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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of copending application Ser. No. 13/076,631 filed Mar. 31, 2011, the contents of which are hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The field of the invention is the production of diesel by hydrocracking
BACKGROUND OF THE INVENTION
[0003] Hydrocracking refers to a process in which hydrocarbons crack in the presence of hydrogen and catalyst to lower molecular weight hydrocarbons. Depending on the desired output, the hydrocracking zone may contain one or more beds of the same or different catalyst.
[0004] Hydrocracking is a process used to crack hydrocarbon feeds such as vacuum gas oil (VGO) to diesel including kerosene and gasoline motor fuels.
[0005] Mild hydrocracking is generally used upstream of a fluid catalytic cracking (FCC) or other process unit to improve the quality of an unconverted oil that can be fed to the downstream unit, while converting part of the feed to lighter products such as diesel. As world demand for diesel motor fuel is growing relative to gasoline motor fuel, mild hydrocracking is being considered for biasing the product slate in favor of diesel at the expense of gasoline. Mild hydrocracking may be operated with less severity than partial or full conversion hydrocracking to balance production of diesel with the FCC unit, which primarily is used to make naphtha. Partial or full conversion hydrocracking is used to produce diesel with less yield of the unconverted oil which can be fed to a downstream unit.
[0006] Due to environmental concerns and newly enacted rules and regulations, saleable diesel must meet lower and lower limits on contaminates, such as sulfur and nitrogen. New regulations require essentially complete removal of sulfur from diesel. For example, the ultra low sulfur diesel (ULSD) requirement is typically less than about 10 wppm sulfur.
[0007] There is a continuing need, therefore, for improved methods of producing more diesel from hydrocarbon feedstocks than gasoline. Such methods must ensure that the diesel product meets increasingly stringent product requirements.
BRIEF SUMMARY OF THE INVENTION
[0008] In an apparatus embodiment, the invention comprises an apparatus for producing diesel comprising a hydrocracking reactor in communication with one or more compressors on a make-up hydrogen line and a hydrocarbon feed line for hydrocracking the hydrocarbon stream to lower boiling hydrocarbons. A recycle gas compressor is in communication with the hydrocracking reactor for compressing a vaporous hydrocracking effluent stream comprising hydrogen to provide a recycle hydrogen stream in a recycle hydrogen line. A hydrotreating reactor is in communication with the recycle hydrogen line and the hydrocracking reactor for hydrotreating a diesel stream to produce low sulfur diesel.
[0009] In an additional apparatus embodiment, the invention further comprises a warm separator in communication with the hydrotreating reactor for separating the hydrotreating effluent stream into a vaporous hydrotreating effluent stream comprising hydrogen in an overhead line and a liquid hydrotreating effluent stream in a bottoms line and the recycle gas compressor in communication with the overhead line.
[0010] In a further apparatus embodiment, the invention comprises an apparatus for producing diesel comprising a make-up hydrogen stream with one or more compressors in communication with the make-up hydrogen line for compressing the make-up hydrogen stream.
[0011] A hydrocarbon feed line is for carrying a hydrocarbon stream. A hydrocracking reactor is in communication with the make-up hydrogen line and the hydrocarbon feed line for hydrocracking the hydrocarbon stream to lower boiling hydrocarbons. A recycle gas compressor is in communication with the hydrocracking reactor for compressing a vaporous hydrocracking effluent stream comprising hydrogen to provide a recycle hydrogen stream in a recycle hydrogen line. A fractionation section is in communication with the hydrocracking reactor for fractionating a liquid hydrocracking effluent stream to produce a diesel stream carried in a diesel line. A hydrotreating reactor is in communication with the recycle hydrogen line and the diesel line for hydrotreating the diesel stream to produce low sulfur diesel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a simplified process flow diagram of an embodiment of the present invention.
[0013] FIG. 2 is a simplified process flow diagram of an alternative embodiment of the present invention.
DEFINITIONS
[0014] The term “communication” means that material flow is operatively permitted between enumerated components.
[0015] The term “downstream communication” means that at least a portion of material flowing to the subject in downstream communication may operatively flow from the object with which it communicates.
[0016] The term “upstream communication” means that at least a portion of the material flowing from the subject in upstream communication may operatively flow to the object with which it communicates.
[0017] The term “column” means a distillation column or columns for separating one or more components of different volatilities. Unless otherwise indicated, each column includes a condenser on an overhead of the column to condense and reflux a portion of an overhead stream back to the top of the column and a reboiler at a bottom of the column to vaporize and send a portion of a bottoms stream back to the bottom of the column. Feeds to the columns may be preheated. The top pressure is the pressure of the overhead vapor at the vapor outlet of the column. The bottom temperature is the liquid bottom outlet temperature. Overhead lines and bottoms lines refer to the net lines from the column downstream of the reflux or reboil to the column.
[0018] As used herein, the term “True Boiling Point” (TBP) means a test method for determining the boiling point of a material which corresponds to ASTM D2892 for the production of a liquefied gas, distillate fractions, and residuum of standardized quality on which analytical data can be obtained, and the determination of yields of the above fractions by both mass and volume from which a graph of temperature versus mass % distilled is produced using fifteen theoretical plates in a column with a 5:1 reflux ratio.
[0019] As used herein, the term “conversion” means conversion of feed to material that boils at or below the diesel boiling range. The cut point of the diesel boiling range is between about 343° and about 399° C. (650° to 750° F.) using the True Boiling Point distillation method.
[0020] As used herein, the term “diesel boiling range” means hydrocarbons boiling in the range of between about 132° and about 399° C. (270° to 750° F.) using the True Boiling Point distillation method.
DETAILED DESCRIPTION
[0021] Mild hydrocracking reactors operate at low severity and therefore low conversion.
[0022] The diesel produced from mild hydrocracking is not of sufficient quality to meet applicable fuel specifications particularly with regard to sulfur. As a result, the diesel produced from mild hydrocracking must be processed in a hydrotreating unit to allow blending into finished diesel. In many cases, it is attractive to integrate the mild hydrocracking unit and the hydrotreating units to reduce capital and operating costs.
[0023] A typical hydrocracking unit has both a cold separator and a cold flash drum. It often, but not always, has a hot separator and a hot flash drum. A typical hydrotreating unit has only a cold separator. The cold separator may be operated at a lower temperature for obtaining optimal hydrogen separation for use as recycle gas, but this proves thermally inefficient as the hydrotreated liquid stream must be reheated for fractionation to obtain the low sulfur diesel.
[0024] To avoid this cooling and reheating without impacting the hydrogen separation, a hydrotreating unit is utilized in parallel with hydrocracking unit, a common recycle gas compressor and a cold separator. The recycle gas splits to each unit after compression. Make-up gas can be added to the recycle gas stream upstream to the recycle gas compressor. If make-up gas is added downstream of the recycle gas compressor, it should be added solely to the hydrocracking recycle gas to improve hydrogen partial pressure in the hydrocracking reactor.
[0025] The hydrotreating unit may employ a warm separator to extract a warm liquid product and then combine the vaporous hydrotreating effluent phase with the hydrocracking effluent.
[0026] This arrangement allows the hydrotreating and hydrocracking units to operate at similar pressures. Additionally, the vaporous hydrotreating effluent may be sent to the cold separator to further separate hydrogen from hydrocarbon to provide recycle gas. The liquid hydrotreating effluent from the warm separator does not have to be reheated as much before fractionation. Furthermore, the liquid hydrotreating effluent comprises predominantly low sulfur diesel, so fractionation of the low sulfur diesel is simpler.
[0027] The invention involves sending all makeup gas through the hydrocracking unit with recycle gas. The makeup gas addition to the hydrocracking unit is advantageous because the feedstock to the hydrocracking reactor will typically have much higher coke precursors than the diesel feed to the hydrotreating unit which leads to higher catalyst deactivation rates and shorter catalyst life. Using the make-up gas to increase the hydrogen partial pressure in the hydrocracking reactor will render the hydrocracking operation more efficient.
[0028] The apparatus and process 8 for producing diesel comprise a compression section 10 , a hydrocracking unit 12 , a hydrotreating unit 14 and a fractionation zone 16 . Hydrocarbon feed is first fed to the hydrocracking unit 12 and converted to lower boiling hydrocarbons including diesel. The diesel is fractionated in a fractionation section therein and forwarded to the hydrotreating unit 14 to provide lower sulfur diesel.
[0029] A make-up hydrogen stream 20 is fed to a train of one or more compressors 22 and 24 in the compression section 10 to boost the pressure of the make-up hydrogen stream and provide a compressed make-up stream in line 26 . The compressed make-up stream in line 26 may join with a first recycle hydrogen split stream in line 28 to provide a hydrocracking hydrogen stream in line 30 . The hydrocracking hydrogen stream in line 30 taken from the compressed make-up hydrogen stream in line 26 may join a hydrocarbon feed stream in line 32 to provide a hydrocracking feed stream in line 34 .
[0030] The hydrocarbon feed stream is introduced in line 32 perhaps through a surge tank.
[0031] In one aspect, the process and apparatus described herein are particularly useful for hydroprocessing a hydrocarbonaceous feedstock. Illustrative hydrocarbon feedstocks include hydrocarbonaceous streams having components boiling above about 288° C. (550° F.), such as atmospheric gas oils, VGO, deasphalted, vacuum, and atmospheric residua, coker distillates, straight run distillates, solvent-deasphalted oils, pyrolysis-derived oils, high boiling synthetic oils, cycle oils, hydrocracked feeds, cat cracker distillates and the like. These hydrocarbonaceous feed stocks may contain from about 0.1 to about 4 wt-% sulfur.
[0032] A suitable hydrocarbonaceous feedstock is a VGO or other hydrocarbon fraction having at least about 50 percent by weight, and usually at least about 75 percent by weight, of its components boiling at a temperature above about 399° C. (750° F.). A typical VGO normally has a boiling point range between about 315° C. (600° F.) and about 565° C. (1050° F.).
[0033] Hydrocracking refers to a process in which hydrocarbons crack in the presence of hydrogen to lower molecular weight hydrocarbons. A hydrocracking reactor 36 is in downstream communication with the one or more compressors 22 and 24 on the make-up hydrogen line 20 and the hydrocarbon feed line 30 . The hydrocracking feed stream in line 34 may be heat exchanged with a hydrocracking effluent stream in line 38 and further heated in a fired heater before entering the hydrocracking reactor 36 for hydrocracking the hydrocarbon stream to lower boiling hydrocarbons.
[0034] The hydrocracking reactor 36 may comprise one or more vessels, multiple beds of catalyst in each vessel, and various combinations of hydrotreating catalyst and hydrocracking catalyst in one or more vessels. In some aspects, the hydrocracking reaction provides total conversion of at least about 20 vol-% and typically greater than about 60 vol-% of the hydrocarbon feed to products boiling below the diesel cut point. The hydrocracking reactor 42 may operate at partial conversion of more than about 50 vol-% or full conversion of at least about 90 vol-% of the feed based on total conversion. To maximize diesel, full conversion is effective. The first vessel or bed may include hydrotreating catalyst for the purpose of demetallizing, desulfurizing or denitrogenating the hydrocracking feed.
[0035] The hydrocracking reactor 36 may be operated at mild hydrocracking conditions. Mild hydrocracking conditions will provide about 20 to about 60 vol-%, preferably about 20 to about 50 vol-%, total conversion of the hydrocarbon feed to product boiling below the diesel cut point. In mild hydrocracking, converted products are biased in favor of diesel. In a mild hydrocracking operation, the hydrotreating catalyst has just as much or a greater conversion role than hydrocracking catalyst. Conversion across the hydrotreating catalyst may be a significant portion of the overall conversion. If the hydrocracking reactor 36 is intended for mild hydrocracking, it is contemplated that the mild hydrocracking reactor 36 may be loaded with all hydrotreating catalyst, all hydrocracking catalyst, or some beds of hydrotreating catalyst and beds of hydrocracking catalyst. In the last case, the beds of hydrocracking catalyst may typically follow beds of hydrotreating catalyst. Most typically, three beds of hydrotreating catalyst may be followed by zero, one or two 2 beds of hydrocracking catalyst.
[0036] The hydrocracking reactor 36 in FIG. 1 has four beds in one reactor vessel. If mild hydrocracking is desired, it is contemplated that the first three catalyst beds comprise hydrotreating catalyst and the last catalyst bed comprise hydrocracking catalyst. If partial or full hydrocracking is preferred, additional beds of hydrocracking catalyst may be used than in mild hydrocracking
[0037] At mild hydrocracking conditions, the feed is selectively converted to heavy products such as diesel and kerosene with a low yield of lighter hydrocarbons such as naphtha and gas. Pressure is also moderate to limit the hydrogenation of the bottoms product to an optimal level for downstream processing.
[0038] In one aspect, for example, when a balance of middle distillate and gasoline is preferred in the converted product, mild hydrocracking may be performed in the first hydrocracking reactor 36 with hydrocracking catalysts that utilize amorphous silica-alumina bases or low-level zeolite bases combined with one or more Group VIII or Group VIB metal hydrogenating components. In another aspect, when middle distillate is significantly preferred in the converted product over gasoline production, partial or full hydrocracking may be performed in the first hydrocracking reactor 36 with a catalyst which comprises, in general, any crystalline zeolite cracking base upon which is deposited a Group VIII metal hydrogenating component. Additional hydrogenating components may be selected from Group VIB for incorporation with the zeolite base.
[0039] The zeolite cracking bases are sometimes referred to in the art as molecular sieves and are usually composed of silica, alumina and one or more exchangeable cations such as sodium, magnesium, calcium, rare earth metals, etc. They are further characterized by crystal pores of relatively uniform diameter between about 4 and about 14 Angstroms (10 −10 meters). It is preferred to employ zeolites having a relatively high silica/alumina mole ratio between about 3 and about 12. Suitable zeolites found in nature include, for example, mordenite, stilbite, heulandite, ferrierite, dachiardite, chabazite, erionite and faujasite. Suitable synthetic zeolites include, for example, the B, X, Y and L crystal types, e.g., synthetic faujasite and mordenite. The preferred zeolites are those having crystal pore diameters between about 8-12 Angstroms (10 −10 meters), wherein the silica/alumina mole ratio is about 4 to 6. One example of a zeolite falling in the preferred group is synthetic Y molecular sieve.
[0040] The natural occurring zeolites are normally found in a sodium form, an alkaline earth metal form, or mixed forms. The synthetic zeolites are nearly always prepared first in the sodium form. In any case, for use as a cracking base it is preferred that most or all of the original zeolitic monovalent metals be ion-exchanged with a polyvalent metal and/or with an ammonium salt followed by heating to decompose the ammonium ions associated with the zeolite, leaving in their place hydrogen ions and/or exchange sites which have actually been decationized by further removal of water. Hydrogen or “decationized” Y zeolites of this nature are more particularly described in U.S. Pat. No. 3,130,006.
[0041] Mixed polyvalent metal-hydrogen zeolites may be prepared by ion-exchanging first with an ammonium salt, then partially back exchanging with a polyvalent metal salt and then calcining In some cases, as in the case of synthetic mordenite, the hydrogen forms can be prepared by direct acid treatment of the alkali metal zeolites. In one aspect, the preferred cracking bases are those which are at least about 10 percent, and preferably at least about 20 percent, metal-cation-deficient, based on the initial ion-exchange capacity. In another aspect, a desirable and stable class of zeolites is one wherein at least about 20 percent of the ion exchange capacity is satisfied by hydrogen ions.
[0042] The active metals employed in the preferred hydrocracking catalysts of the present invention as hydrogenation components are those of Group VIII, i.e., iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum. In addition to these metals, other promoters may also be employed in conjunction therewith, including the metals of Group VIB, e.g., molybdenum and tungsten. The amount of hydrogenating metal in the catalyst can vary within wide ranges. Broadly speaking, any amount between about 0.05 percent and about 30 percent by weight may be used. In the case of the noble metals, it is normally preferred to use about 0.05 to about 2 wt-%.
[0043] The method for incorporating the hydrogenating metal is to contact the base material with an aqueous solution of a suitable compound of the desired metal wherein the metal is present in a cationic form. Following addition of the selected hydrogenating metal or metals, the resulting catalyst powder is then filtered, dried, pelleted with added lubricants, binders or the like if desired, and calcined in air at temperatures of, e.g., about 371° to about 648° C. (about 700° to about 1200° F.) in order to activate the catalyst and decompose ammonium ions. Alternatively, the base component may first be pelleted, followed by the addition of the hydrogenating component and activation by calcining
[0044] The foregoing catalysts may be employed in undiluted form, or the powdered catalyst may be mixed and copelleted with other relatively less active catalysts, diluents or binders such as alumina, silica gel, silica-alumina cogels, activated clays and the like in proportions ranging between about 5 and about 90 wt-%. These diluents may be employed as such or they may contain a minor proportion of an added hydrogenating metal such as a Group VIB and/or Group VIII metal. Additional metal promoted hydrocracking catalysts may also be utilized in the process of the present invention which comprises, for example, aluminophosphate molecular sieves, crystalline chromosilicates and other crystalline silicates. Crystalline chromosilicates are more fully described in U.S. Pat. No. 4,363,718.
[0045] By one approach, the hydrocracking conditions may include a temperature from about 290° C. (550° F.) to about 468° C. (875° F.), preferably 343° C. (650° F.) to about 435° C. (815° F.), a pressure from about 3.5 MPa (500 psig) to about 20.7 MPa (3000 psig), a liquid hourly space velocity (LHSV) from about 1.0 to less than about 2.5 hr − and a hydrogen rate of about 421 to about 2,527 Nm 3 /m 3 oil (2,500-15,000 scf/bbl). If mild hydrocracking is desired, conditions may include a temperature from about 315° C. (600° F.) to about 441° C. (825° F.), a pressure from about 5.5 to about 13.8 MPa (gauge) (800 to 2000 psig) or more typically about 6.9 to about 11.0 MPa (gauge) (1000 to 1600 psig), a liquid hourly space velocity (LHSV) from about 0.5 to about 2 hr −1 and preferably about 0.7 to about 1.5 hr −1 and a hydrogen rate of about 421 to about 1,685 Nm 3 /m 3 oil (2,500-10,000 scf/bbl).
[0046] A hydrocracking effluent exits the hydrocracking reactor 36 in line 38 . The hydrocracking effluent in line 38 is heat exchanged with the hydrocracking feed in line 34 and in an embodiment may be cooled before entering a cold separator 40 . The cold separator 40 is in downstream communication with the hydrocracking reactor 36 . The cold separator may be operated at about 46° to about 63° C. (115° to 145° F.) and just below the pressure of the hydrocracking reactor 36 accounting for pressure drop to keep hydrogen and light gases in the overhead and normally liquid hydrocarbons in the bottoms. The cold separator 40 provides a vaporous hydrocracking effluent stream comprising hydrogen in an overhead line 42 and a liquid hydrocracking effluent stream in a bottoms line 44 . The cold separator also has a boot for collecting an aqueous phase in line 46 .
[0047] The vaporous hydrocracking effluent stream in line 42 may be compressed in a recycle gas compressor 50 to provide a recycle hydrogen stream in line 52 which is a compressed vaporous hydrocracking effluent stream. The recycle gas compressor 50 may be in downstream communication with the hydrocracking reactor 36 . A split 54 on the recycle hydrogen line 52 provides the first recycle hydrogen split stream in line 28 in upstream communication with the hydrocracking reactor 36 and a second recycle hydrogen split stream in line 56 in upstream communication with a hydrotreating reactor 92 .
[0048] As previously explained, in an embodiment, the first recycle split stream in line 28 may join with compressed make-up hydrogen stream in line 26 downstream of the recycle gas compressor 50 . However, if the pressure of the recycle hydrogen stream in line 52 is too great to admit the make-up hydrogen stream without adding more compressors on the make-up hydrogen line 20 , the make-up hydrogen stream may be added to the vaporous hydrocracking effluent stream in line 42 upstream of the recycle gas compressor 50 . However, this would increase the duty on the recycle gas compressor 50 due to greater throughput.
[0049] It is also preferred that the compressed make-up hydrogen stream in line 26 join the recycle gas stream downstream of the split 54 , so the make-up hydrogen will be directed to supplying the hydrogen requirements to the hydrocracking reactor 36 not filled by the recycle hydrogen stream in line 52 . It is contemplated that the compressed make-up hydrogen stream in line 26 will join the recycle gas stream upstream of the split 54 , but this would allow make-up gas to go to the hydrotreating unit 14 as well as to the hydrocracking unit 12 . The hydrocarbon feed to the hydrocracking reactor 36 will have much higher coke precursors than the feed to the hydrotreating unit 14 . Hence, using the make-up hydrogen to increase the hydrogen partial pressure in the hydrocracking reactor 36 will enable the catalyst in the hydrocracking reactor to endure more heartily the more deleterious components in the feed. It is also contemplated, but not preferred, that at least a portion of the compressed make-up hydrogen stream in line 26 will travel through line 28 to the split 54 and be mixed with recycle gas stream in line 52 and supply make-up gas to the hydrotreating unit 14 as well as to the hydrocracking unit 12 .
[0050] At least a portion of the hydrocracking effluent stream 38 may be fractionated in a fractionation section 16 in downstream communication with the hydrocracking reactor 36 to produce a diesel stream in line 86 . In an aspect, the liquid hydrocracking effluent stream 44 may be fractionated in the fractionation section 16 . In a further aspect, the fractionation section 16 may include a cold flash drum 48 . The liquid hydrocracking effluent stream 44 may be flashed in the cold flash drum 48 which may be operated at the same temperature as the cold separator 40 but at a lower pressure of between about 1.4 MPa and about 3.1 MPa (gauge) (200-450 psig) to provide a light liquid stream in a bottoms line 62 from the liquid hydrocracking effluent stream and a light ends stream in an overhead line 64 . The aqueous stream in line 46 from the boot of the cold separator may also be directed to the cold flash drum 48 . A flash aqueous stream is removed from a boot in the cold flash drum 48 in line 66 . The light liquid stream in bottoms line 62 may be further fractionated in the fractionation section 16 .
[0051] The fractionation section 16 may include a stripping column 70 and a fractionation column 80 . The light liquid stream in bottoms line 62 may be heated and fed to the stripping column 70 . The light liquid stream which is liquid hydrocracking effluent may be stripped with steam from line 72 to provide a light ends stream of hydrogen, hydrogen sulfide, steam and other gases in an overhead line 74 . A portion of the light ends stream may be condensed and refluxed to the stripper column 70 . The stripping column 70 may be operated with a bottoms temperature between about 232° and about 288° C. (450° to 550° F.) and an overhead pressure of about 690 to about 1034 kPa (gauge) (100 to 150 psig). A hydrocracked bottoms stream in line 76 may be heated in a fired heater and fed to the fractionation column 80 .
[0052] The fractionation column 80 may also strip the hydrocracked bottoms with steam from line 82 to provide an overhead naphtha stream in line 84 , a diesel stream in line 86 from a side cut and an unconverted oil stream in line 88 which may be suitable for further processing, such as in an FCC unit. The overhead naphtha stream in line 84 may require further processing before blending in the gasoline pool. It will usually require catalytic reforming to improve the octane number. The reforming catalyst will often require the overhead naphtha to be further desulfurized in a naphtha hydrotreater prior to reforming. In an aspect, the hydrocracked naphtha may be desulfurized in an integrated hydrotreater 92 . It is also contemplated that a further side cut be taken to provide a separate light diesel or kerosene stream taken above a heavy diesel stream taken in line 86 . A portion of the overhead naphtha stream in line 84 may be condensed and refluxed to the fractionation column 80 . The fractionation column 80 may be operated with a bottoms temperature between about 288° and about 385° C. (550° to 725° F.), preferably between about 315° and about 357° C. (600° to 675° F.) and at or near atmospheric pressure. A portion of the hydrocracked bottoms may be reboiled and returned to the fractionation column 80 instead of using steam stripping.
[0053] The diesel stream in line 86 is reduced in sulfur content but may not meet a low sulfur diesel (LSD) specification which is less than 50 wppm sulfur, an ULSD specification which is less than 10 wppm sulfur, or other specifications. Hence, it must be further finished in the diesel hydrotreating unit 14 .
[0054] The diesel stream in line 86 may be joined by the second recycle hydrogen split stream in line 56 to provide a hydrotreating feed stream 90 . The diesel stream in line 86 may also be mixed with a co-feed that is not shown. The hydrotreating feed stream 90 may be heat exchanged with the hydrotreating effluent in line 94 , further heated in a fired heater and directed to a hydrotreating reactor 92 . Consequently, the hydrotreating reactor is in downstream communication with the fractionation section 16 , the recycle hydrogen line 52 and the hydrocracking reactor 36 . In the hydrotreating reactor 92 , the diesel stream is hydrotreated in the presence of a hydrotreating hydrogen stream and hydrotreating catalyst to provide a hydrotreating effluent stream 94 . In an aspect, all of the hydrotreating hydrogen stream is provided from the recycle hydrogen stream in line 52 via second recycle hydrogen split stream 56 .
[0055] The hydrotreating reactor 92 may comprise more than one vessel and multiple beds of catalyst. The hydrotreating reactor 92 in FIG. 1 has two beds in one reactor vessel. In the hydrotreating reactor, hydrocarbons with heteroatoms are further demetallized, desulfurized and denitrogenated. The hydrotreating reactor may also contain hydrotreating catalyst that is suited for saturating aromatics, hydrodewaxing and hydroisomerization.
[0056] If the hydrocracking reactor 36 is operated as a mild hydrocracking reactor, the hydrocracking reactor may operate to convert up to about 20-60 vol-% of feed boiling above diesel boiling range to product boiling in the diesel boiling range. Consequently, the hydrotreating reactor 92 should have very low conversion and is primarily for desulfurization if integrated with a mild hydrocracking reactor 36 to meet fuel specifications such as qualifying as ULSD.
[0057] Hydrotreating is a process wherein hydrogen gas is contacted with hydrocarbon in the presence of suitable catalysts which are primarily active for the removal of heteroatoms, such as sulfur, nitrogen and metals from the hydrocarbon feedstock. In hydrotreating, hydrocarbons with double and triple bonds may be saturated. Aromatics may also be saturated. Some hydrotreating processes are specifically designed to saturate aromatics. Cloud point of the hydrotreated product may also be reduced. Suitable hydrotreating catalysts for use in the present invention are any known conventional hydrotreating catalysts and include those which are comprised of at least one Group VIII metal, preferably iron, cobalt and nickel, more preferably cobalt and/or nickel and at least one Group VI metal, preferably molybdenum and tungsten, on a high surface area support material, preferably alumina. Other suitable hydrotreating catalysts include zeolitic catalysts, as well as noble metal catalysts where the noble metal is selected from palladium and platinum. It is within the scope of the present invention that more than one type of hydrotreating catalyst be used in the same hydrotreating reactor 92 . The Group VIII metal is typically present in an amount ranging from about 2 to about 20 wt-%, preferably from about 4 to about 12 wt-%. The Group VI metal will typically be present in an amount ranging from about 1 to about 25 wt-%, preferably from about 2 to about 25 wt-%.
[0058] Preferred hydrotreating reaction conditions include a temperature from about 290° C. (550° F.) to about 455° C. (850° F.), suitably 316° C. (600° F.) to about 427° C. (800° F.) and preferably 343° C. (650° F.) to about 399° C. (750° F.), a pressure from about 4.1 MPa (600 psig), preferably 6.2 MPa (900 psig) to about 13.1 MPa (1900 psig), a liquid hourly space velocity of the fresh hydrocarbonaceous feedstock from about 0.5 hr −1 to about 4 hr −1 , preferably from about 1.5 to about 3.5 hr −1 , and a hydrogen rate of about 168 to about 1,011 Nm 3 /m 3 oil (1,000-6,000 scf/bbl), preferably about 168 to about 674 Nm 3 /m 3 oil (1,000-4,000 scf/bbl) for diesel feed, with a hydrotreating catalyst or a combination of hydrotreating catalysts. The hydrotreating unit 14 is integrated with the hydrocracking unit 12 , so they both operate at about the same pressure accounting for normal pressure drop.
[0059] The hydrotreating effluent stream in line 94 may be heat exchanged with the hydrotreating feed stream in line 90 . The hydrotreating effluent stream in line 94 may be separated in a warm separator 96 to provide a vaporous hydrotreating effluent stream comprising hydrogen in an overhead line 98 and a liquid hydrotreating effluent stream in a bottoms line 100 . The vaporous hydrotreating effluent stream comprising hydrogen may be mixed with the hydrocracking effluent stream in line 38 perhaps prior to cooling and enter into the cold separator 40 . The warm separator 96 may be operated between about 149° and about 260° C. (300° to 500° F.). The pressure of the warm separator 96 is just below the pressure of the hydrotreating reactor 96 accounting for pressure drop. The warm separator may be operated to obtain at least 90 wt-% diesel and preferably at least 93 wt-% diesel in the liquid stream in line 100 . All of the other hydrocarbons and gases go up in the vaporous hydrotreating effluent stream in line 98 which joins the hydrocracking effluent in line 38 and may be processed after heating therewith first by entering the cold separator 40 . Consequently, the cold separator 40 and, thereby, the recycle gas compressor 50 are in downstream communication with the warm separator overhead line 98 . Accordingly, recycle gas loops from both the hydrocracking section 12 and the hydrotreating section 14 share the same recycle gas compressor 50 .
[0060] The liquid hydrotreating effluent stream in line 100 may be fractionated in a hydrotreating stripper column 102 . In an aspect, fractionation of the liquid hydrotreating effluent stream in line 100 may include flashing it in a warm flash drum 104 which may be operated at the same temperature as the warm separator 96 but at a lower pressure of between about 1.4 MPa and about 3.1 MPa (gauge) (200-450 psig). A warm flash overhead stream in line 106 may be joined to the liquid hydrocracking effluent stream in bottoms line 44 for further fractionation therewith. The warm flash bottoms stream in line 108 may be heated and fed to the stripper column 102 . The warm flash bottoms may be stripped in the stripper column 102 with steam from line 110 to provide a naphtha and light ends stream in overhead line 112 . The naphtha and light ends stream in line 112 may be fed to the fractionation section 16 and specifically to the stripping column 70 at an elevation above the feed point of light liquid stream in line 62 . A product diesel stream is recovered in bottoms line 114 comprising less than 50 wppm sulfur qualifying it as LSD and preferably less than 10 wppm sulfur qualifying it as ULSD. It is contemplated that the stripper column 102 may be operated as a fractionation column with a reboiler instead of with stripping steam.
[0061] By operating the warm separator 96 at elevated temperature to reject most hydrocarbons lighter than diesel, the hydrotreating stripping column 102 may be operated more simply because it is not relied upon to separate naphtha from lighter components and because there is very little naphtha to separate from the diesel. Moreover, the warm separator 96 makes sharing of a cold separator 40 with the hydrocracking reactor 36 possible and heat useful for fractionation in the stripper column 102 is retained in the hydrotreating liquid effluent.
[0062] FIG. 2 illustrates an embodiment of a process and apparatus 8 ′ that utilizes a hot separator 120 to initially separate the hydrocracking effluent in line 38 ′. Many of the elements in FIG. 2 have the same configuration as in FIG. 1 and bear the same reference number. Elements in FIG. 2 that correspond to elements in FIG. 1 but have a different configuration bear the same reference numeral as in FIG. 1 but are marked with a prime symbol (′).
[0063] The hot separator 120 in the hydrocracking section 12 ′ is in downstream communication with the hydrocracking reactor 36 and provides a vaporous hydrocarbonaceous stream in an overhead line 122 and a liquid hydrocarbonaceous stream in a bottoms line 124 . The hot separator 120 operates at about 177° to about 343° C. (350° to 650° F.) and preferably operates at about 232° to about 288° C. (450° to 550° F.). The hot separator may be operated at a slightly lower pressure than the hydrocracking reactor 36 accounting for pressure drop. The vaporous hydrocarbonaceous stream in line 122 may be joined by the vaporous hydrotreating effluent stream in line 98 ′ from the hydrotreating section 14 ′ and be mixed and transported together in line 126 . The mixed stream in line 126 may be cooled before entering the cold separator 40 . Consequently, the vaporous hydrocracking effluent may be separated along with the vaporous hydrotreating effluent stream in the cold separator 40 to provide the vaporous hydrocracking effluent comprising hydrogen in line 42 and the liquid hydrocracking effluent in line 44 and which are processed as previously described with respect to FIG. 1 . The cold separator 40 , therefore, is in downstream communication with the overhead line 122 of the hot separator 120 and an overhead line 98 ′ of the warm separator 96 .
[0064] The liquid hydrocarbonaceous stream in bottoms line 124 may be fractionated in the fractionation section 16 ′. In an aspect, the liquid hydrocarbonaceous stream in line 124 may be flashed in a hot flash drum 130 to provide a light ends stream in an overhead line 132 and a heavy liquid stream in a bottoms line 134 . The hot flash drum 130 may be operated at the same temperature as the hot separator 120 but at a lower pressure of between about 1.4 MPa and about 3.1 MPa (gauge) (200 to 450 psig). The heavy liquid stream in bottoms line 134 may be further fractionated in the fractionation section 16 ′. In an aspect, the heavy liquid stream in line 134 may be introduced into the stripping column 70 at a lower elevation than the feed point light liquid stream in line 62 .
[0065] The rest of the embodiment in FIG. 2 may be the same as described for FIG. 1 with the previous noted exceptions.
[0066] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention.
[0067] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
[0068] In the foregoing, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated. Pressures are given at the vessel outlet and particularly at the vapor outlet in vessels with multiple outlets.
[0069] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
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An apparatus is disclosed for hydrocracking hydrocarbon feed in a hydrocracking unit and hydrotreating a diesel product from the hydrocracking unit in a hydrotreating unit. The hydrocracking unit and the hydrotreating unit shares the same recycle gas compressor. A warm separator separates recycle gas and hydrocarbons from diesel in the hydrotreating effluent, so fraction of the diesel is relatively simple. The warm separator also keeps the diesel product separate from the more sulfurous diesel in the hydrocracking effluent, and still retains heat needed for fractionation of lighter components from the low sulfur diesel product.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] Pursuant to 35 U.S.C. §119(a), this application claims the benefit of the Korean Patent Application No. 10-2011-0131006 filed on Dec. 8, 2011, Korean Patent Application No. 10-2011-0137562 filed on Dec. 19, 2011, Korean Patent Application No. 10-2012-0001670 filed on Jan. 5, 2012, all of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] This application relates to a filter guide having a securing member that is configured to secure a filter cover in a closed position in order to prevent foreign substances from moving past the filter cover for safety, and a clothes-drying machine using the same.
BACKGROUND
[0003] Generally, a clothes-drying machine is an electric appliance that evaporates water elements of washed clothes loaded into a drum (or a tub) thereof by supplying heated air to a drum to dry washed clothes.
[0004] The air exhausted from such a clothes-drying machine after evaporating moisture of washed clothes loaded in the drum may have the moisture of the washed-clothes inside. Such air becomes high temperature humid air. Drying machines can generally be classified based on the method of treating this high temperature humid air.
[0005] In other words, drying machines are classified into condensation-type drying machine and exhaustion-type drying machines. In a condensation type drying machine, high temperature humid air is heat-exchanged in a heat exchanger while circulated, without being exhausted outside, and the moisture contained in the high temperature humid air is condensed. In an exhaustion type drying machine, the high temperature humid air exhausted after passing through the drum is directly exhausted.
[0006] Meanwhile, the air exhausted from the drum after drying clothes can have foreign substances of the clothes such as lint. Such foreign substances can damage mechanical parts provided in the clothes-drying machine while passing through the mechanical parts or they may contaminate external air when exhausted outside. Accordingly, the air having passed the drum should also pass through a filter to remove the foreign substances therefrom.
[0007] Typically, such a filter is provided in a front portion of a drum to filter foreign substances contained in the air having passed a drum. When the clothes-drying machine is continuously used, foreign substances, such as lint, can be filtered by the filter.
[0008] Such a filter can interfere with the air flow if foreign substances like lint are filtered beyond a preset level. The filtered foreign substances have to be removed regularly from the filter. For such filter cleaning, a user separates the filter from the clothes-drying machine and removes foreign substances after a drying cycle or in a state where the operation of the drying machine is paused. After that, the user can mount the filter to the clothes-drying machine again.
[0009] Accordingly, the filter provided in the clothes-drying machine is configured of a filter assembly positioned under an introduction opening of the clothes-drying machine. The filter is inserted in a filter guide having an open top. When trying to exchange the filter assembly, the filter assembly is demounted from the filter guide to be cleaned. The clean filter assembly is inserted or a new filter assembly is inserted.
[0010] The filter guide has an open top to insert the filter assembly therein. In a state where the filter assembly is not inserted in the open top of the filter guide, a filter cover is provided in the filter guide to prevent foreign substances from coming into a duct.
[0011] In this instance, such a filter cover typically has a structure configured to be open by a force pushing the filter assembly when the filter assembly is inserted. Accordingly, in a state where the filter assembly is demounted, the filter cover maintains a closed state by using, for example, an auxiliary spring.
SUMMARY
[0012] According to one aspect, a clothes-drying machine includes a drum defining a cavity that receives clothes to be dried by the clothes-drying machine, a cabinet that houses the drum and that defines an opening to enable loading of clothes into the drum and unloading of clothes from the drum, a door configured to open and close to enable and inhibit access to the opening, a filter assembly configured to filter foreign substances included in air exhausted from the drum, and a filter guide positioned at a portion of the cabinet that defines the opening and defining a conduit that receives at least a portion of the filter assembly. The filter guide includes a sensing mechanism configured to detect a presence of the filter assembly in the conduit, a filter cover positioned within the conduit defined by the filter guide and separated from the portion of the cabinet that defines the opening, and a securing member configured to secure the filter cover in the closed position and allow the filter cover to move to an open position based on the sensing mechanism detecting the presence of the filter assembly in the conduit. The filter cover is configured to prevent items from moving past the filter cover in the conduit when in a closed position.
[0013] Implementations of this aspect may include one or more of the following features. For example, the sensing mechanism may include a latch sensor or a latch trigger and the securing member comprises a latch. The sensing mechanism may be attached to the securing member. The sensing mechanism may be configured to detect an absence of the filter assembly in the conduit. The securing member may secure the filter cover in the closed position based on the sensing mechanism detecting the absence of the filter assembly in the conduit. The filter cover may include a filter hinge shaft projecting outward from opposite sides of the filter cover and configured to be rotatably coupled within a hinge shaft hole of the filter guide, and a latching part configured to be engaged by the securing member based on the securing member securing the filter cover in the closed position.
[0014] The filter cover may be configured to hingedly rotate about the hinge shaft hole to move up and down between the closed and open positions. The clothes-drying machine may further include a support part extending between the sensing mechanism and the securing member. The securing member may include a latching hook configured to engage the latching part in order to maintain the filter cover in the closed position based on the filter assembly being positioned outside of the conduit. The sensing mechanism may include a pressing projection configured to be pressed by the filter assembly based on the filter assembly being inserted into the conduit. The filter guide may include a pressing opening configured to allow at least a portion of the pressing projection to pass through, and a hook opening configured to allow at least a portion of the latching hook to pass through.
[0015] According to another aspect, a filter guide defines a conduit and is configured to receives a filter assembly. The filter guide includes a latch member coupled to the filter guide, and a filter cover positioned within the conduit and configured to move back and forth between an open position and a closed position. The filter cover is configured to prevent items from moving past the filter cover when in the closed position. The latch member maintains the filter cover in the closed position based on the filter assembly being located outside of the filter guide. The latch member enables the filter cover to move to the open position based on the filter assembly being inserted into the filter guide to a position that causes release of the latch member.
[0016] Implementations of this aspect may include one or more of the following features. For example, the latch member may be configured to rotate outward with respect to the filter cover based on the filter assembly being inserted into the filter guide to a position that causes release of the latch member. The latch member may include a body portion having an upper end that is rotatably coupled to the filter guide, a pressing projection positioned at an upper portion of the body portion and configured to be pressed by the filter assembly, and a latching hook positioned at a lower portion of the body portion and configured to maintain the filter cover in the closed position by supporting a bottom surface of the filter cover. The pressing projection may include an inclined surface that is inclined in a downward direction with respect to an inserting direction of the filter assembly. A bottom side of the latching hook may include an inclined surface that is inclined in an upward direction with respect to a rotating direction of the filter guide as it moves from the open position to the closed position. The latch member may further include a hinge shaft positioned at the upper end of the body portion, and the filter guide may include a coupling hole to rotatably couple the hinge shaft therein. The filter guide may include a pressing opening configured to allow at least a portion of the pressing projection to pass through, and a hook opening configured to allow at least a portion of the latching hook to pass through. The filter guide may include a front member having a front side wall and a rear member having a rear side wall. The front and rear members may be assembled together. The pressing opening may be defined in the front side wall of the front member, and the hook opening may be defined in the rear side wall of the rear member. The latch member may be one of a pair of latch members provided on opposite sides of the filter guide. The filter cover may include a latching part configured to be engaged by the latch member based on the latch member maintaining the filter cover in the closed position. The filter cover may include filter hinge shafts projecting outward from opposite sides of the filter cover. A side wall of the filter guide includes a hinge shaft hole configured to rotatably couple the filter hinge shaft therein. The clothes-drying machine may further include a torsion spring positioned between the filter hinge shaft of the filter cover and the hinge shaft hole of the filter guide and configured to provide an elastic restitution force to the filter cover in a direction opposite of an inserting direction of the filter assembly.
[0017] According to another aspect, a clothes-drying machine includes a drum defining a cavity that receives clothes to be dried by the clothes-drying machine, a cabinet that houses the drum and that defines an opening to enable loading of clothes into the drum and unloading of clothes from the drum, a door configured to open and close to enable and inhibit access to the opening, a filter assembly configured to filter foreign substances included in air exhausted from the drum, and a filter guide positioned at a portion of the cabinet that defines the opening and defining a conduit that receives at least a portion of the filter assembly. The filter guide includes a filter cover positioned within the conduit and configured to move back and forth between an open position and a closed position, a pair of latch members provided on opposite sides of the filter guide, and a latching hook configured to maintain the filter cover in the closed position by supporting a bottom surface of the filter cover. The filter cover is configured to prevent items from moving past the filter cover when in the closed position. Each of the pair of latch members has a pressing projection configured to be pressed by the filter assembly. The pair of latch member maintains the filter cover in the closed position based on the filter assembly being located outside of the filter guide. The pair of latch member enables the filter cover to move to the open position based on the filter assembly being inserted into the filter guide and pressing the pressing projection of each of the pair of latch members. Pressing the pressing projection causes the latching hook to disengage from the filter cover.
[0018] It is to be understood that both the foregoing general description and the following detailed are exemplary and explanatory.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, serving together with the description to explain various aspects of technology. In the drawings:
[0020] FIG. 1 is a schematic diagram of a clothes-drying.
[0021] FIG. 2 is an exploded perspective view illustrating a coupling state of a filter guide provided in the clothes-drying machine.
[0022] FIG. 3 is a perspective view illustrating a latch member coupled to the filter guide.
[0023] FIG. 4 is a perspective view illustrating a closed state of a filter cover provided in the filter guide.
[0024] FIG. 5 is a specific perspective view illustrating the latch member provided in the filter guide.
[0025] FIG. 6 is a sectional view illustrating a closed state of the filter cover provided in the filter guide;
[0026] FIG. 7 is a perspective view illustrating an open state of the filter cover provided in the filter guide.
[0027] FIG. 8 is a diagram illustrating an inserted state of a filter assembly with respect to the filter guide.
[0028] FIG. 9 is an enlarged sectional diagram illustrating an operation of the latch member when the filter assembly is inserted in the filter guide.
[0029] FIG. 10 is a sectional diagram illustrating an open state of the filter cover provided in the filter guide.
DETAILED DESCRIPTION
[0030] Referring to the accompanying drawings, a filter guide having a latch device for a filter cover and a clothes-drying machine using the same will be described in detail as follows.
[0031] Reference will now be made in detail to various specific implementations and examples, illustrations of which are provided in the accompanying drawings. In general, the same reference numbers are used throughout the drawings to refer to the same or like parts.
[0032] This application relates to a filter guide having a filter assembly of a clothes-drying machine mounted thereto. Accordingly, detailed descriptions of structural parts other than the filter guide will be omitted.
[0033] Referring to the accompanying drawings, a clothes-drying machine according to this application will be described. FIG. 1 is a diagram schematically illustrating a clothes-drying machine according to one implementation.
[0034] As shown in FIG. 1 , a clothes-drying machine A according to one implementation includes a cabinet 1 having a door 3 coupled to a front surface thereof and a drum 6 rotatably mounted in the cabinet 1 , with a plurality of lifters (not shown) projected from an inner circumferential surface thereof. In addition, the clothes-drying machine includes a control panel 2 provided in a front surface of the cabinet. A display window and an operational button are provided in the control panel 2 .
[0035] A circulation duct (not shown) is in communication with the drum 6 rotatable in the cabinet 1 by a drive-motor. Heated air is exhausted from the drum via the circulation duct in communication with a rear portion of the drum 6 to dry washed-clothes that are drying objects.
[0036] The air used in drying the clothes contains the moisture evaporated from the clothes to become humid air. The humid air is supplied to a filter entrance provided adjacent to an opening 5 of the cabinet in front of the front surface of the drum to pass a filter. Foreign substances that could be contained by the humid air may be filtered by the filter provided between a front portion of the drum and the circulation duct. Such air flow can be performed by a fan (not shown) provided in the circulation duct more efficiently.
[0037] Meanwhile, a heat exchanger for heat-exchanging with air circulating the circulation duct may be provided in the clothes-drying machine. The heat exchanger heat-exchanges with the circulating air and absorbs heat from the high temperature humid air. After that, the air condenses and removes the moisture contained in the high temperature humid air.
[0038] The dry air having the moisture removed there from is re-heated by the heat exchanger or a heater, to become a high temperature dry air. The high temperature dry air is re-supplied to the drum 6 along the circulation duct.
[0039] Referring to FIG. 2 , a filter guide having a latch device for a filter cover and the clothes-drying device using the filter guide will be described in detail as follows. FIG. 2 is an exploded perspective view illustrating a coupling state of the filter guide.
[0040] Referring to FIG. 2 , the drying machine according to one implementation may include a filter guide 30 having a filter assembly 70 configured to filter foreign substances contained in the air exhausted from the drum 6 . The filer guide 30 can define a conduit that receives at least a portion of the filter assembly.
[0041] The filter guide 30 can be a member that forms a filter entrance 6 configured to insert the filter assembly ( 70 , see FIG. 8 ) therein and the filter guide is provided under the opening 5 , with an open top (see FIG. 1 ). When the filter assembly 70 is not inserted in the filter guide 30 , the open top of the filter guide 20 is closed by the filter cover 10 such that items are prevent from moving past the filter cover.
[0042] The filter guide 30 can include a front member 30 a and a rear member 30 b that are assembled to each other. The front member 30 a consists of a front plate 31 a for defining a front surface and a front side wall 32 a for defining a side wall. The rear member 30 b consists of a rear plate 31 b for defining a rear wall and a rear side wall 32 b defining a side wall.
[0043] The filter guide 30 includes a filter cover that can be closed depending on the insertion of the filter assembly 70 , a torsion spring 50 rotatable in a closing direction of the filter guide 30 when the filter assembly 70 is separated from the filter guide, and a latch device for the filter cover that limits the rotation of the filter cover 10 when the filter assembly 70 is separated from the filter guide 30 and releases the limitation on the filter cover 10 when the filter assembly 70 is inserted in the filter guide, thus making the filter cover rotatable.
[0044] Further, a hinge shaft hole is defined in each of lower portions of the filter guide 30 to have the filter cover 10 rotatably coupled thereto by a hinge. A latch member coupling hole 37 is define in each of upper portions of the filter guide 30 to rotatably support the latch member 100 of the filter cover latch device as will be described later. In this instance, the coupling state of the filter cover 10 and the installation state of the latch member 10 will be described in detail when the filter cover 10 and the latch member 100 are described.
[0045] The filter cover 10 typically has the structure configured to close the open top portion of the filter guide 30 . In other words, when the filter assembly 70 is inserted in the filter guide 30 , the filter cover is naturally open by the force generated by the inserted filter assembly 70 . When the filter assembly 70 is separated, the filter cover is closed by auxiliary spring such as the torsion spring 50 , without an additional external force. Also, the opening of the filter cover 10 is limited by the latch device for the filter cover, when the filter assembly 70 is separated.
[0046] In addition, the filter cover can hingedly rotate toward a rear side wall from the inside of the filter guide 30 . Accordingly, the filter cover 10 includes a filter hinge shaft 14 projected from each of opposite sides. Such a filter hinge shaft 14 is inserted in hinge shaft holes 34 provided in both lateral walls of the filter guide 30 and hingedly rotates on the hinge shaft hole, to open and close the open top of the filter guide 30 .
[0047] The torsion spring 50 may be further provided in the hinge shaft hole 34 of the filter guide 30 to apply an elastic restitution force to the filter cover to make the filter cover 10 maintain the closed state. Accordingly, the filter cover 10 is lifted by the elastic restitution force of the torsion spring 50 to maintain the closed state, in a state where the filter assembly 70 is not inserted, and it hingedly rotates downwardly to maintain the open state, in a state where the filter assembly 70 is inserted.
[0048] A latching part 13 is formed in each sides of the filter cover 10 . As shown in FIG. 2 , latching parts 13 are formed in both sides of the filter cover 10 , to lock the filter cover from being open downwardly in the latch device for the filter cover.
[0049] The latch device for the filter cover is installed in each inner surface of the filter guide 30 . Preferably, the latch devices are installed adjacent to the opposite filter hinge shafts 14 having the filter cover 10 hingedly coupled thereto, respectively. Such latch device for the filter cover may be formed by a pair of latch members 100 . Such a pair of latch members 100 may be installed in opposite to both sides of the filter guide 30 . Accordingly, only one of the latch members 100 will be described and description of the other one will be omitted.
[0050] Referring to the accompanying drawings, the latch device for the filter cover will be described in detail as follows. FIG. 3 is a perspective view illustrating the latch member coupled to the filter guide.
[0051] As shown in FIG. 3 , the latch member 100 composing the latch device for the filter cover includes a body part 110 formed of a plastic material extended in a vertical direction, with good ductility. A hinge shaft 170 is formed in a top of the body part 110 to be rotatably inserted in the latch member coupling hole 37 formed in the filter guide 30 . A pressing projection 130 is formed in a lower portion of the hinge shaft 170 and the pressing projected part can be pressed by the filter assembly 70 when the filter assembly 70 is inserted. A latching hook 150 is formed in a lower portion of the body part 110 to support a lower portion of the filter cover 10 when the filter cover 10 is closed. The pressing projection 130 may be one type of a sensing mechanism that is configured to detect a presence and/or absence of the filter assembly in the conduit. Other types of sensing mechanisms may be used. In some cases, the sensing mechanism may be a latch sensor or a latch trigger. The latching hook 150 may be one type of a securing member that is configured to secure the filter cover in the closed position. Other types of securing members may be used. In some cases, the sensing mechanism may be attached to the securing member via the body part 110 .
[0052] As illustrated in FIGS. 3 and 4 , the pressing projection 130 and the latching hook 150 are projected into the filter guide 30 as they are assembled from the outside of the filter guide 30 . To achieve this, a pressing opening 33 and a hook opening 35 may be defined in the filter guide 30 to expose the pressing projection and the latching hook 150 . The pressing opening 33 may be positioned in an upper portion of an inner side wall composing the filter guide 30 and the hook opening 35 may be positioned in a lower portion of the inner side wall.
[0053] In other words, the latch members 100 can be installed in both outer portions of the filter guide 30 as shown in FIG. 2 . The pressing projection 130 and the latching hook 150 may be projected from the side wall of the filter guide 30 .
[0054] Accordingly, when the filter assembly 70 is inserted, the pressing projection 130 projected from each of the opposite inner walls composing the filter guide is pressed by the side wall of the filter assembly 70 in close contact. Subsequently, the latch member 100 rotates outwardly with respect to the filter assembly 70 along the hinge shaft 170 and the latching hook 150 positioned in the lower portion of the latch member 100 rotates outwardly with respect to the hook opening 35 , thereby releasing the supporting state of the filter cover 10 .
[0055] The operation of the filter guide having the latch device for the filter will be described as the filter assembly is mounted or demounted as follows.
[0056] Referring to FIGS. 4 to 6 , the locking of the closed filter cover in the filter guide 30 will be described in detail as follows.
[0057] FIG. 4 is a perspective view illustrating the closed state of the filter cover provided in the filter guide. FIG. 5 is a specific perspective view illustrating the latch member provided in the filter guide. FIG. 6 is a sectional view illustrating the closed state of the filter cover provided in the filter guide.
[0058] Referring to FIGS. 4 to 6 , the closed state of the filter cover 10 is maintained in the filter guide 30 in a state where the filter assembly 70 is not inserted.
[0059] In other words, a top of the latching hook 150 composing the latch member 100 hooks the latching part 13 of the filter cover 10 thereto to locks the opening of the latch member. A bottom of the latching hook 150 is an inclined surface to restitute the latching part 13 of the filter cover 10 to the closed state by using the elastic restitution force of the torsion spring 50 as the filter assembly is separated.
[0060] Specifically, when the filter assembly 70 is separated, the filter cover 10 is closed as rotated by the elastic restitution force of the torsion spring 50 . Such an operation makes the latching part 13 of the filter cover 10 push the inclined surface formed in the bottom of the latching hook 150 upwardly to east the pressing part 13 of the filter cover 10 on a top surface of the latching hook 150 .
[0061] Especially, the latching part 13 of the filter cover 10 is not hingedly rotated in a downward direction even when it receives the force in a state of being hooked to the latching hook 150 of the latch member 100 as shown in FIG. 5 , such that the closing locked state of the filter cover may be maintained.
[0062] Accordingly, the filter cover 10 is closed in the open top space of the filter guide 30 as shown in FIG. 6 . Even when the filter cover 10 is pressed from the top, the latching part 13 is hooked to the latching hook 150 not to move downwardly. As a result, the filter cover 10 is not opened even if foreign substances having the weight larger than the elastic restitution force of the torsion spring 50 are introduced. Therefore, foreign substances can be prevented from coming into the filter cover 10 .
[0063] Referring to FIGS. 7 to 10 , the closing locked state of the filter cover provided in the filter guide 30 will be described in detail as follows.
[0064] FIG. 7 is a perspective view illustrating an open state of the filter cover provided in the filter guide. FIG. 8 is a diagram illustrating an inserted state of a filter assembly with respect to the filter guide. FIG. 9 is an enlarged sectional diagram illustrating an operation of the latch member when the filter assembly is inserted in the filter guide. FIG. 10 is a sectional diagram illustrating an open state of the filter cover provided in the filter guide.
[0065] As shown in FIGS. 7 and 8 , when the filter assembly 70 is inserted, the filter assembly 70 presses the pressing projection 130 toward the side wall thereof and the latching hook 150 is widened outwardly, thereby releasing the closing locked state of the latching part 13 provided in the filter cover 10 .
[0066] In other words, when the filter assembly 70 is inserted in the open top space of the filter guide 30 , both side walls of the filter assembly press the pressing projection 130 of the latch member 100 projected from both inner walls of the filter guide 30 .
[0067] After that, as shown in FIG. 9 , the body part 110 of the latch member 100 is pushed outwardly with respect to the hinge shaft 170 to separate the latching hook 150 from the latching part 13 . Accordingly, the closing locked state of the filter cover 10 may be released.
[0068] The filter cover 10 is pressed by the filter assembly 70 moving downwardly and the filter cover 10 is hingedly rotated in a downward direction to be open as shown in FIG. 10 , such that the filter assembly 70 may be completely inserted.
[0069] When the filter assembly 70 is separated, the filter cover 10 is hingedly rotated by the elastic restitution force of the torsion spring 50 in the reverse order described above, to be closed to close the open top space of the filter guide 30 . Together with the separation of the filter assembly 70 , the latch member 100 is hingedly rotated in an upward direction and it is latched to the latching part 13 of the filter cover 10 in a closed state.
[0070] The implementations described above are one of various exemplary implementations. This application is not limited by the implementations described above and the accompanying drawings. Various modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure. In addition to variations and modifications in the component parts and/or arrangements, alternative uses may also exist.
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A clothes-drying machine includes a drum defining a cavity that receives clothes, a cabinet that houses the drum and defines an opening to enable loading and unloading of clothes, a door configured to open and close to enable and inhibit access to the opening, a filter assembly configured to filter foreign substances included in air exhausted from the drum, and a filter guide positioned at a portion of the cabinet that defines the opening and defining a conduit that receives at least a portion of the filter assembly. The filter guide includes a sensing mechanism configured to detect presence of the filter assembly in the conduit, a filter cover positioned within the conduit, and a securing member configured to secure the filter cover and allow the filter cover to move to an open position based on the sensing mechanism detecting the presence of the filter assembly in the conduit.
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FIELD OF THE INVENTION
[0001] The ability to detect anti-HCV in oral fluid is useful for the rapid detection of HCV exposure by non-invasive means. The methods provided in the invention are also useful in the early detection of HCV infection by recognition of anti-HCV of the IgA class, monitoring of antiviral therapy, genotyping of HCV virus, determining immune response to individual HCV epitopes, and monitoring potential vaccination programs.
BACKGROUND OF THE INVENTION
[0002] Hepatitis C (HCV) is the major cause of parenterally transmitted non-A, non-B hepatitis (Choo et al., 1989 Science 244:359-362; Kuo et al., 1989, Science 244:362-364) with a prevalence of 1-3% throughout the world (Davis et al., 1998, Hepatology 28(Suppl 4, pt 2):99A). Chronic disease develops in 60-85% of patients, with cirrhosis representing a major hallmark of HCV infection. Among patients whose infection progresses to cirrhosis, as many as 1-4% develop hepatocellular carcinomas annually (Fattovich et al., 1997, Gastroenterology 112:463-472). It is estimated that the need for hepatic transplantation for infected individuals will increase 5-7 fold in the next 20 years unless more effective treatments and preventative programs are introduced (Davis et al., 1998, Hepatology 28 (Suppl 4, pt 2):99A).
[0003] While additional anti-viral therapies are needed to combat the spread of HCV, equally necessary is the development of a rapid, highly sensitive and cost-effective test to detect and monitor HCV within the population. Current PCR and ELISA-based assays for the detection of HCV are costly, relatively slow and reliant upon serum or plasma as the sample fluid. The substitution of oral fluid for serum in HCV assays would provide a cost-effective, non-invasive means to conduct routine screening and would facilitate sample procurement from patient groups where serum collection is difficult, such as intravenous drug users, who constitute a significant portion of total HCV cases.
[0004] A number of oral fluid-based assays have been designed for the detection of viral antibodies with good results. Virus-specific antibodies have been detected in the oral fluid of patients infected with human immunodeficiency virus (Major et al., 1991, J. Infect. Dis. 163:699-702), hepatitis A (Stuart et al., 1992, Epdiem. Infect. 109:161-166), hepatitis B (Ben Aryeh et al., 1985, Arch. Oral Biol. 30:97-99), rubella (Saleh, 1991, J. Egypt Public Health Assoc. 66:123-124,) and following immunization against polio (Zaman et al., 1991, Acta Paediatrica Scan. 80: 1166-1173), rotavirus (Ward et al., 1992, J. Med. Virol. 36: 222-225) and hepatitis A (Laufer et al., 1995, Clin. Infect. Dis. 20:868-871). For HCV, ELISA-based assays developed initially for use with serum or plasma have been modified to detect anti-HCV antibodies in oral fluid (Cameron et al., 1999, J. Viral Hepatitis 6:141-144; Elsana et al., 1998, J. Med. Virol 55:24-27; McIntyre et al., 1996, Eur. J. Clin. Microbiol. Infect. Dis. 15:882-884; Sherman et al., 1994, Amer. J. Gastroent 89:2025-2027; Thieme et al., 1992, J. Clin. Microbiol. 30:1076-1079); using a modified protocol with the HCV 3.0 ELISA (Ortho Diagnostic Systems), (McIntyre et al. 1996, Eur. J. Clin. Microbiol. Infect. Dis. 15:882-884) detected anti-HCV antibodies within a group of 18 HCV(+) and 49 HCV(−) oral fluid samples with 72% sensitivity and 98% specificity. In the same study, 100% sensitivity and 100% specificity was achieved using the Monolisa HCV assay (Sanofi Pasteur Diagnostics, France). It is unclear what the differences were that lead to the increased sensitivity of the Monolisa test, and thus care must be taken in the interpretation of results obtained from tests not designed specifically for use with oral fluid. None of these assays has achieved the sensitivity required for a rapid point of care test. None of these assays has disclosed the special role of oral fluid IgA in human oral fluid as a key determinant of sensitivity and specificity for HCV screening.
[0005] An intrinsic difficulty in designing oral fluid-based diagnostic assays, however, is detecting a sufficient proportion of the relatively low levels of antibody present in oral fluid to generate a meaningful diagnostic result. Indeed, it is estimated that overall antibody levels are 800-1000-fold lower in oral fluid than in serum (Parry et al., 1987, Lancet 2:72-75) making detection sensitivity of the utmost importance in oral fluid-based tests. While this problem is significant, an HCV assay designed to be used specifically with oral fluid as the diagnostic fluid, and not simply a serum-based assay modified for use with saliva, could overcome this complication and provide an important test for HCV in the population.
SUMMARY OF THE INVENTION
[0006] The invention disclosed is a means to detect antibodies against HCV using oral fluid as a sample medium. Assays in the prior art have not achieved the sensitivity and specificity required to rapidly screen HCV infection in human oral fluid. Most critically, the use of a labeled detection molecule that recognizes not only IgG, but all classes of immunoglobulins, enhances the ability to detect anti-HCV in oral fluid in an ELISA format or using a flow-through system. When detecting anti-HCV using a labeled detection molecule that recognizes only anti-HCV of the IgG class, detection sensitivity was vastly reduced. The incorporation of a detection method that labels multiple classes of anti-HCV, on the other hand, allows for increased detection sensitivity of samples that would otherwise be scored negative using a detection method that only recognizes IgG.
[0007] By coupling this detection method to an assay that utilizes a membrane with immobilized HCV peptide antigens present as a trapping zone, followed by subsequent flow of sample through the trapping zones and selective binding of labeled antibodies specific for HCV epitopes within the trapping zone, an immunoassay for the detection of anti-HCV can be performed in a short time period (<15 minutes). The ability to use oral fluid as a sample is of great value to such a rapid diagnostic tool since oral fluid can be collected rapidly and used immediately following collection. An assay using oral fluid, performed on a miniature test platform, analyzed in a small light gathering machine, and able to be completed within 15 minutes from start to finish would be of enormous value as a screening agent for HCV in the population. By decreasing the time of the assay and eliminating the need for invasive blood-based sample acquisition, such an assay would certainly increase the ability to screen, detect and monitor HCV within the population.
[0008] The use of an assay to detect anti-HCV in saliva would also be of benefit in the rapid and non-invasive detection of antibodies following vaccinations and monitoring of vaccination efficacy over time, monitoring therapeutic response of patients to treatment regimes and screening for early infection, as IgA antibodies are known to be an important part of the early stages of the immune response.
[0009] Thus, the present invention seeks to overcome the deficiencies of the prior technology by designing an HCV assay that would meet the following objectives. A first objective is that the test is non-invasive, generates minimal risk of infection to those administering the test and can be performed from start to finish by non-medical personnel.
[0010] A second objective is that the test is rapid (<15 min.).
[0011] A third objective is that the test is specialized to detect the specific class of anti-HCV antibodies in oral fluid, and is not simply a modification of a current serum-based assay.
[0012] A fourth objective is that the test incorporates a number of different HCV antigens to minimize false negative results.
[0013] A fifth objective is that the test is adaptable to future incarnations of the assay to meet specific diagnostic needs, and that it is sensitive enough to detect extremely low levels of anti-HCV.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 . Characterization of multiple classes of anti-HCV present in serum and oral fluid. Paired serum/oral fluid samples were screened by HCV 3.0 ELISA using enzyme-conjugated antibodies specific for human IgG, IgM or IgA, respectively. (A) In serum, high levels of anti-HCV IgG and IgM class antibodies are detectable, while relatively little anti-HCV IgA is present. (B) In oral fluid, the majority of antibodies detectable are of the IgG or IgA class with little or no anti-HCV IgM present.
[0015] FIG. 2 : Components of the HCV strip immunoassay. (A) Top view of disassembled assay cassette showing the position of the nitrocellulose test strip as well as the top and bottom wicks and the substrate-coated gelbond. The “trapping zone” is located directly beneath the substrate-coated gelbond. The trapping zone and substrate-coated gelbond are kept from contacting one another until such time as the cassette is inserted into the luminometer for reading. (B) Top view of an assembled cassette with the conjugate hinge in the open position. (C) Top view of an assembled cassette with the conjugate hinge in the closed position. Also visible in C is the chase injection port and the luminescence measuring window. (D) Side view of assembled cassette showing the conjugate hinge in the open position as well as the lever on the back of the cassette that is contacted by the Junior luminometer upon insertion to bring the anti-HCV/anti-human-AP complex captured in the trapping zone into contact with the substrate-coated gelbond suspended above and thus initiate the luminescence reaction.
[0016] FIG. 3 : Dose response curve for spiked monoclonal anti-HCV antibodies in an HCV(−) oral fluid sample. Monoclonal anti-HCV antibodies were spiked into an HCV(−) oral fluid sample to test the ability of the mixed antigen trap to capture anti-HCV antibodies. (A) Dose response curve for spiked monoclonal anti-HCV antibodies present in oral fluid at concentrations ranging from 0-117 μg/ml. (B) Digital photograph of nitrocellulose test strips post-stained with NBT/BCIPT corresponding to the data points in (A). Staining within coherent trapping zones is visible in all spiked samples while no staining is present in the non-spiked control.
[0017] FIG. 4 . Screening of 64 known HCV(+) saliva samples on strip immunoassay. A cutoff was determined using the mean of 14 HCV(−) saliva samples +2SD. 63/64 known HCV(+) saliva samples generated values above the calculated cutoff for a sensitivity of 98.4%.
[0018] FIG. 5 : Direct visualization of HCV LNSI assays using the NightOwl Molecular Light Imager. To observe the relative amounts of luminescence produced by highly immunoreactive oral fluid samples (HCV(++)), weakly reactive samples (HCV(+)) and HCV(−) samples, luminescence was collected (60 sec exposure time) by the NightOwl Molecular Light Imager. A luminescence intensity scale is provided for reference with purple representing the most intense regions of luminescence. (A) A highly immunoreactive oral fluid sample generated extensive luminescence within the collection window just below the closed conjugate hinge assembly. (B) A weakly immunoreactive oral fluid sample. (C) An HCV(−) oral fluid sample.
[0019] FIG. 6 . Antibody profile of 9 individual patient samples using a six-line peptide trapping zone. Patient samples were passed through six different antigen trapping zones to observe the immune response profile for these subjects. Strong responders had high levels of antibody binding against most of the six peptides while weak responders had lower levels of binding within the six trapping zones.
[0020] FIG. 7 Diagram of the steps of the process according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The invention described herein represents the ability to detect HCV exposure in oral fluid by labeling and detecting multiple classes of anti-HCV instead of anti-HCV IgG alone. Saliva is first collected by a device independent of the test module. A volume of crude saliva is then added to the test module wherein it mixes with a detection molecule that labels all classes of human antibodies. The antibody-detection molecule complex then passes through a trapping zone comprised of immobilized HCV peptide antigens. Antibody/detection molecule complexes that are recognize the HCV sequences represented in trapping zone bind and are thus immobilized within the zone ( FIG. 7 ). The addition of a suitable substrate for the detection molecule allows for generation of a signal in samples possessing antibodies to HCV and thus correlates with HCV exposure. In a particular embodiment the non-antibody label protein is protein LA conjugated to an enzyme which generates a chemiluminescent signal that is read in a luminometer.
EXAMPLES
[heading-0022] I. Detection of Multiple Classes of Anti-HCV in Oral Fluid to Increase Detection Sensitivity.
[0023] The detection of multiple classes of anti-HCV in oral fluid can increase the H detection sensitivity of the Ortho HCV 3.0 ELISA to levels comparable with those attained using serum samples. Patients for this study were pre-selected from one of eleven participating clinical sites and shown to be either HCV positive or negative based on a clinical diagnosis according to the CDC testing algorithm (Alter et al., 1998). Serum samples were further confirmed by repeat in-house testing using the Ortho HCV 3.0 ELISA following the manufacturer's instructions. Oral fluid samples were collected using a Salivette (Sarstedt Research, Germany) whereby a polyester-coated cotton plug is placed in the mouth of the patient until saturation and is then centrifuged in a carrier tube for 5 minutes to extract the oral fluid. The Salivette was chosen for its ease of use and because it does not use a sample buffer to dilute the specimens. Paired samples were shipped overnight at 4° C. and processed immediately upon arrival. Samples were then stored at −80° C. until testing.
[0024] To determine if specific classes of antibodies were preferentially enriched in serum or oral fluid samples, the composition of anti-HCV present in both fluids was examined. Fourteen paired HCV-positive oral fluid/serum samples (with sufficient volumes of oral fluid for multiple ELISA assays) were chosen for ELISA analysis and examined using secondary enzyme-conjugated antibodies (Jackson Immunoresearch) that recognize only IgG, IgM or IgA, respectively, to identify the different classes of anti-HCV detectable in oral fluid ( FIG. 1 ). Modification of the HCV 3.0 was necessary to achieve optimal detection sensitivity and specificity; compared to the manufacturer's instructions for use with serum, oral fluid sample volume was increased from 10 μl to 100 μl per well and sample incubation time was increased from 1 hour at 37° C. to overnight at 4° C. Furthermore, a more sensitive two-part TMB substrate kit (Pierce) was used for all testing in place of the o-phenylenediamine tablets supplied with the HCV 3.0 kit. Analysis of the optical densities (OD) generated by these 14 samples showed that anti-HCV of the IgG and IgM class was most abundant in serum samples (mean OD=1.85, 1.03, respectively), with little IgA class anti-HCV present (OD=0.24; FIG. 1A ). These samples were not treated for rheumatoid factor, however, and thus it is possible that elevated levels of anti-IgM reactivity in serum samples may be attributable to the presence of this interfering substance (see Genser et al., 2001). In contrast, while IgG (OD=1.10) remained the major class of anti-HCV detectable in oral fluid samples using the HCV 3.0 assay, a higher level of anti-HCV IgA (OD=0.42) was also detectable, while nearly no anti-HCV IgM was present (OD=0.02; FIG. 1B ). Statistically, the mean OD of anti-HCV of the IgG and IgM class is significantly reduced in oral fluid compared to serum (P<0.01), while the OD of IgA class anti-HCV is not significantly different (P>0.01).
[0025] Unexpectedly, in a number of oral fluid samples possessing low anti-HCV IgG levels, a significant amount of anti-HCV IgA was detectable ( FIG. 1B ) which might contribute to a higher overall OD and thus render a positive result. Indeed, the ability to detect anti-HCV of the IgA class may also increase the likelihood of detection early on during the course of infection, as IgA is known to be present during the earliest stages of the immune responses to infections. (Freihorst and Ogra, 2001).
[0026] An investigation was then conducted to determine whether the detection of multiple classes of anti-HCV antibodies, instead of IgG alone, could increase the sensitivity of the Ortho HCV 3.0 ELISA in a modified oral fluid-based format. Paired oral fluid/serum samples from 127 known HCV seropositive and 31 seronegative donors were screened using the HCV 3.0 assay according to the manufacturer's instructions using the monoclonal anti-human IgG-peroxidase detection antibody. Using serum samples, 100% sensitivity and specificity with the HCV 3.0 assay was achieved (Table I).
TABLE I Sensitivity and specificity of HCV 3.0 assay using paired serum/oral fluid samples with different enzyme- conjugated secondary antibodies. Serum Serum Oral fluid Positive Negative Oral fluid Positive Negative Positive 103 0 Positive 127 0 Negative 24 31 Negative 0 31 Conjugate: Monoclonal anti-human IgG Goat anti-human IgG + IgM + IgA Sensitivity: 81% 100% Specificity: 100% 100%
[0027] Because there is no accepted cutoff value for oral fluid in the HCV 3.0 kit, sensitivity and specificity were determined by ROC analysis at the 95% confidence interval as well as by determining a cutoff 3.5SD above the mean of the 31 HCV negative samples. Using the modified incubation protocol mentioned previously, along with the anti-IgG conjugate antibody of the HCV 3.0 kit, detection sensitivity was reduced to 81% (103/127) while specificity remained 100%.
[0028] Oral fluid samples were then re-screened using a 1:16,000 dilution of peroxidase-labeled goat anti-human IgG+IgM+IgA antibody cocktail (Kirkgaard and Perry Laboratories, Gaithersburg, MD) in PBS/1% BSA/10% goat serum instead of the monoclonal anti-human IgG provided with the HCV 3.0 kit. This antibody dilution proved to have the greatest signal:noise ratio in titration studies and was used in all studies in which the antibody cocktail was included. Using this modified protocol, anti-HCV was detected in patient oral fluid samples with 100% sensitivity and specificity by ROC analysis or using the calculated 3.5SD cutoff (cutoff=0.026; Table I). All oral fluid samples from HCV positive individuals that were initially scored negative using the Ortho HCV 3.0 anti-IgG conjugate were subsequently scored positive when detected using the anti-IgG+IgM+IgA cocktail (Table II).
TABLE II Discrepant analysis of select patient oral fluid samples possessing low anti-HCV IgG. Oral fluid Serum Conjugate Patient # (anti-IgG) (anti-IgG + M + A) (anti-IgG) 103-19 0.014 >3.5 2.42 109-03 0.014 2.24 2.25 103-15 0.149 2.60 2.07 109-01 0.213 2.77 2.33 103-01 0.293 >3.5 2.34 103-37 0.357 2.29 1.56 108-06 0.378 >3.5 2.40
[0029] The results indicate that the use of a secondary antibody cocktail that recognizes not only IgG, but IgA and IgM as well, may aid in the detection of the relatively low levels of anti-HCV antibodies present within oral fluid and thus increase detection sensitivity. This increase in detection sensitivity when such an antibody cocktail is used is in good agreement with data showing that a significant percentage of anti-HCV antibodies in oral fluid exist in the form of IgA class antibody molecules (see FIG. 1 ). A recent study by Van Doornum et al. (2001) showed that anti-HCV could be detected with up to 88% sensitivity in oral fluid using a modified protocol with the Mono-Lisa anti-HCV Plus kit. Similar to the Ortho HCV 3.0 assay, however, this kit utilizes an anti-human IgG conjugate antibody, and is therefore incapable of detecting IgA class anti-HCV present in oral fluid samples. Furthermore, in contrast to the HCV 3.0 assay, the Mono-Lisa does not incorporate proteins from the core region of the HCV proteome and sensitivity in oral fluid may be reduced by the inability to capture antibodies directed against this highly antigenic region. By detecting multiple classes of antibodies, and through the use of an ELISA with a high percentage of the total antigenic sequences of HCV coated onto the solid phase, an increase in detection sensitivity to levels comparable to those obtained from serum-based analysis was achieved.
[0030] Thus, the results of this study show that detection of anti-HCV IgG, IgM and IgA in oral fluid samples is essential for correctly diagnosing patient samples possessing relatively low levels of anti-HCV IgG. Indeed, patient oral fluid samples with low anti-HCV IgG levels will escape detection in immunoassays that recognize only IgG class immunoglobulins. By effectively increasing the pool of antibodies detectable in oral fluid samples it is possible to overcome the intrinsic difficulty of detecting the extremely low levels of antibodies in oral fluid and allow for the generation of novel non-blood based immunoassays.
[heading-0031] II. Components of the Test Module for the Oral Fluid Based Lateral Flow Immunoassay
[0032] The HCV immunoassay consists of a single nitrocellulose strip with a mixture of recombinant HCV antigens immobilized in a trapping zone 2.4 cm from the top edge of the strip. The nitrocellulose strip is held stationary within a custom-made plastic cassette assembly ( FIG. 2A ). Oral fluid sample and AP-conjugated goat anti-human IgG+IgM+IgA antibody cocktail are added to the conjugate hinge ( FIG. 2B ) creating a complex of anti-HCV bound by anti-human-AP antibodies. Alternatively, Protein LA conjugated to alkaline phosphatase can be used as the detection molecule. The hinge is then closed and pressed onto the nitrocellulose test strip for 5 seconds. 60 μl of chase solution is then added to a port on the top of the cassette located just above the hinge region ( FIG. 2C ) facilitating the migration of sample complex down the nitrocellulose test strip toward the trapping zone while simultaneously washing unbound conjugate antibody through the trapping zone to the bottom wick to prevent non-specific enzyme luminescence within the trapping zone. Upon reaching the trapping zone, the anti-HCV antibody present in the anti-HCV/anti-human-AP complex binds its cognate antigen, thus ceasing its migration. Dried AP substrate is suspended above the trapping zone ( FIG. 2A ) on a piece of gelbond preventing the substrate from coming into contact with the anti-HCV/anti-human-AP complex in the trapping zone until the cassette is inserted into the luminometer. Four minutes after the addition of the chase solution, the test cassette is inserted into the luminometer. A lever on the back of the cassette is depressed by the luminometer ( FIG. 2D ) bringing the substrate into contact with the anti-HCV/anti-human-AP complex in the trapping zone, thus initiating the luminescence-generating reaction. Luminescence is measured through the window in the top of the cassette for 1 minute.
[heading-0033] III. Selection of HCV Peptide Sequences to be Incorporated Into Trapping Zone of Rapid Immunoassay
[0034] Peptide sequences shown to be strongly antigenic were chosen for synthesis and screening for incorporation into the trapping zone of the HCV immunoassay. U.S. Pat. No. 5,698,390 describes the sequencing of the HCV genome and the use of specific, highly antigenic sequences as tools for immunoassay development of blood-based HCV assays. These sequences, however, have not yet been useful in the detection of HCV in oral fluid with high degrees of sensitivity and specificity for use in screening. Contrary to other assays for HCV exposure, peptides were chosen based on these sequences instead of recombinant antigens for a number of reasons: firstly, since the nucleotide sequence of HCV is well known and many of the strongly antigenic epitopes mapped in detail, highly purified peptides that represent only the strongly antigenic regions of the HCV genome can be synthesized rapidly and in large quantity at relatively low cost. Secondly, because new peptide antigens incorporating different antigenic sequences can be synthesized rapidly, new antigens can be added, or substituted, for peptides already in the assay with relative ease. Thirdly, by incorporating only the highly antigenic sequences of the HCV genome, thus eliminating all non-antigenic sequences, the specificity of the assay can be improved.
[0035] On the basis of data generated by screening 30 patient serum samples against individual peptide antigens in an ELISA format, five HCV sequences were chosen. All 30 serum samples were reactive against at least one of the five peptide antigens (Table III). The following sequences represent the amino acids numbers based on Kato et al. (1990) chosen for use: 7-26, 22-41, 1694-1710, 1710-1728 and 1924-1943. These sequences represent two peptides from the core region of the HCV genome and three peptides from the NS4 region, respectively.
TABLE III Selection of peptides for use in the trapping zone. Thirty serum samples were screened against individual peptides by ELISA. All 30 samples showed reactivity against at least one of the 5 peptides tested. Peptide antigen (aa #s) 1924- 7-26 22-41 1694-1710 1710-1728 1943 Sensitivity 97 97 86 90 83 (%)
IV. Rapid Screening of Oral Fluid Samples for Anti-HCV Using an Affinity Trap Immunoassay
Detection of Monoclonal Anti-HCV Antibodies Spiked Into Oral Fluid
[0038] To determine if low levels of monoclonal anti-HCV antibodies in oral fluid are detectable by the HCV LNSI, a mixture of antibodies against the core, NS3, NS4 and NS5 antigens was added to an HCV(−) oral fluid sample for a final concentration of antibody ranging from 0 to 117 μg/ml. Since all monoclonals were of the IgG subtype, an AP-conjugated goat anti-mouse IgG secondary antibody was used to form the anti-HCV/anti-mouse-AP complex. RLUs for the most concentrated spiked sample were 9-fold higher than those obtained for the 0 μg/ml sample (453584 vs. 50568). From the values obtained a dose response curve was generated with an R 2 =0.98 ( FIG. 3A ).
[0039] To observe the binding of the anti-HCV/anti-mouse-AP complex within the trapping zone visually, cassettes were disassembled following luminescence measurement and the nitrocellulose strips were then stained for 7 min. with NBT/BCIP AP substrate. A coherent trapping zone is visible for assays employing 1.17 to 117 μg/ml spiked monoclonal antibodies in oral fluid ( FIG. 3B ). At 0.12 μg/ml a faint band within the trapping zone is present, while at 0 μg/ml no band is visible within the trapping zone.
[heading-0040] Detection of Anti-HCV in Oral Fluid Samples
[0041] Sixty-four known HCV(+) oral fluid samples and 14 known HCV(−) samples were screened using the invention. A cutoff value was assigned by taking the mean values of the 14 HCV(−) samples plus 2 standard deviations. Using this cutoff value, 63/64 of the known patient samples were scored positive ( FIG. 4 ) leading to a calculated sensitivity of 98.4%. None of the HCV(−) samples obtained values greater than that of the calculated cutoff for a specificity of 100%.
[0042] To visualize the luminescence reaction directly, HCV(+), and HCV(−) saliva samples were imaged by a CCD Light Imager. Assays were conducted in the same manner as described previously with the exception that sticks were imaged in the NightOwl (Bertold Inc. Germany) to detect total luminescence. While HCV (+) samples possess high levels of luminescence, nearly no luminescence is detectable in the HCV(−) sample ( FIG. 4 ).
[heading-0043] V. V. Serial Trapping Zones to Type Antibodies Against Specific Peptides of the HCV Virus.
[0044] Six HCV peptide antigens were coated as individual trapping zones onto a nitrocellulose matrix to demonstrate the ability of the invention to differentially display the patient antibody response from individual subjects. Samples were mixed with Protein LA conjugated to alkaline phosphatase and allowed to migrate through the 6 different trapping zones. During this migration, patient antibodies to the different antigens were selectively captured in the individual trapping zones allowing for a more detailed analysis of the patient antibody response. The peptide composition of each trapping zone was as follows: line 1 aa 384-403, line 2 aa 7-26, line 3 aa 22-41, line 4 aa 1694-1710, line 5 aa 1710-1728, line 6 aa 1924-1943.
[0045] Results of this study clearly show that the antibody response of individual patients can be dissected using this method. This provides a useful means by which antigens to specific genotypes of the HCV virus can be coated onto a suitable matrix and patient samples can then be screened in order to provide information regarding the pattern of antibody response or the strain of virus present ( FIG. 5 ). Such information is useful in tailoring therapy for individual patients on the basis of the HCV genotype present.
[0046] The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations in so far as they come within he scope of the appended claims or the equivalents thereof.
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A method and device to detect Hepatitis C (HCV) antibodies in oral fluid is provided. This method introduces a non-antibody detection molecule that labels all classes of patient antibodies in oral fluid, followed by the specific concentration of labeled anti-HCV antibodies by selective capture in a trapping zone consisting of peptide antigens derived from the HCV genome. Signal generated by the labeled antibodies present in the trapping zone is proportional to the number of anti-HCV antibodies bound to the antigens present in the trapping zone. Presence of signal derived from the capture of antibody/detection molecule complexes in the trapping zone is indicative of past exposure to HCV.
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BACKGROUND
1. Technical Field
The present application is related to manufacturing, and more particularly to electrical device manufacturing methods.
2. Description of Related Art
An electrical device such as a consumer electronics device consists of many electronic and mechanical parts. The electrical device must be tested after assembly to ensure operability. At present, functional testing of the electrical device is frequently performed while the electrical device is being fabricated, whereby the electrical device must be repaired or reworked if it fails the testing.
In the repair process or the rework process, the electrical device may require disassembly to determine problems of each part therein, a significantly time-consuming requirement.
BRIEF DESCRIPTION OF THE DRAWINGS
The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of at least one embodiment.
FIG. 1 is a flowchart of an electrical device manufacturing method according to a first embodiment of the disclosure.
FIG. 2 is a flowchart of an electrical device manufacturing method according to a second embodiment of the disclosure.
DETAILED DESCRIPTION
Various embodiments will now be described in detail, with reference to the drawings.
Referring to FIG. 1 , an electrical device manufacturing method according to a first embodiment of the disclosure includes Steps S 01 to S 05 . The electrical device can for example be a consumer electronics device. Examples of such consumer electronics devices include but are not limited to a digital camera, a mobile phone or a game player.
