependent on the character of the textiles the outer parts of the textiles will be dried. In the following interval the drying process will run more slowly because the solvent molecules have to travel a longer way of diffusion in order to be taken by the circulating air. Therefore, the concentration of the circulating air will diminish and also the volume of condensed solvents within the cooler. In other words, only immediately at the beginning of the drying process when the textiles or other goods to be cleaned have reached the desired high temperature the circulating air may reach for a short period the preferred saturation concentration corresponding to the temperature of the air when leaving the textiles. Only during this very short period a high quantity of solvents is separated within the condenser which portion will rapidly diminish. This may be observed within the show window between condenser and water separator or within the duct from the condenser to the water separator. At the end of the drying process there are only few drops which may be separated from the circulating air. Therefore, it is in such case not advisable to continue the drying process because the expenditure of energy does not justify a continuation of the drying process under these circumstances. At this time the concentration at the inlet and outlet of the condenser will approximate one another, if for instance the condenser will give a cooling of the circulating air from 60° C. to 35° C. the circulating air at the outlet of the condenser will leave the condenser with a saturation concentration of about 300 g Perchlorethylen and it will take over solvents from the surface of the textiles in spite of heating up to 60° C. only in such a small degree that the concentration at the inlet of the condenser will increase only very little above 300 g/m 3 . Therefore, the drying process during the circulating period must be interrupted or finished as soon as the condensation within the condenser 5 practically has seized.
The solvents which remain after interruption of the circulating drying process must be removed or separated by fresh air. This is performed by changing over from circulating interval to fresh air interval.
By help of a switch for fresh air 7 valve for exhaust air 8 this change over to fresh air drying is operated. Doing this the heater 6 is switched out and fresh air is drawn through a duct 9 for fresh air by the blower 3 through the cleaning chamber 2 and lint trap 4 and is driven through condenser 5 and exhaust duct 10 to the adsorber 11, in which the remaining solvents are adsorbed so that highly cleaned air may leave the condenser through exhaust duct 12.
Within the common part of the circulating way and fresh air way there is provided a throttle device 13 between condenser 5 and exhaust valve 8. This throttle device may be adjusted by hand. In the embodiment of the drawing a regulating member 14 is provided which is operated via a control line 16 by an output signal of a calculator 15 inputs of which are connected to separate gauges for measuring of the condition values within the circulating air stream and fresh air stream. Such gauges 17 and 18 are shown for measurement of concentration at the inlet and outlet of condenser 5 and an additional guage 19 for the measurement of the output temperature at the cleaning chamber 2.
The calculator 15 may be programmed such that the operation is performed with maximum air volume without throttling the beginning and until the difference of the concentration between inlet and outlet of the condenser will decrease down to a given minimum. Subsequently the air volume will be diminished by adjustment of the throttling device 13 down to, for instance, 1/12 of the volume at the beginning. At a given low level of concentration difference at the gauges 17 and 18 change over from circulating interval to fresh air interval takes place. For this purpose the calculator 15 may be connected via a special control line 20 to regulating members 21 and 22 of change over switches 7 and 8. By this measurement an essential improvement of the drying process and a reduction of expenditure of energy is reached. Preferably the volume of circulating air and its temperatures may be adapted to the procedure of the drying process by corresponding adjustments. By reductions of the air volume circulation at the end of the circulation period the contact time between textiles and circulating air is increased. The degree of exchange increases in spite of diminished stream velocity on account of the constant contact surface between textiles and streaming air. Consequently, the concentration will increase compared with the concentration at the hitherto used constant velocity of air stream.
Within condenser 5 the circulating air will be cooled to a higher degree on account of the decreased velocity and solvents will be condensed according to this lower outlet temperature.
The decrease of air volume will be followed by a decrease of partial pressure of the solvents within the circulating air at the inlet of cleaning chamber 2 and with an increase of evaporation.
If beginning the fresh air drying process with an air volume lower than done hitherto, then a portion of the solvents taken over by the fresh air may be condensed within the machine. In order to obtain such a condensation the amount of air is throttled also at the beginning of the fresh air drying period so that a mixed temperature and a mixture condition is reached according to a higher temperature and a higher concentration than at the outlet of the condenser. Then, solvents surmounting the saturation concentration at outlet temperature will condense within the condenser. At the beginning of the fresh air drying period, therefore, one will continue with lower air volume. This lower air volume may be adjusted by the calculator at throttle 13 in such a manner that the fresh air will be subjected to an increase of temperature up to 60° C. within the textiles which temperature may be measured by gauge 19. The fresh air, which is primarily throttled, will cool the warm textiles continuously and will shift the mixture condition more and more into the area in which no solvent is separated within condenser 5.
In order to finish or interrupt the drying and separation procedure within a period as short as possible and in order to take out the textiles highly inodorous from the drum 1 it is preferred to increase the air volume V L approximately to the value of the usual value during the fresh air drying procedure. The difference of concentration between inlet and outlet of the condenser 5 is observed. At a given minimum, throttling of the air stream is interrupted so that fresh air will stream through the textile and the condenser 5 to adsorber 11 in an increasing amount.
The air leaving the machine at the beginning of the fresh air drying process will contain solvents to a degree which will make possible an additional separation. However, the entire amount of solvent coming into the adsorber 11 will be smaller than in the hitherto known apparatus using a constant air volume and consequently the connected adsorber will have a longer operation period because it can take over more charges. In the embodiment of FIG. 2 separate throttles 23 and 24 are provided for circulating air and fresh air. The throttle device for circulating air 23 is arranged within the duct between valve for air discharge 8 and valve for fresh air 7 in which duct is arranged also the heater 6. This portion of duct 25 is disconnected at change over from circulating period to fresh air period and the control of air volume will be taken over by throttle 24 which is controlled through control line 29. This throttle device 24 simultaneously represents the inlet for the exhaust air of adsorber 11. The adsorber thereby is provided with separated air inlets, namely the throttling exhaust air inlet 24 and a fresh air inlet 26 for regeneration of the active charcoal.
In the embodiment of FIG. 3 a timer 27 is provided for control of throttle 13 as well as valves 7 and 8. This timer is started by blower 3 via a starting line 30. This timer may be programmed in such a manner that it will control for the normal case the air volume in the desired optimal way in adaptation to the circumstances and especially to the dimension of the cleaning machine and adsorber.
The difference of concentration at the entrance and outlet of condenser 5 may be measured by a difference unit 31 and may be utilized for control of timer 27 in order to adapt the operation to unnormal conditions of solvent separation in the condenser 5.
If for instance this difference will decrease below a given minimum at a moment in advance of the normal time for change over from circulating interval, to fresh air interval then this change over should be take place earlier than programmed within timer 27.
As may be seen from FIG. 4 in the normal case the air volume will be increased during a first circulating interval U 1 up to a maximum in order to reach a desired heating of the circulating air up to an output temperature of heating device 6 of, for instance, 60° C. Consequently the air volume will be diminished during a following circulating interval U 2 of, for instance, 14 minutes gradually down to a minimum. After change over at the end of said circulating interval U the air volume will during unchanged adjustment of throttle 13 decrease on account of the additional flow resistance within the adsorber 11 as is illustrated in FIG. 4. The fresh air will then be heated up to approximately 60° C. within a first fresh air interval F 1 so that condenser 5 at the beginning of this interval F 1 will operate with essentially unchanged conditions or conditions like that at the end of cirulating interval U 2 . If the adsorber 11 is provided with a separate blower it is possible to avoid the sudden decrease of air volume at change over from circulating operation to fresh air operation and may even be changed to a little stepwise increase of the air volume. Very soon after the beginning of the fresh air interval F the entrance temperature of condenser 5 will decrease from the beginning temperature of 60° C. and will move against the outlet temperature of 25° to 30° C. As soon as this occurs change over to full fresh air volume is performed within the adjoining fresh air interval F 2 , so that adsorber 11 will perform the separation of the remaining sovlent. After a total drying time of approximately 18 minutes the separation of solvents from the whole system is finished. Even during the last portion of the fresh air drying process the cleaning machine is opened and the textiles may be taken out and new textiles to be cleaned may be brought in. The blower 3 then is switched out and the next cleaning process may follow.
By throttling the air stream at the beginning of the fresh air interval the separation process by condensation in condenser 5 is increased and adsorber 11 may be operated for a longer time in cleaning circuits.
The heating of the circulating air within heater 6 is controlled preferably in such a manner that in spite of change of air volume heating is performed up to a given temperature of, for instance, 60° C. Furthermore, the amount of cooling water within condenser 5 is controlled in such a manner that an essentially constant outlet temperature of, for instance, 30° C. is maintained.
It is evident that those skilled in the art may now make numerous uses and modifications of and departures from the specific embodiments described herein without departing from the inventive concepts. Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in or possessed by the apparatus and techniques herein disclosed and limited solely by the spirit and scope of the appended claims. | In a process for recovering solvents from the circulating air and exhaust air of a drycleaning machine by drying the circulating air and by fresh air drying with condensation and adsorption, the volume of air stream per unit volume is controlled in accordance with temperature and/or solvent concentration and heating and cooling energy reduced to achieve drying and recovery of the cleaning solvent with relatively low expenditure of energy and time. | 3 |
RELATED APPLICATIONS
This application is a continuation-in-part of the application of Adrian Ionescu entitled "Switchmode AC Power Controller", filed on Oct. 27, 1993, and having the Ser. No. 08/143,338, now U.S. Pat. No. 5,500,575.
FIELD OF THE INVENTION
This invention relates to alternating current power regulators, and more particularly to regulators used for varying and terminating the alternating electromotive force ("voltage") output applied to a variety of loads, including but not limited to lighting systems, power supplies, circuit breakers, appliances, and power distribution networks.
BACKGROUND OF THE INVENTION
Alternating Current ("AC") power regulation has been implemented in a variety of ways. Several of these implementations provide a variable sinusoidal output voltage to an intended load. Where the intended load is a light source, like incandescent, fluorescent, metal halide, or high pressure sodium lamps, the power regulator is also known as a "dimmer."
The advantage of providing a variable sinusoidal output voltage resides in the fact that a sinusoidal voltage produces a relatively low electrical and mechanical noise level during operation. The electrical noise in this sense refers mainly to signals back-propagated into the AC power supply, e.g., third, fifth, seventh, ninth, or other odd harmonics, which distort its almost pure sinusoidal wave-form.
One power control method that preserves the sinusoidal wave-form utilizes a high power variable resistor in series with an intended load. Since the resistor increases the overall load resistance seen by a voltage source (R seen =R load +R resistor ), and according to Ohm's law current is inversely proportional to resistance (I=V/R), the amount of current flowing through the intended load is reduced. Hence the voltage across the load is also reduced (V load =I load R load ) in the same proportion as the current. This method is also know as a voltage divider, and can be used in both direct current and alternating current electric networks. The series resistor, however, dissipates large amounts of power as heat (P=I 2 R resistor ), resulting in a low overall efficiency.
Another method of regulating the output voltage employs a manual or motor driven variable voltage transformer to deliver a controllable voltage to the load. Although the efficiency of this method is relatively high, the size, weight and cost of the equipment renders this method unsuitable for many applications that require compact design and quick response time. Additionally, the variable voltage transformer, like any other mechanical device, is subject to mechanical wear. Lastly, an additional cost is incurred for an external fuse or circuit breaker to protect the internal winding from self-destruction during an output overload or short-circuit.
In yet another method, a variation of the generic D class amplifier electronic power circuit has been used to synthesize a variable output sinusoidal voltage. U.S. Pat. No. 5,018,058 to Ionescu et al, describes a dual conversion high frequency switching AC controller. After the first conversion, two 60 Hz modulated unipolar variable voltage sources provide the voltages required by the output stage, designed along the class D amplifier guidelines. Pursuant to this patent, however, both unipolar voltage sources used by the output stage are not DC, but rather are two half cycle waveforms, of a higher magnitude than the input voltage. Although this method could in principle be used for providing power to numerous applications, it represents expensive overkill for those not requiring very precise waveform modulation. The accurate reconstruction of an ideal sinusoidal output waveform achieved by the amplifier, virtually independent of the input voltage waveform, will impose a relatively high manufacturing cost for most applications, especially for those not requiring perfect sinusoidal output. For the purposes of regulating power to a lighting system, power supply, and to most appliances, this particular method represents a cost which may not be justifiable to the consumer.
Aside from these sine wave maintaining systems, a relatively newer class of power regulators use triacs or silicon controlled rectifiers (SCR's) operating under what is generically called "variable phase angle modulation." In these methods, the triac is turned on at different phases of each half cycle of the sinusoidal waveform. The abrupt on/off switching action of the SCR creates discontinuity in the sinusoidal waveform, thereby introducing noise to the line. The sharp and prolonged discontinuity also results in a large current surge through the load each time the turn-on event occurs. This high turn-on surge current injects major mechanical and electric noise (odd harmonics) back into the electric network. Such noise is a serious problem at the high current levels that would be present in many applications, such as a lighting system for a theater or an outdoor lighting situation such as at a ball park.
To solve this problem, many systems have employed expensive equipment seeking to reduce or eliminate both mechanical and electrical noise. For example, in some cases a large output inductor has been connected in series with the load to limit the di/dt factor by distributing the surge current at the turn-on point over several hundred microseconds. There is a limit, however, to the period of time over which the surge may be smoothed without sacrificing the regulator's overall efficiency. A typical rule of thumb is that the time period cannot exceed one millisecond. A load requiring higher power levels will need a longer period of time for distributing the turn-on surge current than a load requiring lower power. The long time period associated with a system tuned for high power loads will still cause significant amounts of mechanical and electrical noise, especially when a mismatched lower power load is used.
U.S. Pat. No. 4,633,161 to Callahan et al., describes an inductorless phase control dimmer. This patent is directed to the elimination of the filter inductor from the output stage of a dimmer. A pair of MOSFETs are slowly turned on resulting in a low di/dt factor and practically very little mechanical and electric noise. The major disadvantage of this invention is the large amount of power dissipation which occurs while both MOSFET's are operating in linear mode, during their turn on process. Additionally, the R d 's of the MOSFET's increase with the temperature, thereby further increasing the amount of power dissipated. Often, a large heat sink is needed to properly dissipate the resulting heat. In the case of an output overload or short circuit, the absence of an inductor will cause a sharp output current increase, which may reach fatal levels before the internal current limiting system can react and turn off the MOSFET's.
Depending upon the particular application of the power regulator, various means are used to set the desired output power level. Many systems still employ a manual open loop means such as a dial or knob in conjunction with an output level meter, thus allowing an operator to set the desired output power level. Newer systems, however, use automated, closed loop means. For example, infrared and sonic motion detectors are sometimes used to trigger the turning on or off of a lighting system. Light meters are also used in order to turn on lighting in an area after the natural light level in the area falls below a certain minimum value. The disadvantage of many of the currently available automated control lighting systems, however, is that they are usually not integrated into a power regulator, and thus have to be interfaced with an existing power distribution system using expensive interface equipment.
Due to the potential for overloads and short-circuit conditions in lighting and power distribution networks, circuit breakers are often employed to safeguard against the consequences of such occurrences. A circuit breaker is placed in series with a load and when the current flowing through the circuit breaker exceeds some predefined level, the circuit breaker opens, or "trips", terminating all current flow to the load. There are two primary drawbacks to the standard circuit breaker, the first is a slow response time. The typical circuit breaker works on the principle of thermal expansion of a conducting element. When the current running through a circuit breaker exceeds a predefined limit, ohmic heating of a conducting element within the circuit breaker causes the element to expand to a point where the expansion triggers the release of a spring which in turn moves the conducting elements out of the conducting path and breaks the circuit. Since the circuit breaker is mechanical in nature, it is subject to the inherent limitations of all mechanical devices, one of which being a slow response time relative to that of an electrical system. It may take anywhere from several milliseconds to several seconds before a circuit breaker trips in response to a short circuit or overload condition. This period is much longer than it would take for serious damage to occur to sensitive electronic components.
A second drawback to the standard circuit breaker is that it must be physically reset each time it has been tripped. Even if the condition which originally caused the circuit breaker to trip no longer exists, the circuit breaker will not reset and close the power supply circuit. An individual will have to manually reset the circuit breaker.
SUMMARY OF THE INVENTION
The present invention provides a solid state, high frequency AC power regulator which avoids the difficulties and disadvantages of prior AC power regulators. The invention provides for an amplitude controlled output waveform almost identical with the waveform of the applied input AC line voltage. When used to control power delivery to a lighting system, the present invention is also known as a "dimmer." Additionally, the present invention may be used as a high speed circuit breaking system which avoids the difficulties and disadvantages of currently used circuit breakers.
The invention contains an RFI filter interface to the input AC line, which limits the magnitude of switching transients injected back into the AC line. As a solid state relay it acts as a high speed circuit breaker which automatically resets upon the termination of the condition which had caused the excessive current flow and had triggered the relay to open. Additionally, the output power level is capable of being set through a variety of input devices including but not limited to a timer, a light detector, a motion sensor, or the like. The regulator can be set to either increase, decrease or terminate power to the load in response to a signal from any of the aforementioned input devices.
The invention is suited to control power output to various lighting devices including but not limited to incandescent, fluorescent, metal halide, and high pressure sodium lamps. The present invention can also be used to regulate power to a variety of other loads such as appliances and entire power distribution networks.
Other objects and advantages of the invention will become apparent herein, and the scope of the invention will be articulated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described below with reference to the accompanying drawings, in which;
FIG. 1 is a block diagram of a preferred embodiment of the invention;
FIG. 2 is a block diagram of an alternate embodiment of the invention;
FIG. 3 shows a variety of signals, describing the switchmode operation of the preferred embodiment;
FIG. 4 shows a variety of signals, describing the operation of the output overload and short-circuit protection block, and the temporary current limiting process;
5 shows another circuit configuration of the AC solid state switch 20 and synchro-flywheel 30 used in the embodiment shown in FIGS. 1 and 2; FIG. 6 is a further circuit configuration of the AC solid state switch 20 and synchro-flywheel 30 used in the embodiment as shown in FIGS. 1 and 2;
FIG. 7 shows possible locations of the current sensor 60, either as in the preferred embodiment, or as a low value current sense resistor;
FIG. 8 shows the power regulation block 1000 regulating power to a load 70 and receiving input from input device 130, where the load 70 is an electronic ballast and a fluorescent tube, and the input device 130 maybe one or more of the following: an audio sensor, an ambient light meter, an infra-red occupancy detector;
FIG. 9 shows the power regulation block 1000 regulating power to a load 70 and receiving input from input device 130, where the load 70 is an electronic ballast and a metal halide or high pressure sodium light, and the input device 130 is one or more of the following: an audio sensor, an ambient light meter, an infra-red occupancy detector;
FIG. 10 shows the power regulation block 1000 regulating power to a load 70 and receiving input from input device 130, where a relay 140 is in series with the load 70, and the input device 130 is a remote reset.
DETAILED DESCRIPTION
A preferred embodiment of the present invention will now be described with reference to the attached FIGS. 1 through 10.
FIG. 1 depicts a basic simplified block diagram of the invention showing its principal elements. An AC solid state switch 20 supplies the load current, with its on/off ratio (duty cycle) set according to the desired output voltage on line 5 and load current requirements. An output filtering and wave-form re-shaping stage is provided having an inductor 40 and a filter capacitor 50. A synchro-flywheel 30 allows the discharge of the excessive energy stored in the output inductor 40. The synchro-flywheel 30 is reverse biased during the time the AC solid state switch is on and direct biased when the AC solid state switch 20 is off. The inductor 40 discharge current travels through a load 70, the synchro-flywheel 30 and the inductor 40. During the inductor 40 discharge portion of the cycle, current continues to flow in the same direction and the output voltage maintains the same polarity as the input voltage encountered during the time the AC solid state switch 20 was on, increasing the overall system efficiency and reducing the output voltage ripple. Thus it may be observed that the synchro-flywheel 30 discharges the inductor 40 during the time off cycle of the switch 20 to maintain the sine-wave form of the output voltage.
As best shown in FIG. 5, the synchro-flywheel 30 has two common source MOSFET switches. Depending upon the polarity of the AC signal, a conductive path is established either through the upper diode and lower MOSFET, or vice versa.
If an output current sensing device 60, perceives a current above some preset maximum, it controls the pulse width modulation pulses to reduce the output voltage such that the unit behaves as a constant current source at the preset maximum current level, providing a constant output current on line 5 capable of accommodating loads with large thermal lags. If overloading persists, then the current is shut off completely after a preset period of time has expired. If the output current sensing device 60 encounters a current sufficiently high to clearly indicate either a short circuit or overload condition, it shuts down the regulator immediately without the limited period intended to accommodate for thermal lag. In this case, the current sensor 60 not only turns off the AC solid state switch 20, but also sends a signal to relay 140 to open, thereby terminating all current flow to the load 70. The system intermittently resets by closing the relay 140 and turning on the AC solid state switch 20. If the short-circuit or overload condition persists, the current sensor 60 will cause the regulator to shutdown once again. The regulator will attempt to reset a predetermined number of times before shutdown is final. Once shutdown is final, the operator must manually reset the regulator before the regulator will operate. FIG. 10 shows the power regulator block 1000 connected to a load 70, with a relay 140 in series, and a remote reset 150 used to reset the regulator after the regulator has had a final shutdown. The series relay 140 is such as to open or close a contact responsive to a overload condition in conductor 5.
A more detailed depiction of a preferred embodiment is shown in FIG. 2, which has corresponding elements similarly numbered to those in FIG. 1.
FIG. 2 shows an AC power controller having an RFI filter 10 that reduces the magnitude of high frequency switching electric noise and transients injected by the system back into the AC line 1. A variable reference 90 receives the AC voltage from the AC line 1, and generates therefrom a low voltage reference signal on line 6. The reference signal on line 6 controls an output voltage amplitude anywhere from zero to a maximum value equaling that of the input line 1 amplitude less any voltage losses in the circuit. The variable reference 90 can be a simple potentiometer, a DC gain controlled operational amplifier, or an "n" bit digitally gain-controlled operational amplifier, where "n" is the number of bits which can be selected to provide for the desired number of power level increments.
It is desirable, to allow for various means by which to adjust the setting of the variable reference. Input device 130 represents any one of a number of possible devices which may be connected to the variable reference 90 and used to continually adjust the variable reference 90, effectively adjusting the regulator's voltage and power output, either manually or automatically in response to a stimulus. Additionally, a combination of input devices may be used in conjunction, in order to provide multiple input paths and allow the regulator to respond to a variety of stimuli such as light, sound, motion or elapsed time, as indicated by a timer. FIG. 8 and FIG. 9 show three possible input devices 130 which may be connected to the variable reference 90, allowing the power regulator 100 to respond to a real world stimulus. A number of applications exist for the use of input devices in conjunction with the regulator 1000, including but not limited to the turning on/off or adjustment of lighting luminosity in response to any real world event, such as the passing of time, the dimming of natural light, or any action of a person, where such action is detectable by said input devices (e.g. motion, sound, light intensity or manipulation of a manually operated control knob).
The synchronized modulator 120 compares the variable reference signal on line 6 and the output voltage signal or feedback signal on line 14, thus controlling proper operation in all quadrants of the applied AC line voltage in synchronized polarity. If both the reference signal 1 and output voltage on line 6 signal on line 14 are positive, both signals are compared by the synchronized modulator 120 with regard to their instantaneous values. As shown in FIG. 3, the duration of the control signal pulses on line 15, as depicted in the left section of the graph, is increased if the output (feedback) voltage signal 14 is lower than the reference signal 6, or decreased, as depicted in the right section of the graph, if the output voltage signal 14 is higher than the reference signal 6. The internal signal on line 15 which controls the on/off duration of the AC solid state switch 20 is a series of control pulses whose duration is proportional to the difference between the reference signal 6 and output voltage feedback signal 14. The control pulses from the synchronized modulator 120 along line 15 will increase in duration, thereby increasing the duration that the AC solid state switch 20 remains on, when the signals meet the following instantaneous values criteria: 0≦Vo <Vin and Vref>Vo≧0, where V in is the AC line voltage 1 , Vo is the output voltage 5 and Vref is the reference signal 6. The synchronized modulator 120 will reduce the duration of the control pulses on line 15, thereby reducing the duration which the AC solid state switch 20 remains on, when 0<Vo<Vin and Vref<Vo≦0.
Alternatively, the reference signal 6 and the feedback signal 14 may also be DC signals which are similarly compared.
For a low power load 70 having a relative high internal resistance, it may be necessary to force the discharge of the output filter capacitor 50 in order to maintain a sinusoidal output voltage waveform on line 5, especially in the second and fourth quadrants. The instantaneous polarity of the voltage across the charged capacitor 50 is the same as the instantaneous polarity of the input AC line voltage 1. Since the synchro-flywheel 30 is reversed biased much of the time, the synchronized modulator 120 produces another train of pulses on line 9 when the current sensor 60 connected to the synchronized modulator 120 via line 13 senses that the current flowing to the load 70 on line 5 is below some predetermined value, thus indicating a buildup of charge in the capacitor 50. Each pulse on line 9 occurs after a short time delay of several hundred nanoseconds and ends several hundred nanoseconds before a new pulse is produced on line 15. This prevents the synchro-flywheel 30 from being direct biased during the time the AC solid state switch 20 is on. This delay would be encountered in the preferred embodiments of the solid state switching circuits as shown in FIG. 5 and FIG. 6 by the delays introduced by the gate to source and gate to drain capacitance of any power MOSFETs.
Inductor 40 must be discharged during the time the AC solid state switch 20 is turned off. The synchro-flywheel 30 performs this function by being reversed biased during the time the AC solid state switch 20 is on, and becoming direct biased with regard to the sense of the inductor discharge current when the AC solid state switch 20 is off. A synchro-flywheel controller 80 produces pulses on lines 7 and 8 connected to the "OR" gates 100 and 110, as shown in FIG. 3. Both pulses on lines 7 and 8 are related to the polarity of the input AC line voltage 1, as illustrated in FIG. 3. To avoid any overlaps, each pulse starts a few microseconds after zero crossing of the AC line voltage 1, and ends a few microseconds before zero crossing of the AC line voltage 1. For a high internal resistance load 70, pulses generated on line 9 by the synchronized modulator 120 are summed with pulses generated by the synchro-flywheel controller 80 on lines 7 and 8 by the "OR" gates 100 and 110, resulting in signal pulses on lines 11 and 12. Assuming that the AC line voltage 1 is positive, a pulse on line 7 is generated by the synchro-flywheel controller 80, to turn on the lower MOSFET switch for one half cycle.
The synchro-flywheel 30 is reversed biased with respect to the instantaneous polarity of the AC line voltage 1 during the time the AC solid state switch 20 is on, and therefore no current will flow through it. When the AC solid state switch 20 is off, the collapse of the voltage on line 3 causes the inductor 40 to discharge by producing a reversed polarity voltage on line 3. The "OR" gated pulses from the synchronized modulator 120 on line 9 are then also applied to the synchro-flywheel 30 causing both the MOSFET's to come "ON" and conduct (only during the OFF period of the solid state switch 20). Hence both MOSFETs are "ON" during the OFF period of the solid state switch 20, closing a circuit formed by the inductor 40, the load 70, and the sychro-flywheel 30, allowing the charge/discharge current of the inductor 40 to flow in either direction. The current through the load 70 therefore maintains the same polarity as the current produced by turning on the AC solid state switch 20. The process is performed in reverse when the AC line voltage 1 has a negative instantaneous value, now a pulse is generated instead by the synchro-flywheel controller 80 on line 8.
The timing signals of the synchro-flywheel 30 for a high internal resistance load 70 are shown in FIG. 3. The synchro-flywheel 30 is direct biased with regard to the instantaneous polarity of the AC line voltage 1 when the AC solid state switch 20 is off, following the timing rule above described. When the load 70 internal resistance is low, the load current is relatively high, and the capacitor 50 may not need to discharge through the synchro-flywheel 30 during the time the AC solid state switch 20 is off, for proper maintenance of a sinusoidal waveform of the output voltage 5. This case is shown in FIG. 4 as an overload condition. No pulses are generated by the synchronized modulator 120 on line 9, therefore the synchro-flywheel 30 is always reversed biased with respect to the instantaneous polarity of the AC line voltage 1, whether the AC solid state switch 20 is on or off.
Referring again to FIG. 3, in which a number of pulses have been artificially removed from various graphs in order to provide a better understanding of the process, the inductor 40 charge and discharge current waveform is shown. The pulse width modulation switching frequency is set at a value higher than the resonance frequency of inductor 40 and capacitor 50. The output voltage feedback on line 14, and the current sensor 60 supply current information of the load 70 to the synchronized modulator 120, which controls the pulse width modulation at a fixed switching frequency on lines 9 and 15.
Both the AC solid state switch 20 and synchro-flywheel 30 must be protected against output overloads or short-circuits. The current sensor 60 sends its load 70 current signal to the synchronized modulator via line 13. A preset reference signal is compared with the signal on line 13. When an output overload or short-circuit is encountered, the amplitude of the output voltage signal 14 is no longer usable as feedback. As shown in FIG. 4, in the left section of the graph, after a short overshoot, the output current through either a short-circuit or overload is limited to a safe value by drastically reducing the duration of pulses on line 15. If the load current does not fall below its maximum admissible value after a period of time longer than the thermal lag of a typical high power load, a permanent output current shut-off will occur. A system troubleshooting and manual reset will then have to be performed in order to restore normal operation of the regulator. The right section of the graphs shown in FIG. 4 illustrates the normal output current limiting for compensating for the load's thermal lag. When the load reaches its nominal "hot resistance" value, the output current limiting process stops, as further shown by the right section of the graph shown in FIG. 4. All output overload and short-circuit protection and temporary current limiting functions are performed by the synchronized modulator 120. If the current sensor 60 sends a signal on line 13 sufficiently strong to indicate a serious overload or short-circuit, and not just a condition due to the thermal lag of the load, the synchronized modulator 120 will not only take the steps mentioned above, but it will also send a signal on line 16 to the relay 140, opening the relay 140 and terminating all current flow to the load 70. The synchronized modulator will attempt to restart power delivery to the load 70 a predetermined number of times. If the excessive current condition persists, however, the synchronized modulator 120 will cause a final shutdown, after which point the operator must manually reset the regulator before the regulator will operate again. As illustrated in FIG. 10, a remote reset 150 may be used to reset the system after final shutdown.
FIG. 5 and FIG. 6 show two circuits for implementing the AC solid state switch 20 and synchro-flywheel 30. Although power MOSFETS were used in the preferred embodiment, power bipolar transistors and parallel diodes can be also used to perform the same functions.
FIG. 7 shows two possible configurations and locations for a current sensor 60 or a current sensor 230. Current sensor 60 used in the preferred embodiment is a wide bandwidth current transformer. Alternatively, a sense resistor 230 in series with the load 70 having a low value in the range of under 100 milliohms coupled to an operational amplifier and to the synchronized modulator 120 may be used.
FIG. 8 show the present invention with a power regulator block 1000 powering a load 70, where the load 70 is a florescent light having a ballast and a bulb. The regulator block 1000 receives input from input devices 130, where the input devices 130 can be any combination of an audio, and ambient light, or an infra-red occupancy sensor.
FIG. 9 show the present invention with a power regulator block 1000 powering a load 70, where the load 70 is a light source having a ballast and either a metal halide or a high pressure sodium bulb. The regulator block 1000 receives input from input devices 130, where the input devices 130 can be any combination of an audio, and ambient light, or a infra-red occupancy sensor.
FIG. 10 show the power regulator block 1000 powering a load 70, with a relay 140 in series with the load 70, so as to allow the regulator block 1000 to terminate current flow to the load 70 in case of a short circuit or overload condition. A remote reset 150 allows the regulator block 1000 to be reset in the event that a short circuit of overload caused the regulator 1000 to experience a final shutdown.
It should be understood that this invention may be reduced to practice using a large variety of circuit configurations without departing from the spirit and purpose of this invention. | A power regulator system provides power to an electrical load. A power level selector generates a reference signal which indicates a desired power level for the electrical load, and a control circuit connected with a AC power source interrupts flow of the AC current for periods of time responsive to a reference system from the power selector. A filtering circuit filters the output of the control circuit and generates therefrom a second output AC circuit which is smooth relative to this interrupted AC circuit. This smooth AC output is applied to the load. A relay is provided to prevent overload conditions from forming adjacent the load in the circuit. Various types of sensors may be used as the power level indicator, such sensors including the light detector as movement detectors, and other electrical sensors. | 6 |
CROSS-REFERENCE TO RELATED PATENT APPLICATION(S)
This patent application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/657,322 filed on Jun. 8, 2012, and U.S. Provisional Patent Application No. 61/788,785, filed on Mar. 15, 2013, the contents of each of which are hereby incorporated by reference in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
The invention described herein was made in the performance of work under a NASA contract and by employees of the United States Government and is subject to the provisions of 51 U.S.C. §20135, and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefore.
BACKGROUND OF THE INVENTION
Laminar flow is the smooth, uninterrupted flow of air over a surface, such as the contour of wings, fuselage, or other parts of an aircraft in flight. Drag reduction through the maintenance of laminar flow over greater chord lengths during the cruise portion of an aircraft's flight can yield to improved fuel efficiency over long distances. However, surface imperfections, especially on the wing leading edge, can lead to transition from laminar to turbulent flow increasing drag and fuel burn.
Flight tests have shown that insect impacts on wing leading edge surfaces can leave residue with critical heights sufficient to disrupt laminar flow and decrease fuel efficiency. Since maintenance of laminar flow is most critical during cruise, insect residue adhesion mitigation is an operational necessity for fuel-efficient configurations.
Accordingly, there is a need to provide an improved method of mitigating insect residue adhesion to a surface that does not add significant weight to increase efficiency of the aircraft.
BRIEF SUMMARY OF THE INVENTION
The present invention includes a process to modify a surface to provide reduced adhesion surface properties to mitigate insect residue adhesion. The process includes providing at least one article having at least one surface, topographically modifying the surface, and chemically modifying the surface by coating said surface with a low surface energy coating. The low surface energy coating may include a polymer composition having a surface energy of less than about 50 mJ/m 2 , or alternatively less than about 40 mJ/m 2 . The surface may comprise a water contact angle of greater than about 80 degrees, or alternatively greater than about 110 degrees. The modified surface may also comprise a surface roughness of about 0.2 micron to about 50 microns after the surface is topographically and chemically modified. The surface may comprise a surface roughness of about 1 microns to about 10 microns. In one embodiment, the surface may be topographically modified by laser ablation with an ablation depth of about 0.5 μm to about 30 μm. The laser ablation depth may be about 1 μm to about 10 μm.
In another embodiment, the surface may be topographically and chemically modified by spray deposition of a polymer particulate composition comprising a nanocomposite material where the nanocomposite material comprises silica nanoparticles.
In yet another embodiment, the coating may include a copoly(imide fluorinated alkyl ether), fluorinated silanes, fluorinated aliphatic compounds, silicones, or fluorine-containing polymers. The coating may alternatively comprise a silane composition. The silane composition may be prepared by generating 1-2% weight aqueous ethanol solutions with glacial acetic acid to induce acid hydrolysis of the alkoxy functionality of said silane composition. Alternatively, the silane composition may comprise a mixture of Si—C 6 , Si—C 12 , and Si—C 18 ; or Si—F 17 .
In yet another embodiment, chemical modification of the surface may also include chemical or physical vapor phase deposition, plasma deposition, submersion, spray coating, or spin casting.
These and other features, advantages, and articles of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a side, cross-sectional view of a surface having a substantially smooth topography.
FIG. 2 is a side, cross-sectional view of a textured surface having an uneven topography.
FIG. 3 is a side, cross-sectional view of a textured surface having an uneven topography and a chemical coating thereon.
FIGS. 4A-4C are alternative cross-sectional drawings of the textured surface having a random uneven surface ( FIG. 4A ), a uniform symmetrically uneven surface ( FIG. 4B ), and a repeating uneven surface ( FIG. 4C ).
FIG. 5 is a side, cross-sectional view of a textured surface having an alternative rounded pattern of peaks and channels.
FIG. 6 is a side, cross-sectional view of a textured surface having the alternative pattern of peaks and channels as shown in FIG. 5 further modified with a chemical coating thereon.
FIG. 7 is a micrograph of a surface that has been modified to create uneveness.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1 , the present invention includes providing at least one article 10 having at least one surface 12 to be chemically and topographically modified to mitigate residue adhesion to the surface 12 . The present invention can be used to reduce the adhesion of insect residue on various surfaces, including but not limited to, airplane, helicopter, airborne vehicles, automobiles, marine vessels, motorcycles, helmets, wind turbines, all-terrain vehicles, floors, building, exterior walls or windows, etc. The surface may comprise any surface which will be exposed to particles or objects that may become adhered to that surface, and may comprise various types of materials including, but not limited to, metal, inorganic materials, polymeric materials, composites, textiles, and combinations of the foregoing. Examples of metallic surfaces include aluminum, titanium and related alloys thereof, and examples of inorganic surfaces include glass and ceramic articles.
As discussed herein, the surface is described as a wing surface of an aircraft, which is one embodiment of the present invention. In this embodiment, the surface is substantially smooth and the topography of this unmodified surface facilitates the laminar flow of air across and/or around it.
One aspect of the present invention is chemical modification of the surface of the article. The chemical modification can occur through application of a chemical coating to the surface of the article. The chemical coating may comprise a low surface energy coating due to their minimization of interfacial interactions. In one embodiment, the surface energy of the coating comprises less than about 50 mJ/m 2 , or less than about 40 mJ/m 2 . The coating can be applied by various methods including, but not limited to, spray application, dip-coating, spin-coating, film casting, physical vapor phase deposition, chemical vapor phase deposition, crystal growth, electrochemical reaction, etc. For vapor phase deposition, the procedure may involve placing the surface to be functionalized into a sealed container along with a small amount of the coating composition (e.g. silianating agent). Evaporation of the coating composition enables the functionalization of the surface.
The chemical coating can persist on the surface either due to physical adsorption or chemical reaction with the article. For physical adsorption, the coating persists on the surface due to Van der Waals forces, electrostatic and magnetic interactions, mechanical interlocking, or any combination thereof. The chemical coating may be a fluorinated silanol and a precursor thereof, an aliphatic material, fluorinated aliphatic material, silicone, fluorine-containing polymer and copolymer, an epoxy, a urethane, and mixtures of two or more of the foregoing. Alternative chemical coatings that may be effective are also disclosed in U.S. patent application Ser. No. 13/286,715, filed on Nov. 1, 2011, which is incorporated by reference herein in its entirety.
For chemical reaction with the article, the species would consist of two components, a chemical moiety that tethers the chemical to the article through chemical reaction with functionalities on the article and a chemical moiety that generates a low surface energy coating. Chemical functionalities that could be used to tether the chemical species to the article include, but are not limited to: silanes, chlorosilanes, alkoxysilanes, primary amines, secondary amines, epoxides, alcohols, carboxylic acids, esters, among others. The number of chemical reactions between the article and the surface coating chemical can be any number equal to or greater than one. Similarly, the chemical species used to modify the surface may react with itself resulting in a multilayered coating. The chemical functionalities that result in a low surface energy include, but are not limited to: aliphatic functional groups including CH 3 , C 2 H 5 , any CnH 2n+1 or any hydrocarbon chain with unsaturation arising from double or triple carbon-carbon bonds; fluorinated aliphatic groups consisting of any number of carbon atoms with hydrogen and fluorine bonds such as CH 2 F, CHF 2 , CF 3 , C 2 H 2 F 3 , C 2 F 5 , any CnF 2n+1 , or any combination of H and F such that the total number of H and F atoms is equal to 2n+1 with n equaling the number of carbon atoms, or any fluorinated hydrocarbon with unsaturation arising from double or triple carbon-carbon bonds.
The thickness of the chemical coating can vary from less than a molecular layer that is a surface coverage consisting of coated and uncoated regions with an average thickness of about 0.5 nm, to coatings that are about 80 microns thick. The preferential coating thickness for coatings that persist by physical adsorption would be from about 1 nm to about 80 microns, more preferential thicknesses would be from about 100 nm to about 50 microns. For chemical coatings that persist as a result of chemical reaction with the article, the preferential thickness would be from about 0.5 nm to about 1 micron with a more preferential thickness from about 0.5 nm to about 100 nm. Similarly, the coating thickness is preferred to be no greater than the separation distance between two topographical features representing the lowest frequency topographical pattern intentionally imparted on the surface. The chemical coating uniformity can be described as the continuity of the same surface chemical composition. The chemical coatings described herein can be either uniform or non-uniform. A uniform coating is described as a uniform chemical composition of a single or multiple species across the article. A non-uniform coating is described as a chemical coating of a single or multiple species that is not of uniform composition across the article. This could include regions with no coating at all with the uncoated regions ranging from about 0.01% to about 50% of the modified surface.
The present invention also includes topographical modification of the surface of the article. Chemical and topographical modification can alternatively occur in a single step or multiple steps.
For the chemical and topographical modification to occur in a single step, the coating may comprise particulate matter such that application of the coating would chemically and topographically modify the surface of the article. In one embodiment, the coating may comprise a polymer particulate composition having a nanocomposite material (e.g. silica particles).
The surface can also be topographically modified separately from the chemical modification. The topography can be modified to create unevenness by either additive or subtractive methods including, but not limited to: lithographic patterning, laser ablation and chemical etching, physical vapor deposition, chemical vapor deposition, vapor phase deposition, crystal growth, electrochemical deposition, spin casting, and film casting. The unevenness may be imparted and defined in terms of a defined or random pattern of unevenness on the surface. The topography may be uniformly symmetric or asymmetric across the surface of the article. FIGS. 4A-C demonstrate examples of uneven topographies (see surfaces 42 , 44 and 46 of article 40 ) having a random ( FIG. 4A ), uniform symmetric ( FIG. 4B ), or uniform asymmetric ( FIG. 4C ) types of unevenness. The topography may be described by any manner of shapes including but not limited to: spheres, triangles, any polygon, pillars, recessed cavities, overhanging structures, etc.
Referring to FIG. 2 , the pattern that is visible and that is created from the smooth surface defines peaks 22 and channels 24 in terms of the height 26 and width 28 respectively of the topographical variations. The channels are measured by width 28 as the distance between the tops of adjacent peaks 22 that are formed in the surface 20 . As demonstrated in the profile view of FIG. 2 , the peaks 22 and channels 24 may have the same or similar size relative to other peaks along the surface of the article. The peaks 22 may be different heights 26 (defined as the distance from the bottom of an adjacent channel to the top of a peak). The channels 24 between the peaks 22 may have the same or similar widths 28 , or they may vary along the length of the channels that are formed along the surface. The peaks 22 and channels 24 may be relatively sharp in their shape, including perpendicular angles of the sides of the peaks and the floor of the channels. The shapes may also be rounded or curved or otherwise formed in the surface. Additionally, the surface topography could be comprised of any combination of rounded and sharp features.
FIGS. 5 and 6 illustrate a surface 50 having rounded, symmetric peaks 52 that are, as shown in FIG. 6 , coated with a coating 64 . Also, FIG. 7 is a micrograph that shows a surface textured using laser ablation as described herein.
The size of the peaks and channels on the modified surface of the article cannot be so great as to create significant turbulence in air that moves along the surface. Accordingly, the topographical features on the surface should vary between about 10 nanometers and about 80 microns in height, alternatively between about 0.1 microns and about 20 microns in height, or still further alternatively, between about 0.5 microns and about 10 microns in height. Similarly, the size of the channels is preferably in the range of about 10 nanometers to about four millimeters or alternatively about 10 microns to about 40 microns.
Additional topographical features may be present on the surface that are an order of magnitude smaller than the features described above generating a hierarchical or fractal surface topography. For example, a surface may consist of rectangular pillars with length, width, and height dimensions of about 10 microns. These pillars could have further topographical features on them consisting of rectangular pillars that have length, width, and height dimensions of about 500 nanometers. This would be considered a hierarchical structure.
An additional parameter to describe the surface topographical modifications encompassed in this invention is the surface roughness of the material. Although there are many different ways to calculate surface roughness, for this example, the average areal surface roughness values are used. These values can be determined by any microscopy or imaging technique that provides information in three dimensions such that the average of the peaks and valleys can be determined along both length and width axes. Surface roughness is calculated as the arithmetic mean of the absolute values for the vertical deviation of surface topographical features from the mean line. For the topographies described here, the surface roughness values should vary between about 0.2 micron and about 50 microns, between about 0.5 micron and 8 microns, between about 1 micron and about 10 microns, or yet further alternatively between about 1 micron and about 6 microns.
EXAMPLE
An aluminum alloy is used and topographically modified. The topographical modification of the aluminum alloy samples was realized using two techniques: spray deposition and laser ablation patterning following by chemical modification. For the spray deposition example, a solution was generated by combining nanometer sized silica particles with a hydrophobic coating (heptadecafluoro-1,1,2,2-tetrahydrodecyltriethoxysilane) in aqueous ethanol solution. For comparison, a similar solution was made with the only variation being the use of a hydrophilic coating (methoxy(polyethyieneoxy) propyltrimethoxysilane) instead of the hydrophobic coating. For the laser ablation patterned surfaces, patterning was performed with a PhotoMachining, Inc. laser ablation system equipped with a Coherent Avia® frequency-tripled Nd:YAG laser (355 nm, average power: 7 W). The laser beam diameter and scan speed were kept constant at 25 micrometers and 25.4 cm/s. A series of different laser parameters were evaluated with pulse energies ranging from 40 to 99 microjoules per pulse. The line spacing was also varied from 12 to 102 micrometers. Other examples and teachings regarding topographical modification using a laser are disclosed in U.S. patent application Ser. No. 12/894,279, filed Sep. 30, 2010, which is incorporated by reference herein in its entirety.
In this example, a chemical modification and coating was also performed. These surfaces were then chemically modified by exposure to (heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane in a 19:1 ethanol:water solution with a minute amount of acetic acid. The solution pH was measured to be approximately five. A small volume of this solution was placed on the laser patterned surface and allowed to react for five minutes. The surface was then rinsed with copious amounts of ethanol.
The surface that is both topographically and chemically modified as described was measured and assessed by using water contact angle goniometry. The surfaces were characterized using water contact angle goniometry with a First Ten Angstroms FTA 1000B contact angle goniometer. Several of the modified surfaces exhibited water contact angles in excess of 170 degrees. These surfaces were tested for insect adhesion under dynamic conditions using a custom-built pneumatic insect delivery device that delivered fruit flies to the surface at an average speed of 138 mph with a standard deviation of 27 mph. High-speed photography was obtained during impact events using a Vision Research Phantom 12 camera at a speed of 50,000 frames per second. Digital images of the post-insect impacted samples were obtained using an Olympus C-740 UltraZoom Digital Camera.
TABLE 1
Surface characterization and fruit fly impact results of laser ablation
patterned Al alloy surfaces and coated surfaces.
Profilometry Results
Pulse
Line
Water Contact
Maximum
Areal
Energy,
Spacing,
Angle, °
Roughness,
Height,
Coverage,
Coating
μJ/pulse
μm
Ablated
Silanated
R a , μm
μm
mm 2
Control
—
—
84 a
—
0.31
69
1.27
Control
—
—
—
110
—
66
0.71
& F17
LA-1
40
50.8
26
170
1.854
60
0.26
LA-2
40
25.4
82
162
2.227
66.1
1.33
LA-3
40
12.7
5 b
165
0.595
62
0.45
LA-4
65
101.6
5
162
2.549
89.7
0.31
LA-5
65
50.8
5
166
3.402
97
1.43
LA-6
65
25.4
5
167
4.166
100.7
0.77
LA-7
65
12.7
5
165
1.197
71.5
0.45
LA-8
99
101.6
5
166
2.154
66.4
0.40
LA-9
99
50.8
5
167
5.328
63.9
0.50
LA-10
99
25.4
5
171
5.11
66.6
1.31
LA-11
99
12.7
5
164
3.459
66.9
0.28
a Control surfaces were not laser ablation patterned.
b Contact angles reported as 5° were not able to be accurately measured due to rapid wetting of the surface where contact angles on these surfaces approached 0°.
The “Areal Coverage” column in Table 1 was determined using the optical surface profilometer. The areal coverage represents the surface area that has insect residue remaining on it after the test described herein and the insect impact samples discussed. Both the area and the height of the insect residue may be relevant for the purpose of any subsequent aerodynamic testing.
The results above are for exemplary purposes only, and one of ordinary skill in the art would adjust the various parameters depending on the desired reduction in adhesion properties, which would vary depending on the type of surface, conditions under which adhesion should be mitigated, coating types and methods of topographical modification.
While some embodiments of the invention have been herein illustrated, shown and described, it is to be appreciated that various changes, rearrangements and modifications may be made therein, without departing from the scope of the invention as defined by the appended claims. It is intended that the specific embodiments and configurations are disclosed for practicing the invention, and should not be interpreted as limitations on the scope of the invention as defined by the appended claims and it is to be appreciated that various changes, rearrangements and modifications may be made therein, without departing from the scope of the invention as defined by the appended claims. | A process to modify a surface to provide reduced adhesion surface properties to mitigate insect residue adhesion. The surface may include the surface of an article including an aircraft, an automobile, a marine vessel, all-terrain vehicle, wind turbine, helmet, etc. The process includes topographically and chemically modifying the surface by applying a coating comprising a particulate matter, or by applying a coating and also topographically modifying the surface by various methods, including but not limited to, lithographic patterning, laser ablation and chemical etching, physical vapor phase deposition, chemical vapor phase deposition, crystal growth, electrochemical deposition, spin casting, and film casting. | 8 |
BACKGROUND OF THE INVENTION
Semiconductor integrated circuits are becoming higher in density, higher in speed, and lower in power consumption, and what matters particularly in these devices is parasitic capacitance. For example, in a bipolar device, it is parasitic capacitance that is generated between collector and substrate, or in a MOS device, it is parasitic capacitance that is generated between source, drain and substrate. When this parasitic capacitance can be reduced, it is possible to compose a semiconductor device of higher speed and lower power consumption. Accordingly, as method of reducing this capacitance, many attempts have been made so far. Among others, there is an attempt of perfect isolation to replace parts immediately beneath and at sides of semiconductor device by insulators, and several prior arts relating to this attempt are described below.
In the U.S. Pat. No. 4,104,090, an anodically processed porous silicon is used to form an insulator layer immediately beneath the semiconductor region. In the first place, as the substrate, a P type silicon wafer having P + -layer on the surface is used. Then P- or N-layer is formed on this P + -layer by epitaxial growth. The surface of the silicon wafer is oxidized, and a proper opening is formed by photolithography. This opening is etched by reactive ion etching or other process to form a groove to reach said P + -layer. To make this entire P + -layer porous, the P + -layer is selectively etched by the anodic process. The porous silicon is heated in oxygen and water ambient to become silicon dioxide completely. Finally the groove is filled with silicon dioxide or the like, and the P- or N-region separated by the insulator from the substrate and its surrounding is formed.
In the Japanese Laid-Open Patent No. 56-12749, a method of perfect insulation separation employing the conventional LOCOS technology is disclosed. First, a silicon nitride film is formed on a surface of silicon substrate, and a proper opening is formed by photolithography. In succession, using the patterned silicon nitride film as a mask, a sharp groove is formed in the silicon substrate. When the silicon nitride film is deposited on the silicon substrate surface and etched by sputtering, since the etching is excellent in linearity, only the silicon nitride film on the silicon substrate surface and groove bottom is etched, while the silicon nitride film is left on the side wall of the groove. Afterward, when thermally oxidizing for a proper time, the oxide film formed on the groove bottom reaches further to the lower part of the monocrystalline silicon region, and is finally joined with the oxide film propagating from the adjoining groove bottom. Thus, the monocrystalline silicon is completely isolated from the substrate.
The Japanese Laid-Open Patent No. 59-8346 refers to an improved version of perfect isolation technique of the preceding Japanese patent. More particularly, a band-like groove to reach the N + - region is formed in the silicon substrate possessing an N + buried region. Then, through this groove, the N + -region is selectively etched, and the distance between adjacent grooves is properly determined. The N + -region between the grooves is heated and oxidized until wholly turning into an oxide film, and it is completley isolated from the substrate.
As other method, for example, K. H. Nicholas et al. reported a process of using an orientation dependent etching in ELECTRONICS LETTER, Vol. 20, No. 24, 1985, pp. 1014-1015. In this method, first a silicon nitride film is deposited on a silicon (100) wafer, and a pattern is formed by photoetching. Next, using the nitride film as a mask, grooves are formed in the silicon substrate by reactive ion etching or other process. Furthermore, orientation-dependent etching is effected by ethylene diamine, and the distance between adjoining grooves is set to a proper size. Finally, the remaining narrow silicon-region between the adjoining grooves is heated and oxidized to be transformed into an oxide film so that the top silicon region is completely isolated from the substrate.
SUMMARY OF THE INVENTION
It is hence a primary object of this invention to present a method of manufacturing perfectly isolated, high-performance semiconductor devices.
This and other objects are accomplished by a method of manufacturing semiconductor devices, which comprises a process of forming a plurality of first openings in the surface of a semiconductor substrate, a process of forming an oxidation resistant film on the surface of the semiconductor substrate and in part of the side of the first openings to be connected thereto, a process of etching the semiconductor substrate exposed to the first openings by orientation-dependent process to form second openings, a process of forming an oxide film in the second openings using said oxidation resistant film as a mask, and a process of burying insulators into the first openings.
In a specific embodiment, the crystal plane orientation of the semiconductor substrate is {100}. The first openings are formed vertically to the surface of the semiconductor substrate. The oxide films buried into the adjoining second openings are connected with each other, and the second openings are formed by etching, using an etchant with the fastest etching speed on the plane with {100} orientation of the semiconductor substrate. As the etchant, potassium hydroxide, mixed solution of ethylenediamine and pyrocatechol, mixed solution of hydrazine and pyrocatechol, or their aqueous solution or mixed solution may be used. Furthermore, this invention may include a process of forming plural second openings differing in size. Besides, after the process of forming an oxidation resistant film, a process of forming an etching resistance film in the bottom of the first openings may be provided.
Moreover, this invention relates to a method of manufacturing semiconductor devices, which comprises a process of forming a plurality of first openings in the surface of a semiconductor substrate, a process of forming an oxidation resistant film on the surface of the semiconductor substrate and in part of the side of the first openings to be connected thereto, a process of forming an etching resistant film in the bottom of the first openings, a process of etching the semiconductor substrate exposed to the first opening side by orientation-dependent process to form second openings, a process of forming an oxide film in the second openings by using said oxidation resistant film as the mask, and a process of burying insulators into the first openings.
This invention has various advantages, among which are as follows.
(1) In the method of this invention, since orientation-dependent etching is employed in the process to form second openings of the semiconductor device, the precision of etching is excellent, and the thickness of the oxide film to be formed in the second openings may be kept to a minimum required limit.
(2) As a result, introduction of strains into crystals at the time of oxidation is controlled, and the reduction of active region due to invasion of oxide film is lessened.
(3) Besides, active regions differing in size can be obtained, since it is possible to form plural second openings differing in size.
(4) By forming an etching resistant film in the bottom of the first openings before forming second openings by orientation-dependent etching, the unnecessary etching of the first opening bottom may be prevented at the time of subsequent orientation-dependent etching, so that the surface may be flattened easily.
While the novel features of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 (a) to 1(e) are sectional views showing method of manufacturing a semiconductor device invented by us before reaching the present invention;
FIGS. 2 (a) to 2(j) are sectional views showing a first embodiment of this invention;
FIGS. 3 (a) to 3(e) are sectional views showing a second embodiment of this invention; and
FIGS. 4 (a) to (j) are sectional views showing a third embodiment of this invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is intended to illustrate the technology invented by us before reaching the present invention, as disclosed in the Japanese Laid-Open Patent No. 56-12749. To facilitate the understanding of the present invention, this technology is first described below. In FIG. 1 (a), numeral 10 is a silicon substrate, and 12 denotes a selectively opened oxidation resistant substance, for example, silicon nitride film. In FIG. 1 (b), using the silicon nitride film 12 as the mask, the silicon substrate 10 is anisotropically etched, for example, by reactive ion etching, to be opened nearly vertically, and openings 14 are formed. In FIG. 1 (c), a silicon nitride film 16 is formed on the entire surface. In FIG. 1 (d), the silicon nitride film 16 is removed by anisotropic etching, while the silicon nitride film 16 depositing on the side wall is not removed because it has been formed by anisotropic etching. In this state, the silicon substrate 10 is exposed to the bottom of the openings 14. Then, using these silicon nitride films 12, 16 as the mask, oxidation is effected to form an oxide film as shown in FIG. 1 (e). Meanwhile, as the optimum condition, when the distance of the active regions is narrowed, the oxide films 18 extended laterally will be mutually connected beneath the active region 20.
In this example, oxide films for separation can be formed at the sides and bottom of the active region, and it is effective to reduce the parasitic capacitance, but it was found to have the following problems as a result of researches.
(1) There is a limitation to the width W of the active region that can be isolated as shown in FIG. 1 (e). That is, a region of large width W and one of small width W' coexist on one substrate, the oxide films may not be joined at the bottom of the active region with large W after thermal oxidation. In an ordinary LSI, the fan-out of the peripheral transistors is greater than that inside the chip, and it is generally practiced to enhance the mutual conductance of the peripheral transistors by widening the gate width W.
(2) If it is attempted to oxidize sufficiently in the lateral direction in the lower part of the active region, the oxidation in the upward direction is similarly advanced, and the area of the active region is reduced.
This invention is intended to solve above-discussed technical problems. That is, this invention is to alleviate the limitation of the width of active region that can be isolated on a wafer, and to control the penetration of oxide film into the lower part of the active region at high precision so as to realize a semiconductor element suited to fine processing.
Several embodiments of this invention are described below.
[Embodiment 1]
FIG. 2 is a process sectional drawing showing a first embodiment of this invention. In FIG. 2 (a), numeral 22 is a silicon substrate with crystal plane orientation of 100. In this substrate, a thermal oxidation film 24 is formed in a thickness of 500 Å to 2000 Å, and a silicon nitride film 26 is deposited thereon in a thickness of about 1000 to 3000 Å by low pressure CVD method. Using a photoresist 27 which has been pattern-transferred by a known photolithographic method as the mask, the silicon nitride film 26 and pad oxide film 24 are etched. For this etching, it is preferable to employ a reactive ion etching (RIE) with a strong anisotropic property, but plasma etching or wet etching may be employed although the precision of pattern transfer is slightly inferior. In succession, as shown in FIG. 2 (b), the parts to become isolated regions of the substrate are selectively etched to form openings 28. The etching method is the same RIE with strong anisotropy, and the openings 28 are etched vertically. Then, after forming a thermal oxidation film 30 over the entire surface, the oxidation resistant film, such as silicon nitride film 32 is deposited by low pressure CVD. See FIG. 2 (c). Since the low pressure CVD process is excellent in coating performance, a homogeneous silicon nitride film 32 is formed on the side wall of the openings 28. Next, as shown in FIG. 2 (d), by the strongly anisotropic RIE, the nitride film is etched, while only the nitride film 32 on the side wall of the openings 28 are left over. Using the nitride films 26, 32 as the mask, the oxide film 30 on the bottom of the openings 28 are dry-etched, or wet-etched by using hydrofluoric acid compound solution, and the silicon substrate 22 is exposed in the area. Then, as shown in FIG. 2 (e), (f), part of the substrate surface is covered with photoresists 32, 34, and the silicon substrate with exposed openings 28 is etched by RIE. At this time, the depth of etching of silicon substrate 22 is determined by reversely calculating from the desired side etching extend in the later process. That is, it is because the side etching extend is proportional to the size of the silicon surfaces 36, 38 exposed to the side wall of the openings 28.
In consequence, as shown in FIG. 2 (g), the substrate 22 is etched in an alkaline aqueous solution, for example, potassium hydroxide (KOH), ethylenediamine pyrocatechol, or hydrazine pyrocatechol, and openings 40 are formed. The bottom and side wall of the openings 40 have a plane orientation of {100}, and the KOH solution has the etching speed faster by about two digits on the {100} plane of silicon substrate, than that on the {111} plane, so that the openings 40 are formed with a property of orientation-dependent etching. Meanwhile, the etching in the lateral direction of the side wall stops when the {111} plane intersects at 109.5°, and side etching in the upward direction does not occur. The depth of etching in the lateral direction is, supposing the depth of the exposed side walls 36, 38 to be 1, about 0.35. Then, as shown in FIG. 2 (h), the silicon nitride films 26, 32 are used as the mask for oxidation, and an oxide film is formed in the openings 40. At this time, by the width of active region, etching extent in the lateral direction and proper oxidation time, the oxide films 42 extending in the lateral direction of the openings 40 will be mutually connected in the lower part of the active region 44. Consequently, by the usual groove filling method, polycrystalline silicon films 48 are buried into the openings 28, and an oxide film 50 is formed on the polycrystalline silicon films by using the silicon nitride films 26, 32 as the mask as shown in FIG. 2 (i).
In this process, the structure of active region 44 being enclosed with oxide film is obtained. Meanwhile, since the openings 40 are formed by orientation-dependent etching of part of the substrate in the lower part of the active region 44, the controllability of etching extent is extremely high, and the amount of oxidation in the lateral direction required to connect the separate oxide films in the bottom of active region is small, and strains accompanying swelling of oxide parts are few, and the volume reduction of the active region is also small.
FIG. 2 (j) shows an example of CMOS integrated circuit formed in thus isolated active regions 44. Numerals 52, 54 are drain and source regions of n-channel MOS transistor, 56, 58 are drain and source regions of p-channel MOS transistor, 60 is a gate electrode, and 62 is an Al wiring. Since each transistor is enclosed with oxide film, there is no parasitic transistor which may cause latchup, and latchup does not occur. At the same time, since the PN junction area is small, the resistance to alpha-rays is improved. Besides, needless to say, since this integrated circuit has the periphery of its diffusion layer covered with a thick oxide film, the parasitic capacitance is small, and the conditions of integrated circuit of high speed and low power consumption are fulfilled.
[Embodiment 2]
FIG. 3 is a process sectional drawing showing a second embodiment of this invention. In FIG. 3 (a), numeral 64 is a silicon board of which crystal plane orientation is {100}. The parts to be isolated regions in the substrate are selectively etched, and openings 66 are formed. The etching method is the reactive ion etching with a strong anisotropic property, and the openings 66 are etched vertically. After forming a thermal oxidation film 68 over the entire surface, an oxidation resistant film, for example, a silicon nitride film 70, is applied by vacuum desposition process. Since the vacuum deposition is excellent in linearity, nitride film does not deposit on the side wall with greater depth than specified of the openings 66. A similar shape may be obtained also by using an oblique beam deposition process with excellent linearity. Using the silicon nitride film 70 as the mask, the oxide film 68 is etched, and the silicon substrate of the bottom and side wall of the openings 66 is exposed. See FIG. 3 (b).
Conforming then to the procedure of embodiment 1, as shown in FIG. 3 (c), the substrate is processed by orientation-dependent etching is alkaline aqueous solution, and openings 72 are formed. Then, as shown in FIG. 3 (d), oxidation is effected, and oxide films 72 are formed at the openings 72, and connected beneath the active region 76. By the usual groove filling method, the openings 66 are filled with polycrystalline silicon film 78, and an oxide film 80 is formed on the polycrystalline silicon film. See FIG. 3 (e).
In this process, the structure of active region 76 enclosed with oxide film is obtained.
[Embodiment 3]
FIG. 4 shows a process sectional drawing of a third embodiment of this invention. In FIG. 4 (a), numeral 82 is a silicon substrate with plane orientation of {100}, 84 is a thermal oxidation film, 86 is a silicon nitride film, and 88 is a CVD oxide film. By selectively opening only the parts to become isolated regions, the substrate is anisotropically etched by RIE to form vertical openings 90. Then, using the silicon nitride film 86 as the mask, a thermal oxidation film 92 is formed in the openings 90, and silicon nitride film 94 and CVD oxide film 96 are formed on the side wall of the openings as described in embodiment 1 as shown in FIG. 4 (b). The substrate 82 exposed in the bottom of the openings is anisotropically etched by RIE, and openings 98 are formed as shown in FIG. 4 (c). Next, a silicon nitride film 100 is formed on the entire surface by low pressure CVD as shown in FIG. 4 (d). By anisotropic etching by RIE, the silicon nitridre film is removed from the bottom of the openings, leaving the silicon nitride film 100 only on the side wall of the openings. See FIG. 4 (e)
In consequence, using the silicon nitride film 100 as the mask, the thermal oxidation film 102 is formed in the bottom of the openings as shown in FIG. 4 (f). When the silicon nitride film 100 is removed, the substrate is exposed at side wall of the openings 98 as shown in FIG. 4 (g). Then using the oxide films 96, 102 as the mask, the substrate is processed by orientation-dependent etching in an alkaline aqueous solution, and openings 104 are formed as shown in FIG. 4 (h). Then, by oxidation using silicon nitride films 86, 94 as the mask, oxide films 106 are formed in the openings 104 are connected in the lower part of the active region 108 as shown in FIG. 4 (i). Thereafter, by the usual groove filling method, the openings 98 are filled with polycrystalline silicon film 110, and an oxide film 112 is formed on-the-polycrystalline silicon film 110. See FIG. 4 (j).
Thus, the structure of active region 108 enclosed with oxide film is obtained.
In this embodiment, since oxide films 102 are formed in the bottom of the openings 98, only the side wall of the substrate openings is etched, and the etchings advanced until mutual {111} planes intersect with each other, and hardly move ahead thereafter, so that the controllability is excellent. On the other hand, the etching extend in the lateral direction is determined by the distance of the substrate exposed to the side wall of the openings 98, and it is about 0.35 times this distance. In addition, since etching is not done downward in the openings 98, the depth of the openings 98 after formation of the oxide film 106 may be smaller, so that the openings 98 may be easily filled up with polycrystalline silicon film.
While specific embodiments of the invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all modifications and changes as fall within the true spirit and scope of the invention | Disclosed is a method of isolating a transistor perfectly by employing a selective oxidation technology (LOCOS technology). More particularly, vertical openings are formed in the surface of {100} silicon substrate, and oxidation resistant films are formed of this surface and in part of the side walls of these openings. In succession, by etching with an etchant having an orientation anisotropy, dents are formed at high precision in the side walls of the openings. By oxidizing using the oxidation resistant film as the mask, an oxide film growing out from a dent in the opening side wall is connected with another oxide film growing out from an adjacent dent. The transistor thus formed in the active region of the silicon electrically isolated from the substrate is small in parasitic capacitance and may be formed into a small size, so that it possesses the features suited to VLSI, that is, high speed, low power consumption, and processability to high density integration. | 8 |
This Application is a Divisional of U.S. Ser. No. 13/698,102 filed May 17, 2011, which is Allowed; which is a 371 of PCT/US2011/036821 filed May 17, 2011, which claims the benefit of Provisional Application No. 61/345,224 filed May 17, 2010, which are incorporated herein in their entirety.
AREA OF THE INVENTION
The present invention relates to a process for the preparation of certain pyrimidinone compounds.
BACKGROUND
WO 01/60805 (SmithKline Beecham plc) discloses a novel class of pyrimidinone compounds, inter alia those substituted at N1.
The pyrimidinone compounds described in WO 01/60805 are inhibitors of the enzyme lipoprotein associated phospholipase A 2 (Lp-PLA 2 ) and as such are expected to be of use in therapy, in particular in the primary and secondary prevention of acute coronary events, for instance those caused by atherosclerosis, including peripheral vascular atherosclerosis and cerebrovascular atherosclerosis.
Several processes for the preparation of such pyrimidinone compounds are also disclosed in WO 01/60805, inter alia alkylation of the pyrimidinone nucleus. This process generally suffers from moderate yields due to the poor selectivity seen in the alkylation of the pyrimidinone nucleus. Preparation of such compounds is also disclosed in WO 03/16287. While this process achieves improved selectivity, it generally suffers from modest yield particularly in the disclosed regioiselective step.
The present invention provides particularly advantageous processes, not hitherto disclosed, for the preparation of some of the pyrimidinone compounds disclosed in WO 01/60805.
SUMMARY OF THE INVENTION
In a first aspect the instant invention provides a process for preparing a compound of formula (I):
wherein:
R a and R b together with the pyrimidine ring carbon atoms to which they are attached form a cyclopentyl ring;
R 1 is phenyl, unsubstituted or substituted by 1-3 fluoro groups;
R 2 is C (1-3) alkyl substituted by NR 5 R 6 ; or
R 2 is Het-C (0-2) alkyl in which Het is a 5- to 7-membered heterocyclic ring containing N and in which N may be substituted by C (1-6) alkyl;
R 3 is phenyl;
R 4 is phenyl unsubstituted or substituted by C (1-6) alkyl or mono to perfluoro-C (1-4) alkyl; and
R 5 and R 6 which may be the same or different are C (1-6) alkyl;
the process comprising carrying out one or more of the following reaction steps:
(a) treating a C (1-4) alkyl 2-oxocyclopentanecarboxylate with an alkali metal salt of glycine to form a compound of formula (A)
(b) cyclising a compound of formula (A) to form the hexahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid of formula (B)
by treating a compound of formula (A) with either (i) or (ii):
(i) a thiocyanate salt and
a) a haloalkylsilane and a proton source (such as water or alcohol), with heating, or
b) an anhydrous acid, with heating; or
(ii) trimethylsilylisothiocyanate, with heating;
(c) forming a thio-4-oxo-4,5,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid of formula (C)
where n is 0 to 3,
by a treating compound of formula (B) with a thio-alkylating reagent which is a benzyl derivative of formula (D)
where n is 0 to 3 and X is a leaving group, in the presence of an alkali metal base and/or an alkali metal carbonate;
(d) treating an aldehyde of formula (E)
with an amine, a heavy metal catalyst and hydrogen to form a secondary amine of formula (F)
and
(e) forming a compound of formula (I) by treating a compound of formula (C) with carbonyldiimidazole and the secondary amine of formula (F) and heating the mixture.
Also within the scope of this invention are the several intermediates used in the foregoing process for making compounds of formula (I), and processes of making such intermediates comprising one or more of the foregoing steps as indicated.
DETAILED DESCRIPTION OF THE INVENTION
For the purposes of this invention, C (1-6) alkyl (which may be alternatively referred to as (C 1 -C 6 )alkyl, including, e.g., C (1-4) alkyl or C 1 -C 4 alkyl) refers to a straight- or branched-chain hydrocarbon radical having the specified number of carbon atoms. For example, as used herein, the terms “C (1-6) -alkyl” refers to an alkyl group having at least 1 and up to 6 carbon atoms. Examples of such branched or straight-chained alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, isobutyl, n-butyl, t-butyl, n-pentyl, isopentyl, and n-hexyl, and branched analogs of the latter 3 normal alkanes.
Halo refers to fluoro, bromo, chloro or iodo. Where such a moiety is on an alkyl group, there may be 1 or more of any one of these four halo groups, or mixtures of them.
When the term “mono to perfluoro-C( 1-4) alkyl” is used it refers to an alkyl group having at least 1 and up to 4 carbon atoms that is substituted with at least one fluoro group on any or all of the carbons, and may have up to 2n+1 fluoro groups where n is the number of carbons. Examples include, but are not limited to, fluoromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, 2-(trifluoromethyl)ethyl, and nonafluoro-tert-butyl. Trifluoromethyl is a particularly useful group, especially when present at the 4 position on the R 4 phenyl ring.
With regards to the phenyl of R 1 , if it is substituted by fluoro there may be 1-3 fluoro groups on the phenyl ring at any combination of positions on the ring. Particularly useful are the 4-fluorophenyl, 3,4-difluorophenyl, 3,4,5-trifluorophenyl, or 2,3-difluorophenyl groups, more particularly the 4-fluorophenyl, 3,4,5-trifluorophenyl, or 2,3-difluorophenyl groups.
In regard to R 2 , suitable 5- to 7-membered heterocyclic rings containing N include pyrrolidine, piperidine and azepane.
C 1-6 (e.g. C 1-4 ) alcohols include branched or straight-chained alkanes having at least 1 and up to 6 carbons, and substituted by 1, 2 or 3 —OH groups. Examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, isobutyl, n-butyl, t-butyl, n-pentyl, isopentyl, and n-hexyl alcohols, and branched analogs thereof.
In some embodiments, the process is carried out in accordance with the following description.
In step (a), alkyl esters of 2-oxocyclopentanecarboxylate are available commercially. The methyl ester is particularly useful and readily available. The alkali metal salt of glycine may be the sodium, potassium or lithium salt, which are available commercially or prepared in situ from glycine and a suitable base such as sodium ethoxide. The sodium salt is particularly useful. The reaction is run in a polar solvent such as a low molecular weight aqueous alcohol (e.g. C 1-4 , e.g. ethanol, methanol, and/or isopropanol), an amidic solvent (e.g. N-methylpyrrolidinone) or a carboxylic acid (e.g. acetic acid). The reaction mixture is heated, e.g., to between 50°-70° C. for a sufficient, generally short time, e.g. a couple of hours or so, and is then worked up by conventional means to obtain the alkali metal salt of ({2-[(methyloxy)carbonyl]-1-cyclopenten-1-yl}amino)methyl ester or used in solution as is.
With regards to the cyclization step (b), making the hexahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid of formula (B), the alkali metal salt of formula (A) is treated with either:
(i) a thiocyanate salt such as ammonium thiocyanate or an alkali metal thiocyanate such as sodium thiocyanate, or potassium thiocyanate, and a) a haloalkylsilane and a proton source such as water or alcohol (e.g., C 1-4 alcohols, including e.g. methanol) in an appropriate solvent, such as an amidic solvent (e.g. N-methylpyrrolidinone) or a carboxylic acid (e.g. acetic acid), for a sufficient time, generally several hours, at elevated temperature such as between 80°-120° C.; or b) an anhydrous acid (inorganic or organic) such as anhydrous hydrochloric acid or methane sulfonic acid, with heating (such as in (a) above); or
(ii) trimethylsilylisothiocyanate, with heating (such as in (i) above).
Methods using the thiocyanate salt are particularly suitable. In such methods, treatment with the thiocyanate salt will generally be followed by treatment with the haloalkylsilane and proton source, or with anhydrous acid, although the reagents may be combined in any order. By any of the cyclization methods, after applying heat to the mixture, generally for several hours, it is cooled and the product isolated and purified by conventional means.
The thiol of formula (C) [step (c)] is prepared by treating the hexahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid with a thio-alkylating agent which is an unsubstituted or substituted benzyl moiety of formula (D). Formula (D) can have any suitable leaving group (X) which is exemplified by Cl, Br, I or an —OSO 2 R group where R is alkyl (e.g., C 1-6 ), perfluoroalkyl (e.g. trifluoromethyl) or an aromatic group (e.g. phenyl). Acid (B) is stirred in a suitable polar solvent, for example water and a low molecular weight alcohol, and then treated with organic or inorganic base. For example, an alkali metal base such as NaOH or KOH and/or an alkali metal carbonate such as Na 2 CO 3 or K 2 CO 3 is added. This mixture is maintained or heated at low temperature, e.g. 20°-50° C. and the benzyl derivative is added and heating is continued for a suitable time, generally a couple of hours. The product is recovered by conventional means; addition of a low molecular weight organic or inorganic acid (e.g., formic, sulphuric or phosphoric acid) may facilitate crystallization.
In step (d), the secondary amine (F) needed to form the amide group in formula (I) is prepared from an aldehyde (E) by treating the aldehyde with the appropriate substituted amine in the presence of a heavy metal catalyst such as palladium and hydrogen gas, in an appropriate solvent such as an aromatic solvent (e.g. toluene), a ketonic solvent (e.g. methylisobutylketone) or an alkyl acetate solvent (e.g. isopropyl acetate). Suitable amines are alkylene diamines of the formula (C 1-3 )NR 5 R 6 , where R 5 and R 6 are as defined in formula (I), and of the formula Het-C (0-2) alkyl in which Het is a 5- to 7-membered heterocyclic ring containing N and in which N may be substituted by C (1-6) alkyl. When hydrogenation is completed, the product is recovered by conventional means (it may be left and used in solution).
The last step, step (e) will typically comprise treating compound (C) with carbonyldiimidazole in an aprotic solvent, then combining the mixture with the amine (F) and heating the mixture. Thus, step (e) is suitably effected by first treating the thiol (C) prepared in step (c) with carbonyldiimidazole in an appropriate aprotic solvent such as an aromatic solvent (e.g. toluene), a ketonic solvent (e.g. methylisobutylketone) or C 1-6 alkyl acetate solvent (e.g. isopropyl acetate)and heating the solution. Alternatively, thiol (C) may be combined with the reagents in any order. This step forms an imidazole intermediate that is not isolated, but added as is to a solution of the secondary amine (F) prepared in step (d). This solution is heated to e.g., 80°-100° C. or thereabout until conventional testing shows the reaction has gone to completion. Product is isolated by conventional means. In alternative embodiments, the imidazole intermediate may be isolated for subsequent reaction with amine (F). It has been found that combined use of the carbonyldiimidazole and amine in this step desirably reduces or removes residual thio-alkylating agent (e.g. (D)) in the thiol (C) (in some embodiments, to less than 1 ppm (D)). In some embodiments, methanol is used as a solvent during isolation of the product and may improve yield and/or purity. The present invention encompasses a methanol solvate of compounds of formula (I), formed by isolation comprising the use of methanol as a solvent.
In one aspect, the invention relates to novel compounds of formula (A). In another aspect, the invention relates to a method of preparing a compound of formula (A), comprising the aforementioned step (a).
In another aspect, the invention relates to novel compounds of formula (B). In another aspect, the invention relates to a method of preparing a compound of formula (B), comprising the aforementioned steps (a) and (b).
In another aspect, the invention relates to a method of preparing a compound of formula (C), comprising the aforementioned steps (a), (b) and (c).
In another aspect, the invention relates to a method of preparing a compound of formula (I), comprising the aforementioned steps (a)-(c).
In another aspect, the invention relates to a method of preparing a compound of formula (I), comprising the aforementioned steps (a)-(e).
All publications (including but not limited to published patent applications and patents) referred to herein are incorporated by reference in their entirety.
EXAMPLES
Example 1
Preparation of Sodium ({2-[(Methyloxy)carbonyl]-1-cyclopenten-1-yl}amino)acetate
Glycine sodium salt (69.64 g, 1.02 eq) and industrial methylated spirits (“IMS”) (800 mL), a grade of denatured ethanol, were combined and stirred. Then water (40 mL) was added to the slurry. Methyl oxocyclopentanone carboxylate (100 g, 1.00 eq) was then added and the slurry heated to 60° C.±3° C. After 2 hrs the slurry was cooled to 20° C.±3° C. over 40 min, aged for 30 min then filtered. The cake was washed with industrial methylated spirits (2×200 mL), deliquored, then dried further at 70° C. in an oven under reduced pressure to yield the title compound as a white solid (139.8 g, 89%).
1 H NMR (d 4 MeOD) δ 1.80 (2H, quintet), 2.49 (2H, t), 2.56 (2H, t), 3.63 (3H, s), 3.75 (2H, s).
Example 2
Preparation of (4-Oxo-2-thioxo-2,3,4,5,6,7-hexahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid
Sodium ({2-[(Methyloxy)carbonyl]-1-cyclopenten-1-yl}amino)acetate (60 g) and sodium thiocyanate (26.6 g) were stirred in N-methylpyrrolidinone (280 ml) and water (2.94 ml) under a nitrogen atmosphere. Chlorotrimethylsilane (73.8 g) was added and the mixture heated to 117±3° C. After 3 hours at this temperature the reaction mixture was cooled to 90° C. and water (480 ml) was added. The mixture was cooled to 2° C. and the product isolated by filtration. It was washed with water (2×120 ml) then acetone (2×60 ml) and dried at 60° C. in an oven under reduced pressure to yield the title compound as an off-white solid (50.69 g, 83%). 1 H NMR (d 6 DMSO) δ 2.00 (2H, quintet), 2.60 (2H, t), 2.87 (2H, t), 4.95 (2H, broad s), 12.57 (1H, broad s), 13.26 (1H, broad s).
Example 3
Alternative Method for Making (4-Oxo-2-thioxo-2,3,4,5,6,7-hexahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid
Methyl 2-oxocyclopentanecarboxylate (750 g) was added to a stirred suspension of glycine, sodium salt (528 g) in N-methylpyrrolidinone (4 L) under a nitrogen atmosphere at 60±3° C. over 45 minutes. The ester was washed in with a further portion of N-methylpyrrolidinone (1.3 L) and the mixture was stirred at this temperature for 2 hours. The mixture was then cooled to 20±3° C. and sodium thiocyanate (599 g) was added. Chlorotrimethylsilane (2.01 kg) was added over 45 minutes and the reaction mixture was heated with a jacket set to raise the temperature to 123° C. over 45 minutes. During this heating up period, the reaction mixture became thicker and some volatiles were distilled out. The temperature of the reaction mixture rose to 117±3° C. This reaction temperature was maintained for 3 hours. The reaction mixture was cooled to 90±3° C. Water (10.5 L) was added and the suspension was cooled to 2±3° C. over 4 hours and the product was collected by filtration. The product was washed twice with water (2×2.3 L) and twice with acetone (2×1.2 L) and dried in vacuo at 60° C. to yield the title compound as an off-white solid (920 g, 77%); 1 H NMR (d 6 DMSO) δ 2.00 (2H, quintet), 2.60 (2H, t), 2.87 (2H, t), 4.95 (2H, broad s), 12.57 (1H, broad s), 13.26 (1H, broad s).
Example 4
Preparation of (2-{[(4-fluorophenyl)methyl]thio}-4-oxo-4,5,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid
(4-Oxo-2-thioxo-2,3,4,5,6,7-hexahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic add (30.0 g, 1.0 eq) was slurried in a mixture of water (162 mL) and isopropyl alcohol (30 mL). KOH solution (50% aqueous, 28.3 g, 1.90 eq) was added followed by a water line wash (15 mL) resulting in a solution. Then K 2 CO 3 (2.75 g, 0.15 eq) was charged and the solution was heated to 40±3° C. Thereafter 4-fluorobenzyl chloride (18.2 g, 0.95 eq) was added, followed by a line wash of isopropyl alcohol (18 mL) and the reaction mixture was stirred at 40±3° C. until the reaction was deemed complete ( ˜ 2.5 hours). The reaction mixture was cooled to 20±3° C. and formic acid (3.1 g, 0.5 eq) was added resulting in crystallisation of the product within 30 minutes. A second charge of formic acid (10.4 g, 1.7 eq) was added over 1 hour and the slurry was stirred at 20±3° C. for at least one hour. The slurry was filtered to isolate the product, which was washed twice with a mixture of water (48 mL) and isopropyl alcohol (12 mL), then with isopropyl alcohol (60 mL) and dried in vacuo at 50° C. to yield the title compound as an off-white solid (40.6 g, 92%). 1 H NMR (d 6 DMSO) δ 1.95 (2H, m), 2.57 (2H, t), 2.85 (2H, t), 4.4 (2H, s) 4.7 (2H, s), 7.15 (2H, dd), 7.45 (2H, dd), ˜ 13.0 (1H, vbrs).
Example 5
Preparation of N,N-diethyl-N′-{[4′-(trifluoromethyl)-4-biphenylyl]methyl}-1,2-ethanediamine
A mixture of 4′-(trifluoromethyl)-4-biphenylcarbaldehyde, (43.6 kg, 1.1 eq., see WO 01/60805), N,N-diethylethylenediamine (21.2 kg, 1.15 equiv.) and 5% palladium on charcoal (Degussa E101 N/W, 50% wet paste, 1.7 kg) in toluene (138 Kg) was hydrogenated at 20±3° C. and 50 psi until completion. The reaction mixture was filtered and the catalyst bed washed with toluene (2×36.7 kg). The solution was washed with water (84.8 kg) and concentrated under reduced pressure to ca. 85 L. This concentrate was used in the next step, Example 6, without further purification.
Example 6
Preparation of N-[2-(diethylamine)ethyl]-2-(2-{[(4-fluorophenyl)methyl]thio}-4-oxo-4,5,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-1-yl)-N-{[4′-(trifluoromethyl)-4-biphenylyl]methyl}acetamide
6a. A stirred slurry of carbonyldiimidazole (30.9 kg, 1.2 equiv.) in methylisobutylketone (255 kg) under nitrogen was heated to 70±3° C. (2-{[(4-fluorophenyl)methyl]thio}-4-oxo-4,5,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic add (53.0 kg) was added in a portionwise manner and the mixture stirred at 70±3° C. until no starting material remained.
6b. The suspension of imidazolide intermediate from 6a was added to a solution N,N-diethyl-N′-{[4′-(trifluoromethyl)-4-biphenylyl]methyl}-1,2-ethanediamine (see Example 5), washing in with methylisobutylketone (43 kg). The mixture was heated to 92±3° C. until complete conversion to the title compound was established. The reaction mixture was concentrated under reduced pressure to ca. 240 L and then cooled to 40 to 45° C. prior to the addition of methanol (105 kg). The solution was cooled to 20 to 25° C. to give a slurry, which was then heated to 50° C. and held for 30 mins. The slurry was cooled to 2±3° C. at 0.3° C./min and held for a further 30 mins. The product was isolated by filtration and washed with cold methanol (5±3° C., 2×168 kg) before being dried under reduced pressure at 47±3° C. to yield the title compound, intermediate grade as an offwhite solid (97.4 kg uncorrected for methanol; 90.9 kg corrected for methanol, 86%). 1 H NMR (CDCl 3 , ca 1.9:1 rotamer mixture) δ 0.99 (6H, t), 2.10 (2H, m), 2.50 (4H, q), 2.58/2.62 (2H, 2×t), 2.70/2.82 (2H, 2×t), 2.86 (2H, t), 3.28/3.58 (2H, 2×t), 4.45/4.52 (2H, 2×s), 4.68/4.70 (2H, 2×s), 4.61/4.93 (2H, s), 6.95 (2H, m), 7.31 (2H, d), 7.31/7.37 (2H, 2×m), 7.48/7.52 (2H, d), 7.65 (2H, m), 7.72 (2H, m).
Example 7
Alternative method for making (2-{[(4-Fluorophenyl)methyl]thio}-4-oxo-4,5,6,7-tetrahydro-1Hcyclopenta[d]pyrimidin-1-yl)acetic acid)
(4-Oxo-2-thioxo-2,3,4,5,6,7-hexahydro-1H-cyclopenta[d]pyrimidin-1-yl)acetic acid (20.0 g, 1.0 eq) was slurried in a mixture of water (112 mL) and isopropyl alcohol (20 mL). NaOH solution (50.9% aqueous, 13.82 g, 1.99 eq) was added followed by a water line wash (10 mL) resulting in a solution. Then Na 2 CO 3 (1.50 g, 0.16 eq) was charged and the solution was heated to 40±3° C. Thereafter 4-fluorobenzyl chloride (13.4 g, 1.05 eq) was added, followed by a line wash of isopropyl alcohol (12 mL) and the reaction mixture was stirred at 40±3° C. until the reaction was deemed complete ( ˜ 2.5 hours). The reaction mixture was cooled to 20±3° C. and formic acid (2.4 g, 0.6 eq) was added resulting in crystallisation of the product within 30 minutes. A second charge of formic acid (6.9 g, 1.7 eq) was added over 1 hour and the slurry was stirred at 20±3° C. for at least one hour. The slurry was filtered to isolate the product, which was washed twice with a mixture of water (32 mL) and isopropyl alcohol (8 mL), then with isopropyl alcohol (40 mL) and dried in vacuo at 50° C. to yield the title compound as an off-white solid (28.6 g, 97% th). 1 H NMR (d 6 DMSO) δ 1.95 (2H, m), 2.57 (2H, t), 2.85 (2H, t), 4.4 (2H, s), 4.7 (2H, s), 7.15 (2H, dd), 7.45 (2H, dd), ˜ 13.6 (1H, vbrs).
These examples are given to illustrate the invention, not to limit it. What is reserved to the inventors can be determined by reference to the claims below. | This invention relates to methods of making a compound of formula (I) and intermediates for same
the compounds of formula (I) being useful for treating cardiovascular and inflammatory diseases such as atherosclerosis. | 2 |
TECHNICAL FIELD
The present invention relates to a system for removing certain contaminants or impurities from well water by oxidation effected by the injection of air into a reaction chamber having first and second sections wherein the air is first mixed intimately with incoming water through the use of baffles that break up the fluid flow paths and where thereafter in, the second section of the reaction chamber, the baffles act to strip the previously aerated water of excess air and permit it to be vented, so that it does not enter the water distribution system.
BACKGROUND ART
It is well known that water drawn from wells usually contains a variety of impurities or contaminates. The most usual contaminates occurring naturally in well water are iron, sulfur and manganese, although many man-made contaminates are now also found. These mineral contaminates may cause stained plumbing fixtures and corroded pipes and in addition, may result in the presence of disagreeable odors and improper taste to the water.
Undesirable mineral content is removed from raw water by a variety of methods, although most of the methods involve treatment of the water with oxidizing substances. For example, removal of iron and manganese is commonly effected by running the water through a filter with a bed of minerals periodically regenerated with a chemical such as potassium permanganate to oxidize the dissolved metals forming either oxides or hydrates which are precipitated and removed in the filter. Another method that is widely used is that of injecting a quantity of oxygen, either as pure oxygen or more commonly in the form of air. Possibly the most widely accepted method for introducing air into well water is by means of air aspiration produced through use of a venturi orifice. Of a somewhat more limited use has been the direct injection of air under pressure into a body of water to provide the oxygen necessary to oxidize the metal ions for ultimate removal from the water.
A system illustrating the use of air aspiration to precipitate iron is shown in U.S. Pat. No. 5,096,580. In this arrangement, well water is drawn by means of a pump through a pipe and into a pressure tank. From that point, the water ultimately is directed, upon a demand basis to an oxygen induction device, which is in fact a venturi jet, that aspirates air into the water at that point. The induction of air created by the venturi orifice is located close to the filter tank so that build up of precipitated iron oxide or iron hydrates is prevented from occurring in the pipe.
In U.S. Pat. No. 3,649,532, water enters through an inlet and is passed through a venturi type air aspirator unit where it then continues to flow through a valve and to an inlet tube which is located on the interior of a filter tank. An automatic air release is provided in the upper portion of the tank to vent air and sulfur containing gases to the exterior. One problem encountered with this type of system results from the fact that the incoming air/water mixture are present together for a comparatively short time before being released into the interior of the tank and oxidation of the dissolved metal content is often inadequate to effect good cleansing of the well water.
A different sort of system is shown in U.S. Pat. No. 4,749,493. In this instance, an oxygen supply is introduced into the bottom of a column which contains a plurality of rings. The interior of the column is first filled with an oxygen supply and then water flows upwardly through a tube, exiting through a screen. The water then percolates downwardly through the rings acquiring oxygen from the oxygen enriched environment that had been initially placed in the column from the oxygen supply. In this apparatus, the oxygenated water is withdrawn through the discharge ports located in the bottom portion of the column. U.S. Pat. No. 4,695,378 shows an apparatus used for the purpose of treating acid mine water and involves the use of a pair of jet pumps using a venturi effect to provide aeration of the water. Following introduction of water through aspiration, the flow is then into a static mixer which has a helical interior that swirls the water and air to provide some additional mixing of the air and water. This aspiration describes a process for introducing air into acid mine water and performing a mechanical mixing operation but does not deal with the ultimate use of water for consumer use. Other patents which may be referred to are U.S. Pat. Nos. 3,649,533, 4,534,867, 4,659,463, 5,061,377, 5,096,596 and 5,147,530.
Technical Problem To Be Solved
While the processes that constitute the prior art recognize the use of air or oxygen introduction into water, for certain purifications, problems still exist. For example with systems utilizing venturi aspiration of air into water, the venturi devices are both difficult to maintain and to obtain the introduction of sufficient quantities of air into the water to effect complete oxidation of dissolved mineral elements. The venturi is a flow restrictor which limits water pressure to the end user or adds a load on the well pump. When oxidation does occur, depending upon the location where the air is aspirated, precipitation of mineral elements from solution can occur which can result in blockage and constriction of conveying pipes. No effective system is known in which sufficient oxidation is obtained by merely tumbling air and water together. In systems using air injection, unremoved excess air creates blockages and noises in plumbing systems.
The apparatus of the present invention provides an efficient, economical apparatus and system for dissolving substantial quantities of air (oxygen) into well water and also for removing excess oxygen that might otherwise result in transport difficulties. In addition, the present system insures that there is maximum physical interaction between the oxygen bearing air and the water so that thorough aeration of the water is accomplished to oxidize the maximum amount of dissolved mineral content. The apparatus further provides for continued agitation of the air/water mixture to result in the removal of excess air and to thereafter enable its venting to the exterior of the aerating reactor apparatus. Specifically, by providing a vent in an air/water reactor chamber at such a location that excess amounts of air can be present in a first section of the chamber while exhausting the excess air from a second section of the chamber.
DESCRIPTION OF THE DRAWING
The drawing shows a schematic layout of a mineral reduction system utilizing the iron reactor apparatus of this invention.
DESCRIPTION OF THE INVENTION
Generally, air injection into well water containing dissolved iron manganese and hydrogen sulfide is a method suitable for treating these contaminates if certain criteria is met. Specifically, the system should be maintained at a pH above 6.8, the air and water must be adequately mixed for a sufficient amount of time to oxidize the mineral content and the water containing the precipitants must then be filtered through a medium, such as BIRM™ to remove the particulate material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Generally, the principle components of the present system include a pressure tank 10 which is connected through pressure switch 11 to a source 12, such as a well pump. The pressure tank is used to accumulate water taken from the well and stored until it is needed for use. Pressure tank 10 is connected, as by means of pipe 13, to an inlet 14 located in the top of a vessel 20 which defines a reaction chamber 21. Also connected to inlet 14 is a source of pressurized air 25 which provides the air for introduction into the reaction chamber 21, through pipe 26.
It can be seen by referring to the drawing that the reaction chamber 21 is made up a substantially vertically disposed elongated body having an upper end 31 and a lower end 32, the lower end 32 having an outlet 33. The preselected length of the intermediate portion 35 of reaction chamber 21 is located about midway between the upper and lower ends 31, 32 of reaction chamber 21.
Contained within the reaction chamber 21 are fluid flow baffles 40 which are distributed as unsupported individual bodies substantially throughout the entire volume of the reaction chamber. These baffles conveniently take the form of perforated or hollow balls or spheres which are about one inch in diameter and may be constructed of a plastic such as polyethylene and polypropylene. The baffle elements are present to insure that two individual reactions take place within the reaction chamber. First, when the water is introduced into the upper section 31 of reaction chamber 21, it must flow over the surfaces of the baffle elements 40; thereby the water is exposed to the maximum effect of the air already present in the reaction chamber. As the water flows downwardly through the chamber 21 and into the lower section 32, the baffles then continue to turbulently mix air and water, but simultaneously separate the air from the water, the separated air migrating upwardly toward the air vent 50. Air vent 50 contains a valve 51 which permits release of the separated excess air from the second region within the reaction chamber 21. Valve 51 may be a one way valve that is normally open but which closes to preclude flow of water therethrough. The water then passes out of the reaction chamber through outlet 33 and, via pipe 55, goes into the iron filter 60. The iron filter 60 may contain a substance such as BIRM™ to further oxidize any remaining solute mineral as well as to filter out those that have precipitated from solution.
The iron reactor is intended to be used in a residential household with a well-pump system. The iron reactor operates in conjunction with the well pump system which provides pressure to the household plumbing. A typical well pump cycle begins when the well pump turns on at the lower pressure limit and stays on until enough water has been introduced to pressurize tank 10 for the upper pressure limit to be reached and the pump then turns off. The air pump 25 of the iron reactor system is wired directly to the same pressure sensitive switch 11 used by the well pump. When the well pump turns on, the air pump 25 also turns on. The air pump at this time delivering air to the reaction chamber 31 while water is being delivered to pressure tank 10. After well pump turns off, the air pump 25 also turns off but the reaction chamber is now charged with a fresh quantity of oxygen rich air. Subsequently as water is called for, it enters the upper section 31 of the iron reactor where the aeration baffles 32 first mix the air and water together and then it goes into lower section 32 for separation of the excess air from the water. | A system for removing iron from well water which, in addition to sources of air and water and an iron filter, has a reaction chamber wherein water containing dissolved iron is turbulently mixed with air and after oxidation of the water, excess air is removed through venting means located approximately midway between the ends of the reaction chamber. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to fuel delivery systems for engines, especially aircraft gas turbine engines, and, more particularly, to a dual function rapid shutdown and ecology system for such fuel delivery systems, which performs its function upon engine shutdown.
[0002] Two of the functions provided by the fuel control system of a gas turbine engine are fuel shutoff/turn-on and ecology fuel management. The first function, fuel shutoff/turn-on, may be manually commanded from the control system (for instance, by the pilot for aircraft applications), or it may be triggered automatically through an overspeed detection system provided by the engine's electronic control. In the later case, the response of the system must be extremely fast so as to limit the engine speed excursions above the normal operating range.
[0003] A second function of the fuel control system is ecology management, and requires that the fuel in the manifold be disposed of properly during shutdown and not be allowed to drain into the engine where it will vaporize and/or smoke when in contact with the still-hot combustion chamber, thereby creating atmospheric pollution. Also, after any type of shutdown, it is necessary that fuel remaining in the engine fuel manifold be removed rapidly to keep it from puddling. Fuel left in the manifold can cause hot starts upon subsequent engine operation and will also coke the engine's fuel nozzles, a condition which hinders nozzle performance, leading to premature failure.
[0004] An examination of prior art shows that there have been many and varied attempts to address one or both of the aforementioned fuel control system functions. Of particular interest in this regard are the following references and examples:
[0005] U.S. Pat. No. 4,206,595 discloses a system to collect fuel left over in the fuel manifold upon engine shutdown and reintroduce it on the next engine start. The system uses two check valves, two springs and two pistons to accomplish this function.
[0006] U.S. Pat. No. 5,809,771 teaches a system which uses flow divider differential pressure to remove fuel from the fuel manifold upon engine shutdown and which temporarily stores the fuel until the engine is subsequently restarted.
[0007] U.S. Pat. No. 6,195,978 B1, assigned to the assignee of this application, involves a system whereby fuel flow is reversed upon engine shutoff by adding one valve to the main fuel control and modifying the main fuel control pressurizing valve to include a pressure switch function. The invention is also directed toward gas turbine engines that include both primary and secondary manifold systems.
[0008] U.S. patent application Ser. No. 09/361,932, also assigned to the assignee of this application, discloses a fuel divider and ecology system adapted for engines requiring three discrete fuel manifolds. The ecology function is accomplished using one single chamber staged valve and modifying the main fuel control pressurizing valve to include a pressure switching function.
[0009] Various other prior art fuel systems have addressed fuel shutoff/turn-on concerns as well as ecology issues and have introduced various other techniques in an effort to control both problems. Examples include: draining fuel overboard after engine shutdown, blowing unburned fuel into and through the engine at shutdown, and draining unburned fuel into a tank that must be manually emptied.
[0010] None of the above cited prior art provide a single, simple, module that accomplishes the dual functions of rapid shutoff (or turn on) of fuel flow as well as ecology management.
SUMMARY OF THE INVENTION
[0011] The present invention accomplishes the dual function of rapid shutdown and ecology management in a single module operated by a single electromagnetic solenoid valve. In one aspect of the present invention, a cylindrically shaped valve body is provided to house a large spring loaded piston member, which when extended due to pressure differentials caused by actuation of the solenoid valve, provides sufficient volume to accommodate all fuel left over in the fuel manifold and distribution system at shutdown. Simultaneously, a secondary small piston member, which is housed internal to the underside of the large piston member, also actuates causing all fuel being delivered to the engine combustion chamber to be bypassed back to pump inlet.
[0012] In another aspect of the present invention, separate cylindrically shaped valve bodies are provided to house the large spring loaded piston member and the small piston member. This alternate embodiment is intended for use on fuel control systems employing low pressure differentials along various stages of the fuel control system manifold. The large spring loaded piston member extends at low pressure differentials caused by actuation of the solenoid valve, and provides sufficient volume to accommodate all fuel left over in the fuel manifold and distribution system at shutdown. A small accumulator, or alternatively a check valve, is provided to accommodate a small amount of fuel displaced upon actuation of the large piston member. Simultaneously, with actuation of the solenoid valve, the remotely located small piston member, also actuates causing all fuel being delivered to the engine combustion chamber to be bypassed back to pump inlet.
[0013] These and other objects, features and advantages of the present invention, are specifically set forth in, or will become apparent from, the following detailed description of embodiments of the invention when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a schematic and partial cross sectional representation of a gas turbine engine fuel control system, including an embodiment of the inventive rapid shutdown and ecology system, shown in its first position during engine operation;
[0015] [0015]FIG. 2 is a similar schematic and partial cross sectional representation of a gas turbine engine fuel control system, including an embodiment of the inventive rapid shutdown and ecology system, shown in its second position at engine shut down;
[0016] [0016]FIG. 3 is a schematic and partial cross sectional representation of a gas turbine engine fuel control system, including an alternate embodiment of the inventive rapid shutdown and ecology system, shown in its first position during engine operation; and
[0017] [0017]FIG. 4 is a similar schematic and partial cross sectional representation of a gas turbine engine fuel control system, including an alternate embodiment of the inventive rapid shutdown and ecology system, shown in its second position at engine shut down.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The following detailed description is for the best currently contemplated methods for carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention.
[0019] In order to fully appreciate this invention, it is best to describe the details of the component parts in connection with the operational modes of the gas turbine engine's fuel control system. In this light the descriptions that follow address both engine operation and shutdown modes for two embodiments of the inventive rapid shutdown and ecology system.
[0020] In FIG. 1, an illustrative gas turbine engine fuel control system 10 of a mostly conventional configuration known to those skilled in the art includes fuel supply 11 originating from fuel tanks (not shown) entering a low pressure fuel pump 12 , which increases the pressure in line 13 to level Po. Fuel then proceeds to high pressure pump 14 , which further increases fuel pressure to level P1 in line 15 , at which point it enters metering valve 16 for modulating the rate of flow from the fuel supply to the combustor atomizers (not shown). Fuel pressure in line 15 A downstream of metering valve 16 decreases to level P2 (by the setting of bypass valve 18 ) and thereafter further decreases to level P3 in line 22 after passing through pressurizing valve 21 , which controls and establishes a minimum pressure of fuel delivered to the combustor atomizers downstream of flow arrow 23 . The bypass valve 18 returns, via lines 19 and 20 , pump flow in excess of metered flow and also controls fuel pressure such that P1 is always higher than P3, usually about 25 psi or greater. Additionally, at low fuel flow rates, P1 will be additionally higher than P3 by the setting of pressure rising valve 21 . Orifice 19 A is provided on line 19 to create a damping pressure drop to stabilize bypass valve 18 . All functions of the gas turbine engine fuel control system 10 are commanded by the engine electronic control unit (ECU), which is not shown on the drawings, by repositioning the metering valve 16 .
[0021] The inventive rapid shutdown and ecology system 24 communicates with line 22 by means of line 25 , and is positioned to be downstream of pressure rising valve 21 and upstream of the combustor atomizers. It is comprised of a metallic cylindrically shaped valve body 26 internally bored to define valve chamber 27 having an upper end 28 and an a lower end 29 at the longitudinal extremities. A large piston member “B” 30 is movable along the longitudinal axis of the valve chamber 27 between upper end 28 and lower end 29 . The flat surface of large piston member “B” 30 at the upper end 28 is bored to form fuel cavity “B” 31 . The depth and diameter of said fuel cavity “B” 31 are sized to provide a scavenge volume sufficient to accommodate all fuel in the fuel control system 10 downstream of pressure rising valve 21 , when the large piston member “B” 30 has moved to the extreme of its stroke in the direction of lower end 29 . A spirally wound spring 32 is positioned along the axial periphery of fuel cavity “B” 31 , such that when compressed, one end bears on upper end 28 and the other end bears on the base of fuel cavity “B” 31 . Spring 32 is designed to remain fully compressed when fuel pressure Px in fuel cavity “A” 34 is sufficiently greater than P3, the pressure immediately downstream of pressure rising valve 21 . In other words, the difference between Px and P3 times the area of piston B must be greater than the load in spring 32 . O-ring seals 44 are provided at three circumferential levels to prevent fuel flow between the inner surface of valve chamber 27 and the exterior surface of large piston member “B” 30 when the latter strokes along the longitudinal axis of valve chamber 27 .
[0022] Small piston member “A” 33 is placed internal to a close tolerance cylindrically bored cavity 36 located along the longitudinal centerline of large piston member “B” 30 at lower end 29 . Small piston member “A” 33 may be equipped with an o-ring seat 45 to prevent any leakage of metered fuel during normal engine operation. Face plate 35 , secured to large piston member “B” 30 , interlocks small piston member “A” 33 within bored cavity 36 . Two fuel passages extending from bored cavity upper end 36 A provide communication with elements of the fuel control system 10 manifold as follows: Passageway 37 leads to annular cavity 37 A on valve body 26 , and then to line 38 , thus permitting free flow of fuel from downstream of metering valve 16 to small piston member “A” 33 at the bored cavity upper end 36 A. Fuel passageway 39 leads to annular cavity 39 A on valve body 26 , and then via line 40 to line 13 downstream of the low pressure fuel pump 12 . Electro-magnetic solenoid valve 41 , which is commanded by the ECU, connects line 40 with fuel cavity “A” at lower end 29 . On the opposite side of valve body 26 , line 42 connects fuel cavity “A” 34 with line 15 , immediately downstream of high pressure pump 14 . A small orifice 43 is provided on line 42 to establish a pressure drop from P1 to Px when solenoid valve 41 is open. For one embodiment, diameter 46 of large piston member “B” 30 is about 2.5 inches and stroke 47 is about 1.5 inches. Those dimensions will vary as a function of the specific gas turbine engine's fuel control system configuration.
[0023] Still referring to FIG. 1, the fuel control system is shown in its first position during engine operation. Solenoid valve 41 is closed and pressure in fuel cavity “A” 34 , Px, is equal to P1, which is always higher than P3 (by at least about 25 psi). Accordingly, large piston member “B” 30 is fully stroked toward upper end 28 , and spring 32 is fully compressed. Simultaneously, since Px is higher than P2, small piston member “A” 33 is fully stroked toward bored cavity upper end 36 A, thus preventing fuel flow from line 38 to line 40 . Therefore, during engine operation, the inventive rapid shutdown and ecology system remains inoperative.
[0024] Referring now to FIG. 2, there is shown the same gas turbine engine fuel control system schematic as in FIG. 1 with the exception that the embodiment of the inventive rapid shutdown and ecology system 10 is now shown in its second position at engine shut down. It is at this phase that it accomplishes its intended dual function of rapid shutoff (or turn on) of fuel flow as well as ecology fuel management.
[0025] When the gas turbine engine is shut down either by manual command from the control system (for instance, by the pilot for aircraft applications) or automatically through an overspeed, overtemperature or other fault detection system, the ECU opens solenoid valve 41 and shortly thereafter, when P2 falls below a predetermined level, pressure rising valve 21 closes. Closure of pressure rising valve 21 terminates fuel delivery to the combustor atomizers and opening of solenoid valve 41 immediately establishes a communication path between the upstream and downstream sides of high pressure pump 14 (via line 42 , fuel cavity “A” 34 , solenoid valve 41 , and line 40 ). Due to the pressure drop of orifice 43 , fuel pressure in fuel cavity “A” 34 , Px, thus drops to Po, causing spring 32 to shift large piston member “B” 30 to the extreme of its stroke in the direction of lower end 29 . This action increases the volume of fuel cavity “B” 31 thereby collecting all the fuel in the fuel control system 10 downstream of pressure rising valve 21 , and preventing it from draining into the engine creating atmospheric pollution and/or puddling, causing hot starts upon subsequent engine operation.
[0026] Simultaneously with the reduction of Px to Po, small piston member “A” 33 moves toward lower end 29 , thus establishing an open communication path between passageways 37 and 39 , annular cavity 39 A, and line 40 . In addition, as the pressure in lines 37 , 38 and 19 fall to the Po level the bypass valve 18 moves toward orifice 19 A. These actions cause all of the fuel being delivered to the chamber atomizers to be immediately bypassed back to the high pressure pump 14 inlet, either through the bypass valve itself or through piston “A” cavity upper end 36 A. The rapid shutoff of fuel flow to the engine has therefore been achieved.
[0027] When solenoid valve 41 is again closed by ECU command, the reverse process takes place. Fuel cavity “A” pressure Px increases to P1 forcing small piston member “A” 33 to move toward bored cavity upper end 36 A, closing passageway 39 and terminating the fuel bypass condition. Large piston “B” 30 also moves toward upper end 28 , compressing spring 32 , and forcing the fuel previously collected in fuel cavity “B” 31 to return to the fuel control system manifold downstream of pressure rising valve 21 . Rapid turn on of fuel flow to the engine has therefore been achieved and atmospheric pollution has been prevented.
[0028] On some gas turbine engine fuel control systems, the setting of bypass valve 18 is quite low and pressure rising valve 21 is referenced to Po rather than P2. Under those conditions, the difference between P1 and P3 is insufficient to compress spring 32 and hold large piston member “B” 30 fully stroked toward upper end 28 , as shown in FIG. 1. To accommodate those conditions and still provide the intended dual function of rapid shut down (or turn on) of fuel flow as well as ecology fuel management, another embodiment of the inventive rapid shut down and ecology system has been devised and is shown on FIGS. 3 and 4.
[0029] In FIG. 3, another embodiment of the inventive rapid shutdown and ecology system is shown in its first position during engine operation. The gas turbine engine fuel control system 10 is the same as that shown of FIGS. 1 and 2, and is comprised of the same conventional components, including low pressure fuel pump 12 , high pressure pump 14 , metering valve 16 , bypass valve 18 , pressurizing valve 21 , and various inter-communicating fuel lines, and all functions are commanded by the engine electronic control unit (ECU).
[0030] The other embodiment is comprised of two separately functioning subsystems, one for the ecology management function 48 A and another for the rapid shutdown function 48 B. The ecology management subsystem is shown to the right of view line A-A, and may be remotely located from the remaining fuel control system. It is comprised of a cylindrically shaped valve body 49 internally bored to define valve chamber 50 having an upper end 52 and an a lower end 53 at the longitudinal extremities. A large piston member “B” 51 is movable along the longitudinal axis of valve chamber 50 between upper end 52 and lower end 53 . The flat surface of large piston member “B” 51 at the upper end 52 is bored to form fuel cavity “B” 54 . The depth and diameter of said fuel cavity “B” 54 are sized to provide a scavenge volume sufficient to accommodate all fuel in the fuel control system 10 downstream of pressure rising valve 21 , when the large piston member “B” 51 has moved to the extreme of its stroke in the direction of lower end 53 . A spirally wound spring 55 is positioned along the axial periphery of fuel cavity “B” 54 , such that when compressed, one end bears on upper end 52 and the other end bears on the base of fuel cavity “B” 54 . Spring 55 is designed to remain fully compressed when fuel pressure Px, in fuel cavity “A” 57 , acting on piston diameter “A” 59 produces a force which is greater that the force produced by pressure P3 acting on the smaller piston diameter “B” 58 .
[0031] When large piston member “B” 51 is in contact with upper end 52 during engine operation, fuel leakage from P3 to Px is prevented by circumferential o-ring seal 56 and annular o-ring seal 60 . Under this condition, the small amount of fuel displaced into large piston annular cavity 66 is routed via fuel port 61 into a small, spring loaded, accumulator valve 62 where it is temporarily stored until engine shut down, at which time the spring load forces its return to fuel cavity “B” 54 . A “witness” drain 63 is provided to collect any inadvertent fuel leakage past accumulator valve 62 . An alternate embodiment involves use of a spring loaded check valve 64 in lieu of accumulator valve 62 . In such a case, the displaced fuel is released via line 65 to any fuel line, such as line 40 , having pressure Po.
[0032] For another embodiment of the ecology management subsystem 48 A, piston diameter “A” 59 is about 2.5 inches and piston diameter “B” 58 is about 2.0 inches, while stroke 51 A is about 1.5 inches. Those dimensions will vary as a function of the specific gas turbine engine's fuel control system configuration.
[0033] Still referring to FIG. 3, the rapid shutdown subsystem 48 B is comprised of a metallic cylindrically shaped valve body 67 internally bored to define valve chamber 68 and having an upper end 69 and a lower end 70 . A closely fitting cylindrically shaped small piston 71 placed internal to valve body 67 and is movable along the longitudinal axis of valve chamber 68 between the upper end 69 and the lower end 70 . An o-ring seal 72 is fitted along the periphery of small piston 70 to prevent fuel passage between upper 69 and lower 70 ends of valve chamber 68 .
[0034] The rapid shutdown subsystem 48 B communicates with the ecology subsystem 48 A and other elements of the fuel control system 10 by means of the following fuel lines: Line 73 is connected to line 15 downstream of high pressure pump 14 and leads to solenoid valve 74 (which is commanded by the ECU) and then to fuel cavity “A” 57 of the ecology subsystem 48 A. An orifice 75 is provided to create a pressure drop from P1 to PX when the solenoid valve 74 is open. Line 76 connects line 73 to valve body 67 , thus exposing the lower end 70 of small piston 71 to pressure P1. Line 77 connects to line 15 A and exposes the upper end 69 of small piston 71 to pressure P2, which is lower than P1. Finally, line 79 communicates between the upper end 69 of valve body 67 and line 13 , immediately downstream of low pressure pump 12 , which is at pressure Po, and line 78 connects line 79 to solenoid valve 74 .
[0035] The fuel control system as shown in FIG. 3 is in its first position during engine operation. Solenoid valve 74 is closed and pressure in fuel cavity “A” 57 , Px, is equal to P1 by virtue of fuel flow through line 73 . Accordingly, large piston member “B” 51 is fully stroked toward upper end 52 , and spring 55 is fully compressed. Simultaneously, since Px is higher than P2, small piston 71 is fully stroked toward the upper end 69 , thus preventing fuel flow from line 77 (pressure P2) to line 79 (pressure Po). Therefore, during engine operation, the other embodiment of the inventive rapid shutdown and ecology system remains inoperative.
[0036] Referring now to FIG. 4, there is shown the same gas turbine engine fuel control system schematic as in FIG. 3 with the exception that the other embodiment of the inventive rapid shutdown and ecology system 10 is now shown in its second position at engine shut down. It is at this phase that it accomplishes its intended dual function of rapid shutoff (or turn on) of fuel flow as well as ecology fuel management.
[0037] When the gas turbine engine is shut down either by manual command from the control system (for instance, by the pilot for aircraft applications) or automatically through an overspeed, overtemperature or other fault detection system, the ECU opens solenoid valve 74 and shortly thereafter, when P2 falls below a predetermined level, pressure rising valve 21 closes. Closure of pressure rising valve 21 terminates fuel delivery to the combustor atomizers and opening of solenoid valve 74 immediately establishes a communication path between the upstream and downstream sides of high pressure pump 14 (via line 73 , solenoid valve 74 , and lines 78 and 79 ). Fuel pressure in fuel cavity “A” 57 , Px, thus drops to Po, causing spring 55 to shift large piston member “B” 51 to the extreme of its stroke in the direction of lower end 53 . This action increases the volume of fuel cavity “B” 54 thereby collecting all the fuel in the fuel control system 10 downstream of pressure rising valve 21 , and preventing it from draining into the engine creating atmospheric pollution and/or puddling, causing hot starts upon subsequent engine operation.
[0038] Simultaneously, at rapid shutdown subsystem 48 B, with the reduction of Px to Po, small piston 71 moves toward lower end 70 , thus establishing an open communication path between line 77 and line 79 . In addition, as the pressure in lines 77 and 19 fall to the P0 level the bypass valve 18 moves toward orifice 19 A. These actions causes all of the fuel being delivered to the chamber atomizers to be immediately bypassed back to the high pressure pump 14 inlet, either through the bypass valve itself or through piston “A” cavity upper end 69 . The rapid shutoff of fuel flow to the engine has therefore been achieved.
[0039] When solenoid valve 74 is again closed by ECU command, the reverse process takes place. Fuel cavity “A” 57 pressure Px increases to P1 forcing small piston 71 to move toward upper end 69 , stopping flow through line 77 thus terminating the fuel bypass condition. On the ecology management subsystem, 48 A, large piston member “B” 51 also moves toward upper end 52 , compressing spring 55 , and forcing the fuel previously collected in fuel cavity “B” 54 to return to the fuel control system manifold downstream of pressure rising valve 21 . Rapid turn on of fuel flow to the engine has therefore been achieved and atmospheric pollution has been prevented.
[0040] The other embodiment also has the advantage that the ecology and rapid shutdown features can be separated, along line A-A of FIGS. 3 and 4, in the event the ecology function is not required, such as on military engines.
[0041] Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein. | A dual function rapid shutdown and ecology system for fuel delivery systems for engines, specially aircraft gas turbine engines, is disclosed. The dual function is accomplished in a single module operated by a single electromagnetic solenoid valve commanded by the engine electronic control unit. Upon actuation of the solenoid valve, a large spring loaded piston strokes to the extreme of its travel creating a cavity having a volume sufficient to accommodate all fuel leftover in the fuel manifold and distribution system at shutdown, thus preventing atmospheric pollution or engine damage upon subsequent operation. Simultaneous with actuation of the solenoid valve, fuel pressure differentials cause a small piston to stroke to the extreme of its travel opening fuel passageways and causing all the fuel being delivered to the engine combustion chamber to be bypassed back to pump inlet, thus effectively accomplishing the rapid shutdown function. An alternate embodiment allows for use of the dual function system on engines employing low pressure differentials along the various stages of the fuel control system manifold or where the ecology function is not required. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
Pursuant to 35 USC §120, this application claims the benefit of PCT/EP2006/010148 filed Oct. 20, 2006 which claims the benefit of German Patent Application No. 102005050638.0 filed Oct. 20, 2005. Each of these applications is incorporated by reference in its entirety.
TECHNICAL FIELD
An electrical component with ceramic layers made of different materials is described, as well as an electrical component module with a single ceramic base body, in which several sets of electrodes are arranged.
BACKGROUND
From DE 19931056B4, a multilayer varistor with internal electrodes is known, that has low capacitance.
From DE 10136545B4, a ceramic multilayer capacitor with internal electrodes is known.
SUMMARY
One problem to be solved lies in providing an electrical component whose base body contains several ceramic materials and can be sintered to form a monolithic body.
The problem is solved by an electrical component, which comprises a ceramic base body with several ceramic layers, wherein a function layer borders a composite layer, and the composite layer contains a zirconium oxide-glass filler mixture.
The electrical component operates preferably passively, by receiving only one signal magnitude, whereby with an applied voltage, a corresponding current is generated, or vice versa. An auxiliary power supply, for example in the form of a current supply, is not needed.
The composite layer preferably serves as a passivation or insulation and/or electrical insulation layer. Here, it can protect the function layer from external influences. If contacting means are contained in the composite layer, then the coupling capacitances between them can be reduced by the insulation property of the composite layer.
The composite layer also acts as a means for reducing or adjusting the parasitic capacitance of the function layer, by which means its influence on the printed circuit board on which the component is mounted can be reduced or adjusted.
It is advantageous for the composite layer to contain zirconium oxide since this material reacts poorly with other materials, for example those of the function layer, and therefore the electrical properties of the electrical component after the sintering together of the different layers can be adjusted or clearly predicted. As a result, the adjustment of the electrical characteristic curve of the component is facilitated. By means of the glass filler-containing composite layer, the formation of irregularities in the interface region with the function layer, such as the formation of cracks, is reduced, so that also for this reason the adjustment of the electrical characteristic curve of the component is facilitated.
The glass filler of the composite layer preferably contains zinc borosilicate (Zn—B—Si) or aluminum silicate.
The function layer contains a function ceramic and preferably has a higher dielectric constant than the composite layer. The function ceramic can contain a varistor, capacitor, NTC or PTC ceramic.
It is preferred that ZnO be used as the main component of a varistor ceramic. However, SiC can also be used. As a varistor, the electrical component is preferably used for voltage stabilization, transient voltage limitation as well as for surge protection.
Preferably, the capacitor ceramic primarily contains inorganic, nonmetallic or polycrystalline substances, such as TiO 2 (COG) or ferroelectric BaTiO 3 (X7R or Z5U), with or without barrier layers. As a capacitor, particularly a ceramic multilayer capacitor, the electrical component can be used, for example, in measurement and control technology, data technology, communications technology, in switched-mode power supplies, and in motor vehicle electronics.
As the main component of an NTC ceramic, it is preferred that Fe 3 O 4 , Fe 2 O 3 , NiO or CoO be used. An electrical component with a function layer of NTC ceramic is preferably used as the detector of a temperature sensor. Alternatively, it can be used for flow rate adjustment as well as for protection and compensation tasks.
As the main component of a PTC ceramic, it is preferred that BaTiO 3 or SrTiO 3 be used. An electrical component with a function layer of PTC ceramic is preferably used as part of a temperature sensor, thermostat, or for current stabilization.
The composite layer as well as the function layer can be mixed with organic binders to produce a slurry which can later be processed to form green films. The binder can be removed during the sintering of the layers to each other.
It is advantageous for the composite layer to present a lower dielectric constant than the function layer, which keeps the stray capacitance in the area of the composite layer as low as possible.
According to one embodiment of the electrical component, the function layer and composite layers are stacked alternately one on top of another. Here, the composite layers can form both the top and bottom parts of the component, so that the top and bottom function layers are each covered by a composite layer.
According to another embodiment of the electrical component, at least one internal electrode is arranged in or on the function layer. It is advantageous to provide internal electrodes in the component so that a particularly precise adjustment of the capacitance or the resistance of the component can be achieved.
Several internal electrodes can be connected by means of a contacting means to an external contact on the surface of the base body. An example of a contacting means here is a through-contact or a wire made of an electrically conductive material. It is advantageous for the contacting means to be fillable with a metal-containing material. Here, a continuous hole may be present in the ceramic materials, which is filled with a metal, or a via structure may be present, which is fillable with a metal.
According to another embodiment of the electrical component, at least one set of electrodes, consisting of at least two internal electrodes, is arranged in or on the function layer. A set of electrodes denotes an arrangement of several electrodes, together fulfilling a common function, such as the generation of an electric field in or on a dielectric. It can be a stack of several interconnected electrodes to which the same potential can be applied.
It is advantageous for the two internal electrodes to face each other and for the space between them to be filled with the material of the function layer. Several such sets of internal electrodes can be arranged next to each other in or on the function layer. The electrodes of each set can be made to contact each other by means of the contacting means. In this way, the capacitance and resistance of the component can also be adjusted particularly precisely. With such a structure, the function layer can contain a varistor ceramic so that the electrical component forms a varistor.
In addition, an electrical component module with a ceramic base body is proposed, which contains a ceramic function layer and a ceramic composite layer of the type described above and below, as well as several sets of internal electrodes. The sets of internal electrodes are arranged jointly in a single, monolithic ceramic base body next to each other. Each set of internal electrodes is preferably connected to the external connection assigned to it, and together with its associated external connection and the ceramic base body it forms an electrical component. Due to the arrangement of a plurality of such electrical components in a single, common base body, the resulting component can be called a component module.
It is preferable for the function and composite layers of the electrical component module to border each other. Here, they can be stacked one on top of the other.
According to one embodiment of the electrical component module, the composite layer can contain a zirconium oxide-glass filler mixture, so that a particularly good joint sintering with the function layer can be achieved.
According to one embodiment, a capacitor is formed between two internal electrodes with differing electric potentials in the plane of the electrical component. If the internal electrodes are arranged within the function layer which contains a varistor ceramic, a varistor section is formed between the internal electrodes. In particular, the section may be a varistor section between a ground electrode and an internal electrode, which receives a signal that has been applied to the electrical component via an external contact. A ground electrode of a function layer can be capacitively coupled to another internal electrode of the same layer. Each of the internal electrodes can in general function as a signal line.
According to one embodiment, an internal electrode of a function layer has a leg that faces an internal electrode that is adjacent to it, wherein the separation and thus the capacitance between the two internal electrodes in an area can be minimized. This occurs in the case of a given separation between the external contacts, which are in contact with the corresponding internal electrodes. Without changing the external structure of the electrical component or the conditions of contact to a printed circuit board, lower capacitance can be achieved between the internal electrodes of the function layer without having to change the separations between the external contacts.
According to a preferred embodiment of the electrical component, the internal electrodes of the function layer run partially into the interior of the electrical component and are connected at only one end to an external contact. Internal electrodes of different electrical potentials of the same function layer are here preferably adjusted to each other with regard to their dimensions. For example, a ground electrode of a function layer does not run deeper, or at least only slightly deeper or less deep, into the interior of the electrical component than an internal electrode of another electrical potential, which is adjacent to said ground electrode.
According to one embodiment of the electrical component, the composite layer also comprises an internal electrode. This has the advantage that the internal electrode generates low stray capacitances, while being capable of carrying currents that are carried by the internal electrodes of the function layer. In addition, this allows a reduction of the coupling capacitances.
Moreover, at least one internal electrode of the composite layer can function as a signal line, where it could be a ground electrode or a ground line which is connected to the same potential, such as a ground electrode of the function layer. The at least one internal electrode of the composite layer can advantageously reduce the coupling capacitance between two internal electrodes of the function layer. In particular, according to one embodiment of the electrical component, the at least one internal electrode of the composite layer can reduce the coupling capacitance between a ground electrode and another internal electrode of the function layer.
According to one embodiment of the electrical component, the internal electrode completely crosses the composite layer and is connected at each end to an external contact.
Each internal electrode of the electrical component, regardless of whether it is an internal electrode that is connected to or integrated in the function layer or a composite layer, can have one of the following shapes: square, rectangular, T-shaped, L-shaped, curved, meandering. It is preferred that a shape be chosen which allows the mutual approach of internal electrodes inside the function layer, thus reducing the capacitance between them. For example, it is advantageous for an L-shaped internal electrode to face with one of its legs an adjacent internal electrode in the same layer. Other internal electrode shapes employable for this purpose can, however, also be used without limitation.
According to one embodiment of the electrical component, several internal electrodes of a function layer and/or of a composite layer are shaped identically and form a mirror-symmetrical arrangement relative to each other.
It is advantageous for the function layer and/or the composite layer to be doped, such as to allow an exact adjustment of the electrical characteristic values.
The embodiments of electrical components described here are suitable particularly as electrical filters, for example, for use in computer housings or in cellular telephones and/or as electrical protection devices for protecting against transient voltage and/or overvoltages for electronic apparatuses.
DESCRIPTION OF THE DRAWINGS
The described objects are explained in greater detail using the following figures and embodiment examples. In the drawing:
FIGS. 1 a - 1 d show different layer structures of a ceramic base body,
FIG. 1 e shows an electrical component with a ceramic base body according to one of FIGS. 1 a - 1 d , particularly according to FIG. 1 a , with integrated internal electrodes,
FIGS. 2 a and 2 b show different perspectives of a varistor,
FIGS. 3 a - 3 c show different perspectives of an electrical component module,
FIG. 4 shows a graph for the representation of the sintering shrinkage of a varistor as a function of the glass content of the base body,
FIG. 5 shows a graph for the representation of the reduction of the capacitance of a varistor as a function of the glass content of the base body,
FIGS. 7 , 12 , 17 , 22 , 27 show perspective representations of different electrical components in the form of monolithically constructed arrays with several external contacts,
FIGS. 6 , 8 , 9 , 10 show cross sections of a first electrical component,
FIGS. 11 , 13 , 14 , 15 show cross sections of a second electrical component,
FIGS. 16 , 18 , 19 , 20 show cross sections of a third electrical component,
FIGS. 21 , 23 , 24 , 25 show cross sections of a fourth electrical component, and
FIGS. 26 , 28 , 29 , 30 show cross sections of a fifth electrical component,
A ceramic base body was tested in which zinc oxide was provided as the main part of a function layer and zirconium oxide as the main part of a composite layer, which were alternatingly stacked. During sintering of the base body, cracks formed in the boundary layer between the two layers. Porous boundary layers also formed, and in some cases, the base body failed to sinter.
It was discovered that there was a great difference between the sintering temperature and the sintering shrinkage of zinc oxide and other nonmetallic, inorganic ceramic materials, such as zirconium oxide (ZrO 2 — also called zirconium dioxide), and that this difference made it difficult to sinter these ceramic materials together.
It was also discovered that the above mentioned effects could be avoided or at least decreased by enriching the zirconium oxide with a glass filler component. Here, a glass filler component in a proportion of 5-30 wt % was admixed with the zirconium oxide, which resulted in the formation of an adhesive area between the two layers, and allowed the sintering together of the two ceramic materials or layers.
DETAILED DESCRIPTION
During the sintering process, the admixed glass filler component also adds as a buffer layer that compensates for the differing expansions of the ceramics. It was observed that:
(a) at high temperatures during the sintering process, the liquefied glass fills gaps between the different materials. This leads to a glass intermediate layer between the composite layer and the function layer. As a result, the formation or maintenance of cavities is suppressed or prevented, so that the electrical characteristic curves of the base body are not adversely affected. Because the glass is still plastic at higher temperatures, it is capable of reducing tensions between the layers by deformation.
(b) at moderate temperatures, the glass is sufficiently plastic to allow the formation of a sliding plane between the different layers. As a result, a mechanical means for tension reduction between the layers during the sintering process is created.
(c) at low temperatures during the cooling process of the base body after the sintering, the glass is so stable that no cracks occur in the composite layer.
The composite layer with a lower dielectric constant lowers the stray capacitance of the base body.
A composite layer is proposed which represents a mixture of a glass filler component and zirconium oxide, where glass is present in a proportion of preferably 5-30 wt %. The remaining portion must be assigned for the most part to zirconium oxide and to a lesser extent to organic material. Depending on the application and the desired capacitance or conductivity, this layer can be doped with Mg, Sb, B or Al.
The glass filler component contains preferably zinc borosilicate or aluminum silicate. It was found that these silicates present good compatibility with zirconium oxide and with zinc oxide, and consequently do not influence, or influence only slightly, by chemical reaction the electrical properties of the composite and function layers. However, the following materials or composition can also be used: Na 2 O.Al 2 O 3 .B 2 O 3 .SiO 2 , Na 2 O.BaO.SiO 2 , ZnO.B 2 O 3 .SiO 2 , SiO 2 .BaO.B 2 O 3 , Bi 2 O 3 .B 2 O 3 , B 2 O 3 .ZnO.Bi 2 O 3 , B 2 O 3 .ZnO, SiO 2 .B 2 O 3 .ZnO, B 2 O 3 .ZnO, SiO 2 .B 2 O 3 .ZnO.
Based on its composition with zirconium oxide, the composite layer has a particularly high thermal resistance. Thus, the use of such a composite layer has the advantage that the varistor does not burst when surge currents or a high voltage are/is applied to it, which abruptly heat the varistor. This applies particularly if the composite layer is embodied as the cover layer of a base body.
The function ceramic, on the other hand, can comprise a varistor ceramic, which results in the base body becoming the base body of a varistor. The varistor ceramic preferably contains zinc oxide, and it can be doped with such dopants as Bi, Pr or Sb, for example, to increase or to lower the permittivity of the varistor ceramic. However, the function ceramic can also contain another material that would be suitable, for example, for a ceramic multilayer capacitor or for an NTC or PTC element.
FIGS. 1 a - 1 d show a base body 1 of an electrical component in which a first layer 1 a is a function layer that contains a function ceramic, and in each case the top and bottom sides border a composite layer 1 b , which preferably has a lower dielectric constant than the first layer. The composite layer is preferably a passivation layer. The different layers are arranged alternately one on top of another and together form a sandwiched structure.
FIG. 1 a shows how the function layer 1 a is arranged between two layers of lower dielectric constant.
FIG. 1 b shows a base body with two function layers 1 a , the top and bottom sides of each of which border a composite layer 1 b of lower dielectric constant.
FIG. 1 c shows the base body according to FIG. 1 b , but with the lowermost composite layer 1 b omitted so that a function layer 1 a instead forms the bottom of the base body.
FIG. 1 d shows a base body in which the top and bottom sides of two composite layers 1 b each border a function layer 1 a . Here the function layers in each case form the top and bottom of the base body.
FIG. 1 e shows a ceramic base body which is provided with external contacts 4 that cover its side flanks. Such an external contact 4 can be applied in the same way to the base bodies shown in FIGS. 1 a - 1 d . Besides the external contacts 4 , electrodes 2 can be arranged in each base body. Here it is preferred for the input lines or the electrodes to be embedded in a function layer 1 a . However, it is also possible to arrange the input lines at least partially in the composite layer 1 b , in which the coupling capacitances can be kept low as a result of the insulation property of the composite layer between several input lines.
The manufacturing process of the base body preferably takes place as follows:
1. For the composite layer, a mixture of preferably doped zirconium oxide is prepared, most advantageously in the form of a powdered composition. This mixture then receives the admixture of a glass filler in a proportion of 5-70 wt %, preferably in a proportion of 5-30 wt %. For the function layer, a preferably doped ceramic mixture made of zinc oxide or another suitable material can likewise be prepared.
2. The powder compositions are shaped by means of a binder to green films with minimum required cohesion, and then dried. The binder can here contain water and organic material.
3. The dried green films, as needed, are stacked one on top of another to obtain a multilayered green base body.
4. If necessary, electrodes and contacting means are printed onto the ceramic layers or introduced into the ceramic layers. It is preferred that the electrodes be applied onto the desired layers with the thin layer technique, or screen printing in stacks, or with comb-like interdigitation. Suitable electrode materials are, for example, nickel or copper.
5. The green body is sintered in a reduced or unreduced atmosphere, where the binder, particularly its organic components, evaporates. As a result of the sintering process, the glass filler component forms a buffer layer between the different ceramic layers, so that they can be sintered to each other without the formation of cracks.
5a. During the sintering of the green base body (with or without electrodes or contacting means), the following first profile can be used, where organic components of the ceramic layers can be evaporated:
the heating of the green base body to 100° C. in steps of 5° C. per min, further heating to 450° C. in steps of 0.2-0.5° C. per min, further heating to 880° C. in steps of 5-10° C. per min, maintenance at 880° C. for 15 min to 1 h, cooling of the base body to −5 to −15° C. of room temperature.
5b. For a subsequent sintering process, the following second profile can be used, in which the ceramic layers of the base body are sintered jointly:
heating of the green base body to 1000-1100° C. in steps of 1-4° C. per min. maintenance at 1000-1100° C. for 180-240 min, cooling of the base body at −1 to −4° C. to room temperature.
5c. The sinter profiles can be selected as a function of the melting temperature of the electrodes or contacting means optionally present in the base body. Here it is preferred to choose a sintering temperature which is below the melting temperature of the electrodes or contacting means.
6. The sintered base body thus obtained is preferably provided over a large surface area with a metal external contacting layer. However, this step can also be carried out after the separation of the base body (step 7).
7. Depending on the application, the sintered base body can be separated, before or after it has received an external contact layer. For example, the base body is separated according to a grid defined by units of several adjacently arranged electrode stacks. After the separation, the result would be modules consisting of several sets of internal electrodes, where the sets of internal electrodes each would perform together with an external contact the function of an individual electrical component, for example, a varistor. If it has not yet received an external contact in the previous step, such a module can now receive an external contact with the desired pattern.
FIG. 2 a shows a perspective view of a varistor V with two external contacts 4 and a monolithic ceramic base body 1 , which consists of different ceramic layers 1 a and 1 b . The varistor is preferably an SMD varistor with low capacitance of less than 1 pF.
A plan view through the plane indicated by the broken line of this varistor V is shown in FIG. 2 b . Several, preferably four, internal electrodes 2 are arranged in the function layer 1 a , which can be contacted by means of contacting means 3 with the appropriate external contacts 4 assigned to these electrodes.
The aforementioned four internal electrodes 2 are preferably connected on one side by a surface to the composite layer 1 b , while being embedded on the other side in the function layer 1 a . In this way, two pairs of internal electrodes 2 are arranged in the base body, where, for each pair, a first internal electrode faces the second internal electrode, and the space between these internal electrodes of an internal electrode pair is filled with the function layer 1 a.
However, additional internal electrodes can be arranged within the function layer, so that several sets of internal electrodes with more than two internal electrodes per set are formed. The internal electrodes of a set can here be connected to each other by means of the contacting means 3 .
An example of a contacting means for contacting one or more internal electrodes to an external contact would be a metallic through-contact 3 , which can be filled preferably with silver, silver-palladium, silver-platinum, or simply platinum. Each through-contact passes here at least partially through the composite layer 1 b , so that the coupling capacitances can be considerably reduced with several through-contacts in the component.
FIGS. 3 a - 3 c show together an electrical component module from different perspectives. The component module comprises a ceramic base body, which presents several ceramic layers made up of different materials, beneath which a function layer comes in contact with a composite layer, and several sets of internal electrodes are arranged next to each other in the common ceramic base body. It is preferred that the composite layer have a lower dielectric constant than the function layer, and that the composite layer contain a zirconium oxide-glass filler mixture, so that the ceramic base body can be sintered particularly well to form a monolithic body.
If a varistor ceramic is used as the function layer, then the electrical component module can be called a varistor module. The same applies to the use of the alternative ceramic materials mentioned in the introduction.
FIG. 3 a shows how the surface of a base body is provided with external contacts 4 in a regular, preferably rectangular, arrangement. The surface is preferably the underside of the base body that will face the printed circuit board when the component is mounted on a board. A common ground contact GND is also arranged on the aforementioned surface of the base body, in the center of the arrangement of external contacts. Each external contact can be provided with a ball of solder 5 .
FIG. 3 b shows a cross section of the electrical component module EM, which is shown in the top view in FIG. 3 a , where the cross section corresponds to the course of the broken, stepped line shown in FIG. 3 a . With each external contact 4 or GND, a through-contact 3 , which preferably passes partially through the composite layer 1 b , is connected, which itself contacts one or more internal electrodes 2 . The latter can be connected to each other by means of the through-contact. Several sets of internal electrodes, each consisting of three internal electrodes 2 , are shown, where the individual internal electrodes are embedded in a single function layer 1 a . Each set of internal electrodes, whose internal electrodes are contacted by means of a through-contact 3 to an external contact 4 , forms, together with the ceramic layers, an electrical component, so that several electrical components can be arranged next to each other in a common base body. If here the function layer contains a varistor ceramic, then a varistor module can be devised. If, alternatively, a capacitor ceramic is used as function layer, the sets of internal electrodes mutually overlap in a comb-like fashion with their individual internal electrodes and are oppositely charged, a ceramic multilayer capacitor can be devised. Here, several sets of overlapping internal electrodes, which are connected to an external contact either directly or indirectly via a contacting means, together with the ceramic base body, can produce an arrangement of several capacitors, which are combined into one ceramic capacitor module.
Thus, in the varistor module or capacitor module, a total of 5 varistors or capacitors is contained with a common, monolithic base body, where a varistor or capacitor presents an external contact in the form of a ground GND common to all the varistors or capacitors.
FIG. 3 c shows a top view through the electrical component module EM. A cross-shaped external connection for the ground GND is shown, which is arranged on the underside of the component module. On the same underside, besides this cross-shaped ground electrode GND, the external contacts 4 (together with the solder balls 5 ) of the varistors or capacitors are arranged symmetrically. The broken-line circles in the figure indicate the contours of the solder balls 5 , the four squares show the cross sections of the internal electrodes 2 , and the filled, smaller circles the cross section of the through-contact 3 of each varistor or capacitor. Because the external contacts 4 present a cross section which is congruent with that of the solder balls, the external contacts are not represented in this figure.
FIG. 4 shows a graph representing the sintering shrinkage ΔL of a multilayered ceramic base body with two composite layers and an intermediate function layer as a function of the glass filler proportion GA in the composite layer 1 b . Without the addition of glass filler in the composite layer, the sintering of the ceramic base body results in sintering shrinkage, which is measured by using the enlargement produced by the lateral expansion of the base body, and is approximately 20%. The sintering shrinkage decreases approximately linearly as the amount of glass filler mixed with the composite layer is increased. With a glass filler content of 40 wt %, the sintering shrinkage of the ceramic base body was only approximately 9%.
FIG. 5 shows a schematic graph representing a comparison of the capacitance of several varistors A to D with different glass filler proportions in a zirconium oxide-containing composite layer (Z-G value) in contrast to the reference varistor R without glass filler. All the ceramic bodies of the varistors were sintered at approximately 1000° C. The varistors each present an electrode stack, where different varistors with different electrode separations were tested. These separations decreased after the sintering of the ceramic base body by up to 0.4 mm. If initially the separation between the electrodes was thus, for example, 0.12 mm, then the actual separation after sintering can be approximately 0.08 mm.
For the reference varistor R, the Z-G value is 0%. Its capacitance at a voltage of approximately 68 V is 2.3 pF.
For the varistor A, the Z-G value is 60%, so that its capacitance is approximately 0.6 pF.
For the varistor B, the Z-G value is 40%, so that its capacitance with unchanged voltage conditions is also approximately 0.6 pF.
For the varistor C, the Z-G value is 20%. At a voltage of approximately 115 V, it has a capacitance of approximately 0.78 pF.
For the varistor D, the Z-G value is 5%. At a voltage of approximately 116 V, it has a capacitance of approximately 1 pF.
In general, it can be seen that the capacitance decreases with increasing amounts of filler in the zirconium mixture.
In the context of this document, particularly with regard to all the aforementioned embodiments of the electrical component, the function layers can be doped with, for example, Bi, Pr or Sb. Here, a ceramic of the function layer, for example, a varistor ceramic, can be doped with these materials. Composite layers can also be doped with Mg, Sb, B or Al, for example. Here, the zirconium oxide-glass mixture can be doped specifically with these materials.
FIG. 6 shows a cross section of an electrical component 1 through section I (whose position is shown in FIG. 9 ). The cross section shows several, in particular 3, layers of different composition in a mutually superimposed, laminated or stacked arrangement. The planes II, III and IV are shown, where the plane II is located in an uppermost composite layer 1 b , the plane III in a middle function layer 1 a , and the plane IV in a bottommost, second composite layer 1 b . Cross sections of two internal electrodes 2 located in a plane within the function layer 1 a are shown, and a cross section of an internal electrode within the bottommost composite layer 1 b is shown. At least a part of the internal electrodes 2 of the bottommost composite layer 1 b is, in an orthogonal projection, directly under the middle internal electrode 2 of the function layer 1 a.
FIG. 7 is a perspective representation of an electrical component; some of its cross sections are shown in FIGS. 6 , 8 , 9 and 10 . On a lateral surface, or on a side surface of the electrical component, the arrangement of several external contacts 4 , particularly 3 external contacts, is shown. The latter can each contact several, particularly also mutually superimposed internal electrodes at the same electrical potential. The same number of external contacts can be arranged on the opposing side surface of the electrical component. It is also possible for external contacts to be arranged on a front surface that runs perpendicularly with respect to the side surface with the shown external contacts.
FIG. 8 shows the plane II, which was presented with FIG. 6 , of the uppermost composite layer 1 b , with no internal electrodes. The composite layer consists of a zirconium oxide-glass filler mixture.
FIG. 9 shows the plane III, which was presented with FIG. 6 , of the functional layer 1 a , showing the surface extents or geometries of the internal electrodes 2 located in this layer in the plane III. Two T-shaped internal electrodes face each other symmetrically, where a first axis of symmetry runs between these internal electrodes along their front surfaces and a second axis of symmetry runs through the legs of each T-shaped internal electrode. The base end of a leg of each T-shaped internal electrode approaches the surface of the electrical component or of the function layer, and it can therefore be or is contacted to an external contact, for example, as shown in FIG. 7 . The T-shaped electrodes are designed as ground electrodes or as ground lines that are connected to ground, and capable of diverting signals at certain frequencies. Next to each T-shaped internal electrodes, a longitudinal, rectangular internal electrode is arranged, whose one end approaches the surface of the electrical component and can be contacted to an external contact 4 . The other end of the internal electrode faces the interior of the component and ends there. The length of the internal electrode corresponds to the length of the T-shaped electrode. The rectangular internal electrodes are designed as signal lines to carry signals, for example, radio signals, and are each capacitively coupled to the ground electrode arranged next to it, whose function as signal diverting device is activated above a certain activation current or activation voltage. If the function layer presents a varistor ceramic of the described type, a varistor section is generated between each T-shaped ground electrode and a rectangular internal electrode located adjacent to it in the same the plane. The varistor section makes it possible, for example, to shunt surge currents or overvoltages, and signals below, within, or above a certain frequency range, in a controlled way, and divert them away from the ground electrodes.
Owing to its T-shaped form, the coupling capacitance between this internal electrode and the adjacent, longitudinal rectangular internal electrodes in the same plane, can be reduced. However, instead of the T-shape, other shapes are also conceivable, particularly those which allow a reduction of the separations between the boundaries of adjacent internal electrodes at different potential within a plane. An L-shape is possible here.
FIG. 10 shows the plane IV, which was presented in FIG. 6 , of the bottommost composite layer 1 b . This composite layer has an internal electrode 2 , which passes as signal line or ground line, transversely through the plane IV and is connected at each of its ends to an external contact 4 . Here, the same external contacts are contacted, which are connected to the T-shaped internal electrodes 2 of the function layer 1 a . A current carried by the T-shaped internal electrodes of the function layer is thus also carried by the ground line of the bottommost composite layer 1 b with lower stray capacitance.
FIG. 11 shows a cross section of another electrical component 1 through a section I (whose position is shown in FIG. 14 ). The cross section shows several, particularly 3, layers of different composition in a mutually superimposed laminated or stacked arrangement. The planes II, III and IV are shown, where the plane II is located in an uppermost composite layer 1 b , the plane III is in a middle function layer 1 a , and the plane IV in a bottommost, second composite layer 1 b . Cross sections of two internal electrodes 2 located in a plane within the function layer 1 a , a cross section of an internal electrode 2 within the uppermost composite layer 1 a as well as a cross section of an internal electrode 2 of a bottommost composite layer 1 b are shown. At least a part of the internal electrodes 2 of the uppermost composite layer 1 b lies, in an orthogonal projection, directly under the left, rectangular internal electrode 2 of the function layer 1 a . At least a part of the internal electrodes 2 of the bottommost composite layer 1 b lies, in an orthogonal projection, directly under the right, rectangular internal electrode 2 of the function layer 1 a.
FIG. 12 is a perspective representation an electrical component, some of whose cross sections are shown in FIGS. 11 , 13 , 14 and 15 . External contacts 4 , as already described with reference to FIG. 7 , can be formed.
FIG. 13 shows the plane II, which was presented in FIG. 11 , of the uppermost composite layer 1 b , which presents an internal electrode or signal line 2 in its left half, which completely crosses the plane and is contacted at each end with an external contact 4 at the same electrical potential. The composite layer consists of a zirconium oxide-glass filler mixture.
FIG. 14 shows the plane III, which was presented with FIG. 11 , of the function layer 1 a . Again, two T-shaped internal electrodes face each other symmetrically in the way shown in FIG. 9 and the associated description. Here too, the T-shaped electrodes are designed as ground electrodes or as ground lines which are connected to ground and can divert signals at certain frequencies. Next to each T-shaped internal electrode, a longitudinal, rectangular internal electrode is arranged in a way that corresponds to FIG. 9 and to the associated description. The functions of the T-shaped internal electrodes, of the rectangular internal electrodes as well as of their interactions in the sense of signal diversion correspond to the description with reference to FIG. 9 . The left internal electrode 2 of the function layer 1 a , however, works together with the signal line 2 of the composite layer in such a way that a current carried with low stray capacitance through the left, rectangular internal electrode 2 of the function layer 1 a , is also carried by the signal line of the function layer 1 a.
FIG. 15 shows the plane IV, which was shown in FIG. 11 , of the bottommost composite layer 1 b . The composite layer presents an internal electrode 2 , which, as a signal line, crosses the plane IV and is connected at each end to an external contact 4 . Here, one of the same external contacts is contacted, which is connected to the right internal electrode 2 of the function layer 1 a . A current carried by the right, rectangular internal electrode 2 of the function layer 1 a is thus also carried by the signal line of the bottommost composite layer 1 b with low stray capacitance.
FIG. 16 shows a cross section of another electrical component 1 through a section I (whose position is shown in FIG. 19 ). Sections of three internal electrodes 2 located in a plane III within the function layer 1 a as well as sections of two internal electrodes 2 within the uppermost composite layer 1 b are shown. The bottommost composite layer 1 b has no internal electrodes.
FIG. 17 is a perspective representation of an electrical component, some of whose cross sections are shown in FIGS. 16 , 18 , 19 and 20 . The electrical component can be formed with external contacts 4 , as already described in reference to FIG. 7 .
FIG. 18 shows the plane II, which was shown in FIG. 16 , of the uppermost composite layer 1 b , which in each case presents an internal electrode or a signal line 2 in a left and a right half. Both signal lines completely cross the plane and are connected at each end to an external contact 4 at the same electrical potential.
FIG. 19 shows the plane III, which was presented with FIG. 11 , of the function layer 1 a . Again, two T-shaped internal electrodes are in a mirror symmetrical arrangement opposite each other in a way corresponding to FIG. 9 as well as the associated description. Here too, the T-shaped electrodes are designed as ground electrodes or as ground lines which are connected to ground and can divert signals at certain frequencies. Next to each T-shaped internal electrode, on both sides, a longitudinal, rectangular internal electrode is arranged. Here, rectangular internal electrodes arranged in the left half and in the right half of the plane are in a mirror symmetrical arrangement opposite each other. The functions of the T-shaped internal electrodes, of the rectangular internal electrodes as well as of their interactions in the sense of signal diversion correspond to the description of FIG. 9 . In the case where the function layer presents a varistor ceramic, according to this embodiment example, however, two varistor sections are produced immediately on each side of a T-shaped ground electrode. As a result, not only is it possible to shunt higher voltage surges in a controlled way, but also several signals can be applied to the electrical component through a single side surface and at the same time be processed by it. Thus, a bidirectional construction is indicated. A current which is carried by two rectangular internal electrodes located in the left half is also carried by the signal line of the composite layer 1 b , which is located at least partially, in an orthogonal projection, above the rectangular internal electrodes. The same applies to the internal electrodes in the right half of the plane III of the electrical component.
FIG. 20 shows a bottommost composite layer 1 b of the electrical component without internal electrodes in the plane IV. The electrical component 1 could be mounted, for example, by means of the underside of this composite layer on a printed circuit board, which would make it more difficult for stray capacitances, with respect to the conductor plate or electromagnetic fields emitted by the conductor plate, to reach the active function layer or the active uppermost composite layer. Thus, the signals processed by the electrical component can be processed with less interference or the printed circuit board can be more effectively protected from the effects of voltage surges.
FIG. 21 shows a cross section of another electrical component 1 through a section I (whose position is shown in FIG. 24 ). A cross section of an internal electrode 2 located in the middle function layer 1 a , cross sections of two internal electrodes 2 within the uppermost composite layer 1 b as well as cross sections of two internal electrodes 2 of a bottommost composite layer 1 b are shown.
FIG. 22 is a perspective representation of an electrical component, some of whose cross sections are shown in FIGS. 21 , 23 , 24 and 25 . External contacts 4 , as already described in reference to FIG. 7 , can be formed.
FIG. 23 shows the plane II, which was presented with FIG. 21 , of the uppermost composite layer 1 b , which in each case presents an internal electrode or a signal line 2 in a left and a right half. Both signal lines cross the plane completely and are contacted at each end to an external contact 4 , which has the same electrical potential as the signal line connected to it.
FIG. 24 shows the plane III, which was shown in FIG. 21 , of the function layer 1 a . A T-shaped internal electrode 2 in the form of a ground electrode or ground line is shown, which presents a stem, whose end leads to an external contact 4 at a side surface of the electrical component for electrical contacting. Opposite the branch of the T-shaped ground electrode, which runs perpendicularly to the stem, at a separation, two rectangular internal electrodes are arranged, which are each contacted at one end to an external contact which is arranged on the side surface of the electrical component, which faces the external contact connected to the ground electrode. The rectangular internal electrodes are here at least partially, in an orthogonal projection, beneath the signal lines of the uppermost composite layer 1 b , which are arranged on the corresponding side halves. The functions of the T-shaped internal electrodes, of the rectangular internal electrodes as well as their interactions in the sense of signal diversion correspond to the description associated with FIG. 9 . In this case, two capacitive areas are formed between the one ground electrode and the rectangular internal electrode of the function layer.
FIG. 25 shows the plane IV, which was shown in FIG. 21 , of the bottommost composite layer 1 b . The latter is designed as the uppermost composite layer 1 b . This means that all the signal lines of the left half of the component, which are distributed over the three layers of the electrical component, are connected to common external contacts. Signals that are applied to a given half of the component are thus carried in each case simultaneously by three lines, which are connected to a single ground line.
FIG. 26 shows a cross section of another electrical component 1 through a section I (whose position is shown in FIG. 24 ). Sections of two internal electrodes 2 located in the middle function layer 1 a , sections of two internal electrodes 2 within the uppermost composite layer 1 b as well as a section of an internal electrode 2 within the bottommost composite layer 1 b are shown. FIG. 27 is a perspective representation of an electrical component, some of whose cross sections are shown in FIGS. 26 , 28 , 29 and 30 . Stripe-shaped external contacts 4 , as already described in reference to FIG. 7 , can be formed which contact the internal electrodes.
FIG. 28 shows the plane II, which was shown in FIG. 26 , of the uppermost composite layer 1 b . In each case two internal electrodes 2 or signal lines 2 , located in a right or in a left half of the component, are shown, which each completely cross the composite layer laterally and are contacted each at one end to an external contact 4 .
FIG. 29 shows the plane III, which was shown in FIG. 27 , of the middle function layer 1 a of the electrical component. The construction, arrangement and effects of the internal electrodes or signal lines 2 or T-shaped ground electrodes correspond to those of FIG. 9 and the associated description.
FIG. 30 shows the plane IV, which was shown in FIG. 26 , of the bottommost composite layer 1 b . An internal electrode 2 or signal line is shown, which laterally crosses the plane IV completely and is contacted to the same external contacts 4 as the T-shaped ground electrodes of the function layer 1 a . This means that the single signal line of the bottommost composite layer with small stray capacitance carries, together with the ground electrodes 2 of the function layer 1 a , signals or electrical currents, which can be reliably diverted. | An electrical component includes a ceramic base body. The ceramic base body includes several ceramic layers including a function layer and a composite layer bordering the function layer. The composite layer can include a zirconium oxide-glass filler mixture. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Canadian Application No. ______ filed Jan. 29, 2013 and entitled CONTAINER FOR HANDS-FREE LATCH AND LINKAGE ACTIVATION FOR ACCESS. The entire contents of said application is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to containers, and particularly refuse or recycling containers, which are resistant to animal access. The containers include a foot-activated latch and linkage which permits hands-free activation of a user access door and related chute opening into the container. Such containers have particular application in recreational areas where large animals, such as bears, endeavour to access any refuse within the container. Consequently, the basic structure is rugged, and able to withstand animal abuse while substantially eliminating access to the contents of the container.
[0003] Refuse or recycling containers often attract attention of animals, and consequently containers used in areas where wildlife is present must be able to withstand attempts by animals to gain access to refuse or other materials contained within the container. Various attempts to limit or prevent animal access have been employed, including weights, locks and concealed latches. However, such devices have also posed additional difficulties for users of the containers, inevitably requiring exact handling and manipulation by users.
[0004] One successful animal resistant container, manufactured by the Applicant herein under the trade-mark HID-A-BAG includes a latched hinged lid. The latch is recessed under a covering on the lid, and must be raised beneath the covering in order to release the lid. This requires a user to rotate his/her hand, palm upwards, to raise the latch within the enclosure. Many animals, particularly including bears, do not have a rotatable wrist and cannot operate such a latch. Nonetheless, such device requires manual manipulation by a user.
[0005] Many other latches, either hand or foot operated, involve a simple release movement such as depressing a lever pedal or push rod. The present invention is an interlocked foot-operated latch and linkage which opens a user access door, thereby leaving a user's hands free for access to the container. While foot-operated pedals and linkages are known to open container lids, such as a common kitchen waste basket, such devices are also operable by any downward pressure as may be exerted by an animal. The present invention provides a latch with an interlocked foot pedal, which inhibits simple downward pressure as may be exerted by an animal, thereby substantially preventing operation by an animal such as a bear.
[0006] The present invention provides a hands-free, foot-operable latch and linkage to open a container access door for a user, which is self-latching upon release of the foot pedal.
[0007] Further, the hands-free access for deposit of material into the container avoids manual contact with the container or user access door, thereby avoiding potential contamination of a user's hands from surfaces which may harbour bacteria or germs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a container, embodying the latching system of the present invention, in a closed condition;
[0009] FIG. 2 is a perspective view of a container, embodying the latching system of the present invention, in a user access door in an open position, and the main service door open to illustrate the interior linkage;
[0010] FIG. 3 is a schematic view of the linkage with the user access door closed;
[0011] FIG. 4 is a schematic view of the linkage with the user access door open;
[0012] FIG. 5 is a detail of the lower latch linkage;
[0013] FIG. 6 is a schematic view of the upper linkage;
[0014] FIG. 7 is a schematic view of the foot pedal in latched position;
[0015] FIG. 8 is a schematic view of the foot pedal in operated position;
[0016] FIG. 9 illustrates a latch spring;
[0017] FIG. 10 is a side elevation view of the latch and linkage in a closed position of the access door;
[0018] FIG. 11 is a side elevation view of the latch and linkage in an open position of the access door; and
[0019] FIG. 12 is an overlay of the latch and linkage in the closed and open positions of FIGS. 10 and 11 .
DETAILED DESCRIPTION OF THE INVENTION
[0020] As may be seen from FIGS. 1 and 2 , a refuse or recyclables container 1 is illustrated. The container has a user access door 2 , which rotates outwardly under operation of the latch and linkage of the present invention. A service door 3 may be opened to gain access to the enclosed storage compartment to permit placing and removal of a refuse/recyclables storage bag contained on a frame (not shown) or similar bin within the container. A separate latch (not shown) retains service door 3 in a closed position.
[0021] A latch recess 4 contains the activating mechanism for the linkage. As may be seen in FIG. 5 , the latch activating mechanism includes a kick plate or bumper 6 , which is connected to a pair of support arms 8 affixed to pivot rod 10 . A spring retainer 12 mounted across support arms 8 rests against a torsion spring 14 , which biases the arms 8 and kick plate 6 towards the front of the container. From the aforesaid arrangement, as may be seen in FIGS. 7 and 8 , kick plate 6 may be rotated rearwardly in the direction of arrows ‘A’ against the action of torsion spring 14 . Support arms 8 include a step lock 16 , which extends forwardly to support a pedal locking pin 18 , mounted on the underside of foot pedal 20 . A foot pedal 20 extends rearwardly into recess 4 and is attached to a pedal pivot 22 . A linkage actuating lever 24 extends vertically from the rear portion of foot pedal 20 at the pedal pivot 22 . As may be seen from FIG. 8 , when kick plate 6 is pushed rearwardly by the toe of a user, pedal step lock 16 is disengaged from under pedal locking pin 18 , permitting foot pedal 20 to be depressed. As may again be seen in FIGS. 5 , 7 and 8 , depression of foot pedal 20 allows it to rotate about pedal pivot 22 , causing the upper end of actuating lever 24 to move accurately forward within the confines of the container.
[0022] Referring now to FIG. 6 , the upper portion of the access door activation linkage is illustrated. Actuating lever 24 is rotationally connected at 25 to a generally horizontal lower link 26 , which in turn is rotationally connected at 27 to a generally vertical pivoting lever link 28 , which is pivotable about pivot 30 . Pivot 30 is fixed to the adjacent interior side wall of container 1 . The upper end of pivoting lever 28 is rotationally connected at 31 . A generally horizontal upper link 32 is pivotally connected at 33 to a bell crank type activating bracket 34 , which in turn is rigidly fastened to a rearward flap 36 of access door 2 . Front flap 38 of access door 2 , in conjunction with rear flap 36 forms a chute permitting refuse to be discharged into the interior of container 1 . Door 2 , comprising flaps 36 and 38 , pivots about a door hinge 40 which joins the door 2 to the container structure. Flaps 36 and 38 are oriented at an angle of approximately 120 degrees in one embodiment of the invention but the angle may vary depending on the usage.
[0023] A spring 42 connects above pivot 30 to pivoting lever link 28 at one end, and at the other end 43 is connected to a forward portion of the adjacent side wall of container 1 to bias the upper end of pivoting lever link 28 forwardly to normally maintain the access door 2 in a closed position. Alternatively a biasing spring may be connected below pivot 30 , operating in the opposite direction. Still further, both an upper spring 42 and a lower spring could be utilized for greater biasing force.
[0024] As may be seen from FIGS. 5 , 7 and 8 , in operation of the latch and linkage for hands-free access to the container, a user first manipulates the kick plate 6 , rotating arms 8 and plate 6 rearwardly about pivot rod 10 in the direction of arrow A against the bias of torsion spring 14 , thereby disengaging pedal step lock 16 and permitting foot pedal 20 to be depressed. As previously noted, depression of foot pedal 20 allows it to rotate in the direction of arrow B about pedal pivot 22 , causing the upper end of actuating lever 24 to be moved forwardly. Referring now to FIGS. 6 , 10 to 12 , when the upper end of actuating lever 24 is moved forwardly, lower link 26 , connected to the lower end of pivoting lever 28 , moves that end of the lever 28 forwardly. Forward motion of the lower end of lever 28 pivots the lever about pivot 30 and moves the upper end of lever 28 rearwardly against the bias of spring 42 . The upper end of pivoting lever 28 is connected at 31 to upper link 32 , which is connected to and draws the activating bracket 34 rearwardly causing access door 2 to pivot into an open position about door hinge 40 . A user may then insert refuse into the chute area, defined by flaps 36 and 38 .
[0025] Release of the user's foot from pedal 20 allows return spring 42 to draw the upper end of pivoting lever link 28 forwardly, thereby closing access door 2 . The linkage moves to draw actuating lever 24 rearwardly, pivoting foot pedal 20 into the starting latched position. At the same time, torsion spring 14 returns support arms 8 and kick plate 6 to the start position, with pedal step lock 16 re-engaging pedal locking pin 18 to prevent opening of user door 2 .
[0026] The novel combination of interlocked kick plate 6 and foot pedal 20 establishes a lock or latch which prevents operation of the linkage and activation of the user access door until properly sequentially activated. Such interlock inhibits operation by animals, particularly bears. Furthermore, the constraining size or aperture of latch recess 4 prevents access by a wide foot, such as that of a bear, further inhibiting animal activation of the latch and linkage.
[0027] While the basic latch and linkage mechanism of embodiments of the invention have been set out above, it will be appreciated that the precise form of latching elements may be varied, while still maintaining the principle of interlocked kick plate and foot pedal before the linkage may be actuated to propel the user access door into an open position for hands-free access. For example, the kick plate may be positioned on a biased slider, rather than pivot. The linkage above the actuating lever may be replaced by a direct connection to the actuating bracket or the linkage may be provided by a Bowden cable.
[0028] A container embodying such a linkage may include a shield plate inside the container to prevent interference between bagged refuse and the access door linkage. As well, the front service door may be latched in any preferred form, or may employ a full hasp and lock.
[0029] While preferred embodiments of the invention have been illustrated, variations as would be understood by a person skilled in the art may be employed and are included within the scope of the invention as the appended claims are purposively construed. | The invention pertains to a foot operated latch and linkage means permitting hands-free access to a waste or recycling container. The latch includes a kick plate which is interlocked with a foot pedal whereby displacement of the kick plate permits release of the foot pedal to move from a latched position to an unlatched position, which pedal movement engages a linkage which opens a user access door in the container. | 1 |
FIELD OF THE INVENTION
[0001] This invention relates to an optical light transmitting component including a network of cells containing filler material, the cells being walled on the sides and unwalled on the top and bottom portion of each cell, the walled sides comprising a polymer having a first refractive index, and the cells comprising a filler material having a second refractive index greater than the first refractive index.
BACKGROUND OF THE INVENTION
[0002] Video display screens are commonly used in television (TV) for example, and typically use cathode ray tubes (CRTs) for projecting the TV image. In the United States, the screen has a width to height ratio of 4:3 with 525 vertical lines of resolution. An electron beam is conventionally scanned both horizontally and vertically in the screen to form a number of picture elements, i.e. pixels, which collectively form the image. Color images are conventionally formed by selectively combining red, blue, and green pixels.
[0003] Conventional cathode ray tubes have a practical limit in size and are relatively deep to accommodate the required electron gun. Larger screen TVs are available, which typically include various forms of image projection against a suitable screen for increasing the screen image size. However, such screens have various shortcomings including limited viewing angle, limited resolution, and limited brightness and typically are also relatively deep and heavy.
[0004] Various configurations are being developed for larger screen TVs that are relatively thin in depth. These include the use of conventional fiber optic cables in various configurations for channeling the light image from a suitable source to a relatively large screen face. However, typical fiber optic thin projection screens are relatively complex and vary in levels of resolution and brightness.
[0005] When viewing any type of video display screen, image contrast is an important parameter that affects viewing quality. To achieve high contrast in all ambient lighting conditions, it is necessary that the viewing screen be as dark as possible. This enables the actual black portions of the image to appear black. The manufacturers of conventional television cathode ray tubes have been trying to develop screens which appear darker or blacker for improving picture quality. However, it is impossible for direct view CRTs to actually be black because they utilize phosphors for forming the viewing image, with the phosphors themselves not being black.
[0006] U.S. Pat. No. 5,625,736 discloses an optical display that includes a plurality of stacked optical waveguides having first and second opposite ends collectively defining an image input face and an image screen, respectively, with the screen being oblique to the input face. Each of the waveguides includes a transparent core bound by a cladding layer that has a lower index of refraction for effecting internal reflection of image light transmitted into the input face to project an image on the screen, with each of the cladding layers including a cladding cap integrally joined thereto at the waveguide second ends. Each of the cores are beveled at the waveguide light inlet side so that the cladding cap is viewable through the transparent core. Each of the cladding caps is black for absorbing external ambient light incident upon the screen for improving contrast of the image projected internally on the screen. The formation of this waveguide requires numerous manufacturing and assembling steps. There remains a need for an improved means of forming a waveguide.
[0007] U.S. Pat. No. 6,307,995 discloses a flat planar waveguide with a gradient refractive index within the core. The core material has an index of refraction which decreases as the distance from the central plane increases. The decrease in the index of refraction occurs gradually and continuously. While this disclosure provides an improved means to minimize problems with decrease in efficiency, performance, and quality resulting from the light loss from the discreet bounces that the light undergoes in the optical waveguides of step index cladding type, and reduces the deleterious effects of chromatic dispersion when using optical waveguides of step index cladding type, it is still required that thin layers of material be coated and then stacked and glued together. There is a large opportunity for problems in the selection of materials and during manufacturing when stacking many layers together. Problems such as dust and dirt as well as air bubbles can cause spot defects or poor layer to layer adhesion. There remains a need for improved materials and means of forming waveguides for rear projection applications.
[0008] Outside the area of waveguides, optical panel and rear projection display screens, various processes for bonding thermoplastic films to non-woven webs or other thermoplastic films as well as making formed three-dimensional films are known in the art. For example, the Raley U.S. Pat. No. 4,317,792 relates to a formed three-dimensional film and the method for making such a film. In addition, the Merz U.S. Pat. No. 4,995,930 relates to a method for laminating a non-woven material to a non-elastic film. In U.S. Pat. No. 6,303,208, it is disclosed an elastomeric breathable three-dimensional composite material and the process for producing the same. The three dimensional composite structure is formed through vacuum extrusion to make a plastic apertured film and is used for elastic breathable medical and hygiene applications. There is no mention of using the three-dimensional apertured for optical purposes. U.S. Pat. No. 6,255,236 relates generally to elastic laminates, and more particularly to a laminate having an elastic polymer film core with at least one layer of an extensible nonwoven web bonded to each side of the elastic polymer film core, and having one or more substantially inelastic, non-extensible regions located in the laminate. Furthermore U.S. Pat. No. 6,242,074 discloses a composite material having improved cloth-like texture and fluid transfer properties. In one embodiment, the composite material has a polymeric film with a plurality of apertured protuberances and a plurality of loose fibers coupled to the polymeric film, including at least a portion of the sidewalls of the protuberances. In another embodiment, the composite material has a polymeric film with first and second layers, a plurality of apertured protuberances extending through both layers, and a plurality of loose fibers coupled to the first layer and to at least a portion of the sidewalls of the protuberances. As noted in these patents, the use of a three-dimensional formed film has been used for a number of personal care and fluid retention. There remains a need for improved materials and means of forming waveguides for rear projection applications.
[0009] Accordingly, an improved thin or flat panel optical screen for use in a projection TV or large format display, for example, is desired.
[0010] In U.S. Pat. Nos. 6,120,026 and 5,254,388 it is disclosed a means of forming a directional viewing screen using micro louvered film with clear areas of a first coefficient of extinction separated by louvers and an outer region adjacent to the clear region having a second coefficient of extinction. The means of making the microlouvers involves the formation of a billet that is thermally fused together and then a thin veneer cut is removed from the billet. Other layers are then attached to the veneer cut film. Such a process to form a screen requires coextrusion of a multi layer film, punching, fusing, cutting, smoothing, laminating and coating. It is a long tedious and expensive means of making a screen. In addition U.S. Pat. No. Re. 27,617 (Olsen) teaches a process of making a louvered light control film by skiving a billet of alternating layers of plastic having relatively lower and relatively higher optical densities. Upon skiving the billet, the pigmented layers serve as louver elements, which, as illustrated in the patent, may extend orthogonally to the resulting louvered plastic film. U.S. Pat. No. 3,707,416 (Stevens) teaches a process whereby the louver elements may be canted with respect to the surface of the louvered plastic film to provide a film that transmits light in a direction other than perpendicular to the surface of the film. U.S. Pat. No. 3,919,559 (Stevens) teaches a process for attaining a gradual change in the angle of cant of successive louver elements.
PROBLEM TO BE SOLVED BY THE INVENTION
[0011] There continues to be a need for improved optical elements such as those useful in a waveguide or privacy screen and simplified processes for making them.
SUMMARY OF THE INVENTION
[0012] The invention provides an optical light transmitting component including a network of cells containing filler material, the cells being walled on the sides and unwalled on the top and bottom portion of each cell, the walled sides comprising a polymer having a first refractive index, and the cells comprising a filler material having a second refractive index greater than the first refractive index, whereby light may be transmitted through the filler material and the unwalled top and bottom portion of the cells. The invention also provides a process for preparing such a component and a display device including such a component.
ADVANTAGEOUS EFFECT OF THE INVENTION
[0013] This invention provides a superior rear projection waveguide. and privacy screen. Specifically, it provides a waveguide and privacy screen that are simpler to manufacture
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 depicts the top view of a walled network
[0015] [0015]FIG. 2 depicts a single cell of a multi-wall network with an open aperture
[0016] [0016]FIG. 3 depicts a single cell of a multi-wall network with transparent filler
[0017] [0017]FIG. 4 depicts a wall network with lenslet array on one side
[0018] [0018]FIG. 5 depicts a rectangular shaped network
[0019] [0019]FIG. 6 depicts a three-dimensional view of a walled network
[0020] [0020]FIG. 7 depicts a three-dimensional view of an individual walled cell
[0021] [0021]FIG. 8 depicts a microlouvered privacy screen
[0022] [0022]FIG. 9 depicts a stacked waveguide
DETAILED DESCRIPTION OF THE INVENTION
[0023] As used herein, the following terms have the meanings designated::
[0024] “Aperture” shall mean an open area that allows light to pass through.
[0025] “Transparent” shall mean having a % transmission of from 80 to 100%.
[0026] “Clad” shall mean a clear layer adjacent to the transparent core of a waveguide.
[0027] “Clad cap” shall mean the black adhesive layer next to the clad layer
[0028] “Microlouver” shall refer to the linear section of a privacy screen that absorbs light and reduces off angle viewing in the plane approximately 90 degree to the microlouver directional alignment.
[0029] “Walled network” shall mean a series of joined three-dimensional cells of any shape and shall have at least one layer.
[0030] “Cell” shall mean an individual three-dimensional walled element having at least one wall.
[0031] “Open cell” or “aperture” shall mean the open area in the walled network that only contains ambient room gas such as air.
[0032] “Lenslet array” shall mean any non-planar shape or shapes that may be used to change the direction of light
[0033] The invention has numerous advantages over the prior art for making laminated stepped waveguides for display screens. The means of forming a laminated stepped waveguide as disclosed in U.S. Pat. Nos. 5,625,736; 6,002,826; and 6,307,995 involves coating at least 2 to 4 layers onto an optically clear film. The layers have a lower refractive index than the optically clear film plus an opaque adhesive clad cap layer. Methods of assembly involve slitting wide web into thin webs, chopping strips to a predetermined length and then stacking the strips one on top of the other and then fusing the layers together to form a screen. For a 50″ diagonal screen this might involve stacking and fusing several hundred or even thousands of strips. Other methods involve sheeting the coated film stacking and fusing the sheets in a block and then cutting a screen from the fused block of plastic. Various cutting methods may be used, but the process is very slow and usually results in an uneven surface that then needs to be ground and polished which can take hours or days. The grinding and polishing steps are very difficult and may result in scratches and digs into the surface of the plastic. The grinding and polishing steps also result in heat generation that can soften the adhesive between core layers and cause non-uniformities in the layer to layer interface. Another problem with stacked waveguides is that any thickness non-uniformities in the core film layer or the coating can result in an additive high or low spot when stacked on top of each other. The non-uniformity is magnified when pressure is applied to fuse the strips or sheets together. This can result in non-uniform pressure across the stack and therefore result in variable adhesion problems. Additionally in the formation of the stacked waveguide screens, it is necessary to have some depth to the screen. This may be in the order of 250 to over 500 mils in depth. This is required in order to provide a means of controlling ambient room light. As light from off angle enters the waveguide it is desirable to absorb the light in the black opaque layers. By providing adequate depth to the waveguide screen, some ambient light absorption is achieved.
[0034] Additionally in the formation of privacy screens there is also a need to provide adequate depth to the screen but in the order of 15 to 50 mils. The privacy screens have a microlouver feature that is physically similar to the clad and opaque layer of the stacked waveguides. The fundamental difference is that privacy screens have two layers with varying amounts of light absorbing material whose clear areas have a higher coefficient of extinction than the louvers while the waveguide has two layers one of which has a lower refractive index to provide total internal reflection of light that enters the waveguide within the critical angle and a second layer of black light absorbing material. In the formation of these privacy screens a multi-layer film with the desired layers is punched into a round disc and then stacked one on top of the other and then heat and pressure fused into a billet-like log. The billet is then veneer cut into sheets of the desired thickness. Subsequence functional layers are then either coated or laminated to the veneer cut sheet to form a privacy screen.
[0035] Manufacturing both laminated waveguides and privacy screens involve several steps including coating film, cutting, slitting, punching and fusing. Additional smoothing steps may also be required. It may also be necessary to laminated or coat other layers to the screens to provide improved viewing enhancements. By forming an interconnected walled network of polymer that has apertured cells in a one step vacuum extrusion or thermoforming process and then filling the open cells with a clear polymer material; a screen can be easily made. In either process more than one layer can be formed into a three-dimensional shape. The more desirable process is to provide at least two layers. In the case of a display screen the wall next to the open area is a clear polymer with a lower refractive index than that of the transparent filler polymer and the second wall is a black filled polymer that provides a high level of opacity. In the case of a privacy screen, there is a need for two layers of wall. The layer adjacent to the filled apertured has a lower coefficient of extinction and is usually filled with a low level of light absorbing material such as carbon black or dye. The second wall layer is a very opaque and is more highly filled with carbon black or dye than the first louver. In both cases the pre-formed wall network provides a mold that has the light reflecting or absorbing properties required for either the waveguide screen or privacy screen. By filling the open cells within the network, a usable screen is quickly formed. For privacy screens the network walls are thinner than those needed for rear projection screens. These and other advantages will be apparent from the detailed description below.
[0036] [0036]FIG. 1 depicts the top view of a walled network 20 .
[0037] [0037]FIG. 2 depicts a single cell of a multi-wall network 30 that has an outer wall 32 that is a light absorbing wall of filled polymer and an inner wall 34 that is clear for a waveguide screen and lightly filled for a privacy screen and open aperture 36 .
[0038] [0038]FIG. 3 depicts a single cell of a multi-wall network with transparent filler 41 that is made up of an outer wall 40 that is black and opaque and an inner wall 42 that is adjacent to transparent filled aperture 44 . Inner wall 42 has a lower refractive index than the transparent filled aperture 44 for a waveguide but for a privacy screen inner wall 42 has a lower coefficient of extinction than transparent filled aperture 44 . Typically the clear area has a coefficient of extinction that is at least 1.5 time that of the louver that is adjacent to the clear area.
[0039] [0039]FIG. 4 depicts a wall network with lenslet array on one side 51 and is made up of transparent filled individual multi-wall cells 52 and lens array 54 . Lens arrays may be on one or both sides of the network and may be either an integral part of the network or attached as a separate sheet.
[0040] [0040]FIG. 5 depicts a rectangular shaped network 61 that is made from a series of individual cells 63 that comprise an outer wall 60 , and inner wall 62 and filled aperture 64 .
[0041] [0041]FIG. 6 provides a three-dimensional view of walled network 70 with wall 72 and open aperture 74 .
[0042] [0042]FIG. 7 provides a three-dimensional view of a single open apertured cell 80 with cell length distance 82 , cell width 88 and cell depth 86 .
[0043] [0043]FIG. 8 depicts a privacy screen 90 which is formed using a heat fusion process in which a billet is made and then a veneer cut of film, approximately 10 mils thick, is shaved from the billet. The basic construction referred to herein is made up of transparent core 92 , first coefficient of extinction layer 94 that contains a low level of light absorbing material such as carbon black and second layer 96 that is more highly filled with light absorbing material than layer 94 . Fused veneer cut layers 92 , 94 and 96 are subsequently laminated with film 100 and is attached to the veneer cut film by adhesive layer 98 . Coating layer 102 may be applied to layer 100 before or after lamination. Layer 94 and 96 form microlouvers that help to restrict the viewing angle.
[0044] [0044]FIG. 9 depicts a stacked laminated waveguide 110 that is made up of multiple individual waveguides 112 . Each individual waveguide is made from a transparent core 118 and clear clad layer 116 that has a lower refractive index than the transparent core and a opaque adhesive layer 114 that is used to hold the structure together and also to absorb ambient room light.
[0045] In an embodiment of this invention an optical component contains a walled network of filled cells comprising walls containing a polymer having a first refractive index and, bounded by the walls, a filler containing a material having a second refractive index. Such an optical component has many uses and has advantages over prior art material such as stacked waveguide. The wall network screens can be made in a couple of manufacturing steps. The basic framework of the network may be formed by vacuum extrusion or weaving fibers together to form an array of individual cells that form a three-dimensional network. The walled network can then be filled with a transparent core material. Such a construction may be used for a waveguide. It may also be used as a display screen with a light inlet and viewing surface. The walled network or woven fiber have a three-dimensional shape to them, which is useful to control or absorb ambient light. Ambient light can cause the projected image to appear “washed-out” and interferes with the viewing pleasure of the display. The prior art screens are formed by coating several layers of lower refractive index materials and adhesive on each side of a clear transparent polymer core such as polycarbonate or polymethyl methacrylate. The outer-most layers are typically opaque and have adhesive properties. Rolls are then either slit into thin ribbons or sheeted and subsequently stacked and fused together. To form a display screen for rear projection TV it requires several thousand layers be stacked and fused. This process has many problems and is very labor intensive. Furthermore the stacked laminated waveguide screens are typically structurally weak. This is avoided if the walled network described above is used to make the screen.
[0046] In an embodiment of this invention, the formation of the walled network optical components that can be used as a waveguide has one or more layers and a filled transparent core in which the first refractive index of the wall adjacent to the filled core is lower than the second refractive index of the filled core. Typically it is desirable to have a difference of between 0.005 and 0.2 refractive index units between first refractive index polymer and the second refractive index material. In order to waveguide light there needs to be a difference in refractive index between the core and the adjacent wall layer. Below 0.005 there is little or no value for waveguiding while differences greater than 0.2 have a very high acceptance angle of light entering the waveguide such that ambient light is projected back into the projection side of the screen. High acceptance can also result in viewing limitations of the screen. The most desirable range of refractive index difference between the first refractive index material and the second refractive index material is from 0.01 and 0.02. Above 0.02 requires more expensive polymers to achieve while below 0.01 have limited usefulness for totally reflecting light internal within the core of the waveguide.
[0047] While it is possible to build a three dimensional walled network with one layer in which the single wall is opaque and also has a lower refractive index than the filled core, it is desirable to have a network with at least one layer to improve the overall efficiency of the screen. With more than one layer it is possible to provide at least one clear layer of lower refractive index material and an opaque layer that is capable of absorbing light. Having a clear clad layer or lower refractive index material next to the filled core is more efficient for reflecting light back into the filled core. When the opaque layer is next to the filled core, there is some light loss due to scattering and therefore the overall efficiency of the optical component is reduced.
[0048] In the case of a multi-walled network the opaque wall may also be black. Black material such as dyes and pigments including carbon black may be used. Ideally it is desirable to have the black opaque layer with a percent transmission of zero but for most applications it is sufficient to have the opaque material with a percent transmission of from 1-30 percent. While below 1% transmission is achievable it become very costly to highly fill the polymer and if the particles of black material are not properly dispersed, large agglomeration may be formed that will cause light scattering. If the transmission percent is too high for the opaque wall, light may be transmitted through it into the next filled core. Typically transmission percents greater than 30 will result in some light leakage into other filled cores of the networks.
[0049] Materials that are useful in the construction of walled network include polyolefin, polyester, polyamide, polycarbonate, cellulose acetate and copolymers thereof.
[0050] In the formation of multi-walled networks it may be desirable to use different materials for each wall. This provides a broader selection of materials to obtain a difference in refractive index or other properties such as wetting of the wall and adhesion with said filler. Useful materials for the filler of the walled network should have a percent transmission of between 80 and 100%. Below 80 percent transmission tend to have lower optical clarity and therefore have lower overall optical efficiency. While 100% is the highest transmission that can be achieved, it is recognized that all material will absorb or scatter some small amount of light.
[0051] In one embodiment of this invention the walled network is formed with polyolefin. Polyolefins are desirable because they are easily formed into networks and the polymer is readily available. In another embodiment the wall network is made with polyester. Polyester is desirable because it is a tougher polymer and typically stiffer than other polymers. Improved stiffness is desirable in the final screen formation and may be less prone to screen sagging.
[0052] In other embodiments the walled network may be made with polycarbonate. Polycarbonate is a very tough polymer and is desirable when the screen is subjected to excessive physical abuse. nother material that may be useful in the formation of the walled network is polyamide. Polyamide is very tough yet resilient.
[0053] The optical component made from walled networks of filled cells may use a variety of filler materials. Useful transparent polymers may comprise polyester, acrylic, polyurethane, epoxy, cyclic olefinand cellulose esters. In one embodiment the filler is polyester. Polyesters typically have good optical clarity for the transmission of light. In another embodiment the filler may be acrylic. Acrylics are desirable because they can be formulated to flow easily into the walled network. They also have excellent optical clarity and are very hard and scratch resistant when hardened. They also can be formulated to be radiation curable. Since there is some volume associated with the filled networks, the use of radiation curable materials is desirable.. Polyurethane may also be used as a filler. Polyurethane is a very tough polymer and offers good optical clarity. In a preferred embodiment of this invention epoxy may be used as a filler for the walled network. Epoxies have a wide range of viscosities and can be formulate to provide excellent leveling. They can be to provide a broad range of refractive index. They can be cured with thermal or radiant energy and are very useful in that they can be used with walled networks that are bent into a contoured shape. Useful shapes may include planar and non-planar shapes. In one embodiment the shape may be curved. Such a shape may be useful for surround viewing in which the screens provide peripheral viewing in either the vertical and or horizontal planes. In the selection of the walled network it may be desirable to have a screen that is formed into a shape and fully hardened to freeze that shape or a flexible screen that could be bent and then returned to its original shape. Such screens would provide outstanding wear resistance and provide added versatility to the end user. The selection of the walled network and the filler material properties need to be considered when building the screen's end-use properties. When forming an optical component with a filled network, it is desirable to maximize the transparent area while minimizing the wall thickness. In an embodiment of this invention the transparent filled cells and network walls have a thickness ratio of between 30:1 and 3:1. Filled network walls above 30:1 tend to be very thin and weak and are difficult to form while filling. Network walls below 3:1 have limited viewing area and the wall structure is more visible. Useful network wall thickness for this invention may be from 10 to 750 micrometers. Below 10 micrometers it is difficult to vacuum form a network wall and it has very little strength. Above 750 micrometers the walls are very thick and are visible unless the screen is viewed from a very long distance.
[0054] Another aspect of the three-dimension network is the overall depth of the walled network. Useful depths may be between 100 and 8000 micrometers. When waveguiding light for a projection screen it is desirable to have a thickness equal to or greater than 100 micrometers. Below 100 micrometers, ambient light from viewing room sources or from sunlight may pass directly through the waveguide and not be absorbed by the black opaque layer. Additionally walled networks less than 100 micrometers tend to be very weak and flimsy. In optical components when the layer thickness is greater than 8000 micrometers, there are high light losses and therefore the overall operating efficiency is reduced.
[0055] Another useful embodiment of this invention is a network that is apertured. In the formation of the network wall structure, it is desirable to have an open or apertured area. Such an opening can be more readily filled with a transparent filler. Additionally it is desirable to have an apertured to walled network with a percent open area of between 65 and 95 percent on a projected basis. Below 65 percent open area, the network walls are visible and tend to interfere with the viewing of the screen while open areas greater than 95 percent have a weak wall that may tend to collapse when filling.
[0056] When making optical components with a walled network, it may also be desirable to provide a lenslet array on at least one side. Lenslet arrays may be useful in directing or shaping light on the inlet side or the viewing side of the component. On the viewing side the array may be used to improve the gain of a display screen in either or both the vertical or horizontal viewing planes. In one useful embodiment, the lenslet array is integral to the walled network of filled cells. When filling the network cells the lenslet array may be molded into the surface of the filled polymer or it may be embossed into the surface. An additional means is to preform a lenslet array and use a transparent adhesive material to not only fill the cells but to adhesively connect a sheet to the walled network light inlet and or viewing surfaces. In this embodiment the lenslet array may have different functions. The light inlet side may be a light directing or fresnel lens that can change the light direction and allow the light source to be placed in different locations. This is useful in making slim format projection screens in which the light is directed by a lens or mirror into the transparent filled cells from a sharp angle. The lens array provides a means of bringing the light into the transparent waveguide filled cell from a steep angle to a shallow angle. This helps to reduce the refractive difference between the filled cell and the adjacent clad layer of the walled network. On the viewing side it may be desirable to have a lenslet array provide diffusion of the light to improve the viewing gain of the system. In this way the horizontal and vertical-viewing angle may be controlled. In another embodiment the network of filled cells contains diffusion materials on at least one side. The diffusion material may be bulk diffusing or light shaping and furthermore the light shaping material may be holographic. Holographic made shapes may be designed and adjusted to control light in all angles and furthermore may help to reduce glare from ambient room light.
[0057] In another useful embodiment of this invention the lenslet array may be a crossed lenticular pattern. If two lenticular lens arrays are crossed at 90 degrees both vertical and horizontal viewing improvements may be made.
[0058] The lenslet arrays useful in this invention may be made with a transparent radiation curable material. Such materials may include UV monomers. UV-cured materials have excellent optical clarity and can be formed into a variety of shapes and are hardened by exposure to UV light and therefore avoids costly heat drying. UV and EB polymerization of acrylics and other materials are well known in the field of paints and surface coatings. The basic principles for either UV or EB are essentially the same. A material is cured by the irradiation of polymerizable mixtures of double-bonds containing oligomers, monomers, prepolymers, additives such as tackifiers, UV stabilizer, chain transfer agents, viscosity control or photoinitiators. In general there is a decomposition of photo-initiator into free radicals that reacts with molecules of monomer. The reaction continues with additional monomers in a propagation reaction. The reaction is terminated as polymeric molecules are formed by crosslinking. An advantage of EB curable over UV curable is that EB can cure through opaque materials.
[0059] UV curable materials typically are clear and can be applied to a substrate by most conventional coating methods known in the art. This coating contains a photo-initiator and when exposed to a source of UV radiation the polymerization process starts. Typical sources of UV energy include pressure mercury vapor lamps, iron-doped and gallium-doped spectral outputs or excimer UV lamps. The coating weight may be varied to optimize the properties.
[0060] The optical components made from a filled network of cells may have cells of a variety of shapes. A hexagonal shape is useful in that it provides a geometric design that allows for a very efficient packing of cells that helps to minimize any viewing obstructions form the walled network. Other useful shapes may be rectangular or circular in shape.
[0061] The walled network may be formed by a variety of means. One very useful means is to vacuum form the walled network by vacuum extrusion. Either a monolayer or multi walled network may be formed by melting the desired polymer and casting it onto a vacuum roll that contains the desired cell geometry. By applying vacuum to the shaped vacuum roller, the molten resin is formed around the shapes in the roller. When sufficient vacuum is applied an open or apertured cell is formed with a walled network. As the resin solidifies by cooling a polymeric network is formed. Another means of forming a walled network is to weave fiber or filaments into the desired shape and then fill the open areas with a transparent polymer. Instead of weaving it is possible to fuse by heat, ultrasonic and or pressure various strands of materials to form a walled network. A solid polymer sheet may also be formed into an open network of cells by punching or ablating holes through the sheet by mechanical or laser light. In another embodiment of this invention the network may be thermoformed. Thermoformed networks are made using a heat assisted process in which the network wall or cell structure are cast into a sheet and the sheet is them made to comply to a molded shape with the assistance of heat and/or pressure such as a vacuum. This type of process typically is a sheet process while the vacuum extrusion process may be either a continuous web or sheet process.
[0062] A process of forming a component providing a structure comprising network of filled cells comprising walls containing a polymer having a first refractive index and a filler containing a material having a second refractive index wherein said walled network is vacuum formed with at least one black layer and with apertured cells, placing said walled network over a lenslet array mold, filling said apertured cells and lenslet array mold with a transparent hardenable polymer, hardening said transparent hardenable polymer, removing said filled walled network with an integrally attached lenslet array from said lenslet array mold.
[0063] The optical component of this invention comprising a network of filled cells comprising walls containing a polymer having a first refractive index and a filler containing a material having a second refractive index further comprises a waveguide and in particular the optical component is a projection screen display. A process embodiment for forming the component of this invention provides a structure comprising a network of filled cells with walls containing a polymer having a first refractive index and a filler containing a material having a second refractive index wherein said walled network is vacuum formed with at least one black layer and with apertured cells, placing said walled network over a lenslet array mold, filling said apertured cells and lenslet array mold with a transparent hardenable polymer, hardening the transparent hardenable polymer and removing the filled network with integrally attached lenslet array from the mold, positioning the structure in front of a light directing film and projecting light through said light directing film and said filled vacuum formed walled network.
[0064] In a separate embodiment of this invention an optical component comprising a walled network of filled cells containing a polymer having a first coefficient of extinction and the adjacent wall containing a polymer having a second coefficient of extinction and also containing a filler material. By providing a transparent filler material in the open aperture of a wall network that has a coefficient of extinction different and higher than that of the adjacent wall of said wall network, it is possible to form a screen that can be used for privacy. The wall adjacent to the filler has a higher light absorbing capacity than the transparent filler and will therefore limit the viewing side of the screen. When the network cells are aligned with a somewhat linear pattern to the network, the viewability of the screen from the sides opposite to the linear pattern is reduced. Such screens are useful in tight seating situations in which the user desires to restrict others from seeing what is display. One example of this would be for computer screen that is used in public areas such as personal labtop computers. Other uses may be for games in which the intended user needs to restrict others from seeing his move or position.
[0065] The polymer of the second coefficient of extinction may also contain an opaque material that is light absorbing. The opaque material may be any color but in general black has more light absorbing properties. The black material may be a pigment, such as carbon black, or a black dye. Carbon black typically has better light absorbing properties than black dyes. The percent transmission of the polymer having the second coefficient of extinction may be between 0 and 20 percent. A material is fully absorbing at 0 percent transmission while materials greater than 20 percent transmission will not absorb as much light.
[0066] As discussed above the polymers for the walled network may be polyolefin, polyester, polyamide, polycarbonate and copolymers thereof. The thing to remember is that the wall of the walled network that is adjacent to the filler should have a lower coefficient of extinction than the transparent filler. This may be achieved in part by the selection and paring of the filler and the adjacent wall of the network or by the addition of materials to either or both the filler polymer or the polymer used to form the adjacent wall of the walled network. As with display screens discussed above, privacy screens may use a variety of transparent polymers for the filler. Typically it is desirable to have a percent transmission of between 80 and 100 percent to assure that there is good image quality on the viewing side of the screen. Typical polymers may include but are not necessarily limited to polyester, acrylic, polyurethane, and epoxy. When using a walled network those polymers that have a wide range of viscosity and can be flowed into the network's open aperture without air entrapment are the most desirable. Radiation curable polymer such as acrylates and chemically cured materials such as epoxies work the best. Although not disclosed in this discussion, the filler polymer may contain additives to improve the wetting of the walled surface to obtain better adhesion and minimize air entrapment. The surface energy of the wall network may also be adjusted to improve the wetting and adhesion at the interface between the filler polymer and the wall of the network.
[0067] In another embodiment of this invention the optical component used as a privacy screen may further contain a lenslet array to change the viewing angle of the screen. Typically for display screens that are used for rear projection TV or other display applications, it is desirable to provide a broad view angle. For privacy screens it is desirable to limit the viewing angle. This may also be accomplished by the addition of lenslet array shapes that narrow the viewing angle By collimating the light as it exits the privacy screens, it can be narrowed. Such collimating lenslets may be linear, triangular, pyramidal or other shape that provides light collimation.
[0068] Embodiments of the invention provide a process for making a waveguide or privacy screen that reduces the number of manufacturing steps and can be assembled without having to stack and adhere multiple layers together to form a screen.
[0069] The following examples illustrate the practice of this invention. They are not intended to be exhaustive of all possible variations of the invention. Parts and percentages are by weight unless otherwise indicated.
EXAMPLES
Example 1
[0070] The waveguide example was made from a preformed aperture single walled structure obtained from Tredegar Film Products Corporation of Richmond, Va. A small sample of the network film was cut and spray painted black to simulate a black absorbing layer. The sample was air dried and then sprayed with a clear acrylic thin layer to simulate a clear clad layer of a lower refractive index than the filler. The sample was allowed to dry. The multi layered open film was laid flat and then filled with a two-part epoxy and allowed to cure over-night to form a network.
Example 2
[0071] This sample was made in a similar manner except part way through the epoxy drying process the network was bent into a curved shape to simulate a wrap around screen.
Example 3
[0072] This sample was made the same as example one except the open apertured network was placed on top of a lens array. The epoxy was applied to the open aperture to fill the cells and to provide adhesion to the lens array.
Example 4
[0073] This sample is a preformed multi walled apertured network formed by coextruding two layers of polyolefin onto a vacuum roll and applying a vacuum to form a two layer apertured cell. The wall adjacent to the aperture is a clear polymer while the other wall is a carbon filled polyolefin layer. The preformed film sheet is filled with a transparent polymer such as an epoxy.
Example 5
[0074] This sample is the same as example 4 but a UV curable material is used to fill the aperture.
Example 6
[0075] This sample is the same as example 1 except a UV curable material was used to fill the cells.
Example 7
[0076] This waveguide example was made from a performed apertured single walled structure obtained from Tredegar Film Products Corporation of Richmond, Va. A small sample of the network film was cut and spray painted black to simulate a black absorbing layer. The sample was air dried and then sprayed with a diluted paint consisting of 1 part spray paint to 10 parts of solvent to simulate a layer of lower coefficient of extinction than the filler. The sample was allowed to dry. The multi layered open film was laid flat and then filled with a two-part epoxy and allowed to cure over-night to form a network..
[0077] Materials:
[0078] Epoxy:
[0079] The formulations suitably employ 1.00 parts of EPON 815 cross-linked with 0.48 parts of EPICURE 3373. Both materials are products of the Shell Chemical Company. EPON 815 is a bisphenol A/epichlorohydrin based resin and EPICURE 3373 is a cycloaliphatic amine. This mixture produced a clear, colorless, hard coating with good adhesion to walled networks. It also provides a low viscosity (<500 cps) which is important in minimizing entrapped air when filling a three-dimensional structure.
[0080] UV Curable:
[0081] NOA 81, manufactured by Norland Products Inc., was evaluated as a typical UV curable material. It is reported to be a mixture of mercapto esters with unsaturated acrylic, vinyl or allylic monomers, oligomers or prepolymers. Prior to curing it has a viscosity of 300 cps. In the cured state it has a refractive index of 1.56 and a Shore D hardness of 90. Coatings of this material were cured at an energy level of 4.9 J/cm 2 .
[0082] Walled Network
[0083] This was an 82 mil thick three-dimensional apertured polyolefin film obtained from Tredegar Film Products Corporation of Richmond, Va.
[0084] The entire contents of the patents and other publications referred to in this specification are incorporated herein by reference.
Parts List
[0085] [0085] 20 is a top view of a walled network
[0086] [0086] 30 is a single cell of a walled network with multiple walls
[0087] [0087] 32 is the outer wall and is opaque and black
[0088] [0088] 34 is the inner wall that is adjacent to the open aperture
[0089] [0089] 36 is an open aperture of a single cell of a walled network
[0090] [0090] 41 is a filled single cell of a walled network with multiple walls
[0091] [0091] 40 is the outer wall and is opaque and black
[0092] [0092] 42 is the inner wall that is adjacent to the filled apertured
[0093] [0093] 44 is a transparent polymer filler in a single network walled cell
[0094] [0094] 51 is a network wall with lenslets array
[0095] [0095] 52 is the filled cell of the network
[0096] [0096] 54 is a lens array
[0097] [0097] 60 is an opaque clad cap layer and outer wall of the network
[0098] [0098] 61 is a top view of a filled walled network
[0099] [0099] 62 is the inner wall that is adjacent to the filled area of the cell
[0100] [0100] 63 is a single element of the filled wall network consisting of a filled area 64 , inner wall 62 and outer wall 60 .
[0101] [0101] 64 is a transparent filler
[0102] [0102] 70 is a three-dimensional view of a walled network
[0103] [0103] 72 is a three-dimensional wall of a wall network
[0104] [0104] 74 is the three-dimensional open aperture
[0105] [0105] 80 is a cell of a three-dimensional walled network showing relative dimensions
[0106] [0106] 82 is the cell width
[0107] [0107] 84 is the open aperture
[0108] [0108] 86 is the cell depth
[0109] [0109] 88 is the cell length
[0110] [0110] 90 is a cross section of a privacy screen
[0111] [0111] 92 is a clear polymer area of the privacy screen with a coefficient of extinction
[0112] [0112] 94 is the first adjacent layer to the clear layer with a lower coefficient of extinction than the clear layer. It also contains a small amount of black material.
[0113] [0113] 96 is a second layer with a higher level of black material than 94
[0114] [0114] 98 is an adhesive layer
[0115] [0115] 100 is a clear film to add strength to the structure
[0116] [0116] 102 is an anti-glare layer
[0117] [0117] 110 is a stacked waveguide made of several stacked individual units 112
[0118] [0118] 112 is a single waveguide with core 118 , clear clad 116 and clad cap 114
[0119] [0119] 114 is a clad cap that is black and opaque
[0120] [0120] 116 is a clear clad and has a lower refractive index than core 118
[0121] [0121] 118 is a transparent polymer core | This invention relates to an optical light transmitting component including a network of cells containing filler material, the cells being walled on the sides and unwalled on the top and bottom portion of each cell, the walled sides comprising a polymer having a first refractive index, and the cells comprising a filler material having a second refractive index greater than the first refractive index, whereby light may be transmitted through the filler material and the unwalled top and bottom portion of the cells. | 7 |
This application is related to a co-pending application Ser. No. 07/570874 filed Aug. 22, 1990.
BACKGROUND OF THE INVENTION
The present invention relates to a slot machine capable of visually suggesting that a game now being played will result in a hit.
A slot machine has a plurality, e.g., three to five, of reels with a plurality of symbols in a series about each outer periphery thereof. These reels start rotating when a game starts. After the rotation of each reel reaches a constant speed, a stop control can be executed. This stop control for each reel rotating at a constant speed is effected upon actuation of a stop button in the case of a slot machine of the manual stop type, or by the operation of an automatic stop device in the case of a slot machine of the automatic stop type. When all the reels have stopped, the presence or absence of a hit is determined according to the combination of symbols on the respective reels stopping on at least one winning line. The number of winning lines is determined by the number of inserted coins. Coins corresponding in number to the rank of the hit are paid out.
As used herein, the term "coins" includes tokens.
In a conventional slot machine, at a certain time during the period between inserting the coins and starting the reel stop control, a judgment is made by using random numbers whether or not the game is to have a hit; and if a hit is to occur, its rank is also determined. In accordance with this judgment, the reel stop control is effected. In a slot machine of the manual stop type, even a game which otherwise could be a hit may result in a lost game because the reel stop positions are restricted. In this case, the hit is carried over to the next game.
Players naturally want a big hit with many coins paid out or a bonus game having a high hit probability. But such special hits cause many coins to be paid out. In order to maintain a stable payout rate, the probability of occurrence of special hits is controlled by using random numbers as described before, to inhibit concentrated occurrences of special hits. With a limited or low probability of occurrence of special hits, players tend to have the impression that a special hit may suddenly occur after a number of repeated games. Most of the games therefore arouse the player's interest only after the reels stop, with an uninteresting wait during the period from the start of rotation of the reels to their stopping. This is one of the major reasons that known games are monotonous and dull. The same problem is also associated with a slot machine of the type wherein symbols are displayed on a CRT instead of reels.
OBJECT OF THE INVENTION
It is therefore an object of the present invention to provide a slot machine capable of visually suggesting that the game now being played will result in a hit.
SUMMARY OF THE INVENTION
In order to achieve the above and other objects and advantages of this invention, the speed of movement of the series of symbols is determined in accordance with a prior decision as to whether there will be a hit. For a game that can have a hit, the symbol series are moved at a speed different from the speed used for a game that cannot have a hit. A player thereby can be given an indirect suggestion, by the difference between the speeds, as to whether the game can be a hit. This speed difference may be achieved by moving the symbol series at a low speed from the beginning, or by changing the speed during movement of the symbol series. In a slot machine of the manual stop type, the stop operation by an operator can be advantageously carried out with proper timing because the speed of the symbol series is low. Conversely, the speed for a game that can have a hit may be faster than for a game that cannot have a hit.
According to the present invention, whether a game can have a hit is thus foretold while the symbol series are in motion. The monotony of the game is thus relieved, with increased enjoyment by the player. Such a prior suggestion preferably is given during a game that can have a special hit with a large award. However, it is not limited thereto, as such a prior suggestion may also be given during a game which can have only a small hit.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the present invention will become apparent from the following detailed description of the invention when read in connection with the accompanying drawings, in which:
FIG. 1 is a front perspective view showing an embodiment of the slot machine according to the present invention;
FIG. 2 is a schematic diagram showing the electric circuit arrangement of the slot machine shown in FIG. 1;
FIG. 3 is a functional block diagram of the system controller shown in FIG. 2; and
FIGS. 4 to 6 are timing charts showing the relationships between drive pulses and pulse motor revolution rates.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1 showing a perspective view of a slot machine according to the present invention, the slot machine 2 has a front door 2a capable of being opened and closed. The front door 2a has stop buttons 3 to 5, start lever 6 and coin inlet 7 mounted thereon. A front panel 8 is fitted in the front door 2a above the stop buttons 3 to 5. First to third reels 9 to 11 are rotatably mounted at the back of the front panel 8. On the outer periphery of each reel 9 to 11, various symbols such as "lemon", "7", and "bell" are drawn and can be viewed from three windows 12 to 14 formed in the front panel 8. A plurality of winning lines 16 are drawn over the windows 12 to 14 which are made effective in accordance with the number of inserted coins.
Upon actuation of the start lever 6 after coins are inserted into the coin inlet 7, the reels 9 to 11 start rotating simultaneously. After the rotating reels 9 to 11 reach a constant angular velocity, the stop buttons 3 to 5 can be actuated by a player. After the stop buttons 3 to 5 are operated, the stop control begins to operate and the reels 9 to 11 stop, and certain symbols are aligned on an effective winning line, these symbols being determined in accordance with the presence or absence of a predetermined hit and its rank. If a combination of three symbols stopping at the effective winning line is a hit symbol combination, coins corresponding in number to the rank of the hit are paid out into a coin saucer 17. If the stop buttons 3 to 5 are not operated with a predetermined period of time, each reel 9 to 11 is stopped by a known automatic stop mechanism. Reference numeral 18 represents a display unit for displaying the number of coins to be paid out.
Referring to FIG. 2 showing the electric circuits of the slot machine 2, pulse motors 20 to 22 for driving the respective reels 9 to 11 are connected via corresponding drivers 23 to 25 to a system controller 26. Photosensors 27 to 29 detect light interrupting members 30 to 32 mounted on the reels 9 to 11 so that reference positions of the reels 9 to 11 can be detected. Connected to the system controller 26 are stop switches 3a to 5a for outputting stop signals upon actuation of the stop buttons 3 to 5, a start switch 6a to be operated by the start lever 6, a coin insertion sensor 35 for detecting a coin inserted into the coin inlet 7, and a coin payout unit 37 which is driven by a driver 36. The start switch 6a outputs a start signal when the start lever 6 is manipulated. The coin insertion sensor 35 outputs a random number generation signal when a coin is detected by the coin insertion sensor 35.
Referring to FIG. 3 illustrating the function of the system controller 26, a random number generator 40 is started in operation upon insertion of a coin, and generates a random number from "1" to "3000". The random number generator 40 is connected to a sampling circuit 41 which starts sampling upon reception of the start signal. The sampling circuit 41 is preferably constructed such that it does not sample the same random number again in 3000 games. The sampling circuit 41 is connected to a symbol determining circuit 42 which refers to a symbol table 43, using the sampled number as a key thereby to determine a symbol combination of the three symbols thereof. The data of each determined symbol is sent to a stop position determining circuit 44 to which are connected the stop switches 3a to 5a and a motor controller 45 for controlling the pulse motors 20 to 22.
The stop position determining circuit 44 receives the stop signals from the stop switches 3a to 5a and controls the pulse motors 20 to 22 to stop them. In this stop control, by referring to the revolution position signals of the reels 9 to 11 supplied from a search circuit 47 to be described later, the stop position determining circuit 44 controls the motor controller 45 so that the symbols determined by the symbol determining circuit 42 are caused to stop on an effective winning line 16. Note that if the timings of actuating the stop buttons 3 to 5 and of actually stopping the reels 9 to 11 are considerably different, players feel the manner of stopping to be unnatural. For this reason, a shift control (e.g., by the amount corresponding to a plurality of symbols) which seems natural to the players is carried out in order to stop the symbols on a winning line. Consequently, a symbol combination determined by the symbol determining circuit 24 might not necessarily be established. In such a case, the stop control for a hit combination is carried over to the next game.
Connected to the motor control circuit 45 are the start switch 6a, a drive pulse timing table 46, the search circuit 47, and a payout controller 48. The drive pulse timing table 46 stores the timing data for outputting drive pulses from the motor control circuit 45 to the pulse motors 20 to 22. If symbol "7" signals are outputted for all reels from the stop position determining circuit 44 to the motor control circuit 45, the motor control circuit 45 decelerates the pulse motors 20 to 22 rotating at a constant speed after a lapse of a predetermined time. For instant, as shown in FIG. 4, the stop position determining circuit 44 sends drive pulses to the pulse motors 20 to 22 such that the constant revolution rate or speed of N 1 rpm is lowered from time T 4 , and at time T 5 it reaches a constant revolution rate of N 2 rpm. If the symbol combination "777" has been carried over from the previous game, as shown in FIG. 5 the circuit 44 sends drive pulses to the pulse motors 20 to 22 such that the motors are accelerated not to the constant revolution rate of N 1 rpm, but rather to the constant revolution rate of N 2 rpm. If a symbol combination other than the symbol combination "777" is to be established, as shown in FIG. 6 drive pulses are sent to the pulse motors 20 to 22 such that the motors are driven at a constant revolution rate of N 1 rpm. As seen from FIG. 5, the revolution rate of each pulse motor is controlled by changing the period of the drive pulses.
The search circuit 47 checks the positions of symbols on the rotating reels 9 to 11 in accordance with the numbers of drive pulses counted from the time when the photosensors 27 to 29 detect the reference positions. The obtained revolution position signals are sent to the stop position determining circuit 44. When it is found that the symbol combination is a hit, after all the pulse motors 20 to 22 have stopped, the payout controller 48 causes the driver 36 and coin payout unit 37 to pay out coins corresponding in number to the rank of the hit.
Next, the operation of this embodiment will be described with reference to FIGS. 4 to 6. When a coin is inserted into the coin inlet 7 at time T 0 shown in FIG. 4, the coin insertion sensor 35 sends a random number generation signal to the random number generator 40 which then starts operating. When the start lever 6 is manipulated at time T 1 , the start signal is sent to the sampling circuit 41 and motor controller 45. The sampling circuit 41 samples a random number from the random number generator 40 and sends it to the symbol determining circuit 42. If the sample random number falls within the range from "1" to "10", it means the machine will display a hit symbol combination "777" having a large reward. The symbol determining circuit 42 refers to the symbol table 43 to determine the symbols for the reels 9 to 11 as "7", and sends the symbol signals representative of the symbol "7" to the motor controller 45. The motor controller 45 starts the pulse motors 20 to 22 at time T 1 in accordance with the data in the drive pulse timing table 46, and causes them to gradually increase their speed of rotation. After the pulse motors 20 to 22 reach the constant revolution rate N 1 rpm at time T 3 , the stop buttons 3 to 5 can be actuated. Deceleration starts at time T 4 , and at time T 5 the pulse motors are driven in a low constant revolution rate of N 2 rpm. Upon actuation of a stop button during the period from time T 3 to T 8 , the corresponding pulse motor starts being decelerated to thereby make the predetermined symbol stop on the winning line. If the stop buttons are not actuated during this period, the pulse motors 20 to 22 start undergoing the stop control after time T 8 as indicated by the broken line.
For instance, upon actuation of the stop button 3 during the period from time T 3 to T 4 , a stop position signal is outputted from the stop position determining circuit 44 to the motor controller 45. Referring to the revolution position signal from the search circuit 47, the motor controller 45 executes a stop control for the pulse motor 20 to stop the symbol "7" of the first reel 9 on the winning line 16. The remaining two pulse motors 21 and 22 are decelerated from time T 4 , and rotate at a constant revolution rate of N 2 rpm beginning at time T 5 . If the stop button 4 is actuated before or after time T 5 for example, the stop position determining circuit 44 and motor controller 45 execute a stop control for the pulse motor 21 to stop the symbol "7" of the second reel on the winning line 16. If the stop button 5 is actuated at time T 6 , the motor controller 45 starts decelerating the pulse motor 22 rotating at the constant revolution rate of N 2 rpm so as to stop it at time T 7 . After all the reels stop, the symbols on the reels 9 to 11 on the effective winning line 16 are all "7", thereby to establish a special hit symbol combination "777". After all the reels 9 to 11 stop, in accordance with the rank of the displayed hit symbol combination, the payout controller 45 sends a payout signal to the payout unit 37 to pay out a predetermined number of coins. It is obvious that the order of actuating the three stop buttons is arbitrary.
With a slot machine of the manual stop type, even if a hit of "777" is possible, this "777" might not be established in some cases by using only the reel stop position shift control, depending on the timing of actuating the stop buttons 3 to 5 and the time T 8 which is the onset of automatic stopping. In such a case, the hit is carried over to the next game, wherein the pulse motors 20 to 22 are driven at a low constant revolution rate of N 2 rpm as shown in FIG. 5. Specifically, the motor controller 45 sends drive pulses as shown in FIG. 5 from time T 1 to the pulse motors 20 to 22 to rotate them. At time T 2 the pulse motors 20 to 22 reach the low revolution rate of N 2 rpm, and thereafter the stop buttons can be actuated. Upon actuation of the stop buttons, the motor controller 45 outputs stop position signals to stop the pulse motors 20 to 22 with the symbols "7" on the reels 9 to 11 on the effective winning line 16. In this case also, the same procedure is repeated if the symbol combination "777" is not actually realized. If the presence or absence of a hit is determined prior to the rotation of the reels, the constant revolution rate of N 2 rpm shown in FIG. 5 may be used for the game during which a hit can occur, instead of changing the reel speed in two steps as shown in FIG. 4.
If the random number sampled at time T 1 falls within the range from "11" to "3000", the symbol determining circuit 42 refers to the symbol table 43 to determine a symbol combination. The symbol determining circuit 42 supplies the stop position determining circuit 44 with the symbol signals corresponding to the determined symbol combination. The motor controller 45 supplied with the symbol signals from the stop position determining circuit 44 sends drive pulses as shown in FIG. 6 to the pulse motors 20 to 22 to drive them at the high revolution rate of N 1 rpm. During time T 3 to T 7 , the stop buttons 3 to 5 can be actuated. For instance, if the stop button is actuated at time T 6 , the corresponding pulse motor is controlled to stop the predetermined symbol on the winning line. If the stop buttons are not actuated, the pulse motors are automatically decelerated from time T 7 and stop at time T 9 as indicated by the broken line.
In the above-described embodiment, for a game that can have a special hit with a large award, the pulse motors are driven at a low revolution rate after the lapse of a predetermined time. Instead, after the stop button is first actuated, the remaining two reels may be switched to the low revolution rate. With such an arrangement, games can proceed in an unexpected and hence more interesting manner. Furthermore, in the above embodiment, the reels 9 to 11 are driven at the low revolution rate so that stop buttons can be advantageously actuated at suitable times so as to obtain the symbol "7". However, the reels may be rotated at the high revolution rate for the game that can have a hit, without giving such an advantage. Furthermore, for a hit other than "777" with a smaller award, the speed of rotation of the reels may be changed.
The present invention is applicable to slot machines not only of the manually stopped type but also of the automatically stopped type lacking stop buttons. Furthermore, in the above embodiment, although a series of symbols is carried on the outer periphery of a reel, it will be understood that this invention is equally applicable to a video-type slot machine with symbol series displayed on a display unit. Coins may be paid out each time a hit is made, or the number of coins obtained may be added to a credit counter to display the cumulative result each time a hit occurs. In the latter case, without inserting a coin, the game can be started upon manipulation of the start lever 6 and the contents of the credit counter reduced correspondingly. A coin number designation button may preferably be provided so as to designate the number of coins to be considered to have been inserted.
Although the invention has been described in detail above with reference to a preferred embodiment, it is to be understood that various changes and modifications within the scope and spirit of the invention will be apparent to people of ordinary skill in this technological field. Thus, the invention should be considered as being limited only by the scope of the appended claims. | Whether or not a game of a slot machine can result in a hit is determined before the symbol series stop moving, and preferably when a start lever is manipulated for starting the motion of the symbol series. For a game that can be a hit, the speed of movement of the symbol series is switched from a high speed to a low speed, or the speed is set at a low speed from the outset. For a game that cannot be a hit, the symbol series move at a high speed from the outset. From the difference between the speeds of movement, a player can know whether the game can be a hit even while the game is still in progress. | 6 |
FIELD OF THE INVENTION
The present invention relates to sulfone compounds that are useful intermediate compounds for the production of pharmaceuticals, feed additives or food additives such as retinol, and production methods for producing the same, and a process for the production of retinol using the same.
BACKGROUND OF THE INVENTION
There has been disclosed a process for producing retinol by reacting a sulfone of formula (6) shown below with a C10 aldehyde compound derived from linalool by a plurality of steps to obtain a C20 hydroxy sulfone compound, and derivatizing the same by a plurality of steps (U.S. Pat. No. 4,825,006). However, there is a demand for the development of a further improved industrial production process for producing retinol.
SUMMARY OF THE INVENTION
According to the present invention, retinol can be readily obtained by using novel sulfone compounds and a readily available C5 allyl halide compound.
The present invention provides
1. a disulfone compound of formula (1):
wherein Ar denotes a substituted or unsubstituted aryl group, R 1 denotes a hydrogen atom or a protective group of a hydroxyl group and the wavy line means that the disulfone compound is an E or Z geometrical isomer or a mixture thereof;
2. a process for producing the disulfone compound of formula (1) as defined above, which comprises reacting an allylsulfone of formula (2):
wherein Ar and the wavy line have the same meanings as defined in connection with formula (1) above, with an allyl halide compound of formula (3):
wherein X denotes a halogen atom, R denotes a protective group of a hydroxyl group and the wavy line has the same meanings as defined above, in the presence of a base selected from an alkyl lithium, an alkali metal alkoxide, an alkali metal amide, an alkali metal hydride, or an alkali metal hydroxide, and optionally deprotecting;
3. a process for producing retinol, which comprises reacting the disulfone compound of formula (1):
wherein Ar, R 1 and the wavy line have the same meaning as defined above, with a base selected from an alkali metal alkoxide, an alkali metal amide, an alkali metal hydride, or an alkali metal hydroxide, and optionally deprotecting;
4. an allylsulfone compound of formula (2):
wherein Ar and the wavy line have the same meanings as defined above;
5. a process for producing an allylsulfone compound of formula (2) as defined above, which comprises reacting the sulfone compound of formula (4):
wherein R, Ar and the wavy line have the same meanings as defined above, with an arylsulfinate of formula (5):
ArSO 2 M (5)
wherein Ar has the same meaning as defined above in connection with formula (1), and M denotes an alkali metal, in the presence of a palladium catalyst; and
6. a process for producing a sulfone of formula (4) as defined above, which comprises reacting a sulfone of formula (6):
wherein Ar has the same meaning as defined above, with an allyl halide compound of formula (3):
wherein X, R and the wavy line have the same meanings as defined above, in the presence of a base selected from an alkyl lithium, an alkali metal alkoxide, an alkali metal amide, or an alkali metal hydride.
DETAILED DESCRIPTION
A description will be made to the substituent groups in formulae (1) through (6).
Examples of the protective group represented by R1 or R in the present specification include, for example, an acyl group, a silyl group, tetrahydropyranyl group, an alkoxymethyl group (e.g. a methoxymethyl group, a methoxyethoxymethyl group and the like), 1-ethoxyethyl group, a p-methoxybenzyl group, a t-butyl group, a trityl group, and an alkoxy carbonyl group such as 2,2,2-trichloroethoxycarbonyl group, allyloxycarbonyl or the like.
Examples of the acyl group include, for example,
a C 1 -C 6 alkanoyl group, which may be substituted with a halogen atom or an alkoxy group, and
a benzoyl group, which may be substituted with a halogen atom, a hydroxy group, an alkoxy group, an acetoxy group, a nitro group or the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Specific examples of the C 1 -C 6 alkanoyl group, which may be substituted with a halogen atom or an alkoxy group include, for example, a formyl, acetyl, ethoxyacetyl, fluoroacetyl, difluoroacetyl, trifluoroacetyl, chloroacetyl, dichloroacetyl, trichloroacetyl, bromoacetyl, dibromoacetyl, tribromoacetyl, propionyl, 2-chloropropionyl, 3-chloropropionyl, butyryl, 2-chlorobutyryl, 3-chlorobutyryl, 4-chlorobutyryl, 2-methylbutyryl, 2-ethylbutyryl, valeryl, 2-methylvaleryl, 4-methylvaleryl, hexanoyl, isobutyryl, isovaleryl, pivaloyl, or the like.
Examples of the benzoyl group, which may be substituted with a halogen atom, a hydroxy group, an alkoxy group, an acetoxy group, a nitro group or the like include, for example, a benzoyl, an o-chlorobenzoyl, m-chlorobenzoyl, p-chlorobenzoyl, o-hydroxybenzoyl, m-hydroxybenzoyl, p-hydroxybenzoyl, o-acetoxybenzoyl, o-methoxybenzoyl, m-methoxybenzoyl, p-methoxybenzoyl and p-nitrobenzoyl group.
Examples of the silyl group include, for example, a trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl group and the like.
Preferred protective group is an acyl group (e.g. acetyl group and the like).
Examples of the unsubstituted or substituted aryl group represented by “Ar” include, for example, a phenyl group and a naphthyl group, and a phenyl or naphthyl group substituted with a straight or branched C1-C5 alkyl group, a straight or branched C1-C5 alkoxy group, a halogen atom, a nitro group or the like.
Examples of the C1-C5 alkyl group include, for example, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a sec-butyl group, a t-butyl group, an isobutyl group, a n-pentyl group, a t-amyl group, and the like.
Examples of the C1-C5 alkoxy group include, for example, a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a sec-butoxy group, a t-butoxy group, an isobutoxy group, a n-pentoxy group, a t-amyloxy group and the like.
Specific examples of the unsubstituted or substituted aryl group include, for example, phenyl, naphthyl, o-tolyl, m-tolyl, p-tolyl, o-methoxyphenyl, m-methoxyphenyl, p-methoxyphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, o-bromophenyl, m-bromophenyl, p bromophenyl, o-iodophenyl, m-iodophenyl, p-iodophenyl, o-fluorophenyl, m-fluorophenyl, p-fluorophenyl, o-nitrophenyl, m-nitrophenyl and p-nitrophenyl and the like. Preferred are a phenyl group, a tolyl group and the like.
The disulfone compound of formula (1) can be obtained, for example, by a process of reacting the allylsulfone compound of formula (2) with an allyl halide compound of formula (3) in the presence of a base selected from an alkyl lithium, an alkali metal alkoxide, alkali metal amide, alkali metal hydride or an alkali metal hydroxide.
Examples of the halogen atom represented by X in formula (3) typically include a chlorine atom, a bromine atom, and an iodine atom.
Specific examples of the allyl halide compound of formula (3) include, for example, an ally halide compound of formula (3), wherein X is a bromine atom, and R is an acetyl group.
Examples of the alkyl lithium include, for example, n-butyl lithium, sec-butyl lithium, t-butyl lithium and the like.
Examples of the alkali metal alkoxide include, for example, a C1-C5 alcoholate of an alkali metal such as sodium methoxide, potassium methoxide, lithium methoxide, sodium ethoxide, potassium ethoxide, lithium ethoxide, potassium t-butoxide, sodium t-butoxide, lithium t-butoxide, sodium t-amylate, potassium t-amylate and the like.
Examples of the alkali metal amide include, for example, lithium amide, potassium amide, sodium amide, lithium diisopropylamide, sodium hexamethyldisilazide, potassium hexamethyldisilazide, lithium hexamethyldisilazide and the like.
Examples of the alkali metal hydride include, for example, sodium hydride, potassium hydride, lithium hydride and the like.
Examples of the alkali metal hydroxide include, for example, sodium hydroxide, potassium hydroxide and lithium hydroxide.
Any bases selected from the alkyl lithium, alkali metal alkoxide, alkali metal amide, alkali metal hydride and alkali metal hydroxide may be used together. For example, sodium t-butoxide and sodium hydride may be used together. Furthermore, sodium t-butoxide may be produced, in situ, in the reaction mixture, from a combination of sodium hydride and t-butanol, and lithium diisopropyl amide can be produced from a combination of diisopropylamine and n-butyl lithium.
The amount of the base that may be used in the reaction is usually 0.5 to 3 moles per mol of the allylsulfone compound of formula (2).
The reaction is usually conducted in an organic solvent. Examples of the organic solvent that may be used include, for example,
an aprotic polar solvent such as acetonitrile, N,N-dimethylformamide, hexamethylphosphoric triamide, sulfolane, 1,3-dimethyl-2-imidazolidinone, 1-methyl-2-pyrrolidinone, or the like,
an ether solvent such as diethyl ether, tetrahydrofuran,
1,4-dioxane, dimethoxyethane, anisole, or the like,
a hydrocarbon (aliphatic or aromatic) solvent such as n-hexane, cyclohexane, n-pentane, benzene, toluene and xylene. The solvent may be employed alone or as a mixture thereof.
The reaction temperature may be set within a range of from −78° C. to the boiling point of the solvent used.
Any suitable phase-transfer catalyst can be used to promote the reaction, if necessary.
Examples of the phase-transfer catalyst include, for example, quaternary ammonium salts, quaternary phosphonium salts, sulfonium salts and the like are mentioned. Preferred are quaternary ammonium salts.
Examples of quaternary ammonium salts include tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, tetrapentylammonium chloride, tetrahexylammonium chloride, tetraheptylammonium chloride, tetraoctylammonium chloride, tetrahexadecylammonium chloride, tetraoctadecylammonium chloride, benzyltrimethylammoniumn chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, 1-methylpyridinium chloride, 1-hexadecylpyridinium chloride, 1,4-dimethylpyridiniium chloride, tetramethyl-2-butylammonium chloride, trimethylcyclopropylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrapentylammonium bromide, tetrahexylammonium bromide, tetraheptylammonium bromide, tetraoctylammonium bromide, tetrahexadecylammonium bromide, tetraoctadecylammonium bromide, benzyltrimethylammonium bromide, benzyltriethylammonium bromide, benzyltributylammonium bromide, 1-methylpyridinium bromide, 1-hexadecylpyridinium bromide, 1,4-dimethylpyridinium bromide, tetramethyl-2-butylammonium bromide, trimethylcyclopropylammonium bromide, tetramethylammonium iodide, tetrabutylammonium iodide, tetraoctylammonium iodide, t-butylethyldimethylammonium iodide, tetradecyltrimethylamsmonium iodide, hexadecyltrimethylammonium iodide, octadecyltrimethylammonium iodide, benzyltrimethylammonium iodide, benzyltriethylammonium iodide and benzyltributylammonium iodide and the like.
Examples of quaternary phosphonium salts include tributylmethylphosphonium chloride, triethylmethylphosphonium chloride, methyltriphenoxyphosphonium chloride, butyltriphenylphosphonium chloride, tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride, hexadecyltrimethylphosphonium chloride, hexadecyltributylphosphonium chloride, hexadecyldimethylethylphosphonium chloride, tetraphenylphosphonium chloride, tributylmethylphosphonium bromide, triethylmethylphosphonium bromide, methyltriphenoxyphosphonium bromide, butyltriphenylphosphonium bromide, tetrabutylphosphonium bromide, benzyltriphenylphosphonium bromide, hexadecyltrimethylphosphonium bromide, hexadecyltributylphosphonium bromide, hexadecyldimethylethylphosphonium bromide, tetraphenylphosphonium bromide, tributylmethylphosphonium iodide, triethylmethylphosphonium iodide, methyltriphenoxyphosphonium iodide, butyltriphenylphosphonium iodide, tetrabutylphosphonium iodide, benzyltriphenylphosphonium iodide, hexadecyltrimethylphosphonium iodide and the like.
Examples of sulfonium salts include dibutylmethylsulfonium chloride, trimethylsulfonium chloride, triethylsulfonium chloride, dibutylmethylsulfonium bromide, trimethylsulfonium bromide, triethylsulfonium bromide, dibutylmethylsulfonium iodide, trimethylsulfonium iodide and triethylsulfonium iodide and the like.
The amount of such a phase transfer catalyst that may be used is usually about 0.01 to about 0.2 moles, preferably about 0.02 to about 0.1 mol per mol of the allylsulfone compound (2).
The reaction is preferably conducted in the absence of oxygen, for example, in an inert gas atmosphere of nitrogen gas or argon gas. The solvent that may be used is preferably degassed prior to use. An antioxidant such as 3,5-di-t-butyl-4-hydroxytoluene (BHT), 2-&3-t-butyl-4-hydroxyanisole(BHA), vitamin E, ethoxyquin or the like may be preferably added in the reaction.
After completion of the reaction, the disulfone compound of formula (1) can be isolated by a usual post-treatment such as extraction, crystallization, various kinds of chromatography and/or the like. The disulfone compound of formula (1) wherein R 1 is a hydrogen atom may be produced by the reaction of alkali hydroxide, while a protective group R such as the acyl group being removed during the reaction. Alternatively, the protective group may be optionally deprotected by those suitable procedures as described below for the production of retinol, if desired,
The disulfone compound of formula (1) can be converted to retinol by a process, which comprises reacting the disulfone compound of formula (1) with a base selected from an alkali metal alkoxide, an alkali metal amide, an alkali metal hydride, or an alkali metal hydroxide, and optionally deprotecting.
The same alkali metal alkoxide, alkali metal amide, alkali metal hydride, and alkali metal hydroxide as described above for the production process of the disulfone compound of formula (1) can be used in this reaction.
An amount of the base that may be used is usually 2 to 40 moles, preferably 5 to 30 moles per mol of the disulfone compound of formula (1). Preferably employed is the alkali metal hydroxide. Fine power alkali metal hydroxide is preferably used.
Alternatively, the reaction of the disulfone compound of formula (1) with a base is preferably conducted in the presence of a lower alcohol or the phase-transfer catalyst as described above.
Preferred phase-transfer catalyst is the quaternary ammonium salt, and suitable amount of the phase-transfer catalyst is 0.01 to 0.2 mol per mol of the disulfone compound of formula (1).
Examples of the lower alcohol include, for example, methanol, ethanol, isopropanol, n-propanol, n-butyl alcohol, s-butyl alcohol, t-butyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, and the like.
An amount of the lower alcohol that may be used is usually 0.1 to 3 moles per mol of the disulfone compound of formula (1).
In the aforementioned reaction, the organic solvent that may be used in the process for producing the disulfone compound of formula (1) may be employed. Preferred is the hydrocarbon solvent as described above.
The reaction temperature is usually in the range from −30° C. to the boiling point of the solvent used, and preferred is the range from about 0 to about 50° C.
The reaction is preferably conducted in the absence of oxygen, for example, in an inert gas atmosphere of nitrogen gas or argon, and shielding from the light. The solvent that may be used is preferably degassed prior to use. An antioxidant such as 3,5-di-t-butyl-4-hydroxytoluene (BHT), 2-&3-t-butyl-4-hydroxyanisole(BHA), vitamin E, ethoxyquin or the like is preferably added in the reaction.
After completion of the reaction, retinol can be isolated by performing a usual post-treatment, or optional deprotection of the retinol having a protected hydroxy group.
For example, retinol can be obtained by the reaction of the disulfone of formula (1) having an acyl group as R 1 , with a base such as alkali metal hydroxide, alkali metal hydride or the like.
Alternatively, retinol can be obtained, for example, by a suitable deprotecting procedure to remove the protective group R from the obtained retinol having a protected hydroxy group, which procedure includes an acid or base treatment, a treatment with tetraalkylammonium fluoride to remove a sily group, or similar methods as disclosed in Protective Groups in Organic Synthesis, Greene, T. W. 3 rd Edition, Wiley, the whole disclosure of which is incorporated herein by reference.
Retinol is tropically purified in a protected form, by crystallization, various kinds of chromatography and/or the like, if necessary. Protected retinol may be produced by introducing any suitable protective group such as an acetyl group or the like in a conventional manner (e.g. JP4-3391B, or the reference as described above).
Next a description will be made to a process for producing the allylsulfone compound of formula (2), which can be used for producing the disulfone compound of formula (1). The production process for producing the allylsulfone compound of formula (2) comprises reacting the sulfone compound of formula (4) with the arylsulfinate of formula (5) in the presence of a palladium catalyst.
In the arylsulfinate of formula (5), examples of the alkali metal represented by M include, for example, lithium, sodium or potassium.
The substituted or unsubstituted aryl group represented by Ar in formula (5) is described above.
Examples of the arylsulfinate include, for example, lithium, sodium, or potassium arylsulfinate, Specific examples thereof include, for example, sodium benzensulfinate, sodium 1-naphthalensulfinate, sodium 2-naphthalenesulfinate, sodium o-, m- or p-toluenesulfinate, sodium o-, m-, or p-metoxybenzenesulfinate, sodium o-, m-, or p-chlorobenzenesulfinate, sodium o, m-, or p-bromobenzenesulfinate, sodium o-, m-, or p-iodobenzenesulfinate, sodium o-, m, or p-fluorobenzenesulfinate, sodium o-, m-, or p-nitrobenzenesulfinate, and sulfinate salts having lithium or potassium in place of the sodium in the sodium sulfinates described above.
Preferred are sodium benzensulfinate, potassium benzenesulfinate, sodium p-toluenesulfinate, potassium p-toluenesulfinate and the like. The arylsulfinate salt that contains crystal water may be used in the reaction.
The amount of arylsulfinate of formula (5) is usually about 1 to about 3 moles per mol of the sulfone (4).
Examples of the palladium catalyst include, for example, tetrakis (triphenylphosphine) palladium, allyl chloride palladium dimer, palladium acetate, palladium oxide, palladium chloride, palladium hydroxide, palladium propionate, dichlorobis(triphenylphosphine) palladium, di -μ-chlorobis(η-allyl) palladium, dichloro(η-1,5-cyclooctadiene) palladium, dichloro(η-2,5-norbornadiene) palladium, dichlorobis(acetonitrile) palladium, dichlorobis(benzonitrile) palladium, dichlorobis(N,N-dimethylformamide) palladium, bis(acetylacetonato) palladium, palladium charcoal and the like.
The amount of the palladium catalyst is usually 0.001 mol % to 20 mol % per mol of the sulfone compound of formula (4).
A suitable ligand can be used in the reaction. Examples of the ligand include, for example, a phosphrous ligand such as a phosphine ligand, a phosphite ligand or the like.
Examples of the phosphine ligand include, for example, triarylphosphines, trialkylphosphines and tris(dialkylamino)phosphines, which may have a substituent, and the like. Examples of the phosphite ligand include, for example, trialkylphosphite, triarylphosphite and the like.
Specific examples thereof include, for example, triphenylphosphine, tri-t-butylphosphine, tricyclohexylphosphine, dicyclohexylphenylphosphine, dicyclohexyl-o-tolylphosphine, dicyclohexyl-m-tolylphosphine, dicyclohexyl-p-tolylphosphine, dicyclohexyl-o-anisylphosphine, dicyclohexyl-o-biphenylphosphine, diadamantyl-n-butylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine and tris(dimethylamino)phosphine, triphenylphosphite, tri-p-tolylphosphite, tri-m-tolylphosphite, tri-o-tolylphosphite, trimethylphosphite, triethylphosphite, triisopropylphosphite, tri-t-butylphosphite, tris(tridecyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite and the like. The phosphorous ligand may be added separately to the palladium catalyst that does not contain the phosphorous ligand.
The amount the phosphrous ligand that may be used is usually in the range from 1 mol % to 20 mol % per mol of palladium metal.
In this process a base compound or an acid compound is preferably used as an auxiliary agent to promote the reaction more smoothly, thereby the amount of the expensive palladium can be reduced.
Examples of the amine include, for example, a mono-, di-, or tri-(C2-C6)alkyl amine, a secondary or tertiary cyclic amine, a primary, secondary or tertiary aryl amine.
Specific examples thereof include, for example, ethylamine, n-propylamine, isopropylamine, n-butylamine, sec-butylamine, t-butylamine, n-pentylamine, n-hexylamine, cyclohexylamine, aniline, o-, m-, or p-anisidine, 4-n-butylaniline, diethylamine, diisopropylamine, di-n-butylamine, di-n-hexylarnine, pyrrolidine, piperidine, morpholine, N-methylaniline, N-ethylaniline, N-n-butylaniline, N-methyl-p-anisidine, diphenylamine, triethylamine, tri-n-propylamine, triisopropylamine, N,N-diisopropylethylamine, tri-n-butylamine, triisobutylamine, tri-n-pentylamine, tri-n-hexylamine, N-methylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-methylmorpholine, triphenylamine, and ethylenediamine,N,N,N′,N′-tetramethylethylene diamine.
Examples of the acid compound include, a carboxylic acid (e.g. C1-C3 carboxylic acid such as formic acid, acetic acid, propionic acid, oxalic acid, or the like), halo- or nitro-substituted benzoic acid such as p-nitrobenzoic acid, p-chlorobenzoic acid or the like.
In the above reaction, an organic solvent is usually used. Examples of a solvent to be used include, for example, an ether solvent such as diethyl ether, tetrahydrofuran, 1,4-dioxane, dimethoxyethane, anisole or the like, an alcohol solvent such as methanol, ethanol, 2-propanol, t-butanol or the like, an aprotic polar solvent such as acetonitrile, N,N-dimethylformamide, hexamethylphosphoric triamide, sulfolane, 1,3-dimethyl-2-imidazolidinone, 1-methyl-2-pyrrolidinone or the like, and a hydrocarbon (aliphatic or aromatic) solvent such as n-hexane, cyclohexane, n-pentane, benzene, toluene, xylene or the like. These may be employed alone or as a mixture thereof.
The reaction temperature may be optionally selected in the range from −78° C. to the boiling point of the solvent used, and preferred is the range from about 20 to about 100° C. The allylsulfone derivative (2) can be produced by performing, after the reaction, usual post-treatment, such as washing with water, extraction, crystallization and various kinds of chromatography.
The sulfone compound of formula (4) can be produced by a process, which comprises reacting the sulfone compound of formula (6) with the allyl halide compound of formula (3) in the presence of a base selected from an alkyl lithium, an alkali metal alkoxide, an alkali metal amide, or an alkali metal hydride.
The alkyl lithium, alkali metal alkoxide, alkali metal amide, or alkali metal hydride as described for the processes above can be used in this reaction. Preferred bases are the alkyl lithium (e.g. n-butyl lithium, s-butyl lithium, t-butyl lithium, and the like), the alkali metal alkoxide (e.g. sodium methoxide, potassium methoxide, potassium t-butoxide, sodium t-butoxide and the like).
The alkali metal hydride is preferably used together with an auxiliary agent, which include, for example, an alcohol such as n-butyl aclcohol, s-butyl alcohol, t-butyl alcohol, t-amyl alcohol or the like, an amine such as aniline, diisopropylamine or the like, a sulfone such as dimethylsulfone or the like, a sulfoxide such as dimethylsulfoxide or the like, and a mixture thereof The amount of the auxiliary agent is usually 0.1 to 3 moles per mol the sulfone (6). The auxiliary agent can be used as a solvent.
Furthermore, an anion activating agent such as a crown ether, tetramethylethylenediamine or the like may be added in the reaction, or an allyl halide activating agent such as sodium iodide, tetrabutylammonium iodide, or the like may be added.
The amount of the base that may be used is usually about 0.5 to about 3 moles per mol of the sulfone (6).
In the aforementioned reaction, an organic solvent is usually used. The solvent as described above for the production process of the disulfone compound of formula (1) can be employed in this reaction.
The reaction is preferably conducted in the absence of oxygen, for example, in an inert gas atmosphere of nitrogen gas or argon. The solvent that may be used is preferably degassed prior to use. An antioxidant such as 3,5-di-t-butyl-4-hydroxytoluene (BHT), 2-&3-t-butyl-4-hydroxyanisole(BHA), vitamin E, ethoxyquin or the like may be preferably added in the reaction.
After completion of the reaction, the sulfone compound of formula (4) can be isolated by a usual post-treatment such as extraction, crystallization, chromatographies or the like.
The sulfone of formula (6) can be readily produced according to the description of Chem. Lett. 479 (1975), and the allyl halide compound of formula (3) can be readily produced by a method described in U.S. Pat. No. 4,175,204.
EXAMPLES
The present invention will be explained by way of examples, but are not to be construed to limit the invention thereto.
Example 1
A solution of 224 mg (2 mmol) of potassium t-butoxide in 6 ml of N,N-dimethylformamide (DMF) was cooled to −60° C., and then a solution of 585 mg (2 mmol) of sulfone (I) in DMF (4 ml) was added dropwise over 20 seconds. Subsequently, a solution of 215 mg (1 mmol, purity 96%) of allyl halide (II) in DMF (4 ml) was added dropwise at the same temperature over 5 minutes and was stirred at the same temperature for 3 hours. After the reaction, the reaction solution was poured into a saturated aqueous ammonium chloride solution and was extracted with ethyl acetate. The organic layer obtained was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution sequentially, and was dried with anhydrous magnesium sulfate. Thereafter, the solvent was removed by distillation to give a crude yellow oil product. High performance liquid chromatography analysis showed that sulfone compound(III) and (IV) were obtained in a yield of 71.2% and 15.4% respectively.
Sulfone (III)
1 H-NMR δ (CDCl 3 ); 0.73(3H, s), 0.99(3H, s), 1.25-1.64(7H, m), 1.97-2.04(8H, m), 2.37(3H, m), 2.54-2.96(3H, m), 3.74-3.87(1H, m), 4.37(2H, d, J=7 Hz), 5.29(1H, t, J=7 Hz), 7.23(2H, d, J=8 Hz), 7.69(2H, d, J=8 Hz)
Sulfone (IV)
1 H-NMR δ (CDCl 3 ); 0.82(3H, s), 1.04(3H, s), 1.22-1.57(4H, m), 1.30(3H, s), 2.00(3H, s), 2.03-2.24(2H, m), 2.33(1H, br. S), 2.42(3H, m), 2.59(1H, dd, J=7 Hz, 14 Hz), 2.99(1H, dd, J=7 Hz, 14 Hz), 3.91(1H, t, J=7 Hz), 3.99(2H, d, J=7 Hz), 5.40(1H, t, J=7 Hz), 7.31(2H, d, J=8 Hz), 7.75(2H, d, J=8 Hz)
Example 2
A solution of 224 mg (2 mmol) of potassium t-butoxide in 6 ml of DMF was cooled to −20° C., and then a solution of 585 mg (2 mmol) of sulfone (I) in DMF (4 ml) was added dropwise over 20 seconds, then maintained for 5 minutes and thereafter cooled to −60° C. Subsequently, a solution of 215 mg (1 mmol, purity 96%) of allyl halide (II) in DMF (3 ml) was added dropwise thereto at the same temperature over 5 minutes and was stirred for 3 hours. After the reaction, the resultant was poured into a saturated aqueous ammonium chloride solution and was extracted with ethyl acetate. The organic layer obtained was washed with a saturated aqueous sodium hydrogencarbonate solution and a saturated aqueous sodium chloride solution sequentially, and was dried with anhydrous magnesium sulfate. Thereafter, the solvent was removed by distillation to give a crude yellow oil product.
The amount of the crude product was measured by HPLC to show that the yield of sulfone compound (III) was 99.5%.
Example 3
A solution of 116 mg (1.2 mmol) of sodium t-butoxide in 6 ml of DMF was cooled to 0° C., and then a solution of 876 mg (3 mmol) of sulfone (I) in DMF (4 ml) was added dropwise thereto over 20 seconds, and the resulting mixture was maintained at the same temperature for 5 minutes and cooled to −20° C. Then a solution of 215 mg (1 mmol, 96%) of allyl halide (II) in DMF (3 ml) was dropwise added thereto at the same temperature over 5 minutes and stirred for 3 hours. After the reaction, the resultant was poured into a saturated aqueous ammonium chloride solution and was extracted with ethyl acetate. The organic layer obtained was washed with a saturated aqueous sodium hydrogencarbonate solution and a saturated sodium chloride brine sequentially, and was dried with anhydrous magnesium sulfate. Thereafter, the solvent was removed by distillation, resulting in a crude yellow oil product. HPLC analysis showed that the yield of the sulfone (III) was 65.9%.
Example 4
To a solution of 585 mg of sulfone (I) in 6 ml of tetrahydrofuran was cooled to −60° C. was added dropwise 1.16 ml (1.2 mmol) of a tetrahydrofuran solution of sodium hexamethyldisilazide in a concentration of 0.96 mol/liter over 20 seconds and kept at the same temperature for 30 min. Then, a solution of 215 mg (1 mmol, purity 96%) of allyl halide (II) in tetrahydrofuran (3 ml) was dropwise added thereto over 5 min at the same temperature and stirred for 3 hours. After the reaction, the reaction solution was poured into an aqueous saturated sodium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in order and dried over anhydrous magnesium sulfate. Filtrate was evaporated to give a yellow oil product. HPLC analysis of the product showed the yield of the sulfone compound (III) was 70.0%.
Example 5
HPLC analysis of the obtained yellow oil product in this experiment showed that the yield of sulfone derivartive (III) was 59.4% by conducting the experiment in a similar manner as in Example 4 with the exception that 1.0 mol/liter THF solution of lithium diisopropyl amide was used in place of 0.96 mol/liter THF solution of the sodium hexamethyldisilazide.
Example 6
80 mg (2 mmol) of sodium hydride (60% oil suspension) was added to DMF(5 ml) and 88.9 mg (1.2 mmol) of sodium t-butoxide was added thereto and stirred at 50° C. for 2 hours. After a solution of 585 mg (2 mmol) of sulfone (I), and 4 mg (0.02 mmol) of 3,5-d-t-butyl-4-hydroxytoluene (BHT) in 3 ml of DMF was added thereto at the same temperature and stirred for 3 minutes and then cooled to −20° C., and a solution of 215 mg (1 mmol, purity 96%) of allyl halide (II) in DMF(2 ml) was added thereto in 1 minute and kept at the same temperature for 2 hours. After the reaction, the reaction solution was poured into an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order, dried over anhydrous magnesium sulfate, and then filtrate was evaporated to give a crude yellow oil product. The obtained crude product was analyzed by HPLC to show that the yield of sulfone compound (III) was 59.5%.
Example 7
40 mg (1 mmol) of sodium hydride (60% oil suspension) was added to DMF(5 ml) and 99.1 mg (1 mmol) of sodium t-butoxide was added thereto and stirred at 40° C. After a solution of 585 mg (2 mmol) of sulfone (I), and 4 mg (0.02 mmol) of 3,5-d-t-butyl-4-hydroxytoluene (BHT) in 3 ml of DMF was added thereto at the same temperature and stirred for 20 minutes, and then cooled to −20° C. and stirred for 30 minutes, and a solution of 215 mg (1 mmol, purity 96%) of allyl halide (II) in DMF(2 ml) was added thereto in 1 minute and kept at the same temperature for 2 hours. After the reaction, the reaction solution was poured into an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order, dried over anhydrous magnesium sulfate, and then filtrate was evaporated to give a crude yellow oil product. The obtained crude product was analyzed by HPLC to show that the yield of sulfone compound (III) was 59.6%.
Example 8
48 mg (1.2 mmol) of sodium hydride (60% oil suspension) was added to dimethyl sulfoxide (1 ml, DMSO) and stirred at room temperature for 3 hours. A solution of 585 mg (2 mmol) of sulfone (I) in DMSO (6 ml) was added dropwise thereto at the same temperature and stirred for 1 hour. Then a solution of 211 mg (1 mmol, purity 96%) of allyl halide (II) in DMSO(2 ml) was added dropwise thereto in 1 minute and kept at the same temperature for 5 minutes under stirring. After the reaction, water was added to the reaction solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order, dried over anhydrous magnesium sulfate, and then filtrate was evaporated to give a crude yellow oil product. The obtained crude product was analyzed by HPLC to show that the yield of sulfone compound (III) was 37.6%.
Example 9
To a solution of 116 mg (1.2 mmol) of sodium t-butoxide dissolved in DMF (6 ml) and cooled to 0° C. was added dropwise a solution of 585 mg (2 mmol) of sulfone (I) in DMF (4 ml) over 20 seconds and 22 mg (0.1 mmol) of 15-crown-5 was added thereto and kept for 5 minutes. A solution of 215 mg (1 mmol, purity 96%) of allyl halide (II) in DMF(4 ml) was added thereto in 5 minute and stirred at the same temperature for 3 hours. After the reaction, the reaction solution was poured into an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order, dried over anhydrous magnesium sulfate, and then filtrate was evaporated to give a crude yellow oil product. The obtained crude product was analyzed by HPLC to show that the yield of sulfone compound (III) was 69.6%
Example 10
The experiment was conducted in a similar manner as in Example 9 except that 38 mg of tetrabutyl ammonium iodide was used in place of 15-crown-5. The obtained crude product was analyzed by HPLC to show that the yield of sulfone compound (III) was 65.2%.
Example 11
To a solution of 116 mg (1.2 mmol) of sodium t-butoxide dissolved in DMF (5 ml) and cooled to −20° C. was added dropwise a solution of 585 mg (2 mmol) of sulfone (I) in DMF (4 ml) and stirred for 5 minutes at the same temperature. After cooling the solution to −30° C., a solution of 269 mg (1 mmol) of allyl halide (V) in DMF (2 ml) was dropwise added thereto and stirred for 2.5 hours. After the reaction, water was added to the reaction solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order, dried over anhydrous magnesium sulfate, and then filtrate was evaporated to give a crude yellow oil product. The obtained crude product was purified by thin layer silica gel chromatography to give sulfone compound (VI) in a yield of 69.5%.
Sulfone (VI)
1 H-NMR δ (CDCl 3 ); 0.82(3H, s), 1.08(3H, s), 1.39(3H, s), 1.39-1.70(4H, m), 2.03(3H, s), 2.00-2.22(2H, m), 2.41(3H, s), 2.68(1H, dd, J=7 Hz, 14 Hz), 3.05(1H, dd, J=7 Hz, 14 Hz), 3.93(1H, t, J=7 Hz), 4.70(2H, d, J=7 Hz), 5.51(1H, t, J=7 Hz), 7.27-8.04(9H, m)
Example 12
9 mg of palladium chloride (0.05 mmol), and 178 mg (1 mmol) of sodium p-toluenesulfinate were suspended in 2 ml of methanol under nitrogen atmosphere. After a solution of 62 mg (0.2 mmol) of triphenylphosphite and 211 mg (0.5 mmol, purity 98.3%) of sulfone(III) in tetrahydrofuran (2 ml) was added thereto and stirred for 1.5 hours at room temperature, the mixture was warmed to 60° C. and stirred for 5.5 hours. After the reaction, water and an aqueous saturated sodium chloride solution were poured thereto and extracted with ethyl acetate. The obtained organic layer was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude product. HPLC analysis of the product showed that the yield of allylsulfone compound (VII) was 89.1%.
Allyl Sulfone Drivative (VII)
0.75(3H*70/100, s), 0.98(3H*70/100, s), 0.78(3H*30/100, s), 1.00(3H*30/100, s), 1.15(3H, s), 1.26-1.61(7H, m), 1.98(3H*70/100, s), 2.00(3H*30/100, s), 2.44(3H, s), 2.55(3H, s), 2.57-3.06(2H, m), 3.62-3.68(1H, m), 3.82-3.87(1H, t, J=8 Hz), 5.18-5.23(1H, t, J=8 Hz), 7.26-7.35(4H, m), 7.66-7.78(4H, m)
Example 13
9 mg of palladium chloride (0.05 mmol), 54 mg (0.2 mmol) of triphenylphosphine, 250 mg (1 mmol) of sodium p-toluenesulfinate tetrahydrate, and 211 mg (0.5 mmol, purity 98.3%) of sulfone compound (III) were suspended in 3 ml of methanol and 3 ml of toluene and stirred at 60° C. for 4 hours. After the reaction, water was poured into the reaction mixture and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated ammonium chloride solution and an aqueous saturated sodium chloride solution in this order, and dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporate to give a crude product. HPLC analysis of the product showed that the yield of allylsulfone compound (VII) was 78%.
Example 14
9 mg of palladium chloride (0.05 mmol), and 254 mg (1 mmol) of sodium p-toluenesulfinate tetrahydrate were suspended in methanol (1 ml). A solution of 52 (0.2 mmol)mg of triphenylphosphine, 211 mg (0.5 mmol, purity 98.3%) of sulfone compound (III) and 60 mg (1 mmol) of acetic acid in toluene (3 ml) was added thereto and stirred for 3 hours at 60° C. for 3 hours. After the reaction, water and an aqueous saturated sodium chloride solution were poured into the reaction mixture and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated ammonium chloride solution and an aqueous saturated sodium chloride solution in this order, and dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude product. HPLC analysis of the product showed that the yield of allylsulfone compound (VII) was 76.9%.
Example 15
2.6 mg of palladium chloride (0.015 mmol), 156 mg (0.6 mmol) of triphenylphosphine, and 452 mg (1.8 mmol) of sodium p-toluenesulfinate tetrahydrate were suspended in methanol (1 ml), and 46 mg (0.45 mmol) of triethylamine and toluene 3 ml were added thereto and stirred at 60° C. at 10 hours. After the reaction, water was poured into the reaction mixture and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated ammonium chloride solution and an aqueous saturated sodium chloride solution in this order, and dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude product. HPLC analysis of the product showed that the yield of allylsulfone compound (VII) was 74%.
Example 16
4.9 mg of palladium chloride (0.028 mmol), 151.6 mg (0.61 mmol) of sodium p-toluenesulfinate tetrahydrate, 211.9 mg (99.6%, 0.5 mmol) of sulfone compound (III), 124.3 mg (0.2 mmol) of tris(tridecyl)phosphite and 16.2 mg (0.16 mmol) of triethylamine were dissiolved in methanol (1 ml) and toluene (3 ml) and stirred at 60° C. for 6 hours. After the reaction, water was poured into the reaction mixture and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated ammonium chloride solution and an aqueous saturated sodium chloride solution in this order, and dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude product. HPLC analysis of the product showed that the yield of allylsulfone compound (VII) was 83%.
Example 17
A solution of 47 mg (0.49 mmol) of sodium t-butoxide in DMF (6 ml) was cooled to 0° C. and a solution of 196 mg (0.38 mmol) of allyl sulfone compound (VII) in DMF (3 ml) was dropwise added thereto in 5 seconds and maintained at the same temperature for 2 minutes. Then, the reaction mixture was cooled to −60° C. and 88 mg (0.41 mmol, purity 96%) of allyl halide (II) in DMF (3 ml) was dropwise added thereto in 20 seconds and stirred for 3 hours. After reaction, the reaction mixture was poured into an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order. The solution was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude yellow product, which was analyzed by HPLC to show that the yield of disulfone (VIII) was 92.8%.
Disulfone Compound (VIII)
1 H-NMR δ (CDCl 3 ); 0.66-1.69(21H, m), 1.91-2.04(3H, m), 1.91-2.04(2H, m), 2.43(3H, s), 2.45(3H, s), 2.52-3.11(2H, m), 3.58-3.94(2H, m), 4.35-4.50(2H, m), 4.86-4.94(1H, m), 5.18-5.38(1H, m), 7.28-7.39(4H, m), 7.65-7.79(4H, m)
Example 18
19 mg (0.48 mmol) of sodium hydride (60%, oil suspension) was dissolved in DMF (6 ml) and cooled to 0° C. A solution of 190 mg (0.37 mmol) of allyl sulfone compound (VII) in DMF (3 ml) was dropwise added thereto over 20 seconds and maintained for 20 minutes. Then, a solution of 88 mg (0.41 mmol purity 96%) of allyl halide (II) in DMF (3 ml) was dropwise added thereto in 5 minutes and allowed to stand at room temperature under stirring for 3 hours. After reaction, the reaction mixture was poured into an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order. The solution was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude yellow product, which was analyzed by HPLC to show that the yield of disulfone (VIII) was 94.8%.
Example 19
To a solution of 21 mg (0.53 mmol) of sodium hydroxide and 4.5 mg 0.02 mmol) of benzyltriethylammonium chloride in DMF (6 ml) was dropwise added a solution of 211 mg (0.41 mmol) of allyl sulfone compound (VII) in DMF (3 ml) at room temperature in 20 seconds and maintained at the same temperature for 20 minutes. Then a solution of 88 mg (0.41 mmol, purity 96%) of allyl halide (II) in DMF (3 ml) was dropwise added thereto over 20 seconds and stirred for 3 hours. After reaction, the reaction mixture was poured into an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order. The solution was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude yellow product, which was analyzed by HPLC to show that the yield of disulfone (VIII) was 60.8%.
Example 20
To a solution of 46 mg (0.82 mmol) of potassium hydroxide and 4.5 mg (0.02 mmol) of benzyltriethylammonium chloride in DMF (6 ml), which was cooled to 0° C., was dropwise added a solution of 211 mg (0.41 mmol) of allyl sulfone compound (VII) in DMF (3 ml) at room temperature in 20 seconds and maintained at the same temperature for 20 minutes. Then a solution of 88 mg (0.41 mmol, purity 96%) of allyl halide (II) in DMF (3 ml) was dropwise added thereto over 20 seconds and stirred for 3 hours. After reaction, the reaction mixture was poured into an aqueous saturated ammonium chloride solution and extracted with ethyl acetate. The obtained organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution and an aqueous saturated sodium chloride solution in this order. The solution was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated to give a crude yellow product, which was analyzed by HPLC to show that the yield of disulfone (VIII) was 68.1%.
Example 21
To a solution of 192 mg (0.3 mmol) of disulfone compound (VIII) in toluene (2 ml, BHT content: 300 ppm) was added 500 mg (9 mmol) of 95% potassium hydroxide, 19 mg of methanol (0.6 mmol), and 3 mg (0.015 mmol) of benzyltriethylammonium chloride were added thereto and stirred for 1 hour at 30° C. After the reaction, an aqueous saturated sodium chloride solution was poured into the reaction mixture and extracted with ethyl acetate, The obtained organic layer was washed with water, an aqueous saturated sodium chloride solution in this order and dried over anhydrous sodium sulfate. The dried solution was filtered and evaporated to give a crude retinol as a reddish oil. The obtained crude retinol was acetylated by a conventional manner and analyzed by HPLC to show that the yield of retinol acetate (IX) was 63.3%.
Example 22
To a solution of 256 mg (0.4 mmol) of disulfone compound (VIII) in hexane (2 ml, BHT content: 300 ppm) were added 240 mg (4 mmol) of 95% potassium hydroxide, 7 mg of methanol (0.2 mmol), and 4 mg (0.02 mmol) of benzyltriethylammonium chloride and stirred for 18 hours at 30° C. After the reaction, an aqueous saturated sodium chloride solution was poured into the reaction mixture and extracted with ethyl acetate. The obtained organic layer was washed with water, an aqueous saturated sodium chloride solution in this order and dried over anhydrous sodium sulfate. The dried solution was filtered and evaporated to give a crude retinol as a reddish oil. The obtained crude retinol was acetylated by a conventional manner and analyzed by HPLC to show that the yield of retinol acetate (IX) was 91.3%.
Example 23
To a solution of 256 mg (0.4 mmol) of disulfone compound (VIII) in toluene (2 ml, BHT content: 300 ppm) was added 240 mg (4 mmol) of 95% potassium hydroxide, 27 mg of methanol (0.8 mmol), and 4 mg (0.02 mmol) of benzyltriethylammonium chloride were added thereto and stirred for 11 hours at 40° C. After the reaction, an aqueous saturated sodium chloride solution was poured into the reaction mixture and extracted with ethyl acetate. The obtained organic layer was washed with water, an aqueous saturated sodium chloride solution in this order and dried over anhydrous sodium sulfate. The dried solution was filtered and evaporated to give a crude retinol as a reddish oil. The obtained crude retinol was acetylated by a conventional manner and analyzed by HPLC to show that the yield of retinol acetate (IX) was 89.3%.
Example 24
To a solution of 256 mg (0.4 mmol) of disulfone compound (VIII) in diisopropyl ether (2 ml, BHT content: 300 ppm) was added 240 mg (4 mmol) of 95% potassium hydroxide, 27 mg of methanol (0.8 mmol), and 4 mg (0.02 mmol) of benzyltriethylammonium chloride were added thereto and stirred for 16 hours at 30° C. After the reaction, an aqueous saturated sodium chloride solution was poured into the reaction mixture and extracted with ethyl acetate. The obtained organic layer was washed with water, an aqueous saturated sodium chloride solution in this order and dried over anhydrous sodium sulfate. The dried solution was filtered and evaporated to give a crude retinol as a reddish oil. The obtained crude retinol was acetylated by a conventional manner and analyzed by HPLC to show that the yield of retinol acetate (IX) was 94.7% | There are disclosed a disulfone compound of formula (1):
wherein Ar denotes an aryl group that may have a substituent, R1 denotes a hydrogen atom or a protective group of a hydroxyl group and the wavy line means that the disulfone compound is an E or Z geometrical isomer or a mixture thereof,
a method for producing the same,
intermediate compounds therefore and
a process for producing retinol through the disulfone compound. | 2 |
BACKGROUND OF THE INVENTION
This is a division, of application Ser. No. 640,646, filed Dec. 15, 1975 now U.S. Pat. No. 4,059,216.
The present invention relates generally to an electrolytic cell of the filter press type wherein a series of bipolar electrodes with diaphragms or membranes sandwiched in between can be used for electrochemical production of alkali metal hydroxides and halogens. More particularly, the present disclosure relates to an improved method for connecting the backplates of the bipolar electrodes by welding a metal laminate strip therebetween to provide the essential electrical and mechanical connection while leaving sufficient air space to allow hydrogen gas to escape from within the cell, preventing hydrogen embrittlement of the titanium anode backplate.
Chlorine and caustic (sodium hydroxide) are essential and large volume commodities which are basic chemicals required in all industrial societies. They are produced almost entirely by the electrolysis of aqueous solutions of alkali metal chlorides, with a major proportion of current production coming from the diaphragm type electrolytic cells. These cells generally have a plurality of electrodes disposed within the cell structure to present a plurality of rows of alternatively spaced anodes and cathodes. These electrodes are generally foraminous in nature and made of a mesh or expenaded metal material so that a hydrauliclly permeable diaphragm may be formed over the cathode. This compartmental cell structure allows fluid flow through the cell. Brine (sodium chloride solution) starting material is continuously fed into the cell through the anode compartment and flows through the diaphragm backed by the cathode. To minimize back-diffusion and migration through the hydraulically permeable diaphragm, the flow rate is always maintained in excess of the conversion rate so that resulting catholyte solution has unreacted alkali metal chloride present. This catholyte solution, containing sodium hydroxide, unreacted sodium chloride, and certain other impurities, must then be concentrated and purified to obtain a marketable sodium hydroxide commodity and a sodium chloride solution to be reused in the diaphragm electrolytic cell. This is a serious drawback since the costs of this concentration and purification process are rising rapidly.
With the advent of technological advances such as the dimensionally stable anode which permits ever narrowing gaps between the electrodes and the hydraulically impermeable membrane, other electrolytic cell structures are being considered. The geometry of the diaphragm cell structure makes it inconvenient to place a planar membrane between the electrodes, hence the filter press electrolytic cell structure with planar electrodes has been proposed as an alternate electrolytic cell structure.
A filter press electrolytic cell is a cell consisting of several units in series, as in a filter press, in which each electrode, except the two end electrodes, acts as an anode on one side and a cathode on the other, and the space between these bipolar electrodes is divided into anode and cathode compartments by a membrane. In a typical operation, alkali metal halide is fed into the anode compartment where halogen gas is generated at the anode. Alkali metal ions are selectively transported through the membrane into the cathode compartment, and combine with hydroxyl ions generated at the cathode by the electrolysis of water to form the alkali metal hydroxides. In this cell the resultant alkali metal hydroxide is sufficiently pure and concentrated to be commercially marketable, thus eliminating an expensive second step of processing. Cells where the bipolar electrodes and the diaphragms or membranes are sandwiched into a filter press type construction may be electrically connected in series, with the anode of one connected with the cathode of an adjoining cell through a common structural member of partition. This arrangement is generally known as a bipolar configuration. A bipolar electrode is an electrode without direct metallic connection with the current supply, one face of which acts as an anode and the opposite face as a cathode when an electric current is passed through the cell.
While the bipolar configuration provides a certain economy for electrical connection of these electrodes in series there is a serious problem with the corrosion of cell components in contact with the anolyte. The anolyte normally contains highly corrosive concentrations of free halide, and the use of base metals such as iron to contain the solution have proven to be ineffective.
Proposals to overcome this problem include utilizing valve metals or alloys thereof to contain anolyte, either by fabricating an entire electrode from such a corrosion resistant material or by bonding a coating of valve metal onto a base metal within the anolyte compartment. The use of large quantities of expensive valve metals in commercial cell construction though has proven to be economically undesirable. The coated base metals on the other hand are prone to distintegration by peeling off of the protective layer and have also proven ineffective. It has been found that use of an air space between the backplates will act as an insulation against hydrogen ion travel and the resulting hydrogen embrittlement, because the hydrogen ions combine to form molecular hydrogen more readily than the ions move through the air space. Molecular hydrogen can then be simply vented off. This provides a convenient means for solving the embrittlement problem but leaves the problem of properly connecting the backplates in parallel spaced relation to each other. Welding would be ideal except that heretofore only insufficient methods were available for welding different metallic materials together such as steel and titanium.
Electrical and mechanical connection of these bipolar electrodes has been accomplished by internal bolting systems wherein the electrode is bolted through one pan, providing a spaced relation by use of a spacer of some sort, and through the second pan to the other electrode. Another method employs the use of an external bus-bar, outside of the electrolytic cell structure. Electrical connections made by the internal bolting systems are undesirable because elaborate sealing schemes are necessary to prevent electrolyte leakage which could result in an extreme corrosion of the cathode compartment. This increases the cell costs and necessitates frequent maintenance. Electrical connections made externally are also not desirable since larger power losses are occasioned by the added structural voltage drops.
Thus it has become exceedingly advantageous to provide a method for connecting the bipolar electrode backplates in a spaced relation at a commercially viable cost.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a bipolar electrode which is capable of insertion into a filter press electrolytic cell that will have a greatly simplified means of connecting the two backplates to provide a bipolar electrode capable of withstanding commercial electrochemical production at a significantly reduced manufacturing cost.
It is another object of the present invention to provide an improved method for electrically and mechanically connecting the anode and cathode backplates of a bipolar electrode wherein a good current efficiency is achieved such commercial electrochemical production would be facilitated thereby.
These and other objects of the present invention, together with the advantages thereof over existing and prior art forms which will become apparent to those skilled in the art from the detailed disclosure of the present invention as set forth hereinbelow, are accomplished by the improvements herein shown, described and claimed.
It has been found that the anode and cathode backplates of a bipolar electrode for use in a filter press electrolytic cell can be connected mechanically and electrically by placing a spaced series of metal laminate strips of identical and corresponding metallic makeup to the metallic makeup of the corresponding backplates upon one of said backplates, placing the other backplate in direct allgnment on top of this space series of metal laminate strips such that the backplates present two parallel planes in spaced relation to each other, and effecting a weldment between the spaced series of metal laminate strips and each of the backplates.
One preferred embodiment of the improved method for mechanically and electrically connecting the backplates of a bipolar electrode is shown by way of example in the accompanying drawings without attempting to show all of the various forms and modifications in which the invention might be embodied; the invention being measured by the appended claims and not by the details of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the anode and cathode pans of a bipolar electrode with the mechanical and electrical connection effected therebetween by the use of a space series of laminate metal strips welded therebetween according to the concepts of the present invention.
FIG. 2 is a partial side section view of a bipolar electrode taken substantially along line 2--2 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings numeral 10 refers generally to a bipolar electrode assembled according to the concepts of the present invention. The bipolar electrode 10 is made up of an anode backplate 12 to which is connected an anode 14 and a cathode backplate 16 to which is connected a cathode 18. Around the outer perimeter of the anode backplate 12 and cathode backplate 16 would be an appropriate frame or other means for clamping the bipolar electrode 10 into a filter press electrolytic cell not shown. The details of this environmental structure have not been shown for ease of illustrating the concepts of the present invention. The anode backplate 12 and cathode backplate 16 could have just as easily each been made from single sheets of material so as to form a panlike structure providing a flange around the peripheral edge of each backplate such that the series of bipolar electrodes 10 might be clamped into a filter press electrolytic cell in liquid tight sealing engagement. The anode 14 and cathode 18 are generally foraminous in nature and can be made of a mesh or expanded metal material of appropriate metallic substance. Such foraminous anodes 14 may be made of any conventional electrically conductive electrolytically active material resistant to the electrolyte such as graphite or more preferably what is known in the art as dimensionally stable anodes. Such dimensionally stable anodes have an electro-conductive surface, e.g., a platinum group metal, an oxide of an platinum group metal, an anolyte resistant conductive oxide of a metal, and anolyte resistant conductive oxide of several metals, or the like on a valve metal base. The valve metals are those metals which form non-conducting oxides which are resistant to the anolyte when exposed thereto. The valve metals include titanium, zirconium, hafnium, vanadium, niobium, tantalum and tungsten. The foraminous anode 14 shown in FIG. 1 is generally preferred because their greater electrolytically active surface areas facilitate the electro-chemical reaction and the flow within the electrolytic cell. Generally the anode backplate 12 and anode 14 will be made of the same material such that conventional weldments may be accomplished between the anode backplate 12 and anode 14 as seen in FIG. 1. Th term "conventional weldments" is meant to include: soldering, brazing, arc welding, tig welding, tig with metal added or mig welding, and resistance or spot welding among other methods of welding. The cathode 18 also foraminous in nature may be made of any conventional electrically conductive material resistant to the catholyte, examples being iron, mild steel, stainless steel, MONEL containing 70 percent nickel and 30 percent copper, nickel and the like. The cathode backplate 16 is likewise made of the same material as the cathode 18 such said conventional weldments may be accomplished between the cathode 18 and cathode backplate 16. The anode backplate 12 will generally have a thickness of 0.020 to 0.125 inch (0.508 to 3.175 mm) when titanium is used for the backplate. The cathode backplate is generally a supporting structure for the bipolar electrode and is slightly thicker being in the thickness range of 0.080 to 0.75 inch (2.032 to 19.05 mm) especially when steel is used.