In Step S 01 , an electronic module such as an image processing module or a sound and light module is provided. The image processing module can include but is not limited to an image capture unit and an image display unit. The sound and light module can include but is not limited to a lighting unit, a microphone, and an amplifier. The lighting unit may include at least one light emitting diode (LED), organic light emitting diode (OLED), or electroluminescent lamp (EL).
In addition, in alternative embodiments, the electronic module can further include a protective shell or cover to protect the electronic components of the electronic module.
In Step S 02 , at least one function of the electronic module is verified by testing, the verification items including but not being limited to electrical characteristics, image capture function, image projection function, and optics detection tests. As should be noted, the electrical characteristics test measures impedance, capacitance, and inductance. In addition, the image projection function test typically checks hues, tints or an auto focus function for an image projected from the electronic module onto a surface external to the electronic module. Moreover, the optics detection test measures the brightness or intensity of light emitted by the lighting unit.
In Step S 03 , a support module is provided, which may be, but is not limited to, a base or holder. The base may provide support on a horizontal surface, and the holder may provide wall-mount capability.
In Step S 04 , at least one function of the support module is verified by testing, the verification items including but not being limited to endurance such as drop and thermal shock tests.
In Step S 05 , the electronic module is attached to the support module, resulting in the final electrical device, and at least one electrical function of the electrical device is verified by testing. Such one or more electrical function tests include but are not limited to image capture function, image projection function, and drop and thermal shock tests.
It should be noted that, in alternative embodiments, Step S 03 can further include integrating a rotation unit, such as a motor or gear, into the base or holder. In such embodiments, the rotation unit connects the base or holder and the electronic module, providing rotation of the electronic module.
FIG. 2 shows an electrical device manufacturing method according to a second embodiment of the disclosure. The electrical device includes a first electronic module, a second electronic module, and a support module. In this exemplary embodiment, the first electronic module is an image processing module and the second electronic module is a sound and light module. The electrical device manufacturing method includes steps as follows.
In Step S 11 , the image processing module is provided. The image processing module can include but is not limited to an image display module or an image capture module. The image display module may be a display panel or a projector. The image capture module may be an image sensor or a camera module.
In Step S 12 , at least one function of the image processing module is verified by at least one function test. The function test items include but are not limited to electrical characteristics testing. A test result of the function test includes a pass status and a fail status. The image processing module can be repaired (or reworked) immediately if one of the test results is the fail status. Alternatively, the image processing module may have to be replaced.
In Step S 13 , the support module is provided. The support module may be, but is not limited to, a base or holder. The base may provide support on a horizontal surface, and the holder may provide wall-mount capability. This step can further include integration of a rotation unit into the base or the holder, wherein the rotation unit can be a motor or gear.
In Step S 14 , at least one function of the support module is verified by at least one function test. The function test items include but are not limited to endurance such as drop and thermal shock testing. The support module is repaired (or reworked) immediately if one of the test results is the fail status. Alternatively, the support module may have to be replaced.
In Step S 15 , the image processing module is attached to the support module to form a first integrated module. If present, the rotation unit connects the support module and the image processing module, providing rotation of the image processing module.
In Step S 16 , at least one function of the first integrated module is verified by at least one function test. The function test items include but are not limited to one or more image tests or an alignment test. The image tests can include image capture function, display function, or image projection function tests. For example, the image projection function test typically checks hues, tints or an auto focus function for an image projected from the image processing module onto a surface external to the image processing module. The alignment test typically checks resolution or display position of an image which is projected onto a surface external to the image processing module or displayed on a screen. The first integrated module can be repaired (or reworked) immediately if one of the test results is the fail status. Alternatively, the first integrated module may have to be replaced.
In Step S 17 , a sound and light module is provided. The sound and light module can include but is not limited to a light emitting unit, a microphone or an amplifier. The light emitting unit can include at least one light emitting diode (LED) or organic light emitting diode (OLED).
In Step S 18 , at least one function of the sound and light module is verified by at least one function test. The verification items include but are not limited to optics detection, sound (e.g. voice) capture function of the microphone or sound output function of the amplifier tests. It should be noted that the optics detection test measures the brightness or intensity of light emitted by the light emitting unit. The sound and light module can be repaired (or reworked) immediately if one of the test results is the fail status. Alternatively, the sound and light module may have to be replaced.
In Step S 19 , the first integrated module and the sound and light module are attached to each other, thereby forming a second integrated module.
In Step S 20 , at least one function of the second integrated module is verified by at least one function test. The verification items may be same as those in Steps S 16 and S 18 , and may further include synchronization of the first integrated module with the sound and light module. The second integrated module can be repaired (or reworked) immediately if one of the test results is the fail status. Alternatively, the second integrated module may have to be replaced.
In Step S 21 , a protection module such as a protective shell for covering and protecting the second integrated module is provided.
In Step S 22 , the protective shell and the second integrated module are attached together, thereby forming an electrical device.
In Step S 23 , at least one function of the electrical device is verified by at least one function test. The verification items may be same as those in Steps S 16 , S 18 and S 20 . The electrical device can be repaired (or reworked) immediately if one of the test results is the fail status. Alternatively, the electrical device may have to be discarded.
The yield rate of the electrical device is increased due to pre-assembly verification of the image processing module, the support module, the first integrated module, and the second integrated module, with repair available in each verification process if required.
It is to be understood, however, that even though numerous characteristics and advantages of certain inventive embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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An exemplary electrical device manufacturing method includes the following steps. First, a first electronic module is provided. Second, one or more functions of the electronic module are verified. Third, a support module is provided. Fourth, one or more functions of the support module are verified. Fifth, the first electronic module is attached to the support module so as to form a first integrated module. Sixth, one or more functions of the first integrated module are verified.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2009-0129259 (Dec. 22, 2009), which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The embodiment relates to a refrigerator.
[0003] Generally, a refrigerator is home appliances that stores food in a low temperature state by a low-temperature air.
[0004] Currently, there has been increasing a demand for a bottom freezer type refrigerator whose refrigerating compartment is provided at an upper side and freezing compartment is provided at a lower side. In the case of the bottom freezer type refrigerator, an ice making device that makes ice and a water dispenser that can take out drinking water may be provided at a door. When the door of a refrigerator is equipped with the ice making device and the water dispenser, water supply hoses connected to the ice making device and the water dispenser expand inside the door.
[0005] In detail, in the structure with the ice making device in the door, in addition to the water supply hose, the door is equipped with built-in control unit and a driving motor for controlling the operation of the ice maker and cables for, and cables for transmitting electric current and operational signals to the control unit and the driving motor. In this configuration, a holder is required to support the connecting terminal, such as a receptacle, formed at the end of the cable connected to the ice maker, and keep their positions while filling the door with an insulator.
[0006] In the related art, the holder was simply attached to the rear side of the outer case forming the front external appearance of the door, by a bonding member. Therefore, there was a problem that the position of the holder changed on the outer case in manufacturing the door, particularly filling the insulator.
[0007] Further, it has been tried to, not filling polyurethane foam, but installing a specific insulator, such as vacuum insulation panel, in the door, in order to achieve a slim door that is equipped with an ice making compartment.
SUMMARY OF THE INVENTION
[0008] The present invention is based on the above technical requirements and it is an object to provide a refrigerator that has a slim door equipped with an ice making compartment and a holder stably fixed to the inside of the door.
[0009] In order to achieve the objects of the present invention, a refrigerator according to an aspect of the present invention comprises: a main body having a storage compartment therein; and a door connected to the main body and opening/closing the storage compartment, wherein the door includes: an outer case defining an external appearance of the door; a door liner combined with the outer case; an insulation material filled between the outer case and the door liner; and a holder supporting both a receptacle connected with a cable for controlling an ice maker and a water supply cock for making ice, the holder disposed between the outer case and the door liner, wherein the holder is fixed to the outer case.
[0010] According to another aspect of the present invention, a refrigerator comprises: a main body; a door including an outer case and a door liner combined with the outer case, the door rotatably connected to the main body; an ice making compartment provided to the door liner and accommodating an ice maker; a water supply cock supplying water to the ice maker; a receptacle connected to an end of a cable for transmitting electric current and/or operational signal to the ice maker; a holder supporting both the water supply cock and the receptacle between the door liner and the outer case; and a insulation plate interposed between the outer case and the holder.
[0011] According to a refrigerator having the above configuration of an embodiment of the present invention, it is possible not to fill polyurethane foam, but to mount a specific insulation panel inside a door.
[0012] Further, it is possible to stably fix a holder supporting the end of a water supply hose and the end of a cable for operating and controlling an ice maker, in side the door, even if a specific insulation panel is mounted.
[0013] Further, it is possible to improve productivity by simplifying the assembly process, as compared with the related art in which a receptacle connected to the end of the cable should be fixed to the holder by a specific bracket and the holder should be bonded to the rear of the door of the refrigerator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an exterior perspective view of a refrigerator according to an embodiment of the present invention;
[0015] FIG. 2 is an exploded perspective view of the door of the refrigerating compartment according to an embodiment of the present invention;
[0016] FIG. 3 is a perspective view showing the front of a holder according to an embodiment of the present invention;
[0017] FIG. 4 is a perspective view showing the bottom of an upper panel attached to the upper side of the door of a refrigerating compartment according to an embodiment of the present invention;
[0018] FIG. 5 is a cross-sectional view illustrating the connection between the holder and the upper panel, taken along the line I-I of FIG. 2 ; and
[0019] FIG. 6 is a cross-sectional view illustrating the connection between a holder and an upper panel according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Hereinafter, the structure of a refrigerator according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0021] FIG. 1 is an exterior perspective view of a refrigerator according to an embodiment of the present invention.
[0022] Referring to FIG. 1 , a refrigerator 10 according to the embodiment of the present invention includes a main body 11 that includes a refrigerating compartment 111 and a freezing compartment therein, a refrigerating compartment door 12 opening/closing the refrigerating compartment 111 and a freezing compartment door 13 opening/closing the freezing compartment, which are rotatably connected to the front edge of the main body 11 .
[0023] In detail, the freezing compartment may be formed as a single space under the refrigerating compartment 111 and may be divided into a plurality of spaces by specific partitions for products.
[0024] Though not shown, a storage box capable of being drawn forward may be provided in the freezing compartment. A drawer is further provided in the freezing compartment and includes a door selectively blocking the front opening of the freezing compartment, a door frame extending backward from the rear of the door, and a rail connected to the storage box seated on the door frame and the door frame for the door to slide forward/backward.
[0025] Further, the freezing compartment may be divided into a plurality of spaces in the up-down direction or the left-right direction by specific partitions. The figures show when the freezing compartment is divided in the up-down direction and each space is blocked by the door 13 . Further, any one of the spaces divided by the partitions in the freezing compartment may be used as a convertible compartment. Accordingly, the door 13 opening/closing the freezing compartment 13 may have a convertible compartment door and a freezing compartment door.
[0026] A plurality of shelves and baskets may be provided in the refrigerating compartment. The front opening of the refrigerating compartment 111 , as shown in the figure, can be opened/closed by a pair of refrigerating doors 12 . The pair of refrigerating doors 12 can be rotatably connected to the left and right edges of the main body 11 .
[0027] Further, an ice making compartment 20 for making ice may be provided on the rear of the refrigerating compartment door 12 and one or more door baskets 15 may be attached to the outer surface of the ice making compartment 20 . A cooling air inlet 123 and a cooling air outlet 124 may be formed in the side of the ice making compartment 20 , that is, the side contacting with the inside of the refrigerating compartment 111 . Further, a cooling air inlet and a cooling air outlet are at the side of the refrigerating compartment 111 where the cooling air inlet 123 and the cooling air outlet 124 are in contact when the refrigerating compartment door 12 is closed. Furthermore, a cooling air supply duct and a cooling air return duct which are connected with an evaporation compartment (not shown) may be formed in the side of the refrigerating compartment 111 .
[0028] Further, one or more door baskets 16 may be provided to the rear of the refrigerating door 12 , corresponding to the bottom of the ice making compartment 20 . A water storage unit 30 having a predetermined size may be provided on the rear of the lower end portion of the refrigerating compartment door 12 .
[0029] Meanwhile, a dispenser (not shown) may be formed on the front of the refrigerating compartment door 12 , in particular, the front of the refrigerating compartment door 12 where the ice making compartment 20 is formed, in order to take out drinking water and ice. Further, a water supply hose ( 41 in FIG. 2 ) extends from the rear of the main body 11 into the refrigerating compartment door 12 through a hinge connecting the refrigerating compartment door 12 with the main body 11 . Furthermore, the water supply hose 41 extending into the refrigerating compartment door 12 branches off to an ice maker (not shown) provided in the ice making compartment 20 and a water-taking opening of the dispenser, across the water storage unit 30 .
[0030] FIG. 2 is an exploded perspective view of a refrigerating compartment door according to an embodiment of the present invention.
[0031] Referring to FIG. 2 , the refrigerating compartment door 12 according to an embodiment of the present invention includes an outer case formed of a metal plate to form the front external appearance, a door liner 122 attached to the rear of the outer case 121 , and a polyurethane foam insulator (not shown) filled between the outer case 121 and the door liner 122 .
[0032] In detail, a filler 16 may be attached to the side of the door liner 122 , in detail, the side corresponding to the surfaces facing each other when the pair of refrigerating compartment doors are closed. The filler 16 is in closed contact with a side of the door liner 122 when the refrigerating compartment door 12 is open, as shown in the figures. On the contrary, when the refrigerating compartment door 12 is closed, the filler rotates at 90° to block the interface with the refrigerating compartment door such that the cooling air is prevented from leaking through the interface between the refrigerating compartment doors.
[0033] Meanwhile, as shown in FIG. 2 , the water storage unit 30 is positioned under the door liner 122 , and a tank housing 123 accommodating a water tank (not shown) and a valve (not shown) is formed under the door liner 122 .
[0034] In detail, the outer case 121 is formed of a metal plate and has a plastic upper panel 126 on the upper end. A hinge is fastened to the upper edge of the outer case 121 and the inside of the hinge is empty. The water supply hose 41 extends along the rear of the outer case 12 through the hinge, as shown in the figure. The end of the water supply hose 41 is connected to the water tank (not shown) in the tank housing, through the tank housing 123 of the door liner 122 , at the lower end of the outer case 121 . In the figure, the region A is where the tank housing 123 of the door liner 122 is disposed. An ice maker hose 44 and a dispenser hose 43 that extend from the outlet of a diverging valve (not shown) disposed in the tank housing 123 extend upward along the rear of the outer case 121 . The end of the hose connected to the water outlet of the water tank is connected to the inlet of the diverging valve.
[0035] Meanwhile, a holder 50 supporting a receptacle R connected to a substrate for controlling the ice maker and a water supply cock 441 through which water is supplied to the ice maker are disposed at the upper portion of the rear of the outer case 121 . Further, the holder 50 is fixed to the upper panel 126 a specific insulation panel 80 , such as a vacuum insulation panel, may be attached to the rear of the outer case 121 corresponding to the front of the ice making compartment 20 . In detail, the vacuum insulation panel is formed by combining a plurality of thin metal plate with a vacuum space therein. The vacuum space is maintained in a substantially vacuum state, under 0.0001 atmospheric pressure. An absorbent, such as silica gel, may be provided in the vacuum space to remove moisture that may be created in the vacuum space by changes in temperature etc. Unlikely, the vacuum insulation panel may include a core formed by pressing glass fiber and a seal cover covering the core. Structures known in the art can be used for the vacuum insulation panel and the detailed description is not provided. The vacuum insulation panel has a larger insulation performance per unit thickness than the insulation foam. Therefore, it is possible to achieve the same insulation performance as the insulation foam, even if using a vacuum insulation panel thinner than the insulation foam. Since a vacuum insulation panel 80 is provided for the refrigerating compartment door of the refrigerator according to an embodiment of the present invention, the thickness of the refrigerating compartment door 12 can be reduced.
[0036] Further, the insulation panel 80 is interposed between the outer case 121 and the holder 50 . A dispenser housing 70 depressed to accommodate a vessel for taking out drinking water and ice may be attached to the rear of the outer case 121 . An ice suit 71 that guides ice made in the ice making compartment 20 to be discharged outside the refrigerating compartment door 12 may be mounted on the upper end of the dispenser housing 70 . A water cock for taking out water is formed at the front of the ice suit 71 .
[0037] In the refrigerator having the above structure, the dispenser hose 43 extends upward to the water cock and the ice maker hose 44 extends further upward than the dispenser hose 43 to the water supply cock 441 .
[0038] FIG. 3 is a perspective view showing the front of the holder according to an embodiment of the present invention.
[0039] Referring to FIG. 3 , the holder 50 may be formed by injection-molding plastic and has a PCB seat 511 where a control substrate controlling the operation of the ice maker, a holder body 51 provided with a water supply cock guide covering the upper surface of the water supply cock 441 to protect it, and a fastening arm 52 extending from the upper surface of the holder body 51 .
[0040] In detail, a receptacle hole 512 is formed at the upper portion of the PCB seat 511 and a receptacle (not shown) connected to the end of a group of a plurality of cables extending from a main control unit of the main body 11 of the refrigerator is inserted in the receptacle hole 512 . The receptacle is connected with a connector extending from the substrate seated on the PCB seat 511 . The water supply cock 441 that is made of metal and rounded is connected to the end of the ice maker hose 44 , protruding forward from the backward of the holder 50 . The water supply cock guide 513 is rounded, taking the shape of the water supply cock 441 . A heater is attached to the outer circumference of the water supply cock 491 to prevent freezing inside the water supply cock 441 .
[0041] On the other hand, a fastening hole 521 is formed through the upper surface of the fastening arm 52 and at least one temporary connecting protrusion 522 may be formed around the fastening hole 521 . A fastening member that passes through the outer case 121 of the refrigerating compartment door 12 is inserted in the fastening hole 521 . A preliminary fastening protrusion of the outer case 121 is inserted in the preliminary fastening hole 522 and this is described below with reference to the drawings.
[0042] FIG. 4 is a perspective view showing the bottom of an upper panel attached to the upper side of the door of a refrigerating compartment according to an embodiment of the present invention.
[0043] The upper panel 126 , as described above, is mounted on the upper end of the outer case 121 . In detail, fastening holes 126 a corresponding to the number of fastening arms 52 may be formed in the upper panel 126 . Further, at least one or more preliminary fastening protrusions 126 b protrude from the bottom of the upper panel 126 spaced from the fastening holes 126 a.
[0044] By inserting the preliminary fastening protrusions 126 b in the preliminary fastening holes 522 , it is easy to arrange the fastening holes 521 and 126 a in assembling the holder 50 .
[0045] FIG. 5 is a cross-sectional view illustrating the connection between the holder and the upper panel, taken along the line I-I of FIG. 2 .
[0046] Referring to FIG. 5 , the fastening arm 52 of the holder 50 is in close contact to the bottom of the upper panel 126 . Accordingly, the fastening holes 521 of the fastening arm 52 meet the fastening holes 126 a of the upper panel 126 . Fastening members, such as screws, are sequentially inserted into the fastening holes 126 a and 152 . The holder 50 is firmly fixed to the upper panel 126 of the outer case 121 by the above assemblage. The holder 50 is fixed apart from the outer case 121 . The insulation panel 80 is disposed in the space between the holder and the outer case. The insulation panel 80 can be firmly fixed to the rear of the outer case 121 by a bonding member. Further, as described above, the insulation panel 80 may be formed to have a size corresponding to that f the ice making compartment 20 . By interposing the insulation panel 80 , heat exchange between the ice making compartment 20 and the air outside the refrigerator is prevented, such that it is possible to prevent the internal temperature of the ice making compartment 20 from increasing. Further, since a vacuum insulation panel 80 is used as the insulation panel 80 , it is possible to achieve heat insulation effect at least the same as or more than when insulation foam is filled in the related art. Furthermore, since it is not necessary to fill the portion where the insulation panel 80 is attached with specific insulation foam, the distance from the front of the refrigerating compartment door 12 to the rear of the ice making compartment, that the thickness of the refrigerating compartment door 12 around the ice making compartment is reduced.
[0047] After the insulation panel 80 is attached to the rear of the outer case 121 and the holder 50 is fixed to the upper panel 126 from the backward of the insulation panel 80 , as described above, the door liner 122 is combined. Further, insulation foam is filled in the space between the door liner 122 and the outer case 121 . Since the holder 50 is fixed to the upper panel 126 , it is possible to prevent the holder 50 from being moved by injection speed of the insulation panel in filling the insulation foam.
[0048] FIG. 6 is a cross-sectional view illustrating the connection between a holder and an upper panel according to another embodiment of the present invention.
[0049] Referring to FIG. 6 , specific fasteners, such as screws, are not necessary to fix the holder 50 to the upper panel 126 .
[0050] In detail, fastening hooks 523 , instead of the fastening holes, may protrude from the upper surface of the fastening arm 52 of the holder 50 . Further, the fastening hooks 523 may be injection-molded integrally with the holder 50 to have a predetermined elastic force.
[0051] According to this configuration, the fastening hooks 523 pass through the fastening holes 126 a of the upper panel 126 by closely contacting the fastening arm 52 of the holder 50 to the bottom of the upper panel 126 . Further, since the fastening hooks 523 have elasticity, they contacts while passing through the fastening holes 126 a and then return to the initial shape after completely passing through the fastening holes 126 a. Therefore, it is possible to firmly fix the holder 50 to the bottom of the upper panel 126 .
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The present invention relates to a refrigerator, which comprises: a main body having a storage compartment therein; and a door connected to the main body and opening/closing the storage compartment, wherein the door includes: an outer case defining an external appearance of the door; a door liner combined with the outer case; an insulation material filled between the outer case and the door liner; and a holder supporting both a receptacle connected with a cable for controlling an ice maker and a water supply cock for making ice, the holder disposed between the outer case and the door liner, wherein the holder is fixed to the outer case.
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CROSS-REFERENCES
[0001] The present application claims the benefit of provisional patent application No. 61/347,155 filed on May 21, 2010 by Patrick B. Harris, the entire contents of which are fully incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to an apparatus that can both dispense items, and dispose of the items, and more specifically relates to an apparatus that can both dispense and dispose of paper items, such as tissues.
BACKGROUND
[0003] Disposable products, such as tissue papers, papers towels, napkins, moist wipes, etc., are often stored in some type of package. For example, unused tissue papers may be stored in a cardboard box containing a perforated cover. A user typically tears open the perforated cover to access the unused tissue papers. After using the tissue paper, a user may dispose the tissue paper in a waste basket.
[0004] In many situations, there may not be a waste basket or other container available in which to dispose the used tissue paper or other disposable product. In such situation, a user may place the used tissue paper in an undesirable location, such as on top of a table, on a chair, on the floor, or in one's pocket. Such undesirable disposal of the used tissue paper may lead to non-environmentally friendly disposal and may also lead to unsanitary conditions, which may result in illness in people who come in contact, directly or indirectly, with the used tissue paper.
[0005] Often times, a person may need to use a tissue when in a vehicle, and often times there is not an adequate place to hold a tissue container, and there may also be no adequate place to dispose of the used tissue.
[0006] Thus, there is a need for an apparatus that overcomes the above and other disadvantages.
SUMMARY OF THE INVENTION
[0007] The disclosed invention relates to a dispenser and disposal system comprising: a cup, the cup comprising and interior volume, and an exterior surface; a lid removably attachable to the cup, the lid having a top side and an underside; a first pouch in communication with the lid, located in the interior volume, and in communication with the first slot, the first pouch comprising a first end that is generally adjacent to the lid, and a second end distal to the lid, and wherein the first end generally comprises an opening to the first pouch; and a second pouch in communication with the lid, located in the interior volume; and in communication with the second slot, the second pouch comprising a first end that is generally adjacent to the lid, and a second end distal to the lid, and wherein the first end generally comprises an opening to the second pouch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present disclosure will be better understood by those skilled in the pertinent art by referencing the accompanying drawings, where like elements are numbered alike in the figures, in which:
[0009] FIG. 1 is a side exploded view of the disclosed apparatus;
[0010] FIG. 2 is a top view of the disclosed apparatus;
[0011] FIG. 3 is a top view of a lid;
[0012] FIG. 4 is a side cross-sectional view of the lid;
[0013] FIG. 5 is a top view of the bottom mounting ring;
[0014] FIG. 6 is a side cross-sectional view of the bottom mounting ring;
[0015] FIG. 7 is a top view of the top mounting ring;
[0016] FIG. 8 is a side cross-sectional view of the top mounting ring;
[0017] FIG. 9 is a top view of a wire mounting ring;
[0018] FIG. 10 is a perspective view of the wire mounting ring attached to various components of the apparatus;
[0019] FIG. 11 is a top view of the winged mounting ring before being folded closed;
[0020] FIG. 12 is a side view of the device with a wire used on the bags;
[0021] FIG. 13 is a perspective view of the bag after the wire is installed and the bag it is sealed;
[0022] FIG. 14 shows several views of the device being assembled;
[0023] FIG. 15 is a side view of the disclosed up and a holder;
[0024] FIG. 16 is a top view of the disclosed holder;
[0025] FIG. 17 is a top view of the disclosed lid:
[0026] FIG. 18 is a perspective view of another embodiment of the disclosed apparatus;
[0027] FIG. 19 is a bottom perspective view of the apparatus from FIG. 18 , with the cup removed;
[0028] FIG. 20 is an exploded view of the apparatus from FIGS. 18 and 19 ; and
[0029] FIG. 21 is an exploded view of another embodiment of the disclosed apparatus.
DETAILED DESCRIPTION
[0030] FIG. 1 shows a front exploded view one embodiment of the disclosed apparatus 10 . The apparatus comprises a cup 14 . The cup 14 may be tapered as shown, or may be shaped more cylindrically (with generally parallel sides). The cup may have an opened bottom 16 . In other embodiments, the bottom 16 may closed, or have a removable bottom. Located within container is a dual-pouched bag 18 , shown in dashed line when in the cup 14 . The bag 18 has a first pouch 22 and a second pouch 26 . In one alternative embodiment, the second pouch 26 may have a sealable opening 30 at or near its bottom. The sealable opening 30 may be any suitable type of closeable opening including but limited to Ziploc style openings, zippered opening, and adhesive openings. The apparatus 10 also comprises a bottom mounting ring 34 , a layer of material 38 , such as but not limited to cellophane, a top mounting ring 42 , and a lid 46 . The lid 46 attaches to the cup 14 , and when attached to the cup 14 , the dual pouched bag 18 is held between the bottom mounting ring 34 , and the layer of material 38 and the top mounting ring 42 . The first pouch 22 is configured to hold a plurality of tissues arranged such that one tissue at a time may be dispensed from the apparatus 10 . Although this disclosure discusses tissues, one of ordinary skill in the art will recognize that polishing wipes, car tire protectant wipes, metal polishing wipes, window polishing wipes, disinfectant wipes, anti-bacterial wipes and the like may all be used in the disclosed cups instead of tissues. The second pouch 26 is configured to accept used tissues and other small refuse. If the second pouch 26 is filled up before the first pouch 22 is empty, one can empty the second pouch 26 by opening the sealable opening 30 , and emptying out the second pouch 26 . In another embodiment a single ring may be used and the bags mounted directly to the single ring. The apparatus may also comprise a sleeve configured to slide over the cup 14 . The sleeve may have artistic designs, kids games, kids puzzles, areas for coloring, lined areas for list writing and memos, and calendars. The sleeve may be made out of any suitable material including but not limited to paper, cardboard, and plastic.
[0031] FIG. 2 is a top view of the disclosed apparatus 10 . In this view, the lid 46 is visible. The lid 46 has two openings 50 , 54 . The top mounting ring 42 also has two openings 58 , 62 . The bottom mounting ring 34 also has two openings 66 , 70 . These pairs of openings, 50 , 54 , 58 , 62 , 66 , 70 allow for access to each of the two pouches 22 , 26 . The material layer 38 has a first 74 and second slot 78 configured to be generally centrally located within the openings 50 , 54 , 58 , 62 , 66 , 70 . Thus one may remove a tissue from a first pouch 22 , and dispose of the tissue, or other refuse, into the second pouch 26 , via the slots 74 , 78 . Each of the slots may also have a reinforcement strip 82 , 86 associated with them. The lid 46 may snap or screw onto the cup 14 . The top and bottom mounting rings 34 , 42 may be glued, stapled or otherwise attached to each other, with the dual-pouched bag 18 and layer of material 38 held between the two attached rings 34 , 42 .
[0032] FIG. 3 is a top view of the lid 46 . In this view the openings 50 and 54 are shown alone. FIG. 4 is a side cross-sectional view of the lid 46 .
[0033] FIG. 5 is a top view of the bottom mounting ring 34 . FIG. 6 is a side cross-sectional view of the bottom mounting ring 34 .
[0034] FIG. 7 is a top view of the top mounting ring 42 . FIG. 8 is a side cross-sectional view of the top mounting ring 42 .
[0035] In another embodiment shown in FIG. 11 , instead of having two separate mounting rings, the pattern for the mounting ring includes two wings 100 , 101 that when folded inward matches the mounting ring in the center 102 . Additionally in FIG. 12 we see a small gauge pliable wire 103 is attached to the bag material 105 before the bag sides are sealed. FIG. 13 shows the wired bag opening 104 supported with wire 103 to give the bag an opened form. The bags 106 are linked together at their midpoints 107 , see FIG. 14 . The bags 106 are then dropped into the mounting ring through holes 108 , 109 of the center mounting ring 102 . A cellophane type material 112 may then be placed on top of the center mounting ring 102 . The wings 100 , 101 are then folded inward and plastic welded to the center mounting ring 102 . The holes in the mounting ring wings 100 , 101 are thereby aligned directly over the holes in the center mounting ring 110 , 111 so that the bags openings 104 , 104 may be accessed through the holes. Tabs may be placed on two opposite sides of the mounting ring which would be able to be set into a hole-slot in the cup to secure the mounting ring and bags in the cup. In another embodiment, instead of using mounting rings to couple the bags 106 to the cup 14 , the bags 106 may be coupled to the cup 14 , by other attachment means, including but not limited to adhesives, tape, two-sided tape, Velcro, glue, etc.
[0036] In other embodiments, the apparatus may be square shaped, like a box, or rectangular shaped instead of cup shaped. Instead of a cup 14 , the apparatus may comprise a rectangular box, with two openings at its top, and a dual-pouched bag for tissue and refuse, with one opening in the top of the box for receiving the tissue and one opening in the top of the box for disposing of the tissue and other refuse.
[0037] The cup may have a separate holder 120 for placement of cell phones, Chap Stick or other normal things carried in vehicles and may be attached to the cup using an adjustable clasp system which wraps around the cup and then is anchored by exposing a sticky tape, Velcro. wire, snaps or any other means. FIG. 15 shows a side view of the cup 14 with the separate holder 120 attached to it. The holder 120 may have a generally tapered and generally curved attachment side 124 that allows it to abut the tapered and rounded cup 14 . FIG. 16 shows a top view of the holder 120 . One can see a generally crescent moon shape of the holder 120 in this view. FIG. 17 shows an optional lid 128 that can fit onto the top of the holder 120 .
[0038] In use, once the tissue containing pouch 22 is emptied, one removes the lid 46 , and simply throw away the dual pouched bag 18 , the two mounting rings 42 , 34 , and the layer of material 38 , and simply replace with a new dual-pouched bag 18 that is attached to two mounting rings 42 , 34 along with a layer of material 38 . The cup 14 may have an outer diameter configured to fit cup holders in vehicles, boats, trains, etc. In another embodiment, instead of two mounting rings 34 , 42 , a single mounting ring made of wire or thin material may be used, with the dual-pouched bag attached to the wire ring, and the layer of material attached to the wire mounting ring. See FIG. 9 for a top view of the wire mounting ring 90 . The wire mounting ring 90 has two openings 94 , 98 for each of the pouches 22 , 26 . FIG. 10 shows the wire mounting ring 90 with the dual-pouched bag 18 and material layer 38 attached to it. In still another embodiment, Velcro strips may be located on the sides of the cup, so that Velcro material may be attached to the Velcro strips in order to increase the circumference and/or diameter of the cup so that it will fit in larger cup holders. In another embodiment, tacky putty may be removeably attached to the bottom of the cup, to more firmly secure the cup to table tops, desks and other surfaces, and reduce the chances of the cup from being knocked over.
[0039] FIG. 18 is a perspective view of another embodiment of the disclosed dispenser 140 . In this embodiment, the dispenser comprises a cup 14 (shown in dashed line) and a lid 46 . The lid may have a first slot 74 and a second slot 78 . Slot 74 may be a an x-shaped or cross-shaped slot. In this embodiment, a first bag 144 and a second bag 148 are both attached to the underside 152 of the lid 46 . The bags 144 , 148 may be attached to the underside 152 of the lid 46 via an adhesive, staples, two-sided tape, Velcro, glue or any other suitable attachment means. The first bag 144 will act as a trash receptacle. The first bag 144 may have a resealable opening 156 . The resealable opening 156 may be, but not limited to zippered opening, Ziploc style opening, a zipper lock type resealable opening, either with or without a slider, or an opening that can be resealed with an adhesive. The second bag 148 is configured to hold numerous tissues, wipes, etc. Thus, in use, one may simply pull a tissue or wipe, from the slot 78 . When the user is done with the tissue or wipe, the user can insert the used tissue or wipe into slot 74 , thereby depositing the used tissue or wipe into the first bag 144 . If the first bag becomes full with used tissues and wipes, or other trash, the user may simply remove the lid from the cup, with the first and second bags 144 , 148 still attached to the lid. The user may then unseal the resealable opening 156 and dispose of the trash in the first bag 144 , close the resealable the opening 156 , and place the lid 46 back on the cup 14 , with the bags 144 , 148 back inside the cup, but now with the first bag 144 generally empty. FIG. 19 is a bottom perspective view of the lid 56 and the bags 144 , 148 . In this view, for this embodiment, an adhesive 160 that attaches the bags 144 , 148 to the underside 152 of the lid 46 is shown as the shaded material.
[0040] FIG. 20 is a exploded view of the device from FIGS. 18 and 19 . In this view the lid 46 is shown attached to the cup 14 . A lid cap 164 is shown above the lid 46 . A sealing device 168 is shown above the lid cap 164 . The sealing device 168 may be a seal made of a thin plastic material that generally covers the perimeter of the lid 46 and generally an outer circumference of the lid cap 164 , and seals the cap 164 against the lid 46 . The sealing device 168 may have a perforated portion 172 to allow a user to conveniently remove the sealing device 168 from the cup, and remove the cap 164 , to allow the user to pulls tissues or wipes from the slot 78 , and dispose the of the tissues or wipes in the slot 74 .
[0041] FIG. 21 is an exploded view of another embodiment of the disclosed invention 200 . IN this embodiment, the cup 14 has an interior volume which is configured to contain a first bag 178 and a second bag 179 . First bag 178 may be configured to hold a plurality of tissues. Second bag 179 may be configured to be a trash bag to hold refuse, such as used tissues, or other trash. First bag 178 may have a resealable opening 182 . The resealable opening may be, but not limited to zippered opening, Ziploc style opening, a zipper lock type resealable opening, either with or without a slider, or an opening that can be resealed with an adhesive. The bags 178 , 179 may be attached to the underside 204 of a dust cover 176 . The dust cover may be made out of plastic, or cellophane, or any other suitable material. The bags 178 , 179 may be attached to the dust cover 176 via an adhesive, staples, two-sided tape, Velcro, glue or any other suitable attachment means. A first slot or cross-slit 177 may be located in the dust cover, and be configured to be in communication with the interior for the first bag 178 . A second slot or cross-slit 208 may be located in the dust cover, and be configured to be in communication with the interior of the second bag 179 . A lid 175 is removably attachable to the cup 14 . The lid may have a first and a second generally crescent shaped opening 173 , 174 . The openings 173 , 174 may also be generally semi-circular shaped. The dustcover 176 is attached to the underside of the lid 175 , via an adhesive, staples, two-sided tape, Velcro, glue or any other suitable attachment means.
[0042] The disclosed invention has many advantages. The cup may be configured to be held any sized cup holder, thus keeping the cup in a secure and known location. Having tissues dispensing and disposal in the same container keeps the location clean of used tissues that typically are placed in ones pocket or the floor, armrest, cup holder or door pocket. The dual-pouched bag and a vertical rolling of the tissues give extra protection to new tissues should the disposal side bag rip or tear due to over exertion during disposal. The tissues in one pouch may be folded into a tube formation. This enables many more tissues to be place in the dispensing end than tissues folded in any other discovered way; gives a third layer of protection from anything placed in the disposal side. This is accomplished by the wrap around effect of the tube using the outer layer of tissues to protect the inner layers of tissues until one gets to the last few tissues. The lid and dual-pouched bag are completely disposable. When all of the tissues are used, the bag system (lid, material layer, mounting rings and attached dual-pouch bags) are removed from the cup and thrown away. The cup is constructed for reuse. A new plastic bag system (with lid and fresh tissues, dispensing and disposal bags) are placed on the same cup used the last time. In another embodiment the cup and lid are reusable and the plastic bag system (with mounting ring and fresh tissues and dispensing and disposal bags) are placed on the same cup as before and covered with the same lid as before. Specially manufactured tissues may be used so as to conform for the size or the cup. One, two or three ply tissues may be used. The disclosed apparatus may be modified for additional benefits. A disposal only plastic bag system may be supplied for installation on the cup. If tissues are not needed at any time period, the disposal only bag system can replace the standard plastic bag system on the cup and the cup can be used for disposal of any materials (size appropriate) in ones travels. The cup itself can be decorated for different seasons, age groups, holidays etc. The cup can be used for the dispensing and disposal of food items such as peanuts and their shells, candy, chocolate, nuts, and other foods. The apparatus may comprise a disposable boxed shaped unit with two chambers. One side is for dispensing preloaded tissues and the other side is for the disposal of used tissues or any size appropriate materials. This embodiment is designed for use in the home, daycare, hospital rooms or doctor's waiting rooms and offices, for example. The dispensing chamber may be specially made so as to use the same size tissue as the vehicle cup holder version. The disposal side is the same size container as the dispensing side so that only one size box need be manufactured. A separate container can be attached to make room for holding personal items such as reading glasses, pens or cell phones. In another embodiment, the disposable box shaped unit may be smaller and a convenient size for fitting in a purse or for taking in a backpack. One side of the unit is a chamber for dispensing preloaded tissues and the other side of the unit is a chamber for disposal of used tissues. There may be a small chamber on one end for storage of chapstick or something similar in size such as a small antibiotic spray bottle. Another embodiment may comprise a single unit, sized for coffee tables and night stands, which holds replaceable throw away containers (for dispensing and disposal of tissues, napkins, paper towels, moist wipes, food, and the like), personal items (such as glasses, TV controllers and pens) and table coasters. The construction of this boxed shaped unit may be such that the bins are separated by a personal item storage section. The table coaster holder is located directly below the previously mentioned bins and personal storage area, with the opening large enough to slide typical table coasters in for storage. The disclosed apparatus may be constructed of wood, plastic or vinyl covered boxed frames. Cardboard may be used, as well as any other suitable material. In another embodiment, each of the chambers may be covered by a lid hinged at the back of the box such that when the lid is closed the chambers are completely covered. When the lids are flipped open the doors disappear behind the unit. Picture holders may be installed on the inner side of the two chambers lids so the when the lid is opened a favorite picture will be displayed on the backside of the box. A container of tissues may be loaded in one of the bins of the unit and an empty container is loaded into the disposal side. These containers may be made of cardboard. The disposal containers may be folded before use for ease of storage. The containers may throwaway and replaceable and recyclable. The personal storage may be divided and sized for holding two remote controls. The rest of the area may be divided into areas for other items such as reading glasses and pens. Partition dividers are supplied so that the different areas of the storage area can be altered by placing a partitions where needed. A small clock can be mounted in the front of box. An antimicrobial, or antibacterial, or antiviral material may be used for all or portions of this device. The disclosed device is a green device in that prevents littering.
[0043] It should be noted that the terms “first”, “second”, and “third”, and the like may be used herein to modify elements performing similar and/or analogous functions. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated.
[0044] While the disclosure has been described with reference to several embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.
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A dispenser and disposal system comprising: a cup, the cup comprising and interior volume, and an exterior surface; a lid removably attachable to the cup, the lid having a top side and an underside; a first pouch in communication with the lid, located in the interior volume, and in communication with the first slot, the first pouch comprising a first end that is generally adjacent to the lid, and a second end distal to the lid, and wherein the first end generally comprises an opening to the first pouch; and a second pouch in communication with the lid, located in the interior volume; and in communication with the second slot, the second pouch comprising a first end that is generally adjacent to the lid, and a second end distal to the lid, and wherein the first end generally comprises an opening to the second pouch.
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RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/099,774, filed Apr. 6, 2005, now abandoned which is a divisional application of U.S. Ser. No. 10/639,552, filed Aug. 12, 2003, now U.S. Pat. No. 6,940,665 which is a divisional application of U.S. Ser. No. 09/920,060, filed Aug. 1, 2001 (now U.S. Pat. No. 6,608,722), which claims priority to U.S. Ser. No. 60/222,182, filed on Aug. 1, 2000, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to an optical diffuser and method for making the same, and more particularly to an optical diffuser having a high diffraction efficiency, broadband response and cost effective method of producing the same.
BACKGROUND
Reflective diffusers are required for many applications, including liquid crystal displays, to enhance their viewability. Often these diffusers, placed behind the liquid crystal element, are simply roughened reflective surfaces. These reflectors utilize no back lighting, but instead rely on the scattered reflection of the ambient light. Unfortunately, light scattered from these devices is centered around the glare angle, which is in direct line-of-sight with the undesirable reflections from their front surface. Furthermore in many applications, such as computer screens, and perhaps watches, the preferred orientation of the device is one for which viewing at the glare angle is not optimum. The situation can be improved by using holographic diffusers which allow the reflection angles of interest to be offset, so that the maximum brightness from the diffuser falls in a preferred viewing angle which is different from that of the glare. One type of holographic diffuser that is sometimes used is the reflective, “surface-relief” hologram. This hologram has the advantage over other types in that if the ambient light is white, the reflected diffuse light is also white. Another advantage of the surface-relief hologram is that embossing can reproduce it easily and inexpensively. A major disadvantage is that the surface-relief hologram can be inefficient. Only a relatively small percentage of the incident light is diffracted into the desired viewing angles (typically less than 30 degrees).
A non-holographic diffuser, when coupled with a reflective focusing screen, uses randomly sized and randomly placed minute granules, which are created by interaction of solvent particles on plastic surfaces (See U.S. Pat. No. 3,718,078, entitled, “Smoothly Granulated Optical Surface and Method for Making Same”). These granules are dimples of extremely small magnitude (one half of a micron in depth), which reflect incident light more or less uniformly over a restricted angle. However, the angles of reflectance are very small, usually about + or −3 degrees, and the light reflected from them is here again at the glare angle.
A second kind of off-axis, holographic diffuser in common use today is the volume reflection diffuser, which can be provided by Polaroid Corporation of Cambridge Mass. With volume holograms, fringes that give rise to the diffuser reflection are distributed throughout the volume of the material, unlike the surface reflection concept of the “surface-relief” holograms. Because of this, light of a wavelength that is characteristic of the spacing distance between the fringe planes is resonantly enhanced over all other wavelengths. Thus, the reflected light is highly monochromatic. For example, if the spacing is characteristic of green, then green will be the predominant reflected color for incident white light. Unlike conventional embossed holographic diffusers, the reflection can be extremely efficient, although only over a narrow wavelength band. As a result, the surface-relief hologram can appear dim because most of the incident white light falls outside of this select band. Further processing can increase the bandwidth, thus increasing the apparent brightness, but the resulting diffuser still has a predominant hue, which is in most cases undesirable. In any event the bandwidth is still somewhat restricted, thus limiting the reflection efficiency.
Therefore, an unsolved need has remained for a diffuser having a high diffraction efficiency, broadband response and cost effective manufacture, which overcomes limitations of the prior art.
SUMMARY OF THE INVENTION
In an embodiment of the present invention as set forth herein is a blazed diffuser, which includes a reflective surface having a sawtooth structure. The sawtooth structure includes a series of contiguous wedges, each of which reflects incident oblique light into a beam which is more or less normal to the gross surface of the device. This wedge structure may be regarded as simply an off-axis mirror if the wedge spacing (period) is much larger than the wavelength. Superimposed on this wedge surface is a second structural component, which by itself diffracts incident light normal to its surface into rays, which constitute only those over a restricted narrow angle (e.g. + or −15 degrees). This angle is specified as that which is desired for a particular application. In an embodiment, this second surface shape is one that uniformly scatters an incident ray throughout the viewing angle. Such a structure gives a so called “flat top” scattering. When these two structures are superimposed, light incident from a predetermined angle which is dependent on the wedge angle, is uniformly scattered throughout a specified range of viewing angles with a high degree of efficiency. Almost all incident light is utilized and efficiencies approaching 100% for all visible wavelengths are possible.
In another embodiment, a blazed diffuser is made entirely by optical, holographic means, and it can be fabricated in such a way that the broadband spectral colors are properly mixed so that the diffracted light appears white. The recording for this diffuser is done in two primary ways. The first is by recording directly from a predetermined diffuse surface, and the second is by copying from a volume diffuser into a surface diffuser.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be more fully understood from the following description, when read together with the accompanying drawings in which:
FIGS. 1A , 1 B and 1 C show a number of embodiments of the diffuser in accordance with principles of the present invention;
FIGS. 2A , 2 B, 2 C, 2 D, 2 E, 2 F and 2 G show a number of embodiments of reflective surfaces associated with the embodiments of the diffuser shown in FIGS. 1A , 1 B and 1 C;
FIG. 3 shows the flat top diffraction profile of the surface of FIG. 2E ;
FIG. 4 shows the diffraction profile of a surface which approximates that of FIG. 2E ;
FIG. 5 shows the efficiency of light reflected for the structure of a preferred embodiment;
FIG. 6 shows light rays passing into and out the diffuser shown in FIG. 1A ;
FIG. 7 shows interference fringe planes and the etched surface in photoresist of an embodiment of the diffuser;
FIG. 8 shows a recording configuration of an embodiment of the diffuser that uses prism coupling;
FIG. 9 shows a method for copying from a volume diffuser into photoresist using prism coupling;
FIG. 10 shows a method for making a deep stepped wedge structure by using a prism coupling;
FIG. 11 shows a recording configuration for adding diffuse reflectance to a stepped wedge structure using prism coupling;
FIG. 12 shows a recording configuration for making a fine interference fringe structure parallel to a recording surface by means of prism coupling;
FIG. 13 shows interference fringe planes and the etched surface in photoresist of a deep stepped wedge structure; and
FIG. 14 shows a theoretical diffraction efficiency for a ten-step wedge grating structure with step height=250 nm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an improved diffuser having a high diffraction efficiency, broadband response and method for making the same.
Referring to FIG. 1A , an embodiment of the present invention as set forth herein comprises an improved diffuser including a reflective surface. The reflective surface may include a periodic wedge structure 1 , as shown in FIG. 1A , which reflects incident light 2 so that incident light 2 impinges on its surface 3 from an oblique angle, θ, into rays 4 which are approximately normal to its surface. These reflected rays 4 are contained within a small angular spread if the period p of the wedge is much greater than the wavelength of the light, λ. It is essential that the wedge angle (θ/2) for the surface 3 in FIG. 1A , be selected for the particular application (e.g. θ/2=15°) and that the period p be large compared to the wavelength (typically p>100λ). However, a period that is too large (>100 microns for example) may be visually annoying. If p is not much larger than λ, then incident light is scattered over other angles than that normal to the surface, as predicted by diffraction analysis. Furthermore the angle of scattering is then wavelength dependent, a feature that tends to detract from a desirable white diffusion pattern.
Referring further to FIG. 1B , the diffuser further includes a second structure 5 , which is disposed on the reflective surface. The second structure uniformly reflects incident rays across a prescribed angle, α. The surface 6 , which is shown in FIG. 1C , accepts an incoming oblique beam and scatters it uniformly over a range of angles, α. The scattered beam is centered on the normal to the structure with high efficiency. The geometry of the second structure 5-or scattering structure, may itself be periodic with period q, which is smaller than, equal to, or slightly larger than the wedge period p. Such examples of these structures are shown in FIG. 2 .
There are a variety of surface shapes that may be used for these structures. In the present embodiment, a shape for an element of the resulting combined surface can be described by the simple equation:
s ( x )= ax 2 +bx, (1)
where s(x) is the height of the surface and x is the coordinate on the surface, and an element is defined to span only one peak of the structure as is shown by the dimension q in FIG. 2 . The second term of equation 1 represents the tilted flat surface on wedge 3 . The first term is that of a quadratic, or parabolic reflector, either positive or negative.
Simple microlens arrays may be approximated by periodic, two-dimensional parabolic surface arrays and as such have been used successfully to create flat top diffraction patterns, i.e., uniform on-axis reflection (or transmission) over a specific range of angles. Theoretically, a plane wave of incident light is uniformly reflected from a periodic surface throughout a specific range of angles because it has a constant second derivative.
In general, the diffraction from any reflective phase surface element, s(x), can include:
f ( γ ) ≈ ( 1 / q ) ∫ - q / 2 q / 2 exp [ 2 ⅈ s ( x ) k ] exp [ - ⅈ k x γ ] ⅆ x ( 2 )
where γ is the reflection angle (radians), and k=2π/λ. For example, inserting for s(x) the parabolic function of equation 1, minus the wedge (sawtooth) portion, equation 2 yields
f
(
γ
)
∼
exp
[
ⅈ
k
γ
2
/
8
a
]
∫
t
1
t
2
exp
(
-
ⅈ
π
t
2
/
2
)
ⅆ
t
where
t
1
=
-
2
a
/
λ
q
+
1
/
2
a
λ
γ
and
t
2
=
+
2
a
/
λ
q
+
1
/
2
a
λ
γ
(
3
)
The integral in equation 3 is known as the Fresnel integral.
A typical plot of the amplitudes of the diffraction function of equation 3, is shown as the dashed curve 7 of FIG. 3 . Such curves are derived by data plotted in comu spirals, which are a convenient representation of these Fresnel integrals. As the size q of the element increases, the undulations evident at the extreme angles are reduced and the curve approaches the flat top distribution, which is desired for a preferred embodiment. However, this second component of the diffuser structure is periodic, the periodicity of which is q. For a periodic structure, the angular reflection distribution is punctuated by distinct peaks, the distance between which is proportional to the wavelength, λ, but is inversely proportional to the element size q. These peaks, which represent the various orders diffracted by the structure, are centered on the solid lines 10 shown in FIG. 3 . The presence of these periodic peaks need not be detrimental to the diffuser visibility if the period q is large compared to the wavelength, in which case they will be very close together, or if the incident light is specularly broad or spatially diffuse, thus obscuring them. For the examples in FIGS. 2A and 2B , the elements 11 and 12 are as large as that of the sawtooth, i.e., q=p, which is an extreme, and perhaps a desirable case, because it also reduces the undulations in the envelope (the dashed curve) as discussed before.
For parabolic structures, the diffraction function for elements 9 and 12 , shown in FIGS. 2B and 2D , is slightly different than that represented by equation 3 due to the inverted parabolic function. The applicable equation for that surface is
f
′
(
γ
)
∼
exp
[
ⅈ
k
γ
2
8
a
]
∫
t
3
t
4
exp
(
-
ⅈπ
t
2
/
2
)
ⅆ
t
where
t
3
=
-
2
a
/
λ
q
+
1
/
2
a
λ
γ
and
t
4
=
+
2
a
/
λ
q
+
1
/
2
a
λ
γ
(
4
)
The function f′ is the complex conjugate of f (i.e., f′=f*), a result that is evident from Fourier analysis, and so the amplitude of f′ is also represented by the dashed curve 7 of FIG. 3 . Here again, a periodic structure as shown in FIG. 2D , results in peaks represented by the solid lines 10 .
The structures 13 and 14 shown in FIGS. 2E and 2F combine the elements described by equation 3 and equation 4. After addition of suitable requisite phase terms (to account for lateral shifts and pedestal phase functions), these surface components, in the absence of the sawtooth component, give diffraction functions f(γ)
f (γ)˜ {exp[ ik γ/2 +ika 2 /2 ]f (γ)} (5)
where the symbol refers to the ‘real part’.
Because of the additional phase terms in equation 5, the dashed curve 10 of FIG. 3 represents the maximum diffraction that is achieved. Furthermore, peaks occur in this curve at half the distance of those for the cases discussed so far, since the period of this combined structure is now 2q versus q previously.
The surface shown in FIG. 2G is particularly interesting. Each element of FIG. 2A alternates with its inversion shown in FIG. 2B to produce a surface without discontinuities. Each element of width P, is an offset parabola when equation (1) is applied.
A surface which approximates the undulating parabolic surface of FIG. 2E (disregarding the sawtooth or wedge) is that which is represented by a sine or cosine function. Such a function can be constructed from the surface relief etching of two interfering, coherent beams. A function describing such a surface can include:
s ( x )≈ c sin (π x/q ) (6)
where 2c is the peak-to-peak excursion of the function, which is periodic in 2q. Inserting this function into equation 2 results in the diffraction function
f ( γ ) ≈ ∫ - q q exp · [ 2 ⅈ kc sin ( π x / q ) ] exp · [ - ⅈ k x γ ] ⅆ x ( 7 )
whose solution is
f (γ m )˜ J m (2 kc ) (8)
where J m is the m th order Bessel function of the first kind, m is an integer, and f(γ m ) represents the amplitude of the diffracted (or reflected) beams at the discrete angles of γ=mλ/p. In FIG. 4 , discrete values of |f(γ m )| 2 , for example 15 and 17, are plotted for the case in which the period 2q equals 38 λ, and the angular spread is approximately ±15 degrees. As can be seen in FIG. 4 , the profile 16 is not flat-topped, but peaks at specific angles ( 17 in FIG. 4 ). Such peaks tend to be reduced as the period, 2q, increases with respect to the wavelength, and a reasonable approximation to a flat top angular distribution is obtained.
Another method of producing a parabolic surface structure holographically is by the coherent interference of three laser beams in a layer of photoresist. If the sources of expanded light from each of the beams are arranged such that each source is approximately at the apex of an equilateral triangle, then the developed pattern in the photoresist will consist of a close-packed honeycomb array. By using suitable nonlinear etching characteristics of the photoresist, each honeycomb depression will develop in the shape of a paraboloid.
While the specific examples discussed so far relate to the reflection of incident light from a surface in air (i.e., n=1), the analysis also applies to cases in which the light is reflected from a surface that is covered, for example, by a plastic overcoating. In an embodiment, a reflective diffuser is provided, which includes a reflective surface that is embossed into the underside of a plastic sheet. In this embodiment, slight modifications to the analysis must be made, mainly in an alteration of the depth of the structure. (In equation 2, for example, s(x) becomes n s(x), where n is the index of refraction of the plastic). Also certain modifications would enable these devices to be used as transmission diffusers, rather than reflection diffusers.
Construction of surfaces discussed herein, and examples of which are shown in FIG. 1 , may be carried out by a number of processes. For well defined periodic functions like those shown in FIG. 1 , the surfaces can be formed by micro-machining or laser etching (e.g., MEMS processes). Alternatively the surfaces can be formed in two separate steps, which includes a first step that produces a periodic sawtooth structure such as that shown in FIG. 1A . Such a strictly periodic structure can, for example, be machined with great precision and cast into a number of materials. A second step, which adds the diffusion, or second component, may be added, for example in the following way. After appropriately coating the periodic sawtooth structure with a photoresist layer, the diffusing structure may be created by exposure to appropriate optical patterns and suitable processing of the photoresist thereafter. These optical patterns may be generated as an interference pattern of a number of coherent beams (the sine wave for example), the three-beam honeycomb pattern as described above, or as a result of scanning the photoresist surface with a focused intensity modulated light beam (as with a laser). Alternatively the optical pattern to which the photoresist is exposed may be a random function resulting, for example, from a laser illuminated diffuser. Randomly diffuse functions whose angular diffraction envelope are flat-topped, are usually difficult to create, unless unique processes are used.
The randomness may be achieved for example by using small portions of the prerequisite parabolic surface, which are randomly positioned but which on the aggregate cause reflected light to be more or less uniformly reflected over the desired angle.
Another process, described in the following, is a direct holographic method. The structure created by this method is different than that discussed so far, in that the period p is of the same order as the wavelength, λ, and thus diffraction effects become important. FIG. 5 illustrates the results of scalar diffraction theory, in which curve 18 is the major diffracted order, and the diffraction efficiency approaches 100% for the wavelength of interest. The step height h for the case shown in the FIG. 6 is equal to half the peak wavelength. For a central wavelength peak of 500 nm, the step height is thus 250 nm. This efficiency curve assumes that the surface is an ideal reflector, providing 100% efficiency at the peak wavelength. The efficiencies are also high for the entire visible spectral range, roughly ranging from approximately 85% at 400 nm in the violet to approximately 75% at 700 nm in the deep red. For this reason 500 nm is generally chosen to represent the center of the visible spectrum, and the surface structure is designed to operate at this wavelength. Note that there is a significant difference between the small scale structure represented by curve 18 , and the diffraction (or reflection) from the surface 3 of FIG. 1A . In FIG. 1A , the step height is many wavelengths, resulting in a diffraction efficiency of close to 100% for all visible wavelengths.
The parameters of FIG. 5 are chosen for the case of an air interface bordering the reflective sawtooth surface, similar to the situation shown in FIG. 1A . In the actual case, as with the situation of FIG. 1A , a preferable configuration is the coating of the surface with a protective layer, usually a clear plastic material 19 having an index of refraction, n=1.5, as in FIG. 6 . The tilt angle of the sawtooth 3 is chosen to provide an optimum viewing angle normal to the surface when light is incident at the proper offset angle, which for illustrative purposes can be 30 degrees. The wedge angle, β/2, can be selected for the overcoated surface as shown in FIG. 6 . Snell's Law, sin θ=n sin β, for light passing from air with index 1 into a medium with index n, yields, for an entrance angle from air of θ=30 degrees, an exit angle of β=19.47 degrees within the n=1.5 surface. The wedge tilt angle is half this value, or 19.47/2=9.74 degrees. The revised step height is h=250/n=250/1.5=166.67 nm. The period p is calculated from the grating equation for normal incidence, λ=p sin θ, or p=500/sin 30°=500/(1.5 sin 19.47°)=1000 nm=1.0 micron.
One method of creating the periodic wedge is by recording the interference of two counterpropagating laser beams, 20 and 21 in FIG. 7 , in a material 22 such as photoresist (n=1.7). The equation for spacing between the interference planes, d, can include:
d=λ o /[2 n sin (θ 0 /2)] (9)
where θ o is the half angle between the beams, and θ o is the laser recording wavelength. Thus the sine of the half angle is calculated in accordance with the following:
sin (θ o /2)=λ o /(2 nd )=441.6/[(2)(1.7)(169.11)=0.76803 (10)
where a recording wavelength of λ o =441.6 nm from a He—Cd laser and an index of refraction of n=1.7 for photoresist have been used. The spacing, d, has been calculated as
d=h /[cos(β/2)=166.67/[cos(9.74°)=169.11 nm (11)
Thus equation 10 yields an angle between the beams of θ o =100.36°. The interference fringe structure, 23 , is shown in FIG. 7 . This structure represents, after exposure, planes of maxima and minima of exposure intensity. When the photoresist plate is immersed in developer, etching or removal of the exposed photoresist proceeds from the top surface layer downward, the most exposed layers being removed preferentially over the least exposed layers. Ideally, the developer reaches the first zero exposure plane, which is represented by the dotted line 24 in FIG. 7 . The fringe planes lying beneath this plane are not affected by the development.
The preceding discussion represents the types of calculations that must be made in order to accurately form the fringe planes, and thus the sawtooth structure in a photoresist material, which is ultimately used as a master copy for mass production. In an embodiment, at least one of the beams, 20 and 21 , in FIG. 7 , can have some variation so as to create the desirable angular diffusion.
If there were no diffuse component to the beam, then the light diffracted from the sawtooth surface relief structure would, for incident white light, display all the spectral colors from violet to red, although each would be viewable from a different angle. But controlled diffusion is a requirement of this technology. Adding a diffuse component to obtain white light means adding a variation in the grating period p or in the slope of the sawtooth, so that all colors are mixed at the same diffraction angle. For example, taking the extremes of 400 nm for violet and 700 nm for red, the period p for these two colors is, respectively, p=400/sin 30°=800 nm (violet) and p=700/sin 30°=1400 nm (red) for the same diffraction angle of 30 degrees. If these extremes in the period for the visible spectrum are now present as part of the surface relief structure, then the diffraction angles for the design wavelength of 500 nm range from 38.68 degrees to 20.92 degrees, so that the total variation is 8.68+9.08=17.76 degrees. Since the diffuser is nominally designed to operate at an angular spread of plus or minus 15 degrees from the main diffraction angle of 30 degrees (or a total angular spread of 30 degrees), there is sufficient angular variation for mixing the entire visible spectrum sufficiently to produce white light.
A method for making the diffuse structure is to use a split beam holographic setup and a predetermined diffuse surface. This method allows for flexibility in the range of recording angles. The method does, however, require the fabrication of a diffuse plate with the requisite viewing angles, which is inserted into at least one of the two recording beams. In one configuration, as shown in FIG. 8 , requires the use of two prisms, 25 and 26 , with a liquid gate plate holder contacted by index matching liquid to both prisms. The calculated angles for beam 20 with respect to the normal, i.e., 49.56 degrees, is so large that it exceeds the critical angle, θ c , which is θ c =arcsin (1/n)=arcsin (1/1.7)=36.03 degrees. In the absence of a coupling medium, i.e., an air interface, all incident light would be at almost normal incidence to the face of the equilateral prism 25 . Beam 20 enters the face of the opposite prism 26 such that the angle of incidence to the photoresist material 22 from the n=1.5 glass layer is equal to 34.61 degrees. In this case the fringe spacing and tilt angle in the photoresist are as required for the example above. Because the angle of incidence of beam 20 does not exceed the critical angle into photoresist, an alternative scheme allows beam 20 to enter the tank directly from air at 58.43 degrees, A third alternative is one in which the rectangular plate holder tank is immersed in a large square tank filled completely with index matching liquid, thus eliminating the prisms altogether. While this latter method is relatively easy to implement it does require great care in allowing the index matching liquid to completely stabilize before making the recording.
Copying directly from a volume diffuser, as an alternative to the above, has many advantages. One advantage relates to a volume diffuser with the requisite offset and viewing angles, which can be efficiently produced holographically. Another advantage relates to the copying procedure, which is simpler than direct recording using a predetermined diffuse master, provided certain conditions are met. One of these conditions is that the peak wavelength of light diffracted from the master falls roughly into the center of the visible spectral range. Also the volume diffuser, which is used for copying, can have the proper angular spread to create an adequate viewing angle in the reflective mode.
A method of forming a structure like that of FIG. 7 from a volume hologram is shown in FIG. 9 . In order to form such a structure we assume that (1) photoresist 22 , is in intimate contact with the holographic diffuser 27 , (2) beam 21 is incident from outside, passing through the photoresist and into the volume hologram, (3) beam 20 is reflected from the interference planes 28 within the volume hologram back through the photoresist layer and (4) the index of refraction of the volume hologram has a typical value of n=1.5. Thus copying is done with only a single beam.
In order to create beams 20 and 21 at angles of 49.56 degrees and 30.08 degrees (as shown in FIG. 7 ), these beams, denoted as 29 and 30 in FIG. 9 , must have angles of 59.61 degrees and 34.61 degrees respectively in the lower index material 27 (n=1.5). Such beams exist in the volume reflective hologram 27 only if it contains fringe planes tilted at 12.5 degrees as shown in FIG. 9 , and whose spacing d=216.28 nm. This assumes that the copy wavelength is 441.6 nm. Light incident normally onto these fringe planes will reconstruct coherently at a wavelength of λ=2nh=2(1.5)(216.28)=648.85 nm, which is red. This result points out a fundamental characteristic of this type of construction; namely, that copying into a high index material at large incidence angles from a lower index master, requires that the master be red-shifted with respect to the copy. In other words, reconstruction of a blazed surface pattern producing light peaked in the green spectral region requires a master peaked in the red spectral region. Such a volume hologram can be easily made with a conventional holographic setup using red laser light (e.g., a Kr laser at 647 nm or a He—Ne laser at 633 nm) and either red-sensitive photographic emulsion or photopolymer. It is also possible to copy from a photopolymer master diffuser that is already tuned to the green spectral region, provided that certain steps are made to convert the diffuser to the red region. For example, the green Polaroid Imagix diffuser photopolymer can be copied directly into a DuPont 706 photopolymer, using either green laser light at near normal incidence or blue 441.6 nm laser light at a large angle of incidence. The DuPont material can then be tuned to the red region using DuPont CTF color tuning film, which essentially swells the photopolymer to a larger thickness, thereby increasing the spacing between the planes and changing the color from green to red.
Here again the angle for beam 20 in the photoresist is greater than the critical angle (49.56>36.03) and we must resort to coupling by means of a liquid gate. The photoresist plate is placed in a rectangular tank containing an index matching liquid for glass at n≈1.5 (e.g., xylene) that is liquid coupled to an equilateral prism, as shown in FIG. 9 .
Variations of the methods disclosed here can result in efficient directional diffusers. For example, with the first type disclosed, uniform angular spreading of the incident beam may be accomplished by a variation of either the period p or the slope θ/2 from sawtooth element to sawtooth element. However, such a procedure may require that the element size p be reduced (for example from 100λ to 10 or 20λ) so as to preserve the smooth visual texture of the diffuser. If the size p is too large, visible portions of the diffuser will not scatter into the observation direction.
A variation of the holographic method discussed herein, is the addition of a fine diffusing structure to a coarse wedge structure. This coarse wedge structure is of larger dimensions than that of the methods described in FIGS. 7 and 8 , and can be constructed in the following manner, as shown in FIG. 10 . Two beams enter the photoresist layer 33 that is coated onto a glass substrate 34 from the same side 35 at an oblique angle, such that the interference fringe structure 36 is coarse and inclined at some angle with respect to the surface. Prism coupling allows for a large degree of obliquity in a manner similar to that shown in FIG. 9 .
A diffuse component can be added in a second exposure step by contacting the photoresist layer 33 to a reflective diffuser 39 , as shown in FIG. 11 . In this case the incident beam 37 is totally reflected as a diffuse beam 40 that encompasses a range of angles. The contact can be done using either a liquid gate, or by reversing the plate and attaching the diffuser directly to the glass substrate and using a liquid gate between the photoresist and the prism. For this procedure to be effective, the resist should be coated to a several micron thick layer. The first exposure should be done at a laser wavelength for which absorption is large, for example 441.6 nm, so that the amount of reflected light is minimal. The second exposure should be done at a longer, less absorbing wavelength, for example 457.9 or 476 nm, so that the reflected beam is nearly equal in intensity to the incident beam.
An alternate technique adds a fine step structure to the coarse wedge of FIG. 10 , in place of the fine diffusing structure. With this technique the second exposure uses two beams that enter the photoresist from opposite sides so that the interference fringe structure is fine and parallel to the surface. This is also done by prism coupling, using a single beam 37 that is totally reflected that interferes with itself, as shown in FIG. 12 , with the fine fringe structure designated as 38 . For this exposure the photoresist plate is reversed so that the surface 35 faces out. When the photoresist is developed after the composite exposure, the resulting structure is a deep wedge-shaped grating that has a fine stepped grating superimposed onto it ( FIG. 13 ).
The diffraction efficiency for a ten-level structure is shown in FIG. 14 and includes the spectral distribution for diffracted orders +2, +1, 0, −1, and −2. Also included in this plot is the spectral distribution for a single-step blazed grating, which is identical to FIG. 5 . It is clearly evident that the spectral distribution for the single-step shallow blazed grating forms an envelope for the ten-level deep stepped grating. The number of orders that appear under this envelope decreases as the number of levels is reduced, but their individual spectral width increases.
As can be seen from FIG. 14 , the diffraction is specularly discrete, allowing only narrow band color components to be observed at any given viewing angle. In order to avoid this often undesirable result, the photoresist can be exposed in narrow adjacent stripes that yield, for example, red, blue, and green light diffracted at the same angle to produce white. The proper angle for light diffracted from the stepped grating structure is determined by the periodicity of the coarse wedge grating, and that periodicity depends, in turn, on the oblique angle that the interference fringe structure makes with respect to the photoresist surface.
Another variation on this method consists of first making a wedge grating structure of large periodicity and adding the step structure or diffuse structure to it holographically. In this configuration, it is similar to the structure shown in FIG. 1 c . For the step structure, the procedure consists of coating the wedge structure with a thin, uniform layer of photoresist, which can be done either by dip coating or by spin coating. The coated wedge surface is then immersed in an index-matching liquid gate that is optically contacted to an equilateral glass prism, as described above. The step structure is made by exposing to a totally reflecting beam of laser light that is coupled to a diffuse surface, also described above. With this method many more diffracted orders are obtained than with the totally holographic method described above, due to the much greater depth of the preformed structure compared to that obtained holographically, but with diffuse mixing the diffracted light appears white.
The discussion has focused on devices that uniformly scatter light through a solid angle. But in some applications it may be desirable to achieve non-uniform scattering. One can modify the processes to create blazed diffusers that have a wide range of scattering properties.
Both categories of structures have been described in the foregoing in reference to their scattering properties in one dimension only. That is, the emphasis has been on showing how an incident beam whose obliquity to the surface (i.e., θ=30°) is scattered uniformly throughout an angle α, as in FIG. 1 . But in the other direction, which follows the coordinate going into the paper in all of the FIGS., the illumination beam 2 (See FIG. 1 ) is assumed to have no obliquity, but to impinge perpendicular to the surface. In order to obtain a uniform angular diffusion, there is a similar requirement for scattering over an angle of α in this dimension also, albeit without an offset θ. For the first category of diffuser described here, the surface profile into the paper for the surface of FIG. 2 would contain the parabolic component, thus providing a diffuser, each portion of which scatters uniformly throughout a pyramidal solid angle which is offset from the incident illumination by angle θ. Similarly if a beam, which is randomly diffuse throughout a cone of angles, is reconstructed as beam 20 in FIG. 9 from the photopolymer hologram 27 , the resulting aluminized diffuser will scatter incoming light throughout a conical solid angle, offset by angle θ.
Having thus described at least one illustrative embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the scope and spirit of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting.
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A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.
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TECHNICAL FIELD
The present invention relates to an Li 2 O—Al 2 O 3 —SiO 2 -based glass (LAS-type float glass) formed by a float process and to an LAS-type crystallized glass formed by crystallizing the LAS-type float glass.
BACKGROUND ART
A crystallized glass is a material exhibiting unique characteristics owing to various crystals precipitating in the glass. For example, an LAS-type crystallized glass formed by precipitating crystals of a β-quartz solid solution, β-spodumene, or the like in the glass exhibits extremely low expansion or minus expansion, and hence exhibits high mechanical strength and high thermal shock resistance compared with ordinary glasses. Thus, the LAS-type crystallized glass is used for a front glass for a kerosine stove, a wood stove, or the like, a substrate for a high-tech product such as a substrate for a color filter or an image sensor, a setter for firing an electronic part, a tray for a microwave oven, a top plate for induction heating cooking, a window glass for a fire protection door, or the like. For example, Patent Documents 1 to 3 disclose a transparent LAS-type crystallized glass formed by precipitating a metastable β-quartz solid solution (Li 2 O.Al 2 O 3 .nSiO 2 [provided that n≧2]) as a main crystal and a white opaque LAS-type crystallized glass formed by precipitating a stable β-spodumene solid solution (Li 2 O.Al 2 O 3 .nSiO 2 [provided that n≧4]) obtained by further subjecting a β-quartz solid solution to higher temperature treatment.
By the way, a crystallizable glass, which is mother glass of those crystallized glasses, is generally formed into a plate shape by a roll-out process involving sandwiching a molten glass directly with two refractory rollers and drawing the molten glass. However, the surfaces of the molten glass are directly in contact with the surfaces of the refractory rollers, and hence the roll-out process is apt to cause problems such as imprint of the surface shapes of the refractory rollers and swelling on the surfaces of the glass. Further, the molten glass is forcibly formed into a plate shape by the refractory rollers while being cooled, and hence unevenness is apt to occur. As a result, obtaining a plate glass having a uniform quality is difficult. Thus, a plate glass formed by the roll-out process has involved a problem that more time and more cost are required for its production because the surfaces of the glass need to be subjected to machine polishing to obtain smooth and flat surfaces.
Note that in the roll-out process, the width of a glass plate is restricted depending on the length of the refractory roller, and it is difficult to control the molten glass so that the molten glass extends uniformly in the longitudinal direction of the refractory roller, resulting in easy reduction in quality. Thus, producing a larger glass plate by the roll-out process is difficult.
On the other hand, a float process (float forming process) has been conventionally proposed as another forming process. The float process is good in production efficiency because glass can be formed into a large plate shape, and can provide glass having a high surface quality. The float process is a process involving feeding a molten glass onto a bath of a molten metal bath such as a molten metal tin bath, to thereby form the molten glass into a plate shape. To be specific, a molten glass is fed onto a molten metal bath in a float forming chamber in which a reducing atmosphere is maintained, thereby producing a plate-shaped glass (glass ribbon) having an equilibrium thickness, and the glass ribbon is then drawn on the molten metal bath so as to have a predetermined thickness, to thereby form a plate glass. The float process has been widely adopted as a process of continuously producing large quantities of plate glass products that require a high surface quality (see, for example, Patent Document 4 or 5).
CITATION LIST
Patent Document 1: JP 39-21049 B
Patent Document 2: JP 40-20182 B
Patent Document 3: JP 01-308845 A
Patent Document 4: JP 2001-354429 A
Patent Document 5: JP 2001-354446 A
SUMMARY OF INVENTION
Technical Problem to be Solved
In the case where an LAS-type float glass is formed by using a float process, a molten glass is kept in a float forming chamber with high temperature for about 5 to 30 minutes until the molten glass becomes a glass ribbon having an equilibrium thickness. Thus, the devitrification of glass is apt to occur in the float process, compared with in a roll-out process involving forming a molten glass forcibly into a plate shape by cooling the molten glass for a short time from several seconds to several tens of seconds. Further, undesirable other crystals derived from SnO 2 , such as cassiterite, may be precipitated in a glass surface layer. Alternatively, glass may be reduced with a reducing gas in the float forming chamber. As a result, a metal colloid such as an Sn colloid may be formed, resulting in surface coloring or a surface defect.
Thus, the resultant LAS-type float glass not only may be inferior in surface quality and outer appearance, but also may break because of the difference in a thermal expansion coefficient between a devitrified part and glass in the glass surface layer or of the surface defect. Further, even if a crystallizable glass without any break is obtained, the crystallizable glass may break in a subsequent heat treatment step (crystallization step).
In view of the above-mentioned problems in the prior arts, an object of the present invention is to provide an LAS-type float glass in which devitrification in a glass surface layer caused during forming by a float process is suppressed and surface coloring and a surface defect are reduced, and an LAS-type crystallized glass formed by crystallizing such the LAS-type float glass.
Solution to Problem
The inventors of the present invention have made various studies. As a result, the inventors have found that an LAS-type float glass and an LAS-type crystallized glass formed by crystallizing the LAS-type float glass have a high content of SnO 2 in a devitrified portion in each of their surface layers. Thus, the inventors have found that the problems can be solved by controlling the content of SnO 2 in the glass surface layer. Consequently, the finding is proposed as the present invention.
That is, the present invention relates to an LAS-type float glass, which is substantially free of As 2 O 3 and/or Sb 2 O 3 and precipitates a β-quartz solid solution or a β-spodumene solid solution as a main crystal by heat treatment, in which, when C 1 [mass %] represents a content of SnO 2 at a glass surface, C 0 [mass %] represents a content of SnO 2 at a depth of 0.5 mm from the glass surface, and k [mass %/mm] represents an SnO 2 concentration gradient defined by k=(C 1 -C 0 )/0.5, the LAS-type float glass satisfies relationships of K≦2 and C 0 ≦0.8 with respect to at least one surface thereof. Here, the term “LAS-type float glass” refers to a crystallizable glass which is formed by a float process and precipitates an Li 2 O—Al 2 O 3 —SiO 2 -based crystal as a main crystal by heat treatment. Further, the phrase “content C 1 of SnO 2 at a glass surface” refers to the content of SnO 2 at a depth of 1 μm from the glass surface.
It has been found that the LAS-type float glass exhibits an approximately constant value in the content of SnO 2 at a depth of more than 0.5 mm from the glass surface, but a concentration gradient occurs as the content of SnO 2 increases almost monotonically from the depth of 0.5 mm in the glass to the glass surface. This is derived from the fact that metal tin vapor is diffused into a glass surface layer in a float forming chamber. Here, the content of SnO 2 at the depth of 0.5 mm in the glass almost corresponds to the content of SnO 2 as a fining agent contained in the glass.
In the present invention, the SnO 2 concentration gradient k [mass %/mm] from the depth of 0.5 mm from the glass surface to the glass surface and the content C 0 [mass %] of SnO 2 at the depth of 0.5 mm from the glass surface are defined as described above. As a result, during float forming, devitrification in a glass surface layer can be suppressed, and moreover, it is possible to suppress undesirable other crystals of SnO 2 and coloring or a surface defect caused by a metal colloid. Thus, the resultant LAS-type float glass has a uniform quality and an excellent surface quality, and has an advantage that its production cost is low because the surface of the glass is not required to be subjected to machine polishing. Further, occurrence of a surface crack or break of the glass can be prevented in the subsequent crystallization step, and problems will not occur such that the outer appearance is damaged and the thermal and mechanical strengths are reduced remarkably.
Note that As 2 O 3 and Sb 2 O 3 are environmental load substances, and are reduced by a reducing atmosphere in a float forming chamber to produce metal colloids on a glass surface. As a result, undesired coloring is apt to occur remarkably in a glass surface layer. The LAS-type crystallized glass of the present invention is substantially free of As 2 O 3 and/or Sb 2 O 3 as a fining agent (agents), and hence a coloring problem derived from those components can be solved. Further, a demand from an environmental aspect that has been increasing more and more in recent years can be also coped with. Here, the phrase “substantially free of As 2 O 3 and/or Sb 2 O 3 ” means that As 2 O 3 and/or Sb 2 O 3 are/is not added intentionally as a glass material (materials), and refers to a level at which As 2 O 3 and/or Sb 2 O 3 are/is contained as an impurity (impurities). To be specific, the phrase refers to the fact that the content of each of those components is 0.1 mass % or less in glass composition.
Second, the LAS-type float glass of the present invention preferably comprises a composition containing, in terms of mass %, 55 to 75% of SiO 2 , 17 to 27% of Al 2 O 3 , 2 to 5% of Li 2 O, 0 to 1.5% of MgO, 0 to 1.5% of ZnO, 0 to 5% of BaO, 0 to 2% of Na 2 O, 0 to 3% of K 2 O, 0 to 4% of TiO 2 , 0 to 2.5% of ZrO 2 , 0 to 0.8% of SnO 2 , and 2 to 6% of TiO 2 +ZrO 2 +SnO 2 .
Third, an LAS-type crystallized glass of the present invention is formed by crystallizing anyone of the LAS-type float glasses as above.
Fourth, the present invention relates to an LAS-type crystallized glass, which is formed by crystallizing an LAS-type float glass, is substantially free of As 2 O 3 and/or Sb 2 O 3 , and comprises a β-quartz solid solution or a β-spodumene solid solution as a main crystal, wherein, when C 1 [mass %] represents the content of SnO 2 at a glass surface, C 0 [mass %] represents the content of SnO 2 at a depth of 0.5 mm from the glass surface, and k [mass %/mm] represents an SnO 2 concentration gradient defined by k=(C 1 -C 0 )/0.5, the LAS-type float glass satisfies relationships of K≦2 and C 0 ≦0.8 with respect to at least one surface thereof.
In the LAS-type crystallized glass of the present invention, the SnO 2 concentration gradient k [mass %/mm] from the glass surface to the depth of 0.5 mm from the glass surface and the content C 0 [mass %] of SnO 2 at the depth of 0.5 mm from the glass surface are defined as described above. As a result, it is possible to suppress undesirable other crystals of SnO 2 and coloring or a surface defect caused by a metal colloid. Thus, the LAS-type crystallized glass of the present invention has uniform transparency and an excellent surface quality, and has an advantage that its production cost is low because the surface of the glass is not required to be subjected to machine polishing.
Fifth, the present invention relates to a method of producing an LAS-type float glass, comprising a step of forming a molten glass into a plate shape on a bath of a molten metal, wherein, in the step of forming the molten glass, the ratio of an area of the molten glass accounting for on a surface of the molten metal is equal to or more than 40%.
In a float forming chamber, when metal tin vapor and oxygen react with each other to produce SnO 2 and this metal oxide is then diffused into a glass surface layer, undesired devitrification is induced in the glass surface layer. According to the production method of the present invention, the area of the molten glass accounting for on the surface of the molten metal such as molten tin is increased during glass forming, to thereby reduce the exposure area of the molten metal. As a result, it becomes possible to reduce the pressure of metal vapor volatilizing from the molten metal in the float forming chamber. Consequently, devitrification in the glass surface layer caused by the diffusion of SnO 2 into the glass surface layer can be suppressed.
DESCRIPTION OF EMBODIMENTS
In an LAS-type float glass and LAS-type crystallized glass of the present invention, each glass surface layer has an SnO 2 concentration gradient k of 2 mass %/mm or less, preferably 1.6 mass %/mm or less, more preferably 1.2 mass %/mm or less. The lower limit of the SnO 2 concentration gradient k is not particularly limited, but realistically is 0.01 mass %/mm or more.
Note that the SnO 2 concentration gradient in a glass surface may occur not only in the upper glass surface (surface not being in contact with a molten metal) in float forming but also in the lower glass surface (surface being in contact with the molten metal) in float forming. That is, as SnO 2 produced by oxidation of the molten metal is diffused into the glass surface layer, the SnO 2 concentration gradient may also occur in the lower glass surface. Thus, the LAS-type float glass of the present invention is characterized in that the SnO 2 concentration gradient with respect to one surface or both surfaces thereof falls within the range described above. Note that the SnO 2 concentration gradient k in the lower glass surface may exceed 2 mass %/mm.
Further, the content C 0 of SnO 2 at a depth of 0.5 mm from the glass surface is 0.8 mass % or less, preferably 0.6 mass % or less, more preferably 0.4 mass % or less. The lower limit of the content C 0 of SnO 2 is not particularly limited, but is preferably 0.01 mass % or more in order that a sufficient fining effect and a sufficient crystallization-enhancing effect are obtained.
When the SnO 2 concentration gradient k exceeds 2 mass %/mm or when the content C 0 of SnO 2 at the depth of 0.5 mm from the glass surface exceeds 0.8 mass %, devitrification tends to occur in glass or undesirable other crystals derived from SnO 2 tend to occur, during float forming. Moreover, coloring due to a metal colloid is also apt to occur. In particular, when the SnO 2 concentration gradient k exceeds 2 mass %/mm, devitrification in the glass surface layer becomes remarkable.
The LAS-type float glass of the present invention preferably comprises a composition containing, in terms of mass %, 55 to 75% of SiO 2 , 17 to 27% of Al 2 O 3 , 2 to 5% of Li 2 O, 0 to 1.5% of MgO, 0 to 1.5% of ZnO, 0 to 5% of BaO, 0 to 2% of Na 2 O, 0 to 3% of K 2 O, 0 to 4% of TiO 2 , 0 to 2.5% of ZrO 2 , 0 to 0.8% of SnO 2 , and 2 to 6% of TiO 2 +ZrO 2 +SnO 2 . The reasons for limiting the glass composition thereto are described below.
SiO 2 is a component that forms the skeleton of glass and constitutes an LAS-type crystal. The content of SiO 2 is 55 to 75%, preferably 58 to 72%, more preferably 60 to 70%. When the content of SiO 2 is less than 55%, the thermal expansion coefficient is apt to be high. On the other hand, when the content of SiO 2 is more than 75%, glass melting tends to be difficult.
Al 2 O 3 is also a component that forms the skeleton of glass and constitutes an LAS-type crystal as SiO 2 is. The content of Al 2 O 3 is 17 to 27%, preferably 17 to 24%. When the content of Al 2 O 3 is less than 17%, the chemical durability lowers and glass is apt to devitrify. On the other hand, when the content of Al 2 O 3 is more than 27%, the viscosity of glass becomes too large, and hence glass melting tends to be difficult.
Li 2 O is a component that constitutes an LAS-type crystal, gives a significant influence to the crystallinity, and has a function of lowering the viscosity of glass. The content of Li 2 O is 2 to 5%, preferably 2.5 to 5%, more preferably 3 to 5%. When the content of Li 2 O is less than 2%, the crystallinity of glass becomes weak and the thermal expansion coefficient is apt to be high. In addition, in a case where transparent crystallized glass is aimed to be obtained, a crystal substance is apt to develop white turbidity, and in a case where white opaque crystallized glass is aimed to be obtained, obtaining desired whiteness is apt to be difficult. On the other hand, when the content of Li 2 O is more than 5%, the crystallinity becomes too strong, and hence glass is apt to devitrify during float forming. In particular, obtaining a metastable β-quartz solid solution becomes difficult, and hence a crystal substance tends to develop white turbidity. As a result, obtaining transparent crystallized glass is apt to be difficult.
MgO, ZnO, BaO, Na 2 O, and K 2 O have a function of controlling the precipitation amount of LAS-type crystals.
The content of MgO is 0 to 1.5%, preferably 0.1 to 1%. When the content of MgO is more than 1.5%, the crystallinity becomes strong. As a result, the thermal expansion coefficient tends to be high. In addition, MgO tends to accelerate coloring caused by Fe 2 O 3 impurities in the presence of TiO 2 . Further, glass is apt to devitrify because of undesired crystal precipitation at the time of forming.
The content of ZnO is 0 to 1.5% or preferably 0.1 to 1%. When the content of ZnO is more than 1.5%, the crystallinity becomes strong. As a result, ZnO tends to accelerate coloring caused by Fe 2 O 3 impurities in the presence of TiO 2 .
The content of BaO is 0 to 5%, preferably 0.3 to 4%, more preferably 0.5 to 3%. When the content of BaO is more than 5%, the precipitation of LAS-type crystals tends to be inhibited and the thermal expansion coefficient is apt to be high. In addition, a crystal substance tends to develop white turbidity. As a result, obtaining transparent crystallized glass is apt to be difficult.
The content of Na 2 O is 0 to 2%, preferably 0 to 1.5%, more preferably 0.1 to 1%. When the content of Na 2 O is more than 2%, glass is apt to devitrify during forming and the thermal expansion coefficient is apt to be high. In addition, a crystal substance tends to develop white turbidity. As a result, obtaining transparent crystallized glass is apt to be difficult.
The content of K 2 O is 0 to 3%, preferably 0 to 2%, more preferably 0.1 to 1.5%. When the content of K 2 O is more than 3%, the crystallinity becomes weak and the thermal expansion coefficient is apt to be high. In addition, a crystal substance tends to develop white turbidity. As a result, obtaining transparent crystallized glass is apt to be difficult.
TiO 2 is a component that functions as a nucleating agent. The content of TiO 2 is 0 to 4%, preferably 0.3 to 3%, more preferably 0.5 to 2%. When the content of TiO 2 is more than 4%, coloring caused by Fe 2 O 3 impurities becomes remarkable and glass is apt to devitrify at the time of forming.
ZrO 2 is also a component that has a function as a nucleating agent. The content of ZrO 2 is 0 to 2.5%, preferably 0.1 to 2.2%. When the content of ZrO 2 is more than 2.5%, glass melting becomes difficult and glass is apt to devitrify at the time of forming.
SnO 2 is a component that has a fining effect and a crystallization-enhancing effect. The content of SnO 2 is 0 to 0.8%, preferably 0.01 to 0.6%, more preferably 0.1 to 0.4%. When the content of SnO 2 is more than 0.8%, glass is apt to devitrify, and devitrification is apt to occur in a glass surface layer particularly during float forming. In addition, coloring caused by Fe 2 O 3 impurities becomes remarkable.
Further, SnO 2 has a function as a nucleating agent forming a ZrO 2 —TiO 2 —SnO 2 -based crystal nucleus together with TiO 2 and ZrO 2 , thereby providing a minute crystal. The total content of TiO 2 , ZrO 2 , and SnO 2 is 2 to 6%, preferably 2.5 to 5%, more preferably 2.5 to 4%. When the total content of those components is less than 2.5%, obtaining dense crystals becomes difficult. When the total content of those components is more than 6%, glass is apt to devitrify.
In addition, it is also possible to add Cl as a fining agent at 0 to 2% or preferably 0.1 to 1%. Cl has a function of enhancing the fining effect of SnO 2 . Thus, combined use of SnO 2 and Cl as a fining agent is preferred because the combined use provides a very good fining effect. Note that when the content of Cl is more than 2%, the chemical durability tends to lower.
As described above, in general, As 2 O 3 or Sb 2 O 3 used as a fining agent is reduced directly by a reducing atmosphere in a float chamber to produce a metal colloid of As or Sb. As a result, undesired coloring tends to occur remarkably in a glass surface layer. Grinding and polishing are required to remove the undesirable coloring, which is disadvantageous in terms of the steps and cost. A sulfate such as sodium sulfate, a chloride (Cl) such as sodium chloride, cerium oxide, or the like can be used as a fining agent that hardly causes coloring due to a reducing action. Alternatively, the fining effect may be obtained by carrying out defoaming under reduced pressure, or by heating at a temperature, for example, exceeding 1780° C. during melting glass.
In addition to the above, P 2 O 5 may be contained as a component for improving the crystallinity of glass. The content of P 2 O 5 is 0 to 7%, preferably 0 to 4%, more preferably 0 to 3%. When the content of P 2 O 5 is more than 7%, the thermal expansion coefficient becomes too high and a crystal substance tends to develop white turbidity. As a result, obtaining transparent crystallized glass is apt to be difficult.
The LAS-type crystallized glass of the present invention preferably comprises a composition containing, in terms of mass %, 55 to 75% of SiO 2 , 17 to 27% of Al 2 O 3 , 2 to 5% of Li 2 O, 0 to 1.5% of MgO, 0 to 1.5% of ZnO, 0 to 5% of BaO, 0 to 2% of Na 2 O, 0 to 3% of K 2 O, 0 to 4% of TiO 2 , 0 to 2.5% of ZrO 2 , 0 to 0.8% of SnO 2 , and 2 to 6% of TiO 2 +ZrO 2 +SnO 2 . The reasons for limiting the glass composition thereto are the same as those described above.
The thermal expansion coefficient of the LAS-type crystallized glass of the present invention in a temperature range of 30 to 750° C. is preferably −10 to 30×10 −7 /° C., more preferably −10 to 20×10 −7 /° C. When the thermal expansion coefficient falls within the range, glass excellent in thermal shock resistance is provided. Note that in the present invention, the thermal expansion coefficient refers to a value obtained by measurement with a dilatometer.
The thicknesses of the LAS-type float glass and LAS-type crystallized glass of the present invention are not particularly limited, and are appropriately selected depending on their applications. For example, the thicknesses of the LAS-type float glass and LAS-type crystallized glass of the present invention can be set to 1 to 8 mm, more preferably 1.5 to 6 mm, particularly preferably 2 to 5 mm.
According to the present invention, a large plate glass can be obtained. For example, it is possible to obtain an LAS-type float glass or an LAS-type crystallized glass each having a plate width of 2500 mm or more, or further, of 3000 mm or more.
Next, methods of producing the LAS-type float glass and LAS-type crystallized glass of the present invention are described.
First, raw glass materials are compounded so as to have predetermined composition. After the raw glass materials are mixed uniformly, the mixture of the raw glass materials is melted in a melting furnace. Here, in a case where one of SnO 2 and Cl is used or both of them are used in combination as a fining agent, melting is carried out under the conditions of 1550 to 1780° C., preferably 1580 to 1750° C. and 4 to 24 hours or preferably 12 to 20 hours. Note that in a case where a chemical fining agent, for example, SnO 2 , a sulfate such as sodium sulfate, a chloride such as sodium chloride, or cerium oxide, is not used, melting may be carried out under the conditions of 1780° C. to 1880° C. and 10 to 35 hours, or defoaming may be carried out under reduced pressure during melting glass, in order to obtain a fining effect.
Next, the molten glass is formed into a plate shape by a float process. To be specific, in a float forming chamber in which a reducing atmosphere is maintained with a reducing gas, the molten glass is poured on a molten metal such as molten metal tin or a molten metal tin alloy, and is extended to be flat until an equilibrium thickness is obtained, to thereby yield a molten glass ribbon. Subsequently, the molten glass ribbon is drawn while being pulled until a predetermined thickness is obtained.
Note that the float forming chamber includes an upper casing and a lower casing each made of metal and equipped with a refractory, and there are provided an outlet, forming equipment for pulling a molten glass, and the like between the upper casing and the lower casing.
In the float forming chamber, when metallic tin vapor and oxygen react with each other to produce SnO 2 , followed by the diffusion of SnO 2 into a glass surface layer, the content C 1 of SnO 2 at a glass surface and an SnO 2 concentration gradient k tend to be larger. As a result, undesired devitrification is induced in the glass surface layer. Thus, the devitrification in the glass surface layer can be suppressed by using the method described below.
In order to reduce the pressure of metal tin vapor volatilizing from the molten metal in the float forming chamber, for example, it is preferred that the exposure area of the molten metal be decreased compared with the area of the molten glass (the area of the molten glass accounting for on the surface of the molten metal be increased) by adjusting the amount of glass supplied into the float forming chamber. To be specific, the ratio of the area of the molten glass accounting for on the surface of the molten metal is preferably 40% or more, more preferably 50% or more, still more preferably 60% or more. If the ratio of the area of the molten glass accounting for on the surface of the molten metal is less than 40%, the metal tin vapor acts on the glass surface layer during forming process. As a result, other crystals of SnO 2 may precipitate, devitrification may be induced by the diffusion of SnO 2 into the glass surface layer, or undesired surface defects such as a dent may be caused because metal tin droplets directly drop on the molten glass. Note that the upper limit of the ratio is not particularly limited. However, the ratio is set to 100% or less, more preferably 90% or less, particularly preferably 80% or less, depending on the dimension of the float forming chamber and a target width of a glass plate.
A reducing gas is preferably supplied into the float forming chamber in order to prevent oxidation of the molten metal and oxidation of the metal tin vapor in the float forming chamber. Used as the reducing gas is preferably a mixed gas of 90 to 99.5% N 2 and 0.5 to 10% H 2 and more preferably a mixed gas of 92 to 99% N 2 and 1 to 8% H 2 , in terms of vol %.
In addition, it is preferred that a reducing gas containing metal tin vapor be removed from the float forming chamber by discharging the reducing gas under reduced pressure from an outlet provided in the float forming chamber.
In order to reduce the influence of metal tin vapor on a glass ribbon, it is preferred that the distance between the ceiling made of a refractory provided in the upper casing made of metal in the float forming chamber and a molten glass ribbon be as short as possible. To be specific, the distance between the ceiling of the float forming chamber and the molten glass ribbon is preferably 80 cm or less, more preferably 60 cm or less. When the distance between the ceiling of the float forming chamber and the molten glass ribbon exceeds 80 cm, a difference in temperature between the vicinity of the molten glass ribbon and the vicinity of the ceiling is apt to occur in the float forming chamber. As a result, metal tin vapor is cooled to produce metal tin droplets, which drop on the glass ribbon, probably leading to surface defects.
After the molten glass is formed into a plate shape, the plate-shaped glass is lifted out at 700 to 850° C. from the molten metal in the float forming chamber, followed by annealing, to thereby yield an LAS-type float glass.
Subsequently, the LAS-type float glass is subjected to heat treatment (crystallization treatment) to yield an LAS-type crystallized glass. To be specific, first, the LAS-type float glass is kept at 700 to 800° C. for 1 to 4 hours to form a nucleus. Next, the resultant glass is subjected to heat treatment at 800 to 950° C. for 0.5 to 3 hours to precipitate a β-quartz solid solution in the case of converting to transparent crystallized glass, or the resultant glass is subjected to heat treatment at 1050 to 1250° C. for 0.5 to 2 hours to precipitate a β-spodumene solid solution in the case of converting to white opaque crystallized glass. As a result, an LAS-type crystallized glass is yielded.
The resultant LAS-type crystallized glass is used for various applications after post-processing such as cutting, polishing, or bending processing is performed or after painting or the like is performed on the surface.
EXAMPLES
Hereinafter, the LAS-type float glass and LAS-type transparent crystallized glass of the present invention are described in detail by examples. However, the present invention is not limited to those examples.
Glasses of Examples and Comparative Examples were produced as described below. Note that Sample Nos. 1 to 5, 8, and 9 are Examples, and Sample Nos. 6, 7, and 10 to 13 are Comparative Examples.
TABLE 1
Sample No.
1 to 6
7 to 10
11 and 12
Glass
SiO 2
65.6
65.7
64.8
composition
Al 2 O 3
22.14
22.2
22.2
[mass %]
Li 2 O
4.2
4.2
4.2
Na 2 O
0.5
0.5
0.5
K 2 O
0.3
0.3
0.3
BaO
1.5
1.5
1.5
TiO 2
2.0
2.0
2.0
ZrO 2
2.2
2.2
2.2
P 2 O 5
1.4
1.4
1.4
SnO 2
0.16
0.9
Total
100.0
100.0
100.0
Melting temperature-
1550° C.-9 h
1550° C.-9 h
1550° C.-9 h
time
1650° C.-12 h
1650° C.-18 h
1650° C.-12 h
TABLE 2
Sample No.
1
2
3
4
5
6
7
Ratio of exposure area
8:2
7:3
6:4
5:5
4:6
3:7
2:8
(glass:metal tin)
Content
Glass
0.22
0.27
0.31
0.62
1.06
1.30
1.55
of SnO 2
surface C 1
(mass %)
Glass
0.16
0.16
0.16
0.16
0.16
0.16
0.16
inside C 0
SnO 2 concentration
0.12
0.22
0.30
0.92
1.80
2.28
2.78
gradient k (mass %/mm)
Depth of
0
0
0
0.2
0.4
1.5
wholly
devitrification (mm)
devit-
rified
Transparency
⊚
⊚
⊚
◯
◯
X
X
TABLE 3
Sample No.
8
9
10
11
Ratio of exposure area
7:3
5:5
3:7
2:8
(glass:metal tin)
Content
Glass
0.28
0.71
1.10
1.52
of SnO 2
surface C 1
(mass %)
Glass inside
0
0
0
0
C 0
SnO 2 concentration
0.56
1.42
2.20
3.04
gradient k (mass %/mm)
Depth of
0
0.1
1.0
wholly
devitrification (mm)
devitrified
Transparency
⊚
◯
X
X
TABLE 4
Sample No.
12
13
Ratio of exposure area
3:7
2:8
(glass:metal tin)
Content of
Glass surface C 1
1.92
2.25
SnO 2 (mass %)
Glass inside C 0
0.9
0.9
SnO 2 concentration gradient k
2.04
2.70
(mass %/mm)
Depth of devitrification (mm)
—
—
Transparency
X
X
First, each raw glass material was prepared so as to have each composition shown in Table 1. The each raw glass material was introduced into a platinum crucible and melted by using an electric furnace under each condition described in Table 1. Note that, in Table 1, the phrase “1550° C.-9 h, 1650° C.-12 h” means that a raw glass material was melted at 1550° C. for 9 hours and was then melted at 1650° C. for 12 hours, for example.
Next, the resultant molten glass was fed on a carbon surface plate and was formed by using a stainless steel roller so as to have a thickness of 7 mm. After that, the formed glass was cooled to room temperature by using an annealing furnace in which temperature had been set to 700° C. Thus, material glass for float forming was produced.
Subsequently, the material glass for float forming was used to carry out float forming as described below.
Metal tin was introduced into a carbon container and the material glass for float forming was placed on the metal tin, and then heat treatment was carried out in an electric furnace internally having a reducing atmosphere of 98 vol % nitrogen and 2 vol % hydrogen. In the heat treatment, temperature was increased at a rate of 20° C./min from room temperature to 1450° C., kept at 1450° C. for 10 minutes, then decreased at a rate of 20° C./min to 1250° C., and further decreased at a rate of 50° C./min from 1250° C. to 820° C. In the heat treatment, the amount of glass was adjusted so that the ratio of the area of the molten glass and the area of the exposure portion of the metal tin reached each value shown in Tables. After that, the resultant formed glass was taken out of the electric furnace and cooled to room temperature by using an annealing furnace. Thus, an LAS-type float glass was obtained.
The resultant LAS-type float glass was subjected to heat treatment at 780° C. for 3 hours and then at 870° C. for 1 hour by using an electric furnace, to thereby obtain an LAS-type crystallized glass. In any of the resultant LAS-type crystallized glasses, a β-quartz solid solution was precipitated as a main crystal and the average linear thermal expansion coefficient was in the range of −10 to 10×10 −7 /° C.
The content of SnO 2 in the LAS-type crystallized glass was measured at a position of 1 μm and a position of 0.5 mm from the glass surface not being in contact with the metal tin by point analysis using energy dispersive X-ray spectrometry (EDX). As analyzing devices, a scanning electron microscope (S-4300SE manufactured by Hitachi, Ltd.) was used for observing surface states, and an energy dispersive X-ray spectrometer (EMAX ENERGY EX-250 manufactured by HORIBA, Ltd.) was used for surface elemental analysis. As measurement conditions, the working distance was set to 15 mm, the accelerating voltage to 10 KV, the beam current value to 35 μA, and the measurement magnification to 5000 times.
Note that the content of SnO 2 (SnO 2 concentration gradient) in the LAS-type float glass before crystallization was identical to the measurement value after crystallization in each sample.
Further, the depth of devitrification from the glass surface not being in contact with the metal tin of the LAS-type crystallized glass was measured by using an optical microscope.
The transparency of the LAS-type crystallized glass was evaluated as described below. That is, glass which was sufficiently transparent without devitrification was represented by “⊚”, glass which was transparent by visual observation though devitrification was observed with an optical microscope (×500) was represented by “o”, and glass in which devitrification was observed remarkably by visual observation and which was opaque was represented by “x”.
Note that in the case where devitrification was observed in an LAS-type crystallized glass, devitrification was also observed in an LAS-type float glass before crystallization.
As evident from Tables 2 to 4, in any of the LAS-type crystallized glasses of Examples, the SnO 2 concentration gradient k was 2 mass %/mm or less and the content C 0 of SnO 2 was 0.8 mass % or less. Thus, the LAS-type crystallized glasses of Examples had less devitrification in the glass surfaces and were excellent in transparency. On the other hand, in each of the LAS-type crystallized glasses of Comparative Examples, the SnO 2 concentration gradient k or the content C 0 of SnO 2 was out of the range described above. Thus, the LAS-type crystallized glasses exhibited remarkable devitrification and were inferior in transparency.
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An LAS-type float glass, which is substantially free of As 2 O 3 and/or Sb 2 O 3 and precipitates a β-quartz solid solution or a β-spodumene solid solution as a main crystal by heat treatment, wherein, when C 1 [mass %] represents the content of SnO 2 at a glass surface, C 0 [mass %] represents the content of SnO 2 at a depth of 0.5 mm from the glass surface, and k [mass %/mm] represents an SnO 2 concentration gradient defined by k=(C 1 -C 0 )/0.5, the LAS-type crystallized glass satisfies relationships of K≦2 and C 0 ≦0.8 with respect to at least one surface thereof.
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[0001] This patent application claims the benefits of U.S. Provisional Application Ser. No. ______ (serial number not assigned yet), entitled “Methods and Kits for Topical Administration of Hyaluronic Acid,” by Dennis Gross filed on Feb. 21, 2006 under Attorney Docket No. 10853/7 and U.S. Provisional Application Ser. No. ______ (serial number not assigned yet), entitled “Methods and Kits for Topical Administration of Hyaluronic Acid,” by Dennis Gross filed on Feb. 28, 2006 under Attorney Docket No. 10853/8.
[0002] The present invention is related to improved methods and kits for administering hyaluronic acid to the skin of a subject involving self heat generation and massage.
BACKGROUND INFORMATION
[0003] Hyaluronic acid is a linear polysaccharide having repetitive alternate D-glucuronic acid and N-acetyl-D-glucosamine units, wherein each D-glucuronic acid unit is bonded to the immediately preceding N-acetyl-D-glucosamine unit via a β(1-4) linkage and each D-glucuronic acid unit is bonded to the following N-acetyl-D-glucosamine unit via a β(1-3) linkage. The disaccharide consisting of the D-glucuronic acid unit and the N-acetyl-D-glucosamine unit linked by the β(1-3) linkage is the basic building block of hyaluronic acid. Hyaluronic acid can be considered as a type of glycosaminoglycans or mucopolysaccharides. Hyaluronic acid molecules can consist of 250 to 25,000 pairs of D-glucuronic acid and N-acetyl-D-glucosamine units (Voet et al, Biochemistry, 1995, p. 264, John Wiley & Sons, Inc.). According to U.S. Pat. No. 6,838,086, hyaluronic acid molecules can consist of 2,000 to 10,000 pairs of D-glucuronic acid and N-acetyl-D-glucosamine units. The average molecular weight of hyaluronic acid can range from about 50,000 to about 8×10 6 Daltons depending on the source of the hyaluronic acid and its method of isolation (U.S. Pat. No. 4,303,676). Molecular weight of up to 13×10 6 has been reported for hyaluronic acid (U.S. Pat. Nos. 4,303,676 and 5,409,904). At physiological pH, the free carboxyl groups in the D-glucuronic acid units are ionized converting the acid form of hyaluronic acid to hyaluronate, which is anionic and can bind cations such as K + , Na + and Ca ++ .
[0004] Hyaluronic acid is a major component of the intercellular matrix and of the ground substance of connective tissues. Hyaluronic acid is also an integral component of complex proteoglycans. U.S. Pat. No. 6,946,551. Hyaluronic acid can be found in vitreous humor, synovial fluids, umbilical cord tissues, skin, rooster combs and certain Streptococcus species. Among animal tissues, soft connective tissues have the highest concentrations of hyaluronic acid. U.S. Pat. No. 4,141,973 discloses a process for obtaining ultra-pure, high molecular weight hyaluronic acid from animal tissues containing hyaluronic acid by removing blood from the animal tissues, extracting hyaluronic acid from the tissues, deproteinizing the extract and treating the extract with chloroform at pH 6.0-7.0 to remove any inflammation causing substances. U.S. Pat. No. 6,946,551 discloses a method of isolating hyaluronic acid from eggshell membrane. Commercially available hyaluronic acid is isolated from animal tissues such as mammalian umbilical cords and rooster combs, or obtained from the fermentation of certain hemolytic Streptococcal bacteria. Hyaluronic acid and alkali metal or ammonium salt thereof are generally available as a gel-like material (U.S. Pat. No. 5,409,904).
[0005] Hyaluronic acid can hold more water than other polymers and is probably responsible for the high water content of some tissues. U.S. Pat. No.6,946,551. The large molecular size and large numbers of hydroxy groups and anionic carboxyl groups probably account for the water holding property of hyaluronic acid. Hyaluronic acid is viscoelastic in that hyaluronic acid solutions are quite viscous at low shear rate and the solutions flow more freely as the shear rate increases (Voet et al, Biochemistry, 1995, p. 264). Hyaluronic acid is a good lubricant in the body (e.g., hyaluronic acid in synovial fluids providing lubrication for synovial membranes) and it can also provide elasticity to joints. Partly due to the large number of mutually repellant anionic carboxyl groups, hyaluronate tends to form a rigid and highly hydrated molecule (Voet et al, Biochemistry, 1995, p. 264). Hyaluronic acid can provide rigidity to vertebrate disks (U.S. Pat. No. 6,946,551).
[0006] Intra-articular injection of a preparation containing hyaluronic acid of a molecular weight exceeding 3×10 6 Daltons was disclosed to be useful in treating steroid arthropathy and progressive cartilage degeneration caused by proteoglycan degradation (U.S. Pat. No. 4,801,619). U.S. Pat. No. 6,607,745 discloses a method of relieving joint pain and musculoskeletal discomfort by oral ingestion of a composition comprising hyaluronic acid and an acceptable ingestible carrier. The method is useful for treating osteoarthritis and fibromyalgia. U.S. Pat. No. 5,409,904 discloses that hyaluronic acid compositions administered into the synovial space associate with a joint or tendon are useful in enhancing normal joint and tendon function by lubricating the joint and tendon against excess stress during movement.
[0007] U.S. Pat. No. 6,703,377 discloses a bone growth-promoting composition comprising hyaluronic acid and a growth factor such that the composition has a viscosity and biodegradability sufficient to persist at the site of desired bone growth for a duration enough to promote bone growth. The bone growth-promoting composition is injected through a syringe or catheter to the site of desired bone growth such as a bone fracture.
[0008] U.S. Pat. No. 6,509,322 discloses a pharmaceutical composition comprising hyaluronic acid, a pharmaceutically acceptable salt of hyaluronic acid, an ester of hyaluronic acid with an alcohol, intermolecular ester of hyaluronic acid or intramolecular ester of hyaluronic acid. The composition is useful for accelerating tissue repair in the treatment of bums, sores, ulcerations and wounds. The composition can be in the form of an aerosol, liquid spray, foam or dry spray. The composition is applied topically by spraying.
[0009] Hyaluronic acid has been reported to be useful in surgery. U.S. Pat. No. 5,140,016 discloses that using a solution comprising a hydrophilic, high molecular weight polymer such as hyaluronic acid having a molecular weight of at least about 500,000 Daltons to coat tissue surfaces and surgical instruments involved in surgery can prevent adhesions during surgery. According to U.S. Pat. No. 5,190,759, a solution containing hyaluronic acid having a molecular weight of 500,000 to 6×10 6 Daltons is useful in preventing tissue adhesions following surgical procedures. Hyaluronic acid compositions introduced into a surgical site either during or after surgery are useful in preventing post-operative adhesion of healing tissues (U.S. Pat. No. 5,409,904). In a method of shortening the length of time required to complete a surgical procedure, an hyaluronic acid solution is used to coat tissue exposed at a surgical site (U.S. Pat. No. 6,541,460).
[0010] There are reports that hyaluronic acid is useful for the skin. U.S. Pat. No. 4,303,676 discloses a water-based, highly viscoelactic composition comprising water, a mixture of a low molecular weight hyaluronate (10,000 to 200,000 Daltons) and a high molecular weight hyaluronate (1×10 6 to 4.5×10 6 Daltons) in a ratio of 0.3 to 2.1 and protein derived from the natural material from which the hyaluronate is obtained. The composition is useful as a base for cosmetic formulations and also has emollient, moisturizing, elasticizing and lubricating properties when applied to the skin (U.S. Pat. No. 4,303,676).
[0011] U.S. Pat. No. 5,571,503 discloses a cosmetic composition for protecting the skin from several damaging components of environmental pollution, providing protection against moisture loss, and protecting the skin against damage due to free radical activity and UV light. The cosmetic composition comprises a sunscreen, an anti-pollution complex, a micellar complex containing sodium hyaluronate and an anti-free radical complex containing melanin, vitamin E or vitamin C.
[0012] According to U.S. Pat. No. 5,728,391, hyaluronic acid having a low molecular weight fails to provide adequate moisturizing effect in skin care compositions. Hyaluronic acid having a molecular weight of at least 4×10 6 tends to be highly viscous, making formulation difficult. U.S. Pat. No. 5,728,391 discloses an agent containing hyaluronic acid having an average molecular weight of 800,000 to 4×10 6 , useful for treating a skin disease selected from contact dermatitis, xerosis senilis, asteatosis, eczema, miliaria and diaper rash.
[0013] U.S. Pat. No. 6,806,259 discloses a soft gelatin formulation comprising low molecular weight hyaluronic acid, preferably having molecular weight between 50,000 to 200,000 Daltons. The formulation is administered orally for use as a nutritional supplement to provide the primary benefit of causing skin softening.
[0014] U.S. Pat. No. 6,689,349 discloses a composition comprising fragments of hyaluronic acid produced by means of enzymes from hyaluronic acid, pharmaceutical carriers and auxiliary substances. The composition is useful in protecting the skin and preventing traumatic symptoms, inflammation and aging due to environmental factors or illnesses. The composition is formulated in the form of a paste, ointment, cream, emulsion, gel, stick, colloidal carrier system or solution.
[0015] U.S. Pat. No. 6,890,901 discloses a pharmaceutical composition comprising a mixture of hyaluronic acid and liposomes encapsulating a pharmaceutically active substance effective to treat skin disorder, wherein the pharmaceutical composition is administered topically to deliver the pharmaceutically active substance in the dermis or sub-dermis while minimizing systemic circulation of the substance.
[0016] Even though the beneficial effects of hyaluronic acid to the skin have been known for some time and a number of dermatological products containing hyaluronic acid are commercially available, there is still a need for an improved method and kit for administering hyaluronic acid to the skin which is both highly effective and relatively easy to use. The present invention meets such a need with a novel method of administering a composition containing hyaluronic acid to the skin, and a kit suitable for use in the novel method.
SUMMARY OF THE INVENTION
[0017] The present invention provides a method for administering hyaluronic acid and/or hyaluronate to the skin of a subject or for treating the skin of a subject comprising (a) applying an HA liquid to an area of the skin, wherein the HA liquid comprises HA, and wherein HA is at least one substance selected from the group consisting of hyaluronic acid, hyaluronate, cosmetically acceptable salts of hyaluronic acid, intramolecular esters of hyaluronic acid and intermolecular esters of hyaluronic acid;
[0018] (b) applying a self-heating mask composition into the area of the skin to generate heat locally, wherein the self-heating mask composition comprises at least one silicoaluminate, preferably sodium silicoaluminate, and wherein the self-heating mask composition is preferably massaged into the area of the skin to promote heat generation;
[0019] (c) letting the self-heating mask composition set on the area of the skin to form a mask;
[0020] (d) optionally massaging the mask into the area of the skin;
[0021] (e) optionally removing the mask from the area of the skin; and thereafter
[0022] (f) optionally applying another skin care product to the area of the skin.
[0023] The present invention also provides a kit useful for skin treatment or for administering hyaluronic acid and/or hyaluronate, wherein the kit comprises an HA liquid and a self-heating mask composition, and wherein the HA liquid comprises HA and the self-heating mask composition comprises sodium silicoaluminate. Preferably, the kit further comprises at least one device, e.g., brush or pad, for applying the HA liquid and/or the self-heating mask composition to the skin.
[0024] The method and kit of the present invention are useful in allowing consumers to achieve professional skin care results at home in a small number of easy steps. The HA liquid, which may contain a cocktail of antioxidants, can plump trouble areas minimizing fine lines and wrinkles caused by dehydration. The self-heating mask composition can create a barrier on the skin increasing circulation and forcing optional antioxidant and collagen stimulating ingredients deep into the skin to achieve more beneficial effects from the antioxidant and collagen simulating ingredients. Skin treatment using the method and/or kit of the invention can leave dry, dehydrated skin immediately plumper, smoother and younger-looking.
[0025] The optional skin care product applied in step (f) can be, but is not limited to, a moisturizer, a skin peel product such as an acid/alkaline skin peel product disclosed in U.S. patent application Ser. No. 09/338,729 filed on Jun. 23, 1999, the disclosure of which is herein incorporated by reference, Antioxidant Firming Face Serum and/or Anti-Aging Vitamin C Gel. Alternatively, the moisturizer, skin peel product, Antioxidant Firming Face Serum and/or Anti-Aging Vitamin C Gel can be applied to the skin before the application of the method or kit of the present invention.
[0026] Before and/or after the application of the method or kit of the present invention to the skin, the skin can optionally be subjected to one or more skin care treatments, e.g., facial, acne treatment, acne prevention, and skin peel, performed by a professional or consumer. For instance, the one or more skin care treatments can be performed to the skin within 12 hours, preferably within 6 hours, more preferably within 3 hours, further more preferably within 1 hour, even more preferably within 30 minutes, and most preferably within 15 minutes, before and/or after the application of the method or kit of the present invention to the skin.
DETAILED DESCRIPTION OF THE INVENTION
[0027] In the description of the present invention, the term “HA” means, unless otherwise indicated, at least one substance selected from the group consisting of hyaluronic acid, hyaluronate, cosmetically acceptable salts of hyaluronic acid, intramolecular esters of hyaluronic acid and intermolecular esters of hyaluronic acid.
[0028] The term “intramolecular esters of hyaluronic acid” refers to esters formed by the reaction of at least one carboxyl group in a molecule of hyaluronic acid or hyaluronate with at least one hydroxy group in the same molecule of hyaluronic acid or hyaluronate.
[0029] The term “intermolecular esters of hyaluronic acid” refers to esters formed by the reaction of at least one carboxyl group in a molecule of hyaluronic acid or hyaluronate with at least one hydroxy group in another molecule of hyaluronic acid or hyaluronate.
[0030] The term “subject” means a mammal, preferably a human. The subject can be a human consumer or patient. More preferably, the subject is a human consumer.
[0031] As used herein, the term “cosmetically acceptable” modifying a substance means that the substance is of sufficiently high purity and suitable for use in contact with human skin without undue toxicity, incompatibility and instability. A “cosmetically acceptable” substance, preferably, causes little or no allergic response.
[0032] The term “cosmetically acceptable salts of hyaluronic acid” includes sodium, potassium, lithium, calcium, magnesium, aluminum, zinc and ammonium salts of hyaluronic acid. Preferably, the term “cosmetically acceptable salts of hyaluronic acid” means sodium salt of hyaluronic acid.
[0033] The HA liquid comprises HA. Preferably, the HA liquid further comprises at least one cosmetically acceptable vehicle or carrier. The HA liquid may also include at least one emollient/humectant/moisturizer and/or at least one cosmetically acceptable excipient. The HA liquid may also include at least one additional active ingredient. The HA liquid may also include at least one aesthetic component.
[0034] The self-heating mask composition comprises at least one silicoaluminate. Examples of “silicoaluminate” include sodium silicoaluminate, potassium silicoaluminate, calcium silicoaluminate, magnesium silicoaluminate and zinc silicoaluminate.
[0035] The self-heating mask composition, preferably, further comprises at least one emollient/humectant/moisturizer (e.g., butylene glycol). The self-heating mask composition may further comprise at least one additional active ingredient, at least one aesthetic component, at least one cosmetically acceptable excipient and/or at least one cosmetically acceptable vehicle or carrier.
[0036] The methods or kits of the present invention are also useful in potentiating or enhancing the effects of the at least one emollient/humectant/moisturizer, at least one cosmetically acceptable excipient and/or at least one additional active ingredient present in the HA composition and/or the self-heating mask composition.
[0037] The at least one cosmetically acceptable vehicle or carrier is, preferably, water or a cosmetically acceptable aqueous buffer having a pH of about 7.0 to about 7.4, and, more preferably, the water or aqueous buffer is purified and/or sterile.
[0038] The at least one cosmetically acceptable excipient is selected from the group consisting of surfactant/emulsifying agents, absorbents, antifoaming agents, binders, biological additives, chelating agents, denaturants, preservatives, solubilizing agents, solvents and thickening agents.
[0039] The at least one additional active ingredient is selected from the group consisting of antioxidants, free-radical scavengers, antimicrobial agents, topical analgesics, steroidal anti-inflammatory drugs, anti-acne agents, reducing agents, vitamins, skin protecting agents, skin bleaching agents, skin conditioning agents, skin soothing agents, skin healing agents, green tea extract, P. emblica (Amla), arnica, chamomile extract and cucumber extract. The at least one additional active ingredient is, preferably, at least one antioxidant.
[0040] Suitable surfactant/emulsifying agents include ceteareths, ceteths, laneths, laureths, isoseareths, steareths, cetyl alcohol, deceths, dodoxynols, glyceryl palmitate, glyceryl stearate, laneths, myreths, nonoxynols, octoxynols, oleths, PEG-castor oil, poloxamers (e.g., poloxamer 407), poloxamines, polysorbates, sodium laurate, ammonium laureth sulfate, sodium laureth sulfate, sodium lauroyl sarcosinate, sodium lauroyl taurate, sodium lauryl sulfate, sodium methyl cocoyl taurate, sodium methyl oleoyl taurate, sodium nonoxynol sulfate, sodium cetyl sulfate, sodium cetearyl sulfate, sodium cocoate, sodium cocoyl isethionate and sodium cocoyl sarcosinate. Other suitable surfactant/emulsifying agents would be known to one of skill in the art and are listed in the CTFA International Cosmetic Ingredient Dictionary and Handbook, Vol. 2, 7th Edition (1997). Preferred surfactants include octoxynol-9 and polysorbate-20.
[0041] Examples of chelating agents are disodium EDTA, trisodium EDTA, tetrasodium EDTA and sodium metasilicate.
[0042] Examples of suitable preservatives include imidazolidinyl urea, diazolidinyl urea, phenoxyethanol, methylparaben, ethylparaben and propylparaben.
[0043] Examples of thickening agents include isopropyl myristate, isopropyl palmitate, isodecyl neopentanoate, squalene, mineral oil, C 12 -C 15 benzoate and hydrogenated polyisobutene.
[0044] Examples of antioxidants and free-radical scavengers include ascorbic acid, salts of ascorbic acid such as ascorbyl palmitate and sodium ascorbate, ascorbyl glucosamine, vitamin E (i.e., tocopherols such as α-tocopherol), derivatives of vitamin E (e.g., tocopheryl acetate), retinoids such as retinoic acid, retinol, trans-retinol, cis-retinol, mixtures of trans-retinol and cis-retinol, 3-dehydroretinol and derivatives of vitamin A (e.g., retinyl acetate, retinal and retinyl palmitate, also known as tetinyl palmitate), sodium citrate, sodium sulfite, lycopene, anthocyanids, bioflavinoids (e.g., hesperitin, naringen, rutin and quercetin), superoxide dismutase, glutathione peroxidase, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), indole-3-carbinol, pycnogenol, melatonin, sulforaphane, pregnenolone, lipoic acid and 4-hydroxy-5-methyl-3[2H]-furanone.
[0045] The antimicrobial agents are antibacterial agents and antifungal agents. Examples of the antimicrobial agents include benzoyl peroxide, erythromycin, tetracycline, triclosan, azelaic acid, clindamycin, chlorhexidine, neomycin, miconazole and clotrimazole.
[0046] Examples of topical analgesics include aspirin and non-steroidal anti-inflammatory drugs. Suitable non-steroidal anti-inflammatory drugs include ibuprofen, naproxen, benoxaprofen, flurbioprofen, fenoprofen, fenbufen, ketoprofen, indoprofen, pirprofen, carprofen, oxaprozin, pranoprofen, microprofen, tioxaprofen, suprofen, alminoprofen, tiaprofenic acid, fluprofen and bucloxic acid.
[0047] The skin conditioning agents can be emollients, humectants and moisturizers, which include urea; guanidine; aloe vera; glycolic acid and glycolate salts such as ammonium and quaternary alkyl ammonium; lactic acid and lactate salts such as sodium lactate, ammonium lactate and quaternary alkyl ammonium lactate; polyhydroxy alcohols such as sorbitol, glycerol, hexanetriol, propylene glycol, butylene glycol, hexylene glycol, polyethylene glycol; carbohydrates such as alkoxylated glucose; starches; starch derivatives; glycerin; pyrrolidone carboxylic acid (PCA); lactamide monoethanolamine; acetamide monoethanolamine; volatile silicone oils; nonvolatile silicone oils; and mixtures thereof. Suitable silicone oils can be polydialkylsiloxanes, polydiarylsiloxanes, polyalkarylsiloxanes and cyclomethicones having 3 to 9 silicon atoms.
[0048] Skin soothing agents include bisabolol.
[0049] Suitable steroidal anti-inflammatory drugs include, for example, hydrocortisone and bensonide.
[0050] Suitable anti-acne agents can be drying agents, keratolyic agents, epidermolytic agents, antimicrobial agents and retinoids. Examples of anti-acne agents include sulfur, resorcinol, glycolic acid, lactic acid, pyruvic acid, salicylic acid, retinoic acid, derivatives of retinoic acid, and tetracycline.
[0051] The skin protecting agents are agents that protect the skin against chemical irritants and/or physical irritants, e.g., UV light, including sunscreens, anti-acne additives, anti-wrinkle and anti-skin atrophy agents. Suitable sunscreens as skin protecting agents include 2-ethylhexyl p-methoxycinnamate, 2-ethylhexyl N,N-dimethyl-p-aminobenzoate, p-aminobenzoic acid, 2-phenylbenzimidazole-5-sulfonic acid, octocrylene, oxybenzone, homomenthyl salicylate, octyl salicylate, 4,4′-methoxy-t-butyldibenzoylmethane, 4-isopropy dibenzoylmethane, 3-benzylidene camphor, 3-(4-methylbenzylidene) camphor, anthanilates, ultrafine titanium dioxide, zinc oxide, iron oxide, silica, 4-N,N-(2-ethylhexyl)methylaminobenzoic acid ester of 2,4-dihydroxybenzophenone, 4-N,N-(2-ethylhexyl)-methylaminobenzoic acid ester with 4-hydroxydibenzoylmethane, 4-N,N-(2-ethylhexyl)-methylaminobenzoic acid ester of 2-hydroxy-4-(2-hydroxyethoxy)benzophenone and 4-N,N(2-ethylhexyl)-methylaminobenzoic acid ester of 4-(2-hydroxyethoxy)dibenzoylmethane. Suitable anti-acne agents include salicylic acid; 5-octanoyl salicylic acid; resorcinol; retinoids such as retinoic acid and its derivatives; sulfur-containing D and L amino acids other than cysteine; lipoic acid; antibiotics and antimicrobials such as benzoyl peroxide, octopirox, tetracycline, 2,4,4′-trichloro-2′-hydroxydiphenyl ether, 3,4,4′-trichlorobanilide, azelaic acid, phenoxyethanol, phenoxypropanol, phenoxisopropanol, ethyl acetate, clindamycin and melclocycline; flavonoids; and bile salts such as scymnol sulfate, deoxycholate and cholate. Examples of anti-wrinkle and anti-skin atrophy agents are retinoic acid and its derivatives, retinol, retinyl esters, salicylic acid and its derivatives, sulfur-containing D and L amino acids except cysteine, alpha-hydroxy acids (e.g., glycolic acid and lactic acid), phytic acid, lipoic acid and lysophosphatidic acid.
[0052] Suitable skin bleaching agents include, for example, hydroquinone, kojic acid and sodium metabisulfite.
[0053] The at least one aesthetic agent can be at least one of fragrances, pigments, colorants, essential oils, skin sensates and astringents. Suitable aesthetic agents include clove oil, menthol, camphor, eucalyptus oil, eugenol, methyl lactate, bisabolol, witch hazel distillate (preferred) and green tea extract (preferred).
[0054] In some of the embodiments of the present invention, the HA liquid comprises HA, at least one anti-oxidant, at least one skin conditioning agent, at least one reducing agent, at least one additional active agent, at least one cosmetically acceptable vehicle or carrier and at least one cosmetically acceptable excipient. The HA can be hyaluronic acid and/or hyaluronate, preferably sodium hyaluronate. The at least one anti-oxidant can be ascorbic acid, ascorbyl palmitate, ascorbyl glucosamine, tocopheryl acetate, retinyl palmitate, superoxide dismutase, or mixtures thereof. The at least one skin conditioning agent can be cyclomethicone and/or dimethiconol. The at least one reducing agent can be ubiquinone. The at least one additional active agent can be Camellia sinensis leaf extract and/or white tea extract or juice, preferably Camellia sinensis leaf extract. The at least one cosmetically acceptable vehicle or carrier can be purified or sterile water, preferably purified water. The at least one cosmetically acceptable excipient can be phospholipids.
[0055] In one of the embodiments of the present invention, the HA liquid comprises cyclomethicone, dimethiconol, sodium hyaluronate, Camellia sinensis leaf extract, ascorbyl palmitate, ascorbyl glucosamine, tocopheryl acetate, retinyl palmitate, superoxide dismutase, ubiquinone, phospholipids and purified water with the optional inclusion of ascorbic acid.
[0056] In one of the embodiments of the present invention, the HA liquid comprises the following ingredients:
Ingredient Amount (Weight %) cyclomethicone about 0% to about 99%, dimethiconol about 0% to about 30%, sodium hyaluronate about 0.005% to about 99.5%, Camellia sinensis leaf extract about 0% to about 20%, optional ascorbic acid about 0% to about 20%, ascorbyl palmitate about 0% to about 20%, ascorbyl glucosamine about 0% to about 20%, tocopheryl acetate about 0% to about 20%, retinyl palmitate about 0% to about 20%, superoxide dismutase about 0% to about 1%, ubiquinone about 0% to about 20%, phospholipids about 0% to about 20% and purified water about 0% to about 50%.
[0057] In the embodiment, the HA liquid preferably comprises the following ingredients:
Ingredient Amount (Weight %) cyclomethicone about 5% to about 95%, dimethiconol about 5% to about 25%, sodium hyaluronate about 0.01% to about 85%, Camellia sinensis leaf extract about 0.01% to about 10%, optional ascorbic acid about 0.01% to about 10% (if present), ascorbyl palmitate about 0.01% to about 10%, ascorbyl glucosamine about 0.01% to about 10%, tocopheryl acetate about 0.01% to about 10%, retinyl palmitate about 0.01% to about 10%, superoxide dismutase about 0.0001% to about 0.1%, ubiquinone about 0.01% to about 10%, phospholipids about 0.01% to about 10% and purified water about 0.01% to about 20%.
[0058] In the embodiment, the HA liquid more preferably comprises the following ingredients:
Ingredient Amount (Weight %) cyclomethicone about 10% to about 90%, dimethiconol about 10% to about 20%, sodium hyaluronate about 0.01% to about 70%, Camellia sinensis leaf extract about 0.01% to about 5%, optional ascorbic acid about 0.01% to about 5% (if present), ascorbyl palmitate about 0.01% to about 5%, ascorbyl glucosamine about 0.01% to about 5%, tocopheryl acetate about 0.01% to about 5%, retinyl palmitate about 0.01% to about 5%, superoxide dismutase about 0.0001% to about 0.01%, ubiquinone about 0.01% to about 5%, phospholipids about 0.01% to about 5% and purified water about 0.01% to about 10%.
[0059] In the embodiment, the HA liquid even more preferably comprises the following ingredients:
Ingredient Amount (Weight %) cyclomethicone about 86.90%, dimethiconol about 13.00%, sodium hyaluronate about 0.01%, Camellia sinensis leaf extract about 0.01%, optional ascorbic acid about 0.01% (if present), ascorbyl palmitate about 0.01%, ascorbyl glucosamine about 0.01%, tocopheryl acetate about 0.01%, retinyl palmitate about 0.01%, superoxide dismutase about 0.0001%, ubiquinone about 0.02%, phospholipids about 0.01% and purified water about 0.01%.
[0060] In some of the embodiments of the present invention, the self-heating mask composition comprises at least one silicoaluminate, preferably sodium silicoaluminate, at least one skin conditioning agent, at least one surfactant, at least one additional active agent, at least one anti-oxidant, at least one cosmetically acceptable excipient and at least one aesthetic agent, and optionally at least one cosmetically acceptable vehicle or carrier. The at least one skin conditioning agent can be butylene glycol and/or petrolatum. The at least one surfactant can be PEG-8 and/or methyl GLUCETH-20. The at least one additional active agent can be Camellia sinensis leaf extract and/or white tea extract or juice. The at least one anti-oxidant can be ascorbyl palmitate, retinyl palmitate, tocopheryl acetate, or mixtures thereof. The at least one cosmetically acceptable excipient can be hydroxypropylcellulose and/or hydroxypropyl methylcellulose.
[0061] In one of the embodiments of the present invention, the self-heating mask composition comprises sodium silicoaluminate, butylene glycol, PEG-8, Camellia sinensis leaf extract, white tea extract or juice, ascorbyl palmitate, retinyl palmitate, tocopheryl acetate, dimethicone, methyl GLUCETH-20, hydroxypropylcellulose, hydroxypropyl methylcellulose, petrolatum and titanium dioxide, with optional inclusion of phospholipids.
[0062] In one of the embodiments of the present invention, the self-heating mask composition comprises the following ingredients:
Ingredient Amount (weight %) sodium silicoaluminate about 2% to about 99%, butylene glycol about 0% to about 98%, PEG-8 about 0% to about 25%, Camellia sinensis leaf extract about 0% to about 20%, white tea extract or juice about 0% to about 20%, ascorbyl palmitate about 0% to about 20%, retinyl palmitate about 0% to about 20%, tocopheryl acetate about 0% to about 20%, dimethicone about 0% to about 20%, methyl GLUCETH-20 about 0% to about 20%, hydroxypropylcellulose about 0% to about 20%, hydroxypropyl methylcellulose about 0% to about 20%, petrolatum about 0% to about 20%, titanium dioxide about 0% to about 20% and optional phospholipids about 0% to about 20%.
[0063] In the embodiment, the self-heating mask composition preferably comprises the following ingredients:
Ingredient Preferred Amount (Weight %) sodium silicoaluminate about 10% to about 80%, butylene glycol about 10% to about 80%, PEG-8 about 0.1% to about 10%, Camellia sinensis leaf extract about 0.01% to about 10%, white tea extract or juice about 0.01% to about 10%, ascorbyl palmitate about 0.01% to about 10%, retinyl palmitate about 0.01% to about 10%, tocopheryl acetate about 0.01% to about 10%, dimethicone about 0.01% to about 10%, methyl GLUCETH-20 about 0.01% to about 10%, hydroxypropylcellulose about 0.01% to about 10%, hydroxypropyl methylcellulose about 0.01% to about 10%, petrolatum about 0.1% to about 10%, titanium dioxide about 0.01% to about 10% and optional phospholipids about 0.01% to about 10% (if present).
[0064] In the embodiment, the self-heating mask composition more preferably comprises the following ingredients:
Ingredient More Preferred Amount (Weight %) sodium silicoaluminate about 20% to about 70%, butylene glycol about 20% to about 70%, PEG-8 about 0.5% to about 5%, Camellia sinensis leaf extract about 0.01% to about 2%, white tea extract or juice about 0.01% to about 2%, ascorbyl palmitate about 0.01% to about 2%, retinyl palmitate about 0.01% to about 2%, tocopheryl acetate about 0.01% to about 2%, dimethicone about 0.01% to about 2%, methyl GLUCETH-20 about 0.01% to about 2%, hydroxypropylcellulose about 0.01% to about 2%, hydroxypropyl methylcellulose about 0.01% to about 2%, petrolatum about 0.5% to about 5%, titanium dioxide about 0.01% to about 2% and optional phospholipids about 0.01% to about 2% (if present).
[0065] In the embodiment, the self-heating mask composition even more preferably comprises the following ingredients:
Ingredient Amount (Weight %) sodium silicoaluminate about 31.84%, butylene glycol about 62.02%, PEG-8 about 3.35%, Camellia sinensis leaf extract about 0.10%, white tea extract or juice about 0.01%, ascorbyl palmitate about 0.01%, retinyl palmitate about 0.01%, tocopheryl acetate about 0.01%, dimethicone about 0.42%, methyl GLUCETH-20 about 42%, hydroxypropylcellulose about 0.30%, hydroxypropyl methylcellulose about 0.30%, petrolatum about 1%, titanium dioxide about 0.20% and optional phospholipids about 0.01% (if present).
[0066] In some of the embodiments of the method of the present invention, the massaging in step (b) is preferably performed with damp fingers to promote heat generation. Preferably, the massaging in step (b) is performed for about 20 seconds to about 3 minutes, more preferably about 0.5 minute to about 2 minutes, and even more preferably about 1 minute, to activate heat.
[0067] In some of the embodiments of the method of the present invention, the self-heating mask composition is set on the area of the skin in step (c) for preferably about 3 minutes to about 30 minutes, more preferably about 5 minutes to about 20 minutes, and even more preferably about 10 minutes to about 15 minutes. Without being bound by any theory, it is believed that the setting of the self-heating mask would provide heat and moisture to the area of the skin.
[0068] In some of embodiments of the method of the present invention, the optional massaging in step (d) is performed for about 20 seconds to about 3 minutes, preferably about 0.5 minute to about 2 minutes, and more preferably about 1 minute.
[0069] In some of embodiments of the method of the present invention, the mask is removed from the area of the skin in step (e) preferably with a warm towel, wherein the warm towel may optionally be wet.
[0070] In some of embodiments of the method of the present invention, the optional additional skin care product applied in step (f) can be a skin peeling product, e.g., the skin peeling product disclosed in U.S. patent application Ser. No. 09/338,729, filed Jun. 23, 1999, the disclosure of which is incorporated by reference herein.
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The present invention provides a method for treating the skin of a subject comprising (a) applying an HA liquid to an area of the skin, wherein the HA liquid comprises hyaluronic acid, hyaluronate, cosmetically acceptable salts of hyaluronic acid, intramolecular esters of hyaluronic acid and/or intermolecular esters of hyaluronic acid; (b) massaging a self-heating mask composition into the area of the skin for a duration sufficient to activate heat, wherein the self-heating mask composition comprises at least one silicoaluminate; (c) letting the self-heating mask composition set on the area of the skin to form a mask; (d) optionally massaging the mask into the area of the skin; (e) optionally removing the mask from the area of the skin; and thereafter (f) optionally applying another skin care product to the area of the skin. The present invention also provides a kit useful for skin treatment, wherein the kit comprises the HA liquid and the self-heating mask composition comprises at least one silicoaluminate.
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The present invention relates to a simplified process and apparatus for the purification of exhaust gases containing oxides of nitrogen and sulfur from combustion installations.
Oxides of nitrogen as well as sulfur oxides which are formed as a result of combustion processes are counted among the main causes of the "acid rain" problem and the photosmog problem and of the resulting damage to the environment. These harmful substances should therefore be largely eliminated by removal from the exhaust gases from combustion prior to their discharge into the atmosphere.
Sources of the nitrogen oxide or sulfur oxide emissions are motor vehicle traffic, stationary combustion motors, power plants, heating power plants, steam generators for industrial purposes and for industrial production installations. In addition, carbon monoxide and hydrocarbons are also emitted by these sources.
As a result of the use of fuels having a low content of nitrogen and sulfur as well as by suitable additions to the fuel or by modification of the combustion systems, it is possible to achieve a lowering of the concentration of harmful substances in the exhaust gas; however, there are technical as well as economic limits to these primary procedures so that it has not been possible hitherto to achieve an exhaust gas sufficiently free of nitric oxide and/or sulfur oxide.
Exhaust gases from, for example, combustion operations using fossil fuels or from operations using an excess of the stoichiometric amount, i.e., combustion power plants operating on the lean side, contain excess oxygen in addition to oxides of nitrogen and sulfur.
The denitrification and desulfurization of these exhaust gases has been accomplished hitherto as a rule in separate processing steps which are installed at various points in the path of the exhaust flue gas. Known processes for the combined denitrification and desulfurization have been hitherto known to be very expensive and are imbued with many disadvantages. In the case of the large scale commercial development therefore, at the present time the preferred mode of operation is with separate denitrification and desulfurization operations.
The nitric oxide diminution in the case of combustion takes place as a rule through catalytic reduction. In order to ensure an optimal utilization of the needed reduction agent, primarily selective catalytic reduction processes are considered for the removal of nitric oxides because of the oxygen content in the exhaust gas. As a reduction agent, ammonia gas has proven itself to be suitable because it reacts easily with oxides of nitrogen in the presence of an appropriate suitable catalyst for the reaction, but only to a slight extent with the oxygen present in the gas.
In contrast to the denitrification process, noncatalytically wet processes have prevailed to the greatest extent for the desulfurization of exhaust gases. In the instance of the process used most frequently, the sulfur is separated in the form of gypsum. First of all the sulfur dioxide present in the exhaust is oxidized into sulfur trioxide with oxygen of the air, optionally after previous wet absorption. At the same time or subsequently, one treats this with a calcium hydroxide-, calcium carbonate- or calcium oxide suspension. The gypsum obtained thereby must then be deposited either on a waste dump or after reprocessing according to known methods, it may be used in the building material industry.
In the case of combustion power plants the following approaches are being used at the present time for the purification of exhaust gas;
1. Catalytic denitrification in the "hot" part of the exhaust flue gas in the high dust zone and desulfurization after the removal of dust from the exhaust flue gas by conversion of the sulfur dioxide into gypsum.
For this purpose an ammonia/air-mixture is distributed homogeneously in the flow of exhaust flue gas immediately downstream from the boiler. The reaction mixture hereupon passes in contact with a denitrification catalyst which is maintained at about 370°-400° C. In a subsequent heat exchanger, heat is removed from the flue gas which serves for example for the preheating of the combustion air for the boiler. The dust is then removed from the exhaust flue gas. The exhaust flue gas being largely free of dust but still containing sulfur dioxide is then reacted in the exhaust flue gas desulfurization apparatus with oxygen from the air and with a calcium compound for conversion into gypsum. The exhaust gas purified in such a way is discharged into the atmosphere through a chimney.
2. Desulfurization as set forth in "1" above followed by catalytic denitrification in the "cold" part of the flue gas in the low dust zone.
For this purpose, heat is removed from the flue gas in a heat exchanger after leaving the boiler and the flue dust is separated. There then follows the desulfurization of the flue gas. This is accomplished according to the same processing principle as set forth in "1" above. By means of an additional heat exchanger, the flue gas is preheated with the flue gas leaving the denitrification process and is then brought to the reaction temperature needed for the denitrification in a subsequent heating arrangement which burns, for example, natural gas in the stream of flue gas. The flue gas heated in such a way is now mixed with the reduction agent ammonia and then passes in contact with the denitrification catalyst. The nitric oxides are reduced selectively to nitrogen and steam. The denitrified flue gas is then carried back to the heat exchanger in which the flue gases coming from the desulfurization installation are preheated; they then pass through this heat exchanger and thereafter move into the chimney.
Both of these known flue gas purification measures discussed above, however, have a number of disadvantages which adversely affect the operation of the combustion installations.
The catalytic removal of nitrogen oxides according to "1" above has the advantage that in the case of a full load operation, a flue gas temperature of 350°-400° C. may be reached. These are temperatures at which denitrification catalysts can be utilized. In the case of a variable load operation which is very frequently the rule in the case of German power plants, the flue gas temperature drops as a rule below the minimum required for the operation of the catalyst in the partial load area, so that an expensive bypass connection system is necessary for the branching off of flue gas before the last step of heat removal in the boiler in order to maintain the reaction temperature.
Operations that are carried out in the zone of high dust leads, moreover, to catalyst abrasion by the flue dust and may cause deposits and thus plugging up of the catalyst channels or pores. The consequence of this is that for the sake of prevention a cleaning by blowing off, for example, with hot steam is required at relatively short time intervals.
In the case of each denitrification installation operated with ammonia moreover, the problem occurs, that this reduction agent is not completely converted and a small quantity of it, designated as "ammonia leakage", is present in the flue gas after it passes through the denitrification installation. This, in consequence of conversion between ammonia and the sulfur oxides present in the flue gas, leads to corrosive and sticky deposits of ammonium hydrogen sulfate and/or ammonium sulfate, for example, on the heat exchanging surfaces of the air preheater. The scrubbing of the air preheater which therefore becomes necessary periodically creates, in turn, a waste water problem. Furthermore, the dust from the dust removal apparatus as well as the gypsum from the flue gas desulfurization apparatus is contaminated with ammonia and renders further utilization or waste management more dificult. Ammonia escaping from the chimney leads to further adverse environmental impact.
According to approach "2" above, the flue gas in contact with the denitrification catalyst contains only small quantities of dust and sulfur dioxide which in itself is favorable for the functioning of the denitrification catalyst. This advantage however is offset by a series of disadvantages. Thus, for example, downstream from the desulfurization installation, a gas preheater and a support burner must be installed which is fired as a rule with high grade fuel for example natural gas, an expensive primary energy source. From that standpoint, additional investment and operating costs arise. The problem of the corrosive ammonium salt deposits and of the waste wash waters also exists in accordance with this procedure. However, the gypsum is no longer contaminated with ammonia.
Both known processing concepts have in common the step that the flue gas desulfuriation is carried out in a wet process, whereby gypsum is produced. As an operation substance, one uses for this purpose in most cases limestone which creates additional costs. The gypsum obtained by the method is of limited usefulness and can be sold only partially in the construction industry because of cost and because of an insufficient purity.
Accordingly, it is an object of the invention to provide a process for the purification of exhaust gases containing oxides of nitrogen and sulfur obtained from combustion installations and industrial processes, by the selective catalytic reduction of the oxides of nitrogen with ammonia, the subsequent oxidation of sulfur dioxide with oxygen and conversion of the sulfur trioxide obtained thereby into a compound containing sulfate ions which avoids the disadvantages of the known processes.
A feature of the present invention resides in the fact that the sulfur dioxide oxidation is carried out utilizing a catalyst for the reaction to produce sulfur trioxide, which is then converted after intermediate cooling into sulfuric acid using water. According to a very advantageous aspect of the process of the invention, the reduction and oxidation operations are carried out in one single reactor or reaction zone which has a first section equipped with the reduction catalyst for the reaction and a second section equipped with the oxidation catalyst for the reaction. Therefore, the denitrification and desulfurization take place as a result of the fact that the exhaust gases are brought into contact in a reactor immediately one after the other with two different reaction specific catalysts. The exhaust gas containing the harmful substances is mixed for this purpose with the gaseous reduction agent ammonia and is passed into contact with the first catalyst at an elevated temperature whereby the selective reduction of the nitrogen oxides takes place.
It is possible to use for this purpose base metal-containing as well as precious metal-containing catalysts. In this process, consideration must be taken of the fact that no substances are to be carried out of the first catalyst stage which might cause a contamination at the oxidation catalyst located downstream. Directly after the emergence from the reduction catalyst, the exhaust gas still containing sulfur dioxide, oxygen, as well as possibly carbon monoxide and/or hydrocarbons, is passed into contact with the oxidation catalyst whereby the sulfur dioxide is converted into sulfur trioxide in high yields. Any carbon monoxide and/or hydrocarbons present in the gas stream are converted simultaneously into carbon dioxide. After cooling of the flue gases, sulfur trioxide is contacted with aqueous sulfuric acid for example, in a gas scrubber unit and is separated as sulfuric acid with as high a concentration as possible. For this purpose, known installations and apparatus are suitable which are used, for example, in the case of sulfuric acid production.
The reduction step can be carried out using an exhaust gas which has little dust content or from which the dust has been largely removed; or a removal of the dust can be accomplished after the intermediate cooling prior to the hydration of sulfur trioxide. The first mentioned variation however is preferred because the mechanical and thermal load of the catalyst is considerably less. For the removal of the dust according to the first mentioned variation, the use of a high temperature electrofilter is particularly suitable.
A filter of the type mentioned above requires slightly higher investments in comparison to a cold operating electrofilter, but reheating measures and problems which are connected with the catalyst abrasion are avoided. Both embodiments in addition have the advantage that the removal dust is not contaminated with ammonia. Since the desulfurization according to the process of the invention does not produce any gypsum, no new problems of dumping and disposal arise which occur as a consequence of the contamination of the gypsum and an oversupply of gypsum in the market.
In the process according to the invention essentially all catalysts may be used which are suitable for the selective nitric oxide reduction. Examples of these are catalysts that are mixtures of the oxides of titanium, tungsten, vanadium and molybdenum (German patent No. 24 58 888) or catalysts formed of natural or synthetic aluminum silicates, for example, zeolites, or catalysts which contain precious metals of the platinum group. These reduction catalysts are well known in the art.
Also for the oxidation of sulfur dioxide, all suitable conventional oxidation catalyst systems may be used for this purpose. Examples for this are the systems mentioned in Gmelin, Handbook der Anorg. Chemie., (Manual of Inorganic Chemistry), Vol. 9, part A, page 320 et seq. (1975), for example, catalysts containing platinum or vanadium pentoxide or iron oxide. These oxidation catalyst systems are well known in the art.
The catalyst for the nitric oxide reduction and the catalyst for the sulfur dioxide oxidation can be in the form of a honeycomb monolith or in pellet or particulate form. The first mentioned form is preferred because of the lower back pressure and the more simple possibility for the cleaning off of dust.
Within the scope of the invention one or both catalysts can consist completely of catalytically active mass (solid catalyst) or in the case of one or both catalysts, the catalytically active substance can be deposited on an inert, ceramic or metallic body which optionally can be coated in addition with a surface area enlarging oxide layer (carrier catalyst). These forms of the catalyst are known in the art.
The two catalytic reactions carried out preferably in a single reactor may be operated in the temperature range of 250°-550° C., preferably 350°-450°, especially 380°-420° C.
The exhaust gas freed of nitric oxides and leaving the sulfur dioxide oxidation step according to the invention must be cooled intermediately, before the sulfur trioxide formed thereby can be converted with water into sulfuric acid. It has been determined to be favorable to cool this exhaust gas to a temperature of 20°-160°, preferably 70°-150°, especially 110°-140° C. prior to the hydration of the sulfur trioxide.
The hydration of the sulfur trioxide may be carried out in a one- or multistep scrubber with 70-86%, preferably 75-80% by weight of sulfuric acid. Such installation are known from the technology of the sulfuric acid production.
It is advantageous for the hydration of the sulfur trioxide to take place at temperatures of 40°-130°, preferably 95°-125°, especially 100°-115° C.
An advantage of the process according to the invention resides in the compact manner of construction of the waste gas purification installation which is accomplished by the joint arrangement of the nitrification and desulfurization catalysts in the preferred common reactor.
As a result of the downstream location of the oxidation catalyst, a further advantage of the invention resides in the fact that an ammonia leak can be completely avoided in the overall installation, since the small quantity of unused ammonia from the denitrification step is completely oxidized at the oxidation catalyst. The content of the nitric oxide in the purified flue gas will be only slightly raised again as a result. As a consequence of that, all technical problems associated with the ammonia leakage of the conventional flue gas purification installations are omitted, such as for example the corrosion caused by ammonium salt deposits and advance impact on the environment caused by scrubbing waters or discharge of ammonia into the atmosphere.
For the desulfurization, no chemicals are needed except water. The water may be used as such or in the form of concentrated sulfuric acid, whereby H 2 SO 4 may be produced continuously and may be obtained in concentration of 75-80% by weight. The sulfuric acid obtained from the sulfur oxides entails practically no raw material costs and can easily be sold because of its great range of applications in the chemical industry.
The invention will be further described hereinafter and is illustrated by the accompanying drawings wherein:
FIG. 1 is a flow diagram of one embodiment of the invention, and
FIG. 2 is a flow diagram of another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
Removal of dust upstream of the catalysts.
According to FIG. 1, the flue gases emerging from the boiler apparatus (1) are freed of dust in a hot operating electrofilter (2), then an ammonia/air-mixture is introduced into contact with the gases at (3) for admixture and are fed into the combination reactor (4). In the reactor in the direction of flow of the gas there is illustratively shown an array of three layers of monolithic, ceramic honeycomb catalysts (5) disposed one behind the other for the catalytic reduction of nitric oxide in the exhaust gas.
In the same reactor housing (4), there are located downstream three layers of monolithic, ceramic honeycomb catalysts (6) for the sulfur dioxide oxidation. There is a broad range for the permissible distances between the individual catalysts or the catalyst types located in the reactor (4). The dimensions of the spacing arrangement of the catalysts are determined to insure the production of a turbulent transverse movement in the flue gas and avoidance of local mixing or "channeling".
The catalytic reactor (4) is followed downstream by a heat exchanger (7) of conventional design such as for example, a pipe bundle heat exchanger. In the heat exchanger (7), the denitrified gas and the gas containing the sulfur compounds as sulfur trioxide is cooled down to the intended operating temperature of the SO 3 scrubber. The heat conducted away by the heat exchanger (7) serves for the preheating of the combustion air for the boiler combustion. The exhaust gas next passes to the gas scrubber (8), wherein the exhaust gas is converted with water as such or in the form of dilute aqueous sulfuric acid, whereby a higher concentration of H 2 SO 4 is obtained. The scrubber is best operated with sulfuric acid in circulation, which has a concentration which is close to, or equal to the desired final concentration of 75-80% by weight. The completely purified exhaust gas leaving the scrubber may then be discharged into the atmosphere by way of the chimney (9).
Embodiment 2
Dust removal upstream of the sulfuric acid scrubber.
According to FIG. 2, the flue gases emerging from the boiler installation (1) are conveyed in a conduit and at any convenient point (2) are mixed with an ammonia/air-mixture and are fed into the reactor (3). In the reactor (3) in the direction of flow of the gas, there is illustratively arranged three layers of monolithic, ceramic honeycomb catalyst (4) one behind the other for the reduction of nitric oxide.
In the same reactor housing (3) this reduction catalyst arrangement is suceeded downstream, illustratively, by three additional layers of monolithic, ceramic honeycomb catalyst (5) for the sulfur dioxide oxidation reaction. For the spacing of the distances between the individual catalysts, a wide range is contemplated. The spacings have for their purpose the production of a turbulent, transverse movement in the flue gas and thereby avoid loal effects or "channeling".
The catalytic reactor (3) is followed downstream by a heat exchanger (6) such as for example, a pipe bundle heat exchanger. Other conventional heat exchangers can be used. In the heat exchanger, the gas from which nitrogen has been removed and containing the sulfur compounds as sulfur trioxide, is cooled to the selected operating temperature of the SO 3 scrubber (8). The heat which has been carried off thereby serves for the preheating of the combustion air for the firing of the boiler. The dust filter (7) follows downstream from the heat exchangers.
In the scrubber (8), the exhaust gas is converted with water as such or for example in the form of diluted aqueous sulfuric acid, whereby H 2 SO 4 of a higher concentration will be obtained. The scrubber is best operated with sulfuric acid already in circulation which has a concentration close to, or equal to the desired final concentration of 75-80% by weight. The completely purified exhaust gas leaving the scrubber (8) may then be discharged into the atmosphere by way of the chimney (9).
EXAMPLE
The process according to the invention was operated in an apparatus constructed according to embodiment 1 shown in FIG. 1 which was installed into the path of the flue gas of a coal fired heating power plant with heat power coupling connection. Hard coal dust is used as fuel in the heating power plant formed of three water pipe boilers with natural circulation. The combustion load of the boiler amounts to 98 MW. As a result of the heat power coupling, always 18 MWel and 50 MW th are produced and delivered. The quantity of exhaust gas per boiler amounts to 110 000 m 3 (N)/h.
The flue gas for the apparatus was removed downstream from electrofilter which was operated at about 450° C.
The technical data of the pilot apparatus are summarized in Table 1.
TABLE 1______________________________________Technical data of the pilot apparatus______________________________________flue gas throughout 500 m.sup.3 (N)/hdust content in the flue gas 20-50 mg/m.sup.3 (N)following E-filterspace velocity No.sub.x -catalyst 7500 h.sup.-1space velocity oxidation catalyst 7500 h.sup.-1empty pipe velocity in the reactor 3 m/sflue gas temperature 420-460° C.total loss of pressure at the 2400 Pacatalystinlet temperature in the SO.sub.3 - 130° C.scrubberoperating temperatures of the SO.sub.3 - 100-110° C.scrubberSO.sub.3 -removal in the SO.sub.3 -scrubber >95%H.sub.2 SO.sub.4 final concentration 77-80% by weight______________________________________
The NO x -catalyst was made as a carrier catalyst consisting of mullite honeycomb bodies of the dimensions 150 mm×150 mm×150 mm length with a cell density of 16/cm 2 and a zeolite coating of the mordenite type. The zeolite coating of the mordenite type is known.
The oxidation catalyst was made as a carrier catalyst consisting of multiple honeycomb bodies of the dimensions 150 mm×150 mm×150 mm length with a cell density of 16/cm 2 and an α-aluminum oxide coating which contained 2.5 g./dm 3 of platinum in finely distributed form.
The distance between the identical catalysts was fixed at 160 mm and between the two different catalysts was fixed at 200 mm.
After 2000 operating hours, at a mole ratio of ammonia : nitric oxide of 0.9, conversion rates for nitric oxide of greater than 94% could be measured and for sulfur dioxide the conversion was greater than 91%. An ammonia leak could not be proved in any of the cases downstream from the combination reactor.
The data for the flue gas composition with the achieved conversion values are summarized in Table 2.
TABLE 2______________________________________ Concentra-Exhaust Concentration tion Down-Gas Upstream of Stream of Conver- MethodCom- Combination Combi- sion ofponent Catalyst catalyst Values Measuring______________________________________NO.sub.x 380-510 vpm 20-30 vpm >94% chemical lumines- cence methodSO.sub.2 580-640 vpm 50-57 vpm >91% UV spectro- scopeO.sub.2 7-8 vol. % approx. 7 -- paramag- vol. % netic methodNH.sub.3 340-455 vpm not provable quantita- wet- tively chemical absorption and analysis______________________________________
Further variations and modifications will be apparent from the foregoing description and are intended to be encompassed by the claims appended hereto
The German application No. P 36 01 378.1 is relied on and incorporated herein.
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A process is described for the purification of exhaust gases containing oxides of nitrogen and sulfur obtained from combustion installations and industrial production processes by selective catalytic reduction of the nitric oxides with ammonia, subsequent catalytic oxidation of sulfur dioxide with oxygen and conversion into sulfuric acid of the sulfur trioxide obtained.
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BACKGROUND OF THE INVENTION
The present invention discloses an asphalt composition suitable for use in air blowing and the process of air blowing the same, both using sulfonic acids as catalysts.
Air blowing of asphalt is a process by which stock asphalt is converted to an asphalt product having more desirable properties by the forced introduction of air by blowing at temperatures ranging from 400° to 500° F. In its unprocessed forms, asphalt may be unsuitable for particular applications due to excessive brittleness or a too low softening point. The degree of brittleness is referred to as penetration. The modification of the softening point/penetration properties by air blowing permits the manufacturer of the asphalt to specifications otherwise not possible. Additionally, it is well known that the use of a catalyst during air blowing further improves the softening point and penetration of the asphalt. Catalyst use also reduces the time required to bring the asphalt to the desired softening point, a significant economic benefit.
Commonly used and well-known air blowing catalysts, many of which have been patented, include ferric chloride, FeCl 3 , U.S. Pat. No. 1,782,186, phosphorous pentoxide, P 2 O 5 , U.S. Pat. No. 2,450,756, aluminum chloride, AlCl 3 , U.S. Pat. No. 2,200,914, boric acid, U.S. Pat. No. 2,375,117, copper sulfate CuSO x , zinc chloride ZnCl 2 , phosphorous sesquesulfide, P 4 S 3 , phosphorous pentasulfide, P 2 S 5 and phytic acid, C 6 H 6 O 6 (H 2 PO 3 ) 6 . Also useful as catalysts are phosphoric acid H 3 PO 4 and ferrous chloride FeCl 2 , U.S. Pat. No. 4,338,137. By far, the most useful and commonly used of the catalysts are ferric chloride and phosphorous pentoxide.
The primary reason for the popularity of FeCl 3 and P 2 O 5 is the fact that they are readily obtained and relatively inexpensive to use. They do, however, have serious drawbacks. In particular, FeCl 3 when used at the elevated temperatures to air-blow asphalt, produces hydrogen chloride gas, HCl, as a by-product. This gas is not only very corrosive, but can create significant air pollution and healt problems if released into the atmosphere.
Additionally, the use of ferric chloride as a catalyst contributes to two other negative characteristics of the asphalt which raise problems in meeting desired specifications. One characteristic, called skinning, results from the heating of industrial asphalts in the presence of air at elevated temperatures. A tough, insoluble skin is formed on the surface of the asphalt which is extremely insoluble in the asphalt itself. This skin causes problems both to the refiner and the asphalt customer. It has been found that the skinning tendency of the asphalt increases when ferric chloride is used as the catalysts in air blowing.
A second undesirable characteristic resulting from the use of ferric chloride catalysts is known as "fallback". Fallback is a drop in the softening point which air-blown asphalt may undergo when held at a stable elevated temperature. When asphalt is held over time at elevated temperatures, the softening point-penetration ratio reduces or "falls back" outside of the desired specification range even though it is being held at a constant temperature. This may be caused or aggravated by various mixture components, particularly FeCl 3 .
The present invention overcomes both these skinning and fallback problems to a much greater degree than the ferric chloride catalyst which is a known contributor to both problems.
SUMMARY OF THE INVENTION
The present invention comprises an air-blown asphalt composition comprising asphalt and a catalytic amount of an organic sulfonic acid. The sulfonic acid, when used in air-blown asphalt, increases the penetration, at a given softening point resulting in a more industrially desirable asphalt composition. It also allows the use of less desirable crude stocks. Additionally, the catalyst causes the air blowing reaction to proceed at a faster rate, thereby reaching the desired softening point sooner than without the catalyst. Moreover, the use of the organic sulfonic acid does not result in undesirable irritating or corrosive by-products and reduces the amount of skinning and fallback in the final composition.
The organic sulfonic acids may be either aromatic or aliphatic in nature and should possess sufficient carbon atoms to render the catalyst soluble in asphalt. The catalytic amount of sulfonic acid producing the desired result ranges from 0.25 weight percent to 10 weight percent, and the preferred range is 0.5 weight percent to 3 weight percent of the total composition.
DETAILED DESCRIPTION OF THE INVENTION
Organic sulfonic acids are introduced into asphalt as a catalyst for air blowing. The sulfonic acids are added in an amount from about 0.25 weight percent to about 10 weight percent of the total catalyzed asphalt composition. In the preferred embodiment of the invention the sulfonic acid catalyst comprises from about 0.5 weight to about 3 weight percent of the total composition. The sulfonic acids accelerate the speed with which the air blowing reaction proceeds to the desired specifications and results in equivalent or higher penetrations at the desired softening point than other catalysts, and considerably higher penetration than with no catalyst. Additionally, the sulfonic acid catalysts minimize skinning and fallback tendencies of the asphalt and eliminate the evolution of corrosive or essentially harmful vapors, such as HCl.
The asphalt stock suitable for use can be of varied character. Any petroleum residua or flux, remaining following the separation of vaporizable hydrocarbons through lubricating oil fractions or any relatively high molecular weight extract obtained from petroleum refining or virgin, naturally occurring asphalt can be used. For example the residua from Alaskan North Slope/Waxy Light Heavy crude blend, Arabian Heavy crude, Arabian Light crude, and the like, can be used. Of course, the difference in the asphalt stock will result in different properties in the finished air blowing asphalt. The organic sulfonic acids finding use in this invention include both alkyl sulfonic acids and aromatic sulfonic acids. The alkyl substituent may be the straight, branched, or cyclic and may be exemplified by the formula:
R--SO.sub.3 H
where R is an alkyl substituent of not more than 1 to 20 carbon atoms. Examples of suitable alkyl sulfonic acids include: methane sulfonic acid, ethan sulfonic acid, t-butane sulfonic acid, 2-propane sulfonic acid and cyclohexyl sulfonic acid. The R substituent R group may also include alkene groups, the catalyst then being an alkene sulfonic acid. By "alkene" in this sense is meant not only true, i.e. essentially all alkene sulfonic acids, but also those alkene sulfonic acids made by reacting an olefin, preferably an alpha-olefin, with SO 3 . The resulting composition is a mixture of compounds and is a commercially available product made by the above reactions consisting of pure alkenes and dimers thereof. Examples include: alpha-olefin sulfonic acid, dimerized alpha-olefin sulfonic acid, and 2-hexene sulfonic acid.
The sulfonic acid catalysts may also consist of aromatic sulfonic acids wherein the aromatic portion of the composition is either benzene or naphthalene. The aromatic compositions are exemplified by the formulae: ##STR1## wherein R may be any straight or branched alkyl substituent having from 1 to 20 carbon atoms or hydrogen; and n is either 1 or 2. The R groups are separate and independent and may be in any position para, ortho, or meta to the SO 3 H group on the ring containing the SO 3 H group. It has been noted that the longer the chain on the R groups, the more soluble the catalyst is in asphalt. However, it is also noted that catalytic activity was found to decrease with the increased length of the alkyl substituent. Examples include: benzene sulfonic acid, para-toluene sulfonic acid and naphthalene sulfonic acid.
The preferred sulfonic acid catalyst is para-toluene sulfonic acid (HPTS); molecular weight 163, and formula: ##STR2## Other sulfonic acids which may be used include light alkane sulfonic acid, ("HLAS") which is a mixture of t-butyl and t-amyl benzene sulfonic acids, MW 242; alkane 56 sulfonic acid (Chevron trade name), "HA 56 S"; consisting essentially of polypropylene benzene sulfonic acid wherein the number of propylene carbons is essentially 6 to 16, MW 256-396; and alkane 60 sulfonic acid (Chevron trade name) "HA 60 S", consisting essentially of polypropylene benzene sulfonic acid wherein the number of carbons of the propylene is essentially 6 to 18, MW 256-424.
The composition is formulated by heating asphalt to a temperature of about 200° to 350° F. and thoroughly mixing the sulfonic acid catalyst in the asphalt prior to air blowing. Thereafter the asphalt-sulfonic acid composition is air-blown in accordance with procedures known in the art, such as those taught in U.S. Pat. Nos. 2,450,756, 2,762,755, and 3,126,329, said patents incorporated herein by reference.
More specifically, the asphalt is heated to a temperature of from about 400° F. to about 550° F. and air, oxygen or an oxygen-inert gas mixture is bubbled or blown through the composition for sufficient time to achieve a desired softening point. Generally, the air blowing operation is carried out for a period of from about 0.5 hour to about 12 hours.
Having described the invention, the following examples are intended to be illustrative and not limit the scope of the invention.
Additionally, the following examples were carried out in two different related apparatus systems. In one, the so-called "mini-still", a laboratory scale situation was used, employing approximately 250 to 300 grams of the asphalt material. In the second, a pilot plant scale asphalt-turbo-still, an approximately 3000-gram capacity sample was employed. The two methods correlated well and their results are as illustrated in the tables following the examples.
EXAMPLES
Example 1
In this example, the mini-still apparatus was employed using a Glas-Col heating mantle surrounding a one quart metal container, a heat control unit with thermocouple, a stirrer with Cowles blade attached, and an air supply connected to a 1/8 inch air line into the air blowing container. 250 grams of air blowing asphalt flux into which 1.0 weight percent of para toluene sulfonic acid was added, was placed in a one-quart metal container and covered with aluminum foil. The container and contents were heated to 325° F. for approximately one hour. The stirrer and air line were introduced into the container with the stirrer placed such that the Cowles blade just misses touching the bottom of the container. The stirring was begun and the temperature controller was increased to 400° F. A nitrogen line was introduced through the container cover, blanketing the surface of the asphalt with inert nitrogen gas. The stirrer was set at a speed such that turbulence and oxidation were introduced into the asphalt flux mixture, contributing to the air-blown effect. The temperature was gradually increased to 500° F. and the speed of the stirrer set at approximately 850 rpm. Air was introduced at approximately 120 cc per minute (one-half of the air rate used in the turbo-still). At points through the test run, samples were taken for softening points. The time it takes to reach 220° F. softening point was also noted. It took 103 minutes to reach the 220° F. softening point, at which point the composition was tested for and had a penetration of 14 decimillimeters (dmm) at 77° F.
FURTHER EXAMPLES
Further examples were carried out in accordance with Example 1 in both the mini-still and pilot plant apparatus using para-toluene sulfonic acid, alkane 56 sulfonic acid, alkane 60 sulfonic acid, and ferric chloride FeCl 3 .6H 2 O and no catalyst for comparison. The results of those experiments are outlined in Table I and the comparative examples in Tables II and III.
For those experiments not using the mini-still, a 3000-gram capacity asphalt turbo still pilot plant was used which employs a temperature control vessel fitted with high speed rotostatic mixer providing excellent contact with injected air. The metered air was injected by tubing passing through the temperature-controlled asphalt and discharged directly below the mixer located at the bottom of the vessel. The still was also provided with an overflow vent for offgases and entrained material and has a sampling and drain valve through which samples were taken. The runs in the asphalt turbo-still pilot plant were conducted in essentially the same manner as those in the mini-still. Penetration, viscosity and softening point were tested for, as a function of time. The only difference noted being that most catalyzed runs took a somewhat shorter time to reach the 220° F. softening point in the mini-still, presumably due to the increased volume of material.
TABLE I.sup.1______________________________________ Time to Reach 220° F. Softening Penetration.sup.2Example Catalyst Wt. % Point (Min.) (dmm @ 77° F.)______________________________________1 HPTS 1.0 136 142-M HPTS 1.0 103 143 HPTS 3.02 124 194 HPTS 1.53 129 195 HPTS 0.98 136 146 HPTS 0.49 151 127 HPTS 1.5 113 158 HPTS 3.0 113 149 HA.sub.56 S 1.0 141 1110-M HA.sub.56 S 1.0 94 911 HA.sub.60 S 1.0 144 1012-M HA.sub.60 S 1.0 109 9______________________________________ .sup.1 Examples labeled "M" were run in the ministill apparatus. All others used the turbostill. .sup.2 Estimated penetrations at a 220° F. softening point.