This results in a bipolar electrode 10 which has structural integrity due to the heavier steel plate used for the cathode backplate 16 while making an economical and efficient use of the chemically resistant titanium for the anode backplate 12. Titanium is a desirable valve metal for use in the anode 14 and anode backplate 12 because the anode compartment of an electrolytic cell contains an anolyte which normally has highly corrosive concentrations of free halide which can cause corrosion to most base metallic substances. As seen in the drawings the foraminous anode mesh 14 and foraminous cathode mesh 18 are both formed with channels 20 along their length such that convenient points are presented for weldment thereof to the backplates. Numerous other means for connecting the anode 14 and cathode 18 to the anode backplate 12 and cathode backplate 16 respectively have been proposed, including the use of riser posts of the same metal to span the gap between a planar electrode and a planar backplate.
Since it is believed that hydrogen ions generated at the cathode 18 migrate to the anode backplate 12 and anode 14 causing hydrogen embrittlement, it is necessary to leave some kind of barrier to these ions between the anode backplate 12 and the cathode backplate 16. Any insulative material can be used which will resist the flow of atomic hydrogen therethrough and it has been found that air provides such an insulative property since the hydrogen generally combines to form molecular hydrogen which is vented off before the hydrogen ions reach the cathode backplate 16. Copper is a second example of a good insulative material that effectively resists the flow of atomic hydrogen therethrough. To provide this kind of insulative barrier, a means of mechanically and electrically connecting the anode backplate 12 to the cathode backplate 16 in a spaced relation is desirable. This can be accomplished by placing between the anode backplate 12 and cathode backplate 16 a spaced series of laminate metal strips 22. A sufficient number are used, such that 5 to 10 percent of the total surface area of the two backplates is in direct bonded contact for the electrical current to be transmitted therethrough. The remaining space can be filled with insulative material or an air space can be left to allow the venting of hydrogen to prevent hydrogen embrittlement of the titanium backplate. The laminate metal strips 22 must be substances capable of carrying the necessary amount of electrical current while providing an insulator against hydrogen ion movement. In addition, the laminate metal strips must be a sandwich of two or more metallic substances such that one surface thereof will be of identical metallic makeup to correspond to the anode backplate 12 and the other surface thereof being of identical and corresponding makeup as the cathode backplate 16. An example of this would be a laminate metal strip 22 made of a sandwich of titanium to match the titanium used for the anode backplate 12 and steel on the other side to match the cathode backplate 16 made of steel as seen in the drawings. In addition to each surface of the metal laminate strips 22 being identical and corresponding to the respective backplate, the metals of the metal laminate strips 22 must be compatible for some kind of effective bonding to one another or some intermediate metal compatible to each must be inserted therebetween to make up a three metal laminate. One example of incompatible materials is tantulum and steel. Metal laminate strips 22 for this combination can be made with copper sandwiched in between the tantulum and steel since copper is compatible with both tantulum and steel for effective bonding.
Use of the laminate metal strips 22 reduces the connection of the anode backplate 12 and cathode backplate 16 to a standard process of conventional welding between each backplate and the laminate metal strip 22. This drastically simplifies the operation of such connection while eliminating the need to pierce either of the backplates, which heretofore has presented a sealing problem. The bipolar electrode 10 may, for instance, be assembled by putting the anode 14 and anode backplate 12 together with the metal laminate strip 22 and effecting a spot weld along the various positions of the metal laminate strips 22 in a single pass through standard spot welding machinery. Thereafter the cathode 18 and cathode backplate 16 may be similarly joined with the metal laminate strips 22 conveniently along these strips such that an excellent mechanical and electrical connection therebetween is effected. This eliminates the need for the use of any studs or other materials which must be pressed through the backplates and also the sealing problems that go along with such methods.
In actual practice it has been found the electrical energies necessary for weldments of the various materials require a stepwise assembly operation. First the metal laminate strips 22 are welded to one backplate and then to the second backplate. Then the foraminous electrode materials are individually welded to their respective backplates. The only likely short cut to this procedure would be to simultaneously weld the metal laminate strips 22 and the foraminous electrode material to one of the backplates and then repeat the process for the second backplate.
Metal laminate strip 22 materials are available commercially in sheet form and coil form of varying widths from a number of manufacturers and can be either of the roll bonded variety or explosion bonded variety as long as the metals can be integrally bonded together such that identical and corresponding metals will be facing each backplate. Several manufacturers produce these materials in sheet form to specification with whatever metals are to be used for the respective backplates. These sheets can then be cut into strips of convenient widths to be used in the method of the present invention. Such composite materials made of steel and titanium are readily available.
Thus it should be apparent from the foregoing description of the preferred embodiment, that the method hereinshown and described accomplished the objects of the invention and solves the problems attendant to such methods in the past. | Disclosed is a method for electrically and mechanically connecting the backplates of a bipolar electrode to be used in a filter press electrolytic cell for electrochemical production. This method employs the use of a metal laminate strip having surfaces of metallic substances identical and corresponding to the metallic makeup of the given backplates which can be welded between the anode and cathode backplates using standard weldment procedures. The metal laminate strips are placed in a spaced series such that the anode and cathode backplates present two parallel planes in spaced relation to each other thereby leaving a space for the escape of hydrogen gas, preventing hydrogen embrittlement of the titanium anode backplate. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a structure for fixing an optical member to a holder, and more particularly to a structure for fixing an optical member to a holder by adhesive.
2. Description of the Related Art
As disclosed, for instance, in Japanese Unexamined Patent Publication No. 62(1987)-189783, there has been known a solid state laser in which a Nd-doped laser crystal is pumped with a semiconductor laser.
In such a solid state laser, an optical member such as an etalon is often provided in a resonator in order to make the oscillation mode a single longitudinal mode or to control polarizing direction.
A relatively small optical member such as an etalon is generally fixed to a holder which is larger than the optical member in size and is held in a predetermined position. FIG. 4 shows a conventional structure for fixing an optical member 2 to a holder 1. As shown in FIG. 4, in the conventional structure, the optical element 2 is bonded to the holder 1 substantially along the entire surface 2a facing the holder 1 except the portion opposed to an aperture 1a of the holder 1. The hatched portion in FIG. 4 represents the bonding area.
Though being simple, the conventional structure is disadvantageous in that the optical member can be deformed (warped) or broken when subjected to a temperature change due to difference in the linear expansion coefficient between the holder and the optical member. This problem is especially serious when the optical member is relatively small in thickness like the etalon or the optical member is apt to generate cleavage.
SUMMARY OF THE INVENTION
In view of the foregoing observations and description, the primary object of the present invention is to provide a structure which can fix an optical member without fear that the optical member can be deformed or broken even if subjected to a temperature change.
In accordance with the present invention, there is provided a structure for bonding an optical member to one surface of a holder characterized in that
at least a pair of grooves are formed on said one surface of the holder to leave therebetween an elevated portion which is smaller than the optical element in width and
the optical member is bonded to said one surface of the holder only at the elevated portion.
In the case where the linear expansion coefficient of the optical member varies depending on directions in the surface which is to be bonded to said one surface of the holder, it is preferred that said elevated portion be linear and the optical member be bonded to said one surface of the holder so that the optical member has a linear expansion coefficient close to that of the holder in the direction parallel to the longitudinal direction of the elevated portion.
In the optical member fixing structure of the present invention, the grooves reduces the bonding area between the holder and the optical member, and accordingly stress acting on the optical member due to the difference in the linear expansion coefficient between the holder and the optical member when the holder-optical member assembly is subjected to a temperature change is suppressed, whereby the optical member is prevented from being deformed or broken.
Though the bonding area between the holder and the optical member may be reduced by applying adhesive only a limited part or limited parts, this approach is disadvantageous in that since the adhesive is spread when the optical member is pressed against the holder, it is difficult to control the bonding area to a desired value.
To the contrast, in the structure of the present invention, the adhesive spread when the optical member is pressed against the holder enters the grooves and is not available for bonding the optical member to the holder, and accordingly the bonding area can be precisely controlled.
Further in the longitudinal direction of the elevated portion, the bonding length is larger than that in the direction transverse to the elevated portion and accordingly stress acting on the optical member is apt to be large in the longitudinal direction of the elevated portion. However when the optical member is bonded to the holder so that the optical member has a linear expansion coefficient close to that of the holder in the direction parallel to the longitudinal direction of the elevated portion, the stress can be smaller. On the other hand, the difference in the linear expansion coefficient is larger in the direction transverse to the elevated portion. However in this direction, the bonding length is smaller by existence of the grooves as compared with that in the longitudinal direction of the elevated portion, whereby the stress acting on the optical member can be suppressed. Accordingly, excessively large stress cannot act on the optical member in a particular direction, whereby deformation and/or breakage of the optical member can be avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an optical member fixing structure in accordance with a first embodiment of the present invention,
FIG. 2 is a perspective view showing an optical member fixing structure in accordance with a second embodiment of the present invention,
FIG. 3 is a side view of the optical member fixing structure of the second embodiment, and
FIG. 4 is a perspective view showing an optical member fixing structure in accordance with a prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the first embodiment shown in FIG. 1, a quartz etalon 10 which is disposed, for instance, in a resonator of a semiconductor laser-pumped solid state laser to make the oscillation mode of the laser a single longitudinal mode is fixed to a holder 11 of copper.
The quartz etalon 10 is 2.4 mm×2.4 mm and 0.3 mm in thickness. The holder 11 is provided with an aperture 11a at the center thereof. A surface 11b of the holder 11 to which the etalon 10 is to be bonded is formed with a pair of linear grooves 11c in parallel to each other. The grooves 11c are 0.5 mm in width and spaced from each other by 0.5 mm. Accordingly an elongated elevated portion 11d 0.5 mm wide is left between the grooves 11b.
Epoxy adhesive is applied to the surface of the elevated portion 11d and the etalon 10 is bonded to the holder 11 by the adhesive. That is, in this embodiment, the bonding area (the hatched portion in FIG. 1) is only 2.4 mm×0.5 mm.
When the etalon 10 is pressed against the holder 11 with the adhesive sandwiched therebetween, the adhesive is spread. However the spread adhesive enters the grooves 11c and is not available for bonding the etalon 10 to the holder 11, and accordingly the bonding area can be kept substantially 2.4 mm×0.5 mm.
When the etalon 10 fixed to the holder 11 in the manner described above was employed to make the oscillation mode of a solid state laser beam 12 a single longitudinal mode at a wavelength λ of 1064 nm and was subjected to a preservation test of 70° C.×96 h. Warpage of the quartz etalon 10 was not larger than λ/10. For the purpose of comparison, a quartz etalon the same as the etalon 10 described above was bonded to a holder of copper over the entire area thereof and subjected to the same preservation test. Warpage of the quartz etalon was as large as λ/2 to λ/4. This shows that warpage of a quartz etalon can be suppressed by reducing the bonding area.
When warpage of the quartz etalon 10 can be suppressed, the wavelength selected by the etalon 10 cannot be changed with change in the environmental temperature, which results in stable drive of a semiconductor laser-pumped solid state laser.
Further as compared with spot bonding of the etalon 10 to the holder 11, the bonding structure of the embodiment described above is sufficient in the bonding area, which results in a sufficient bonding strength.
In the second embodiment shown in FIGS. 2 and 3, a calcite crystal plate 20 which is disposed, for instance, in a resonator of a semiconductor laser-pumped solid state laser to control polarization is fixed to a holder 11 of copper.
The calcite crystal plate 20 is 2.4 mm×2.4 mm and 0.34 mm in thickness. The holder 11 is the same as that employed in the first embodiment. Epoxy adhesive is applied to the surface of the elevated portion 11d and the calcite crystal plate 20 is bonded to the holder 11 by the adhesive. That is, also in this embodiment, the bonding area (the hatched portion in FIG. 2) is only 2.4 mm×0.5 mm.
The calcite crystal plate 20 has been cut along a plane inclined relative to c-axis by 46.7° toward a-axis as shown in FIG. 2, and since the inclined angle is close to 450°, an intermediate direction between a-axis and c-axis is included in the cut plane. The calcite crystal plate 20 is bonded to the holder 11 with the intermediate direction oriented in parallel to the longitudinal direction of the elevated portion 11d.
The calcite crystal plate 20 has a linear expansion coefficient of 0.544×10 -5 /°C. in the direction of a-axis and that of 2.63×10 -5 /°C. in the direction of c-axis. Since the linear expansion coefficient of the calcite crystal plate 20 may be considered to be the average of those in the directions of a-axis and c-axis and is 1.58×10 -5 /°C., which is very close to the linear expansion coefficient of copper, 1.67×10 -5 /°C.
When subjected to a temperature change, the calcite crystal plate 20 is apt to generate cleavage under stress acting thereon due to the difference in the linear expansion coefficient between the calcite crystal plate 20 and the holder 11. However in the structure of this embodiment, the bonding area between the plate 20 and the holder 11 is sufficiently small and the stress acting on the plate 20 is very small. Accordingly cleavage of the calcite crystal plate 20 can be prevented.
Further as can be understood from the description above, since the calcite crystal plate 20 is bonded to the holder 11 so that the plate 20 has a linear expansion coefficient close to that of the holder 11 in the direction parallel to the longitudinal direction of the elevated portion 11d, the stress acting on the plate 20 is more suppressed and cleavage of the plate 20 is prevented more surely.
Thus cleavage of the calcite crystal plate 20 can be prevented even if hard adhesive is used.
When the calcite crystal plate 20 fixed to the holder 11 in the manner described above was subjected to a preservation test of 70° C.×96 h described above. No cleavage was observed on the calcite crystal plate 20. To the contrast, when the calcite crystal plate 20 is bonded to the holder 11 over the entire area thereof, cleavage is often generated.
In order to prevent cleavage, it is preferred that soft adhesive be employed. However soft adhesive is limited in kinds and accordingly the structure of the present invention, which permits use of hard adhesive, increases freedom is selection of adhesive. | An optical member is bonded to one surface of a holder. At least a pair of grooves are formed on the surface of the holder to leave an elevated portion which is smaller than the optical element in width. The optical member is bonded to the surface of the holder only at the elevated portion. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to an optical low pass filter and, more particularly, to an optical low pass filter for use with an image sensing device, for example, a solid state image sensing device using a CCD (charge coupled device), an MOS (metal oxide semiconductor) device and the like which produces a predetermined image pickup output by carrying out the spatial sampling in two dimensions.
2. Description of the Prior Art
A color image pickup apparatus, or a color video camera using, for example, a CCD as the solid state image sensing device thereof is arranged to produce a predetermined color video output by sampling a color analyzed image of an object obtained through a color filter that is disposed at the front of the video camera.
In the image sensing system which produces a color signal by carrying out the color coding by the color filter and the spatial sampling at each color, it is well known that, based upon the side band component which is caused by the fact that sampling carrier is modulated by the sampling frequency component upon the sampling, an aliasing distortion will be produced. The generation of the carrier component which will cause such aliasing distortion is different dependent on the color coding.
FIG. 1A is a diagram showing an example of the alignment of picture elements of one-chip CCD image sensor 1 and the opening portion thereof. In FIG. 1A, reference numeral 2 designates the picture element of the image sensor 1, reference letter H designates the horizontal scanning direction thereof, reference letter V designates the vertical scanning direction thereof, reference letter Px designates an opening width in the horizontal direction of the CCD image sensor 1 and reference letter Py designates an opening width in the vertical direction thereof. When a color filter 3 in which 3 of longitudinal stripe-shape color filter elements of three primary colors R (red), G (green) and B (blue) are repeated as shown in FIG. 1B is used for the image sensor 1, carrier components, which will be mentioned below, will be generated.
The spatial sampling in the horizontal direction of Px and in the vertical direction of Py is expressed by the following equation (1)
ΣΣδ(x-mPx, y-nPy) (1)
where x and y designate horizontal and vertical coordinates respectively and m and n are both integers.
The carrier component produced by such spatial sampling is expressed by Fourier-transforming Eq. (1) and is presented as ##EQU1## where represents the Fourier transform and u and v represent the horizontal and vertical spatial frequencies, respectively.
Accordingly, carrier components F R , F G and F B of the three primary color signals R, G and B produced when the color filter 3 shown in FIG. 1B is used are expressed by the following equations (3), (4) and (5), respectively. ##EQU2##
The exp (-jPxu) and exp (-j2Pxu) in the carrier components F G and F B represent phase differences relative to the carrier component F R , respectively.
If such carrier components are shown on the spatial spectrum, they become as shown in FIG. 2. In FIG. 2, the abscissa f x and the ordinate f y represent the horizontal and vertical frequencies that are normalized by Px/2π and Py/2π, respectively. In the spatial spectrums, the length of the arrow represents the magnitude of the carrier component, and the direction of the arrow represents the phase difference among the carrier components.
From this spatial spectrums, it will be seen that in addition to the base band component with the position of (f x , f y )=(0, 0) as the center, the carrier components are produced respectively at the positions (f x , f y )=(1/3, 0), (2/3, 0), (1, 0), (0, 1/2), (0, 1) and so on as the center by the color separation sampling.
In the spatial spectrums of FIG. 2, there are only shown the carrier components which will cause the aliasing distortion and also the carrier components shown by broken lines if FIG. 2 are such ones which may be cancelled out by the electrical reading processing which will be described later.
The carrier components existing at the position of (1, 0) will cause a moire when an object with a narrow stripe pattern formed of black and white stripes extending in the vertical direction is picked up; the carrier components existing at the position of (2/3, 0) will cause a cross color which will present green and magenta colors when an object with a somewhat narrow longitudinal stripe pattern is picked up; and the carrier components existing at the position of (1/3, 0) will cause a cross color which will present green and magenta colors when an object with a little rough longitudinal stripe pattern is picked up.
In like manner, the carrier components existing at the position of (0, 1) will produce a moire when an object with a narrow horizontal stripe pattern is picked up, and the carrier components existing at the position of (0, 1/2) will cause a flicker to occur by the interlaced scanning when an object with a little rough horizontal stripe pattern is picked up.
In this case, however, the flicker caused by the carrier components existing at the position of (0, 1/2) can be electrically removed because the carrier components are cancelled out by reading out the CCD charge transfer device in the manner of a known field reading method (where two adjacent horizontal lines are read out simultaneously). For this reason, the quality of a picture is deteriorated mainly by the carrier components in the horizontal direction.
When a color filter of a pattern in which the color filter element of the primary color G is formed of longitudinal stripe and the color filter elements of the other primary colors R and B are formed of the color filter elements arranged in the line sequential manner is used as the color filter 3 shown in FIG. 1B, the fundamental lattice as shown in FIG. 3A is presented. As a result, the respective carrier components of the three primary colors R, G and B in the case of such color coding become as shown in FIG. 4 on the spatial spectrum.
Also in FIG. 4, there are shown the carrier components that are harmful for the signal processing, similarly to FIG. 2. The moire will be caused by particularly the carrier components existing at the positions of (f x , f y )=(1, 0) and (0, 1), while the cross color will be caused by the carrier components existing at the positions of (f x , f y )=(1/2, 0) and (0, 1/2). In the case of the color coding as shown in FIG. 3B, since the primary colors R and B are arranged in the line sequential manner, the signal charge can not be read out by the field reading manner unlike the above-described example. However, if the vertical interpolation is carried out by the signal processing system provided affer the sample-and-hold operation for color separation was carried out, the moire in the vertical direction can be reduced.
By the way, if the color filter 3 such as shown in FIG. 1B or 3B is used, the moire and the cross color are produced due to the carrier components of the three primary colors R, G and B particularly existing in the horizontal frequency f x direction. Therefore, in the prior art, an optical low pass filter is disposed in the optical system of the image pickup apparatus, whereby the spatial frequency response in the horizontal frequency is made as a low pass characteristic, thus the carrier components being suppressed.
As such prior art optical low pass filters, there are used such ones in which three crystal plates are laminated as disclosed in a published document of Japanese examined patent application No. 50336/1983 and a published document of Japanese unexamined patent application No. 39683/1982. In the prior art optical low pass filter disclosed in the published document of Japanese patent application examined No. 50336/1983 and in the prior art optical low pass filter disclosed in the published document of Japanese unexamined patent application No. 39683/1982, there are respectively provided the low pass characteristics shown in FIG. 12 and FIG. 17 thereof by properly selecting a projection angle relative to the horizontal scanning direction H and a separated distance d on the pickup surface at each optical axis thereof.
If the characteristic of the optical low pass filter is set as such optical low pass characteristic as described hereinabove, the carrier components existing at the positions after the position of (f x , f y )=(1/3, 0) are suppressed so that the occurrence of the moire and cross color can be reduced and the deterioration of the quality of picture can be improved.
By the way, such prior art optical low pass filters are formed by laminating three crystal plates. As is known, a crystal plate is very expensive, and when three crystal plates are laminated, they must be laminated under the condition that they are accurately positioned so as to make the projection angles of the optical axes equal to the designed values. This requires high accuracy in laminating the three crystal plates so that it is difficult to manufacture the optical low pass filter. Hence the yield thereof is considerably low and the workability thereof is poor.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide an optical low pass filter which can be manufactured easily and at low cost.
It is another object of this invention to provide an optical low pass filter which is excellent in yield and cost performance.
It is further object of this invention to provide an optical low pass filter which is suitable for being applied to the optical system of an image sensing apparatus using a solid state image sensing device formed of a CCD (charge coupled device), MOS (metal oxide semiconductor) or the like.
According to one aspect of the present invention, there is provided an optical low pass filter used in a video camera having a solid stage image sensing device and a color separating filter, said optical low pass filter comprising: a first double refraction plate being arranged to separate an incident light ray to an ordinary light ray and an extraordinary light ray which is displaced from said ordinary light ray by a distance d in a direction with an angle substantially equal to θ relative to the horizontal scanning direction of said solid state image sensing device, wherein cos 2θ=√2/3(0°<2θ<90°), and a second double refraction plate being arranged to separate an incident light ray to an ordinary light ray and an extraordinary light ray which is displaced from said ordinary light ray by a distance d in a direction with an angle substantially equal to -θ relative to the horizontal scanning direction of said solid state image sensing device, whereby said optical low pass filter has the spatial frequency characteristic having a first trap frequency u 1 and a second trap frequency 2u 1 .
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of the illustrative embodiment thereof to be read in conjunction with the accompanying drawings, throughout which like references designate the same elements and parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 3A are diagrams showing patterns of opening portions of prior art CCD image sensors, respectively;
FIGS. 1B and 3B are diagrams each showing an example of a color filter which can be used for the CCD image sensor, respectively;
FIGS. 2 and 4 are spectrum diagrams of spatial frequency in the carrier components produced when the above color filters are used, respectively;
FIG. 5 is a diagram showing an embodiment of an optical low pass filter according to this invention;
FIGS. 6A and 6B are diagrams useful for explaining the optical axis projection directions, respectively;
FIG. 7 is a diagram showing an example in which an incident light ray is separated into an ordinary light ray and an extraordinary light ray in accordance with this invention;
FIGS. 8A and 8B are diagrams showing projection components projected to the horizontal axis and vertical axis directions, respectively; and
FIGS. 9A and 9B and FIGS. 10A and 10B are respectively characteristic graphs of the horizontal and vertical frequency responses useful for explaining the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Now, an embodiment of an optical low pass filter according to this invention will hereinafter be described with reference to the drawings.
FIG. 5 is a diagram showing an example of the optical low pass filter according to this invention. In FIG. 5, reference numeral 10 generally designates the optical low pass filter and this optical low pass filter 10 is formed of two double refraction plates, i.e., crystal plates 10A and 10B in this embodiment.
As the first and second crystal plates 10A and 10B, there are used such ones whose separating distances d are equal to each other. The first crystal plate 10A is arranged such that as shown in FIG. 6A, its optical axis projection direction 13 relative to the pickup surface of the CCD image sensor 1 is selected to have an angle θ (first quadrant in this embodiment) relative to the horizontal scanning direction H. Whereas, the second crystal plate 10B is arranged such that as shown in FIG. 6B, its optical axis projection direction 14 relative to the pickup surface of the CCD image sensor 1 is selected to have an angle -θ (the fourth quadrant in this embodiment) relative to the horizontal scanning direction H.
Accordingly, the incident light ray on the first crystal plate 10A is separated to an ordinary light ray and to an extraordinary light ray with a distance d therebetween in the optical axis projection direction 13. In like manner, the light ray incident on the second crystal plate 10B emitted from the first crystal plate 10A is separated to an ordinary light ray and to an extraordinary light ray with the distance d therebetween in the optical axis projection direction 14.
An acute angle 2θ between the optical axis projection directions 13 and 14 is selected as
cos 2θ=√2/3 (6)
where 0°<2θ<90° is established.
Accordingly, the incident light ray on the first crystal plate 10A is primarily separated to the ordinary light ray o 1 and the extraordinary light ray e 1 which are equal in light intensity and are parallel to each other and these two light rays o 1 and e 1 therefrom become incident on the second crystal plate 10B in which each of them is separated to the ordinary light ray and the extraordinary light ray. Therefore, as shown in FIG. 7, from the second crystal plate 10B, there are emitted an ordinary light ray o 1 o 2 and an extraordinary light ray o 1 e 2 based on the ordinary light ray o 1 , and an ordinary light ray e 1 o 2 and an extraordinary light ray e 1 e 2 based on the extraordinary light ray e 1 , that is, totally four light rays are emitted from the second crystal plate 10B. FIG. 7 shows the relation among these light rays o 1 o 2 , o 1 e 2 , e 1 o 2 and e 1 e 2 and the shape formed by connecting these light rays become a lozenge as shown in FIG. 7 and the line formed by connecting the ordinary light ray o 1 o 2 and the extraordinary light ray e 1 e 2 becomes parallel to the horizontal scanning direction H.
The light intensities (powers) of these light rays become as expressed by the following EQ. (7) ##EQU3## where the light intensities of the ordinary light ray o 1 and the extraordinary light ray e 1 that are separated by the first crystal plate 10A become equal to each other so that e 1 =o 1 is established.
Next, if the components of the light rays separated as shown in FIG. 7 are respectively projected on the axes which are respectively in parallel to the horizontal and vertical axes, they become as shown in FIGS. 8A and 8B. In FIGS. 8A and 8B, the components indicated by the square equations express the powers of the ordinary light ray and the extraordinary light ray, respectively. In this case, the frequency response in the horizontal direction can be obtained in the similar manner to that shown in the published document of examined Japanese patent application No. 50336/1983.
If now the incident signal Si(t) is taken as 20 1 2 cos 2π ft, since e 1 =o 1 is established, the emitted signal So(t) is expressed by the following equation: ##EQU4## Therefore, the following Eq. (9) is obtained: ##EQU5## Since the spatial response is changed as f→u, the frequency response R H (u) in the horizontal direction becomes as
R.sub.H (u)=sin.sup.2 2θ+cos.sup.2 2θ cos (2πud cos θ) (10)
Similarly, the frequency response R V (v) in the vertical direction becomes as
R.sub.V (v)=cos.sup.2 2θ+sin.sup.2 2θ cos (2πvd sin θ) (11)
By the way, when an object image is subjected to the spatial sampling, in the case of FIG. 1B, the carrier components exist at the positions of (f x , f y )=(1/2, 0), (2/3, 0) and (1, 0). While the moire and the cross color occur due to the existence of the above carrier components as described hereinabove, it will be clear that upon reproducing a color picture, the quality of picture can be improved more by removing the occurrence of the cross color rather than the moire.
In view of these points, in accordance with this invention, in order that the occurrence of the cross color which will exert a strong influence on the quality of picture may be suppressed sufficiently, the frequency response in the horizontal direction shown by Eq. (10) is determined. Since the cross color occurs when the carrier components exist at the positions of (f x , f y )=(1/3, 0) and (2/3, 0), if in the frequency response R H (u) obtained from Eq. (10), for the first trap point (frequency) u 1 , the second trap point u 2 is selected to satisfy u 2 ≈2u 1 and u 1 is selected to be (f x , f y )=(f x1 , 0)=(1/3, 0) and u 2 is selected to be (f x , f y )=(2/3, 0), the above-described object can be achieved.
The angle θ which can provide u 1 and 2u 1 can be obtained as follows: From the condition of R H (u 1 )=R H (2u 1 )=0, if the following simultaneous Eq. (12) ##EQU6## is solved, the following Eq. (13) is obtained
cos 2θ=±√2/3 (13)
Since 2θ 1 <90° is established,
cos 2θ=√2/3 (14)
is established. The angle θ which can satisfy Eq. (14) becomes substantially 17.6°. At that time, if Eq. (14) is substituted into the first Eq. of the simultaneous equation (12), the relation which is expressed by the following equation (15) ##EQU7## can be obtained.
If the angle θ is selected so as to satisfy Eq. (14) and the separated distance d is selected in accordance with Eq. (15) such that the horizontal trap frequency u 1 coincides with (f x , f y )=(1/3, 0), the characteristic of the horizontal frequency response R H (u) becomes as shown in FIG. 9A and the characteristic of the vertical frequency response R V (v) at that time becomes as shown in FIG. 9B.
If the horizontal frequency characteristic of the optical low pass filter 10 is selected as shown in FIG. 9A, the carrier component is suppressed at the frequency of (f x , f y )=(1/3, 0) and (2/3, 0) so as to become zero. Therefore, even if there exist the carrier components at these frequencies, the cross color can be prevented from being produced. Accordingly, it is possible to prevent the reproduced picture image of the achromatic object image from being colored.
In addition, since even though the frequency response between the horizontal trap frequencies u 1 and u 2 is maximum but becomes less than 1/3 the maximum response lower than the u 1 , it is possible to lower the frequency response between u 1 and u 2 sufficiently.
When the horizontal frequency response R H (u) is selected to be the characteristic as shown in FIG. 9A, the frequency response becomes 1 at u 3 =3u 1 . In this case, however, taking the spatial frequency characteristic of the whole image sensing system including the optical lens system and the CCD image sensor in the image sensing device into consideration, the frequency response at u 3 =3u 1 is decreased by about 20% from that of the case of FIG. 9A. Therefore, if the carrier components exist at the frequency, u 3 , the quality of picture is deteriorated a little by the moire caused thereby. Of course, if the frequency of the trap point u 1 is selected to be higher than 4.5 MHz, it is possible to reduce the occurrence of the moire itself.
While in the above embodiment the angle 2θ is selected so as to satisfy the condition of 2θ≈35.2°, the above-described effects can not be achieved by other angles than one described hereinabove. For reference, the horizontal spatial response provided when the angle 2θ is selected so as to satisfy the condition of, for example, 2θ=45° is shown in FIG. 10.
If the condition of 2θ=45° is established, the horizontal direction response R H (u) is expressed as ##EQU8## If Eq. (16) is given as the schematic representation, this becomes as shown in FIG. 10A.
As shown in FIG. 10A, the points to be trapped exist at the positions of (f x , f y )=(f x1 , 0), (2f x1 , 0). If the separation distance d is selected such that the first trap point (frequency) u 1 provided when the 2θ=45° is established coincides with the position (f x1 , 0), it becomes a characteristic shown by a curve 21 in FIG. 10B. In this case, the position, f x1 =2f x1 is not only the trap point but also the horizontal residual response becomes 1 so that the carrier components can not be suppressed at all. As a result, it is not possible to suppress the cross color based on the carrier components existing at the position of (f x , f y )=(2/3, 0).
If the first trap point (frequency) u 1 provided when the condition of 2θ=45° coincides with the position (2f x1 , 0), it becomes a characteristic shown by a curve 22 in FIG. 10B. In this case, at the position of f x =f x1 , the horizontal residual response becomes 0.5. Thus at this trap point u 1 , the cross color can not be suppressed so effectively.
If the first trap point u 1 provided when the condition of 2θ=45° is established is selected to be intermediate between the f x1 and 2f x1 (the trap point is presented by the position (3/2 f x1 , 0)), it becomes a characteristic as shown by a curve 23 in FIG. 10B. In this case, the horizontal residual response at the position of f x1 and 2f x1 becomes 0.25 so that both carrier components can not be suppressed so effectively.
Because, in order to obtain the effective carrier suppressing effect, the horizontal residual response must be selected to be about lower than 0.1.
The above-described optical axis projection direction does not have to be selected as θ and -θ strictly relative to the horizontal scanning direction H but may be selected near θ and -θ. Further, the material for forming the double refraction plate is not limited to 2 crystal.
When the present invention is applied to the color filter 3 of the color coding shown in FIG. 3B, it will be seen from FIG. 4 that in the horizontal direction, the harmful carrier components exist at the positions of (f x , f y )=(1/2, 0) and (1, 0). Therefore, similarly to the embodiment as mentioned hereinabove, in order that the horizontal trap frequency u 1 may coincide with the position of (f x , f y )=(1/2, 0), the separation distance d is selected in accordance with Eq. (15). Furthermore, since as to the vertical direction, the field reading method can not be employed as the reading method for the charge transfer in the case of the R and B line sequential signals, the carrier components in the vertical direction can be reduced by carrying out the vertical interpolation processing in the signal processing system provided after the color separation and sample-and-hold operation, thus causing no trouble in practical use.
As set forth above, according to this invention, it is possible to provide the optical low pass filter 10 which can suppress the carrier component that is harmful for reproducing the picture image. In addition, according to this invention, since such optical low pass filter 10 can be formed by simply laminating the two crystal plates 10A and 10B, it is possible to reduce the number of the crystal plates to be used as compared with the prior art and it is also possible to laminate the crystal plates accurately and rapidly. Accordingly, it is possible to provide the optical low pass filter which is inexpensive, high in yield and excellent in cost performance.
Consequently, this optical low pass filter of this invention is very suitable for being applied to the optical system of the image sensing apparatus using the solid state image sensing device formed of the CCD, MOS and the like.
The above description is given on a single preferred embodiment of the invention but it will be apparent that many modifications and variations could be effected by one skilled in the art without departing from the spirits or scope of the novel concepts of the invention, so that the scope of the invention should be determined by the appended claims only. | An optical low pass filter used in a video camera having a solid state image sensing device and a color separating filter is disclosed, which includes a first double refraction plate being arranged to separate an incident light ray to an ordinary light ray and an extraordinary light ray which is displaced from the ordinary light ray by a distance d in a direction with the angle substantially equal to θ relative to the horizontal scanning direction of the solid state image sensing device, wherein cos 2θ=√2/3(0°<2θ<90°), and a second double refraction plate being arranged to separate an incident light ray to an ordinary light ray and an extraordinary light ray which is displaced from the ordinary light ray by a distance d in a direction with the angle substantially equal to -θ relative to the horizontal scanning direction of the solid state image sensing device, whereby the optical low pass filter has the spatial frequency characteristic having a first trap frequency u 1 and a second trap frequency 2u 1 . | 7 |
The conventional systems of operating, for instance, the windows of a car or the sliding roof of a car includes tipically an electric motor that operates the pulley and the cables of the operating assembly of the glass or electric window, forcing the glass to go up or down sliding by the interior of the corresponding guides and joints installed in the door or frame of the car.
Said systems usually carry the so-called anti-pinching systems, which consist in control means that normally act on the electric motor of the operating system when there is detected any eventual blocking of the glass of the window or sliding roof of the car.
There exist anti-pinching systems, so-called direct electronic anti-pinching systems, that may be applied to electric window, sliding roof or the like devices, essentially based in mounting a coating at the interior portion of the frame of the window of a car, provided with an optical fibre conductor. When the glass raises and finds an obstacle between the upper edge of same and the window's frame, for instance, the hand of a person, the glass press the obstacle against the coating of the frame. When this happens, the flux of ligth circulating by the optical fibre conductor is modified, in such a way that a signal is sent to control means that compare same with certain pre-estabilished reference values. This brings the stopping and reversion of the sense of advancement of the glass in its rise allowing the obstacle's liberation.
The object of the present invention consists in arranging improvements applicable to the indirect anti-pinching systems, i.e.; these that analize and control the operation of the motor. Said analysis is made in such a way that any change on predetermined anticipated values for predetermined situations is interpreted by the system as a possible pinching or anomaly of the normal operation of the system.
Generally speaking, an anti-pinching system according to the present invention comprises means for the control of the operation of the motor operating the window or the sliding roof of a car which are activated when detecting any variation in the normal operation of the system.
The improvements introduced in said anti-pinching system consist in that the said anti-pinching system is formed by a motor module, a reduction module and an electronic control module, being comprised said motor module by a motor with n poles. More precisely, the motor module is formed by a motor of at least eight poles. The electronic module is made up by Hall sensors intended for regulating the motor speed, sending a number of pulses for each turn of the motor. Said control means operate on said motor module either as a function of the turning speed of the motor itself or as a function of the intensity of the circulating current, stopping its operation and/or reversing the turning direction.
Said improvements offer a sure and efficient anti-pinching system, capable of satisfying the every time more stringent international standars relative to the automobile and to their user's safety, which require that the sensitivity of these systems is to be greater every day. With the improvements of the present invention these goals are achieved and, at the same time, it is possible to foresee and detect correctly any type of anomalous siuation of the system's operation.
In that sense, the improvements introduced on the indirect anti-pinching system object of the present invention provided with Hall sensors permit satisfying standards such as the american standard FMVSS118 which require a higher sensitivity of the system. The tests made in the United States with regard to such standard are made with a spring that shows a value of rigidity constant of:
k= 65* N /mm
corresponding to a value 6.5 times greater that the value of the spring's constant used in Europe for the same test, which implies that in Europe there is admited a softer spring than the used for the tests of the american standard, which is satisfied, in the other hand, by the system object of the present invention.
As it has been specified above, one of the improvements introduced in the present invention is the design of the motors of at least eight poles instead of the four poles of the earlier art. The number of poles, for instance eight, is a function of the desired precision, which is determined by the following equation:
( x/n lec)=( d t0 *π)/(1/ r*n/ 2)
where (x) is the vertical distance of the glass lecture, (nlec) the number of lectures, (d t0 ) the diameter of the drum of the electric window, (r) the gear's relation and (n) the pole's number. In this way, for an electric window with a drum of d t0 =50 mm and a gear relation R=1/73, it happens that for an eight poles motor there is obtained a lectures' resolution of every 0.54 mm, instead of every 1 mm as happens in the case of the conventional electric motors of four poles. Thus, every true of the motor shaft corresponds to 4 pulses of the Hall sensor and is approximately equal to a travel of 1.6 mm of the glass. In this way, the detection of a pinching is made every 0.54 mm of travel of the glass. The Hall sensors installed are of a type at 0°, instead of the conventional systems which furnish same with 180°.
According to the invention, the electronic module of the anti-pinching system includes a circuit provided with a transistor with a field effect of insulated door, a relay, a programmable microprocesor, condensers in a multi-layer plate and an EEPROM programmable memory which is able to compensate the mechanical effects produced by the mechanical deformation of the system by storing a new value for every cycle of stoppage of the window, which actualizes the anterior run of the upper and lower stoppage value.
The transistor of field effect of insulated door or of a metal-semiconductor oxide field of n type (MOSFET) is a tension component controlled by an entry and exit impedances very high (up to Ω 4 ). Said component includes a substrate in which are diffused two identical regions which are named source or fountain and drain, which are defined by two Ohmic contacts insulated from the substrate by diodes. The conductive way between the fountain and the source is called channel. The door is formed covering the region existing between the drain and the source with a coat of silicium dioxide over which is placed a metal plate. The tension applied determines which type n zone furnishes the electrons and is converted in the fountain whilst the other type n regiuon collects the electrons and is converted in the drain. The MOSFET works basically with a positive potential between the door and the source above named. This type of operation is named enriched operation. When the source is of the positive type, there is induced a type n channel between the source and the drain. An increase in the tension of the door increases the conductivity of the channel increasing therefore the current. In this way, the current between the drain and the source is modulated by the tension between the door and the source. The increases of the tension of the drain do not produce a proportional increase of the drain current, being same proportional to the variations of the door's tension. The electrons' flux from the fountain towards the drain is controlled by the voltage applied to the door. A positive voltage applied to the door lures the electrons towards the contact zone between the dielectric of the door and the semiconductor, which form a conduction channel between the fountain and the drain called inversion coat. The net result is that the current between the drain and the fountain is controlled by the voltage applied to the door.
A minimum requirement for the amplification of electric signs is the energy gain. It has been found that a device with tension and current gain is a very desirable circuit element. The MOSFET provides tension and current gains with an output performance towards an exterior charge exceeding the entry current and an exit tension through the exterior charge wich excels the entry tension. The tension gain of a MOSFET is caused by the fact that the current is saturated at higher tensions of the drain-fountain, in such a way that a small variation of the drain current may cause a great variation of the tension of the drain. This permits cutting away the commutation current peaks, offering a greater speed and precision of reponse to the anti-pinching system, also favouring the ammelioration of the consumption and the reduction of the parasitic currents and noises (electromagnetic emmissions). Since the motor stops before the action of the relay, the precision is higher. The invention envisages also that the electronic module of the anti-pinching system further includes a micro-controller with a mask for the programming of the application once the components are assembled. In grace to this feature, it's possible programming the application at the assembly line of the components itself. Further, there is produced a greater flexibility for updating the programs and there exists the possibility of updating the software of the application in the final assembly line, retailers, sales points, trials, etc. The access to the data of the software is very agile modifying EEPROM memory values.
The plate furnished in the new anti-pinching system allows a considerable reduction of the consumption, specially every time that the relay is activated, cutting the current peaks. In this way, at a stand-by state, which is produced when stopping the car or after 10 minutes of having disconnected the motor or else after opening the door or after operating the door locking device (closing the door without waiting time), the nominal consumption is 180 μA; whilst for an idle state (active electronics but with the motor stopped), the nominal consumption is 18 μA and, in operation, the nominal consumption is 80 μA.
It must be taken specially into account the fact that the vehicles include every day more electric and electronic components and, at the same time, there exists a need of reducing the size of the batteries regarding weight and costs. Thus, even if the consumption in itself of these systems is unimportant, it becomes so when are considered all the several types systems of electric and electronic technology that incorporates the automobile, therefore it's noticeably important said consumption reduction of the anti-pinching system of the present invention.
In the other hand, the electronic module of the anti-pinching system incorporates control means for the temperature of the system starting from the number of turns of the motor shaft during a given time taking into account the consumption of the system. When a predetermined value is exceeded, said control means of the temperature of the system allow only the raising of the window.
Advantageously, the electronic module of the anti-pinching system incorporates means for regulating the maximum travel of the window, which, when connecting the motor, are counting the number of pulses read by the Hall sensor, disconecting said motor when certain given value is exceeded without the window arriving to the stopper.
Another of the improvements introduced in the anti-pinching system of the invention is that the electronic module incorporates disconnection means when the window is at a safety distance before the lower end of the stroke stopper, achieving the remainder of the course by the inertia of the window. In this way, it is possible performing a soft stop in a variable way as a function of two parameters which have not been considered so far by the conventional systems. Said parameters are the feeding tension, the speed of descent of the glass and the consumption of the system. There must be taken specially into account the fact that the conventional anti-pinching systems only take into account the feeding tension and the speed of descent of the glass.
The soft stop function is performed both at the upper stop position as well at the lower stop position. In the upper stop position, the motor raises the glass in such a way that the lenght of the actuating cable provokes that said glass achieves a height up to a distance before arriving to the upper stopper of the door frame. Said distance is traveled, until arriving to the upper stopper of the window's frame, in grace to springs assembled at the ends of the cable, which allow the drawing of the actuation length up to complete the travel of the window and provoking, therefore, a soft stop up to said upper stopper of the vehicle window frame. An electric window thus conceived becomes very elastic.
In this sense, when the glass reaches the upper or lower stopper of the window frame, the motor continues working until 0.5 s are elapsed. During this period of time there exists a drawing of the mechanical transmission which is variable as a funcion of the feeding tension. The drawings lecture in the upeer stopper as a function of the voltage of the battery are as follows:
For 12 V, the drawing is of 39 pulses=9.25 mm
For 14 V, the drawing is of 50 pulses=12.5 mm
For 17 V, the drawing is of 64 pulses=16 mm
This function of soft upper stop permits limiting the drawing of the mechanical transmission of the electric window noticeably improving the useful life of the mechanical elements of the system of the invention, reducing the wear and mechanical blockings. Since there is not attained a limit of mechanical drawing of said transmission, the consumption of the electric motor is reduced and, therefore, the battery is not damaged and there exist a greater stability of the electric circuit, avoiding that other devices are affected by tension falls.
In order to prevent a sudden stoppage at the lower position, the motor is disconnected, first by the MOSFET and afterwards with the relay, at a safety distance before the lower mechanical stoppage. Taking into account that the operating speed of the electric window, and therefore, the descent inertia are affected by several factors such as the feeding and consumption tension, the state of the vehicle motor (stopped or running), wheter the motor is of the rigth or left side, the mechanical construction of the electri window system and the door, the environmental conditions, etc., there is made an automatic adjustment of the soft stoppage taking into account the descent speed (three different ranges), wheter the vehicle is running or stopped (tension greater or lower than 13 V) and the consumption. For this fine tuning there are taken several doors in different climatic conditions and it is verified during the fatigue test.
The disconnection means of the motor take into account at least some of the factors such as the speed of descent of the window, the state working/idle of the motor and the consumption; automatically adjusting the disconnection of the motor as a function of such factors.
The protection against surcharge of the motor of the system of raising the glasses is made by means of a software. This temperature control software of the anti-pinching system is active even if the electric window is not yet initialized. The operating time of the electric window is accumulated and when it exceeds a estabilished limit value there is only allowed raising the window up to the upper stoppage. The rest time until a new operation is permitted is aproximately five times the operating time elapsed. This value is obtained in a exprimental way as per specifications at different temperatures of the standards in force and depending on the motor type.
In the practice and under normal working conditions, there should be possible 20 complete cycles of raising-lowering of the glass without a disconnection of the system. In any case, the protection for overheating must allow the raising of the glass up to the upper stoppage. Owing to the fact that the temperature of the motor is a function of its consumption, when more rough are the mechanical guides and the rubber guides of the electric window, greater will be the motor consumption for the operation of the glass. Under this circunstance, the temperature limit is variable. In this sense, there is estabilished a median consumption of the motor in the rise of 5 A, allowing 20 cycles of raising and lowering without disconnection. for a median consumption of 15 A, are allowed 5 cycles of raising and lowering without disconnection (system compensated by the consumption). With a consumption between 5 A and 15 A, the number of raising and lowering cycles is directly proportional to the consumption, in the range of 5 to 20 cycles.
When the motor arrives to the upper stopper of the rise or when it is stopped because of the eventual blocking by an object, it is detained in a reduced time. The detention time is of 0.2 seconds, i.e., the motor is desactivated after 0.2 seconds of the arrival of the glass to the end of run stopper, either in manual or automatic mode. This forms a contrast with the disconnection time of the former art systems which do it in 0.5 seconds. This minimal disconnection time is possible in grace to the arrangement of an n poles motor. for instance eigth poles, which offer a disconnection time noticeably lower than with four poles motors as used conventionally in the systems known. It must be understood that when performing the function of soft stopping when the glas is lowering, the motor is disconnected before arriving to the lower stopper.
Another limit of operation of the motor of the operating means of the system object of the invention is the consumption, which is limited to a maximum of 25 A.
If, during the raising of the glass, the vehicle starts, the anti-pinching system of the invention detects and filters the start of the car motor by a tension fall. This provokes the detention of the motor and the subsequent stopping of the glass. In grace to this feature, the system permits avoiding the production of a false pinching, since the fall in tension provokes a variation of speed that can be detected by the Hall sensors installed, in such a way that, before producing a false pinching, will provoke the detention of the motor.
In the other hand, the anti-pinching system of the invention takes into account whether the vehicle is stopped or running as per the feeding tension. If the feeding tension is lower than 13 V, it indicates that the vehicle has not started, therefore the sensitivity may be higher. Instead, if the feeding tension is greater than 13 V that indicates that the vehicle has started, by which the sensitivity is lower. It must be taken into account that when the vehicle is running, what limits the sensitivity are the possible “bumps” and that the impact of the glass inertia may provoke a false pinching. In case of having a feeding lower than 13 V it is assumed that said voltage is the furnished by the battery. Normally, when the motor is running, the feeding is superior to the tension furnished by the battery, since in this way is possible loading it and feeding the remainder of the systems present in the vehicle.
The system of the invention is also characterized by the geometry of the whole. It is a modular system comprising three independent modules and which may be dismantled between them. Said modules are: motor module, reducer module and electronic module. Unlike the conventional systems, in which there exists a void between the shaft and the Hall sensors, the system object of the present invention incorporates a plastic wall of the housing situated between the shaft and the ssensors. Further, between the gears and the electric motor are situated watertight joints.
According to the invention, the motor is able of performing a reverseal in the turning sense very short (in the order of miliseconds) when the glass is lowering. This provokes the blocking of the motor in reverseal, such as it was in raising. More precisely, every time that the glass stops during the descent journey, there is produced a rise pulse. The maximum value of this puse is of 0.53 mm and produces a blocking in the motor gears as if it was of rise. In this way, the motor stopping does not have inertia and the glass does not “sink” so much when leaning on.
The conventional systems show a low performance due to the irreversibility of the system. Said irreversibility is provoked by the transmission mechanical unit formed by a gear and an endless screw. Said mechanical unit is used in order to avoid the glass going down when pushing it. It has been seen that when the gear motor shows an electro-mechanical performance over 20% the “irreversibility” becomes reduced. In this way, it is possible to increase the performance of the motor and, therefore, its median consumption. this has a positive influence in the energetic consumption of the vehicle.
The maximum journey of motor activation is limited in order to avoid a continuous movement in case of a mechanical breakdown. For that object, when connecting the motor, the number of pulses read by the Hall sensor is counted. If it surpasses a quantity without arriving to the stopper, the operation of the motor is disconnected. In this sense, it is estabilisehed a maximum journey of 100 mm over the journey reference value of the glass of the system for raising the glass.
Is the glass raisin system has not been initialized there exist no limit for the journey. The motor will be actuated when pressing the buttons for raising or lowering and will stop only under the following circumstances: stoppers' detection (the motor is deactivated at the 0.5 seconds of the arrival of the glass to the end of run stoppers, the soft stop excepted), temperature limit by software, temperature limit of the motor by termo-mechanics.
If during the start of the vehicle the glass of the window is raising, this change of the motor state, from stopped to started, which also originates a change on the feeding tension in the electric circuit of the car, must not producing a trapping cycle. In order to solve that contingency there is estabilished that the electronic circuit detects the feeding tension in the electric circuit of the car. The detection of a sudden change of the feeding tension during the raising cycle of the electric window produces a manoeuvre of stoppage of the glass movement. After a new pressing of the button, the electric window should raise again.
The condition of the vehicle running and vehicle stopped has direct repercussions on the opertion of the trapping cycle. The insensitivity level of the indirect trapping system is determined mainly by its resistance to the inertia moment produced by the rolling conditions when the car is running. The trapping system may be more sensitive as far as the vehicle is not running and, therefore, not subject to the irregularities of the rolling. Therefore, it is determined whether the car is running or stopped in the basis of the measure of the feeding tension. In this sense, it is estabilished that the motor is stopped if a feeding lower than 13 V is detected. It will be estabilished that the motor is running when a feeding higher than 13 V is detected. In this way the trapping sensitivity level is automatically calibrated.
If the motor has not started, the trapping sensitivity is high and the risk of an accident because of the manipulation of the electric window, specially by children, is limited. If the motor is running, the presence of a driver is supposed and the trapping sensitivity will be lower for filtering the inertia moments produced by the unevenness of the rolling.
In front of an eventual defect of functioning of the position detection of the glass, read by the Hall effect sensors, it is kept a safety criterion in the basis of the following circumstances. If the Hall effect sensors don't detect the turning of the motor but it is really moving, the electronics detect that during 0.2 seconds does not exist a lecture of the pulses of the Hall sensors and inactivates the electric window motor. This permits raising or lowering the glass in a sensitive way, by pressing the manual button for raising or lowering. Every rise o descent pulse will permit a glass journey equivalent to 0.2 seconds of the motor turning time. If the Hall effect sensors continue counting pulses in spite of having achieved the journey limit of the electric window and, therefore, the motor continues active creating pressure of the glass against the stopper, the motor current sensors function when detecting a consumption superior to 26 A, disconnecting the motor. It is estabilished a physic limit for the motor of 20 A/s.
The mechanical effects produced because of the mechanical deformation of the transmisssion or elasticity of the system are compensated in grace to the improvements of the anti-pinching system of the invention. Such deformations create always an incremental value by virtue of the fact that it is a plastic deformation, which is always incremental, since, in the reverse case, there should be elastic deformations which don't correspond to the object of the system of the invention. At every cycle of stopper of the glass, the EEPROM memory stores the new value “actualized journey of the glass because of mechanical derivations”. With this calculation it's also actualized the value of the journey of the upper frame and the value of the journey for the soft stop.
As a function of the feeding tension there is estabilished an auto-calibration of the trapping sensitivity. Thus, at a bigger speed of the electric window, the inertial displacement at the stoppage is greater and therefore, the trapping force is also greater. It must be taken into accountthe fact that the state of the rubbers and guides of the glass of the electric window as well as the climatic conditions condition the movement speed of the glass.
The calculus algorithm estabilishes also a trapping sensitivity auto-calibration as a function of the speed of the electric window, in this way there is achieved a lineal trapping sensitivity independently of the electric window speed, either by tension differences in the feeding circuit or by the friction of the transmission. the reaction to the trapping detection is higher when higher is the speed, achieving a similar trapping pressure sensitivity at different speeds.
At the EEPROM memory are stored data such as, for instance, the original reference journey of the electric window, the actual journey of the glass, the reference measure of the upper frame, the reference measure for the soft stop function, the measure for the window of qualification of the trapping (standard between 4 and 200 mm of the upper position), the trapping detection thresholds, the manufacturer, the fabrication lot (value up to 1.000.000), the date (month-year format), the software version, the device version, the EEPROM version, the counter of hudreds, the movements of the electric window performed (value up to 1.000.000), the units counter (trapping cycles performed, value up to 65.000). There may be stored also a register of pinchings, as well as the deceleration produced (for a later report). Thus, the variables stored at said memory are the mechanical effects, the journey and detection threshold, the soft stop of the glass, etc.
According to an aspect of the invention and as has been discussed above, the system is activated whilst the glass is rising and at a distance between 4 and 200 mm of the upper position. If an obstacle is detected, the glass will descend a distance higher or equal to 125 mm. During 10 secondsa, the raising mechanism is inactivated and that of the descent continues active. Said 10 seconds are reinitialized with every movement of rise or descent and stoppage.
The electronic circuit design permits arranging the application in a microcontroller with the possibility of the application programming in the PCB itself once the components are assembled. In this way it is possible programming the application at the same components assembly line, flexibilizing programs actualization, and possibiliting application software actualizations at the final assembly line, retailers, post-sales, etc. as well as an agile access to the software and EEPROM data. In both cases, the EEPROM memory is programmable being possible the configuration of the application varying only the parameters stored at the EEPROM memory.
Th electronic plate of the system is a 4 layers plate and has an easy access dismantling the housing cover without dismantling neither the electric window nor the motor. This allows an easy substitution of the electronic plate.
The invention foresees as well the possible modification of the control software giving to the microprocessor the management capacity of said management. In the other hand, it is also foreseen that the opening of the door may be performed by remote control.
The initialization of the motor is produced performing a cycle of rise and descent for recognizing the door and the windows journey. From that moment, the electronic functions start working. Previously to said initialization, the motor works as a conventional electric motor.
The features and advantages of the improvements of the anti-pinching systems for the automobile that are the object of the present invention will be evident from the detailoed description of a preferred incorporation of same that will be given, from now on, as a non limitative example, with reference to the accompanying drawings, in which:
FIG. 1 is an schematic view of a diagram in which can be appreciated the elements that constitute the anti-pinching system provided with the improvements of the present invention.
FIG. 2 illustrates schematically the global arrangement of the mechanical elements of an electric window provided with an improved anti-pinching system according to the invention.
FIG. 3 is an elevation schematic view of the motor module of the system of the invention.
FIG. 4 is a plant view of the lower portion of the control means of the system of the invention in which has been schematically shown some of the elements constituting the electronics associated with the motor module.
And FIG. 5 is a schematic view of the connector of the motor module seen by the female portion and in which are ilustrated in detail the outer connections of the system.
The elements described in the Figures correspond to ( 1 ) control means, ( 2 ) motor module, ( 2 a ) magneto of the motor shaft, ( 3 ) motor, ( 4 ) MOSFET, ( 5 ) relay, ( 6 ) microprocessor, ( 7 ) consumption signal, ( 8 ) tension signal ( 9 , 10 ) Hall sensores, ( 11 ) glass, ( 12 ) electric window, ( 13 ) operating cable, ( 14 ) drum, ( 15 ) tension regulator, ( 16 ) connector, ( 17 ) body contact, ( 18 ) battery contact, ( 19 ) connection button for operating the driver's glass mounted at the driver's side, ( 20 ) connection button for operating the passenger's glass mounted at the driver's side, ( 21 ) connection centralized opening, ( 22 ) connection automatic mode, ( 23 ) output for the operation of the sliding roof, ( 24 ) connection for the centralized shutting, ( 25 ) output for the shutting of the sliding roof, ( 26 ) connection to the contact key of the motor, ( 27 ) connection for door opening.
The anti-pinching system of the invention as shown in FIG. 1 comprises control means ( 1 ) of the operation of the motor module ( 2 ) which operates the glass ( 11 ) of an automobile, see FIG. 2 . As discussed above, the control means ( 1 ) are activated when same detect any variation in the normal operation of the system.
The improvements of the invention have an effect on the motor module ( 2 ), which is comprised, in the incorporation of the example of FIG. 1, by a motor ( 3 ) of 8 poles. It is a high performance and low heating motor which shows incorporated the magneto in the shaft. With particular reference to the FIG. 3 of the drawings, the arrangement of the magneto of the motor ( 2 a ) in the shaft combined with the geometry of the electronic circuit housing allows the integration of Hall effect sensors ( 9 , 10 ) in the lower face of the electronic circuit. In this way there is achieved a simplification of the assembly process and the reading quality of the magnetic field is very good in the temperature range from −40° C. up to +85° C.
The motor module ( 2 ) receives the signals of the control means ( 1 ), which comprise a field effect transistor of insulated door (MOSFET) represented by ( 4 ) in FIG. 1 and provided for compensating the intensity peaks, the feeding variations and estabilishing a relay ( 5 ) and other elements such as condensers provided in a multi-layer plate, a programmable EEPROM memory, etc. The semi-conductor MOSFET switches in void the power relay which connects the motor, in such a way that the useful life of the relay is advantageously longer. When switching in void the relay, the contacts don't open and close under load and in this way are substantially avoided the problems derived of the electromagnetic emmissions.
The control means ( 1 ) receive the processed signals coming from the programmable microprocessor ( 6 ) which is mounted in the portion more remote of the feeding lines and of the electric motor ( 3 ) for avoiding, in grace to its design, any possible disturbance. Said means incorporate, further, a four layers plate (not illustrated) which shows an easy acces removing the cover of the housing without dismantling neither the electric window nor the motor. This allows an easy substitution of the electonic plate. all the electronics is integrated in the motor assembly of the electric window using a connection by means of the box with a 12 channel connector like the shown in FIG. 5 .
The microprocessor ( 6 ), in turn, receives signals ( 7 , 8 ) on the consumption and tension information as input lectures. The micro-controller used in the incorporation disclosed is provided with a “Flash” memory of 4 kb which allows performing the programming of the application directly on the micro-controller through an SPI series interface or by means of a conventional non-volatile memory programmer. In this way, it's possible to update the application at the assembly and programming process itself. All the instructions are performed in a cycle of the processor's clock, permitting to the designer of the application optimize the consumption on the basis of the data processing speed.
Thus, the control means ( 1 ) operate over the motor module ( 2 ) as a function of the turning speed of the motor ( 2 ) detected by Hall sensors of the type at 0° ( 9 , 10 ), which permit to regulate the motor ( 3 ) speed emmiting a number of pulses for every turn, or as a function of the circulating current intensity, or the system consumption, stopping the motor ( 3 ) and/or reversing the turning sense.
The elements defining the control means ( 1 ) may be appreciated at FIG. 4, in which can be seen the lower portion of the circuit with the Hall sensors ( 9 , 10 ), the microprocessor ( 6 ), a tension regulator ( 15 ), the relay ( 5 ), the MOSFET ( 4 ) and the connector ( 16 ).
With reference to FIG. 5, the connector ( 16 ) includes a plurality of connection elements, which are described in the attached Table.
CONNEC-
TION
TENSION (V)
ELEMENT
DESCRIPTION
0-1
1-9
9-12
(17)
Body
Always 0V
(18)
Battery
Always 12V
(19)
Button of driver's glass at
desc
—
rise
the driver's door
ent
(20)
Button of passenger's glass
desc
—
rise
at the driver's door
ent
(21)
Central opening
—
—
acti
ve
(22)
Automatic
—
—
acti
ve
(23)
Output for the operation of
—
—
acti
the sliding roof
ve
(24)
Contralized shutting
—
—
Acti
(general)
ve
(25)
Shutting the sliding roof
Acti
—
—
(output)
ve
(26)
Motor contact key
—
—
Acti
ve
(27)
Door opening
Acti
—
—
ve
The arrangement of an eight pole motor such as the one of the preferred incorporation here disclosed offers a great precision when allowing a lectures resolution every 0.5 mm of glass vertical displacement. In other words, corresponding every turn of the motor shaft to 4 pulses of the sensor.
The control means ( 1 ) are furnished with a plate that substantially reduces the consumption of the system of the invention, specially every time that the relay ( 5 ) is activated, cutting the current's peaks. Furthermore, said control means ( 1 ) incorporate control means of the temperature of the system starting from the number of turns of the motor ( 3 ) shaft during a given time taking into account the consumption, in such a way that when surpassing an estabilished value, said control of the system temperature only permits the rise of the window. There are also available regulation means of the maximum journey of the window that, when connecting the motor ( 3 ), count the number of pulses read by the Hall sensor ( 9 , 10 ), disconnecting the motor ( 3 ) when a certain estabilished value is overreached without the window arriving to the stopper. Means (not shown) are available for disconnecting the motor ( 3 ) when the window is at a safety distance before the end of the run stopper in its descent, in such a way that the remainder of the journey is obtained because of the window's inertia, allowing a soft stop as a function of the feeding tension, the descent speed of the glass and the system's consumption. In order to that, the motor ( 3 ) is disconnected, first with the MOSFET ( 4 ) and then with the relay ( 5 ), and stops at a safety distance before the lower stoppage.
As above disclosed, the control means ( 1 ) include an programmable EEPROM memory of 128 bytes which may be configurated varying only the stored parameters, said memory stores data such as the original reference journey and the actual journey of the glass, the reference measure of the upper frame, the reference measure for the soft stop function, the movements of the electric window made, a register of pinchings, the deceleration produced, etc.
More precisely, at the EEPROM memory of the incorporation described are stored the parameters of the application. Said parameters may be modified without the need of intervening in the aplication software. The foreseen parameters are the following:
1 —Number of data at the EEPROM memory.
2 —Original reference journey of the glass of the electric window.
3 —Upper position of the trapping window. If the position is lesser, there is not trapping made.
4 —Lower position of the trapping window. If the position is greater, the trapping is not performed.
5 —Position for soft stop when lowering.
6 —Position for soft stop when raising.
7 —Trapping detection value at maximum speed.
8 —Trapping detection value at intermediate speeds.
9 —Trapping detection value at minimum speed.
10 —Pressing time at stopper (in units of 0.131072 s).
11 —Manufacturer.
12 —Manufacturing lot (value up to 1.0000.000)
13 —Date (MonthMonth-YearYear format).
14 —Software version.
15 —Hardware version.
16 —EEPROM version.
17 —Hundreds counter. Electric window movements (up to 1.000.000).
18 —Units counter. Trapping cycles performed (value up to 65.000).
With reference to FIG. 2, the protection against the overcharging of the motor of the system for raising a window ( 11 ) is performed by software, which accumulates the time of functioning of the electric window and, when exceeding the limit estabilished value only permits the raising up to the upper stopper. In normal operating condictions should be performed 20 complete cycles of rise and descent of the glass ( 11 ) without disconnection of the system.
If the glass ( 11 ) arrives to the upper stopper of the journey or is stopped by the eventual blocking of an object, the motor ( 3 ) stops in a very short time, for instance in 0.2 s, in grace to the fact that this motor ( 3 ) is of eight poles.
If the vehicle is starting during the rise of the glass ( 11 ) the anti-pinching system of the invention detects and filters the fall of tension provoked by the starting of the motor avoiding that a falsse pinching is produced, since the fall in tension provokes a variation on the speed that can be detected by the Hall sensors ( 9 , 10 ), in such a way that, before producing a false pinching, will provoke the detention of the motor ( 3 ).
In this sense, the anti-piinching system takes into account whether the vehicle is stopped or running as per the feeding tension. if the feeding tension is lower than 13 V it indicates that the vehicle has not started, because of which the sensitivity may be higher. Instead, if the feeding tension is higher that 13 V, it indicates that the vehicle has been started, by which the sensitivity is lower.
The motor ( 3 ) is able to perform a reverseal in the turning sense in a very short time when the glass ( 11 ) is lowering. Thus, every time that the glass ( 11 ) stops during its descent journey, there is produced a rise pulse. The maximum value of this pulse is of 0.53 mm and produces a blocking on the motor ( 3 ) gears like if it was a rise, in such a way that the detention of the motor lacks inertia and the glass does not “sink” so much when leaning on.
When the motor ( 3 ) is connected, the number of pulses read by the Hall sensor ( 9 , 10 ) is counted. If it surpasses an amount without having reached the stopper (maximum journey 100 mm), the motor ( 3 ) is diconnected. If there exists an operation defect in the detection of the position of the glass ( 11 ), which is read by the Hall effect sensors ( 9 , 10 ), a security criteria is kept on the basis of several circumstances. If the Hall effect sensors ( 9 , 10 ) don't detect the turning of the motor ( 3 ), but it is really moving, the control means ( 1 ) tells that during 0.2 s there is not pulses reading of said Hall sensors ( 9 , 10 ) and inactives the movement of the motor ( 3 ) of the electric window ( 12 ). This permits raising or lowering the glass ( 11 ) by the operating cable ( 13 ) and the drum ( 14 ) in a sensitive way pulsating the rise or descent button, in such a way that every rise or descent pushing will permit a journey of the glass ( 11 ) equivalent to 0.2 s of rotation time of the motor ( 3 ). If the Hall effect sensors ( 9 , 10 ) continue counting pulses even if the journey of the glass ( 11 ) limit has been reached and, therefore, the motor ( 3 ) continues functioning in such a way that the glass raises against the stopper, the control means ( 1 ) detects a consumption over 25 A and disconnects the motor. The physical limit estabilished for the motor is 20 A/s.
Another remarkable feature is the fact that the system of the invention permits solving eventual incompatibilities between the orders of the buttons. Thus, at an order of raising and another of lowering, the electronics gives priority to the descent sequence taking into account that if the glass is raising and the descent button is pulsed, the glass descents. In the other hand, if the glass is lowering and the rise button is pulsed, the glass will stop. Nevertheless, it's also foreseen that the glass stops when starting or stopping the car motor with the contact key.
Even if a preferred incorporation of one of the improvements on the anti-pinching systems for the automobile has been described, the inventive scope of the present invention foresees that incorporation of other improvements, especially those derived of the programmability of all the parameters intervening in the system object of the invention.
Enough described in what the present invention consists corresponding with the attached drawings, it's understood that in same may be introduced any detail modification deemed convenient, provided that there are not altered the essential characteristics of the invention summarized in the following claims. | The system includes a motor ( 3 ) of at least eight poles, control means ( 1 ) acting on the motor ( 3 ) as a function of its turning speed or the current intensity, stopping its operation and/or reversing its turning sense, including Hall sensors ( 9, 10 ), a MOSFET ( 4 ) transistor, a relay ( 5 ), a programmable microprocessor ( 6 ), condensers in a multilayer plate, an EEPROM memory, control means for the temperature of the system, regulation means of the maximum journey of the window ( 11 ) and disconnecting means of the motor ( 3 ) when the glass ( 11 ) is at a safety distance before the lower or upper end of the run stopper, reaching the final journey by the inertia of the glass ( 11 ) or by mechanical drawing of the transmission, respectively. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. provisional application No. 60/239,388, filed Oct. 11, 2000, the entire contents of which are incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] Optically-read digital storage and play-back media, such as laser disks, compact audio disks, digital video disks, CD-ROMS (read only memory), and others, hereinafter cumulatively referred to as compact disks (CDs), are essentially various layers of plastic covering which protect a reflective foil coating. The foil coating may be configured to store a wide variety and quantity of digital information which may be optically read through the use of laser light.
[0005] Protecting the information containing foil is one or more layers of protective plastic, such as polycarbonate, through which the laser is passed in order to read the information stored on the foil.
[0006] As is well known to anyone who has used CDs, the play surface of the protective plastic layer is relatively easy to scratch or otherwise mar through routine handling and use. Quite often a scratch or other surface impairment may prevent proper laser transmission and/or reflection thereby resulting in the inability to read the CD or which ay cause improper retrieval of information from the CD.
[0007] The present invention is directed to a method and apparatus for rendering a D which has been rendered unreadable or only partially readable due to the presence of one or more surface imperfections on the play surface, readable by repairing and/or polishing the play surface of the CD. More specifically, the present invention is directed to a method of repairing the play surface of a CD wherein a specialized CD mounting attachment is used to removably secure the CD to an electric rotary drill or similar device, which in turn rotates the CD at high speed, whereupon a polishing and/or filling agent may be applied to the CD surface with a soft material.
[0008] 2. Description of the Related Art
[0009] Numerous apparatus and methods exist for repairing damaged play surfaces of CDs. For Example: U.S. Pat. No. 5,938,510; U.S. Pat. No. 5,733,179; U.S. Pat. No. 5,593,343 and U.S. Pat. No. 4,179,852 all disclose various apparatus and methods for cleaning and/or reconditioning CDs. All of the aforementioned references share a common drawback in that they all describe fairly complex stand alone devices which the average consumer would be unlikely to purchase or have access to. The devices described each require that a CD be inserted into the device whereupon the respective devices modify the play surface of the CD in accordance with their various disclosures.
[0010] Another prior art method is described in U.S. Pat. No. 6,099,388. The '388 reference describes a method for repairing a CD which utilizes one or a series of progressively abrasive means to selectively abrade the area of the CD surface around the cite of a scratch. A drawback to such progressive abrasion is that it may be labor intensive in that abrading only a portion of the CD may require fine manipulation of the CD and the abrasion means.
[0011] The present invention overcomes the shortcomings described above by providing a inexpensive and readily obtainable system for repairing CD's which abrades and polishes the entire CD play surface, which may also fills in scratches on the play surface thereby restoring the readability of the CD.
[0012] The entire content of all patents listed within the present patent application re incorporated in their entireties herein by reference.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention may be directed to numerous embodiments. In at least one embodiment the invention provides for a method of repairing and/or polishing a CD by removably engaging a CD, which has its play surface exposed, onto a specialized adhesive mounting surface which is in turn engaged to an electric rotary drill. The drill is used to rotate or spin the CD at relatively high rotational speed. As the CD is spun, an abrasive liquid and/or polish is applied to the play surface by application of a cloth or other application means. The cloth has the abrasive liquid and/or polish thereon. The cloth is pressed against the play surface as the CD rotates, to ensure uniform application of the abrasive and/or polish to the play surface.
[0014] The high speed rotation of the CD and the contact of the cloth thereagainst provide a heating and buffing action to the CD surface which helps to provide the desired uniform abrasion and filling in of any scratches on the play surface.
[0015] In at least one alternative embodiment of the invention an abrasive paper or other material may be applied to the CD play face prior to the application of the liquid abrasive.
[0016] In at least one embodiment of the invention the abrasive paper has a grit of approximately 400 or higher.
[0017] In at least one embodiment of the invention the abrasive liquid and polish are combined together.
[0018] In at least one embodiment of the invention multiple abrasive materials are subsequently applied to the play surface. For example a first material may be applied to the rotating play surface, wherein the first abrasive material is approximately 400 grit or more. Subsequent applications of abrasive materials having a finer grain, for example 1200 grit.
[0019] In at least one embodiment of the invention, a suitable polish may be applied to the CD play surface subsequent to the application of the abrasive material.
[0020] In at least one embodiment of the invention a wax is applied to the CD play surface.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0021] A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
[0022] [0022]FIG. 1 is a perspective partially exploded view of an embodiment of the components of the inventive system; and
[0023] [0023]FIG. 2 is a perspective view of a compact disk shown after treatment with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.
[0025] As may be seen in FIG. 1, the present invention may have a number of components which when combined provide for the unique system and method of repairing scratched CDs as discussed above. FIG. 1 shows an embodiment of the CD repairing system, indicated generally at reference numeral 10 , which includes as its primary components a drill 12 , an attachment tool 14 , an application cloth 18 and an abrasive/polishing liquid 20 . When these and other optional components are combined and used in the manner described herein the system 10 provides a consumer with a unique, low cost alternative to existing CD repair methods and devices.
[0026] The drill 12 may be a household or professional grade, single speed or variable speed electric drill. Other devices may be substituted for the drill such as a DREMEL™ or other device capable of providing high speed rotation.
[0027] The attachment tool 14 , is a substantially disk shaped attachment which may be engaged to the drill to provide a surface upon which a CD 22 may be removably engaged thereto. An example of the attachment tool 14 is product referred to as a universal back-up pad available from the Ace Hardware Corporation. The attachment tool may be provided with a number of shapes and sizes. Preferably the tool 14 has substantially the same or somewhat greater diameter than the diameter of the CD 22 . In the embodiment shown, the attachment tool 14 is engaged to the drill by a bit 24 having a substantially hollow threaded inner portion 26 . A threaded screw 28 is passed through a first support washer 30 , through a central opening 31 in the tool 14 , through a second support washer 32 and finally threaded and engaged into portion 26 of the bit 24 . Numerous alternatives of the tool 14 exist. Such alternatives may include single piece disk and bit assemblies or other types of assemblies. Such assemblies may be readily substituted for the attachment tool presently shown.
[0028] In at least one embodiment of the invention, the attachment tool 14 includes a mounting surface 34 which may be characterized as having adhesive qualities, or which may have an adhesive applied thereto. The adhesive or adhesive quality of the mounting surface 34 must be such that when a CD 22 is adhesively engaged to the mounting surface 34 it may be removed from the mounting surface 34 without causing damage to the CD 22 which is removably engaged thereto. Preferably, no adhesive residue will remain on a CD subsequently removed from the mounting surface 34 .
[0029] Alternatively, the mounting surface 34 does not include an adhesive. In such an embodiment an alternative means of removably mounting the CD 22 to the mounting surface 34 may be provided by positioning the CD 22 between the first support washer 30 and the mounting surface 34 . In such an embodiment the screw 28 is initially passed through the washer 30 then through the open center 36 of the CD 22 , then through the remaining portions of the tool 14 and associated components as previously described.
[0030] Once the CD 22 is engaged to the mounting surface 34 , the drill 12 may be “turned on” so that the CD 22 is rotated at a high speed. The drill 12 should rotate the CD 22 at a rate between approximately 800 and 2500 rpm. However, it should be noted that other speeds may be used, though repair results to the CD may vary.
[0031] Once the CD 22 is being rotated at the desired speed, an application means such as a cloth 18 may be applied to the rotating play face 42 of the CD 22 . If the play face 42 has fairly deep scratches, such as are indicated by reference numeral 44 , an abrasive substance 20 is applied to the play face. If the scratch(es) 44 are particularly deep it may be desirable to first apply sandpaper 50 of 400 grit or more to the play face 42 in order to reduce the thickness of the play face 42 so that the scratch may be more readily abraded by an abrasive substance 20 .
[0032] Preferably the abrasive substance 20 is a commercially available liquid abrasive/polish suitable for use on plastics. An example of such a liquid is available form the 3M Corporation, sold under the name 3M One Step Cleaner Wax. Other substances or combinations of substances which may be used as the abrasive substance 20 include, waxes, polishes and cleaners. It should also be noted that multiple applications of one or more substance may be made to the play face 42 . For example, where scratches are particularly deep an abrasive compound such as 3M Heavy Cut Polishing Compound may be applied to the play surface 42 , followed by one or more additional abrasives, polishes or cleaners.
[0033] As indicated, an abrasive, polish, cleaner and/or other substance as well as combinations and subsequent applications are represented by substance 20 , which in all cases is applied to the play surface of the rotating CD 22 with an application means such as cloth 18 . The cloth 18 is preferably composed of 100 percent cotton, though other materials may be used. The user, indicated generally at reference numeral 48 , presses the cloth 18 and associated substance 20 against the rotating play face 42 . Preferably the user 48 applies a uniform pressure to the CD 22 . The pressure supplied by the user 48 provides a frictional interaction between the cloth 18 and the play surface 42 which may cause the play surface to heat up. The heating of the play surface 42 , helps to more readily abrade material off of the play surface 42 , especially those portions of the surface which comprise the scratches 44 .
[0034] In addition to abrading material of the play face 42 in order to reduce scratch 44 depth, where the substance 20 includes or is a polish, the polish will fill in the remaining depth of the scratch to provide a CD 22 with a play surface 42 which is substantially unimpaired such as may be seen in FIG. 2.
[0035] In addition to being directed to the specific combinations of features claimed below, the invention is also directed to embodiments having other combinations of the dependent features claimed below and other combinations of the features described above.
[0036] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
[0037] Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below. | A method and system for repairing a play surface of a compact disc. The system comprises a rotary drill, an attachment for removably engaging a compact disk thereto such that the play surface is exposed and at least one abrasive substance. The compact disc is rotated at a predetermined rotational rate whereupon the at least one abrasive substance is uniformly applied to the play surface. Additionally at least one polish may be uniformly applied to the play surface while the compact disc is rotating at the predetermined rotational rate. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 12/368,214, filed on Feb. 9, 2009, entitled “Safe And Arm Mechanisms And Methods For Explosive Devices,” now allowed, which claims benefit under 35 U.S.C. §119 of U.S. Provisional Patent Application No. 61/027,369, filed on Feb. 8, 2008, entitled “Miniature Safe And Arm Device,” both of which are incorporated herein in their entirety by reference.
TECHNICAL FIELD
[0002] The present disclosure relates generally to safe and arm mechanisms and methods for explosive devices. The present disclosure relates particularly to self-contained, all mechanical safe and arm mechanisms and methods for explosive devices.
BACKGROUND
[0003] Government safety regulations govern the specifications of military explosive devices. Among other things, current safety regulations for military explosive devices include at least the following two requirements. First, all explosive devices must be safe from inadvertent functioning in non-operational and operational environments. Second, explosive devices must be capable of self destructing either commanded or un-commanded to reduce the hazard of unexploded ordnance (UXO). Details of these requirements are contained in specifications MIL-STD-1316E, STANAG 4187 and STANAG 4404. Conventionally, certain types of explosive devices may include safe and armed (S&A) mechanisms or other types of fuzes to comply with these requirements. S&A mechanisms may include relatively simple safety mechanisms or sophisticated, programmable, target discriminating safety mechanisms.
[0004] A conventional S&A mechanism has much of its functionality controlled by sophisticated micro-electronics. These microelectronic components may detect environmental factors that affect the S&A mechanism and may select the components of the explosive device that are activated. Such conventional detecting and activation mechanisms have been used, for example, to activate explosives only upon impact of a particular type or level.
[0005] Other conventional S&A mechanisms are relatively large and are controlled by commensurately large mechanical, electro-mechanical, or electronic mechanisms. For example, such conventional S&A mechanisms may be electrically connected via a cable to remotely located controllers, sensors, power sources, and other electrical components. These S&A mechanisms have been used in explosives such as bombs, artillery shells, mines, missile warheads, and other devices that may have less stringent size and/or weight limitations.
[0006] The relatively large size and complex interconnections of these conventional S&A mechanisms tends to make them cumbersome and expensive. Explosive devices that have more stringent size and/or weight limitations cannot use such conventional S&A mechanisms, but instead require smaller, less complex and less expensive S&A mechanisms. For example, a countermine weapon for neutralizing one or more mines in a target area includes many smaller projectiles that each contains an explosive warhead. Such projectiles may be smaller even than conventional S&A mechanisms but are still required to individually comply with the safety requirements described above. Firing these countermine weapons deploys the projectiles, which spread out to cover the target area. Accordingly, it is not practical for individual projectiles to be connected with cables to a central electrical controller. Moreover, the S&A mechanisms for each projectile need to react differently in response to the type of impact, e.g., with a mine, with sand, with water, etc.
BRIEF SUMMARY OF THE INVENTION
[0007] Aspects of the present invention are generally directed toward a mechanism configured to transition an explosive device from a SAFE arrangement to an ARMED arrangement. One aspect of embodiments is directed toward a mechanism including a first firing pin, a delay primer, a second firing pin, a rotor, and a detonator. The first firing pin is configured to move along a longitudinal axis in response to a first deceleration force. The delay primer is configured to be operated by the first firing pin moving along the longitudinal axis. The delay primer is also configured to generate a pressure force at an end of a delay period. The second firing pin is configured to move along the longitudinal axis in response to at least one of the pressure force at the end of the delay period and a second deceleration force that is greater than the first deceleration force. The rotor is configured to move between first and second radial positions with respect to the longitudinal axis. The first radial position corresponds to the SAFE arrangement, and the second radial position corresponds to the ARMED arrangement. The second radial position is radially outward from the first radial position. The detonator is supported by the rotor and is configured to be operated by the second firing pin moving along the longitudinal axis when the rotor is in the second position. The detonator is also configured to be inoperable when the rotor is in the first position.
[0008] Other aspects of the present invention are generally directed toward an explosive device. One aspect of embodiments is directed toward an explosive device including a mechanism configured to transition from a SAFE arrangement of the explosive device to an ARMED arrangement of the explosive device and a fin configured to rotate the mechanism. The mechanism includes a first firing pin, a delay primer, a second firing pin, a rotor, and a detonator. The first firing pin is configured to move along a longitudinal axis in response to a first deceleration force. The delay primer is configured to be operated by the first firing pin moving along the longitudinal axis. The delay primer is also configured to generate a pressure force at an end of a delay period. The second firing pin is configured to move along the longitudinal axis in response to at least one of the pressure force at the end of the delay period and a second deceleration force that is greater than the first deceleration force. The rotor is configured to move between first and second radial positions with respect to the longitudinal axis. The first radial position corresponds to the SAFE arrangement, and the second radial position corresponds to the ARMED arrangement. The second radial position is radially outward from the first radial position. The detonator is supported by the rotor and is configured to be operated by the second firing pin moving along the longitudinal axis when the rotor is in the second position. The detonator is also configured to be inoperable when the rotor is in the first position. The fin is configured to rotate the mechanism on the longitudinal axis in response to an air stream flowing parallel to the longitudinal axis.
[0009] Yet other aspects of the present invention are generally directed toward a method of changing from a SAFE mode of an explosive device to an ARMED mode. One aspect of embodiments is directed toward a method including exposing an elongated mechanism to an air stream flowing approximately parallel to a longitudinal axis of the mechanism, imparting rotation to the mechanism on the longitudinal axis in response to the air stream, and transitioning the mechanism from a SAFE arrangement to an ARMED arrangement in response to exceeding a predetermined velocity of the air stream flow and exceeding a predetermined angular velocity of the mechanism rotation.
[0010] Additionally, a method is described for operating a safety device for an explosive apparatus. A first action is performed upon detecting an impact between the explosive apparatus and a “hard target”. A second action is performed upon detecting an impact between the explosive apparatus and a “soft target”. The first action may include detonating an explosive and the second action may include executing a self-destruct operation after a predetermined time interval.
[0011] Further, a SAFE & ARM (S&A) mechanism is described that includes an elongated casing or envelope having a first end and a second end. A high-G firing pin is arranged relatively near to the first end and a low-G firing pin is arranged relatively near to the second end, and a detonator is arranged between the high-G firing pin and the first end. When a G-force within a first range of magnitudes is applied to the casing along its longitudinal axis, the low-G firing pin is displaced to strike a portion of the high-G firing pin, and if a G-force within a second range of magnitudes is applied to the casing along its longitudinal axis, the high-G firing pin is displaced to strike the detonator. The device may become active in response to a centrifugal force generated by spinning the casing on its longitudinal axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a partial cross-section view showing an explosive device including an S&A mechanism according to the present disclosure.
[0013] FIG. 2 is a partial cross-section view showing the S&A mechanism of FIG. 1 in a SAFE arrangement.
[0014] FIG. 3 is a cross-section detail view showing the S&A mechanism of FIG. 1 in a SAFE arrangement.
[0015] FIG. 4 is a cross-section detail view showing the S&A mechanism of FIG. 1 in an ARMED arrangement.
[0016] FIG. 5 is a partial cross-section view showing the S&A mechanism of FIG. 1 during a soft target impact.
[0017] FIG. 6 is a partial cross-section view showing the S&A mechanism of FIG. 1 during a hard target impact.
[0018] FIG. 7 is a cross-section detail view showing another S&A mechanism according to the present disclosure in a SAFE arrangement.
[0019] FIG. 8 is a cross-section detail view showing the S&A mechanism of FIG. 7 in an ARMED arrangement.
[0020] FIG. 9 is an exploded view perspective view showing yet another S&A mechanism according to the present disclosure.
[0021] FIG. 10 is a cross-section detail view showing the S&A mechanism of FIG. 9 in an ARMED arrangement.
[0022] FIG. 11 is a cross-section detail view showing the S&A mechanism of FIG. 9 in a SAFE arrangement.
[0023] FIG. 12 is a cross-section detail view showing the S&A mechanism of FIG. 9 in an ARMED arrangement.
[0024] FIG. 13 is a graphical illustration explaining different types of impacts.
DETAILED DESCRIPTION
A. Overview
[0025] Embodiments according to the present disclosure include various explosive devices and related safety mechanism such as a fuze or an S&A mechanism. Other embodiments according to the present disclosure further include various methods for operating the explosive devices and S&A mechanisms. Certain embodiments are designed to comply with government safety regulations such as MIL-STD-1316.
[0026] Embodiments according to the present disclosure include S&A mechanisms suitable for miniature projectile munitions where conventional S&A mechanisms are not readily implemented. For instance, certain embodiments include an S&A mechanism that is contained within has a small package, e.g., having a diameter of less than 0.75 inches and an axial length less than 2.50 inches, or a diameter of approximately 0.45 inch and an axial length of approximately 1.50 inches. Additionally, certain other embodiments of the S&A mechanisms are configured to differentiate between different types of impacts and/or to self destruct after a pre-determined time delay.
[0027] Embodiments according to the present disclosure include completely self-contained S&A mechanisms. Certain embodiments of self-contained S&A mechanisms include a completely mechanical mechanism that neither includes an electric power source nor is connected to an external electric power source.
[0028] Embodiments according to the present disclosure include S&A mechanisms that do not require any maintenance, programming, or adjustments. Certain embodiments of the S&A mechanisms use proven and DOD approved explosive components and are designed for high volume assembly. Additionally, certain other embodiments of the S&A mechanisms can be functionally tested in isolation or together with a final assembly. Some of these examples are described below and/or illustrated in the attached Figures.
B. Embodiments Of Safe And Arm Apparatuses And Methods For Using Such Apparatuses
[0029] FIG. 1 is a partial cross-section view showing an explosive device 10 including an S&A mechanism 100 according to the present disclosure. The explosive device 10 shown in FIG. 1 can be configured as a miniature projectile that extends along a longitudinal axis A less than 10 inches and has a diameter of less than 0.75 inches, and a longitudinal length of approximately 6.5 inches and a diameter of approximately 0.44 inches. As also shown in FIG. 1 , the warhead of the explosive device 10 can include an explosive pellet 12 contained in a nose section 14 that is located along the longitudinal axis A forward of the S&A mechanism 100 . Certain embodiments include hermetically sealing the nose section 14 to the S&A mechanism 100 , e.g., by welding, threaded connection, interference fitting, or another suitable coupling. The explosive device 10 can also include a tail assembly 16 located along the longitudinal axis A aft of the S&A mechanism 100 . As is well understood, the tail assembly 16 includes a plurality of fins 18 that are configured to induce axial spin by the S&A mechanism 100 in response to longitudinal airflow along the S&A mechanism 100 . For example, relative air speed of approximately 900 feet/second can induce spin of at least approximately 1,200 revolutions/minute (rpm).
[0030] The S&A mechanism 100 can provide a mid-body, structural component of the explosive device 10 . Direct coupling between the S&A mechanism 100 , the nose section 14 , and the tail assembly 16 can at least mitigate or eliminate impact attenuation, e.g., the transmission of deceleration forces to the S&A mechanism 100 through the explosive pellet 12 . The S&A mechanism 100 can have approximately the same diameter as the explosive device 10 and extend longitudinally in a range of 1.5 to 2.0 inches, and approximately 1.8 inches. The mass of the S&A mechanism 100 can be less than 45 grams, and approximately 30 grams.
[0031] FIG. 2 is a partial cross-section view showing the S&A mechanism 100 in a SAFE arrangement. As shown in FIG. 2 , the S&A mechanism 100 includes a lead holder 110 , a rotor 130 , a high-G firing pin 150 , a delay primer holder 160 , a low-G firing pin 170 , and an aft housing 180 . These features can be enclosed by a sleeve 102 and an aft sleeve 104 . The sleeve 102 extends between the lead holder 110 and the delay primer holder 160 . Certain embodiments of the S&A mechanism 100 can include hermetically sealing the sleeve 102 to the lead holder 110 and to the delay primer holder 160 , e.g., by welding. The aft sleeve 104 extends between the delay primer holder 160 and the aft housing 180 . Certain embodiments of the S&A mechanism 100 can include hermetically sealing the aft sleeve 104 to the delay primer holder 160 and to the aft housing 180 , e.g., by welding. According to other embodiments, the sleeve 102 and the aft sleeve 104 can be fixed to the lead holder 110 , the delay primer holder 160 , and the aft housing 180 by interference fits or other suitable couplings.
[0032] The lead holder 110 can include a plurality of passages. A first passage 112 extends longitudinally between a forward lead cavity 114 and an aft high-G aperture 116 configured to receive the high-G firing pin 150 . The forward lead cavity 114 houses a lead configured to igniting the explosive pellet 12 . Intersecting the first passage 112 is a second passage 118 that extends transversely between interior surfaces of the sleeve 102 and is configured to guide side-to-side sliding of the rotor 130 . A third passage 120 intersects the second passage 118 and defines at least one pocket 122 (pockets 122 a and 122 b are shown in FIG. 2 ) in the lead holder 110 . The third passage 120 can also extend transversely between interior surfaces of the sleeve 102 or each pocket 122 can include a bottom surface (not shown) defined by the lead holder 110 .
[0033] FIG. 3 is a partial cross-section view showing the rotor 130 in a SAFE arrangement of the S&A mechanism 100 . A first revolution per minute (RPM) lock is associated with the rotor 130 and includes an individual weight 132 (weights 132 a and 132 b are shown in FIG. 3 ) disposed in each pocket 122 of the lead holder 110 . Resilient members 134 (e.g., individual compression springs 134 a and 134 b are shown in FIG. 3 ) bias the weights 132 radially inward. As shown in FIGS. 2 and 3 , individual resilient members 134 extend between the interior surface of the sleeve 102 and each weight 132 . In the SAFE arrangement of the S&A mechanism 100 , each weight 132 includes a projection 136 that engages with a recess 138 on the rotor 130 . The rotor 130 supports a detonator 140 at a position that is offset with respect to the longitudinal axis A and therefore also offset with respect to the high-G aperture 116 of the lead holder 110 . Accordingly, the high-G firing pin 150 does not pass through the high-G aperture 116 and does not ignite the detonator 140 in the SAFE arrangement of the S&A mechanism 100 .
[0034] Referring again to FIG. 2 , the high-G firing pin 150 is coupled to a first mass 152 that is configured to slide axially within the sleeve 102 . Movement of the first mass 152 is restrained in the SAFE arrangement of the S&A mechanism 100 by at least one high-G shear pin 154 (individual high-G shear pins 154 a and 154 b are shown in FIG. 2 ) that couples the first mass 152 and the delay primer holder 160 . Insofar as the delay primer holder 160 is fixed with respect to the sleeve 102 and the aft sleeve 104 , the high-G shear pin 154 restrains movement of the first mass 152 in the SAFE arrangement of the S&A mechanism 100 . Accordingly, the high-G firing pin 150 does not pass through the high-G aperture 116 and does not ignite the detonator 140 in the SAFE arrangement of the S&A mechanism 100 . The high-G shear pin 154 holds the high-G firing pin 150 such that the explosive device 10 explodes only upon a suitable high-G impact. The high-G shear pin 154 is sized to shear at a predetermined level of deceleration, measured in gravitational units (G; one G of deceleration is approximately −9.8 meters/second 2 ).
[0035] As shown in FIG. 2 , the delay primer holder 160 includes a cavity 162 that is configured to hold a delay primer 164 . The delay primer 164 is configured to delay movement of the high-G firing pin 150 to ignite the detonator 140 . Certain embodiments according to the present disclosure include a delay primer 164 configured to provide a delay period ranging from approximately zero milliseconds to approximately five minutes, and approximately 50-150 milliseconds. Thus, the delay period can allow the explosive device 10 time to complete traveling into a target, e.g., approximately 25 milliseconds or less, before exploding. Longer delay periods can require a physically larger delay primer 164 , which could also elongate the explosive device 10 . Other embodiments can provide other suitable delay periods in response to the type of impact by the explosive device 10 . Aft of the cavity 162 is a low-G aperture 166 configured to receive the low-G firing pin 170 .
[0036] The low-G firing pin 170 is coupled to a second mass 172 that is configured to slide axially within the aft sleeve 104 . Movement of the second mass 172 is restrained in the SAFE arrangement of the S&A mechanism 100 by at least one low-G shear pin 174 that couples the second mass 172 and the aft housing 180 . Insofar as the aft housing 180 is fixed with respect to the aft sleeve 104 , the low-G shear pin 174 restrains movement of the second mass 172 in the SAFE arrangement of the S&A mechanism 100 . Accordingly, the low-G firing pin 170 does not pass through the low-G aperture 166 and does not ignite the delay primer 164 in the SAFE arrangement of the S&A mechanism 100 . The low-G shear pin 174 is sized to shear at a predetermined level of deceleration that is less than that required to shear the high-G shear pin 154 .
[0037] FIG. 4 is a cross-section detail view showing the S&A mechanism 100 in an ARMED arrangement. The S&A mechanism 100 is armed in response to launching the explosive device 10 . Specifically, longitudinal air flow acting on the fins 18 causes the explosive device 10 to spin on the longitudinal axis A. A predetermined rate of axial spin by the explosive device 10 causes the weights 132 to be displaced radially outward with respect to the longitudinal axis A. Accordingly, the projections 136 disengage from the recesses 138 on the rotor 130 . The axial spin also causes the rotor 130 to slide within the second passage 118 in the ARMED arrangement of the S&A mechanism 100 . Certain embodiments according to the present disclosure include the rotor 130 having an asymmetrically located center of gravity configured such that the rotor 130 moves the detonator 140 into alignment with the longitudinal axis A. Accordingly, the detonator 140 is also moved into alignment with the high-G aperture 116 of the lead holder 110 in the ARMED arrangement of the S&A mechanism 100 .
[0038] The RPM lock associated with the rotor 130 of the S&A mechanism 100 is configured to prevent arming in non-operational environments. As shown in FIGS. 2-4 , the pockets 122 a and 122 b are positioned approximately 180 degrees apart around the longitudinal axis A. Thus, if the forces acting on the explosive device 10 are such that one of the weights 132 , e.g., weight 132 a, is tending to release then the opposite weight 132 b is locking harder. Such forces could arise if, for example, the longitudinal axis A of the explosive device 10 is tumbling. The RPM lock is released by spinning of the explosive device 10 on the longitudinal axis A. After un-locking, the rotor 130 translates from the SAFE to the ARMED position such that the detonator 140 is in alignment with the high-G firing pin 150 .
[0039] The explosive device 10 in the ARMED arrangement of the S&A mechanism 100 can function in two modes depending on target impact. The first mode is triggered when the explosive device 10 impacts in a soft media, e.g., misses a target. In this mode, the explosive device 10 self destructs within approximately 150 ms following impact. The second mode is triggered when the explosive device 10 impacts a hard target. In the second mode, the explosive device 10 explodes immediately upon impact. In particular, the explosive device 10 is configured to explode in response to one of high-G firing pin 150 and/or the low-G firing pin 170 moving axially along the longitudinal axis A as a result of an impact by the explosive device 10 .
[0040] In both modes, the delay primer 164 is configured such that the S&A mechanism 100 will self-destruct after the predetermined delay period. The S&A mechanism is completely self-contained and can be tailored to different RPM spin rates and target characteristics, e.g., ability of the target to decelerate the explosive device 10 . In addition the time delay to self-destruct operation can be selected based on the application.
[0041] FIG. 5 is a partial cross-section view showing the occurrence of the S&A mechanism 100 impacting with a hard target. Deceleration of at least approximately 20,000 G can occur when the explosive device 10 impacts a hard target, e.g., a mine. This deceleration force acting on the first mass 152 shears the high-G shear pin 154 . Accordingly, the high-G firing pin 150 passes through the high-G aperture 116 and ignites the detonator 140 in the ARMED arrangement of the S&A mechanism 100 . This same deceleration force also acts on the second mass 172 , shearing the low-G shear pin 174 . Accordingly, the low-G firing pin 170 passes through the low-G aperture 166 and ignites the delay primer 164 in the ARMED arrangement of the S&A mechanism 100 .
[0042] FIG. 6 is a partial cross-section view showing the occurrence of the S&A mechanism 100 impacting with a soft target. Deceleration in an approximate range of 500 G to 20,000 G, and at least approximately 1,130 G, can occur when the explosive device 10 impacts a soft target, e.g., sand or water. This deceleration force acts on the second mass 172 , shearing the low-G shear pin 174 . This deceleration force is, however, insufficient to shear the high-G shear pin 154 . The low-G firing pin 170 passes through the low-G aperture 166 and ignites the delay primer 164 in the ARMED arrangement of the S&A mechanism 100 . At the end of the delay period, e.g., approximately 150 milliseconds, the burning delay primer 164 rapidly produces a pressure in the cavity 162 that is sufficient to shear the high-G shear pin 154 and to displace the high-G shear pin 154 and the first mass 152 along the longitudinal axis A. Accordingly, at the end of the delay period, the high-G firing pin 150 passes through the high-G aperture 116 and ignites the detonator 140 in the ARMED arrangement of the S&A mechanism 100 .
[0043] FIGS. 7 and 8 are cross-section detail views showing the S&A mechanism 100 additionally including a rotor arm lock 142 for the rotor 130 in the SAFE and ARMED arrangements, respectively. A fourth passage 124 extends through the rotor 130 approximately parallel to the longitudinal axis A. Positioned in the fourth passage 124 are a pair of lock pins 144 biased apart by another resilient element 146 , e.g., a compression spring. In the SAFE arrangement shown in FIG. 7 , outboard ends of the lock pins 144 are configured to slide in grooves 126 on interior surfaces of the second passage 118 through the lead holder 110 . The lock pins 144 sliding in the grooves 126 can further guide the movement of the rotor 130 in the second passage 118 . In the ARMED arrangement shown in FIG. 8 , the resilient element 146 biases the lock pins 144 into counter bores 128 located at radially outward ends of the grooves 126 . Accordingly, the lock pins 144 extend partially into the counter bores 128 and partially into the fourth passage 124 to lock the rotor in the ARMED arrangement and thereby prevent the rotor 130 from returning to the SAFE arrangement of the S&A mechanism 100 . Generally analogous to the function of the weights 132 , if a force acts on the explosive device 10 such that one of the lock pins 144 in the ARMED arrangement tends to release the rotor arm lock 142 , then the other lock pin 144 is locked harder into its corresponding counter bore 128 .
[0044] FIG. 9 is an exploded view perspective view showing another S&A mechanism 200 according to the present disclosure. The S&A mechanism 200 differs from the S&A mechanism 100 shown in FIG. 2 in at least two ways, otherwise generally analogous features are indicated with the same reference numbers. First, referring also to FIG. 10 , the S&A mechanism 200 includes a second RPM lock that is associated with the low-G firing pin 170 . Accordingly, the second RPM lock can include at least one weight 176 and at least one corresponding spring 178 that are disposed in corresponding pockets 182 of the aft housing 180 . The first and second RPM locks can be actuated by the same or different spin rates of the explosive device 10 on the longitudinal axis A. Otherwise, the function of the second RPM lock can be generally analogous to that of the first RPM lock associated with the lead holder 110 and the rotor 130 . Second, referring also to FIGS. 11 and 12 , the size of the detonator 140 can be reduced and/or the detonator 140 can be moved further away from the longitudinal axis A in the SAFE arrangement of the S&A mechanism 100 . Accordingly, the portion of the detonator 140 that is visible through the high-G aperture 116 is at least reduced in the SAFE arrangement of the S&A mechanism 200 ( FIG. 11 ). In the ARMED arrangement of the S&A mechanism 100 , as shown in FIG. 12 , the detonator 140 is aligned with the longitudinal axis A.
[0045] The operation 1000 of the explosive device 10 in general, and the S&A mechanism 100 in particular, will now be described in further detail with reference to FIG. 13 . The explosive device 10 can be maintained 1010 for extended periods, e.g., a service life of 10 years or more and/or a shelf life of 20 years or more, before being deployed 1020 . While the explosive device 10 is being maintained 1010 , the explosive device 10 is held in an inoperative state that includes avoiding an unintended explosion as a result of dropping the explosive device 10 or as a result of vibration, e.g., during transportation. The explosive device 10 continues to be held in an inoperative state after being deployed 1020 and before being launched 1030 . While the explosive device 10 is being deployed 1020 , the inoperative state includes avoiding unintended explosion as a result of flight shocks or vibration, temperature shocks, and close contact with other high-G aperture 116 of the lead holder 110 explosive devices 10 . When launched 1030 , e.g., dispensed by a weapon containing as many as several thousand of the explosive devices 10 , each S&A mechanism 100 transitions from the SAFE arrangement to the ARMED arrangement while avoiding unintended explosion as a result of launch shock, set-back acceleration, and angular acceleration. For example, this transition from the SAFE arrangement to the ARMED arrangement can occur in less than one second and approximately 600 milliseconds in response to the explosive device 10 achieving a predetermined velocity, e.g., 900 feet/second, and a predetermined spin, e.g., 1250 rpms. Flight time of the explosive devices 10 after being dispensed from the weapon can be approximately several seconds or less until impact 1040 . The impact 1040 can occur in several different circumstances. According to a first circumstance 1040 a, the explosive device 10 strikes generally solid ground but misses a mine. The impact force of the explosive device 10 in the first circumstance 1040 a can be in an approximate range of 4,030 G to 8,000 G. According to a second circumstance 1040 b, the explosive device 10 strikes a mine on/in the ground. The impact force of the explosive device 10 in the second circumstance 1040 b can be in an approximate range of 20,000 G to 67,000 G. According to third and fourth circumstances 1040 c and 1040 d, the explosive device 10 strikes a mine located in shallow or deep water, respectively. The impact force of the explosive device 10 in the third and fourth circumstances 1040 c and 1040 d can be at least approximately 1,130 G. According to a fifth circumstance 1040 e, the explosive device 10 enters water and strikes the seabed but misses a mine. The impact force of the explosive device 10 in the fifth circumstance 1040 e can be in an approximate range of 1,130 G to 4,030 G. In general, the time between impact 1040 and the momentum of the explosive device 10 being halted can be approximately 25 milliseconds. If the explosive device 10 does not strike a mine, e.g., as in the first and fifth circumstances, the explosive device 10 self destructs after the delay period, e.g., 150 milliseconds, thereby avoiding the explosive device 10 becoming unexploded ordnance.
[0046] Certain embodiments according to the present disclosure provide a variety of features and advantages as will now be described. Prior to dispensing from the weapon, the rotor containing the detonator is held SAFE and out of line with an RPM lock. After dispensing from the weapon, each explosive device enters the wind stream and spins up to a minimum rpm, whereupon the RPM lock(s) and the rotor are unlocked, and the rotor moves to the ARMED arrangement. When the rotor is positioned in the ARMED arrangement, the firing pin is aligned with the detonator. The S&A mechanism may comprise rotor arm locks that can only be activated in the operating environments. Thus, the S&A mechanism may include a rotor arm lock for preventing rotor bounce between ARMED and SAFE arrangements. The rotor arm locks provide robust safety features for both the SAFE and ARMED arrangements. The transition from SAFE to ARMED takes place at a within a specified environment, is prompt, and permanent.
[0047] Certain embodiments in accordance with the present disclosure include redundant and opposing detents or RPM locks. The RPM locks can include two opposing, lightly loaded pins to hold a rotational member in place under severe shock and vibration conditions. The opposing pins insure positive retaining force by at least one pin regardless of the direction or axis of the external force. This also eliminates any required rotational orientation of the internal components of the S&A mechanism.
[0048] The S&A mechanism is responsive to environmental exposures and provides target discrimination. Certain embodiments according to the present disclosure include at least one shear pin capable of discriminating between “hard” and “soft” targets. Upon impact with a soft target, the low-G shear pin fails allowing the low-G firing pin to initiate a time delay primer. Depending on the impact media, the explosive device may continue to travel for approximately 20-25 milliseconds. If the explosive device has not impacted a hard target, the delay primer output pressurizes the high-G firing pin after a time delay, striking the detonator and igniting the explosive lead and warhead explosive. Upon impact with a hard target, both the low-G shear pin and the high-G shear pins fail. The detonator is initiated approximately 100-400 microseconds after impact for destroying the target. The delay primer may continue to burn until the time delay expires. The discriminating feature of the S&A mechanism is repeatable and reliable to provide each target type with the appropriate function time, which can be different for each target.
[0049] Certain embodiments according to the present disclosure include a self-contained, all mechanical S&A mechanism that responds to specific environmental exposures and provides target discriminating in a small package, e.g., approximately 0.5 inches diameter and 6.5 inches length. Accordingly, an explosive device having a miniature warhead coupled to an S&A mechanism is capable of discriminating between different levels of impacts. The explosive devices may be configured to meet the requirements of MIL-STD-1316. Further, the S&A mechanism is self-contained and operates without input from an external power supply and there are no external connections. Additionally, the S&A mechanism functions with two separate and independent external environments. In some embodiments, the S&A mechanism does not rely on “stored energy” devices.
[0050] Certain embodiments in accordance with the present disclosure are configured to mechanically discriminate between hard and soft targets with a low piece part count that simplifies assembly steps and reduces component costs. Neither electrical connections nor an external power source is required. A stainless steel exterior and hermetically sealed welded construction provide extended service and shelf life. Additionally, embodiments in accordance with the present disclosure comply with MIL-STD-1316 and are resistant to HERO or E3 due to an enclosed Faraday shield.
[0051] The S&A mechanism may be contained in a very small envelope including a welded metal construction that is hermetically sealed to prevent corrosion, moisture intrusion and loss of operation capability. The S&A mechanism may also be configured to protect against susceptibility to HERO or EMI, EMC radiation. The explosive devices comprise all U.S. Department of Defense approved explosives.
[0052] The explosive devices also self-destruct after a time delay. The probability of an individual explosive device impacting a mine is low. Therefore the majority of the explosive devices must self-destruct to reduce or eliminate the presence of unexploded ordnance. This self-destruct feature is initiated after the ARMED arrangement occurs, and is accomplished whether or not the explosive device impacts a mine.
[0053] Certain embodiments according to the present disclosure can include some or all of the following components of the S&A mechanism. The S&A mechanism can include three subassemblies contained in two outer sleeves. These three subassemblies can include a low-G firing pin subassembly, a high-G firing pin subassembly, and a rotor and initiation subassembly. The low-G firing pin subassembly can include the aft housing, the low-G firing pin, the low-C shear pin, an RPM lock and the aft sleeve. The high-G firing pin sub assembly, or S&A mechanism mid-body, can include the high-G firing pin, the delay primer holder, the delay primer, and the high-G shear pin. The rotor and initiation subassembly can include the lead holder, the rotor, the detonator, another RPM lock, the rotor arm lock, and the explosive lead.
[0054] The lead holder can include the explosive lead, portions of an RPM lock, and portions of a rotor arm lock. The explosive lead can include an approved explosive (e.g., CH 6 ) to transfer detonation from the detonator to the warhead explosive. The explosive lead can be pressed and sealed in a metal cup. The RPM lock for the rotor can include opposing, high density (e.g., tungsten) pins, nominal biased by resilient members that have a spring rate which will be overcome at a predetermined spin rate of the explosive device. Opposing pins ensure there is at least one pin engaging the rotor during all non-operating shock or vibration. The rotor can contain the detonator, e.g., a stab detonator, and portions of the rotor arm lock. The rotor arm lock can include two locking pins located in the rotor and biased apart by another resilient element, e.g., one or more springs. When the rotor reaches the end of its ravel in the ARMED arrangement, the pins are pushed into a counter bore in the lead holder, thereby locking the rotor in the ARMED arrangement and preventing bouncing of the rotor between the ARMED and SAFE arrangements. The detonator or stab detonator comprises an explosive initiator and is contained in the rotor. The high-G firing pin strikes the detonator to initiate ignition of the explosive lead. The high-G firing pin is held in place by one or more shear pins in the SAFE arrangement. The high-G shear pins can be made from extruded aluminum wire with low elongation mechanical properties. When subjected to a predetermined deceleration force, the mass of the body connected with the high-G firing pin will shear the high-G shear pins, and the high-G firing pin will strike the detonator with sufficient energy to initiate the detonator. The high-G firing pin surrounds the delay primer holder in a telescopic relationship and can be made from stainless steel. The delay primer holder contains the delay primer, which is the first to function in the low g impact mode, and causes the high-G firing pin to strike the detonator. After a specified time delay, the delay primer provides a source of gas pressure sufficient to shear the high-G shear pins and move the high-G firing pin to initiate the detonator. The low-G firing pin is coupled to a mass that shears the low-G shear pin to initiate the delay primer. The low-G firing pin is held in place by one or more low-G shear pins sized to release the low-G firing pin at the first and least impact level, i.e., less than that required to shear the high-G shear pins. Individual low-G shear pins can be made from extruded aluminum wire having low elongation mechanical properties. The low-G firing pin can additionally be held in place by an RPM lock in the SAFE arrangement. The outside surface of the low-G firing pin can be dry film lubricated to smoothly slide in the aft outer sleeve. An aft housing can be a stainless steel component that connects to the tail assembly and includes the low-G shear pin and the RPM lock associated with the low G firing pin. After the components that make up the low-G firing pin sub-assembly are installed, the aft housing is welded to the aft sleeve. The outer sleeves can be welded to the lead holder and aft housing. The outer sleeves can position and encase the internal components of the S&A mechanism.
[0055] The high-G firing pin and the low-G firing pin can be approximately identical stainless steel firing pins. Features of the firing pins are promulgated for firing stab initiated devices and can include an outer diameter that is knurled and pressed into the respective firing pin bodies.
[0056] Weights for the RPM locks and the pins for the rotor arm lock can be made from Tungsten alloy and dry film lubricated. The weights hold the firing pins in place and protect the shear pins until a minimum rpm is achieved at which time the RPM locks disengage from the firing pin. All of the weights in the RPM locks can be identical and operate at the same parameters. Springs for the RPM locks can be sized to release the RPM weights at a specified spin rpm. The springs can be fabricated from stainless steel.
[0057] Certain embodiments according to the present disclosure operate according to a method that includes some or all of the following steps. The S&A mechanism is maintained in the SAFE arrangement under all environmental conditions unless two environmental conditions occur in order. First, the explosive device must encounter a minimum air speed, e.g., 900 feet/second. This environment imparts a rotation to the explosive device via canted fins of the tail assembly. Second, the explosive device must achieve a minimum spin of 1,200 rpm. This spin causes the weights of the RPM locks to retract against the springs of the RPM locks. This unlocks the rotor, which moves to align and lock the detonator in the ARMED arrangement. A first impact with either a hard target (e.g., a mine) or a soft target (e.g., water and sand) initiates a pyrotechnic sequence. The explosive devices that impact a hard target detonate approximately immediately, and the explosive devices that impact a soft target (mine) detonate after a time delay (e.g., 50-150 milliseconds). The impact forces required to initiate one of the pyrotechnic sequences can be at least approximately 1,130 G for a soft target and at least approximately 20,000 G for a hard target.
[0058] Other methods according to the present disclosure can include (1) at least one explosive device being launched into a minimum velocity air stream, e.g., approximately 900 ft/sec; (2) the air stream reacting with the canted tail fin causing rotation of the explosive device; (3) the explosive device spinning at a minimum speed, e.g., approximately 12,000 rpm; (4) retracting the RPM locks due to centrifugal force and disengaging at an intermediate speed, e.g., approximately 9,000 rpm; and (5) moving the rotor with the detonator from the SAFE arrangement to the ARMED arrangement and locking the rotor in the ARMED arrangement. If the explosive device impacts a soft target causing at least approximately 900 G of deceleration, shearing the low-G shear pins and initiating the delay primer with the low-G firing pin. If the explosive device impacts a hard target causing at least approximately 20,000 G of deceleration, shearing the high-G shear pins and initiating the detonator with the high-G firing pin. If the explosive device does not impact a hard target, pressurizing the high-G firing pin with the delay primer, shearing the high-G shear pins, and initiating the detonator with the high-G firing pin. All explosive devices launched into the air stream will self-destruct within 150 milliseconds of their impact, regardless of the impact type.
C. Alternative Embodiments Or Features
[0059] From the foregoing, it will be appreciated that specific embodiments of the disclosure have been described herein for purposes of illustration, but that various modifications can be made without deviating from the spirit and scope of the disclosure. For example, the S&A mechanisms and related concepts presented in this disclosure can be used in applications other than those discussed above. For instance, some techniques used in the disclosed S&A mechanisms can be used in various platforms that spin or do not spin. Some techniques could be used in small caliber projectiles that spin due to rifling, small rocket motors that use canted nozzles or thrust motors to spin. The opposing locking feature could also be released by non-spinning action, such as a spring loaded band, sliding ban or simple released such as bore riders. The discriminating initiation feature can be tailored to different targets by adjustment of the firing pin mass and shear pin strength. The self destruct time is a function of the time delay primer which can be micro seconds to several seconds to several minutes. Moreover, specific elements of any of the foregoing embodiments can be combined or substituted for elements in other embodiments. Furthermore, while advantages associated with certain embodiments of the disclosure have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, embodiments of the disclosure are not limited except as by the appended claims. | A SAFE and ARM mechanism includes an elongated casing having a first end and a second end. A high-G force firing pin is arranged relatively near to the first end and a low-G force firing pin is arranged relatively near to the second end. A detonator is arranged between the high-G force firing pin and the first end. When a G-force within a first range of magnitudes is applied to the casing along its longitudinal axis, the low-G force firing pin is displaced to strike a portion of the high-G force firing pin, and if a G-force within a second range of magnitudes is applied to the casing along its longitudinal axis, the high-G force firing pin is displaced to strike the detonator. The device may become ARMED in response to a centrifugal force generated by spinning the casing on its longitudinal axis. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a holder for writing instruments, specifically for ballpoint pens, which comprises a main body having at least two sockets therein for holding the writing end of a writing instrument.
A large variety of such holders of different geometrical shapes and holding means are known. Usually such holders, especially holders for at least two writing instruments comprise a main body, the base of which can be placed on a solid support such as a desk or the like, and which has at least two sockets in a row, into which the writing ends of the writing instruments can be put. Frequently such holders are combined with other devices e.g., a plate for holding pencils, rubbers and the like.
In practice, the desires of various buyers differ from each other and therefore quite a number of such holders have to be kept in stock by the trade, that is, holders which are suited for only two writing instruments, for three writing instruments or for some other definite number of writing instruments. Quite often one of the writing instruments of a buyer's original set gets lost, so that then one of the recesses will always stay empty.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved holder for writing instruments of a simple and aesthetic shape and which can easily be produced at low costs.
It is a further object of the present invention to provide such a holder, which is easily usable for different purposes especially for holding different numbers of writing instruments.
It is a preferred object of the present invention to provide such a holder, which is equally suitable for different purposes without applying different exchangeable parts, more specifically a holder which can be adjusted for the desired number of writing instruments by the wholesale dealer or even the buyer himself.
In accomplishing the foregoing objects there is provided a holder for writing instruments, especially for ballpoint pens, a main body having at least two sets of different numbers of sockets for holding and fixing the writing ends of the writing instruments, which are movable into accessible position within said main body. Preferably the main body comprises at least two separate parts, the first of which has the sockets for holding the writing ends of the writing instruments and the second of which is a casing part, the two parts being movably connected to each other in such a way that, at the choice of the user, either one or two or three sockets can be moved into exposed position for use.
According to a preferred embodiment of the invention, the first part having the sockets is connected to the casing part in such a way that it can easily be exchanged.
In this way the wholesale dealer can easily change the holder in a simple manner according to the wishes of the clients, just by exchanging the part having the sockets, if it does not have the right number of sockets.
According to another embodiment of the invention, the parts are arranged in such a way that the part having the sockets and the casing part can be connected to each other in at least two different relative positions.
According to a further embodiment of the invention, the casing part has at least one window for exposure of any desired number of sockets. Covering and exposing of the sockets can also be done advantageously by means of a slide.
The holder can easily be produced at low cost. The separate parts are produced by injection molding, especially from plastic material, e.g., from impact resistance polystyrene. The changing of the position of the parts relative to each other can be done by the wholesaler, the retailer, or the buyer himself, always starting with the same device. No exchangeable parts or replacements have to be kept available. Nevertheless, the device has the same appealing closed shape in any position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a holder comprising a preferred embodiment of the invention;
FIG. 2 is a perspective view of the holder of FIG. 1 but having the covering part turned into a different position;
FIG. 3 is a top view of the holder of FIG. 1 having the covering part turned into a third position;
FIG. 4 is a drawing of the separate parts of which the holder of FIG. 1 is composed;
FIG. 5 is a cross section along the line I--I of FIG. 3;
FIG. 6 is a perspective view of another embodiment;
FIGS. 7 and 8 are views of still another embodiment in two different positions; and
FIGS. 9, 10 and 11 are views of further embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 5 show a preferred embodiment of the present invention. As can be seen from these figures, the cross section of this holder vertical to its base is an equilateral triangle. The holder is made of several parts, which are produced by injection molding, e.g. from impact resistant polystryene.
As can be seen from FIG. 4, the holder 1 comprises a casing part 2 into which an insertion part 3 is firmly insertable. The insertion part, which is shaped as a tube with triangular profile has, near its right end in FIG. 4, three hollow sockets 11, 14, 16, extending inwardly and which taper towards the inside and which constitute the holding means for the writing ends of the writing instruments. In order to close the insertion part 3 at the front side near the sockets, a plate 20 is provided, which can be firmly inserted into the corresponding front end of the insertion part 3. The parts are arranged in such a way that upon inserting the insertion part 3 into the casing part 2, the section of part 3 which includes the sockets extends out of the casing part 2.
On the outwardly extending portion of the insertion part a covering part corresponding to the casing part 2 can be slid with a friction fit. This covering part has windows 12, 13, 19, which open respectively toward the edges on each of its three surfaces 4, 5, 6. By comparing the figures it is seen that these three windows have different lengths. Thus, the length of window 12 is sufficient to expose only socket 11 of insertion part 3 when the covering part is slid onto the extending portion of the insertion part 3, as can be seen in FIG. 1. Thus, FIG. 1 shows the holder in a condition in which it is suited for holding one single writing instrument. In order to make the holder of FIG. 1 usable for two writing instruments, the covering part may be removed from the position in FIG. 1 along the dotted line direction 7 as shown by arrow 8 and turned 120° around the axis 7 in the direction of arrow 9 and then slid back onto the insertion part 3. In this position the window 13 on the side surface 6 of the covering part exposes the sockets 11 and 14 in a position for use. In the same way the longest window 19 can be placed into using position by repeating the changing of the position of the covering part. Thus, all three sockets 11, 14, 16 may be exposed for use.
In order to provide a holder which provides a choice between one to four sockets, it is only necessary to provide for a quadratic cross section vertical to the base of the holder instead of the equilateral triangle, so that four sides of the square are available for placing four windows of different sizes.
It can be appreciated that the holder has an appealing shape and secure stand and that besides the sockets a surface is provided which can be used for other purposes, e.g., for supporting a calendar or advertisement, or decorations, ornaments, reliefs and the like.
Instead of using a movable covering part, the part having the sockets can be exchangeably connected to the casing part. In this case a set of 2, 3, or 4 exchangeable insertion parts has to be kept available for the same holder, whereby these exchangeable parts differ from each other only in the number of sockets.
Essentially the same advantages can be accomplished if the casing part has only one window and the isertion part is insertable into different positions and has different sets of different numbers of sockets on its surfaces which define the sides of the triangle.
In the embodiment of FIG. 6, the basic shape of the holder is essentially unchanged. The cross section of the tube shaped casing part 26 is an equilateral triangle and one end of a corresponding insertion part 27 is inserted into this casing part 26. The insertion part has on each of its three surfaces, which define the triangle, a set of sockets. FIG. 6 shows a holder 25 wherein the side of the insertion part which is in exposed position, exposes a set of two sockets 32 and 33. This position is determined by a window 31 on one of the sides of the casing part 26. In order to change the number of recesses, the inserting part 27 is removed from the casing part 26 in the direction of the line 29 according to the arrow 28 and turned 120° around the line 29 in the direction of the arrow 30 and is replaced in the casing part 26 in this position. In this embodiment as well the casing part 26 provides large exposed surfaces which are available for display purposes, as is schematically indicated by field 34.
In the embodiment of FIGS. 7 and 8, the holder has a pyramidical shape wherein the four-sided surface is the base of the holder. In this case there is provided a pyramidically shaped casing part 41 which has a window 46 on only one triangular surface. An equally pyramidical insertion part 42 is insertable from below into the casing part 41 in the direction of the axis 43. This insertion part has four sets of different numbers of sockets on its four triangular surfaces. Any of these sets of sockets can be aligned with the window 46 of the casing part 4 according to the position of the insertion part within the casing part. In the position shown in FIG. 7, the holder 40 exposes three sockets 47, 48, 49 through the window 46 for use. Changing only requires removing the insertion part 42 in the direction of the axis 43 downwards according to the arrow 44 turning it 90° around the axis in the direction of the arrow 45 and putting it back into the casing part. Thus, the two sockets 50, 51 are moved into exposed position through the window 46, whereas the remaining sets of sockets including the socket 52 which is shown by a dotted line in FIG. 8, are covered by the casing part 41.
In the holder 55 of FIG. 9, the same principle is used but the holder has a conical shape. Here as well the casing part 56 and the insertion part 57 have corresponding conical shapes and can be moved relatively to each other in the direction of the axis of the cone and can be turned rleative to each other around this axis, so that different sets of sockets can be aligned with the window 58 of the casing part. In the example shown, the insertion part has two flat surfaces 59, 63 interrupting its conical surface within the region of each of the sets of sockets. These flat surfaces ensure that the sockets 60, 61, 62 of the same set are parallel to each other. In those examples according to FIGS. 6 to 9 which are described above, the parts can, of course, also be arranged in such a way that the insertion part has only one set of a maximum number of the desired sockets whereas the casing part has windows of different sizes on its various surfaces, and these windows can each be aligned with the one set of sockets by changing the position of the parts relative to each other, whereby each window exposes a certain different number of sockets of this set.
In especially simple cases any of the simple basic geometric shapes, which were described above, can be used for the casing part, whereby sets of different numbers of sockets are provided on each of the pheripherical surfaces of the basic geometric body and are always exposed so that just by placing the body in a different position and using a different surface as the base a different set of sockets can be brought into a position suitable for the user.
In the holder 65 according to FIG. 10, the shape of the cross section is an equilateral triangle. Thus, the holder has three different peripheric surfaces 66, 67, 68. On each peripheric surface a set of sockets is provided. Thus, surface 66 has two sockets 69, 70. The surface 67 has a set of three sockets 72 to 74 whereas the surface 68 has only one socket 71.
In the position shown in FIG. 10, the surface 68 serves as the base of the holder. It is presumed that in FIG. 10 the left exposed surface of the triangle points into the using position. By moving the holder 65 onto one of the other two possible base surfaces 66, 67, the other sets of sockets, namely, the sets on the surfaces 67 or 68 can be placed in using position. This embodiment is especially simple, but it has the disadvantage that all sets of sockets are constantly exposed and by this the impression is lost, that the particular holder has been produced especially for the one definite purpose. The special advantage of the holder accordin to the before described embodiments is the fact that it can not easily be recognized that the same holder can be used for different purposes.
In the example shown in FIG. 11, the possibility of changing the holder for different numbers of sockets is also provided but the changing is effected in a slightly different way. Whereas in the embodiments according to FIGS. 1 to 9 a part comprising either several sets of sockets or several windows had to be turned into different positions relative to a second part, so that this turning part might be named a rotary slide, in the example according to FIG. 11 a flat slide which is movable in one plane is provided in order to effect the changing.
The holder 80 according to FIG. 11 comprises a casing part 81 which has the same preferable geometric shape as the casing part in FIG. 1.
Within the casing part 81 is provided an insertion part 79 which can be effected similarly to the insertion part 3 of FIGS. 1 to 5 and can comprise a set of three tapered sockets 86, 87, 88. The casing part 81 has a window 84 which is aligned with the three recesses in such a way that normally the window 84 exposes all three sockets at the same time. Yet between the insertion part 79 and the casing part 81 a flat slide 83 is placed, which is movable in the direction of the double arrow and which has three sets of apertures close to each other which can be aligned with the window 84 of the casing part by moving the slide 83. In the position shown in FIG. 11, the aperture 85 of the slide is in alignment with the socket 87 of the insertion part 79 and the window 84 of the casing part 81. Thus, the holder is usuable for one ball pen. By means of an appendage 92 of the slide 83 which extends outwardly through a slot 93 in the casing part 81, the slide can be moved into the other two positions wherein either the set of apertures 90 or the set of apertures 91 are aligned with the window 84 of the casing in order to expose two or three sockets of the insertion part.
The described embodiments of the invention show holders, the base surface of which can be placed on a plane horizontal support as is usually done. But, the invention can also be used for holders which are fixed in another way, e.g., are fixed by means of a suction cup or a magnetic button on a vertical surface. | A holder for pens has one part provided with a plurality of sets of pen-receiving sockets having a different number of sockets in each set and another part that can be positioned to expose for use any selected one of the sets. Another form provides the sets of sockets on different faces of a body so that the body may be positioned to direct any one of the sets in a desired direction of use. | 1 |
BACKGROUND AND SUMMARY
[0001] The present disclosure relates to a door leaf for external sliding doors of passenger cars, high speed railroad cars and subway cars, hereinafter collectively referred to as vehicles. The sliding doors include a frame and a panel which is made of glass or at least partially transparent plastic and is, if appropriate, of multi-component design.
[0002] In this context, external is to be understood as meaning that the doors are sliding doors via which the train can be entered from the outside, and the term does not refer to the spatial position of the sliding door in the opened state. Such sliding doors or their door wings can, as in most cases, be pushed in the opened state along the external wall of the train. The doors continue to be visible from the outside or else, for example, can also disappear during the opening process in the interior of an external wall which is of hollow design.
[0003] Such door leaves, with surfaces which are embodied “with a single layer”, may be made of glass or transparent plastic. In the text which follows, for the sake of better comprehensibility, only the term glass is used. Such door leaves are provided on the inside with a frame in order to ensure the necessary mechanical stability and have been known for some time. The glass panel can be embodied here in one piece or divided. In the text which follows, for the sake of better comprehensibility the glass panel is mentioned only in the singular. A disadvantage with this door is the uneven design, which is provided as a result of the frame and which, particularly during the opening of the door, leads to the risk of a person's fingers or objects becoming trapped in the region of the door frame.
[0004] Generally, door leaves, to which an entire series of activation devices, mounts and coupling points for the door drive and door guides have to be attached, have been known for a long time. In order to make these door leaves visually appealing and functional, they have had glazed regions since their beginnings over 150 years ago. In the last few years, spot welding of the metal frames, which was customary earlier, has been dispensed with in favor of bonding technology. The surface coating has been changed to an environmentally friendly, water-soluble surface coating. Various control lines for sensors, i.e., trapping prevention means, activation elements and lighting systems etc. have been laid between the two metal surfaces, or planking, which bound the door leaves on the inside and outside. In addition, thermal and sound insulating materials have been arranged and the windows have not only been fabricated from safety glass but also from thermally and acoustically insulating material, in a suitable design to increase the comfort of the passengers and save energy.
[0005] The present disclosure relates to a door leaf which does not have the aforesaid disadvantages and which meets the optical and functional requirements at least as much as the door leaves according to the prior art.
[0006] According to the present disclosure, the glass panel is arranged on the inside of the profiles which form the frame. As a result, a completely planar surface is obtained in the interior of the vehicle, the surface eliminating as well as possible the risk of trapping. On the outside, a surface is obtained which is significantly better aligned with the surface of the surrounding railroad car body than in the case of doors according to the prior art. This significantly improves the visual appearance.
[0007] The term “planar” is not be understood as planar in the mathematical sense over the entire surface of the door leaf. The door leaf can of course, as in the prior art, be adapted to the cross-sectional shape of the railroad car body. Planar means that the unavoidable local and often relatively hard transitions at the junction between the glass and the frame in the prior art are eliminated or are moved to the outside of the railroad car.
[0008] Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic view of an interior of a two-wing door, according to the present disclosure.
[0010] FIG. 2 is a view of a section along the line II-II of FIG. 1 .
[0011] FIG. 3 is a schematic view of FIG. 1 .
DETAILED DESCRIPTION
[0012] As is shown in FIG. 1 , door leaf or door wing 1 , for vehicles, which vehicles may include passenger cars, high-speed railroad cars, and subway cars, according to the present disclosure, includes three horizontally extending profiles 2 and two vertically extending profiles 3 . It is within the scope of the present disclosure that more than three horizontally extending profiles 2 are also conceivable. Profiles 2 , 3 can have the same cross section as one another, or else may not have the same cross section. Profiles 2 , 3 may be cut at their comers or in a central region where they meet with a mitered joint. This may depend on the profile used and a location or guidance of cables or lines, and can be selected by a person skilled in the art and having knowledge of the present disclosure.
[0013] On an inside of a frame 5 , which is formed by the profiles 2 , 3 , a glass panel 4 is bonded. Glass panel 4 can be divided, as shown in FIG. 1 , in the horizontal direction in the region of the central horizontal profile 2 in order, during mounting, to reduce the weight of the individual panels and to simplify repair in the case of a fracture. The panel or pane 4 may be rounded at corners 7 in a region of a secondary closing edge 6 .
[0014] As shown in FIG. 2 , it is possible, as is the case with subway fittings, for the door leaves or wings 1 to be in the form of a general cylinder and to be of bent design in a vertical section. This does not constitute a problem for glass or for plastic. As suggested in FIG. 2 , upper transverse or horizontally-extending profile 2 can be used as an attachment point for a suspension means 8 of the door leaf or wing 1 and that the profiles 2 which are located at an external edge are provided with sealing devices 9 .
[0015] FIG. 3 shows the vertical profiles 3 , and in a region of the secondary closing edge 6 , a sealing profile 9 . In a region of a main closing edge 10 , sealing profile 9 is also embodied as a finger protection 11 . The door leaf 1 , not shown in FIG. 3 , is symmetrical thereto. Or in the case of a single-wing door, the door leaf 1 is symmetrical to the main closing edge 10 on the door frame. The door leaf 1 has a correspondingly congruent profile.
[0016] As shown in FIG. 3 , arrow 12 points to one of the edges which lie on the inside of the doors, according to the prior art, and form the trapping risk there. Since, according to the present disclosure, these edges are formed on the outside, this risk is eliminated. As is also clear, the thickness of the profiles 2 , 3 decreases with a slope on their inner side, that is, the side facing the center of the door surface. This facilitates automatic cleaning of the outside and damps the travel noise due to elimination of the customary sharp edge.
[0017] Although the present disclosure has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present disclosure is to be limited only by the terms of the appended claims. | A door leaf for external sliding doors of railway cars. The door leaf includes a frame and at least one partially transparent panel. | 8 |
This application is a continuation, of application Ser. No. 08/611,687, filed Mar. 6, 1996 now U.S. Pat. No. 5,906,848.
BACKGROUND OF THE INVENTION
The present invention is directed to a process for the removal of undesired lipophilic contaminations and/or residues, which are contained in beverages or in vegetable preparations.
Organic lipophilic compounds have been used for decades as plant protective products, pest control compounds and pesticides.
Some of these highly active toxic substances have the undesired characteristic that they are degraded after accumulation in lipophilic parts of plants either only insufficiently or are not degraded at all.
It is known, that the plant protective compound pentachloro nitrobenzene is transformed in the degradation products pentachloro aniline, pentachloro anisol and pentachloro benzene.
These degradation products are also toxic.
Said highly active toxic compounds, which are degraded only insufficiently or are not degraded at all, are thus accumulated in the soil, in the water and in the human body or in the bodies of animals, combined with corresponding negative effects.
Thus, the whole food chain, the end of which is the human being, is poisonned.
Due to these reasons the use of certain active compounds, such as DDT and lindan, has been strongly restricted or forbidden.
The use of supercritical carbon dioxide (CO 2 ) is only applicable to a restricted extent for the removal of these undesired highly active toxic substances; see for example EP PS 0 382 116 B1.
Contaminated water maybe purified by using active carbon.
This purification process is very expensive and is not selective.
Lipophilic contaminations, especially lipophilic poisons of the above mentioned kind, may be removed with halogenated hydrocarbons, such as methylene chloride, chloroform, carbon tetrachloride, or with alkanes containing 5 to 7 carbon atoms, such as petroleum ether, hexane.
But these substances for removing of the lipophilic poisons of said kind are themselves toxic, detrimental to the environment and to some extent highly explosive, whereby their use is combined with high risks.
Various national and international laws and implementing regulations have been promulgated, wherein maximum amounts of poisons are defined.
It if an object of the present invention to provide a process with which these highly active toxic compounds may be removed nearly quantitative and selectively from beverages or vegetable preparations.
This process is also cheap as well as simple and safe during realization.
In this process no toxic and/or easy inflammable agents are used.
This process has no drawbacks for the environment.
With this process the maximum amounts of poisons as defined in national and international laws and implementing regulations shall be at least accomplished and preferably will be significant below these amounts.
The inventive process meets the above mentioned objects.
SUMMARY OF THE INVENTION
The inventive process for the removal of undesired lipophilic contaminations and/or residues, which are contained in beverages or in vegetable preparations, is characterized in that
in a first step the corresponding beverage or the corresponding vegetable preparation is mixed with such a lipophilic phase, that the contaminations and/or residues to be removed are dissolved in this lipophilic phase and are concentrated herein nearly quantitatively,
in a second step the liphophilic phase, which contains now the contaminations and/or residues, is separated from the corresponding beverage or from the corresponding vegetable preparation, and
in a third step the so purified beverage or so purified vegetable preparation is obtained.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the invention, the lipophilic contaminations and/or residues can be pesticides, plant protective products, pest control agents, especially fungicides, insecticides, acaricides, nematicides, herbicides, or environmental poisons, such as polyhalogenated, especially polychlorinated, biphenyls, dioxines, or organic solvents, such as benzene, chloroform, carbon tetrachloride, or synthesis residues, such as alkylhalides, halogenated aromatic substances and heteroatomic aromatic substances, such as chloropyridines, including any mixtures thereof.
More particularly, the lipophilic contaminations and/or residues can be:
α-hexachloro cyclohexane,
β-hexachloro cyclohexane,
γ-hexachloro cyclohexane, also named lindan,
δ-hexachloro cyclohexane,
pentachloro nitrobenzene, also named quintozen,and its degradation products, such as pentachloro aniline, pentachloro anisol, pentachloro benzene, dichloro-diphenyl-trichloroethane, also named DDT, and its degradation products, such as dichloro-di-phenyl-dichloro-ethylene, also named DDE, endosulfan, also named thiodan, pyrethrum and its synergists, piperonylbutoxide, hexachloro benzene, aldrin, dieldrin, heptachlor, and methoxychlor.
Beverages which may be treated according to the invention may include drinking water, table-water, mineral water, wine, beer, fruit-juices, tea or lemonades.
Vegetable preparations which may be treated according to the invention may include infusions, tinctures, fluids, spissum extracts, siccum extracts, dropping solutions, juices, tonics, or injectable preparations.
The vegetable preparations can be partial or complete extracts from medical and/or spice plants or parts thereof, especially:
Abelmoschus moschatus L (Semen);
Acorus calamus (Rhizom);
Aesculus hippocastanum L. (Semen);
Allium-species (e.g. A. cepa L., A. ursinum L., A. sativum L.:Bulbus);
Alpinia officinarum Hance (Rhizom);
Anethum graveolens L. (Fructus);
Angelica archangelica L., various subspec. (Rhizoma);
Angelica dahurica (Radix);
Angelica formosana (Radix);
Anthemis nobilis L. (Chamomilla romana, Herba);
Apium graveolens L. (Fructus);
Arctium major Gaertn. (Radix);
Arctostaphylos uvaursi Spreng. (Folium);
Arnica montana L. (Flos);
Artemisia absinthium L. (Herba);
Artemisia dracunculus L. (Herba);
Asparagus offic. (Herba, Rhizoma, Radix);
Atropa belladonna L. (Folium);
Berberis vulgaris L. (Cortex, Radix);
Betula-species (Folium);
Brassica nigra (L.) Koch (Semen);
Camellia sinensis (Folia);
Carum carvi L. (Ftudtus);
Cetraria islandica (L.) Ach.;
Chrysanthemum vulgare Asch. (Herba);
Cinnamomum-species (Cortex);
Citrus-species (Folium, Flavedo, Fruct.);
Copaifera reticulate Ducke (Balsam);
Coriandrum sativum L. (Fructus);
Cucurbita pepo L. (Semen);
Cuminum cyminum L. (Fructus);
Curcuma-species (Rhizoma);
Cusparia officinalis (Willd.) Eng. (Cortex);
Dipterocarpus turbinatus Gaertn. (Balsamum);
Drosera species (D. rotundifolia L., D.ramentacea Burch; Herba);
Echinacea angustifolia D.C. (Radix);
Echinacea purpurea (L.) Moench (Radix);
Elettaria cardamonum (L.) White et Mathon (Fructus);
Equisetum arvense L. (Herba);
Eucalyptus globulus Labill. (Folium);
Fagopyrum vulgare Hill. (Herba);
Foeniculum vulgare Miller (Fructus);
Fumaria offic. (Herba);
Gaultheria procumbens L. (Folium);
Ginkgo biloba L. (Folium);
Hamamelis virginiana L. (Cortex, Folium);
Hedeoma pulegioides (L.) Pers. (Herba);
Herniaria glabra L. (Herba);
Humulus lupulus L. (Flos, Glandulae);
Hypericum perforatum L. (Herba);
Hysopus officinalis L. (Herba);
Ilex paraguariensis St. Hil. (Folium mate);
Illicium verum Hook. f. (Fructus);
Iluna helenium L. (Rhizoma);
Iris pallida Lam. (Rhizoma);
Jasminum grandiflorum L. (Flos);
Laurus nobilis L. (Folium, Fructus);
Lavendtla officinalis, further species (Flos);
Lawsonia inermis L. (Folium);
Levisticum officinale Koch (Radix);
Melaleuca: various varieties (Folium);
Matricaria chamomilla L. (Flos);
Melilotus officinalis (L.);
Lam. em. Thuill. (Herba);
Melissa officinalis L. (Herba);
Mentha-species and its varieties (Folium);
Myristica fragrans Houttuyn (Arillus, Semen);
Myrtus communis L. (Folium);
Ocimum basilicum L. (Herba);
Ocotea sassafras (Cortex);
Oenanthe aquatica (L.) Poir (Fructus);
Olea europaea (Folia);
Olibanum (Resinum);
Ononis spinosa L. (Radix);
Origanum-species (Herba);
Orthosiphon stamineus Benth. (Herba);
Panax ginseng Meyer (Radix);
Petroselinum crispum (Mill.) Nym. (Fructus, Herba);
Phaseolus vulgaris L. (Fructus sine Semine);
Pimenta dioica (L.) Merill (Fructus);
Pimpinella anisum L. (Semen);
Piper angustifolium Ruiz. et Pavon. (Folium);
Piper methysticum Forster (Radix);
Pogostemon patchouli Pell. (Folium);
Prunus laurocerasus L. (Folium);
Rhus aromatics Ait. (Cortex);
Rosmarinus officinalis L. and its species (Folium);
Rubia tinctorum L. (Radix);
Rubus fructicosus L. (Folium);
Ruta graveolens L. (Herba);
Sabal serulata Benth et Hook (Fructus);
Salix alba L. (Cortex) and all species thereof;
Salvia-species (Folium);
Santalum album L. (Liqnum);
Sarothamnus scoparius (L.) Wimmer (Herba);
Sassafras albidum (Nutt.) Nees (Liqnum);
Satureja hortensis L. (Herba);
Scopolia carniolica Jacq. (Radix);
Solidago serotina Ait. (Herba);
Solidago virgaurea L. (Herba);
Syzyqium aromaticum Merr. et Perry (Flores, Folium);
Taraxacum officinale Web. (Herba and Radix);
Thymus serpyllum L. (Herba);
Thymus vulgaris L. Herba;
Tilia cordata Mill. and T. platyphyllos Scop. (Flos);
Urtica dioica L. (Folium, Radix);
Valeriana officinalis and its varieties (Radix);
Vitis vinifera (Folia); and
Zingiberis officinale Roscoe (Rhizoma).
The vegetable preparations can be partial or complete extracts from alkaloids and/or flavonoides and/or saponines and/or bitterings and/or terpenes containing plants or parts thereof selected from: Betulae (Folia); Boldo (Folia); Camelliae (Folia); Chelidonii (Herba); Chinae (Cortex); Chrysanthemi (Herba); Crataegi (Folia c. Floribus); Cynarae (Folia); Gentianae (Radix); Ginkgo (Folia); Ginseng (Radix); Hederae helic. (Herba); Hippocastani (Semen); Liquiritiae (Radix); Orthosiphonis (Folia); Passiflorae (Herba); Rauwolfiae (Radix); Salicis (Cortex); Solidaginis (Herba); Tiliae (Flores); and Vitis vinifera (Folia, Fructus).
The liphophilic phase can be of animal, vegetable, mineralic or synthetic origin, and is especially not toxic, not easily inflammable, not explosive and not volatile, and is preferably selected from:
fats, such as cocoa butter, coconut fat;
oils, such as neutral oils, sunflower oil, fractionated coconut oil, such as miglyol;
waxes, such as stearins, yoyoba oil, beeswax, spermaceti, carnauba wax;
paraffins, including vaseline;
lipoids; and
sterols.
All of the aforementioned compounds, as simple compounds or as mixtures, preferably fulfill the requirements/definitions in the "Deutsches Arzneibuch, DAB", or in the British Pharmacopoe, BP, or according to the Food Chemical Codex, FCC, in the United States of America, or must correspond to these requirements/definitions, respectively.
According to the process of the invention, in the first step the mixing of the components is conducted at such a temperature, which lies between the freezing point and the boiling point of the respective mixture, whereby a temperature in the range from room temperature to 70° C. is preferred.
In the first step of the process, the components can be mixed together for about 1 hour, preferably using means of shaking or stirring. In the second step the separation is preferably conducted either by means of a phase separation of 2 liquid phases or by means of a phase separation of a liquid phase and a solid phase. In the second step the separation of 2 liquid phases is preferably conducted by membrane-separation, using glass-, metal-, ceramic- and synthetic membranes with pore sizes in the range from 0.001 to 1.0 micrometers, more preferably from 0.1 to 0.3 micrometers. Preferred synthetic membranes are those made of polypropylene or teflon.
In the process according to the invention separated lipophilic phase, containing the contaminations and/or residues, can be subjected to a water vapor distillation, and the obtained distillate, which contains lipophilic, volatile-in-steam smell components and/or taste components, can be added back as such or after previous removal of the water to the purified beverage or purified vegetable preparation (at the end of the third step).
For vegetable preparations, which contain alkaloids, at least one physiologically acceptable acid can be added during the mixing step in such a way and in such an amount to adjust the pH to a level whereby the alkaloids are present as salts. Examples of such acids include ascorbic acid, citric acid, acetic acid.
In the second step of the inventive process a separation of two phases is carried out.
Thereby either two liquid phases of a liquide phase and a solid phase are separated.
When two liquid phases are separated from each other, then this is realized preferably by means of membrane technology.
Thereby tubular membranes, so called "cross-flow"-membranes, are preferred.
Thereby the used membrane is preferably conditioned previously.
When it is desired, that the hydrophilic phase is obtained as filtrate and the lipophilic phase as retentate, then the membrane is conditioned at room temperature with a hydrophilic solvent, especially water, or with a hydrophilic mixture of solvents, for example a mixture of 85 vol.- % water and 15 vol.- % ethanol, for a few minutes, for example 5 to 20 minutes, especially 10 minutes.
In principle it is also possible to condition the membrane with the hydrophilic phase itself.
When it is desired, that the lipophilic phase is obtained as filtrate and the hydrophilic phase as retentate, then the membrane, in analogy to the above mentionned statements, is conditioned with a lipophilic solvent or a mixture of solvents or with the lipophilic phase itself.
It is preferred to obtain the hydrophilic phase as filtrate.
After this conditioning of the membrane the mixture to be separated, for example 9 parts hydrophilic preparation and 1 part lipophilic phase, is subjected to the above mentionned continuous membrane separation during such a long time until the desired amount of the purified hydrophilic preparation is obtained as filtrate.
When a liquid phase and a solid phase are separated from each other, then this is realized by means of conventional technology.
In this case cocoa butter is preferred as lipophilic phase.
Thereby cocoa butter in a molten state is stirred in into the hydrophilic preparation to be purified, and which phase has preferably a temperature of about 50° C.
This mixture is stirred during about 1 hour at a temperature of about 50° C.
Then the mixuture is allowed to cool to room temperature or to a temperature in the range from 5° C. to 10° C., especially 8° C.
At these temperatures the cocoa butter becomes solid and may be separated from the purified hydrophilic preparation.
In the inventive process during the extraction step both the hydrophilic phase and the lipophilic phase are preferably each in a liquid state of aggregation.
The following examples illustrate the present invention.
EXAMPLE 1
400 g of Extr. Ginseng e. rad. spir. spiss. were mixed with 800 g of distilled water and were brought under stirring to a temperature of 50° C.
After reaching the temperature 40 g of cocoa butter in molten state were added under stirring, and this mixture was stirred during 1 hour at a temperature of 50° C.
Then the mixutre was stored for 2 days at 8° C.
Then the solid mass, which contained cocoa butter and the contaminations, and which mass was at the surface of the mixture was left off and thrown away.
The residue, that is the liquid extract solution, was filtered through a folded filter.
The obtained filtrate was concentrated under vacuum at a temperature of 50° C. in maximum to the starting weight of 400 g.
The pesticide values of the so obtained product are mentioned in table 1.
EXAMPLE 2
1000 g of extract ginseng e. rad. spir. spiss. were mixed with 4000 g of distilled water and were brought under stirring to a temperature of 50° C.
After reaching the temperature 100 g of cocoa butter in molten state were added under stirring, and this mixture was stirred during 1 hour at a temperature of 50° C.
The mixture was then cooled to 30° C. and was filtered by means of closs-flow in an ultra filtration device during 2 hours.
The membrane (polypropylene-tube module) of the cross-flow-device was conditioned previously during 10 minutes with distilled water, which had a temperature from 30° C. to 42° C.
The obtained filtrate was concentrated at a temperature of 50° C. in maximum to the starting weight of 1000 g.
The pesticide values of the so obtained product are mentioned in table 1.
EXAMPLE 3
500 g extract Ginseng e. rad. spir. spiss. were mixed with 2000 g of distilled water and were stirred during 15 minutes at a temperature of 50° C.
Then were added 50 g of miglyol 812, and it was stirred for a further hour at a temperature of 50° C.
This mixture was allowed to stand over night at room temperature.
Then this mixture was filtered by means of cross-flow in an ultra filtration device during 1 hour.
The membrane (polypropylene-tube module) of the cross-flow-device was conditioned previously during 10 minutes with distilled water at room temperature.
The obtained filtrate was concentrated at a temperature of 50° C. in maximum to the starting weight of 500 g.
The pesticide values of the so obtained product are mentioned in table 1.
TABLE 1______________________________________ Values in the starting values in the treated material material (in ppm) (in ppm) example 1 example 2 example 3______________________________________α-HCH *) <0.020 <0.010 <0.010 <0.010γ-HCH 0.038 0.011 <0.010 <0.010β-HCH 0.0760 <0.010 <0.010 <0.010δ-HCH 0.700 0.130 0.035 0.025Pentachloro benzene <0.100 <0.100 <0.100 <0.100Pentachloro anisol <0.100 <0.100 <0.100 <0.100Pentachloro aniline 1.66 0.360 0.130 0.130Quintozen <0.02 0.012 <0.010 <0.010.______________________________________ *) HCH: Hexachloro cyclohexane | A process for the removal of undesired lipophilic contaminations and/or residues, which are contained in beverages or in vegetable preparations. The process comprises a first step in which a beverage or vegetable preparation is mixed with a lipophilic phase such that the contaminations and/or residues to be removed are dissolved in the lipophilic phase and are concentrated therein nearly quantitatively. In a second step, the lipophilic phase, which contains the contaminations and/or residues, is separated from the beverage or vegetable preparation. Finally, the purified beverage or vegetable preparation is obtained. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of patent application Ser. No. 09/919,128, filed Aug. 1, 2001 and now U.S. Pat. No. 6,630,095, entitled “Method for Making Composite Structures,” having Steve Slaughter and John C. Fish as inventors, which application is assigned to same assignee as the present application, and is hereby incorporated by reference.
BACKGROUND
Description of Related Art
Generally, vacuum assisted resin transfer molding (VARTM) processes include laying up layers of a material of any unimpregnated fiber and/or fabric on top of a mold. A vacuum bag is placed about the lay-up and sealed to the mold. A peel ply may be placed on top of the lay-up and between the layers and mold surface to insure that the vacuum bag can be removed from the completed part and that the part can be removed from the mold. Resin is introduced into the vacuum bag, while a vacuum is drawn from beneath the lay-up. This causes the resin to flow through the lay-up. Thereafter, the resin flow is terminated and the resin in the assembly is cured. This may require that the resin be heated to curing temperature. To insure even distribution of resin into the lay-up, a resin distribution medium is placed on top of the lay-up, which is designed to cause the resin to evenly distribute there across eliminating resin-starved areas.
Many types of resin distribution have been proposed. Some inventions describe the use of a perforated film between the lay-up and vacuum bag. Resin is fed from the top through the vacuum bag, through the perforated film and into the lay-up. A spring is located at the periphery of the lay-up, but under the perforated film. The spring is coupled to a vacuum line, thus providing a channel such that resin can be more readily transferred into the lay-up. This reference is of interest for disclosing the use of a perforated film and the use of a spring to provide a channel to the perforated film. However, a special perforated film is required and there is still the problem of insuring that the resin reaches all parts of the perforated film. Other inventions use a wire mesh as a distribution medium in a vacuum assisted molding process. However, a wire mesh may not necessarily be made to conform to a complex contoured part. Furthermore, an open mesh may allow resin to flow too freely into the lay-up prior to the wire mesh becoming filled with resin, thus filling the lay-up near the inlet tube and creating resin starved area further away from the inlet tube.
Other techniques use channels placed on the lay-up that act as resin distribution paths and become reinforcements on the finished part. This technique is generally not used on parts that do not require reinforcement.
In general terms, the design of the distribution medium includes two parts: spaced apart lines and an array of raised pillars. In detail, the distribution medium can be a crisscrossed pattern of mono-filaments with raised segments at the intersection of the mono-filaments; a series of spaced apart strips forming a grid structure; or a knitted cloth with raised segments being areas of increased bulk. A central conduit in the form of a spring is positioned over the peel ply and is in communication with the resin inlet port and acts as a central distribution line. Other techniques use the distribution mediums on either side of the lay-up. These distribution mediums are specialized products and may unduly raise fabrication costs.
A method also exists wherein multiple layers of fibrous reinforcements are assembled into a desired configuration on a support tool, with one of the layers of fibrous reinforcement defining a resin carrier fabric (distribution medium) that extends beyond the periphery of the other layers. The layers of fibrous reinforcements and tool are covered with a flexible layer to form an envelope that encapsulates the fibrous reinforcements. A vacuum source evacuates air from the envelope. Resin is introduced into the envelope and fibrous reinforcements by using a flow path through the one layer used as the resin carrier layer. After the fibrous reinforcements have been impregnated, the resin flow is terminated and the resin is cured. What is really happening is that an additional fibrous layer is added to the fiber reinforcements making up the part that extends there beyond and over flow channels at the periphery of the tool. In one embodiment, this extra fibrous layer is separated from the “part” by a release or peel ply. In a second embodiment, the fibrous layer is integral with the part. This distribution medium is designed for use in a process where the resin is introduced from the peripheral edges of the lay-up.
A system also exists wherein a pair of preforms with different permeabilities are installed in a mold separated by a separation layer. Different resins are injected into each preform by the vacuum assisted resin transfer method. The key to this process is the use of a separation layer having permeability lower than the permeability of either of the fiber preforms.
Another invention uses a dual bag within a bag concept. Both bags are sealed to the mold surface with the lay-up within the inner bag. The outer bag incorporates protrusions. A vacuum is first drawn from between the inner and outer bag. This forces the protrusions into the inner bag creating a pattern of channels. A vacuum is then drawn from between the mold surface and inner bag. Resin is then flowed into the lay-up through the channels. Thus the inner bag acts as a resin distribution medium. This apparatus requires a custom vacuum bag, which may raise fabrication costs.
Other devises in the general area of substance distribution provide systems wherein substance held in a reservoir is released to the surface of an applicator by rupturing a substantially fluid-impervious barrier layer in an interior cavity. The pressure provided to rupture the barrier is provided by manually squeezing and the material is then spread onto a third surface with the applicator. The apparatus does not contemplate a direct flow of material through the ruptured barrier onto the ultimate surface or build-up of pressure through a change in atmospheric pressure in the filling apparatus or through the weight of accumulating material.
SUMMARY
An apparatus for controlling the flow of liquid, gaseous, or particulate solid substances from a substance distribution system and method for making same is provided. In some embodiments, a system for controlling the flow of a substance includes a distribution medium for receiving the substance, and a containment layer adjacent to the distribution medium. The containment layer substantially prevents the substance from flowing until the distribution medium is substantially filled with substance.
In an alternate embodiment, a method for controlling the flow of a substance includes placing a distribution medium adjacent to a containment layer; introducing the substance into the distribution medium; configuring the containment layer to substantially prevent the substance from flowing from the distribution medium until the substance distribution medium is substantially filled with substance; and reconfiguring the containment layer to allow the substance to flow to an intended destination.
In still another embodiment, a resin distribution system includes a resin distribution medium for receiving the resin. The resin distribution medium includes a first principle side facing the resin inflow and a second principle side facing the mold surface. A resin containment layer is positioned adjacent to the resin distribution medium. The resin containment layer is configured to substantially prevent the resin from entering the lay-up until the resin distribution medium is substantially filled with resin.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention may be better understood, and their numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference symbols in different drawings indicates similar or identical items.
FIG. 1A is a cross-sectional view of an embodiment of a system for distributing layers of one or more substances.
FIG. 1B is a cross-sectional view of another embodiment of a system for ting layers of one or more substances.
FIG. 2 is an exploded perspective view of the system illustrated in FIG. 1A .
FIG. 3 is an enlarged perspective view of an embodiment of the containment layer, wherein the containment layer is made of material that melts.
FIG. 4 is an enlarged perspective view of another embodiment of the containment layer, wherein the containment layer is made of a perforated heat shrinkable material.
FIG. 5 is an enlarged perspective view of another embodiment of the containment layer, wherein the containment layer is made of a highly perforated or highly embossed, frangible material.
FIG. 5A is partial enlarged view of FIG. 5 .
DETAILED DESCRIPTION
Referring to FIGS. 1A and 2 , an embodiment of a distribution system 10 for controlling and distributing the flow of liquid, gaseous, and particulate solid substances is shown including distribution medium 22 and containment layer 24 . Distribution medium 22 includes a first principle side facing an inflow of substance and a second principle side facing containment layer 24 . Containment layer 24 is designed to substantially prevent substance from flowing to an intended destination until distribution medium 22 is substantially filled with substance.
In some embodiments, distribution system 10 can be utilized to fabricate composite materials. System 10 includes mold 12 and mold surface 14 . For purposes of illustration a flat mold surface 14 is shown, however, mold surface 14 can be curved, can include a moving conveyor belt, or any other surface for evenly distributing resin over one or more layers of material 16 A through 16 D to form lay-up 16 . In some embodiments, peel ply layers 18 A, 18 B can be positioned adjacent one or both of the outer sides of lay-up 16 . Peel ply layers 18 A, 18 B are typically made of a porous material to allow resin to easily pass through without bonding to mold surface 14 or containment layer 24 as resin-impregnated lay-up 16 equilibrates into its final state. In other embodiments, peel ply layers 18 A, 18 B may not be included.
In some embodiments, outer sheet 26 , also referred to as a vacuum bag, includes inlet port 28 positioned adjacent distribution system 10 and sealed at its marginal edges 30 to mold surface 14 by sealant tape 32 or other suitable means to form chamber 34 . An example of a sealant tape 32 that can be utilized is Tacky Tape™ manufactured by Schnee-Moorehead, Irving, Tex. Vacuum outlet port 35 can be installed between mold surface 14 and marginal edge 30 of outer sheet 26 for drawing a vacuum in chamber 34 .
In some embodiments, substance enters inlet port 28 , while a vacuum is drawn from outlet port 35 . The vacuum causes outer sheet 26 to collapse down around distribution medium 22 . Without distribution medium 22 , it would be difficult to evenly distribute resin over lay-up 16 , and substance starved areas or even voids could be created in the cured lay-up 16 . With substance distribution medium 22 , however, resin can flow evenly lay-up 16 , greatly reducing the chance of forming voids and the like in the final product.
FIG. 1B shows another embodiment of distribution system 10 that include vacuum outlet ports 35 ′ in mold 12 . Outlet ports 35 ′ can be positioned in one or more locations in mold 12 . Portions of outlet ports 35 ′ extending from mold 12 can be fitted to a vacuum source to draw outer sheet 26 to collapse around distribution medium 22 and lay-up 16 . In some embodiments, one or more outlet ports 35 ′ are positioned around the periphery of lay-up 16 in areas where there are likely to be gaps between lay-up and outer sheet 26 . As many inlet ports 28 and outlet ports 35 ′ as necessary can be utilized, thereby enabling distribution system 10 to be utilized to fabricate components in a variety of shapes and sizes. Further, a combination of one or more outlet ports 35 ( FIG. 1A ) and outlet ports 35 ′ can be utilized in the same distribution system 10 .
Lay-up 16 can comprise one or more layers of material, such as woven fiberglass, graphite or other composite reinforcement material. Peel plies 18 A and 18 B can be made of a material such as coated fiberglass, which is porous to resin so that resin can easily pass through without bonding to mold surface 14 or containment layer 24 as the resin cures. A suitable peel ply material is Release Ease 234TFP, manufactured by Airtech Products, Incorporated, Huntington Beach, Calif.
In some embodiments of distribution system 10 , a material suitable for use as outer sheet 26 is impregnated Nylon, which can be obtained from numerous suppliers such as the previously mentioned Airtech Products. When the substance being distributed is resin, distribution medium 22 can be comprised of any suitable material. For example, a knitted mono-filament UV stabilized high density polyethylene can used as distribution medium 22 , such as commercially available SolarGuard™ manufactured by Roxford Fordell Company, Greenville, S.C. Anther suitable product for distribution medium 22 is Colbond 7004 manufactured by Colbond, Incorporated, Enka, N.C. Colbond 7004 is a random orientated, heat fused mono-filament material.
Referring to FIGS. 1A and 3 , in other embodiments, temperature sensitive containment layer 24 A has a melting point such that containment layer 24 A dissolves or melts after substance is at least partially distributed in distribution medium 22 . Once containment layer 24 A melts, the substance can flow to its intended destination. Distribution system 10 can include means for applying heat to temperature sensitive containment layer 24 A. Heating can be done either directly by means such as raising the ambient temperature, blowing heated air, conducting electricity through a metallic frame, chemical reaction, or other suitable means. Heat can also be applied to substance containment layer 24 A by heating the substance before, during, or after the substance contacts containment layer 24 A. Other materials that dissolve can be used for containment layer 24 A in addition to, or instead of, containment layers 24 A that dissolve when heated.
In some embodiments, a temperature sensitive containment layer 24 A includes a meltable substance layer 36 and porous veil material 37 . An example of a suitable material for temperature sensitive containment layer 24 A for use with resin is Blue Max Tak Tu on Reemay (a polyester non-woven veil), manufactured by The Blue Max Company, Anaheim, Calif. The Blue Max Tak Tu material is a low temperature melting resin 36 that is applied to a porous veil material 37 .
Referring to FIG. 4 , another embodiment of containment layer 24 B includes a plurality of holes 40 in a heat shrinkable material. Holes 40 are a size such that substance will not readily flow there through at ambient temperatures. Upon heating, the material of containment layer 24 B will shrink, causing holes 40 to increase in size, shown in dotted lines and indicated by numeral 40 ′, allowing substance to flow from substance distribution medium 22 . A suitable heat shrinkable material for use with resin substances includes Intercept Shrink film manufactured by FPM, Incorporated, Brownstone, Me.
Referring to FIGS. 1 , 5 and 5 A, in some embodiments, containment layer 24 C is a porous film 42 includes a plurality of holes or very closely spaced perforations 44 . The size of the perforations is selected to prevent or greatly reduce substance flow through substance containment layer 24 C. Holes 44 having a size such that substance will not flow there through when a vacuum is drawn to outlet port 35 at a first rate and will flow there through when a vacuum is drawn from outlet port 35 at a higher second rate. Calculating the size of holes 44 in substance containment layer 24 C can be accomplished as follows. For a layer of substance above substance containment layer 24 C, the hydrostatic pressure at the layer is by the equation:
PH=ρhg
Where: ρ is the density of the substance,
h is the depth (height) of the substance, and g is the gravitational constant
The “excess pressure” developed by the surface tension of the substance and the openings (perforations) in substance containment layer 24 C can be expressed as:
PE= 2 T/d
where T is the surface tension of the substance and
d is the perforation diameter (assumes circular perforation)
The governing equation for substance containment sets the hydrostatic pressure equal to the excess pressure:
ρhg= 2 T/d
Properties of a typical resin, such as Derakane 411 C-50 resin by Dow Chemical Company, Midland, Mich. are:
ρ=1265 kg/ m 3
T= 0.032 Newtons/meter
The maximum perforation size that overcomes the hydrostatic pressure is then:
d= 2 T /(( hg )=2(0.032)/(1265 ×h× 9.8)
d= 0.000005163 /h meters.
Using a typical thickness of a substance distribution medium, where the substance is resin, the substance height becomes 0.00635 m (0.25 in) and the maximum perforation size is:
d max =8.13×10 −4 meters (0.032 in).
For thicker substance distribution mediums, the maximum perforation size will decrease. Perforations larger than this maximum value may not contain the substance during infusion. Similarly, the minimum perforation size can be estimated by equating the excess pressure to the sum of the hydrostatic pressure and the vacuum pressure in the bagged assembly:
ρhg+PV =2 T/d
where PV will be on the order of one atmosphere. At sea level, PV is approximately 100 kiloPascals (kPa) and dominates the left side of the equation above. The minimum perforation size is then estimated by:
d min =2 T/PV= 2(0.032)/(100×10 3 )
d min =6.4×10 −7 meters=2.5×10 −5 inches
Perforations smaller than this minimum value may not permit substance to pass through the substance containment layer 24 C under vacuum pressure. The substance containment layer 24 C perforation size is then bounded by:
2.5×10 −5 inch< d< 0.032 inch
A suitable material for containment layer 24 C for use with resin substances is Easy Gardner Tree Wrap having round holes with a 0.015 inch diameter or Easy Gardner Weed Block with square holes of a similar size. Both of these materials are manufactured by Easy Gardner, Incorporated, Waco, Tex. This method of calculation can also be used to design the perforations for temperature sensitive containment layers 24 B ( FIG. 4 ).
In still other embodiments of distribution system 10 ( FIG. 1 ), containment layer 24 can be comprised of a layer of perforated material including a plurality of embossed holes. Sufficient pressure can be applied to containment layer 24 to cause the perforations to release and allow the substance to flow once it is distributed in distribution layer 22 . Distribution system 10 can be modified to include means for applying pressure to the substance in distribution layer 24 to induce tearing of the holes in containment layer 24 . Such means include physically applying pressure to the substance, applying vacuum pressure, such as by drawing a vacuum on chamber 34 , or other suitable means. Containment layer 24 can also be configured to tear upon application of sufficient weight of the substance. Distribution medium 22 can be configured to allow sufficient substance to accumulate to apply the required weight to containment layer 24 .
Other embodiments include containment layer 24 fabricated from materials whose porosity properties change under application of different rates of vacuum, different rates of atmospheric pressure, and varying heat. Substances that can be distributed with distribution system 10 include any amounts of liquid, solid, and/or gaseous substances. Distribution layer 22 can be fabricated from any suitable material or combination of materials, and can include grids or other suitable openings to distribute the substance.
Various embodiments can include two or more distribution systems 10 that are configured to allow substances to be combined automatically at desired pre-selected time intervals, or upon application of means to at least partially remove containment layer 24 to allow the substance to flow toward its intended destination. For example, containment layer 24 in one distribution system 10 can be configured to release the substance when activated by an operator. The distributed substance can flow onto and chemically react with another substance in a second distribution system 10 . Containment layer 24 can be configured to release the combined substances either manually or automatically once the chemical reaction is complete.
Distribution medium 22 can be configured to accumulate all or a portion of the substance to be distributed by increasing the depth of the grid, including side walls around the perimeter of distribution medium 22 , or other suitable structure. Further, distribution system 10 can be oriented to allow substance to flow in any desired direction. Additionally, the substance can be forced to flow in any desired direction through the use pressure, pumps, or other suitable mechanism for inducing flow through distribution medium 22 .
While the present disclosure describes various embodiments, these embodiments are to be understood as illustrative and do not limit the claim scope. Many variations, modifications, additions and improvements of the described embodiments are possible. For example, those having ordinary skill in the art will readily implement the structures and methods disclosed herein, and will understand that any process parameters, materials, and dimensions are given by way of example only. The parameters, materials, and dimensions can be varied to achieve the desired structure as well as modifications, which are within the scope of the claims. Variations and modifications of the embodiments disclosed herein may also be made while remaining within the scope of the following claims. In the claims, unless otherwise indicated the article “a” is to refer to “one or more than one”. | A system for controlling the deposit of liquid, gaseous, and/or particulate solid substances from a staging medium and method of making same is provided. The system comprises a distribution medium for receiving substances, and a containment layer adjacent to the substance distribution medium. The containment layer substantially prevents substance from entering the deposit area until the distribution medium is substantially filled with substance, thereby helping to prevent uneven deposits of the substance. | 1 |
RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C. § 119(e) to U.S. provisional patent application, U.S. Ser. No. 60/684,865, filed May 26, 2005, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to nutritional compositions containing amino acids and/or vitamins and processes of their preparation.
BACKGROUND OF THE INVENTION
[0003] Oral supplementation with energy- and protein-rich foods is indicated for patients on modified consistency diets, for those with chronic disease and anorexia, and for those with chronic inflammatory disease or malignancy. In practice, commercial products provide a more reliable and acceptable method of supplementation than table foods.
[0004] Total parenteral nutrition (TPN) supplies all of the patient's daily nutritional requirements. TPN is used not only in the hospital for long-term administration but also at home (home TPN), enabling many persons who have lost small-bowel function to lead useful lives.
[0005] Severely malnourished patients who are being prepared for surgery, radiation therapy, or chemotherapy for cancer are given TPN before and after treatment to improve and maintain their nutritional status. In major surgery, severe burns, and multiple fractures, especially in the presence of sepsis, TPN reduces subsequent morbidity and mortality, promotes tissue repair, and enhances the immune response. Prolonged coma and anorexia often require TPN after intensive enteral feeding in the early stages. Conditions requiring complete bowel rest (e.g., some stages of Crohn's disease, ulcerative colitis, severe pancreatitis) and pediatric GI disorders (e.g., congenital anomalies, protracted nonspecific diarrhea) often respond well to TPN. Many premature infants who are unable to feed, and critically ill neonates admitted to neonatal intensive care units, also commonly benefit from TPN administration.
[0006] TPN requires water (30 to 40 mL/kg/day) and energy (30 to 60 kcal/kg/day), depending on energy expenditure, and amino acids (1 to 3 g/kg/day), depending on the degree of catabolism. Additionally, vitamins and minerals may also present in TPN. The following is a label indicated composition of TROPHAMINE, a well known in the art TPN solution.
Amino Acids 6% solution 10% solution Isoleucine USP 0.49 g 0.82 g Leucine USP 0.84 g 1.4 g Lysine 0.49 g 0.82 g (added as Lysine Acetate 0.69 g 1.2 g) USP Methionine USP 0.20 g 0.34 g Phenylalanine USP 0.29 g 0.48 g Threonine USP 0.25 g 0.42 g Tryptophan USP 0.12 g 0.20 g Valine USP 0.47 g 0.78 g Cysteine <0.014 g <0.016 g (as Cysteine HCl.H 2 O USP <0.020 g <0.024 g) Histidine USP 0.29 g 0.48 g Tyrosine 0.14 g 0.24 g (added as Tyrosine USP 0.044 g 0.044 g and N-Acetyl-L-Tyrosine 0.12 g 0.24 g) Alanine USP 0.32 g 0.54 g Arginine USP 0.73 g 1.2 g Proline USP 0.41 g 0.68 g Serine USP 0.23 g 0.38 g Glycine USP 0.22 g 0.36 g L-Aspartic Acid 0.19 g 0.32 g L-Glutamic Acid 0.30 g 0.50 g Taurine 0.015 g 0.025 g Sodium Matabisulfite NF <0.050 g <0.050 g (as an antioxidant) Water for Injection USP qs qs pH adjusted with Glacial Acetic Acid USP pH: 5.5 (5.0-6.0) Electrolytes (mEq/liter) Sodium 5 5 Acetate (CH 3 COO—) 54.4 97 [provided as acetic acid and lysine acetate] Chloride <3 <3
[0007] Prematurely born infants currently require TPN treatments during their hospitalization. Many problems related to abnormal amino acid metabolism produce abnormal concentrations of ammonia, a result of increased turnover of amino acids for energy production or an indicator of alterations in urea cycle metabolism.
[0008] From the newborn screening perspective, time is a critical component in the disease etiology. For most disorders, maternal metabolism insures near normal concentrations of amino acids; after birth, however, deviations from endogenous metabolism are no longer kept in check. With time and other influences such as diet, cell/protein turnover and numerous other factors, both deviations from normal and compensatory mechanisms may occur. Many disorders have been viewed in children who exhibit serious symptoms of disease, in which the abnormal biochemistry is quite evident. In newborn screening, however, since many of these processes have only just begun and no outward medical problems have yet presented, conditions in infants are all too easily affected by small changes in diet, collection time, and other such factors. Therefore, newborn screening will always remain a screening tool and never be 100% accurate. Newer technologies such as tandem mass spectrometry (MS/MS) have impacted newborn screening in a way that has allowed it to more closely approach 100% disease detection through the use of more accurate technologies and multi-analyte approaches.
[0009] Phenylketonuria is one amino acid metabolism disorder categorized as a defect in the metabolism of phenylalanine caused by a deficiency of the enzyme phenylalanine hydroxylase. The concentration of phenylalanine in blood is affected by the influx of phenylalanine into the blood stream through dietary absorption, i.v. administration, and protein breakdown. The rate of elimination or turnover of phenylalanine is affected primarily by the enzyme phenylalanine hydroxylase (irreversible enzyme) and secondarily through phenylalanine transaminase (reversible enzyme). The products of phenylalanine that may be important in the assessment of phenylalanine metabolism include tyrosine, phenylpyruvic acid, phenylethalamine, phenylacetate, phenylacetylglutamine, and hydroxyphenylacetate.
[0010] Significantly, prematurely born infants receiving TPN treatments may not be able to properly metabolize all TPN components, such as certain amino acids, even if the infants do not have a metabolic disorder. Therefore, prematurely born infants receiving TPN treatments may be at risk of receiving inadequate or excessive amounts of certain amino acids. Currently practiced nutritional adjustment strategies involve changing diet based on detection of a specific metabolic disorder. However, there are no known methods for providing adequate and safe TPN treatments to prematurely born but otherwise healthy infants who may be temporarily unable to metabolize certain components of the TPN solution.
[0011] Therefore, it would be advantageous to detect temporary inability to properly metabolize certain TPN components, as well as actual metabolic disorders, as early as possible and adjust TPN composition to avoid administration of an inadequate or excessive dose of any one of the components of the TPN solution, such as a specific amino acid or amino acids. It would also be advantageous to have a relatively simple and reliable process that does not require large quantities of blood samples and which process would allow physician to alter composition of TPN based on observation of concentrations of various analytes in patient's blood.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to nutritional compositions such as total parenteral nutrition (TPN) compositions and processes of preparing same. The advantage of the present invention lies in its ability to tailor TPN composition to the needs of each individual patient. Various components of the TPN composition may be increased, lowered, or removed based on the measurement of concentration of components and/or their metabolites in patient's blood.
[0013] Another advantage of the present invention lies in recognition of existence of a problem in administration of standard TPN treatments to prematurely born infants who do not have any specific metabolic disorders but who are unable to properly metabolize some of the components of the TPN solution due to their developmental stage. The present invention solves this problem by providing a method for monitoring metabolism of TPN solutions by prematurely born infants and accordingly adjusting composition of TPN solutions.
[0014] In one embodiment, the invention is directed to a nutritional composition comprising supplemental amino acids, prepared by a process comprising: a) determining patient's concentration of at least one blood amino acid indicator; b) observing if concentration of the at least one blood amino acid indicator determined in step (a) is above or below normal concentration; and c) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid corresponds to the at least one blood amino acid indicator of step (b) and wherein concentration of the at least one supplemental amino acid is in inverse correlation with the concentration of the at least one blood amino acid indicator. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0015] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising amino acids, the process comprising: a) determining patient's concentration of at least one blood amino acid indicator; b) observing if concentration of the at least one blood amino acid indicator determined in step (a) is above or below normal concentration; and c) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid corresponds to the at least one blood amino acid indicator of step (b) and wherein concentration of the at least one supplemental amino acid is in inverse correlation with the concentration of the at least one blood amino acid indicator. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0016] The patient's blood may be tested for and the TPN solutions of the invention may also be adjusted for other components besides amino acids, such as vitamins.
[0017] In another embodiment, the nutritional composition contains proteins and measurements of concentrations of blood amino acid indicators are used to correspondingly adjust protein diet. For example, above normal concentrations of blood amino acid indicators would require reduced levels of proteins in the nutritional composition.
DETAILED DESCRIPTION OF THE INVENTION
[0018] A term “nutritional composition” is meant to encompass a composition for administration to a patient, which serves the purpose of providing nutrition or providing supplemental nutrition to a patient. One example of a nutritional composition is a total parenteral nutrition (TPN) solution containing amino acids and/or vitamins.
[0019] A term “patient” is meant to encompass an animal, such as human, who may benefit from nutritional compositions of the invention, and who may or may not suffer from an ailment. In one preferred embodiment, the patient is a human infant. In another preferred embodiment, the patient is a prematurely born human infant. In yet another preferred embodiment, the patient is a prematurely born human infant who does not have a metabolic disorder.
[0020] A term “amino acid” is meant to encompass any organic acid containing one or more amino substituents. It is meant to encompass both α-amino and β-amino derivatives of aliphatic carboxylic acids. It is also meant to encompass so-called “essential amino acids” such as isoleucine, leucine, valine, threonine, methionine, tryptophan, phenylalanine, and lysine; so-called “semi-essential amino acids” such as histidine, tyrosine, cysteine, and taurine; and “non-essential amino acids” such as glycine, alanine, praline, serine, arginine, aspartic acid, and glutamine. The amino acids of the invention may be present in the composition in the form of pharmaceutically acceptable salts. For example, cysteine may be present as an aqueous hydrochloride salt solution. The amino acids of the invention may also be present in a modified form. For example, lysine may be present as lysine and/or as lysine acetate. Similarly, tyrosine may be present as a mixture of tyrosine and N-acetyl-L-tyrosine.
[0021] The term “pharmaceutically acceptable salt” refers to salts prepared from pharmaceutically acceptable non-toxic acids or bases including inorganic acids and bases and organic acids and bases. When the compounds used in the present invention are basic, salts may be prepared from pharmaceutically acceptable non-toxic acids including inorganic and organic acids. Suitable pharmaceutically acceptable acid addition salts for the compounds used in the present invention include acetic, benzenesulfonic (besylate), benzoic, camphorsulfonic, citric, ethenesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric acid, p-toluenesulfonic, and the like. When the compounds contain an acidic side chain, suitable pharmaceutically acceptable base addition salts for the compounds used in the present invention include metallic salts made from aluminum, calcium, lithium, magnesium, potassium, sodium and zinc or organic salts made from lysine, N,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and procaine.
[0022] A term “supplemental amino acid” is meant to encompass amino acid that is present in nutritional composition.
[0023] A term “blood amino acid indicator” is meant to encompass amino acid that is present in patient's blood. This term also encompasses metabolite or metabolites of any one specific amino acid as well as combinations of amino acid and its metabolite(s).
[0024] The term “metabolite” refers to a product of metabolism and is meant to encompass metabolites of metabolites.
[0025] A term “vitamin” is meant to encompass any of various organic substances that are essential in minute quantities to the nutrition, act as coenzymes and precursors of coenzymes in the regulation of metabolic processes but do not provide energy or serve as building units, and are present in natural foodstuffs or are sometimes produced within the body. Examples of vitamins are ascorbic acid, vitamin A, vitamin D, thiamine, riboflavin, pyridoxine, niacinamide, dexapanthenol, vitamin E, biotin, folic acid, vitamin B12, and vitamin K.
[0026] A term “blood vitamin indicator” is meant to encompass a vitamin present in patient's blood. This term also encompasses metabolite or metabolites of any one specific vitamin as well as combinations of vitamin and its metabolite(s).
[0027] A term “supplemental vitamin” is meant to encompass a vitamin present in nutritional composition.
[0028] A term “patient's concentration” is meant to encompass concentration of an amino acid or vitamin in patient's blood.
[0029] A term “normal concentration” is meant to encompass a concentration of amino acid(s), of vitamin(s), or of other substances that is observed in blood of a healthy subject.
[0030] A term “above normal concentration” is meant to encompass a concentration in patient's blood of amino acid(s) or vitamin(s) that is higher than concentration of respective amino acid(s) or vitamin(s) in healthy subject with physiological parameters that are similar to those of the patient.
[0031] A term “below normal concentration” is meant to encompass a concentration in patient's blood of amino acid(s) or vitamin(s) that is lower than concentration of respective amino acid(s) or vitamin(s) in healthy subject with physiological parameters that are similar to those of the patient.
[0032] A term “corresponding” as used in the present claims has meaning of being of the same identity but it also includes non-identical molecules such as an amino acid and its metabolite(s) and mixtures thereof, as well as vitamin and its metabolite(s) and mixtures thereof. Thus, a blood amino acid indicator may be a metabolite of such amino acid as phenylalanine, having phenylalanine as a corresponding supplemental amino acid.
[0033] A term “inverse correlation” is meant to encompass a relationship wherein an increase in one value corresponds to a decrease in another value and vice versa. For example, according to the present invention an observation of an above normal concentration of phenylalanine in patient's blood would require providing a nutritional composition with a lowered concentration of phenylalanine as compared to a standard concentration of phenylalanine in parenteral solution. Similarly, according to the present invention an observation of a below normal concentration of phenylalanine in patient's blood would require providing a nutritional composition with an increased concentration of phenylalanine as compared to a standard concentration of phenylalanine in parenteral solution. The degree of increase or decrease in concentration of an amino acid or a vitamin in nutritional composition is approximately proportional to corresponding deviation from normal in concentration of blood amino acid indicator or blood vitamin indicator.
[0034] A term “filter paper” is meant to encompass specimen collection paper that is well known in the art. Some known examples are Schleicher & Schuell's “Grade 903” filter papers and Whatman's “BFC 180” filter papers. Methods of collection of blood samples on filter papers are well known in the art.
[0035] A term “tandem mass spectrometer” is meant to encompass a well known in the art instrument consisting of two mass spectrometers in series connected by a chamber known as a collision cell. The sample to be examined is essentially sorted and weighed in the first mass spectrometer, then broken into pieces in the collision cell, and a piece or pieces sorted and weighed in the second mass spectrometer. Tandem mass spectrometry is used in newborn screening to detect molecules such as amino acids and fatty acids.
[0036] In one embodiment, the invention is directed to a nutritional composition comprising supplemental amino acids, prepared by a process comprising: a) determining patient's concentration of at least one blood amino acid indicator; b) observing if concentration of the at least one blood amino acid indicator determined in step (a) is above or below normal concentration; and c) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid corresponds to the at least one blood amino acid indicator of step (b) and wherein concentration of the at least one supplemental amino acid is in inverse correlation with the concentration of the at least one blood amino acid indicator. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0037] In another embodiment, the invention is directed to a nutritional composition comprising supplemental amino acids, prepared by a process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood amino acid indicator; d) determining if the concentration of the at least one blood amino acid indicator of step (c) is above or below normal concentration; and e) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid corresponds to the at least one blood amino acid indicator of step (d) and wherein concentration of the at least one supplemental amino acid is in inverse correlation with the concentration of the at least one blood amino acid indicator.
[0038] One example of above two embodiments would be a parenteral nutrition solution having half the standard concentration of phenylalanine when an observation is made of an increased concentration of phenylalanine in the blood of the patient.
[0039] Another example of above two embodiments would be a parenteral nutrition solution having double the standard concentration of isoleucine when an observation is made of a decreased concentration of isoleucine in the blood of the patient.
[0040] In another embodiment, the invention is directed to a nutritional composition comprising supplemental amino acids, prepared by a process comprising: a) determining patient's concentration of at least one blood amino acid indicator; b) observing if concentration of the at least one blood amino acid indicator determined in step (a) is above normal concentration; and c) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid that corresponds to the at least one blood amino acid indicator of step (b) is absent. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0041] In another embodiment, the invention is directed to a nutritional composition comprising supplemental amino acids, prepared by a process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood amino acid indicator; d) determining if the concentration of the at least one blood amino acid indicator of step (c) is above normal concentration; and e) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid that corresponds to the at least one blood amino acid indicator of step (d) is absent.
[0042] One example of above two embodiments would be a parenteral nutrition solution having no phenylalanine when an observation is made of an increased concentration of phenylalanine and/or its metabolite(s) in the blood of the patient.
[0043] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising amino acids, the process comprising: a) determining patient's concentration of at least one blood amino acid indicator; b) observing if concentration of the at least one blood amino acid indicator determined in step (a) is above or below normal concentration; and c) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid corresponds to the at least one blood amino acid indicator of step (b) and wherein concentration of the at least one supplemental amino acid is in inverse correlation with the concentration of the at least one blood amino acid indicator. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0044] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising supplemental amino acids, the process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood amino acid indicator; d) determining if the concentration of the at least one blood amino acid indicator of step (c) is above or below normal concentration; and e) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid corresponds to the at least one blood amino acid indicator of step (d) and wherein concentration of the at least one supplemental amino acid is in inverse correlation with the concentration of the at least one blood amino acid indicator.
[0045] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising amino acids, the process comprising: a) determining patient's concentration of at least one blood amino acid indicator; b) observing if concentration of the at least one blood amino acid indicator determined in step (a) is above normal concentration; and c) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid that corresponds to the at least one blood amino acid indicator of step (b) is absent. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0046] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising supplemental amino acids, the process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood amino acid indicator; d) determining if the concentration of the at least one blood amino acid indicator of step (c) is above normal concentration; and e) providing nutritional composition comprising supplemental amino acids, wherein an at least one supplemental amino acid that corresponds to the at least one blood amino acid indicator of step (d) is absent.
[0047] The present invention is also directed to a nutritional composition comprising supplemental vitamins, prepared by a process comprising: a) determining patient's concentration of at least one blood vitamin indicator; b) observing if concentration of the at least one blood vitamin indicator determined in step (a) is above or below normal concentration; and c) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin corresponds to the at least one blood vitamin indicator of step (b) and wherein concentration of the at least one supplemental vitamin is in inverse correlation with the concentration of the at least one blood vitamin indicator. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0048] In another embodiment, the invention is directed to a nutritional composition comprising supplemental vitamins, prepared by a process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood vitamin indicator; d) determining if the concentration of the at least one blood vitamin indicator of step (c) is above or below normal concentration; and e) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin corresponds to the at least one blood vitamin indicator of step (d) and wherein concentration of the at least one supplemental vitamin is in inverse correlation with the concentration of the at least one blood vitamin indicator.
[0049] One example of above two embodiments would be a parenteral nutrition solution having half the standard concentration of vitamin K when an observation is made of an increased concentration of vitamin K in the blood of the patient.
[0050] Another example of above two embodiments would be a parenteral nutrition solution having double the standard concentration of ascorbic acid when an observation is made of a decreased concentration of ascorbic acid or its metabolites in the blood of the patient.
[0051] In another embodiment, the invention is directed to a nutritional composition comprising supplemental vitamins, prepared by a process comprising: a) determining patient's concentration of at least one blood vitamin indicator; b) observing if concentration of the at least one blood vitamin indicator determined in step (a) is above normal concentration; and c) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin that corresponds to the at least one blood vitamin indicator of step (b) is absent. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0052] In another embodiment, the invention is directed to a nutritional composition comprising supplemental vitamins, prepared by a process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood vitamin indicator; d) determining if the concentration of the at least one blood vitamin indicator of step (c) is above normal concentration; and e) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin that corresponds to the at least one blood vitamin indicator of step (d) is absent.
[0053] One example of above two embodiments would be a parenteral nutrition solution having no niacinamide when an observation is made of an increased concentration of niacinamide or its metabolites in the blood of the patient.
[0054] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising vitamins, the process comprising: a) determining patient's concentration of at least one blood vitamin indicator; b) observing if concentration of the at least one blood vitamin indicator determined in step (a) is above or below normal concentration; and c) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin corresponds to the at least one blood vitamin indicator of step (b) and wherein concentration of the at least one supplemental vitamin is in inverse correlation with the concentration of the at least one blood vitamin indicator. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0055] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising supplemental vitamins, the process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood vitamin indicator; d) determining if the concentration of the at least one blood vitamin indicator of step (c) is above or below normal concentration; and e) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin corresponds to the at least one blood vitamin indicator of step (d) and wherein concentration of the at least one supplemental vitamin is in inverse correlation with the concentration of the at least one blood vitamin indicator.
[0056] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising vitamins, the process comprising: a) determining patient's concentration of at least one blood vitamin indicator; b) observing if concentration of the at least one blood vitamin indicator determined in step (a) is above normal concentration; and c) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin that corresponds to the at least one blood vitamin indicator of step (b) is absent. Step (a) may be performed by collecting patient's blood on a filter paper and analyzing patient's blood on the filter paper with a tandem mass spectrometer.
[0057] In another embodiment, the invention is directed to a process of preparation of nutritional composition comprising supplemental vitamins, the process comprising: a) collecting patient's blood on a filter paper; b) analyzing patient's blood on the filter paper of step (a) with a tandem mass spectrometer; c) observing from step (b) concentration of an at least one blood vitamin indicator; d) determining if the concentration of the at least one blood vitamin indicator of step (c) is above normal concentration; and e) providing nutritional composition comprising supplemental vitamins, wherein an at least one supplemental vitamin that corresponds to the at least one blood vitamin indicator of step (d) is absent.
[0058] In one preferred embodiment patient's concentration of blood amino acid indicators and/or blood vitamin indicators is measured daily with corresponding TPN composition adjustment. In another preferred embodiment patient's concentration of blood amino acid indicators and/or blood vitamin indicators is measured approximately every 12 hours. In some cases it may be necessary to measure patient's concentration of blood amino acid indicators and/or blood vitamin indicators at more frequent intervals. Since prematurely born infants without metabolic disorders with time become more competent in their ability to metabolize various components of the TPN solution, continuous monitoring of the composition of their blood allows for appropriate adjustments to be made to the TPN solution composition.
[0059] The formulations of the present invention include those suitable for oral, parenteral (including subcutaneous, intradermal, intramuscular, intravenous and intraarticular), rectal and topical (including dermal, buccal, sublingual and intraocular) administration. The most suitable route may depend upon the condition and disorder of the recipient. The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. All methods include the step of bringing into association amino acids and/or vitamins or their pharmaceutically acceptable salts or solvates thereof (“active ingredients”) with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both and then, if necessary, shaping the product into the desired formulation.
[0060] Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste.
[0061] A tablet may be made by compression or molding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, lubricating, surface active or dispersing agent. Molded tablets may be made by molding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide sustained, delayed or controlled release of the active ingredient therein.
[0062] Formulations for rectal administration may be presented as a suppository with the usual carriers such as cocoa butter or polyethylene glycol.
[0063] Formulations for topical administration in the mouth, for example buccally or sublingually, include lozenges comprising the active ingredient in a flavoured basis such as sucrose and acacia or tragacanth, and pastilles comprising the active ingredient in a basis such as gelatin and glycerin or sucrose and acacia.
[0064] Formulations for parenteral administration are preferred and include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient. Formulations for parenteral administration also include aqueous and non-aqueous sterile suspensions, which may include suspending agents and thickening agents. The formulations may be presented in unit-dose of multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of a sterile liquid carrier, for example saline, phosphate-buffered saline (PBS) or the like, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
[0065] It should be understood that in addition to the ingredients particularly mentioned above, the formulations of this invention may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavoring agents.
EXAMPLES
Example 1
High Isoleucine, High Leucine, Low Phenylalanine Amino Acid Parenteral Nutrition Solution
[0066] Following is an example formulation of an amino acid parenteral nutrition solution adjusted from standard TROPHAMINE solution by having increased concentration of isoleucine and leucine while having reduced concentration of phenylalanine.
Adjusted 6% Adjusted 10% Amino Acids solution solution Isoleucine USP 0.98 g 1.64 g Leucine USP 1.68 g 2.8 g Lysine 0.49 g 0.82 g (added as Lysine Acetate 0.69 g 1.2 g) USP Methionine USP 0.20 g 0.34 g Phenylalanine USP 0.15 g 0.25 g Threonine USP 0.25 g 0.42 g Tryptophan USP 0.12 g 0.20 g Valine USP 0.47 g 0.78 g Cysteine <0.014 g <0.016 g (as Cysteine HCl.H 2 O USP <0.020 g <0.024 g) Histidine USP 0.29 g 0.48 g Tyrosine 0.14 g 0.24 g (added as Tyrosine USP 0.044 g 0.044 g and N-Acetyl-L-Tyrosine 0.12 g 0.24 g) Alanine USP 0.32 g 0.54 g Arginine USP 0.73 g 1.2 g Proline USP 0.41 g 0.68 g Serine USP 0.23 g 0.38 g Glycine USP 0.22 g 0.36 g L-Aspartic Acid 0.19 g 0.32 g L-Glutamic Acid 0.30 g 0.50 g Taurine 0.015 g 0.025 g Sodium Matabisulfite NF <0.050 g <0.050 g (as an antioxidant) Water for Injection USP qs qs pH adjusted with Glacial Acetic Acid USP pH: 5.5 (5.0-6.0) Electrolytes (mEq/liter) Sodium 5 5 Acetate (CH 3 COO—) 54.4 97 [provided as acetic acid and lysine acetate] Chloride <3 <3
Example 2
Reduced Phenylalanine Concentration Amino Acid Parenteral Nutrition Solution
[0067] Following is an example formulation of an amino acid parenteral nutrition solution adjusted from standard TROPHAMINE solution by having reduced concentration of phenylalanine.
Adjusted 6% Adjusted 10% Amino Acids solution solution Isoleucine USP 0.49 g 0.82 g Leucine USP 0.84 g 1.4 g Lysine 0.49 g 0.82 g (added as Lysine Acetate 0.69 g 1.2 g) USP Methionine USP 0.20 g 0.34 g Phenylalanine USP 0.10 g 0.16 g Threonine USP 0.25 g 0.42 g Tryptophan USP 0.12 g 0.20 g Valine USP 0.47 g 0.78 g Cysteine <0.014 g <0.016 g (as Cysteine HCl.H 2 O USP <0.020 g <0.024 g) Histidine USP 0.29 g 0.48 g Tyrosine 0.14 g 0.24 g (added as Tyrosine USP 0.044 g 0.044 g and N-Acetyl-L-Tyrosine 0.12 g 0.24 g) Alanine USP 0.32 g 0.54 g Arginine USP 0.73 g 1.2 g Proline USP 0.41 g 0.68 g Serine USP 0.23 g 0.38 g Glycine USP 0.22 g 0.36 g L-Aspartic Acid 0.19 g 0.32 g L-Glutamic Acid 0.30 g 0.50 g Taurine 0.015 g 0.025 g Sodium Matabisulfite NF <0.050 g <0.050 g (as an antioxidant) Water for Injection USP qs qs pH adjusted with Glacial Acetic Acid USP pH: 5.5 (5.0-6.0) Electrolytes (mEq/liter) Sodium 5 5 Acetate (CH 3 COO—) 54.4 97 [provided as acetic acid and lysine acetate] Chloride <3 <3
Example 3
Phenylalanine Free Amino Acid Parenteral Nutrition Solution
[0068] Following is an example formulation of an amino acid parenteral nutrition solution adjusted from standard TROPHAMINE solution by having no phenylalanine.
Adjusted 6% Adjusted 10% Amino Acids solution solution Isoleucine USP 0.49 g 0.82 g Leucine USP 0.84 g 1.4 g Lysine 0.49 g 0.82 g (added as Lysine Acetate 0.69 g 1.2 g) USP Methionine USP 0.20 g 0.34 g Threonine USP 0.25 g 0.42 g Tryptophan USP 0.12 g 0.20 g Valine USP 0.47 g 0.78 g Cysteine <0.014 g <0.016 g (as Cysteine HCl.H 2 O USP <0.020 g <0.024 g) Histidine USP 0.29 g 0.48 g Tyrosine 0.14 g 0.24 g (added as Tyrosine USP 0.044 g 0.044 g and N-Acetyl-L-Tyrosine 0.12 g 0.24 g) Alanine USP 0.32 g 0.54 g Arginine USP 0.73 g 1.2 g Proline USP 0.41 g 0.68 g Serine USP 0.23 g 0.38 g Glycine USP 0.22 g 0.36 g L-Aspartic Acid 0.19 g 0.32 g L-Glutamic Acid 0.30 g 0.50 g Taurine 0.015 g 0.025 g Sodium Matabisulfite NF <0.050 g <0.050 g (as an antioxidant) Water for injection USP qs qs pH adjusted with Glacial Acetic Acid USP pH: 5.5 (5.0-6.0) Electrolytes (mEq/liter) Sodium 5 5 Acetate (CH 3 COO—) 54.4 97 [provided as acetic acid and lysine acetate] Chloride <3 <3
[0069] The invention being thus described, it is apparent that the same can be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications and equivalents as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | Nutritional compositions such as total parenteral nutrition (TPN) compositions and processes of preparing same are disclosed. The advantage of the present invention lies in its ability to tailor TPN composition to the needs of each individual patient. Various components of the TPN composition may be increased, lowered, or removed based on the measurement of concentration of components and/or their metabolites in patient's blood. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an invention for draining blood from the right atrium of a heart and more specifically relates to a two stage venous cannula with an expandable reinforcing member to prevent the cannula from kinking or collapsing in the perforated area where the reinforcing member is applied.
2. Description of Related Art
During cardiac surgery, it is often desirable to maintain circulation of blood through a patient's body. This is often done by connecting a patient to an extra-corporeal system that adds oxygen to and removes carbon dioxide from the blood, heats or cools the blood and provides impetus to the blood to cause the blood to circulate through the patient's vascular system.
It is necessary to connect the patient to the extra-corporeal circuit. This is usually done by inserting cannula into the patient's venous system near or in the heart to remove blood from the patient and direct it to the extra-corporeal circuit. After the blood has passed through the extra-corporeal circuit, the blood in infused into the patient's arterial system near the heart.
In practice, to remove the patient's venous blood, it is preferable to use a single two-stage venous cannula to simultaneously drain the right atrium and superior vena cava through an atrial basket while the inferior vena cava is drained through the distal tip segment. The distal tip is usually bullet-shaped to facilitate insertion.
The two-stage venous cannula was introduced by Sarns, Inc. of Ann Arbor, Mich. to the cardiac surgery market in the late 1970's as an alternative to bi-caval venous cannulation on procedures for coronary artery by-pass grafts (CABG). U.S. Pat. No. 4,129,129, issued to Bruce A. Amrine on Dec. 12, 1978 discloses such a two-stage venous catheter.
U.S. Pat. No. 4,639,252 issued to Michael N. Kelly, et al. on Jan. 27, 1987 discloses a two-stage venous catheter with a reinforcing member around the blood drainage openings. The reinforcing member is made of a harder stiffer material than the rest of the catheter. The reinforcing member is preferably incorporated in the body of the catheter. The reinforcing member is wrapped in strips around an initial layer of plastisol. A second layer of plastisol is applied to the reinforcing member. Holes are then punched through the reinforcing member and through the layers of plastisol.
SUMMARY OF THE INVENTION
A two-staged venous cannula is disclosed. The cannula has a bullet-shaped tip having side access ports to allow blood to enter the interior of the cannula through the side access ports. An enlarged atrial basket is placed a distance from the tip. The atrial basket has a series of slotted openings allowing blood to flow through the slotted openings into the interior of the cannula.
The cannula includes an expandable reinforcing member around the atrial basket that prevents the cannula from kinking or collapsing in the area where the reinforcing member is applied. The reinforcing member preferably consists of an even number of discrete beams of the same length equally spaced about the circumference of a cylinder. In an alternate embodiment, the beams may be equally spaced on the surface of a cone.
In either embodiment, one end of each beam is attached to the clockwise adjacent beam and the other end of the beam is attached to the counterclockwise adjacent beam thereby forming a device that is cylindrical or conical in shape. Alternate spaces between the beams are created that are open on opposite ends. The alternate space, between the beams are preferably equally spaced around the circumference of the cylinder or the surface of a cone.
A key feature of this reinforcing member is the tendency of the alternate spaces between the beams to remain equally spaced around the circumference of a cylinder car surface of a cone as the reinforcing member is expanded over a larger diameter.
Another advantage of this design for the reinforcing member is that it provides space between the reinforcing member material where holes of the preferred shape, size and orientation can be placed through the cannula without requiring cutting through the relatively rigid material of the reinforcing member. This results in cleaner holes with fewer burrs and in longer punch life.
A further advantage of this design for the reinforcing member is that it provides a combination of expandability and rigidity due to the shape of the reinforcing member, that is, long slot-like spaces between the beams with alternating open ends.
The two-stage venous cannula is made of a flexible material for most of its length so that the cannula may be easily inserted into the patient's heart through the superior vena cave. However, around the slotted openings at the atrial basket where blood flows into the cannula, the reinforcing member prevents kinking or collapsing of the cannula during normal use.
It is therefore an object of the present invention to provide a two-stage venous cannula that is flexible enough to be easily inserted into a patient's heart through the atrial appendage.
It is another object of the invention to provide a two-stage venous cannula that resists kinking and collapse during normal use, especially around the blood inlets to the cannula at the atrial basket.
It is a further object of the invention to provide a two-stage venous cannula with a reinforcing member that maintains the equal spacing between the beams of the member as the reinforcing member is expanded over a larger diameter.
It is another object of the invention to provide a two-stage venous cannula with a reinforcing member with spaces between the material of the reinforcing member so that holes of the preferred shape, size and orientation can be placed through the cannula without requiring cutting through the material of the reinforcing member.
It is another object of the invention to provide a two-stage venous cannula made by a process that results in cleaner holes for the blood to enter the cannula through with fewer burrs and that results in longer punch life for the machine punching the holes in the cannula.
These and other objects and advantages of the invention will be clear from the description contained herein and more particularly with reference to the following detailed description of the invention with its accompanying reference to the attached drawings. Throughout the description, like elements are referred to with like reference numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the two-staged venous cannula of the present invention.
FIG. 2 is a close-up side elevational view of the distal bullet-shaped tip of the cannula of FIG. 1.
FIG. 3 is a close-up side elevational view of the atrial basket area of the cannula of FIG. 1.
FIG. 4 is a side elevational view of the reinforcing member of the cannula of FIG. 1.
FIG. 5 is a top view of the reinforcing member of FIG. 4.
FIG. 6a-FIG. 6e are side elevational views showing the method of making the cannula according to FIG. 1.
FIG. 7 is a perspective view of an alternate embodiment of the reinforcing member of FIG. 4.
FIG. 8 is a perspective view of an alternate embodiment of the reinforcing member of FIG. 4.
FIG. 9 is a perspective view of another alternate embodiment of the reinforcing member of FIG. 4.
FIG. 10 is a perspective view of an alternate embodiment of the reinforcing member of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a two-staged venous cannula according to the present invention, generally labeled 2. Cannula 2 has a distal end 4 and a proximal end 6 and an atrial basket area 8. Cannula 2 is comprised primarily of elongated tubular body 10 having, an interior lumen 12 shown in phantom in FIG. 1. Interior lumen 12 extends from the proximal end 6 to the distal end 4 of cannula 2. Interior lumen 12 is open at the proximal end 6 to allow cannula 2 to be connected to an extra-corporeal cardiac bypass system. However, interior lumen 12 is essentially closed at distal end 4.
A series of holes 14, shown in detail in FIG. 2, are formed near the distal end 4 of cannula 2. The area of distal end 4 containing holes 14 is shown in FIG. 1 generally labeled "A". Holes 14 extend from the outside of the distal end 4 to the lumen 12 of cannula 2. In use, distal end 4 is preferably placed through the heart into the inferior vena cava slightly above the hepatic vein. Holes 14 provide openings to allow blood to pass from the inferior vena cava to the lumen 12. The blood in lumen 12 then flows through cannula 2 to exit cannula 2 through proximal end 6 to ultimately enter an extra-corporeal cardiac bypass system.
In the preferred embodiment, holes 14 are elongated and have the axis of elongation aligned with lines that are parallel to the elongated axis of cannula 2. In addition, holes 14 are preferable equally spaced around the outer surface of cannula 2 at distal end 4. Holes 14 may also be placed in several rows, each row spaced a different distance from the ultimate distal end of distal end 4.
Where multiple holes 14 are provided, it may be preferable to alternate holes 14 in spacing around the outer surface of distal end 4 so that holes 14 in one row are offset from the holes 14 in another row. This arrangement forms a more rigid distal end 4.
Cannula 2 in the area of A preferably has a narrower outer diameter than the rest of cannula 2 to allow distal tip 4 to be placed in the inferior vena cava. In the preferred embodiment, the outer diameter of cannula 2 in area A is about 0.420 inches. In addition, the ultimate distal end of distal end 4 is preferable formed in a rounded or "bullet-shaped" configuration as shown in FIG. 2. This allows for easier insertion of cannula 2 into the patient's inferior vena cava. Cannula 2 in the inferior vena cava prevents the inferior vena cava from kinking while the heart is manipulated during cardiac surgery.
An area of cannula 2 generally labeled "B" in FIG. 1 extends proximally from the proximal end of area A. In the preferred embodiment, a spring 16 is added to the cannula 2 in area B to make cannula 2 in area B more rigid and kink resistant. Spring 16 is preferably a helical wire having a diameter of about 0.015 inch. Spring 16 is preferably integrally formed in cannula 2 at area B as described hereafter.
Because spring 16 is added to area B, the outer diameter of cannula 2 in area, B is slightly larger than the outer diameter of cannula 2 in area A. In the preferred embodiment, this outer diameter of cannula 2 in area B is about 0.450 inches. In addition, the combined length of areas A and B should be such that when the atrial basket 8 is in the center of the right atrium, the distal tip 4 will be in the inferior vena cava slightly above the hepatic vein.
Although in the preferred embodiment, the outer diameter of cannula 2 in area B is slightly larger than the outer diameter of cannula 2 in area A, this is not required to be so. It is within the scope of the invention that the outer diameter of cannula 2 in area B may be equal to or less than the outer diameter of cannula 2 in area A. Further, area B may be made more rigid and kink resistant by means other than spring 16. These means include, but are not limited to adding a stiffening layer to cannula 2 in area B and adding cross-linking agents to the plastisol that forms area B as will be described hereafter.
An area generally labeled "D" extends proximally from the proximal end of atrial basket 8. The outer diameter of cannula 2 in area D is preferably larger than the outer diameter of cannula 2 in area B. In the preferred embodiment, this larger diameter of cannula 2 in area D is about equal to about 0.600 inches.
A transition area from area B to the atrial basket 8 is shown in FIG. 1 generally labeled "C." Area C extends proximally from the proximal end of area B to the distal end of the atrial basket 8. Cannula 2 in transition area C expands from the outer diameter of cannula 2 at the proximal end of area B to the enlarged diameter of cannula 2 at the atrial basket 8. The purpose of transition area C is to allow cannula 2 to acquire a diameter in areas A and B that allows the distal end 4 to move into the inferior vena cava. The length of transition area C is preferably about 0.600 inches.
At atrial basket 8, holes 18 are placed through cannula 2 allowing blood outside of cannula 2 to pass through holes 18 into the interior lumen 12. When cannula 2 is in position so that the distal tip 4 is in the inferior vena cava, the atrial basket 8 will be located in the center of the atrium. Consequently, blood entering the atrial basket through holes 18 will be blood in the right atrium from the superior and inferior vena cava. So, holes 18 drain blood from the right atrium into the cannula 2 and consequently into the extra-corporeal cardiac bypass system.
In the preferred embodiment, holes 18 are equally spaced around the outer circumference of cannula 2 at atrial basket 8. Further, in the preferred embodiment holes 18 are preferably elongated to allow greater flow area for the blood entering the cannula 2 through holes 18. Holes 18 are preferably elongated in the direction of elongation of cannula 2.
A reinforcing member 20 is integrally formed in the atrial basket 8 so that holes 18 pass through reinforcing member 20. A preferred embodiment of reinforcing member 20 is shown in detail in FIGS. 3, 4 and 5.
As can be seen in FIG. 4, reinforcing member 20 has an alternating series of parallel beams 22. Each beam 22 is connected to its neighbor beam 22 by a connecting piece 24. Each connecting piece 24 is attached to only two neighboring beams 22. Further, connecting pieces 24 alternately connect neighboring beams 22 at opposite ends of reinforcing member 20.
In FIGS. 4 and 5, connecting pieces on the distal end of reinforcing member 20 are labeled 24b while connecting pieces on the proximal end are labeled 24a. In this way, a continuous "path" is formed by following a beam 22 to a connecting piece 24a, to a neighboring beam 22, to a connecting piece 24b, to the next neighboring connecting piece 24a, to a connecting piece 24b and so on until returning to the starting point. Spaces 26 are formed between neighboring beams 22.
As can be seen in FIG. 5, reinforcing member 20 is preferably circular in cross-section with lumen 12 passing through the interior of reinforcing member 20 when in position at the atrial basket 8. Reinforcing member 20 is preferably integrally added to cannula 2 as described hereafter. In the preferred embodiment, there are six beams 22. In this preferred embodiment, there are then three each connecting pieces 24a and 24b.
In the preferred embodiment of cannula 2, a spring 28 or other means is added to cannula 2 in area D to make cannula 2 in area D more rigid and kink resistant. Spring 28, like spring 16, is preferably a helical wire having a diameter of about 0.015 inch. Spring 28 is preferably integrally formed in area D as will be described hereafter.
Although in the preferred embodiment the outer diameter of cannula 2 in area D includes a stiffening spring 28, this is not required to be so. It is within the scope of the invention that area D may be made more rigid and kink resistant by means other than spring 28. These means include, but are not limited to adding a stiffening layer to cannula 2 in area D and adding cross-linking agents to the plastisol that forms area D as will be described hereafter.
In an alternate embodiment of reinforcing member 20, a series of parallel beams 22 are formed as before. However, in this alternate embodiment, all connecting pieces 24 are located at the same end of reinforcing member 20. Connecting pieces 24 may be discrete or may be a single integral piece. In either embodiment, spaces 26 are formed having an open end opposite connecting pieces 24. In this alternate embodiment, an even or odd number of beams 22 may be provided extending away from connecting pieces 24.
Reinforcing member 20, shown in FIG. 4 and FIG. 5, is the preferred embodiment for reinforcing member 20. As can be seen, reinforcing member 20 in this preferred embodiment has six beams 22 and six corresponding connecting pieces 24. Although six beams 22 and six corresponding connecting pieces 24 is the preferred embodiment, the invention anticipates that other numbers of beams 22 and connecting pieces 24 can be used.
Additional alternate embodiments of reinforcing member 20 are shown in FIGS. 7 through 9. The alternate embodiments of FIGS. 7 through 9 show reinforcing member 20 having two, four and eight beams 22 and corresponding connecting pieces 24, respectively. It is clear that additional numbers of beams 22 and connecting pieces 24 can be used as desired. In the preferred embodiment, an even number of beams 22 and connecting pieces 24 is required.
In the embodiment of FIG. 7, one connecting piece 24a and one connecting piece 24b is used. In the embodiment of FIG. 8, two connecting pieces 24a and two connecting pieces 24b are used. In the embodiment of FIG. 9, four connecting pieces 24a and four connecting pieces 24b are used. In all ways other than the number of beams 22, connecting pieces 24a and connecting pieces 24b, the reinforcing members 20 shown in FIGS. 7 through 9 are identical to the reinforcing member 20 of the preferred embodiment.
Reinforcing member 20 is preferably made of a material having the properties of being rigid and withstanding the curing temperature of plastisol without becoming soft and compliant. The reinforcing member must be rigid enough to prevent the cannula from kinking or collapsing during normal use. However, the reinforcing member should be flexible enough to accommodate variations in the individual molding pieces and variations encountered during the manufacturing process. Preferred materials include, but are not limited to, polyolefin materials and polyetherimide. Also preferred are rigid polyvinylchloride (PVC) materials that will fuse with the plastisol.
FIG. 10 shows an alternate embodiment of the preferred embodiment and the embodiments of FIGS. 7 through 9. In this alternate embodiment, the material of reinforcing member 20 is a rigid metal wire. Reinforcing member 20 still has the beams 22 and connecting pieces 24a and 24b as before, but reinforcing member is formed by bending or molding the wire into the desired configuration of beams 22 and connecting pieces 24a,b.
As stated above, reinforcing member 20, in whatever embodiment, is preferably integrally formed in cannula 2. FIG. 6a through FIG. 6e show a preferred method for integrally forming reinforcing member 20 in cannula 2.
FIG. 6a shows a metal mold 38 having an outer shape formed in the desired shape of the interior lumen 12. As can be seen, mold 38 has the shape that increases in outer diameter from distal end of 4 to the proximal end 6 of cannula 2 corresponding to the increasing outer diameters of areas A through D as described above.
As shown in FIG. 6b, mold 38 is coated with a first layer of plastisol 40. This first layer of plastisol 40 is preferably deposited on metal mold 38 by dipping metal mold 38 in a vat of plastisol. The plastisol is preferably at room temperature. Thereafter, mold 38 is heated, as is well understood in the art, to set the plastisol.
Reinforcing member 20 is placed over the first layer of plastisol 40 at the distal end of area D (FIG. 6c). Spring 16 is placed over the first layer of plastisol 40 at the proximal end of area B and over area C. Spring 16 extends proximally to approximately abut reinforcing member 20. Spring 28 is placed over the first layer of plastisol in areas D proximal to reinforcing member 20. Spring 28 extends proximally from the proximal end of reinforcing member 20.
A second layer of plastisol 42 is applied to the cannula 2, thereby coating springs 16, 28 and reinforcing member 20 (FIG. 6d). The mold is heated again, as is well understood in the art, until both layers of plastisol 40, 42 are fully cured and fused together. Springs 16, 28 and reinforcing member 20 are thereby encapsulated in the wall of cannula 2. In the preferred embodiment, plastisol material, formed by both layers of plastisol 40, 42, is formed in spaces 26 between beams 22. In alternate embodiments, plastisol material, formed by both layers of plastisol 40, 42, is formed in holes 32 or holes 36.
Cannula 2 is removed from mold 38 by techniques which are understood in the art including but not limited to air assisted blow off.
Holes 18 are punched through spaces 26 in reinforcing members 16 (FIG. 6e). In this way, holes 18 are formed through both layers of plastisol 40, 42 and allow blood access from the outside of cannula 2 to the interior lumen 12. The punches punching holes 18 in cannula 2 have only to punch through the layers of plastisol 40, 42 which are relatively more compliant than the relatively more rigid material of reinforcing member 20.
In the method described above, two layers of plastisol 40, 42 are applied to the cannula 2. However, it is possible to use only a single layer of plastisol, either 40 or 42, in the cannula. In the embodiment having only a first layer of plastisol 40, the method of forming a cannula 2 has the following steps. First, a mold 38 is provided having an outer shape formed in the desired shape of an interior lumen. The mold 38 is coated with a first layer of plastisol 40 and is then heated to set the first layer of plastisol 40. A reinforcing member 20 is placed over the first layer of plastisol 40 at a distance proximal to the distal end of the mold 38. The reinforcing member 20 preferably has at least one space 26 formed therethrough. The mold 38 is then reheated to fuse and embed the reinforcing member 38 in the plastisol. The cannula 2 is removed from the mold 38. A hole 18 is then punched through the first layer of plastisol 40 through the space 26 in the reinforcing member 20.
In the embodiment having only a single layer of plastisol that corresponds to the second layer of plastisol 42 in the preferred embodiment, the method of forming a cannula has the following steps. First, a mold 38 is provided having an outer shape formed in the desired shape of an interior lumen. A reinforcing member 20 is placed over the mold 38 at a distance proximal to the distal end of the mold 38. The reinforcing member 20 preferably has at least one space 26 formed therethrough. Mold 38 is coated with a layer of plastisol 42 to coat the mold 38 and the reinforcing member 20. Mold 38 is heated to set the layer of plastisol 42 over the mold 38 and the reinforcing member 20 and to bond and fuse reinforcing member 20 to the plastisol. The cannula 2 is removed from the mold 38. A hole 18 is then punched through the layer of plastisol 42 through the space 26 in the reinforcing member 20.
When practicing either of the embodiments having only a single layer of plastisol, all other elements, functions and methods are the same as is described above in connection with the preferred embodiment.
The invention has been shown and described in connection with specific embodiments. It is to be realized, however, that the description given herein is for the purpose of illustrating the invention and is not intended to be limiting. It is further understood that improvements and modifications to the disclosure made herein will occur to those skilled in the art and that such improvements and modifications will still fall within the scope of the invention. | A two-staged venous cannula is disclosed. The cannula includes an expandable reinforcing member around the atrial basket that prevents the cannula from kinking or collapsing in the area where the reinforcing member is applied. The reinforcing member preferably consists of an even number of rigid discrete beams of the same length equally spaced about the circumference of a cylinder. In an alternate embodiment, the beams may be equally spaced on the surface of a cone. Alternate spaces between the beams are formed. The alternate spaces between the beams are equally spaced around the circumference of the cannula. The alternate spaces between the beams remain equally spaced around the circumference of the cannula as the reinforcing member is expanded over a larger diameter. This design for the reinforcing member provides space between the beams where holes of the preferred shape, size and orientation can be placed through the cannula without requiring cutting through the material of the reinforcing member. | 0 |
This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 60/304,111 entitled COUPLING OF MODIFIED CYCLODEXTRINS TO FIBERS and filed on Jul. 11, 2001, the entire content of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The invention relates to odour regulation in tissue and hygiene products using modified compounds capable of absorbing odorous components from liquids and of releasing odour-regulating compounds.
BACKGROUND OF THE INVENTION
It is known from JP-A-1-015049 to add cyclodextrins to paper diapers for the purpose of deodorizing the paper diaper. A fragrance is included in the cyclodextrin and can be released in the diaper, while absorption of malodours by the non-included cyclodextrin adds to the deodorizixg effect. Similarly, WO 94/22501 describes articles containing cyclodextrin having a particle size below 12 μm, especially below 5 μm, for removal of odour from diapers and paper towels. On the other hand, cyclodextrin particles of greater than 12 μm, typically around 100 μm, are said to be effective for odour control in absorbent articles according to WO 99/06078. WO 00/66187 discloses odour-controlled superabsorbent polymers containing cyclodextrins or cyclodextrin ethers such a methyl- or hydroxyalkyl-cyclodextrins homogeneously distributed therein.
WO 01/48025 discloses the incorporation of non-derivatized cyclodextrin onto cellulose fibres by covalent bonding of the cyclodextrin using a polymeric anionic reagent such as polymaleic acid or by binding the cyclodextrin to dialdehyde groups on the cellulose.
While cyclodextrins have been known for a long time as being useful for inclusion of a variety of agents, including odour-regulating agents, the most important member thereof, β-cyclodextrin, has a poor solubility and hence a difficult applicability in various product types, such as hygiene products.
SUMMARY OF THE INVENTION
It was found according to the invention, that the utility of cyclodextrins for absorbing various compounds from liquids into solid supports, especially paper and other cellulosic and/or fibrous carriers, can be improved by coupling the cyclodextrins to the solid support. It was also found that, e.g. in hygiene products for use in contact with the human skin, the immobilisation of the cyclodextrins avoids their migration to the skin or, in other uses, to other materials. The coupling can be performed either by ionic interaction, which was found to be easily realized, or by specific covalent bonding.
DESCRIPTION OF THE INVENTION
The carrier: The carrier to which cyclodextrin and other encapsulating agents with or without inclusion compounds can be coupled has a fibrous structure and is substantially water-insoluble. It is usually a polymer having a partial or full polysaccharide nature, such as in cellulose, hemicellulose or synthetic carbohydrates. The molecular weight of the carrier is preferably above 5 kDa; more preferably from 100 kDa to 10 MDa. Lower molecular weights are also feasible, as long as the polysaccharide is water-insoluble. The polymer may be natural or synthetic, and may be a mixture of various polymer types, such as cellulose-acrylate, or starch-acrylate, or starch-protein and the like. The fibrous structure is preferably part of an absorbent product, for use in absorbing fluids such as washing fluids, body fluids and the like. Examples include paper and paper products, tissues and the like, especially for use in hygiene products, such as such as kitchen rolls, facial tissues, bathroom towels, sanitary napkins and diapers.
The encapsulating agent: These are products that are capable of complexing or encapsulating molecules of interest, such as biologically active agents (drugs, biocides, attractants, repellants, diagnostic agents, regulators, etc,), odours, fragrances, and the like, for the purpose of absorption or slow release. These primarily include cyclodextrins, i.e, cyclooligomers of anhydroglucose units (AGU), having at least 6 AGU (α-cyclodextrin), preferably 7 AGU (β-cyclodextrin), possibly 8 (γ-cyclodextrin) or more AGU (δ- and higher cyclodextrins). Furthermore, acyclic analogues having complexing and/or encapsulating capacities, such as helical oligoglucoses (α-1,4: dextrins, or β-1,3) can also be coupled and used according to the invention. The encapsulating agents, especially cyclodextrins, are used in ionic form.
In this context, oligo- means having up to 20 recurrent units. The cyclodextrins and analogues may be unmodified or modified, e.g. by acylation, alkylation, hydroxyalkylation, etc., apart from any modification that would be necessary in the coupling process, as detailed below. The encapsulating agents are referred to below as cyclodextrins (CD) for the sake of simplicity, but it should understood that the analogous agents as described here are always covered as well, unless they are explicitly excluded.
Ionic coupling: Ionic coupling of CD to fibrous carriers can be effected by applying an electronic charge on the carrier and by applying the opposite charge to the CD. For example, the carrier can be negatively charged (anionic derivatisation) by carboxyalkylation, sulphonation, phosphorylation and the like, using chloroacetic acid, chloroethanesulphonic acid or vinyl sulphonic acid, phosphoric acid or its chloride, and the like, respectively. A mixed anionic derivatisation can be achieved e.g by addition of maleic anhydride, followed by addition of bisulphite, resulting in anionic groups of the type: —O—CO—CH—CH(SO 3 H)—COOH (or its deprotonated forms). Alternatively, anionic derivatisation can be achieved by oxidizing the carrier carbohydrate to a slight extent. The CD can then be made cationic as described in more detail below, and then be combined with the anionic carrier.
Alternatively, and more preferably, the carrier can be positively charged (cationic derivatisation) by amino- or azido-alkylation, or oxidation to introduce aldehyde functions followed by reaction with amines (reductive amination) or other nitrogen-containing reagenats. Cationisation of the carrier can also be achieved by applying a cationic additive such as PAE (poly(amide)amine-epichlorohydrin) to the carrier. The anionic or cationic derivatisation is performed to an extent that allows sufficient coupling of oppositely charged, and depending on the particular use of the coupling product. In general, a degree of ionisation of 0.1-50 ionic charges per 100 monomer units of the carrier, preferably from 1 to 20 charges per 100 units.
Cationic charges can be introduced into CD molecules in a manner known per se. Suitable methods include reaction of CD with chloroethyl-trimethylammonium chloride or glycidyl trimethylammonium chloride or similar reagents, resulting in quaternary ammoniumalkyl derivatives. These have a full positive charge irrespective of the pH of the system in which the coupling products ions incorporated. Alternatively, the lower substituted aminoalkyl derivative can be prepared, which are suitable for use in neutral and acidic conditions. Amine or ammonia groups can also be introduced into CD by first introducing aldehyde functions, either by periodate oxidation, or by TEMPO-mediated oxidation using hypochlorite or a peracid, as described e.g. in WO 95/07303, WO 99/57158, WO 00/50388 and WO 00/50621, followed by reaction with an amine, preferably under reducing conditions. One cationic charge per CD molecule is generally sufficient for coupling. Preferably the CD will have a DS (degree of substitution) for cationic groups between 0.1 and 0.3, most preferably 0.17-0.25 for α-cyclodextrins, 0.14-0.22 for β-cyclodextrins, and 0.12-0.2 for γ- and higher cyclodextrins.
Anionic charges can be also introduced onto CD molecules in a manner known per se. Suitable methods therefore include oxidation of CD with e.g. periodate, followed by chlorite, or by direct oxidation with hypochlorite, resulting in one or more glucose units being opened to dicarboxy-oxabutylene [—O—CH(COOH)—CH(CH 2 OH)—O—CH(COOH)—] units, or with periodate, followed by oxidation with peracetic acid and bromine, as described in WO 00/26257, resulting in similar ring-opened units with both aldehyde and carboxyl groups. Anionic derivatisation of CD can also be effected by carboxyalkylation, sulphonation, phosphorylation and the like, as explained above for anionisation of the carrier. A further anionic CD derivative is a hydroxytriazinyl derivative, obtainable by reaction of CD with trichloro-s-triazine.
Preferably however, the oxidation is focussed on the 6-hydroxymethyl groups, using hypochlorite or persulphuric acid and nitroxyl-mediation, e.g. using TEMPO or 4-acetamido-TEMPO, as mentioned above. Again, the resulting DS for anionic charges in preferably between 0.1 and 0.3, more preferably 0.17-0.25 for α-cyclodextrins, 0.14-0.22 for β-cyclodextrins, and 0.12-0.2 for γ- and higher cyclodextrins.
Another method for coupling involves derivatisation of the CD with a group that will smoothly react with hydroxyl functions of the carrier. A suitable example of such derivatisation is reaction with a halotriazine.
Utility: The products of the invention are especially useful as an odour regulator in hygiene products, such as diapers, napkins and tissue products such as wipes for kitchen rolls and facial tissues, bathroom towels etc., by scavenging malodours. They can also assist in suppressing bacterial growth, resulting in reduced ammonia production e.g. in diapers and panty liners. The amount of complexing or encapsulating oligosaccharide on the fibrous carrier can be an amount varying between 1 and 300 mg/g, preferably between 1 and 200 mg/g and most preferably between 1 and 100 mg/g. The odour regulation can be effected in two ways. Firstly, the oxidized cyclodextrins serve to absorb odorous components from the fluid or solid material for which the hygiene material is used, such as sulphur compounds, amines, aromatic compounds, carbonyl compounds and the like. Secondly, a desired neutralizing odour or fragrance may be incorporated in the product prior to its use, and can be released or exchanged in use, resulting in a neutral and/or, pleasant odour in the product in use. Examples of suitable fragrances include terpenoid compounds such as linalool, menthone, menthol, limonene and pinene.
Other applications are in the pharmaceutical and medical field, or in biocides, for odour control, stabilisation of encapsulated compounds to light, oxidation and vaporisation, slow release, and in enantiomer separation.
EXAMPLE 1
Ionic Binding
Coupling of 6-carboxy β-cyclodextrin to Cationic Fibres
6-Carboxy β-cyclodextrin was prepared by oxidation of β-cyclodextrin with 4-acetamido-TEMPO and hypochlorite. Thus, 7.64 g β-cyclodextrin, 150 mg NaBr and 150 mg 4-acetamido TEMPO were added to 300 ml water. Sodium hypochlorite was added in doses of 0.20 ml. During reaction the pH was kept at 9.3 by addition of NaOH controlled by a pH stat. After each dose the reaction was allowed to proceed until no further NaOH consumption was seen. Two samples were prepared with a degree of oxidation (DO) of 0.11 and 0.38, respectively.
Cationic fibres were prepared by oxidation of sulphate pulp fibres (SCA {hacek over (O)}strand mill) with sodium periodate (DO=10% dialdehyde) and the obtained aldehyde groups were subsequently reacted with Girard's reagent T (acethydrazide trimethylammonium chloride). Hereby fibres containing 10% cationic groups were obtained.
Next 30 mg of 6-carboxy β-cyclodextrin (acidic form) was dissolved in 5 ml de-mineralized water and added to 1 g (dry weight) of cationic fibres containing ca, 60% water. The fibres were incubated at 120° C. for about 1 hour. Afterwards the sample was washed with 200 ml de-mineralized water to remove non-bound oxidized cyclodextrin and dried in a fluidized bed dryer for 30 minutes at 60° C. (Samples I and II).
EXAMPLE 2
Ionic Binding
Coupling of Carboxymethylated β-cyclodextrin to Cationic Fibres
Carboxymethylated β-cyclodextrin was prepared by reaction with monochloroacetic acid at pH 12. The product obtained had a degree of substitution of 0.36. The cationic fibres were prepared as described in Example 1.
30 mg of carboxymethyl β-cyclodextrins were adsorbed on 1 g cationic fibres (dry weight), and washed with water and dried, as described in Example 1 (Sample III).
EXAMPLE 3
Ionic Binding
Coupling of Monochlorotriazinyl β-cyclodextrin to Cationic Fibres
Cationic fibres were prepared by adding 5 g fibres to a solution containing 0.5 g PAE (poly(amide)amine-epichlorohydrin). This mixture was incubated overnight at room temperature. Next excess liquid was removed and the fibres were dried at 120° C. Finally, non-bound PAE was removed by washing the fibres.
Then, 30 mg monochlorotriazinyl β-cyclodextrin ((MCT-CD) obtained from Wacker Chemie) was dissolved in 20 ml demineralized water and added to 1 g (dry weight) cationic fibres. This mixture was allowed to stand at room temperature for 20 minutes, resulting in ionic bonding (Sample IV). Non-bound MCT-CD was removed by washing the fibres with de-mineralized water. Next the fibres were dried for 10 minutes at 80° C. in a fluidized bed dryer, which does not result in covalent coupling. As covalent coupling requires temperatures in the order of 140-175° C. (as described by Reuscher and Hirsenkorn in Journal of Inclusion Phenomena and Molecular Recognition in Chemistry , 25 (1996) p. 195), it is assumed that at these mild conditions of drying, 10 minutes at 80° C., no chemical reaction between the fibres and MCT-CD occurs.
EXAMPLE 4
Covalent Bonding
Coupling of Carboxymethyl-β-cyclodextrin to Pulp Fibres
Carboxymethyl β-cyclodextrin, prepared as described above, was (250 mg) was reacted with wet 1.66 g pulp fibres (dry weight 1 g) for 1.5 hours at 150° C. After reaction the fibres were washed with water to remove non-reacted carboxymethyl β-cyclodextrin (sample V).
EXAMPLE 5
Covalent Bonding
Coupling of Monochlorotriazinyl-β-cyclodextrin to Pulp Fibres
30 mg monochlorotriazinyl β-cyclodextrin (obtained from Wacker Chemie) was dissolved in 5 ml 250 mM Na 2 CO 3 pH 11 and added to 1 g (dry weight) sulphate pulp fibres containing about 60% water. The sample was incubated at 120° C. for about 1 hour and afterwards suspended in 200 ml demineralized water to remove non-reacted cyclodextrin. Finally, the fibres were dried in a fluidized bed dryer for 30 minutes at 60° C. (sample VI).
EXAMPLE 6
Measuring Binding Capacity of Cyclodextrinated Fibres
The binding capacity of the modified fibres was determined colorimetrically, 2 ml of 20 mg/l phenolphthalein solution in 100 mM Na 2 CO 3 buffer pH 10.3 was added to 1 g of dry modified fibres. Next the liquid was squeezed out of the fibres and absorption of the solution was measured at 554 nm. The results are summarized in Table 1. The lower the absorption in the squeezed solution, the more phenolphthalein has been encapsulated by the cyclodextrinated fibres. Table 1 shows that the difference in absorption between the samples and their blanks is considerably bigger when ionically bound CD, carboxymethyl CD (Sample III) and MCT-CD (Sample IV), is compared to covalent bound CD, (Sample V and VI).
TABLE 1
Phenolphthalein binding ability of fibres treated with cyclodextrin
derivatives
Absorption
Sample
Description
at 554 nm
starting solution
1.580
catiopic (Girard reagent T) fibres (blank)
0.484
I
ionically bound 6-carboxy β-cyclodextrin,
0.343
DO 0.11
II
ionically bound 6-carboxy β-cyclodextrin,
0.314
DO 0.38
III
ionically bound 6-carboxymethyl β-cyclodextrin,
0.146
DS 0.36
cationic (PAE) fibres (blank)
1.120
IV
ionically bound MCT-CD-β-cyclodextrin
0.076
pulp fibres (blank)
0.678
V
covalently bound carboxymethyl β-cyclodextrin
0.454
VI
covalently bound monochlorotriazinyl
0.063
β-cyclodextrin
EXAMPLE 7
Absorption Test with Ionically Bound MCT-CD Tissues
The ability of a cyclodextrin-containing tissue to remove a hydrophobic agent was shown visually by spreading an amount of phenolphthalein on a smooth surface, and attempting to remove the phenolphthalein using untreated tissue and tissue containing monochlorotriazinyl β-cyclodextrins (MCT-CD).
For each test a smooth surface (10 cm×10 cm) was polluted by spreading a phenolphthalein solution (20 μmol phenolphthalein) in ethanol on it. Next the ethanol was evaporated, and thus a layer of dry phenolphthalein was obtained.
A cyclodextrin-containing tissue (11×11 cm) was prepared by adding an MCT-CD solution in water (containing approximately 100 μmol MCT-CD) to a tissue that has cationic charge (treated with excess PAE) and next drying it in a fluidized bed dryer at 80° C. for 15 minutes. Before wiping the surface, each tissue was wetted with 5 ml of 1 M Na 2 CO 3 buffer, pH 10.3 (convert phenolphthalein to its pink form). Next the surfaces were wiped until as much of the phenolphthalein as possible was removed. After wiping, the untreated tissue had completely turned dark pink, and it appeared that is was not possible to completely clean the surface, since the tissue was releasing excess of phenolphthalein. However, the surface cleaned by the MCT-CD containing tissue was completely clean, and the tissue showed some light pink spots, but was overall white. | Cyclodextrins and other ecapsulating oligosaccharides can be bound to fibrous and/or polysaccharidic carriers by ionic bonds. The ionic bonds can be produced by introducing cationic or anionic groups into the cyclodextrins, and where appropriate, by introducing oppositely charged groups in the carrier material. The products can be used for odor control in the fibrous material. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to a process for the separation of a butene mixture to produce an n-butene rich product and an isobutylene rich product in a fractionator wherein the reflux is isomerized before introduction into the fractionator. The resulting high purity streams and isobutene are useful in subsequent reactions to produce secondary butyl alcohol and methyl ethyl ketone from normal butylene and butyl rubber and lubricating oil additive from isobutylene.
The isomerization of olefins is generally well known in the petroleum refining art. The double bond present in olefinic hydrocarbons shift readily over various catalysts to a more central position in the organic molecule. Composites of a metal from Group VIII of the Periodic Table properly inhibited in their hydrogenation activity with a refractory inorganic oxide as well known catalysts in producing olefinic bond migration.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an economical method for isomerizing, and separating butene isomers via a novel fractionation and reaction process. In a broad embodiment, the present invention relates to a process for separating isoolefins and normal olefins from a mixture thereof which comprises the steps of: (a) separating said mixture into a first stream rich in normal olefins and a second stream rich in isoolefins in a fractionation zone; (b) reacting said second stream in an olefin isomerization zone; (c) returning at least a portion of the effluent from said isomerization zone to said fractionation zone as a reflux stream; (d) recovering at least a portion of the effluent from said isomerization zone as an isoolefin product stream; and (e) recovering a normal olefin product stream from said fractionation zone.
Another embodiment of the present invention relates to a process for producing isobutylene from a mixture containing normal butenes and isobutylene which comprises the steps of: (a) separating said mixture into a first stream rich in cis-2-butene and trans-2-butene and a second stream rich in isobutylene contaminated with 1-butene in a fractionation zone; (b) reacting said second stream in an olefin isomerization zone; (c) returning at least a portion of the effluent from said isomerization zone to said fractionation zone as a reflux stream; (d) recovering at least a portion of the effluent from said isomerization zone as an isobutylene product stream; and (e) recovering a normal butene product stream from said fractionation zone.
The normal boiling point of 1-butene is about 20° F. and the normal boiling point of isobutylene is about 19.6° F. These boiling points are quite close together, so that separating 1-butene from isobutylene by conventional fractionation is impractical. The normal boiling points of cis- and trans-2-butene are about 38.7° F. and 33.6° F., respectively, so that isobutylene and 1-butene can be separated from 2-butene by fractionation. Such a separation, however, is not capable of providing a high purity isobutylene stream, substantially free from 1-butene. By employing the method herein disclosed, 1-butene can be significantly reduced from an isobutylene product stream. Therefore, a high purity isobutylene product stream may be provided from a conventional source of butene isomer mixture.
Further objects, embodiments and illustrations indicative of the broad scope of the present invention will be apparent to those skilled in the art from the description of the drawing and preferred embodiments of the invention hereinafter provided.
DESCRIPTION OF THE DRAWING
The attached drawing is a schematic flow diagram and illustrates a particular embodiment of the present invention. Referring to the drawing, a conventional butylene feed, comprising 44 weight percent 1-butene, 44 weight percent isobutylene and 12 weight percent 2-butene, is charged through conduit 1 and hydrogen is charged through conduit 2. The combined butylene feed and hydrogen is passed via conduit 1 into reaction zone 3 which is maintained at olefin isomerization conditions. The hydrocarbons charged to reaction zone 3 are contacted with a fixed bed of an isomerization catalyst comprising nickel and sulfur on a porous carrier; the catalyst being prepared by forming an initial composite of the nickel carrier material, sulfiding and then stripping sulfur from the catalyst with hydrogen to provide a final isomerization catalyst. This catalyst hereafter being called a nickel subsulfide catalyst. The hydrocarbons are passed continuously through reaction zone 3 at a liquid hourly space velocity (volume of charge per volume of catalyst per hour) of about 0.1 to about 20, preferably in downward flow over the catalyst bed, and continuously withdrawn from reaction zone 3 through conduit 4. The isomerization reactor effluent in conduit 4 is charged to fractionator 5, which is conventional fractionation vessel. The isomerization reactor effluent has a reduced level of 1-butene with an essentially corresponding increased level of cis-2-butene and trans-2-butene. Because of a thermodynamic equilibrium constraint the 1-butene level will be at least five to fifteen percent of the normal butene fraction. In fractionator 5, a mixture of isobutylene and 1;L -butene is separated and withdrawn overhead through conduit 6. The mixture of hydrocarbons in conduit 6 passes to reaction zone 7 which is maintained at olefin isomerization conditions. The hydrocarbons charged to reaction zone 7 are contracted with a fixed bed of an isomerization catalyst comprising a nickel subsulfide catalytic material. The resulting isomerized hydrocarbons are continuously withdrawn from reaction zone 7 via conduit 8. At least a portion of said resulting isomerized hydrocarbons is returned via conduits 8 and 10 to fractionator 5 as reflux. The remainder of said resulting isomerized hydrocarbons is recovered via conduits 8 and 9 as an isobutylene product stream. Various conventional equipment and operations have not been described in the foregoing, such as pumps, valves, heat exchange means, etc. The use of such conventional equipment and operations will be understood to be essential and the method of their use in the process of the present invention will be obvious to those skilled in the art.
DETAILED DESCRIPTION OF THE INVENTION
The olefinic feedstock containing 1-butene, 2-butene and isobutylene employed in the present process may comprise solely butene isomers, or may contain other hydrocarbons. It is contemplated that the olefinic feed employed normally comprises a mixture of 1-butene, 2-butene and isobutylene. However, other materials may be present in olefin feedstock, including for example, paraffins, naphthenes or aromatics, as well as minor amounts of contaminants. A suitable olefinic feedstock may contain some propane, normal butane, isobutane, pentane, butadiene, etc. which hydrocarbons are often present in minor amounts in a conventional olefinic feedstock source. It is preferred, however, that the olefinic feedstock employed in the present process contain at least about 50 weight percent C 4 olefins.
The olefinic feedstock in the process of the present invention may first be contacted with an isomerization catalyst in an isomerization reaction zone at olefin isomerization conditions. Isomerization catalysts which can be employed in the isomerization operation of the present invention include catalysts which produce a shift of the olefinic bond in 1-butene to a more central position in the hydrocarbon molecules to form 2-butene. Various catalysts have been found suitable in prior art, including, for example, alumina, silica, zirconia, chromium oxide, boron oxide, thoria, magnesia, aluminum sulfate and combinations of two or more of the foregoing. Also employed have been acidic catalysts such as sulfuric acid, phosphoric acid, aluminum chloride, etc. either in solution or on a solid support. Also suitable for use in the isomerization operation as an isomerization catalyst is a sulfided nickel on porous carrier material such as described in U.S. Pat. No. 3,821,123. Thermal isomerization may be utilized, but suffers from the defects of producing excessive amounts of side products.
The preferred method by which the operation of the isomerization step of the present process may be effected in a continuous-type operation. One particular method is a fixed bed operation in which the feedstream comprising butene isomers is continuously charged to an isomerization reaction zone containing a fixed bed of catalyst, the reaction zone being maintained at olefin isomerization conditions including a temperature in the range from about 0° to about 400° F. or more, and a pressure of about 1 atmosphere to about 200 atmospheres or more. A preferred temperature is about 80° to about 300° F. and a preferred pressure is about 4 atmospheres to about 50 atmospheres. The charge of butene isomers is passed over the catalyst bed in either an upward or downward flow and withdrawn continuously and recovered. It is contemplated within the scope of the present invention that gases such as hydrogen, nitrogen, etc., may be continuously charged to the isomerization zone as desired.
Another continuous-type operation comprises a moving bed-type in which the butene isomers feed and the catalyst bed move co-currently or countercurrently to each other while passing through the isomerization zone.
Alternate but less efficient methods of achieving the same separations and product qualities are available. As an example, a system could be constructed employing the same reaction zone 3 and fractionator 5 illustrated in the drawing but with a second reaction zone on the net materials from the overhead of fractionation zone 5 and a second fractionation zone. For the same product qualities, however, more energy would be required because of the need for the second fractionation zone than required using the present invention.
Conventional sources of C 4 olefins contain a mixture of 1-butene, 2-butene and isobutylene. Although various attempts have been made in prior art to isomerize 1-butene by shifting the olefinic bond to provide 2-butene, it has been found, in general, that olefin isomerization conditions which favor economically desirable high conversion of 1-butene also tend to favor polymerization of isobutylene, a highly undesirable side reaction. Prior art has thus been limited to lower than optimum conditions of 1-butene to 2-butene when isobutylene is present in the feed stream to the isomerization operation. The process of the present invention at least partially overcomes the problems thereby created. In the present process, it is not necessary to maintain olefin isomerization conditions such that an extremely high conversion of 1-butene is achieved, so that polymerization of isobutylene is thereby avoided. At the same time, by charging the fractiontor overhead vapors containing 1-butene and isobutylene directly to an isomerization reaction zone and then refluxing at least a portion of the isomerized overhead to the fractionator, the concentration of 1-butene in the net overhead isobutylene product stream is significantly reduced. Other suitable olefins may be selected from pentenes, hexenes, etc.
The process of the present invention is further illustrated by the following examples. These examples are, however, not present to unduly limit the process of this invention, but to further illustrate the hereinabove described embodiments.
EXAMPLE I
A standard, conventional distillation column is charged with 10,000 mols per day of a mixed butene stream having the characteristics displayed in Table I.
TABLE I______________________________________ Overhead Bottoms Feed Product Product______________________________________1-Butene, mols 650 588 62Isobutylene, mols 3500 3250 250cis-2-Butene, mols 2925 6 2919trans-2-Butene, mols 2925 36 2889______________________________________
The distillation column contains at least 80 theoretical stages and is refluxed at about 80,000 mols/day. Inspections of the overhead and bottoms products are shown in Table I and indicate that the isobutylene overhead stream has a purity of 84% and that the 2-butene bottoms stream has a purity of 96%.
EXAMPLE II
The identical distillation column used in Example I is modified by incorporating an olefin isomerization reaction zone in the column's overhead vapor line. The feed to the above-described column as modified is charged with 10,000 mols per day of a mixed butene stream having the same characteristics as the Example I feed and displayed in Table II.
TABLE II______________________________________ Overhead Bottoms Feed Product Product______________________________________1-Butene, mols 650 26 44Isobutylene, mols 3500 3241 259cis-2-Butene, mols 2925 94 3147trans-2-Butene, mols 2925 141 3048______________________________________
Inspections of the overhead and bottoms products are shown in Table II and indicate that the isobutylene overhead stream has a purity of 93% and that the 2-butene bottoms stream has a purity of 96%.
From the foregoing examples, the beneficial import of the process of this invention is readily ascertainable by those skilled in the art. | A butene mixture is separated to yield an n-butene rich product and an isobutylene rich product in a fractionator system. The fractionator reflux is isomerized before introduction into the fractionator. Other suitable olefins may be separated in a similar manner. | 2 |
This application is a continuation of Ser. No. 08/425,144 filed Apr. 19, 1995 (abandoned), which is a Divisional application of Ser. No. 08/004,848 filed Jan. 19, 1993 (abandoned).
FIELD OF THE INVENTION
The present invention relates to biological testing and in particular to methods for identifying several classes of genetic defects that contribute to hypercholesterolemic conditions, and to reagents and test kits for performing such methods.
BACKGROUND OF THE INVENTION
Genetic hypercholesterolemia, which predisposes an individual to atherosclerosis, is a condition characterized by an abnormally elevated serum cholesterol level, wherein excessive dietary intake is not the sole cause of the elevation. Instead, the condition is caused by single or multiple autosomal mutations which affect either (i) the expression of lipoprotein receptors on the cell surface, or (ii) the capability of surface receptors to bind the apoprotein component of various lipoprotein particles. The nature of the mutation influences the patient's predisposition to respond to various classes of lipoprotein-lowering drugs. Such patients are currently identifiable by a failure to respond to diet therapy and by the commonality of certain abnormal characteristics among family members. Insofar as is known, no direct clinical diagnostic is currently available to positively identify the condition. Because of the need for this type of clinical information, several research tests have been used to elucidate the physiological mechanisms underlying the hypercholesterolemic patient's condition.
Research has focused on the identification of abnormal lipoprotein receptors, and has been concerned primarily with low density lipoprotein (LDL) receptors, which are thought to be most important in the predisposition for atherosclerosis. These methods have relied on genetic analysis of cells, comparing symptomatic and asymptomatic individuals. The receptor-coding DNA is subjected to restriction fragmentation and analysis, to identify genetic polymorphisms relating to abnormalities in lipoprotein receptors. See Japanese Patent Application No. 2291300 to Seiyaku (1990); PCT Application No. WO 88/03175 to Frossard (1988). Although genetic polymorphism analysis provides detailed information concerning genetic abnormalities which may be present, several points should be considered. First, not all genetic mutations manifest themselves as an impairment of the functioning of lipoprotein receptors or as an abnormality of the apoprotein region of the lipoprotein particle. Some mutations may be "quiet" mutations, whereby a nucleotide or amino acid substitution has no effect on the functionality of the resultant gene product. Secondly, although genetic techniques prove useful in the research laboratory, they are not generally applicable to use in the clinical laboratory because of the technical degree of difficulty and the sophistication of equipment that is required. Moreover, some mutations cannot be recognized through restriction enzyme analysis.
Alternative techniques have focused on assessing the functional aspect of the lipoprotein receptors, particularly LDL receptors. Radioactively labelled LDL particles (e.g., 125 I-labelled protein components of the LDL particle) or LDL particles into which a fluorescent marker had been incorporated, have been utilized to determine differences between the number of LDL receptors on fibroblasts of genetically normal and abnormal individuals. Goldstein et al., J. Biol. Chem., 258: 4526-33 (1974). Polyclonal and monoclonal antibody methods have also been developed for the assessment of LDL receptor activity. Beisirgel et al., J. Biol. Chem., 257: 11923-31 (1981). Such antibodies have been utilized on whole cells using fluorescence or enzyme signal detection methods, and have also been applied to immunoblot analysis of various tissue extracts. Beisirgel et al., J. Biol. Chem., 257: 13150-56 (1982).
Lymphocytes from peripheral blood have been used to study the LDL receptor status in patients. Most of these studies have been disappointing due to the high uptake of LDL by peripheral blood monocytes in uninduced mononuclear samples, combined with the low receptor activity of lymphocytes due to receptor suppression by native serum lipoproteins. Ho et al., J. Clin. Invest., 58: 1465-74 (1976). Incubation for periods of 36 hours or more have greatly enhanced the receptor expression of these cells.
Although both radioactive methods and fluorescent methods can be used for determinations of LDL receptors on cell surfaces, fluorescent methods provide distinct advantages for clinical laboratory settings. Fluorescently labelled lipoprotein, detectable by flow cytometry and fluorometry, have been disclosed. In particular, the fluorescent compound 1,1'-dioctadecyl-2,2,2',2'-tetramethylindocarbocyanine perchlorate (DiI)-labelled human LDL particles have been used to measure surface binding and internalization into isolated lymphocytes at 37° C. The fluorometric methods were reported as being more signal-sensitive, but problematic since non-specific monocyte signals could not be eliminated from the analysis. Although less signal-sensitive, flow cytometric methods provided the advantage of being able to utilize light-scattering properties of the various cell subsets (e.g., monocytes, lymphocytes and neutrophils) to exclude the undesired monocyte and neutrophil populations from the analysis. Wojciechowski et al., Biochem. Soc. Trans., 15: 251-52 (1987). Further developments in this area have involved utilizing fluorescent labelled porcine LDL having a reportedly higher affinity for human LDL receptors than the previously-used human LDL, combined with methods to overcome the problem of repression of LDL receptors in fresh lymphocyte samples, as well as methods to evaluate receptor metabolism. These methodologies have also employed flow cytometry as the detection system. See, e.g., WO 91/06011 to Abel et al. (1991).
Clinical application of fluorescent techniques requiring flow cytometry for detection is problematic because of the low sensitivity as well as the inherent difficulties associated with flow cytometric analysis. Flow cytometry has become widely used in the clinical laboratory in analysis of white blood cell subsets, using monoclonal antibodies. But even under the standard protocols developed for such analyses, great inconsistencies can arise in test results due to the subjectivity of the analysis using flow cytometric methods. LDL receptor analysis histograms generated by flow cytometry are generally even more subjective. This combination of difficult analysis and expensive and technically demanding instrumentation renders clinical implementation of flow cytometry for LDL receptor analysis undesirable, if not completely unpracticable due to the high-volume multiple sample testing which would be required. Thus, there is considerable need for a clinically applicable method of identifying and analyzing potentially abnormal lipoprotein metabolism in a patient suspected of having genetically based hypercholesterolemia.
SUMMARY OF THE INVENTION
In accordance with the present invention, clinically applicable methods are provided for identifying and analyzing potentially abnormal lipoprotein metabolism in a patient. These methods can be practiced in batch mode, on multiple samples, using simple protocols and inexpensive instrumentation. It will be appreciated that the methods described hereinbelow may be utilized to assay the binding and internalization capability of any cell surface receptor. However, the invention will be described with specific reference to lipoprotein receptor determination. Exemplification on the basis of lipoprotein receptors should not be considered to limit the invention in any way.
According to one aspect of the invention, a method is provided for determining the relative number per cell of a pre-determined receptor (e.g., lipoprotein receptor) associated with a cell subset of interest in a test sample containing a mixed cell population, the subset of interest having at least one characteristic determinant. In a preferred embodiment, the test sample consists of a sample of whole blood from a patient, and the cell subsets of interest are lymphocyte populations.
According to the method, the cells comprising the subset of interest are uniformly labelled with a detectable reporter substance. The test sample comprising the cells is also contacted with a receptor-selective marker, which binds specifically to the pre-determined lipoprotein receptor, thus rendering the receptor detectable. Thus, the cell subset of interest contains two detectable labels: (1) a uniform label which can be used to quantitate the number of cells of interest in the test sample; (2) a receptor-selective label, which is used to quantitate the number of pre-determined lipoprotein receptors in the test sample. The test sample is then contacted with a specific binding substance which binds specifically to at least one characteristic determinant of the cell subset of interest, thereby forming a complex between the cell subset of interest and the specific binding substance. The complex comprising the specific binding substance and the cell subset of interest is separable from the other components of the test sample. In a preferred embodiment, the specific binding substance is affixed to a solid phase, such as a magnetic bead, so that the complex may easily be separated from other components of the test sample (e.g., by magnetic separation).
After the cell subset of interest is separated from the other components of the test sample, the amount of detectable reporter substance and the amount of receptor-selective marker are detected. A ratio of the amount of receptor-selective marker to the amount of detectable reporter substance is established to determine the relative number of lipoprotein receptors per cell in the cell subset of interest.
According to another aspect of the invention, the above-described method may be used to assess the functional metabolic capacity of a pre-determined lipoprotein receptor associated with a cell subset of interest in a test sample comprising a mixed cell population containing that subset of interest. A test sample comprising the cell subset of interest is labelled, such that substantially all cells of the subset of interest are uniformly labelled with a detectable reporter substance so that they can be enumerated. Each of two aliquots is then contacted with a receptor-selective marker which is binds specifically to the pre-determined lipoprotein receptors, thereby rendering those receptors detectable. The first aliquot of the test sample is maintained under conditions which substantially inhibit metabolic activity of the pre-determined lipoprotein receptors associated with the cell subset of interest. The second aliquot of the test sample is maintained under conditions which substantially optimize the metabolic activity of those lipoprotein receptors. Each aliquot is then contacted with a specific binding substance which binds specifically to at least one characteristic determinant of the cell subset of interest, thus forming a complex between the cell subset of interest and the specific binding substance. The complex is then separated from the other components of each aliquot, and the relative number of receptors per cell in each aliquot is determined by: (1) detecting the amount of detectable reporter substance, (2) detecting the amount of receptor-selective marker, and (3) determining the ratio of receptor-selective marker to detectable reporter substance. In a preferred embodiment, the detectable reporter substance is separated from the cells in the separated complex before the measurement of the detectable reporter substance is made.
The metabolic capacity of the lipoprotein receptors is then assessed by establishing a ratio of the relative number of lipoprotein receptors per cell in the aliquot maintained under non-metabolic conditions to the aliquot maintained under optimal metabolic conditions.
According to another aspect of the invention, a method is provided for determining the presence of abnormalities in the apoprotein component of a lipoprotein in a test sample. In particular, the method is applicable to abnormalities affecting the ability of the lipoprotein to interact normally with its cognate lipoprotein receptor. According to this method, there is provided a detectable lipoprotein binding reagent, which has binding sites that bind specifically to the apoprotein component of the lipoprotein. There is also provided a labelled lipoprotein standard which reproducibly binds to the lipoprotein binding reagent. The labelled lipoprotein standard may comprise a lipoprotein or the apoprotein of a lipoprotein. A test sample is obtained, which is suspected of having an abnormally binding lipoprotein (due to an abnormality in the apoprotein component), and a dilution series of assay samples is prepared. Each assay sample comprises, in a fixed total volume, (1) a fixed amount of the lipoprotein binding reagent, (2) a fixed amount of the labelled lipoprotein standard and (3) a fixed volume of the test sample or a dilution thereof. The fixed amount of labelled lipoprotein standard, combined with the lipoprotein present in the test sample, should slightly exceed the approximate amount needed to occupy all of the binding sites of the lipoprotein binding reagent.
The assay samples are incubated under conditions suitable to permit binding of the labelled lipoprotein standard and lipoprotein present in the test sample to the lipoprotein binding reagent. The basis of the assay is competition between the labelled apolipoprotein standard and the lipoprotein of the test sample. If the patient's lipoprotein are capable of binding normally to binding sites on the lipoprotein binding reagent, they will be able to compete better with the labelled lipoprotein standard for binding sites. If the patient has impaired lipoprotein binding capability, his lipoprotein will be less able to compete for binding sites on the lipoprotein binding reagent.
Each assay sample is then contacted with a specific binding substance capable of binding specifically to a characteristic determinant of the lipoprotein binding reagent, under conditions causing binding of the specific substance to the lipoprotein binding reagent. Thus, a complex between the specific binding substance and the lipoprotein binding reagent is formed, and the complex can be separated from other components in each assay sample.
The amount of lipoprotein binding reagent in each assay sample is quantitated by measuring the detectable label incorporated therein. The amount of labelled lipoprotein standard associated with the lipoprotein binding reagent in each assay sample is also measured, and the relative amount of labelled lipoprotein standard per fixed amount of lipoprotein binding reagent is determined. This ratio represents the fraction of those binding sites occupied by the labelled apolipoprotein standard in each assay sample, and is inversely proportional to the fraction of binding sites occupied by the patient's lipoprotein in the test sample. Thus, the ability of the lipoprotein in the test sample to bind to its cognate lipoprotein receptor may be assessed. This assessment is further facilitated by comparing a test sample from a patient suspected of having lipoprotein with abnormal binding capabilities to a test sample from an individual known to have lipoprotein of normal binding capabilities.
According to yet another aspect of the present invention, a method is provided for making a receptor-selective marker, which may be used advantageously in the practice of the present invention. The receptor-selective marker comprises a lipoprotein particle and a stably-associated detectable moiety, and is capable of binding specifically to a pre-determined lipoprotein receptor, thereby detectably labelling that receptor. The preparative method involves providing, e.g., by isolation and purification from a natural source, lipoprotein particles that bind selectively to the pre-determined lipoprotein receptor. After purification, such particles are suspended in a buffer comprising a fairly high concentration of a salt (e.g., 150 mM NaCl). The lipoprotein particles are then transferred to a labelling diluent which is capable of maintaining the functionality of the lipoprotein particles, while optimizing the stable association of the detectable moiety with the lipoprotein particles. The detectable moiety is chosen for its ability to become stably associated with the lipoprotein particles. According to a preferred embodiment, the labelling diluent consists essentially of a biologically compatible non-ionic buffer capable of regulating the osmolarity of the diluent to between about 250-350 mOs. Following transfer into the labelling diluent, the lipoprotein particles are contacted with the detectable moiety, thereby forming a receptor-selective marker which comprises a lipoprotein particle and a stably associated detectable moiety.
According to further aspects of the present invention, test kits are provided for carrying out the assays of the invention. A kit is also provided for preparing a receptor-selective label, according to methods of the present invention.
The present invention eliminates the need for the subjectivity of flow cytometric analysis and reduces the requirement for high cost instrumentation, such as a flow cytometer, allowing the use of low cost instrumentation, such as fluorescence-based multiwell plate readers. These new assay methods also provide for simultaneous processing of multiple patient samples, which is a marked advantage, especially in high volume clinical laboratories, over the sequential processing inherent in flow cytometry.
DETAILED DESCRIPTION
The present invention provides methods for detecting several genetic mutations which result in functional impairment of various stages of lipoprotein metabolism. Although this description focuses on lipoprotein metabolism, it will be appreciated that many metabolic functions involving binding of substances to cell surface receptors, followed by internalization of the bound substance, may be examined using the methods of the invention.
In one aspect of the invention, methods are provided to identify individuals having genetic mutations which result in reduced expression of lipoprotein receptors on cell surfaces. Expression of lipoprotein receptors on cell surfaces is necessary for the binding of lipoprotein particles for clearance and metabolism. In another aspect of the invention, methods are provided to assess internalization of bound lipoprotein, which is also essential for lipoprotein clearance and metabolism. Still another aspect of the invention involves methods for identifying individuals having mutations in the lipoprotein which result in the impairment of binding of lipoprotein to their cognate receptors. Such an impairment of binding often results from a mutation affecting the protein structure of the apoprotein portion of the lipoprotein. In another aspect of the invention, methods for preparing detectably labelled lipoprotein are provided.
A. Reagents and Components for Practice of the Invention
The term "lipoprotein", as used herein, refers to particles such as High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL), Chylomicrons (CM), Very Low Density Lipoprotein (VLDL) and Intermediate Density Lipoprotein (IDL). The role of these lipoprotein is to assist in the processing or transport of free cholesterol, cholesterol esters and triglycerides. They are generally composed of phospholipids and proteins, along with the cholesterol or triglyceride moieties. The protein moiety of a lipoprotein is referred to as an "apoprotein". The apoprotein of LDL is known as "ApoB".
"Lipoprotein receptor" as used herein refers to functional domains on various cell types, such as blood cells or liver cells, which interact and bind specifically with a lipoprotein particle, such as those enumerated above. A lipoprotein receptor that is specifically recognized for binding by a particular lipoprotein particle (e.g., LDL) is sometimes referred to herein as the "cognate receptor" of that lipoprotein particle. For purposes of the present invention, the term "lipoprotein receptor" also refers to artificially created molecules, such as antibodies, capable of specifically interacting with and binding the lipoprotein particles.
For purposes of the present invention, the term "cells" is also intended to include other bioparticles capable of being assayed by the method of the present invention, but not necessarily comprising viable cells. The cells or bioparticles of interest may be present in test samples or specimens of varying natural or synthetic origin, including biological fluids such as whole blood, serum, plasma, urine, cerebrospinal fluid, amniotic fluid, lavage fluids and tissue extracts. In a preferred embodiment, the test sample is whole blood.
The analysis of lipoprotein receptor status is performed on cell suspensions or populations including subpopulations and subsets expressing a characteristic determinant. The term "determinant" is used herein in its broad sense to denote an element that identifies or determines the nature of something. When used in reference to the methods of the invention, "determinant" means that portion of the cell involved in and responsible for selective binding to a specific binding substance or detectable reporter substance, the presence of which is required for selective binding to occur. In general, naturally-occurring determinants are used in the methods of the invention. In one embodiment, however, a sample may be treated with an antigenic substance capable of stably associating with surface membranes of a cell subset of interest, thereby creating an artificial determinant on the cell subset of interest.
The term "specific binding", as used herein, means binding of one moiety to another, to the substantial exclusion of other moieties. For example, an antibody that binds specifically to a cell surface determinant binds substantially exclusively to that determinant, and not to any substantial extent to other determinants on the cell surface.
Cell-associated determinants include, for example, components of the cell membrane, such as membrane-bound proteins or glycoproteins, including cell surface antigens (also referred to herein as epitopes) of either host cell or viral origin, histocompatibility antigens, or membrane receptors. One class of specific binding substances used to selectively interact with these determinants are antibodies capable of immunospecifically recognizing antigens. The term "antibody" as used herein includes monoclonal or polyclonal antibodies immunoglobulins and immunoreactive immunoglobulin fragments. Further examples of characteristic determinants and their specific binding substances are: receptor--hormone, receptor--ligand, agonist--antagonist, Fc receptor of IgG--Protein A, avidin--biotin, virus--receptor and lectin-receptor. These are sometimes referred to herein as "specific binding pairs".
The practice of the present invention involves the selection of a cell type on which the measurement for lipoprotein receptor expression can be carried out. Though, traditionally, lipoprotein receptor deficiencies have been conducted on skin fibroblasts or hepatocytes, these sources do not permit an easily obtainable sample for routine testing. In a preferred embodiment, whole blood is used as the sample. For the receptor number and function assay, two criteria are important: 1) to select the cells or subsets of cells which possess the greatest potential for binding the lipoprotein particle of interest while being present in high enough frequency to provide a strong signal to noise ratio and 2) to select the cell subset of interest with the greatest reproduciblity and potential for internalization or processing of the lipoprotein particles such that normal and abnormal receptor functioning will be easily distinguishable. In a preferred embodiment, lymphocytes, preferably the CD4 or CD3 subsets, are utilized to provide maximal performance with regard to both criteria. Monocyte or neutrophil subsets are not preferred in the practice of this invention since they possess scavenger receptors for lipoprotein particles. These scavenger receptors non-specifically bind lipoprotein particles and will not provide a clear indication of the patient's potential for normal lipoprotein processing.
In the practice of the invention, quantification of the number of lipoprotein receptors present on cells or bioparticles in a test sample is carried out in part using a receptor-selective marker. The term "receptor-selective marker" is defined as a substance capable of binding specifically to a pre-determined lipoprotein receptor and providing an intense signal of sufficient intensity that it can be used to quantitate the amount of said substance bound. The amount of receptor-selective marker bound relates directly to the number of pre-determined lipoprotein receptors present in the sample. The receptor-selective marker may contain, for example, a naturally-occurring lipoprotein particle, (e.g., LDL) or apoprotein (the protein constituent of a lipoprotein particle which confers specificity for a given receptor type). Alternatively, it may be a specific binding protein or peptide, or an organic molecule such as a monoclonal or polyclonal antibody that binds to a specific lipoprotein receptor domain. The signal-generating component of the receptor-selective marker (also referred to herein as the "detectable moiety") may comprise a molecule, macromolecule or ion bound to or partitioned with the receptor-selective portion of the substance, and being capable of being detected. Suitable molecules include fluorescent dyes, adsorbent dyes, radioisotopes or molecules capable of reacting with a second reagent to produce a detectable signal, e.g., molecules with enzymatic activity which can convert a nondetectable substrate into a detectable product. A method for preparing labelled lipoprotein particles for use as receptor-selective markers is set forth in greater detail below.
In the practice of the present invention, the receptor-selective marker is reacted with a sample containing lipoprotein receptors under reagent-excess conditions, to allow complete saturation of all available lipoprotein receptor sites, after which any unbound substance is removed from the sample by washing.
To assay test samples in batch mode rather than single cell analysis mode, a second signal is required which can be used to quantitate the number of cells or particles containing the lipoprotein receptors to be analyzed. The use of this second signal ensures that any differences in the quantity of receptor-selective marker observed is due to an actual modification or alteration in lipoprotein receptor expression levels, rather than to a variation in the number of cells or particles being measured. This second signal, herein referred to as a "detectable reporter substance" should be a molecule, macromolecule or ion capable of directly generating a signal, or capable of reacting with a secondary component which is able to generate a signal. The signal-generating component of the detectable reporter substance may be detected by absorbance, fluorescence, radioactivity or enzymatic activity resulting in the formation of a detectable product. In a preferred embodiment, the detectable reporter substance should be detectable by the same means as the receptor-selective marker. The detectable reporter substance must be capable of uniformly labeling the cells of the test sample, or all cells of a given subset of interest in a mixed cell population, such that a linear relationship exists between the signal generated by the detectable reporter substance and the number of cells of interest in the sample.
The detectable reporter substance may uniformly label the cell subset of interest by coupling to a uniformly-expressed determinant on the surfaces of the cells, in such a way as to avoid interfering with subsequent binding steps of the invention. Coupling of the detectable reporter substance to cell surfaces may be achieved by a variety of methods. In a preferred embodiment, the detectable reporter substance is bound to an antibody which itself binds specifically to at least one uniformly-expressed determinant of the cells of interest. Monoclonal antibodies to particular cell surface determinants are used to great advantage in this embodiment. For example, lymphocytes, which comprise a subpopulation of whole blood and have a high expression of lipoprotein receptors, may be uniformly labelled with a reporter substance bound to a monoclonal antibody which is directed against a lymphocyte surface antigen (e.g., CD2, CD3, CD4, CD5).
In another embodiment, the detectable reporter substance is attached to one member of a specific binding pair (e.g., avidin), while the other member of the specific binding pair (e.g., biotin) is attached to a monoclonal antibody specific for a selected cell surface antigen. Coupling of the detectable reporter substance is accomplished by immunospecific binding of the antibody to the cell surface antigen, combined with binding of the members of the specific binding pair to one another. In a preferred embodiment, the attachment of the biotin to the antibody is made in such a way that the linkage may be cleaved under appropriate conditions, thereby liberating the detectable reporter substance from the cell subset of interest. Such linkage methods are known in the art.
As an alternative to surface coupling, another aspect of the invention involves uniform labelling whereby the detectable reporter substance enters and becomes internalized within cells. In a preferred embodiment, the detectable reporter substance comprises a compound capable of entering viable cells, undergoing hydrolysis by intracellular enzymes, the hydrolyzed product being capable of detection by means of fluorescence. The detectable hydrolyzed product remains within the cells during separation of subsets of interest, and can be measured upon extraction from separated complexes. A particularly useful compound for this embodiment is 2'7-bis(2-carboxyethyl)-5-(and-6)carboxyfluorescein, acetoxymethyl ester (BCECF-AM), which is hydrolyzed intracellularly to 2',7'-bis (carboxyethyl)-5-(and 6) carboxyfluorescein (BCECF). Other useful compounds include:
1-[2-amino-5-(6-carboxyindol-2-yl)-phenoxyl]-2-(2'-amino-5'-methylphenoxy)ethane-N,N,',N'-tetracetic acid, pentaacetoxymethylester;
3-acetoxy-5'(and 6')-acetoxymethoxycarbonyl-10-dimethylaminospiro[7H-benzo[c]xanthene-7,1'(3'H) -isobenzofuran]-3'-one;
fluorescein diacetate; and
5-(and-6)-carboxyfluorescein diacetate.
In another alternative, the detectable reporter substance may be uniformly incorporated into the cell population or subset of interest by becoming internalized within the cells and binding to some internal cellular component, such as nucleic acid. In a preferred embodiment, stains capable of binding to the DNA or RNA in the nucleus of the cell are utilized. For example, Hoescht nuclear stains may be used to advantage in the practice of the present invention.
In a preferred embodiment of the present invention, the detectable reporter substance and/or the receptor-selective marker, or the detectable portions thereof, are separated from the cell subset of interest prior to being quantitatively measured. This step is particularly important when fluorescent compounds comprise the detectable portions of said reporter substance and label, to increase the signal potential and minimize quenching that may occur due to enhanced label incorporation into the reporter substance. Separation of the detectable reporter substance and/or receptor-selective marker may be accomplished by many methods known in the art, e.g., by solubilization with a detergent, or partitioning of a non-polar compound into a suitable organic solvent.
A method for separating cells or cell subsets is also required for the practice of the invention to facilitate washing of the samples and to expedite sample processing time. A specific binding substance and a solid support are the reagents used for this purpose. The term "specific binding substance" as used herein is defined as a molecule or macromolecule which is capable of interacting selectively with a characteristic determinant of the cells, or subset of cells, present in the test sample. The specific binding substance may be a monoclonal or polyclonal antibody, for example, with reactivity toward a unique CD-antigen present on the cell surface (e.g., CD3 or CD5). Alternatively, the specific binding substance may comprise magnetic or paramagnetic particles capable of being ingested by a selected cell subset (e.g., iron particle phagocytosis by macrophages). Additionally, the specific binding substance may comprise macromolecules capable of being reacted with or inserted into the membrane of cells; such macromolecules artificially acting as unique antigens (e.g., compounds of Formula I, discussed hereinbelow). The specificity of the specific binding substance should be unique in that there should be no appreciable cross-reactivity or interference with binding or incorporation of the receptor-selective marker.