COMPARATIVE EXAMPLES--FeCl 3 .6H 2 O
The procedures outlined for Example 1 were carried out with respect to the examples outlined below Table II using FeCl 3 .6H 2 O substituted for the sulfonic acids in an amount of 0.35 weight percent.
TABLE II.sup.1______________________________________ Time to Reach 220° F. Softening Penetration.sup.2Example Catalyst Wt. % Point (Min.) (dmm @ 77° F.)______________________________________A-1 FeCl.sub.3.6H.sub.2 O .35 101 16A-2 FeCl.sub.3.6H.sub.2 O .35 111 13A-3-M FeCl.sub.3.6H.sub.2 O .35 71 14A-4-M FeCl.sub.3.6H.sub.2 O .35 89 16______________________________________
COMPARATIVE EXAMPLES--No Catalysts
The procedures outlined with respect to Example 1 were again carried out, however, no catalyst was added to the asphalt. The results of these examples are tabulated below.
TABLE III.sup.1______________________________________No Catalyst Time To Reach 220° F. Penetration.sup.2Example Softening Point (Min.) (dmm @ 77° F.)______________________________________B-1 160 9B-2 152 11B-3M 187 6B-4M 179 6B-5M 183 7______________________________________
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A process for air blowing asphalt in the presence of organic sulfonic acids and an asphalt composition comprising a major amount of asphalt and a minor but effective amount of organic sulfonic acid.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a rotary flexible coupling consisting of an even number of driver blocks which have end faces extending in the radial direction as well as fastening elements for alternatingly connecting suitably designed connecting elements of input and output flanges.
2. Prior Art
A flexible coupling of the above-mentioned type is described in German patent publication No. 22 34 437, which shows driver blocks with rubber columns between them. The columns, which extend in the circumferential direction and connect end faces of the blocks located opposite each other, extend essentially parallel to the axis of rotation of the driver blocks. As a result, the transmission of the torque introduced is limited substantially to that portion of the rubber columns which is stressed in compression and, therefore, to about 50% of all the rubber columns provided. The resulting weight and dimensions with respect to transmitting a given torque are therefore extremely unsatisfactory.
In addition, the rubber columns must be designed so that the nominal torque can be transmitted nondestructively. Such a design, however, requires that the rubber columns have a very stiff and inelastic characteristic when transmitting very low torques, which is extremely undesirable for use in the power train of a motor vehicle. It is also a drawback that overloads, which can never be precluded in such applications, can lead directly to the destruction of, or at least to damage to, the rubber columns.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the invention to develop a rotary flexible coupling, which is especially for use in the power train of a motor vehicle and which has a particularly soft and resilient spring characteristic when transmitting low torques.
Another object is to provide a rotary flexible coupling that ensures good attenuation of vibrations.
A further object is to provide a rotary flexible coupling which can be highly overloaded without the danger of damage.
In accordance with the invention, a rotary elastic coupling of the type mentioned at the outset is provided with fastening elements and connecting elements that have mutually engaging projections which extend in the axial or radial direction or both. Two tires of inelastic material are located radially inside and outside the driver blocks, and the driver blocks, which have a circular-ring sector-like profile, are each connected to the tire by a layer of elastomeric material.
The driver blocks are not connected to each other by rubber columns but are each connected in the radial direction both inwardly and outwardly, to the inelastic tires, and thereby to each other, by a layer of elastomeric material. The tires are designed to be stiff in themselves; they consist preferably of metal. The torque applied to the coupling is transmitted by generating a shear stress in the rubber layers, so that the structural dimensions can be kept small due to the uniform stress of all layers.
In the no-load condition or when small torques are being transmitted, the layers have a particularly soft elastic behavior and, as a result, the clutch has a soft spring characteristic. If greater torques or very heavy overhoads occur, then the opposing end faces of the driver blocks move so that they lie directly on each other, and a form-locking connection between the input and output shaft is obtained without danger of damaging the layers. Adequate safety with respect to the use of rubber mixtures is obtained if the thickness of each layer is about 0.7 to 2.5 times the mutual distance of the end faces of the driver blocks at the outside or inside circumference, respectively. The end faces of the driver blocks are planar and are in a plane coinciding with the axis of rotation. The absolute value of the thickness of the layer of the rubber-elastic material between the driver blocks and the inner tire is smaller, corresponding to the smaller distance from the axis of rotation, than the absolute value of the thickness of the layer between the driver blocks and the outer tire.
The radial elastomeric intermediate layers are preferably designed so that equal stresses of these layers are obtained.
The succeeding driver blocks are alternatingly connected in rigid form to the input and output flanges in order to prevent the blocks from being twisted or canted when torque is being applied. The fastening and connecting elements which can be considered must be designed accordingly, and they preferably have mutually engaging projections that extend axially or radially. The input and output flanges can be bolted, for instance, to the driver blocks, and a single screw per driver block may be sufficient for that purpose if it is properly arranged. With respect to the transmission of greater torque or heavier vibrations, on the other hand, it is better to use either two screws parallel to each other in each driver block or to arrange at the driver block an additional projection that extends in the axial direction and engages in a corresponding recess of the input or the output flange.
The layers of the elastomeric material must be connected firmly to the tires inside and outside of the driver blocks. A very strong bond of this kind can be produced by direct vulcanization. However, this should not preclude the possibility of fabricating the layers independently of the tires and the driver blocks and joining all parts together in the manner proposed by a final assembly operation. In particular, that makes the generation of an elastic pre-tension within the layers in the radial direction possible in a particularly advantageous manner. The mutual spacings of the individual driver blocks can be determined with a corresponding design by using additional adhesives in the region of the contact surfaces or by arranging radial projections at the tires and the layers so that the layers and the driver blocks are fixed in a given geometric position.
The surfaces that define the driver blocks and the tires in the radial direction and face the layers can be made spherical in the same sense. As a result, the buckling elasticity can be substantially improved, which makes it possible to use the proposed structure also for shafts that are not aligned.
The angle which is enclosed by respective opposite end faces of the driver blocks can be alternately small and large in regularly recurring form. This gives the proposed coupling different elasticity depending on the direction of rotation, which has a positive effect, particularly with respect to its use in the power train of a motor vehicle. For forward operation, this train should have particularly large elasticity, which is not always necessary to the same extent for reverse travel. The proposed coupling connects the one feature with the other, since it has been found to be particularly advantageous if the ratio of the large angle to the small angle is between 1.5 to 4. Within this ratio range, satisfactory travel comfort is achieved in forward travel as well as in reverse travel.
In order to prevent noise from developing when the end faces of the driver blocks hit on each other, it is proposed to provide at least one each of these opposing surfaces with a buffer layer of an elastically resilient material. The buffer layer may consist of an elastomeric material and may be cemented to the respective end face. However, it has been found to be preferable for mass production to produce the buffer layer by forming-on and vulcanizing in the same operation and in the same tool as the layers of the rubber-elastic material between the driver blocks and the outer and inner tires. In general, it does not increase the cost, and it offers considerable advantages, if the buffer layer is incorporated on both end faces of the driver blocks so that a continuous coating of the elastomeric material is obtained on all surfaces extending parallel to the axis of rotation of the coupling.
The thickness of the buffer layers can be small and, in general, it is sufficient if the surface is a plane surface aligned in all regions toward the axis of rotation of the coupling. By such a design alone, noise development that would otherwise result when the metal driver blocks struck each other is prevented. Because of the form-locking clamping of the plane buffer layers, which applies in this load situation, and is in the radial direction between the tires and in the circumferential direction between the end faces of the driver blocks, the latter exhibits little elastic resiliency, which causes a spontaneous increase of the spring stiffness. Such a spontaneous increase which could lead under certain conditions to damage of connected machine parts, can be prevented if the surface of the buffer layers has one or more bulges that extend in the circumferential direction and may be, for instance, of spherical shape. The height of the bulges is preferably chosen so that the steep spring characteristic, which prevails under the load conditions mentioned and results from the high degree of deformation of the rubber layers, is changed uniformly, avoiding a sharp break point, into an again substantially steeper curve. Even forces resulting from shock loads are thereby intercepted uniformly.
The design of the proposed coupling, in which the driver blocks have spacings of different size in the circumferential direction by pairs, can be used in pairs to particular advantage in the power train of a motor vehicle, in which the driver blocks of a first coupling are connected on the output side to the driver blocks of a second coupling so that the large spacings of the second coupling are opposite the small spacings of the first coupling. In such an arrangement, the properties of both couplings add in a particularly advantageous manner, and in addition to good insulation of vibrations that are introduced with small torques, good damping of vibrations that occur in the transmission of greater torques is achieved.
In addition to the advantageous dynamic properties mentioned, the proposed coupling has the advantages of having small dimensions and low weight. The latter can be reduced to a minimum if aluminum is used for the driver blocks and the tires.
The proposed coupling has an excellent centering effect with respect to the shaft ends connected to it. This facilitates installation of the coupling and it is an advantage worth emphasizing that the occurrence of centrifugal forces influences neither the effectiveness nor the operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a front view of a coupling in which the driver blocks have spacings of different size by pairs.
FIG. 2 is a longitudinal cross-sectional view of the coupling according to FIG. 1.
FIG. 3 shows another embodiment, in which the surfaces of the driver blocks and the tires facing the rubber layers are rounded convexly in the same sense.
FIG. 4 shows a coupling with bulges on the buffer layers.
DETAILED DESCRIPTION OF THE INVENTION
The coupling shown in FIG. 1 consists of an inner tire 1, an outer tire 2, and driver blocks 3 arranged in the space between them. These parts consists of metallic material, such as aluminum, for example, and are connected to each other by vulcanizing an elastomeric material arranged in layers in the spaces in between them to form an outer layer 4 and an inner layer 5. A layer of the cross-linked elastomeric material is vulcanized onto the end faces 6 of the driver blocks 3, and the front side of this layer is in a plane directed toward the axis of rotation of the coupling.
The driver blocks 3a are rigidly connected to an input flange which is not shown, while the driver blocks 3b are connected to an output flange, which is also not shown. The coupling is arranged generally in the axial direction between the input and output flanges, and these flanges are preferably also rotationally symmetrical, which, of course, has no influence by itself on the operation of the proposed coupling.
The operation of the coupling will now be described.
If a clockwise torque is introduced via the input flange into the driver blocks 3a, a clockwise shear stress results in the layers between the driver blocks and the inner and outer tires. The force introduced is transmitted by the latter to the layers between the tires and the driver blocks 3b and from these to the output flange connected thereto. The shear stress in the layers between the driver blocks 3a and the tires is therefore identifical with that between the driver blocks 3b and the tires, and the respective deformations are accordingly the same. The excursion of each individual block from its neutral position is accordingly identical.
If a still greater torque is introduced, increasing deformation of the layers 4 and 5 results.
With greater torques or with overload that occurs suddenly, the surfaces of the buffer layers facing each other make contact at the end faces. Since these are prevented from expanding in the radial direction inward and outward by the tires and in the circumferential direction by the end faces of the driver blocks, they are not able to deform very much, and the applied torque is transmitted directly by the driver blocks.
The driver blocks have spacings of different size by pairs. As a result, if force is introduced opposite the direction of applied torque, only relatively less elastic deformation of the layers is possible. Such a reduction, however, is generally not in the way of using the coupling in the power train of a motor vehicle because the range of loads occurring in reverse travel is substantially less than for forward travel.
The driver blocks have a cylindrical recess which is parallel to the axis of rotation and which has a bushing 8 therein for antirotationally anchoring the input and output flanges, respectively. The bushing has a serration at its end face to engage a corresponding serration of the input or output flange.
The elastomeric layers 4 and 5 are each almost separated into circular segments between the tire 1 and each of the blocks 3 and between each of the blocks 3 and the tire 2, respectively. However, the layers 4 and 5 can be continuous.
There is a radial buffer element of elastomeric material extending along each radial end surface of each of the blocks 3. It will be noted that the angular distance α between the buffer element on the clockwise facing radial surface of each of the blocks 3a is spaced from the buffer element on the counterclockwise facing radial surface of each of the blocks 3b is greater than the angular distance β between the buffer element on the clockwise facing radial surface of each block 3b and the buffer element on the counterclockwise facing surface of each block 3a. The ratio of the magnitude of α to β is with the range of approximately 1.5:1 to approximately 4:1, with the larger angle α being between those surfaces of the buffer elements that would be pushed relatively toward each other in driving the vehicle forward and the angle β being between those buffer elements that would be pushed relatively toward each other in driving the vehicle in reverse.
Further, it has been found to be preferable to have the radial thickness of the layers 4 and 5 to be approximately 0.7 to 2.5 times the mutual distance of the radial end surfaces of the blocks 3 at the outside and inside circumference, respectively.
FIG. 2 shows the coupling in FIG. 1 in a longitudinal section to illustrate that the layer 4 arranged on the outside in the radial direction can have a greater axial length than the layer 5 that is located radially within the driver blocks 3. As a result of these relationships, the outside dimensions can be reduced or, with the same outside diameter, the elastically transmittable torques can be increased. It should be attempted, however, to keep the specific stresses in the cross-section of the outer layers 4 and the inner layers 5 so that they are of a comparable order of magnitude.
FIG. 3 shows another embodiment of the coupling in which the surfaces defining the driver blocks and the tires in the radial direction facing the layers are made spherical in the same sense. As a result the elasticity is much improved if the connected shafts connected to the coupling, but not shown, are arranged at an angle. To a limited degree, gimbal properties are also obtainable.
In FIG. 4, an embodiment is shown in a front view in which one of the buffer layers arranged opposite each other at a spacing is provided with a spherical bulge that extends circumferentially in the center of the end face. This mitigates the steep rise of the spring characteristic for form-locking force transmission. Instead of a single bulge, a multiplicity can also be provided and the bulges may also have a different shape, for instance, they may be in the form of ribs. In view of their purpose, however, the preferred shape of the bulge in all cases is similar to a bell curve.
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A rotary flexible coupling has two interleaved sets of input and output driver blocks connected to input and output flanges, respectively. First and second tires of inelastic material are spaced radially inwardly and radially outwardly from the blocks. Each block is connected to each tire by a cylindrical segment of a cylindrical layer of elastomeric material and torque is transmitted from the input blocks to the output blocks via the elastomeric layers and the tires.
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TECHNICAL FIELD
[0001] This disclosure relates to a treated fabric that is comprised of splittable conjugate yarns and to a process for modifying such a fabric to enhance its water absorbency. Specifically, the present invention relates to a consolidated nonwoven fabric containing continuous filaments comprised of polyester and polyamide components, in which portions of at least one of the components have been removed. The process used to remove portions of the polyamide component involves treating the fabric with acid. A basic solution is used to remove portions of the polyester component of the fabric. The result, using either or preferably both treatments, is a nonwoven fabric with a much greater ability to absorb water. Contemplated end uses of such a treated fabric are also provided.
BACKGROUND
[0002] As will be discussed herein, the present process is applicable to any conjugate yarn that includes a polyamide as one of its components. The present process improves the absorption characteristics of fabrics of any construction (woven, knit, or nonwoven) that are comprised of microdenier yarns that result from splitting conjugate multi-component yarns. Microdenier fabrics are traditionally created by mechanically or chemically splitting a conjugate yarn into its elementary filaments. Although the benefits of this process are readily apparent on a specific nonwoven fabric that will be discussed in detail herein, it should be understood that it is equally applicable to woven or knitted microdenier fabrics created from splittable yarns.
[0003] Nonwovens are known in the industry as an alternative to traditional woven or knit fabrics. To create a nonwoven fabric, a fibrous web must be created and then consolidated. Staple fibers are formed into a web through the carding process, which can occur in either wet or dry conditions. Alternatively, continuous filaments, which are formed by extrusion, may be used in the formation of a web. The web is then consolidated and bonded by means of needle-punching, point-bonding, chemical bonding, or hydroentangling. A second bonding technique may also be employed.
[0004] A preferred substrate for the present disclosure is a nonwoven formed of continuous splittable filaments that are extruded as a web and then consolidated. The continuous conjugate filaments are obtained by means of a controlled spinning process. The continuous filaments have the following characteristics: (1) the continuous filaments are comprised of at least two elementary filaments and at least two different fiber types; (2) the continuous filaments are splittable along at least a plane of separation between elementary filaments of different fiber types; (3) the continuous filaments have a filament number (that is, titer or yarn count) of between 0.3 dTex and 10 dTex; and (4) the elementary filaments of the continuous filament have a filament number between 0.005 dTex and 2 dTex. Simply put, the nonwoven fabric can be described as a nonwoven fabric made from conjugate filaments. Such a fabric is described in U.S. Pat. Nos. 5,899,785 and 5,970,583, both to Groten et al., each of which is incorporated herein by reference.
[0005] A wide range of synthetic materials may be utilized to create the elementary filaments of the continuous conjugate filaments. The conjugate filaments used the present process differ from those common in the art in that they are comprised of elementary filaments of different polymer types. Such polymer types may include polyesters, polyamides, polyolefins, polyurethanes, and the like.
[0006] However, the present invention is intended to improve the characteristics of fabrics that contain polyesters or polyamides as part of the conjugate yarns. As such, the group of polymer materials forming the elementary filaments is selected from among the following groups: polyester and polyamide; polyolefin and polyamide; polyurethane and polyamide; polylactic acid and polyamide; polyester, polyolefin, and polyamide; and polyester, polyolefin, polyurethane, and polyamide; or any other combination as may be known in the art.
[0007] It is desirable in the nonwoven fabrics described above to fully split, or separate, the elementary filaments of the continuous filaments from one another. The same goal applies to woven or knitted fabrics as well. The resultant microdenier strands contribute to the textile quality of the nonwoven fabric. The microdenier yarns contribute to the softness and hand of woven or knitted fabrics.
[0008] However, the fabric described in the above-referenced patents is not as absorbent as many other synthetic fabrics that may be used in the drying or wiping cloth market and that may have a similar composition but different construction. The nonwoven of the present disclosure is more absorbent after being subjected to the present process.
SUMMARY
[0009] In a preferred embodiment, the present process involves subjecting a fabric having splittable conjugate yarns both to an acidic treatment and to a basic treatment, each of which erodes a portion of the components of the conjugate yarns. The acid treatment, given certain reaction kinetics, removes a portion of the polyamide element of the conjugate filament. The basic treatment has a similar effect on the polyester element of the conjugate filament, making it more hydrophilic. The at least partial removal of the polyamide component, coupled with the increased hydrophilicity of the polyester component, results in a fabric having enhanced absorptive properties. In an alternate embodiment, treatments with only acid or only basic solution may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The following photographs were taken with a Hitachi Camera, Model VK-C350, after having been magnified through an Olympus BH2 optical microscope. The following photographs are of various fabric cross-sections.
[0011] [0011]FIG. 1 is a photograph, taken by an optical microscope at a magnification of 1060×, of a nonwoven fabric that has been dyed but not subjected to the present process;
[0012] [0012]FIG. 2 is a photograph, taken by an optical microscope at a magnification of 1060×, of a nonwoven fabric that has been subjected only to the acid treatment of the present process;
[0013] [0013]FIG. 3 is a photograph, taken by an optical microscope at a magnification of 1060×, of a nonwoven fabric that has been subjected only to the basic treatment of the present process;
[0014] [0014]FIG. 4 is a photograph, taken by an optical microscope at a magnification of 1060×, of a nonwoven fabric that has been subjected to a 0.25% acidic treatment and a basic treatment; and
[0015] [0015]FIG. 5 is a photograph, taken by an optical microscope at a magnification of 1060×, of a nonwoven fabric that has been subjected to a 2.0% acidic treatment and a basic treatment.
DETAILED DESCRIPTION
[0016] The present product is created by subjecting a fabric comprised of splittable continuous conjugate filaments to successive treatments with acid and base. The resultant treated fabric has enhanced ability to absorb water, as compared with the untreated fabric and other drying cloths made of similar synthetic materials.
[0017] The present process includes the steps of: (a) treating the fabric with acid and rinsing; and (b) treating the fabric with base and rinsing. In one preferred embodiment, before treatment with acid or base, the fabric is subjected to high pressure hydroentanglement, as described in U.S. patent application Ser. No. 09/344,596, filed Jun. 25, 1999, which is commonly owned and is hereby incorporated by reference.
[0018] The term “polyamide” is intended to describe any long-chain polymer having recurring amide groups (—NH—CO—) as an integral part of the polymer chain. Examples of polyamides include nylon 6, nylon 6 6, nylon 1 1, and nylon 610.
[0019] The term “polyester” is intended to describe any long-chain polymer having recurring ester groups (—C(O)—O—). Examples of polyesters include aromatic polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polytrimethylene terephthalate (PTT) and aliphatic polyesters such as polylactic acid (PLA).
[0020] In one embodiment, the conjugate filaments present, in cross-section, a configuration of zones representing the cross-sections of the different elementary filaments in the form of wedges or triangular sections. Such a shape is clearly identifiable in the central area of FIG. 1, which shows a circular cross-section having narrow, dark wedges between wider wedges. The dark wedges represent the polyamide component of the conjugate filament, while the wider, lightly colored wedges represent the polyester component of the conjugate filament. As may be realized, the percentage of polyester in the conjugate filament is larger than the percentage of polyamide. Distributions of polyester to polyamide range from 95-5 to 5-95, with 65-35 being a typical distribution by weight.
[0021] A review of FIG. 1 shows a plurality of polyester wedges that have been dislodged from their multi-component “packages.” Slightly above and to the left of the central circular package is a cross-section in which some polyester wedges have been dislodged, but the polyamide skeleton remains largely intact. A similar structure, but with more polyester wedges removed, is visible in the lower left corner of the photograph.
[0022] Several items should be noted, upon review of a representative photograph of the nonwoven's composition. First, while the core portions of the conjugate filaments are shown as polyamides, no core portion is required. In fact, hollow core conjugate filaments are also suitable for use in the present process, particularly since such hollow filaments are more likely to fully split. Furthermore, cores made of polyester or fibers without a recognizable “core” would be suitable as well.
[0023] Second, it should be noted that FIG. 1 is a photograph of a piece of untreated nonwoven fabric. The fabric shown in FIG. 1 was processed as described above, by extruding a web and then consolidating the filaments of the web. The fabric was then subjected to the conditions of the present process, but without the addition of the acid or the basic treatment. That is, the fabric was tumbled in a jet dye machine for 90 minutes at 130° C., cooled, rinsed, tumbled in a jet dye machine for 30 minutes at 130° C., cooled, rinsed, and then dyed. From the photograph, it is clear that merely tumbling the fabric during processing does not affect the desired filament splitting.
[0024] The object of the consolidation process is to fully split the different elementary filaments from one another. It is clear from the photograph that some multiple-component filaments remain. The fact that hydroentanglement alone is insufficient to separate the elementary filaments points to a need for additional processing, as is described herein.
[0025] Finally, the photograph shows a symmetrical cross-section of the conjugate filament, having a central median axis. In fact, the median axis of the conjugate filament can be positioned at a point other than the central line of the filament. The conjugate filament can be unsymmetrical, having elementary filaments with non-uniform cross-sections. The cross-section of the conjugate filaments can be substantially circular in shape or can be comprised of multiple lobes that are joined at a central region. Another variation of the construction of splittable conjugate filaments are those having a cross-section in which ribbons, or fingers, of one component are positioned between ribbons, or fingers, of a second different component. Yet another variation includes either one or a plurality of elementary filaments of one material that are integrated in a surrounding matrix of a second different material.
[0026] It is understood in the art that polyamides, such as nylon, can be etched—that is, partially eroded—by subjecting such fibers to acidic solutions. One example of an etching treatment is found in U.S. Pat. No. 4,353,706 to Burns, Jr. et al., which is commonly owned and is hereby incorporated by reference. The objective of the present process, unlike that of Burns, Jr. et al., is not to produce a sculptured pile fabric, but to produce a fabric more capable of absorbing water.
[0027] Both strong and weak acids are useful in the present process. Examples of common strong acids include sulfuric, phosphoric, nitric, and hydrochloric acids. Weak acids may also be employed in the present process including organic acids, such as formic acid, and sulfonic acids, such as benzene sulfonic acid; naphthalene sulfonic acid; ortho-, meta-, and para-toluene sulfonic acids; and alkylated aromatic sulfonic acids wherein the alkyl group may be straight chain or branched chain and may contain from one to about 20 carbon atoms. Preferably, the weak acids useful in the present process have a pKA value of from about 0.1 to about 2.0, preferably from about 0.4 to about 1.0. More preferably, paratoluene sulfonic acid (PTSA) is often used for the present process, because of the relative ease with which its corrosive properties may be controlled.
[0028] To determine the necessary reaction conditions, one must consider the kinetics and diffusion processes involved in the reaction. In general, the mass transport rate of the acid or base reactant to the polymer, the reaction rate of the reactant with the polymer, and the mass transport rate of the degraded polymer out of the fiber matrix are factors which affect the rate of reaction. The mass transport rate of the reactants is largely affected by the concentration of the reactant, the temperature, and the rate of liquid movement during the reaction process. The introduction of phase transfer catalysts, which transfer reactants from the liquid interface into the polymer, can also affect the reaction rate. The reaction rate is generally proportional to the concentration of acid or base reactant, the concentration of the polymer reactant, the temperature during the reaction, and the presence of any catalyst. The rate of mass transport of degraded polymer is affected by the concentration of degraded polymer, temperature, rate of liquid movement during the reaction process.
[0029] It has been found that subjecting the fabric to either an acidic solution or a basic solution increase the treated fabric's ability to absorb water. However, subjecting the fabric to both an acidic solution and a basic solution results in a fabric having greatly enhanced absorption capacity.
[0030] A particularly effective range of concentrations, when using PTSA, are concentrations greater than about 1% of the weight of the bath (owb), though improvements in water absorbency have been realized with concentrations as low as about 0.25% owb. More preferably, when using PTSA, the range is from about 1% to about 3%, based on the weight of the bath. Most preferably, when using PTSA, the acid concentration is about 2%, based on the weight of the bath. Obviously, different concentrations may be desirable for different acid types, such as organic or strong.
[0031] Exposure times, again using PTSA, can range upwards from about 30 minutes to about 120 minutes. The preferred exposure time is about 90 minutes, when a 2% concentration of PTSA is used. Strong acids or higher acid concentrations would likely require a shorter exposure time, while organic acids might need longer periods over which to effect the desired fiber modifications.
[0032] The acid selectively targets the polyamide components of the nonwoven fabric. Where the conjugate filaments have been at least partially split during hydroentanglement, the acid tends to further split the filaments into their elementary components and to erode the polyamide components. This result is due to the acid's preferential affinity for polyamides. Where conjugate filaments are not split, there is a tendency for the polyamide components to be dissolved or eroded by the acid, while the relative grouping of the components may remain largely unchanged (see FIG. 2).
[0033] [0033]FIG. 2 is a photograph of a nonwoven fabric that has been subjected only to an acidic solution (where the acid concentration was about 2% owb). In the central area of the photograph, a composite structure is visible in which most of the polyamide components of the conjugate filament have been removed. Only three dark-colored polyamide components remain between the polyester components. Below and to the left of the central circular structure are individual polyester wedges that have been separated from neighboring polyamide wedges. Because of the concentration level used, there appear to be no individual polyamide wedges. The polyamide portions appear to have been completely eroded.
[0034] Due to the dissolution of at least some of the polyamide components of the fabric, the resulting fabric has a decreased weight, typically on the order of about 2 to about 25%. The resulting fabric also has improved water absorption characteristics, although those characteristics are further enhanced by a subsequent basic treatment as described below.
[0035] Following acid treatment, the fabric is then subjected to a basic treatment. The basic solution reacts with the polyester component of the conjugate filament, making it more hydrophilic. The term “basic” is intended to describe the hydroxides of any alkali or alkaline earth metal and amines. The preferred basic solutions are sodium hydroxide (NaOH) and potassium hydroxide (KOH), with sodium hydroxide being more preferred because of cost. Amines are less preferred because of their tendency to react with the entire fiber rather than the surface of the fiber.
[0036] Additionally, a phase transfer catalyst may be used to affect the reaction rate. Commonly, alkyl quaternary salts are used. Such salts often have a carbon chain length of about 16.
[0037] The preferred concentration for the basic solution is significantly less than that of the acidic solution. In fact, a concentration range from about 0.025% to about 0.10% (based on the weight of the bath) is sufficient to create the desired modifications in the polyester components. Preferably, the concentration of the basic solution is about 0.050% based on the weight of the bath. It has been found that higher concentration levels of the basic solution may be used. Such concentrations may result in a weakened fabric, loss of textile quality, and resemblance to a paper-type product.
[0038] Exposure times, using sodium hydroxide, can range from about 15 minutes to about 90 minutes. The preferred exposure time is about 30 minutes, when a 0.050% owb concentration of sodium hydroxide is used. The base selectively targets the polyester components of the fabric and, specifically, the ester groups. The base hydrolizes the ester bonds in the polyester, creating hydrophilic cites. These cites make the polyester more hydrophilic and the surface of the polyester becomes more water-loving.
[0039] Again, the fabric that has been treated only with base has improved water absorption characteristics as compared with the untreated fabric, although the improvements are not as significant as those realized with a combination of acid and basic treatments. FIG. 3 is a photograph of a nonwoven fabric, as described herein, in which the fabric has been subjected only to a basic solution. In this photograph, a number of joined polyamide clusters are visible. Individual polyester wedges seen in earlier photographs are also present and separate from the polyamide skeletons. As compared with FIG. 2, there appears to be little, if any, degradation in the polyamide component. This is expected because the basic solution targets only the polyester component.
[0040] It has been found that the combination of successive acid and basic treatments imparts the most desired characteristics to the treated fabric. Functionally, the nonwoven fabric, having been treated with both acid and base, is significantly better at absorbing water than (a) the untreated fabric, (b) the fabric treated only with acid, and (c) the fabric treated only with base. Structurally, the treated fabric contains a plurality of fully split conjugate yarns, having individualized polyester components and degraded individualized polyamide components, and a plurality of polyamide “skeletons.” The term “polyamide skeletons” is intended to describe a structure comprised of polyamide components that are joined to one another. In some yarn configurations, when treated, these polyamide skeletons tend to fold over onto themselves.
[0041] [0041]FIG. 4 is a photograph of a cross-section of nonwoven fabric that has been subjected to a 0.25% owb acid solution and a 0.050% owb basic solution. The photograph shows a plurality of individual polyester wedges, some of which are slightly squared off on the sides that were arc-shaped. Slightly to the left of the center of the photograph, a polyamide cluster is visible. Some parts of the polyamide skeleton appear to be degraded, not having the full width and shape of their original form. The polyamide skeletons experience reconfiguration due to the present process. Reconfiguration may be interpreted to mean (a) separation of the skeleton into at least two parts; (b) separation of the skeleton into at least two parts, in which at least one part has been dissolved; and (c) removal of at least a portion of the skeleton, particularly in which removal is at least partially due to dissolution.
[0042] [0042]FIG. 5 is a photograph of a cross-section of nonwoven fabric that has been subjected to a 2.0% owb acid solution and a 0.050% owb basic solution. The photograph shows a plurality of polyester wedges and only a small polyamide cluster in the central area of the photograph. As compared with that of FIG. 4, the fabric of FIG. 5 has much less polyamide remaining. The polyamide components have been removed by the higher concentration of acid. For example, in a fabric having a 65-35% polyester-polyamide composition, removal levels of polyamide vary upwards from 50%. For best results, in terms of water absorption, at least 75% of the polyamide should be removed.
[0043] After treating with acid and base, the nonwoven fabric may be dyed using conventional dyeing techniques. Other finishing chemicals may be added, for example, to improve the hand or soil release characteristics of the fabric.
[0044] The process steps will now be discussed in more detail. In a preferred embodiment, the acid treatment step is conducted in a jet-dyeing machine, into which the fabric is fed, along with an acid solution containing about 2.0% PTSA (based on the weight of the bath). The temperature of the bath is raised to approximately 130° C. and held for an exposure time of about 90 minutes. It is believed that temperatures as high as 150° C. would also be acceptable. After the necessary time, the fabric is cooled, preferably to at least 60° C.. It is then rinsed, preferably twice, with water to prevent reaction between the acid and the base, which will be used in the next step.
[0045] The fabric, having been treated with acid, may then be treated with base. The fabric is fed into a jet-dyeing machine along with a basic solution containing about 0.050% sodium hydroxide (based on the weight on the bath). The temperature of the bath is raised to approximately 130° C. After an exposure time of about 30 minutes, the fabric is then cooled to about 50° C. and rinsed, preferably twice, with water.
[0046] Other finishing chemicals can be applied to the treated fabric, including soil release agents, wetting agents, and hand-building agents. One particularly preferred additive is a high molecular weight ethoxylated polyester, sold under the trade name Lubril QCX, by Rhone Poulenc, which improves both the hand and the soil release characteristics of the fabric. Such chemicals are effectively applied in a padding operation, although other application techniques may be employed. By way of example only, a 3% concentration of Lubril QCX was found to improve the hand and soil release characteristics of the fabric, without negatively impacting the fabric's ability to absorb water.
[0047] The phrase “absorption capacity” is intended to describe the capacity of the fabric to absorb water. The capacity is measured as milliliters of water per gram of fabric. The untreated nonwoven fabric described herein has an absorption capacity of about 3.5 ml/g. The nonwoven fabric of the present product, having been subjected to acidic and basic treatments, has an absorption capacity of about 7.0 ml/g, an improvement of about 200%. The nonwoven fabric of the present product, having been subjected to high pressure hydroentanglement, acidic treatment, and basic treatment, has an absorption capacity of about 6.2 ml/g.
[0048] TABLE 1 shows the results of several trials, conducted according to the process steps described herein.
TABLE 1 Absorption Capacity Testing with Various Treatments Acid Acid Exposure Base Absorption % Concentration Time Concentration Capacity Improvement Treatment (% owb) (minutes) (% owb) (ml/g) (vs. untreated) None 0 0 0 3.52 n/a Dyed 0 0 0 3.82 109 NaOH only 0 0 0.050 4.38 124 PTSA/NaOH 0.25 30 0.050 4.30 122 PTSA/NaOH 0.50 30 0.050 4.43 126 PTSA/NaOH 1.0 60 0.050 4.58 130 PTSA/NaOH 1.0 90 0.050 5.07 144 PTSA/NaOH 2.0 30 0.050 4.82 137 PTSA/NaOH 2.0 60 0.050 5.11 145 PTSA/NaOH 2.0 90 0.050 6.31 179 PTSA/NaOH 2.5 90 0.050 6.76 192 PTSA/NaOH 2.5 120 0.050 7.04 200 PTSA/NaOH 3.0 120 0.050 6.71 191
[0049] The absorbent fabric described herein can be utilized for a variety of purposes. By way of example only, the absorbent fabric may be used as a drying cloth, as a wiping cloth, as part of a filtration system, or as any other product in which the fabric's absorbent characteristics may be beneficial.
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In a preferred embodiment, the present process involves subjecting a fabric having splittable conjugate yarns both to an acidic treatment and to a basic treatment, each of which erodes a portion of the components of the conjugate yarns. The acid treatment, given certain reaction kinetics, removes a portion of the polyamide element of the conjugate filament. The basic treatment has a similar effect on the polyester element of the conjugate filament, making it more hydrophilic. The at least partial removal of the polyamide component, coupled with the increased hydrophilicity of the polyester component, results in a fabric having enhanced absorptive properties. In an alternate embodiment, treatments with only acid or only basic solution may be employed.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to semiconductor memory devices and, more particularly to priority resolvers, match detection and finding the longest match in a group of content addressable memory (CAM) device.
BACKGROUND OF THE INVENTION
[0002] An essential semiconductor device is semiconductor memory, such as a random access memory (RAM) device. A RAM allows a memory circuit to execute both read and write operations on its memory cells. Typical examples of RAM devices include dynamic random access memory (DRAM) and static random access memory (SRAM).
[0003] Another form of memory is the content addressable memory (CAM) device. A conventional CAM is viewed as a static storage device constructed of modified RAM cells. A CAM is a memory device that accelerates any application requiring fast searches of a database, list, or pattern, such as in database machines, image or voice recognition, or computer and communication networks. CAMs provide benefits over other memory search algorithms by simultaneously comparing the desired information (i.e., data in the comparand register) against the entire list of pre-stored entries. As a result of their unique searching algorithm, CAM devices are frequently employed in network equipment, particularly routers, gateways and switches, computer systems and other devices that require rapid content searching, such as routing tables for data networks or matching URLs. Some of these tables are “learned” from the data passing through the network. Other tables, however, are fixed tables that are loaded into the CAM by a system controller. These fixed tables reside in the CAM for a relatively long period of time. A word in a CAM is typically very large and can be 96 bits or more.
[0004] In order to perform a memory search in the above-identified manner, CAMs are organized differently than other memory devices (e.g., DRAM and SRAM). For example, data is stored in a RAM in a particular location, called an address. During a memory access, the user supplies an address and reads into or gets back the data at the specified address.
[0005] In a CAM, however, data is stored in locations in a somewhat random fashion. The locations can be selected by an address bus, or the data can be written into the first empty memory location. Every location has one or a pair of status bits that keep track of whether the location is storing valid information in it or is empty and available for writing.
[0006] Once information is stored in a memory location, it is found by comparing every bit in memory with data in the comparand register. When the contents stored in the CAM memory location does not match the data in the comparand register, the local match detection circuit returns a no match indication. When the contents stored in the CAM memory location matches the data in the comparand register, the local match detection circuit returns a match indication. If one or more local match detect circuits return a match indication, the CAM device returns a “match” indication. Otherwise, the CAM device returns a “no-match” indication. In addition, the CAM may return the identification of the address location in which the desired data is stored or one of such addresses, if more than one address contained matching data. Thus, with a CAM, the user supplies the data and gets back the address if there is a match found in memory.
[0007] Conventional CAMs use priority encoders to translate the physical location of a searched pattern that is located to a number/address identifying that pattern. Typically, priority encoders are designed as a major block common to the whole device. Such a design requires conductors from virtually every word in the CAM to be connected to the priority encoder. Typically, a priority encoder consists of two logical blocks—a highest priority indicator and an address encoder.
[0008] A priority encoder is a device with a plurality of inputs, wherein each of the inputs has an assigned priority. When an input is received on a high priority line in a highest priority indicator, all of the inputs of a lesser priority are disabled, forcing their associated outputs to remain inactive. If any numbers of inputs are simultaneously active, the highest priority indicator will activate only the output associated with the highest priority active input, leaving all other outputs inactive. Even if several inputs are simultaneously active, the priority encoder will indicate only the activity of the input with the highest priority. The priority address encoder is used in the CAM as the means to translate the position (within the CAM) of a matching word into a numerical address representing that location. The priority address encoder is also used to translate the location of only one word and ignore all other simultaneously matching words. However, often times, there is a need to resolve the priority among multiple inputs, each having a different assigned priority.
[0009] Furthermore, there is a need to effectively resolve “imperfect” matches, that is, stored CAM words that may match only a certain number of bits of the data in the comparand, but does not match every bit. Such CAM words are referred to as having a “longest match” condition. In prior art CAMs, search results typically require an exact match (i.e., 100% of the bits) before a system can process those results. Under one method, if an exact match is not found between the stored word and the full comparand, then selected bits in the comparand are masked and the search operation is repeated in an attempt to find a shorter match. If one bit of the comparand is masked at a time, then finding the longest match will require many repeated and undesirable operations/searches. Furthermore, as more bits become masked, multiple matches are indicated for any search result. Without a way to resolve multiple matches, users are typically left to examine the matches manually to find specific properties making one match more desirable than another.
[0010] In an alternative method, data in the CAM is stored in an ordered fashion, wherein data of a certain kind or location is assigned a higher priority, while data of another kind or location is given a lower priority. The priority can be established through assigned priority codes provided by a user. Like the first method described above, the alternative method also requires an exact match. Without an exact match, multiple search attempts are required, wherein, on each attempt, selected bits are masked so that they will not be involved in the matching process. As a result, several matches may be indicated for any search.
[0011] The alternative method is most often found in network communications, where routing tables are used to determine how a message is routed. Messages communicated through the network typically carry data pointing to the desired final destination, as well as topological data that informs the network of how the message is to be routed. Most network systems are configured in a way that only the last router, in a chain of routers in a network, will have the complete routing information and paths. All of the other routers in the path have information on only neighboring routers in a path. Accordingly, when a search is conducted on any router (other than the last router), the routing tables will not have the complete routing information, and will form matches between the searched routing information and the masked data available in the routing table.
[0012] Similar to the first method, a disadvantage of the alternative method is that multiple matching attempts have to be made before a usable match can be found. Secondly, the process of masking bits typically produces multiple matches, where users are left to re-examine each of the matches manually to prioritize the search results. Finally, CAM searches in network communication do not always require an exact match in order for the search to be useful. Often times, an imperfect match result contains sufficient network and “nearest router” data to be used to route the message. However, conventional network systems have not been able to process this data effectively to make use of a “longest match” condition. Accordingly, a system and method is thus needed to determine a “longest match” in a group of CAM words and assign a priority value to each of the longest matches in a single operation.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention provides a CAM match detection circuit and method that detects and resolves multiple CAM words having “longest match” conditions. An embodiment of the invention identifies at least one CAM word that has the largest number of bits matching a search parameter. A priority resolver is disclosed that establishes “longest match” detection on a group of CAM words. A decoder circuit is further disclosed, which assists the system in the present invention to resolve CAM priorities.
[0014] In the present invention data in the CAM does not have to be stored in a specific order in the CAM in order to enable the search for a longest match. Instead a lateral priority code is attached to every entry in the CAM, identifying the level of completeness of the data in that word. CAM words with complete data are assigned the highest lateral priority, and the level of the assigned lateral priority descends as the data in a word has fewer matching bits.
[0015] In a search for a word in the CAM with the most complete data, also known as the search for the longest match, certain bits in the comparand register are masked such that those bits are not involved in the matching process. In the ensuing search, several words in the CAM can match the unmasked data in the comparand register. In the word selection process, the lateral priority of only the matching words (i.e., where each unmasked bit of the comparand matches each corresponding bit of the CAM word) are resolved. Matching CAM words with the highest lateral priority are selected to the second stage of the process wherein a single word is selected, and its address provided at the output of the CAM.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and other features and advantages of the invention will be more readily understood from the following detailed description of the invention which is provided in connection with the accompanying drawings.
[0017] FIG. 1 illustrates a priority match detection circuit according to an embodiment of the invention;
[0018] FIG. 2 illustrates a bit-for-bit match detection circuit for a CAM word;
[0019] FIG. 3 illustrates a priority setting circuit used in the priority match detection circuit of FIG. 1 ;
[0020] FIG. 4 illustrates a priority selection circuit used in the priority match detection circuit of FIG. 1 ;
[0021] FIG. 5 illustrates an address decoder as used in the FIG. 3 priority setting circuit;
[0022] FIG. 6 illustrates a highest priority pointer as used in the FIG. 4 priority selection circuit;
[0023] FIG. 7 depicts a simplified block diagram of a router employing the FIG. 1 priority match detection circuit in accordance with another exemplary embodiment of the invention; and
[0024] FIG. 8 depicts a block diagram of a processor system employing the FIG. 1 priority match detection circuit, in accordance with yet another exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to make and use the invention, and it is to be understood that structural, logical or procedural changes may be made to the specific embodiments disclosed without departing from the spirit and scope of the present invention.
[0026] FIG. 1 illustrates an embodiment showing a priority match detection circuit, which detects “longest match” conditions on every pattern stored in the space of a CAM, and further assigns a priority to each of the “longest match” CAM words having the largest amount of matching bits. Generally, CAM words having the largest amount of matching bits are assigned the highest priority and vice versa. The comparand register 303 shown in FIG. 1 is loaded with search data. The bits in the comparand register 303 are transmitted in parallel to the “bit for bit” match detectors 404 - 407 that accompany each CAM word 400 - 403 . The results of the match detection are forwarded to a respective priority setting circuit 700 , which also includes a respective priority code circuit ( 201 - 204 ). The results of the priority setting circuit 700 are then forwarded to priority encoder 900 for ultimately selecting one CAM word with the highest lateral priority.
[0027] FIG. 2 discloses in further detail the “bit for bit” match detector (e.g., 404 ) for each CAM word (e.g., 400 ). Bit lines from the comparand register (BIT LINE B 0 -BIT LINE Bm) connect through each CAM word in parallel and are outputted 340 at the same bit line location at each CAM word. The bit lines are also connected to one input of an AND gate 353 - 358 in the match detector 404 . Flip flops 350 - 352 are used as a memory device for each bit in the CAM word 312 , wherein each output (Q) and complement (QN) is connected to a respective second input of the AND gates ( 353 - 358 ) as shown in FIG. 2 . Each two AND gates associated with one bit ( 353 - 354 , 355 - 356 & 357 - 358 ) are then connected to the inputs of a respective OR gate ( 359 - 361 ). The output of each OR gate 359 - 361 is then connected to an input terminal of an NOR gate 663 . This gate combination is used to compare the data stored in the CAM word 312 with the corresponding data stored in the comparand register 303 . As will be described below, each time a match is detected between a bit in the CAM word 400 and a corresponding bit in the comparand 303 (e.g., each time any of the outputs on OR gates 359 - 361 are logic “0”) then NOR gate 663 outputs a MATCH signal to a priority setting circuit 700 (of FIG. 3 ), described below.
[0028] The logic function generated by each group of gates 353 - 361 is an exclusive OR (EXOR) function [(Bm*QNm)+(BNm*Qm)]. Whenever there is a mismatch, the Q output of a CAM word flip-flop will be the same as the respectively compared bit BNm from the comparand register 303 , providing a logic “1” output on the respective OR gate ( 359 - 361 ). Conversely, if there is a match, then the output on the respective OR gate ( 359 - 361 ) will be a logic “0.” If the outputs from all the OR gates 359 - 361 are “0,” then there is a match between all of the unmasked bits in the comparand register 303 and the corresponding bits in the CAM word (e.g., 400 ). In any case, as the bits in the CAM word 400 are compared one by one with the bits in the comparand 303 , for every match detected, a MATCH signal is sent by NOR gate 663 to the priority setting circuit 700 of FIG. 3 .
[0029] FIG. 3 illustrates a priority setting circuit 700 used in the priority match detection circuit 399 of FIG. 1 . A separate priority setting circuit 700 is associated with each CAM word ( 400 - 403 ), wherein a priority code 201 associated with a CAM word, is connected to current decoder 100 and address decoder 378 . Priority code 201 is comprised of a set of flip-flops 660 - 662 , each of which are programmed with a bit of the priority code assigned to each respective CAM word. The priority code may be preset by the user for each CAM word (e.g., depending upon the type of data being stored by the CAM word). Whenever a logic “high” MATCH signal is received from an associated CAM word, it is inputted to and activates transistor 130 . This, in turn, activates decoder circuit 100 . The logic “high” MATCH signal is also forwarded to a first terminal of each of AND gates 368 - 375 .
[0030] The exemplary decoder 100 depicted in FIG. 3 is a 3×8 current-based decoder, where a priority input code comprising 3 bits (D 0 -D 2 ) and their respective complements (DN 0 -DN 2 ) is entered into the decoder 100 , generating an 8-bit priority code output (P 0 -P 7 ). When activated, each priority code output line (P 0 -P 7 ) may pass a current to ground via transistor 130 . As will be described more fully below, the presence of such a current dictates which priority code output (P 0 -P 7 ) is activated. It is understood that, while a 3×8 decoder is used in this exemplary embodiment, that any size decoder may be used having n inputs, with associated m complement inputs, and 2′ outputs.
[0031] The input line D 0 (i.e., the LSB for the priority code for the CAM word) of decoder 100 is connected to the gate terminal of n-type transistors 105 - 108 . The drain terminals of transistors 105 - 108 are connected to the output lines P 7 , P 5 , P 3 and P 1 respectively. Similarly, complement input line DN 0 is connected to a respective gate terminal of n-type transistors 101 - 104 . The drain terminal of transistors 101 - 104 are connected to output lines P 6 , P 4 , P 2 and P 0 respectively. Thus, if input D 0 is logic “high,” input DN 0 will be logic “low.” Accordingly, a voltage will be transmitted to the gates of transistors 105 - 108 , while no voltage flows to the gates of transistors 101 - 104 .
[0032] Input lines D 1 and DN 1 are connected to the gate terminals of n-type transistors 111 - 112 and 109 - 110 , respectively, and input lines D 2 and DN 2 are connected to the gate terminals of n-type transistors 113 and 114 , respectively. Each input line that transmits logic “high,” will turn on the transistors having a gate terminal connected to that line, while input lines transmitting a logic “low” will turn off the transistors having a gate terminal connected to the line.
[0033] The transistors connected in series in the decoder 100 can be thought of as performing a logic AND function, while transistors connected in parallel perform a logical OR function. Thus, transistor 113 performs a logical AND function with transistors 111 and 109 , wherein transistors 111 and 109 are performing a logic OR respective to each other. In turn, transistor 111 performs a respective logical AND with transistors 105 and 101 , which perform a logical OR respective to each other, and so on.
[0034] Still referring to FIG. 3 , as a first example, if an input “ 001 ” (D 2 =0, D 1 =0, D 0 =1) is transmitted to decoder circuit 100 , the complement “ 110 ” (DN 2 =1, DN 1 =1, DN 0 =0) will also be transmitted from mismatch counter 320 . Since lines D 0 , DN 1 , and DN 2 are logic high (i.e., “1”), transistors 105 - 108 , 109 - 110 , and 114 will be turned on. Since the three series-connected transistors 114 , 110 , and 108 are conducting, output line P 1 will be coupled to ground and a current will flow along the line connecting P 1 and transistors 114 , 110 and 108 .
[0035] As a second example, if an input “ 110 ” (D 2 =1, D 1 =1, D 0 =0) is transmitted to the decoder circuit 100 , the complement “ 001 ” (DN 2 =0, DN 1 =0, DN 0 =1) will be transmitted along with the original input. Since lines DN 0 , D 1 and D 2 are logic high (i.e., “1”), transistors 101 - 104 , 111 - 112 and 113 will be turned on. Since the only current path open is the path along transistors 113 , 111 and 101 (the only active transistors in the pathway to ground), output line P 6 will be coupled to ground and a current will flow along the line connecting P 6 and transistors 113 , 111 , and 101 . As will be described in greater detail below in connection with FIG. 4 , each of the priority code positions P 0 -P 7 are sensed to determine which one or ones are carrying current.
[0036] Each time the MATCH signal is activated, current will flow through one of the priority code output lines (P 0 -P 7 ) of decoder 100 . In this manner, a priority code value is established for the CAM word depending on the longest match detected. Generally, the longer the match, the greater the priority and vice versa.
[0037] Turning to FIG. 4 , a priority selection circuit 701 is disclosed, wherein each corresponding priority output line (P 0 -P 7 ) from each priority setting circuit 700 is coupled together to a respective resistor in resistor bank 383 . Since the priority output lines are connected in parallel, current flowing through any of the priority output code lines (P 0 -P 7 ) causes a voltage drop across a respective resistor 383 . There can be a voltage drop across one resistor or any number of resistors simultaneously. Each resistor 383 is further connected to respective sense amplifiers 384 A-H to sense the respective quantities of current flowing through the priority code lines P 0 -P 7 , with P 0 being configured to have the highest priority, and inputs P 1 -Pn having a progressively lower priority. The outputs of the sense amplifiers 384 A-H are in turn connected to a highest priority pointer circuit 450 .
[0038] Highest priority pointer 450 points to the CAM word(s) from the group being tested having the highest lateral priority. The highest priority pointer 450 points back to the CAM word having the highest lateral priority. The logic configuration in the highest priority pointer 450 is set so that, no matter how many inputs are simultaneously active, the pointer will only output one line (R 0 -R 7 ) as the active line (logic “1”).
[0039] Looking together at FIGS. 3 and 4 , the output of the highest priority pointer 450 (R 0 -R 7 ) is fed back to each priority setting circuit 700 of each CAM word ( 400 - 403 ). Each output of the pointer 450 is inputted (R 0 -R 7 ) into a respective AND gate 368 - 375 as shown in FIG. 3 . The outputs of priority code circuit 201 in FIG. 3 are also connected to address decoder 378 that enables only one AND gate 368 - 375 to be active. Accordingly, the combination of the priority code (D 0 -D 2 ), as decoded by the address decoder 378 and the fed-back output (R 0 -R 7 ) of the highest priority pointer 450 selects one gate for output to gate 376 and output (G n ). Respective outputs G 0 -G n from each CAM word are then inputted to a priority encoder 900 which establishes the address of the CAM word with the longest match.
[0040] Turning now to FIG. 5 , the address decoder 378 (of FIG. 3 ) is described in greater detail. Inputs D 0 -D 2 and complement signals DN 0 -DN 2 are input into logic AND gates 600 - 607 , wherein AND gates 600 - 607 respectively output signals S 0 -S 7 which are then transmitted to a respective input on NAND gates 368 - 375 shown in FIG. 3 , whose outputs are collectively NORed at gate 376 . NOR gate 376 generates a priority signal G n . The outputs S 0 -S 7 are determined by the following logical functions:
S0 = DN0 * DN1 *DN2 S1 = D0 * DN1 * DN2 S2 = DN0 * D1 * DN2 S3 = D0 * D1 * DN2 S4 = DN0 * DN1 * D2 S5 = D0 * DN1 * D2 S6 = DN0 * D1 * D2 S7 = D0 * D1 * D2
[0041] Turning to FIG. 6 , a portion of the highest priority pointer 450 (of FIG. 4 ) is described in greater detail. Each input line shown (only P 0 -P 3 are shown for simplicity) is connected to an input terminal of NOR gates 618 - 621 and NAND gates 610 - 613 . The output of each NAND gate 611 - 613 is shown as being inputted into a second terminal of NOR gates 618 - 620 , respectively. The output of each NAND gate 611 - 613 is further inverted by inverters 614 - 616 and transmitted to adjacent NAND gates 610 - 613 .
[0042] FIG. 7 is a simplified block diagram of a router 1100 as may be used in a communications network, such as, e.g., part of the Internet backbone. The router 1100 contains a plurality of input lines and a plurality of output lines. When data is transmitted from one location to another, it is sent in a form known as a packet. Oftentimes, prior to the packet reaching its final destination, that packet is first received by a router, or some other device. The router 1100 then decodes that part of the data identifying the ultimate destination and decides which output line and what forwarding instructions are required for the packet.
[0043] Generally, CAMs are very useful in router applications because historical routing information for packets received from a particular source and going to a particular destination is stored in the CAM of the router. As a result, when a packet is received by the router 1100 , the router already has the forwarding information stored within its CAM. Therefore, only that portion of the packet that identifies the sender and recipient need be decoded in order to perform a search of the CAM to identify which output line and instructions are required to pass the packet onto a next node of its journey.
[0044] Still referring to FIG. 7 , router 1100 contains the added benefit of employing a semiconductor memory chip containing a priority match detection circuit, such as that described in connection with FIGS. 1-6 . Therefore, the CAM has the benefit of providing “longest match” detection and expanded pattern recognition, in accordance with an exemplary embodiment of the invention.
[0045] FIG. 8 illustrates an exemplary processing system 1200 —which utilizes a CAM priority match detection circuit such as that described in connection with FIGS. 1-6 . The processing system 1200 includes one or more processors 1201 coupled to a local bus 1204 . A memory controller 1202 and a primary bus bridge 1203 are also coupled the local bus 1204 . The processing system 1200 may include multiple memory controllers 1202 and/or multiple primary bus bridges 1203 . The memory controller 1202 and the primary bus bridge 1203 may be integrated as a single device 1206 .
[0046] The memory controller 1202 is also coupled to one or more memory buses 1207 . Each memory bus accepts memory components 1208 . Any one of memory components 1208 may contain a CAM array performing priority match detection as described in connection with FIGS. 1-6 .
[0047] The memory components 1208 may be a memory card or a memory module. The memory components 1208 may include one or more additional devices 1209 . For example, in a SIMM or DIMM, the additional device 1209 might be a configuration memory, such as a serial presence detect (SPD) memory. The memory controller 1202 may also be coupled to a cache memory 1205 . The cache memory 1205 may be the only cache memory in the processing system. Alternatively, other devices, for example, processors 1201 may also include cache memories, which may form a cache hierarchy with cache memory 1205 . If the processing system 1200 include peripherals or controllers which are bus masters or which support direct memory access (DMA), the memory controller 1202 may implement a cache coherency protocol. If the memory controller 1202 is coupled to a plurality of memory buses 1207 , each memory bus 1207 may be operated in parallel, or different address ranges may be mapped to different memory buses 1207 .
[0048] The primary bus bridge 1203 is coupled to at least one peripheral bus 1210 . Various devices, such as peripherals or additional bus bridges may be coupled to the peripheral bus 1210 . These devices may include a storage controller 1211 , a miscellaneous I/O device 1214 , a secondary bus bridge 1215 , a multimedia processor 1218 , and a legacy device interface 1220 . The primary bus bridge 1203 may also be coupled to one or more special purpose high speed ports 1222 . In a personal computer, for example, the special purpose port might be the Accelerated Graphics Port (AGP), used to couple a high performance video card to the processing system 1200 .
[0049] The storage controller 1211 couples one or more storage devices 1213 , via a storage bus 1212 , to the peripheral bus 1210 . For example, the storage controller 1211 may be a SCSI controller and storage devices 1213 may be SCSI discs. The I/O device 1214 may be any sort of peripheral. For example, the I/O device 1214 may be an local area network interface, such as an Ethernet card. The secondary bus bridge may be used to interface additional devices via another bus to the processing system. For example, the secondary bus bridge may be an universal serial port (USB) controller used to couple USB devices 1217 via to the processing system 1200 . The multimedia processor 1218 may be a sound card, a video capture card, or any other type of media interface, which may also be coupled to one additional device such as speakers 1219 . The legacy device interface 1220 is used to couple legacy devices, for example, older styled keyboards and mice, to the processing system 1200 .
[0050] The processing system 1200 illustrated in FIG. 8 is only an exemplary processing system with which the invention may be used. While FIG. 8 illustrates a processing architecture especially suitable for a general purpose computer, such as a personal computer or a workstation, it should be recognized that well known modifications can be made to configure the processing system 1200 to become more suitable for use in a variety of applications. For example, many electronic devices which require processing may be implemented using a simpler architecture which relies on a CPU 1201 coupled to memory components 1208 and/or memory devices 1209 . The modifications may include, for example, elimination of unnecessary components, addition of specialized devices or circuits, and/or integration of a plurality of devices.
[0051] While the invention has been described in detail in connection with preferred embodiments known at the time, it should be readily understood that the invention is not limited to the disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. For example, although the invention has been described in connection with specific circuits employing different configurations of p-type and n-type transistors, the invention may be practiced with many other configurations without departing from the spirit and scope of the invention. In addition, although the invention is described in connection with flip-flop memory cells, it should be readily apparent that the invention may be practiced with any type of memory cell. It is also understood that the logic structures described in the embodiments above can substituted with equivalent logic structures to perform the disclosed methods and processes. Accordingly, the invention is not limited by the foregoing description or drawings, but is only limited by the scope of the appended claims.
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An apparatus and method is disclosed for a CAM priority match detection circuit that identifies one or more CAM words from a group of CAM words having a “longest match” that matches the bits in a corresponding comparand register. A decoder is further disclosed, wherein the decoder uses n input lines and m complement lines to generate 2 n outputs, wherein only one of the outputs will be active. A priority setting circuit and a priority resolving circuit are also disclosed, wherein the priority setting circuit resolves an initial matching operation to supply priority values to CAM words, and the priority resolving circuit processes the priority values to determine an overall priority for a group of CAM words.
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FIELD OF THE INVENTION
The present invention relates to a device for manipulating healds or drop wires (designated below as harness members) in a warp-thread drawing-in machine from their separation from a stack via the drawing-in of the warp threads up to the transfer to supporting members provided for being arranged in a weaving machine.
BACKGROUND
Devices of this type known hitherto, as are used, for example, in the warp-thread drawing-in machine USTER DELTA of Zellweger Uster AG, comprise a multiplicity of various elements which in each case always perform only a limited partial function within the sequence. With regard to the manipulation of the drop wires, this means, for example, that these drop wires after their separation, are transported by first members to the drawing-in position, are gripped there by second members and turned for the orientation for the drawing-in of the warp threads and are then transported further by third members, the various members only being partly connected frictionally to the drop wires.
Apart from the fact that the plurality of various members makes the device more expensive, the interfaces in particular between the various members inside the device represent potential sources of error. This especially applies when there is a frictional connection between the members and the drop wires.
SUMMARY OF THE SUBJECT MATTER OF PRESENT INVENTION
An object of invention, then, is to provide a device of the type mentioned at the beginning in which the potential sources of error are minimised and the costs are kept as low as possible.
This object is achieved according to the invention by holding means for accepting the separated harness members and for positively transporting them to a drawing-in station and a transfer station, by positioning means arranged in the area of the drawing-in station, and by transfer means, arranged in the area of the transfer station, for transferring the harness members having a drawn-in warp thread to the supporting members.
The device, according to the invention therefore requires only a single type of manipulating means for manipulating the healds or drop wires from the point where they are separated from a stack up to the point where they are transferred to their supporting members. Due to the elimination of a multiplicity of potential sources of error and causes of trouble, the device is substantially less susceptible to trouble in operation. For integrating into the drawing-in process, the device requires merely two interfaces: one leading to the separating station and one at the transfer station leading to the supporting members. The susceptibility to trouble is also substantially reduced and in addition the possibility of a modular construction of the drawing-in machine presents itself.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail below with reference to an exemplary embodiment and the drawings, in which:
FIG. 1 shows a perspective overall representation of a drawing-in machine according to the invention,
FIG. 2 shows a perspective representation of the drawing-in module of the drawing-in machine in FIG. 1,
FIG. 3 shows a plan view of a device according to the invention for manipulating healds in the direction of arrow 3 in FIG. 2,
FIG. 4 shows a view in the direction of arrow 4 in FIG. 3,
FIG. 5 shows a detail of FIG. 4 to an enlarged scale,
FIG. 6 shows a view in the direction of arrow 6 in FIG. 5,
FIG. 7 hows a plan view of a device according to the invention for manipulating drop wires; and
FIG. 8 shows a view in the direction of arrow 8 in FIG. 7.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to FIG. 1, the drawing-in machine consists of a mounting stand 1 and various subassemblies arranged in this mounting stand 1, each of which sub-assemblies represents a functional module. A warp-beam truck 2 with a warp beam 3 arranged thereon can be recognized in front of the mounting stand 1. In addition, the warp-beam truck 2 contains a so-called lifting device 4 for holding a frame 5, on which the warp threads KF are clamped. This clamping is effected before the actual drawing-in and at a location separate from the drawing-in machine. The frame 5 is positioned at the bottom end of the lifting device 4 directly next to the warp beam 3. For the drawing-in, the warp-beam truck 2, together with warp beam 3 and lifting device 4, are moved to the so-called setting-up side of the drawing-in machine and the frame 5 is lifted upwards by the lifting device 4 to then assume the position shown.
The frame 5 and the warp beam 3 are displaced in the longitudinal direction of the mounting stand 1. During this displacement, the warp threads KF are directed past a thread-separating unit 6 and as a result are separated and selected. After the selection, the warp threads KF are cut off and presented to a drawing-in needle 7, which forms a component of the so-called drawing-in module. The selecting device used in the warp tying machine USTER TOPMATIC of Zellweger Uster AG can be used, for example, for the selection of the warp threads.
Next to the drawing-in needle 7 can be recognized a video display unit 8, which belongs to an operating station and serves to display machine functions and machine malfunctions and to input data. The operating station, which forms part of a so-called programming module, also contains an input stage for the manual input of certain functions, such as, for example, creep motion, start-stop, repetition of operations, and the like. The drawing-in machine is controlled by a control module which contains a control computer and is arranged in a control box 9. Apart from the control computer, this control box contains a module computer for every so-called main module, the individual module computers being controlled and monitored by the control computer. The main modules of the drawing-in machine, apart from the modules already mentioned--drawing-in module, yarn module, control module and programming module, are the heald, drop-wire, and reed modules.
The thread-separating unit 6, which presents the warp threads KF to be drawn in to the drawing-in needle 7, and the path of movement of the drawing-in needle 7, which runs vertically to the plane of the clamped warp threads KF, define a plane in the area of a support 10 forming part of the mounting stand 1, which plane separates the setting-up side already mentioned from the so-called taking-down side of the drawing-in machine. The warp threads and the individual elements into which the warp threads are to be drawn in are fed at the setting-up side, and the so-called harness (healds, drop wires and reed) together with the drawn-in warp threads can be removed at the taking-down side. During the drawing-in, the frame 5 having the warp threads KF and the warp-beam truck 2 having the warp beam 3 are moved to the right past the thread-separating unit 6, in the course of which the drawing-in needle 7 successively removes from the frame 5 the warp threads KF clamped on the latter.
When all warp threads KF are drawn in and the frame 5 is empty, the latter, together with the warp-beam truck 2, the warp beam 3 and the lifting device 4, is located on the taking-down side.
Arranged directly behind the plane of the warp threads KF are the warp-stop-motion drop wires LA, behind the latter the healds LI and further to the rear the reed. The drop wires LA are stacked in hand magazines and the full hand magazines are hung in sloping feed rails 11, on which they are transported to the right towards the drawing-in needle 7. At this location they are separated and moved into the drawing-in position. Once drawing-in is complete, the drop wires LA pass on drop-wire supporting rails 12 to the taking-down side.
The healds LI are lined up on rails 13 and shifted automatically on the latter to a separating stage. The healds LI are then moved individually into their drawing-in position and, once drawing-in is complete, are distributed over the corresponding heald shafts 14 on the taking-down side. The reed is likewise moved step-by-step past the drawing-in needle 7, the corresponding reed gap being opened for the drawing-in. After the drawing-in, the reed is likewise located on the taking-down side. A part of the reed WB can be recognized to the right next to the heald shafts 14. This representation is to be understood purely as an illustration, since the reed, at the position shown of the frame 5, is of course located on the setting-up side.
As further apparent from the figure, a so-called harness truck 15 is provided on the taking-down side. This harness truck 15, together with the drop-wire supporting rails 12, fixed thereon, heald shafts 14 and holder for the reed, is pushed into the mounting stand 1 into the position shown and, after the drawing-in, carries the harness having the drawn-in warp threads KF. At this moment, the warp-beam truck 2 together with the warp beam 3 is located directly in front of the harness truck 15. By means of the lifting device 4, the harness is now reloaded from the harness truck 15 onto the warp-beam truck 2, which then carries the warp beam 3 and the drawn-in harness and can be moved to the relevant weaving machine or into an intermediate store.
The functions described are distributed over a plurality of modules which represent virtually autonomous machines which are controlled by a common control computer. The cross connections between the individual modules run via this higher-level control computer and there are no direct cross connections between the individual modules. The main modules (already mentioned) of the drawing-in machine are themselves also of modular construction and as a rule consist of submodules. This modular construction is described in Swiss Patent Application No. 03 633/89-1, to the disclosure of which reference is herewith expressly made.
As apparent from FIG. 2, the drawing-in needle 7, which forms the main component of the drawing-in module, is formed by a gripper band 16 and a clamping gripper 17 carried by the same. The drawing-in needle 7 is guided in the lifting direction (arrow P) in a channel-like guide 18 which extends from the frame 5 in a rectilinear direction up to a curved end part 19. The guide 18 passes through the drawing-in machine and is in each case interrupted in the area of the harness members (drop wires LA, healds LI) and the reed WB in order to permit the feed of the harness members to the drawing-in position and their further transport after drawing-in is complete up to the transfer (arrow S) to drop-wire supporting rails 12 and to the heald shafts 14 (FIG. 1) or the drawing-in of the warp threads into the reed WB, the so-called reeding. The gripper band 16 is provided with feed holes at a uniform distance apart and is driven by a band wheel BR which can be motor-driven and which has on its periphery lobe-shaped or stud-shaped projections which engaged the feed holes.
The feed of the drop wires LA and the healds LI to the drawing-in position and their further transport up to the transfer to the drop-wire supporting rails or to the heald shafts is effected by a submodule drop-wire distribution LD and by a submodule heald distribution HD. In the transport direction of the healds LI, the heald distribution module HD follows the submodule heald separation, which is described in Swiss Patent Application No. 706/90. In the transport direction of the drop wires LA, the drop-wire distribution module LD follows the submodule drop-wire separation, which is described in Swiss Patent Application 2699/90.
Both submodules HD and LD perform the same functions in principle by accepting healds or drop wires presented to them sequentially, by transporting them to their drawing-in position and by transporting them further after drawing-in of the warp threads is complete to a transfer station, where transfer to the heald shafts or drop-wire supporting rails is effected.
As can be gathered from the abovementioned Swiss Patent Application No. 706/90, the frontmost heald LI, lying directly in front of the submodule HD, of a heald stack is in each case moved by a piston-like selecting member out of the heald stack into an intermediate position and is pushed from this intermediate position by a plunger onto needle-like holding means. The latter form a component of the heald distribution module HD.
According to Swiss Patent Application 2699/90, the drop wires LA are pushed up slightly from their stack by a friction roller so that their head end projects freely upwards. In this position, a hook mounted on a conveyor belt grips the drop wires and pulls them completely out of the stack into a transfer station. In the latter, the suspended drop wire is blown by compressed air onto corresponding holding means which form a component of the drop-wire distribution module LD.
The heald distribution module HD is shown in FIGS. 3 to 6. FIG. 3 shows a plan view to a scale of about 1:2.5, FIG. 4 shows a side view in the direction of arrow 4 in FIG. 3 to a slightly smaller scale, and FIGS. 5 and 6 show a detail to an enlarged scale.
According to the representation, the heald distribution module HD essentially comprises two components: transport planes formed by appropriate plates 20, in each of which planes an endless transport means provided with heald holders is guided. This transport means is designed like a band, belt or chain. A chain is preferably used as the transport means, which chain consists of individual links 22 carried by a toothed belt 21. The toothed belt 21 is provided with a tooth system on either side; the tooth system on the inside meshes with corresponding guide rollers 23, of which at least one is motor-driven. The tooth system on the outside of the toothed belt 21 centres the chain links.
On its side remote from the toothed belt 21, each of the chain links 22 has a projecting V-shaped rib, to whose apex a pin 24 designed to serve as a heald holder is anchored. The end hooks of the healds are slipped onto the pins 24. The positions of the upper and lower belts 21 carrying the chain links 22 are adjustable relative to each other so that the mutual vertical distance between the two sets of pins 24 can be adjusted to accommodate therebetween healds of different lengths. This may be accomplished through adjusting means that includes a threaded spindle GS which meshes with thread locks mounted on the plates 20 of the transport planes.
The healds are transferred to the heald distribution module HD at the locations designated by arrows A, the two arrows symbolising the fact that the separation of the healds and their transfer takes place in two channels, although this is not absolutely necessary. Sensors 25 for monitoring the heald acceptance are present at the acceptance locations. After acceptance, the healds are transported to the thread drawing-in position by the chain 21, 22 rotating anti-clockwise and driven intermittently by a stepping motor.
Provided between the acceptance point A and the thread drawing-in position is a guide rail 26 which prevents the healds from falling off the pins 24. In FIGS. 3 to 6, the thread drawing-in path is designated by a chain-dotted straight line FE; the thread drawing-in position of the healds is the point at which their path intersects the straight line FE.
In this area, the channel-like guide 18 (FIG. 2) has an interruption through which the healds cross the guide 18. Since the thread eyelet of the healds is relatively small, the healds must be positioned very accurately for the drawing-in of the thread. This precise positioning is effected vertically on the one hand, that is, in the longitudinal direction of the healds, and laterally on the other hand, that is, transversely to the longitudinal direction and transversely to the thread drawing-in path FE by corresponding positioning means HP and SP respectively. The vertical-positioning means HP apparent from FIG. 4 comprise an endless cable 28 which is guided via drive rollers 27 and to whose two sides one positioning pin 29 each is fastened. Upon actuation of the vertical-positioning means HP, these positioning pins shift up and down and press against the V-shaped ribs of the two chain links 22 carrying the heald to be positioned. The drive for the cable 28, which drive is formed by a pneumatic cylinder 30, and the top drive rollers 27 are mounted on a supporting arm 31. The supporting arm 31 is carried by a support shaft 32 passing through the heald distribution module HD. A total of two support shafts 32 of this type are provided.
The lateral-positioning means SP apparent in particular from. FIGS. 5 and 6 are mounted in the area of the channel-like guide 18 on a supporting means 33 that is likewise fastened to the support shaft 32 carrying the supporting arm 31. The lateral positioning means SP comprise a cross guide 34 for the healds, a positioning lever 35 and a control stirrup 36. The cross guide 34, which is arranged just below the channel-like guide 18, has a funnel-like entry part and, following the entry part, a relatively narrow guide part in which the healds are guided fairly accurately with regard to their lateral displacement. The exact lateral positioning is effected by the positioning lever 35. This positioning lever 35 is designed as a two-piece gripper. It is driven by a pneumatic cylinder 37 and is moved at an angle from below towards the heald to be positioned. In its end position drawn in broken lines in FIG. 5, the positioning lever 35 is closed by the control stirrup 36 driven by a pneumatic cylinder 38, as a result of which the heald is firmly clamped and positioned for the drawing-in of the thread.
Following the drawing-in of the thread, the heald is released again from the positioning lever 35 so that it can leave the cross guide 34 and finally also the guide rail 26 and can be transferred to its heald supporting rail. This transfer is effected by pneumatically driven ejector cylinders 39 which are arranged in the area of the two plates 21. The cylinders 39 can be selectively activated as a function of the distribution, predetermined by the pattern to be produced on the weaving machine, of the healds over the individual heald shafts. In fact in each case the top and bottom ejector cylinder 39 of each heald can be activated in pairs. According to the representation, twenty-eight top and bottom ejector cylinders 39 each are provided, so that the healds can be distributed over a maximum of twenty-eight shafts.
The drop-wire distribution module LD is shown in FIGS. 7 and 8, and in fact in FIG. 7 is shown in a plan view to a scale of about 1:1.5 and in FIG. 8 is shown in a side view in the direction of arrow 8 in FIG. 7. The function of the drop-wire distribution module LD is very similar to that of the heald distribution module HD. The main differences between the two lie in the fact that the drop wires are shorter than the healds, that their thread eyelet is substantially larger than that of the healds so that the demands made on the positioning accuracy for the drawing-in are no so great, and that the number of drop-wire supporting rails is substantially smaller than that of the heald supporting rails.
Just like the heald distribution module HD, the drop-wire distribution module LD contains as a basis two plates 40 and 41 which are spaced apart at and serve as supporting means for the various transport and positioning means for the drop wires LA. The distance between the two plates 40, 41 can be adjusted. Stretched on the top plate 40 via corresponding gearwheels 42 is an endless toothed belt 43, to the outside or which holding means for the drop wires LA are fastened. These holding means consist of a small plate 45 having two supporting pins 44 arranged vertically one below the other. The drop wires LA are suspended with their supporting slit on the supporting pins 44.
The drop wires are transferred to the holding means 44, 45 at locations designated by arrows B, the two arrows symbolising two processing channels of the drop-wire separation stage. The acceptance of the drop wires by the drop-wire distribution module LD is monitored by sensors (not shown). After acceptance, the drop wires LA are transported by the toothed belt 43, which moves in an anti-clockwise and is driven intermittently by a stepping motor 46. The drop wires LA are transported to the thread drawing-in position, which lies in the area of a star-shaped positioning wheel 47 carried by the bottom plate 41. To prevent the drop wires from falling off the supporting pins 44, a guide rail 48 is provided in the area of the two plates 40, 41. Each guide rail 48 extends between the acceptance location B and a point directly after the thread drawing-in position.
The channel-like guide 18 (FIG. 2) passes through the drop-wire distribution module LD along the chain-dotted straight line FE (FIG. 7), which marks the thread drawing-in path, at a level between the two plates 40 and 41. The thread drawing-in position is located at the point at which this straight line FE passes through the toothed belt 43 at the positioning wheel 47, which point is designated by an x in FIG. 8. The thread eyelet FA of the drop wire LA positioned by the supporting pins 44 and between the projections of the positioning wheel 47 is then in alignment with the straight line FE. In this area, the channel-like guide 18 (FIG. 2) has an interruption in which the drop wires LA cross the guide 18.
The positioning wheel 47 is likewise driven intermittently, and in fact via a toothed belt 49 and a gearwheel 50. The gear wheel 50 is fastened to the drive spindle 52 of the toothed belt 43 which carries the holding means 44, 45 for the drop wires LA. The drive spindle 52 is driven by the stepping motor 46 via a toothed-belt drive 51.
After the drawing-in of the thread in the area of the positioning wheel 47, the drop wires LA, now carrying one drawn-in warp thread each, pass into the area of a bank-like row 53 of transfer stations. As shown in FIG. 7, a total of eight transfer stations provided in accordance with the number of (eight) possible drop-wire supporting rails 12 (FIG. 1) In the transfer stations, the drop wires LA are pushed according to a program onto the corresponding drop-wire supporting rails 12.
According to the representation, the transfer stations consist of a top and a bottom substation 54 and 55, each of which is fastened to the corresponding plate 40 or 41. Both substations 54 and 55 each have a pneumatically driven ejector 56 and 57 respectively, upon actuation of which the relevant drop wire LA is pushed onto its supporting rail 12. The top substation 54 is designed in such a way that when the drop wires are being pushed down from the supporting pins 44, the drop wires LA run with their topmost edge against a guide plane 58 that slopes downwards. Thus, the drop wires LA directed downwards so that they are positively guided onto an entry flank 59 (of corresponding sloping design) of the drop-wire supporting rails 12 and slide along from this entry flank 59 onto the horizontal part of the drop-wire supporting rail 12.
The bottom substation 55 contains a shaft-like chamber 60 which is open to the front, rear and top and is separated from the chamber of the adjacent stations by cross walls 61. Each chamber 60 is closed off from the toothed belt 43 and the ejector 57 by a flap 62 like a double swing door. This flap 62 serves as a safety device to prevent the drop wires LA from falling off the supporting pins 44 unintentionally as a result of the tension force of the drawn-in warp threads. When activated, the ejector 57 pushes open the flap 62 and as a result pushes the drop wire LA at its bottom part into the chamber 60; at the same time, the top ejector 56 pushes the drop wire from its supporting pins 44 towards the guide plane 58 and onto the entry flank 59 of the drop-wire supporting rails 12. The latter are held in the transfer position by distance plates displaceable in the longitudinal direction of the rails; when they are displaced along the drop-wire supporting rails 12, the distance plates transport the drop wires further. The drop-wire supporting rails 12 are held in the horizontal position by retractable and extendable holding bolts fastened to a transport system. In their retracted position, these holding bolts position the drop-wire supporting rails 12; they are extended for passing the drop wires at the relevant location.
At their top plate 21 or 40, both the heald and the drop-wire distribution module HD and LD respectively are provided with corresponding covering hoods which on the one hand cover the entire mechanism and protect the same from being covered in dust and on the other hand have connections for the requisite pneumatic and electronic lines.
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The device serves to manipulate the healds or drop wires from their separation from a stack via the drawing-in of the warp threads up to the transfer to supporting members provided for arranging in a weaving machine and it contains holding devices for accepting the separated healds or drop wires and for positively transporting them to a drawing-in station and a transfer station, positioning elements arranged in the area of the drawing-in station, and transfer devices, arranged in the area of the transfer station, for transferring the healds or drop wires having a drawn-in warp thread to the supporting members.
Consequently, only a single type of manipulating arrangement is required for manipulating the healds and drop wires from their separation up to the transfer to the supporting members. That results in a substantial reduction in potential sources of error and thus in the susceptibility to trouble. In addition, only two interfaces are necessary: one leading to the separating station and one at the transfer station leading to the supporting members.
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FIELD OF THE INVENTION
This invention relates to the building field and to devices that can assist people, with or without handicaps, in gaining ingress and egress from buildings. This invention is directed, particularly, toward adding a mechanical advantage and ease of operation to a person's effort in opening sliding doors.
BACKGROUND OF THE INVENTION
Sliding doors are conventionally used in many applications as both interior and exterior doors. Usually these doors are referred to as pocket doors when mounted inside partitions between rooms. These doors may, indeed, slide on tracks laid on the floor or they may move on rollers in the bottom of the doors or tracks. Sometimes, they are hung from tracks mounted on the wall or ceiling connected to the top of the doors. In all applications, the sliding doors move horizontally parallel to a wall to open or close a door opening in the wall.
One of the more popular uses of the sliding door is in private homes and apartments as a glass exterior door, opening onto a deck or patio. The architectural and styling advantages of such doors are well known. However, either because of considerations of the doors moving in close proximity to each other or the wall or, simply, a sleeker style, the doors usually do not have any substantial handle for operation. In most cases, the doors have indentations that will accommodate the ends of the fingers. A person only has this small purchase to operate the door.
The operation of sliding doors is of no consequence to the young and fit with both hands free. But for those with weakened muscles, bone and joint problems, such as arthritis, such doors present a problem. Also, for everyone who tries to use a sliding door when their hands or arms are otherwise occupied with objects, the lack of a handle proves frustrating.
What is lacking in the prior art is a simple door opener that will operate a sliding door through use of the weight of the body, without the use of the hands, and adds mechanical advantage to the amount of force applied to the opener.
DESCRIPTION OF THE PRIOR ART
There are many foot operated door openers in the prior art however, the devices have not become popular consumer items. Such a situation usually results from the costs of the devices and/or the complexity of installation and reliability of use.
Representative of the prior art is U.S. Pat. No. 5,469,661 to Finkelstein et al, entitled, Sliding Door Foot Treadle. The disclosure is directed to opening refrigerator doors by a foot assist that moves the door in three dimensions. The treadle is an L-shaped lever mounted on the refrigerator by a bolt through the juncture of the legs of the L. One downwardly extending leg is positioned against the edge of the door and the other leg extends horizontally as the treadle. Stepping on the treadle rotates the downwardly extending leg against the edge of the door for opening the door. In this construction, the downwardly extending leg wears against the edge of the door. Further, the treadle leg and the operating leg must bear all the opening load on the unsupported ends of the legs which could lead to failure or bending of the either leg.
SUMMARY OF THE INVENTION
A foot operated door opener is formed as a triangular frame. The frame has an angular apex joint opposite the longer leg. The apex has an axle therethrough which is rotatably connected to a wall adjacent a sliding door. Pressure on the end of one leg of the frame causes rotation of the frame about the axle. The rotation causes another end of the frame to engage the sliding door and move it laterally to partially open the door.
Accordingly, it is an objective of the instant invention to teach a simple, easily installed foot operated door opener for applying a lateral force to a sliding door.
It is a further objective of the instant invention to teach a sliding door opener with a reinforced lever arms for withstanding repeated usage and large loads without failure.
It is yet another objective of the instant invention to teach a spring loaded door opener that automatically returns to a starting position upon release of foot pressure.
It is a still further objective of the invention teach the provision of a structure to convert arcuate movement to lateral movement and protect the integrity of the door.
Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a perspective of a mounted foot operated opener of this invention in the starting position;
FIG. 2 shows a perspective of a mounted foot operated opener of FIG. 1 in the open position;
FIG. 3 shows an exploded view of the spring loaded axle; and
FIG. 4 shows a perspective of the actuator and strike plate.
DETAILED DESCRIPTION OF THE INVENTION
The foot operated door opener 10 is mounted on a wall 11 adjacent an edge of a door 13 . The bottom 14 of the door slides along the floor 12 . The opener is formed as a planar triangular frame with a horizontal leg 15 and a downwardly extending leg 16 in the starting position. The horizontally and downwardly extending legs, each have one end connected to a longer leg 17 . The plane of the triangular frame is parallel to the plane of the wall, as shown in FIG. 1 . This triangular shape adds reinforcement to both the horizontal and downwardly extending legs.
The other ends of legs 15 and 16 are joined at an apex angle opposite the longer leg 17 . An axle 18 extends through this joint normal to the plane of the opener. The axle 18 is rotatably fixed in a bracket 19 connected to the wall by screws 20 . Other wall fasteners may be used, such as bolts, nails welding or adhesives. In some instances, the bracket 19 may be attached to the door frame adjacent to the door opening. In any event, the bracket is located a horizontal distance from the edge of the door to permit the leg 16 to extend into the door opening in the open position.
A pad 21 is located on leg 15 near the end which connects with the longer leg 17 . This pad may take any form, such as an enlarged horizontally oriented plate, a roughened area of the leg 15 or a rubber pedal fixed on the leg. A plate or pedal may be connected to the leg 15 by screws, bolts, rivets or welding, as a matter of choice. This pedal forms the surface upon which a person may apply pressure to rotate the triangular frame. Normally, a user would step on this pedal and use hie or her weight to move the opener, as shown in FIG. 2 . Other appendages or devices, such as canes and crutches, may be used to operate the pedal. Also, the opener 10 may be placed on the wall at locations other than the height above the floor shown in FIGS. 1 and 2. Because of the length of the legs, from the edge of the door to the foot pedal, there is a lever arm which adds mechanical advantage to the pressure applied to the pedal 21 .
A contact arm 22 is attached near the end of the downwardly extending leg 16 that is connected to the longer leg 17 . The contact arm 22 extends generally horizontally from the triangular frame toward the edge of the door 13 in the same plane as the opener, in the starting position. The length of the contact arm corresponds to the distance between the bracket 19 and the door. When the bracket 19 is located adjacent to the door opening the contact arm may be omitted (not shown). The contact arm may be an integral portion of the triangular frame or it may be connected to the frame by screws or bolts or welding. The contact arm 22 has an actuator 24 which engages the door 13 . As shown in FIGS. 2 and 4, the actuator 24 is perpendicular to the axis of the contact arm. The length of the actuator corresponds to the distance the triangular frame 10 is offset from the edge of the door.
The axle 18 , as shown in FIG. 3, is spring loaded to return to the starting position after rotation to the open position. A coil spring 25 encircles the axle 18 with one end of the coil attached to the bracket 19 in aperture 26 and the other end connected to the triangular frame in aperture 27 . When force is applied to the pedal 21 , the opener rotates to the open position causing the spring to store torsional energy. When the force is removed the spring 25 unloads and returns the frame to the starting position. While a coil spring has been shown and described, other spring arrangements may be used, such as a cam and leaf.
A strike plate 23 is attached to the edge of the door 13 . As shown in FIG. 4, the strike plate is L-shaped in cross section. It has two planar flanges 28 and 30 oriented normal to each other. Flange 28 is connected to the door 13 by screws 29 though other fasteners may be used. Flange 30 forms a planar surface normal to the plane of the door. The flange 30 is frictionally connected to actuator 24 . As pressure is applied to pedal 21 , contact arm 22 moves arcuately in response to the rotation of leg 16 about axle 18 . The arcuate movement produce a lateral vector and a vertical vector in the movement of the actuator 24 . The lateral vector causes the door to move along the floor and the vertical vector causes the actuator 24 to move upwardly along flange 30 . Depending on the particular installation of the door and framing, the height of flange 30 may vary or be omitted.
In the open position, shown in FIG. 2, the edge of the door is spaced from the wall a sufficient distance to allow partial entry into the door opening. A user may use a hand, arm, leg or shoulder to gain purchase against the edge of the door to complete the opening of the door.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings.
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A foot operated door opener is formed as a triangular frame. The frame has an angular apex joint opposite the longer leg. The apex has an axle therethrough which is rotatably connected to a wall adjacent a sliding door. Pressure on the end of one leg of the frame causes rotation of the frame about the axle. The rotation causes another end of the frame to engage the sliding door and move it laterally to partially open the door.
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BACKGROUND OF THE INVENTION
This invention relates to a pleating machine for pleating cloth with mutually converging folds, in particular a machine operative to form converging folds in the cloth and defining "upright" flaps therein i.e. folds extending crosswise to the face of a cloth piece to be pleated.
Pleating machines have been developed in the past which, to produce pleated cloth as above, were equipped with an angularly oscillating entrainment arm adapted to impart cloth to be pleated with a step-like forward movement, and with a movable abutment wall whereat said arm would form flaps or pleats.
The abutment wall was, in fact, arranged to initially act as an anvil member for the cloth being pleated, at the forward travel limit of the entrainment arm, and then raised and shifted to allow the formed pleats to move toward guiding members for the pleated cloth.
This prior approach, while seemingly workable, has proved inadequate to provide pleated cloth of an acceptable quality. In fact, the upward movement of said walls tends to drag the pleated cloth therealong if the entrainment arm is held at a position close to the wall. In the opposite case, the position of the folded flap remains uncertain and the fold has inadequately defined edges. Furthermore, said wall, in returning to its starting position from above, may easily interfere with the flap just formed and squeeze it or at least contact it in a wrong position.
With very flabby fabrics, it has also been found that the entrainment arm is unable to displace such fabrics accurately in an angular direction; that portion of said fabrics which is not caught between the arm and abutment wall being more likely to follow a path of linear direct approach to the abutment wall than an arched path toward it.
Lastly, the various component members of such prior machines have complex constructions, and are not readily adaptable to meet changing requirements as regards the depth and inclination of the pleats.
For these reasons, pleated cloth formed with converging or so-called "soleil" folds, is mostly processed manually by inserting cloth portions between a pair of pleated cardboards, and then pressing said cardboards accordion-like and loading them into appropriate devices to set the cloth in its pleated condition by a heat treatment thereof.
However, is may be appreciated that such a technique is unsatifactory both time- and labor-wise, and that such empirical procedures are practically unacceptable where large volume production is involved.
SUMMARY OF THE INVENTION
It is a primary object of this invention to obviate the problems of prior art by providing a pleating machine which can form cloth with mutually converging folds in a rapid and economical way, as well as a qualitatively satisfactory one.
A further object of the invention is to provide a pleating machine which is highly reliable in operation, i.e. which can operate in a highly accurate manner to yield high quality pleated cloth even with flabby fabrics, without involving the availability of skilled personnel or critical adjustment practices.
It is another object of this invention to provide a pleating machine which is basically simple and relatively inexpensive, while affording pleating capabilities to a variety of patterns.
These and other objects, such as will be apparent hereinafter, are achieved by a pleating machine for pleating cloth with mutally converging folds, which comprises: a working platform, an angularly oscillating arm on said platform adapted to impart a cloth placed on said platform with a step-like forward movement, a lifting abutment wall adapted to contact said cloth adjacently a travel limit of said arm, and guide members effective to guide pleated cloth and being located adjacent said wall on the opposite side to said arm; the machine being characterized in that said abutment wall and said arm are both configured comb-like to be mutually interleaved, and in that control members and guiding elements are provided for said abutment wall to be subjected to cyclic oscillation from a position whereat said cloth is clamped against said platform to an inserted position in said arm after moving over and past a cloth flap which has been folded over by said arm and effective to then press said flap against said guiding members for the pleated cloth.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will be more readily understood from the following description of a preferred, but not exclusive, embodiment of this pleating machine, to be read in conjunction with the accompanying illustrative drawings, where:
FIG. 1 is a schematic plan view of the pleating machine of this invention, with some components thereof shown cut away;
FIG. 2 is a detail view of the machine drawn to a much enlarged scale with respect to FIG. 1;
FIG. 3 shows for illustration purposes a pleated cloth formed on the machine of this invention;
FIGS. 4 and 5 are, respectively, a front view and side view, partly in section, of the machine of FIG. 1;
FIG. 6 illustrates the machine control members as arranged on a lateral side thereof;
FIG. 7 illustrates the machine construction in the area of its center pin;
FIGS. 8 to 13 illustrate diagramatically the operation of some of the main components of this machine;
FIG. 14 is a sectional view of the pleated cloth guiding members in a second embodiment of the inventive machine;
FIG. 15 is an enlarged scale view of one portion of FIG. 14;
FIG. 16 is a perspective view showing one portion of FIG. 15 in an upside down position;
FIG. 17 is a cross-sectional view of the guiding members shown in FIG. 14; and
FIG. 18 is a partly exploded perspective view of a pleated cloth dragging and gathering device which may be incorporated to the machine of this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Making reference to the drawing views, a pleating machine according to this invention is shown generally at 1. The machine is set up to form a pleated cloth 2 of the type shown in FIG. 3 with mutually converging folds, and essentially comprises a working platform 3, an entrainment arm 4 mounted pivotally on the platform 3 about a pin 5, a lifting abutment wall 6 located adjacent a travel limit position of the arm 4, and guiding members 7 for the pleated cloth 2.
The platform 3 is particularly brought out in FIGS. 1,4 and 5. Its shape is circular, suitable for positioning pre-shaped, but not yet pleated, fabric portions 8, and extends around a pin 5 which forms the pivot center for the arm 4. Further, the platform 3 is peculiarly pivotable about that same pin with a timed motion to that of the arm 4.
More specifically, the platform 3 is rotated step-like concurrently with the forward movements of the arm 4 which is driven by a main cylinder 9 (FIG. 1) effective to reciprocatingly oscillate the arm 4. During the return movements of the arm 4, the platform 3 is held stationary.
Advantageously, it is the main cylinder 9 itself which controls both the reciprocation of the arm 4 and advancement movements of the platform 3. In fact, and as shown in FIG. 7, the arm 4 is terminated at the pin 5 with a plate 10 which is attached to a center pin 11 of the pin 5 connected to the platform 3 through a freewheel mechanism 12 for rotation in one direction only. The freewheel mechanism 12 is made rigid with the platform 3 by means of a cup-like extension 13, also shown in FIG. 7. It should be further noted, moreover, that the pin 5 is provided with a set of bearings in engagement with the various elements connected to the pivot pin, in particular, a fixed storage deck 14 overlying the platform 3 as will be explained hereinafter, and a base 15 which provides support for the pivot pin 5 and the machine as a whole.
The base 15 is particularly brought out in FIGS. 4 and 5, and comprises a latticework for direct installation on the floor.
As shown in the drawings, not only does the base 15 support the pin 5 but also a pair of lateral sides extending mainly in a vertical direction which carry substantially all of the components of the machine 1. More particularly, there are provided an outward lateral side 16 engaging with the main cylinder 9 and one end of the arm 4, and an inward lateral side 17 which extends from said pin 5 parallel to the former lateral side 16 beyond the platform 3 to connect, through an expansion sectional member 17a thereof, to a base beam 15a, as brought out in FIGS. 4 and 5. The lateral sides 16 and 17 also carry control and guiding devices 49 for the wall 6, while the controls for the arm 4 are only provided on the outward lateral side 16, since the arm 4 is merely connected to the pin 5 at the inward lateral side 17.
As shown in FIG. 6, the controls for the arm 4 are formed, additionally to said main cylinder 9, by a runway 18 along which the arm 4 can slide through a pivot pin 19 projecting from a second end plate 20 of the arm. The runway 18 extends substantially parallel to the platform 3 and may be lifted perpendicularly from the latter by means of an auxiliary cylinder 21 supported by the outward lateral side 16 and said runway 8 has its stroke length limited by adjustable mechanical travel end stops 22 and microswitches 23. In order to follow the movements of the arm 4 in the vertical direction, the main cylinder 9 has at least one end 9a swivel connected (FIG. 1).
The cited control and guiding devices 49 for the wall 6 are arranged to act on an upper crosspiece 24 of the wall 6, and comprise a lifter cylinder 25, suspended from an upper swivel mount 26 and ending with its rod in a lower supporting swivel connection 27 engaging directly with the crosspiece 24. Said devices 49 further comprise a translator cylinder 28 perpendicular to the lifter cylinder 25 and acting on a vertical tube 29 made rigid to the crosspiece 24. Finally, a guide 30 is provided which defines the path of cyclic movement of the crosspiece 24. The latter engages in the guide 30 through a lug 31. All the movements of the lifter cylinder 25 and translator cylinder 28, on each lateral sides 16,17, are controlled by additional microswitches 32.
FIGS. 1,2 and 6 show the construction of the arm 4 and wall 6.
It should be noted that the arm 4 is defined, between its ends, by an angle crosspiece 33 which peculiarly supports segments 34 extending perpendicularly to the angle crosspiece 33 and being spaced apart at equal intervals. It is also contemplated that the distance separating the various segments 34 be substantially equal to the thickness dimension of each segment 34, in a parallel direction to the angle crosspiece 33 and length direction of the arm 4. The segments 34 overlap a lower blade 35, also attached to the angle crosspiece 34, which is preferably formed by a set of small blades laid side-by-side and being partly independent of each other, as shown in FIG. 2. It is further contemplated that the blade 35 be located somewhat away from the segments 34 so that it may be caused to oscillate with respect to the same. As a whole, the front portion of the arm 4 has a comb-like configuration wherein the segments 34 extend in the height direction to match the lengths of pleats to be formed.
The abutment wall 6 also has a comb-like configuration. In fact, it is defined by the cited crosspiece 24 and a set of rods 36 depending from the crosspiece 24. The rods 36 mainly extend in a substantially vertical direction, and advantageously, engage the crosspiece 24 elastically. In fact, as shown in FIG. 6, each of the rods 36 is conncted at the top, within the crosspiece 24, to a compression spring 37 the position whereof can be adjusted by means of a screw element 38. Each rod 36 is retained by means of a pin 39 passed through the crosspiece 24 and a vertically extending slot formed in the rod itself.
As brought out in FIGS. 2 and 6, the rods 36 are quite thin and extend, in a parallel direction to the crosspiece 24, over distances of smaller but comparable length to the distance separating the segments 34. Furthermore, the rods 36 extend in the height direction such that the crosspiece 24 can always be held above the segments 34. Thus, in practice, the rods 36 may be inserted in between the segments 34 of the arm 4.
The home or lowered position of the crosspiece 24 is selected to prearrange the rods 36 at the front ends of the segments 34 with the arm 4 at its foremost travel limit position. Further, in this home position, the rods 36 and blade 35 of the arm 4 will rest on the cited storage deck 14. The latter is close against the pivoting platform 3, whereto it is connected by a bevel 40. The storage deck 14, which is stationary, is extended to span the area between the lateral sides 16 and 17, at the cited guiding members 7.
As shown in FIG. 6, the storage deck 14 is formed with channels 41 adjacent the wall 6 which are connected to air jet supply members. The latter members are not shown because known per se. Further, the storage deck 14 is provided, at an intermediate portion thereof, with internal resistance heaters for heat processing a previously pleated cloth.
The guide members 7 comprise, inter alia, a cover 42 whose construction is brought out in FIG. 4. The cover 42 is substantially defined by an upper plate 43 which is supported by a lifting member 47 at the outward lateral side 16 and is at the other end pivotally connected by hinges 44 located at the expansion sectional member 17a of the inward lateral side 17.
As shown in FIG. 1, the upper plate 43 is subdivided into portions which are held together by sectional members 45, one of which is connected to the hinges 44 through bridge elements 46. It is further contemplated that a center portion of the upper plate 43 be provided with internally mounted electric resistors, similarly to the intermediate portion of the storage deck 14.
FIG. 2 shows how, at the abutment wall 6, the upper plate 43 is terminated below the crosspiece 24 with a serration adapted to allow it to be inserted between rods 36 of the wall 6. The segments 34 of the arm 4 are merely brought close to the upper plate 43, but it would also be possible to partly insert the segments below the plate 43, where the terminating teeth of the latter extend beyond the rods 36.
FIG. 14 to 18 show a second embodiment of the machine 1, wherein the guide members 7 are configured to define an advantageous device for heat treating and guiding the pleated cloth 2. In fact, both the storage deck 14 and upper plate 43 are equally divided into consecutive transverse portions directly and selectively joined to heating members and cooling members.
As brought out by FIG. 14, first cross portions 113a and 113b are provided, respectively for the storage deck 14 and upper plate 43, these being mere containment portions which cooperate to hold the folded flaps in a compact position. These first portions are followed by second cross portions 114a and 114b, which form proper plate heaters which may reach a very high temperature. The second cross portions 114a, 114b contain, in fact, electric resistance heaters, shown schematically in FIG. 14. The heat generated by the second cross portions 114a, 114b is conducted also to the first cross portions 113a, 113b.
Provided consecutively to the cited second cross portions are third cross portions 115a, 115b, respectively for the storage deck 14 and upper plate 43. The cited third portions serve heat insulation purposes. In fact, the same are formed from thin sheets wherebetween a thermally insulating material is interposed.
Lastly, fourth cross portions 116a, 116b are provided the peculiar construction whereof is shown best in FIGS. 14, 15 and 17. These cross portions are directly connected to cooling members which comprise, advantageously, a pair of fans 117 adapted to blow air at a cold temperature or room temperature across the pleated cloth, in a substantially perpendicular direction to the upper plate 43 and substantially parallel to the flaps of the pleated cloth.
Originally the cooling air flow is channeled such as to follow a linear path through both the upper plate 43 and storage deck 14, virtually without escape or deflection in the perpendicular direction to the formed pleats. For this purpose, mounted on the fourth cross portion 116b, on one side (the outward side), is a hood 118 effective to confine the air flow generated by the fans 117, while on the other side (at the inner face), a first grid 119 is located which is substantially tailored to fit the hood 118. Of course, the fourth cross portion 116b would be of hollow construction between the first grid 119 and hood 118.
Likewise, the fourth cross portion 116a, formed in the storage deck 14, is made hollow at a broad center portion thereof, and supports the pleated cloth through a second grid 120 wherethrough the air jet from the fans 117 flows.
Of course, the first grid 119 and second grid 120 are so arranged as not to break the surface continuity of the storage deck 14 and upper plate 43.
The pleated cloth runs between the storage deck 14 and upper plate 43 at a proportioned speed to the requirements of heat treatment, on an impulse from the comb-like arm 4 which, by oscillating cyclically, continuously loads freshly formed flaps onto the storage deck 14 in cooperation with the abutment wall 6.
In order for the heat treatment to be properly followed at the beginning and end of the processing steps and in the instance of individual cloth portions being processed, it is contemplated, according to the invention, that the storage deck 14 and upper plate 43 be engaged by auxiliary elements operative to control the cloth movement. These auxiliary elements are shown in FIGS. 17 and 18.
As shown in FIG. 17, on either sides of the storage deck 14 two racks 121 are laid which, in conjunction with a cross rod 122 and motor unit 123 (FIG. 18), form an entrainment device 134 which may be activated (once all the cloth 2 has been transferred past the abutment wall 6) by the insertion of the cross rod 122 and starting of the motor unit 123. The cross rod 122 is inserted in between the arm 4 and abutment wall 6 after the latter has been raised.
In detail, the racks 121 are driven axially by gears 125 formed on a control rod 126 extending transversely to the racks 121 and being located downstream of the upper plate 43.
The control rod 126 is rotated by the motor unit 123, which includes a pair of pulleys 127, a drive belt 128 and an electric motor 129. The latter is at a lower position than the storage deck 14, on one lateral side of the pleating machine.
The cross rod 122, which is interchangeable and shaped to match the folded flaps being formed, may be snap engaged between the front ends of the racks 121. To that aim, the cross rod 122 may be positioned with one end to abut on a projection 130 from the front of one of the racks 121, and with the other end to engage with the other rack 121, by means of a movable blade 131 which is controlled manually against the bias of a compression spring 132.
The speed imparted by the electric motor 129 is correlated functionally to the heat treatment provided for the cloth, and accordingly, will be the slower the more powerful said treatment is to be.
Finally, the stop positions for the entrainment device 134 are determined by a pair of microswitches supported on the side strip 124 and adapted to sense the position of small pegs protruding from the ends of the racks 121. The microswitches control the electric motor 129.
In cooperation with the entrainment device 134 just described, but at an independent and isolated location, a slide 135 may be arranged to operate for confining the pleated cloth on the opposite side to the cross rod 122. Whereas the entrainment device 134 is operated each time that a working step is completed, the slice 135 is operated each time that a working step is started, thereby keeping the folded flaps compactly arranged by resisting their tendency to skid until the same have reached such a number as not to require any further holding and supporting actions. The slide 135 may have various shapes and dimensions, and includes a front element 136 shaped to match flaps to be formed, and a pair of guiding runways 137 substantially slidable alongside the racks 121. The runways 137 may have various lengths and be optionally provided with wheels and bearings to avoid tripping the slide 135.
FIGS. 14 to 16 illustrate how the resistance of the pleated cloth to forward movement may be increased, to increase the degree of mutual compaction of the pleats, also at the upper plate 43 by providing additional auxiliary elements for controlling the cloth movement in the form of pressure members 139. More specifically, plural blades 140 are provided each being associated with supporting members adapted to allow them to bow. The blades 140 are arranged side-by-side at the lower strip of the fourth cross portion 116b of the upper plate 43. In practice, the blades 140 are set to straddle the first grid 119, and advantageously, formed with cutouts 141 not to hinder the flow of air. The cited supporting members comprise, for example, a strip 142 effective to lock one end of the blades 140, and a bridge element 143 located on the opposite side to the strip 142 and engaging with a respective blade 140 with the interposition of a tension spring 144, whose tension may be adjusted by means of a screw element 145.
FIG. 14 shows also an opening or inspection port 148 adapted to permit direct inspection of pleats just formed; the opening 148 being formed in the upper plate 43 in the proximity of the abutment wall 6.
The opening 148 is provided with a clear cloth confining element. Finally, FIG. 17 shows jaws 150 for controlling the movements of the platform 3. In particular, a first pair of electromagnetic drag jaws 150 is provided attached to the arm 4 and allowed to move along with it, as well as a second pair of electromagnetic hold-back jaws 150 which are mounted stationary (FIG. 17).
It is contemplated that the drag or pulling electromagnetic jaws engage with and entrain rotatively the platform 3, while the hold-back or braking electromagnetic jaws are held open, and the latter become likewise operative with the electromagnetic drag jaws in the open position. The jaws 150 cooperate with the freewheel mechanism 12, but alternatively, may replace it.
The operation of this pleating machine will be next described with reference to FIGS. 1 to 13.
Initially the machine would be in the position shown in FIG. 8, with the arm 4 at its rearmost travel limit from the wall 6. A portion 8 of a cloth to be pleated is laid onto the platform 3. The abutment wall 6 is in its lowered position and acts as a stop for the not yet pleated cloth portion. The latter is lifted off the platform 8 and overlaps the storage deck 14, moving past the bevel 40. Any pleated cloth 2 present beyond the wall 6 is held in place by the upper plate 43 of the cover 42. The upper plate 43 enters frontally the spaces between the rods 36 of the wall 6 and moves into a cocked position (FIG. 4) defined by the lifting member 47.
To form a pleat or folded flap in the cloth, the main cylinder 9 (FIG. 1) is operated to angularly shift the arm 4 closer to the wall 6. During this movement, the arm 4 rotates about the pin 5 whereto it is connected through the plate 10, and on the opposite side runs along the runway 18 through the pin 19. During this working step the runway 18 is held lowered by the auxiliary cylinder 21 and the arm 4 engages its blade 35 with the cloth portion 8. Of preference, the blade 35 is held away from the segments 34, and accordingly, the lowered position for the arm 4 may be defined without any special problem of working tolerance, since any inaccuracies would be accommodated by the blade 35 flexing. Further, in that way, the blade 35 may adapt itself spontaneously to cloths of varying thickness and even overcome possible surface irregularities in the cloths. In this situation, the subdivision of the blade 35 into plural side-by-side blades, as shown in FIG. 2, becomes specially useful.
While the arm 4 is approaching the wall 6, an air jet is issued through the channels 41 which can favour the formation of a pleat even in the instance of exceptionally flabby cloths.
At the same time, the platform 3 is rotated along with the arm 4 by the entrainment action applied by the arm 4 itself through the freewheel mechanism 12 at the pin 5. Thus, the cloth stored on the platform 3 undergoes no pulling or tensioning effect and can retain its position without wrinkling even where particularly flabby in nature.
As brought out in particular by FIGS. 2,6 and 10, the arm 4 is positioned at its travel limit with the segments 34 aligned to gaps between the rods 36, thus forming and squeezing a cloth flap.
Once the new flap has been formed, and (preferably) while the same is being held in position by an air jet through a specially provided channel 41 as well as by the segments 34, the wall 6 is raised and shifted with cyclic oscillation by the action of the lifting cylinder 25 and translator cylinder 28. The path of movement of the wall 6 is dictated by the runway 18 and is such that the rods 36 can move over and past the just formed flap. and enter peculiarly the spaces between the segments 34 behind the flap itself.
This oscillation is shown in FIGS. 11 and 12, and can only take place by virtue of the comb-like configuration of the rods 36 and segments 34. Not only does the comb-like configuration allow insertion of the rods in between the segments but also the rods themselves to be raised without any effect of entrainment of the just formed flap.
In fact, in no case would the segments 34 press the flap in question against the rods 36 and the same present a much totally reduced contact surface to the flap.
During the last portion of the cyclic oscillation, the rods 36 urge the just formed flap toward the guiding members 7 for the pleated cloth 2, where the cloth undergoes a heat treatment resulting from the provision of heated zones at the upper plate 43 of the storage deck 14.
During this final portion of the cyclic oscillation, the rods 36 may interfere with some force with the blade 35 of the arm 4 and/or the storage deck 14. This because the rods 36 are spring mounted according to the invention and hence able to readily accommodate the cyclic oscillation imparted to them as well as the thickness of the pleated cloth.
Finally, the arm 4 is moved rearwardly and lifted by the action of the main cylinder 9 and auxiliary cylinder 21, the latter being operative to raise the runway 18. During this movement, the platform 3 is held stationary, because the freewheel mechanism 12 is configured to only transmit to the platform 3 the movements of the arm 4 toward the wall 6.
Thus, the pleating machine 1 can return to its original condition, as shown in FIGS. 1 and 8. Pleating is continued to completion of each cloth portion 8 or, expediently, in a continuous fashion so as to pleat without interruptions various portions 8 laid sequentially onto the platform 3, as shown in FIG. 1. This continuous process is made possible by the rotary movement of the platform 3, which spontaneously feeds in the cloth to be pleated and avoids tensioning and pulling it.
In the embodiment of FIGS. 14 to 18, full heat treatment of the pleated cloth is also carried out. In fact, the machine first applies heat to the cloth and then cools it off. Cooling is most effective because actual tests have shown that mere heating may not be sufficient; in exiting the machine, the "upright" pleats tend spontaneously to open up and let the cloth lay down. This partial collapse produces permanent adverse effects, since the cloth would still be hot. It is, therefore, necessary to not only heat but also cool for the completion of the entire heat treatment cycle prior to the pleats leaving the machine that formed them.
The inventive device offers qualitatively very high results: the resulting pleats are permanently stable. When the machine processes individual cloth portions, or possibly just a few wearing apparel articles, the machine stops while a large part of the pleated cloth is yet to move through the cited heat treatment device. Under no circumstances can the cloth be removed manually because this would result in the pleats collapsing and in an imperfectly controlled residence time of the same in the heat treatment area.
The situation is serious during the adjustment procedure of the heat treatment device, when just individual clothing articles are fed thereinto for testing purposes.
With the entrainment device 134 and slide 135 adjustment of the device operating parameters is also facilitated where cloth portions of very short length are to be treated. The treatment of hemmed cloths also poses no problems because the cloth running may be adjusted as desired by means of the pegs 146 acting on the blades 140.
In fact, an edge of the pleated cloth may include a hem which, owing to its thickness, would tend to distort the pleated cloth into a fan-like shape. Thus, a more powerful frictional action must be applied to the hem area to prevent the mutual compaction of the cloth flaps from being reduced.
The invention as disclosed is susceptible to many modifications and variations without departing from the scope of the instant inventive idea. Further, all of the details may be replaced with other, technically equivalent elements.
In practicing the invention, the materials used and dimensions may be any selected ones contingent on individual requirements.
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The invention relates to the field of cloth pleating machines, and in particular, to a pleating machine for pleating cloth with mutually converging folds. The technical problem to be solved was that of providing a pleating machine which could also work accurately and reliably on highly flabby and/or hard-to-fold fabrics. The problem has been solved by providing a pleating machine having an angularly oscillating arm and an abutment wall for said arm, which are configured comb-like to be mutually interleaved, and provided with control and guiding devices for said wall which are operative to drive the same through a cyclic oscillation along a closed path causing said wall to move from a position close against a cloth to be pleated to one of insertion in said arm over and past a cloth flap which has been folded by said arm.
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BACKGROUND OF THE INVENTION
The present invention was developed for use with an overedge sewing machine but could be used with any type of machine in which a chain is produced after the completion of a seam; and, it is desired to cut the chain, retain the cut end of the chain that leads back to the needle and to sew the retained chain end into the next seam.
A device carried by the presser foot of a sewing machine for severing a chain of stitches extending between a sewn workpiece and the needle of the machine, retaining the severed end of the chain that extends from the needle and guiding the retained chain such that it is incorporated into the seam of stitches formed in the following workpiece is shown in U.S. Pat. No. 4,040,370. The device of this prior art patent is difficult for an operator to use and thus requires a relatively long time period to complete the operation. In this prior art device, after completing a stitching operation on a workpiece, the operator must slide the sewn workpiece along the bevel 23 and must then cause the chain to enter the slot 16. The patent implies that the bevel 23 in some way assists the operator in causing the chain to enter the slot 16; however, the patent does not explain how this assistance is provided. The bevel 23 is parallel to slot 16 and it is apparent that after the operator slides the workpiece along bevel 23, the operator must then reverse the direction of the workpiece a full 180° and index it to the side if the chain is to enter the slot 16. After getting the chain to the slot 16, the operator must then insert the chain beneath the leaf spring 19 which grips the chain. The portion of the chain that extends from where it is gripped by leaf spring 19 to the workpiece is then drawn by the operator toward the blade 21 where it is cut. Thus, the operator must manipulate the workpiece and connected chain in a stop and start maze-like pattern to complete the desired operation.
Not only is the use of this prior art device time consuming it is not ergonomically sound. Commercial sewing machine operators perform operations such as cutting a stitch chain and incorporating the retained chain in the next seam thousands of times in an eight hour work day. When the pattern of movement that an operator's hand must follow to perform the task is awkward and tortious as it is in the above prior art device, it can result in physical problems, such as carpal tunnel syndrome, to the operator who must perform the operation thousands of times each work day.
The thread used to produce the chain between successive workpieces is wasted material and thus cost savings can be realized by minimizing the length of chain. The commercially available devices that are available to cut the chain and retain the cut end so that it can be sewn into the next seam require relatively long chain lengths and thus add unnecessary cost to the finished product.
For the foregoing reasons there is a need for an ergonomically sound apparatus that will allow a sewing machine operator to produce a relatively short stitch chain at the end of a seam and in a single smooth motion cause the chain to be severed and the end of the chain that extends from the needle retained and guided into the next seam.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus that will permit a sewing machine operator to produce a stitch chain of a minimum length at the end of a seam and in a single smooth ergonomic motion cause the chain to be severed and the end of the chain that extends from the needle retained and guided into the next seam.
This invention can be used in sewing machines that produce an overedge, for example stitch type 504 as defined in the United States Government Specification Booklet 751a. The class 39500 machine produced by Union Special Corporation is a commercially available machine that can produce the type 504 stitch. Reference is hereby made to co-pending U.S. patent application, Ser. No. 08/273,774, now U.S. Pat. No. 5,465,674, for a disclosure of an overedge stitch sewing machine.
The apparatus of this invention requires a chain length of about one inch which reduces the cost of the finished product by minimizing waste which does not add to the value of the finished product. Furthermore, the sewing machine operator can in a single smooth sweeping movement cause the chain to be cut and the end retained in a position where it will be sewn into the next seam. This operation can be performed very quickly and in an ergonomically sound manner. Another advantage of this invention is that the presser foot can be raised and lowered while the chain end is being retained without the chain end being pulled from the chain clamp.
The present invention is directed to an apparatus consisting of a presser foot having a forward upwardly turned toe, the bottom surface of which functions to guide the chain to the chain cutter and retainer.
The present invention is also directed to an apparatus consisting of a knife holder member that is mounted on said presser foot rearwardly of said upwardly turned toe that includes a flat vertical chain gripping surface that merges into a vertical flared surface that is forward of said first flat vertical chain gripping surface.
The present invention is directed to an apparatus consisting of a chain clamping member including a flat vertical chain gripping surface and a flared portion that extends forward of its flat vertical chain gripping surface and flares outwardly therefrom.
The present invention is directed to an apparatus consisting of a biasing device for urging the chain clamping member toward the knife holder such that the flat vertical chain gripping surface are biased into engagement with each other.
The present invention is furthermore directed to an apparatus consisting of a chain cutting knife that is carried by the knife holder such that it extends across the upper horizontal edges of the chain gripping surfaces.
For the foregoing reasons there is a need for an apparatus that will allow a sewing machine operator to produce a relatively short chain at the end of a seam and in a single smooth motion cause the chain to be severed and the end of the chain that extends from the needle retained and guided into the next seam.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show an embodiment of the invention which will be described with reference to the drawings in which:
FIG. 1 is a plan view of the presser foot with only the knife holder mounted thereon.
FIG. 2 is a side view of the presser foot.
FIG. 3 is a bottom view of the presser foot.
FIG. 4 is an exploded perspective view of the knife holder and chain clamp.
FIG. 5 is a plan view of the presser foot with the chain cutting and retaining apparatus mounted thereon.
FIG. 6 is a front view of the presser foot with the chain cutting and retaining apparatus mounted thereon.
FIG. 7 is a side view of the presser foot with the chain cutting and retaining apparatus mounted thereon.
FIG. 8 is a perspective view of the presser foot with the chain cutting and retaining apparatus mounted thereon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a plan view of the presser foot 10 with the knife holder or first chain gripping member 30 secured thereto by a screw 16. The presser foot 10 has a forward upturned toe portion 11. The surface 12 of the presser foot 10 has been formed by cutting away the corner of the upturned toe portion 11 at an angle of about 30 degrees to the line of feed such that surface 12 flares away from the line of feed and can function to guide the chain between the chain clamping surfaces. When making an overedge stitch, the fabric trimming knife trims the edge of the fabric such that the trimmed edge lies along edge 14 of the presser foot. The other longitudinal edge of the presser foot is identified as edge 15. A portion of the bottom surface of the presser foot 10, seen as a broken line 20 in this view, has been removed and a radius 22, also seen as broken lines in this view, has been cut into the bottom surface. The radius 22 is in alignment with the needle. The removed portion forms a surface that is elevated from the presser foot bottom surface and thus creates a space or cavity for receiving and containing the retained chain as a subsequent workpiece is being stitched.
The bottom surface of the presser foot is illustrated in FIG. 3. In this view the portion 20 of the bottom surface that has been removed and the radius 22 are seen in full lines.
In the side view, FIG. 2, it is apparent that the radius 22 is at an angle of about 10 degrees to the horizonal and will function to align the cut chain with the needle. This view is helpful to visualize how the retained chain will be properly aligned with the needle and will be sewn into the initial portion of the successive seam.
In the perspective view of the knife holder 30 and chain clamp 40 seen in FIG. 4, the top surface 32 of the knife holder 30 is shown as flat and at an angle of about 10° to the horizontal. Thus, the height of the knife holder 30 is greatest at the intersection 39 which is a substantially horizontal edge of the top surface 32 with the first flat vertical chain gripping surface 34. A notch 35 is cut into the corner of the knife holder 30 for the reception of the pivot arm 44 of the chain clamp 40. A threaded hole 36 is formed in the flat vertical chain gripping surface 34 for the reception of the spring screw 50 which is a component of the biasing device that functions to force the chain clamp 40 against the knife holder 30. A bore 37 is formed in the top surface 32 for the reception of screw 16 that secures the knife holder 30 to the presser foot 10. A threaded hole 38 is formed in the top surface 32 for the reception of the knife screw 64 that secures the knife 60 to the top surface 32 of the knife holder 30.
The chain clamp 40, is shown in FIG. 4, is spaced away from its position on the knife holder 30 to better illustrate the knife holder 30. The substantially horizontal upper edge 43 of the flat vertical chain gripping surface can be seen in FIG. 4, however only the back surface of the flat vertical chain gripping surface 42 is visible in this view. The pivot arm 44 of the chain clamp 40 and its position relative to the notch 35 of the knife holder 30 is clearly illustrated. The pivot arm 44 extends at a right angle to the flat vertical chain gripping surface 42 and when assembled extends into pivot notch 35 that is formed in the knife holder 30. When the presser foot is fully assembled, the back surface for the notch 35 is formed by the forward edge 82 of the stitch tongue 80. The forward end 46 of the chain clamp 40 is flared out to extend away from its flat vertical chain gripping surface 42. The flared forward end 46 forms with the surface 12 of the presser foot a rearwardly converging guide for the chain. A spring screw aperture 48 is formed in the flat vertical chain gripping surface 42 through which the spring screw 50 freely extends.
As is best seen in FIG. 6, a coil spring 52 surrounds the shank of spring screw 50 and utilizes the head 56 of the spring screw as a reaction surface. The shank of the spring screw 50 extends freely through the spring screw aperture 48 of the chain clamp 40 and is threaded into the threaded hole 36 formed in the knife holder 30. When the chain is located between the vertical chain gripping surfaces 34 and 42, the chain clamp 40 pivots away from the knife holder 30 about its pivot arm 44. The spring 52 biases the pivot arm 44 into the notch 35 and thereby confines the chain clamp 40 in its movement. During this pivotal movement, the chain clamp 40 is also guided in its movement by the aperture 48 sliding along the shank 54 of spring screw 50. Thus, the movement of the chain clamp 40 is reliably confined to its intended path. The chain clamp 40 has a semi-circular shaped tab 49 that extends generally horizontal from its upper edge. Tab 49 overlies the coil spring 52 and spring screw 50 to protect the operator from being cut by the knife 60 as well as to prevent loose threads from becoming entangled.
As best seen in FIGS. 6 and 8 knife 60 has a sharpened cutting edge 62 and a mounting slot 66. The knife 60 is secured to the top surface 32 of the knife holder 30 by a knife screw 64 that extends through the slot 66 and is received in the threaded hole 38 formed in the top surface 32 of the knife holder. It should be noted that the top surface 32 is at an angle of about 10 degrees to the horizontal which causes the cutting edge 62 to be at a small angle to the horizontal. It has been found that when the cutting edge 62 is inclined at an angle of about 10° the cutting is improved. This relationship of the cutting edge 62 to the horizontal is best seen in FIG. 6. The converging guide formed by the surface 12 of the presser foot 10 and the forward flared end 46 of the chain clamp 40 is also clearly shown in FIG. 6. The cutting edge 62 of the knife 60 extends across the converging guide at a small angle to the horizontal. The position of the cutting edge 62 relative to the converging chain guide can be adjusted by loosening the knife screw 64, adjusting the position of the knife on the top surface 32 and then tightening the screw 64.
The stitch tongue 80 has a forward edge 82 that forms the rear surface of the pivot notch 35 in which is received the pivot arm 44 of the chain clamp 40. The stitch tongue 80 and hinge plate 84 are secured to the presser foot 10 by a screw 86. A chain shield 90 is secured to the upper rear surface of the presser foot 10 by a screw 92.
An example of how the apparatus of this invention is used will now be described. In an overedging operation, the operator after completing the seam, chains off approximately one inch. The operator then lifts the presser foot, grasp the workpiece, and moves it to the left and to the front of the presser foot. In performing this initial movement the chain slides along the edge 15 of the presser foot and then across the bottom surface of the upturned toe 11. The chain then enters the V-shaped groove formed of surface 12 and the forward flared end 46 of the chain clamp 40. The sweeping movement of the workpiece is then directed upwardly bringing the chain up into the chain clamp and against the cutting edge 62 of the knife 60. As the chain is guided between the flat vertical chain gripping surfaces 34 and 42, it is also being guided into the cavity formed by the radius 22. The operator continues the smooth sweeping movement upward and to the left. This final movement causes the chain to be cut and the separated workpiece is stacked to the left of the operator. Thus, the retained chain extends downward from the flat vertical chain gripping surfaces 34 and 42 into the radius 22 and back to the needle. The next workpiece is then placed under the presser foot and the presser foot is lowered. As the presser foot is lowered onto the work product, the retained chain is contained in the cavity formed by the removed portion 20. The provision of this cavity permits the chain to be easily pulled from the retainer without binding through the cavity and the radius 22 as stitching begins. If it is necessary to raise the presser foot, for example to reposition the workpiece, the chain will return to its original attitude and will not be accidently pulled from the retainer.
While the invention has heretofore been described in detail with particular reference to an illustrated embodiment of the apparatus, it is to be understood that variations, modifications and the use of equivalent mechanisms can be effected without departing from the scope of this invention. It is, therefore, intended that such changes and modifications be covered by the following claims.
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A mechanical latch tacking device carried by the toe of the sewing machine presser foot that will allow the operator to produce a relatively short stitch chain at the end of a seam and in a single smooth ergonomical motion cause the chain to be severed and the end of the chain that extends from the needle retained in a location where the next workpiece is started the retained chain will be sewn into the seam.
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BACKGROUND OF THE INVENTION
This invention relates to a device provided in a fiber processing (spinning preparation) machine, for example, a carding machine, a cleaner or the like for measuring distances between facing surfaces. The machine has a clothed roll which cooperates with a counter element, for example, a closure member and/or a clothed carding element. At least one stationary sensor is provided, and with the counter element a setting arrangement is associated for varying the radial distance between the roll clothing and the counter element.
The distance between the carding cylinder clothing and a facing component is of substantial significance as concerns the carding machine and properties of the fiber. The result of the carding process such as fiber cleaning, nep formation and fiber shortening is largely dependent from the carding gap, that is, the distance between the cylinder clothing and the clothing of the traveling flats or stationary carding elements. The channeling of air about the carding cylinder and heat removal are also dependent from the distance between the cylinder clothing and the clothed or unclothed surfaces, such as mote knife or housing shells. Such clearances are affected by various, partially counteracting factors. A wear of facing clothings leads to an enlargement of the carding gap which, in turn, results in an increase of the nep number and a decrease of the fiber shortening. An increase of the cylinder rpm, for example, for enhancing the cleaning effect, results in an enlargement of the cylinder including its clothing because of the centrifugal forces and thus diminishes the carding gap. Further, when large quantities of fiber or particular types of fiber, for example, chemical fibers are processed, then because of the temperature increase the carding cylinder expands to a greater extent than other, neighboring machine components, resulting in a decrease of the distances of the cylinder clothing from adjoining components.
The carding clearance is affected particularly by the machine settings, on the one hand, and the condition of the clothing, on the other hand. The most important carding clearance of a card equipped with traveling flats is in the principal carding zone, that is, between the carding cylinder and the traveling flats assembly. Of the two clothings which define the carding clearance at least one is in motion (in most cases both are moving). To increase the output of the card, it has been desirable to select the operating rpm, that is, the operating speed of the movable elements, to be as high as permitted by the fiber processing technology. The working clearance is measured in the radial direction (starting from the rotary axis) of the carding cylinder.
In current carding processes increasingly larger fiber quantities per unit time are being handled, requiring higher speeds of the working components. Alone an increase of the fiber flow rate leads, because of the mechanical work, to an increased heat generation even if the working surface areas remain constant. At the same time, however, the technological carding results (uniformity of sliver, degree of cleaning, reduction of neps, etc.), are increasingly improved which requires larger working surfaces participating in the carding process and a closer setting of the components to the carding cylinder. The share of chemical fibers to be processed continuously increases. As compared to cotton, chemical fibers generate more heat due to their frictional contact with the working components of the fiber processing machine. In contemporary designs the working components of high-performance carding machines are enclosed from all sides in order to comply with the stringent safety requirements, to prevent particle emission into the spinning room and to minimize the maintenance requirements of the machines. Grates or even open, material-guiding surfaces which provide for an air exchange, belong to the past.
In view of the above-listed circumstances, the heat input into the fiber processing machine is significantly increased while the extent of heat removal by means of convection has been substantially reduced. The resulting significant heat-up of the high-performance carding machines leads to increased thermo-elastic deformations which, because of the non-uniform distribution of the temperature field, affect the set distances of the working components: the distances decrease between the carding cylinder and the traveling flat bars, the doffer, the stationary flat bars as well as the discharge locations. In an extreme case the set gap between the working components may completely disappear because of heat-caused expansions, so that relatively moving working components collide with one another. This results in significant damaging of the high-performance carding machine. Particularly the generation of heat in the working zone of the carding machine may lead to unlike thermal expansions between the structural components in case of excessive temperature differences.
In practice the quality of the clothing of the flat bar clothings is in regular intervals visually verified by an attendant; a wear results in an increase of the carding gap. In a known device, as disclosed in European patent document 801 158, a sensor is provided with which the working distance of carding clothings, that is, the carding gap may be measured. What is thus measured is the effective distance of the clothing points of one clothing between that of the facing clothing of the machine element. The machine element may have a clothing or may be formed by a housing shell segment having a guide surface. The sensor is conceived particularly for measuring the working distance between the carding cylinder and the flat bars of a traveling flats assembly where an optical device, positioned laterally, senses the carding clearance between the carding cylinder and the flat bar clothings. It is a disadvantage of such an arrangement that the measuring results cannot lead to a conclusion concerning a clearance change in the width direction (that is, parallel to the axis of the carding cylinder). Further, a distance between the sensor and the counter element cannot be measured with such a device.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved device of the above-outlined type from which the discussed disadvantages are eliminated and which particularly makes possible to sense distance changes in the width direction and further, which senses in a simple manner only the distance from the carding cylinder clothing and makes possible an optimal setting of such distance.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, a fiber processing machine includes a rotary roll provided with a peripheral clothing; a counter element having a part cooperating with the roll clothing; a sensor stationary relative to the counter element and having a sensing portion facing said roll clothing; and an arrangement for generating a signal representing a distance between the sensing portion and the roll clothing. The distance represents a spacing between the roll clothing and the counter element part.
By the measures according to the invention a wear of the cylinder clothing may be determined, particularly after a longer service period. A distance adjustment results in a change of the effect of the cylinder clothing, either directly with regard to the wear and or indirectly as concerns the clothed or unclothed counter element, particularly the wear of the clothing of a stationary carding element and the heat-caused expansions of the counter element. In this manner, based on a desired value, an optimal setting of the distance between the carding cylinder and the counter element is possible. Distance detection and adjustment may be performed during operation.
The invention has the following additional advantageous features:
The sensor detects the distance between itself and the points of the cylinder clothing.
The sensor detects the distance between the counter surface and the points of the cylinder clothing.
The signals of the sensor are applied as input magnitudes to a control and regulating apparatus for the distance regulation between the counter element and the cylinder clothing.
The radial distance between the cylinder clothing and the counter element may be settable by the position and/or form of the flexible supporting layer which is arranged between the end portions of the counter element and a stationary substrate face of the machine.
The counter element is a housing element of the cylinder.
The cylinder cover is an extruded profiled aluminum component.
The surface of the counter element oriented towards the carding cylinder has a carding clothing.
The sensor detects the wear of the cylinder clothing.
The sensor detects a displacement of the counter element caused by thermal expansion.
The sensor detects a displacement of the cylinder clothing caused by thermal expansion and/or centrifugal forces.
The sensor and setting means are connected to an electronic control and regulating apparatus.
The electronic control and regulating apparatus has a memory for the desired values of the working gaps, and upon exceeding the desired value, a switching operation or display is initiated.
The setting device for adjusting the working gap is actuated by manual input, for example, by means of a push button.
At least one parameter relating to the change of the working gap, such as temperature, is measured for producing a measuring value relating to the working gap.
The position of the flat bar assembly is adjusted as a function of the measuring value for preserving the working gap in accordance with a predetermined value.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is schematic side elevational view of a carding machine incorporating the invention.
FIG. 2 is a fragmentary sectional schematic front elevational view of the device according to the invention, facing the clothing of the carding cylinder.
FIG. 3 is a fragmentary sectional side elevational view of a stationary carding element incorporating the invention.
FIG. 4 is a block diagram of a control circuit associated with a distance detecting sensor according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a carding machine CM which may be, for example, an EXACTACARD DK803 model manufactured by Trützschler GmbH & Co. KG, Mönchengladbach, Germany. The carding machine CM includes a feed roll 1 , a feed table 2 cooperating therewith, licker-ins 3 a , 3 b , 3 c , a carding cylinder 4 having a cylinder clothing 4 a , a direction of rotation 4 b and a rotary axis M, a doffer 5 , a stripping roll 6 , crushing rolls 7 and 8 , a web guiding element 9 , a sliver trumpet 10 , calender rolls 11 , 12 , a traveling flats assembly 13 having traveling flat bars 14 , a coiler can 15 , a coiling device 16 and the device according to the invention including a sensor 19 . The rotary directions of the various roll components of the carding machine are shown by curved arrows drawn therein. A stationary carding segment 27 ′ is positioned between the licker-in 3 c and the rearward end sprocket 13 a of the traveling flats assembly 13 whereas the stationary carding segment 27 ″ is situated between the doffer 5 and the frontal end sprocket 13 b of the traveling flats assembly 13 .
Turning to FIG. 2, three sensors 19 a , 19 b and 19 c are arranged which are spaced from one another parallel to the axial length of the carding cylinder 4 . The respective sensor surfaces 19 ′, 19 ″ and 19 ′″ are oriented towards the clothing 4 a of the carding cylinder 4 and are spaced at a distance a therefrom. Fine-threaded adjustment nuts 21 a , 21 b and 21 c provide for a setting of the distance a for each sensor relative to the cylinder clothing 4 a . The sensors 19 a , 19 b and 19 c are secured in a holding device 22 which is secured stationarily to the lateral shield plates 24 a , 24 b by means of respective screws 23 a and 23 b.
Turning to FIG. 3, a generally semicircular rigid lateral shield plate 24 is secured to the machine frame (not shown) on each side of the carding machine. An arcuate rigid support element 25 is concentrically affixed by casting to the periphery of each shield plate. The support element 25 has an underside and a convex outer face serving as a supporting surface. On the support element 25 a circumferentially wedge-shaped flexible supporting strip 26 is positioned which is made, for example, of a low-friction synthetic material and which has a convex outer surface and a concave inner surface. The concave inner surface lies on the convex surface of the support element 25 in an annular groove thereof and may slide therein in the direction of the arrows A, B. The shifting of the support strip 26 circumferentially in the direction A or B, is, as symbolically illustrated in FIG. 4, effected by a shifting or setting device 35 which includes a driving device such as a motor, a gearing or the like. At opposite axial ends the carding segment 27 ′ is supported on the convex outer face of the support strip 26 , so that as the support strip 26 is circumferentially shifted, it displaces radially the carding segment 27 ′ by a camming effect. On the underside of the carding segment 27 ′ carding elements 27 a are provided, each having a carding clothing 27 b . The circle on which the points of the clothings 27 b lie is designated at 28 . The circle circumscribable about the points of the clothing 4 a of the carding cylinder 4 is designated at 29 . The distance between the circles 28 and 29 is designated at b and is, for example, 0.20 mm. The distance between the convex outer face 26 a and the circle 29 is designated at c. The radius of the convex outer face 26 a is designated at r 1 and the radius of the circle 29 is designated at r 2 . The radii r 1 and r 2 intersect on the cylinder axis M.
The carding segment 27 ′ includes a carrier 30 which holds the two carding elements 24 a in series in the rotary direction 4 b of the carding cylinder 4 . The clothings 24 b of the carding elements 24 a face the clothing 4 a of the carding cylinder 4 . A holding element 31 carrying the sensor 19 is secured to a vertical end face of the carrier 30 .
Also referring to FIG. 4, in case the distance a between the measuring surface 19 ′ of the sensor 19 and the points 29 of the cylinder clothing 4 a decreases, for example, because of thermal expansions, or increases because of a wear of the cylinder clothing 4 a , the sensor emits a signal which is applied by an electric conductor 32 to an electronic evaluating device 33 . The electric signal may be utilized for setting or adjusting a given distance b (desired value) by means of an electronic control and regulating apparatus 34 . For this purpose, the circumferentially wedge-shaped supporting strip 26 is displaced on the circumferential groove of the support member 25 in the direction A or B. As a result of such a shift the carding segment 27 ′ is displaced in the direction of the arrow C or D. The distance b between the clothings 24 b of the carding elements 24 a and the cylinder clothing 4 a is thus accurately adjustable in a simple manner.
The evaluating device 33 which displays and stores the magnitudes detected by the sensor 19 , is connected with the electronic card control device 34 which emits signals for the setting device 35 for shifting the support strip 26 to thus adjust the carding gap (that is, the distance b) between the clothing 24 b of the carding segment 27 ′ and the clothing 4 a of the carding cylinder 4 . At the same time, this information is also applied to a carding information system which may be a KIT model, manufactured by Trützschler GmbH & Co. KG and which forms part of a computer display device 36 where the data of an entire carding group are monitored.
The invention was described, as an example, in conjunction with the clothings 24 b of the carding segment 27 ′, cooperating with the clothing 4 a of the carding cylinder 4 . It is to be understood that the invention also encompasses a non-clothed counter element, for example, a circumferential shell plate shrouding the carding cylinder. In case the sensor 19 according to FIG. 3 is secured to the counter element and the distance b from the counter element decreases (for example, because of a thermal expansion), then according to the measures of the invention, by means of measuring the distance a, the distance b is determined.
Structural features relating to mechanisms for adjusting the working distances by means of shifting the support strip 26 as a function of sensor signals are disclosed, for example, in U.S. Pat. No. 5,918,349 which is incorporated herewith by reference.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A fiber processing machine includes a rotary roll provided with a peripheral clothing; a counter element having a part cooperating with the roll clothing; a sensor stationary relative to the counter element and having a sensing portion facing said roll clothing; and an arrangement for generating a signal representing a distance between the sensing portion and the roll clothing. The distance represents a spacing between the roll clothing and the counter element part.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a socket wrench and more particularly, to an improved socket wrench including a plurality of socket members of varying sizes slidably assembled into the socket wrench in a telescopic manner so that upon utilizing the socket wrench, bolts or nuts having different sizes can be easily driven without any socket replacement.
2. Description of the Prior Art
Various types of conventional socket wrenches are well known in the art. Such socket wrenches have an adjustable members. However, such adjustable socket wrenches are expensive to manufacture, complicated in construction, and difficult in use. Such socket wrenches are shown in the U.S. Pat. Nos. 1,395,656, 1,432,263, 1,456,290, 1,502,044, 1,513,332, 2,743,641, 2,814,227, 3,253,486 and 3,541,901. Also, several types of conventional wrenches are utilized jaws so as to allow the user to adjust the jaws and then match the size of the socket to the size of bolts or nuts to be driven. However, such socket wrenches are not only cumbersome to carry out the adjustment operation but also complex in the overall structure. Therefore, it is difficult to fabricate such wrenches and thus it increases the manufacturing costs. Such socket wrenches are shown in the U.S. Pat. Nos. 2,582,444, 2,850,931, 2,884,826, 1,498,040, 2,580,247, 2,669,896, 2,701,489, 3,102,732, 3,724,299, 4,136,588 and 4,213,355.
The Korean Utility Model Publication No. 84-2675 discloses a socket wrench wherein several socket members are self-contained to enable the user to drive various sizes of bolts or nuts without any requirement for replacement of the socket members. However, the user first selects an appropriate socket member which corresponds to the size of a specific bolt or a nut. And then the user gets the selected socket member displace forward in an axial direction so that higher level of concentrative stresses are created in the course of driving operation since the socket member is utilized in an overhung condition. Also, in order to increase the strength of the socket member to a level enough to withstand those stresses, it is inevitable to increase wall thickness of the socket member and consequently rendering the socket member bulky and heavy. Therefore, this may be raised to a formidable problems in manufacturing and handling the socket wrench.
Further, the Korean Utility Model Publication No. 83-1343 discloses a socket wrench in which separate socket members are supplied independently so that the user may select a specific socket member of desired size and replace it for the previously assembled socket member, whenever it is necessary to drive bolts or nuts of different sizes. However, the socket wrench set forth above requires frequent replacement of the socket depending upon the size of bolts or nuts so that it is inconvenient for the user to handle it. In addition, separate socket members employed in the socket wrench have to be carried. Therefore, it is inconvenient to handle.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a socket wrench including a plurality of socket members slidably assembled in a telescopic manner, an adjustment member for governing the axial movement of the socket members, and a ratchet member for determining the rotational direction of the socket members for eliminating the requirement of separate sockets.
Another object of the present invention is to provide a socket wrench wherein socket members thereof are not overhung outwardly from the body of the socket wrench but overlapped to each other so that the strength of the socket members may not be injured even under the higher concentrative stresses. Thus the socket members can be minimized in thickness with the overall size and height of the socket wrench so that the user may carry conveniently and use the socket wrench.
A further object of the present invention is to provide an improved socket wrench which needs minimum member of elements having simple structures so as to enhance productivity while achieving cost down.
Briefly described, the present invention relates to a socket wrench which includes a body, a plurality of socket members telescopically assembled into the body, the socket members being movable in an upward or downward direction, an adjustment member mounted onto the body for adjusting the up-down movement of the socket members, and a ratchet member for controlling the rotational direction of the socket members relative to the body, whereby rapid selection of one of the socket members depending on the size of a specific bolt or nut can be obtained merely by controlling the adjustment member.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a side view of the socket wrench according to the present invention containing cut away portions in order to illustrate the construction of the socket wrench;
FIG 2. is a bottom view of the socket wrench according to the present invention;
FIG. 3 is an exploded perspective view of a second embodiment of the socket wrench according to the present invention
FIG. 4 is a side sectional view of the socket wrench of FIG. 3 according to the present invention;
FIG. 5 is a top plan view of the socket wrench of FIG. 3 according to the present invention showing a top cover removed therefrom;
FIG. 6 is a side sectional view of a third embodiment of the socket wrench assembled by way of employing a bottom cover; and
FIG. 7 is a bottom view of the socket wrench of FIG. 6 showing the bottom cover removed therefrom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, the socket wrench as shown in FIGS. 1 and 2 comprises a body 1 including a handle 1a integrally formed therewith, a recess 1b disposed on one side of the body 1 for securely holding a socket frame 2, and a bottom surface 1c is in the vicinity of the recess 1b for contacting with a knob 3. The socket frame 2 includes a lug 2a centrally disposed at the inner most surfaces thereof. The socket frame 2 also has an aperture 2b formed therethrough for retaining a ball 4 in a such a manner that the ball 4 is urged inwardly by a spring 5 held in the aperture 2b by means of a headless screw 6. A through-hole 2c diametrically opposed to the aperture 2b functions to guide the knob 3.
Within the socket frame 2, a plurality of socket members 7, 8, and 9 of different sizes are slidably assembled in a telescopic manner. Each of the socket members 7, 8, and 9 is provided with flanges 7b, 8b, and 9b at the upper end thereof and the flanges 7b, 8b, and 9b being grooved to provide knob paths 7a, 8a, and 9a. On the circumferential surface of the socket member 7 adjacent to the socket frame 2, an axial groove 7c is formed so that the ball 4 can be seated on the axial groove 7c.
The knob 3 is so calibrated as to indicate the amount of radial movement by its own scale as shown in FIG. 2. Accordingly, the operator can figure out what size of socket member is ready for use. Such knob 3 is designed to slide in a radial inward or outward direction along the way defined by the bottom surface 1c of the body 1, the through hole 2c, and the radial grooves 7a, 8a, and 9a.
Referring to FIG. 3 through FIG. 5, there is shown a second embodiment of the socket wrench in accordance with the present invention. In this embodiment, the socket wrench comprises in combination the body 1 having the handle portion 1a adapted to be gripped by the operator, a plurality of socket members 102, 103, and 104 telescopically assembled to the body 1, the socket members 102, 103, and 104 being slidable in an axial direction, a cover plate 106 releasably attached to the upper most surface of the body 1, the top cover having a guide member 105 mounted on the inner surface thereof, an adjustment member 107 for preventing axial movement of at least one of the socket members 102, 103, and 104, and a ratchet member 108 for restricting the rotational direction of the body 1 relative to the socket member 108.
The body of the socket wrench includes an opening 110 through which a socket member 104 is rotatably inserted as shown in FIG. 3. An annular shoulder 112 is provided on the inner circumference of the opening 110 so that the socket member 104 can be seated on the shoulder 112 at its toothed portion 143. The body 1 further includes a recessed surface 111 having a pair of threaded holes 113 and 114 and a pair of pin holes 115 and 116 (FIG. 3).
As shown in FIG. 3, the socket members 102, 103, and 104 are so shaped and sized that they can be telescopically and slidably assembled one another. The smallest and intermediate socket members 102 and 104 include internal splines 122 and 132 disposed on their inner circumferences and external splines 123 and 133 disposed on their outer circumferences with stopper rims 121 and 131 disposed at one end of the respective socket members. The largest socket member 104 is provided with an internal spline 140 extending along a limited length of the inner circumference. The largest socket member 104 has a first shoulder 141 which can come into abutment with a stopper rim 131 and a second shoulder 142 on which a guide plate 105 is mounted to define a cavity within the socket member 104. A plurality of teeth 143 are disposed on the outer circumference of the socket member , which extend along a relatively short length. Each of the socket members 102, 103, and 104 are assembled into the body 1 of the wrench in the order of their size.
The guide plate 105 having a circular configuration is fixedly attached on one side of a cover plate 106. The guide plate 105 includes a rectangular lug 150 for fitting into the aperture 161 of the cover plate 106, a circular hole 151 sized to accommodate the adjustment member 107, and a groove 153 disposed between the rectangular lug 150 and the circular hole 151 for receiving an omega shaped spring 152 disposed therein. Such type of guide plate 105 is adapted to be seated on the second shoulder 142 of the largest socket member 104.
The cover plate 106 includes a first hole 160 into which the adjustment member 107 is rotatably inserted at its axle, a rectangular aperture 161 receiving the rectangular lug 150 of the guide plate 105, a pair of counter-sinked holes 162 and 163 through which screws 167 and 168 are threadably fixed to the body 1 of the wrench, a second hole 164 accommodating a portion of the ratchet member 108, and a pair of stopper pins 165 and 166.
The adjustment member 107 comprises in combination an actuation lever 170 and an adjustment knob 171. The actuation lever 170 includes an elongated leg 172 having a crescent shaped cross section, a cylindrical portion 173 having a number of axial groove 173a spaced apart circumferentially thereof, an upper axle 174 extending in an opposite direction relative to the leg 172. On the other hand, the adjustment knob 171 is provided with a protrusion extending across the upper surface of the knob 171. In their assembled position, the cylindrical portion 173 is inserted into the circular hole 151 of the guide plate 104 in a rotatable manner, the central axle 174 being rotatably held in the first hole 160 of the cover plate 106 with the upper end fixedly secured to the adjustment nob 171.
As shown in FIGS. 3, 4, and the free end of the elongated leg 172 moves on the upper surfaces of the socket members 102 and 103 and on the first shoulder 141 of the largest socket member 104 when the adjustment knob 171 is rotated by the operator. The omega shaped spring 152 is selectively engaged with one of the axial grooves 173a disposed at the central portion 152a thereof. Accordingly, the angular position of the elongated leg 172 is readily selected by the combined action of the spring 152 and axial grooves 173a.
The ratchet member 108 comprises a pair of pawls 180 and 181 pivotably held in the pin holes 115 and 116 respectively, a cam 182 rotatably inserted into the second hole 164 of the cover plate 106 and disposed between the pair of pawls 180 and 181, and a selection knob 183 which is placed on the exterior surface of the cover plate 106 and fixedly secured to the upper end of the cam 182. Each of the pawls 180 and 181 is baised toward each other by the respective compression springs 184 and 185. The cam 182 has a camming surface 186 which compresses either one of the pawls 180 and 181 and a central axle 187 pivoted to the cover plate 106. When the cam 182 rotates about its central axle 187 in the opposite direction by the actuation of the selection knob 183, the camming surface 186 can overcome the force exerted by the spring and compress either one of the pawls 180 and 181 so that the compressed pawl can be disengaged from the teeth 143 of the largest socket member 104, thereby determining the rotational direction of the wrench. Moreover, the selection knob 183 has a hole 188 for receiving the central axle 187 of the cam 182.
Referring to FIGS. 6 and 7, there is shown the third embodiment of the socket wrench wherein a body 1', of the socket wrench is opened at the lower surface thereof and a lower cover plate 109 is secured to the lower surface. In this embodiment, the socket members 102, 103, and 104, the adjustment member 107, and the ratchet member 108 are substantially identical in their configuration with those of the preceding embodiments.
The body 1', of the socket wrench consists of a handle portion 1a and a cavity 111' provided to accommodate the socket members 104 and the ratchet member 108. The body 1' further includes a guide wall 117 adapted to rotatably position the largest socket member 104, a circular recess 118 for receiving the adjustment member 107 in a rotatable condition, a first hole 118a through which the axle of the adjustment member 107 is inserted, a second hole 119 for journalling the central axle 187 of the cam, and a pair of pin holes 115' and 116' pivotally receiving the ratchet pawls. On the lower surface of the body 1', a shoulder 110' having a pair of threaded holes 113', and 114' is provided to allow a lower cover plate 109 to be seated thereon. The selection knob 183 of the ratchet member 108 is confined in the recess 112' to be able to carry out a limited range of angular movement.
The lower cover plate 109 is elliptically configured to be seated on the shoulder 110' of the body 1' and has a pair of holes 190 and 191 through which screws 192 and 193 can be inserted to mount the cover plate 109 on the body 1'. A larger aperture 194 is formed through the cover plate 109 to permit the socket members 104 to be inserted in a rotatable manner. In order to make an assembly, the socket members 102, 103, and 104, the adjustment member 107, and the ratchet member 108 are first assembled into the body 1'. After then the lower cover plate 109 is secured to the shoulder 110'.
The socket wrench in accordance with the present invention operates as follows:
When the operator intends to drive a bolt or a nut having a predetermined size by use of the socket wrench illustrated in FIG. 1 and 2, he has to displace the calibrated nob 3 to a position matching the size of the bolt or the nut and then locate the socket wrench on the bolt or the nut while maintaining the socket members 7, 8, and 9 in alignment with the bolt or the nut to be driven. By pressing the wrench against the bolt or the nut with a minor force, the socket members 7, 8, and 9 having smaller size than the bolt or the nut are displaced slidably and rearwardly. Therefore, the bolt or the nut can be inserted into one of the socket members 7, 8, and 9 as selected. When the driving operation is completed, the socket wrench is disengaged from the bolt or the nut, in response to which those socket members 7, 8, and 9 retreated by the bolt or the nut is reinstated due to the gravitational weight of the socket members 7, 8, and 9. The operation can be performed repeatedly to drive a variety of bolts or nuts.
In case where the socket frame 2 is in use, the knob 3 has to be radially outwardly pulled to its rearmost position. By placing the socket wrench onto and pressing it against the bolt or the nut with a minor force, the socket member 7 slides upwardly together with other socket members 8 and 9. The ball 4 engaged with the long groove 7c permits axial movement of the socket member 7 for preventing rotational movement thereof. Once the bolt or the nut is inserted into the socket frame 2, then it can be driven by the socket wrench.
When the driving operation is to be carried out by means of the socket wrench shown in FIG. 3 through FIG. 5 or in FIG. 6 or FIG. 7, the operator has to rotate the nob 171 of the adjustment member 107 to select a specific one of the socket members 102, 103, and 104 which is matching the size of the bolt or the nut to be driven.
More specifically, as shown in FIG. 5, the bottom surface of the elongated leg 172 can selectively traverses the upper surfaces of the socket members 102, 103, and 104 between three positions, i.e., the first position where the socket members 102 and 103 are axially locked so as to drive the smallest bolt or nut, the second position where only the socket member 102 is upwardly displaced so as to drive the bolt or nut having medium size, and the third position where both of the socket members 102 and 103 is upwardly displaced so as to drive the largest bolt or nut. In the course of rotating, the adjustment knob 171 to the positions set forth above, the spring 152 is selectively engaged with the axial groove 173a of the adjustment member 107 at its central portion 152a. It enables for the operator to perceive the selected socket member. Alternatively, the angular position of the knob 171 can be provided on the cover plate 106 or the body 1'. The selection knob 183 of the ratchet member 108 can be rotated in the opposite directions to restrict the rotational direction of the socket member 104.
When the knob 183 is rotated to a specific direction, the camming surface of the cam 182 compresses either one of the pawls 180 and 181 to cause it to be disengaged from the teeth 143 of the socket member 104, thereby making the socket member to rotate in a unilateral direction as selected.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included in the scope of the following claims.
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A socket wrench which includes a body, a plurality of socket members telescopically assembled into the body, the socket members being movable in an upward or downward direction, an adjustment member mounted onto the body for adjusting the up-down movement of the socket members, and a ratchet member for controlling the rotational direction of the socket members relative to the body, whereby rapid selection of one of the socket members depending on the size of a specific bolt or nut can be obtained merely by controlling the adjustment member.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a shutter for opening and closing an aperture or an entrance of a housing. More particularly, it relates to guide rails for holding both end portions of a shutter panel slidably.
[0003] 1. Disclosure of the Prior Art
[0004] A shutter of this kind is generally comprised of a shutter panel in which a plurality of slats is aligned in a mutually bendable manner and guide rails for holding both end portions thereof in a freely sliding manner.
[0005] The guide rails are usually U-shaped members having a U-shaped groove for accommodating the both end portions of the shutter panel therein, and in case an aperture formed at a front surface and an upper surface of the housing successively is to be closed by the shutter panel, the linear U-shaped members are partially bent in order to form guide rails that are curved in extending from the front surface to the upper surface of the aperture and are fixed to a fixing portions of the aperture by screwing.
[0006] In this prior art, since fixing of the guide rails to the fixing portions is achieved by screwing from inner sides of the groove of the U-shaped members, head portions of mounting screws may be exposed to the inner sides of the groove and is apt to be a hindrance in performing smooth sliding of both end portions of the shutter panel.
[0007] At a curved portion that is formed by bending the members, intervals of the U-shaped sections, that is, widths of groove for holding both end portions of the shutter panel, will become narrow and result in a larger resistance at the time of sliding, and it will accordingly be necessary to preliminarily set the widths of the groove to be large in view of portions that become narrow through bending.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to enable smooth sliding of both end portions of a shutter panel within guide rails of a shutter in which the shutter panel is composed of plural slats connected mutually in a freely bending condition and a pair of guide rails including curved portions hold the both end portions of the shutter panel slidably.
[0009] The shutter according to the present invention, which has been made for achieving the above objects, is characterized in that each of the guide rails includes straight members comprised of parallel tie plates and interval plate for connecting central portions of the tie plates mutually for having a H-shaped section, and corner members comprising curved plates respectively succeeding to the tie plates of the straight members, and the both end portions of the shutter panel are inserted between inner half portions of the tie plates partitioned by the interval plate slidably, and outer half portions of the tie plates are mounted to a fixing portions.
[0010] Each of the tie plates is partitioned into an inner half portion and an outer half portion by the interval plate.
[0011] Since the guide rails are fixed to the fixing portions via the outer half portions of the tie plates, no fixing members such as mounting screws will be exposed to the inner half portions for holding both end potions of the shutter panel in a freely sliding manner. Moreover, since curved portions of the guide rails are comprised of corner members that have been preliminarily shaped into curved conditions, intervals between respective curved plates will not be deformed as it is the case with an arrangement in which straight members are bent to form the curved portions. So the intervals may be set to appropriate values. Thus, the intervals between the tie plates in the inner half portions receiving the both end portions of the shutter panel slidably may be made uniform all over the guide rails.
[0012] The corner members may be shaped to be of H-shaped sections similar to the straight members or may alternatively be comprised of a pair of curved plates only.
[0013] Because of the above arrangement, the present invention exhibits the following unique effects.
[0014] The intervals of the inner half portions of the guide rails for holding both end portions of the shutter panel in a freely sliding manner may be made uniform all over the guide rails, and fixing members such as heads of mounting screws can be prevented from being exposed to inside of the inner half portions, whereby the shutter panel may slide smoothly.
[0015] Other objects, features, aspects and advantages of the invention will become more apparent from the following detailed description of embodiments with reference to the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a view showing an external appearance of one example for using the shutter.
[0017] [0017]FIG. 2 is a detailed view of a shutter panel.
[0018] [0018]FIG. 3 is an exploded perspective view of hinge members.
[0019] [0019]FIG. 4 is a detailed view illustrating a relationship between slats and the hinge members.
[0020] [0020]FIG. 5 is a partial perspective view of connecting portions of guide rails.
[0021] [0021]FIG. 6 is a partial sectional view of connecting portions and mounting portions of the guide rails.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Embodiments of the present invention will now be explained in accordance with the drawings.
[0023] The embodiment as illustrated in FIGS. 1 and 2 relates to a shutter comprised of an shutter panel ( 10 ) for opening and closing an aperture formed to extend from a front surface to an upper surface of a housing ( 30 ) that serves as a processing room for machine tools and of a pair of guide rails ( 28 ) for holding the shutter plate ( 10 ) slidably.
[0024] The pair of guide rails ( 28 ) is mounted to a frame body ( 32 ), which is provided along the aperture of the housing ( 30 ), in a mutually opposite condition, and the shutter panel ( 10 ) that is to be further described later is held between the guide rails ( 28 ) in a freely sliding manner.
[0025] The shutter panel ( 10 ) is comprised of laterally elongated slats ( 12 ), hinge members ( 14 ) for connecting respective edges of longer sides of the slats ( 12 ) in a freely bendable manner, and inner link plates ( 13 ) and outer link plates ( 15 ) for connecting respectively adjoining hinge members ( 14 ). Each hinge member ( 14 ) is comprised of an outer tube ( 16 a ) and an inner tube ( 16 b ) having C-shaped sections that are mounted along edges of longer sides of the slats ( 12 ).
[0026] As illustrated in FIGS. 3 and 4, the outer tube ( 16 a ) is arranged in that it is outwardly fitted to the inner tube ( 16 b ) rotatably, and the outer tube ( 16 a ) and the inner tube ( 16 b ) are respectively provided with holding portions ( 18 ) for inserting the edges of the slats ( 12 ) therein and holding these thereby.
[0027] Each holding portion ( 18 ) mentioned above is comprised of a pair of holding pieces that are formed to project in a parallel manner along longer sides of the outer tube ( 16 a ) or the inner tube ( 16 b ), wherein opposing inner surfaces of the holding pieces are formed with engaging protrusions ( 20 ). Thus, by forcing the edge portions of the slats ( 12 ) having a specified thickness between the respective holding pieces, the edges of the slats ( 12 ) will be engaged and held by the engaging protrusions ( 20 ) to prevent slipping off therefrom.
[0028] Since a formed region of the holding portions ( 18 ) and opened region of the C-shaped section of the outer tube ( 16 a ) are respectively set to be of a specified range, the outer tube ( 16 a ) and the inner tube ( 16 b ) are respectively allowed to rotate around a certain angle. Accordingly, adjoining slats ( 12 ) are respectively connected by the hinge members ( 14 ) to be freely bendable within a range defined by the certain angle.
[0029] The outer tubes ( 16 a ) are further formed to project outward from both end of the slats ( 12 ) by a specified length such that projecting portions ( 160 ) of adjoining outer tubes ( 16 a ) will be respectively pierced into a pair of through holes formed on both end portions of the inner and outer link plates ( 13 ) and ( 15 ) so as to hold the inner and outer link plates ( 13 ) and ( 15 ) to be freely rotating along shorter sides of the slats ( 12 ). With this arrangement, the intervals between adjoining outer tubes ( 16 a ) will be maintained constantly by the inner and outer link plates ( 13 ) and ( 15 ) and prevented from separating.
[0030] As illustrated in FIGS. 5 and 6, the guide rails ( 28 ) are comprised of straight members ( 38 ) having a H-shaped section including a pair of parallel tie plates ( 24 ) and interval plates ( 26 ) for respectively connecting central portions of the tie plates ( 24 ), and of corner members ( 40 ) including a pair of parallel curved plates ( 22 ) formed to be concentric with the curved portions of the guide rails ( 28 ), and by connecting respective connecting end surfaces of the straight members ( 38 ) and the corner members ( 40 ) in an alternately abutting manner, it is possible to form the guide rails ( 28 ) with specified curved portions.
[0031] Ribs ( 43 ) which are similar to the interval plates ( 26 ) in width are formed to project from central portions of opposing inner surfaces of the pair of curved plates ( 22 ) so as to be succeeding to the interval plates ( 26 ) when abutted against the straight members ( 38 ).
[0032] As illustrated in FIG. 5, the tie plates ( 24 ) and curved plates ( 22 ) are connected by attaching plates ( 42 ) that are attached so as to cover with connecting portions thereof on outer peripheral surface sides when the tie plates ( 24 ) are abutted against the curved plates ( 22 ).
[0033] The attaching plates ( 42 ) are formed with positioning protrusions ( 421 ) in a projecting manner that are fitted into positioning holes ( 242 ) formed on inner half portions ( 241 ) between the respective tie plates ( 24 ), and are further formed with screw holes to screwing to the frame body ( 32 ) together with the outer half portions ( 243 ) between tie plates ( 24 ). The connecting portions between the tie plates ( 24 ) and the curved plates ( 22 ) on inner peripheral surface sides thereof may be connected in a similar manner.
[0034] As illustrated in FIG. 5, the guide rails ( 28 ) are fixed at their respective portions succeeding to the connecting portions between the straight members ( 38 ) and the corner members ( 40 ) provided by the attaching plates ( 42 ) to the aperture of the housing ( 30 ) such that the outer half portions ( 243 ) of the tie plates ( 24 ) and the outer portions of the curved plates ( 22 ) succeeding thereto are respectively fastened to the frame body ( 32 ) through screwing by mounting screws ( 36 ).
[0035] At this time, the intervals between the respective tie plates ( 24 ) of the straight members ( 38 ) and the intervals between the respective curved plates ( 22 ) of the corner members ( 40 ) are set to be intervals that suit the projecting portions ( 160 ) of the shutter panel ( 10 ) that is held thereby slidably.
[0036] In case the shutter panel ( 10 ) is attached to the guide rails ( 28 ) before mounting them to the frame body ( 32 ), the shutter may be mounted to the aperture to be freely openable or closable simultaneously with completing mounting of the guide rails ( 28 )
[0037] The shutter according to the present example may be opened and closed by holding both end portions of the shutter panel ( 10 ), that is, the projecting portions ( 160 ) of the outer tubes ( 16 a ), into the inner half portions formed between the respective tie plates ( 24 ) and the respective curved plated portions ( 22 ).
[0038] At this time, the respective widths of groove portions along which the projecting portions ( 160 ) slide are preliminarily set to be suitable values at the time of forming the straight members ( 38 ) and the corner members ( 40 ), and since the width is maintained constant all over the guide rails ( 28 )( 28 ), sliding of the shutter panel ( 10 ) may be performed smoothly.
[0039] Since the corner members ( 40 ) of this example are particularly arranged in that a pair of curved plates ( 22 ), which are not connected with each other, are provided in a concentric manner, the intervals between the respective curved plates ( 22 ) can be set to be of appropriate values by respectively forming and setting the curvatures for the outer curved plate portion ( 22 ) and the inner curved portion ( 22 ) to be of specified values. Accordingly non-uniformities are hardly generated in the intervals between the respective curved plates ( 22 ) as it was likely to occur in the prior art when the curved portions were formed by bending a U-shaped member. It is further easier to set and maintain the intervals between the curved plates ( 22 ) when compared to a case in which they are formed to be of H-shaped section similar to the straight members ( 38 ).
[0040] By connecting the straight members ( 38 ) and the corner members ( 40 ) by using attaching plates ( 42 ), since the mounting screws ( 36 ) for fixing the guide rails ( 28 ) will be disposed at positions that are remote from the inner half portions body portions for holding the shutter panel ( 10 ), fixing members such as mounting screws ( 36 ) will not hinder sliding movements of the shutter panel ( 10 ).
[0041] Since a pair of ribs ( 43 ) succeeding from the tie plates ( 24 ) is formed so as to project from opposing inner surfaces of the pair of curved plates ( 22 ) and the end portions of projecting portions ( 160 ) of the outer tubes ( 16 a) are supported by the ribs ( 43 ), they are not swung in lateral directions at the curved portions and not moved into the outer half portions. Therefore, there is no fear that the shutter panel ( 10 ) cannot be slide smoothly.
[0042] While the corner members ( 40 ) are comprised of a pair of curved plates ( 22 ) that are not connected with each other in this example, it is alternatively possible to ensure smoothness in sliding movements of the shutter panel ( 10 ) by employing corner members ( 40 ) with a H-shaped section similar to the straight members ( 38 ) in which respective curved plates ( 22 ) are connected by the interval plates ( 26 ) to assume a specified curvature.
[0043] The method for mounting the guide rails ( 28 ) to the frame body ( 32 ) may be a different method of mounting as long as the outer half portions ( 243 ) of the straight members ( 38 ) and the outer portions of the respective curved plates ( 22 ) of the corner members ( 40 ) succeeding thereto are utilized.
[0044] While the hinge members ( 14 ) may be formed of synthetic resin or metal, it is preferable that the slats ( 12 ) be formed of transparent or semi-transparent synthetic resin. In case the slats ( 12 ) are transparent, the interior of the housing ( 30 ) may be seen through from the slat portions ( 12 ) also when the shutter is closed.
[0045] Since the inner and outer link plates ( 13 ) and ( 15 ) are disposed at both end portions of the shutter panel ( 10 ), the slats ( 12 ) can be prevented from slipping off the holding portions ( 18 ) also when employing an arrangement in which the end edges of the slats ( 12 ) are fitted and engaged at the holding portions ( 18 ) of the outer tubes ( 16 a ) and inner tubes ( 16 b ).
[0046] The invention is not limited to the above-described arrangement in which the straight members ( 38 ) and the corner members ( 40 ) are formed as separated members but the straight members ( 38 ) and the corner members ( 40 ) may also be integrally formed. It is also possible to integrally form the attaching plates ( 42 ) with the corner members ( 40 ).
[0047] In case the attaching plates ( 42 ) are integrally formed with the curved plates ( 24 ) of the corner members ( 40 ) through injection molding, easy assembly of the guide rails ( 28 ) is enabled since the attaching plates ( 42 ) are designed to align the outer peripheral side or the inner peripheral side of the outer surface of the straight members ( 38 ) in a positioned condition as described above when the corner members ( 40 ) are disposed in an abutted condition with respect to the straight members ( 38 ).
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A shutter comprising a shutter panel and a pair of guide rails including curved portions and holding both end portions of the shutter panel slidably. Each of the guide rails includes straight members comprised of parallel tie plates and interval plate connecting central portions thereof mutually to have a H-shaped section and corner members comprising curved plates succeeding to said tie plates. The both end portions of the shutter panel are inserted slidably between inner half portions of the tie plates partitioned by the interval plates, and outer half portions of the tie plates are mounted to a fixing portions to thereby enable smooth sliding movement of the shutter panel within the guide rails.
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BACKGROUND
The present invention relates to golf clubs, a method of using golf clubs and to golf training aids and in particular golf training aids for improving a golfers putting stroke and, more particularly, to golf training aids for facilitating correct positioning of a golfers head relative to the golf ball to be struck.
Improvement of a golfer's swing towards a predetermined preferred method is known to improve the directional accuracy and the accuracy of the length of a golf shot. This is particularly so for the putting stroke. However, even though a golfer may be instructed theoretically and practically on how to perform a determined preferred putting stroke, every golfer will perceive these instructions differently and will not be able to experience how a predetermined preferred putting stroke should physically feel.
SUMMARY
It is therefore desirable for there to be means and a method for enabling golfers to physically experience a predetermined preferred putting stroke.
According to the present invention there is provided a golf training aid comprising a pivot member having pendulum attachment means, the pendulum attachment means being raised above the ground by at least one support leg, and a pendulum having pivot member attachment means, for attachment of the pendulum to the pivot member, and a golf club attachment means.
The golf club attachment means is advantageously disposed at, or adjacent to, the distal end of the pendulum.
The club attachment means may comprise an attachment pin.
The golf training aid advantageously further comprises a head position member extending from the pivot member in a substantially opposite direction to which the pendulum extends such that, in use, it provides correct positioning of the user's head.
The pendulum is advantageously extendable in length and is preferably telescopic.
The golf training aid preferably comprise a pivot member base portion mounted on the at least one leg.
The golf training aid preferably comprises a pivot member stem extending between the base portion and the pivot member.
The pivot member stem is preferably movable along its longitudinal axis, relative to the base portion, to thereby adjust the distance between the base portion and the pivot member.
The base portion may comprise an aperture suitable for receiving a portion of the pivot member stem.
The golf training aid preferably comprises three legs, to form a tripod. The, or each, leg is preferably adjustable in length and is preferably hingedly attached to the base portion.
The golf training aid advantageously further comprises a golf club head having pendulum attachment means for attachment of the club head to the pendulum.
The golf training aid may further comprise a golf club shaft suitable for attachment to the golf club head. The golf club shaft may be adjustable in length. An example of such a shaft may be, for example, a telescopic shaft.
Also according to the present invention there is provided a golf club head having attachment means for attaching the head to the above-mentioned golf training aid.