The solid support enables the cells of interest to be separated from the other cells in the sample. The term "solid support" as used herein refers to a particulate or solid matrix having characteristics which allow it, or a compound attached to it, to react with the specific binding substance. The solid support to which the specific binding substance is affixed should be easily separable from the cell sample. Alternatively, the solid support should be fixed such that the unbound constituents in the sample may be washed away from it. Examples of solid supports may be, but are not limited to, magnetic or paramagnetic plates, beads or particles, high density particles made of materials such as polystyrene or latex with high sedimentation coefficients, immobile supports such as porous isolation columns, nylon or nitrocellulose membranes or plastic immobile supports, such as polymer plates or dishes (e.g., 96-well ELISA plates).
In a particularly preferred embodiment of the invention, the specific binding substance is affixed to a magnetic solid phase, which may comprise ferromagnetic, paramagnetic or diamagnetic material, thereby forming complexes or aggregates with the cell subset of interest which are magnetically separable from the test medium. Suitable procedures for coupling specific binding substances to a magnetic solid phase, e.g., magnetite particles, are described in the literature. See, for example, E. Menz et al., Am. Biotech. Lab. (1986).
If the solid support itself is not capable of reacting with the specific binding substance, it will have attached to it a molecule or macromolecule which will be capable of reacting with the specific binding substance so that the specific binding substance becomes affixed to the solid support. Such a molecule or macromolecule is referred to herein as an "auxiliary specific binding substance". For example, a magnetic bead comprising a monoclonal antibody capable of reacting with the specific binding substance, may be utilized. If the specific binding substance comprises an antibody, for example, the solid phase may have affixed to it a second antibody directed toward a characteristic determinant of the first antibody. In one embodiment, the first antibody comprises a selected isotype and the second antibody binds specifically to a determinant of that isotype. In another embodiment, the first antibody comprises immunoglobulin obtained from a selected species and the second antibody binds specifically to a determinant of that immunoglobulin from that species. In another embodiment, the specific binding substance comprises an antibody chemically attached to biotin, and the solid phase is affixed with an auxiliary binding substance comprising avidin. In this embodiment, the biotin may be attached to the antibody by a cleavable linkage, thereby enabling separation of the solid phase from the specifically bound cells of interest, if desired. In another embodiment, the solid support is affixed with a chemical reactive group, e.g., a tosyl group, capable of reacting with a constituent group of the specific binding substance.
Any of the foregoing methods of the invention may utilize various standards to great advantage. Such standards may include, but are not limited to pre-determined amounts of: (1) a detectable reporter substance; (2) receptor-selective marker; (3) cell subsets of interest which have been uniformly labelled with detectable reporter substance; and (4) cell types bearing pre-determined receptors having known affinities for a selected lipoprotein. The use of such standards in assays of the type described herein is common practice in the art.
The methods of the invention may be performed using conventional containers, including test tubes, multiwell plates, and the like. Detectors for accurately measuring the level of reporter substances in a test sample, such as a calorimeter, a spectrophotometer, a fluorospectrophotometer, a reflectometer, a liquid scintillation counter or a gamma counter, are commercially available.
According to another aspect of the invention, pre-measured quantities of the different reagents, together with the various accessories used in practicing the methods of the invention, including diluents, cleaving agents, solid supports, one or more standards, or instructions for the preparation thereof may be conveniently packaged in a test kit. The reagents included in the test kit may take various forms. The receptor-selective label and detectable reporter substance may be provided in the form of solutions, together with suitable diluents. The solutions may be provided in containers suitable for performing the methods of the invention. Alternatively, the reporter substances and other reagents may be packaged dry, together with separate vials of diluent or solvent for addition to the reagents in the course of carrying out the methods. The specific binding substance is preferably provided immobilized on a solid support, which may be suspended in a suitable buffer, lyophilized or dried.
B. Competitive Assay for Determining Apoprotein Binding Affinity
According to another aspect of the present invention, a method is provided for evaluating the ability of a patient's lipoprotein particles to bind to their cognate lipoprotein receptors. Mutations in the structure of the apoprotein portion of the lipoprotein particle can affect this binding ability, resulting in the impairment of lipoprotein metabolism. The basis for the presently claimed assay is competition between a patient's lipoprotein and a labelled lipoprotein standard (or other receptor-selective marker, as described herein), of known binding capabilities, for binding to a known quantity of a lipoprotein binding reagent. The lipoprotein binding reagent may be a cell line with a high expression of the lipoprotein receptor of interest, which can be grown easily in culture to provide a continual source of the reagent. Such cells may be used fresh or they may be preserved in some manner, such that the receptor-lipoprotein binding interaction is maintained. Alternatively, a synthetic lipoprotein binding reagent may be created and employed, an example of which may be a magnetic or latex bead with monoclonal or polyclonal antibodies directed toward the apoprotein of the lipoprotein particle of interest, or a receptor specific for the particle of interest. If a cell line is utilized as the lipoprotein binding reagent, the basic requirement for selection of such a cell line is that it comprises a characteristic determinant by which cells can be enumerated, a characteristic determinant which can be utilized to bind a specific binding substance for cell separation and receptors for the lipoprotein particle of interest.
The assay is conducted by preparing various assay samples containing the lipoprotein binding reagent (which has been uniformly labeled with a detectable reporter substance), a fixed amount of labelled lipoprotein standard and a fixed volume of various dilutions of the lipoprotein of interest from the patient. The patient's lipoprotein is preferably provided as a sample of blood serum. An excess of labelled lipoprotein standard, alone or in combination with the patient's lipoprotein contained in the assay sample, must be used to ensure complete saturation of all the lipoprotein receptors present in the sample. Also, a concentration balance between the labelled lipoprotein standard and the patient's lipoprotein should be maintained, so as to allow for good resolution and signal detection through equilibrium binding. The sample is allowed to incubate, e.g., for at least 2 hours at room temperature to permit equilibrium binding of the labelled lipoprotein standard and of the patient's lipoprotein particles.
After the incubation, the samples are reacted with a specific binding substance affixed to a solid support, thereby separating the lipoprotein binding reagent, and lipoprotein bound thereto, from the assay samples. The lipoprotein binding reagent is enumerated by measuring the amount of detectable reporter substance incorporated therein. The labelled lipoprotein standard is then measured for each assay sample. Results for each sample are expressed as a ratio of the amount of labelled lipoprotein standard to the amount of detectable reporter substance measurement. The ability of a patient's lipoprotein to bind the lipoprotein binding reagent is assessed by comparing the above-described competition assay with a standard competition assay, e.g., using serum having normally-binding lipoprotein.
In a preferred embodiment, a negative control may also be included in the above-described lipoprotein binding assay. A negative control comprises a labelled lipoprotein that reproducibly binds to the lipoprotein binding reagent with a binding affinity approximately the same as that of an abnormal lipoprotein. For example, lipoprotein from serum of non-human species have been found to possess differential binding affinities for a lipoprotein binding reagent designed to bind human lipoprotein. Because these binding affinities are generally reproducible, non-human serum may be used to measure the degree of abnormality of the human lipoprotein being tested. Methods for performing the competitive lipoprotein binding assay are set forth in greater detail in Example 3 below.
C. Preparation of Labelled Lipoprotein Particles to be Used as a Receptor-Selective Marker or Labelled Lipoprotein Standard
As defined previously, the receptor-selective marker is used in the method of the invention to evaluate the expression and/or metabolism of lipoprotein receptors in cells or various subsets of cells. It is also used as a labelled standard to evaluate the binding capability of a patient's lipoprotein to a lipoprotein binding reagent. Another aspect of the present invention relates to a method of preparing labelled lipoprotein particles which can serve as the receptor-selective marker or standard in these assay systems. Lipoprotein particles of interest are isolated using standard isolation techniques such as density centrifugation, ultra centrifugation or tangential flow methods, according to methods known in the art. See, e.g., Harel et al., J. Clin. Invest., 34: 1345-53 (1955); Pritchard et al., Anal. Biochem., 174: 121-22 (1988). Purified lipoprotein particles are then dialyzed against a suitable buffer solution and carried through the labelling process. The labelling process involves the transfer of the lipoprotein particles from traditional dialysis buffers, such as 0.15 M NaCl+0.3 mM EDTA+5 mM HEPES-KOH (pH 7.5) to a suitable diluent which can be used for labelling with a detectable moiety. See Table 1 infra.
For fluorescence labelling, the lipoprotein particles can be rendered fluorescent by the incorporation of a highly aliphatic or lipid soluble fluorochrome into the lipoprotein particles. Examples of such fluorochromes include, but are not limited to, compounds such as 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI), 3,3'-dioctadecyloxacarbocyanine perchlorate (DiO), 3,3'-ditetradecylthiacarbocyanine (DiS), and Acridine long chain dyes. In a preferred embodiment, a membrane-binding compound of formula I shown below is used:
R--B--R.sub.1 I
wherein B represents a detectable substance and R and R 1 represent substituents independently selected from the group of hydrogen, alkyl, alkenyl, alkynyl, alkaryl or aralkyl, the hydrocarbon chains of which are linear or branched, said substituents being unsubstituted or substituted with one or more non-polar functional groups, one of R or R 1 having at least 12 linear carbon atoms and the sum of the linear carbon atoms in R and R 1 totaling at least 23.
Compounds of this formula bind stably to cell surface membranes, or bio-particles having lipid bilayer membranes. A method for preparing a receptor-selective marker comprising a compound of formula I above is set forth in Example 1, below.
Compounds of formula I above preferably comprise a chromophore as the detectable moiety (B). In other preferred embodiments, the detectable moiety comprises a radioactive molecule or a chelating moiety designed to chelate a radioisotopic rare earth metal. In another embodiment, the detectable moiety may comprise a substance that reacts with a second substance to generate a detectable signal, e.g., biotin, which may be reacted with avidin bound to an enzymatic compound capable of generating a detectable product.
In a preferred embodiment, B represents a compound of the formula: ##STR1## wherein X and X 1 may be the same or different and represent O, S, C(CH 3 ) 2 or Se;
Y represents a linking group selected from ═CR 3 --, ═CR 3 --CR 3 ═CR 3 --, ═CR 3 --CR 3 ═CR 3 --CR 3 ═CR 3 --, or ═CR 3 --CR 3 ═CR 3 --CR 3 ═CR 3 --CR 3 ═CR 3 --, wherein R 3 is selected from H, CH 3 , CH 2 CH 3 , CH 2 CH 2 CH 3 or CH(CH 3 ) 2 ;
Z and Z 1 may be the same or different and represent substituents selected from the group H, alkyl, OH, --O-alkyl, CON-(alkyl) 2 , NH-acyl, NH-alkyl, N(alkyl) 2 , NO 2 , halogen, Si(alkyl) 3 , O-Si(alkyl) 3 , Sn(alkyl) 3 or Hg-halogen, the alkyl groups comprising Z and Z 1 substituents having from 1 to 4 carbon atoms; and A represents an anion. Compounds of Formula I and II above are commercially available (Zynaxis Cell Science, Inc., Malvern, Pa.). In particularly preferred embodiments, B represents oxacarbocyanine or indocarbocyanine.
Using any of the detectable moieties described above, the following methodology may be employed to incorporate such molecules into the lipoprotein particles of interest. Incorporation of large amounts of signals per lipoprotein particle will require that the detectable moiety have high solubility characteristics in a diluent capable of maintaining the integrity and affinity of the lipoprotein particles. Salt-based isotonic diluents with osmolarity conditions suitable for lipoprotein particles are not optimal for practice of the labelling method, since they do not permit maintenance of the detectable moiety in monomeric form. Instead, they foster micelle formation, which retards or minimizes incorporation of the detectable moieties into the lipoprotein particles. Other organic diluent solutions, such as heptane, have been employed. However, these often provide a more soluble environment for the detectable moiety than for the lipoprotein particle, thus discouraging selective partitioning of the detectable moiety with the lipoprotein particle. The use of organic diluents such as heptane also commonly involve lyophilization of the lipoprotein sample prior to dissolving lipoprotein in the organic solutions, due to water and organic solution immiscibility. The present invention employs labelling diluents that maintain lipoprotein structure and function, reduce handling and manipulation and allow for a preferential partitioning of the detectable moiety with the lipoprotein particle. Diluents which may be employed successfully include osmolarity-regulating solutions (250-350 mOs) of the following compounds, either singly or in combination:
TABLE 1______________________________________ Relative Fluorescence Intensity (CONC)Osmolarity Regulating Agent DiS-C.sub.14 -(5) DiO-C.sub.14 -(3)______________________________________Ethanol 100 100 Glucose 31 100 Fructose 35 100 Sorbose 40 100 Sucrose 41 100 Xylose 36 19-52 Ribose 24 100 Lyxose 0.12 1.8 Glycine 31 93 Arginine 17 17.2 Glycerol 39 99.5 Inositol 42 92 Xylitol 34 76.4 Mannitol 29 * Adonitol 34 ND Tris(hydroxymethyl)-methylaminopropane 18 ND sulfonic acid (TAPS) 3-(Cyclohexylamino)-1-propanesulfonic acid 40 ND (CAPS) N-(2-Hydroxyethyl)piperazine-N'-3-propane- 18 ND sulfonic acid (EPPS) N-2-hydroxyethyipiperazine-N'-2-hydroxy- 20 ND propane-sulfonic acid (HEPPSO) 3-[N-N-bis(-2-hydroxyethyl)amino]-2- 43*** ND hydroxypropanesulfonic acid (DIPSO) NaCl 6 1.7 Phosphate Buffered Saline 2.1 6.5 Na.sub.2 SO.sub.4 7.4 1.6 NaI 1.1 0.14 Choline Chloride 11** 6.3 Choline Iodide 0.16 2.3______________________________________ *Precipitate in ethanol, no data obtainable **Artifact due to large crystals did not pellet ***Precipitate in ethanol. ND Not determined
While the above list fulfills criteria for maintaining lipoprotein structure and permits selective partitioning of the detectable moiety into the lipoprotein, another factor must be taken into consideration in the practice of the present invention. Lipoproteins may exist in the native non-oxidized form, or they may become oxidized over time under certain conditions. To accurately enumerate selected lipoprotein receptors, non-oxidized lipoprotein should be used to eliminate or minimize general non-specific lipoprotein binding, and interference by scavenger receptors, which will also non-selectively bind the oxidized form of the lipoprotein. Of the complete list of compounds which will provide the desired conditions for partitioning of signal compounds into lipoprotein particles, several promote oxidation while others have been found to minimize it.
TABLE 2______________________________________Lipoprotein Oxidation in Various Diluents LDL SAMPLE UNTREATED BHT TREATED DILUENT EMPLOYED SAMPLE CONTROL______________________________________CHES (Good's Buffer) 1.591 1.036 Glycine 1.026 1.001 Fructose 1.218 1.126 Sucrose 1.146 1.003 Xylitol 1.061 1.046 Glucose 1.479 1.141______________________________________
Table 2 presents measurement of lipoprotein oxidation, utilizing a fluorescence measurement at an excitation wavelength of 360 nm and an emission wavelength of 430 nm, which differentiates oxidized versus non-oxidized LDLs. Non-oxidized controls comprise butylated hydroxytoluene (BHT) added to the lipoprotein solution as an antioxidant. As illustrated in Table 2, although glucose may in fact provide good labelling of lipoprotein particles (Table 1), it also promotes the oxidation of the particle. In contrast, glycine also provides good incorporation of a detectable moiety into the lipoprotein, but oxidation does not occur to any significant degree. Thus, for the method of the present invention, glycine is preferred as a osmolarity-regulating solution for labelling lipoprotein particles. A protocol for labelling low density lipoprotein with a compound of formula I above is set forth in Example 1 below.
Examples 1-3 below illustrate use of the methods and reagents of the present invention for identifying patients as either normal or abnormal with regard to lipoprotein receptor expression, receptor functioning and affinity of the apo-B protein of LDL particles for its cognate lipoprotein receptor. These examples are intended to illustrate and not to limit the invention.
EXAMPLE 1
LABELLING LOW DENSITY LIPOPROTEIN (LDL) WITH A FLUORESCENT MEMBRANE-BINDING COMPOUND OF FORMULA I
A. Lipoprotein Preparation
Freshly isolated (non-oxidized) LDL, not older than 2 weeks, is dialyzed in buffer for at least 48 hours prior to labelling. The buffer consists of 0.15 M NaCl, 0.3 mM EDTA, pH 7.5, supplemented with 5 mM HEPES. Dialysis is carried out at 4° C. under nitrogen if possible, or in buffer flushed with nitrogen. The LDL is then filter-sterilized (0.45 nM filter) to avoid bacterial contamination. The LDL is dialyzed at 4° C. for 48 hours (3 changes of the diluent), preferably under nitrogen, against a labelling diluent (isosmotic, salt free, non-oxidative) in order to remove salts. Glycine or xylitol are suitable diluents since they show the least oxidation potential for LDLs (see Table 2, supra). Even slight salt contamination should be avoided. LDL should be handled under sterile conditions, and antioxidants should be chosen carefully. During isolation of the LDL from the blood, 20 nM BHT, 0.03 mM EDTA, 200 U/L vitamin E, 0.1% reduced glutathione can be used as a mixture for best results, however each component may be used individually. During dialysis however, BHT and vitamin E should be used very carefully if at all, since they can be incorporated into the LDL particle and decrease dye incorporation and affinity to the LDL receptors.
B. Labelling Mixture
A fluorescent membrane-binding compound (hereinafter FMBC) of formula I above is used for labelling isolated LDL. For example, PKH 26-GL is supplied as a 1 mM solution in ethanol from Zynaxis Cell Science, Inc. (Malvern, Pa.). A 1:5 dilution is prepared using an optimal diluent (glycine) providing a 20 μM final solution. Glycine or xylitol is recommended to control oxidation, and serve as the diluents of choice. However, other diluents such as those listed in Table 1 with values >20 will support solubilization of the dye for delivery to the particle, but oxidation potential should be monitored. The amount of LDLs to be labelled will dictate the labelling conditions and column size necessary to isolate the labelled LDL particles from the free unbound dye. The following combinations have proven workable: (1) 2 mls LDL in diluent+2 mls 20 μM FMBC in diluent with use of a 32 cm by 3.5 cm column for isolation; 1 ml LDL in diluent+1 ml 20 μM FMBC in diluent with use of a 37 cm×1.5 cm column for isolation.
Labelling is carried out under the following conditions to label 2 mls of LDL preparation. The steps should be performed as rapidly as possible, in the exact order specified, and preparation of solutions should occur immediately prior to conducting the labelling reaction: Temperatures of 4° C. to 15° C. should be used for labelling.
Prepare the stock solution of FMBC at a 20 μM final concentration in diluent (glycine, pH 7.0, osmolarity of 280-300). Add 50 μl of DMSO (25 ul/100 ul FMBC) to enhance the fluorochrome-to-protein ratio for labelling. Addition of more DMSO will result in overlabelling and inactivation of the LDL particles. Immediately before the addition of LDLs, add 3 ml of 20% Bovine Serum Albumin (BSA; Fraction V) in diluent to the mixture (300 ul/200 ul) of FMBC labelling solution). Fraction V BSA is fatty acid free and has low proteolytic activity, so it serves to protect the LDL particles. The BSA must be added immediately prior to the addition of LDLs, to prevent BSA/dye association. The final concentration may range from 4-10%. A final concentration of less than 4% BSA will result in some denaturation of the LDL particles, while a final concentration of greater than 10% will create difficulties in separation of the LDL particles on the column. The addition of BSA compares well with other labelling methods using serum or starch method, and provides advantages in the final purification steps not found in the serum or starch methods. Immediately add the LDLs in diluent. Proper concentrations are from 1.5 to 3 mg LDL/ml per 100 ul of 1 mM FMBC. The addition of too much LDLs will result in a poor dye/LDL ratio whereas too little will dilute the final product and presents the potential for overlabelling. The recommended labelling time is 15 minutes, not to exceed 30 minutes (prolonged exposure could denature LDL).
C. LDL Separation From the Labelling Mixture
Separation of labelled LDL from the labelling mixture can best be accomplished by gel filtration in Sephacryl S-300 or S-1000 (Pharmacia). Separation may also be accomplished by ultra-centrifugation, however the process requires 3-4 days and may increase the oxidation rate.
The column size should be appropriate to the volume of the labelling mixture. The column should be equilibrated and run with a buffer comprising 0.12 M NaCl, 10 mM Tris-HCl (pH 7.5), 0.3 mM EDTA, 0.01% NaN 3 .
Fractions are collected and analyzed as soon as possible; fraction size depends upon column size (1 or 2 ml). Protein concentration can be assessed by measuring absorbance at 280 nm and FMBC concentration at the peak emission wavelength of FMBC (provided with suppliers' instructions, e.g., for PKH 26-GL, 500 nm). Cholesterol level can be measured with Sigma Kit No. 352 (optional).
The best two or three fractions are pooled and centrifuged for 30 minutes at 4° C., 3000×g and filtered with a 0.45 nM filter. Store in a small, tightly closed container under Nitrogen at 4° C. in the dark. Anti-oxidants may also be added for longer term storage.
The separation procedure should be performed at 4°-15° C., preferably in the dark. Fluorescence intensity per microgram of the protein is measured using a Lab Systems fluoroscan (3,3 setting) and the oxidation level is assessed by measuring fluorescence (1,1 setting) or by Iodine oxidation testing.
Several studies were completed to assess the performance characteristics of material from commercial sources compared with the material produced from the methods of this invention. The results are set forth in Table 3.
TABLE 3______________________________________Comparison of LDL Prepared by the Method of the Invention with Other Commercial Sources OXIDATION CELL DYE/LDL MEASUREMENT (2) BINDING (3)SAMPLE RATIO (1) Value % oxid. 4° C. 37° C.______________________________________CS #1-1 20 1.8 23% 2.93 8.27 HUMAN CS #1-2 25 1.5 12% 6.3 16.42 HUMAN CS #2 15 2.1 33% 4.9 6.4 HUMAN ZYN #1 30 .97 0% 5.6 18.87 PORCINE ZYN #2 30 1.14 6% 7.3 22.87 PORCINE ZYN #3 30 1.09 4% 6.75 18.85 PORCINE HUMAN 0 CONTROL UNOXIDIZED 1.15 OXIDIZED 4.0 PORCINE 0 CONTROL UNOXIDIZED .98 OXIDIZED 3.5______________________________________ (1) Dye/LDL ratio refers to the number of dye molecules incorporated into an LDL particle (2) Oxidation measurement refers to the measurement of the samples at an absorbance of 360 nm which differentiates the oxidized versus nonoxidized state of the LDL particle. Low values are perceived as nonoxidized (see control samples), whereas high values indicate oxidation has occurred. % Oxidized = [(sample value - control value unoxidized)]/(control oxidize - control unoxidized) * 100 (3) Cell binding values indicate the fluorescence signal obtained from incubating 10.sup.5 lymphoblast cells (GMO) with 100 ul of a 100 ug/ml solution of labeled LDL particles. The 4° C. values represent surface receptor binding while the 37° C. samples indicate values for surface and internalized receptor binding. CS = commercial source ZYN = prepared by method of invention using Zynaxis PKH26-GL
EXAMPLE 2
LIPOPROTEIN RECEPTOR NUMBER AND FUNCTION ASSAY
The lipoprotein receptor number and function assay is performed on a blood sample as follows.
A blood sample is obtained from the patient using acid citrate dextrose anticoagulant to prevent clotting. The sample is derepressed to provide for maximal receptor expression. Derepression comprises removing the plasma component by centrifuging the sample, washing the cellular component (in e.g., Hanks Balanced Salt Solution (HBSS)-Ca-Mg, 0.25% BSA, 0.1% EDTA, 10 mM HEPES-KOH, pH 7.4) to remove residual plasma components (e.g. lipoprotein), and incubating the cells at 37° C. for 12-24 hours in lipid free medium to permit processing of any lipoprotein which may be bound to the cells. The media composition is important, and EDTA is included to dissociate any serum LDLs from the cells and to enhance receptor expression on cell surfaces. AIM-5 media (Gibco) has proven optimal for derepression. The result is a cell sample which has recycled lipoprotein-bound receptors and internal receptor pools to the cell exterior, maximizing potential for signal. After the incubation, the cells are centrifuged and resuspended in a volume of medium to the desired number of cells/ml.
LDL particles labelled with FMBC, according to the methods set forth in Example 1, are used as the receptor-selective marker to provide a red fluorescent signal to quantitate LDL receptor numbers. An excess of FMBC-labelled LDLs must be used to insure complete saturation of LDL receptors. This generally can be accomplished by using 100 ug of LDLs and 5×10 6 or fewer white blood cells. The LDLs are incubated with the concentrated blood sample for 2 hours at 4° C. to permit binding but no internalization of the LDL particles (i.e., a metabolically inhibitory temperature). A second set of samples are identically prepared and incubated at 37° C. for two hours to permit the internalization process to take place. An unlabelled control sample is also prepared to account for background signals.
After the LDL incubation, the cell samples are all cooled to 4° C. and are reacted for 30 minutes at 4° C. with a detectable reporter substance and a specific binding substance affixed to a solid support. These conditions are used for both the 4° C. and 37° C. LDL incubation samples. In this example, beta-galactosidase-conjugated antibody directed against the CD2 surface antigen of lymphocytes is used as the detectable reporter substance, at a concentration of 2-5 ug of antibody per 100 ul of whole blood (or 10 6 cells). The CD2 antigen is uniformly expressed on the cells of interest and will provide a linear relationship by which cell number can be determined. The specific binding substance/solid support is a monoclonal antibody attached to a magnetic bead either directly or indirectly and is directed toward the CD3 antigen. This CD3 antigen is present but does not interfere with the LDL receptor or CD2 binding domains. The magnetic bead to cell ratio should be 2 or greater to provide for saturation of all CD3 antigens present on the cell surface and the binding reaction is carried out for at least 30 minutes (or the time required to achieve saturation binding, which can be determined empirically) at 4° C. to prevent capping or shedding of the bound antibody by the cell.
At the conclusion of the incubation, the cells are placed in a magnetic field which will separate the cells which have formed a complex with the magnetic particles. The sample is washed several times using Hanks Balanced Salt Solution (HBSS)+Ca+Mg, 1% BSA in 10 mM HEPES-KOH (pH 7.6) to remove unbound LDL particles and any unbound or unincorporated reporter substances. The sample is then reacted with a substrate solution (e.g., methylumbelliferone) at a concentration of 0.1-1.0 mM (preferably 0.6 mM) to develop the signal component of the detectable reporter substance. This reaction is carried out at 30° C. for 30 minutes.
At the conclusion of the incubation, 50 ul of stop buffer containing 1% Triton X-100, 1 M glycine and 300 mM EDTA (pH 10) in water is added to the samples. The Triton serves to solubilize the cells and LDL particles, thereby releasing the FMBC component of the receptor-selective marker and enhancing its quantum efficiency.
The samples are then analyzed using a fluorescence based plate reader. The FMBC is measured using optimum excitation and emission wavelengths, according to the specifications provided by the supplier (e.g., for PKH 26-GL, 544 nm excitation wavelength and 590 nm emission wavelength). The filters are then changed in the instrument and the samples are measured again using optimum excitation and emission wavelengths (e.g., 355 nm and 420 nm, respectively) to detect the signal from the detectable reporter substance and determine cell number. Results are expressed as a ratio of FMBC signal to detectable reporter substance signal to provide information as to the number of receptors per cell for both the 4° C. receptor binding samples and the 37° C. internalization samples.
EXAMPLE 3
LDL/Apo B BINDING ASSAY
Evaluation of the binding capability ApoB proteins of LDL particles is performed as follows.
A blood sample is obtained from a patient using a red top Vacutainer® to promote clotting of the sample. The serum is collected from the tube and used for the diagnostic test. A LDL binding reagent is used as a source of receptors for the lipoprotein of interest. This example employs a cultured cell line, of human acute lymphoblastic leukemia cells (CEM cells, ATCC, Rockville, Md.), as the lipoprotein binding reagent.
LDL particles labelled with FMBC according to the methods set forth in Example 1 are used as a labelled lipoprotein standard, providing a red fluorescent signal to quantitate the total number of receptors present in the sample, optimally consisting of 1×10 4 to 1×10 6 cells. The assay will provide information as to how well the LDLs from the patient's sample are able to compete with the labelled LDLs for receptor binding sites on the cells. This is accomplished by preparing various assay samples containing the lipoprotein binding reagent (i.e., the above-referenced CEM cells), a fixed amount of FMBC-labelled LDLs and a fixed volume of the patient's serum, e.g., 4×10 5 cells in 100 ul of binding buffer (HBSS+Ca+4mM Ca++, 2% BSA, 0.1% NaN 3 ), or various dilutions thereof. For example, 50 ul of FMBC-labelled lipoprotein at a concentration of 50 ug/ml and 100 ul of a 1:2, 1:4, 1:8, 1:16 diluted serum sample may be utilized. An excess of LDL particles (consisting of FMBC-labelled LDLs+unlabelled patient LDLs) must be used to insure equilibrium saturation of all of the LDL receptors present in the sample. The assay samples are allowed to incubate for at least 2 hours at room temperature to permit binding of the LDL particles. If fixed cell reagents are used, internalization will not occur.
After the LDL incubation, the assay samples are cooled to 4° C. and are reacted with the specific binding substance/solid support compound for 10-30 minutes at 4° C.
In this example, Hoechst nuclear stains are used as the detectable reporter substance. This compound fluoresces in the ultraviolet region and binds to the DNA in the cell nucleus. The concentrations used, ranging from 0.5 to 4.0 mg/ml are selected to provide a linear relationship between cell number and signal. The specific binding substance/solid support in this example is a monoclonal antibody attached to a magnetic bead either directly or indirectly and is directed toward the CD 5 antigen present on the CEM cells. This CD 5 antigen is present but does not interfere with the LDL receptor or DNA binding domains. The bead to cell ratio should be 2 or greater to provide for saturation of all CD5 binding sites present on the cell surface. The labelling is carried out for 30 minutes (or the time required to achieve saturation binding) at room temperature. If live cells are used as the LDL binding reagent, the bead incubation should be carried out at 4° C. to prevent capping or shedding of the antibody/bead complex by the cell.
At the conclusion of the incubation, the assay samples are placed in a magnetic field which separates the magnetic particles and attached cells. The cells are washed (HBSS+Ca+Mg+0.5% BSA, 0.02% NaN 3 ) to remove unbound LDL particles.
After washing, the samples are analyzed using a fluorescence based plate reader. The samples are measured using an excitation wavelength of 355 nm and an emission wavelength of 460 nm to detect the ultraviolet signal from the Hoescht nuclear stain to determine cell number. Next, 50 ul of 0.5% Triton X-100 in 1 M glycine, pH 10, with 0.14 mM NaN 3 (final Triton concentration 0.1%) is added to the samples. The Triton serves to solubilize the cells and LDL particles, thereby releasing the FMBC component of the receptor-selective label and enhancing its quantum efficiency. The filters are then changed in the instrument. FMBC is detected using optimum excitation wavelengths (e.g., 544 nm and 590 nm, respectively, for PKH 26-GL) to provide a comparison of the samples containing FMBC labelled LDLs only (providing the maximum signal per sample value) and the samples containing FMBC labelled LDLs and dilutions of the patient's serum. Results are expressed as a ratio of FMBC signal to UV signal.
While certain preferred embodiments of the present invention have been described and specifically exemplified above, it is not intended to limit the invention to such embodiments. Various modifications may be made thereto without departing from the scope and spirit of the present invention, as set forth in the following claims. | The present invention provides methods and reagents for assessing lipoprotein metabolism. The methods provided are applicable for use on multiple samples in a clinical laboratory, thus obviating the need for sophisticated instrumentation, such as flow cytometry. Selected cell types in a test sample are uniformly labelled with a detectable reporter substance, so that they may later be enumerated. Pre-determined lipoprotein receptors associated with the cells of interest are labelled with a receptor-selective marker, thereby to determine the number of lipoprotein receptors per cell in the test sample. Selected cells of interest are conveniently separated from the test sample by binding thereto a specific binding substance attached to a solid support. The specific binding substance binds specifically with a characteristic determinant of the cell subset of interest. The remainder of the test sample may be washed away or discarded. The separated cells of interest may then be enumerated by measuring the amount of detectable label associated therewith, hence to determine the number of lipoprotein receptors per cell in each test sample. | 8 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 11/982,327, filed Nov. 1, 2007, which claims the benefit of U.S. Provisional Application No. 60/855,971, filed on Nov. 1, 2006.
[0002] The entire teachings of the above applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. No. 5,999,417 (the '417 patent) and U.S. Pat. No. 7,050,309 (the '309 patent) describe what is here referred to as the “Intermediate Bus Architecture” and “bus converters.” The entire teachings of these patents are incorporated herein by reference.
[0004] The Intermediate Bus Architecture (IBA) has become a popular approach for providing multiple output voltages (for loads such as digital circuits) from a single input voltage source. A first dc-dc converter (sometimes called a “bus converter”), usually providing isolation through a transformer, is used to change the source voltage, say 48V, to an intermediate voltage, say 12V. This intermediate voltage is then used as the input to several non-isolated dc-dc converters (sometimes called “P.O.L. converters,” for “point-of-load”) or linear regulators, each of which create a regulated output voltage appropriate for their respective loads.
[0005] When the range of the source voltage is narrow enough, the bus converter can be a device that normally does not regulate. It simply isolates and converts the source voltage to the intermediate voltage by virtue of the turns-ratio of its transformer. For instance, it may have a turns-ratio of 4:1, so that a 48V source becomes a 12V intermediate voltage. As the source voltage ranges from 38V to 56V, the intermediate voltage correspondingly ranges from 9V to 14V. This type of bus converter will be referred to herein as a “non-regulated bus converter.”
[0006] Since the non-regulated bus converter does not normally regulate (it regulates only during a turn-on or turn-off transient, or during a current-limit condition, and the like), the intermediate voltage displays a “droop” characteristic. By this it is meant that the value of the intermediate voltage decreases as the current flowing out of the bus converter increases. For the example given above, this might make the intermediate voltage range from 8.5V to 14V over the full range of source voltage and bus converter output current.
[0007] This variation of the intermediate voltage is acceptable since the P.O.L.'s can typically operate over such a range of their input voltage.
[0008] When the range of the source voltage is wider, such as 36V to 75V, or even 36V to 100V, then a different type of bus converter is often used because the non-regulated bus converter would give too much variation in the intermediate voltage for the P.O.L.'s to handle. This second type of bus converter, referred to herein as a “semi-regulated bus converter,” provides regulation (as well as isolation) so that the intermediate voltage does not vary proportionally to the source voltage. To first order it holds the intermediate voltage approximately constant, although it does permit this voltage to droop as the bus converter's output current increases so that some costs might be saved. For this reason, this type of bus converter is referred to as “semi-regulated.” The droop in the intermediate voltage, which might be around 5% to 10% of the nominal voltage as the bus converter's output current ranges from zero to full rated current, is well within the range of what a typical P.O.L. can handle for its input voltage.
[0009] A semi-regulated bus converter has a lower level of performance, in terms of efficiency and power handling capability, than the non-regulated bus converter as a result of its design to provide regulation over the full range of the source voltage.
SUMMARY OF THE INVENTION
[0010] To address the problem of reduced performance of the bus converter for an application where the source voltage range is relatively wide, a new type of bus converter is presented here. This bus converter, herein called a “quasi-regulated bus converter,” is normally non-regulating over some portion of the source voltage operating range, and regulating (either fully regulating or semi-regulating) over another portion of the operating range. The operating range is the intended source voltage range where the system is expected to operate and meet its specifications and is generally specified for each converter and/or for the application in which it is applied. Typically, the converter only receives a source voltage outside its operating range during a transient such as start up or shut down.
[0011] For instance, in a system where the input voltage ranges from 36V to 100V, the quasi-regulated bus converter might be designed so that it does not normally regulate when the source voltage is between 36V and 56V. If the transformer turns ratio is 4:1, the intermediate voltage would then vary from 9V to 14V if we do not account for the droop characteristic, and from perhaps 8.5V to 14V if we do account for the droop.
[0012] When the source voltage is between 56V and 100V, the quasi-regulated bus converter would then regulate its output, perhaps with a droop characteristic. In one example, the intermediate voltage would remain constant at 14V (perhaps minus a droop) over this 56V-100V range of source voltage.
[0013] With such an approach, the quasi-regulated bus converter keeps the intermediate voltage within a range that is acceptable for typical P.O.L.'s, but it does not try to regulate or semi-regulate the bus voltage to a range as tight as 10% (or so), as the semi-regulated bus converter would. As such, the quasi-regulated converter is capable of achieving an efficiency and power handling capability that is higher than the semi-regulated bus converter.
[0014] The exact details of how the source voltage range should be divided between these two modes of operation in the quasi-regulated converter are flexible, and they depend on the design of the converter and on the details of the application.
[0015] For instance, the non-regulated mode of operation might be at the high end of the source voltage range instead of the low end, as mentioned in the example above. It might even be in a middle section of the source voltage range, with regulation occurring at either end of the range. The acceptable range of the intermediate voltage might be different than the example given above based on the needs of the P.O.L's or on a desire to optimize the performance of the total system. For instance, the onset of the regulation range might occur in the 50V-52V level, instead of the 56V level mentioned previously.
[0016] Provisions for handling start-up and shut-down, and protection features such as over-voltage, over-current, over-temperature, and back-drive current limiting would be added to the quasi-regulated bus converter as required.
[0017] A dc-dc converter system may comprise a bus converter that receives a source voltage and converts the source voltage to an output. The bus converter may include a control circuit that normally controls the bus converter to cause a non-regulated mode of operation, over a portion of an operating range of a source voltage, where the output is non-regulated. The control circuit normally causes a regulated mode of operation, over another portion of the operation range of the source voltage, where the output is regulated. A plurality of regulation stages each receive the output of the bus converter and regulate a regulation stage output.
[0018] The bus converter may be an isolation stage while the regulation stages are non-isolating. The regulated mode of operation of the bus converter may be a semi-regulated mode. The regulation stages may be switching regulators.
[0019] The bus converter may comprise at least one transformer with at least one primary winding and at least one secondary winding. The primary winding circuit receives the source voltage and has an input filter with an input inductor. The secondary winding circuit has plural controlled rectifiers with parallel uncontrolled rectifiers, and output filter having an output inductor and the bus converter output.
[0020] For the non-regulated mode of operation, the control circuit may control the duty cycle of the controlled rectifiers to cause substantially uninterrupted flow of power through the dc-dc converter. Each controlled rectifier of the secondary winding circuit may be turned on and off in synchronization with a voltage waveform across a primary transformer winding to provide the output. Each primary winding may have a voltage waveform for the non-regulated mode of operation with a fixed duty cycle and transition times which are short relative to the on state and off state times of the controlled rectifiers.
[0021] The bus converter may comprise a filter having an inductor that saturates during a non-regulating mode of operation. Such inductors may be included in an input filter and/or in an output filter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views.
[0023] The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
[0024] FIG. 1 : Block diagram of an Intermediate Bus Architecture (IBA).
[0025] FIG. 2 : One example of a Bus Converter power circuit topology which, based on how it is controlled and on the component selection, could be used for all three types of Bus Converters.
[0026] FIGS. 3A-C : Three possible ways to divide the total range of V S into non-regulating and (semi-)regulating regions.
DETAILED DESCRIPTION OF THE INVENTION
[0027] FIG. 1 shows a block diagram of an Intermediate Bus Architecture. The source of power 101 provides a dc voltage V S , which may nominally be, for example, 48 volts, but which may vary over a range above and below this nominal, the width of the range being dependent on the application. The bus converter 102 then converts this voltage to a different nominal voltage; for example 12V. It also provides the electrical isolation needed for safety regulations and to avoid ground loop noise problems.
[0028] The output of the bus converter provides an intermediate voltage V I 103 . Capacitors 104 are typically connected between this intermediate node and ground to provide additional filtering. Also connected to the intermediate node are the inputs of several non-isolated switching regulators 105 , which are called P.O.L.'s. These P.O.L.'s are usually “buck-converters,” and in today's technology they often incorporate synchronous rectifiers to improve efficiency. They each create an output voltage 106 that is held constant (i.e. regulated) even as the intermediate voltage or their output current varies. These output voltages are typically supplied to digital and analog load circuitry.
[0029] It is also possible for one or more of the P.O.L.'s to be of a design that gives an output voltage higher than the intermediate voltage, or to give an output voltage that is negative with respect to the ground potential. Various topologies such as a “boost-converter,” a “buck-boost converter,” and a “Sepic converter” could be used for these purposes, and they (and others) are well known in the art.
[0030] The bus converter of FIG. 1 could be a non-regulated bus converter, a semi-regulated bus converter, or, as described herein, a “quasi-regulated bus converter.” The choice depends, in part, on how much the source voltage varies and on how wide a range of intermediate voltage the P.O.L.s can tolerate. Some sources stay within a relatively tight range; for example 48V±10%. Others vary over a moderate range; for example 36V to 56V. Yet others have a very wide range, for example 36V to 100V. Some P.O.L.'s are designed to handle an input voltage that is relatively tight; for example 12V±20%. Others are designed to handle a wider range; for example 7V to 15V.
[0031] One example of a non-regulated bus converter is described in the '309 patent. As shown in FIG. 2 here, it uses a full-bridge topology for the switches 201 - 204 connected to the primary winding 209 of the isolation transformer, and a center-tapped topology for the secondary side. Synchronous rectifiers, composed of controlled rectifiers 205 and 206 and their corresponding uncontrolled rectifiers 207 and 208 are connected to the center-tapped secondary windings 210 and 211 , respectively. The synchronous rectifiers are typically MOSFETs, where the channel is the controlled rectifier and the parasitic body diode is the uncontrolled rectifier. An external diode could also be used for the uncontrolled rectifier.
[0032] A capacitor 214 may be placed in series with the primary winding 209 to ensure flux balance. Other means of achieving flux balance are well known in the art.
[0033] Inductors 212 and 213 represent the leakage inductance of the transformer.
[0034] Inductor 216 and capacitor 217 form a low-pass output filter. The voltage across capacitor 217 is the intermediate voltage 103 shown in FIG. 1 . Capacitor 218 and inductor 219 provide a low-pass filter for the bus converter's input. It may be connected directly to the source voltage 101 , or there may be additional filter elements between the two.
[0035] A control circuit 220 provides the gate drive signals for the various power switches. It typically senses voltages and currents within the power circuit, and it provides the desired duty cycle/switch timing for the switches.
[0036] During normal operation the circuit is operated at a fixed duty cycle where a positive voltage (of value V S ) is applied across the transformer's primary winding for the first half of the cycle, and a negative voltage (−V S ) is applied across the winding for the second half of the cycle. Except for the relatively short switch transition times between these two half cycles, power is always flowing from the source, through the transformer, and then to the output of the bus converter. Except for the short switch transitions, there is no explicit “freewheeling” portion of the cycle where the power flow through the transformer is interrupted and the flow of power to the output is maintained by the output inductor 216 and capacitor 217 alone.
[0037] The synchronous rectifiers in the secondary circuit rectify the output of the transformer and create a dc voltage. This is than passed through the low-pass filter 216 , 217 . The components in this filter, particularly the inductor, are relatively small due to the fact that during normal operation they only need to filter the interruption of power during the short switch transition times at the end of each half-cycle. These interruptions might last only about 50 ns, which is very short compared to the half-cycle, which may be 2 us long, depending on the details of the design.
[0038] Consider the case where the source voltage varies over a relatively narrow range from 36V to 56V. Assume the turns-ratio of the transformer is 4:1 (primary to secondary). If there were no load current flowing, the output voltage of the bus converter, V I , would be approximately ¼ that of the source voltage, V S . In other words, V I would range from 9V to 14V. However, as the load current builds, the V I falls, or “droops,” due to the resistances of the power path and the voltage drops required across the leakage inductances to commutate the current from one secondary winding to the other each half cycle. This droop might typically be about 0.5V at full load current, so the output voltage would range from approximately 8.5V (at full load and V S =36V) to 14V (at zero load and V S =56V).
[0039] This non-regulated bus converter can be very efficient (typically 97%) for several reasons, all associated with the fact that it does not normally make use of a freewheeling portion of the cycle to regulate. First, power is transferred from source to output for nearly 100% of the cycle and as a result, the rms value of the current flowing through all the components of the converter is minimized. Second, the turns-ratio of the transformer can be higher than it otherwise would be, so that the currents flowing on the primary side are smaller for a given output current and the off-state voltage ratings of the synchronous rectifiers are smaller for a given maximum source voltage. Third, the switch transitions between one half-cycle and the next are nearly lossless because there is not a need to recover from a freewheeling period. Fourth, the output inductor 216 is relatively small in value, and as a result can be relatively low in losses for a given volume of the device.
[0040] In addition, the non-regulated bus converter does not need to have control signals that bridge the isolation barrier between the primary and secondary sides of the circuit. As mentioned in the '417 patent, there is no need to feed back a signal representing the output voltage since there is no attempt to regulate it. There is also no need to send control signals to the synchronous rectifiers. Their control signals can be easily derived from the voltages on the secondary windings, as described in the '309 and the '417 patents. Besides saving cost, this lack of circuitry that bridges the isolation barrier permits the transformer to occupy the entire physical width of the converter, and therefore it can have a lower winding resistance, higher efficiency, and better thermal performance.
[0041] During transients such as startup and shutdown, or in situations where the output current must be limited from getting either too high or too negative, the non-regulated bus converter may be operated with a duty cycle less than 100%, and therefore with an associated freewheeling period. For instance, at startup the duty cycle may be slowly ramped from 0% to 100% to cause the output voltage V I to slowly rise to its final value. As explained in the '309 patent, there are additional losses during these abnormal conditions due to dissipative switch transitions and the fact that the controlled rectifiers may not be conducting during the freewheeling period, depending on the control strategy used. In addition, the output ripple voltage may be larger than normal. But these conditions can be tolerated since they are transient in nature and do not represent the normal use of the non-regulated bus converter.
[0042] When the input voltage varies over a range that is too wide to use a non-regulated bus converter with a given P.O.L technology, a semi-regulated bus converter is often used. Such a bus converter could have the same full-bridge topology shown in FIG. 2 . The difference is that now the converter is designed to have its duty cycle vary as the source voltage varies so that the intermediate voltage V I stays near a nominal value. For instance, if the source voltage V S varies from 36V to 100V, the semi-regulated bus converter might be designed to have a duty cycle near 100% when V S =36V, and a duty cycle of about 36% when V S =100V.
[0043] Since it is not necessary, in an IBA application, to have the intermediate bus voltage be fully regulated, a semi-regulated converter is usually designed such that the feedback signal that determines the duty cycle is derived from one or more signals available on the primary side of the converter that are indicative of the output voltage. One possible signal is the source voltage, V S . Another possible signal is the voltage across the primary transformer winding.
[0044] These signals do not account for voltage drops across resistances in the power path, nor do they account for the voltage drops across leakage inductances that are required to commutate the load current from one secondary winding to the other. As such, a semi-regulated bus converter will have an output voltage that falls, or droops, as the load current is increased. A droop of 5%-10% is typical as the load current varies from zero to full rated current.
[0045] If the droop is larger than desired, then it is possible to reduce it by measuring a signal on the primary side that is indicative of the current flowing through the power stage. This signal, multiplied by an appropriate gain, can be used to modify the duty cycle to give a higher output voltage to compensate for the droop, as described in the '417 patent. Since the resistances of the power path are temperature dependent, it might also be desirable to adjust the effect of this compensation circuitry as a function of the converter's temperature.
[0046] A semi-regulated bus converter cannot be as efficient as a non-regulated bus converter, all other things held constant. By definition, it has a freewheeling period for all values of the source voltage except, perhaps, the lowest. It therefore isn'table to fully utilize the transformer and the power switching devices. There is also a significant switching loss at the end of each freewheeling period due to the leakage inductance of the transformer and the parasitic capacitances of the power switches. Third, the transformer's turns ratio would be lowered, which means that the currents on the primary side are higher for a given load current and the off-state ratings of the synchronous rectifiers are higher for a given maximum source voltage. Finally, the output inductor would be made relatively large in value to minimize the ripple in its current and the intermediate voltage. This large value of inductance translates into a physically larger and more dissipative device.
[0047] For instance, if the source voltage ranges from 36V to 100V, and the output voltage is to be nominally 12V (not counting the droop), the turns ratio for a semi-regulated bus converter must be 3:1. If the source voltage had been 48V±10% and a non-regulating bus converter were used, it could have a turns ratio of 4:1 to create a nominal 12V output. This difference is significant with regard to the bus converter's efficiency.
[0048] The output filter must do much more filtering on the semi-regulated bus converter than it has to on the non-regulated bus converter. Instead of just brief interruptions of power flow during the switch transitions each half cycle, now the output filter must deal with interruptions that last for the duration of the freewheeling period. In general, this means that the output inductor must be much larger in value, peak energy storage, and physical size. As a result, more power is dissipated in this inductor, and there is less room available on the converter for other components.
[0049] For example, consider the size of the non-regulated bus converter's filter inductor. During the switch transitions it will see the output voltage across it, but these transitions will last only about 50 ns. In comparison, for the semi-regulated bus converter, the filter inductor will see the output voltage across it for the length of the freewheeling period. In the example given above, the longest freewheeling period is 64% of the cycle when V S is 100V. If we assume a switching frequency of 250 kHz, or 2 μs for each half cycle, then this maximum freewheeling period would be 1.28 μs long. To maintain the same current ripple in the inductor, the value of inductance would therefore need to be increased by a factor of 25 for the semi-regulated bus converter as compared to the non-regulated bus converter. This increase is so large that a more reasonable design might call for more inductor ripple current (to limit the size of the inductor) and more output capacitor to achieve the required ripple level in V I .
[0050] Overall, holding all other things constant, a semi-regulated bus converter that must handle a wide range of source voltage might be 94% efficient, while a non-regulated bus converter that is designed to handle a narrower range of source voltage might be 97% efficient. This difference translates into about twice the dissipated power for the former compared to the latter, and therefore results in a lower power handling capability for the semi-regulated bus converter.
[0051] An alternate approach, newly described here, is the quasi-regulated bus converter. As mentioned earlier, this bus converter operates as a non-regulated bus converter over a portion of the range of the source voltage, but then regulates its output over the rest of the range. In general, when the quasi-regulated converter is regulating its output, it may do so with or without a droop characteristic.
[0052] The portion of the source range over which the bus converter is non-regulating may be the low end of the range, the high end of the range, or some other portion, as depicted in FIG. 3 , depending on the design of the converter. FIG. 3 a depicts the case where the non-regulating range is at the lower end of the total range of V S . FIG. 3 b depicts the case where the non-regulating range is at the higher end. And FIG. 3 c depicts the case where the non-regulating range is in the middle of the total range of V S .
[0053] As one example, a quasi-regulated bus converter could have the same full-bridge topology shown in FIG. 2 . Since this topology is inherently a down-converter when it is regulating, the converter would be designed to be non-regulating over the lower end of the source range, and then regulating, or semi-regulating, over the higher end of the range.
[0054] Assume the source voltage ranges from 36V to 100V and that the P.O.L.'s can tolerate an intermediate voltage that varies between 7V and 15V. If the transformer is given a turns-ratio of 4:1, then when the quasi-regulated bus converter is operated in a non-regulating manner where its duty cycle is nearly 100% (except for the short switch transitions), the intermediate voltage V I will be approximately ¼ that of the source voltage V S , minus the droop. Assume that this mode of operation exists whenever the source voltage is in the 36V to 56V range. This would result in an output voltage that varies from 9V to 14V at zero bus converter output current. If we consider the droop, the output voltage might vary from 8.5V to 14V over the full range of source voltage and bus converter output current. This range can be handled by the P.O.L.'s mentioned above with appropriate margins at both ends of the range.
[0055] Once the source voltage gets above 56V, the control circuit 220 of the quasi-regulated bus converter will reduce the duty cycle appropriately to keep the output voltage from rising any higher than, say, 14V. The control strategy during this range of source voltage could be the same as is used in the semi-regulating bus converter, in which case the output voltage will display a droop characteristic in this mode of operation, as well. Just as for the semi-regulated bus converter, this droop could be reduced by making use of a signal indicative of current (and of temperature, for further accuracy). Or the control strategy could, if desired, create a tightly regulated output by feeding back a signal from the output. The former approach is simpler, cheaper, and all that is needed for many IBA applications.
[0056] The advantages gained by using the quasi-regulated bus converter approach instead of the semi-regulated bus converter are several. First, the turns-ratio of the transformer is 4:1 instead of 3:1. This reduces both the current levels in the primary side of the circuit and the voltage stresses on the secondary side by 25%.
[0057] Second, the maximum freewheeling period will be only 44% of the half-cycle period for this example of the quasi-regulated bus converter, as compared to a 64% value for the corresponding semi-regulated bus converter. This permits the output inductor to be reduced by approximately 33% in value.
[0058] Because V I can go as low as 9V for the example given above, the output inductor of the quasi-regulated bus converter must carry a higher maximum dc current than does the inductor in the semi-regulated bus converter whose output voltage remains at 12V (ignoring droop in both cases). For instance, if we assume the output power of the bus converter is 240 W, the quasi-regulated bus converter's inductor would have to carry a dc current of 27 A; whereas, the semi-regulated bus converter's inductor would have to carry only 20 A. This would appear to require that the inductor of the quasi-regulated bus converter be designed to store much more peak energy, even though its inductance value is smaller.
[0059] However, it is possible to let the quasi-regulated bus converter's inductor saturate at the higher current levels associated with V S below 56V and V I therefore falling below 14V (again, ignoring droop) since for that condition, the converter is being operated at nearly 100% duty cycle and very little output inductance is therefore required. The residual inductance that remains after the core saturates will typically be sufficient. Doing this makes the quasi-regulated bus converter's output inductor much smaller than can be achieved with the semi-regulated bus converter.
[0060] Similarly, the input filter inductor 219 could be made physically smaller by allowing it to saturate when V S is low enough such that that quasi-regulated bus converter is operating at nearly 100% duty cycle. In this condition there is much less ripple caused at the input compared to when there is a freewheeling period, and so less input filter inductance is needed.
[0061] An additional advantage of the quasi-regulated bus converter is the fact that it avoids the switching losses of recovering from a freewheeling period over a significant portion of the range of the source voltage. For instance, in the example given above, when V S is low and the currents are therefore relatively high, the quasi-regulated bus converter is operating with nearly 100% duty cycle, which keeps the switching losses small just when the conduction losses are at their highest. At higher values of V S , when the duty cycle is reduced below 100% and the switching losses increase, the currents are then lower so that the conduction losses are smaller. Overall, the total dissipation in the semiconductor devices is reduced compared to the semi-regulated bus converter for any given operating point.
[0062] Overall, holding all other things constant, a quasi-regulated bus converter able to handle a source voltage range of 36V to 100V will be about 96% efficient, as compared to a semi-regulated bus converter which would be only 94% efficient. This results in only two-thirds the power dissipation for the same output power, and will permit a higher power density capability.
[0063] The description of the quasi-regulated bus converter presented above has been based on a power circuit topology that is an isolated down-converter. It is also possible to base a quasi-regulated bus converter on a topology that is an isolated up-converter, such as a center-tapped, push-pull topology. For this topology, the control strategy might be to maintain 100% duty cycle for the high end of the source voltage, and then reduce the duty cycle (and therefore increase the output voltage) when the source voltage is at the lower end of its range.
[0064] Similarly, one skilled in the art could configure a quasi-regulated bus converter based on an isolated up-down converter. For this topology the control strategy might be to maintain 100% duty cycle for the middle portion of the range of the source voltage, and then regulate at both the low and the high end of the range.
[0065] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation many equivalents to the specific embodiments of the invention described specifically herein. Such equivalents are intended to be encompassed in the scope of the claims. For instance, other topologies besides the full-bridge topology, such as the half-bridge topology and others known in the art could be used. In addition, the ideas presented above for isolated bus converters could also be used for bus converters based on non-isolated power circuit topologies. | A dc-dc converter system comprises a quasi-regulated bus converter and plural regulation stages that regulate the output of the bus converter. The bus converter has at least one controlled rectifier with a parallel uncontrolled rectifier. A control circuit controls the controlled rectifier to cause a normally non-regulated mode of operation through a portion of an operating range of source voltage and a regulated output during another portion. The bus converter may be an isolation stage having primary and secondary transformer winding circuits. For the non-regulated output, each primary winding has a voltage waveform with a fixed duty cycle. The fixed duty cycle causes substantially uninterrupted flow of power during non-regulated operation. Inductors at the bus converter input and in a filter at the output of the bus converter may saturate during non-regulated operation. | 8 |
This is a division of application Ser. No. 08/722,704 filed Sep. 30, 1996 now U.S. Pat. No. 5,916,506.
BACKGROUND OF THE INVENTION
This invention relates to the field of electrically conductive fibers, especially antistatic fibers comprising polymeric materials, and a means for making same.
In many applications where fibrous materials are used, static electricity is often problematic. For example, in laybelt applications, where monofil fibers are often used, or in carpeting, where multiple yarns are frequently preferred, friction often produces static charges that interfere with the use or enjoyment of the material. Static electricity can cause a spark discharge of a static electrical charge that has built up, usually as a result of friction, on the surface of a non-conductive material. A material having a sufficient amount of electrical conductivity, i.e. low electrical. resistivity, to dissipate an electrical charge without a spark discharge would not exhibit problematic static electricity.
U.S. Pat. No. 3,969,559 teaches a textile antistatic strand comprising a thermoplastic polymer in which carbon black is uniformly dispersed to provide conductivity. The antistatic strand is partially encapsulated by another, non-conductive, thermoplastic polymer constituent. The electrical conductivity decreases as the tenacity of the fiber increases with increased draw and hot roll temperature.
U.S. Pat. No. 4,185,137 teaches a conductive sheath/core heterofilament having a thermoplastic polymer core in which is dispersed a material selected from the group consisting of zinc oxide, cuprous iodide, colloidal silver, and colloidal graphite.
U.S. Pat. No. 4,255,487 teaches an electrically conductive textile fiber comprising a polymer substrate which contains finely divided electrically conductive particles in the annular region at the periphery of the fiber.
U.S. Pat. No. 4,610,925 teaches an antistatic hairbrush filament having a nylon or polyester core and a compatible polymeric sheath containing carbon.
U.S. Pat. No. 3,803,453 teaches a synthetic filament comprising a continuous nonconductive sheath of synthetic polymer surrounding a conductive polymeric core containing carbon.
Although it is known to make conductive or antistatic polymeric fibers by including conductive particles, when such fibers are drawn to increase the strength of the fiber or orient the polymer molecules the conductivity is significantly reduced or eliminated.
SUMMARY OF THE INVENTION
The present invention is a polymeric antistatic bicomponent fiber comprised of a nonconductive component which comprises a first polymer and a conductive component which comprises a second polymer containing a conductive material at a level of at least 3% by weight. The conductive component has a resistivity of no more than about 10 8 ohm cm. The second polymer has a melting point of at least 180° C., and preferably at least 200° C. The first polymer melts at a temperature at least 20 C. higher than the second polymer and preferably at least 30° C. higher. The two components are each a continuous length of polymer which together make up a fiber which typically has a circular cross-section, though other cross-sections can also be made and are within the scope of the invention. The two components can be in a side-by-side or sheath-core arrangement with respect to one another. The two components adhere to each other sufficiently well that the two components do not separate from one another. The first component comprises about 50% to about 85% by weight of the fiber, and the second component about 15% to about 50% of the fiber. The bicomponent fiber is preferably in the form of a sheath-core fiber, having a non-conductive core made of the first polymer and a conductive sheath made of the second polymer, which contains a conductive material at a level of at least 3% by weight. The conductive sheath has a resistivity of no more than about 10 8 ohm cm. The fiber can be used as part of a multifilament yarn or can be used as a monofil. It can be used as a continuous filament or chopped into staple. The preferred fiber is a monofil having a diameter of at least 0.1 mm and preferably at least 0.25 mm.
A process for making such a fiber comprises the following steps: (1) co-extruding the first polymer and the second polymer, which contains a conductive material, at a temperature above the melting point of the first polymer to form a bicomponent fiber, which preferably is a sheath/core fiber, in which the core is made up of the first polymer and the sheath is made up of the second polymer; (2) stretching the fiber at a temperature below the melting point of the second polymer to form a stretched fiber with improved tensile properties; and (3) heat treating the stretched fiber at a temperature between the melting point of the first polymer and the melting point of the second polymer. Preferably, the lower melting polymer (the second polymer) has a melting point of at least 180° C., and preferably at least 200° C. The two melting points are at least 20° C. apart, and preferably at least 30° C. apart. Conductivity decreases or is lost when the fiber is stretched, apparently due to the disruption of the conductive sheath. The conductivity is partially or fully restored during the heat treatment.
It is an object of the present invention to provide an antistatic polymeric fiber having tensile properties comparable to ordinary polymeric fibers.
It is also an object of the present invention to provide a fiber having a nonconductive core containing a first polymer and a conductive sheath containing a second polymer.
It is a further object of the present invention to provide a novel process for making an antistatic polymeric fiber having a nonconductive core containing a first polymer and a conductive sheath containing a second polymer.
It is also an object of the present invention to provide a fiber having the tensile properties of a drawn, oriented polyester fiber and a resistivity in the sheath layer of no more than 10 8 ohm cm.
Other objects and advantages of the present invention will be apparent to those skilled in the art from the following description and the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In one preferred embodiment of the present invention, poly(ethylene terephthalate) (“PET”) is chosen as the core polymer and carbon-filled poly(butylene terephthalate) (“PBT”) is selected as the conductive sheath polymer. The PBT contains at least 3%, and preferably about 5% to about 15% by weight carbon particles (powder and/or fiber). These polymers are commercially available in a molecular weight suitable for fiber formation. The polymers are coextruded from a heterofil spinneret at a temperature of about 270° C. to about 290° C. to form a sheath/core fiber, which comprises a core of PET and a sheath of carbon-filled PBT.
The extruded sheath/core fiber has sufficient conductivity to provide antistatic properties. The fiber is then drawn to about four times its initial (as-extruded) length to increase its tensile strength, causing a loss of conductivity. Subsequently, the fiber is heat treated at about 240° C., restoring the conductivity. The heat treatment time is typically less than one minute, and can be selected by experimentation to give a desired conductivity, since the conductivity increases with increasing heat treatment time.
PET and PBT adhere well together because they are partially miscible. They have approximate melting temperatures of 265° C. and 235° C., respectively. These characteristics make these polymers wellsuited for use together in the present invention. The conductive PET/PBT fiber has an excellent combination of properties, including relatively high strength, low shrinkage, and low density. The high tensile strength and low shrinkage are characteristic of a drawn PET fiber. The sheath provides antistatic properties, while the strength of the PET core is retained. Tensile properties as measured by ASTM Method D-2256 are typically as high or higher than about 2 gpd tenacity and 40 gpd modulus, preferably higher than about 3 gpd tenacity and 50 gpd modulus.
In the practice of this invention, it is important to select two polymers that adhere to each other sufficiently to form a good bicomponent (sheath/core) fiber. It is also important that the lower melting sheath polymer does not degrade significantly under the processing conditions, particularly when co-extruded at a temperature above the melting point of the core polymer. It is generally desirable to choose a sheath polymer that has a melting point of at least about 180° C.
To obtain a fiber that has good orientation and/or tensile properties, it is necessary that the heat treatment does not melt the core polymer. Consequently, a melting point difference of at least 20° C. between the two polymers is desirable, and preferably at least 30° C.
Although PET and PBT are specifically mentioned herein, other suitable polymer pairs can also be used in the practice of this invention. Examples include PET with other polyesters such as polyethylene terephthalate/adipate copolymer or polyethylene terephthalate/isophthalate copolymer. Furthermore, polymers other than polyesters may be used in the practice of this invention, such as PET paired with nylon 11 or nylon 12. Those skilled in the art will readily be able to determine whether two polymers are suitable in the practice of this invention without undue experimentation, based on the teachings herein.
The sheath polymer must have distributed therethrough an amount of one or more conductive materials such as graphite and/or metal particles, that provides sufficient conductivity to allow static electricity to dissipate without spark discharge. Generally, a resistivity of no more than about 10 8 ohm cm, e.g. in the range of about 10 3 to about 10 8 ohm cm, is suitable for the sheath of the sheath-core fiber. Lower Festivities may also be obtained, if desired. Although an amount of about 5% to about 15% by weight has been found suitable for carbon or graphite particles in a polymer matrix, the amount may be more or less than this depending on the conductive particles, the polymer, and other factors. The conductive particles are included in amounts that are sufficient to provide antistatic properties, but not so much that the sheath polymer is no longer suitable as a fiber sheath due to overloading, which results in loss of physical integrity. The core polymer will generally comprise about 85% to about 50% by weight of the sheath/core fiber, and preferably about 80% to about 70%, with the balance being the sheath.
Although the fiber is stretched to about four times its initial length in the preferred embodiment described above, other stretching ratios may be desirable, especially if different polymers are used. Generally, the fiber should be stretched until it has achieved the desired tensile properties, according to common practice in the art. The loss of conductivity that occurs in the sheath due to the drawing step is then corrected by the heat treating step.
The following non-limiting examples illustrate selected embodiments of the present invention.
EXAMPLE 1
PET was chosen as the core polymer and carbon-loaded PBT was selected as the conductive sheath polymer. The PET had an intrinsic viscosity of about 0.9 dl/g. The PBT was a commercial conductive polymer from LNP Corp, sold under the name STAT-KON W™, and contained about 8% by weight carbon particles. The carbon-filled PBT melts at about 235° C., compared with PET, which melts at about 265° C. The polymers were thoroughly dried before spinning. The polymers were co-extruded at about 280° C. through a heterofil spinneret having a 3 mm diameter to make a 0.5 mm drawn fiber. The fiber was extruded horizontally into a water bath having a temperature of about 42° F. The water bath temperature was lower than normally used for PET to prevent crystallization of the PBT. The wind-up speed was about m/min. The weight ratio of filled PBT sheath to PET core was about 30:70. The as-extruded sheath/core fiber had an electrical resistance of about 160,000 ohm/cm. The fiber was then drawn to four times its initial length at a temperature of 90° to increase its tensile strength, resulting in an increase in the resistance to more than 10 million ohm/cm. Subsequently, the drawn fiber was heated to 240° C. by passing it through a meter oven at a speed of 24 m/minute. The air velocity was 600 m/minute. This corresponds to a residence time of 0.21 minute. A longer residence time results in a lower resistance. The residence time was chosen to give a resistance of about 160,000 ohms/cm after heat treatment. This is the same as the resistance before drawing. The fiber had also relaxed (shrunk) by about 2%. The drawn heat-treated fiber had the following tensile properties: 3.5 gpd tenacity and 36% elongation. The sheath portion of the fiber had a resistivity of 94 ohm cm.
The heat-treated fiber exhibited anti-static properties, resistance to abrasion, high strength, and low density. The adhesion between core and sheath were excellent, and the fiber was flexible.
EXAMPLE 2
A polyethylene terephthalate/adipate copolymer having a terephthalate to adipate mole ratio of about 85:15 and melting at about 226° C. was made by standard polymerization methods and was compounded in a twin screw compounder with 10% by weight of extraconductive carbon black, sold as PRINTEX™XE2 by Degussa. The filled polymer was pelletized, dried and fed into a bicomponent fiber spinning machine as the sheath over a concentric polyethylene terephthalate core. The sheath comprised about 25% by weight of the fiber. The resulting asspun fiber was 1 mm in diameter and had an electrical resistance of 2500 ohms/cm and a tensile strength of 0.28 gpd at 2% elongation. After hot drawing at a ratio of 4.4:1 and a temperature of 100° C., the resistance was 10 8 ohms/cm, and the tensile strength was 2.6 gpd at elongation of 34%. After relaxing by 2% at 240° C., the resistance was 22,000 ohms/cm, and the tensile strength was 3.1 gpd at 51% elongation. The sheath portion of the fiber had a resistivity of about 10 ohm cm.
EXAMPLE 3
A sheath/core fiber was made using the same process as in Example 2, except that the fiber was made on a larger scale in a commercial fiber spinning facility. The weight ratio of poly(ethylene terephthalate) to conductive polymer was 70:30 in these experiments. The process was run to packages for more than an hour through a 20 hole by 1.4 mm spinneret. The fiber was quenched in water at 45° C. and then drawn at 90° to a draw ratio of 4.4:1. The fiber was then annealed in a 260° C. oven for about 4 seconds, resulting in relaxation (shrinkage) of about 2%. The diameter of the monofil was about 0.40mm. The fiber had the following tensile properties, as measured by ASTM Method D-2256:
59 gpd modulus, 2.6 gpd tenacity, 49% elongation. The fiber had a resistance of 50,000 ohms/cm. The hot air shrinkage at 180° C. was 3%.
A duplicate experiment was run with the same polymers but with a draw ratio of 5:1 at 90° C., followed by 2% relaxation in a 260° C. oven for about 4 seconds. The fiber had a diameter of about 0.4mm. The tensile properties were: 63 gpd modulus, 3.3 gpd tenacity, 31% elongation. The hot air shrinkage was 3% at 180° C. The resistance was 50,000 ohms/cm.
The outside of the fiber was not as smooth as the outside of the fiber from Example 2, probably because the polymer in Example 2 was filtered, whereas the polymer in Example 3 was not filtered. The fibers in Example 3 had a higher resistance than the fibers in Example 2, probably because the fibers in Example 2 were annealed for a longer time.
EXAMPLE 4
A poly(ethylene terephthalate-isophthalate) copolymer is compounded with 8% by weight PRINTEX™XE2 carbon black to make a conductive compound. The compound is coextruded with PET to make a sheath/core polymer with the PET in the center and the conductive layer on the outside. The as-spun fiber is drawn at a ratio of 4.4 and a temperature of approximately 100°. The resistance of the fiber is high at this point. The fiber is then annealed at a temperature between the melting point of PET and the melting range of poly(ethylene terephthaiate/isophthalate). The annealed fiber has electrical resistance of 90,000 ohms/cm.
It is to be understood that the above described embodiments are illustrative only and that modification throughout may occur to one skilled in the art. Accordingly, this invention is not to be regarded as limited to the embodiments described herein. | An antistatic bicomponent fiber comprises a nonconductive first component made of a first polymer and a conductive second component made of a second polymer containing a conductive material, where the second polymer has a lower melting point than the first polymer. The bicomponent fiber is made by co-extruding the two polymers at a temperature above their melting points, stretching the extruded fiber to increase the tensile strength, and heat treating the fiber at a temperature between the melting point of the first polymer and the melting point of the second polymer to improve the conductivity of the conductive second component. The bicomponent fiber is preferably a sheath/core fiber. | 3 |
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates generally to papermaking, and includes an apparatus for deaerating an air-containing aqueous suspension of papermaking stock which is introduced into deaeration chambers or wings extending from a stock receiver. More specifically, the present invention is directed to a papermaking apparatus capable of providing a more constant hydrostatic head pressure to a papermaking headbox to improve the quality and consistency of the manufactured paper.
II. Background of the Invention
In the papermaking industry, an aqueous cellulosic paper stock is processed in preparation of ultimately being formed into paper by a device known as a headbox. The aqueous suspension of cellulosic papermaking stock is first cleansed of dirt and impurities, typically by hydrocyclones as a whirling annulus, and injected into elongated enclosures or wings. The hydrocyclones also facilitate deaeration by deatomizing the air molecules from the suspension by thrusting the suspension, which is formed into an annulus, against the inner wall of the deaeration wing chamber. Each of the deaeration wing chambers extend outwardly and upwardly from a large stock receiver. The chamber defined in each wing is in communication with the receiver interior such that the deaerated stock flows into the receiver to form a pool. Both the receiver and the wing chambers are maintained under a vacuum sufficient to effect deaeration of stock suspension sprayed into the wings, where the vacuum in the receiver chamber and wing chambers is substantially equal.
The pool of deaerated stock in the receiver creates a hydrostatic head. The deaerated paper stock is withdrawn from the pool through a lower port and is communicated to the papermaking headbox. The headbox subsequently manufactures paper from the deaerated and cleansed paper stock. The quality and caliper of the manufactured paper is dependent upon many factors including the quality of the papermaking stock, as well as how constant the hydrostatic head created by the pool of paper stock suspension is maintained. It is crucial that the hydrostatic head be maintained as constant as possible to reduce headbox vibration, and pressure fluctuations, both of which can degrade the quality of paper manufactured by the headbox. The more constant the pool level of deaerated stock is maintained in the receiver chamber, the more constant the resulting hydrostatic head, and hence, the higher the quality and consistency the resulting paper product.
U.S. Pat. No. 3,206,917 to Kaiser which is assigned to Clark & Vicario Corporation addresses the problem of maintaining a substantially uniform hydrostatic head of deaerated paper stock. This invention teaches a weir which is positioned in the receiver chamber to define both a pool of deaerated paper stock, and an overflow chamber. Deaerated paper stock in excess of the amount needed to provide a predetermined hydrostatic head overflows from the pool into the overflow chamber, and is recycled and further cleansed of dirt and other impurities. A generally uniform hydrostatic head results from the pool in the receiver when the level of deaerated stock matches the height of the weir. However, the pool level in the receiver is still subject to variations due to both a standing wave and splashing generated by the deaerated stock rushing from each of the inclined wings into the receiver. Deaerated stock comes rushing down each of the wings into the receiver agitates the surface of the pool such that resulting fluctuations in the hydrostatic head are generated. These variations in the hydrostatic head are sensed by the papermaking headbox. Hence, even when employing a weir, the consistency and quality of the paper manufactured by the headbox is subject to degradation.
A papermaking apparatus with reduced fluctuations of the hydrostatic head created by the deaerated paper stock, including apparatuses which have weirs, is desirable to improve the quality and consistency of the manufactured paper. Further, reducing the variations of the pool level, including standing waves and splashing, will reduce the amount of deaerated paper stock which overflows into the overflow chamber, thus reducing the amount of paper stock which needs to be subsequently recleansed and further deaerated. The reduction of further processing the overflow paper stock reduces the amount of expensive deaerating chemicals required as well.
OBJECTS OF THE INVENTION
It is accordingly a principle object of the present invention to provide a papermaking apparatus capable of manufacturing paper of superior quality, having a receiver and a plurality of extending deaeration wings which is capable of maintaining a constant pool level of deaerated paper stock, and hence, a substantially uniform hydrostatic head.
It is a further object of the present invention to provide a papermaking apparatus which reduces the amount of deaerated paper stock which overflows a weir into an overflow chamber to reduce the amount of reprocessing of the overflowed paper stock.
It is still yet a further object of the present invention to provide a device which is adaptable to both new and preexisting receivers.
It is still yet a further object of the present invention to provide a papermaking apparatus capable of reducing standing waves and splashing in the receiver pool which is efficient, inexpensive and easy to manufacture.
SUMMARY OF THE INVENTION
The foregoing features and objects are achieved by providing a papermaking apparatus having a paper stock receiver including a baffle disposed proximate the outlet from each deaeration wing to reduce standing waves and splashing. The invention comprises an apparatus having a receiver housing defining a chamber therewithin for holding a suspension of paper stock as a pool. At least one wing is connected to the receiver housing and is comprised of a conduit forming a passageway which is in communication with the chamber. Each wing extends upwardly from the housing and is inclined. A suspension injecting mechanism, such as one or more hydrocyclones, is provided for each wing for injecting the suspension into the wing to facilitate deaeration. A vacuum is provided for removing air from the receiver chamber and each of the wings passageways. A baffle is disposed in the chamber proximate the outlet from each wing passageway into the receiver chamber. Each baffle reduces turbulence of the pool surface held in the receiver due to a standing wave or splashing, which would otherwise be generated absent the baffle due to the deaerated suspension rushing from the wing into the receiver. Hence, a substantially constant hydrostatic head is created by the suspension pool and presented to a papermaking headbox. The quality, caliper and consistency of the paper made by the headbox is thus greatly improved.
Each baffle preferably has a concave surface which is positioned facing toward the respective deaeration wing passageways. Thus, suspension which is injected into the respective wing passageway flows downward toward the receiver at a high flow rate and impinges upon the concave surface of the respective baffle. The concave surface redirects the suspension downwardly into the pool surface, and converts the flow into a wide knife shape. This design inhibits the downrushing deaerated paper stock from disturbing the pool surface of paper stock residing in the chamber of the receiver housing. The baffle preferably comprises an arcuate shaped sheet of stainless steel forming a concave surface. A pair of L-shaped side plates with curved upper legs are affixed to each end of the arcuate sheet, with the lower legs extending away from the concave surface. The legs of each side plate are subsequently attached to the inner wall of the receiver at each side of the opening defined by the respective wing. An opening is defined by each side plate between the respective upper and lower legs, and the receiver sidewall. Each opening allows escape of air or other non-condensible gasses which might otherwise become entrained below the surface of the pool by the downrushing paper stock. The lower end of the arcuate plate, and the lower leg of each side plate, are positioned below the surface of the suspension pool surface in the receiver such that the deaerated suspension from each wing is dispensed in a knife and planar shape beneath the surface of the suspension pool. Further, each baffle preferably comprises a cylindrical rigid bar affixed upon the top of the baffle with a length equal to the inner diameter of the respective wing. The bar prevents the stapling of the pulp fibers of the paper stock suspension, wherein stapling is defined as the "hanging over" of fibers on what would otherwise be a thin edge presented to the incoming flow.
BRIEF DESCRIPTION THE DRAWINGS
FIG. 1 illustrates a side sectional view of a papermaking deaeration apparatus including a stock receiver, and a plurality of inclined wings having a passageway communicating with the receiver chamber and extending outward therefrom. A baffle is provided adjacent the opening of each wing into the receiver chamber;
FIG. 2 illustrates a top view of the papermaking apparatus illustrating the plurality of wings extending from the receiver, wherein the baffles are represented by hidden lines proximate the primary wings;
FIG. 3 illustrates a side view of the papermaking apparatus with the wings removed illustrating the baffle openings and bar; and
FIG. 4 illustrates a perspective view of one baffle showing the concave surface, the L-shaped side plates which are affixed to the inner wall of the receiver each side of the wing opening, and a round bar extending laterally across and above the baffle.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a side sectional view of a paper stock deaeration apparatus is generally shown at 10. Apparatus 10 comprises a large cylindrical receiver tank 12 manufactured from stainless steel, and which defines a receiver chamber 14 therein. A plurality of tubular deaeration wings 16 securely connected to tank 12 and define a respective passageway 17. Each passageway 17 extends from receiver 12 and is in communication with chamber 14. Each wing 16 extends slightly upwardly and is inclined with respect to receiver 12. Receiver 12 is structurally supported by a support structure 18, and each wing 16 is supported by a plurality of respective supporting structures 20.
A suspension of papermaking stock which is to be deaerated by apparatus 10 is typically diluted with water, which is suitably white water. The suspension is pumped through conduits to a primary cleaning stage header (not shown) which is provided with a number of laterally extending branches 22 through which the stock suspension is delivered to a plurality of cleaners 24 making up the primary cleaning stage. Each primary cleaner 24 is comprised of a centrifugal solids separating means, such as a hydrocyclone. A plurality of hydrocyclones 24 are arranged in pairs at laterally spaced locations along the length of the wings 16 The accepts outlets of the hydrocyclones 24 are connected to individual inlet pipes 30 having termini which extend into and terminate within the respective wings. A whirling annulus comprising the accepts fraction travels upwardly through the inlet pipes 30, and is explosively discharged from the termini of the inlet pipes 30 as a forceful spray against the upper inner surface of the respective wings 16.
Additional advantages are obtained by positioning the inlet pipes 30 so that the spray impinges on the interior upper surfaces of the wings 16 in order to promote the breaking up of the droplets, known as deatomizing, and consequently improve deaeration of the suspension. The chamber 17 defined by each wing 16, which is in communication with chamber 14 of receiver 12, is maintained under a vacuum sufficient to effect deaeration of the paper stock suspension sprayed thereinto. The vacuum is applied at an upper port 34 of receiver 12, and is sufficient to effect deaeration of stock suspension sprayed thereinto, the vacuum in the chamber 14 and passageways 17 being of substantially equal value. The vacuum is maintained by a booster ejector, a condenser, and a vacuum pump (not shown) which is connected to chamber 14 of receiver 12 at port 34. The degree of vacuum within the system 10 is prescribed in U.S. Pat. No. 2,614,656, which is hereby incorporated by reference.
The deaerated paper stock suspension which is injected into each wing 16 subsequently flows downward from respective passageway 17 into chamber 14 of receiver 12, and forms a pool of deaerated paper stock suspension illustrated at 36. The level of pool 36 is defined and maintained by a weir 38. Excess deaerated paper stock suspension overflows weir 38 into an overflow chamber 39 (see FIG. 2), and is recycled and recleaned in secondary cleaning stages, similar to the primary cleaning stages previously described. Deaerated paper stock suspension 36 is dispensed from receiver 12 through a lower outlet 37 into a conduit and is communicated to a papermaking headbox (not shown). Paper is subsequently manufactured by the headbox from the deaerated and cleansed paper stock suspension in a well known manner. The papermaking apparatus described thus far is well known in the art, and is also described in U.S. Pat. No. 3,538,680 and is hereby incorporated by reference.
According to the preferred embodiment of the present invention, an improved papermaking deaeration apparatus will now be described in considerable detail. Still referring to FIG. 1, a stainless steel baffle member 40 is fixedly attached to the inner wall of receiver 12 in a four-point arrangement. Each baffle 40 is located proximate the opening of the respective passageway 17 communicating with chamber 14. Baffle 40 is preferably secured via welding techniques which are well known in the art. One primary purpose of each baffle 40 is to reduce surface turbulence of suspension 36 caused by the incoming rushing deaerated paper stock which empties from the respective wing 16 into receiver 12. Large flow rates in the order of 8500 gallons per minute from each wing 16 are common in the industry. The downrushing deaerated paper stock impinges upon a concave surface 42 of baffle 40 and is redirected downwardly into pool 36 of receiver 12 below the pool surface. Hence, the downrushing deaerated paper stock does not rush directly into pool 36, and baffle 40 prevents the generation of splashing, as well as a standing wave, from forming. Hence, a calm surface of deaerated paper stock forming pool 36 in chamber 14 is facilitated. Passageway 37 subsequently communicates the deaerated paper stock to the headbox (not shown), and a constant pressure head is facilitated.
Referring to FIGS. 1 and 4, baffle 40 is comprised of an arcuate sheet of stainless steel extending between and securely attached to a pair of L-shaped side plates 44. Sheet 41 defines a concave front surface 42 and a rear convex surface 43, wherein concave surface 42 faces towards the wing chamber 17. It is recognized, however, that any shaped member having a concave surface is suitable. All structures of baffle 40 are highly polished after fabrication and installation, including all welds, to prevent any tendency of an otherwise rough surface to promote agglomeration of fibers. Each side plate 44 has a straight first leg 46 terminating at a distal end. The distal end of each leg 46 has an arcuate surface of a radius equal to the radius of the large receiving tank 12. Thus, the distal end of each leg 46 mates in a flush manner with the inner wall of receiver 12. The surfaces are subsequently welded together to secure the baffle 40 to the inner wall of receiver 12 at a pair of first points, identified at "A", located below the outlet from passageway 17. Preferably, legs 46 are attached at a point 10 inches below the top level of pond 36, however, limitation to this dimension is not to be inferred. Each plate 44 also has an upper arcuate shaped second leg 48. Each leg 48 also has a distal end having arcuate surface of radius equal to the radius of the large receiving tank 12. Each distal end of leg 48 is also welded to the inner surface of tank 12, identified at "B", at each side of the opening to passageway 17, about the diameter, to provide a pair of second fastening points. Thus, a four-point arrangement is provided such that baffle 40 remains secured to the inner wall of receiver 12 while the downrushing stock impinges concave surface 42. Each baffle 40 further comprises a elongated rigid bar 50 extending across the top surface of baffle 40 to prevent a stapling effect of the paper stock suspension. Bar 50 has a length equal to the inside diameter of passageway 17, and extends outwardly from baffle 40 into passageway 17 across the opening. Stapling is defined as the "hanging over" of fibers on what would otherwise be a thin edge presented to the incoming flow.
A baffle 40 is provided for each primary wing comprising apparatus 10. Each baffle 40 deflects the downrushing deaerated paper stock discharging from each wing 16 at a high velocity and high volume flow such that the deaerated paper stock is converted from a stream with a sectional circular cross-section, to a flat fan shape and "knifed" into pool 36 at a high angle. Turbulence of pool 36 is greatly reduced, and a large standing wave normally generated by the symmetrically arranged opposing primary wings on the surface of pool 36 is eliminated. As a result, less paper stock will overflow from pool 36 into overflow chamber 40. Consequently, the primary cleaner supply pump (not shown) is operated at a considerably lower flow, away from cavitation, and consumption of deaeration chemicals is also reduced.
Further, since static head pressure in a liquid is directly proportional to its depth, pressure pulsations generated in receiver 12 by a varying level of pool 36 is reduced. Consequently, no pressure pulsations will be sensed at the paper machine headbox due to the liquid-full connection which exists between pool 36 and the headbox, which may or may not include a headbox supply pump. The reduced hydraulic pulsations and mechanical vibrations at the machine headbox are reduced such that the quality, consistency and caliper of the produced paper is improved. Since the overflow of stock 36 is reduced, the primary cleaner supply pump (not shown) is no longer operated at an excessively high flow. Hence, the liquid traffic through the deaeration system can more accurately be maintained around predetermined designed values. The deaeration efficiency of the overall apparatus 10 is improved, and the consumption of expensive deaeration chemicals which promote air removal is reduced as well.
Referring to FIG. 2, a top view of deaeration apparatus 10 is illustrated. As shown, four primary wings 16 are provided with a respective baffle 40 positioned proximate the outlet of each passageway 17 into chamber 14. Also shown is a pair of secondary wings 60, which are well known in the art. Pool 36 extends to proximate the openings into passageways 17 of each of the four primary wings 16 wherein weir 38 establishes the level of pool 36. The deaerated paper stock suspension which overflows weir 38 is collected into overflow chamber 39. The overflowed deaerated paper stock is subsequently routed via passageway 35 for subsequent cleaning to secondary cleaners, which are also comprised of hydrocyclones, such as hydrocyclone 24. Again, the present invention reduces the amount of deaerated paper stock which overflows weir 38 and which needs to be subsequently reprocessed. As shown in FIG. 2, each baffle 40 extends about a quarter of the way into chamber 14.
Referring to FIG. 3, a side view of apparatus 10 is shown illustrating air being removed via port 34 by a vacuum pump (not shown). Referring back to FIG. 1, the upper level of the deaerated paper stock entering baffle 40 remains below the upper surface of passageway 17 proximate chamber 14 such that air can communicate from within passageway 17 to chamber 14, and the vacuum pump can remove air from both chamber 14 and passageway 17. Hence, pressure is substantially equal in both chambers 17 and 14. As shown in FIG. 3, baffle 40 extends upwardly to about a mid-line well above the level of the entering paper stock, and extends across the diameter of the opening formed by passageway 17 of wing 16 emptying into and communicating with chamber receiver 12. Bar 50 has a length equal to the inside diameter of the passageway opening.
Referring to FIG. 4, a more detailed perspective view of baffle 40 adapted to the inner wall of receiver 12 proximate the respective wing opening from wing 17 is shown. FIG. 4 illustrates baffle 40, comprising plate 41 having the concave shaped inner surface 42 which is impinged by the downrushing deaerated paper stock from respective wing 16, and side plates 44. Side plates 44 are comprised of stainless steel plate serving as braces to provide structural integrity of baffle 40, and to guide the flow of paper stock toward surface 42. Baffle plate 41 has a beveled rim surface 52 which tapers outwardly to stiffen the outlet end of curved plate 41. As shown, rod 50, which is preferably comprised of stainless steel, extends along a mid-section of baffle 40 across the diameter of the wing opening, and is welded at each end to the top of baffle plate 41 at "C". Again, rod 50 prevents a stapling effect of deaerated paper stock over the top of baffle 40. Also shown in FIG. 4, is the wide open area provided between the wing passageway 17 opening, the side of receiver 12, and the concave surface 42 of baffle 40 directly below bar 50. Also shown is a pair of openings 54 formed by the respective L-shaped side plates 44 on each side of the passageway 17 opening. Openings 54 allow the escape of air or other non-condensible gasses which might otherwise become entrained below the surface of the pool 36 by the downrushing paper stock. This design thus enhances the deaeration process. Again, each leg 46 is welded to the sidewall of receiver 12 at "A" slightly below the opening of passageway 17, communicating with chamber 14, and each of the distal ends of the arcuate shaped legs 48 is welded at "B" at opposite sides of the opening into passageway 17.
A cut 62 is provided in both plate 41 and each side plate 42 to render each baffle 40 into small enough pieces (2) to pass through the manway (not shown) that typically comprises the only convenient access into chamber 36 for their installation in existing apparatus 10. The cut is welded along the edges at "D" after baffle installation. This cut 62 would not be required in new factory fabrications.
This invention has been described herein in considerable detail in order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention ca be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment details and operating procedures, can be accomplished without departing from the scope of the invention itself.
In the claims: | A papermaking deaeration apparatus including a receiving chamber, and a plurality of cleaning and deaeration wings extending therefrom. A baffle is provided in the chamber of the receiver proximate the opening of each wing which communicates deaerated paper stock into the receiver chamber. The baffles redirect downrushing deaerated paper stock such that it is dispensed in a "knifing shape" into the pool of paper stock contained in the chamber of the receiver. Hence, standing waves and splashing in the pool of paper stock in the receiver is reduced. The static pressure head created by the pool of paper stock is more uniform such that fluctuations in the static head are reduced. Mechanical vibrations which can reach the paper machine headbox and the primary cleaner supply pump are reduced such as the quality, consistency and caliper of the paper manufactured by the headbox is improved. Each baffle has a concave surface facing inward towards the wing chamber to cause conversion of the downrushing deaerated paper stock into a wide thin knife shape before entering the receiver chamber. The deaerated paper stock is deflected by the baffle downward into the receiver chamber below the surface of the pool. | 3 |
TECHNICAL FIELD
[0001] This disclosure relates generally to optics, and in particular but not exclusively, relates to high dynamic range image sensors.
BACKGROUND INFORMATION
[0002] High dynamic range (“HDR”) image sensors are useful for many applications. In general, ordinary image sensors, including for example charge coupled device (“CCD”) and complementary metal oxide semiconductor (“CMOS”) image sensors, have a dynamic range of approximately 70 dB dynamic range. In comparison, the human eye has a dynamic range of up to approximately 100 dB. There are a variety of situation in which an image sensor having an increased dynamic range is beneficial. For example, image sensors having a dynamic range of more than 100 dB are needed in the automotive industry in order to handle different driving conditions, such as driving from a dark tunnel into bright sunlight. Indeed, many applications may require image sensors with at least 90 dB of dynamic range or more to accommodate a wide range of lighting situations, varying from low light conditions to bright light conditions.
[0003] One known approach for implementing HDR image sensors is to use a combination of a photodiodes in each pixel. One of the photodiodes can be used to sense bright light conditions while another photodiode can be used to sense low light conditions. In this approach, the photodiode used to sense bright light is typically smaller (having a smaller light exposure area) than the photodiode used to sense low light conditions. However, this approach requires an asymmetric layout that tends to increase costs. In addition to increasing cost, asymmetric fabrication of the photodiodes in each pixel includes optical asymmetry that may introduce image light ray angle separation. Image light ray angle separation can cause asymmetric blooming, crosstalk, and other undesirable effects, especially when the image light is angled relative to the face of the image sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
[0005] FIG. 1 is a block diagram schematic illustrating one example of an HDR imaging system, in accordance with an embodiment of the disclosure.
[0006] FIG. 2 is a schematic illustrating one example of an HDR pixel that can be implemented in the HDR image sensor illustrated in FIG. 1 , in accordance with an embodiment of the disclosure.
[0007] FIG. 3 is a plan view of one example of an image sensor pixel that includes a large sub-pixel and a small sub-pixel, in accordance with an embodiment of the disclosure.
[0008] FIG. 4 is a plan view of one example of an image sensor pixel that includes a large sub-pixel and a small sub-pixel, in accordance with an embodiment of the disclosure.
[0009] FIG. 5 is a plan view of one example of a pixel group that includes image sensor pixels that include a large sub-pixel and a small sub-pixel, in accordance with an embodiment of the disclosure.
DETAILED DESCRIPTION
[0010] In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.
[0011] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0012] FIG. 1 is a block diagram schematic illustrating one example of an HDR imaging system 100 , in accordance with an embodiment of the disclosure. HDR imaging system 100 includes an example pixel array 102 , control circuitry 108 , readout circuitry 104 , and function logic 106 . As shown in the depicted example, HDR imaging system 100 includes pixel array 102 which is coupled to control circuitry 108 and readout circuitry 104 . Readout circuitry 104 is coupled to function logic 106 . Control circuitry 108 is coupled to pixel array 102 to control operational characteristics of pixel array 102 . For example, control circuitry 108 may generate a shutter signal for controlling image acquisition. In one example, the shutter signal is a global shutter signal for simultaneously enabling all pixels within pixel array 102 to simultaneously capture their respective image data during a single acquisition window. In another example, the shutter signal is a rolling shutter signal such that each row, column, or group of pixels is sequentially enabled during consecutive acquisition windows.
[0013] In one example, pixel array 102 is a two-dimensional (2D) array of imaging sensors or pixels 110 (e.g., pixels P1, P2 . . . , Pn). In one example, each pixel 110 is a CMOS imaging pixel including at least a large sub-pixel and a small sub-pixel. The large sub-pixels and the small sub-pixels in the pixel array may receive separate shutter signals. As illustrated, each pixel 110 is arranged into a row (e.g., rows R1 to Ry) and a column (e.g., column C1 to Cx) to acquire image data of a person, place, object, etc., which can then be used to render an image of the person, place, object, etc.
[0014] In one example, after each pixel 110 has acquired its image data or image charge, the image data is read out by readout circuitry 104 through readout columns 112 and then transferred to function logic 106 . In various examples, readout circuitry 104 may include amplification circuitry, analog-to-digital (ADC) conversion circuitry, or otherwise. Function logic 106 may simply store the image data or even manipulate the image data by applying post image effects (e.g., crop, rotate, remove red eye, adjust brightness, adjust contrast, or otherwise). In one example, readout circuitry 104 may read out a row of image data at a time along readout column lines (illustrated) or may read out the image data using a variety of other techniques (not illustrated), such as a serial read out or a full parallel read out of all pixels simultaneously. The image charge generated by the large sub-pixel and the small sub-pixel may be read out separately during different time periods.
[0015] FIG. 2 is a schematic illustrating one example of an HDR pixel 210 that can be implemented as pixel(s) 110 in HDR imaging system 100 , in accordance with an embodiment of the disclosure. Pixel 210 includes a small sub-pixel 275 and a large sub-pixel 285 . Small sub-pixel 275 includes a transfer transistor 233 (T1 A ) and a first photodiode 235 (PD A ) disposed in a semiconductor material (e.g. silicon). Transfer transistor 233 is coupled between shared floating diffusion region 229 and first photodiode 235 . Large sub-pixel 285 includes a plurality of photodiodes that includes photodiodes 245 (PD B ), 255 (PD C ) . . . and 295 (PD ω ), where ω represents the number of photodiodes in large sub-pixel 285 . Large sub-pixel 285 also includes transfer transistors 243 (T1 B ), 253 (T1 C ) . . . and 293 (T1 ω ), where ω still represents the number of photodiodes and corresponding transfer transistors in large sub-pixel 285 . Transfer transistors 243 (T1 B ), 253 (T1 C ) . . . and 293 (T1 ω ) are coupled between their respective photodiodes 245 (PD B ), 255 (PD C ) . . . and 295 (PD ω ) and shared floating diffusion region 229 .
[0016] Image light incident on pixel 210 will generate image charge in each of the photodiodes PD A through PD ω . First image charge is generated in first photodiode 235 PD A . When transfer transistor 233 T1 A receives a first transfer signal TX S 231 at its transfer gate, the first image charge is transferred to shared floating diffusion region 229 . Photodiodes PD B through PD ω in large sub-pixel 285 will also generate image charge in response to incident image light. Collectively, the image charge generated by the photodiodes in large sub-pixel 285 will be referred to as “distributed image charge” as it is distributed among the photodiodes, at least initially. When transfer transistors T1 B -T1 ω receive second transfer signal TX L 241 at their transfer gates, the distributed image charge from each photodiode in the plurality of photodiodes in large sub-pixel 285 is transferred to shared floating diffusion region 229 . As FIG. 2 illustrates, transfer transistors T1 B -T1 ω all receive a common transfer signal (TX L 241 ). In one embodiment (not illustrated), the transfer transistors T1 B -T1 ω share a physically consolidated transfer gate which reduces the need for trace routing. Even in the illustrated embodiment, because they are electrically connected to receive a common transfer signal TX L 241 , the transfer gates of the transfer transistors T1 B -T1 ω may be described as one transfer transistor having sub-gates coupled between shared floating diffusion region 229 and each photodiode PD B through PD ω .
[0017] The first image charge that accumulates in first photodiode PD A is switched through transfer transistor T1 A 233 into shared floating diffusion region 229 in response to a control signal TX S being received on a first transfer gate of transfer transistor T1 A 233 . The distributed image charge that accumulates in the plurality of photodiodes PD B through PD ω is switched through a second transfer transistor (which may include transfer gates of transfer transistors T1 B -T1 ω coupled together) into shared floating diffusion region 229 in response to control signal TX L being received on the second transfer gate of the second transfer transistor. It is understood that shared floating diffusion region 229 may be a physical combination of the drains of transfer transistors T1 A -T1 ω .
[0018] As shown in the example, pixel 210 also includes an amplifier transistor T3 224 that has a gate terminal coupled to shared floating diffusion region 229 . Thus, in the illustrated example, the image charge from small sub-pixel 275 and large sub-pixel 285 are separately switched to shared floating diffusion region 229 , respectively, which shares the same amplifier transistor T3 224 . In one example, amplifier transistor T3 224 is coupled in a source follower configuration as shown, which therefore amplifies an input signal at the gate terminal of amplifier transistor T3 224 to an output signal at the source terminal of amplifier transistor T3 224 . As shown, row select transistor T4 226 is coupled to the source terminal of amplifier transistor T3 224 to selectively switch the output of amplifier transistor T3 224 to readout column 212 in response to a control signal SEL. As shown in the example, pixel 210 also includes reset transistor T2 222 coupled to shared floating diffusion region 229 , which may be used to reset charge accumulated in pixel 210 in response to a reset signal RST. In one example, the charge accumulated in shared floating diffusion region 229 can be reset during an initialization period of pixel 210 , or for example each time after charge information has been read out from pixel 210 and prior to accumulating charge in small sub-pixel 275 and large sub-pixel 285 for the acquisition of a new HDR image in accordance with the embodiments of the disclosure.
[0019] In one embodiment, each photodiode PD B through PD ω is substantially identical to the first photodiode PD A 235 . For example, each photodiode PD B through PD ω may have the same charge capacity and other electrical characteristics as PD A . This may reduce or eliminate the need to compensate for physical differences that impact the electrical function of the photodiodes. For example, some HDR pixel configurations include a single physically larger photodiode as a large sub-pixel. However, these singular physically larger photodiodes serving as a large sub-pixel often suffer higher lag, which can negatively influence the image charge transferred and the timing of the transfer. Furthermore, a singular physically larger photodiode as the large sub-pixel also introduces optical asymmetry that can introduce undesirable artifacts. In contrast, the photodiodes in large sub-pixel 285 being substantially identical to first photodiode PD A 235 , allows image charge to transfer out of each photodiode PD B through PD ω with essentially the same electrical characteristics as PD A 235 , while still leveraging the increased semiconductor size for capturing image light by utilizing multiple photodiodes PD B through PD ω . These shared electrical characteristics may reduce lag time in the transfer of image charge from the large sub-pixel. The optical artifacts (e.g. crosstalk, ray angle separation) associated with the singular physically large photodiode are also mitigated as each photodiode in the plurality of photodiodes PD B through PD ω are substantially identical.
[0020] FIG. 3 is a plan view of one example of an image sensor pixel 310 that includes a large sub-pixel 385 and a small sub-pixel 275 , in accordance with an embodiment of the disclosure. The plan view illustrated in FIG. 3 is one example layout of image sensor pixel 210 . Image sensor 310 includes three photodiodes PD B 245 , PD C 255 , and PD D 265 in large sub-pixel 385 . The three photodiodes PD B 245 , PD C 255 , and PD D 265 and photodiode PD A 235 in small sub-pixel 275 are evenly spaced in a symmetrical pattern that is both vertically and horizontally symmetric.
[0021] FIG. 3 also illustrates transfer gates 234 , 244 , 254 , and 264 , which are the transfer gates of transfer transistors 233 , 243 , 253 , and 263 , respectively. In one embodiment (not illustrated), transfer gates 244 , 254 , and 264 are physically consolidated. Although the electrical connection is not illustrated in FIG. 3 , transfer gates 244 , 254 , and 264 are all coupled to receive transfer signal TX L 241 and transfer gate 234 is coupled to receive transfer signal TX S 231 . Each transfer gate is for transferring image charge from its respective photodiode to shared floating diffusion region 229 . Shared floating diffusion region 229 is wired (via a trace) to the gate terminal of amplifier transistor T3 224 , which may be coupled as a source follower (“SF”). Reset transistor T2 222 is coupled to reset shared floating diffusion region 229 . Select transistor T4 226 is coupled to transfer an amplified image signal from amplifier transistor T3 224 to readout column 212 .
[0022] FIG. 4 is a plan view of one example of an image sensor pixel 410 that includes a large sub-pixel 485 and small sub-pixel 275 , in accordance with an embodiment of the disclosure. The plan view illustrated in FIG. 4 is one example layout of image sensor pixel 210 . Image sensor pixel 410 includes fifteen photodiodes (PD B -PD P ) in large sub-pixel 485 . FIG. 4 shows that embodiments of this disclosure can include different numbers of photodiodes in the plurality of photodiodes that are included in large sub-pixel 285 . In FIG. 3 , three photodiodes are included in the plurality of photodiodes. In FIG. 4 , fifteen photodiodes are included in the plurality of photodiodes. In different embodiments, the plurality of photodiodes may include two or more photodiodes.
[0023] In FIG. 4 , the shaded triangles represent the transfer gates corresponding to their respective photodiodes, similar to FIG. 3 . Although not illustrated, the transfer gates corresponding to the fifteen photodiodes in large sub-pixel 485 are coupled to receive a common transfer signal (e.g. TX L 241 ) to transfer the distributed image charge from the fifteen photodiodes, while the transfer gate corresponding to first photodiode PD A 235 is coupled to receive transfer signal (e.g. TX S 231 ) to transfer the first image charge from the first photodiode 235 . Shared floating diffusion region 429 A is wired (via a trace) to the gate terminal of amplifier transistor T3 224 , which may be coupled as a source follower (“SF”). The gate terminal of amplifier transistor T3 224 is also coupled to shared floating diffusion regions 429 B, 429 C, and 429 D, in FIG. 4 . Since shared floating diffusion regions 429 A, 429 B, 429 C, and 429 D are physically wired together, they may be referred to as a local floating diffusion regions that are electrically coupled together to form a combined shared floating diffusion region. Reset transistor T2 222 is coupled to reset shared floating diffusion regions 429 A, 429 B, 429 C, and 429 D. Select transistor T4 226 is coupled to transfer an amplified image signal from amplifier transistor T3 224 to readout column 212 . In FIG. 4 , layout space is saved having only three transistors ( 222 , 224 , and 226 ) serving to transfer the image signal to the readout column 212 .
[0024] FIG. 5 is a plan view of one example of a pixel group 500 that includes image sensor pixels 310 that include large sub-pixels 585 and small sub-pixels 575 , in accordance with an embodiment of the disclosure. Pixel group 500 includes four image sensor pixels 310 (as illustrated in FIG. 3 ) arranged in a Red, Green, Green, Blue (“RGGB”) Bayer pattern.
[0025] In FIG. 5 , small sub-pixel 575 A includes first photodiode PD A which is disposed under a red filter that passes red light but that substantially filters out other wavelengths of light from becoming incident on photodiode PD A . Large sub-pixel 585 A includes photodiodes PD B -PD D which are also disposed under a red filter that passes red light but that substantially filters out other wavelengths of light from becoming incident on photodiodes PD B -PD D . Similarly, small sub-pixel 575 B and 575 C along with large sub-pixels 585 B and 585 C are disposed under green filters, while small sub-pixel 575 D and large sub-pixel 585 D are disposed under blue filters, forming a Bayer pattern. Pixel group 500 may be repeated to form an HDR RGGB image sensor, in accordance with embodiments of the disclosure.
[0026] In the disclosed embodiments of this disclosure it is appreciated that the first photodiode PD A and the plurality of photodiodes PD B -PD ω are included in an HDR image sensor that is capable of capturing an HDR image in a single frame. In other words, the first photodiode PD A and the plurality of photodiodes PD B -PD ω are able to accumulate image charge in overlapping time periods. First photodiode PD A may be designed to capture bright light image data while the plurality of photodiodes PD B -PD ω are designed to capture low light image data. The first image charge from first photodiode PD A is read out separately from the distributed image charge from the plurality of photodiodes PD B -PD ω to generate a bright light signal. The distributed image charge from the plurality of photodiodes PD B -PD 107 is read out separately from the first image charge to generate a low light signal. The bright light signal and the low light signal can be utilized by HDR algorithms to generate an HDR image.
[0027] The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
[0028] These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation. | An image sensor pixel for use in a high dynamic range image sensor includes a first photodiode, a plurality of photodiodes, a shared floating diffusion region, a first transfer gate, and a second transfer gate. The first photodiode is disposed in a semiconductor material. The first photodiode has a first light exposure area and a first doping concentration. The plurality of photodiodes is also disposed in the semiconductor material. Each photodiode in the plurality of photodiodes has the first light exposure area and the first doping concentration. The first transfer gate is coupled to transfer first image charge from the first photodiode to the shared floating diffusion region. The second transfer gate is coupled to transfer distributed image charge from each photodiode in the plurality of photodiodes to the shared floating diffusion region. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 10/914,026, filed on Aug. 9, 2004 now U.S. Pat. No. 7,051,817. The disclosure of the above application is incorporated herein by reference.
FIELD
The present disclosure relates to a device for improving oil and gas recovery in wells. It can be used in oil and gas industry for oil recovery in oil, condensate and gas fields.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
One device of this type is disclosed in U.S. Pat. No. 5,893,414. The device is formed as a tubular element which, by means of a mandrel, is hermetically fixed in tubing near an interval of perforation, and has a system of cavities which are connected with one another. An inlet cone opening is located downwardly and leads to a multi-stage system of coaxially arranged Venturi pipes above the inlet nozzle, with a gradually increasing diameter in direction of flow. From the side of the inlet of the flow into the device, it retains gas the calculated value of in a dissolved condition in oil at a predetermined calculated pressure. On the other hand, the device, accelerates the two-phase flow and creates homogenous structure of gas-liquid flow in upstream direction mouth the opening of the well.
The device has, however, some disadvantages. The multi-stage structure of the Venturi pipes leads to small swirling of the flow which can not be accurately calculated on transitions from one diameter of the pipe to the other. As such, this makes it difficult to correct and forecast energy losses of the flow, especially in a multi-phase systems, in the device. This in turn makes it impossible to forecast an optimal mode of operation of the current condition of the layer and the well, and the process of optimization of the system layer-bottomhole of the well-device-tubing-surface choke. The swirling zones in the device lead to formation of large drops of the liquid (oil-water mixture), which have a speed significantly smaller than the speed of the gas nucleus, and thereby they migrate in direction toward the wall of the tubing so as to create a ring-like mode in the inlet and flowing of the fluid down along the walls of the tubing to a bottom hole of the well. This, in turn, significantly increases the calculated pressure and therefore reduces efficiency of operation of the well, so as to destabilize its operation and make the process of optimization of the well longer.
Another device is disclosed in U.S. Pat. No. 6,059,040. It includes a laval nozzle which is hermetically connected with a mandrel and is located inside it, and the mandrel in turn is fixed in a column of pipes. In the narrowest point of the laval nozzle there are horizontal openings which connect the interior of the laval nozzle with a space in the tubing above a packer of the mandrel. The device can be used in gas and gas-condensate wells for removal of a liquid phase accumulated in the bottomhole (condensate and water) by creating a zone of low pressure in the narrowest part of the laval nozzle. The low pressure in this point is created by acceleration of the gas flow. The liquid phase is entrained into the gas flow and broken into small droplets with a structure in form of fog and easily travels to the surface. In the device disclosed in this reference, difficulties take place with the mounting of the device in the mandrel, since for its normal operation it is necessary to drill horizontal openings in the mandrel, which is not possible for the majority of mandrels due to their structural features.
SUMMARY
Accordingly, it is an object of the present invention to provide a device for improving oil and gas recovery in wells. In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a device for improving recovery of hydrocarbons through a well by creating, regulating and maintaining under the device a calculated bottomhole pressure at a desired level and creating above the device a two-phase gas-liquid homogenous flow for efficient lifting of hydrocarbons to a surface, the device comprising a body having a central throughgoing opening with a shape corresponding a shape of a laval nozzle and with a cross section which changes steplessly and gradually; and a mandrel attachable to a tubing and associated with said body without interfering with a flow of fluids.
When the device is designed in accordance with the present invention, it allows more accurate calculations for optimization of productivity of oil-gas wells during current conditions of a joint operation of a working system layer-well.
When the device is designed in accordance with the present invention, automatic regulation of a gas-liquid flow in the device is achieved so as to provide a stable operation of the well in frequently changing conditions of operation of an interfering system of the wells, which work with a particular layer, as well as the condition of the layer within the wide range of pressures, productivity and time.
With the use of the device, a more stable multi-dispersed structure of a two-phase gas-liquid flow is created above the device and it moves to an outlet of the well in a bubble mode without deterioration into a gas-liquid, so as to reduce weight of a mixture density and to prevent formation of a ring-like mode which negatively affects the productivity of the well.
With the inventive device, parameters of the device can be calculated accurately for operation together with an outlet nipple for a smooth regulation of the system: well-bottomhole-device-tubing-outlet nipple for speedy optimization of the well in correspondence with the current condition of the layer.
Also, the device can be arranged with horizontal openings so that it enhances the most efficient withdrawal of liquid from the bottomhole of gas and gas-condensate wells.
In one embodiment, a well device is provided which is configured to be installed through well tubing into a landing nipple of the well. The device has a member defining a laval nozzle and a coupling portion fluidly coupled to the laval nozzle. A plurality of sealing members are provided which are annularly disposed about the coupling portion. The sealing members are adapted to resist movement of the coupling member with respect to the landing nipple.
In another embodiment, a well construction is provided. The Well construction has well tubing having a through bore with a first inner diameter. A landing nipple is provided which defines a second through bore having a second inner diameter smaller than the first inner diameter. The construction further has a well device having, a member defining a laval nozzle, a coupling member defining third through bore fluidly coupled to the laval nozzle. The coupling member has a plurality of compressible sealing members configured to fluidly seal the second through bore and support the coupling member in the landing nipple. The member defining the laval nozzle is disposed outside of the landing nipple.
In another embodiment, a device for improving recovery of hydrocarbons from a well is provided. The device has a body defining a central throughbore with a shape corresponding to a laval nozzle having a cross-section which is changed steplessly and gradually. A coupling mechanism is provided which is coupled to the body. The body is configured to couple the body to a well landing nipple and is located outside said well landing nipple.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
FIG. 1 is a view schematically showing a device for improving recovery of oil and gas in accordance with the present invention;
FIG. 2 is a view showing another embodiment of the device composed of several parts;
FIG. 3 is a view showing the installation of the inventive device in a well;
FIG. 4 is a view showing the installation of a second arrangement of the device in accordance with the present invention in a well above the mandrel;
FIG. 5 is a view similar to the view of FIG. 2 , but with installation under the mandrel;
FIGS. 6 a and 6 b represent cross-sectional views of FIG. 5 with a further modification of the inventive device;
FIGS. 7 a and 7 b represent perspective views of the well device according to the teachings of the present invention;
FIG. 8 represents a close-up side view of the well device installed within a well construction;
FIGS. 9-13 represent cross-sectional views of the well device shown in FIG. 8 ;
FIG. 14 represents an exploded view of th well device show in FIG. 8 ;
FIGS. 15 a - 15 d represent perspective and sectional views of the laval nozzle subassembly used in the well device;
FIGS. 16 and 17 depict the installation of the well device shown in FIG. 8 ;
FIGS. 18 a and 18 b represent cross-sectional views of the well device installed within a landing nipple;
FIGS. 19 a and 19 b represent cross-sectional views of a functioning well device according to the teachings of the present invention; and
FIG. 20 represents the installation of the well device shown in FIG. 8 .
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
A device in accordance with the present invention is shown in FIG. 1 and identified as a whole with reference numeral 1 . It has a body 2 with a central throughgoing opening 3 . The body 2 has a solid, impermeable wall without holes. The throughgoing opening 3 has the shape of laval nozzle. It has a cross-section which changes in an axial direction smoothly, without steps. The opening 3 has two substantially conical parts 4 and 5 which are connected with one another at their narrowest locations 6 .
An inlet part 4 of the opening 3 is shorter and it is generally identified as a confuser, while the outer portion 5 is longer and is usually identified with a diffuser. The size of the portions 4 and 5 of the inner opening 3 depends on current parameters of the layer (layer pressure, current pressure of saturation, gas content, water content, porosity, permeability, density of oil, water, gas, etc), and also on parameters of operation of the well (around the clock production, the nature of production oil, water, gas, condensate), an inlet pressure, a size of an inlet nozzle, a pressure in a line, a pressure in a separator, etc.
Based on these parameters, with the use of computer program a specific design of the device is calculated with corresponding sizes, in accordance with which the device is produced.
The device is fixed to mandrels of different types, and with the mandrel it is lowered to a desired calculated depth as close as possible to an interval of perforation. It is fixed and kept hermetically closed by means of mandrel packers and kept in this position to provide the device operation.
When the efficiency of the device is reduced due to significant natural changes in the parameters of the layer, a new device is calculated and made which correspond to new current parameters of the operation of the system the layer-well, and the new device by the mandrel and known means is lowered and replaced the old one.
While in FIG. 1 the device is shown as an integral, single piece part, it can be composed of several parts as shown in FIG. 2 . The parts of the device which are identified with reference numerals 7 , 8 , 9 , can be connected with one another by known means, for example by thread 10 . Such a device can be easier and simpler to manufacture.
FIG. 3 shows an arrangement of the device in the well and its connection with tubing by means of a mandrel. Reference numeral 11 identifies the tubing, reference numeral 12 identifies a mandrel of any type, reference numeral 13 identifies a gripper mechanism of the mandrel, and reference numeral 14 identifies a packer of the mandrel. The body 2 is located below the mandrel 12 . The device improves production of oil and gas condensate.
When the device is used for removal of liquid from the bottomhole of gas and gas-condensate wells, the body with horizontal openings 15 is mounted above the mandrel, as shown in FIG. 4 , or it is arranged at the end of the tubing without the mandrel by means of another element.
In a further embodiment shown in FIG. 5 the body 2 with the horizontal openings 15 is located below the mandrel and a packer 16 for mounting of the mandrel is provided with a vertical passage 17 formed for example as a longitudinal opening through which liquid and gas condensate can pass and then passing through the horizontal openings.
This device can be installed without these longitudinal opening, also depending on flow conditions.
FIG. 6 shows the cross-section (of packer A-A and horizontal holes B-B) of the second arrangement of the device.
The inventive device generates a completely homogenous gas-liquid flow in a well due to elimination of the stepped zones in a system of Venturi pipes, which create sources of swirling with resulting energy losses. The parameters of the device calculated from current data of the layer and the well can provide accurate forecast without deviations from real conditions of the regulating process and optimization of the system layer-well by the device and the inlet nozzle. The elements of automatic regulation of the bottomhole device are used fuller, a mono-dispersed structure is provided for the gas-liquid flow and it can move toward the inlet of the well without deterioration into gas and liquid, and annular regime mode is not formed. Efficiency of recovery and time of operation of the well with the device significantly increases, so as to increase daily productions of oil and a coefficient of oil recovery as a whole. Liquid is removed from the bottomhole of the well fast and efficient and, therefore, productivity of gas and gas-condensate wells are increased due to reduction of bottomhole pressure to a calculated level.
The advantages of the device in accordance with the present invention can be clearly understood from comparison of a hydraulic calculation of the known apparatus with seven Venturi pipes and a new apparatus, with identical inlet and outlet openings, the total length and length of the narrowest part of the device, with respect to the well Rodador 179 (Mexico).
The well productivity was as follows: oil-138 m 3 /day, water-56 m 3 /day or 29%, and gas 31200 m 3 /day. Bottomhole pressure was 2848 psi, the outlet pressure was 569 psi, with a diameter of the outlet nozzle 26/64, the measured layer pressure was 3020 psi. The depth of the well to the lower holes of perforation was 8423 feet. Oil density was 25 api, water 1.19, gas 0.838.
The prior device with the Venturi pipes before lowering into the well was calculated for pressure drop 107 psi, and the bottomhole pressure had to reduce the depression (difference reservoir and bottomhole pressure) by 15%. The productivity of the well had to be increased also approximately by 15%.
In actuality, after the first test, the yield of oil increased to 153 m 3 /day or in other words by 11%. The yield of gas and water reduced by 25%. However, as a result of an attempt to increase the oil recovery even more and to reduce content of water during a subsequent regulation of the well, it was not possible to go beyond the range 1/64″÷ 1.5/64″ on adjustable top chock. Negative phenomena appeared in form of a fast drop of gas volume of a main source of energy in this layer. In other words the possibility of regulation of well turned to be very limited.
A calculation of pressure drop in the device in accordance with the present invention shows a drop in the device only by 65 psi. In other words, the magnitude of local resistance in the prior art device was by 42 psi or by 39% greater than in the inventive device. This shows that the calculation for the inventive device is much more accurate The use of the device in accordance with the present invention can Increase the range of regulation at the outlet up to 5/64″÷ 6/64″, and maybe even more, which is extremely important for conditions of significant fluctuations of layer and well parameters during a long time, so as to maintain and optimize the operation of the well when the device is located in the well.
Referring generally to FIGS. 7 a - 14 , shown is a well device 40 according to an alternate embodiment. The well device 40 is configured to convert unwanted water within the well system into an atomized vapor or mist, which is transported to the surface by the hydrocarbon stream. The well device 40 has a laval nozzle 42 and a coupling device 44 that is configured to facilitate and regulate the proper installation of the laval nozzle 42 within a well. Disposed between the laval nozzle 42 and the coupling device 44 is a first interface device 46 . In this regard, the interface device 46 defines an inner threaded through bore which is configured to mate with a corresponding set of threads on an outer surface of the laval nozzle 42 . Optionally, these threads can be integrally formed within the coupling device 44 or can take the form of a separate threaded mounting portion 48 .
Disposed at a distal end of the coupling device 44 is a second interface device 50 which is configured to couple an optional filter 47 to the coupling device 44 . Centrally disposed through the laval nozzle 42 , the coupling device 44 , and the filter 47 is a through bore 60 . As described in detail below, the through bore 60 is configured to facilitate the transfer of natural gas, well products, and atomized waste water from a well bottom to the well surface.
Disposed on an exterior surface of the coupling device 44 is at least one sealing member 52 . The sealing member 52 is configured to sealably interface and lock the coupling device 44 with an interior surface of a well tube. Specifically, the sealing member 52 is configured to interface with an inner surface 59 of a landing nipple 57 . The landing nipple 57 , as traditionally known in the art, is a tube disposed within the well bottom having a smaller diameter than the tubing 58 traditionally used to extract products from the well. The sealing member 52 can be formed of deformable and compressible hydrocarbon-compatible materials. In the regard, it is envisioned the seal members 52 can be formed of metal or polymers which can withstand the environmental conditions within the well.
As shown in FIG. 8 , the sealing members 52 function to fluidly seal and lock the well device 40 into the landing nipple 57 . Above the sealing members 52 , the coupling device 44 and laval nozzle 42 have an exterior surface having a diameter which is generally smaller than the inner diameter of both the landing nipple 57 and the tube 58 . As such, an annular fluid collecting space 62 is defined between the tube 58 and the exterior surface of the device 40 . The lower portion of the collecting space 62 is sealed by the sealing members 52 .
Defined within the laval nozzle 42 is at least one fluid passage 64 , which fluidly couples the annular space 62 and a throat 66 of the nozzle 42 . As described further below, the annular space 62 functions to collect unwanted water from the well tube 58 in liquid form. The passages 64 defined in the nozzle 42 function to transport water from the annular space 62 into the throat 66 , thus allowing the atomization of the waste water by pressurized hydrocarbons through the nozzle 42 . This water vapor is then transported by the flowing hydrocarbon gas to the surface.
FIGS. 9-13 depict cross-sections of the device 40 shown in a well installation. Shown is the relative positioning of the various nozzle components with respect to the tube 58 and landing nipple 57 . As shown in FIGS. 8 , 10 , and 12 , the annular space 62 is divided into two separate portions 90 and 92 . The first portion 90 is generally below the passages 64 defined by the nozzle 42 and above the sealing members 52 . Any water captured within the annular chamber 90 between the nozzle 42 and the tube 58 is transported through the passages 64 into the throat 66 of the nozzle. FIG. 13 shows that the sealing members 52 function to completely seal and center the device 40 within the landing nipple 57 .
FIG. 14 shows and exploded view of the well device 40 . Shown is a general construction showing one possible method for positioning the sealing members 52 with respect to the coupling device 44 . Disposed between each of the sealing members 52 is a spacer ring 55 , which holds the sealing members 52 apart and prevents their transverse movement of the sealing members 52 with respect to the coupling device 44 . It is envisioned these spacer rings 55 can be integrally incorporated into the sealing members 52 .
Further shown on the top of the coupling device 44 is the coupling device mounting portion 48 . The coupling device mounted portion 48 has a threaded portion which functions to threadingly engage the laval nozzle 42 . It should be noted that, when installed, the laval nozzle 42 is generally positioned above the coupling portion 44 so as to define the annular space 62 between the device 40 and the interior surface of the tube 58 . Furthermore, the location of the laval nozzle 42 allows for the installation or extraction of the nozzle member from within the landing nipple 57 . Disposed on a proximal end of the laval nozzle 42 is a fixation mechanism 86 . The fixation mechanism 86 defines a transverse ledge 88 , which is used by an insertion tool (not shown) which is releasably coupled to the device for installation.
FIGS. 15 a - 15 b depict perspective and cross-sectional views of optional laval nozzles 42 . As previously mentioned, the exact configuration of a laval nozzle first confuser cone 80 and second diffuser cone 82 will depend on the specifics of the environmental conditions in the well bottom. In this regard, the length and curvature or angularity of the specific cones 80 , 82 will depend on specific gas parameters and loading within the well. As shown in FIGS. 15 b and 15 d , the associated coupling device 44 can either be integral with the laval nozzle 42 or can be a stand alone separate member.
FIGS. 16 and 17 depict the insertion of the well device 40 within the well construction. As can be seen, the well device 40 is inserted using an insertion mechanism 94 so as to position the sealing members 52 within the inner surface 59 of the landing nipple 57 . It is envisioned that the device 40 has a length which is longer than the length of the landing nipple 57 . As such, the filter 47 is disposed below a lower surface 72 of the landing nipple 57 . The perforated construction as well as the location of the filter 47 allows for the maximum transport of gas from the well without having to worry about the interference of excess or extraneous water found in the well bottom. The filter 47 is located both within and outside of the landing nipple 57 .
FIGS. 18 a and 18 b represent cross-sectional views of the well device 40 inserted within the well. Shown is a specific configuration and location of the various components within the system. Specific note should be directed to the location of the filter 47 with respect to the inner surface 59 of the landing nipple 57 . In this regard, an annular chamber 96 is formed so as to allow the maximum input of gas into the through bore 60 under many different well operating conditions.
FIGS. 19 a and 19 b show the functioning of the well device 40 . In this regard, the gas 98 is shown flowing through the through bore 60 . Unwanted excess water has been trapped within the annular cavity 62 by the sealing members 52 . The nozzle 42 is positioned downstream with respect to gas flow in the well from the coupling device 44 and the filter 47 . When the first chamber portion 90 of the annular space 62 fills, water is transferred into the throat 66 of the laval nozzle 42 through the passages 64 defined within the nozzle 42 . A mixture of gas 98 and atomized water 100 is pushed by the gas pressure through the nozzle second diffuser cone 82 and up to the well surface. The device 40 advantageously provides for an efficient method to remove waste water which condenses or is transported by the inner surface 76 of the tube 58 .
FIG. 20 represents the use of a wire line truck 106 to insert the well device 40 . As can be seen, a wire line 104 is coupled to the removable locking mechanism 94 . The wire line 104 is used to lower the device and, in combination with gravity, to insert the device within the landing nipple. Weights are then used to impact the locking mechanism 94 to drive the device 40 into the landing nipple. After setting the device, the wire line 104 and removable locking device 94 have been removed from the well. The well is “swabbed” to remove unwanted water. In this regard, it is envisioned that high pressure gas would be used to force water from the system through the device 40 into the well bottom. Alternatively, water can be removed from the system prior to the insertion of the well device 40 . Once the water is removed, the hydrocarbon well products move through the central throughbore 60 and are retrievable from the well. The device can similarly be removed from the well using the locking device 40 .
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. While the invention has been illustrated and described as embodied in device for improving oil and gas recovery in wells, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
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 device for improving recovery of hydrocarbons through a well is provided. The device creates, regulates and maintains a calculated bottomhole pressure at a desired level and creating above the device a two-phase gas-liquid homogenous flow for efficient lifting of hydrocarbons to a surface. The device has a body having a central through-going opening with a shape corresponding to a shape of a laval nozzle and with a cross section which changes steplessly and gradually, and a mandrel attachable to a tubing and associated with the body without interfering with a flow of fluids. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the invention relates to interconnect structures for input and output signals of an integrated circuit. More specifically, the present invention relates to the interconnect structure for programmable logic devices.
2. Background Technology
Integrated circuits (ICs), and specifically programmable ICs such as field programmable gate arrays (FPGAs), contain a number of input and output signal pads. When packaged, these pads are coupled through leads to external pins that are used to connect the IC to a larger system or "board" that contains other ICs. When packaged with pins, the IC is often called a "chip" or IC chip.
A system designer conventionally develops a particular board layout giving particular assignments for both the chips of the board and for the signal lines that run between the chips. Therefore, based on the particular socket or area on the board where a chip is to sit, a designer predetermines which input/output signals are to be assigned to which input/output pins of the chip. This pin assignment is often performed before the chip is designed or before the design is laid-out in the IC. Once assigned, a pin is said to be "locked" from use by other signals. As discussed below, IC pin "lock" can cause severe problems for a circuit designer in terms of circuit layout.
FIG. 1 illustrates a typical FPGA 50 including a number of configurable logic blocks (CLBs) 20 that are coupled to a programmable interconnect structure (not shown). As is well known, the interconnect structure allows input/output lines of CLBs 20 to be programmably coupled together. CLBs 20, also well known, can be programmed to perform a number of different logic functions.
FPGA 50 also contains a number of input/output blocks (IOBs) 32 that are used by the IC as an interface between external pins 12 and CLBs 20. IOBs 32 are similarly coupled to the programmable interconnect structure. Although CLBs 20 are coupled together using the programmable interconnect structure, each IOB 32 is directly coupled to an individual pad 10 and an individual external pin 12. For example, IOB 32a of FIG. 1 is directly coupled to pad 10a having an external pin 12a.
As discussed above, when FPGA 50 is to be programmed, its pin assignments can be predetermined, i.e. certain signals are assigned to individual pins. However, when the circuit design to be programmed on FPGA 50 is being designed, it may be more efficient to place certain logic within one or more CLBs that are not spatially near the pin and associated IOB that are to output the signal generated by the logic. For instance, it may be more efficient or a better use of resources to have CLB 20a generate a signal that distant pin 12c needs even though these elements are not near each other. Alternatively, it may be more efficient or easier to place certain logic within one or more CLBs that are not spatially near the pin and associated IOB that input the signal needed by the certain logic. However, by placing the logic far away from its associated pin, a routing problem exists in supplying the signals from the logic to the pin.
A chip layout problem occurs as a result of the predetermined pin assignments done by system designers. Specifically, circuit layout designers feel constrained or forced to fit a large amount of circuitry into the area of FPGA 50 that is near the assigned pins. This design method is problematic because not all of the logic associated with a particular input or output pin can easily be placed adjacent to the pin. In some cases, there are not enough routing resources within the constrained IC area. Therefore, signal routing becomes a problem as the circuitry is spread out. In some instances, circuit design and functionality become reduced to fit in the constrained area. In other instances, the crowded circuits fit near the pins, but there is little room for additional circuits or expansion, thereby causing signal delays and/or signal errors because of indirect or complex signal routing.
In either of the above cases, it is more advantageous to uniformly utilize the resources of FPGA 50 that are distributed throughout the FPGA's area. Therefore, a need arises for a mechanism that allows system designers to evenly spread logic throughout FPGA 50 device even though the pins of FPGA 50 device are preassigned ("locked"). The present invention allows such advantageous functionality.
SUMMARY OF THE INVENTION
A structure is disclosed for allowing input/output signal routing along the periphery of a programmable integrated circuit (IC) so that uniform circuit usage across the programmable integrated circuit is allowed irrespective of predetermined pin assignments. A structure in accordance with the present invention includes a plurality of periphery interconnect lines that run along the periphery of a programmable IC. Input/output blocks (IOBs) that are similarly disposed along the periphery of the programmable IC and configurable logic blocks (CLBs) are coupled to the plurality of periphery interconnect lines using a programmable local interconnect structure. Each IOB includes an associated pad and an input/output external pin. Individual segments of the plurality of periphery interconnect lines utilize a programmable bi-directional buffer to buffer a line of the periphery interconnect. The programmable buffer can also be programmed as an open circuit creating individual line segments. Uniform buffered segments of the periphery interconnect are disposed such that for an interconnect of n lines, each line of the periphery interconnect is buffered at least once every n segments. This configuration is maintained even though segments wrap around corners within the IC. In operation, a CLB located away from the periphery of the IC can output a signal over the local interconnect, onto the plurality of periphery interconnect lines, onto another local interconnect, into an IOB and over its external pin. To input a signal, the path is reversed. The pin and the CLB need not be adjacent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a field programmable gate array (FPGA) having a number of internal elements including: configurable logic blocks (CLBs), input/output blocks (IOBs), pads, and pins.
FIG. 2 illustrates a schematic of the present invention periphery interconnect structure in a ring configuration between IOBs within an FPGA.
FIG. 3 illustrates a leg of a ring configured periphery interconnect structure of the present invention with n buffered stages for n signal lines.
FIG. 4 is a logical schematic of a connection between an IOB and a segment of the periphery interconnect structure of the present invention.
FIG. 5 is a logical schematic of a connection between a CLB and a segment of the periphery interconnect structure of the present invention.
FIG. 6 is a schematic illustration of a programmable bi-directional buffer of the present invention periphery interconnect structure.
FIG. 7A is a schematic illustration of a portion of the periphery interconnect structure of FIG. 6 disposed in a first corner correlating to the lower left corner of FIG. 2.
FIG. 7B is a schematic illustration of a portion of the periphery interconnect structure of FIG. 6 disposed in a second corner correlating to the upper left corner of FIG. 2.
FIG. 7C is a schematic illustration of a portion of the periphery interconnect structure of FIG. 6 disposed in a third corner correlating to the upper right corner of FIG. 2.
FIG. 7D is a schematic illustration of a portion of the periphery interconnect structure of FIG. 6 disposed in a fourth corner correlating to the lower right corner of FIG. 2.
FIG. 8 is a logical diagram of a CLB to IOB connection over the local and periphery interconnect structure.
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes a periphery interconnect structure that in one embodiment is composed of interconnected segments that are disposed in a ring or annular shaped geometry within the periphery of a programmable integrated circuit, such as an FPGA. The periphery interconnect structure in one embodiment contains eight signal lines; however, note that the present invention is well suited to use more or less lines in the periphery interconnect structure. The periphery interconnect structure is segmented and each segment adopts a uniform structure to facilitate duplication across the FPGA. The periphery interconnect structure allows distant configurable logic blocks (CLBs) and input/output blocks (IOBs) to programmably interconnect so that CLBs within a variety of different locations in the FPGA can communicate with a number of different IOBs.
The present invention reduces the problems associated with pin-lock by providing a decoupling structure where a CLB associated with a particular IOB does not need to be located adjacent to the IOB within the FPGA. In accordance with the present invention, circuit layout designers are not constrained to placing certain logic in any particular location on the FPGA (e.g., adjacent to the associated IOB) because the associated IOB can be readily reached using the periphery interconnect structure.
FIG. 2 illustrates an FPGA 100 which includes an array of CLBs 110. Note that the number of CLBs shown in FIG. 2 is exemplary and the present invention is well suited to accommodate any number CLBs. For example, in one embodiment of the present invention, an array of 36×36 CLBs is used. A programmable local interconnect structure (not shown in FIG. 2) is coupled between CLBs 110 to provide communication between CLBs 110. The programmable local interconnect structure is well known in the art and, therefore, not explained in detail herein. Within the programmable local interconnect structure are drivers (i.e. buffers) 112.
In accordance with the present invention, FPGA 100 further includes a peripheral interconnect structure 145. In one embodiment, structure 145 is ring-shaped and includes corner interconnect segments ("corner segments") 145c, 145f, 145i, 145l and edge interconnect segments ("edge segments") 145a, 145b, 145d, 145e, 145g, 145h, 145j, and 145k. Although not shown in FIG. 2, IOBs are located along the periphery of FPGA 100 adjacent to periphery interconnect structure 145. In one embodiment, two IOBs are located adjacent to each edge segment of periphery interconnect structure 145. The ring geometry of the present invention is particularly useful because the IOBs and the external pins of the IC chip tend to be located in this shape.
Each edge segment is of a uniform construction so that it can readily be duplicated and used throughout the FPGA 100. Each edge segment includes a programmable bi-directional buffer element ("buffer") 114 located in a uniform position within each segment. The programmable buffer element 114, as will be described in more detail below, can be programmed as an open circuit. Although buffer 114 can be located in a variety of different positions within the edge segment, an exemplary placement is shown in FIG. 2. In this example, edge segments that are placed along the left and right edges of FPGA 100 (e.g. edge segments 145d, 145e, 145j, and 145k), locate buffer 114 in the lower left side. This is true whether or not the interconnect segment is located on the right or left edge.
In this example, the interconnect segments that are placed along the top and bottom edges of FPGA 100, e.g. edge segments 145a, 145b, 145g, and 145h, include buffer 114 in the upper left side. Again, this is true whether or not the interconnect segment is located on the top or bottom edge. In this fashion, FIG. 2 illustrates that the edge segments of the peripheral interconnect structure 145 are uniformly disposed and oriented within FPGA 100 irrespective if the segment is positioned on the top or bottom edge or along the left or right edge. This uniformity facilitates duplication during fabrication.
As will be described in more detail below, the group of signal lines that extends through the segments have a particular pattern where the signal line on one end of the group traverses the other seven lines in a first direction to relocate at the other end of the group. Each of the other lines traverses in a second direction, opposite the first direction, by one line. By adopting this particular pattern and uniformly placing buffer 114 at the same location within each edge segment, the segments, when coupled together, insure that each line of the group of lines will be buffered at least once every eight consecutive segments. This particular pattern is advantageous because each line in a segment having n lines in a group will be buffered at least once for every n consecutive edge segments through which the line passes.
Because lines of periphery ring structure 145 are used for carrying signals between two points within FPGA 100, a signal may be provided to structure 145 at one location and exit at any location. In other words, it is not required that the signals traverse a full "lap" of structure 145. In fact, in one embodiment, buffers 114 are programmed to be open circuits, thereby allowing line segmentation within periphery ring structure 145. This line segmentation allows multiple point to point coupling along interconnect structure 145.
FIG. 3 illustrates a portion or leg of the peripheral interconnect structure containing eight edge segments 145(1)-145(8). Only the segments 145(1), 145(2), and 145(8) are shown for clarity. In this example, programmable bi-directional buffer 114 is located along the bottom right of each segment (on line 2 in segment 145(1), on line 3 in segment 145(2), and on line 1 in segment 145(8)). Eight lines enter edge segment 145(1), wherein lines 2-8 traverse down one line each and line 1 traverses seven lines up. This traversing in the structure is called a "shifting configuration." Eight lines enter segment 145(2) and lines 3-8 and 1 each traverse down one line and line 2 traverses seven lines up. This pattern continues through edge blocks 145(3)-145(7). Finally, eight lines enter edge segment 145(8) and lines 1-7 each traverse down by one line and line 8 traverses up by 7 lines. In this arrangement, each of the signal lines of the group are physically shifted down by one position with the outside signal line physically wrapping around to the opposite side of the segment. By fully traversing segments 145(1)-145(8), each line of lines 1-8 is buffered by a buffer 114 at least once. This advantageous result is reached using a uniform segment having a uniform shifting configuration and a uniformly placed buffer 114. Note that within the present invention buffer 114 can be placed along any line of the group within a particular segment as long as the segment is uniformly duplicated (e.g., buffer 114 holds a uniform position).
FIG. 4 illustrates the connection of an IOB 115, which includes a number of input and output lines of which exemplary lines 251 and 253 are shown, to an exemplary edge segment of periphery interconnect structure 145 of the present invention. This connection is facilitated by a local interconnect structure 60. Although local interconnect structure 60 can contain different numbers of lines, an exemplary interconnect is shown in FIG. 4 having eight lines 60a-60h. In accordance with one embodiment, lines 251 and 253 of IOB 115 are programmably coupled to lines 60a and 60d of local interconnect structure 60 via programmable interconnect points (PIPs) 251a and 253a. Each of these PIPs, as is well known in the art, includes a pass transistor coupling the two lines of the intersection and also includes a programmable memory cell that controls the gate of the pass transistor. In this manner, a PIP allows a programmable interconnection between the intersecting lines. The memory cell can be of a number of different memory types, including SRAM, DRAM, ROM, FLASH, etc., or can be fabricated from antifuse material.
As shown in FIG. 4, IOB 115 can utilize at least two of the local interconnection lines, 60a and 60d. Although a variety of interconnections are considered within the scope of the present invention, an exemplary interconnection structure is shown in FIG. 4 wherein each line 60a-60h of local interconnect structure 60 is progressively coupled to at least one line of the periphery interconnect structure lines 145a-145h. In this embodiment, a single PIP is placed at the intersection of the following lines: 60a and 145h; 60b and 145g; 60c and 145f; 60d and 145e; 60e and 145d; 60f and 145c; 60g and 145b; and 60h and 145a. Using the above-described programmable connections, IOB 115 can be coupled to at two lines of the periphery interconnect structure 145 of the present invention (i.e. lines 145(h) and 145(e)) using the local interconnect structure 60.
Although only two periphery interconnect lines (e.g., 145h and 145e) are programmably coupled to IOB 115, because the lines of periphery interconnect structure 145 shift one position for each CLB position, different connections are available to adjacent IOBs. Specifically, in accordance with the present invention, IOBs 115 can be programmably coupled to any line of local interconnect structure 60 or any line of periphery interconnect structure 145. Note that IOB 115 is coupled to a pad 10.
FIG. 5 similarly illustrates a CLB 110 programmably coupled to a segment of periphery interconnect structure 145 of the present invention using local interconnect structure 60. Similar to the connection structure of IOB 115 in FIG. 4, CLB 110 contains a number of input and output signals of which only exemplary signal lines 261 and 263 are shown. These signal lines are programmably coupled to two lines of local interconnect structure 60 using PIPs 261a and 263a. Because local interconnect structure 60 is disposed throughout FPGA 100, a large number of CLBs 110 are IOBs 115 within FPGA 100 have direct access to local interconnect structure 60 and, therefore, have direct access to multiple points of periphery interconnect structure 145 of the present invention.
FIG. 6 illustrates an exemplary programmable bi-directional buffer 114 ("buffer 114") of the present invention. In the embodiment, a line of periphery interconnect structure 145 is coupled to node 221 and to node 223 as the input and output ports of buffer 114. To buffer a signal from node 221 to node 223, memory cell 201 is programmed with a "1" and memory cell 203 is programmed with a "0." In this manner, n-type pass transistors 205 and 215 are ON, whereas n-type pass transistors 207 and 213 are OFF. In this configuration, a signal originates from node 221, passes through transistor 205, through inverters 209 and 211, through transistor 215, and exits at node 223. To buffer a signal from node 223 to node 221, memory cells 201 and 203 are programmed with a "0" and a "1", respectively, thereby turning ON pass transistors 207 and 213 and turning OFF pass transistors 205 and 215. In this configuration, a signal originates from node 223, passes through transistor 207, through inverters 209 and 211, through transistor 213, and exits at node 221. To program bi-directional buffer 114 to function as an open circuit, both memory cells 201 and 203 are programmed with a "0." Bi-directional buffers are described in detail in U.S. Pat. Nos. 4,695,740 (issued on Sep. 22, 1987 to Carter), 4,713,557 (issued on Dec. 15, 1987 to Carter), and 4,835,418 (issued on May 30, 1989 to Hsieh), and are incorporated by reference herein.
FIGS. 7A, 7B, 7C and 7D illustrate corner segments 145c, 145f, 145h, and 1451, respectively, of the present invention. These corner segments solve two constraints. First, as described in reference to FIG. 3, in every n consecutive segments, each line of a group of n lines is buffered at least once. In accordance with the present invention, this requirement is maintained even in the corner segments. In order to satisfy this requirement, the present invention insures that upon rounding a corner, the least recently buffered signal line of a group is buffered by the next segment, and the most recently buffered signal line is shifted to a position of the group that will be buffered last. Second, because the uniformly constructed segments of the structure 145 are positioned in a uniform orientation with respect to the top and bottom edges and with respect to the left and right sides of the FPGA 100, the corner structures are not identical.
Although the signal lines of the segments of periphery interconnect structure 145 are bi-directional, for purposes of discussing FIGS. 7A, 7B, 7C, and 7D, a particular direction is adopted.
FIG. 7A illustrates the bottom left corner segment 145c which couples edge segment 145d having a buffer 114 oriented at the outer edge of the segment and edge segment 145b having a buffer 114 oriented at the inner edge of the segment. With respect to edge segment 145b, in the bottom position at the left edge, line 1 is the least recently buffered line progressing right to left because buffer 114 is located at the top of segment 145b. As shown, line 1 enters at the bottom of segment 145b, is shifted up to the top, and exits segment 145b at the top. Corner segment 145c shifts line 1 to the left most position since buffer 114 is located in the left for the segments along the left edge of FPGA 100.
Lines 2-8 are individually shifted down (as they pass from right to left) by one line in edge segment 145b with line 8 being the most recently buffered and line 2 being the second least recently buffered line at the left edge of edge segment 145b. Corner segment 145c shifts these lines such that line 2 is placed at the right most position and line 8 is the second from the left most position entering segment 145 d from the bottom. In this configuration, line 2 will be next to be buffered after segment 145d and line 8 will be buffered last.
FIG. 7B illustrates the top left corner segment 145f which couples edge segment 145e having a buffer 114 oriented at the outer edge of the segment and edge segment 145g having a buffer 114 also oriented at the outer edge of the segment. With respect to edge segment 145e, in the right position, line 8 is the least recently buffered line progressing from bottom to top because buffer 114 is located at the left of segment 145e. As shown, line 8 enters at the right of segment 145e, is shifted to the left and exits segment 145b at the left. In the orientation of segment 145g, the lines are shifted before they reach buffer 114. Therefore, line 8 is shifted by corner segment 145f such that it enters segment 145g in the second from the top position, and is then shifted to the top position and buffered by 114.
Line 1 of FIG. 7B is the most recently buffered signal line with respect to the top of segment 145e because it is in the left most position entering segment 145e from the bottom and is shifted one line to the right upon exiting segment 145e from the top. Since line 1 was the most recently buffered, corner segment 145f routes line 1 to the top of segment 145g because segment 145g will shift this line to the bottom, being the last line in the group to be buffered again.
Lines 2-7 of FIG. 7B, as entering the bottom of segment 145e, are individually shifted to the right by one line in segment 145e with line 2 being the second most recently buffered and line 7 being the second least recently buffered line. Corner segment 145f shifts these lines such that line 2 is placed at the bottom position entering segment 145g and line 7 is the third from the top most position entering segment 145g. In this configuration, line 7 will be next to be buffered after segment 145g and line 2 will be the last buffered.
FIG. 7C illustrates the top right corner segment 145i which couples edge segment 145h having a buffer 114 oriented at the outer edge of the segment and edge segment 145j having a buffer 114 oriented at the inner edge of the segment. With respect to segment 145h, exiting edge segment 145h from the right, line 7 is in the top position and is the most recently buffered line since the buffer 114 is located at the top of segment 145h. Line 6 is in the second to the top position and is the least recently buffered line. As shown, corner segment 145i shifts lines 7-1 so that they enter segment 145j in the left most position to the second to the right most position, respectively. Line 8 is shifted to the right most position by corner segment 145i.
Corner segment 145i shifts line 6 such that it enters segment 145j at the second from the left most position, is shifted to the left most position and buffered by buffer 114. Line 5 will be the next line of the group to be buffered. Line 7 enters segment 145j at the left most position, is shifted to the right most position and will be the last line of the group to be buffered, progressing from top to bottom.
FIG. 7D illustrates the bottom right corner segment 145i which couples edge segment 145k having a buffer 114 oriented at the inner edge of the segment and edge segment 145a having a buffer 114 also oriented at the inner edge. Lines 1-8 enter segment 145k from the top, line 2 exits the segment as the most recently buffered line, line 3 is the least recently buffered line, and line 4 is the next least recently buffered. Corner segment 145l switches the lines so that line 3 enters segment 145a from the right at the top most position, and line 2 is at the second from the top most position. Line 1 is the third from the top most position and lines 4-8 are arranged in order such that line 4 is the bottom position and line 8 is in the fourth from the top most position. Line 3 is then buffered by segment 145a and line 4 is shifted to the top by segment 145a and is buffered next. Line 2 will be the last line of the group to be buffered.
Note that the configuration of corner segments 145c, 145f, 145i, and 145l depends on (1) the orientation of buffers 114 with respect to the two edge segments located adjacent to the corner segment and (2) whether the signal lines pass through a shifting configuration, two shifting configurations, or no shifting configurations between buffers 114. For instance, with respect to FIG. 7B, the buffer configurations for edge segments 145e and 145g are outer and outer, respectively, and there are two shifting configurations between buffers 114. Table I below illustrates these two elements for each corner segment of the present invention.
TABLE I______________________________________ Edge Shifting ConfigurationsCorner Buffer Orientation Between Buffers______________________________________Bottom-Left Outer and Inner OneUpper-Left Outer and Outer TwoUpper-Right Outer and Inner OneBottom-Right Inner and Inner None______________________________________
As discussed above, the corner segments provide a configuration of the signal lines such that the least recently buffered signal line is oriented such that it will be the next buffered signal line after the corner is turned. This is true irrespective of the segment configurations as shown in Table I. Also, order is maintained by the present invention such that the most recently buffered signal line is situated such that it will be the last signal line of the group to be buffered. The present invention utilizes a uniform edge segment structure and orientation to provide the above advantageous result.
Using the present invention, designers can place specific logic at any place within FPGA 100 even though that logic must interface with a preassigned pin 12. FIG. 8 illustrates a logical diagram of a typical implementation. The interfacing CLB 110 couples with periphery interconnect structure 145 using a programmable local interconnect 60. A particular line (e.g., assume the line is called "x") of the periphery interconnect structure 145 is coupled to a particular line of local interconnect structure 60. Line x is then routed through the segments of peripheral interconnect structure 145 and at every 8 segments (in one embodiment) the signal is buffered. This is true even though the signal passes through the upper and lower left corners of FPGA 100. Buffer elements 114 along the signal line x are programmed to buffer the signal in the appropriate direction (e.g., depending on if the signal is a input signal to CLB 110 or an output signal from CLB). Line x is programmably coupled to a line of local interconnect 60' which is programmably coupled to interface with IOB 115. IOB 115 is then coupled to pad 10 which couples to preassigned external pin 12. The configuration of FIG. 8 is well suited for input signals onto pin 12 and into CLB 110 or for output signal from CLB 110 to pin 12.
Because periphery interconnect structure 145 is routed along the periphery of FPGA 100, structure 145 advantageously and dramatically reduces interference with other programmable interconnect structures of FPGA 100.
The preferred embodiment of the present invention, a periphery segmented ring interconnect structure for coupling between CLBs and IOBs having a uniform buffered segment such that n buffered stages buffer n interconnect lines, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims. | A mechanism is provided for allowing input/output signal routing along the periphery of a programmable integrated circuit (IC) so that uniform circuit usage across the programmable integrated circuit is allowed in conjunction with predetermined pin assignments. The mechanism includes a plurality of periphery interconnect lines that run along the periphery of a programmable IC. Input/output blocks (IOBs) that are similarly along the periphery of the programmable IC and configurable logic blocks (CLBs) are coupled to the plurality of periphery interconnect lines using a programmable local interconnect structure. Each IOB includes an associated pad and an input/output external pin. Individual segments of the plurality of periphery interconnect lines utilize a bi-directional buffer to buffer a line of the periphery interconnect. Uniform buffered segments of the periphery interconnect are disposed such that for an interconnect of n lines, each line of the periphery interconnect is buffered at least once every n segments. In operation, a CLB located away from the periphery of the IC can output a signal over the local interconnect, onto the plurality of periphery interconnect lines, onto another local interconnect, into an IOB and over its external pin. To input a signal, the path is reversed. The pin and the CLB do not need to be adjacent. | 7 |
TECHNICAL FIELD
The present invention relates to a fixed type constant velocity universal joint, and more specifically, to a fixed type constant velocity universal joint which is used in a power transmission system for automobiles and various industrial machines and which allows only angular displacement between two shafts on a driving side and a driven side.
BACKGROUND ART
For example, a fixed type constant velocity universal joint can be taken as an example of a constant velocity universal joint used as means for transmitting a rotational force from an engine to wheels of an automobile at a constant velocity. The fixed type constant velocity universal joint has a structure in which two shafts on a driving side and a driven side are coupled to each other and rotational torque can be transmitted at a constant velocity even when the two shafts form an operating angle. Generally, a Birfield type (BJ) constant velocity universal joint and an undercut-free type (UJ) constant velocity universal joint have been widely known as the above-mentioned fixed type constant velocity universal joint.
Further, as illustrated in FIG. 6 , the fixed type constant velocity universal joint of the Birfield type (BJ) includes: an outer race 3 having an inner surface 1 in which a plurality of track grooves 2 are equiangularly formed along an axial direction and serving as an outer joint member; an inner race 6 having an outer surface 4 in which a plurality of track grooves 5 are equiangularly formed in pairs with the track grooves 2 of the outer race 3 along the axial direction and serving as an inner joint member; a plurality of balls 7 interposed between the track grooves 2 of the outer race 3 and the track grooves 5 of the inner race 6 , for transmitting torque; and a cage 8 interposed between the inner surface 1 of the outer race 3 and the outer surface 4 of the inner race 6 , for retaining the balls 7 . In the cage 8 , a plurality of window portions 9 for housing the balls 7 are arranged along a circumferential direction.
On opening edges (side edges) of each of the track grooves 2 of the outer race 3 and opening edges (side edges) of each of the track grooves 5 of the inner race 6 , in order to avoid stress concentration on both the side edges thereof, chamfers 10 , 10 , 11 , and 11 are provided as illustrated in FIGS. 7 and 8 .
In some conventional cases, the chamfers are finished so as to have a round shape (Patent Literatures 1 to 3). By finishing of each of the chamfers into a round shape as just described, stress concentration upon application of high torque (upon input of excessive torque from a vehicle) is easily reduced. Further, the round-shaped chamfers are designed to prevent the edges from being chipped when the balls are pressed against the track grooves and climb onto track edges (track-groove side edges) upon the application of high torque. As a result, shortening of a service life is prevented.
Incidentally, as illustrated in FIG. 7 , on an opening side of the outer race 3 , there is provided an inlet tapered portion 12 functioning as an angle-limitation stopper so that a shaft does not form more than a certain angle when forming an angle. Normally, a track-groove corresponding edge portion 12 a on the inlet tapered portion 12 (edge portion on an axial end portion of each of the track grooves) is formed as a sharp edge. However, in order to reduce stress concentration at a high angle, the track-groove corresponding edge portion 12 a is chamfered by a machining process in some cases. Further, as illustrated in FIG. 8 , an axial edge 13 of each of the track grooves 5 of the inner race 6 is formed in a shape of a sharp edge portion.
CITATION LIST
Patent Literature 1: Japanese Utility Model Application Laid-open No. Hei 06-24237
Patent Literature 2: Japanese Utility Model Examined Publication No. Hei 07-25458
Patent Literature 3: Japanese Patent Application Laid-open No. 2008-2625
SUMMARY OF INVENTION
Technical Problem
When the constant velocity universal joint is exposed to high torque (input of excessive torque from a vehicle), there occurs a phenomenon that the balls 7 climb onto the track-side edge portions of the track grooves 2 and 5 , with the result that the balls 7 reach the chamfers 10 and 11 on both the side edges of the tracks. Under the circumstance, conventionally, each of the chamfers 10 and 11 have been formed in a round shape so as to reduce stress concentration, and thus the edge portions of the chamfers 10 and 11 have been prevented from being chipped.
Meanwhile, at the time of an unexpected high-angle operation, in particular, when an angle expected during use of a constant velocity universal joint is exceeded for some reason, the ball 7 moves to the track-groove corresponding edge portion 12 a on the inlet tapered portion 12 of the track grooves 2 of the outer race 3 or to the axial edge (edge portion) 13 of each of the track grooves 5 of the inner race 6 . As a result, the ball 7 comes into contact with the track-groove corresponding edge portion 12 a and the axial edge 13 . When high torque is applied in this state, the ball 7 bites into the track-groove corresponding edge portion 12 a and the like, with the result that the track-groove corresponding edge portion 12 a and the like are chipped. Once an excessively high angle is formed and the track-groove corresponding edge portion 12 a and the like are chipped, damage develops from the chipped portions, with the result that a durability life of the joint as a whole is shortened.
In view of the above-mentioned problems, the present invention has been made to provide a fixed type constant velocity universal joint which is capable of achieving the following even at the time of an unexpected high-angle operation, in particular, even when an angle expected during use of a constant velocity universal joint is exceeded: reduction of stress generated when the balls and the edge portions (edge portions on the axial end portions of the track grooves) interfere with each other, suppression of chipping of the edge portions, and prolongation of a service life of the joint as a whole.
Solution to Problem
A first fixed type constant velocity universal joint according to the present invention includes: an outer joint member having an inner surface in which a plurality of track grooves are formed; an inner joint member having an outer surface in which a plurality of track grooves are formed; a plurality of balls interposed between the plurality of track grooves of the outer joint member and the plurality of track grooves of the inner joint member, for transmitting torque; and a retainer for retaining the plurality of balls, in which a cutout round portion is provided at least at a ball-contact-point corresponding part on a track inlet end of each of the plurality of track grooves of the outer joint member.
A second fixed type constant velocity universal joint according to the present invention includes: an outer joint member having an inner surface in which a plurality of track grooves are formed; an inner joint member having an outer surface in which a plurality of track grooves are formed; a plurality of balls interposed between the plurality of track grooves of the outer joint member and the plurality of track grooves of the inner joint member, for transmitting torque; and a retainer for retaining the plurality of balls, in which a cutout round portion is provided at least at a ball-contact-point corresponding part on a track inlet end of each of the plurality of track grooves of the inner joint member.
A third fixed type constant velocity universal joint according to the present invention includes: an outer joint member having an inner surface in which a plurality of track grooves are formed; an inner joint member having an outer surface in which a plurality of track grooves are formed; a plurality of balls interposed between the plurality of track grooves of the outer joint member and the plurality of track grooves of the inner joint member, for transmitting torque; and a retainer for retaining the plurality of balls, in which: a cutout round portion is provided at least at a ball-contact corresponding part on a track inlet end of each of the plurality of track grooves of the outer joint member; and a cutout round portion is provided at least at a ball-contact-point corresponding part on a track inlet end of each of the plurality of track grooves of the inner joint member.
According to the present invention, even at the time of an unexpected high-angle operation, in particular, even when an angle expected during use is exceeded for some reasons and the balls are positioned at axial end portions of the track grooves of the outer joint member and/or the inner joint member, it is possible that the cutout round portion prevents each of the balls from biting into the axial end portions.
The cutout round portion may be finished by cold forging formation, and an entire of each of the plurality of track grooves may be finished by cold forging formation. Further, a tapered portion expanding from an interior side to an inlet side may be provided at an inlet end portion of the outer joint member, the tapered portion being finished by the cold forging formation, and the cutout round portion may be finished by a cutting process. Still further, machining allowance may be provided with respect to a grinding process of the plurality of track grooves, and the cutout round portion may be secured as a cold-forging finished portion even after the grinding process of the plurality of track grooves.
It is preferred that a PCD clearance representing a difference between a pitch circle diameter of each of the plurality of track grooves of the outer joint member and a pitch circle diameter of each of the plurality of track grooves of the inner joint member be set to range from −0.02 mm to +0.3 mm. With this setting, backlash between components including the outer joint member, the inner joint member, the balls, and the retainer (cage) can be suppressed to the minimum. Note that, when the PCD clearance is less than −0.02 mm, it is difficult to secure operability of the constant velocity universal joint. In contrast, when the PCD clearance is more than +0.3 mm, the backlash between the components becomes larger.
Advantageous Effects of Invention
According to the constant velocity universal joint of the present invention, even when the balls are positioned at the axial end portions of the track grooves of the outer joint member and/or the inner joint member at the time of an unexpected high-angle operation and the like, it is possible that the cutout round portion prevents each of the balls from biting into the axial end portions. That is, even in such a case, it is possible to reduce stress generated when the ball and the edge portions (edge portions on the axial end portions) of the track grooves interfere with each other, to thereby reduce a chipping risk of the edge portions. As a result, a service life of the constant velocity universal joint as a whole can be prolonged.
The cutout round portion can be finished by cold forging formation, a cutting process, or the like, and hence formation thereof does not involve complication. In particular, when the track grooves, the cutout round portion, and the inlet tapered portion are finished simultaneously by cold forging, post-processes (turning or ground-finishing after thermal treatment) can be omitted. Therefore, it is possible to achieve reduction of a formation time period and cost reduction.
Further, when the track grooves are finished by a grinding process, it is preferred that machining allowance be provided with respect to the grinding process of the track grooves and the cutout round portion be secured as a cold-forging finished portion even after the grinding process of the track grooves. With this method, the cutout round portion can be reliably formed.
By setting of the PCD clearance to range from −0.02 to +0.3 mm, the backlash between the components can be suppressed to the minimum, and generation of rattling noise can be suppressed at the time of attachment of the constant velocity universal joint to a vehicle.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 A sectional view of a fixed type constant velocity universal joint according to an embodiment of the present invention.
FIG. 2A A perspective view of a main portion, illustrating cutout round portions formed in an outer race of the fixed type constant velocity universal joint, the cutout round portions being provided at a ball-contact-point corresponding part.
FIG. 2B A perspective view of a main portion, illustrating the cutout round portion formed in the outer race of the fixed type constant velocity universal joint, the cutout round portion being provided over the entire of an axial end portion.
FIG. 3A A perspective view of a main portion, illustrating cutout round portions formed in an inner race of the fixed type constant velocity universal joint, the cutout round portions being provided at the ball-contact-point corresponding part.
FIG. 3B A perspective view of a main portion, illustrating the cutout round portion formed in the inner race of the fixed type constant velocity universal joint, the cutout round portion being provided over the entire of an axial end portion.
FIG. 4 A sectional view illustrating shapes of track grooves of the fixed type constant velocity universal joint.
FIG. 5A An enlarged sectional view of a main portion of a finished product, illustrating a forming method for the outer race of the fixed type constant velocity universal joint.
FIG. 5B An enlarged sectional view of a main portion in a state in which machining allowance is provided, illustrating the forming method for the outer race of the fixed type constant velocity universal joint.
FIG. 6 A sectional view of a conventional fixed type constant velocity universal joint.
FIG. 7 A schematic perspective view of an outer race of the conventional fixed type constant velocity universal joint.
FIG. 8 A schematic perspective view of an inner race of the conventional fixed type constant velocity universal joint.
DETAILED DESCRIPTION OF THE INVENTION
In the following, description is made of the embodiment of the present invention with reference to FIGS. 1 to 5 .
A fixed type constant velocity universal joint according to the present invention includes, as illustrated in FIG. 1 , an outer race 23 having an inner surface 21 in which a plurality of track grooves 22 are formed along an axial direction and serving as an outer joint member, and an inner race 26 having an outer surface 24 in which a plurality of track grooves 25 are formed along the axial direction and serving as an inner joint member. The track grooves 22 of the outer race 23 and the track grooves 25 of the inner race 26 are provided in pairs, and balls 27 for transmitting torque are interposed between the track grooves 22 of the outer race 23 and the track grooves 25 of the inner race 26 . A cage (retainer) 28 is interposed between the inner surface 21 of the outer race 23 and the outer surface 24 of the inner race 26 , and the balls 27 are retained in a plurality of window portions (pockets) 29 arranged at a predetermined pitch along a circumferential direction of the retainer 28 .
The track grooves 22 of the outer race 23 and the track grooves 25 of the inner race 26 have a Gothic-arch shape obtained by only a forging process, or by a cutting process after the forging process, or the like. As illustrated in FIG. 4 , by adoption of the Gothic-arch shape, the track grooves 22 and 25 and the ball 27 are held in angular contact with each other. That is, the ball 27 is held in contact with the track groove 22 of the outer race 23 at two points C 11 and C 12 , and in contact with the track groove 25 of the inner race 26 at two points C 21 and C 22 . Angles formed between a center O 1 of the ball 27 and each of the contact points C 11 , C 12 , C 21 , and C 22 of the track grooves 22 and 25 are contact angles α.
Each of the track grooves 22 of the outer race 23 has chamfers (chamfered portions) 30 and 30 provided on both side edges (groove opening edges) thereof, and each of the track grooves 25 of the inner race 26 has chamfers (chamfered portions) 31 and 31 provided on both side edges (groove opening edges) thereof. Further, an inlet tapered portion 35 expanding from an interior side to an inlet side is provided at an opening end of the outer race 23 . The inlet tapered portion 35 functions as an angle-limitation stopper.
As illustrated in FIG. 2A , cutout round portions 32 and 32 are provided at a ball-contact-point corresponding part on a track inlet end 22 a of each of the track grooves 22 of the outer race 23 . Further, as illustrated in FIG. 3A , cutout round portions 33 and 33 are provided at the ball-contact-point corresponding part on a track inlet end 25 a of each of the track grooves 25 of the inner race 26 .
As illustrated in FIG. 2B , the cutout round portion 32 of the outer race 23 may be provided over the entire of the track inlet end 22 a . Further, as illustrated in FIG. 3B , the cutout round portion 33 of the inner race 26 may be provided over the entire of the track inlet end 25 a as well.
Incidentally, the cutout round portion 32 of the outer race 23 and the cutout round portion 33 of the inner race 26 can be formed by forging simultaneously with other portions at the time of forging. Further, when the track grooves 22 and 25 are formed by only a forging process, or by a cutting process after the forging process, or the like, the cutout round portions 32 and 33 may be formed by processes such as cutting and grinding after the forging.
When the track grooves 22 and 25 are finished by a grinding process after finishing of the cutout round portions 32 and 33 by cold forging, it is preferred to set machining allowance in track-groove grinding portions so that the cutout round portions finished by cold forging after grinding are reliably secured.
For example, in a case of the outer race 23 as illustrated in FIG. 5A , when machining allowance 36 is set on the track groove 22 and the machining allowance 36 is removed by a grinding process of the track groove 22 as illustrated in FIG. 5B , the cutout round portion 32 finished by cold forging is not influenced by the grinding process of the track groove 22 . As a result, the cutout round portion 32 is capable of maintaining a shape after being finished by the cold forging. Note that, although not shown, on the inner race 26 as well, the machining allowance 36 may be secured in a grinding process of the track groove 25 .
Incidentally, in the constant velocity universal joint, a PCD clearance is set to range from −0.02 mm to +0.3 mm. The PCD clearance represents a difference between a pitch circle diameter of each of the track grooves 22 of the outer race 23 and a pitch circle diameter of each of the track grooves 25 of the inner race 26 , that is, a difference between a pitch circle diameter of the balls 27 (outer race PCD) in a state in which the balls 27 are held in contact with the track grooves 22 of the outer race 23 and a pitch circle diameter of the balls 27 (inner race PCD) in a state in which the balls 27 are held in contact with the track grooves 25 of the inner race 26 . Setting of the PCD clearance to zero or a negative value means closing of the PCD clearance.
Although the cutout round portions 32 and 33 are provided to the outer race 23 and the inner race 26 as described above in this embodiment, as another embodiment, it is possible to use a constant velocity universal joint in which the cutout round portion 32 is provided only to the outer race 23 , or possible to use a constant velocity universal joint in which the cutout round portion 33 is provided only to the inner race 26 .
Further, although the case where each of the balls 27 and the track grooves 22 and 25 are held in angular contact with each other is described above in this embodiment, in some constant velocity universal joints, each of the balls 27 and the track grooves 22 and 25 are held in circular contact with each other. In the case where such circular contact is made, each of the balls is held in contact at one point with each of the inner race track and the outer race track, and the one contact point moves over the entire of cross-section of each of the track grooves. Thus, as illustrated, for example, in FIGS. 2B and 3B , the movement at the one contact point can be coped with by the cutout round portions 32 and 33 formed over the entire of the track inlet ends 22 a and 25 a.
In the present invention, at the time of a high-angle operation, when the balls 27 are positioned at axial end portions of the track grooves 22 and 25 of the outer race 23 and/or the inner race 26 , the balls 27 are prevented from biting into the axial end portions. That is, it is possible to reduce stress generated when the balls 27 and edge portions (edge portions on the axial end portions) of the track grooves 22 and 25 interfere with each other, to thereby reduce a chipping risk of the edge portions. As a result, a service life of the constant velocity universal joint as a whole can be prolonged.
The cutout round portions 32 and 33 can be finished by cold forging formation, a cutting process, or the like, and hence formation thereof does not involve complication. In particular, when the track grooves 22 and 25 , the cutout round portions 32 and 33 , and the inlet tapered portion 35 are finished simultaneously by cold forging, post-processes (turning or ground-finishing after thermal treatment) can be omitted. Therefore, it is possible to achieve reduction of a formation time period and cost reduction.
When the track grooves 22 and 25 are finished by a grinding process after finishing of the cutout round portions 32 and 33 by cold forging, it is preferred to set machining allowance in the track-groove grinding portions. When the machining allowance is removed by a grinding process of the track grooves 22 and 25 , the cutout round portions 32 and 33 finished by the cold forging are not influenced by the grinding process of the track grooves 22 and 25 . As a result, each of the cutout round portions 32 and 33 is capable of maintaining a shape after being finished by the cold forging, and hence the cutout round portions can be formed at low cost.
By setting of the PCD clearance to range from −0.02 to +0.3 mm, backlash between components can be suppressed to the minimum, and generation of rattling noise can be suppressed at the time of attachment of the constant velocity universal joint to a vehicle. That is, by setting the PCD clearance to be small as just described, a phase region free from a load on the ball 27 can be reduced or eliminated. As a result, behavior of the ball 27 can be stabilized until the ball 27 is re-accommodated into the track groove 22 of the outer race 23 after once dropping off the track groove 22 . In addition, the behavior of the ball 27 can be stabilized also by reduction or elimination of the phase region free from the load on the ball 27 . As a result, it is possible to suppress generation of vibration or abnormal noise.
Hereinabove, although description has been made of the embodiment according to the present invention, the present invention is not limited to the above-mentioned embodiment, and various modification can be made thereto. For example, a size, a curvature radius, and the like of each of the cutout round portions 32 and 33 to be formed can be variously changed as long as problems do not occur, for example, in the following cases: the balls are less liable to bite into the axial end portions, the balls roll, and operating angles are formed. Further, a center curvature of each of the track grooves 22 of the outer race 23 and a center curvature of each of the track grooves 25 of the inner race 26 may be offset in a radial direction (radial offset) relative to a joint axis. Still further, arrangement pitches of the track grooves 22 and 25 in a peripheral direction may be equal pitches or unequal pitches, and the number of the balls, in other words, the number of the track grooves 22 and 25 may be arbitrarily increased and reduced.
INDUSTRIAL APPLICABILITY
As the constant velocity universal joint, one of an undercut-free type may be used, in which track groove bottoms are each provided with a circular-arc portion and a straight portion, or another constant velocity universal joint may be used, which has a shape in which portions corresponding to linear portions of the undercut-free type exhibit tapered shapes. Alternatively, still another constant velocity universal joint may be used, in which track groove bottoms are provided with a plurality of circular-arc portions having curvature radii different from each other.
REFERENCE SIGNS LIST
21 inner surface
22 , 25 track groove
22 a track inlet end
24 outer surface
25 a track inlet end
27 ball
28 retainer
32 , 33 cutout round portion
36 machining allowance | A fixed type constant velocity universal joint has cutout round portions ( 32 ) provided at two portions of a ball-contact-point corresponding part on a track inlet end ( 22 a ) of each of the track grooves ( 22 ) of the outer joint member for reduce biting of balls. The fixed type constant velocity universal joint is capable of achieving reduction of stress generated when balls and edge portions interfere with each other, suppression of chipping of the edge portions, and prolongation of a service life of the joint as a whole. These advantages are achieved even at a time of an unexpected high-angle operation, and in particular even when an angle expected during use of the constant velocity universal joint is exceeded. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to the data processing field, and more particularly, relates to a method and circuit for implementing Efuse sense amplifier verification, and a design structure on which the subject circuit resides.
DESCRIPTION OF THE RELATED ART
[0002] Electronic Fuses (eFuses) are currently used to configure elements after the silicon masking and fabrication process. These fuses typically are used to configure circuits for customization or to correct silicon manufacturing defects and increase manufacturing yield.
[0003] In very large scale integrated (VLSI) chips, it is common to have fuses, such as eFuses that can be programmed for various reasons. Among these reasons include invoking redundant elements in memory arrays for repairing failing locations or programming identification information.
[0004] When a fuse is sensed, both the sense amplifier and the blown fuse resistance must be within the specification to ensure the proper value is read out. Currently, when testing fuse hardware in the lab, it is difficult to discern the difference between a malfunctioning sense amplifier and an improperly blown fuse. Typically the way to verify a sense amplifier is within specification is to blow a fuse with a resistance equal to that of the smallest resistance the sense amplifier is specified to read as blown.
[0005] The problem with this way of verifying the sense amplifier is that blowing a fuse with such exact resistance is extremely difficult. Fuses are designed to introduce extremely high resistances to the path when blown. Only a small fraction of the fuses will equal the small resistance needed for effective sense amplifier testing. It is quite likely no fuses will have the specific value needed. When this happens, it is impossible to verify the sense amplifier is in specification.
[0006] A need exists for an effective mechanism for verification of a sense amplifier.
[0007] As used in the following description and claims, it should be understood that the term eFuse means a non-volatile storage element that includes either an antifuse, which is a programmable element that provides an initial high resistance and when blown provides a selective low resistance or short circuit; or a fuse, which is a programmable element that provides an initial low resistance and when blown provides a selective high resistance or open circuit.
SUMMARY OF THE INVENTION
[0008] Principal aspects of the present invention are to provide a method and circuit for implementing Efuse sense amplifier verification, and a design structure on which the subject circuit resides. Other important aspects of the present invention are to provide such method and circuit for implementing Efuse sense amplifier verification substantially without negative effect and that overcome many of the disadvantages of prior art arrangements.
[0009] In brief, a method and circuit for implementing Efuse sense amplifier verification, and a design structure on which the subject circuit resides are provided. A first predefined resistor value is sensed relative to a reference resistor. A second predefined resistor value is sensed relative to a reference resistor. Responsive to identifying a respective sense amplifier output resulting from the sensing steps of an unblown eFuse and a blown eFuse, valid operation of the sense amplifier is identified.
[0010] In accordance with features of the invention, the sense amplifier is responsive to failing to identify a respective sense amplifier output of an unblown eFuse and a blown eFuse for identifying out-of-specification sense amplifier operation. A respective select transistor is connected to each eFuse, and a control signal is applied to the respective select transistors for disconnecting each eFuse from the sense amplifier. The first predefined resistor corresponds to a predefined unblown eFuse resistance and the second predefined resistor corresponds to a predefined blown eFuse value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the preferred embodiments of the invention illustrated in the drawings, wherein:
[0012] FIG. 1 is a schematic diagram illustrating an exemplary circuit for implementing sense amplifier verification in accordance with the preferred embodiment;
[0013] FIGS. 2A and 2B are schematic diagrams respectively illustrating an exemplary eFuse cell and exemplary sense amplifier of the circuit of FIG. 1 for implementing sense amplifier verification in accordance with the preferred embodiment;
[0014] FIG. 3 illustrates exemplary steps for implementing eFuse sense amplifier verification in accordance with the preferred embodiment; and
[0015] FIG. 4 is a flow diagram of a design process used in semiconductor design, manufacturing, and/or test.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] In accordance with features of the invention, a method and circuit for implementing sense amplifier verification to enable quickly and accurately determining if an sense amplifier is operating within a defined specification to enable accurately identifying the difference between an unblown fuse and a blown fuse.
[0017] Having reference now to the drawings, in FIG. 1 , there is shown an exemplary circuit for implementing eFuse sense amplifier verification generally designated by the reference character 100 in accordance with the preferred embodiment. Sense amplifier verification circuit 100 includes an eFuse array 102 including a plurality of eFuse cells 104 . Sense amplifier verification circuit 100 includes an eFuse array 102 including a plurality of eFuse cells 104 with multiple or 2 N -1 eFuse cells 104 connected to each bitline of a plurality of bitlines 0 -M. The eFuse array 102 contains X number of eFuse cells 104 , where X equals the number of wordlines (or 2 N -1) multiplied by the number of bit lines. Sense amplifier verification circuit 100 includes fuse blow logic 106 and a sense amplifier 108 associated with each bitline 0 -M. Sense amplifier verification circuit 100 includes a wordline decoder 110 for addressing a wordline input to the multiple eFuse cells 104 connected to each bitline.
[0018] In accordance with features of the invention, a control function or circuit 112 generates a plurality of control signals B_ENABLE, U_ENABLE, and REFERENCE_ENABLE that are applied to the sense amplifier 108 for implementing eFuse sense amplifier verification in accordance with the preferred embodiment. Two resistors are provided in accordance with features of the invention, one of resistance U to impersonate an unblown fuse and one of resistance B to impersonate a blown fuse. U_ENABLE and B_ENABLE signals select the fuse impersonating resistors. REFERENCE_ENABLE is used to select the reference resistor.
[0019] In accordance with features of the invention, the control function 112 generates a control signal SA_T that is applied to the wordline decoder 110 for implementing eFuse sense amplifier verification in accordance with the preferred embodiment. The control signal SA_T is provided to deactivate all the word lines so no eFuses are connected to the bitline and then a selected resistor of value U or B is activate in its place. The control signal SA_T deactivates the word lines.
[0020] FIG. 2A illustrates an exemplary eFuse cell 104 of the sense amplifier verification circuit 100 . Each fuse cell 104 includes a respective NFET 204 connected in series with an eFuse 206 connected between a bitline and connected via ground. A respective wordline input WL is applied to a gate input of each NFET 204 .
[0021] FIG. 2B illustrates an exemplary sense amplifier 108 for implementing eFuse sense amplifier verification in accordance with the preferred embodiment. Sense amplifier 108 includes a sense amplifier circuit 202 used for an electronic fuse, or eFuse cell 102 to determine if the eFuse 206 is a blown or an unblown fuse, for example, providing an output DOUT of a logical “0” or logical “1”. Sense amplifier 108 includes a pair of respective resistor pull-up devices 210 connected between a positive voltage supply rail VDD and a first sensing node SA 0 and a second sensing node SA 1 . Sense amplifier 108 includes a pair of respective resistors 212 , 214 coupled to the first sensing node SA 0 , one resistor 212 having a first resistance B to impersonate a blown fuse and one resistor 214 having a second resistance U to impersonate an unblown fuse. Sense amplifier 108 includes a reference resistor 216 coupled to the second sensing node SA 1 . A respective N-channel field effect transistor (NFET) 218 , 220 , 222 is connected between the resistors 212 , 214 , 216 and the first sensing node SA 0 , and the second sensing node SA 1 . A respective one of the control signals B_ENABLE, U_ENABLE, and REFERENCE_ENABLE is applied to a gate input of the respective NFETs 218 , 220 , 222 to select the B ohm resistor 212 , U ohm resistor 214 , and the reference resistor 216 .
[0022] As shown in FIGS. 1 , 2 A, and 2 B, each of the eFuse cells 104 on a bitline shares a sense amplifier 108 . The number of sense amplifiers 108 equals the number of bitlines 0 -M. When performing a sensing operation, each sense amplifier 108 will contribute one bit to the fuse data on the output bus. In normal operation one wordline WL and one reference resistor 216 is selected. This connects one eFuse 206 and one reference resistor 216 per bitline to its corresponding sense amplifier 108 , which creates a respective voltage divider between one pull-up resistor 210 and the selected reference resistor 216 and the other pull-up resistor 210 and the selected eFuse 206 . The s sense amplifier circuit 202 evaluates the difference between the two voltage dividers and consequently determines if the selected eFuse 206 has a larger or smaller resistance compared to the reference resistor 216 . To determine the difference between an unblown fuse and a blown fuse, the reference resistor 216 has a resistance higher than an unblown fuse but lower then a blown fuse.
[0023] The method for implementing sense amplifier verification in accordance with the preferred embodiment includes two sensing operations. One sensing operation is completed, for example, with SA_T=1, U_ENABLE=1, B_ENABLE=0, and REFERENCE_ENABLE=1. This operation includes a voltage divider between the pull-up resistor 210 and the selected U ohm resistor 214 connected to node SA 0 and a voltage divider between the other pull-up resistor 210 and the selected reference resistor 216 connected to node SA 1 . Sense amplifier circuit 202 evaluates the difference between the two voltage dividers and determines if the U ohm resistor 214 has a larger or smaller resistance compared to the reference resistor 216 to detect either an unblown fuse or a blown fuse. If DOUT shows that the fuse is unblown, then this first sensing operation of the sense amplifier 108 shows operation within specification to validate this operation of the sense amplifier. A second sensing operation is then completed with SA_T=1, U_ENABLE=0, B_ENABLE=1, and REFERENCE_ENABLE=1. This operation includes a voltage divider between the pull-up resistor 210 and the selected B ohm resistor 212 connected to node SA 0 and a voltage divider between the other pull-up resistor 210 and the selected reference resistor 216 connected to node SA 1 . If DOUT also shows that the fuse is blown, the operation of the sense amplifier 108 is completely validated.
[0024] Referring also to FIG. 3 , there are shown exemplary steps for implementing sense amplifier verification in accordance with the preferred embodiment starting at a block 300 . As indicated at a block 302 , the control signals are set to SA_T=1, and REFERENCE_ENABLE=1, to deactivate all eFuse cells 104 with the wordlines gated and to select the reference resistor 216 . As indicated at a decision block 304 , it is determined to test sensing a blown fuse or an unblown fuse operation. When testing an unblown fuse, then the control signals are set to U_ENABLE=1, B_ENABLE=0 as indicated at a block 306 . Then a sense operation is performed as indicated at a block 308 . Checking whether the fuse sensed as unblown is performed as indicated at a decision block 310 . If the sensed output DOUT shows that the fuse is unblown, then this first sensing operation of the sense amplifier 108 shows operation within specification as indicated at a block 312 . Otherwise if the sensed output DOUT shows that the fuse is blown, then the sense amplifier is out of specification and fails as indicated at a block 314 .
[0025] When testing to verify a blown fuse operation, then the control signals are set to U_ENABLE=0, B_ENABLE=1 as indicated at a block 316 . Then a sense operation is performed as indicated at a block 318 . Checking whether the fuse sensed as blown is performed as indicated at a decision block 320 . If the sensed output DOUT shows that the fuse is blown, then this second sensing operation of the sense amplifier 108 shows operation within specification as indicated at a block 322 . Otherwise if the sensed output DOUT shows that the fuse is unblown, then the sense amplifier is out of specification and fails as indicated at a block 324 .
[0026] FIG. 4 shows a block diagram of an example design flow 400 . Design flow 400 may vary depending on the type of IC being designed. For example, a design flow 400 for building an application specific IC (ASIC) may differ from a design flow 400 for designing a standard component. Design structure 402 is preferably an input to a design process 404 and may come from an IP provider, a core developer, or other design company or may be generated by the operator of the design flow, or from other sources. Design structure 402 comprises circuits 100 , 104 , 108 in the form of schematics or HDL, a hardware-description language, for example, Verilog, VHDL, C, and the like. Design structure 402 may be contained on one or more machine readable medium. For example, design structure 402 may be a text file or a graphical representation of circuit 100 . Design process 404 preferably synthesizes, or translates, circuits 100 , 104 , 108 into a netlist 406 , where netlist 406 is, for example, a list of wires, transistors, logic gates, control circuits, I/O, models, etc. that describes the connections to other elements and circuits in an integrated circuit design and recorded on at least one of machine readable medium. This may be an iterative process in which netlist 406 is resynthesized one or more times depending on design specifications and parameters for the circuit.
[0027] Design process 404 may include using a variety of inputs; for example, inputs from library elements 408 which may house a set of commonly used elements, circuits, and devices, including models, layouts, and symbolic representations, for a given manufacturing technology, such as different technology nodes, 32 nm, 45 nm, 90 nm, and the like, design specifications 410 , characterization data 412 , verification data 414 , design rules 416 , and test data files 418 , which may include test patterns and other testing information. Design process 404 may further include, for example, standard circuit design processes such as timing analysis, verification, design rule checking, place and route operations, and the like. One of ordinary skill in the art of integrated circuit design can appreciate the extent of possible electronic design automation tools and applications used in design process 404 without deviating from the scope and spirit of the invention. The design structure of the invention is not limited to any specific design flow.
[0028] Design process 404 preferably translates an embodiment of the invention as shown in FIGS. 1 , 2 A, 2 B, and 3 along with any additional integrated circuit design or data (if applicable), into a second design structure 420 . Design structure 420 resides on a storage medium in a data format used for the exchange of layout data of integrated circuits, for example, information stored in a GDSII (GDS2), GL1, OASIS, or any other suitable format for storing such design structures. Design structure 420 may comprise information such as, for example, test data files, design content files, manufacturing data, layout parameters, wires, levels of metal, vias, shapes, data for routing through the manufacturing line, and any other data required by a semiconductor manufacturer to produce an embodiment of the invention as shown in FIGS. 1 , 2 A, 2 B, and 3 . Design structure 420 may then proceed to a stage 422 where, for example, design structure 420 proceeds to tape-out, is released to manufacturing, is released to a mask house, is sent to another design house, is sent back to the customer, and the like.
[0029] While the present invention has been described with reference to the details of the embodiments of the invention shown in the drawing, these details are not intended to limit the scope of the invention as claimed in the appended claims. | A method and circuit for implementing Efuse sense amplifier verification, and a design structure on which the subject circuit resides are provided. A first predefined resistor value is sensed relative to a reference resistor. A second predefined resistor value is sensed relative to a reference resistor. Responsive to identifying a respective sense amplifier output resulting from the sensing steps of an unblown eFuse and a blown eFuse, valid operation of the sense amplifier is identified. | 6 |
RELATED APPLICATIONS
This application is a continuation of application Ser. No. 115,678, filed Jan. 28, 1980 now abandoned.
This application is a continuation-in-part of U.S. patent application, Ser. No. 895,239, filed Apr. 10, 1978, which issued as U.S. Pat. No. 4,247,517 on Jan. 27, 1981 which is a continuation-in-part of U.S. patent application, Ser. No. 821,042, filed Aug. 1, 1977 which issued as U.S. Pat. No. 4,251,482 on Feb. 17, 1981, which is a continuation-in-part of U.S. patent application, Ser. No. 734,228, filed Oct. 20, 1976, which was abandoned in favor of continuation application, Ser. No. 923,359, filed July 10, 1978 which is now abandoned in favor of continuation application Ser. No. 144,068, filed Apr. 28, 1980, application 734,228 being a continuation-in-part of U.S. patent application, Ser. No. 703,044, filed July 6, 1976 which issued as U.S. Pat. No. 4,196,166 on Apr. 1, 1980, which is a continuation-in-part of U.S. application, Ser. No. 640,824, filed Dec. 15, 1975, which was abandoned in favor of continuation application, Ser. No. 827,992, filed Aug. 26, 1977 which issued as U.S. Pat. No. 4,149,650 on Apr. 17, 1979.
BACKGROUND OF THE INVENTION
This invention relates to an improved system for storing items while they are being sterilized, while they are being stored awaiting use, while they are in the process of being used, and after they have been used and are waiting resterilization. The invention particularly relates to a system having an improved actuator for automatically releasing a container lid at a predetermined temperature, an improved gasket for the container and an improved relief valve for the container. The system is particularly useful in connection with the sterilization and storage of medical items, such as surgical instruments.
As explained in the above-referenced patent applications, a need exists for an improved system for sterilizing surgical instruments and other medical items in that the common method of wrapping articles in sheets, sterilizing them and then storing them while still in the sheets, is an unsatisfactory approach. Scientific studies have shown that thirty percent of the packs prepared with sheets are contaminated by bacteria at the time of use. Further, instruments in such packs using sheets are contaminated with lint.
In the most recently filed patent application referred to above, articles to be sterilized are placed in a container, and the container is placed in an autoclave with the lid held open. After the articles have been sterilized, a pressure responsive actuator automatically releases the lid and allows it to fall into a closed position wherein a resilient gasket prevents further flow into the container. The actuator utilizes an expandable chamber which responds to pressure changes to produce an actuating movement. In a preferred approach, a quantity of sterilizing fluid is captured within the chamber by means of a temperature responsive valve. Although the systems disclosed in the earlier applications are valuable approaches, further improvements have been made in connection with a production version of the system.
SUMMARY OF THE INVENTION
A support plate is mounted on the periphery of a container base, and a projection or other support means on the support plate holds the lid in open position. A bellows or other suitable expandable chamber is mounted on the support plate; and at the end of the sterilizing phase of the autoclave cycle a chamber expands against the lid to force the support means away from the lid and allow it to fall onto the base. Advantageously, the support plate may be molded as a one-piece, relatively stiff plastic member, with means on its lower end for mounting on the periphery of the container base. In a preferred approach, the support plate has a pair of projections which extend beneath the edge of the lid to hold it in open position. A thin diaphragm in the form of a bellows construction is secured to the plate so that the diaphragm in combination with the plate uniquely forms the expandable chamber. Further, the support plate is provided with an inlet nipple that extends into the expandable chamber to permit steam or other sterilizing fluid to enter the chamber during the sterilizing phase of the autoclave cycle. A heat shrinkable sleeve valve element surrounds the nipple to close the chamber during the sterilizing phase to capture a volume of fluid in the chamber.
As the lid falls onto the base, it is critical that a seal be provided to prevent further flow into the container. A resilient gasket carried by the lid is formed with a lower flap having a feathered edge which engages a mating surface in the base to provide this initial seal. As a vacuum is formed in the container either by a final vacuum in an autoclave cycle or by the cooling of the residual environment in the container, the gasket is further compressed between the lid and the base. An enlarged bead on the gasket is compressed between the lid and the base to form a second seal for the container. Thus the container contents are sealed and preserved in a sterile, lint-free environment.
Because of the excellence of the seal obtained with the gasket, a vacuum is maintained in the container for an extended period of time. Consequently, to remove the lid of the container, it is necessary to release the vacuum. This is accomplished by providing a manually operated relief valve which plugs into a hole in the lid. During this operation, air rushes into the container. Since the lid is normally removed in an area which is not totally sterile, there is a potential source of contamination. To minimize this effect, the relief valve of the invention incorporates a small filter that removes dust and most other particles in the air. When the vacuum in the container is to be relieved, it is only necessary to pull on a tab attached to the valve flange to expose the valve opening and allow air to enter.
The container is constructed to withstand atmospheric pressure when a very high vacuum exists within the container. Nevertheless, with very large containers it is desirable to provide some additional supporting structure as a safety precaution. Thus, as another feature of the invention, an instrument basket positioned in the container is arranged to support the lid. Further, the basket may be provided with a cone-shaped projection extending upwardly from its bottom wall toward the container lid, or such projection may be formed on either a lid or the base and used with or without a basket. Thus, if the lid should commence to buckle due to the pressure, the support cone will distribute the load and limit the inward movement.
SUMMARY OF THE DRAWINGS
For a more thorough understanding of the invention, refer now to the following detailed description and drawings in which:
FIG. 1 is a perspective view of the overall container showing the lid of the container held in an open position;
FIG. 2 is a side elevational view of the container of FIG. 1, partially cut away;
FIG. 3 is a side elevation of the container of FIG. 2 after the lid has fallen into closed position;
FIG. 4 is a fragmentary, perspective view of one end of the container base;
FIG. 5 is a fragmentary, cross-sectional view of the container base of FIG. 4 showing the lid and gasket positioned on the base, when the other end of the lid is held in an open position;
FIG. 6 is a perspective, exploded view of the expandable chamber actuator and a fragment of the container base illustrating the manner in which the actuator is mounted on the base;
FIG. 7 is a view like FIG. 6 but with the actuator mounted on the base and the chamber expanded;
FIG. 8 is a cross-sectional view of the expandable chamber showing the expanded position of the chamber in phantom lines;
FIG. 9 is a cross-sectional view of the inlet valve of the expandable chamber showing the valve in closed position;
FIG. 10 is a fragmentary view of the container showing the actuator in side elevation on the container base and holding the lid open showing the lid, base and gasket in cross-section;
FIG. 11 is a cross-sectional view of the gasket free form;
FIG. 12 is a cross-sectional view of the gasket mounted on a portion of the lid, also shown in cross-section;
FIG. 13 is a cross-sectional view of a portion of the lid, gasket and base with the lid in closed position on the base;
FIG. 14 is a perspective view of the relief valve for the sterilizing container;
FIG. 15 is a cross-sectional view of the valve of FIG. 14 installed in an opening in the container lid; and
FIG. 15b shows the valve with a vacuum in the container;
FIG. 16 is a perspective view on the upper side of the valve of FIG. 14 showing the valve held in open position; and
FIG. 17 is a side view partially sectionalized showing a support cone in the container basket illustrating the relation between the cone, basket cover, and the container lid.
DETAILED DESCRIPTION
Referring now to FIGS. 1 and 2, there is shown a container 10 having access means or a lid 12 closing the open upper side of a base 14, with a gasket 16 carried by the lid and extending between the base and the lid. The container illustrated has a generally oval or racetrack configuration with the container lid having a somewhat dome-shape for strength purposes. Other configurations, such as circular, could also be employed. The upper portion of the lid is shaped to mate with recesses in the container base to facilitate stacking of the containers.
One end of the lid 12 is held open by an actuator 18 which is mounted on the base 14. The actuator includes a bellows-like inflatable chamber 20 which operates to release a lid at a desired point in an autoclave sterilizing cycle, allowing the lid to drop to the position shown in FIG. 3. FIG. 2 also shows a basket 22 and cover 23 within the container for holding items to be sterilized and to add support to the container when a vacuum exists in it. One suitable material for the container is polysulfone which is sold by Union Carbide Company.
The basket includes a plurality of holes 24 spaced around the lower side wall of the basket, to permit sterilizing fluid to circulate and to allow air to escape. Also provided are a plurality of drain holes (not shown) in the basket bottom wall to permit condensation to drain from the basket. Referring to FIG. 5 it may be seen that the container base 14 includes a bottom wall 14a which slopes downwardly and outwardly to a shoulder 14b leading to a peripheral groove 15. The bottom wall 14c of the groove 15 also slopes slightly downwardly in the outward direction to insure that condensation will flow through the drain holes in the basket and drain holes 26 in the base, shown in FIG. 2. The periphery of the base includes an upwardly and outwardly sloping wall 14d terminating in a generally horizontal flange 14e.
The base is formed with protuberances 14f to help guide the lid into its proper position when it is being installed, as shown in FIG. 1, and to help prevent the lid from being improperly positioned on the base. FIG. 5 shows the condition of the gasket, lid and base on the left end of the container when the right end of the container is held in open position as shown in FIG. 1.
Referring to FIGS. 6 and 7, it may be seen that the actuator 18 includes a plate-like member 28 having on its lower end a tab 30 which snaps into a slot 32 formed in the base flange 14e on the right end of the container as shown in FIG. 1. The actuator 18 further includes a pair of projections or posts 34 which extend outwardly from the plate 28. The plate 28 is preferably formed as a one-piece plastic member formed in a single molding operation.
Referring to FIG. 10, it may be seen that the tab 30 on the plate 28 includes one or more detents 30a which require the tab 30 to be snapped into position through the slot 32 in the flange 14e. This attachment coupled with the sides of the slot 32 in the somewhat horizontal wall 31 on the plate 28 support the actuator plate in a position extending upwardly approximately as shown in somewhat cantilever fashion. As can be seen the post-like projections 34 on the support plate 28 connect to the lid 12 by extending beneath the gasket 16 on the lid. Actually, with the lid removed but with the support plate mounted on the base as shown in FIG. 10, the upper end of the support plate will move further than shown in FIG. 10 towards the lid 12. This insures that the lid is securely supported when the container is placed in an autoclave. Note from FIG. 10 that the support plate 28 extends inwardly towards the lid at its upper end as opposed to being completely vertical.
The support plate 28 provides a number of different characteristics. First, it should be sufficiently stiff and strong to support the lid and to provide the necessary reliability. In addition it should be relatively inexpensive so that it may be disposable. Molding the support plate 28 in a single operation with its multiple functions greatly contributes to this. In order to minimize the amount of material required and yet attain the necessary stiffness and flexibility, the plate may be formed with a plurality of gussets 33 extending between the horizontal wall 31 and the approximately vertical portions of the plate. Similarly, the edges of the upright portion may be thickened or ribbed to provide the necessary strength.
Referring to FIG. 8 as well as to FIG. 6, it may be seen that the expandable chamber 20 is partially formed by a portion of the support plate 28. More specifically, the upper portion of the support plate is molded with a circular recess of two different diameters. The outer portion includes a cylindrical wall 36 and an annular wall 38, which is further connected to a smaller diameter cylindrical wall 40 which is joined to a circular end wall 42. Together these walls form a cup-shaped recess.
The expandable portion of the chamber 20 is formed by separate bellows-like element 44 molded of a plastic material similar to that from which the plate 28 is molded but being of thinner cross-section and being more flexible. As can be seen the diaphragm 44 includes an outer cylindrical wall 44a connected to an annular wall 44b which mate with the walls 36 and 38 on the plate 28. These walls are joined by suitable means to form the expandible chamber 20. The diaphragm 44 further includes short cylindrical wall sections 44c, 44d and 44e with consecutively smaller diameters joined by connecting wall sections 44f and 44g. A central circular wall section 44h connected to the cylindrical wall 44e forms an end wall of the chamber. As can be seen from the phantom lines in FIG. 8, the diaphragm 44 assumes the position indicated when the chamber is fully expanded. Note that the cylindrical walls maintain their approximate configuration but are moved outwardly due to the flexibility of the connecting annular wall sections 44f and 44g.
The support plate 28 includes a tubular portion or nipple 46 which is formed integral with the wall 42 and projects into the chamber 20. The inner end of the nipple is closed but a plurality of ports 48 in the side wall of the nipple connect the chamber 20 to the space around it. The nipple 46 tapers slightly inwardly to facilitate a single molding operation for the plate 28 and the ports 48 are formed at an angle to the side wall of the nipple so that the ports may also be made during the molding operation. That is, the mold structure forming the interior of the nipple and the ports may be withdrawn from the back side of the plate 28 at the completion of a molding operation. The material forming the plate is somewhat flexible to permit such.
Positioned loosely over the nipple 46 is a cylindrical sleeve 50 made of heat-shrinkable material. Although the sleeve is relatively confined within the chamber, it may be more positively secured to the plate 42 by a small amount of adhesive on the end of the sleeve.
Referring to FIG. 11, the gasket 16 provides a critical function requiring very flexible resilient material formed in a specific design. The gasket 16 includes an upper generally cylindrical portion 16a having on its upper edge a thickened bead adding to strength. The lower end of the portion 16a is connected to the upper leg 16b with a central section which takes a generally U-shape when installed on the lid. In addition to the leg 16b, this includes an annular wall 16c and a lower leg 16d, which in its free form shape extends somewhat downwardly. The outer end of the leg 16d is thickened to form a sealing bead 16e which leads to a thin flap 16f which tapers to a feathered lower edge. Note that there is a rather acute angle 17 between the flap 16f and the back side of the bead portion 16e.
As may be seen from FIG. 12, the gasket 16 mounts on an outwardly extending flange 12a formed on the lower end of the lid 12. The outer upper surface of the flange 12a is rounded as shown in FIG. 12 while the lower outer edge of the flange 12a is generally flat to mate with the gasket leg 16d when the lid is seated as shown in FIG. 13. The juncture between the flange 12a and the remainder of the lid 12 on the inner surface of the lid is smoothly rounded as can be seen from FIG. 12. Note also that the vertical thickness of the flange 12a is slightly greater than the wall thickness at the outer extremity of the flange. As seen from FIG. 12, positioning the gasket on the lid flange causes the gasket leg 16d to move upwardly somewhat so that the walls 16b, 16c and 16d move closer to a U-shape. The gasket assumes this configuration where ever it can hang free on the lid 12. In other words, referring to FIG. 1, the gasket would assume the position shown in FIG. 12 throughout its periphery except that the gasket on the left end of the container will appear approximately as shown in FIG. 5 and the gasket on the right end of the container in the area of the support actuator 18 will be as shown in FIG. 10.
OPERATION
When the container is first placed in the autoclave, the actuator will be in the position shown in FIGS. 1 and 10 holding the lid open and the expandable chamber 20 will be in the position shown in FIG. 8. If the particular autoclave cycle being used includes one or more preliminary vacuum phases to withdraw air from the containers, no movement of the actuator will occur, since the port 48 and the valve for the inflatable chamber 20 are open and not covered by the sleeve 50. Any pressure changes within the autoclave will be automatically applied to the interior of the chamber as well. When a high temperature sterilizing fluid such as gas or steam is applied to the autoclave, the fluid flows into the interior of the container and through the open lid into the interior of the basket through the ports 24, to displace the air and sterilize the container and the basket contents. Since the gasket 16 is positioned on the lid 12 relatively loosely, it has been found that the sterilizing fluid will also effectively sterilize the lower surfaces of the lid and the surfaces of the gasket.
The sterilizing environment applied to the container will of course also enter the chamber 20 through the ports 48. The elevated temperature of the fluid will cause the sleeve-like valve element 50 to shrink and cover the ports 48, as shown in FIG. 9. The high temperature, high pressure fluid is thus captured in the chamber. No change however occurs in the volume of the chamber during the remainder of the sterilizing phase, since temperature and pressure surrounding the chamber is essentially the same as that within it. Most autoclaves have some minor variations in temperatures and pressures during the sterilizing phase but such variations are not significant enough to cause the actuator to perform its actuating function. Thus, during the entire sterilizing phase, the lid of the container remains raised on one edge from the base such that fluid can flow freely into and out of the container. It is important that the lid be raised sufficiently to permit the sterilizing fluid to circulate freely and displace the air in the container. Preferably the lid should be raised at least a third of the height of a dome-shaped lid. It is also important that the circulation holes 24 in the basket be sized and spaced to permit the sterilizing fluid to displace the air in the basket. Condensation drains from the basket 22 through the holes in the bottom, and from the container through the drain holes 26 in the container base 14.
At the completion of the sterilizing phase of the cycle, there is an immediate pressure drop. Temperature also drops but this is much more slowly. As the pressure drops in the autoclave, the expandable chamber 20 expands due to the fact that the pressure of the steam captured within the chamber is greater than the pressure surrounding it. Thus, the bellows-like diaphragm 44 of the chamber 20 will move to the configuration shown in phantom lines in FIG. 8 and shown in solid lines in FIGS. 3 and 7. Since the central wall 44th of the diaphragm 44 is engaging the outer edge of the lid or its gasket, 16, as shown in FIG. 10, the actuator plate 28 is urged to pivot in a clockwise direction into the phantom line position shown in FIG. 10, this position also being shown in FIG. 3. The actuator moves because the resistance to movement provided by cantiliver mounting arrangement is much less than that of the lid 12. Thus, as the actuator moves, its projections or posts 34 are withdrawn from beneath the lid, allowing it to fall. Note from FIG. 8, that the wall 44h of the diaphragm 44 extends beyond the tip of the projections 34 when the bellows is fully expanded. This insures that the lid will be released. With the lid released, the actuator will move back slightly somewhat towards the upper portion of the container lid, as shown in FIG. 3, but this movement is somewhat limited while the expandable chamber is still expanded.
The lid falls into the proper position on the base and the gasket 16 assumes the approximate position shown in FIG. 13. The sloping wall 14d helps guide and lid into the peripheral groove 15 and the surfaces of the groove are smoothly curved to facilitate proper positioning of the lid. Correspondingly, the extremely flexible and resilient flap 16f on the gasket insures a proper seal on a reliable basis. In a gravity-type autoclave cycle wherein there is no final vacuum phase for withdrawing residual sterilizing environment from the autoclave, a vacuum is nevertheless formed within the container as the residual environment within the container cools and condenses, and as atmospheric pressure is introduced into the autoclave surrounding the container. The pressure differential between the interior and the exterior of the container may be quite small for a period of time in some situations such that it is important that a gasket prevent flow into the container at this time and the feathered edge of the gasket performs this function. At the same time, if the pressure within the container should be temporarily greater than the pressure on the outside of the container, the gasket feathered edge will readily permit flow out of the container, thus acting like a one-way valve. As the pressure on the interior of the container drops relative to the exterior atmosphere pressure, the lid is drawn more tightly against the base thus compressing the gasket more. This causes the bead 16e of the gasket to be further compressed between the lid and the base, becoming the primary seal for the container.
If the container is utilized in an autoclave providing a final vacuum phase, the residual environment in the autoclave is quickly withdrawn and the residual environment within the container is likewise withdrawn past the feathered edge of the gasket. When atmospheric pressure is introduced into the autoclave, the feathered edge of the gasket prevents flow into the container; and a quickly produced pressure differential between the interior and exterior of the container compresses the gasket greatly so that the bead 16e seals the container more tightly. Consequently, the container contents are sealed in essentially atmosphere free sterile environment, until the contents are to be used.
When the container is removed from the autoclave, the actuator 18 may be manually removed from the slot 32 in the container base and discarded. It is convenient to have a disposable type in a hospital environment, and the economics are such that this is a very practical approach. Alternatively, the actuator could be recycled by installing a new temperature responsive value in the expandable chamber, or by employing a value of a type that would recycle automatically. As one example the nipple 46 could be made as a separate component and be removably attached to the plate, and thus could be removed to permit replacement of the value element 50 and then reinstalled. Such an approach might be most practical, if sterilization of the container and their contents is to be performed by specialists at a central location.
The container and its contents are then transported to a storage area or to the point where the contents are needed. In use, the container is typically moved to the general area of use, but the lid of the container is actually removed somewhat remote from the actual operating or other use area in that the exterior of the container is contaminated during storage. When the lid is removed, the sterile basket on the interior protects the contents from falling dirt or other particles. The basket is carried to the actual area of use, and the cover on the basket is removed to provide access to the instruments or other items within the basket. This approach provides maximum sterility.
Relief Valve
Because of the high vacuum within the container, it is impossible to remove the container lid without relieving the vacuum. For this purpose, the relief valve 60 shown in FIGS. 1, 14, 15 and 16 is provided. As seen from FIG. 1, the relief valve is located in the top wall of the lid 12; however, it should be recognized that such a valve can be placed in other locations as well. Referring to FIG. 14, the valve is made of flexible resilient material as a one-piece member except for an inner filter 62. The valve includes a generally tubular projection or plug 64 which is open on its lower end and enclosed by an enlarged resilient flange 66 on its upper or outer end. A passage 68 through the projection 64 opens to a port 70 in a side wall of the projection immediately beneath the flange 66.
In use, the projection 64 is inserted through an opening in the lid 12. This operation is performed with the rigid, metal foam filter removed. The filter 62 is then installed in the lower end of the plug portion 64 as shown in FIG. 15. This not only secures the filter within the plug extending across the passage, but also helps pull the valve in a sealed condition in combination with a ring 65 on the exterior of the plug. The normal position of the valve when the container is not vacuumized is as shown in FIG. 15 with the annular edge 66a of the flange 66 against the outer surface of the lid thus preventing flow into the container through the port 70 and passage 68.
When the container lid 12 moves to its closed position, the valve 60 prevents air flow into the container; and as a vacuum is formed within the container, the exterior pressure forces most of the lower surface of the valve flange 66 against the lid. The annular relief groove 69 in the upper surface of the flange 66 and the annular groove 67 in the lower surface adjacent the plug 64 enable the flange to flatten readily. In addition, the thin upper wall 66b of the flange covering the end of the passage 68 is drawn inwardly because of the vacuum. This provides visible indication to an observer that a vacuum condition exists in a particular container.
When the vacuum is to be released to enable the container lid to be withdrawn, a tab 74 is manually pulled to lift the edge of the flange 66 away from the lid so that air may flow into the port 70 and through the passage 68 in the valve. If desired, the tab may be hooked on a tab holder 76 as shown in FIG. 16. This may be convenient in that the filter 60 is so fine that it will take several seconds for the pressure to equalize in a large container. All of the air entering the container must of course pass through the filter 62. Consequently, even though the entering air has not been subjected to high temperature sterilization, a high percentage of the dust, lint and other particles within the air are removed as the air passes through the filter. Once the container interior and exterior equalize, the lid can be lifted off of the base to provide access to the inner gasket.
Lid Support
Although the container 10 is constructed to withstand a high vacuum, it has been found desirable to provide further mechanical support for large containers. A preferred approach for providing such support is illustrated in FIG. 17. The basket cover 23, which is supported on its periphery by the basket base 22, is dimensioned so that its upper surface mates with the lower surface of the lid 12; and normally with a container lid tightly closed on a container base, the lid would be slightly spaced from the inner basket. However, if an overstressed condition should occur, such that the lid 12 should begin to buckle, it will engage the upper surface of the basket cover 23 to be supported thereby.
Further, with particularly large containers, the lower portion of the inner basket 22 is provided with an upwardly extending cone-shaped projection 78 that terminates near the cover 23 of the basket. The periphery of the basket cover 23 rests on the basket base 22, but it also engages or comes close to engaging the upper end of the support cone. The container lid 12 is formed with recesses that are complementarily receives in the basket cover. Thus in the overstressed situation the basket cover will reset upon the upper end of the support cone 78 on the basket base, thus preventing collapse of the lid. Of course, a suitable support may be provided as a separated element, or attached to either the container lid or base, and used without a basket; or used with a modified basket which would fit with a support.
The operation of two different autoclave cycles is briefly discussed above. It is believed that this is sufficient for purposes of understanding the invention. However, if further information is desired, reference may be had to the surface mentioned U.S. patent application Ser. No. 895,239 or Ser. No. 821,042, both of which discuss such cycles in greater details and include a time, temperature and pressure graph of such operations.
Although the container is primarily designed for use with a steam or gas autoclave sterilizing cycle, it should be understood that it is also very useful with other sterilizing techniques. With microwave sterilizing, the container lid may be positioned on the container base in a lightly closed condition. As the contents are heated, any pressure increase within the container may vent from the container past the flexible gasket. When the container cools, a vacuum will be formed in the container, automatically pulling the lid more tightly closed on the container base.
With radiation sterilizing, which does not rely on heat, the container lid is placed on the base in a lightly closed position, and the container is then subjected to a vacuum to withdraw air from the container past the flexible gasket. When pressure around the container is again allowed to increase, the lid will be tightly compressed on the base, since the gasket will prevent a pressure increase in the container. The container is then subjected to radiation, leaving the container contents sterilized and sealed in an essentially atmosphere free environment.
The container may be used for a wide variety of items in addition to surgical instruments. If it is used solely for towels, bandages, and other such somewhat bulky items, it may be convenient to invert the container so that the lid becomes the base, and not use the basket. The side walls of the inverted lid will hold items like towels more easily than will a flat base. The expandable chamber actuator would function in the same manner as described above. Once the container is closed, it could of course be returned to original position for storage and ease of handling. In the inverted position there would be no provision for drainage with the container illustrated; but there would be no drainage with towels. If desired the relief valve in the inverted lid may be modified to be open during the sterilizing phase and then automatically closed in response to temperature. Such a valve is described in the above application, Ser. No. 923,359. In addition to being a drain for condensate, a valve of this type would more importantly allow air to drain from the container as the steam or other sterilizing fluid is applied. | A container lid (12) is held open by a support plate (18) carrying a chamber (20) which expands at a predetermined point in a sterilizing cycle to react against the lid, moving the plate outwardly to permit the lid to drop onto the container base. A resilient gasket (16) prevents fluid flow into the container after the lid is fallen, but permits fluid flow outwardly past the gasket when interior pressure exceeds exterior pressure. When the container is to be opened, a relief valve (60) relieves the vacuum within the container and filters air entering the container at that time. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to kayaks, and in particular, to an accessory pack attached to the kayak deck in front of the kayak cockpit.
Kayaks have become increasingly popular as a method of marine transportation. A kayak is faster and more maneuverable than either a canoe or a rowboat and is not as restricted in use as a sailboat or a motorboat. During kayak operation, it is desirable for the kayak operator to bring with him or her various items such as drinking water, maps, food, fishing rods and fishing accessories, camping gear and other supplies. Items such as maps, cameras, GPS units, cellphones and walkmans, must also be kept dry.
On its own, the kayak does not have readily available internal storage space. What little internal storage space a kayak has is inaccessible during operation. Normal and safe operation of a kayak designed for sea or river operation involves the use of a device known as a spray skirt. The spray skirt, worn around the waist of the kayak operator and physically connected to the cockpit of the kayak, prevents water or spray from entering the cockpit opening. When the spray skirt is employed, the opening is thereby sealed. Any items inside the kayak are inaccessible.
The prior art has on occasion used dry wells formed in the rear deck of a kayak to provide externally accessible dry storage. However, the wells are generally positioned to the rear of the kayak operator and are inaccessible during kayak operation. The prior art has also provided deck rigging comprised of elastic bungee cords crisscrossed to deck loops on the front and/or rear decks of the kayak. A waterproof bag may then be tucked beneath the bungee cords. Accessibility during kayak operation, while difficult, is not impossible. However, the waterproof bags have a tendency to slip around under the cords. The irregular shape of the bags also affects the flow of air and water over the kayak deck increasing the difficulty of maneuvering the kayak.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of devices now present in the prior art, the present invention provides a water-tight, streamlined storage pack, removably attached to a kayak deck and accessible by a kayak operator during kayak operation. The present invention pack also provides lighting and fishing rod holders.
These together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto 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 had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a kayak.
FIG. 2 is a side view of a kayak showing prior art storage areas.
FIG. 3 is a top view of a kayak showing an invention accessory pack attached thereto.
FIG. 4 is a top view of the invention accessory pack.
FIG. 5 is a side view, partly in section, of the accessory pack of FIG. 4 .
FIG. 6 is a front view of the accessory pack of FIG. 4 .
FIG. 7 is a rear view of the accessory pack of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown in FIG. 1 a general depiction of a standard kayak 10 . The kayak 10 has a hull with a front (bow) 11 , a rear (stern) 12 , a top 13 , a bottom 14 and two sides 15 . The kayak front 11 , rear 12 , top 13 , bottom 14 and sides 15 define a hollow interior 16 . The kayak top 13 has at least one cockpit 17 opening through the kayak top 13 into the kayak hollow interior 16 . The kayak top 13 may be further defined as having a forward deck 18 between the cockpit 17 and the bow 11 , and as having a rearward deck 19 between the cockpit and the stern 12 . FIG. 2 illustrates a kayak with prior storage areas. A dry well 2 is formed through the kayak rearward deck 19 . The kayak forward deck 18 has deck rigging 3 comprised of crisscrossed elastic bungee cords. FIG. 3 illustrates an kayak accessory pack 20 constructed according to the principles of the present invention attached to a kayak forward deck 18 .
Referring to the drawings, especially FIGS. 4 through 7 , there is illustrated an accessory pack 20 of the present invention generally adapted to being removably attached to the kayak forward deck 18 . The accessory pack 20 has a front 21 , a rear 22 , a top 23 , a bottom 24 and two sides 25 . The accessory pack front 21 , rear 22 , top 23 , bottom 24 and sides 25 define a hollow interior 26 . The accessory pack front 21 is that portion of the accessory pack nearest the kayak bow 11 . The accessory pack rear 22 is that portion of the accessory pack nearest the kayak cockpit 17 . The accessory pack top 23 may be divided into a forward portion 27 and a rearward portion 28 .
The top rearward portion 28 is comprised generally and substantially of a transparent lid 30 hinged along an approximate dividing line 31 between the top forward portion 27 and top rearward portion 28 . A latch 36 releasably joins the lid rearward edge 32 to the accessory pack top 23 near to the accessory pack rear 22 . A water tight seal 33 is attached to the lid 30 about the lid's perimeter 34 . The lid 30 has a recessed, round well 35 formed centrally therein near to the hinge line 31 , said well 35 adapted especially to hold a cup or bottle. The lid 30 is adapted to provide access to the accessory pack interior 26 by a kayak operator positioned in the kayak cockpit 17 .
The pack top forward portion 28 has an electric switch strip 40 mounted thereon, near to and parallel to the dividing line 31 , said strip containing a plurality of electric switches 41 adapted to control electric power from a battery 42 within the accessory pack interior 26 . The battery 42 is located within the accessory pack interior adjacent the accessory pack front 21 . A light 48 is attached to the pack interior 26 , said interior light 48 being electrically interconnected via a specific switch 41 to the battery 42 . Immediately forward of the strip 40 is a generally rectangular, flat peg board 43 fixedly attached to the pack top 23 . Immediately forward of the peg board 43 , two parallel, side-by-side, running lights 44 are attached to the pack top 23 , said lights 44 being electrically interconnected via specific switches 41 to the battery 42 . The top forward portion 27 also has two, angled, generally cylindrical, fishing rod holders 45 , each holder 45 protruding from the pack interior 26 , through the pack top 23 on each side of the peg board 43 .
The accessory pack 20 has a main light 46 centrally and adjustably attached to said accessory pack front 21 and electrically interconnected via a specific switch 41 to the battery 42 . A number of D-rings 49 are mounted about the accessory pack sides 25 and rear 22 , several of which are adapted to provide attachment of tie down, nylon web straps 47 about the kayak hull, thereby securing the accessory pack 20 to the kayak forward deck 18 . The D-rings 49 also provide means to remove the accessory pack 20 from the kayak 10 and use the accessory pack 20 as a backpack for portage.
The accessory pack bottom 24 may be laterally curved to better fit against the kayak forward deck 18 . It is also desirable to have a section of soft foam 29 attached to the accessory pack bottom 24 . The foam 29 provides an even better fit of the pack 20 against the forward deck 18 and prevents marring of the deck finish.
It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof. | A water-tight, streamlined storage pack, removably attached to a kayak deck and accessible by a kayak operator during kayak operation. The present invention pack also provides lighting and fishing rod holders. | 1 |
The invention described and claimed herein is related to co-pending application Ser. No. 09/433,910 filed Nov. 3, 1999 by the inventor herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for filtering particulates of various sizes from miscellaneous process liquids, and more particularly to an apparatus and method that utilizes a filtration bed formed from super-buoyant media, which has a specific gravity much lower than that of the liquid being filtered.
2. Description of the Prior Art
A preliminary patentability and novelty search regarding the invention described herein has revealed the existence of the following United States Patents:
3,067,358 3,469,057 3,678,240 3,709,362 3,962,557 4,032,300 4,198,301 4,383,920 4,387,286 4,415,454 4,417,962 4,608,181 4,743,382 4,839,488 4,865,734 4,883,083 4,952,767 4,963,257 5,030,353 5,122,287 5,126,042 5,178,772 5,217,607 5,227,051 5,232,586 5,573,663 5,747,311 5,770,080 5,833,867 5,932,092 5,945,005 6,015,497
A careful review of the patents noted above has failed to reveal the concept, apparatus and method disclosed herein.
The need to remove particulates, whether contaminants or products, from process liquids is common to a wide range of processes. In the following description, the focus will be on the removal of particulate contaminants from water-based process liquids, such as swimming pools, aquariums, or sewage treatment effluents, from the deionized water used during electrical discharge machining (EDM), or from aqueous solutions such as the coolants used during conventional machining. However, the same filtration mechanism can be applied to the removal of contaminants from a variety of other process liquids including paints, oils, and hydraulic liquids. The mechanism can also be applied to the filtration and harvesting of particulate materials that form the product(s) of a process and are suspended in a process liquid.
Although a variety of methods have been developed to remove particulates from such process liquids, the most popular method is media filtration. In media filtration, particulate contaminants are strained from the process liquid in one of two ways, either by pumping the contaminated liquid through a unitary permeable element, or by pumping the liquid through a filter bed that is itself composed of small particles.
In permeable element filtration, the liquid is pumped through an element which has pores or channels that allow the liquid to pass through the element but prevent the passage of particulates larger than the pore/channel diameter. Permeable elements comprise a variety of materials, including fabric, paper, ceramic, metal, and plastic. These elements filter the liquid primarily by capturing the contaminant particles on the surface of the element, thus building up a crust or layer of contaminants on the surface. As contaminants accumulate on the surface of the element, liquid flow through the permeable element is reduced because the crust or layer of contaminants acts as an obstruction and because an increasing number of the pores or channels become blocked. As the percentage of blocked pores/channels increases and the crust or layer of contaminants becomes thicker, the pressure required to maintain a specific rate of flow of liquid through the element increases. Eventually, the pressure required exceeds the capability of the pump, or some other system component, and the contaminated element must be replaced with a new element in order to maintain the desired performance of the filtration system.
Alternatively, an attempt may be made to clean the filter element (e.g., by backwashing it with clean liquid or air) to remove the contaminants accumulated on the surface. However, even when the contaminant accumulation on the surface of such an element is removed, there are usually contaminant particles that remain lodged in the permeable element that cleaning is not totally successful in removing. Ultimately, the element must either be replaced with a new element or cleaned in a more rigorous fashion, i.e. by immersion in an acid or base solution to dissolve the contaminants. The more frequently such element replacement or stringent cleaning must be performed, the more costly this filtration process becomes.
In contrast, the second type of media filtration, namely bed filtration, uses a filter bed composed of small particles such as sand or diatomaceous earth, and is one of the most common conventional methods of removing particulate contaminants from liquids. The sand filter uses sand particles that are about 0.35 mm in diameter and fairly uniform in size. Diatomaceous earth filters use a siliceous material formed from the skeletons of small (about 100 microns [μm] in diameter) marine algal cells called diatoms. Both sand and diatomaceous earth filters use media that are substantially heavier than the process liquid being filtered, so that the media sink to the bottom of the filtration vessel forming a bed of filter media. This bed may range from several inches to several feet in thickness. Nominally, in a conventional bed filter, the process liquid is pumped, or allowed to flow (via gravity), downward through this filter bed. As the particulate-laden liquid passes through the bed, the particulates are strained from the liquid and the cleaned liquid exits at the bottom of the bed.
The bed removes the particulate contaminants via one of two processes. First, the larger particulates, which are unable to pass through the spaces between the bed grains, are trapped at the top surface of the bed. This straining effect produces a layer or crust (also called a cake) of large contaminant particles, which builds up on the surface of the bed, a mechanism called surface filtration. This cake can actually enhance the performance of the bed by helping to capture more contaminant particulates, which are retained in the crust itself, because they cannot pass through the spaces between the contaminant particles that form the crust.
Second, smaller particulates, which are carried into the bed by the liquid flow are intercepted by the bed's grains as they follow the convoluted flow pathways taken by liquid as it passes through the bed, a mechanism called depth filtration. Although smaller particulates are captured in the bed material, the smallest particulates may not be captured, as they can continue to flow through the bed and exit with the semi-cleaned liquid at the bottom of the filter bed.
Ultimately, the particulates sequestered by the bed accumulate, making it more difficult for liquid to flow downward through the bed, and thus the flow rate declines. The pressure required to force liquid through the bed then increases, and presents an excellent indication of the growing need to cleanse the bed of the accumulated particulates. Cleansing is achieved by a process of backwashing or back flushing.
During backwashing, clean liquid is vigorously pumped upwards from the bottom of the particulate bed. This upflow of liquid causes the bed to expand slightly, freeing the captured particulates and washing them upwards and out of the bed. As the bed expands, the bed particles have less interference with each other and thus settle faster, matching the up-flow rate of the liquid. This effect prevents the bed particles from being washed out of the bed along with the contaminant particulates. Typical backwash conditions are 5 to 15 minutes duration with the bed volume expanded 15 to 30%.
Although sand and diatomaceous earth filters have been successfully applied to a wide variety of filtration problems, they have a number of limitations and drawbacks. One of the most serious problems involves maintaining bed homogeneity during operation. Inhomogeneities in the bed include, for example, cracks that offer regions of less flow resistance. Such cracks lead to the formation of channels in the bed, poor distribution of the liquid flow through the bed, and thus very low particulate removal. Such inhomogeneities may also allow air to be trapped in the bed, also leading to the formation of channels and poor distribution of the liquid.
In addition, the size and cleanliness of the bed particles are extremely important to the success of the filtration process; a bed composed of large particles allows significant numbers of small particulates to pass through the filter bed along with the process liquid. On the other hand, beds composed of smaller particles can quickly become clogged with small contaminant particles, thus rendering the filter bed ineffective. The bed particles can also adsorb organic compounds on which microorganisms feed. Microbes growing on these organic compounds can bind the filter particles together and clog the bed, thus decreasing its effectiveness and shortening the interval until cleaning.
To maintain cleanliness, large volumes of clean liquid are required to backwash and clean conventional filter beds, leading to large volumes of contaminated liquid which must be treated or properly disposed. Even though backwashing is fairly effective for removing many of the particulates captured by the filter, some particulates may adhere so strongly to the bed particles that they are virtually impossible to remove. These residual contaminants reduce the effectiveness of the filter and significantly impair filter performance. Additionally, the specific gravity of the contaminant particulates is often equal to or greater than the specific gravity of the particles that make up the filter bed. In such circumstances, it is impossible to separate the heavy contaminant particles from the bed particles through a backwash process, and backwashing is therefore not effective as a cleaning method.
Thus, one of the most crucial problems with these systems, which is common knowledge to practitioners of this art, is the ineffectiveness of backwash systems for cleaning the filter media (i.e., Amirtharajah, 1978). As a consequence, in many situations, the contaminated bed cannot be cleaned and instead must be replaced with new bed material. In fact, during normal operation, both sand and diatomaceous earth filters require that the media be discarded after a certain level of media contamination has been reached. In applications that involve heavy particulate contaminant loads in the process liquid, these media may have to replaced on a daily or weekly basis, which is not economical.
An alternative method of bed filtration uses a filter bed composed of buoyant filter media particles. In this method, the media form a bed in which the majority of the media floats just beneath the surface of the process liquid. The process liquid is pumped into the bottom of the filter chamber and flows vertically upward through the bed. As the process liquid passes through the bed, contaminants are filtered from the liquid via the surface and depth filtration mechanisms described above.
Prior applications of this buoyant media method to the filtration of water (e.g., Banks, U.S. Pat. No. 4,885,083, Hsiung, et al., U.S. Pat. No. 4,608,181) have described the use of a filter media with a specific gravity of 0.7 to 0.8 or greater. For example, in Hsiung et al., the media is exactly defined as having a specific gravity of no lower than 0.8 and “most preferably” no lower than 0.9. Banks precisely specifies the specific gravity of buoyant media as 0.75 to 0.9, and “substantially equal to 0.90 to 1.0”.
Nominally, the buoyant media particles used in this type of application are also of a larger diameter than the media particles used in either sand or diatomaceous earth filters. For example, Hsiung, et al. specify the particle diameter as being preferably in the range of 1.5 to 20 mm, in contrast to the sizes of sand particles (about 0.35 mm in diameter) and diatomaceous earth (about 100 microns [μm] in diameter). Due to the relatively large size of the media particles, these buoyant media filter beds are not optimized to remove small particulate contaminants. In general, they are designed to perform larger particulate contaminant removal and some degree of biofiltration of the process liquid by the bacterial biofilm adhering to the media particles.
This buoyant media filter system, as described in the Hsiung et al. patent, actually achieves optimal operation with the media in a partially clean state. In fact, Hsiung et al. write “ . . . it is advantageous to leave a certain amount of deposited solids in a buoyant media filter, as the solids reduce the size of the pores of the filter and assist in filtration”. This requirement is often referred to as “ripening” the filter, and it means that a significant portion of the filtration capability achieved by Hsiung et al. is provided by the contaminant particles that were previously filtered and retained by the media or the microbial biofilm covering the media.
The requirement to use a “ripened” filter media bed dictates that the performance and operation of the media bed cannot be accurately characterized or predicted, as both depend on the amount and nature of the contaminant material(s) previously deposited on the buoyant media particles during the ripening process. This lack of predictable operation makes it very difficult or impossible to develop an optimal design for this type of filter.
In addition, backwashing must be performed in a gentle fashion to preserve the “ripened” layer on the filter media. If the backwash is especially vigorous, particles that were adhering to the buoyant media will be removed from the media and a portion of the buoyant media's filtration capacity would thus be lost. That capacity cannot be regained until the filter has “ripened” by again filtering a sufficient amount of contaminant particles and retaining them in the filter media in order to replenish the loss.
Thus, backwashing is typically performed by gently agitating the bed with air bubbles introduced beneath the bed and allowed to flow upwards through the bed or by gentle streams of water directed into the bed to agitate and dislodge some of the adhering contaminant particles. Accompanied by normal or reduced flow of process liquid through the buoyant media bed, these backwash methods flush only a portion of the retained contaminants from the filter bed.
The backwash system described by Hsiung et al. is the type that uses air injection and the normal flow of raw process liquid to wash excess particulates out of the media. Because the buoyant media particles have a specific gravity close to that of water, it is easy for these gentle agitating mechanisms to move the mostly submerged media around in the process liquid, and thus dislodge some of the contaminant particulates adhering to the media. Consequently, these mechanisms provide the required minimal degree of cleaning of the filter media bed. Using this method of backwashing, the amount of solids flushed from the buoyant media depends on total wash volume. However, because the media particles have a specific gravity close to that of water, they are moved easily by the backwash mechanism, and cannot be thoroughly cleaned.
Unfortunately the problems encountered in using small diameter non-buoyant media, such as sand or diatomaceous earth, are exacerbated when using small diameter buoyant media. Due to the high surface area of the small diameter media, contaminant particles that fill the interstices between the media particles can act like a glue which makes the media particles adhere to one another and form clumps which lead to the formation of non-homogeneities within the bed (just like the problem that occurs in small diameter non-buoyant media). Because the backwash systems must be relatively gentle in nature for the filter to retain its “ripened” state, these non-homogeneities cannot be removed from the bed, and the bed performance declines. This problem dictates that small diameter filter media not be used in buoyant media applications, because the ripening process itself severely limits the efficacy of the filter bed.
In addition, for cost savings, many of these buoyant media filter systems do not employ a separate backwash pump or backwash water storage system. As a result, raw process liquid is used to backwash the bed media. In these designs, maximum cleanliness of the media particles cannot be achieved because a separate, isolated pump and process liquid storage system are not utilized to provide a source of clean process liquid for backwashing. Thus, although such buoyant media filters have desirable characteristics for specific filtration applications, they do not overcome the above-stated disadvantages of conventional media bed filters.
In view of the above disadvantages with conventional apparatuses and methods, it is the principal object of the present invention to overcome the above-discussed disadvantages associated with prior media liquid filtration systems.
Another object of the present invention is to provide a liquid filtration apparatus and method that embodies a filtration bed formed from super-buoyant particles having a specific gravity less than one half that of the liquid being filtered.
A still further object of the invention is to provide a liquid filtration apparatus that embodies a filtration bed that floats on the liquid to be filtered.
Yet another object of the invention is to provide a new and improved filtering system for the removal of particulate contaminants from process liquids which incorporates a high-efficiency back-washable filter bed.
A still further object of the invention is the provision of a liquid filtration apparatus and method that in one aspect incorporates a pair of filtration housings connected in parallel.
Yet another object of the invention is the provision of a liquid filtration apparatus and method that in another aspect incorporates a pair of filtration housings connected in series.
The invention includes other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and drawings. It is to be understood that the invention is not limited to the embodiments illustrated and described, since it may be embodied in various forms within the scope of the appended claims.
SUMMARY OF THE INVENTION
The invention disclosed herein overcomes the disadvantages encountered with prior bed filtration systems by providing a filtering apparatus which incorporates a super-buoyant filter medium having a specific gravity very substantially lower than that of the process liquid being filtered. This requirement permits a majority of the medium to float on top of the process liquid.
In contrast, as described above, previously-described “buoyant media” filters use filter media which are at or near neutral buoyancy in the process liquid, and therefore float with the majority of the media just below the surface of the process liquid. For example, Hsiung et al. specifically define buoyant filter media as having a specific gravity of no lower than 0.8 and “most preferably” no lower than 0.9. Using a specific gravity value of 0.9, the amount of a buoyant media particle that floats above the surface of the process liquid can be calculated using fundamental physical principles.
Based on a specific gravity of 0.9, a sphere 1 cubic centimeter in volume will have a mass of 0.9 grams. If that sphere is placed in water, it will displace 0.9 cubic centimeters of volume. This displacement means that 0.1 cubic centimeter of the sphere, or 10%, will be visible above the surface of the water as shown in FIG. 1 , neglecting surface tension and other effects described below. Thus, 90% of the buoyant media sphere will actually be immersed beneath the water's surface. If several spheres are stacked on top of one another to increase the thickness of the media layer, the relationship remains the same, so that 90% of the media thickness will still be immersed in the water and 10% will be exposed above the water.
In contrast to buoyant media, super-buoyant media form a mass in which the majority of the media floats on top of the process liquid (i.e., in which the media have a specific gravity less than one-half that of the process liquid). For clarity, this difference is illustrated in FIG. 1 . The use of super-buoyant media that float principally on top of the process liquid is a design feature that provides unique capabilities not provided by the buoyant media filter designs described in Hsiung, et al., Banks, Muller et al., or any of the other filtration systems described previously.
It must be emphasized that the distinction between filter media floating submerged beneath the surface of the process liquid and filter media floating on the surface of the process liquid is critical in determining the unique operational characteristics of the each kind of filter. For example, when using buoyant media in water, the filter media (A in FIG. 1 ) behave principally as though they are part of the water mass. Thus any horizontal movement of the water containing such media drags the media along with it. An injection of air bubbles into such a media bed will also move the media particles because they are very close to neutral buoyancy, and this neutral buoyancy renders them easy to move.
In contrast, super-buoyant media filter particles (B in FIG. 1 ) do not behave as though they are part of the process liquid mass. Instead, they form a mass that floats on the surface of the process liquid, largely independent of, and isolated from, the movements of the process liquid beneath. Horizontal movements of the liquid beneath the floating, super-buoyant media have virtually no effect on the media, and thus such movements do not tend to cause significant movement of the super-buoyant media bed. In essence, the super-buoyant media described herein behave much like a cork floating on a water surface.
To achieve this effect, the super-buoyant media particles must have a nominal specific gravity less than 50% of the specific gravity of the process liquid to be filtered. In practice, utilizing a super-buoyant media with the lowest possible specific gravity maximizes the effectiveness of both the filtration and backwashing mechanisms. For example, in the filtration of particulate contaminants from water, good performance can be achieved when the specific gravity of the super-buoyant filter media is less than or equal to approximately 0.25-0.35, but the best performance is achieved when the specific gravity of the super-buoyant media is in the range of 0.01 to 0.05. These super-buoyant media are typically selected from materials such as lightweight plastics (e.g., expanded polystyrene), or hollow microspheres formed from glass or ceramic.
The use of such super-buoyant media insures that nearly all of the bed formed by the filter media floats on top of the surface of the water, with only a minimal amount of the media submerged beneath the surface of the liquid ( FIG. 1 ). This is completely different from the physical behavior of filter beds composed of buoyant media particles described previously. It is also completely unlike the sand and diatomaceous earth filter beds described above for water filtration, neither type of which have any buoyancy in water.
Due to the significant differences in specific gravity between the media and the process liquid, super-buoyant media produce a highly advantageous means of naturally, gravimetrically separating both clean and contaminated filter media and process liquid into separate “phases”. This natural, spontaneous separation is crucial to both sustaining the performance of the filter bed and to maintaining the effectiveness of backwashing such that each backwash cycle produces a reproducibly clean filter bed to insure uniform, predictable filter performance.
The uniqueness of the super-buoyant media approach stems from the fact that when such super-buoyant filter media are used, the aggregate forces acting on the media produce a natural, spontaneous, gravimetric separation of the filter media and the process liquid into two different phases. This occurs in the same manner that a well-agitated mixture of oil and water separates naturally into two distinct phases when a mixture of the two is allowed to reach a static equilibrium. Thus, the super-buoyant media of the filter described here is one of its most novel and unique aspects, as it provides a method for naturally, easily, and efficiently separating the filter media and trapped contaminants from the process liquid.
As described above, implementation of the super-buoyant media method requires that the filter media must float principally on the surface of the process liquid. This requirement is satisfied primarily by selecting media that are much lighter in density than the process liquid. Thus, selection of the appropriate media to implement this filtration method must be initially dictated by the specific gravity of the process liquid. However, selecting media with a low specific gravity is not always sufficient to identify an optimal filter media for filtration of a specific process liquid. Other factors can also influence the effectiveness of the super-buoyant media as a filter for a given process liquid, and therefore must also be considered in selecting the type of filter media.
One of the additional factors in super-buoyant media selection is the attraction of the filter media and the process liquid for one another. For example, when the process liquid is water, hydrophilic filter media (which tend to maximize surface contact with water) will behave in a much different fashion than will hydrophobic filter media (which tend to minimize surface contact with water). Due to the attractive effect, hydrophobic media and the process liquid tend to separate into two phases more quickly. As a consequence, in conjunction with the buoyancy effects described above, hydrophobic super-buoyant media typically provide a better filter in water or a water-based process liquid than will hydrophilic media.
The second factor in selecting the type of super-buoyant filter media is the attraction of the filter media particles to one another. If, for instance, there is a weak electrostatic attraction between the filter media particles, the particles tend to adhere to one another. As a consequence, through selection of media material (e.g., plastic, ceramic, or glass), this electrostatic effect can be utilized to assist the filter media in forming a coherent mass that floats better on the surface of the process liquid, as well as assisting in attraction and removal of contaminant particles from the process liquid. If the electrostatic attraction between the media particles is too great, however, the particles will tend to stick to one another too strongly, thus forming clumps that can cause bed inhomogeneities or interfere with the removal of contaminants from the bed during backwashing. In this later case, it may be necessary to include in the filter housing, a means of electrically grounding the media to remove the charge
The third factor to be considered is the geometric shape of the filter media particles. The filter bed generally works best when the media particles are uniformly spherical in shape as this shape allows the most efficient packing of the media particles. Deviations from a spherical shape can lead to inhomogeneities in the bed, which in turn can decrease the effectiveness of the filter and significantly complicate cleaning of the media.
The final factor that must be taken into account in selecting the type of super-buoyant media is the nature of the process liquid and the physical conditions under which the process functions. Practitioners of the art will easily recognize that there are many organic solvents in which plastic filter media would dissolve, and therefore would not be suitable. In such cases, the use of ceramic or glass microspheres is dictated. In other cases, such as strong acids or bases, the process liquid is extremely corrosive, and corrosion-resistant plastics or glass microspheres must be used. In some cases, the process liquid may operate at elevated temperatures or pressures that would rapidly degrade some types of plastic filter media, and ceramic microspheres would be required.
In some situations, once a super-buoyant media has been selected based upon the factors described above, it may still not be optimal for the filtration of a particular process liquid. In those situations, it may be possible to modify the media so that it performs better. For example, the surface of the super-buoyant media particles may be altered by subjecting the particles to various physical or chemical treatments, including high temperature, high pressure, chemical etching, etc. These treatments are capable of modifying the surface of the media particles, for example, making it more or less hydrophobic in some cases or more or less hydrophilic in others. It is also possible to apply a polymer coating to these media particles. Such polymer coatings may determine the surface properties of the media directly, or the coatings may contain additional embedded chemicals that produce different surface properties for the media. These embedded chemicals can be selected to optimize specific aspects of the super-buoyant media, thus affecting the manner in which the filter functions.
Once the type of super-buoyant media material has been selected based upon the specific gravity of the process liquid and the other characteristics outlined above, it is essential to determine the desirable size range of the super-buoyant media particles. Ideally, the super-buoyant media particles should be as small as possible, and should be chosen based upon the size of the contaminants to be removed. Candidate media are currently available in diameters as small as 10 μm and as large as several cm.
The performance of the filter is also influenced by the thickness of the media layer. The use of thicker beds composed of larger diameter media particles generally offers good depth filtration. The use of thinner beds composed of smaller diameter media particles generally offer good surface filtration. By mixing various diameters of media particles and adjusting bed thickness, the efficiency of the filter bed can be tailored to meet a variety of filtration problems. Using smaller diameter media or thicker media beds carry a power penalty, however, as a more powerful, high pressure pump is required to force the process liquid through such a super-buoyant media bed. To resist the pressure required to move the process liquid through these beds, a strong, multi-component “sandwich” is used as a bed restraint 16 ( FIGS. 2 , 3 ). In both FIGS. 2 and 3 , a perforated metal plate 16 a provides support for the bed restraint 16 . An intermediate layer of coarse screen 16 b provides additional support as well as facilitates passage of the process liquid through the bed restraint 16 . The final layer of the “sandwich” is either a very fine mesh screen 16 c ( FIG. 2 ) for medium or coarse filter media, or a sheet of permeable metal or plastic material 16 d ( FIG. 3 ) for fine filter media.
In some situations, a thin layer of super-buoyant media is a preferable choice for filtering process liquid. In these situations, it may be necessary to insure a uniformly thin media layer by adding a ring grid 16 e ( FIG. 4 ) to the bed restraint 16 described above. As described above, this bed restraint 16 consists of a perforated metal plate 16 a , an intermediate layer of course screen 16 b and a final layer of fine screen (not shown) or a sheet of permeable metal or plastic material 16 d . The ring grid 16 e , in combination with the directed flow of the process liquid, or, occasionally, in conjunction with other mechanical rotating mechanisms, assists in maintaining a uniform, thin media layer to maximize the surface filtration provided by the media. Other grid designs (e.g., where the open area is filled with small square, rectangular, or hexagonal cells, rather than a single large central open area), may also be used to assist in maximizing the amount of surface filtration achieved.
Smaller media and thicker beds also make it more difficult to clean the filter when it becomes loaded with contaminants. However, the use of super-buoyant media provides an important and unique advantage in the process of cleaning such filter beds to remove trapped contaminants.
The most effective way to clean a super-buoyant media filter bed is to use a rigorous spray of clean process liquid while forcing the entire bed to move through the spray ( FIGS. 5A-5F ). Beginning with a normally-operating filter ( FIG. 5A ) in which the process liquid is flowing upward through the media bed 14 , cleaning is accomplished by first shutting off the flow of process fluid through the filter and then draining the process fluid from the filter housing 13 ( FIG. 5B ), thus lowering the level of the process liquid in the filter housing 13 until the entire filter bed 14 is below the backwash spray nozzle(s) 44 . Next, the drain valve (not shown) is closed and the backwash spray 5 of clean process liquid is turned on ( FIG. 5C ). As it accumulates in the housing, the level of the process liquid in the filter housing 13 rises ( FIG. 5D ). As the process liquid level in the filter housing rises, the super-buoyant media 14 (floating on the surface of the rising process liquid) also rises ( FIG. 5E ). This forces all of the media in the filter bed 14 to pass through the intense backwash spray 15 , which scours each media particle and washes off any adhering contaminants, thus insuring that each media particle is very thoroughly cleaned. The backwash spray 15 is continued until the level of the process liquid in the filter housing has risen above the backwash nozzle 44 ( FIG. 5F ). In the cleaning process, all of the contaminants captured by the media bed 14 are washed to the bottom of the filter housing 13 for removal. Although one backwash cycle is usually sufficient to clean a super-buoyant media bed, this backwash sequence may be repeated as many times as required to provide the desired level of media cleanliness. The amount of clean process liquid required for a single backwash is usually no more than 2-3 times the volume of the filter media bed.
It should also be noted that although, in the embodiments described below, the filter housing is assumed to be cylindrical in shape, other housing shapes may be selected for specific applications to increase either or both the filtration efficiency or the backwashing efficiency. Several alternative, non-cylindrical housings 13 a - 13 c are pictured in FIG. 6 . All of these alternatives provide a larger filtration area and a “necked-down” backwashing section 10 . These features enhance the total area of the super-buoyant media available for filtration, as well as providing a means of concentrating the backwash spray to increase its cleaning effectiveness.
The novel backwash mechanism described herein makes it possible to thoroughly scour and clean small diameter filter media, thus providing an unprecedented level of cleanliness in the backwashed media. As a consequence, the media does not have to be discarded nearly as frequently as previous filters which used small diameter, non-buoyant media, thus making the super-buoyant media filter design significantly more economical to operate as well as more efficient in removing contaminants.
The cleaned super-buoyant media bed retains its initial filtration characteristics, and performs in a repeatable fashion after every backwash cycle, all without requiring any sort of “ripening”. The life of the media is also very significantly extended over that experienced with non-buoyant media. In addition, because of the high efficiency of the backwash mechanism, very little particulate-laden waste process liquid is generated. Thus, this unique, novel backwash method provides a capability that has been lacking in filtration technology, one method that has not been directly addressed by any known existing patents or any known products on the market.
During normal operation, the liquid to be filtered is withdrawn from a process tank or process stream and pumped under pressure through one or more filter housings containing the aforementioned super-buoyant bed medium. The liquid being filtered is pumped into the dry housing at the bottom, elevates the filter bed by floatation to a position where further elevation is restrained and then rises through the restrained bed medium, exiting the filter housing at the top.
A valve in the exit line at the top of the housing directs the filtered liquid either back into the process tank or stream, or into a clean liquid storage tank. A small storage tank in the filtration system provides a volume of filtered liquid for use in backwashing the filtered medium to clean it by removing the particulates it strains from the process liquid. A valve in the entry line is closed when the backwash is performed to prevent backflow of contaminated liquid into the process stream. A second valve, in the exit drain line, is opened to direct the “dirty” liquid into a storage chamber where it is collected until it can be properly disposed or recycled.
In one aspect thereof, the present invention is directed to an apparatus for filtering particulate contaminants from contaminated liquid process streams, such as, by way of example, from the deionized water used during electrical discharge machining. The apparatus includes a primary pump with a liquid inlet from the process stream or process storage tank and a liquid outlet to the filter hosing a chamber. The filter chamber includes a liquid inlet from the primary pump and a liquid outlet that returns the filtered liquid to the process stream or to a clean process liquid reservoir. The filter chamber contains the filter bed which acts a a strainer to remove the particulates from the process stream.
In another aspect, the present invention is directed to a liquid filtration apparatus that includes a filter bed composed of a particulate medium that has a substantially lower specific gravity than that of the process liquid to be filtered. The particle size and nature of this bed medium are determined by the identity of the process liquid to be filtered. As the process liquid is pumped through this filter bed, the particulate contaminants are strained from the liquid by one or both of the aforementioned methods.
In a third aspect thereof, the present invention is directed to a liquid filtration apparatus that includes a backwash system that incorporates a backwash reservoir to store cleaned process liquid for backwashing, a backwash pump, a single or plurality of backwash nozzles, a backwash valve, and a backwash waste liquid/particulate collection reservoir. During the backwash cycle, stored cleaned process liquid is withdrawn from the backwash reservoir by the backwash pump and forced through the spray nozzles(s). This backwash spray, in conjunction with alternately opening and closing of the backwash valve at the bottom of the filter chamber, serves to efficiently clean the strained particulate contaminants from the bed and wash them into the waste liquid/particulate collection reservoir.
The above-mentioned and other features and objects of the invention and the manner of obtaining them will become apparent and the invention will be better understood by references to the following description of preferred embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of the difference between buoyant media particles (A) and super-buoyant media particles (B) when the particles are placed into the process liquid to be filtered.
FIG. 2 is a diagrammatic view which presents a detailed view of the filter bed retaining plates for coarse and medium filter media (mean media particle diameter greater than 100 microns [100 μm] in diameter).
FIG. 3 is a diagrammatic view which presents a detailed view of the filter bed retaining plates for fine filter media (mean media particle diameter less than 100 microns [100 μm] in diameter).
FIG. 4 is a diagrammatic view which presents a detailed view of the filter bed medium retaining plates for fine filter media (mean media particle diameter less than 100 microns [100 μm] in diameter), incorporating a ring grid to control bed thickness.
FIGS. 5A-5F are a diagrammatic view of the backwash process that illustrates the various positional relationships of the filter bed to the backwash spray nozzle during a complete filter and backwash cycle, according to the present invention.
FIG. 6 is a diagrammatic cross-sectional illustration of several different shaped filter housings which have large surface areas for retaining the super-buoyant media and narrower areas which concentrate the backwash spray to provide maximum cleaning of the media.
FIG. 7 is a diagrammatic view of the overall apparatus for filtering particulates from a process liquid according to the present invention.
FIG. 8 is a diagrammatic view of the apparatus for filtering particulates from a process liquid utilizing dual filter housings connected in a parallel flow filtration system according to the present invention.
FIG. 9 is a diagrammatic view of the apparatus for filtering particulates from a process liquid utilizing dual filter housings connected in a serial flow filtration system according to the present invention.
FIG. 10 is a diagrammatic view of the filtration apparatus incorporating an intermediate hydroxyl ion-generating reactor which functions to precipitate dissolved metal ions prior to flowing through the filter bed to enable filtering precipitates thereof from a process liquid utilizing the dual filter, serial flow filtration system illustrated in FIG. 9 .
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. The exemplification herein illustrate preferred embodiments of the invention in specific forms thereof, and such exemplifications are not to be construed as limiting the scope of the disclosure or the scope of the invention as set forth in the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Single Filter Housing Embodiment
In this embodiment ( FIG. 7 ), a central control system designated generally by the numeral 54 is used to monitor the sensors installed in the filtration system, and to turn “ON” and “OFF” all of the actuators (pumps and valves) required to operate the system. This control system may be operated either by manually actuated switches or by electronic switches activated by an embedded microprocessor. Although using a microprocessor makes the system somewhat more complex, it enables more efficient operation of the system as well as providing unattended operating capability during periods when no personnel are available to manually control the system.
During normal operation, the process liquid to be filtered is withdrawn from a reservoir 2 , connected by a conduit 3 , to a pump priming chamber 4 . Alternatively, the liquid may also be withdrawn directly from a process liquid stream. Although not absolutely required, the use of the pump priming chamber 4 helps prolong the life of the primary liquid pump 7 , by ensuring that the pump does not run “dry”. Running “dry” (i.e., run without liquid in the pump head), may damage the pump.
As the liquid is removed from the pump priming chamber 4 , through a conduit connecting the pump priming chamber 4 to the primary fluid pump 7 , a partial vacuum is created in the pump priming chamber 4 and thus in the conduit 3 connecting the reservoir 2 to the priming chamber 4 . The vacuum pulls process liquid from the reservoir and establishes a supply flow of the process liquid to the primary pump 7 . As the liquid exits the primary pump 7 , it is pumped through a conduit 8 to a normally-open valve 9 and into a connecting conduit 11 that attaches to the cylindrical filter housing 13 through the filter housing inlet 12 . It should be understood that when valves are designated herein, such valves may be manually actuated or electronically actuated, and preferably the latter.
After passing through the filter housing inlet 12 , the flowing liquid spreads out, and flows upwards through the filter housing 13 , causing the filter bed 14 , which floats on top of the liquid, to rise in the housing 13 . The filter bed 14 consists of small diameter super-buoyant particles having a specific gravity substantially lower than that of the liquid being filtered, and selected to be within a specific size range, nominally having a diameter between 0.1 micron and 25.4 mm. The size and material composition of the filter bed particles, as well as the bed volume and filtration area, are determined by the process liquid filtration requirements, including the size and nature of the particulates to be removed from the process liquid. The super-buoyant particles which compose the filter bed are typically formed from plastic, glass or ceramic materials, but in any event these particles must have a specific gravity less than one half that of the process liquid being filtered.
As the process liquid flows into the filter housing 13 , the level of the process liquid rises in the housing. The super-buoyant media bed 14 , which is floating on the rising process liquid, rises until it eventually touches the bed support 16 near the top of the filter housing. This support restrains [retains] the bed media, and prevents it both from rising any further in the housing 13 and from flowing out of the filter housing 13 along with the liquid being filtered. Although the filter bed 14 itself is prevented from rising any further in the housing 13 , the process liquid continues to rise and flows through the filter bed 14 as it is pumped into the housing 13 by the primary pump 7 .
As the liquid level rises, the liquid is filtered as it flows upwards through the filter bed 14 and then through the bed support 16 and into the top of the filter housing. The bed support 16 thus also provides a final filtration barrier to the particulates carried in the liquid. The bed support 16 is nominally formed from a multi-layer “sandwich” ( FIG. 2 ) comprising a perforated metal plate 16 a , and two or more layers of screen 16 b and 16 c . Alternatively ( FIG. 3 ), the “sandwich” may also comprise the aforementioned perforated metal plate 16 a , with a single layer of screen 16 b , and a layer of semi-permeable membrane or sintered permeable plastic or metal material 16 d.
Selection of these constituent layers depends upon the size of the filter bed particles. The fine mesh screen 16 c or membrane layer 16 d is positioned at the lower face of the bed support 16 immediately next to the filter bed media. A medium mesh screen 16 b is positioned in the center to provide structural support for the fine layer, and the perforated metal 16 a is last and provides structural stiffening for the entire support assembly. The fine material, whether screen 16 c or permeable membrane 16 d , is preferably the layer that directly contacts the filter bed media 14 . The other layers serve to provide structural support and enhance liquid flow through the bed support 16 . This multiple layer design provides the strength necessary to retain the bed media 14 under working filtration pressures that may be as high, for example, as 75 to 150 psi. Preferably, the working filtration pressures may range from approximately 20 to 150 psi. A broader range may of course be utilized under appropriate conditions related to the type of media bed, the type and size of particulates sought to be filtered thereby and the optimum velocity flow of liquid through the system.
As the process liquid flows vertically upward through the filter bed 14 , contaminant particles are retained by the filter bed through one of two different mechanisms. At the point where the process liquid flow first encounters the filter bed, surface filtration, the first mechanism, occurs. This mechanism occurs as the larger particulates are captured at the filter bed's lower surface, being unable to pass through the spaces between the particles, which make up the filter bed as the liquid flows up through the filter bed. As these larger particulates are captured at the lower surface of the filter bed, they form a crust on that surface.
Flowing along with the process liquid, smaller particulates may be captured at the bottom surface of the filter, retained by the crust formed by the accumulation of larger particulates. Thus, this crust may by itself prevent the passage of some of the smaller particulates. Some of the smaller particulates may also pass through the crust on the filter bed's lower surface, penetrate the bed, and become trapped by the second mechanism, depth filtration. In this mechanism, these smaller particulates are captured and retained in the interstitial spaces in the filter bed between the super-buoyant filter media particles. The smallest particles, depending on their size, the size of the bed particles, and the size of the openings in the bed support, may actually flow through the bed and exit the filter housing through the housing exit port 17 along with the out-flowing filtered process liquid.
After flowing through the filter bed support 16 , the process liquid enters the top portion of the filter housing above the filter bed support structure and exits through the exit port 17 . The liquid then flows through a connecting conduit 23 to a normally-open valve 24 , another connecting conduit 26 , and a flow sensor 27 . Following the flow sensor 27 , the liquid flows through an additional conduit 28 connecting to a clean process liquid reservoir 29 where the filtered liquid is stored. Also connected to this conduit 28 through an additional conduit 31 , is normally-closed valve 32 , and a final conduit 33 connected to a backwash reservoir 34 . The backwash reservoir 34 provides a means of storing filtered process liquid for use in the backwash cycle that cleans the filter bed medium.
The backwash reservoir 34 is open with respect to the atmosphere through vent 38 to prevent pressure build-up during filling as well as to prevent creation of a vacuum when liquid is removed for backwashing the filter. A liquid level sensor 36 in the backwash reservoir 34 is attached to the filter controller 54 via wire 109 . The filter controller 54 opens valve 32 via wire 110 whenever the backwash reservoir liquid level is low, thus allowing filtered process liquid exiting the filter housing 13 to enter and fill the backwash reservoir 34 . When the backwash reservoir 34 is filled, the level sensor 36 indicates to the controller 54 via wire 109 that the reservoir is full, and the controller 54 turns off valve 32 via wire 110 to stop liquid flow into the backwash reservoir 34 .
The flow sensor 27 measures the rate of flow of liquid exiting the filter bed. The signal from this sensor is transmitted to the filter controller 54 via wire 112 . As the filter accumulates more and more particulates from the liquid stream, the resistance of the bed to liquid flow increases, and the flow of process liquid through the filter lessens (unless the flow of process liquid through the primary pump 7 is increased). At a critical point (defined by the filtration requirements for the process liquid), the flow measured by flow sensor 27 is low enough that the filter must be regenerated by a backwashing process to regain its filtration capacity. This point is identified by having the control system 54 monitor the output of flow sensor 27 via wire 112 .
When a backwash operation is required, the normally-open valves 9 , 24 in the filter inflow line and in the filter outflow line, respectively, are closed by the controller via wires 103 and 111 , respectively, to prevent continued flow of the liquid through the filter. The normally-closed liquid drain valve 46 and the normally-closed atmospheric vent valve 22 are opened by the controller 54 via wires 102 and 108 , respectively. With these valves open, “dirty” liquid drains from the filter housing into the collection reservoir 48 through conduit 11 , valve 46 and conduit 47 by gravity flow under atmospheric pressure admitted into the housing through now open vent valve 22 .
As the liquid drains into the collection reservoir 48 , air enters the filter housing through valve 22 and conduit 21 , and the liquid level in the housing drops. When the liquid level reaches the bottom of the filter bed, the super-buoyant bed media 14 (which is lighter than the process liquid, and is thus still pressed against the bed support 16 as it floats on top of the process liquid begins to descend in the filter housing 13 as it floats on the descending process liquid. Filter bed 14 is allowed to fall until the top surface of the filter bed has fallen below the midpoint of the filter housing 13 , as indicated to the controller 54 by the lower fluid level sensor 18 via wire 106 . At this point, the controller 54 closes drain valve 46 via wire 102 and the backwash spray process is initiated to clean the filter bed.
In the backwash spray process, clean liquid from the backwash reservoir 34 is withdrawn through conduit 37 by the backwash pump 39 , which is turned on by the controller 54 via wire 104 , and pumped through conduit 41 , normally-closed valve 42 which is now open, and conduit 43 , and then sprayed onto the top surface of the now lowered filter bed through single or multiple backwash spray nozzle(s) 44 . The number of nozzles 44 is determined by the cross-sectional area of the filter bed and the identity and nature of the filter bed material. A single wide angle, solid cone nozzle with a wide angle of dispersion (e.g., >90 degrees) can easily backwash a filter housing of up to six to eight inches in diameter. Larger diameter housings require multiple spray nozzles for effective backwashing. When the filter bed consists of extremely fine particles, it can compress against the lower surface of the bed support 16 during filtration, thus forming a hard, compressed layer on the surface of the filter bed support. In such cases, it is usually necessary to have one or more additional spray nozzles that spray vertically upward to dislodge the compressed bed particles and wash them into the lower section of the filter housing 13 .
The backwash spray delivered by nozzle(s) 44 washes adhering contaminant particulates off each filter particle of the filter bed 14 . As this spray drains down through the remaining filter bed material, which is now in its lowermost position, carrying with it the collected contaminants, it accumulates in the bottom of the housing. As this drainage accumulates, the liquid level in the housing 13 rises, because of the continuing backwash process, and the super-buoyant media bed 14 (floating on top of the rising liquid) moves upward and past the backwash nozzle 44 which continues to spray clean liquid into the bed, thus continuously washing out the contaminant particulates, as illustrated in FIGS. 5A-5F . Because these contaminant particulates are heavier than either the liquid or the filter bed particles, the fluid spray washes them out of the bed and causes them to sink to the bottom of the filter housing 13 . Simultaneously, the super-buoyant filter bed particles, which are lighter than the process liquid, continue to float upwards on the rising liquid level in the filter housing 13 .
The backwash spray is continued until the entire filter bed 14 has risen above the nozzle 44 , thus ensuring that all of the filter bed particles are cleansed by the spray of clean liquid emitted by the nozzle 44 . Level sensor 19 indicates to the controller 54 via wire 107 that the level of liquid in the housing 13 has risen to the appropriate level, and thus indicates that the entire filter bed has been washed in this manner.
When the filter controller 54 receives information from the level sensor 19 that the liquid level is correct, the controller closes valve 42 via wire 105 , opens drain valve 46 via wire 102 , and thus causes the particulate-laden liquid to once more drain into the collection reservoir 48 . This backwash sequence can then be repeated as necessary to ensure the highest level of cleanliness in the filter bed. Once backwashed, the clean filter medium, once again located in the lower end of the filter chamber, is again ready to filter particulates from the process liquid stream.
To accelerate the removal of contaminated liquid from the bottom of the filter housing, it is possible to add a suction pump or siphon tube (not shown) to the system. Such additions easily make it possible to remove the contaminated process liquid from the housing 13 in thirty seconds or less. After backwashing, the filtration process is again initiated by the controller 54 closing valves 46 and 22 via wires 102 and 108 opening the inlet valve 9 via wire 103 and the outlet valve 24 via wire 111 , and pumping liquid from reservoir fluid pump 7 by actuating pump 7 via wire 101 . As process liquid again enters the housing, the filter bed 14 again rises in the filter housing until it encounters the bed support 16 . The filtration process then begins once again as the process liquid begins to flow upwards through the stabilized filter bed and the particulate contaminants begin to be captured by one of the two aforementioned filtration mechanisms.
Parallel Filter Housing Embodiment
Depending on the specific filtration requirements of the process, modifications of the basic single housing filtration system illustrated in FIG. 7 and described above may be required for optimal filtration. In some processes, for example, it is undesirable or virtually impossible to temporarily discontinue operation of the filtration process to clean a filter by backwashing. Thus, in this second embodiment of this filtration system design, as illustrated in FIG. 8 , two filter housings (containing the same type of bed material) are connected in parallel with one another, so that the filtration system can continue to function without interruption while one of the two filters is being cleaned by backwashing. In this embodiment, the two filters may be the same size or the primary filter may be larger than the secondary filter. In the former case, the two filters may share filtration effort equally, while in the latter case, the secondary filter serves only as a temporary filter to maintain filtration capability during the brief time required to backwash the primary filter.
In this embodiment, a central control system 54 with an embedded microprocessor is used to monitor the sensors installed in the filtration system, and to turn “ON” and “OFF” all of the actuators (pumps and valves) required to operate the system. Although this control system may also be operated manually, due to its increased complexity, the system is much more effectively controlled by an embedded microprocessor. As above, the embedded microprocessor enables more efficient operation of the system as well as providing unattended operating capability for operation during periods when no personnel are available to manually control the system.
In this second embodiment, the flow of the process liquid through the first or primary filter housing 13 follows the sequence described above for the system of FIG. 7 . In the interest of brevity in this description, the operational sequence applicable to the embodiment of FIG. 7 is included herein by reference rather than repeating the sequence.
When backwash of the primary filter 13 is required in this second embodiment, the normally-open valves 9 and 24 in the primary filter inflow line 11 and in the filter outflow line 23 , respectively, are closed by the controller 54 via wires 103 and 111 , respectively, to prevent continued flow of the liquid through the filter 13 . At the same time, the controller 54 opens normally-closed valves 57 and 73 via wires 115 and 119 , respectively, to initiate the flow of process liquid through the secondary filter housing 62 . The liquid is pumped by the primary pump 7 through conduits 8 and 56 to a now open (but normally-closed) valve 57 and into a connecting conduit 59 which attaches to the secondary filter housing 62 through the filter housing inlet 61 .
After passing through the inlet 61 of the secondary filter housing 62 , the flowing liquid spreads out and flows upward through the filter housing 62 , causing the filter bed 63 , which floats on top of the rising liquid, to rise in the housing 62 . The secondary filter bed 63 is composed of the same particles as the primary filter bed 14 . The particles in the secondary filter bed have the same specific size range, density and composition as the particles in the primary filter in order to meet the needs of the filtration process.
Alternatively, the primary filter 13 may be larger than the secondary filter 62 . In the former case, the two filters may share filtration effort equally, while in the latter case, the secondary filter 62 serves only as a temporary filter to maintain filtration capability during the brief time required to backwash the primary filter 13 .
As the process liquid flows into the secondary filter housing 62 , the level of the process liquid rises in the housing, and the filter bed 63 , floating on the rising process liquid, reaches the bed support 64 near the top of the filter housing 62 . As described above in relation to the embodiment of FIG. 7 , this support retains the super-buoyant filter bed media, and also provides a final filtration barrier to the particulates carried in the liquid. The filter bed support 64 is nominally formed from the same kind of multi-layer “sandwich” ( FIGS. 2 , 3 ) described above.
As the process liquid flows vertically upward through the filter bed 63 , contaminant particles are retained by the filter bed 63 through surface filtration and depth filtration mechanisms. After flowing through the bed support 64 , the rising liquid enters the top portion of the filter housing and exits through the exit port 66 . The liquid then flows through a connecting conduit 72 to a normally-closed but now open valve 73 , another connecting conduit 26 , and the flow sensor 27 . From the flow sensor, the liquid flows through an additional conduit 28 connected to the clean process liquid reservoir 29 . Also connected to this conduit 28 through an additional conduit 31 , normally closed valve 32 , and final conduit 33 , is the backwash reservoir 34 . As the liquid level in the backwash reservoir 34 descends, it is measured by level sensor 36 . When the level reaches a predetermined minimum value, the sensor signals the controller 54 through wire 109 to open valve 32 via wire 10 . Additional clean liquid is then added to the backwash reservoir 34 through conduit 31 , valve 32 and conduit 33 . When the liquid level In the backwash reservoir 34 is returned to its normal level, the controller 54 closes valve 32 via wire 110 to stop the flow of liquid into the backwash reservoir 34 .
Once the flow of the process liquid has been directed into the secondary filter housing for filtration, the backwash cycle for the primary filter housing 13 can be initiated. The normally-closed liquid drain valve 46 and the normally-closed atmospheric vent valve 22 are opened by the controller 54 via wires 102 and 108 , respectively. With these valves open, dirty liquid drains from the primary filter housing 13 into the collection reservoir 48 through conduit 11 , valve 46 and conduit 47 .
As the liquid from the primary filter housing 13 drains into the collector reservoir 48 during the backwash cycle, air enters the filter housing through valve 22 and conduit 21 , and the liquid level in the housing drops. When the liquid level reaches the bottom of the filter bed 14 , the super-buoyant filter bed material (which is lighter than the process liquid, and thus is still pressed against the filter support 16 as it floats on top of the process liquid begins to descend in the filter housing 13 as it floats on the top of the receding liquid. The liquid level is allowed to descend until the top of the filter bed has descended below the midpoint of the filter housing 13 . At this point, level sensor 18 signals the controller 54 via wire 106 that the liquid level has dropped to the appropriate level, and the controller closes the drain valve 46 via wire 102 and the backwash spray process is initiated to clean the primary filter bed as previously explained.
After backwashing of the primary filter bed 14 has been completed, the controller re-initiates the filtration process in the primary filter housing 13 by closing valves 46 , 22 and 57 , via wires 102 , 108 and 115 , respectively, and by opening the inlet valve 9 and exit valve 24 via wires 103 and 111 , and pumping liquid from the reservoir 2 via the primary liquid pump 7 . As process liquid again enters the housing 13 , the filter bed 14 rises in the housing and stabilizes when it encounters the bed support structure 16 . The filtration process then begins once again as the process liquid begins to flow upward through the stabilized filter bed.
Once the primary filter has been brought back into filtering operation, the secondary filter 63 contained in the secondary filter housing 62 can be cleaned in the same manner by the backwashing process used for the primary filter. In the case of the secondary filter, the process begins when the controller 54 opens the normally-closed liquid drain valve 58 and the normally-closed atmospheric vent valve 71 via wires 114 and 118 . With these valves open, dirty liquid drains from filter housing 62 into the collection reservoir 48 through conduit 59 , valve 58 and conduit 47 .
As the liquid from the secondary filter housing 62 drains into the collection reservoir 48 , air enters the filter housing 62 through valve 71 and conduit, 69 , and the liquid level in the housing 62 drops. When the liquid level reaches the bottom of the filter bed 63 , the bed material (which is lighter than the process liquid, and thus still pressed against the bed support 64 as it floats on top of the process liquid) begins to descend in the filter housing 62 as it floats on the top of the receding liquid. The liquid level is allowed to descend until the top of the filter bed has fallen below the midpoint of the filter housing 62 , as indicated to the controller 54 by the lower liquid level sensor 67 via wire 116 . At this point, the controller closes drain valve 58 via wire 114 and the backwash spray process is initiated to clean the secondary filter bed.
To effectively backwash the secondary filter 63 , clean liquid from the backwash reservoir 34 is again withdrawn through conduit 37 by the backwash pump 39 and pumped through the supply conduit 41 , the normally-closed valve 76 which the controller has opened via wire 113 , and conduit 77 , and is then sprayed onto the filter bed 63 through single or multiple backwash spray nozzle(s) 78 . As explained with respect to the FIG. 7 embodiment, the number of nozzles 78 is determined by the cross-sectional area of the filter bed and the identity and nature of the filter bed material. The same backwashing procedure as explained with respect to the FIG. 7 embodiment continues until the entire filter bed has risen above the nozzle 78 , allowing all of the bed particles to be cleansed by the spray of clean liquid emitted by the nozzle 78 . Level sensor 68 then indicates to the controller via wire 117 when the level of liquid in the housing 62 has risen to the appropriate point, thus indicating that the entire secondary filter bed has been washed of all contaminants and particulate matter. When the controller 54 receives information from level sensor 68 via wire 117 that the liquid level is appropriate, the controller 54 opens the drain valve 58 via wire 114 , and the particulate-laden liquid once more drains into the collection reservoir 48 . This backwash sequence can then be repeated if necessary to ensure the highest level of cleanliness in the filter bed. The backwashed, clean filter medium 63 is then once again ready to filter particulates from the process liquid stream. To accelerate the removal of contaminated liquid from the bottom of the filter housing, it is possible to add a suction pump or siphon tube (neither shown) to the system. Such additions make it possible to remove the contaminated process liquid from the housing 62 in less than one minute.
Series Filter Housing Embodiment
In this embodiment, two filter housings are connected in series with one another as illustrated in FIG. 9 to provide a filtration capability which is enhanced over that provided by a single filter. In this embodiment, the super-buoyant filter bed material 14 in the first housing 13 is selected to filter out one or more specific components while the super-buoyant bed material 63 in the second housing 62 is selected to filter out one or more components different from those removed by the first filter. For example, in one specific embodiment, the bed material 14 in the first housing 13 is composed of coarser, larger diameter particles, while the filter bed material 63 in the second housing 62 is composed of finer, smaller diameter particles. This embodiment allows the first filter bed 14 to serve as a “coarse” filter for removing larger contaminant particles, and the second filter bed 63 to serve as a “fine” filter for removing smaller contaminant, particles which remain after the process liquid passes through the first bed 14 . By arranging these two filters in series as shown, it is possible to optimize each filter bed for the removal of specific contaminants and thus to maximize the total amount of contaminant removed by the filtration system.
In operation, the process liquid to be filtered is withdrawn from the storage reservoir 2 through conduit 3 to the priming chamber 4 , by the vacuum created by the pumping action of the primary pump 7 . Alternatively, the liquid may also be withdrawn directly from a process liquid stream. The liquid then passes from priming chamber 4 through conduit 6 to the primary liquid pump 7 , by which it is pumped through conduit 8 , to the normally-open inlet valve 9 , and into the connecting conduit 11 . Through the connecting conduit 11 in turn, the liquid is pumped into the first filter housing 13 through the filter housing inlet 12 as previously described in relation to the FIG. 7 embodiment.
In embodiment of FIG. 9 , as in the previous embodiments, after passing through the inlet 12 , the flowing liquid spreads out and flows upward through the filter housing 13 , causing the filter bed 14 , which floats on top of the rising liquid to rise in the housing 13 . The first filter bed 14 is composed of super-buoyant particles having a specific gravity less than one half that of the liquid being filtered, and selected to be within a specific size range, e.g., between 0.5 and 1.0 mm for a “coarse” filter. As with the other embodiments, the size and composition of the filter bed particles, as well as the bed volume and filtration area, are determined by the specific process liquid filtration requirements, including the size and nature of the particulates to be removed from the process liquid. The particles which compose the filter bed 14 are typically formed from plastic, glass or ceramic materials, but in any event these particles must have a specific gravity less than one half that of the specific gravity of the liquid being filtered.
As previously described with respect to the other embodiments, the level of the process liquid rises in the housing 13 , the filter bed 14 , which is floating on the rising process liquid, rises until it touches the bed support 16 adjacent the top of the filter housing. This support 16 retains the bed media 14 , and prevents it both from rising any further and from flowing out of the filter housing along with the liquid being filtered. The bed support 16 also provides a final filtration barrier to the particulates carried in the liquid. As described above, the bed support 16 is nominally formed from a multi-layer sandwich ( FIG. 2 ), consisting of a perforated metal plate 16 a , and two or more layers of screen 16 b and 16 c or alternatively ( FIG. 3 ), a layer of screen 16 b and a layer of semi-permeable membrane or sintered permeable plastic or metal material 16 d.
Selection of these constituent layers depends upon the size of the filter bed particles. The fine mesh screen 16 c or membrane layer 16 d is positioned adjacent the lower face of the bed support 16 immediately next to the filter bed media, a medium mesh screen 16 b is positioned in the center to provide structural support for the fine layer, and the perforated metal plate 16 a is last and provides structural stiffening. The fine material, whether screen 16 c or permeable membrane 16 d , is always the layer which directly contacts the top of the filter bed media 14 . The other layers serve to provide structural support and enhance liquid flow through the bed support 16 . This multiple layer design provides the strength necessary to retain the bed media under working filtration pressures that may be as high as 75-150 psi, as previously described. As the process liquid flows vertically upward through the filter bed 14 , contaminant particles are retained by the filter bed through two different mechanisms previously discussed. At the point where the process liquid flow first encounters the super-buoyant media filter bed, surface filtration, the first mechanism, occurs. This mechanism occurs as the larger particulates are captured at the filter bed's lower surface, being unable to pass through the spaces between the particles that make up the filter bed as the liquid flows up through the bed. As these larger particulates are captured at the lower surface of the filter bed, they form a crust on that surface.
Flowing along with the process liquid, smaller particulates may be captured at the bottom surface of the filter, retained by the crust formed by the accumulation of larger particulates. Thus, this crust may by itself prevent the passage of some of the smaller particulates. Alternatively, the smaller particulates may pass through the crust on the filter bed's lower surface, penetrate the bed, and become trapped by the second mechanism, namely, depth filtration, which captures and retains the smaller particles in the interstitial spaces between the filter media particles forming the bed. The smallest particulates will pass through the crust on the first filter bed's lower surface, the bed 14 itself and the bed restraint structure 16 . These particulates will then flow with the liquid out of the filter through the filter housing outlet 17 , conduit 82 , the normally-open inlet valve 83 for the second filter bed, conduit 84 , and finally into the second filter housing 62 through the housing inlet 61 .
After passing through the inlet 61 , the flowing liquid spreads out, and flows vertically upward through the filter housing 62 , causing the filter bed 63 , which floats on top of the rising fluid, to rise in the housing 62 . The second filter bed 63 is composed of smaller diameter particles than the first filter bed 14 (e.g., 0.05 to 0.1 mm). The second filter bed particles are selected to be within the specific size range and composition to meet the specific needs of the filtration process as well as having a specific gravity lower than that of the liquid being filtered.
As the process liquid flows into the filter housing 62 , the level of the process liquid rises in the housing, and the bed 63 , floating on the rising process liquid, reaches the bed support 64 adjacent the top of the filter housing. As described above, this support retains the bed media 63 , and also provides a final filtration barrier to the particulates carried in the liquid. The bed support is nominally formed from the same kind of multi-layer sandwich 16 previously discussed and illustrated in FIGS. 2 and 3 .
As the process liquid flows vertically upward through the filter bed 63 , the smallest contaminant particles are retained by the second filter bed 63 through both surface filtration and depth filtration mechanisms. After flowing through the bed support 64 , the liquid enters the top of the filter housing and exits through the exit port 66 . The liquid then flows through a connecting conduit 86 to a normally-open valve 87 , another connecting conduit 88 , and a flow sensor 27 . From the flow sensor 27 , the liquid flows through an additional conduit 28 that connects to a clean process liquid reservoir 29 . Also connected to this conduit 28 through an additional conduit 31 , normally-closed valve 32 , and final conduit 33 , is the backwash reservoir 34 . As the liquid level in the backwash reservoir 34 recedes and is sensed by level sensor 36 , the sensor signals the controller 54 via wire 109 and the controller adds clean liquid to the reservoir 34 by opening normally-closed valve 32 via wire 110 . When the liquid level in the backwash reservoir 34 is sufficient, the level sensor 36 signals the controller 54 via wire 109 and the controller closes valve 32 via wire 110 to stop the flow of liquid into the reservoir 34 .
The backwash process in this embodiment is to clean each bed individually, routing the dirty liquid from both filters into the collection tank 48 . When backwash operation is required in this embodiment, the controller 54 closes the normally-open valves 9 , 83 in the first filter inflow line 11 , in the second filter inflow line 82 , and valve 87 , in the filter outflow line 86 via wires 103 , 123 and 127 , respectively, to prevent continued flow of the liquid through the filters. The controller 54 opens the normally-closed liquid drain valve 46 and the normally-closed atmosphere vent valves 22 via wires 102 and 111 . With these valves 46 , 22 open, dirty liquid drains from the first filter housing 13 into the collection reservoir 48 through conduit 11 , valve 46 and conduit 47 . As the liquid from the first filter housing 13 drains into the collection reservoir 48 , air enters the filter housing through valve 22 and conduit 21 , and the liquid level in the housing drops. When the liquid level reaches the bottom of the bed, the bed material 14 (which has a specific gravity less than one half that of the process fluid, and thus is still pressed against the retaining screen 16 as it floats on top of the process liquid) begins to descend in the filter housing 13 as it floats on the top of the receding liquid. The liquid level is allowed to recede until the top of the filter bed has descended below the midpoint of the filter housing, which fact is indicated to the controller 54 by the lower liquid level sensor 18 via wire 106 . At this point, the controller 54 closes the drain valve 46 via wire 102 and the backwash process is initiated to clean the filter bed 14 .
In the backwash process for this embodiment of the invention, clean liquid from the backwash reservoir 34 is withdrawn through conduit 37 by the backwash pump 39 and pumped through the supply conduit 41 , the normally-closed Valve 42 which the controller 54 has now opened via wire 105 , and conduit 43 and then sprayed onto the bed through single or multiple backwash spray nozzle(s) 44 . The number of nozzles 44 is determined by the cross-sectional area of the filter bed and the identity of the bed material. A single wide angle solid cone nozzle with a wide angle of dispersion (e.g. 90 degrees) can easily backwash a filter bed contained in a housing of up to six to eight inches in diameter. Larger diameter housings and smaller particle filter beds require multiple liquid spray nozzles for effective backwashing. When the bed consists of extremely small particles, which may compress during filtration, it may be necessary to have one or more additional spray nozzles spray vertically upwardly to help dislodge the compressed bed particles and wash them into the lower section of the filter housing 13 .
As clean liquid is sprayed downward from the nozzle 44 , it washes adhering contaminant particulates off each particle of the filter bed 14 . As this sprayed liquid drains down through the remaining bed material, carrying with it the collected contaminants and any additional contaminants that become entrained in the liquid along the way, it accumulates in the bottom of the housing. As it accumulates, the liquid level in the housing rises, and the super-buoyant media bed (floating on top of the liquid) rises in the housing. As the bed 14 rises, the bed particles move upward in the housing, moving the bed particles past the backwash nozzle 44 , which is now essentially embedded in the filter bed 14 , and which continues to spray clean liquid into the bed, thus continuously washing out of the filter bed the contaminant particulates.
Because these contaminant particulates are heavier than either the liquid or the bed particles, the liquid spray washes them out of the bed and causes them to sink to the bottom of the filter housing. Simultaneously, the filter bed particles, which are lighter than the process liquid, continue to float upwards on the rising liquid level in the filter housing. The backwash spray is continued until the entire bed has risen above the nozzle, allowing all of the bed particles to be cleansed by the spray of clean liquid emitted by the nozzle 44 . Level sensor 19 indicates to the controller 54 through wire 107 that the level of liquid in the housing 13 has risen to the highest appropriate level, thus indicating that the entire bed has been washed in this fashion and that the filter bed now is positioned in the top portion of the filter housing above the body of contaminated liquid.
When the filter controller receives the signal from level sensor 19 that the level is appropriate, the controller 54 opens drain valve 46 via wire 102 , and the particulate-laden contaminated liquid drains into the collection reservoir 48 . Such draining may be effected by gravity induced flow, or a suction pump or siphon tube may be utilized to totally drain the contaminated liquid in less than one minute, causing the filter bed to descend in the housing as the contaminated liquid recedes.
This backwash sequence can then be repeated as necessary to ensure the highest level of cleanliness in the filter bed. After the backwash process is completed, the controller 54 closes normally-closed valves 22 and 46 via wires 111 and 102 . Once backwashed, the clean filter medium is then again ready to filter particulates from the process liquid stream.
After the first filter bed 14 is backwashed, the second filter bed 63 backwash operation is performed. To backwash the second filter bed 63 , the controller 54 keeps the normally-open valves in the filter inflow line 83 and in the filter outflow line 87 closed to prevent continued flow of the liquid through the filter. The controller 54 then opens the normally-closed liquid drain valve 91 and the normally-closed atmospheric vent valve 71 via wires 122 and 126 . With these valves open, dirty liquid drains from filter housing 62 into the collection reservoir 48 through conduit 84 , valve 91 and conduit 47 . As the liquid from the secondary filter housing 62 drains into the collection reservoir 48 , air enters the filter housing through valve 71 and conduit 69 , and the liquid level in the housing drops.
When the liquid level reaches the bottom of the bed, the bed material begins to descend in the filter housing 62 as it floats on the top of the receding liquid. The liquid level is allowed to fall until the top of the filter bed has descended below the midpoint of the filter housing, as indicated to the controller 54 by the lower liquid level sensor 67 via wire 124 . At this point, the controller closes drain valve 91 via wire 122 and the backwash process is initiated to clean the filter bed.
In the backwash process, clean liquid from the backwash reservoir 34 is withdrawn through conduit 37 by the backwash pump 39 and pumped through the supply conduit 41 , the normally-closed valve 76 which the controller has now opened via wire 121 , and conduit 93 and then sprayed onto the bed through single or multiple backwash spray nozzle(s) 78 . The number of nozzles 78 is determined by the cross-sectional area of the filter bed and the identity of the bed material. When the bed consists of extremely small particles, which may compress during filtration, it may be necessary to have one or more additional spray nozzles spray vertically upward to help dislodge the compressed bed particles and wash them into the lower section of the filter housing 62 .
As clean liquid is sprayed downward from the nozzle 78 , it washes adhering contaminant particulates off each particle of the filter bed 63 . As this sprayed liquid drains down through the remaining bed material, carrying with it the collected contaminants, it accumulates in the bottom of the housing. As it accumulates, the liquid level in the housing rises, and the super-buoyant media bed (floating on top of the liquid) rises in the housing. As the bed rises, the bed particles move upward in the housing, moving the bed particles past the backwash nozzle 78 which continues to spray clean liquid into the bed, thus continuously washing out the contaminant particulates and causing them to sink to the bottom of the filter housing 62 . Simultaneously, the filter bed particles, which are lighter than the process liquid, continue to float upward on the rising liquid level in the filter housing.
The backwash spray is continued until the entire bed has risen above the nozzle, allowing all of the bed particles to be cleansed by the spray of clean liquid emitted by the nozzle 78 . Level sensor 68 indicates to the controller 54 through wire 125 that the level of liquid in the housing 62 has risen to the appropriate level, thus indicating that the entire bed has been washed in this fashion and now lies above the contaminated body of liquid. When the filter controller 54 receives information from the level sensor 68 that the level of the contaminated liquid is appropriate, it opens drain valve 91 via wire 122 , and all the particulate-laden liquid once more drains into the collection reservoir 48 . This backwash sequence can then be repeated as necessary to ensure the highest level of cleanliness in the filter bed. The backwashed, clean filter medium is then again ready to filter particulates from the process liquid stream.
After backwashing of both filter beds 14 and 63 is completed, the filtration process is again initiated when the controller 54 closes valves 91 and 71 via wires 122 and 126 , opens the inlet valves 9 and 83 and exit valve 87 via wires 103 , 123 and 127 , respectively, and pumps liquid from the reservoir 2 via the primary fluid pump 7 . As process liquid again enters the housings, the filter beds 14 , 63 rise in the housings and stabilize when they encounter their respective filter bed restraint structures 16 , 64 . The filtration process then begins once again as the process liquid begins to flow upward through the stabilized filter beds.
Filtration of Dissolved Metals
In this embodiment, illustrated diagrammatically in FIG. 10 , two filter housings 13 and 62 are arranged in series as described above with respect to FIG. 9 , and function by a unique method of chemical precipitation of dissolved, ionized metals in the aqueous solutions, followed by filtering of and removal of the precipitated particulates from the process liquid with a particulate filter as previously discussed. This is in contrast to dissolved metals conventionally precipitated in a liquid containing them by the direct addition of basic solutions (e.g., lime, sodium hydroxide, potassium hydroxide), which provide the required hydroxyl ions for initiation of the precipitation reaction. This addition of basic solutions is usually accomplished conventionally by using a metering pump to inject precise amounts of the basic solution into the process liquid stream as it enters a reactor, which serves to ensure sufficient mixing for the metal hydroxides to form and precipitate. These precipitates are subsequently captured by a particulate filtration system.
The advantage of the metals removal system described herein, in contrast to the conventional method described above, is that no basic solutions need be added to cause the precipitation. Instead, the hydroxyl ions are generated directly in the process liquid by pumping the liquid through an ultraviolet radiation reactor. This ultraviolet radiation forms hydroxyl ions in the metal-containing aqueous solution. These hydroxyl ions chemically combine with the ionized metals and cause them to precipitate and form particulates. These particulates are then removed from the aqueous solution by the filter bed filtration embodiments described herein.
A diagram of a system to effect this type of precipitation is presented in FIG. 10 . The diagram presented in this figure illustrates a pair of filter beds connected in series as described above and illustrated in FIG. 9 . In FIG. 10 , however, an ultraviolet reactor 191 has been added to the system to process aqueous solution exiting from the first (coarse) filter housing 13 . Except for the addition of the ultraviolet reactor 191 , the structure and operation of the system of FIG. 10 is in all respects similar to the structure and operation of the system illustrated in FIG. 9 and described hereinabove. Accordingly, in the interest of brevity in this description, the operation of the system of FIG. 10 will not be described in detail and the description of the system illustrated in FIG. 9 is incorporated herein by reference. In this embodiment, suffice to say that both the smallest particulate and the dissolved metals will flow with the liquid out of the filter housing 13 through the filter housing outlet 17 and will proceed through conduit 82 .
The aqueous process liquid then flows through an ultraviolet (UV) exposure reactor 191 , where it is exposed to a high flux of UV radiation. The UV radiation induces the formation of hydroxyl ions in the liquid, which subsequently combine with the ionized metals in the solution to form insoluble precipitate particles. The liquid then flows out of the UV exposure reactor 191 , through the normally-open inlet valve 83 for the second filter bed, conduit 84 , and into the second filter housing 62 through the housing inlet 61 . The process liquid, now bearing the insoluble precipitated particles passes upward through the filter bed 63 in the second filter housing 62 as previously described.
While the invention has been described as having specific embodiments, it will be understood that it is capable of further modification. The disclosure herein is therefore intended to cover any variations, uses, or adaptations of the Invention as come within the scope of the appended claims. Accordingly, having described the invention, what is believed to be new and novel and sought to be protected by letters patent is as follows. | Presented is a liquid filtering apparatus and method that overcomes the disadvantages encountered with prior bed filtration systems by providing a filtering apparatus that incorporates a super-buoyant filter medium having a specific gravity very substantially lower than that of the process liquid being filtered. This feature enables a majority of the medium to float on top of the process liquid. Due to the significant differences in specific gravity between the media and the process liquid, super-buoyant media produce a highly advantageous means of naturally, gravimetrically separating both clean and contaminated filter media and process liquid into separate “phases”. Under normal filtering operation, the filter media is contained within a filter housing by a bed support near the top of the filter housing, and particulate material is filtered from a process liquid that passes through the housing. To regenerate the filter media, the housing is drained and a nozzle creates a backwash spray that washes the particulate material from the filter media. During the backwash process, the filter media rises past the nozzle as the level of the backwash liquid in the housing rises, so that the entire filter media is regenerated. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a 371 of PCT/EP00/05216, filed on Jun. 7, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method as well as to a system Particularly for the operation of high-speed plants for slabs and, in this connection, particularly in combination with rolling mills, it is important to be able to operate the continuous casting plant at a high and controlled speed in a safe way.
This necessity of safety for casting particularly at high casting speeds up to 10 m/min. makes it necessary to carry out control of numerous processing data, which are intermeshed in a complex fashion with one another, by means of automation.
This automation must be reduced with respect to its external operation language to a simple functional language which is easily manageable by the operating personnel.
Moreover, the degree of automation, which in regard to its operating language knows only the selection of casting speed and the control all of the narrow side heat flow at the operator (NO) or drive (ND) side, should provide the possibility of operation by autopilot when certain conditions such as
a controlled steel temperature in the distributor
a good oxidic purity of the steel
a calm meniscus as well as
a constant and uniform heat flow of the faces are present.
2. Description of Related Art
The prior art discloses the measuring of the heat flows of all four copper plates of a slab casting mold (DE 4117073) but in this patent document no prior art as a function of the casting speed is disclosed. For example, a speed increase has a minimal effect on the casting mold stress, expressed as MW/m 2 , and a great effect on the strand shell stress expressed as MWh/m 2 .
FIG. 1 shows this correlation and illustrates that at high casting speeds, when using casting powder and a certain castings speed of, for example, >4.5 m/min., the casting mold stress remains almost constant and the strand shell stress is greatly reduced. The reason for this is that at high casting speed a constant slag film and thus a constant heat transfer occurs but a residence time of the strand shell within the casting mold decreases proportionally to the casting speed increase. This illustration makes clear that with increasing casting speed the casting mold stress no longer increases and the casting shell stress decreases so that the risk of fracture formation is reduced but also the casting shell becomes thinner and hotter, for example, at the end of the casting mold.
In FIG. 2, the interrelationships are represented between
casting slag film,
the strand shell temperature, for example, at the exit of the
casting mold, strand shell thickness, and shrinkage,
casting mold and strand shell stresses or shrinkage,
maximum casting mold skin temperature at the meniscus and thus of the casting mold service life in relation to the recrystallization temperature which results in softening of the cold-rolled copper.
U.S. Pat. No. 3,478,808 discloses a method for controlling the parameters of a continuous casting plant for casting steel. Nominal values of parameters, which have been taken from a previous casting process, are stored; actual values of the parameters are recorded, an adjustment of the actual and nominal values is carried out, and a control of the parameters is performed. The disclosed parameters are inter alia the flow speed, the heat removal rate within the casting mold and the removal speed.
SUMMARY OF THE INVENTION
Based on this, it is an object of the invention to further develop a method and a system for performing the method for a controlled operation of a continuous casting plant for casting slab, in particular, thin slab, with very high casting speeds.
An automation of the continuous casting process based on an “online” data acquisition is made possible which enables in addition to
a semi-automation, i.e., the control of the narrow side conicity and the casting speed, also
a full automation in the sense of an autopilot operation with consideration and as a function of the steel temperature in the distributor and with the prerequisite of a controlled
purity,
meniscus, and
face heat flow.
This object is solved by the features of the method claim 1 and the device claim with their dependent claims for configuring the invention.
BRIEF DESCRIPTION OF THE DRAWING
The Figures are provided as examples for illustrating the invention and are described in the following. It is shown in:
FIG. 1 the casting mold and strand shell stress as a function of the casting speed
FIG. 2 the interrelationships between the casting speed and
the slag film thickness
the strand shell temperature, shrinkage as well as trend shell thickness at the exit of the casting mold,
casting mold and strand shell stress as well as shrinkage,
temperature stress of the copper plates at the meniscus as well as service life of the copper plates relative to the recrystallization temperature of the cold-rolled copper plate.
The FIGS. 1 and 2 have already been described in detail as prior art and are provided for a better understanding of the following description which is not to be viewed as being obvious to a person skilled in the art and thus includes an inventive step.
FIG. 3 . illustrates
a) a slab casting mold ( 1 ) with ( 1 . 1 ) and without pouring hopper and in regard to its conicity and adjustable narrow sides ( 1 . 2 ) as well as submerged exit nozzle (SEN)( 1 . 5 ) and casting powder
b) the casting mold stress, expressed as MW/m 2 for faces (WL) and (WF) as well as for the narrow sides (ND) and (NO) over the casting time and
c) the relationship of the heat flows from the faces to the narrow sides, expressed as NO/WL, NO/WF and ND/WL, NO/WF, which describe the course of the heat flows more simply and facilitate their correction over the conicity adjustment during casting.
FIG. 4 shows the casting situations A, B, C with the aid of
a) the heat flows, expressed as MW/m 2 or
b) the relationship of the heat flows ND/WF, ND/WL and NO/WF, NO/WL, which experience a correction by adjustment of the narrow sides in their conicity from the position 0 to the position 1 .
FIG. 5 illustrates the temperature course of molten masses in the distributor over a casting time of one hour.
FIG. 6 illustrates the casting window defined by the steel temperature in the distributor and the casting speed with exemplary temperature courses of different molten masses.
FIG. 7 illustrates the data acquisition and the control circuit in the area of the continuous casting plant with the input of limits for the control and regulation of the narrow side conicities and the maximum casting speed as a function of the steel temperature in the distributor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 is comprised of the partial Figures a), b), and c). FIG. 3 a ) illustrates schematically a slab or bloom casting mold ( 1 ), comprised of two individual narrow sides ( 1 . 2 ), which are provided at the operating side ( 1 . 2 . 1 ) (NO) and drive side ( 1 . 2 . 2 ) (ND) with adjusting. cylinders ( 1 . 2 . 3 ), and two faces ( 1 . 3 ), respectively, the backside ( 1 . 3 . 1 ) (WF), and the loose side ( 1 . 3 . 2 ) (WL).
The casting mold ( 1 ) furthermore can advantageously be provided with a pouring hopper ( 1 . 1 ). The liquid steel ( 1 . 4 ) is introduced through the submerged exit nozzle ( 1 . 5 ) below the bath level ( 1 . 7 . 2 ) in the casting mold when using a casting powder ( 1 . 6 ) with formation of casting slag ( 1 . 6 . 1 ) and a casting slag film between the casting mold ( 1 ) and the strand shell ( 1 . 7 . 1 ), which is provided for lubrication and heat flow control.
FIGS. 3 b ) and c ) show the specific course of heat flow in MW/m 2 of the faces WF, WL ( 1 . 3 . 2 ) and the narrow sides NO ( 1 . 2 . 1 ), NO ( 1 . 2 . 2 ) in the normal, uneventful casting process, wherein the casting time from the beginning to the time tx at which the steel is within temperature equilibrium. The narrow side flows must have over the conicity adjustment of the narrow sides a ratio to the faces of <1 which must be maintained constant over the casting time.
Different slag films formed across the strand circumference, especially between the faces and the narrow sides, different casting speeds, different steel temperatures, non-uniform flow conditions in the left and the right half of the casting mold, a deflection of the slab from the strand center axis in the casting direction can cause deviations in regard to the specific heat dissipation.
These deviations are illustrated in FIG. 4 with the aid of three typical situations A, B and C (FIG. 4) by means of the specific heat flows, expressed as MW/m 2 in FIG. 4 b ) and as a heat flow ratio narrow side/faces (N/W) in FIG. 4 c ).
In the situation A, the heat flow of the narrow side deviates at the drive side (ND) ( 1 . 2 . 2 ) from that of the narrow side at the thickness side (NO) ( 1 . 2 . 1 ) by a heat flow that is too small. With a greater adjustment of the conicity at the narrow side from position 0 to position 1 , the heat flow is adjusted to that of the narrow side (NO).
In the situation B, the heat flows of both narrow sides are too great in comparison to the faces. By reducing the conicity adjustment of both narrow sides from the position 0 to the position 1 , the heat flows are brought into the correct ratio relative to the faces.
In the situation C, the heat flows of the narrow sides are too small and can be adjusted to the correct value relative to the faces by a simultaneous enlargement of the narrow side conicity from the position 0 to the position 1 .
FIG. 5 represents the temperature course of numerous molten masses over a time period of approximately 1 hour in the distributor. It can be seen that, for example, in these ladles with a molten mass contents of approximately 180 t the steel temperature drops by approximately 5° C./hour. This drop of the steel temperature in the distributor can be kept relatively small and depends substantially on
the residence time of the steel in the distributor, i.e., the casting output and
the insulation of the distributor.
The absolute temperature with which the steel flows into the distributor is predetermined by the continuous casting operation, is adjusted by the steel mill and depends on, for example,
ladle transport times,
ladle age and
ladle lining, which result often in deviations from the nominal temperature because of an uncontrolled operation process.
FIG. 6 represents the casting window defined by the steel temperature in the distributor and the maximum possible casting speed.
The casting window ( 4 ) is defined by an upper ( 3 . 0 ) and a lower ( 3 . 1 ) temperature limit. Moreover, in addition to the steel temperature in the casting mold ( 3 . 3 ), the area of the liquids temperature ( 3 . 4 ) of, for example, low-carbon steel qualities, is illustrated. The steel temperature in the casting mold increases for a constant steel temperature in the distributor with
greater distributor volume,
improved distributor insulation,
use of magneto-electro brake in the casting mold.
The FIG. 6 represents three molten masses with different distributor temperatures and thus different maximum possible casting speeds, but, for example, identical temperature loss of 5° C./hour.
In detail, these three situation in the casting window ( 4 ) are as follows. In the case ( 4 . 1 ), the steel temperature at the start of casting is 1,570° C. and makes possible a maximum casting speed ( 1 . 8 ) of 4.0 m/min., and after 1 hour casting time at the end of the ladle casting time the steel temperature of 1,565° C. allows for a maximum casting speed of 4.5 m/min.
In the case ( 4 . 2 ), the steel temperature in the distributor at the start of casting of the melt is 1,560° C. and at the end of casting 1,555° C. which makes possible a maximum casting speed of 5.0 m/min. and of 5.85 m/min. at the end of casting.
In the case ( 4 . 3 ), the temperature is 1,550° C. and makes possible a casting speed of 7.2 m/min. and at the end of casting, with a temperature of 1,545° C., a casting speed of >8 m/min. The speed of a maximum of 8 m/min. can be adjusted when reaching a temperature of approximately 1,548° C.
FIG. 7 illustrates the configuration of a semi-automation or a full automation/autopilot for casting in a high speed plant.
The device is comprised of a steel ladle ( 5 ), a distributor ( 6 ) with a stopper or slide closure ( 6 . 1 ) as well as a discontinuous or continuous temperature measurement in the distributor, a continuous casting plant with oscillating casting mold ( 1 ) and adjustable narrow sides ( 12 ) as well as removal rollers ( 6 . 3 ) which are driven by a motor ( 6 . 3 . 1 ) and which remove the strand at a controlled casting speed ( 1 . 8 ).
The following data acquisition is required for a full automation/autopilot:
temperature measurement of the steel in the distributor ( 6 . 2 ) in ° C.;
stopper movement or slide movement ( 6 . 1 . 1 ) in dy/dt;
heat flow measurement of the faces ( 7 ) in MW/m 2.
heat flow measurement of the narrow sides ( 8 ) in MW/m 2;
stopper movement
movement of the meniscus ( 9 ) in dx/dt; and
actual casting speed ( 1 . 8 ) in m/min.
These data are compared in an online computer ( 10 ) with the limits. With preconditions such as
a stopper movement of dy/dt of ±0, i.e., a “clean steel” which does not lead to a significant oxidic deposition within the SEN as well as to no stopper and SEN erosion,
a constant heat flow, within the faces at constant casting speed with a tolerance of a maximum of 0.1 MW/m 2 over the casting time and relative to one another,
a meniscus movement of a maximum of ±5 mm for a casting time of 60 seconds,
a heat flow ratio of the narrow sides to the faces of >0.9 and <0.4 the system interface ( 11 ) in the form of a “joystick” having the four functions
+/− casting speed and
+/− taper for the individual narrow sides and representing a semi-automation, can be switched to full automation or the status of autopilot in an operatively safe and thus breakout-free way (<0.5 percent).
The full automation corrects with the casting operation the conicity adjustments of each individual narrow side based on the heat flow ratios between the narrow sides and the faces outside of a narrow side/faces ratio of, for example, 0.8 > N W > 0.5 .
and automatically adjusts the maximum possible casting speed which is possible as a result of the steel temperature in the distributor and the provided equation.
The invention makes possible a reproducible operation of the continuous casting plant with maximum possible productivity and controlled strand quality while avoiding breakout.
List of Reference Numerals
( 1 ) slab casting mold with oscillation
( 1 . 1 .) hopper
( 1 . 2 ) narrow sides of casting mold
( 1 . 2 . 1 ) narrow side of the operator side (NO)
( 1 . 2 . 2 ) narrow side of the drive side (ND)
( 1 . 2 . 3 ) adjusting cylinder
( 1 . 3 ) faces
( 1 . 3 . 1 ) face, fixed, or backside, WF
( 1 . 3 . 2 ) face loose side or backside, WL
( 1 . 4 ) liquid steel
( 1 . 5 ) submerged entry nozzle, SEN
( 1 . 6 ) casting powder
( 1 . 6 . 1 . 1 ) casting slag film between casting mold and strand shell
( 1 . 7 ) strand
( 1 . 7 . 1 ) strand shell
( 1 . 7 . 2 ) meniscus
( 1 . 8 ) casting speed, V C
( 1 . 8 . 1 ) casting time t., after which the steel temperature is in equilibrium with the distributor
( 3 ) upper temperature limit
( 3 . 1 ) lower temperature limit
( 3 . 3 ) steel temperature in the casting mold
( 3 . 4 ) area of the liquids temperature of “low carbon” steel qualities
( 3 . 5 ) causes of an increase of the steel temperature in the casting mold at controlled temperature of the steel in the distributor inlet
( 4 ) casting window with three molten masses of different temperatures in the distributor and identical temperature loss of 5° C./hour in the casting window of steel temperature/casting speed
( 4 . 1 ) situation 1 with a molten mass which results in a steel temperature in the distributor of 1,570° C. at the start of casting and 1,565° C. at the end of casting and allows for a casting speed of 4.0 and a maximum of 4.5 m/min.
( 4 . 2 ) situation 2 with a molten mass which results in a steel temperature in the distributor of 1,560° C. at the beginning of casting and 1,560° C. at the end of casting and allows a casting speed of 5.0 and a maximum of 5.85 m/min
( 4 . 3 ) situation 3 with the molten mass results in a steel temperature in the distributor of 1,500° C. at the start of casting and 1,545° C. at the end of casting and allows a casting speed of 7.0 and >8.0 m/min
( 5 ) steel ladle
( 6 ) distributor
( 6 . 1 ) stopper or slide closure
( 6 . 1 . 1 ) stopper or slide movement
( 6 . 2 ) discontinuous or continuous temperature measurement of the steel in the distributor
( 6 . 3 ) driven removal rollers
( 6 . 3 . 1 ) drive motor
( 7 ) heat flow measurement in MW/m 2 of the faces
( 7 . 1 ) faces of the backside, fixed side WF
( 7 . 2 ) faces of the loose side, WL
( 8 ) heat flow measurement in MW/m 2 of the narrow sides
( 8 . 1 ) heat flow measurement of the operator side (NO)
( 8 . 2 ) heat flow measurement of the drive side (ND)
( 8 . 3 ) heat flow ratio narrow sides/faces
( 8 . 3 . 1 ) heat flow ratio operator-narrow side/faces ( NO , NO ) ( WL WF )
( 8 . 3 . 2 ) heat flow ratio drive narrow side/faces ( ND , NO ) ( WL WF )
( 9 ) menisous movement dx/dt
( 10 ) online computer
( 10 . 1 ) limits
( 11 ) system interface “joystick”
( 11 . 1 ) full automation/autopilot status
( 11 . 2 ) alarm for taking over in semi-automation | The invention relates to a method for automatically opening a high-speed continuous casting plant According to said method the stopping or slide movement, the modification of the steel level, the heat currents through the mold walls, the temperature of the liquid metal and the drawing-off speed are measured over the casting time, supplied to a computer and compared with predetermined limit values for an automatic operating mode. | 1 |
[0001] This application claims priority from copending provisional application Serial No. 60/369,632, filed Apr. 3, 2002, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND
[0002] This invention relates to methods and pharmaceutical compositions for providing hormone replacement therapy in perimenopausal, menopausal, and postmenopausal women through the continuous administration of combinations of conjugated estrogens and trimegestone.
[0003] Menopause is generally defined as the last natural menstrual period and is characterized by the cessation of ovarian function, leading to the substantial diminution of circulating estrogen in the bloodstream. Menopause is usually identified, in retrospect, after 12 months of amenorrhea. It is usually not a sudden event, but is often preceded by a time of irregular menstrual cycles prior to eventual cessation of menses. Following the cessation of menstruation, the decline in endogenous estrogen concentrations is typically rapid. There is a decrease in serum estrogens from circulating levels ranging from 40-250 pg/mL of estradiol and 40-170 pg/mL of estrone during ovulatory cycles to less than 15 pg/mL of estradiol and 30 pg/mL of estrone in postmenopausal women.
[0004] As these estrogens decline during the time preceding (perimenopause) and following the menopause (postmenopause), various physiological changes may result, including vulvar and vaginal atrophy causing vaginal dryness, pruritus and dyspareunia, and vasomotor instability manifested as hot flushes. Other menopausal disturbances may include depression, insomnia, and nervousness. The long-term physiologic effects of postmenopausal estrogen deprivation may result in significant morbidity and mortality due to increase in the risk factors for cardiovascular disease and osteoporosis. Menopausal changes in blood lipid levels, a major component of the pathogenesis of coronary heart disease (CHD), may be precursors to increased incidence of ischemic heart disease, atherosclerosis, and other cardiovascular disease. A rapid decrease in bone mass of both cortical (spine) and trabecular (hip) bone can be seen immediately after the menopause, with a total bone mass loss of 1% to 5% per year, continuing for 10 to 15 years.
[0005] Estrogen replacement therapy (ERT) is beneficial for symptomatic relief of hot flushes and genital atrophy and for prevention of postmenopausal osteoporosis. ERT has been recognized as an advantageous treatment for relief of vasomotor symptoms. There is no acceptable alternative to estrogen treatment for the atrophic changes in the vagina; estrogen therapy increases the vaginal mucosa and decreases vaginal dryness. Long term ERT is the key to preventing osteoporosis because it decreases bone loss, reduces spine and hip fracture, and prevents loss of height. In addition, ERT has been shown to be effective in increasing high density lipoprotein-cholesterol (HDL-C) and in reducing low density lipoprotein cholesterol (LDL-C), affording possible protection against CHD. ERT also can provide antioxidant protection against free radical mediated disorders or disease states. Estrogens have also been reported to confer neuroprotection, and inhibit neurodegenerative disorders, such as Alzheimer's disease (see U.S. Pat. No. 5,554,601, which is hereby incorporated by reference). The following table contains a list of some of the estrogen preparations currently available in the US and Europe. Listings of such preparations are available in such as the Physicians' Desk Reference, The Orange Book, and the European equivalents thereof.
Estrogen replacement therapies available in the United States and/or Europe Generic Name Brand Name Strength Oral estrogens Conjugated equine Premarin 0.3, 0.625, 0.9, 1.25, 2.5 mg estrogens (natural) Conjugated estrogens Cenestin 0.625, 0.9 mg (synthetic) Esterified estrogens (75-80% Estratab 0.3, 0.625, 1.25, 2.5 mg estrone sulfate, 6-15% equilin sulfate derived from plant sterols) Estropipate (Piperazine Ogen Ortho-Est 0.625, 1.25, 2.5 mg estrone sulfate) Micronized estradiol Estrace 0.5, 1.0, 2.0 mg Raloxifene (SERM) Evista 60 mg Esterified estrogens and Estratest 1.25 mg esterified estrogen and methylestosterone 2.5 mg methylestosterone Estratest HS 0.625 mg esterified estrogen and 1.25 mg methylestosterone Estradiol valerate Climaval 1 mg, 2 mg Estradiol Elleste Solo 1 mg, 2 mg Estradiol Estrofem 2 mg Estradiol Estrofem Forte 4 mg Piperazine esterone sulfate Harmogen 1.5 mg Combination Product: Estrone Hormonin 1.4 mg Estradiol 0.6 mg Estriol 0.27 mg Estradiol valerate Progynova 1 mg, 2 mg Estradiol Zumenon 1 mg, 2 mg Transdermal estrogens Estradiol Alora (twice wkly) 0.025, 0.0375, 0.05, 0.075, Climara (weekly) 0.1 mg of estradiol released Estraderm (2× wkly) daily (dose options for various Fem Patch (wkly) products) Vivelle (twice wkly) Estradiol Dermestril 25, 50, 100 μg Estradiol Estraderm 25, 50, 100 μg Estradiol Evorel (Systen) 25, 50, 75, 100 μg Estradiol Fematrix 40, 80 μg Estradiol Menorest 25, 37.5, 50, 75 μg Estradiol Progynova TS 50, 100 μg And TS Forte (Climara) Vaginal estrogens Conjugated equine estrogens Premarin vaginal cream 0.625 mg/g Dienestrol Ortho dienestrol cream 0.1 mg/g Estradiol Estring 7.5 μg Estropipate Ogen vaginal cream 1.5 mg/g Micronized estradiol Estrace vaginal cream 1.0 mg/g
[0006] To minimize the occurrence of estrogen-related side effects and to maximize the benefit-risk ratio, the lowest dose effective in relief of symptoms and prevention of osteoporosis should be used. Although ERT reduces the relative risk (RR) for ischemic heart disease (RR, 0.50) and osteoporosis (RR, 0.40), the relative risk of endometrial cancer for postmenopausal women with a uterus may be increased. There are extensive clinical data showing that the relative risk of endometrial cancer can be reduced by the addition of a progestin, either sequentially or continuously. The addition of a progestin to estrogen therapy prevents estrogen-induced endometrial proliferation. Continuous combined hormone replacement therapy (HRT), with appropriate doses of daily estrogen and progestin, has been shown to be effective in relieving vaginal atrophy and vasomotor symptoms, preventing postmenopausal osteoporosis, and reducing the risk of endometrial cancer by prevention of endometrial hyperplasia. The following table contains a list of some currently available oral combination HRT products. Listings of such preparations are available in such as the Physicians' Desk Reference, The Orange Book, and the European equivalents thereof.
Oral Combination HRT Products Brand Name Estrogen/Progestin Strengths Activelle Estradiol 1 mg Norethisterone acetate (NETA) 0.5 mg Climagest Estradiol valerate (Climaval) 1 or 2 mg Norethisterone (NET) 1 mg, days 17-28 Cyclo Progynova Estradiol valerate 1 or 2 mg, days 1-21 Levonorgestrel 250 or 500 μg, days 2-21 Elleste Duet Estradiol 1 or 2 mg Norethisterone acetate 1 mg, days 17-28 Femoston Estradiol 1 or 2 mg Dydrogesterone 10 or 20 mg Kliogest Estradiol 2 mg Norethisterone acetate 1 mg Improvera Piperazine estrone sulfate 1.5 mg Medroxyprogesterone acetate 10 mg, days 17-28 (MPA) Nuvelle Estradiol valerate (Progynova) 2 mg Levonorgestrel 75 μg, days 17-28 Premphase Conjugated estrogens 0.625 mg MPA 5.0 mg, days 15-28 Prempro Conjugated estrogens 0.625 mg MPA 2.5 or 5.0 mg Trisequens Estradiol 2 or 4 mg, days 1-22 And Norethisterone 1 mg, days 23-28 Trisequens Forte 1 mg, days 13-22 Ortho-Prefest Estradiol 1.0 mg, days 1-6 Norgestimate 0.09 mg, days 4-6 Femhrt 1/5 Ethinyl estradiol 5 μg Norethindrone acetate 1.0 mg Totelle Estradiol 2.0 mg Trimegestone 0.5 mg, days 17-28
[0007] Since it is possible that progestins ameliorate the favorable estrogen effects on lipids and may potentially impair of glucose tolerance, it is desirable, and an objective to find the lowest dose estrogen plus progestin HRT product, which also minimizes or eliminates endometrial hyperplasia. In addition, a major factor affecting a woman's decision to start and to continue taking HRT is vaginal bleeding, and many women would prefer a bleed-free product. Therefore, another objective is to provide the lowest effective dose which provides an acceptable bleeding pattern. Doses as low as NETA 0.5 mg, NET 0.35 mg, MPA 1.5 mg, levonorgesterel 0.25 mg, and dydrogesterone 5 mg have been used previously in continuous uninterrupted HRT regimens.
DESCRIPTION OF THE INVENTION
[0008] The purpose of this invention is to provide a new low dose HRT product, containing a low dosage of conjugated estrogens and the progestin, trimegestone. This invention provides a method of treating or inhibiting menopausal or postmenopausal disorders in a perimenopausal, menopausal, or postmenopausal woman in need thereof, which comprises providing to said woman, continuously and uninterruptedly over the treatment period, a combination of a daily dosage of between 0.2 mg to 0.45 mg conjugated estrogens (natural or synthetic) and a daily dosage of between 0.03 mg to 0.0625 mg trimegestone (TMG). The dosage is preferably provided as a pharmaceutical composition for use in treating menopausal or postmenopausal disorders which comprises a combination of conjugated estrogens and TMG. This invention further provides a pharmaceutical pack containing the daily dosage units of conjugated estrogen and TMG for continuous daily administration.
[0009] Conjugated estrogens refer to estrogenic steroidal substances in which one or more functional groups (typically hydroxyl groups) on the steroid exists as a conjugate (typically a sulfate or glucuronide). The conjugated estrogens may be a single conjugated estrogen, or may consist of mixtures of various conjugated estrogens. Numerous conjugated estrogens are described in the literature or are commercially available that are capable of being formulated for use in this invention either as a unitary estrogen, or may be mixed together with other synthetic and/or natural estrogens.
[0010] Conjugated estrogens may also contain other steroidal or non-steroidal compounds, which may, or may not, contribute to the overall biological effect. Such compounds include, but are not limited to, unconjugated estrogens, androstanes, and pregnanes. Preferred conjugated estrogens for use in this invention are PREMARIN (conjugated equine estrogens, USP) and CENESTIN (synthetic conjugated estrogens, A).
[0011] PREMARIN (conjugated estrogens tablets, USP) for oral administration contains a mixture of estrogens obtained exclusively from natural sources, occurring as the sodium salts of water-soluble estrogen sulfates blended to represent the average composition of material derived from pregnant mares' urine. It is a mixture of sodium estrone sulfate and sodium equilin sulfate, and at least the following 8 concomitant components, also as sodium sulfate conjugates: 17α-dihydroequilin, 17α-estradiol, Δ8,9-dehydroestrone, 17β-dihydroequilin, 17β-estradiol, equilenin, 17α-dihydroequilenin, and 17β-dihydroequilenin. PREMARIN is indicated in the treatment of moderate to severe vasomotor symptoms associated with the menopause; treatment of vulvar and vaginal atrophy; and prevention of osteoporosis, as well as other indications approved for estrogen products.
[0012] CENESTIN (synthetic conjugated estrogens, A) tablets for oral administration contain a blend of 9 synthetic estrogenic substances: sodium estrone sulfate, sodium 17α-dihydroequilin sulfate, sodium 17α-estradiol sulfate, sodium equilenin sulfate, sodium 17α-dihydroequilenin sulfate, sodium equilin sulfate, sodium 17β-dihydroequilin sulfate, sodium 17β-estradiol sulfate, sodium 17α-dihydroequilenin sulfate. CENESTIN is indicated in the treatment of moderate to severe vasomotor symptoms associated with the menopause.
[0013] Trimegestone, is a synthetic progestin having the chemical name 17β-{(S)2-hydroxypropanoyl}-17-methyl-estra-4,9-dien-3-one.
[0014] PREMARIN, and CENESTIN are available from commercial sources (Wyeth-Ayerst—PREMARIN; Duramed—CENESTIN). TMG can prepared according to the procedure described in U.S. Pat. No. 5,399,685, which is hereby incorporated by reference.
[0015] It is preferred that the daily dosage of TMG is between 0.03 and 0.045 mg. It is more preferred that the daily dosage of TMG is 0.03 mg. It is preferred that the conjugated estrogen constituent is PREMARIN. It is preferred that the dosage of PREMARIN is between 0.3 mg per day and about 0.45 mg per day. The following table illustrates particularly preferred combinations of daily dosages of TMG and conjugated estrogens.
Conjugated Estrogens (mg/day) Trimegestone (mg/day) 0.45 0.0625 0.45 0.045 0.45 0.03 0.3 0.03 0.2 0.045 0.2 0.03
[0016] As used in accordance with this invention, the term “menopausal or postmenopausal disorder” refers to conditions, disorders, or disease states that are at least partially caused by the decreased estrogen production occurring during the perimenopausal, menopausal, or post-menopausal stages of a woman's life. Such disorders typically include, but are not limited to, one or more of, vaginal and vulvar atrophy, vasomotor instability, urinary incontinence, and increased risk of developing osteoporosis, cardiovascular disease, and diseases related to the oxidative damage from free radicals. As used herein, menopausal also includes conditions of decreased estrogen production that may be surgically, chemically, or be caused by a disease state which leads to premature diminution or cessation of ovarian function.
[0017] The term “daily” means that the dosage is to be administered at least once daily. The frequency may is preferred to be once daily, but may be more than once daily, provided that any specified daily dosage is not exceeded.
[0018] The term “combination” of conjugated estrogens and TMG means that the daily dosage of each of the components of t he combination is administered during the treatment day. The components of the combination are preferably administered at the same time; either as a unitary dosage form containing both components, or as separate dosage units; the components of the combination can be administered at different times during the day, provided that the desired daily dosage is achieved.
[0019] The term “continuous and uninterrupted” means that there is no break in the treatment regimen, during the treatment period. Thus, “continuous, uninterrupted administration” of a combination, means that the combination is administered at least once daily during the entire treatment period. It is expected that the treatment period for the combination of conjugated estrogens and TMG will be for at least 30 days, preferably 120 days, and most preferably as long term treatment, and possibly indefinite, as one of the primary reasons for administering combinations of conjugated estrogens and TMG is to treat or inhibit menopausal or postmenopausal disorders. Treatment periods also may vary depending on the symptoms to be treated. For example, for the treatment of vasomotor symptoms, it is preferred that the treatment may last from one month to several years, depending on the severity and duration of the symptoms. Physician evaluation along with patient interaction will assist the determination of the duration of treatment. For the treatment or inhibition of osteoporosis, it is preferred that the treatment period could last from six months to a number of years, or indefinitely.
[0020] This invention, also covers short term treatments or treatments of a finite term, that may be less than the 30 day preferred treatment period. It is anticipated that a patient may miss, or forget to take, one or a few dosages during the course of a treatment regimen, however, such patient is still considered to be receiving continuous, uninterrupted administration.
[0021] The term “fixed daily dosage” means that the same dosage is given every day during the treatment period. One aspect of this invention also covers situations in which a fixed daily dosage of the conjugated estrogens plus TMG combination is not given every day during the treatment period. For example, the dosage of a patient may need to be adjusted (either up or down), to achieve the desired effect during the middle of a treatment period.
[0022] The term “providing,” with respect to providing a dosage of one or both of the components of this invention, means either directly administering such a component of this invention, or administering a prodrug, derivative, or analog which will form the equivalent amount of the component within the body.
[0023] It is preferred that the conjugated estrogens plus TMG combinations of this invention are provided orally. The specific dosages of conjugated estrogens plus TMG combinations of this invention that are disclosed herein are oral dosages.
[0024] In accordance with this invention, the continuously and uninterruptedly providing a combination of a daily dosage of between 0.2 mg and 0.45 mg conjugated estrogens plus a daily dosage of between 0.03 mg and 0.0625 mg of trimegestone is useful in treating or inhibiting menopausal or postmenopausal disorders in perimenopausal, menopausal, or postmenopausal women. More particularly, the combinations described herein are useful in treating or inhibiting vaginal or vulvar atrophy; atrophic vaginitis; vaginal dryness; pruritus; dyspareunia; dysuria; frequent urination; urinary incontinence; urinary tract infections; vasomotor symptoms, including hot flushes, myalgia, arthralgia, insomnia, irritability, and the like; inhibiting or retarding bone demineralization; increasing bone mineral density; and treating or inhibiting osteoporosis.
[0025] The combinations of this invention also exert a cardioprotective effect in perimenopausal, menopausal, and postmenopausal women, and are therefore useful in lowering cholesterol, Lp(a), and LDL levels; inhibiting or treating hypercholesteremia; hyperlipidemia; cardiovascular disease; atherosclerosis; peripheral vascular disease; restenosis, and vasospasm; and inhibiting vascular wall damage from cellular events leading toward immune mediated vascular damage.
[0026] The combinations of this invention are antioxidants, and are therefore useful in inhibiting disorders or disease states which involve free radicals. More particularly, the combinations of this invention are useful in treating or inhibiting free radical involvement in the development of cancers, central nervous system disorders, Alzheimer's disease, bone disease, aging, inflammatory disorders, peripheral vascular disease, rheumatoid arthritis, autoimmune diseases, respiratory distress, emphysema, prevention of reperfusion injury, viral hepatitis, chronic active hepatitis, tuberculosis, psoriasis, systemic lupus erythematosus, amyotrophic lateral sclerosis, aging effects, adult respiratory distress syndrome, central nervous system trauma and stroke, or injury during reperfusion procedures.
[0027] The combinations of this invention are useful in treating or inhibiting dementias, neurodegenerative disorders, and Alzheimer's disease; providing neuroprotection or cognition enhancement.
[0028] The conjugated estrogens and trimegestone described in this invention can be either formulated as separate tablets or as a unitary combination tablet.
[0029] Either of the components or the combination may be formulated neat or may be combined with one or more pharmaceutically acceptable carriers for administration. For example, solid carriers include starch, lactose, dicalcium phosphate, microcrystalline cellulose, sucrose and kaolin, while liquid carriers include sterile water, polyethylene glycols, non-ionic surfactants and edible oils such as corn, peanut and sesame oils, as are appropriate to the nature of the active ingredient and the particular form of administration desired. Adjuvants customarily employed in the preparation of pharmaceutical compositions may be advantageously included, such as flavoring agents, coloring agents, preserving agents, and antioxidants, for example, vitamin E, ascorbic acid, BHT and BHA.
[0030] The preferred pharmaceutical compositions from the standpoint of ease of preparation and administration are solid compositions, particularly tablets and hard-filled or liquid-filled capsules. Oral administration of the compounds is preferred.
[0031] In the Physicians' Desk Reference, PREMARIN is described as containing calcium phosphate tribasic, calcium sulfate, carnuaba wax, cellulose, glyceryl monooleate, lactose, magneseum stearate, methyl cellulose, pharmaceutical glaze, polyethylene glycol, stearic acid, sucrose, and titanium dioxide as inactive ingredients. This would be a typical formulation for PREMARIN.
[0032] CENESTIN is described as containing ethylcellulose, hydroxypropyl methylcellulose, lactose monohydrate, magnesium stearate, polyethylene glycol, polysorbate 80, pregelatinized starch, titanium dioxide, and triethyl citrate as inactive ingredients. This would be a typical formulation for CENESTIN. Formulations covering CENESTIN are described in U.S. Pat. No. 5,908,638, which is hereby incorporated by reference.
[0033] TMG can be formulated in a number of ways, including in an overcoat consisting of a film or sugar coat, over an inert core, as described in U.S. Pat. No. 5,759,577, which is hereby incorporated by reference.
[0034] Conjugated estrogens and TMG can be formulated in a number of ways to provide a single combination dosage form. Conjugated estrogens can be incorporated within the core of a compressed tablet and the progestin can be placed in an overcoating consisting of a film or sugar coat, as described in U.S. Pat. No. 5,547,948, which is hereby incorporated by reference. The tablets described in U.S. Pat. No. 5,547,948 are suitable for formulation of the conjugated estrogens and TMG described in this invention as a unitary tablet. U.S. Pat. No. 5,908,638, which is hereby incorporated by reference, also describes combination tablets which are suitable for formulation of the conjugated estrogens and TMG described in this invention as a unitary tablet.
[0035] Conjugated estrogens may be formulated in a core containing the conjugated estrogens, and several components including alcohol, hydroxypropyl methyl cellulose, lactose monohydrate, magnesium stearate, and starch. The core can be covered with a coating made from components such as ethylcellulose, and triethyl citrate.
[0036] Both components can be incorporated in the compressed tablet core or in a tablet coating formulated to maintain drug stability and provide adequate oral bioavailability. For example, the progestin can be micronized.
[0037] Conjugated estrogens can be incorporated in granules, spheroids or other multiparticulate forms, and, if necessary, coated to provide adequate stability. These multiparticulates can be combined, in the appropriate proportions, with a powder blend, granulation or multiparticulates containing the progestin and incorporated into hard gelatin capsules.
[0038] Tablets of conjugated estrogens or TMG may also be cut in pieces, or crushed and placed in capsules for administration of dosages that are not specifically commercially available.
[0039] This invention also provides a pharmaceutical dose pack, containing any number of daily pharmaceutical dosage units. Preferably, and conventionally, the pack contains 28 tablets or multiples thereof. The pack should indicate that the dosage units are to be taken consecutively on a daily basis until the treatment period has ended, or until the pack has been completed. The next pack should be started on the next consecutive day. For combinations containing a unitary dosage tablet containing both conjugated estrogens and TMG, it is preferable that the pack contain one tablet corresponding to each day of administration. For combinations containing separate dosage units of conjugated estrogens and TMG, it is preferable that each one tablet of each correspond to each given day's administration, as indicated on the pill pack. | This invention relates to methods and pharmaceutical compositions for providing hormone replacement therapy in perimenopausal, menopausal, and postmenopausal women through the continuous administration of combinations of conjugated estrogens and trimegestone. | 0 |
FIELD OF THE INVENTION
The present invention relates generally to automotive ignition control systems, and more specifically to such systems including provisions for guarding against various input fault conditions.
BACKGROUND OF THE INVENTION
Computer control of automotive ignition systems has provided automobile manufacturers with the ability to gain highly sophisticated and reliable control over automotive ignition timing events while doing away with bulky and failure-prone mechanical components of previously known ignition systems. A typical computer-controlled automotive ignition system includes an engine control module (ECM) having a control computer operable to provide highly accurate ignition timing signals to an ignition control module which is, in turn, operable to control current, supplied by the automobile battery, through one or more ignition coils. The ignition control module typically consists of one or more integrated circuits coupled with a number of discrete electrical components and power switching devices. Functions of the module include reception of a number of ignition timing signals supplied by the ECM, logical manipulation of these signals to provide fault handling and controlled drive signals to the power switching devices connected to the corresponding number of ignition coils to dynamically control the current flowing through them.
Under normal operating conditions, the ignition control module receives an active one of a number of ignition timing signals, verifies that no other coil is currently being driven, and then activates the power switching device associated with that ignition timing signal. The ignition timing signal is typically activated for a sufficient duration to permit the current in the primary coil of the corresponding ignition coil to reach a predetermined current level, typically in the range of 6-10 amps. Once the predetermined coil current is achieved, the controlling signal to the power switching device is reduced to a level required to maintain a "hold" current therethrough. After a brief current limiting period, the ignition timing signal transitions to an inactive state and the power switching device is abruptly turned off. This abrupt transition of the power switching device from a conducting state to a non-conducting state stops the flow of current through the primary coil while leaving a high voltage condition thereacross. A resulting inductively-induced voltage spike occurs in the coil which causes a spark to occur across the gap of a spark plug connected to the coil secondary. This sequence is repeated for the remaining ignition coils in the system.
During the time period that the coil current is ramping to its hold level, the power dissipated by the power switching device is relatively low. However, during the current limiting period, a high level of power is dissipated by the power switching device since the voltage drop thereacross is defined by the battery voltage minus the voltage drop across the primary coil. This high voltage drop combined with the now high level of coil current results in a relatively high level of power that must be dissipated by the power switching device. If the power switching device is allowed to remain in this condition indefinitely, it will eventually be destroyed by excessive self-heating. Such continuous current flow may also eventually result in damage to, or destruction of, the ignition coil. It is therefore important to protect the system from input fault conditions that may cause the power switching device to remain on indefinitely.
Caution must be exercised, however, in protecting against such fault conditions. For example, if an ignition timing signal has remained in its activated state for an excessively long time period and the associated power switching device is simply turned off in an effort to protect the switching device and corresponding ignition coil, a spark event will occur at the associated spark plug as previously described. Unfortunately, this spark event will occur at a point in time when the piston is at a position other than that required for normal engine operation. Such a mis-timed spark event could cause damage to the piston and other engine components. It is therefore important not only to provide for protection against input fault conditions that may cause a power switching device to remain on indefinitely, but to further control the reduction of coil current in response thereto in such a fashion so as to avoid generation of an unwanted spark event.
What is therefore needed is an automotive ignition control system operable to "lock-out" an ignition timing signal exhibiting a fault condition corresponding to an ignition timing signal remaining active for an excessive time period, while responding normally to other functioning ignition timing signals. Such a system should further monitor the ignition timing signal exhibiting the fault condition, and resume normal operation with respect thereto if the faulty signal returns to normal operation. Ideally, such a system should accomplish the lock-out function by performing a slow, or "soft", shutdown of the associated coil current in fashion that prevents the production of a spark event. Under normal operating conditions, such a system should further prevent simultaneous activation of more than one power switching device.
SUMMARY OF THE INVENTION
The present invention addresses the foregoing concerns of the prior art computer controlled automotive ignition systems. In accordance with one aspect of the present invention an electrical load driving system comprises an electrical load, a load driving device operatively connected to the load and responsive to a load driving signal to enable current to flow from a source of current through the load, and a control circuit responsive to an active state of a load control signal to produce the load driving signal. The control circuit is operable to inhibit the load driving signal in response to the load control signal remaining in its active state for a predefined time period and disable further production of the load driving signal until the load control signal transitions from its inactive state to its active state.
In accordance with another aspect of the present invention, an electrical load driving system comprises a plurality of electrical loads, a plurality of load driving devices each operatively connected to a separate one of the loads and responsive to one of a corresponding plurality of load driving signals to enable current flow therethrough from a source of current, and a control circuit responsive to an active state of any one of a plurality of load control signals to produce a corresponding one of the plurality of load driving signals while inhibiting production of all other load driving signals. The control circuit is further responsive to an inactive state of the particular load control signal to inhibit production of only the corresponding load driving signal.
In accordance with yet another aspect of the present invention, an electrical load driving system comprises an electrically inductive load having a primary coil coupled to a secondary coil, a load driving device operatively connected to the primary coil, wherein the load driving device is responsive to an active state of a first signal to enable current to flow from a source of current through the load and to an abrupt transition from its active state to an inactive state of the first signal to produce a voltage spike in the secondary coil, and a control circuit responsive to an active state of a second signal to produce the active state of the first signal. The control circuit is operable to gradually decrease the first signal from its active state to its inactive state to avoid production of the voltage spike in the secondary coil in response to a fault condition associated with the second signal.
One object of the present invention is to provide an automotive ignition control system operable to "lock-out" an ignition timing signal exhibiting a fault condition corresponding to an ignition timing signal remaining active for an excessive time period, while responding normally to other normally functioning ignition timing signals.
Another object of the present invention is to provide such a system operable to further monitor the ignition timing signal exhibiting the fault condition, and resume normal operation with respect thereto if the faulty signal returns to normal operation.
Yet another object of the present invention is to provide such a system that accomplishes the lock-out function by performing a slow, or "soft", shutdown of the associated coil current in fashion that prevents the production of a spark event.
Still a further object of the present invention is to provide an automotive ignition control system operable to prevent simultaneous conduction of coil current through more than one ignition coil.
These and other objects of the present invention will become more apparent from the following description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of one preferred embodiment of an automotive ignition control system in accordance with one aspect of the present invention;
FIG. 2 is a block diagram illustration of one preferred embodiment of a control circuit particularly suited for use in the automotive ignition control system of FIG. 1, in accordance with another aspect of the present invention;
FIG. 3A is a plot illustrating some of the signals of the system of FIG. 1 during normal operation thereof;
FIG. 3B is a plot illustrating some of the signals of the system of FIG. 1 during a fault condition associated with one of the input EST signals;
FIG. 4 is a schematic diagram illustrating one preferred embodiment of a reference current generating circuit particularly suited for use with the control circuit of FIG. 2;
FIG. 5 is a schematic diagram illustrating one preferred embodiment of the block of circuitry labeled "A" in FIG. 2;
FIG. 6 is a schematic diagram illustrating one preferred embodiment of the block of circuitry labeled "B" in FIG. 2;
FIG. 7 is a schematic diagram illustrating one preferred embodiment of the block of circuitry labeled "C" in FIG. 2; and
FIG. 8 is a schematic diagram illustrating one preferred embodiment of the block of circuitry labeled "D" in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring now to FIG. 1, a diagrammatic illustration of one preferred embodiment of an automotive ignition control system 10, in accordance with one aspect of the present invention, is shown. System 10 includes an engine control module (ECM) 12, which is preferably microprocessor-based and is operable to control several engine and vehicle functions including the automotive ignition system. A power source 14, preferably an automotive battery, supplies ECM 12 with electrical power at input BATT. ECM 12 preferably includes a switch (not shown) which is responsive to an operator command for engine operation to switch battery voltage BATT to output IGN as is known in the art. Output IGN supplies switched battery voltage BATT to various engine and vehicle systems via signal path 16. Preferably, battery voltage BATT is within the range of approximately 12-16 volts, although the present invention contemplates battery voltages BATT of between approximately 7-24 volts.
As it relates to automotive ignition control system 10, ECM 12 is operable to produce a number of engine spark timing signals (EST) in accordance with engine ignition timing information computed from a number of engine and vehicle operating parameters as is known in the art. Although it is to be understood that ECM 12 may be operable to produce any number of such EST signals, and that automotive ignition control system 10 may be correspondingly operable to control any number of automotive ignition coils corresponding thereto, the figures shown and described herein will assume two EST inputs, EST1 provided by ECM 12 on signal path 20, and EST2 provided by ECM 12 on signal path 22.
Signals EST1 and EST2 are provided by ECM 12 to an automotive ignition control circuit 18 which is operable to process the EST signals and control automotive ignition coils C 1 and C 2 in accordance therewith. Preferably, automotive ignition control circuit 18 is formed of a single integrated circuit, using known integrated circuit fabrication techniques, although the present invention contemplates that automotive ignition control circuit 18 may be alternately constructed from discrete electrical components, or as an amalgamation of integrated circuits and discrete electrical components. In either case, circuit 18 includes a power supply input 24 receiving a suitable voltage V S , and a ground reference input 26.
Control signals EST1 and EST2 are provided to the control circuitry of the present invention 28, which is operable to supply a first gate control signal GC1 to gate drive control1 circuit 30, and a second gate control signal GC2 to gate drive control2 circuit 32. Gate drive control1 circuit 30 and gate drive control2 circuit 32 may be known gate drive control circuits, as will be discussed hereinafter, and are operable to provide gate drive signals GD1 and GD2, respectively. Automotive ignition control circuit 18 produces gate drive signals GD1 and GD2 as outputs thereof, which are used to control power switching devices as will be described more fully hereinafter. Control circuit 28 is further operable to provide a signal DOFF to each of the gate drive control circuits 30 and 32, to deactivate gate drive signals GD1 and GD2 as will be discussed hereinafter.
Gate drive signal GD1 is connected to a control input of a first power switching device, and gate drive signal GD2 is likewise connected to a control input of a second power switching device. Preferably, each of the power switching devices are known power transistors. Examples of such power transistors suitable for use with the present invention include an insulated gate bipolar transistor (IGBT) as shown in FIG. 1, a power MOSFET, a bipolar power transistor, or the like. Each of the foregoing transistor examples include a control input which will be referred to hereinafter as a "gate". As shown in FIG. 1, gate drive output GD1 is preferably connected to a gate 34 of IGBT1, wherein IGBT1 has a collector connected to a primary coil 36 of automotive ignition coil C 1 . A secondary ignition coil 38 is coupled to primary ignition coil 36 and has an output connected to at least one spark plug SP1. The opposite end of primary coil 36 is connected to switched battery voltage IGN via signal path 16. When gate drive signal GD1 is in an active state, IGBT1 is operable to conduct load current I L1 therethrough from IGN through primary coil 36, and to ground potential through sense resistor R S connected to an emitter thereof. At any given time, primary coil 36 has a voltage V P thereacross which will be discussed more fully hereinafter.
Gate drive signal GD2 is similarly connected to a gate 40 of IGBT2, which has a collector connected to a primary coil 42 of automotive ignition coil C 2 , and an emitter connected to sense resistor R S . A secondary coil 44 is coupled to primary coil 42, and has an output connected to one or more spark plugs SP2. As with primary coil 36, primary coil 42 is connected to switched battery voltage IGN via signal path 16. IGBT2 operates identically to IGBT1 in that an active state of gate drive signal GD2 causes IGBT2 to conduct load current I L2 from IGN through primary coil 42, through IGBT2, and to ground potential through sense resistor R S . The common connection of the emitters of IGBT1 and IGBT2 and sense resistor R S is fed back through circuit 18 to a current limit error amplifier 46. Current limit error amplifier 46 is connected to gate drive control1 circuit 30 and gate drive control2 circuit 32 preferably via a pair of signals paths 48 and 50 as shown in FIG. 1. In operation, current limit error amplifier 46 is operable to sense a voltage across sense resistor R S and modulate gate drive signals GD1 and GD2 to reduced signal levels when the voltage across R S reaches a predefined level as is known in the art.
Referring now to FIG. 2, one preferred embodiment 100 of control circuit 28 of FIG. 1, in accordance with another aspect of the present invention, is shown. Control circuit 100 includes a first input 102 for receiving a logical representation of ignition timing signal ESTI thereat, and a second input 104 for receiving a logical representation of ignition timing signal EST2 thereat. Input 102 is connected to an inverter G1, the output of which is connected to one input of a three input NOR gate G2 and to a reset input of an RS flip-flop L1. The Q output of L1 is connected to a second input of NOR gate G2, and a set input of L1 is connected to an output of a two input NOR gate G3.
An output of NOR gate G2 is connected to a set input of RS flip-flop L2, one input of a two input NOR gate G7, and to gate drive control 1 circuit 30. The output of NOR gate G2 provides gate control signal GC1 to gate drive control1 circuit 30 as shown in FIG. 1. A Q output of L2 is connected to one input of a three input NOR gate G5 and to one input of a two input NOR gate G6. A reset input of L2 is connected to a reset input of an RS flip-flop L3, and to an output of an inverter G8. The Q output of L3 is connected to the remaining input of NOR gate G2 and to one input of a two input NOR gate G3. The set input of L3 is connected to an output of NOR gate G5, and to the remaining input of NOR gate G7. The output of NOR gate G5 is connected to gate drive control2 circuit 32, and provides gate control signal GC2 thereto.
A second input of NOR gate G5 is connected to a Q output of an RS flip-flop L4, and the remaining input of NOR gate G5 is connected to an output of an inverter G4, and to a reset input of L4. The input of inverter G4 provides input 104 to ignition timing signal EST2. A set input of L4 is connected to an output of NOR gate G6. The remaining inputs of NOR gates G3 and G6 are connected together, and further to an output of a comparator C3. The input of inverter G8 is connected to an output of another comparator C4.
The output of G7, labeled G7OUT in FIG. 2, is connected to a reset input of an RS flip-flop L5, a reset input of an RS flip-flop L6, and to the base of an NPN transistor Q1. A set input of L5 is connected to an output of a comparator C1, and also to a voltage source TOREF, which provides a reference voltage to an inverting input of C1. The Qbar output of L5, labeled QB5 in FIG. 2, is connected to a control input of a current source I1, an input of a two input NOR gate G10, and to the base of an NPN transistor Q5. The remaining input of NOR gate G10 is connected to the Q output of L6. The Qbar output of L6 is connected to a control input of a voltage follower F1 and to an output current control circuit 108. The output of NOR gate G10 is connected to the base of an NPN transistor Q2, which has an emitter connected to the emitter of Q1 and to ground potential. The set input of L6 is connected to an output of comparator C2 and to the collector of transistor Q5. A non-inverting input of comparator C2 is connected to a positive output of a voltage source VOFFSET, the negative end of which is connected to a voltage follower F2. Voltage follower F2 has a pair of inputs thereto, provided by GD1 and GD2, respectively. The inverting input of comparator C2 is connected to a signal path labeled CEXT in FIG. 2.
Signal path CEXT is connected to the collectors of transistors Q1 and Q2, a non-inverting input of comparator C1, the current receiving end of current source I1, of input to a second current source I2, and to a capacitor C EXT . An opposite end of current source I1 is connected to supply voltage V S , and output of current source I2 is connected to ground potential. The control input QB5 to current source I1 is passed through an inverter G9, the output of which provides a control input to current source I2. CEXT is also connected to a non-inverting input of comparator C4, which has an inverting input connected to a reference voltage CDREF.
Signal path CEXT is further connected to a non-inverting input of a voltage follower-connected comparator F1, an output of which is labeled V F . V F is connected to a non-inverting input of comparator C3, which has an inverting input connected to a reference voltage SSDREF. V F is also connected to a voltage limiter 106, which has an output connected to the bases of PNP transistors Q3 and Q4. The collectors of Q3 and Q4 are connected together, and are further connected to the output current control circuit 108. The emitter of Q3 is connected to GD1, and the emitter of Q4 is connected to GD2. The output current control circuit 108 supplies signal path DOFF to gate drive control 1 circuit 30 and gate drive control2 circuit 32.
The control circuit 100 of FIG. 2 generally includes two circuit functions; (1) lock-out logic circuitry; and (2) time-out/soft-shutdown (TO/SSD) circuitry. The lock-out control logic controls drive circuitry 30 and 32, and sends, as well as receives, control signals from the TO/SSD circuitry. The TO/SSD circuitry includes analog circuitry that dynamically controls gate drive signals GD1 and GD2 during a soft-shutdown event, which will be more fully described hereinafter.
The basic operation of control circuit 100, as it relates to the automotive ignition control system 10 of FIG. 1, will now be described, followed by a more detailed description of the lock-out logic and TO/SSD functions of control circuitry 100. Thereafter, preferred circuit embodiments of the circuit blocks labeled A, B, C, and D in FIG. 2, will be described in detail.
BASIC OPERATION OF CONTROL CIRCUIT 100
Referring now to FIGS. 1, 2, and 3A, all circuit functions within control circuit 100 are reset by the condition of both EST1 and EST2 being in an inactive state. Preferably, EST1 and EST2 are inactive at a logic low level, and are active at a logic high level. However, the present invention contemplates that an inactive state of EST1 and EST2 may alternatively be a logic high level, and an active state thereof be a logic low level. In any case, an ignition timing input sequence begins with transition of either EST input from an inactive to an active state. If the lock-out logic feature of circuit 100 determines that the other EST signal is already active, the output corresponding to the active EST signal (either GD1 or GD2), is commanded to an active state from its inactive state, which turns on a corresponding drive transistor (IGBT1 or IGBT2). Preferably, the active state of gate drive outputs GD1 and GD2 correspond to a logic high level, while an inactive state thereof corresponds to a logic low level. Alternatively, as with the EST signals, the converse may be true. In either case, commanding the respective drive transistor on results in a current ramp-up in the corresponding ignition coil (C 1 or C 2 ).
The foregoing conditions are shown in FIG. 3A as signals 150 (EST1), 152 (GD1), and 154 (I L1 ). During the "reset" period, the voltage V P .156 across the primary coil 36 of coil C 1 is at a level defined by the voltage V P1 . At time t 1 , EST1 150 transitions to its active state, which causes gate drive voltage GD1 152 to transition to V RAMP . In response thereto, the load current I L1 154 begins to increase in value. During this time, the voltage V P drops to near zero. At time t 2 , I L1 reaches its "hold" value I H (the desired maximum coil current level), and current limit error amplifier 46 responds thereto by modulating gate drive signal GD1 to a reduced "hold" voltage V H . During this current limiting period following t 2 , the voltage V P increases to a value VP P2 less than V P1 .
Concurrently with the foregoing system operation, capacitor C EXT (FIG. 2) begins charging at t 1 via current source I1, and continues to charge during the time period from t 2 to t 3 . As shown by signal 155 in FIG. 3A, the voltage V CEXT across capacitor C EXT thus ramps to a level V X at time t 3 , which is less than the reference voltage TOREF (FIG. 2). Under normal operation, EST1 transitions to its inactive state before V CEXT ramps to a level sufficient to qualify as an "excessive" dwell. Thus, at time t 3 , EST1 150 transitions to its inactive state, thereby transitioning GD1 152, I L1 154 and V CEXT 155 to their inactive states, respectively. Due to the current level I H of the current I L1 flowing through coil C 1 , transitioning GD1 152 to its inactive state causes a voltage spike 158 after t 3 , which results in a spark event at spark plug SP1. The voltage V P 156 returns thereafter to its reset value of V P1 .
Referring now to FIGS. 1, 2, and 3B, a "soft-shutdown" event will now be described. The operation of EST1 160, GD1 162, I L1 164, and V P 174 are identical to their counterpart signals in FIG. 3A until time t 3 . As shown in FIG. 3B, from time t 1 forward, the voltage V CEXT (across capacitor C EXT ) is linearly increasing under the influence of current source I1. If EST1 160 does not transition to its inactive state at time t 3 as expected, a time-out/soft-shutdown event is initiated thereafter when V CEXT charges to voltage V TOREF at subsequent time t 4 . V TOREF corresponds to the reference voltage TOREF at the inverting input of capacitor C1 of FIG. 2. At time t 4 , capacitor C EXT is used for a second function; that of providing a reference voltage for the IGBT during the soft-shutdown event.
At time t 4 , the capacitor voltage V CEXT is simultaneously reduced to a value V H+ 168 and forced through voltage follower F1 and voltage limiter 106 onto GD1. V H+ corresponds to the voltage V H previously on GD1 plus a small offset voltage VOFFSET (see voltage follower F2 of FIG. 2). Once forced onto GD1, the voltage V CEXT on capacitor C EXT is slowly discharged via current source I2 as shown by linear portion 170 of signal V CEXT . V CEXT linearly decreases until it reaches a voltage V SSDREF , which is set at a voltage low enough to guarantee that the IGBT is effectively turned off. V SSDREF corresponds to the voltage reference SSDREF at the inverting input of capacitor C3 (FIG. 2). When V CEXT reaches V SSDREF , capacitor C EXT is completely discharged, as shown by portion 172 of signal V CEXT , in preparation for the next dwell event.
In response to the foregoing controlled discharge of capacitor C EXT , GD1 162 is linearly decreased to its inactive state and I LI 164 correspondingly decreases at a sufficiently slow rate to result in a controlled increase 176 of V P 174 from V P2 to V P1 . The controlled soft-shutdown of IGBT1 therefore does not result in the generation of a spark event at spark plug SP1. Circuitry 100 does not allow the next ignition timing event to start until it determines that capacitor C EXT is fully discharged so as to guarantee a full time-out period for the next incoming EST signal.
At the point V CEXT decreases to V SSDREF , the lock-out logic portion of circuitry 100 effectively "locks out" the offending EST1 signal, and will not further process the EST1 signal until it returns to its inactive state, which is shown in FIG. 3B as occurring at time t 5 . After t 5 , circuitry 100 will respond to a transition of EST1 from its inactive to its active state as previously described. Having provided a basic description of the time-out/soft shutdown mechanism, a more detailed discussion of how each of the timing and control events are implemented will now be presented. The lock-out control logic will be discussed first, followed by a detailed discussion of the TO/SSD circuitry assuming prior understanding of the lock-out logic function.
LOCK-OUT LOGIC
Referring to FIG. 2, inverters G1 and G4, NOR gates G2, G3, G5, and G6, and RS flip-flops L1-L4 comprise the "lock-out logic" of control circuitry 100. As will be discussed hereinafter, the lock-out logic circuitry prevents more than one gate drive output (GD1 and GD2) to be enabled at any time, and further prevents the start of a new ignition timing sequence (dwell cycle) until a time-out event in progress has completed and the TO/SSD capacitor C EXT has been discharged.
Initially, all EST signals (EST1 and EST2) are low, resetting L1 and L4. Using EST1 as an example hereinafter, a low-level EST1 signal disables GD1 by imposing a high level input signal on NOR gate G2. With any high input signal on G2, signal GC1 (output of G2) is low, thereby commanding GD1 to an inactive state so that IGBT1 is turned off. Assuming that all EST input signals have been inactive for a time period sufficient to have fully discharged capacitor C EXT , L2 and L3 will be reset, causing their Q outputs to be low. The foregoing description corresponds to a fully reset condition of control circuit 100.
As EST1 transitions to its active state, the output of inverter G1 transitions to a logic low level. With all three inputs to NOR gate G2 low, signal GC1 transitions to a logic high level. A high level GC1 signal causes gate drive control1 circuit 30 to turn on IGBT1 by raising the voltage at gate 34 to a level limited by voltage limiter 106. Voltage limiter circuitry 106 prevents excessive voltage from damaging the gate 34 of IGBT1, but must be set high enough to guarantee sufficient gate drive to permit conduction of the desired level of I L1 .
The high level GC1 signal also sets L2 such that the Q output thereof is at a logic high level, thereby preventing any high level signal appearing at input 104 (EST2) from propagating past NOR gate G5 (due to the logic high level of the corresponding input to G5). This action "locks out" any EST signal other than EST1, and thereby prevents more than one IGBT from being driven at any time. The "lock-out" of EST2 will be terminated only upon reset of L2. L2 (and L3) are reset only when the voltage V CEXT discharges to a level below the CDREF voltage reference connected to the inverting input of comparator C4. This mechanism thus prevents the start of a new ignition timing sequence (dwell cycle) with charge remaining on capacitor C EXT . This is necessary since a partially charged capacitor C EXT would result in a short time-out period on the next dwell cycle, which is an undesirable condition.
As previously discussed, EST1 would transition to its inactive state, during normal operation of system 10, before a time-out event occurs. In such a case, the logic low level of EST1 is passed through G1 and G2 to gate drive control1 circuit 30, and to NOR gate G7. With both inputs to G7 at a logic low level, signal G70UT transitions to a logic high level which resets L5 and turns on transistor Q1. The action of turning on Q1 causes a rapid discharge therethrough of capacitor C EXT . When the voltage V CEXT drops below reference voltage CDREF, the output of comparator C4 transitions to a low state, which causes the corresponding logic high level at the output of G8 to reset L2 and L3, thereby "unlocking" input 104 and allowing an active EST2 signal to command its associated gate drive control2 circuit 32 to drive transistor IGB2. Along with L2 and L3, L1 and L4 are also provided with a reset signal, through the action of comparator C3 and NOR gates G3 and G6, although L1 and L4 are only set when a time-out/soft-shutdown event occurs, which will be described hereinafter.
As previously discussed, if EST1 remains in an active state for an excessively long time period, a time-out/soft-shutdown event is triggered. During the course of events resulting from a subsequent soft-shutdown, voltage follower F1 is enabled via the Qbar output of L6, thereby forcing V CEXT to the output thereof so that V F equals V CEXT . When V F subsequently drops below SSDREF of comparator C3, pursuant to a soft-shutdown, the output of C3 transitions to a logic low level, which is supplied to NOR gates G3 and G6. With EST2 inactive or locked out, L3 is correspondingly reset so that its Q output is at a logic low level. With two logic low inputs to G3, the output of G3 transitions to a logic high level, thereby setting latch L1. L1's now high Q output prevents any high level signal at EST1 from propagating past G2. This sequence effectively locks out an offending "stuck high" EST signal, and allows normal operation of other EST inputs. L1 is, as described above, reset only when EST1 transitions back to a logic low level.
TIME-OUT/SOFT-SHUTDOWN CIRCUITRY
As previously described, under a fully reset condition, capacitor C EXT is fully discharged. When any EST signal transitions to its active state, current source I1 begins charging C EXT as shown by signal 166 of FIG. 3B. If the controlling EST signal remains in its active state for an excessively long time period, C EXT will charge to a voltage V TOREF , which is the threshold reference voltage of comparator C1. Preferably TOREF is a fixed voltage level that is relatively independent of supply voltage, temperature, and integrated circuit process parameters. TOREF is also modified by the output of comparator C1 to provide hysteresis in the comparing function. When V CEXT reaches V TOREF , the output of comparator C1 switches from a logic low state to a logic high state, setting L5. The on/off control of current sources I1 and I2 is dictated by the Qbar output of L5. When L5 is set, QB5 switches from a logic high level to a logic low level, thereby turning off current source I1 and turning on current source I2, which begins the discharge of C EXT . Additionally, the transition of QB5 from a logic high to a logic low level turns off transistor Q5 which was previously activated to hold the output of comparator C2 low. L6 was previously reset (when L5 was reset) by NOR gate G7, and its Q output is therefore now in a logic low state.
With QB5 and the Q output of L6 both at a logic low level, the output of NOR gate G10 transitions to a logic high level, thereby turning on transistor Q2. Preferably, Q2 is sized to be capable of rapidly discharging capacitor C EXT , which it does until L6 is set by a logic high level at the output of comparator C2. The output of comparator C2 switches from a logic low level to a logic high level when the voltage V CEXT drops below a level imposed on C2's non-inverting input by voltage follower F2.
Voltage follower F2 is designed so that the voltage imposed on C2's non-inverting input thereby is a few hundred millivolts above the voltage on GD1 (assuming EST1 is the active input). This results in C EXT being discharged down to a level just slightly above the voltage at GD1 (V H+ as shown in FIG. 3B). When that level is reached, C2 switches to a logic high level, thereby setting L6 so that its Q output switches to a logic high level. This causes the output of G10 to switch to a logic low level, which turns off transistor Q2.
The setting of L6 switches its Qbar output to a logic low level which enables voltage follower F1 to pass the voltage V CEXT at its non-inverting input to its output as V F . V F passes through voltage limiter 106, and through transistor Q3, so that a direct copy of V CEXT is imposed on GD1. Since current source I2 is currently active, C EXT is slowly discharged, resulting in a slow reduction of the voltage V CEXT imposed on the GD1 output. The rate of change of the GD1 voltage is designed to be slow enough that, for a given ignition coil inductance,.there is no appreciable voltage ring-up on the ignition coil primary due to the slowly decreasing current in IGBT1. This voltage slew rate is dictated primarily by the inductance of the ignition coil as described by relationship V=L*di/dt. This slew rate should be chosen such that no voltage capable of generating a spark or other dangerous voltage is generated on the coil secondary 38.
The discharge of C EXT continues until V CEXT is reduced to a level defined by SSDREF, which is the threshold reference voltage at the inverting input of comparator C3. Preferably, SSDREF is chosen to be a voltage below the gate threshold voltage of IGBT1, thereby guaranteeing that when V CEXT is equal to SSDREF, no current is flowing through IGBT1. When this level is reached, the output of comparator C3 switches to a logic low level, which is provided to NOR gates G3 and G6 as previously described. This signal causes termination of gate control signal GC1 by setting L1. The lock-out logic then causes a rapid discharge of C EXT via transistor Q1 by forcing G7out to a logic high level. C EXT is then rapidly discharged down to very near ground potential, as detected by comparator C4. When C4 detects that V CEXT is below CDREF, its output switches to a logic low level, which causes inverter G8 to reset L2 and L3. This action permits an active EST2 signal to proceed unimpeded, and the time out cycle can thus be restarted with a guarantee of a full C EXT charging cycle.
The inverters, NOR gates, and RS flip-flops shown in FIG. 2 may be of known construction and need not be further described herein. In one preferred embodiment, such devices are constructed from resistors and bipolar transistors. However, those skilled in the art will recognize that such devices may be constructed from other known electrical components without detracting from the scope of the present invention. In any case, preferred embodiments of the remaining circuits comprising control circuit 100 will now be described.
Referring now to FIG. 4, one preferred embodiment of a circuit 180 for generating bias and operating currents for control circuit 100 is shown. Transistors Q25, Q26, and Q27 comprise a known current mirror arrangement 182 connected to a second current mirror arrangement 184 composed of transistors Q28 and Q29, which passes the mirrored current through trans-coupled transistors Q30 and Q31. Resistor R18 is connected between the emitter of Q30 and ground potential, and a number of transistors Q X form a current mirror with Q25 and Q27 so as to supply current I REF . The reference current I REF is defined by the equation:
I.sub.REF =V.sub.t *ln(9)/R18.
I REF is a standard "delta V be " current and is generated by known circuitry. V t is the thermal voltage defined by well known equations. The temperature characteristic of I REF is generally positive, and the current is independent of supply voltage V S 24. Using base drive current I R , scaled copies of the current I REF are generated using R X and Q X to bias most of the internal circuitry of control circuit 100.
Referring now to FIG. 5, one preferred embodiment of the block A circuitry of FIG. 2 is shown. Transistors QSS1, QSS2, and QS8-12 make up a standard Darlington input comparator C1 which monitors the voltage V CEXT and compares this voltage to the reference voltage TOREF. The base of transistor QSS1 is connected to the collector of transistor QS28 and a resistor RREF1. The opposite end of RREF1 and one end of a resistor RREF2 are connected to the base of QS28, and the opposite end of RREF2 is connected to the emitter of QS28. The emitter of QS28 is further connected to one end of a resistor RREF3A, the opposite end of which is connected to resistor RREF3B and to the collector of a transistor QHYST1. The base of QHYST1 is connected to a resistor RHYST1 and to a collector of an output transistor QS12, of comparator C1.
The voltage TOREF provided at the base of transistor QSS1 is a pseudo-bandgap voltage developed across QS28 and resistors RREF3A and RREF3B. TOREF is approximately described by the equation:
TOREF= (I.sub.REF /2)*(RREF3A+RREF3B)!+(1+RREF1/RREF2)*Vbe.sub.QS28,
where I REF is the delta-Vbe reference current described with respect to FIG. 4 and Vbe QS28 is the base-to-emitter voltage of transistor QS28. Since diffused silicon integrated circuit resistors have a positive temperature coefficient, and NPN base-emitter voltages have a negative temperature coefficient, the values of RREF1, RREF2, RREF3A, and RREF3B can be chosen so that the magnitude of TOREF is substantially independent of temperature. The use of the known Vbe "multiplier" structure of QS28, RREF1, and RREF2 provides the circuit designer with greater flexibility in the level at which TOREF must be set to achieve temperature independence by permitting the use of non-integral multiples of Vbe voltages. A traditional voltage reference uses a series combination of NPN diodes to achieve the negative T.C. voltage used to offset the positive voltage across the silicon diffused resistors. This topology, however, limits the solution points for zero temperature coefficient performance to integral multiples of the silicon bandgap voltage (approximately 1.26 volts), each multiple corresponding to each diode on the diode stack. By using a Vbe multiplier of the type described herein, a non-integral number of Vbe's can be generated, thereby allowing the circuit to be designed for substantially temperature independent operation of TOREF at a wider range of voltages. Such a structure alternatively allows the TOREF reference voltage to be designed to have a non-zero temperature coefficient to offset any temperature dependencies in the associated circuitry. The calculations necessary to determine the required resistor values to achieve such a non-zero temperature coefficient for TOREF are known to those skilled in the art. In either case, the TOREF reference voltage is independent of supply voltage V S 24.
The rate at which the capacitor C EXT is charged and discharged is determined by the value of the external resistor R EXT . The voltage across R EXT , and thereby the current through it, is determined by the voltage established at the base of transistor QS6. Transistor QS6 is a PNP transistor having one collector connected to its base, a second collector connected to differential stage 202 comprising transistors QS13 and QS14, and an emitter connected to an emitter of NPN transistor QS7. QS7 is connected, in a voltage follower configuration, to NPN transistor QS2. The emitter of transistor QS2 is connected to a diode configured NPN transistor QSREF1, the emitter of which is connected to the collector and base of transistor QS4 and base of transistor QS13. Transistor QS4 is connected, in a current mirror arrangement, with transistor QS5, which has a collector connected to the emitters of transistors QS9 and QS10. The emitter of transistor QS4 is coupled to ground potential via resistor RS3, and the emitter of QS5 is coupled to ground through resistor RS4. The voltage V REXT is approximately described by the equation:
V.sub.REXT =(I.sub.REF *RS3)+Vbe.sub.QS4,
where it is assumed that the Vbe's of transistors QS6 and QS7 cancel with those of transistors QS2 and QSREF1. The voltage V REXT is thus the same voltage as that appearing at the base of transistor QS13, which is labeled THLO. THLO is a pseudo-bandgap voltage and, given the appropriate choice of RS3, can be designed to be substantially temperature independent. THLO is also independent of supply voltage V S 24.
Since one collector of QS6 is connected to its base, and is further connected to R EXT , the current flowing therethrough is mirrored to the remaining collector which is provided to the comparator composed of QS13 and QS14. The base of transistor QS14 is connected to a diode connected transistors QS25, which has an emitter connected to a collector of a transistor QS26. The base of transistor QS26 is connected to signal QB5 (FIG. 2). Transistors QS25 and QS26, and voltage THLO are designed such that when signal QB5 is low, transistor QS13 directs the R EXT current through current mirror 204, composed of transistors QS15 and QS16, and which comprises current source I2 (FIG. 2). Since the collector of QS16 is connected to capacitor C EXT , C EXT is discharged at a rate defined by the R EXT current flowing through current mirror 204. Preferably, transistors QS15 and QS16 are sized with respect to each other so as to scale the R EXT current replica to a magnitude necessary for the desired C EXT discharge rate.
On the other hand, when the signal QB5 is high, transistor QS14 directs the R EXT current through current mirror 206, composed of transistors QS17 and QS18, which is connected to a second current mirror 208, which is composed of transistors QS19 and QS24. Since the collector of transistor QS24 is connected to capacitor C EXT , current mirrors 206 and 208 comprise current source I1 (FIG. 2). As with current mirror 204, transistors QS17, QS18, QS19, and QS24 are sized to scale the R EXT current replica to a magnitude necessary for the desired charge rate of capacitor C EXT .
At the beginning of an ignition timing event, or dwell cycle, capacitor C EXT has been discharged by transistor Q1 which is driven by signal G7OUT. G7OUT is high when both EST signal inputs are low. This high G7OUT signal also resets L5 which causes signal QB5 to drive transistor QS26. QS26 sinks current through resistor RS10, thereby supplying base drive to PNP transistor QS23 which, in turn, supplies drive to the PNP current mirror composed of transistors QS19 and QS24. Since QS26 is turned on, the comparator composed of QS13 and QS14 is switched such that the R EXT replica current becomes a charging current as described hereinabove. Capacitor C EXT charges until its voltage reaches the same voltage as TOREF. At this point, which is the end of a time out period, comparator C2 switches, forcing the set input of L5 high. This forces the signal QB5 to a logic low level, which turns off transistor QS26. Transistor QSl3 is thus turned on and the capacitor C EXT begins discharging through current mirror 204. This discharging voltage is imposed, as will be described hereinafter, on the gate of IGBT1 to effect a soft-shutdown of the coil current I L1 . Also, as comparator C2 switches, transistor QHYSTl is turned on by transistor QS12, which pulls the circuit node connecting RREF3A and RREF3B to nearly ground potential. This action lowers TOREF, thereby resulting in hysteresis in the switch point of comparator C2. TOREF is returned to its previous level once the capacitor voltage V CEXT discharges to a level below the new TOREF voltage.
The foregoing charge/discharge cycle is completed only in the case of a persistent fault at one of the two EST inputs. In a normal dwell event, V CEXT does not reach the TOREF level, but is instead rapidly discharged when the G7OUT output switches high in response to all EST input signals being low.
Referring now to. FIG. 6, one preferred embodiment of circuit block B of FIG. 2 is shown. Outputs GD1 and GD2 are connected to the base of transistor QS88 and QS89, respectively. Transistors QS99 and QS100 are diode-connected transistors connected to the emitters of QS88 and QS89, respectively. The collectors of QS88 and QS89 are connected together and to a current mirror 222 formed by transistors QS84 and QS85. Diode-connected transistor QS87 has an emitter connected to a resistor RS43, which is connected to diode-connected transistor QS98. The emitters of QS98, 99 and 100 are connected together, and to a current mirror 220 composed of transistors QS81, 82, and 96. The base-collector connection of transistors QS87 is connected to the non-inverting input of comparator C2.
The circuitry of FIG. 6 is used to control the adjustment of the capacitor voltage V CEXT to approximately the same level as the current limit stage gate drive output voltage GD1. This adjustment is made to the capacitor voltage V CEXT immediately before the start of a soft-shutdown event. This rapid shift in the voltage V CEXT is necessary to compensate for the variation in gate voltage required for various IGBTs and varying current limit levels. By adjusting the capacitor voltage V CEXT to a level slightly above the gate voltage prior to beginning a soft-shutdown event, the amount of time before reduction in coil current begins to decrease can be more easily controlled. This effectively permits a tighter control over the time-out time period. Control of this time-out time period is important in order to minimize the amount of time that the IGBT is in its highest power dissipation modes, which are (1) steady-state current limiting, and (2) soft-shutdown current ramping. It is during both of these stages of operation that the collector to emitter voltage on the IGBT is relatively high, and therefore the resulting power dissipation is high. Any "unnecessary" IGBT on time in a time-out or soft-shutdown sequence translates to increased heating of the IGBT, which is undesirable.
Comparator C2 is preferably a known PNP comparator which compares the voltage V CEXT to a replica of the higher of the two gate drive output voltages GD1 and GD2. This replica is generated by the voltage follower circuitry composed of transistors QS82, QS84-85, QS87-89, QS96, and QS98-100, as well as resistors RS40-41 and RS43. The NPN current mirror composed of QS82 and QS96 provides a bias current for the follower. The mirror configuration of PNPs QS84 and QS85 constrains the currents through each transistor to be of equal magnitude. Assuming GD1 to be the active gate drive output, the equal currents flowing through transistors QS84 and 85 force the Vbe voltages on QS88 and QS99 to be duplicated in transistors QS87 and QS98. Since the bases of QS88 and QS89 tie directly to the gate drive outputs GD1 and GD2, the highest of those gate drive voltages is translated through the matching Vbe's to the base of QS87, with an approximately 200 millivolt positive voltage offset being provided by the voltage drop across RS43. This drop, which is simply the value of RS43 times one-half of the bias current provided by QS96, guarantees that the voltage adjustment on C EXT leaves V CEXT slightly above the controlling gate drive output voltage. This condition is necessary to insure that the transition from current limiting operation into soft-shutdown does not cause any discontinuities in the gate drive output voltage. The slight positive offset allows the discharging V CEXT to smoothly pass through the existing gate voltage and begin the slow reduction of gate voltage without any abrupt changes thereto.
Referring again to FIG. 2, at the start of a dwell cycle, the signal G7OUT is high, resetting L6 and L5, thereby forcing signal QB5 to a logic high state. With QB5 high, transistor Q5 is turned on, forcing the output of comparator C2 to a logic low state. The logic high state of QB5 also causes transistor Q2 to be turned off.
Once a time out period has elapsed, comparator C1 sets L5, causing the signal QB5 to switch to a logic low state. At this time, V CEXT is higher than the voltage on the active gate drive output (GD1 or GD2) since TOREF is set up to be greater than the gate voltage required on an IGBT to hold the desired range of current limit levels (approximately 3.9 volts on C EXT versus approximately 2.6 volts on the IGBT gate). Therefore, the output of comparator C2 is low even though transistor Q5 is now turned off. L6 is therefore still reset, causing its Q output to be low. With both inputs to NOR gate G10 low, transistor Q2 is thus turned on, beginning a rapid discharge of V CEXT therethrough. This discharge continues until V CEXT drops below the replicated gate drive voltage at the non-inverting input of comparator C2. With V CEXT below the voltage at the non-inverting input of comparator C2, the output of comparator C2 switches high, setting L6, which causes the Q output of L6 to switch to a high state. This high state causes NOR gate G10 to turn off transistor Q2, thereby halting the rapid discharge of V CEXT . At this point, V CEXT has been adjusted from its starting voltage equal to TOREF, down to a few hundred millivolts above the currently active gate drive output voltage. Additionally, switching of the Qbar output of L6 to a low state via the setting of 26 activates follower F1, which couples V CEXT to the active gate drive output.
Referring now to FIG. 7, one preferred embodiment of circuit block C of FIG. 2 is shown. Transistors QS39 and QS40 are connected as a standard PNP differential input pair 230, the collectors of which connect to a current mirror 232 composed of transistors QS42 and QS43. An output transistor QS44 has its base tied to the collector of transistor QS42 and its collector tied to the base of transistor QS40. This is a known configuration for a voltage follower, with an internal compensation capacitor C COMP included across the collector-base terminals of QS44 for loop stability. Transistors QS39-40 and QS42-44, along with C COMP , comprise voltage follower F1 (FIG. 2). Transistor QS91 is connected to the Qbar output of L6 so that when Qbar is high, voltage follower F1 is disabled, and when Qbar is low, transistor QS91 is off, thereby enabling voltage follower F1 to impose a copy of the voltage V CEXT onto the node labeled V F .
The voltage limiter 106 is preferably constructed of the components shown within dash-lined box 106 of FIG. 7. Node V F is connected to one side of an NPN voltage follower 240 composed of transistors QS55 and 56, the emitters of which are connected to a second voltage follower 242 composed of NPN transistor QS57 and NPN transistor QS58. The emitters of QS56 and QS58 are coupled to ground potential through resistor RS27, and are further connected to the bases of transistors Q3 and Q4 (FIG. 2). The emitter of QS57 is connected to resistor RS25, which is connected to resistor RS26, which is further connected to diode-connected transistor QS59. A node connecting RS25 to RS26 is connected to the base of PNP transistor QS36 which forms a standard PNP input stage 250 of comparator C4. Node V F is further connected to an emitter of NPN transistor QSS4 and resistor RS24, the opposite end of which is connected to the base and collector of QS54. QS54 is fed by a current referenced to I R . The voltage V F is translated down one Vbe across the base-emitter junction of QS56, which is subsequently translated back up one Vbe across the base-emitter junction of either Q3 or Q4, forcing the voltage on either GD1 or GD2 to follow the discharging voltage V CEXT .
Transistors QS57-59 and resistors RS25-26 are used to set up the reference voltage CDREF of comparator C4, which is comprised of differential input pair 250 and current mirror 252 connected thereto, with one leg of current mirror 252 driving the base of C4 output transistor QS33. The collector of QS33 is connected to the input of inverter G8. The reference voltage CDREF is set up by the current flowing through QS59 and RS26. However, since the base of transistor QS35 is one Vbe above V CEXT , the effect of QS59's Vbe is approximately canceled so that the true CDREF voltage relative to the CEXT node is approximately the current flowing through QS59 times RS26. Preferably, CDREF is set at approximately 200 millivolts, which may be easily adjusted by changing the value of RS26 while maintaining the same total resistance of RS25 plus RS26. CDREF is intended to be small to force a nearly complete discharge of capacitor C EXT before the next dwell event can begin, as described hereinabove.
The sum of RS25 and RS26 is important in the set up of the voltage limiter circuit 106. The limiter 106 functions by imposing a pseudo-bandgap voltage developed across RS25-26, QS55, QS57, and QS59 in similar fashion to that described for the THLO reference voltage described hereinabove with respect to FIG. 5. The voltage limiting function provided by circuit 106 protects the gate oxide of the IGBTs from excessive voltage conditions. The limiter of voltage reference V F is defined by the equation:
V.sub.F = I.sub.REF *(RS25+RS26)!+Vbe.sub.55 +Vbe.sub.57 +Vbe.sub.59.
The values of RS25 and RS26 can be chosen such that V F is relatively temperature independent. This results in a reference voltage V F which is approximately three times the silicon bandgap voltage, or 3.8 volts. This voltage is transferred to the appropriate gate drive output by translating down one Vbe at QS56, and back up one Vbe at either Q3 or Q4. If the gate drive voltage tries to move above V F , QS58 supplies base drive to Q3 or Q4, causing these transistors to dump excess gate drive current to ground through resistor RS46 (FIG. 8).
Node V F is further connected to resistor RS20, which is connected to an emitter of NPN transistor QS52, the collector of which is connected to NOR gates G3 and G6. The base of QS52 is connected to the base of QS47 and to diode connected QS49. The emitter of QS49 is connected to the base and collector of QS50, and to the base of QS48, the collector of which is connected to the emitter of QS47. The collector of QS47 is fed by a current mirror 260 composed of transistors QS45 and QS46. The base of transistor QS47 is fed by a current generator referenced by I R .
When the voltage at V F is higher than the Vbe voltage of QS50, no current passes through QS52 because the base-emitter junction of QS52 is reverse biased. When the voltage at V F drops below a level defined by Vbe 50 +Vbe 49 -Vbe 52 , which is approximately equal to Vbe 50 , QS52 begins to conduct current, thereby pulling down the collector of QS52. Resistor RS20 limits the amount of current drawn by QSS2. This mechanism provides a comparator threshold for comparator C3 which has a negative temperature coefficient similar to that of typical IGBT gate-emitter threshold voltages, allowing the two to track.
Referring now to FIG. 8, one preferred embodiment of circuit block D of FIG. 2 is shown. It should be noted that only gate drive control1 circuit 30 is shown, although identical circuitry for gate drive control2 circuit 32 is actually connected to the emitter of Q4 as indicated by the arrow extending therefrom. It should also be noted that circuitry 30 is known, and is not considered to be part of the present invention.
At any rate, the emitters of QS56 and QS58 (from FIG. 7) are connected to the bases of transistors Q3 and Q4 respectively. The collectors of Q3 and Q4 are connected together, and are further connected to an emitter of QS93 and to a resistor RS46. QS93 forms a current mirror 270 with transistor QS94, an emitter of which is connected to resistor RS47. The collector of QS93 defines the circuit node DOFF, and is connected to a diode-connected transistor QS97 and to a collector of transistor QS96. The base of QS96 is coupled to resistor RS49 through the Q output of L6. The DOFF node is connected to transistor QD3, which is used as described hereinafter to enable or disable current mirror 280, which is composed of transistors QD2 and QD4. Current mirror 280 is further connected to current mirror 282, composed of transistors QD8 and QD11, the collector of which feeds gate drive GD1.
Assuming again that the gate drive GD1 is the active gate drive output, any excess current available at GD1 is passed through Q3 to the emitter of QS93. By virtue of the mismatch between RS46 and RS47, current mirror 270 normally attempts to sink current from the node labeled DOFF. When excess current from GD1 is shunted to the emitter of QS93, this current develops additional voltage drop across RS46, thereby reducing the amount of current passed through QS93. This action results in excess current at the node labeled DOFF, which turns on transistor QD3. The amount of drive to transistor QD3 is linearized by the presence of diode connected QS97 to reduce the gain at this stage. Under normal IGBT drive, whether charging the gate, ramping the coil current, or current limiting, the drive to GD1 is provided by the sequential current mirrors 280 and 282. The node connected to the collector of QD1 normally sources current for the first current mirror 280, which scales the current and passes it to the second mirror 282, where a second scaling may occur. When a drive signal at DOFF activates QD3, the current available to mirror 282 is reduced, thereby reducing the current to output drive GD1. In this fashion, the amount of current that must be removed from GD1 is reduced, allowing better control of the output voltage during soft-shutdown. This control loop is not allowed to be active until the Qbar output of L6 switches low as previously described.
When Qbar of L6 is high, QS96 holds DOFF in an off state. In current limiting operation, the output current to GD1 is also reduced by the current limit error amplifier 46 (FIG. 1) which connects to gate drive control1 circuit 30 at the collector of QD1 and at the collector base of QD10 as shown in FIG. 8. This limiting is no longer active once the soft-shutdown circuit becomes active and the coil current begins its slow ramp downwardly.
The present invention is illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | An automotive ignition control system includes a vehicle control computer operable to provide electronic spark timing (EST) signals, a control circuit having a number of coil drive circuits connected thereto, a corresponding number of coil driver devices connected to respective ones of the coil drive circuits and a corresponding number of ignition coils connected to respective ones of the coil driver devices. The control circuit is responsive to an active state of any one of the EST signals to activate a corresponding one of the coil driver devices while inhibiting activation of all others. If any EST signal remains in an active state for an excessive time period, the control circuit is operable to lock-out the corresponding coil driver device from operation until such a fault condition is cleared. The control circuit is preferably operable to accomplish the lock-out function by gradually decreasing the coil current associated with the faulty EST signal in a fashion that does not generate a spark event. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 11/128,810 filed on May 13, 2005, and presently issued U.S. Pat. No. ______. The disclosure of the above application is incorporated herein by reference.
FIELD
[0002] The present disclosure relates to steering systems for mobile platforms, and more particularly to a system and method for forming a zero backlash steering tiller.
BACKGROUND
[0003] Various mechanisms may be employed to guide mobile platforms. For example, in a commercial aircraft application, a nose wheel is generally employed to steer the aircraft upon landing. The nose wheel is most typically mechanically coupled to a nose gear. Generally, the nose gear is in turn coupled to a steering mechanism, such as a tiller, in the cockpit for receipt of an input from a pilot. Thus, as the input from the pilot is transferred to the nose gear from the tiller, the nose gear serves to move the nose wheel to guide the aircraft based on the input.
[0004] Generally, most tillers have at least a small degree of backlash which provides undesirable feedback to pilots while steering. This can cause the vehicle to drift off course or provide numerous small inputs to the steering system which can prematurely wear out the system. Accordingly, it is desirable to provide a steering tiller that substantially or completely eliminates the backlash in the steering tiller.
SUMMARY
[0005] In one aspect the present disclosure relates to a method for steering a mobile platform. The method may involve: providing a steering component graspable and rotatable by an operator of the mobile platform from a neutral position to first and second positions; coupling an input shaft to the steering component; coupling an input arm to the input shaft so that rotational movement of the input shaft causes rotational movement of the input arm, the input arm being in the neutral position when the steering component is in the neutral position; supporting an idler arm adjacent the input arm and such that portions of the idler arm and the input arm are in contact when the steering component is in the neutral position; and using a biasing system configured to act on the steering arm and the idler arm to maintain the steering component in the neutral position when no force is being applied by the operator to the steering component, to reduce a backlash generated by at least one of the input arm and the idler arm, but to enable clockwise and counterclockwise motion of the input arm in response to an input from the operator using the steering component.
[0006] In another aspect the present disclosure may involve a method for steering a mobile platform. The method may involve: providing a steering handle graspable and rotatable by an operator of the mobile platform from a neutral position in clockwise and counterclockwise directions to first and second positions; coupling an input shaft to the steering handle; coupling an input arm to the input shaft so that rotational movement of the input shaft causes rotational movement of said input arm, the input arm being in said neutral position when said steering handle is in said neutral position; supporting an idler arm adjacent said input arm and such that portions of said idler arm and said input arm are in contact when said steering handle is in said neutral position; using a pair of springs arranged to provide counteracting biasing forces on said steering arm and said idler arm to maintain said steering handle in said neutral position when no rotational force is being applied by said operator to said steering handle, to reduce a backlash generated by at least one of said input arm and said idler arm, but to still enable clockwise and counterclockwise motion of said input arm in response to a rotational force by the operator on the steering handle.
[0007] In still another aspect the present disclosure relates to a method for steering an aircraft. The method may involve: providing a steering handle graspable and rotatable by an operator of the aircraft from a neutral position in clockwise and counterclockwise directions to first and second positions; coupling an input shaft to the steering handle; coupling an input arm to the input shaft so that rotational movement of the input shaft causes rotational movement of said input arm, the input arm being in said neutral position when said steering handle is in said neutral position; supporting an idler arm adjacent said input arm and such that portions of said idler arm and said input arm are in contact when said steering handle is in said neutral position; using a pair of springs arranged to provide counteracting biasing forces on said steering arm and said idler arm to maintain said steering component in said neutral position when no rotational force is being applied by said operator to said steering handle, to reduce a backlash generated by at least one of said input arm and said idler arm, but to still enable clockwise and counterclockwise motion of said input arm in response to a rotational force by the operator on the steering handle; sensing a rotational position of said input shaft; and using said sensed rotational position of said input shaft to control a steering movement of a wheel assembly of said aircraft.
[0008] The features, functions, and advantages can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0010] FIG. 1 is an environmental view of an aircraft employing the backlash reduction steering tiller according to various embodiments of the present disclosure;
[0011] FIG. 2 is a perspective view of a zero backlash steering tiller according to one embodiment; and
[0012] FIG. 3 is an exploded view of the backlash reduction steering tiller according to various embodiments.
DETAILED DESCRIPTION
[0013] The following description of the various embodiments is merely exemplary in nature and is in no way intended to limit the present disclosure, its application or uses. Although the following description is related generally to a steering system for use in a mobile platform, such as an aircraft, the system could also be potentially implemented in a marine vessel, a train or a land based motor vehicle. Thus, it will be understood that the embodiments described in the present disclosure could be employed in a wide variety of applications. Therefore, it will be understood that the following discussions are not intended to limit the scope of the appended claims.
[0014] With reference to FIG. 1 , a steering system 10 for a mobile platform, such as an aircraft 12 , is illustrated. The steering system 10 operates generally to change the direction of the aircraft 12 . The steering system 10 includes an input mechanism 14 , a portion of which is disposed in a cockpit 16 of the aircraft 12 .
[0015] Referring to FIGS. 2 and 3 , the input mechanism 14 is coupled to an idler 18 . A housing 20 may be disposed about the idler 18 and a portion of the input mechanism 14 . The idler 18 may also be coupled to a steering mechanism 22 .
[0016] The input mechanism 14 includes a user interface, such as a handle 24 , coupled to an input shaft 26 . Although handle 24 is illustrated as forming the graspable steering element, it will be understood that a variety of other mechanisms could be used to interface with an occupant of the cockpit 16 , such as a joystick, lever, knob, or other appropriate mechanism by which an occupant of the cockpit 16 may manipulate a steering element.
[0017] The input shaft 26 includes a first end 28 coupled to the handle 24 , a second end 30 coupled to the steering mechanism 22 and a central portion 32 . The input shaft 26 is generally configured to rotate about a Y-axis upon receipt of an input “R” or “R 2 ” from the occupant applied through the handle 24 . The input shaft 26 further includes an input arm 34 which may be integrally formed in the central portion 32 , or coupled to the central portion 32 through a post processing step, such as welding.
[0018] The input arm 34 is generally circular, but may include a protrusion 36 having a vertically extending branch 38 . The protrusion 36 may be sized to enable the branch 38 to engage the idler 18 . The branch 38 may extend a selected distance “D” above a surface 40 of the input arm 34 to enable the input arm 34 to contact the idler 18 .
[0019] The idler 18 is also preferably generally circular in shape, with a central opening 42 . The central opening 42 is generally sized to enable the idler 18 to be rotatably coupled to the input shaft 26 . The idler 18 is free to rotate on the input shaft 26 , typically using a bearing 41 . The idler 18 could be restrained to prevent movement up or down the input shaft 26 by a collar 43 on the input shaft 26 above the input arm 34 . The idler 18 may further include a neck 44 having a generally T-shaped branch 46 . The neck 44 may be sized to extend a length “L 1 ” from the input shaft 26 , which may typically be equivalent to a length “L 2 ” between the input shaft 26 and branch 38 of the input arm 34 .
[0020] The T-shaped branch 46 may have a first end 48 and a second end 50 . The T-shaped branch 46 may be sized with a length “L 3 ” which is configured to enable the first end 48 of the T-shaped branch 46 to contact the branch 38 of the input arm 34 and the second end 50 of the T-shaped branch 46 to contact the housing 20 as will be described in greater detail below.
[0021] The housing 20 may include a central opening 51 to enable the input shaft 26 to pass therethrough. The housing 20 may also be configured to enclose the idler 18 and input arm 34 of the input mechanism 14 , however, it will be understood that the shape and configuration of the housing 20 may vary for different applications. The housing 20 generally includes a stop 52 formed on an interior surface 54 of the housing 20 . The stop. 52 extends a length L 4 from the interior surface 54 to act as a contact surface for the T-shaped branch 46 of the idler 18 . Thus, the length L 4 of the stop 52 may be any length which is required to inhibit the movement of the idler 18 beyond the stop 52 . The housing 20 further includes two cavities 56 (illustrated in dashed lines for clarity) formed on the interior surface 54 for receipt of a first spring 58 and a second spring 60 . The first spring 58 may be positioned to contact the input arm 34 , and apply a pre-load force to the input arm 34 , while the second spring 60 may be positioned within the housing 20 to contact the idler 18 and apply a pre-load force to the idler 18 . Generally, the first and second springs 58 , 60 are coil springs, however, any suitable biasing member could be employed, such as torsion springs which could apply torque about the input shaft 26 (not shown). The housing 20 may enclose the steering mechanism 22 . The housing 20 provides a means to mount the steering mechanism 22 within the aircraft 12 and keeps foreign objects from jamming the steering mechanism 22 .
[0022] The steering mechanism 22 is coupled to the second end 30 of the input shaft 26 , and may, depending upon the desired configuration, be situated entirely within the housing 20 . The steering mechanism 22 includes a position transducer 62 , a controller 64 and a wheel assembly 66 . It will be understood, however, that the position transducer 62 and controller 64 may be substituted for a mechanical linkage to a mechanical steering system, as is generally known in the art.
[0023] The position transducer 62 is generally coupled to the second end 30 of the input shaft 26 . The position transducer 62 operates to convert the rotational input of the input shaft 26 to a positive or negative electrical signal, depending upon the rotation of the input shaft 26 . For example, the rotation of the input shaft 26 clockwise may generate a positive electrical signal, and the rotation of the input shaft 26 counterclockwise may generate a negative electrical signal, and vice versa, however, any method of electrically distinguishing between the clockwise and counterclockwise direction could be employed. The position transducer 62 is in electrical communication with the controller 64 .
[0024] The controller 64 is in communication with the position transducer 62 and the wheel assembly 66 . The controller 64 is operable to convert the electrical signal received from the position transducer 62 into a desired movement for the wheel assembly 66 , as will be discussed in greater detail below. It will be understood, however, that although the controller 64 is described herein as converting the electrical signal from the position transducer 62 , any appropriate position detecting mechanism could be employed.
[0025] The wheel assembly 66 is in communication with the controller 64 and generally operates to guide the aircraft 12 based on the input received from the controller 64 . The wheel assembly 66 may include at least one wheel 68 , however, two wheels 68 are generally used in large aircraft applications. For example, the wheels 68 typically rotate about an axis 70 which may be supported by a structure 72 . The structure 72 may couple the wheels 68 to a motor 76 . The motor 76 may be in communication with the controller 64 to pivot the wheel assembly 66 to a desired angle a about an axis A based upon the input received from the controller 64 , as will be described in greater detail below. Generally, the angle a to which the wheel assembly 66 rotates is between 65 and 75 degrees. The motor 76 may be any appropriate type of motor which is capable of pivoting the wheel assembly 66 about an axis to enable the aircraft 12 to change direction.
[0026] Referring further to FIG. 2 , in order to guide or steer the aircraft 12 , the operator in the cockpit 16 may apply a force “R” to the handle 24 of the input mechanism 14 . Generally, prior to the application of the force “R” to the handle 24 , the handle 24 is in a standard position, with the first and second springs 58 , 60 each applying a pre-load force “P 1 ” to the input arm 34 and idler 18 , respectively. The force “R” applied by the occupant to the handle 24 will cause the input shaft 26 of the input mechanism 14 to rotate, which in turn causes the input arm 34 of the input shaft 26 to apply a force F 2 against either the first spring 58 or the idler 18 , and which also causes the idler 18 to apply a force “F 3 ” to the second spring 60 , depending upon the direction of the rotation of the input shaft 26 .
[0027] For example, if the operator in the cockpit 16 applies the force R clockwise, the input shaft 26 will rotate clockwise, and the input arm 34 will apply the force “F 2 ” against the first spring 58 . Further, when the input shaft 26 rotates clockwise, the idler 18 is prevented from rotating clockwise due to the stop 52 formed on the interior surface 54 of the housing 20 . Alternatively, if the operator in the cockpit 16 applies the force R counterclockwise, then the input shaft 26 will rotate counterclockwise, causing the branch 38 of the input arm 34 to apply the force “F 1 ” to the T-shaped branch 46 of the idler 18 . The application of the force “F 1 ” from the input arm 34 will in turn cause the idler 18 to apply the force “F 3 ” against the second spring 60 .
[0028] As the input shaft 26 of the input mechanism 14 rotates, the position transducer 62 converts the rotation of the input shaft 26 into the corresponding electrical signal. For example, if the input shaft 26 is rotated clockwise by the occupant of the cockpit 16 , then the position transducer 62 may generate a positive electrical signal which is then transmitted to the controller 64 . Similarly, as an example, if the occupant in the cockpit 16 rotates the input shaft 26 counterclockwise, the position transducer 62 may generate a negative electrical signal which is then communicated to the controller 64 . Then, depending upon the electrical signal generated by the position transducer 62 , the controller 64 may signal the motor 76 to pivot the wheel assembly 66 to a desired angle a about the axis A.
[0029] After the occupant of the cockpit 16 has completed the desired maneuver of the aircraft 12 , the occupant of the cockpit 16 may then rotate the handle 24 to the starting position, while allowing straightforward motion of the aircraft 12 . The use of the first and second springs 58 , 60 ensures that when the input shaft 26 is in the starting position, it will return to the precise starting position with no backslash or slop when the handle 24 is released. This prevents the controller 64 from receiving numerous readings from the position transducer 62 as the first and second springs 58 , 60 prevent small movements of the input shaft 26 when the input shaft 26 is near the starting position. In addition, if the occupant of the cockpit 16 desires to apply a counterforce R 2 in a direction opposite the force R, then it should be noted that the first and second springs 58 , 60 enable the occupant of the cockpit 16 to smoothly transition through the starting position to guide the aircraft 12 in the opposite direction.
[0030] The present disclosure provides a steering mechanism with essentially little or no backlash, and which does not require adjustment, even if the first and second springs 58 , 60 have a loss of pre-load force P 1 . Specifically, the use of the first and second springs 58 , 60 against the input arm 34 and idler 18 serves to remove the backlash from the steering system 10 . The use of the first and second springs 58 , 60 also eliminates the need for adjustment to the steering system 10 to stay at zero backlash. Thus, the steering system 10 essentially forms a self-calibrating system that maintains the handle 24 at a designated “zero” position, while simultaneously removing the backlash that would otherwise be present in a convention steering system.
[0031] While various embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the present disclosure. The examples illustrate the various embodiments and are not intended to limit the present disclosure. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art. | A method is disclosed for steering a mobile platform, where the method may involve: providing a steering component graspable and rotatable by an operator of the mobile platform from a neutral position to first and second positions; coupling an input shaft to the steering component; coupling an input arm to the input shaft so that rotational movement of the input shaft causes rotational movement of the input arm, the input arm being in the neutral position when the steering component is in the neutral position; supporting an idler arm adjacent the input arm and such that portions of the idler arm and the input arm are in contact when the steering component is in the neutral position; and using a biasing system configured to act on the steering arm and the idler arm to maintain the steering component in the neutral position when no force is being applied by the operator to the steering component, to reduce a backlash generated by at least one of the input arm and the idler arm, but to enable clockwise and counterclockwise motion of the input arm in response to an input from the operator using the steering component. | 1 |
This is a divisional application Ser. No. 07/105,290, filed Oct. 7, 1987, now U.S. Pat. No. 4,941,966.
BACKGROUND OF THE INVENTION
Discussion of Background
Depending on the conversion rate and hydrocracking operating conditions (pressure, temperature, gas/oil ratio etc.) and the tendency of the feedstock to produce coke; a catalyst or additive such as activated coke from hard coal or lignite, carbon black (soot), red mud, iron (III) oxide, blast furnace dust, ashes from gasification processes of crude oil mentioned before, natural inorganic minerals containing iron, such as laterite or limonite, amounting to from 0.5 to 15 wt. % of the liquid or liquid/solid feedstock is used in these slurry hydrogenation processes.
EP 0073527, representing one of the latest developments in technology, describes a catalytic treatment of heavy and residue oils in the presence of lignite coke which is mixed with catalytically active metals, preferably with their salts, oxides or sulfides or dust which is produced in the gasification of lignite, in a concentration of between 0.1 and 10 wt. % with respect to the heavy and residue oils. This catalyst or additive is used in the finest distribution with particle sizes of, for example, less than 90-100 microns.
U.S. Pat. No. 3,622,498 also describes a process that teaches that the asphaltene containing hydrocarbonaceous feedstock may be converted by forming a reactive slurry of the asphaltenes--containing the hydrocarbonaceous feedstock, hydrogen and a finely divided catalyst containing at least one metal from the group VB, VIB or VIII and reacting the resulting slurry at 68 bar and 427° C.
U.S. Pat. No. 4,396,495 describes a process for the conversion in slurry reactors of hydrocarbonaceous black oil using a finely divided, unsupported metal catalyst like vanadium sulfide with a particle size of between 0.1 and 2000 microns, a preferred range of 0.1 to 100 microns, where an antifoaming agent based on silicone is also fed to the conversion zone to reduce the foam formation that is produced at the conditions where the reaction takes place (temperature up to 510° C., pressure of about 204 bar and catalyst concentration of about 0.1 wt. % to 10 wt. %). This method is not adequate for temperatures higher than about 430° C.; due to the decomposition of the silicone as this loses its activity, also the silicone agent remains in the low boiling point fractions producing difficulties in the upstream processing.
Canadian 1,117,887 describes a hydrocracking process for the conversion of heavy oils to light products where high pressure and temperature are employed. The heavy oil is put in contact with a catalyst which is finely divided coal carrying at least one metal of group IVA or VIII of the periodic table where the coal is a subbituminous coal having a particle size of less than 100 mesh (<149 microns).
U.S. Pat. No. 4,591,426 which also describes a process of hydroconversion of heavy crudes with at least 200 ppm metal content using natural inorganic materials as a catalyst such as laterite or limonite which have a particle size of between 10 and 1000 microns at temperatures higher than 400° C. and total hydrogen pressure of 102 bar.
When the reactor zone is a moving bed-reactor, feeding an amount of 1.0 to 15 wt. % based on the feedstock where the reactants in said reaction zone are between 20 wt. % and 80 wt. % and a particle size of between 1270 and 12700 microns is employed.
Those skilled in the art of hydrocarbon processing have not recognized that under conditions which are normally used in catalytic slurry reactors of the bubble column type, using inexpensive catalysts or additives like these previously described may produce foam, which reduces the amount of liquid in the reaction zone when higher gas velocities of more than 3 cm/sec are employed. These higher gas velocities are also employed in industrial reactors.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a process for upgrading heavy and residual oils which does not result in excess foam formation.
Another object of the invention is to provide a process which fully utilizes the reaction zone of the hydrogenation reactor.
These and other objects which will become apparent from the following specification have been achieved by the present process for the hydrogenation of heavy oils, residual oils, waste oils, shale oils, used oils, tar sand oils and mixtures thereof, which comprises the steps of:
i) contacting said oil with 0.5-15 wt. % of an additive to produce a slurry, said additive being selected from the group consisting of red mud, iron oxides, iron ores, hard coals, lignites, cokes from hard coals, lignites impregnated with heavy metal salts, carbon black, soots from gasifiers, and cokes produced from hydrogenation and virgin residues, and
ii) hydrogenating said slurry with hydrogen at a partial hydrogen pressure of between 50-300 bar, a temperature between 250°-500° C., a space velocity of 0.1-5 T/m 3 h and a gas/liquid ratio between 100-10000 Nm 3 /T,
wherein said additive comprises particles having a particle size distribution between 0.1 and 2,000 microns, with 10-40 wt. % of said particles having a particle size greater than 100 microns.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 describes the hydroconversion process of the present invention with additional distillation and hydrodesulfurization procedures;
FIG. 2 shows the log (-log) versus log plot of the wt. % versus size for two normal size distributions after a milling operation;
FIG. 3 shows a log (-log) versus log plot for wt. % versus size for two normal size distributions and for mixtures thereof; and
FIG. 4 shows a graph illustrating the effect of large particles on the rate of pressure increase in the pressure head of the first reactor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a process for upgrading heavy oils derived from any source such as petroleum, shale oil, tar sand, etc. These heavy oils have high metal, asphalt and conradson carbon contents. Typical metal concentrations (vanadium and nickel) are higher than 200 ppm, asphaltenes higher than 2 wt. %, conradson carbon is greater than 5%, and more than 50 wt. % of the residue fraction boils at a temperature of more than 500° C.
It is for the first time here disclosed that from the fluiddynamic point of view, for a given gas velocity larger particles inside the reactors help to increase the amount of liquid where the hydrocracking reaction takes place.
The present invention achieves the full utilization of the reaction zone employing two independent feeding systems of two catalyst or additive streams, where two different catalyst particle sizes are employed.
Accordingly, in one embodiment, the invention comprises a process for the conversion of heavy crudes with a density of less than 20° API, more than 200 ppm metals and more than 5 wt. % conradson carbon by contacting the feedstock in the reaction zone with hydrogen and a catalyst or additive in an upflow co-current three-phase bubble column reactor.
The catalyst may be any metal of the group VB, or VIB or VIII alone or any porous support on which metals available as organometallic species in the heavy crude can deposit.
It has been found that larger particles in the particle size range of 100 microns or more, are able to diminish the amount of foam formed inside the reactors, for gas velocities in use in commercial scale reactions (3 cm/s and more) when added in a proportion not less than 0.1 wt. %, preferably 0.5 wt. %, over the heavy oil fed to the hydrocracker. The significance of the present invention is due to the fact that when foam inside the reactors is reduced, the liquid phase reaction volume is increased, which allows one to achieve the desired conversion of 500° C. + residue into distillates at a moderate temperature level.
Also, the present invention has uncovered the fact that to achieve very high conversion (90% or more) of 500° C. + residues, at reasonably high space velocities 0.5 t/m 3 .h or more) a considerable fraction of small particles (less than 50 microns), is required because here it has been discovered that this brings considerable benefit to the hydrogenation capacity of the catalyst system being added.
Even though thermodynamic, fluiddynamic and kinetic relationships in the upflow slurry hydrogenation reactors together with the addition of additives or catalysts have so far not been totally clarified, it is believed that a certain amount of a larger particle fraction (which depends on the fluiddynamic conditions), decreases the foam formation or the gas retention, increasing the amount of liquid at the expense of the gas portion inside the reactor as is expressed by the reactor pressure head, residue conversion rate and preheating temperature. This phenomenon is detected when the gas velocity in the reactor is higher than 3 cm/sec and the temperature higher than 250° C. with a pressure range between 50 bar and 300 bar. A practical measure of the hydrogenation capacity of the catalyst system being employed is the ratio (X A /X R ), where X A is asphaltene conversion (DIN method 51525), and X R is the vacuum residue 500° C. conversion, which for best conditions to avoid asphaltene precipitation and further coke deposition should be near unity. Here it has been demonstrated that the (X A /X R ) ratio is nearer to unity when a weight % of not less than 1 wt. % above the heavy oil feed, of the smaller particles (less than 50 microns) is employed for high residue conversions (X R ≧87% conversion).
These facts have led for the first time to the instrumentation of a dual feeding system for adding the most desired particle size distribution for the optimum use of a hydrocracker reactor of the bubble column type.
Two different and independent feeding systems are used to provide the system with the necessary fluiddynamic requirements and to maximize the liquid content inside the reaction zone. One of these feeding systems is employed to feed the high activity catalyst fraction with a particle size below 100 microns with a more preferred particle size below 50 microns and the second feeding system is employed to feed a less active catalyst or inert material with a particle size in the range of 100 microns to 2000 microns, most preferred is the range of 700 microns to 7000 microns.
The preferred catalyst mixture, formed by the additive of the two different catalyst particle size distributions can also be made beforehand in other separate devices, employing only one feeding system to contact the catalyst or additive with the oil. The remarkable feature of the present invention is that two different particle size distributions of the catalyst or additive of the same or of different chemical species are used in the reacting system.
The process of this invention comprises a hydroconversion in which a heavy oil feedstock is contacted with hydrogen and a catalyst or additive like activated coke or lignite carbon black (soot), red mud, iron (III) oxide, blast furnace dust, ashes from gasification processes of heavy oil, natural inorganic minerals containing iron such as limonite or laterite, amounting to from 0.5 wt. % to 15 wt. % related to the liquid. Where these catalysts or additives are fed to be mixed with the heavy crude employing two different and independent feeding systems, one feeding system is employed to feed the most active catalyst which is characterized by a small particle size which is preferred to be less than 100 microns. The second feeding system is employed to feed the catalyst fraction that helps the fluiddynamic behaviour of the liquid phase reaction system increasing the amount of liquid inside the reactor where the critical characteristic of this fraction is the particles size which should be between 100 microns and 2000 microns, with a size between 700 and 7000 microns being most preferred.
The proportion of the larger particles is to be between 5 and 80 wt. %, preferably 10 to 30 wt. % based on the total amount of the catalyst or additive.
Referring to FIG. 1, the fine catalyst (1) with a particle size of less than 100 microns--preferably less than 50 microns--is stored in the fine catalyst silo (2) and is fed discontinuously through valve (3) to a small weighted vessel (4) that feeds to a continuous screw feeder (5) at the appropriate fine catalyst or additive rate and is mixed with the heavy oil (16) and larger catalyst (12) in the mixing tank (13) at a fine catalyst concentration of 0.5 to 6 wt. % with a most preferred range of 0.5 to 3 wt. %.
The second feeding system is employed to feed the one-way catalyst or additive having a larger particle size which, according to this invention, should range from 100 microns to 2000 microns with a most preferred range of 700 to 7000 microns. The larger catalyst or additive (7) is stored in the larger catalyst silo (8) and is fed discontinuously through a valve (9) to a small weighted vessel (10) that feeds to a continuous screw feeder (11) at the appropriate larger catalyst or additive rate and is mixed with the heavy oil (16) and the fine catalyst or additive (6) in the mixing tank (13) at a catalyst concentration of the larger particle size based on the heavy oil of 0.5 to 13%, more preferably between 0.5 and 6.0%. The two feeding systems that are described here are not limited to this invention, other methods for feeding these two catalyst streams can be employed.
The heavy oil, fine and larger catalyst or additive in the mixing vessel (13) exits the same through line (14) and is then pumped to the operating pressure using a slurry high pressure pump (15). The fresh hydrogen (61) and the recycle gas (59) are preheated in the gas preheater (63) to a temperature of between 200° C. and 500° C. and are added to the residue oil (50') that was previously preheated in the heat recovery exchangers (49, 50) to make use of the heat of reaction of the products and is then fed to the feed preheater train (18) to reach the necessary outlet temperature to maintain the temperature in the reactor system.
The reactor system consists of 1, 2, 3 or more serially connected reactors. Preferred are 1 to 3 reactors serially connected. The reactors (20, 24, 27) are tubular reactors vertically placed with or without internals where the liquid, solid and gas are going upstream. This is where conversion takes place under temperatures of between 250°-500° C., preferably 400° and 490° C., more preferably temperatures of between 430° and 480° C., a hydrogen partial pressure of between 50 and 300 bar, and a recycle gas ratio of between 100 Nm 3 /T and 10000 Nm 3 /T. By means of cold gas feeding (21, 23, 26), an almost isothermal operation of the reactors is possible.
In secondary hot separators, operated at almost the same temperature level as the reactors, the non-converted share of the used heavy and residual oils as well as the solid matter are separated from the reaction products which are gaseous under the processing conditions. The liquid product of the hot separators is cooled in a multi-step flash unit. In the case of a combined operation of liquid and gaseous phase, the overhead fraction of the hot separators, the flash distillates, as well as possible coprocessed crude oil distillate fractions are combined and added to the secondary gaseous phase reactors. Under the same total pressure as in the liquid phase, there is a hydrotreating or even a mild hydrocracking on a catalytic fixed bed under trickle-flow conditions.
After intensive cooling and condensation, gas and liquid are separated in a high-pressure cold separator. The liquid product is cooled and can then be further processed by usual refinery procedures.
From the process gas, the gaseous reaction products (C 1-4 gases, H 2 S, NH 3 ) are separated to a large extent, and the remaining hydrogen is returned as circulation gas.
According to the present invention, two or three separated and independent feeding systems are used where fine catalyst with a particle size of less than 100 microns is fed using one feeding system and the larger catalyst with a particle size of between 100 and 2000 microns using the second feeding system, maintaining a proportion of larger catalyst particle size with respect to the total catalyst of between 5 and 80%, preferably between 5 and 30%, where the total amount of catalyst or additive based on the heavy crude is between 0.5 and 15 wt. %. We have observed that the amount of solids inside the reactor can be controlled and as a consequence the amount of liquid inside the reactor can be optimized increasing the conversion of the heavy crude in the reaction system and diminishing the preheating temperature that reduces the investment and operating costs of the feed preheating train.
We have also observed that this invention is particularly important when the gas velocity in the reactor at reaction conditions is higher than 3 cm/sec based on the transverse area of the reactor defined by its diameter, which is the gas velocity that normally is employed in industrial reactors.
We have observed that when the gas velocity in the reactor is higher than 3 cm/sec and big particles are not employed, the amount of liquid is very low reflected by its lower head pressure, lower conversion and higher preheating temperatures. Also, when the amount of big particles is very high, these big particles have a tendency to accumulate in the reactor with the course of time, decreasing the amount of liquid in the reactor and the on-stream factor of the reaction system.
It is generally preferred to add the same additive or catalyst as both fine and larger particle fractions. But it is also possible, and in some cases even advantageous, to use additives of a different composition for fine and larger particle fractions, e.g. Fe 2 O 3 as the fine particle proportion with an upper limit of the particle size of 30 microns and lignite activated coke with a lower limit of the particle size of 100 microns.
It must be recognized that two feeding systems are not necessary to feed Tank No. 6 (FIG. 1), which is the catalyst/oil mixing tank, but that a catalyst mixture, formed by the addition of the two different catalyst particle distributions could be made beforehand in another separate device, and the catalyst mixture fed directly to vessel No. 6 (FIG. 1). The remarkable feature of the present invention is that two distinguishable particle size distributions of catalyst or additives of the same or different chemical species, are used in the reacting system.
This mixing of the two catalyst size distributions could be part of the emergency system, this also being included in the scope of the present invention.
TABLE 1______________________________________Weight vs. particle size distribution for anormal sample after milling operation (Sample A) Sample A Sample Ad.sub.(μ) wt. % between d.sub.(μ) wt. % under d.sub.(μ)______________________________________ >500 0500/315 1.4 1.4315/200 26.1 27.5200/125 16.5 44.0125/90 11.7 55.790/69 11.9 67.663/45 10.9 78.545/32 6.5 85.027/21 4.0 89.021/15 3.0 92.015/10 3.0 95.010/7 2.0 97.07/5 2.2 99.2 5/2.5 0.8 100.02.5/1.5 -- --1.5/0.5 -- -- <0.5 -- --______________________________________
TABLE 2______________________________________Weight vs. particle size distribution for anormal sample after milling operation (Sample B) Sample B Sample Bd.sub.(μ) wt. % between d.sub.(μ) wt. % under d.sub.(μ)______________________________________ >500500/315315/200200/125125/9090/6963/4545/3227/21 3.3 3.321/15 5.3 8.615/10 12.2 20.810/7 12.0 32.87/5 4.0 36.8 5/2.5 24.5 61.32.5/1.5 15.0 76.31.5/0.5 18.0 94.3 <0.5 5.7 100.0______________________________________
TABLE 3______________________________________Weight vs. particle size distributionfor two normal samples after millingoperation and for A 50% A/50% B mixture(Sample C) yield underwt. % between d.sub.(μ) d.sub.(μ) wt. %d.sub.(μ) Sample A Sample B Sample C Sample C______________________________________ >500 0500/315 1.4 0.7 0.7315/200 26.1 13.0 13.7200/125 16.5 8.3 22.0125/90 11.7 5.9 27.990/69 11.9 6.0 33.963/45 10.9 5.5 39.445/32 6.5 3.2 42.627/21 4.0 3.3 3.2 45.821/15 3.0 5.3 4.2 50.015/10 3.0 12.2 7.7 57.710/7 2.0 12.0 7.0 64.77/5 2.2 4.0 3.1 67.8 5/2.5 0.8 24.5 12.7 80.52.5/1.5 15.0 7.5 88.01.5/0.5 18.0 9.0 97.0 <0.5 5.7 2.9 99.9______________________________________
TABLE 4______________________________________Weight vs. particle size distribution fortwo normal samples for a 30% A/70% B mixture(Sample D) yield underwt. % between D.sub.(μ) 30% A/70% B d.sub.(μ) wt. %d.sub.(μ) Sample A Sample B Sample D Sample D______________________________________ >500 0 0500/315 1.4 0.42 0.42315/200 26.1 7.83 8.25200/125 16.5 4.95 13.20125/90 11.7 3.51 16.7190/69 11.9 3.57 20.2863/45 10.9 3.27 23.5545/32 6.5 1.95 25.5027/21 4.0 3.3 3.51 29.0121/15 3.0 5.3 4.61 33.6215/10 3.0 12.2 9.44 43.0610/7 2.0 12.0 9.00 52.067/5 2.2 4.0 3.46 55.50 5/2.5 0.8 24.5 17.39 72.912.5/1.5 15.0 10.5 83.401.5/0.5 18.0 12.6 96.00 <0.5 5.7 4.0 100.00______________________________________
TABLE 5______________________________________Weight vs. particle size distribution fortwo normal samples for a 10% A/90% B mixture(Sample E) yield underwt. % between d.sub.(μ) 10% A/90% B d.sub.(μ) wt. %d.sub.(μ) Sample A Sample B Sample E Sample E______________________________________ >500 0 0.14500/315 1.4 2.61 0.14315/200 26.1 1.65 2.75200/125 16.5 1.17 4.40125/90 11.7 1.19 5.5790/69 11.9 1.09 6.7663/45 10.9 0.65 7.8545/32 6.5 3.37 8.5027/21 4.0 3.3 5.07 11.9021/15 3.0 5.3 11.30 16.9415/10 3.0 12.2 11.00 28.3010/7 2.0 12.0 3.88 39.207/5 2.2 4.0 22.13 43.12 5/2.5 0.8 24.5 13.50 65.252.5/1.5 15.0 16.20 78.751.5/0.5 18.0 5.10 94.95 <0.5 5.7 100.00______________________________________
In Tables 1 and 2 are presented the accumulative weight distributions of the samples A and B (larger and smaller particles respectively) which are each produced in a specific milling operation.
The accumulative weight distribution of the samples A and B in Tables 1 and 2 are plotted on a log (-log) versus log graph (FIG. 2), and this graph shows that samples A and B are very nearly represented in this plot by straight lines in the range of an accumulative weight between 1 and 99%. This is coincidental with what is well known for samples produced in a straight-forward one-pass or with recycle milling operation in which a target yield under a predeterminated sieve size is given (Robert Perry, Chemical Engineers Handbook, Ed. 5, Sect. 8 "Size Reduction").
The use of closed-circuit grinding in which mill discharge is classified and the coarse material is returned to the mill is considered to be different than the present invention. This conventional procedure is not a mixing of separate catalyst streams of different sizes because in closed-circuit grinding, the target is also to obtain a certain yield under a predeterminate sieve size.
In FIG. 3 are plotted the mixtures of the samples A and B which are sample C (50% A/50% B), Table 3, sample D (30% A/70% B), Table 4 and sample E (10% A/90% B), Table 5, and it is observed that these mixtures give a curve which cannot be represented by a straight line.
A mixture of two or more streams coming out from two or more separate milling operations with a certain yield under a predeterminated sieve size, differs widely from the straight line behavior given by eq.(2):
% η/100=exp [-a dp.sup.b ] (1)
1n (-1n [% η/100])=1na+b 1n dp (2)
where:
% η: Accumulative weight under a dp, wt %
dp : particle size, microns
This provides a way to identify when a mixture of two or more particle size distributions of widely different particle sizes is being fed to the hydrocracking reactor, this being the essence of present invention. In Table 6 are presented the results of the linear regression by the mean-square fit of equation (2) and the correlation coefficient R 2 calculated by the equation (3) (Edwin L. Crow, STATISTICS MANUAL, p. 164). ##EQU2## where n: number of experimental points
y: 1n [-1n (η/100)]
x: 1n (dp)
It can be observed that the particle size distributions of sample A and sample B which are samples of a milling operation can be represented by a straight line with a correlation coefficient R 2 higher than 0.96 (R 2 >0.96). Sample C, Sample D and Sample E are mixtures of Sample A and Sample B. When one tries to represent these mixtures as a straight line, the correlation coefficients (R 2 ) of these regressions are lower than 0.96 (R 2 <0.96). This indicates that these samples cannot be well represented by a straight line. Based on this fact, the present invention covers situations in which
a) two or more separate catalyst feeding devices add distinguishable catalyst particle size distributions to the hydrocracking section, and
b) only one catalyst stream is added to the hydrocracking section the correlation coefficient of eq. 2 fails the test of R 2 ≦0.96 when mean-square fit is made for the full range of the size distribution (1%≦dp≦99%).
Both situations a) and b) are analogous because the important feature of this invention is that for the first time it has been found that only a catalyst mixture which has R 2 ≦0.96 is able to simultaneously eliminate foam from hydrocracking reactors of the bubble column type and also to minimize the amount of added catalyst. As noted above, the mixture of two (or more) original milling size distributions allows one to minimize the catalyst addition to the hydrocracking reactor. This is because it has been demonstrated that the smallest particles are best suited to control polymerization reactions giving rise to coke formation. Coke formation is at its minimum when a larger proportion of fines is added, for a certain fixed percentage of total catalyst in the feed. Also, a certain amount of larger particle size catalyst has been demonstrated to be required to eliminate foam from the bubble column hydrocracking reactor. To minimize the total amount of catalyst added, it is required then to work at the minimum amount of larger particle catalyst. This can be mathematically stated as follows:
TABLE 6__________________________________________________________________________Results of mean-square fit linear regressionof samples A, B, C, D, and ESAMPLE A B C D E__________________________________________________________________________Type of sample milling milling mixture mixture mixture product product 50% A/50% B 30% A/70% B 10% A/90% BRegressioncoefficientsin eq. (2)*LN a -6.23 -1.868 -2.327 -1.906 -1.5642 .sup. b 1.279 1.044 0.627 0.606 0.628Correlation 0.974 0.986 0.933 0.912 0.899coefficient R.sup.2__________________________________________________________________________ *Equation (2) ln (- ln % η/100) = lna + bln dp In general: (wt. %) = wt. %.sub.big + wt. %.sub.fine but to minimize wt. % added, wt. % = (wt. %.sub.big).sub.min + (wt. %.sub.fine)
Catalyst addition can be minimized by adding just the minimum amount of the larger particle catalyst, i.e., just enough to eliminate foam formation. Two catalyst addition systems provide more flexibility to reduce the total amount of catalyst being added. Once foam formation has been controlled, the two catalyst addition systems allow one to substitute the larger particle catalyst by fine material. Since the latter is able to reduce coke formation, this in turn allows for further catalyst reduction, now of the fine catalyst, thereby minimizing the total amount of catalyst being fed to the hydrocracking reactor.
As the larger particle fraction preferably concentrates in the liquid phase reactor system, it is in many cases possible to reduce the proportion of the larger particle fraction from the amount present during the start-up phase, for example 20% by weight or more, to approximately 5% by weight or less during the operating phase. This can be accomplished by adding the fine particle size fraction without further addition of the larger particle size fraction.
In general, this same additive is used as the fine and as the larger particle size fraction. However, it is possible and in many cases advantageous to use different combinations for the fine and larger particle size fractions. For example, one may use Fe 2 O 3 as the fine particle fraction with a maximum particle size of 30 microns and brown coal active coke with a minimum particle size of 120 microns as the larger particle size fraction.
The known impregnation of catalyst carriers with salts of metals, for example, molybdenum, cobalt, tungsten, nickel and particularly iron, can also be used in the present process. The impregnation may be performed by known methods such as neutralization of these salts or their aqueous solutions with sodium hydroxide. It is possible to impregnate both the fine particle fraction and the larger particle fraction with the metal salt solutions noted above or, alternatively, only one of the fractions may be impregnated.
A most preferred procedure then, is to feed two separate feed streams, the smaller particles and the larger particles, for the reasons stated above. In cases where a mixture is prepared before being added to the feed tank, i.e. in a separate silo, and then mixed as a solid powdery mixture, the flexibility inherent to the dual feeding system of addition is diminished when the mixture of "larger" and "smaller" particles are pre-prepared so as to feed only one stream of solid particles to the feed tank (6), although improved conditions result as can be recognized by the low value of the correlation index R 2 (R 2 ≦0.96).
It must also be stated that the minimization of catalyst addition to the hydrocracking reactor brings a very important advantage, not only the already indicated lower operating costs because of the use of less catalyst but also due to the fact that when smaller amounts of larger particles are added to control foam formation, less catalyst sediments in the reactor volume which consequently rises to higher conversion, for the same conditions (T, space velocity, etc.) This allows one to reduce the required reactor temperature for a predetermined conversion level which is very convenient for the whole hydrocracking operation because a lower temperature level results in less gas production and hydrogen consumption, very relevant variables for a economical operation.
This invention can also be applied to the hydrogenation of mixtures of heavy oils, residual oils, waste oils with a ground portion of lignite and/or hard coal, where the oil/coal weight ratio is preferably between 5:1 and 1:1. Coal can be used which has a corresponding proportion of larger particle fractions of 100 μm and more.
The hydrocracked products after the reaction system (28) are sent to the first of the two hot separator vessels (29) to separate the gas/vapor phase from the heavy liquid product which contains the non-converted residue and the spent catalyst or additive. The temperature of the hot separator is controlled in the range of 300° C. and 450° C. by regulation of the quench gas (32, 34) injected into the bottom of each hot separator (29, 33). The second hot separator (33) serves mainly as a guard vessel for the gas phase reactors (40, 46).
In case of the combined operation hydrocracking (LPH) reactors (20, 24, 27) and the gas phase reactors (GPH reactors) (40, 46), the top product of the second hot separator (36) the flash distillates (77) as well as crude oil distillates (36'), which have to be processed at the same time, are combined and fed to the gas phase reactors (40, 46) at the same total pressure as in the LPH reactors and at a similar temperature. The range of operating conditions in these reactors according to the invention are a pressure range between 50 and 300 bar, temperatures between 300° C. and 450° C. and a gas/liquid ratio between 50 and 10000 Nm 3 /T. These reaction zones are conventional and are essentially a fixed bed reaction zone under trickle-flow conditions containing a conventional hydrosulfurization catalyst, or a mild hydrocracking catalyst such as group VIb or group VIII metal on a alumina support.
Effluents (48) from reaction zone (47) are intensively cooled and condensed (49, 50), preheating the fresh feed (15') to recover the heat of reaction. Gas and liquid are separated in a high pressure cold separator (52). The liquid product is depressurized and can subsequently be processed in a standard refinery.
After the cold separator (52), the gaseous reaction products are separated from the process gas (56) as far as possible. The remaining hydrogen (57) is compressed by the recycle gas compressor (58) and is recycled to the process (59). The bottom stream (32, 34) from the hot separators (29, 33) is depressurized in a multistage flash unit (65, 72) and the residue and used catalyst (73) or additive are sent to the refinery for further treatment such as low temperature carbonization processes or solids separation processes. The head product 71 from flash unit 72 is separated once more in column 75 into a gaseous component (surplus gas) and a liquid component 76 which leaves unit 75 through its bottom and is conveyed through line 77 as a flash distillate. This material is combined with crude oil distillates and the combined material passes into gas phase reactor 40.
Other features of the invention will become apparent in the course of the following descriptions of the exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.
EXAMPLES
Example 1
A vertical bubble column reactor without any internals and in which the temperature is regulated by the outlet temperature of a preheater system as well as by a cold gas system, is operated with the a specific weight rate (space velocity) of 1.5 T/m 3 h with the vacuum residue of a conventional residue oil of Venezuela at a hydrogen partial pressure of 190 bar, a H 2 /liquid ratio of 2000 Nm 3 /T and a gas velocity of 6 cm/sec. Under these conditions, 2 wt. % of lignite coke with a strict upper limit for the particle size of 90 μm are added to the residue by a conventional feeding system. Subject to these operating conditions, the preheater outlet temperature of 447° C. was necessary to maintain a temperature of 455° C. inside the reactor. The differential pressure of the reactor under these conditions is approximately 100 mbar, and the residue conversion is approximately 45%.
The plant was then run with two different feeding systems; one adding 1.4 wt. % (on feed) of lignite coke all under 50 micron; the second feeding system adding 0.6 wt. % (on feed) of lignite coke with a particle size of more than 150 microns and less than 600 microns, for a total of 2 wt. %. The pressure head of the reactor increased from 100 mbar to approximately 300 mbar and the preheating outlet temperature decreased from 447° C. to 438° C. At the same time, the residue conversion rate (RU) increased from 45% to 62%.
The conversion is estimated as follows: ##EQU3##
Example 2
In a continually operated hydrogenation plant with three serially connected vertical slurry phase reactors without any internals, the vacuum residue of a Venezuelan heavy oil was converted with 2 wt. % Fe 2 O 3 with a strict upper limit of particle size of 30 microns with 1.5 m 3 H 2 per kg residue, 6 cm/sec gas velocity, and a hydrogen partial pressure of 150 bar. In order to reach a residue conversion rate of 90%, the three serially connected slurry phase reactors were adjusted to an average temperature of 461° C. The space velocity was 0.5 kg/1h of reactor volume.
When 25% of the additive used was exchanged using a second feeding system with a screening fraction of Fe 2 O 3 with a particle size distribution between 90 and 130 microns, the differential pressure in the reactors rose from 70 mbar to 400 mbar. At a constant conversion rate of 90%, the reactor temperature became 455° C. At a space velocity of 0.75 kg/1h, a residue conversion of 78% was reached with an average reactor temperature of 455° C., and a residue conversion of 90% with an average reactor temperature of 461° C.
In the following table these points are summarized:
__________________________________________________________________________ Space Average ConversionAdditive Velocity temperature temperatureSample2 wt. % Fe.sub.2 O.sub.3 (kg/lh) (°C.) (%)__________________________________________________________________________A 100 wt. % 30 μm 0.5 461 90B 75 wt. % 30 μm 0.5 455 90 25 wt. % 90-130 μmC as in B 0.75 455 78D as in B 0.75 461 90__________________________________________________________________________
With the use of two additive mixtures which are different with regard to their particle size ranges, an increase of 50% in space velocity in the bottom phase reactors (specific weight rate) is possible, employing the same reaction temperature level.
Example 3
In order to demonstrate the effect of the two separated and independent feeding systems, a test was conducted feeding a lignite coke additive employing only one feeding system. This additive had 30 wt. % of a particle size larger than 100 microns and less than 500 microns.
Employing this particles size distribution and a Venezuelan heavy crude, a test of 826 hours was conducted in a three slurry reactor system, operating at approximately 460° C. average reactor temperature, pressure of 260 bar to 205 bar, 2% to 3% catalyst based on the residue feed, gas/liquid ratio of between 1800 to 2700 Nm 3 /T and a gas velocity of approximately 6 cm/sec. In Table 7 the results are presented and it can be seen that the reactor differential pressure in the first reactor slowly but continuously increased during the course of time, due to solids accumulation. The increase of the differential pressure could not be reduced, either, when the amount of catalyst was reduced from 3 to 2%. As a consequence, a slow decrease of the conversion rate was observed with time due to solids filling the reaction volume reducing the effective reaction volume for the hydrocracking reactor. These results show that by this feeding-system method, after some time the reactor is filled with solids. A large reaction volume is lost, reducing the conversion in the reactor system, and making this method unsuitable as an industrial operation.
TABLE 7__________________________________________________________________________EXPERIMENTAL INFORMATIONPRESSURE DROP IN REACTOR DC-1310Feed: Venezuelan heavy crude(Gas velocity approx. 6 cm/sec)Pressure from 260 bar to 205 barGas/liquid ratio between 1.800 Nm.sup.3 T and 2.700 Nm.sup.3 /T__________________________________________________________________________Average reactor 460 460 460 460 460 460 460 460 461temperature, °C.wt. % additive* 3 3 3 3 3 3 3 2 2Residue 94.0 94.0 93.0 94.0 92.0 89.0 93.0 93.0 79.0conversion, wt. %Diff. P (PDRA 13009), 305 305 320 330 325 330 360 355 405mm bar first reactorHours in operations 52 61 111 204 279 321 699 783 826__________________________________________________________________________ *additive with 30% of particle size between 100 and 500 microns
On the other hand when the two separate and independent feeding systems of this invention were employed, it was observed that the pressure head in the reactor could be controlled (FIG. 4), increasing or decreasing it depending on the amount of big particles (50-200 microns with 70%>100 microns) employed. When the catalyst particles were fed using two separate and independent feeding systems, one for the small particles of less than 30 microns and the other for big particles 50-200 microns, the behaviour of the pressure head in the reactors was completely stable in spite of maintaining them completely filled with the slurry phase.
The pressure head increased at a rate of 5 mbar/h when 2 wt. % of larger particles (50-200 microns with 70%>100 microns) and 2% of fine particles (less than 30 microns) were employed; when the larger particle feeding system was stopped, the pressure head decreased at a rate of -7 mbar/h, maintaining a 4% catalyst only with small particles. This test was conducted at 140 bar total pressure, 1500 Nm 3 /T gas/liquid ratio and 6 cm/sec gas velocity. This example clearly shows the advantage of employing the two feeding systems to limiting the amount of solids inside the reactor and as a consequence the amount of liquid inside it, thus permitting an effective control over conversion and preheater outlet temperature.
Example 4
A natural mineral containing Fe 2 O 3 catalyst with less than 20 microns particle size was fed using one of two feeding systems. The second one was employed to feed larger particles with particle size of less than 300 microns with 50 wt. % content of particles smaller than 100 microns.
This dual catalyst stream was fed in a total amount of 3.1% based on heavy oil feed to the reaction system. The heavy oil employed was Morichal vacuum residue. The total pressure employed in the test was 170 bar with 130 bar hydrogen partial pressure, 7.8 cm/sec gas velocity in the reactor system, 1700 Nm 3 /T recycle gas; an average reaction temperature of 464° C. and a specific throughout (space velocity) of 0.7 T/m 3 h (Table 8).
With these operating conditions with 1.1 wt. % based on crude of fine particles (less than 20 microns) in one feeding system, with 2.0 wt. % based on crude of larger particles (less than 300 microns containing 50 wt. % of the catalyst having a particle size of less than 100 microns), in the second feeding system, the residue conversion was 92.0% and the asphaltene conversion was 90.0% with a coke production of 1.2% (Test 1, Table 8).
When with the same operating conditions the amount of small particles (less than 30 microns) using one feeding system was reduced to 0.6% and the amount of bigger particles (less than 300 microns with 50 wt. % less than 100 microns) in the second feeding system was increased to 2.5% based on the crude, maintaining a constant total 3.1% catalyst, the crude conversion was maintained at 92%, but the asphaltene conversion decreased to 65% and the coke yield increased to 2.5% giving plugging problems in the hot separator (Test 2, Table 8).
TABLE 8__________________________________________________________________________Effect of the two particle size distribution on thetotal amount of catalyst and plant operability__________________________________________________________________________Pressure: 170 barH.sub.2 partial pressure: 130 barGas velocity: 7.8 cm/sec.Gas/Liquid Ratio: 1.700 Nm.sup.3 /hAver. Reactor Temperature: 464° C.Space Velocity: 0.7 T/m.sup.3 h__________________________________________________________________________ % smaller % longer % total residue coke particles particles amount of conv. asphaltenes prod. pilot plantTest 20 μm 300 μm catalyst 500° C.+ conv. % % operability__________________________________________________________________________1 1.1 2.0 3.1 92 90 1.2 very good2 0.6 2.5 3.1 90 65 2.5 *3 1.1 2.5 3.6 92 90 1.2 very good4 1.1 2.0 3.1 92 90 1.2 very good__________________________________________________________________________ *plugging problems in hot separator due to high asphaltenes contained in the nonconverted residue.
In this situation, the amount of larger particles is increased up to 2.5% (Test 3) and the previous conversion results are recovered (92% residue conversion, 90% asphaltene conversion), but with 3.6 wt. % total catalyst, which is 0.5% higher than the Test 3 (Table 8).
When the initial operating conditions were reestablished, the 90% asphaltene conversion and 1.2% coke yield were recovered.
Summarizing, the charge of a non-normal catalyst size distribution to a bubble column hydrocracking reactor minimizes catalyst addition and reaction severity; said non-normal catalyst size distribution can be achieved through several means: a) the mixing of two or more different normal size distributions, to give a mixture characterized by R 2 <0.96, at any place in the catalyst production system and b) the separate addition of two or more size distributions (R 2 ≧0.97) to any place of the reacting system before or at the entrance to the hydrocracking reactor.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A catalyst for the hydrogenation of a hydrocarbon material which is a member selected from the group consisting of red mud, iron oxides, iron ores, hard coals, lignites impregnated with heavy metal salts, carbon black, soots from gasifiers, and cokes produced by the hydrogenation of virgin residues, the catalyst being comprised of at least two separate particle size fractions such that the combined fractions have a particle size distribution between 0.1 and 2,000 microns with 10-40 wt. % of the particles having a particle size greater than 100 microns, and the mixture of fractions not being represented by a straight line when the accumulative weight of the particles vs. particle size which is plotted on log (minus log) vs. log graph paper has a correlation coefficient R 2 less than 0.96 as determined from the equation: ##EQU1## wherein n is the number of experimental points, y is ln [-ln (n/1000)] and x is ln (dp), wherein dp is the particle size (μm) of the particles. | 2 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention pertains in general to protection devices and, more particularly, to protection devices for protecting integrated circuit devices from electrical transients, including electrostatic discharge (ESD) events.
BACKGROUND OF THE INVENTION
[0002] Integrated circuit devices have been subject to ever increasing susceptibility to damage from applications of excessive voltages, for example, by electrostatic discharge (ESD) events. This susceptibility is due, in large part, to ever decreasing gate oxide thicknesses which have resulted as very large scale integration (VLSI) circuit geometries continued to shrink. In particular, during an ESD event, charge is transferred between one or more pins of the integrated circuit to another conducting object in a time period that is typically less than one microsecond. This charge transfer can generate voltages that are large enough to break down insulating film (e.g., gate oxides) on the device, or can dissipate sufficient energy to cause electrothermal failures in the device. Such failures include contact spiking, silicon melting, or metal interconnect melting.
[0003] There have been many attempts made in the prior art to protect semiconductor devices, with particular attention to the problem of protecting field effect transistor devices from such ESD events. In the early days of MOS technology, a simple clamp was utilized such that a high voltage or ESD event on a pad or input pin associated with the integrated circuit resulted in “clamping” the voltage to ground with use of simple clipping diodes. Further, structures were incorporated in the circuitry associated with one or more of the input/output (IO) circuits that utilized reverse breakdown semiconductor junctions that would become conductive at high voltages. However, these devices sometimes prove to be insufficient to completely absorb the energy due to the conductivity therethrough or the speed thereof.
[0004] Recent ESD devices utilize clamping transistors that are turned on in the event of an ESD event. The control circuitry for this transistor typically includes a resistor and capacitor connected in series between the power supply and ground. Whenever an ESD event occurred that either pulled the pad below ground or above the supply terminal, the pn junction associated with a drive transistor, for example, on the pad would be forward biased and cause the ESD transistor to turn on and clamp the output across the output drive transistors to prevent damage thereto. However, the circuitry must be added to each I/O circuit and corresponding pad.
SUMMARY OF THE INVENTION
[0005] The present invention disclosed and claimed herein, in one aspect thereof, comprises an electrostatic discharge (ESD) protection device for protecting an integrated circuit with associated terminals, each having a functional relationship to the operation of the integrated circuit, the integrated circuit having an output driver with a p-channel transistor and n-transistor pair connected between one of the terminals configured as a power supply terminal and one of the terminals configured as a ground terminal for driving an associated one of the terminals configured as an input/output pad. An ESD event detector is provided for detecting an ESD event on any of the terminals. A drive circuit drives the n-channel and p-channel drive transistors in response to receiving a logic control signal to either drive the pad from the supply terminal or to sink the pad to ground. ESD protection logic circuitry is provided to cause both the p-channel and n-channel transistors to turn on when the ESD event detector detects an ESD event, the ESD protection circuitry disposed forward of the drive circuit such that the ESD protection logic circuitry operates independent of the state of the drive circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying Drawings in which:
[0007] [0007]FIG. 1 illustrates a prior art non overlap logic generator for driving a pair of output drive transistors and an ESD protection circuit;
[0008] [0008]FIGS. 2 and 3 illustrate details of the prior art configuration of FIG. 1;
[0009] [0009]FIG. 4 illustrates a general diagrammatic view of the ESD protection device of the present disclosure; and
[0010] [0010]FIG. 5 illustrates a more detailed logic diagram of the ESD protection device in association with the output drive circuitry of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0011] Referring now to FIG. 1, there is illustrated a logic diagram for a prior art ESD protection device. A pad 102 is provided that provides an input/output (I/O) function for the integrated circuit. It should be understood that there are many pads typically associated with an integrated circuit, only one of which is illustrated in the embodiment of FIG. 1. The pad 102 is typically driven by a driver circuit for driving a node 104 connected to pad 102 . The driver circuit consists of an n-channel transistor 106 operable to drive the node 104 to ground, transistor 106 having the source-drain path thereof connected between node 104 and ground. The driver circuit is also comprised of a p-channel transistor 108 for pulling the node 104 up to Vdd, this allowing current to be driven to the node 104 through the source-drain path of transistor 108 connected between Vdd and node 104 .
[0012] A non-overlap logic generator 110 is provided for driving the gates of transistors 106 and 108 . The drive signal for the gate of transistor 106 is referred to as an “ng” drive signal and the drive for the gate of transistor 108 is referred to as a “pg” drive signal. Generator 110 receives two inputs, an “n” drive input and an “pb” drive input. The generator is operable to allow for tri-stating of the driver such that the gate of transistor 108 will remain high and the gate of transistor 106 will remain low such that there is no conduction there through in the tri-state configuration.
[0013] The generator 110 is comprised of a NAND gate 112 having one input thereof connected to the “n” input signal the other input thereof connected to the “pg” output node on the gate of transistor 108 . A NOR gate 114 has one input thereof connected to the “pb” input signal and the other input thereof connected to the “ng” output signal that drives transistor 106 . The output of NOR gate 114 is input to an invertor 116 , the output thereof connected to the “pg” drive signal to transistor 108 . The output of NAND gate 112 is connected to the input of an invertor 118 , the output thereof connected to the “ng” output signal that drives transistor 106 .
[0014] In operation, when the state of the pad 102 is low, and “pb” goes low, pad 102 will remain low until the state of “n” goes low. When “n” goes low, the output of NAND gate 112 goes high and the output of invertor 118 goes low, turning off transistor 106 and driving pad 102 high, since NOR gate 114 will drive the output of inverter 116 low and turn on transistor 108 . If “n” then goes high, and then “pb” goes high, then the output of inverter 16 will be driven high, turning off transistor 108 and driving the output of NAND gate low and the output of inverter 118 high, turning on transistor 106 .
[0015] For the purpose of addressing ESD events, the transistors 106 and 108 must be protected in the event that the pad 102 is subjected to a high-going spike or a low-going spike as well as all internal transistors connected to node 104 and the supply nodes. Illustrated in FIG. 1 in phantom is an intrinsic diode 120 having the anode connected to ground and the cathode thereofconnected to the node 104 , and a phantom diode 122 having the anode thereof connected to node 104 and the cathode thereofconnected to V dd . The diodes 120 and 122 are an intrinsic part of the transistors 106 and 108 , as is well know in the art. Further, the transistors 106 and 108 can be fabricated to accentuate or provide an enhanced ESD pn junction across the transistor. In general, the diode results from the p-substrate for the n-channel transistor 106 , for example, that is connected to ground wherein the pn junction exists between the source and drain in transistor 106 (or transistor 108 ) and the p-substrate. For a p-channel device, the diode is between the p-drain and the n-well connected to V dd .
[0016] With reference to FIGS. 2 and 3, there is illustrated a detail of a high going spike and a low going spike, respectively. When the pad 102 is pulled high in the presence of an ESD event, this will cause diode 122 to become forward biased and conduct. If, on the other hand, the pad 102 were pulled low below ground, this would cause diode 120 to conduct. A clamp n-channel transistor 124 is provided with the source/drain path thereof connected between the Vdd and ground and the gate thereof connected to a node 126 . Node 126 is connected to one side of a resistor 128 , the other side thereof connected to ground, node 126 also connected to one plate of a capacitor 130 , the other side thereof connected to V dd . When the pad 102 goes high, diode 122 will pull the top plate of capacitor 130 at the V dd terminal high, thus pulling node 126 high and turning transistor 124 on. When pad 102 goes low, diode 120 will pull the ground node low, with node 126 remaining high due to the fact that the capacitor 130 is still connected on the top plate thereofto V dd . This will cause transistor 124 to conduct and “clamp” V dd and ground, thus protecting transistors 106 and 108 . (Note that a p-channel transistor could have been utilized as the clamp transistor by merely reversing the capacitor 130 and resistor 128 of FIG. 1).
[0017] Referring now to FIG. 4, there is illustrated an overall logic diagram of the ESD protection circuit of the present disclosure. The output is provided on a node 404 that drives an output pad 406 . Two drive transistors, a p-channel transistor 408 and an n-channel transistor 410 are provided with the source-drain path of the p-channel transistor 408 connected between V dd and node 404 , and the source-drain path of transistor 410 connected between node 404 and ground. The gate of transistor 408 and the gate of transistor 410 are driven by a non-overlap logic generator, as was described hereinabove with reference to FIG. 1. The input signals to the generator are comprised of the primary “n” drive logic signal and the “pb” drive signal. The “n” signal is input to one input of a two-input NAND gate 412 , the other input thereof connected to the gate of transistor 408 . The output of the NAND gate 412 is connected to the input of a bypass circuit 414 , the output thereof connected to the input of an invertor 416 , the output of inverter 416 driving the gate of transistor 410 . The “pb” signal is input to one input of a two-input NOR gate 418 , the other input thereof connected to the output of invertor 416 . The output of the NOR gate 418 is connected to the input of a bypass circuit 420 , the output thereof connected to the input of an invertor 422 , the output of inverter 422 connected to the gate of transistor 408 . When the bypass circuits 414 and 420 are operating to bypass the logic function associated therewith, the generator of FIG. 4 will operate identical to the generator 110 of FIG. 1.
[0018] An ESD capacitor 430 has a top plate thereof connected to V dd and a bottom plate thereof connected to an ESD control node 432 . An ESD resistor 434 is connected between node 432 and ground. The ESD control node 432 is connected to a control input on both of the bypass circuits 420 and 414 .
[0019] As noted herein above, each of the transistors 408 and 410 has associated therewith an intrinsic diode (not shown), such that raising of the pad 406 high through an ESD event will result in the diode pn junction associated with transistor 408 being forward biased and pulling the V dd terminal high relative to ground. This will cause node 432 to be pulled up, which will cause bypass circuit 414 to output a low signal regardless of the state of any of the other logic circuitry and drive a logic high on the output of invertor 416 turning on transistor 410 , and bypass circuit 420 will also output a logic “high” state to drive the output of invertor 422 low, turning on transistor 408 , such that transistor 410 and 408 clamp V dd to ground. The bypass circuits 414 and 420 are pushed “forward” of the controlling logic circuitry embodied in the NOR gate 418 and the NAND gate 412 . This bypass circuits 414 and 420 therefore utilizes the source/drain path transistors 408 and 410 in lieu of a separate n-channel transistor clamp for clamping V dd to ground.
[0020] Referring now to FIG. 5, there is illustrated a detailed logic diagram of a circuit FIG. 4 and the bypass circuitry 414 and 420 . The pb signal is input to one input of a two input OR gate 502 , the other input thereof connected to the gate of transistor 410 . The output of OR gate 502 is connected to one input of the two input NAND gate 504 , the other input thereof connected to a node 506 . Node 506 is connected to the output of an invertor 508 , the input thereof connected to the ESD control node 432 . The output of NAND gate 504 is connected to the input of invertor 422 in order to drive the gate of transistor 408 .
[0021] The “n” input signal is input to one input of a two-input AND gate 510 , the other input thereof connected to the output of invertor 422 . The output of AND gate 510 is input to one input of a two-input NOR gate 512 , the output thereof connected to the input of the invertor 416 and the other input of NOR gate 512 is connected to the output of an invertor 518 , the input of invertor 518 connected to node 506 . It should be noted that the other input of NOR gate 512 not connected to the output of AND gate 510 could be connected directly to node 532 . By utilizing the invertor 518 , some “clock bouncing” can be ameliorated.
[0022] In operation, when “n” is at a logic “low,” the output of AND gate 510 is low and, when no ESD event is present, the output of invertor 518 will be low due to node 432 being low. This will result in the output of NOR gate 512 being high and the output of invertor 416 being low, thus turning off transistor 410 . This will also place a logic “low” on the input to OR gate 502 . Shortly thereafter, “pb” is taken low, which will result in the output of OR gate 502 going low and the output of AND gate 504 being high and the output of invertor 422 being low, turning on transistor 408 .
[0023] For the opposite logic state, “pb” goes high, resulting in a logic high to the input of NAND gate 504 . The other input to NAND gate 504 , during a non-ESD event will be high, such that the output of NAND gate 504 is low and the output of invertor 422 is high, turning off transistor 408 . “n” goes high, raising the output of AND gate 510 high and causing the output of NOR gate 512 to go low and the output of invertor 416 to go high, turning on transistor 410 . Transistor 408 will therefore be turned off and transistor 410 turned on.
[0024] During a high going ESD event, node 432 will be “high” due to the intrinsic pn junction in transistor 408 being forward biased and current being driven to the V dd terminal. This will result in node 506 being pulled low, which results in the output of NAND gate 504 going high and the output of invertor 422 going low and turning on transistor 408 . Similarly, the output of invertor 518 will be at a logic “high” resulting in the output of NOR gate 512 going low and the output of invertor 416 going high, turning on transistor 410 . Therefore, for a high going ESD event, transistors 408 and 410 will be turned on clamping the V dd to ground.
[0025] In the opposite condition, wherein the pad is subjected to a negative-going ESD event, ground will be pulled low resulting in node 432 being at a “high” voltage level to cause node 506 to go low. This will also result in transistors 408 and 410 being turned on. It is noted that the logic associated with the gates 502 and 510 , which form part of the non-overlap generator are not a portion of the control logic that controls transistors 408 and 410 being turned on during the ESD event. As such, the gates 504 and 512 associated with the bypass operation are disposed “forward” of the normally operating gate logic. In general, the gates 502 and 504 are referred to as an OR-NAND configuration and the gates 510 and 512 are referred to as an AND-NOR combination.
[0026] Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | Electrostatic discharge (ESD) clamp using output driver. An electrostatic discharge (ESD) protection device for an output driver having a p-channel transistor and n-transistor pair connected between a power supply terminal and ground for driving an input/output pad therefrom. An ESD event detector is provided for detecting an ESD event on the pad. A drive circuit drives the n-channel and p-channel drive transistors in response to receiving a logic control signal to either drive the pad from the supply terminal or to sink the pad to ground. ESD protection logic circuitry is provided to cause both the p-channel and n-channel transistors to turn on when the ESD event detector detects an ESD event, the ESD protection circuitry disposed forward of the drive circuit such that the ESD protection logic circuitry operates independent of the state of the drive circuit. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of PCT application Ser. No. PCT/EP03/02316, filed Mar. 6, 2003, published in German, which claims the benefit of German Application No. 102 11 958.9, filed Mar. 18, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a high-purity silica powder and to a process and apparatus for producing it in a hot zone.
[0004] 2. Description of the Related Art
[0005] High-purity silica powders are employed in numerous technical fields. Examples of application areas include optical fibers, quartz crucibles for pulling silicon single crystals, optoelectronics (e.g. lenses and mirrors), fillers in passive components used in electronics, and polishing suspensions for wafers (chemical mechanical polishing). A high powder purity is required for the abovementioned applications.
[0006] In optical fibers made from SiO 2 for optical communications, the radiation intensity of the information carrier light should not be reduced by absorption caused by impurities such as OH, iron and copper, or by scattering caused by bubbles, crystallization nuclei and inhomogeneities. Crystallization nuclei are formed by impurities such as calcium and magnesium.
[0007] In quartz glass crucibles, corrosion of the inner surface of the crucible occurs during the process of pulling silicon single crystals as a function of the number and type of impurities. Corrosion reduces the potential pulling time. Moreover, each additional impurity increases the number of nuclei at which oxygen precipitates may form during cooling of the single crystal.
[0008] In optical glasses, by way of example, sodium and transition metals are responsible for transmission losses in the glass. Therefore, it is necessary for the concentration of the transition metals not to exceed 100 ppb. Only then can it be ensured that the transmission at a wavelength of 248 nm is greater than 99.5% and at a wavelength of 193 nm is greater than 98%. Moreover, silica powders for optical fibers, quartz crucibles and glasses must be free of organic impurities, since otherwise numerous bubbles may form during the sintering step.
[0009] High-purity SiO 2 can also be used as a filler in epoxy resins for protecting IC chips if the concentration of the elements iron, sodium, and potassium does not exceed 0.2 ppm and the concentration of aluminum and titanium does not exceed 1 ppm. These elements change the coefficient of thermal expansion, the electrical conductivity, and the corrosion resistance of the passive components, which can deactivate the chip protection function.
[0010] Polishing suspensions of SiO 2 are used for direct polishing of semiconductor surfaces. The SiO 2 used for this purpose must not, for example, in the case of aluminum, exceed a concentration of 4 ppm.
[0011] A known process for producing high-purity silica powders is the hydrolysis of silicon-containing precursors. For example, SiCl 4 may be hydrolyzed in water in the presence of an organic solvent (Degussa DE 3937394), or by mixing ammonium fluorosilicate first with ammonia water and then with hydrofluoric acid (Nissan, JP 04175218), or by precipitating silica by the addition of a dilute mineral acid to an alkali metal silicate (Nippon, EP 9409167, University of Wuhan, CN 1188075). The silica so formed is also known as precipitated silica, and is used primarily as a catalyst support and as an epoxy resin filler for protecting LSI and VLSI circuit devices. The abovementioned processes produce porous, bubble-containing imperfect spherical particles with poor flow properties. A further, very significant drawback, is that these processes are subject to purity limitations, since certain impurities such as OH, C, F, N, as well as alkali metals such as Na and K, are to a certain extent introduced by the process. These drawbacks lead to considerable light scattering and absorption and to a reduced mechanical and thermal stability of the application product. Therefore, this process is fundamentally unsuitable for use in the optical fiber, crystal pulling crucible, and glass technology sectors.
[0012] Natural quartz is also ruled out for the above applications on account of the strict purity requirements. However, there have been many attempts to achieve acceptable purity levels by the additional process step of further purification of insufficiently pure quartz. According to DE 3123024 (Siemens), natural quartz is converted into thin fibers by melting, and then these fibers are subjected to a plurality of leaching process steps using acids and bases. On account of the high surface area and small thickness of the fibers, the level of transition metal ions can be reduced to less than 1 ppm. This process is inexpensive, since the fibers are used directly for applications in the optical fiber sector. If, for further applications and shaped body geometries, in accordance with DE 3741393 (Siemens), the purified fibers are milled, converted into a slip with the aid of water, dispersants, and other auxiliaries, and then a slip casting process and finally a sintering process are carried out, the ultimate result is a complex process with numerous contamination sources.
[0013] According to EP 0737653 (Heraeus), natural quartz is subjected to the process steps of milling, screening, preheating to 1000° C., treatment with Cl 2 /HCl, cooling and desorption. This time-consuming process gives purities of around 70 ppb with regard to Fe. Impurities derived from alkaline-earth metals and Al, which are known to form cristobalite and therefore, for example, reduce crucible quality, cannot be removed to this extent, since these elements form chlorides of low volatility (prior to treatment: Na=1100 ppb, K=1050 ppb, Li=710 ppb, Ca>370 ppb, Al=16,000 ppb, Fe=410 ppb; subsequently: Na<10 ppb, K>80 ppb, Li=700 ppb, Ca>120 ppb, Al=16,000 ppb, Fe>30 ppb).
[0014] According to U.S. Pat. No. 4,818,510 (Quartz Technology), quartz can be purified further using HF. However, HF only reacts selectively with certain elements, such as iron, with which it forms readily soluble complexes.
[0015] Further purification has also been carried out on SiO 2 granules. According to U.S. Pat. No. 6,180,077 and EP 1088789 (Heraeus), SiO 2 granules are produced and are purified at high temperatures by means of HCl. One advantage is that the granules have a high surface area and can therefore be acted on more easily and more quickly by HCl. If the starting point granules have a purity of Na<50 ppb, Fe=250 ppb, Al<1 ppm, the further purification makes it possible to achieve very high purity levels (Na=5 ppb, Fe=10 ppb, Al=15 ppb). One disadvantage is that it is first necessary to produce highly porous silica granules (pore volume 0.5 cm 3 , pore diameter 50 nm, BET 100 m 2 /g, density 0.7 g/cm 3 , granule size 180-500 μm), which is a time-consuming process, and these granules do not yet represent the finished products, but rather, still have to be sintered. Furthermore, the high porosity conceals the latent risk of gases remaining included during sintering following shaping, for example, to form a crucible.
[0016] According to U.S. Pat. No. 4,956,059 (Heraeus), in addition to the purification gases Cl 2 /HCl used at high temperatures, an electric field (typically 652 V/cm) can also be used in the further purification of silica granules. The further purification effect is stronger in the presence of the electric field, in particular with the alkali metal ions, which migrate well in the electric field, being affected by the field. This method makes it possible to reduce the sodium level, for example from 1 ppm to 50 ppb.
[0017] According to EP 1006087 (Heraeus), further purification can be carried out in a process where impure powder is heated in a gas stream, with the impurities softening and forming molten agglomerates, and the powder then being guided on to an impact surface, to which only the impure molten agglomerates adhere. This method only makes sense for very impure starting material powders. However, further purification with regard to high-melting oxides, such as MgO and Al 2 O 3 is not possible in this way. The high quantities of gases required for this purpose represent a further drawback.
[0018] High purities (metal impurity levels<1 ppm, C<5 ppm, B<50 ppm, P<10 ppb) are achieved using the sol-gel process, in which first a sol and then a gel are formed from an organic silane and water. This is followed by the process steps of drying, calcining using inert gas, and sintering (Mitsubishi, EP 0831060, EP 0801026, EP 0474158). The process is very time-consuming and is also expensive, since high-purity organosilanes act as starting materials. In general, an organic-based rheological auxiliary, a dispersant and a solvent are used for the production process, with the result that the finished product may contain black carbon particles and CO and CO 2 bubbles. The use of water leads to a high OH content, and consequently to the formation of bubbles in the product and to a product having low thermal stability. If this material is used for producing silica crucibles for the production of Si single crystals using the Czochralski process, the bubbles and pores expand on account of the high temperature and the reduced pressure. During the pulling process, bubbles are responsible not only for turbulence in the silicon melt but also for the formation of crystal defects and a deterioration in the long-term stability of the crucible.
[0019] In principle, high-purity silica is also produced by precipitation of silica from high-purity organosilanes or SiCl 4 in the presence of an oxy-fuel flame using the CVD or OVD process (Corning, U.S. Pat. No. 5,043,002, U.S. Pat. No. 5,152,819, EP 0471139, WO 01/17919, WO 97/30933, WO 97/22553, EP 0978486, EP 0978487, WO 00/17115). However, this process does not produce powders, but rather glass bodies having a defined, simple geometry. The simple geometries include optical glasses and lenses. Optical fibers can be obtained from the high-purity glass body by drawing. To produce glass bodies of any other geometry from the simple glass bodies, the glass must first be milled to form a powder, dispersed, shaped, and sintered. However, this process can entail widespread contamination, in particular during the milling step.
[0020] A further drawback of this process is that expensive, high-purity organosilanes, such as, for example, octamethylcyclotetrasiloxane (OMCTS), are used in order to achieve particularly high purities.
[0021] High-purity SiO 2 layers can also be produced by deposition on high-purity substrates (e.g. by plasma CVD/OVD, GB 2208114, EP 1069083). One drawback of such a process is that it is only possible to achieve low deposition rates of 150 nm/min (e.g. J. C. Alonso et al., J. V AC. S CI. T ECHNOL. A 13(6), 1995, pp. 2924 ff.) . Coating processes entail high production costs. High purity silica powders are not obtainable by these processes.
[0022] A simple alternative process is the formation of silica in a flame. Two different approaches are known in this respect. According to JP 5-193908 (Toyota/ShinEtsu), high-purity silicon metal powder can be oxidized to form high-purity silica powder by means of a C n H 2n+2 /O 2 flame, the C n H 2n+2 being required only for ignition. However, the inventors themselves acknowledge the problem that the reaction produces a large number of unburnt particles. Full oxidation is difficult to realize unless the starting particles are very fine (0.2 μm). However, it is in turn almost impossible to produce such fine Si particles in a highly pure form.
[0023] Alternatively, fumed silica can be produced from SiCl 4 in an oxyhydrogen flame in a first step by flame hydrolysis and this fumed silica can be converted into fused silica by sintering in a second step.
[0024] The term fumed silica is to be understood as meaning ultrafine-particle, nanoscale powders which are produced by reacting silanes in a high-temperature flame and are often greatly aggregated and agglomerated. One typical example of fumed silica is Aerosil® OX 50 produced by Degussa, with a BET surface area of 50 m 2 /g. The term fused silica is to be understood as meaning coarser-grained, spherical glass powders. One typical example of fused silica is Excelica® SE-15 produced by Tokuyama with a mean particle size of 15 μm.
[0025] According to U.S. Pat. No. 5,063,179 (Cabot), the second substep, i.e. the production of fused silica, is implemented by fumed silica being dispersed in water, filtered, dried, purified further using SOCl 2 or Cl 2 and being sintered in a furnace. The concentrations of the impurities, such as Na and Fe, are then around 1 ppm (total content of impurities <50 ppm), i.e. still rather high.
[0026] According to JP 59152215 and JP 5330817 (Nippon Aerosil), in the second substep (the production of fused silica), the fumed silica powder is transferred in dispersed form, for example directly by means of a screw conveyer, into an oxyhydrogen flame and sintered to form fused silica powder.
[0027] According to JP 5301708 and JP 62-270415 (Tokuyama), to produce fused silica, high purity fumed silica is treated with H 2 O vapor, cooled, fluidized, and fed by means of a screw conveyer to an oxyhydrogen flame for the purpose of sintering. The fused silica product obtained using the abovementioned processes contains >1000 ppb of impurities, as a cumulative sum of the elements Cu, Fe, Ti, Al, Ca, Mg, Na, K, Ni, Cr, Li. The dispersion and conveying of the fumed silica particles in accordance with the abovementioned processes is carried out, for example, with the aid of a screw conveyer. The screw is a moving part which becomes worn through contact with silica, in particular in the region of the edges. As a result, the screw contaminates the silica powder. Other components of the installation are also exposed to the abrasive silica particles and therefore to heavy wear. Mention should be made in particular of the burner nozzle, in which the velocities of the silica powders are particularly high.
SUMMARY OF THE INVENTION
[0028] It was an object of the present invention to provide a silica powder of very high purity. A further object of the present invention was to provide a process and apparatus for the inexpensive production of the powder according to the invention. The first object is achieved by a silica powder in which the sum of impurities is less than 500 ppb. This and other objects are met by flame hydrolysis of high purity SiCl 4 , the hydrolysis preferably taking place in a reactor having a metal-free surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 shows the burner outlet as a 3-tube burner nozzle without premixing of O 2 with SiCl 4 or fumed silica.
[0030] FIG. 2 shows the burner outlet comprising 7 nozzles without premixing of O 2 with SiCl 4 or fumed silica.
[0031] FIG. 3 shows the burner outlet comprising 7 nozzles with premixing of O 2 with SiCl 4 or fumed silica.
[0032] FIG. 4 shows the burner comprising 7 quartz glass nozzles with premixing of O 2 with SiCl 4 or fumed silica.
[0033] FIG. 5 shows the plasma torch.
[0034] FIG. 6 shows fused silica powder from Example 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] It is preferable for the total amount of impurities in the silica powder according to the invention to be less than 300 ppb, more preferably less than 150 ppb, and yet more preferably less than 100 ppb. Most preferably, the sum of impurities is less than 150 ppb and the individual impurity levels are Cu<1 ppb, Fe<25 ppb, Ni<2 ppb, Cr<2 ppb, Ti<3 ppb, Al<31 ppb, Ca<65 ppb, Mg<12 ppb, Na<12 ppb, K<6 ppb, and Li<1 ppb, and the powder is substantially carbon-free.
[0036] The impurity levels are determined using ICP analysis (inductively coupled plasma, apparatus: ICP-MS HP4500), for which the detection limit is less than 1 ppb. The silica powders may be either fumed silica or fused silica.
[0037] The fumed silica particles preferably have a BET surface area of between 50 and 300 m 2 /g, most preferably between 150 and 250 m 2 /g. The primary particle size is between 1 nm and 1000 nm, preferably between 5 nm and 100 nm, and most preferably between 10 nm and 30 nm.
[0038] The fused silica powder preferably has a mean particle size of between 100 nm and 200 μm, more preferably between 1 μm and 200 μm, and most preferably between 5 μm and 40 μm. Furthermore the powder preferably has a narrow particle size distribution, with D(95)−D(5)<50 μm, more preferably D(95)−D(5)<35 μm, e.g. with a mean particle size of D(50)=15 μm: D(5)=1 μm, D(95)=50 μm, more preferably D(5)=3 μm, D(95)=35 μm, measured using CILAS 715.
[0039] The narrow particle size distribution of the product produced according to the invention means that additional process steps such as screening, are not required, and the powder is directly suitable for further processing. FIG. 6 shows, by way of example, the very uniform particle size distribution of a fused silica powder which has been produced in accordance with Example 4.
[0040] The fused silica particles preferably have a spherical morphology and are completely vitrified. Unlike powders produced using the sol-gel process, they do not include any bubbles or carbon impurities originating from the use of organic solvents, dispersants and rheological agents.
[0041] The high-purity fumed silica and fused silica powders according to the invention can be used for all applications for which fumed and fused silica are useful. They are eminently suitable for the production of shaped bodies as described, for example, in DE 19943103 (Wacker Chemie GmbH).
[0042] A powder according to the invention is preferably produced by means of a process in which a high-purity fumed silica powder is obtained by hydrolysis of high-purity SiCl 4 , wherein the hydrolysis of the SiCl 4 to form the fumed silica powder is carried out in an apparatus having a metal-free surface. The hydrolysis of the high-purity SiCl 4 is carried out in a flame comprising an oxygen-containing gas and a gas selected from the group consisting of hydrocarbon and hydrogen, or mixture thereof. The flammable gas mixture preferably comprises air or oxygen and methane, propane and/or hydrogen gas, most preferably, oxygen and hydrogen. Thus, hydrolysis preferably takes place in an H 2 /O 2 flame. Alternatively, the hydrolysis may be carried out in a plasma, for example in an HF plasma.
[0043] It is also preferable for the deposition or “collection” of the fumed silica powder to be carried out in an apparatus with a metal-free surface.
[0044] Other suitable starting materials include silanes, organosilicon compounds, and halosilanes with an impurity level of <100 ppb. SiCl 4 with an impurity level of <100 ppb is very suitable, and SiCl 4 with the purity as set forth in Table 1 is preferably suitable.
[0045] A likewise high-purity fused silica powder can be produced from the fumed silica powder in accordance with the invention by sintering the fumed silica first produced. The sintering of the high-purity fumed silica powder is preferably carried out in an apparatus similar to that used to produce the fumed silica powder, in an H 2 /O 2 flame or by means of an HF plasma. A controlled quantity of water can also be added to the fumed silica to control the particle size of the fused silica powder.
[0046] To avoid contamination from environmental elements, such as Na, K, Mg or Ca, it is preferable to work under clean room conditions and/or under a laminar flow. The process is, in this case, carried out under clean room conditions from classes 100,000 to 1, preferably 10,000 to 100, most preferably, 1000.
[0047] As an alternative to clean room conditions, the process can be carried out at a pressure of between 0.913 bar and 1.513 bar, preferably between 1.013 bar and 1.413 bar, and most preferably between 1.020 bar and 1.200 bar. The superatmospheric pressure prevents impurities from entering the installation.
[0048] If the inventive powder is produced in an H 2 /O 2 flame, the apparatus according to the invention is preferably a nozzle comprising an inner tube located within an outer tube, with an annular space therebetween, and with a starting material selected from SiCl 4 , a mixture of SiCl 4 with O 2 , fumed silica, and a mixture of fumed silica with O 2 being passed through the inner tube, wherein the inner tube consists of a silicon-containing material with silicon as the main constituent, such as for example quartz glass, fused quartz, SiC, Si 3 N 4 , enamel, or silicon metal. Preferably, the surface of the material of the inner tube will have been purified, using a chlorine-containing gas, such as, for example SOCl 2 , HCl, or Cl 2 .
[0049] The apparatus is most preferably a nozzle in which the inner tube consists of quartz glass or a material with a quartz glass surface, which, again, has preferably been purified using a chlorine-containing gas such as, SOCl 2 , HCl or Cl 2 .
[0050] It is most preferable for the entire nozzle to consist of quartz glass or a material with a quartz glass surface. The purity can be increased still further if the quartz glass or the material with the quartz glass surface has been purified using, for example, SOCl 2 , HCl or Cl 2 .
[0051] If only the inner tube for the supply of fumed silica or SiCl 4 consists of quartz glass, while the remainder of the nozzle consists, for example, of steel, the purity of the powder produced is slightly worse than with a nozzle made from quartz glass, but is still higher than in the case of known silica powders.
[0052] Therefore, the invention also pertains to a nozzle comprising an inner tube located in an outer tube, with an annular space therebetween, wherein the inner tube consists of a silicon-containing material with silicon as the main constituent. This material is preferably selected from the group consisting of quartz glass, fused quartz, SiC, Si 3 N 4 , enamel or silicon metal. By the term “main constituents” is meant that the most substantial part of the metal content comprises silicon.
[0053] It is preferable for the nozzle to consist of a material selected from the group consisting of quartz glass, fused quartz, SiC, Si 3 N 4 , enamel or silicon metal, most preferably of quartz glass.
[0054] The nozzle is preferably a nozzle wherein premixing of the fuel gases is not employed. In a nozzle of this type, the fuel gases H 2 and O 2 are fed to the combustion chamber separately. In one embodiment of the nozzle according to the invention, SiCl 4 and/or fumed silica are premixed with one of the fuel gases, preferably with O 2 , in a pilot chamber 7 , and the mixture is then fed to the combustion chamber. The nozzle comprises an inner tube 5 for supplying the mixture of O 2 and fumed silica (SiCl 4 ) and an outer tube 6 for supplying H 2 ( FIGS. 3 and 4 ).
[0055] In another embodiment of the nozzle according to the invention, all the reactants (H 2 , O 2 , SiCl 4 and/or fumed silica) are fed to the combustion chamber separately. The nozzle comprises concentrically arranged tubes 2 , 3 , 4 , for the supply of fumed silica (SiCl 4 ), O 2 and H 2 . One possible arrangement comprises an inner tube for the supply of fumed silica (SiCl 4 ), a middle tube for the supply of O 2 and an outer tube for the supply of H 2 ( FIG. 1 ).
[0056] It is preferable for a burner 10 for producing powder according to the invention by means of H 2 /O 2 flame to comprise a plurality of the nozzles. The burner delivers a powder with a narrow particle size distribution when a single nozzle is used, ( FIG. 1 ), and a particularly narrow particle size distribution with a plurality of nozzles in which the starting materials are supplied through three concentric tubes ( FIG. 2 ), and a yet further more narrow particle size distribution with a plurality of nozzles and an O 2 /fumed silica premixing chamber with the starting materials being supplied through two concentric tubes 5 , 6 ( FIGS. 3 and 4 ). This arrangement allows a particularly homogeneous distribution of the SiCl 4 , or of the fumed silica powder when producing fused silica powder, in the flame.
[0057] Therefore, the invention also relates to a burner 10 which includes 1 to 30, preferably 6 to 13, more preferably 7 nozzles. That surface of the burner which faces the combustion chamber preferably likewise consists of quartz glass. A burner 10 with 7 nozzles of this type is illustrated in FIG. 4 , while FIG. 3 diagrammatically depicts a plan view of a burner of this type. FIG. 2 diagrammatically depicts a plan view of a burner with 7 nozzles in which all 3 starting materials, as described above, are introduced separately into the combustion chamber.
[0058] The dispersion of the fumed silica in the flame is improved still further in the variant of the nozzle according to the invention in which O 2 and fumed silica powder are premixed before being fed to the combustion chamber.
[0059] If the powder according to the invention is produced in a plasma, the apparatus according to the invention is a plasma torch 11 comprising a powder nozzle 12 , an intermediate tube 13 , and an outer tube 14 ( FIG. 4 ), with the powder nozzle, the intermediate tube and the outer tube having a surface made from a silicon-containing material with silicon as the main constituent. It is preferable for the surface to consist of a material selected from the group consisting of quartz glass, fused quartz, SiC, Si 3 N 4 , enamel or silicon metal. It is preferable for the surface to be purified using a gas, such as SOCl 2 , Cl 2 or HCl. SiCl 4 or the fumed silica powder is metered in via the powder nozzle, the plasma gas O 2 is metered in via the intermediate tube 13 and the shrouding gas mixture O 2 and H 2 is introduced via the outer tube.
[0060] It is highly preferable to use a plasma torch in which the powder nozzle, the intermediate tube and the outer tube have a surface made from quartz glass, especially a plasma torch having a surface made from quartz glass.
[0061] The plasma torch 11 furthermore has an induction coil 15 with water cooling 16 as well as a water cooling jacket 17 .
[0062] High-purity powders can be produced directly using the apparatuses of the invention. The further purification process steps which are usually required are avoided. Fumed and fused silica powders of extremely high purities (Table 1), which have not been achieved using conventional processes, can be produced using a nozzle according to the invention. The purity can be increased still further by combustion in a nozzle made from quartz glass under clean room conditions. Furthermore, it is advantageous if all the surfaces of the installation for producing the fumed or fused silica powder which come into contact with a starting material in powder form, or the product according to the invention, are designed to be free from contamination. Therefore, an inventive apparatus for producing a silica powder is preferably distinguished by the fact that all the surfaces that come into contact with the silica powder are metal-free. “Metal-free” means free of metal other than silicon. An installation for producing a silica powder is known to comprise a) a metering apparatus, b) a burner, c) a combustion chamber, d) a cyclone and e) a silo. In the case of fumed silica production, a fluidized bed is generally also connected between the cyclone and the silo.
[0063] The materials which have been mentioned for the nozzle of the invention preferably also form the surface of the metering, the combustion chamber, the cyclone, the fluidized bed, and the silo. In another embodiment, the metering apparatus and the silo may also have a pure plastic surface. The plastics may, for example be PFA (perfluoroalkoxy copolymer), PTFE (polytetrafluoroethylene), Halar® E-CTFE, GFP (glass fiber-reinforced polyester resin) and PP (polypropylene). In the metering region, it is preferable for the silica powders to be conveyed without moving parts, for example by using pneumatic conveying by means of compressed air.
[0064] The following examples serve to further explain the invention.
EXAMPLE 1
[0000] Production of a Fumed Silica Powder from SiCl 4 by Means of an Oxyhydrogen Flame without Clean Room Conditions
[0065] To produce a fumed silica powder from SiCl 4 , the reactants SiCl 4 , O 2 and H 2 are passed into the combustion chamber by means of a quartz glass nozzle without premixing. The reaction is carried out using 16.6 g/min of SiCl 4 +6.3 l/min of O 2 +8.9 l/min of H 2 . The combustion chamber is operated at a pressure of 20 mbar above atmospheric pressure. Table 1 shows the analytical results.
EXAMPLE 2
[0000] Production of a Fumed Silica Powder from SiCl 4 by Means of an Oxyhydrogen Flame using Clean Room Conditions
[0066] To produce a fumed silica powder from SiCl 4 , the reactants SiCl 4 , O 2 and H 2 are passed into the combustion chamber by means of a quartz glass nozzle without premixing. The reaction is carried out using 16.6 g/min of SiCl 4 +6.3 l/min of O 2 +8.9 l/min of H 2 . The entire installation is in a clean room belonging to clean room class 10,000. Table 1 shows the analytical results.
EXAMPLE 3
[0000] Production of a Fused Silica Powder from a Fumed Silica Powder by Means of an Oxyhydrogen Flame without Clean Room Conditions
[0067] To produce fused silica powder from fumed silica powder, the reactants fumed silica, O 2 and H 2 are passed into the combustion chamber by means of a quartz glass nozzle without premixing. The reaction is carried out using 180 l/min of H 2 +90 l/min of O 2 +60.3 g/min of fumed silica powder. The combustion chamber is operated at a pressure of 40 mbar above atmospheric pressure. Table 1 shows the analytical results.
EXAMPLE 4
[0000] Production of Fused Silica Powder from Fumed Silica Powder by Means of an Oxyhydrogen Flame under Clean Room Conditions
[0068] To produce fused silica powder from fumed silica powder, the premixed reactants fumed silica powder, O 2 and H 2 are passed into the combustion chamber by means of a quartz glass nozzle. The reaction is carried out using 180 l/min of H 2 +90 l/min of O 2 +60.3 g/min of fumed silica powder. The entire installation is in a clean room belonging to clean room class 10,000. Table 1 shows the analytical results.
EXAMPLE 5
[0000] Production of Fused Silica Powder from Fumed Silica Powder by Means of HF Plasma under Clean Room Conditions
[0069] To produce fused silica powder from fumed silica powder, the reactants fumed silica powder, air and H 2 are passed into the combustion chamber via a torch comprising quartz glass cylinders. The reaction is carried out using 45 l/min of O 2 as the central plasma gas, 90 l/min of O 2 and 25 l/min of H 2 as the shrouding gas and 15 kg/h of fumed silica powder, metered in via the powder nozzle. The pressure in the combustion chamber is 300 torr, and the total power of the HF plasma is 90 kW. In the present case, the plasma is an HF plasma in accordance with the principle of solid state technology, with which the person skilled in the art will be familiar. The entire installation is in a clean room belonging to clean room class 10,000. Table 1 shows the analytical results.
EXAMPLE 6
[0000] Production of Fused Silica Powder from Fumed Silica Powder by Means of Oxyhydrogen Flame under Clean Room Conditions using Standard Nozzle, not Made from Quartz Glass
[0070] To produce fused silica powder from fumed silica powder, the reactants fumed silica powder, O 2 and H 2 are passed into the combustion chamber by means of a stainless steel nozzle with premixing. The reaction is carried out using 180 l/min of H 2 +90 l/min of O 2 +60.3 g/min of fumed silica powder. The entire installation is in a clean room belonging to clean room class 10,000. Table 1 shows the analytical results.
COMPARATIVE EXAMPLE 7
[0000] Production of Fused Silica from Fumed Silica by Means of Oxyhydrogen Flame in Accordance with Patent JP 59152215.
[0071] The high-purity fumed silica powder is passed into an oxygen stream via a screw conveyer and then passed into the burner tube. The burner comprises 3 tubes, with 7.6 m 3 /h of H 2 being introduced into the combustion chamber via the inner and outer tubes, while the middle tube contains 3.8 m 3 /h of O 2 and 1.8 kg/h of fumed silica powder. Table 1 shows the analytical results.
TABLE 1 Impurity levels in the product produced in the respective examples and of the SiCl 4 used, in ppb, determined using ICP/MS. Ex. Cu Fe Ti Al Ca Mg Na K Ni Cr Li 1 <1 22 2 24 54 9 8 5 2 2 <1 2 <1 10 <1 10 11 2 4 1 <1 <1 <1 3 <1 25 2 31 64 11 11 5 2 2 <1 4 <1 10 <1 9 13 3 5 1 <1 <1 <1 5 <1 12 <1 15 14 3 6 1 <1 <1 <1 6 <1 250 4 63 15 7 7 2 43 27 <1 C7 4 730 <1 62 66 134 19 9 167 235 <1 SiCl 4 <1 10 <1 3 8 <1 3 2 <1 <1 <1 | Use of a flame hydrolysis apparatus for preparing fumed silica particles or a plasma torch apparatus for sintering fumed silica particles to fused silica particles is capable of producing highly pure silica with non-silicon metal impurities less than 500 pb, when at least an inner nozzle is constructed of a silicon-containing material having a low level of non-silicon metal impurities. Preferably, all surfaces in the respective apparatus which contact silica are of similar construction. The silica contains a low level of impurities as produced, without requiring further purification. | 2 |
RELATED APPLICATION
This application is a continuation-in-part of original patent application Ser. No. 283,620, filed July 15, 1981 and now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to an electronic apparatus for a precise determination of the technical parameters of machines, in particular, agricultural machines and other vehicles before the actual design of such machinery. The determination is based on use-value parameters.
Throughout the world, design engineers are confronted with increasingly intractable problems in the design of mechanical equipment so as to optimize the equipment with respect to the technical and economic parameters indicating the effectiveness, capacity, and technological operational safety. The problem is exacerbated by the ever increasing numbers of these parameters, which can be collected only with difficulties and wherein the analysis thereof is also wearisome, as well.
SUMMARY OF THE INVENTION
This apparatus was created on the basis of theoretical studies and has as its object the automatic determination and display of the technical parameters of a machine to be designed, taking into account the requirements particularly of an agricultural machine or other such vehicle.
The apparatus can be advantageously used in the design of other equipment in any field of modern mechanical engineering.
The apparatus representing the object of the invention comprises electronic units not having been known or published up-to-now; the experiments relating to the process were carried out in the practice with the best results.
The natural endeavor to produce better and more efficient products than those already existing, will succeed when the existing machines can be characterized by parameters suitable for value judgement and comparison, and the technical parameters of the product to be designed can be coordinated. In order to be able to perform the comparison, prior to the determination of the design of a new construction, the data relating to existing products have to be collected and analysed. On the basis of this analysis the technical parameters of the new product, yielding a higher use-value than the previous ones, can be established.
The task requires selecting about 30 to 40 parameters of each of the known 20 to 30 machines. Up to now, neither an adequate method, nor an automatically operating machine has been developed for performing this task. For performing the innumerable calculations, known computers or calculators may be used; however, due to the labor intensity, such calculations have not been performed generally, or might be performed superficially only.
At the same time the necessity of performing individual calculations imposes an ever increasing burden on the technical designers of mechanical systems. Accordingly, there is a demand for methods facilitating the performance of routine work, and for apparata for the automatic performance of the foregoing task.
An object of the invention is to provide an apparatus applying and perrforming mathematically calculations for the staff of factories dealing with technical development, which staff is able to analyze the effectiveness, parameters and indices of use-values of the known machines performing identical or similar functions, as the machine to be produced. Furthermore, the apparatus should be able to employ the indices of use other than system parameters with a theoretically acceptable margin of error, and concurrently to perform automatically the analysis and synthesis of the indices of value to yield the constructional parameters of the machine to be designed.
The invention will be better understood by reference to the more detailed description below, with reference to the drawings in which:
FIG. 1 is a perspective view of a line or character printer connected to apparatus of the invention;
FIG. 2 is a perspective view of the apparatus;
FIG. 3 is a view of the main keyboard;
FIG. 4 is a front view of the printer of FIG. 1;
FIG. 5 is a view of a digital display;
FIG. 6 is a top view of the apparatus;
FIG. 7 is a view of the parameter keys;
FIG. 8 is a view of the data-entry and control block;
FIG. 9 is a schematic diagram of the logical connections of the apparatus according to the invention;
FIG. 10 is a flow chart describing operations of modules, and basic programs of the apparatus;
FIG. 11 is a schematic view of the construction of the apparatus;
FIGS. 12/a and 12/b are circuit diagrams respectively of a timing generator and of a supply unit of the apparatus;
FIGS. 13/a and 13/b are circuit diagrams respectively of a keyboard and a LED unit for error indication;
FIG. 14 is a circuit diagram of a CPU and an arithmetic processor.
FIG. 14/a shows a set of peripheral interface units for connection with the CPU;
FIG. 14/b shows the daigram of storage units of the apparatus;
FIG. 15 is a scheme of interconnection of the main units of the apparatus;
FIG. 16 is a flow chart of computation of the basic Cη (C-eta) function;
FIG. 17 is a flow chart of computation of a tendency function and the function of leading standards;
FIG. 18 extends over two sheets of drawings and comprises FIGS. 18/a and 18/b which constitute a flow chart of computation of a tendency function in a subroutine;
FIG. 19 extends over three sheets of drawing and comprises FIGS. 19/a, 19/b, and 19/c which constitute a flow chart of computation of the function of leading standards in a subroutine;
FIG. 20 is a flow chart of determination of the coefficients used in the regression function;
FIG. 21 is a flow chart of determination of functions of two variables;
FIG. 22 is a flow chart of determination of a special function of one variable;
FIG. 23 extends over five sheets of drawing and comprises FIGS. 23/a-e which constitute a flow chart of determination of the use-value function;
FIG. 24 is the flow chart of determination of a limiting function; and
FIG. 25 extends over four sheets of drawing and comprises FIGS. 25/a-d which constitute a flow chart of determination of characteristic Z-values.
DETAILED DESCRIPTION
The apparatus of the invention permits the design and construction of machines, such as agricultural machines, and other vehicles to be described by various parameters and indices in precise numerical fashion for determining objects of the construction. The apparatus of the invention contains electronic elements operating in accordance with predetermined programs incorporating functional relationships and tabulated information, which operation may be accomplished by microprocessors in conjunction with storage and other data-handling equipment.
With reference to FIGS. 1-9, the operation and structure of the invention is described now in a general fashion, with further details to be provided herinafter. As is shown in FIG. 2, the apparatus of the invention is enclosed in a comprehensive housing 1 and comprises a parameter base module 2, an analyzer 3, a synthesizing unit 9, a norm storing unit 11, a norm processor 12, a memory 10 and a design module 17. A line or character printer 22 (FIG. 1) is connected to the electronic apparatus.
The operation is accomplished with the aid of equipment incorporated in the apparatus, the equipment including a parameter base module 2 operative with a set of a number, n, (for example, 25) of parameters which characterize the product to be constructed. With respect to such characterization, the product is understood to be similar to a comparable product previously produced, with the characteristics being set forth on a numerical board, and described by electric signals. The equipment further includes an analyzer 3 which performs mathematical correlations among the parameters of the foregoing set. The electrical elements and the microprocessor in cooperation with a processing module 12 interpolate among the data to calculate such ones of the parameters which have not been determined numerically in advance, this being accomplished with the aid of norms and patterns of data which have been previously stored in a storage unit 11. The equipment utilizes a magnetic disk storage memory 10 which is able to receive and store both input parameters as well as values of parameters which have been calculated. In addition, a synthesizing module 9 operates with the input parameters and those subsequently calculated and stored in the memory 10 to develop mathematically correlations among the parameters by a sequence of mathematical steps, the calculated correlations being stored with the stored parameters. The results of these calculations are indicated by electric signals.
The equipment further incorporates an electronic design module 17 which is controlled by microprocessors, and which is able to display the numerical values of the foregoing parameters in accordance with a scheme in which the parameters represent the same quality, quantity and indications as done in the parameter base module 2. Also included is a printer 22, responsive to a microprocessor and the electrical elements of the units 2,3, 11, 12,9, 10, and 17, and being responsive to signals provided by the keys 36 of a keyboard 37 and control switches 38, 39, 40, 41, 42 and 43, for presenting data of the foregoing parameters. By cooperation of the respective tasks of the units 12, 3, 9,17, and 22, the object of the construction based on the display of the parameters and correlations is presented by the display 18 and on sheets 30 imprinted by the printer 22.
The invention is further characterized in that the units 2, 3, 9, 10, 11, and 12 for developing the desired relationships are arranged in a common housing while the printer 22 is disposed in a separate casing. The module 2 which feeds the foregoing n parameters comprises sections containing ten elementary numbers, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0 as well as a green signal lamp 16 and a keyboard 13 having a key with the marking "+".
It is also noted that in the electrical elements of the analyzer module 3, the module being controlled by microprocessors, the functional values of seventeen mathematical correlations based on a standardized format are provided. Also, the storage unit 11, storing the norms of data used in evaluating the design of the machinery, and the module 12 processing the norms operate on a program based on a standardized format. It is further noted that the memory 10 contains the parameters describing the goal or object of the construction project, and further stores the norms and the mathematical algorithms and programs which are to be fed into the processing module 12 and the synthesizing unit 9 for further processing.
The analyzer 3 is provided with a numerical board 4 for the display of values of the parameters in a standardized format, the analyzer 3 further including switching and key elements 5, 6, and 7 which indicate acceptance, cancellation or correction. The storage unit 11 and the processing module 12 are provided with colored lamps 23 and 24 which indicate the state of readiness for service and operating state, respectively. A data-entry and control block 32 enables the feedback of auxiliary data to the units 11 and 12. A lamp 33 with a red ring indicates a request for further information, an orange lamp 34 indicates safe operation, and a lamp 35 having a green ring which is incorporated into a switch indicates the resultant outputs of the processing module 12. Also included are operative keys 36 for entering commands for the program which has been fed into the processing module 12 as well as keyboard 37 which incorporates a set of the operative keys 36.
Further features in the operation and construction of the invention are as follows. The memory 10 is provided with keys 14B for feeding in numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0 with keys 14A having different letter markings, with a key 14C having a blue lamp for indicating automatic operation, a key 14D associated with a yellow lamp for indicating operational safety, and also a switch 14E associated with a green ring for insuring operation. With respect to the synthesizing unit 9, the mathematical program utilized therewith is suitable for forming the vectorial surfaces function of a machine system, this being accomplished with the aid of the microprocessors, whereby a so-called tendency curve may be calculated as a function of time. In the synthesizing unit 9, there is a lamp 26 associated with a green switch for indicating the operation of the orange lamp 25 in the signalling of readiness for service. Further keys 41 and 42 provide instructions for providing surface functions and a difference of parameter values, respectively, with a key 45 directing the production of the tendency curve. The key 38 controls instructions for the object board, the key 39 directing instructions for the printer 22 to print out the object or goal of the construction, while a key 40 controls the plotting of the tendency curve while the key 41 directs the formation of a surface function representation of the output data.
A further key 44 initiates operation of the apparatus and another key 45 terminates the operation of the apparatus. The module 17 which displays the object of the construction comprises a set of parameter displays and numerical displays corresponding to the parameters fed by the base module 2, the numbers being displayed in four or more digits. There is also a red or blue flashing light 20 indicating failure and a green signal indicating the end of the operation. The apparatus may be activated with alternating or direct current from a dource of electrical power, Alternatively, the source of electric current may be a galvanic element or D.C. batteries. It is also noted that the base module 2, the analyzer 3, the storage unit 11, the processing module 12, the synthesizing unit 9, the memory 10, and the design module 17 may be formed and arranged in such a manner so as to permit their connection and disconnection from the housing 1, and furthermore, they may be exchanged and can also be capable of independent operation.
The apparatus according to the invention operates as follows:
The operator enters numerical values of and features of the selected machines by means of the parameter base module 2 (FIGS. 2, 6). These features and parameters are, by way of example for an agricultural machine the following:
season's length, gross;
grade of characterization;
technical operational reliability;
substituted manual labor power;
quality of work;
specific price;
mass;
independence on weather;
readiness for operation;
required level of stored components;
energy requirement in idle running;
corrosion resistance;
energy requirement during work;
technological operational reliability,
safety of work (prevention of accidents);
output;
width of work;
value of appearance;
season's length (net);
readiness for service;
number of operators,
height;
fineness of processing;
number of the constructional drawing; and
year of manufacture.
The foregoing parameters in proper dimensions are entered by the operator into the apparatus by using the appropriate keys, and the parameters are forwarded into the analyzer 3. In case any of the parameters are not defined by the operator, such situation is indicated by the red signal lamp of the block not pressed, the key 13 (with the marking X) of the key-block corresponding to the missing parameter is to be pressed down (FIG. 6, 7), In this case the apparatus gives a signal for the storage unit 11. This unit contains the value programs of the norm correlations which enable the processing module 12 to select a norm and parameters which are to be calculated with the aid of the effective parameters already fed into the base module 2. This enables the determination of the missing parameter. Accordingly, the storage unit also stores different algorithms for determining the missing values.
In such case necessary data may be fed by pressing the corresponding keys 36 of the data-entry block 32 (FIGS. 6, 8). By using the keys 36, the numerical values of the various kinds of input data including their norms represented by four-place numbers may be fed into the apparatus.
When the lamp 33 lights up the block 32 of the module 12, the operator feeds the supplementary information into the numerical keys of the keyboard 37.
Illumination of the lamp with the green ring indicates that the supplementary norm values calculated by the module 12 (FIG. 6) can be fed into the memory 10 and the analyzer 3 by pressing down the key X. The lamp 34 (FIG. 8) indicates the operational safety of the module 12 with orange light. After entering all data and parameters into the parameter base module 2, which entry is indicated by the light of all the green lamps of number n, the analyzer 3 begins processing and calculates the required functions, which in the case of agricultural machines comprises the seventeen correlation functions.
By means of the values of the parameters fed into the apparatus and by the aid of the function recorded therein, the analyzer 3 calculates a characteristic value designated by Cη based on a related machine, and displays the value on the board 4. The value can also be forwarded to the printer 22 (FIGS. 1, 4) and the synthesizing unit 9. The synthesizing unit 9 performs integration, analysis, and synthesis with the corresponding characteristic values of the proposed machine, and forwards the values obtained into the central memory 10, as well as to the units 17 and 22 of the apparatus.
By repeating this process, the operator obtains the individual values for the utilization of several or more machines by entering the requisite data into the synthesizing module 9 and the memory 10. The process is implemented by means of the keys designated A-C-E-G-I-B-D-F-H-K +/-/ located on the board 14 (FIGS. 2, 3, 6) for commanding the following procedures:
A recording
B correction
C cancellation
D change of the routine
E summing up with the value indicated on F
G directing outputs towards the specific units of the apparatus.
The purpose of the repetition of the process is the calculation by the apparatus of individual values of Cη for several machines. The values obtained are forwarded to the synthesizing unit 9 by pressing the key 7. The synthesizing unit 9, if it is in an unloaded state, indicates, via the orange lamp 25, a state of readiness for operation. The lamp 24 with the green ring indicates that the synthesizing unit 9 is performing synthesis. The middle part of the ring of lamp 26 is formed by a press-button; when the operator presses down said button, the Cη values which were introduced into the synthesizing unit 9 via the key 7 are synthesized and evaluated.
Synthesis is performed by the synthesizing unit 9 activated by a microprocessor, in accordance with the predetermined program having a multistage process, as shown in FIG. 10. The single steps are actuated by the keys 38-43, in the following manner:
The actuation of the key 38 applies the instruction, for the parameters of the machine to be designed for the given year. The resulting output of the synthesis is displayed numerically on the design module 17, as well as on the digital display 18 (FIGS. 2, 5, 6).
By actuating the key 39, the instruction is given for the appearance of the parameters for the given year on the printer 22.
The key 40 gives the instruction that a tendency curve C, a function of time, and the use-value should appear on the printer 22.
The key 41 gives the instruction for the synthesizing unit 9 to form the surface function of leading standards defined by all values Cη and to print it numerically by the printer.
The key 42 gives the instruction for the printer to print digitally the differences between the single values and the evaluating surface function for all the machines, in absolute and relative values.
The key 43 instructs the printer 22 to print the numerical values of the Cη tendency curve for the period of time between the years 1930 and 1985, by way of example.
In such manner the task set for the apparatus can be acheived. A single operator is able to perform several thousands of calculations within one hour, while the apparatus is producing the numerical values, which are to be set as a goal for the construction of the machine. The apparatus is put into operation by pressing the main switch 44, while it is put out of service by pressing the button 45.
Further details on the construction and operation will now be provided with reference to further ones of the drawing figures.
The parameter base module 2 is the central unit of the device and comprises a microprocessor 56; the analyzer 3 comprises an arithmetic processor 62. Other elements not indicated on the drawings do not require a detailed description for an understanding of the invention.
FIG. 9 illustrates the main logical interconnections within the device, giving an overall understanding of the functions of the apparatus of the invention.
The thick line (Input) indicates that entering information arrives at the parameter base module 2 and at processing module 12. The logical sequence of operations is shown by a flow of arrows in FIG. 9, which flow (as this is a logical-sequence block diagram) differs from the hardware block diagrams to be shown in FIGS. 11 to 14b. Nevertheless, the operation set forth in FIG. 9 conforms to that of the hardware shown in FIGS. 11-14b. The design module 17 presents the final results of all the calculations, namely the main design characteristic of a new machine or equipment. In the block diagram of FIG. 9 broken and continuous thin lines indicate the intermediary data of internal logical functions determined by the program.
FIG. 10 discloses a flow in chart for identification of modules and programs of the apparatus of this invention, the chart describing the following operational steps.
After reading in the input data, replacement of missing parameters will take place, the parameters being then generated by normalization of other data and parameters. After this and by using the parameters thus established, the device will display (on screen on printer 22 as desired) the coefficients of a tendency function and of the leading standards, having determined, displayed and stored previously the use-values. The possibility of determining and displaying the characteristics of a unit to be designed exists, too. The replacement of missing parameters by normalization of data based on practice and experience will ensure that the analysis can be performed in each case.
FIGS. 11-15 show the components of the microprocessors and various units of the apparatus of FIG. 2, including their interconnections. The details of the construction of the invention as set forth in FIGS. 11-15 will now be described.
FIG. 11 shows the essential set-up of the device. A microprocessor 56, such as the commercially available tye Z80, is used for controlling the system's operation. The microprocessor 56 interprets the commands, addresses the memory locations, and controls the peripheral units. Connections are made by eight data bus lines 96 designed D.0. to D7, sixteen address bus lines 98 designated A.0. to A15 and fourteen command lines 100. The data bus lines 96 shift the memory contents between the individual subunits. The program is burnt-in in an EPROM memory element 80 comprising a RAM section 78, this program effects--by using the subunits of the device--the determination of use-values searched. The RAM section 78 accomodates the working (operational) storage elements while the program is running. Input data (the parameters) are read into these, and the program deposits output data here, too, so they can be recalled from here if required.
The address bus lines 98 and the data bus lines 96 are connected to the EPROM element 80 and RAM element 78 to arithmetic microprocessor 62, and to peripheral interfaces 70, 71 and 72 of e.g. connected RAM element 78 to the arithmetic Z80 PI01 and Z80 PI03 type, respectively. The command lines 100 serve for controlling the entire device.
System control is effected by the symbols M1, MREQ, IORQ, RD, WR, RFSH, while the symbols HALT, WAIT, INT, NMI, RESET are used for controlling the CPU. BUS lines are controlled by the symbols BUSRQ and BUSAK. The command lines 100 run to the microprocessor 62 and to the peripheral interfaces 71, 70 and 72.
On the address bus lines 98 the microprocessor 56 selects those addresses which correspond to program steps in the EPROM 80 and to memory addresses in the RAM 78, and it will also select the peripherals 70, 71, 72, which should become effective. The data bus 96 and the address bus lines 98 are directly connected to the arithmetic microprocessor 62. The arithmetic microprocessor 62 performs those mathematical operations which are selected by the program for the proper calculation of the algorithm. The command lines ensure the joint working of the individual subunits. Command impulses originate in the microprocessor 56 and terminate there, as well:
For entering input data keys are to be used. Visualization of intermediary and final results of computation is effected by a display. For printing the results in tabular forms, for printing and plotting the functions determined, the printer 22 can be used.
FIG. 12 shows the circuit plan of two subunits. The device's clock generator (FIG. 12/a) comprises a quartz crystal oscillator 108 generating a circuitry basic signal of 12 MHz frequency and an output inverter 114. The quartz crystal oscillator 108 is connected to a output of an inverter 104 and to the input of another inverter 102 both connected to a 1.5 nF condenser 103. Parallel to inverters 102 and 104 there are two 330 ohm resistors 106. The common point of the oscillator 108 and the inverter 104 is connected to the input of an inverter 110, the output of which is connected to the jointed inputs 01 and 014 of an BCD counter 112 e.g. of 7492 type. Outputs 06, 07, and 010 of the BCD counter 112 are connected to ground. The BCD counter 112 is connected to the input of another inverter 114, the output of which is connected to the collector of a transistor 116 of N2905 type. The emitter of the transistor 116 is connected to voltage +5 V. Between the emitter and the base of the transistor 116 and between the base and the input of inverter 114 there are two resistors connected in series.
The output signal of the inverter 110 is brought to the BCD counter 112 acting as divider, which by dividing into two provides on its output 3Q, 6 MHz signals and then, by dividing into three, 2 MHz signals on output Q. For purposes of separation and signal shaping, the output of the BCD counter is connected to the inverter 114 and thereby to the transistor 116 for carrying out signal shaping.
The task of the power supply unit (FIG. 12/b) is to generate stabilized direct current at voltages of ±5 V and ±12 V, wherein +5 V serves to energize the integrated circuits. Current surges are attenuated by an inductance 118. The arithmetic processor 62 requires (FIG. 11) +12 V DC voltage which can be supplied by this same circuitry.
The basis of this unit is an integrated supply circuit 120, preferably of μA 78 SK.0. type. The outputs i13 and i14 are connected to a resistor and the output i13 is connected to the +5 V DC power supply. Output i14 is connected in series with the inductance 118, with a 47 μF condenser 121, and with the cathode side of a diode 105. The anode of the diode 105 supplies the -5 V DC-power for further units. The output terminals i9 and i8 of the circuit 120 are joined and led to ground, via a 22 μF capacitor 123 while output terminal i10 goes via an RC-element to the ground, and also provides, through another RC element, the +12 V voltage. A back-biased protective diode 107 is connected between this source of 12 V and the inductance 118. The output terminal i11 of the circuit 120 is directly on the ground. The output terminal i12 is grounded via 1 μF capacitor 119. Output terminal i3 is connected both to the base of the transistor 122 and via a 120 ohm resistor 127 to the ground. The emitter of the transistor 122 is connected to ground, while its collector is connected to the inductance 118. Between the emitter and the collector of the transistor 122 there is a diode connected in forward direction. The cathode of the diode 107 is connected to a series of condensers 124.
FIG. 13 shows the keyboard's switching arrangements (FIG. 13/a) and an LED indicator. The +5 V voltage originates from the power supply unit of FIG. 12/b. The keys are of the Hall generator type.
The keyboard has two outputs and a total of 24 keys. There are numeral and function keys only. One of the outputs of keys signed by 7, 6, 5, 4, 3, 2, 1, .0. is connected to the encoding D.0. output of an encoder circuit 126. One of the outputs of keys signed by NAT, TN, DY, PR, NT, IN, 9 and 8 is connected to the D1 output terminal of the circuit 126, while the keys signed by PAS, Cη, RES, ST, GO, MEM, ",", "." have one of their outputs connected to the D2 output terminal of the circuit 126. The other outputs of these keys are connected in groups of three keys, as shown in FIG. 13/a, to respective outputs D7 . . . D.0. of an encoder 125, e.g. of type 74LS151. On the other side outputs of keys are connected--via a 1 kOhm resistor 129 to +5 V voltage source. Signals B.0., B1, B2, B6 arriving from the CPU microprocessor 56 as shown in FIG. 14 and originally select the vertical coordinates of the keys, aided by the encoding circuit 125, while signals B3, B4 and B5 also arriving from the microprocessor 56 select the horizontal coordinates of the keys, aided by the encoding circuit 126 which may be also of 74LC151 type.
Errors occuring are indicated by a LED 101 (FIG. 13/b). The LED's control comes from a circuit of FIG. 14 in form of signals D.0., D2, and D7, via an OR circuit 99. The diode's cathode is connected to the ground, through a resistor 97.
FIG. 14 shows the structural interconnections of the microprocessor 56 and of the arithmetic processor 62. Signals of the microprocessor 56 include sixteen ADDRESS lines, designated A.0. to A15. Due to weak power, the signals cannot be used directly and must be led through inverters 58. Address lines A.0. to A15 are connected to the inverters 58. Following the inverters 58, the signals have new designations as BA.0. to BA15.
The output signals of the inverters 58 are as follows:
BA.0. is connected to the C/O input of the arithmetic processor 62 and to the A.0. inputs (a total of 12 inputs) of the storage units shown in FIG. 14/b.
BA1 is connected to input A of an encoding circuit 60, and to the total of twelve A1-inputs of storage units shown in FIG. 14/b.
BA2 is connected to input B of the encoding circuit 60, and to all A2-inputs of storage units shown in FIG. 14/b.
BA3 is connected to input C of the encoding circuit 60, to all A3-inputs of storage units shown in FIG. 14/b, and to inputs A of a circuit 76 e.g. of 74LS138 type shown in FIG. 14/a.
BA4 is connected to all A4-inputs of storage units shown in FIG. 14/b, and to inputs B of the circuit 76 shown in FIG. 14/a.
BA5 is connected to input G2B of the encoding circuit 60 to all A5-inputs of storage units shown in FIG. 14/b, and to inputs C of the circuitry 76 shown in FIG. 14/a.
BA6 is connected to input G2A of the encoding circuit 60 to all A6-inputs of storage units shown in FIG. 14/b, and to input G2A of the circuitry 76 shown in FIG. 14/a.
BA7 is connected to input G1 of the encoding circuit 60, to all A7-inputs of storage units shown in FIG. 14/b.
BA8 is connected to all A8-inputs of the storage units shown in FIG. 14/b.
BA9 is connected to all A9-inputs of storage units shown in FIG. 14/b.
BA10 is connected to all A10-inputs of storage units shown in FIG. 14/b.
BA11 is connected to inputs B of a circuit 82 and to inputs A of a circuit 84, shown in FIG. 14/b.
BA12 is connected to point C of the circuits 82 and 84 shown in FIG. 14/b.
BA13 is connected to input G1 of the circuit 82 and to input G2A of the circuitry 84 shown in FIG. 14/b.
BA14 is connected to the input of the AND-gate 88 shown in FIG. 14/b.
BA15 is connected to the input of the AND-gate 88 shown in FIG. 14/b.
In addition, signals A.0. to A7 serve for addressing interface circuits of the peripherals 70, 71, 72 shown in FIG. 14/a.
Signals A.0. to A7 of the microprocessor 56 are connected according to FIG. 14/a to the lines of signals A.0. to A7 of the perpherals 70, 71, 72.
Signals BA3, BA4, BA5 and BA6 serve for definite selection of circuits 76 for the range CE1 to CE5.
Signals BA1, BA2, BA3, BA5, BA6, BA7 proceed to the encoding circuit 60 shown on this same figure, and thereby the arithmetic processor 62 is selected. Address signals BA.0. to BA15 will control the addresses of memory units shown in FIG. 14/b. Signal BA.0. determines directly whether an instruction or data will follow for the arithmetic processor 62.
Data lines D.0. to D7 create direct connections to the arithmetic processor 62 shown in FIG. 14.
As data lines (or a data bus), D.0. to D7 are connected to peripheral interfaces 70, 71 and 72 as shown in FIG. 14/a and to the storage units shown in FIG. 14/b.
The lines D.0. . . . D7, respectively, are connected to following output terminals: DB.0. . . . DB7 of the arithmetic microprocessor 62, D.0. . . . D7 of the circuits of peripherals 70, 71, 72, shown in FIG. 14/a, D.0. . . . D7 of the EPROM element 80 as shown in FIG. 14/b, and DQ.0. . . . DQ7 of the RAM element 78.
Passing through an inverter 58, signal M1 acquires the new designation of BM1 and controls at the M1-inputs the interface circuits of peripherals 70, 71, 72 shown in FIG. 14/b. The signal IORQ, on the one hand, puts to stand-by the writing WR and reading RD functions of the arithmetic processor 62, after passing through encoder 64, on the other hand it goes to the input G of the encoder 64 in response to the RD and WR control signals of the microprocessor 56. The signal RD passes to the B-input of the encoder 54 and to the input of the inverter 58, and the signal WR passes to the A-input of the encoder 64 and to the input of the inverter 58.
Clock signal Q arrives from the clock generator (FIG. 12), from the inverter 114. As CLK clock signal this same signal is gated through an inverter 66. CLK is the timing signal (pulse) for the arithmetic processor 62.
The RESET signal puts each of the circuits to its basic state. The RESET signal originates at the RES key shown in FIG. 13. The WAIT signal is processed in the circuit shown in FIG. 14. It has a relationship with the PAUSE signal of the arithmetic processor 62 and is connected to it.
The INT signal has a relationship with the END output shown in FIG. 14, which indicates the termination of operations in the arithmetic processor 62 and is connected to the circuitry thereof. The INT signal has a further connection with interface circuits of the peripherals 70, 71, and 72 connected to their INT-inputs.
As shown in FIG. 14/a the CE1, CE2, CE3 signals produced by an encoding circuit, such as 74LS138 type, are connected to signals CE1, CE2, CE3 of the peripherals 72, 70, 71, respectively.
The E-signal of gate 74 is connected to the E-signal of the peripheral 70 and the IE11-signal is connected to the IE11-signal of peripheral 72. As shown in FIG. 12, the output of the inverter 114 is connected to the Q-signal of the peripherals 70, 71, and 72, all three shown in FIG. 14/a.
In FIG. 14 the RD-signal of the microprocessor 56 is connected to the RD-signal of peripherals 70, 71, and 72, all three shown in FIG. 14/a.
FIG. 15 shows the interconnections of the microprocessor 56, the arithmetic processor 62, the EPROM element 80, containing the program and the RAM element 78 which serves as working storage (accumulator).
The operation of the microprocessor 56 and the arithmetic processor 62 will now be explained with reference to the flow charts of FIGS. 16-25.
FIG. 16: After entering the parameters of the machine to be assessed, the Cη (also referred to as C-eta) program (FIG. 23) will compute the value of C-eta, the output being the C-eta, the x, y, z and N o values which are loaded into the storage and are printed by the printer.
FIG. 17: After START, the TEND program processes the basic data available in the storage (C-eta, x i , y i , z i , N o i ) and compute the tendency function (FIG. 18), the output being parameters m1 to m6.
After checking, a further TEND-computation produces the final values for the m1 to m6 parameters.
Using the m1 to m6 parameters and the "n", "x", "y", "C" values, the NAT program (FIG. 19) calculates the required characteristic values.
In FIG. 18--the subroutine for determining tendency functions, which--by using function F--produces the correlation coefficients for 13 probability variables, and--aided by the SORT routine--sorts these according to their absolute value. The probability variables corresponding to the 6 highest values thus obtained will form the basis for an EG-routine in producing the coefficients m1 to m6.
In FIG. 19--the subroutine for determining the function of leading parameters, will--by using function G--produce the correlation coefficients of the 13 probability variables, and--aided by the SORT routine--sorts these according to their absolute value. The probability variables corresponding to the 6 highest values thus obtained will form the basis for the EG-routine in producing the coefficients m1, m2 . . . m6.
In FIG. 20--the subroutine for determining the coefficients of the regression function helps in producing a C matrix, and using this, in determining a D matrix, which is promptly inverted. After this, the quotients of corresponding matrix elements will provide the coefficients of regression.
In FIG. 21, use is made of the function G which is designed for producing functions of two variables. The G function is used to produce the probability variables required for determining the two-dimension function of leading standards. The basis for performance of this function is provided by the value of a parameters j changing from 1 to 13.
In FIG. 22, with function F designed for producing functions of one variable, it is possible to produce the probability variables required for determining the tendency function. Basis for doing this will be provided by the value of a parameter j changing from 1 to 13.
FIG. 23 shows a routine for determing C-eta use-value. On the basis of appropriate input data, the routine determines the corresponding elements of matrix A having four columns. The first column of matrix A contains the parameters arranged according to an appropriate system, while the elements X of the second column of the matrix can be obtained from the first column by using the XYKE-functions. A third column of the matrix having elements Y is produced by multiple application of the XYKE-function and finally, the fourth column having elements Z is obtained by using the ZKE-function. Thereafter, upon summing the elements X, Y, and Z in each of the respective second, third, and fourth columns of the matrix, the coordinates of the vector of use-value are obtained. The absolute value of this vector gives the C-eta use-value. This subroutine comes to halt after displaying the results.
FIG. 24 describes a routine for the limitation of the X and Y values. On the basis of parameters this function produces the boundary values of X or Y.
FIG. 25 describes a routine for determining values of Z. On the basis of (k)-parameters and of the SIGN parameter the routine produces the Z coordinate for the components of the utility value's vector, based on a set of theoretically supported relationships. The result obtained is already corrected according to the foregoing boundary value. The program compiled in accordance with the method described in FIGS. 18 to 25 will completely execute the operations disclosed in FIG. 10. Results obtained are displayed on the screen, and will also be printed if required. The program's machine code list may be found in the attached appendix.
With reference again to FIGS. 11-15, the block diagrams describe generally the operation of the device of the invention. Primary control for the device's operation comes from the microprocessor (such as the commercially available type Z80) 56 which serves as CPU. This CPU is provided as an 8-bit, 40-pin IC-capsule. Power requirements: maximum 1000 mW. Operating voltage: +5 V. Maximum clock signal frequency is 4 MH z . Set of instructions is as follows.
______________________________________Inner registers of the CPU:Main register block Auxiliary register block______________________________________A 8 F 8 A' 8 F' 8B 8 C 8 B' 8 C' 8 GeneralD 8 E 8 D' 8 E' 8 purposeH 8 L 8 H' 8 L' 8 registersI8 R7 I X 16 Special I Y 16 purpose S P 16 registers P C 16______________________________________
The register block consists of two parts:
the block of general purpose registers
the block of special purpose registers
The block of general purpose registers is further divided into two sections, the block of main registers and the block of auxiliary registers. Operations can be directly performed only by the main registers, however the contents of the registers (both main and auxiliary) can be exchanged for each other by way of an instruction.
A and A' accumulator (8-bit)
F and F' marker bits (8-bit)
B, B', C, C', D, D', E, E', H, H', L, L' are 8-bit general purpose registers
The B, C; D, E and H, L pair of registers can also be used as 16-bit registers.
I--IT register of sheet address (8-bit)
R--Refresh register (7-bit)
IX; IY--Index register (16-bit)
SP--Stack pointer register (16-bit)
PC--Program counter (16-bit)
In the second IT mode the I-register will provide--after accepting the IT--the address bit of the upper 8 digit position memory of the address to be performed. The Refresh Register holds the actual refresh storage address which will be incremented in all instruction demand (recall) cycles. The Index Registers hold the basic address of the usual index register addressing.
The general purpose registers will be used for temporary storage of instruction and data addresses when performing mathematical operations.
The microprocessor 56 communicates with its environment by the address bus 98, the data bus 96 and the command lines 100.
The address bus lines 98 are tri-state output terminals with an active high level; in case of memory writing and reading the A.0. to A15 lines will establish the actual address of the memory.
In the refresh cycle the A.0. to A6 lines establish the actual refresh address.
In periphery addressing the A.0. to A7 lines become effective in selecting activity in the arithmetic microprocessor 62. For this activity selection, the separate encoding circuit 60 can be used.
The control pulses of the microprocessor 56 are as follows (FIGS. 14, 14/a, 14/b):
If BUSAK=.0., the lines A.0. to A15 will have a high impedance (floating state).
The data bus lines 96 are two-way tri-state data lines with an active high level. When RD=.0. or if reading an IT-vector, then the bus has an input state, and when WR=.0., then an output state; and if BUSAK=.0., then it has a high-impedance floating state. The data bus is connected to all programmable units, i.e. the EPROM element 80, RAM element 78, arithmetic microprocessor 62 and peripherals 70, 71, 72, storage units excepted, because the program instructions in addition to data traffic travel along these lines to the units.
The command lines 100 forward from the microprocessor 56 the required operation commands for the controlable units connected to it (peripherals 70, 71, 72 and arithmetic microprocessor 62).
M1 (machine cycle 1): Output on an active low level (40 W).
When machine instruction codes are recalled and when an IT is acknowledged, then M1=.0..
MREQ (request for memory): Tri-state output on an active low level. Its active state with MREQ=.0. indicates that the address lines 98 can effect reading or writing of memories; the third state is activated also by BUSAK=.0..
IORQ (request for input-output): Tri-state output on an active low level. Its active state IORQ=.0. indicates that the I/O addresses are effective. IORQ=.0. and M1=.0. indicates IT-acknowledgement.
WR: Tri-state output on an active low level. Its active state with WR=.0. indicates that the data to be transferred into the memory or to the periphery are effective on the data line of the microprocessor 56.
RFSH (refreshing): Output with active low level. Its active state with RFSH=.0. indicates that on the bottom 7 address lines 98 of the microprocessor 92 the memory refreshing address is effective. In the second half of each M1-cycle it has an active state (the 7 bottom address bits are incremented for each M1-cycle).
HALT: Output with active low level. Its active state HALT=.0. indicates that the microprocessor 56 performs a HALT-instruction. From this state restart of the microprocessor56 can be effected by a break request or a HW-Reset (RESET=.0.). The HALT state of the microprocessor 56 is "dynamic" which means that in the HALT state the microprocessor 56 performs a separate cycle for the duration of refresh.
WAIT (waiting): Input with active low level. Its active state with WAIT=.0. may indicate that the storage or the peripheral unit is not ready and requests some waiting from the microprocessor 56. Sampling of the WAIT signal is done in each T2-step at the .0. diminishing edge. The WAIT input can be used for synchronizing the microprocessor 56 with slow memories and periphery units.
INT (request for interruption): Input with active low level. Its active state INT=.0. generates a request for interruption, if the IT-request is permitted and if BUSRQ is inactive. Acceptance of an IT-request is indicated by the microprocessor 56 by displaying the signal combination of IORQ=.0. for the unit requesting for the IT.
RD (reading): Tri-state output with active low level. Its active state RD=.0. indicates, that the microprocessor 56 is ready to read data from the memory or from the I/O unit.
NMI (request for a non-masking interruption): Diminishing active input. It has higher priority than INT and cannot be prohibited by way of software. It makes the microprocessor 56 to perform an automatic restart instruction for the .0..0.66 address.
RESET: Input with active low level. By pushing the RES key the normal (i.e. starting) position will be established. This key must not be activated while the program is running except in case of disturbances that cannot otherwise be remedied. Effects of RESET:
1. Erasing program counter
2. Prohibiting the IT-request
3. Erasing the I-register
4. Erasing the R-register
5. Setting the .0. IT mode.
BUSRQ (request for bus): Input with active low level. Its active state BUSRQ=.0. makes the microprocessor 56 to effect the high-impedance state of the address and data buses 96, 98 and of the tri-state command lines 100. For BUSRQ=.0. the microprocessor 56 performs--after ending the running cycle--and sets the high-impedance state of the above mentioned command lines 100.
BUSAK (bus acknowledging): Output with active low level. Its active state BUSAK=.0. indicates that the microprocessor 56 performed the transition of lines to the high-impedance state as requested by BUSRQ=.0., the address bus 98, the data bus 96 and the tri-state command lines 100 can be controlled by external means (e.g. by the DMA-controller).
φ: Single-phase time signal input. The 2 MHz signal comes from the inverter's (114) output. The signal form will be supplied by ZN 2905 transistor (116).
The timing and the basic time signal of the microprocessor 56 are controlled by the 12 MHz oscillator 108 comprising according to the FIG. 12/a the inverters 102 and 104. Signal forming and timing are supported by the 1.5 μF condenser 103 and by the two 330 Ohm resistors 106. For separating the oscillator's output, the inverter 110 is used which plays an additional role in signal formation. For the microprocessor 56 the 12 MHz signal has to be reduced to a 2 MHz signal. This task has been assigned to the BCD counter 112 of 7492 type. For purposes of control and timing, the 6 MHz (3 φ) signal is also forwarded from the output 3Q.
Power supply for the device comes from a 5 V power supply unit (FIG. 12/b). In order to ensure power for the storage units, for the bus lines 98 and for the arithmetic processor 62 a DC-DC converter is used. The input voltage is +5 V±2%, stabilization comes from the circuit 120. The noise reduction inductance 118 prevents the fluctuation of currents. Control transistor 122 has the additional task of overload protection. A set of condensers 124 of value 70 uF are used as buffer for the output voltage.
The keyboard 36 is the input device of the apparatus. The keyboard connects to the system via the peripheral unit 70. The keyboard 36 is subdivided into two sections:
1. Numerical section
2. Intructional section
Encoding of keys in the X-Y plane is done by two circuits/74 LS 151 type/125 and 126. Selection is supported by lines B.0.-B6. Vertical selection is performed by the circuit 125. All eight outputs are utilized. For example, the active signal of the output D7 selects the keys □7, □NAT and □PAS. Selection in the horizontal direction is done by the encoding circuit 126, of which only outputs D.0., D1, D2 are used. The numerical keys 36 serve for transmitting input data and include the key "." (decimal point), which plays a role in the input of fractional values. Functional keys:
IN: By pushing this key that part of the progam is activated which waits for the input data and distributes these data. Input data are transmitted via the input keyboard.
NT: By pushing this key again that part of the program is activated which has to ensure the input operations. On pushing key NT the apparatus waits for the normative data required in computing operations.
PR: This key has to be used only if a printer is connected to the apparatus. Otherwise key PR does not participate in data traffic.
DY: It activates the display mode of operation. If pushed, the data and intermediate results appears on the display used.
TN: This key initiates the routine of trend computation. In effect, the computation of tendency functions starts on the basic of data input. This is of importance if by some reason it is desired to carry out the programme in phases.
NAT: By pushing this key the PC counter points to the start of the program for calculating a characteristic function of two variables. From input data already processed by the TEND program section it calculates the elements of this function which are presented on the display or the printer if keys DY or PR are pushed.
PAS (Pause): By pushing this key the actually performed program is suspended. After suspending restart can be effected by the key GO. The printer is not activated, but the display shows the result of this phase of calculations which is actually in processing. This key is not effective during the running of the arithmetic microprocessor 62.
Cη (C-eta): When pushing this key the running of the entire program will start, using the input data. The running continues to the end or unless an error is found. After pushing key Cη, the keys IN, NT, PR, DY, TN, NAT and the numerical keys will become ineffective. Running of the program can be stopped and suspended by pushing the key PAS or can be interrupted by pushing the key RES.
RES: This key brings both the device and the program back to its starting (basic) state.
ST: By using this key we can perform the program in steps. It should be used for error tracing or if intermediary results are required. The key ST has not effect on the operation of the arithmetic microprocessor 62. (Its operation is considered by the system as one step.)
GO: By pushing this key the running of the suspenced program (commanded by PAS) will continue. The program will continue with the instruction present at this stage in the PC.
MEM: By pushing this key any of the memory addresses can be reached over the numerical keys. In the RAM section 78 the data contents may be changed.
",": By pushing this key the "comma" function becomes active which removes some of the instructions entered previously. Program sections located between commas (",") are not be performed by the system when carrying out a program.
For program storage the use EPROM element 80 can be used, while variable data and calculation results are stored in the RAM element 78. Address lines BA.0. to BA15 serve for selecting storage locations and memory types. For selecting storage locations the address bits BA.0. to BA1.0. are used, while for the selection of memory types the address bits BA11 to BA15 are active. The low level signals BA14 and BA15 are coupled via the AND-gate 88 and the gate 86, used as an inverter to the circuit 82 which, with the help of signals BA12 and BA13 decodes the signals BA14 and BA15 to activate the EPROM.
Data lines are fed from a common data bus 96, or, in turn, supply their data to this data bus. Direction of memory data flow will be determined by the relation of BRD (Read) signals to BWR (Write) signals. Selection of memory circuits is done by the encoding system of circuits 82 and 84.
For performing the mathematical computations, the arithmetic microprocessor 62 has data lines directly connected to the data bus lines 96. Selection control of CHIP is effected by separate encoding circuits 60 and 64.
Power supply of circuits is realized by voltage +5 V and +12 V. As a common external signal serves the φ time signal of 2 MHz, which arrives via the inverter 66, while the two general erasings are initiated by the RESET signal, through the inverter 68.
Principal features of the arithmetic processor 62 are
16-bit and 32-bit fix-point operations,
32-bit floating point operations,
binary data formats,
operations: addition, subtraction, multiplication, division,
trigonometric and inverse trigonometric functions,
power functions, logarithmic and exponential calculations.
The circuit requires external timing which comes via input terminal CLK. With the CLK signals it is possible, to synchronize the control signals RD and WR (reading and writing) too. The main signals controlling the arithmetic microprocessor 62 are:
RESET: This input signal is high and active and serves for initiating the internal circuits. It erases the status register. After a RESET signal the END output receives a high value.
C/D (Command/Date Select): This is an input signal. In combination with the WR and RD signals it determines the way of circuitry operations:
______________________________________ C/--D ##STR1## ##STR2## Function______________________________________L H L Data byte into the stack registerL L H Data byte from the stack registerH H L Feeding-in instruction from data busH L H Reading in a status byteX L L Unspecified______________________________________
END A low level appears on the output when the circuit finished one task assigned to it. The output gets erased and receives a high value if the EACK input receives a low value. The reset signal has the same effect.
EACK (end acknowledge): An output signal. If EACK is low, then the END output can be also low.
SVREQ (service request): An output signal which functions as END. It has an active high level.
DB0-DB7 (bidirectional data bus): There is a bidirectional data traffice (flow) through these 8 output terminals. As an input instruction it receives the instruction bytes. Allocation of bytes is effected by the C/D, WR and RD signals.
CS (Chip Select): An input signal which turns to its low state if the arithmetic microprocessor 62 is selected for operation. The low signal directed and arriving here will ensure that the signals appearing on the bus lines are assigned to this circuit.
RD (read): This is an input signal with active low level. It indicates that the arithmetic microprocessor 62 can send one byte to the bus lines. This byte can be one of a calculated result or one status byte of an instruction (operation) performed.
WR (write): Input signal with active low level. It indicates that there is one byte on the data bus lines 96 for the arithmetic microprocessor 62. In combination with the C/D input it will decide whether this byte receives an instruction, or it will constitute data for the arithmetic microprocessor 62.
PAUSE An output signal. Its task is to maintain the communication with the commanding microprocessor 56. This signal is active low as long as the informations of the operation are not completed. During the waiting period it receives data via the data lines 96 or sends out data. This signal travels directly to the WAIT input terminal of the microprocessor 56.
The central unit of the apparatus, the microprocessor 56 is connected to the peripheral units 70, 71, 72 via the data and address bus lines 96 and 98. Control of peripheral units 70, 71, 72 and of their data/flow is effected by the appropriate circuits of the microprocessor 56. These circuits form a parallel interface which handles two 8-bit ports and has four modes of operation:
1. byte output (Port A, Port B)
2. byte input (Port A, Port B)
3. byte bidirectional (Port A)
4. bit mode of operation (Port A, Port B)
This unit occupies two addresses in each port within the system (data, command). Another circuit in the peripheral unit 70 serves for adapting the keyboard 36, to the system. The keys are arranged as matrix and are connected to the processor via a multiplexer, e.g. of 74 LS 251 type.
Communication between the display and the microprocessor 56 is realised by the peripheral unit 71. The peripheral unit 72 ensures the possibility of displaying the data on the printer 22. Priority of peripheral units: 1. Display 2. Printer 3. Keyboard
Selection of peripheral units is performed by the multiplexer encoding circuit, aided by address signals BA3 to BA6. The priority is ensured by the gate 74.
Operation of the apparatus starts with switching on which puts the circuits under voltage. In the active state the program burnt into the EPROM element 80 is ready for receiving the instructions coming from the keyboard 36.
By pushing the key RES the device is brought to its basic or starting position, the registers are erased and get ready for receiving data. As part of the switching-on procedure, the device tests itself. In this test the errorless operation of the RAM element 78 is checked and all cells are cleared. If the starting cycle shows no error a signal diode with allow the data input. If the starting cycle could not be completed successfully, then the ERROR sign will be on.
Pushing the key IN permits the input of basic data. This key starts the subroutine of the program which handles the input, and it waits for the data coming from the keyboard 36. As a result of pushing IN the starting address of the program is transferred into the PC-register. The data input of the microprocessor 56 receives an appropriate instruction. By pushing any of the numerical keys the binary value of the key enters the A-register from where the program allocates it into the appropriate RAM cell of the RAM element 78. This operation continues until all parameters enter. The program ensures that the data entry is errorless.
After entering the basic data the running of the program can be started.
Pushing the TN key gets the subroutine of calculating the tendency function (FIG. 18) start. The cycle consists of several sub-programs.
Totals are calculated first. For performing the work of addition the microprocessor 56 assignes control on the address lines the arithmetical processor 62. Over the data lines it transmits the code 9.0. H and the figures to be added. Intermediary results are forwarded to the register NOS of the arithmatical processor 62. Then intermediary results are sent back to the appropriate cell of the RAM element 78. This data flow is controlled by the microprocessor 56. With the computed data the operation of multiplication will be performed at first. Multiplication is controlled by the microprocessor 56 and is performed by the arithmetic microprocessor 62. In this case the data bus 96 receives the instruction. The numbers to be multiplicated are displaced in the registers TOS and NOS of the arithmatical processor 62. The results are put into the NOS-register. Power operations are controlled, the operand comes into the B-register, the power number into the A-register. The result appears in the NOS register.
In subsequent steps perform the subtractions and the multiplications are peformed on the basis of the intermediary results obtained. The square root of the fractional number's nominator and some other values should be determined also. This cycle has to be continued for the parameters of all machines to be proved. The SORT subroutine helps in finding the proper ranking. SORT findes--from the contents of the RAM element 78--with help of the SUB comparison instruction and of the subsequent JP jumping instruction the required ranking order.
NAT: Pushing this key ensures the calculation of the two variable function (so called natural surface) representing the present leading standards in technology. The input parameters are located in the RAM element 78 as storage. The "G" functions are performed with the help of routines built into the program. The results have the form of vectors. The algorithms for finding the F and G functions are shown in FIGS. 21 and 22. A machine-coded variant of the completed program can be seen in the appendix. Pushing this key results in the complete running of the program. Interruption can be made only with keys PAS and RES. In case of error, the running of the program is also interrupted and the error displayed. Flow chart of the program's running is shown in FIG. 23. A machine-coded realization of the program forms also part of the appendix. The running of the program is controlled by the microprocessor 56, supported by the arithmetical microprocessor 62, type Am 9511A. For storing intermediate results the following registers of the microprocessor 56 are usable: A, B, C, D, E, and C', D', E', H', L', and the following registers of the arithmetic microprocessor 62: A, B, C, D, and R. The result can be displayed on the screen, if the key DY or on the printer the key PR was pushed previously. The operation of computation can be performed so many times as required when any or all of the parameters are changed. In such cases the storage units assigned are rewritten.
A source language program for the microprocessors is presented in an appendix hereof.
By this procedure the design objectives for machines to be developed in the future can be determined or it is possible to find use-value of an existing machine as compared to the actual leading standards of technology.
It is to be understood that the above described embodiment of the invention is illustrative and that modifications thereof may occur to those skilled in the art. Accordingly, the invention is not to be regarded as limited to the embodiments disclosed herein, but is to be limited only as defined by the appended claims. ##SPC1## | Apparatus for the prediction of performance parameters of a proposed machine, in particular, an agricultural machine, includes a keyboard for entry of data in accordance with a set of input parameters useful in the calculation of performance parameters, a display for displaying performance parameters, a memory for storage of data inputted by the keyboard, and a data processor interconnecting the memory and the numerical board for performing mathematical calculations to output values of the performance parameters in response to the inputting of data at the keyboard. Included within the data processor is an analyzer for selecting input parameters specific to a mathematical correlation, a microprocessor for calculating values of intermediary parameters from the inputted data based on patterns of such data, and a synthesizer employing values of selected input parameters and the intermediary parameters to provide mathematical correlation for attaining values of the performance parameters. | 8 |
This is a Continuation of U.S. application Ser. No. 08/598,528, filed Feb. 8, 1996 U.S. Pat. No. 5,846,359.
FIELD OF THE INVENTION
The present invention relates to a method for fixing a reagent layer to a supporting base in the preparation of a dry analysis kit for determining a specific component in a liquid specimen. Such a kit is usually used in the field of clinical examinations, such as an urine analysis, a serum analysis, a whole blood analysis, and an immunoassay.
The present invention relates also to a method for preparing a peel type test piece, which is a dry analysis kit for determining a specific component in whole blood, usually used in a whole blood analysis in the field of clinical examination.
BACKGROUND OF THE INVENTION
In the field of clinical examination, analyses of various components in body fluids, such as blood, urine, saliva, cerebrospinal fluid, etc., offer guides to diagnosis of many diseases or objective judgement of the efficacy of a treatment.
A general method of these analyses is one called wet chemistry, in which a body fluid (specimen) and a reagent solution are put in a cuvette and stirred, the cuvette is incubated at 37° C. for a given period of time, and a substance produced by the reaction of a specific component of the specimen is determined with an absorption photometer, a fluorophotometer, a turbidimeter, etc.
On the other hand, an analytical method called dry chemistry is being developed. This method is advantageous in that a reagent is supplied as a dry state, preparation of a reagent on analyses is not at all necessary, stirring is not necessary, no waste liquid occurs, and a very small amount of a specimen would be enough for analyses of many items. Dry chemistry has been made use of for instantaneous examinations in emergency laboratories of hospitals, nurses'offices in hospitals at night, or doctor's offices.
The dry analysis kit used in dry chemistry generally comprises a reagent layer and a supporting base plate. The reagent layer is prepared by infiltrating a reagent capable of reacting with a component in a specimen into a porous matrix such as paper, cloth, nonwoven cloth, meshes, membrane filters, sinters, and ceramics, followed by drying, or by applying a mixture of the reagent and a polymer binder kneaded with a solvent to a thin resin film, followed by drying. While the reagent layer cut into strips can be used as such, where an expensive reagent, such as an enzyme, a substrate, or a color former, is used, use of the strip as having a large effective area would be uneconomical, leading to a great increase in cost.
Accordingly, a reagent layer is cut into 4 to 10 mm squares or rectangles, taking into consideration the size allowing visual colorimetry, the diameter of a light beam used in reflective photometry, accuracy of measurement, and ease in handling in the preparation or on use. The cut reagent layer is fixed onto a base serving as base or grip with an adhesive, e.g., a double-sided adhesive tape, a paste adhesive or an instantaneous adhesive or a hot melt resin.
Moreover, of the dry analysis kits for dry chemistry, a so-called peel type test piece comprising a base having thereon a reagent layer and a releasable film layer having a sample measuring function in this order is used in some cases. Upon use, after a specimen is applied to the peel type test piece, the film layer is stripped off to observe the coloration of the reagent layer.
More specifically, a film layer capable of filtering out corpuscles of whole blood and measuring out an adequate amount of a specimen to the reagent layer is laminated on a reagent layer prepared by impregnating a matrix made of a thermoplastic resin or a non-thermoplastic substance with a reagent. When the dry analysis kit of this type is used, a specimen (whole blood) is applied on the film layer, the corpuscles and excess blood are wiped off the surface of the film layer, and the film layer is stripped to expose the reagent layer to observe the degree of coloration of the reagent layer. In some cases, the film layer is stripped without being wiped.
As stated above, the most commonly employed method for fixing a reagent layer directly to a base is fixation with a double-sided adhesive tape. However, double-sided adhesive tapes usually use polyacrylic resins, which contain no small amounts of polymerization initiators, monomers, stabilizers, plasticizers and wetting agents. On contact with the reagent layer, these components tend to react with the reagent in the reagent layer resulting in coloration or decomposition of the active ingredient. Therefore, strict selection of a double-sided adhesive tape has been required for each item.
Further, fixation with a double-sided adhesive tape has been accompanied with such disadvantages that the adhesive adheres to a processing machine to cause machine trouble and that the adhesive adheres to the surface of a reagent layer to make a part of the reagent layer unreactive with a specimen, resulting in unevenness of color formation.
In order to eliminate these problems associated with a double-sided adhesive tape, fixation with a hot-melt adhesive (an adhesive consisting of a thermoplastic resin which softens at 80 to 150° C.) has been used. In this case, however, the whole reagent layer must be kept at 100 to 110° C. for several seconds to melt the hot-melt adhesive, which entertains a fear of denaturation of the reagent, particularly proteins, such as an enzyme, an antibody and an antigen. Additionally, the hot-melt adhesives contain plasticizers, stabilizers, and the like similarly to the double-sided adhesive tapes, and these components have adverse influences on the reagent.
A method comprising enveloping a reagent layer in fabric or a web and fusion bonding both sides of the envelope with a hot-melt adhesive has been suggested as a solution to the outstanding problems, as disclosed in JP-B-53-6551 (the term "JP-B" as used herein means an "examined published Japanese patent application"). The method consisting of enveloping a reagent layer in a nylon mesh and bonding both sides thereof with a hot-melt adhesive succeeds in solving the above-described two problems. However, there is a fear of the nylon mesh's getting loose due to shocks during transportation and, as a result, the reagent layer tends to move or come off. In addition, the method is troublesome and costly.
JP-B-6-68488 discloses a method for preparing a composition for detection, which comprises interposing a thermoplastic resin layer between a reagent layer and a base and cutting the laminate by means of a laser beam or ultrasonic waves to fix the cut area through fusion. This technique is for preparing a multi-layer kit for dry analysis without using an adhesive. However, the kit prepared is of the type that it is held by a clamping rod serving as a grip or placed on a holder on use. Further, margins cut off by a laser beam or ultrasonic waves go to waste. Moreover, a machine generating a laser beam or ultrasonic waves of sufficient power for cutting the laminate is required, and such a machine is generally expensive.
In particular, where a reagent layer to be fixed on a base is glass fiber filter paper, etc. having chemically bonded thereto an antibody, an antigen, an antibody-avidin-biotin complex, etc., which is used for microanalysis utilizing immune reaction (so-called dry immunoassay), use of a double-sided adhesive tape or a hot-melt adhesive gives rise to not only the above-mentioned problems but another problem that an unreacted component or a substance having an influence on the reaction is non-specifically adsorbed on the glass fiber filter paper to cause a great error.
Further, since the peel type test piece comprises at least three layers, the preparation process is troublesome because of involvement of two steps; one for adhering the first layer to the second layer, and then one for adhering the third layer to the second layer.
Furthermore, on removal of the film layer, it is necessary to be peeled between the film layer and the reagent layer. It is inconvenienced that the test pieces suffered peeling at the interface between the base and the reagent layer. Taking into consideration on this point, the adhesive strength between the reagent layer and the base should be stronger than the adhesive strength (hereinafter referred to as "interlaminar strength") between the reagent layer and the film layer. To make a difference in interlaminar strenth between the two adhesive interfaces is troublesome.
The three layers laid one on the other can be adhered at a time while making a difference in interlaminar strength between the two adhesive interfaces by use of two kinds of adhesives. However, components used in adhesives tend to give adverse influences to the reagent in the reagent layer as mentioned above. Therefore, use of adhesives is not favorable.
Hence it has been demanded to develop an ideal method for preparing a peel type test piece, by which the three layers can be fixed at a time without using an adhesive while making a difference in interlaminar bond strength.
SUMMARY OF THE INVENTION
It has been found that the above problems in the preparation of a dry analysis kit are solved by using a thermoplastic resin as material of either one or both of a reagent layer and a supporting base plate and externally applying ultrasonic vibration and pressure to a combination of the reagent layer and the supporting base plate to generate frictional heat.
An ultrasonic fusion technique used in the present invention has the following advantages.
Differing from adhesion via an adhesive, a thermoplastic resin constituting a layer(s) is fused and fixed by frictional heat generated by ultrasonic waves. Therefore, the reagent in a reagent layer undergoes no influence of plasticizers or solvents present in adhesives. Since the heat is generated instantaneously on the surface of the layer and abated rapidly, the reagent in the reagent layer does not undergo denaturation.
The method is economical; for the reagent layer and the base are directly fixed together so that there is no margin to be cut off. Since the ultrasonic vibration used in the present invention is directly transmitted to the reagent layer, a relatively cheap ultrasonic oscillator will do.
Where a laminate composed of a plurality of thermoplastic resin layers or a combination of a thermoplastic resin layer and a non-thermoplastic porous layer is subjected to ultrasonication from one side thereof to cause ultrasonic fusion, the inventors of the present invention have found that, on comparing the interlaminar bond strength among interfaces, the interlaminar strength becomes higher as the interface gets closer to the side to which ultrasonic waves have been applied. The present invention has been completed by applying this principle to the preparation of a peel type test piece.
When three layers are fusion bonded at a time by means of an apparatus for generating heat and transmitting the heat directly to the layers, although the interface closer to the side to which heat is applied can be fixed, it is difficult to fix the interface farther from the side for the matter of heat conduction. Even if the farther interface may be fixed, the closer interface will have been destroyed by great heat by that time, and the reagent will have lost its activity completely.
According to the method of the present invention, to the contrary, heat is conducted to the layers not directly but indirectly. That is, ultrasonic vibration is transmitted to the layers to induce frictional heat. Thus, the above-described problems never arise.
The present-invention thus provides quite a new method for preparing a dry analysis kit and a peel type test piece, which method is free from the disadvantages associated with conventional techniques while making effective use of all the advantages of ultrasonic fusion.
The object of the present invention is a method for fixing a reagent layer directly onto a supporting base plate in the preparation of a dry analysis kit for determining a specific component in a liquid specimen wherein at least one of the reagent layer and the base plate is a thermoplastic resin, and which comprises the steps of:
placing the reagent layer in contact with the base plate and externally applying ultrasonic vibration and pressure to the two layers to generate frictional heat thereby to melt the surface of the thermoplastic resin;
applying pressure to make the molten surface of thermoplastic resin bite the non-thermoplastic material or to integrate the surfaces of thermoplastic layer and base plate; and
removing the ultrasonic vibration and pressure.
The fixation method according to the present invention can take various embodiments. Illustrative embodiments are shown below with reference numbers according to the accompanying drawings.
Embodiment 1
A method for fixing a reagent layer directly onto a supporting base plate in the preparation of a dry analysis kit for determining a specific component in a liquid specimen, which comprises the steps of:
placing the reagent layer (1) in contact with the base plate (2) and externally applying ultrasonic vibration and pressure to generate frictional heat thereby to melt either the surface of the base (2) in contact with the reagent layer (1) or the surface of the reagent layer (1) in contact with the base (2);
applying pressure to make the molten surface material of one of the layers bite the other layer; and
removing the ultrasonic vibration and pressure.
In this embodiment, either one of supporting base (2) and reagent layer (1) is made of a thermoplastic resin, while the other is a porous matrix made of non-thermoplastic material. In other words, embodiment (1) includes two types; in one type base (2) is a thermoplastic resin plate while reagent layer (1) is a porous matrix made of nonthermoplastic material coated or impregnated with a reagent; and in the other type base (2) is a plate formed of a porous matrix made of non-thermoplastic material while reagent layer (1) is a thermoplastic resin film coated with a reagent.
In another embodiment, both a supporting base plate and a reagent layer may be made of thermoplastic resins as described below with reference numbers of the accompanying drawings.
Embodiment 2
A method for fixing a reagent layer directly onto a supporting base in the preparation of a dry analysis kit for determining a specific component in a liquid specimen, which comprises the steps of:
placing the reagent layer (4) in contact with the base (5) and externally applying ultrasonic vibration and pressure to generate frictional heat thereby to melt both the surface of the base (5) in contact with the reagent layer (4) and the surface of the reagent layer (4) in contact with the base (5);
applying pressure to integrate the molten surface of the base (5) and the molten surface of the reagent layer (4); and
removing the ultrasonic vibration and pressure.
In this embodiment, both base (5) serving as a supporting base plate and reagent layer (4) are made of thermoplastic resins. Reagent layer (4) may take two forms; a porous matrix impregnated or coated with a reagent, and a thin resin film coated with a reagent. The integrated part of base (5) and reagent layer (4) is indicated by reference number (6) in FIG. 3.
One embodiment of the present invention is utilizing torsional ultrasonic waves.
Embodiment 3
A method for fixing a reagent layer comprising a very thin thermoplastic resin film coated with a reagent directly onto a supporting base in the preparation of a dry analysis kit for determining a specific component in a liquid specimen, which comprises the steps of:
placing the reagent layer in contact with the base and applying torsional ultrasonic vibration and external pressure to melt the surface of the reagent layer in contact with the base;
applying pressure to make the molten surface of the reagent layer bite the surface of the base or to integrate the molten surface of the reagent layer and the surface of the base;
removing the torsional ultrasonic vibration and pressure.
The terminology "torsional ultrasonic waves" as used herein denotes a concept characterized the most by having transverse vibration. The concept represented by this terminology makes contrast to that of the generally used terminology "ultrasonic waves" which means vertical vibration.
The conception of "torsional ultrasonic waves" would be understood easily by visualizing the scene of a glass's (having a circular mouth) being pressed to a plane with its mouth down while being rotated at a fixed position. The brim of the glass corresponds to a horn of an ultrasonic oscillator, and the torsional movement corresponds to transverse vibration.
Ordinary vertical ultrasonic vibration cannot melt a very thin thermoplastic resin film. On the other hand, torsional ultrasonic waves, which produce transverse vibration, can transmit vibration energy to the surface of a very thin film to melt the film due to its excellent energy efficiency. Since a transverse vibration has "scrub movement" also, it can completely fuse bond a very thin film to a base to provide a dry analysis kit having the film as a reagent layer. By the "scrub movement", the torsional ultrasonic wave can completely fuse bond a very thin film to a base even at small energy and low heat.
Embodiment 4
A method for preparing a peel type test piece for dry analysis for determining a specific component in a liquid specimen comprising a supporting base plate having thereon a reagent layer comprising a porous matrix impregnated with a reagent and further having thereon a releasable film layer having a function of filtering out corpuscles, the releasable film layer being to be stripped after application of a specimen to observe coloration of the reagent layer, which comprises the steps of:
superposing the reagent layer and the film layer on the supporting base plate in this order in mutual contact and applying ultrasonic vibration from the supporting base plate side;
applying pressure to make the surface of a molten layer bite the surface of an adjacent non molten layer or to integrate the surface material of a molten layer with the surface of an adjacent layer; and
removing the ultrasonic vibration and pressure.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a dry analysis kit according to the present invention, which is common to Embodiments 1, 2 and 3, at the time when fixation of a reagent layer and a supporting base plate is completed.
FIG. 2 is a cross section of a dry analysis kit according to Embodiment 1 of the present invention, showing the fixing condition.
FIG. 3 is a cross section of a dry analysis kit according to Embodiment 2 of the present invention, showing the fixing condition.
FIG. 4 is a plane view of the dry analysis kit of Example 1 of the present invention at the time when fixation is completed.
FIG. 5 is a cross section of the dry analysis kit of Example 1 of the present invention at the time when fixation is completed.
FIG. 6 is a plane view of a dry analysis kit of the present invention after completion of fixation and cutting into a strip.
FIG. 7 is a plane view of a dry analysis kit in which a reagent layer is fixed by fusion at areas except the central portion.
In FIGS. 1 to 7,
(1) . . . Reagent layer of Embodiment 1 (porous matrix coated or impregnated with a reagent) or Embodiment 3 (very thin layer coated with a reagent)
(2) . . . Base (thermoplastic resin plate or a porous matrix made of non-thermoplastic material)
(3) . . . Molten part of the base (resin)
(4) . . . Reagent layer of Embodiment 2 (thermoplastic resin film coated with a reagent)
(5) . . . Base (thermoplastic resin plate)
(6) . . . The molten parts of (4) and (5)
(7) . . . Fusion bonded part (streaks)
(8) . . . Fusion bonded part (spots avoiding the central portion of a reagent layer).
FIGS. 8A-8B provide a plane view (FIG. 8A) and a side view (FIG. 8B) of a dry analysis kit of Embodiment 3 according to the present invention in a state before cutting.
FIG. 9 is a plane view of a dry analysis kit according to Embodiment 3 according to the present invention in a state after cutting.
FIG. 10 is an enlarged plane view of the tip of the dry analysis kit shown in FIG. 9.
In FIGS. 8 to 10,
(9) . . . Supporting base plate (base)
(10) . . . Reagent layer (very thin thermoplastic resin film)
(11) . . . Fusion bonded part.