The attachment means may comprise an attachment hole operable to slideably receive the golf club attachment means, of the training aid, therein. The golf club attachment means and the attachment hole may be shaped to cooperably prevent rotational displacement between the golf club attachment means and the golf club head.
The attachment means, disposed in the club head, is advantageously operable as an interchangeable ballast weight.
The golf club head advantageously comprises a ballast weight hole operable to receive the ballast weight.
The ballast weight and the ballast weight hole are advantageously cooperatively operable to prevent rotation displacement therebetween.
The golf club head advantageously comprises an alignment plate and an alignment marker cooperatively operable to provide a line-of-site indicative of an optimum user head position during a putting stroke.
The alignment plate advantageously comprises an alignment aperture.
The golf club head advantageously comprises shaft linkage for attaching a shaft to the club head and operable to pivot an attached shaft relative to the club head in at least one dimension.
The shaft linkage is advantageously operable to pivot an attached shaft relative to the club head in two dimensions.
The shaft linkage advantageously comprises a double ended clevis joint.
Also according to the present invention there is provided a golf club having a club head as described in the preceding paragraphs.
According to a further aspect of the present invention a golf club includes upper and a lower spaced markers, the markers being located at a lower region of the club with the relative orientation of the upper and lower markers which are spaced from each other being arranged to be monitored by a user of the club.
The upper marker may comprise an opening which opening may comprise an aperture.
The lower marker may comprise a mark.
At least one of the markers may be located on the head of the club and both markers may be so located.
According to a further aspect of the present invention a method of using a golf club including an upper marker and a lower, spaced maker with the markers being located at lower region of the club comprises a user swinging the club and the user monitoring the relative positions of the markers.
The user may monitor the relative locations of the markers and attempt to maintain the relative position of the markers constant.
The present invention includes any combination of the herein referred to features
The present invention will now be described in detail with reference to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a golf training aid according to the present invention;
FIG. 2 is a side elevation of the golf training aid of FIG. 1 ;
FIG. 3 is an isometric view of a golf putter head according to the present invention;
FIG. 4 is drawing of the toe-end view of the golf putter head of FIG. 3 ;
FIG. 5 is an isometric view of a ballast weight for use with the golf putter head of FIG. 3 ;
FIG. 6 is a drawing of the rear view of the golf putter head of FIG. 3 , and
FIGS. 7 and 8 are respectively, a view of one embodiment of a golf club guide in a separated and assembled position.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2 , a golf training aid 10 according to the present invention has a hub 12 having a side face 14 , an upper surface 16 and an under face 18 . A pivot member 20 extends outwardly from the side face 14 .
On its peripheral end, the pivot member 20 has a pendulum attachment means 22 which may be in the form of either a pivot pin or a suitable hole for receiving a pivot pin. A pendulum shaft 24 , formed from an elongate member, has on one end pivot member attachment means 26 and on the other end golf club attachment means 28 . The pivot member attachment means 26 may be formed from either a pivot pin or a suitable hole for receiving a pivot pin such that it cooperates with the pendulum attachment means 22 . The golf club attachment means 28 has an attachment pin 30 . The pendulum 24 is mounted on the pivot member 20 such that the end having a golf club attachment means 28 is able to swing in an accurate or arcuate manner. In a preferred embodiment the pendulum is formed from three telescopic members 24 a, 24 b and 24 c such that it is adjustable in length.
A base portion 31 is formed from a plate 32 having three hinges 34 , 36 and 38 spaced apart around the peripheral circumference thereof. Each hinge is connected to a supporting leg 40 , 42 and 44 , respectively. The supporting legs are telescopic such that their length can be extended to raise the height of the base portion 31 and also to spread their distribution on the ground and account for uneven ground surfaces to provide stability. A spirit level (not shown) may also be disposed on the base 31 to enable the training aid to be correctly set up.
A stem 46 extends downwards from the under face 18 of the hub 12 and through a hole in the base portion 31 such that it is able to pass there through under the control of a worm and wheel mechanism 48 . It will be appreciated that other types of mechanism may be used which function to provide control Controlling the worm and wheel mechanism such that the stem 46 moved downwards through the hole in the base portion 31 reduces the height of the pivot member 20 relative to the ground surface. Similarly, controlling the worm and wheel mechanism such that the stem 46 moves in an upwards direction increases the height of the pivot member 20 relative to the ground surface.
An adjustable member 50 extends upwardly in a direction substantially opposite to the direction in which the pendulum extends and has a head position member 52 fixed to its peripheral end. The head adjustable member 50 is angled such as to position the head position member 52 directly above the golf club attachment means 28 and may be adjustable to alter the extent towards and away from a user. The training aid may be operated with or without the adjustable member and the head position member 52 .
A specially adapted golf club head 54 may be detachably attachable to the golf club attachment means 28 such that is fixed in position thereto. The golf club head 54 is attachable to the attachment means at different angles such as to provide different angles of loft on the club head face. The loft may range from approximately 0 to 70°. The golf club head 54 may either have a permanently attached shaft 56 or, alternatively, a shaft which is attachably detachable to the golf club head 54 to form a golf club 58 . The golf club 58 may be used attached to the golf training aid before being detached therefrom to be used on a golf course.
In use, the golf training aid is set up by extending the legs 40 , 42 and 44 to suitable lengths to provide stability. The height of the pivot member 20 is set by adjusting the height of the stem 46 relative to the base 31 , by using the worm and wheel mechanism 48 . The pendulum 24 is then adjusted in length such that the golf club attachment means 28 overlies the practice putting surface 60 without significantly contracting it. A golf club head 54 is attached to the golf club attachment means 28 such that the shaft 56 extends upwardly in a normal position suitable for practising the putting stroke. The golf club head may be a golf club that can be used in normal play in which case, for example, the toe end of the club head may have attachment means that permit the head to be detachably connected to the golf club attachment means 28 . The attachment means on the toe end of the head may be detachable from the head which may allow the club to be more readily used in normal play.
A user grips the golf club 58 in the normal manner before undertaking a putting stroke. In undertaking a putting stroke the club head 54 is guided by the arc which the pendulum determines and draws with the club attachment means 28 . This arc is the predetermined preferred arc for undertaking a correct putting stroke. Accordingly, the user experiences the biomechanical feedback in his own body as to how he should be undertaking a putting stroke and also experiences how it should feel.
Referring to FIGS. 3 to 6 , a preferred golf club putter head 154 comprises a toe 157 , a heel 159 , a front ball-striking surface 160 , a rear portion 162 and a top surface 164 .
The putter head 154 may further comprise shaft linkage 166 for attaching and linking a golf club shaft 156 to the putter head. The shaft linkage 166 has a pivot member 168 fixed to the top surface 164 such that it extends therefrom in a substantially upward direction. The shaft linkage further comprises a double ended clevis joint 170 . The double ended clevis joint 170 is a rectangular tube having a first clevis joint 172 disposed at one end and a second clevis joint 174 disposed the other end.
The first clevis joint 172 has an open end which is orthogonal relative to the open end of the second clevis joint 174 .
The pivot member 168 is disposed within the open end of the first clevis joint 172 and is pivotably attached thereto by means of a pivot pin 176 which extends through the pivot member 168 and the first clevis joint 172 . The pivoting action of the first clevis joint 172 relative to the pivot member 168 may allow the golf club shaft 156 to be pivoted in a forward and backward direction relative the putter head 154 and may thereby allow the angle between the longitudinal axis of the shaft 156 and the plane of the ball-striking surface 160 to be adjusted and fixed at a desired angle—i.e. the loft of the ball-striking surface 160 can be adjusted as desired.
The shaft 156 has a distal end 178 which is disposed within the open end of the second clevis joint 174 and is pivotably attached thereto by means of a pivot pin 180 which extends through the distal end 178 , of the shaft, and the second clevis joint 174 . The pivoting action of the shaft 156 relative to the clevis joint 170 allows the shaft 156 to be pivoted in a direction perpendicular to the direction of pivot between the first clevis joint and the pivot member. The pivoting action provided by the second clevis joint 174 therefore allows the free end (handle) of the shaft to be pivoted in a plane formed between the toe 157 and the heel 159 and thereby allows the angle of the shaft to be adjusted to suit the height and putting style of the user.
Referring more particularly to FIGS. 4 and 6 , the rear portion 162 comprises a shoulder 180 having an upwardly extending surface such as a substantially vertical surface 182 and a surface transverse thereto such as a substantially horizontal surface 184 . Suitably disposed on the surface 184 is a marker 186 and extending outwards such as substantially perpendicularly outwards from the upwardly extending surface 182 in a suitable relationship such as a substantially parallel relationship relative to the horizontal surface 184 is an alignment plate 188 . The alignment plate 188 has an alignment aperture 190 extending therethrough such as to provide a preferred line of sight 192 from the user's eye, through the alignment opening which may comprise an aperture 190 to the marker 186 . The marker 186 may be, for example, a coloured mark or raised or indented portion disposed on the surface 184 . The marker 186 is preferably spaced from the opening 190 .
FIGS. 7 and 8 disclose an alternative form of a marker and guide that may be affixed to a club head such as a putter. In this embodiment an upper marker 290 may include downwardly extending spigots 292 that are arranged to be received in aligned openings 294 in a lower marker 280 possibly by being a friction fit therein. The lower marker includes a recess 295 into which the upper marker may fit.
The upper marker 290 includes an aperture 296 which may have a first markings 298 extending in the direction of the intended swing of the club and may have a second marker 300 at right angles to the first marker. The lower marker may have a first marking 298 A spaced from the upper marking 298 and may have a second marking 300 A at result angles thereto which marker 298 A and 300 A may cross each other.
In use it is desired to attempt to keep the first marking 298 and 298 A aligned with each other as shown in FIG. 8 when swinging the club. It may also be desired to keep the second markers aligned with each other when swinging the club, as shown in FIG. 8 .
In accordance with one embodiment of the invention a club is provided having the opening 190 and the marker or the upper and lower marker 290 and 280 which club may or may not be used with the training aid.
In use, the putter head 154 is adjusted relative to the shaft 156 , to suite the user, using the shaft linkage 166 . The shaft may be adjustable in length such as by comparing telescopic shaft for instance. The user then practices their putting stroke and in doing so maintains the line of sight 192 , such that they are able to see the marker 186 through the alignment aperture 190 at all times during the putting stroke. This, along with the training aid allows the optimum putting stroke to be achieved for greater directional and length accuracy.
Referring to particularly to FIGS. 4 and 5 , a ballast hole 192 is formed in the toe 157 , of the putter head 154 . The hole 192 extends in a direction towards the heel 159 and is shaped to slideably receive and cooperate with a ballast weight 194 (see FIG. 5 ). The hole 192 has a first diameter for receiving the main body of the ballast weight and a second smaller diameter for receiving an extended portion of the ballast weight. The hole 192 has a circumferentially discrete region of increased diameter extending longitudinally along the length of the hole to provide a receiving groove 196 .
The ballast weight 194 provides for adjustable putter weights to suite the user. The ballast weight 194 is a cylinder having an outer diameter which corresponds with the first diameter of the hole 192 , such that the weight 194 is slideably received within the hole 192 . The weight has an inner end 198 and an outer end 200 . The inner end 198 has an extended portion in the form of an alignment projection 202 , which extends in the direction of the longitudinal axis of the weight 194 and is dimensioned to have a diameter which corresponds with the second smaller diameter of the hole. The outer end 200 , of the ballast weight 194 , has an attachment hole 204 extending along the longitudinal axis of the ballast weight 194 . The attachment hole 204 is operable to slideably receive the attachment pin 30 of the golf training aid 10 (see FIGS. 1 and 2 ). The attachment hole 204 is shaped to prevent rotational displacement of the attachment pin 30 relative to the hole 204 . Accordingly, the hole 204 has one or more flat portions, which may be machined, and which cooperate with flat portions disposed on the attachment pin 30 to prevent rotation displacement.
The ballast weight 194 also has a raised portion of increased diameter to form a locking member 206 , which extends along the outer surface of the weight in a direction substantially parallel to the longitudinal direction thereof. The locking member 206 is dimensioned to be slideably receiving in the groove 196 such that when the weight 194 is disposed within the hole 192 the locking member 206 cooperates with the groove 196 to prevent rotational displacement of the weight 194 relative to the hole 192 .
Although the golf training aid, club head and club described above are illustrated in the drawings as suitable for right-handed use, it will be appreciated that the golf training aid, club head and club is equally applicable to left-handed use within the scope of the present invention.
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A user swings a putter head ( 154 ) that is connected to a putter shaft ( 156 ) about a pivot of a pendulum ( 24 ). The putter head includes an opening ( 190 ) and a lower marker ( 186 ) located beneath the opening and spaced from the opening. The user attempts to maintain the marker within the opening ( 190 ) when swinging the club.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to security systems, and more particularly, to security systems for preventing entry through a doorway.
[0002] Locks and deadbolts and combinations thereof are common security measures to control the opening of a door way entrance to a room or a dwelling. However, when these items fail or are rendered useless by an intruder, there is nothing left to prevent the opening of the door and stopping an intruder's entry into the area.
[0003] As can be seen, there is a need for a security device that prevents the opening of a door when locks and deadbolts fail or rendered useless.
SUMMARY OF THE INVENTION
[0004] In one aspect of the present invention, a telescopic security apparatus is provided which has a first tubular member having a yoke attached to a top end thereof; a second tubular member having a foot operatively attached to a bottom end thereof, wherein the first tubular member is telescopically coupled with the first tubular member; a plurality of apertures defined in a first spaced apart relation through an opposed sidewall of the first tubular member; a plurality of cooperating apertures defined in a second spaced apart relation through an opposed sidewall the second tubular member in; and a bolt received through a selected aperture and a selected cooperating aperture. The telescopic security apparatus foot is provided with a frictional surface defined on a lower surface thereof adapted for non-slipping frictional engagement with a floor surface. The bolt may further include a hole extending through a transverse axis thereof. The telescopic security apparatus may also include a retaining pin received in the hole. In a preferred embodiment, the yoke is adapted to substantially surround a shaft of a doorknob.
[0005] Other aspects of the invention included a method of securing a doorway, the method including: 1) providing a telescopic door security bar having a first tubular member having a yoke attached to a top end thereof; a second tubular member having a foot operatively attached to a bottom end thereof, wherein the first tubular member is telescopically coupled with the first tubular member; a plurality of apertures defined in a first spaced apart relation through an opposed sidewall of the first tubular member; a plurality of cooperating apertures defined in a second spaced apart relation through an opposed sidewall the second tubular member in; and a bolt received through a selected aperture and a selected cooperating aperture; 2) positioning the yoke around a shaft of a door knob; 3) positioning the foot in a non-slipping frictional contact with a floor surface. The method may also include providing the foot with a frictional lower surface adapted for non-slipping frictional engagement with the floor surface. The method may also include providing a hole through a transverse axis of the bolt and inserting a retaining pin through the hole. The method may also include adjusting the length of the security bar by inserting the bolt through a different selected aperture and an alternative cooperating aperture.
[0006] These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of the door security bar, shown in use.
[0008] FIG. 2 is a perspective view of the door security bar.
[0009] FIG. 3 is an exploded view of the door security bar.
[0010] FIG. 4 is a section view of the door security bar, taken along line 4 - 4 in FIG. 1 .
[0011] FIG. 5 is a section view of the door security bar, taken along line 5 - 5 in FIG. 4 .
[0012] FIG. 6 is a section view of the door security bar, illustrating the removal of pin 20 and bolt 18 to adjust upper tube 10 .
DETAILED DESCRIPTION OF THE INVENTION
[0013] The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
[0014] Broadly, an embodiment of the present invention provides a telescopic door security bar for preventing intruders from opening doorway and entering a room.
[0015] As best seen in reference to FIG. 1 , a telescoping door security bar includes an elongate bar having an upper tubular member 10 and a lower tubular member 12 in which one tubular member is received within the other tubular member in a telescopic relation. The upper 10 and lower 12 tubular members may be formed of any shaped tube material, round, box, triangular and the like. Preferably the tubular members 10 , 12 are formed of a high strength material such as steel, aluminum, composites, or carbon graphite.
[0016] The upper tubular member 10 has a doorknob yoke 14 operatively attached to a top end of the upper tubular member 10 . The yoke 14 is adapted to surround the shaft of a doorknob 36 which is attached to a door 34 to control the opening of the door 34 into a structure, such as a room of a dwelling.
[0017] The lower tubular member 12 includes a foot 16 operatively attached to a bottom end of the lower tubular member 12 . Preferably, the foot 16 is formed to have a frictional lower face so that it may frictionally engage with a floor surface 38 , such as tile, hardwoods, carpeting, and the like. In a preferred embodiment the frictional surface may include a rubberized surface. In other embodiments, the frictional surface may include a textured surface. In a preferred embodiment the upper tubular member 10 is received within the lower tubular member 12 .
[0018] One or more of apertures 24 are defined through the lower tubular member 12 in a spaced apart relation and substantially perpendicular to a longitudinal axis of the lower tubular member 12 . The upper tubular member 10 may also have one or more cooperating apertures 26 defined through the upper tubular member 10 and are similarly defined in a spaced apart relation and aligned substantially perpendicular to a longitudinal axis of the upper tubular member 10 .
[0019] A bolt or pin 18 is received through the apertures 24 of the lower tubular member 12 and the cooperating apertures 26 of the upper tubular member 10 . The bolt or pin 18 includes a hole 22 defined through a transverse axis of the bolt 18 that is adapted to receive a retaining pin, such as a cotter pin 20 . The length of the door security device may be selectably adjusted by the user selecting the appropriate aperture 24 and cooperating aperture 26 to obtain the desired length of the security device.
[0020] The length of the device is adjustable to accommodate the height of the doorknob 36 with respect to the floor surface 38 . The length of the device is also adjustable to accommodate for the width of a hall way or passage way within the doorway, that may be defined by an interior wall structure, such as an entryway to a home or dwelling. With the telescopic door security bar of the present invention in place, the opening of the door is prevented in the event a lock or deadbolt is rendered inoperative by an intruder.
[0021] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
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A telescoping door security bar for preventing intruders from entering a room. The telescoping door security bar uses a bolt and cotter pin, which are inserted completely through the door security bar to make it more stable.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to a fastening clip bar, comprising a plurality of fastening clips arranged parallel to each other, and an adhesive joining the fastening clips with each other.
2. Description of the Related Art
Fastening clips are U-shaped fastening means with a back and two lateral legs. For instance, they are circular or flat wires bent into the shape of an U. In many cases, the ends of the legs are provided with a chamfered cut, so that the legs can penetrate into an underground more easily. By an asymmetric chamfered cut it can be obtained that the legs run sideways from the original leg axis when they are driven in, by which the resistance against pull-out can be increased.
Fastening clip bars can be produced by cutting single wires from a continuous wire material into length, then bending a plurality of single wires over a shaping body and collecting them, and subsequently gluing together a plurality of fastening clips to a fastening clip bar. This method has become known as “one wire” or “two wires” method. The adhesive is applied to the back of the fastening clips from the outside. Further, a method for producing fastening clip bars is known in which a tape material is provided, which comprises parallel wires aligned in the direction of travel of the tape material, the tape material is divided crosswise to the direction of travel, and the plates are bent to a fastening clip bar. A particularly advantageous realisation of this “plural wires” method is decried in EP 1 331 407 B1.
The fastening clip bars are placed by means of tackers, which may be manually operated, mechanically operated, hydraulically operated, gas-fired or electrically operated tackers. In a tacker, a fastening clip bar is thrust from a magazine into the movement region of a tacking plunger, which is driven in one of the ways described above. The tacking plunger shears offone or plural fastening clips at the same time and drives them through a drive-in channel of a muzzle head into a work piece, against which the tacker is set with the muzzle head.
Self-loading machines have a magazine, which accommodates a plurality of fastening clip bars in the parallel direction. A fastening clip bar is arranged in the supply path to the drive-in channel and is thrust in the direction of the drive-in channel by a spring-biased slide bar. After each drive-in procedure, the slide bar thrusts the rest of the fastening clip bar somewhat forward, until the fastening clip bar is used up. Then, the slide bar is pulled back, and a further fastening clip bar follows on into the supply path. In particular, self-loading machines can be realised as side-loading machines with fastening clip bars arranged laterally side by side or as vertically loading or rear loading machines with fastening clip bars arranged one above the other.
In many usages of self-loading machines, strong shocks are introduced into the magazine. These shocks may have the result that fastening clip bars break. By faulty alignments in the magazine, the broken fastening clip bars can disturb the further loading of fastening clip bars into the supply path and thus they can result in operation troubles.
By way of example, the above problem occurs when fastening clip bars are automatically driven into bedsteads made of wood. Automatic apparatuses are used for this, in which several tackers are arranged on one common support frame. The support frame is moved to and fro between an upper idle position, in which processed bedsteads can be replaced by bedsteads which are to be processed, and a working position, in which the tackers are set against the work pieces. In each movement to and fro, strong shocks act on the magazines. Further on, a strong shock is introduced into the magazine in each driving in procedure, because a piston driving the tacking plunger hits against a stop buffer after a long working stroke, and this causes a strong concussion of the whole tacker. As a result of the concussions, breach of fastening clips in the self-loading magazines often occurs.
BRIEF SUMMARY OF THE INVENTION
Starting from this, the present invention is based on the objective to provide a fastening clip bar whose usage in tackers with self-loading magazines causes fewer troubles in the operation.
The objective is resolved by a fastening clip bar with the features of the claim 1 . Advantageous embodiments of the fastening clip bar are indicated in the subclaims.
The fastening clip bar according to the present invention has a plurality of fastening clips arranged parallel to each other, an adhesive joining the fastening clips with each other, and at least one elastic tape extending over the fastening clips which is glued together with the same.
The present invention starts from the surprising finding that it makes no sense to realise the fastening clip bar such that a breach of the fastening clip bar upon shock stresses in the self-loading magazine is avoided. Such realisations necessitate a sumptuous use of greater amounts of the adhesive, which can negatively affect the placement of the fastening clip bars. To the contrary, the fastening clip bar according to the present invention is purposefully designed such that that it can break under the shocks occurring in self-loading devices. For this purpose, the fastening clips of the fastening clip bar are connected with each other by an elastic tape, which permits the relative movement of parts of the fastening clip bar with respect to each other, which is necessary for a breach of the fastening clip bar. The tape compensates the relative movement through elastic deformation, and is therefore not destroyed in the breach of the fastening clip bar. Subsequently, the tape takes on its original form again and keeps the fragments of the fastening clip bar sufficiently together, so that the fastening clip bars can be recharged into the supply path without blocking the self-loading magazine. Shocks introduced into the self-loading magazine are absorbed by breaking fastening clip bars, so that the breach of further fastening clip bars or damages of the tacker, respectively, can be avoided, which contributes to the prevention of troubles in the operation.
Thus, the fastening clip bar can be advantageously processed by means of self-loading machines, but is not limited to this usage, however. In particular, processing by means of handheld devices and/or not self-loading tackers is also possible.
The adhesive joining the fastening clips can release solvents during the production and the subsequent storage of the fastening clip bar, which can deteriorate the elastic tape. According to an advantageous embodiment of the present invention, the tape is breathable and/or solvent resistant. A breathable tape permits the solvents to penetrate. A solvent resistant tape is not damaged by released solvents.
In principle, the tape can extend over an inner side of the fastening clips. In one embodiment, the tape extends over an outer side of the fastening clips. This is particularly advantageous from the standpoint of the manufacture.
In principle, it may be sufficient that the tape extends over a portion of the fastening clip bar which is particularly prone to breaking. This may be the central region of the fastening clip bar. According to a particularly preferred embodiment, the tape extends over the entire fastening clip bar and is joined with all the fastening clips of the fastening clip bar. Through this it is made sure that a breach of the fastening clip bar at an arbitrary position does not cause any loading jams.
The tape may extend over the legs of the fastening clips. According to an embodiment which is advantageous from the viewpoint of manufacture, the tape extends over the back of the fastening clips.
In principle, even the adhesive can be applied on the inner side of the fastening clips. According to an embodiment which is advantageous from the viewpoint of manufacture, the adhesive is applied to the outer side of the fastening clips.
Further, the present invention incorporates embodiments in which the adhesive is disposed on the legs of the fastening clips. According to an embodiment which is advantageous from the viewpoint of manufacture, the adhesive is applied on the back of the fastening clips.
Embodiments are also incorporated in which the tape and/or the adhesive is/are applied on the back as well as on the legs of the fastening clips.
The tape may be joined with the fastening clips in different ways. In one embodiment, the tape is connected to the fastening clips by means of the adhesive which joins the fastening clips with each other. For this purpose, the tape may be applied in the application and before the curing of the adhesive on the fastening clips. According to a further embodiment, which can be used in addition to or instead of the embodiment described above, the tape is glued together with the fastening clips or with the adhesive applied thereon, respectively, by means of an adhesive film on its lower side which is applied on the fastening clips with the tape. A self-adhesive tape is used in this, which can be applied before or after the curing of the adhesive.
According to a further embodiment, which can be used in addition to or instead of at least one of the embodiments described above, the tape is glued together with the fastening clips or with the adhesive applied thereon, respectively, by means of an adhesive set free from the tape. This embodiment uses the fact that the tape contains an adhesive which is set free in the application on the fastening clips and which produces the connection between tape and fastening clips. By way of example, the release of the adhesive can be caused by heating.
In particular, the fastening clips can be made from a metal or from a plastic material.
According to a further embodiment, a means for reducing the resistance against penetration and/or for gluing the legs to the underground is applied on the legs. The means facilitates the penetration of the legs into the underground and/or contributes to the anchoring of the fastening clips on the underground, so that the drive-in impacts exerted onto the fastening clips can be reduced. As a consequence, breaches of the fastening clip bar occur less frequently, and the risk of loading jams is reduced further.
In particular, the fastening clips can be made from a metal or from a plastic material.
According to a preferred embodiment, the fastening clips are made from a wire.
According to a further preferred embodiment, the legs have a chamfered cut on the ends, by which the impacts necessary for driving in can also be reduced.
The present invention is explained in more detail in the following by means of the attached drawings of an example of its realisation. In the drawings show:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a fastening clip bar in an enlarged side view;
FIG. 2 the same fastening clip bar in an enlarged cross section along the line A-A of FIG. 1 ;
FIG. 3 an enlarged detail X of FIG. 1 ;
FIG. 4 an alternative realisation Y of the detail X of FIG. 1 ;
FIG. 5 the same fastening clip bar in a side view;
FIG. 6 the same fastening clip bar in the top view.
DETAILED DESCRIPTION OF THE INVENTION
According to FIGS. 1 , 5 and 6 , a fastening clip bar 1 consists of a plurality of fastening clips 2 . Each fastening clip 2 has a back 3 with two legs 4 ′, 4 ″ projecting parallel from it and being essentially straight. In the example, the back 3 has a bending radius r, in the view of a specific usage. In the context of other usages, the back 3 can also be executed otherwise, in a straight line in particular.
According to FIG. 2 , each fastening clip is bent from a flat wire.
According to FIG. 3 , the legs 4 ′, 4 ″ each have a chisel made chamfered cut 6 ′, 6 ″ on their free ends, which is symmetrical and has a chisel angle β.
According to FIG. 4 , the legs 4 ′, 4 ″ have a lateral chamfered cut 7 ′, 7 ″ with an angle γ on each of their free ends 5 ′, 5 ′, wherein the chamfered cuts of neighbouring legs 4 ′, 4 ″ of neighbouring fastening clips 2 are chamfered in different directions.
According to FIGS. 5 and 6 , the fastening clips 2 of the fastening clip bar 1 are coated with an adhesive 8 on the back 3 and in the upper region of the legs 4 ′, 4 ″ at the outside. The same is for instance an adhesive which is cured by heating after the application. In the example, the legs 4 ′, 4 ″ are coated with adhesive 8 for about ⅓ of their height, up to the stroke-dotted line.
Further, the legs 4 ′, 4 ″ are each one provided with a lacquer 9 in the lower region at the outer and the inner side, which reduces the resistance against penetration and/or increases the resistance against being pulled out and anchors the legs, when the fastening clips 2 are already driven into the wood. In the example, the legs 4 ′, 4 ″ are coated with the lacquer 9 for about ⅔ of their height.
The fastening clip bar 1 can be manufactured by the one wire, two wires or plural wires method mentioned in the beginning.
Finally, an elastic tape 10 is disposed on the outside on the back 3 and on the part of the legs 4 ′, 4 ″—up to the stroke-dotted line—of the fastening clip bar 1 , which is breathable and/or solvent free in particular.
The elastic tape 10 permits a breach of the fastening clip bar 1 and keeps the fastening clips 2 sufficiently together, so that no loading jam takes place in the self-loading magazine. The elastic tape 10 can be executed to be breathable and solvent resistant. This is preferably the case when a solvent-containing adhesive is used. Then, the elastic tape 10 permits permeation of solvent set free by the adhesive and is not affected by the same.
The tape 10 is attached to the fastening clip bar 1 after the application and before the curing of the adhesive. Adhesive 8 and the tape 10 are matched such that the tape 10 adheres on the fastening clips 2 in the curing of the adhesive 8 .
When driving in, the part of the tape 10 adhering on the driven in fastening clip 2 is sheared off from the fastening clip bar 1 with the fastening clip 2 and remains on the fastening clip 2 .
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A fastening clip bar, comprising a plurality of fastening clips arranged parallel to each other, an adhesive joining the fastening clips with each other, and at least one elastic tape extending over the fastening clips which is glued together with the same.
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FIELD OF THE INVENTION
[0001] The present invention relates to composting of animal manure, poultry manure, and/or sewage sludge from municipal wastewater treatment plants. Specifically, the present invention relates to a method of composting with less time and cost for processing, less land, and a superior form of final product, the final form being a dehydrated pellet or granule approaching 100% dehydrated, composted manure or 100% dehydrated, composted sewage sludge. The high quality dehydrated compost can be used in automated fertilizer spreading machines and common bulk material handling equipment for loading, unloading, storage and transport.
BACKGROUND OF THE INVENTION
[0002] Composting is the aerobic decomposition of manure or other organic materials in a thermophilic temperature range (about 40-65° C.). Composting improves the handling characteristics of organic residues by reducing their volume and weight. Composting also converts organic material to a stable material that is not harmful to soil, plants, or crops. Some of the disadvantages of composting organic residues include time for processing, cost for handling equipment, and available land for composting.
[0003] Water content is an important factor influencing the rate and efficiency of composting. Moisture content between about 40% and 60% is a useful target range, with moisture needed for microbial activity. Water is required to allow chemical reactions to proceed, as well as to transport nutrients and allow microorganisms to move within the compost window. However, excessive moisture inhibits gas exchange, slowing down decomposition, and possibly resulting in anaerobic conditions; when moisture levels are too low, microbial activity is less rapid.
[0004] Some homogeneous organic materials can be composted alone without mixing with bulk materials. However, very wet raw materials, particularly animal manure and sewage sludge, need to have the moisture reduced to below about 60% before composting. The moisture content for materials entering most industrial dryers should be less than about 50%, and preferably in the range of about 20-30% moisture. Direct drying of very wet material is not practical; instead of drying, a dry bulking material is added in conventional composting, in order to absorb moisture until the ideal moisture target, about 40-60% moisture, is achieved. Bulking agents provide structural support when manure solids, or other organic residues, are too wet to maintain air spaces within the composting pile. Dry and fibrous materials, such as sawdust, leaves, finely chopped straw or peat moss, are good bulking agents for composting wet manure or organic residues.
[0005] U.S. Pat. No. 3,905,796 (the '796 patent) teaches a process for dehydrating manure-based fertilizers where a homogenous and durable pulp is granulated and dried. The '796 patent notes that manure undergoes a first fermentation in the course of storage, but does not describe the extent of fermentation or the method (time, temperature, moisture, passive or active turning of the material, etc.). The '796 patent describes mixing of pre-dried material with wet material in order to prepare for granulation.
[0006] U.S. Pat. No. 4,082,532 discloses a process for manufacturing extruded cattle manure pellets where the cattle manure is mixed into a pulp and contains moisture content between 50 to 55% by weight. The material is extruded to form strands, which are subsequently dried in a fluidized bed. The dried manure pellets are not fermented. The organic products in manure have to be converted to inorganic form before they can be used as organic fertilizer. Dried manure products that are not fermented are potentially harmful to growing plants or crops.
[0007] U.S. Pat. No. 6,372,007 (the '007 patent) describes a general process for making compost from bovine manure, where additional ingredients are added to make a complete, balanced organic fertilizer. The '007 patent describes the fermentation process as a traditional composting process where bovine manure is spread on the ground and turned. After fermentation, the manure is air dried by spreading. Any fermentation and drying process using land spreading and air drying requires a large land area, extensive handling, and is very time-consuming.
[0008] U.S. Pat. No. 6,648,940 (the '940 patent) describes a process for producing compost by adding seed bacteria to accelerate the process. Yagihashi's process is specific for processing organic waste materials from food processing factories, including spent grains from beer factories, fish cake from fish processing factories, and soybean pulp from bean curd production, where water content ranges from 55-70%. The addition of seed bacteria reduces the fermentation processing time from several months to thirty days. The effectiveness of the process depends upon highly regulated moisture control (60%) and oxygen concentration in the compost at 15-21%.
SUMMARY OF THE INVENTION
[0009] The present invention improves upon conventional composting by adding a dryer to the system to evaporate moisture. In the high efficiency composting process of the present invention, recycled, dehydrated compost material replaces the bulking agent to adjust the moisture of material entering the fermentation vessel (fermentor). The invention results in a substantial volume reduction of the fermentor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a flowchart diagram of an exemplary process of the present invention;
[0011] FIG. 2 is a flowchart diagram of a conventional fermentor;
[0012] FIG. 3 is an additional flowchart diagram of the high efficiency composting process of the present invention;
[0013] FIG. 4 is a flowchart diagram of a conventional continuous fermentor modeled with biomass conversion and evaporation losses; and
[0014] FIG. 5 is a flowchart diagram of the high efficiency composting process of the present invention, modeled with biomass conversion and evaporation losses.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The fermentor operating conditions for the high efficiency composting process of the present invention are similar to conventional composting. The moisture of the material entering the fermentor is adjusted to approximately 40% to 60%, and the operating temperature of the fermentor is about 40-65° C., which is in the thermophilic range.
[0016] An additional advantage of the high efficiency composting process of the present invention is that the dehydrated, fermented material can be formed into a pellet or granule by any method known in the art. Dehydrated pellets or granules can be used in automated fertilizer spreading machines and common bulk material handling equipment for loading, unloading, storage and transport.
[0017] In comparing the relative size of a conventional composting fermentor with the size of a fermentor using the high efficiency composting process for composting 100 tons/day of raw manure ( FIG. 2 ), for the conventional composting fermentor, the feed is 100 tons/day of raw manure at 90% moisture. One hundred tons/day of bulking agent (e.g., sawdust) at 10% moisture is added so that the fermentor has 50% moisture. Assuming that the density is one ton/m 3 , the fermentor volume is 12,000 m 3 , for a compost time of 60 days. The average residence time for solids in the fermentor=(Solids in the fermentor)/(Solids exiting the system)=(12,000 m 3 *1 m 3 /ton*50%)/(200 tons/day*50%)=(12,000*0.5)/(200*0.5)=60 days.
[0018] Referring to FIG. 3 , for the high efficiency composting process of the present invention, the feed is the same at 100 tons/day of raw manure at 90% moisture. Instead of bulking agent, one hundred tons/day of recycled, dehydrated manure at 10% moisture is added, so that the fermentor has 50% moisture. The recycled, dehydrated pig manure is product exiting the dryer. Assuming that the density is one ton/m 3 , the fermentor volume is 1,200 m 3 , for a compost time of 60 days. The average residence time for solids in the fermentor=(Solids in the fermentor)/(Solids exiting the system)=(1,200 m 3 *1 m 3 /ton*50%)/(11 tons/day*90%)=(1,200*0.5)/(11*0.9)=60 days.
[0019] The relative size of the fermentors=(12,000 m 3 )/(1,200 m 3 )=10:1. Thus, the conventional fermentor is 10 times the volume of the fermentor using the high efficiency composting process of the present invention. In terms of loss of solids (microbiological degradation of organic carbon to CO 2 ) and evaporative moisture loss, the relative volume ratio is even more favorable for the high efficiency composting process of the present invention.
[0020] Referring to FIG. 4 , for the conventional composting fermentor, the feedstock is 100 tons/day of raw manure at 90% moisture. One hundred tons/day of bulling agent (e.g., sawdust) at 10% moisture is added so that the material entering the fermentor has 50% moisture. Assuming that the density is one ton/m 3 , the moisture loss is 5% of the incoming moisture (or 5 tons/day), and the bioconversion of organic carbon to CO 2 is 40% of the incoming manure solids (or 4 tons/day), the fermentor volume is 11,450 m 3 , for a compost time of 60 days. The average residence time for solids in the fermentor=(Solids in the fermentor)/(Solids exiting the system)=(11,450 m 3 *1 m 3 /ton*50.3%)/(191 tons/day*50.3%)=(11,450*0.503)/(191*0.503)=60 days.
[0021] Referring to FIG. 5 , for the composting fermentor using the process of the present invention, the feedstock is the same at 100 tons/day of raw manure at 90% moisture. Instead of bulring agent, one hundred tons/day of recycled dehydrated pig manure at 10% moisture is added, so that material entering the fermentor has 50% moisture. The recycled, dehydrated manure is product exiting the dryer. Assuming that the density is one ton/m 3 , the moisture loss is 5% of the incoming moisture (or 5 tons/day), and the bioconversion of organic carbon to CO 2 is 40% of the incoming manure solids (or 4 tons/day), the fermentor volume is 716 m 3 , for a compost time of 60 days. The average residence time for solids in the fermentor=(Solids in the fermentor)/(Solids Exiting the system)=(716 m 3 *1 m 3 /ton*50.3%)/(6.67 tons/day*90%)=(716*0.503)/(6.67*0.9)=60 days.
[0022] Note that the fermentor in the process of the present invention is an order of magnitude smaller than a fermentor in a conventional composting process that requires addition of a bulking agent. The final product produced by the process of the present invention eliminates the problems associated with the cost of transportation of a humid material as well as problems of handling, storage and labor. In addition, the final product produced by the process of the present invention is a dehydrated pellet or granule that can be used in automated fertilizer spreading machines and common bulk material handling equipment for loading, unloading, storage and transport.
[0023] The final product produced by the process of the present invention is virtually 100% pure raw material that has been fermented and dehydrated. Pure, 100% composted livestock manure has more economic value than composted products that have been mixed with bulking agents (that is, compost made with less than 100% livestock manure).
[0024] While the present invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of the invention will be obvious to those skilled in the art. The appended claims and the present invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
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The present invention improves upon conventional composting by adding a dryer to the system to evaporate moisture. In the high efficiency composting process of the present invention, recycled, dehydrated compost material replaces the bulking agent to adjust the moisture of material entering the fermentor. The invention results in a substantial volume reduction of the fermentor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 10/362,105, filed Oct. 1, 2003, which claims the priority of PCT Application No. PCT/GB01/03784 filed Aug. 22, 2001 and British applications GB 0020737.3 filed Aug. 22, 2000 and GB 0110779.6 filed May 2, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method of an apparatus for communicating user related information using a wireless information device. The term ‘wireless information device’ used in this patent specification should be expansively construed to cover any kind of device with one or two way communications capabilities and includes without limitation radio telephones, smart phones, communicators, personal computers, computers and application specific devices. It includes devices able to communicate in any manner over any kind of network, such as GSM or UMTS mobile radio, Bluetooth, Internet etc.
2. Description of the Prior Art
Current generation wired and wireless telephones can indicate to a caller the status of a call recipient in only crude and potentially ambiguous terms: for example, when a caller makes a voice call, he or she might receive one of five different responses: (a) the desired call recipient answers; (b) there is no answer; (c) there is an engaged tone; (d) the call gets put through to a pre-recorded voice mail message or (e) the call gets diverted to someone else. If the intended call recipient does not actually answer the call, then the caller has no idea why the call was not answered: for example, is the intended recipient in fact there but too busy to answer? Could a different number have been dialed to connect successfully?
Conventional so-called ‘Presence’ systems are the subject of considerable interest at present and partly solve the above problems. The intent of Presence systems is to show the status of the prospective call recipient to a calling party—for example, giving information about whether the intended call recipient is busy, in a meeting, contactable on a mobile phone or land line etc. Reference may be made to RFC 2778 ‘A Model for Presence and Instant Messaging’ February 2000, The Internet Society. Prior art Presence systems have not however been extended to cover the idea of the calling party indicating its own status, such as the subject of the intended call or its urgency.
Reference may also be made to conventional Instant Messaging (IM) systems, which allow a party able to participate in IM to indicate its status by selecting a pre-defined status flag (e.g. Out to Lunch; On-line etc.) Because these status flags show merely the status of a party, they are aimed at informing a party wishing to message that party whether doing so would be appropriate, and are therefore similar to the conventional telephony Presence systems described above.
Hence, both prior art IM and Presence systems share a presumption that the critical information to convey, prior to the main communication commencing, relates to the status of the entity which is the target of communications (e.g. whether they are reachable and if so how). This is an essentially asymmetric weighting of significance and ignores entirely the possibility that the person seeking to initiate communication (e.g. commence a voice call) can also provide the target (the call recipient) with useful information prior to the main communication commencing. Caller ID systems partly address this: they enable a called party to see the telephone number of the person calling. Caller ID systems are increasingly popular, since knowing the identity of the caller can be very pertinent to a decision to accept a call or not. Where the called party's device can store a database of numbers, the caller ID information can be matched against database entries, so that the called party's device can display the actual name of the person calling. At the most basic level, mobile telephone users use the caller ID to screen their calls so that, based on a number of factors relating to themselves (i.e. location, current activity etc.), they can look at the caller ID and make a number of assumptions about the identity of the caller and then take a decision regarding answering the call. However, users are increasingly feeling compelled to answer calls simply because they know that the mobile telephone is with them no matter where they are. Users are answering the mobile telephone even when it is not convenient for them. They are now trying to take various steps to control the reactive behaviours implicit with owning a mobile phone, despite the availability of Caller ID. For example:
Some buy two mobile telephones; one is for personal use, the other for work. Some are insisting that the phone is turned off outside of work hours. Some simply decide, based on the Caller ID, that if no name is shown with the call—that the call is probably unimportant because they don't recognise the number. Conversely others interpret this same factor as indicating a potential emergency call.
Hence, the inherent limitations of Caller ID seriously restrict its practical utility.
Through the convergence of communications and computing, a new generation of intelligent communications devices, often referred to as smart phones or communicators, is being brought into being, utilising operating systems and related applications such as the Symbian OS platform from Symbian Limited of the United Kingdom. Wireless information devices based on the Symbian OS platform offer the promise of being ‘smarter’ than current generation GSM phones in being able to offer multiple advanced, robust client based applications. However, prior to the present invention, even these advanced wireless information devices would have been no more capable than existing phones in terms of providing rich information about a call to a call recipient prior to the call being answered.
SUMMARY OF THE PRESENT INVENTION
In a first aspect of the invention, there is a method of communicating user related information using a wireless information device in which a caller using a first wireless information device enters into the device information of potential relevance to a call recipient, the information being of a kind which varies;
the method comprising the step of transferring that information to a second wireless information device controlled by the call recipient, such that the call recipient is automatically provided with the information prior to accepting or answering a voice call from the caller.
The invention therefore envisages wireless information devices which can supply or post ‘pre-answer’ information which the device owner considers of relevance to a potential call recipient. This information enables a potential call recipient to be given useful information about a potential call before actually answering that call. Examples of the kinds of ‘pre-answer’ information which a calling party can input include without limitation the following: information about the subject of an intended voice call, a mood, a current activity, part or whole of a schedule of meetings or events, information about the urgency of an intended voice call, personal information, expected call duration, commercial inducements to a consumer to answer a call (special offers, loyalty points etc.), location information. The information must however be dynamic (i.e. potentially variable) and hence does not cover persistent information, such as conventional caller ID information.
From an operator revenue perspective, allowing a calling party to enrich their communication with pre-answer information is more potent than conventional Presence since a calling party can be expected to pay for this additional data service. Conventional Presence systems require input from the call recipient and, arguably, will need to be paid for by that call recipient and, as such, are likely to be difficult to establish commercially. Revenue models based on the principle of the ‘calling party pays’ have tended to be more successful than those in which the called party has to pay.
The invention may also embrace the conventional Presence situation in which a caller can be automatically provided with Presence information relating to the called party prior to initiating or starting a voice call with another person. Hence, the present invention may cover the symmetric situation of, prior to a voice call starting, a caller being give Presence information about the called party (‘pre-call information’) and the called party being give Presence information about the calling party (‘pre-answer information’).
The format of the information can be text, or other media formats, such as images (e.g. a digital picture of the calling party's current location taken with a digital camera on the calling party's device), icons (e.g. heart icons as pre-answer information to a boyfriend); or animated graphics (e.g. a Lara Croft cartoon figure; a personal avatar). A user could have several different sets of information which it selects manually or automatically depending on other data (e.g. the person called). Hence, a user could have one personal avatar figure for calling friend, and a different one for calling family. Icons and graphics can be selected from a menu of pre-stored options and may also be obtained from a remote server, in the same way as ring tones are currently downloaded. Just as custom ring tones have been highly effective in enabling mass customisation of mobile telephones and have generated significant and highly profitable revenue for network operators and ring tone suppliers, so can pre-answer icons and animated graphics. Pre-answer information may accompany or replace the call recipient's ring tone, in much the same way that caller ID does. It may relate specifically to a call (e.g. the subject of the call) or be more general (e.g. a mood). The information will typically precede an intended voice call, although the voice call itself may not occur for a variety of reasons.
As noted above, in conventional Presence systems, information is generated for or posted by a person who may be called; this can influence and inform a caller making an outgoing call to that person as it can be read and used by that caller to assess the situation of the person to be called. But the present invention goes beyond conventional Presence because the information of relevance can also be posted by a person doing the calling: it can influence and inform the person receiving an incoming call as it can be used by that call recipient to assess the subject of the call, its urgency, the mood of the caller and any other item input by the caller which more fully defines the context of the call. As will be described later, pre-call and pre-answer information can be generalised to a ‘Virtual Presence’, which can take the form of a customisable virtual avatar and can also represent facts about any user, i.e. both callers and targets, in any messaging context, and hence is not limited to use prior to a voice call. Hence, Virtual Presence could be used not only to enrich voice communication, but also data communication such as chat and instant messaging.
The present specification goes beyond conventional Presence by suggesting new categories of information which can be posted/input (such as moods and personal avatars) and new user interaction functions (such as the ‘Convert to Text’, ‘Hold and Mute’, ‘Doodles’ and ‘EvolvIcons’ described later). These innovations are independent of the insight of providing dynamic pre-answer information to a call recipient (e.g. defining the subject of an intended call). Hence, this specification discloses multiple innovations which are not limited in their application to circumstances where pre-answer is also used.
Scenarios
If we take a situation in which Alice knows Bob, Bob might post a ‘mood message’ saying “I need cheering up” on his device. Alice decides she wishes to call Bob; when she looks him up in the contacts manager application on her wireless information device, and selects a ‘make voice call’ function, Alice's device initiates communication with Bob's device. Prior to opening a voice channel, Bob's device returns as data (e.g. peer to peer SMS, Smart Message (a Nokia format) or data packet such as IPv6) his pre-call ‘mood message’, so that the message “I need cheering up” automatically appears on Alice's device. The device then prompts her whether she wishes to proceed with the voice call and/or post a responsive ‘mood message’. She decides to do both; first she enters the message “I'll cheer you up Bob” and then initiates the voice call. Bob's device shows the “I'll cheer you up Bob” pre-answer message from Alice, so Bob immediately answers the call, already having a positive expectation about the likely social interaction with Alice.
Another situation might be that Bob posts a pre-call message saying “Anyone want to go to a cinema tonight?” on his wireless information device. He makes that information available to anyone listed in a ‘Friends’ category in his contacts database, held locally on his device. Alice decides co-incidentally to call Bob; Bob's device recognises Alice as belonging to his ‘Friends’ class (e.g. through caller line ID, or a unique ID associated with Alice's device which Bob's device knows) and so automatically sends Alice's device the “Anyone want to go to a cinema tonight?” data prior to initiating the voice call. Alice in fact wants to have a long chat with someone tonight, and decides that Bob is not the right person to call right now.
Bob might also post a pre-call message saying “Now in a meeting with my boss till 5 pm”. Then Alice, reading that information automatically provided to her when she selects Bob's name in her telephone application, can decide to not proceed with the voice call at that time. But perhaps if Alice knew Bob's boss, and wished to interrupt their meeting precisely so she could speak with both of them, she would call Bob immediately.
Knowing the situation of a call recipient in this way also allows the caller to override a call diversion function or call bar which has been set by the required call recipient. Suppose Bob is in an important meeting and decides to divert all calls from his voice based wireless information device to voice mail. Alice faces an emergency and must reach Bob. Alice can see that Bob is in an important meeting from the pre-call information he has posted. But she can do one of two things to reach Bob despite Bob's attempt to remain uninterrupted. First, she can send the pre-answer words ‘Emergency! Please answer’ to Bob's device, which can be programmed to beep or otherwise alert Bob when a message comes through with certain defined key words like ‘emergency’. Bob reads that message and then immediately calls Alice. Or Alice could be given by Bob rights to override his call diversion, which she can use at her discretion, with that discretion being exercised appropriately since Alice can see Bob's situation defining information. Override rights can be given to close friends and family and also to emergency services.
As noted above, the subject of an intended telephone call can also be defined by a caller as the pre-answer information. As an example, say Alice and Bob have an argument. Bob might ordinarily try to call Alice, who would likely not answer. With the present system, Bob can open his telephone application on his device and choose Alice from his contacts list; instead of just dialing out immediately, the application can present an on-screen prompt to enter a subject for the call, an indication of its urgency and how long the caller thinks the call might last and to select a suitable graphic. Bob enters into the subject field ‘I'm sorry’, indicates that its urgent and sets the call time to maximum. He selects a heart graphic. Bob then initiates the call; Alice's device rings and she can see from a display on her device that the call is from Bob, the subject is “I'm sorry”, the time duration is set to maximum and there is a heart graphic. The expected time duration is represented by a clock icon (which can show one of several variants, for example, a ‘quick call’ icon, ‘long chat’ icon etc.), although the user can alternatively just state in the subject field ‘Quick call’. Alice decides it's time to accept Bob's apology and answers the call.
As noted above, the pre-answer information may be sent as data prior to a voice channel being opened, for example as SMS data, a Smart Message or packet data (e.g. in IPv6 or other packet based system. The information is then displayed on the target device, together with various user prompts, including “Proceed with voice call?” and “Post reply message”. This data handshake can carry not only information which Alice or Bob have themselves entered into their devices, but also information which the device itself is aware of and is automatically entered; location information is one example of this. This information can be thought of as being ‘implicitly entered’ by Bob or Alice and references to an entity entering information cover both explicit and implicit entering; hence automatic entering of Bob's location information is an example of Bob implicitly entering that information. The information must however be dynamic (i.e. potentially variable) and hence does not cover persistent information, such as conventional caller ID information.
In another example, say Alice is already on a voice call to Sam; Bob selects Alice's name from his telephone application and a data handshake between Bob and Alice's device follows. This supplies to Bob's device the information that Alice is already making a voice call; if Bob has appropriate access rights, his device is also informed that Alice is talking to Sam and prompts Bob to choose whether or not to interrupt Alice and Sam to join their conversation.
In another implementation, the pre-call information is stored not only at a local device but is also posted to a remote web server, which a calling device may have access rights to poll. In essence, prior to making a voice call, a device connects first to the web server to collect any pre-call information posted there. Similarly, pre-answer information can be posted to the remote web server and be downloaded by a target device. This approach may be particularly attractive in a VoIP system, since the web server could be integral to the VoIP network and a server call is just part of the necessary voice call routing anyway. Further, holding pre-call and pre-answer data on a server (as opposed to keeping it just on a client) allows the data to be seen by one party even when the other has a device which is out of coverage or off/busy. Conversely, where a GSM system is used for the voice call, then a separate connection to a web server to download situation defining information is a considerable extra overhead and the peer to peer system based on SMS or Smart Messaging is preferable.
An alert may be sent to a person when the information describing the situation of another person alters in a way defined by the person. For example, Bob posts a pre-answer message “Please don't disturb” onto his device which Alice then reads on her device when she selects Bob's name from her wireless information device's contacts manager just prior to making a voice call to him. Alice doesn't need to interrupt him. So she programs her device to alert her when Bob's “Please don't disturb” message is removed by Bob. When that happens, Alice is alerted and can proceed to make the call to Bob.
The following extension to the previously described ideas is also within the scope of the present invention: say Bob wishes to speak with Alice about going out tonight. Bob enters as pre-answer information the subject line ‘Dinner tonight?’ and the quick call duration icon and initiates the call to Alice. Alice is in an important meeting and has set her device to flash an on-screen indication of the subject and caller name of any callers; she sees Bob's name and his subject line. She decides she cannot take a voice call but can take a few moments to send a text response. She then responds to the incoming call by selecting a ‘respond with text message?’ option, rather than an ‘accept voice call?’ option shown on her screen's device. She is then given a field into which she can type a message; that message is then transferred as data to Bob's device for display on his screen. Bob responds with his own reply and the data communication is then terminated. The voice call part of the call has not in fact commenced at all—the communication has been handled entirely using text data transfer.
In a second aspect, there is a wireless information device controlled by a calling party and programmed (i) to allow information to be entered into it, the information being of relevance to a call recipient with whom the calling party wishes to communicate, and being of a kind which varies, and (ii) to transfer that information so that it can be read by a second wireless information device controlled by the call recipient; whereby the call recipient using the second device is automatically provided with the information prior to answering or accepting a voice call from the calling party.
In a third aspect, there is software for a wireless information device which, when running on the device enables the device to perform as a wireless information device as defined in the second aspect.
In a fourth aspect, there is a method of generating revenues relating to the use of an application on a wireless information device, in which the wireless information device is as defined above. Calling parties might therefore pay a flat fee (e.g. monthly or quarterly) to their wireless communications provider in order to enjoy the functionality defined above.
In a fifth aspect, there is a method of generating revenues in which a calling party pays to perform the inventive methods defined above. Calling parties might therefore use the functionality defined above on a pay-as-you-go basis to their wireless communications provider.
In a sixth aspect, there is method of allowing a data file to be downloaded, in which the data file is capable of being used as information which is (i) sent by a calling party to a call recipient prior to answering or accepting a voice call from the calling party, and (ii) is of relevance to the call recipient with whom the calling party wishes to communicate, the information being of a kind which varies. The data file can be an icon or animated graphic.
Further details of the invention are contained in the claims of this specification.
DETAILED DESCRIPTION
The present invention will be described with reference to a project from Symbian Limited of London, United Kingdom, called the Voice ++ project. The Voice ++ project has identified two key mechanisms for the enhancement of the mobile telephone experience, namely:
Virtual Presence Asynchronous communication
Virtual Presence
Virtual Presence offers the user an opportunity to define a virtual identity for themselves. Through customisation of their ‘look’ (i.e. how they are perceived by another user) they can be more than just a list of numbers in someone else's Contacts list. Callers can see the target's (i.e. call recipient) Virtual Presence in their Contacts list. Targets can see the caller's Virtual Presence. Expressing personality is in itself a highly attractive feature for specific segments of the market, i.e. the Teens. However Virtual Presence is not simply static information of a ‘look and feel’ nature. It shows not only the personal expression of another user's identity but also has the potential to show a whole wealth of information about the user:
The user's Mood—(e.g. for a target: ‘Don't Disturb’, ‘Working’, ‘Out Partying’, ‘Commuting’ etc.—these can encourage the caller to either: call immediately, call later, send a text or voice message, not call at all etc. For a caller: ‘Urgent! Please pick up’ will encourage the target to pick up). Their location—of varying granularity—i.e. ‘London N17’, ‘Sainsbury's—Clapham’. Phone Status—i.e. ‘Busy’, ‘Available’, ‘No/poor network coverage’, ‘No battery’ etc. Messages from the caller or target—‘Working from home’, ‘Out on the town’, ‘Out of the office till 2 Feb. 2001’ etc. PIM information—i.e. during the day, data available from the Calendar application may indicate which meeting the caller or target is currently in. The preferred communication mechanism—as indicated implicitly or explicitly through the Mood and caller Messages etc. The Network Situation—i.e. Name of network operator, Call charges at the intended time of the call etc.
With games and Third party applications the attractiveness and usefulness of such a Virtual Presence has the potential to expand greatly.
The Detail
At its most basic level, Virtual Presence offers the caller information about the availability of the target. In turn the target may see more than simply the name of the caller.
By putting his phone into a specific Mood, the target can specify their availability and therefore provide the caller with information about how they would like to be contacted, i.e. ‘Only available for text chat’ (this automatically suggests the use of text for communication), ‘By all means ring me’ etc. In addition, the status of the mobile itself can provide the caller with information about whether now is a good time to call, i.e. the mobile may be in ‘By all means call me’ Mood but the target is currently in a call. The caller may choose therefore to activate Ring Back (See Ring Back Service Description) or simply try again in a few minutes. In this way the caller and target can automatically exercise an element of control over the communications which to date has not been possible.
Illustration:
By the target putting the phone into a “Don't Disturb” Mood, the caller can be prompted to send a voice or text message instead. Depending on how the target has specified the behaviour of ‘Don't Disturb’ they may receive a prompt (a short vibration) that a message has been left, or no prompt at all in which case the next time they switch out of ‘Don't Disturb’ Mood they will be notified that messages have been left for them. NB: This should not be taken to mean that a Mood such as ‘Don't Disturb’ would prevent calls being placed, rather it is simply the case that the target is advising the caller to leave a message rather than call. This degree of functionality alone provides a major part of the control that users are looking for. Depending on the Mood settings they use, the target can leave the phone on, i.e. can use it for their own purposes but can ensure (assuming social protocols are followed—see Social Protocols discussion) that they are contactable as and when they want to be and in the manner that they choose.
At the most basic level therefore, the mobile telephone can ship with a small core set of Moods which the user can easily switch between much in the same way as mobiles currently offer a core set of profiles which (in the main) control the physical behaviour of the phone.
Taken a step further however the customisation of these Moods by the caller and also the target enables them to extend their Mood into a rich Virtual Presence rather like Avatars available on the Internet (i.e. with variations of ring tones, graphics, animations, messages etc.) Both parties can offer rich, dynamic and fun information. In the same way that Ring Tones and graphics can be downloaded, supporting Avatar type data could also be available. While it is suggested that the mobile ships with a small core set of Moods, it is likely that users will develop several Moods with the same underlying preferences but which display quite different Moods, i.e. Meeting and Clubbing. In both instances the user might not want any communication other than text but the information provided for the caller (or target) implies radically different states.
Users would likely be keen to provide a virtual representation of themselves. Behaviour on the Internet suggests that some segments will make a great deal of effort in creating a Virtual Presence. While this behaviour is indeed PC based, in the main we can already see such personalisation behaviour occurring in the mobile space too. As described above some segments of the market will go to great pains to personalise their phone, with ring tones, hard covers and on screen pictures. Given an easy customisation environment some segments of the market will extend this behaviour to the mobile virtual world. Users are already using their mobile to make effective use of ‘Dead Time’ by the creation of text messages and fiddling with settings. With appropriate functionality it is highly likely that the desire to ‘play’ with their Virtual Presence will be equally attractive. This factor encourages the creation of new Moods which not only provide users with a more meaningful presence and greater control of their mobile but also inherently provides users with a far richer standard of Pre-call and Pre-Answer information. Ultimately the Internet and mobile based Avatars will probably merge and a user will have a Virtual Presence the complexity of which is purely dictated by the viewing device and its settings.
Social Protocols
The value of Moods is to some extent dependent upon adherence to the social protocols that such a service implies (i.e. the need for the caller to respect the Mood indicated by the target and to behave accordingly, and vice versa) These social protocols are already well established in face to face communication: the demeanour of the target can be perceived and judgements made by the person about to initiate the communication as to whether or not now is a good time. These protocols are recognised and as relationships get established people know the extent to which they can break these protocols. Moods simply provides a similar degree of information in the virtual space.
The Avatars visible to the caller and target may in fact be tailored. Applications which can reflect the relationships with contacts facilitate the development of emotional messages (See EvolvIcons Service Description). Pre-call and pre-answer information can also grow as the relationship grows or could dictate that specific callers are always sent to VoiceMail. People customise their Instant Messaging presence according to who can see that presence information and some people will spend time customising ring tones etc. for specific people. It is predicted that, for key individuals in particular, users will personalise their Virtual Presence too.
Clearly there will be instances where it is desirable to over ride the Mood specified by the target (i.e. in emergencies a caller may ignore the request for text only and may still place a phone call.) It is not the intention of Voice ++ to suggest that Moods are enforced: there are always exceptions to the Moods and the target would be unwise to create a Mood which prevents an emergency call from reaching them. The Moods are there as recommendations to the caller. And the target can always make use of features such as Hold (see later) to take back some of the control. The extent to which the target insists that the Moods are adhered to is down to individual personality. It could for example be encouraged through the addition of a short message accompanying a Mood, (i.e. if in ‘Don't Disturb’ Mood, the target may also add a text message as part of their Virtual Presence which says “and yes I do mean it ”), a message that everyone (or specific violators of the metaphor) see.
Asynchronous Communication
Users already engage in large amounts of asynchronous behaviour. Text messaging is widely acknowledged as a major use of the mobile phone. Despite the tedious nature of inputting the text itself, users still engage in brief, asynchronous chat. It is seen in use not only during ‘Dead Time’ when a call is inappropriate or impossible but on occasions when an entire conversation is unnecessary or undesirable. Being able to transfer information at a point in time convenient to the user places the user back in control of their mobile. This chat takes a variety of forms being anything from inane chatter about what they are doing or have done to the transfer of information i.e. a phone number, location instructions etc. to another person.
The spoken nature of voice messaging provides the user with an even faster means of having these asynchronous ‘chats’ with other people, although clearly there will be situations where text is still preferable. However, with the development of speech to text technology, voice messaging could at the very basic level simply be viewed as the input mechanism, i.e. if the caller is in ‘Text Only’ Mood this message could be turned into text. Nuance and intonation forms a key part of aural messages and this would be lost in current conversion techniques, therefore, forcing the conversion as part of a Mood may not be desirable.
A key issue for the user experience in the creation of asynchronous data, be it verbal or textual, is that it should not be tied to any specific application on the mobile. We naturally multi-task and the creation of a ‘Doodle’ (see later) in one location on the mobile for example should not prevent that easily becoming a text message.
What This Means for Voice ++
The following Services are of key importance in the fulfillment of the aspirations described above:
Virtual Presence:
Pre-Call—encompassing various elements including: Moods; Convert To Text, Phone Status, Doodle, Information Management, Ring Back, plus Avatar type data etc.
Pre-Answer—encompassing various elements including Moods; Convert To Text, Doodle/Post, Information Management, Advanced VoiceMail including: Call Screening, Pause/Play/Reply to VoiceMail and Hold as well as Avatar type behaviour.
Asynchronous Communication:
Voice Messaging
Doodle.
These two areas satisfy the key requirement identified during the Voice ++ research, namely enhancing the call experience such that the user perceives themselves to be in control of their mobile telephone.
Service Descriptions
The following Service Descriptions satisfy the key requirement identified during the Voice ++ research namely the establishment of user control over their mobile telephone. See Appendix A for all other Service Descriptions.
Pre-Call and Pre-Answer: General Points
Currently both the caller and target experience is quite impoverished. At best the caller can make suppositions about the availability of the target, i.e. “It's 9:30 am, they should be in the office by now”. In this instance, there is no way for the caller to determine the validity of their assumptions without actually placing the call. Similarly the target will at best be able to see the name and/or number of the person calling. If the target can see the caller ID, they may try to base their decision of whether or not to accept the call on: possible reasons for the call; the importance of the caller; guessing the call subject matter; their own convenience (amount of time they have to take the call, where they are when they receive the call) etc.
Other communication types have richer information:
face to face—visual cues indicate physical availability of the individual and their readiness to communicate; written communication—while the immediacy of the communication is removed and availability less of an issue, the user has access to additional sources of information and, through its asynchronous nature, has time to think about the communication.
Pre-call and pre-answer offer respectively the caller and the target the opportunity to have a far richer call experience, enabling them to make informed decisions when making and taking calls. In some cases it may even alter the communication, replacing it with alternatives or stopping it altogether at that time.
Pre-Call
Current Stories:
1. Helen is about to leave the office and wants to call Steve and to tell him that the plans for the evening have changed and to ask him what time he will be able to meet her. She selects Steve from her contact list and initiates the call. Steve is in a meeting and has switched his mobile to Silent mode. Helen is bumped to VoiceMail and has to leave a message asking Steve to call her when he has a minute.
Pre-Call means that when about to make a call the caller can see the Virtual Presence of the target. Steve could have put his mobile into “Text Me” Mood and Helen would have seen this and contacted him appropriately, getting a response to her question without significant interruption to his meeting.
Pre-Call may include any of the following types of information in addition to the fun, Avatar type visualisation discussed in previous section.
Availability Information:
Mood Status of the target—i.e. ‘Don't Disturb’, ‘Working’, ‘Out Partying’, ‘Commuting’ etc.—these can encourage the caller to either: call immediately, call later, send a text or voice message, not call at all etc.
Location Status—of varying granularity—i.e. ‘London N17’, ‘Sainsbury's—Clapham’.
Phone Status—i.e. ‘Busy’, ‘Available’, ‘No/poor network coverage’, ‘No battery’ etc.
Target Messages—‘Working from home’, ‘Out on the town’, ‘Out of the office till 2 Feb. 2001’ etc.
PIM information—i.e. during the day data available from the Calendar application may indicate which meeting the target is currently in.
In addition the caller may also see information from their own device pertaining to the call.
Supporting Information:
Doodles—written by the caller on a previous occasion regarding this caller, i.e. ‘Remember to ask x’ etc. or taken dynamically from the Calendar application i.e. ‘Daughter's birthday on 22 Feb.’. (See Doodles Service Description).
View previous communications with the target (see Information Management Service Description).
The caller may also choose to actively provide the target with more information, for pre-answer i.e. entering a call subject, or using flags to indicate whether the communication as ‘Urgent’, or ‘Chat’ etc. This expanded on in the next section.
Pre-Answer
Current Stories:
1. Sarah is in a meeting but has emailed Clive asking him to ring her with some information. She would be willing to accept the call should it occur during the meeting. Sarah's mobile rings during the meeting and she can see that it is Clive. She excuses herself from the meeting and accepts the call. When she speaks to Clive it transpires that he hasn't received her query yet, he was simply calling to see if she would be joining the rest of the team in the pub later.
2. Richard is in a meeting and his mobile rings; the caller ID indicates that it is his wife, Judy. She usually rings him at the office during the day just for a quick chat, so he decides to bump her call to VoiceMail and get back to her when he has finished the meeting. Judy is upset as their son's school has just phoned asking them to come in to see them that evening; she is forced to leave him a message telling him that she needs to talk to him a.s.a.p. Richard leaves the meeting an hour later and finds the distressed message calls Judy back immediately.
Pre-Answer means that when a call comes in, the target can see the Virtual Presence of the caller. By flagging a call as urgent or simply allowing the text message to come through Richard would have realised the significance of the call and probably chosen to take it, whereas in Sarah's case she may have chosen to ‘bump’ the call to voicemail as it was purely social.
Pre-Answer may include any of the following types of information in addition to the fun, Avatar type visualisation discussed in a previous section.
Name of the caller. Location of the caller. Mood Status of the caller—this may in itself provide clues about the reason for the call, i.e. ‘Partying’, ‘Working’. The more that callers customise their Virtual Presence the more meaningful the information to the caller i.e. ‘Out Clubbing’, ‘In Meeting’ etc. Specific subject/status information—this may have been specifically entered by the caller to help the target or have selected it from a pre-canned list i.e. ‘Urgent’, ‘Chat’, ‘Work’ etc. It could also be gleaned from PIM/Smart data, i.e. if the call is initiated from within a specific text message or from a calendar entry—the first few words could be visible to the target. The extent to which the caller will bother to provide such information is dependent upon both the personality of the individual caller but also the ease with which such information could be added.
Supporting Information:
Doodles—written by the caller on a previous occasion regarding this caller—i.e. “daughters birthday”, “remember to ask x” etc. (see Doodles). View previous communications with the target (see Information Management).
The target is not only in a better position to choose whether to accept the call but to decide the way in which they accept the call. For example, they may choose to screen the call—listening to the message being left on their VoiceMail (See Call Screening Service Description) and then decide whether to answer or not. They may choose to put the call on Hold initially (See Hold Service Description) so that they can get into an appropriate location to answer the call or so that they can view/listen to their own Doodle prior to taking the call so that they are better prepared for the call. They may simply answer or ignore the call as currently.
Convert To Text
Currently when a call is received the caller can do one of three things: accept the call; forward the call to VoiceMail or let the mobile ring out and automatically forward to VoiceMail. Alternatively, if the mobile is off or out of range then the caller is automatically forwarded to VoiceMail. In all but one case the communication ends even though there may be various reasons for not taking the call, i.e. a noisy pub or in a work meeting.
Convert To Text offers the target the ability to manage the manner in which other people contact them. This may take the spontaneous/reactive route whereby during Pre-Call the target indicates to the caller that a text communication is preferable. Alternatively it may be that the target puts their mobile into a ‘Text only’ Mood because they know they are going to be in a meeting or in a noisy pub etc. Hence, a caller should then contact them via text or, if they go ahead despite the pre-call message and place a voice call, then the target can automatically respond by inviting the caller to participate in text communication.
Current Stories:
1. Bill is in a club with his friends. His girlfriend, Michelle, phoned him earlier to say that her train is running late and that she will be later than planned. She has agreed to call him when she arrives at the station so that he knows when to look out for her. The club is typically noisy and when Michelle phones, Bill repeatedly has to shout that he can't hear what she is saying. In the end he has to run to the cloakroom, stick a finger in one ear and try again.
2. Tony is on the train home and his wife calls him, as always, to determine what time to meet him at the station from work. On occasions people ‘tut’ at him or frown at the noise from his conversation and just occasionally he gets a bit of an earful from his wife about the fact that he is running late, and he then has to go into a lengthy explanation, something that he would rather not do in front of a crowded train. Regardless, he needs to tell her when he is leaving so that she can be at the station to pick him up.
By being able to switch an incoming call to text (Story 1 ) the target can take the call in a way that suits them. Alternatively by automatically putting the phone into a Mood whereby the caller can see that they would prefer to be contacted by text, the communication can automatically commence in the format suited to the target (Story 2 ). The addition of Location information as part of the Virtual Presence may even provide sufficient information to remove the need for the communication (Story 2 ).
Call Screening
Users already screen messages as they are being left on land line answering machines. This service replicates that functionality on the mobile. The user is able to listen in on a VoiceMail as it is being left and can interrupt and take the call or to stop listening and let the caller continue to leave a VoiceMail. In addition, poor and non-existent mobile coverage is highly irritating for both the user when downloading material to the device or when listening to VoiceMail. Text messages are sent to the mobile when there is sufficient coverage: the same could be the case for VoiceMail enabling the user to listen to messages even when coverage is intermittent.
Current Stories:
1. George is sat in an important meeting when his mobile vibrates. He can see that it is his son Thomas ringing. He is unsure about the importance of the call but as he knows that Thomas should be on his way home from school he thinks that he ought to take the call, just in case. George excuses himself from the meeting and takes the call only to find that Thomas is calling simply to tell him that he scored two goals during football practise. George has to cut his child short and returns sheepishly to the meeting.
Ideally George would be able to start listening to the call, decide that it is better to speak to his child later when he can dedicate his full attention to the him.
Hold and Mute
As mobiles can be used practically anywhere and people are increasingly unwilling to turn them off, it is not uncommon to hear a mobile ringing in meetings or a restaurant or cinema etc. Occasions when it is inappropriate to some targets and certainly inappropriate for the people around them. Nor is it unusual for it to ring just at the wrong moment i.e. when ‘working from home’ just as the shop public address pages a member of staff. Our research has shown that people frequently conceal the truth about where they really are. Trying to take a call when in an awkward situation frequently results in one of two activities “Hang on I'll call you back in one minute” or the target continuing the call and then proceeding to give the caller a running commentary of their antics while trying to get to a convenient location to take the call. Users want to be able to mute the audio of their handset while still being able to hear the call, or place the call on Hold initially before they accept it so that they can get into a location convenient to start the call. This could be easily activated in the same way as Hold is currently activated once in a call, i.e. using a prolonged press of the call answer button or double clicks of the call answer button etc.
A progression from putting a call on Hold is changing the communication mechanism to one that is appropriate i.e. text (see Convert To Text Service Description).
Current Stories:
1. Tom is on the train in a quiet carriage. He doesn't like taking calls in public areas like this, as he feels it is inconsiderate. On this occasion he forgot to turn his mobile off and when it rings he is mortified and frantically hunts through his pockets to locate his mobile and “bump” the call. As he pulls it out of his pocket he can see that it is his wife calling. He wants to take the call but does not want to shout in the train carriage. He answers the call so that she doesn't get bumped to VoiceMail, but then has to start the conversation with “hang on I'm just having to move so I can talk to you” followed by several minutes of fumbling and apologies to fellow passengers while he climbs over them to get to the end of the carriage.
2. Richard is supposed to be working at home, against a deadline. He has decided to take a break and go to Tesco's for some grocery shopping. Whilst in the shop, his phone rings and the caller ID indicates that it is his boss. Richard reluctantly answers the phone and quickly answers his boss' questions, hoping that his boss will not hear the other shoppers in the background. Suddenly, a staff announcement is made and Richard has to cover the phone's microphone so that his boss does not hear the announcement. The call ends, with Richard still wondering if his boss has figured out where Richard was.
In both scenarios, a ‘Hold and Mute’ function would have been far preferable.
Asynchronous Communication
Voice Messaging
Asynchronous behaviour is already a significant part of user's mobile behaviour. The ease with which verbal messages can be created means that it is a natural extension of the text messaging behaviour. The user should be able to create voice messages and send these directly to another person's VoiceMail without the caller being any more aware that this has happened than is currently the case with text messaging.
It should also be possible to simply change data from one medium to another. (i.e. a voice note into an text message, a Doodle into an text message etc.). Data should be independent of the mechanism by which it is delivered: Doodles, text or voice recordings can in the right situations form appropriate content for personal notes or the content of messages to others.
The teen market view SMS as an ideal way of communicating with their friends. Communicating via text is for them a means of communicating in private (something which can otherwise be difficult both at home and school) and voice SMS will enhance the speed with which they can do this. The need for privacy rather than speed is likely to be the determining factor when people are choosing between text or voice as the creation mechanism.
Current Stories:
1. Susan is on her way out of the house when she remembers that she needs to call her mother to and confirm dates for her visit. She is in a rush and knows that if she calls it will be difficult to keep the call short. On this occasion Susan decides not to make the call.
If she had been able to simply record a quick message to her mother, she would have removed the worry of forgetting to pass the information on and would be able to make a more leisurely call at her convenience. ‘Urban Socialites’ particularly want to be able to off-load information at a time convenient to them. At present they may leave making the call until they know it is not likely to be answered or may simply avoid calling all together.
Doodles
It is not uncommon to make a call and on ending the call to remember something else that you wanted to mention. Depending on the person you have just called you may choose to call them back and continue the conversation. However there are factors (such as time, status of the person being called, whether or not you will get the same person the next time you call (i.e. a call centre), personal confidence etc.) which determine whether or not it is a good idea to call again immediately. Similarly, when in the middle of a call it is not uncommon to see people scribbling notes or doodling on the back of a nearby envelope. These are activities that may or may not be connected to the call itself. Some people claim to “think” better if they are doodling aimlessly at the same time as talking. Information exchange is a common reason for a call, and in some instances this may result in information that ideally they want to record in some way.
As headsets, particularly Bluetooth headsets arrive, the need for the mobile telephone to be held to the ear is removed. This frees up the interface of the screen for services that will enhance the call experience. Doodles offer the user the ability to associate data with a communication. At present users employ a number of techniques such as sending themselves text messages as reminders or sticking adhesive notes to the phone, such processes assume that i) the user remembers to look at text reminders and ii) that the note is still stuck there.
By associating the Doodle with the communication, i.e. the Contact, (ideally converting voice to text—unless operating with a headset) it would be possible to have reminders as part of Pre-Call and Pre-Answer. It should also be possible to view and add to the Doodles while the call is in progress, replacing the need for a notepad.
Adhesive notes are often left on a colleague's desk or are left around at home for other members of the family. They are either for the exclusive benefit of the other person (i.e. “your mother called at 3:30 pm”), or for the use of both (i.e. “run out of milk and bread”). It should therefore be possible to send Doodles to other people (e.g. converting them to text messages). The difference to just sending a normal text message is that you can retain a copy and the appropriate “linking” of that Doodle if so desired. It should also be possible to share a Doodle with other people. Doodles can be voice as well as text and could ultimately be multimedia.
Current Stories:
1. John has been trying to get through to his bank for a number of hours. He has a couple of queries for them. While in a café for his lunch break he decides to try again. It is only after he has started the call that he realises that the adhesive note he wrote to himself is back on his desk. The bank answers and he gets answers to two of his queries, he knows there was a third question but he can't remember for the life of him what it is. After a few embarrassing moments of dithering he knows he is not going to remember the third point and he ends the call knowing that he will have to call the bank again later.
2. Matthew is in the pub with friends when he remembers he had intended phoning his sister Joanna to ask for the mobile number of the restaurant that she had recommended he take his girlfriend to. Matthew is standing outside the pub entrance where it is quieter and makes the call to Joanna. Joanna tells him the mobile number and Matthew repeats it hoping that he will be able to remember it until he gets back to the table where he can shred a beer mat and write the number on it for use later.
3. Tom and Sally are having friends round to dinner in the evening. Whoever gets home first needs to pop round to the corner shop to pick up a few last minute ingredients. They leave an adhesive note at home so that whoever gets in first can take it back out with them. On his way home, Tom passes a convenience shop and thinks that he can remember all the ingredients. However, he doesn't know a) whether Sally is home already and has therefore bought the ingredients already, b) that he has really remembered everything.
Being able to capture information on the mobile (either through voice or text—the former being preferable) enables users to transfer behaviours that they can easily do currently on a landline where paper and pens are likely to be at hand. In this instance however they can carry this data with them in the form of a Doodle without risk of loss (unless the mobile itself is stolen too) and can even be associated with other information.
In the last Story Tom could: use the Virtual Presence to determine Sally's whereabouts, phone her to check whether she has bought the ingredients or more conveniently look at the shared list and see whether she has added a comment showing that she has bought everything already.
Conventional applications such as Jotter and Notes provide the user with a mechanism for making notes in support of call activities. However, this relies on the user remembering that this note has been made and it requires them navigating to it in a timely fashion for the call. The advantage of Doodles is that the information can be created anywhere and associated within any relevant location. This may occur in one of two ways:
1. Automatically—creating a Doodle while in a contact detail view could associate that with that particular contact such that should that contact be accessed in the future the Doodle will automatically appear too.
2. User choice—the user may create the Doodle in one application and choose to save it to another association, for example a Doodle created during a call could automatically associate it with that contact; alternatively the user could choose to save it in the to-do list or as part of a calendar entry as a reminder.
In either case, establishing links ensures that the data is available when it is needed. As in the case of Scenario 1, the caller can associate the questions for the banker with the banks call centre details, he can add to these during the call and retain a far more detailed record of the call (and all in the same location). Note: Data captured in this way may form part of another piece of device data, i.e. if as a result of the call to the call centre John has arranged an appointment with a bank manager, the notes made during the call could become associated with the calendar entry also so that he has all the information at his finger tips without having to hunt around for it. In addition a Doodle may simply be a link to data elsewhere on the device. To the user it appears as a Doodle but actually it is content that has been flagged in another location i.e. the content of an email, or the section of a document etc.
In the same way that a user can have layers of physical adhesive notes overlapping and linking to each other in a physical manner, the same is the case for the electronic equivalent. Doodle can be linked to form a montage.
In addition, the advent of the Bluetooth headset increasingly frees up the devices' interface for such activities such that the use of Doodles is viable not only prior to a call but also during it: Doodles can be played as calls come in if the user Pauses the call prior to speaking to the caller.
While Doodles have a key user benefit for the person creating them, there is also the flip side of the behaviour in that they are often given to other people. For example in Scenario 2, Doodle would have enabled Matthew to create an electronic record of the number as Joanna gave it to him. However they would also enable Joanna to help him out, i.e. by sending him a Doodle which not only contained the information but also an association information that it came from her. At which point Matthew would be able to choose to either leave the information associated with his sister or make it into a contact entry in it's own right. (Clearly she could simply send him an SMS without the association. In some instances this is more appropriate though for example a colleague sending a Doodle reminding the caller to bring a document to the next meeting could be usefully associated with the actual meeting in question).
The ability to share Doodles requires the hosting of the data in a central location rather on the device in order to prevent conflicts when data is being updated by either party. The underlying premise of a shared Doodle is that it is available to both at all times and that both parties can edit it: it is not necessary for either to own it.
Play/Pause/Reply to VoiceMail
Currently the extent to which users can interact with their VoiceMail is along the lines of playing the messages and deleting them and setting preferences for how VoiceMail notifies the user of messages waiting. Ideally VoiceMail should enable the user to play individual messages, pause them and enable them to carry out tasks as a result of individual VoiceMails without having to listen to the whole lot again. At present listening to a succession of VoiceMails requires paper and pen, good coverage and patience.
Appendix I—Other Service Descriptions
Picture Messaging
This relates to the ability to send and receive (and create) visual messages—graphics or photographs. While in the first instance simply being able to download pictures from the web onto the device and send these as images within a text message is sufficient, it is increasingly likely that users will want to take pictures and draw their own. To then be able to make additions and alterations to existing images and photographs and to attach sound bites to them is essential. While there are clear work contexts for such a service, use in the social context is likely to be wide spread and given the often superficial nature of many text messages currently it is fair to assume that the use of pictures will follow a similar line and the ability to annotate these will possibly enhance this.
EvolvIcons
The ability to present Moods in the virtual space lends itself to the development of applications which can build on the user's avatars and enable them to develop emotions as well as simply personal animations, sound and graphics.
Being able to send emotions as well as pictures, sounds etc. counteracts some of the sterility of such static communications as text messages. In the first instance being able to annotate and doodle over images and photographs which are being sent to other people is fun, but being able to attach meaning to these of a non textual nature is even more aesthetically compelling.
Applications which can reflect the relationships with contacts in the user's phone facilitate the development of not only emotional messages as described above but also in the extension of the Moods idea in that Pre-Call and Pre-Answer data can grow as the relationship grows and can be customised on an individual level. People customise the Instant Messaging Presence dependent upon who can see that presence information. It is likely that people will also spend time customising their Virtual Presence for key individuals.
Information Management
The mobile already holds a significant amount of information. It contains all the contact information and some devices enable the inclusion of additional textual information, including the text messages and email messages received to and sent from the mobile telephone.
As mobile functionality increases the amount of information that can be made available is potentially huge. In certain circumstances this information can be of value to the user prior to or during a call. The all inclusive term Information Management may include:
Communications to and from the Contact. Number of calls and the cost of the calls to the Contact. Meeting entries associated with that Contact. The last communication with a contact. The next meeting scheduled with a contact. The agenda for the last meeting with a specific group.
So providing the user with the ability to use and search this data can provide them with far more information in their communications. The presentation of such information is system initiated in the case of Pre-Call but user initiated during a call.
Ring Back
If when a call has been placed, and the caller is already in another call, the caller can initiate Ring Back which offers the ability to specify that when the line becomes free a call between the two parties should be automatically initiated. This replicates functionality already available on land lines.
If via Pre-Call the caller can see that the caller is currently on the mobile, the caller can initiate Ring Back without needing to first place the call.
Appendix II
Presence: architecture aspects
The realisation of a Presence/Voice++ system will require an architecture for instant messaging and presence awareness/notification which includes: a concept of identity, authentication, access control, encryption, message integrity and shared content.
Identity
Clearly, identity is essential: individuals will use several devices of different types, and capabilities, requiring an effective and efficient addressing system to handle and simplify the multitude of email addresses, phone numbers and www-addresses for individuals, groups and organisations. This may also necessitate some form of classification of the basic modes of communication to help define the basic requirements for applications, devices and service providers. Importantly, individuals may wish to assume several different ‘Identities’, for communicating within different contexts.