FIGS. 11A-11B show a plane view (FIG. 11A) and a cross sectional view (FIG. 11B) of a dry analysis kit of Embodiment 4 according to the present invention in a condition before cutting.
FIG. 12 is a plane view of the dry analysis kit of FIGS. 11A-B after cutting to 7 mm widths (the cross section is the same as FIG. 11B).
In FIGS. 11A-B and 12,
(12) . . . Supporting base plate (base)
(13) . . . Reagent layer (porous matrix)
(14) . . . Film layer
(15) . . . Ultrasonic fusion bonded part (streak).
To be easy to understand the structures of the present invention, the proportions of widths and thicknesses are appropriately modified in these figures.
DETAILED DESCRIPTION OF THE INVENTION
Whether made of a thermoplastic resin or a non-thermoplastic material, the base should have such a thickness that ensures sufficient strength for supporting a reagent layer to be fixed thereon. Such a thickness is decided in the same manner as with usual dry analysis kits. The base thickness is usually 0.1 to 0.4 mm.
The non-thermoplastic material include three-dimension lattice structural materials such as paper (filter), wood, nonwoven fabric such as a membrane filter, woven fabric, knit fabric, glass such as glass fiber filter, a sinter, ceramics such as porous ceramic sheet, metal cloth and polymer microbeads. It is preferable that these are porous matrix. It is essential that the material should not be fused by heat.
The thermoplastic resins which can be used in the supporting base plate or reagent layer can be selected from those generally employed in dry analysis kits of this kind. Preferable examples are polyethylene terephthalate (sometimes abbreviated as PET), polycarbonate, polypropylene, polyethylene, polystyrene, polyvinyl acetate, polyvinyl chloride and a cellulose ester. Examples of these forms are a uniaxially stretched porous film, a biaxially stretched porous film and an irradiated porous film.
Impregnation or coating of a porous matrix with a reagent and coating of a thermoplastic resin film with a reagent can be carried out in a conventionally employed method for the preparation of dry analysis kits. That is, a reagent of a given amount necessary for analysis is dissolved or dispersed in a solvent, and the solution or dispersion is infiltrated into a porous matrix by means of an impregnating apparatus, etc., or a reagent is kneaded with a solvent and a polymer binder, and the mixture is applied to a film by means of a coating apparatus and dried in a drier.
A reagent layer and a supporting base plate are superposed, and ultrasonic vibration and a pressure are applied for several 10 -1 seconds. The ultrasonic vibration having a frequency of 20 kHz and a pressure of 60 to 80 kg/cm 2 are preferable. The ultrasonic vibration was stopped, and the pressure application is continued for an additional period of several 10 -1 seconds and then the pressure is removed. The reagent layer and the supporting base plate can thus be fixed together.
In the case where all the contact area between a reagent layer and a supporting base plate is subjected to ultrasonic fusion, some influence of heat of fusion, though slight, may be exerted on the reagent. Although the influence is so slight as to need no countermeasure for avoidance, it is preferable that the reagent layer and the base are fusion bonded not over the entire surface of the reagent layer but at a plurality of spots. It can be avoided by, for example, applying ultrasonication only to the peripheral portion of the reagent layer in streaks or spots while avoiding the central portion. An example of such spot fusion is shown in FIG. 7. An example of such streaks fusion is shown in FIGS. 4 and 5.
The dry analysis kit according to Embodiment 1 can be prepared by, for example, impregnating filter paper with a reagent capable of color formation upon specific reaction with a substance under analysis in a liquid specimen, drying the impregnated filter paper to obtain a reagent layer, putting the reagent layer on a polyethylene terephthalate plate as a supporting base plate, and imposing pressure while applying ultrasonic waves, whereby the molten polyethylene terephthalate of the supporting base plate side bites the reagent layer to achieve complete fixation through what we call an anchoring effect.
In another type of the dry analysis kit of Embodiment 1, the reagent layer is prepared by, for example, coating a thin polyethylene terephthalate film with a kneaded mixture of a reagent capable of color formation upon specific reaction with a substance under analysis contained in a liquid specimen and a polymer binder, followed by drying. The reagent layer is put on a base made of a non-thermoplastic porous matrix, such as filter paper, and subjected to ultrasonication. It is the surface of the reagent layer thin film in contact with the base that is melted by ultrasonication. The molten polyethylene terephthalate bites the supporting base plate to achieve complete fixation through a so-called anchoring effect.
The thin polyethylene terephthalate film used for providing a reagent layer can have a thickness of 50 to 150 μm, which is usually used in the art.
When the dry analysis kit of the latter of Embodiment 1 is used in a dip system, an additional advantage will be offered. That is, when the dry analysis kit is dipped in a liquid specimen and taken out, excess of the liquid specimen is absorbed by the supporting base plate and prevented from migrating to the reagent layer.
The dry analysis kit according to Embodiment 2 can be prepared by, for example, coating a thin polyethylene terephthalate film with a kneaded mixture of a reagent capable of color formation upon specific reaction with a substance under analysis contained in a liquid specimen and a polymer binder, followed by drying to prepare a reagent layer, putting the reagent layer on a polyethylene terephthalate plate, and imposing pressure while applying ultrasonic waves. The molten polyethylene terephthalate of the reagent layer side and that of the base side are brought into contact and thus integrated. On temperature drop, the both are completely fixed together.
In Embodiment 3, in using a supporting base plate made of a thermoplastic resin, the molten resin of a reagent layer is integrated with a similarly ultrasonication-molten resin of the supporting base plate and thus fixed thereto. In using a supporting base plate made of a porous matrix made of non-thermoplastic material, the molten resin of a reagent layer bites into the pores of a supporting base plate to achieve fixation through a so-called anchoring effect.
A thin reagent layer and a supporting base plate are superposed, and torsional ultrasonic vibration and a pressure are applied for several 10 -1 seconds. The torsional ultrasonic vibration having a frequency of 40 kHz and a pressure of 60 to 80 kg/cm 2 are preferable. The ultrasonic vibration was then stopped, and the pressure application is continued for an additional period of several 10 -1 seconds and then the pressure is removed. The reagent layer and the supporting base plate can thus be fixed together.
Further, in Embodiment 3, it is preferable that the thin thermoplastic resin film has a thickness of 10 to 50 μm.
Embodiment 4 of the present invention is a method for preparing a peel type test piece comprising a supporting base plate having thereon a reagent layer and further having thereon a releasable film layer having a sample measuring function. The material of each layer will be specified later.
In the Embodiment 4, where a thermoplastic resin layer and a porous matrix made of a non-thermoplastic material are adjacent to each other, it is an essential condition that the thermoplastic resin on the surface section of the former layer is melted by ultrasonic waves and the molten resin is made to bite the pores of the latter layer to achieve fixation by a so-called anchoring effect. Where two adjacent layers are both made of a thermoplastic resin and the surface resin of both the two layers is melted, it is an essential condition that the resins on the surface of the two layers are integrated into one body to achieve fixation.
Accordingly, of the three basic layers constituting a peel type test piece using a porous matrix as a reagent layer, it is essential that (1) all of them are made of thermoplastic resins, (2) two of them are made of thermoplastic resins, with the remaining one being a porous matrix made of non-thermoplastic material, or (3) the intermediate one of them is made of a thermoplastic resin, with the upper and lower layers being a porous matrix made of non-thermoplastic material. In other words, care should be taken so that a porous matrix made of non-thermoplastic material may not be adjacent to another porous matrix made of non-thermoplastic material.
In more detail, the peel type test piece of the present invention using a porous matrix as reagent layer embraces the following layer structures.
(1) All the supporting base plate, reagent layer and film layer are made of thermoplastic resins.
(2) The supporting base plate and film layer are made of thermoplastic resins, while the reagent layer is a porous matrix made of a non-thermoplastic material.
(3) The supporting base plate and film layer are a porous matrix made of non-thermoplastic material, while the reagent layer is a porous matrix made of a thermoplastic material.
(4) The supporting base plate and reagent layer are made of thermoplastic resins, while the film layer is a porous matrix made of a non-thermoplastic material.
The film layer is a matrix having a plurality of pores for securing an ability of filtering blood or an ability of retaining liquid. Alternatively, the film layer itself does not have pores but is equipped with a part having an ability of measuring out a specimen or retaining a specimen.
Examples of the method according to the present invention for preparing a dry analysis kit having a fixed reagent layer and peel type test piece will be illustrated by referring to the accompanying drawings. It should be understood that the present invention is not construed as being limited thereto.
EXAMPLE 1
A dry analysis kit for the detection of occult blood in urine was prepared as an example according to the following prescription.
Prescription
First impregnating solution:
______________________________________Potassium hydrogenphthalate buffer 150 ml(0.5M; pH 5.3)Ethanol 100 mlSodium lauryl sulfate 200 mgEthylenediaminetetraacetic Acid Disodium Salt 20 mgCumene hydroperoxide 20 ml______________________________________
Second impregnating solution:
______________________________________Ethanol 80 mlXylene 120 ml7-Methylquinoline 1 ml3,3',5,5'-Tetramethylbenzidine 1 g______________________________________
Porous matrix: 2Chr Filter Paper produced by Whatman
Base: 0.3 mm thick PET film
The porous matrix was dipped in the first impregnating solution prepared according to the above formulation and dried, and subsequently dipped in the second impregnating solution and dried to obtain a reagent layer. The resulting reagent layer was placed on the base, and ultrasonic vibration at a frequency of 20 kHz and a pressure of 70 kg/cm 2 were applied thereto for 0.2 second. The ultrasonication was stopped, and pressure application was continued for an additional period of 0.2 second and removed.
In this example, the ultrasonic vibration was applied in streaks. The fusion condition is shown in FIGS. 4 and 5. The porous matrix having the reagent thus fixed thereto was slit to prescribed widths of 5 mm to obtain dry analysis kits as shown in FIG. 6.
Comparative Example 1
For comparison, a reagent layer prepared according to the same formulation as in Example 1 was adhered to the base via a double-sided adhesive tape and cut to a prescribed size to obtain dry analysis kits.
Each of the dry analysis kits prepared above was put in a glass bottle and sealed together with a desiccant. The glass bottle was preserved at 50° C. for a prescribed period of time to conduct an accelerated test. As specimens, two beforehand prepared control urine preparations having different hemoglobin levels (0 mg/dl, designated preparation 1; and 0.2 mg/dl, designated preparation 2) were analyzed by means of an exclusive reflective photometer (spectral differential calorimeter SZ-Σ80, manufactured by Nippon Denshoku Kogyo K.K.). The results obtained are shown in Table 1 below.
TABLE 1______________________________________Reflectance (R %) Hemoglobin Level (Preparation 1) (Preparation 2) 0 mg/dl 0.2 mg/dlDays of 0 0Preservation (initial) 7 14 (initial) 7 14______________________________________Ultrasonic 97.4 96.0 94.5 19.0 20.8 22.2FusionDouble-sided 97.8 89.2 81.8 18.8 35.7 48.2Adhesive Tape______________________________________
It is seen from Table 1 that the reflectance in the analysis of preparation 1 reduces with time. The reduction in reflectance means coloration of the reagent layer, indicating poor stability of the reagent layer. The increase in reflectance as observed with preparation 2 means reduction in sensitivity of the reagent layer, also indicating poor stability of the reagent layer. The results in Table 1 prove that the dry analysis kits prepared by the ultrasonic fusion fixation technique according to the present invention show a significant improvement in stability.
The reduction in stability is caused by the influences of components contained in the double-sided adhesive tape which make the analytical composition instable, such as an organic solvent and a plasticizer. To the contrary, the reagent layer fixed by ultrasonic fusion is not influenced by such components nor by the heat of fusion.
Comparative Example 2
In order to examine the degree of influence by the heat of fixation, a reagent layer prepared and cut into strips in the same manner as in Example 1 but not fixed on a supporting base plate was prepared as a dry analysis kit and compared with the dry analysis kit of the present invention in the case where all the contact area between a reagent layer and a base plate. A beforehand prepared control urine preparation having a hemoglobin level of 0.2 mg/dl was analyzed as a specimen by means of an exclusive reflective photometer. Measurement was made 5 times for each dry analysis kit, and the results obtained are shown in Table 2 below.
TABLE 2______________________________________Reflectance (R %) 1 2 3 4 5 Average______________________________________Ultrasonic fused 19.5 20.2 18.5 17.3 19.5 19.0dry analysis kitDry analysis kit 18.3 16.8 19.2 18.9 19.3 18.5with no supportingbase plate______________________________________
It is seen from Table 2 that the dry analysis kit prepared by ultrasonic fusion in the case where all the contact area between a reagent layer and a base plate gives substantially the equal results to those of the dry analysis kit with no supporting base plate, proving that the ultrasonic fusion according to the present invention gives very little of influence of heat to the reagent.
EXAMPLE 2
A dry analysis kit for the detection of nitrites in urine was prepared as an example according to the following prescription.
Prescription
______________________________________d-Naphthylamine 1.0 gSulfanilamide 2.5 gTrichloroacetic acid 3.0 gPolyvinyl butylacetal 20.0 gMethanol 100 ml______________________________________
Thermoplastic resin plate (used as supporting base plate (9)) . . . 0.3 mm thick PET film)
Thermoplastic resin film (used as reagent layer (10)) . . . 1 cm wide and 20 μm thick PET film tape)
Ultrasonic oscillator . . . 900 Series, Model 947M, manufactured by Emerson Japan Ltd.
A coating composition was prepared according to the above formulation and applied to the film with a coating machine to a thickness of 400 μm and dried in hot air to prepare a reagent layer (reagent layer (10)).
Reagent layer (10) was placed on base (9), and torsional ultrasonic vibration at a frequency of 40 kHz and a pressure of 70 kg/cm 2 were applied thereto for 0.2 second. The vibration was ceased, and pressure application was continued for an additional period of 0.2 second and then released.
The ultrasonic oscillation horn used had a cylindrical shape having an outer diameter of 6 mm and an inner diameter of 4 mm. As indicated by reference number (11) in FIGS. 8 to 10, the reagent layer was fixed by fusion in a circle in the peripheral portion thereof so as to avoid the central portion. The circle had an outer diameter of 6 mm and an inner diameter of 4 mm.
The thus prepared dry analysis kit shown FIG. 8 was cut into 1 cm wide strips to obtain dry analysis kits shown in FIG. 9.
On being dipped in nitrite-containing urine, the dry analysis kit satisfactorily assumed a red color in accordance with the nitrite content.
In the case of using a very thin film as in the above Example as a reagent layer, ordinary ultrasonication does not cause fusion whereas torsional ultrasonic waves can cause fusion as described above to prepare a dry analysis kit without involving activity reduction.
EXAMPLE 3
A peel type test piece was prepared as an example according to the following technique.
Base (supporting base plate): 0.3 mm thick white polyethylene terephthalate film, produced by Teijin Ltd. (shown by reference number (12) in FIG. 11B)
Porous matrix (reagent layer): 0.3 mm thick filter paper, 3MMChr produced by Whatman (shown by reference number (13) in FIG. 11B)
Film layer: 0.3 mm thick nylon mesh, produced by Teijin Ltd. (shown by reference number (14) in FIG. 11B)
A 7 mm wide reagent layer tape and a 10 mm wide film layer tape were placed on a 70 mm×360 mm base in the order described as shown in FIG. 11A. Ultrasonic vibration having a frequency of 20 kHz and a pressure of 70 kg/cm 2 were imposed to the base side for 0.2 second. After stopping application of ultrasonic vibration, pressure application was further continued for an additional period of 0.2 second and then released. The ultrasonic and pressure application was made in a streak form. The fixed part is shown by reference number (15) in FIG. 11A. Thereafter, the fixed layers were cut to 7 mm widths to obtain peel type test pieces shown in FIG. 12.
Test
Twenty test pieces were prepared. The film layer of each test piece was spotted with 10 μl of blue ink (aqueous ink for fountain pen) and wiped immediately after spotting. Sixty seconds later, the sample measuring layer (film layer) was peeled off.
Results
All the reagent layers of the twenty test pieces were found colored in blue. On removal of the film layer, none of the test pieces suffered peeling at the interface between the supporting base plate and the reagent layer instead of the interface between the film layer and the reagent layer.
Since the method of the present invention uses no adhesive (a double-sided adhesive tape, a hot-melt adhesive, etc.), no chemical influence is exerted on a reagent, and improvement in performance can be expected. Neither does the reagent undergo physical damage due to adhesion of a paste adhesive, etc. To use no adhesive results in cost reduction. From the standpoint of productive equipment, because a cheap ultrasonic oscillator may be used, the machinery can be made simpler and less expensive, and the steps involved are simplified, thus realizing reduction of production cost.
Further, even when such a very thin film that usual vibration energy cannot be concentrated is used as a reagent layer, the method of the present invention achieves ultrasonic fusion securely.
Moreover, as has been described in detail, the present invention makes it possible to fix three layers at a time without the aid of an adhesive while giving a difference between interfaces in interlaminar strength to prepare a peel type test piece. That is, the present invention provides quite a new method for preparing a peel type test piece, which method is free from the disadvantages associated with conventional techniques while making effective use of all the advantages of ultrasonic fusion.
While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | A method for fixing a reagent layer directly onto a supporting base plate in the preparation of a dry analysis kit for determining a specific component in a liquid specimen wherein at least one of the reagent layer and the base plate is a thermoplastic resin, and which comprises the steps of:
placing the reagent layer in contact with the base plate and externally applying ultrasonic vibration and pressure to the two layers to generate frictional heat thereby to melt the surface of the thermoplastic resin;
applying pressure to make the molten surface of thermoplastic resin bite the non-thermoplastic material or to integrate the surfaces of thermoplastic layer and base plate; and
removing the ultrasonic vibration and pressure. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 11/079,822, filed Mar. 15, 2005, now U.S. Pat. No. 7,614,400, which is a continuation of application Ser. No. 10/685,001, filed Oct. 15, 2003, now U.S. Pat. No. 6,918,390, which is a continuation of application Ser. No. 09/935,778, filed Aug. 24, 2001, now U.S. Pat. No. 6,679,261, which claims the benefit of U.S. Provisional Application No. 60/227,472, filed Aug. 24, 2000, each incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an improved comfort device to be used with a nasal mask. In particular, the device is useful in combination with masks which are used for the treatment of respiratory conditions and assisted respiration. The invention assists in fitting the mask to the face as well.
2. General Background
Nasal masks are commonly used in the treatment of respiratory conditions and sleep disorders by delivering a flow of breathable gas to a patient to either assist the patient in respiration or to provide a therapeutic form of gas to the patient to treat sleep disorders such as obstructive sleep apnea. These nasal masks typically receive a gas through a supply line which delivers gas into a chamber formed by walls of the mask. The mask is generally a semi-rigid mask which has a face portion which covers at least the wearer's nostrils. Additionally, the mask may be a full face mask. The mask is normally secured to the wearer's head by straps. The straps are adjusted to pull the mask against the face with sufficient force to achieve a gas tight seal between the mask and the wearer's face. Gas is thus delivered to the mask and the wearer's nasal passages and/or mouth.
One of the problems that arises with the use of the mask is that in order for the straps to be tight, the mask is compressed against the wearer's face and may push unduly hard on the wearer's nose. Additionally, the mask may move around on the wearer's face. Thus, there has been provided a forehead support, which provides a support mechanism between the mask and the forehead. This forehead support prevents both the mask from pushing too strongly against the wearer's nose and/or facial region as well as minimize movement of the mask with the addition of a contact point between the mask and the wearer's head as well as minimize uncomfortable pressure points of the mask. Additionally, the forehead support may prevent the airflow tube from contacting the wearer's forehead or face.
FIG. 1 shows a general perspective view of a related art forehead support 10 . The forehead rest or support 10 is attached to an airflow tube 12 extending from the mask 14 . The mask 14 and forehead support 10 are shown with headgear 16 which secures the mask 14 to the head of a patient. As can be seen in FIG. 1 , the headgear 16 loops through the forehead support 10 at loops 18 and 20 . This pulls the forehead support 10 against the forehead, thus creating a snugly fitted mask 14 and also provides a stabilizing member for the mask 14 .
FIG. 2 discloses the construction of the related art forehead support 10 . The forehead support 10 has pads 24 and 26 , a back side of which can be seen in greater detail in FIG. 10 . These pads 24 and 26 are the actual contact points of the forehead support 10 to the forehead. The support pads 24 and 26 are mounted to the bridge 32 . Arms 34 and 36 are secured to bridge 32 by an adjustable locking mechanism which is better illustrated in the figures below. The bridge 32 provides three purposes to the forehead support 10 . First, it acts as a securing means for pads 24 and 26 . Second, it has loops 18 and 20 which receive the optional headgear 16 shown in FIG. 1 . Finally, it receives arms 34 and 36 , which may be adjusted, as described below. The bridge 32 and arms 34 and 36 operate in a cantilever fashion and are made of a polymeric material, which may be easily molded. Additionally, arms 34 and 36 join together to create an annular space 38 to receive airflow tube 12 which is connected to a flow generator to generate breathable air or some type of therapeutic gas. Arms 34 and 36 create an operational hinge. The tube 12 is an axis of this hinge.
FIG. 3 is an exploded view of FIG. 2 and shows the forehead support 10 in greater detail. Bridge engaging pins 56 , 58 , 60 and 62 are shown in FIG. 3 . As will be more apparent in the figures below, these engaging pins provide for the adjustability of the forehead support 10 . Bridge 32 includes slots 76 , 78 , 82 , 84 , 86 , 88 and 90 (see FIG. 9 ) and a mirror set of slots on the upper portion of bridge 32 (not visible in FIG. 9 ) for selectively receiving pins 56 , 58 , 60 and 62 . These slots open to the forehead side of the bridge. Additionally, there is a space or recess at arms 34 and 36 shown on arm 34 as 64 . The purpose of this space 64 is so that the user may compress arm 34 and thus press pins 56 and 58 together by pressing on surfaces 66 and 68 . The purpose of the compression is to decrease the distance between pins 56 and 58 such that they may be selectively inserted and locked into the desired pair of slots on bridge 32 . The length of the pins 56 and 58 is such that even when the pins are pressed together, they do not clear the slots in the bridge sufficiently to allow the arms to be disassembled from the bridge without further action.
FIG. 4 is a side view of the mask 14 and forehead support 10 . The mask is shown as 14 with a dotted line showing the nose of a wearer 70 and the dotted line showing the forehead 72 of the wearer. Pad 26 is shown compressed by the forehead of the individual wearing the mask.
FIG. 5 is a top view of the forehead support 10 taken along lines 5 of FIG. 4 . Also, the mask 14 is not shown in FIG. 5 . This figure illustrates the forehead support 10 in a position wherein the forehead support is in the closest position to the tube 12 (shown as merely a space in FIGS. 5-6 ). The bridge 32 is shown essentially in contact with tube 12 . The pins 56 , 58 , 60 and 62 are shown in their furthest position from the center of the bridge 32 , engaging slot pairs 88 and 90 . This position may be utilized by someone with a large, protruding or bulbous forehead, or a high nasal bridge, or someone who prefers the airflow tube to be snug against their forehead. FIG. 6 shows the same forehead support in the next position, wherein the bridge 32 is moved away from tube 12 such that there is a gap 74 between bridge 32 and tube 12 . Here, pins 56 , 58 , 60 and 62 engage slot pairs 76 and 86 . As is visible from the figure, the forehead support 10 is now moved away from tube 12 , and is positioned differently than in FIG. 5 . This may be configured to fit someone with a less protruding forehead, or someone who wants the flexible tube further from their head than is possible in FIG. 5 . FIGS. 7 and 8 show the third and fourth position for the forehead support.
The related art arm 34 is shown in greater detail in FIGS. 11-13 . As can be seen in the top view of the arm 34 shown in FIG. 11 , the arm 34 includes a semicircular portion 100 , on an interior of which the annular space 38 is situated. An extending portion 102 extends from the semicircular portion 100 . Surfaces 66 and 68 , space 64 and engaging pins 56 and 58 are positioned on the extending portion 102 . Each surface 66 and 68 includes a generally oval depression 106 and 108 , respectively, positioned near the pins 56 and 58 . These oval depressions 106 and 108 can be felt by the wearer of the mask and assist the wearer in properly positioning his or her fingers near the pins 56 and 58 when it is desired to adjust the forehead support. This is especially important when the mask and forehead support are positioned on the wearer's head because at such time, the wearer cannot easily see where to place his or her fingers to adjust the forehead support. The oval depressions not only assist the wearer in properly positioning his or her fingers for adjusting the support, by virtue of the fingers engaging the depressions, the depressions also help maintain the fingers in the appropriate position.
FIG. 12 is a side view of the arm shown in FIG. 11 . As can be seen there, the semicircular portion 100 only extends upward to half of the height of the arm 34 . Because of this, the arm 34 is reversible, i.e., it can be flipped over, and then can be used as arm 36 . Thus, only one arm design need be molded and this can be used as both arm 34 and arm 36 , depending on its orientation. Extending portion 102 includes two horizontal flanges 110 and 112 connected by an intermediate web 114 . The two horizontal flanges are thicker in the horizontal direction and thinner in the vertical direction than web 114 . The space 64 is positioned on web 114 . The force required to press the pins 56 and 58 together is a function of the amount of material of the extending portion 102 on either side of the space 64 in the vertical direction, the length space 64 extends along portion 102 (i.e., the length of each cantilever arm on either side of space 64 ) and the type of material from which the arm 34 is constructed. These arms have been constructed of a polycarbonate, specifically, Makrolon 2458 manufactured by Bayer.
FIG. 13 shows a cross-section of the arm 34 along line 13 - 13 in FIG. 12 . The comparative thicknesses of the flange 112 and the web 114 in the horizontal direction can best be seen here. The hatched portion of the arm 34 is the portion of the web 114 beyond the extended length of the space 64 .
It has been found that while the related art forehead support performs correctly if operated according to the instructions, an improvement can be made to reduce the risk of breakage when the forehead support is operated in a manner contrary to instructions.
Further, because depressions 106 and 108 are relatively narrow, an improvement can be made to allow the user to positively and firmly position his or her fingers to press the pins 56 and 58 together. Finally, because there is a relatively large amount of material contact between an interior of semicircular portion 100 and an exterior of airflow tube 12 , this can result in a relatively large amount of friction between the arm 34 and the tube 12 , thereby requiring additional force to pivot the arm 34 around the tube 12 for adjustment purposes.
SUMMARY OF THE INVENTION
The present invention is directed to an improved version of the type of forehead support discussed above. In particular, the present invention utilizes improved arms extending from the mask or gas supply line for adjustably engaging the bridge for allowing positioning of the mask on the face. First, extending portions of the arms are redesigned to compress more easily than the extending portions of the related art arms discussed above while at the same time maintaining the strength necessary for adequately supporting the airflow tube. Thus, the engaging pins may more easily be compressed together to allow for adjustment of the arms with respect to the bridge.
Furthermore, the extending portions of the arms are provided with locking portions that maintain alignment of the pins with respect to one another as they are being compressed to prevent lateral deflection of the pins, unintended stress loading on the arms and to allow easier engagement of the pins with the slots upon release of the extending portions.
Finally, arc portions of the arms that come into contact with the airflow tube 12 are undercut and radiused to prevent sticking or binding of the arms as they are pivoted about the airflow tube during adjustment of the forehead support, as compared to the related arm embodiment. Thus, the arms more easily pivot about the airflow rube during adjustment of the forehead support.
These improvements make it easier to adjust the forehead support, as well as make it easier to disassemble the arms from the bridge to allow thorough cleaning of the bridge and other support components.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a related art forehead support attached to a mask, headgear and a gas supply tube;
FIG. 2 is a perspective view of the forehead support of FIG. 1 removed from the mask and gas line;
FIG. 3 is an exploded view of the forehead support of FIG. 1 ;
FIG. 4 is a side view of the forehead support of FIG. 1 secured to a mask;
FIG. 5 is a top view of the forehead support of FIG. 1 in a first position;
FIG. 6 is a top view of the forehead support of FIG. 1 in a second position;
FIG. 7 is a top view of the forehead support of FIG. 1 in a third position;
FIG. 8 is a top view of the forehead support of FIG. 1 in a fourth position;
FIG. 9 is a front view of a bridge of the support of FIG. 1 ;
FIG. 10 is a single pad of the support of FIG. 1 ;
FIG. 11 is a top view of a of an arm for use in the forehead support of FIG. 2 ;
FIG. 12 is a side view of the arm of FIG. 11 ;
FIG. 13 is a section view of the arm of FIG. 12 along section line 13 - 13 ;
FIG. 14 is a top view of an improved arm for use in the forehead support of FIG. 2 ;
FIG. 15 is a side view of the arm of FIG. 14 ;
FIG. 16 is a section view of the arm of FIG. 15 along section line 16 - 16 ;
FIG. 17 is a perspective view of the arm of FIG. 11 ;
FIG. 18 is a partial section view of the arm of FIG. 13 along section line 18 - 18 ;
FIG. 19 is a partial section view of the arm of FIG. 15 along section line 19 - 19 ; and
FIG. 20 is a partial section view of the arm of FIG. 15 along section line 19 - 19 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 14 shows a top view of an improved embodiment of an arm for use with the present invention. Arm 200 includes a semicircular portion 202 and an extending portion 204 attached thereto. Semicircular portion 202 includes two arc portions 230 and 232 and an inner bore 234 . The two arc portions 230 and 232 are both recessed or undercut near their ends, as shown by the phantom lines 236 and 238 . Thus, the inner bore 234 is not perfectly circular in shape near the ends of arc portions 230 and 232 . Ends 240 and 242 of the arc portions 230 and 232 , respectively, are well radiused to prevent binding of the arm on the airflow tube during pivoting.
Extending portion 204 includes two flange portions 206 and 208 on which generally oval depressions 210 and 212 are respectively positioned. Bridge engagement pins 214 and 216 are positioned at far ends of flange portions 206 and 208 , respectively, and project, respectively, upwardly and downwardly from the arm 200 . A space 218 separates the flange portions 206 and 208 and in this embodiment, it can be seen that there is no vertical web between the respective flange portions and the space 218 . Also, it can be seen that the space 218 extends along a greater portion of arm 200 than does the embodiment shown in FIG. 12 . Thus, the cantilever arm portions of the arm of FIG. 14 are longer than the cantilever arm portions of the arm of FIG. 2 . Further, the cantilever arm portions of the arm of FIG. 14 are tapered along their length, such that the thickness of these portions is less near the pins than the semicircular portion 202 . Compare the thicker section of the arm of FIG. 15 shown in FIG. 19 with the thinner section of the arm taken nearer the pin 214 shown in FIG. 20 .
Even though the thickness of the cantilever arm portions of the arm of FIG. 15 have been reduced as compared to the arm of FIG. 2 , the width of these portions has been increased with respect to the arm of FIG. 2 . Compare the widths of the arm of FIG. 15 shown in FIGS. 19 and 20 with the width of the arm of FIG. 13 shown in FIG. 18 . The increased width of the improved arm of FIG. 15 provides a stiffness in the lateral plane that is about 8 times greater than the stiffness of the arm of FIG. 2 . This increased stiffness prevents most accidental lateral deflections of the pins and would likely require a determined intentional action to laterally deflect the cantilever arm portions and pins.
A male locking portion 220 is positioned inboard of pin 214 and a female locking portion 222 is correspondingly positioned inboard of pin 216 . The male and female locking portions are configured so as to be able to fittingly mate with one another when the two flanges portions 206 and 208 are pressed together. As seen in FIG. 16 , a section along line 16 - 16 in FIG. 15 , the female locking portion can be configured as a chevron-shaped slot Correspondingly, the male locking portion 220 would be configured as a chevron-shaped projection to mate with the chevron-shaped slot of female locking portion 222 . The male and female locking portions can also have different shapes, as long as they will lockingly mate together when the two flange portions are pressed together. As with the arm 34 above, the arm 200 can be flipped over to provide the second arm of the forehead support and thus, only one mold is needed to cast both required arms.
The lengths of the pins 214 and 216 are provided such that when the pins are pressed together to the extent allowed by the locking portions, the pins will clear the slots in the bridge, contrary to the pins of the related art arms.
In a preferred embodiment, these improved arms are constructed of a polycarbonate, specifically, Makrolon 2858 manufactured by Bayer.
There are several advantages to this improved arm embodiment. First, because the space 218 extends farther along the arm 200 , the lack of a web between the flanges 206 and 208 and the tapering of the cantilever arm portions, it is as easy or easier to press the pins 214 and 216 together when adjusting the forehead support, even with the increased lateral strength of the improved arms. This is especially important because during the adjustment while the mask is on the wearer's head, the wearer cannot easily see the forehead support as he or she is performing the adjustment. The increased lateral strength helps resist accidental lateral deflection of the cantilever arm portions and pins, as well as providing a stronger support to the airflow tube. The end result is that at the outer portion of the arm 200 near the pins, the extending portion 204 has a greater stiffness and resistance to bending in the lateral or horizontal direction (i.e., the pivoting direction) than it does in the vertical direction (the non-pivoting direction). This is contrary to the embodiment shown in FIGS. 11-13 where the stiffness and resistance to bending is greater in the vertical direction than in the horizontal direction.
Of course, the taper, shape and/or the thickness of the cantilevered arm portions can be altered to vary the stiffness of the cantilevered arm portions in the horizontal or vertical directions, as circumstances warrant. Further, under certain circumstances, it is contemplated that the stiffness of the cantilevered arm portions in the vertical direction can be less, similar to, or even greater than the comparable stiffness of the cantilevered arm portions of the related art design in the vertical direction.
The use of the wider flanges also allows the use of broader oval depressions 210 and 212 . These broader depressions better accommodate the wearer's fingers and thus, give the wearer a more positive and more comfortable grip on the arms during adjustment.
The provision of the male and female locking portions assures that the two flange portions remained aligned with one another during the pressing together of the pins 214 and 216 . Thus, the pins are also maintained in alignment during compression, making it easier for both pins to align with their respective slots in the bridge during adjustment of the bridge. Without the locking mechanism, the pins can be twisted and splayed with respect to another during compression, making it more difficult to position the pins in the desired respective slots in the bridge during adjustment. Further, the locking portions also prevent the user from laterally deflecting the pins with respect to one another when disassembling the arm from the bridge. Since the pins are short enough to clear the slots in the bridge when pressed together, the arm need not be rotated or the pins laterally displaced from one another to allow the pins to clear the slots in the bridge. This reduces that the chance that a user can operate the arms contrary to instructions and thereby place undue stresses on the arms that could lead to premature failure of the arms.
Finally, the provision of the undercut or recessed portions 236 and 238 on arc portions 230 and 232 reduces the amount of material of the arm that comes into contact with the airflow tube 12 (or other pivot point). This helps prevent sticking or binding of the arm as it is pivoted about the airflow tube during adjustment of the forehead support, as compared to the related arm embodiment. The radiused ends 240 and 242 are also less likely to catch and hang up on imperfections in the airflow tube during pivoting, as compared to the sharper ends of the related arm embodiment. Thus, the arm 200 more easily pivots about the airflow tube during adjustment of the forehead support.
These improvements in arm 200 thus make it easier to adjust the forehead support, as well as make it easier to disassemble the arms from the bridge to allow thorough cleaning of the bridge and other support components. They also help prevent actions by the user contrary to instructions that could increase the risk of breakage of the forehead support.
While several improvements have been discussed above, it is contemplated that an improved forehead support according to the present invention need not utilize all such improvements but can utilize one or more of such improvements in various combinations.
It is to be understood that while the invention has been described above in conjunction with preferred specific embodiments, the description and examples are intended to illustrate and not limit the scope of the invention. | The present invention discloses an adjustable forehead support for a nasal or full-face mask wherein the forehead support may be adjusted for the different shapes and sizes of a facial profile. The forehead support utilizes a dual-arm system that adjusts the position of the forehead support vis-á-vis the mask and/or airflow tube. The angle of the mask to the face may be adjusted with the present invention. | 0 |
BACKGROUND OF THE INVENTION
Conventional fabric fluid treatment processes designed to enhance the surface characteristics of fabrics have been limited to use on fabrics including spun yarns, in order that sufficient fiber free ends are available for the fluid treatment process to raise and entangle, and to form the surface effect. Conventionally, fluid treatment processes have not been considered to be effective on fabrics made primarily from filament fibers, such as all filament fabrics. One attempt to use a hydraulic treatment process to enhance an all-filament fabric is described in U.S. Pat. No. 5,806,155 to Malaney et al. That patent describes the use of a hydraulic treatment process to “uniformly and continuously” impact an all-filament woven fabric at a particular level of energy in order to achieve controlled porosity and uniform spacing of the yarns. However, as acknowledged by Malaney in that reference, there are no free fiber ends in the fabric to be entangled or which can be used to form a surface effect on the fabric. (For purposes of this invention, the term “surface effect” is intended to describe a nap or pile of fibers on the surface of the fabric, which provide it with a variety of characteristics, e.g. softness, increased compression, etc.)
Spun yarns are commonly used in the production of fabrics for a variety of end uses, in particular, where aesthetics such as a soft hand are desired. As will be readily appreciated by those of ordinary skill in the art, spun yarns are those made from a plurality of relatively short fibers (i.e. staple fibers) that are formed into a yarn that is typically held together by twist. Some disadvantages that are commonly associated with spun yarns are that they are often not as strong as their filament counterparts and they can tend to degrade during use and laundering, leading to the production of lint, fabric weight loss, and loss of fabric strength. In addition, fabrics made from spun yarns tend to retain soil to a greater extent than fabrics made from filaments.
Fabrics made from filaments thus are generally considered to have greater strength and soil release performance than those made from spun yarns, though they generally are not considered to be as soft or aesthetically pleasing as the fabrics made from spun yarns. Therefore, yarns made from filaments are often put through a texturing process designed to bulk out the filaments and make them more compressible and pleasant to the touch. However, fabrics made from the textured filaments are still considered to have only limited to no surface effect, and considerably less surface effect than a comparable fabric made from spun yarns.
One market that has capitalized on the features of filaments is the napery market, and in particular, the rental laundry market. The rental laundry market demands that the fabrics used in the manufacture of its tablecloths and napkins be highly durable, in order that the items can be re-used and laundered a large number of times. In addition, such items need to have good soil release, and need to have a good feel or hand, particularly when they will be used as napkins, since they will contact the user's face.
As noted above, filaments are considered to provide greater durability and soil release than spun yarns. As also noted previously, the fabrics made from filaments have a rough feel and limited to no surface effect. In an attempt to overcome this disadvantage, fabrics made from filaments are typically sanded or otherwise abraded to produce some cut fibers at the fabric surface. However, to achieve an amount of abrasion sufficient to alter the surface characteristics of the fabric, it is typically required that the fabric construction present sufficient available fiber lengths to the abrasion device, in order that an acceptable hand can be achieved at an acceptable level of strength. (See FIG. 1 , which illustrates the effect that abrasion intensity as applied to a plain weave fabric has on fabric tear strength.)
In order to present yarn floats that are sufficiently long to receive an effective amount of abrasion by the abrading process, it is customary to provide the fabrics in a 2×1 weave construction. (As will be readily appreciated by those of ordinary skill in the art, this construction provides a plurality of staggered yarn floats, where a yarn extending in one direction crosses over two or more yarns extending in the other direction. In this way, the float can be sufficiently acted upon by the abrasive action.) Not only does this construction provide greater fiber availability for the abrasion process, but this weave construction is typically considered to have better tear strength as compared with a plain weave construction made from the same yarns.
One problem posed by this construction is that the longer floats have a tendency to pick and snag. When this occurs, filaments or even a whole yarn are pulled outwardly from the fabric, resulting in an unsightly looking defect in the product. These picks and snags can occur routinely from fabric use or from the laundering process, and are a common cause of rental napery products being withdrawn from use. Despite the above-noted disadvantages associated with the 2×1 construction, prior to the present invention, it had been considered to be the only acceptable construction for a filament napery fabric with acceptable surface effects.
SUMMARY
The instant invention is directed to a process for making fabrics made from filaments have aesthetic characteristics simulating those of fabrics made from spun yarns. In addition, the invention is directed to fabrics having spun-like aesthetic characteristics made from filaments. Furthermore, the invention enables the achievement of fabrics having a durable soft hand, good fabric durability and strength, good soil release, good color retention, improved moisture transport and low pill characteristics as compared with similar fabrics made from spun yarns. In addition, the invention includes fabrics suitable for use in the rental napery market, which have a reduced tendency to pick and snag relative to other napery fabrics made from filaments.
The invention involves providing a fabric containing filaments, and subjecting the fabric to a pre-abrasion step. For example, the fabric can be sanded, brushed, napped, etc., with the goal being to abrade some of the filaments and form some cut fiber ends along the yarns. (For purposes of this disclosure, the term “cut fiber ends” is intended to encompass ends that are severed all the way through, as well as those formed through fiber fibrillation, which is a slicing or peeling of a portion of the fiber.)
The fabric is then subjected to a high energy fluid treatment process, which serves to act on the pre-abraded fabric and create a surface effect on at least one surface of the fabric and/or push cut fiber ends from one surface of the fabric through the dimension of the fabric toward or through to the other fabric surface. For example, the fabric can be treated with high pressure water, gas, or the like. (For purposes of this application, “high energy” is intended to encompass fluids at sufficient pressures and/or velocities to push cut fiber ends through the dimension of the fabric (i.e. invert the pile) and/or entangle fibers, as opposed to simply slightly displacing them, and to push fibers through and/or outwardly from the dimension of the fabric.) Where an amount of energy is described herein as being applied to a fabric, it is understood that those of ordinary skill in the art will recognize that the speed of the fabric through the treatment zone, the dimension of the treatment zone, the pressure and velocity of the fluid as it reaches the fabric, the fluid density and mass, the mass of the fabric presented to the fluid, and the time the fabric is exposed will be coordinated to achieve the desired level of energy application. In addition, the total energy may be applied to the fabric in one stage, through passage through a series of fluid treatment stages.
In the case of multiple treatment stages, they can be achieved by way of plural treatment stages in a single apparatus, or from multiple passes through a single fluid treatment apparatus. Typically, it would be expected that an energy of about 0.0295 horsepower-hr/lb of fabric would perform well in effectively entangling the fibers and raising the fibers to form the surface effect, although other energy levels are contemplated within the scope of the invention, depending on the treatment process utilized, the fabric treated, and the amount of surface effect desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical illustration of the effect that abrasion intensity has on the tear strength of a plain weave fabric;
FIG. 2 is a schematic illustration of a process according to the instant invention;
FIG. 3A is a photomicrograph (30× magnification, no tilt) of a fabric in its greige state;
FIG. 3B is a photomicrograph (30× magnification, no tilt) of the fabric shown in FIG. 3A , after it has been pre-abraded;
FIG. 3C is a photomicrograph (30× magnification, no tilt) of the fabric shown in FIG. 3A , after it has been abraded and fluid treated in the manner of the invention;
FIG. 4A is a photomicrograph (30× magnification, 45° tilt) of the fabric in FIG. 3A in its greige state;
FIG. 4B is a photomicrograph (30× magnification, 45° tilt) of the fabric shown in FIG. 4A , after it has been pre-abraded;
FIG. 4C is a photomicrograph (30× magnification, 45° tilt) of the fabric shown in FIG. 4A , after it has been abraded and fluid treated in the manner of the invention;
FIG. 5A is a photomicrograph (30× magnification, 75° tilt) of the fabric shown in FIG. 3A in its greige state;
FIG. 5B is a photomicrograph (30× magnification, 75° tilt) of the fabric shown in FIG. 5A , after it has been abraded;
FIG. 5C is a photomicrograph (30× magnification, 75° tilt) of the fabric shown in FIG. 5A , after it has been abraded and fluid treated in the manner of the invention;
FIG. 6A is a cross-sectional photomicrograph (30× magnification) of the fabric shown in FIG. 3A in its greige state;
FIG. 6B is a cross-sectional photomicrograph (30× magnification) of the fabric shown in FIG. 3B (abraded only);
FIG. 6C is a cross-sectional photomicrograph (30× magnification) of the fabric shown in FIG. 3C which had been abraded and fluid treated according to the invention;
FIG. 7A is an illustration of a cross-sectional view of a fabric which has been abraded on one side only;
FIG. 7B is an illustration of the fabric of FIG. 7A after it has been subjected to a fluid treatment step in accordance with the instant invention;
FIG. 7C is an illustration of a fabric made from spun yarns that has been abraded on one side only and subjected to a fluid treatment step in the manner set forth in the invention.
DETAILED DESCRIPTION
In the following detailed description of the invention, specific preferred embodiments of the invention are described to enable a full and complete understanding of the invention. It will be recognized that it is not intended to limit the invention to the particular preferred embodiment described, and although specific terms are employed in describing the invention, such terms are used in a descriptive sense for the purpose of illustration and not for the purpose of limitation.
The instant invention is directed to a process for enhancing the hand and aesthetic characteristics of fabrics. In particular, the process has been found to be particularly suitable in the enhancement of filament-containing fabrics. In one aspect of the invention, it has been found that fabrics made substantially or substantially entirely from filaments can be made to feel and appear substantially like fabrics made from spun yarns. This can be particularly desirable because fabrics having comparable levels of feel as those made from spun yarns can be achieved at greater levels of strength, durability, soil release, and/or levels of manufacturing ease and efficiency.
The fabric can be produced in any known manner, including but not limited to weaving, knitting, and nonwoven manufacturing processes. As will be appreciated by those of ordinary skill in the art, such fabrics include a plurality of fibers and/or yarns that are interwoven, interknit, or otherwise associated with each other to form a coherent stable structure.
The invention contemplates the use of any type of fibers, including but not limited to synthetic and non-synthetic fibers (e.g. polyester, nylon, rayon, silk, cotton, polylactide based fibers, PTT fibers, wool, aramids, etc.), single or multi-plied yarns, or the like.
The invention involves pre-abrading a fabric, then treating it with a high energy fluid. The pre-abrasion can be performed in any of a variety of ways. For example, the pre-abrading can be performed by processes including, but not limited to, sanding, brushing, napping, wet sueding, dry sueding, or processing by the sanding methods and/or apparatus described in commonly-assigned U.S. Pat. No. 6,233,795 to Dischler, U.S. Pat. No. 6,260,247 to Dischler et al., U.S. Pat. No. 6,269,525 to Dischler et al., U.S. Pat. No. 6,345,421 to Dischler et al., U.S. Pat. No. 4,468,844 to Otto, U.S. Pat. No. 4,512,065 to Otto, U.S. Pat. No. 5,943,745 to Dischler, U.S. Pat. No. 6,242,370 to Dischler, U.S. Pat. No. 5,815,896 to Dischler, and U.S. Pat. No. 5,752,300 to Dischler, the disclosures of which are incorporated herein by reference. For purposes of this disclosure, the term “sanding” is intended in its broadest sense to encompass all types of grits (e.g. sandpaper, sanding films, diamond plated rolls, three-dimensional abrasion such as by using Scotchbrite® grit available from 3M Corporation of St. Paul, Minn., etc.), and grit supports.
The fabric can be pre-abraded on one or both surfaces, according to the desired amount of surface effect. For example, in one aspect of the invention illustrated in FIGS. 7A and 7B , the fabric is pre-abraded on one surface ( FIG. 7A ) , with the fluid treatment serving to produce a surface effect on each of the fabric surfaces, by forcing some of the cut fiber ends of the abraded fibers through the fabric to the opposite fabric surface ( FIG. 7B ). Alternatively, both surfaces of the fabric can be pre-abraded within the scope of the instant invention.
The high energy fluid treatment can be of any variety that functions to entangle fibers within the fabric, including treatment with high pressure gas, treatment with high pressure liquid, or the like. For example, it has been found that a high pressure water treatment of the variety described in commonly-assigned co-pending U.S. patent application Ser. No. 09/344,596 to Emery et al, filed Jun. 25, 1999 works well in the invention. The disclosure of U.S. patent application Ser. No. 09/344,596 to Emery et al., filed Jun. 25, 1999, is incorporated herein by reference. However, other types of fluid treatment apparatus could be used within the scope of the invention, including but not limited to those described in U.S. Pat. No. 5,806,155 to Malaney et al.; U.S. Pat. No. 6,253,429 to Zolin; U.S. Pat. No. 5,632,072 to Simon et al.; and U.S. Pat. No. 6,343,410 to Greenway et al.; U.S. Pat. No. 5,791,028 to Zolin; U.S. Pat. No. 6,442,810 to Greenway et al.; U.S. Pat. No. 6,442,809 to Greenway et al.; U.S. Pat. No. 5,136,761 to Sternlieb et al.; U.S. Pat. No. 4,995,151 to Siegel et al.; U.S. Pat. No. 4,967,456 to Sternlieb et al., the disclosures of which are incorporated herein by reference. The high energy fluid treatment can be performed on both surfaces or on one surface only. As noted above, in some embodiments of the invention (such as when using the fluid treatment apparatus described above in the '596 application to Emery et al), a surface effect may be achieved on both surfaces of the fabric despite fluid treatment being performed only on a single side of the fabric.
As noted previously, the amount of energy applied can be selected to optimize the surface effect on the particular fabric being treated. In addition, the parameters of the particular treatment apparatus can be selected without undue experimentation to achieve the desired level of treatment, so that the desired level of surface effect is achieved for the particular fabric. It is expected that by treating a fabric with at least about 0.0295 hp-hr/lb of energy, a good surface effect could be achieved for many textile fabrics. In some embodiments of the invention, it has been found that an energy application of about 0.0295–0.118 hp-hr/lb achieves a good fabric.
It has surprisingly been found that by pre-abrading a fabric and in particular, a filament-containing fabric, the high energy fluid is able to dramatically change the surface of the fabric far beyond the effects of the abrasion alone. This unique combination of pre-abrasion and fluid treatment has been found to give filament-containing fabrics unique surface effects similar to those of fabrics made from spun yarns. In particular, while abraded fabrics have a flat and rough feel, the fabrics of the instant invention have a number of loopy filament ends that are exposed to the surface, which form a cushioned surface effect. In other words, fibers from both the warp and filling are affected (in contrast to many other processes that affect only one set of yarns) and a plurality of short round loops with free ends are produced, with the fibers being entangled with those from other adjacent yarns, to form a dense cover of fibers.
In addition, the cut fiber ends had a length of about 1–1½ floats, which resulted in a unique short, soft surface effect, with the fibers being entangled with other adjacent fibers, and throughout the thickness dimension of the fabric. In contrast, surface effects produced from conventional processes such as brushing result in long pulled fibers that do not form a cohesive entangled surface effect. This short fiber feature is of particular advantage because long pulled fibers have a tendency to exacerbate fabric pilling. Therefore, in one aspect of the invention, it is desirable that the pre-abrasion and fluid treatment processes be performed to produce cut fiber ends having a length of about 1.5 float lengths or less.
Intermediate steps such as dyeing, chemical treatment, etc. can be performed where desired, either before pre-abrasion, after pre-abrasion but before fluid treatment, or after fluid treatment. In addition, the pre-abrasion and fluid treatment operations can be performed in-line, or as separate operations. Following fluid treatment, the fabric can be finished in a conventional manner. Conventional chemistries such as soil release chemicals, wicking agents, handbuilders, anti-stats, etc. can also be added at any desired point in the process.
The fabrics produced by the process of the invention have a variety of unique combinations. Of particular significance is the fact that fabrics made from filaments can be made to look and feel like fabrics made from spun yarns. In this way, a unique fabric which has the desirable properties associated with filaments (e.g. strength, low linting, good soil release and the like) can be achieved but with the aesthetic characteristics associated with fabrics made from spun yarns.
As will be readily appreciated by those of ordinary skill in the art, the fabrics of the invention have utility in a broad range of end uses where a surface effect is desired, including but not limited to napery, home furnishings, apparel of all types, industrial products, upholstery, shower curtains, draperies, shades, aprons, linings, bedding, casket linings, flags, labels, bandages, ribbons, etc.
In the specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purpose of limitation, the scope of the invention being defined in the claims. | A process for face finishing fabrics, and in particular fabrics containing filaments, to provide them with good aesthetic characteristics is described. In addition, fabrics made from filaments having aesthetic characteristics and surface effects similar to those of fabrics made from spun yarns are described. Also, items of napery made from filaments and having good surface effects and low pick and snag performance are described. The process involves pre-abrading a fabric, such as one made from filaments, and then subjecting it to a high energy fluid treatment process. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a ball valve assembly which can be made sufficiently large and robust to be installed in a pipeline, particularly an undersea oil pipeline. It may also be applied on a smaller scale.
A ball valve has a body with a through passage, and a rotatable ball member located in the body. The ball member has a through passage, and may be rotated between an "open" configuration. in which its through passage is in line with the through passage of the body, and a "closed" configuration in which the two through passages are no longer in register. The rotation of the ball member is generally effectable about a single axis transverse to the through passage of the body.
This general type of valve has been found to be the most suitable for use under arduous conditions such as in undersea oil pipelines, where large pressures are involved. In the known type of assembly, the body is closed by a bonnet which is secured by a multiplicity of bolts. It is periodically necessary to service the valve, particularly to repair or replace the seals. This requires a team of divers to descend to the seabed, and to remove the bonnet after undoing the bolts (which are likely to be severely corroded). Even after the bonnet has been removed, the operation is difficult. It is quite likely that the pipeline will have to be shut down for a period of two or three weeks. The costs involved are very substantial, e.g. of the order of 200,000 (Sterling).
SUMMARY OF THE INVENTION
According to the present invention in a first aspect, there is provided a ball valve assembly comprising a core unit adapted to be releasably inserted in a complementary body in a pipeline, the core unit comprising a core assembly having a through passage for a flow in the pipeline, and a ball member to berotatably mounted within the core assembly and having a through passage such that rotation moves it into and out of communication with the passage in the core assembly; whereby the core unit can be removed from the pipeline and replaced by a like unit. Preferably the core unit includes seals for sealing to the body, which need only provide suitable surfaces for sealing contact, all the replaceable parts being in the core unit.
Preferably, the core unit is tapered to fit a tapered socket provided by the body. The mating surfaces may be frustoconical. There may be annular seals retained in grooves in the conical surface of the core unit.
The core unit may be retained in the body by a bonnet having a peripheral flange arranged to overlie a like flange associated with the body and to be releasably clamped thereto by a circumferential clamp which holds the two flanges together and can be moved away after release at a single location. For example, a manacle clamp may consist of two (or more) pivotally connected sections pivotable to define a circular collar of inwardly opening channel section for embracing the flanges; the end portions of the end sections being connectable together.
The core assembly may be in two parts, separable to permit removal of the ball member (after removal from the body).
The sealing between the ball member and the core assembly may employ a floating annular seal, attached neither to the ball member nor the assembly, so as to be self-centering on the ball member. There may be camming means associated with the ball member and seal to lift off the seal on rotation of the ball member. The seals may be arranged so that fluid pressure within the through passages urges sealing contact. There may be spring means for enhancing sealing at low fluid pressure.
In another aspect the invention provides a pipeline portion comprising a body and a core unit.
In a third aspect the invention provides a method of repairing or servicing a pipeline portion which includes a said ball valve assembly, which method comprises unplugging the core unit and inserting a replacement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section through a ball valve assembly embodying the invention;
FIG. 2 is an enlarged detail of FIG. 1, showing a sealing assembly for the ball member;
FIG. 3 is a perspective view of the core unit;
FIG. 4 is a perspective view of the body after removal of the core unit;
FIG. 5 is a detail of a view similar to FIG. 2 showing a modified seal arrangement;
FIGS. 6A to D are views of seal types; and
FIG. 7 is a perspective view of a second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 to 4, the body 10 has, at upstream and downstream ends, flanges 12 for use in coupling lengths of pipeline. (Of course, other means of connection--e.g. welding--could be used.) Between these connecting flanges 12 the body 10 defines a generally conical chamber 14 whose axis is transverse to the axis of the pipeline, and will generally be vertical. The conical chamber 14 is closed at the bottom by a cylindrical cup portion 16. It is open at the top, where there is a generally cylindrical portion 18 and a peripheral flange 20 which projects radially outwardly.
The valve core 22 comprises a generally frustoconical main portion 24 shaped and dimensioned so as to fit within the conical chamber 14 . A lower, generally cylindrical, portion 25 extends into the cup portion 16 and seats on an annular damper 27. The core's main portion 24 has a through passage 26.
The valve core 22 is formed of two like portions, the join being substantially in an axial plane. To ensure sealing, the abutment faces may be coated with an inert sealant material. Adjacent the join line the frustoconical body portion 24 has pairs of scalloped recesses 28, the two recesses 28 of each pair being located on either side of the join line and connected by a through bore. Bolts 30 pass through the bores and receive nuts 32 on their free ends, for holding together the two halves of the core 22.
Internally, the valve core 22 has a valve chamber 34 for receiving a ball member 36. Portions of a shaft 38 extend axially above and beneath the ball member 36. They are formed with it as a unitary drop-forging, so there will be no problems due to crevice corrosion. The lower portion extends into a bearing cavity 40 in which it is journalled. Above the chamber 34, the shaft 38 extends above the valve core 22 (via a seal 42) and above the body 10. The ball member 36 is rotatable in the valve chamber 34 by means of the shaft 38. There are bearing surfaces 41 on the axial end walls of the valve chamber 34 and on the cylindrical wall of the cavity 40.
The ball member 36 has a through passage 44, of large circular cross-section similar to that of the through passage in the valve core 22. Rotation of the ball member 36 by quarter of a turn opens or closes the valve by moving the through passage 44 between an open configuration in which it is in line with the through passage 26, and a closed configuration in which the through passage 44 of the ball member 36 is perpendicular to the through passage 26 of the valve core 22, so that it is closed by the wall of the valve core.
At either side of the ball member 36 there are respective annular seal means 46 which, when the ball member 36 is in its open configuration, surround the mouths of the through passage 44. On either side of the through passage 44, and adjacent the seal means 46, there are respective annular cam surfaces 48 for cooperating with the seal means 46. Referring to FIG. 2, which shows a seal means 46 in greater detail, it can be seen that the seal means 46 includes a seal ring 50. This is of a hard material, such as stainless steel or an inert hard plastic. It serves to hold and support a softer insert 52. This is still quite hard, owing to the high pressures to which it is likely to be subjected, and the need to avoid creep. Thus, it may, for example, be made of PTFE or nylon. It has a sealing surface 54 which is concave and arranged and dimensioned for abutting the spherical surface of the ball member 36. The seal ring 50 and insert 52 are not attached either to the ball member 36 or the valve body 22, but instead float. Thus the sealing surface 54 can be urged sealingly against the ball member 36, without there being serious problems of maintaining concentricity of the seal. The seal ring 50 abuts the cam surface 48 on rotation of the ball member 36.
A further portion of the seal means 46 is located largely within an annular cavity 56 in the valvecore 22, opening towards the ball member 36. There is a further annular seal ring 58 located in a chamber defined on the radially outer side by the outer wall of the annular cavity 56, and on the other sides by two seal housing members 60,62, which engage together so as to be relatively slidable in the axial direction of the annular cavity 56 and seal 58. This is to allow for the variation in size of the seal ring 58 with varying stresses. One of the housing members 62 is in contact with an end portion of the insert 52 associated with the other seal ring 50. At the other axial side of the annular cavity 56, the other housing member 60 abuts a resilient means, suitably a disc spring e.g. of Bellville washer type, located within the cavity 56. Thus the housing member 60 is urged to compress the seal ring 58 and the insert 52. The housing members 60,62 are penetrated by axial bores 64 to communicate the region of the cavity 56 beyond (axially outward of) the housing members 60,62 with the through passages 26 and 36, via a gap 66 between the housing member 62 and the ball member 36. Thus liquid under pressure in the through passages is conducted to the rear of the housing member 60, to urge it to enhance sealing. There may be a wiper seal (not shown) in the gap 66 to exclude sand and detritus, which might otherwise get between the seals and the surfaces against which they should seat.
Part of an alternative seal means 246 is shown in FIG. 5. Instead of the housing members 60,62 there is a single annular piston 200, which may be of metal. Its cross-section is substantially rectangular, with two annular cavities 202, in the radially inner side containing bearings 204, and two annular cavities 206,208 in the radially outer side The cavity 206 on the axially inner side contains a bearing 210. The outer cavity 208 contains a sealing ring 212. This is preferably a spring energised PTFE seal. The three bearings 204,210 prevent metal-metal contact, and allow the pressure medium (generally oil from the pipeline) to pass, but not sand and grit, which might damage the sealing ring 212. Some pressure medium will get past the seal means 246, into the body cavity between the ball member 36 and the core 22. If the pressure in the pipeline is released, there is a tendency for this "escaped" medium to remain at high pressure, which could be dangerous. However, the preferred seal arrangement has the ring 212 arranged to act like a valve, resisting strongly the outward passage of oil but allowing its return easily. Thus the "body cavity relief pressure" is very low.
The seal means 46 or 246 are required to function primarily when the ball member 36 is in its open configuration. They are generally urged forcefully into sealing contact, which tends to make it difficult to turn the ball member 36. To reduce this problem, there may be a cam surface 48 as shown. This is arranged to interact with the axial end face 68 of the seal ring 50, so that as the ball member 36 begins to turn, the seal ring 50 is moved away from it (to the left in FIG. 2), so that the sealing surface 54 is lifted off the ball member 36. This condition may persist until the ball member 36 returns to the open configuration. Alternatively, the cam may be shaped so that the sealing surface 54 moves back into contact in a closed configuration of the ball member 36 after it has turned through a predetermined angle.
In addition to the sealing between the ball member 36 and the valve core 22, there are seal means 80 between the valve core 22 and the body 10. These principally comprise resilient O-rings in annular grooves on the valve core 22. However, the shape of the surface of the valve body 22 is rather complicated, being part of the surface of a cone. Thus, in use, the O-rings are not planar. They therefore tend to become unseated from the grooves. To resist this, the grooves 82 may be formed not with simple U-sections, but with sections having narrowed mouths, at least over part of their extent. (A less favoured alternative would be to use simple grooves 82 and to adhere the rings in place. Of course, both methods of retaining the rings could be used.) We may use grooves 82 having a dovetail section (FIG. 6A).
In fact, we have found that such complex grooves can be avoided. If a conventional seal (O-ring or quadrate: FIG. 6B) is of such an intrinsic size that it must be stretched (e.g. by 2%) to fit the groove, its resilient force suffices to keep it in place.
For use in severe conditions, a spring-energised PTFE seal is preferred. As shown in FIG. 6C, this has a PTFE body 250 (which may be loaded with glass or carbon) with a cross-section in the form of a "U" with diverging arms. These are urged apart by a metal spring 252 of an alloy resistant to sour gas. The base of the "U" has an annular nib 254. This seal fits in a groove having a recess 256 for receiving the nib 254. One arm of the "U" abuts the body of the pipeline portion 10. With a conventional seal ring, if high pressures are to be withstood it is essential that the gap between the core 22 and the body 10 should be small (e.g. under 75 μm), or the seal is likely to be extruded out through the gap. A seal as shown in FIG. 6C can be used with a much larger gap, e.g. 450 μm. It is also extremely resistant to "sour gas" (containing H 2 S) and other corrosive media, which tend to attack conventional seals. There is little or no risk of explosive decompression.
For even more arduous conditions (such as high temperatures) a seal ring similar to that shown in FIG. 6C but made of PTFE-coated metal (spring-energised) may be used.
If the resistance to blow-out at high pressures and large gap-sizes is required, but the corrosion-resistance of PTFE is not necessary, the arrangement of FIG. 6D may be employed. This uses a conventional O-ring 260 (or, e.g., a quadrate ring) radially inwardly of a retainer ring 262. The ring 262 has a nib 264 received in a recess 266, as in FIG. 6C. Its exposed outer face 268 is angled so as to bridge the gap and abut the pipeline body 10 adjacent the O-ring 260. It is of a fairly hard material with a degree of resilience, e.g. PTFE.
Generally, energised PTFE seals are preferred for all sealing in the ball valve assembly.
A bonnet 84 is fast with the valve core 22, being secured to it by means of bolts 86. The shaft 38 of the ball member 36 passes rotatably through the bonnet 84, via a cylindrical bearing surface 85 (which is non-metallic, to avoid electrolytic action) and a seal 87 whose principal purpose is to keep seawater out. The seal may employ a sealing ring of nitrile rubber or, more preferably, of spring energised PTFE. The bonnet 84 has a peripheral flange 88 dimensioned to overlie the flange 20 of the body 10. The flanges 88 and 20 have respective upper and lower bevelled surfaces 90,92 which together define a wedge. They can be clamped together by means of a manacle clamp 94, one half of which is shown schematically in FIG. 4. As seen there, the body 10 is formed externally with a support bracket 96 bearing an upwardly directed pivot 98 on which is journalled one half of the clamp 94. This has an approximately semi-circular arm portion 100 having a radially inwardly directed channel section. At the distal end, the arm portion 100 has a clamping portion 102. The two portions 100 can be swung together about the pivot 98 so that their clamping portions 102 are near one another. The wedge defined by the bevelled surfaces 90,92 is then received partly within the complementary channel section of the arms 100. Further drawing together of the arms 100, e.g. by means of a nut and bolt passing through the clamping portions 102, forces the flanges 20,88 tightly together by the wedging action. Thus the bonnet 84 can be held on firmly by means of a single bolt, or other type of fixture, e.g. a quick-release fastener. (The clamp 94 need not be pivotted to the pipeline portion. Release could then free it.)
When the valve is closed, the pressure of fluid in the pipeline may provide a very large force on the valve assembly. This force could be ultimately borne by the plurality of bolts which hold down the bonnet. However, preferably, as in the illustrated embodiment, the force is taken by load-bearing surfaces fast with the valve core 22. One of these is provided by an annular thickening 104 on that lower, cylindrical portion 25 of the valve core 22 which projects into the cylindrical cup portion 16 of the body 10. (The surface could alternatively be provided on a separate clamp member.) Another is provided by a similar thickening 106 on the bonnet 84, spaced some way beneath the flange 88 thereof.
In use, when it is required to repair or service some parts of the valve assembly, it is merely necessary to undo the simple means holding the manacle clamp shut. (This preferably involves a simple overcentering cam arrangement, with no bolts which are liable to corrosion.) Then the unitary assembly of bonnet 84, valve core 22, and ball member 36 can simply be lifted out, and immediately replaced by anotner unit. The removed unit can be taken to a convenient location for servicing. The time for which the pipeline is out of operation is very much reduced as compared with conventional systems. The replacement unit slips into the conical socket in the body 10 simply, and accurate location is given by the sealing means 80. The manacle clamp is then swiftly secured. The removed unit may be repaired on the ship or ashore. The bonnet 84 may be removed by undoing the bolts 86. The valve core 22 may be taken apart by undoing the bolts 30, and the ball member 36 can then be attended to, and the seal means 46 repaired. The removable unit includes all of the components (such as seals) which are likely to need repair or replacement. The pipeline portion, which remains on the sea bed, provides only simple mating and sealing surfaces.
It will be appreciated that the above described assembly has numerous features which may be useful in contexts other than that described. We would particularly point out the ingenious nature of the seal means 46 and 246, e.g. using the floating ring 50, the cam surface 48 and the displaceable housing members 60,62 which are arranged to be urged to enhance sealing both by means of springs and by the pressure of the fluid within the pipeline. This latter "double urging" feature means that good sealing can be assured at relatively low pressures (when the disc springs are effective) and at higher pressures, since the sealing force automatically rises in step with the fluid pressure. This is to be contrasted with prior art sealing means, which could generally work well at only one end of the pressure range.
The cam surfaces 48 may be provided by separate cam elements (here rings) which are removably located on the ball member. They can be removed for servicing or replacement, e.g. to alter the camming action. Thus it might be desired to alter the turning angle over which sealing contact is maintained, or to cause the sealing surfaces 54 to lift off only at one (upstream or downstream) side.
It may be pointed out that friction with the seals is normally a major cause of wear in ball joints; and this is much ameliorated by our use of camming. This may be applied to many types of valve.
The seals 46,80 which surround the through-passage are radially outside it. Thus the pipeline, including the valve assembly, can be cleaned by pigging without risk to the seals.
As shown in FIG. 3, the halves of the valve core 22 are held together by bolts 30 in recesses 28 in the body portion 24. The cylindrical upper and lower (25) portions have no provision for holding means (except that the upper portion is secured to the bonnet 84 by bolts 86). A constructional form which can provide greater strength involves providing upper and lower peripheral flanges, similar to the flange 20 of the pipeline portion 10. The valve body 22 is then secured to top and bottom bonnets or caps which have complementary flanges. These may be held releasably in place by manacle clamps (operating much like the clamp 94), or by means of bolts. The lower load-bearing surface may be provided by the bottom cap, instead of by a thickening 104 integral with the body 22.
FIG. 7 shows a second embodiment of the invention. In essence it is the same as the first embodiment, and corresponding parts are given corresponding reference numerals raised by 500.
The body of the pipeline portion 510 has the flanges replaced by abutment surfaces 512 emerging almost directly from the conical chamber 514. This, and additional stiffening, give a very rigid construction, capable of withstanding great forces without bending. Thus servicing can be carried out reliably, even for pipelines at great depths. Internally, the conical chamber has a ceramic (e.g. alumina) coating, to avoid corrosion (e.g. due to bimetallic effects) and to provide a good mating surface for the seals 580 of the core 522. The manacle clamp 594 is separate from the body 510. Its mating surface has a coating e.g. of woven PTFE, which gives high bearing strength and insulation (preventing bimetallic corrosion). The body flange 520 has recesses 520' for receiving protrusions 584' that project beneath the bonnet 584, for ensuring correct rotational location. This is advantageous for remote assembly, by robot. The body may have docking lugs, for location of a robot vessel or tool.
The core 522 is substantially all of stainless steel. Its form is simplified, without a lower cylindrical spigot portion 25. However, the lower portion 525 has a thick plastics coating, e.g. of high density polyethylene. This protects the ceramic coating of the chamber 514 during assembly and removal, and also serves as a buffer. The halves of the core 522 may be held together by bolts and nuts in scalloped recesses, like those (30,32,28) of the first embodiment. However the bonnet 584 is secured differently: instead of bolts 86 we use a manacle clamp 586 which holds together an upper flange on the core 522 and a lower flange on the bonnet 584.
It will be appreciated that features described in connection with one embodiment may generally be combined with features from another, to suit particular circumstances. Plainly, for severe conditions it is necessary to have appropriately resistant components, e.g. a stainless steel core and all seals of PTFE. But if less is to be feared from high pressures, corrosion, sour gas and other hazards, then less expensive alternatives may be appropriate. | A ball valve assembly comprising: a body providing a socket and flow ports communicating therewith; and a core unit comprising a core assembly adapted to be releasably inserted into said socket, the core assembly having a through passage arranged to communicate with said flow ports, and a rotatable ball member within the core assembly, said member having a through passage such that rotation moves it into and out of communication with the passage in the core assembly. | 8 |
[0001] This application is a continuation of U.S. application Ser. No. 11/178,415 (now U.S. Pat. No. 8,034,360) filed Jul. 12, 2005, which is a continuation of U.S. application Ser. No. 09/857,691 (now U.S. Pat. No. 6,972,128) filed Sep. 5, 2001, which is a national stage of PCT/GB99/04129 filed Dec. 9, 1999. The entire contents of the above-identified applications are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention is concerned with agents for the treatment of primary, metastatic and residual cancer in mammals (including humans) by inducing the immune system of the mammal or human afflicted with cancer to mount an attack against the tumour lesion. In particular, the invention pertains to the use of whole-cells, derivatives and portions thereof with or without vaccine adjuvants and/or other accessory factors. More particularly, this disclosure describes the use of particular combinations of whole-cells and derivatives and portions thereof that form the basis of treatment strategy.
BACKGROUND TO THE INVENTION
[0003] It is known in the field that cancerous cells contain numerous mutations, qualitative and quantitative, spatial and temporal, relative to their normal, non-cancerous counterparts and that at certain periods during tumour cells' growth and spread a proportion of these are capable of being recognised by the hosts' immune system as abnormal. This has led to numerous research efforts world-wide to develop immunotherapies that harness the power of the hosts' immune system and direct it to attack the cancerous cells, thereby eliminating such aberrant cells at least to a level that is not life-threatening (reviewed in Maraveyas, A. & Dalgleish, A. G. 1997 Active immunotherapy for solid tumours in vaccine design in The Role of Cytokine Networks, Ed. Gregoriadis et al., Plenum Press, New York, pages 129-145; Morton, D. L. and Ravindranath, M. H. 1996 Current concepts concerning melanoma vaccines in Tumor Immunology—Immunotherapy and Cancer Vaccines, ed. Dalgleish, A. G. and Browning, M., Cambridge University Press, pages 241-268. See also other papers in these publications for further detail).
[0004] Numerous approaches have been taken in the quest for cancer immunotherapies, and these can be classified under five categories:
Non-Specific Immunotherapy
[0005] Efforts to stimulate the immune system non-specifically date back over a century to the pioneering work of William Coley (Coley, W. B., 1894 Treatment of inoperable malignant tumours with toxins of erisipelas and the Bacillus prodigosus. Trans. Am. Surg. Assoc. 12: 183). Although successful in a limited number of cases (e.g. BCG for the treatment of urinary bladder cancer, IL-2 for the treatment of melanoma and renal cancer) it is widely acknowledged that non-specific immunomodulation is unlikely to prove sufficient to treat the majority of cancers. Whilst non-specific immune-stimulants may lead to a general enhanced state of immune responsiveness, they lack the targeting capability and also subtlety to deal with tumour lesions which have many mechanisms and plasticity to evade, resist and subvert immune-surveillance.
Antibodies and Monoclonal Antibodies
[0006] Passive immunotherapy in the form of antibodies, and particularly monoclonal antibodies, has been the subject of considerable research and development as anti-cancer agents. Originally hailed as the magic bullet because of their exquisite specificity, monoclonal antibodies have failed to live up to their expectation in the field of cancer immunotherapy for a number of reasons including immune responses to the antibodies themselves (thereby abrogating their activity) and inability of the antibody to access the lesion through the blood vessels. To date, three products have been registered as pharmaceuticals for human use, namely Panorex (Glaxo-Wellcome), Rituxan (IDEC/Genentech/Hoffman la Roche) and Herceptin (Genentech/Hoffman la Roche) with over 50 other projects in the research and development pipeline. Antibodies may also be employed in active immunotherapy utilising anti-idiotype antibodies which appear to mimic (in an immunological sense) cancer antigens. Although elegant in concept, the utility of antibody-based approaches may ultimately prove limited by the phenomenon of ‘immunological escape’ where a subset of cancer cells in a mammalian or human subject mutates and loses the antigen recognised by the particular antibody and thereby can lead to the outgrowth of a population of cancer cells that are no longer treatable with that antibody.
Subunit Vaccines
[0007] Drawing on the experience in vaccines for infectious diseases and other fields, many researchers have sought to identify antigens that are exclusively or preferentially associated with cancer cells, namely tumour specific antigens (TSA) or tumour associated antigens (TAA), and to use such antigens or fractions thereof as the basis for specific active immunotherapy.
[0008] There are numerous ways to identify proteins or peptides derived therefrom which fall into the category of TAA or TSA. For example, it is possible to utilise differential display techniques whereby RNA expression is compared between tumour tissue and adjacent normal tissue to identify RNAs which are exclusively or preferentially expressed in the lesion. Sequencing of the RNA has identified several TAA and TSA which are expressed in that specific tissue at that specific time, but therein lies the potential deficiency of the approach in that identification of the TAA or TSA represents only a “snapshot” of the lesion at any given time which may not provide an adequate reflection of the antigenic profile in the lesion over time. Similarly a combination of cytotoxic T lymphocyte (CTL) cloning and expression-cloning of cDNA from tumour tissue has lead to identification of many TAA and TSA, particularly in melanoma. The approach suffers from the same inherent weakness as differential display techniques in that identification of only one TAA or TSA may not provide an appropriate representation of a clinically relevant antigenic profile.
[0009] Over fifty such subunit vaccine approaches are in development for the treatment of a wide range of cancers, although none has yet received marketing authorisation for use as a human pharmaceutical product. In a similar manner to that described for antibody-based approaches above, subunit vaccines may also be limited by the phenomenon of immunological escape.
Gene Therapy
[0010] The majority of gene therapy trials in human subjects have been in the area of cancer treatment, and of these a substantial proportion have been designed to trigger and/or amplify patients' immune responses. Of particular note in commercial development are Allovectin-7 and Leuvectin, being developed by Vical Inc for a range of human tumours, CN706 being developed by Calydon Inc for the treatment of prostate cancer, and StressGen Inc.'s stress protein gene therapy for melanoma and lung cancer. At the present time, it is too early to judge whether these and the many other immuno-gene therapies' in development by commercial and academic bodies will ultimately prove successful, but it is widely accepted that commercial utility of these approaches are likely to be more than a decade away.
Cell-Based Vaccines
[0011] Tumours have the remarkable ability to counteract the immune system in a variety of ways including: downregulation of the expression of potential target proteins; mutation of potential target proteins; downregulation of surface expression of receptors and other proteins; downregulation of MHC class I and II expression thereby disallowing direct presentation of TAA or TSA peptides; downregulation of co-stimulatory molecules leading to incomplete stimulation of T-cells leading to anergy; shedding of selective, non representative membrane portions to act as decoy to the immune system; shedding of selective membrane portions to anergise the immune system; secretion of inhibitory molecules; induction of T-cell death; and many other ways. What is clear is that the immunological heterogeneity and plasticity of tumours in the body will have to be matched to a degree by immunotherapeutic strategies which similarly embody heterogeneity. The use of whole cancer cells, or crude derivatives thereof, as cancer immunotherapies can be viewed as analogous to the use of whole inactivated or attenuated viruses as vaccines against viral disease. The potential advantages are:
(a) whole cells contain a broad range of antigens, providing an antigenic profile of sufficient heterogeneity to match that of the lesions as described above; (b) being multivalent (i.e. containing multiple antigens), the risk of immunological escape is reduced (the probability of cancer cells ‘losing’ all of these antigens is remote); and (c) cell-based vaccines include TSAs and TAAs that have yet to be identified as such; it is possible if not likely that currently unidentified antigens may be clinically more relevant than the relatively small number of TSAs/TAAs that are known.
[0015] Cell-based vaccines fall into two categories. The first, based on autologous cells, involves the removal of a biopsy from a patient, cultivating tumour cells in vitro, modifying the cells through transfection and/or other means, irradiating the cells to render them replication-incompetent and then injecting the cells back into the same patient as a vaccine. Although this approach enjoyed considerable attention over the past decade, it has been increasingly apparent that this individually-tailored therapy is inherently impractical for several reasons. The approach is time consuming (often the lead time for producing clinical doses of vaccine exceeds the patients' life expectancy), expensive and, as a ‘bespoke’ product, it is not possible to specify a standardised product (only the procedure, not the product, can be standardised and hence optimised and quality controlled). Furthermore, the tumour biopsy used to prepare the autologous vaccine will have certain growth characteristics, interactions and communication with surrounding tissue that makes it somewhat unique. This alludes to a potentially significant disadvantage to the use of autologous cells for immunotherapy: a biopsy which provides the initial cells represents an immunological snapshot of the tumour, in that environment, at that point in time, and this may be inadequate as an immunological representation over time for the purpose of a vaccine with sustained activity that can be given over the entire course of the disease.
[0016] The second type of cell-based vaccine and the subject of the current invention describes the use of allogeneic cells which are genetically (and hence immunologically) mismatched to the patients. Allogeneic cells benefit from the same advantages of multivalency as autologous cells. In addition, as allogeneic cell vaccines can be based on immortalised cell lines which can be cultivated indefinitely in vitro, thus this approach does not suffer the lead-time and cost disadvantages of autologous approaches. Similarly the allogeneic approach offers the opportunity to use combinations of cells types which may match the disease profile of an individual in terms of stage of the disease, the location of the lesion and potential resistance to other therapies.
[0017] There are numerous published reports of the utility of cell-based cancer vaccines (see, for example, Dranoff, G. et al. WO 93/06867; Gansbacher, P. WO 94/18995; Jaffee, E. M. et al. WO 97/24132; Mitchell, M. S. WO 90/03183; Morton, D. M. et al. WO 91/06866). These studies encompass a range of variations from the base procedure of using cancer cells as an immunotherapy antigen, to transfecting the cells to produce GM-CSF, IL-2, interferons or other immunologically-active molecules and the use of ‘suicide’ genes. Groups have used allogeneic cell lines that are HLA-matched or partially-matched to the patients' haplotype and also allogeneic cell lines that are mismatched to the patients' haplotype in the field of melanoma and also mismatched allogeneic prostate cell lines transfected with GM-CSF.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention will now be described with reference to the following examples, and the Figures in which:
[0019] FIGS. 1A , 1 B and 1 C show T-cell proliferation data for patients 112, 307, and 406;
[0020] FIGS. 2A , 2 B and 2 C show Western Blot analysis of serum from patients 115, 304 and 402;
[0021] FIGS. 3A , 3 B and 3 C show shows antibody titres of serum from patients 112,305 and 402;
[0022] FIGS. 4A , 4 B and 4 C show shows PSA data for patients 110, 303 and 404; and
[0023] FIG. 5 shows survival curves for C57 mice immunised with normal melanocyte.
DESCRIPTION OF THE INVENTION
[0024] The invention disclosed here relates to a product comprised of a cell line or lines intended for use as an allogeneic immunotherapy agent for the treatment of cancer in mammals and humans.
[0025] All of the studies of cell-based cancer vaccines to date have one feature in common, namely the intention to use cells that contain at least some TSAs and/or TAAs that are shared with the antigens present in patients' tumour. In each case, tumour cells are utilised as the starting point on the premise that only tumour cells will contain TSAs or TAAs of relevance, and the tissue origins of the cells are matched to the tumour site in patients.
[0026] A primary aspect of the invention is the use of immortalised normal, non-malignant cells as the basis of an allogeneic cell cancer vaccine. Normal cells do not posses TSAs or relevant concentrations of TAAs and hence it is surprising that normal cells as described herein are effective as anti-cancer vaccines. The approach is general and can be adapted to any mammalian tumour by the use of immortalised normal cells derived from the same particular tissue as the tumour intended to be treated. Immortalised normal cells can be prepared by those skilled in the art using published methodologies, or they can be sourced from cell banks such as ATCC or ECACC, or they are available from several research groups in the field.
[0027] For prostate cancer, for example, a vaccine may be based on one or a combination of different immortalised normal cell lines derived from the prostate which can be prepared using methods reviewed and cited in Rhim, J. S. and Kung, H-F., 1997 Critical Reviews in Oncogenesis 8(4):305-328 or selected from PNT1A (ECACC Ref No: 95012614), PNT2 (ECACC Ref No: 95012613) or PZ-HPV-7 (ATCC Number: CRL-2221).
[0028] A further aspect of the invention is the addition of TSAs and/or TAAs by combining one or more immortalised normal cell line(s) with one, two or three different cell lines derived from primary or metastatic cancer biopsies.
[0029] All the appropriate cell lines will show good growth in large scale cell culture and sufficient characterisation to allow for quality control and reproducible production.
[0030] The cell lines are lethally irradiated utilising gamma irradiation at 20-400 Gy to ensure that they are replication incompetent prior to use in the mammal or human.
[0031] The cell lines and combinations referenced above, to be useful as immunotherapy agents must be frozen to allow transportation and storage, therefore a further aspect of the invention is any combination of cells referenced above formulated with a cryoprotectant solution. Suitable cryoprotectant solutions may include but are not limited to, 10-30% v/v aqueous glycerol solution, 5-20% v/v dimethyl sulphoxide or 5-20% w/v human serum albumin may be used either as single cryoprotectants or in combination.
[0032] A further embodiment of the invention is the use of the cell line combinations with non-specific immune stimulants such as BCG or M. Vaccae , Tetanus toxoid, Diphtheria toxoid, Bordetella Pertussis , interleukin 2, interleukin 12, interleukin 4, interleukin 7, Complete Freund's Adjuvant, Incomplete Freund's Adjuvant or other non-specific agents known in the art. The advantage is that the general immune stimulants create a generally enhanced immune status whilst the combinations of cell lines, both add to the immune enhancement through their haplotype mismatch and target the immune response to a plethora of TAA and TSA as a result of the heterogeneity of their specific origins.
[0033] The invention here relates to a product comprised of a cell line or lines intended for use as an allogeneic immunotherapy agent for the treatment of cancer in mammals and humans. All of the studies of cell-based cancer vaccines to date have one feature in common, namely the intention to use cells that contain at least some TSAs and/or TAAs that are shared with the antigens present in patients' tumour. In each case, tumour cells are utilised as the starting point on the premise that only tumour cells will contain TSAs or TAAs of relevance, and the tissue origins of the cells are matched to the tumour site in patients. A primary aspect of the invention is the use of immortalised normal, non-malignant cells as the basis of an allogeneic cell cancer vaccine. Normal cells do not possess TSAs or relevant concentrations of TAAs and hence it is surprising that normal cells are effective as anti-cancer vaccines. For prostate cancer, for example, a vaccine may be based on one or a combination of different immortalised normal cell lines derived from the prostate. The cell lines are lethally irradiated utilising gamma irradiation at 50-300 Gy to ensure that they are replication incompetent prior to use in the mammal or human.
Example 1
Growth, Irradiation, Formulation and Storage of Cells
[0034] An immortalised cell line derived from normal prostate tissue namely PNT2 was grown in roller bottle culture in RPMI 1640 media supplemented with 2 mM L-glutamine and 5% foetal calf serum (FCS) following recovery from liquid nitrogen stocks. Following expansion in T175 static flasks the cells were seeded into roller bottles with a growth surface area of 850 cm 2 at 1−20×10 7 cells per roller bottle.
[0035] An immortalised cell line derived from primary prostate tissue namely NIH1542-CP3TX was grown in roller bottle culture in KSFM media supplemented with 25 ug/ml bovine pituitary extract, 5 ng/ml of epidermal growth factor, 2 nM L-glutamine, 10 nM HEPES buffer and 5% foetal calf serum (FCS) (hereinafter called “modified KSFM:) following recovery from liquid nitrogen stocks. Following expansion in T175 static flasks the cells were seeded into roller bottles with a growth surface area of 1,700 cm2 at 2−5×107 cells per roller bottle.
[0036] Two secondary derived cell lines were also used, namely LnCap and Du145 both of which were sourced from the ATCC. LnCap was grown in large surface area static flasks in RPMI media supplemented with 10% FCS and 2 mM L-glutamine following seeding at 1−10×10 6 cells per vessel and then grown to near confluence. Du-145 was expanded from frozen stocks in static flasks and then seeded into 850 cm 2 roller bottles at 1−20×10 7 cells per bottle and grown to confluence in DMEM medium containing 10% FCS and 2 mM L-glutamine. All cell lines were harvested utilising trypsin at 1× normal concentration. Following extensive washing in DMEM the cells were re-suspended at a concentration of 5−40×10 6 cells/ml and irradiated at 50-300 Gy using a Co 60 source. Following irradiation the cells were formulated in cryopreservation solution composing of 10% DMSO, 8% human serum albumin in phosphate buffered saline, and frozen at a cell concentration of 5−150×10 6 cells/ml, in liquid nitrogen until required for use.
Vaccination
[0037] Prostate cancer patients were selected on the basis of being refractory to hormone therapy with a serum PSA level of at least 30 ng/ml. Ethical permission and MCA (UK Medicines Control Agency) authorization were sought and obtained to conduct this trial.
[0038] One of three vaccination schedules was followed for each arm of the trial:
[0000]
Cell Lines Administered
Dose
Trial Arm A
Trial Arm B
Trial Arm C
1, 2 and 3
PNT2
Du145
LnCap
4 and
PNT2/Du145/
PNT/Du145/
PNT2/NIH1542/LnCap
subsequent
NIH1542
LnCap
[0039] The cells were warmed gently in a water bath at 37° C. and admixed with mycobacterial adjuvant prior to injection into patients. Injections were made intra-dermally at four injection sites into the draining lymph nodes. The minimum interval between doses was two weeks, and most of the doses were given at intervals of four weeks. Prior to the first dose, and prior to some subsequent doses, the patients were tested for delayed-type hypersensitivity (DTH) against the four cell lines listed in the vaccination schedule above (all tests involved 0.8×106 cells with no adjuvant).
Analysis of Immunological Response
(a) T-Cell Proliferation Responses
[0040] To determine if vaccination resulted in a specific expansion of T-cell populations that recognised antigens derived from the vaccinating cell lines we performed a proliferation assay on T-cells following stimulation with lysates of the prostate cell lines. Whole blood was extracted at each visit to the clinic and used in a BrdU (bromodeoxyuridine) based proliferation assay as described below:
Patent BrdU Proliferation Method
Reagents
[0041]
[0000]
RPMI
Life Technologies, Paisely Scotland.
BrdU
Sigma Chemical Co, Poole, Dorset.
PharMlyse
35221E
Pharminogen, Oxford UK
Cytofix/Cytoperm
2090KZ
″
Perm/Wash buffer (×10)
2091KZ
″
FITC Anti-BrdU/Dnase
340649
Becton Dickinson
PerCP Anti-CD3
347344
″
Pe Anti-CD4
30155X
Pharmingen
Pe Anti-CD8
30325X
″
FITC mu-IgG1
349041
Becton Dickinson
PerCP IgG1
349044
″
PE IgG1
340013
″
Method
[0000]
1) Dilute 1 ml blood with 9 ml RPMI+2 mM L-gin+PS+50 uM 2-Me. Do not add serum. Leave overnight at 37° C.
2) On following morning, aliquot 450 ul of diluted blood into wells of a 48-well plate and add 50 ul of stimulator lysate. The lysate is made by freeze-thawing tumour cells (2×106 cell equivalents/ml) ×3 in liquid nitrogen and then storing aliquots frozen until required.
3) Culture cells at 37° C. for 5 days.
4) On the evening of day 5 add 50 ul BrdU @30 ug/ml
5. Aliquot 100 ul of each sample into a 96-well round-bottomed plate.
6) Spin plate and discard supernatant
7) Lyse red cells using 100 ul Pharmlyse for 5 minutes at room temperature
8) Wash ×2 with 50 ul of Cytofix
9) Spin and remove supernatent by flicking
10) Permeabilise with 100 ul Perm wash for 10 mins at RT
11) Add 30 ul of antibody mix comprising antibodies at correct dilution made up to volume with Perm-wash
12) Incubate for 30 mins in the dark at room temperature.
13) Wash ×1 and resuspend in 100 ul 2% paraformaldehyde
14) Add this to 400 ul FACSFlow in cluster tubes ready for analysis
15) Analyse on FACScan, storing 3000 gated CD3 events.
6-Well Plate for Stimulation
[0057]
[0000]
Nil
ConA
1542
LnCap
Du145
Pnt2
PBL1
PBL2
PBL3
PBL4
PBL5
PBL6
96-Well Plate for Antibody Staining
[0058]
[0000]
PBL1
PBL2
PBL3
PBL4
PBL5
PBL6
Nil A
15D
Nil A
15 D
Nil A
15 D
Nil A
15 D
Nil A
15 D
Nil A
15 D
Nil D
15 E
Nil D
15 E
Nil D
15 E
Nil D
15 E
Nil D
15 E
Nil D
15 E
Nil E
Ln D
Nil E
Ln D
Nil E
Ln D
Nil E
Ln D
Nil E
Ln D
Nil E
Ln D
Con D
Ln E
Con D
Ln E
Con D
Ln E
Con D
Ln E
Con D
Ln E
Con D
Ln E
Con E
Du D
Con E
Du D
Con E
Du D
Con E
Du D
Con E
Du D
Con E
Du D
Du E
Du E
Du E
Du E
Du E
Du E
Ph D
Ph D
Ph D
Ph D
Ph D
Ph D
Ph E
Ph E
Ph E
Ph E
Ph E
Ph E
Legend:
[0000]
A: IgG1-FITC (5 ul) IgG1-PE (5 ul) IgG1-PerCP (5 ul) 15 ul MoAb+15 ul
D: BrdU-FITC (5 ul) CD4-PE (5 ul) CD3-PerCP (5 ul) 15 ul MoAb+15 ul
E: BrdU-FITC (5 ul) CD8-PE (5 ul) CD3-PerCP (5 ul) 15 ul MoAb+15 ul
15: NIH1542-CP3TX
Ln: LnCap
D: Du145
Pn: PNT2
Con: ConA lectin (positive control)
Nil: No stimulation
[0068] The results for the proliferation assays are shown in FIGS. 1A , 1 B and 1 C show where a proliferation index for either CD4 or CD8 positive T-cells are plotted against the various cell lysates. The proliferation index being derived by dividing through the percentage of T-cells proliferating by the no-lysate control.
[0069] Results are shown for patient numbers 112, 307 and 406. Results are given for four cell lysates namely, NIH1542, LnCap, DU-145 and PNT-2. Overall, 50% of patients treated mount a specific proliferative response to at least one of the cell lines.
(b) Western Blots Utilising Patients' Serum
[0070] Standardised cell lysates were prepared for a number of prostate cell lines to enable similar quantities of protein to be loaded on a denaturing SDS PAGE gel for Western blot analysis. Each blot was loaded with molecular weight markers, and equal amounts of protein derived from cell lysates of NIH1542, LnCap, DU-145 and PNT-2. The blot was then probed with serum from patients derived from pre-vaccination and following 16 weeks vaccination (four to six doses).
Method
a) Sample Preparation (Prostate Tumor Lines)
[0000]
Wash cell pellets 3 times in PBS
Re-suspend at 1×107 cells/ml of lysis buffer
Pass through 5 cycles of rapid freeze thaw lysis in liquid nitrogen/water bath
Centrifuge at 1500 rpm for 5 min to remove cell debris
Ultracentrifuge at 20,000 rpm for 30 min to remove membrane contaminants
Aliquot at 200 ul and stored at −80° C.
b) Gel Electrophoresis
[0000]
Lysates mixed 1:1 with Laemelli sample buffer and boiled for 5 min
20 ug samples loaded into 4-20% gradient gel wells
Gels run in Bjerrum and Schafer-Nielson transfer buffer (with SDS) at 200 V for 35 min.
c) Western Transfer
[0000]
Gels, nitrocellulose membranes and blotting paper equilibrated in transfer buffer for 15 min
Arrange gel-nitrocellulose sandwich on anode of semi-dry electrophoretic transfer cell: 2 sheets of blotting paper, nitrocellulose membrane, gel, 2 sheets of blotting paper
Apply cathode and run at 25 V for 90 min.
d) Immunological Detection of Proteins
[0000]
Block nitrocellulose membranes overnight at 4° C. with 5% Marvel in PBS/0/05% Tween 20
Rinse membranes twice in PBS/0.05% Tween 20, then wash for 20 min and 2×5 min at RT on a shaking platform
Incubate membranes in 1:20 dilution of clarified patient plasma for 120 min at RT on a shaking platform
Wash as above with an additional 5 min final wash
Incubate membranes in 1:250 dilution of biotin anti-human IgG or IgM for 90 min at RT on a shaking platform
Wash as above with an additional 5 min final wash
Incubate membranes in 1:1000 dilution of streptavidin-horseradish peroxidase conjugate for 60 min at RT on a shaking platform
Wash as above
Incubate membranes in Diaminobenzidine peroxidase substrate for 5 min to allow colour development, stop reaction by rinsing membrane with water
[0092] The results in FIGS. 3A , 3 B and 3 C show for patients 112, 305 and 402 clearly show that vaccination over the period of 16 weeks (four to six doses) can result in an increase in antibody titre against cell line lysates and also cross reactivity against lysates not received in this vaccination regime (other than DTH testing).
(c) Antibody Titre Determination
[0093] Antibody titres were determined by coating ELISA plates with standardised cell line lysates and performing dilution studies on serum from vaccinated patients.
[0000] Method for ELISA with Anti-Lysate IgG.
1. Coat plates with 50 ul/well lysates (@10 ug/ml) using the following dilutions:
[0000]
Lysate
Protein conc
Coating conc
Amount/ml
Amount in 5 mls ul
PNT2
2.5 mg/ml
10 ug/ml
3.89 ul
19.4 ul
1542
4.8 mg/ml
10 ug/ml
2.07 ul
10.3 ul
Du145
2.4 mg/ml
10 ug/ml
4.17 ul
20.8 ul
LnCap
2.4 mg/ml
10 ug/ml
4.12 ul
20.6 ul
2. Cover and incubate overnight @ 4° C.
3. Wash ×2 PBS-Tween. Pound plate on paper towels to dry.
4. Block with PBS/10% FCS (100 ul/well)
5. Cover and incubate @ room temperature (RT) for 1 hour (minimum).
6. Wash ×2 PBS-Tween
7. Add 100 ul PBS-10% FCS to rows 2-8
8. Add 200 ul plasma sample (diluted 1 in 100 in PBS-10% FCS ie. 10 ul plasma added to 999 uls PBS-10% FCS) to row 1 and do serial 100 ul dilutions down the plate as below. Discard extra 100 ul from bottom well. Cover and incubate in fridge overnight.
9. Dilute biotinylated antibody (Pharmingen; IgG 34162D) ie. Final conc 1 mg/ml (ie 20 ml in 10 mls).
10. Cover and incubate @RT for 45 min.
11. Wash ×6 as above.
12. Dilute streptavidin—HRP (Pharmingen, 13047E 0, dilute 1:1000 (ie 10 ml->10 mls).
13. Add 100 ml/well.
14. Incubate 30 min @RT.
15. Wash ×8.
16. Add 100 ml substrate/well. Allow to develop 10-80 min at RT.
17. Colour reaction stopped by adding 100 ml 1M H2SO4.
18. Read OD @ A405 nm.
[0112] The results in FIGS. 3A , 3 B and 3 C show for patients 112, 305 and 402 show antibody titres at baseline (0), 4 weeks, 8 weeks and 16 weeks. The data show that after vaccination with at least four doses, patients can show an increase in antibody titre against cell line lysates and also cross-reactivity against cell lines not received in this vaccination regime (except as DTH doses).
(d) Evaluation of PSA Levels
[0113] PSA levels for patients receiving the vaccine were recorded at entry into the trial and throughout the course of vaccination, using routinely used clinical kits. The PSA values for patients 110, 303 and 404 are shown in FIGS. 4A , 4 B and 4 C show (vertical axis is serum PSA in ng/ml; horizontal axis is time, with the first time point representing the initiation of the vaccination program) and portray a drop or partial stabilization of the PSA values, which in this group of patients normally continues to rise, often exponentially. The result for patient 110 is somewhat confounded by the radiotherapy treatment to alleviate bone pain, although the PSA level had dropped prior to radiotherapy.
Example 2
Use of a Normal Melanocyte in a Murine Melanoma Protection Model
[0114] A normal melanocyte cell line was used in a vaccination protection model of murine melanoma utilising the B16.F10 as the challenge dose. The C57 mice received two vaccinations of either PBS, 5×106 irradiated K1735 allogeneic melanoma cells or 5×106 irradiated Melan P1 autologous normal melanocyte cells on days −14 and −7. Challenge on day 0 was with 1×104 B16.F10 cells and tumour volume measured every three days from day 10 onwards. Animals were sacrificed when the tumour had grown to 1.5×1.5 cm measured across the maximum dimensions of the tumour. FIG. 5 shows that vaccination with Melan1P cells offer some level of protection against this particularly aggressive murine tumour.
[0115] This application claims priority to GB 9827104.2, filed Dec. 10, 1998, which is incorporated by reference in its entirety. | This invention is concerned with agents for the treatment of primary, metastatic and residual cancer in mammals (including humans) by inducing the immune system of the mammal or human afflicted with cancer to mount an attack against the tumour lesion. In particular, the invention pertains to the use of whole-cells, derivatives and portions thereof with or without vaccine adjuvants and/or other accessory factors. More particularly, this disclosure describes the use of particular combinations of whole-cells and derivatives and portions thereof that form the basis of treatment strategy. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
My copending application title "MECHANISM UTILIZING A SINGLE ROCKER ARM FOR CONTROLLING AN INTERNAL COMBUSTION ENGINE VALVE", Ser. No. 622,039 filed on June 2, 1984, now abandoned contains subject matter generally related to this application, said application, Ser. No. 622,039 filed on June 22, 1984 being a continuation-in-part of Ser. No. 491,819, filed May 5, 1983 (now U.S. Pat. No. 4,495,902, issued on Jan. 29, 1985) for "MECHANISM FOR VARIABLY CONTROLLING AN INTERNAL COMBUSTION ENGINE VALVE."
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to internal combustion engines, and pertains more particularly to a method and apparatus for controlling the operation of an internal combustion engine by means of valve throttling and charge stratification.
2. Description of tne Prior Art
A large number of patents have been obtained that involve stratification, the goal being to obtain improved combustion and better engine efficiency. Of course, better combustion results in a reduced amount of pollution.
U.S. Pat. No. 3,762,381, issued on Oct. 2, 1973 to Sharad M. Dave for "VARIABLE INTERNAL COMBUSTION ENGINE VALVE OPERATING SYSTEM" has dealt with efficiency and combustion problems. However, the patented system is relatively complex and involves movable components that are subjected to elevated temperatures.
Another patent that has been granted that involves stratification with the sought after better combustion, along with an improved control of exhaust gases, is U.S. Pat. No. 3,980,060, granted on Sept. 14, 1976 to Masaaki Noguchi et al for "INTERNAL COMBUSTION ENGINE." Here again, the stratification involves the utilization of movable parts that are vulnerable to possible malfunction and an accompanying loss of the results that are desired.
As already indicated, numerous patents have been issued in the general area involving stratification. Nonetheless, there still remains a need for achieving an optimized reduction of exhaust gas emissions and an overall improved internal combustion engine efficiency.
SUMMARY OF THE INVENTION
A general object of my invention is to provide an enhanced delivery of an air/fuel mixture into an internal combustion engine at relatively light loads. In this regard, an aim of the invention is to provide a method and apparatus for stratifying the mixture in a highly effective manner by employing intake valve throttling and at the same time utilizing stratification of the air/fuel mixture during idling and when the engine is under a relatively light load. In addition, the invention makes use of an arrangement whereby the stratified mixture is directed toward the combustion chamber's spark plug, effectively doing so during relatively small openings of the intake valve when the engine is operating under a light load condition so that the fuel delivery is highly atomized and concentrated in the region nearest the area where the ignition occurs during such a light load condition.
A more specific object of the invention is to improve the exhaust gas recirculation (EGR) in an internal combustion engine. In this regard, an aim of the invention is to provide for a variable rate of internal recirculation of exhaust gases in contradistinction to the widely employed external recirculation of exhaust gases currently resorted to.
In the furtherance of the above objects, it is within the contemplation of my invention to entrap some of the exhaust gases by closing the exhaust valve prior to top dead center of the piston during idling and under light engine loads so that a significant percentage of the hydrocarbons remaining in the trapped exhaust gases will be internally recirculated so as to be burned with the incoming stratified air/fuel charge, this being exceedingly important in achieving a more complete combustion under light engine load conditions. Stated even more specifically, it is within the purview of the invention to recompress some of the exhaust gases retained in the combustion chamber toward the end of the piston's exhaust stroke so that the gases are maintained at a desirably elevated temperature during throttled operating conditions.
Still another object of the invention is to delay the introduction of the air/fuel mixture into the combustion engine during the usual intake stroke and even postponing the introduction of the air/fuel mixture until a period during the first half of the compression stroke. This has the desirable effect of reducing the time interval between the actual induction of the highly atomized charge and the ignition thereof at a light operating condition.
One stratification method in the past has involved a swirl process that has worked quite well under moderate engine load conditions but under heavier load conditions, especially at wide open throttle, the stratification process usually interferes with the volumetric efficiency of the engine. An aim of my invention is to provide a system in which the stratification and accompanying atomization are extremely beneficial and effective at light loads or idle conditions and in which the volumetric efficiency is considerably increased under heavier or wide open throttle conditions attributable to the high performance events obtainable with a variable valve controlling mechanism.
Still another object is to provide a method and apparatus for controlling the operation of an internal combustion engine in which cold weather starting is vastly improved.
An overall goal of my invention is, thus, to provide simple apparatus for obtaining an effective internal recirculation of exhaust gases, a recirculation devoid of any additional moving parts over and above those normally employed in the controlling of conventional valve actuating mechanisms.
Briefly, my invention involves the utilization of intake valve throttling, together with an effective stratification of the charge during a comparatively small opening or lift of the intake valve of an internal combustion engine. In this regard, it is intended that a single rocker arm be utilized and that the valve be only partially opened under idle or light load conditions in contradistinction to the usual engine in which the valve is opened fully irrespective of the engine's load.
It is also planned that the stratified and highly atomized air/fuel mixture resulting from the limited opening of the intake valve be directed generally toward the spark plug. This is realized by employing a generally cylindrical shroud that extends into the combustion engine to an extent sufficient to produce a desired amount of stratification for a lesser initial opening of the valve. While the shroud is generally cylindrical, a portion of the cylinder head forming the shroud is relieved or grooved to form a gap adjacent the side of the valve seat closest to the spark plug. After the valve has opened farther, that is, past the shroud, then the air/fuel mixture is allowed to disperse into the combustion chamber throughout virtually a complete circle. During the initial opening of the valve only an arc of approximately 20° is subtended, the precise angle depending on the arcuate gap in the generally cylindrical shroud. Additionally, it is envisaged that the opening of the intake valve be delayed to a later point during the intake stroke, or even postponed from the intake or suction stroke in which it is normally opened to some point in the first half of the combustion stroke. The goal is to reduce appreciably the interval of time between the moment at which atomization takes place and the ignition of the atomized charge. It is also intended that the exhaust valve associated with the combustion chamber be opened during a certain portion of the exhaust stroke and closed during other portions, especially during the portion as the piston nears top dead center, so that the exhaust end gases are trapped and the combustibles remaining therein effectively burned when the incoming stratified charge is ignited.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of apparatus for opening and closing an intake and an exhaust valve of an internal combustion engine;
FIG. 2 is a vertical sectional view taken in the direction of line 2--2 of FIG. 1 in order to illustrate apparatus for controlling the opening and closing of the intake valve of FIG. 1, the view depicting the intake valve in its closed or seated relation;
FIG. 3 is a vertical sectional view corresponding to FIG. 2 but with the intake valve partially open so as to stratify the air/fuel mixture being introduced into the combustion chamber;
FIG. 4 is an enlarged sectional view taken in the direction of line 4--4 of FIG. 1 for the purpose of showing the intake valve, the generally cylindrical shroud and the gap or groove therein for directing the air/fuel mixture toward the spark plug, the valve being closed;
FIG. 5 is a view similar to FIG. 4 but depicting the valve in a partially open condition corresponding to the amount of valve lift shown in FIG. 3, such condition directing the stratified charge toward the spark plug;
FIG. 6 is a plan view looking up in the direction of line 6l13 6 of FIG. 2, the view showing the physical relation between the intake valve, the exhaust valve and the spark plug;
FIGS. 7A, 7B, 7C and 7D are schematic or diagrammatic views depicting a pattern of opening and closing the intake and exhaust valves in relation to piston movement;
FIG. 8 constitutes a graph with valve lift or valve opening plotted against crankshaft rotation, the solid curves depicting the opening and closing, respectively, of the intake and exhaust valves when utilizing the mechanism of FIGS. 1-3, and the dotted curves depicting the opening and closing of conventional intake and exhaust valves, and
FIG. 9 is a graph showing a phasing relationship in which the opening of the exhaust valve is advanced so as to occur during the normally designated power stroke.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, a conventional internal combustion engine 10 has been fragmentarily illustrated. The engine 10 includes an engine block 12 containing a number of combustion cylinders or chambers 14 therein, only the upper portion of one such chamber 14 appearing in FIGS. 2 and 3. Reciprocably disposed within the combustion chamber 14 is a piston 16. Being conventional, it is not thought necessary to illustrate the piston rod or the crankshaft. Overlying the cylinder block 12, however, and secured thereto is a cylinder head 18.
Included in the engine block 12 is a valve port 20 formed in the lower side of the cylinder head 18 by reason of a downwardly facing beveled seat 22. The valve port 20 constitutes an intake opening, a passage 24 extending to the opening or port 20 from the intake manifold (not shown) of the engine 10.
There is a reciprocable intake valve 26 having a valve head 28 at its lower end, the valve head 28 being beveled at 30 so as to seat against the beveled seat 22. The valve 26 additionally includes a valve stem 32 extending upwardly from the head 28.
A coil spring 34 encircles the upper portion of the valve stem 32, the lower end of this spring 34 bearing against the cylinder head 18. Located at the upper end of the stem 32 is a spring retainer denoted generally by the reference numeral 36 which retainer 36 is more fully described in my said copending application, Ser. No. 622,039 filed on June 22, 1984.
The engine 10 additionally includes a camshaft 38 journaled for rotation in two bearing blocks 40. The bearing blocks 40 are mounted on an overlying base plate 42 by means of bolts 44, the base plate 42 being attached to the head 18 by means of additional bolts 46. The camshaft 38, it will be understood, is driven by the crankshaft (not illustrated) of the engine 10. The camshaft 38 is driven at half the rotative speed of the undisclosed crankshaft.
Each cylinder or combustion chamber 14 also has an exhaust valve 48 associated therewith, the exhaust valve 48 48 associated therewith, the exhaust valve 48 being visible in FIG. 6.
The valve throttling control mechanism for actuating the intake valve 26 has been denoted generally by the reference numeral 50. Included in the mechanism 50 is a cam unit or cam assembly indicated generally by the reference numeral 52 and which is more fully described in my said copending application, Ser. No. 622,039 filed on June 22, 1984. It will, however, be well at this time to mention several of the cam components belonging to the unit 52. In this regard, the cam unit 52 includes a central or main cam 54 and a pair of flanking cams 56, only one such flanking cam 56 appearing in FIGS. 2 and 3.
The mechanism 50 further includes an L-shaped rocker arm 58 having a substantially vertical leg 60 and a substantially horizontal leg 62. The rocker arm 58 is mounted for pivotal rocking movement on a pin 64.
Referring in greater detail to the vertical leg 60 of the rocker arm 58, it is to be explained that the vertical leg 60 has a cam follower surface denoted generally by the reference numeral 66. The cam follower surface 66 appears only in phantom outline, but is more fully described in my said copending application. All that need be appreciated at this time is that the central cam 54 acts against the portion labeled 68 of the cam follower surface 66 to rock the rocker arm 58. Inasmuch as there are two flanking cams 56, there are two flanking portions 70 of the cam follower surface 66, one at each side of the follower surface portion 68.
Regarding the horizontal leg 62 of the rocker arm 58, it is considerably simpler in shape than the vertical leg 60. The horizontal leg 62 is actually curved or arched to provide clearance with respect to a shaft 72. Although an adjusting device indicated generally by the reference numeral 74 acts against the upper end of the valve stem 32, it is not essential that the device 74 be fully described herein, especially since it is more completely referred to in my copending application. It can be pointed out in passing, though, that the device 74 enables the lash to be adjusted.
At this time, attention is directed to the presence of a lever arm 76, the lever arm 76 supporting the rocker arm 58 by means of the pin 64 for rocking movement so that the device 74 on the free end of the horizontal leg 62 acts against the upper end of the valve stem 32 to open the valve 26 when the rocker arm 58 is rocked in a clockwise direction as viewed in FIGS. 2 and 3. It should be noted, though, that when the lever arm 76 is actuated in a counterclockwise direction, also as viewed in FIGS. 2 and 3, the vertical leg 60 of the rocker arm 58 is moved downwardly so as to present various sections of the portions 68, 70 constituting the cam follower surface 66 to the cams 54, 56 of the cam unit 52.
Although other devices can be employed, a device indicated generally by the reference numeral 78 is employed for positioning the lever arm 76, and in turn to position the vertical leg 60 of the rocker arm 58, to produce an optimum relation with the cam unit 52 so that the cam unit 52 acts on the most appropriate portion of the cam follower surface 66 for the particular load to which the engine 10 is subjected. As the description progresses, it will become manifest that the present invention is primarily concerned with only a partial opening or restricted lift of the intake valve 26. The device 78 illustratively includes an eyebolt 80 threaded upwardly into the left end of the lever arm 76, as viewed in FIG. 2. A vertical rod 82 extends downwardly from the eyebolt 80, the rod 82 having a hook 84 at its upper end that engages the eye of the eyebolt 80. A hydraulic amplifier or servomechanism 86, through a link 88, augments the foot force applied to an accelerator pedal 90. The accelerator pedal 90 is pivotally mounted at 92 to the floorboard 94 of the vehicle having the engine 10 therein, a spring 96 biasing the pedal 90 upwardly and away from the floorboard 94. What should be recognized, however, is that the device 78 controls the opening and closing of the valve 26 in accordance with the load to which the engine 10 is to be subjected at any given moment. A more elaborate and complex servomechanism might very well be utilized in actual practice, one automatically responding to, say, engine speed. Nonetheless, in order to illustrate the invention, the simplified device 78 is believed adequate.
The mechanism 50, it is to be understood, constitutes an intake valve throttling device. Hence, the valve 26 by reason of the control mechanism 50 opens the valve 26 to obtain a lift or valve opening that is commensurate with the load imposed on the engine 10. Stated somewhat differently, when the engine 10 is being throttled or under only a light load, then the valve 26 is opened only slightly--not fully as is customary.
In order to obtain the desired stratification of the air/fuel mixture being introduced into the combustion chamber 14 of the engine 10, a generally cylindrical shroud 98 is employed, the shroud 98 extending vertically downwardly from the lower edge of the beveled valve seat 22. The vertical length of the shroud 98 is subject to some variation. As the description progresses, it will become more apparent that the length should not exceed 25 percent of the full lift or opening of the valve 26, a 20 percent limitation being desirable in a number of instances. In other words, for a 0.500 inch lift, the shroud 98 should preferably extend downwardly from the lower edge of the seat 22 a distance not more than 0.125 inch. For a 0.400 inch lift, the maximum distance should, as a practical matter, be 0.100 inch.
From FIGS. 2 and 3, it will be observed that the shroud 98 constitutes a cylindrical wall or bore. However, the shroud 98 is only generally cylindrical, for a gap is formed at 100 which appears in FIGS. 4-6. The gap 100 forms what might be termed an entrance for a groove 102 extending radially toward ignition means in the form of a spark plug 104, the exit end of the groove 102 adjacent the spark plug 104 being labeled 106. The groove 102 is tapered, as can be perceived from FIG. 6, becoming narrower in the direction from the gap or entrance 100 to the exit or discharge end 106. The groove 102 subtends an arc or angle of approximately 30° at its wide end, that is, at the gap 100, and approximately 15° at its narrow end, that is at its exit 106. Thus, during the early or initial opening of the valve 26, the only real route that the incoming air/fuel mixture can travel is in the direction of the spark plug 104.
Whereas FIGS. 2 and 4 show the valve 26 closed, FIGS. 3 and 5 depict the valve partially open so that the incoming air/fuel charge is constrained to flow toward the spark plug 104 and not in a general direction or throughout 360°. More specifically, the air/fuel mixture is constrained to flow through an angle subtending approximating 20°. However, after the valve head 28 moves downwardly beyond the lower edge of the generally cylindrical shroud 98, then the incoming air/fuel charge is dispersed throughout virtually an entire 360° or complete circle. In other words, it is only during the initial and limited opening of the valve 26 that stratification occurs, and it is during this period that the stratified charge is directed toward the spark plug 104. It is not believed necessary to show an opening of the valve 26 beyond that depicted in FIGS. 3 and 5. Unlike prior art control mechanisms, though, the use of intake valve throttling, as derived from the mechanism 50, limits the movement or opening of the valve 26 during an idling or light load condition imposed upon the engine 10, which is important when practicing my invention, for if the valve lift or opening always reached its maximum, previously mentioned as being on the order of from 0.400 to 0.500 inch, the stratification interval would be followed by an extensive non-stratification period each time the valve 26 opened. With the mechanism 50, though, if there is a throttling or light load condition, the valve 26 does not move downwardly past the lower edge of the shroud 98. The restricted movement greatly increases the atomization efficiency at light loads.
An exhaust valve 126 appears in FIG. 6 and is denoted in phantom outline in FIG. 1. It is opened and closed by a valve operating mechanism 150 that is basically the same as the mechanism 50 for the intake valve 26. Therefore, the corresponding parts carry the same reference numerals. What is not necessarily the same is the profile of the cam unit 52 (not visible) which contains cams profiled differently from the cams 54 and 56. Likewise, the cam follower surface 66 (also not visible) is not the same. Obviously, the phasing between the intake valve 26 opening and closing must be different from the opening and closing of the exhaust valve 126.
For the sake of simplification, the two valve controlling mechanisms 50 and 150 are mechanically connected by a tie bar or strip 108, the tie bar 108 being attached at one end to the lever arm 76 of the mechanism 50 by bolts 110 and attached at its other end to the lever arm 76 of the mechanism 150 by bolts 112. Thus, the mechanisms 50, 150 are operated in concert by the device 78. However, separate devices 78 could be utilized, and also separate camshafts 38. For example, the use of two camshafts can be used in order to derive the results graphically pictured in FIG. 9.
With the appreciation in mind that various valve control patterns can be realized by modifying the cam and surface profiles, attention is now directed to FIGS. 7A, 7B, 7C and 7D which need only be diagrammatically presented. What transpires, as well as what can be achieved, will become even clearer when considering FIGS. 8 and 9. In FIG. 7A, the piston 16 is moving upwardly in the direction of the arrow 114, this being during the exhaust stroke. Both the intake valve 26 and the exhaust valve 126 are closed, however, at the depicted moment, which is as the piston 16 is approaching top dead center (TDC), having traveled upwardly an appreciable distance from bottom dead center (BDC). During the earlier portion of the exhaust stroke, the exhaust valve 126 was opened to rid the combustion of some of the exhaust gases. However, because my invention provides internal--exhaust gas recirculation, it is necessary to trap some of the end gases, which contain a higher concentration of combustible hydrocarbons therein. It should be borne in mind that the bulk of the hydrocarbon emissions are typically discharged during the last 10 percent of the exhaust stroke. From the ensuing description, it will become evident that my invention enables the combustibles to be effectively burned internally, thereby obviating the need for externally recirculating such gases as is now done.
Turning now to FIG. 7B, the piston 16 is at this time traveling downwardly in the direction of the arrow 116 during an intake stroke. Consequently, the intake valve 26 is open, but only partially so. In this regard, it will be assumed that the engine 10 is under a light load. Hence, the control mechanism 50, as can be even better understood from FIGS. 3 and 5, has opened the valve 26 to only a limited degree--more precisely only to the extent that the lower edge of the beveled surface 30 is even with the lower edge of the shroud 98. This restricted valve opening exists in FIG. 7B. Thus, the valve 26 in FIG. 7B is opened only enough to allow a sufficient charge of air and fuel to flow via the groove 102 of FIGS. 4, 5 and 6 for the light load to which the engine 10 is subjected. The exhaust valve 126 is, of course, closed.
FIG. 7C depicts the stratified air/fuel mixture that has been inducted into the combustion chamber 14 in FIG. 7B to be compressed, the piston 16 moving upwardly in the direction of the arrow 118 to effect this compression. More specifically, FIG. 7C shows the ignition that takes place by reason of the spark plug 104 being energized at the end of the compression stroke. Both valves 26 and 126 are closed.
It is FIG. 7D that illustrates the power stroke, the piston 16 moving downwardly in the direction of the arrow 120. Both valves 26 and 126 are closed.
In summary, FIGS. 7A-7D demonstrate that when practicing the teachings of my invention a desired percentage of the exhaust gases can be trapped in the combustion chamber 14 (FIG. 7A) and mixed with the incoming stratified charge (FIG. 7B), thereby reducing pollution in that the combustibles retained in the chamber 14 are mixed with the incoming air/fuel and to a significant extent burned when the plug or ignition means 104 produces a spark.
The flexibility and versatility derivable from my invention can also be appreciated by considering FIG. 8 in which valve lift is plotted against crankshaft degrees. The curve representative of the opening and closing of the exhaust valve 126 has been assigned the reference numeral 122 and the curve representative of the opening and closing of the inlet valve 26 by the numeral 124. It should be observed from the curve 122 that the exhaust valve begins to open at about -185° and that it closes at about -60°, the point at which the piston 16 appears in FIG. 7A. It is, of course, the -60° closing point that entraps a percentage of the exhaust gases as explained when considering FIG. 7A.
The intake valve 26, as deduced from the curve 124, opens at approximately +70°, closing at approximately 160°. The +70° point corresponds generally to the physical relationship of the valve 26 and the piston 16 in FIG. 7B. Since the 0° point in FIG. 8 constitutes a top dead center (TDC) position of the piston 16, the delayed opening of the valve 26 (well into the intake stroke) is illustrated. This reduces the interval between the introduction of the stratified charge for an idle condition of the engine 10 and the moment of which a spark is furnished by the spark plug 104. The additional curve 125, composed of dashes, graphically illustrates even a greater postponement, as far as the opening of the inlet valve 26. The opening at about +185° and the closing at about +270°, as denoted by the curve 125, is during the first half of the compression stroke, it might be pointed out.
Without detailing the degrees at which the opening and closing of typical conventional or stock exhaust and intake valves, respectively, are concerned, it might be well to superimpose onto FIG. 8 dotted curves 138 and 140. Obviously, the exhaust curve 138 and the intake curve 140 represent situations involving no valve throttling, the particular exhaust and intake valves opening completely during each exhaust and each intake stroke
It is easy to obtain a so-called Jake brake operation with my invention. The term "Jake brake" is synonomous with "engine brake" which refers to a change in valve timing which converts the engine into an inefficient air compressor during deceleration. In other words, as far as a Jake brake operation is concerned, a phase change of the camshaft relative to the crankshaft is effected so that the exhaust event occurs generally during the normally designated power stroke. This is done with the intake valve 26 rendered inoperable, so that it remains closed, or at least substantially closed. Therefore, the dotted curve 142 in FIG. 9 depicts the usual or stock event, as far as the opening and closing of the exhaust valve 126, whereas the solid curve 144 shows the shifted or advanced opening and closing of the valve 126. The stock exhaust opening and closing, as denoted by the curve 142, takes place between approximately -210° and +60°, and the corresponding Jake brake opening and closing takes place between approximately +240° and -160°.
The result, as far as the Jake brake mode of operation is concerned, is that whatever exhaust gases that have been earlier forced from the combustion chamber 14 into the exhaust passage leading to the exhaust manifold (neither the intake nor exhaust manifolds have been shown) is pulled back into the chamber 14 by the subatmospheric pressure created by the downwardly moving piston 16. At this time, the exhaust valve 126 is closed and the exhaust gases are compressed and subsequently released near top dead center of the compression stroke. The operation of the so-called Jake brake with respect to exhaust gases is considered to be advantageous since the noise associated with the pressure release is absorbed in the engine's exhaust system. | Intake valve throttling is employed to limit the lift or opening of an intake valve to a relatively small opening during light engine loads. A generally cylindrical shroud projects into the combustion chamber, the shroud having a gap facing in the direction of the spark plug, so that a desired amount of stratification of the incoming charge is achieved during light engine loads. Opening and closing of the exhaust valve are correlated with the actuation of the intake valve in order to obtain certain results, including better combustion with a concomitant decrease in the amount of pollution. | 5 |
REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of application Ser. No. 10/313,273 filed Dec. 6, 2002 and incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of articles worn by persons to reduce the likelihood, severity, or exacerbation of injury to the body, and more specifically to the field of braces worn on the ankle.
BACKGROUND OF THE INVENTION
[0003] The ankle joint is one of the most frequently used joints in the body, as it is required for any activity that involves walking or running. The ankle joint connects the lower leg and the foot of a person, providing a pivot point that allows the foot to rotate relative to the lower leg. Together the lower leg, ankle joint, and foot make up a complex system that must be sturdy yet flexible in order to bear a person's weight while providing freedom of movement.
[0004] During ambulation, and especially during strenuous sports such as football, basketball, tennis, or soccer, quick changes in direction or uneven playing surfaces can cause the ankle to move beyond its normal range of motion, resulting in a sprained ankle. A sprained ankle may be painful, and can make sports less enjoyable, reduce athletic performance, and adversely affect day to day activities. Further, once an ankle joint has been injured, the injury is more likely to recur. For these reasons, there has long been motivation to find ways to protect the ankle without restricting freedom of motion, to prevent injuries and to protect the ankle during recovery from a previous injury.
[0005] The ankle joint itself is comprised of a bone structure held together by ligaments. The bone structure of the ankle consists of seven tarsal bones, including the talus, calcaneus (heel bone), and navicular bones. The talus is the bone which lies adjacent to the lower ends of the tibia and fibula (the two lower leg bones).
[0006] A single triangular shaped ligament, the deltoid ligament, holds together the medial (inside) portion of the ankle joint, joining the tibia, talus, calcaneus, and navicular bones. Because of its size, the deltoid ligament is strong and relatively resistant to sprain injuries.
[0007] Four major ligaments, named for the bones they join together and their relative positions, hold together the lateral (outside) portion of the ankle joint. The anterior inferior tibiofibular ligament, located at the top of the ankle joint, joins the tibia and fibula. The anterior and posterior talofibular ligaments, located at the front and rear of the ankle joint respectively, join the talus and the fibula. The calcaneofibular ligament, located at the rear of the ankle joint, joins the calcaneus to the fibula. Most ankle sprains involve these ligaments on the lateral portion of the ankle joint.
[0008] The ligaments and bone structure which comprise the ankle joint determine the four basic ways that the foot can move relative to the lower leg. Dorsiflexion is when the toes are drawn toward the tibia (shin), as would occur when leaning forward. Plantar flexion is when the toes are pointed away from the tibia, as would occur when standing on tiptoes. Inversion is when the foot turns inwards, and eversion is when the foot rotates outwards.
[0009] Sprains may occur in any ligament in the ankle, but most sprains involve two particular ligaments on the outside of the ankle, the anterior talofibular ligament, and to a lesser extent, the calcaneofibular ligament. When an ankle sprain occurs, the anterior talofibular ligament is usually the first to be injured, followed by injury to the calcaneofibular ligament. For this reason, a sprained ankle usually involves injury to the anterior talofibular ligament or to both the anterior talofibular and the calcaneofibular ligaments, but a sprained ankle usually does not involve injury to the calcaneofibular ligament alone.
[0010] Many ankle sprains are the result of inversion, where the foot is rotated inward, which stretches the anterior talofibular ligament beyond its elastic limit. Injury to the anterior talofibular ligament is especially likely when the foot is plantar flexed and then undergoes forcible inversion. When the foot is at maximum plantar flexion, when the toes are pointed downward as far as possible, the anterior talofibular ligament is pulled taut. When the anterior talofibular ligament is taut, that ligament cannot stretch any further and any subsequent forcible inversion may cause that ligament to be strained, or partially or completely torn. Such forcible inversion might occur, for example, when an athlete jumps in the air and then lands on their own inverted foot or on an uneven surface, such as a hole, another player, or some other obstacle.
[0011] Ankle braces have been used for many years, in a variety of specific embodiments directed to particular applications, including protection of the anterior talofibular ligament. However, prior ankle braces designed to protect the anterior talofibular ligament have been made to fit either the right foot or the left foot, but not both. Thus, an ankle brace designed to protect the anterior talofibular ligament which could be worn on either the left or right foot would be desirable, to simplify inventory management and reduce costs.
SUMMARY OF THE INVENTION
[0012] The present invention features an ankle brace comprising a base of flexible material shaped to wrap around the sides of a foot and ankle and underneath a portion of the foot, with a support strap for protecting the anterior talofibular ligament. The two ends of the support strap are fixed to the base at or near the forward edges of the base, and the support strap is not otherwise fixed to the base.
[0013] An ankle brace according to the invention features a symmetric construction such that the ankle brace may be worn on either the left or the right foot. This feature reduces the number of different products which must be manufactured and maintained in inventory, compared to other ankle braces which can be worn on only the left or the right foot.
[0014] An ankle brace according to the present invention features an anterior talofibular ligament support strap which is not secured to the base of the brace beneath the foot. This feature allows the strap to move freely under the foot, so that the support strap can conform to the particular size and shape of the foot of a particular wearer. This feature provides a better fit to a particular wearer, compared to other ankle braces which include an anterior talofibular ligament support strap which is secured to the base of the brace beneath the sole of the foot.
[0015] Further objects, features, and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In the drawings:
[0017] FIG. 1 is a side view of an ankle brace according to the invention installed on a foot;
[0018] FIG. 2 is a rear view of an ankle brace according to the invention installed on a foot;
[0019] FIG. 3 is a front view of an ankle brace according to the invention laid out flat, with the tongue and laces removed to show the internal construction;
[0020] FIG. 4 is a rear view of an ankle brace according to the invention laid out flat, with the tongue and laces removed to show the internal construction.
[0021] FIG. 5 is a front view of an ankle brace according to the invention, with the tongue and laces removed to show the internal construction;
[0022] FIG. 6 is a cross-sectional view of the ankle brace of FIG. 3 taken along the line 6 - 6 thereof;
[0023] FIG. 7 is a cross-sectional view of the ankle brace of FIG. 3 taken along the line 7 - 7 thereof; and
[0024] FIG. 8 is a side view of a resilient stay member made of flattened springs.
DETAILED DESCRIPTION OF THE INVENTION
[0025] With reference to the drawings, FIG. 1 is a side view of a preferred embodiment of an ankle brace in accordance with the invention, indicated generally at 10 in FIG. 1 . The foot has a toe region 11 that extends out from an opening in the front of the ankle brace 10 , and a heel region 12 that extends out from a opening in the rear of the ankle brace. The lower leg 13 of the person extends out from an opening at the top of the ankle brace. The brace 10 generally surrounds the ankle 14 of the person.
[0026] The ankle brace 10 is comprised of a base, indicated generally at 15 , and a tongue 16 , which are shaped generally to wrap about the foot and ankle of a person. The base 15 of the ankle brace 10 may be fastened about the foot using a plurality of eyelets 17 and a shoelace 18 tied in a knot 19 . Although eyelets 17 and shoelace 18 are used in the preferred embodiment, other means such as straps or hook and loop material of the type that adheres when pressed together may be used.
[0027] As best shown in FIG. 2 , the base 15 of the ankle brace 10 has a first side 20 and a second side 21 . The first side 20 of the base 15 has a rear edge 22 , and this rear edge 22 has an upper portion 24 and a middle portion 26 . The second side 21 of the base has a rear edge 23 , and this rear edge 23 has an upper portion 25 and a middle portion 27 .
[0028] As best shown in FIG. 4 , the first side 20 of the base 15 has a forward edge 28 , and the second side 21 of the base 15 has a forward edge 29 . Eyelets 17 may be arranged along these forward edges. The shoelace 18 may be passed through the eyelets 17 , placed under tension, and tied into a knot 27 , in order to draw the first side forward edge 28 and the second side forward edge 29 together. The spacing of the eyelets 17 may be varied so that the tension of the ankle brace is greatest in the vicinity of the ankle, although this is not required.
[0029] As best shown in FIGS. 2 and 3 , the ankle brace preferably has an upper rear panel 32 having a first end 33 and a second end 34 . The first end 33 and the second end 34 of the upper rear panel 32 are attached, for example using stitching 38 , to the upper portions 24 and 25 , respectively, of the rear edges of the first and second sides of the base. The upper rear panel 32 is preferably formed of elastic sheet material which stretches in both horizontal and vertical directions, although this is not required.
[0030] As best shown in FIGS. 2 and 3 , the ankle brace preferably has a middle rear panel 35 having a first end 36 and a second end 37 . The first end 36 and the second end 37 of the middle rear panel 35 are attached, for example using stitching 38 , to the middle portions 26 and 27 , respectively, of the rear edges of the first and second sides of the base. The middle rear panel 35 is preferably formed of directionally elastic sheet material which stretches in the horizontal direction but is relatively inelastic in the vertical direction, although this is not required. The upper rear panel 32 and the middle rear panel 35 may be secured to each other, for example using stitching 38 , although this is not required.
[0031] As perhaps best shown in FIGS. 3 and 4 , the first side 20 and the second side 21 of the base 15 are generally symmetric, such that the ankle brace 10 can be worn on either the left or right foot. Edge binding 40 may be secured, preferably using stitching 41 , to cover the edges of the base 17 and the tongue 18 , although this is not necessary.
[0032] Although the first side 25 and second side 26 of the base 17 may be formed of a single layer of sheet material, they are preferably formed of multiple layers of sheet materials which are secured together, for example using stitches 41 , although this is not required. As illustrated in FIGS. 6 and 7 , an inside layer 42 and an outside layer 44 may be provided. The inside layer 42 may be chosen to have a soft surface since it may be in contact with the skin of the wearer. The outer layer material 44 may be chosen to be resistant to tearing, stains, and moisture, since it forms the outside surface of the ankle brace. Some portions of the base of the brace may also include a center layer (not shown) which may be chosen to be relatively rigid to provide structural integrity to those portions of the base of the ankle brace, although this is not required.
[0033] Although the base 15 may be made as a single piece, in a preferred embodiment the first side 20 and the second side 21 of the base 15 are made as separate pieces. In a preferred embodiment, an outside bottom edge attachment member 45 and an inside bottom edge attachment member 46 (shown in FIGS. 7 and 8 ) are provided to join the first side 20 and the second side 21 of the base 15 , preferably using stitching 47 .
[0034] One or more resilient support means 50 may be provided on each side of the base of the brace, although this is not required. As best shown in FIG. 4 , the resilient support means 50 are preferably comprised of a resilient stay member 51 located in an elongate pocket 52 formed between the outside layer 44 and the inside layer 42 of the base 15 , preferably by stitching 53 . Alternatively, if a center layer is provided, the elongate pocket 52 may be formed between the outside layer 44 and the center layer, or between the inside layer 42 and the center layer. The resilient stay member 51 may be formed of a pair of interleaved helical springs made of stainless steel that have been flattened, as shown in FIG. 8 , or other flexible material of conventional construction commonly used in various types of braces.
[0035] In a preferred embodiment, two elongate pockets 52 , each containing a resilient stay member 51 , are located on each side of the brace, for a total of four resilient support means 50 . As best shown in FIG. 1 , a preferred embodiment includes one resilient support means 50 located behind the ankle, approximately vertical in orientation and roughly parallel to the rear edge of the base, and a second resilient support means 50 located forward of the ankle, running approximately vertically from a point above the ankle and then curving below the ankle.
[0036] FIGS. 3-7 best illustrate the construction of the sole portion 60 of the base of a preferred embodiment of an ankle brace according to the invention. As best shown in FIG. 4 , the sole portion 60 corresponds generally to the area of the base bounded by forward edge 61 , rear edge 62 , and stitches 65 on each side of the base. The sole portion 60 has an inside surface 63 and an outside surface 64 .
[0037] As best shown in FIGS. 3 and 5 , an ankle brace according to the invention includes a support strap 70 having a first end 71 and a second end 72 . The first end 71 of the support strap 70 may be attached near the forward edge 28 of the first side 20 of the base 15 , and the second end 72 of the support strap 70 may be attached near the forward edge 29 of the second side 21 of the base 15 , preferably using stitches 76 . In addition to or instead of stitches 76 , the first end 71 of the support strap 70 may also be attached to the forward edge 28 of the first side 20 of the base 15 , and the second end 72 of the support strap 70 may also be attached to the forward edge 29 of the second side 21 of the base 15 using stitches 41 which are used to secure the edge binding 40 to the edges of the base, although this is not required. In a preferred embodiment, the support strap 70 is unconnected to the base 15 at any point within the sole portion 60 of the base 15 .
[0038] As best shown in FIGS. 3, 5 , 6 and 7 , an elongate sole strap 73 , having a first end 74 and a second end 75 , may be provided, although this is not required. The elongate sole strap 73 may be made of any sheet material having an appropriate strength and texture. The first end 74 of the elongate sole strap 73 may be attached to the forward edge 61 of the sole portion 60 of the base 15 , and the second end 75 of the elongate sole strap 73 may be attached to the rear edge 62 of the sole portion 60 of the base 15 , preferably using stitches 47 . The elongate sole strap 73 is preferably otherwise unconnected to the base 15 .
[0039] Thus it can be seen that the present invention provides an ankle brace which can be worn on either the left or right foot, and which is self-adjusting to fit the particular size and shape of the foot of the wearer. While the foregoing description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one or more preferred embodiments thereof. Many other variations are possible.
[0040] For example, although a preferred embodiment of an ankle brace according to the invention includes a support strap with ends secured along a line near the forward edges of the sides of the base 15 using stitches 76 , the ends of the support strap may be attached to other points at or near the forward edges of the sides of the base. Instead of using stitches, other means could be used to secure the ends of the support strap, such as glue, thermal bonding, or other means known in the art.
[0041] Instead of permanently securing the ends of the support strap, detachable attachment means such as hook and loop material of the type which adheres when pressed together could be provided on the support strap and along the inside of the base, to allow the support strap to be detachably attached to the base. Instead of or in addition to hook and loop material, the ends of the support strap could be provided with holes at a plurality of points near the ends of the support strap, and the shoelace 18 could be passed through a selected set of those holes in the support strap and through the eyelets 17 .
[0042] There may be more than one elongated side pocket 72 containing a resilient stay member 74 on each side, and the elongated side pocket 72 may be openable at one end to allow removal of the resilient stay member or replacement of the resilient stay member with a different resilient stay member having different resiliency to adjust the amount of support provided.
[0043] Although shoelace and eyelets are used in a preferred embodiment to fasten the ankle brace around the foot and ankle this could be done in other ways. Straps bearing hook and loop material of the type that adheres when pressed together could be used, with or without reversing loops, instead of or in combination with shoelace and eyelets. A greater or lesser number of straps, or eyelets could be used. An adjustable size closure assembly could be used, for example as set forth in U.S. Pat. No. 5,814,002, instead of or in combination with straps bearing hook and loop material, or shoelace and eyelets.
[0044] It is understood that the invention is not confined to the embodiments set forth herein as illustrative, but embraces all such forms thereof as come within the scope of the following claims. | An ankle brace comprising a base of flexible material shaped to wrap around the sides of a foot and ankle and underneath a portion of the foot, with a support strap for protecting the anterior talofibular ligament. The two ends of the support strap are fixed to the base at or near the forward edges of the base. The strap is not otherwise fixed to the base underneath the sole of the foot, allowing the strap to move freely under the foot to conform to the particular size and shape of the foot of a particular wearer. The ankle brace features a symmetric construction which allows the ankle brace to be worn on either the left or the right foot, simplifying manufacturing and inventory management. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] None.
FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] None.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention generally relates to the field of protection devices. In particular, the invention is a solid-state disconnect device capable of preventing the flow of undesirable voltage or current transients and/or isolating equipment from undesirably high voltages or currents.
[0005] 2. Background
[0006] Traditional protection devices which function as circuit disconnects, examples including fuses and electromechanical circuit breakers, are inherently problematic. For example, such devices have low-switching speeds, require replacement after each trip event, are prone to arcing and switching bounce with associated noise and wear problems, and/or are often large on a volume basis resulting in an unwieldy package.
[0007] Solid-state technology applied to such protection devices avoids these disadvantages while offering higher reliability and longer lifetime. Accordingly, solid-state circuit disconnects have become desirable alternatives to traditional protection devices.
[0008] Various solid-state disconnect devices have been devised utilizing complex circuitry with an additional power source, examples including devices by Billings et al. in U.S. Pat. No. 4,245,184 entitled AC Solid-State Circuit Breaker, Witmer in U.S. Pat. No. 5,606,482 entitled Solid State Circuit Breaker, Partridge in U.S. Pat. No. 6,104,106 entitled Solid State Circuit Breaker, and Covi et al. in U.S. Pat. No. 6,515,840 entitled Solid State Circuit Breaker with Current Overshoot Protection. However, it is more desirable that a circuit protection device includes two terminals and no additional power source, much like a fuse.
[0009] Harris, in U.S. Pat. No. 5,742,463 entitled Protection Device using Field Effect Transistors, describes a two-terminal, solid-state protection device without an additional power supply. Several disadvantages are noteworthy. First, the protection device requires p-channel, high-voltage field-effect-transistors (FETs) which generally have a high conduction resistance because of low hole mobility. Second, the protection device requires both gate-to-source terminals and gate-to-drain terminals of the FETs to have the same high-voltage blocking capability which is difficult to achieve because FETs block the voltage between the drain-to-source and drain-to-gate terminals, and the gate-to-source terminal generally does not have such blocking capability. For example, the gate and source terminals of all known FETs typically block a few volts to a few tens of volts because of a low-voltage Schottky barrier diode in MESFETs, a low-voltage PN diode in JFETs, and a low-voltage MOS capacitor in MOSFETs. Third, the protection device requires a large number of FETs connected in series to increase the voltage blocking capability of the device, inevitably resulting in a higher conduction loss. Fourth, the tripping current is difficult to control with the protection device.
[0010] Therefore, what is required is a solid-state disconnect device having two terminals and no additional power supply that avoids the disadvantages of the related arts.
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide a solid-state disconnect device having two terminals and no additional power supply that avoids the disadvantages of the related arts.
[0012] For high-voltage and high-current protection, silicon (Si) power devices are generally connected in parallel with the system to be protected because such devices have a high insertion loss and a large capacitance which dissipate too much power in a power system or reduce the communication bandwidth in a communication system when connected directly in series. With the introduction of wide bandgap semiconductor power devices, such as those based on silicon carbide (SiC), gallium nitride (GaN), and diamond, direct serial connectivity of protection devices in the circuit or system to be protected is more feasible at voltages over 10,000 volts, because these wide bandgap switches have a specific ON-state resistance nearly a thousand times lower than silicon components. The benefits include improved insertion loss, speed, and bandwidth and lower costs.
[0013] The solid-state disconnect device described herein is a two-terminal protection device connectable in series between a power supply and a load while avoiding an additional power source. The disconnect device further includes a depletion mode circuit block (DCB), an enhancement mode circuit block (ECB), an enhancement mode circuit block (ECB) with a positive threshold voltage, and a current limiting load (CLL). The CLL could be a simple resistor or a dynamic load formed by a circuit having a resistance that increases with terminal voltage.
[0014] The DCB is broadly defined as a circuit block having three terminals, namely a drain, source, and gate, and a negative threshold voltage that controls the current conduction between the drain and source terminals. When the voltage across the gate and source terminals is larger than the negative threshold voltage, the circuit block is turned ON and current conduction between the drain and source terminals increases with an increase in voltage across the gate and source terminals. When the voltage across the gate and source terminals is below the negative threshold voltage, the circuit block is OFF and negligible current flows through the circuit block.
[0015] The DCB could include a variety of designs composed of single and multiple components. In its simplest form, the DCB could be a single depletion mode n-channel transistor. In other embodiments, the DCB could be composed of any number of depletion mode n-channel transistors connected in a serial and/or a parallel arrangement. The depletion mode n-channel transistors should withstand the surge voltage and surge current of the application. Exemplary depletion mode components include junction field effect transistors (JFETs), metal oxide semiconductor field effect transistors (MOSFETs), static induction transistors, and insulated-gate bipolar transistors (IGBTs); however, depletion mode JFETs are generally preferred. The desired features of the depletion mode transistors include a low insertion loss, a low capacitance, and ability to withstand a surge current and voltage without breakdown. Depending on the specific application, the voltage blocking capability could be up to a few tens of thousands of volts while the current capability could be up to a few thousands of amperes.
[0016] The ECB is broadly defined herein as a circuit block having three terminals, namely a drain, source, and gate, and a positive threshold voltage. When the voltage across the gate and source terminals is larger than the positive threshold voltage, the circuit block is turned ON and current can flow between the drain and source terminals. When the voltage across the gate and source terminals is less than the positive threshold voltage, the circuit block is OFF.
[0017] The ECB could include a variety of designs composed of single and multiple components. In its simplest form, the ECB could be a single enhancement mode n-channel transistor. In other embodiments, any number of enhancement mode n-channel transistors could be connected in a serial and/or parallel arrangement. Exemplary enhanced mode components include junction field effect transistors (JFETs), metal oxide semiconductor field effect transistors (MOSFETs), static induction transistors, and insulated-gate bipolar transistors (IGBTs); however, enhancement mode n-channel MOSFETs are generally preferred.
[0018] In its simplest form, the solid-state disconnect or protection device could include a DCB, a first ECB, a second ECB, and a CLL. The DCB and first ECB are connected in a serial arrangement so as to form the current path of the two-terminal protection device. The source terminal of the DCB is connected to the drain terminal of the first ECB. The drain terminal of the second ECB is connected to the gate terminal of the first ECB and further connected through the CCL to the drain terminal of the first ECB. The gate terminal of the DCB and the source terminal of the second ECB are connected and further connected to the source terminal of the first ECB. The gate terminal of the second ECB is connected to the drain terminal of the first ECB. The voltage drop across the protection device, which increases as surge current increases, is used to control the OFF and ON status of the second ECB. The OFF and ON status of the second ECB in turn controls the OFF and ON status of the first ECB which in turn further controls the OFF and ON status of the DCB. The described circuit architecture provides protection functionality to a disconnect system or equipment protected from a high-voltage spike, and undesirable surge current flowing from the drain-to-source of the DCB and further through the drain-to-source of the first ECB.
[0019] The protection device described herein could include optional components to further improve the performance of the disconnect system. For example, in applications requiring current to flow in both directions, a current bypass component, which conducts current in one direction and blocks current in the other direction, one non-limiting example being a Schottky diode, could be connected to the source and drain terminals of the DCB or the first ECB to allow current to flow from source to drain terminals, when the DCB or the first ECB has poor or no current conduction capability from the source-to-drain terminals. In another example, a low-pass RC network could be connected between the drain terminal of the DCB and the source terminal of the first ECB to filter out high-frequency voltage spikes generated during transient and tripping events. In yet another example, a voltage-limiting component, examples including but not limited to a reverse selenium rectifier, a varistor, a simple resistor, a circuit block, or preferably a voltage-clamping Zener diode, could be connected to the source and gate terminals of each of the ECBs to prevent the gate from electric breakdown because of a high voltage. In still another example, a temperature compensation component, one non-limiting example being a thermistor with a negative temperature coefficient in resistance, could be connected between the gate and source terminals of the second ECB to make the tripping current insensitive to temperature change. In still yet another example, a variable resistor could be connected between the gate and source terminals of the second ECB to adjust the tripping current. In yet still another example, a capacitor can be connected between the gate and source terminals of the second ECB to suppress voltage spikes across the gate and source terminals of the second ECB so as to prevent premature trigger of the device. The gate terminal of the second ECB should be connected through a current limiting load instead of connected directly to the drain terminal of the first ECB, when at least one of the aforementioned optional components is connected between the gate and source terminals of the second ECB in order to ensure that a large enough voltage is established across the first ECB when the first ECB is turned OFF so as to enable the turn OFF of the DCB.
[0020] For higher current protection, it is preferable that the drain terminal of the second ECB be connected through a CLL to the drain of the DCB, rather than to the drain of the first ECB, and the gate of the second ECB be connected through another CLL to the drain of the DCB, rather than directly to the drain of the first ECB.
[0021] The protection device described herein could be arranged in either a unidirectional or a bidirectional circuit. For unidirectional protection, the device could include one form of the circuit described above. For bidirectional protection, two such circuits could be connected in mirror symmetry in a serial arrangement with a load. In the latter, it is preferred for the drain terminals of the DCBs of the two circuits to be connected, although the two source terminals of the DCBs could also be connected in mirror symmetry. For bidirectional protection, it is further preferred that both gates of the ECBs in one circuit be connected through their respective CLLs to the source terminal of the first ECB in the other circuit instead of to the drain of the DCB in the same circuit, although connecting only one of the two gates of the ECBs in one circuit to the source of the first ECB in the other circuit is also possible. Optional components described herein could be added to bidirectional embodiments of the invention as required.
[0022] Several advantages are offered by the invention. The disconnect device provides unidirectional and bidirectional protection against surge current and voltage, resets automatically, has a very-high tripping speed on the order of microseconds to sub-microseconds, is capable of protecting both DC and AC power systems, facilitates adjustments to and control of tripping current, and is insensitive to temperature variations.
REFERENCE NUMERALS
[0000]
1 Terminal
2 Terminal
3 Terminal
4 Terminal
5 , 5 a, 5 b DCB
6 , 6 a, 6 b First ECB
7 , 7 a, 7 b Second ECB
8 , 8 a, 8 b CLL
9 , 9 a, 9 b Second CLL
10 , 10 a, 10 b Voltage limiting component
11 , 11 a, 11 b Voltage limiting component
12 , 12 a, 12 b Temperature compensation component
13 , 13 a, 13 b Variable resistor
14 , 14 a, 14 b Capacitor
15 , 15 a, 15 b Resistor
16 , 16 a, 16 b Capacitor
17 , 17 a, 17 b Current bypass component
18 , 18 a, 18 b Current bypass component
19 Capacitor
20 Resistor
30 , 30 a, 30 b First node
31 , 31 a, 31 b Second node
32 , 32 a, 32 b Third node
33 , 33 a, 33 b Fourth node
34 , 34 a, 34 b Fifth node
35 , 35 a, 35 b Sixth node
36 , 36 a, 36 b Seventh node
40 Depletion mode FET
41 Feedback resistor
42 Depletion mode FET
43 Resistor
44 Depletion mode FET
50 Protection device
52 Protection device
54 Protection device
56 , 56 a, 56 b Protection device
58 Protection device
60 Protection device
61 Protection device
62 Bidirectional protection device
63 Bidirectional protection device
64 Bidirectional protection device
65 Bidirectional protection device
81 Terminal
82 Terminal
83 Terminal
84 Terminal
BRIEF DESCRIPTION OF THE INVENTION
[0070] Additional aspects, features, and advantages of the invention will be understood and will become more readily apparent when the invention is considered in the light of the following description made in conjunction with the accompanying drawings.
[0071] FIG. 1 a is a circuit diagram illustrating a solid-state protection device in accordance with an embodiment of the invention.
[0072] FIG. 1 b is a circuit diagram illustrating the solid-state protection device from FIG. 1 a with optional components in accordance with an embodiment of the invention.
[0073] FIG. 1 c is a circuit diagram illustrating the solid-state protection device from FIG. 1 b wherein the depletion mode circuit block is a depletion mode n-channel JFET and the enhancement mode circuit blocks are each an enhancement mode MOSFET in accordance with an embodiment of the invention.
[0074] FIG. 2 a is a circuit diagram illustrating alternate connectivity of the CLLs in the solid-state protection device from FIG. 1 b in accordance with an embodiment of the invention.
[0075] FIG. 2 b is a circuit diagram illustrating alternate connectivity of the CLLs in the solid-state protection device from FIG. 1 b in accordance with an embodiment of the invention.
[0076] FIG. 2 c is a circuit diagram illustrating alternate connectivity of the CLLs in the solid-state protection device from FIG. 1 b in accordance with an embodiment of the invention.
[0077] FIG. 2 d is a circuit diagram illustrating an alternate configuration of the solid-state protection device in FIG. 2 a wherein the depletion mode circuit block is a depletion mode n-channel JFET and the enhancement mode circuit blocks are each an enhancement mode MOSFET in accordance with an embodiment of the invention.
[0078] FIG. 3 a is a circuit diagram illustrating a bidirectional protection device including a pair of solid-state protection devices from FIG. 2 a connected in a serial arrangement in accordance with an embodiment of the invention.
[0079] FIG. 3 b is a circuit diagram illustrating a bidirectional protection device including a pair of solid-state protection devices from FIG. 2 d connected in a serial arrangement in accordance with an embodiment of the invention.
[0080] FIG. 4 a is a circuit diagram illustrating an alternate configuration of the bidirectional protection device from FIG. 3 a in accordance with an embodiment of the invention.
[0081] FIG. 4 b is a circuit diagram illustrating an alternate configuration of the bidirectional protection device from FIG. 3 b in accordance with an embodiment of the invention.
[0082] FIG. 5 a is a plot illustrating the simulated current waveform in expanded scale produced by the bidirectional protection device in FIG. 4 b protecting a single-phase 10-kilowatt DC-to-DC converter system powered by a 200 volt battery when a fault causes the battery discharge current to rise sharply.
[0083] FIG. 5 b is a plot illustrating the simulated current waveform produced by the bidirectional protection device in FIG. 4 b protecting a single-phase 10-kilowatt DC-to-DC converter system powered by a 200 volt battery when a fault causes the battery discharge current to rise sharply and after the system resumes normal operation after the fault is cleared.
[0084] FIG. 6 is a plot illustrating the simulated current waveform in expanded scale produced by the bidirectional protection device in FIG. 4 b protecting a single-phase 10-kilowatt DC-to-DC converter system powered by a 200 volt battery when a fault causes the battery charge current to rise sharply.
[0085] FIG. 7 is a plot illustrating the effects of temperature compensation components on the trip current of the bidirectional protection device in FIG. 4 b.
[0086] FIG. 8 is a plot illustrating the effects of current bypass components (power diodes) on reducing the forward voltage drop across the bidirectional protection device in FIG. 4 b.
[0087] FIG. 9 is a plot illustrating the lower conduction voltage drop of the bidirectional protection device in FIG. 4 b in comparison to the forward voltage drop of the bidirectional protection device in FIG. 3 b.
[0088] FIG. 10 a is a plot illustrating the measured current tripping waveforms of the bidirectional protection device in FIG. 4 b with a trip current of 53 amperes.
[0089] FIG. 10 b is a plot illustrating the measured current tripping waveforms of the bidirectional protection device in FIG. 4 b with a trip current of 55 amperes.
DETAILED DESCRIPTION
[0090] Reference will now be made in detail to several preferred embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts. Nodes are referenced for descriptive purposes only and do not necessarily represent a structure or element of the invention. The drain, gate, and source terminals of components are identified by the letters D, S, and G, respectively, in FIGS. 1 a - 1 c, 2 a - 2 d, 3 a, 3 b, 4 a, and 4 b.
[0091] Referring now to FIG. 1 a, an embodiment of the protection device 50 is shown for a unidirectional device capable of preventing a surge current that exceeds a preset trip value between terminals 1 and 3 , by disconnecting a load at terminals 3 and 4 in response to a voltage surge. The protection device 50 is connected in series between a source or voltage supply across terminals 1 and 2 with the polarity shown and the load across terminals 3 and 4 . The protection device 50 includes a DCB 5 , a first ECB 6 , a second ECB 7 , and a CLL 8 connected as shown via nodes 30 - 36 . The DCB 5 is a depletion mode circuit block with a negative threshold voltage. The first ECB 6 and second ECB 7 are enhancement mode circuit blocks with a positive threshold voltage. The drain terminal of the DCB 5 is connected to the first node 30 . The gate terminal of the DCB 5 and the source terminals of the first ECB 6 and the second ECB 7 are connected to the third node 32 . The source terminal of the DCB 5 and the drain terminal of the first ECB 6 are connected to the second node 31 . The gate terminal of the first ECB 6 and the drain terminal of the second ECB 7 are connected to the fifth node 34 . The gate terminal of the second ECB 7 is connected to the sixth node 35 . The CLL 8 is connected between the fourth node 33 and fifth node 34 . Thereafter, the second node 31 , fourth node 33 , sixth node 35 , and seventh node 36 are arranged and connected as shown.
[0092] The functionality of the protection circuit 50 is described with further reference to FIG. 1 a. In normal operation, a positive current flows from terminal 1 to terminal 3 . The voltage drop across the second node 31 and the third node 32 is larger than the threshold voltage of the first ECB 6 but smaller than the threshold voltage of the second ECB 7 . As such, the first ECB 6 is maintained in the ON-state while the second ECB 7 is in the OFF-state during normal operating conditions. The DCB 5 is in the ON-state as a normally ON device and the magnitude of its gate-to-source voltage, approximately equal to the magnitude of the voltage drop across the third node 32 and second node 31 , is smaller than the magnitude of its negative threshold voltage.
[0093] When a surge current or sudden voltage increase at terminal 1 attempts to cross to terminal 3 , the voltage drop between the second node 31 and third node 32 momentarily increases, resulting in a momentary increase in the gate voltage of the second ECB 7 . The second ECB 7 remains in the OFF-state until the voltage drop between the second node 31 and third node 32 reaches the threshold voltage of the second ECB 7 placing the second ECB 7 in the ON-state at a predetermined surge current. The peak surge current at which the disconnect trips is therefore controlled by the magnitude of the threshold voltage of the second ECB 7 and the forward characteristics of the first ECB 6 . After the second ECB 7 is turned ON, the voltage drop across the drain terminal, at the fifth node 34 , and the source terminal, at the third node 32 , of the second ECB 7 is decreased to a value less than the threshold voltage of the first ECB 6 so as to turn OFF the first ECB 6 . Once the first ECB 6 is OFF, current is forced to pass through the CLL 8 and the second ECB 7 . The CLL 8 produces a voltage drop across the second node 31 and third node 32 coupled to the source and gate terminals of the DCB 5 , respectively. The first ECB 6 should be sufficiently capable of handling a drain-to-source voltage larger than the numerical value of the negative threshold voltage of the DCB 5 . A typical threshold voltage for the DCB 5 could be in the range of −1 volts to −50 volts, although other values are possible. When the drain-to-source voltage of the first ECB 6 increases to a value greater than the numerical value of the threshold voltage of the DCB 5 , the DCB 5 is turned OFF. Thereafter, the protection circuit 50 enters the OFF-state so as to prevent the surge current from reaching and damaging the load and to disconnect the load from the high-voltage spike. The protection device 50 resumes normal operation automatically once the voltage drop across the device from terminals 1 to 3 decreases to a value causing the second ECB 7 to turn OFF after the fault causing the current surge is cleared.
[0094] A single DCB 5 comprising a high-voltage depletion mode n-channel transistor could be employed to disconnect the surge voltage because the voltage blocked by the DCB 5 is across the drain and source rather than across the gate and source as provided in U.S. Pat. No. 5,742,463. For example, a single silicon carbide FET could be used to block a voltage surge over 10,000 volts, non-limiting examples being a 10kV, 5 A 4H—SiC Power DMOSFET and a 10 kV, 87 mΩ-cm 2 normally-OFF 4H—SiC Vertical Junction Field-Effect Transistor. The corresponding DCB 5 and first ECB 6 should have similar current handling capability dependent on the specific application, which could range from a few milli-amperes to a few tens of thousands of amperes. The second ECB 7 would not necessarily require a high current capability because it is limited by the CLL 8 .
[0095] Referring now to FIG. 1 b, the protection device 50 from FIG. 1 a is shown with a variety of optional components to form various alternate protection devices 52 . The architecture of the protection device 52 is identical to that in FIG. 1 a, except where otherwise indicated. For example, a second CLL 9 could be provided between the sixth node 35 and seventh node 36 . A voltage limiting component 10 could be connected as needed between the gate and source terminals of the first ECB 6 to prevent electric breakdown of the gate due to a high voltage event. Another voltage limiting component 11 could be connected as needed between the gate and source terminals of the second ECB 7 , so as to prevent electric breakdown of the gate due to a high voltage event. Although Zener diodes are represented in FIG. 1 b, any voltage-limiting components, non-limiting examples including reverse selenium rectifiers, varistors made from various materials, a simple resistor, or a circuit block, but preferably a voltage-clamping Zener diode, could be employed as one or both voltage limiting components 10 , 11 .
[0096] Referring again to FIG. 1 a, the ON-state resistances of the DCB 5 and first ECB 6 increase and the threshold voltage of the second ECB 7 decreases as the temperature of the protection device 50 increases. As a consequence, the trip current of protection device 50 will decrease.
[0097] Referring again to FIG. 1 b, the protection device 52 could include a temperature compensation component 12 with a negative temperature coefficient (NTC) in resistance, a non-limiting example being an NTC thermistor, in order to maintain a relatively constant trip current. The temperature compensation component 12 could be connected between the gate and source terminals of the second ECB 7 . The temperature compensation component 12 and second CLL 9 form a voltage divider. A decrease in the resistance of the temperature compensation component 12 with an increase in temperature tends to reduce the voltage drop across the gate and source terminals of the second ECB 7 . As a result, an increase in the ON-resistance of the DCB 5 and the first ECB 6 and a decrease in the threshold voltage of the second ECB 7 due to a temperature increase are compensated by the decrease in the bias voltage across the gate-to-source terminals of the second ECB 7 . Hence, the trip current of the protection device 52 could be nearly temperature independent over a specified range of temperatures.
[0098] Referring again to FIG. 1 b, an optional variable resistor 13 could also be connected between the gate and source terminals of second ECB 7 to adjust the voltage drop across the gate and source terminals so as to adjust the trip current. An optional capacitor 14 could be further connected between the gate and source terminals of the second ECB 7 to suppress potential voltage spikes across the gate and source terminals to prevent a premature trigger of the second ECB 7 . An optional RC network could be further connected between the first node 30 and the third node 32 , preferably after the capacitor 14 , to filter out high-frequency voltage spikes generated during transient and trip conditions. One non-limiting exemplary embodiment of the RC network is a resistor 15 and capacitor 16 , as represented in FIG. 1 b.
[0099] Referring again to FIG. 1 b, the protection device 52 could further include current bypass components 17 , 18 as required, which conduct current in one direction and block current in the other direction. The simplest form of a current bypass component is a Schottky diode, although other components are possible. The current bypass components 17 , 18 could be connected in parallel to the current conducting channel between the source and drain terminals of the DCB 5 and first ECB 6 , respectively, when an application requires current to flow from terminal 3 to terminal 1 , and when the DCB 5 or first ECB 6 has poor or no current conducting capability from source-to-drain terminals. For example, MOSFETs contain a built-in body diode between its source and drain terminals which allows current conduction from source-to-drain but with a relatively large voltage drop. As such, it is preferred that a low-voltage-drop current bypass diode be connected between the source and drain terminals of each MOSFET. In another example, IGBTs do not include a body diode so a low-voltage-drop current bypass diode could be included to provide reverse current conduction when a specific application requires current to flow from terminal 3 to terminal 1 .
[0100] The functionality of the protection device 52 of FIG. 1 b is similar to the protection device 50 of FIG. 1 a. The protection device 52 is a unidirectional protection device capable of preventing a surge current that exceeds a preset trip current to conduct from terminal 1 to terminal 3 and disconnecting the load from a voltage surge. However, current conduction in the protection device 52 is bidirectional.
[0101] The CLLs 8 , 9 in FIGS. 1 a and 1 b could include a variety of devices. Each CLL 8 , 9 could be a resistor with a predetermined value of resistance. Preferably, each CLL 8 , 9 could be a dynamic load formed by a circuit block having increased resistance with increased terminal voltage in order to reduce power dissipation. For example, the CLL 8 in FIG. 1 a is shown including a depletion mode FET 40 and a feedback resistor 41 capable of providing a small load resistance for a short RC charge time for the first ECB 6 at low voltage and a very large load resistance to limit the leakage current in a high-voltage blocking mode.
[0102] The DCBs 5 , 5 a, 5 b described herein could include a variety of single and multi-element devices. In one example, the DCBs 5 , 5 a, 5 b could be composed of any number of depletion mode n-channel transistors connected in a serial and/or parallel arrangement. In another example, the DCB 5 , 5 a, 5 b could be a single depletion mode n-channel transistor, non-limiting examples including a depletion mode n-channel junction field effect transistor (JFET), a depletion mode n-channel metal oxide semiconductor field effect transistor (MOSFET), and a depletion mode insulated-gate bipolar transistor (IGBT).
[0103] The ECBs 6 , 6 a, 6 b, 7 , 7 a, 7 b described herein could include a variety of single and multi-element devices. In one example, the ECBs 6 , 6 a, 6 b, 7 , 7 a, 7 b could include any number of enhancement mode n-channel transistors connected in a serial or parallel arrangement. An ECB 6 , 6 a, 6 b, 7 , 7 a, 7 b in its simplest form could be a single enhancement mode n-channel transistor, non-limiting examples including an enhancement mode n-channel junction field effect transistor (JFET), an enhancement mode n-channel metal oxide semiconductor field effect transistor (MOSFET), and an enhancement mode insulated-gate bipolar transistor (IGBT).
[0104] Referring now to FIG. 1 c, the protection device 54 is shown whereby the DCB 5 is a depletion mode n-channel JFET and the ECBs 6 , 7 are each one enhancement mode MOSFET. Components and architecture are identical to those in FIG. 1 b, except where otherwise noted. For example, the optional current bypass component 17 is not required because the depletion mode n-channel JFET has good current conduction performance from source-to-drain terminals. The functionality of the protection device 54 in FIG. 1 c is similar to the protection device 52 in FIG. 1 b, in that the protection device 54 is a unidirectional device capable of preventing a surge current that exceeds a preset trip current to cross from terminal 1 to terminal 3 and disconnecting the load from a voltage surge.
[0105] The ECBs 6 , 6 a, 6 b, 7 , 7 a, 7 b described herein generally have a gate-to-source voltage larger than the threshold voltage required to turn ON the circuit block. The higher the gate-to-source voltage is, the lower the ON-state voltage drop for the same current level is. For the first ECB 6 in FIG. 1 b, the ON-state voltage drop is fed back to its gate to keep the ECB 6 in its ON-state. In general applications, it is desired that the ON-state voltage drop of the first ECB 6 to be as low as possible so as to reduce power loss. Therefore, the first ECB 6 should have a positive but low threshold voltage.
[0106] FIGS. 2 a - 2 d describe several alternate embodiments of the protection device 52 in FIG. 1 b. Components and architecture are identical to those in FIG. 1 b, except where otherwise noted. The protection devices 56 , 58 , 60 , and 61 allow bidirectional current conduction, although the protection function is unidirectional. Operation of the protection devices 56 , 58 , 60 , and 61 are similar to that of the protection device 52 of FIG. 1 b. The circuit in FIG. 2 a is a preferred embodiment.
[0107] Referring now to FIG. 2 a, an improved embodiment the protection device 56 is shown which reduces the ON-state voltage drop of the first ECB 6 in FIG. 1 b. The fourth node 33 and seventh node 36 are now connected to the first node 30 rather than to second node 31 . As such, the entire voltage drop across the protection device 56 , including the voltage drop across the drain and source terminals of the DCB 5 and across the drain and source terminals of the first ECB 6 , is employed to bias the gate and source terminals of the first ECB 6 . For the same level of current conducting through the protection device 56 , the voltage available to bias the gate and source terminals of the first ECB 6 in FIG. 2 a is much larger than that in FIG. 1 b. Therefore, the forward voltage drop of the first ECB 6 in FIG. 2 a is smaller than the forward voltage drop of the first ECB 6 in FIG. 1 b. Accordingly, the ON-state forward voltage drop or the insertion loss of the protection device 56 is smaller than that of the previously described protection device 52 .
[0108] Referring again to FIG. 2 a, the voltage drop across the gate and source terminals of the second ECB 7 is much larger than that in FIG. 1 b for the same current level because of the connection of the seventh node 36 to first node 30 . This allows the threshold voltage of the second ECB 7 in FIG. 2 a to be larger than that in FIG. 1 b. A larger threshold voltage in practice is easier to achieve.
[0109] Referring again to FIG. 2 a, the voltage limiting component 11 is required to prevent the gate-source terminals of the second ECB 7 from being exposed to a damaging high voltage, and second CLL 9 is required to support most of the voltage drop across the protection device 56 and to limit the current flowing through the voltage limiting component 11 after the protection device 56 is tripped into the blocking OFF-state. The CLL 8 will also support most of the voltage drop across protection device 56 and limit the current flowing through the second ECB 7 and the voltage limiting component 10 after the protection device 56 is tripped into the blocking OFF-state. A resistor with a predetermined value of resistance could be employed as the CLL 8 and second CLL 9 ; however, a dynamic load formed by a circuit block is otherwise preferred, as described herein. The CLL 8 and second CLL 9 are preferred to be a depletion-mode transistor and a feedback resistor as shown in FIG. 1 a, except in this embodiment the depletion-mode transistor should have a voltage blocking capability similar to that of the DCB 5 , because the CLLs 8 , 9 could be subject to a high surge voltage. The transistors of the CLL 8 and second CLL 9 do not require high current capability because high current is not gene rally conducted through these elements.
[0110] The operation of the protection device 56 in FIG. 2 a is similar to the protection device 52 in FIG. 1 b. As illustrated in FIG. 2 a, the source or supply voltage is connected across terminals 1 and 2 with the polarity shown and the load is connected across terminals 3 and 4 . In normal operation, both the DCB 5 and first ECB 6 are ON, and the second ECB 7 is OFF. When a surge current enters from terminal 1 to terminal 3 , the voltage drop across protection device 56 will momentarily increase, resulting in a momentary increase in the voltage drop across the gate and source terminals of the second ECB 7 . Thereafter, the second ECB 7 turns ON when the voltage drop across its gate and source terminals reaches the threshold voltage of the second ECB 7 . After the second ECB 7 is turned ON, the voltage drop across its drain and source terminals decreases until it is lower than the threshold voltage of the first ECB 6 so that the first ECB 6 is turned OFF. Once the first ECB 6 is OFF, the voltage drop across the drain and source terminals of the first ECB 6 increases substantially which in turn turns OFF the DCB 5 to block the surge voltage, which could be up to thousands or tens of thousands of volts. The result is that the protection device 56 effectively isolates the load from the supply voltage and any damaging current and voltage.
[0111] Referring now to FIG. 2 b, the fourth node 33 is now connected to the second node 31 and the seventh node 36 is connected to the first node 30 . The protection device 58 does not necessarily have a better insertion loss than the device in FIG. 1 b, but rather allows the threshold voltage of the second ECB 7 to be much larger than in FIG. 1 b.
[0112] Referring now to FIG. 2 c, the seventh node 36 is now connected to the second node 31 and the fourth node 33 is connected to the first node 30 . The protection device 60 improves the insertion loss otherwise achievable by the protection device 52 in FIG. 1 b.
[0113] Referring now to FIG. 2 d, the protection device 56 in FIG. 2 a is shown with a depletion mode n-channel JFET at the DCB 5 and an enhancement mode MOSFET at the first ECB 6 and second ECB 7 . The current bypass component 17 in FIG. 2 a is not required because the depletion mode n-channel JFET has good current conduction capability from source-to-drain terminals.
[0114] Bidirectional power systems, one non-limiting example being a bidirectional DC-DC converter, are gaining increased attentions in a wide range of applications including hybrid and electric vehicles where a battery delivers and receives energy. Bidirectional power systems require bidirectional protection devices. In accordance with embodiments of the invention, a bidirectional protection device could be constructed with two unidirectional protection devices.
[0115] Referring now to FIG. 3 a, a bidirectional protection device 62 is shown constructed with two protection devices 56 a, 56 b, as described in FIG. 2 a. A bidirectional source or supply voltage is connected across terminals 81 and 82 and a load is connected across terminals 83 and 84 . The bidirectional protection device 62 is capable of protecting both load and source from excessive positive and negative current and voltage surges.
[0116] The protection device 56 b is identical in its construction to the protection device 56 in FIG. 2 a and similar in operation thereto in that it is operative to limit the positive surge current conducting from terminal 81 to terminal 83 . The protection device 56 b includes notation similar to that in FIG. 2 a to identify the various components and nodes, except that the reference numerals for are distinguished by the suffix “b”.
[0117] The protection device 56 a is identical in its construction to the protection device 56 in FIG. 2 a and operates in a similar manner to the protection device 56 b, except that it is responsive to limit the negative surge of current from terminal 83 to terminal 81 . The protection device 56 a includes notation similar to that in FIG. 2 a to identify the various components and nodes, except that the reference numerals for are distinguished by the suffix “a”.
[0118] Referring again to FIG. 3 a, the relative positions of the protection devices 56 a and 56 b could be transposed, meaning one protection device 56 a is closer to the load than the other protection device 56 b, the third node 32 a is connected to the other third node 32 b, the first node 30 a is connected to one terminal 83 instead of to the first node 30 b, and the first node 30 b is connected to the other terminal 81 . However, it is preferred that the first node 30 a and other first node 30 b be connected together as illustrated in FIG. 3 a, because the ON resistance of the bidirectional protection device 62 could be improved, as discussed herein.
[0119] Referring now to FIG. 3 b, the bidirectional protection device 63 includes the bidirectional protection device 62 in FIG. 3 a wherein the DCBs 5 a, 5 b are each a depletion mode n-channel JFET and the ECBs 8 a, 8 b, 9 a, 9 b are each an enhancement mode MOSFET. Components and architecture are otherwise identical to the bidirectional protection device 62 , except where otherwise noted. For example, the current bypass components 17 a and 17 b in the bidirectional protection device 62 are not required because of the conduction properties of the depletion mode n-channel JFET from source to drain terminals. Operation of the bidirectional protection device 63 is similar to that of the device in FIG. 3 a.
[0120] The ON-resistance or insertion loss of the bidirectional protection device 62 in FIG. 3 a could be reduced where the total voltage drop across the protection devices 56 a, 56 b is used to bias the gates of the first ECBs 6 a, 6 b.
[0121] FIGS. 4 a and 4 b show two possible embodiments of a bidirectional protection device 64 and 65 , respectively, that separately prevents a surge current that exceeds a preset tripping current from passing through the device and disconnects a load in response to a voltage surge.
[0122] Referring now to FIG. 4 a, the bidirectional protection device 64 is shown based on the protection device 62 in FIG. 3 a. Components, nodes, and architecture are identical to that in FIG. 3 a, except where otherwise noted. For example, the two optional RC networks of FIG. 3 a, each including a resistor 15 a or 15 b and a capacitor 16 a or 16 b, are combined into one optional RC network in FIG. 4 a, formed by a capacitor 19 and a resistor 20 connected parallel to the third nodes 32 a, 32 b. The fourth node 33 b and seventh node 36 b are connected to the third node 32 a rather than to the first node 30 b in FIG. 3 a. The fourth node 33 a and seventh node 36 a are connected to the third node 32 b rather than to the first node 30 a in FIG. 3 a. In other embodiments, it is possible for only the fourth node 33 b or seventh node 36 b to be connected to the third node 32 a and/or for only the fourth node 33 a or seventh node 36 a to be connected to the third node 32 b.
[0123] Referring again to FIG. 4 a, the CLLs 8 a, 8 b, 9 a, and 9 b should allow for bidirectional current limiting and high voltage handling. In some embodiments, the CLLs 8 a, 8 b, 9 a, 9 b could each be implemented as a simple current limiting resistor. However, it is preferred that each CLL 8 a, 8 b, 9 a, 9 b include a pair of depletion mode FETs 42 , 44 and a shared resistor 43 , as shown in FIG. 4 a. This arrangement ensures that the resistance of each CLL 8 a, 8 b, 9 a, 9 b is low when the voltage across each CLL 8 a, 8 b, 9 a, 9 b is low so as to achieve a small RC charging time and a high resistance when the voltage across each CLL 8 a, 8 b, 9 a, 9 b is high so as to limit leakage current when the bidirectional protection device 64 is in the blocking or OFF state. While JFETs are illustrated in FIG. 4 a, any depletion mode transistor, non-limiting examples including MOSFETs and IGBTs, are applicable to the CLLs 8 a, 8 b, 9 a, 9 b.
[0124] Referring again to FIG. 4 a, the entire voltage drop across the bidirectional protection device 64 is applied to the gate of the first ECB 6 b to reduce its ON resistance when current flows from one terminal 81 to another terminal 83 . Similarly, when current flows from one terminal 83 to another terminal 81 , the entire voltage drop across the bidirectional protection device 64 is applied to the gate of first ECB 6 a to reduce its ON resistance. The increased gate-to-source bias voltage lowers the conduction power loss by reducing the conduction voltage drop of the first ECBs 6 a, 6 b.
[0125] Referring again to FIG. 4 a, the bidirectional protection device 64 is functionally similar to the bidirectional protection device 62 in FIG. 3 a. When current flows from one terminal 83 to another terminal 81 under normal operating conditions, the DCB 5 a and first ECB 6 a are in the ON-state and the DCB 5 b and first ECB 6 b are in a reverse conduction state. Conversely, when current flows from one terminal 81 to another terminal 83 , the DCB 5 b and first ECB 6 b are in the ON-state and the DCB 5 a and first ECB 6 a are in the reverse conduction state. If any of the DCBs 5 a, 5 b and/or first ECBs 6 a, 6 b has either poor or no reverse current conduction capability, the reverse current flows through the appropriate current bypass component 17 a, 17 b, 18 a, 18 b.
[0126] If surge current flows from terminal 81 to terminal 83 , then the voltage drop across the bidirectional protection device 64 , between nodes 32 a and 32 b, will momentarily increase, resulting in an increase in the gate-to-source bias voltage at the second ECB 7 b. The second ECB 7 b is turned ON at a predetermined surge current, dependent on the threshold voltage of the component. Once the second ECB 7 b is turned ON, the voltage across the drain and source terminals of the second ECB 7 b decreases to a very small value below the threshold voltage of the first ECB 6 b so that the first ECB 6 b is turned OFF. The shut-off of the first ECB 6 b causes a large voltage drop across the drain and source of the first ECB 6 b, which is provided as a reverse bias to the gate-to-source terminals of the DCB 5 b to choke off its conducting channel and turn OFF the DCB 5 b. As a result, the bidirectional protection device 64 then disconnects the load from the surge current and voltage. The surge voltage is mainly supported by the high voltage DCB 5 b, which, depending on the application, could be a single SiC FET capable of blocking up to and over 10,000 volts and conducting milli-amperes to thousands of amperes. Similarly, if a surge current flows from terminal 83 to terminal 81 , the second ECB 7 a is turned ON, depending on the threshold voltage the component, at a predetermined surge current causing the first ECB 6 a and DCB 5 a to turn OFF so that the bidirectional protection device 64 disconnects the load from the surge current and voltage, and the high voltage drop across the bidirectional protection device 64 is mainly supported by the high-voltage DCB 5 a which, depending on applications, could also be a single SiC FET sufficiently capable of blocking over 10,000 volts and conducting milli-amperes to thousands of amperes. The bidirectional protection device 64 resumes normal operation automatically once the voltage drop across the device decreases to a value that turns OFF either of the second ECBs 7 a, 7 b after the fault causing current surge is cleared.
[0127] Referring now to FIG. 4 b, a bidirectional protection device 65 is shown based on the bidirectional protection device 64 from FIG. 4 a, wherein the DCBs 5 a, 5 b each include one depletion mode n-channel JFET and the first and second ECBs 6 a, 6 b, 7 a, 7 b each include one enhancement mode n-channel MOSFET. Components and architecture are otherwise identical to the bidirectional protection device 64 in FIG. 4 a, except where otherwise noted. The optional current bypass components 17 a, 17 b are not required because of the current conduction capability of the depletion mode n-channel JFET. The operation of the bidirectional protection device 65 is similar to the bidirectional protection device 64 in FIG. 4 a.
[0128] With reference to FIGS. 5 a, 5 b, 6 , 7 , 8 , and 9 , the bidirectional protection system 65 in FIG. 4 b was simulated with the PSpice® computer program, sold by Cadance Design Systems, Inc. of San Jose, Calif. For simplicity, the optional RC network including the capacitor 19 and resistor 20 , the optional capacitors 14 a, 14 b, and the optional variable resistors 13 a, 13 b were not included in the simulations. Performance plots are for illustrative purposes only and are not intended to limit or otherwise restrict the scope of the embodiments described herein and their performance.
[0129] Referring now to FIGS. 5 a and 5 b, current versus time plots are shown for the bidirectional protection device 65 connected in series between a 200 volt battery and a single-phase 10 kilowatt DC-to-DC converter system powered by the 200 volt battery when a fault, such as a short circuit of the power transistor in the DC-DC converter, causes the battery discharge current to rise sharply. The current is tripped at a pre-designed level of 156 amperes and drops to below 2 amperes within 2 microseconds and then quickly drops to near zero, as shown in FIG. 5 a. After the fault is cleared, the system automatically resumes normal operation, as shown in FIG. 5 b.
[0130] Referring now to FIG. 6 , a current versus time plot is shown for the bidirectional protection device 65 connected in series between a 200 volt battery and a single-phase 10 kilowatt DC-to-DC converter system powered by the 200V battery when a fault, such as a short circuit of the other power transistor in the DC-DC converter, causes the battery charge current to rise sharply. In this example, the current is tripped at −168 amperes and drops to about −2 amperes within 2 microseconds and then quickly drops to near zero.
[0131] The simulated results in FIGS. 5 a, 5 b, and 6 demonstrate that the bidirectional protection device 65 operates at a very high speed and is capable of automatically resuming normal operation once the voltage drop across the device between the nodes 32 a and 32 b decreases to a value that turns OFF either of the second ECBs 7 a or 7 b after the fault is cleared.
[0132] Referring now to FIG. 7 , a trip current versus temperature plot is shown for the bidirectional protection device 65 with and without the temperature compensation components 12 a, 12 b. The trip current decreases sharply with an increase in temperature without the temperature compensation components 12 a, 12 b. The trip current is seen to be much less sensitive to the temperature variation over the range of 27° Celsius to 125° Celsius, when the temperature compensation components 12 a, 12 b are employed.
[0133] Referring now to FIG. 8 , a voltage drop versus current plot is shown to illustrate the effects of power diodes as the current bypass components 18 a, 18 b on the forward voltage drop of the bidirectional protection device 65 for a 10 kilowatt, 200 volt system. With the power diodes, the forward voltage drop in normal operation is reduced by about 20% or 0.3 volts at the forward current up to 50 amperes. The reduced voltage drop is a direct result of the smaller ON-state voltage drop of the power diodes in comparison to that of MOSFETs as the first ECBs 6 a and 6 b. In general, a lower ON-state voltage drop correlates to a lower insertion loss.
[0134] Referring now to FIG. 9 , a voltage drop versus current plot compares the forward voltage drop of the bidirectional protection devices 65 and 63 for a 10 kilowatt, 200 volt system. The bidirectional protection device 65 has a much smaller forward voltage drop as compared to the bidirectional protection device 63 in FIG. 3 b. The substantial reduction in the forward voltage drop or insertion loss is due to the use of the entire voltage drop of the bidirectional protection device 65 to forward bias the gate-source terminals of first ECBs 6 a, 6 b.
[0135] Referring now to FIGS. 10 a, 10 b, tripping current plots show exemplary current versus time plots for the bidirectional protection device 65 demonstrated experimentally for a 10 kilowatt DC-to-DC converter system powered by a 300 volt source. FIG. 10 a shows the measured current tripping waveforms for the surge current flowing from terminal 81 to terminal 83 . FIG. 10 b shows the measured current tripping waveforms for the surge current flowing from terminal 83 to terminal 81 . Experimental results show that the device has a trip current very close to the designed target of 50 amperes and has an extremely fast turn-off speed of less than 1 microsecond.
[0136] While depletion mode circuit blocks with a negative threshold voltage and enhancement mode circuit blocks with a positive threshold voltage based on n-channel devices are described herein, depletion mode circuit blocks with a positive threshold voltage and enhancement mode circuit blocks with a negative threshold voltage based on p-channel devices, could also be used; although, such embodiments are not preferred because of the large channel resistance of p-channel devices.
[0137] The voltage and current capability of the depletion mode circuit blocks and transistors described herein are chosen to meet specific protection requirements. For example, the protection devices are not generally required to protect against a very large current, but rather protect against very high voltages in many telecommunication applications. In another example, the protection devices for electric vehicle batteries are generally required to protect against a very large current, rather than very high voltages.
[0138] The description above indicates that a great degree of flexibility is offered in terms of the invention. Although various embodiments have been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein. | A solid-state disconnect device capable of isolating and protecting circuits and equipment from overloads and undesired transients is presented. The protection device includes at least one depletion mode circuit block having three terminals (drain, gate, and source), which in its simplest form is implemented by a single n-channel depletion mode field-effect transistor, and two enhancement mode circuit blocks each having three terminals (drain, gate and source), each implemented in simplest form by a single n-channel enhancement mode field-effect transistor. The current conducting path of the first enhancement mode circuit block is connected in series with the current conducting path of the depletion mode circuit block. The drain terminal of the second enhancement mode circuit block is connected through a current limiting load to both the gate terminal of the second enhancement mode circuit block and the drain terminal of the first enhancement mode circuit block. The gate terminal of the first enhancement mode circuit block is connected to the drain terminal of the second enhancement mode circuit block. The source terminals of the two enhancement circuit blocks are both connected to the gate terminal of the depletion mode circuit block. Unidirectional and bidirectional embodiments are disclosed. | 7 |
FIELD OF THE INVENTION
The present invention relates to a process for decontaminating inert substrate materials such as soils, sludges, sediments, drilling mud and cuttings, spent activated carbon, and wood. More particularly, the invention concerns an improved process and apparatus for thermally separating mercury and organic contaminants such as hydrocarbons, polychlorinated biphenyls (PCB's), pentachlorophenols (PCP's), polyaromatic hydrocarbons (PAH's), insecticides, herbicides, creosote, pesticides, dioxins and furans. The removed contaminants are removed as vapour without employing combustion, are collected and condensed for further treatment and recovery.
BACKGROUND OF THE INVENTION
Increasing attention has been paid to public health consequences of introducing industrial wastes, such as halogenated and non-halogenated organic compounds into the environment. As this attention has increased, governmental regulations have also been put in place to mandate the removal of these compounds to maximum permissible residual levels in the soils and other matrices of former disposal sites.
Traditionally, clean-up of disposal sites involved the procedure of removing contaminated soil or material to a designated secure land fill area. However, the number and volume of designated land fill areas has been greatly reduced and therefore a growing need to sanitize soils, and other matrices, with an efficient and economical treatment process is required.
In response to this need, portable incineration systems have been proposed, for example, U.S. Pat. No. 4,667,609 discloses a mobile apparatus for infrared heating of soils contaminated by various hydrocarbons. However, in incineration systems such as this the heating step is carried out to the point of complete combustion. Hence, operation of such a system would likely be precluded by governmental regulations which are extremely stringent with respect to the output of gases and the like from incineration systems.
An alternative to incineration is taught by U.S. Pat. No. 4,864,942 which discloses a method for removing organic compounds such as PCB's from soils by volatizing the organic compounds at temperatures well below what would be defined as “incineration”. Generally speaking, these temperatures would not exceed 1200° F.
However, the time periods necessary for treatment to effect complete volatilization of contaminants, without combustion, are extremely slow and may well be an hour or more and in the case of mercury highly unlikely.
Accordingly, there is a need for an apparatus which can maximize the heat transfer to the substrate to be treated so as to minimize treatment time. Furthermore, thermal expansion of treatment chambers may also be a problem and there is therefore a need for a treatment chamber which can preferably respond to varying temperatures of the treatment process.
SUMMARY OF THE INVENTION
In a broader embodiment of the process according to the present invention, contaminants are separated from inert substrate materials such as soils, sludges, sediments and drilling muds and cuttings by a process that subjects inert materials contaminated with mercury or an organic compound to a temperature effective to volatilize the contaminants but below combustion temperature, with continuous removal, collection, condensation of all the vapours, for a period of time sufficient to effect the desired degree of contamination removal from the inert material and prevent the release of contaminated emissions.
When applying the inventive process and apparatus to decontaminate a large amount of material, the process is preferably carried out with an indirectly heated air tight extraction chamber consisting of a suspended double troughed chamber equipped with rotating augers which maximizes the heat transfer and minimizes dust to the substrate while eliminating difficulties caused by thermal expansion of prior art chambers.
Temperatures are controlled to keep the average soil temperature of material being processed at or below 600° C. to 650° C. to ensure high removal efficiencies. At these temperatures the volatilization component of the contaminated substrate vapourizes to form a vapour phase, leaving behind an inert solid phase. The vapour phase, which contains few fine solid particles, steam, air and vapourized contaminants such as hydrocarbons and PCB's, is continuously drawn off from the chamber and is subsequently collected, condensed and recovered for recycling or disposal by appropriate procedures.
Accordingly, the invention comprises an apparatus for separating contaminants form inert substrate materials, comprising an essentially suspended air-tight processing chamber having a substrate inlet and a substrate outlet, said chamber having two or more channels for processing of the substrate, a means for indirectly heating the chamber, a means for moving substrate through the two or more troughs of the chamber from the substrate inlet to the substrate outlet, and a vapour condensate handling system for removing and condensing vapours from the chamber to remove and recover contaminants.
The invention further comprises a method for separating mercury and organic contaminants from contaminated inert substrate materials comprising the steps of feeding inert solid material contaminated with mercury and/or organic compounds into a suspended treatment chamber heated externally with a heating means to such a temperature that the mercury and organic compounds are volatilized, moving said material through the chamber in a manner which exposes a maximum surface area of the inert solid material to the indirect heat within the chamber to assist in the rapid heating and processing of the material, removing the solids free of contaminants from the chamber, removing the vapour phase constituents from the chamber and conducting to a means for condensation and recovery of contaminants.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other advantages of the invention will become apparent upon reading the following detailed description and upon referring to the drawings in which:
FIG. 1 is a process flow diagram of an exemplary operation for decontamination of substrates;
FIG. 2 is a perspective view of the processing apparatus incorporating the present invention;
FIG. 3 is a side view of the processing apparatus of FIG. 2;
FIG. 4 is a cross-sectional view of a feed hopper air-lock of the processing apparatus;
FIG. 5 is a cross-section view of extraction chamber of the present invention;
FIG. 6A is a cross-sectional view of the extraction chamber of the present invention suspended within a transportable unit; and
FIG. 6B is a partial cross-section of the base of the chamber of FIG. 6 showing auger placement and constant load support system;
While the invention will be described in conjunction with an example embodiment, it will be understood that it is not intended to limit the invention to such embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, similar features in the drawings have been given similar reference numerals.
Many types of contaminated inert substrate materials, such as soil, sand, sludge, sediments, drilling muds and cuttings, spent activated carbon, wood, etc. can be successfully treated to remove mercury and all types of organic compounds such as hydrocarbons, PCB's, PCP's, PAH's, insecticides, herbicides, creosote, pesticides, dioxins, furans, and the process is found to be effective for a broad variety of such contaminants which are encountered in contaminated solid materials. While it is not possible to list every contaminant to which the presently claimed thermal separation process can be applied, examples of organic contaminants are as previously mentioned.
The present invention is a two-stage process. The first stage consists of using indirect heat transfer to volatilize contaminants from the substrate. This is referred to as the phase separation process. The second stage involves collecting and cooling the volatilized vapours/gases and condensing them into liquid form. The condensate is then separated into contaminant and water fractions. The two stage treatment process is shown schematically in FIG. 1 . The process of the present invention consists of four particular handling stages: feed handling; thermal phase separation within the extraction chamber; treated substrate handling; and vapour treatment and recovery.
Prior to treatment, the feedstock material is screened to remove rock cobbles and debris, and then deposited into a feed hopper. The material is preferably fed from a feed hopper into a lump breaker by a horizontal conveyer belt. From the lump breaker the feed material is discharged onto an inclined conveyer for delivery to the extraction chamber.
The material is discharged from the inclined conveyor to a small hopper, which directs the feed material to two parallel rotary paddle airlock valves. Upon passing through the airlock valves, the substrate drops into the extraction chamber and is moved through the extraction chamber by two parallel screw augers. As the material moves through the extraction chamber, it gathers heat which is supplied to the extraction chamber from burners located externally and underneath the extraction chamber. The substrate remains physically separated from the combustion system by the extraction chamber's steel alloy shell. The firebox derives its heat by combustion of commercially available fuels and can be varied so that the temperature of the contaminated substrate material is elevated to the point that the contaminants in the material are volatilized. The treated substrate is then passed through a rotary airlock value at the end of the extraction chamber and is ready for re-wetting and re-introducing to the environment. The volatilized contaminants are fed from the combustion chamber to a vapour condensation and treatment system.
The volatilized water and contaminants generated in the extraction chamber are subject to a vapour/gas condensation and clean-up system for the purpose of collection and recovery of the contaminants in liquid form. The vapour/gas condensation and clean-up system preferably consists of six sequential treatment steps. Firstly, the hot volatilized vapours/gases from the extraction chamber are cooled through direct contact water sprays in a quench header and the water acquired by the quenching process is provided by spray nozzles spaced at regular intervals along the quench header. Secondly, the vapour/gas stream is then directed through one or more knock-out pots to remove residual particulate matter and large water droplets, preferably down to approximately 0.3 microns. Thirdly, the vapour/stream is preferably further cooled to a temperature less than 10° C. above ambient temperature by a cooling fan. Fourthly, the relatively dry gas stream of non-condensable gases is subjected to one or more mist eliminators for aerosol removal. Next, the gas stream is passed through a High Efficiency Air Filtration (HEAF) system to remove any submicron mists or particles still remaining in the stream. Glass media is used in the filter system to filter material down as a Microlite and, as such, the filters remove liquid mist down to a 0.05 micron level. Finally, the gas stream is then subjected to a final polishing in a series of carbon absorption beds and returned to the burners or vented to atmosphere. The carbon beds are operated in series to provide maximum polishing of the air stream.
Tables 1 and 2 provide a summary of the soil remediation results achieved by the process of the present invention with respect to a variety of locations and contaminants.
An embodiment of the invention is shown in FIG. 2 . It consists of processing apparatus 10 having a firebox shell 11 and emergency exhaust stack 12 . At a first end of the apparatus 10 there are in feed chute 14 a and 14 b , each of which is respectively connected to input rotary airlock valves 16 and 16 b . Below the chutes 14 a and 14 b there are first and second screw drives 18 a and 18 b . At the second end of the apparatus 10 there is an output rotary airlock valve 24 . The processing apparatus 10 is preferably mounted on support bed which has a plurality of support legs 22 mounted on a trailer with wheels.
The interior of the apparatus 10 is best seen in FIGS. 6 and 6A. Processing chamber 40 is suspended within the firebox shell 11 . Preferably, the chamber is suspended in place using a cross-beam support 42 suspended from load members 44 . In this manner the entire processing apparatus 10 can be mounted within the interior of a standard vehicle trailer 46 . In this manner extraction chamber is supported inside the firebox 11 through a constant load support system means which supports the chamber 40 in a manner allowing for thermal expansion caused by temperature variations throughout the extraction chamber. The supports 44 , as seen in FIG. 6, suspend the extraction chamber and provide a constant upward force of the chamber to counter downward forces caused by the weight of soil as the processing rate and steel temperature varies, thereby varying the downward force on the chamber, the support system automatically adjusts to provide the appropriate counter force. The method of support reduces the overall physical stress applied to the extraction chamber.
The constant load support system also allows the extraction chamber to grow longitudinally without having to overcome frictional forces. The longitudinal growth occurs as a result of thermal expansion caused by the temperature gradients of the chamber surfaces. This is achieved by pivoting the support structure to allow the system to swing as the chamber expands and contracts. The elimination of frictional forces also greatly reduces the localized stresses.
Chamber 40 has a generally “kidney shaped” profile in cross-section and, as such has two parallel troughs 48 a and 48 b each fitted with augers 52 a and 52 b . The trough of the chamber commence at the first end of the apparatus 10 , immediately below the input rotary airlock valves 16 a and 16 b , and terminate at the second end of the apparatus 10 , immediately above output rotary airlock valve 24 .
Contaminated substrate is delivered to a feed hopper and is preconditioned to improve processability of the feed, for example by the removal of stones, etc. Where necessary, the material may also be pulverized, again to increase process ability. The amount of preconditioning depends upon, whether the feed material is wet or dry. If the feed is a wet sludge, preconditioning may involve adding detackifiers such as dried processed air fluent solids or sand in with the feed in the feed hopper, or by the addition of ash or lime.
The contaminated substrate material passes, under gravity, through one of the rotary air locks 16 a or 16 b and into a corresponding trough 48 a or 48 b of the chamber 40 . Extraction chamber 40 which is surrounded by the firebox shell 11 within which a plurality of burners are located to heat the extraction chamber. Movement of the contaminated substrate through the extraction chamber is achieved by auger means 52 a and 52 b.
The extraction chamber is indirectly heated by means of externally located heaters, for example gas burners, in the firebox shell 11 . The burners heat the shell of the extraction chamber, and the heat is conducted by the metal shell of the extraction chamber to the interior of the chamber. The flights of the augers 48 a and 48 b also help in the heat transfer. The burners are controlled to supply sufficient heat to carry out the process at a desired rate. Preferably, sensors inside the extraction chamber measure the average temperature so as the maximum soils temperature is maintained at a desired level in the range of above 600° C. to 650° C. to maximize processing efficiency.
As the feed is exposed to thermal energy inside the extraction chamber, the volatile components are vapourized. The longer the feed remains in the chamber, the greater the degree of removal of the contamination of the substrate. Preferably, the processing temperature will be 125° C. to 175° C. above the boiling point of the contaminant.
In the preferred embodiment the base of the extraction chamber has a generally “kidney shaped” configuration, within which the two augers are located to move the contaminated substrate through the extraction chamber. In this manner, maximum processing of the contaminated substrate is achieved in view of the increased surface area of the materials within the chamber.
In a preferred embodiment, the extraction chamber is preferably 12 metres long and each trough in the bottom section of the chamber is preferably 0.62 metres in diameter with a wall thickness of 0.013 metres. The top section of the extraction chamber is preferably 1.47 metres in diameter with a wall thickness of 0.006 metres. The shape of the extraction chamber as shown in FIG. 6 maximizes heat transfer to the soil and other matrices and minimizes thermal expansion of the chamber. The use of two troughs in the extraction chamber decreases the soil bed thickness as it moves through the chamber in the troughs and thus allows for greater surface contact between the hot chamber steel and the contaminated substrate. The troughs are covered by a common roof to form a single chamber.
The unit shown in FIG. 6 can be mounted on standard 40 foot trailers. By being transportable, the treatment system can be transported to the treatment site and set up for processing. The capability to treat materials at the treatment site represents a significant economy in that the cost of transporting large amounts of inert contaminated substrate from the effected site to a treatment facility is eliminated.
Thus, it is apparent that there has been provided in accordance with the invention a METHOD AND APPARATUS FOR REMOVING MERCURY AND ORGANIC CONTAMINANTS FROM SOILS, SLUDGES AND SEDIMENTS AND OTHER INERT MATERIALS that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the invention.
TABLE 1
Summary of Previous TPS Remediation Results
Summary of Project Remediation Results
Treated
Feed Soil
Soil
Contaminant
Concen-
Concen-
Removal
and
tration
tration
Efficiency
Location
(mg/kg)
(mg/kg)
(%)
Drill Cuttings & Oil Base Muds
TPH
271,000
302
99.9
PAH Contaminated Soil
Total PAHs (Spiked Soil)
6,121
14.5
99.76
Total PAHs (Coquitlam, BC, Canada)
7,900
48.98
99.38
Total PAHs (Surrey, BC, Canada)
21,203
63.61
99.70
Total PAHs (Manitoba, Canada)
2,392
5.31
99.78
Carcinogenic PAHs
377.5
9.11
97.6
PCP Contaminated Soil
Total PCPs (Spiked Soil)
1,556
3.07
99.80
Total PCPs (Coquitlam, BC, Canada)
12
0.10
99.17
Total PCPs (Surrey, BC, Canada)
12
0.33
97.25
Total PCPs (Yukon, Canada)
47
0.59
98.74
Total PCPs (Manitoba, Canada)
124.7
0.70
99.44
PCB Contaminated Soil
PCB 1242 (Alberta, Canada)
521
1.71
99.67
PCB 1242 (Alberta, Canada)
352
5.99**
98.3%**
PCB 1260 (DESRT Testing)
169
>0.066
>99.96
PCB 1260 (Newfoundland, Canada)
175.2
0.24
99.86
Dioxin and Furan Contaminated Soil
Dioxins/Furans (TEQ)
209.8 ppt
<2.7 ppt
>98.7
(Newfoundland, Canada)
Dioxins/Furans (TEQ) (Alberta,
153 ppt
3 ppt
>80
Canada)
**Remediation criteria was 50 ppm.
TABLE 2
Typical Breakdown of PAH Analysis of Treated Soil
Removal
Inlet Soil
Treated Soil
Efficiency
PAH
(mg/kg)
(mg/kg)
(%)
Naphthalene
216.0
0.4199
99.81
Acenapthylene
77.2
1.2236
98.42
Acenaphthene
262.0
1.0679
99.59
Fluorene
87.6
0.4314
99.51
Phenanthrene
268.0
0.2073
99.92
Anthracene
189.2
0.2074
99.89
Fluoranthene
205.0
0.5711
99.72
Pyrene
117.0
0.5246
99.55
Benzo(a)anthracene
22.6
0.0597
99.74
Chrysene
59.0
0.0785
99.87
Benzo(b)fluoranthene
22.8
0.1812
99.21
Benzo(k)fluoranthene
9.6
0.0532
99.45
Benzo(a)pyrene
15.2
0.0519
99.66
Indeno(1,2,3-cd)pyrene
11.8
0.0771
99.35
Dibenzo(a,h)anthracene
14.5
0.1036
99.29
Benzo(g,h,I)perylene
11.7
0.0476
99.59
Total PAHs
2,392.4
5.301
99.78
Average
99.33
0.332
99.67
As shown in the previous tables, the invention has been successfully utilized to remediate soils contaminated with a variety of chlorinated and non-chlorinated hydrocarbons with typical removal efficiencies from the soil in excess of 99%. | An apparatus for thermally separating mercury and organic contaminants from inert substrate materials (such as soil, sludges, sediments, drilling muds and cuttings), comprising an essentially air-tight processing chamber having a substrate inlet and a substrate outlet, said chamber having two or more troughs for processing of the substrate, a means for indirectly heating the chamber, a means for moving substrate through the two or more throughs of the chamber from the substrate inlet to the substrate outlet, and a vapour condensate handling system for removing and condensing vapours from the chamber for processing to remove and recover contaminants. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to an anesthesia breathing circuit and respiratory care apparatus which may be used as a semi-open supply system and functions to simplify the use of the system. Numerous safety features are included as part of the system, which safety features may be used individually or in combination.
BRIEF DESCRIPTION OF THE PRIOR ART
Generally, the practice of administering anesthesia by inhalation includes two types of breathing systems. In the first, the circle carbon dioxide absorption system (semi-closed), unidirectional valving assures one-way flow of exhaled carbon dioxide and anesthesia gases through a carbon dioxide chemical absorption canister. The one-way flow prevents the rebreathing of exhaled carbon dioxide. In the second type of breathing system, a semi-open breathing circuit, a carbon dioxide absorption canister is not employed. The flow of anesthesia gases is used to remove exhaled carbon dioxide by venting exhaust gases to atmosphere. Semi-open systems have more or less universally been used either with non-rebreathing valving or have employed excessively high flow rates for incoming anesthesia gases to eliminate carbon dioxide from the breathing circuit. Prior to U.S. Pat. No. 3,856,051, both systems used more than one free swinging breathing tube to deliver the fresh anesthesia gases to the patient, and remove exhaled gases away from the patient.
In U.S. Pat. No. 4,007,737, two concentrically oriented tubes are used for delivering both inhalation and exhalation lines to and from the patient. Again, as in the older circle systems, unidirectional valving is used to allow flow only in one direction and, therefore, a greater loss of heat and humidity in the tubing occurs. Exhaust gases are vented to atmosphere after spontaneous or controlled ventilation, causing contamination of the environment, a situation which has been shown to be unhealthful.
Recent studies indicate that an anesthesia breathing circuit becomes contaminated with bacteria from the patient during administration of an anesthetic. If a ventilator is connected to the circuit, it also becomes contaminated along with the bag mount or CO 2 canister unless a filter is placed between the inhalation breathing circuit and the rest of the system. U.S. Pat. No. 3,856,051 does not disclose a system adaptable to present filters and, therefore, requires removal and cleaning of the ventilator as well as the breathing circuit and bag mount to prevent cross-contamination between cases.
In both of the above cited patents, a certain amount of rebreathing of exhaled gases occurs. In U.S. Pat. No. 4,007,737, the expired CO 2 is removed from the exhaled gases using a carbon dioxide absorber. However, both patents lack a convenient method of directly (in the circuit) determining the patient's mixed expired carbon dioxide tension. If a carbon dioxide canister (absorber) is used, then the patient's carbon dioxide is absorbed by the canister's soda lime, and is not available for mixing. If the exhaled gases are vented as in U.S. Pat. No. 3,856,051, then there is no method or opportunity for convenient measurement of carbon dioxide content.
Maintenance of near normal arterial carbon dioxide tension (normocapnia) during anesthesia is essential if the patient is to maintain near normal pulmonary ventilation to arterial perfusion ratios and normal cardiac outputs. As ventilatory tidal volumes are increased in order to prevent micropulmonary collapse during anesthesia with controlled volume ventilation, the amount of carbon dioxide removed from the patient varies in either of the previously mentioned anesthesia systems if mixed expired gases are not continuously analyzed for CO 2 and adjustments made. The only method available with the aforementioned patentd systems for determining the status of the patient's arterial CO 2 tension is by drawing a blood gas sample. This procedure carries certain risks, such as loss of a thumb or finger, and the results are delayed due to transport to and from the laboratory. Increased ventilation has caused patients to become seriously hypocapnic and has depleted the normal carbon dioxide level in their bodies. This hypocapnia has attendant dilatory effects on the pulmonary and cardiac performance. Also, large amounts of exhaled humidity and heat are lost from the anesthesia circuits. U.S. Pat. No. 4,007,737 claims to aid in the conservation of humidity by the exhalation tube enclosing the colder anesthesia inflow tube. Water content of delivered anesthesia gases is infinitesimally small. Also, placement of an exhalation unidirectional valve so close to the patent's breathing passage makes immediate rebreathing of a portion of the exhaled gases almost impossible. By the time the exhaled gases have returned from a more distant portion of the breathing circuit through the carbon dioxide absorbing canister, all humidity and heat have essentially been lost.
Control of the patient's vital functions during anesthesia and administration of gases should be accomplished with monitoring apparatus, anesthesia circuits, and breathing circuits, having as few moving (nd therefore potential malfunctioning) parts as possible. Concerning oxygen delivery, this can be monitored and controlled by oxygen analyzers in the gas delivery system to help avoid administration of hypoxic gas mixtures. Ventilation can be monitored by ventilator spirometers, ventilatory force pressure manometers, and end tidal carbon dioxide analyzers, either individually or in combination. The present invention shows that control can also be achieved during on-line monitoring of mixed expired CO 2 by using this value to make paired changes in inspiratory anesthesia gas/oxygen inflow rates and ventilating volumes during administration of gases.
Robert L. Rayburn, one of the co-inventers herein, recently demonstrated that since carbon dixoide production is related to body surface area, by (1) mechanically controlled anesthesia ventilation, and (2) pairing of anesthesia gas inflow with volume of ventilation, exhaled carbon dioxide concentration and arterial carbon dixoide tension can be controlled. Research with controlled partial rebreathing anesthesia techniques using a semi-open system allowed Rayburn to derive a fresh gas flow constant related to body surface area. By using three times the fresh gas flow constant for the minute ventilation delivered by mechanical anesthesia ventilator, a nearly normocapnic state in all individuals regardless of size and age was achieved. Since continuous mixing occurs, the arterial carbon dioxide tension was demonstrated to closely approximate the mixed expired carbon dioxide tension in the breathing circuit. Continuous control of the arterial carbon dioxide tension was best achieved with an in-line carbon dioxide analyzer measuring mixed expired CO 2 tension because, during anesthesia, ventilation may be changed or CO 2 production and elimination may vary, due to changes produced by surgery, anesthetics, patient's temperature, metabolism, etc. By present blood gas analysis, changes in arterial CO 2 must first be suspected, then a blood sample drawn, sent to the lab, a report returned, and then the correction in anesthesia fresh gas flow made. Then another sample must be drawn to assure that the correction is satisfactory. Whereas by means of an in-line CO 2 analyzer, variance of CO 2 tension and corrections of these variances may be continuously monitored.
There have been numerous incidences reported in medical journals of accidental overpressurization in semi-open and semi-closed circuits due to inadvertent closure of exhalation or pressure relief valves. This is a very dangerous situation which may cause the death of a patient. No present anesthesia system has an automatic pressure relief system and/or alarm. The present invention has an adjustable pressure relief governor with an audible alarm in addition to a combination pressure relief and scavenging valve. The adjustability of the pressure relief governor allows a lower maximum pressure to be set in the case of children versus adults, thus decreasing the risk of pneumothorax and death occuring from accidental overpressurization.
Anesthesia machines in the past have been designed with fail-safe regulators in case of loss of oxygen pressure. Recently oxygen sensors and analyzers have been used to monitor inspired O 2 and avoid hypoxia; however, hypoxia occuring due to system disconnects cannot be quickly diagnosed by the slow reacting oxygen analyzer. The present invention, in addition to incorporating an oxygen sensor and analyzer, incorporates a carbon dioxide analyzer with an appropriate carbon dioxide sensor (electrode). The carbon dioxide analyzer, which gives almost instantaneous results, has adjustable high and low carbon dioxide alarms so that an early warning of a circuit disconnection from a patient is given.
Previous carbon dioxide analyzing systems have been cumbersome and utilize analyzers that do not form a part of the circuit. Until recently, only end tidal CO 2 had been shown to correlate with arterial CO 2 tension. During anesthesia, measurement of end tidal CO 2 had not generally been used due to the complexity of the equipment and difficulty of obtaining samples at the patient's mouth during certain surgical procedures. If end tidal CO 2 is measured in semi-open circuits during partial rebreathing, of which the invention is an example, no correlation with arterial CO 2 exists. In addition, a portion of the mixed expired gases from the circuit would have to be withdrawn into the infrared analyzing chambers which, especially during pediatric anesthesia, would deplete the system of anesthetic volume. The present carbon dioxide analyzer works well on semi-open circuits, is small and portable, and forms a convenient part of the circuit thereby causing no loss of ventilating volume or change in anesthesia gas concentration.
SUMMARY OF THE INVENTION
The present invention is directed towards a controllable partial rebreathing anesthesia system and respiratory assist device having a control module connected through a breathing circuit to the patient. An exhalation and rebreathing tube forms a part of the system, which may be disposable or resterilizable, as well as a bacterial filter that may be connected thereto which filters contaminated exhaled gases. The inhalation rebreathing circuit may be connected to a transparent plastic control module. An oxygen sensor, carbon dioxide sensor, pressure relief governor, ventilator force manometer, exhalation and scavenging valve, and anesthesia reservoir bag or mechanical anesthesia ventilator may be connected to the control module for greater safety and efficiency. The patient's ventilation is monitored and the patient's carbon dioxide state is continuously determined by the carbon dioxide sensor, therefore allowing lower fresh gas flows to be used safely. This insures greater rebreathing of mixed expired gases. The greater rebreathing improves heating and humidification of the inspired gases which is not obtained by prior systems. The carbon dioxide analyzer aids both in the control of ventilation and in diagnosing abnormal patient carbon dioxide states. The inhalation breathing circuit by virtue of its adaptability to resuscitative equipment can be disconnected from the control module and used in the transporation of patients requiring supplemental oxygen, ventilation, end-expired pressure breathing, and tracheal suctioning.
For greater safety, a non-kinking corrugated tube, which may be disposable or resterilizable, is used as the fresh gas flow line and is connected to the anesthesia machine flow tube externally where the integrity of the connection can be visually seen to avoid undetected disconnection. In addition, the fresh gas is delivered at the patient end in a radial fashion at right angles to both the patient and the fresh gas and exhalation tubes. Such a delivery not only conserves the exhaled humidity by giving a cool circumferential screen of gas into which the patient exhales thereby causing a condensing of humidity at the patient end, but prevents venturi gas flows which create a vacuum in the exhalation tube and may be dangerous in certain patients.
The present invention attempts to prevent bacterial contamination of the control module and ventilator with exhaled gases by allowing use of an anesthesia bacterial filter at the connection of the exhalation tube and the control module.
The control module is small and lightweight aiding in its transportability. All external parts may be removed, and the plastic module and the component parts sterilized. All of the component parts of the control module can be externally visualized due to the transparent plastic from which the control module is made. A control valve that may be externally adjusted is connected to the control module to allow a graduated venting of the exhaled gases and scavenging thereof. The exhalation/scavenging valve is located immediately adjacent to the ventilating reservoir bag for ease of operation.
The inhalation breathing circuit is designed so that it may be removed from the control module, and an exhaust control valve and/or anesthesia reservoir bag may be connected to the filter end. The circuit may be used with a transport oxygen tank for transportation of the patient from one location to another. During transportation, positive end expiratory pressure can be maintained (via adaptability to a Carden valve), which is critical when transporting small children who have been on artifical respiratory devices to provide end expiratory pressurization.
An endotracheal tube elbow adapter is provided with a stoppered and sealed evacuation portal, the top of which may be removed to allow tight fitting suction tubes and/or flexible bronchoscopes to pass into the endotracheal tube and trachea for diagnosis and/or removal of secretions while maintaining volumetric pressure and oxygenation of the system.
The carbon dioxide analyzer includes an electrode inserted in the control module to measure the carbon dioxide tension and give an electrode signal proportionate thereto. The electrode signal is then converted in an analyzer circuit to a control signal that is inversely related to fresh gas flow, including an adjustment factor to account for normal variations between carbon dioxide tension in the patient and that of the control module. By adjusting the fresh gas flow, a reciprocal change in the carbon dioxide tension is demonstrated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a control module with some attachments.
FIG. 2 is an elevated side view of the present invention being used with an anesthesia ventilator and anesthesia machine.
FIG. 3 is an exploded perspective view of a respiratory assist device.
FIG. 4 is an elevated side view of the present invention being used with an adjustable exhalation/scavenging valve and an anesthesia reservoir bag.
FIG. 5 is a cross-sectional view of FIG. 3 taken along section lines 5--5.
FIG. 6 is a cross-sectional view of the control module shown in FIG. 1 taken along section lines 6--6.
FIG. 7 is a schematic block diagram of an analyzer circuit for the CO 2 electrode.
FIG. 8 is a cross-sectional view of FIG. 5 taken along section lines 8--8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawings, a control module designed by reference numeral 10 is shown. The control module 10 is one of the major components of the hereinafter described control partial rebreathing anesthesia system or circuit. While the control module 10 may be made from any suitable substance, in this preferred embodiment, the control module 10 is made from a clear heavy-duty plastic wherein internal portions are clearly visible.
The control module 10 has a number of items that may be connected thereto. The exhaled or expired gases normally feed into the control module 10 through flanged opening 12. Exhaled or expired gases received inside of the control module 10 may be regulated or monitored therein. A pressure gauge 14 with a pressure indicator 16 connects to the control module 10 through opening 18 to continually monitor the pressure inside control module 10. A pressure relief governor/alarm valve 20 is connected through opening 22 to the control module 10 to prevent and warn of overpressurization. An audible alarm and relief of pressure is given by the pressure relief governor/alarm valve 20 when the maximum pressure set for the control module 10 has been exceeded.
The expired gases received by the control module 10 are also monitored by an oxygen sensor 24 which connects to the control module 10 through opening 26. Also, a carbon dioxide electrode is inserted inside of elongated housing 28 which is in turn inserted in opening 30 of the control module 10. The carbon dioxide electrode (not shown in FIG. 1) is held inside of the elongated housing 28 by means of stopper 32. For calibration of the carbon dioxide electrode as will be explained in more detail subsequently, an auxiliary conduit 34 connects by one end thereof to the inside of the elongated housing 28. The opposite end of the auxiliary conduit 34 is normally covered by cap 36 after calibration has been completed.
Mounting flange 38 may be connected to an anesthesia reservoir bag or ventilator tubing leading to and from an anesthesia mechanical ventilator 86. Opening 40 receives an exhalation/scavenger valve 42 therein. By means of stem 44, the exhalation/scavenger valve 42 may be closed, partially opened, or fully opened. Operation of the exhalation/scavenger valve 42 will be explained in more detail subsequently.
The control module 10 may have a mounting fixture 46 either removably or permanently connected thereto by any suitable means. In this preferred embodiment, the mounting fixture 46 is formed as part of the control module 10 for connecting the control module 10 to a standard anesthesia machine mounting pole 49 by means of a pivot axis 48. Connecting bar 51 pivotally connects the pivot axis 48 to the mounting pole 49.
Referring now to FIG. 6 of the drawings, a cross-sectional view of the previously described control module 10 is shown. As can be seen in FIG. 6, the openings 26 and 18 have threads therein for receiving the oxygen sensor 24 and pressure guage (also called manometer) 14 therein, respectively. The oxygen sensor 24 is connected to a suitable oxygen analyzer by means of electrical connection 50. A typical oxygen sensor 24 with appropriate analyzer is manufactured by BioMarine Industries located in Devon, Pennsylvania, and commonly referred to as "Oxygen Analyzer 202R". Other types of oxygen analyzers are also commercially available.
The pressure relief governor/alarm valve 20 has a reed alarm 52 to give an audible alarm if pressurized gases flow around the valve element 54. Flange 56 of the read alarm 52 is securely received inside a flange 58 for a tight connection therewith. The pressure level at which the valve element 54 of the pressure relief governor/alarm valve 20 will allow gas to flow therethrough, which is continuously indicated by the pressure indicator 16 of pressure gauge 14, can be adjusted by removing the reed alarm 52 and adjusting nut 60 of the valve element 54. Naturally, pressure levels for a small child should be set for a lower value than pressure levels for an adult.
The exhalation/scavenger valve 42 has an adjustable valve element 62 with stem 44 threadably connected inside of valve body 64. The adjustment of the stem 44 opens and closes the valve seal 66. Exhaled or expired gases from a patient that flow through the exhalation/scavenger valve 42 also flow through mating flanges 68 and 70 into collecting cap 72. The collecting cap 72 has a graduated venting tube 74 with radial openings 76 located therein. A large reservoir tube may be connected to the large diameter portion 75 of the graduated venting tube 74. A vacuum line is normally connected to the small diameter portion 77 of the graduated venting tube 74. By having the radial openings 76 inside of the large reservoir tube helps prevent the vacumm line from decreasing the pressure inside of the control module 10 below a predetermined level as will be subsequently explained.
Referring now to the elongated housing 28 in opening 30 as shown in FIG. 6, the CO 2 electrode 78 is pictorially shown therein. In normal operation, the CO 2 electrode 78 is shoved inside of elongated housing 28 until stopper 32 seals with the end thereof. Thereafter, cap 36 is removed and a predetermined percent CO 2 gas is connected through auxiliary conduit 34 to the elongated housing 28. The percentage of the CO 2 gas inside of housing 28 is sensed by the CO 2 electrode and transmitted to the CO 2 analyzer circuit (as will be described subsequently) through electrical connection 80. An adjustment is made in the analyzer circuit to give the correct, predetermined output indicating the correct carbon dioxide tension. This procedure may be repeated for a different percentage CO 2 gas to complete initial calibration of the CO 2 analyzer. After disconnection of the predetermined percentage CO 2 from the auxiliary conduit 34 and replacing cap 36, upon use of the CO 2 electrode 78 as part of an anesthesia breathing circuit, the exhaled gases received inside of the control module 10 will flow through radial openings 82 and end opening 84 to come in contact with the CO 2 electrode 78. The signal generated by the CO 2 electrode 78 is fed through electrical connection 80 to the analyzer circuit.
Referring now to FIG. 2 of the drawings, a complete anesthesia breathing circuit is shown wherein the control module 10 is connected to a mechanical ventilator 86 by means of ventilator delivery hose 88 connected to mounting flange 38. Also connected to the flanged opening 12 is an inhalation breathing circuit 90 and bacterial filter 92.
Referring to FIGS. 3 and 5 in conjunction with FIG. 2, the inhalation breathing circuit 90 will be explained in more detail. A bacterial filter 92 is connected to the flanged opening 12, which bacterial filter 92 allows air flow therethrough in either direction. The bacterial filter 92 may be received inside of large opening 96 of circuit connector 94, or may have an exhaust control valve 192 therebetween as will be explained subsequently. Circuit connector 94 has a small opening 98 which extends outward from its longitudinal axis at approximately 30°. The end of the circuit connector 94 opposite the bacterial filter 92 shown in FIG. 2 or opposite the exhaust control valve 192 shown in FIGS. 3 and 5 is received inside of a large corrugated plastic tube 100. A ridge 102 around the outer edge of the circuit connector 94 helps maintain the large corrugated plastic tube 100 thereon. Extending through the small opening 98 is a small corrugated plastic tube 104 which receives a fresh gas line adapter 106 in one end thereof. The fresh gas line adapter 106 has a passage 108 therethrough with a small diameter portion 110 being received inside of small corrugated plastic tube 104. When the fresh gas line adapter 106 is inserted inside of the small corrugated plastic tube 104, both of which are subsequently inserted inside of the small opening 98, compressed corrugations 112 are clearly visible to show a good connection between the fresh gas line adapter 106 and the small corrugated plastic tube 104. A bonding compound could be further applied if desired to insure a good connection between the small corrugated plastic tube 104 and the fresh gas line adapter 106.
The small corrugated plastic tube 104 extends inside of the large corrugated plastic tube 100 to an expiratory mixing tube connector 114. One end of the expiratory mixing tube connector 114 is received inside of large corrugated plastic tube 100. Ridge 116 around expiratory mixing tube connector 114 helps maintain a good airtight connection with the large corrugated plastic tube 100. Inside of the expiratory mixing tube connector 114 is a fresh gas flow line delivery adapter 118 which has radial flanges 120 resting against internal shoulder 122 of expiratory mixing tube connector 114. A center tube 124 of the delivery adapter 118 is connected to the small corrugated plastic tube 104 for receiving fresh gases therefrom. The connection may be secured by any suitable means, such as bonding. Fresh gases traveling through center tube 124 of the delivery adapter 118 are radially discharged from side ports 126. Additionally, an end port may be included in the delivery adapter 118. This insures a mixing of the fresh gas delivered through the small tube 104 with the expired/exhaled gases from the patient in the large corrugated plastic tube 100.
The expiratory mixing tube connector 114 connects to an elbow adapter 128. The elbow adapter 128 may connect to an endotracheal tube or a face mask of the patient. The elbow adapter 128 has a passage 130 therein which changes the direction of flow of the inhaled/exhaled gases by 90°. If the elbow adapter 128 is connected to an endotracheal tube located in a patient, suctioning or bronchoscopic observation of the patient's lungs may be necessary. By removing plug 132 from upper opening 134, suctioning or bronchoscopic observation of the patient can be accomplished while other respiratory functions are being performed. By the proper sizing of the upper opening 132, an essentially airtight connection with the suctioning tube or bronchoscope is possible. The airtight connection further insures the performing of suctioning or bronchoscopic observation without loss of anesthesia and/or respiratory care functions. The plug 132 has a retaining ring 136 connected to elbow adapter 128 to insure that the plug 132 remains adjacent to upper opening 134 thereby preventing delays in opening or closure thereof.
Referring back to FIG. 2, assume that the elbow adapter 128 is connected to the endotracheal tube of a patient. The fresh gas line adapter 106 is also connected to fresh gas line 138. The fresh gas line 138 may be delivering gases and/or oxygen to the patient at a relatively low pressure. The fresh gas line 138 is connected through a metering valve 140 to a supply line control 142. Assuming that the mechanical ventilator 86 is being used, bellows 144 will be operating in an up and down manner.
As the patient breathes through the endotracheal tube connected to the elbow adapter 128, fresh gas is delivered through the side ports 126 of the delivery adapter 118 and is mixed with gases contained in the large corrugated plastic tube 100. Therefore, as the patient breathes in, not only will the patient receive fresh gas from the small tube 104, but will rebreathe a portion of the gases contained in the large tube 100. Flow of the gases through the small tube 104 is continually in the direction as indicated by the arrow. However, flow through the large tube 100 will be partially oscillatory with the general direction of movement of the gases therein as determined by the flow rate through the small tube 104 and will be toward the control module 10.
As the mixed expired gases are received in the control module 10, the expired gases will flow through radial opening 82 and end opening 84 into the elongated housing 28 containing the CO 2 electrode. The CO 2 electrode 78 will measure the carbon dioxide content of the mixed expired gases and send a control signal through electrical connection 80. Also, exhaled gases received in the control module 10 would flow in a general direction through ventilator delivery hose 88 into ventilator bellows 144. Motion of the bellows 144 in the ventilator chamber 146 allows the discharge of a portion of the expired gases therein out of discharge opening 148. The discharge opening 148 has a one-way valve located therein to insure one-way flow therethrough as indicated by the arrows. Another controllable portion of gases is discharged by the bellows 144 into the control module 10 via ventilator delivery hose 88 toward the patient for rebreathing through the large corrugated plastic tube 100.
In the system as shown in FIG. 2, the exhalation/scavenger valve 42 is closed. However, pressure manometer 14 continually monitors the pressure of the gas being delivered to the patient and pressure relief governor/alarm valve 20 is included for the patient's further safety. The pressure relief governor/alarm valve 20 is adjusted to a predetermined maximum pressure in the manner previously described. Simultaneously, oxygen sensor 24 generates an electric signal which represents the oxygen content of the mixed expired gases. Bacterial filter 92 helps insure that all expired gases that reach the control module 10 do not contaminate the control module 10 with the patient's bacteria, and any bacteria in the control module 10 will not be transmitted to the patient.
By use of the system as described in FIG. 2, each time the patient inhales, a portion of the gas inhaled by the patient is received from the fresh gas line 138 and a portion will be received from the large tube 100. The amount of fresh gases breathed during each inhalation is regulated by the flow through the fresh gas flow line 138. The amount of oxygen delivered to the patient can be accurately controlled by adjusting metering valve 140. The patient will rebreathe only a portion of the exhaled gases during each breath.
Referring now to FIG. 4 of the drawings, the control module 10 is shown in an alternative connection. The inhalation breathing circuit 90 is again connected to either a face mask or an endotracheal tube by means of the elbow adapter 128. Again, the small tube is received inside of the large tube 100 as previously described through the fresh gas line adapter 106 and circuit connector 94. Fresh gas, which may include anesthesia gases and/or oxygen, is again supplied through the fresh gas line 138, metering valve 140 and fresh gas supply line control 142. The bacterial filter 92 is located between the circuit connector 94 and mounting flange 12 of control module 10. The oxygen sensor 24 again analyzes the oxygen content of the mixed expired gases received in the control module 10, and the pressure gauge 14 monitors the pressure. The pressure relief governor/alarm valve 20 provides a maximum pressure limit for the exhaled gases inside of control module 10. If the pressure inside of the control module 10 exceeds the pressure set in the pressure relief governor/alarm valve 20, the pressure will automatically be relieved and an audible alarm will be given. Changes in the anesthesia breathing circuit as shown in FIG. 4 include the elimination of elongated housing 28 so that the CO 2 electrode 78 is inserted directly into the control module 10. A tight seal between the CO 2 electrode 78 and the opening 30 prevents the escape of mixed expired gases from the control module 10.
Mounting flange 38 has an anesthesia reservoir bag 152 connected thereto into which monitored mixed expired gases flow bidirectionally from control module 10 to reservoir bag 152. Movement of mixed expired gases from the reservoir bag 152 may be either spontaneous in the breathing patient or assisted/controlled by manual compression of the reservoir bag 152 in the respiratorally depressed or paralyzed patient. In either condition, a portion of the mixed expired gases is either drawn or forced during inspiration in the direction of the patient sequentially through flange 38 into control module 10, through flange 12, through filter 92 and finally through inhalation breathing circuit 90 to the patient. Normally, the overflow expired gases flow from the control module 10 via exhalation/scavenger valve 42. The amount of flow through exhalation/scavenger valve 42 is controlled by the adjustment of stem 44. By connection of a vacuum line 156 to the small portion of graduated venting tube 74, a vacuum is created inside of exhalation/scavenger valve 42 to remove expired gases from control module 10. To avoid creating excessive vacuum inside of the control module 10, the vacuum line 156 may draw air from a large vent/scavenger line 158 through openings 76. Also, the large vent/scavenger line 158 may be used without the vacuum line 156 to remove expired gases.
In operation, the circuit as shown in FIG. 4 supplies fresh gas and/or anesthesia gases to the patient via fresh gas line 138, small tube 104 and elbow adapter 128. By regulating the flow through the fresh gas line 138 by metering valve 140, the amount of expired gases that are rebreathed can be controlled. Again, expired gases, while having some oscillatory motion inside of large tube 100, generally flow through the bacterial filter 92 into the control module 10. The oxygen sensor 24 determines the oxygen content of the mixed expired gases and the pressure gauge 14 gives an accurate reading of the pressure inside of control module 10. The safety feature of the pressure relief governor/alarm valve 20 is again adjusted to the individual patient. The CO 2 electrode 78 continually monitors the carbon dioxide tension of the mixed expired gases. The amount of fresh gas delivered to the patient is regulated according to the reading received from the carbon dioxide electrode 78 in a manner as will be subsequently explained. By opening the exhalation/scavenger valve 42 by means of stem 44, exhaled gases are removed from the control module 10 either by vacuum line 156, by a large vent line 158, or by a combination of both.
The operation of the CO 2 electrode 78 as it is used to regulate the anesthesia breathing circuit will be explained in more detail herein in conjunction with FIG. 7. The CO 2 electrode 78 is a standard type that may be purchased commercially which has a semi-permeable membrane that will not allow liquids to penetrate, but gas, including exhaled carbon dioxide, will penetrate. Voltage developed across the CO 2 electrode 78 gives a very high impedance output of the order of 10 12 to 10 14 ohms. The connection from the CO 2 electrode 78 to an impedance converter 160 is shielded to prevent any outside interference. In fact, inside of the impedance converter 160 shielding is still used until the impedance of the signal from the CO 2 electrode 78 has been changed to a more usable form. Even the shielding is isolated to prevent the pickup of unwanted noise or interference. The impedance converter 160 may use different types of isolation devices, including field effect transistors, as a means for reducing the impedance of the signal down to a more usable form. Also, by having adjustable operational amplifiers as a part of the impedance converter 160, the circuit as shown in FIG. 7 can be calibrated. By immersing the CO 2 electrode 78 into a gas having a known value, a low calibration point of the impedance converter 60 is set by a first external adjustment thereto. Next, by immersing the CO 2 electrode 78 in a known gas of a higher carbon dioxide content, a high calibration for the impedance converter 160 is also set by a second external adjustment thereto.
An output signal from the CO 2 electrode 78 after being converted through the impedance converter 160 feeds to an analog function generator 162. The analog function generator 162 produces a nonlinear analog relationship between the input and output. The nonlinear analog relationship is necessary because the voltage developed by the CO 2 electrode 78 versus the tension of CO 2 is a logarithmic relationship. Therefore, it is necessary to generate an analog function thereby converting the signal received from the CO 2 electrode 78 through the impedance converter 160 to a generally linear relationship.
The output signal from the analog function generator 162 is fed to a scaling amplifier 164. The scaling amplifier 164 produces a signal of a more convenient size that may be used by the digital voltmeter 166. Also, the scaling amplifier 164 has an external adjustment that may be used to compensate for temperature and other variables as may exist between the carbon dioxide received in the control module 10 and the carbon dioxide tension as exists in the patient's bloodstream. This adjustment has been determined experimentally as will be described hereinafter.
The output signal from the digital voltmeter 166 is fed to a two digit light emitting diode display 168 that gives the CO 2 tension as measured by the CO 2 electrode 78. To insure that the CO 2 as measured by the CO 2 electrode 78 is within certain limits, a lower limit set switch 170 feeds a lower limit voltage level into lower limit comparator 172, which lower limit voltage level is representative of the minimum value of CO 2 that should exist in the control module 10 as measured by the CO 2 electrode 78. If the value being fed into the lower limit comparator 172 from the digital voltmeter 166 is less than the value being fed into the lower limit comparator 172 by the lower limit set switch 170, an output signal will feed through OR gate 174 to operate an audible alarm 176.
Likewise, the upper limit set switch 178 feeds a predetermined voltage level into upper limit comparator 180 that is representative of a maximum value of CO 2 that should exist in the control module 10 as measured by the CO 2 electrode 78. If the output for the digital voltmeter 166 exceeds the value set by the upper limit set switch 178 as fed into the upper limit comparator 180, the upper limit comparator 180 will feed an output signal through OR gate 174 to audible alarm 176. Naturally, the voltage levels of upper limit set switch 178 and lower limit set switches 170 may be varied according to the patient's changed conditions.
The circuit as just described in FIG. 7 is designed for operation off of a 24 volt rechargable battery 182. The power used to drive the electronics for the CO 2 analyzer circuit as shown in FIG. 7 is provided by the 24 volt battery 182 via voltage regulator 184. The output voltage from voltage regulator 184 provides power for the previously described components of FIG. 7. If the voltage for the 24 volt battery 182 drops below a predetermined level, battery condition monitor and alarm 186 will give an output signal indicating the charge of the 24 volt battery 182 has dropped below a predetermined level. An AC line operated battery charger 188 may be connected to the 24 volt battery 182 by means of a detachable cord 190. Once the 24 volt battery 182 is brought to a predetermined charge level, the AC line operated battery charger 188 is disconnected and removed.
In order to calibrate the CO 2 analyzer circuit shown in FIG. 7, the CO 2 electrode 78 is placed in a calibration chamber, such as elongated housing 28 or other suitable enclosure. Next, for example, a predetermined percent carbon dioxide gas (such as 5% CO 2 ) is connected to the calibration chamber. The low calibration of the impedance converter 160 is adjusted so that the two digit light emitting diode display 168 gives the proper readout. For instance, the proper readout on the two digit light emitting diode display 168 is "37", which is determined by multiplying 5% times the ambient barometric pressure (740 millimeters of mercury). The value 37 is equal to 37 millimeters of mercury or "37 torr". Next, by connecting a different value of CO 2 gas to a calibration chamber (such as 10% CO 2 ), the impedance converter 160 is adjusted through its high calibration. By multiplying 10% times the ambient barometric pressure, a reading of 74 millimeters of mercury should be shown on the display 168. The calibration as just described can also be performed when the CO 2 electrode 78 is inserted into the control module 10.
After the control module 10 has been flushed with a fresh gas and stabilized after connection to the patient, an additional calibration in the scaling amplifier 164 is necessary. It has been found through experimentation that for a normal adult, after the monitoring of the expired carbon dioxide inside of the control module 10 has stabilized, that a positive adjustment of approximately 5 millimeters of mercury must be made in the scaling amplifier 164 to properly reflect the carbon dioxide tension in the bloodstream of the patient. Therefore, if the patient after stabilization had an indication of 40 millimeters of mercury on display 168, the scaling amplifier 164 would be adjusted so that the display 168 would indicate 45 millimeters of mercury. This adjustment is probably necessary to compensate for the differences in temperature, as well as numerous other factors, and has been experimentally derived to more closely correlate the readout of the display 168 to the arterial blood carbon dioxide tension. This correlation is usually within a range of plus or minus 2 millimeters of mercury of the actual arterial carbon dioxide tension. The compensating factor, as adjusted into the scaling amplifier 164, adjusts the difference between the actual arterial carbon dioxide tension and that read by the CO 2 electrode 78 in the control module 10 of the breathing circuit.
By use of a breathing circuit having the control module 10 as previously described, a patient's carbon dioxide tension can be continuously monitored. As a patient's carbon dioxide tension increases, a change in the fresh gas flow to the patient will cause a reciprocal change in the carbon dioxide tension as indicated by the display 168. As a patient's expired carbon dioxide tension changes, it is sensed almost immediately by the carbon dioxide electrode 78.
The present anesthesia breathing circuit is designed so that it can be completely disassembled and reconnected according to the particular requirements. Each of the components of the anesthesia breathing system may be sterilized, including the control module 10. All of the components connected to the control module 10 can be quickly disconnected therefrom and individually sterilized, as well as the control module 10. The inhalation breathing circuit 90 may either be sterilized or discarded and replaced with a new circuit. The versatility of the controllable partial rebreathing circuit is its most desirable feature. When the control module 10 is used, the CO 2 electrode 78 and analyzer circuit becomes very important in continually maintaining a desirable carbon dioxide tension in the patient. Various safety features as associated with the control module 10 prevent accidental overpressurization of the patient, or creating of a vacuum that would prevent the delivery of fresh gases to the patient. These and many other features are incorporated as part of the anesthesia breathing circuits previously described and shown in conjunction with FIGS. 2 and 4.
In FIGS. 2 and 3, the inhalation breathing circuit 90 may be removed from the bacterial filter 92 and/or control module flange 12 and connected to a reservoir bag 152 with the exhaust control valve 192 interposed for providing continuous ventilatory support when transporting a patient from the operating theater to the surgical recovery area. The exhaust control valve 192 can be seen in more detail in the cross-sectional view of FIGS. 5 and 8. Passage 194 of the exhaust control valve 192 is in flow communication with passage 186 of circuit connector 94 and reservoir bag 152. One end of the exhaust control valve 192 is received in large opening 96 of the circuit connector 94, and the other end of control valve 192 is received in opening 198 of the reservoir bag 152. A wedge-shaped opening 200 is provided in the wall 202 of passage 194. Encircling wall 202 to cover wedge-shaped opening 200 is a ring 204. Radial stem 206 is connected to ring 204 and has an opening 208 extending therethrough. By adjustment of the ring 204, opening 208 overlaps with wedge-shaped opening 200 to allow expired gases to escape. The wedge-shaped feature of opening 200 allows for regulation of the expired gases.
A vacuum line can be connected to radial stem 206 to scavenge the mixed expired gases. Side ports 210 in radial stem 206 would prevent a vacuum from being created in the inhalation breathing circuit 90. Also, a bacterial filter 92 may be included as part of the inhalation breathing circuit 90.
By use of the inhalation breathing circuit 90, anesthesia reservoir bag 152, and/or exhaust control valve 192, a patient may be ventilated during transportation from one location to another while fresh gases are still being received through the small tube 104. The use of an anesthesia reservoir gag 152 is necessary on many occasions for short periods of time. If, during transportation of the patient, suctioning or observation with a fiberoptic bronchoscope is necessary, plug 132 may be removed and the suctioning tube or bronchoscope inserted through upper opening 132. By having a tight connection with upper opening 132, the normal ventilation of the patient can continue.
METHOD OF USING THE APPARATUS
Prior to anesthetizing a patient with the invention, the carbon dioxide analyzer control circuit shown in FIG. 7 is calibrated by placing the CO 2 electrode 78 in a calibration chamber or in the elongated housing 28. A predetermined percentage of carbon dioxide gas (calibration gas) is connected to the calibration chamber or elongated housing 28 through the auxiliary conduit 34. This is usually a low concentration gas (frequently 5% CO 2 ). The low calibration of the impedance converter 160 in FIG. 7 is adjusted to readout on the two digit light emitting diode display 168 the partial pressure of the carbon dioxide in the calibrating gas. This partial pressure is independently determined by multiplying 5% times the ambient barometric pressure (for example, 740 millimeters of mercury). No correction is necessary for water vapor since the gases are used dry. The resultant value of 37 millimeters of mercury or torr is set on the two digit light emitting diode display 168 using impedance converter 160.
Next, by connecting a different calibration carbon dioxide gas (such as 10% CO 2 ) to the calibration chamber or auxiliary conduit 34, the impedance converter 160 is adjusted through its high calibration observing the readout on the two digit light emitting diode display 168. This reading, attached by multiplying barometric pressure (740 millimeters of mercury) times 10% CO 2 should read 74 millimeters of mercury or torr. These steps may be rechecked to assure correct calibration.
At this point, using the scaling amplifier 164, the reading on the two digit light emitting diode 168 is advanced 5 millimeters of mercury or torr in the positive direction. That is to say, if the CO 2 analyzer has been calibrated and the reading on the two digit light emitting diode display is 74 (with 10% CO 2 gas in the calibration chamber), the scaling amplifier 164 is turned until the reading is now 79. This step is performed to compensate for an experimentally derived figure of approximately 5 torr, expressing the difference between arterial carbon dioxide tension and mixed expired carbon dioxide tension. This later step, using the scaling amplifier 164, may be performed with the CO 2 electrode 78 in the circuit provided the readings are relatively stable during calibration.
Once the CO 2 analyzer is calibrated and inserted into the control module 10, the entire circuit is pressurized by allowing fresh gas to flow into the circuit through fresh gas flow line 138. Also, the exhalation/scavenger valve 42 is closed, and the patient opening of the elbow adapter 128 is manually scaled. By observing the pressure reading on the pressure gauge 14, the pressure relief governor/alarm valve 20 may be set by adjusting nut 60 to relieve pressure in excess of a predetermined amount and provide an alarm.
With the CO 2 analyzer and pressure relief governor/alarm 20 calibrated, the O 2 analyzer with oxygen sensor 24 (if used) may be calibrated in the standard manner while inserted into the control module 10.
After inspecting the entire anesthesia circuit and anesthesia machine as is routinely done prior to administration of anesthesia, the anesthesia circuit is ready for use.
If administration of gases with the anesthesia circuit is accomplished according to the method previously described by Rayburn, the following calculations are usually made prior to the onset of administration of gases. Using the patient's height and weight determined in the usual manner, the patient's surface area as expressed in square meters is obtained from a nomogram or surface area calculator. Having obtained this surface area value, it is multiplied by an experimentally derived constant of 2500 ml/m 2 /min. The resultant value is the total fresh gas flow delivered through the fresh gas line 138 via metering valve 140, into the small tube 104 and hence into the entire anesthesia circuit. This fresh gas flow will maintain the arterial carbon dioxide tension at approximately 40 torr, provided minute ventilation is at least three (3) times the fresh gas flow. The minute ventilation, which may be provided using either a mechanical ventilator 86 or manual ventilation using a reservoir bag 152, may be provided by using any one of a number of combinations of respiratory rate and tidal volume relationships totalling a value three times the fresh gas flow. This is true provided the tidal volume is not decreased to a point that normal alveolar minute ventilation is not maintained. For example, using a 10 kilogram child whose surface area is 0.5 m 2 , the fresh gas flow rate delivered through fresh gas line 138 is 1250 ml/min. The minute ventilation is three times this value, or 3750 ml/min. The tidal volume delivered by the mechanical ventilator 86 or by manual ventilation using reservoir bag 152 to the patient's lungs through the distal aperture in expiratory mixing tube connector 114 is usually set at 15 ml/kg. The respiratory rate is then calculated by dividing the tidal volume into the minute ventilation (i.e. 3750 ml/min÷150 ml=25 breaths/min).
Having made these calculations, the patient may be connected to the controllable partial rebreathing anesthesia circuit for administration of gases, by any means deemed suitable for controlled ventilation. Fresh gas flow through fresh gas line 138 is set according to the above calculations using metering valve 140. The minute ventilation, either from the ventilator bellows 144 through ventilator delivery hose 88 into the circuit or from the reservoir bag 152, is set using the above calculations for minute ventilation. Under these conditions, after a short time for equilibration of patient and anesthesia circuit, the carbon dioxide analyzer should read on the two digit light emitting diode display 168, a number very near 40 torr, which correlates closely with the arterial blood gas carbon dioxide tension. If the number on the two digit light emitting diode display 168 is significantly larger than 40, an increase in the fresh gas flow through fresh gas line 138 is necessary in order to return the value on the two digit light emitting diode display 168 to approximately 40 torr, and assure normocapnia. If the number on the two digit light emitting diode display 168 is less than 40 torr, then less fresh gas flow is necessary. Using this method during administration of gases provides a constant monitoring of, and gives ability to change, arterial carbon dioxide tensions using a non-invasive technique.
Additional benefits derived during administration of gases by the above method centers around the greater mixing of gases and therefore, rebreathing of mixed gases. This provides greater heat and humidity retention with humidity in the large corrugated plastic tube 100 being rebreathed. The greater mixing of gases allows lower fresh gas flow than prior systems thereby providing greater economy of gases. In addition to monitoring mixed expired carbon dioxide tension in the control module 10, oxygen content and ventilating pressure are monitored using an oxygen sensor 24 and pressure gauge 14, respectively. The pressure relief governor/alarm valve 20, calibrated as described earlier, is available as a safety feature should the safe upper level of pressure be exceeded in the circuit. The exhalation/scavenger valve 42 may be used to remove and scavenge expired gases from the control module 10 when a ventilator is not being employed.
Usually the controllable partial rebreathing anesthesia circuit in pediatric patients is connected via the terminal port of the expiratory mixing tube connector 114. Use of the elbow adapter 128 in small patients may increase the arterial and mixed expired carbon dioxide tensions due to dead space. If the elbow adapter 128 is used in small patients, then a porportional increase in fresh gas flow over that calculated must be delivered through the fresh gas line 138 to maintain the carbon dioxide tension at 40 torr.
The inhalation breathing circuit 90 may be removed from the control module 10 and attached to the exhaust control valve 192 and reservoir bag 152 for delivery of gases by controlled or spontaneous ventilation. This may be used for transport of patients, respiratory care, resuscitation, or delivery of anesthetic gases. In the case of controlled ventilation, ventilation may be provided by opening and closing the exhaust control valve 192 in order to provide manual ventilation via reservoir bag 152. A bacterial filter 92 may be connected between the circuit connector 94 and the exhaust control valve 192. Fresh gas flow may be delivered through fresh gas line 138 to small tube 104 using the previously stated calculations provided minute ventilation is unchanged. This respiratory assist device is suitable generally for short procedures and those procedures involving spontaneous ventilation. | A method and apparatus for administering anesthesia to a patient is shown. A control module may be connected through an inhalation breathing circuit to a patient with a portion of the mixed/expired gases being rebreathed by the patient thus improving humidification and heat retention. By use of a CO 2 analyzer in the control module, the CO 2 content of the expired gas is accurately measured with any necessary adjustments being made in the gases delivered to the patient. The control module includes an O 2 analyzer, adjustable pressure warning and control device, pressure gauge, manually controlled scavenger valve, and bacterial filter connected thereto. An anesthesia ventilator or breathing bag may be used in conjunction with the control module for administering anesthesia or transportation of the patient. The inhalation breathing circuit has two concentric, non-kinking, corrugated tubes, one visually apparent within the other for delivering both fresh gas with a mixed portion of the expired gas to the patient through a special elbow adapter that allows suctioning without interrupting the fresh gas flow or ventilation of the patient. | 0 |
BACKGROUND
[0001] 1. Field of Invention
[0002] The present invention relates to a pretreatment method for the surface of steel T91/P91, especially to a pretreatment method for improving antioxidation of steel T91/P91 in high temperature (500-750° C.) water vapor.
[0003] 2. Description of Related Art
[0004] Currently, due to the excellent performance, the series ferritic steel containing 9-12% of Cr is applied to large-diameter P91 vapor pipes (main vapor pipes and reheat vapor pipes) and small-diameter T91 vapor pipes (superheater pipes and reheater pipes), which are used for thermal power generation. Compared with the conventional ferritic steel, such material has a better mechanical property and thus can be applied at a higher temperature and pressure, thereby improving the efficiency of thermal power generation. Currently, steel T91/P91 has become a common material used in the supercritical units of a power station boiler, due to relatively high tensile strength, high temperature creep and endurance strength, low thermal expansibility, excellent thermal conductivity, malleability and antioxidation capability, as well as high tenacity. However, the steel T91/P91 may still be seriously oxidized in high temperature and high pressure water vapor after being oxidized for a long time or when operating at a higher temperature.
[0005] In a water vapor atmosphere, at 500-750° C., the oxidation speed of the steel T91/P91 greatly increases as the temperature rises. The oxidation product of the steel T91/P91 comprises Fe 2 O 3 , Fe 3 O 4 and (Fe,Cr) 3 O 4 . Since such material contains low content of Cr, no continuous or compact Cr 2 O 3 layer is formed in oxide films generated at different temperatures, and even no Cr 2 O 3 phase is formed in the oxide films. In general, the oxidation product is in a form of (Fe,Cr) 3 O 4 solid solution. As the oxidation speed increases and the temperature changes, a thicker oxide film is subjected to larger growth stress and thermal stress, so the plastic deformation of the oxide film is limited. Thus, obvious oxide film stripping occurs in application of such materials, and in turn the oxide film stripping further increases the oxidation speed.
[0006] When the steel T91 and steel P91 are applied to a vapor pipe for thermal power generation, applying a coating on the inner wall or modifying the surface is one of efficient ways for improving the antioxidation of the steel T91 and steel P91 in the high temperature water vapor. However, the process for applying a coating/plating layer in a small-diameter vapor pipe is generally complicated, and in a simpler hot-dip aluminum plating process, due to the brittle phase of a Fe—Al intermetallic compound generated in the process, the plating layer is stripped during oxidation, and meanwhile, the mechanical property of the pipe is greatly influenced.
[0007] T. Sundararajan [T. Sundararajan, et al: Surface and Coatings Technology, 2006, 201, 2124.] detected the oxidation behavior of a sample in water vapor at 650° C. directly after nano-CeO 2 was coated on the surface of steel T91. The result indicates that the oxidation speed is lower than that of a blank sample. However, after being oxidized for 500 hours, the external layer of the oxide film is a ferric oxide, and the inner layer is a film composed of mixed oxides of Fe, Cr, and Si, whose antioxidation capability in water vapor is still limited.
[0008] Li Xingeng and Wang Xuegang [Li Xingeng, Wang Xuegang, et al: Corrosion Science and Protection Technology, 2008, 20(3) 157-161.] researched the oxidation behavior of a CeO 2 film deposited on the surface a Fe—Cr alloy containing 9%. of Cr in the water vapor at 600-770° C. The result indicates that the deposited rare earth thin film neither changes the structure of the oxide film nor obviously reduces the oxidation speed.
SUMMARY
[0009] The present invention aims to overcome the shortcomings of the prior art and provides a pretreatment method for improving antioxidation of steel T91/P91 in high temperature water vapor. The method has the advantages that the process is simple, the cost is low, the practicability is strong, the service life is long, the antioxidation capability in high temperature water vapor is excellent, an oxide film rich in chromium oxide can be formed on the surface of steel T91/P91 , etc.
[0010] To achieve the purpose mentioned above, the following technical scheme is adopted in the present invention:
[0011] A pretreatment method for improving antioxidation of steel T91/P91 in high temperature water vapor includes the following steps:
[0012] 1) preparing a slurry: adding 0.5-35 wt % of aluminum powder and 65-99.5 wt % of rare earth oxide into a sodium silicate aqueous solution with modulus of 2.4-2.9 and density of 1.1-1.5 g/cm 3 , and then stirring evenly to prepare the slurry;
[0013] 2) coating the slurry prepared in step 1) on the surface of steel T91/P91;
[0014] 3) drying: drying the steel T91/P91 coated in step 2) in an oven at 10-30° C. for 1-4 hours, and then drying at 70-100° C. for 1-4 hours;
[0015] 4) carrying out heat preservation on the steel T91/P91 dried in step 3) in an atmosphere furnace charged with a gas mixture of inert gas and water vapor at the temperature of 600-800° C. for 24-48 hours; and then powering off the atmosphere furnace and naturally cooling the steel T91/P91 to room temperature in the furnace;
[0016] 5) cleaning away the powder attached to the surface of the steel T91/P91 to obtain the steel T91/P91 with a surface containing chromium and rare earth oxide.
[0017] In preparation of the slurry in steps 1) and 2), the ratio of the sodium silicate aqueous solution to solid components composed of aluminum powder /and rare earth oxide is 10-60 ml sodium silicate aqueous solution per 100 g solid components.
[0018] The rare earth oxide has purity equal to or larger than 99.00% and granularity equal to or less than 30 μm; and the aluminum powder has purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0019] The rare earth oxide is Y 2 O 3 or La 2 O 3 . In step 2), the slurry is coated in a manual brush coating or dip coating manner, or the slurry is naturally attached to the inner wall of a T91/P91 steel pipe after being injected into the steel pipe.
[0020] In step 4), the gas mixture of inert gas and water vapor comprises 60-95 vol % of inert gas and 5-40 vol % of water vapor.
[0021] The inert gas is argon with purity equal to or larger than 99.99% or helium with purity equal to or larger than 99.99%.
[0022] In step 5), the powder attached to the surface of steel T91/P91 is cleaned away by washing with distilled water.
[0023] The steel T91/P91 is used in an environment at a temperature of 500-750° C. with 5-40 vol % of water vapor.
[0024] The present invention has the following advantages:
[0025] 1. The pretreated steel T91/P91 in the present invention has excellent antioxidation capability in high temperature water vapor, which can greatly reduce the oxidation speed of such materials in a water vapor atmosphere. After isothermally oxidized in the 700° C. water vapor environment for 600 hours, a blank sample has an oxidation mass gain of 16.51 mg/cm 2 , while the surface-modified sample only has an oxidation mass gain of 0.15 mg/cm 2 . The oxidation mass gain of the surface-modified sample is less than 1/100 of that of the blank sample, and meanwhile, no surface cracking or oxide-film stripping is found on the surface of the surface-modified sample.
[0026] 2. In the present invention, the steel T91/P91 is treated with a rare earth containing mixture and then treated with a gas mixture of high temperature water vapor and inert gas to obtain a surface rich in chromium and having a small amount of rare earth oxide. The preparation process is simple, needs no vacuum conditions and has low cost.
[0027] 3. After the sample is pretreated, the solid powder left on the surface is cleaned away by washing with distilled water, and the surface treatment does not change the surface roughness of the sample.
[0028] 4. By using the present invention, the inner wall of a small-diameter pipe can be treated and the method of the present invention has wide applications. By applying the present invention, the antioxidation capability of steel T91 and steel P91 in a high temperature water vapor environment can be improved.
[0029] 5. The coating process of the present invention is simple, which can be performed in a manual brush coating or dip coating manner, or the slurry with an adjusted viscosity is naturally attached to the inner wall of a T91/P91 steel pipe after being injected into the steel pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 illustrates the surface topography of steel T91 treated with a rare earth containing mixture according to the present invention;
[0031] FIG. 2 illustrates an energy dispersion spectroscopy (EDS) of the steel T91 treated with a rare earth containing mixture according to the present invention; and
[0032] FIG. 3 illustrates the cross-section topography of the steel T91 pretreated and oxidized in water vapor at 700° C. for 600 hours according to the present invention.
DETAILED DESCRIPTION
[0033] The present invention is further described below with reference to the accompanying drawings and embodiments.
[0034] Embodiment 1: the solid powder mixture is composed of: yttrium oxide (Y 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 pm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0035] The slurry is prepared by firstly adding 100 g solid powder mixture of 99.5 wt % of Y 2 O 3 powder and 0.5 wt % of aluminum powder into 30 ml sodium silicate aqueous solution with modulus of 2.4-2.9 and density of 1.1 g/cm 3 , and then stirring evenly to prepare the slurry.
[0036] The detailed data of this embodiment is as follows: the dimension of a T91 steel sample is 10×15×3 mm; and the slurry prepared through the abovementioned method is applied to the surface of the T91 steel sample in a dip coating manner, and then after dried in an oven at 30° C. for 2 hours, the T91 steel sample is dried in the oven at 100° C. for 1 hour. The dried steel T91 is put into an atmosphere furnace charged with a gas mixture of 90 vol % of argon (the purity is equal to or larger than 99.99%) and 10 vol % of water vapor mixture at a heating temperature of 720° C. for 48 hours; thereafter, the atmosphere furnace is powered off and the steel T91 is naturally cooled to room temperature in the furnace. The sample is taken out after cooled to room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface rich in chromium and having a small amount of rare earth oxide.
[0037] The steel T91 is used in an environment at a temperature of 500° C. with 5 vol % of water vapor.
[0038] FIG. 1 illustrates the surface topography and EDS of the steel T91 treated by the abovementioned process. The surface of the treated sample is rich in chromium and has a small amount of Y. After the pretreatment, the polishing scratches on the surface of the sample can be still observed through a scanning electron microscope (SEM), which indicates that the treatment does not change the surface roughness of the sample, and the surface of the treated sample is slightly shrimp pink. After the pretreatment, the sample is isothermally oxidized in a 700° C. water vapor environment for 600 hours, and finally only has an oxidation mass gain of 0.15 mg/cm 2 . The surface of the sample is basically not obviously oxidized, with no oxide film stripping on the surface, and thus the antistrip performance of the sample is greatly improved, as shown in FIG. 3 . A complete and continuous oxide film rich in chromium oxide and having an excellent binding force is formed through an oxidation process, and the oxide film has a thickness of about 1 pm, as shown in FIG. 2 .
[0039] Embodiment 2: the solid powder mixture is composed of: yttrium oxide (Y 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 μm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0040] The slurry is prepared by firstly adding 100 g solid powder mixture of 85 wt % of Y 2 O 3 powder and 15 wt % of aluminum powder into 10 ml sodium silicate aqueous solution with modulus of 2.6 and density of 1.3 g/cm 3 , and then stirring evenly to prepare the slurry.
[0041] The detailed data of this embodiment is as follows: the dimension of a P91 steel sample is 10×15×3 mm; and the slurry prepared through the abovementioned method is coated on the surface of the P91 steel sample in a dip coating manner, and then after dried in an oven at 10° C. for 4 hours, the P91 steel sample is dried in the oven at 70° C. for 4 hours. The dried steel P91 is put into an atmosphere furnace charged with a gas mixture of 95 vol % of argon (the purity is equal to or larger than 99.99%) and 5 vol % of water vapor at a heating temperature of 600° C. for 45 hours; thereafter, the atmosphere furnace is powered off and the steel P91 is naturally cooled to room temperature in the furnace. The sample is taken out after cooled to room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface rich in chromium and having a small amount of rare earth oxide.
[0042] The steel P91 is used in an environment at a temperature of 600° C. with 25 vol % of water vapor.
[0043] Embodiment 3: the solid powder mixture is composed of: yttrium oxide (Y 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 μm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0044] The slurry is prepared by firstly adding 100 g solid powder mixture of 65 wt % of Y 2 O 3 powder and 35 wt % of aluminum powder into 60 ml sodium silicate aqueous solution with modulus of 2.9 and density of 1.5 g/cm 3 , and then stirring evenly to prepare the slurry.
[0045] The detailed data of this embodiment is as follows: for a sample of a T91 steel pipe, the slurry is naturally attached to the inner wall of the T91 steel pipe after being injected into the steel pipe. After dried in an oven at 20° C. for 1 hour, the T91 steel pipe is dried in the oven at 85° C. for 2.5 hours. The dried steel T91 is put into an atmosphere furnace charged with a gas mixture of 60 vol % of helium (the purity is equal to or larger than 99.99%) and 40 vol % of water vapor at a heating temperature of 800° C. for 24 hours; thereafter, the atmosphere furnace is powered off and the steel T91 is naturally cooled to room temperature in the furnace. The sample is taken out after cooled to room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface rich in chromium and having a small amount of rare earth oxide.
[0046] The steel T91 is used in an environment at a temperature of 750° C. with 40 vol % of water vapor.
[0047] Embodiment 4: the solid powder mixture is composed of: yttrium oxide (Y 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 μm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0048] The slurry is prepared by firstly adding 100 g solid powder mixture of 70 wt % of Y 2 O 3 powder and 30 wt % of aluminum powder into 20 ml sodium silicate aqueous solution with modulus of 2 . 8 and density of 1.2 g/cm 3 , and then stirring evenly to prepare the slurry.
[0049] The detailed data of this embodiment is as follows: the dimension of a P91 steel sample is 10 x 15 x 3 mm; and the slurry prepared through the abovementioned method is coated on the surface of the P91 steel sample in a manual brush coating manner, and then after dried in an oven at 25° C. for 3 hours, the P91 steel sample is dried in the oven at 90° C. for 2 hours. The dried steel P91 is put into an atmosphere furnace charged with a gas mixture of 85 vol % of argon (the purity is equal to or larger than 99.99%) and 15 vol % of water vapor at a heating temperature of 780° C. for 30 hours; thereafter, the atmosphere furnace is powered off and the steel P91 is naturally cooled to room temperature in the furnace. The sample is taken out after cooled to room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface rich in chromium and having a small amount of rare earth oxide.
[0050] The steel P91 is used in an environment at a temperature of 600° C. with 25 vol % of water vapor.
[0051] Embodiment 5: the solid powder mixture is composed of: lanthanum oxide (La 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 pm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0052] The slurry is prepared by firstly adding 100 g solid powder mixture of 99 wt % of La 2 O 3 powder and 1 wt % of aluminum powder into 50 ml sodium silicate aqueous solution with modulus of 2.6 and density of 1.3 g/cm 3 , and then stirring evenly to prepare the slurry.
[0053] The detailed data of this embodiment is as follows: the dimension of a T91 steel sample is 10 x 15 x 3 mm; and the slurry prepared through the abovementioned method is coated on the surface of the T91 steel sample in a manual brush coating manner, and then after dried in an oven at 30° C. for 1 hour, the T91 steel sample is dried in the oven at 100° C. for 2 hours. The dried steel T91 is put into an atmosphere furnace charged with a gas mixture of 95 vol % of argon (the purity is equal to or larger than 99.99%) and 10 vol % of water vapor at a heating temperature of 690° C. for 40 hours; thereafter, the atmosphere furnace is powered off and the steel T91 is naturally cooled to a room temperature in the furnace. The sample is taken out after cooled to the room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface rich in chromium and having a small amount of rare earth oxide.
[0054] The steel T91 is used in an environment at a temperature of 500° C. with 5 vol % of water vapor.
[0055] Embodiment 6: the solid powder mixture is composed of: lanthanum oxide (La 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 pm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0056] The slurry is prepared by firstly adding 100 g solid powder mixture of 99.5 wt % of La 2 O 3 powder and 0.5 wt % of aluminum powder into 60 ml sodium silicate aqueous solution with modulus of 2.4 and density of 1.1 g/cm 3 , and then stirring evenly to prepare the slurry.
[0057] The detailed data of this embodiment is as follows: the dimension of a P91 steel sample is 10×15×3 mm; and the slurry prepared through the abovementioned method is coated on the surface of the P91 steel sample in a dip coating manner, and then after dried in an oven at 10° C. for 4 hours, the P91 steel sample is dried in the oven at 70° C. for 4 hours. The dried steel P91 is put into an atmosphere furnace charged with a gas mixture of 80 vol % of helium (the purity is equal to or larger than 99.99%) and 20 vol % of water vapor at a heating temperature of 600° C. for 48 hours; thereafter, the atmosphere furnace is powered off and the steel P91 is naturally cooled to room temperature in the furnace. The sample is taken out after cooled to room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface of the steel P91 rich in chromium and having a small amount of rare earth oxide.
[0058] The steel P91 is used in an environment at a temperature of 600° C. with 25 vol % of water vapor.
[0059] Embodiment 7: the solid powder mixture is composed of: lanthanum oxide (La 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 μm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0060] The slurry is prepared by firstly adding 100 g solid powder mixture of 65 wt % of La 2 O 3 powder and 35 wt % of aluminum powder into 10 ml sodium silicate aqueous solution with modulus of 2.9 and density of 1.5 g/cm 3 , and then stirring evenly to prepare the slurry.
[0061] The detailed data of this embodiment is as follows: for a sample of a T91 steel pipe, the slurry is naturally attached to the inner wall of the T91 steel pipe after being injected into the steel pipe. After dried in an oven at 20° C. for 1 hour, the T91 steel pipe is dried in the oven at 85° C. for 2.5 hours. The dried T91 steel is put into an atmosphere furnace charged with a gas mixture of 60 vol % of helium (the purity is equal to or larger than 99.99%) and 40 vol % of water vapor at a heating temperature of 800° C. for 24 hours; thereafter, the atmosphere furnace is powered off and the steel T91 is naturally cooled to room temperature in the furnace. The sample is taken out after cooled to room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface rich in chromium and having a small amount of rare earth oxide.
[0062] The steel T91 is used in an environment at a temperature of 750° C. with 40 vol % of water vapor.
[0063] Embodiment 8: the solid powder mixture is composed of: lanthanum oxide (La 2 O 3 ) with purity equal to or larger than 99.00% and granularity equal to or less than 30 μm; and aluminum powder with purity equal to or larger than 99.00% and granularity equal to or less than 0.4 mm.
[0064] The slurry is prepared by firstly adding 100 g solid powder mixture of 75 wt % of La 2 O 3 powder and 25 wt % of aluminum powder into 45 ml sodium silicate aqueous solution with modulus of 2.5 and density of 1.4 g/cm 3 , and then stirring evenly to prepare the slurry.
[0065] The detailed data of this embodiment is as follows: the dimension of a T91 steel sample is 10×15×3 mm; and the slurry prepared through the abovementioned method is coated on the surface of the T91 steel sample in a manual brush coating manner, and then after dried in an oven at 25° C. for 3 hours, the T91 steel sample is dried in the oven at 90° C. for 3 hours. The dried T91 steel is put into an atmosphere furnace with a gas mixture of 78 vol % of argon (the purity is equal to or larger than 99.99%) and 22 vol % of water vapor at a heating temperature of 750° C. for 35 hours; thereafter, the atmosphere furnace is powered off and the steel T91 is naturally cooled to room temperature in the furnace. The sample is taken out after cooled to room temperature in the furnace and is washed with distilled water to clean away the solid powder on the surface, thereby obtaining a surface of the steel T91 rich in chromium and having a small amount of rare earth oxide.
[0066] The steel T91 steel is used in an environment at a temperature of 650° C. with 38 vol % of water vapor. | Disclosed is a pretreatment method for improving antioxidation of steel T91/P91 in high temperature water vapor, which includes applying a slurry, containing rare earth oxide, on a surface of a substrate; holding the temperature in a gas mixture environment of inert gas and water vapor after drying; and cleaning away the solid powder left by the slurry on the surface, thereby obtaining the substrate with a surface rich in chromium and having a small amount of rare earth oxide. As a result of the method, the antioxidation capability of steel T91/P91 in the 500-750° C. water vapor environment can be improved, and films rich in chromium oxide can be formed on the surface of steel T91/P91. | 2 |
REFERENCE TO RELATED APPLICATIONS
This application is a division of the Moynihan et al. application Ser. No. 08/406,297 filed Mar. 17, 1995, which is a continuation-in-part of the co-pending Moynihan et al. application Ser. No. 08/215,301 filed Mar. 21, 1994 for SIMPLIFIED INK JET HEAD.
BACKGROUND OF THE INVENTION
This invention relates to ink jet head arrangements and, more particularly, to a new and improved ink jet head arrangement having a simple and inexpensive structure.
Conventional ink jet heads, in which ink received from an ink reservoir is ejected selectively through a series of orifices, have been made using thin plates of metal or ceramic material having appropriate passages which are bonded together in adjacent relation in an assembly, as described, for example, in the Roy et al. U.S. Pat. No. 5,087,930 and the Hoisington et al. U.S. Pat. No. 4,835,554. In such arrangements, each chamber or passage in the flowpath leading from the ink inlet to the orifice, through which the ink is ultimately ejected, is provided in one or more of the several plates in the assembly. This requires an array of plates having different thicknesses, each of which must be separately machined to precise dimensions to produce the appropriate chambers and passages, and also requires precise positioning of all of the chambers and passages in the plates. Moreover, the plates must be assembled and bonded together and to a piezoelectric plate in highly precise alignment, and each plate must be flat and free from burrs that would cause voids between adjacent plates. Furthermore, because of differences in the coefficients of thermal expansion between the materials used in the plates, bond stresses are generated by temperature variations which occur in connection with the manufacture and use of the ink jet head which must be overcome.
In hot melt ink jet printheads, which operate at elevated temperatures, the printhead materials must be good conductors of heat so that the printhead will warm up quickly and the temperature gradients during operation will be small. The stresses created when parts of different materials expand differently with changes in temperature is another concern. The prime mover in a printhead is usually a piezoelectric ceramic (PZT) which has a relatively low thermal expansion coefficient. For optimum printhead design, the challenge is to find other materials which are close to this expansion. If the printhead materials cannot be matched, it is desirable to have low-modulus materials to reduce the stresses.
The ink passages in an ink jet printhead are fine features with tight tolerances. To maintain such tight tolerances, the manufacture of the printhead requires low machining forces, small tool deflection and small machining errors, no plastic deformation and no burrs. Moreover, it may be desirable, particularly in development, that the manufacture should be carried out using standard machining methods, such as grinding, milling, drilling and shaping.
In addition, the printhead should be made of materials which are chemically inert and do not change shape over time when loaded or oxidize or interact with organic chemicals found in hot-melt and other inks or with pigments or dyes in the inks.
Heretofore, some plates used in ink jet heads have been photo-etched to provide the appropriate chambers and passages, which has the advantage that the plates are generally burr-free and can be made from Kovar material, stainless steel and other materials that have appropriate mechanical and thermal expansion characteristics. The materials useful for photoetching, however, have drawbacks when used in connection with ink jet heads from which hot melt ink is ejected since they generally have low thermal conductivity. In addition, the photo-etching process has the disadvantage of being a batch process with lot-to-lot variations and, moreover, when used in this manner, produces a relatively large quantity of chemical waste.
Furthermore, conventional piezoelectric plates used in ink jet heads are thin, fragile and susceptible to damage during processing. Because of the greater likelihood of damage to larger plates, the maximum size of piezoelectric plates is normally quite small, for example, less than about 100 mm, which correspondingly limits the length of an array of orifices through which ink is ejected as a result of the actuation of the piezoelectric plate.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an ink jet head which overcomes the disadvantages of the prior art.
Another object of the invention is to provide an ink jet head having a simple structure which is inexpensive to develop, is convenient to manufacture and is capable of providing high resolution ink jet printing.
These and other objects and advantages of the invention are attained by providing an ink jet head having at least one or more components formed from a carbon member. A preferred carbon component is one in which ink pressure chambers and connecting passages from ink supply lines and to ink jet orifices are formed. In one embodiment, a carbon component is a plate having pressure chambers formed on one side and flow-through passages to permit continuous ink circulation through the pressure chambers formed on the other side of the plate with connecting passages leading to an orifice plate and to an ink supply extending through the carbon plate. In addition, an orifice plate is affixed to one side of the carbon plate with the orifices aligned with orifice passages in the carbon plate and a piezoelectric plate is affixed to the other side of the carbon plate with actuating electrodes aligned with the pressure chambers to cause the piezoelectric material to be deflected so as to apply pressure to the corresponding pressure chamber and eject a drop of ink through a corresponding orifice in the orifice plate.
In another embodiment, a carbon pressure chamber plate is formed on opposite sides with linear arrays of pressure chambers having ink inlet and outlet passages at opposite ends. Both sides of the carbon plate are covered by corresponding piezoelectric actuation plates and a plurality of such carbon pressure chamber plates are retained in laterally adjacent relation in a carbon collar member with the ink outlet passages therein positioned in alignment with corresponding ink passages extending through a carbon manifold plate. A manifold plate has one side retained against the ends of the plurality of pressure chamber plates and has lateral ink passages formed in the opposite side leading to a line of orifices in an orifice plate mounted on the opposite side.
In accordance with one aspect of the invention, the carbon pressure chamber plate has an ink deaeration passage through which ink is supplied to the inlet passages leading to the pressure chambers and an internally supported, thin-walled tubular member made of air-permeable, ink-impermeable material connected at one end to a source of reduced pressure is inserted into the ink deaeration passage to provide a unitary ink deareating and pressure chamber carbon plate. This arrangement accomplishes the necessary deaeration of ink immediately before it is supplied to the pressure chambers with minimal space requirements and without necessitating recirculation of ink to an ink reservoir.
In connection with the assembly of carbon plate components of the above type in an ink jet head, it has been learned surprisingly that it is not necessary to cement or otherwise physically bond together carbon plate components having communicating a passages or to provide a gasket between them. Because the engaging surfaces of such carbon plate components can be made very smooth and flat and carbon plates are sufficiently rigid to avoid flexing, such plates can be mechanically fastened together by screws or the like without causing ink to flow between the components and, if desired, a filter layer may be interposed between the surfaces of such fastened components.
Because the carbon body can be machined precisely without causing burrs using conventional machining techniques and, since carbon has a low thermal coefficient of expansion, dimensional variations resulting from thermal expansion during machining are minimized on the plate. In addition, the carbon expansion coefficient is especially compatible with the piezoelectric plate which is affixed to it, thereby reducing or eliminating stresses between the plates which might otherwise be produced by temperature variations such as occur when the ink jet head is used with hot melt ink. Moreover, carbon is chemically inert with respect to materials in which it comes in contact in an ink jet head. It does not oxidize nor does it interact with organic chemicals found in hot-melt and other inks or with pigments or dyes used in inks.
According to another aspect of the invention, the piezoelectric plate has actuating electrodes on only one side of the plate and is prepared by a photo-etching technique in which a piezoelectric plate coated on one side with electrode material is affixed to the pressure chamber side of the carbon plate with the electrode material-coated side exposed. The exposed side of the plate is coated with a photoresist material and is then exposed to a desired electrode pattern in precise alignment with the pressure chamber pattern in the carbon plate, after which the photoresist is developed, the exposed electrode material is etched away, and the remaining photoresist is removed to produce an electrode pattern conforming exactly in shape and position to the pattern of pressure chambers in the carbon plate. In addition, the electrode pattern thus formed on the piezoelectric plate can include other electrical elements such as a heater to heat ink in the passages in the carbon plate.
In accordance with a further aspect of the invention, the carbon plate is porous, preferably being about 80-90% dense, and the porosity and a vacuum source communicating with the surface of the plate can extract dissolved air from ink in the ink passages separated from the porous carbon material by an air-permeable, ink-impermeable layer.
If desired, a page-size carbon plate can be prepared with a row of separate piezoelectric plates affixed to one side of the plate. Moreover, the carbon plate may have orifice passages formed in an edge of the plate rather than in one of the sides of the plate.
Since engineering grade carbon is friable, i.e., microscopic grains are readily broken away from a carbon body, it is easily shaped without producing burrs. As described in "Graphite Machinery Made Easy" EDM Today, Sep./Oct. 1993 pp. 24ff, the relative softness and lack of ductibility of such carbon allows it to be cut at high feed rates with little distortion and low tool wear. These characteristics permit carbon blocks to be readily formed into components of ink jet heads by conventional or unique machining techniques.
In one example, the formation of an array of closely adjacent pressure chambers for an ink jet head which have a long aspect ratio and require highly precise and uniform channel dimensions, would require prohibitively long machine cycle times using a conventional end mill. In accordance with another aspect of the invention, however, the process for manufacturing a carbon plate component of an ink jet head is greatly simplified by shaping the carbon plate using a series of linear motions against the surface of the carbon plate with a shaping tool having the desired profile. For the pressure chambers of a carbon pressure plate, for example, a tool having a series of closely spaced short teeth is scraped across the surface in several strokes to produce a series of precise channels of the required dimensions. To make a row of small diameter holes of substantial depth in one end of a body, two carbon plates may be shaped in a similar way with matching arrays of grooves having a depth equal to half the diameter of the desired holes and then cemented together with the grooves in alignment. Using certain tool shapes the holes may have a hexagonal shape rather than a circular shape.
Other machining techniques especially useful in shaping carbon bodies are electric discharge machining, which facilitates convenient formation of complex shapes, and laser machining, which can be used effectively for through holes and slots.
According to still another aspect of the invention, improved directionality of ink drop ejection from orifices supplied from nonaxial orifice passages is achieved by providing orifice plate orifices having cylindrical outlet nozzle passages, larger diameter cylindrical inlet passages, and a conical intermediate section joining the outlet and inlet passages.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will be apparent from a reading of the following description in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic perspective sectional view illustrating a representative embodiment of a simplified ink jet head arranged in accordance with the invention;
FIG. 2 is a plan view showing the pressure chamber side of a typical carbon plate for a multicolor ink jet head showing the arrangement of the pressure chambers and the related ink passages formed in the carbon plate;
FIG. 3 is a view of the carbon plate of FIG. 2 from the same side shown in FIG. 2, but illustrating the passages formed in the opposite side of the carbon plate;
FIG. 4 is a schematic view illustrating a typical arrangement of electrodes on the exposed surface of a piezoelectric plate used with the carbon plate shown in FIGS. 2 and 3;
FIG. 5 is a schematic plan view of a typical large-size carbon plate having a series of piezoelectric plates mounted on one surface in accordance with another embodiment of the invention;
FIG. 6 is a schematic perspective view illustrating another representative embodiment of the invention;
FIG. 7 is a schematic perspective sectional view similar to FIG. 6, illustrating another typical embodiment of the invention;
FIG. 8 is a schematic perspective view illustrating a further representative embodiment of the invention;
FIG. 9 is a fragmentary perspective view illustrating a modified form of the invention;
FIG. 10 is a perspective view showing a typical shaping tool for shaping arrays of ink passages in a carbon body for use in an ink jet head;
FIG. 11 is a schematic view illustrating one representative method for poling a piezoelectric plate;
FIG. 12 is a schematic view illustrating another representative method for poling a piezoelectric plate;
FIG. 13 is a fragmentary view in longitudinal section showing the shape of an orifice in an orifice plate in accordance with the invention.
FIG. 14 is an exploded perspective view illustrating another representative embodiment of a simplified ink jet head arrangement in accordance with the invention;
FIG. 15 is a side view illustrating a representative carbon pressure chamber plate of the type used in the arrangement shown in FIG. 14;
FIG. 16 is an end view of the representative carbon pressure chamber plate shown in FIG. 15;
FIG. 17 is a top view of the carbon collar block used in the arrangement shown in FIG. 14;
FIG. 18 is a side view of the collar block shown in FIG. 17;
FIG. 19 is a plan view showing one side of a representative carbon manifold plate of the type used in the arrangement shown in FIG. 14; and
FIG. 20 is a plan view showing the opposite side of the manifold plate of FIG. 19;
DESCRIPTION OF PREFERRED EMBODIMENTS
In the typical embodiment of the invention schematically shown in FIG. 1, an ink jet head 10 includes a reservoir 11 on one side containing ink which is to be selectively ejected in the form of drops through an array of orifices 12 formed in an orifice plate 13 mounted on the opposite side of the head. Ink from the reservoir 11 is supplied through a passage 14 to a deaerator 15 in which an ink path 16 extends between air-permeable, ink-impermeable membranes 17, each of which is backed by a vacuum plenum 18 connected through ports a to a remote vacuum source (not shown) to extract dissolved air from the ink. Deaerated ink from the passage 16 is conveyed through a passage 19 to a pressure chamber 20 from which it is ejected on demand through an orifice passageway 21 and a corresponding orifice 12 in the orifice plate 13 in response to selective actuation of the adjacent portion 22 of a piezoelectric plate 23.
The general arrangement of the ink jet head 10 and the deaerator 15 is of the type described, for example, in the Hine et al. U.S. Pat. No. 4,937,598, the disclosure of which is incorporated herein by reference. The ink in the reservoir 11 may, if desired, be hot melt ink which is solid at room temperature and liquid at elevated temperatures, in which case heaters (not shown) are mounted at appropriate locations in the ink jet head 10.
In order to permit the ink supplied to the orifices to be deaerated continuously even though ink is not being ejected through the orifices 12, the head includes a flow-through passage 24 extending from each orifice passage 21 to a return passage 25 leading back to the deaeration path 16 in the deaerator 15, and a continuous slow circulation of ink through the duct 19, the chamber 20, the orifice passage 21, the flow-through passage 24 and the duct 25 back to the deaerator passage 16 is maintained by thermal convection, as described, for example, in the Hine et al. U.S. Pat. No. 4,940,995 issued Jul. 10, 1990, the disclosure of which is incorporated herein by reference. For this purpose, a heater (not shown in FIG. 1) is arranged to heat the ink near the lower end of the flowpaths consisting of the passages 19, 20, 21, 24 and 25 above its normal temperature to cause a convective flow of the ink through those passages, thereby conveying the ink back to the deaerator 16.
In accordance with the invention, the passages 19, 20, 21, 24 and 25 are formed in a plate 26 made of engineering carbon graphite, which is preferably about 80-90% dense, providing a slightly porous plate structure. The carbon plate 26 is machined by micromachining techniques from opposite sides to produce the chambers and passages required for the ink jet head. The carbon plate can be machined by milling, drilling, broaching, grinding and the like, using conventional tools providing high material removal rates with minimum tool wear, to produce openings with much closer tolerances than the conventional metal plates of the type described, for example, in the Hoisington et al. U.S. Pat. No. 4,835,554. Because the carbon material is friable, no burrs are produced during machining. Moreover, the coefficient of thermal expansion of the carbon graphite body is substantially the same as that of the ceramic piezoelectric material of which the piezoelectric plate 23 is made so as to reduce or substantially eliminate thermal stresses which occur between those components of the head as a result of variations in temperature.
The preferred carbon material for use in forming components on ink jet heads is polycrystalline graphite, which is a mixture of small crystals of graphite sintered with amorphous carbon (lamp black). This produces an amorphous matrix of small (0.025-5μ) grains and smaller (0.005-0.2μ) pores. This material, which is different from powdered graphite and carbon fiber materials, offers many benefits, including good thermal conductivity, coefficient of thermal expansion close to ceramic piezoelectric materials, good machinability, dimensional stability and chemical inertness.
The thermal properties of polycrystalline graphite (Grade DFP-1 available from POCO Graphite, Inc., Decatur, Tex.) and other materials which might be considered for printheads are compared with those of lead zinc titanate (PZT) ceramic piezoelectric material in Table 1 below:
TABLE 1______________________________________ Thermal Conductivity Expansion ModulusMaterial (W/CmK) (μ/m/degC) (x10.sup.5 kg/cm.sub.--)______________________________________PZT .015 2 to 4 7Thermoplastic 0.0022 56 0.15(Ultem)Aluminum (6000) 1.7 23.4 7Carbon (DFP-1) .75 8.4 1.1______________________________________
The Ultem (as well as other thermoplastics) has both poor conductivity and a very high thermal expansion coefficient. The conductivity of aluminum is attractive, but its high thermal expansion and modulus are problems. Polycrystalline carbon offers a good combination of all three properties.
A potentially prohibitive aspect of the use of carbon members for ink jet components is the forming of closely spaced arrays of pressure chambers and other multitudinous, long aspect ratio, channels with precise dimensions. Using an end mill for these features could be expected to result in excessively long machine cycle times. To overcome this problem, a desired array of adjacent channel profiles is shaped in the surface of a carbon body by a specially formed tool 95, shown in FIG. 10, in a series of repeated linear motions or "scrapes." In the tool 95 for example, an array of 64 short uniformly spaced teeth 96 may be provided at one end of the tool to cut 64 parallel pressure chambers in the surface of a carbon plate. If the tool cuts at 0.025 mm per scrape, a depth of 0.15 mm can be achieved in 6 scrapes, which requires only a few seconds of machine time. The tool 95 makes an array of channels equal to the width of the tool, and can make a wider array by taking repeat adjacent passes. Tool irregularities are averaged out by taking finish cuts in the reverse direction or at a one-tooth off-set. Reversing the tool also allows the formation of steeper channel ends when this is required. This technique can be used to make pumping chambers, manifold passages, flow-through passages, and the like. Finally, channels of variable or tapered depth can be made as well, by raising or lowering the tool as a cut is being made.
For an array of closely spaced deep, small diameter holes in a carbon body, where the depth is more than 3 times the drill diameter, drilling can become difficult and expensive. To provide an array of closely spaced holes having a diameter of, for example, 0.28 mm through a carbon plate 1.75 mm thick would require a great deal of time and a number of expensive drills. To form such an array in a simple manner, matching arrays of channels (which may be semi-hexagonal in shape) 0.14 mm deep are formed in two matching blocks of carbon which are then bonded together with adhesive to form a single block containing an array of parallel, long 0.28 mm diameter holes. This block is then sliced perpendicularly to the axes of the holes and ground flat to form the array bodies. The adhesive joint down the middle of the array body has been found to be very strong.
Polycrystalline carbon is easily bonded by a variety of adhesives. Three systems are particularly compatible with carbon in hot melt ink jet head applications. The first is a simple dispensed epoxy which works well for coarse scale joints. The second is a thermoplastic sheet adhesive. Using this technique, a thin teflon (TFE) sheet compressed at elevated temperature and pressure provides a tenacious bond between flat surfaces of polycrystalline carbon. Similarly, acrylic sheet adhesives should perform well at lower temperature. In the third technique, a dilute sprayed B-stage epoxy system is applied to the surfaces to be bonded. This has been shown to be adaptable to the complex geometries of ink jet printheads, yet high in strength at elevated temperatures.
There is some challenge in bonding a porous material like carbon with a spray application technique. Since excess adhesive will clog small passages, and thin layers may be drawn by capillary forces into the carbon body pores, careful control of process variables is required. In particular, the carbon pore structure must be uniform, the spray-deposited layer thickness must be small compared to the particle/pore size, and the heat cure process must be tuned to the adhesive rheology.
FIG. 2 illustrates a representative arrangement of pressure chambers 20 and orifice passages 21 as viewed from the piezoelectric plate side of the typical carbon monolithic plate 26 of FIG. 1, while FIG. 3 illustrates the other ends of the orifice passages 21 and the flow-through passages 24 which are formed in the opposite side of the monolithic array 26. FIG. 3, while showing the passages on the side of the monolithic array 26 which face the orifice plate 13, is illustrated with the passages seen as they would be viewed in the same direction as FIG. 2.
FIGS. 2 and 3 show supply passages for supplying four different color inks, e.g., black, yellow, magenta and cyan, to four different groups 27, 28, 29 and 30 of the orifice passages 21. Since black ink is normally used to a much greater extent than the colored inks, half of the orifice passages 21 are arranged to supply black ink, and one-third of each of the remaining passages are arranged to supply each of the colored inks.
As illustrated in FIG. 2, the pressure chambers 20 of the array are alternately disposed on opposite sides of the line of orifice passages 21 and are supplied from grooves formed in the pressure chamber side of the graphite plate 26, for example, from grooves 32 and 33 supplying black ink, grooves 34 and 35 supplying magenta ink, grooves 36 and 37 supplying yellow ink, and grooves 38 and 39 supplying cyan ink. The appropriate color ink is supplied to these grooves through corresponding apertures 40 and 41, 42 and 43, 44 and 45 and 46 and 47, which extend through the carbon plate 26 to corresponding sets of grooves 50 and 51, 52 and 53, 54 and 55 and 56 and 57, formed in the opposite side of the plate. Those grooves, shown in solid lines in FIG. 3 and in dotted lines in FIG. 2, communicate with further apertures 60 corresponding to the passages 19 and 25 of FIG. 1, which extend through the plate to convey ink from the deaerator ink path 16 of FIG. 1 to the pressure chamber supply grooves 32-39. As shown in FIG. 3, the flow-through passages 24 convey ink between the orifice passages 21 and the groove patterns 50-57 on the opposite side of the carbon plate to complete the continuous path for circulation of ink through the deaerator 15.
In addition, the carbon plate 26 is especially advantageous for ink jet heads used with hot melt ink. Because of its high thermal conductivity, the carbon plate provides excellent heat conduction from heaters mounted at relatively remote locations in the head to all of the ink passages in the head. This assures that the hot melt ink at each of the orifices 12 is at the same temperature and therefore has the same viscosity, thereby providing good uniformity of operation throughout the length of the array of orifices.
A typical carbon plate 26 may be about 2 mm thick and have orifice passages 21 about 0.2 mm in diameter, pressure chambers about 9 mm long, 0.5 mm wide and 0.2 mm deep, supply grooves about 1.0 to 1.5 mm wide and 0.5 mm deep, flow-through passages about 4 mm long, 0.1 mm wide and 0.05 mm deep, and apertures 60 about 1.5 mm in diameter. With this arrangement, a 96-aperture linear array of the type shown in the drawings can be provided in a carbon plate 26 having dimensions of about 4 cm by 7 cm with the orifice passages 21 spaced by about 0.5 mm. When oriented at an appropriate angle with respect to the scanning direction, an ink jet head using an array of this type can produce a resolution of about 300 dots per inch (120 dots per cm) in the subscanning direction and, when actuated at a rate of about 14 Khz at a scanning rate of 1m/sec to produce 100 picoliter drops, can produce the same resolution in the scanning direction.
In certain high-frequency ink jet applications, the rigidity of the walls of the pressure chambers 20 formed in the carbon plate may be less than desired, requiring a higher operating voltage for the piezoelectric actuating plate. To alleviate this, the surfaces of the pressure chambers 20 formed in the carbon plate may be coated with a thin layer, such as 0.01 to 0.1 mm thick, of a very hard (i.e., high modulus of rigidity) material such as a carbide or nitride, e.g., silicon carbide or nitride, boron carbide or nitride, tungsten carbide or nitride, tantalum carbide or nitride, or the like. Preferably, the coating is applied by chemical vapor deposition.
In order to actuate the piezoelectric plate 23 so as to selectively eject ink from the pressure chambers 20 through the orifice passages 21 and through corresponding orifices 12 in the orifice plate 13, the piezoelectric plate 23, which is mounted on the pressure chamber side of the carbon plate, has no electrodes on the carbon plate side and is patterned with an electrode array of the type shown in FIG. 4 on the exposed side. In the array shown in FIG. 4, a common electrode 65 extends along the portion covering the orifice passage array in the carbon plate and also extends laterally into regions 66 over the carbon plate surface portions between the pressure chambers.
Interlaced between the lateral extensions 66 is a spaced array of individual electrodes 67 which are positioned directly over the pressure chambers in the carbon plate so that, when selectively actuated by application of appropriate potential to a corresponding terminal 68, the piezoelectric plate 23 is mechanically distorted in the shear mode in the direction toward the adjacent pressure chamber 20 so as to cause ejection of an ink drop from the orifice with which that pressure chamber communicates. Shear-mode operation of a piezoelectric plate is described, for example, in the Fischbeck et al. U.S. Pat. No. 4,584,590, the disclosure of which is incorporated herein by reference. Such shear-mode operation does not require any electrode on the opposite side of the piezoelectric plate but, if desired, the carbon plate 26, being conductive, can be used to provide an electrode on the opposite side of the plate.
The electrode pattern shown in FIG. 4 also includes a heater conductor 70 having a thermistor temperature control switch 71 extending between two terminals 72 and 73 and arranged to heat the ink in the passages in the lower portion of the carbon plate 26 so as to cause circulation of the ink in the manner described above by thermal convection. Because the carbon material in the plate 26 has a high thermal conductivity, the plate acts as a thermal conductor between the heater and the adjacent ink passages in the plate.
In order to form an electrode pattern of the type shown in FIG. 4 on the piezoelectric plate 23, the plate, which is initially provided with a continuous conductive coating on the exposed side, is permanently affixed by an epoxy adhesive to the pressure chamber side of the carbon plate 26. Since the carbon plate is slightly porous, an epoxy adhesive can be used to mount not only the piezoelectric plate 23, but also the orifice plate 13, to the opposite surfaces of the carbon body. For this purpose, one of the surfaces of the plates to be joined is preferably spray-coated with a layer of B-stage epoxy adhesive about 2 microns thick before the piezoelectric plate 23 or the orifice plate is applied to it. Such a thin layer of epoxy adhesive provides excellent seals between the plates, including the very narrow portions between the orifice passages, but does not flow into the passages or apertures in such a way as to interfere with the operation of the head.
In order to ground the surface of a the piezoelectric plate which is bonded to the carbon body, the epoxy adhesive may be doped with conductive particles. Alternatively, the clamping force applied during bonding of the piezoelectric plate to the carbon body is increased until the epoxy adhesive is driven into the carbon body to provide a large number of point contacts between the plate and the carbon body.
The use of single sided piezoelectric plates requires special techniques for poling the plates. According to one technique, schematically shown in FIG. 11, a piezoelectric plate 140 is compressed between two electrodes 143 and 144 separated from the plate 140 by two slightly conductive rubber sheets 141 and 142 to provide intimate electrical contact throughout the surfaces of the plate while limiting the current available for arcing if a breakdown occurs. When this procedure is carried out in two steps to minimize piezo stresses, high yield poling of unmetalized piezoelectric plates is achieved.
The other poling technique, shown in FIG. 12, uses a corona discharge to set up a poling field across the piezoelectric plate. A piezoelectric plate 150 is laid on a flat ground plate 151, and a corona discharge device 152 rains charges 153 down onto the surface. When the applied charge is sufficient to create an occasional breakdown through the plate, which is non-destructive because of the high surface resistance of the piezoelectric material, the plate is poled. This process is preferably carried out at an, elevated temperature, such as 100°-150° C., to ameliorate poling stresses.
The orifices 12 in the orifice plate 13 of FIG. 1, which may be a stainless steel plate about 0.05 mm thick, are preferably about 0.05 mm in diameter and are formed by electrical discharge machining. By selecting the appropriate size wire and controlling the current/voltage profile, the size and shape of the orifice can be controlled accurately. Bonding of the orifice plate to the surface of the carbon body is accomplished in the same way as the bonding of the piezoelectric plate.
With conventional bell-mouthed shaped orifices in an orifice plate of the type shown, for example, in the Hoisington et al. U.S. Pat. No. 5,265,315 in which the orifice diameter decreases at a continuously decreasing rate from a large diameter on the side of the orifice plate facing the ink jet head to a smaller diameter about one-third that of the large diameter on the side of the orifice plate through which the ink drop was ejected, the direction of ink drop ejection is very sensitive to asymmetries in the ink path near the periphery of the entrance to the bell-mouthed orifice. Moreover, it is not possible to space such bell-mouthed orifices as closely as desired for high resolution printing.
To overcome this problem, electrical discharge machining is used to form orifices 97 having the shape shown in FIG. 13 with a cylindrical inlet section 98, a smaller diameter cylindrical nozzle section 99 providing the outlet from the orifice plate and a tapered section 100 having a conical surface joining the inlet section and the nozzle section. It has been found that with an orifice design of this type, the non-axial velocity component of an ejected drop, i.e. the extent of deviation from the axial arrow 101 resulting from asymmetry of the passage leading to the orifice is reduced by more than 50%.
In a typical orifice plate 13 having a thickness of 0.05 mm, a nozzle 99 having a diameter of 0.054 mm and a length of 0.01 mm, a tapered section 100 having a cone angle of 30° and a length of 0.01 mm and an inlet section 98 having a diameter of 0.11 mm and a length of 0.03 mm, a substantial improvement in axial projection of drops supplied from an asymmetric ink path leading to the orifice was obtained. For an orifice plate 13 having a thickness of 0.075 mm and having the same nozzle and tapered section dimensions described above, and having an inlet section 0.055 mm long, a similar improvement in the direction of projection of drops was obtained at a slightly increased pressure drop. Preferably, the diameter of the inlet portion 98 of the orifice is no more than twice the diameter of the nozzle portion 99 and the length of the inlet portion 98 is greater than that of the nozzle portion. Such orifice shapes having successive conical and tapered cylindrical sections can be obtained by appropriate conventional electrical discharge machining techniques.
In accordance with one aspect of the invention, after the piezoelectric plate 23 has been affixed to the carbon plate, a layer of photoresist material is coated on the exposed surface and, using the precisely known positions of the pressure chambers from a reference edge in the carbon body, the photoresist is exposed to produce a pattern which corresponds exactly with the locations of the pressure chambers, and the unexposed resist is removed in the usual manner. Thereafter, the conductive layer is etched away from the exposed surface of the piezoelectric plate and the remaining resist is then removed to provide the final electrode pattern.
In this way, the piezoelectric plate 23, which is preferably only about 0.1 to 0.25 mm thick and is quite fragile, is protected from damage during the formation of the electrode pattern and other head-manufacturing steps. Consequently, substantially large piezoelectric plates, for example, 50 mm by 100 mm or more, can be used without substantial risk of damage during processing. Moreover, large-scale production is facilitated since a large-size carbon plate can be machined with multiple identical or similar patterns, and a corresponding number of piezoelectric plates can be bonded to the pattern locations on the large sheet and simultaneously exposed and etched to form electrode patterns corresponding precisely to the structures of the adjacent portions of the carbon plate, after which the large-size plate is separated into individual plates.
Furthermore, instead of separating a large-size carbon plate into smaller plates, a single carbon plate 20 cm wide, or even 150 cm wide, if appropriate, may be made to provide a page-width ink jet head by mounting a row of piezoelectric plates to one surface and simultaneously processing the piezoelectric plates in the manner described above. A typical page-width ink jet head is shown in FIG. 5, in which a carbon plate 26 has a row of adjacent piezoelectric plates 23 affixed to one side. The ink jet head of FIG. 5 has internal passages arranged to supply ink to an orifice plate 74 mounted on one edge, as described hereinafter with respect to FIG. 8. Alternatively, if desired, the large-size plate 26 of FIG. 5 may have internal passages of the type described above with respect to FIG. 1 leading to an orifice plate (not shown in FIG. 5) mounted on the opposite side of the carbon plate.
As an alternative to the deaerator arrangement 15 shown in FIG. 1, the use of a carbon plate 26 which is slightly porous permits the plate to act as a conduit between the vacuum plenum and the ink in the passages within the carbon plate in the manner shown in the alternative embodiment of FIG. 6 so that dissolved air can be extracted. For this purpose, the surfaces of the plate passages are coated with a layer 75 of an air-permeable, ink-impermeable epoxy resin and one or more openings 76 are provided in the piezoelectric plate 23 to expose the adjacent surface of the carbon plate 26 to a vacuum source 77 which replaces the deaerator 15, the other exposed surfaces of the carbon plate 26 being sealed to prevent entry of air into the porous plate. The vacuum source 77 may be connected to a remote vacuum supply through the port 18a, or it may be a replaceable vacuum reservoir of the type described in the copending Hine application Ser. No. 08/143,165, filed Oct. 26, 1993, now abandoned the disclosure of which is incorporated herein by reference.
In another modified deaerator arrangement shown in FIG. 7, ink passages 80 extending between the passages 24 and 25 are formed in a plate 81 which is mounted on the front surface of the carbon plate 26 and an air-permeable, ink-impermeable membrane 82, similar to the membranes 17 of FIG. 1, is positioned between the carbon plate 26 and the plate 81. In this case, the coating 75 applied to the various passages within the carbon plate 26 is impermeable to air and only the portion of the plate 26 adjacent to the membrane 82 is used to extract air from the ink in the passages 80. If desired, a filter may also be incorporated in the plate 81 in the path of the ink between the passages 24 and 25. Otherwise, the arrangement of FIG. 7 is the same as that shown in FIG. 6.
Because the high thermal conductivity of the carbon plate 26 assures heat conduction from relatively remote heaters through the carbon plate to hot melt ink adjacent to an orifice plate, a hot melt ink jet head according to the invention may be arranged so that the ink is ejected from an orifice plate mounted on an edge of a carbon plate rather than from an orifice plate mounted on one side of the carbon plate. Moreover, even if the ink used in the ink jet head is not hot melt ink, the easy machinability of the carbon plate provides a distinct advantage in an arrangement of this type in contrast to a conventional laminated plate arrangement, in which edges of the plates adjacent to the orifice plate cannot be perfectly aligned, leading to irregularities in the mounting of the orifice plate.
This arrangement is shown in FIG. 8, in which a carbon plate 85 has pressure chambers 86 formed in one side and a piezoelectric plate 87 affixed to that side of the plate, and a bottom cover plate 88 affixed to the opposite side of the plate. A row of orifice passages 89, which are drilled into one edge 90 of the carbon plate 85, communicate with the pressure chambers 86 through perpendicular passages 91 extending through the plate 85. With a carbon plate 85 of this type, the end surface 90 can be ground perfectly flat and the plate can then be drilled to form the passages 89 and 91 to connect with the pressure chambers 88, after which an orifice plate 92 is affixed to the edge 90 by epoxy adhesive in the manner described above.
An ink jet head made in this way is especially advantageous, not only because it requires only a very narrow strip for the orifice plate 92, but also because it permits the bulk of the printhead to be spaced from the paper path and also permits stacking of multiple printheads.
If desired, the ink jet head of FIG. 1 can be modified to provide similar advantages by forming the carbon plate 26 with a projecting portion 94 through which orifice passages 93 extend to an orifice plate 92, as illustrated in FIG. 9.
In a further embodiment of the invention shown in FIGS. 14-20, an ink jet head is assembled from a plurality of carbon components. In this embodiment, as illustrated in the exploded view of FIG. 14, two carbon pressure plate assemblies 102, described in greater detail hereinafter, are assembled in a carbon collar 103 so that their end surfaces, which contain ink outlet passages, are aligned with corresponding openings in a manifold plate 104 to which the pressure chamber plate assemblies 102 are affixed by screws 105 extending through the manifold plate and into an adjacent pressure chamber plate 106. An orifice plate 107 has a linear array of closely spaced orifices 108 which are aligned with the ends of arrays of passages 109 (FIG. 20) in the manifold plate 104 so as to eject ink in response to selective actuation of the pressure plate assemblies.
Interposed between the ends of the pressure plate assemblies 102 and the manifold plate 104 is a filter layer 110 having pores or openings slightly smaller than the orifices 108 in the orifice plate 107 so as to prevent potentially orifice-clogging solid material from reaching the orifices 108 but large enough to permit particles of solid material smaller than the size of the orifices to pass through the filter layer. This type of filter is described, for example, in the copending Moynihan et al. application for "Filter Arrangement For Ink Jet Head" Ser. No. 08/231,102, filed Apr. 22, 1994.
An ink reservoir 111, mounted against one side of the collar 103 has an ink supply opening 112 which supplies ink to the collar 103. As best seen in FIG. 16, a corresponding opening 113 in the collar is aligned with the opening 112 to receive ink from the reservoir 111. In addition, if hot melt ink is to be used in the ink jet head, a cartridge heater 114 is mounted in a groove 115 formed in the side of the reservoir and in a corresponding groove 116 (FIG. 18) in the side of the collar 103 and is controlled so as to maintain the ink within the assembled ink jet head at a desired temperature during operation of the system.
Each pressure chamber assembly 102 includes a pressure plate 106 having arrays 117 of closely spaced pressure chambers formed on opposite sides of the plate 106 and each of those arrays is covered by a piezoelectric plate 118 of the type described previously with respect to FIG. 4, having an array of electrodes 119 arranged with respect to the array of pressure chambers 117 to change the volume of the corresponding pressure chamber in response to appropriate electrical signals.
The pressure chamber plate 106, which is illustrated in greater detail in FIGS. 15 and 16, has a longitudinally extending opening 120 which, in the illustrated embodiment receives ink through an internal passage 123 terminating at an end surface 124 which faces the manifold plate 104 as seen in FIG. 14. As shown in FIG. 19, the surface of the manifold plate 104 facing the pressure chamber plate, has an opening 125 which receives ink from the collar passage 113 and supplies it to a groove 126 (FIG. 20) on the opposite side of the manifold plate, from which ink passes through two further openings 127 in the manifold plate to the passages 123 in the pressure plates 106 so that the ink is distributed through the longitudinal opening 120 to all of the pressure chambers in both of the arrays 117 in each plate.
In order to extract dissolved air from the ink as it is being supplied to the arrays 117 of pressure chambers, a deareator 128 consisting of a tubular member 129 made of air-permeable, ink-impermeable material, such as extruded polytetrafluoraethylene having a 0.1 mm wall thickness and a 1.5 mm internal diameter, extends through an opening 130 in the edge of each pressure chamber plate 106 and into the longitudinal opening 120. A plug 131 closes the inner end of the tube and the end projecting out of the opening 130 in the plate 106 is connected to a vacuum source 132 supplying sufficient negative pressure, such as 0.7 atmosphere, to reduce the dissolved air content of the ink being supplied to the pressure chambers below the level at which air bubbles can form in the pressure chamber during operation of the ink jet system. In order to prevent the tube 129 from collapsing in response to application of negative pressure, a porous support, such as a rod of porous carbon or a helical wire having a diameter substantially equal to the internal diameter of the tube, is inserted into the tube.
As shown in FIG. 16, the end surface 124 of the carbon plate 106 has two arrays of ink passages 133 which extend perpendicularly to the end surface 123 and each of those passages communicates internally with the adjacent end of a corresponding pressure chamber in the arrays 117. Consequently, upon actuation of one of the pressure chamber, ink is forced out of the plate 106 through a corresponding one of the passages 133.
After passing through the filter layer 110, ink from each of the passages 133 is supplied through a corresponding passage 134 in an adjacent surface of the manifold plate 104 shown in FIG. 17 and, as shown in FIG. 20, the arrays of passages 109 in the opposite surface of the manifold plate extend horizontally along the surface of that plate to convey the ink supplied through the passages 134 in a lateral direction toward the center of the manifold plate. Those passages terminate in a central line 135 extending longitudinally along the manifold plate so as to be in line with the line of ink jet orifices 108 in the orifice plate 107.
Although carbon is the preferred material for the manifold plate 104, especially for ink jet heads used with hot melt ink, other materials which can be formed with a sufficiently flat surface and which have a thermal expansion coefficient compatible with adjacent components may also be used. For example, steel and ceramics such as alumina and glass, in which appropriate passages can be formed by photoetching, may also be used to form the manifold plate.
In a typical embodiment of the type shown in FIGS. 14-20, each pressure chamber plate 106 is approximately 75 mm long, 22 mm wide and 2.5 mm thick and each pressure chamber array 117 contains 64 pressure chamber approximately 9 mm long, 1 mm wide and 0.15 mm deep and the manifold plate 104 is approximately 1.4 mm thick.
Heretofore it was believed that the total length of the descender, which is the ink path leading from the end of the pressure chamber to the orifice in the orifice plate, should be as short as possible, i.e. no more than about 1 mm. Although it is clear that each descender should have a constant cross-section similar to that of the pumping chamber so that its acoustic properties do not result in undesirable reflections, and that it should be short enough that viscus flow losses are not excessive and that it should also be fluidically stiff so that pressure energy losses from the surrounding structure are not excessive, it has now been determined that, in ink jet heads made of carbon components, the descender need not be so limited in length and can consist of a plurality of passages such as those in the manifold plate and within the pressure chamber plate which total as much as 7 mm in length without loss of performance. This permits greater flexibility in the design of ink jet heads in several respects. For example, the piezoelectric plate, which is quite fragile, can be spaced a significantly greater distance away from the substrate being printed by the head and the body of the ink jet array may be made thick enough to be mechanically robust and to provide good thermal uniformity. Moreover, laterally spaced pressure chambers such as those in the arrays 117 may be connected through laterally spaced passages 133 to supply ink to a single line of orifices 108 by using an arrangement of laterally directed passages 109 such as that incorporated into the manifold plate 104.
With the simplified ink jet head according to the invention, the problems caused by burrs and dimensional variations resulting from heat produced in machining, by differences in temperature coefficient of expansion of the materials used in the ink jet head, and by the necessity for assembling a number of previously formed plates in precise relation, and the problems of bond stresses during temperature cycling are effectively eliminated in a convenient and inexpensive manner. Moreover, the number of steps required for the formation of the electrode pattern on the piezoelectric plate and application of the plate to the ink jet head is substantially reduced and variations in electrode positioning with respect to the pressure chamber positions are eliminated.
Although the invention has been described herein with reference to specific embodiments, many modifications and variations therein will readily occur to those skilled in the art. Accordingly, all such variations and modifications are included within the intended scope of the invention. | In the embodiments described in the specification, a ceramic piezoelectric plate is polarized by compressing the plate between electrode plates with intervening slightly conductive rubber sheets or by applying electric charge from a corona discharge device to one surface of the plate while the opposite surface is grounded until the applied charge is sufficient to create a breakdown. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 11/773,617, entitled “DOWNDRAFT GASIFIER WITH INTERNAL CYCLONIC COMBUSTION CHAMBER”, filed Jul. 5, 2007.
This application claims the priority of U.S. Provisional Patent Application No. 61/076,180, entitled “GASIFICATION OF SWITCHGRASS USING A DOWNDRAFT REACTOR,” filed Jun. 27, 2008, the contents of which are hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with U.S. Government support under USDA/CSREES Grant No. 00-52104-9662, USDA/CSREES Grant No. 2001-34447-10302, USDA/CSREES Grant No. 2002-34447-11908, USDA/CSREES Grant No. 2003-34447-13162, USDA/CSREES Grant No. 2004-34447-14487, USDA/CSREES Grant No. 2005-34447-15711, USDA/CSREES Grant No. 2006-34447-16939, and USDA/CSREES Grant No. 2008-34447-19201 awarded by the Department of Agriculture and under DOT/OST Grant No. DTOS59-07-G-0053 awarded by the Department of Transportation. The Government has certain rights in the invention.
FIELD OF THE INVENTION
This disclosure relates to gasification of biomass materials in general and, more specifically, to gasification by downdraft gasifiers.
BACKGROUND OF THE INVENTION
Biomass may be converted into useful gas products such as carbon monoxide (CO), carbon dioxide (CO 2 ), hydrogen (H 2 ), and others. There are multiple processes by which the raw biomass materials may be gasified. These include pyrolysis, tar cracking, and char gasification. Heating the biomass material under the proper circumstances such that the desired gases are released without being oxidized or otherwise consumed is one commonality among certain of the various gasification methods.
In order to obtain useful quantities of gases from raw biomass material, the gasification process must be implemented in such as way as to operate in a steady state. The desirable gases, or production gases, should more or less be output at a steady rate. Improper handling and processing of the biomass can result in a suboptimal amount of the raw biomass being gasified. Unacceptably high levels of undesirables can also be produced and taint the output gases if the production process is not controlled.
SUMMARY OF THE INVENTION
The invention disclosed and claimed herein, in one aspect thereof, comprises a downdraft gasifier. The gasifier includes a biomass section that accepts and stirs raw biomass materials, a pyrolysis and tar cracking section having an inner cylinder for receiving biomass and an outer surrounding cylinder for gases from the biomass, and a char gasification section for receiving biomass and gases from the pyrolysis and tar cracking section. The char gasification section provides a grating and scraper for passing gases and ash and retaining biomass for char gasification on the grate.
In some embodiments, the biomass section is arranged superior to the pyrolysis and tar cracking section, and the pyrolysis and tar cracking section is arranged superior to the char gasification section. In some embodiments, the inner cylinder defines a plurality of perforations on at least a portion thereof. A biomass feeding unit may selectively provide biomass through an airlock to the biomass section.
A cyclone separator may remove particulate from the gas leaving the char gasification section. An ash chamber may be provided below the char gasification section that catches ash and solid matter falling through the grate. An ash conveyor may remove ash from the ash chamber to a remote ash chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating one embodiment of a gasification system according to aspects of the present disclosure.
FIG. 2 is a schematic diagram illustrating one embodiment of a gasification combustion chamber for use with the gasification system of FIG. 1 .
FIG. 3 illustrates an exemplary temperature profile of a downdraft gasifier constructed according to FIG. 1 .
FIG. 4 illustrates the pressure drop and volumetric concentrations of various output gases from a gasifier constructed according to FIG. 1 .
FIG. 5 is a flow diagram illustrating an embodiment of a gasification process according to the present disclosure.
FIG. 6 is a schematic diagram illustrating another embodiment of a gasification system according to aspects of the present disclosure.
FIG. 7 . illustrates a temperature profile of the gasification system of FIG. 6 .
FIG. 8 . illustrates the variation of gas composition with time for the gasifier of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 , a schematic diagram illustrating one embodiment of a gasification system according to aspects of the present disclosure is shown. The gasifier system 100 comprises three primary components: a biomass feeding unit 102 ; a combustion chamber 104 ; and a separator 106 . These primary components may further comprise a number of subcomponents, which will be described in detail below. The system 100 is operable to accept biomass as an input product and provide useful gases as an output product. The producer gas may be a mixture of carbon monoxide (CO), carbon dioxide (CO 2 ), hydrogen (H 2 ), and possibly other gases. In one embodiment, the gasification system 100 operates to convert biomass material into the desired gases by means of pyrolysis and tar cracking. This result may be achieved by creating high temperatures within the combustion chamber 104 . This causes the biomass material to break down into a number of materials, including ash and gases.
The biomass feeding unit 102 accepts the biomass intake product for processing by the system 100 . Biomass materials suitable for use with the system 100 may include, but are not limited to, woodchips, sewage or sludge, and refuse from the processing of plant matter. The gasification system may also operate using input biomass from plants grown with the specific purpose of being fed into the gasification system 100 .
The biomass feeding unit 102 comprises a hopper 108 and an agitator 110 with an agitator drive unit 112 . The dimensions and specific shape of the hopper 108 may vary in accordance with the needs of the end user. In the present embodiment, the hopper 108 has a tapered cylindrical shape. The agitator 110 may be a bladed or impellor type agitator or another type of agitator suitable for the biomass used with the gasification system 100 . It is also understood that stirrers, conveyors, or other implements could be used to ensure ready delivery of biomass material into the gasifier 100 . In the present embodiment, where the agitator 110 is a rotational agitator, the agitator drive unit 112 may be selected according to the duty cycle and torque requirements necessary to agitate the chosen biomass material. Some embodiments will provide a variable speed agitator. The agitator may be selectively operable such that it operates only when needed to insure proper feeding of the biomass.
In the present embodiment, a screw drive 114 serves to move biomass from the hopper 108 to an airlock 118 . In the present embodiment, a screw drive 114 is powered by a screw drive powering unit 116 . The screw drive powering unit 116 may be pneumatic, electrical, or powered by another source. The screw drive may be selectively operable and/or of variable speed so that feeding of the biomass may be properly controlled. In other embodiments, the screw drive 114 may be replaced with other conveyance means, such as conveyor belt, a slip stick movement device, or another suitable conveyance.
The air lock 118 serves to control the intake of biomass from the hopper 108 to the rest of the gasification system 100 . The air lock 118 also serves to prevent back flow of the gases from combustion chamber 104 . The airlock 118 may be electrically or mechanically powered. The airlock 118 may be remotely controllable, such as with an electronic relay.
Beyond the airlock 118 is another screw drive 120 . The screw drive 120 is powered by another screw drive power unit 122 . These may be similar to the screw drive 114 and screw drive powering unit 116 . As before, in embodiments other than the one shown in FIG. 1 , the screw drive 120 , as well as the screw drive powering unit 122 , could be replaced with other conveyance means. In some embodiments, the airlock 118 , agitator 110 , and the screw drives 114 , 120 will operate in concert to ensure proper delivery of biomass to the combustion chamber 104 .
When the biomass material leaves the biomass feeding unit 102 , it is fed into the combustion chamber 104 . The combustion chamber 104 provides a number of additional steps in the gasification process, which will be described in more detail below. A biomass section 124 may be provided near the top of the combustion chamber 104 . In one embodiment, the biomass section 124 serves to guide or direct the entering biomass material into the remainder of the combustion chamber 104 .
A stirrer 128 may be provided starting at the biomass section 124 . The stirrer may proceed further into the depths of combustion chamber 104 . The stirrer 126 may be made from a suitably heat resistant material able to withstand high temperatures necessary in the combustion chamber 104 . Blades or other agitating means may be provided on the stirrer 126 . The stirrer 126 is powered by a stirrer drive unit 128 . The stirrer drive unit may once again be electrical, pneumatic, mechanical or powered by another source. The biomass section 124 may be cylindrical, conical, or may have another shape. In one embodiment, the shape of the biomass section 124 serves to feed biomass material at the appropriate speed and volume down into a tar cracking section 130 .
The tar cracking section 130 may be generally cylindrical in shape and may provide an inner chamber 135 , defined by an inner cylindrical wall 132 . The inner wall 132 and an outer wall 134 may define an annular outer chamber 133 . It can be seen that the inner wall 132 may also feature perforations 134 that aid in the heating of the biomass material. As solid biomass in the inner chamber 135 ispyrolysed, the gases may escape the inner chamber 135 through the perforations 134 in the inner wall 132 into the annular chamber 133 .
It can be seen that, in the embodiment shown, the stirrer 126 proceeds at least part of the way through the inner chamber 135 . In this way, stirring or agitation is provided starting at the biomass section and proceeding through at least a portion of the tar cracking section 130 . This reduces and/or eliminates hot spots that would prevent efficient pyrolysis and tar cracking within the combustion chamber 104 .
In the present embodiment, the combustion chamber 104 is heated in part by the combustion of propane. The propane heating may only be necessary to initiate the gasification process. In the present embodiment, propane enters through the fuel inlet 136 into the combustion chamber 104 where it may be ignited to produce heat. Although propane is used in the present example, it is understood that other fuel sources may be utilized, including but not limited to, natural gas, refined fuels, and other petroleum products.
It may be important to carefully control oxygen content within the combustion chamber 104 . An air inlet 138 is provided for oxygenating the environment of the combustion chamber 104 . An additional function of the air inlet 138 may be to provide heated air for furthering the gasification processes of the system 100 . Some embodiments will provide a heater 140 for preheating the air entering the combustion chamber 104 . The heater 140 may be gas or electrical powered or, in some embodiments, may be based off of the waste heat generated by another outside process. In some embodiments, the heater 140 will preheat the air to up to 300° C. or greater. A compressor 142 may also be provided for delivering the air into the combustion chamber 104 at the appropriate pressure. Pressurizing the ambient air will also heat the air to a certain degree, which may be useful in the gasification process. The compressor 142 can be electrical, pneumatic, or powered by another source. In the present embodiment, the heater 140 follows the compressor 142 resulting in higher efficiencies resultant from the heater 140 operating on compressed, and therefore hotter, air.
Various components of the system 100 , may be insulated for increased efficiency or productivity. For example, the air inlet 138 may be insulted. Similarly, all or a portion of the combustion chamber 104 may be insulated. In one embodiment, a ceramic wool blanket insulation (not shown) of about 25 mm thickness will be utilized. In other embodiments, different materials that are suitably heat resilient may be utilized. Additionally, the thickness of any insulation used may be varied based upon a number of factors including the desired reaction temperature, the ambient air temperature, efficiency concerns, and others.
Below the tar cracking section 130 is a char gasification section 144 . In the present embodiment, the char gasification section 144 is separated from the tar cracking section by an annulus 146 . This component may be optional depending upon the nature of the biomass material being utilized. In the present embodiment, the annulus 146 serves to guide the partially gasified biomass into the char gasification section 144 .
The biomass material in the char gasification section 144 falls down onto a grating 148 . The grating 148 serves as a separation step to separate the solid material from the gases created in the combustion chamber 104 . It can be seen that the raw gases and ash are allowed to escape via a conduit 152 and travel to the separator 106 . The remaining solid biomass material will remain trapped by the grating 148 where additional char gasification will occur. As the biomass further gasifies, the ash and gases produced will pass through the grating and out the conduit 152 .
It can be seen in FIG. 1 that the biomass section 124 , the tar cracking section 130 , and the char gasification section 144 may be arranged in a generally vertical fashion. The present embodiment provides the tar cracking section 130 in between the biomass section 124 and the char gasification section 130 . In this configuration, gravity may serve to feed the biomass through the combustion chamber resulting in down draft type gasification process. The combustion and gasification in the combustion chamber 104 may serve to create swirls, vortices, and other cyclonic gas flows. These may be controlled and/or aided by the stirrer 126 and perforations 133 in the inner chamber wall 132 of the tar cracking section 130 . This serves to prevent cold spots in the combustion chamber 104 , particularly as the size of the process is scaled up.
The configuration of the combustion chamber 104 also helps to ensure substantially complete transformation of the biomass material into gases and ash. The gases will include producer gas and possibly waste gas. The ashes will contain substantially no organic material. Nevertheless, as a practical consideration, means may be provided for clearing any solid material captured on the grating 148 that is not consumed by char gasification. In one embodiment, this may be an access portal 150 located near the grating 148 on the char gasification section 144 of the combustion chamber 104 . The access portal 150 may also allow for servicing, inspection, and/or replacement of the grating 148 and other components on the interior of the combustion chamber 104 .
The separation section 106 provides a separator 154 for separating the production gas from the ash in the raw gas stream coming from the conduit 152 . In one embodiment, the separator 154 is a cyclonic separator, but other separators may be utilized. The separator may be mechanical and may be electrically, pneumatically, or otherwise powered. The separated production gas is removed by the outlet 156 . The present embodiment illustrates a burner 158 that consumes the production gas coming from the outlet 156 . Thus, heat and other power may be provided for another process. However, it is understood that the production gas may be stored, utilized in a different manner, or further refined downstream of the gasification system 100 . A storage chamber 160 is provided for catching and/or holding the ash from the separator 154 . The ash may be useful in other processes and can therefore be retained until needed. In the present embodiment, an access portal 162 is provided for periodically removing the ash from the storage chamber 160 . It is understood, however, that other means may be utilized, such as conveyor belts or screw drives.
Referring now to FIG. 2 , a schematic diagram illustrating one embodiment of a gasification combustion chamber for use with the gasification system of FIG. 1 is shown. It should also be noted that this combustion chamber may also be utilized with the gasification system of FIG. 6 discussed below. It can be seen that the combustion chambers 200 and 104 are similar. Once again, a three-section embodiment is shown. The sections or chambers include the biomass section 124 , the tar cracking section 130 , and the char gasification section 144 . A stirrer 126 is provided, driven by a stirrer drive unit 128 . The fuel inlet 136 is shown, along with the air inlet 138 . A grating 148 is provided near the bottom end of the char gasification section 144 . Gases and ash escape through the gas conduit 152 . It will be appreciated that the combustion chamber 200 may be utilized in the gasification system 100 of FIG. 1 , directly replacing the combustion chamber 104 illustrated in FIG. 1 .
As has been described, in one embodiment biomass is provided to the combustion chamber 200 through a biomass feeding unit. Biomass enters the combustion chamber 200 through an inlet 202 . In FIG. 2 , a biomass column 204 is illustrated to show one possible route for the biomass material through the combustion chamber 200 . It can be seen that the stirrer 126 may serve to stir the biomass 204 . As before, propane gas is introduced through the inlet 136 . In the present embodiment, the propane is supplied near the top of the tar cracking section 130 , and is used only for initial firing at start up of the process.
The tar cracking section 130 is once again formed by inner cylindrical walls 132 and an outer cylindrical wall 134 . An inner chamber 135 is bounded by the inner wall 132 and an annular chamber 136 is formed between the inner wall 132 and outer wall 134 . In the present embodiment, the entirety of the inner chamber 132 is provided with perforations 134 . Various degrees of perforation of the inner chamber 132 may be utilized depending upon the raw biomass material being utilized. Some embodiments may provide for an adjustment of the degree of perforation using a sleeve or other means, for example. In the present embodiment, tar loaded pyrolysis gases are allowed to escape from the biomass 204 column through the perforations 134 where they are mixed with preheated air from the air inlet 138 . The pressurized gas entering the tar cracking section 130 provides high temperature turbulence and swirling combustion flows, allowing tar cracking to occur.
The high temperature combustion products being produced in the tar cracking section 130 feed through the annulus 146 into the char gasification section 144 . In the present embodiment, the char gasification section 144 provides for additional biomass decomposition by char gasification reactions. In some embodiments, temperatures of up to 1200° C. are attained in the char gasification section 144 .
It can thus be appreciated that biomass entering the combustion chamber 200 will undergo a continuous process whereby the gasification process begins as early as the biomass section 124 . As the biomass is consumed, it is allowed to fall with the aid of the stirrer 126 into the tar cracking section where a majority of the pyrolysis of the process may occur. As the partially consumed biomass exits the tar cracking section 130 , it is allowed to fall downward into the gasification chamber 144 where it may land on the grating 148 . In some embodiments, the reaction of remaining biomass in the column 204 continues on the grating 148 . Gases and heat escaping downward through the combustion chamber 104 and out through the conduit 152 provide energy for the char gasification process on the grating 148 . Thus, a substantially complete reduction process will occur such that gases and essentially inorganic material, or ash, are allowed to flow freely through the conduit 152 .
Table 1 shows the characteristics of pine wood pellets that may be used as a feedstock (biomass) for operation of the gasification system of the present disclosure. Table 2 illustrates a summary of a number of gasification tests conducted utilizing a system constructed in accordance with FIG. 1 . The table includes the temperatures reached by various locations within the system 100 , as well as the gases produced in percentage by volume thereof. It can be seen that, in some of the tests, tar content and particulates were measured. Efficiency and mass balance percentages are also shown. The mass balance percentages may not add up to exactly 100 due to measurement limitations and rounding errors in equipment.
Referring now to FIG. 3 , an illustration of an exemplary temperature profile of a downdraft gasifier constructed according to aspects of the present disclosure is shown. The measurements of FIG. 3 were taken with a gasifier built according to the present disclosure. Referring also to FIG. 4 , the pressure over time of various output gases from the gasifier is shown. With reference to FIGS. 3 and 4 , it can be seen that within 60 min from system start time, the gasifier system operation was stabilized. FIG. 4 reveals that, throughout the test period of three hours, concentration levels of all gases were stable. The present embodiment produces gases with a heating value in the range of 1277 to 1423 kcal/m 3 . Volumetric CO, H 2 , and CO 2 concentrations are in the range of 21-23%, 11-13%, and 13-13.5% percent, respectively. Tar cracking zone temperatures were maintained close to 1000° C. Hot gas efficiency ranged from 63 to 81 percent. Average producer gas flame temperatures were approximately 780° C. Tar and particulate contents in the raw producer gas were in the range of 5 to 12 g/m 3 and 0.4 to 0.45 g/m 3 , respectively. It can be seen that the results corresponding to the performance of a gasifier constructed according to the present disclosure are comparable to the performance of a conventional throat type downdraft gasifier. This relationship is illustrated for reference in Table 3.
Referring now to FIG. 5 , a flow diagram illustrating one method of a gasification process according to the present disclosure is shown. FIG. 5 illustrates a simplified version of one gasification method that may be accomplished by the systems of the present disclosure. At step 502 , biomass is input to the system. At step 504 , the biomass will be stirred and heated. Stirring could be done in a biomass chamber, for example. Heating could be accomplished by a propane flame and/or heated air, or by other means. Pyrolysis begins at step 506 . However, it is understood that stirring and heating may continue even as pyrolysis occurs.
At step 508 tar cracking occurs. As before, it is understood that pyrolysis may still be occurring when tar cracking has begun. Stirring and heating of the biomass as shown at step 504 may also still be occurring. With reference back now to FIG. 1 , it can be seen in the combustion chamber 104 of the system 100 that stirring and heating at 504 , pyrolysis at step 506 , and tar cracking at step 508 may be simultaneously and/or continuously occurring.
Char gasification begins at step 510 . Although char gasification is illustrated as the last of the actual gasification steps, referring again to FIG. 1 , it will be clear that the char gasification at step 510 can occur simultaneously with stirring and heating at step 504 , pyrolysis at step 506 , and/or tar cracking at step 508 .
Following the reduction of substantially all of the biomass through pyrolysis, tar cracking, and/or char gasification, the raw gases will be separated from the ash contained therein at step 512 . Following removal of the ash at step 512 , the gas may be output at step 514 . As previously described, the output gas may have a number of uses, such as immediate consumption, storage, and/or further refining.
Referring now to FIG. 6 , a schematic diagram illustrating another embodiment of a gasification system according to aspects of the present disclosure is shown. It can be seen that the system of FIG. 6 is similar in some regards to the system of FIG. 1 described above. Differences between the embodiments will be discussed herein. The gasifier system 600 comprises a biomass feeding unit 601 , a multi-stage combustion chamber 614 ′; and a separator 634 . Combustion chamber 614 has an inner lining of high temperature refractory. The biomass feeding unit 601 comprises a hopper 602 and a stirrer 604 . The hopper 602 of the present embodiment is cylindrical in shape.
A screw drive 604 serves to move biomass from the hopper 602 to an airlock 606 . As with previous embodiments, the air lock 606 serves to control the intake of biomass from the hopper 601 to the rest of the gasification system 600 and serves to prevent unwanted gases (e.g., air) from entering the combustion chamber 614 . Another screw drive 608 delivers biomass to the combustion chamber 614 . As with previous embodiments, the screw drives could be replaced with other conveyance means and may be air powered, electrically powered, or power by other mechanical means.
In the present embodiment, the gasification reactor or combustion chamber 614 comprises a biomass section 610 near the top, a pyrolysis and tar cracking (PTC) zone 622 near the middle, and a char gasification chamber 624 near the base. Similar to previous embodiments discussed with regard to FIGS. 1 and 2 , the PTC zone 622 comprises a twin cylinder unit extended downward to the top of the gasification chamber 624 with an annular space between the cylinders. The inner cylinder is perforated and holds the biomass column. Tar-loaded pyrolysis gases enter into the annular space. Air (possibly compressed and/or heated as in FIG. 1 ) enters an inlet 620 and is tangentially mixed with the pyrolysis gases. High temperatures in the PTC zone 622 also facilitate biomass pyrolysis. Propane gas, or other fuel, may be supplied at a gas inlet 618 near the top of the PTC zone 622 for initial firing.
A suitably heat resistant stirrer 612 may be provided starting at the biomass section 605 and proceed into the PTC zone 622 . It can be seen that, in the embodiment shown, the stirrer 126 proceeds at least part of the way through the inner chamber 135 . In this way, stirring or agitation is provided starting at the biomass section 610 and proceeding through at least a portion of the PTC zone 622 . This reduces and/or eliminates hot spots that would prevent efficient pyrolysis and tar cracking within the combustion chamber 104 . Various components of the system 600 may also be insulated for increased efficiency or productivity. For example, in the present embodiment, the gasification reactor 614 , piping, and a cyclone separator 634 are insulated with a 25-mm thick ceramic wool blanket.
The char gasification section 624 may be separated from the PCT zone 622 by an annulus 623 . In the present embodiment, the annulus 623 serves to guide the partially gasified biomass into the char gasification section 624 . In the present embodiment, the biomass material in the char gasification section 624 may be stirred by a stirrer 626 . This may help break up any large chunks of biomass material remaining as the biomass falls down onto a grating 628 . The grating 628 serves as a separation step to separate the solid material from the gases created in the combustion chamber 104 . The grating 628 may be a wire mesh and may also be provided with a rotating scraper 630 . The rotating scraper may provide a circular opening in the center (not shown). Remaining biomass material may be further reduced to gases and ash on the grating 628 .
Raw gases and ash will pass through the grating 628 . Ashes will tend to fall into the ash chamber 632 while gases may be drawn into the cyclonic separator 634 . Here, particulates remaining in the gas stream may be removed. Separated production gas may be consumed by a burner 158 . Thus, heat and other power may be provided for other processes. However, it is understood that the production gas may be stored, utilized in a different manner, or further refined downstream of the gasification system 600 .
A tar and particulate measurement system 636 may be provided for monitoring the gases leaving the cyclonic separator 634 . Further testing of the producer gas can be conducted using a device such as a gas chromatograph. In order to properly monitor and control the system 600 , various other sensors may be placed at needed locations. Without limitation, these may include temperature and pressure probes, mass flow meters, thermocouples, and rotational sensors.
Ash that is collected in the ash chamber 632 may be removed by screw conveyor 640 to a remote ash storage chamber 642 . Here the ash may be stored until discarded or removed for use in another process.
The embodiment of FIG. 6 should increase CO and H 2 concentrations and reducing CO 2 relative to other gasification methods. For testing of the device shown in FIG. 6 , switchgrass, at approximately 11.6% dry basis moisture content, was chopped using a Haybuster H-1000 tub grinder (DuraTech Industries International, Inc. Jamestown, N.D.) using a screen with a 25-mm hole size. For bulk density determination, the material was poured into a 473-ml container from 100 mm above the container. The bulk density was determined by dividing the weight of the material by the container volume. Biomass proximate and ultimate analyses were performed by Hazen Research Inc, Golden, Colo.
Test preparation started with loading 5 kg of wood charcoal onto the grate 630 . The gasification reactor 614 was then completely filled with chopped switchgrass. The hopper 602 was also kept full with the biomass. The gasifier 600 was preheated using propane for about five minutes. When the temperature in PTC zone 622 reached approximately 600° C., preheating was discontinued. The desired air flow was then set. Within thirty minutes, the reactor temperature profile stabilized.
During each test, biomass fuel level in the gasification reactor 614 was maintained by intermittently operating the biomass feeding system 601 . Reactor temperature profile, temperature of the producer gas at the exit of the cyclone reactor and that of the flame, pressure drops across the gasification reactor and the whole system, air flow rate, and amount of biomass loaded before and during the tests were closely monitored. The maximum test duration was six hours. Producer gas sampling began once the system was stabilized as indicated by the reactor temperature profile. For gas analysis, samples were taken every 10-15 minutes. At the end of each experiment, solid residues remaining in the reactor and in the particulate chamber and the biomass remaining in the hopper were quantified to estimate the fuel consumption rate and to determine the overall mass balance. Gas flow rate was determined by a nitrogen balance. The gas calorific values were determined using the volumetric gas composition values from gas chromatograph and the theoretical heating values of all the combustible components. Gasifier efficiencies, equivalence ratios and mass balances were calculated as follows:
CGE=[PCE /( DBE+ASE )]*100 Eqn. 1
HGE=[(PCE+PSE )/( DBE+ASE )]*100 Eqn. 2
ER =AIR/( DBIR*STADB ) Eqn. 3
Where,
CGE=Cold gas efficiency, %
HGE=Hot gas efficiency, %
ER=Equivalence ratio
PCE=Chemical energy in dry producer gas, kcal/h
PSE=Sensible energy in dry producer gas, kcal/h
DBE=Dry biomass energy, kcal/h
ASE=Hot air sensible energy, kcal/h
AIR=Air input, Nm 3 /h
DBIR=Dry biomass input, kg/h
STADB=Stochiometric air requirement for dry biomass, Nm 3 /kg of dry biomass
Mass balance, %=(Total mass out/Total mass in)*100 Eqn. 4
Table 4 shows the characteristics of switchgrass used in the study. Chopped switchgrass is a low bulk density biomass with ash content and elemental composition comparable to most of the crop residues. Low bulk density poses major challenge to ensure proper material flow in the reactor and the hopper. Agitators have been used to facilitate the material flows in the biomass hopper and the gasification reactor.
The major operating parameters and results of the gasification tests are presented in Table 5. FIGS. 7 and 8 show typical cases of temperature and gas composition profiles. Within one hour from system start-up, the gasifier operation was stabilized. The tar cracking temperatures were between 1003 and 1110° C. Gas components of greatest interest (volume basis) were CO: 19.2-24.4%, H 2 : 9.7-12.0%, CO 2 : 7.9-13.7% and CH 4 : 2.5-4.5%. Dry product gas yield ranged from 1.7 to 1.8 Nm 3 /kg dry biomass. Specific gasification rates varied from 507 to 736 m 3 /h of dry gas per square meter combustion zone area. Hot gas and cold gas efficiencies were: 63-89% and 52-78%, respectively. Average producer gas flame temperatures were around 8000C. The lower heating value of the gas ranged from 1160 to 1673 kcal/Nm 3 .
Among the four levels of specific air input rates (kg of air/h-sq. m of combustion zone area) tested to date, 542 kg/h-sq. m of combustion zone area resulted in the highest system performance: average values for hot gas and cold gas efficiencies of 89% and 72% respectively; lower heating value of gas: 1566 kcal/Nm 3 ; and CO, H 2 and CO 2 concentrations: 23%, 12% and 9%, respectively. The corresponding average specific gasification rate was 663 cu. m dry gas/h-sq. m of combustion zone area. As the specific air input rate increased to 647 kg/h-sq. m of combustion zone area, CO 2 concentration increased 14% while the CO and H 2 concentrations decreased (19 and 10% respectively). The average lower heating value of gas also decreased up to 1160 kcal/Nm 3 . The corresponding specific gasification rate was 736 cu. m dry gas/h-sq. m of combustion zone area. Specific air input rate of 542 kg of air/h-sq. m of combustion zone area provided optimal reaction environment in the gasifier for CO 2 and water vapor reactions with carbon, and as a result produced gas with higher levels of CO and H 2 concentrations. At this level of specific air input, the gas tar and particulate content at the gasifier exit were: 18 and 2.5 g/Nm 3 , respectively. For wood pellets based gas these values were 5-12 g/Nm 3 and 0.4-0.45 g/Nm 3 , respectively [4].
Lower bulk density and higher volatiles in the chopped switchgrass as compared to wood pellets, is one reason for higher levels of tars. Another major reason for higher levels of tars in the gas is the shifting of high temperature zone downward below the PTC section 622 because of the low density nature of the chopped biomass. In general, the system performance was consistently good regarding CO and H 2 concentrations and gasification efficiencies as shown in Table 5. The differences in the mass balance closure figures is attributed to measurement errors in collection and quantification of the incoming and outgoing streams of the gasifier system.
Among the four levels of specific air input rates, a level of 542 kg/h-sq. m of combustion zone area resulted into highest performance: average values for hot gas and cold gas efficiencies of 82% and 72% respectively; lower heating value of gas: 1566 kcal/Nm 3 ; and CO, H 2 and CO 2 concentrations: 23%, 12% and 9%, respectively. The corresponding average specific gasification rate was 663 cu. m dry gas/h-sq. m of combustion zone area.
As the specific air input rate increased to 647 kg/h-sq. m of combustion zone area, CO 2 concentration increased 14% while the CO and H 2 concentrations decreased 19 and 10% respectively. CO and H 2 % increased up to 24% & 12% (by volume), respectively while CO 2 % decreased from earlier concentration of 18% to 8%.
TABLE 1
Wood pellet characteristics
Proximate,
(weight %, dry basis)
Moisture content
7.5 ± 0.1
Volatile matter
82.2 ± 0.6
Fixed carbon
17.6
Ash
0.2 ± 0.03
Higher heating value, kcal/kg a
5075
Ultimate a
(weight %, dry basis)
Carbon C
52.13 ± 1.7
Hydrogen H
6.36 ± 0.3
Oxygen O
41.23
Nitrogen N
0.07 ± 0.03
Sulphur S
0.01
Diameter (mm)
6.0
Length (mm)
10-35
Bulk density (kg/m 3 )
660
a BIOBIB. 1992. A database for biofuels. Available at: www.vt.tuwien.ac.at/Biobib/biobib.html. Accessed 8 May 2006.
TABLE 2
Summary of typical gasification operation
Test 1
Test 2
Test 3
Test 4
Equivalence ratio
0.18
0.21
0.23
0.17
Fuel feed rate, kg/h
17.0
14.8
13.0
18.1
Input air temperature, C.
216 ± 4
205 ± 3
216 ± 17
219 ± 4
Tar cracking zone (TCZ)
854 ± 43
896 ± 38
866 ± 48
800 ± 48
temperature, (Ave.), C.
TCZ temp. (Max.), C.
966
1001.7
1002
975
Char gasification (CG)
706 ± 38
770 ± 22
556 ± 208
708 ± 50
chamber top, Ave., C.
CG chamber top, (Max), C.
793
819
786
844
CG chamber mid, (Ave.) C.
742 ± 27
790 ± 26
607 ± 181
731 ± 25
CG chamber mid, (Max.) C.
789
827.7
768
769
Gas temperature after cyclone
352 ± 4
383
350 ± 7
356 ± 26
separator, C.
Flame temp. (Ave.), C.
770 ± 25
780 ± 31
777 ± 30
777 ± 24
Flame temp. (Max.), C.
813
843.4
829
829
Pressure drop across
11.0 ± 0.6
12.0 ± 0.4
10.4 ± 0.4
10.4 ± 0.3
gasifier, Inch of water
Gas composition, % vol.
CO
22.7 ± 0.9
21 ± 0.9
21.2 ± 2.1
21.6 ± 1.3
H 2
10.9 ± 1.6
11.9 ± 2.3
11.6 ± 1.7
12.4 ± 2.2
CH 4
3.4 ± 0.7
3 ± 0.7
3.1 ± 0.8
3.6 ± 1.1
CO 2
13.4 ± 0.9
13.3 ± 1.1
13.4 ± 0.6
13.1 ± 1.0
N 2
48.8 ± 1.7
50.3 ± 1.8
50 ± 2.1
48.3 ± 3.5
C 2 H 2
ND*
0.1 ± 0.2
ND*
0.2 ± 0.4
C 2 H 4
0.5 ± 0.1
0.4 ± 0.2
0.5 ± 0.1
0.7 ± 0.3
C 2 H 6
0.2 ± 0.3
0.1 ± 0.1
0.1 ± 0.3
0.1 ± 0.1
LHV gas (kcal/Nm 3 ) †
1369
1277
1293
1423
Dry gas yield (Nm 3 /kg)
1.69
1.88
2.16
1.60
Tar content, g/Nm 3
Not
7.5
5
12
measured
Particulates, g/Nm 3
Not
0.45
0.4
0.4
measured
Hot gas efficiency, %
63.2
71.6
80.7
60.5
Cold gas efficiency, %
56.3
63
71.9
54
Mass balance, %
98
101
105
94
*Not detected;
† Nm 3 refers to a cubic meter of gas at a standard temperature of 0° C. and pressure of 1 atm
TABLE 3
Gasifier performance comparison with other published
data on conventional downdraft gasification systems
Air-to-fuel
ratio,
Tar cracking
% Volume
Feedstock
Nm 3 /kg
Temp, ° C.
CO
H 2
Tar, g/Nm 3
Hazelnut
1.46
1050
21
13.1
3.0
shells
Sewage
2.3
1077
10.6
10.9
6.26
sludge
Wood chips
Equivalence
1000
24
14
No data
ratio of 0.38
Pine wood
Equivalence
1000
21
12
5.0
pellets (this
ratio of 0.23
study)
TABLE 4
Switchgrass characteristics
% db
Moisture content
11.6
Carbon
49.67
Hydrogen
5.27
Oxygen
40.31
Nitrogen
0.57
Sulphur
0.07
Ash
4.11
Lower heating value, kcal/kg
4118
Bulk density, kg/m 3
138
TABLE 5
Summary of results for gasification tests
Specific air input rate,
437
542
542
647
kg of air/h-sq. m
Specific gasification rate,
507
639
688
736
cu. m dry gas/h-sq. m
Equivalence ratio
0.22
0.22
0.20
0.23
Fuel feed rate, kg/h
12.8
16.7
18.4
19.7
Air temperature, C.
16.0 ± 0.8
10.1 ± 1.1
25.0 ± 3.0
20.0 ± 2.0
Tar cracking temp. (CG1), C.
1078 ± 101
1050 ± 76
1003 ± 135
1110 ± 107
CG1 temperature (max.), C.
1261
1169
1318
1336
Temperature below grate, C.
355 ± 91
374 ± 120
360 ± 57
441 ± 69
Flame temperature, C.
717 ± 49
768 ± 34
764 ± 50
813 ± 30
Flame temperature (max.), C.
791
815
920
871
Pressure drop across
4 ± 3
9 ± 5
15 ± 6
16 ± 8
gasifier, cm of water
CO, % vol.
23.5 ± 3.2
24.4 ± 1.3
22.1 ± 4.3
19.2 ± 1.6
H 2 , % vol.
10.9 ± 1.9
11.4 ± 0.7
12.0 ± 1.4
9.8 ± 1.2
CH 4 , % vol.
3.9 ± 0.6
3.3 ± 0.5
4.5 ± 0.2
2.5 ± 0.7
CO 2 , % vol.
7.9 ± 1.9
7.8 ± 1.1
11.2 ± 0.8
13.7 ± 0.4
N 2 , % vol.
52.9 ± 1.2
52.1 ± 2.1
48.5 ± 3.5
54 ± 2.4
LHV gas, kcal/Nm 3
1437
1458
1673
1160
Dry gas yield, kg/kg of dry
1.8
1.8
1.7
1.7
biomass
Hot gas efficiency, %
79
75
89
63
Cold gas efficiency, %
69
65
78
52
Mass balance, %
89
87
93
89
Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims. | A downdraft gasifier is disclosed. The gasifier includes a biomass section that accepts and stirs raw biomass materials, a pyrolysis and tar cracking section having an inner cylinder for receiving biomass and an outer surrounding cylinder for gases from the biomass, and a char gasification section for receiving biomass and gases from the pyrolysis and tar cracking section. The char gasification section provides a grating and scraper for passing gases and ash and retaining biomass for char gasification on the grate. | 5 |
[0001] The present application hereby claims priority under 35 U.S.C. §119 on German patent application number DE 103 36 734.9 filed Aug. 11, 2003, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention generally relates to a fastening device for a probe inside a human or animal body.
BACKGROUND OF THE INVENTION
[0003] An endoscope is used to examine the upper and lower gastrointestinal tract, which records individual images of the surroundings and transmits them to an external image processor. Lesions such as tumors can be identified and located on the basis of such images.
[0004] In addition to examinations undertaken in the gastrointestinal tract, endoscopy is also used in other hollow organs and cavities in the human or animal body. Examples of this include examinations of blood vessels, the abdominal cavity—which is typically undertaken by means of a small incision to the navel—or an examination of the lungs.
[0005] Cordless or wireless endoscopic probes are currently used for the care of patients undergoing endoscopic diagnosis. These are capsules, which include specific devices such as an image recorder with a transmitter for transmitting the recorded image data. To aid navigation, a magnet can often be found in such capsules, also referred to as endorobots, which in turn enables control by way of an external magnetic field.
[0006] The capsule endoscope or endorobot is preferably inserted into the gastrointestinal tract orally or anally. In hollow organs or cavities in the body that are closed off externally, the endorobot can be inserted through a small incision.
[0007] Although lesions can be successfully identified and located with the aid of endoscopy, it still remains difficult for a surgeon to relocate the identified position during subsequent examinations or interventions. Since a human intestine can reach up to 11 m in length, and has no landmarks and is constantly moving, it is extremely difficult for a surgeon to relocate a previously identified lesion, i.e. during preparation for an operation.
[0008] In principle, it is possible to mark a lesion by way of chromoendoscopy and intravital staining. With the techniques, a colored solution is applied to the mucosa of the gastrointestinal tract, causing specific discoloration of mucosa modified by disease. The intracoporal position of the marking thus applied however fails to permit extracorporal location of the marked position.
[0009] For location purposes, cordless probes can be guided to the previously identified or marked position, the position of the probes inside the body being easily located or detected from the outside. The probes used are generally the endorobots, which in some instances were used for prior identification and possibly also the marking of the lesion, i.e. as endomarkers.
[0010] One disadvantage here is that after positioning, in particular during the time between diagnosis and operation, the probes can change their position. For example, in blood vessels, the probes move with the flow of blood. In the gastrointestinal tract, both the movement of the organ itself and also the substances transported therein result in the probe moving position over time.
[0011] Since at least one hour generally passes between the diagnosis and subsequent operation, it is a common occurrence for the probe to have moved from the originally marked position by the start of the operation. The practical benefit of a corresponding use of surgical or diagnostic aids, such as for example probes or endorobots, is thus reduced.
SUMMARY OF THE INVENTION
[0012] An object of an embodiment of the present invention is thus to provide a way/device to prevent the displacement of an initially positioned surgical or diagnostic medical aid, such as a probe.
[0013] An object may be achieved by the use of a fastening device.
[0014] According to an embodiment of the present invention, a fastening device is proposed for anchoring a surgical or diagnostic medical aid in the tissue of a human or animal hollow organ. The fastening device includes an anchor head, which is configured to penetrate the tissue, a driving device for driving the anchor head into the tissue and a trigger device for triggering the driving of the anchor head into the tissue.
[0015] With an inventive fastening device, a surgical or diagnostic medical aid can be securely anchored in a previously identified position, in order to prevent subsequent displacement of the aid in a reliable manner.
[0016] In order to prevent the driving force acting on the anchor head before the fastening device is triggered, the trigger device is expediently integrated in the driving device.
[0017] Advantageous multiple use can be achieved by using a spring element as the driver in the driving device. Alternatively, the driving device can include a gas pressure element as the driver, thereby achieving a large driving force with a small structure.
[0018] The driving unit is preferably equipped with a runner to hold the anchor head to ensure effective transmission of the driving force to the anchor head.
[0019] At least one anchoring element is configured on the anchor head to prevent the anchor head detaching from the tissue after penetration. This is expediently in the form of a barb. Maintaining a small cross-sectional area of the anchor head facilitates the penetration of the anchor head into the tissue. In addition, the at least one anchoring element is expediently configured as an expansion device with at least one arbor, whereby the arbor can be opened out by way of an opening device, or can be configured as a self-expanding arbor, when subject to tensile force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Exemplary embodiments of the invention will be explained in more detail below with reference to the drawings, in which:
[0021] FIG. 1 a shows an endorobot with an inventive fastening device in standby position
[0022] FIG. 1 b shows the endorobot in FIG. 1 a anchored to a tissue
[0023] FIG. 2 shows a first embodiment of an inventive fastening device
[0024] FIG. 3 shows a second embodiment of an inventive fastening device and,
[0025] FIG. 4 details the different embodiments of an anchor head according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] FIG. 1 shows the endorobot 1 configured as a wireless endoscope. The endorobot 1 is in the form of a consumable capsule; its shell 2 is manufactured from a biocompatible material which is resistant to the digestive secretions occurring in the gastrointestinal tract. An inventive fastening device 3 is arranged within the capsule shell 2 adjacent to one end.
[0027] Other functional components of the endorobot 1 are housed in the remaining space within the capsule 2 . Typically these devices include an optical mapping system 7 for producing images of the surroundings of the endorobot 1 . A central electronic signal processor 4 transforms optical image signals to electrical image signals and controls the endorobot. It is equipped with an antennae device 5 for wireless communication with an external signal processor. A permanent magnet 6 within the capsule shell enables the orientation or guiding of the endoscopic probe 1 from outside a human or animal body.
[0028] The inventive fastening device 3 includes three basic components, namely a driving device 8 , an anchor head 9 , and a trigger device 10 . The trigger device 10 can be controlled by way of electronic signal processor 4 . In the schematic representation in FIG. 1 , the trigger device 10 is configured as a blockade device for the exit of the anchor head 9 from the capsule shell 2 .
[0029] Alternatively the trigger device can also be integrated in the driving device 8 in such a way that the driving force developed therein only acts on the anchor head 9 after the trigger device 10 has been triggered. The end of the anchor head 9 to be sunk into the tissue in this instance extends to or close to the one end of the capsule shell 2 . To avoid contamination of the interior of the endorobot, this one end can additionally be equipped with a sealing mechanism, which opens synchronously with the trigger device 10 . Instead of the sealing mechanism, the wall of the capsule shell can also be configured to be so thin at this point that it can be penetrated when the anchor head 9 is driven forward.
[0030] To fasten the endorobot 1 to a previously determined position in the body of a patient, a corresponding signal is transmitted by a wireless communication to the signal processor 4 . This activates the trigger device 10 and thus enables the driving force stored in the driving device 8 to act on the anchor head 9 . As a result of the driving force acting on it, the anchor head 9 moves at high speed towards the tissue wall 12 facing it and penetrates its surface.
[0031] To prevent the anchor head 9 becoming detached from the endorobot 1 , it is preferably connected by way of a flexible connection 11 , for example a cord or a flex or similar, to part of the endorobot 1 , for example the capsule shell 2 or a device within the endorobot 1 . In order that the action of a tensile force on the anchor head 9 does not cause said anchor head 9 to detach from the tissue wall 12 , an anchoring element 13 is configured thereon.
[0032] In the simplest case as shown in FIG. 2 , the driving device 8 is configured in the form of a spring element 14 , for example a spiral spring. In the initial state the spring element 14 is tensioned. The tension is maintained by the trigger device 10 in its closed state and cannot be transmitted to the anchor head 9 . When the trigger device 10 opens, the spring element 14 can become slack, whereby the energy thereby released is transmitted to the anchor head and ejects this from the capsule shell 2 of the endorobot 1 .
[0033] In an alternative embodiment, which is shown in FIG. 3 , the driving force is provided by a pressurized gas 16 in a pressure vessel 15 . The trigger device 10 seals off the gas chamber of the pressure vessel 15 from the outside. When triggered, the trigger device 10 releases the opening of the pressure vessel 15 , so that the gas pressure acts directly on the anchor head 9 and ejects the anchor head from the endorobot 1 . For this purpose, the anchor head preferably has a shank-like segment 17 , which is arranged in the runner 18 connected to the pressure vessel in the standby position.
[0034] FIG. 3 shows several preferred embodiments of an anchor head 9 for use in an inventive fastening device 3 . In order to prevent the anchor head 9 being drawn out of the tissue wall 12 when subject to a tensile force, one or more anchoring elements 13 are arranged adjacent to its front free end, which is preferably configured as a point 19 . The anchoring elements 13 can be fixed e.g. in the form of a barb, or movable, e.g. such as expansion devices 21 or 22 .
[0035] The anchoring element 13 is expediently configured as an arbor in the form of a barb 20 , as shown in the anchor head detail in FIG. 3 a. The front edge of the barb 20 preferably tapers to a point so that no appreciable resistance counteracts the penetration of the anchor head 9 into the tissue. The rear flank of the barb 20 is preferably configured as level so that the barb abuts firmly against the tissue when subject to tensile loading.
[0036] To keep the level of work required for the anchor head 9 to enter a tissue wall 12 as low as possible, the anchoring element 13 can also be configured in the form of an expansion device 21 or 22 as shown in FIGS. 3 b and 3 c. In standby mode, i.e. before the fastening device 3 is triggered, an arbor 21 a or 22 a of the expansion device 21 or 22 is disposed on the shank-like part of the anchor head. This is the rest position of the expansion device. In the tissue wall, the moveable arbor disposed on the anchor head 9 expands away from this to enable it to grip the tissue in the same way as a barb.
[0037] In a first embodiment 21 of the expansion device, the arbors 21 a are opened out by way of an opening device 23 from their rest position, in order to form an open, acute angle in relation to the rear end of the anchor head 9 . The opening device 23 preferably only opens the arbor 21 a out after penetration of the anchor head into the tissue in order to keep its penetration resistance to a minimum. This can be achieved by triggering the opening device by means of a tensile stress on the flexible connection 11 .
[0038] The alternative embodiment 22 of an expansion device shown in FIG. 3 c includes one or several arbors 22 a, which are each arranged in a rotatable manner in a cavity in the anchor head 9 . The pointed ends of the arbors oriented towards the rear end of the anchor head however protrude somewhat out of the cavity. During penetration of the anchor head 9 into a tissue wall 12 , they rest against this. If tensile force is exerted on the anchor head 9 , the pointed ends of the arbors push into the surrounding tissue and stand up. The anchor head is thereby securely anchored in the tissue.
[0039] The effectiveness of the inventive fastening device 3 for endorobots 1 is not limited to penetration by the anchor head. Anchoring is also effective in the case of thin tissue walls, which are penetrated by the anchor head 9 during the fastening process. The barb 20 or one of the expansion devices 21 or 22 successfully prevent withdrawal of the anchor head 9 from the tissue wall here too.
[0040] Exemplary embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A fastening device is for anchoring a surgical or diagnostic medical aid in the tissue of a human or animal hollow organ. The fastening device includes an anchor head, which is configured to penetrate the tissue; a driving device for driving the anchor head into the tissue; and a trigger device to trigger the driving of the anchor head into the tissue. | 0 |
BACKGROUND OF THE INVENTION
This invention relates in general to combined cycle power plants and, in particular, to an improved performance dual fuel combined cycle power plant capable of utilizing both distillate (liquid fuel) and natural gas fuels.
A combined cycle power plant utilizes a gas turbine and a steam turbine in combination to produce power, typically electric power. The power plant is arranged so that the gas turbine is thermally connected to the steam turbine through a heat recovery steam generator (HRSG). The HRSG is a noncontact heat exchanger which allows feedwater for the steam generation process to be heated by otherwise wasted gas turbine exhaust gases. The HRSG is a large duct with tube bundles interposed therein whereby water is heated to steam as exhaust gases are passed through the duct. The primary efficiency of the combined cycle arrangement is, of course, due to the utilization of otherwise wasted gas turbine exhaust gases.
A key parameter in optimizing the combined cycle efficiency is that the highest efficiency is achieved at the lowest stack gas temperature measured at the outlet end of the HRSG. In a dual fuel combined cycle plant a limiting factor to achieving optimum efficiency is that a minimum tube surface temperature must be maintained in order to prevent the occurrence of sulfur cold end corrosion on the tube bundles. The inlet feedwater temperature affects the surface temperature of the turbine bundles, which must be maintained at a minimum temperature to prevent condensation of certain sulfur compounds produced by combustion of the liquid distillate fuels. The dew point of the corrosive sulfur compounds increases with increased concentration of sulfur in the fuel. No such limitation exists for gaseous fuels having negligible sulfur content.
The conventional method for optimizing a combined cycle plant efficiency is to design the HRSG and steam system to operate with an HRSG inlet feedwater temperature and a stack gas temperature that would prevent low temperature heat transfer surface corrosion commensurate with the highest level of sulfur content in the fuel expected to be burned in the specific application. If an alternate fuel such as natural gas is burned with lower fuel sulfur content, the HRSG stack gas temperature cannot be lowered to improve efficiency even though the sulfur compound concentration would allow it, since the HRSG inlet feedwater temperature is fixed. Conversely, if the HRSG were designed with inlet feedwater and stack gas temperatures commensurate with the lowest fuel sulfur content to be expected, the plant efficiency would be improved; however, the HRSG heat transfer surface would experience corrosion if fuel with a higher sulfur content were burned. This phenomenon is more fully explained in U.S. Pat. No. 4,354,347 assigned to the assignee of the present invention, issued Oct. 19, 1982 to Tomlinson and Cuscino and which is fully incorporated herein by reference.
The HRSG includes a plurality of interconnected tube bundles which may be identified from top to bottom (for the case of a vertical gas path) as an economizer, an evaporator and a superheater. The HRSG heat exchange process is a counterflow process in that the temperature of the hot exhaust gases decreases as they rise through the HRSG whereas the temperature of the steam water mixture in the tubes increases as it descends downwardly against the upward flow of hot exhaust gases.
It should be pointed out that dual fuel capability is a highly desirable attribute in power plant design since it will enable the operator to take advantage of fuel availability and cost factors. If maximum operational efficiency were not available in both modes then the attractiveness of dual fuel capability would be considerably lessened.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a dual fuel combined cycle plant which overcomes the drawbacks of the prior art.
More specifically, it is an object of the present invention to provide a dual fuel combined cycle power plant capable of most efficient operation in both the liquid fired or gaseous fired modes.
It is another object of the invention to provide a feedwater recirculation loop between the steam turbine plant and the HRSG which selectively enables the operator to preheat feedwater during liquid fuel operation.
It is another object of the invention to allow the operator to bypass the feedwater heating process when the plant is being operated on natural gas.
It is a further object of this invention to enable the plant operator to fine tune feedwater temperature and economizer water flow rate in order to meet sulfur related requirements without the occurrence of "steaming" in the economizer section of the HRSG.
The novel features believed characteristic of the present invention are set forth in the appended claims. The invention itself, however, together with further objects and advantages thereof, may best be understood with reference to the detailed description of the invention and appended drawings.
SUMMARY OF THE INVENTION
The present invention is practiced in the environment of a dual fuel combined cycle power plant. The gas turbine is selectively operable on either liquid distillate fuel or natural gas. When operating on liquid distillate fuel a minimum temperature of the HRSG tube surface must be maintained in order to prevent sulfur cold end corrosion. A feedwater recirculation loop is used to preheat feedwater during liquid fuel operation and a bypass recirculation loop is utilized whenever the gas turbine is operating on natural gas. In addition, a conduit interconnects the evaporator with the economizer inlet and serves to increase both the economizer water flow rate and feedwater temperature during liquid fuel operation. This increased economizer water flow rate prevents "steaming" which would otherwise occur with the feedwater temperature elevated as required for corrosion-free liquid fuel operation. Feedwater heating in the feedwater recirculation loop is through extraction steam.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a schematic representation of a combined cycle power plant showing a feedwater recirculation loop in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A combined cycle power plant 11 includes a gas turbine power plant 13 and a steam turbine power plant 15 thermally interconnected through at least one heat recovery steam generator (HRSG) 17. The gas turbine power plant includes a gas turbine 19 drivingly connected to a compressor 21 and an electrical generator 23. A combustible mixture is formed and ignited in a combustor annulus only one of which combustors 25 being shown. The gas turbine combustor may be operated on natural gas or liquid distillate fuels. Hence, the combined cycle plant may be considered as possessing dual fuel capability.
The steam turbine power plant includes a steam turbine 29 which is drivingly connected to an electrical generator 31. In this configuration wherein there are two electrical generators driven by separate prime movers, the plant may be identified as a multi-shaft combined cycle power plant. Alternatively, both prime movers may be connected to a single generator in a configuration known as a single shaft combined cycle power plant.
Exhaust gas from the gas turbine power plant may be channeled through the HRSG 17 which may include a number of heating stages. The HRSG is a counterflow heat exchanger meaning that as feedwater progressively descends within the stack from economizer to superheater it is heated whereas as the exhaust gas ascends in the stack and gives up heat it will become cooler. The heating stages of the HRSG from low temperature end to high temperature end include a low pressure economizer 35 and a low pressure evaporator 37 associated with a low pressure steam drum 39; and, high pressure economizer 41 and high pressure evaporator 43 associated with steam drum 45. In addition, the output steam from steam drum 45 is delivered to superheater 47 whereupon it is passed through conduit 48 to steam turbine 29 through suitable control valves 49 only one of which is shown. In a two-pressure level HRSG as is shown, steam generated in the low pressure steam drum 39 is admitted into the steam turbine 29 at an intermediate stage through conduit 50 and control valves 51 only one of which is shown. Although the steam turbine is depicted as having one casing, it is well known that separate casings may be employed.
The present invention is preferably embodied in a feedwater recirculation loop 55 which interconnects the steam turbine deaerator condenser 57 with the inlet end of the HRSG at the low pressure economizer. The feedwater recirculation is comprised of a heater loop 59 and a bypass loop 61. The heater loop 59 may include one or more feedwater heaters 65 and an upstream isolation valve 67 and downstream isolation valve 69 for controlling feedwater flow through the heater loop. The feedwater heaters may for example be counterflow non-contact heat exchangers. Steam input into the feedwater heaters from low pressure turbine extraction points is controlled by means of extraction control valves 71. Valve 73 controls the flow of spent steam and hot water back to the deaerator condenser. Pump 75 pumps feedwater through the feedwater recirculation loop 55 to the HRSG. One advantage to the present invention is that the source of heating fluid to the feedwater recirculation loop is low pressure extraction steam. In previously known cycles such as that shown in U.S. Pat. No. 4,354,347 heretofore mentioned, a Deaerating Steam Supply Heater (DASSH) is heated by using higher pressure steam supplied from the HRSG or from an associated flash tank which is less efficient than drawing off extraction steam.
The bypass loop 61 includes upstream isolation valve 81 and downstream isolation valve 83 for controlling fluid flow through the bypass line during periods of plant operation on natural gas. The operation of the shut-off valves in both the heater loop and the bypass loop as well as the operation of the extraction control valves could be automated in a manner which would be obvious to one of ordinary skill in the art given the control objectives set forth herein.
An economizer recirculation loop 85 is integrated into the HRSG stack interconnecting the evaporator inlet with the economizer inlet. The purpose of the economizer recirculation loop is to provide additional feedwater flow to the economizer during periods of liquid fuel operation when the economizer inlet feedwater temperature is to be elevated so as to prevent the occurrence of "steaming" in the economizer. Valve 87 regulates the recirculation flow from the evaporator to the economizer. Pumps 91, 93 and 95 are self-explanatory from the schematic diagram and the direction of the flow arrows.
In operation, the present invention when applied to a dual fuel combined cycle power plant allows for highly efficient operation on natural gas while enabling the avoidance of cold end corrosion when operating on distillate fuels. Moreover, the utilization of extraction steam for heating feedwater rather than higher pressure admission steam or flashed steam present in a Deaerating Steam Supply Heater offers advantages in terms of thermal efficiency, equipment capital costs and performance reliability.
While the present invention has been disclosed in terms of its preferred embodiment as it is now known other modifications may occur to those having skill in the art. It is intended to cover in the appended claims all such modifications as fall within their true spirit and scope. | In a combined cycle power plant operable on either gas or liquid fuels maximum design efficiency is achieved at the lowest HRSG stack temperatures. This can be optimized for operation on natural gas but for liquid fuel operation consideration must be given to sulfur cold end corrosion. A feedwater recirculation loop is shown which allows for selectively heating feedwater during liquid fuel operation and for non-heating during gas operation. Economizer recirculation is also introduced to prevent economizer steaming. | 8 |
BACKGROUND
The present invention relates generally to spinning aperture radiometers and methods, and more particularly to spinning strip (partial) aperture imaging radiometers and methods that synthesize super-resolved scene estimates from a plurality of rotating strip aperture image measurements.
To provide high resolution images from space-based platforms, for example, conventional sensor architectures incorporate active control of large, heavy, deployable optical systems. Depending upon the mission requirements and the size of the primary mirror, the active control can range from periodic piston and tilt control of primary mirror segments to piston, tilt, figure, and alignment control of all optical elements comprising the sensor.
Full aperture systems with the same resolution as the present invention have a great deal of light gathering capability because of the relatively large aperture areas. However, to place multi-meter diameter apertures into orbit, full aperture systems competing with the present invention require: segmented optical surfaces and folded support structures, if the optical system diameters are larger than the launch vehicle's fairing; complex and potentially high bandwidth adaptive optical techniques, if thin deformable mirrors are used to save weight; and complex piston and pupil matching control, if implemented as a phased array. Therefore, the full aperture systems are relatively heavy and have relatively high technical risk and cost.
Prior art relating to and enhanced by the present invention is disclosed in U.S. Pat. No. 5,243,351 entitled "Full Aperture Image Synthesis Using Rotating Strip Aperture Image Measurements", assigned to the assignee of the present invention. The invention of U.S. Pat. No. 5,243,351 is known as the SpinAp system. The commonality between the approaches of the SpinAp system and the present invention (referred to herein as the SuperSpinAp system) arises from the use of temporally registered strip aperture measurements to synthesize an image, or estimate a scene.
Accordingly, it is an objective of the present invention to provide for spinning strip aperture imaging radiometers and methods that synthesize super-resolved scene estimates from a plurality of rotating strip aperture image measurements.
SUMMARY OF THE INVENTION
To meet the above and other objectives, one embodiment of the present invention provides for a spinning strip radiometer system and method that synthesizes super-resolved scene estimates from a plurality of rotating strip aperture image measurements. The expression super-resolved used herein refers to the ability of the present invention to accurately estimate scene information for spatial frequencies larger in magnitude than the aperture defined spatial frequency cutoff. Specifically, for the sensor system and data processing method described herein, super-resolution refers to extension of the information content of the estimated scene beyond the spatial frequency optical cutoff of the strip aperture system, and/or beyond the optical cutoff of the equivalent full circular aperture having radius equal to the largest correlation length associated with the strip aperture's geometry. The expression "strip aperture" refers to general aperture geometries described in U.S. Pat. No. 5,243,351.
The system includes a rotating strip aperture telescope that produces temporally contiguous or sequential images. The rotating strip aperture telescope typically comprises a rotating strip aperture primary reflector and a secondary reflector. A two dimensional detector array is provided to detect images located in the focal plane of the telescope. A rotation compensation device is employed to prevent rotational smear during the integration time of the detectors of the array. A signal processor is provided for recording a plurality of image frames of a target scene imaged by the telescope as the strip aperture rotates around the telescope's optical axis, and for synthesizing super-resolved estimates of the observed scene from the recorded images for spatial frequencies larger in magnitude than a spatial frequency cutoff of the rotating strip aperture, and/or beyond the optical cutoff of the equivalent full circular aperture of the SpinAp system.
The present invention thus provides for a spinning strip (partial) aperture imaging radiometer that synthesizes super-resolved radiometric scene estimates from a plurality of rotating strip aperture image measurements, while compensating for random, and/or systematic line of sight errors between individual strip aperture images. The present invention thus provides improved high resolution images when compared to the conventional SpinAp system for the same weight, or when compared to the conventional full aperture system of the same weight.
One embodiment of the synthesizing process performed by the sensor and processor of the present invention summarized above is as follows. As the spinning strip aperture rotates around the telescope's optical axis the following occurs. The rotation compensation device counter-rotates during the integration time of the detectors, thereby providing a temporally stationary image. An image frame is recorded and saved. If a rotating (relative to the scene) detector array architecture has been selected, the acquired frame is coordinate transformed and interpolated to a reference grid of the (not super-resolved) synthesized image. The data is Fourier transformed and stored. A new frame is recorded and saved. An estimate of the frame-to-frame misregistration of the recorded data due to random line of sight errors is obtained. The strip aperture images, or the Fourier transforms, are corrected for their line of sight errors and are stored. The preceding steps are sequentially repeated for each strip aperture image frame, or the frames are sequentially acquired and stored, and then global estimates of the line of sight are determined to register the frames.
Once the individual strip aperture frames have been registered, the super-resolution synthesis process begins. One embodiment of the super-resolution synthesis process incorporates the following steps. The desired amount of passband extension is used to determine the sample spacing for the synthesized super-resolved image. The coordinate system and spatial grid associated with the super-resolved image is referred to herein as a high resolution or super-resolution grid. Starting estimates of the super-resolved synthesized image and the mean value of the super-resolved image on the high resolution grid are determined. The starting estimate for the super-resolved image can be obtained by applying the SpinAp processing approach to the data, low pass spatial frequency filtering to obtain low noise samples, compensating for the full aperture transfer function, and expanding the estimate to the super-resolution grid by pixel replication. The starting estimate for the mean value of the super-resolved image can be obtained in a similar manner.
Once the starting points have been established, the nonlinear and iterative super-resolution technique forms subsequent estimates of the super-resolved scene by forming a product of the current estimate of the super-resolved scene with a nonlinear function of the current estimate. The nonlinear function is an exponential product of the plurality of rotational measurements scaled by the number of frames measured. The arguments of the exponentials are a function of the measurements, the strip aperture sensor's response function, and the current super-resolved scene estimate. The argument of the exponentials associated with each rotational position is obtained by performing a convolution of the response function of the reflected strip aperture for the particular rotational position with an auxiliary function. One element of the auxiliary function generation consists of dividing the pixel measurements by the convolution of the current estimate of the super-resolved scene with the spatial response function of the strip aperture for the particular rotational position.
Since each embodiment of the radiometer system and image synthesis processing method depends upon specific mission requirements and engineering tradeoffs, the radiometer system and image synthesis method incorporates means to compensate for random, and/or systematic line of sight drift between frames, and a priori and a posteriori known error sources, such as, non-isoplanatic optical system point spread functions, field point independent image smear due to image motion and finite electronic bandwidth of the detectors, and field point dependent image smear caused by uncompensated rotational motion of the image.
Incorporating a priori or a posteriori knowledge, such as the use of Markov Random Fields to implement postulates concerning scene structure, the use of total energy measurement criteria, or the use of alternate conditional probability density functions lead to straight forward modifications to the processing technique just described. The performance of the compensation techniques employed in the present system and method depend upon the accuracy of the a priori and a posteriori knowledge, and the effective signal to noise ratio.
The present system and method provide for an enhanced SpinAp class of space based optical imaging sensors and processing architectures that is capable of providing super-resolved imagery from an optical system comprising a rotating strip aperture. The image measurement and synthesis procedures of the present invention have advantages of providing a lower risk, lower cost, lighter weight, simpler fabrication and deployment alternative to deploying complex, large aperture adaptive optical systems for space based high resolution imaging applications.
The present system and method provide high resolution imagery from a satellite orbit, particularly when the weight of the telescope is a sizable fraction of the weight of the payload. The cost of launching a satellite is, in large, a function of its weight in orbit. Depending on operational system conditions, it is estimated that for a given allowable telescope weight, the present invention can provide up to 50% higher resolution than the conventional SpinAp system. The present invention may be used in such systems as high resolution (equivalent to large aperture) space based observatories.
The SuperSpinAp system makes use of the available measurements to generate a full aperture image, having a spatial frequency cutoff beyond the spatial frequency cutoff associated with the largest correlation length associated with the strip aperture, i.e. beyond the equivalent SpinAp (bandlimited) synthesized full aperture spatial frequency cutoff. The SuperSpinAp imagery is representative of images generated from a SpinAp strip aperture having a greater correlation length. Therefore, it would be an advantage to have a modified SpinAp image processing method that would result in lower payload weight for a given effective synthesized aperture size. Furthermore, it would also be advantageous to have a system and image processing method that provides a lower risk, lower cost, lighter weight, and simpler fabrication deployment alternatives to deploying complex, large full circular apertures (or phased array telescopes) requiring complex adaptive optical systems for space based imaging applications. In addition, since the super-resolution estimation techniques permit estimation of scene information outside the passband of the strip aperture, the SuperSpinAp processing procedure can provide the same synthesized image quality as SpinAp with fewer rotational samples.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIG. 1 illustrates a spinning aperture imaging radiometer system in accordance with the principles of the present invention;
FIG. 2 illustrates a first embodiment of a system and method in accordance with the principles of the present invention;
FIG. 3 illustrates a second embodiment of the present invention;
FIG. 4 illustrates a third embodiment of the present invention;
FIG. 5 illustrates a fourth embodiment of the present invention;
FIG. 6 illustrates a fifth embodiment of the present invention;
FIGS. 7a and 7b depict an embodiment of a super-resolution processing method associated with the inventions of FIGS. 2-6;
FIGS. 8a and 8b depict an embodiment of another super-resolution processing method associated with the inventions of FIGS. 2-6;
FIGS. 9a and 9b depict another embodiment of another super-resolution processing method associated with the inventions of FIGS. 2-6;
FIGS. 10a and 10b depict another embodiment of another super-resolution processing method associated with the inventions of FIGS. 2-6;
FIGS. 11a and 11b depict another embodiment of another super-resolution processing method associated with the inventions of FIGS. 2-6;
FIGS. 12-14 show test results using the present invention for various test patterns.
DETAILED DESCRIPTION
Referring to the drawing figures, FIG. 1 corresponds to FIG. 1 of U.S. Pat. No. 5,243,351, and provides an example of a spinning aperture imaging radiometer system 10 in accordance with and modified by the principles of the present invention. The contents of U.S. Pat. No. 5,243,351 are incorporated herein by reference. The spinning aperture imaging radiometer system 10 is adapted to synthesize super-resolved scene estimates, while removing line of sight jitter, and provide improved high resolution images when compared to conventional optical systems of the same weight, and when compared to a SpinAp system of the same weight. The spinning aperture imaging radiometer system 10 comprises a rotating strip aperture telescope 11 that includes primary 12a and secondary reflectors 12b. A tertiary reflector (not shown) may be employed in the telescope 11 under certain circumstances.
For the purposes of the present disclosure, the system 10 is shown in the form of a satellite comprising a stationary section 13 having an earth pointing antenna 13a. The telescope 11 is disposed on a platform 14, to which the stationary section 13 is also coupled. The spinning aperture imaging radiometer system 10 is adapted to record a number of image frames of a target scene imaged by the telescope 11 as the primary mirror 12a (comprising a strip aperture) rotates around the optical axis of the telescope 11. A line of sight stabilization mirror 15 and an image derotation device 16 are disposed along the optical path of the telescope 11 that are adapted to stabilize and derotate the image prior to its sensing by a detector array 17. The derotation device 16 counter rotates the image during the integration time of detectors comprising the detector array 17, under control of a rotation compensation controller 19, thereby providing a stationary image. The line of sight stabilization mirror 15 is used by a line of sight control system (such as may be provided by a signal processor or other dedicated control system) to remove high bandwidth line of sight errors, as well as line of sight errors due to orbital dynamics of the system 10. The target scene is imaged onto the detector array 17 located at the focal plane of the telescope 11 that is coupled to the signal processor 20 that is adapted to process the image frames. Alternatively, the signal processor 20 may comprise dedicated ground processor. The telescope 11, detector array 17 and related hardware are referred to herein as a sensor system 21. Individual image frames produced by the sensor system 21 are processed and combined in the signal processor 20 to synthesize super-resolved scene estimates in accordance with systems 10 and methods 30 of the present invention, and that are more specifically illustrated with reference to FIGS. 2-11.
Specific embodiments of SuperSpinAp systems 10 and methods 30 are described below. More specifically, FIGS. 2-11 illustrate various embodiments of the SuperSpinAp processing methods 30 in accordance with the principles of the present invention employed by the spinning aperture radiometer system and methods associated with FIG. 1 appropriately modified to implement the principles of the present invention. A particular embodiment is selected based upon the observational scenario and timelines, the amount of available prior knowledge, and the available computational throughput of the processing chain.
FIG. 2 illustrates a first embodiment of a system 10 and method 30 in accordance with the present invention, comprising a top level SuperSpinAp image synthesis method 30 implemented in the signal processor 20. The SpinAp sensor 21 acquires and generates a set of strip aperture images 22 that are transferred to the SuperSpinAp processor 23. The SuperSpinAp processor 23 synthesizes a super-resolved scene estimate 24.
Referring to FIG. 3, a second system 10 and method 30 is illustrated. The SpinAp sensor 21 acquires and generates a set of strip aperture images 22, which are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. By way of example, frame registration may be accomplished as follows. As the spinning strip aperture rotates around the optical axis of the telescope 11, the following occurs. The derotation device 16 counter-rotates during integration time of the detector array 17 to provide a temporally stationary image. An image frame is recorded and saved. If a rotating (relative to the scene) detector array architecture has been selected, the acquired frame is coordinate transformed and interpolated to a reference grid of the (not super-resolved) synthesized image. The data is Fourier transformed and stored. A new frame is recorded and saved. An estimate of the frame-to-frame misregistration of the recorded data due to random line of sight errors is obtained. The strip aperture images, or the Fourier transforms, are corrected for their line of sight errors and are stored. The preceding steps are sequentially repeated for each strip aperture image frame, or the frames are sequentially acquired and stored, and then global estimates of the line of sight are determined to register the frames. The registration processor 25 transfers the set of corrected frames, the set of uncorrected frames and registration error estimates between the frames, or both to the super-resolution processor 23. Using the corrected frames, or the uncorrected frames and the corresponding set of registration errors, the super-resolution estimation processor 23 generates the super-resolved scene estimate 24.
Referring to FIG. 4, a third system 10 and method 30 is illustrated. The SpinAp sensor 21 acquires and generates a set of strip aperture images 22, which are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The registration processor 25 transfers the set of corrected frames, the set of uncorrected frames and registration error estimates between the frames, or both, to a SpinAp bandlimited image synthesis processor 26 and the super-resolution estimation processor 23. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means of the SpinAp process described in U.S. Pat. No. 5,243,351. Using the corrected frames, the set of uncorrected frames and registration error estimates between the frames, or both, as well as the SpinAp bandlimited image, the super-resolution estimation processor generates an estimate of the super-resolved scene 24.
Referring to FIG. 5, a fourth system 10 and method 30 is illustrated. The SpinAp sensor 21 acquires and generates a set of strip aperture images 22, which are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The registration processor transfers the set of corrected frames, the set of uncorrected frames and registration error estimates between the frames, or both to the super-resolution processor 23. In addition, the correctly registered frames, or the set of uncorrected frames and the registration error estimates between the frames are transferred to the SpinAp bandlimited image synthesis processor 26. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means described in U.S. Pat. No. 5,243,351, while incorporating a priori knowledge of the scene or object structure stored in an image synthesis data base 27. Using the corrected frames, or the uncorrected frames and the corresponding set of registration errors, as well as the SpinAp bandlimited image, the super-resolution estimation processor generates the super-resolved scene estimate 24, while incorporating a priori knowledge of the scene or object structure stored in data base 27.
Referring to FIG. 6, a fifth system 10 and method 30 is illustrated. The SpinAp sensor 21 acquires and generates a set of strip aperture images 22, which are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The registration processor transfers the set of corrected frames, the set of uncorrected frames and registration error estimates between the frames, or both to the super-resolution processor 23. In addition, the correctly registered frames, or the set of uncorrected frames and the registration error estimates between the frames are transferred to the SpinAp bandlimited image synthesis processor 26. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means described by U.S. Pat. No. 5,243,351, while incorporating a priori knowledge of the scene or object structure stored in data base 27. The bandlimited SpinAp image is transferred to a training algorithm processor 28. Based upon information obtained from the SpinAp bandlimited image, the training processor extracts scene content and structure information, which is used to modify the a priori information contained in the data base 27. Using the corrected frames, or the uncorrected frames and the corresponding set of registration errors, as well as the SpinAp bandlimited image, the super-resolution estimation processor 23 generates the super-resolved scene estimate 24, while incorporating the a priori knowledge of the scene or object structure stored in data base 27, and modified by the training algorithm processor 28.
Realizations of SuperSpinAp processing are described below. FIGS. 7a and 7b depict an embodiment of the SpinAp super-resolution processing method used in the systems 10 and methods 30 of FIGS. 2-6. In the method depicted in FIGS. 7a and 7b, the SpinAp sensor 21 acquires and generates a set of strip aperture images 22, which are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The registration processor transfers the set of corrected frames 29 and registration error estimates between the frames to the super-resolution processor 23.
In addition, the correctly registered frames and the error estimates between the frames are transferred to the SpinAp bandlimited image synthesis processor 26. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means described by the U.S. Pat. No. 5,243,351. The bandlimited SpinAp image is modified to provide a first estimate 33 of the super-resolved scene.
The current super-resolved scene estimate 33 and the a priori information of the system response function 37 are used to determine the measurements for each frame that would result from observation of a current scene estimate 34. The determination of the anticipated measurements 34 is accomplished by convolving the current super-resolved scene estimate 33 with the system response function of the individual frames 37. The next steps 39 and 40 in the processing chain correspond to dividing the measurements 22, and the anticipated measurements 34 and subtracting unity, which is then convolved 40 with each frame's reflected response function 38. The resulting convolution 40 is summed for each frame 41 and then multiplied 42 by a scaling factor 43. The last steps in the first super-resolved estimates are to exponentiate 44 the output of steps 39 through 43 and multiply 45 the exponentiated result by the current super-resolved scene estimate 34. The result of steps 21 through 45 is the first true estimate 46 of the SpinAp super-resolved scene. The first true estimate 46 of the SpinAp super-resolved scene is then used as the current scene estimate 33, and the process continues for the desired number of iterations.
FIGS. 8a and 8b depict another embodiment of the SpinAp super-resolution processing method used in the systems 10 and methods 30 of FIGS. 2-6. In the method, depicted in FIGS. 8a and 8b the SpinAp sensor 21 acquires and generates a set of strip aperture images 22, which are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The registration processor transfers the set of corrected frames 29 and registration error estimates between the frames to the super-resolution processor 23.
Also, the correctly registered frames and the error estimates between the frames are transferred to the SpinAp bandlimited image synthesis processor 26. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means described by U.S. Pat. No. 5,243,351. The bandlimited SpinAp image is modified to provide the first estimate 33 of the super-resolved scene sample mean.
The current super-resolved scene sample mean estimate 33 and the a priori information of the system response function 37 are used to determine the measurements for each frame that would result from observation of the current scene sample mean estimate 34. The determination of the anticipated measurements 34 is accomplished by convolving the current super-resolved scene sample mean estimate 33 with the system response function of the individual frames 37. The next steps 39 and 40 in the processing chain correspond to dividing the measurements 22, and the anticipated measurements 34 and subtracting unity, which is then convolved 40 with each frame's reflected response function 38. The resulting convolution 40 is summed for each frame 41 and then multiplied 42 by a scaling factor 43. The last steps in the first super-resolved estimates are to exponentiate 44 the output of steps 39 through 43 and multiply 45 the exponentiated result by the current super-resolved scene sample mean estimate 33. The result of steps 21 through 46 is the first true estimate 46 of the SpinAp super-resolved scene. The first true estimate 46 of the SpinAp super-resolved scene is then used to update the current scene sample mean estimate 33, and the process continues for the desired number of iterations.
FIGS. 9a and 9b depicts another embodiment of the SpinAp super-resolution processing method used in the systems 10 and methods 30 of FIGS. 2-6. In the method depicted in FIGS. 9a and 9b, the SpinAp sensor 21 acquires and generates a set of strip aperture images 22 that are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The registration processor 25 transfers the set of corrected frames 29 and registration error estimates between the frames to the super-resolution processor 23. From the registered frames 29, the SuperSpinAp processor determines 29a the summed total of all detector and frame measurements, and the summed total of all detector measurements over all frame measurements less one. The sums are components of normalized correction terms 39a.
Also, the correctly registered frames and the error estimates between the frames are transferred to the SpinAp bandlimited image synthesis processor 26. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means described by U.S. Pat. No. 5,243,351. The bandlimited SpinAp image is modified to provide the first estimate 33 of the super-resolved scene.
The current super-resolved scene estimate 33 and the a priori information of the system response function 37 are used to determine the measurements for each frame that would result from observation of the current scene estimate 34. The determination of the anticipated measurements 34 is accomplished by convolving the current super-resolved scene estimate 33 with the system response function of the individual frames 37. The anticipated measurements 34 are also used to determine the summed total 35 of all frames and pixels that would result from the observation of the current scene estimate 33. The anticipated measurements 34 are summed over all pixels over all frames less one and all pixels 36 to produce a component of the normalized correction terms 39a.
The next step 40 in the processing chain corresponds to dividing the measurements 22 and the anticipated measurements 34, which is then convolved with each frame's reflected response function 38. The resulting convolution 40 is summed for each frame 41, then normalization correction terms comprising results from steps 29a, 35 and 36 are subtracted from this sum. This result is multiplied 42 by a scaling factor 43. The last steps in the first super-resolved estimates are to exponentiate 44 the output of steps 39 through 43 and multiply 45 the exponentiated result by the current super-resolved scene estimate 33. The result of steps 21 through 45 is the first true estimate 46 of the SpinAp super-resolved scene. The first estimate of the SpinAp super-resolved scene 46 is then used as the current scene estimate 33, and the process continues for the desired number of iterations.
FIGS. 10a and 10b shows another embodiment of the SpinAp super-resolution processing method used in the systems 10 and methods 30 of FIGS. 2-6. In the method of FIGS. 10a and 10b, the SpinAp sensor 21 acquires and generates a set of strip aperture images 22 that are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The frame registration error processor 25 transfers the set of corrected frames 29 and registration error estimates between the frames to the super-resolution processor 23.
In addition, the correctly registered frames and the error estimates between the frames are transferred to the SpinAp bandlimited image synthesis processor 26. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means described by U.S. Pat. No. 5,243,351. The bandlimited SpinAp image is modified to provide the first estimate 33 of the super-resolved scene ensemble mean.
The current super-resolved scene ensemble mean estimate 33 and the a priori information of the system response function 37 are used to determine the measurements for each frame that would result from observation of the current scene ensemble mean estimate 34. The determination of the anticipated measurements 34 is accomplished by convolving the current super-resolved scene ensemble mean estimate 33 with the system response function of the individual frames 37. The next steps 39 and 40 in the processing chain correspond to dividing the measurements 22 and the anticipated measurements 34, which is then convolved 40 with the reflected response function 38 of each frame. The resulting convolution 40 is summed for each frame 41 and then multiplied 42 by a scaling factor 43. The last step in the first super-resolved estimate is to multiply 45 the output of steps 39 through 43 by the current super-resolved scene ensemble mean estimate 34. The result of steps 21 through 45 is the first true estimate 46 of the SpinAp super-resolved scene ensemble mean. The first estimate of the SpinAp super-resolved scene 46 is then used as the current scene ensemble mean estimate 33, and the process continues for the desired number of iterations.
FIGS. 11a and 11b depict another embodiment of the SpinAp super-resolution processing method used in the systems 10 and methods 30 of FIGS. 2-6. In the method shown in FIGS. 11a and 11b, the SpinAp sensor 21 acquires and generates a set of strip aperture images 22, which are transferred to the frame registration error processor 25. The frame registration error processor 25 determines the residual registration errors between the individual frames of the set. The registration processor transfers the set of corrected frames 29 and registration error estimates between the frames to the super-resolution processor 23.
In addition, the correctly registered frames and the error estimates between the frames are transferred to the SpinAp bandlimited image synthesis processor 26. The SpinAp bandlimited image synthesis processor 26 generates images representative of full circular aperture images by means described by U.S. Pat. No. 5,243,351. The bandlimited SpinAp image is modified to provide the first estimate 33 of the super-resolved scene ensemble mean.
The current super-resolved scene ensemble mean estimate 33 and the a priori information of the system response function 37 associated with the first SpinAp frame measurement are used to determine the measurement for the first frame that would result from observation of the current scene ensemble mean estimate 34. The determination of the anticipated measurement 34 is accomplished by convolving the current super-resolved scene ensemble mean estimate 33 with the system response function of the first frame 37. The next steps 39 and 40 in the processing chain correspond to dividing the first SpinAp measurement 22 and the anticipated first measurement 34, which is then convolved 40 with the first frame's reflected response function 38. Unity is subtracted 39b from the resulting convolution and the result is multiplied 41a by the current estimate 34 of the scene ensemble mean. This result is multiplied 42 by a scaling factor 43. The last step in the first super-resolved estimate is to add 44a the output of steps 39 through 43 to the current super-resolved scene ensemble mean estimate 34. The result of steps 21 through 45 is the first true estimate 46 of the SpinAp super-resolved scene ensemble mean. The first estimate 46 of the SpinAp super-resolved scene is then used as the current scene ensemble mean estimate 33, and the process continues for the desired number of iterations.
Super-resolved SpinAp formulations are described below. For temporally stationary scene realizations, denoted by S m , the noise free detector output from the focal plane array of the strip aperture sensor, G m , can be represented as
G.sub.m =H.sub.m xS.sub.m, (1)
where x denotes the convolution operation. The subscript m denotes the m th rotational orientation of the strip aperture, during which the m th image frame is acquired, and H m is the total system response function. Sm represents a realization of the scene associated with the m th measurement. This is the most general model of noise-free SpinAp image acquisition.
The discrete form of the convolution of the scene with the system response function can be represented as, ##EQU1## where j indicates the detector output from location rj, and the k indicates the discrete scene element geometrically projected to the focal plane spatial position rk.
The system response function, H m , is the convolution of the optical system point spread function for the m th image acquisition, PSF m , with the individual detector response function, W m , for the m th frame, and is expressed as
H.sub.m =PFS.sub.m xW.sub.m. (3)
G m can be represented by a column matrix, denoted by G m , with elements corresponding to each of the detector measurements in the focal plane array. H m can be represented by a two dimensional matrix, denoted by H m , with elements corresponding to the system response function of the electro-optical sensor. Likewise, the scene may be represented as a column matrix, denoted by S m , with elements S k corresponding to samples of the m th scene realization projected to the super-resolution grid.
One embodiment of the SuperSpinAp processing procedure uses a Bayes estimation approach commonly referred to as maximum a posteriori probability estimation. Maximum a posteriori estimation seeks a value of the unknown object that maximizes the conditional probability of the object given the measurement. A maximum a posteriori approach to SuperSpinAp seeks an estimate of the super-resolved scene that maximizes the probability of the super-resolved scene given the entire set of SpinAp sensor measurements. In this embodiment of SuperSpinAp, the imaging model given in equation 2 is specialized to ##EQU2## in which the scene, S, is assumed to be a single scene realization during the SpinAp measurement interval.
Applying Bayes rule to the total set of SpinAp measurements yields an expression for the conditional probability of S given the measurements ##EQU3## G is the total measurement matrix, which is a block column matrix consisting of individual frame measurement matrices, given by ##EQU4## where n f is the total number of frames acquired. S is the matrix of scene samples projected to the super-resolution grid.
Assuming the scene emission, or reflection of photons for each pixel element is statistically independent, the probability density for the one dimensional scene matrix can be expressed as the product of probability density functions associated with each element, i.e., ##EQU5##
For scene statistics dominated by the source photon fluctuations, the probability density function of the scene pixel element is postulated to be the Poisson distribution ##EQU6## where k is an index designating the projected pixel element of the scene.
For statistically independent frame measurements the joint probability density of the total measurement vector given the scene can be expressed as the product of individual mth frame joint probability densities, ##EQU7##
Likewise, for statistically independent detector measurements the conditional probability of the occurrence of the frame measurement given the scene can be expressed as a product of the individual pixel probability densities conditioned on the scene, ##EQU8##
The total measurement conditional probability density is therefore given by the product of pixel and frame measurement probabilities conditioned on the scene, ##EQU9##
Assuming the individual detector measurements are a Poisson process, the individual measurement conditional probabilities can be expressed as, ##EQU10## is the mean value of the individual detector measurement.
Since finding the scene that maximizes the conditional probability density is equivalent to finding the scene that maximizes the logarithm of the probability density, solutions for S are sought that maximize ##EQU11##
Recognizing the logarithm of products is the sum of logarithms, the probability of the measurement matrix G given S can be expressed as ##EQU12##
Applying Stirling's approximation
ln[x!]≈xln[x]-x, (14)
to S(k)! yields ##EQU13##
To determine the value of S(l) that maximizes the conditional probability, the value of S(l) for which the derivative of ln[p(S|G)] vanishes is required. The derivative of ln[p(S|G)] is given by ##EQU14##
An iterative procedure, known as Picard's method, may be used to solve for the most probable unknown scene solution of the nonlinear equations. The iterative procedure is described by the equation ##EQU15## where superscripts [n] and [n+1] refer to current and next scene estimates, respectively.
Since super-resolved SpinAp estimates grid points corresponding to higher spatial frequencies than the original measurement, the iterative process includes remappings between the super-resolution coordinate grid and the measurement (or an intermediate reference) grid. One embodiment of the iterative algorithm accommodates for the differences in sample spacing between the measurement coordinate grids and the super-resolved coordinate grids by performing downsampling of the super-resolution grid by block averaging, and upsampling of the measurement grid by replication. Alternately, the upsampling and downsampling can be implemented using a higher-order interpolation technique. Indicating upsampling by .arrow-down dbl. and downsampling by .Arrow-up bold. the iterative solution is given by ##EQU16## and the mean value of the current estimate, S(l).sup.[n] has been replaced by the current estimate, S(l).sup.[n]. A scale factor may be included in the exponential to control convergence.
The previously described SuperSpinAp embodiment uses a maximum a posteriori estimation approach to estimate the scene S. An alternative embodiment uses sample statistics to represent the scene. Since S m and G m in equations (1) and (2) are random fields (two-dimensional arrays of random variables), it is possible to analyze the mean values of these random fields. Using <>to denote the sample mean over an ensemble of measurements, the mean value of the convolution can be represented as
<G.sub.m >=H.sub.m x<S.sub.m >, (16)
where the sample mean of the ensemble of scene realizations is expressed as ##EQU17## where n f is the number of measured SpinAp frames. As in the previous embodiment, maximum a posteriori equations are formulated and Picard's technique is applied to derive an iterative estimation procedure.
In this embodiment, G is defined as in equation 6, and S is analogously defined for the scene realizations.
Assuming the scene emission, or reflection of photons for each pixel element is statistically independent, and that the realizations S m are statistically independent over the measurement frames, the probability density for the one dimensional scene matrix can be expressed as the product of probability density functions associated with each element, i.e., ##EQU18##
For scene statistics dominated by the source photon fluctuations, the probability density function of the scene pixel element is postulated to be the Poisson distribution ##EQU19## where k is an index designating the scene's projected pixel element. The ensemble mean S(k) is approximated by the sample mean equation 3a, yielding ##EQU20## where a dummy index p is used to distinguish counting over frames from a specific frame m.
For statistically independent frame measurements the joint probability density of the total measurement vector given the scene can be expressed as the product of individual mth frame joint probability densities, ##EQU21##
Likewise, for statistically independent detector measurements the conditional probability of the occurrence of the frame measurement given the scene can be expressed as a product of the individual pixel probability densities conditioned on the scene, ##EQU22##
The total measurement conditional probability density is therefore given by the product of pixel and frame measurement probabilities conditioned on the scene, ##EQU23##
Assuming the individual detector measurements are a Poisson process, the individual measurement conditional probabilities can be expressed as, ##EQU24## where G(j) is the ensemble mean value of the individual detector measurement. The ensemble mean is estimated by the sample mean <G m (j)> in equation 3, yielding the measurement probability density ##EQU25##
Since finding the scene that maximizes the conditional probability density is equivalent to finding the scene that maximizes the logarithm of the probability density, solutions for S are sought that maximize ##EQU26##
Recognizing the logarithm of products is the sum of logarithms, the probability of the measurement matrix G given S can be expressed as
ln[p(G|S)]=Σ.sub.j Σ.sub.m ln[p(G.sub.m (j)|S)]. (25)
Substituting equation (25) into equation (24) yields ##EQU27##
Applying Stirling's approximation,
ln[x!]≈xln[x]-x, (26)
to S m (k)! yields ##EQU28##
A recursive procedure is derived, in which the q th realization, S q , is estimated and this estimate is used to update the estimate of <S>. To determine the value of S q (l) that maximizes the conditional probability, the value of S q (l) for which the derivative of ln[p(S|G)] vanishes is required. The ##EQU29## which after exponentiating and factoring H m becomes derivative of ln[p(S|G)] is given by ##EQU30##
An iterative procedure, known as Picard's method, can be used to solve for the most probable unknown scene solution of the nonlinear equations. The iterative procedure is described by the equation ##EQU31## where the superscript [n] and [n+1] refer to the current and next scene estimates, respectively. As in the previous embodiment, upsampling (denoted by .Arrow-up bold.) and down-sampling (denoted by .arrow-down dbl.) can be used to accommodate the differences in sample spacing between the measurement coordinate grids and the super-resolved coordinate grids.
A maximum a posteriori approach using a single probability density accommodating the total measurements is described below. The algorithmic procedure just described essentially has two unknowns that must be determined, the super-resolved scene pixel and the super-resolved scene pixel's mean value. Implementing the algorithm associated with the first set of super-resolved scene estimation equations incorporated an ad hoc procedure to estimate the scene pixel's mean value. Implementing the algorithm associated with the second set of super-resolved scene estimation equations uses sample statistics to approximate the ensemble mean for each scene pixel.
An alternative approach recognizes the total number of independent random variables to be a constant, i.e., the summed total of all measurements or the summed total of a fraction of the measurements is a random variable conditioned upon the individual measurements.
Therefore, a Bayes criteria is sought that maximizes the conditional probability of the super-resolved scene given the summed total of the measurements and the set of measurements less one. The nomenclature for the alternate procedure is identical to the first embodiment described herein.
For scene and measurement statistics dominated by the photon fluctuations, the probability density functions for the individual scene and measurement elements are postulated to be Poisson, i.e. ##EQU32## where S(k.Arrow-up bold.) is the scene's k.sub..Arrow-up bold. th projected "pixel's" mean value, and G m (k.sub..arrow-down dbl.) is the j th detectors measurement from frame m.
For n statistically independent Poisson random variables, X 1 . . . X n , having mean values X 1 and individual Poisson distributions ##EQU33## the summation of the Poisson random variables, ##EQU34## is also a Poisson random variable having a distribution given by F. A. Haight, in Handbook of the Poisson Distribution, page 71, ##EQU35##
For n statistically independent Poisson random variables, X 1 . . . X n , having mean values X 1 . . . X n , individual Poisson distributions, p(X k ), the conditional probability distribution of X 1 , . . . X n-2 , X n-1 given the summed total of random variables, ##EQU36## is multinomial and is given by F. A. Haight, in "Handbook of the Poisson Distribution", page 71, ##EQU37##
Application of equation (28) to the set of SuperSpinAp measurements depends upon selecting the measurement not explicitly present in the conditional probability. Since the numbering of the measurements is arbitrary, the conditional probability of the measurements given the summed total of measurements is expressed as
p(G.sub.1 (1), . . . ,GM(1); G.sub.1 (2), . . . ,G.sub.M (2); . . . G.sub.1 (N), . . . ,G.sub.M (N)|G.sub.tot)
where M=number of frames, if N is the number of detections per frame minus 1, or M=the number of frames minus 1, if N is the number of detections per frame, and ##EQU38##
Regarding any subset of data, ##EQU39##
Recognizing the total number of independent random variables are constant, i.e. the summed total of all measurements or the summed total of a fraction of the measurements is a random variable conditioned upon the individual measurements, provides a means to establish another modified self consistent maximum a posteriori approach to finding an estimate of the super-resolved scene. The Bayes estimation rule for the super-resolved scene given the total measurement and a set of measurements less one is ##EQU40## where G -- is a block matrix corresponding to the total set less one of the measurements and S is the matrix of scene samples projected to the super-resolution grid. The elements of the matrix G -- correspond to the set
(G.sub.1 (1), . . . ,G.sub.M (1); G.sub.1 (2), . . . ,G.sub.M (2); . . . G,(N), . . . ,G.sub.M (N)),
where M=the number of frames if N=the number of detections per frame minus 1; or M=the number of frames minus 1 if N=the number of detections per frame.
The self consistency requirement is once again incorporated by assuming the mean values of the individual detector measurements, and the mean value of the sum total of SpinAp measurements correspond to the noise free set of measurements i.e. ##EQU41## The .Arrow-up bold. and .arrow-down dbl. indicate the super-resolved and measurement coordinate spatial grids.
Since the imaging sensor measurements correspond to the detection of photons propagated from the scene, the scene's estimated values must be positive. Therefore, an additional self consistency requirement is
S≧0, (31)
which is implicitly satisfied by the embodiments of the super-resolution algorithms.
Determining the maxima of the probability densities is equivalent to determining the maxima of ln[p(S|G -- , G tot )].
The individual measurements are assumed to be statistically independent Poisson random variables, and the mean value of the individual measurements as well as the summed value of all or part of the total measurements summed are assumed to be Poisson random variables. In addition, the mean values of the Poisson random variables are assumed to be the noise free measurement, i.e. the mean value of the summed total SpinAp measurements is ##EQU42## and the mean value of the individual detector measurements is ##EQU43##
Therefore, substituting the mean values into the multinomial distribution for the probability of the measurements given the summed total measurement yields the corresponding probability also conditioned on the occurrence of the scene, i.e. ##EQU44##
Since the logarithm of products is the sum of logarithms, the logarithm of the measurements conditioned on the scene is
ln[p(S|G.sub.--, G.sub.tot)]=ln[p(G.sub.--,G.sub.tot |S)]+ln[p(S)]-ln[p(G.sub.--,G.sub.tot)].
Applying the Stirling approximation to the statistics for the projected pixels in the super-resolved scene, recognizing the logarithm of products is the sum of logarithms, and substituting the appropriate probability distributions into the logarithm of Bayes theorem, yields ##EQU45##
Since the maximum a posteriori embodiment of SuperSpinAp depends upon finding the super-resolved scene that maximizes the conditional probabilities, scene estimates are sought which solve the nonlinear partial differential equations resulting from the differentiation of the logarithm of the conditional probability, i.e. ##EQU46##
As with the previous approaches, the solution for the super-resolved scene must satisfy a set of nonlinear coupled equations generated by requiring the derivative of the conditional probability with respect to the scene super-resolved pixel to vanish. The set of simultaneous equations for the embodiment described in this section are: ##EQU47##
The numerical solution of the set of simultaneous equations can proceed by exponentiation and applying, the iterative method of Picard.
A summed measurement super-resolution embodiment will now be described. In this super-resolved SpinAp embodiment, an additional set of super-resolution equations is established based on the total number of measured photons in the SpinAp frames. The super-resolved scene value is determined by requiring the estimated scene value to be an extrema of the conditional probability density for the scene value given the occurrence of the total measurements, as well as an extrema of the conditional probability density for the scene value given the measured SpinAp frames. The two sets of equations can then be used to eliminate the unknown mean pixel value, leaving a set of nonlinear equations for the super-resolved scene pixel value. The set of nonlinear equations may be solved using the method of Picard. Details of the procedures leading to the definition of this alternate super-resolution procedure are described below
An alternative approach embodying noiseless measurement will now be described. As with the first version of the SpinAp super-resolution algorithm derivation, the noise free image measurement is represented as a convolution of the sensors system response function, H m , with the observed scene, S, or
G.sub.m =H.sub.m xS,
where x refers to the convolution operation. The discrete form of the m th frame's noise free image measurement, and the total of all detector noise free measurements for all of the frames will be expressed as ##EQU48##
In the previous equations, j is a one dimensional index associated with the detector location vector r j , and k is a one dimensional index associated with the detector location vector r k .
For isoplanatic optical systems and spatially uniform response focal plane array detectors, the m th frame's system response function may be represented as the convolution of the optical system's point spread function PSF m with the individual detector response function W m or
SRF.sub.m =PSF.sub.m xW.sub.m .tbd.H.sub.m
The modified maximum a posteriori approach uses two different Bayes probability rules to find an estimate of the super-resolved scene. The two Bayes rules, ##EQU49## correspond to the probability the super-resolved scene occurs given the total set of SpinAp measurements, and the probability the super-resolved scene occurs given the sum of all the SpinAp measurements has occurred, respectively. As defined previously, G is the total measurement matrix, which is a block column matrix consisting of individual frame measurement matrices, and S a column matrix consisting of individual scene elements projected to the super resolution coordinate grid, or ##EQU50## where n f is the total number of measurements frames, and n pixel is the total number of super-resolved points in the estimate of the super-resolved scene.
The self consistent super-resolution approach incorporating the conditional probability for the total measurement given the scene seeks an estimate for the scene, S, that maximizes the conditional probability for the scene given the complete set of SpinAp measurements, and also maximizes the conditional probability for the scene given the sum of all SpinAp measurements, i.e. a solution for S is sought that simultaneously maximizes p(S|G) and p(S|G tot ). For general distributions, an extrema solution satisfying both conditions may not be possible, however, the procedures and statistical postulates described in the following sections permit a solution in terms of a nonlinear set of equations.
The self consistency requirement is incorporated by assuming the mean values of the individual detector measurements, and the mean value of the sum total of SpinAp measurements correspond to the noise free set of measurements, i.e. ##EQU51## The .Arrow-up bold. and .arrow-down dbl. indicate the super-resolved and "measurement" coordinate spatial grids.
Since the imaging sensor measurements correspond to the detection of photons propagated from the scene, the scene's estimated values must always be positive. Therefore, an additional self consistency requirement is
S≧0, (34)
which is implicitly satisfied by the above-described super-resolution algorithms.
Since the logarithm is a monatomic function, determining the maxima of the probability densities is equivalent to determining maxima of ln p(S|G) and ln p(S|G tot ). Applying the logarithm to Bayes theorem, maxima for ##EQU52##
For statistically independent frame measurements the joint probability density of the total measurement vector given the scene can be expressed as the product of individual m th frame joint probability densities, ##EQU53##
Likewise, for statistically independent detector measurements the conditional probability of the occurrence of the frame measurement given the scene can be expressed as a product of the individual pixel probability densities conditioned on the scene ##EQU54##
The total measurement conditional probability density is therefore given by the product of pixel and frame measurement probabilities conditioned on the scene, ##EQU55##
Assuming the scene emission, or reflection of photons for each pixel element is statistically independent, the probability density for the one dimensional scene matrix can be expressed as the product of probability density functions associated with each element, i.e., ##EQU56##
For scene statistics dominated by the source photon fluctuations, the probability density function of the scene pixel element is postulated to be ##EQU57## where S(k.sub..Arrow-up bold.) is the scene's k.arrow-down dbl. th projected "pixel's" mean value.
Assuming the individual detector measurements are also a Poisson random process implies the individual detector measurement probability density function is ##EQU58##
Substituting the m th frame measurement's j.arrow-down dbl. th "pixel's" mean value ##EQU59## yields an expression for the probability of the detector measurement given the scene ##EQU60##
Since the sum of statistically independent Poisson random variables is also a Poisson random variable the summed total of all the SpinAp detector probabilities is Poisson random variable and is given by ##EQU61## Substituting the mean value or the summed total SpinAp measurements, ##EQU62## into the Poisson probability density, yields the conditional probability of G tot given S has occurred ##EQU63##
Since the logarithm of products is the sum of logarithms, the logarithm of the measurements conditioned on the scene is ##EQU64##
Substituting the previous equations into the conditional probability for the set of scene measurements given the scene yields ##EQU65##
Determining the logarithm of p(S|G tot ) depends upon determining the logarithm of the conditional probability of the summed total measurement given the scene, ##EQU66##
Substituting into Bayes theorem for the relationship of the conditional probabilities, yields ##EQU67##
For photon counts greater than approximately 50 photons, the Stirling approximation
ln[x!]≈xln[x]-x,
may be used to simplify the calculation procedure. The Stirling approximation applied to the two conditional probabilities of interest yields, ##EQU68##
The extrema equations required to solve for the scene maximizing the probability are obtained by differentiating the logarithm of the appropriate probabilities with respect to the desired scene pixel element, S(l.sub..Arrow-up bold.). The differentiation operation yields ##EQU69## and ##EQU70##
Simplifying the equations by summing over the Kronecker delta function indices produces, ##EQU71## and ##EQU72##
The set of equations associated with setting the derivative of the logarithm of the scene probability given the measurements are ##EQU73##
Solving for the logarithm of S(l.sub..Arrow-up bold.) yields a set of coupled nonlinear equation for ##EQU74##
Exponentiating produces ##EQU75##
The set of equations associated with setting the derivative of the logarithm of the scene probability given the summed total measurements are ##EQU76##
The two sets of equations (35) and (36) can be solved simultaneously to formulate an estimation procedure for S(l.sub..Arrow-up bold.) or S(l.sub..Arrow-up bold.).
The SuperSpinAp embodiments in described above apply the maximum a posteriori estimation technique. An alternate approach to SuperSpinAp processing uses a Bayes estimation approach commonly refereed to as maximum likelihood estimation.
Maximum likelihood estimation seeks a value of the unknown object that maximizes the conditional probability of the measurements given the object. That is, the maximum likelihood estimate of the object is the object that most likely led to the entire set of observed SpinAp sensor measurements.
As before, G is the total measurement matrix, which is a block column matrix consisting of individual frame measurement matrices, given by ##EQU77## where n f is the total number of frames acquired. S is a block column matrix associated with n f realizations of the random scene ##EQU78##
Given that the scene S is a random field, a maximum likelihood estimate of the scene mean is calculated. The maximum likelihood estimate is the value of the scene mean, S, which maximizes the likelihood function P(G|S).
For statistically independent frame measurements the joint probability density of the total measurement vector given the scene can be expressed as the product of individual m th frame densities ##EQU79##
Likewise, for statistically independent detector measurements the conditional probability of the occurrence of the frame measurement given the scene can be expressed as a product of the individual pixel probability densities conditioned on the scene, ##EQU80##
The total measurement conditional probability density is therefore given by the product of pixel and frame measurement probabilities conditioned on the scene, ##EQU81##
Assuming individual detector measurements are a Poisson process, the individual measurement conditional probabilities can be expressed as, ##EQU82## where ##EQU83## is the mean value of the individual detector measurement.
Since finding the scene that maximizes the conditional probability density is equivalent to finding the scene that maximizes the logarithm of the probability density, solutions for S are sought that maximize
ln[p(G|S)]. (42)
Recognizing the logarithm of products is the sum of logarithms, the probability of the measurement matrix G given S can be expressed as ##EQU84##
Substituting Equation (43) into Equation (42) yields ##EQU85##
To determine the value of S(l) that maximizes the conditional probability, the value of S(l) for which the derivative of ln[p(G|S)] vanishes is required. The derivative of ln[p(G|S)] is given by ##EQU86##
Setting the derivative to zero yields the nonlinear equation to be solved for S ##EQU87##
In most implementations the left hand side will sum to n f , due to the photon conserving properties of optical systems. To apply Picard's technique, each side of Equation (44) is multiplied by S(l) and the estimate is formed iteratively as ##EQU88## where the superscript n indicates the iteration number.
This method of computing the SuperSpinAp maximum likelihood estimate is an expectation maximization algorithm. Expectation maximization algorithms converge to a maximum likelihood estimate of the scene mean.
For each iteration of the algorithmic procedure just described, a multiplicative correction factor is computed from the entire set of n f SpinAp measurements. A recursive expectation maximization algorithm may be used to compute the maximum likelihood estimate. A recursive algorithm updates the estimate based on each frame individually, thereby reducing the computational requirements for determining the maximum likelihood estimation.
The recursive form of the expectation maximization algorithm extends the method developed by Titterington in Journal of the Royal Statistical Society--B, Vol. 46, No. 2, pages 257-267, 1984) to apply to the SuperSpinAp. The following recursive expectation maximization algorithm is obtained for n=0,1, . . . , for m=0,1, . . . , N f -1, for l=1,2, . . . , N pixel ##EQU89##
This recursive expectation maximization algorithm may be initialized using the methods described previously, or be initializing each element of the scene mean estimate to a constant value based on the average number of photons in the SpinAp frames ##EQU90##
The SuperSpinAp embodiments described above comprise two broad solution approaches for estimating the unknown scene--maximum a posteriori estimation, and maximum likelihood estimation. Within the category of maximum a posteriori estimates, four embodiments are disclosed including a maximum a posteriori approach in which the scene mean S(l) is estimated in an ad hoc manner, by estimating the scene mean as equal to the current estimate of the scene, a maximum a posteriori approach in which the scene mean S(l) is estimated using sample statistics, resulting in a recursive algorithm for estimating each realization of the scene S q (l), followed by a re-estimation of the sample mean, a maximum a posteriori approach in which a single probability density function is formulated on the measurements and the total photons in the set of measured SpinAp frames, and a maximum a posteriori approach in which a separate probability density function is formulated on the total photons in the set of measured SpinAp frames, followed by simultaneous solution of two sets of nonlinear equations.
Within the category of maximum likelihood estimates, two embodiments have been described. The first embodiment uses the set of measured SpinAp frames to form an estimate of the scene ensemble mean S(l) in which the entire set of SpinAp frames is used in each update of the estimate. In the second maximum likelihood embodiment, a recursive algorithm is used, in which the scene ensemble mean estimate is updated using one SpinAp frame measurement at a time. Each of the maximum likelihood embodiments are expectation maximization procedures, thereby guaranteeing that the Picard iterations converge to a maximum likelihood estimate.
For completeness, FIG. 12 depicts results of a demonstration of the SuperSpinAp synthesis method 30 use to generate a super-resolved image of a radial test pattern. FIG. 13 depicts an example of SuperSpinAp synthesis performance. Quantitative measures of the performance are obtained by determining correlation coefficients between the known reference power spectrum of an object and the power spectrum of the super-resolved image. FIG. 14 depicts an example of SuperSpinAp synthesis performance where the true scene is a horizontal bar target. Quantitative measures of the performance are found by determining correlation coefficients between the known reference power spectrum of an object and the power spectrum of the super-resolved image.
Thus, a spinning strip (partial) aperture imaging radiometer and method that synthesizes super-resolved scene estimates from a plurality of rotating strip aperture image measurements have been disclosed. It is to be understood that the described embodiments are merely illustrative of some of the many specific embodiments which represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention. | A spinning strip aperture imaging radiometer sensor system and data processing method for synthesizing a super-resolved scene estimate (super-resolved scene) from a plurality of image frames acquired by the strip aperture imaging sensor system. One embodiment of the imaging system comprises a rotating strip aperture wide field of view telescope, a two dimensional detector array for detecting images in the focal plane of the telescope, rotation compensation apparatus for preventing rotational smear during the integration time of the detectors, a signal processor for recording a plurality of image frames of a scene that is imaged by the telescope as it rotates around its optical axis, and an estimation processor employing the present method for synthesizing the super-resolved scene estimate from the recorded images. The super-resolved image synthesis method uses a plurality of rotating strip aperture measurements within the strip aperture passband and within the passband of an equivalent bandlimited synthesized full circular aperture to estimate the spatial frequency information outside the total measurement passband, and/or outside the passband of the equivalent bandlimited synthesized full circular aperture, as well as within the equivalent bandlimited passband. Knowledge of the spatial response function of the strip aperture, the spatial response function of the detector array, noise statistics, and the temporal registrations of each of the recorded strip aperture images permits synthesis of the super-resolved full aperture image by the sensor system and image synthesis method. The super-resolved image synthesis method may be employed in the spatial domain, the spatial frequency domain, or both. | 6 |
BACKGROUND OF THE INVENTION
Maintaining the well being of the GI tract of a mammal is a very desirable goal. Particularly annoying are inflammatory conditions of the GI tract. Some of the signs of inflammation of the GI tract include acute or chronic diarrhea, soft stools, blood in stool, vomiting, poor nutrient digestion and absorption, weight loss and poor appetite. Diseases such as gastritis, enteritis, colitis, inflammatory bowel disease, ulcers, certain types of cancer and other conditions are known to have GI inflammation as a main component.
We have found that a mixture of certain materials can bring about the amelioration of the principle signs of GI inflammation such as diarrhea. The frequency of eliminations as well as the quality of the elimination can be substantially improved when GI tract inflammation is improved, particularly in a companion pet such as a cat, when appropriate levels of glutamine, fermentable fiber(s), antioxidant(s) and omega (n)-3 fatty acids are orally administered to the mammal.
SUMMARY OF THE INVENTION
In accordance with the invention, there is a composition suitable for mammalian oral ingestion in a mammal having GI tract inflammation comprising an anti-diarrhea effective amount of a combination of glutamine, fermentable fiber(s), antioxidant(s) and omega-3 fatty acid(s).
A further aspect of the invention is a method for managing diarrhea in a mammal having GI tract inflammation comprising orally administering to the mammal a composition described above.
DETAILED DESCRIPTION OF THE INVENTION
Glutamine is a well known as a material which is important for lymphocytes to proliferate and important as a nutrient for intestinal cells. Glutamine is also a precursor for glutathione, a natural antioxidant in the body. All wt % disclosed here for any constituent are on the basis of a daily diet for the mammal. All numbers are calculated on a dry matter basis.
The quantity of glutamine is a minimum of about 0.1, 0.15 or 0.2 wt %. The maximum generally does not exceed about 5, 4 or 3 wt %.
Fibers which can be employed are those which are moderately fermentable, highly fermentable or blends of the two. Low or non-fermentable fibers can also be added at low levels without impacting the formulation.
We have shown that certain prebiotic fiber ingredients when fermented by existing bacteria from the GI tract of dogs and cats produce high levels of butyrate and other short chain fatty acids which would acidify the GI tract and reduce the growth of pathogens. Prebiotic fibers that produce high levels of butyrate include but are not limited to mannan-oligosaccharide, pectin, xylooligosaccharide, burdock, beet pulp, inulin, galactose, other xylans, fructans, dextrans, beta glucan, resistant starches, polysaccharide from gums, etc., should be present at levels between about 0.5-20 wt % of diet with the preferred levels between about 1-5 wt %. Gums may include gums produced by microorganisms such as gellan gum, xanthan or gums produced by plants such as acacia. The blend is preferably formulated based on high butyrate production and moderate fermentability based on volatile fatty acids (VFA) production and organic matter disappearance to help maintain optimal GI health. The composition can include at least about 10-60% of a moderately fermentable fiber and about 20-40% of a highly fermentable fiber. These fibers should be chosen such that the butyrate production of these fibers is high, between about 5-40% of total VFA. Moderately fermentable fibers are defined as having an organic matter disappearance of from about 15 to 60 percent when fermented by fecal bacteria in vitro for a 24 hour period. That is, from about 15 to 60 percent of the total organic matter originally present is fermented and converted by the fecal bacteria. Highly fermentable fibers have greater than a 60% disappearance rate.
Antioxidants can also be employed in the compositions and methods. Vitamin E, C and blends thereof can be employed. Any precursors of these vitamins can be employed, such as tocopheryl acetate and sodium ascorbate. Vitamin E is a minimum of about 0.1, 0.2 or 0.4 wt % and generally does not exceed a maximum of about 3, 2 or 1 wt % of the diet. Vitamin C is a minimum of about 0.1, 0.2 or 0.4 wt % and generally does not exceed a maximum of about 3, 2, or 1% of the diet.
Omega-3 fatty acids are well known dietary constituents and are primarily found in fats and oils, particularly fish oils such as menhaden, salmon and the like. Principle constituents of the omega-3 fatty acid are ecosapentaenoic acid (EPA), docosahexanoic acid (DHA) and alpha-linolenic acid (ALA). The quantities of omega-3 fatty acids are generally a minimum of about 0.1, 0.2 or 0.5 wt % and generally do not exceed a maximum of about 3, 2 or 1 wt %. Also generally present in the fats and oils are omega-6 fatty acids. The proportion of omega-6 fatty acid when present to omega-3 fatty acid on a weight basis is from about 0.5:1 to 6:1, preferably about 2:1 to 4:1.
The following examples illustrate the benefits to be achieved using the composition of the invention in managing diarrhea in a mammal. The mammal has or can have GI tract inflammation, preferably inflammatory bowel disease.
EXAMPLE 1
In the following study, 12 cats with inflammatory bowel disease (IBD) were fed 2 varieties of food for a period of 2 weeks each. Six cats were fed Food A and 6 cats fed Food B for 2 weeks, followed by a crossover. Stool quality was monitored daily and the score based on a 1-5 scale, with 1 being runny and watery and 5 being hard and formed, see scores below. Stools from cats with IBD typically are 1 or 2.
Stool Monitoring Scoring
1: watery
2: soft, unformed
3: soft, formed, moist
4: hard, formed, dry
5: hard, dry pellets
Table 1 shows the effect of diets on the stool quality of cats with chronic diarrhea. The table show the percent of stools with scores of 1-5. The first canned Food A contained 3% of a fiber with low fermentability, less than 15%, and the canned Food B contained 1.5% of a fiber with high fermentability, above about 60% fermentability. The nutrient content of the foods are listed below.
Food A Food B Low High fermentable fermentable fiber food fiber food Moisture 72.69 72.58 Protein-Kjeldahl 8.24 7.94 Fiber, Crude 0.3 0.2 Crude fat by acid hydrolysis 9.58 9.85
Results
The results show that feeding Food B containing a highly fermentable fiber source improved the stool quality of the cats from having 42% stools scoring 1's and 2's to only 15% scoring 1's and 2's.
TABLE 1
% of Stools
Food A
Food B*
Stool quality
Low fermentable
High fermentable
Score
fiber food
fiber food
1
11
2
2
31
13
3
41
45
4
10
22
5
7
14
*4% of stools were not available for grading
EXAMPLE 2
Table 2 shows the data from a study where the same cats as in example 1 were fed 2 different foods. Both foods contained similar levels of prebiotic fibers and Omega-3 fatty acids. Food C contained added glutamine and antioxidants whereas Food D did not contain added glutamine or antioxidants. Half the cats were fed Food C for 2 weeks and the other half were fed Food D. This was followed by a washout of one week for all the cats. They were then crossed over to the other food for an additional 2 weeks. The results in Table 2 show that when the cats were fed Food C that included glutamine and high antioxidants, the stool quality was significantly improved (0% stool score of 1 and 2) compared to the stool quality when the cats were fed Food D, the diet without added glutamine and antioxidants (7% stool with score of 1 and 2). Food C has significantly better results in stool quality, 0% stool scores of 1 and 2, compared to Food A having 42% of its stool score 1 and 2. Food C is also significantly better than Food B having 15% of stool scores of 1 and 2. Food C is also significantly better than Food D which has 7% of stool scores 1 and 2. Food C has all the significant components of this invention: glutamine, antioxidant, fermentable fiber and n-3 fatty acids. Foods A, B and D were all missing at least one of these components.
The nutrient content of the food is listed below.
All options except
glutamine and
All options
antioxidant
Formula
(Food C)
(Food D)
Moisture %
75–76
75–76
Protein-Kjeldahl %
10
10.1
Crude Fiber %
0.2
0.4
Ash %
1.49
1.69
Crude Fat %
4–6
4–6
Insoluble fiber %
1–1.5
1–1.5
Soluble fiber %
0.1–0.3
0.1–0.3
Omega 3 (calc)
0.13
0.06
Omega 6 (calc)
1.51
0.46
ascorbic acid μg/g
30–50
4–10
total tocopherols
300–400
30–50
μg/ml
TABLE 2
Percentage of Stools
Stool quality
Food C
Food D [all options except
score
[all options]
glutamine & antioxidants]
1
0
0
2
0
7
3
29
67
4
58
27
5
13
1
The data shows that the diet with added glutamine and antioxidants continues to sustain the improvement in stool quality in these cats.
EXAMPLE 3
The next experiments show that the glutamine source that was used in the previous example is bioavailable and is able to stimulate the immune function. Glutamine is an important nutrient to the intestinal tract as it is the major fuel source for enterocytes and lymphocytes. A majority of the glutamine in the diet is absorbed by cells of the intestine as well as immune cells in the intestine.
In one experiment, a source of glutamine was tested to see if it was bioavailable and able to deliver adequate glutamine to the intestinal cells. The source of glutamine was a wheat hydrolysate with an enrichment of 30% glutamine. A dose response study was carried out in 6 dogs to see if increasing levels of the glutamine source (0, 0.5, 1.0, 2% glutamine content) was detected in the plasma after feeding the diet.
TABLE 3
Change in postprandial plasma glutamine in animals fed foods
supplemented with different levels of glutamine.
% supplemented
% Change in plasma
glutamine
glutamine from control
0.5%
3
1.0%
10
2.0%
15
The data shows that there was an increasing response to the increased levels of glutamine in the diet, particularly 30 min after the meal. This shows that the glutamine is available to the blood stream after extraction by the intestinal cells.
In a further experiment, the efficacy of glutamine as a immune-modulator was examined. 20 Beagle dogs were randomly allocated into 4 groups receiving either basic diet or basic diet supplemented with 1%, 2%, or 4% glutamine. Blood samples were drawn in heparinized tubes from animals 2 hrs after their last feeding on day 1 and 16. Samples were prepared for immune measurement. (T cell proliferation assay).
T-cell proliferation assay. Peripheral blood leukocytes (PBL) in each blood sample were counted using Nova Celltrak II (Beckman Coulter Corp., Fla.). Blood was diluted (1:20) with supplemented media. Diluted blood was plated, in triplicate, in 96 well cell culture plates with the following mitogens diluted in supplemented media: Concanavalin A (0.5 μg/ml, 2.5 μg/ml. Plates were incubated in a humidified incubator containing 7% CO 2 at 37° C. for 72 hrs. Cellular DNA was Ci/well [pulse labeled 18 hrs before harvesting with 1 3 H] thymidine. Cellular DNA was harvested on glass fiber paper using a cell harvester (Skatron Instruments Inc., Va.) and suspended with 1.5 ml scintillation cocktail. [ 3 H]thymidine uptake was quantified as counts per minutes (CPM) using TriCarb 2100TR Liquid Scintillation Analyzer (Packard BioScience Company, Ill.). Counts were normalized to CPM/10,000 cells to account for variation in PBL concentrations.
Effect of Glutamine on Lymphocyte Proliferation
Concanvalin A (Con A) is a polyclonal T-cell mitogen. In the presence of Con A mitogen, overall analysis showed a significant effect of diet, but no effect of Con A dose, or dietary treatment by Con A dose interaction. Thus, the data were collapsed across the different doses of Con A to show the proliferative response of lymphocytes dependent on percentage of glutamine supplemented in the diet.
TABLE 4
Proliferation of T cell lymphocyte in response to ConA mitogen
T cell proliferation
Food
(log 10 cpm)
No supplemented glutamine
4.7
1% supplemental glutamine
5
2% supplemental glutamine
4.8
4% supplemental glutamine
4.5
There was a significant main effect of dietary treatment (P<0.01). Dietary supplementation of 1% glutamine showed maximum lymphocyte proliferation which was significantly different from the control group (P<0.05). Dogs supplied with 1% and 2% glutamine showed similar increases in lymphocyte proliferation. There was a significant difference between these groups and the proliferative response of lymphocytes from animals supplemented with 4% glutamine in their diet (P<0.01). This indicates that supplementation with 1-2% glutamine enhances overall T-lymphocytes proliferation. However, 4% glutamine is not additionally beneficial in this respect. | A composition suitable for mammalian oral ingestion in a mammal having GI tract inflammation comprising an anti-diarrhea effective amount of glutamine, fermentable fiber(s), antioxidant(s), and omega-3 fatty acid(s). | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of window shade assemblies. More particularly, the invention relates to an improved window shade assembly having a hold down feature which can be raised or lowered by either a use of lift cords or through direct manual movement of the bottomrail.
2. Description of the Prior Art
Window shade assemblies are typically operated by having one or more lift cords being connected at one end to the window shades or to a bottomrail connected to the window shades and having the other ends which extend out of the shade being accessible to the operator. The lift cords typically travel through or along a headrail. The window shades are typically raised by the operator pulling on the accessible portion of the lift cords and are lowered by allowing the weight of the shades to pull the lift cords back into the shades. When the operator has moved the shade to a desired position, the lift cords are held in place so that the shade will remain in the chosen position after the operator has let go of the lift cords. Various types of cord locking devices are used for this purpose.
The prior art of the window shade industry teaches "hold down" type arrangements in which the bottomrail may be locked or snapped into position relative to the window frame. For example, U.S. Pat. No. 4,727,921 to Vecchairelli teaches a venetian type window shade assembly that may be raised and lowered through the use of lift cords. The bottomrail is provided with studs which may be snapped into apertures in the sidewalls of the window frame, such that the bottomrail is locked into place when the studs are thus snapped into the apertures. Vecchairelli provides the use of lift cords to raise and lower the shade. When it is desired to raise the shade, the bottomrail studs are removed from the apertures.
Similarly, U.S. Pat. No. 5,069,264 to Klawiter discloses another hold down type window shade arrangement in which a fixed bracket and a bottomrail are engageable to one another. When the bottomrail and hold down bracket are so engaged, the window covering position is locked and the bottomrail may not be raised.
It is also known in the window shade industry to provide cords which are used to guide the window shade (these cords are referred to as "guide cords"). These guide cords are typically connected to the headrail and extend downward, passing through the bottomrail, before connecting to the surrounding window frame. The guide cords are then placed under tension so that the bottomrail may be raised and lowered directly by manual movement of the bottomrail in which the position of the bottomrail is held by friction between the guide cords and the bottomrail.
It is also generally known in the prior art that some windows, such as the type mounted in various vans, campers and recreational vehicles have a plastic frame which encircles the window. The plastic frames then have holes or indentations provided on them. Guide cords are attached at their ends to plastic anchors which are then affixed to this plastic frame at the time of window installation. The guide cords are thus held in position by the plastic anchors. This type of window assembly provides no means for releasing the plastic anchors except through disassembly of the window assembly by prying out the anchor from the frame. Movement of the bottomrail does not disattach the anchors from the frame.
U.S. Pat. No. 4,865,108 to Hennequin et al. discloses a frame for window shade assembly that provides a number of passageways through the headrail and siderails for cords to pass therethrough. This, according to Hennequin et al., permits a degree of variability for the actuation of the shade. Thus, different actuation means could alternatively be installed during assembly, or the type of actuation means could be changed after assembly. Hennequin et al. do not, however, allow for different actuation means to be simultaneously employed in the window shade assembly.
Thus, there is a need in the prior art to provide a window shade assembly in which alternative actuation means are provided within a single assembled window shade assembly. In particular, it is desirable for a window shade assembly to have a lift cord actuation as well as a direct manual manipulation of the bottomrail.
Such alternative actuation means are desirable for, among other reasons, safety considerations. Lift cords provide an attractive nuisance to young children who may all too frequently be strangled or otherwise injured on the lift cords. A design having alternative actuation means would allow for lift cord operation when no children are present but would also allow for the lift cord to be tied back or otherwise removed from accessibility when children are present in which the shade assembly may still be operated by direct manual movement of the bottomrail.
SUMMARY OF THE INVENTION
The invention provides a window shade assembly that is capable of being raised and lowered through the use of lift cords but may also be raised and lowered by direct manual manipulation of the bottomrail. The window shade assembly has a hold down feature that prevents the window shade from moving out of its normal plane (which in the case of a vertical window pane is away from or toward the window) in response to air currents or to the frame moving as when the shade is mounted to a door or directly to a hinged window frame.
The window shade assembly has a headrail and a bottomrail that are spaced apart from one another. The headrail is generally fixed with respect to the surrounding window frame structure and the bottomrail is movable toward or away from the headrail. Window shade material is provided between the headrail and the bottomrail. The window shade material may be any suitable type, such as pleated fabric, tabbed pleated fabric, cellular fabric, roman shades, venetian blind slats and ladders, or any covering that can be raised and lowered by cords.
The window shade assembly also has one or more and preferably two or more cords traveling through the headrail and through the bottomrail. A first end of each cord is accessible to an operator. A second end of each cord is connected to a respective one of a pair of transfer plates. A pair of brackets is also provided, each having a channel running therethrough. The transfer plates and channels are sized and configured so that the transfer plates are engageable and disengageable with a respective bracket. When the transfer plates are engaged with the bracket, the transfer plates are prevented from moving directly toward the headrail and thus, their position is secured relative to the headrail until disengaged from the bracket. The transfer plates are engaged with the brackets preferably by having a portion of the transfer plates being inserted within the bracket channels. Preferably, the transfer plates have a generally circular extending portion that may be inserted within the bracket channels, such that the transfer plates are rotatably held within the channels of the brackets. In this way, the bottomrail may be pivoted as with Venetian-type shades while the transfer plates are engaged with the brackets.
The bottomrail is raisable and lowerable by manually moving the bottomrail relative to the headrail by engaging the transfer plates with the brackets. With the transfer plates so engaged, the cords are fixed at one end to the brackets and extend upward through the headrail, functioning as guide cords for the bottomrail and shade. Tension is applied to the cords by the operator pulling on the accessible end of the cords and then maintaining the position of the cords such as by locking the cords in a cord lock. The cord lock is preferably located in the headrail. With the cords in tension, friction acting between the cords and the bottomrail maintain the position of the bottomrail and shade when the bottomrail is manually moved.
When the cords are fixed at either end so that the cords are acting as guide cords, slack may be developed in the cord as the bottomrail is moved along the cords. A spring or similar means may be used to take up the slack in the cords. Preferably, the spring is provided within the bottomrail and connects to each cord.
The transfer plates may also be disengaged from the brackets, such as by removing the transfer plate extending portions from the channels of the brackets. With the transfer plates disengaged from the brackets, the bottomrail is then raisable and lowerable relative to the headrail by drawing the cords into and out of the headrail through manipulation of the ends of the cords accessible to an operator. In this mode of operation, the cords function as conventional lift cords. When the transfer plates are removed from the brackets, the transfer plates are drawn towards the bottomrail either through tensioning action of the cords and the spring, or through the cords being pulled by an operator, or the weight of the bottomrail and/or the shade.
In a first preferred embodiment, an even number of cords are used. Each cord has one end which extends outward from the headrail and is accessible to an operator. Each cord then travels downward from the headrail through the window shades and into the bottomrail. Once in the bottomrail, half of the cords travel outward of a respective one of the opposed ends of the bottomrail and is connected to a respective transfer plate. A spring preferably engages all the cords as described above to pick up the slack in the cords. Thus, when the transfer plates are engaged with the brackets, and the cords are functioning as guide cords, the cords and spring provide tension in the guide cords which increases frictional contact between the guide cords and the bottomrail. This tensioning of the guide cords assists in retaining the bottomrail in its selected position relative to the cords through various positions of being raised and lowered. Furthermore, when the transfer plates are disengaged from the brackets, and the cords are functioning as lift cords, the cord tensioning means helps to draw the transfer plates closer to the end of the bottomrail so that the transfer plates do not hang loosely from the bottomrail particularly in certain window coverings where the bottomrail is supported by the window covering, such as the ladders in venetians.
An alternative to the first preferred embodiment is substantially similar to the first embodiment except that instead of or in addition to the use of friction between the cords and the bottomrail, cord locks may be used to maintain the position of the bottomrail once it is raised and lowered relative to the cords when the transfer plates are engaged with the brackets and the cords are functioning as guide cords. Such position maintaining means should be releasable when it is desired to move the bottomrail relative to the cords. One or more, and preferably two cord locks may be used as the position mounting means in which such cord locks are preferably provided at the opposed ends or sides of the bottomrail. Other position maintaining means may be used which may be actuated by an operator while the operator is supporting or otherwise positioning the bottomrail. For example, the cords may be released from the locks by tilting the bottomrail from its normal horizontal position to an angled position.
In another alternative to the first preferred embodiment also substantially similar to the first preferred embodiment instead of or in addition to the spring and/or the cord locks, a clamp may be used to secure the position of the bottomrail relative to the headrail when the transfer plates are engaged with the brackets and the cords are functioning as guide cords. The clamp is attached to the bottomrail and clamps or secures to the cords, thereby preventing the bottomrail from moving relative to the cords. The clamp may be any suitable clamp-like device such as a spring loaded clamp and is preferably located in the middle of the bottomrail. Also, one or more handles may be provided on the bottomrail that disengage the cord locks when they are extended out from the bottomrail by the operator. Such handles preferably automatically collapse along the rail when released by the operator, engaging the cord locks.
In a second preferred embodiment, a single cord is used. The cord has one end which extends outward from the headrail and is accessible to an operator. An opposite end of the cord travels downward from the headrail passing through the shades and enters the bottomrail. Once in the bottomrail, the cord connects to both of the transfer plates. The single cord preferably connects to one transfer plate by looping through a hook or other aperture on that transfer plate. The cord then travels through the bottomrail and is affixed to the second transfer plate. In this embodiment, it is also preferred to include a means for securing the position of the bottomrail relative to the headrail when the transfer plates are engaged with the brackets and the cord is functioning as a guide cord. Tension may be supplied to the lift cords by adjusting the lift cords so that the bottomrail does not extend completely to the brackets and pulling the bottomrail downward and engaging the brackets. A spring can moderate and provide consistent tension in the cord, maintaining the correct amount of frictional contact between the cord and the bottomrail and thus retaining the bottomrail in a selected position relative to the cord.
An alternative to the second preferred embodiment is substantially similar to the second preferred embodiment. However, as an alternative to or in addition to the tensioning spring, one or more, and preferably two cord locks may be provided in the bottomrail to maintain the position of the bottomrail relative to the headrail when the transfer plates are engaged with the bracket channels and the cord is functioning as a guide cord. The cord locks are preferably disposed at opposite ends of the bottomrail.
Yet another alternative to the second preferred embodiment is substantially similar to the second preferred embodiment. However, in addition to or as an alternative to the spring and/or the cord locks, a clamp may be provided within the bottomrail for maintaining the position of the bottomrail relative to the headrail when the transfer plates are engaged with the bracket channels and the cord is functioning as a guide cord. The clamp is attached to the bottomrail and clamps or secures to the cord, thereby preventing the bottomrail from moving relative to the cord.
For any of the above embodiments, it is preferred to include a method for maintaining the position of the bottomrail relative to the headrail when the transfer plates are disengaged from the brackets such that the cords are functioning as lift cords. Although any suitable means for maintaining the position of the bottomrail relative to the headrail may be used, it is preferred to use a cord lock preferably provided in the headrail.
The bottomrail preferably has a ledge that extends outward at opposed ends from longitudinally extending upper, front and back surfaces of the bottomrail. The transfer plates each preferably have a flat portion and a generally circular extending portion which extends outward from the flat portion. With this preferred combination of bottomrail ledge and transfer plate configuration, the bottomrail may be moved upward relative to the transfer plates when the transfer plates are engaged with the brackets, but when the bottomrail is moved forward (away from the window) the flat portions of the transfer plates seat adjacent the back ledge of the bottomrail and the transfer plates may be moved forward and disengaged from the brackets. Conversely, when the bottomrail is moved backwards (toward the window) the plates are carried with it and can thus be engaged with the brackets. When the bottomrail is moved toward the window, the transfer plates will be carried with it if they are not already engaged in the brackets. Therefore, the ledges on the bottomrail capture the transfer plates in all directions of motion except straight up. There are preferably some detents on the side ledges that retain the transfer plates except when they are engaged in the brackets and provide sufficient resistance and can snap past the detents.
Other objects and advantages of the invention will become apparent from a description of certain present preferred embodiments thereof shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 as schematic depiction of a first preferred window shade assembly.
FIG. 2 is a schematic depiction of the window shade assembly of FIG. 1 shown partially raised in the guide cord mode of operation.
FIG. 3 is a schematic depiction of the window shade assembly of FIG. 1 shown partially raised in the lift cord mode of operation.
FIG. 4 is a front view taken in cross section of a portion of the window shade assembly showing the cooperation between the cord, bottomrail, transfer plate and bracket.
FIG. 5 is a front elevational view of a preferred transfer plate.
FIG. 6 is a perspective view of a preferred bracket.
FIG. 7 is a schematic depiction of the window shade assembly of FIG. 1 in the guide cord mode of operation showing an alternative means for retaining the position of the bottomrail.
FIG. 8 is a schematic depiction of a second preferred window shade assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present window shade assembly incorporates a headrail, a bottomrail, shades provided between the headrail and bottomrail, and one or more cords running through the headrail, shades and bottomrail. The present window shade assembly allows for alternate actuation means for raising and lowering the window shades. Thus, the cords may be used as lift cords in which the bottomrail and shades are raised by pulling on the lift cords, or as guide cords in which the bottomrail and shades may be raised and lowered by manipulation of the bottomrail. This alternate actuation means is provided without the need to disassemble or modify the window shade assembly structure or installation. In either case, raising or lowering the bottomrail directly or indirectly raises or lowers the shades. As is typical, with such window shade assemblies, it is preferred that the cords pass through the window shade so as to keep the window shade in a vertical stack when raised and lowered.
Referring first to FIG. 1, a first preferred embodiment of the window shade assembly 10 is shown. The window shade assembly 10 has a headrail 12, a bottomrail 14 and a section of window shade material (not shown) provided therebetween. Headrail 12 is fixed in its position by being secured to the surrounding window frame structure or the wall structure surrounding the window shade assembly or to the window sides or sills (collectively designated 32). The window shade assembly 10 also has a first cord 16 and a second cord 18.
Each of the cords 16, 18 have a first end 20 and a second end 22. The first ends 20 of the cords 16, 18 travel out of the headrail 12 and are accessible to an operator. The cords 16, 18 are provided through the headrail 12, extend downward preferably vertically at selected locations from the headrail 12 and enter the bottomrail 14. The second ends 22 of cords 16, 18 then exit from respective opposed ends 34, 36 of bottomrail 14. The second end 22 of the first cord 16 then exits a first end 34 of bottomrail 14 and is affixed or otherwise engaged to a first transfer plate 24. Similarly, the second cord 18 enters the bottomrail 14 and travels out of a second end 36 of the bottomrail 14 and is attached or otherwise engaged to a second transfer plate 26. The second ends 22 of the cords 16, 18 are affixed to the transfer plates 24, 26, by any suitable means, such as by passing through an aperture in the transfer plates 24, 26 and having the distal ends of the cords 16, 18 knotted as will be described in more detail below.
Although the preferred embodiments are shown and described in terms of two opposed ends to each cord, it is distinctly understood that at either "end" of the cords, the cords may be looped in which the loops are considered ends of the cords. Thus, for example, the first end 20 of the cords 16, 18 after exiting the headrail 12 may be looped and extend back into the headrail 12. The looped portion of cords 16, 18 extending outward of the headrail 12 and being accessible to an operator would thus be the first end 20 of cords 16, 18. Similarly, the second ends 22 of cords 16, 18 may be looped and pass through hooks or apertures (not shown in FIG. 1) in the transfer plates 24, 26 and then travel outward away from transfer plates 24, 26. The cords 16, 18 would thus be engaged to transfer plates 24, 26 by being looped through them.
The first transfer plate 24 is engageable and disengageable with a first bracket 28. Likewise, the second transfer plate 26 is engageable and disengageable with a second bracket 30. Brackets 28, 30 are secured to the surrounding window frame structure 32. Thus, the brackets 28, 30 are fixed in their position relative to the headrail 12.
Transfer plates 24, 26 are engageable and disengageable with the respective brackets 28, 30 by any suitable means. The preferred means is by providing the brackets 28, 30 with respective channels 38 (not shown in FIG. 1) through which portions of the transfer plates 24, 26 may be inserted and removed as will be described in more detail below.
Although the preferred embodiment describes engaging and disengaging the transfer plates 24, 26 with respective brackets 28, 30 in order to secure the positions of the transfer plates 24, 26, any suitable means for securing the position of transfer plates 24, 26 may be used. Thus, although it is preferred to provide brackets 28, 30 which are secured to the surrounding window frame structure 32, the transfer plates 24, 26 may be engageable and disengageable directly to the surrounding window frame structure 32. Thus, channels, indentations or other apertures may be provided directly upon the surrounding window frame structure 32.
Referring next to FIG. 2, the operation of the window shade assembly 10 is shown in the guide cord mode of operation. With the transfer plates 24, 26 engaged with respective brackets 28, 30, the cords 16, 18 remain in a fixed position and therefore act as guide cords. Movement of the bottomrail 14 upward towards the headrail 12 allows bottomrail 14 to travel over cords 16, 18 which remain stationary. Note that in the guide cord mode of operation, it is not necessary for an operator to pull or otherwise manipulate the first end 20 of cords 16, 18, except to adjust the tension in the cords 16, 18, if necessary. As the bottomrail 14 is moved upward toward headrail 12, first end 34 of bottomrail 14 separates from first transfer plate 24 which is in engagement with first bracket 28. Similarly, second end 36 of bottomrail 14 separates from second transfer plate 26 which is in engagement with second bracket 30. With transfer plates 24, 26 in engagement with brackets 28, 30, the second ends 22 of cords 16, 18 are retained in a fixed position. Cord lock 44 prevents the first ends 20 of cords 16, 18 from traveling into headrail 12 when the window shade assembly is in guide cord mode. Cord lock 44 therefore establishes the tension in cords 16, 18 by maintaining the position of the first ends 20 of cords 16, 18. Thus, in this mode of operation, the first and second ends 20, 22 of cords 16, 18 are fixed. As noted above, any suitable cord lock, cleat, or clamping device may be used for this purpose.
In the guide cord mode of operation, it is necessary to provide a means for retaining the selected position of the bottomrail 14 relative to the headrail 12 once bottomrail 14 has been moved. Furthermore, in either mode of operation, it is preferred that the cords 16, 18 are kept relatively taut. Thus, means for maintaining the proper tension (i.e., taking up the slack) of the cords 16, 18 over a wide range of positions of the bottomrail 14 along the cords 16, 18 is preferably provided. The preferred means of maintaining the proper tension on the cords 16, 18 is through the use of a spring 40. Spring 40 connects the two cords 16, 18 and spring 40 may or may not be secured to the bottomrail 14. The frictional contact between cords 16, 18 and the bottomrail 14 serves to hold the position of the bottomrail 14.
As an alternative or in addition to the friction between the bottomrail and the cords 16, 18, other means for retaining the bottomrail 14 in selected positions relative to the headrail 12 may be used. Such other retaining means may include cord locks 42 (shown in dotted line). Any suitable type of cord lock device may be used, such as a cam-like tumbler, jaw pins or those having a jaw-like cord lock structure. Examples of suitable cord locks are described in U.S. Pat. No. 4,660,612 to Anderson, U.S. Pat. No. 4,443,915 to Niemeyer, U.S. Pat. No. 4,413,664 to Istha and U.S. Pat. No. 5,275,222 to Judkins which are herein incorporated by reference.
Referring next to FIG. 3, the lift cord mode of operation is shown. When the transfer plates 24, 26 are disengaged from their respective brackets 28, 30, the window shade assembly 10 is in a lift cord mode of operation. With the transfer plates 24, 26 thus disengaged, an operator pulling upon the first ends 20 of cords 16, 18 causes the transfer plates 24, 26 and the bottomrail 14 to be pulled upward towards the headrail 12.
In this lift cord mode of operation, means are provided for maintaining the position of the bottomrail 14 relative to the headrail 12. Preferably cord lock 44 is provided for this function. Cord lock 44 is preferably provided in the headrail 12. Lowering bottomrail 14 and re-engagement of transfer plates 24, 26 with brackets 28, 30 again places the window shade assembly into the guide cord mode.
The preferred means of engagement and disengagement of the transfer plates 24, 26 with brackets 28, 30 will now be described with reference to FIGS. 4-6. Referring first to FIGS. 4 and 5, the second transfer plate 26 is shown. Transfer plate 26 preferably has a flat portion 46 and an extending portion 48 which extends outward from flat portion 46. As can be seen best in FIG. 5, extending portion 48 is preferably circular. As can be seen best in FIG. 4, extending portion 48 is also preferably beveled. An aperture 50 runs through the length of transfer plate 26. Cord 18 may be affixed to transfer plate 26 by traveling through aperture 50 and having the second end 22 of the cord 18 being knotted. For ease of illustration, only the second cord 18, the second transfer plate 26 and the second bracket 30 are shown. However, it is distinctly understood that the first cord 16, the first transfer plate 24 and the first bracket 28 are substantially similar and operate in substantially the same fashion as the second cord 18, second transfer plate 26 and second bracket 30.
Referring next to FIGS. 4 and 6, second bracket 30 may be seen. Bracket 30 has a channel 38 provided therethrough. Channel 38 is angled so as to mate with the transfer plate extending portion 48. Bracket 30 is affixed to the surrounding window frame structure or the surrounding wall structure 32 by any convenient means, but is preferably secured in place through the use of screws 30 provided through screw openings 52.
Referring next to FIGS. 4 and 5, bottomrail 14 has a longitudinally extending upper surface and longitudinally extending side surfaces. Bottomrail 14 preferably has a ledge 54 that extends outward at the opposed ends 34, 36 of bottomrail 14 as an extension of the upper surface 62 and side surfaces 64 of the bottomrail 14. The ledge 54 is preferably formed by inserting plugs 35 into respective bottomrail ends 34 and 36 (a plug 35 is only shown in the second end 36 of the bottomrail 14 in FIG. 4 although the plug incorporated with the first end 34 would be substantially similar). Ledge 54 provides a means whereby the operator can move the transfer plates 24, 26, downward, forward or backward by moving the bottomrail 14. There is thus no need for the operator to touch or handle the transfer plates 24, 26.
It is preferred that the transfer plate flat portions 46 have sides 47 which are tapered or curved. Similarly, it is preferred that bottomrail ledge 54 be tapered or curved at the side surfaces 65. Thus, the tapered sides 47 of the transfer plate flat portions 46 lead into the bottomrail side ledges 65. It is also preferred to provide the bottomrail side ledges 65 with slight detents 70. The detents 70 retain the transfer plates 24, 26 within the bottomrail ledge 54. Preferably, the detents 70 or the bottomrail ledge side surfaces 64 or both are made of plastic or some other flexible material. In this way, as the transfer plates 24, 26 are inserted within the bottomrail ledge 54, the transfer plate side portions 46 will move the detents 70 and/or the bottomrail ledge side surfaces 64 outward so that the transfer plates may be snapped into place therein. In this way, the transfer plates 24, 26 may be maintained neatly in the bottomrail but may also be removed from the bottomrail ledge 54 when the transfer plates 24, 26 are engaged to the brackets 28, 30 and the bottomrail is moved upward towards the headrail 12. Furthermore, the detents 70 also allow the transfer plates 24, 26 to be maintained within the bottomrail during handling, shipping and installation.
Referring next to FIG. 7, an alternative means for retaining the position of bottomrail 14 relative to headrail 12 when the window shade assembly 10 is in the guide cord mode is shown. A clamp 56 is preferably provided in bottomrail 14. Cord 16, 18 preferably pass through or between clamp 56 and may be secured thereby. Preferably, clamp 56 may have an extending portion that can act as a handle and be manipulated by an operator to move the bottomrail 14. Clamp 56 may be any clamp type device such as a spring biased clamp such that when the operator releases the clamp 56, the clamp 56 automatically clamps or secures to the cords 16, 18.
However, it remains aesthetically desirable to have springs attached to the cords 16, 18 to maintain tension in the cords 16, 18 particularly the section of cords 16, 18 between the transfer plates 24, 26 and the bottomrail 14 when the window shade assembly is in the guide cord mode.
Referring next to FIG. 8, a second preferred embodiment of window shade assembly 110 is shown. The second preferred window shade assembly 110 operates in substantially similar fashion as the first preferred window shade assembly 10 in that window shade assembly 110 has a headrail 112, a bottomrail 114 and a second of window shade material (not shown) provided therebetween. Headrail 112 is fixed in its position by being secured to the surrounding window frame structure or the wall structure surrounding the window shade assembly or to the window sills or sides (collectively designed as 32). However, window shade assembly 110 has a single lift cord 117. Lift cord 117 has a first end 120 and a second end 122. The first end 120 of the lift cord 117 travels out of the headrail 112 and is accessible to an operator. The cord 117 travels through the headrail 112, extends downward, preferably vertically, and enters the bottomrail 114. The cord 117 then exits a first end 134 of the bottomrail 114 and movable engages the first transfer plate 124. The preferred means for the cord 117 to movably engage the first transfer plate 124 is to have the cord 117 loop around a hook or opening 139. The second end 122 of cord 117 then travels through bottomrail 114 and affixes to second transfer plate 126. The second end 122 of cord 117 is affixed to the second transfer plate 126 by any suitable means, such as by passing through an aperture in the second transfer plate 126 and having the distal end of the cord 117 knotted as described above.
As described above in reference to the first preferred embodiment of the window shade assembly 10, the first and second transfer plates 124, 126 of the second preferred window shade assembly 110 are engageable and disengageable with respective first and second brackets 128, 130. Brackets 128, 130 are secured to the surrounding window frame structure 32. Thus, the brackets 128, 130 are fixed in their position relative to the headrail 112. The operation of the second preferred window shade assembly 110 is substantially similar to the operation of the first preferred window shade assembly in that it may operate in either a lift cord mode of operation or a guide cord mode of operation. With the transfer plates 124, 126 engaged with respective brackets 128, 130, the cord 117 remains in a fixed position and therefore acts as a guide cord. Movement of the bottomrail 114 towards the headrail 112 allows the bottomrail 114 to travel over the cord 117 which remains stationary.
As discussed above, in the guide cord mode of operation, it is necessary to provide a means for retaining the selected position of the bottomrail 114 relative to the headrail 112 once the bottomrail 114 has been moved. Thus, a means for tensioning the cord 117 is preferably provided. The preferred means of providing tension on the cord 117 is through the use of a cord lock and a spring 140. Spring 140 engages the cord 117 and is secured to the bottomrail 114. Alternative means for retaining the position of the bottomrail 114 relative to the headrail 112 may be used. For example, cord locks (not shown in FIG. 8) preferably provided on the bottomrail 114 or a clamp-type device (not shown in FIG. 8) also preferably provided on the bottomrail 14 may be used, each have been discussed with reference to the first preferred window shade assembly 10 above.
When the transfer plates 124, 126 are disengaged from their respective brackets 128, 130, the window shade assembly 110 is in a lift cord mode of operation. Thus, an operator pulling upon the first end 20 of cord 117 causes the transfer plates 124, 126 and the bottomrail 114 to be pulled upward towards the headrail 112.
In the lift cord mode of operation, means are provided for maintaining the position of the bottomrail 114 relative to the headrail 112. Cord lock 144 is provided for this function. Cord lock 144 is preferably provided in the headrail 112. Re-engagement of transfer plates 124, 126 with brackets 128, 130 again places the window shade assembly 110 into the guide cord mode. The transfer plates 124, 126 and brackets 128, 130 are substantially the same as to the transfer plates 24, 26 and brackets 28, 30 of the first preferred window shade assembly 10.
Although the window shade assembly 110 has been described in terms of the first transfer plate 124 having aperture 139 and the cord 117 being affixed to the second transfer plate 126, cord 117 may instead travel through second transfer plate 126 and attach to first transfer plate 124.
Other variations of the preferred embodiments may be made. For example, although the extending portion of the transfer plates are beveled and the bracket channel is correspondingly angled to receive the transfer plate extending portion, it is distinctly understood that any shape and size of the extending portion and bracket channel may be used, so long as the extending portion may be retained within and removed from the bracket channel.
Also, although the preferred embodiments have been shown and described with one or two cords, any number of cords may be used. When more than two cords are used with the window shade assembly, more than one cord must engage a single transfer plate.
Furthermore, as described above, although the preferred embodiments utilize brackets, any means for selectively securing the position of the transfer plates relative to the headrail may be used. Thus, a channel as described with respect to the brackets or any type of aperture may be provided upon the surrounding window frame structure.
While certain present preferred embodiments have been shown and described, it is distinctly understood that the invention is not limited thereto but may be otherwise embodied within the scope of the following claims. | The window shade assembly has a headrail and a bottomrail that are spaced from one another and has window shade material provided therebetween. The window shade assembly has one or more cords traveling through the headrail and through the bottomrail. A first end of each cord is accessible to an operator and a second end of each cord is connected to one of a pair of transfer plates. A pair of brackets is also provided, each having a channel running therethrough. The transfer plates and channels are sized and configured so that the transfer plates are engageable and disengageable with a respective bracket through the channel of that bracket. The transfer plates and channels are also sized and configured so that the transfer plates are rotatably held within the brackets when the transfer plates are inserted within the channels. The bottomrail is raisable and lowerable through manual movement of the bottomrail once the transfer plates are engaged with the brackets, such that the cords act as guide cords for the bottomrail and shade. The bottomrail is also raisable and lowerable by drawing the cords into and out of the headrail once the transfer plates are disengaged from the brackets. | 4 |
This is a continuation of application Ser. No. 65,700 filed Aug. 10, 1979, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for driving electromagnetic devices, and in particular, electromagnetic injection valves in internal combustion engines which are provided with actuating pulses.
Apparatuses are known in which current flow is sent through the magnetic coil of the electromagnetic device at the onset of an actuating pulse, in order to assure rapid attraction on the part of the magnetic core. In these apparatuses, very high currents must sometimes be used because the starting point for actuation is a zero current flow. These high current flows are expensive to provide. With these apparatuses there is not, available, moreover, an energy source capable of furnishing the desired high current flows with the necessary rapid increase in current. If such a current source is not available, then a sufficiently rapid increase in current cannot be achieved, and thus a rapid attraction of the magnetic core is foreclosed, so that in turn, the onset of injection, for instance, in the case of electromagnetic injection valves, is delayed.
OBJECTS, SUMMARY AND ADVANTAGES OF THE INVENTION
It is an object of the invention to improve upon the known apparatuses by a bias or an advanced magnetization of the electromagnetic device in order to attain the desired effect at the onset of an actuating pulse with a relatively small amount of supplementary energy.
In order to attain the desired linear relationship between the duration of the actuating pulse and, for example, the opening time of an injection valve, it is desirable to provide not only a secure and precisely timed opening of the injection valve but a correspondingly secure and precisely timed closing of the valve as well. With the valve closing time there is associated a release lag, i.e., the magnetic core does not react instantaneously. The release lag, which is dictated by the laws of physics, must thus be kept very short to maintain the desired precision. In the case of actuating pulses which occur in rapid succession, there is the problem that the open-valve period, because of the release lag, is not yet entirely terminated at the beginning of the next advanced magnetization phase. In the borderline case, with synchronized control, this would result in a so-called hydraulic continuous-wave operation, which is to be avoided. That is, a condition would be created during which the valve fails to completely close between pulses.
It is, therefore, another object of the invention to provide measures which assure both a secure and precisely timed onset and corresponding end to the opening period of the device, and to do so at the highest possible rate of repetition of the actuating pulses.
The apparatus, in accordance with the invention, has the advantage over the known apparatuses of a high degree of identity between the actuating pulse and the behavior of the electromagnetic device.
A further advantage is that only a very limited increase in current is required for the attraction of the core of the electromagnetic device, so that the appropriate switching elements can be of low output dimensions.
The control of advanced magnetization, the duration of which is a function of operational characteristics of the engine, accomplishes a sure release of the core even with a rapid succession of pulses and thus, for example, a sure interruption of the fuel supply to an internal combustion engine. It has proved to be particularly advantageous when using the apparatus in connection with electromagnetic injection valves in internal combustion engines for the advanced magnetization to be dependent, for example, on rpm, load and/or temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block circuit diagram of the apparatus for driving an electromagnetic switching system;
FIG. 2 shows the relationship between the duration of the actuation pulse in an electromagnetic injection valve and the injection fuel quantity with and without advanced magnetization;
FIG. 3 schematically illustrates the current profile with the release time of the valve current, in order to obtain a sure release;
FIG. 4 schematically illustrates the valve current profile with the advanced magnetization time being dominant, in order in each case, to obtain an optimal attraction of the injection valve;
FIG. 5 shows a block circuit diagram of the apparatus in accordance with the invention; and
FIG. 6 illustrates the pulse diagrams pertaining to the apparatus of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, the apparatus for driving electromagnetic injection valves in internal combustion engines is shown schematically. The apparatus includes a pulse generator stage 10, with various operational characteristics of the engine as inputs. The pulse generator stage 10 furnishes, in a known manner, an injection pulse of length ti. The output 11 of the pulse generator stage 10 is coupled with an input 12 of an electronic switching element 13, to whose output 14 in turn the electromagnetic injection valve 15 is connected. A magnetization period control circuit arrangement 16 receives the injection pulses from the pulse generator stage 10 via an input 17 and a period duration signal 1/n relating to the rpm of the engine via an input 18.The input 18 is intended to indicate the advanced magnetization dependent on operational characteristics of the magnetic valve, although in the circuit layout of FIG. 5, this separate input 18 can be omitted. On the output side, this control circuit arrangement 16 for the advanced magnetization time is coupled to a further input 19 of the electronic switching element 13.
In FIG. 2, the fuel quantity q ejected by an electromagnetic injection valve is plotted against the duration of the injection pulse ti. The curve marked I shows the fuel quantity without advanced magnetization of the injection valve and the curve marked II, in a corresponding manner, shows the injected quantity with advanced magnetization having a constant duration. Both curves are distinguished by a non-linear initial section, a straight section, and a non-linear terminal section. With advanced magnetization, the terminal section of curve II splits, depending upon whether the advanced magnetization time is to be constant or the shutoff time is to be constant. It can be seen that the injection quantity differs at an identical duration of the injection pulse ti, with the injected quantity being larger in the case of driving the injection valve with advanced magnetization (curve II) than in the case of driving the injection valve without advanced magnetization (curve I). This results because the injection valve is actuated more rapidly at the onset of the injection pulse with advanced magnetization and thus can inject fuel more rapidly, while the end of injection is identical in both variants.
The vertical broken line shown on the right-hand side of FIG. 2 indicates continuous-wave operation, that is, an injection time T which corresponds to the period duration of the injection signal 1/n.
Curve II shows the course of the fuel quantity injected against the injection time at a constant advanced magnetization time T1 (see also FIGS. 3 and 4). In comparison with curve I, curve II is simply shifted parallel. If T1 is selected to be long enough, then a further lengthening does not cause any further shortening of the magnetization time. This case is illustrated in FIG. 2, curve II.
Curve III shows the conditions at a constant shutoff time T2 (see also FIGS. 3 and 4). At large ti values, the effective advanced magnetization time is shortened, because the next advanced magnetization appears before the preceding injection pulse has run its course. Curve III thus tends, with increasing ti, to coincide with curve I (without advanced magnetization). For smaller ti values (left of point A), at a constant time T2 the resulting advanced magnetization time T1 is longer than what corresponds to the threshold value of curve II; that is, curve III tends to coincide with curve II.
Curve IV has the longest linear section extending into the high range for ti; in order to realize curve IV, the shutoff time and/or the time of advanced magnetization is controlled. For smaller ti values (left of point A), a more-rapid magnetization time than that corresponding to curve II cannot be attained; that is, curve IV tends to coincide with curve II.
FIG. 3 schematically illustrates a profile of the current flow through the magnetic valve in the event that the release time, T2, of the valve, that is, the interval between pulses, and thus between injections is dominant. The individual diagrams a through c of FIG. 3 show the current profile at varying frequencies of the injection pulses of duration ti. For the purposes of clarification, the onset of a particular injection pulse (that is, the time at which the current value is sufficiently high to move the magnetic core) is indicated approximately at the center of FIG. 3 for each diagram, and the pulse releases or terminations indicated at the left-hand edge, mark the end of the particular injection time. At increasing rpm and with a constant pulse interval between the end of the injection pulse and the beginning of the next advanced magnetization, there results a shorter and shorter advanced magnetization time interval T1. In the diagram of FIG. 3a, the advanced magnetization is fully effective; in the diagram of FIG. 3b, advanced magnetization is only partially effective, and in the diagram of FIG. 3c, it is entirely absent. This pattern (FIG. 3c) corresponds in principle to the current profile in a valve which is driven in accordance with the known apparatuses.
FIG. 4 schematically illustrates the current profile through the magnetic valve at a constant advanced magnetization time T1. The pulse releases on the left-hand side of FIG. 4 again characterize the end of an injection pulse. The release time of the magnetic valve is indicated by the reference tab. It can be seen that in the diagram of FIG. 4a, the valve release, that is the time required for the valve to close against its valve seat, is undisturbed; in the diagram of FIG. 4b there is shown a condition where the valve release is complete at precisely the beginning of the next advanced magnetization period, that is, the valve release is undisturbed; and in contrast in the diagram of FIG. 4c, the valve release is disturbed, so that the danger is present in this case of a hydraulic continuous-wave operation. FIG. 4c makes clear the necessity for the control of an advanced magnetization, in accordance with operational characteristics, of the magnetic valve coil. This is particularly important when the period duration of the injection pulses assume an order of magnitude like that of the injection pulses. This is possible, especially when the total fuel quantity supplied to an internal combustion engine is intended to be injected via a single valve.
FIG. 5 shows, in a block circuit diagram, one possible embodiment of an apparatus for achieving the curve patterns of FIG. 3; that is, a control of the advanced magnetization time in one injection valve in accordance with operational characteristics. The output of the pulse generator stage 10 is coupled to the trigger input of a first timing element or monostable multivibrator 20, via a first inverter 21 with a second timing element or monostable multivibrator 23, and via a second inverter 22 with a third timing element or monostable multivibrator 24. The output of the pulse generator stage 10 is also connected with a first input of a NOR-gate 25 and the base of a switching transistor 26 lying in series with the magnetic valve 15. Lying parallel to the emitter-collector path of this transistor 26 are both a series circuit comprising a resistor 28 and a capacitor 29 and a series circuit comprising a resistor 30 and the collector-emitter path of a transistor 32. The end of the magnetic valve 15 remote from this parallel layout is connected via a resistor 33 with a positive line 34 of a voltage supply system.
The output of the NOR-gate 25 is coupled with the base of the transistor 32. The second input of this NOR-gate 25 is connected with the output of the monostable multivibrator 24.
The output of the second monostable multivibrator 23 is conveyed to the base of a transistor 36, whose emitter is connected to ground and parallel to whose emitter-collector path are a capacitor 37 and a Zener diode 38. The collector of the transistor 36 and thus the capacitor 37 and Zener diode 38 are connected via a resistor 39 with the positive line 34. The voltage across the capacitor 37 can be transmitted by means of a switch 40 to the input of a coupler stage 41. The switch 40 receives its switching signal via a control input 42 from the output of the first monostable multivibrator 20. On the output side, the coupler stage 41 is connected via a diode 45 with a capacitor 46, which in turn is coupled to the control input of the third monostable multivibrator 24.
The mode of operation of the circuit of FIG. 5 is effectively explained with the aid of the pulse diagrams of FIG. 6. In FIG. 6a, the output signal of the pulse generator stage 10 is shown; that is, FIG. 6a shows the injection pulses of length ti. The output signal of the first monostable multivibrator 20 is shown in FIG. 6b. Correspondingly, FIGS. 6c and 6d show the output signals of the second and third monostable multivibrators 23 and 24, and it will be appreciated that the first monostable multivibrator 20 is triggered by the leading edge of the injection signal of FIG. 6a and the second and third monostable multivibrators 23 and 24 are triggered by the trailing edge of the injection signal of FIG. 6a. The horizontal double-headed arrow at the trailing edge of the output signal of the third monostable multivibrator 24 indicates the controlling of this signal in accordance with the voltages of the capacitors 46 and 37 and thus indicates an rpm dependency.
FIG. 6e shows the profile of the voltage variation across the capacitor 37. For the pulse duration of the output signal of the second monostable multivibrator 23 (FIG. 6c), the subsequent transistor 36 conducts, and thus, no voltage signal is present across the capacitor 37. During the pulse intervals of the output signal of the second monostable multivibrator 23, however, the voltage signal across the capacitor 37 increases, through the constant resistor 39 to the constant supply voltage on the positive line, and in an exponential fashion up to the next trailing edge of the rising signal. The steepness of this voltage increase is in accordance with the timing constant derived from resistor 39 and capacitor 37.
FIG. 6f shows the driving signal of the switching transistor 26, which is identical to the injection signal having the duration ti of FIG. 6a. In FIG. 6g, the potential at the base of the transistor 32 is shown. Because of the logical connection of the injection signal from the output 11 of the pulse generator stage 10 and the output signal of the third monostable multivibrator 24, there is a positive signal at the base of the transistor 32 only when neither an injection signal, in accordance with FIG. 6a, nor the output signal of the third monostable multivibrator 24, in accordance with FIG. 6d, appears.
Finally, FIG. 6h shows the flow of current through the magnetic coil 15 of the magnetic valve. The advanced magnetization by means of a small current can be seen before the duration times of the injection pulses ti. The double-headed arrow shown during the ascending edge of the advanced magnetization current indicates a shift in the timing of this ascending edge on the basis of the output signal of the third monostable multivibrator 24, for the signal behavior of which, in turn, the signal behavior of the second monostable multivibrator 23 and the timing behavior of resistor 39 and capacitor 37 represent the standard. The trailing edge of the magnetic current may be determined as to its function by the RC elements 28, 29. This is illustrated by the double-headed arrow bearing the identifying reference f (28,29).
The voltage signal of capacitor 37 carried over at the onset of the injection pulse, during the switching time of the first monostable multivibrator 20, which signal is dependent on rpm, controls via the third monostable multivibrator 24 the blocking time for the transistor 32 at the end of the injection pulse. Simultaneously, by means of the second monostable multivibrator 23, the capacitor 37 is rapidly discharged by means of the transistor 36, in order to be able to form the rpm-dependent signal during the ti interval.
The pulse diagrams of FIGS. 3 and 4 provide for a division of the valve current in half over the duration of the injection pulse in such a manner that at the onset an increased attraction current is furnished and subsequently a so-called maintenance current (lower level current) flows through the magnetic valve. This progression serves to permit the application of the necessary energy during the stroke phase of the core of the magnetic valve and subsequently, during the maintenance phase which requires less energy, to permit accordingly less current to flow. In the circuit of FIG. 5, this progression is not provided, because it is particularly the controlling of the advanced magnetization which is the subject of the invention. A combination of the subject of FIG. 5, that is, the controlling of the advanced magnetization, with a known possible realization of the current progression corresponding to the diagrams of FIGS. 3 and 4, such as a current-controlled terminal stage, is not a matter of any difficulty for the person familiar with the art.
The foregoing relates to a preferred embodiment of the invention, it being understood that other embodiments and variants thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. For example, the timing elements are chosen to preferrably be monostable multivibrators, although other equivalent timing elements may be employed. | An apparatus is proposed for driving electromagnetic devices, in particular electromagnetic injection valves in internal combustion engines. The apparatus includes a signal source for actuating pulses and is characterized in that at least one timing circuit is provided for advanced magnetization, preferably dependent on operating characteristics, of the electromagnetic device. The apparatus achieves the most linear possible relationship between the duration of the actuating pulse and, for example, the opening time of the injection valve. In this manner, the fuel quantity to be supplied to the internal combustion engine can be more precisely dosed and the operational behavior of the engine can be made optimal. Because of the advanced magnetization, the electromagnetic injection valve, for example, attracts more rapidly at the onset of the actuating pulse, because the magnetic coil has already stored a certain amount of energy, which lies somewhat below that amount which is required for attraction on the part of the magnetic core and thus for the ejection of fuel. | 7 |
This is a continuation-in-part of U.S. patent application Ser. No. 09/730,257, filed Dec. 5, 2000, now U.S. Pat. No. 6,489,415 which claims the benefit of U.S. Provisional Application Serial No. 60/174,151, filed on Dec. 31, 1999.
BACKGROUND OF THE INVENTION
By virtue of its high level of crystallinity, trans-1,4-polybutadiene (TPBD) is typically a thermoplastic resin. Because it contains many double bonds in its polymeric backbone, TPBD can be blended and cocured with rubber. TPBD is similar to syndiotactic-1,2-polybutadiene in this respect. Even though trans-1,4-polybutadiene having a high melting point is a thermoplastic resin, it becomes elastomeric when cured alone or when cocured with one or more rubbers.
Good molecular weight control can normally be achieved by utilizing an anionic polymerization system to produce TPBD. There is typically an inverse relationship between the catalyst level utilized and the molecular weight attained when anionic polymerization systems are used. Such an anionic polymerization system is disclosed in U.S. Pat. No. 4,225,690. The catalyst system disclosed therein is based on a dialkylmagnesium compound which is activated with a potassium alkoxide. However, such catalyst systems have not proven to be commercially successful.
TPBD is normally prepared utilizing transition metal catalysts or rare earth catalysts. The synthesis of TPBD with transition metal catalysts is described by J. Boor Jr., “Ziegler-Natta Catalysts and Polymerizations,” Academic Press, New York, 1979, Chapters 5-6. The synthesis of TPBD with rare earth catalysts is described by D. K. Jenkins, Polymer, 26, 147 (1985). However, molecular weight control is difficult to achieve with such transition metal or rare earth catalysts and monomer conversions are often very modest.
Japanese Patent Application No. 67187-1967 discloses a catalyst system and technique for synthesizing TPBD consisting of 75 to 80 percent trans-1,4-structure and 20 to 25 percent 1,2-structure. The catalyst system described by this reference consists of a cobalt compound having a cobalt organic acid salt or organic ligand, an organoaluminum compound and phenol or naphthol. Gel formation is a serious problem that is frequently encountered when this three-component catalyst system is utilized in the synthesis of TPBD. Gelation is a particularly serious problem in continuous polymerizations. By utilizing this catalyst system and technique, TPBD can be synthesized in a continuous process with only minimal amounts of gel formation.
U.S. Pat. No. 5,089,574 is based upon the finding that carbon disulfide will act as a gel inhibitor in conjunction with three component catalyst systems which contain an organocobalt compound, an organoaluminum compound and a para-alkyl substituted phenol. U.S. Pat. No. 5,089,574 also indicates that conversions can be substantially improved by utilizing para-alkyl substituted phenols which contain from about 12 to about 26 carbon atoms and which preferably contain from about 6 to about 20 carbon atoms.
U.S. Pat. No. 5,089,574 more specifically reveals a process for synthesizing trans-1,4-polybutadiene in a continuous process which comprises continuously charging 1,3-butadiene monomer, an organocobalt compound, an organoaluminum compound, a para-substituted phenol, carbon disulfide and an organic solvent into a reaction zone; allowing the 1,3-butadiene monomer to polymerize in said reaction zone to form the trans-1,4-polybutadiene; and continuously withdrawing the trans-1,4-polybutadiene from said reaction zone.
U.S. Pat. No. 5,448,002 discloses that dialkyl sulfoxides, diaryl sulfoxides and dialkaryl sulfoxides act as molecular weight regulators when utilized in conjunction with cobalt-based catalyst systems in the polymerization of 1,3-butadiene monomer into TPBD. U.S. Pat. No. 5,448,002 reports that the molecular weight of the TPBD produced decreases with increasing levels of the dialkyl sulfoxide, diaryl sulfoxide or dialkaryl sulfoxide present as a molecular weight regulator.
U.S. Pat. No. 5,448,002 specifically discloses a process for the synthesis of trans-1,4-polybutadiene which comprises polymerizing 1,3-butadiene monomer under solution polymerization conditions in the presence of at least one sulfoxide compound selected from the group consisting of dialkyl sulfoxides, diaryl sulfoxides and dialkaryl sulfoxides as a molecular weight regulator and in the presence of a catalyst system which includes an organocobalt compound, an organoaluminum compound and a para-alkyl substituted phenol.
The presence of residual cobalt in TPBD made with cobalt-based catalyst systems is not desirable. This is because the residual cobalt acts as a prooxidant leading to polymer instability during storage. This is a particular problem in cases where the TPBD is stored in a “hothouse” prior to usage, which is a standard procedure in many industries, such as the tire industry. In any case, high levels of residual cobalt in the TPBD lead to problems with polymer stability.
Unfortunately, carbon disulfide is typically required as a gel-reducing agent in the synthesis of TPBD with cobalt-based catalyst systems. This is particularly true in the case of continuous polymerization systems. However, the presence of carbon disulfide in such systems reduces the level of catalyst activity and generally makes it necessary to increase the level of cobalt in the catalyst system. Thus, in cases where carbon disulfide is required for gel control, the level of cobalt needed is further increased. This accordingly leads to greater polymer instability.
Due to its high melting point, it is normally necessary to heat TPBD in order for it to be processed using conventional mixing equipment, such as a Banbury mixer or a mill mixer. This heating step is typically carried out by storing the trans-1,4-polybutadiene in a “hothouse” for a few days prior to its usage. During this storage period, the bails of the polymer are slowly heated to a temperature above about 104° F. (40° C.). At such temperatures, the polymer can be readily processed in standard mixing equipment. However, the TPBD typically undergoes undesirable oxidative crosslinking which leads to gelation during this long heating period. This oxidation can crosslink the TPBD to such a high degree that it cannot be processed utilizing standard mixing techniques. In other words, the oxidative gelation that occurs can destroy the polymer.
U.S. Pat. No. 5,854,351 discloses that TPBD which contains a processing oil can be rapidly heated by radio frequency electromagnetic radiation. The radio frequency waves used in such a heating process typically have a frequency that is within the range of about 2 to 80 MHz (megahertz). By utilizing such a technique, an 80-pound (30 kg) bail of TPBD can be rapidly heated to a temperature above 104° F. (40° C.) in a matter of minutes. During this rapid heating process, oxidative gelation does not occur to a significant degree. This is, of course, in contrast to conventional heating techniques where bails of TPBD are slowly warmed by convection heating to the required temperature over a period of days. During this long heating period, the TPBD undergoes highly undesirable oxidative crosslinking.
U.S. Pat. No. 5,854,351 more specifically discloses a technique for mixing trans-1,4-polybutadiene with at least one rubbery polymer which comprises: (1) heating the trans-1,4-polybutadiene to a temperature which is within the range of 105° F. (41° C.) to 200° F.(93° C.) by exposing it to electromagnetic radiation having a frequency in the range of about 2 MHz to about 80 MHz, wherein the trans-1,4-polybutadiene is oil-extended with at least 10 phr of a processing oil; and (2) mixing the trans-1,4-polybutadiene with said rubbery polymer before any portion of the trans-1,4-polybutadiene cools to a temperature below 104° F. (41° C.).
U.S. Pat. No. 5,100,965 discloses a process for synthesizing a high trans polymer which comprises adding (a) at least one organolithium initiator, (b) an organoaluminum compound, (c) a barium alkoxide and (d) a lithium alkoxide to a polymerization medium which is comprised of an organic solvent and at least one conjugated diene monomer.
U.S. Pat. No. 5,100,965 further discloses that high trans polymers can be utilized to improve the characteristics of tire tread rubber compounds. By utilizing high trans polymers in tire tread rubber compounds, tires having improved wear characteristics, tear resistance and low temperature performance can be made.
In commercial applications where recycle is required, the use of barium alkoxides can lead to certain problems. For instance, barium t-amylate can react with water to form t-amyl alcohol during steam-stripping in the polymer finishing step. Since t-amyl alcohol forms an azeotrope with hexane, it co-distills with hexane and thus contaminates the feed stream.
SUMMARY OF THE INVENTION
This invention is based upon the discovery that the problem of recycle stream contamination can be solved by synthesizing trans-1,4-polybutadiene utilizing a catalyst system which is comprised of (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) barium salts of cyclic alcohols, such as barium mentholate, and (ii) barium thymol, and (c) an organoaluminum compound. The problem of recycle stream contamination is solved by utilizing a barium salt of a cyclic alcohol as the barium compound in the catalyst system. Barium mentholate is highly preferred because it does not co-distill with hexane or form compounds during steam-stripping which co-distill with hexane. Since the boiling points of the cyclic alcohols generated upon the hydrolysis of their metal salts are very high, they do not co-distill with hexane and contaminate recycle streams. Additionally, such cyclic alcohols are considered to be environmentally safe. In fact, menthol (the hydrolyzed product of barium mentholate) is commonly used as a food additive.
The trans-1,4-polybutadiene made with such barium containing catalyst systems has a melting point that is within the range of about −30° C. to +30° C. Because the trans-1,4-polybutadiene synthesized with the catalyst system of this invention has a high melting point it does not need to be heated in a “hot-house” before it is blended with other rubbery polymers or utilized in making rubber products, such as tires. Additionally, the trans-1,4-polybutadiene is strain crystallizable and can be employed in manufacturing tire tread compounds that exhibit wear characteristics. The trans-1,4-polybutadiene also typically has a glass transition temperature which is within the range of about −97° C. to about −90° C., a number average molecular weight which is within the range of about 50,000 to about 200,000, and a Mooney ML 1+4 viscosity which is within the range of about 20 to about 110.
The present invention more specifically discloses a process for synthesizing trans-1,4-polybutadiene which comprises polymerizing 1,3-butadiene monomer in the presence of a catalyst system which is comprised of (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) a barium salt of a cyclic alcohol, and (ii) barium thymol, and (c) an organoaluminum compound.
The present invention further discloses a process for synthesizing trans-1,4-polybutadiene which comprises polymerizing 1,3-butadiene monomer in the presence of a catalyst system which is comprised of (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) a barium salt of a cyclic alcohol, and (ii) barium thymol, (c) an organoaluminum compound, and (d) a lithium salt of a cyclic alcohol.
This invention also reveals a process for synthesizing a trans-styrene-diene rubber which comprises a conjugated diolefin monomer and styrene monomer in the presence of a catalyst system which is comprised of (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) a barium salt of a di-alkylated cyclohexanol, and (ii) barium thymol, and (c) an organoaluminum compound.
The subject invention further discloses a process for synthesizing trans-styrene-diene rubber which comprises polymerizing a conjugated diolefin monomer and styrene monomer in the presence of a catalyst system which is comprised of (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) a barium salt of a di-alkylated cyclohexanol, and (ii) barium thymol, (c) an organoaluminum compound, and (d) a lithium salt of a cyclic alcohol.
The subject invention further discloses a process for synthesizing trans-styrene butadiene rubber which comprises copolymerizing 1,3-butadiene monomer and styrene monomer in the presence of a catalyst system which is comprised of (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) a barium salt of a di-alkylated cyclohexanol, and (ii) barium thymol, and (c) an organoaluminum compound.
The present invention also reveals a process for synthesizing trans-styrene-butadiene rubber which comprises polymerizing 1,3-butadiene monomer in the presence of a catalyst system which is comprised of (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) a barium salt of a di-alkylated cyclohexanol, and (ii) barium thymol, (c) an organoaluminum compound, and (d) a lithium salt of a cyclic alcohol.
DETAILED DESCRIPTION OF THE INVENTION
The polymerizations of the present invention will normally be carried out in a hydrocarbon solvent that can be one or more aromatic, paraffinic, or cycloparaffinic compounds. These solvents will normally contain from 4 to 10 carbon atoms per molecule and will be liquid under the conditions of the polymerization. Some representative examples of suitable organic solvents include pentane, isooctane, cyclohexane, methylcyclohexane, isohexane, n-heptane, n-octane, n-hexane, benzene, toluene, xylene, ethylbenzene, diethylbenzene, isobutylbenzene, petroleum ether, kerosene, petroleum spirits, petroleum naphtha, and the like, alone or in admixture.
In the solution polymerizations of this invention, there will normally be from 5 to 30 weight percent monomer in the polymerization medium. Such polymerization media are, of course, comprised of the organic solvent and the monomer. In most cases, it will be preferred for the polymerization medium to contain from 10 to 25 weight percent monomer. It is generally more preferred for the polymerization medium to contain 15 to 20 weight percent monomer. In cases where trans-1,4-polybutadiene is being synthesized the monomer employed is 1,3-butadiene. In cases where trans-styrene-butadiene rubber is being synthesized a combination of styrene and 1,3-butadiene will be used as the monomer.
Normally from about 5 weight percent to about 45 weight percent styrene and from about 55 weight percent to about 95 weight percent 1,3-butadiene will be used in making trans-styrene-butadiene rubber. More typically, from about 15 weight percent to about 35 weight percent styrene and from about 65 weight percent to about 85 weight percent 1,3-butadiene will be used in making trans-styrene-butadiene rubber. It is normally preferred for about 20 weight percent to about 30 weight percent styrene and from about 70 weight percent to about 80 weight percent 1,3-butadiene to be used in making trans-styrene-butadiene rubber. Trans-styrene-isoprene rubber can also be made by copolymerizing isoprene and styrene. Trans-styrene-isoprene-butadiene rubber can be made by the terpolymeriztion of styrene, 1,3-butadiene, and isoprene.
The trans-1,4-polybutadiene made utilizing the catalyst system and technique of this invention are comprised of repeat units that are derived from 1,3-butadiene. The trans-1,4-polybutadiene typically has a trans-microstructure content of about 60% to about 80%. The trans-1,4-polybutadiene made in accordance with this invention exhibits a low polydispersity. The ratio of the weight average molecular weight to the number average molecular weight of such trans-1,4-polybutadiene will typically be less than 1.5. It is more typical for the ratio of the weight average molecular weight to the number average molecular weight of the trans-1,4-polybutadiene to be less than about 1.3. It is normally preferred for the high trans-1,4-polybutadiene of this invention to have a ratio of weight average molecular weight to number average molecular weight which is less than about 1.2.
The trans-1,4-polybutadiene made in accordance with this invention will typically have a melting point which is within the range of about −20° C. to about 40° C. They also typically have a glass transition temperature that is within the range of about −97° C. to about −90° C.
The polymerizations of this invention are initiated by adding an organolithium initiator, an organoaluminum compound, and a barium salt of a cyclic alcohol to a polymerization medium containing the 1,3-butadiene monomer. Preferably, the polymerizations of this invention are initiated by adding an organolithium initiator, an organoaluminum compound, a barium salt of a cyclic alcohol, and a lithium salt of a cyclic alcohol. Such polymerization can be carried out utilizing batch, semi-continuous or continuous techniques.
The organolithium initiators employed in the process of this invention include the monofunctional and multifunctional types known for polymerizing the monomers described herein. The multifunctional organolithium initiators can be either specific organolithium compounds or can be multifunctional types which are not necessarily specific compounds but rather represent reproducible compositions of regulable functionality.
The amount of organolithium initiator utilized will vary with the molecular weight that is desired for the trans-1,4-polybutadiene being synthesized. However, as a general rule from 0.01 to 1 phm (parts per 100 parts by weight of monomer) of an organolithium initiator will be utilized. In most cases, from 0.01 to 0.1 phm of an organolithium initiator will be utilized with it being preferred to utilize 0.025 to 0.07 phm of the organolithium initiator.
The multifunctional initiators which can be used include those prepared by reacting an organomonolithium compounded with a multivinylphosphine or with a multivinylsilane, such a reaction preferably being conducted in an inert diluent such as a hydrocarbon or a mixture of a hydrocarbon and a polar organic compound. The reaction between the multivinylsilane or multivinylphosphine and the organomonolithium compound can result in a precipitate which can be solubilized if desired, by adding a solubilizing monomer such as a conjugated diene or monovinyl aromatic compound, after reaction of the primary components. Alternatively, the reaction can be conducted in the presence of a minor amount of the solubilizing monomer. The relative amounts of the organomonolithium compound and the multivinylsilane or the multivinylphosphine preferably should be in the range of about 0.33 to 4 moles of organomonolithium compound per mole of vinyl groups present in the multivinylsilane or multivinylphosphine employed. It should be noted that such multifunctional initiators are commonly used as mixtures of compounds rather than as specific individual compounds.
Exemplary organomonolithium compounds include ethyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-octyllithium, n-eicosyllithium, phenyllithium, 2-naphthyllithium, 4-butylphenyllithium, 4-tolyllithium, 4-phenylbutyllithium, cyclohexyllithium, and the like.
Exemplary multivinylsilane compounds include tetravinylsilane, methyltrivinylsilane, diethyldivinylsilane, di-n-dodecyldivinylsilane, cyclohexyltrivinylsilane, phenyltrivinylsilane, benzyltrivinylsilane, (3-ethylcyclohexyl) (3-n-butylphenyl)divinylsilane, and the like.
Exemplary multivinylphosphine compounds include trivinylphosphine, methyldivinylphosphine, dodecyldivinylphosphine, phenyldivinylphosphine, cyclooctyldivinylphosphine, and the like.
Other multifunctional polymerization initiators can be prepared by utilizing an organomonolithium compound, further together with a multivinylaromatic compound and either a conjugated diene or monovinylaromatic compound or both. These ingredients can be charged initially, usually in the presence of a hydrocarbon or a mixture of a hydrocarbon and a polar organic compound as a diluent. Alternatively, a multifunctional polymerization initiator can be prepared in a two-step process by reacting the organomonolithium compound with a conjugated diene or monovinyl aromatic compound additive and then adding the multivinyl aromatic compound. Any of the conjugated dienes or monovinyl aromatic compounds described can be employed. The ratio of conjugated diene or monovinyl aromatic compound additive employed preferably should be in the range of about 2 to 15 moles of polymerizable compound per mole of organolithium compound. The amount of multivinylaromatic compound employed preferably should be in the range of about 0.05 to 2 moles per mole of organomonolithium compound.
Exemplary multivinyl aromatic compounds include 1,2-divinylbenzene, 1,3-divinylbenzene, 1,4-divinylbenzene, 1,2,4-trivinylbenzene, 1,3-divinylnaphthalene, 1,8-divinylnaphthalene, 1,3,5-trivinylnaphthalene, 2,4-divinylbiphenyl, 3,5,4′-trivinylbiphenyl, m-diisopropenyl benzene, p-diisopropenyl benzene, 1,3-divinyl-4,5,8-tributylnaphthalene, and the like. Divinyl aromatic hydrocarbons containing up to 18 carbon atoms per molecule are preferred, particularly divinylbenzene as either the ortho, meta, or para isomer, and commercial divinylbenzene, which is a mixture of the three isomers, and other compounds such as the ethylstyrenes, also is quite satisfactory.
Other types of multifunctional initiators can be employed such as those prepared by contacting a sec- or tert-organomonolithium compound with 1,3-butadiene, at a ratio of about 2 to 4 moles of the organomonolithium compound per mole of the 1,3-butadiene, in the absence of added polar material in this instance, with the contacting preferably being conducted in an inert hydrocarbon diluent, though contacting without the diluent can be employed if desired.
Alternatively, specific organolithium compounds can be employed as initiators, if desired, in the preparation of polymers in accordance with the present invention. These can be represented by R(Li) x wherein R represents a hydrocarbyl radical containing from 1 to 20 carbon atoms, and wherein x is an integer of 1 to 4. Exemplary organolithium compounds are methyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-octyllithium, n-decyllithium, phenyllithium, 1-naphthyllithium, 4-butylphenyllithium, p-tolyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4-butylcyclohexyllithium, 4-cyclohexylbutyllithium, dilithiomethane, 1,4-dilithiobutane, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,4-dilithiocyclohexane, 1,4-dilithio-2-butane, 1,8-dilithio-3-decene, 1,2-dilithio-1,8-diphenyloctane, 1,4-dilithiobenzene, 1,4-dilithionaphthalene, 9,10-dilithioanthracene, 1,2-dilithio-1,2-diphenylethane, 1,3,5-trilithiopentane, 1,5,15-trilithioeicosane, 1,3,5-trilithiocyclohexane, 1,3,5,8-tetralithiodecane, 1,5,10,20-tetralithioeicosane, 1,2,4,6-tetralithiocyclohexane, 4,4′-dilithiobiphenyl, and the like.
The organoaluminum compounds that can be utilized typically have the structural formula:
in which R 1 is selected from the group consisting of alkyl groups (including cycloalkyl), aryl groups, alkaryl groups, arylalkyl groups, alkoxy groups, and hydrogen; R 2 and R 3 being selected from the group consisting of alkyl groups (including cycloalkyl), aryl groups, alkaryl groups, and arylalkyl groups. Some representative examples of organoaluminum compounds that can be utilized are diethyl aluminum hydride, di-n-propyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, diphenyl aluminum hydride, di-p-tolyl aluminum hydride, dibenzyl aluminum hydride, phenyl ethyl aluminum hydride, phenyl-n-propyl aluminum hydride, p-tolyl ethyl aluminum hydride, p-tolyl n-propyl aluminum hydride, p-tolyl isopropyl aluminum hydride, benzyl ethyl aluminum hydride, benzyl n-propyl aluminum hydride, and benzyl isopropyl aluminum hydride, diethylaluminum ethoxide, diisobutylaluminum ethoxide, dipropylaluminum methoxide, trimethyl aluminum, triethyl aluminum, tri-n-propyl aluminum, triisopropyl aluminum, tri-n-butyl aluminum, triisobutyl aluminum, tripentyl aluminum, trihexyl aluminum, tricyclohexyl aluminum, trioctyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, tribenzyl aluminum, ethyl diphenyl aluminum, ethyl di-p-tolyl aluminum, ethyl dibenzyl aluminum, diethyl phenyl aluminum, diethyl p-tolyl aluminum, diethyl benzyl aluminum and other triorganoaluminum compounds. The preferred organoaluminum compounds include triethyl aluminum (TEAL), tri-n-propyl aluminum, triisobutyl aluminum (TIBAL), trihexyl aluminum and diisobutyl aluminum hydride (DIBA-H).
The barium salts of cyclic alcohols that can be used can be mono-cyclic, bi-cyclic or tri-cyclic and can be aliphatic or aromatic. They can be substituted with 1 to 5 hydrocarbon moieties and can also optionally contain hetero-atoms. For instance, the barium salt of the cyclic alcohol can be a metal salt of a di-alkylated cyclohexanol, such as 2-isopropyl-5-methylcyclohexanol or 2-t-butyl-5-methylcyclohexanol. These barium salts are preferred because they are soluble in hexane. Barium salts of disubstituted cyclohexanol are highly preferred because they are soluble in hexane. Barium mentholate is the most highly preferred barium salt of a cyclic alcohol that can be employed in the practice of this invention. Barium salts of thymol can also be utilized. The barium salt of the cyclic alcohol can be prepared by reacting the cyclic alcohol directly with the barium or another barium source, such as barium hydride, in an aliphatic or aromatic solvent.
The lithium salts of cyclic alcohols that can be used can be used can be mono-cyclic, bi-cyclic or tri-cyclic and can be aliphatic or aromatic. They can be substituted with 1 to 5 hydrocarbon moieties and can also optionally contain hetero-atoms. For instance, the lithium salt of the cyclic alcohol can be a lithium salt of a di-alkylated cyclohexanol, such as 2-isopropyl-5-methylcyclohexanol or 2-t-butyl-5-methylcyclohexanol. These lithium salts are preferred because they are soluble in hexane. Lithium salts of disubstituted cyclohexanol are highly preferred because they are soluble in hexane. Lithium mentholate is the most highly preferred lithium salt of a cyclic alcohol that can be employed in the practice of this invention. Lithium salts of thymol can also be utilized. The lithium salt of the cyclic alcohol can be prepared by reacting the cyclic alcohol directly with the lithium or another lithium source, such as lithium hydride, in an aliphatic or aromatic solvent.
The molar ratio of the organoaluminum compound to the organolithium compound will be within the range of about 0.3:1 to about 8:1. It will preferably be within the range of about 0.5:1 to about 5:1 and will most preferably be within the range of about 1.2:1 to about 2:1. The molar ratio of the barium salt of the cyclic alcohol to the organolithium compound will be within the range of about 0.1:1 to salt of the cyclic alcohol to the organolithium compound will preferably be within the range of about 0.15:1 to about 1.2:1 and will most preferably be within the range of about 0.2:1 to about 0.6:1. The molar ratio of the lithium salt of the cyclic alcohol to the organolithium compound will be within the range of about 0.15:1 to about 4:1. The molar ratio of the lithium salt of the cyclic alcohol to the organolithium compound will preferably be within the range of about 0.25:1 to about 2.5:1 with ratios within the range of about 0.6:1 to about 1:1 being most preferred.
The polymerization temperature utilized can vary over a broad temperature range of from about 20° C. to about 120° C. In most cases, a temperature within the range of about 40° C. to about 100° C. will be utilized. It is typically most preferred for the polymerization temperature to be within the range of about 60° C. to about 90° C. Lower polymerization temperatures generally result in higher polymer melting points. However, the glass transition temperature of the trans-1,4-polybutadiene does not change as a function of polymerization temperature. The pressure used will normally be sufficient to maintain a substantially liquid phase under the conditions of the polymerization reaction.
The polymerization is conducted for a length of time sufficient to permit substantially complete polymerization of monomers. In other words, the polymerization is normally carried out until high conversions are attained. The polymerization can then be terminated using a standard technique. The polymerization can be terminated with a conventional noncoupling type of terminator, such as water, an acid, a lower alcohol, and the like or with a coupling agent. For instance, coupling agents can be used in order to improve the cold flow characteristics of the trans-1,4-polybutadiene rubber and rolling resistance of tires made therefrom. It also leads to better processability and other beneficial properties. A wide variety of compounds suitable for such purposes can be employed. Some representative examples of suitable coupling agents include: multivinylaromatic compounds, multiepoxides, multiisocyanates, multiimines, multialdehydes, multiketones, multihalides, multianhydrides, multiesters which are the esters of polyalcohols with monocarboxylic acids, and the diesters which are esters of monohydric alcohols with dicarboxylic acids, and the like.
After the copolymerization has been completed, the trans-1.4-polybutadiene can be recovered from the organic solvent. The trans-1,4-polybutadiene can be recovered from the organic solvent and residue by means such as decantation, filtration, centrification and the like. It is often desirable to precipitate the trans-1,4-polybutadiene from the organic solvent by the addition of lower alcohols containing from about 1 to about 4 carbon atoms to the polymer solution. Suitable lower alcohols for precipitation of the segmented polymer from the polymer cement include methanol, ethanol, isopropyl alcohol, normal-propyl alcohol and t-butyl alcohol. The utilization of lower alcohols to precipitate the trans-1,4-polybutadiene from the polymer cement also “kills” the living polymer by inactivating lithium end groups. After the trans-1,4-polybutadiene is recovered from the solution, steam stripping can be employed to reduce the level of volatile organic compounds in the segmented polymer.
This invention is illustrated by the following examples which are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. Unless specifically indicated otherwise, parts and percentages are given by weight.
EXAMPLE 1
In this experiment, 2000 g of a silica/amumina/molcular sieve dried premix containing 18.3 weight percent 1,3-butadiene was charged into a one-gallon (3.8 liters) reactor. Then, 6.6 milliliters (ml) of a 0.2 M solution of barium thymolate (BAT) in ethylbenzene, 3.4 ml of a 1.0 M solution of menthol in hexanes, 6.6 ml of a 1.02 M solution of n-butyllithium (n-BuLi) in hexanes and 6.2 ml of a 0.87 M solution of triethylaluminum (TEA) were added to the reactor. The molar ratio of BAT to menthol to n-BuLi to TEA was 1:2.5:5:4.
The polymerization was carried out at 90° C. for 3 hours. The GC analysis of the residual monomer contained in the polymerization mixture indicated that 93% monomer was consumed after the 3 hour polymerization time. The polymerization was continued for an additional 30 minutes and then, two ml of a 1 M ethanol solution in hexanes was added to shortstop the polymerization and polymer was removed from the reactor and stabilized with 1 phm of antioxidant. After evaporating hexanes, the resulting polymer was dried in a vaccum oven at 50° C.
The polybutdiene produced was determined to have a glass transition temperature (Tg) at −93° C. and a melting temperature (Tm) at 8.1° C. It was then determined to have a microstructure which contained 4 percent 1,2-polybutadiene units, 20 percent cis-1,4-polybutadiene units, and 76% trans-1,4-polybutadiene units. The Mooney viscosity (ML-4) at 100° C. for this polymer was determined to be 34.
EXAMPLE 2
The procedure described in Example 1 was utilized in this example except that the ratio of BAT to menthol to n-BuLi to TEA ratio was changed to 1:4:10:8. About 90% on monomer was consusmed in 90 minutes. The resulting polymer had a glass transition temperature of −95° C. and a melting point of 9.5° C. It was also determined to have a microstructure which contained 5% 1,2-polybutadiene units, 20% cis-1,4-polybutadiene units, and 75% trans-1,4-polybutadiene units.
EXAMPLE 3
The procedure described in Example 1 was utilized in this example except that the polymerization was carried out at 65° C. The resulting polymer had a glass transition temperature −95° and a melting point of 9.3° C. It was also determined to have a microstructure which contained 4% 1,2-polybutadiene units, 16% cis-1,4-polybutadiene units and 80% trans-1,4-polybutadiene units.
EXAMPLE 4
The procedure described in Example 1 was utilized in this example except that lithium t-butoxide was used in place of menthol. The resulting polymer had a glass transition temperature of −95° C. and a melting point of −7.6° C. It was also determined to have a microstructure which contained 6% 1,2-polybutadiene units, 24% cis-1,4-polybutadiene units, and 70% trans-1,4-polybutadiene units.
EXAMPLE 5
The procedure described in Example 1 was utilized in this example except that barium 2-ethylhexoxide was used in place of BAT. The resulting polymer had a glass transition temperature of −95° C. and a melting point of −24° C. It was also determined to have a microstructure which contained 7% 1,2-polybutadiene units, 29% cis-1,4-polybutadiene units, and 64% trans-1,4-polybutadiene units.
EXAMPLE 6
The produce described in Example 1 was utilized in this example except that barium tetrahydrofurfurlate was used in place of BAT. The resulting polymer had a glass transition temperature of −95° C. and a melting point of −10° C. It was also determined to have a microstructure which contained 6% 1,2-polybutadiene units, 24% cis-1,4-polybutadiene units, and 70% trans-1,4-polybutadiene units.
EXAMPLE 7
The procedure described in Example 1 was utilized in this example except that the polymerization was conducted at 65° C. and that menthol was not used as part of catalyst component. The resulting polymer had a glass transition temperature of −91° C. and a melting point of 11° C. It was also determined to have a microstructure which contained 5% 1,2-polybutadiene units, 19% cis-1,4-polybutadiene units, and 76% trans-1,4-polybutadiene units.
EXAMPLE 8
The procedure described in Example 1 was utilized in this example except that menthol was not used as part of catalyst component. The resulting polymer had a glass transition temperature of −95° C. and a melting point of −14° C. It was also determined to have a microstructure which contained 6% 1,2-polybutadiene units, 22% cis-1,4-polybutadiene units, and 72% trans-1,4-polybutadiene units.
EXAMPLE 9
The procedure described in Example 1 was utilized in this example except that menthol was not used as part of catalyst component with barium mentholate (BAM) was used in place of barium thymolate (BAT). The resulting polymer had a glass transition temperature of −95° C. and a melting point of −13° C. It was also determined to have a microstructure which contained 6% 1,2-polybutadiene units, 25% cis-1,4-polybutadiene units, and 69% trans-1,4-polybutadiene units.
EXAMPLE 10
The procedure described in Example 9 was utilized in this example except that polymerization was carried out at 75° C. The resulting polymer had a glass transition temperature of −94° C. and a melting point of 7.1° C. It was also determined to have a microstructure which contained 5% 1,2-polybutadiene units, 19% cis-1,4-polybutadiene units, and 76% trans-1,4-polybutadiene units. The Mooney viscosity of this polymer at 100° C. was determined to be 78.
EXAMPLE 11
The procedure described in Example 1 was utilized in this example except that dibutylmagnesium (Bu2Mg) was used instead of n-BuLi and barium mentholate (BAM) was used in place of barium thymolate (BAT). The ratio of BAM to Bu 2 Mg to t-BuOLi to TEA was 1:10:4:4. About 70% monomer conversion was achieved after 6 hours of polymerization time at 90° C. The resulting polymer has a glass transition temperature of −95° C. and a melting point of 8.1° C.
EXAMPLE 12
The procedure described in Example 7 was utilized in this example except that 1.5 times as much of the BAT was used with the ratio of BAT to n-BuLi to TEA ratio being 1:10:9. The resulting polymer has a glass transition temperature of −91° C. and a melting point of 44° C. It was also determined to have a microstructure which contained 3% 1,2-polybutadiene units, 13% cis-1,4-polybutadiene units, and 84% trans-1,4-polybutadiene units.
EXAMPLE 13
In this series of experiments copolymerization was carried out in a one-gallon glass bowl reactor, under a blanket of nitrogen, equipped with a mechanical stirrer. Temperature was controlled with cooling water and low pressure steam. Both 1,3-butadiene and styrene premixes contained approximately 20% monomer dissolved in hexane. The reactor was charged with 10% styrene in hexane and 90% 1,3-butadiene in hexane to synthesize the appropriate polymers. A reactor used was of sufficient size to hold up to approximately 2000 grams total of both premixes. After the reactor was charged, the contents were then heated. While heating, the catalyst system was added. Within minutes of addition, the reactor temperature was 100° C. The catalyst system for this polymer consisted of an alkylated barium thymolate (BAT), trioctyl aluminum (TOA), and n-butylithium (n-BuLi). The molar ratio of BAT to TOA was 1:4.
The addition of this catalyst proved to be crictical for successful polymerization. The alkylated BAT and TOA solution was prepared by added the appropriate amount of TOA to BAT and with heating for 30 minutes at 70° C. To initiate polymerization, the alkylated BAT/TOA solution was added to a clean bottle and the correct amount of n-BuLi (in a ratio of 3 n-BuLi to 1 BAT) was added to this bottle. In cases where amines were used they were employed in the catalyst system at a ratio of 1:1 to the BAT. Any amines added were added to the catalyst right after the alkylated BAT/TOA solution but before the n-BuLi. The final solution had a ratio of 1/4/3/1 BAT/TOA/n-BuLi/amine (if used). This final solution was allowed to react for several minutes, and then it was injected as the initiator. Samples were taken over the course of the reaction to determine monomer conversion. All reactions were short-stopped with denatured ethanol, and 2,6-ditertbutylphenol was added to the polymer cement. The polymer was then dried for several days in a hot oven to make sure all solvent had evaporated. The following table summarizes the data for this system:
Target
Sample
Amine
Tg onset
Tm
Mn
Mw
Mn
10/90
none
−89.0° C.
−21.2° C.
128K
252K
100K
SBR
10/90
Pyrro-
−87.9° C.
−20.9° C.
54K
98K
100K
SBR
lidine
20/80
12/1 ratio
−87.6° C.
−25.3° C.
193K
329K
200K
SBR
of
TMEDA
to BAT
added
after 4 hrs.
20/80
none
−85.4° C.
−19.1° C.
87K
151K
200K
SBR
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims. | The process and catalyst system of this invention can be utilized to synthesize polybutadiene rubber having a high trans content and a low melting point by solution polymerization. The trans-polybutadiene rubber made by the process of this invention can be utilized in tire tread rubbers that exhibit outstanding wear characteristics. More importantly, the trans-polybutadiene rubber of this invention can be easily processed because of its low level of crystallinity. In fact, the trans-polybutadiene made by the process of this invention does not need to be heated in a “hot-house” before being used in making rubber compounds. The process and catalyst system of this invention can also be used in the synthesis of trans-styrene-butadiene rubber (SBR). This invention more specifically reveals a process for synthesizing trans-polybutadiene rubber which comprises polymerizing 1,3-butadiene in an organic solvent in the presence of a catalyst system which comprises (a) an organolithium compound, (b) a barium compound selected from the group consisting of (i) barium salts of cyclic alcohols, such as barium mentholate, and (ii) barium thymol, and (c) an organoaluminum compound. | 2 |
BACKGROUND AND FIELD
This invention relates to railway systems and more particularly relates to a novel and improved rail adaptable for use in electric transit systems of metropolitan areas.
It has been proposed in the past to utilize resilient pads beneath the lower flanges of railroad rails as well as railroad ties for cushioning the rails and insulating them electrically from the ties and from other underlying structures. In many cases, clamps are employed on opposite sides of the lower flange which are in turn anchored into the railroad ties or rail bed. Also, in some cases an adhesive is interposed between the pad and the rail.
Different considerations are involved in the construction and installation of rails for urban transit systems which are typically employed as a part of electrical transit systems and must be mounted in asphalt or concrete roadways. Instead of a gravel or dirt roadbed the rails are embedded in spaced parallel channels formed out of the existing roadway such that the top or head of the rail projects slightly above the upper end of the channel or roadway surface. In the past, rubber boots have been loosely disposed in surrounding relation to the bottom flange of the rail and typically held in place with the use of clamps extending along the entire length of the rail system. This approach has been unsatisfactory particularly from the standpoint of complete vibration and sound-proofing as well as providing the necessary resistance to corrosion resulting from stray electrical current. In stray current corrosion, an electrical current flowing in the environment adjacent to a structure causes one area on the structure to act as an anode and another area to act as a cathode. For example, in an electric railway, a pipeline or other structure may become a low resistance path for the current returning from the train to the power source. Whenever the pipeline is caused to be more positive by the stray current, corrosion occurs at a higher rate but can be avoided by proper insulation of the rail.
Over extended periods of time, rail systems of the type described have been wholly inadequate to achieve the necessary vibration and sound-proofing and to avoid corrosion from stray or leakage current of the types described.
SUMMARY
It is therefore an object to provide for a novel and improved insulated rail system and method of making same.
It is another object to provide for a novel and improved rail system, which is rugged, durable and comprised of a minimum number of parts.
It is a further object to provide for a novel and improved insulated rail system which is vibration and sound-proof as well as capable of substantially eliminating any corrosion resulting from stray or leakage current and which enables greatly simplified installation over extended distances.
It is an additional object to provide for a novel and improved method of manufacturing insulated rail in a minimum number of steps and which results in the formation of a rubber clad rail assembly.
According to one aspect, a transportation rail extends along a rail bed, the rail having a bottom flange, top flange along which a train or other vehicle is advanced, and a vertical web portion interconnecting the bottom and top flanges and wherein the improvement comprises a rail cover composed of a dielectric vulcanizable material including a lower seat portion surrounding and vulcanized to the bottom flange and upper side portions covering and vulcanized to opposite sides of the web portion up to the top flange, and wherein said cover acts as a barrier against chemical attack and electrolytic corrosion of said rail. In another aspect, a rigid skid plate surrounds the sides and underside of the bottom flange prior to placement in the guideway or channel formed in the roadway when used for electric trains, and lateral extensions of the sides of the cover may cushion the rail against lateral thrusting or shifting.
A method of manufacturing a rail section of the type described comprises the steps of positioning a sheet of a flexible dielectric material in surrounding relation to the base flange and opposite sides of the web portion along the substantial length of the rail section, and vulcanizing the sheet under heat and pressure to the rail section. If a skid plate is employed, the method further comprises the additional step of positioning the skid plate in surrounding relation to an underside and opposite sides of the bottom flange and vulcanizing the cover sheet and skid plate together with the rail. The cover sheet may be extruded into the desired configuration prior to vulcanization and given additional thickness along opposite sides of the web portion, or separate strips of a flexible dielectric material may be adhered to the sides of the cover sheet for additional cushioning and sound-proofing.
The above and other objects, advantages and features of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of preferred and modified forms of the present invention when taken together with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of one embodiment of rail;
FIG. 2 is a cross-sectional view of another embodiment of rail;
FIG. 3 is a cross-sectional view illustrating one step in the process of manufacturing the embodiment shown in FIG. 2 ;
FIG. 4 is a cross-sectional view of another step involved in the process of manufacturing the embodiment shown in FIG. 2 ; and
FIG. 5 is a side elevational view illustrating welded rail sections covered by a patch as a part of the insulated rail system.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring in more detail to the drawings, FIG. 1 illustrates a composite rail, which is made up of a standard rail 10 and a rail cover 12 . The rail 10 is of generally I-shaped cross-sectional configuration having a bottom flange 14 provided with a flat undersurface 15 and opposite sides 16 together with sloped upper surfaces 17 which merge into a vertical web portion 18 . A top flange 20 has a slightly convex top surface 22 and opposite sides 24 together with sloped undersurfaces 26 which merge into the upper end of the vertical web portion 18 . In accordance with conventional practice, the rail may be composed of various grades of steel or aluminum depending upon load requirements. As a setting for the one embodiment, the rail is composed of steel and is designed with a relatively broad base flange 14 in comparison to the width of the top flange 20 .
In the one embodiment, the rail is adapted for use as a railroad track for the prevention of corrosion due to stray current leakage in electrified rail transit systems operating in metropolitan areas. To this end, the rail 10 is clad with a tough, durable elastomeric sheet or cover 30 which is vulcanized to the rail and specifically in such a way as to cover the entire base flange 14 , opposite sides of the web portion 18 and undersides 26 of the top flange 20 . One side 28 of the cover is of progressively increased thickness along the underside of the top flange and terminates in a lobe 28 ′ along one side of the top flange; whereas, the opposite side 29 is of progressively increased thickness along the underside of the top flange and terminates in a tapered end 29 ′ beneath the side of the top flange so as to leave clearance along that side for the wheel flange of each of the train wheels.
FIG. 2 illustrates another embodiment in which a skid plate 32 of generally channel-shaped cross-sectional configuration is mounted on the rail directly to the rail cover 30 extending along the underside 15 and opposite sides 16 of the base flange 14 . Thus, the skid plate 32 includes a substantially flat base 34 and opposite sides 36 which are bent into generally concavo-convex configuration in tightly surrounding relation to the opposite sides 16 and terminate in upper edges 38 which overlie outer ends of the sloped upper surfaces 17 .
The rail cover 30 is vulcanized by subjecting to high pressure and super-heated steam so as to bond the cover both to the steel rail 10 and skid plate 32 . This procedure creates an impermeable barrier which protects the surrounding environment from the costly and often hazardous ravages of electrolytic corrosion. In the form of FIG. 2 , the sides of the rail cover are of uniform thickness and terminate along the undersides of the top flange.
FIGS. 3 and 4 illustrate the steps followed in the fabrication of one embodiment of rail system as hereinbefore described. The rail 10 is customarily cut into 40 ′ long sections, and a bonding agent is applied to the bottom flange 14 and web portion 18 as well as the undersides of the top flange 20 throughout the entire length of the section. The sheets of rubber making up the rail cover 20 are cut into shorter lengths than the rail section so as to leave several inches at each end of the rail section exposed for welding the section ends as hereinafter described. Similarly, the skid plate 32 is formed into sections slightly shorter in length than the rail sections 10 so as not to interfere with the welding operation. At the manufacturing site, each skid plate section 34 is positioned in a steel channel jig J and, as illustrated in FIG. 3 , each length of the rail cover 30 is placed in the skid plate 32 with opposite sides of the cover 30 extending upwardly beyond opposite sides 36 of the skid plate 34 . The upper ends 38 of the opposite sides 36 are bent or crimped over the outer ends of the rail. Again, a suitable bonding agent is placed along the inner contacting surfaces of the rail 10 as a preliminary to applying the free sides of the cover 30 into contacting relation to the upper surfaces 17 and opposite sides of the web section 18 into the configuration illustrated in FIG. 3 , although it will be appreciated that the bonding agent may be applied to the entire inner surface of the entire cover 30 rather than the rail 10 prior to placement beneath the rail. A suitable crimping tool is then employed to crimp the upper ends 38 of the skid plate 32 over the outer ends of the upper surfaces 17 . In another preferred form, the rubber cover 30 may be extruded into the desired rail-shaped configuration as illustrated into FIG. 2 prior to the vulcanization step now to be described.
Each rail section is typically on the order of 40 ′ in length and may be vulcanized in a suitable press to subject it to the desired high pressure and super-heated steam level over a predetermined time interval depending to a great extent on the thickness of the cover 30 . For the purpose of illustration but not limitation, the rail cover 30 may be on the order of ¼″ thick for a rail which is on the order of 8″ high. The composition of the rail cover 30 is totally impervious to moisture penetration and is highly resistant to harsh chemicals, such as, street de-icers, other acids or salts and automotive exhaust gases. It can withstand severe impact and abrasion and easily endures the usual rough handling and hauling from the plant to the rail site.
The skid plate 32 is useful as a means of protecting the rail cover when installed in the rail bed. For example, in an electric transit system, each rail of the railroad track is placed in a separate channel or shallow recess formed in the pavement of the roadway, as illustrated in FIGS. 1 and 2 . As best seen from FIG. 5 , typically the ends of the rail section are welded together as at 50 and the weld seams are cleaned, covered, sealed and insulated by on-site application of a sealant. If it should be necessary to leave a gap between the end of the cover 30 and the end of rail section 10 , a heat-cured patch 52 is applied to the exposed ends of the rail sections 10 between the terminal edges of the rail covers 30 of adjoining rail sections. Preferably, the patch 52 is molded or extruded into the same cross-sectional configuration as the rail cover 30 and cured at the factory site. Upon completion of the welding operation, the patch 52 is slipped over the rail and chemically cured or heated with the opposite edges of the patch butt-welded or cured together with the ends of the rail covers 30 as designated at 54 .
FIG. 5 illustrates the rail sections welded together and patched as described without the use of skid plates 32 . In other words, the rail 10 corresponds to that shown in FIG. 1 and may be installed in the rail channels C without adding the skid plates 32 . Whether employed with or without the skid plates 32 , a suitable filler as designated at F in FIGS. 1 and 2 is illustrated as being placed around the rails after they have been laid and welded in the channels. In either preferred form as shown in FIG. 1 or 2 , the filler may be a concrete filler although it will be apparent that other types of commercial fillers may be employed, taking care to leave a gap G between the filler and one side 24 of the top flange 20 so as not to interfere with the train wheel.
From the foregoing, the rail cover 30 is characterized in particular by acting as an insulator to prevent electrolysis and as a corrosion-proof barrier to prevent electro-chemical attack, such as, oxidation of the steel or by exposure to corrosive chemicals, such as, street de-icers or by automobile exhaust and other acids. Thus, it is highly important to vulcanize the rail cover 30 to the entire rail surfaces other than the wear surfaces so as to act as an effective barrier against chemical attack as well as electrolytic corrosion.
It is therefore to be understood that while plural embodiments are herein set forth and described, the above and other modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and reasonable equivalents thereof. | A rail cover and support for mounting and insulating the rails of an electric transit system in which the rail cover is vulcanized both to the rail and outer skid support at the manufacturing site prior to delivery to the field and a rail cover completely surrounds both the base flange and web portion of each rail and terminates along the undersides of the top flange. In one form, the upper free ends of the rail cover are increased in thickness to form bumpers along opposite sides of the rail to cushion it against undue shifting or vibration. In fabricating the rail, a sheet dielectric material is vulcanized to the rail with or without a skid plate. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to telecommunications technology and especially to the mechanisms that support group communication.
In mobile telephone networks used by fire and rescue authorities and the police or companies, group communication between authorities performing official tasks is among the most essential telecommunications traffic in the network. Such networks are often called private or professional mobile radio (PMR) networks.
TETRA (TErrestrial Trunked RAdio) is a standard for digital PMR systems defined by ETSI (European Telecommunications Standards Institute). Group communication can, in turn, be defined as traffic, in which a call or some other data transmission or telecommunications action can be established simultaneously for a predefined user group.
Usually group traffic is implemented as ‘push-to-talk, release-to-listen’ traffic, in which a radio channel is reserved while the push-to-talk switch is pressed and possibly for a time after the switch is released, i.e. a guard period.
In a prior-art group call management mechanism, a centralized control centre to which all speech item requests are transmitted is appointed for the group. The control centre maintains a speech item queue and reserves resources from other centres defined as belonging to the area of the group. Advanced centralized control centres are also able to keep track of the locations of the members of a group in the area of the group and to reserve resources from the base stations where the group members are located at a specific moment.
In fault situations of a communication network, a situation may arise in which group call management from a centralized point is not possible and group calls are prevented at least partly. This may be due to an earthquake or sabotage that has damaged the centre in the centralized point.
In fault situations of a communication network as well as in catastrophes, it is essential that group traffic between authorities performing the same task be secured.
BRIEF DESCRIPTION OF THE INVENTION
It is thus an object of the invention to secure group traffic even in fault situations, in which group call management from a centralized point is not possible. A further object of the invention is to provide a method that assigns the speech items of a group call and handles their queue in a distributed manner without a centralized control element. These objects and other objects of the invention are achieved by a method and centre which are characterized by what is disclosed in the independent claims. Preferred embodiments of the invention are disclosed in the dependent claims.
In the present invention, the control of group traffic is distributed in such a manner that when a subscriber requests a speech item in a group call, the network element serving the subscriber, for instance a switching centre, transmits the request to all other controlling network elements having group members. If there are no competing, earlier speech item requests or simultaneous, higher-priority requests in the other network elements, they accept the request. The serving network element grants the speech item only if its own speech item request situation and the other controlling network elements allow the speech item.
The invention provides a network procedure that makes unnecessary a critical centralized group call management element that would primarily handle the distribution of speech items and the maintenance of a speech item queue; the telecommunications network thus becomes more fault-tolerant. In addition, the dimensioning and planning of the telecommunications network becomes easier.
BRIEF DESCRIPTION OF THE FIGURES
The invention will now be described in greater detail by means of preferred embodiments and with reference to the attached drawings, in which
FIG. 1 illustrates a network architecture and the storing of subscriber and location information,
FIG. 2 illustrates the updating of the group information of a subscriber,
FIG. 3 illustrates a group call of a subscriber,
FIG. 4 illustrates the ending of a speech item,
FIG. 5 illustrates queuing for a speech item,
FIG. 6 illustrates the granting of a speech item from the queue,
FIG. 7 illustrates a collision of speech item requests,
FIG. 8 illustrates a pre-emptive speech item of a subscriber, and
FIG. 9 illustrates recovery from a fault situation.
DETAILED DESCRIPTION OF THE INVENTION
The invention will be described using a PMR network and more specifically a TETRA network as an example. A detailed structure and operation of the TETRA network are not essential for the invention. It should be appreciated that the invention can be applied to any fixed and/or mobile communication and data network that supports the group call mechanism.
In this context, the term ‘group’ refers to any logical group of three or more users that intend to participate in one and the same group call or group traffic. In this context, group traffic also covers for instance message services, in which the same data message is transmitted to all members of a group. The groups are created logically, in other words, specific group call information maintained on the network side associates a specific user with a specific group call. This association can easily be changed or removed by the user, operator or some other instance. One user can be a member of (and even simultaneously active in) more than one group traffic group. Typically, the members of a group belong to one organization, such as the police, fire department, or a private company. One organization typically has several group traffic groups.
The following describes in a simplified manner examples of different group call cases by means of FIGS. 1 to 9 . Even though the examples are shown implemented by IP technology, a group call can also be implemented using other signalling systems and data transmission protocols.
FIG. 1 shows the elements required for storing subscriber and location information in a TETRA architecture. The subscriber database is in a home location register HLR. The subscriber database maintains permanent and variable information related to the subscribers. The information typically comprises the call and reception rights of a subscriber and information on supplementary services activated for the subscriber and the location information of the subscriber. Depending on the size of the network, the number of subscribers and service types in it, there may be several HLRs that distribute the load on the basis of the number of subscribers, service types or any other distribution method optimising the management of information. Changes in the subscriber information, such as changes in the location of the mobile station, are made primarily to the home location register through mobile switching centres DXT_ 1 . . . DXT_M (DXT, Digital Exchange for TETRA).
In addition to HLR elements, the network can also have one or more VLR (Visited Location Register) elements. A switching centre and VLR can also be combined into one element, a visited switching centre, which is any other centre than the home switching centre of the mobile station and controls the traffic area in which the mobile station is. In the TETRA system, VLR can be in the switching centre DXT. The base station of the system TBS_ 1 (TBS, TETRA Base Station) can be connected to the switching centre DTX_ 1 as shown in FIG. 1 .
In addition to the above-mentioned elements, the mobile network may comprise an address server DHCP (Dynamic Host Configuration Protocol) that allocates IP (Internet Protocol) addresses to subscribers on the request of the switching centres. The location updates of the subscribers are made to the address server DHCP. The network can also have a name server DNS (Domain Name Server) that allows a terminal, for instance a mobile station MS, to be called by several names even though the IP address changes when the location of the subscriber changes. The name server DNS makes name-address changes. The name server DNS and the address server DCHP can be combined into one element.
All elements described above can preferably be connected to each other with a packet-switched network that supports IP and IP-packet routing based on the IP address and is herein generally called an IP network. The IP network can be the operator's intranet, local area network LAN or even the Internet.
An IP system refers to an Internet-type communication network in which a message is transmitted from the sender to the recipient by using IP. In such a network, IP is the actual network protocol that routes the addressed IP message through routers IP-ROUTER utilizing IP technology from a source station to a destination station (the figures show only one router; in practice, there may be several, in which case, they are referred to as a router cloud). A specific advantage of the TCP/IP (Transmission Control Protocol/Internet Protocol) protocol, which is the data transmission protocol of the Internet, is its independence of different hardware and software architectures.
The transmission of data in Internet networks is packet-switched data transmission. In it, data is transmitted in packets, each of which contains the source and destination addresses in addition to the payload. Each packet is routed through the packet-switched network independently on the basis of said address information. Thus, data packets related to one communication can propagate along different routes and with different delays from the source to the destination depending on the load of the network.
However, it should be noted that the presented architecture is only an example and that the architecture is different for packet data solutions in the TETRA system, for instance. Different configurations exist for instance for connecting the switching centre DXT of the TETRA system to the telecommunications network of the IP system. In one configuration, each DXT element can have its own direct “exit” through an adjacent router to transmit IP packets on from the TETRA network to the Internet and vice versa. In this context, a router can refer to a device and/or software in the node, network station, of the telecommunications network that can direct data transmitted in the network to another, possibly different network on the basis of the address.
In another configuration, only one or a few of the DXT units, which can be called gateway DXTs, are connected to an Internet router and the rest of the DXT elements are connected to the Internet through these gateway DXT elements. Each switching centre DXT can form its own IP sub-network that has its own local IP address space. Correspondingly, an IP sub-network can comprise two or more switching centres DXT that thus have a common local address space. An IP packet that has an IP address belonging to the local address space of the IP sub-network is routed to the sub-network in question.
FIG. 2 illustrates how the group information of a subscriber is updated. The group information refers to the membership information of the group, for instance. The group information can be updated for instance when the subscriber registers into the network as a user of groups, when the subscriber has a set of groups available to it, but does not use them simultaneously, or when the subscriber stops using a certain group. In step 1 , the subscriber MS_ 1 notifies the switching centre DXT_C of his intent to join a group (group attach). The switching centre then checks the right of the subscriber to use the group. If the subscriber has the right to use the group and join it, the switching centre sends information on this to the router ROUTER in step 2 . The router replies in step 3 by using a standard Internet protocol, for instance.
Thus, when a subscriber is accepted as a user of the group, the switching centre communicates to the router that the IP address of the individual TETRA subscriber identity (ITSI) of the subscriber is a user of the group multicast address. This can be done using for instance an Internet group management protocol IGMP, which is a protocol that an IP host uses for instance to report the members of its multicast group to the adjacent multicast router. Finally in step 4 , the router sends an acknowledgement to the switching centre and the switching centre sends an acknowledgement to the subscriber by using a standard TETRA protocol, for instance.
The above-mentioned facilities can also be used when detaching from a group (group detach) or changing scanning (scanning). Changing scanning refers to the possibility of the subscriber to select for instance a certain call from several calls, or a feature, in which when listening in on several groups simultaneously, it is possible to stop listening in to other groups even though a call is started in them.
The membership of a subscriber in a multicast address is cancelled when the last member of the group detaches from the group in the switching centre.
FIG. 3 shows an example of the establishment of a group call. In step 1 , the subscriber MS_ 1 requests a group call. The switching centre DXT_C transmits the request to other switching centres DXT_A, DXT_B serving the group by means of the IP multicast address in step 2 . The switching centre DXT_C then transmits the request to the IP multicast address of the group and the router transmits the request for a group call on to the other switching centres serving the group members. In step 3 , the other switching centres DXT_A, DXT_B acknowledge the request through the router of the IP network to the switching centre DXT_C, because there are no other speech item requests. After receiving the acknowledgements, DXT_C gives the speech item to the subscriber in step 5 and the subscriber MS_ 1 can start speaking.
As shown in FIG. 3 , when the subscriber requests a speech item in a group call, the switching centre transmits the request to all switching centres that have members of the group. The request may contain information on the priority of the subscriber and a time stamp indicating the time of the request, if these are available.
If the other switching centres have no competing speech item requests made earlier or simultaneously made requests having a higher priority, the centres acknowledge the request to the switching centre of the requesting subscriber. After receiving the acknowledgements, the subscriber is granted the speech item and he can start speaking.
If there is a competing request in one of the switching centres, the requests are ordered by the priority of the requesting subscriber or the request time. If a competing request overrides a request from another switching centre, the acknowledgement contains information on this and lists the requesting subscribers in order of speech items.
If there are speech item requests in the other switching centres, too, a procedure of the type described above is initiated for each speech item request. The switching centre's version of the current speech item queue is added to the request to keep it same in all switching centres.
A distributed speech item distribution of the invention and its preferred embodiments means that instead of using one centralized switching centre, one or more multicast routers are used and that all switching centres that have participating subscribers know at least who is speaking and who is or are in queue.
According to a preferred embodiment of the invention, the participating switching centres DXT_A, DXT_B can transmit a positive acknowledgement, i.e. acknowledgement on granting the speech item, to the switching centre DXT_C, even though such an acknowledgement is not necessary. Positive acknowledgements provide the advantage, however, that they make the speech item distribution protocol of a group call faster. If no positive acknowledgements are used, group call establishment can only be continued when it is certain that all centres would have had time to transmit a negative acknowledgement even during congestion.
In addition to this, acknowledgements provide symmetry to the protocol. This means that even though a positive acknowledgement granting the speech item is not necessary, it can be provided and thus a possible insecurity caused by the conventional positive acknowledgement, silence, can be reduced. A positive acknowledgement can be left out for instance in a situation, in which a group has several subscribers and everyone gives a positive acknowledgement, in which case the signalling of several positive acknowledgements taxes the network significantly. The fact, whether or not the switching centre DXT_C (or the router of the signalling network, for instance) knows the other switching centres participating in the call, also has the same effect.
FIG. 4 shows how a speech item of a group call is ended. In step 1 , the subscriber ends the speech item by releasing the tangent, for instance. Alternatively, the switching centre DXT_C may notice that the subscriber has disappeared from the network, i.e. moved out of range or exceeded the maximum time for a speech item set in the switching centres. In step 2 , the switching centre DXT_C transmits ending information to the other centres DXT_A, DXT_B serving the group by using the IP multicast address, for instance. The other switching centres acknowledge the ending in step 3 . The switching centre DXT_C can acknowledge the end of the speech item to the subscriber in step 4 , if necessary.
The acknowledgements from the other switching centres DXT_A, DXT_B ending the speech item in step 3 (and in the steps of the following figures) are not necessary for the protocol, but they provide symmetry to the protocol as described above.
FIG. 5 illustrates an example of queuing for a speech item. In step 1 , the subscriber MS_ 1 requests a speech item, while another subscriber is already speaking in the same speech group. In step 2 , the switching centre DXT_C transmits a queue request to the other switching centres DXT_A, DXT_B serving the group through the router ROUTER by using the IP multicast address, for instance. The other centres add the subscriber to the speech item queue and acknowledge the queue request in step 3 . After receiving the acknowledgements, the switching centre DXT_C informs the subscriber MS_ 1 in step 4 that he is in the speech item queue.
If the subscriber indicates that he will stop queuing for the speech item before obtaining it, the procedure of FIG. 4 can be used.
FIG. 6 illustrates an example of the granting of a speech item from the queue. In step 1 , the subscriber ends the speech item for instance by signalling or by disappearing from the network. Alternatively, the switching centre DXT_C may notice that the subscriber MS_ 1 has exceeded the allowed time. In step 2 , the switching centre DXT_C transmits the ending information to the other switching centres serving the group by using the IP multicast address, for instance. The router forwards the information to the other centres serving the members of the group. The other centres acknowledge the ending in step 3 . The switching centre DXT_C can acknowledge the end of the speech item to the subscriber in step 4 , if necessary.
The subscriber MS_ 4 of the switching centre DXT_A is first in the speech item queue. The centre DXT_A requests a speech item for its subscriber as shown in FIG. 3 . If the speech item is granted to the subscriber, information on this is transmitted to the subscriber MS_ 4 in step 5 .
If the other switching centres have subscribers in the speech item queue, they can monitor the ending of the previous speech item and when the switching centre DXT_A starts to process the speech item queue. If the centre DXT_A does not transmit a speech item request within a given time, the next centre will send a request for its subscriber and so on.
FIG. 7 illustrates a collision of speech item requests, detection of the collision and recovery from it. In step 1 , the subscriber MS_ 1 requests a speech item in the switching centre DXT_C. At essentially the same time, a second subscriber MS_ 4 requests a speech item in the switching centre DXT_A. In steps 2 and 3 , both the centre DXT_C and the centre DXT_A transmit the request to the other switching centres serving the group (DXT_B, DXT_C to the subscriber MS_ 4 and DXT_A, DXT_B to the subscriber MS_ 1 ) by using the IP multicast address, for instance.
In step 4 , the switching centre DXT_A acknowledges the request to the centre DXT_C, in which the subscribers can be in the order of priority. Similarly in step 5 , the centre DXT_C acknowledges the request to the centre DXT_A, in which the subscribers can be in the order of priority. The acknowledgement can contain the priority order deduced by the centre. In the end, both centres must have the same priority order so that the establishment of the speech item can be continued in a collision situation. The order can be determined in several different ways, for instance on the basis of pre-set subscriber-specific priorities, time stamps or subscriber identifiers.
The participating switching centre DXT_B can also acknowledge the requests to the centres DXT_C and DXT_A for the above-mentioned reasons of symmetry.
Finally, the switching centre DXT_C grants the subscriber MS_ 1 a speech item, because the subscriber has a higher priority. In step 8 , the subscriber MS_ 1 begins to speak. The centre DXT_A indicates in step 9 to the subscriber MS_ 4 that he is in queue for the speech item.
In a digital telecommunications system, in the case of one switching centre, centralized control, speech item requests automatically have an arrival order. The order is not determined according to the requests made by the subscribers, but according to the order they arrive at the processing queue of the centralized call control. This is due to the fact that, in practice, transmission delays of the phones of different users, which are located in different parts of the network, can be of different length. In addition, the transmission delays can vary between calls, and the order of events seen by the centralized call control is not necessarily the same as the actual call request order of the users.
In a distributed model, the situation is more complex, because the order of the call requests is determined in several different network elements and due to the transmission delays, the elements see a different order for the same events.
A same kind of problem occurs in Ethernet-type local area networks: two devices in different parts of the network start to transmit at the same time to the network that to them seems empty, but due to transmission delays, the result is a collision of the transmissions and consequently, disappearance of messages.
For the solution of the problem it is important that all parties detect the collision and continue operation by using a method that prevents the same collision from repeating endlessly.
In the cases according to the invention and its preferred embodiments, all parties can detect a collision, when several switching centres transmit consecutively a call initiation request. Normally, there would be only one request and notifications from the other switching centres on speech item requests in queue.
When a collision takes place, the simplest recovery/continuation algorithm is to reject all essentially simultaneous requests and repeat the transmission with better luck after some time. This is how for instance the Ethernet protocol works.
According to the invention and its preferred embodiments, it would be possible to send negative acknowledgements to the mobile stations with a release reason of ‘switching centre overload’, for instance, which makes the users try to call again after a time—and probably at sufficiently differing times to prevent a new collision. However, in groups of many subscribers this may lead to too big a decrease in the service level, for instance in the case of the so-called stadium effect, in which all group members see the same event and immediately press the tangent to report what has happened. In other words, to achieve a sufficient service level in an official segment in particular, it must be possible to decide who receives the first speech item.
The speech item requests can be ordered primarily on the basis of exact time stamps, for instance, and secondarily according to some other criterion, such as priority, if necessary. However, if the system uses priorities to determine the order of the requests in the queue, it is logical to forget the order of events and also use the priorities in connection with call initiation to select the first speaker (contrary to what is done in a centralized system).
In addition, in the system of the invention, it is extremely important due to the nature of the service to initiate the call in all situations as quickly as possible. In other words, the algorithm is optimal, if it does not require extra message exchange between elements before the speech item is granted. In the system of the invention, each element uses the same algorithm for arranging the call requests. Each switching centre thus ends up with the same solution without message exchange.
Since one group can only have one speaker, the speech item should not be granted too quickly in case of collisions so that the speech item need not be cancelled. An end-user typically finds a pre-emptive cancelling of a speech item very annoying. Therefore, before granting the speech item, the system should wait for the time that elapses when transmitting a speech item request from the other switching centres of the network to this one. After this, collision is highly unlikely and can only be caused by delays from other faults in the network.
The waiting time can be set to a half of RTT (Round Trip Time), i.e. the time that an electronic signal takes when it propagates from a first end of a transmission medium to the second end and back. In a centralized system, the speech item can be granted only after the centralized element permits it, i.e. after RTT.
If transmission delays vary a lot, the most sensible solution is to bind the granting of the speech item to acknowledgements arriving from the other switching centres so as not to delay the call establishment unnecessarily. In practice, the delay variations of a correctly dimensioned transmission network between switching centres are small in comparison with the delays caused by a time-division radio network. In a TETRA system, for instance, a base station TBS can transmit to mobile stations 2 to 0.2 messages once in 56 milliseconds, so messages may easily remain in queue at the base station for hundreds of milliseconds. This is why in a system of the invention, when two or more subscribers request a speech item at the same time, it must be given to only one subscriber. The requests of the rest of the subscribers are arranged in a speech item queue.
FIG. 8 illustrates a pre-emptive speech item of a subscriber, which is a supplementary service enabling the subscriber to have pre-eminence for access to network resources in a TETRA system during congestion, for instance. In such a case, the calls of other subscribers can be inhibited. During a pre-emptive call, the system can immediately interrupt an ongoing transmission and give the transmission right to the calling party that requests pre-emptive transmission.
In step 1 of FIG. 8 , the subscriber MS_ 1 requests a pre-emptive speech item while another subscriber MS_ 4 is speaking in the same speech group. In step 2 , the switching centre DXT_C then transmits the pre-emptive request to the other switching centres serving the group by using the IP multicast address, for instance. The other centres DXT_A, DXT_B acknowledge the request in step 3 . After receiving the acknowledgements, the switching centre DXT_C notifies the subscriber in step 5 that the speech item has been granted to him. The switching centre DXT_A cancels the speech item of the subscriber MS_ 4 in step 6 .
FIG. 9 illustrates recovery from a fault situation. A fault situation may arise for instance when two subscribers speak at the same time. Such a situation may occur, if the acknowledgements do not arrive at the switching centres.
First, in step 1 , two subscribers MS_ 1 and MS_ 4 speak in the group at the same time without knowing of each other. The switching centres DXT_A and DXT_C notice that two subscribers have been given a speech item and speak at the same time. In step 2 , the switching centre DXT_C then requests a pre-emptive speech item for its higher-priority subscriber MS_ 1 by using the IP multicast address, for instance. The other centres DXT_A, DXT_B acknowledge the request in step 3 . The centre DXT_A cancels the speech item of its subscriber in step 5 . The subscriber MS_ 1 of the centre DXT_C can continue to speak. Alternatively, the centre DXT_A moves its subscriber to the speech item queue by generating a request according to FIG. 5 .
In the group call management mechanism according to prior art, a centralized control centre is named for a group and all speech item requests are sent there. The control centre maintains a speech item queue and reserves resources from other centres defined as belonging to the area of the group. Advanced centralized controls are also able to keep track of the locations of the group members within the area of the group and to reserve resources from only the base stations where the group members are located.