Actor/Personae
An Actor has 1 to n Personae through which they communicate with other Actors. i.e. communication is Persona-to-Persona based rather than Actor-to Actor based.
The Actor ‘owns’ the data/information/files in its Personal Universe but provides restricted views/access to it through their set of Personae.
In addition, each Persona has values for a set of Persona-based attributes associated with it (e.g. Nickname, font for chatting, icon for Avatar, etc. as well as a Persona Personal File containing their ‘history’—schools, hobbies, clubs, likes, dislikes etc.)—this must be extensible so that communities of Personae may be set up, each containing their own distinct community-based information—e.g. a multi-user game which requires Persona to have certain attribute/value pairings for such things as Strength, Agility, Life, Bullets, etc.
Each Persona is uniquely identifiable such that it can act in end to end communications. This should not be device specific as the ID provides a means of communicating with the Persona not the method. Initially users will be given choice of communication methods (phone, email (work/home) etc.) and will make the appropriate choice given the set of presence and availability information. Later systems may route a message (with appropriate translations—voice/text text/voice etc) to the appropriate device depending on the availability policies set up by an individual.
It is the Personae that appear in Directory LookUp services.
Each Persona has its own Presence Information.
One persona is the Master Persona that is the true representation of the Actor. This may be an authenticated/signed persona.
A Persona may be anonymous.
Presence
In its basic form Presence enables people to communicate with each other in the most appropriate and timely fashion. It should be possible for this presence information to be refined with levels of availability (e.g. ‘away from device but back soon’, ‘do not disturb’, etc.). Some of these refinements should be understood by the software so that they behave in appropriate ways while others may simply be displayed to other clients in a human readable form for them to decide how to respond.
An Actor should not need to maintain presence information at all times on all known contacts. Instead they should maintain a ‘buddy list’ with their favourite contacts. Presence information can be maintained by ‘subscription’ whereby changes are pushed to interested parties or returned when specifically requested (by a ‘watcher’ or ‘poller’). An Actor may only want subscriptions to be possible to selected other Actors/Personae.
Presence information comprises dynamic information such as location and availability, etc., which typically has expiration data that needs to be enforced. Initially, at least, availability will be inferred from the recipient's published mood and the status of the device.
Availability
A property of a Persona denoting its ability and willingness to share information about itself or to communicate with another Persona based on factors such as:
the type of communication requested; device availability and status (out of coverage, downloading data, etc.) the identity of the calling Persona; the mood of the recipient; the preferences and policies that are associated with the recipient.
Mood
A setting which allows the user to provide an indication of their state of mind. This is likely to provide not only their state of mind but an indication of their availability and a preference for how they want to be contacted. I.e. If ‘Angry’ and ‘Busy’ the user may have specified that this means they are only available for chatting in text form.
Location
GPS (absolute and translated). Bluetooth Pods in offices etc. Text (e.g. ‘Down the White Horse’).
Architecture
Client/Server. An Instant Messaging and Presence (IMP) Server holds master copies of Presence information and other Personal Data (Personal Universe). Personal data could include such things as: MP3 files; photos; credit card details; DoB and other auto from fill stuff; medical records; Agenda; Public PGP key, etc. i.e. file, record and transaction based shared content. The server listens for client connections and communicates directly with clients and other servers. The server also handles: data storage, user authentication, directory lookups (e.g. LDAP) and Rosters, etc. The client communicates with the IMP server, parses and interprets well-formed XML packets and understands message data types. Each Actor and their set of Personae is associated with a single server which receives information for them and from them. Clients make a single connection to their server over which all communication exists. Distributed communication happens client→server [→server]→client. The servers transfer messages and presence information between themselves and, with the appropriate interoperability standards in place (e.g. SIMPLE), with other external IM and presence systems too. When a Persona's Presence or other Personal Data changes (either explicitly by the Persona, or implicitly by, for example, a timeout, the IMP server is updated. For Presence information this may be very simple in the first instance, aided by a set of profiles for ease of use, or an enumerated set for programmatic processing plus a text field for additional information. Individuals hold cached copies of other's Presence information (and other information—probably more static in nature). This is just for Buddies but may wish to view available public presence information on anyone: Anonymous Presence Request. When a buddy's presence information or Personal Data changes, and if they are permitted to access the particular data that has changed, and if they have subscribed to that data, they are informed. The changes will either be pushed or pulled depending on subscription model. Pushed changes will be immediate whereas pulled changes will be retrieved when the server is next polled. Could force a push. The Presence Data could be time-stamped with when the information was last updated.
Data Format/Protocols
Client/Server protocol (preferably an open XML-based standard). Used for client-server, server-client and server-server communication (session initiation, modification and termination). Server-to-server protocol—could be proprietary between homogenous systems but will probably be SIP/SIMPLE for interoperability between heterogeneous systems. Data representation protocol: a fundamental requirement of the architecture is that it must be extensible. As such, an open XML-based standard protocol should be used for packaging/transporting data (IM, presence data and personal information). The protocol should use XML Namespaces to encapsulate other kinds of data sent, allowing any client, server, transport, or any component of the architecture to build custom applications by including their own XML data within their namespace. Could be SOAP.
Messaging
Messaging is essentially the sending of some data from one Persona to another. The data is not restricted to text, but may be any well-formed data that can be recognised by clients including text, voice, multimedia, Presence Information, etc. Common standards for these data types coupled with a common standard for their transfer (described above) will greatly ease the development, roll-out and adoption of data services and applications that build upon this architecture. One application of this is Instant Messaging, which will be enhanced by both the richer Presence Information available and the support for other more complex data types over and above the simple text of current systems. Not just person to person messaging: application to application messaging will also be possible, possibly using SOAP. The inherent extensibility of the architecture will allow new data formats to be supported.
Security and Privacy
Privacy
White Pages should be an opt-in subscription model, allowing the user the choice of whether or not to publish their information. The use of server and client-side filters would give users the ability to deny communications by user, domain, message type, or content, etc.
Authentication:
Simple username/password system. Digest authentication. Digital signatures. PKI
Encryption
PGP or S/MIME . . . authentication is a must but encryption, although provided, should be optional—user does not have to use the feature.
Secure Connections
SSL (Secure Socket Layer) can be used to create a secure connection between the client and the IMP Server to ensure that usernames, passwords and messages cannot be intercepted. IPSec
Transports
Protocols should be transport-independent: HTTP, WAP, SMS/MMS, etc. . . .
Namespace & Addressing
Globally Unique ID Or Domain-based: node@domain.com. Example: MyPersona@indirect.com
Directories and User Management
Along with a flexible messaging and presence system, an XML-based directory should be provided. As to account management, the server by default will allow every user to have full control over the creation of and management of their account. This includes passwords, and all presence, personal data and messaging aspects. Server administrators have full control over the rights allotted to each account, and can remove or limit those at any time.
PreAnswer.
Using the architecture described above current GSM Systems could support some form of Pre Answer:
Post
1. Before calling, a caller posts Caller Information onto the server (using, for example, SMS);
2. The caller then makes the call. Before it rings, the Callee' s phone makes a data call to the server and requests ‘Call Information’ for the Calling ‘Persona’.
3. This is then displayed, and the phone rings.
However, as well as being burdensome and particularly prone to latency problems, it has security implications as well—how to restrict only the Callee from accessing the Call information.
Supply
Another method would be to simply ‘handshake’ using messages (SMS, EMS, or MMS) to carry ‘Pre Answer’ information payload (based on a standard for such data).
1. To initiate a call, a caller sends the Callee a ‘Pre Answer’ message that the Callee's device recognises.
2. On receipt, the Callee's device alerts the Callee and displays the ‘Pre Answer’ information. The Callee can chose to ignore, accept or return a message.
3. If the Callee wishes to accept, then a return ‘Accept’ message is returned which the Caller's device recognises and promptly initiates a phone call to the Callee.
This is also burdensome and prone to latency problems, though not as stark as in the previous solution.
However, networks are moving towards wholly IP-based infrastructures and the adoption of the SIMPLE (SIP for Instant Messaging and Presence Leveraging Extensions) protocol as the standard interoperability protocol and the widespread support it enjoys (from, for example, AOL and Microsoft) may accelerate the process. This will provide an ideal infrastructure for rolling out such features as Pre Answer, the ability to move seamlessly from one type of session to another (data to voice for example), establishing conference calls, and so on.
In such an environment, and assuming SIP/SIMPLE and the architecture described above:
1. The caller would establish a communications session with the desired party. Initiating a session simply requires determining where on the network an invited party is at a particular moment (using the policies/mechanisms described above). Once the invited party is located, SIP delivers a description of the session (which among other data, includes the type of session desired, in this case ‘Voice’, and the ‘Pre Answer’ information) to which the person is being invited. The most common protocol used to describe sessions is the SDP (Session Description Protocol), described in RFC2327.
2. Once the person is located and the session description is delivered, SIP is used to convey the response to the session invitation (accept/reject). If accepted, the (voice) session becomes active.
3. SIP can be used to modify the session (e.g. switch to video, or data).
4. Finally, SIP can be used to terminate the session.
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A mobile telephone which can supply or post ‘pre-answer’ information which the device owner considers of relevance to a potential call recipient. This information enables a potential call recipient to be given useful information about a potential call before actually answering that call. The information is dynamic, unlike Caller ID information. Examples include: information about the subject of an intended voice call, a mood, a current activity, part or whole of a schedule of meetings or events, information about the urgency of an intended voice call, personal information, expected call duration, commercial inducements to a consumer to answer a call (special offers, loyalty points etc.), location information.
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REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application 61/137,450 filed Jul. 31, 2008, which is incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The technical field of the present invention is the field of mud-sills. Mud-sills are most often associated with scaffolding. The vertical and diagonal supports of scaffolding react their longitudinal force into the supporting ground. Most often, the ends of the supports are terminated with a screw (or like means for adjusting height) attached to a small-metal-plate. To distribute the force into a reasonable ground pressure, and to conform to 29 CFR 1926.451 (c)(2) and similar state requirements, the small-metal-plate found at the bottom end of scaffold legs is nailed to the top of a wooden board that contacts the ground. The wooden board is called a mud-sill.
[0004] The subject of this invention is an improved, reusable mud-sill that provides enhanced safety and that provides significant cost savings as compared to present wooden board mud-sills. The present invention's reusable mud-sill is intended to replace the conventional wooden-mud-sills. More particularly, the mud-sill of the present invention is able to capture the small-metal-plate without the use of tools and without the use of a wooden board, and is able to be reused many times. While the present invention is expected to have its major utility in conjunction with scaffolding, the present invention will also have utility with ladders and the like where their ground termination must not shift. The present invention makes use of the small-metal-plate that is most often essentially six inches square and that is conventionally found at the bottom end of scaffold legs. The present invention is also useful with small-metal-plates that are essentially five inches square.
[0005] 2. Background Art
[0006] FIG. 1 illustrates the prior-art. Three different linkages between scaffolding (not shown) and wooden-mud-sill 1 are shown on FIG. 1 . In most cases, scaffold-legs are essentially normal to small-metal-plate 10 as shown in the bottom two sub-figures of FIG. 1 . In one of those cases, fixed-scaffold-leg 14 is affixed directly to small-metal-plate 10 with a height-adjuster 18 being provided or, in the other case, fixed-scaffold-leg 14 is connected to small-metal-plate 10 by means of fixed-leg-coupler 12 with height-adjuster 18 being provided. The latter scheme of attachment of a fixed-scaffold-leg 14 to small-metal-plate 10 is also seen on FIGS. 2 & 3 . A variation, seen on the upper sub-figure of FIG. 1 , uses a pivotable-scaffold-leg 15 that uses cross-piece 16 within bushing 17 to provide for other than normal attachment to small-metal-plate 10 . The latter scheme of attachment of pivotable-scaffold-leg 15 to small-metal-plate 10 is also seen on FIG. 4 .
[0007] In each type of attaching a scaffold-leg to small-metal-plate 10 , the prior art includes nailing small-metal-plate 10 to wooden-mud-sill 1 . Scaffold-legs are usually threaded to facilitate manually adjusting the scaffold-leg's height using height-adjuster 18 . Information similar to that shown on FIG. 1 may be seen within FIG. 7 of U.S. Pat. No. 5,156,235.
[0008] A significant limitation of the prior-art involves the wooden boards that are used as mud-sills. Firstly, to be effective, the wooden boards must be fairly thick and long. Hence, the necessarily heavy wooden boards are awkward to transport and to wrestle into place. Secondly, the contact of the wooden boards with the ground causes than to absorb moisture, which increases their weight and which hastens their rotting. Thirdly, the tendency of the boards to rot and to be mud covered reduces the likelihood of being reused, which adversely impacts the cost of using wooden boards. Fourthly, having to nail the small-metal-plates to the wooden boards, and the accompanying need to remove the nails when moving the attendant scaffold, results in a significant labor and material cost.
[0009] Among the objectives of the present invention is the objective to overcome the listed limitations of the use of wooden board mud-sills. More specifically: the present invention is easy to transport and to place into position. It requires negligible effort, and no tools, to have the present invention capture small-metal-plates. Additionally, the present invention is expected to last for many years resulting in its expected amortized cost to be less than the alternatives and the use of the present invention eliminates the need to have a stock of nails and hammers, effecting further value.
BRIEF SUMMARY OF THE INVENTION
[0010] The preferred embodiment of the present invention is seen on the drawings as reusable mud-sill 30 . The preferred embodiment is made of steel although other materials would also be suitable. The invention captures a standard, six inch by six inch small-metal-plate 10 , found at the bottom of scaffolding, by inserting the small-metal-plate between side-blocks 22 and into front-overlapping-retainer 24 with the moveable-rear-overlapping-retainer 32 slid as far from the center of mud-sill 30 as allowed by the retaining-pins that are captive in retaining-pin's grooves 36 . The moveable-rear-overlapping-retainer 32 is then slid towards the center so that the small-metal-plate is captured. Locking-lever 38 is rotated into a mating groove, thus locking the small-metal-plate in place.
[0011] Optionally, the reusable mud-sill 30 may have its resistance to side movement enhanced by inserting spikes 40 into spike-holes 42 that are provided in the corners of the reusable mud-sill 30 . The spikes 40 are easily retracted with minimal damage when it is time to move mud-sill 30 .
[0012] When it is time to move the associated scaffolding, locking-lever 38 is rotated out of its groove, moveable-rear-overlapping-retainer 32 is slid away, and the small-metal-plate 10 is free. The reusable mud-sill 30 may now be moved to a new location or stored for future use. All of this is accomplished without the use of tools.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] FIG. 1 shows the prior art of nailing small-metal-plates to a wooden board mud-sill. Three conventional attachments of scaffold legs to small-metal-plates are shown.
[0014] FIG. 2 shows the preferred embodiment of the present invention in an un-locked state with a small-metal-plate in the process of being captured.
[0015] FIG. 3 shows the preferred embodiment of the present invention in a locked state with a small-metal-plate captured by the present invention.
[0016] FIG. 4 shows the preferred embodiment of the present invention in a locked state with a small-metal-plate that has a pivotable-scaffold-leg.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIGS. 2 and 3 advantageously show the preferred embodiment of the present invention. Reusable mud-sill 30 is made of steel and has permanently affixed to it side-blocks 22 and front-overlapping-retainer 24 . Since the reusable mud-sill 30 will be in contact with the earth, it is anticipated that it might advantageously be composed of marine-brass, stainless-steel, or of a strong plastic. The latter materials are expected to be more expensive than steel, but are also expected to be much more resistant to corrosion than is steel. It is advantageous to paint all of the present invention with a corrosion resistant paint.
[0018] Side-blocks 22 are spaced apart slightly more than six inches so as to accommodate a standard small-metal-plate 10 that is six inches square. Side-blocks 22 are essentially parallel to each other and front-overlapping-retainer 24 has its opening essentially normal to the side-blocks 22 . The inside height of front-overlapping-retainer 24 is slightly more than the expected thickness of a standard small-metal-plate 10 . The typical small-metal-plate 10 has a centrally located, fixed-leg-coupler 12 that is perpendicular to the small-metal-plate 10 and typically fixed-leg-coupler 12 contains cross-pin-orifice 13 used with a cross-pin to retain the bottom of a scaffold leg, or the like. FIG. 4 shows an alternative coupler associated with small-metal-plate 10 .
[0019] The permanent affixing of side-blocks 22 and front-overlapping-retainer 24 to the sill may be effected by welding, bolting, or other means such that the area between side-blocks 22 and front-overlapping-retainer 24 is kept clear to receive small-metal-plate 10 . Welding is the preferred method of affixing side-blocks 22 and front-overlapping-retainer 24 to reusable mud-sill 30 . An embodiment could be effected by casting or molding a single assembly that could include side-blocks 22 , front-overlapping-retainer 24 , and reusable mud-sill 30 .
[0020] However constructed, the assembly consisting of side-blocks 22 , front-overlapping-retainer 24 , and reusable mud-sill 30 is augmented to accommodate moveable-rear-overlapping-retainer 32 . The augmentation includes cutting (or otherwise effecting) a groove within reusable mud-sill 30 that will align with locking-lever's groove 39 when moveable-rear-overlapping-retainer 32 captures small-metal-plate 10 and that will receive locking-lever 38 when locking-lever 38 is rotated into a locking position. Optionally, one may augment the assembly consisting of side-blocks 22 , front-overlapping-retainer 24 , and reusable mud-sill 30 by providing spike-holes 42 in the corners of reusable mud-sill 30 . Additional augmentation of the assembly consisting of side-blocks 22 , front-overlapping-retainer 24 , and reusable mud-sill 30 involves providing retaining-pins as described next.
[0021] Side-blocks 22 and front-overlapping-retainer 24 will retain small-metal-plate 10 in three horizontal directions, which includes sideways and upwards. Moveable-rear-overlapping-retainer 32 is used to affix small-metal-plate 10 in the fourth horizontal direction, and in the vertical direction, on a releasable basis. Moveable-rear-overlapping-retainer 32 and the mud-sill contain several cooperating parts. To effect the ability of the invention selectively to affix and to release small-metal-plate 10 , moveable-rear-overlapping-retainer 32 is able captively to slide towards or away from the center of reusable mud-sill 30 . The captive sliding capability is effected by extending two retaining-pins into retaining-pin's grooves 36 that are on each side of moveable-rear-overlapping-retainer 32 and that are parallel to each other. The above-surface ends of the retaining-pins are visible on the drawings as retaining-pin's heads 35 . It is not possible to show the retaining-pins themselves as they are within retaining-pin's groove 36 . The retaining-pins may be effected with bolts screwed down into the sill or with metal dowels extending upward through the sill. However effected, the retaining-pins have a width less than the width of retaining-pin's groove 36 and are surmounted with retaining-pin's head 35 that prevents moveable-rear-overlapping-retainer 32 from being detached from the mud-sill.
[0022] Alternatively, the preferred embodiment of the present invention may be described as an essentially flat-plate that is significantly larger than the small-metal-plate upon the top of which side-blocks 22 , front-overlapping-retainer 24 , and moveable-rear-overlapping-retainer 32 are placed. In the preferred embodiment, the essentially flat-plate is about 12 inches square and this size is included in what is meant by significantly larger than the small-metal-plate.
[0023] The side-blocks 22 are expected to be essentially parallel to each other, separated by slightly more than six inches, and having a height of at least twice the expected thickness of the small-metal-plate. Front-overlapping-retainer 24 is expected to be essentially normal to side-blocks 22 with an opening that faces towards the center of the flat-plate and that is slightly greater than the expected thickness of the conventional small-metal-plate. The moveable-rear-overlapping-retainer 32 is able captively to slide on the flat plate, has an opening that faces the opening of the front-overlapping-retainer 24 , is essentially normal to side-blocks 22 , and that is slightly greater than the expected thickness of the conventional small-metal-plate.
[0024] A rotatable locking-lever 38 is mounted on moveable-rear-overlapping-retainer 32 such that locking-lever 38 may be rotated into locking-lever's groove 39 that is within the flat-plate when the small-metal-plate is within and captured by moveable-rear-overlapping-retainer 32 .
[0025] It is apparent that the flat-plate and its surmounted components may be made of steel and numerous other materials. It is also apparent that the shown, described and preferred side-blocks 22 , front-overlapping-retainer 24 , moveable-rear-overlapping-retainer 32 and its way of being captive and of being able to be locked, may be effected by other schemes that will apparent to one skilled in the art.
[0026] To use the present invention, one places reusable mud-sill 30 directly below a leg of a scaffold having a small-metal-plate 10 , rotates locking-lever 38 out of engagement with locking-lever's groove 39 (and thus out of engagement with the cooperating groove in reusable mud-sill 30 that is not possible to be seen), slides moveable-rear-overlapping-retainer 32 away from the center of reusable mud-sill 30 , places small-metal-plate 10 onto reusable mud-sill 30 , slides an edge of small-metal-plate 10 under the overhang of front-overlapping-retainer 24 , slides moveable-rear-overlapping-retainer 32 so that it overlaps small-metal-plate 10 , and rotates locking-lever 38 into locking-lever's groove 39 , thus capturing small-metal-plate 10 . These steps are reversed when it is time to move the associated scaffolding and the reusable mud-sills 30 . Optionally, one may place spikes 40 within spike-holes 42 so as to enhance the resistance of reusable mud-sill 30 to motion side-ways. Such spikes need not be driven flush with reusable mud-sill 30 .
[0027] FIG. 2 shows the present invention with moveable-rear-overlapping-retainer 32 unlocked and moved towards the outer edge of the mud-sill so that reusable mud-sill 30 can receive small-metal-plate 10 . FIG. 3 shows the present invention with moveable-rear-overlapping-retainer 32 moved away from the edge of the mud-sill so as to capture small-metal-plate 10 and FIG. 3 shows locking-lever 38 rotated about pivot-pin-support 34 using pivot-pin 37 to engage locking-lever's groove 39 and a groove below locking-lever's groove 39 that is in the mud-sill. FIG. 3 also shows that moveable-rear-overlapping-retainer 32 is kept from leaving the mud-sill by retaining-pin's heads 35 that are larger than the width of retaining-pin's groove 36 .
[0028] The information in FIG. 4 differs from that in FIG. 3 only in that FIG. 4 shows the use of an optional, but conventional, way that small-metal-plate 10 is coupled to a leg of a scaffold. In FIG. 4 , pivotable-scaffold-leg 15 has an upward section threaded and has its height adjustable by height-adjuster 18 . Pivotable-scaffold-leg 15 is able to be pivoted from being perpendicular to small-metal-plate 10 by pivot-angle 19 . That feature is effected by pivotable-scaffold-leg 15 having a lower cross-piece 16 normal to pivotable-scaffold-leg 15 that is captive within bushings 17 . It is to be apparent that variations exist for effecting the coupling of the leg of a scaffold with small-metal-plate 10 and that reusable mud-sill 30 is able to capture the variations. Small-metal-plates 10 that are five inches square have been occasionally experienced and it has been found that the reusable mud-sill 30 described herein captures the smaller small-metal-plate 10 in a satisfactory manner.
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A reusable mud-sill to replace the conventional wooden-mud-sills and to capture without the use of tools the small-metal-plate conventionally found at the bottom of scaffold legs. Mud-sills are used to interface the bottom ends of scaffold legs, or the like, to the ground and to provide reasonable ground pressure while inhibiting side movement of a leg. The reusable mud-sill captures a small-metal-plate with two fixed opposing side-blocks, a fixed overlapping-retainer, and a sliding overlapping-retainer that may be locked to the reusable mud-sill when the conventional small-metal-plate has been captured. The cooperating, capturing parts are all centrally placed on the top of a flat-plate that is significantly larger than the small-metal-plate.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns an automotive data device, such as an audio system, into which a plurality of recording and playback devices are integrally incorporated, and in particular it relates to an automotive data device wherein the device main unit is configured by vertically stacking recording and playback devices used for relatively thin data recording media, such as CDs, MDs and IC cards, together with recording and playback devices used for relatively thick data recording media, such as compact cassette tapes, DATs and video tapes, and other such devices, the front of this device main unit being covered by a front panel that can be opened and closed.
2. Description of Related Art
One type of conventional automotive data device that incorporates a recording and playback device used for a fixed type of data recording media is one wherein a recording and playback device is provided inside the device main unit, the media insertion slot of this recording and playback device is formed in the front of the device main unit, and a front panel that covers the media insertion slot is provided at the front of this device main unit, and it is configured so that the media insertion slot is opened and closed by swivelling this front panel.
On the other hand, with the diversification of data recording media in recent years, there is a demand for automotive data devices for mounting in vehicles that deal with a plurality of data recording media, and thus various types of automotive data devices that incorporate two appropriately selected recording and playback devices into the device main unit have recently been proposed and implemented. Although the exterior dimensions of automotive data devices are generally laid down according to DIN specifications, it is for example possible to provide two recording and playback devices at the top and bottom of the device main unit as shown in FIG. 13, since the 2 DIN specifications have dimensional leeway, particularly in the vertical direction.
In this case, FIG. 13 shows a typical example wherein a CD player 20 for disks (CDs) is provided at the top, and a cassette tape player 30 for cassettes (C cassette tapes) is provided at the bottom of device main unit 10. Front panel 40 is provided at the front of this device main unit 10, and simultaneously covers the media insertion slot 21 of CD player 20 and the media insertion slot 31 of cassette tape player 30. A display such as liquid crystal display 41 and user operating switches or controls are provided at the front part of this front panel 40.
To release each of the media insertion slots 21 and 31 of CD player 20 and cassette tape player 30 by swivelling this front panel 40, front panel 40 must at least be moved down relative to device main unit 10. That is, if it is configured so that front panel 40 is moved up relative to device main unit 10 and swivelled through 90 degrees or so, since the viewpoint of passengers in the vehicle is higher than the automotive data device, media insertion slots 21 and 31 are obstructed from the viewpoint of passengers in the vehicle by front panel 40 and are difficult to see, even when both media insertion slots 21 and 31 are fully released. To resolve this inconvenience it would be necessary to swivel front panel 40 by as much as 180 degrees or so, but in this case the operating range of front panel 40 becomes very large, which is inconvenient.
It is thus preferable that front panel 40 is swivelled so as to move down relative to device main unit 10. This style of swivelling encompasses the style whereby, as shown in FIG. 14, front panel 40 is simply swivelled with the bottom end of front panel 40 as a swivelling axis (so that its front part points down), and the style shown in FIG. 15 whereby link 40a that supports the bottom end of front panel 40 is pushed out to the front, thereby moving the bottom part of front panel 40 forward and moving the top part of front panel 40 down, and thus front panel 40 swivels with the bottom end of front panel 40 as a swivelling axis (so that its front part points up).
However, as shown in FIG. 14 and FIG. 15, in a conventional automotive data device provided with two recording and playback devices at the top and bottom of the device main unit and provided with a swivelling style of front panel at the front of this device main unit, there are the following problems. That is, when ejecting and inserting (loading) disk 2 or cassette 3, which are the data recording media for CD player 20 and cassette tape player 30, it is necessary to swivel front panel 40 through about 90 degrees.
In this case, in the style of FIG. 14, when front panel 40 is swivelled so that its front part faces down, the results of swivelling front panel 40 through about 90 degrees is that the front part of front panel 40 becomes completely impossible for the passengers of the vehicle to see. In this state, it is difficult to view or operate displays such as liquid crystal display 41 and operating switches provided on the front part of front panel 40, making it awkward to use and difficult to operate.
On the other hand, in the style of FIG. 15, when front panel 40 is swivelled so that its front part faces up, since the front part of front panel 40 comes close to the media insertion slot 31 of the lower cassette tape player 30, cassette 3 and the front part of front panel 40 come very close together when ejecting or loading cassette 3, and are liable to come into contact. In this case, it is possible that the display such as liquid crystal TV 41 and operating switches provided on the front part of front panel 40 wll be damaged. Also, when a disk player such as CD player 20 is provided at the bottom of device main unit 10, the signal recording surface of the disk may become damaged.
Furthermore, in a conventional automotive data device provided in this way with a plurality of recording and playback devices at the top and bottom of the device main unit, it is necessary to swivel front panel 40 through a large angle of 90 degrees or so every time a data recording media is ejected or loaded as mentioned above. The fact that front panel 40 is swivelled through a large angle of 90 degrees or so every time a data recording media is ejected or loaded in this way increases the time and effort needed for ejecting and loading operations and makes the device difficult to operate. Also, in an automotive data device provided with a plurality of recording and playback devices, since the dimensions of front panel 40 itself are large, the amount by which this front panel 40 projects from device main unit 10 is considerably large when front panel 40 is swivelled. This large projection of front panel 40 increases the possibility of it interfering with various devices inside the car (such as the gear shift lever) and with the passengers, and this is also undesirable in that inter alia, it leads to limitations on the positions in which the automotive data device can be installed.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention has been proposed in order to resolve the above-mentioned problems of the prior art, and it aims to provide an automotive data device whereby the front part of the front panel can be viewed and operated when ejecting and inserting data recording media, wherein damage to the front panel and to the data recording media can be prevented, and wherein the installable range of the device can be enlarged by decreasing the amount of swivel and the amount of projection of the front panel, and which is highly convenient to use, easy to operate, reliable, and has good positioning flexibility.
To achieve the abovementioned objective, the present invention is an automotive data device characterized in that, in particular, it is configured so that the front panel is swivelled in two directions and respectively releases the media insertion slots by swivelling in both these directions, and in that it is configured so that this swivelling of the front panel is controlled according to instructions for attachment and removal issued to the recording and playback means.
First, the automotive data device according to the invention, like a conventional automotive data device, is equipped with a device main unit, a plurality of recording and playback means provided vertically stacked inside this device main unit, and a plurality of media insertion slots provided for each of these plurality of recording and playback means, and which are respectively formed at the front of device main unit. Furthermore, the front of device main unit is equipped with a front panel provided so as to cover a plurality of media insertion slots, and a swivel means that swivels this front panel so that this front panel releases the plurality of media insertion slots. The automotive data device according to the present invention is also characterized in that, in an automotive data device with this configuration, it furthermore has the following configuration.
A swivel means is configured with a motor and linkage system so as to swivel the front panel in two directions so that its front part points both up and down, and in that it is provided with a control means that controls the starting and stopping of this swivel means. In this case, the swivel means is configured so as to swivel the front panel in a first direction in which its front part points up, and in a second direction in which its front part points down, respectively.
The control means is further configured so that when instructions for the attachment/removal of media are issued to a recording and playback means at the top of the plurality of recording and playback means, the front panel is swivelled in said first direction by starting said swivel means. This control means is also configured so that when instructions for the attachment/removal of media are issued to a recording and playback means at the bottom of said plurality of recording and playback means, the said front panel is made to swivel in said second direction by starting said swivel means.
When ejecting inserting data recording media from a recording and playback means (recording and playback device), the swivel means is started by the control means according to an instruction to attach or remove media to/from this recording and playback device, whereby the front panel automatically swivels in the first or second direction, and thus passengers of the vehicle can eject and insert data recording media easily without having to swivel the front panel.
In particular, when resecting or inserting data recording media from a recording and playback device at the top, the front panel swivels in the first direction and its front part points up, and thus the passengers of the vehicle can continue to view and operate displays such as the liquid crystal TV and operating switches provided at the front part of this front panel, in the same way as before swivelling.
On the other hand, when ejecting or inserting a data recording media from/into a recording and playback device at the bottom, the front panel swivels in the second direction and its front part points down, so that there is no possibility of the data recording media touching the front part of the front panel. Accordingly, there is no danger of damaging the operating switches and displays such as a liquid crystal TV provided on the front part of the front panel, and there is no danger of damaging the data recording surface of a disk even when a disk player such as a CD player is provided as the lower recording and playback device.
Thus, by automatically switching the swivel direction of the front panel according to the position of the media insertion slot to/from which the data recording media is to be attached/removed, it is possible to view and operate the front part of the front panel when ejecting and inserting data recording media, and it is possible to prevent damage to the front panel and the data recording media, to a greater extent than in the case where the swivel direction of the front panel is always in the same direction when attaching and removing data recording media. Accordingly, it can be made more convenient to use, easier to operate, and more reliable.
The swivel means is configured so that, so that when swivelling said front panel in said first direction, the top end of this front panel is pulled down below at least one media insertion slot of the plurality of media insertion slots, and to a position above at least one media insertion slot. This swivel means is also configured so that, when swivelling this front panel in second direction, the back part of this front panel is dropped to a position below the lowermost media insertion slot of the said plurality of media insertion slots.
When ejecting or inserting a data recording media from to a recording and playback device at the top, the front panel is only swivelled by the minimum amount necessary to release the media insertion slot of this top recording and playback device, and thus compared to the case where all the media insertion slots are released, it is possible to reduce the amount by which the front panel is swivelled and the amount by which it projects. As a result, in addition to being able to shorten the time required for ejecting and inserting data recording media, it is also possible to prevent damage to the front panel, and the installable range of the device is also increased. Accordingly, it is possible to increase its convenience of use, its ease of operation and its reliability, and it also has excellent positioning flexibility.
The control means is configured so as to hold said front panel in the swivelled state in said second direction without starting said swivel means when an instruction for the attachment/removal of media is issued to a recording and playback means at the top of said plurality of recording playback means that is in a state where said front panel is swivelled in said second direction.
Ejecting or inserting data recording media from to a recording and playback device at the top, the media insertion slot of the recording and playback device at the top is usually released by swivelling the front panel in the first direction, but in the case where the front panel is swivelled in the second direction and all the media insertion slots in a released state, there is no point in swivelling the front panel in the opposite direction from this state. Conversely, it is possible to eject and insert data recording media with from/into the upper recording and playback device both quickly and effectively with the front panel left rotated in the second direction without unnecessary swivelling. Accordingly, it is possible to further enhance the convenience of use and ease of operation.
Since a disk player that is used for disks--which are relatively thin data recording media is situated at the top, it is possible to reduce the amount of swivel and the amount of projection in the state where the front panel is swivelled in the first direction to release the media insertion slot of this disk player. As a result, it is not only possible to shorten the time required for disk ejecting and insertion, but it is also possible to prevent damage to the front panel and to enlarge the installable range of the device. Accordingly, it is possible to further enhance the convenience of use, the ease of operation, and the reliability, and it also has excellent positioning flexibility.
That is, when ejecting a small-diameter disk from media insertion slot, since the amount by which this small-diameter disk projects is small, it is generally difficult to take the disk out. In particular, when the disk player is situated at the top, in the state where the front panel is swivelled in the first direction to release the media insertion slot of this disk player, since this media insertion slot is extremely close to the top end of the front panel, it is made even more difficult to take out the small-diameter disk. Conversely, the front panel is swivelled in the second direction when ejecting the small-diameter disk, making it easier to take out the small-diameter disk since it is adequately separated from the media insertion slot of the disk player, and it is possible to further enhance the convenience of use and ease of operation.
The swivel means is configured so as to retract the bottom part of this front panel inside said device main unit when said front panel is swivelled in said second direction. That is, when the front panel is swivelled in the second direction, from the relationship whereby all the media insertion slots are released, the amount by which the front panel swivels is increased and, concomitant with this, the amount of projection of the front panel also increases. Conversely, when the front panel is swivelled in the second direction, it is possible to reduce the amount of projection of the front panel in the state where it is swivelled in the second direction by retracting the bottom part of the front panel inside the device main unit. As a result, it is not only possible to prevent damage to the front panel, but it is also possible to increase the installable range of the device. Accordingly, it is possible to further increase the convenience of use, ease of operation and reliability, and the flexibility of positioning is also enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings.
FIG. 1 is a block diagram showing the configuration of an automotive data device according to a first embodiment of the present invention;
FIG. 2 is an oblique view showing the closed state of the panel drive unit in FIG. 1;
FIG. 3 is a side view showing the first open state of the panel drive unit in FIG. 1;
FIG. 4 is a side view showing the second open state of the panel drive unit in FIG. 1;
FIG. 5 is a figure showing a specific example of the panel drive unit in FIG. 1; in particular, a plan view showing the closed state;
FIG. 6 is a side view of FIG. 5;
FIG. 7 is a side view showing the first open state of the panel drive unit of FIG. 5;
FIG. 7 is a side view showing the second open state of the panel drive unit of FIG. 5;
FIG. 9 is a flow chart showing the operating procedure of the microcontroller when an eject/loading instruction is received, showing the portion until recognition of the instruction signal;
FIG. 10 is a flow chart showing the portion relating to control of the front panel for the CD player and control of the CD player in the operating procedure of the microcontroller when an eject/loading instruction is received in the device of FIG. 1;
FIG. 11 is a flow chart of the operating procedure of the microcontroller in the device of FIG. 1 when eject/loading instruction is received, showing the portion relating to control of the front panel for the cassette tape player and control of the cassette tape player;
FIG. 12 is a flow chart showing part of the microcontroller operating procedure when an eject/loading instruction is received in an automotive data device according to the second embodiment of the present invention;
FIG. 13 is a figure showing the configuration of one example of a conventional automotive data device;
FIG. 14 is a figure showing the basic principle of one example of the front panel swivel method of a conventional automotive data device;
FIG. 15 is a figure showing the basic principle of another example of the front panel swivel method of a conventional automotive data device;
FIG. 16 is an explanatory diagram showing the dead space formed at the end part of the device main unit by applying the present invention;
FIG. 17 is an explanatory diagram showing the dead space formed at the end part of the device main unit in one example of a swivel method differing from the present invention; and
FIG. 18 is an explanatory diagram showing the dead space formed at the end part of the device main unit in another example of a swivel method differing from the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the general principles of the present invention have been defined herein specifically to provide an improved automotive data device, such as an audio player that can reproduce sound from different formats of recording media.
Incidentally, it is necessary to provide a dead space for retraction purposes at the front of the device main unit in order to configure it so that the front panel can be retracted inside the device main unit. In this case, as shown in FIG. 16, since the bottom part of front panel 40 (which includes an axis for swivelling in the second direction) is retracted, it is sufficient to provide dead space 10 conformant with the amount of retraction in just one part at the lower front part of device main unit 10, and thus it does not limit the configuration of housing.
On the other hand, when the front panel is swivelled in the first direction, a configuration whereby the top part of this front panel is retracted inside the device main unit can also be considered. However, in this case, from the relationship whereby the top part of the front panel is moved down, a large dead space 10a has to be provided pointing down from the top part of device main unit 10, as shown in FIG. 17. Also, when retraction dead space 10a at the bottom is used unaltered as shown in FIG. 16, the amount of projection of front panel 40 becomes very large when front panel 40 is moved down as shown by the dotted line in FIG. 18. In particular, when the front panel is swivelled in the first direction, since it only has to swivel by the amount needed to release the previously set upper media insertion slot, it is possible to substantially reduce the amount of swivel and the amount of projection of the front panel compared with the case where it is swivelled in the second direction to release all the media insertion slots. Therefore, even supposing it is configured so as to retract the top part of this front panel inside the device main unit when swivelling in the first direction, this is inconvenient in that a large amount of dead space is required to retract the front panel, and the operational effect of the case where the bottom part is retracted when swivelling in the second direction is not obtained.
As a first embodiment of the present invention, a specific embodiment is described as applied to an automotive data device provided with a CD player at the top of the device main unit, and a cassette tape player for compact (C) cassettes at the bottom with reference to FIGS. 1 through 9. Here, FIG. 1 is a block diagram schematically illustrating the overall configuration of the automotive data device in the form of an audio player unit according to the present embodiment, FIGS. 2 through 4 show the three typical states of the panel drive unit of the device of FIG. 1, where FIG. 2 is an oblique view of the closed state, FIG. 3 is a side view of the first open state, and FIG. 4 is a side view of the second open state. Also, FIGS. 5 through 8 show an example of the specific configuration of the panel drive unit of the device, where FIG. 5 is a plan view of the closed state, FIG. 6 is a side view of the closed state, FIG. 7 is a side view of the first open state, and FIG. 8 is a side view of the second open state. Furthermore, FIGS. 9 through 11 are flow charts showing the operating procedure of the microcontroller during eject and loading instructions in the device, where FIG. 9 is the portion from the input of instructions to their discrimination, FIG. 10 is the portion relating to CD player control and front panel control for the CD player, and FIG. 11 is the portion relating to cassette tape player control and front panel control for the cassette tape player.
As shown in FIG. 1, CD player 20 for disks (CDs) and cassette tape player 30 for cassettes (C cassette tapes) are provided, vertically stacked inside device main unit 10, in the automotive data device according to the present embodiment. Each of the media insertion slots 21 and 31 of this CD player 20 and cassette tape player 30 are respectively formed in the front of device main unit 10. Front panel 40, which simultaneously covers the media insertion slots 21 and 31 of CD player 20 and cassette tape player 30, is provided at the front of this device main unit 10, and a liquid crystal display 41 and operating switches 42 thereof (see FIG. 2) are provided at the front part of this front panel 40.
Here, CD player 20 is a player that can directly load both large-diameter disks (12 cm CDs) and small-diameter disks (8 cm CDs); such players are widely known. Also, this CD player 20 is equipped with disk eject/loading mechanism 22 for ejecting and loading disk 2, and drive motor 23 for driving this disk eject/loading mechanism 22. CD player 20 is also equipped with disk insertion detection sensor 24 for detecting the insertion of disk 2, disk eject detection sensor 25 for detecting the ejection of disk 2, and disk size discrimination sensor 26 for discriminating the size of disk 2. These sensors 24 through 26 can be appropriately designed using existing technology, such as light sensors and microswitches.
Next, cassette tape player 30 is situated with a slight inclination from front to back so that its media insertion slot 31 is positioned higher up than it would be in the horizontal case, so as to reduce the amount of swivel of front panel 40. This cassette tape player 30 is equipped with cassette eject/loading mechanism 32 for ejecting and loading cassette 3, and drive motor 33 for driving this cassette eject/loading mechanism. Cassette tape player 30 is also equipped with cassette detection sensor 34 for detecting the section and insertion of cassette 3. Like the sensors 24 through 26, this sensor 34 uses existing technology.
Also, in the present embodiment, panel drive unit 43 for driving front panel 40 is provided in this front panel 40, and this panel drive unit 43 is equipped with panel drive mechanism 44 for swivelling front panel 40 in two directions, and panel drive motor 45 for driving this front panel mechanism 44. Here, panel drive mechanism 44 is configured so as to assume a first open position P 1 shown in FIG. 3 by swivelling front panel 40 in first direction D 1 from closed position P 0 shown in FIG. 2, and second open position P 2 shown in FIG. 4 by swivelling in a second direction D 2 , and is also configured to return front panel 40 to a closed position P 0 from first or second open position P 1 or P 2 .
Here, closed position P 0 of front panel 40 is a vertical position that blocks the media insertion slots 21 and 31 of CD player 20 and cassette tape player 30. Also, first open position P 1 is an upwardly inclined position that only releases media insertion slot 21 of CD player 20 while covering media insertion slot 31 of cassette tape player 30, the angle of this inclination being adjustable between closed position P 0 and the limit of the swivel range in first direction D 1 . Furthermore, second open position P 2 is a horizontal position wherein the media insertion slots 21 and 31 of CD player 20 and cassette tape player 30 are both released, and coincides with the limit of the swivel range in second direction D 2 .
Furthermore panel chive unit 43 is equipped with panel position detection sensor 46 that detects the position of front panel 40. The position of front panel 40 can be detected by this panel position detection sensor 46 using suitable existing technology. For example, it can easily be done using a configuration whereby the operating position of panel drive mechanism 44 is detected by panel position detection sensor 46, and it is also possible to use a configuration whereby the position of a part of front panel 40 is detected by panel position detection sensor 46.
Also, in the present embodiment, device main unit 10 is provided with operating/control unit 50. This operating/control unit 50 is provided with microcontroller 51 as a control means for controlling the device main unit 10, and is also provided with disk eject/loading button 52 and cassette eject/loading button 53 for respectively issuing eject and loading instructions to CD player 20 and cassette tape player 30. Also, display 54 is provided to perform operational display and control display for CD player 20, cassette tape player 30 and panel drive unit 43, and also to display the error when an error is judged to have occurred.
Here, the microcontroller 51 is set up to receive detection signals from each of the sensors 24 through 26 and 34 of CD player 20 and cassette tape player 30, and to control the starting and stopping of each drive motor 23 and 33 according to each instruction signal from disk eject/loading button 52 and cassette eject/loading button 53. The technology whereby microcontroller 51 is used in this way to automatically perform ejection and loading of CD player and cassette tape player 30 is a known technology, but in the present embodiment microcontroller 51 also performs drive control of front panel 40. That is, microcontroller 51 not only identifies the position of front panel 40 by receiving a detection signal from panel position detection sensor 46, but is also set up to control the starting and stopping of panel drive motor 45 according to each instruction signal from disk eject/loading button 52 and cassette ejection/loading button 53.
Although not illustrated for the sake of clarity, note that CD player 20 is actually equipped with various means besides disk eject/loading mechanism 22 in order to replay the data recorded on disk 2, i.e., disk drive and optical pick-up mechanisms, a signal processing device, and so on. Similarly, cassette tape player 30 is provided with various means beside cassette eject/loading mechanism 32 in order to play back the data recorded on C cassette tape 3, i.e., a tape drive, a playback head, a signal processing device, and so on. Similarly, operating/control unit 50 is provided with various displays besides display 54 and various operating buttons besides eject/loading buttons 52 and 53 in order to operate CD player 20 and cassette tape player 30.
Panel drive unit 43 of the automotive data device according to the present embodiment is specifically configured as shown, for example, in FIG. 5 and FIG. 6. As shown in FIG. 5 and FIG. 6, panel drive motor 45 and slide member 60, which is driven by this panel drive motor 45 and swivels front panel 40, are provided at the bottom inside chassis 11 of device main unit 10. This slide member 60 is coupled to panel drive motor 45 by rack 61 provided on a part thereof, via gears 62, and is driven to and fro in a reciprocating fashion in the direction of arrow X in the figure by the forward and reverse drive power of panel drive motor 45.
The periphery of this slide member 60 is folded over so as to confer strength and is formed into ribs 60a, 60b and 60c. The end parts of ribs 60a and 60b on the left and right sides support drive pins 63, which are provided on both sides at the bottom of front panel 40, with freedom to pivot. This slide member 60 is equipped with guide slots 64, of which one extends horizontally to the front and rear in the main body of the slide member and two others are provided in ribs 60a and 60b on either side, and is configured so as to be guided to and fro in the horizontal direction by these guide slots 64 and by guide pins 65 which are inserted into each guide slot 64 and fixed to chassis 1. Accordingly, by driving panel drive motor 45 forward and backward, slide member 60 is made to undergo reciprocal motion toward the front and rear guided by guide slots 64 and guide pins 65 to form a linkage system with the front panel 40, and the bottom part of front panel 40 is made to undergo reciprocal motion forward and backward via drive pins 63.
In the figures, 66 represents follower pins provided at both sides of the central part of front panel 40, and each of the follower pins 66 is supported with freedom to slide inside each guide slot 68 of each guide plate 67 respectively provided at both sides of front panel 40. Here, each guide plate 67 is fixed to the outer casing (not illustrated). Each guide slot 68 is formed into a V shape at the underside of each guide plate 67, the upper parts of guide slots 68 being formed perpendicularly, and the lower parts of guide slots 68 inclined in a shape that slopes down to the rear. These follower pins 66, along with the abovementioned drive pins 63, configure a 4-point support for front panel 40, and front panel 40 is supported at 4 points with respect to device main unit 10.
On the other hand, 70a and 70b in the figures are limit switches provided on chassis 11 as part of panel position detection sensor 46. These limit switches 70a and 70b stop front panel 40 by mechanically detecting the position of front panel 40 via slide member 60, and are thus respectively equipped with actuators 71a and 71b, which mutually project rearward and are provided to respectively define the limits at both sides of the swivel range of front panel 40. Also, at the top end of rib 60a of slide member 60, operating tabs 72a and 72b are respectively provided by folding back at one place to press onto each actuator 71a and 71b.
That is, each limit switch 70a and 70b stops panel drive motor 45 of panel drive unit 43 when actuators 71a and 71b are pressed down by operating tabs 72a and 72b of slide members 60, whereby front panel 40 is stopped. Thus, limit switches 70a and 70b and operating tabs 72a and 72b are situated in a relationship such that limit switch 70a at the rear operates when front panel 40 has reached the limit of the swivel range in first direction D 1 , and limit switch 70b at the front operates when front panel 40 has arrived at the limit of the swivel range in second direction D 2 (second open position P 2 in FIG. 8).
Furthermore, 73 in the figures is a photoswitch provided on chassis 11 as a part of panel position detection sensor 46. This photoswitch 73 is provided to optically detect the position of front panel 40 via slide member 6 when this front panel 40 has arrived at closed position P 0 shown in FIG. 6 or first open position P 1 shown in FIG. 7, and to stop the front panel 40. Also, a perforated line 74 is provided at the back of rib 60b of slide member 60.
That is, photoswitch 73 is made to stop panel drive motor 45 of panel drive unit 43 by detecting perforated line 74 of slide member 60, and thereby stop front panel 40. Photoswitch 73 and perforated line 74 are situated in a relationship such that photoswitch 73 counts the holes in perforated line 74 while front panel 40 is swivelling in first direction D 1 from closed position P 0 in FIG. 6. In this case, by arbitrarily setting the total number of holes in perforated line 74 at which it is stopped by photoswitch 73, it is possible to set first open position P 1 of front panel 40 arbitrarily between the limits of closed position P 0 and the limit of the swivel range in first direction D 1 .
In an automotive data device according to the first embodiment and having the above configuration front panel 40 is controlled during ejecting/loading by microcontroller 51 of control/operating unit 50 according to the procedure shown in FIGS. 9 through 11.
As shown in FIG. 9, either disk eject/loading button 52 or cassette eject/loading button 53 of operating/control unit 50 is operated by a passenger in the vehicle, an eject/loading instruction signal is issued to CD player 20 or cassette tape player 30, and when this instruction signal is input to microcontroller 51, microcontroller 51 begins a control operation of front panel 40 on condition that front panel 40 is stationary.
When an eject/loading instruction signal is input as mentioned above, microcontroller 51 first judges whether or not front panel 40 is stopped (in operation?), shown as step 101 in FIG. 9. At this step 101, when microcontroller 51 has judged that front panel 40 has not stopped, it stands by for a specific time interval according to the required time from when a control signal for driving is output to panel drive unit 43 until when a stationary position detection signal is input. After standing by, microcontroller 51 judges whether or not front panel 40 has stopped (in operation?) at step 103.
At step 103, when front panel 40 has been judged to have stopped, it is considered that the driving of front panel 40 has been appropriately performed. Accordingly, when microcontroller 51 has judged that front panel 40 has stopped at step 101 or step 103, it proceeds to step 104, and at step 104 it determines whether or not the input eject/loading instruction signal is a disk instruction relating to CD player 20 (or whether it is a cassette instruction relating to cassette tape player 30).
On the other hand, when front panel 40 has been judged not to have stopped at step 103, it is considered that some kind of error has occurred in panel drive unit 43 and that the driving of front panel 40 has not been appropriately performed. Accordingly, in this case, microcontroller 51 proceeds to step 105, and at this step 105 an error signal is output and the error in panel drive unit 43 is displayed on display 54.
At step 104 in FIG. 9, when the instruction signal has been judged to be a disk instruction relating to CD player 20, microcontroller 51 proceeds to step 106 shown in FIG. 10 via link A, and operations to control front panel 40 for CD player 20 are performed by the operations in steps 106 through 113 for controlling the front panel for CD player operation.
At step 106, microcontroller 51 judges whether or not front panel 40 is in first open position P 1 . Note that this judgement of the position of front panel 40 is performed at this step 106 and at every step relating to judgement of the position of front panel 40 mentioned in the following, based on detection signals from the abovementioned limit switches 70a and 70b, photoswitch 73, and other panel position detection sensors 46.
Then, at step 106, when front panel 40 is judged to be in first open position P 1 , microcontroller 51 proceeds to step 112 and holds front panel 40 in first open position P 1 by stopping panel drive motor 45 of panel drive unit 43. That is, when an eject and loading instruction is issued to the disk, front panel 40 is kept in its present position if front panel 40 is already in a first open position P 1 .
On the other hand, at step 106, when it is judged that front panel 40 is not in first open position P 1 , microcontroller 51 determines at the following step 107 whether or not front panel 40 is in a second open position P 2 . That is, when an eject/loading instruction is issued to the disk, front panel 40 is also left in its position when front panel 40 is already in second open position P 2 .
At step 107, when it is judged that front panel 40 is in second open position P 2 , microcontroller 51 proceeds to step 113 and front panel 40 is held in second open position P 2 by stopping panel drive motor 45 of panel drive unit 43. Conversely, at step 107, when it is judged that front panel 40 is not in second open position P 2 , microcontroller 51 determines at the following step 108 whether or not the front panel 40 is in closed position P 0 .
At step 108, when front panel 40 is judged not to be in a closed position P 0 , it is considered that front panel 40 is stationary at a position other than the 3 specified positions P 0 , P 1 and P 2 , and that some kind of error has occurred in panel drive unit 43. Accordingly, in this case, microcontroller 51 proceeds to step 105 in FIG. 9 via link C, and at this step 105 an error signal is output and the error in panel drive unit 43 is displayed on display 54. Note that it is also possible to omit this step 108 and go directly to step 109 when a negative response is obtained at step 107.
Conversely, at step 108, when it is judged that front panel 40 is in closed position P 0 , it is considered that the driving of front panel 40 has been appropriately performed. Accordingly, in this case microcontroller 51 proceeds to the following step 109, panel drive motor 45 is driven forward by applying a control signal to panel drive unit 43, and front panel 40 is swivelled in first direction D 1 by panel drive mechanism 44. At the following step 110, microcontroller 51 stands by for a specific time period according to the time required from the time when the control signal is output to panel drive unit 43 until the time when the detection signal of first open position P 1 is input. After standing by, microcontroller 51 judges whether or not front panel 40 has arrived at first open position P 1 at step 111.
At step 111, when it is judged that front panel 40 has not arrived at first open position P 1 , it is considered that the driving of front panel 40 has not been appropriately performed and that some kind of error has occurred in panel drive unit 43. Accordingly, in this case, microcontroller 51 proceeds to step 105 in FIG. 9 via link C, and at this step 105 it outputs an error signal, and the error in panel drive unit 43 is displayed on display 54.
On the other hand, at step 111, when it is judged that front panel 40 has arrived at first open position P 1 , it is considered that the driving of front panel 40 has been appropriately performed. Accordingly, microcontroller 51 proceeds to the following step 112 when it is judged in this way at step 111 that front panel 40 has arrived at first open position P 1 , and front panel 40 is held at first open position P1 by stopping panel drive motor 45.
As a result of the control operations of front panel 40 for CD player 20 as described above, when front panel 40 is held at first or second open position P 1 or P 2 (step 112 or step 113), media insertion slot 21 of CD player 20 is in a released state, and it is possible for CD player 20 to perform ejecting and loading. Thereafter at step 114, microcontroller 51 either starts drive motor 23 of CD player 20 or causes it to stand by, and as a result disk eject/loading mechanism 22 of CD player 20 either performs an eject operation or stands by for loading.
At step 104 in FIG. 9, when the instruction signal is not a disk signal relating to CD player 20, and is accordingly judged to be a cassette instruction relating to cassette tape player 30, microcontroller 51 proceeds to step 115 shown in FIG. 11 via link B, and the control operation of front panel 40 for cassette tape player 30 is performed by the operations of steps 115 through 121.
At step 115, microcontroller 51 determines whether or not front panel 40 is in second open position P 2 . At step 115, when it is judged that front panel 40 is in a second open position P 2 , microcontroller 51 holds front panel 40 in the second open position P 2 by stopping panel drive motor 45 of panel drive unit 43. Conversely, at step 115, when it is judged that front panel 40 is not at second open position P 2 , microcontroller 51 proceeds to step 121 and judges whether or not front panel 40 is at first open position P 1 at the following step 116.
At step 116, when it is judged that front panel 40 is not at first open position P 1 , microcontroller 51 proceeds to the following step 117 and judges whether or not front panel 40 is at closed position P 0 . At step 117, when it is judged that front panel 40 is not at closed position P 0 , it is considered that front panel 40 has stopped at a position other than the 3 specific positions P 0 , P 1 and P 2 , and that some kind of error has occurred in panel drive unit 43. Accordingly, in this case, microcontroller 51 proceeds to step 105 in FIG. 9 via link D, an at this step 105, it outputs an error signal and the error in panel drive unit 43 is displayed on display 54.
Conversely, at step 116, when it is judged that front panel 40 is in a first open position P 1 , or alternatively at step 117, when it is determined that front panel 40 is in a closed position P 0 , microcontroller 51 proceeds to the following step 118, reverses panel drive motor 45 by applying a control signal to panel drive unit 43, and swivels front panel 40 in second direction D 2 by panel drive mechanism 44. At the following step 119, microcontroller 51 stands by for a specific period according to the required time from when the control signal is output to panel drive unit 43 to the time when the detection signal of open position P 2 is input. After standing by, microcontroller 51 determines whether or not front panel 40 has arranged at second open position P 2 at step 120.
At step 120, when it is judged that front panel 40 has not arrived at second open position P 2 , it is considered that the driving of front panel 40 has not been appropriately performed, and that some kind of error has occurred in the panel drive unit 43. Accordingly, in this case, microcontroller 51 proceeds to step 105 in FIG. 9 via link D, and at this step 105, it outputs an error signal and the error in panel drive unit 43 is displayed on display 54.
Conversely, at step 120, when it is judged that front panel 40 has arrived at second open position P 2 , it is considered that the driving of front panel 40 has been appropriately performed. Accordingly, when microcontroller 51 has judged at step 120 that front panel 40 has arrived at second open position P 2 , it proceeds to the following step 121 where front panel 40 is held at second open position P 2 by stopping panel drive motor 45.
As a result of the control operations of front panel 40 for cassette tape player 30 as mentioned above, when front panel 40 is held at second open position P 2 (step 121), media insertion slot 21 of CD player 20 and media insertion slot 31 of cassette tape player 30 are both released, and it is possible for cassette tape player 30 to perform ejecting and loading. Thereafter, at step 122, microcontroller 51 controls drive motor 33 of cassette tape player 30, and as a result cassette ejectloading mechanism 32 of cassette tape player 30 either performs an eject operation or stands by for loading.
As shown in FIG. 5 and FIG. 6, when panel drive unit 43 of the present embodiment is in the closed state, slide member 60 is in a neutral position to the front of the center of the operating range from front to back. In this case, operating tabs 72a and 72b provided on rib 60a of slide member 60 are positioned away from actuators 71a and 71b of limit switches 70a and 70b, and the perforated line provided on rib 60b of slide member 60 overlaps with photoswitch 73 at its end. Also, drive pins 63 provided on both sides of front panel 40 in closed position D 0 are in a neutral position to the front of the center of the operating range from front to back, and follower pins 66 are at the top end of guide slots 68.
From this closed state, panel drive unit 43 operates as follows when panel drive motor 45 is driven forward or backward by microcontroller 51 as mentioned above to eject/load disk 2 or cassette 3.
First, when panel drive motor 45 is driven forward by microcontroller 51 from the closed state shown in FIG. 6, slide member 60 is driven by the forward driving force of panel drive motor 45 via gear train 62 and rack 61. In this case, slide member 60 is guided by its guide slots 64 and guide pins 65 on the side of chassis 11, and moves horizontally forward from the neutral position to the front of the center as shown in FIG. 6.
Then, as this slide member 60 moves forward, drive pins 63 of front panel 40, which is supported by the end part of this slide member 60, move horizontally forward from the neutral position to the front of the center, and the bottom part of front panel 40 moves forward. Furthermore, as this front panel 40 moves, follower pins 66 of front panel 40 move down from the top part of guide slots 68, and the top part of front panel 40 moves down. Accordingly, as shown in FIG. 7, front panel 40 swivels in first direction D 1 with liquid crystal TV 41 in its front part pointing up.
Also, as slide member 60 moves forward, photoswitch 73 counts the holes in perforated line 74 by moving relatively to the back end from the front end of perforated line 74 provided on rib 60b of slide member 60; when it has arrived at an arbitrarily set count value, panel drive motor 45 is stopped and a detection signal for first open position P 1 is output and sent to microcontroller 51 of operating/control unit 50. As a result, slide member 60 stops and front panel 40 stops at first open position P 1 shown in FIG. 7. Note that first open position P 1 of front panel 40 is adjustable between closed position P 0 and the limit of the swivel range in first direction D 1 as mentioned above, but when it is set at the limit of the swivel range in first direction D 1 , since actuator 70a of rear limit switch 70a is pressed down by rear operating tab 72a provided on rib 60a on slide member 60 as shown in FIG. 7, panel drive motor 45 is stopped by operating this rear limit switch 70a, and a detection signal for first open position P 1 is output.
Next, when panel drive motor 45 is started in reverse by microcontroller 51 from the closed state shown in FIG. 6, slide member 60 is driven by the reverse driving force of panel drive motor 45, and as shown in FIG. 6, this slide member 60 moves horizontally to the rear from the neutral position to the front of the center.
Then, as this slide member 60 moves to the rear, drive pins 63 move horizontally to the rear from the neutral position to the front of the center, and the bottom part of front panel 40 moves to the rear. Furthermore, as front panel 40 moves in this way, follower pins 66 of front panel 40 move down from the top end of guide slots 68, and the top part of front panel 40 moves down. Accordingly, as shown in FIG. 8, front panel 40 swivels in second direction D 2 with liquid crystal TV 41 on its front part pointing down, and its bottom part is retracted inside chassis 11 of device main unit 10.
Also, as slide member 60 moves to the rear, the front operating tab 72b provided on rib 60a of this slide member 60 also moves to the rear, but when front panel 40 has arrived at second open position P 2 , actuator 71b of front limit switch 70b is pressed down by this front operating tab 72b, and thus panel drive motor 45 is stopped by operating this front limit switch 70b, and a detection signal for second open position P 2 is output.
Furthermore, from the first and second open states shown in FIG. 7 and FIG. 8, the operation to return to the closed state shown in FIG. 6 is performed by turning panel drive motor 45 in the opposite direction to when it was released, and front panel 40 is swivelled in the reverse direction to when it was released. In both of the return operations, front panel 40 arrives at closed position P 0 shown in FIG. 6 as slide member 60 moves, and when the end of perforated line 74 provided on rib 60b of slide member 60 overlaps photoswitch 73, panel drive motor 45 is stopped by operating photoswitch 73, and a detection signal for closed position P 0 is output.
From the above, with the automotive data device according to the present embodiment, front panel 40 is basically swivelled to first open position P 1 with its front part facing up when ejecting or loading disk 2 in the upper CD player 20. Thus, passengers of the vehicle can continue to view and operate liquid crystal TV 41 and user operating switches 42 provided at the front part of this front panel 40 in the same way as in closed position P 0 .
Moreover, in this first open position P 0 , front panel 40 is only swivelled by the minimum amount necessary to release media insertion slot 21 of CD player 20. Thus, compared with the case where media insertions slots 21 and 31 of CD player and cassette tape player 30 are both released, it is possible to greatly reduce the amount of swivel and the amount of projection of front panel 40.
In particular, since media insertion slot 21 of CD player 20 (which is used for relatively thin data recording media) is thinner than media insertion slot 31 of cassette tape player 30, the amount of swivel of front panel 40 can be effectively reduced in the present embodiment where CD player 20 is situated at the top, compared with the case where cassette tape player 30 is.
Then, since it is possible to reduce the amount of swivel and the amount of projection of front panel 40 in this way, it is possible to reduce the time required for ejecting and loading disk 2 in CD player 20. Additionally, it is possible to prevent contact between front panel 40 and disk 2 and to prevent damage resulting therefrom, and it is also possible to increase the installable range of the device.
Also, when ejecting/loading disk 2 from/into upper CD player 20, in the case where front panel 40 is already in second open position P 2 , front panel 40 is held in this second open position P 2 without unnecessary swivelling of front panel 40, and thus it is possible to eject/load disk 2 in CD player 20 immediately and effectively.
On the other hand, when ejecting/loading cassette 3 from to lower cassette tape player 30, front panel 40 is swivelled to second open position P 2 with its front part facing down. Thus, there is no possibility of cassette 3 and the front part of front panel 40 coming into contact, and there is no possibility of damaging liquid crystal TV 41 and operating switches 42 provided on the front part of this front panel 40.
In this second open position P 2 , front panel 40 is in a configuration that projects horizontally forward, but in this case in the present embodiment, the bottom part of front panel 40 is retracted inside device main unit 10 as shown in FIG. 8 and the amount of projection of front panel 40 can thereby be reduced. It is thus possible to prevent damage to front panel 40 and to increase the installable range of the device.
As mentioned above, with the present embodiment, it is possible to view and operate operating switches 42 and liquid crystal TV 41 in the front part of front panel 40 when ejecting/loading disk 2 or cassette 3, and it is possible to prevent damage to front panel 40 and to disk 2 or cassette 3; moreover, it is possible to increase the installable range of the device by decreasing the amount of swivel and the amount of projection of front panel 40. Accordingly, it is possible to increase the convenience of use, ease of operation, and reliability, and it also has excellent flexibility of installation.
Whereas CD player 20 as used in the first embodiment was a CD player 20 capable of directly loading large-diameter disks (12 cm CDs) and small-diameter disks (8 cm CDs) as described above, in a second embodiment microcontroller 51 of operating/control unit 50 is especially set up to control front panel 40 during the ejection of small-sized disks so that it is performed by the operating procedure shown in FIG. 12. To be specific, steps 201 through 209 of this sequence of operations are inserted at the link A portion between step 104 shown in FIG. 9 and step 106 shown in FIG. 10. Note that the other parts are configured in the same way as in the first embodiment.
In the automotive data device according to the second embodiment, microcontroller 51 of operating/control unit 50 basically controls front panel 40 during ejecting/loading according to the procedures shown in FIGS. 9 through 11, and it performs the procedure shown in FIG. 12 only when controlling the front panel for the CD player when ejecting a small-diameter disk.
That is, at step 104 in FIG. 9, when it has determined that an instruction signal relates to CD player 20, microcontroller 51 determines at step 201 in FIG. 12 whether or not the eject/loading instruction signal that was input relates to the ejection of a small-diameter disk. Note that the size of disk 2 is determined in this case based on a detection signal from disk size discrimination sensor 26 as described in the said first embodiment.
Then, at step 201, when it is determined that the input eject loading instruction signal does not relate to the ejection of a small-diameter disk, microcontroller 51 performs the operations of steps 106 through 114 in FIG. 10 as before.
On the other hand, if it is determined at step 201 that the input eject/loading instruction signal relates to the ejection of a small-diameter disk, microcontroller 51 performs the operations of the following steps 202 through 208. Since the sequence of operations in steps 202 through 208 is exactly the same as the sequence of operations in steps 115 through 121 (FIG. 11) to control front panel 40 for the cassette tape player in the first embodiment, their description is omitted.
Next, at step 208 (which corresponds to step 121), as a result of holding front panel 40 in second open position P 2 , media insertion slot 21 of CD player 20 and media insertion slot 31 of cassette tape player 30 are both in a released state, and CD player 20 is in a state where ejecting and loading are possible. Thereafter, at step 209, microcontroller 51 controls drive motor 23 of CD player 20 so as to turn it in the eject direction, and as a result disk eject/loading mechanism 22 of CD player 20 performs an eject operation for a small diameter disk.
With an automotive data device according to the present embodiment having the above-mentioned configuration, the following effects are also achieved in addition to the effects achieved with the said first embodiment. That is, small-diameter disks project by a small amount when ejected as mentioned above, and in particular as shown in FIG. 3 and FIG. 7, media insertion slot 21 of CD player 20 and the top part of front panel 40 are extremely close together when front panel 40 is in first open position Pi; it is thus difficult in this state to remove the small-diameter disk from media insertion slot 21. On the other hand, with the present embodiment, as regards the ejecting and loading of disk 2, since front panel 40 is held in second open position P 2 when a small-diameter disk is ejected, it is easy to remove the small-diameter disk without front panel 40 obstructing the removal of the small-diameter disk. Accordingly, it is possible to further increase the convenience of use and ease of operation, particularly when ejecting small-diameter disks.
The present invention is not limited to the above embodiments, and a broad diversity of other embodiments is also possible. First, the procedure whereby microcontroller 51 operates the front panel 40 in the said embodiments can be appropriately varied. For example, in the above embodiments, the operation was described wherein microcontroller 51 is set up to start control for eject/loading only when front panel 40 is stationary; however, it is not limited to this and it can also be set up to start controlling front panel 40 while front panel 40 is still operating.
For example, when an eject/loading instruction is input while front panel 40 is still moving, the swivel direction of front panel 40 is determined, and if this swivel direction is appropriate, it continues to drive front panel 40; conversely, if the swivel direction is inappropriate it can be set up to reverse the swivel direction of front panel 40 by reversing panel drive motor 45. When set up in this way, front panel 40 can be controlled faster and more flexibly.
Furthermore, the above embodiments are configured so that control is performed for the eject/loading of CD player 20 and cassette tape player 30 after the control of front panel 40 is completed, but these forms of control may also be performed at the same time. Also, the operating unit and control unit may be freely configured; for example, the above embodiments may be varied by incorporating a control means comprising microcontroller 51 and operating/control unit 50 inside device main unit 10. In this case, display 54 may be substituted by the display screen of liquid crystal TV 41.
On the other hand, the specific configuration of panel drive unit 43 for driving front panel 40 can be freely varied. For example, in the above embodiments it was configured to move slide member 60 horizontally and swivel front panel 40 by means of V shaped guide slots 68 provided on device main unit 10 via drive pins 63 and follower pins 66; however, various mechanisms can be appropriately applied wherein the horizontal driving force of slide member 60 is similarly converted into a swivel drive force so as to swivel front panel 40 in the two directions.
Also, in the above embodiments, the open positions of front panel 40 are only set to one place in each of the first and second directions; however, it is also possible to set a plurality of open positions in each of the swivel directions or to allow it to be set in a continuous range of positions during manual operation. For example, in the above embodiments a configuration is envisaged wherein front panel 40 can also be made to stop at a position where only the media insertion slot 21 of CD player 20 is released by swivelling in the second direction.
Note that in the above embodiments, cassette tape player 30 is situated at an inclined angle, but it may also be situated horizontally. Also, a configuration wherein cassette tape player is situated at the top and CD player 20 is at the bottom is also possible. Furthermore, the present invention is not limited to the combination of a CD player and a cassette tape player and may be freely assembled from any combination of various disk players such as MD players, IC card reading devices, or various recording and playback devices including DAT players, video tape players and so on, which may be situated at the top or at the bottom. It is also possible to provide various devices besides the liquid crystal TV in the front part of front panel 40.
The present invention may also be configured with a vertical arrangement of n (3 or more) recording and playback devices, in which case it is envisaged that n open positions are set up to respectively release the media insertion slots up to the nth recording and playback device from the top. For example, a configuration is envisaged whereby it swivels in a first direction when releasing only the media insertion slot of the uppermost recording and playback device, and swivels in a second direction when releasing the media insertion slots of the second and subsequent recording and playback devices from the top. It can also be configured so as to release the media insertion slots of a plurality of recording and playback devices by swivelling in the first direction.
As described above, the present invention is configured so that front panel 2 is swivelled in two directions and each of the media insertion slots is released by swivelling in these directions, and is also configured so that this swivelling of the front panel is controlled according to attachment/release instructions to the recording and playback devices; compared with the prior art, it thereby enables the front part of the front panel to be viewed and operated when data recording media are ejected inserted, and can prevent damage to the front panel and to the data recording media; moreover, it can increase the installable range of the device by decreasing the amount of swivel and the amount of projection of the front panel. Accordingly, it is possible to provide an automotive data device with superior convenience of use, ease of operation, reliability, and flexibility of installation.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
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An automotive data device, such as an audio player, for playing recording media of a different size includes a housing member housing a first player unit and a second player unit in a stacked arrangement. Each of the player units have insertion slots. A movable operating panel for controlling the respective first player unit and the second player unit extends across the respective insertion slots. A control unit can drive the movable operating panel in a first mode of operation to expose only the first insertion slot, while maintaining the operability of user controls on the operating panel. The control unit provides a second mode of operation to expose both of the insertion slots, while retracting at least a portion of the operating panel into the housing member below the lower insertion slot.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This novel invention relates to a drain and gutter assembly, and more particularly to a novel shield for a drain and gutter assembly additionally constituted to provide a substantially vertical flange which acts as a dam to prevent the flow of excess rainwater and the like over an edge of the gutter.
2. Description of the Prior Art
The following issued patents comprise a portion of the developed pertinent prior art related to this invention, to wit: U.S. Pat. No. 1,308,311 issued to Ward on July 1, 1919; U.S. Pat. No. 2,175,138 issued to Westlake on Oct. 3, 1939; U.S. Pat. No. 2,284,440 issued to Morrissey on May 26, 1942; U.S. Pat. No. 2,805,635 issued to Couture for a gutter screen fastener on Sept. 10, 1957; U.S. Pat. No. 4,032,456 issued to Berce for a flip up gutter shield on June 28, 1977; U.S. Pat. No. 4,351,134 issued to Clarkson for a hinged gutter guard on Sept. 28, 1982; U.S. Pat. No. 4,395,852 issued to Tang for a gutter guard on Aug. 2, 1983; U.S. Pat. No. 4,418,508 issued to Lassiter for a drain shield for gutters on Dec. 6, 1983; and, U.S. Pat. No. 4,455,791 issued to Elko, et al. for a protective cover for gutters on June 26, 1984.
None of the above cited patent references disclose a construction of a drain and gutter shield with a means for damming water from overflowing over the edge of said gutter or which is similar to or anticipatory of the novel construction and assembly of the invention described herein.
In 1919, Ward patented a new and useful improvement to an eaves trough protector which provided a simple, strong and effective device for protecting eaves troughs from becoming clogged with leaves or other light debris by preventing such objectionable matter from entering the eaves trough without preventing free admission of the drainage water from the roof. An essential aspect of this invention was to provide a device, readily removable if desired, to present ready access to the trough to clean out any dirt or other finely divided material which may pass through the protector. Westlake, in his 1939 patent, made a significant improvement by providing a stranded eaves protector wherein the strands were diagonally disposed with respect to the longitude of the eaves trough.
In U.S. Pat. No. 2,284,440 Morrissey provided an eave trough protector which was of light weight and which could be formed in and was capable of being applied in one continuous piece throughout the length of the eaves trough or gutter and thereby eliminate overlaps, seams, and splicing which has been employed prior to that time in screen type protectors.
Couture, in his gutter screen fastener patented in 1957, provided a mounting clip adapted for positioning upon relatively short lengths of the gutter screen and thereby provided means for securing a screen to a gutter flange. On the other hand, Burce, in 1977, provided the first flip up gutter shield capable of being flipped and moved to a position away from the gutter for servicing of the gutter. The Berce patent provided a flip up gutter shield which, when in the flipped up position, was completely out of the way of the person servicing the gutter. It facilitated ease of painting.
Clarkson provided an improvement over the flip up gutter shield of Berce. Clarkson provided a hinge gutter guard in the form of an elongated perforated cover plate made of relatively rigid sheet material and equipped along one longitudinal edge with a plurality of hinge straps adapted to be secured to a roof beneath the lower course of shingles thereof.
Tang, on the other hand, provided a gutter guard for an open top gutter mounted on the eaves of a building of the type having a roof covering with a peripheral edge of the roof covering adjacent to the gutter arranged so that it could be lifted slightly to receive a portion of the gutter guard. A key difference of Tang, over the prior art, is that a plastic sheet is divided longitudinally into portions, each portion adapted to be alternatively positioned under the peripheral edge of the roof covering with the other portion positioned over the gutter. The outer longitudinal edges of this sheet are formed with a narrow bendable flaps defined by fold lines and the portions of this sheet are separated by another fold line. A clip fits over the top rim of the gutter and receives the edge of the guard and its flap to hold the guard in position on the gutter.
Lassiter's drain shield for gutters is concerned with a drain shield to prevent leaves, pine needles and the like from entering the gutters and causing them to clog and required periodic cleaning and maintenance. The unique feature of the Lassiter patent is that his drain shield allows rainwater to easily enter the gutters while causing leaves, twigs and other debris to be washed over the edge of the gutter to be ground below. Also unique to Lassiter is the way in which the perforations are formed in the gutter shield.
Elko also provides a protective cover for gutters which includes an elongated and pervious sheet, wide enough to extend across at least 90% of the width of the gutter and up under a lower edge of the roofing material. However, the outer edge of the Elko cover curls downwardly and the water flow follows the curvature by surface tension to cascade into the gutter. The problem with the Elko protective gutter, which is solved by the present novel invention, is that the volume of water increases to a predeterminable level as it flows over the gutter sheld. The volume of water becomes so great such that the surface tension is insufficient to cause all of the water to flow into the gutter. Similarly, in Lassiter and Clarkson with a predetermined level of water flow over the gutter shield, the volume becomes so great so as to cause water to flow over the edge of the gutter shield and thereby substantially diminish the function of the gutter and downspout for directing precipitation off of the roof of the dwelling.
The overflowing of water over the peripheral edge of the gutter shield of both Lassiter and Clarkson is alleviated by the novel means of the present invention which retains this excess flow of water and causes same to accumulate and then flow through the perforations made available in the gutter guard and by directing the water flow along the drain shield or gutter guard.
OBJECTS OF THE INVENTION
Roof gutters are constantly in need of cleaning as a result of leaves, pine needles, twigs and other debris which are washed from the roof during rain storms. Homeowners are particularly plagued during the fall season as leaves fall from nearby trees to fill the gutters and block downspouts, causing the gutters to overflow. To alleviate this problem, prior art devices have been developed which include screens and other apparatus to stop leaves from entering the gutter and straining devices which prevent the leaves once they have entered the gutter to pass into and down the downspout.
With this background in mind, the present invention was developed and one of its objectives is to provide a gutter shield with a rain dam wherein excessive water from heavy rains is contained by the gutter shield and either allowed to drain in delayed fashion or directed towards the end of the gutter to the downspout.
Accordingly, it is the object of the present invention to provide a gutter shield which does not allow leaves and debris to pass over the edge of the gutter and which further does not allow rainwater to pass uninterrupted over the edge of the gutter but, instead, directs rainwater during heavy downpours towards an end of the gutter covered by a gutter shield to facilitate its direct passage through the downspout of the gutter to the ground.
SUMMARY OF THE INVENTION
The invention, as disclosed herein, is a gutter shield for positioning on a drain gutter of a house or other building. The shield consists of a planar member which may be made of galvanized sheet metal, plastic, aluminum, copper, or other suitable materials. The planar member has a dispersed series of perforations or apertures and along its edge a series of slots. At the edge thereof, the planar member has a vertical wall member for directing the flow of rainwater along the gutter shield to each end thereof during heavy rain downpourings. A heavy flow of rainwater enters the apertures as well as flows down the gutter to the downspout without undue interference from solid materials, leaves, etc. The vertical wall member at the distal edge of the shield provides a trough means whereby liquid is guided in heavy downpours toward the ends of the gutter to the vicinity of the downpipe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 demonstrates the preferred embodiment of the drain shield positioned on a drain gutter;
FIG. 2 illustrates a side elevational view of the drain shield shown in FIG. 1;
FIG. 3 illustrates a top plan view of the drain shield shown in FIG. 1;
FIG. 4 illustrates a cross-sectional view of the drain shield shown in FIG. 3, taken along the line 4--4.
FIG. 5 illustrates a close-up sectional view of the drain shield shown in FIG. 2 and enclosed in the circle 5; and,
FIG. 6 is an enlarged view of a clip adapted to attach the drain shield to a gutter.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, like reference characters designate similar parts in the several views of the invention shown in the drawings.
Referring now to FIG. 1 of the drawings, there is shown a section of a shield 10 of the preferred embodiment of the drain shield of the present invention which may be formed, for example from metals, plastics, or other suitable materials. As many sections as desired may be placed along the gutter 14 to insure full protection of the gutter 14 substantially along its entire length. However, a cavity 16 is formed inside the gutter 14 sufficient to contain the flow of water.
Shown in FIG. 1 is an end member 18 attached to the drain shield 10 and the gutter 14. The cavity 16 is a hollow space adapted to receive run off from the shield 10. Rainwater flowing along the surface of the shield 10 is directed towards a down pipe 26 by the patch of the gutter 14 in conjunction with a wall 20 substantially vertically oriented.
A roof 22 is shown attached to a house 24. Attached to the house 24 and roof 22 is the gutter 14. Shown attached to the gutter 14 is the down pipe 26. The down pipe 26 has an upper aperture 28 through which rainwater, draining from the shield 10, flows to the ground (not shown).
The shield 10 has a plurality of perforations 30 disposed about the shield 10, either randomly or in a specific pattern such as that shown, for example.
The drain shield 10 may also be adapted to be inserted underneath the lower most shingles, for example shingles 32 and 34 covering the edge of the roof 22 of the house 24 inbetween the shingles 32 and 34 and an eave 36.
In a substantial downpouring of rain, such that a torrent of water flows over the shingles 32 and 34, for example, water is directed onto the shield 10. A portion of this water passes through the perforations 30 into the gutter 14.
Another portion of this water flows over the surface of the shield 10 and is blocked from flowing over the edge of the gutter 14 by the wall 20. The wall 20 in turn directs some of this water along the shield 10 until it falls through to the cavity 16 and then to the down pipe 26 by means of the pitch of the gutter 14 whereby it flows into the gutter 14 and subsequently down through the down pipe 26 via the aperture 28 for example.
FIG. 2 is a partial cross-section of the gutter 14, drain pipe 26, and shield 10 assembled and attached under the eave 36 to the house 24. There is shown means for attachment of the shield 10 to the gutter 14. This means comprises for example, a specially adapted clamping pin 38. The clamping pin 38 is adapted to be inserted partially through one of a series of slots, for example slot 56 (shown in FIGS. 4 and 5), in the shield 10 and then snapped in to secure the shield 10 to a lip 40 of the gutter 14. A bulge 39 in the pin 38 is more clearly shown in FIGS. 5 and 6 and provides the snapping action for the pin 38 and slot 56 assembly.
FIG. 2 further shows a side view of the eave 36 of a building, for example the house 24. This structure includes a fascia or cornice 42 attached at an end of a rafter such as, for example the rafter 44. The gutter 14 is nailed to the end of the rafter 44 by a nail 46, for example. The rafter 44 supports the sheathing 48, a main structural member of the roof assembly 50.
The pitch of the roof may be as flat as 1 in 12 or even less, or as steep as 8 in 12, or even more, for example. Such sheathing 48 is typically made of about 0.9 centimeter or 1.2 centimeter plywood in current buildings. According to standard practice, the sheathing 48 is covered with a layer of roofing felt 52, typically of #15 weight. Layers of shingles 32 and 34 are nailed down. The underside of the eave 36 is covered by a plywood soffit (not shown). The gutter structure includes a gutter 14 having a front wall 51, a bottom wall 53, a rear wall 55, and end walls, for example, end wall 57.
Modern gutters of the type shown in FIG. 2 are referred to as O.G. gutters and are normally formed of galvanized sheet metal, aluminum or plastic. The upper end of the front wall 51 has a vertical portion 61 and an inwardly turned lip 40 that has an inner most edge 41. This lip 40 is at substantially the same level as the upper edge of the end wall 57. The drain pipe 26 leads water out of the gutter 14 and typically carries it to a drain or dry well (not shown) or simply out into the yard some distance from the house 24.
The gutter 14 is nailed to the house 24 by means of a series of spikes or nails 46 that extend through holes (not shown) in the rear wall 55. To provide proper spacing, which is typically 5 or 6 inches, between the rear wall 55 and the rafter 44, the nails 46 are sometimes enclosed in tubular metal ferrules (not shown).
Normally the lower most edges of the lowest level of shingles, for example shingle 34, extend out over the lower most edge of the roofing felt 52 so that water falling on the shingles runs directly into the gutter 14. While the water should run down the gutter 14 to downpipe 26, it has been found that it frequently carries twigs and leaves and other debris into the gutter 14 and either clogs up the downpipe 26 or builds up and dams the gutter to prevent the proper run off of water. In that case, water tends to flow over the lip 40 of the gutter 14 or even to back up into the building itself under the roofing felt 52.
To keep the gutter 14 and shield 10 from accumulating debris, the present invention combines the shield 10 and the wall 20 for damming water. Shown separately in FIG. 3, the wall 20 is in the form of an elongated shield that extends longitudinally along the gutter 14.