In a situation, where centralized speech item control malfunctions, the centre requesting a speech item assumes management of the speech item queue during the call in question. If requests collide, the requests are rejected and the users of the phones must press the tangent again.
The above describes as the invention a distributed group call control, speech item distribution, divided between the participating centres. It makes unnecessary the centralized element that would otherwise take care of speech item distribution and maintenance of the speech item queue. The invention and its preferred embodiments thus substantially increase the fault-tolerance of the network, because it does not need the centralized element that prevents group calls when it fails. At the same time, dimensioning the network becomes easier, because the centralized element does not play the main role in group call establishment.
The second specific advantage of the invention is the method that distributes the group call speech items and the speech item queuing without a centralized controlling element.
The system is suited for use both in circuit-switched and packet-switched speech and data transmission. The system is especially well suited for packet-switched point-to-multipoint speech transmission, which refers to multipoint traffic transmission from one traffic source to more than one destination point. An example of this is the point-to-multipoint technique of the IP network in signalling, managing group memberships and in speech transmission, when using a multicast facility.
In addition to the above advantages, a commercial benefit is also gained by the invention, when network and server systems commercially available on the market can be used.
It is apparent to a person skilled in the art that when the technology advances, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not restricted to the above examples, but may vary within the scope of the claims. | The invention relates to a method for supporting group communication between group members served by two or more controlling network elements in a communication network. The first subscriber (MS — 1 ) in the group requests a speech item in a group call from a first controlling network element (DXT_C) that (DXT_C) transmits the speech item request to all other controlling network elements (DXT_A, DXT_B) serving the members of the group. The other controlling network elements accept or reject the speech item request depending on their local speech item request situation in the group and notify the first controlling network element at least about the rejection. The first controlling network element grants the speech item only if both its own speech item request situation and the other controlling network elements allow the speech item. | 7 |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to security systems for residential or commercial buildings, and more particularly to an electrical or electronic security system which prevents an entrance door to the building both from being locked without first activating the security system, and from being unlocked without first deactivating the security system.
One of the seemingly inevitable consequences of our increasingly crowded urban society has been an ever-increasing crime rate, or at least the threat thereof. Breaking and entering and burglary have become increasingly common occurrences, affecting both residential property and commercial property. Accordingly, the sale and installation of various security systems, commonly known as burglar alarms, has become a thriving business as many property owners seek to discourage crime to property through the use of such systems.
The typical system for use to safeguard a building has five basic elements: a control unit, a power supply for powering the system, a main on/off switch, one or more sensors to detect illicit entry, and means for providing an alarm or other indication of the occurrence of unauthorized entry. The control units are electrical, or, more typically, electronic systems of considerable sophistication. Power supplies generally are connected to AC line voltage, with a DC battery backup. The main on/off switch is typically a numerical keypad, although in some cases key locks may be used. The sensors include devices to detect the opening of a door or window, pressure pads, and optical or sonic sensors. The alarm may be provided audibly, through the use of a horn or bell, or electronically to the police or to a security company to cause the police or security guards to promptly descend on the building to investigate the alarm.
There exist two major problems with alarm systems for use with buildings, and both are very basic problems. The first, and most serious, is the problem of remembering to activate the security system upon leaving the building. The second problem, also serious, is remembering to deactivate the system prior to entry into the building.
With regard to the first problem of remembering to arm the security system, it is almost inevitable that people will forget to activate the security system when leaving from time to time. The omission may occur accidentally through oversight, or it may occur deliberately, but in either event the all too frequently result is an illegal entry and property loss. It is accordingly a primary objective of the present invention to provide a system which will require the alarm system to be set without fail, each time the building is to be left by its inhabitants.
As might be expected, the art is not silent as to improvements and innovations encouraging the setting of the alarm system. Unfortunately, most such systems are intended for use with automobiles rather than with dwellings. Examples of such systems are illustrated in U.S. Pat. No. 3,936,673, to Kelly et al., in U.S. Pat. No. 4,225,008, to Colell et al., and in U.S. Pat. No. 4,635,035, to Ratzabi. All three of these systems use a combination lock and switch, with the car being locked or unlocked, and the alarm being simultaneously activated or deactivated with a key.
The Kelly et al. device teaches the basic concept, while the Colell et al. and Ratzabi devices go further and provide authorized keys which may perform both functions, while nonauthorized keys will merely lock or unlock the lock of the car, and not deactivate that alarm system. The basic problem with these systems is that a person who is adept at locks may gain entry to the vehicles, deactivating the alarm systems by picking the lock. While such systems are obviously better than no security system, they do not provide optimal security.
A similar system for use with buildings is disclosed in U.S. Pat. No. 4,370,644, to Droz. The Droz system has a switch operated by a sliding bolt in the door, and has the same problem as the other systems described above- namely that an intruder need only pick the lock to both gain entry and to disarm the security system. Today, most sophisticated security systems, both for automobiles and for dwellings, use numerical keyboards as the deactivation device (and also frequently as the activation device). As such, the security system may not be deactivated by merely picking the lock.
It is therefore an objective of the present invention to provide a security system which will not be capable of being deactivated by merely picking the entry lock. In addition, an improved system should also be set each time the building is left (at least for an extended period), or when the building is left in a locked condition. The improved system must not depend on being set by a person leaving the building. A number of automobile systems have an automatic setting feature initiated by removing the key from the ignition, but security systems for dwellings do not have such a feature. The automatic setting of the security system should not be initiated by merely locking the entry door, since entry doors of dwellings are commonly locked with the inhabitants inside.
The second major problem, namely of remembering to deactivate the security system, does not present the threat of property loss in the event of a failure to deactivate the system prior to entry. Rather, the problem presented is that of a false alarm occurring when someone forgets to deactivate the security system. The problem is annoying when forgetting to deactivate the system sets off a horn or bell, particularly at night when neighbors may be sleeping. It is minimal, however, since, the security system can usually be turned off quickly.
The problem is exacerbated when the alarm is provided to the police or to a private security agency, generally resulting in an armed patrol descending on the building. This may present a dangerous situation to the authorized person, who may be mistaken for a criminal. It is also expensive, since both the police and security agencies may charge for false alarms.
One of the solutions the art has provided to this problem is the provision of a low level alarm within the building for a short time to remind the person forgetting to deactivate the security system that the system is still on. This is at best a pseudo-solution to the problem, since it will also act as a warning to an illicit intruder. It is accordingly a primary objective of the present invention to provide a security system which will be deactivated prior to entry of the building.
Such a system must not be deactivated merely by unlocking the entry door, but rather must possess an independent deactivation mechanism. In addition, the system must absolutely prevent the building from being entered prior to the security system being deactivated. The system which is a solution to the problems enumerated above must also possess several other attributes. It must be both effective and easy to use, and is preferably of an unsophisticated design both to make it economic of manufacture and highly reliable. It must also eliminate all of the above problems and achieve all of the desired advantages and objectives without incurring any relative disadvantage.
SUMMARY OF THE INVENTION
The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a electromechanical interlock system is used to prevent an entry door from being locked with a deadbolt prior to activation of a security system. In addition, the electromechanical interlock system is also used to prevent the deadbolt from unlocking the entry door prior to deactivation of a security system. By requiring these two interlock mechanisms, all of the objectives and advantages of the present invention may be realized.
A conventional security system is used, with two electrical outputs from the security system being used to operate an interlocking mechanism. These two electrical outputs are an activate line, which has a voltage on it when the security system is armed (as by a numerical pad), and a disarm line, which has a voltage on it when the security system is disarmed. The two electrical outputs are used in the preferred embodiment to operate two solenoids, which in turn operate two longitudinally moveable spring-loaded solenoid shafts.
The deadbolt mechanism of the preferred embodiment has two notches located in the sliding bolt used to lock the entry door. The sliding bolt has two positions, namely an unlocked position and a locked position. When the sliding bolt is in the unlocked position, the first solenoid shaft is spring biased into the first notch in the sliding bolt. Only when the activate line energizes the first solenoid coil is the first solenoid shaft drawn out of the first notch, allowing the sliding bolt to be moved to the locked position.
With the sliding bolt in the locked position, the second solenoid shaft is spring biased into the second notch in the sliding bolt. Only when the deactivate line energizes the second solenoid coil is the second solenoid shaft drawn out of the second notch, allowing the sliding bolt to be moved to the unlocked position. This device thus accomplishes the objectives of the present invention, preventing the entrance door from being locked without first activating the security system, and from being unlocked without first deactivating the security system.
In a first alternate embodiment, a single notch is used on the sliding bolt, with the first solenoid shaft being spring biased into the notch when the sliding bolt is in the unlocked position. When the sliding bolt is moved to the locked position, the second solenoid shaft is spring biased into the notch.
In a second alternate embodiment, a single sliding mechanical interlock element replaces the first and second sliding solenoid shafts. The mechanical interlock element is spring biased into the first notch when the sliding bolt is in the unlocked position, and is removed from the first notch when the activate line energizes the solenoid. When the sliding bolt is in the locked position, the mechanical interlock element is drawn into the second notch as long as the activate line continues to energize the solenoid. The deactivate line is not used in this embodiment.
In a third alternate embodiment, the second solenoid shaft is spring biased to prevent a key from being inserted into the lock which moves the deadbolt. When the deactivate line is energized, the second solenoid shaft is moved to allow a key to be inserted into the lock. It will be appreciated by those skilled in the art that other system configurations could be used without departing from the principal of the present invention.
It may therefore be seen that the system of the present invention requires the alarm system to be set without fail, each time the building is to be left by its inhabitants in a locked condition. The system of the present invention also provides a security system which is not capable of being deactivated by merely picking the entry lock. In accordance with the design of the present invention, the automatic setting of the security system is not initiated by merely locking the entry door, thereby allowing the entry door of a building to be locked with the inhabitants inside.
The second primary objective of the present invention, namely the provision of a security system which will be deactivated prior to entry of the building, is also achieved. The system may not be deactivated merely by unlocking the entry door, but rather is required to have an independent deactivation mechanism. It will be appreciated that the system of the present invention thereby absolutely prevents the building from being entered prior to the security system being deactivated. The system also possesses several other attributes. It is both effective and easy to use, and is of an unsophisticated design making it both economic of manufacture and highly reliable. It also eliminates all of the above problems and achieves all of the desired advantages and objectives without incurring any relative disadvantage.
DESCRIPTION OF THE DRAWINGS
These and other advantages of the present invention are best understood with reference to the drawings, in which:
FIG. 1 is a schematic block diagram of the preferred embodiment of the present invention, with the electromechanical interlock being shown in a somewhat schematic cutaway view in the unlocked position;
FIG. 2 is a somewhat schematic cutaway view of the electromechanical interlock of FIG. 1 in the locked position;
FIG. 3 is a somewhat schematic cutaway view of a first alternate embodiment of the electromechanical interlock in the unlocked position;
FIG. 4 is a somewhat schematic cutaway view of a second alternate embodiment of the electromechanical interlock in the unlocked position;
FIG. 5 is a somewhat schematic sectional view of the electromechanical interlock shown in FIG. 4;
FIG. 6 is a somewhat schematic cutaway view of a third alternate embodiment of the electromechanical interlock in the unlocked position showing the first solenoid; and
FIG. 7 is a somewhat schematic sectional view of the electromechanical interlock shown in FIG. 6, showing the second solenoid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of a security system embodying the present invention is illustrated in FIG. 1. An alarm control unit 10 of conventional design is the main control unit used in a typical building security system. The electrical power to operate the security system is furnished from a power supply 12, which is also of conventional design. A backup battery 14 is used to supply power to the security system on occasions when the alarm control unit 10 detects that the power supply 12 has failed, with such use of a battery as an auxiliary power supply being common in the art.
The system is armed and disarmed through the use of a numerical keypad 16, with such keypads being known in the art. When the system is disarmed, the user may press a preset numerical sequence on the numerical keypad 16 to arm the system. This is accomplished by the numerical keypad 16 supplying an ARM signal to the alarm control unit 10 when the proper numerical sequence is entered. Similarly, the numerical keypad 16 will disarm the security system when the proper numerical sequence is again entered, causing the numerical keypad 16 to cease supplying the ARM signal to the alarm control unit 10.
In the example illustrated in FIG. 1, power is supplied to the numerical keypad 16 from the alarm control unit 10, and the ARM signal is a DC voltage sent from the numerical keypad 16 to the alarm control unit 10 to cause the system to be armed. When the numeric keypad 16 is operated with the system armed to disarm the system, the numerical keypad 16 will then cease supplying the DC voltage to the alarm control unit 10, thereby causing the system to be disarmed.
It will of course be appreciated by those skilled in the art that there are other ways of utilizing the numerical keypad 16 and the alarm control unit 10 to activate and deactivate the security system. It is only necessary for the purposes of the preferred embodiment of the present invention that when the security system is armed, a DC voltage appear on an ARM control line 18 to operate the present invention. Similarly, it is necessary that a DISARM signal be generated when the security system is disarmed. Like the ARM signal, the DISARM signal is a DC voltage which appears on a DISARM control line 20 when the security system is disarmed.
It will be noted that the ARM and DISARM signals are complementary, in that when the ARM signal is present the DISARM signal is not, and vice-versa. The preferred embodiment of the present invention illustrated in FIG. 1 uses the numerical keypad 16 to generate the ARM signal on the ARM control line 18 and the alarm control unit 10 to generate the DISARM signal on the DISARM control line 20. The alarm control unit lo generates the DISARM signal on the DISARM control line 20 whenever the alarm control unit 10 detects that the ARM signal is not present on the ARM control line 18.
The security system illustrated in FIG. 1 used sensors to detect an illicit entry, which sensors are of two types. A normally open sensor 22 is used in applications such as pressure pads, and three normally open sensors 22 are shown in FIG. 1 as inputs to the alarm control unit 10. The normally open sensors 22 may be wired in parallel as shown, so that when any one of them closes (indicating an illegal entry) an alarm will be initiated by the alarm control unit 10.
The other type of sensor is the normally closed sensor 24, which is used in applications such as door and window switches. Three normally closed sensors 24 are shown in FIG. 1, and must either be wired in series or separately to the alarm control unit 10, as shown in FIG. 1. It will therefore be appreciated that when any one of the normally open sensors 22 or the normally closed sensors 24 is triggered, the alarm control unit 10 will initiate an alarm. This operation is well known in the art, and is utilized by the system of the present invention rather than forming an essential part of the present invention.
When the alarm control unit 10 initiates an alarm, it will energize a horn 26 or other audible or inaudible signal. The horn 26 may be replaced, for example, with a bell, lights, or a signal which is sent to the police or to a security agency. In addition, a combination of different signals could also be used.
The above discussion is essentially a description of a known security system, with the possible exception of the ARM and DISARM signals. The use outside of the components described to this point of the ARM and DISARM signals form the heart of the present invention. It will be realized that the ARM and DISARM signals are DC voltages with respect to ground, and as such the ARM and DISARM voltages are used to operate the interlock system, also shown in FIG. 1.
Portions of a door 30 and a door jamb 32 are shown, with the door 30 having a lock 34 which reciprocally drives a bolt 36, typically in horizontal movement. When the bolt 36 is driven by the lock 34 to the position shown in FIG. 1, in which it is retracted into the door 30 (which position is called the unlocked position), the door 30 may be freely opened or closed. When the bolt 36 is driven by the lock 34 to extend beyond the door (while the door 30 is in a closed position adjacent the door jamb 32) into a recess 37 in the door jamb 32 as shown in FIG. 2 (which position is called the locked position), the door 30 may not then be opened or closed until the bolt 36 is once again retracted into the door 30 (as shown in FIG. 1).
The bolt 36 is shown in FIGS. 1 and 2 to have two notches therein, namely a first notch 38 located on the top of the bolt 36, and a second notch 40 located on the bottom of the bolt 36. The first notch 38 is located nearer to the edge of the door 30 from which the bolt 36 extends than is the second notch 40. The notches 38 and 40 may be cylindrical apertures, or they may be simple notches in the surface of the bolt 36, as shown in the figures.
Two solenoids are also located in the door 30, together with the lock 34 and the bolt 36. A first solenoid comprises a first solenoid shaft 42 which is mounted for reciprocal movement in a vertical axis orthogonal to the bolt 36. The first solenoid shaft 42 is located above the bolt 36. When the first solenoid shaft 42 is aligned with the first notch 38 in the bolt 36 as shown in FIG. 1, the first solenoid shaft 42 will engage the first notch 38, thereby preventing movement of the bolt 36. The first solenoid shaft 42 is biased in a downward position into engagement with the first notch 38 in the bolt 36 by a first spring 44.
A first solenoid coil 46 is located around the upper portion of the first solenoid shaft 42. When the first solenoid coil 46 is energized, the first solenoid shaft 42 will be drawn upward against the first spring 44 and out of the first notch 38 in the bolt 36, thereby allowing the bolt 36 to move from the unlocked position (FIG. 1) to the locked position (FIG. 2). The first solenoid coil 46 is energized by the ARM signal on the ARM control line 18. Therefore, whenever the ARM signal is present on the ARM control line 18, the first solenoid shaft 42 will be drawn upward by the first solenoid coil 46 to allow the bolt 36 to move from the unlocked position to the locked position.
Similarly, a second solenoid comprises a second solenoid shaft 48 which is also mounted for reciprocal movement in a vertical axis orthogonal to the bolt 36. The second solenoid shaft 48 is located below the bolt 36 (and the first solenoid shaft 42). When the second solenoid shaft 48 is aligned with the second notch 40 in the bolt 36 as shown in FIG. 2, the second solenoid shaft 48 will engage the second notch 40, thereby preventing movement of the bolt 36. The second solenoid shaft 48 is biased in a upward position into engagement with the second notch 40 in the bolt 36 by a second spring 50.
A second solenoid coil 52 is located around the lower portion of the second solenoid shaft 48. When the second solenoid coil 52 is energized, the second solenoid shaft 48 will be drawn downward against the second spring 50 and out of the second notch 40 in the bolt 36, thereby allowing the bolt 36 to move from the locked position (FIG. 2) back to the unlocked position (FIG. 1). The second solenoid coil 52 is energized by the DISARM signal on the DISARM control line 20. Therefore, whenever the DISARM signal is present on the DISARM control line 20, the second solenoid shaft 48 will be drawn downward to allow the bolt 36 to move from the locked position to the unlocked position.
The operation of the system of the present invention may now be discussed with reference to FIGS. 1 and 2. When a building is inhabited, the bolt 36 will be in the unlocked position shown in FIG. 1. In that position, the first solenoid shaft 42 is engaged with the first notch 38 in the bolt 36, thereby preventing the bolt 36 from being moved to the locked position. It is thereby apparent that the lock 30 may not be used to lock the door 30 while the first solenoid shaft 42 is engaged in the first notch 38 in the bolt 36.
The system of the present invention thereby requires that before the door 30 be locked, the alarm system be armed. Accordingly, the numerical keypad 16 is used to generate the ARM signal on the ARM control line 18 to arm the system. (Note that when the ARM signal is generated, the DISARM signal, generated by the alarm control unit 10, will cease.) When the ARM signal is generated on the ARM control line 18, the first solenoid coil 46 will be energized, drawing first solenoid shaft 42 out of the first notch 38 in the bolt 36. The bolt 36 may then be moved from the unlocked position to the locked position by the lock 34.
Similarly, with the alarm system activated and the bolt 36 in the locked position shown in FIG. 2, the second solenoid shaft 48 is engaged with the second notch 40 in the bolt 36, thereby preventing the bolt 36 from being moved to the unlocked position. It is thereby apparent that the lock 30 may not be used to unlock the door 30 while the second solenoid shaft 48 is engaged in the second notch 40 in the bolt 36.
The system of the present invention thereby requires that before the door 30 be unlocked, the alarm system must be disarmed. Accordingly, the numerical keypad 16 is used to disarm the system by ceasing the generation of the ARM signal on the ARM control line 18. (Note that when the ARM signal ceases being generated, the DISARM signal will be generated by the alarm control unit 10.) When the DISARM signal is generated on the DISARM control line 20, the second solenoid coil 52 will be energized, drawing the second solenoid shaft 48 out of the second notch 40 in the bolt 36. The bolt 36 may then be moved from the locked position to the unlocked position by the lock 34.
It is also desirable to allow the bolt 36 to be locked from inside the building without requiring that the security system be activated. This is accomplished by using a spring-loaded normally open switch 54, which spring-loaded normally open switch 54 must be mounted inside the building near the lock 34 in the door 30. One side of the spring-loaded normally open switch 54 is connected to the output of the power supply, which is generally a positive DC voltage. The other side of the springloaded normally open switch 54 is connected to the ARM control line 18.
It will be appreciated that when the spring-loaded normally open switch 54 is closed, the first solenoid coil 46 will be energized, drawing the first solenoid shaft 42 out of the first notch 38, thereby allowing the bolt 36 to be moved to the closed position. The spring-loaded normally open switch 54 will only operate momentarily when the bolt 36 is to be closed from the inside of the building, and will then open, deenergizing the first solenoid coil 46. As such, when the bolt 36 is in the locked position, the DISARM signal will be present, allowing the bolt 36 to be unlocked at any time.
The spring-loaded normally open switch 54 it therefore a sort of bypass of the system. It is important to note that this bypass cannot be used from the outside of the building, since the spring-loaded normally open switch 54 is located inside the building. Therefore, in order to lock the door 30 from the outside of the building, the bypass is not available and the security system must be armed before the bolt 36 may be locked.
It is therefore apparent that the system of the present invention effectively prevents the door 30 both from being locked (from the outside) before the alarm is armed, and from being unlocked before the alarm is disarmed. A number of different modifications to the system described with reference to FIGS. 1 and 2 are readily apparent without departing from the spirit of the present invention. For example, the first and second solenoids need not be on opposite sides of the bolt 36, or above and below each other. Other possible placements are equally possible.
A first alternate embodiment is illustrated in FIG. 3. A single notch 60 is located in the top of the bolt 36. Both the first and second solenoids are located over the bolt 36, with the second solenoid being located closer to the edge of the door 30 from which the bolt 36 protrudes than is the first solenoid. The first solenoid includes a first solenoid shaft 62, a first spring 64, and a first solenoid coil 66. When the alarm system is armed, the first solenoid coil 66 is energized by the ARM signal on the ARM control line 18 to allow the bolt 36 to be moved from the unlocked position shown to a locked position (not shown).
The second solenoid includes a second solenoid shaft 68, a second spring 70, and a second solenoid coil 72. When the alarm system is disarmed, the second solenoid coil 72 is energized by the DISARM signal on the DISARM control line 20 to allow the bolt 36 to be moved from the locked position (not shown) to the unlocked position shown.
A second alternate embodiment is illustrated in FIGS. 4 and 5. Instead of two conventional solenoids, a single solenoid of different design is used. The bolt 36 has the first notch 3 on the top and the second notch 40 on the bottom, in identical fashion to the arrangement of FIGS. 1 and 2. A solenoid core 80 having an aperture 82 therein is used, with the aperture 82 having the bolt 36 extending therethrough. When the bolt 36 is in the unlocked position shown in FIG. 4, a spring 84 biases the material of the solenoid core 80 around the top of the aperture 80 into the first notch 38, preventing the bolt 36 from moving from the unlocked position to the locked position.
A solenoid coil 86 is energized by the ARM signal on the ARM control line 18 to draw the solenoid core 80 upward against the bias of the spring 84. This allows the bolt 36 to be moved from the unlocked position shown to the locked position (not shown). Since the ARM signal will remain as long as the alarm system is armed, the solenoid core 80 will continue to be drawn upward, causing the material of the solenoid core around the bottom of the aperture 82 to engage the second notch 40. The bolt may not be moved from the locked position to the unlocked position until the ARM signal on the ARM control line 18 ceases, allowing the spring 84 to force the solenoid core downward from engagement with the second notch 40.
A third alternate embodiment is illustrated in FIGS. 6 and 7, using a first solenoid identical to the first solenoid of the preferred embodiment shown in FIGS. 1 and 2. The second solenoid is different, in that it functions to prevent a key (not shown) from being inserted into the lock 34 when the alarm is activated. Referring to FIG. 7, a second solenoid shaft 90 is biased upward in the path of a key (not shown) entering the lock 34 by a second spring 92.
The second solenoid shaft 90 is drawn downward against the second spring 92 and out of the way of a key (not shown) entering the lock 34 by a second solenoid coil 94, which is energized by the DISARM signal on the DISARM control line 20. Therefore, when the door 30 is locked, the alarm must be disarmed to generate the DISARM signal which causes the second solenoid coil 94 to draw the second solenoid shaft 90 out of the way of a key (not shown). This again prevents the door 30 from being unlocked before the alarm is disarmed. The second solenoid could be mounted in a variety of different ways to accomplish the objective of blocking the path of a key (not shown) into the lock 34.
It will be appreciated from the above description of the present invention that it positively requires the alarm system to be set each time the building is to be left by its inhabitants in a locked condition. In accordance with the design of the present invention, the automatic setting of the security system is not initiated by merely locking the entry door, thereby allowing the entry door of a building to be locked with the inhabitants inside.
The present invention also achieves the second primary objective of requiring the security system to be deactivated prior to entry of the building. The system of the present invention is not capable of being operated or deactivated by merely picking the entry lock. The system therefore has a fully independent deactivation mechanism. It absolutely prevents the building from being entered prior to the security system being deactivated.
The system of the present invention is both effective and easy to use, and is of a mechanically and electrically unsophisticated design making it both economic to manufacture and highly reliable. It eliminates all of the above problems discussed above, and achieves all of the desired advantages and objectives without incurring any relative disadvantage. As such it represents a highly desirable improvement in the technology of building security systems.
Although an exemplary embodiment of the present invention has been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications, and alterations should therefore be seen as within the scope of the present invention. | A device for use with security systems for residential or commercial buildings is disclosed which prevents an entrance door to the building both from being locked without first activating the security system, and from being unlocked without first deactivating the security system. The system uses an electromechanical interlock to prevent a deadbolt from being moved from an unlocked position to a locked position until the security system is armed. The eletromechanical interlock also prevents the deadbolt from being moved from the locked position to the unlocked position until the security system is disarmed. | 4 |
CROSS REFERENCED APPLICATIONS
This application claims the benefit of the disclosure of European patent application number 11306087.5 filed on Aug. 31, 2011 incorporated by reference in its entirety.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
This disclosure relates to compositions and methods for removing non-aqueous fluids from a subterranean wellbore.
During the construction of subterranean wells, it is common, during and after drilling, to place a tubular body in the wellbore. The tubular body may comprise drillpipe, casing, liner, coiled tubing or combinations thereof. The purpose of the tubular body is to act as a conduit through which desirable fluids from the well may travel and be collected. The tubular body is normally secured in the well by a cement sheath. The cement sheath provides mechanical support and hydraulic isolation between the zones or layers that the well penetrates. The latter function is important because it prevents hydraulic communication between zones that may result in contamination. For example, the cement sheath blocks fluids from oil or gas zones from entering the water table and polluting drinking water. In addition, to optimize a well's production efficiency, it may be desirable to isolate, for example, a gas-producing zone from an oil-producing zone. The cement sheath achieves hydraulic isolation because of its low permeability. In addition, intimate bonding between the cement sheath and both the tubular body and borehole is necessary to prevent leaks.
The cement sheath is usually placed in the annular region between the outside of the tubular body and the subterranean borehole wall by pumping the cement slurry down the interior of the tubular body, out the bottom and up into the annulus. The cement slurry may also be placed by the “reverse cementing” method, whereby the slurry is pumped directly down into the annular space. During the cementing process, the cement slurry is frequently preceded by a spacer fluid or chemical wash to prevent commingling with drilling fluid in the wellbore. These fluids also help clean the tubular-body and formation surfaces, promoting better cement bonding and zonal isolation. The cement slurry may also be followed by a displacement fluid such as water or a brine. This fluid usually resides inside the tubular body after the cementing process is complete. A complete description of the cementing process and the use of spacer fluids and chemical washes is presented in the following publications. Piot B and Cuvillier G: “Primary Cementing Techniques,” in Nelson E B and Guillot D: Well Cementing -2 nd Edition , Houston, Schlumberger (2006) 459-501. Daccord G, Guillot D and Nilsson F: “Mud Removal,” in in Nelson E B and Guillot D: Well Cementing -2 nd Edition , Houston, Schlumberger (2006) 143-189.
Drilling-fluid removal and wellbore cleaning may be challenging when the well has been drilled with non-aqueous fluids. In the art of well cementing, non-aqueous fluids may be oil-base muds or water-in-oil emulsions. Conventionally, operators employ water-base spacer fluids or chemical washes comprising surfactants that render the fluids compatible with non-aqueous fluids. In the context of well cementing, fluids are compatible when no negative rheological effects such as gelation occur upon their commingling. Such effects may hinder proper fluid displacement, leaving gelled fluid in the wellbore and reducing the likelihood of achieving proper zonal isolation. Ideally, the spacer fluid, chemical wash or both will completely remove the non-aqueous fluid and leave casing and formation surfaces in the annulus water wet. Water-wet surfaces may promote intimate bonding between the cement sheath and casing and formation surfaces.
Many of the surfactants commonly used in the art to impart compatibility of spacer fluids and chemical washes with non-aqueous fluids may not be suitable for use in regions where governmental regulations restrict their use, disposal, or both. Therefore, despite the valuable contributions of the prior art, it remains desirable to have materials and methods by which non-aqueous fluids may be removed from a wellbore, yet comply with governmental regulations.
SUMMARY
The present disclosure describes such improvements. Aqueous fluid including (but not limited to) spacer fluids, chemical washes, drilling fluids and cement slurries are provided that are compatible with non-aqueous fluids and have the ability to remove them from a wellbore during a cementing treatment. In an aspect, embodiments relate to methods for cleaning surfaces coated with a non-aqueous fluid. In a further aspect, embodiments relate to methods for cementing a subterranean well.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
A drawing shows a diagram illustrating the ability of lipophilic fibers to remove non-aqueous fluids from casing and formation surfaces in a wellbore.
DETAILED DESCRIPTION
At the outset, it should be noted that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The description and examples are presented solely for the purpose of illustrating the preferred embodiments should not be construed as a limitation to the scope and applicability of the disclosed embodiments. While the compositions of the present disclosure are described herein as comprising certain materials, it should be understood that the composition could optionally comprise two or more chemically different materials. In addition, the composition can also comprise some components other than the ones already cited.
The Applicants have determined that aqueous treatment fluids comprising lipophilic fibers may clean surfaces that are coated with a non-aqueous fluid.
Embodiments relate to methods for cleaning surfaces coated with a non-aqueous fluid. Such surfaces comprise a borehole in a subterranean well whose surfaces are coated with a non-aqueous fluid. An aqueous treatment fluid is provided that comprises lipophilic fibers. The aqueous treatment fluid may comprise (but would not be limited to) a drilling fluid, a spacer fluid, a chemical wash, or a cement slurry, or combinations thereof.
The fibers may comprise polypropylene-isotactic, polypropylene-atactic, polypropylene-syndiotactic, polyester, polydimethylsiloxane, polytetrafluoroethylene, polytrifluoroethylene, polyhexylmethacrylate, polyvinylidene fluoride, poly(t-butylmethacrylate), polychlorotrifluoroethylene, polyisobutylmethacrylate, polybutylmethacrylate, polytetramethylene oxide, polytetrahydrofurane, polyisobutylene, polycarbonate, polyethylene-branched, polyethylene-linear, polyethylmethacrylate, polyvinylacetate, polyvinyl fluoride, polyethylacrylate, poly-a-methyl styrene, polyvinyltoluene, polystyrene, polyamide-12, polymethylacrylate, polymethylmethacrylate, polyvinylchloride, polyetheretherketone, polyethylene oxide, polyethyleneterephthalate, polyvinylidine chloride, or polyamide-6,6, and combinations thereof. The fiber length may be between about 5 mm and 50 mm. The fiber geometry may be cylindrical, trilobal, ribbon like, or grooved, and combinations thereof. An example of a grooved fiber is 4DG™ fibers from Fiber Innovation Technology, Inc., Johnson City, Tenn. 37604, USA. The fibers may be further coated with a hydrophilic material, or sizing, to promote dispersion in the aqueous medium. Suitable coatings may include (but would not be limited to) starch, xanthan polymers, diutan, scleroglucan, guar, guar derivatives, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohols, or water-soluble acrylates and combinations thereof.
The solid surface energy of the fibers may be less than the surface tension of water, or between about 20 mN/m and 40 mN/m. For efficiency, the fibers are selected such that they may absorb between about 10 times to about 60 times their weight of non-aqueous fluid.
The surfaces coated with non-aqueous fluid are placed in contact with the treatment fluid. In a wellbore, the treatment fluid may be circulated, for example in the annular space between the casing (or other tubular body) and the subterranean formation wall. The circulation of the treatment fluid may remove the non-aqueous fluid, filter cake or both from the casing and formation surfaces, leaving them water wet. The treatment fluid is then removed from the wellbore. The treatment fluid may further comprise a surfactant. Suitable surfactants may include (but would not be limited to) alkylammonium compounds, dodecyl benzene sulfonate, derivatives of oxyethylated esters of fatty acids and polyglycol esters of alkyl phenols.
The treatment fluid is then removed from the wellbore, leaving the tubular-body and formation surfaces water wet.
One example of the method is illustrated in the drawing. Casing 101 is present in the wellbore, and a non-aqueous coating 104 is deposited on its surface. On the other side of the annular space, a non-aqueous coating 104 also is attached to the formation wall 102 . The treatment fluid comprising lipophilic fibers 105 is flowing upward 103 in the annular space. The lipophilic nature of the fibers causes the non-aqueous coating to be removed from the casing and formation surfaces as they travel up the annulus.
Embodiments relate to methods for cementing a subterranean well. An aqueous treatment fluid is provided that comprises lipophilic fibers. The aqueous treatment fluid may comprise a drilling fluid, a spacer fluid, a chemical wash, or a cement slurry, or combinations thereof.
The fibers may comprise polypropylene-isotactic, polypropylene-atactic, polypropylene-syndiotactic, polyester, polydimethylsiloxane, polytetrafluoroethylene, polytrifluoroethylene, polyhexylmethacrylate, polyvinylidene fluoride, poly(t-butylmethacrylate), polychlorotrifluoroethylene, polyisobutylmethacrylate, polybutylmethacrylate, polytetramethylene oxide, polytetrahydrofurane, polyisobutylene, polycarbonate, polyethylene-branched, polyethylene-linear, polyethylmethacrylate, polyvinylacetate, polyvinyl fluoride, polyethylacrylate, poly-a-methyl styrene, polyvinyltoluene, polystyrene, polyamide-12, polymethylacrylate, polymethylmethacrylate, polyvinylchloride, polyetheretherketone, polyethylene oxide, polyethyleneterephthalate, polyvinylidine chloride, or polyamide-6,6, and combinations thereof. The fiber length may be between about 5 mm and 50 mm. The fiber geometry may be cylindrical, trilobal, ribbon like, or grooved, and combinations thereof. An example of a grooved fiber is 4DG™ fibers from Fiber Innovation Technology, Inc., Johnson City, Tenn. 37604, USA. The fibers may be further coated with a hydrophilic material, or sizing, to promote dispersion in the aqueous medium. Suitable coatings may include (but would not be limited to) starch, xanthan polymers diutan, scleroglucan, guar, guar derivatives, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohols, or water-soluble acrylates and combinations thereof.
The solid surface energy of the fibers is may be less than the surface tension of water, or between about 20 mN/m and 40 mN/m. For efficiency, the fibers are selected such that they may absorb between about 10 times to about 60 times their weight of non-aqueous fluid.
The treatment fluid is circulated in the wellbore, for example in the annular space between the casing (or other tubular body) and the subterranean formation wall. The circulation of the treatment fluid may remove the non-aqueous fluid, filter cake or both from the casing and formation surfaces, leaving them water wet. The treatment fluid is then removed from the wellbore. The treatment fluid may further comprise a surfactant. Suitable surfactants may include (but would not be limited to) alkylammonium compounds, dodecyl benzene sulfonate, derivatives of oxyethylated esters of fatty acids and polyglycol esters of alkyl phenols.
The treatment fluid is then removed from the wellbore, leaving the tubular-body and formation surfaces water wet.
A cement slurry is then provided and placed in the annular space between the tubular body and the subterranean-formation wall.
Example
The following example serves to further illustrate the invention.
40 mL of water containing 0.25 wt % polyolefin fibers, with a length of 18-20 mm and a diameter less than about 0.03 mm, were placed in a 50-mL glass vial with a cap. 0.2 mL of an water-in-oil emulsion drilling fluid from MI SWACO, Houston, Tex. USA were added to the vial. After capping the vial, the mixture was shaken. The drilling fluid was attracted to the fibers, allowing the fluid to be removed from the vial with the fibers. Clear water was left in the vial.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. | Lipophilic fibers are effective media for cleaning non-aqueous fluids out of a subterranean wellbore. The fibers are preferably added to a drilling fluid, a spacer fluid, a chemical wash, a cement slurry or combinations thereof. Non-aqueous fluids, such as an oil-base mud or a water-in-oil emulsion mud, are attracted to the fibers as they circulate in the wellbore. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a control apparatus for an oil-pressure operated type transmission for a vehicle and, more particularly, to a transmission connected through a torque converter to an internal combustion engine. The transmission has at least two transmission trains of high speed and low speed, each having oil-pressure operated type engaging elements, such as oil-pressure operated type clutches or the like interposed therein and the low speed transmission train is provided with a one-way clutch interposed therein. The control apparatus further includes a creep-preventing means.
2. Description of the Prior Art
In general, in a two-stage transmission having oil-pressure operated clutches, a one-way clutch effectively absorbs a change speed shock at the time of upshifting from the low speed stage. However, at the time of stopping of a vehicle, if idling operation is effected without returning the shift lever to the neutral position, the low speed transmission train is established regardless of the existence or nonexistence of the one-way clutch and the engine torque is transmitted therethrough to driving wheels of the vehicle to cause a creep phenomenon in which the vehicle moves.
For preventing this creep phenomenon, there has been hitherto proposed an arrangement in which a creep-preventing means is operated when an idling operation of the engine, under a vehicle stop condition, is detected so that oil is supplied to cut off the low speed engaging element in the low speed transmission train and automatically return the transmission to its neutral stage. Upon a vehicle starting operation with the accelerator pedal being pushed down, the oil supply to that element is resumed to automatically shift from the neutral stage to the low speed stage. (Japanese Unexamined U.M. Application No. SHO 54-139171). This prior art arrangement, however, is inconvenient in that rapid revving of the engine is caused by a time lag between the time of pushing-down of the accelerator pedal and the time of establishment of the low speed transmission train, and a rapid starting of the vehicle by the establishment of the transmission train with a high speed results in unsmooth vehicle starting.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to provide a control apparatus for a multispeed vehicle transmission which has a creep-preventing device.
It is a further object of the present invention to provide a control apparatus for a multispeed transmission which prevents creeping and provides for smooth starting of a vehicle.
The present invention is directed to a control apparatus for a vehicle transmission having at least two speeds. The transmission has at least one high speed transmission train and one low speed transmission train, which includes a one-way clutch. Each of the transmission trains includes a hydraulic clutch. The control apparatus comprises a hydraulic circuit coupled to each of the hydraulic clutches and creep-preventing means for operating in response to idling of the vehicle engine when the vehicle is stopped to make the clutch of the high speed transmission engaged. The clutch of the low speed transmission is engaged during idling and stopping, but power is not transmitted therethrough by the function of the one-way clutch interposed therein. However, upon actuation of the vehicle accelerator, the one-way clutch becomes operative and the low speed transmission train transmits power.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a transmission with which the present invention is used; and
FIG. 2 is a circuit diagram of the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the transmission 1 has an input shaft 1a connected to an internal combustion engine 2 through a torque converter 3, and an output shaft 1b is connected to driving wheels 4 of a vehicle through a differential gear 5. Transmission trains G1, G2, G3, GR of three forward stages and one reverse stage are coupled between the two shafts 1a, 1b. A 1st speed oil pressure operated clutch C1 on the input shaft 1a functions as an oil pressure operated engaging element coupled in the 1st speed transmission train G1 of the forward low speed stage, a 2nd speed oil pressure operated clutch C2 on the input shaft 1a is coupled in the 2nd speed transmission train G2 of the middle speed stage, and a 3rd speed oil pressure operated clutch C3 on the output shaft 1b is coupled in a 3rd speed transmission train G3 of the forward high speed stage. Additionally, the 2nd speed oil pressure operated clutch C2 is also coupled in the reverse driving transmission train GR so that the two transmission trains GR, G2 may be selectively connected to the output shaft 1b by a selector gear 6 movable between the forward driving side towards the left and the reverse driving side towards the right as viewed in FIG. 1.
A one-way clutch 7 is coupled in the 1st speed transmission train G1 and, as will be explained hereinafter, the one-way clutch 7 which is, for instance, a ball type or roller type overrunning clutch, is arranged to absorb a change speed shock at the time of shifting-up from the 1st speed to the 2nd speed as explained hereinafter.
The oil pressure operated clutches C1, C2, C3 and the selector gear 6 are arranged to be controlled in operation by an oil pressure circuit shown in FIG. 2. The circuit comprises an oil pressure source 8 arranged to be driven by the engine 2 and a manual valve 9, which can be shifted by a shift lever, not illustrated, to any of the five positions of "P" for parking, "R" for reverse, "N" for neutral, "D" for automatic change speed and "2" for 2nd speed holding. A servo-valve 10, for changeover between forward driving and reverse driving, is connected to the selector gear 6 and 1st and 2nd shift valves 11, 12 are provided for effecting the automatic change speed.
The manual valve 9 is arranged to be brought into respective communications with a 1st oil passage L1 connected to the oil-pressure source 8, a 2nd oil passage L2 connected to the 1st speed oil-pressure operated clutch C1 and the 1st shift valve 11, a pair of 3rd and 4th oil passage L3, L4 connected to the servo-valve 10 and located on the upstream side thereof, a 5th oil passage L5 connected to the valve 10 and located on the downstream side thereof, a 6th oil passage L6 connected to the 2nd shift valve 12 and located on the downstream side thereof, and a 7th oil passage L7 connected to the 2nd speed oil-pressure operated clutch C2. Thus, if the manual valve 9 is shifted from the illustrated "N" position to the rightward "R" position, the 1st oil passage L1 and the 3rd oil passage L3 are interconnected and the 5th oil passage L5 and the 7th oil passage L7 are interconnected, respectively, so that, by oil being supplied to the 3rd oil passage L3, the servo-valve 10 is moved to the rightward reverse driving position against the action of a spring force, resulting in a changeover operation of the selector gear 6 to the reverse driving side. Additionally, there is communication between the 3rd oil passage L3 and the 5th oil passage L5 through an oil opening 10a made in the servo-valve 10. Thereby the 2nd speed oil pressure operated clutch C2 is supplied with oil through the 1st oil passage L1, the 3rd oil passage L3, with 5th oil passage L5 and the 7th oil passage L7, whereby there is established the reverse driving transmission train GR.
If the manual valve 9 is shifted from the "N" position to the leftward "D" position, the 1st oil passage L1 is connected to the 2nd and 4th oil passages L2, L4 and the 6th oil passage L6 is connected to the 7th oil passage L7 and, by operation of the 1st and 2nd shift valves 11, 12, the 1st speed to 3rd speed oil-pressure operated clutches C1, C2, C3 are in sequence supplied with oil for establishing the respective speed transmission trains G1, G2, G3 in sequence. If the manual valve 9 is shifted from the "D" position to the "2" position, the 1st oil passage L1 and the 4th oil passage L4 are interconnected and the 5th oil passage L5 and the 7th oil passage L7 are interconnected, respectively. The servo-valve 10 is already in its forward driving position as a result of the spring pressure, and thereby there is a changeover operation of the selector gear 6 to the forward driving side and a connection between the 4th oil passage L4 and the 5th oil passage L5, whereby the 2nd speed transmission train G2 is established by the oil supply to the 2nd speed oil pressure operated clutch C2.
The 1st and 2nd shift valves 11 and 12 are interconnected through an intermediate 8th oil passage L8 and the 1st shift valve 11 is movable between its illustrated low speed position wherein the connection between the 2nd oil passage L2 and the 8th oil passage L8 is cut off and its leftward high speed position (not shown) wherein the two oil passages L2 and L8 are interconnected. The 2nd shift valve 12 is movable between its illustrated low speed position wherein the 8th oil passage L8 and the 6th oil passage L6 are interconnected and its left hand high speed position (not shown) wherein the interconnection of the oil passage L8, L6 is cut off and the 8th oil passage L8 is connected to the 9th oil passage L9 connected to the 3rd speed oil-pressure operated clutch C3. The 1st and 2nd shift valves 11 and 12 are biased to the low speed positions thereof by respective spring forces, and the left ends and the right ends of the two valves 11 and 12 are applied with a throttle pressure corresponding to a throttle open degree received from a throttle valve 13 connected to a split passage of the 4th oil passage L4 and a governor pressure corresponding to a vehicle speed supplied from a governor valve 14. Thus, if the governor pressure is increased, first the 1st shift valve 11 is moved to its high speed position and then the 2nd shift valve 12 is moved to its high speed position.
If the manual valve 9 is in the "D" position, first, the 1st speed oil-pressure operated clutch C1 is supplied with oil through the 2nd oil passage L2 connected to the 1st oil passage L1 as described above. Thereby a vehicle is driven through the 1st speed transmission train G1. Then, by an increase in the governor pressure according to an acceleration of the vehicle, the 1st shift valve 11 is moved to the high speed position and, consequently, the 2nd speed oil-pressure operated clutch C2 is supplied with oil through the 2nd oil passage L2, the 8th oil passage L8, the 6th oil passage L6 and the 7th oil passage L7, whereby the vehicle is driven through the 2nd speed transmission train G2. If the vehicle speed is further increased, the 2nd shift valve 12 is moved to the high speed position and the 3rd speed oil pressure operated clutch C3 is supplied with oil through the 8th oil passage L8 and the 9th oil passage L9, whereby the vehicle is driven through the 3rd speed transmission train G3.
During these operations, the 1st speed oil-pressure operated clutch C1 is always supplied with oil, but because the one-way clutch is interposed in the 1st speed transmission train G1 as described above, when the 2nd speed transmission train G2 or the 3rd speed transmission train G3 are established, there is no power transmission through the 1st speed transmission train G1. Upon upshifting from the 1st speed to the 2nd speed, when the rotation speed of the output shaft 1b becomes above that caused by the 1st speed transmission train G1, the one-way clutch 7 makes the 1st speed transmission train G1 inoperative automatically whereby it functions effectively to make a smooth speed change without causing any change speed shock, from the 1st speed transmission train G1 to the 2nd speed transmission train G2.
A regulator valve 15 supplies pressure oil from the 1st oil passage L1 divergingly to the torque converter 3 and regulates the line pressure of the 1st oil passage L1 to that corresponding to a stator reaction force of the torque converter 3. Accumulators 16 and 17 are also included in the hydraulic circuit.
If, with the oil pressure circuit arrangement as described above, the manual valve 9 is in the "D" position, the 1st oil passage L1 and the second oil passage L2 are in communication with one another as described above, even when the vehicle is stopped and, on an idling operation of the engine, the engine torque is transmitted to the driving wheels 4 of the vehicle through the 1st speed transmission train G1 caused by oil supplied to the 1st speed oil pressure operated clutch C1. This results in a creep phenomenon.
As a countermeasure, there has been hitherto, as mentioned before, a proposal to provide a creep-preventing means arranged to be operated when the idling operation of the engine under the vehicle stopped condition is detected so that, by the operation of the preventing means, the oil supply to the 1st speed oil pressure operated clutch C1 is cut off to make the 1st speed transmission train G1 inoperative. Such a proposed arrangement, however, is inconvenient in that there is revving of the engine or a sudden starting of the vehicle as mentioned above. According to the present invention, the one-way clutch 7 interposed in the 1st speed transmission train G1 is arranged so that the 3rd speed oil pressure operated clutch C3 is supplied with oil to establish the 3rd speed transmission train G3 while the oil supply to the 1st speed oil pressure operated clutch C1 is continued, whereby the 1st speed transmission train G1 is inoperative by the function of the one-way clutch 7.
A creep-preventing means 18 comprises a control valve 19 which connects and disconnects the 2nd oil passage L2 and the 10th oil passage L10 for applying the governor pressure from the governor valve 14 to the right ends of the 1st and 2nd shift valves 11 and 12. A switch means 21 controls an electric power supply to a solenoid 20 for the valve 19. The control valve 19 functions such that it is normally biased to its rightward inoperative position by the resilient pressure of a spring to cut off a communication between the 2nd oil passage L2 and the 10th oil passage L10. But if the solenoid 20 is energized, it is moved to its leftward operative position to make the communication between the two oil passages L2 and L10, so that the line pressure is applied to the right ends of the 1st and 2nd shift valves 11 and 12 to move the two valves 11 and 12 to their high speed positions, whereby oil is supplied to the 3rd speed oil-pressure operated clutch C3 through the 2nd oil passage L2, the 8th oil passage L8 and the 9th oil passage L9. A one-way valve 22 is provided for preventing a reverse flow of the line pressure towards the governor valve 14 side.
A modification can be made in which the plungers are provided at the right end positions of the 1st and 2nd shift valves 11 and 12 and a line pressure is applied to the respective valves 11 and 12 through those plungers from an oil passage other than the 10th oil passage L10. In this case, the control valve 19 is interposed in that oil passage for opening and closing the same.
The switch means includes a 1st switch 23 which is closed upon detecting a vehicle stop condition and a 2nd switch 24 which is closed upon detecting an idling operation of the engine, such as the idle position of the acceleration pedal, for instance. The switches 23 and 24 are coupled in series in an electric power circuit for the solenoid 20 such that, upon idling of the engine under a vehicle stop condition, the solenoid 20 is energized by closing the two switches 23 and 24.
It is difficult in practice to detect only the stop condition of a vehicle and, therefore, the 1st switch 23 is arranged to be closed when the vehicle speed falls below 5Km/h, for example. Also, the 1st switch 23 can be arranged to be closed when the engine speed corresponding to the foregoing vehicle speed at the 1st speed stage falls below 1000 rpm, for example.
Next, the operation of the apparatus will be explained as follows:
If the engine 2 is idling when the vehicle is stopped with the manual valve 9 in the "D" position, the 1st and 2nd switches 23 and 24 are closed and there is a movement of the control valve 19 to its operative position by the energization of the solenoid 20. By such an operation of the creep-preventing means 18, there is effected an oil supply to the 3rd speed oil-pressure operated clutch C3.
The 1st speed oil-pressure operated clutch C1 is continuously supplied with oil through the 2nd oil passage L2 but, by the establishment of the 3rd speed transmission train G3 caused by the oil supply to the 3rd speed oil pressure operated clutch C3, the 1st speed transmission train G1 is inoperative because the one-way clutch 7 is interposed therein. In this case, the output torque of the engine is transmitted to the driving wheels 4 through the 3rd speed transmission train G3, but this torque is extremely small and the creep phenomenon is substantially lower than that caused through the 1st speed transmission train G1.
If then, the vehicle is started by pressing down of the acceleration pedal, the 2nd switch 24 is opened to cut off the electric power supply to the solenoid 20 and the control valve 19 is returned to its inoperative position and the operation of the creep-preventing means 18 is released.
By the release of the operation thereof, the oil supply to the 3rd speed oil-pressure operated clutch C3 is cut off but the oil supply to the first speed oil-pressure operated clutch C1 is continued. Accordingly, simultaneously with that, the 3rd speed transmission train G3 being made inoperative by the oil discharge from the 3rd speed oil-pressure operated clutch C3, the 1st speed transmission train G1 is established. Thereby a smooth vehicle starting is effected without causing a revving up of the engine 2.
The above is related to a transmission with three forward speeds, but this invention is not limited thereto but can be applied to a transmission with four forward speeds. In this case, the creep-preventing means is so constructed that, by the operation thereof, the 3rd speed or the 4th speed oil-pressure operated clutch may be supplied with oil. Though there has been explained in the foregoing example a transmission in which the oil pressure operated clutch is used as the oil pressure operated engaging element, this invention can also be applicable to an oil pressure brake or the like used as the oil pressure operated engaging element in a planetary gear mechanism type transmission.
Thus, according to this invention, the operation of the creep-preventing means, with the oil supply to the low speed oil-pressure engaging element being continued, the high speed oil-pressure engaging element is supplied with oil to establish the high speed transmission train, and the low speed transmission train, even though having oil supplied thereto, is made inoperative by the function of a one-way clutch interposed therein. Thus, the creep phenomenon can be remarkably decreased as compared with the case in which the low speed transmission train remains established. In addition, the oil is supplied to the low speed oil pressure operated engaging element prior to the time of release of the operation of the creep-preventing means at the starting of the vehicle, so that the low speed transmission train can be established at the same time of the high speed transmission train becoming inoperative. Thus, there is no time lag during that time and a revving up of the engine can be prevented and, accordingly, smooth vehicle starting can be obtained.
The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are, 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 the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, to be embraced therein. | A control apparatus for a vehicle transmission is provided which has at least two transmission trains, which includes a high speed transmission train and a low speed transmission train. The low speed transmission train includes a one-way clutch. Each of the transmission trains have a clutch therein. The control apparatus comprises a hydraulic circuit coupled to the clutch and a creep-preventer which is coupled to the hydraulic circuit for operating in response to the idling of the vehicle engine when the vehicle is stopped, and to make the one-way clutch inoperative to prevent transmission of power through the low speed transmission when the clutch of the high speed transmission is engaged, to thereby permit operation of the clutch of the low speed transmission train without the transmission of power therethrough. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to an apparatus to enable an operator to maintain visual contact with instruments or other visual sources of data after smoke and/or particulate from a fire or other sources has invaded the operator's environment. In particular, the present invention relates to a gas activated expandable hand-held enclosure that bridges the gap between the pilot and the windshield and/or instrument panel along the pilot's line of sight and provide a clear viewing path to the windshield and/or the instrument panel, thereby providing him with vital information for guiding the aircraft to a safe landing after smoke and/or particulate matter invades the cockpit area.
BACKGROUND OF THE INVENTION
[0002] Emergency vision devices for aiding pilots to see through vision-impairing smoke to maintain their visual access to critical information, such as that provided by an instrument panel and visual information available outside the cockpit to help pilots safely guide their aircrafts are disclosed in U.S. Pat. Nos. 4,832,287; 5,318,250; 5,202,798; 5,947,415 and 6,460,804, all issued to Bertil Werjefelt.
[0003] The present invention is an improvement over U.S. Pat. No. 6,460,804.
OBJECTS AND SUMMARY OF THE INVENTION
[0004] It is an object of the present invention to provide an emergency vision device that is relatively compact and easily fits within a brief case.
[0005] It is another object of the present invention to provide an emergency vision device that is portable, lightweight and easily handled by the operator to assist him in various procedures and checklists required to operate an aircraft while under emergency smoke conditions.
[0006] It is still another object of the present invention to provide an emergency vision device that takes on a smaller shape for stowage when not in use and uses compressed gas to inflate it for deployment when the need arises.
[0007] In summary, the present invention provides an emergency vision device, comprising a collapsible tube made of airtight material and having an expanded form and a deflated stowage form; first and second clear members disposed at respective first and second ends of the tube to enable a user to see through the tube and observe a source of information at a distal end of the tube while smoke or other particulate matter is in the environment; and a portable gas cylinder having compressed clear gas and an outlet operably connected to the interior of the tube. The gas cylinder is operable to release the clear gas to fill the interior of the tube to expand the tube to the expanded form.
[0008] These and other objects of the invention will be apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of an emergency vision device, shown in its deployed inflated form.
[0010] FIG. 2 is a partial cross-sectional view taken along line 2 - 2 of FIG. 1 .
[0011] FIG. 3 is a perspective view of the device shown in FIG. 1 in a deflated stowage form.
[0012] FIG. 4 is a perspective view of the emergency vision device of FIG. 1 , showing straps for holding a flashlight.
[0013] FIG. 5 is another embodiment of an emergency vision device, shown in its deployed form.
[0014] FIG. 6 is a partial cross-sectional view across taken along line 6 - 6 of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
[0015] An emergency vision device R made in accordance with the present invention is disclosed in FIGS. 1 and 2 in a deployed inflated form. The device is in the form of a collapsible hand-held tube 2 made from an airtight fabric or other suitable materials. The tube 2 may be made from transparent or opaque material. The tube 2 is closed off at each end with respective transparent member 4 , such as clear plastic sheet, to allow the user to see through the tube. The tube 2 is sealed from the outside such that smoke or other particulate from a fire is prevented from invading the interior of the tube. In this manner, a clear view from one end to the opposite end of the tube is maintained for the user.
[0016] A gas cylinder 6 containing clear compressed gas is disposed within a hollow handle 8 . The gas cylinder 6 is screwed to a standard valve assembly 7 , such as the one commonly used in a hand-held fire extinguisher. The gas cylinder 6 is used inflate the tube 2 from its deflated stowage form (see FIG. 3 ) to its deployed inflated form. The valve assembly 7 includes an activation lever 10 the operation of which causes the gas to flow into the interior of the tube 2 , causing the tube to expand to its deployed form. A string 12 is advantageously secured to one end of the lever 10 for convenience so that when the tube 2 is in the deflated form, as shown in FIG. 3 , the string 12 may be positioned in a visible location to the user for quick activation of the gas cylinder when the need arises to deploy the device R. An outlet 14 of the valve assembly 7 operably communicates with the interior of the tube 2 to fill and inflate the tube 2 when the gas from cylinder 6 is released.
[0017] The handle 8 is made in a standard way such that it can be opened to provide access to the cylinder 6 for replacement after each use.
[0018] A light source 16 with its own battery power and switch may be provided at one end of the tube 2 .
[0019] A closeable outlet 18 is provided to exhaust the gas from the interior of the tube 2 when deflating the device to its deflated and stowage form.
[0020] When not in use, the device R is in a deflated stowage form, as shown in FIG. 3 , and may be placed within a pouch (not shown). To deploy the device R, the lever 10 is operated in the conventional manner, activating the cylinder to release its content to the interior of the tube 2 via the inlet 14 , thereby inflating the tube 2 . The light 12 provides illumination on the object requiring visual-visibility to the operator.
[0021] In lieu of the light 16 or in addition to it, a flashlight 20 may be attached to the outside of the tube 2 . Straps 22 with hook-and-loop fastener 24 are attached to the tube 2 for securing the flashlight. Other conventional ways to attach the flashlight to the tube may be used.
[0022] Although the tube 2 is shown with a circular cross-section, generally in the shape of a cylinder, it should be understood that any cross-sectional shape would be applicable as long as a clear visibility path is provided through the tube.
[0023] In another embodiment, the tube 2 is surrounded and attached to a network of substantially smaller tubes 26 . The tubes 26 comprise end ring tubes 28 disposed at the respective front and rear end of the tube 2 . Intermediate ring tubes 30 are disposed intermediate the front and rear end of the tube 2 . Longitudinal tubes 32 connect the end ring tubes 28 and the intermediate ring tubes 30 into one communicating network of tubes. The network of tubes 26 provides a supporting framework when inflated to the tube 2 . Although a specific arrangement of small tubes 28 , 30 and 32 is disclosed, other arrangements may be used that would provide the same function of supporting the tube 2 in the deployed form. The ring tubes 28 and 30 and the longitudinal tubes 32 have a cross-sectional area substantially smaller than the cross-sectional area of the main tube 2 .
[0024] The outlet 14 of the valve assembly 7 communicates with the network of tubes 26 , preferably via one of the intermediate ring tubes 30 , as best shown in FIG. 6 . In this manner, the compressed gas fills up the network of tubes 26 relatively quickly, with the gas filling up the ring tube which functions as a header, connecting the longitudinal tubes 32 and the other ring tubes to facilitate the flow of the gas. Advantageously, the gas cylinder 6 only needs sufficient capacity to fill up the network of tubes 26 , which is much smaller than the volume required to fill up the tube 2 . Thus, the gas cylinder 6 for this embodiment can be made smaller and lighter than the one in the embodiment of FIG. 1 .
[0025] A filter 34 is disposed at one end of the tube to allow ambient air to fill the volume of the tube as it expands under the action of the network of tubes 26 as it fills up with the compressed gas from the cylinder 6 . The filter 34 is designed to filter the ambient air during an emergency smoke situation and provide clear air to fill the volume of the tube 2 . The filter 8 is preferably a HEPA filter.
[0026] A closable port or opening 36 is provided to allow the air inside the network of tubes 26 to be exhausted when the tube 2 is deflated for stowage. The air within the tube 2 is exhausted through the filter 34 .
[0027] The filter 8 may also be integrated into the wall of the tube 2 in various ways. For example, a portion or the entire tube wall may be made of filter material. The entire wall of the tube 2 may also be made of filter material.
[0028] In operation, the lever 10 is operated in the conventional manner to release the content of the cylinder into the network of tubes 26 , thereby inflating the tube 26 into the form shown in FIG. 5 . The action of the network of tubes 26 taking on the expanded form as shown in FIG. 5 forces the tube 2 to also expand, since the tube 2 is attached to the network of tubes 26 . The expanding tube 2 draws in ambient air through the filter 34 to equalize the pressure between the interior and the outside of the tube 2 . Clear air then fills up the interior of the tube 2 . The user then positions the device R between the user and the source of information, such an instrument panel, allowing him to read the information in spite of the smoke that may have invaded the space. After use, the tube 2 and the network of tubes 26 are deflated by compressing the tube 2 , forcing the air inside through the filter 34 , and allowing the gas within the network of tubes 26 to exhaust through the port 36 .
[0029] The tube 2 may be disposed outside the network of tubes 26 , as long as it is attached thereto. The tube 2 and the network of tubes 26 may be made from the same material and integrated into one unit.
[0030] The device R is advantageously lightweight, since it is completely supported by pressurized gas, without any metallic framework, such as a helical spring.
[0031] While this invention has been described as having preferred design, it is understood that it is capable of further modification, uses and/or adaptations following in general the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features set forth, and fall within the scope of the invention or the limits of the appended claims. | An emergency vision device, comprises a collapsible tube made of airtight material and having an expanded form and a deflated stowage form; first and second clear members disposed at respective first and second ends of the tube to enable a user to see through the tube and observe a source of information at a distal end of the tube while smoke or other particulate matter is in the environment; and a portable gas cylinder having compressed clear gas and an outlet operably connected to the interior of the tube. The gas cylinder is operable to release the clear gas to fill the interior of the tube to expand the tube to the expanded form. | 0 |
PRIOR APPLICATION
This application is a U.S. national phase application based on International Application No. PCT/SE03/00786, filed 15 May 2003, claiming priority from Swedish Patent Application No. 02015121-1, filed 21 May 2002.
The present invention concerns a method for the continuous cooking of wood raw material in the form of sawdust for the production of cellulose pulp.
THE PRIOR ART
Sophisticated cooking methods have been developed for the conventional continuous cooking of wood raw material in the form of well-defined cut chips with a relatively small fraction of finely divided material.
These cooking methods normally comprise the initial heating of the chips by steam to a temperature of 80-120° C., after which the chips are formed into a slurry with cooking or impregnation fluid. Delignification of the chips takes place in several stages during the successive increase in temperature of the mixture to the final cooking temperature, normally 125-170° C.
Exchange and modification of the cooking fluid takes place both during the impregnation and during the delignification, and this requires the provision of efficient draining equipment with the associated withdrawal strainers, such that cooking fluid can be withdrawn and later replaced by other cooking fluid with a modified composition and/or at a different temperature. For example, a first impregnation fluid, known as black liquor impregnation, containing black liquor with a relatively high level of residual alkali (10-20 g/l) is often used, which is withdrawn when the impregnation has been completed, and is replaced with fresh cooking liquid containing fresh white liquor at levels of 80-170 g/l.
One such piece of well-established draining equipment is the top separator, which is usually arranged at the top of the digester, and which can separate the fluid in which the chips have been transported and with which they have been impregnated prior to the top separator. In this case, addition of new cooking fluid can be carried out at the outlet from the top separator. A top separator is usually not used at the top of the second digester in two-vessel hydraulic digesters.
This top separator allows the cooking to be divided into several phases, a preimpregnation before the digester and an initial establishment of the cooking fluid in the digester.
A relatively rapid consumption of alkali takes place during the initial phases of the cooking, and the concentration of alkali falls dramatically while the concentration of liberated organic material, primarily lignin, increases. Thus, the modification of the cooking fluid during the cooking is attempted such that the level of alkali is raised while the level of liberated organic material can be held at a reasonable level. This requires efficient withdrawal strainers also in the digester, where consumed cooking fluid can be withdrawn, with new cooking fluid or washing fluid being added through central pipes.
Pin chips and sawdust are normally regarded as waste products and are often burned in bark-burning furnaces. Special problems arise when cooking pin chips or sawdust since these wood raw materials contain a great deal of, or consist entirely of, finely divided wood raw material. These finely divided fractions can typically be constituted by fine matter with a particle size distribution that has a normal distribution around a diameter of 1-3 mm, which is less than one tenth of the normal chip size. In particular, serious problems arise during the cooking of sawdust when attempting to circulate and to withdraw cooking fluid through and from the bed of sawdust. There is a risk of strainers clogging, when these are used, after a very short time or during any slight disturbance in the process, and this can result in the necessity to interrupt the process in order to clean these strainers.
Cooking systems for the cooking of sawdust have been delivered in which the digester itself has been made without any strainers, and in which a strict concurrent flow is used for cooking in the digester, and in which the subsequent washing is carried out in a pressurised diffuser. This maintains the pressure of the pulp until the washing is complete.
Equipment known as an “asthma digester” has also been used when cooking sawdust. This drives the sawdust into the pocket of the sluice through a sluice feed using steam injection, to a steam phase in the upper part of the digester. The sound that is created when injecting the sawdust from the sluice feed is the reason for the characteristic name of the digester. Heating to the cooking temperature in this case takes place in the upper steam phase of the digester, through the external addition of hot steam, normally steam at an intermediate pressure, 6-12 bar. Examples of such asthma digesters are shown in Tappi's manual “Pulp and Paper Manufacture”, Volume 5, 1989, pp. 166-173. The asthma digester is shown in Tappi's manual with a countercurrent washing stage at the bottom of the digester, where washing filtrate is withdrawn using central pipes equipped with strainers. These pipes penetrate the digester from the bottom.
Document U.S. Pat. No. 6,325,888 reveals a system for the cooking of sawdust in which strainers have been completely removed from the digester itself, and in which the sawdust mixture is heated to its full cooking temperature, 250-350 F (equivalent to 121-176° C.), before being fed into the cooking vessel. In order for this heating to succeed with a low consumption of steam, thickening equipment and a steam mixer are used in series. The thickening equipment first drains the sawdust mixture to a consistency of 20%-40%, before the final heating to full cooking temperature takes place in the steam mixer, before input into the cooking vessel. Following cooking in the strainerless digester, the pulp is fed to a subsequent pressure diffuser where the pulp is washed free of precipitated organic material while its pressure is maintained.
This solution, however, requires well-functioning draining equipment for the sawdust mixture, which is difficult to drain, and this places stringent requirements on the strainers and their ability to withstand clogging. Furthermore, the system is expensive and complex, since a chip bin, a feed screw with steam pre-heating, a chip pump, draining equipment, a steam mixer, a cooking vessel and a final pressurised diffuser washer are all required. This equipment is often so expensive that the cost of investment cannot be justified by the revenue that the cooking of sawdust can generate, and this means that this wood raw material cannot be used for the production of cellulose pulp.
Cooking of sawdust usually gives a cellulose pulp with a lower quality, which is often used as bulking material or as a base component for simple paper products, and this means that investment costs are very restricted if it is to be possible in any way to justify a separate process for the cooking of sawdust. Furthermore, the process must be very stable, and processes that are prone to disturbance have often been closed down if they are not capable of giving continuous function.
Aim and Purpose of the Invention
The principal aim of the invention is to cook sawdust in a continuous process in which thickening stages are not required, and which can be carried out with a minimum of process equipment. The process in this way requires the smallest possible investment.
A second aim is to establish a continuous process for the cooking of sawdust in which the system maintains the mixture at a consistency lower than 15% and in which the sawdust, which has been formed into a slurry with cooking fluid, is in all essential stages carried in a unitary flow from the formation of the slurry in the first steaming vessel until the washing of the pulp after the cooking.
A further aim is to cook the chips using a method that uses energy efficiently. This is made possible since a major part of the cooking fluid is established directly with the washing filtrate that is expelled at high temperatures during the final diffusion wash. The washing filtrate can, in one preferred embodiment, be released from pressure, with the result that the temperature falls to approximately 100° C., and released steam is used for the heating of the sawdust, whereby the heat can be better conserved than would be the case if this washing filtrate were to exchange heat with fresh, cold cooking fluid.
DESCRIPTION OF DRAWING
FIG. 1 shows schematically an arrangement by means of which the method according to the invention can be realised.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a process according to the invention in which wood raw material in the form of sawdust is continuously cooked for the production of cellulose pulp.
It is appropriate that the sawdust is continuously fed to a cyclone by blowing, where air is separated upwards and the sawdust downwards to the top of a steaming vessel 2 at atmospheric pressure, preferably a steaming vessel that is open and that lacks sluices for the input of sawdust.
Steaming/heating of the sawdust with steam LP ST subsequently takes place in the steaming vessel 2 . It is appropriate that the steam is constituted by low-pressure steam at 4-6 bar pressure above atmospheric, which is freely available at the pulp mill, and it is appropriate that the steam is supplied to the steaming vessel through injection of steam to the sawdust through nozzles 3 passing through the wall of the steaming vessel at an injection level SL that lies above the level LL 1 of the cooking fluid while being below the level of the upper level CL 1 of the sawdust. The steam in one preferred embodiment is constituted at least partially by the steam obtained when releasing the pressure of a washing filtrate from a subsequent washing stage. Impregnation with cooking fluid at the bottom of the steaming vessel then starts, through the addition of warm cooking fluid at the bottom of the steaming vessel 2 for impregnation of the sawdust via nozzles 4 passing through the wall of the steaming vessel at a level FL that lies below the level SL of injection of steam and under the level LL 1 of cooking fluid that has been established in the steaming vessel.
A mixture of sawdust and cooking fluid is output from the bottom of the steaming vessel following impregnation with warm cooking fluid, once the sawdust, which has been mixed with cooking fluid, has been warmed in the steaming vessel to a temperature in the interval 80-110° C.
The mixture of sawdust and cooking fluid is pressurised by a pump P for transport onwards to the top of a cooking vessel 5 where a level CL 2 of the sawdust is established. This level lies above a level LL 2 of cooking fluid in the cooking vessel.
A conventional sluice feed 6 is shown in the arrangement shown in FIG. 1 , of the type having a high-pressure tap, and having through filling pockets that can be rotated from a filling position (shown with solid lines on the pocket) to an emptying position (shown with dashed lines on the pocket). The sawdust mixture can, when the sluice is in the filling position, flow through the pocket where the sawdust mixture expels the cooking fluid that is present in the pocket, and out to the pump P. This pump returns the expelled cooking fluid under pressure to a pocket that is in the emptying position. The high-pressure tap 6 provides good insulation between the pressurised part of the system and the part at atmospheric pressure, but it can be eliminated completely in a simple embodiment of the system, being replaced by one or two pumps arranged in series.
Only when the sawdust mixture has been carried to the cooking vessel is steam MP ST added to the top of the cooking vessel 5 such that the sawdust that lies above the level of the cooking fluid is heated to its full cooking temperature within the interval 130-160° C. in the steam phase of the cooking vessel. The level of cooking fluid in the cooking vessel is regulated by withdrawal of cooking fluid, appropriately from the bottom of the cooking vessel, preferably, as is shown, through a withdrawal strainer in the form of a pipe that penetrates upwards through the bottom of the digester, and which warm withdrawn fluid is, at least partially, returned to the steaming vessel as is shown in FIG. 1 .
The sawdust mixture before input to the cooking vessel maintains a temperature that is well below the cooking temperature in the cooking vessel, and that preferably lies at least 15° C., preferably at least 25-30° C., below the cooking temperature.
After warming of the sawdust in the steam phase to the full cooking temperature, cooking of the sawdust in the cooking fluid takes place while the sawdust falls, and the sawdust experiences a cooking time, i.e. a retention time in the cooking fluid, that lies in the interval 60-200 minutes.
After the completion of the cooking phase the sawdust mixture is fed to a pressurised diffusion washer 7 that expels cooking fluid from the sawdust using washing fluid TV while the pressure is maintained. The expelled cooking fluid forms a washing filtrate TF.
It is appropriate that the washing fluid that is used is constituted by filtrate from subsequent treatment stages, conventionally oxygen gas delignification, which washing fluid maintains a temperature of approximately 70-90° C. Following expulsion of the hot cooking fluid, which has a temperature of 130-160° C., a washing filtrate TF is obtained, which has an elevated temperature of approximately 120-145° C.
If the temperature of the pulp in the diffusion washer 7 is approximately 150° C., and if 12 m 3 of washing fluid at a temperature of 80° C. is used during washing to expel 10 m 3 of warm cooking fluid from the pulp (with no change in concentration), then the washing filtrate will be at a temperature of approximately 138° C. (10*150+2*80=12*X X=138).
This washing filtrate is led to the steaming vessel 2 where it is added to the sawdust at this elevated temperature. If required, the washing filtrate TF obtained can first be cooled, either in a heat exchanger 8 and/or through a release of pressure in a cyclone 8 b . The heat exchanger can be, as is shown in the figure, an indirect heat exchanger that is cooled by cold water.
In order to obtain a cooking process with a good energy economy, steam from the cyclone 8 b is used as heating steam in the steaming vessel 2 , and at least part of the total amount of washing filtrate from the diffuser 7 is led directly to the steaming vessel to form a part of the cooking fluid.
The washing filtrate TF constitutes a fraction of the total amount of cooking fluid in excess of 50%, and preferably in an amount equivalent to 3.5-6 tonnes, preferably approximately 5 tonnes, of washing filtrate per tonne of sawdust.
White liquor WL is added to the steaming vessel 2 and, where appropriate, also during pumping to the cooking vessel, in order to form part of the total cooking fluid. The amount of white liquor required is equivalent to 1-2.5 tonnes of white liquor per tonne of sawdust.
The complete addition of washing filtrate, white liquor and steam condensate allows the establishment of a fluid/wood ration (F/W) that has the following values at different locations in the system:
on exit from the steaming vessel F/W≧6.0 (equivalent to a concentration just over 16%) on input to the cooking vessel F/W≧7.0 (equivalent to a concentration just over 14%); on exit from the cooking vessel F/W≧6.0 (equivalent to a concentration just over 16%).
The calculation above is based on the original wood content, and since the pulp is delignified during the cooking and the released organic material (principally lignin) is withdrawn for recovery, the actual concentration on exit from the cooking vessel will be significantly lower (a concentration of 9.6% for a yield of 60% from the cooking phase).
This corresponds, at a fluid/wood ration of 7.0, to:
approximately 1 tonne condensate per tonne sawdust approximately 1 tonne white liquor per tonne sawdust approximately 5 tonnes washing filtrate (black liquor) per tonne sawdust.
The large amount of black liquor that is returned at an elevated temperature to the steaming vessel ensures a very good energy economy for the process, and essentially only the sawdust (usually having the temperature of the surroundings, 20° C.) and the white liquor (which, however, normally has a temperature of 70-85° C.) need to be heated.
The consistency of the sawdust, in a slurry formed with cooking fluid, is maintained during the complete process such that it does not exceed 20%, and it is appropriate that it is held at a maximum level in the interval 15%-17%. From the point of view of process technology, the low consistency ensures a system that is easy to manage with a minimum of interruptions of the process. A significant characteristic of the process is that more than 95%, and preferably 100%, of the cooking fluid that is added to the sawdust from the initial mixing with cooking fluid until it is transferred to the digester accompanies the sawdust in a mixture of cooking fluid and sawdust right up until the cooking is completed in the cooking vessel.
The invention can be modified in a number of ways within the framework of the accompanying claims. For example, a simple strainerless flow 11 can be used in the cooking vessel, where the cooking fluid and a small amount of accompanying sawdust can be returned to the top of the cooking vessel. Such a simple flow can be designed without restrictions that run the risk of becoming clogged, and, by arranging the outlet 12 to lie above the established upper surface of the sawdust, the returned cooking fluid and the sawdust can be distributed without restriction in the digester.
While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims. | The invention concerns a simplified method for the continuous cooking of wood raw material in the form of sawdust for the production of cellulose pulp, The method does not require any thickening stages and can be carried out with a minimum of process equipment. The complete process can be established with a steaming vessel, a cooking vessel and a subsequent pressure diffuser while the sawdust is mixed with the cooking fluid to form a slurry. The slurry has a consistency that throughout the process does not exceed 20%. The maximum consistency is preferably held at a maximum consistency of about 15-17%. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
This application is the National Phase application of International Application No. PCT/IB2011/050196, filed Jan. 17, 2011, which designates the United States and was published in English. The foregoing related application, in its entirety, is incorporated herein by reference.
TECHNICAL FIELD
The subject matter of the present invention is a new sulphated or phosphated lipidic compound, a composition comprising it and uses thereof, for example in the field of cosmetics, personal care products and dermopharmacy.
The present invention concerns the chemical, medical or cosmetical industries for the care of the skin and appendages (such as hair, eyelashes, eyebrows, nails, hairs) of mammals, animals or humans.
BACKGROUND ART
The cosmetics industry is constantly looking for new active compounds to propose for formulating new cosmetic products. Increasingly, compounds are sought which must be active on several targets to improve the overall condition of the skin, that is to say at first its degree of hydration, but also its mechanical properties and/or also its brightness. Also, a new active ingredient can be sought that is most specific, able to beautify the skin and appendages, such as by adding volume, clarifying the complexion, slimming, etc.
The object of the present invention is to meet this demand.
SUMMARY OF THE INVENTION
To this aim, a compound of the following developed formula I is proposed:
R 1 being a lipidic/lipophilic chain
X=PO(OH) 2 or SO 2 (OH)
n=1 to 4.
The present invention is therefore aiming the two following types of compounds:
The phosphated compounds having the following developed formula II:
The sulphated compounds having the following developed formula III:
According to the invention, a lipidic/lipophilic chain R 1 is recited as being R 1 =OR 2 or NR 3 R 4 .
R 2 is an alkyl, aryl, aralkyl, acyl, sulfonyl, sugar or alkoxy chain of 1 to 24 carbon atoms, preferably of at least 4 carbon atoms, linear, branched or cyclic, with or without substitutions, saturated or not, hydroxylated or not, sulfurated or not.
R 3 and R 4 are, independently from each other, either a hydrogen or a R 2 chain, namely an alkyl, aryl, aralkyl, acyl, sulfonyl, sugar or alkoxy chain of 1 to 24 carbon atoms, preferably of at least 4 carbon atoms, linear, branched or cyclic, with or without substitutions, saturated or not, hydroxylated or not, sulfurated or not, one of R 3 and R 4 being an R 2 type chain.
The compounds according to the present invention can be used in the form of salts or acids or a mixture of both depending on the pH of use.
In vitro and in vivo test results were obtained with the compounds according to the invention leading to a high potential of applications in cosmetics or dermopharmacy.
According to preferred features:
R 1 =OR 2 with R 2 =hydrocarbon chain having at least 4 carbon atoms and/or the compound of the invention is phosphated X being PO(OH) 2 and/or n=1
More preferably, the compound of the present invention is obtained from malic acid or from one of its derivatives or analogs as starting material.
Thus, a preferred compound according to the invention is the 2-phosphate-succinic-acid-4-tetradecyle ester having the following developed formula IV and called thereafter in the text the <<Lipo-Phosphomalate>>:
with n=1, X=PO(OH) 2 and R 1 =OC 14 H 29 .
The use of the malic acid as one of the starting materials leads advantageously to a manufacture process that is simple and presenting a height yield as described below.
Other commercial diacids are advantageously suitable to obtain the compound of the invention, for example tartaric acid (the 2,3-dihydroxybutanedioic acid) of following developed formula V:
According to further features:
The compound can comprise a substitution on the —(CH 2 ) n -chain, for example chosen among OH, NH 2 or an alkyl chain; preferably a lower alkyl chain and/or The carbonyl function can be replaced by a double bound analog function as disclosed in the following developed formula VI:
And/or the COOH carboxylic acid function of the compound of the invention can be present in a derivated form, for example an ester form.
Advantageously, the compound of the invention can be coupled with any peptide of m aminoacids Xaa with m from 1 to 10 for obtaining a compound of the following developed formula VII, the coupling being achieved through a peptidic type bond with the COOH of the compound according to the invention:
And/or with one OH of the X substituent.
The compound of the invention becomes thus a phosphated or sulfated alternative to the classical lipidic chains coupled to peptides, like a palmitoyle, elaidoyle or biotinoyle chain, the lipidic or lipophyle R1 having the function to improve the bioavailability of the peptide and its cutaneous penetration ability.
The invention encompasses peptides (Xaa) m consisting of encoded, natural or unnatural, derivatives and analogs amino acids (coded aminoacids: Alanine A Ala, Arginine R Arg, Asparagine N Asn, Aspartate ou aspartic acid D Asp, Cystein, C Cys, Glutamate ou glutamic acid E Glu, Glutamine Q Gln, Glycine G Gly, Histidine H His, Isoleucine I Ile, Leucine L Leu, Lysine K Lys, Methionine M Met, Phenylalanine F Phe, Proline P Pro, Serine S Ser, Threonine T Thr, Tryptophane W Trp, Tyrosine Y Tyr, Valine, V Val). Are cited for example, without being restrictive, the aminoacids K, T, C, M, MO (methionine whose sulfur is oxydated), MO 2 (methionine whose sulfur is dioxydated sulfur), the dipeptides KT, KC, KP, VW, KK, TT, YR, NF, DF, EL, CL, AH, YR, carnitine, the tripeptides RKR, HGG, GHK, GKH, GGH, GHG, KFK, GKH, KPK, KMOK, KMO2K, KAvaK, the tetrapeptides RSRK (SEQ ID NO:1), GQPR (SEQ ID NO:2) or KTFK (SEQ ID NO:3), the pentapeptides KTTKS (SEQ ID NO:4), the hexapeptides GKTTKS (SEQ ID NO:5), VGVAPG (SEQ ID NO:6), etc.
As for other example, the aminoacid sequences of the following marketed peptides can be mentioned as well: Vialox™, Syn-ake™ or Syn-Coll™ (Pentapharm), Hydroxyprolisilane CN™ (Exsymol), Argireline™, Leuphasyl™, Aldenine™, Trylgen™, Eyeseryl™, Serilesine™ or Decorinyl™ (Lipotec), Collaxyl™ or Quintescine™ (Vincience), BONT-L-Peptide™ (Infinitec Activos), Cytokinol™LS (Laboratoires Serobiologiques/Cognis), Kollaren™, IP2000™ or Meliprene™ (Institut Europeen de Biologie Cellulaire), Neutrazen™ (Innovations), ECM-Protect™ (Atrium Innovations), Timp-Peptide™ or ECM Moduline™ (Infinitec Activos), as well as the peptides mentioned thereafter in the text.
Beyond ten amino acids, derivatives or analogs of amino acids, the peptides are generally too bulky for cosmetic applications and too expensive to manufacture. For these reasons, the coupled peptide is preferably limited to n=6 (hexapeptide).
It is also possible that the compound according to the invention be a bis-lipo sulphated or bis- or tri phosphated. The following developed formula VIII illustrates this characteristic of the invention as for example for a compound according to the invention that is bis-lipo phosphated:
The compound of the present invention can be represented by the following general formula IX incorporating all the possible variants disclosed above:
Wherein:
X=PO(OH) 2 ; SO 2 (OH); PO(OH)(Xaa) m or SO 2 (Xaa) m ;
A=H; OH; NH 2 or akyl (1-6C);
n=1 to 4;
Y=—CO—OR 2 ; —CO—NR 3 R 4 ; —O—CO—R 2 ; —C═CR 2 ;
R 2 =an alkyl, aryl, aralkyl, acyl, sulfonyl, sugar or alkoxy chain of 1 to 24 carbon atoms, linear, branched or cyclic, with or without substitutions, saturated or not, hydroxylated or not, sulfurated or not; preferably a chain of at least 4 carbons;
R 3 and R 4 are, independently from each other, either a hydrogen atom or a R 2 chain;
R 5 =OH, O-alk (1-6C), (Xaa) m , NH 2 or NH-alkyl(1-6C);
Xaa=peptide of m aminoacids Xaa with m from 1 to 10.
In the developed formula I,
X=PO(OH) 2 or SO 2 (OH)
R 5 =OH
A=H
n=1 to 4,
Y=—CO—R 1 with R 1 =OR 2 or NR 3 R 4 .
The object of the present invention is also a topical composition, cosmetic or dermopharmaceutical, characterized in that it comprises the compound as recited above in a physiologically acceptable medium, the use of this composition in cosmetic or dermopharmacy to improve the general condition of the skin, for example to treat the intrinsic and extrinsic cutaneous signs of ageing, to treat skin sagging, to improve the tonicity, firmness, elasticity of skin, to treat cutaneous atrophy, to improve the density of the dermis and epidermis, to treat cutaneous dehydration, to treat hair loss, to stimulate the expansion of adipose tissues, to lighten the skin, for treating glycation of molecules in the skin, to treat acne, to treat skin degradation due to the effects of oxidation and to treat inflammatory conditions.
Therefore, applications can be offered in ranges including moisturizers, cleansers, anti-aging, antioxidant, protective, restorative (hands, feet, lips), outlines (face, eyes, neck, lips), makeup care for the skin and its appendages, including eyelashes, lip products, solar products, remodeling, plumping, refiling (eg of the hands, bust, breasts), hair care, etc.
More particularly, in-vitro and in-vivo test results given in the detailed description show that the composition is useful for preventing or treating the cutaneous signs of ageing, preventing or treating cutaneous dehydration, for improving the suppleness of skin, for treating the loss of firmness, for treating fine lines and wrinkles, for stimulating the expansion of adipose tissue and for lightening the skin.
According to other advantageous features, the cosmetic or dermopharmaceutical composition of the invention may incorporate one or more additional active ingredients, to provide advantageously a cosmetic or dermo-pharmaceutical product with a wider range of properties or to enhance the properties of the compounds of the present invention. Additional active ingredients may for example be selected from the lightening, anti-redness, sunscreens, moisturizing, humectants, exfoliating, anti-aging, anti-wrinkle and fine lines, stimulating the collagen and/or elastin synthesis, volumizing, elastic properties improving, anti-acne, anti-inflammatory, anti-oxidants, anti-free radical, or propigmenting depigmenting agents, depilatories, anti-regrowth or promoting the growth agents, peptides, vitamins etc. These active ingredients may be obtained from plant materials such as plant extracts or products from plant cells culture or fermentation.
More specifically, the compound of the invention can be combined with at least one of compounds selected from compounds of vitamin B3, niacinamide compounds like or tocopherol, retinol, hexamidine, α-lipoic acid, resveratrol or DHEA or N-acetyl-Tyr-Arg-O-hexadecyl, Pal-VGVAPG (SEQ ID NO:7), Pal-KTTKS (SEQ ID NO:8), Pal-GHK, Pal-KMO2K and Pal-GQPR (SEQ ID NO:9) peptides, which are active ingredients used in conventional cosmetic or dermopharmaceutical topical compositions.
DETAILED DESCRIPTION
The term “physiological medium” means according to the present invention, without limitation, an aqueous or alcoholic solution, a water-in-oil emulsion, an oil-in-water emulsion, a microemulsion, an aqueous gel, an anhydrous gel, a serum, a dispersion of vesicles.
“Physiologically acceptable” means that the disclosed compositions or compounds are suitable for use in contact with mucous membranes, nails, scalp, hairs, hair and skin of mammals and more particularly human without risk of toxicity of incompatibility, instability, allergic response, and others.
When present in a composition, the compound of the invention is present in amounts ranging from 0.000001% to 15% compared to the total weight of the composition, more preferably between 0.0001% and 5%, depending of the destination of the composition and the desired effect more or less pronounced.
All percentages and ratios used herein are by weight of total composition and all measurements are made at 25° C. unless it is specified otherwise.
Typically, in a composition of the invention consisting simply of the compound of the invention and of an excipient (the physiologically medium) used as solubilizer, for example, forming an “active ingredient” for the future preparation of a cosmetic composition, the amount of the compound will be comprised between 0.00005% and 0.05%.
The choice of the excipient of the composition is made according to the constraints related to the compounds of the invention (stability, solubility, etc.) and if according to the dosage form then considered for the composition.
The compounds of the invention have solubility in water that varies according to their exact chemical nature. Thus the compounds of the invention can be incorporated into compositions using an aqueous solution, and those that are not soluble in water can be solubilized with cosmetically, pharmaceutically or physiologically acceptable conventional solubilizers, for example and without limiting this list: ethanol, propanol, isopropanol, propylene glycol, glycerin, butylene glycol, or polyethylene glycol or any combination. It may also be interesting to dissolve the compounds of the invention using emulsifiers and for example emulsifiers containing phosphorus such as phosphate esters.
Additional Ingredients
The CTFA International cosmetic ingredient dictionary & handbook (13th Ed. 2010) (published by the Cosmetic, Toiletry, and Fragrance Association, Inc., Washington, D.C.) describes a non limited wide variety of cosmetic and pharmaceutical ingredients usually used in the skin care industry that can be used as additional ingredients in the compositions of the present invention. Examples of these ingredient classes include, but are not limited to: healing agents, skin anti-aging agents, anti-wrinkle agents, anti-atrophy agents, skin moisturizing agents, skin smoothing agents, antibacterial agents, pesticides anti parasitic agents, antifungal agents, fungicidal agents, fungistatic agents, bactericidal agents, bacteriostatic agents, antimicrobial agents, anti-inflammatory agents, anti-pruriginous agents, external anesthetic agents, antiviral agents, keratolytic agents, free radicals scavengers, antiseborrheic agents, antidandruff agents, the agents modulating the differentiation, proliferation or pigmentation of the skin and agents accelerating penetration, desquamating agents, melanin synthesis stimulating or inhibiting agents, whitening or depigmenting agents, propigmenting agents, self-tanning agents, NO-synthase inhibiting agents, antioxidants, free radical scavengers and/or agents against atmospheric pollution, reactive carbonyl species scavengers, antiglycation agents, tightening agents, agents stimulating the synthesis of dermal or epidermal macromolecules and/or capable of inhibiting or preventing their degradation, such as for example collagen synthesis-stimulating agents, elastin synthesis-stimulating agents, decorin synthesis-stimulating agents, laminin synthesis-stimulating agents, defensin synthesis-stimulating agents, chaperone synthesis-stimulating agents, aquaporin synthesisstimulation agents, hyaluronic acid synthesis-stimulating agents, fibronectin synthesisstimulating agents, sirtuin synthesis-stimulating agents, agents stimulating the synthesis of lipids and components of the stratum corneum (ceramides, fatty acids, etc.), agents that inhibit collagen degradation, other agents that inhibit elastin degradation, agents that inhibit serine proteases such cathepsin G, agents stimulating fibroblast proliferation, agents stimulating keratinocyte proliferation, agents stimulating adipocyte proliferation, agents stimulating melanocyte proliferation, agents stimulating keratinocyte differentiation, agents stimulating adipocyte differentiation, agents that inhibit acetylcholinesterase, skin relaxant agents, glycosaminoglycan synthesis-stimulating agents, antihyperkeratosis agents, comedolytic agents, antipsoriasis agents, DNA repair agents, DNA protecting agents, stabilizers, anti-itching agents, agents for the treatment and/or care of sensitive skin, firming agents, anti-stretch mark agents, binding agents, agents regulating sebum production, lipolytic agents or agents stimulating lipolysis, anti-cellulite agents, antiperspirant agents, agents stimulating healing, coadjuvant healing agents, agents stimulating reepithelialization, coadjuvant reepithelialization agents, cytokine growth factors, calming agents, anti-inflammatory agents, anesthetic agents, agents acting on capillary circulation and/or microcirculation, agents stimulating angiogenesis, agents that inhibit vascular permeability, venotonic agents, agents acting on cell metabolism, agents to improve dermal-epidermal junction, agents inducing hair growth, hair growth inhibiting or retardant agents, muscle relaxants; antipollution and/or anti-free radical agents; lipolytic agents, venotonic agents, slimming agents, anticellulite agents, agents acting on the microcirculation; agents acting on the energy metabolism of the cells; cleaning agents, hair conditioning agents, hair styling agents, hair growth promoters, sunscreen and/or sunblock compounds, make-up agents, detergents, pharmaceutical drugs, emulsifiers, emollients, antiseptic agents, deodorant actives, dermatologically acceptable carriers, surfactants, abrasives, absorbents, aesthetic components such as fragrances, colorings/colorants, essential oils, skin sensates, cosmetic astringents, anti-acne agents, anti-caking agents, anti foaming agents, antioxidants, binders, biological additives, enzymes, enzymatic inhibitors, enzyme-inducing agents, coenzymes, chelating agents, plant extracts, plant derivatives, plant tissue extracts, plant seed extracts, plant oils, botanicals, botanical extracts, essential oils, marine extracts, agents obtained from a biofermentation process, mineral salts, cell extracts and sunscreens (organic or mineral photoprotective agents active against ultraviolet A and/or B rays), ceramides, peptides, buffering agents, bulking agents, chelating agents, chemical additives, colorants, cosmetic biocides, denaturants, drug astringents, external analgesics, film formers or materials, e.g., polymers, for aiding the film-forming properties and substantivity of the composition, quaternary derivatives, agents increasing the substantivity, opacifying agents, pH adjusters, propellants, reducing agents, sequestrants, skin bleaching and lightening agents, skin tanning agents, skin-conditioning agents (e.g., humectants, including miscellaneous and occlusive), skin soothing and/or healing agents and derivatives, skin treating agents, thickeners, and vitamins and derivatives thereof, peeling agents, moisturizing agents, curative agents, lignans, preservatives, UV absorbers, a cytotoxic, an antineoplastic agent, a fat-soluble active, suspending agents, viscosity modifiers, dyes, nonvolatile solvents, diluents, pearlescent aids, foam boosters, a vaccine, and their mixture.
The additional ingredient can be selected from the group consisting of sugar amines, glucosamine, D-glucosamine, N-acetyl glucosamine, N-acetyl-D-glucosamine, mannosamine, N-acetyl mannosamine, galactosamine, N-acetyl galactosamine, vitamin B3 and its derivatives, niacinamide, sodium dehydroacetate, dehydroacetic acid and its salts, phytosterols, salicylic acid compounds, hexamidines, dialkanoyl hydroxyproline compounds, soy extracts and derivatives, equol, isoflavones, flavonoids, phytantriol, farnesol, geraniol, peptides and their derivatives, di-, tri-, tetra-, penta-, and hexapeptides and their derivatives, KTTKS (SEQ ID NO:4), PalKTTKS (SEQ ID NO:8), carnosine, N-acyl amino acid compounds, retinoids, retinyl propionate, retinol, retinyl palmitate, retinyl acetate, retinal, retinoic acid, water-soluble vitamins, ascorbates, vitamin C, ascorbic acid, ascorbyl glucoside, ascorbyl palmitate, magnesium ascorbyl phosphate, sodium ascorbyl phosphate, vitamins their salts and derivatives, provitamins and their salts and derivatives, ethyl panthenol, vitamin B, vitamin B derivatives, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin K, vitamin K derivatives, pantothenic acid and its derivatives, pantothenyl ethyl ether, panthenol and its derivatives, dexpanthenol, biotin, amino acids and their salts and derivatives, water soluble amino acids, asparagine, alanine, indole, glutamic acid, water insoluble vitamins, vitamin A, vitamin E, vitamin F, vitamin D, mono-, di-, and tri-terpenoids, beta-ionol, cedrol, and their derivatives, water insoluble amino acids, tyrosine, tryptamine, butylated hydroxytoluene, butylated hydroxyanisole, allantoin, tocopherol nicotinate, tocopherol, tocopherol esters, pal-GHK, phytosterol, hydroxy acids, glycolic acid, lactic acid, lactobionic acid, keto acids, pyruvic acid, phytic acid, lysophosphatidic acid, stilbenes, cinnamates, resveratrol, kinetin, zeatin, dimethylaminoethanol, natural peptides, soy peptides, salts of sugar acids, Mn gluconate, Zn gluconate, particulate materials, pigment materials, natural colors, piroctone olamine, 3,4,4′-trichlorocarbanilide, triclocarban, zinc pyrithione, hydroquinone, kojic acid, ascorbic acid, magnesium ascorbyl phosphate, ascorbyl glucoside, pyridoxine, aloe vera, terpene alcohols, allantoin, bisabolol, dipotassium glycyrrhizinate, glycerol acid, sorbitol acid, pentaerythritol acid, pyrrolidone acid and its salts, dihydroxyacetone, erythrulose, glyceraldehyde, tartaraldehyde, clove oil, menthol, camphor, eucalyptus oil, eugenol, menthyl lactate, witch hazel distillate, eicosene and vinyl pyrrolidone copolymers, iodopropyl butylcarbamate, a polysaccharide, an essential fatty acid, salicylate, glycyrrhetinic acid, carotenoïdes, ceramides and pseudo-ceramides, a lipid complex, oils in general of natural origin such shea butter, apricot oil, onagre oil, prunus oil, palm oil, monoi oil, HEPES, procysteine, O-octanoyl-6-D-maltose, the disodium salt of methylglycinediacetic acid, steroids such as diosgenin and derivatives of DHEA, DHEA or dehydroepiandrosterone and/or a precursor or chemical or biological derivative, N-ethyloxycarbonyl-4-para-aminophenol, bilberry extracts; phytohormones; extracts of the yeast Saccharomyces cerevisiae , extracts of algae, extracts of soyabean, lupin, maize and/or pea, alverine and its salts, in particular alverine citrate, extract of butcher's broom and of horse chestnut, and mixtures thereof, a metallopreoteinase inhibitor. Further skin care and hair care active ingredients that are particularly useful can be found in SEDERMA commercial literature and on the website www.sederma.fr.
In any embodiment of the present invention, however, the additional ingredients useful herein can be categorized by the benefit they provide or by their postulated mode of action. However, it is to be understood that the additional ingredients useful herein can in some instances provide more than one benefit or operate via more than one mode of action. Therefore, classifications herein are made for the sake of convenience and are not intended to limit the additional ingredients to that particular application or applications listed.
The following known actives can be mentioned, as examples: betain, glycerol, Actimoist Bio 2™ (Active organics), AquaCacteen™ (Mibelle AG Cosmetics), Aquaphyline™ (Silab), AquaregulK™ (Solabia), Carciline™ (Greentech), Codiavelane™ (Biotech Marine), Dermaflux™ (Arch Chemicals, Inc), Hydra′Flow™ (Sochibo), Hydromoist L™ (Symrise), RenovHyal™ (Soliance), Seamoss™ (Biotech Marine), Essenskin™ (Sederma), Moist 24™ (Sederma), Argireline™ (trade name of the acetyl hexapeptide-3 of Lipotec), spilanthol or an extract of Acmella oleracea known under the name Gatuline Expression™ (EP 1722864), an extract of Boswellia serrata known under the name Boswellin™, Deepaline PVB™ (Seppic), Syn-AKE™ (Pentapharm), Ameliox™, Bioxilift™ (Silab) or mixtures thereof
Among other plant extracts which can be combined with the compound of the invention, there may more particularly be mentioned extracts of Ivy, in particular English Ivy ( Hedera Helix ), of Chinese thorowax ( Bupleurum chinensis ), of Bupleurum Falcatum , of arnica ( Arnica Montana L), of rosemary ( Rosmarinus officinalis N), of marigold ( Calendula officinalis ), of sage ( Salvia officinalis L), of ginseng ( Panax ginseng ), of ginko biloba, of St.-John's-Wort ( Hyperycum Perforatum ), of butcher's-broom ( Ruscus aculeatus L), of European meadowsweet ( Filipendula ulmaria L), of big-flowered Jarva tea ( Orthosiphon Stamincus Benth), of algae ( Fucus Vesiculosus ), of birch ( Betula alba ), of green tea, of cola nuts ( Cola Nipida ), of horse-chestnut, of bamboo, of spadeleaf ( Centella asiatica ), of heather, of fucus, of willow, of mouse-ear, of escine, of cangzhu, of chrysanthellum indicum , of the plants of the Armeniacea genus, Atractylodis Platicodon, Sinnomenum, Pharbitidis, Flemingia , of Coleus such as C. Forskohlii, C. blumei, C. esquirolii, C. scutellaroides, C. xanthantus and C. Barbatus , such as the extract of root of Coleus barbatus , extracts of Ballote , of Guioa , of Davallia , of Terminalia , of Barringtonia , of Trema , of antirobia, cecropia, argania, dioscoreae such as Dioscorea opposita or Mexican, extracts of Ammi visnaga , of Centella asiatica and Siegesbeckia , in particular Siegesbeckia orientalis , vegetable extracts of the family of Ericaceae, in particular bilberry extracts ( Vaccinium angustifollium ) or Arctostaphylos uva ursi, aloe vera , plant sterols (e.g., phytosterol), Manjistha (extracted from plants in the genus Rubia , particularly Rubia Cordifolia ), and Guggal (extracted from plants in the genus Commiphora , particularly Commiphora Mukul ), kola extract, chamomile, red clover extract, Piper methysticum extract ( Kava Kava from SEDERMA (FR 2 771 002 and WO 99/25369), Bacopa monieri extract (Bacocalmine™ from SEDERMA, WO 99/40897) and sea whip extract, extracts of Glycyrrhiza glabra , of mulberry, of melaleuca (tea tree), of Larrea divaricata , of Rabdosia rubescens , of euglena gracilis , of Fibraurea recisa Hirudinea , of Chaparral Sorghum , of sun flower extract, of Enantia chlorantha , of Mitracarpe of Spermacocea genus, of Buchu barosma , of Lawsonia inermis L., of Adiantium Capillus - Veneris L., of Chelidonium majus , of Luffa cylindrical , of Japanese Mandarin ( Citrus reticulata Blanco var. unshiu ), of Camelia sinensis , of Imperata cylindrical , of Glaucium Flavum , of Cupressus Sempervirens , of Polygonatum multiflorum , of loveyly hemsleya , of Sambucus Nigra , of Phaseolus lunatus , of Centaurium , of Macrocystis Pyrifera , of Turnera Diffusa , of Anemarrhena asphodeloides , of Portulaca pilosa , of Humulus lupulus , of Coffea Arabica and of Ilex Paraguariensis.
Extraction from the plant may be performed using conventional engineerings such as phenolic extraction, from any part of the plant such as the flower, seed, fruit, root, tubercle, leaf, pericarp and preferably rhizome. The extraction solvents may be selected from amongst water, propylene glycol, butylene glycol, glycerine, PEG-6 caprylic/capric glycerides, polyethylene glycol, methyl and/or ethyl esters, diglycols, cyclical polyols, ethoxylated or propoxylated diglycols, alcohols (methanol, ethanol, propanol, and butanol) or any mixture of these solvents. Plant extracts according to the present invention may also be obtained by other processes such as maceration, simple decoction, lixiviation, reflux extraction, super-critical extraction with CO 2 , ultrasound or microwave extraction or counter-current techniques, or by plant cell culture engineerings and/or fermentation. This list is not restrictive.
Suitable peptides can include, but are not limited to, di-, tri-, tetra-, penta-, and hexa-peptides and derivatives thereof In one embodiment, the composition comprises from about 1×10-7% to about 20%, more preferably from about 1×10-6% to about 10%, even more preferably from about 1×10-5% to about 5%, by weight of additional peptide.
As used herein, “peptide” refers to peptides containing ten or fewer amino acids and their derivatives, isomers, and complexes with other species such as metal ions (e.g., copper, zinc, manganese, magnesium, and the like). As used herein, peptide refers to both naturally occurring and synthesized peptides. Also useful herein are naturally occurring and commercially available compositions that contain peptides.
Suitable dipeptides for use herein include but are not limited to Carnosine (beta-AH), YR, VW, NF, DF, KT, KC, CK, KP, KK or TT. Suitable tripeptides for use herein include, but are not limited to RKR, HGG, GHK, GKH, GGH, GHG, KFK, GKH, KPK, KMOK, KMO2K or KAvaK. Suitable tetrapeptides for use herein include but are not limited to RSRK (SEQ ID NO:1), GQPR (SEQ ID NO:2) or KTFK (SEQ ID NO:3). Suitable pentapeptides include, but are not limited to KTTKS (SEQ ID NO:4). Suitable hexapeptides include but are not limited to GKTTKS (SEQ ID NO:5), VGVAPG (SEQ ID NO:6) and of the type disclosed in FR 2854897 and US 2004/0120918.
Other suitable peptides for use herein include, but are not limited to lipophilic derivatives of peptides, preferably palmitoyl derivatives, and metal complexes of the aforementioned (e.g., copper complex of the tripeptide His-Gly-Gly). Preferred dipeptide derivatives include N-Palmitoyl-beta-Ala-His, N-Acetyl-Tyr-Arg-hexadecylester (CALMOSENSINE™ from SEDERMA, France, WO 9807744, U.S. Pat. No. 6,372,717). Preferred tripeptide derivatives include N-Palmitoyl-Gly-Lys-His, (Pal-GKH from SEDERMA, France, WO 0040611), Pal-KMO2K, a copper derivative of His-Gly-Gly sold commercially as lamin, from Sigma, lipospondin (N-Elaidoyl-Lys-Phe-Lys) and its analogs of conservative substitution, N-Acetyl-Arg-Lys-Arg-NH2 (Peptide CK+), N-Biot-Gly-His-Lys (N-Biot-GHK from SEDERMA, WO0058347) and derivatives thereof Suitable tetrapeptide derivatives for use herein include, but are not limited to N-palmitoyl-Gly-Gln-Pro-Arg (SEQ ID NO:9) (from SEDERMA, France), suitable pentapeptide derivatives for use herein include, but are not limited to N-Palmitoyl-Lys-Thr-Thr-Lys-Ser (SEQ ID NO:8) (available as MATRIXYL™ from SEDERMA, France, WO 0015188 and U.S. Pat. No. 6,620,419) N-Palmitoyl-Tyr-Gly-Gly-Phe-X with X Met (SEQ ID NO:10) or Leu (SEQ ID NO:11) or mixtures thereof Suitable hexapeptide derivatives for use herein include, but are not limited to N-Palmitoyl-Val-Gly-Val-Ala-Pro-Gly (SEQ ID NO:7) and derivatives thereof.
The preferred compositions commercially available containing a tripeptide or a derivative include Biopeptide-CL™ by SEDERMA (WO0143701), Maxilip™ by SEDERMA (WO 0143701), Biobustyl™ by SEDERMA. The compositions commercially available preferred sources of tetrapeptides include RIGIN™ (WO0043417), EYELISS™ (WO03068141), MATRIXYL™ RELOADED, and MATRIXYL 3000™ which contain between 50 and 500 ppm of palmitoyl-Gly-Gln-Pro-Arg (SEQ ID NO:9), and carrier, proposed by SEDERMA, France (US2004/0132667). The following marketed peptides can be mentioned as well as additional active ingredients: Vialox™, Syn-ake™ or Syn-Coll™ (Pentapharm), Hydroxyprolisilane CN™ (Exsymol), Argireline™, Leuphasyl™, Aldenine™, Trylgen™, Eyeseryl™, Serilesine™ or Decorinyl™ (Lipotec), Collaxyl™ or Quintescine™ (Vincience), BONT-L-Peptide™ (lnfinitec Activos), Cytokinol™LS (Laboratoires Serobiologiques/Cognis), Kollaren™, IP2000™ or Meliprene™ (Institut Européen de Biologie Cellulaire), Neutrazen™ (Innovations), ECM-Protect™ (Atrium Innovations), Timp-Peptide™ or ECM Moduline™ (lnfinitec Activos),
Composition Preparation
The compositions of the present invention are generally prepared by conventional methods such as are known in the art of making topical and oral compositions and compositions for injection. Such methods can typically be conducted in one or more steps, with or without heating, cooling, and the like.
The physical form of the compositions according to the invention is not important: they may be in any galenic form such creams, lotions, milk or cream ointments, gels, emulsions, dispersions, solutions, suspensions, cleansers, foundations, anhydrous preparations (sticks, in particular lipbalm, body and bath oils), shower and bath gels, shampoos and scalp treatment lotions, cream or lotion for care of skin or hair, make-up removing lotions or creams, sun-screen lotions, milks or creams, artificial suntan lotions, creams or milks, pre-shave, shave or aftershave creams, foams, gels or lotions, make-up, lipsticks, mascaras or nail varnishes, skin “essences,” serums, adhesive or absorbent materials, transdermal patches, or powders, emollient lotion, milk or cream, sprays, oils for the body and the bath, foundation tint bases, pomade, emulsion, colloid, compact or solid suspension, pencil, sprayable or brossable formulation, blush, red, eyeliner, lipliner, lip gloss, facial or body powder, styling foams or gels, nail conditioner, lip balms, skin conditioners, moisturizers, hair sprays, soaps, body exfoliants, astringents, depilatories and permanent waving solutions, antidandruff formulations, anti-sweat and antiperspirant compositions, nose sprays and so on. These compositions can also be presented in the form of lipsticks intended to apply colour or to protect the lips from cracking, or of make-up products for the eyes or tints and tint bases for the face. Compositions in accordance with the invention include cosmetics, personal care products and pharmaceutical preparations. The present invention may also be applied on animal skin and/or appendages. One can also consider a composition in the shape of foam or in the form of compositions for aerosol also including a propellant agent under pressure.
Cosmetic compositions according to the invention may also be for orodental use, for example, toothpaste. In that case, the compositions may contain the usual adjuvants and additives for compositions for oral use and, in particular, surfactants, thickening agents, moisturizing agents, polishing agents such as silica, various active substances such as fluorides, particularly sodium fluoride, and, possibly, sweetening agents such as saccharin sodium.
The compound according to the present invention may be in the form of solution, dispersion, emulsion, paste, or powder, individually or as a premix or in vehicles individually or as a premix in vectors such as macro-, micro-, or nanocapsules, macro-, micro- or, nanospheres, liposomes, oleosomes or chylomicrons, macro-, micro-, or nanoparticles or macro-, micro or nanosponges, spores or exines, micro or nano emulsions or adsorbed on organic polymer powders, talcs, bentonites, or other inorganic or organic supports.
The compound according to the present invention may be used in any form whatsoever, in a form bound to or incorporated in or absorbed in or adsorbed on macro-, micro-, and nanoparticles, or macro-, micro-, and nanocapsules, for the treatment of textiles, natural or synthetic fibres, wools, and any materials that may be used for clothing or underwear for day or night intended to come into contact with the skin, handkerchiefs or cloths, to exert their cosmetic effect via this skin/textile contact and to permit continuous topical delivery.
Method of Topical Cosmetic or Dermopharmaceutical Treatment
The present invention also concerns a topical treatment process to improve the general condition of the skin involving topical application to the skin of an effective amount of the composition of the invention as recited above. More specifically:
to prevent and/or treat the signs of intrinsic and extrinsic skin ageing; to prevent and/or treat skin dehydration; to prevent and/or treat skin sagging and/or improve tone and/or firmness and/or elasticity and/suppleness of the skin; to prevent and/or treat skin atrophy and/or improve the density of the dermis and epidermis; to give or return volume to the dermis and epidermis; for stimulating the expansion of adipose tissue. to lighten the skin; to prevent and/or treat skin roughness; to prevent and/or treat degradation of the skin due to the effects of oxidation; to prevent and/or treat hair loss; to prevent and/or treat glycation of molecules in the skin; to prevent and/or treat acne; to prevent and/or treat inflammatory states.
The composition according to the invention may be applied locally onto areas of the face, lips, neck, neckline, hands, feet, head or body. One of the major advantages of the present invention resides in the ability whenever necessary or desirable to be able to apply local selective “gentle” treatments through this topical, non-invasive method of application. In the case of anti-wrinkle use for example it may be applied very locally using a syringe or micro-canula.
It is also possible, however, to consider a composition containing the compound according to the invention intended to be injected subcutaneously.
According to other specific features the treatment method according to the invention can be combined with one or more other treatment methods targeting the skin such as luminotherapy, aromatherapy or heat treatments.
According to the invention, devices with several compartments or kits may be proposed to apply the method described above which may include for example and non-restrictively, a first compartment containing a composition including the invention lipo-sulphated or lipo-phosphated compound, and in a second compartment a composition containing another active ingredient and/or excipient, the compositions contained in the said first and second compartments in this case being considered to be a combination composition for simultaneous, separate or stepwise use in time, particularly in one of the treatment methods recited above.
EXAMPLES
The following examples describe and demonstrate various aspects within the scope of the present invention. The examples are only given for illustrative purposes and should not be considered to be restrictive to this invention. Additionally for illustrative purposes several cosmetic formulations will be described. These formulations are representative of but do not restrict the invention.
1/Example of Manufacture Method for Obtaining the Lipo-Phosphomalate (Ester 4-tetradecyle of the 2-phosphate-succinic acid) According to the Invention
The synthesis of the 2-phosphate-succinic acid 4-tetradecyl ester (final product with the 2 reference) is realized in 4 linear steps according to the following synthesis schema:
Synthesis of the (2,2-dimethyl-5-oxo-[1,3]dioxolan-4-yl)-acetic acid (With the 5 Reference on the Above Schema)
Marketed DL-malic acid (with the 4 reference on the above schema) is protected in the dioxolane form in toluene reflux, in the presence of 2,2-dimethoxypropane. The reaction is quantitative. The obtained product (with the 5 reference in the above schema) is directly engaged in the following step.
Synthesis of (2,2-Dimethyl-5-oxo-[1,3]dioxolan-4-yl)-acetic acid tetradecyl ester (With the 7 Reference in the Above Schema)
The free carboxylic function is esterified with 1-tetradecanol, in the presence of DCC (Dicyclohexylcarbodiimide) and of a catalytic amount of DMAP3 (4-dimethylaminopyridine). The obtained compound (with the 7 reference in the above schema) is directly engaged in the following step.
Synthesis of the Succinic acid 4-tetradecyl ester (With the 8 Reference in the Above Schema)
The cetal (ref 7) is hydrolyzed in an acid medium to conduct to the acid. The isolated product yield is of 71% after purification and cristallisation in cyclohexane.
Synthesis of the 2-Phosphate-succinic acid 4-tetradecyl ester (Ref 2)
The free alcohol function is phosphated with phosphoric acid in the presence of a catalytic amount of dibutyltin dilaurate, at 80° C. The desired lipo-phospho-malate (ref 2) is obtained with a 46% yield in the form of a white solid.
2/Formulation Example of an Active Ingredient Comprising the Invention Compound
This active ingredient is for the cosmetic industry for the preparation of cosmetic products, such as creams, gels, etc.
The solid Lipo-Phosphomalate is first solubized in a mixture of sugar esters (laurate and/or oleate sorbitan) and of phosphated esters (oleyl and/or dioleyl phosphates), then dispersed in an emollient. Typically, the amount of Lipo-Phosphomalate in this active ingredient will be of about 200 ppm.
3/In Vitro Evaluation Results
For theses evaluation tests, when the Lipo-Phosphomalate is solubilized, it is according to the above point 2/.
Filaggrin is a protein found in the upper part of the epidermis. It is a key factor in water homeostasis by virtue of its crucial role in forming and then stabilizing the cutaneous barrier (stratum corneum), and in crating the Natural Moisterising Factor (NMF).
Filaggrin is produced by the granular layer—the last viable of the epidermis—in the form of a polymeric precursor: the profilaggrin. The latter is a chain of 1 to 12 filaggrin monomers. Its phosphorylation rate controls its insolubility, lysis and packing in kertohyalin granules with loricrine and keratins 1 and 10.
Successively and, as it will rise towards the upper layers of the epidermis, profilaggrin will undergo:
a proteolysis leading to the production of monomers of filaggrin. Matriptase is involved in this proteolysis; a binding on the keratin intermediate filaments (KIF) thanks to TGase; the de-imination of filaggrin by a peptidyl deiminase to reduce the binding and leading to the reappearance of filaggrin monomers, and the degradation of filaggrin into filaggrin fragments by an unidentified protease.
In the lower part of the stratum corneum, dehydration triggers the complete proteolysis of filaggrin fragments under the action of caspase-14. This proteolysis leads to the production of hygroscopic amino acids. These amino acids form about 40% of the natural moisturizing factor (NMF), partly responsible for the maintenance of good hydration of the epidermis.
Good hydration of the epidermis is a complex phenomenon involving maintaining a high level of expression of different proteins: filaggrin, TGase, loricrine, matriptase and caspase 14. This is achieved through the application on human keratinocytes in culture or on skin explants.
Proper hydration of the skin is also ensured by the presence at the horny layer of a particularly impermeable lipid membrane, which prevents water loss.
3.1—Study of Filaggrin Synthesis on Human Keratinocytes (Immunofluorescent Method)
Protocol: Human keratinocytes were cultivated up to confluence. The cells were then placed in contact/not contact with the solubilized Lipo-Phosphomalate for 21 days. At the end of this contact period, labelling common to both filaggrin and profilaggrin was carried out on cell layers using specific antibodies. Labelling intensity was analysed on photos (n=15 photos) and compared to that obtained for the negative control and for vitamin D3 at 10 −7 M used as a positive differentiation control.
TABLE 1
Production of filaggrine and profilaggrin in human keratinocytes
in the presence of solubilised Lipo-Phosphomalate
Filaggrin/
profilaggrin
Change (%);
Concentration
(UFA/10 6 cell.)
significance
Control
—
1.39 ± 0.62
Reference
Solubilised
1.5 ppm
3.04 ± 1.21
+119%; p < 0.01
Lipo-
5 ppm
5.00 ± 1.58
+259%; p < 0.01
Phosphomalate
Vitamin D3 (10 −7 M): +221% (p < 0.01)
The positive control used strongly induced profilaggrin and filaggrin synthesis in cells. At the same time, increasing concentrations of the solubilised Lipo-Phosphomalate stimulated this production in a dose-dependent manner. An increase of +259% (p<0.01) was recorded in the presence of 5 ppm of solubilised Lipo-Phosphomalate compared to control.
3.2—Highlighting of the Increase of Filaggrin/Profilaggrin Synthesis in Explanted Human Skin in the Presence of Solubilised Lipo-Phosphomalate
The filaggrin/profilaggrin synthesis has been confirmed in explanted human skins. This model, highly realistic, corroborates the results obtained on single layer cultures.
Experimental Protocol:
The day after their preparation (removal from adipose tissue), a cream containing 5 ppm of solubilised Lipo-Phosphomalate was topically applied to skin segments measuring 8 mm in diameter, every day for 5 days (cream prepared with the active ingredient of point above 2/) (n=3 skin segments). At the same time the placebo cream was applied to control skins (n=3). Following applications, the skin segments were fixed, frozen and then cut using a cryomicrotome. The slides obtained were labelled with the same antibody as before. The fluorescent filaggrin/profilaggrin markers obtained for the cream with the Lipo-Phosphomalate were quantified by image analysis (n=30 photos for each case) and compared to those obtained with the placebo cream.
In a second series of experiments, the skin segments were lightly stripped in advance (4 successive strips), in order to improve the active penetration, and then are subjected to the same procedure as before.
Results:
The photos show the variation in the quantity of filaggrin/profilaggrin in the upper section of the human skin epidermis following application of the cream containing the solubilised Lipo-Phosphomalate or the placebo cream.
TABLE 2
Production of filaggrin and profilaggrin induced
by the Lipo-Phosphomalate by human skin
Filaggrin/profilaggrin
Change (%);
(UFA)
significance
Intact
Placebo cream
8.59 ± 2.00
Reference
skins
Cream with 5 ppm
11.40 ± 2.90
+33%; p < 0.01
of solubilised Lipo-
Phosphomalate
Stripped
Placebo cream
8.55 ± 1.70
Reference
skins
Cream with 5 ppm
14.43 ± 3. 10
+69%; p < 0.01
of solubilised Lipo-
Phosphomalate
A marked increase in the filagrin fluorescent signal was observed in the skins that had received the cream at 5 ppm of solubilised Lipo-Phosphomalate compared to the skins that had received the placebo cream.
Similarly, the results of the analysis recorded for the stripped skin show that the cream containing 5 ppm of solubilised Lipo-Phosphomalate stimulates filaggrin/profilaggrin production to a highly significant extent compared to the control. It is interesting to note that the same quantity of filaggrin was obtained with the placebo, regardless of whether or not the strips were used. The stripping before compound application therefore improved the efficacy of the solubilised Lipo-Phosphomalate facilitating its penetration.
These two studies, together with the one realised on the cultured keratinocytes, show that the solubilised Lipo-Phosphomalate can increase the quantities of filaggrin/profilaggrin in the epidermis.
3.3—Study of the Synthesis of Caspase-14 and Matriptase
These two enzymes are responsible of the metabolism of pro-filaggrin and filaggrin.
The method disclosed in example 1.2- was used.
Results
TABLE 3
Production of matriptase and caspase-14 in the presence of solubilised Lipo-Phosphomalate
in cultured human keratinocytes by immunolabelling (n = 15 photos)
Matriptase
Change (%);
Caspase
Change (%);
Concentrations
(UFA/10 6 cell.)
significance
(UFA/10 6 cell.)
significance
Control
—
1.01 ± 0.34
Reference
0.51 ± 0.16
Reference
Solubilised
1.5 ppm
2.27 ± 0.47
+125%; p < 0.01
1.13 ± 0.44
+121%; p < 0.01
Lipo-
5 ppm
4.08 ± 1.56
+304%; p < 0.01
1.68 ± 0.64
+229%; p < 0.01
Phosphomalate
Vitamin D3 (10 −7 M): +239% and +571% (p < 0.01)
The results show that the matriptase increases in a similar pattern to filaggrin in the layers of keratinocytes. Induction was significant and dose-dependent on the quantity of solubilised Lipo-Phosphomalate to reach +304% at 5 ppm.
Induction of caspase-14 synthesis (+229%; p<0.01) was also noted with 5 ppm of solubilised Lipo-Phosphomalate. As for the matriptase, a parallelism with the increase of filaggrin synthesis is noted.
It appears therefore that filaggrin formation is not the only phenomenon to be promoted by the solubilised Lipo-Phosphomalate, but that the enzymes, which produce the wetting component on cleaving filaggrin, are also stimulated, and in similar proportions.
3.4—Study of the Synthesis of Loricrine
Loricrine is one of the key elements in the formation of the corneal envelope. It is attached to involucrin (see 1.1) by transglutaminase, which forms rigid, insoluble structures. The method described in 1.2. was used.
TABLE 4
Production of loricrin in the presence of solubilised
Lipo-Phosphomalate in cultured human keratinocytes
by immunolabelling (n = 15 photos)
Loricrin
Change (%);
Concentrations
(UFA/10 6 cell.)
significance
Control
—
0.73 ± 0.48
Reference
Solubilised
1.5 ppm
1.69 ± 0.67
+131%; p < 0.01
Lipo-
5 ppm
3.84 ± 1.19
+426%; p < 0.01
Phosphomalate
Vitamin D3 (10 −7 M): +206% (p < 0.01)
As for the three preceeding proteins, a highly stimulation of the synthesis of loricrin by the solubilised Lipo-Phosphomalate is also observed.
3.5—Study of the Transcription and Activity of Transglutaminase
Transglutaminase was studied using the transcription by m-RNA, qRT-PCR and regarding activity by enzymological assay.
ByqRT-PCR: Human keratinocytes were placed in contact/not placed in contact with solubilised for 14 days. At the end of the contact period, the cultures were stopped and m-RNA allowing production of transglutaminase-1 protein was quantified using the RT-PCR method.
After extraction and purification of the m-RNA, copies are made in DNA using a Reverse Transcriptase (RT). The number of copies of a given m-RNA (here that of TGase) is thereafter amplified using two oligonucleotides (called primers) specific to the gene of TGase and to an enzyme (PCR=polymerase chain reaction) during a series of amplification cycles, each of which doubling the number of copies present. The result of this amplication is measured by fluorescence. Ct is the number of cycles required to achieve a given fluorescence level (arbitrarily set). It is clear, that the more m-RNA of a given gene present in the starting culture there are, the fewer cycles (Ct) are needed to reach the set level of fluorescence.
By Enzymology:
At the end of the 14-day contact period, the cells were placed in contact with a fluorescent synthetic transglutaminase substrate. Metabolisation of the substrate via transglutaminase will allow the fixation in the intracellular protein matrix. After rinsing, the non fixed fluorescent substrate is eliminated and the fluorescence fixed in the cells by the enzyme is quantified.
TABLE 5
Production of transglutaminase-1 m-RNA and of the variation of transglutaminase activity
in the presence of solubilised Lipo-Phosphomalate in the keratinocytes (n = 5)
m-RNA
Enzymology
Concen-
Number of
% change**;
Transglutaminase
% Change;
trations
cycles: Ct*
Significance
(UFA/10 6 cell.)
Significance
Control
—
24.60 ± 0.42
Reference
230 ± 43
Reference
Solubilised
5 ppm
23.25 ± 0.46
+101%; p < 0.01
516 ± 63
+124%; p < 0.01
Lipo-
Phosphomalate
Vitamin D3 (10 −7 M): m-RNA +73% and Enzymology ×7.5 (p < 0.01)
*One Ct unit corresponds to approximately 100% variation.
**After normalisation by the housekeeping gene, invariable in concentration, with or without solubilised Lipo-Phosphomalate.
These results show that transglutaminase is induced by the solubilised Lipo-Phosphomalate, both at transcriptional level (m-RNA) and at the protein activity level. In both cases, the increase is close to +100% (p<0.01).
In addition, a DNA-Array study has shown that the transglutaminase-1 and involucrin genes are over-expressed in the network with other genes essential for the formation of the corinfied layer in the presence of solubilised Lipo-Phosphomalate.
Induction of TGase synthesis by the solubilised Lipo-Phosphomalate completes this picture of the stimulation of the protein essential to form the skin barrier. What is remarkable in the invention is the simultaneous stimulation in the presence of solubilised Lipo-Phosphomalate of these five proteins, each essential for hydration.
3.6—Evaluation of the Effect of the Lipo-Phosphomalate on Complex Lipids Synthesis
The skin is made up of several layers of cells protecting us from external agressions by various means. The main mean among them is a lipid barrier in the stratum corneum, the outermost layer of skin, consisting mainly of ceramides, cholesterol and fatty acids allowing the skin to retain its hydration. We studied the effect of Lipo-Phosphomalate on the synthesis of cholesterol and ceramides in cultured human keratinocytes.
Cholesterol (Immunolabelling)
Cultured human keratinocytes at confluence were placed in contact with the Lipo-Phosphomalate in a medium slightly enriched with calcium to promote the establishment of intercellular junctions and thus improve the anchorage of differentiated cells to the underlying cells. A negative control was carried out in the same medium. After a 7-day contact period, the layer was labeled with a cholesterol-specific fluorescent. The intensity of the labeling was analysed on the photos and compared to that obtained with the negative control (Table 6).
Photos of the Lipo-Phosphomalate cases show the onset of marked differentiation visible beneath the microscope. The cells are linked in large cohesive bundles, sometimes interlinked as though via a network. This was not observed with the negative control over the same period.
In addition to quantification by immunological labeling, cholesterol quantification was carried out using high-performance thin-layer chromatography (or HPTLC).
Cholesterol (Thin-Layer Chromatography)
The same protocol was followed as before but a larger quantity of keratinocyes was used on this occasion because of the limits of detection of the apparatus. After 7 days, the layers were rinsed, lipids extracted using solvents before being deposited on a thin-layer chromatography plate using an automated device. After migration and detection, the bands were analysed and quantified based on a range of standard lipids deposited on the same plate.
TABLE 6
Variation of the quantity of cholesterol by immunolabelling and HPTLC
in keratinocytes after contact with solubilised Lipo-Phosphomalate
IMF
HPTLC
Cholesterol
% Change*;
Cholesterol
% Change;
Concentrations
(UFA/10 6 cell.)
Significance
(pg/10 6 cell.)
Significance
Control
—
2.40 ± 2.37
Reference
20.24 ± 2.40
Reference
Solulbilised
5 ppm
4.98 ± 2.59
+107%; p < 0.04
30.89 ± 7.20
+53%; p < 0.05
Lipo-
Phosphomalate
These two results, obtained with two different methods, show that the Lipo-Phosphomalate stimulate the production of cholesterol during keratinocyte differenciation.
Ceramides
At the same time as the HPTLC cholesterol assay, an assay of hydroxylated and non-hydroxylated ceramides was carried out on the extracts.
TABLE 7
Variation of the quantity of ceramides by HPTLC in the keratinocytes
after contact with the solubilised Lipo-Phosphomalate
Non
hydroxylated
Hydroxylated
Ceramides
% Change*;
Ceramides
Change*;
Concentrations
(pg/10 6 cell.)
Significance
(pg/10 5 cell.)
Significance
Control
—
2.36 ± 0.10
Reference
1.40 ± 0.01
Reference
Solubilised
5 ppm
8.41 ± 1.30
+256%; p < 0.01
10.50 ± 1.12
×7.5
Lipo-
Phosphomalate
*number of times.
These data clearly show that the Lipo-Phosphomalate induces the production of chorlesterol and of various classes of ceramides in keratinocytes during their differentiation. This lipid production by the Lipo-Phosphomalate was not observed in fibroblasts or melanocytes. It is therefore a specific effect related to the metabolism of keratinocyte during its differentiation.
All this information clearly shows that the Lipo-Phosphomalate triggers in cultured human keratinocytes the production of the elements essential for the introduction and homeostasis of hydration and skin barrier. Thus a number of syntheses converge to create the cornified cell envelope in terms of both the production of corneocyte gorged with a crosslinked protein matrix and the production of its essential lipids. Filaggrine, caspase-14 and matriptase form the basiss of the production of water homiostatis; involucrin, loricrine and transglutaminase are the key elements of the corneocyte formation; ceramides and cholesterol complete this picture for the formation of the hydro-lipid barrier.
3.7—Synthesis of Hyaluronic Acid and its Receptor CD44
The cited main interest of hyaluronic acid is its role as a moisturizer agent for the skin epidermis and also as anti-wrinkle agent, because participating to the elasticity of the skin. Hyaluronic acid is present in the intercellular spaces of the basal and spineous layers, mainly of the medium spineous layer, but absent from the upper layers (granular and horny). Its hydration role is therefore positioned at the lower layers of the epidermis, unlike the previously mentioned effects that were located in the upper layers of the epidermis.
Effect on the Synthesis of Hyaluronic Acid by Human Keratinocytes Humains
Protocol: Human keratinocytes are humains were cultivated in MW24 plates for 24 h. Cells were contacted or not with the Lipo-Phosphomalate for 3 days. Culture surpernatants were taken and an assay of the quantity of hyaluronic acid was achieved. Retinoic acid was used as the positive control.
TABLE 8
Increase of the hyaluronic acid by the Lipo-Phosphomalate
on human keratinocytes (ELISA) (n = 5)
Concentration
ng/10 e 6 cells
% Change/control
Control
—
878 +/− 21
Reference
Solubilised
1.67 ppm
1015 +/− 46
+16%; p < 0.01
Lipo-
5 ppm
1374 +/− 50
+57%; p < 0.01
Phosphomalate
8.33 ppm
1480 +/− 51
+69%; p < 0.01
Retinoic acid (positive control) 1 μM = +190%; p < 0.01.
A dose-dependent and significant stimulation of the synthesis of hyaluronic acid in the human keratinocyte in the presence of the Lipo-Phosphomalate of the invention is observed.
Effect of the CD44 Synthesis for the Keratinocyte
Protocol:
Human keratinocytes were cultivitated in 35 mm box to confluence. Cells are contacted or not with the Lipo-Phosphomalate for 22 days. At the end of this contact period, the cells are fixed and an immunological labeling of the CD44 is made using specific antibodies.
TABLE 9
Increase of the CD44 synthesis in the presence of
the Lipo-Phosphomalate by human keratinocytes
UFA/10 6
% Variation/
Concentration
cells
control
Control
—
3.96 +/− 3.65
Reference
Solubilized
5 ppm
27.20 +/− 16.5
+587%; p <
Lipo-
0.01 => ×7
Phosphomalate
A dose dependent and significant stimulation of the keratinocyte CD44 in the presence of the Lipo-Phosphomalate of the invention is observed.
3.8—Effect on the Laminin Synthesis by Human Keratinocytes
The laminin molecule is important at the level of the dermo-epidermal junction (DEJ). It ensures proper anchoring of basal keratinocytes to the basement membrane and is responsible for the suppleness of the epidermis. In aged cells it is no longer replaced as efficiently as in young cells, hence the need to stimulate the biosynthesis for an improved renewal.
Protocol:
Human keratinocytes are humains were cultivated in MW24 plates for 24 h. Cells were contacted or not with the Lipo-Phosphomalate for 3 days. Culture surpernatants were taken and an assay of the quantity of laminin was achieved. TGF-β1 was used as the positive control.
TABLE 10A
Increase of the laminin by the Lipo-Phosphomalate
on human keratinocytes (ELISA) (n = 5)
Concentration
ng/10 e 6cells
% Variation/control
Control
—
116 +/−13
Reference
Solubilized Lipo-
1.67 ppm
190 +/− 11
+64%; p < 0.01
Phosphomalate
5 ppm
333 +/− 10
+187%; p < 0.01
8.33 ppm
343 +/− 10
+196%; p < 0.01
TGF- β1 (positive control) 10 −6 % = +361%; p < 0.01
A dose dependent and significant stimulation of the laminin synthesis in the keratinocyte in the presence of the Lipo-Phosphomalate of the invention is observed.
This makes the Lipo-Phosphomalate of the invention particularly well suited for anti-aging, in particular for anti-wrinkles and firming applications.
3.9—Synthesis of Collagen I on Human Dermal Fibroblast
Normal human fibroblasts (NHF) are cultivated in MW24 plates for 24 hours. The cells are contacted or not with the Lipo-Phosphomalate of the invention at various concentrations for 7 days. The synthesis of collagen I produced by the cells is then quantified by immunolabeling fixed on the layers using a specific antibody. Quantification by image analysis is then performed on the photos. TGF-β1 is used as positive control.
An analysis of variance was performed on the data (cases treated compared with untreated cases). In the case of identity of variances, a Student't test was then performed on the means.
Results:
TABLE 10B
Increased synthesis of collagen I in
the fibroblast (n = 15 files/cases)
Concentration
AFU mean
% Variation/control
Contrôle
—
3.7 +/− 2.1
Reference
Solubilized
Eq 1%
8.1 +/− 5.6
+60%;
p = 0.09
Lipo-
Eq 3%
21.1 +/− 13.8
+315%;
p < 0.01
Phosphomalate
Eq 5%
30.4 +/− 14.6
+496%;
p < 0.01
TGF- β1
10 −6 %
55 +/− 17.6
+1374%;
p < 0.01
AFU=arbitrary fluorescen unit
A dose-dependent and significant stimulation of the synthesis of collagen I in the dermal fibroblasts in the presence of Lipo-Phosphomalate according to the invention is observed.
This makes the Lipo-Phosphomalate of the invention particularly well suited for preventing and repairing skin damages, comprising loss of the mechanical properties of the skin (loss of firmness), fine lines and wrinkles.
3.10—Study of the Lipo-Phosphomalate on Adipogenesis
Some cosmetic compounds are designed to encourage the installation of the subcutaneous fat for better aesthetics and greater volume. In this perspective, increase adipocyte differentiation was considered in in vitro tests, (with the key marker G3PDH) on pre-adipocyte cultures and, similarly, lipogenesis stimulation in these cultures was considered.
Effect of the Lipo-Phosphomalate on G3PDH Activity
Protocol:
3T3-L1 cells were cultivated until sub-confluence, then induced to differentiate with the appropriate mixture with or without the Lipo-Phosphomalate at different concentrations. After 3 days of incubation, the differenciation mixture is replaced by a new maintaining culture medium, in the presence or not of the Lipo-Phosphomalate. After 3 days of incubation, the cell layers are collected and the activity of G3PDH is assayed.
TABLE 11
Concentration
% Change/control
Control
—
Reference
Lipo-
10 ppm
+158%; p < 0.01
Phosphomalate
15 ppm
+225%; p < 0.01
Pioglytazone (positive control) 10 μM: +593%; p < 0.01
The results show that the differenciation of the pre-adipocytes is dose dependent and significantly stimulated by the Lipo-Phosphomalate.
Effect of the Lipo-Phosphomalate on the Synthesis of Triglycerides
Protocol:
3T3-L1 cells were cultivated until sub-confluence, then induced to differentiate with the appropriate mixture with or without the Lipo-Phosphomalate at different concentrations. After 3 days of incubation, the differenciation mixture is replaced by a new maintaining culture medium, in the presence or not of the Lipo-Phosphomalate. After 3 days of incubation, the quantity of intracellular triglycerides is measured by enzymatic method.
TABLE 12
Concentration
% Change/control
Control
—
Reference
Lipo-
10 ppm
+112%; p < 0.01
Phosphomalate
15 ppm
+210%; p < 0.01
Pioglytazone (positive control) 10 μM: +174%; p < 0.01
Stimulation of the Lipid Incorporation by the 3T3-L1 Cells
Protocol:
3T3-L1 cells are sowed and cultivated for 4 days (multiplication). Follow a differentiation phase (incubation with a classic differentiation mixture) and then a maturation phase (with a maturation mixture) in the presence or not of the Lipo-Phosphomalate at different concentrations. At the end of this period, cells were washed, fixed and coloured with oil red. The cell layers were photographed digitally and the red color is quantified by image analysis. The surface percentages of red oil, reported in the table below, were established compared to untreated control cells, and the test validated by comparison to pioglytazone (10 μM), positive control for stimulation of differentiation.
TABLE 13
Concentration
% Change/control
Control
—
Reference
Lipo-
10 ppm
+171%; p < 0.01
Phosphomalate
15 ppm
+294%; p < 0.01
20 ppm
+481%; p < 0.01
Pioglytazone (positive control) 10 μM: +323%; p < 0.01
The results show that the Lipo-Phosphomalate is dose dependently stimulating the differentiation and sysnthesis of triglycerides on pre-adipocytes. The Lipo-Phosphomalate can promote body volume by a cosmetic lipofilling-like effect.
3.11—Melanogenesis Study
Protocol:
Human melanocyte are sowed and contacted with the Lipo-Phosphomalonate for 5 days. At the end of the incubation period, the residual tyrosinase activity was measured in cell homogenates.
TABLE 14
Change in the tyrosinase activity of human melanocytes
after 5 days of contact with the Lipo-Phosphomalonate
Concentration
Variation (%)
Control
—
Reference
Lipo-
10 ppm
−21%; p < 0.01
Phosphomalate
12 ppm
−28%; p < 0.01
15 ppm
−31%; p < 0.01
Arbutin (positive control) 0.03% = −45%; p < 0.01
A significant and dose-dependent decrease of the tyrosinase activity is observed in the presence of the Lipo-Phosphomalate.
The Lipo-Phosphomalate of the invention is therefore useful for lightening the skin
All these results show that the Lipo-Phosphomalate of the present invention is an agent able to act on different levels: hydration, mechanical properties (firmness, suppleness), fines lines and wrinkles, give or return volume of the dermis, depigmentation of age spots . . . . The compound of the invention can be preconized for one these properties or as a global anti-ageing agent.
4/Galenic
The active ingredient described in point 1/ above (containing about 200 ppm of the Lipo-Phosphomalate) is used below to formulate cosmetic products.
4.1/Hydration Gel
Product
%
CTFA name
Phase A
H 2 O
Qsp100
Water
Ultrez 10 Carbopol
0.20
Carbomer
Phase B
Butylene glycol
2.00
Butylene glycol
Preservative
qs
Phase C
Cithrol GMS A/S NA
1.00
Glyceryl stearate &
PEG 100 stearate
Crodacol CS 90
0.50
Cetearyl Alcohol
Crodamol AB
2.00
C12-15 Alkyl Benzoate
Crodamol OSU
3.00
Dioctyl succinate
Phase D
Pemulen TR2
0.20
Acrylates/C10-30 Alkyl
Acrylates cross polymer
Crodamol STS
1.00
PPG-3 Benzyl Ether Myristate
DC 245
1.00
Cyclopentasiloxane
Phase E
Potassium sorbate
0.10
Potassium Sorbate
Phase F
Active ingredient
3.00
comprising 200 ppm of
Lipo-Phosphomalate of
the invention
Phase G
H 2 O
4.00
NaOH 30%
0.40
Sodium Hydroxide
Operating Procedure:
Stage 1: Weigh phase A and allow it to swell without stirring for 30 min
Stage 2: Weigh phase B and mix thoroughly.
Stage 3: Then add phase B into phase A, mix thoroughly.
Stage 4: Heat phase A+B at 75° C. in a water bath.
Stage 5: Weigh phase C and heat at 75° C. in a water bath. Mix thoroughly.
Stage 6: Weigh phase D and mix thoroughly.
Stage 7: Add phase C, then phase D in phase A+B with stirring staro v=1000 rpm, homogenise well.
Stage 8: extemporaneously, add phase E, pre-warmed to 60° C.
Stage 9: Then add phase F, homogenise thoroughly.
Stage 10: Around 55° C. add Phase G, homogenise thoroughly.
4.2/Hydration Cream
Product
%
CTFA name
Phase A
H 2 O
qsp100
Water
Ultrez 10
0.25
Carbomer
Phase B
Butylene glycol
2.00
Butylene glycol
Phenoxyethanol
qs
Phenoxyethanol
Phase C
Volpo S2
0.40
Steareth-2
Volpo S 10
1.20
Steareth-10
Cithrol GMS AS/NA
1.00
Glyceryl stearate &
PEG-100 stearate
Crodacol CS90
0.50
Cetearyl Alcohol
Laurocapram
2.50
Azone
DC 345
2.00
Cyclohexasiloxane &
Cyclopentasiloxane
Crodamol OSU
7.00
Dioctyl Succinate
Phase D
Active ingredient
3.00
comprising 200 ppm of
Lipo-Phosphomalate of
the invention
Phase E
Potassium sorbate
0.10
Potassium Sorbate
Phase F
H 2 O
3.00
Water
NaoH 30%
0.25
Sodium Hydroxide
Operating Procedure:
Stage 1: Weigh phase A and allow it to swell without stirring for 30 min
Stage 2: Heat phase A at 75° C. in a water bath.
Stage 3: Weigh phase B and mix thoroughly.
Stage 4: Then add phase B in phase A at 75° C. in a water bath.
Stage 5: Weigh phase C and heat at 75° C. in a water bath. Mix thoroughly.
Stage 6: Add phase C in phase A+B with stirring staro v=1000 rpm, homogenise thoroughly.
Stage 7: extemporaneously, add phase D, pre-warmed to 60° C.
Stage 8: Then add phase E, homogenise thoroughly.
Stage 9: Adjust the pH to 6 with phase E below 350 C.
Stage 10: Then add phase F, homogenise thoroughly.
4.3/Hydration/anti-ageing cream: a combination of the Lipo-Phosphomalate compound according to the invention, in particular for its hydration properties, and of the Essenskin® active marketed by the Applicant for its anti-ageing properties. Essenskin® will consolidate the anti-ageing properties of the compound of the present invention.
Essenskin® is an association of calcium α-hydroxymethionine and homotaurine.
Product
%
CTFA name
Phase A
H 2 O
qsp100
Water
Optasens G 83
0.30
Carbomer
Phase B
Arlatone LC
4.00
Sorbitan stearate &
sorbityl laurate
Phase C
Glycerin
5.00
Glycerin
Phenoxyethanol
qs
Phenoxyethanol
Phase D
Crodacol CS 50
0.50
Cetearyl alcohol
Estol 3609
3.00
Triethylhexanoin
Prisorine 2021
3.00
Isopropyl Isostearate
Dow Corning 345
2.00
Cyclohexasiloxane &
cyclopentasiloxane
Phase E
Active ingredient
3.00
comprising 200 ppm of
Lipo-Phosphomalate of
the invention
Phase F
Potassium sorbate
0.10
Potassium Sorbate
Phase G
H 2 O
3.00
Water
NaOH 30%
0.25
Sodium hydroxide
Phase H
Essenskin ®
2.50
Phase I
Verveine fragrance
0.10
Fragrance
Operating Procedure:
Stage 1: Sprinkle Ultrez 10 in water and allow it to swell for 30 min
Stage 2: Heat phase A at 75° C. in a water bath.
Stage 3: Weigh phase B and mix thoroughly. Sprinkle phase B in phase A, in a water bath at 75° C., with stirring v=300 rpm. Allow it to homogenize 30 minutes.
Stage 4: Weigh and mix phase C. Add phase C in phase A+B in a water bath at 75° C.
Stage 5: Weigh phase D and heat at 75° C. in a water bath.
Stage 6: Add phase E in phase D.
Stage 7: Poor phase D+E in phase A+B+C, with stirring v=1000 rpm, outside the waterbath.
Stage 8: Extemporaneously add phase F.
Stage 9: Slowling neutralise with phase G by adjusting the pH, allow it to swell for 1 hour.
Stage 10: Below 35° C., check the pH=+1-6.00.
Stage 11: Add phase H in the preceeding phase, mix thoroughly.
Stage 12: Add phase I in the preceeding phase, mix thoroughly.
4.4/Firming/Hydration Anti-Ageing Cream:
a combination of the compound of the invention, in particular for its hydration properties and of the Idealift® active marketed by the Applicant for its firming/anti-sagging properties.
Idealift® contains the lipodipeptide N-acetyl-Tyrosyl-Arginyl-O-hexadecyl ester. It is an active able to stimulate the synthesis of elastic fibers and has an anti-gravity effect on the face skin. The lipopeptide is also known for its calming and myorelaxing properties.
Product
%
CTFA name
Phase A
Optasens G83
0.30
Carbomer
H 2 O
qsp100
Water
Phase B
Phenoxyethanol
qs
Phenoxyethanol
Glycerin
3.50
Glycerin
Phase C
Optasens G82
0.20
Acrylic acid/Alkyl-
methacrylate copolymer
Polawax GP 200
1.00
Cetearyl alcohol &
polysorbate 20
Crodacol CS 90
1.00
Cetearyl alcohol
Crodamol STS
1.00
PPG-3 Benzyl Ether Myristate
DC 200 5 cps
2.50
Dimethicone
Crodamol TN
1.50
Isotridecyl Isononanoate
Phase D
Active ingredient
3.00
/
comprising 200 ppm of
Lipo-Phosphomalate of
the invention
Phase E
Idealift ®
4.00
/
Phase F
Potassium sorbate
0.10
Potassium Sorbate
Phase G
NaOH 30%
0.40
Sodium hydroxide
H 2 O
4.00
Water
Phase H
Orchid perfume
0.10
Fragrance
Operating Procedure:
Stage 1: Disperse the carbomer in water with stirring staro v=300 rpm. Allow it to swell 1 hour.
Stage 2: Mix phase B.
Stage 3: Then add phase B in phase A. Homogenise. Heat in a water bath at 75° C.
Stage 4: Weigh phase C, mix and heat at 75° C. in the water bath.
Stage 5: Add phase D in the preceeding phase.
Stage 6: Add phase E in phase A+B.
Stage 7: Add phase C+D in phase A+B+E, with stirring staro v=300 rpm.
Stage 8: Then add phase F in the preceeding phase, with stirring staro v=300 rpm. Allow it to hoogenise 1 hour.
Stage 9: Neutralise with phase G with stirring staro v=500 rpm around 50° C.
Stage 10: Then add phase H around 55° C., homogenise thoroughly.
5/In Vivo Evaluation Results on Hydration
Principle:
Studies to demonstrate the in-vivo efficacy of the Lipo-Phosphomalate compound of the invention were carried out on two subject panels: a female panel and a male panel.
Several complementary methods were associated during this study:
Study of the improvement in skin hydration by stimulating the synthesis of natural wetting agents: Corneometer® and Moisturemeter-D™; Study of the remanant effect after one week. Evaluation of the improvement of the homeostatis of the protective barrier by measuring transepidermal water loss (TEWL) on the Vapometer® and by the monitoring of the wetting power. Evaluation of the improvement in the water homeostasis process via the assay of caspase-14 and glycerol. Ex-vivo method on adhesives.
Protocol:
Inclusion and Exclusion Criteria Specific to the Study:
Women and men with dry skin or skin prone to dryness were included. The women had to present constant hormone levels for 3 months preceding the test and during the test. Only cosmetic products provided during the study were to be used. The application of treatments was, therefore, prohibited two weeks before the study and for the duration of the study.
Types of Studies and Duration:
Two studies were conducted under single-blind using non-invasive methods vs. a placebo site; each volunteer thus acted as its own control.
A first short study of 21 conducted on 17 volunteers (mean age 44 years [19 to 61 years]). A second, longer, of 2 months, conducted on 38 volunteers (mean age 47 years [19 to 68 years]).
Each panel were given a cream according to above example 4.2 and its respective placebo cream, that were massaged into one side of the face twice a day for a set period.
For the Vapometer® and wettability tests, the cream was applied to a forearm and the placebo cream to the opposite arm.
The study synopsis can be summarised according to the following diagram:
T0: Corneometer®, Moisturemeter™, Vapometer®, Skin wettability;
T 21 days: Corneometer®, Moisturemeter™;
T 2 months: Corneometer®, Moisturemeter™, Vapometer®, Skin wettability;
T 2 months+1 week: Corneometer®, Moisturemeter™.
Evaluation of Hydration
Hydration measurements were recorded using two complementary devices: the Corneometer® CM825 (Courage & Khazaka) and the MoistureMeter-D™ (Delfin). Both devices use the electrical properties of the ski and record an impedance measurement directly related to the water content of the skin. They provide information at various depths in the skin.
In each of these techniques, the signal recorded decreases very quickly with depth. Thus, the stratum corneum and superficial epidermis are mostly explored with the Corneometer®, which in theory, can record to a maximum depth of 100 μm. Similarly, the superficial epidermis and deep epidermis tend to be explored with the MoistureMeter-D™ (probe XS5), which nevertheless has a theoritical maximum depth of 500 μm.
A first measure was initially carried out to assess the restructuring and re-balancing effect of the Lipo-Phosphomalate on the face.
The measurements after 21 days were taken one night after the last application. Table 15 show the marked effect of the cream containing the Lipo-Phosphomalate compared to the placebo cream this only after 21 days of application.
TABLE 15
Improvement in skin homeostasis, measurements with the Corneometer ®, following
application of the cream containing the Lipo-Phosphomalate on the face. (Mean
values recorded on N = 17 volonteers, n = 3 measurements/volonteer)
T0
T 21 days
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Mean
46.24 ± 7.96
45.10 ± 8.97
49.04 ± 15.22
42.43 ± 17.04
Mean of the
1.14; nsd
6.61; p < 0.02
differences
Changes (%)
+2.5%
+15.6%
(→ max*)
(→ 48.4%)
Differences between the
+13.1%; p < 0.04
cream of the invention/
(→ 44.6%)
Placebo
*Max: mean of the 9 best responders
nsd: non significant difference; Student's t test
Hydration of the first layers of the stratum corneum of the face, measured with the Corneometer®, varied significantly by 13.1% on average between the zones with the Lipo-Phosphomalate containing cream and the zones with the placebo cream (p<0.04); this variation reached +44.6% for the 9 best responders.
A significant increase in hydration was also recorded with the MoistureMeter-D™ on the side of the face treated with Lipo-Phosphomalate containing cream of the invention; this increase was almost 17% (p<0.05 compared to placebo) with the variation reaching +44.0% for the 9 best responders.
TABLE 16
Improvement in skin homeostasis measured with the MoistureMeter-D ™, following
application of the cream containing the Lipo-Phosphomalate of the invention on
the face (Mean values on N = 17 volonteers, n = 3 mesurements/volonteer)
T0
T 21 days
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Mean
35.30 ± 9.32
36.08 ± 8.88
38.88 ± 9.67
33.98 ± 11.69
Difference
−0.78; nsd
4.90; p < 0.02
Cream of the
invention/Placebo*
Change (%)
−2.2%
+14.40%
Cream of the
(→ 41.5%)
invention/Placebo
(→ max*)
Differences
+16.6%, p < 0.02
(→ 44.0%)
*Max: mean of the 9 best responders
nsd: non significant difference; Student's t test
For the long term study over two months, as previously, measures were taken one night after the last application. The results with the Corneometer® confirm the positive trend already obtained with the short study; moreover, these results show that mean hydration of the face is highly increased on the side of the cream according to the invention compared to the placebo. Thus, for the panel as a whole (N=38), the increase between T0 and T2 months is of the order of +30.4%, this increase being highly significant (p<0.01) compared to the placebo which did not vary during this interval. This variation reached +58.0% for the 19 best responders.
Remarkably, the results show that, in men, the increase between T0 and T2 months was +38.4% on average (p<0.01 compared to the placebo; table 17). This variation amounted +59.0% for the 9 best responders.
TABLE 17
Improvement in skin homeostasis measured with the Corneometer ®, following
application on the face of the cream of the invention containing
the Lipo-Phosphomalate (mean values on N = 38 volonteers*
including 16 men (♂), n = 3 mesurements/volonteer)
T0
T 2 months
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Mean*
40.93* ± 8.93
43.02* ± 8.28
54.03* ± 12.78
43.04* ± 10.51
Difference*
−2.09* and
10.98* and
Cream containing
−2.46 (♂)
14.33 (♂)
the Lipo-
Phosphomalate/
Placebo
Change (%)
−4.9%; nsd*
+25.5%; p < 0.01*
Cream containing
and
(→ 52.8) and
the Lipo-
−5.7% (♂); nsd
+32.8% (♂), p < 0.01
Phosphomalate/
(→ 57.0)
Placebo (→ max)
Differences
+30.4%; p < 0.01*
(→ 58.0) and
+38.4% (♂); p < 0.01
(→ 59.0)
*N = 38; nsd: non significant difference; Student's t test
→ Max: mean of the best responders
To complement this, the measurements realised more in depth with the MoistureMeter-D™ show similar tendency. As a matter of fact, with the cream containing the Lipo-Phosphomalate, hydration of the face is highly increased in the whole panel (+28.6%; p<0.01). This variation reaches +48.5% for the 19 best responders.
As previously, the increase is here also greater for the males (+34.3%; p<0.01) compared to the placebo which changed insignificantly. This variation reaches +53.6% for the 9 best responders (table 18).
TABLE 18
Improvement in skin homeostasis measured with the MoistureMeter-D ™
after applying the cream containing the Lipo-Phosphomalate on the face (Mean
values on N = 38 volonteers including 16 men (♂), n = 3 measurements/volonteer)
T0
T 2 months
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Mean
40.11 ± 7.40
40.89 ± 7.89
49.48 ± 9.02
39.04 ± 8.74
Difference*
−0.78* and
10.44* and
Cream containing
−1.63 (♂)
12.4 (♂)
the lipo-
phosphomalate/
Placebo
Change (%)
−1; 9%*; nsd
26.7%*; p < 0.01
Cream containing
and
(→ 46.8%) and
the lipo-
−3.9% (♂); nsd
30.3% (♂); p < 0.01
phosphomalate/
(→ 48; 2%)
Placebo
Differences
28.6%*; p < 0.01
(→ 48.5%) and
34.3% (♂); p < 0.01
(→ 53.6%)
*N = 38; non significant difference; Student's t test
→ Max: mean of the best responders
These results clearly show that the trend observed at 21 days with the cream containing the Lipo-Phosphomalate of the invention was thre intensified after 2 months. Skin homeostasis of the volunteers, as shown in the hydration protocol, one night after the final application, is increased. The epidermis therefore seems to have acquired a reservoir of moisturizing or wetting agents, which is not linked to the composition of the cream since no change was observed on the placebo side.
Remanence Study
One week after the last application, a new measurement was recorded in a part of the volunteer panel (n=27 volonteers, 16 women and 11 men). The results obtained with the Corneometer® and the MoistureMeter-D™ show the remarkable resistance to drying out recorded for the site treated with the cream containing the Lipo-Phosphomalate of the invention compared to the placebo (tables 19 and 20).
TABLE 19
Remnant of the improvement of cutaneous homeostasis of the face after one week without application,
measured with the Corneometer ®. (mean values on N = 27 volonteers, n = 3 mesurements/volonteer)
T0
T 2 months
T 2 months + 1 week
Cream containing
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Mean
42.23 ± 9.08
43.00 ± 8.17
57.89 ± 12.16
44.12 ± 11.07
47.30 ± 12.97
42.65 ± 11.44
Difference Cream
−0.7; nsd
+13.77; p < 0.01
+4.64; p < 0.01
containing the lipo-
phosphomalate vs.
Placebo
% change Cream
−1.8%
+31.2%
+10.9%
containing the lipo-
(→ +24.5%)*
phosphomalate vs.
Placebo
% change
+12.7%; p < 0.01
T 2 months +
(→ +27.1%)*
1 week vs. T0
( )*½ panel = 14 best responders.
TABLE 20
Remnant of the improvement of cutaneous homeostasis of the face after one week without application,
measured with the MoistureMeter-D ™ (mean values on N = 27 volonteers, n = 3 mesurements/volonteer)
T0
T 2 months
T 2 months + 1 week
Cream
Cream
Cream
containing
containing
containing
5.1 ppm of
5.1 ppm of
5.1 ppm of
Lipo-
Lipo-
Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Mean
40.82 ± 7.55
41.56 ± 6.85
50.81 ± 8.66
39.59 ± 8.50
44.80 ± 8.60
36.48 ± 8.07
Difference
−0.75; nsd
11.23; p < 0.01
8.32; p < 0.01
Cream
containing
the lipo-
phosphomalate
vs.
Placebo
% change
−1.8%
+28.4%
22.8%
Cream
(→ 34.7%)*
containing
the lipo-
phosphomalate
vs.
Placebo
T 2
+24.6%; p < 0.01
months + 1
(→ +35.2%)*
week
vs. T0
( )*½ panel = 14 best responders.
The results show that the cream containing the Lipo-Phosphomalate of the invention triggers a very interesting residual effect after one week without application. Skin hydration is thus maintained at a high level (+23%, p<0.01 in all volunteers on the panel and +35% (p<0.01) for half of the panel).
Evaluation of Homeostasis of the Hydrolipid Barrier
Strengthening of the barrier was assessed from 2 different perspectives:
A dynamic evaluation of the barrier by a measuring of the transepidermal water loss following a stripping-induced rupture in the barrier. A visual evaluation of the barrier by measuring its wettability.
Mesurement of TEWL
The establishing and maintaining of the hydrolipid skin barrier are essential for the organism. In the assay reported below, the re-establishment of this barrier was assessed after rupture triggered by repeated strippings.
At T0, transepidermal water loss (or TEWL) of the forearm was measured using the Vapometer® (Delfin), a device using a closed chamber. A series of strippings was then carried out in a controlled manner in an attempt to slightly disrupt barrier homeostasis. The destruction-mediated increase in TEWL was measured at steady-state. This method allows barrier resistance to be evaluated.
After applying the cream containing the Lipo-Phosphomalate of the invention or the placebo cream, a protocol identical to the one used on TO was followed. This facilitated the evaluation of a potential improvement in resistance.
Table 21: Mean increase in TEWL following disrupted homeostasis (Mean values recorded in N=38 volonteers, n=3 mesurements/volonteer).
TABLE 21
Mean increase in TEWL following disrupted homeostasis (Mean values recorded
in N = 38 volonteers, n = 3 mesurements/volonteer).
T0
T 2 mois
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Loss of homeostasy
6.63 ± 5.00
6.36 ± 4.60
1.70 ± 1.50
3.40 ± 2.5
(in g/m 2 /h)*
Difference*
+0.27
−1.70
Cream containing
the Lipo-
Phosphomalate/
Placebo cream
Change (%)
−4.2%**; nsd
+50%**; p < 0.01
Cream containing
the Lipo-
Phosphomalate/
Placebo cream
% change
+54.2%; p < 0.01
T 2 months vs. T0
*Mean differences in TEWL between before and after rupture by strippings.
**100 × (Placebo-cream of the invention)/Placebo; nsd: non significant difference; Student't test
The destruction at T0 increased the TEWL by approximately 6.5 units on both the site of the cream according to the invention and on the placebo site is observed (i.e. homeostasis rupture).
Conversely, after 2 months's treatment, the responses were very different depending on the product tested.
As to the placebo, the rupture in homeostasis was less pronounced than at T0, mainly due to the massage effect, but the increase in TEWL was nevertheless high (3.40 units), i.e. a difference of 2.96 units compared to T0. With the cream containing the Lipo-Phosphomalate of the invention, the destruction at 2 months caused only a slight rupture in homeostasis (1.70 unit), with a gain of 5.03 compared to T0. The difference between the two cases is very significant and in favour of the cream according to the invention. The cream according to the invention improves the barrier of +54.2% (p<0.01).
Wettability Measurement
An original measurement of the condition of the skin barrier can be obtained by measuring the wettability of the skin. A drop of water deposited on the skin can interact with the skin in a totally different manner depending on the condition and, therefore, the composition, of the barrier.
From a physico-chemical standpoint, one drop deposited on the skin will spread only slightly if the skin is hydrophobic (dry, atopic skin, lipid-depleted due to soaps). Its wettability is said to be poor. Conversely, an improvement in the quality of the stratum corneum improves the wettability of the skin.
Using this property, we deposited a microdrop of water (10 μL) in a reproductible manner on the skin and measured its ability to spread using a video microscope (Scalar) and image analysis software. Although imperfect because it was less detailed than contact angle measurements and similarly less accurate, measurement of the surface area occupied by the drop of water on the skin was nevertheless a good indicator of skin wettability.
TABLE 22
Mean variation in the wettability of a drop on the forearm
following application of the cream containing the Lipo-
Phosphomalate of the invention (Mean values recorded in
N = 37 volonteers, n = 3 mesurements/volonteer).
Cream containing 5.1 ppm of
Lipo-Phosphomalate
PLACEBO
T0
T 2 months
T0
T 2 months
Occupied
9.73 ± 2.80
13.03 ± 7.70
10.74 ± 4.3
12.73 ± 6.6
surface
(mm 2 )
Gain vs.
+33.9%
+18.5%
T0 (in %)
Signifi-
p < 0.05
nsd
cance vs. T0
nsd: non significant difference; Student't test
As the results show, the surface occupied by the drop significantly increased by +33.9% (p<0.05) on the site treated with the cream containing the Lipo-Phosphomalate, thus indicating better wettability. This shows that the hydrolipid film is thicker. The placebo site also exhibits increased wettability but which remains not significant. The placebo cream probably supplied the outer layers of the stratum corneum with certain emollient properties, which affected the wettability result.
Evaluation of the Homeostasis of the Wetting Agents
The restoration evaluation of a better balance within the stratum corneum was evaluated by measuring two of the key factors obtained by strippings:
Evaluation of caspase-14 activity, Evaluation of endogenous glycerol production.
Given the large number of samples (strippings) to be collected, these evaluations were carried out solely using a male panel of 15 volunteers.
Caspase-14 Assay
We saw in the in vitro section, that the Lipo-Phosphomalate of the invention induced gene expression and caspase-14 synthesis in cultured keratinocytes and reconstructed epidermis. We have developed an original method for assaying the activity of this enzyme from strips collected from the foerearms of volunteers. These strips (6 DSquame® in total) underwent extraction in a neutral pH buffer. This solution was then placed in contact with a synthetic substrate cleaved by caspase-14; the fluorescence resulting from this process was recorded using a fluorescence reader.
TABLE 23
Assay of the activity of caspase-14 extracted from strips taken from
forearm (Mean values for N = 15 volonteers, 6 strips/volonteer)
T0
T 2 months
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Mean activity
89.6 ± 37.3
86.0 ± 43.2
167.5 ± 71.5
120.5 ± 39.8
(UFA/min/μg of
proteins)
Mean of the
+3.6; nsd
+47.0; p < 0.02
differences
Changes (in %)
+4.2%
+39.0%
Differences cream
+34.8%
of the invention/
Placebo
nsd: non significant difference; Student't test
These results show that the activity of caspase-14 is incrased on average by +34.8% on the side treated with the cream containing the Lipo-Phosphomalate compared to the placebo side (p<0.02). The increase in this activity in the upper layers of the stratum corneum highlights the increase in the production of this enzyme observed in molecular biology and immunofluorescence.
Endogenous Glycerol Assay
In parallel to the caspase-14 assay, we used the same extracts to evaluate the quantity of glycerol present in the upper layers of the epidermis before and after application of the cream containing the Lipo-Phosphomalate of the invention or the placebo cream. This method allows free glycerol to be assayed thanks to the cascade of enzymatic reactions, finally giving a coloured reaction, which was assayed at 540 nm.
TABLE 24
Assay of glycerol extracted from strips taken from the foerarms
(Means values recorded in N = 15 volonteers, 6 strips/volonteer)
T0
T 2 months
Cream containing
Cream containing
5.1 ppm of Lipo-
5.1 ppm of Lipo-
Phosphomalate
PLACEBO
Phosphomalate
PLACEBO
Glycerol mean
0.164 ± 0.115
0.169 ± 0.135
1.128 ± 0.641
0.266 ± 0.177
(nmol/μg of
proteins)
Mean of the
−0.005; nsd
+0.862; p < 0.01
differences
Changes (%)
−3%
+325%
Differences cream
+328%
of the invention/
Placebo
nsd: non significant difference; Student't test
These results show that the quantity of glycerol found in the stratum corneum increased by +328% on average on the side to which the cream containing the Lipo-Phosphomalate was applied compared to the placebo side (p<0.01).
The quantities detected are consistent with those given in the literature. The increase in this component, which is essential for skin hydration, is linked to the inductin observed in molecular biology of the LIPE lipase known to hydrolyse triacylglycerols, mono- and diglycerides as well as cholesterol esters in keratinocytes; this lipase would, therefore allow the salting out of glycerol in the cell and its subsequent accumulation in the corneocytes.
All these results recorded in volunteers who applied the cream containing the Lipo-Phosphomalate or the placebo cream show that the cream containing the Lipo-Phosphomalate can boost water homeostasis in the skin by promoting the synthesis of compounds essential for this homeostasis. Thus filaggrin and its key enzymes such as caspase-14 provide the cell with its wetting agents of protein origin. Moreover, complex lipids such as ceramides or cholesterol, which establish the barrier function, care increased. Finally, a rise in intra-cornocytic glycerol—a component with strong wetting properties—completes the picture. | The compound according to the invention has the following developed formula IX:
wherein:
X=PO(OH) 2 ; SO 2 (OH); PO(OH)(Xaa) m or SO 2 (Xaa) m ; A=H; OH; NH 2 or akyl (1-6C); n=1 to 4; Y=—CO—OR 2 ; —CO—NR 3 R 4 ; —O—CO—R 2 ; —C═CR 2 ; R 2 =an alkyl, aryl, aralkyl, acyl, sulfonyl, sugar or alkoxy chain of 1 to 24 carbon atoms, linear, branched or cyclic, with or without substitutions, saturated or not, hydroxylated or not, sulfurated or not; R 5 =OH, O-alk (1-6C), (Xaa) m , NH 2 or NH-alkyl(1-6C); Xaa=peptide of m aminoacids Xaa with m from 1 to 10;
The compound is preferably phosphated, obtained from malic acid and having the following developed formula:
A cosmetic composition comprising the compound of the present invention can improve the general condition of the skin, for example hydration, lightening and mechanical properties. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 08/245,971 filed on May 19, 1994, now U.S. Pat. No. 5,522,593. The application hereinabove is incorporated herein and is a part thereof.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a golf club head, especially relates to so-called an iron golf club head, a putter golf club head or a pitching golf club head.
(b) Description of Prior Art
For example, U.S. Pat. Ser. No. 4,874,171 discloses in its FIG. 5 a golf club head provided with sythetic resin containing reinforcing fiber (the specific gravity ranging from 2 to 4) on metallic sole at the back of face. The prior head has the upper end of the synthetic resin member connected to the upper end of face, while the lower end thereof connected to the back end of sole having protrusion thereon. Further, the back surface of the synthetic resin member is formed with arc-shaped convex curved surface.
It is well acknowledged that you can enlarge a sweat area in a golf club head by elongating the depth of the CG of the head (i.e.,elongating the distance between the face and the center of gravity.) and having the weight distribution of face biased toward periphery of the head. Particularly, such weight distribution is effective in preventing the unsteadiness of the head in striking balls, since an ordinary head is unstable unless balls are struck at the center of face.
According to the prior head shown in FIG. 5 of U.S. Pat. No. 4,874,171, although the center of gravity can be postioned backward by providing the protrusion in the center of sole, the head is too partially weighted at sole side, therefore, there is no consideration for enlarging sweet area by dispersing the weight distribution on face.
In addition, when a player addresses a ball prior to striking the same, he is generally required to carefully choose the positional relationship between the face and the ball. According to U.S. Pat. No. 4,874,171, however, as the back surface of the synthetic resin member is formed with arc-shaped convex curved surface, such convex curved surface will be an obstacle to addressing a ball.
SUMMARY OF THE INVENTION
To eliminate the above-mentioned problems, it is, therefore, an object of the present invention to provide a golf club head which has a larger sweet area.
It is another object of the present invention to provide a golf club head of which the balance weight will not disturve a player's concentration in addressing balls.
According to a major feature of the present invention, a golf club head comprises: a head body having a face at its front and a concave portion at its back, said concave portion being defined by a rear surface of the head body and a peripheral portion of the back; a balance weight made of material denser than that of said head body which, is secured into said concave poriton, the back of said head body being located on the same plane relative to a back of said weight, wherein said peripheral portion is thickened such that a depth of said concave portion is greater at its lower side than at its upper side, while a height thereof is greater at its inside than at its outside.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention will be apparent to those skilled in the art from the following description of the preferred embodiments of the invention, wherein reference is made to the accopmpanying drawings, of which:
FIG. 1 is a section showing a first embodiment of the invention.
FIG. 2 is a perspective view showing a first embodiment of the invention.
FIG. 3 is a rear view showing a first embodiment of the present invention.
FIG. 4 is a section showing a second embodiment of the invention.
FIG. 5 is a section showing a third embodiment of the invention.
FIG. 6a is a section showing a fourth embodiment of the invention.
FIG. 6b is an enlarged view of a section showing a fourth embodiment of the invention.
FIG. 7 is a perspective view showing a fourth embodiment of the invention.
FIG. 8 is a rear view showing a fourth embodiment of the invention.
FIG. 9 is a section showing a fifth embodiment of the invention.
FIG. 10 is a section showing a sixth embodiment of the invention.
FIG. 11 is a perspective view showing a sixth embodiment of the inveniton.
FIG. 12 is an exploded perspective view showing a sixth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter is described a first embodiment of the present invention with reference to FIGS. 1 to 3.
Referring to FIG. 1, reference numeral 1 designates a head body made of titanium, aluminium or the alloy thereof, having face 2 inclined at a preset angle at its front side, neck 4 at one side for connecting shaft 3 thereto. The back of the head body 1 is formed with concave portion 5 having entire periphery of thickened portion 1A, thus forming sole 1B at its bottom side.
The depth A of a lower portion of the concave portion 5 is formed greater than the depth B of the upper portion thereof, while the height D of the inside or front portion greater than the height C of the outside or back portion thereof.
The weight 6 to be provided in the concave portion 5 is formed of comparatively denser materials, such as iron, copper, beryllium copper alloy or lead, which is pressed into the concave portion 5 by means of a pressing device or the like, thus securing the same to the head body 1. In such pressing-in and securing operation, the back surface of the head body 1 is formed on the same plane relative to back surface 6A of weight 6, as shown in a dotted line of FIG. 1. In the boundary portion between back surface 1A and 6A is provided a small groove 7 having V-shaped section as an ornament, which is colored red or the like (not shown).
With the structure thus made, as weight 6 denser than head body 1 is provided in the back thereof, the CG thereof can be positioned backward, thus elongating the depth Le of the CG to enlarge sweet area. Further, the concave portion 5 has such a dovetail structure that the lower depth A is formed greater than the upper depth B, while the comparatively inside height D greater than the comparatively outside height C, thereby ensuring the securing of the head body 1 to the weight 6, and thus further elongating the depth Le of the CG since the center of gravity (not shown) of weight 6 itself is lowered and positioned backward. Furthermore, as the back surface of the head body 1 is provided evenly with respect to the back surface 6A of the weight 6, there will be no obstacles to the view in the back portion of a club head, so that a player can enhance his concentration in addressing balls.
In addition, since the back surface of the head body 1 is formed annular such that the entire periphery thereof is thickened as illustrated by the thickened portion 1A, titanium, aluminium or the alloy thereof can be disposed in the back periphery of the face 2, thus realizing well-dispersed weight distribution. Consequently, if a player strikes a ball slightly off the center of the face 2, he can still be free from unsteadiness of the head when striking a ball due to the excellent dispersion of weight distribution.
In FIGS. 4 and 5 showing second and third embodiments of the invention respectively, the same portions as those described in a first embodment will be designated as common reference numerals, and their repeated detailed description will be omitted.
In a second embodiment, there is provided convex portion 12 protruding backward from approximately the center of bottom surface 11 of concave portion 5 formed in head body 1. The cross-width defined by side surface 13 of the convex portion 12 generally increases toward the back, i.e., formed reverse-tapered, so that weight 6 can be also secured by this dovetail-shaped convex portion 12. Similarly to a first embodiment, back surface 1A of the head body 1 is formed on the same plane relative to back surface 6A of the weight 6. Accordingly, in this embodiment, the weight 6 can allow the depth of CG to be greater, and there will be no obstacles to the player's view in the back portion of a club head, so that he can enhance his concentration in addressing balls as well.
In FIG. 5 showing a third embodiment of the invention, the same structure as that shown in a first embodiment is applied to a putter golf club head. That is, there is provided concave portion 5 in a head body 1, into which is pressed weight 6 denser than head body 1. Similarly, each structure shown in each foregoing embodiment can be applied to not only an iron golf club head but a putter golf club head.
Incidentally, in the preceding embodiments, any suitable combination of material for head body 1 and weight 6 may be provided.
Referring to FIGS. 6 to 8 showing a fourth embodiment of the invention, reference numeral 21 designates head body made of stainless steel, copper, beryllium copper alloy or lead, having face 22 inclined at a preset angle at its front side, hosel 24 at one side for connecting shaft 23 thereto. The back of the head body 21 is formed with concave portion 25 having entire periphery of thickened portion 21A, thus forming sole 11B at its bottom side.
The depth E of a lower portion of the concave portion 25 is formed greater than the depth F of the upper portion thereof, while the height H of the inside portion greater than the height G of the outside portion thereof. There is provided protrusion 27 integral with bottom portion 26 of the concave portion 25, said protrusion 27 having reverse-trapezoid section, having wider dimension at its back side, while narrower dimension at its bottom 26 side. Balance weight 30 provided in the concave portion 25 is made of material having the less specific gravity than that of head body 21, such as titanium, aluminium or the alloy thereof, which is formed in advance slightly greater than the concave portion 25, having another concave portion 31 slightly smaller than the opposite protrusion 27.
After the balance weight 30 is pressed into the concave portion 25 by a suitable pressing device, the back surface of the head body 21 is disposed on approximately the same plane relative to back surface 30A of the balance weight 30, as illustrated in FIG. 6. More specifically, there is provided continuous concave curvature defined by the back of the head body 21 and the back surface 30A of the balance weight 30.
As to a combination of materials, since the greater difference in the specific gravity between the head body 21 and the balance weight 30 is desirable, the head body 21 may be preferably made of beryllium copper alloy., while balance weight 30 made of titanium alloy.
Referring to an enlarged section in FIG. 6, there is provided groove 32 formed by endmilling or the like, thus making clear boundary line adding the beauty, which, without such goove 32, might become unclear when securing the weight 32, as shown in a dotted line thereof. The groove 32 is arc-shaped, having a height I in section and a depth J, being colored blue, red or the like.
With the structure thus made, as the back surface of the head body 21 is located on approximately the same plane relative to the back surface 30A of the balance weight 30, a player can enhance his concentration in addressing a ball as being free from an obstacle to the view at that time. Particularly, as there is provided continuous concave curvature defined by the back of the head body 21 and the back surface 30A of the balance weight 30, he can visually confirm back end 11B' of sole 11B when addressing a ball.
Further, the back of the head body 21 is formed annular such that the entire periphery thereof is thickened as designated as thickened portion 21A, whereby denser metallic material such as stainless steel, copper, beryllium copper alloy or lead can be disposed in the periphery of the back of the head body 21. Accordingly, the head body 21 is partially weighted at the periphery of the back of face 22, thereby ensuring the accurate striking if a ball is struck slightly off the center of face 22.
In a preferred form of the invention, as the head body 21 is formed of beryllium copper alloy, while the balance weight 30 formed of titanium alloy, the difference in the specific gravity between the two members can be greater, so that excellent positioning of the CG of the head can be realized. Additionally, such position of the CG can be further fine adjusted so as to be best suited for a discrete player by adjusting the width I and depth J of the groove 32. In addition, as the groove 32 is arc-shaped in section, sand or soil is hard to choke it up, thus keeping it clean. The endmilling of the groove 32 is also advantageous in respect of accuracy and easiness in such milling.
In FIG. 9 showing a fifth embodiment of the invention, there is not provided the groove 32 of a fourth embodiment, and the back surface of the head body 21 is located on the same plane relative to the back surface 30A of the balance weight 30.
As to a combination of materials for head body 21 and balance weight 30, any suitable combination may be selected in a fourth and fifth embodiment as well as the preceding embodiments.
In FIGS. 10 to 12 showing a sixth embodiment of the invention, reference numeral 43 designates head body, which is made of stainless steel (the specific gravity 7.8), having hosel 42 for connecting shaft 41 thereto, and is formed with sole 44, heel 45 and top 46. Sole 44, heel 45 and top 46 define a face equivalent portion which has a striking face 47. Striking face 47 corresponding to face of the head body 43 is provided with through-hole 49 extending up to back face 48 of the head body 43, into which is securely inserted face member 50. The through-hole 49 is formed with stepped portions such as the first and second dovetail grooves 51 and 52. The first groove 51 has outside width K less than inside width L (K<L), while the second groove 52 has inside width M less than the inside width L (M<L). The head body 43 is formed thicker at sole 44 side than at top 46 side (i.e., N>P).
The face member 50 is made of material of the specific gravity less than that of head body 43, such as pure titanium (the specific gravity: 4.5) or titanium alloy. The front surface of the face member 50 is formed with face 50A, while the back surface thereof is formed with protrusion 50B, which reversely corresponds in shape to the through-hole 49 having dovetail grooves 51 and 52, yet formed slightly greater than the same, so that the protrusion 50B is pressed from the striking face 47 side into the through-hole 49 to be secured thereto until the back surface 53 thereof arrives through stepped portion 56 at nearly the same plane relative to the back surface 48 of the head body 43. In a preferred form of the invention, the back surface 53 is curved slightly concavely.
Reference numeral 54 is an ornament ring made of synthetic resin, which is firmly fitted into the stepped portion 56 between the back surfaces 48 and 53. The ring 54 has a circular section and is approximately pentagonal seen from the front, which is colored with suitable color other than that of the head body 43, for example, purple or the like. Reference numeral 55 designates grooves called score lines formed on face 50A.
In a preferred form of the invention, the back surface 53 of the protrusion 50B may be positioned on the same or approximately the same plane relative to the back surface 48 of the head body 43, and the thickness X of face member 50 may be at least 70% of the depth Q of the through-hole 49, more preferably 80% or above, most preferably 90% or above thereof.
Now the action and effect of a golf club head having the above-described structure will be explained.
The center of gravity CG of the head body 43 is displaced toward back and sole 44 side, owing to the greater thickness of the thickness N relative to the thickness P (N>P). Thus, the distance Le between the center of gravity CG and the face 50A can be elongated to enlarge sweet area. Further, as the head body 43 made of stainless steel having the through-hole 49 is denser than the face member 50 made of pure titanium or titanium alloy, the weight distribution of the head can be effectively dispersed toward the periphery of the head, thus further enlarging sweet area.
Furthermore, as the back surface 53 of face member 50 is formed so thick that it arrives at nearly the same plane relative to the back surface 48, the face member 50 is less subjected to elastic deformation when striking a ball, thus ensuring the enhancement of a sense of stability when striking a ball.
Additionally, as the head body 43 is made of stainless steel, while the face member made of pure titanium or titanium alloy, the difference in the specific gravity between the two members can be greater such that a ratio of the specific gravity is 1 to 0.58, thereby enlarging the depth of the CG and obtaining still dispersed weight distribution.
In addition, in this embodiment, there is provided the stepped portion 56 between the back surfaces 48 and 53, in which is securely fitted the ornament ring 54, whereby the joint line can be covered therewith to enchance the beauty. The ring 54 has the circular section free of abrupt corners, so that it will not be an obstacle to a player's concentration when addresing a ball. As the head body 43 is connected to the face member 50 by dovetail joint, the connection strength can be enhanced.
Alternatively, the head body may be made of beryllium copper alloy, while the face member made of aluminium alloy in a sixth embodiment. | A golf club head having a larger sweet area for easier visual confirmation by a player when adressing a ball. Head body 1 is provided with denser weight at its back, thus displacing CG toward a back side of the head body 1 to enlarge a depth Le of CG and sweet area. The back of the head body 1 is located on the same plane relative to the back 6A of the weight 6, thus eliminating an obstacle to view when a player addresses a ball to enhance the concentration of the player. The back of the head body 1 is annularly formed with thickened portion 1B so that the entire periphery of the back is suitably weighted with titanium, aluminium or the alloy thereof. Owing to such dispersed weight distribution, a player can be free from a sense of unstability and accuratetly strike a ball if the ball is struck a little off the center of face 2. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation patent application of International Application No. PCT/SE02/01342 filed 4Jul. 2002 which was published in English pursuant to Article 21(2) of the Patent Cooperation Treaty, and which claims priority to Swedish Application No. 0102769-7 filed 20 Aug. 2001. Both applications are expressly incorporated herein by reference in their entireties.
BACKGROUND OF INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to an arrangement for an internal combustion engine of the turbocompound type and that includes an exhaust system for ducting the engine's exhaust gases. A supercharger turbine drives a compressor for the engine's combustion air and an exhaust turbine is also included that is located in the exhaust system downstream of the supercharger turbine for extracting residual energy from the exhaust flow via transmission to the crankshaft of the internal combustion engine. The exhaust system also includes an exhaust braking throttle located downstream of the exhaust turbine.
[0004] 2. Background Art
[0005] In a turbocompound engine (TC engine), power is transmitted from the power turbine of the TC unit, via a gear mechanism, down to the engine's crankshaft. This power is obtained by extracting the residual energy that remains in the engine's exhaust gases after having passed through the turbo compressor for compressing the engine's charging air.
[0006] For engine braking, it is normal for an exhaust brake to be used. For a TC engine, the exhaust brake consists of a suitable arrangement, normally a throttle valve that can throttle the exhaust flow, and it is placed downstream of the TC unit. When the valve is closed and the fuel injection ceases, power is transmitted instead from the crankshaft via a gear to the TC unit's power turbine. This power helps to increase the braking effect as it is an energy loss, but which is positive from a braking perspective. A problem that can arise, however, is that a valve that has been closed downstream of the TC unit will increase the density of the air in which the TC unit's power turbine is operating. This, of course, assists the braking, but it also gives rise to increased thermal and mechanical stresses. These increased stresses will depend upon the engine speed and will increase with increased engine speed. In order that the TC unit or other components do not break, they must be dimensioned for the increased stresses. This can lead to the construction being unnecessarily expensive, as it is made more complicated and as expensive heat-resistant material must be used.
[0007] With an exhaust brake, the braking effect increases for a given engine speed when the back pressure after the turbine increases. In order to obtain best braking function, as high as possible back pressure is desired. For a TC engine, this is particularly difficult, as the stresses that were mentioned above arise as a result of the back pressure increasing. For a given back pressure, the stresses also increase when the engine speed increases. In order that components do not break, they must be constructed so that they can withstand the stresses that arise at the maximal permitted engine brake speed. Alternatively, a lower back pressure can be selected. A lower back pressure can be presumed still to give acceptable braking performance at high engine speeds, but at low engine speeds the braking effect is commensurately low. Thus, in order to obtain a good braking effect at low engine speeds, high back pressure is required. This in turn leads to large forces at high engine speeds, or alternatively using low back pressures at a high engine speed and obtaining a poor braking effect at low engine speeds.
SUMMARY OF INVENTION
[0008] An object of the invention is therefore to achieve an arrangement that makes possible rapid and effective regulation of the exhaust back pressure during engine braking.
[0009] This object is achieved by a means for braking that is configured *so that the exhaust braking throttle comprises (includes, but is not limited to) a pressure-controlled exhaust pressure regulator that makes possible variable regulation of an exhaust braking pressure in at least one step in addition to “off” and “on” steps. Furthermore, the exhaust pressure regulator is provided with means for adapting the exhaust braking pressure to the engine speed. By means of this solution, it is possible to optimize the braking effect for all engine speeds without being forced to select expensive constructional solutions. At low engine speeds, a high back pressure is selected that gives acceptable braking effect and acceptable stresses. At high engine speeds, a lower back pressure is selected that gives acceptable stresses and acceptable braking effect. With this solution, the braking effect can thus be optimized for the selected constructional solution and the selected material over the entire range of engine speeds. This means in principle that for each engine speed there is a unique back pressure that gives maximal braking effect without leading to the inducement of unacceptable stresses.
[0010] According to an advantageous embodiment of the invention, the exhaust pressure regulator is provided with means for adapting the exhaust braking pressure to the engine speed.
[0011] According to one variant of the invention, the exhaust braking throttle comprises an exhaust valve placed in the exhaust system downstream of the exhaust turbine and regulating a parallel bypass with the exhaust pressure regulator.
[0012] The exhaust pressure regulator consists suitably of a piston valve that comprises a first piston surface that is acted upon by the exhaust pressure when the exhaust braking throttle is closed, and a second opposing piston surface permanently connected to the first piston surface, which second piston surface is acted upon by a control pressure.
BRIEF DESCRIPTION OF DRAWINGS
[0013] The invention will be described in greater detail in the following, with reference to the embodiments that are shown in the attached drawings, in which:
[0014] FIG. 1 is a schematic diagram showing a first embodiment of an arrangement configured according to the teachings of the present invention, and
[0015] FIG. 2 schematically shows a second embodiment of an arrangement configured according to the teachings of the present invention.
DETAILED DESCRIPTION
[0016] The arrangement shown in the figures is configured for utilization with an essentially conventional internal combustion engine of the turbocompound type, preferably incorporated in the drive unit of a heavy truck or bus. The engine may advantageously be of the direct-injection diesel engine type in which a supercharger 10 , with exhaust gas driven turbine 11 and compressor 13 arranged on the turbine shaft 12 , are used for the compression and supply of combustion air. The inlet air is supplied to the compressor 13 for compression, after which the compressed air can be cooled during its passage through a charging air cooler before it enters the engine's inlet manifold.
[0017] The engine's exhaust gases are collected in the conventional way in an exhaust collector to be taken to the supercharger's 10 turbine 11 for driving the compressor 13 . The exhaust gases are then taken via a second exhaust turbine, which in the embodiment shown consists of an axial turbine 15 and an exhaust brake arrangement 16 , to a silencer unit with optional exhaust gas filter equipment.
[0018] The axial turbine 15 is used in turbocompound engines to extract residual energy from the exhaust gases after their passage through the supercharger's turbine. The exhaust gases drive the power turbine at very high speeds, up to approximately 90,000 rpm at a normal engine speed, which for a diesel engine for heavy trucks involves an engine speed of approximately 1,500-2,500 rpm. The torque that is obtained is transmitted to the crankshaft of the internal combustion engine via, among other things, a transmission 17 that gears down the speed, and a fluid coupling 18 that isolates the transmission 17 mechanically from the engine's crankshaft.
[0019] The exhaust brake arrangement 16 comprises a throttle 19 that can be moved between two end positions by means of a servo device 20 , with the throttle rapidly changing between a completely open and a completely closed position. The exhaust brake arrangement comprises, in addition, a bypass 21 past the throttle 19 , which bypass can be controlled by means of an exhaust brake regulator in the form of a piston valve 22 which is placed upstream of the throttle 19 . A first piston surface 23 is acted upon by the exhaust pressure when the exhaust braking throttle is closed, with the piston surface 23 being pressed against the action of a helical spring 24 , so that the bypass 21 is opened. A second piston surface 25 is permanently connected to the piston surface 23 via a rod 26 and is mounted in a cylinder 27 in such a way that it can be moved.
[0020] A regulating air pressure acts against the piston surface 25 via a compressed air pipe 28 which is connected to a compressed air system in the vehicle which is used to generate power for auxiliary units in the vehicle, for example the braking system and system for pneumatic operation of the vehicle's gearbox. This compressed air system comprises, among other things, a compressor 29 , an accumulator tank 30 and a valve housing 31 .
[0021] As the second piston surface 25 of the piston valve 22 has a slightly smaller diameter than the first piston surface 23 , the piston valve will be able to react during engine braking and open the bypass 21 past the exhaust braking throttle 16 in the event of an exhaust gas pressure acting against the first piston surface that is less than the pressure that is to be found in the compressed air pipe 29 and thus acts against the second piston surface 25 . For example, the piston surface 23 can have a diameter of ninety millimeters while the piston surface 25 has a diameter of eighty-four millimeters, whereby the piston valve 22 can react to an exhaust gas pressure which is approximately fifteen percent lower than the system pressure.
[0022] The valve unit 31 provides overpressure that can vary from the standby level of 0.5 bar overpressure to a higher level that can be regulated in relation to the required engine braking effect. For this purpose, the valve unit is connected to an engine control unit 32 as shown in FIG. 2 that is arranged to regulate the higher level of overpressure with regard to various parameters. For example, information about the brake pedal pressure and ABS system may be monitored so that the braking power is optimized in relation to the operation of the engine and to the state of the road.
[0023] Such regulation may be exemplarily carried out in the following way: the control pressure, P control , acts upon the piston surface 25 in the exhaust pressure regulator 22 . By this means, a force arises which is transmitted to the piston surface 23 via the rod 26 . This force attempts to hold back the gases that want to pass by the valve 23 and a back pressure, P m , is obtained.
[0024] A state of equilibrium gives:
P m = P s · A 25 A 23 = P control
·constant.
[0025] The control pressure, P control , is adjustable and is adjusted by the valve unit 31 . Since the back pressure is directly proportional to the control pressure, the back pressure will be changed when the control pressure is changed.
[0026] FIG. 2 shows a variation of the invention in which the exhaust brake regulator 16 is designed in a different way to that shown in FIG. 1 . Thus the exhaust pipe is Land the piston valve 22 is set in the angle between the two parts of the pipe. In this case, the throttle 19 and the bypass 21 are not needed, as the changeover from normal operation to exhaust braking is carried out by the piston valve 22 being moved from an inner inactive position to an outer active position. In this position, the piston surface 23 blocks off the exhaust pipe with a pressure that is determined by the valve housing 31 and the engine control unit 40 , so that excess pressure can leak past the piston surface 23 . The variant of the invention shown in FIG. 2 is less expensive to implement than the solution shown in FIG. 1 , but does result in a greater pressure loss in the exhaust pipe.
[0027] An advantage of the arrangement according to the invention is that the braking effect of the engine brake can be regulated. This means that it is possible to obtain different braking effects at different engine speeds. This adjustable braking effect can, for example, be used to reduce the fuel consumption and to increase driving comfort. These side effects are, of course, also obtained if the exhaust back pressure is regulated in an ordinary turbo engine or aspirating engine.
[0028] With the modern control units that are on current engines, this is possible to achieve, and mechanical components are available that are sufficiently quick to be able to achieve the required back pressure. In the example of the regulation system disclosed herein, an indirect setting of the back pressure is carried out by varying the feed pressure to the EPG. This feed pressure gives rise to a predetermined back pressure. An alternative way of controlling the back pressure is to mount a pressure sensor in the collector housing and to measure the pressure and regulate the feed pressure to the air throttle (the EPG) by means of the control unit in such a way that the required back pressure is obtained. This method is, however, more complicated and more expensive than the indirect method. Practical tests have shown that for a normal engine size for heavy trucks, it is almost possible to achieve a constant braking moment over a very large range of engine speeds using the disclosed arrangement.
[0029] The invention is not to be regarded as being limited to the embodiments described above, a number of further variants and modifications being possible within the framework of the following patent claims. | Method and arrangement for a turbocompound type internal combustion engine including an exhaust system for ducting the engine's exhaust gases. A supercharger turbine drives a compressor for the engine's combustion air, and an exhaust turbine is placed in the exhaust system downstream of the supercharger turbine for extracting residual energy from the exhaust flow via transmission to the combustion engine's crankshaft. The exhaust system also has an exhaust braking throttle placed downstream of the exhaust turbine. The exhaust braking throttle includes a pressure-controlled exhaust pressure regulator that makes possible variable regulation of an exhaust braking pressure in at least two steps. | 5 |
TECHNICAL FIELD
[0001] The present invention relates to a load driving device, and to an electronic device incorporating a load driving device.
BACKGROUND ART
[0002] Conventionally, load driving devices such as motor driver ICs and switching regulator ICs are in wide and common use.
[0003] An example of related conventional technology is seen in Patent Document 1 listed below.
LIST OF CITATIONS
Patent Literature
[0004] Patent Document 1: Japanese Patent Application Publication No. 2008-263733
SUMMARY OF THE INVENTION
Problem to be Solved by the Invention
[0005] In general, a component (device) that constitutes an output circuit of a load driving device (in particular, an output device such as a power transistor) is designed to have a withstand voltage that suits the electrical characteristics (such as the absolute maximum rated value of a supply voltage) defined in the specification of the load driving device. Thus, when overvoltage destruction testing exceeding the rating is conducted, the load driving device may suffer smoking or destruction.
[0006] The simplest imaginable solution to the above problem is to raise the withstand voltage of the component. However, raising the withstand voltage (in particular, the gate-source withstand voltage) of the output device among all the components constituting the circuit requires increasing the size of the output device and hence increasing the chip area, posing another problem. In particular, in a load driving device designed to feed a large current to a load, a large output device is used to reduce its on-state resistance, and thus the output device occupies a very large proportion of the entire chip area. Thus, further increasing the size of the output device simply to cope with destructive testing leads to an even larger chip area and hence a higher cost, making the solution impractical.
[0007] Another imaginable solution to the above problem is to provide an overvoltage protection capability on the part of the target product in which the load driving device is incorporated. However, providing the target product with an overvoltage protection capability requires externally fitting additional components to the load driving device, and thus leads to a higher cost of the product as a whole, thereby posing another problem.
[0008] In view of the problem experienced by the present inventors, an object of the present invention is to provide a load driving device that withstands destructive testing without unnecessarily increasing the withstand voltage of a component, and to provide an electronic device incorporating such a load driving device.
Means to Solve the Problem
[0009] To achieve the above object, according to one aspect of the present invention, a load driving device includes: an internal circuit which operates by being fed with a supply voltage; an output circuit which drives a load by being fed with the supply voltage; a fault detection circuit which monitors the supply voltage to generate a fault detection signal; and a power switch which connects/disconnects a supply voltage feed line leading to the internal circuit according to the fault detection signal (a first configuration).
[0010] In the load driving device according to the first configuration described above, preferably, the internal circuit includes a driving circuit which feeds the output circuit with a driving signal (a second configuration).
[0011] In the load driving device according to the second configuration described above, preferably, there is further provided a pull-down resistor which is connected between a supply voltage input node of the internal circuit and a grounded node (a third configuration).
[0012] In the load driving device according to the third configuration described above, preferably, the output circuit includes a p-type upper transistor which is connected between a supply voltage node and an output node (a fourth configuration).
[0013] In the load driving device according to the fourth configuration described above, preferably, there is further provided a first upper switch which connects/disconnects between the gate of the upper transistor and the supply voltage node according to the fault detection signal (a fifth configuration).
[0014] In the load driving device according to the fifth configuration described above, preferably, there is further provided a second upper switch which connects/disconnects between the gate of the upper transistor and the driving circuit according to the fault detection signal (a sixth configuration).
[0015] In the load driving device according to any one of the fourth to sixth configurations described above, preferably, the output circuit includes an n-type lower transistor which is connected between the grounded node and the output node (a seventh configuration).
[0016] In the load driving device according to the seventh configuration described above, preferably, there is further provided a first lower switch which connects/disconnects between the gate of the lower transistor and the grounded node according to the fault detection signal (an eighth configuration).
[0017] In the load driving device according to the eighth configuration described above, preferably, there is further provided a second lower switch which connects/disconnects between the gate of the lower transistor and the driving circuit according to the fault detection signal (a ninth configuration).
[0018] In the load driving device according to any one of the first to ninth configurations described above, preferably, the internal circuit includes a first internal circuit which operates by receiving a first supply voltage and a second internal circuit which operates by receiving a second supply voltage lower than the first supply voltage, and the output circuit includes a first output circuit which drives a first load by receiving the first supply voltage and a second output circuit which drives a second load by receiving the second supply voltage (a tenth configuration).
[0019] In the load driving device according to the tenth configuration described above, preferably, the fault detection circuit includes a first overvoltage detector which monitors the first supply voltage to generate a first overvoltage detection signal, a second overvoltage detector which monitors the second supply voltage to generate a second overvoltage detection signal, and a fault detection signal generator which generates the fault detection signal based on the first and second overvoltage detection signals (an eleventh configuration).
[0020] In the load driving device according to the eleventh configuration described above, preferably, the first overvoltage detector includes a first comparator which generates the first overvoltage detection signal by comparing the first supply voltage with a first overvoltage detection voltage, and the second overvoltage detector includes a second comparator which generates the second overvoltage detection signal by comparing the second supply voltage with a second overvoltage detection voltage (a twelfth configuration).
[0021] In the load driving device according to the eleventh or twelfth configuration described above, preferably, there is further provided a first level shifter which shifts the signal level of, and then feeds to the fault detection signal generator, the first overvoltage detection signal (a thirteenth configuration).
[0022] In the load driving device according to the thirteenth configuration described above, preferably, the first level shifter includes a transistor of which the drain is connected to a node to which the first supply voltage is applied and the gate is connected to a node to which the first overvoltage detection signal is applied; a current source which is connected between the source of the transistor and the grounded node; and an inverter of which the input node is connected to the source of the transistor, the output node is connected to the fault detection signal generator, the first supply voltage node is connected to a node to which the second supply voltage is applied, and the second supply voltage node is connected to the grounded node (a fourteenth configuration).
[0023] In the load driving device according to any one of the eleventh to fourteenth configurations described above, preferably, the fault detection circuit further includes an undervoltage detector which monitors the first supply voltage to generate an undervoltage detection signal, and the fault detection signal generator generates the fault detection signal based on the first overvoltage detection signal, the second overvoltage detection signal, and the undervoltage detection signal (a fifteenth configuration).
[0024] In the load driving device according to the fifteenth configuration described above, preferably, the undervoltage detector generates the undervoltage detection signal by comparing the first supply voltage with an undervoltage detection voltage (a sixteenth configuration).
[0025] In the load driving device according to any one of the first to sixteenth configuration described above, preferably, there is further provided a second level shifter which shifts the signal level of the fault detection signal (a seventeenth configuration).
[0026] In the load driving device according to the seventeenth configuration described above, preferably, the second level shifter shifts the signal level of the fault detection signal from a state where the fault detection signal pulsates between the second supply voltage and a ground voltage to a state where the fault detection signal pulsates between the first supply voltage and a first compensated supply voltage which is lower than the first supply voltage by a predetermined value or to a state where the fault detection signal pulsates between the second supply voltage and a second compensated supply voltage which is lower than the second supply voltage by a predetermined value (an eighteenth configuration).
[0027] In the load driving device according to the eighteenth configuration described above, preferably, there is further provided a compensated supply voltage generator which generates from the first or second supply voltage, and feeds to the second level shifter, the first or second compensated supply voltage (a nineteenth configuration).
[0028] In the load driving device according to the nineteenth configuration described above, preferably, the compensated supply voltage generator includes: a first transistor of which the source is connected to a node to which the first or second compensated supply voltage is applied and the drain is connected to the grounded node; a second transistor of which the emitter is commented to the gate of the first transistor; a zener diode of which the anode is connected to the base and the collector of the second transistor and the cathode is connected to the node to which the first or second supply voltage is applied; a first resistor which is connected between the source of the first transistor and the node to which the first or second supply voltage is applied; and a second resistor which is connected between the emitter of the second transistor and the grounded node (a twelfth configuration).
[0029] According to another aspect of the present invention, an electronic device includes the load driving device according to any one of the first to twelfth configurations described above and a load driven by the load driving device (a twenty-first configuration).
[0030] Preferably, the electronic device according to the twenty-first configuration described above is an optical disc drive which is incorporated in a computer for playback from, or for recording to and playback from, an optical disc, and the load is at least one of a spindle motor, a sled motor, a loading motor, a focus actuator, a tracking actuator, and a tilt actuator (a twenty-second configuration).
ADVANTAGEOUS EFFECTS OF THE INVENTION
[0031] According to the present invention, it is possible to provide a load driving device that withstands destructive testing without unnecessarily increasing the withstand voltage of a component, and to provide an electronic device incorporating such a load driving device.
BRIEF DESCRIPTION OF DRAWINGS
[0032] FIG. 1 is a block diagram showing an exemplary configuration of an optical disc drive according to the present invention;
[0033] FIG. 2 is a circuit diagram of an exemplary configuration of a load driving circuit 11 and a fault detection circuit 12 ;
[0034] FIG. 3 is a circuit diagram showing a modified example of the load driving circuit 11 ;
[0035] FIG. 4 is a circuit diagram showing an exemplary configuration of a switching regulator IC;
[0036] FIG. 5 is a circuit diagram showing an exemplary configuration of a first overvoltage detector 121 ;
[0037] FIG. 6 is a diagram showing an exemplary configuration of an undervoltage detector 122 ;
[0038] FIG. 7 is a circuit diagram showing an exemplary configuration of a second overvoltage detector 123 ;
[0039] FIG. 8 is a circuit diagram showing an exemplary configuration of a level shifter 124 a ;
[0040] FIG. 9 is a circuit diagram showing an exemplary configuration of a compensated supply voltage generator CVG;
[0041] FIG. 10 is a timing chart showing an example of fault protection operation; and
[0042] FIG. 11 is an external view of a desktop PC incorporating an optical disc drive.
DESCRIPTION OF EMBODIMENTS
<Optical Disc Drive>
[0043] Hereinafter, a detailed description will be given of an example where the present invention is applied to a motor driver IC incorporated in an optical disc drive.
[0044] FIG. 1 is a block diagram showing an exemplary configuration of an optical disc drive. The optical disc drive 1 is, for example, incorporated in a personal computer (PC) to allow playback from, or recording to and playback from, optical discs (such as BDs, DVDs, and CDs). The optical disc drive 1 includes a motor driver IC 10 , a plurality of loads 20 , and a microprocessor 30 .
[0045] The motor driver IC 10 is a multiple-channel load driving device which drives and controls, according to instructions from the microprocessor 30 , a plurality of loads (a spindle motor 21 , a sled motor 22 , a loading motor 23 , a focus actuator 24 , a tracking actuator 25 , and a tilt actuator 26 ). The motor driver IC 10 includes, as a multiple-channel load driving circuit 11 , a spindle motor driver circuit 111 , a sled motor driver circuit 112 , a loading motor driver circuit 113 , a focus actuator driver circuit 114 , a tracking actuator driver circuit 115 , and a tilt actuator driver circuit 116 . The motor driver IC 10 further includes a fault detection circuit 12 which monitors a first supply voltage HV (for a 12 V system) and a second supply voltage LV (for a 5 V system), both fed from outside the IC, to generate a fault detection signal S 1 .
[0046] The spindle motor driver circuit 111 is fed with the first supply voltage HV, and drives and controls the spindle motor 21 so as to rotate a turntable (not illustrated), on which an optical disc is placed, at a constant linear velocity or at a constant rotational velocity. Usable as the spindle motor 21 is, for example, a brushed DC motor or a three-phase brushless motor.
[0047] The sled motor driver circuit 112 is fed with the first supply voltage HV, and drives and controls the sled motor 22 so as to slide an optical pickup (not illustrated) in the radial direction of the optical disc. Usable as the sled motor 22 is, for example, a brushed DC motor or a two-phase brushless stepping motor.
[0048] The loading motor driver circuit 113 is fed with the first supply voltage HV, and drives and controls the loading motor 23 so as to slide a loading tray (not illustrated), on which an optical disc is placed. Usable as the loading motor 23 is, for example, a brushed DC motor.
[0049] The focus actuator driver circuit 114 is fed with the second supply voltage LV, and drives and controls the focus actuator 24 , thereby to drive an objective lens of the optical pickup so as to control the focus of the beam spot formed on the optical disc.
[0050] The tracking actuator driver circuit 115 is fed with the second supply voltage LV, and drives and controls the tracking actuator 25 , thereby to drive the objective lens of the optical pickup so as to control the tracking of the beam spot formed on the optical disc.
[0051] The tilt actuator driver circuit 116 is fed with the second supply voltage LV, and drives and controls the tilt actuator 26 , thereby to drive the objective lens of the optical pickup so as to compensate for fluctuations in signal strength ascribable to deformation of the optical disc.
[0052] FIG. 2 is a circuit diagram of an exemplary configuration of the load driving circuit 11 and the fault detection circuit 12 . As to the load driving circuit 11 shown there, it should be understood that, for simplicity′s sake, only the circuitry of and around the output stage for one phase is illustrated with respect to one of the spindle motor driver circuit 111 , the sled motor driver circuit 112 , the loading motor driver circuit 113 , the focus actuator driver circuit 114 , the tracking actuator driver circuit 115 , and the tilt actuator driver circuit 116 .
[0053] The fault detection circuit 12 includes a first overvoltage detector 121 , an undervoltage detector 122 , a second overvoltage detector 123 , and a fault detection signal generator 124 .
[0054] The first overvoltage detector 121 monitors whether or not the first supply voltage HV is higher than an overvoltage detection voltage Vth 1 (for example, Vth 1 =18 V) to generate a first overvoltage detection signal SA. The first overvoltage detection signal SA is, when the first supply voltage HV is lower than the overvoltage detection voltage Vth 1 , at a normal-mode logical level (low level (GND)) and, when the first supply voltage HV is higher than the overvoltage detection voltage Vth 1 , at an abnormal-mode logical level (high level (HV)).
[0055] FIG. 5 is a circuit diagram showing an exemplary configuration of the first overvoltage detector 121 . The first overvoltage detector 121 includes a comparator 121 a which compares the first supply voltage HV fed to its non-inverting input node (+) with the overvoltage detection voltage Vth 1 fed to its inverting input node (−) to generate the first overvoltage detection signal SA. The first power node (high-potential node) of the comparator 121 a is connected to a node to which the first supply voltage HV is applied. The second power node (low-potential node) of the comparator 121 a is connected to a node to which a ground voltage GND is applied.
[0056] The undervoltage detector 122 monitors whether or not the first supply voltage HV is lower than an undervoltage detection voltage Vth 2 (for example, Vth 2 =6 V) to generate an undervoltage detection signal SB. The undervoltage detection signal SB is, when the first supply voltage HV is higher than the undervoltage detection voltage Vth 2 , at a normal-mode logical level (low level (GND)) and, when the first supply voltage HV is lower than the undervoltage detection voltage Vth 2 , at an abnormal-mode logical level (high level (HV)).
[0057] FIG. 6 is a diagram showing an exemplary configuration of the undervoltage detector 122 . The undervoltage detector 122 includes a comparator 122 a which compares the first supply voltage HV fed to its inverting input node (−) with the undervoltage detection voltage Vth 2 fed to its non-inverting input node (+) to generate the undervoltage detection signal SB. The first power node (high-potential node) of the comparator 122 a is connected to the node to which the first supply voltage HV is applied. The second power node (low-potential node) of the comparator 122 a is connected to the node to which the ground voltage GND is applied.
[0058] The second overvoltage detector 123 monitors whether or not the second supply voltage LV is higher than an overvoltage detection voltage Vth 3 (for example, Vth 3 =8.5 V) to generate a second overvoltage detection signal SC. The second overvoltage detection signal SC is, when the second supply voltage LV is lower than the overvoltage detection voltage Vth 3 , at a normal-mode logical level (low level (GND)) and, when the second supply voltage LV is higher than the overvoltage detection voltage Vth 3 , at an abnormal-mode logical level (high level (LV)).
[0059] FIG. 7 is a circuit diagram showing an exemplary configuration of the second overvoltage detector 123 . The second overvoltage detector 123 includes a comparator 123 a which compares the second supply voltage LV fed to its non-inverting input node (+) with the overvoltage detection voltage Vth 3 fed to its inverting input node (−) to generate the second overvoltage detection signal SC. The first power node (high-potential node) of the comparator 123 a is connected to a node to which the second supply voltage LV is applied. The second power node (low-potential node) of the comparator 123 a is connected to the node to which the ground voltage (GND)) is applied.
[0060] The fault detection signal generator 124 monitors the first overvoltage detection signal SA, the undervoltage detection signal SB, and the second overvoltage detection signal SC to generate the fault detection signal 51 . The fault detection signal generator 124 includes a level shifter 124 a and an OR (logical addition) operator 124 b.
[0061] The level shifter 124 a shifts the level of the first overvoltage detection signal SA, which is driven to pulsate between the first supply voltage HV and the ground voltage GND, to generate a (shifted) first overvoltage detection signal SA′, which is driven to pulsate between the second supply voltage LV and the ground voltage GND. Using the level shifter 124 a eliminates the need to give the OR operator 124 b an unnecessarily high withstand voltage.
[0062] FIG. 8 is a circuit diagram showing an exemplary configuration of the level shifter 124 a . The level shifter 124 a of this exemplary configuration includes an N-channel MOS field-effect transistor a 1 , a current source a 2 , and an inverter a 3 . The drain of the transistor a 1 is connected to the node to which the first supply voltage HV is applied. The source of the transistor a 1 is connected, via the current source a 2 , to the node to which the ground voltage GND is applied. The gate of the transistor a 1 is connected to a node to which the first overvoltage detection signal SA is connected. The input node of the inverter a 3 is connected to the source of the transistor a 1 . The output node of the inverter a 3 is connected to the node to which the first overvoltage detection signal SA′ is applied. The first power node (high-potential node) of the inverter a 3 is connected to the node to which the second supply voltage LV is applied. The second power node (low-potential node) of the inverter a 3 is connected to the node to which the ground voltage GND is applied.
[0063] The OR operator 124 b calculates the OR (logical sum) of the first overvoltage detection signal SA′, the undervoltage detection signal SB, and the second overvoltage detection signal SC to generate the fault detection signal S 1 . The fault detection signal S 1 is, when any of the first overvoltage detection signal SA′, the undervoltage detection signal SB, and the second overvoltage detection signal SC is at high level, at high level (LV) and, when those signals are all at low level, at low level (GND).
[0064] The load driving circuit 11 includes a P-channel DMOS field-effect transistor PD 1 , an N-channel DMOS field-effect transistor ND 1 , P-channel MOS field-effect transistors P 0 and P 1 , an N-channel MOS field-effect transistor N 1 , a resistor R 1 , a pre-driver DRV, a buffer BUF, an inverter INV, and a compensated supply voltage generator CVG.
[0065] The source of the transistor PD 1 is connected to the node to which the first supply voltage HV (or the second supply voltage LV) is applied. The drain of the transistor PD 1 is connected to an output node of an output signal OUT. The gate of the transistor PD 1 is connected to the pre-driver DRV. The source of the transistor ND 1 is connected to the node to which the ground voltage GND is applied. The drain of the transistor ND 1 is connected to the output node of the output signal OUT. The gate of the transistor ND 1 is connected to the pre-driver DRV.
[0066] The source of the transistor P 0 is connected to the node to which the first supply voltage HV (or the second supply voltage LV) is applied. The drain of the transistor P 0 is connected to the supply voltage input node of the pre-driver DRV. The gate of the transistor P 0 is connected to the output node of the buffer BUF. The input node of the buffer BUF is connected to a node to which the fault detection signal S 1 is applied. The first end of the resistor R 1 is connected to the supply voltage input node of the pre-driver DRV. The second node of the resistor R 1 is connected to the node to which the ground voltage GND is applied.
[0067] The source of the transistor P 1 is connected to the node to which the first supply voltage HV (or the second supply voltage LV) is applied. The drain of the transistor P 1 is connected to the gate of the transistor PD 1 . The gate of the transistor P 1 is connected to the output node of the inverter INV. The input node of the inverter INV is connected to the node to which the fault detection signal S 1 is applied. The source of the transistor N 1 is connected to the node to which the ground voltage GND is applied. The drain of the transistor N 1 is connected to the gate of the transistor ND 1 . The gate of the transistor N 1 is connected to a node to which the fault detection signal S 1 is applied.
[0068] In the load driving circuit 11 configured as described above, the transistors PD 1 and ND 1 correspond to a push-pull output circuit which, fed with the first supply voltage HV (or the second supply voltage LV), drives a load. More specifically, the transistor PD 1 corresponds to an upper transistor which is connected between the node to which the first supply voltage HV (or the second supply voltage LV) is applied and the output node of the output signal OUT; the transistor ND 1 corresponds to a lower transistor which is connected between the node to which the ground voltage GND is applied and the output node of the output signal OUT.
[0069] The pre-driver DRV is one of internal circuits which operate by being fed with the first supply voltage HV (or the second supply voltage LV), and corresponds to a driving circuit that generates driving signals for the push-pull output circuit (the gate signals of the transistors PD 1 and ND 1 ) according to instructions from the microprocessor 30 .
[0070] The transistor P 0 corresponds to a power switch which connects/disconnects (that is, makes conduct/cuts off) a supply voltage feed line leading to the internal circuits (including the pre-driver DRV) according to the fault detection signal S 1 . When the fault detection signal S 1 is at low level (the normal-mode logical level), the transistor P 0 is turned on to conduct the supply voltage feed line to the internal circuits. On the other hand, when the fault detection signal S 1 is at high level (the abnormal-mode logical level), the transistor P 0 is turned off to disconnect the supply voltage feed line leading to the internal circuits.
[0071] The transistor P 1 corresponds to a first upper switch which, according to the fault detection signal S 1 , connects/disconnects between the gate of the transistor PD 1 and the node to which the first supply voltage HV (or the second supply voltage LV) is applied. When the fault detection signal S 1 is at low level (the normal-mode logical level), the transistor P 1 is turned off to disconnect between the gate of the transistor PD 1 and the node to which the first supply voltage HV (or the second supply voltage LV) is applied. On the other hand, when the fault detection signal S 1 is at high level (the abnormal-mode logical level), the transistor P 1 is turned on to connect between the gate of the transistor PD 1 and the node to which the first supply voltage HV (or the second supply voltage LV) is applied.
[0072] The transistor N 1 corresponds to a first lower switch which, according to the fault detection signal S 1 , connects/disconnects between the gate of the transistor ND 1 and the node to which the ground voltage GND is applied. When the fault detection signal S 1 is at low level (the normal-mode logical level), the transistor N 1 is turned off to disconnect between the gate of the transistor ND 1 and the node to which the ground voltage GND is applied. On the other hand, when the fault detection signal S 1 is at high level (the abnormal-mode logical level), the transistor N 1 is turned on to connect between the gate of the transistor ND 1 and the node to which the ground voltage GND is applied.
[0073] The resistor R 1 corresponds to a pull-down resistor which is connected between the supply voltage input node for the internal circuits and the node to which the ground voltage GND is applied.
[0074] The buffer BUF shifts the level of the fault detection signal S 1 , which is driven to pulsate between the second supply voltage LV and the ground voltage GND, to generate a gate signal G 0 which is driven to pulsate between the first supply voltage HV (or the second supply voltage LV) and a first compensated supply voltage HV′ (or a second compensated supply voltage LV′), and feeds the gate signal G 0 to the gate of the transistor P 0 . The first compensated supply voltage HV′ (or the second compensated supply voltage LV′) is given, for example, a voltage value lower than the first supply voltage HV (or the second supply voltage LV) by a predetermined value α (for example, α=5 V). Using the buffer BUF having a level shifting capability eliminates the need to give the transistor P 0 an unnecessarily high withstand voltage.
[0075] The inverter INV shifts the level of the fault detection signal S 1 , which is driven to pulsate between the second supply voltage LV and the ground voltage GND, and then logically inverts the result to generate a gate voltage G 1 that is driven to pulsate between the first supply voltage HV (or the second supply voltage LV) and the first compensated supply voltage HV′ (or the second compensated supply voltage LV′), and feeds the gate voltage G 1 to the gate of the transistor P 1 . Using the inverter INV having a level shifting capability eliminates the need to give the transistor P 1 an unnecessarily high withstand voltage.
[0076] FIG. 9 is a circuit diagram showing an exemplary configuration of the compensated supply voltage generator CVG. The compensated supply voltage generator CVG of this exemplary configuration includes a P-channel MOS field-effect transistor b 1 , an npn-type bipolar transistor b 2 , a zener diode b 3 , and resistors b 4 and b 5 . The source of the transistor b 1 is connected to a node to which the first compensated supply voltage HV′ (or the second compensated supply voltage LV′) is applied; it is also connected, via the resistor b 4 , to the node to which the first supply voltage HV (or the second supply voltage LV) is applied. The drain of the transistor b 1 is connected to the node to which the ground voltage GND is applied. The gate of the transistor b 1 is connected to the emitter of the transistor b 2 , and is also connected, via the resistor b 5 , to the node to which the ground voltage GND is applied. The collector and the base of the transistor b 2 are both connected to the anode of the zener diode b 3 . The cathode of the zener diode b 3 is connected to the node to which the first supply voltage HV (or the second supply voltage LV) is applied. The compensated supply voltage generator CVG of this exemplary configuration can generate the first compensated supply voltage HV′ (or the second compensated supply voltage LV′) which is lower than the first supply voltage HV (or the second supply voltage LV) by a predetermined value α.
[0077] In the load driving circuit 11 configured as described above, when the fault detection signal S 1 turns to high level (the abnormal-mode logical level), the transistor P 0 is turned off, and the supply voltage feed line leading to the internal circuits including the pre-driver DRV is disconnected. Thus, even when there is a fault (an overvoltage or an undervoltage) in the first supply voltage HV or the second supply voltage LV, the internal circuits are prevented from destruction.
[0078] Incidentally, when the transistor P 0 is turned off and the supply voltage feed line leading to the internal circuits is disconnected, the supply voltage input node for the internal circuits is pulled down, via the resistor R 1 , to the node to which the ground voltage GND is applied. Thus, no indefinite voltage appears at the supply voltage input node for the internal circuits, which are thereby prevented from abnormal operation.
[0079] On the other hand, in the load driving circuit 11 configured as described above, to avoid a drop in power efficiency ascribable to the on-state resistance component across a switch, no switch for connecting/disconnecting is provided in the supply voltage feed line leading to the push-pull output circuit.
[0080] Instead, in the load driving circuit 11 configured as described above, as a means for protecting the transistors PD 1 and ND 1 , the transistors P 1 and N 1 are provided. When the fault detection signal S 1 turns to high level (the abnormal-mode logical level), the transistors P 1 and N 1 are turned on so that the transistors PD 1 and ND 1 both have their gate and source short-circuited together. As a result, the transistors PD 1 and ND 1 no longer receives any voltage between their gate and source. In this way, it is possible to protect the transistors PD 1 and ND 1 without unnecessarily increasing their gate-source withstand voltage. Needless to say, the transistors PD 1 and ND 1 need to be given a source-drain withstand voltage high enough to withstand a fault in the first supply voltage HV (or the second supply voltage LV). Incidentally, when the fault detection signal S 1 turns to high level (the abnormal-mode logical level), the transistors PD 1 and ND 1 are both completely turned off, with the result that the output node of the output signal OUT is left in a floating state (a high-impedance state). FIG. 10 is a timing chart showing an example of the fault protection operation described above, showing, from top, the first supply voltage HV, the fault detection signal S 1 , the gate voltages of the transistors P 1 and N 1 , the gate voltages of the transistors PD 1 and ND 1 , and the output signal OUT.
[0081] Although not illustrated in FIG. 2 , an electrostatic protection diode is commonly connected between the node to which the first supply voltage HV (or the second supply voltage LV) is applied and the node to which the ground voltage GND is applied. The electrostatic protection diode lies outside the scope of the protection operation based on the fault detection signal S 1 , and therefore needs to be implemented with a device that has a sufficiently high withstand voltage.
[0082] FIG. 3 is a circuit diagram showing a modified example of the load driving circuit 11 . As shown in FIG. 3 , the load driving circuit 11 may be so configured as to have analog switches SW 1 and SW 2 connected to the gates of the transistors PD 1 and ND 1 respectively.
[0083] The analog switch SW 1 corresponds to a second upper switch which, according to the fault detection signal S 1 , connects/disconnects between the gate of the transistor PD 1 and the pre-driver DRV. When the fault detection signal S 1 is at low level (the normal-mode logical level), the analog switch SW 1 is turned on to connect between the gate of the transistor PD 1 and the pre-driver DRV. On the other hand, when the fault detection signal S 1 is at high level (the abnormal-mode logical level), the analog switch SW 1 is turned off to disconnect between the gate of the transistor PD 1 and the pre-driver DRV. Providing the analog switch SW 1 makes it possible to more reliably keep the gate of the transistor PD 1 at the first supply voltage HV (or the second supply voltage LV) when the fault detection signal S 1 turns to high level (the abnormal-mode logical level).
[0084] The analog switch SW 2 corresponds to a second lower switch which, according to the fault detection signal S 1 , connects/disconnects between the gate of the transistor ND 1 and the pre-driver DRV. When the fault detection signal S 1 is at low level (the normal-mode logical level), the analog switch SW 2 is turned on to connect between the gate of the transistor ND 1 and the pre-driver DRV. On the other hand, when the fault detection signal S 1 is at high level (the abnormal-mode logical level), the analog switch SW 2 is turned off to disconnect between the gate of the transistor ND 1 and the pre-driver DRV. Providing the analog switch SW 2 makes it possible to more reliably keep the gate of the transistor ND 1 at the ground voltage GND when the fault detection signal S 1 turns to high level (the abnormal-mode logical level).
[0085] As described above, a motor driver IC 10 adopting the configuration shown in FIG. 2 or 3 eliminates the need, in order to cope with overvoltage destruction testing and destructive testing in which supply voltages for two systems are connected the wrong way around (so-called cross connection testing), to give the transistors PD 1 and ND 1 an unnecessarily increased withstand voltage, or to connect an additional component externally to the motor driver IC 10 . This contributes to reducing the chip area and reducing the cost of target products.
[0086] For example, in a case where overvoltage destruction testing is conducted in which the first supply voltage HV or the second supply voltage LV is intentionally brought into an overvoltage state, while the first supply voltage HV or the second supply voltage LV is held in an overvoltage state, the first overvoltage detection signal SA or the second overvoltage detection signal SC remains at high level, and this causes the fault detection signal S 1 to turn to high level (the abnormal-mode logical level) and thereby activates the fault protection operation described above (see FIG. 10 ). The IC is thus prevented from smoking or destruction.
[0087] As discussed above, according to the protection technology described above, with respect to a device that handles a small signal, it can be protected from destruction by turning off a switch in a power supply line and, with respect to an output device that cannot be protected in that way, it can be protected from destruction through the introduction of a switch for turning its gate off That is, as circuit elements for realizing the protection technology described above, both a gate-off switch against destruction of an output device and a switch for disconnecting a power supply line are both essential. The reason that a power supply line connected to an output device is not disconnected is to avoid an apparent increase in the on-state resistance of the output device which would result from the insertion of the switch.
[0088] On the other hand, in a case where destructive testing is conducted in which the first and second supply voltages LH and LV are connected the wrong way around (so-called cross connection testing), the undervoltage detection signal SB or the second overvoltage detection signal SC turns to high level and thereby activates the protection operation described above. The IC is thus prevented from smoking or destruction.
(Desktop PC)
[0089] FIG. 11 is an external view of a desktop personal computer (PC) incorporating the optical disc drive 1 . The desktop PC X of this exemplary configuration includes a cabinet X 10 , a liquid crystal display monitor X 20 , a keyboard X 30 , and a mouse X 40 .
[0090] The cabinet X 10 accommodates a central processing unit (CPU) X 11 , a memory X 12 , an optical drive X 13 , a hard disk drive X 14 , etc.
[0091] The CPU X 11 executes an operating system and various application programs stored on the hard disk drive X 14 , and thereby controls the operation of the desktop PC X in an integrated fashion.
[0092] The memory X 12 is used as a working area (for example, an area where task data is stored during execution of a program) by the CPU X 11 .
[0093] The optical drive X 13 reads and writes optical discs. Examples of optical discs include CDs (compact discs), DVDs (digital versatile discs), and BDs (Blu-ray discs). As the optical drive X 13 , the optical disc drive 1 described previously can suitably be used.
[0094] The hard disk drive X 14 is a type of large-capacity auxiliary storage device that stores programs and data on a non-volatile basis by use of a magnetic disk hermetically sealed inside a housing.
[0095] The liquid crystal display monitor X 20 outputs video based on instructions from the CPU X 11 .
[0096] The keyboard X 30 and the mouse X 40 are each a type of human interface device that accepts user operation.
MODIFICATIONS AND VARIATIONS
[0097] Although the embodiment described above deals with, as an example, a configuration where the present invention is applied to a motor driver IC 10 , this is not meant to limit the scope of application of the present invention; the present invention finds wide application in load driving devices in general, such as switching regulator ICs like the one shown in FIG. 4 .
[0098] FIG. 4 is a circuit diagram showing an exemplary configuration of a switching regulator IC to which the present invention is applicable. The switching regulator IC 40 of this exemplary configuration is a semiconductor integrated circuit device including a P-channel MOS field-effect transistor 41 , a rectification diode 42 , a switch controller 43 , an overvoltage protector 44 , and a power switch 45 ; it further has, externally connected to it as discrete devices constituting an output stage, a coil L 11 , a capacitor C 11 , and resistors R 11 and R 12 . Although in this exemplary configuration, the output stage is configured as a step-down type, this is not meant to limit the configuration of the output stage; it may instead be of a step-up type or a step-up and—down type.
[0099] In the switching regulator IC 40 of this exemplary configuration, the transistor 41 corresponds to the transistor PD 1 in FIG. 2 , and the rectification diode 42 corresponds to the transistor ND 1 in FIG. 2 . The rectification diode 42 may be replaced with a synchronous-rectification transistor. The switch controller 43 corresponds to the pre-driver DRV (an internal circuit) in FIG. 2 , and the overvoltage protector 44 corresponds to the fault detection circuit 12 in FIG. 2 . The power switch 45 corresponds to the transistor P 0 in FIG. 2 . Although not explicitly shown in FIG. 4 , a device corresponding to the transistor P 1 in FIG. 2 may be provided, for example, between the gate and the source of the transistor 41 .
[0100] Although the embodiment described above deals with, as an example, a configuration where the motor driver IC 10 is fed with supply voltages (HV and LV) for two systems, this is not meant to limit the present invention; even in cases where it is fed with supply voltages for three or more systems, it is possible to flexibly cope with them by providing an overvoltage detector and an undervoltage detector for each system and performing level shifting so as to adapt the signal level of a fault detection signal for each load driving circuit.
[0101] As discussed above, the present invention may be implemented in any other manners than specifically described by way of an embodiment above, with many modifications made without departing from the spirit of the present invention. That is, it is to be understood that the embodiment described above is in every way illustrative and not restrictive. The technical scope of the present invention is defined not by the description of the embodiment above but by the scope of the appended claims, and is to be understood to encompass any modifications made in the sense and scope equivalent to those of the claims.
INDUSTRIAL APPLICABILITY
[0102] The present invention contributes to enhancing the reliability of load driving devices.
LIST OF REFERENCE SIGNS
[0000]
1 optical disc drive
10 load driving device (motor driver IC)
11 load driving circuit
111 spindle motor driver circuit
112 sled motor driver circuit
113 loading motor driver circuit
114 focus actuator driver circuit
115 tracking actuator driver circuit
116 tilt actuator driver circuit
12 fault detection circuit
121 first overvoltage detector
121 a comparator
122 undervoltage detector
122 a comparator
123 second overvoltage detector
123 a comparator
124 fault detection signal generator
124 a level shifter
a 1 N-channel MOS field-effect transistor
a 2 current source
a 3 inverter
124 b OR operator
20 load (motor/actuator)
21 spindle motor
22 sled motor
23 loading motor
24 focus actuator
25 tracking actuator
26 tilt actuator
30 microprocessor
40 switching regulator IC
41 P-channel MOS field-effect transistor
42 rectification diode
43 switch controller (internal circuit)
44 overvoltage protector (fault detection circuit)
45 power switch
PD 1 P-channel DMOS field-effect transistor
ND 1 N-channel DMOS field-effect transistor
P 0 , P 1 P-channel MOS field-effect transistor
N 1 N-channel MOS field-effect transistor
R 1 resistor
DRV pre-driver
BUF buffer (with a level shifting capability)
INV inverter (with a level shifting capability)
CVG compensated supply voltage generator
b 1 P-channel MOS field-effect transistor
b 2 npn-type bipolar transistor
b 3 zener diode
b 4 , b 5 resistor
SW 1 , SW 2 analog switch
L 11 coil
C 11 capacitor
R 11 , R 12 resistor
X desktop PC
X 10 cabinet
X 11 CPU
X 12 memory
X 13 optical drive
X 14 hard disk drive
X 20 liquid crystal display monitor
X 30 keyboard
X 40 mouse | A load driving device according to the present invention has: an internal circuit (DRV) that operates in response to the supply of a power supply voltage (HV or LV); an output circuit (PD 1 and PD 2 ) for driving a load in response to the supply of the power supply voltage (HV or LV); an abnormality detection circuit ( 12 ) for monitoring the power supply voltage (HV or LV) and generating an abnormality detection signal (S 1 ); and a power supply switch (P 0 ) for, according to the abnormality detection signal (S 1 ), conducting or cutting off a power-supply-voltage supply line to the internal circuit (DRV). | 7 |
BACKGROUND OF THE INVENTION
For many years spine fin tubing has been used in heat exchange structures for air conditioners. In such heat exchangers the spine fin ribbon is wrapped about the evaporator tubing in a very compact fashion; that is, the spine fin ribbon is wound so that adjacent passes of ribbon are in contact and the fingers or spines are very closely spaced. With such a construction the spines or fingers provide a very large total surface area for heat transfer.
Despite the successful use of spine fin tubing in air conditioners for many years, such heat exchange structures were not used in refrigerator evaporators. It has been the belief of many experienced practitioners that spine fin materials are not suitable for use in refrigerator evaporators. One basis for the belief was that the frost build up in a refrigerator evaporator quickly would render the spine fin ineffective as a heat transfer structure. In addition, it was believed that spine fin structures, as used in air conditioners, were too delicate to withstand the handling involved in manufacturing and installing refrigerator evaporators. On the other hand it was believed that, if the size of the spines were increased sufficiently to withstand the rigors of manufacturing, then the evaporator would not have sufficient heat exchange capacity to be effective with the stringent size limitations normally imposed upon such evaporators.
Co-pending U.S. Pat. No. 5,067,322 of David G. Beers issued Nov. 26, 1991 and assigned to General Electric Company, assignee of the present application, discloses a refrigerator evaporator incorporating a ribbon of spine fin material wound about the outer periphery of the evaporator tubing with a series of fingers extending perpendicularly outward of the tube along each edge of the ribbon, and is incorporated herein by reference.
However, it is desirable to further optimize the heat transfer between the spine fin material and the air passing over the evaporator.
Accordingly, it is an object of this invention to provide an improved refrigerator with an evaporator incorporating a spine fin heat exchange structure of improved heat transfer capability.
It is another object of the present invention to provide an improved structure in which the distal end portions of the spine fin fingers extend perpendicularly of the direction of air flow across the elongated evaporator tubing.
It is still another object of this invention to provide such an improved structure in which a spine fin ribbon has a base wrapped about the evaporator tubing in an open spiral with fingers extending outwardly of said evaporator tubing along each edge of the base and with the distal ends of the fingers bent to extend generally perpendicular to the root portions of the fins.
It is yet another object of this invention to provide such an improved structure in which the finger distal ends all extend in the same direction.
It is yet another object of this invention to provide such an improved structure in which the finger distal ends overlie the corresponding portions of the spine fin base.
It is still another object of this invention to provide such an improved structure in which the finger distal ends extend axially of the tubing away from the corresponding portion of the spine fin base.
Further objects and advantages of the present invention will be apparent from the following description and features of novelty which characterize the invention will be pointed out in the claims attached to and forming a part of this specification.
SUMMARY OF THE INVENTION
In accordance with one form of this invention a refrigerator has a compartment to be refrigerated and an evaporator normally operated at frost producing temperature to refrigerate the compartment. The evaporator includes elongated tubing to carry refrigerant and an elongated spine fin ribbon wrapped in intimate heat transfer contact about the tubing in an open spiral configuration. The ribbon is formed with a base having a substantially continuous series of fingers projecting outwardly of the tubing along each lateral edge of the base. The distal ends of the fingers are bent to extend generally perpendicular to the root portions of the fingers and lie in a direction perpendicular to the direction of air flow over the evaporator tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary cross-sectional side elevation view of a refrigerator incorporating one embodiment of the present invention;
FIG. 2 is a cross-sectional view taken laterally of the evaporator tubing incorporated in FIG. 1;
FIG. 3 is a fragmentary cross-sectional view taken longitudinally of the tube of FIG. 1;
FIG. 4 is a fragmentary perspective view of the tube of FIG. 1, partly broken away;
FIG. 5 is a cross-sectional view of the spine fin ribbon incorporated in the evaporator tubing assembly of FIGS. 2-4;
FIG. 6 is a cross-sectional view of another form of spine fin ribbon useful in the invention;
FIG. 7 is a cross-sectional view of yet another form of spine fin ribbon useful in the invention;
FIG. 8 is a cross-sectional view of still another form of spine fin ribbon useful in the invention;
FIG. 9 is a cross-sectional view of another form of spine fin ribbon useful in the invention;
FIG. 10 is a cross-sectional view of still another form of spine fin ribbon useful in the invention;
FIG. 11 is a cross-sectional view of yet another form of spine fin ribbon useful in the invention, and
FIG. 12 is a cross-sectional view of another form of spine fin ribbon useful in the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a refrigerator 10 includes an outer cabinet 12 containing a freezer compartment 14 and fresh food compartment 16. The freezer compartment 14 is maintained at sub-freezing temperatures and the fresh food compartment 16 at above freezing, food preserving temperatures by circulating air through these compartments and over an evaporator 18 positioned in a vertically disposed evaporator chamber 20 positioned behind the freezer compartment 14 and separated from it by wall structure 22. More specifically, a fan 24 positioned in the upper portion of the evaporator chamber or compartment 20 discharges air through openings 26 in the wall 22 into the freezer compartment 14 and through a passage, partially shown at 28, to the fresh food compartment 16. The fan also draws air from within the freezer compartment 14 and fresh food compartment 16 back into the evaporator compartment 20 and over the evaporator. The return air from the freezer compartment flows through a passage partially shown at 30 while the air returned from the fresh food compartment flows through passage 32. The freezer compartment 14 is maintained below freezing while the fresh food compartment 16 is maintained above freezing by an appropriate division of the air discharged from the evaporator compartment 20, with the majority of the air going to the freezer compartment 14 and a smaller portion of the air going to the fresh food compartment 16.
In order to maintain the freezer compartment 14 at sub-freezing temperatures, it is necessary that the evaporator 18 operate at below freezing temperatures, with the result that moisture contained in the return air flowing through the evaporator chamber 20 collects on the outer surfaces of the evaporator in the form of frost. Periodically this accumulated frost is removed from the evaporator surfaces by energizing a heater 34 positioned in radiant and convection heating relationship with the evaporator surfaces.
Refrigerator evaporators transfer heat from the air passing over the outside of the evaporator surface to the refrigerant flowing through the inside of the evaporator so as to cool the air. A typical refrigerator evaporator consists essentially of an elongated tubing or tube carrying refrigerant which is bent or formed into either a serpentine or a spiral configuration in order to fit in a more confined space and, thus, take up less room in the refrigerated compartments of a refrigerator. In order to enhance the heat transfer characteristic of the evaporator it is well known to provide some kind of fins extending outwardly from the tube to increase the surface area for transfer. With refrigerator evaporators, particularly those which provide cooling for freezing compartments, it is necessary for the evaporator structure to provide effective heat transfer even though a considerable body of frost has built up around the evaporator tubing. To this end, the greater the space provided between adjacent fins or adjacent rows of fins of a spine fin structure the longer effective air flow over the evaporator will take place. On the other hand, larger fin spacings reduce the number of fins and the total available heat transfer surface area. Thus, it is advantageous to enhance the effectiveness of heat transfer between the air and the fins.
In the illustrative evaporator 18, a tube 36 is formed and disposed in a fashion well known in the art. That is, the tube 36 is bent in the form of serpentine to provide a plurality of elongated horizontal conduit passes disposed in a vertical spaced arrangement connected by return bends. The overall layout of the evaporator 18 is a generally rectangular construction with the various elongated passes of the tube 36 supported in spaced relationship on opposed frame members, one of which is shown at 38, at opposite sides of the evaporator 18. The frame members 38 mount the evaporator 18 in a generally vertical position within the evaporator chamber compartment 20 but slightly angled with respect to the vertical to more fully expose the horizontal passes of the tube 36 to the return air flowing upwardly through the evaporator compartment 20. With this arrangement the air flows perpendicularly across the elongated section of evaporator tubing.
The radiant heater 34 is periodically energized to warm the evaporator surfaces to defrosting temperatures. This heater conveniently may be of the type disclosed in co-pending U.S. Pat. No. 5,067,322 of David G. Beers et al, assigned to General Electric Company, assignee of the present invention.
As best seen in FIGS. 2, 3 and 4, the evaporator 18 includes an elongated spine fin ribbon 40 wound or wrapped about the outer surface of tube 36 in an open spiral configuration. That is, each pass (one circumferential circuit around the tube) of the ribbon 40 is spaced apart from the longitudinally adjacent passes of the ribbon. More specifically, the ribbon includes an elongated base 42 and a plurality of spines or fingers 44. The fingers 44 are arranged in rows 46 and 48 along the lateral edges of the base 42. Each of the rows 46 and 48 is formed of a substantially continuous series of fingers 44. That is the fingers are formed adjacent to each other without significant spacings between them where they join the base 42. When wrapped around the tube 36, as shown in FIGS. 2-4, the fingers extend outwardly from the outer surface of the tube 36 adjacent the lateral edges of the ribbon base 42 and, preferably, they are disposed generally perpendicular to the outer surface tube 36.
The distal end portion of each finger is bent generally perpendicular to the root portion of the finger and thus is disposed generally perpendicular to the direction of the flow of air passing over the evaporator as result of the operation of fan 24. Viewing FIG. 4, it will be seen that the distal end portions 50 of the fingers 44 in row 46 are bent generally perpendicularly to the right of the root portion 54 while the distal end portions of fingers 44 in row 48 are bent generally perpendicularly to the left of the root portion 56. This results in the end portions overlying the ribbon base 42. This provides a compact construction and enables the ribbon to be wound in a tight spiral, that is with minimal space along the tubing between adjacent passes of ribbon.
Preferably, the end portions of the fingers are bent substantially perpendicularly to the corresponding root portions of the fingers. Thus, the end portions extend generally perpendicular to the basic direction of flow of return air flowing over the evaporator. However, it will be understood that the fin ends do not have to be bent exactly perpendicularly and that some fins and fin ends may be distorted as a result of the handling needed to form an evaporator and to mount it in a refrigerator.
When the evaporator tube and ribbon are fully assembled or formed, the bent fin end portions lie in an annular cylinder which surrounds and has the same axis as the tube. It will be understood that an annular cylinder is a hollow cylinder having a cross-section which is in the form of an annular.
Different configurations of ribbon finger distal end portion arrangements are possible within the scope of the invention in order to customize the evaporator tubing assembly to the operating characteristics of the particular refrigerator. Additional illustrative configurations of the spine fin ribbon are shown in FIG's 6-8, inclusive with like portions being identified with corresponding reference numerals but with the addition of letters a, b and c to distinguish the particular configurations. In FIG. 6 all the distal end portion 50a and 52a are bent to extend to the left (as seen in the FIG. 6) so that end portions 52a extend over the base 42a of the ribbon 40. In FIG. 7 the distal end portions are arranged in the opposite configuration than in FIG. 6, that is, the end portions 50b and 52b extend to the right (as seen in FIG. 7). With this configuration, end portions 50b overlap base 42b and end portions 52b extend outwardly of the corresponding edge of the base 42b. In FIG. 8 the distal ends 50c of fingers 44c in row 46c extend to the left while the end portions 52c of fingers 44c in row 48c extend to the right. This provides a structure in which the distal end portions extend outwardly of the corresponding edge of the ribbon base 42c. This positions both the base and the distal end portions perpendicular to the direction of the air flow and open to contact by the air but requires that the ribbon be wound with a wider spacing to assure that the end portions of adjacent passes of ribbon do not overlap.
FIG's 9-12, inclusive illustrate additional forms of ribbon which are useful in forming spine fin evaporators incorporating the present invention. Referring particularly to FIG. 9, a ribbon 60 includes an elongated base 62 and a plurality of fingers 64 and 66 arranged in rows extending outwardly from the opposite sides of the base 62. The fingers in each row are formed as a substantially continuous series of fingers, with successive fingers being formed adjacent to each other without significant spacings between them where they join the base 62. When wrapped around a tube the fingers extend outwardly of the tube but are canted or slanted slightly from the perpendicular away from the base, as illustrated in FIG. 9. The root portions 68 of the fingers 64 are longer than the root portions 70 of the fingers 66. The distal end portions 72 of the fingers 64 are bent substantially at right angles to the right, as seen in FIG. 9, while the distal end portions 74 of the fingers 66 are bent to the left. The distal end portions are long enough to extend substantially across the base 62 in overlapping fashion. In the additional ribbon forms illustrated in FIG's 10-12, like components are identified with like reference numerals, but with a, b, and c subscripts, respectively, to distinguish between the different configurations. In FIG. 10 both the distal end portions 72a and 74a are bent to extend to the right so that the closer end portions 74a are positioned over the base 62a and the more remote end portions 72a project away from the base. In FIG. 12 all the end portions 72c and 74c are bent to extend to the left so that the closer end portions 74c project away from the base 62c and the more remote end portions 72c overlie the base. In FIG. 11 all of the end portions 72b and 74b are bent outwardly so that they project away from the base 62b.
Referring to FIG's 9-12, inclusive, the configurations of FIG's 9, 10 and 12 provide the most compact wrap, that is, adjacent passes of ribbon can be wound very close together, and the resulting composite evaporator tubing is resistant to damage during handling. The configuration of FIG. 11 is easier to manufacture, however, the ribbon cannot be wrapped as compactly. It will be understood that the invention is not limited by the particular configurations shown . For example, in each of FIG's 9-12, the left hand root portions are longer than the right hand portions. The reverse also can be the case, that is, the left hand root portions can be shorter than the right hand portions.
While there has been shown and described what is presently considered to be the preferred embodiments of the present invention, it is to be understood that the invention is not limited thereto, and it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of invention. | A refrigerator has a compartment to be refrigerated and a refrigerant evaporator normally operable at frost producing temperatures to refrigerate the compartment. The evaporator includes an elongated tube to receive refrigerant with an elongated spine fin ribbon of heat exchange material including an elongated base wound in an open spiral about and in intimate heat exchange contact with the tube. A continuous series of fingers project outwardly of the tube along each edge of the base and the distal ends of the fingers are bent to extend generally perpendicular to the root portions of the fingers. | 5 |
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2012/000919, filed on Mar. 2, 2012, which claims the benefit of priority of Ser. No. DE 10 2011 005 041.8, filed on Mar. 3, 2011 in Germany, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
There are already known portable power tools that have a coupling device, which can be coupled to a power-tool parting device that has a cutting strand and a guide unit for guiding the cutting strand.
SUMMARY
The disclosure is based on a portable power tool having at least one coupling device, which can be coupled to a power-tool parting device that has at least one cutting strand and at least one guide unit for guiding the cutting strand.
It is proposed that the portable power tool comprise at least one stowage device, which is provided to stow the power-tool parting device, at least when coupled to the coupling device. A “portable power tool” is to be understood here to mean, in particular, a power tool, in particular a hand-held power tool, that can be transported by an operator without the use of a transport machine. The portable power tool has, in particular, a mass of less than 40 kg, preferably less than 10 kg, and particularly preferably less than 5 kg. A “coupling device” is to be understood here to mean, in particular, a device provided to operatively connect the power-tool parting device to the portable power tool, by means of a positive and/or non-positive connection, for the purpose of working a workpiece. In particular, when the coupling device has been coupled to the power-tool parting device and the portable power tool is in an operating state, forces and/or torques can be transmitted from the drive unit of the portable power tool to the power-tool parting device, for the purpose of driving the cutting strand. The coupling device is therefore preferably realized as a tool receiver. The expression “provided to” is intended here to define, in particular, specially configured and/or specially equipped. The term “drive unit” is intended here to define, in particular, a unit provided to generate forces and/or torques for driving the cutting strand. Preferably, for the purpose of generating forces and/or torques by means of the drive unit, thermal energy, chemical energy and/or electrical energy is converted into energy of motion. In particular, the drive unit is realized such that it can be directly and/or indirectly coupled to the cutting strand. Particularly preferably, the drive unit comprises at least one rotor that has an armature shaft, and at least one stator. Preferably, the drive unit is realized as an electric motor. It is also conceivable, however, for the drive unit to be of another design, considered appropriate by persons skilled in the art.
A “cutting strand” is to be understood here to mean, in particular, a unit provided to locally undo an atomic coherence of a workpiece to be worked, in particular by means of a mechanical parting-off and/or by means of a mechanical removal of material particles of the workpiece. Preferably, the cutting strand is provided to separate the workpiece into at least two parts that are physically separate from each other, and/or to part off and/or remove, at least partially, material particles of the workpiece, starting from a surface of the workpiece. Particularly preferably, the cutting strand, in at least one operating state, is moved in a revolving manner, in particular along a circumference of the guide unit. A “guide unit” is to be understood here to mean, in particular, a unit provided to exert a constraining force upon the cutting strand, at least along a direction perpendicular to a cutting direction of the cutting strand, in order to define a possibility for movement of the cutting strand along the cutting direction. Preferably, the guide unit has at least one guide element, in particular a guide groove, by which the cutting strand is guided. Preferably, the cutting strand, as viewed in a cutting plane, is guided by the guide unit along an entire circumference of the guide unit, by means of the guide element, in particular the guide groove. Preferably, the guide unit is realized as a guide bar. The term “guide bar” is intended here to define, in particular, a geometric form that, as viewed in the cutting plane, has a fully closed outer contour, comprising at least two straight lines that are parallel to each other and at least two connecting portions, in particular arcs, that each interconnect mutually facing ends of the straight lines. The guide unit therefore has a geometric shape that, as viewed in the cutting plane, is composed of a rectangle and at least two circle sectors disposed on opposing sides of the rectangle.
The term “cutting plane” is intended here to define, in particular, a plane in which the cutting strand, in at least one operating state, is moved, relative to the guide unit, along a circumference of the guide unit, in at least two mutually opposite cutting directions. Preferably, during working of a workpiece, the cutting plane is aligned at least substantially transversely in relation to a workpiece surface that is to be worked. “At least substantially transversely” is to be understood here to mean, in particular, an alignment of a plane and/or of a direction, relative to a further plane and/or a further direction, that preferably deviates from a parallel alignment of the plane and/or of the direction, relative to the further plane and/or the further direction. It is also conceivable, however, for the cutting plane, during working of a workpiece, to be aligned at least substantially parallelwise in relation to a workpiece surface that is to be worked, in particular if the cutting strand is realized as an abrasive. “At least substantially parallelwise” is to be understood here to mean, in particular, an alignment of a direction relative to a reference direction, in particular in one plane, the direction deviating from the reference direction by, in particular, less than 8°, advantageously less than 5°, and particularly advantageously less than 2°. A “cutting direction” is to be understood here to mean, in particular, a direction along which the cutting strand is moved, in at least one operating state, as a result of a driving force and/or a driving torque, in particular in the guide unit, for the purpose of generating a cutting clearance and/or parting-off and/or removing material particles of a workpiece that is to be worked. Preferably, the cutting strand, when in an operating state, is moved, relative to the guide unit, along the cutting direction.
The cutting strand and the guide unit preferably together constitute a closed system. The term “closed system” is intended here to define, in particular, a system comprising at least two components that, by means of combined action, when the system has been demounted from a system such as, for example, a power tool, that is of a higher order than the system, maintain a functionality and/or are inseparably connected to each other when in the demounted state. Preferably, the at least two components of the closed system are connected to each other so as to be at least substantially inseparable by an operator. “At least substantially inseparable” is to be understood here to mean, in particular, a connection of at least two components that can be separated from each other only with the aid of parting tools such as, for example, a saw, in particular a mechanical saw, etc. and/or chemical parting means such as, for example, solvents. A “stowage device” is to be understood here to mean, in particular, a device provided to stow the power-tool parting device, when coupled to the coupling device, the power-tool parting device being covered by components of the stowage device and/or of the power-tool housing of the portable power tool. The term “covered” is intended here to define, in particular, a disposition of the power-tool parting device, when the power-tool parting device is in a stowed state, relative to components of the stowage device and/or of the power-tool housing, a total extent of the power-tool parting device, along at least a direction running in the cutting plane, being less than an extent of components of the stowage device and/or of the power-tool housing along the same direction. In particular, the power-tool parting device, when in a stowed state, relative to a total surface are of the power-tool parting device, as viewed in the cutting plane, is more than 20%, preferably more than 30%, and particularly preferably more than 50% covered by components of the stowage device and or of the power-tool housing. Preferably, when the power-tool parting device is in a stowed state, operator contact with cutting elements of the cutting strand can be prevented insofar as possible. When the power-tool parting device is in a stowed state, the cutting elements of the cutting strand are preferably disposed so as to be at least substantially non-contactable by an operator, at least in a partial region of the power-tool parting device. Particularly preferably, operation, in particular a revolving motion of the cutting strand in the guide unit, is prevented when the power-tool parting device is in a stowed state. Preferably, when the power-tool parting device is in a stowed state, it is not possible to perform work on a workpiece by means of the power-tool parting device. Advantageously, the design according to the disclosure makes it possible to achieve a high degree of protection for an operator against injury, when the power-tool parting device is in a stowed state in the stowage device. Moreover, advantageously, a compact portable power tool can be achieved.
It is furthermore proposed that the portable power tool comprise a power-tool housing, having at least one side wall that faces toward the stowage device and that, together with a tool covering element of the stowage device, delimits a receiving opening of the stowage device in which the power-tool parting device can be stowed. Preferably, the power-tool parting device, when swiveled into the receiving opening, is disposed, at least in a partial region, as viewed along a direction running at least substantially perpendicularly in relation to the cutting plane of the cutting strand, between the power-tool housing and the tool covering element. Particularly preferably, the power-tool parting device, when swiveled into the receiving opening, as viewed along the direction running at least substantially perpendicularly in relation to the cutting plane, is covered on one side by the power-tool housing and on a further side by the tool covering element. Preferably, the power-tool parting device, when swiveled into the receiving opening, is covered on at least three sides by the power-tool housing and/or the tool covering element. Advantageously, safe stowage of the power-tool parting device can be achieved.
Advantageously, the tool covering element is at least partially integral with the power-tool housing. “Integral with” is to be understood to mean, in particular, connected at least in a materially bonded manner, for example by a welding process, an adhesive process, an injection process and/or another process considered appropriate by persons skilled in the art, and/or, advantageously, formed in one piece such as, for example, by being produced from a casting and/or by being produced in a single or multi-component injection process and, advantageously, from a single blank. Advantageously, it is possible to achieve assembly work in assembling of the portable power tool.
It is additionally proposed that the coupling device be mounted so as to be movable relative to the power-tool housing, at least when coupled to the power-tool parting device. The expression “mounted so as to be movable” is intended here to define, in particular, a mounting of the coupling device on the portable power tool, at least when coupled to the power-tool parting device, the coupling device, in particular decoupled from an elastic deformation of the coupling device, having a capability to move along at least a travel distance greater than 1 mm, preferably greater than 10 mm, and particularly preferably greater than 50 mm, and/or a capability to move about at least one axis by an angle greater than 10°, preferably greater than 45°, and particularly preferably greater than 60°. Particularly preferably, the coupling device has a capability to move along at least one travel distance and/or about one axis that is independent of a pure closing movement of the coupling device for the purpose of operatively connecting the power-tool parting device to the portable power tool, and/or of an opening movement of the coupling device for the purpose of releasing the operative connection of the power-tool parting device to the portable power tool. Advantageously, by means of the design according to the disclosure, the coupling device can be moved, for example translationally and/or rotationally, into a position suitable for performing work on a workpiece. Advantageously, therefore, a high degree of flexibility can be achieved in working of a workpiece.
Preferably, the coupling device is mounted such that it can be swiveled, at least relative to the power-tool housing. Preferably, the power-tool parting device, when coupled to the coupling device, can be swiveled, about a swivel axis running at least substantially perpendicularly in relation to the cutting plane of the cutting strand, into the receiving opening of the stowage device, by means of the coupling device. It is also conceivable, however, for the coupling device, alternatively or additionally, to be mounted such that it can be swiveled, relative to the power-tool housing, abut another swivel axis, considered appropriate by persons skilled in the art. Advantageously, in the case of the portable power tool, it is possible to achieve a pocket-knife principle for stowage of the power-tool parting device. When the power-tool parting device is in a in-in state therefore, the cutting elements of the cutting strand of the power-tool parting device can advantageously be covered, at least partially, by components of the stowage device and/or of the power-tool housing.
It is additionally proposed that the portable power tool at least one drive unit and at least one open-loop and/or closed-loop control unit, which is provided to control the drive unit, by open-loop and/or closed-loop control, in dependence on a angular position of the coupling device, relative to the power-tool housing of the portable power tool. An “open-loop and/or closed-loop control unit” is to be understood to mean, in particular, a unit having at least one control device. A “control device” is to be understood to mean, in particular, a unit having at least one processor unit and having at least one memory unit, and having an operating program stored in the memory unit. Particularly preferably, a transmission of a driving torque from the drive unit to the cutting strand is interrupted as soon as the coupling device is swiveled about the swivel axis. Preferably, a supply of energy to the drive unit is prevented, by means of the open-loop and/or closed-loop control unit, when the power-tool parting device is in a in-in state, in order to prevent a driving torque of the drive unit and/or of the transmission unit from being transmitted to the cutting strand. It is also conceivable, however, for the transmission of a driving torque from the drive unit to the cutting strand to be interrupted by means of a mechanical unit. Advantageously, it is possible to achieve a high degree of operating comfort for an operator.
Advantageously, the portable power tool has at least one locking unit, which is provided to fix the coupling device, at least when coupled to the power-tool parting device, in an angular position relative to the power-tool housing. The coupling device can thus advantageously be fixed, by an operator, in a required position relative to the power-tool housing. In addition, advantageously, work can be performed on a workpiece in various angular positions of the coupling device relative to the power-tool housing.
The disclosure is additionally based on a power-tool parting device for a portable power tool according to the disclosure, having at least one guide unit and at least one cutting strand, which together constitute a closed system. Advantageously, it is possible to achieve a versatile tool for performing work on workpieces.
The disclosure is furthermore based on a power-tool system having at least one portable power tool according to the disclosure and having at least one power-tool parting device according to the disclosure. Particularly preferably, the power-tool parting device, when coupled to the coupling device, can be swiveled, about a swivel axis running at least substantially perpendicularly in relation to a cutting plane of the cutting strand, into the receiving opening of the stowage device, by means of the coupling device. Through simple design means, a stowage device for secure stowage of the power-tool parting device can be achieved.
The power-tool parting device according to the disclosure and/or the power tool according to the disclosure are not intended in this case to be limited to the application and embodiment described above. In particular, the power-tool parting device according to the disclosure and/or the power tool according to the disclosure may have individual elements, components and units that differ in number from the number stated herein, in order to fulfill a principle of function described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages are given by the following description of the drawing. The drawing shows an exemplary embodiment of the disclosure. The drawing, the description and the claims contain numerous features in combination. Persons skilled in the art will also expediently consider the features individually and combine them to create appropriate further combinations.
In the drawing:
FIG. 1 shows a portable power tool according to the disclosure, having a power-tool parting device according to the disclosure, in a schematic representation, FIG. 2 shows the power tool according to the disclosure, during an operation of swiveling the power-tool parting device according to the disclosure into a receiving opening of a stowage device of the power tool according to the disclosure, in a schematic representation, FIG. 3 shows the power-tool parting device according to the disclosure, coupled to a coupling device, in a relative angular position in relation to a power-tool housing of the power tool according to the disclosure, in a schematic representation, FIG. 4 shows a detail view of a transmission unit of the power tool according to the disclosure, in a schematic representation, FIG. 5 shows a detail view of the power-tool parting device according to the disclosure, in a schematic representation, FIG. 6 shows a section view, along the line VI-VI from FIG. 5 , of the power-tool parting device according to the disclosure, in a schematic representation,
FIG. 7 shows a detail view of cutter carrying elements a cutting strand of the power-tool parting device according to the disclosure, in a schematic representation, FIG. 8 shows a further detail view of one of the cutter carrying elements of the cutting strand of the power-tool parting device according to the disclosure, in a schematic representation, and FIG. 9 shows a detail view of a disposition of the cutter carrying elements in a guide unit of the power-tool parting device according to the disclosure, in a schematic representation.
DETAILED DESCRIPTION
FIG. 1 shows a portable power tool 10 having a power-tool parting device 14 , which together constitute a power-tool system. The portable power tool 10 has a coupling device 12 for positive and/or non-positive coupling to the power-tool parting device 14 . The coupling device 12 in this case can be realized as a bayonet closure and/or as another coupling device considered appropriate by persons skilled in the art. The coupling device 12 is additionally provided to operatively connect the power-tool parting device 14 to the portable power tool 10 . The coupling device 12 is therefore provided, when in at least one operating state, to be coupled to the power-tool parting device 14 , which comprises at least one cutting strand 16 , and a guide unit 18 for guiding the cutting strand 16 . The portable power tool 10 has a power-tool housing 22 , which encloses a drive unit 30 and a transmission unit 34 of the portable power tool 10 . The drive unit 30 and the transmission unit 38 are operatively connected to each other for the purpose of generating a driving torque that can be transmitted to the power-tool parting device 14 , in a manner already known to persons skilled in the art. In this case, the drive unit 30 and/or the transmission unit 38 are provided, when in a mounted state, to be coupled to a cutting strand 16 by means of the coupling device 12 . The transmission unit 38 of the portable power tool 10 is realized as a bevel gear transmission. The drive unit 30 is realized as an electric motor unit. It is also conceivable, however, for the drive unit 30 and/or the transmission unit 38 to be of a different design, considered appropriate by persons skilled in the art. The drive unit 30 is provided to drive the cutting strand 16 of the power-tool parting device 14 , at least in one operating state, at a cutting speed of less than 6 m/s. The portable power tool 10 in this case has at least one operating mode in which it is possible for the cutting strand 16 to be driven in the guide unit 18 of the power-tool parting device 14 , along a cutting direction 40 of the cutting strand 16 , at a cutting speed of less than 6 m/s.
Furthermore, the portable power tool 10 has a stowage device 20 , which is provided to stow the power-tool parting device 14 when coupled to the coupling device 12 . The power-tool parting device 14 in this case is connected to the coupling device 12 in a positive and/or non-positive manner. The power-tool housing 22 of the portable power tool 10 , for the purpose of stowing the power-tool parting device 14 , when coupled to the coupling device 12 , has a side wall 24 , which faces toward the stowage device 20 ( FIGS. 3 and 4 ) and which, together with a tool covering element 26 of the stowage device 20 , delimit a receiving opening 28 of the stowage device 20 in which the power-tool parting device 14 can be stowed. The receiving opening 28 is provided to accommodate the power-tool parting device 14 when the power-tool parting device 14 is in a in-in state. The power-tool parting device 14 , when in a in-in state, is disposed with a partial region in the receiving opening 28 ( FIG. 2 ).
The power-tool parting device 14 in this case, when disposed in the receiving opening 28 , in a partial region, as viewed along a direction running at least substantially perpendicularly in relation to a cutting plane of the cutting strand 16 , is disposed between the side wall 24 of the power-tool housing 22 and the tool covering element 26 . The tool covering element 26 , as viewed in a plane perpendicular to the cutting plane of the power-tool parting device 14 coupled to the coupling device 12 , is formed on to the power-tool housing 22 in an L shape ( FIGS. 3 and 4 ). It is also conceivable, however, for the tool covering element 26 to be formed on to the power-tool housing 22 in another configuration, considered appropriate by persons skilled in the art. It is additionally conceivable for the tool covering element 26 to be realized by means of a component that is separate from the power-tool housing 22 , and that is connected to the power-tool housing 22 by means of a positive and/or non-positive connection. An outer wall 42 of the tool covering element 26 , which is disposed on a side of the tool covering element 26 that faces away from the power-tool housing 22 , at an end 44 of the power-tool housing 22 that faces away from the coupling device 12 , runs in the direction of the power-tool housing 22 , starting from the side of the tool covering element 26 that faces away from the power-tool housing 22 , and is connected to the power-tool housing 22 in a materially bonded manner. It is also conceivable, however, for the tool covering element 26 of the side of the tool covering element 26 that faces away from the power-tool housing 22 merely to run parallelwise in relation to the side wall 24 of the power-tool housing 22 that faces towards the tool covering element 26 .
For the purpose of stowing the power-tool parting device 14 , the coupling device 12 , when coupled to the power-tool parting device 14 , is mounted so as to be movable relative to the power-tool housing 22 ( FIG. 2 ). The coupling device 12 has a possibility for movement along a travel distance and/or about an axis that is independent of a pure closing movement of the coupling device 12 for the purpose of operatively connecting the power-tool parting device 14 to the portable power tool 10 , and/or of an opening movement of the coupling device 12 for the purpose of releasing the operative connection of the power-tool parting device 14 to the portable power tool 10 . The coupling device 12 in this case can be moved manually, as the result of application of force, by an operator, upon the coupling device 12 , into a position required by the operator and/or for the purpose of stowing the power-tool parting device 14 in the receiving opening 28 of the stowage device 20 . It is also conceivable, however, for the portable power tool 10 to comprise a coupling-device drive unit (not represented in greater detail here), which is provided to drive the coupling device 12 to execute a movement that is independent of the opening movement and/or the closing movement. The coupling-device drive unit can be realized, for example, as an electric motor unit, or as another coupling-device drive unit considered appropriate by persons skilled in the art.
The coupling device 12 is mounted such that it can be swiveled relative to the power-tool housing 22 . In this case, the coupling device 12 is mounted such that it can be swiveled about a swivel axis 36 running substantially perpendicularly in relation to a drive-unit longitudinal axis 46 of the drive unit 30 . The coupling device 12 can be moved by an operator into a required angular position of the coupling device 12 relative to the power-tool housing 22 . The angular position of the 12 relative to the power-tool housing 22 in this case lies in an angular range of 180°, by which the coupling device 12 can be swiveled about the swivel axis 36 . The portable power tool 10 comprises a locking unit 34 , which is provided to fix the coupling device 12 , when coupled to the power-tool parting device 14 , and when decoupled from the power-tool parting device 14 , in an angular position relative to the power-tool housing 22 . The locking unit 34 is provided to fix the coupling device 12 in the required angular position, relative to the power-tool housing 22 , by means of positive-fit elements (not represented in greater detail here) and/or non-positive-fit elements (not represented in greater detail here) of the locking unit 34 . For the purpose of actuating the positive-fit elements and/or non-positive-fit elements, the locking device 34 has an operating element 48 . The operating element 48 is realized as an operating lever. It is also conceivable, however, for the operating element 48 to be of a different design, considered appropriate by persons skilled in the art.
In addition, when the power-tool parting device 14 is coupled to the coupling device 12 , the swivel axis 36 runs substantially perpendicularly in relation to the cutting plane of the cutting strand 16 . The power-tool parting device 14 , therefore, when coupled to the coupling device 12 , can be swiveled by means of the coupling device 12 , about the swivel axis 36 that runs substantially perpendicularly in relation to the cutting plane of the cutting strand 16 , into the receiving opening 28 of the stowage device 20 ( FIG. 2 ). An operator actuates the operating element 48 of the locking unit 34 in order to undo a fixing of the coupling device 12 in an angular position relative to the power-tool housing 22 . The operator can then swivel the coupling device 12 about the swivel axis 36 , in order to swivel the power-tool parting device 14 into the receiving opening 28 of the stowage device 20 , for the purpose of stowage. For the purpose of maintaining a position of the power-tool parting device 14 in the receiving opening 28 , the operator actuates the operating element 48 of the locking unit again, in order the coupling device 12 in the angular position relative to the power-tool housing 22 , which angular position corresponds to a position of the power-tool parting device 14 when swiveled into the receiving opening 28 .
The portable power tool 10 additionally has an open-loop and/or closed-loop control unit 32 , which is provided to control the drive unit 30 by open-loop and/or closed-loop control in dependence on an angular position of the coupling device 12 relative to the power-tool housing 22 of the portable power tool 10 .
In this case, transmission of a driving torque from the drive unit 30 and/or the transmission unit 38 to the cutting strand 16 is interrupted, by means of the open-loop and/or closed-loop control unit 32 , as soon as the coupling device 12 is swiveled about the swivel axis 36 . The interruption of transmission of a driving torque in this case may be effected mechanically, electrically and/or electronically, the open-loop and/or closed-loop control unit 32 emitting a pulse to effect interruption. When the power-tool parting device 14 has been swiveled into the receiving opening 28 , the drive unit 30 is mechanically, electrically and/or electronically disconnected from an energy supply by means of the open-loop and/or closed-loop control unit 32 . The open-loop and/or closed-loop control unit 32 is additionally provided to alter a of the drive unit 30 in dependence on an angular position of the coupling device 12 , in the angular range of 180°, relative to the power-tool housing 22 . The open-loop and/or closed-loop control unit 32 in this case is provided to intervene in a motor control system, for controlling the drive unit 30 , in order to alter the drive direction.
For the purpose of driving the cutting strand 16 , or for the purpose of transmitting forces and/or torques from the drive unit 30 and/or the transmission unit 38 to the cutting strand 16 , the drive unit 30 has an armature shaft (not represented in greater detail here), which is connected in a rotationally fixed manner to a pinion gear 50 ( FIG. 4 ) of the drive unit 30 and/or of the transmission unit 38 . When in an operating state, the pinion gear 50 meshes with a toothed wheel 52 of the transmission unit 52 . The toothed wheel 52 in this case is realized as a ring gear. It is also conceivable, however, for the toothed wheel 52 to be of another design, considered appropriate by persons skilled in the art. The toothed wheel 52 is connected to an output shaft 54 of the transmission unit 38 in a rotationally fixed manner. On a side that, when in a mounted state, faces toward the cutting strand 16 , the output shaft 54 has a toothed end 56 , which is provided to be directly and/or indirectly coupled to the cutting strand 16 , for the purpose of driving the cutting strand 16 . The toothed end 56 is realized as a hexagon.
FIG. 5 shows the power-tool parting device 14 when decoupled from the coupling device 12 of the portable power tool 10 . The power-tool parting device 14 comprises the cutting strand 16 and the guide unit 18 , which together constitute a closed system. The guide unit 18 is realized as a guide bar. The guide unit 18 , as viewed in the cutting plane of the cutting strand 16 , additionally has two convex ends 58 , 60 . The convex ends 58 , 60 of the guide unit 18 are disposed at sides of the guide unit 18 that face away from each other. The cutting strand 16 is guided by means of the guide unit 18 . For this purpose, the guide unit 18 has at least one guide element 62 ( FIG. 9 ), by means of which the cutting strand 16 is guided. The guide element 62 in this case is realized as a guide groove 64 , which extends, in the cutting plane of the cutting strand 16 , along an entire circumference of the guide unit 18 . The cutting strand 16 in this case is guided by means of edge regions of the guide unit 18 that delimit the guide groove 64 . It is also conceivable, however, for the guide element 62 to be realized in another manner, considered appropriate by persons skilled in the art, such as, for example, as a rib-type element, formed on to the guide unit 18 , that engages in a recess on the cutting strand 16 . The cutting strand 16 , as viewed in a plane running perpendicularly in relation to the cutting plane, is surrounded on three sides by the edge regions that delimit the guide groove 64 ( FIG. 9 ). During operation, the cutting strand 16 is moved in a revolving manner along the circumference of the guide unit 18 , in the guide groove 64 , relative to the guide unit 18 .
The power-tool parting device 14 additionally has a torque transmission element 66 , for driving the cutting strand 16 , that is at least partially mounted by means of the guide unit 18 . The torque transmission element in this case has a coupling recess 68 that, in a mounted state, is coupled to the toothed end 56 of the output shaft 54 ( FIG. 4 ). It is also conceivable, however, for the torque transmission element 66 , when in a coupled state, to be directly coupled to the pinion gear 50 of the drive unit 30 and/or to the toothed wheel 52 of the transmission unit 38 , for the purpose of driving the cutting strand 16 . The coupling recess 68 is disposed concentrically in the torque transmission element 66 . The coupling recess 68 is realized as an internal hexagon. It is also conceivable, however, for the coupling recess 68 to be of another design, considered appropriate by persons skilled in the art.
When the torque transmission element 66 is not coupled to the toothed end 56 of the output shaft 54 , the torque transmission element 66 is disposed so as to be movable, transversely in relation to the cutting direction 40 of the cutting strand 16 and/or along the cutting direction 40 , in the guide unit 18 ( FIG. 6 ). The torque transmission element 66 in this case is disposed, at least partially, between two outer walls 70 , 72 of the guide unit 18 . The outer walls 70 , 72 run at least substantially parallelwise in relation to the cutting plane of the cutting strand 16 . In outer faces 74 , 76 of the outer walls 70 , 72 , the guide unit 18 has a respective recess 78 , 80 , in which the torque transmission element 66 is disposed, at least partially.
The torque transmission element 66 is disposed with a partial region in the recesses 78 , 80 of the outer walls 70 , 72 . The torque transmission element 66 in this case, at least in the partial region disposed in the recesses 78 , 80 , has an extent, along a rotation axis 82 of the torque transmission element 66 , that closes in a flush manner with one of the outer faces 74 , 76 and/or with both outer faces 74 , 76 of the guide unit 18 . In addition, the partial region of the torque transmission element 66 that is disposed in the recesses 78 , 80 of the outer faces 74 , 76 of the guide unit 18 has an outer dimension, extending at least substantially perpendicularly in relation to the rotation axis 82 of the torque transmission element 66 , that is at least 0.1 mm smaller than an inner dimension of the recesses 78 , 80 that extends at least substantially perpendicularly in relation to the rotation axis 82 of the torque transmission element 66 . The partial region of the torque transmission element 66 that is disposed in the recesses 78 , 80 is disposed, respectively, along a direction running perpendicularly in relation to the rotation axis 82 , at a distance from an edge of the outer walls 70 , 72 that delimits the respective recess 78 , 80 . The partial region of the torque transmission element 66 that is disposed in the recesses 78 , 80 therefore has a clearance within the recesses 78 , 80 .
FIG. 7 shows a detail view of cutter carrying elements 84 , 86 of the cutting strand 16 of the power-tool parting device 14 . The cutting strand 16 comprises a multiplicity of interconnected cutter carrying elements 84 , 86 , which are in each case connected to each other by means of a connecting element 88 , 90 of the cutting strand 16 that closes at least in a substantially flush manner with one of two outer faces 92 , 94 of one of the interconnected cutter carrying elements 84 , 86 (cf. also FIG. 9 ). The connecting elements 88 , 90 are realized in the form of pins. When the cutting strand 16 is disposed in the guide groove 64 , the outer faces 92 , 94 run at least substantially parallelwise in relation to the cutting plane of the cutting strand 16 . Persons skilled in the art will select an appropriate number of cutter carrying elements 84 , 86 for the cutting strand 16 according to the application. The cutter carrying elements 84 , 86 are each respectively integral with one of the connecting elements 88 , 90 . The cutter carrying elements 84 , 86 additionally have a respective connecting recess 96 , 98 , for receiving one of the connecting elements 88 , 90 of the interconnected cutter carrying elements 84 , 86 . The connecting elements 88 , 90 are guided by means of the guide unit 18 ( FIG. 9 ). In this case, when the cutting strand 16 is in a mounted state, the connecting elements 88 , 90 are disposed in the guide groove 64 . The connecting elements 88 , 90 , as viewed in a plane running perpendicularly in relation to the cutting plane, can be supported on two side walls 100 , 102 of the guide groove 64 . The side walls 100 , 102 delimit the guide groove 64 along a direction running perpendicularly in relation to the cutting plane. In addition, the side walls 100 , 102 of the guide groove 64 , as viewed in the cutting plane, starting from the guide unit 18 , extend outwardly, perpendicularly in relation to the cutting direction 40 of the cutting strand 16 .
The cutter carrying elements 84 , 86 of the cutting strand 16 have a respective drive recess 104 , 106 that, in a mounted state, is in each case disposed on a side 108 , 110 of the respective cutter carrying element 84 , 86 that faces toward the torque transmission element 66 . The torque transmission element 66 , in at least one operating state, engages in the drive recesses 104 , 106 , for the purpose of driving the cutting strand 16 . The torque transmission element 66 in this case is realized as a toothed wheel. The torque transmission element 66 therefore comprises teeth 112 , 114 , which are provided to engage in the drive recesses 104 , 106 of the cutter carrying elements 84 , 86 , in at least one operating state, for the purpose of driving the cutting strand 16 . In addition, the sides 108 , 110 of the cutter carrying elements 84 , 86 that face toward the torque transmission element 66 are realized in the form of an arc. The sides 108 , 110 of the cutter carrying elements 84 , 86 that face toward the torque transmission element 66 when in a mounted state are each realized in the form of an arc in partial regions 116 , 118 , 120 , 122 , as viewed between a central axis 124 of the respective connecting element 86 , 88 and a central axis 126 , 128 of the respective connecting recess 96 , 98 . The arc-shaped partial regions 116 , 118 , 120 , 122 are realized such that in each case they adjoin the drive recesses 104 , 106 , in which the torque transmission element 66 engages. In this case, the arc-shaped partial regions 116 , 118 , 120 , 122 have a radius corresponding to a radius of a course of the guide groove 64 at the convex ends 58 , 60 . The partial regions 116 , 118 , 120 , 122 are concave in form ( FIG. 8 ).
The cutting strand 16 additionally has cutting elements 130 , 132 . The cutting elements 130 , 132 are integral, respectively, with one of the cutter carrying elements 84 , 86 . The number of cutting elements 130 , 132 depends on the number of cutter carrying elements 84 , 86 . Persons skilled in the art will select a suitable number of cutting elements 130 , 132 according to the number of cutter carrying elements 84 , 86 . The cutting elements 130 , 132 are provided to effect parting-off and/or removal of material particles of a workpiece that is to be worked (not represented in greater detail here). The cutting elements 130 , 132 can be realized, for example, as full cutters, half cutters or as other kinds of cutters, considered appropriate by persons skilled in the art, which are provided to effect parting-off and/or removal of material particles of a workpiece that is to be worked. The cutting strand 16 is continuous. The cutting strand 16 is thus realized as a cutting chain. The cutter carrying elements 84 , 86 in this case are realized as chain links, which are connected to each other by means of the pin-type connecting elements 88 , 90 . It is also conceivable, however, for the cutting strand 16 , the cutter carrying elements 84 , 86 and/or the connecting elements 88 , 90 to be of another design, considered appropriate by persons skilled in the art. | The disclosure relates to a portable power tool comprising at least one coupling device which can be coupled to a power tool separation device comprising at least one cutting unit and at least one guide unit for guiding the cutting unit. The portable power tool comprises at least one storage device which is provided to stow the machine tool separation device at least when it is coupled to the coupling device. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 11/950,492, filed Dec. 5, 2007, issued as U.S. Pat. No. 7,912,058, which is a continuation of application Ser. No. 10/409,790, filed Apr. 9, 2003, issued as U.S. Pat. No. 7,327,731.
BACKGROUND
[0002] This disclosure relates to the field of communications supporting guaranteed data delivery on unreliable (i.e. best effort) networks. More specifically, the present invention relates to providing application independent, decoupled point-to-multipoint (PMP) connections for providing guaranteed data delivery service.
[0003] Multicasting is a network feature such that a packet from a single source can be delivered to multiple destinations. Typically, delivery is not guaranteed by the network although protocols exist to provide reliability.
[0004] Content distribution is an application level feature and greatly benefits with the availability of the network multicasting. However, multicasting by itself is not sufficient to meet the requirements of the content distribution in enterprise environment. Multicasting requires all destinations to be available and listening at the time of transmission. If a destination joins a multicast session late then it receives only partial data from the time it joined the session. In case of site failures or unavailability, the origin may be required to retransmit the data multiple times to deliver data to all sites. Furthermore, in the case of multicast content distribution, the data will be sent from the origin to the network at the speed of the lowest link among all destinations even if the origin and other sites may be connected to the network by high bandwidth links. Multicasting requires all destinations to join the multicast session at the time of data distribution. In most enterprise environments this requirement is difficult to meet due to several reasons. One main reason is that most of the enterprises that build their private networks are MNCs with large number of sites (few hundreds to few thousands) distributed across several countries. Thus, difference in time zones within U.S. and across other countries makes it difficult for all sites to join the multicast session at the same time. Other reasons are different work schedules or shifts, sites being unavailable or down, and/or other scheduling conflicts. In the case of multicasting, the data from the data centers can be sent only at the lowest speed amongst all destinations. In the WAN environment, typically, customers would like to be able to send or receive contents to or from the network at the speed of the link connecting the site to the network because data centers are usually connected to the network at higher speeds than remote locations.
[0005] In the WAN environment, an enterprise customer is most concerned about minimizing the delay by using caching, etc., and maximizing the utilization of the bandwidth. Clearly, to meet these requirements, several functionalities on top of multicasting are needed.
SUMMARY
[0006] A method, device and article are disclosed for transferring information in a network. The information transferred by connecting a destination device to a storage device operatively using the network. The storage device storing information to be transmitted to the destination device. The network defining a point-to-multipoint configuration between an origin device and a plurality of destination devices. The plurality of destination devices including the destination device. Also, the information received is stored in the storage device by the destination device in response to the destination device being connected to the network. The information received by the destination device having been transmitted from the origin device to the network prior to the destination device being operatively connected to the network.
[0007] Also, a system and method are disclosed herein in the form of application independent, decoupled, persistent, reliable, and extendible point-to-multipoint (PMP) connections with per destination scheduling, network spooling and playback, check-pointing and restart for providing guaranteed delivery of data from origin to multiple destinations such that the data is sent from the origin to the network only once at the speed of the link connecting the origin to a network and without waiting for the destinations to be connected to the network. The method further includes having the network store the data received from the origin in the same format and sequence as sent by the origin, creating point-to-multipoint connections with the destinations either upon request by the destination or upon request by the network based on a predetermined schedule, and sending the stored data from the network to each connected destination in the same format and sequence as sent by the origin. The method also allows the point-to-multipoint connection to be extended to new destinations any time before, during, or after the transmission of the data from the origin to the network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram illustrating bulk data delivery according to the embodiment of the present invention.
[0009] FIG. 2 is a flow chart of bulk data delivery operations according to the present invention.
DETAILED DESCRIPTION
[0010] For the purposes of the present disclosure, the following definitions will apply:
[0011] A “point-to-multipoint connection” (PMP) is a connection from an origin to multiple destinations.
[0012] A “decoupled” connection is a connection in which the origin does not connect with the destinations directly but uses network as a rendezvous point. In the “decoupled” PMP connection, the origin and destinations connect to the network independent of one another.
[0013] A “persistent” connection is a connection that continues to exist even when the origin or the destinations are no longer connected to it. The connection continues to exist until either explicitly requested to be removed or time-to-live parameter associated with it has expired.
[0014] A “reliable” PMP connection is a connection that guarantees the delivery of data from origin to the network and from the network to each destination in the same format and sequence as was sent by the origin to the network.
[0015] An “extendible” PMP connection is a connection that allows the reach of the PMP connection to be extended to new destinations (not specified at the time of creating the PMP connection) as long as the PMP connection exists in the network.
[0016] “Network spooling” is the capability of the network to store the packets sent by the origin to the network on the PMP connection. The packets are stored in the same format and sequence as sent by the origin.
[0017] “Playback” is the capability of the network to transmit the spooled data associated with the proposed PMP connection to any destination that connected “late”. A destination is “late” if it was not connected at the time when the origin started sending the packets to the network on the proposed PMP connection.
[0018] “Per destination scheduling” is the capability to set scheduling constraints for each destination. Network will then deliver data to each destination based on its scheduling constraint.
[0019] “Check-pointing and restart” is the network capability to maintain the state of the data transmission either from origin to the network or from network to each destination and in the event of failure resume transmission from the last check-pointed state.
[0020] Referring to FIGS. 1 and 2 , in accordance with the present invention, there is shown a PMP decoupled connection for reliable data delivery, specifically, bulk data delivery, from an application or a device 11 at source or origin 10 to an application or a device 11 at one or more destinations 12 over a network 14 via site connection manager (SCM) 16 and network connection manager (NCM) 17 . The flow of data is from origin to the destinations. The protocol used can be any application level transport protocols such as TCP/IP, UDP/IP etc. In the “decoupled” PMP connection, the origin and destinations connect to the network independent of one another. The application or a device 11 at each site interfaces with the SCM 16 to send or receive data and administer the PMP connections referred in this invention. The SCM 16 interacts with one of the closest NCMs 17 to send or receive data to or from the network and also administers the PMP connections inside the network.
[0021] The network 14 can preferably be a data network (e.g. a LAN, a WAN, the Internet), a wireless network (e.g. a cellular data network), some combination of these two types of communication mediums, or some other communication medium, such as for example, a satellite network.
[0022] The origin 10 or destinations 12 can preferably be computers such as PCs or workstations, running any one of a variety of operating systems or any device capable of running the SCM 16 and sending or receiving data using protocols (such as TCP/IP, UDP/IP etc.) supported by the SCM 16 .
[0023] The SCM 16 is software run at each site, i.e. the origin 10 and destination 12 . The SCM 16 as will be described in detail below provides APIs to allow applications to create PMP connections, connect to a PMP connection, add new destinations 12 to an existing PMP connection, send or receive data to or from the NCMs 17 on the PMP connections to which it is connected, send or receive data to or from the local application or device 11 . The SCM 16 interacts with the NCMs 17 to execute the APIs and perform other administrative operations such as recovery from connection failures. For the further ease of use, facility is provided in the NCMs 17 to maintain connection templates that in turn can be used to create PMP connections.
[0024] The NCM 17 is a software or a firmware running on one or more network switches or computer devices connected to network switches. The NCMs 17 implement the PMP connections in the network. The NCMs 17 allow SCMs 16 to connect with them and send commands to create/delete/modify a PMP connection, add destinations to an existing PMP connection, remove destinations from an existing PMP connection and receive status of one or more PMP connections. The NCMs 17 also perform scheduling functions for each PMP connection created in the network. Based on the scheduling constraints, the NCMs 17 initiate a PMP connection with the origin and destination SCMs 16 to send or receive data. If one or more SCMs 16 are not available, the NCMs 17 repeatedly retry to connect with unavailable SCMs 16 until the scheduling constraints dictate not to try any more. The origin and each destination SCM 16 connect only to one of the several NCMs 17 . In general, an SCM 16 will connect to the closest NCM 17 with spare loading capacity. The origin SCM 16 starts sending data to its NCM 17 as soon as the connection has been established. The origin SCM 16 does not wait for the destination SCMs 16 to be connected to the NCMs 17 . However, several destination SCMs 16 may already be connected before the origin starts sending the data. The destination SCMs 16 that connect after the origin has started sending data will be referred to as “late”. The NCM 17 connected to the origin SCM 16 internally forwards the incoming data to other NCMs 17 . Each NCM 17 spools the incoming data and also forwards it to the destination SCMs 16 that connected before the origin started sending the data. For each destination SCM 16 that connected “late”, the corresponding NCM 17 sends the data by playing back the spooled data. For each connection to an SCM 16 , the corresponding NCM 17 also performs check pointing. In the case failure, the data transmission restarts from the last check pointed state.
[0025] In general, data delivery or transmission according to the invention includes decoupled, persistent, reliable, and extendible point-to-multipoint (PMP) connections with per destination scheduling, network spooling and playback, and check-pointing and restart.
[0026] Referring back to FIGS. 1 and 2 , the first step in using the proposed PMP service is for the application at the origin 10 to create a PMP connection using the API provided by the SCM 16 . The SCM 16 at the origin 10 connects to an NCM 17 and sends it the request to create a PMP connection at step 20 . The request contains the IP addresses for the origin 10 and possibly for each specified destination 12 , application name at the origin 10 and each destination 12 , scheduling criterion for each destination 12 , parameters related to Time-To-Live, QOS, SLAB etc. At step 21 , the NCMs 17 create the requested PMP connection and start its scheduling.
[0027] Based on the specified scheduling, at step 22 , the NCMs 17 establish TCP/IP connections with the SCMs 16 at the destinations 12 . Based on the specified scheduling, at step 23 , the NCM 17 also establishes TCP/IP connection with the SCM 16 at the origin 10 . At step 24 , the NCMs 17 allow TCP/IP connections from any new (not specified at the time of creating the PMP connection) destination SCMs 16 . To make use of multicasting, UDP/IP is used. In the case of UDP/IP, there is no notion of a connection. The NCMs 17 and SCMs 16 first create and bind datagram (UDP) sockets. Once, the UDP socket has been created and bound, the NCMs 17 simply start sending the packets to the destination SCMs 16 using the UDP protocol. Since, UDP is not reliable, each NCM 17 waits for an acknowledgements from the corresponding SCMs 16 . Packets are retransmitted after a specified time out period.
[0028] Once, TCP/IP or UDP/IP sockets have been established between the NCM 17 and the SCM 16 at the origin, the SCM 16 then connects with the application using APIs provided by the SCM 16 . At step 25 , NCM 17 starts receiving the data from the application 11 via the SCM 16 at the origin 10 . Note that the SCM 16 at the origin 10 connects with the NCM 17 at the network 14 and starts sending data without waiting for the destinations 12 to connect to the NCMs 17 , thus establishing a decoupled connection. Similarly, as will be discussed below, the destinations can connect to the network and start receiving data any time either during or after the data transmission from the origin to the network. In the decoupled PMP connection, the origin and destinations connect to the network independent of one another. The advantage of decoupled connections is not only the efficiency because the data is sent from the origin to the network only once but also the ease of building applications. Furthermore, the decoupled connections allow the data to be sent at the local line rate rather than being limited by the slowest link amongst all destinations.
[0029] The invention is independent of the application or media type. For example, the data can be blocked or streaming and can come from an audio, video, database replication, disk mirroring or any other type of application. In the blocked data, the entire amount of data to be transferred is separated into a plurality of blocks, where each block includes a plurality of packets or frames. The block sizes may be same or variable. The size of the block can either be derived from the largest packet or be selected by a user. The streamed data refers to any data content that can be listened to (audio), viewed (video), or otherwise observed by a user without having to download the data content in its entirety. Streaming content is digitized content that has been compressed or encoded into a format that preferably an origin 10 can break down into packets and then stream across the network 14 to a destination 12 .
[0030] The data is sent from the application 11 at origin 10 to the network 14 only once via the SCM 16 at the origin 10 and NCM 17 at the network 14 . It is then the responsibility of the NCMs 17 at network 14 to deliver the data to the different destinations 12 . Data is sent from the origin 10 to network 14 at the speed of the link connecting the origin 10 to the network 14 rather than at the speed of the slowest destination 12 . Also at step 25 , as the data is received from the origin 10 , the receiving NCM 17 forwards the data to other NCMs 17 . In other words, the NCMs 17 spool the arriving data. At step 26 , the NCMs 17 verify if any existing connections with the SCMs 16 are “late” or “on-time”. A connection is “late” if it was established after the origin 10 started sending the data to the network 14 ; otherwise the connection is “on-time”. At step 27 , the NCMs 17 forward the incoming data from the origin to SCMs 16 that did not connect “late” i.e. were “on-time”. At step 28 , for each connection that was “late”, the NCM 17 sends the spooled data to the corresponding SCMs 16 . At step 29 , the NCM 17 checks to see if the origin has transmitted all the data. If “No” then the NCM 17 goes back to step 25 to receive more data. If “Yes” then at step 30 the NCM 17 disconnects from the SCM 16 at the origin 10 and sends the end-of-data signal to other NCMs 17 in the network 14 . However, all NCMs 17 continue to accept new connections from destinations until “time to live” parameter associated with the PMP connection has expired. At step 31 , a check is performed to determine whether the “time to live” parameter has expired. If no, then the NCM 17 goes back to step 26 to verify “late” connection. Otherwise, on the expiry of the “time to live” parameter, no new connections from the destinations are accepted and the PMP connection is closed at step 32 . The corresponding PMP connection is deleted once all the existing connected destinations have received the data. Also, note that the origin 10 does not wait for the data to be received by the destinations 12 , thus establishing a persistent connection. The PMP connection continues to exist in the network until either explicitly requested to be removed or time-to-live parameter associated with it has expired. The persistent PMP connection will allow the destinations to connect to the network and receive data even when the origin has finished sending data and is no longer connected to the network.
[0031] Furthermore, new destinations not specified at the time of creating the PMP connection, can be added any time during the existence of the connection to dynamically extend the reach of a PMP connection. Thus this extendable PMP connection adds and connects new destinations 12 as long as the PMP connection exists in the network 14 . Also, the data to be delivered from the origin 10 to the destination 12 is reliable. In other words, data transmitted from the origin 10 to the network 14 is delivered from the network 14 to each destination 12 in the same order as it was originally sent by the origin 10 .
[0032] The data arriving from the origin 10 to the network 14 is forwarded to each destination 12 connected to the network 14 . Besides data forwarding, network 14 plays other important roles such as spooling, playback, per destination scheduling, check-pointing and restart, as described in detail below.
[0033] Spooling is the capability of the network 14 to store packets containing data sent by the origin 10 . All the data transmitted from the origin 10 is stored at step 25 in the network. The packets containing data are stored in the same format and sequence as sent by the origin 10 . The data packets spooled in the network 10 generally service “late” connection requests by the destinations 12 . A destination 12 is “late” if it was not connected at the time when the origin 10 started sending the packets to the network 14 on the proposed PMP connection. Otherwise, the destination 12 is “on-time”. By playback, the network can transmit the spooled data associated with the proposed PMP connection to any destination that connected late.
[0034] Additionally, network 14 also sets schedule constraints for the origin 10 and each destination 12 . The data will then be received by the network 14 from the origin 10 based on the origin's scheduling constraint. The data will then be delivered by the network 14 to each destination 12 based on its scheduling constraint. The data flowing from each connection, i.e. from origin 10 to network 14 or network 14 to destination 12 is check-pointed by the network 14 at fixed intervals. In the event of a transmission failure, transmission will resume from the last check-pointed state.
[0035] Preferably, there are two modes of operations supported at the destinations 12 . One is Destination Initiated (Pull) and the other is Network Initiated (Push). In the case of “Destination Initiated”, the application at the destination 12 requests using the API provided by its local SCM 16 to connect to a PMP connection. If the requested PMP connection exists in the network 14 , i.e. already has been created by the origin 10 , then the SCM 16 at the destination site 12 establishes a socket based TCP/IP connection with the network 14 and returns the connection handle to the application. Once the connection with network 14 has been established, the application at the destination 12 can start receiving data if available on the connection otherwise it is blocked waiting for the data to arrive.
[0036] In the case of “network initiated”, at the time of creating a PMP connection and based on the specified scheduling, the network 14 tries to establish a connection with each destination 12 not already connected. To do this, the appropriate NCM 17 requests the SCM 16 at each destination 12 not already connected to invoke the appropriate application and establish the connection. The application invoked is the one specified by the administrator of the origin 10 at the time of creating the connection in the network. Once the connection with network has been established, the application at the destination 12 can start receiving data if available on the connection otherwise it is blocked waiting for the data to arrive.
[0037] While the invention has been described in relation to the preferred embodiments with several examples, it will be understood by those skilled in the art that various changes may be made without deviating from the spirit and scope of the invention as defined in the appended claims. | A method, device and non-transitory computer-readable storage medium transferring information using a network. The information transferred by connecting a destination device operatively to a storage device using the network. The storage device storing information to be transmitted to the destination device. The network providing a point-to-multipoint connection between an origin device and a plurality of destination devices. The plurality of destination devices including the destination device. Also, the information being transferred by receiving the information stored in the storage device by the destination device in response to the destination device being operatively connected to the storage device. The information received by the destination device having been transmitted from the origin device to the network prior to the destination device being operatively connected to the storage device. | 7 |
BACKGROUND OF INVENTION
This invention relates to methods for preparing synthetic composition board. More particularly, this invention relates to a process for preparing wood composition board which involves applying a pigmented coating to the surface of a fibrous mat prior to subjecting the mat to a press treatment.
Several methods have been suggested for preparing synthetic fiberboards or hardboards which are based upon wood particle chips or other lignocellulose fibers. These products are generally prepared by forming a mat of the wood precursor and consolidating the mat into a board by the application of heat and pressure. One major problem in forming these products into a unitary mat has involved release of the densified wood composite from the hot press plates. Another major problem exists with wood composition products, in that extractives, such as wood tannin or sugars and synthetic waxes tend to migrate to the surface and form tacky spots on the exterior of the finished composition board. The tacky spots collect dirt and cause unsightly spotting.
U.S. Pat. No. 4,237,087 discloses a water-borne, base coat composition which facilitates the embossing of wood-based particle board. The coating composition contains an acrylic emulsion resin, a urea resin, and an acid catalyst. However, no disclosure is made of the use of platelet form talc.
U.S. Pat. No. 4,201,802 also discloses a composition for the surface sealing of hard board products. However, the coating composition employed in this patent is a polymer of polyvinyl alcohol employed in combination with a volatile amine, emulsified fatty acids or esters, and aluminum stearate. While the patent does disclose the use of talc as a general purpose inert pigment, it does not disclose the particular type of talc employed nor the benefits derived from its use.
Platey talc is a known pigment which is most often used in forming undercoatings for metals because it tends to improve sanding properties and water resistance. However, its use in pigmented prepress coatings has not been disclosed previously.
Accordingly, it is an object of this invention to prepare in-press pigmented coatings for composition board, which coatings exhibit a smooth, embossed or textured surface.
It is another object of this invention to prepare pigmented coatings which exhibit excellent press release properties.
It is still another object of this invention to prepare sealers which limit or eliminate the surface migration of wood tannin, sugars or low melting waxes with attendant discoloration, dirt attraction and spotting.
These and other objectives are obtained by employing the process of the instant invention.
SUMMARY OF INVENTION
Basically, the instant invention involves a conventional process for preparing composition board products which employs a unique step of applying to a composition mat of a density of less than 60 lbs per cubic foot prior to the application of heat and pressure, a coating composition comprising an hydroxyl or carboxylic acid-containing acrylic vehicle, a high-melting wax, a melamine-based crosslinker for the vehicle, and a platelet form of talc.
By applying this emulsion to the surface of the fibrous mat prior to the application of heat and pressure, it is possible to obtain a finished composition board product which does not upon exterior exposure exhibit surface spotting caused by wood tannin, sugars or wax migration. In addition, the coating compositions of the instant invention exhibit excellent press release properties which aid in the continuous removal of the composition board product from the mold after the repeated application of heat and pressure. In addition, the coating compositions of this invention do not carbonize even under the high surface pressures and temperatures employed in preparing composition board.
DETAILED DESCRIPTION OF INVENTION
The basic process for the preparation of composition board from wood-based products is well known and will only be discussed in a very summary fashion here. Generally, this process is disclosed in U.S. Pat. Nos. 3,098,785 and 4,238,438, which are incorporated herein by reference. As used herein, the phrase "composition board" includes the various hardboards, fiber boards, particle boards, wafer boards and strand boards, including, but not limited to, wet processed hardboards, dry processed hardboards, wet/dry processed hardboards, medium density fiber board, oriented strand board, and mende boards, to name but a few.
The general process involves using wood chips or particles which are steamed, converted to fibers, formed into a mat, and hot pressed to form a hard board or fiber board. Usually the wood particles are fed into a cooker and held under pressure of up to about 200 psi for less than about 10 minutes at temperatures ranging up to somewhat less than about 400° F. The steamed chips are then refined into fibers which are introduced into a felting zone, where a thermosetting glue and other additives, such as hydrophobic, low-melting waxes, are mixed with the fiber products. In most cases, the glue is a phenolformaldehyde resin which is added in the range of about 0.5 to about 10 percent, based on the weight of the dry fiber. The low-melting waxes are added at levels up to about 13%, based on the dry fiber.
After the glue has been mixed with fibers, the treated wet or dry mat is conveyed into a hot press where one or more than one high pressure, heat treatment is applied. In a typical operation, the mat is pressed for about 10 seconds at 400 psi, then for about 4 minutes at 150 psi and 450° F. In general, one or more than one high pressure treatment step may be employed with pressures ranging up to about 1200 psi and temperatures ranging from about 200 to about 600° F.
As recognized in the prior art, one of the major problems in preparing composition board products has resided in the high pressure, high temperature, time duration, press step. Another prior art problem was the so-called "press release" characteristics of the composition board. For example, in many of the prior art processes, fiberboard or hardboard tended to stick to the surface of press plates after pressing. Another problem with prior art products was the lack of density or surface hardness of the hard board. These deficiencies caused paint hold-out problems and poor exterior durability of the product. For example, in coating many prior art hardboards, the coating composition would be extensively absorbed into the hardboard itself, and as a result, large amounts of expensive coating compositions were required. In addition, the exterior exposure properties of untreated fiber board products were often unsatisfactory. Finally, certain prior art processes tended to contribute to carbonization buildup on the press plates, and in many cases after only several days' pressing, it was necessary to stop the processing operation and clean the plates.
As pointed out above, one of the major problems in prior art manufacture of composition board products was wood tannin, sugar, and wax bleed discoloration. In forming pressed board compositions, it is necessary to employ various low grade waxes, such as petroleum slack wax, in order to impart the desired degree of hydrophobic properties to the finished product. After preparation, however, these waxes often tend to leach to the surface and actually exude through any coating composition onto the finished surface. Because of the low melting point of these waxes, the migration causes the coated surface of the hardboard to become tacky in areas where the wax has migrated through to the surface. These tacky areas, in turn, pick up dirt from the atmosphere and cause a "spotting" of the hardboard surface. In a similar fashion, tannins and sugars often migrate to the surface of coated composition board products, causing objectionable surface discolorations.
In the instant invention the coating composition described hereafter reduces or eliminates surface spotting caused by wax, tannin or sugar migration. In addition, the coatings described hereafter possess excellent press release properties, exit from the press with uniform color, and greatly improve the paint hold-out characteristics of the finished composition board products.
The acrylic emulsion resin useful herein can be prepared by conventional emulsion process techniques, which involve the emulsion polymerization of various acrylic and other alpha beta ethylenically unsaturated monomers in the presence of free radical generating catalysts and various surfactants or emulsification agents. These processes and products are well known in the art and will not be described further. However, the preferred acrylic emulsions which are useful herein contain at least about 20 percent by weight of an alpha beta ethylenically unsaturated monomer based upon acrylic or methacrylic acid. Such monomers include predominantly the C 1 -C 8 esters of these acids. In order to insure that the acrylic emulsions are subject to crosslinking using the crosslinking agents described hereafter, they should contain from about 1.0 to about 30 percent by weight of a carboxyl or hydroxyl functional monomer. Examples of the acid monomers include acrylic, methacrylic, ethacrylic, crotonic and itaconic acids, as well as various half acid esters or maleic and fumaric acids. The hydroxy monomers include the hydroxyalkyl acrylates and methacrylates predominantly. Also included are other acrylate-type monomers, including acrylonitrile and methacrylonitrile and other related materials. In order to increase the T g of the polymers prepared according to the instant invention, up to about 40 percent by weight of an alpha beta ethylenically unsaturated aromatic monomer copolymerizable with the aforementioned acrylate and methacrylate esters can be employed. Examples of such materials include styrene and vinyl toluene. Also included are up to about 60 percent by weight of another optional monomer copolymerizable with these first monomers.
The acrylic emulsion useful herein should have a viscosity of less than 2000 cps, preferably less than 1000 cps, at a solids content of about 40 to about 60 percent by weight. The preferred emulsions useful herein are the nonionic surfactant stabilized emulsions based upon, for example, the various polyethylene oxide and polypropylene oxide-based phenolic-type surfactants. However, the anionic and cationic surfactant stabilized emulsions may also be employed herein.
The second crucial element of the compositions of the instant invention is a melamine formaldehyde type crosslinking agent for the acrylic emulsion. The curing agent should be water-soluble or readily water-dispersible, with or without the use of a co-solvent, and is preferably a melamine-based crosslinking agent, although urea/formaldehyde-type curing agents may also be employed alone, or in combination with the melamine formaldehyde-type curing agents described hereafter. Basically, the crosslinking agents are preferably based upon polyalkoxymethylol melamine, with the hexamethoxymethylol melamines being most preferred.
The third crucial component of the compositions of the instant invention is a high-melting wax. Generally these waxes must have a softening point in the range of above about 140° F., preferably 150° F. Most preferred among these waxes are waxes of the carnauba, polyethylene polymekan, micro crystalline, and other similar types.
The final component of the compositions of the instant invention is a platelet, platey or micaceous form of talc. (Talc also occurs in these other forms: 1. fibrous or foliated; 2. acicular or tremolitic; and 3. nodular or steatite.) Generally, talc materials are of two types, either hydrous or anhydrous. Both are based upon magnesium silicate and may have the chemical formula Mg 3 Si 4 O 10 (OH) 2 or 3MgO.4SiO 2 .H 2 O. While either material may be used, the hydrated materials are most preferred. In either event, it is crucial that the talc compositions of the instant invention be of the platelet form. In other words, the material must form platelets which are wider and broader than they are thick. In general, it is preferred that the talc compositions of the instant invention have aspect ratios (average diameter/average thickness) of about 10:1 to 30:1, preferably about 15:1 to 25:1, and that they have diameters of about 1-4 micrometers and thicknesses of about 0.5 to about 0.05 micrometers., preferably diameters of about 2 micrometers and thicknesses of about 0.1 micrometers.
The compositions of the instant invention may also be compounded with pigments, fillers, reinforcing agents, thickeners, flow control agents, release agents and other conventional coating formulation agents. In addition, the compositions of the instant invention may contain certain acidic or basic materials to adjust the pH to the range of above about 7, preferably from about 8 to 10. Lower pH materials are less stable and often will gel prior to use. Preferably the compositions herein should be compounded employing pigment volume concentrations in the range of about 10 to about 60%.
The compositions of the instant invention should be added in the following weight ratios, the total being 100:
______________________________________ Preferred Most Preferred______________________________________Acrylic resins 2.5-58% (solids) about 16%Melamine resins 0.3-17% (solids) about 1.7%Wax 0.2-12% (solids) about 2.5%Platelet talc 25-97% (solids) about 80%______________________________________
EXAMPLE 1
An exterior, in-press primer was prepared by blending with mild agitation 119.95 parts of tap water, 35.02 parts of 3.3 percent aqueous hydroxyethyl cellulose, 7.47 parts of SMA 1440H dispersant, a styrenated dispersant available from Arco Chemical Company, 1.78 pounds of Tryton CF10, a nonionic polyethylene oxide-based surfactant, available from Rohm & Haas Company, 1.52 pounds of Hipower EK-18, an anionic dioctyl sulfosucsinate wetting agent available from High Point Chemical Co., 1.65 pounds of Nopco NXZ, a defoamer available from Diamond Shamrock Corp., and 21.2 pounds of Cymel 303, a hexamethoxymethyl melamine, available from the American Cyanamid Company.
Following blending under Cowles agitation, the following were sifted slowly into the above mixture: 155 pounds of a titanium dioxide pigment, available from the DuPont Corporation under the trade name of Typure R931, 55 pounds of a titanium dioxide available from the Benelite Corp. under the trade name of Hytox, 40 pounds of a talc compound as described hereafter, and 110.0 parts of Imsil A-10, a silica compound available from the Illinois Mineral Corporation. The platelet talc described above was manufactured by the Pfizer Corporation under the trade name of Microtalc MP12-50. It exhibited a maximum top particle size of 12 microns, an oil absorption percentage of 50, a specific gravity of 2.70, a Hegman finess of 6.0, and had the following chemical analysis:
______________________________________SiO.sub.2 61.5%MgO 30.0%CaO 0.1%Al.sub.2 O.sub.3 2.2%Fe.sub.2 O.sub.3 0.7%Acids solubles 0.5%Loss on ignition 5.3%Water solubles 1.0%______________________________________
The resulting blend was dispersed to a grind fineness of 6NS and 158.27 parts of water, 387.20 parts of a 46.5% solids, styrene/methylmethacrylate, hydroxyl-containing polymeric emulsion, having a trade designation of Rhoplex 1822 and available from the Rohm & Haas Company, 8.69 parts of a 25% solids carnauba wax emulsion, available from Michelman Chemical Co., 0.93 parts of a Proxcel CRL fungicide, available from ICI America, Inc., were added, followed by 2.80 parts of tap water and 0.85 parts of dimethylamino ethanol. The pH of the resulting coating was 8.5-9.0, and the coating had a viscosity of 15-20 seconds on a #2 Zahn cup, a weight per gallon of 11.08 parts, and a weight solids content of 51.6 percent. The coating produced an excellent prepress finish, which eliminated the wax migration spotting after applying to Masonite boards prior to final finish.
EXAMPLES 2-4
Results similar to those of Example 1 were obtained when the Cymel 303 of Example 1 was replaced on a weight basis with (2) Cymel 373, a partially methylated methylol melamine resin available from the American Cyanamid Company, with (3) Uformite MM-83, a partially methylated methylol melamine available from the Reichold Chemical Co., and with (4) Cymel 1171, a glycoluril formaldehyde, hetrocyclic crosslinking agent available from the American Cyanamid Company.
EXAMPLES 5-7
Similar results were obtained when the Rhoplex 1822 was replaced on a weight basis with hydroxy functional acrylic latex resins available from the Union Carbide Corporation, having trade names of (5) UCAR Vehicle 4550 and (6) UCAR 4358 and with (7) Rhoplex TR 407, an internally crosslinking, acrylic emulsion available from the Rohm and Haas Company.
EXAMPLE 8
22.5 gallons of water were blended under mild agitation in a Cowles mixer with 1.90 pounds of SMA 1440, 7.5 gallons of hydroxyethyl cellulose, 0.27 gallons of Nopco NXZ, and 1.70 gallons of Cymel 303, all as described above in Example 1. After this blend was prepared, 85 pounds of platey talc and 375 pounds of Imsil A-10, were sifted slowly into the blend, and the resulting mixture was dispersed to 6 NS. Added to this mixture were 11.43 gallons of water and 34.33 gallons of the Rhoplex acrylic emulsion, followed by 0.83 gallons of carnauba wax dispersion and 0.1 gallon of Proxel CRL. After mixing, the resulting emulsion was adjusted to a pH of 8.5-9.0 using a mixture of 0.25 gallons of water and 0.25 gallons of dimethylethanol amine. The resulting coating composition had a #2 Zahn cup viscosity of 15 sec and a solids content of 54.8 percent. When applied to Masonite hardboard, excellent press release properties were obtained. | Disclosed herein is a process for coating a fiber mat with a pigmented coating prior to subjecting the mat to heat and pressure treatment to form a composition board having a smooth, embossed or textured surface. The coating contains a mixture of an acrylic, hydroxyl or carboxyl functional vehicle, a melamine-based coating crosslinking agent for the vehicle, a high-melting wax, and a platelet form of talc. By employing this process, composition board products are obtained which have superior surfaces and surface finishes. In addition, these finishes inhibit composition board extractive migration which causes the formation of discolored spots on the finished composition board's surface. | 1 |
RELATED APPLICATIONS
This application is based on International Application No. PCT/US 2011/032406, filed Apr. 14, 2011 and claims the benefit of U.S. provisional application 61/327,945, filed Apr. 26, 2010.
FIELD OF THE INVENTION
The present invention relates to an appliance latch and in particular to a latch assembly retaining door closure in the event of a fire in the dryer.
BACKGROUND OF THE INVENTION
Clothes dryers may employ a rotating perforated drum into which clothes are placed and tumbled within circulation of heated air to dry the clothes. The drum may be accessible for loading and removing clothing through an opening in the front of the dryer cabinet that may be covered by a hinged door when the dryer is in use. Typically, the door is held closed by a spring latch that retains the door closed against the light force of tumbling clothing but that may be readily opened at any time by a higher force applied to the dryer door handle by the user.
In some situations, it may be desirable to provide a latch that will maintain the door in the closed position under elevated temperatures that may melt plastic components. In this way, in the event of a fire in the interior of the dryer, the door will remain closed confining the fire to the interior.
One such latch is described in US patent application 2009/0260198, assigned to the assignee of the present invention and hereby incorporated by reference, which discloses a strike having a bulbous tip that may be received between plastic jaws of a spring clip. The plastic jaws are biased by a metallic U-shaped spring having arms that open by deflecting or pivoting about an axis generally perpendicular to the motion of the strike. The arms of a metallic spring pass through the plastic jaws so that should the plastic jaws melt, the ends of the arms are nevertheless close enough to the strike to grip and retain the strike when the plastic jaws are gone. The plastic jaws, during normal operation, reduce the friction of engagement and disengagement of the latch with the strike.
A U-shaped spring holding the plastic jaws is attached at its base to a metal U-shaped bracket surrounding the U-shaped spring having legs extending forward to attach to the housing of the dryer behind an opening through which the strike would make pass. This metal U-shaped bracket holds the U-shaped spring in proper position even in the event of a fire.
SUMMARY OF THE INVENTION
The present invention provides a latch for a clothes dryers or the like in which the U-shaped spring of the prior art is rotated by 90 degrees so that the arms of the U-shaped spring clip pivot about axes generally parallel to the motion of the strike and the arms of the U-shaped spring clip extend across the strike and the opening. This configuration permits elimination of the U-shaped bracket permitting instead a simple plastic support because the U-shaped spring clip has an orientation that may retain itself on the strike and block retraction of the strike even in the absence of the support bracket. This orientation further permits greater flexibility in controlling the spring clip force constant in a shallow form factor. Finally, this orientation permits locking of the strike to be simply accomplished by collaring the ends of the U-shaped spring clip, these ends being displaced from and thus free from interference with the strike itself.
Specifically the present invention provides a latch strike retention assembly adapted to accept and retain a latch strike and including a substantially “U” shaped spring having opposing and substantially parallel arm portions extending from a common base portion. A support bracket holds the U-shaped spring behind an opening through which the strike must pass so that the arm portions of the U-shaped spring extend generally perpendicular to a direction of strike engagement with the arm portions, and the arm portions may flexibly separate within a plane perpendicular to the direction of latch engagement to receive and restrain the strike therebetween.
It is thus a feature of at least one embodiment of the invention to provide a latch with a shallow form factor. It is a further feature of this embodiment to permit use of a simple support bracket which may be in its simplest form a thin plate which does not require high-strength materials for proper support of the U-shaped spring.
The support bracket may be a thermoplastic material.
It is thus a feature of at least one embodiment of the invention to provide a design permitting a readily manufacturable injection molded support bracket while still ensuring that the door will remain latched at elevated temperatures that might melt or burn plastic. By sizing the U-shaped spring to be larger than the aperture and orienting the U-shaped spring across the aperture, retention of the strike may be maintained even without the support bracket.
The support bracket may include apertures receiving arm portions of the U-shaped spring when the arm portions are inserted into the apertures along the plane and may include a snap element capturing the based portion of the U-shaped spring against extraction from the apertures along the plane after insertion of the arm portions into the apertures past the snap element.
It is thus a feature of at least one embodiment of the invention to retain the elements of the latch together for easy manufacture while permitting necessary motion of the U-shaped spring.
The U-shaped spring is a single rod of substantially circular cross-section.
It is thus a feature of at least one embodiment of the invention to provide an extremely simple wire-form latch element whose orientation permits the necessary flexibility to be obtained in an arbitrary wire size. It is another feature of at least one embodiment of the invention to provide an outer surface of the U-shaped spring conducive to smooth engagement with a tapered strike.
The arm portions of the U-shaped spring distal to a point of engagement with the strike may have an un-flexed separation smaller than a corresponding thickness of the strike between the arm portions when the strike is engaged with the U-shaped spring, and/or the arm portions of the U-shaped spring at a point of engagement with the strike may have an un-flexed separation smaller than a corresponding thickness of the strike at the point of engagement.
It is thus a feature of at least one embodiment of the invention to ensure that the U-shaped spring is retained on the strike even in the absence of the support plate.
The U-shaped spring may extend at least three times the width of the base portion measured perpendicularly to the extent of the arm portions.
It is thus a feature of at least one embodiment of the invention to provide a substantially parallel separation of the arm portions of the U-shaped spring for robust engagement with the strike. It is another feature of at least one embodiment of the invention to permit engagement of the strike at a variety of positions along the U-shaped spring to accommodate vertical strike movement resulting from manufacturing tolerances and/or door hinge sag.
The latch strike may further include a collar movable relative to the U-shaped spring between: (a) a first locked position at least partially surrounding the arm portions of the U-shaped spring preventing separation of the arm portions to release the strike after the strike has passed through the U-shaped spring, and (b) a second unlocked position removed from the arm portions of the U-shaped spring permitting separation of the arm portions to release the strike after the strike has passed through the U-shaped spring.
It is thus a feature of at least one embodiment of the invention to provide a latch permitting simple addition of a locking function.
The U-shaped spring may be held substantially fixed with respect to the support bracket and the collar is movable with respect to the support bracket.
It is thus a feature of at least one embodiment of the invention to permit a locking during engagement of the latch and strike such as may impart a high frictional resistance to movement of the U-shaped spring.
The latch strike retention assembly may further include an electrically powered actuator moving the collar with respect to the support bracket between the locked and unlocked position in response to an electrical signal.
It is thus a feature of at least one embodiment of the invention to permit automatic locking of the door at certain appliance operating stages.
The actuator may be at least one electrical solenoid and/or may include a thermal actuator preventing movement of the collar from the locked to the unlocked position when power is disconnected from the electrical solenoid for a predetermined period of time corresponding to a thermal cooling.
It is thus a feature of at least one embodiment of the invention to permit rapid locking action as may be necessary for certain safety features while ensuring residual locking even under power loss conditions that nevertheless ultimately permit access through an unlocked door.
The latch strike retention may further include a strike sensor communicating with a first contact set to provide a signal dependent on engagement of the strike with the U-shaped spring.
It is thus a feature of at least one embodiment of the invention to permit determination of proper door position for locking.
The collar may further communicate with the first contacts to provide a signal dependent on engagement of the collar with the arm portions of the U-shaped spring.
It is thus a feature of at least one embodiment of the invention to permit a single signal to be used for effective lock control. By providing a signal only when the strike is in position and the collar properly placed, door closure can be detected by momentary operation of the electronic actuator and monitoring of the contacts, and complete locking may be confirmed by closure of the contacts.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical clothes dryer such as may employ the present invention showing locations of the strike and latch mechanism, the latter behind a front panel of the dryer;
FIG. 2 is an exploded fragmentary diagram of the latch mechanism positioned behind an opening in the front panel of the dryer, the latch mechanism including a plastic retainer element and U-shaped spring clip such as may receive a bulbous tip of a strike;
FIGS. 3 a - c are front elevational, fragmentary side elevational and fragmentary top plan views of the strike engaged with the latch mechanism of FIG. 2 showing blocking of the strike from retraction through the opening in the cabinet even without the plastic retainer element;
FIG. 4 is an orthogonal view of the rear of the latching mechanism of FIG. 2 as assembled showing the retention of the U-shaped spring clip beneath bridges formed in the plastic retainer element as retained by a snap ramp;
FIGS. 5 and 6 are top plan views of the ends of the U-shaped spring clip in an embodiment where the ends may be moved out of a normal plane of the U-shaped spring clip within walls of a collar to prevent them from separating such as would permit release of the strike to provide a locking action;
FIGS. 7 a and 7 b are front elevational views of the U-shaped spring clip in an embodiment in which the spring clip is moved along the plane by an electric actuator to place the ends in between the walls of a collar to provide a locking;
FIGS. 8 a and 8 b are figures similar to those of FIGS. 7 a and 7 b showing a movable collar for providing a locking action.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 , an appliance 10 , such as the dryer, may provide for a housing 12 generally constructed of enameled steel or the like. The housing 12 may have a front panel 14 providing a drum access opening 16 leading to the dryer drum for the insertion and removal of clothes therethrough. The drum access opening 16 may be covered during use of the appliance 10 by a hinged door 18 having a door strike 20 attached to an outer edge of the rear of the door 18 to extend rearward therefrom. The door strike 20 may be received through a latch opening 22 in the front panel 14 to be retained by a latch mechanism (not shown in FIG. 1 ) as will be described.
Referring now to FIG. 2 , the strike 20 may extend generally along an axis 24 that also describes the local motion of the strike 20 as the door 18 is closed. The leading edge of the strike 20 as the door 18 is closed, and as is positioned toward the latch opening 22 , provides a bulbous end 26 that permits its retention by the strike retention mechanism 28 behind the latch opening 22 .
The strike retention mechanism 28 may include a U-shaped spring 32 and a support bracket 30 constructed of injection-molded thermoplastic. The U-shaped spring 32 provides two upwardly extending arms 36 formed by bending a round cross-section of steel wire in a U-shape until the arms 36 are substantially parallel as extending away from a base 39 . During use, as will be described, arms 36 may flex to pivot apart about an approximate pivot axis 38 parallel to but displaced from the axis 24 and in a plane 31 generally perpendicular to the axis 24 to admit the bulbous end 26 of the strike 20 .
The U-shaped spring 32 is retained in proper position to receive the strike 20 as corralled by the support bracket 30 which includes an escutcheon panel 40 abutting a rear surface of the front panel 14 . The escutcheon panel 40 includes an escutcheon aperture 42 allowing the strike 20 to pass through the escutcheon panel 40 to be received between the arms 36 of the U-shaped spring 32 . The escutcheon aperture 42 is surrounded by a collar 44 which has an outer periphery fitting snugly into the latch opening 22 of the front panel 14 and a beveled interior periphery helping to funnel the strike 20 into alignment with the escutcheon aperture 42 . The escutcheon panel 40 may be held against the front panel 14 by means of one or more screws 46 (only one shown for clarity) received by corresponding bores 48 in the escutcheon panel 40 .
Referring now to FIG. 4 , the base 39 of the U-shaped spring 32 may fit around a boss 50 extending rearwardly from a rear surface of the escutcheon panel 40 about bores 48 beneath the escutcheon aperture 42 . The arms 36 of the U-shaped spring 32 may then extend upward toward a second boss 52 extending rearwardly from a rear surface of the escutcheon panel 40 about a second bore 48 above the escutcheon aperture 42 . The bosses 50 and 52 provide a surface for thread engagement by the screws 46 (shown in FIG. 2 ). The arms 36 may be retained by molded bridge elements 54 on the rear surface of the escutcheon panel 40 having internal apertures 56 through which the arms 36 may pass while still providing for their ability to flex outward to receive the strike 20 through the escutcheon aperture 42 . The U-shaped spring 32 may be retained against removal from the apertures 56 by a snap element 51 . The snap element 51 provides a ramp surface assisting in sliding the U-shaped spring 32 into the apertures 35 along the plane, but a blocking surface preventing the reverse motion.
Referring now to FIGS. 3 a - c , the strike 20 may engage the U-shaped spring 32 after the bulbous end 26 of the strike 20 passes through an engagement plane 31 in which the arms 36 of the U-shaped spring 32 lie. The arms 36 of the U-shaped spring 32 will generally be parallel to each other for a height 60 suitable to accommodate different elevational positions of the strike 20 as may result from a sagging of the door 18 over time. The distal ends 62 of the arms 36 removed from the base 39 of the U-shaped spring 32 may be bent inward toward each other to have a reduced separation 66 when the parallel portions of the arms 36 of the U-shaped spring 32 are relaxed less than the horizontal width of the strike 20 between the arms 36 . More generally, the relaxed separation of the arms 36 may be less than the horizontal width of the strike 20 between the arms 36 . In these ways, even in the absence of the support bracket 30 , for example when melted or deformed, the U-shaped spring 32 will retain its grip on the strike 20 and be in a position to prevent withdrawal of the strike 20 through the latch opening 22 without application of force sufficient to spread the arms 36 apart as would be required during normal latching operation.
Referring momentarily also to FIG. 2 , the bulbous end 26 of the strike 20 may have its leading apex 25 displaced upward with respect to an axis of the shaft of the strike 20 reflecting a predominance of downward displacement of the strike 20 over time with door sag. Further, the escutcheon aperture 42 may have a peripheral bevel to assist in guiding the bulbous end 26 of the strike 20 into the escutcheon aperture 42 .
Referring now to FIG. 5 , the strike retention mechanism 28 may also provide a locking function preventing engagement or disengagement of the strike 20 . This locking may be accomplished by preventing a separation of the distal ends 62 of the arms 36 after they have received the bulbous end 26 of the strike 20 . In one embodiment, this may be accomplished by means of a locking wedge 70 fixed on the support bracket 30 whose movement along the plane 31 across the distal ends 62 (as shown in FIG. 6 ) presses the distal ends 62 of the U-shaped spring 32 downward out of the plane 31 into an upwardly facing C collar 72 that prevents separation of the arms 36 and thus disengagement of the strike 20 . The locking wedge 70 may be moved by an electrical solenoid or the like.
Referring now to FIGS. 7 a and 7 b , in an alternative embodiment, the separation of the distal ends 62 of the arms 36 of the U-shaped spring 32 , indicated by arrows 73 , may be prevented by sliding of the U-shaped spring 32 with respect to the support bracket 30 into a collar 72 ′ fixed on the support bracket 30 . The sliding is along the plane 31 generally in the direction 75 of the extent of the arms 36 . In this embodiment, the reduced separation 66 portion of the arms 36 is not required and those arms 36 may be substantially straight.
Movement of the U-shaped spring 32 in this manner may be accomplished by an electric actuator 74 attached to the base 39 , directly or through a linkage or the like, to allow both electrically controlled unlocking and locking with opposite motions of the electric actuator 74 . The electric actuator 74 may be any of a variety of electric actuators including single solenoids with permanent magnet cores, a single solenoid with a spring bias, opposed dual solenoids with standard ferromagnetic cores, wax motors, and bimetallic elements, electric motors, or the like.
Referring now to FIGS. 8 a and 8 b , in an alternative embodiment, the U-shaped spring 32 may remain stationary with respect to the support bracket 30 and a collar 72 ″ may be moved into engagement (as shown in FIG. 8 a ) or disengagement (as shown in FIG. 8 b ) about the distal ends 62 of the U-shaped spring 32 . The collar 72 ″ may be mounted on a lever arm 76 to pivot about a pivot point 78 of the support bracket 30 under the control of actuator 74 ′. The actuator 74 ′ may be attached to an extension 77 of lever arm 76 on an opposite side of the pivot point 78 . This extension 77 may be in turn attached to a switch linkage 80 by a slide/pivot connection 82 . Movement of the extension 77 moves the switch linkage 80 about a pivot point 81 so that its end 83 opposite slide/pivot connection 82 opens a set of contacts 84 when the collar 72 ″ is disengaged from the distal ends 62 (as shown in FIG. 8 a ). When the collar 72 ″ is engaged with the distal ends 62 , preventing their separation and locking an engaged strike 20 , the end 83 is displaced from the contacts 84 so as not to interfere with their closing.
This embodiment may also provide for a pivoting strike sensor 86 having a first end 88 positioned between the arms 36 and within the opening 22 as shown in FIG. 8 a . In this state, a second end 90 of the strike sensor 86 also engages the contacts 84 to hold them open independent of the end 83 of the switch linkage 80 when the strike 20 has not been received. As shown in FIG. 8 b , when the strike 20 is engaged it presses the end 88 of the strike sensor 86 away from the opening 22 causing the strike sensor 86 to pivot about a pivot point 100 displacing end 90 away from the contacts 84 so as not to prevent their closure.
The result is that the contacts 84 may close only when both the collar 72 ″ is engaged on the distal ends 62 locking the strike 20 into the strike retention mechanism 28 and the strike 20 is engaged by the U-shaped spring 32 . This approach provides reduced wiring for the communication of both lock state (indicating a locking of the strike retention mechanism 28 ) and door closure state (indicating engagement of the strike 20 with the U-shaped spring 32 ).
In one embodiment, (shown in FIG. 8 b ) unlocking motion of the collar 72 ″ after it has been engaged on the distal ends 62 of the arms 36 may be prevented by a stop 102 inserted in the path of the extension 77 (or on any connected linkage) that would be traversed during that unlocking motion. The stop 102 may be moved into position by a wax motor or bimetallic strip actuator 104 wired in parallel or series with actuator 74 ′, the latter which may be a fast acting solenoid. In this manner a fast locking may be obtained through the action of actuator 74 ′ (being one or more solenoids) after which time the stop 102 will be placed according to the thermal time constant of the actuator 104 . In the event of power loss, the stop 102 will retain lock of the strike retention mechanism 28 for a period of time required for cooling of the actuator 104 preventing, for example, premature access to the appliance while parts may be in motion.
Alternatively, the actuator 74 ′ may be used alone and may be a thermal actuator if a slow locking speed may be tolerated.
The present invention contemplates that the arms 36 of the U-shaped spring 32 may be coated with a friction reducing substance such as a thermoplastic or may incorporate rollers or the like at points of contact with the strike 20 for the similar purpose, and/or that the strike 20 may be thermoplastic or have a thermoplastic coating over a metal core for similar friction reduction. The U-shaped spring 32 need not in all embodiments be formed of a single metal rod, but may be formed from two wires that are welded together or otherwise attached.
Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “left”, “right”, “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence, or order unless clearly indicated by the context.
When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. | A door latch for an appliance provides a U-shaped spring for engaging a strike having an expanded tip and passing between the arms of the U-shaped spring in a direction substantially perpendicular to the extent of those arms. Locking of the latch may be provided by collaring the distal ends of the arms to prevent their expansion once the strike is engaged. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method of producing carbon nanoparticles, and to carbon nanoparticles so produced.
BACKGROUND OF THE INVENTION
[0002] Carbon nanoparticles may be produced by various routes, including catalytic vapour deposition (CVD), arc discharge and laser ablation.
[0003] The CVD route has advantages of low cost and scalability. There has therefore been significant interest in this route.
[0004] Typically, in the CVD route, a gaseous carbon source such as a hydrocarbon or carbon monoxide is decomposed by a metallic catalyst in a heated reactor under suitable reaction conditions. Carbon nanoparticles (for example carbon nanotubes) are deposited.
[0005] The catalyst may be either supported by a substrate or suspended in the gas stream. The catalyst may be introduced into the reactor in the following ways:
1. Placing a supported catalyst or catalyst precursor (e.g. ferrocene, iron pentacarbonyl) into the reactor and then introducing a gaseous carbon source into the reactor. This is the fixed bed method. The supported catalyst may be made by sputtering catalyst metal onto a substrate, by oxidation of a metal salt followed by reduction (WO 00/73205), by impregnation of a metal salt into a high surface area substrate [Geng 02], or by a sol-gel reaction using precursors containing the catalyst elements and the support materials [Su 00, Flauhaut 99], or by in situ thermal decomposition of a supported catalyst precursor. 2. Introducing the catalyst in the form of a precursor directly into the gaseous carbon source in the heated reactor to produce catalytic metal particles in situ by thermal decomposition. The metal catalyst is suspended in the reaction gas mixture [WO 00/26138]. 3. Introducing the catalyst in the form of a precursor directly into the gaseous carbon source in the heated reactor to deposit catalytic metal particles onto solid supports held within the reactor [Singh 03]. 4. Introducing the catalyst and substrate into the furnace, where upon they react, as described in WO02/092506.
[0010] The most commonly used process for synthesizing nanoparticles is the fixed-bed method. In the fixed-bed method, the supported catalyst is heated slowly within the heated reactor. Some fixed-bed supported catalyst systems produce nanotubes, while others yield only amorphous carbon or carbon capsulated metal particles. There is often failure to produce carbon nanotubes, and in particular failure to produce single-walled nanotubes [Li and summary of WO 0017102].
[0011] A promising process for large-scale synthesis of carbon nanotubes is the fluidised bed method. Fluidised-bed processes are well-established in chemical engineering. Such processes have the advantage of enhancing gas-solid mixing so as to increase reaction efficiency and provide uniform products.
[0012] Fluidised bed methods have been used for production of multi-walled carbon nanotubes. These methods have been carried out by introducing supported catalyst into a heated fluidised bed reactor followed by slow heating to a synthesis temperature [Wang, Carbon].
[0013] Some workers use an additional reduction step in hydrogen prior to the nanotube synthesis reaction [Wang,Bachilo]). Recently, Bachilo et al. and Mauron et al. have reported the production of single-walled nanotubes from salt impregnated silica which was oxidised and then reacted [Bachilo, Mauron].
[0014] Fluidised bed methods also suffer from the disadvantage which applies to the fixed-bed method of failure to produce carbon nanotubes and in particular failure to produce single-walled carbon nanotubes.
SUMMARY OF THE INVENTION
[0015] In a first aspect, the present invention provides a method of producing carbon nanoparticles, comprising the steps of:
passing a gaseous carbon source through a heated reactor; and adding catalyst supported on substrate particles or thermally decomposable catalyst precursor supported on substrate particles to the heated reactor; maintaining a fluidised bed of the substrate particles in the heated reactor; and forming carbon nanoparticles in the heated reactor.
[0020] The particles bearing the catalyst or precursor are added to the heated reactor in the presence of the gaseous carbon source. Preferably, the particles are thereby rapidly heated from a temperature at which they can be stored without deterioration in their nanoparticles forming properties to the temperature of the heated reactor. In an example described below is of the order of 10 2 -10 3 ° C./min. More generally, a heating rate between 10 and 10 4 ° C./min should be acceptable, but more preferably it should be above 10 2 ° C./min. Preferably, the particles are subjected to said rapid heating from a starting temperature not above 300° C., more preferably not above 100° C., e.g. from around room temperature. Suitably, the heating time from the safe starting temperature to the temperature of the heated reactor is from 0.01-60 seconds, more preferably not exceeding 20 seconds. Generally, the difference in temperature between the storage of the particles before injection and the heated reactor should be from 100 to 1200° C., more preferably 500 to 1000° C.
[0021] Preferably, the catalyst or catalyst precursor supported on substrate particles is introduced into the heated reactor via a gravity-feed hopper. Alternatively or additionally, the catalyst or catalyst precursor supported on substrate particles may be introduced into the heated reactor via an injection gas flow. Thus, the injection gas flow may be used to entrain and carry particles released from a hopper to fall into the gas flow, or the gas flow may be used to lift particles from a bed of particles to carry them into the heated reactor.
[0022] It may be that the injection gas flow reverses the direction of gas flow through the heated reactor or in a portion thereof during injection.
[0023] The injection gas is suitably an inert gas but may also be or may comprise a gaseous carbon source.
[0024] The reactor heated reactor is suitably at a temperature between 500 and 1200° C., more preferably at a temperature between 700 and 900° C.
[0025] When a catalyst precursor is present it is suitably a metal salt, an organometallic species or a metal carbonyl. Such a catalyst precursor may comprise one or more of nickel, iron, molybdenum, platinum and cobalt. Suitably, the catalyst precursor is a metal salt and comprises a counter ion consisting of nitrate, stearate, formate, oxalate, acetate or chloride. The organic counter ions are preferred, for instance C 2 to C 30 carboxylate.
[0026] The carbon nanoparticles may contain a non-carbon dopant such as nitrogen.
[0027] The gaseous carbon source is suitably one or more of acetylene, alcohol, alkane, alkene, CO, benzene, toluene, xylene, cumene, ethylbenzene, naphthalene, phenanthrene, anthracene, formaldehyde, acetaldehyde, or acetone.
[0028] Preferably, the gaseous carbon source is mixed with a diluent gas and preferably the mixture of these gases fluidises the bed of substrate particles. The diluent gas is preferably one or more of hydrogen, ammonia, nitrogen, helium and argon.
[0029] The ratio of gaseous carbon source to diluent gas is preferably reduced while the catalyst or catalyst precursor supported on substrate particles is introduced into the heated reactor, e.g. so that the proportion of the gaseous carbon source in the mixture drops by a from 20 to 100%, so that for instance if during nanoparticles production the ratio is say 1:2 carbon source to diluent, during particle addition the amount of carbon source fed might be reduced so that the ratio is from 2/3:2 (33% reduction) down to 0:2 (100% reduction). More preferably said reduction might be by from 40 to 60%.
[0030] The substrate particles may comprise or consist of one or more of silica, alumina, MCM (a family of mesoporous aluminosilicate molecular sieve materials, including MCM-41), and magnesium oxide. Suitably therefore, the substrate particles comprise a halide, nitrate, sulphate, carbonate, aluminate, aluminium chloride, arsenate, arsenite, borate, chromate, fluoroaluminate, silicate, sulphide, telluride, tungstate, vanadate or phosphate of a Group 1 or Group 2 metal. The Group 1 or Group 2 metal may be lithium, sodium, potassium, calcium or magnesium.
[0031] Suitably, the average dimension of the substrate particles is between 20 microns and 1 mm, more preferably between 40 microns and 200 microns.
[0032] The method according to this first aspect of the invention preferably further comprises the step of removing nanoparticles from the heated reactor. This may be done by the use of vacuum to suck out the particles bearing the nanotubes or by the use of pressure, e.g. the use of a gas jet to blow the particles off the top of the bed for collection.
[0033] The process is preferably operated continuously with continuous or repeated introduction of catalyst or catalyst precursor supported on substrate particles and optionally simultaneous similarly continuous or continual removal of nanoparticles.
[0034] Alternatively, the method is operated non-continuously with alternating batch wise introduction of catalyst or catalyst precursor supported on substrate particles and removal of nanoparticles.
[0035] The carbon nanoparticles produced may be nanotubes and/or nanofibres. Subtle variations in conditions can be used to produced nanoparticles selectively of a desired kind. The nanotubes may be single-walled nanotubes or multi-walled nanotubes.
[0036] In an alternative aspect, the invention includes a method of producing carbon nanoparticles, comprising the steps of:
passing a non-carbon-containing gas through a heated reactor; and adding catalyst or catalyst precursor supported on substrate particles to the heated reactor; maintaining a fluidised bed of said substrate particles in the heated reactor; passing a gaseous carbon source through the heated reactor; and forming carbon nanoparticles in the heated reactor.
[0042] In preferred methods according to either aspect of the invention, efficiency is enhanced by the fact that the supported product particles have a lower density that the supported catalyst particle, and hence are preferentially carried out of the reactor by the fluidising gas flow.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The invention will be further described with reference to a preferred embodiment of the invention (Example 2) and to the figures, in which:
[0044] FIG. 1 shows in schematic sectional side elevation an apparatus for use in the invention.
[0045] FIG. 2 shows Raman spectra of the products synthesized in (a) Example 2 and b) Comparative Example 1.
[0046] FIG. 3 shows SEM micrographs of the products synthesized in (a) Example 2 and b) Comparative Example 1.
[0047] The apparatus shown in FIG. 1 comprises a resistance tube furnace 10 extending vertically and annularly surrounding a vertically running quartz tube 12 having upper and lower end caps 14 , 16 . Within the quartz tube 12 is an inner quartz tube 18 running coaxially therewith from the lower end cap 16 on which it is supported and stopping short of the upper end cap 14 . Approximately half way along its length, the inner quartz tube 18 has a disc 20 of porous silica frit bridging across its bore. An inlet tube 22 for the introduction of a mixture of gaseous carbon source and diluent gas extends through the lower end cap 16 axially into the lower end of the inner quartz tube 18 . An outlet tube 24 for venting gas from the reactor extends from the annular space between quartz tubes 12 and 18 through the lower end cap 16 .
[0048] An inlet tube 26 extends axially through the upper end cap 14 to reach down into the upper part of the inner quartz tube 18 . A hopper 28 for the gravity feed of substrate particles is connected via a ball valve 30 to a port at the top of a horizontal run of the tube 26 and a side arm of said tube leading to said port is connected to a supply 32 of carrier gas.
[0049] In use, the furnace is heated to heat the quartz tubes 12 and 16 to the desired nanotubes forming reaction temperature and a flow of carbon containing gas and diluent gas mixture is established through inlet 22 . Thereafter, substrate particles are dropped from the hopper 28 and displaced by a flow of carrier gas from the side arm of tube 26 to fall into the reaction zone where they are supported on the frit 20 and form a fluidised bed 34 . Carbon nanoparticles then form on the substrate particles.
[0050] The invention will be further described with reference to the following non-limiting examples.
EXAMPLES
Comparative Example 1
[0051] Nickel formate/silica gel particles were prepared by impregnating porous silica gel particles (50 micron in diameter) with a nickel formate aqueous solution. A nickel loading of 3.0 wt % was obtained.
[0052] 100 mg of the supported catalyst particles were placed onto the bed of a fluidised bed reactor containing a porous frit at room temperature. The reactor was purged with argon and was then heated at 10° C./min to the synthesis temperature of 860 C.
[0053] The supported catalyst particles were then fluidised by passing a stream of methane and argon (ratio 1:2) through the bed at a flow rate of 2.0 l/min. After 20 min and subsequent cooling of the system, the products were collected from inside the fluidised reactor and were characterized by Raman spectrometry and scanning electronic microscopy ( FIG. 1 b ), FIG. 2 b )). This showed that only amorphous carbon was formed on the surface of the silica gel particles.
[0054] A similar synthesis was conducted in a horizontal reactor by a fixed-bed method. An identical supported catalyst was placed in an alumina crucible then heated to the reaction temperature in the reaction gas mixture described above. Again, in this case, only amorphous carbon was formed.
Example 2
[0055] A hot-injection synthesis was conducted using the same supported catalyst of Example 1.
[0056] The supported catalyst was held outside the reactor under an inert argon atmosphere whilst the fluidised bed reactor was heated to 860° C. Once the reactor had reached this temperature, the supported catalyst particles were blown into the top of the vertical reactor using argon (600 ml/min) as the carrier gas.
[0057] During addition of the supported catalyst, a methane-argon mixture (ratio 1:2, 2.0 l/min) was kept flowing through the bed. The catalyst particles were fluidized on the bed in a 1:1 methane-argon mixture, at a flow rate of 2.0 l/min, at 860° C. for 20 min.
[0058] As the catalyst was exposed to the carbon source at the high temperature, an immediate colour change of the catalyst particles from their original green colour to brown or black was observed on those particles which were swept out of the fluidised bed reactor.
[0059] SEM observation ( FIG. 1 a )) of the black products collected inside the fluidized bed reactor revealed a distribution of fibrous carbon products on the silica gel particles, and Raman analysis ( FIG. 1 b )) showed that these particles were single walled nanotubes, as demonstrated by the presence of a strong G band at 1585 cm-1 and radial breathing modes at the low frequencies.
Example 3
[0060] The supported catalyst injection method of Example 2 was carried out using pure methane rather than a mixture of methane and argon as the injection gas. The synthesis was carried out under the same conditions as Example 2, using 1:1 methane-argon. Multi-walled carbon nanotubes were grown on the surface of the silica-gel particles rather than single-walled nanotubes.
[0061] The advantages of the method of Example 2 include:
1. The method improves the efficiency of the catalyst, that is, the percentage of catalyst which produces single-walled nanotubes. 2. The addition and subsequent removal of the catalyst while the reactor is hot means that the plant is run more efficiently than a conventional fluidised bed reactor plant. 3. The plant can be run in a continuous or semi-continuous mode. A conventional fluidised bed reactor plant is run in a batchwise mode.
[0065] Without wishing to be bound by theory, the applicants believe that good results are achieved in the method of Example 2 for the following reasons.
[0066] In the fixed-bed method, catalyst particles are formed by thermal decomposition of catalyst precursor during heating. The nature of the catalyst particles is affected by the rate of heating. In particular, slow heating may result in larger catalyst particles because of slow decomposition of the catalyst precursor and ripening of the catalyst particles on the substrate surface after decomposition. This can lead to failure to produce carbon nanotubes, and in particular to failure to produce single-walled nanotubes whose growth requires catalyst particles of similar diameters to the nanotubes (a few nanometres) [Li and summary of WO 0017102]).
[0067] In order to produce carbon nanotubes, it is necessary to form catalyst particles of small size. This can be achieved by rapid heating of the supported catalyst in a highly dispersed state. This leads to the formation of small catalyst particles due to the impeded decomposition of the catalyst precursors. The impeded n heat exposure of the perature so that the hesis high temperature which would be furnace temperature as bearing substrate ctor from cold. er in the vapour phase on the substrates. heating may generate rve the small metallic nucleation of ce means that ripening urface of the substrate ts as soon as it . This condition is met ng rate achieved when the reactor at 500 to rted to produce a sintering since both e inhibited. Therefore . orted catalyst in a post-interparticulate d-bed method where the ause the particles are not contact each of the catalyst in a fixed bed condition, able to cause icles through either ripening on the s.
[0068] Rapid heating of a catalyst precursor has been used in a floating catalyst method to synthesize nanotubes. In this method, a preheated gas was injected into a heated reactor with a catalyst precursor from a cooled nozzle [WO 00/26318]. No catalyst support was used. In the preferred embodiment of the present invention, the catalyst support plays an essential role.
[0069] Whilst the invention has been described with reference to a preferred embodiment, it will be appreciated that various modifications are possible within the scope of the invention.
REFERENCES
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[0071] Wang—Y. Wang, Fei Wei, Guansheng Gu, hao Yu, Agglomerated carbon nanotubes and its mass production in a fluidised-bed reactor, Physica B, 323, 2002, 327-329
The large-scale production of carbon nanotubes in a nano-agglomerate fluidized-bed reactor, CPL, 364 (5-6), 2002, pp 568-572 Yao Wang, Fei Wei, Guohua Luo, Hao Yu and Guangsheng Gu
[0073] Carbon—Vengoni D, Serp P, Feurer, R, Yolande K, Vahlas C, Kalck P, Parametric study for the growth of carbon nanotubes by catalytic chemical vapor deposition in a fludised bed reactor, Carbon 40, 2002, pp 1799-1807
[0074] “Narrow (n,m)-Distribution of Single-Walled Carbon Nanotubes Grown using a Solid Supported Catalyst” S. M. Bachilo, L. Balzano, J. E. Herrera, F. Pompeo, D. E. Resasco and R. B. Weisman, J. Am. Chem. Soc. Submitted (available at http://www.ou.edu/engineering/nanotube/publications.html)
[0075] Li—Li Y, Kim W, Zhang Y, Rolandi M, Wang D, Dai H. Growth of single-walled carbon nanotubes from discrete catalytic nanoparticles of various sizes. Journal of Physical Chemistry B 2001;105:11424-11431
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[0077] Singh C, Shaffer M S P, Windle A H. Production of controlled architectures of aligned carbon nanotubes by an injection chemical vapour deposition method. Carbon 2003:41(2):359-368
[0078] Laurent—Synthesis of carbon nanotubes-Fe-Al2O3 powders. Influence of the characteristics of the starting Al1.8Fe0.02O3 oxide solid solution, Ch. Laurent, A. Peigney, E. Flahaut, A. Rousset, MRS Bulletin, 35, 2000, pp 661-673
[0079] Mauron—Fluidised-bed CVD synthesis of carbon nanotubes on Fe 2 O 3 /MgO, Diam ond and Related materials , Pages 780-785 Ph. Mauron, Ch. Emmenegger, P. Sudan, P. Wenger, S. Rentsch and A. Züttel
[0080] E. Flahaut, A. Govindaraj, A. Peigney, C. Laurent, A. Rousset, C. N. R. Rao, “Synthesis of Single-Walled Carbon Nanotubes using Binary (Fe, Co, Ni) Alloy anoparticles Prepared in Situe by the Reduction of Oxide Solid Solutions,” Chem. Phys. Lett., 300 (1-2) (1999) 236-242.
[0081] M. Su, B. Zheng and J. Liu, “A scalable CVD method for the synthesis of single-walled carbon nanotubes with high catalyst productivity,” Chem. Phys. Lett. 322 (2000) 321-326. | A method of producing carbon nanoparticles comprises the steps of: passing a gaseous carbon source through a heated reactor; and adding catalyst supported on substrate particles or thermally decomposable catalyst precursor supported on substrate particles to the heated reactor to form a fluidised bed; such that carbon nanoparticles are formed in the heated reactor. | 3 |
This application is a continuation of and claims priority to patent application Ser. No. 13/730,821, filed Dec. 28, 2012, issued Feb. 18, 2014 as U.S. Pat. No. 8,650,997, which claims priority to provisional patent application No. 61/582,072 filed Dec. 30, 2011, both of which are hereby incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to machines used in the accurate cutting of tiles of ceramic, porcelain, clay, marble, granite and composites and similar, blocks of wood, quarry tiles, blocks of concrete or clay, blocks of stone, stone materials, slates, conglomerates and similar by the effective use of a sliding trolley on a track or rails above a working table or bed secured upon a support structure. The movement of the trolley is to allow the work piece to engage the cutting tool or blade or disc where in this invention is fixed within the bed structure. It also relates to machines that can be easily transported or moved given their compact and modular construction.
2. Related Art
Conventionally, methods used for the accurate cutting of tiles, concrete blocks, clay bricks, blocks of wood and blocks of stone have never been consolidated into a singular machine, but rather, each machine with a unique object of processing. The cutting of these objects is ordinary within the construction industry where it can be found the intricate use of tiles of porcelain, clay, ceramic, marble, slate and granite each sometimes require unique and diverse cuts for specific sizing. These tiles are both functional and decorative in purpose where their application can be found in interior and exterior floors, walls, columns, counters tops, showers and baths of domestic and commercial buildings, roadways and walkways. Also, blocks of stone, concrete blocks and clay bricks are not all left without alteration requirements since proper building construction necessitates that these alterations be done since they are the principal materials in use.
In many conventional designs there exists in general two methods of engagement. First, a work piece is held fixed or fastened onto a bed surface while a cutting tool attached to a moving arm (pivoted at one end of the bed) is allowed to manually engage the work piece where all measures of control are exercised on the cutting tool. Or, second, a cutting tool is held fixed either above in suspension to the bed surface or partially recessed in the bed surface and the work-piece is made to manually engage the cutting tool either on a supported sliding table or unsupported, which by extension is of least accuracy.
BRIEF SUMMARY OF INVENTION
Accordingly, the limitations and problems as just described in the prior art are obviated according to the present invention as it relates in particular to a machine so designed that a working platform or bed is removably mounted onto a support stand or base with all degree of mobility on natural and man-made surfaces. The bed is disposed over a semi-projected motor driven cutting disc such that an appropriate portion of the disc is available above the bed surface for the cutting process. A trolley track allows manual movement of a trolley mounted on the track to achieve a successful cut. The trolley through its design facilitates the cutting process by securing the work piece using a block guide and providing a through-pass for the cutting disc to engage the work piece on the trolley along the inscribed cut line while the trolley is being moved in the direction of the cutting disc by means of a suitable handle. The rotation of the disc is typically in a direction towards the bed center at the end where the object advances to the cutting disc so as to prevent ground particulates dispersion to the air from the cutting process.
In the non-wood cutting process, a shower sprays water onto the work piece as a cutting aid and dust smother. Effluent water expended during cutting is channelled through a bin and collected in a recycle and filter unit where the water is filtered of entrained particulates by means of a series of filters and baffles and pumped back through the shower by means of a submersible pump, forming a closed-looped water circuit. This system is meritorious, novel and eliminates dust and water pollution associated with these processes since all is collected in the recycle and filter unit and the effluent water is not discharged into the work environment.
The modular design of the recycle and filter unit is a practical feature of embodiments of the present invention, incorporating a shower, water hoses and submersible water pump that collectively, can be utilized in conjunction with systems or machines requiring similar facilities during material cutting of similar type. A drain plug on one end of the unit can be removed to drain the unit through an outlet port; this, together with addition of fresh water, may keep the water turbidity within acceptable measure. A means is available to admit water directly to the shower via a connected water valve without use of the recycle and filter unit as in situations where the submersible water pump were to fail in operation due to electrical power failure or otherwise.
A bin positioned underside the bed serves as an intermediate accumulator and channel for the guided passage of effluent water from the bed surface and thence to the recycle and filter unit via a waste water hose.
The bin as just mentioned is quite unique both in function and design and presents an advantageous effect in the operational features of this machine. By virtue of its existence, there is no concern of water flooding onto or around work areas, neither uncontrolled wood cuttings nor sawdust left to the discretion of the wind, as the bin through its plural functions eliminates these common problems. It must be emphasized that such features are incorporated with the consideration of environmental preservation and cleanliness, which by extension makes for a comfortable work environment and increased worker safety. Such features are not likely seen in conventional machines.
The cutting of wood may be done in collaboration with a wood cutting table top locked onto the machine bed, where a blade slot ensures the cutting blade to be projected sufficiently above the wood cutting table top. A choice of wood cutting blade is discretionary owing to the inherent flexibility of operating modes. In such operation the wood is placed onto the wood cutting table top, a transparent wood cutting shield may be secured to the side of the machine bed and can be aligned and adjusted to provide suitable eye and operator protection. While the blade is in rotation, the wood piece is directed to the cutting blade in a manual fashion so as to cut the wood along inscribed cut lines in an effective and safe manner. The pieces are removed and the process may be repeated. Wood shavings produced during wood cutting operation are contained and directed where they can be easily disposed by disjoining a lower section of the bin to efficiently remove the wood cuttings to an appropriate containment for disposal.
Various means is provided to dismount the machine into several modular units comprising the wood cutting table top, trolley, wood cutting shield, bed with motor and blade arrangement, recycle and filter unit and the bin, where each modular unit may be fitted with handles for easy removal and mounting. The support stand may include both caster wheels for easy mobility and adjustable legs for stationary support.
BRIEF DESCRIPTION OF DRAWINGS
For a comprehensive exposure of the features, nature and advantageous effects of the present invention, reference is now made to the detailed description in conjunction with the associated drawings, in which:
FIG. 1 is an isometric view of an exemplary apparatus in accordance with an embodiment of the present invention.
FIG. 2A is an isometric view of an exemplary apparatus including a mounted trolley in accordance with an embodiment of the present invention.
FIG. 2B is another isometric view of an exemplary apparatus including a mounted trolley in accordance with an embodiment of the present invention.
FIG. 2C is yet another view of an exemplary apparatus including a wood cutting table top and shield in accordance with an embodiment of the present invention.
FIG. 3 is an isometric view of an exemplary trolley apparatus in accordance with an embodiment of the present invention.
FIG. 4 an assembly drawing of an exemplary shaft apparatus including pillow block bearings, saucers, cutting disc and double pulley arrangement in accordance with an embodiment of the present invention.
FIGS. 5A and 5B are isometric views of an exemplary bin apparatus and strainer, respectively, in accordance with an embodiment of the present invention.
FIG. 6 is an isometric illustration of an exemplary recycling and filter unit (partially exploded) including hoses, pump, power supply and cover.
FIG. 7 is an isometric view of an exemplary wood cutting table top in accordance with an embodiment of the present invention.
FIG. 8 is an illustration of a wood cutting shield assembly in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a block, stone, tile and wood cutting apparatus in accordance with an exemplary embodiment of the present invention. The apparatus comprises main support stand 1 which comprises adjustable legs 6 appended at the base that provide stability and lockable wheels 15 that provide means of mobility. Mountable upon support stand 1 is removable bed 2 upon which certain modes of operation are carried out. Handles 13 may be fitted, preferably each short side, to facilitate easy lifting and removing or mounting of bed 2 from or onto support stand 1 .
Bed 2 , much articulated by design, incorporates various features that allow for attachment to other elements of the machine. In accordance with a preferred embodiment and with reference to FIGS. 2A , 2 B and 2 C, frame motor support stand 21 is the attachment support for electrical motor 11 that drives cutting disc 10 via a belt-pulley arrangement. This configuration can provide safety by virtue of its location under bed 2 yet with an acceptable degree of accessibility to facilitate removal or service. Bed support stand 14 may be provided to ensure the independence of bed 2 when disjoined from the main support stand 1 ; as such, bed 2 can remain unaided without care of obliqueness when placed on a natural surface. Frame motor stand support 21 may include belt guard support bracket 20 that connects the belt guard 5 (see FIG. 1 ) in place so as to provide a secure channel for belt movement throughout a straight path where the belt (not shown) engages a double pulley 34 of cutting disc assembly 68 (see FIG. 4 ). With reference to FIG. 4 , cutting disc shaft assembly 68 may include double pulley 34 fixed onto a shaft 33 which may be held in position by, e.g., pillow block bearings 35 . Pillow block bearings 35 may be supported by shaft support plate 19 (see FIG. 1 ) to which the two pillow block bearings 35 are fastened. On an end of shaft 33 distal to bed's 2 interior may be a terminal point of double pulley 34 which is encompassed with the motor shaft (not shown) at the driver end via a drive belt (not shown). This configuration secures the passage and particularly isolates the belt from interference even by merit of its short loop distance. On an end of shaft 33 proximal to bed 2 interior is an access point where cutting disc 10 may be mounted onto shaft 33 ; disc 10 may be held fast into position on the shaft between two saucers 36 . Returning to FIGS. 1 and 2 A-C, access of cutting disc 10 is provided above the surface of bed 2 by means of an adequately sized opening 17 at an interior location of bed 2 thereby allowing the blade 10 to be sufficiently projected above the surface of bed 2 ; this provides an adequate means for engagement of a work piece with blade 10 during operation.
Bed 2 top surface may include a trolley track comprised of one or more rails 12 ; in a preferred embodiment, bed 2 includes two trolley track rails 12 in close proximity to either long outer edge that traverses linearly along the entire bed top surface. Trolley track rails 12 act as a conveyor for trolley 24 and a containment for water expended in the cutting process. Water expended during the cutting process may be contained by a circumscription formed by trolley track rails 12 on both ends and end stops 18 on the other two adjacent sides. The water contained is not confined indefinitely, but may be discharged through opening 17 into bin 3 of bin assembly 67 mounted at the underside. In one embodiment, bin 3 may be supported beneath bed 2 by means of wing flanges 8 inserted through bed slots 71 and secured with pins 72 .
With reference to FIGS. 2A , 2 B and 3 , in one exemplary mode of operation, trolley 24 is provided as a carriage operable to traverse bed 2 . End stops 18 may be provided on either or both extremes of bed 2 . Trolley 24 is configured to support a work piece to safely engage the cutting tool or disc 10 and provides a means to achieve a most accurate cut once set. The movement of trolley 24 may be facilitated by wheels 29 , for example, four small sheaves or grooved-edged metal wheels fitted onto sides of trolley 24 and adequately spaced apart that trolley 24 may roll on trolley tracks 12 on bed 2 unrestricted or without cause of derailment. To promote this movement, handle 28 may be outfitted at an end of trolley 24 as a means of moving and controlling the trolley 24 between both extremes of bed 2 in a very safe manner requiring no worker contact with the work piece.
In order for trolley 24 to slide over the projected cutting disc 10 , access-way 30 is provided throughout the flat horizontal surface 26 of trolley 24 , essentially dividing the flat horizontal surface into two sections which are kept apart and fixed by two supporting end-faces 22 . As such the access-way 30 is continued throughout these end faces 22 just short of its length providing sufficient clearance for the cutting disc to pass uninhibited. The two end-faces 22 are held fast and supported by means of a connecting arm 23 to the top of trolley 24 . A concrete block guide 32 may be placed on one side of the trolley's flat surface 26 and be used to keep the line of cut of the work-piece aligned to the cutting disc 10 ; this is accomplished by the concrete block guide 32 acting as a backing edge that prevents lateral movement of the work-piece on trolley work surface 26 . Easy adjusting and securing of the concrete block guide 32 may be provided by a fastening assembly. In one embodiment, the fastening assembly may comprise two adjustment-nuts 31 disposed to engage corner areas of concrete block guide 32 . With adjustment nuts 31 untightened, the concrete block guide 32 is free to move laterally across the trolley work surface 26 to the point of support to the work-piece. Concrete block guide 32 may then be secured in position by tightening both adjustment nuts 31 . The means provided within trolley 24 to accommodate movement over the blade 10 is effectuated during operation, as such; the operator may place the work-piece onto trolley work surface 26 , fixed and aligned using the concrete block guide 32 . In operation, trolley 24 is manually moved on rails 12 to the other end of the bed 2 surface while the cutting disc 10 effectively passes through the access-way 30 of the trolley, engaging the work-piece. When trolley 24 reaches the other end of bed 2 , the cut would have been concluded where the work piece can then be removed and trolley 24 retracted to the start position. Trolley 24 design and function no longer require the hand of the operator to hold the work-piece to engage the cutting disc 10 as in many conventional machines. This minimizes the potential for unsafe conditions that can arise in operations of this nature.
In one embodiment, trolley 24 may comprise a water shower system including shower 25 which may span trolley 24 above trolley work surface 26 . In accordance with this embodiment, the water shower may provide a very effective medium in the removal of grit produced during cutting operation and to aid as a lubricant to the cutting disc 10 in the cutting of materials other than wood. Shower 25 may comprise a plurality of perforations in linear sequence and in such an arrangement to allow the water to spray onto the entirety of trolley work surface 26 . The water shower system may also include water valve 27 . In one embodiment, water valve 27 may be disposed below handle 28 of trolley 24 . Valve 27 may be used to admit water through shower 25 or to isolate water from shower 25 if water is not required. Water to shower 25 may be supplied through nozzle 69 by hose 52 connected to submersible pump 46 located within recycling and filter unit 4 (see FIG. 6 ). Pump 46 may pump water through supply water hose 52 which may be held stable by means of water hose support 7 mounted onto a water hose support bracket at one side of bed 2 frame. During operation, the silt contained within the effluent water naturally flows through the access-way 30 on trolley 24 and through opening 17 in bed 2 and thus into bin assembly 67 where it is channelled to recycling and filter unit 4 and can return to shower 25 as filtered water. Non circulated water may be admitted directly to shower 25 via connection of a water supply hose to nozzle 69 , bypassing use of the recycle and filter unit 4 as in situations where submersible water pump 46 fails in operation due to electrical power failure or otherwise.
With reference to FIGS. 5A and 5B , bin assembly 67 may be configured as an inverted pyramidal structure with a large open end connected under bed 2 surface in such a way as to follow-through from opening 17 in bed 2 ; the other end of bin assembly 67 is ported by means of waste water nozzle 37 and connects to recycling and filter unit 4 via water nozzle 37 and waste water hose 51 for transmission of waste water to same unit from bin assembly 67 . In the illustrated embodiment, the shape of bin 3 and bin assembly 67 may reduce the structural space required for the machine and can maintain the overall weight within acceptable limits. In the cutting of materials other than wood, a strainer 64 , for example a perforated steel sheet with handle 42 , may be inserted into bin assembly 67 in a horizontal orientation in order to restrict any entrained particulates within the discharged water. The bottom of bin assembly 67 , to which waste water nozzle 37 is attached, may be removed by detaching detachable bottom-section 41 . In one embodiment, detachable bottom-section 41 may be detachably attached by means of a tab, bolt and wing nut assembly (not shown) to the main part of the bin 3 . As such, in a wood cutting mode of operation, strainer 64 may not be required and all wood shavings produced during operation are contained and directed in bin assembly 67 which are easily removed when bin assembly 67 is filled by removing the bottom-section 41 and allowing the contents to fall into a disposable bag (not shown) or any similar disposal method or device. In addition, bin assembly 67 may be outfitted with one or more handles, e.g., handle 38 , for easy lifting and dismounting.
With reference to FIG. 6 , recycling and filter unit 4 is so constructed to be modular in placement in relation to the machine. The said unit may be of rectangular form and reside at the base of the support stand 1 beneath bin assembly 67 where it can be easily removed by simply lifting and removing by the use of handle 43 on one end. Recycling and filter unit 4 may be closed by cover 65 with an appropriately sized inlet 48 that ports waste water hose 51 from bin assembly 67 ; handle 49 may be fitted at the top to accommodate removal of cover 65 and slot 47 may be extended from one end point of cover 65 to a suitable distance within cover 65 to permit the passage of supply water hose 52 and electrical power cable (not shown) to water pump 46 .
In one embodiment, recycling and filter unit 4 comprises a series of chambers in sequential order with the first chamber being the largest and right-most according to FIG. 6 . Cover 50 may be sealed onto the top chamber to create a partial enclosure. Baffle plates 45 may be used to divide the recycling and filter unit 4 into the various chambers
Effluent water leaving the bin assembly 67 enters the first chamber via waste water hose 51 . The water accumulation rate in the first chamber is sufficient that through resident time, the larger of entrained sediments in the effluent water will settle at the bottom. On rising to the top of the chamber, water is filtered through an arrangement of perforations 73 at the top of the baffle plate on one end. This filter process through the baffle restricts entrainments too large to pass through and causes the water to accumulate within a second chamber which, being divided in two, causes water flow to a sub-chamber by means of an opening through the bottom of the baffle plate creating said division. This sub-chamber further filters the water by means of an appropriate voluminous filter such as a sponge (not shown) that utilizes entirely the available space. Water is transmitted to a third chamber by means of an arrangement of perforations 73 on the baffle plate on one end where it enters another sub-chamber and thence to a main chamber by overflowing across a short baffle plate. The water flow from this third chamber to the other two is by similar overflow means into the last chamber where water pump 46 may be disposed to circulate the filtered water.
Filtered waste water manifold 44 may be connected at the outside all chambers of the unit except the first; this manifold 44 allows recycling and filter unit 4 to be easily cleaned out and all chambers drained through said manifold 44 by removing an installed plug (not shown) at the end.
Outlet port 16 may be connected to the inlet chamber at the end of recycle and filter unit 4 to facilitate draining the unit 4 of any retained slush, sediments, water or to flush the unit 4 as required and to provide a means to relieve water from the unit 4 if there is no recycle water circuit due to an exclusion of water pump 46 ; in such case, it is adequate enough to admit non-circulated water through shower 25 , onto the work-piece, through the bin assembly 67 , through the first chamber of the recycle and filter unit 4 and thence through the outlet port 16 as with a natural water flow.
With reference to FIGS. 2C and 7 , in one embodiment, the cutting of wood may be facilitated by the use of a wood cutting table top 63 . Wood cutting table top 63 may be a flat rectangular table with handles 53 located, e.g., centrally on both long sides, to provide lifting support for removal and mounting onto bed 2 . Wood cutting table top 63 may be held fast onto bed 2 by means of slotted plates 57 , configured to engage wood cutting table top lock nuts 9 , so as to lock the wood cutting table top 63 in place by tightening of wood table lock nuts 9 . The position of the wood cutting table top 63 , while mounted and held fast on the bed 2 , provides access to wood cutting disc 10 sufficiently projected through blade slot 70 to facilitate the appropriate cutting of wooden objects. Adjustable bar 58 , of appropriate height and width and of a length that spans the long side of the wood cutting table top 63 and in parallel relation to the cutting disc 10 , may be assembled onto the wood cutting table top 63 by means of supporting members that allow movement of adjustable bar 58 across wood cutting table top 63 up to a point where the finest cut of a wooden object would allow. As such, adjustable bar 58 serves as a guide and support in keeping a wooden object secured in position so as to maintain the cutting mark on the work-piece in-line with the cutting disc 10 , i.e., the line of cut. The supporting members within the constructs of the adjustable bar 58 may comprise nuts 54 that drive through adjustable stops 55 and into the end section of the adjustable bar 58 . The movement of nut 54 screw-in-wise forces adjustable stop 55 onto support 56 where by this action locks adjustable bar 58 in position; this construct may be on both end sides of adjustable bar 58 and provides an effective means to allow easy mobility and locking of adjustable bar 58 . Supports 56 may be configured to fit between track rails 12 such that wood cutting table top 63 is supported on bed 2 by track rails 12 and supports 56 .
With reference to FIG. 8 , in association with the wood cutting table top 63 and the wood cutting process, wood cutting shield assembly 62 may be incorporated as an operator safety guard during the wood cutting operation. Wood cutting shield assembly 62 may comprise a transparent plastic sheet 66 (such as the brand PLEXIGLAS®) of a sufficient area disposed in bracket 59 and connected to arm 60 . The arm 60 may comprise hinge 61 at one end to optimize placement of sheet 66 about rotation A in accordance with the operator's position. Exemplary alternate positions are illustrated in dashed lines as sheet 66 -R 1 and 66 -R 2 . This action, with the combined effort of the horizontal, fully circular movement provided by the arm 60 when inserted in shield assembly mount pivot 40 (see FIG. 2C ) about rotation B, enables the wood cutting shield assembly 62 to disposed in any position that may be required by the operator. Wood cutting shield assembly 62 allows the operator to clearly visualise the cutting process with the adequate eye and face protection that is needed to ensure the safety of the operator. It provides good impact strength to withstand the impact of deflected projectiles discharged during the wood cutting operation.
Adequate electrical power is supplied to an electric motor 11 to more than sufficiently drive the cutting disc 10 via the belt and pulley arrangement. An emergency stop button (not shown) is incorporated to safely switch off the motor when not in use and an adequate over-current protection device (not shown) is connected to the electric motor main supply to ensure protection of the electric motor and other auxiliaries. Submersible water pump 46 , housed within recycling and filter unit 4 , is powered from the electrical supply and is operated by means of a pump switch (not shown) independent of electric motor 11 . A light may be installed (not shown) to give indication of the pump 46 status of ON or OFF as operated. | A machine for accurately cutting tiles, blocks of concrete, clay, blocks of stone and stone materials, wood and wooden materials is described. It may include a support stand which at its top supports a removable bed structure. The bed includes a motor-driven cutting disc recessed-mounted axially along pillow blocks such that a substantial portion of the cutting disc is projected above the bed surface and its mode of rotation is about a fixed centralized axis. Trolley track rails situated on distal ends of both long sides of the bed allow for lateral movement of the trolley above the bed surface to facilitate the cutting operation. During operation the object secured safely on the trolley which is manually moved towards the cutting disc while a perforated shower head sprays water onto the work piece. Water is filtered and recycled back to the shower via the bin situated below the cutting disc and then to the recycle and filter unit. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of PCT Application No. PCT/US2011/051782, filed on Sep. 15, 2011, the entire contents being incorporated by reference herein. This application also claims the benefit of U.S. Provisional Application No. 61/383,132 filed on Sep. 15, 2010, the entire contents being incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] The term “classical physics” in the context of Einstein's Theory of Special Relativity generally refers to Newtonian Physics, which generally includes the branches of physics developed prior to the development of relativity and quantum mechanics. In general, classical mechanics is based on Newton's Laws of Motion, which can be stated as follows:
1. In the absence of a net force, a body is at rest or moves in a straight line with constant speed. 2. A body experience a force F experiences an acceleration that is related to F by F=ma, where m is the mass of the body. Alternatively, forces equal to the time derivative of momentum. 3. Whenever a first body exerts a first force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction.
[0006] The “Theory of Relativity” (or “Relativity” by itself) generally refers to Albert Einstein's Theories of Special Relativity and General Relativity. Einstein's Theory of Special Relativity is often expressed in terms of mass-equivalents or E=mc 2 . According to the Principals of Relativistic Mechanics, the energy and momentum of an object with invariant mass M moving with a velocity v with respect to a given reference frame are given by:
[0000] E=to γ mc 2 p=γ mv
[0000] respectively.
Where γ (the Lorentz factor) is given by:
[0000]
γ
=
1
1
-
(
v
/
c
)
2
.
[0007] The effects that are introduced by the theory of special relativity are wholly unfamiliar to human experience, and the theory itself has aspects that are in conflict with human logic. Yet, all the effects are real and can be measured. Our understanding of the dynamics that create these relativistic effects may be enhanced by a mechanical device that demonstrate the internal dynamics responsible for these effects.
BRIEF SUMMARY OF THE INVENTION
[0008] A mechanical device consisting of a prime mover, and a number of rotating masses. Each mass is rotated simultaneously around centers of rotation in two or three planes that are at right angles to each other. Another part of the device consists of one or a number of timing devices that are all synchronized. These timing devices fix the relationship of the two simultaneous input rotations. One of these rotations has a variable angular velocity, the other can have a constant or variable velocity in a cycle of 360°. In the Lorentz equation γ=1/(1−(v/c) 2 ) 1/2 . The constant “c” is normally defined as the speed of light in this context. However, its meaning herein has been broadened, and c is defined herein to be “THE UNIT GOVERNING VELOCITY OF A DYNAMIC SYSTEM,” and represents the constant angular input velocity of a timing device according to the present invention. The Lorentz equation γ=1/1−(v/c) 2 ) 1/2 forms the mathematical basis for the timing device of the present invention, and (1 (v/c) 2 ) 1/2 is the cosine if v/c is defined as the sine of the angle that resides between the two vectors namely the hypotenuse and the cosine vector of a right angle triangle that occurs twice in one rotation of the timing device. The cosine of that angle is the inverse of a Lorentz factor. In a mechanical device the numerical magnitude of that factor is a result of the internal dimensional relationships. Special relativity uses the Lorentz factor to derive the relative mass or resisting force. External energy is transferred to the interior. In this device the opposite occurs, internal energy creates an internal differential that is equalized by an external acceleration of the total mass. Internal energy is transferred to the exterior.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a partially schematic elevational view of a device according to a first aspect of the invention;
[0010] FIG. 1A is a partially schematic elevational view of a device according to another aspect of the invention;
[0011] FIG. 1B is a partially schematic elevational view of a portion of the device of FIG. 1A ;
[0012] FIG. 2 is a schematic view of a single stage timing device utilized in the device of FIG. 1 ;
[0013] FIG. 3 is a partially schematic isometric view of a timing device at 0° and 360° positions;
[0014] FIG. 4 is a partially schematic isometric view of the timing device of FIG. 4 at a 180° position;
[0015] FIG. 5 is a partially schematic of a mechanical version viewed along the Z-axis;
[0016] FIG. 6 is a mechanical version viewed along the X axis;
[0017] FIG. 7 is an isometric view of a three-ringed coupling;
[0018] FIG. 8 is a relativistic curve a mass describes when subjected to a 45° relative angle of a single-stage timing device;
[0019] FIG. 9 shows the relative dimensions and motions of the centers of rotation of the relativistic curve;
[0020] FIG. 10 is the geometric and dynamic relation the mass is subjected to when it is at point E on the relativistic curve; and
[0021] FIG. 11 is the geometric and dynamic relationships the mass is subjected to it is at point L.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0023] A base relativistic unit may consist of two directional units, (one of these units is shown in FIG. 1 ) one rotating clockwise and the other rotating counterclockwise. A directional unit consists of two mass units, one rotating clockwise and one counterclockwise. All rotations of all masses are timed the same by one or more timing devices. While it can be shown that the requirements of relativity can be satisfied with simultaneous input rotations of a mass in two planes and a timing device, the possibility of providing a third simultaneous input rotation is not excluded.
[0024] With reference to FIG. 1 , a directional unit according to one aspect of the present invention includes a frame 11 having an upper portion 12 and a lower portion 13 that are structurally interconnected as shown schematically by dashed line 14 . A first shaft 15 is rotatably mounted to the lower portion 13 of frame 11 by a bracket 16 and ball bearings 17 . The first shaft 15 is operably interconnected, by shafts and gears to a power source 18 . Power source 18 may comprise an electric motor or other device having a rotating output shaft 19 that is operably interconnected to the first shaft 15 . A second shaft 20 is rotatably mounted to the lower portion 13 of frame 11 for rotation about a vertical axis 25 . As discussed in more detail below, vertical axis 25 comprises the primary center of rotation of directional unit 10 . In the illustrated example, the second shaft 20 is rotatably mounted to lower portion 13 of frame 11 by ball bearings 21 , and the second shaft 20 is operably interconnected with first shaft 15 by gears 22 and 23 , such that powered rotation of first shaft 15 results in rotation of second shaft 20 about vertical axis 25 .
[0025] A primary rotor 30 includes a rigid upper structure 31 , a lower rigid structure 32 , and one or more vertically extending rigid interconnecting structures 33 . The lower structure 32 is rotatably interconnected with second shaft 20 by ball bearings 34 , and upper structure 31 is rotatably interconnected with upper portion 12 of frame 11 by a pin or shaft 35 and ball bearings 34 . Thus, primary rotor 30 rotates about vertical axis 25 relative to frame 11 , as shown by the arrow 36 .
[0026] Directional unit 10 also includes a vertical shaft 40 that is rotatably interconnected to upper structure 31 of primary rotor 30 by a ball bearing 41 . The vertical shaft 40 is rotatably interconnected to interconnecting structure 33 of primary rotor 30 by a bracket 42 and ball bearing 43 . Thus, shaft 40 rotates relative to primary rotor 30 about a vertical axis 45 . Vertical axis 45 , in turn, rotates about vertical axis 25 as primary rotor 30 rotates relatively to frame 11 .
[0027] Vertical shaft 40 is operably interconnected with second shaft 20 by a three-ring coupler or coupling 50 . With further reference to FIG. 7 , three-ring coupler 50 includes input/output shafts/connectors 51 and 52 that are operably connected by rings 53 , 54 , and 55 . Shaft 51 is rigidly interconnected to ring 53 and shaft 52 is rigidly interconnected to ring 55 . Ring 53 is operably interconnected with ring 54 by arms 56 - 58 . Each arm 56 - 58 has opposite ends that are pivotally interconnected with rings 53 and 54 . Ring 54 is interconnected to ring 55 by arms 59 - 61 in a similar manner. Due to the manner in which the rings 53 - 55 are interconnected by the arms 56 - 61 , shafts 51 and 52 must rotate at the same angle or velocity and torque transmitted to either shaft 51 or 52 is transmitted to the other of the two shafts 51 and 52 . Shaft 51 rotates about an axis 62 that is parallel to an axis 63 about which shaft 52 rotates. In general, the axes 62 and 63 may be offset by a distance or dimension 65 that is normal to the axes 62 and 63 . The distance 65 may vary depending upon the positions of the rings 53 - 55 . Various three-ring couplers utilizing the same general configuration as the three-ring coupler 50 shown in FIG. 7 are known in the prior art, such that further details concerning the three-ring coupler 50 are not believed to be required.
[0028] Referring again to FIG. 1 , shaft 52 of three-ring coupler 50 is fixed to second shaft 20 , and shaft 51 of three-ring coupler 50 is fixed to vertical shaft 40 . Thus, vertical shaft 40 rotates at the same angular velocity as second shaft 20 . A gear 68 is fixed to vertical shaft 40 and meshingly engages a gear 69 to thereby cause gear 69 to rotate about an axis 70 . Similarly, a gear 72 is fixed to shaft 40 , and drives a gear 73 for rotation about an axis 74 . The axes 70 and 74 are normal to the axis 45 of shaft 40 . A mass 76 is connected to axis/shaft 70 by an arm 77 , such that it rotates as shown by circle 80 . Similarly, a mass 78 is connected to axis/shaft 74 by an arm 79 and rotates as shown by circle 81 .
[0029] A shaft 85 is also operably connected to power source 18 to provide rotation to shaft 85 . Shaft 85 is operably interconnected to shaft 35 by a timing device 90 . So the relationship of a certain differential in angular velocities, between shaft 35 and shaft 15 , are always maintained. The location of the timing device shown in FIG. 1 is one of the possible locations. It could also be located on the frame near the power source and serve two or more directional units 10 . With further reference to FIGS. 3 and 4 , timing device 90 includes an input shaft 91 that is rigidly connected to a first arm 92 . An output shaft 93 is rigidly connected to a second arm 94 having an elongated slot 95 . Slot 95 may be linear, or it may be curved or be wave-like in order to influence the angular velocity of the mass in a particular plane at certain areas of its path. A pin or shaft 96 is rigidly connected to first arm 92 , and a roller 97 is mounted on pin 96 for reciprocating motion within slot 95 of arm 94 . When the output shaft 93 is at 0° or 360° relative to input shaft 91 , the timing device 90 is oriented as shown in FIG. 3 . The movement of roller 97 in slot 95 is shown by the arrow 98 .
[0030] With further reference to FIG. 2 , AV 1 is the input angular velocity, and it has a constant angular velocity. AV 2 is a constantly changing angular velocity within a cycle of 360°. It will be understood that there is no “start” of a cycle, just as there is no “start” to a circle. The maximum angle differential that occurs between arm C and A ( FIG. 2 ) is the relativistic angle of the unit and it occurs when the angle δ=90° or 270°. These are the only points in time in each cycle of 360° where AV 1 =AV 2 . The maximum differential between the angular velocities AV 1 and AV 2 occurs when δ=180° and β=0°. Both arms A and C ( FIG. 2 ) (arms 92 and 94 in FIGS. 3 and 4 ) are angularly aligned at 180° and at δ=0° and 360°.
[0031] In FIG. 2 , 100 designates the configuration of the device 90 as shown in FIGS. 3 , and 101 designates the configuration shown in FIG. 4. 102 designates a first intermediate position that is between the configurations of FIGS. 3 and 4 (i.e., between 0° and 180°), and 103 designates a second configuration that is also between the configurations of FIGS. 3 and 4 (i.e., between 180° and 360°).
[0032] A timing device 90 may be used for each of the two simultaneous input rotations. AV 1 of the top timing device constitutes the “unit governing velocity.” As shown in FIG. 1 , one of the two rotations of the masses 76 and 78 describing circles 80 and 81 is operably interconnected to shaft 15 , and shaft 35 is operably interconnected to rotate the Masses 76 and 78 with the rotor around axis 25 .
[0033] Masses 76 and 78 rotate in opposite directions ( FIG. 1 ). In the illustrated example, mass 76 rotates in a clockwise direction, and mass 78 rotates in a counterclockwise direction. However, the direction of rotation of masses 76 and 78 could be switched, such that mass 78 rotates in a clockwise direction, and mass 76 rotates in a counterclockwise direction. Mass 76 , arm 77 , and associated structure interconnecting the first mass 76 to the vertical shaft 40 comprise a first mass unit, and the second mass 78 and associated arm 79 and other components comprise a second mass unit 84 . The multiplicity of the masses serves only one of two basic purposes, to neutralize forces in a certain axis by complimentary interference or increases the frequency of the impulse if connected sequentially. The operation of the mass units 82 and 84 will now be described in more detail in connection with FIGS. 5 and 6 .
[0034] The mass units 82 and 84 of FIG. 1 are shown schematically in FIGS. 6 (X-Y Plane) and 7 (Y-Z Plane). Mass units 82 and 84 are substantially the same in operation (other than the direction of rotation of the mass), such that only mass unit 82 is described in detail in connection with FIGS. 5 and 6 . In FIGS. 5 and 6 , a link 105 is rotatably mounted for rotation about a primary axis or center of rotation 25 . This rotation is the same as AV 2 of the timing device 90 shown in FIG. 2 . The link 105 of FIGS. 5 and 6 also corresponds to the primary rotor 30 , including upper and lower structures 31 and 32 shown in FIG. 1 . In FIGS. 5 and 6 the mass center and arm 77 are provided with the angular velocity of AV 1 . The mass center of rotation at 180° is designated 45 A in FIG. 6 , and the mass center of rotation at 0° and 360° is designated 45 in FIG. 6 . Thus, it will be understood that the mass unit 82 of FIGS. 5 and 6 is a somewhat simplified representation of the mass unit utilized to illustrate the operation of the mass units 82 and 84 .
[0035] As shown in FIGS. 5 and 6 , when the mass 76 is at 0° and 360° relative to axes 45 and 25 , the arm 77 is positioned in a “−Y” direction and the distance between primary center 25 and mass 76 equals I+sin α. It will be understood that the angle α is always the same angle in the triangle in the timing device and in the mechanical device described herein. As discussed herein, the angle α is determined by the Lorentz factor. However, as the link 105 rotates about the primary axis or center of rotation 25 (Z axis), the mass moves to the position designated 76 A when the mass 76 is at 180° relative to the axis 45 and its relative distance is only 1−sin α to the primary center 25 . The relative frequency to 1 that results when the mass 76 is at 180° is (1/(1−sin α))/(1+sin α) and relative to the opposite side the relative frequency is:
[0000] ((1/(1−sin α))/(1+sin α)) 1/2 =1/cos α
[0036] If v/c of the Lorentz equation 1/((1−(v/c) 2 ) 1/2 is sin α then ((1 (v/c) 2 ) 1/2 =cos α. The Lorentz factor that is used for relative mass in special relativity and the relative frequency factor of the device coincide when the relationships are the same. A relativistic device always features a relative unity and that unity can adopt any value, from one to infinity. However, the velocity it adopts can never be exceeded by any other velocity of a mass within that system. Also the relativistic factor 1/cos α once established is not influenced by velocity.
[0037] FIGS. 5 and 6 show that the instantaneous centrifugal forces at the opposite 180° positions from the two simultaneous rotations in separate planes 90° from each other are complimentary constructive in one direction (direction 0°) and complimentary destructive in the other direction (direction 180°) relative to the primary center 25 . It will be understood that FIGS. 5 and 6 are not intended to be conclusive with respect to the sum of all directional forces during the time of a complete cycle or one rotation nor is it intended to be conclusive as to the direction or magnitude of the total force differential. It is merely an indicator that a differential exists. A graphical representation concerning what occurs during a complete cycle is shown in FIG. 8 , as discussed below.
[0038] FIG. 8 shows a relativistic curve of a 45° relative angle α, where α is the maximum angular differential of the two rotations of the timing device. The relative angular velocity AV 1 was selected for rotation of the masses 76 and 78 describing circles 80 and 81 ( FIG. 1 ).
[0039] The distances between points F & D and D & G define a relative frequency of the device=(1/FD)/DG, and the effective relative frequency is I/cos α=√(1/FD)/DG=√(1/(1−sin α))*(1/(1+sin α)). T is the time center that is used in order to project the influence of the timing device on the path of the mass. FIG. 8 shows the path a mass 76 or 78 has to follow when subjected to the physical constraints of a single-stage timing device 90 (see also FIG. 1 ). The path of the mass 110 as seen in the X-Y plane is shown in FIG. 8 by the curved line that passes through the points G, E, C, F, C 1 , E 1 , back to G. The relativistic curve shown in FIG. 8 occurs when the primary rotation has a variable angular velocity. T is the center of the time circle and the driver of the total system.
[0040] Referring again to FIG. 8 , the “normal” look of the egg-shaped circle 110 is, in a sense, very misleading. The circle 110 actually consists of four individual curves 111 , 112 , 113 , 114 each with its own relative radius (distance) and relative frequency (angular velocity). There are two small transition areas just after position C and before position C′. (Going clockwise on the relativistic curve on FIG. 11 ) The path of the mass encompasses 360°, but if the degrees of all the individual centers of rotation are added up, they seem to total 450°, the additional 90° or 45° per side are due to the relativistic differential effect. The 450° is really a mirage, purely created by the additional 45° motion at position C by the radial vector shown as member 77 in FIG. 5 .
[0041] Two of the four curves 113 and 114 have the same radius and frequency. The centers of these four individual rotations are located in empty space. Their curves are formed by a projection from the two simultaneous motions of the mass in three planes. None of these virtual centers of rotation coincides with the real centers of rotation D and m in time (the real center of rotation m is a moving center and rotates around center D). These virtual centers of rotation seem to instantaneously move from one position to another, exerting no force whatsoever on the mass due to that motion. (Motion in zero time) Therefore there is no change in energy or velocity of the mass due to the change in radius, but the frequency will change inversely proportionally to the change in radius. Normally it would be expected that the frequency would increase inversely proportional to the square of the relative distance. This is the case when the mass moves towards the center of rotation. However, the difference here is that the center of rotation moves towards or away from the mass.
[0042] FIG. 9 shows the relative dimensions and motions of the centers of rotation of the relativistic curves segments and the relative motion of the mass. T is the center of the time circle that is the driver of the system, through the timing device and represents its relative unity, with a radius of 1 and a frequency of 1 and a mass of 1. As the mass travels from G to F on the relativistic curve the following motions are in evidence:
[0043] The center T of rotation, moves instantaneously to position M′ changing the radius from 1 to 0.707 and the frequency from 1 to 1.414, but not effecting the tangential velocity of the mass.
[0044] It must be understood, that for purposes of simplicity, the following representation has been idealized. The mass therefore has the following properties as it moves from G to E. All quantities are relative to 1:
[0045] The radius=0.707
[0046] The frequency=1.414
[0047] The time=1/1.414=0.707
[0048] The tangential velocity=1
[0049] The radial force=1 2 /0.707=1.414
[0050] The directional velocity in the +y direction at point E=I×0.707=0.707
[0051] The average −y directional force=1.414×0.707×4/π=1.2732
[0052] The relative directional −y momentum=1.2732×0.707=0.9
[0053] The center M′ of rotation of curve 111 moves instantaneously to position K, changing the radius from 0.707 to 1.06 and the frequency to (0.707/1.06) 1.414=0.943, but not effecting the tangential velocity.
[0054] Part of the action occurs after the rotation in the z-y plane when member 77 of FIG. 5 completes 90° from position 0°. At that point member 105 on FIG. 5 has only completed 54.735, therefore the mass is still accelerating radially towards the primary center D, in the +y direction due to the tangential velocity, but starting to decelerate in the same direction due to the rotation in the z-y plane that is now past 90°. Acceleration and deceleration have become complimentary destructive until the rotation in the x-y plane has reached 90° and that is the same position as position C in FIG. 9 . Due to the reduction in the radial force the mass slowed down tangentially and directionally and reduced its frequency. This reduction in velocity and frequency is in evidence at point C. With further reference to FIG. 9 . The center K of the rotation of curve 113 moves instantaneously to position N and the mass displays the following relative properties at C:
[0055] The radius=0.5
[0056] The tangential frequency for the upper curvex=0.943×1.06/0.5=2
[0057] The +y directional velocity at C=0.5
[0058] The +x directional velocity at C=0.5
[0059] The tangential velocity of the mass at C=(0.5 2 +0.5 2 )½=0.707
[0000] With further reference to FIG. 9 and the geometry of the relativistic curve FIG. 11 , the center of rotation N moves to Point H at the same time the mass moves from point C to point L. The motions were parallel to each other and there was no effect on the frequency or velocity of the mass, it constitutes a transition. In the curvature 112 forces from the radial and tangential rotation are complimentary destructive. This is responsible for the relativistic effect.
[0060] Properties of the xy Side, as the Mass Moves from Point L to Point F
[0061] The radius=0.5
[0062] The frequency=2
[0063] The time=0.5
[0064] The effective tangential velocity=0.707
[0065] The radial force=0.707 2 /0.5=1
[0066] The +y relative momentum=1×0.5+0.207=0.707 The above numbers are effective numbers since the +y velocity that enters at point C is the only velocity that can be translated. See geometric mechanical calculation on FIG. 10 .
[0067] Since the effective arc in the −y and the +y direction are both 45° from G to E and from L to F, the adjustment for the directionality factor of 0.9 of the radial force does not have to be accounted for in the relativistic calculation or number. But will have to be taken into account when the relative numbers are converted into real numbers by giving the unit real size, mass and frequency. Therefore,
[0068] The relative +y force=1
[0069] The relative +y directional momentum=1×0.707=0.707
[0070] The relative −y directional momentum=0.707×1.414=−1.000
[0071] The directional relative momentum differential is −0.293 This internal differential is opposed by the total mass of the unit and the mass it is attached to, providing an acceleration for the assembly. The relativistic or Lorentz factor is 1/0.707=1.414
[0072] The purpose of this numerical example is to illustrate that all the relativistic properties have been successfully incorporated into a mechanical device and are all in total agreement with those obtained by special relativity, when both have the same velocity relationships. It further demonstrates that a relativistic propulsion device can be designed to meet a specific need just like any other mechanical device.
[0073] However it is to be understood that the invention may assume various alternative combinations and proportionalities in addition to those already mentioned as follows:
[0074] A third input could be added in the third plane that would not change the concept of the basic system but might be helpful in optimizing its results.
[0075] Four different combinations of rotation and distances are possible resulting in four families of relativistic curves. One relativistic curve of the first family has been shown and described in detail. Since all follow the same process, the general description of the others below should be considered sufficient.
[0076] Family 1
[0077] a) Relationships of angular velocities:
[0078] Mass center of rotation m constant. Primary center of rotation D variable.
[0079] b) Relationship of distances:
[0080] Distance between centers of rotation relative unity 1. Radius of gyration of mass around mass center of rotation relative sin α, (relative to 1)
[0081] Family 2
[0082] a) Relationship of angular velocities:
[0083] Mass center of rotation m variable. Primary center of rotation D constant.
[0084] b) Same as FAMILY 1.
[0085] Family 3
[0086] a) Same as FAMILY 1.
[0087] b) Relationship of distances:
[0088] Distances between centers of rotation relative sin α. Radius of gyration of the mass around the mass center of rotation unity 1.
[0089] Family 4
[0090] a) Same as FAMILY 2.
[0091] b) Same as FAMILY 3.
[0092] In devices where masses rotate in three planes, the mechanical combination of relationships are the same, but there are more possible combinations since three rotations are combined with three distances. Not all combinations are necessarily used for practical exploitation, but all are useful for scientific and research purposes.
[0093] With reference to FIGS. 1A and 1B , a directional unit 10 A according to another aspect of the present invention, includes a frame having upper portions 12 A and 12 B and lower portions 13 A and 14 A. These are structurally interconnected as shown schematically by the dashed line 15 A. A first shaft 16 A is rotatably mounted to the lower frame portion 14 A by ball bearings 17 A and 19 A. The first shaft 16 A is operably connected to a power source 18 A. Power source 18 A may comprise an electric motor or other device having a rotating output that is operably connected to shaft 16 A. A miter gear 21 A is keyed to the top of shaft 16 A and forms the lower gear of the differential assembly 20 A. The operation of the differential assembly 20 A is substantially similar to differential assembly 20 described above. Shaft 16 A is located on the vertical axis 25 A that comprises the primary center of rotation of the directional unit 10 A.
[0094] A primary rotor assembly 30 A includes vertical struts 31 A and 32 A that are joined by top plate 33 A and lower plate 34 A. To lower plate 34 A is fastened a tubular extension 35 A that extends into gear assembly 50 A. To the top plate 33 A is fastened shaft 36 A that is operably connected to the output angular velocity of the timing device 90 A. The operation of the timing device 90 A is substantially the same as timing device 90 described above. Unit 10 A includes four horizontal members 37 A, 38 A, 39 A, and 40 A. Horizontal members 37 A and 38 A support mass unit 82 A, and are rotated by the timing belt system 60 A. Horizontal members 39 A and 40 A support mass unit 84 A that is rotated by timing belt system 61 A. The mass unit 84 A and timing belt system 61 A are substantially the same as the corresponding components described above.
[0095] A shaft 85 A is also connected to power source 18 A to provide rotation to shaft 85 A. Shaft 85 A is operably interconnected to shaft 36 A by a timing device 90 A. Thus, the relationship of a certain differential in angular velocities, between shaft 36 A and shaft 16 A, are always maintained at any given time in a rotation of 360°, regardless of the angular velocity of the power source.
[0096] If the timing device 90 A is used for two simultaneous rotations in two planes as shown in FIG. 1A , one of the two rotations of the masses 76 A and 78 A describing circles 80 A and 81 A is connected to the angular velocity of AV 1 and the rotation to AV 2 . Masses 76 A and 78 A rotate around axis 25 A.
[0097] Masses 76 A and 78 A rotate in opposite directions. In the illustrated example, mass 76 A rotates in a clockwise direction, and mass 78 A rotates in a counterclockwise direction. However, the direction of rotation of masses 76 A and 78 A could be switched, such that mass 78 A rotates in a clockwise direction, and mass 76 A rotates in a counterclockwise direction. Mass 76 A, arm 77 A, and associated components comprise the first mass unit 82 A, and the second mass 78 A and associated arm 79 A and other components comprise a second mass unit 84 A. The multiplicity of the masses serves only one of two basic purposes, namely to neutralize forces in a certain axis by complimentary interference, or to increase the frequency of the impulse if connected sequentially.
[0098] Referring again to FIG. 1A , shaft 36 A of the primary rotor assembly 30 A is operably connected to the timing device 90 A. The primary rotor assembly 30 A rotates about axis 25 A with a constant variable angular velocity (AV 2 ). Shaft 36 A is rotatably supported by bearing 41 A, in upper frame portion 12 A, and bearings 42 A and 43 A in lower frame portion 13 A. Gear 51 A, is mounted on the tubular extension 35 A of the primary rotor assembly 30 A and meshes with gear 52 A that is mounted on shaft 53 A.
[0099] The gear ratio between gear 51 A and 52 A is selected such that shaft 53 A rotates at ½ the angular velocity of the primary rotor assembly 30 A in bearings 54 A, 55 A in lower frame portion 13 A. Gear 56 A is mounted on shaft 53 A and meshes with gear 57 A with a gear ratio of 1 to 1. Gear 57 A is rotatably mounted with bearing 58 A on tubular extension 35 A. The differential U frame 22 A of the differential assembly 20 A is rigidly fastened to gear 57 A and rotates at ½ of the angular velocity in the same direction as the primary rotor assembly 30 A. The differential U frame 22 A is provided with a shaft 23 A rotatably mounted in bearings 24 A and 26 A. Miter gear 27 A is mounted on one side of shaft 23 A and meshes with miter gears 21 A and 28 A. Gear 28 A is mounted on shaft 44 A that resides in the tubular extension 35 A and is rotatably mounted on the lower end with bearing 59 A located in the differential U frame 22 A and at the upper end in bearing 45 A located in lower plate 34 A of the primary rotor assembly 30 A. A counter weight 29 A is also mounted on shaft 23 A with clearance provided between it and gears 21 A and 28 A to balance the differential U frame assembly.
[0100] It will be understood that miter gear 27 A will have an angular velocity of ½ the angular velocity of the primary rotor 30 A plus the angular input velocity of shaft 16 A. Miter gear 28 A and shaft 44 A will then have an angular velocity of miter gear 27 A plus the angular velocity of the differential U frame 22 A or the angular velocity of the primary rotor 30 A plus the angular velocity of the shaft 16 A.
[0101] Referring again to FIG. 1B , at the top end of shaft 44 A is mounted miter gear 46 A that meshes with miter gears 47 A and 48 A. Miter gear 47 A is mounted on shaft 62 A that is rotatably mounted in strut 31 A of the primary rotor 30 A with bearings 63 A and 63 B. Miter gear 48 A is mounted on shaft 64 A that is rotatably mounted in strut 32 A of the primary rotor 30 A with bearings 65 A and 6 B. Since miter gears 47 A and 48 A with their shafts 62 A and 64 A, respectively, rotate also with the primary rotor 30 A around axis 25 A, the angular velocities of miter gears 47 A and 48 A and their respective shafts around their own axes is the angular velocity of miter gear 28 A minus the angular velocity of the primary rotor 30 A and therefore is the same as that of shaft 16 A.
[0102] As shown in FIG. 1B , timing belt pulleys 66 A and 67 A are mounted on shafts 62 A and 64 A respectively. Pulley 66 A drives timing belt 68 A and pulley 67 A drives timing belt 73 A. Timing belt 68 A drives mass unit 82 A via pulley 75 A mounted on shaft 70 A. Shaft 70 A is rotatably supported by horizontal members 37 A and 38 A with bearings 70 B, 70 C, 70 D, and 70 E. Mass arm 77 A (see FIG. 1A ) supports mass 76 A and is rigidly mounted to shaft 70 A. Mass arm 77 A supports mass 76 A and is rigidly mounted to shaft 70 A. Similarly, shaft 74 A is rotatably supported by horizontal members 39 A and 40 A with bearings 74 B, 74 C, 74 D, and 74 E. Mass arm 79 A supports mass 78 A and is rigidly mounted to shaft 74 A.
[0103] Accordingly, it will be understood that the masses rotate simultaneously in two planes, in one plane with the variable angular velocity of shaft 36 A of the primary rotor and in the other plane with the angular velocity of input shaft 16 A. | A mechanical device includes a prime mover, and a number of rotating masses. Each mass is rotated simultaneously around centers of rotation in two or three planes that are at right angles to each other. The device includes one or more timing devices that are synchronized. The timing devices fix the relationship of the two simultaneous input rotations. In this device, internal energy creates an internal differential that is equalized by an external acceleration of the total mass, and internal energy is transferred to the exterior. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an improved method for manufacturing dipeptidyl peptidase-IV inhibitor and an intermediate.
[0003] 2. Description of the Related Art
[0004] DPP-IV is an enzyme functioned as a cleavage of N-terminal dipeptide of peptide having a terminal sequence of H-Xaa-Pro-Y (or H-Xaa-Ala-Y, where Xaa is any lipophilic amino acid, Pro is proline, and Ala is alanine) (Heins J et al. Biophys Acta 1988; 161), and also called DP-IV, DP-4, or DAP-IV. After finding out that DPP-IV degrades glucagon-like protein-1 (hereinafter, called as to GLP-1) that is known to have a powerful effect on a control function of insulin to blood glucose contents after dinner (Mentlein R et al. Eur J Biochem 1993:829-35), a possibility as very powerful therapeutic agent for Type II diabetes is presented, and then a study for developing DPP-IV inhibitor has become faster.
[0005] Merck Company developed triazolo piperazine compound with beta-amino acid structure, sitagliptin, during an investigation about DPP-IV inhibitor. The compound is the first DPP-IV inhibitor for treating Type II diabetes and has now become commercially available under a trademark, Januvia™, around the world after obtaining the new medicine approval from U.S. FDA in 2006. On this matter, Korean Patent Publication No. 2008-0094604 discloses that when triazolo piperazine part of sitagliptin is substituted with piperazinone containing hetero atom, it has an excellent DPP-IV inhibition activity, and also a significantly improved bioavailability as compared to that of the conventional DPP-IV inhibitor; and provides a heterocyclic compound containing new beta-amino group represented by the following Chemical Formula 1, or pharmaceutically acceptable salt thereof, a method for manufacturing the same, and a pharmaceutical composition, which contains the same as an effective component, for preventing and treating diabetes or obesity.
[0000]
[0006] (In the above Chemical Formula 1, X is OR 1 , SR 1 or NR 1 R 2 , where R 1 and R 2 are a lower alkyl of C 1 -C 5 , respectively; and in NR 1 R 2 , R 1 and R 2 may be 5-membered ring to 7-membered ring containing hetero atom, O.)
[0007] As shown in the following Reaction Formula A, Korean Patent Publication No. 2008-0094604 discloses a method for manufacturing heterocyclic compound represented by Chemical Formula 1 with beta-amino group, the method comprising I) preparing a compound represented by Chemical Formula 4 bonded with peptide bond by reacting a compound with beta-amino group represented by Chemical Formula 2 and a substituted heterocyclic compound represented by Chemical Formula 3 using 1-hydroxybenzotriazol (HOBT), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and tertiary amine; and II) reacting the compound represented by Chemical Formula 4 under an acid condition:
[0000]
[0008] (In the above Reaction Formula A, X is the same as defined in the above Chemical Formula 1.)
[0009] At this time, the compound with beta-amino group represented by Chemical Formula 2 in the above Reaction Formula A may be used for manufacturing various DPP-IV inhibitors as disclosed in International Laying-Open Gazettes WO03/000181, WO03/004498, WO03/082817, WO04/007468, WO04/032836, WO05/011581, WO06/097175, WO07/077,508, WO07/063,928, WO08/028,662, WO08/087,560, and the like, besides the production of DPP-IV inhibitor represented by the above Chemical Formula 1, and may be produced through various methods.
[0010] For example, the compound represented by the above Chemical Formula 2 may be produced by using the method as disclosed in J. Med. Chem. 2005; 141 and Synthesis 1997; 873 as shown in the following Reaction Formula:
[0000]
[0011] Specifically, ester compound is obtained through an amine-protecting reaction after reacting (25)-(+)-2,5-dihydro-3,6-dimethoxy-2-isopropylpirazine with 2,4,5-trifluorobenzyl bromide and acid-treating. The ester compound may be again hydrolyzed to obtain 3-(2,4,5-trifluorophenyl)-2-aminopropionic acid; then diazoketone may be formed by using isobutyl chloroformate, tertiary amine such as triethyl amine or diisopropylethyl amine, and diazomethane; and the compound represented by Chemical Formula 2 may be produced by reacting the diazoketone with silver benzoate. However, the reaction as mentioned above has problems that it should be performed at low temperature (−78° C.), or should use an expensive alpha-amino acid and highly risky diazomethane.
[0012] Other method for manufacturing the compound represented by the above Chemical Formula 2 is also known in Tetrahedron: Asymmetry 2006; 205 or similarly Bioorganic & Medicinal Chemistry Letters 2007; 2622, as shown in the following Reaction Formula:
[0000]
[0013] That is, 2,4,5-trifluorophenyl acetic acid is activated using 1,1′-carbonyldiimidazole, and then reacted with mono-methyl potassium malonate to produce beta-keto ester compound. The beta-keto ester compound is reacted with ammonium acetate and ammonium aqueous solution to produce enamine ester, and the ester compound is then reacted with chloro(1,5-cyclooctadiene)rhodium (I) dimer and chiral ferroceny ligand I through a high-pressure hydrogen reaction to produce the compound that is a beta-amino ester having chiral primary amine only. And then, the compound may be hydrolyzed to produce the compound represented by Chemical Formula 2. However, the above-described method has problem that the high-pressure hydrogen reaction should be performed by using an expensive metal catalyst.
[0014] In addition, the method for manufacturing the compound represented by Chemical Formula 2 is also disclosed in International Patent Publication No. WO 04/87650.
[0000]
[0015] Specifically, 2,4,5-trifluorophenyl acetic acid is reacted with 2,2-dimethyl-1,3-dioxane-4,6-dione and oxalyl chloride that are an acid activation reagent and then the resulting product is refluxed in methanol to produce a compound corresponding thereto. The corresponding compound is reacted with (s)-BINAP—RuCl 2 that is a reduction reagent with enantioselectivity through a hydrogen reaction to produce a compound with (S)-coordination, and then the resulting compound is again hydrolyzed and then is coupling-reacted with O-benzylhydroxyamine to produce an intermediate. The intermediate produced as mentioned above may be subjected to a ring condensation reaction in the presence of triphenylphosphine and diisopropylazodicarboxylate and treated with lithium hydroxide aqueous solution to produce the compound represented by Chemical Formula 2 with (R)-coordination also in which an amine group is protected with O-benzyl. However, the above method has a problem that an overall process is long and tedious so that the yield of reaction is low and the reaction should be performed for a long period.
[0016] As mentioned above, the conventionally known method for manufacturing the compound represented by Chemical Formula 2 has several problems such as use of an expensive reagent, long synthesizing time, and low yield, and thus it is not sufficient for a commercial mass-production.
[0017] Furthermore, the compound represented by Chemical Formula 3 may be produced by using the following Reaction Formula as disclosed in Korean Patent Publication No. 2008-0094604:
[0000]
[0018] (In the above Reaction Formula, X is the same as defined in the Chemical Formula 1.)
[0019] Specifically, D-serine methyl ester compound, which is a starting material, is substituted with trityl chloride; then hydroxyl group is again substituted with mesyl group, and then refluxed to convert to aziridine compound.
[0020] The trityl group is removed from the aziridine compound by using trifluoroacetic acid; then the aziridine compound is protected with benzyloxycarbonyl (Cbz), and then is reacted with HX; and Cbz is de-protected to obtain methyl 2-amino-3-substituted carbonate. The intermediate may be produced by using the compound produced by protecting the secondary amine of the compound produced through reacting N-butyloxycarbonyl-2-amino acetaldehyde with a reduction reagent (sodiumcyanoborohydride, sodiumtriacetoxyborohydride, sodiumborohydride, and the like) and the compound, of which secondary amine is protected with benzyloxycarbonyl (Cbz), and the compound of which butyloxycarbonyl (Boc) is de-protected. The compound produced as mentioned above is subjected to a cyclization with trimethyl aluminum (or diisopropylethylamine/ethanol, sodium hydrogen carbonate/methanol, and the like) to de-protect Cbz so that the compound represented by Chemical Formula 3 may be obtained.
[0021] However, the above method has a problem that it also uses an expensive reagent, the time for synthesizing is long, and the yield is low so that it is not suitable for a commercial mass-production.
[0022] Furthermore, since 1-hydroxybenzotriazol (HOBT) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) used for producing the conventional compound represented by Chemical Formula 1 are an expensive reagent, the cost for reaction is high so that it is not suitable for a commercial mass-production.
[0023] For this reason, the present inventors completed the present invention by confirming that the compound represented by Chemical Formula 1 can be economically produced with high yield by using the new method for manufacturing the compounds represented by Chemical Formula 2 and Chemical Formula 3 used with cheaper reagents during the study for a manufacturing method suitable for a commercial mass-production, in which the method uses cheaper reagents; is an economical method; and improves a yield.
SUMMARY OF THE INVENTION
[0024] One object of the present invention is to provide a method for manufacturing a useful compound as an intermediate for manufacturing dipeptidyl peptidase-IV inhibitor.
[0025] Another object of the present invention is to provide an improved method for manufacturing dipeptidyl peptidase-IV inhibitor.
[0026] In order to achieve the objects, the present invention provides a new method for manufacturing an intermediate of dipeptidyl peptidase-IV inhibitor.
[0027] The present invention also provides an improved method for manufacturing dipeptidyl peptidase-IV inhibitor.
[0028] The present invention can be useful for mass-production through reducing the production cost by using cheaper reagents on the reaction and improving the yield.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Hereinafter, the present invention will be described in detail.
[0030] The present invention provides a new method for manufacturing an intermediate of depeptidyl peptidase-IV inhibitor represented by Chemical Formula 2, as shown in the following Reaction Formula 1, the method comprising: (Step a) preparing a compound represented by Chemical Formula 6 by ring-opening of aziridine ring using Grinard reagent in a compound represented by Chemical Formula 5; and (Step b) preparing a compound represented by Chemical Formula 2 by introducing an amine-protecting group after hydrolyzing a compound represented by Chemical Formula 6,
[0000]
[0031] (In the above Reaction Formula 1, PG is a protecting group, and R is a lower alkyl of C 1 -C 5 .)
[0032] Specifically, in the above Step a, the aziridine compound represented by Chemical Formula 5 is reacted with 2,4,5-trifluorophenyl magnesium bromide reagent in the presence of copper bromide (I) dimethyl sulfide complex to produce a ester compound represented by Chemical Formula 6. At this time, the compound represented by Chemical Formula 5 can be commercially purchased or produced by using the known method in the art in which the present invention belongs to. For example, by using methods disclosed in Tetrahedron Letter 1991; 923, Tetrahedron Letter 1993; 6513, Tetrahedron Letter 1992; 6389, Tetrahedron Letter 2004; 821, Tetrahedron Letter 2006; 3509, and the like, acid functional group of N-Boc L-aspartic acid t-butyl ester is activated with isobutylchloroformate at −40° C. to room temperature, and then reacted with sodiumborohydride, i.e., a reduction reagent, to thereby produce a compound of which acid functional group is substituted by alcohol group. And then, the produced compound may be reacted with triphenyl phosphine and diisopropylazodicarboxylate (DIAD) to obtain the compound represented by Chemical Formula 5.
[0033] Next, in Step b, the compound represented by Chemical Formula 6 is hydrolyzed under the condition of acid such as trifluoroacetic acid, hydrochloric acid, sulfuric acid, and the like, and then an amine-protecting group may be introduced to produce the compound represented by Chemical Formula 2. At this time, butoxycarbonyl (Boc) or benzyloxycarbonyl (Cbz) may be used as the amine-protecting group.
[0034] In addition, the present invention provides a new method for manufacturing an intermediate of dipeptidyl peptidase-IV inhibitor represented by Chemical Formula 3, as shown in the following Reaction Formula 2, the method comprising: (Step a′) preparing a compound represented by Chemical Formula 8 by reacting a compound represented by Chemical Formula 7 with an amine group-protected aminoaldehyde compound and a reduction reagent; and (Step b′) preparing a compound represented by Chemical Formula 3 or salt thereof by removing the amine-protecting group by triggering a hydrogen reaction in a compound represented by Chemical Formula 8 and inducing a cyclization,
[0000]
[0035] (In the above Reaction Formula 2, X is the same as defined in the above Chemical Formula 1, and HY is a free acid.)
[0036] Specifically, in the above Step a′, the compound represented by Chemical Formula 7 is reacted with the amine group-protected aminoaldehyde compound and a reduction reagent to produce the compound represented by Chemical Formula 8. At this time, the compound represented by Chemical Formula 7 may be commercially purchased or produced by using the known method in the art in which the present invention belongs to. For example, when X is t-butoxy, D-serine methyl ester hydrochloride is reacted with sodium hydrogen carbonate and benzyloxychloroformate in the presence of tetrahydrofuran at 0° C. to room temperature to protect an amine group, then reacted with isobutyrene gas in the presence of sulfuric acid catalyst at 0° C. to room temperature to produce an intermediate, and then is subjected to hydrogenation in the presence of palladium/carbon catalyst to produce the compound represented by Chemical Formula 7. At this time, the amine group-protected amionaldehyde compound may be aminoaldehyde compound, which can be commercially purchased, of which the amine group is protected with Cbz, and is reacted with the compound represented by Chemical Formula 7 in the presence of sodiumcyanoborohydride and zinc chloride that are the reduction reagent to obtain the compound represented by Chemical Formula 8.
[0037] Next, in the above Step b′, the amine-protecting group is removed from the compound represented by Chemical Formula 8 by causing hydrogenation, and simultaneously the cyclization is induced to produce the compound represented by Chemical Formula 3. At this time, the hydrogenation is preferably performed in the presence of palladium/carbon. In addition, the compound represented by Chemical Formula 3 may be used in the form of acceptable salt, and an acid addition salt that is produced by a free acid is useful as a salt. Organic acid or inorganic acid may be used as the free acid. At this time, the inorganic acid may include hydrochloric acid, bromic acid, sulfuric acid, phosphoric acid, and the like, and the organic acid may include di-p-toluoyl-L-tartrate, citric acid, acetic acid, lactic acid, maleic acid, fumaric acid, gluconate, methanesulfonic acid, acetic acid, glycolic acid, succinic acid, tartaric acid, 4-toluene sulfonic acid, glacturonic acid, embonic acid, glutamic acid, aspartic acid, and the like.
[0038] In addition, the present invention provides a compound represented by the following Chemical Formula 8 that is produced as an intermediate when producing the compound represented by Chemical Formula 2.
[0000]
[0039] (In the above Chemical Formula 8, X is the same as defined in the above Chemical Formula 1.)
[0040] Furthermore, the present invention provides an improved method for manufacturing dipeptidyl peptidase-IV inhibitor represented by Chemical Formula 1, as shown in the following Reaction Formula 3, the method comprising: (Step 1) preparing the compound represented by Chemical Formula 4 by bonding the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3 with peptide bond by reacting them with isochloroformate and a base in the presence of a reaction solvent; and (Step 2) preparing the compound represented by Chemical Formula 1 by removing an amine-protecting group of the compound represented by Chemical Formula 4 produced in the above Step 1,
[0000]
[0041] (In the above Reaction Formula 3, PG is a protecting group, X is the same as defined in the above Chemical Formula 1, and HY is the same as defined in the above Reaction Formula 2.)
[0042] Firstly, Step 1 is to produce the compound represented by Chemical Formula 4 by bonding the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 3 with peptide bond through the reaction of them using isochloroformate and a base.
[0043] For the present invention, the reaction solvent may include toluene, tetrahydrofuran, methylene chloride, acetonitrile, N,N-dimethylformamide, and the like.
[0044] For the present invention, the base may include more than one selected from the group consisting of tertiary amines, such as N-methyl morpholine, isopropylethylamine, triethylamine, pyridine, and the like.
[0045] For the present invention, the compound represented by Chemical Formula 2 or 3 may be commercially purchased or produced by using the known method, or the method as disclosed in the above Reaction Formula 1 or Reaction Formula 2.
[0046] For the present invention, the reaction of the above Step 1 is preferably performed at −20° C. to room temperature, and in the case of get out of the above range, there is a problem that the reaction is difficultly processed so that the yield is reduced.
[0047] Next, Step 2 is to provide the compound represented by Chemical Formula 1 by removing the amine-protecting group from the compound represented by Chemical Formula 4 produced in the above Step 1.
[0048] The removal of protecting group in the above Step 2 may be performed under an acid condition or through hydrogenation. Specifically, when the amine-protecting group is butoxycarbonyl (Boc), it may be removed by reacting under the condition of acid, such as trifluoroacetic acid/dichloromethane, ethyl acetate/hydrogen chloride, diethylether/hydrogen chloride, hydrogen chloride/dichloromethane, methanol/hydrogen chloride, and the like; and when the amine-protecting group is benzyloxycarbonyl (Cbz), the protecting group may be removed through a hydrogenation in the presence of palladium/carbon.
[0049] Dipeptidyl peptidase-IV inhibitor of the present invention represented by Chemical Formula 1 may be used in the form of pharmaceutically acceptable salt, and an acid addition salt produced by pharmaceutically acceptable free acid is useful as a salt. Inorganic acid and organic acid may be used as a free acid. Inorganic acid may include hydrochloric acid, bromic acid, sulfuric acid, phosphoric acid, and the like, and organic acid may include citric acid, acetic acid, lactic acid, maleic acid, fumaric acid, gluconate, methanesulfonic acid, acetic acid, glycolic acid, succinic acid, tartaric acid, 4-toluene sulfonic acid, glacturonic acid, embonic acid, glutamic acid, aspartic acid, and the like. Preferably, hydrochloric acid may be used as inorganic acid and tartaric acid may be used as organic acid.
[0050] The addition salt according to the present invention may be produced by using a general method. For example, the compound represented by Chemical Formula 1 is dissolved in water-miscible organic solvent, such as acetone, methanol, ethanol, acetonitrile, and the like; excess organic acid, or acid solution of inorganic acid is added thereto; and then precipitated or crystallized to produce the addition salt. Subsequently, solvent or excess acid is evaporated from the above mixture and then the mixture may be dried or the precipitated salt may be suction-filtered to obtain the addition salt.
[0051] After producing the intermediates or the compounds represented by Chemical Formulas 1-3 according to the present invention, their molecular structures may be determined by using Infrared Spectroscopy, Proton Nuclear Magnetic Resonance Spectrum, Mass Spectrometry, Liquid Chromatography, X-Ray Structure Determination Method, Polarimeter, and Comparison between the calculated value and actual value of elemental analysis of represented compounds.
[0052] As mentioned above, the manufacturing method according to the present invention can reduce the cost for manufacturing the compound represented by Chemical Formula 1 due to the use of cheaper reagents, and also improve the yield so that it can be used in useful to mass-production.
[0053] Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are only for illustrating, but the present invention is not limited thereto.
Example 1
Preparation of (R)-3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2) from (S)-4-t-butoxy-2-(t-butoxycarbonylamino)-4-oxobutanoic acid
Step 1: Preparation of (S)-t-butyl 3-(t-butoxycarbonylamino)-4-hydroxybutanoate
[0054] 2.0 g of (S)-4-t-butoxy-2-(t-butoxycarbonylamino)-4-oxobutanoic acid and 14 mL of tetrahydrofuran were added to 50 mL flask and then the resulting reaction solution was cooled to 0° C. While the reaction solution was stirred, 1.0 mL of 4-methylmorpholine was dropped, and after 10 minutes, 1.2 mL of isobutylchloroformate was dropped, and then stirred for 1 hour. The produced solid was filtered with diatomite, was washed with 14 mL of tetrahydrofuran, and then the filtrate was cooled to 0° C. 523 mg of sodium borohydride was added to the cooled filtrate, and stirred for 4 hours while the reaction temperature was naturally increased to room temperature. After completing the reaction, the reaction solution was cooled to 0° C. and then 10 mL of ammonium chloride aqueous solution was dropped. 20 mL of ethyl acetate and 10 mL of water were added and then stirred for 10 minutes. An organic layer was isolated, dehydrated with magnesium sulfate and then concentrated under reduced pressure. A concentrated residue was isolated with column chromatography (n-hexane:ethyl acetate=2:1) and then concentrated under reduced pressure to obtain 1.86 g of a title compound.
[0055] 1 H NMR (CDCl 3 , 400 MHz) δ 5.19 (s, 1H), 3.94 (br, 1H), 3.67 (s, 2H), 2.46 (m, 3H), 1.43 (s, 9H), 1.42 (s, 9H)
Step 2: Preparation of (S)-t-butyl 2-(2-t-butoxy-2-oxoethyl)aziridine-1-carboxylate (Chemical Formula 5)
[0056] 2.90 g of triphenylphosphine and 15 mL of tetrahydrofuran were added to 100 mL flask and the resulting reaction solution was cooled to 0° C. 2.17 mL of diisopropylazodicarboxylate was dropped while the reaction solution was stirred. After 30 minutes, 10 mL of tetrahydrofuran solution with 1.52 g of (S)-t-butyl 3-(t-butoxycarbonylamino)-4-hydroxybutanoate was dropped and stirred for 16 hours while the reaction temperature was naturally increased to room temperature. After completing the reaction, 40 mL of ethyl acetate and 40 mL of water were added to the reaction solution and then stirred for 10 minutes. An organic layer was isolated, dehydrated with magnesium sulfate, and then concentrated under reduced pressure. A concentrated residue was isolated with column chromatography (n-hexane:ethyl acetate=15:1) and then concentrated under reduced pressure to obtain 1.04 g of a title compound.
[0057] 1 H NMR (CDCl 3 , 400 MHz) δ 2.69 (m, 1H), 2.61 (dd, 1H), 2.31 (d, 1H), 2.16 (dd, 1H), 1.97 (d, 1H), 1.44 (d, 18H)
Step 3: Preparation of (R)-t-butyl 3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoate (Chemical Formula 6)
[0058] 4.2 mL of 1-bromo-2,4,5-trifluorobenzene and 10.8 mL of tetrahydrofuran were added to 50 mL flask and the resulting reaction solution was cooled to 0° C. 15 mL of isopropylmagnesium chloride [2.0 M tetrahydrofuran solution] was dropped to the reaction solution under nitrogen atmosphere and stirred for 30 minutes to produce Grinard reagent. 1.95 g of (S)-t-butyl 2-(2-t-butoxy-2-oxoethyl)aziridine-1-carboxylate and 50 mL of tetrahydrofuran were added to another 250 mL flask and the resulting reaction solution was cooled to 0° C. And then, 778 mg of copper (I) bromide dimethylsulfide complex was added. 22.7 mL of the Grinard reagent produced under nitrogen atmosphere was dropped, and stirred for 6 hours while the reaction temperature was maintained at 0° C. After completing the reaction, 50 mL of ammonium chloride aqueous solution was dropped to the reaction solution; 100 mL of ethyl acetate and 50 mL of water were added and then stirred for 10 minutes. An organic layer was isolated, dehydrated with magnesium sulfate, and then concentrated under reduced pressure. A concentrated residue was isolated with column chromatography (n-hexane:ethyl acetate=20:1) and then concentrated under reduced pressure to obtain 2.62 g of a title compound.
[0059] 1 H NMR (CDCl 3 , 400 MHz) δ 7.02 (m, 1H), 6.87 (m, 1H), 5.11 (br, 1H), 4.07 (br, 1H), 2.82 (dd, 1H), 2.77 (dd, 1H), 2.45 (dd, 1H), 2.35 (dd, 1H), 1.44 (s, 9H), 1.35 (s, 9H)
Step 4: Preparation of (R)-3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2)
[0060] 1.31 g of (R)-t-butyl 3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoate, 16 mL of methylene chloride, and 16 mL of trifluoroacetic acid were added to 100 mL flask and the resulting reaction solution was stirred for 6 hours. After completing the reaction, the reaction solution was concentrated under reduced pressure and 16 mL of methanol was added to the concentrated residue. The reaction solution was cooled to 0° C., 2.82 g of sodium hydrogen carbonate and 0.77 mL of di-t-butyl dicarbonate were added, and then stirred for 6 hours while the reaction temperature was naturally increased to room temperature. After completing the reaction, the reaction solution was concentrated under reduced pressure; then 30 mL of ethyl acetate and 30 mL of water were added; and then stirred for 10 minutes. An aqueous layer was isolated, cooled to 0° C., and then 2 N hydrochloric acid aqueous solution was dropped to adjust to pH 3-4. The aqueous layer was extracted with methylene chloride:methanol=10:1 solvent, dehydrated with magnesium sulfate, and then concentrated under reduced pressure to obtain 828 mg of a title compound.
[0061] 1 H NMR (CDCl 3 , 400 MHz) δ 7.04 (m, 1H), 6.89 (m, 1H), 6.08 (br, 1H), 5.04 (br, 1H), 4.13 (br, 1H), 2.88 (br, 2H), 2.62 (m, 2H), 1.36 (s, 18H)
[0062] Mass (M+Na): 356
Example 2
Preparation of (R)-3-(benzyloxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2) from (S)-4-t-butoxy-2-(t-butoxycarbonyl)-4-oxobutanoic acid
[0063] 64 mg of 3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoate was produced by using the same method with that of Steps 1 to 3 of Example 1. For Step 4 of Example 1, tetrahydrofuran/water and N-(benzyloxycarbonyloxy)succinimide were used instead of methanol and di-t-butyl dicarbonate, respectively, to obtain 40 mg of a title compound.
[0064] 1 H NMR (CDCl 3 , 400 MHz) δ 7.45-7.18 (m, 5H), 7.05 (m, 1H), 6.83 (m, 1H), 5.37 (d, 1H), 5.10 (s, 2H), 4.52-4.16 (m, 1H), 3.01-2.85 (m, 2H), 2.78-2.42 (m, 2H)
[0065] Mass (M+1): 368
Example 3
Preparation of (R)-3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2) from (S)-4-benzyloxy-2-(t-butoxycarbonylamion)-4-oxobutanoic acid
Step 1: Preparation of (S)-benzyl 3-(t-butoxycarbonylamino)-4-hydroxybutanoate
[0066] 402 mg of a title compound was obtained by using the same method with that of Step 1 of Example 1, except that (S)-4-(benzyloxy)-2-(t-butoxycarbonylamino)-4-oxobutanoic acid (500 mg) was used instead of (S)-4-t-butoxy-2-(t-butoxycarbonylamino)-4-oxobutanoic acid in Step 1 of Example 1.
[0067] 1 H NMR (CDCl 3 , 400 MHz) δ 7.27 (m, 5H), 5.16 (m, 3H), 4.00 (m, 1H), 3.68 (m, 2H) 2.66 (m, 2H), 2.40 (s, 1H), 1.41 (s, 9H)
Step 2: Preparation of (S)-t-butyl 2-(2-benzyloxy-2-oxoethyl)aziridine-1-carboxylate (Chemical Formula 5)
[0068] 239 mg of a title compound was obtained by using the same method with that of Step 2 of Example 1, except that (S)-benzyl 3-(t-butoxycarbonylamion)-4-hydroxybutanoate (402 mg) was used instead of (S)-t-butyl 3-(t-butoxycarbonylamino)-4-hydroxybutanoate in Step 2 of Example 1.
[0069] 1 H NMR (CDCl 3 , 400 MHz) δ 7.34 (m, 5H), 5.13 (m, 2H), 2.59 (m, 2H) 2.37 (m, 2H), 1.99 (d, 1H), 1.43 (s, 9H)
Step 3: Preparation of (R)-benzyl 3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoate (Chemical Formula 6)
[0070] 58 mg of a title compound was obtained by using the same method with that of Step 3 of Example 1, except that (S)-t-butyl 2-(2-benzyloxy-2-oxoethyl)aziridine-1-carboxylate (100 mg) was used instead of (S)-t-butyl 2-(2-t-butoxy-2-oxoethyl)aziridine-1-carboxylate in Step 3 of Example 1.
[0071] 1 H NMR (CDCl 3 , 400 MHz) δ 7.37 (m, 5H), 6.96 (m, 1H), 6.86 (m, 1H), 5.11 (m, 3H), 4.12 (m, 1H), 2.81 (m, 2H) 2.56 (m, 2H), 1.35 (s, 9H)
Step 4: Preparation of (R)-3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2)
[0072] 58 mg of (R)-benzyl 3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoate, 3 mL of methanol, and 20 mg of 10 wt % palladium/carbon were added to 25 mL flask and the resulting reaction solution was stirred. A hydrogen gas was bubbled for 2 hours at room temperature; the reaction solution was filtered by passing through celite, washed with 15 mL of ethyl acetate, and the filtrate was concentrated under reduced pressure to obtain 44 mg of a title compound.
[0073] 1 H NMR (CDCl 3 , 400 MHz) δ 7.04 (m, 1H), 6.89 (m, 1H), 6.08 (br, 1H), 5.04 (br, 1H), 4.13 (br, 1H), 2.88 (br, 2H), 2.62 (m, 2H), 1.36 (s, 18H)
[0074] Mass (M+Na): 356
Example 4
Preparation of (R)-3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2) from (S)-2-(t-butoxycarbonylamino)-4-methoxy-4-oxobutanoic acid
Step 1: Preparation of (S)-methyl 3-(t-butoxycarbonylamino)-4-hydroxybutanoate
[0075] 1.23 g of a title compound was obtained by using the same method with that of Step 1 of Example 1, except that (S)-2-(t-butoxycarbonylamino)-4-methoxy-4-oxobutanoic acid (2.0 g) was used instead of (S)-4-t-butoxy-2-(t-butoxycarbonylamino)-4-oxobutanoic acid in Step 1 of Example 1.
[0076] 1 H NMR (CDCl 3 , 400 MHz) δ 5.19 (s, 1H), 3.97 (m, 1H), 3.68 (m, 5H), 2.62 (m, 2H), 2.45 (s, 1H), 1.42 (s, 9H)
Step 2: Preparation of (S)-t-butyl 2-(2-methoxy-2-oxoethyl)aziridine-1-carboxylate (Chemical Formula 5)
[0077] 820 mg of a title compound was obtained by using the same method with that of Step 2 of Example 1, except that (S)-methyl 3-(t-butoxycarbonylamino)-4-hydroxybutanoate (1.23 g) was used instead of (S)-t-butyl 3-(t-butoxycarbonylamino)-4-hydroxybutanoate in Step 2 of Example 1.
[0078] 1 H NMR (CDCl 3 , 400 MHz) δ 3.68 (s, 3H), 2.72 (m, 1H), 2.65 (dd, 1H), 2.35 (m, 2H), 1.98 (d, 1H), 1.43 (s, 9H)
Step 3: Preparation of (R)-methyl 3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoate (Chemical Formula 6)
[0079] 53 mg of a title compound was obtained by using the same method with that of Step 3 of Example 1, except that (S)-t-butyl 2-(2-methoxy-2-oxoethyl)aziridine-1-carboxylate (70 mg) was used instead of (S)-t-butyl 2-(2-t-butoxy-2-oxoethyl)aziridine-1-carboxylate in Step 3 of Example 1.
[0080] 1 H NMR (CDCl 3 , 400 MHz) δ 6.96 (m, 1H), 6.87 (m, 1H), 5.09 (br, 1H), 4.10 (br, 1H), 3.69 (s, 3H), 2.83 (m, 2H), 2.56 (m, 2H), 1.36 (s, 9H)
Step 4: Preparation of (R)-3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2)
[0081] 53 mg of (R)-methyl 3-(t-butoxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoate, 1.5 mL of tetrahydrofuran, and 0.5 mL of water were added to 25 mL flask and the resulting reaction solution was cooled to 0° C. 7.32 mg of lithium hydroxide was added to the reaction solution and stirred for 6 hours while the reaction temperature was naturally increased to room temperature. After completing the reaction, 5 mL of ethyl acetate and 5 mL of water were added to the reaction solution and stirred for 10 minutes. An aqueous layer was isolated, cooled at 0° C., and 2 N hydrochloric acid aqueous solution was dropped to adjust to pH 3-4. The aqueous layer was extracted with methylene chloride:methanol=10:1 solvent, dehydrated with magnesium sulfate, and then concentrated under reduced pressure to obtain 40.8 mg of a title compound.
[0082] 1 H NMR (CDCl 3 , 400 MHz) δ 7.04 (m, 1H), 6.89 (m, 1H), 6.08 (br, 1H), 5.04 (br, 1H), 4.13 (br, 1H), 2.88 (br, 2H), 2.62 (m, 2H), 1.36 (s, 18H)
[0083] Mass (M+Na): 356
Example 5
Preparation of (R)-3-(t-butoxymethyl)piperazine-2-one or Salt Thereof (Chemical Formula 3)
Step 1: Preparation of (R)-methyl 2-(benzyloxycarbonylamino)-3-t-butoxypropanoate
[0084] 130 L of methylene chloride was added; 20.5 g of (R)-methyl 2-(benzyloxycarbonylamino)-3-hydroxypropanate to a reactor; then stirred for 30 minutes; and then 0.4 kg of sulfuric acid was added. Isobutylene gas was bubbled for 24 hours while its temperature was maintained at 20-25° C. After completing the reaction, 18 L of saturated sodium hydrogen carbonate aqueous solution was slowly added, stirred for 1 hour, and then an organic layer was isolated. 5 kg of sodium sulfate was added to the organic layer, stirred for 1 hour, filtered, washed, and then the filtrate was concentrated under reduced pressure to obtain 29.3 kg of a title compound.
[0085] 1 H NMR (CDCl 3 , 400 MHz) δ 7.36-7.30 (m, 5H), 5.59 (d, 1H), 5.10 (s, 2H), 4.44 (m, 1H), 3.80 (m, 1H), 3.73 (s, 3H), 3.56 (m, 1H), 1.10 (s, 9H)
Step 2: Preparation of (R)-methyl 2-amino-3-t-butoxypropanoate (Chemical Formula 7)
[0086] 330.0 L of methanol was added and 66.0 kg of (R)-methyl 2-(benzyloxycarbonylamino)-3-t-butoxypropanoate was added to a hydrogen reactor; and then purged with nitrogen. 4.95 kg of palladium/carbon (10% water mixture) was added and hydrogen was filled to maintain at 5 bar of pressure. It was stirred for 60 minutes, filtered, washed, and then concentrated under reduced pressure. 132.0 L of ethyl acetate and 88 L of water were added to a concentrated residue; stirred for 10 minutes; an organic layer was isolated (in 6 times), dehydrated, and then concentrated under reduced pressure to obtain 27.5 kg of a title compound.
[0087] 1 H NMR (CDCl 3 , 400 MHz) δ 4.21 (m, 1H), 3.82 (s, 3H), 3.74-3.88 (m, 2H), 1.20 (s, 9H)
Step 3: Preparation of (R)-methyl 2-(2-(benzyloxycarbonylamino)ethylamino)-3-t-butoxypropanoate (Chemical Formula 8)
[0088] 155 L (122.5 kg) of methanol and 5.04 kg of sodiumcyanoborohydride were added to a first reactor, cooled to less than 0° C., and then 5.47 kg of zinc chloride was added. 155 L of methanol and 31 kg of 2-oxoethylcarbamate were added to a second reactor, cooled to 0° C., and then 28.1 kg of (R)-methyl 2-amino-3-t-butoxypropanoate was added. The solution produced in the first reactor was immediately dropped to the second reactor; its temperature was increased to room temperature, and then stirred for 2 hours. After completing the reaction, the reaction solution was concentrated under reduced pressure; 93 L of ethyl acetate and 186 L of isopropylether were added; stirred for 5 minutes; the resulting solid was filtered with celite pad; and then washed with isopropylether:ethyl acetate=2:1 (93 L). The filtrate was washed with 310 L of saturated sodium hydrogen carbonate in 7 times and then washed with 310 L of brine. An organic layer was dehydrated with 50.0 kg of sodium sulfate, filtered, washed, and then concentrated under reduced pressure to obtain 35.5 kg of a title compound.
[0089] 1 H NMR (CDCl 3 , 400 MHz) δ 7.36-7.28 (m, 5H), 5.09 (s, 2H), 3.72 (s, 3H), 3.71-3.52 (m, 3H), 3.33 (m, 4H), 1.13 (s, 9H)
Step 4: Preparation of (R)-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 3)
[0090] 39.5 kg of (R)-methyl 2-(2-(benzyloxycarbonylamino)ethylamino)-3-t-butoxypropanoate was dissolved in 276 L of methanol in a reactor; purged with nitrogen; 5.9 kg of palladium/carbon (10% water mixture) was added and stirred for 3 hours while the hydrogen pressure was maintained at 10 bar. The reaction solution was filtered, concentrated under reduced pressure, and then again azeotroped by adding 30 L of isopropylether. 158 L (115 kg) of isopropylether, 39 L (35 kg) of ethyl acetate, and 36.4 kg of silica gel were added to a concentrated solution, stirred for 1 hour, decompression-filtered, and then concentrated under reduced pressure. A concentrated residue was azeotroped by adding 30 L of methanol, and then a concentrated solution and 221 L of methanol were added to a reactor. After purging with nitrogen, 11.85 kg of palladium/carbon (10% water mixture) was added, and then stirred for 6 hours while hydrogen pressure was maintained at 15 bar. The reaction solution was filtered, and then concentrated under reduced pressure. An aqueous layer was isolated in twice by adding 80 L of isopropylether and 80 L of purified water to the concentrated solution. An organic layer was isolated after adding methylene chloride/isopropanol=5:1 (126 L) to the aqueous layer and then stirring in 5 times. The organic layer was dehydration-filtered with 50 kg of sodium sulfate to obtain 9.7 kg of a title compound.
[0091] 1 H NMR (400 MHz, CDCl 3 ) δ 6.41 (brs, 1H), 3.76 (m, 3H), 3.63 (m, 1H), 3.52 (m, 1H), 3.42 (m, 1H), 3.28 (m, 1H), 3.16 (m, 1H), 2.95 (m, 1H), 2.45 (brs, 1H), 1.17 (s, 9H)
Step 5: Preparation of (R)-3-(t-butoxymethyl)piperazine-2-one di-p-toluoyl-L-tartrate (Chemical Formula 3)
[0092] A solution that was prepared by dissolving 100.0 g of (R)-3-(t-butoxymethyl)piperazine-2-one to 500 mL of acetone, and then by dissolving 207.4 g of di-p-toluoyl-L-tartaric acid to 700 mL of acetone was slowly added to a reactor. The resulting reaction solution was stirred for 1 hour, and then resulting solid was filtered to obtain 251.4 g of a title compound.
[0093] 1 H NMR (400 MHz, DMSO) δ 8.03 (brs, 1H), 7.83 (d, 4H), 7.32 (d, 4H), 5.67 (s, 2H), 3.55-3.66 (m, 3H), 3.18-3.29 (m, 3H), 3.04 (m, 1H), 2.36 (s, 6H), 1.10 (s, 9H)<
Example 6
Preparation of (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl)butanoyl]-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 1) Hydrochloride
Step 1: Preparation of t-butyl(R)-4-[(R)-2-(t-butoxymethyl)-3-oxopiperazine-1-yl]-4-oxo-1-(2,4,5-trifluorophenyl)butane-2-ylcarbamate
[0094] 1.0 g of (R)-3-t-butoxycarbonylamino-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2) was dissolved in 15 mL of methylene chloride, and then the resulting reaction solution was cooled to 0° C. While the reaction solution was stirred, 0.43 mL of 4-methylmorpholine was dropped; after 10 minutes, 0.47 mL of isobutylchloroformate was dropped; and then stirred for 1 hour. The resulting solid was filtered with diatomite; was washed with 5 mL of methylene chloride; and then the filtrate was cooled to 0° C. A solution that was prepared by dissolving 838 mg of (R)-(3-t-butoxymethyl)piperazine-2-one (Chemical Formula 3) to 3 mL of tetrahydrofuran and 1.1 mL of diisopropylethylamine were added to the cooled filtrate, and then stirred for 1 hour. Next, it was diluted with 20 ml of ethyl acetate; washed with brine in twice; and then an organic layer was dehydration-concentrated with magnesium sulfate. A residue was purified with column chromatography to obtain 838 mg of a title compound.
[0095] 1 H NMR (400 MHz, CDCl 3 ) δ 7.03 (m, 1H), 6.88 (m, 1H), 5.97 (m, 1H), 5.48 (m, 1H), 4.16-4.07 (m, 1H), 4.02-3.91 (m, 1H), 3.74 (m, 2H) 3.37 (m, 2H), 3.24 (m, 1H), 2.92 (m, 2H), 2.80 (m, 1H), 2.59 (m, 2H), 1.34 (d, 9H), 1.13 (s, 9H)
Step 2: Preparation of (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl)butanoyl]-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 1) Hydrochloride
[0096] 97 mg of t-butyl(R)-4-[(R)-2-(t-butoxymethyl)-3-oxopiperazine-1-yl]-4-oxo-1-(2,4,5-trifluorophenyl)butane-2-ylcarbamate of the above Step 1 was dissolved in 3 mL of methanol, 2 mL of 2N-hydrochloric acid/diethyl ether was added, and then stirred for 3 hours at room temperature. The resulting reaction mixture was concentrated and decompression-dried to obtain 64 mg of a title compound as a foaming solid.
[0097] 1 H NMR (400 MHz, CD 3 OD) δ 7.37 (m, 1H), 7.23 (m, 1H), 4.80 (m, 1H), 4.59-4.40 (m, 1H), 3.93 (m, 1H), 3.90-3.83 (m, 2H), 3.70 (m, 1H), 3.38 (m, 2H), 3.27 (m, 1H), 3.07 (m, 2H), 2.89-2.66 (m, 2H), 1.18 (s, 3H), 1.11 (s, 6H)
[0098] Mass (M+1): 402
Example 7
Preparation of (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl)butanoyl]-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 1)
Step 1: Preparation of benzyl(R)-4-[(R)-2-(t-butoxymethyl)-3-oxopiperazine-1-yl]-4-oxo-1-(2,4,5-trifluorophenyl)butane-2-ylcarbamate
[0099] 65.7 g of a title compound was obtained by using the same method with that of Step 1 of Example 6, except that 50.0 g of (R)-3-(benzyloxycarbonylamino)-4-(2,4,5-trifluorophenyl)butanoic acid and 85.7 g of (R)-(3-t-butoxymethyl)piperazine-2-one di-p-toluoyl-L-tartarate were used instead of (R)-3-t-butoxycarbonylamino-4-(2,4,5-trifluorophenyl)butanoic acid and (R)-(3-t-butoxylmethyl)piperazine-2-one, respectively, in Step 1 of Example 6.
[0100] 1 H NMR (400 MHz, CDCl 3 ) δ 7.20˜7.38 (m, 5H), 7.04 (m, 1H), 6.86 (m, 1H), 6.74 and 6.61 (br s, 1H), 5.79 (m, 1H), 5.00 (m, 2H), 4.91 and 4.69 (m, 1H), 4.41 and 4.25 (m, 1H), 4.16 and 3.99 (m, 1H), 3.68-3.90 (m, 3H), 3.21-3.38 (m, 2H), 2.96-3.12 (m, 2H), 2.59-2.90 (m, 2H), 1.45 and 1.11 (s, 9H)
Step 2: Preparation of (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl) butanoyl]-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 1)
[0101] 65.7 g of benzyl(R)-4-[(R)-2-(t-butoxymethyl)-3-oxopiperazine-1-yl]-4-oxo-1-(2,4,5-trifluorophenyl)butane-2-ylcarbamate of the above Step 1 was dissolved in 409 mL of methanol; a solution in which 13.1 g of palladium/carbon was wetted with 92 ml of ethyl acetate was added; and then stirred for 2 hours under hydrogen pressure of 15 bar. The resulting reaction solution was filtered with diatomite, and then concentrated under reduced pressure to obtain 34.8 g of a title compound.
[0102] 1 H NMR (400 MHz, CD 3 OD) δ 7.27 (m, 1H), 7.14 (m, 1H), 4.56-4.39 (m, 1H), 3.96-3.81 (m, 3H), 3.70 (m, 1H), 3.46 (m, 1H), 3.43-3.32 (m, 1H), 2.83-2.65 (m, 3H), 2.58-2.40 (m, 2H), 1.16 (s, 3H), 1.11 (s, 6H)
[0103] Mass (M+1): 402
Example 8
Preparation of (R)-4-[(R)-3-amino-4-(2,4,5-trifluoromethyl)butanoyl]-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 1) Tartrate
Step 1: Prepartion of (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl) butanoyl]-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 1)
[0104] 60 mg of hydrochloride compound represented by Chemical Formula 1 obtained from Example 6 was added to 10 mL of 5% sodium hydrogen carbonate aqueous solution; 10 mL of dichloromethane/2-propanol [4/1(v/v)] mixed solution was added; was extracted in twice to obtain an organic layer; and then the organic layer was decompression-dried to obtain 55 mg of a title compound as a solid.
[0105] 1 H NMR (400 MHz, CD 3 OD) δ 7.27 (m, 1H), 7.14 (m, 1H), 4.56-4.39 (m, 1H), 3.96-3.81 (m, 3H), 3.70 (m, 1H), 3.46 (m, 1H), 3.43-3.32 (m, 1H), 2.83-2.65 (m, 3H), 2.58-2.40 (m, 2H), 1.16 (s, 3H), 1.11 (s, 6H)
[0106] Mass (M+1): 402
Step 2: Preparation of (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl) butanoyl]-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 1) Tartrate
[0107] 55 mg of the compound of the above Step 1 or Example 7 was dissolved in 0.56 mL of acetone; the solution that was prepared by dissolving 26 mg of L-tartaric acid to 0.35 mL of ethanol/water [9/1(v/v)] was slowly added; and then stirred for 30 minutes. 0.56 mL of 2-propanol was again added thereto; stirred for 10 minutes; and then filtered to obtain 77 mg of a title compound as a solid.
[0108] 1 H NMR (400 MHz, CD 3 OD) δ 7.38 (m, 1H), 7.22 (m, 1H), 4.80 (m, 1H), 4.59-4.40 (m, 1H), 4.40 (s, 2H), 3.93 (m, 1H), 3.90-3.83 (m, 2H), 3.70 (m, 1H), 3.38 (m, 2H), 3.27 (m, 1H), 3.07 (m, 2H), 2.89-2.66 (m, 2H), 1.15 (s, 3H), 1.11 (s, 6H)
[0109] Mass (M+1): 402 | The present invention relates to an improved method for manufacturing dipeptidyl peptidase-IV inhibitor and intermediate. The present invention allows reduction of production costs by reacting low cost reagents, improves yield and is adaptable for mass production. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a plasma display panel driving circuit, as well as plasma display apparatus, used for wall-mounted television sets and large-screen monitors.
2. Related Art
An alternating-current surface discharge type plasma display panel (hereinafter called “PDP”) as a typical AC type is constituted by arranging a front plate containing a glass substrate formed by disposing a scan electrode and a sustain electrode which carry out surface discharge and a back plate containing a glass substrate formed by disposing data electrodes oppositely in parallel so that both electrodes set up a matrix and that a discharge space is formed in a gap, and by sealing the perimeter portion with sealing materials such as glass frit. Between both substrates of the front plate and the back plate, discharge cells divided by bulkheads area provided, and in a cell space between these bulkheads, a phosphor layer is formed. In the PDP of such configuration, ultraviolet rays are generated by gas discharge, and with these ultraviolet rays, phosphors of red (R), green (G), and blue (B) colors are excited to emit light, thereby achieving a color display.
In such plasma display apparatus, various techniques are proposed for saving the power consumption.
For example, a so-called electric power recovery circuit is proposed, that is, in consideration that the PDP is a capacitive load, an inductor is included in component elements of a resonance circuit, and the inductor and the capacity load of the PDP are resonated in LC, the electric power accumulated in the capacity load of the PDP is recovered in a capacitor for power recovery, and the recovered power is reused for driving the PDP (see, for example, patent document 1).
In this technique, the electric power recovered from the PDP can be reused in sustain pulse voltage to scanning electrode and sustain electrode in sustain period, and the power consumed in sustain period is saved, so that the power consumption can be reduced.
That is, in the sustain period generating circuit, a resonance circuit having an inductor, or an electric power recovery circuit is installed. The electric power accumulated in the capacitive load of the PDP (the capacitive load generated in the scanning electrode) is recovered, and the recovered electric power is reused as driving power of scanning electrode, and the power consumption is saved. In the sustain pulse generating circuit, a power recovery circuit is provided. Hence, the electric power accumulated in the capacitive load of the PDP (capacitive load generated in the sustain electrode) is recovered, and the recovered power is reused as driving power of sustain electrode, and the power consumption is saved.
The power recovery circuit recovers and supplies electric power by LC resonance between the capacity load of PDP and recovery inductor by using the recovery inductor of inductance element. When recovering the electric power, the electric power accumulated in the capacitive load generated in the scanning electrode is moved to the recovery capacitor by way of a counterflow preventive diode and a switching element. When supplying the electric power, the electric power accumulated in the recovery capacitor is supplied to the PDP by way of the counterflow preventive diode and switching element. Thus, the scanning electrode of PDP is driven in sustain period. Therefore, in the power recovery circuit, without supply of electric power from the power source in sustain period, the scanning electrode is driven by LC resonance, so that the power consumption is theoretically zero.
The above operation of recovery circuit is assumed without consideration of parasitic components of diode or wiring. To be precise, operation of recovery circuit is influenced by various parasitic components, such as parasitic capacity component parallel between drain terminal and source terminal of switching element, or anode terminal and cathode terminal of diode element, and parasitic inductance component in series to the pattern portion wiring between elements.
Effects of such parasitic components are serious problems when the diode element is switched from ON to OFF state. In recovery operation, the resonance current flows, but when the counterflow preventive diode is changed from ON to OFF, a reverse current due to parasitic capacity of diode flows (which is called recovery current).
By this recovery current, energy is accumulated in the recovery inductor, and when the counterflow preventive diode is completely turned off, the product of inductance value of recovery inductor and time change value of recovery current becomes a surge voltage, which is generated in the recovery inductor terminal.
This surge voltage is applied to the counterflow preventive diode, and the withstand voltage of the counterflow preventive diode is required to have a sufficient allowance more than the surge voltage as compared with the actual working voltage.
To solve this problem, it is proposed to use a protective diode element in the recovery circuit (see, for example, patent document 2). FIG. 14 shows its configuration. In the diagram, the recovery circuit includes recovery capacitor Cr, recovery switches Q 3 , Q 4 , counterflow preventive diodes D 3 , D 4 , recovery inductors L 1 , L 2 , and protective diodes D 105 , D 106 . Switching elements Q 1 , Q 2 constitute a sustain circuit for supplying sustain voltage Vsus. To simplify the explanation, in FIG. 14 , only the portion relating to recovery operation is described out of the configuration of scan circuit and sustain circuit. FIG. 14 is a circuit diagram for explaining the operation when the sustain circuit is grounded.
At the time of generating a surge voltage in the counterflow preventive diode D 3 , the protective diode D 105 conducts, and the energy accumulated in the inductor L 1 is consumed in the channel of inductor L 1 to protective diode D 105 to switching element Q 1 , and thereby generation of surge is suppressed.
Similarly at the time of generating a surge voltage in the counterflow preventive diode D 4 , the protective diode D 106 conducts, and the energy accumulated in the inductor L 2 is consumed in the channel of inductor L 2 to switching element Q 2 to protective diode D 106 , and thereby generation of surge is suppressed.
Patent document 1: Japanese Patent Publication No. 7-109542
Patent document 2: Japanese Patent No. 3369535
The above explanation refers to an operation not in consideration of parasitic inductance component of wiring. Actually, as shown in FIG. 14 , parasitic inductance components L 3 to L 6 present in the wiring between recovery switches Q 3 , Q 4 and counterflow preventive diodes D 3 , D 4 . In the conventional circuit, therefore, surge absorbing effect is not obtained in parasitic inductance components (L 3 to L 6 ).
Actually, due to effects of parasitic inductance components, a surge voltage is generated between terminals of counterflow preventive diode, and the required withstand voltage for counterflow preventive diode is raised. Elevation of withstand voltage between terminals leads to increase of semiconductor element loss of recovery circuit such as increase of forward voltage drop and decline of switching speed. To reduce the parasitic inductance, it is desired to increase the thickness and shorten the distance of wiring pattern.
In configuration of semiconductor elements, there are various limits from the aspects of substrate area, heat releasing efficiency of cooling plates for fixing semiconductor elements, and others, and it is practically next to impossible to design thick and short wiring pattern while satisfying these limits, and it has been difficult to keep the parasitic inductance always at low level.
In the prior art, as described herein, a higher withstand voltage is required in the semiconductor elements of recovery circuit when driving the PDP, and the loss of semiconductor elements is increased, and hence the recovery efficiency drops. Moreover, since the loss of semiconductor elements is increased, a plurality of semiconductor elements must be connected in parallel, which causes to increase the cost and increase the mounting area.
The invention is devised in the light of these problems, and it is hence an object thereof to present a PDP driving circuit capable of reducing the mounting area and enhancing the recovery efficiency by lowering the withstand voltage of the counterflow preventive diodes and protective diodes in the power recovery circuit, and thereby curtaining the number of component elements, and a plasma display apparatus using the same.
SUMMARY OF THE INVENTION
A first aspect of the invention provides a driving circuit for driving a plasma display panel which is a capacitive load. The driving circuit includes a pulse generation unit for generating a specified pulse voltage and applying to the capacitive load, and a power recovery unit for recovering an electric power from the capacitive load by resonant operation with capacitive load, and supplying the recovered power to a capacitive load. The power recovery unit has a larger capacity than the capacitive load, and includes a recovery capacitor for accumulating the recovered power, a recovery inductor for resonating with the capacitive load, a recovery switch element for forming a channel of passing current accompanied by resonance of capacitive load and recovery inductor by connecting the recovery capacitor to the capacitive load and recovery inductor, a counterflow preventive diode for blocking the current flowing in the recovery switching element in reverse polarity direction, and a protective diode. The protective diode forms a closed current channel including recovery inductor and recovery switch element when the counterflow preventive diode element is changed from ON to OFF state.
A second aspect of the invention provides a plasma display apparatus. The plasma display apparatus includes a plasma display panel having a plurality of scan electrodes and sustain electrodes, and the specified driving circuit for driving the plasma display panel.
According to the invention, in the power recovery circuit, when the counterflow preventive diode element is switched from ON state to OFF state by the protective diode, a closed current channel including recovery inductor and recovery switch element is formed, and the voltage applied to the protective diode is reduced, and the withstand voltage of the protective diode can be lowered. As a result, loss of protective diode is decreased, the number of elements connected in parallel can be reduced, and the mounting area can be decreased.
Further, the invention also suppresses the surge voltage generated when the counterflow preventive diode is changed from ON state to OFF state, and the withstand voltage of counterflow preventive diode can be lowered, and normal bias voltage drop Vf of counterflow preventive diode is lowered, and the recovery rate of electric power accumulated in the capacitive load of plasma display panel is improved, and the power consumption can be saved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of PDP driving circuit configuration in an embodiment of the invention.
FIG. 2 is a perspective view of configuration of plasma display panel (PDP).
FIG. 3 is an electrode configuration of PDP.
FIG. 4 is a diagram of drive voltage waveform applied to each electrode of PDP.
FIG. 5 is a diagram of parasitic inductance of wiring in PDP driving circuit.
FIG. 6 is a comparative explanatory diagram of drive waveform and, voltage and current waveform of component elements of PDP driving circuit in an embodiment and PDP driving circuit in a prior art.
FIG. 7 is a comparative explanatory diagram of drive waveform and, voltage and current waveform of component elements of PDP driving circuit in an embodiment and PDP driving circuit in a prior art.
FIG. 8 is a comparative explanatory diagram of drive waveform and, voltage and current waveform of component elements of PDP driving circuit in an embodiment and PDP driving circuit in a prior art.
FIG. 9 is a diagram showing the relation of timing of control signal upon start and voltage of constant voltage power source V 1 in a prior art.
FIG. 10 is a diagram showing the relation of timing of control signal upon start and voltage of constant voltage power source V 1 in an embodiment.
FIG. 11 is a diagram showing other example of configuration of power recovery circuit.
FIG. 12 is a diagram showing another example of configuration of power recovery circuit.
FIG. 13 is a block diagram of configuration of plasma display apparatus incorporating a PDP driving circuit in an embodiment.
FIG. 14 is a block diagram of configuration of a PDP driving circuit in a prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the invention is described specifically below by referring to the accompanying drawings.
1. PDP Driving Circuit
FIG. 1 is a block diagram of PDP driving circuit in an embodiment of the invention. The PDP driving circuit shown in FIG. 1 is a circuit for applying a drive voltage to electrodes of a plasma display panel (PDP), and driving the PDP. Prior to specific description of configuration and operation of PDP driving circuit, the configuration and operation of PDP are explained below. In FIG. 1 , the PDP 10 is shown as a capacitive addition Cp.
1.1 Plasma Display Panel (PDP)
FIG. 2 is a perspective view that indicates a structure of plasma display panel (PDP) driven by the PDP driving circuit of the embodiment. On a glass front plate 20 which is a first substrate, a plurality of display electrodes are formed in a pair of stripe scan electrode 22 and stripe sustain electrode 23 . To cover the scan electrode 22 and sustain electrode 23 , a dielectric layer 24 is formed, and a protective layer 25 is formed on the dielectric layer 24 .
On a back plate 30 which is a second substrate, a plurality of stripe data electrodes 32 covered with a dielectric layer 33 are formed so as to make overhead crossing with scan electrodes 22 and sustain electrodes 23 . A plurality of bulkheads 34 are disposed parallel to the data electrodes 32 on the dielectric layer 33 , and a phosphor layer 35 is formed on the dielectric layer 33 between these bulkheads 34 . The data electrodes 32 are disposed at positions between adjacent bulkheads 34 .
The front plate 20 and back plate 30 are disposed facing each other across a microscopic discharge space so that the scan electrodes 22 and sustain electrodes 23 may be orthogonal to the data electrodes 32 , and the perimeter portion is sealed with a sealing material such as glass frit. The discharge space is packed with a mixed gas of, for example, neon (Ne) and xenon (Xe) as discharge gas. The discharge space is partitioned into a plurality of compartments by the bulkheads 34 , and phosphor layers 35 emitting light of each color of red (R), green (G), and blue (B) are sequentially disposed in each compartment. Discharge cells are formed at portions where scan electrodes 22 and sustain electrode 23 intersect with data electrodes 32 , and one pixel is composed of three adjacent discharge cells forming phosphor layers 35 emitting light of each color. A region forming the discharge cells composing the pixel is an image display region, and a surrounding area of image display region is a non-display region not displaying image such as glass frit region.
FIG. 3 shows an electrode configuration in the PDP 10 . In the row direction, n rows of scan electrodes SC 1 to SCn (scan electrodes 22 in FIG. 2 ) and n rows of sustain electrodes SU 1 to SUn (sustain electrodes 23 in FIG. 2 ) are arrayed alternately, and in the column direction, m columns of data electrodes D 1 to Dm (data electrodes 32 in FIG. 2 ) are arrayed. Discharge cells Ci,j including a pair of scan electrode SCi and sustain electrode SUi (i=1 to n), and one data electrode Dj (j=1 to m) are formed in the discharge space. The total number of discharge cells C is (m×n) pieces.
In the PDP 10 having such configuration, an ultraviolet ray is generated by gas discharge, and phosphors of each color of R, G, and B are excited by the ultraviolet ray, and light is emitted, thereby a color display is produced. The PDP 10 displays in gradation by dividing one field period into a plurality of subfields, combining subfields of colors and driving. Each subfield is composed of reset period, address period, and sustain period. To display image data, a signal waveforms that varies in accord with reset period, address period, and sustain period, respectively, is applied to each electrode.
1.1.1 Drive Voltage Waveform of PDP
FIG. 4 shows each drive voltage waveform to be applied to each electrode of the PDP 10 . As shown in FIG. 4 , each subfield has reset period, address period, and sustain period. Each subfield operates almost similarly except that the number of sustain pulses in the sustain period is different in order to vary the weight in light emission period, and the principle of operation is nearly the same in the subfields, and operation of only one subfield is explained below.
First, in the reset period, for example, a positive pulse voltage is applied to all scan electrodes SC 1 to SCn, and a necessary wall charge is accumulated on the protective layer 25 and phosphor layer 35 on the dielectric layer 24 covering the scan electrodes SC 1 to SCn and sustain electrodes SU 1 to SUn. In this reset period, priming (detonator for discharge=exciting particle) is generated in order to decrease discharge delay and generate address discharge stably.
Specifically, in first half of reset period, the data electrodes D 1 to Dm, and sustain electrodes SU 1 to SUn are held at 0 (V), and in scan electrodes SC 1 to SCn, a slant waveform voltage ascending slowly from voltage Vi 1 below discharge start voltage toward voltage V 12 exceeding discharge start voltage is applied to data electrodes D 1 to Dm. In the ascending process of slant waveform voltage, a first feeble reset discharge occurs between scan electrodes SC 1 to SCn and sustain electrodes SU 1 to SUn, and data electrodes D 1 to Dm. Negative wall voltages are accumulated in the upper parts of scan electrodes SC 1 to SCn, and positive wall voltages are accumulated in the upper parts of data electrodes D 1 to Dm and upper parts of sustain electrodes SU 1 to SUn. Herein, the wall voltages in the upper parts of electrodes refer to voltages generated by wall charges accumulated on the dielectric layer covering the electrodes.
In latter half of reset period, sustain electrodes SU 1 to SUn are held at positive voltage Ve, and in scan electrodes SC 1 to SCn, a slant waveform voltage descending slowly from voltage V 13 below discharge start voltage toward voltage V 14 exceeding discharge start voltage is applied to sustain electrodes SU 1 to SUn. In this process, a second feeble reset discharge occurs between scan electrodes SC 1 to SCn and sustain electrodes SU 1 to SUn, and data electrodes D 1 to Dm. Negative wall voltages in the upper parts of scan electrodes SC 1 to SCn, and positive wall voltages in the upper parts of sustain electrodes SU 1 to SUn are weakened, and the positive wall voltages in the upper parts of data electrodes D 1 to Dm are adjusted to values suited to address operation. As a result, reset operation is terminated (hereinafter, the drive voltage waveform applied to each electrode in the reset period is called the “reset waveform.”).
Consequently, in address period, scanning is performed by applying negative scanning pulses sequentially to all scan electrodes SC 1 to SCn. While scanning the scan electrodes SC 1 to Scn, positive write pulse voltages are applied to data electrodes D 1 to Dm on the basis of display data. Thus, address discharge occurs between scan electrodes SC 1 to SCn and data electrodes D 1 to Dm, and a wall charge is formed on the surface of protective layer 25 on the scan electrodes SC 1 to SCn.
Specifically, in address period, the scan electrodes SC 1 to SCn are once held at voltage Vscn. Next, in address operation of discharge cells Cp, 1 to Cp,m (p being an integer of 1 to n), scan pulse voltage Vad is applied to scan electrode SCp, and positive address pulse voltage Vd is applied to data electrode Dq (Dq being a data electrode selected on the basis of video signal out of D 1 to Dm) corresponding to video signal to be displayed on the p-th row of data electrodes D 1 to Dm. Thus, address discharge occurs at discharge cells Cp,q corresponding to the intersection of data electrode Dq provided with address pulse voltage and scan electrode SCp provided with scan pulse voltage. By this address discharge, positive voltages are accumulated in the upper part of scan electrode CSp of discharge cells Cp,q, and negative voltages are accumulated in the upper part of the sustain electrode SUp, and the address operation is terminated. Hereinafter, similar address operation is executed up to the discharge cells Cn,q on the n-th row, and the address operation is completed.
In successive sustain period, for a specific period, a sufficient voltage for sustaining discharge is applied between scan electrodes SC 1 to SCn and sustain electrodes SU 1 to SUn. As a result, a discharge plasma is generated between scan electrodes SC 1 to SCn and sustain electrodes SU 1 to SUn, and the phosphor layer is excited and illuminated for a specific period. At this time, in the discharge space not provided with address pulse voltage in address period, discharge does not occur, and the phosphor layer 35 is not excited or illuminated.
Specifically, in sustain period, the scan electrodes SC 1 to SCn are once returned to 0 (V), and then the sustain electrodes SU 1 to SUn are returned to 0 (V) Consequently, positive sustain pulse voltage Vsus is applied to scan electrodes SC 1 to SCn. At this time, the voltage between upper part of scan electrode SCp and upper part of sustain electrode SUp in the discharge cells Cp,q causing address discharge is provided with wall voltages accumulated in the upper part of scan electrode SCp and upper part of sustain electrode SUp in address period, in addition to positive sustain pulse voltage Vsus, and hence becomes larger than discharge start voltage, and a first sustain discharge is generated. In the discharge cells Cp,q causing sustain discharge, negative voltages are accumulated in the upper part of scan electrode SCp so as to cancel the potential difference of scan electrode SCp and sustain electrode SUp upon generation of sustain discharge, while positive voltages are accumulated in the upper part of sustain electrode SUp. In this way, the first sustain discharge is terminated. After first sustain discharge, scan electrodes SC 1 to SCn are once returned to 0 (V), and then Vsus is applied to sustain electrodes SU 1 to SUn. At this time, the voltage between upper part of scan electrode SCp and upper part of sustain electrode Sup in the discharge cells Cp,q causing first sustain discharge is provided with wall voltages accumulated in the upper part of scan electrode SCp and upper part of sustain electrode SUp in first sustain discharge, in addition to positive sustain pulse voltage Vsus, and hence becomes larger than discharge start voltage, and a second sustain discharge is generated. Similarly, thereafter, sustain pulses are alternately applied to scan electrodes SC 1 to SCn and sustain electrodes SU 1 to SUn, and sustain discharge is executed consecutively in the discharge cells Cp,q causing address discharge by the number of times of sustain pulse.
1.2 Scan Electrode Driving Circuit and Sustain Electrode Driving Circuit
Back to FIG. 1 , the PDP driving circuit in the embodiment is provided with scan electrode driving circuit 501 and sustain electrode driving circuit 6 .
1.2.1 Scan Electrode Driving Circuit
The scan electrode driving circuit 501 includes sustain pulse generating circuit 5101 , reset waveform generating circuit 52 , scan pulse generating circuit 53 , and separation switches S 9 , S 10 .
(Sustain Pulse Generating Circuit)
The sustain pulse generating circuit 5101 has constant voltage power source V 1 for issuing direct-current voltage Vsus, switching elements (sustain switches) Q 1 , Q 2 , and power recovery circuit 50 . The sustain switches Q 1 , Q 2 are composed of generally known elements for performing switching action such as MOSFET.
The power recovery circuit 50 has recovery inductors L 1 , L 2 , recovery capacitor Cr, switching elements (recovery switches) Q 3 , Q 4 , counterflow preventive diodes D 3 , D 4 , and protective diodes D 5 , D 6 . The sustain pulse generating circuit 5101 generates sustain pulses to be applied to scan electrodes SC 1 to SCn by on/off operation of switching elements Q 1 , Q 2 , Q 3 , Q 4 .
One end of recovery capacitor Cr is connected to the ground. Between other end of recovery capacitor Cr, and connection point of sustain switch Q 1 and sustain switch Q 2 , recovery capacitor Cr, counterflow preventive diode D 3 , recovery switch Q 3 , and recovery inductor L 1 are connected in series. Between other end of recovery capacitor Cr, and connection point of switching element Q 1 and switching element Q 2 , counterflow preventive diode D 4 , recovery switch Q 4 , and recovery inductor L 2 are connected in series. The anode of protective diode D 5 is connected to the connection point of counterflow preventive diode D 3 and recovery switch Q 3 , and its cathode is connected to the constant voltage power source V 1 . The cathode of protective diode D 6 is connected to the connection point of counterflow preventive diode D 4 and recovery switch Q 4 , and its anode is connected to the ground.
The power recovery circuit 50 uses recovery inductors L 1 , L 2 which are inductance elements, and recovers and reuses the electric power by LC resonance between capacity load of PDP (capacitive load generated in scan electrodes SC 1 to SCn in FIG. 3 ) and inductance of recovery inductor L 1 or L 2 .
The switching element Q 1 supplies electric power to scan electrodes SC 1 to SCn of the PDP 10 through switching elements S 9 and S 10 from the constant voltage power source V 1 , and clamps the scan electrodes SC 1 to SCn at voltage value Vsus. The switching element Q 2 clamps the scan electrodes SC 1 to SCn at grounding potential by way of switching elements S 9 and S 10 . By these operations, the scan electrodes SC 1 to SCn are driven.
(Reset Waveform Generating Circuit)
The reset waveform generating circuit 52 includes switching elements S 21 , S 22 composed of generally known elements for making switching action such as MOSFET, constant voltage power source V 2 of voltage value Vset of second power source higher than the potential of the constant voltage power source V 1 , and constant voltage power source V 3 of negative voltage value Vad of third power source. Electric power is supplied to scan electrodes SC 1 to SCn from the constant voltage power source V 2 through switching element S 21 , and electric power of negative potential is supplied to scan electrodes SC 1 to SCn from constant voltage power source V 3 through switching element S 22 , and thereby reset waveform is generated. The switching element S 21 is disposed in a direction of cutting off the current of the body diode flowing in the main discharge channel from the constant voltage power source V 2 , and the switching element 322 is disposed in a direction of cutting off the current of the body diode flowing from the main discharge channel X to the constant voltage power source V 3 .
The reset waveform generating circuit 52 generates, in first half of reset period, voltage V 12 exceeding discharge start voltage from voltage Vi 1 below discharge start voltage to data electrodes D 1 to Dm, that is, slant waveform ascending slowly toward Vset, and in second half of reset period, generates voltage V 14 exceeding discharge start voltage from voltage V 13 below discharge start voltage to sustain electrodes SU 1 to SUn, that is, slant voltage slowly descending toward Vad, and applied to scan electrodes SC 1 to SCn.
(Scan Pulse Generating Circuit)
The scan pulse generating circuit 53 includes switching elements S 31 , S 32 composed of generally known elements for making switching action such as MOSFET, constant voltage power source V 4 of voltage value Vscn, counterflow preventive diode D 31 for preventing flow of current into the constant voltage power source V 4 , capacitor C 31 , and scan IC (IC 31 ) for making switching action, and generates negative scan pulses in address period, and applies sequentially to scan electrodes SC 1 to SCn. The scan IC (IC 31 ) is a circuit for selecting among scan electrodes SC 1 to SCn for applying voltage for address discharge.
These switching elements S 1 , S 2 , S 5 , S 6 , S 21 , S 22 , S 31 , S 32 , and scan IC (IC 31 ) are changed over and controlled on the basis of subfield control signal generated in the subfield processing circuit 3 .
1.2.2 Sustain Electrode Driving Circuit
The sustain electrode driving circuit 6 includes constant voltage power source V 5 for issuing direct-current voltage Vsus, switching elements S 7 , S 8 composed of generally known elements for making switching action such as MOSFET, and power recovery circuit 50 b . The power recovery circuit 50 b has recovery inductors L 11 , L 12 , recovery capacitor Cr 2 , switching elements Q 31 , Q 41 , counterflow preventive diodes D 31 , D 41 , and protective diodes D 51 , D 61 . Operation of sustain electrode driving circuit 6 is same as that of sustain pulse generating circuit 5101 . The sustain electrode driving circuit 6 cooperates with the sustain pulse generating circuit 5101 , and applies a specified voltage to the PDP 10 .
1.2.3 Operation of Power Recovery Circuit
Operation of power recovery circuit 50 in the embodiment is explained while referring to FIG. 5 to FIG. 8 .
FIG. 5 is a circuit diagram adding actually existing parasitic inductance components L 3 to L 6 of wiring to the electric power circuit 50 in FIG. 1 . Parasitic inductance L 3 shows the sum of parasitic inductance of wiring between counterflow preventive diode D 3 and recovery switch Q 3 , and wiring between recovery switch Q 3 and protective diode D 5 . Parasitic inductance L 4 shows the parasitic inductance of wiring between recovery switch Q 3 and recovery inductor L 1 . Parasitic inductance L 5 shows the parasitic inductance of wiring between recovery inductor L 2 and recovery switch Q 4 . Parasitic inductance L 6 shows the sum of parasitic inductance of wiring between recovery switch Q 4 and counterflow preventive diode D 4 , and wiring between recovery switch Q 4 and protective diode D 6 .
FIG. 6 to FIG. 8 show drive waveform of sustain pulse generating circuit 5101 , and voltage waveform and current waveform of elements in power recovery circuit. FIG. 6 ( a ), FIG. 7 ( a ), and FIG. 8 ( a ) show waveforms corresponding to the conventional power recovery circuit shown in FIG. 12 , and FIG. 6 ( b ), FIG. 7 ( b ), and FIG. 8 ( b ) show waveforms corresponding to the power recovery circuit of the embodiment shown in FIG. 1 .
In FIG. 6 and FIG. 8 , the waveforms represent, sequentially from the top, gate signal of recovery switch Q 3 , gate signal of sustain switch Q 1 , gate signal of recovery switch Q 4 , gate signal of sustain switch Q 2 , voltage V_Cp of PDP 10 , sum iL of current (iL 1 ) flowing in recovery inductor L 1 and current (iL 2 ) flowing in recovery inductor L 2 , voltage across counterflow preventive diode D 3 (reverse bias is positive direction) V_D 3 , voltage across recovery switch Q 3 V_Q 3 , and current iLP flowing in parasitic inductors L 3 , L 4 (or L 5 , L 6 ).
In FIG. 7 ( a ), V_D 105 and V_D 106 respectively show waveforms of voltages across protective diodes D 105 and D 106 in the prior art (reverse bias is positive direction). In FIG. 7 ( b ), V_D 5 and V_D 6 are respectively voltages across protective diodes D 5 and D 6 (reverse bias is positive direction).
Operation of power recovery circuit 50 in the embodiment in the modes of period T 1 to T 4 is explained below in comparison with the prior art.
<Mode 1>: Period from T 1 to T 2
Voltage V_Cp of PDP 10 is zero, the sustain switch Q 2 is on, and is turned off at timing T 1 , and the recovery switch Q 3 is turned on. As a result, capacity Cp of PDP 10 is charged from the recovery capacitor Cr in the channel of diode D 3 to parasitic inductor L 3 to recovery switch Q 3 to parasitic inductor L 4 and to recovery inductor L 1 . This flowing resonance current iL is inverted after a certain peak and becomes zero, and mode 1 is terminated at this timing (T 2 ).
In this period, the voltage across terminals V_D 106 of the conventional protective diode D 106 is applied up to Vsus as shown in FIG. 8 ( a ), whereas the voltage across terminals V_D 6 of the protective diode D 6 of the embodiment is applied only to Vsus/2 as shown in FIG. 8 ( b ). This is because the connection point of the conventional protective diode D 106 is the terminal of recovery inductor L 2 , whereas the connection point of the protective diode D 6 of the invention is connected to the connection point of recovery switch Q 4 and counterflow preventive diode D 4 .
That is, in this mode, the connection point potential of recovery inductor L 2 and protective diode D 106 in the prior art is Vsus, but the connection point potential of protective diode D 6 of the embodiment is Vsus/2, lower by the portion of Vsus/2 of the voltage across terminals of recovery switch D 4 than Vsus.
Therefore, the withstand voltage of the protective diode D 6 of the embodiment can be reduced to half of the conventional protective diode D 106 . It is hence possible to use a protective diode element having a lower forward voltage drop Vf, and heat loss occurring in protective diode can be reduced. Besides, the cost of the protective diode element is lowered. When a plurality of diodes are connected in parallel, since the number of pieces of parallel connection can be decreased, and the substrate mounting area is smaller, the manufacturing cost can be reduced.
<Mode 2>: Period from T 2 to T 3
Voltage V_Cp of PDP 10 is charged nearly to Vsus, and the sustain switch Q 1 is off, and is turned on at the timing T 2 . At this timing, voltage V_Cp of PDP 10 is fixed at Vsus, but resonance current iL inverted at point T 2 charges the parasitic capacity (not shown) of the counterflow preventive diode D 3 , and turns off the counterflow preventive diode D 3 .
At this time, in the voltage waveform V_D 3 across both ends of conventional counterflow preventive diode D 3 , a surge voltage (see broken line region A in FIG. 7 ( a )) is generated. By contrast, in the voltage waveform V_D 3 across both ends of the counterflow preventive diode D 3 of the power recovery circuit 50 of the embodiment, surge voltage is suppressed (see broken line region A in FIG. 7 ( b )). The reason is as follows why the surge voltage is suppressed.
When the voltage of parasitic capacity of counterflow preventive diode D 3 is charged up to Vsus/2, the protective diode D 5 is in forward bias and conducts, and a loop channel is formed in the sequence of recovery inductor L 1 to parasitic inductor L 4 to recovery switch Q 3 to parasitic inductor L 3 to protective diode D 5 to sustain switch Q 1 to recovery inductor L 1 . Inverting this loop channel, the resonance current iL returns, and the energy accumulated in inductors L 1 , L 3 , L 4 is consumed in the loop channel. As a result, the change (di/dt) of current iLP flowing in parasitic inductors L 3 , L 4 is smaller than in the prior art (see broken line region B in FIG. 7 ), and thereby generation of surge voltage is suppressed.
<Mode 3>: Period from T 3 to T 4
Voltage V_Cp of PDP 10 is Vsus, and the sustain switch Q 1 is on, and is turned off at the timing T 3 , and the recovery switch Q 4 is turned on. From capacitive load Cp of PDP 10 , an electric charge is regenerated in recovery capacitor Cr by way of recovery inductor L 2 to parasitic inductor L 5 to recovery switch Q 4 to parasitic inductor L 6 to counterflow preventive diode D 4 . The resonance current iL flowing at this time is inverted at a certain peak, and is inverted again to become zero, and mode 3 is terminated at this timing (T 4 ).
In this period, the voltage across terminals V_D 105 of the conventional protective diode D 105 is applied up to Vsus as shown in FIG. 8 ( a ), whereas the voltage across terminals V_D 5 of the protective diode D 5 of the embodiment is applied only to Vsus/2 as shown in FIG. 8 ( b ). This is because the connection point of the conventional protective diode D 105 is the terminal of recovery inductor L 1 , whereas the connection point of the protective diode D 5 of the invention is connected to the connection point of recovery switch Q 3 and counterflow preventive diode D 3 .
That is, in this mode, the connection point potential of recovery inductor L 1 and protective diode D 105 in the prior art is Vsus, but the connection point potential of protective diode D 5 of the embodiment is Vsus/2, lower by the portion of Vsus/2 of the voltage across terminals of recovery switch D 3 than Vsus.
Therefore, the withstand voltage of the protective diode D 5 can be reduced to half of the conventional protective diode D 105 . It is hence possible to use a protective diode element having a lower forward voltage drop Vf, and heat loss occurring in protective diode can be reduced. Besides, the cost of the protective diode element is lowered. When a plurality of diodes are connected in parallel, since the number of pieces of parallel connection can be decreased, and the substrate mounting area is smaller, the manufacturing cost can be reduced.
<Mode 4>: Period from T 4 to Next T 1
Voltage V_Cp of PDP 10 is discharged nearly to zero (GOD potential), and the sustain switch Q 2 is off, and is turned on at the timing T 4 . At this timing, voltage V_Cp of PDP 10 is fixed at zero (GND potential), but resonance current iL inverted at point T 4 charges the parasitic capacity (not shown) of the counterflow preventive diode D 4 , and turns off the counterflow preventive diode D 4 .
At this time, as shown in broken line region A in FIG. 8 , in the terminal voltage waveform V_D 4 of the conventional counterflow preventive diode D 4 , a surge voltage is generated, but in the terminal voltage waveform V_D 4 of the counterflow preventive diode D 4 of the embodiment, a surge voltage is suppressed.
The reason is as follows: when the voltage of parasitic capacity of counterflow preventive diode D 4 is charged up to Vsus/2, the protective diode D 6 is in forward bias, and a loop channel is formed in the sequence of recovery inductor L 2 to sustain switch Q 2 to protective diode D 6 to parasitic inductor L 6 to recovery switch Q 4 to parasitic inductor L 5 to recovery inductor L 2 . Inverting this loop channel, the resonance current iL returns, and the energy accumulated in inductors L 2 , L 5 , L 6 is consumed in the loop channel. As a result, the change (di/dt) of current iLP flowing in parasitic inductors L 6 , L 5 is smaller than in the prior art (see broken line region B in FIG. 8 ), and thereby generation of surge voltage is suppressed.
In the embodiment, as described herein, the withstand voltage of protective diodes D 5 , D 6 of the PDP driving circuit can be reduced to half. Further, since the surge voltage of the counterflow preventive diodes D 3 , D 4 can be suppressed, the withstand voltage may be much lower than in the prior art.
In the above explanation, the recovery capacitor Cr is assumed to be charged to about Vsus/2, but it is possible to charge by other method, for example, a method of establishing a circuit and a period for charging the recovery capacitor Cr, in a period before start of recovery operation.
Besides, if any extra charging circuit is not provided, when charging by the regenerative power from the PDP 10 , the recovery capacitor Cr can be changed up to Vsus/2 by starting recovery operation while gradually elevating the Vsus voltage (for example, elevating gradually from about Vsus/2).
The reason why the start mode is necessary is as follows: the withstand voltage of protective diode depends on the differential portion of Vsus of supply voltage and voltage across terminals of recovery switch, and usually withstand voltage of Vsus/2 is enough, but when the supply voltage is Vsus or when the voltage across terminals of recovery switch is nearly zero, the withstand voltage decreasing effect of protective diode is not obtained. In other words, the starting method is not particularly specified as far as the start mode is controlled so that the difference of supply voltage and voltage across terminals of recovery switch may be Vsus/2 or less.
The start mode of the embodiment is more specifically described below.
First, the conventional start mode is explained. FIG. 9 is a diagram explaining the relation of control signal timing and voltage of constant voltage power source V 1 upon start of PDP driving circuit. In the diagram, solid line X denotes the output voltage of constant voltage power source V 1 and solid line Y represents the voltage of recovery capacitor Cr.
As shown in FIG. 9 , the output of constant voltage power source V 1 gradually climbs up after start and reaches specified voltage (Vsus). In the prior art, a drive signal of sustain pulse generating circuit was applied at a later timing (t 1 ) than the timing (t 2 ) of the output of constant voltage power source V 1 reaching the specified voltage (Vsus). In initial state, the voltage of recovery capacitor Cr is zero, but by the subsequent on/off operation of switching elements Q 1 to Q 4 , the recovery capacitor Cr is charged to Vsus/2. At this time, from the moment of output of constant power source V 1 reaching specified voltage (Vsus) (t 2 ), till the moment of voltage of recovery capacitor Cr reaching Vsus/2 (t 4 ), voltage Vsus is applied between both ends of protective diode. This causes a problem in that withstand voltage of protective diode cannot be lowered.
This problem can be solved by the following starting operation.
FIG. 10 is a diagram explaining the relation of control signal timing and voltage of constant voltage power source V 1 upon start of PDP driving circuit of the embodiment.
As stated above, when the PDP driving circuit is started (the power is turned on), the output of constant voltage power source V 1 climbs up gradually and reaches specified voltage (Vsus). At this time, in the embodiment, before the output of constant voltage power source V 1 reaches Vsus/2, that is, at timing (t 1 ) before the output of constant voltage power source V 1 reaches Vsus/2 (t 3 ), driving signal of sustain pulse generating circuit 5101 is applied.
When the driving signal of sustain pulse generating circuit 5101 is applied, the switching elements Q 1 to Q 4 start on/off operation at specified timing.
In initial state, since the voltage of recovery capacitor Cr is zero, if the switching element Q 3 is turned on, the capacitive load Cp of PDP 10 will not be charged. At the turn-on timing of switching element Q 1 , a potential equal to the voltage of constant voltage power source V 1 is supplied to the capacity load Cp. Then, after turning off the switching elements Q 1 , Q 2 , the switching element Q 4 is turned on. At this time, the voltage accumulated in the capacitive load Cp of PDP 10 is regenerated into the recovery capacitor Cr. This regenerative voltage is determined by the ratio of capacity of capacitive load Cp of PDP and capacity of recovery capacitor Cp. Generally, the capacity of recovery capacitor Cr is about 10 to 30 times of capacity of PDP, and by repeating the turn-on operation of switching element Q 4 by 10 to 30 times, about half voltage (Vsus/2) of voltage of constant voltage power source V 1 can be accumulated in the recovery capacitor Cr.
The rise time of constant voltage power source V 1 depends on the output power capacity of power source circuit and capacity of electrolytic capacitor connected to the constant voltage power source V 1 , but generally 500 msec to 1 sec or more is needed. By contrast, the turn-on period of switching element Q 4 is about 5 μsec, and if this recovery operation is repeated 30 times, charging operation of recovery capacitor Cr is completed only in about 200 μsec, and about half voltage (Vsus/2) of constant voltage power source V 1 can be charged in the recovery capacitor Cr.
By this starting operation, before the output of the constant voltage power source V 1 reaches the voltage Vsus, the voltage of recovery capacitor Cr reaches Vsus/2. Hence voltage larger than Vsus/2 is not applied between both ends of protective diode. That is, as the difference of voltage of constant voltage power source V 1 and voltage of recovery capacitor Cr is always held below Vsus/2 whether upon start or in stationary operation, the withstand voltage of protective diode can be lowered.
1.3 Modified Examples
Other example of power recovery circuit is shown in shown in FIG. 11 . In the power recovery circuit 50 shown in FIG. 11 , the recovery inductances L 1 and L 2 shown in FIG. 1 are formed by one recovery inductance L 7 . This configuration is possible only in the condition that the period of mode 1 and period of mode 3 are identical. In the power recovery circuit 50 shown in FIG. 1 , supposing the resonance current iL flowing in recovery conductor L 1 or L 2 to be corresponding to resonance current flowing in recovery inductance L 7 in power recovery circuit 55 , the operation can be explained same as in the power recovery circuit 50 shown in FIG. 1 .
In this configuration, too, same as in FIG. 1 , parasitic inductances L 3 to L 6 are present in the wiring of power recovery circuit 50 , and the halving effect of withstand voltage of protective diodes D 5 , D 6 and suppressing effect of surge voltage of counterflow preventive diodes D 3 , D 4 can be obtained.
Switching elements Q 1 , Q 2 , Q 3 , Q 4 may be generally known elements for making switching action such as MOSFET. In this case, body diodes are generated in reverse parallel to the switching action portions, and if the switching action is in cut-off state, a forward current for body diodes can be passed. Switching elements Q 1 , Q 2 , Q 3 , Q 4 may be also composed of generally known insulating gate type bipolar transistors (IGBTs) having features of low loss and easy control in high voltage operation. It is considered that a large current of hundreds of amperes flows when driving the PDP 10 . Since parasitic diodes are not generated in the IGBT, if the switching elements Q 1 and Q 2 are IGBTs, diodes corresponding to body diodes parasitically generated in the MOSFET are connected in reverse parallel to the switching elements Q 1 , Q 2 .
In the embodiment, types of switching elements are not particularly limited, and the switching elements Q 1 , Q 2 may be composed of IGBTs, and switching elements Q 3 , Q 4 may be composed of MOSFETs, or may be composed of other generally known elements making switching action.
In the power recovery circuit 50 shown in FIG. 1 , the position of recovery inductors L 1 , L 2 may be replaced by the position of recovery switches Q 3 , Q 4 (see FIG. 12 ). In this case, the anode of protective diode D 5 is connected to the connection point of counterflow preventive diode D 3 and recovery inductor L 1 , and the cathode of protective diode D 6 is connected to the connection point of counterflow preventive diode D 4 and recovery inductor L 2 .
1.4 Summary
According to the embodiment, in the power recovery circuit of sustain pulse generating circuit 5101 , by connecting the protective diode between the recovery switch and counterflow preventive diode, the withstand voltage of protective diode can be reduced to half. Therefore, loss of protective diode can be decreased, and the number of elements connected in parallel can be reduced. Moreover, since the withstand voltage of counterflow preventive diode can be reduced, and Vf of counterflow preventive diode can be decreased, adn the recovery rate of electric power accumulated in the capacitive load of PDP 10 is improved, and the power consumption can saved.
2. Plasma Display Apparatus
FIG. 13 is a block diagram of configuration of plasma display apparatus incorporating the PDP driving circuit of the embodiment.
The plasma display apparatus shown in FIG. 13 includes AD converter 1 , video signal processing circuit 2 , subfield processing circuit 3 , data electrode driving circuit 4 , scan electrode driving circuit 5 , sustain electrode driving circuit 6 , and PDP 10 .
The AD converter 1 converts an input analog video signal into a digital video signal. The video signal processing circuit 2 converts from video signal of one field into subfield data for controlling each subfield, in order to emit light and display in the PDP 10 by combination of plural subfields different in weight in light emission period from the input digital video signal.
The subfield processing circuit 3 generates control signal for data electrode driving circuit, control signal for scan electrode driving circuit, and control signal for sustain electrode driving circuit, from the subfield data generated in the video signal processing circuit 2 , and issues respectively to the data electrode driving circuit 4 , scan electrode driving circuit 5 , and sustain electrode driving circuit 6 .
The PDP 10 , as described above, is composed of n rows of scan electrodes SC 1 to SCn (scan electrodes 22 in FIG. 2 ) and n rows of sustain electrodes SU 1 to SUn (sustain electrodes 23 in FIG. 2 ) arrayed alternately in the row direction, and m columns of data electrodes D 1 to Dm (data electrodes 32 in FIG. 2 ) arrayed in the column direction. Discharge cells Ci,j including a pair of scan electrode SCi and sustain electrode SUi (i=1 to n) and one data electrode Dj (j=1 to m) are formed by (m×n) pieces in discharge space, and one pixel is composed of three discharge cells emitting light in red, green and blue colors.
The data electrode driving circuit 4 drives data electrodes Dj independently on the basis of the control signal for data electrode driving circuit.
The scan electrode driving circuit 501 incorporates a sustain pulse generating circuit 5101 for generating sustain pulses to be applied to scan electrodes SC 1 to SCn in sustain period, and can independently drive the scan electrodes SC 1 to SCn. The scan electrode driving circuit 501 independently drives the scan electrodes SC 1 to SCn on the basis of the control signal for driving the scan electrodes.
The sustain electrode driving circuit 6 incorporates a sustain pulse generating circuit 61 for generating sustain pulses to sustain electrodes SU 1 to SUn in sustain period, and can drive all of sustain electrodes SU 1 to SUn in the PDP 10 in batch. The sustain electrode driving circuit 6 drives the sustain electrodes SU 1 to SUn on the basis of control signal for driving the sustain electrodes.
INDUSTRIAL APPLICABILITY
The invention relates to PDP driving circuit having power recovery circuit and plasma display apparatus, and is particularly useful for PDP driving circuit and plasma display apparatus capable of reducing withstand voltage of diode elements in recovery circuit. | A PDP driving circuit is comprised of a power recovery unit for recovering an electric power from a capacitive load by resonance operation with PDP which is the capacitive load Cp, and reusing the recovered power. The power recovery unit includes a recovery inductor for resonating with the capacitive load, a recovery switch element for connecting the recovery capacitor to the capacitive load and recovery inductor, and forming a channel for passing resonance current, a counterflow preventive diode for blocking flow of current in the recovery switch element in reverse polarity direction, and a protective diode for forming a closed current channel including the recovery inductor and recovery switch element when the counterflow preventive diode is changed from ON state to OFF state. | 6 |
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to a novel mesomorphic compound, a liquid crystal composition containing the compound and liquid crystal device using the composition, and more particularly to a novel liquid crystal composition with improved responsiveness to an electric field and a liquid crystal device using the liquid crystal composition for use in a liquid crystal display apparatus, a liquid crystal-optical shutter, etc.
Hitherto, liquid crystal devices have been used as an electro-optical device in various fields. Most liquid crystal devices which have been put into practice use TN (twisted nematic) type liquid crystals, as shown in "Voltage-Dependent Optical Activity of a Twisted Nematic Liquid Crystal" by M. Schadt and W. Helfrich "Applied Physics Letters" Vol. 18, No. 4 (Feb. 15, 1971) pp. 127-128.
These devices are based on the dielectric alignment effect of a liquid crystal and utilize an effect that the average molecular axis direction is directed to a specific direction in response to an applied electric field because of the dielectric anisotropy of liquid crystal molecules. It is said that the limit of response speed is on the order of milli-seconds, which is too slow for many uses. On the other hand, a simple matrix system of driving is most promising for application to a large-area flat display in view of cost, productivity, etc., in combination. In the simple matrix system, an electrode arrangement wherein scanning electrodes and signal electrodes are arranged in a matrix, and for driving, a multiplex driving scheme is adopted wherein an address signal is sequentially, periodically and selectively applied to the scanning electrodes and prescribed data signals are selectively applied in parallel to the signal electrodes in synchronism with the address signal.
When the above-mentioned TN-type liquid crystal is used in a device of such a driving system, a certain electric field is applied to regions where a scanning electrode is selected and signal electrodes are not selected or regions where a scanning electrode is not selected and a signal electrode is selected (which regions are so called "half-selected points"). If the difference between a voltage applied to the selected points and a voltage applied to the half-selected points is sufficiently large, and a voltage threshold level required for allowing liquid crystal molecules to be aligned or oriented perpendicular to an electric field is set to a value therebetween, display devices normally operate. However, in fact, as the number (N) of scanning lines increases, a time (duty ratio) during which an effective electric field is applied to one selected point when a whole image area (corresponding to one frame) is scanned decreases with a ratio of 1/N. Accordingly, the larger the number of scanning lines are, the smaller is the voltage difference of an effective value applied to a selected point and non-selected points when scanning is repeatedly effected. As a result, this leads to unavoidable drawbacks of lowering of image contrast or occurrence of interference or crosstalk. These phenomena are regarded as essentially unavoidable problems appearing when a liquid crystal having no bistability (i.e. liquid crystal molecules are horizontally oriented with respect to the electrode surface as stable state and are vertically oriented with respect to the electrode surface only when an electric field is effectively applied) is driven (i.e. repeatedly scanned) by making use of a time storage effect. To overcome these drawbacks, the voltage averaging method, the two-frequency driving method, the multiple matrix method, etc. has been already proposed. However, any method is not sufficient to overcome the above-mentioned drawbacks. As a result, it is the present state that the development of large image area or high packaging density with respect to display elements is delayed because it is difficult to sufficiently increase the number of scanning lines.
To overcome drawbacks with such prior art liquid crystal devices, the use of liquid crystal devices having bistability has been proposed by Clark and Lagerwall (e.g. Japanese Laid-Open Patent Appln. No. 56-107216, U.S. Pat. No. 4,367,924, etc.). In this instance, as the liquid crystals having bistability, ferroelectric liquid crystals having chiral smectic C-phase (SmC*) or H-phase (SmH*) are generally used. These liquid crystals have bistable states of first and second optically stable states with respect to an electric field applied thereto. Accordingly, as different from optical modulation devices in which the above-mentioned TN-type liquid crystals are used, the bistable liquid crystal molecules are oriented to first and second optically stable states with respect to one and the other electric field vectors, respectively. Further, this type of liquid crystal has a property (bistability) of assuming either one of the two stable states in response to an applied electric field and retaining the resultant state in the absence of an electric field.
In addition to the above-described characteristic of showing bistability, such a ferroelectric liquid crystal (hereinafter sometimes abbreviated as "FLC") has an excellent property, i.e., a high-speed responsiveness. This is because the spontaneous polarization of the ferroelectric liquid crystal and an applied electric field directly interact with each other to induce transition of orientation states. The resultant response speed is faster than the response speed due to the interaction between dielectric anisotropy and an electric field by 3 to 4 digits.
Thus, a ferroelectric liquid crystal potentially has very excellent characteristics, and by making use of these properties, it is possible to provide essential improvements to many of the above-mentioned problems with the conventional TN-type devices. Particularly, the application to a high-speed optical shutter and a display of a high density and a large picture is expected. For this reason, there has been made extensive research with respect to liquid crystal materials showing ferroelectricity. However, ferroelectric liquid crystal materials developed heretofore cannot be said to satisfy sufficient characteristics required for a liquid crystal device including low-temperature operation characteristic, high-speed responsiveness, etc. Among a response time τ, the magnitude of spontaneous polarization Ps and viscosity η, the following relationship exists: τ=η/(Ps·E), where E is an applied voltage. Accordingly, a high response speed can be obtained by (a) increasing the spontaneous polarization Ps, (b) lowering the viscosity η, or (c) increasing the applied voltage E. However, the driving voltage has a certain upper limit in view of driving with IC, etc., and should desirably be as low as possible. Accordingly, it is actually necessary to lower the viscosity or increase the spontaneous polarization.
A ferroelectric chiral smectic liquid crystal having a large spontaneous polarization generally provides a large internal electric field in a cell given by the spontaneous polarization and is liable to pose many constraints on the device construction giving bistability. Further, an excessively large spontaneous polarization is liable to accompany an increase in viscosity, so that remarkable increase in response speed may not be attained as a result.
Further, if it is assumed that the operation temperature of an actual display device is 5°-40 ° C., the response speed changes by a factor of about 20, so that it actually exceeds the range controllable by driving voltage and frequency.
As described hereinabove, commercialization of a ferroelectric liquid crystal device requires a ferroelectric chiral smectic liquid crystal composition having a low viscosity, a high-speed responsiveness and a small temperature-dependence of response speed.
In a representative FLC cell structure, a pair of substrates are disposed, each substrate of e.g. glass being provided with an electrode pattern of e.g. ITO, further thereon with a layer of e.g. SiO 2 (about 1000 Å) for preventing short circuit between the pair of substrates and further thereon with a film of e.g. polyimide (PI; such as SP-510, 710, . . . available from Toray K.K.) of about 400 Å in thickness, which is then treated for alignment control by rubbing with e.g. an acetate fiber-planted cloth. Such a pair of substrates are disposed opposite to each other so that their alignment control directions are symmetrical and the spacing between the substrates is held at 1-3 microns.
On the other hand, it is known that the ferroelectric liquid crystal molecules under such non-helical conditions are disposed in succession so that their directors (longer molecular axes) are gradually twisted between the substrates and do not show a uniaxial orientation or alignment (i.e., in a splay alignment state). A problem in this case is a low transmittance through the liquid crystal layer.
Transmitted light intensity I through a liquid crystal is given by the following equation with respect to the incident light intensity I 0 under cross nicols when the uniaxial alignment of the molecules is assumed:
I=I.sub.0 sin.sup.2 (4θa) sin.sup.2 (πnd/λ)(1),
wherein Δn denotes the refractive index anisotropy of the FLC; d, the cell thickness; λ, the wavelength of the incident light; and θa, a half of the angle between two stable states (tilt angle).
When a conventional FLC cell is used, it has been experimentally known that θa is 5-8 degrees under a twisted alignment condition. The control of physical properties affecting the term Δndπ/λ cannot be easily performed, so that it is desired to increase θa to increase I. However, this has not been successfully accomplished by only a static alignment technique.
With respect to such a problem, it has been proposed to utilize a torque relating to a dielectric anisotropy Δε of an FLC (1983 SID report from AT & T; Japanese Laid-Open Patent Applns. 245142/1986, 246722/1986, 246723/1986, 246724/1986, 249024/1986 and 249025/1986). More specifically, a liquid crystal molecule having a negative Δε tends to become parallel to the substrates under application of an electric field. By utilizing this property, if an effective value of AC electric field is applied even in a period other than switching, the above-mentioned twisted alignment is removed, so that θa is increased to provide an increased transmittance (AC stabilization effect).
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel mesomorphic compound, a liquid crystal composition with improved responsiveness containing the mesomorphic compound for providing a practical ferroelectric liquid crystal device, and a liquid crystal device using the liquid crystal composition.
Another object of the present invention is to provide a liquid crystal device using a liquid crystal composition containing a novel mesomorphic compound and showing improved display characteristics due to AC stabilization effect.
According to the present invention, there is provided a mesomorphic compound represented by the following formula (I): ##STR4## wherein R 1 and R 2 respectively denote an alkyl group having 1-16 carbon atoms capable of having a substituent; X 1 , X 2 and X 3 respectively denote a single bond, --O--, ##STR5## A 1 and A 2 respectively denote ##STR6## wherein X 4 and X 5 respectively denote hydrogen, fluorine, chlorine, bromine, --CH 3 , --CN or --CF 3 with proviso that X 1 always denotes a single bond when A 1 denotes a single bond; and n is 0 or 1.
According to the present invention, there is further provided a liquid crystal composition containing at least one species of the mesomorphic compound as described above.
The present invention further provides a liquid crystal device comprising a pair of substrates and such a liquid crystal composition as described above disposed between the electrode plates.
Heretofore, mesomorphic compounds having thiadiazole rings have been shown in D. Demus et al., "Flussige Kristalle in Tabellen II", pp. 359-361 (1984), and disclosed in Japanese Laid-Open Patent Applications (KOKAI) Nos. 51644/1987, 222148/1988 and 61472/1989 and W088/08019. With respect to a thiadiazole derivative having a naphthalene ring represented by the above formula (I) of the present invention, there is no suggestion except for W088/08019. Although W088/08019 discloses a broad general formula which can encompass the above thiadiazole derivative in its claim, there is no disclosure of a specific embodiment corresponding to the above formula (I) of the present invention. We found that the thiadiazole derivative having the naphthalene ring represented by the formula (I) had a wide temperature range of a mesomorphic phase (particularly a smectic C (SmC) phase) compared with the conventional thiadiazole derivatives. We also found that a liquid crystal device using a ferroelectric chiral smectic liquid crystal composition containing the above thiadiazole derivative of the invention showed an improved low-temperature operation characteristic, a decreased temperature-dependence of response speed, and an improved display characteristic when used in a driving method utilizing AC stabilization.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view of a liquid crystal display device using a ferroelectric liquid crystal; and
FIGS. 2 and 3 are schematic perspective views of a device cell embodiment for illustrating the operation principle of a ferroelectric liquid crystal device.
DETAILED DESCRIPTION OF THE INVENTION
In the formula (I) as described above, preferred examples of X 1 , X 2 and X 3 may respectively include the following combinations:
X 1 is a single bond, --O--, or ##STR7## X 2 is a single bond, --O--, ##STR8## and X 3 is a single bond, --O--, ##STR9## Further, preferred examples of R 1 and R 2 in the formula (I) may respectively include the following groups (i) to (iv):
(i) n-alkyl group having 1-16 carbon atoms, particularly having 3-12 carbon atoms;
(ii) ##STR10## wherein m is an integer of 1-6 and n is an integer of 2-8 (optically active or inactive);
(iii) ##STR11## wherein r is an integer of 0-6, s is 0 or 1 and t is an integer of 1-12 (optically active or inactive); and
(iv) ##STR12## wherein m is 0 or 1 and x is an integer of 1-14. Herein, * denotes an optically active center.
Further, preferred examples of A 1 and A 2 may respectively include the following combinations:
A 1 is ##STR13## or a single bond, particularly ##STR14## or a single bond; A 2 is ##STR15## or a single bond, particularly a single bond.
The compounds represented by the general formula (I) may be synthesized through the following reaction schemes A and B.
REACTION SCHEME A ##STR16##
REACTION SCHEME B ##STR17##
In a case wherein X 1 , X 2 and X 3 are respectively --O--, ##STR18## it is also possible to form a group of R 1 -X 1 -A 1 - or ##STR19## through the following steps (a) to (c):
(a) Hydroxyl group or carboxyl group combined with A 1 , a naphthalene ring or A 2 is modified with addition of a protective group into a non-reactive or less reactive group such as --OCH 3 --, ##STR20## capable of elimination reaction.
(b) Ring closure is effected.
(c) The protective group is eliminated and modified into the R 1 -X 1 -A 1 - or ##STR21## structure.
Specific examples of the mesomorphic compounds represented by the above-mentioned general formula (I) may include those shown by the following structural formulas. ##STR22##
The liquid crystal composition according to the present invention may be obtained by mixing at least one species of the compound represented by the formula (I) and at least one species of another mesomorphic compound in appropriate proportions. The liquid crystal composition according to the present invention may preferably be formulated as a ferroelectric liquid crystal composition, particularly a ferroelectric chiral smectic liquid crystal composition.
Specific examples of another mesomorphic compound as described above may include those denoted by the following structural formulas. ##STR23##
In formulating the liquid crystal composition according to the present invention, it is desirable to mix 1-500 wt. parts, preferably 2-100 wt. parts, of a compound represented by the formula (I) with 100 wt. parts of at least one species of another mesomorphic compound other than the compound represented by the formula (I).
Further, when two or more species of the compounds represented by the formula (I) are used, the two or more species of the compounds of the formula (I) may be used in a total amount of 1-500 wt. parts, preferably 2-100 wt. parts, per 100 wt. parts of at least one species of another mesomorphic compound other than the two or more species of the compounds of the formula (I).
The ferroelectric liquid crystal device according to the present invention may preferably be prepared by heating the liquid crystal composition prepared as described above into an isotropic liquid under vacuum, filling a blank cell comprising a pair of oppositely spaced electrode plates with the composition, gradually cooling the cell to form a liquid crystal layer and restoring the normal pressure.
FIG. 1 is a schematic sectional view of an embodiment of the ferroelectric liquid crystal device prepared as described above for explanation of the structure thereof.
Referring to FIG. 1, the ferroelectric liquid crystal device includes a ferroelectric liquid crystal layer 1 disposed between a pair of glass substrates 2 each having thereon a transparent electrode 3 and an insulating alignment control layer 4. Lead wires 6 are connected to the electrodes so as to apply a driving voltage to the liquid crystal layer from a power supply 7. Outside the substrates 2, a pair of polarizers 8 are disposed so as to modulate incident light I 0 from a light source 9 in cooperation with the liquid crystal 1 to provide modulated light I.
Each of two glass substrates 2 is coated with a transparent electrode 3 comprising a film of In 2 O 3 , SnO 2 or ITO (indium-tin-oxide) to form an electrode plate. Further thereon, an insulating alignment control layer 4 is formed by rubbing a film of a polymer such as polyimide with gauze or acetate fiber-planted cloth so as to align the liquid crystal molecules in the rubbing direction. Further, it is also possible to compose the alignment control layer of two layers, e.g., by first forming an insulating layer of an inorganic material, such as silicon nitride, silicon nitride containing hydrogen, silicon carbide, silicon carbide containing hydrogen, silicon oxide, boron nitride, boron nitride containing hydrogen, cerium oxide, aluminum oxide, zirconium oxide, titanium oxide, or magnesium fluoride, and forming thereon an alignment control layer of an organic insulating material, such as polyvinyl alcohol, polyimide, polyamide-imide, polyester-imide, polyparaxylylene, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose resin, melamine resin, urea resin, acrylic resin, or photoresist resin. Alternatively, it is also possible to use a single layer of inorganic insulating alignment control layer or organic insulating alignment control layer. An inorganic insulating alignment control layer may be formed by vapor deposition, while an organic insulating alignment control layer may be formed by applying a solution of an organic insulating material or a precursor thereof in a concentration of 0.1 to 20 wt. %, preferably 0.2-10 wt. %, by spinner coating, dip coating, screen printing, spray coating or roller coating, followed by curing or hardening under prescribed hardening condition (e.g., by heating). The insulating alignment control layer may have a thickness cf ordinarily 30 Å-1 micron, preferably 30-3000 Å, further preferably 50-1000 Å. The two glass substrates 2 with transparent electrodes 3 (which may be inclusively referred to herein as "electrode plates") and further with insulating alignment control layers 4 thereof are held to have a prescribed (but arbitrary) gap with a spacer 5. For example, such a cell structure with a prescribed gap may be formed by sandwiching spacers of silica beads or alumina beads having a prescribed diameter with two glass plates, and then sealing the periphery thereof with, e.g., an epoxy adhesive. Alternatively, a polymer film or glass fiber may also be used as a spacer. Between the two glass plates, a ferroelectric liquid crystal is sealed up to provide a ferroelectric liquid crystal layer 1 in a thickness of generally 0.5 to 20 microns, preferably 1 to 5 microns.
The ferroelectric liquid crystal provided by the composition of the present invention may desirably assume a SmC* phase (chiral smectic C phase) in a wide temperature range including room temperature (particularly, broad in a lower temperature side) and also shows a high-speed responsiveness, small temperature-dependence of response speed and wide drive voltage margin when contained in a device.
Particularly, in order to show a good alignment characteristic to form a uniform monodomain, the ferroelectric liquid crystal may show a phase transition series comprising isotropic phase-Ch phase (cholesteric phase)-SmA phase (smectic A phase)-SmC* phase (chiral smectic C phase) on temperature decrease.
The transparent electrodes 3 are connected to the external power supply 7 through the lead wires 6. Further, outside the glass substrates 2, polarizers 8 are applied. The device shown in FIG. 1 is of a transmission type and is provided with a light source 9.
FIG. 2 is a schematic illustration of a ferroelectric liquid crystal cell (device) for explaining operation thereof. Reference numerals 21a and 21b denote substrates (glass plates) on which a transparent electrode of, e.g., In 2 O 3 , SnO 2 , ITO (indium-tin-oxide), etc., is disposed, respectively. A liquid crystal of an SmC*-phase (chiral smectic C phase) or SmH*-phase (chiral smectic H phase) in which liquid crystal molecular layers 22 are aligned perpendicular to surfaces of the glass plates is hermetically disposed therebetween. Full lines 23 show liquid crystal molecules. Each liquid crystal molecule 23 has a dipole moment (P.sub.⊥) 24 in a direction perpendicular to the axis thereof. The liquid crystal molecules 23 continuously form a helical structure in the direction of extension of the substrates. When a voltage higher than a certain threshold level is applied between electrodes formed on the substrates 21a and 21b, a helical structure of the liquid crystal molecule 23 is unwound or released to change the alignment direction of respective liquid crystal molecules 23 so that the dipole moments (P.sub.⊥) 24 are all directed in the direction of the electric field. The liquid crystal molecules 23 have an elongated shape and show refractive anisotropy between the long axis and the short axis thereof. Accordingly, it is easily understood that when, for instance, polarizers arranged in a cross nicol relationship, i.e., with their polarizing directions crossing each other, are disposed on the upper and the lower surfaces of the glass plates, the liquid crystal cell thus arranged functions as a liquid crystal optical modulation device of which optical characteristics vary depending upon the polarity of an applied voltage.
Further, when the liquid crystal cell is made sufficiently thin (e.g., less than about 10 microns), the helical structure of the liquid crystal molecules is unwound to provide a non-helical structure even in the absence of an electric field, whereby the dipole moment assumes either of the two states, i.e., Pa in an upper direction 34e or Pb in a lower direction 34b as shown in FIG. 3, thus providing a bistable condition. When an electric field Ea or Eb higher than a certain threshold level and different from each other in polarity as shown in FIG. 3 is applied to a cell having the above-mentioned characteristics by using voltage application means 31a and 31b, the dipole moment is directed either in the upper direction 34a or in the lower direction 34b depending on the vector of the electric field Ea or Eb. In correspondence with this, the liquid crystal molecules are oriented in either of a first stable state 33a and a second stable state 33b.
When the above-mentioned ferroelectric liquid crystal is used as an optical modulation element, it is possible to obtain two advantages as described above. First is that the response speed is quite fast. Second is that the orientation of the liquid crystal molecules shows bistability. The second advantage will be further explained, e.g., with reference to FIG. 3. When the electric field Ea is applied to the liquid crystal molecules, they are oriented in the first stable state 33a. This state is stably retained even if the electric field is removed. On the other hand, when the electric field Eb of which direction is opposite to that of the electric field Ea is applied thereto, the liquid crystal molecules are oriented to the second stable state 33b, whereby the directions of molecules are changed. This state is similarly stably retained even if the electric field is removed. Further, as long as the magnitude of the electric field Ea or Eb being applied is not above a certain threshold value, the liquid crystal molecules are placed in the respective orientation states.
When such a ferroelectric liquid crystal device comprising a ferroelectric liquid crystal composition as described above between a pair of electrode plates is constituted as a simple matrix display device, the device may be driven by a driving method as disclosed in Japanese Laid-Open Patent Applications (KOKAI) Nos. 193426/1984, 193427/1984, 156046/1985, 156047/1985, etc.
Hereinbelow, the present invention will be explained more specifically with reference to examples. It is however to be understood that the present invention is not restricted to these examples.
EXAMPLE 1
2-(4-decylphenyl)-5-(6-decyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Example Compound No. 1-30) was synthesized through the following steps i) and ii). ##STR24##
In a 50 ml-three-necked flask, 0.80 g (2.89 mM) of 4-decylbenzohydrazide, 1.10 g (3.17 mM) of 6-decyloxy-2-naphthoyl chloride and 20 ml of dioxane were placed and heated to 85°-90° C. under stirring. To the mixture, 1.10 ml (13.6 mM) of pyridine was added, followed by stirring by 1 hour at 85°-90° C. After the reaction, the reaction mixture was cooled and poured into 150 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, followed by washing with water and further washing with methanol to obtain 1.69 g of N-4-decylbenzoyl-N'-(6-decyloxy-2-naphthoyl)hydrazine (Yield: 99.5%). ##STR25##
In a 50 ml-round-bottomed flask, 0.80 g (1.36 mM) of N-4-decylbenzoyl-N'-(6-decyloxy-2-naphthoyl)-hydrazine, 0.60 g (1.48 mM) of Lawesson's reagent and 12 ml of tetrahydrofuran were placed, followed by refluxing for 50 minutes under stirring. After the reaction, the reaction mixture was poured into a solution of 0.50 g of sodium hydroxide in 100 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, followed by washing with water and further washing with methanol. The resultant crystal was recrystallized from a mixture solvent (toluene-methanol) and further recrystallized from tetrahydrofuran to obtain 0.51 g of 2-(4-decylphenyl)-5-(6-decyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 64.0%). ##STR26## Herein, the respective symbols denote the following phases, Iso.: isotropic phase, SmC: smectic C phase, and Cryst.: crystal.
EXAMPLE 2
2-hexyl-5-(6-decyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Example Compound No. 1-97) was synthesized through the following steps i) and ii). ##STR27##
In a 50 ml-three-necked flask, 0.40 g (2.77 mM) of heptanohydrazide, 1.05 g (3.03 mM) of 6-decyloxy-2-naphthoyl chloride and 20 ml of dioxane were placed and heated to about 85° C. under stirring. To the mixture, 1.05 ml (13.0 mM) of pyridine was added, followed by heating to 90°-92° C. and stirring for 40 minutes at 90°-92° C. After the reaction, the reaction mixture was cooled and poured into 150 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, followed by washing with water and further washing with acetone to obtain 1.21 g of N-heptanoyl-N'-(6-decyloxy-2-naphthoyl)hydrazine (Yield: 96.0%). ##STR28##
In a 50 ml-round-bottomed flask, 1.20 g (2.64 mM) of N-heptanoyl-N'-(6-decyloxy-2-naphthoyl)-hydrazine, 1.20 g (2.97 mM) of Lawesson's reagent and 15 ml of tetrahydrofuran were placed, followed by refluxing for 45 minutes under stirring. After the reaction, the reaction mixture was poured into a solution of 0.95 g of sodium hydroxide in 100 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, followed by washing with water and purified by silica gel column chromatography (eluent: toluene). The resultant crystal was recrystallized from a mixture solvent (toluene-methanol) two times and further recrystallized from ethyl acetate and from toluene each once to obtain 0.54 g of 2-hexyl-5-(6-decyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 45.2%). ##STR29##
COMPARATIVE EXAMPLE 1
2-hexyl-5-(4-decyloxyphenyl)-1,3,4-thiadiazole was synthesized through the following reaction scheme. ##STR30##
As is apparent from Example 2 and Comparative Example 1, 2-hexyl-5-(6-decyloxynaphthalene-2-yl)-1,3,4-thiadiazole having an introduced naphthalene ring according to the present invention showed a smetic C phase in a wider temperature range.
EXAMPLE 3
2-(4-hexylphenyl)-5-(6-butoxynaphthalene-2-yl)-1,3,4-thiadiazole (Example Compound No. 1-9) was synthesized through the following steps i) to v). ##STR31##
In a 30 ml-round-bottomed flask, 2.00 g (10.6 mM) of 6-hydroxy-2-naphthoic acid, 4.0 ml of acetic anhydride and two drops of concentrated sulfuric acid were placed, followed by heat-stirring for 1 hour at about 90° C. The reaction mixture was cooled to room temperature and poured into 100 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, followed by washing with water and recrystallization from ethanol to obtain 1.48 g of 6-acetoxy-2-naphthoic acid (Yield: 60.5%).
2.0 ml of thionyl chloride and a drop of N,N-dimethylformamide were added to 1.45 g (6.30 mM) of 6-acetoxy-2-naphthoic acid, followed by refluxing for 30 minutes under stirring. Excessive thionyl chloride was distilled off from the above mixture under reduced pressure to obtain 6-acetoxy-2-naphthoyl chloride. ##STR32##
In a 100 ml-three-necked flask, 1.30 g (5.90 mM) of 4-hexylbenzohydrazide was placed and a solution of the above-prepared 6-acetoxy-2-naphthoyl chloride in 45 ml of dioxane was added thereto, followed by heating to about 83° C. To the mixture, 2.20 ml of pyridine was added under stirring, followed by stirring for 25 minutes at 83°-83.5° C. After the reaction, the reaction mixture was cooled on an iced water bath and poured into 300 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, followed by washing with water and further washing with methanol to obtain 2.22 g of N-4-hexylbenzoyl-N'-(6-acetoxy-2-naphthoyl)hydrazine (Yield: 87.0%). ##STR33##
In a 100 ml-round-bottomed flask, 2.20 g (5.09 mM) of N-4-hexylbenzoyl-N'-(6-acetoxy-2-naphthoyl)hydrazine, 2.21 g (5.46 mM) of Lawesson's reagent and 30 ml of tetrahydrofuran were placed, followed by refluxing for 40 minutes under stirring. After the reaction, the reaction mixture was cooled on an iced water bath and poured into a solution of 1.69 g of sodium hydroxide in 200 ml of iced water to precipitate a crystal. The crystal was recovered by filtration and washed with water, followed by recrystallization from acetone to obtain 1.62 g of 2-(4-hexylphenyl)-5-(6-acetoxynaphthalene-2-yl)-1,3,4-thiadiazole (Example Compound No. 1-156) (Yield: 74.0 %). ##STR34##
0.62 g (9.39 mM) of potassium hydroxide was dissolved in 30 ml of ethanol at 60°-65° C. To the solution, 1.50 g (3.48 mM) of 2-(4-hexylphenyl)-5-(6-acetoxynaphthalene-2-yl)-1,3,4-thiadiazole was added, followed by stirring for 10 minutes at 60°-65° C. The reaction mixture was poured into 100 ml of iced water and 0.83 ml of concentrated hydrochloric acid was added thereto to precipitate a crystal. The crystal was recovered by filtration and washed with water, followed by recrystallization from acetone to obtain 1.19 g of 2-(4-hexylphenyl)-5-(6-hydroxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 87.9%). ##STR35##
In a 20 ml-round-bottomed flask, 0.30 g (0.77 mM) of 2-(4-hexylphenyl)-5-(6-hydroxynaphthalene-2-yl)-1,3,4-thiadiazole, 0.08 g (1.21 mM) of potassium hydroxide was 4 ml of n-butanol were placed and dissolved at about 80° C. To the mixture, 0.12 ml (1.12 mM) of n-butyl bromide was added at 80° C. under stirring, followed by refluxing for 4 hours and 10 minutes under stirring. After the reaction, the reaction mixture was cooled on an iced water bath to precipitate a crystal. The crystal was recovered by filtration and washed with methanol. The resultant crystal was dissolved in toluene and washed with water, followed by drying with anhydrous sodium sulfate and distilling-off of the solvent. The residue was purified by silica gel column chromatography (eluent: toluene) and recrystallized from a mixture solvent (toluene-methanol) to obtain 0.25 g of 2-(4-hexylphenyl)-5(6-butoxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 72.8%) ##STR36##
COMPARATIVE EXAMPLE 2
2-(4-hexylphenyl)-5-(4-butoxyphenyl)-1,3,4-thiadiazole was synthesized through the following reaction scheme. ##STR37##
As is apparent from Example 3 and Comparative Example 2, 2-(4-hexylphenyl)-5-(6-butoxynaphthalene-2-yl)-1,3,4-thiadiazole having a naphthalene ring introduced thereto according to the present invention showed a smectic C phase in a wider temperature range.
EXAMPLE 4
2-(4-hexylphenyl)-5-(6-heptanoyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Example Compound No. 1-55) was synthesized through the following reaction scheme. ##STR38##
In a 30 ml-round-bottomed flask, 0.30 g (0.77 mM) of 2-(4-hexylphenyl)-5-(6-hydroxynaphthalene-2-yl)-1,3,4-thiadiazole was dissolved in 5 ml of pyridine. To the solution, 0.20 ml (1.29 mM) of heptanoyl chloride was added dropwise under cooling with an iced water bath and stirring. After the addition, the iced water bath was removed. Then, the mixture was stirred for 7 hours at room temperature and left standing overnight at room temperature. The resultant mixture was poured into 100 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, washed with water and dissolved in toluene under heating, followed by drying with anhydrous sodium sulfate and distilling-off of the solvent. The residue was purified by silica gel column chromatography (eluent: toluene) and recrystallized from a mixture solvent (toluene-acetone) to obtain 0.27 g of 2-(4-hexylphenyl)-5-(6-heptanoyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 69.8%) ##STR39##
EXAMPLE 5
A liquid crystal composition A was prepared by mixing the following compounds in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________173 ##STR40## 46.14174 ##STR41## 23.07245 ##STR42## 11.54233 ##STR43## 3.56246 ##STR44## 3.56234 ##STR45## 7.13247 ##STR46## 2.50249 ##STR47## 2.50__________________________________________________________________________
The liquid crystal composition A was further mixed with the following Example Compound N. 1-97 in the proportions indicated below to provide a liquid crystal composition B.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-97 ##STR48## 5 Composition A 95__________________________________________________________________________
The liquid crystal composition B showed the following phase transition series. ##STR49##
EXAMPLE 6
Two 0.7 mm-thick glass plates were provided and respectively coated with an ITO film to form an electrode for voltage application, which was further coated with an insulating layer of vapor-deposited SiO 2 . On the insulating layer, a 0.2%-solution of silane coupling agent (KBM-602, available from Shinetsu Kagaku K.K.) in isopropyl alcohol was applied by spinner coating at a speed of 2000 rpm for 15 second and subjected to hot curing treatment at 120° C. for 20 min.
Further, each glass plate provided with an ITO film and treated in the above described manner was coated with a 1.5%-solution of polyimide resin precursor (SP-510, available from Toray K.K.) in dimethylacetoamide by a spinner coater rotating at 2000 rpm for 15 seconds. Thereafter, the coating film was subjected to heat curing at 300° C. for 60 min. to obtain about 250 Å-thick film. The coating film was rubbed with acetate fiber-planted cloth. The thus treated two glass plates were washed with isopropyl alcohol. After alumina beads with an average particle size of 2.0 microns were dispersed on one of the glass plates, the two glass plates were applied to each other with a bonding sealing agent (Lixon Bond, available from Chisso K.K.) so that their rubbed directions were parallel to each other and heated at 100° C. for 60 min. to form a blank cell. The cell gap was found to be about 2 microns as measured by a Berek compensator.
Then, the liquid crystal composition B prepared in Example 5 was heated into an isotropic liquid, and injected into the above prepared cell under vacuum and, after sealing, was gradually cooled at a rate of 20° C./hour to 25° C. to prepare a ferroelectric liquid crystal device.
The ferroelectric liquid crystal device was subjected to measurement of the magnitude of spontaneous polarization Ps and optical response time (time from voltage application until the transmittance change reaches 90% of the maximum under the application of a peak-to-peak voltage Vpp of 20 V in combination with right-angle cross-nicol polarizers).
The results are shown below.
______________________________________ 10° C. 30° C. 45° C.______________________________________Response time (μsec) 488 232 135Ps (nC/cm.sup.2) 3.43 2.64 1.66______________________________________
EXAMPLE 7
A liquid crystal composition C was prepared by mixing the following compounds in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________173 ##STR50## 51.57174 ##STR51## 25.79245 ##STR52## 12.89233 ##STR53## 1.19246 ##STR54## 1.19234 ##STR55## 2.37247 ##STR56## 2.50249 ##STR57## 2.50__________________________________________________________________________
The liquid crystal composition C was further mixed with the following Example Compound No. 1-9 in the proportions indicated below to provide a liquid crystal composition D.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-9 ##STR58## 10 Composition C 90__________________________________________________________________________
The liquid crystal composition D showed the following phase transition series. ##STR59##
EXAMPLE 8
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the above liquid crystal composition D, and subjected to measurement of the magnitude of spontaneous polarization Ps and optical response time in the same manner as in Example 6.
The results are shown below.
______________________________________ 10° C. 30° C. 45° C.______________________________________Response time (μsec) 804 307 180Ps (nC/cm.sup.2) 4.27 2.90 1.96______________________________________
EXAMPLE 9
A liquid crystal composition E was prepared by mixing the following compounds in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________ 20 ##STR60## 15 21 ##STR61## 15 58 ##STR62## 10 89 ##STR63## 20120 ##STR64## 13129 ##STR65## 7236 ##STR66## 15242 ##STR67## 5__________________________________________________________________________
The liquid crystal composition E was further mixed with the following Example Compounds in the proportions respectively indicated below to provide a liquid crystal composition F.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-3 ##STR68## 31-25 ##STR69## 2 Composition E 95__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except that the liquid crystal composition F was injected into a cell. The measured values of the response time of the device were as follows.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 141 95 81______________________________________
COMPARATIVE EXAMPLE 3
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except that the liquid crystal composition E prepared in Example 9 was injected into a cell. The measured values of the response time of the device were as follows.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 155 100 80______________________________________
EXAMPLE 10
A liquid crystal composition G was prepared in the same manner as in Example 9 except that the following Example Compounds were used instead of Examples Compounds Nos. 1-3 and 1-25 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-10 ##STR70## 21-38 ##STR71## 31-56 ##STR72## 2 Composition E 93__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition G. The ferroelectric liquid crystal device was subjected to measurement of response time in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 128 88 77______________________________________
EXAMPLE 11
A liquid crystal composition H was prepared in the same manner as in Example 9 except that the following Example Compounds were used instead of Example Compounds Nos. 1-3 and 1-25 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-60 ##STR73## 21-69 ##STR74## 2 1-104 ##STR75## 2 Composition E 94__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition H. The ferroelectric liquid crystal device was subjected to measurement of response time in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 132 90 82______________________________________
EXAMPLE 12
A liquid crystal composition I was prepared in the same manner as in Example 9 except that the following Example Compounds were used instead of Example Compounds Nos. 1-3 and 1-25 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-98 ##STR76## 21-116 ##STR77## 21-120 ##STR78## 21-132 ##STR79## 3 Composition E 91__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition I. The ferroelectric liquid crystal device was subjected to measurement of response time in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 132 95 80______________________________________
EXAMPLE 13
A liquid crystal composition J was prepared in the same manner as in Example 9 except that the following Example Compounds were used instead of Example Compounds Nos. 1-3 and 1-25 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-71 ##STR80## 21-72 ##STR81## 11-83 ##STR82## 2 1-108 ##STR83## 2 Composition E 93__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition J. The ferroelectric liquid crystal device was subjected to measurement of response time in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 134 99 81______________________________________
EXAMPLE 14
A liquid crystal composition K was prepared by mixing the following compounds in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________ 8 ##STR84## 16 9 ##STR85## 22.518 ##STR86## 6423 ##STR87## 1024 ##STR88## 1043 ##STR89## 22.563 ##STR90## 1587 ##STR91## 15124 ##STR92## 6.75136 ##STR93## 18.75236 ##STR94## 20__________________________________________________________________________
The liquid crystal composition K was further mixed with the following Example Compounds in the proportions respectively indicated below to provide a liquid crystal composition L.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-6 ##STR95## 11-64 ##STR96## 11-73 ##STR97## 2 1-106 ##STR98## 2 Composition K 94__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition L. In the ferroelectric liquid crystal device, a monodomain with a good and uniform alignment characteristic was observed. The ferroelectric liquid crystal device was subjected to measurement of response time and observation of a switching state, etc. in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 379 253 198______________________________________
COMPARATIVE EXAMPLE 4
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except that the liquid crystal composition K prepared in Example 14 was injected into a cell. The measured values of the response time of the device were as follows.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 450 270 195______________________________________
EXAMPLE 15
A liquid crystal composition M was prepared in the same manner as in Example 14 except that the following Example Compounds were used instead of Example Compounds Nos. 1-6, 1-64, 1-73 and 1-106 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-44 ##STR99## 31-52 ##STR100## 11-103 ##STR101## 21-111 ##STR102## 2 Composition K 92__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition M. In the ferroelectric liquid crystal device, a monodomain with a good and uniform alignment characteristic was observed. The ferroelectric liquid crystal device was subjected to measurement of response time and observation of a switching state, etc. in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 316 208 173______________________________________
Further, when the device was driven, a clear switching action was observed, and good bistability was shown after the termination of the voltage application.
EXAMPLE 16
A liquid crystal composition N was prepared in the same manner as in Example 14 except that the following Example Compounds were used instead of Example Compounds Nos. 1-6, 1-64, 1-73 and 1-106 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-15 ##STR103## 11-61 ##STR104## 11-113 ##STR105## 21-118 ##STR106## 3 Composition K 93__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition N. In the ferroelectric liquid crystal device, a monodomain with a good and uniform alignment characteristic was observed. The ferroelectric liquid crystal device was subjected to measurement of response time and observation of a switching state, etc. in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 321 210 176______________________________________
Further, when the device was driven, a clear switching action was observed, and good bistability was shown after the termination of the voltage application.
EXAMPLE 17
A liquid crystal composition O was prepared in the same manner as in Example 14 except that the following Example Compounds were used instead of Example Compounds Nos. 1-6, 1-64, 1-73 and 1-106 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-20 ##STR107## 11-112 ##STR108## 21-119 ##STR109## 21-136 ##STR110## 1 Composition K 94__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition O. In the ferroelectric liquid crystal device, a monodomain with a good and uniform alignment characteristic was observed. The ferroelectric liquid crystal device was subjected to measurement of response time and observation of a switching state, etc. in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 351 237 188______________________________________
Further, when the device was driven, a clear switching action was observed, and good bistability was shown after the termination of the voltage application.
EXAMPLE 18
A liquid crystal composition P was prepared by mixing the following compounds in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________250 ##STR111## 18 19 ##STR112## 18 81 ##STR113## 8 11 ##STR114## 8251 ##STR115## 12252 ##STR116## 12253 ##STR117## 6170 ##STR118## 6174 ##STR119## 6195 ##STR120## 4203 ##STR121## 2__________________________________________________________________________
The liquid crystal composition P was further mixed with the following Example Compounds in the proportions respectively indicated below to provide a liquid crystal composition Q.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-11 ##STR122## 21-88 ##STR123## 3 1-121 ##STR124## 1 Composition P 94__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition Q. The ferroelectric liquid crystal device was subjected to measurement of response time in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 15° C. 25° C. 40° C.______________________________________Response time (μsec) 1760 491 153______________________________________
COMPARATIVE EXAMPLE 5
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except that the liquid crystal composition P prepared in Example 18 was injected into a cell. The measured values of the response time of the device were as follows.
______________________________________ 15° C. 25° C. 40° C.______________________________________Response time (μsec) 1980 548 170______________________________________
EXAMPLE 19
A liquid crystal composition R was prepared in the same manner as in Example 18 except that the following Example Compounds were used instead of Example Compounds Nos. 1-11, 1-88 and 1-121 in respectively indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-142 ##STR125## 11-146 ##STR126## 11-153 ##STR127## 2 Composition P 96__________________________________________________________________________
A ferroelectric liquid crystal device was prepared in the same manner as in Example 6 except for using the composition R. In the ferroelectric liquid crystal device, a monodomain with a good and uniform alignment characteristic was observed. The ferroelectric liquid crystal device was subjected to measurement of response time and observation of a switching state, etc. in the same manner as in Example 6, whereby the following results were obtained.
______________________________________ 10° C. 25° C. 40° C.______________________________________Response time (μsec) 1790 496 151______________________________________
Further, when the device was driven, a clear switching action was observed, and good bistability was shown after the termination of the voltage application.
As is apparent from the results shown in the above Examples 9-19, the ferroelectric liquid crystal devices containing the liquid crystal compositions F to J, L to O, Q and R showed an improved low-temperature operation characteristic, a high-speed responsiveness, and a decreased temperature dependence of the response speed.
EXAMPLE 20
A blank cell was prepared in the same manner as in Example 6 by using a 2% aqueous solution of polyvinyl alcohol resin (PVA-117, available from Kuraray K.K.) instead of the 1.5%-solution of polyimide resin precursor in dimethylacetoamide on each electrode plate. A ferroelectric liquid crystal device was prepared by filling the blank cell with the liquid crystal composition I prepared in Example 12. The liquid crystal device was subjected to measurement of optical response time in the same manner as in Example 6. The results are shown below.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 120 86 70______________________________________
EXAMPLE 21
A blank cell was prepared in the same manner as in Example 6 except for omitting the SiO 2 layer to form an alignment control layer composed of the polyimide resin layer alone on each electrode plate. A ferroelectric liquid crystal device was prepared by filling the blank cell with the liquid crystal composition I prepared in Example 12. The liquid crystal device was subjected to measurement of optical response time in the same manner as in Example 6. The results are shown below.
______________________________________ 15° C. 25° C. 35° C.______________________________________Response time (μsec) 118 84 72______________________________________
As is apparent from the above Examples 20 and 21, also in the cases of different device structures, the devices containing the ferroelectric liquid crystal composition I according to the present invention respectively provided a remarkably improved operation characteristic at a lower temperature and also a decreased temperature-dependence of the response speed similar to those in Example 12.
EXAMPLE 22
A commercially available ferroelectric liquid crystal ("CS-1014" available from Chisso K.K.) having a Δε of nearly O (Δε≈-0.4 (sine wave, 100 kHz)) and the following example compounds were mixed in the proportions respectively indicated below to prepare a liquid crystal composition S.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-5 ##STR128## 11-40 ##STR129## 11-80 ##STR130## 2 1-101 ##STR131## 2 CS-1014 94__________________________________________________________________________
Ferroelectric liquid crystal devices were prepared in the same manner as in Example 6 except that the above liquid crystal CS1014 and the liquid crystal composition S were used respectively and the liquid crystal layer thicknesses were changed to 1.5 microns.
The above liquid crystal devices were subjected to measurement of a tilt angle under right angle cross nicols at 25° C. Then, the devices were subjected application of a ±8 V rectangular waveform at a frequency of 60 kHz, and the tilt angles were measured under the voltage application and microscopic observation. Under these conditions, the transmittances and contrast ratios were also measured. The results are shown below.
______________________________________ CS-1014 Composition S______________________________________Tilt angle (under right 7 degrees 7.6 degreesangle cross nicols)Tilt angle (under appli- 8.8 degrees 12.8 degreescation ±8V, 60 KHz)Transmittance (under 7.8% 11.9%application ±8V, 60 KHz)Contrast ratio (under 8:1 31:1application ±8V, 60 KHz)______________________________________
EXAMPLE 23
A liquid crystal composition T was prepared in the same manner as in Example 22 except that the following example compounds were used in the indicated proportions.
__________________________________________________________________________Ex. Comp. No. Structural formula wt. parts__________________________________________________________________________1-51 ##STR132## 11-90 ##STR133## 21-109 ##STR134## 21-129 ##STR135## 2 CS-1014 93__________________________________________________________________________
Ferroelectric liquid crystal devices were prepared in the same manner as in Example 6 except that the above liquid crystal CS1014 and the liquid crystal composition T were used respectively and the liquid crystal layer thicknesses were changed to 1.5 microns.
The above liquid crystal devices were subjected to measurement of a tilt angle under right angle cross nicols at 25° C. Then, the devices were subjected application of a ±8 V rectangular waveform at a frequency of 60 kHz, and the tilt angles were measured under the voltage application and microscopic observation. Under these conditions, the transmittances and contrast ratios were also measured. The results are shown below.
______________________________________ CS-1014 Composition T______________________________________Tilt angle (under right 7 degrees 8.0 degreesangle cross nicols)Tilt angle (under appli- 8.8 degrees 14.1 degreescation ±8V, 60 KHz)Transmittance (under 7.8% 13.2%application ±8V, 60 KHz)Contrast ratio (under 8:1 38:1application ±8V, 60 KHz)______________________________________
The above results of Examples 22 and 23 show the addition of the mesomorphic compound example of the present invention to a liquid crystal CS 1014 having a Δε of nearly O provided a liquid crystal device showing improved display characteristics due to AC stabilization effect.
EXAMPLE 24
2-hexyl-5-(6-heptanoyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Example Compound No. 1-163) was synthesized through the following steps i) to iii). ##STR136##
In a 200 ml-three-necked flask, 1.77 g (12.3 mM) of heptanohydrazide, 3,23 g (13.0 mM) of 6-acetoxy-2-naphthoyl chloride prepared in the same manner as in Example 3 and 90 ml of dioxane were placed and heated to about 80° C. To the mixture, 5.0 ml of pyridine was added at about 80° C. under stirring, followed by heating to 90°-92° C. and stirring for 1 hour at 90°-92° C. After the reaction, the reaction mixture was cooled on an iced water bath and poured into 350 ml of iced water to precipitate a crystal. The crystal was recovered by filtration, followed by washing with water and recrystallization from a mixture solvent (acetoneethyl acetate) to obtain 3.23 g of N-heptanoyl-N'-(6-acetoxy-2-naphthoyl)hydrazine (Yield: 75.4 %) ##STR137##
In a 100 ml-round-bottomed flask, 3.00 g (8.42 mM) of N-heptanoyl-N'-(6-acetoxy-2-naphthoyl)hydrazine, 3.83 g (9.47 mM) of Lawesson's reagent and 40 ml of tetrahydrofuran were placed, followed by refluxing for 1 hour under stirring. After the reaction, the reaction mixture was cooled on an iced water bath and poured into a solution of 3.00 g of sodium hydroxide in 250 ml of iced water to precipitate a crystal. The crystal was recovered by filtration and washed with water to obtain 2.92 g of 2-hexyl-5-(6-acetoxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 97.9 %).
1.50 g (22.7 mM) of potassium hydroxide was dissolved in 72 ml of ethanol at 60°-65° C. To the solution, 2.90 g (8.18 mM) of 2-hexyl-5-(6-acetoxynaphthalene-2-yl)-1,3,4-thiadiazole was added, followed by stirring for 20 minutes at 60°-65° C. The reaction mixture was poured into 200 ml of iced water and 3 ml of concentrated hydrochloric acid was added thereto to precipitate a crystal. The crystal was recovered by filtration and washed with water to obtain 1.90 g of 2-hexyl-5-(6-hydroxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 71.9 %). ##STR138##
In a 30 ml-round-bottomed flask, 0.60 g (1.92 mM) of 2-hexyl-5-(6-hydroxynaphthalene-2-yl)-1,3,4-thiadiazole, 0.25 g (1.92 mM) of heptanoic acid were dissolved in 10 ml of dichloromethane. Under stirring, 0.39 g (1.89 mM) of N,N'-dicyclohexylcarbodiimide and 0.02 g of 4-pyrrolidinopyridine were successively added the above solution at room temperature, followed by stirring for 8 hours at room temperature. After the reaction, precipitated N,N'-dicyclohexylurea was filtered off and the filtrate was dried off under reduced pressure to obtain a solid. The solid was purified by silica gel column chromatography (eluent: toluene/ethyl acetate=3/1) and recrystallized from a mixture solvent (ethanol-ethyl acetate) to obtain 0.42 g of 2-hexyl-5-(6-heptanoyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 81.5 %). ##STR139##
EXAMPLE 25
2-hexyl-5-(6-hexyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Example Compound No. 1-157) was synthesized through the following reaction scheme. ##STR140##
In a 50 ml-round-bottomed flask, 0.60 g (1.92 mM) of 2-hexyl-5-(6-hydroxynaphthalene-2-yl)-1,3,4-thiadiazole prepared in Step ii) of Example 24, 0.18 g (2.73 mM) of potassium hydroxide and 15 ml of butanol were placed and dissolved under heating. To the mixture, 0.53 g (2.50 mM) of hexyl iodide was added at about 100° C. under stirring, followed by refluxing for 6 hours under stirring. After the reaction, butanol was distilled off under reduced pressure, and water and ethyl acetate were added to the residue, followed by stirring. The resultant organic layer was washed with water, followed by drying with anhydrous sodium sulfate and distilling-off of the solvent to obtain a solid. The solid was purified by silica gel column chromatography (eluent: benzene) and recrystallized from a mixture solvent (ethyl acetate-ethanol) to obtain 0.27 g of 2-hexyl-5-(6-hexyloxynaphthalene-2-yl)-1,3,4-thiadiazole (Yield: 35.5 %). ##STR141##
As described hereinabove, the ferroelectric liquid crystal composition according to the present invention provides a liquid crystal device which shows a good switching characteristic, an improved operation characteristic at a lower temperature and a decreased temperature dependence of response speed. Further, the liquid crystal composition according to the present invention provides a liquid crystal device which shows a remarkably improved display characteristic when used in a driving method utilizing AC stabilization. | A mesomorphic compound represented by the following formula (I): ##STR1## wherein R 1 and R 2 respectively denote an alkyl group having 1-16 carbon atoms capable of having a substituent; X 1 , X 2 and X 3 respectively denote a single bond, --O--, ##STR2## A 1 and A 2 respectively ##STR3## wherein X 4 and X 5 respectively denote hydrogen, fluorine, chlorine, bromine, --CH 3 , --CN or --CF 3 with proviso that X 1 always denotes a single bond when A 1 denotes a single bond; and n is 0 or 1. | 2 |
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