The edge which is bent to form the vertical wall 20 is located near the inwardly turned edge of the lip 40 (FIG. 2). The shield 10 is wider than the space between the lip 40 and the rear wall 55 of the gutter. The shield 10 is typically within a range of 14 centimeters to 20 centimeters wide and is preferably about 16.5 centimeters wide. It may be made of metal, such as aluminum or #26 gage galvanized iron, or it may be made of plastic. In the embodiment shown, the lip 40 has a width for its upper surface of about 1.2 centimeters and extends approximately 270 degrees around from the point at which it begins at the outer edge of the flat part of the shield 10.
FIG. 3 is a plan view of a portion of the shield 10 initially described above. The shield 10 has a plurality of holes therein for the drainage of rainwater therethrough such as, for example the pattern of apertures 30. There is also shown, as part of the shield 10, a plurality of slots 54 and 56 and others not shown. Near the slots 54 and 56, there is shown a vertical flange, for example the wall 20. The vertical flange operates as a rain dam and prevents the flow or inhibits the flow of rain water over the edge 62 of the shield 10.
There is shown in FIG. 4 a side view of the shield 10 taken along the line 4--4 as shown in FIG. 3. The apertures 30 are shown along with a cross-section of the slot 56.
Shown in FIG. 5 is a partial cross-section of an assembly of the shield 10, gutter 14 and clip member such as pin 38, for example. There is the wall 20 in cross-sectional view shown as an integral part of the shield 10. The apertures 30 are sized to prevent debris such as the leaf 67, for example, from flowing into the gutter 14. The size of each aperture 30, by area, is approximately one half square centimeter, for example.
Shown in FIG. 6 is a detailed side view of the pin 38. The pin 38 has a shaft 60, which bulges into the bulge 39, and a head 62. The head 62 somewhat resembles a nail head and is sized such that it is round in shape and has a diameter substantially greater than the width of each slot, for example slots 54 and 56 shown in FIG. 3, each of which is adapted to receive this clamping pin 38. The shaft 60 of the clamping pin 38 has a length L equal to approximately 1 or 2 centimeters with a 90 degree bend at approximately halfway from the head 62. The shaft 60 also has another bend approximately at the tip thereof. The pin 38, shown in FIG. 6, is adapted to snap through and fit snugly around the innermost edge 41 and lip 40 in the fashion as specifically shown in FIG. 5 such that the pin 38 functions as a means for clamping the drain shield 10 to the gutter 14.
Other features, advantages and objects of the invention will become apparent from the specification as read specifically in conjunction with the drawings which depict the preferred embodiment of the invention.
While the foregoing preferred embodiment of the invention has been set forth in considerable detail for purposes of illustration, it is to be understood by those skilled in the art, that many of these details may be varied without departing from the scope of this invention and, the inventor hereof hereby invokes the doctrine of equivalents insofar as applicable.
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A drain shield for gutters or the like with one part adapted to prevent leaves, pine needles and other debris from entering the gutters and causing them to clog and require periodic cleaning and maintenance and another part adapted to dam rainwater and other precipitation, re-direct the flow of the precipitation and inhibit water from flowing over the edge of the gutter.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 USC 119 (e) (1) from U.S. Provisional Patent Application Ser. No. 61/5/3,263 filed Sep. 2, 2011 of common inventorship, herewith entitled “Pest Pistol.”
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0003] Not Applicable
FIELD OF THE INVENTION
[0004] The present application is a regular utility application for patent The present invention pertains to the field of pest control, and more specifically, to the field of handheld pest control sprayers for outside use.
BACKGROUND OF THE INVENTION
[0005] The prior art has put forth several designs for pest control devices. Among these are:
[0006] U.S. Pat. No. 6,003,787 to Jerry W. Fisher describes an insecticide spray assembly for spraying insecticide in confined areas. The spray assembly composes a spray gun, a compressor, a nozzle, a trigger, a receiver on the spray gun for attaching pesticide containers, and a plurality of bottle holders on the base for carrying spare pesticide containers.
[0007] U.S. Pat. No. 5,806,230 to Richard J, Brenner, David E. Milne and Stoy A. Hedges describes a vacuum device having a hand held intake and collection unit, combined with a handheld healer and air exhaust tube assembly. This device functions to chase and collect posts such as insects along with their associated allergens. The device contains filter assemblies which remove contaminants and exhausts clean air back into the surrounding environment.
[0008] U.S. Pat. No. 4,197,872 to Thomas A. Parker describes a high pressure dispensing system for liquids comprising a device wherein an accurate amount of a chemical concentrate is injected and mixed into a pressurized carrier liquid stream and dispensed by employment of two calibrated hi-line valves in the line siphoning the concentrate to a siphon injector.
[0009] None of these prior art references describe the present invention.
SUMMARY OF THE INVENTION
[0010] The pest pistol is a bug control device suited tor outdoor use. It can be used to hit an insect or insect's nest up to forty feet away. The device, known as the pest pistol, is a hand-held device for hitting bugs or other pests from a distance with an insecticide or other type of deterrent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a partial out away view of a first embodiment of the pest pistol.
[0012] FIG. 2 is a partial cut away view of a second embodiment of the pest pistol.
[0013] FIG. 3 is a diagrammatical side view of the pistol of the present invention showing the ammunition dip housing pressurized carbon dioxide with or without insecticide.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention, hereinafter referred to as the Texas Pest Pistol, or Pest Pistol, as shown in FIG. 1 , is a handheld gun shaped pest control device specially designed for outdoor use that allows users to shoot insecticide at flying insects, other pest and/or their nests. The Pest Pistol is designed primarily for optimal range in reaching flying pests, pests in trees, as well as attacking bee and wasp nests that are out of normal reach, from five to forty feet. The present invention resembles a paintball gun or a long barreled hand gun with a reach of up to forty feet. It will use a pressurized carbon dioxide [ 1 ] to shoot insecticide capsules [ 2 ] at the targeted insect, insect's nest, or other pest from a spring loaded tube [ 3 ]. A dial [ 4 ] will be used to set pressure that will foe released to launch the insecticide capsules the desired distance. Manufactured with a durable plastic material the Pest Pistol comprises a barrel [ 5 ], trigger [ 6 ] and stock [ 7 ]. The trigger features an adjustable spring to reduce or increase the pressure using the aforementioned dial [ 4 ] with which the Pest Pistol is shot, thus increasing or reducing the distance of the strike or firing range.
[0015] As shown in FIGS. 2 and 3 the pest pistol comprises, the handle [ 8 ] of the stock, which contains an ingress port [ 9 ] for accepting a cartridge of pressurized carbon dioxide [ 10 ], an ammunition clip [ 11 ] which may be loaded with carbon dioxide propelled capsules, which capsules may be pre-filled with a chosen insecticide or deterrent chemical. The user simply loads the ammunition clip, sets the pressure dial [ 12 ] for the desired distance, points, aims, and shoots at the designated target. Such targets may include, but are not limited to insects, or insect nests that hug the corners of eaves, bug havens ensconced in trees, or any other area containing pests that is out of range of conventional sprays or cannot be conveniently reached without use of a ladder or other climbing instrument.
[0016] Further still referring to FIG. 2 , an alternative embodiment will include a batten/ powered laser light [ 13 ] utilized to target nests and larger insects. A further alternative embodiment will include a laser scope [ 14 ].
[0017] Further, a hook and string, not shown, can be incorporated into the liquid ammunition or shot along with the ammo when shooting into a nest or hive Once the occupants have been exterminated, the user could pull on the string and hook and pull the nest or hive from the tree without difficulty or direct contact.
[0018] The Pest Pistol provides consumers with a simple and effective means of repelling and killing flying insects when they wish to enjoy the outdoors. Able to reach these pests at their source, this creative product facilitates efficient insect control, easily reaching high placed nests and other hiding places not conveniently accessed. The user can eradicate wasps, bees and spiders before the insects begin swarming around outdoor revelers. The Pest Pistol proves a handy assistance in keeping tree dwellers such as beetles and worms from falling on to people or food. The projection of the Pistols pesticide Reaches heights of approximately 40 feet. In this manner, use of ladders and dangerous situations involving spraying and fleeing Will be effectively avoided. The versatile Pest Pistol can attack most pest control problems. Made of durable, high quality materials, the Pest Pistol will withstand years of continued use.
[0019] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.
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A pest deterrent device comprising a barrel trigger and stock, utilizing pressurized carbon dioxide to launch a capsule which may contain a pest deterrent or insecticide at remote pests such as insects or their nests at distances of five to forty feet.
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This is a of copending application Ser. No. 07/628,699 filed on Dec. 14, 1990, now abandoned.
TECHNICAL FIELD
The invention relates to an apparatus for dewatering slag sand, in particular blast furnace slag sand located in a receptacle.
BACKGROUND OF THE INVENTION
In the prior art, the slag flowing out of a shaft furnace, e.g. a blast furnace, is quenched by means of water jets emerging from nozzles in such a way that the liquid slag turns into a more or less fine slag sand. So that this slag sand can be used further in a profitable manner, the mixture of slag sand and water known as the slag mash, which results from the said spraying must as far as possible be dewatered.
According to the prior art, this dewatering takes place without exception by wall sections of a receptacle for the wet slag sand being designed as filtering surfaces permeable to water. To this end, the vertical side walls, for example of a cylindrical receptacle, can be designed entirely or partly as filter surfaces, or even only the conical outlet area of such a receptacle.
In the first case, the filtering surfaces can be designed to be relatively large, but the portion of slag sand located in the bottom, e.g. conical, outlet is left without being dewatered; whereas in the second case, dewatering of this portion certainly takes place, but the filtering surface remains relatively small. In both cases, but especially in the last mentioned case, the filter surfaces are exposed to high mechanical compressive stress from the contents of the receptacle so that these filter wall sections must be of appropriately resistant, that is expensive, construction.
A particularly serious disadvantage of both constructions (or a combination of the two) consists in the fact that the said filter surfaces become clogged by slag sludge after relatively short use and thus become ineffective. To remove the sludge from the filter surfaces, injection of water, for example by means of nozzles, from outside through the filter surfaces toward the interior of the receptacle is known in the prior art.
SUMMARY OF THE PRESENT INVENTION
To avoid these disadvantages of the prior art, it is therefore the object of the invention to propose an apparatus of the generic category mentioned at the beginning for dewatering slag sand, which apparatus does not need any filter surfaces while maintaining a maximum dewatering effect.
This object is achieved by an apparatus which is characterized in that the bottom outlet opening of the receptacle leads into an outlet funnel which is arranged downstream of the receptacle and whose diameter in the area of the said bottom outlet opening is greater than the diameter of this outlet opening of the receptacle that a free, annular passage for rising extracted water flowing off over the said top edge is formed between the said outlet opening and the said top edge.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are shown in the drawings and will be described in greater detail below.
In the drawings:
FIG. 1 shows a schematic longitudinal section through a first exemplary embodiment of the invention having an essentially conical outlet funnel.
FIG. 2 shows a schematic longitudinal section through a second exemplary embodiment of the invention similar to that in FIG. 1 but having a double outlet funnel in tandem arrangement.
FIG. 3 shows a schematic longitudinal section through a third exemplary embodiment similar to that in FIG. 1 but additionally having a pivotable shutter for the receptacle outlet.
FIG. 4 shows a schematic longitudinal section through a fourth exemplary embodiment of the invention having a cylindrical-conical profile of of the outlet funnel.
FIG. 5 shows a schematic longitudinal section through a fifth exemplary embodiment of the invention similar to that in FIG. 4 but having a conical widening of the receptacle outlet.
FIG. 6 shows a schematic longitudinal section through a sixth exemplary embodiment of the invention, essentially consisting of a combination of the exemplary embodiments according to FIGS. 1 and 5.
FIG. 7 shows a schematic longitudinal section through a sixth exemplary embodiment of the invention having a vertically adjustable outlet funnel.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the bottom part of a, for example cylindrical, receptacle 8 for the slag sand to be dewatered, having a preferably conical bottom outlet 10 (the slag sand charge of the receptacle 8 is not shown further in the FIGURE). The outlet opening 12 of the outlet 10 is surrounded by an outlet funnel 14 arranged downstream, likewise of an essentially conical shape. The diameters of the outlet 10 in its bottom part and of the outlet funnel 14 are appropriately selected in order to create between the two a conical annular gap 16, the top edge 18 of the outlet funnel 14 being higher than the bottom edge of the outlet opening 12.
The functional principle of the apparatus according to the invention is based on the principle of communicating vessels. On the basis of this principle, the water contained in the slag sand rises in the annular channel 16 and runs off in a first stage of the dewatering over the top edge 18 of the outlet funnel 14. On account of its density and internal friction, the slag sand portion of the slag mash does not participate in this rising of the water in the annular space 16, which results in the separation between sand and water, and with astonishing efficiency, as tests have shown. Accordingly, the slag sand itself acts as a filter mass.
In said first stage of the dewatering, the water is allowed to flow of over the top edge 18, since a good separating action between water and any entrained sludgy sand constituents takes place over the relatively large distance thereby provided between outlet 12 and this top edge 18, in particular because substantial slowing-down of the water velocity takes place when the water rises in the widening annular gap 16.
The water flowing over the edge 18 is caught in an encircling annular space 20 and drawn off via a discharge 21.
For the purpose of further providing the separating effect between water and entrained slag sludge, a separating and steadying wall 22 having an additional separator action can facultatively be provided in the annular space 20, in which case accumulating sludge can settle in the bottom part of the annular space 20 and, after dewatering is complete, can be drawn off through a discharge 28.
It has been found in said tests that, in the further course of dewatering, the cleanliness of the accumulating water increases on account of the increasing filtering effect of the slag sand drying in the receptacle 8, and the accumulating water quantities naturally decrease. The invention therefore facultatively makes provision for the water, as water purity increases and water quantity decreases, to be allowed to flow off, first of all through a valve 24 and later through a valve 26 in an even lower position, as a result of which the dewatering process is shortened. During the dewatering operation, the flow of slag sand is blocked by the cylindrical run-off connection piece 30, e.g. by means of a squeezing valve (not shown) which is known per se and is attached below the connection piece 30 in the adjoining discharge pipe (not shown).
Finally, the invention facultatively provides water injection nozzles 32 in any number which are arranged all around at the top part of the annular space 20 and serve to clean the outlet funnel 14 if the receptacle 8 is completely emptied at any time between two dewatering operations.
FIG. 2 shows an embodiment variant of the invention in which two outlet funnels 34, 36 connected one behind the other in tandem arrangement are provided. In this way, not only is the intended separating effect according to the invention between slag sand and water improved even further, but the portions of slag sand otherwise not participating in the separation operation, e.g. in FIG. 1, the quantities of slag sand located below the outlet opening 12, are also reduced to a minimum. The bottom funnel 36 is used for this purpose by opening its water outlet 37 when the top funnel 34 has performed its function.
FIG. 3 shows a constructional example having a pivotal shutter 38 at the outlet 40 of the receptacle 8. The squeezing valve (not shown) is relieved of the weight of the receptacle charge by this shutter 38. But the shutter also helps to reduce to a minimum the bottom quantity of slag sand already reduced with the arrangement according to FIG. 2 and not dewatered.
FIG. 4 shows a construction in which an outlet funnel 42 according to the invention is not designed so as to run continuously in a conical manner to the top, e.g. in FIG. 1, but its top part 44 has essentially cylindrical forms. To make this possible, the outlet of the receptacle 8 has a corresponding cylindrical connection piece 46. This configuration ensures that small quantities of slag sand cannot possibly be floated off to the top along a continuously sloping funnel wall (see 14 in FIG. 1) but are retained in the bottom part of the funnel 42 on account of their density.
In FIG. 5, in an extended construction of FIG. 4, an outlet connection piece 48 of the receptacle 8 is provided at the bottom with a conical skirt 50 widening toward the bottom. This configuration creates a relatively narrow annular gap 54 between the skirt 50 and the outlet funnel 52, with the effect that not only is slag sand restrained in a purely mechanical manner from floating up, but in addition a further separation effect also results due to the water-velocity gradient in the gap 54 and the annular space 56 located above it.
The construction according to FIG. 6 puts into concrete form an extension of the idea of the separation effect by means of water-velocity gradient in the annular gap 58, widening to the top, between the outlet skirt 62 of the receptacle 8 and the funnel wall 66, which is again of conical design. Due to the considerable cross sectional increase in this annular gap 58 and the deceleration in the water velocity accompanying this reduction, the said separation effect is substantially assisted by decantation.
FIG. 7 shows an extension of the inventive alternative shown in FIG. 6 by the outlet funnel 68 according to the invention being designed to be vertically adjustable with accessories. Encircling bellows 70 permit a corresponding vertical moment of the sytem, this vertical displacement being brought about with the aid of means (not shown) known per se.
If the funnel 68 is displaced upwards, the gap 72 narrows while at the same time the water volume located above it increases and the end edge 74 is lifted higher, which as follows from the above explanations, results in optimum cleaning effects. This vertical adjustment enables the apparatus to be optimally adapted to various grades of sand.
For the purpose of further optimizing the cleaning effect, the invention facultatively provides an annular encircling filter element 78 between the outlet connection piece 76 of the receptacle 8 and the outlet funnel 68. In contrast to the filter elements mentioned at the beginning according to the prior art, this filter element 78, which preferably acts as a retaining screen, is not exposed to any great mechanical stress together with corresponding wear and in particular does not have to bear the weight of the receptacle contents.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitations.
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Provided below the funnel-shaped outlet opening of a receptacle filled with wet slag sand is an outlet funnel which is closed to begin with and forms a conical annular gap around the receptacle. This gap fills with slag sand, as a result of which dewatering occurs according to the principle of the siphon effect.
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This is a continuation of copending application Ser. No. 07/221,639 filed on July 20, 1988, abandoned.
BACKGROUND OF THE INVENTION
Severely disabled persons, particularly those confined to wheelchairs are prone to develop posture problems and deformities. If not corrected, improper or inadequate positioning can further exacerbate posture deformities. It has been estimated that 90% of persons who have been confined to wheelchairs, for two years or more, develop one or more posture deformities.
When a person's disability requires confinement to a wheelchair, various posture problems can result as a consequence of improper seating or positioning in the chair. For example, leaning to one side in a wheelchair can cause a condition known as pelvic obliquity, which results in one hip being lower than the other. If left uncorrected, pelvic obliquity often causes the person to develop scoliosis, an abnormal and severe curvature of the spine, and pressure sores. Slouching can lead to kyphosis, an abnormal backward curvature of the spine. Consequences of kyphosis include increased pressure on the coccyx and if carried to the extreme, a tendency to slip off the seat and possibly out of the chair. Further positioning or posture problems include abduction or adduction of the legs (the legs are either too far apart or too close together) and windswept hips (one hip is forward and the legs are swept to the opposite side), which can also lead to physical deformities. In children, these problems are particularly devastating because the deformity can become permanent within months if not corrected.
The prior art has attempted to alleviate positioning and posture problems with custom-designed wheelchairs which adjust to allow proper positioning of the legs, hips, torso, etc. and which are custom designed and built to alleviate the particular posturing difficulties of a specific patient. The advantage of this system is that it is immediately adjustable to the positioning needs of a specific patient and allows for body growth and other changes in the physical condition. However, this system is extremely cumbersome and expensive. Further, an individual's disability is accentuated by the increased equipment surrounding him. Finally, the increased equipment makes physical contact, such as hugging, difficult.
The prior art has attempted to alleviate the problems encountered with such custom-designed wheelchairs with custom molded seat cushions, such as the Pin Dot custom foam system. Custom molded cushions are designed and molded to meet the specific posturing needs of a particular patient. These attempts are successful to a limited extent. However, custom molding is a time consuming and expensive procedure and does not allow for on the spot correction of seating or posturing problems and is not flexible to a person's physical changing needs. Finally, in the case of a disabled child, a custom molded cushion does not allow for growth and in a few months time is obsolete for the particular physical needs of that child.
Problems with seat stability are also particularly critical with respect to wheelchair users. A cushion which provides for correct posture and thus stable seating enhances the users ability to wheel and turn the chair by grasping the wheels, to get in and out of the chair, to reach the floor to pick up an object and other types of movements. A cushion which lacks stability creates a fear of falling from the chair which will inhibit the user's range of movement. However, a seat cushion which provides a stable and comfortable seat and which assists in proving correct posture, will improve the user's equilibrium and sense of orientation.
The custom-designed cushions of the present invention overcome the foregoing problems as is more fully described below.
SUMMARY OF THE INVENTION
The present invention relates to customizable seat cushions and more particularly to a contoured or shaped tray or base whose effective contours can be selectively augmented by addition of removably securable anatomically shaped supports and covered with a pressure relieving pad containing a fluid filling material to present a customized, comfortable posture correcting, pressure relieving seat cushion specific to the particular and changing physical needs of an individual.
In the preferred embodiment, the shaped tray has upwardly extending rims on both sides and a modified rim at the front (with areas to accommodate the legs of the user of the cushion), but the tray is preferably open in the rear to avoid placing any pressure on the ischial tuberosities (seat bones) or the coccyx (tail bone), or the back during reclining. The opening in the rear should be at least six inches wide, and may extend across the entire width of the traY. Preferably the front rim is deep enough (as measured from front to back) to provide support for the user's legs and includes two areas of somewhat reduced elevation to accommodate the user's legs. The rims of the tray function to generate supporting pressures, through the flowable filling material, in areas of the body other than the ischia or seat bones.
The removably securable supports can be selectively placed over and adhered to the side rims, the modified front rim and the central rise to augment the general shape of each of those areas and consequently provide more aggressive positioning of a human being on the cushion.
In the preferred embodiment, the supports consist of two mirror image wedge shaped supports adapted to be placed on the upper most front corners of the front rim to adduct or maintain one or both of the user's legs within leg support areas; two mirror image modified wedge shaped hip guides adapted to be adhered to the back corner side rims of the tray and following the concave curve of the slope of the side rims to guide and maintain the user's hips into the depressed area; two mirror image "pelvic obliquity" supports adapted to be adhered to the back corners of the side rims of the tray and providing an augmented or built up surface to raise one side of the pelvis and prevent problems associated with leaning; and a generally bulbous shaped support, contoured and adapted to be secured to and augment the central rise of the front rim to separate the user's legs and urge the user's legs into their respective support areas.
In the preferred embodiment, the top and bottom surfaces of the supports are equipped with fabric hook and look fasteners, such as velcro strips to secure the selected supports to their respective areas and to secure the pad to the augmented tray. Other means of fastening include the use of glue to glue the supports into place.
In one embodiment, the pad which is adapted to contain the fluid filling material, is a flexible envelope fabricated from an extensible elastomeric material, such as thermoplastic polyurethane film. The fluid filling material is preferably a high viscosity, thixotropic material which will flow under pressure, but which will maintain its shape in the absence of pressure.
The flexible envelope containing the fluid filling material is anchored to the exposed surfaces of the tray and supports and the underlying tray in such a manner that it is restrained from sliding forward. This anti-sliding restraint, in combination with the other seat design features described herein, reduces the tendency of the user to slide forward and the consequential slumping deformities. Basically, through fastening the cushion, the tendency of the cushion to slip forward is obviated and the consequent tendency of the user to slip forward is substantially eliminated.
Moreover, the other features of the cushion also cooperate to reduce the tendency to slump. It is well known that slumping is a reaction to nonstability. An envelope filled with a non-compressible thixotropic filling produces a much more stable seat, which decreases the tendency toward slumping which occurs when a person is seated on an unstable surface. Moreover, in the preferred embodiment, the tray which has a slightly raised portion for the legs and a depressed portion for the ischial tuberosities also has a marked tendency to reduce the tendency to slump, as the seat portion of the cushion is slightly lower than the leg portion in the preferred embodiment.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the seat cushion combination illustrating supports adhered to the shaped tray and illustrating a support, separated from, but juxtaposed above, the shaped tray;
FIG. 2 is a cross sectional front view of the seat cushion; and
FIG. 3 is an isometric view of the seat cushion combination illustrating the pad separated from, but juxtaposed above, the shaped tray.
DETAILED DESCRIPTION OF THE INVENTION
The combination seat cushion 10, without pad 20 is shown in FIG. 1. The combination seat cushion is shown in FIG. 3. Seat cushion 10 is generally comprised of pad 20, tray 40 and any combination of supports 22, 23, 29, and 34.
The Shaped Tray
Tray 11 is preferably a relatively rigid, but light weight material. While urethane foams of various density have been employed, the tray could be manufactured from any convenient material such as plastic, wood, metal, or the like. It is generally desired to include a non-slip lower surface (not shown) and built in (e.g. molded) carrying handles (not shown). The tray must be wide enough to support a human being. Trays of about 15.5 inches or 18 inches width are suitable because they fit most persons and may be used in standard size wheelchairs. Smaller sizes, such as 12 inch or 14 inch width may be fabricated for children. The invention is not limited to any specific size.
The shape of the tray 11 is critical. It is generally essential to have depressed seat area 12 surrounded by rims 14 and 16 on each side and rim 18 on the front. A modified front rim 18 is preferably deeper, e.g., (extends from a front edge approximately 40% of the distance of the back edge of the tray) with a central rise 19 adapted to spread the user's legs and urge the user's legs into support areas 20. The rear portion of the tray should be open, i.e., no rim at the back in order to avoid building pressure in the area of the coccyx. Because the distance between the ischial tuberosities in adults is between 4.5 and 6 inches, the cut out at the rear of the tray must be at least 6 inches wide, and is preferably at least 8 inches wide in order to provide for a certain amount of shifting from side to side of the user. Generally it is desired that the user have from 1 to 3 inches room to shift from side to side and from 1 to 5 inches room to shift from front to back. This allows the user to shift position without developing any undesired pressures from the tray.
As shown in FIGS. 2 and 3, the side rims 14 and 16 are essentially vertical on the outside of tray 11, but are sloped inwardly, generally toward the seat portion 12 on the inside of the tray. Similarly, the front rim 18 is relatively vertical on the outside at tray 10, but sloped gradually inwardly and downwardly toward the seating area 12, on the inside of the tray.
This tray is of the sort disclosed in U.S. Pat. Nos. 4,588,229 and 4,726,624.
The Supports
In the preferred embodiment, the supports 22, 23, 29, and 34 are preferably a relatively rigid, lightweight material. While urethane foams of varying density have been used, the supports can be manufactured from any convenient material such as plastic, wood, metal or the like.
Depending on the positioning or posturing needs of a person, one or more of the supports may be adhered to the tray 11, thereby enhancing or exaggerating the contours of the tray to assist in the correction of a specific posture problem. A support may be used alone or in varying combinations with any of the other supports.
Generally, the supports must be shaped to cooperate with and augment the contours of the tray while providing a smooth and comfortable seating surface.
In the preferred embodiment, support 22, has a generally bulbous upper shape and a base contoured to the shape of the central rise 19, cooperates with the central rise 19, and is adapted to spread the user's legs and urge the user's legs into support areas 20. The bulbous protrusion of support 22 from the central rise 19 prevents the user's legs from coming too closely together and prevents one leg from sliding over the central rise 19 into the other leg's support area 20.
In the preferred embodiment, support 23 is generally wedged shaped, having a concave upper face 24, a vertical face 25 and a flat bottom face 26 substantially perpendicular to the vertical face 25. The upper concave face 24 and the flat bottom face 26 meet to form an apex 27, and depending from an end 31 is a point 28 formed by the apex 27 approaching the vertical face 25 in a manner whereby a blunt tip is formed. The flat bottom face 26 is fastened to and cooperates with the front corner 13 portions of the tray with the blunt tip pointing towards the back of the tray. When in place, support 23 presents a surface that is upwardly curving in the sides of the front corners of the tray which urges the user's legs into the support areas 20 and prevent the user's legs from spreading too far apart or slipping over the sides of the tray 11.
In the preferred embodiment, support 29 has a compound upper surface 30 which is substantially concave and a compound bottom surface 31 approximately contoured to matingly engage one or both of the side rims 14 and 16 of the tray. Support 29 is adhered to the back corner portions 15 and 17 of the tray following from the top 32 of the rims 14 and 16 down the slope of the rim 33 to where the rim meets the depressed seating area so that when installed the upper surface of support 29 substantially smoothly converges with the exposed surface of the depressed seating area 12 in such a manner that the transition from the upper surface 30 of the support to the surface of the tray is smooth and precludes presentation of a pressure point. Support 29 engages either or both hip areas of the user to prevent the hips of the user from sweeping to either side of the seating area 12.
In the preferred embodiment, support 34 has two substantially parallel upper 35 and lower faces 36. The lower face 36 curves upwardly to intersect the upper face 35 at the front 37 and first side 38 of the support 34. The upper face 35 curves downwardly to intersect the lower face 36 on a second side 39. The rear 40 of the support is a planar surface substantially perpendicular to the upper 35 and lower 36 faces. Support 34 is adapted to be adhered to either or both of the back outer corners 15 and 17 of the tray. When installed support 34 elevates the inner slope 33 of the rims 12 and 14 from the top of the rim 32 to where the rims 14 and 16 and the depressed seating 12 area meet and presents a more plane surface than the existing surface of the rim slope. Support 34 is designed to raise one side of the pelvis of the user to a point level with the other side to prevent pelvic obliquity and ultimately scoliosis.
Depending on the particular posturing needs one of more of the supports ma be used to alter the seating surface of the tray to effect a particular posture correcting surface.
In the preferred embodiment, supports 22, 23, 29, and 34 are equipped with fasteners 41, such as velcro, on both upper and lower faces to fasten two supports to the tray and to provide a non-slip surface for the pad.
The Pad
In the preferred embodiment, the pad 42 is an envelope fabricated from an elastic material and contains fluid filling material such as a highly viscous liquid, i.e., plastic or viscous thixotropic material, but which maintains its shape and position in the absence of pressure. One such viscous fluid is commercially available under the trade name FLOLITE , the registered trademark of Alden Laboratories. ALthough FLOLITE is a preferred fluid, fluids such as water and air also may be utilized. Other suitable flowable materials are described and claimed in: U.S. Pat. Nos. 4,229,546 and 4,243,754. Representative pads which may be used with this invention are described in U.S. Pat. Nos. 4,588,229 and 4,726,624.
The pad 42 need not be attached to the tray 11, but such attachment is preferred. Center attachment 43, which may be a fabric hook and loop fastener, at the rear of the pad is desired in order to prevent the pad from slipping forward, as this may be the sole attachment means. Preferably the rear edge of the pad is also attached to the inward sloping portion of side rims with velcro strips 41.
This invention can also be adapted to a seat back cushion for positioning and posture correction of the back and/or neck of a seated individual.
From the foregoing description, it is apparent that the present invention provides a customizable seat cushion which may be adapted to suit the particular positioning needs of an individual in a wheelchair. While the preferred embodiment has been described, it should be understood that various changes, modifications, and adaptations may be made therein without departing from the spirit of the invention and the scope of the appended claims.
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A customized seat cushion for the human body comprises securable, removable supports which are used in combination with a shaped tray and a pad containing a fluid filling material. In the preferred embodiment, the supports are fastened to selected contours of the shaped tray, and the surface presented by the supports and shaped tray are covered by the pad which is fastened to the exposed surfaces of the tray and pads to form a customized seat cushion.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to tractor-mounted bulldozer blades and, more particularly, to a combined cushioning and hydraulic stabilizing linkage for said blade.
2. Description of the Prior Art
In certain uses of tractor-mounted bulldozer blades, it is desirable that the loading of the blade be maintained substantially uniform across the width of the blade while still having some cushioning of the blade to absorb some of the shock administered to the blade when the blade makes contact, for instance, with a push block of a scraper.
There are currently available bulldozer blade-mounting assemblies employing hydraulic cylinders between the push frame and the blade, but, the assembly does not include any cushioning arrangement whereby shocks on the blade can be absorbed without being transmitted through the push frame to the tractor.
In another known device, the bulldozer blade has separate cushioning means and tilt cylinders mounted between the blade and the tractor. The tilt cylinders function to tilt the blade for certain purposes while the separate cushioning means serve to absorb shock loads on the blade.
These prior devices, although completely effective for their intended use, do require separate elements for cushioning and for stabilizing, which increases the number of parts, adds expense, and increases the complexity of building and maintaining the equipment.
SUMMARY OF THE INVENTION
The present invention is directed to overcoming one or more of the problems set forth above.
According to the present invention, an improved linkage assembly is provided for a cushioned bulldozer blade. The linkage is used to replace the tilt cylinders and to replace a separate cushioning means between the blade and the tractor. The combined cushioning and stabilizing linkage assembly has a pair of links, with each link positioned on a diagonal between the push frame and the blade. Each link has resilient or spring members for cushioning shocks received by the bulldozer blade and has a hydraulic cylinder portion with the hydraulic portions of the pair of links cross connected such that the two links operate together to equalize and stabilize the loads on the blade.
The improved combined cushioning and stabilizing linkage assembly reduces the complexity of the blade mounting system, thereby making it less expensive to build and to maintain.
BRIEF DESCRIPTION OF THE DRAWINGS
The details of construction and operation of the invention are more fully described with reference to the accompanying drawings which form a part hereof and in which like reference numerals refer to like parts throughout.
In the drawings:
FIG. 1 is a perspective view of a tractor with a cushion bulldozer blade and a linkage assembly incorporating the combined cushioning and stabilizing apparatus of the invention;
FIG. 2 is an enlarged cross-sectional view taken along the line 2--2 of FIG. 4;
FIG. 2a is an exploded partial perspective view of the assembly of the fixed wall in the link;
FIG. 3 is a plan view of one link of the linkage assembly showing the connection between the push frame and the bulldozer blade;
FIG. 4 is an elevational view of the apparatus of FIG. 3; and,
FIG. 5 is a schematic showing of the two links and the hydraulic interconnection therebetween.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring generally to FIG. 1 of the drawings, a tractor 10 is illustrated and has a track roller frame 12 operatively connected thereto. A push arm 14 of a push frame is shown connected by means of a trunnion and bearing assembly 16 to the track roller frame 12 at one end portion thereof, with the other end portion of the arm 14 having a bifurcated extension 18 pivotally connected by a pin 20 to a lug 22 carried by the bottom rear corner of the bulldozer blade 24. A second push arm 14 is mounted on the opposite side of the tractor 10 with the two push arms making up the push frame. A pair of lift cylinders 26, only one of which is shown, are connected between the tractor main frame 28 and a pair of brackets 30 (FIG. 4) on the rear of the bulldozer blade 24 and are used for raising and lowering the blade 24 relative to the ground. A combined cushioning and stabilizing linkage assembly 32 has a pair of links 34 on each side of the tractor 10 with each link 34 being pivotally mounted at one end portion to the push arm 14 and being pivotally mounted at its other end portion to a pair of spaced apart brackets 36 carried by the upper rear corner portions of the bulldozer blade 24.
FIGS. 2 through 5 will now be referred to and, in particular, with reference to the details of the combined cushioning and stabilizing link 34. For the present purpose, only one link 34 will be described, but it is understood that each link 34 connected between the push arms 14 and the blade 24 on each side of the tractor 10 are identical in construction.
The link 34 is comprised of a cylinder 38 which is divided into three portions, a cushioning portion 37, a midportion 39 and a hydraulic portion 41. A mounting cap 40 is either welded or integrally formed on the cushioning portion 37 of the cylinder 38. The mounting cap 40 has an eye 42 extending transversely therethrough, which eye 42 receives a pin 44 passing through aligned apertures 46 in upstanding spaced apart walls of a bracket 48 welded or otherwise secured to the top surface of each push arm 14. Longitudinally spaced from a conically-shaped inside wall 50 of the mounting cap 40 is a fixed wall 52 which, as shown in FIG. 2, is disc-shaped and includes a flange portion 54 extending radially outwardly beyond the walls of the cylinder between the cushioning portion 37 and the midportion 39. A ring 56 is welded on the end of the cushioning portion 37 and a second ring 57 is welded on the end of the midportion 39, said rings being juxtaposed on opposite sides of the flange 54 of the fixed wall 52. A plurality of elongate bolts 59 pass through aligned openings 61 in the rings 56, 57 and fixed wall 52 in a manner to be described hereinafter. A second fixed wall 58, longitudinally spaced from the first fixed wall 52 is positioned between the midportion 39 and the hydraulic portion 41 of the cylinder 38 and has a flange portion 60 extending beyond the walls of the cylinder 38. A ring 62 is welded to the end of the midportion 39 with a second ring 63 being welded to the end of the hydraulic portion 41. The rings 62, 63 are juxtaposed on opposite sides of the flange 60 with bolts 65 passing through aligned openings 67 in said rings 62, 63 and flange 60 and being drawn up tight to securely fix the wall 58 relative to the cylinder 38. The fixed walls 52 and 58 have centrally disposed, aligned apertures 64 and 66, respectively, with aperture 66 having a larger diameter for a purpose to be described hereinafter. The fixed walls 52 and 58 divide the cavity in the cylinder 38 into three chambers, a cushioning chamber 69, a bottoming chamber 71 and a hydraulic chamber 73.
An elongate actuating rod 68 extends through an apertured end cap 70 which is secured by bolts 75 to a ring 77 welded to the end of the cylinder 38. The rod 68 extends through an aperture 72 in the end cap 70 and projects into the cylinder 38. The extended end portion 74 of the rod 68 has a crutch 76 engaging with a dumbbell 80 carried by the bracket 36 mounted on the blade 24. A cap 78 is bolted to the crutch 76 to secure the rod 68 to the blade 24 with a universal connection to permit movement between the links and the blade without binding.
The rod 68 passes through the aperture 72 in the cap 70 and through the fixed wall 58. Beyond the wall 58, the diameter of the rod 68 becomes smaller forming a shoulder 82 between the large diameter portion 84 and the small diameter portion 86. The small diameter portion 86 extends through the fixed wall 52 and has an undercut portion 88 in which is seated a disc-shaped cushioning piston 90. The concave side of the disc-shaped piston 90 faces the convex side of the conical wall 50 on the cap 40.
A plurality of disc-shaped or frustoconically-shaped cushion elements 92 are stacked one against the other in the cushioning chamber 69 of the cylinder 38 with the apertures 94 in the discs or elements 92 aligned with each other. The discs or elements 92 are made of a resilient material, such as rubber, and would have a high durometer hardness. The one end disc 92 bears against and mates with the conical surface 50 on the cap 40 with the disc 92 on the opposite end of the stack mating with the conical shape of the piston 90.
Additional discs or elements 93, two being shown, fit between the piston 90 on the rod 68 and the fixed wall 52. With the uncompressed discs 92 and 93 stacked in the chamber 69 in the cushioning portion 37 of the cylinder 38, the piston 90 and the fixed wall 52 are located axially outside the end of the cushioning chamber 69. The elongate bolts 59 are threaded through the openings 61 in the ring 56, in the flange 54 of the fixed wall 52 and in the ring 57 on the midportion 39 whereupon nuts are threaded on the bolts 59 and are drawn up to compress the discs 92 and 93. When the nuts on the bolts 59 are drawn up tight so as to abut the rings 57 and 56 against the flange 54 of the wall 52, the discs 92, 93 will be preloaded the desired amount. Increased or decreased preloading can be affected by increasing or decreasing the number of discs 92 and/or 93 inserted in the chamber 69. A cylindrically-shaped stop 96 is anchored to the conical surface 50 of the end cap 40 and projects through the aligned apertures 94 in the discs 92, 93 toward the end of the rod 68. With the discs 92 assembled, as shown, a space is provided between the stop 96 and the rod 68 for a purpose to be described hereinafter.
A disc-shaped plate 98 encircles the small diameter portion 86 of the rod 68 in the chamber 71 of the midportion 39 of the cylinder 38 and is held separated from the fixed wall 52 by a plurality of resilient discs or elements 95, three discs 95 being shown in the drawing. The plate 98 is spaced from the shoulder 82 on the rod 68 when the resilient discs or elements 92 in chamber 69 are in the static condition of FiG. 2. The large diameter portion 84 of the rod 68, where it passes through the aperture 66 in the second fixed wall 58, is intended to be a fluid-tight sliding connection so that the area on opposite sides of the second fixed wall 58 are substantially sealed from each other. The large diameter portion 84 of the rod 68 has a hydraulic piston 100 rigidly secured thereto, which piston 100 is disposed in the chamber 73 of the hydraulic portion 41 of the cylinder 38 which portion is formed by the end cap 70 and the second fixed wall 58. The piston 100 being fixed to the rod 68 will be moved with the rod in said chamber 73 and divides the chamber into a rod end 102 and a head end 104.
As shown in FIG. 5, the hydraulic pistons 100, 100 in the chambers 73, 73 are plumbed in such a way that the head end 104 of the piston 100 is the right-hand link 34 is connected through tubing 108 to the rod end 102 of the piston 100 in the left-hand link 34. Also, the rod end 102 of the right-hand link 34 is connected by tubing 106 to the head end 104 of the chamber 73 on the left-hand link 34. The two tubes 106, 108 are interconnected by a bypass tube 110, which bypass 110 contains a valve 112 for shutting off the flow therebetween. A filling valve 114 is provided in tube or line 106 through which hydraulic fluid is added to the system initially, or when needed to replace lost fluid. The valve 112 is opened when the system is being filled or when equalizing or balancing the system.
With the two links 34 connected between the push arms 14 of the push frame and the upper rear corners of the blade 24, a linkage assembly is provided which, not only cushions the blade 24, but also stabilizes the blade. That is, a blow on the blade 24 slightly off-center will depress both links 34 with the shock of the blow being transmitted through the rods 68 to the pistons 90 in the chambers 69, which will compress the stack of resilient elements or discs 92 in the chambers 69. In the event the shock is excessive, the shoulder 82 on the rod 68 will engage with the plate 98 and compress the resilient discs 95 between the plate 98 and the fixed wall 52 to provide a resilient bottoming of the blade. If the shock is so severe as to extensively compress the discs 95 and discs 92, the rod 68 will bottom by engaging the stop 96 on the cap 40 to prevent crushing of the discs 95 and 92 beyond recovery. To prevent damage caused by rebound of the discs 92 and sometimes discs 95, the discs 93 between piston 90 and wall 52 will absorb any tendency for the rod 68 to be driven too rapidly to the right (in FIG. 2) upon recovery of the compression of the discs 92 and sometimes discs 95.
In the meantime, the pistons 100 will attempt to compress the hydraulic fluid in the head ends 104 of the pistons 100 and, since the blow was assumed to be offcenter, one piston 100 will have excessive pressure over the other piston 100 which will cause fluid to flow from the head end 104 of the higher pressure side through the tubing to the rod end 102 of the opposite piston 100 adding further force to the piston 100 on the deficient side of the system. Independent forces will act on each link so as to produce a given deflection in each link which deflection will be equal on each link. Any tendency for an imbalance of deflection on one link will immediately be compensated for by the hydraulic system to restore a balance of deflections to both links.
The discs 92 and 95 are preloaded between the cap 40 and the fixed wall 52 which will keep the lengths of the links 34 constant under no load condition and will compensate for some leakage of hydraulic fluid past the pistons 100.
A wear plate 116 is mounted on the side of each track roller frame 12 with each plate being in alignment with a wear shoe 118 mounted on the inside of each push arm 14 of the push frame. The wear plate 116 and wear shoe 118 cooperate to provide some lateral stability to the push frame and blade 24.
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A bulldozer blade mounting assembly is provided for mounting a bulldozer blade on the front of a tractor. The mounting assembly includes a push frame connected between the tractor and the lower portions of the blade. A combined cushioning and stabilizing linkage assembly is provided with a link extending diagonally between each push arm of the push frame and the upper rear corner portions of the blade. The stabilizers on each link are interconnected with a closed loop hydraulic system so as to ensure that any deflection in one link must also occur in the opposite link.
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TECHNICAL FIELD
This disclosure relates generally to printers having an intermediate imaging member and, more particularly, to the components and methods for facilitating removal of media from an offset imaging member or other cylindrical roller, such as a fuser roller.
BACKGROUND
In known printing systems having an intermediate imaging member, the print process includes an imaging phase, a transfix phase, and an overhead phase. In inkjet printing systems, the imaging phase is the portion of the print process in which the ink is expelled from the print head in an image pattern onto a print drum or other intermediate imaging member. The transfix phase is the portion of the print process in which the ink image on the print drum is transferred from the intermediate imaging member to the recording medium. The image transfer typically occurs by bringing a transfix roller into contact with the imaging member to form a nip. A recording medium arrives at the nip as the print drum rotates the image through the nip. The pressure in the nip helps transfer the malleable image inks from the print drum to the recording medium. In the overhead phase, the trailing edge of the recording medium passes out of the nip and the transfix roller is released from contacting the imaging member. The removal of the transfix member helps release the media from the intermediate imaging member. In some intermediate imaging printers, a stripper blade may be moved into position to intervene between the leading edge of a media leaving the transfix nip and the intermediate imaging member to facilitate separation of the media from the intermediate imaging member.
Inkjet printers that use intermediate imaging members, sometimes called offset printers, have been developed with higher throughput rates. Some of these printers have intermediate imaging members that have larger circumferences than previously known printers. The high transfix load pressure and the speed of the intermediate imaging member in higher throughput printers lead to high adhesive forces between the media and the intermediate imaging member. These adhesive forces make stripping the media from the intermediate imaging member with known stripping systems more difficult. A system that separates media with a higher adhesion force from an intermediate imaging member benefits the field of offset printing.
Other known cylindrical roller systems are used to fuse toner onto media after transfer of an image to the media. These fuser rollers can generate high pressure to enable the use of lower roller temperatures. When media passes through a fusing nip generating high pressure, the media can adhere to the roller and make media stripping a challenge. A system that separates media with high adhesion force from a high pressure fuser roller benefits the field of high pressure fusing.
SUMMARY
A stripper blade system has been developed that reliably strips media from an intermediate imaging member in an inkjet printer. The stripper blade system includes a metallic blade having a leading edge that is less than 0.06 millimeters in thickness, a blade holder to which the metallic blade is mounted, and an actuator that is associated with the blade holder to move the metallic blade into and out of contact with an intermediate imaging member.
The stripper blade system may be adapted for use in a xerography system to strip media from a fuser roller. The stripper blade system for a xerography system includes a metallic blade having a leading edge that is less than 0.06 millimeters in thickness, a blade holder to which the metallic blade is mounted, a stop member mounted proximate a fuser roller, and an actuator that is associated with the blade holder to move the metallic blade into and out of contact with the stop member to bias the leading edge of the metallic blade against the fuser roller to enable stripping of media from the fuser roller after the media exits a nip formed with the fuser roller.
A method that may be implemented with the stripper blade system includes moving a blade holder attached to a stainless steel blade having a leading edge with a thickness of no more than 0.06 millimeters to a position that enables the leading edge of the stainless steel blade to contact a cylindrical roller to facilitate separation of a leading edge of media on the cylindrical roller from the cylindrical roller, and moving the blade holder after expiration of a predetermined time period to disengage the leading edge of the stainless steel blade from the cylindrical roller.
A printer includes a print drum for receiving ink ejected by a print head, a transfix roller located proximate to the print drum, a stripper blade system, and a controller. The stripper blade system includes a metallic blade having a leading edge that is less than 0.06 millimeters in thickness, a blade holder to which the metallic blade is mounted; and an actuator that is associated with the blade holder to move the metallic blade into and out of contact with the print drum. The controller is configured to operate the transfix roller to form a transfix nip with the print drum selectively and to move the blade holder to contact the print drum with the leading edge of the metallic blade with the print drum to facilitate removal of media from the print drum.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and other features of an inkjet printer implementing a stripper blade system are explained in the following description, taken in connection with the accompanying drawings, wherein:
FIG. 1A is a side view of a stripper blade system where the leading edge of a metallic stripper blade is in contact with a print drum.
FIG. 1B is a side view of a stripper blade system where the leading edge of a metallic stripper blade is removed from a print drum.
FIG. 2 is a perspective view of a stripper blade.
FIG. 3 is a cross-sectional view of an alternative stripper blade.
FIG. 4 Ais a front side view of a print drum with a media sheet and a stripper blade with a uniform leading edge.
FIG. 4B is a front side view of a print drum with a media sheet and a stripper blade with a tapered leading edge.
FIG. 5 is a flow diagram of a process for controlling a stripper blade system.
FIG. 6 is a side view of a stripper blade system that engages a fuser roller to enable separation of media from the fuser roller after the media exits a nip between the fuser roller and a pressure roller.
FIG. 7 is a side view of a prior art inkjet printer.
DETAILED DESCRIPTION
Referring to FIG. 7 , there is shown a side view of a prior art inkjet printer 10 that may be modified to include a stripper blade system that reduces undesirable ink transfer during the printing process. The reader should understand that the embodiment of the print process discussed below may be implemented in many alternate forms and variations. In addition, any suitable size, shape or type of elements or materials may be used.
As shown in FIG. 7 , the inkjet printer 10 may include an ink loader 40 , an electronics module 44 , a paper/media tray 48 , a print head 50 , an intermediate imaging member 52 , a drum maintenance subsystem 54 , a transfix subsystem 58 , a wiper subassembly 60 , a paper/media preheater 64 , a duplex print path 68 , and an ink waste tray 70 . In brief, solid ink sticks are loaded into ink loader 40 through which they travel to a melt plate (not shown). At the melt plate, the ink stick is melted and the liquid ink is diverted to a reservoir in the print head 50 . The ink is ejected by piezoelectric elements to form an image on the intermediate imaging member 52 as the member rotates. Member 52 is called an intermediate imaging member because an ink image is formed on the member and then transferred to media in the transfix subsystem. This printing process is a type of offsetting printing. The intermediate imaging member may also be called a print drum.
An intermediate imaging member heater is controlled by a controller to maintain the imaging member within an optimal temperature range for generating an ink image and transferring it to a sheet of recording media. A sheet of recording media is removed from the paper/media tray 48 and directed into the paper pre-heater 64 so the sheet of recording media is heated to a more optimal temperature for receiving the ink image. A synchronizer delivers the sheet of the recording media so its movement between the transfix roller in the transfer subsystem 58 and the intermediate image member 52 is coordinated for the transfer of the image from the imaging member to the sheet of recording media.
The operations of the inkjet printer 10 are controlled by the electronics module 44 . The electronics module 44 includes a power supply 80 , a main board 84 with a controller, memory, and interface components (not shown), a hard drive 88 , a power control board 90 , and a configuration card 94 . The power supply 80 generates various power levels for the various components and subsystems of the inkjet printer 10 . The power control board 90 regulates these power levels. The configuration card contains data in nonvolatile memory that defines the various operating parameters and configurations for the components and subsystems of the inkjet printer 10 . The hard drive stores data used for operating the inkjet printer and software modules that may be loaded and executed in the memory on the main card 84 . The main board 84 includes the controller that operates the inkjet printer 10 is configured in accordance with an operating program executing in the memory of the main board 84 . The controller receives signals from the various components and subsystems of the inkjet printer 10 through interface components on the main board 84 . The controller also generates control signals that are delivered to the components and subsystems through the interface components. These control signals, for example, drive the piezoelectric elements to expel ink from the print heads to form the image on the imaging member 52 as the member rotates past the print head. The printer depicted in FIG. 7 is merely exemplary of a printer suitable for adaptation with a stripper blade system, and the stripper blade system described herein may be used in a variety of printers with alternative components and configurations. Furthermore, the stripper bade system described herein can also be used in other printer subsystems such as roll fusers, belt fusers, etc.
A stripper blade system configured to remove print media from an intermediate imaging member or other cylindrical roller, such as a fuser roller or an unheated roller that contacts printed media, is depicted in FIGS. 1A and 1B . FIG. 1A shows the stripper system 100 A with the stripper blade 112 biased against the surface of an intermediate imaging member, herein embodied as a print drum 108 . FIG. 1A and FIG. 1B show the print drum configured to rotate in a counterclockwise direction shown by arrow 102 . In the embodiment of FIG. 1A , the stripper blade 112 is biased against the surface of the print drum 108 at location 148 with a pressure of approximately 0.033 lb/in to about 0.083 lb/in. The stripper blade 112 is deformed by the biasing force, and the acute angle formed at location 148 between the print drum 108 and stripper blade 112 is between approximately 10 and 14 degrees. This angle is also known as the “angle of attack”, and in the example embodiment these angle of attack ranges facilitate separating a print medium from the print drum 108 . The deformation results in the stripper blade 112 having a curvature when biased against the print drum 108 . The curvature allows the leading edge of stripper blade 112 to engage the print drum 108 uniformly. The stripper blade 112 has at least one metallic layer, which may be formed from stainless steel, although other materials may be used. The surface of print drum 108 is also metallic, typically being anodized aluminum. Generally, the stripper blade has a thickness of about one-half the thickness of the media most commonly used in the printer. In one embodiment, the media has a thickness of about 0.1 mm so the stripper blade has a thickness of about 0.06 mm.
The stripper blade 112 is attached to a blade holder 116 . The blade holder 116 may be formed from a polymer compound, such as a thermoplastic adapted to secure the stripper blade 112 , although other suitable materials may be used. The blade holder 116 engages a support arm 124 that is rotatably attached to a pivot 120 at one end and a spring 136 at the other end. The spring 136 is further attached to an actuator arm 132 . The actuator arm 132 is controlled by an actuator 128 , which is typically an electromechanical device such as a servo or solenoid. In the configuration of FIG. 1A , the actuator arm 132 is in a retracted position, pulling the spring 136 , support arm 124 and blade holder 116 towards a stop member 140 . The stop member 140 applies a reverse bias against the blade holder 116 . The forces from actuator 128 and stop member 140 maintain the biasing pressure of approximately 0.033 lb/in to 0.083 lb/in as the print drum 108 rotates and the stripper blade 112 engages media sheets.
FIG. 1B depicts a stripper blade system 100 B with the stripper blade 112 removed from the print drum 108 . In this disengaged position, a gap 152 is formed between the stripper blade 112 and print drum 108 . The actuator 128 extends actuator arm 132 , pivoting support arm 124 and blade support 116 away from mechanical stop 140 . As the blade support 116 moves away from the print drum 108 , the end of the arm 116 furthest away from the print drum 108 moves to encounter the stop member 144 . Thus, stop member 144 limits the travel of the blade support 116 during disengagement of the blade 112 from the drum 108 and the stop member 140 limits the travel of the blade support 116 during engagement of the blade 112 with the drum 108 .
In both FIG. 1A and FIG. 1B the transfix roller 104 is positioned to form a transfix nip 110 with print drum 108 . The transfix roller 104 may be moved into the nip position or removed from the nip position by rotation of a transfix roller actuator 156 . The transfix roller 104 rotates freely about a central axis 164 in response to the rotation of the print drum 108 , allowing media sheets to pass through the transfix nip 110 . In the embodiment of FIG. 1A and FIG. 1B , the transfix roller actuator 156 engages the transfix roller 104 using at least one armature 160 , although alternative embodiments may use other means of moving the transfix roller such as belts or a gearing system. The transfix roller actuator 156 is typically an electromechanical device such as an electric motor. The transfix roller actuator 156 may also rotate armature 160 and transfix roller 104 to a position removed from the transfix nip 110 when the printer is not transfixing an image to a print medium. When the transfix nip 110 is formed, the print drum 108 rotates in direction 102 , carrying a media sheet through the transfix nip 110 towards the stripper blade 112 . If the stripper blade 112 is engaged as show in FIG. 1A , the media sheet is separated from the print drum 108 starting at location 148 .
The actuator 128 and transfix roller actuator 156 are both configured to operate in response to signals received from a controller (not shown). The controller may be a general purpose microprocessor that executes programmed instructions that are stored in a memory. The controller also includes the interface and input/output (I/O) components for receiving status signals from the printer and supplying control signals to the printer components. Alternatively, the controller may be a dedicated processor on a substrate with the necessary memory, interface, and I/O components also provided on the substrate. Such devices are sometimes known as application specific integrated circuits (ASIC). The controller may also be implemented with appropriately configured discrete electronic components or primarily as a computer program or as a combination of appropriately configured hardware and software components.
A stripper blade that may be used in the embodiment of FIG. 1A and FIG. 1B is depicted in FIG. 2 . The stripper blade 200 is formed from a single sheet of a flexible material such as stainless steel. In the example embodiment of FIG. 2 , the stripper blade 200 has a leading edge 204 adapted to contact an intermediate imaging member such as a print drum, which is typically made of anodized aluminum, although other materials may be used. The leading edge 204 depicted in FIG. 2 is 30 mm wide, although different lengths may be used in alternative embodiments. For the embodiment of FIG. 2 , the stripper blade 200 has a thickness 208 of approximately 0.05 mm, and a length 212 of 12 mm. These dimensions provide the stripper blade 200 with sufficient strength and flexibility to be biased against a print drum for the purpose of stripping a media sheet from the print drum as shown in FIG. 1A . The length 212 is also sufficient to permit the stripper blade 200 to be held by a stripper blade holder such as the stripper blade holder 116 depicted in FIG. 1A . In alternative embodiments, the precise dimensions of the stripper blade 212 may vary according to the desired width of the leading edge 204 , the desired angle of attack for the stripper blade, and material used to form the stripper blade. While the leading edge 204 of stripper blade 200 is depicted as a straight edge, alternative shapes such as a tapered edge forming a point in the leading edge are also envisioned.
A cross sectional view of an alternative embodiment of a stripper blade suitable for use with the system of FIG. 1A and FIG. 1B is depicted in FIG. 3 . The stripper blade 300 has a metal layer 312 laminated to a first polymer layer 308 . In the example embodiment of FIG. 3 , the metal layer 312 is typically formed from a sheet of metal such as stainless steel, and is 26 mm in length and is up to 0.051 mm thick. The first polymer layer 308 is typically formed of Mylar, and is recessed from the leading edge 314 such that metal layer 312 extends approximately 1 mm beyond the first polymer layer 308 . The first polymer layer 308 is 0.076 mm thick and is 25 mm wide. The second polymer layer 304 is also formed from Mylar and is approximately 0.229 mm thick and 22 mm wide. The second polymer layer is further recessed from the leading edge of the first polymer layer 308 by 3 mm. The polymer layers 304 and 308 are constructed with sufficient deformation range to allow the attached metal layer 312 to engage the print drum with a desired contact load and angle of attack, while providing enough stiffness to overcome force applied by print media being stripped from the print drum. As with the stripper blade 200 depicted in FIG. 2 , the stripper blade 300 may be biased against the print drum, and is configured to deform into a curved shape with an angle of attack between approximately 10 and 14 degrees when biased against the print drum. In the curved shape, the leading edge 314 of metal layer 312 contacts the print drum first, with polymer layer 308 and 304 contacting the print drum after the metal layer 312 .
While the stripper blades of FIG. 2 and FIG. 3 are described in detail, these are only examples of stripper blade configurations that are adapted for use in printers, and various alternative embodiments are envisioned. For example, the thickness of a stripper blade may vary according to multiple factors including the desired degree of blade deformation and the thickness of media sheets that are expected to pass through the printer. For printers configured to print to thicker media, such as cardboard, the preferred thickness for a stripper blade may be thicker than the precise embodiment disclosed above. The angle of attack and biasing pressure may also be adjusted in printers having differing print drum diameters and rotational speeds. Various appropriate materials, such as aluminum or alternative polymers, may be substituted for use in the stripper blade in alternative printer designs as well.
FIG. 4A and FIG. 4B depict frontal views of two alternative stripper blade arrangements suitable for use with the stripper blade system depicted in FIG. 1A and FIG. 1B . In FIG. 4A , the stripper blade 416 has a horizontally uniform leading edge and is held by blade holder 412 . The print drum 404 rotates, carrying a media sheet 408 towards the stripper blade 416 . If the stripper blade 416 is biased against the print drum 404 , the stripper blade 416 separates the media sheet 408 from the surface of print drum 404 when the leading edge of the media sheet 410 meets the edge of the stripper blade 416 . In the alternative embodiment of FIG. 4B , the stripper blade 420 also engages the leading edge 410 of the media sheet 408 . In FIG. 4B , the stripper blade 420 has a tapered leading edge with an apex point 424 that engages the media sheet 408 first. As the print drum 404 carries media sheet 408 towards the stripper blade 420 , the tapered leading edge gradually engages the entire media sheet edge 410 , separating the media sheet 408 from the print drum 404 . In both FIG. 4A and FIG. 4B the stripper blade is approximately the same width as the print drum 404 . Either of the stripper blades exemplified in FIG. 2 or FIG. 3 may be adapted for use in FIG. 4A or FIG. 4B . The blade holder 412 may engage with an electromechanical actuator in the manner depicted in FIG. 1A and FIG. 1B .
A method for controlling a stripper blade system such as the system depicted in FIG. 1A and FIG. 1B is shown in FIG. 5 . The stripper blade control process 500 starts by moving the blade holder into the contact position (block 504 ). Moving the stripper blade holder causes the attached stripper blade to come in contact with an intermediate imaging member, such as a print drum. The stripper blade is biased against the intermediate imaging member prior to the arrival of the leading edge of a media sheet at the location where the stripper blade engages the intermediate imaging member (block 508 ). The biasing is accomplished by moving the stripper blade holder against a stop member, such as stop member 140 from FIG. 1A . The biasing force is applied for a predetermined period of time (block 512 ) where the stripper blade is held in the biased position (block 516 ). This predetermined period of time may vary depending upon factors such as the speed of the intermediate imaging member and the physical dimensions of the media sheet. The time should be sufficient to separate at least a leading portion of the media sheet from the intermediate imaging member such that the remaining portion of the media sheet will also separate from the intermediate imaging member. After the predetermined time period expires, the blade holder is moved to a remote position (block 520 ), removing the stripper blade from contact with the intermediate imaging member.
In operation, ink is ejected from at least one print head onto the surface of the print drum, forming a latent image. The transfix roller is moved into a transfix nip position with the print drum, and the print drum rotates, carrying a media sheet through the transfix nip to transfer the latent image from the print drum to the media sheet. The stripper blade is biased against the surface of the print drum at a position ahead of the leading edge of the media sheet after the leading edge of the media sheet emerges from the transfix nip. The stripper blade remains biased against the print drum for a predetermined amount of time allowing at least the leading portion of the media sheet to separate from the rotating print drum. At least a portion of the media sheet surface that was in contact with the print drum contacts the stripper blade as the media sheet separates from the print drum. The stripper blade is removed from contact with the print drum after sufficient time has passed to separate the media sheet from the print drum. The transfix roller is removed from the transfix nip after the media sheet has passed through the transfix nip. The process recited above may be repeated for multiple media sheets in a printer. Although the embodiments discussed above related to a stripper blade interacting with an intermediate imaging member, such as a print drum, the stripper blade may be used to facilitate the separation of printed media from other cylindrical rollers, such as heated rollers, i.e., fuser rollers, and unheated rollers in the media path.
In known xerography imaging systems, toner is attracted to electrical charge forming a latent image on an intermediate imaging member. The image is transferred to media and then the toner image on the media is fused to the media by passing the media with the toner image through a fusing nip formed between a fuser roller and a pressure roller. A fuser roller 604 and a pressure roller 608 are shown in FIG. 6 . In a typical xerography imaging system, the fuser roller is heated to a temperature in a range of about 80 degrees to about 120 degrees Celsius and the pressure generated in the nip is in a range of about 0.3 N/mm 2 to about 1 N/mm 2 . In previously known xerography systems, plastic fingers were used to strip media from the fuser roller. Metal blades having a width as wide as the fuser roller were not used because the relatively high temperature differences to which the full width metal blades were exposed induced severe process direction buckling. This buckling affected consistent placement of the leading edge of the stripper blade at a position relative to the nip position that was effective for stripping the media from the fuser roller. To overcome that issue, relatively narrow plastic fingers were used to strip the media from the fuser roller.
The stripper blade system 600 shown in FIG. 6 enables metallic blades to be used for stripping media from a fuser roller and still maintain consistent placement of the leading edge of the blade against the fuser roller. In the system 600 , the stripper blade 612 is biased against the surface of the fuser roller 604 , which is rotating in a counterclockwise direction shown by arrow 602 . As shown, the stripper blade 612 is biased against the surface of the fuser roller 604 at location 648 with a pressure of approximately 0.033 lb/in to about 0.083 lb/in. The stripper blade 612 is deformed by a biasing force supplied by the blade holder 616 being urged against stop member 640 by support arm 624 that is rotatably attached to a pivot 620 at one end and a spring 636 at the other end. An actuator 628 , which is typically an electromechanical device, such as a servo or solenoid, moves an actuator arm 632 to extend a spring 636 to urge the support arm 624 and blade holder 616 against the stop member 640 . The forces from actuator 628 and stop member 640 maintain a biasing pressure of approximately 0.033 lb/in to 0.083 lb/in as the fuser roller 604 rotates and the stripper blade 612 engages media sheets at an acute angle formed at location 648 between the fuser roller 604 and stripper blade 612 . In one embodiment, this angle is between approximately 10 and 14 degrees. This angle is also known as the “angle of attack”, and in the example embodiment, the angle of attack range facilitates separation of media bearing a toner image from the fuser roller 604 . The biasing of the stripper blade 612 curves the blade 612 and enables the leading edge of the stripper blade 612 to engage the fuser roller 604 uniformly. The stop member 644 operates to limit the range of motion for the blade holder 616 when the actuator 628 releases the spring 636 .
The stripper blade 612 has at least one metallic layer, which may be formed from stainless steel, although other materials may be used. The surface of the fuser roller 604 may also metallic, typically being anodized aluminum, although elastomer coated rollers may be used. Generally, the stripper blade has a thickness of about one-half the thickness of the media most commonly used in the xerography system. In one embodiment, the media has a thickness of about 0.1 mm so the stripper blade has a thickness of about 0.06 mm. The stripper blade 612 is attached to a blade holder 616 , which may be formed from a polymer compound, such as a thermoplastic adapted to secure the stripper blade 612 , although other suitable materials may be used.
In the embodiments described above, a single stripper blade has notable advantages over a plurality of discontinuous fingers for a number of reasons. For one, the discontinuous fingers may not successfully remove media if the media between the fingers remains adhered or substantially adhered to the roller. The single metallic blade is also better able to handle variable loading that varies with the degree to which the media is adhered to the roller from which the media is being removed. Additionally, the biasing and stop members enable the blade to engage the roller adequately for media removal without damaging the roller or the blade, particularly in metal-on-metal contact. The biasing force also enables a single metal blade to be used in a fuser environment without buckling occurring. Thus, the single metal blade and biasing mechanism provide reliable media stripping in a variety of imaging environments.
It will be appreciated that various of the above-disclosed and other features, and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.
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A stripper blade system has been developed for high throughput inkjet printers. The stripper blade system includes a metallic blade having a leading edge that is less than 0.06 mm in thickness, a blade holder to which the metallic blade is mounted, and an actuator that is associated with the blade holder to move the metallic blade into and out of contact with an intermediate imaging member.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 62/271,379 filed by the present inventors on Dec. 28, 2015.
[0002] The aforementioned provisional patent application is hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] None.
BACKGROUND OF THE INVENTION
[0004] Field of the Invention
[0005] The present invention relates to systems and methods for preparation and use of cold atmospheric plasma stimulated media for cancer treatment.
[0006] Brief Description of the Related Art
[0007] During the past decade, cold atmospheric plasma (CAP), a near room temperature plasma mainly composed of reactive oxygen species (ROS) and reactive nitrogen species (RNS), has been investigated for its promising application in anti-cancer therapy. See Kalghatgi, S. et al. Effects of non-thermal plasma on mammalian cells. PloS one 6, e16270 (2011); Ratovitski, E. A. et al. Anti-Cancer Therapies of 21st Century: Novel Approach to Treat Human Cancers Using Cold Atmospheric Plasma. Plasma Processes and Polymers 11, 1128-1137 (2014); and Fridman, G. et al. Floating Electrode Dielectric Barrier Discharge Plasma in Air Promoting Apoptotic Behavior in Melanoma Skin Cancer Cell Lines. Plasma Chemistry and Plasma Processing 27, 163-176 (2007). So far, CAP has shown a significant anti-cancer capacity over a wide range of cancer cell lines, including carcinomas, melanomas, neuroectodermal malignancies, and hematopoietic malignancies. See, Ahn, H. J. et al., “Atmospheric-pressure plasma jet induces apoptosis involving mitochondria via generation of free radicals,” PloS one 6, e28154 (2011); Yan, X. et al., “Plasma-Induced Death of HepG2 Cancer Cells: Intracellular Effects of Reactive Species,” Plasma Processes and Polymers 9, 59-66 (2012); Kim, G. C. et al., “Air plasma coupled with antibody-conjugated nanoparticles: a new weapon against cancer,” Journal of Physics D: Applied Physics 42, 032005 (2009); Lee, H. J. et al., “Degradation of adhesion molecules of G361 melanoma cells by a non-thermal atmospheric pressure microplasma,” New Journal of Physics 11, 115026 (2009); Tanaka, H. et al., “Plasma-Activated Medium Selectively Kills Glioblastoma Brain Tumor Cells by Down-Regulating a Survival Signaling Molecule, AKT Kinase,” Plasma Medicine 1 (2011); Xiaoqian, C. et al., “Synergistic effect of gold nanoparticles and cold plasma on glioblastoma cancer therapy,” Journal of Physics D: Applied Physics 47, 335402 (2014); Thiyagarajan, M., Waldbeser, L. & Whitmill, A., “THP-1 leukemia cancer treatment using a portable plasma device,” Studies in health technology and informatics 173, 515-517 (2011); and Barekzi, N. & Laroussi, M., “Dose-dependent killing of leukemia cells by low-temperature plasma,” Journal of Physics D: Applied Physics 45, 422002 (2012). In addition, the CAP also strongly resists tumor growth in mice. Several general conclusions about the anti-cancer mechanism of CAP have been acknowledged. First, the rise of intracellular ROS always occurs in cancer cells upon CAP treatment, which causes a noticeable damage on the antioxidant system and subsequently DNA double strands break (DSB) to a fatal degree. See, Zhao, S. et al., “Atmospheric pressure room temperature plasma jets facilitate oxidative and nitrative stress and lead to endoplasmic reticulum stress dependent apoptosis in HepG2 cells,” PloS one 8, e73665 (2013); Kaushik, N. K., Kaushik, N., Park, D. & Choi, E. H., “Altered Antioxidant System Stimulates Dielectric Barrier Discharge Plasma-Induced Cell Death for Solid Tumor Cell Treatment,” PloS one 9, e103349 (2014); and Koritzer, J. et al., “Restoration of sensitivity in chemo-resistant glioma cells by cold atmospheric plasma,” PloS one 8, e64498 (2013). Second, serious DNA damage and other effect of CAP on cancer cells result in the cell cycle arrest, apoptosis or necrosis with a dose-dependent pattern. Volotskova, O., Hawley, T. S., Stepp, M. A. & Keidar, M., “Targeting the cancer cell cycle by cold atmospheric plasma,” Scientific reports 2, 636 (2012); Kim, J. Y., Kim, S.-O., Wei, Y. & Li, J., “A flexible cold microplasma jet using biocompatible dielectric tubes for cancer therapy,” Applied Physics Letters 96, 203701 (2010); and Ma, R. N. et al., “An atmospheric-pressure cold plasma leads to apoptosis in Saccharomyces cerevisiae by accumulating intracellular reactive oxygen species and calcium,” Journal of Physics D: Applied Physics 46, 28540 (2013). Third, among diverse reactive species generated in CAP, H 2 O 2 and NO are proposed to be key molecules to kill cancer cells. See, Bekeschus, S. et al., “Hydrogen peroxide: A central player in physical plasma-induced oxidative stress in human blood cells,” Free Radical Research 48, 542-549 (2014). Fourth, untransformed normal cells always show stronger resistance to CAP than cancer cells do. Such killing preference on cancer cells is always accompanied with the distinct ROS levels and DSB among cancer cells and normal cells. Georgescu, N. & Lupu, A. R., “Tumoral and normal cells treatment with high-voltage pulsed cold atmospheric plasma jets,” Plasma Science, IEEE Transactions on 38, 1949-1955 (2010); Zucker, S. N. et al., “Preferential induction of apoptotic cell death in melanoma cells as compared with normal keratinocytes using a non-thermal plasma torch,” Cancer biology & therapy 13, 1299-1306 (2012); and Ja Kim, S., Min Joh, H. & Chung, T. H. “Production of intracellular reactive oxygen species and change of cell viability induced by atmospheric pressure plasma in normal and cancer cells,” Applied Physics Letters 103, 153705 (2013).
[0008] Conventionally, the CAP is directly used to irradiate cancer cells or tissue. Over past three years, the CAP irradiated media was also found to kill cancer cells as effectively as the direct CAP treatment did. Yan, D. et al., “Controlling plasma stimulated media in cancer treatment application,” Applied Physics Letters 105, 224101 (2014). In contrast to the direct CAP treatment, CAP stimulated (CAPS) media has advantages. The CAPs media can be stored in the refrigerator and maintain its anti-cancer capacity for at least 7 days. Adachi, T. et al., “Plasma-activated medium induces A549 cell injury via a spiral apoptotic cascade involving the mitochondrial-nuclear network,” Free radical biology & medicine 79 C, 28-44 (2014). Thus, the CAPs media might be a good fit for the condition where a CAP device is not available. Moreover the CAPs media can be injected into tissues and effectively prevent tumor growth. Utsumi, F. et al., “Effect of indirect nonequilibrium atmospheric pressure plasma on anti-proliferative activity against chronic chemo-resistant ovarian cancer cells in vitro and in vivo,” PloS one 8, e81576 (2013). These tissues may not be easily penetrated by the CAP jet, which only causes the cell death in the upper 3-5 cell layers of the CAP touched tissues. Partecke, L. I. et al., “Tissue tolerable plasma (TTP) induces apoptosis in pancreatic cancer cells in vitro and in vivo,” BMC cancer 12, 473 (2012). To date, the anti-tumor capacity of the CAPs media has been researched less than the direct CAP treatment. Therefore, basic principles to guide its application remain elusive.
SUMMARY OF THE INVENTION
[0009] In a preferred embodiment of the present invention, cold atmospheric plasma stimulated media (CAPs) is prepared and used to treat glioblastoma cells and breast cancer cells. Specifically, a method in accordance with a preferred embodiment of the present invention uses larger wells on a multi-well plate, smaller gaps between the plasma source and the media, and smaller media volume enabled us to obtain a stronger anti-cancer CAPs media composition without increasing the treatment time. Furthermore, cysteine was the main target of effective reactive species in the CAPs media. Glioblastoma cells were more resistant to the CAPs media than breast cancer cells. Glioblastoma cells consumed the effective reactive species faster than breast cancer cells did. In contrast to nitric oxide, hydrogen peroxide was more likely to be the effective reactive species.
[0010] In a preferred embodiment the present invention is a method for preparing cold atmospheric plasma stimulated cell culture media with a cold atmospheric plasma system having a delivery port out of which an inert gas flows. The inert gas may be, for example, helium. The method comprises the steps of placing a cell culture media in a first well, the first well having a bottom and having a diameter greater than 20 mm; wherein the cell culture media placed in the first well has a volume of 4 ml or less, treating the cell culture media in the first well with cold atmospheric plasma, wherein the treating is performed with a gap between the delivery port and the bottom of the first well is between 2.5 cm and 3.5 cm, and transferring a portion of the treated media to cultured cancer cells in a second well. In another preferred embodiment, the gap is 3 cm. In one preferred embodiment, the cold atmospheric plasma is applied to the cell culture media for 0.5 minutes to 2 minutes. In another preferred embodiment, the step of treating the cell culture media comprises applying cold atmospheric plasma to the cell culture media for 1.5 minutes or longer. The cell culture media may comprise Dulbecco's modified Eagle's medium (DMEM) or DMEM supplemented with fetal bovine serum and an antibiotic solution. In another preferred embodiment, the cell culture media placed in the first well has a volume of 2 ml or less.
[0011] In the present invention four factors have been found to be capable of optimizing the anti-cancer capacity of the CAPs media on glioblastoma cells (U87), breast cancer cells (MDA-MB-231 and MCF-7): (1) the treatment time; (2) the well size; (3) the gap between plasma source and liquid; and (4) the volume of media.
[0012] Glioblastoma is the most lethal form of brain cancer. Parsons, D. W. et al., “An integrated genomic analysis of human glioblastoma multiforme,” Science 321, 1807-1812 (2008). Due to its strong resistance to conventional therapy, the median survival time of patients is only 15 months. Eramo, A. et al., “Chemotherapy resistance of glioblastoma stem cells,” Cell Death & Differentiation 13, 1238-1241 (2006). CAP has shown promising anti-cancer capacity on glioblastoma cells in vitro and in vivo.
[0013] Breast cancer is the most common women malignancy in United States. Estrogen receptor-negative MDA-MB-231 cells and estrogen receptor-positive MCF-7 cells are highly invasive and poorly invasive breast cancer cells, respectively. The vulnerability of these three cell lines to the CAPs media was compared. In addition, we investigated which amino acids reacted most significantly with the effective reactive species by using the amino acids rich DMEM. It was determined that, compared with NO, H 2 O 2 was more likely to be main effective reactive species. Because the diffusion speed of H 2 O 2 across the cellular membrane might directly affect the intracellular ROS level, the consumption speeds of effective reactive species and H 2 O 2 by cancer cells were studied. Ultimately, the anti-cancer effect of H 2 O 2 rich DMEM was investigated to explore whether H 2 O 2 was the only effective reactive species.
[0014] Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a preferable embodiments and implementations. The present invention is also capable of other and different embodiments and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description and the accompanying drawings, in which:
[0016] FIGS. 1A and 1B are schematic diagrams of a device setup ( 1 A) and the general process flow ( 1 B) for making cold atmospheric plasma stimulated (CAPs) media.
[0017] FIGS. 2A-D illustrates the dose-dependent ROS/RNS accumulation in the CAPs solution. (a) Relative RNS concentration in 1 mL CAPs complete media. (b) Relative H 2 O 2 concentration in 1 mL CAPs complete media. (c) Relative MB concentration in 1 mL CAPs MB solution. (d) Relative MB concentration in 2 mL CAPs MB solution. Results are presented as the mean±s.d. of three repeated experiments performed in triplicate. Student's t-test was performed, and the significance compared with the first bar is indicated as *p<0.05, **p<0.01, ***p<0.005.
[0018] FIGS. 3A-D illustrate the well size-dependent ROS/RNS accumulation in the CAPs solution. (a) Relative RNS concentration in 1 mL of CAPs complete media. (b) Relative H 2 O 2 concentration in 1 mL of CAPs complete media. (c) Relative MB concentration in 1 mL of CAPs MB solution. (d) Relative MB concentration in 2 mL CAPs of MB solution. Results are presented as the mean±s.d. of three repeated experiments performed in triplicate. Student's t-test was performed, and the significance compared with the first bar is indicated as *p<0.05, **p<0.01, ***p<0.005.
[0019] FIGS. 4A-G illustrate the dose-dependent and well size-dependent anti-cancer capacity of the CAPs solution. The relative viability of U87 cells ( FIG. 4A ), MDA-MB-231 cells ( FIG. 4B ), and MCF-7 cells ( FIG. 4C ) cultured in 1 mL of CAPs media with different treatment time. The relative viability of U87 cells (2×104 cells/ml) ( FIG. 4D ), MDA-MB-231 cells (2×104 cells/ml) ( FIG. 4E ), MCF-7 cells (2×104 cells/ml) ( FIG. 4F ), and MCF-7 cells (4×104 cells/ml) ( FIG. 4G ) cultured in 1 mL of CAPs media from different multi-well plates. The treatment time for FIGS. 4D-4G were 1 min. Results are presented as the mean±s.d. of three repeated experiments performed in sextuplicate. Student's t-test was performed, and the significance compared with the first bar is indicated as *p<0.05, **p<0.01, ***p<0.005.
[0020] FIGS. 5A-5E illustrate the ROS/RNS accumulation in the CAPs media and the anti-cancer capacity of CAPs media are gap-dependent. FIG. 5A illustrates relative RNS concentration in 1 mL CAPs complete media versus the gap between the delivery port in the cold atmospheric plasma system and the bottom of the well during the treatment. FIG. 5B illustrates relative H 2 O 2 concentration in 1 mL of CAPs complete media. FIG. 5C illustrates the relative viability of U87 cells versus the gap. FIG. 5D illustrates the relative viability of MDA-MB-231 cells versus the gap. FIG. 5E illustrates the relative viability of MCF-7 cells versus the gap. For FIG. fC- 5 E the cells were cultured in 1 mL of CAPs complete media. The treatment time for all of FIGS. 5A-5E was 1 min. Results are presented as the mean±s.d. of three repeated experiments performed in triplicate ( FIG. 5A-5B ) or in sextuplicate (FIG. % c- 5 E). Student's t-test was performed, and the significance compared with the first bar is indicated as *p<0.05, **p<0.01, ***p<0.005.
[0021] FIG. 6A-E . The ROS/RNS accumulation in the CAPs media and the anti-cancer capacity of CAPs media are volume-dependent. FIG. 6A illustrates RNS concentration in the CAPs complete media relative to the volume of the media being treated. FIG. 6B illustrates the H 2 O 2 concentration in the CAPs complete media relative to the volume of the media being treated. FIGS. 6C-6E respectively illustrate viability of U87 cells ( FIG. 6C ), MDA-MB-231 cells ( FIG. 6D ), and MCF-7 cells ( FIG. 6E ) cultured in the CAPs complete media versus the volume of the media treated. The treatment time for all figures was 1 min. Results are presented as the mean±s.d. of three repeated experiments performed in triplicate (a,b) or in sextuplicate (c,d,e). Student's t-test was performed, and the significance compared with the first bar is indicated as *p<0.05, **p<0.01, ***p<0.005.
[0022] FIGS. 7A-C illustrate effectiveness of various amino acids in CAPs DMEM. Cysteine and tryptophan are the most reactive amino acids towards the effective species in the CAPs DMEM. FIG. 7A illustrates relative cell viability of U87 cells; FIG. 7B illustrates relative viability of MDA-MB-231 cells; and FIG. 7C illustrates relative viability of MCF-7 cells. All cells were cultured in the CAPs amino acids rich DMEM (2.4 mM). The treatment time for all figures was 1 min. Results are presented as the mean±s.d. of three repeated experiments performed in sextuplicate. Student's t-test was performed, and the significance compared with the bar of DMEM is indicated as *p<0.05, **p<0.01, ***p<0.005. Red arrows mark the amino acids which are significantly weaken the anti-cancer capacity of CAPs media for three cell lines.
[0023] FIGS. 8A-B . In contrast with NO, H 2 O 2 is more reactive with amino acids. The concentration of RNS ( FIG. 8A ) and H 2 O 2 ( FIG. 8B ) in the CAPs amino acids rich DMEM (2.4 mM). FIG. 8A is presented as the mean±s.d. of three repeated experiments performed in sextuplicate. FIG. 8B is presented as the mean±s.d. of two repeated experiments performed in sextuplicate. Student's t-test was performed, and the significance compared with the bar of DMEM is indicated as *p<0.05, **p<0.01, ***p<0.005. Red arrows mark the amino acids which are significantly weaken the anti-cancer capacity of CAPs media for three cell lines.
[0024] FIGS. 9A-B illustrates the consumption speed of effective species in the CAPs media by cancer cells. ( FIG. 9A ) A cell probe (MDA-MB-231 cells) was used to discriminate how fast the effective species in the CAPs media consumed by three cancer cell lines. The cell probe viability in this figure represents the ratio of the viability of cell probe (MDA-MB-231 cells) cultured in the residual CAPs media which has been used to culture U87 cells, MDA-MB-231 cells, and MCF-7 cells for a period of time to the viability of cell probe (MDA-MB-231 cells) cultured in the complete media without CAP treatment. ( FIG. 9B ) The H 2 O 2 concentration in the residual CAPs media which has been used to culture U87 cell, MDA-MB-231 cells, and MCF-7 cells for a period of time. Results are presented as the mean±s.d. of three repeated experiments performed in sextuplicate ( FIG. 9A ) or triplicate ( FIG. 9B ). Student's t-test was performed, and the significance compared with the first bar (consumption time of 0 hr) is indicated as *p<0.05, **p<0.01, ***p<0.005.
[0025] FIG. 10 . The anti-cancer capacity of the H 2 O 2 rich media on U87 cells, MDA-MB-231 cells, and MCF-7 cells. The real concentration measured by Fluorimetric Hydrogen Peroxide Assay Kit (Sigma-Aldrich) is shown in the parenthesis following the nominal concentration based on the calculation in preparation. The equivalent CAP treatment time (eqT) is shown in the bottom of figure. eqT was calculated based on the formula that eqT=(measured H 2 O 2 concentration in the H 2 O 2 rich media, mC)×(conversion coefficient, cC). Here, cC is 0.03. For example, eqT of 1.211=mC of 40.35 times cC of 0.03. To obtain cC, we first measured the H 2 O 2 concentration in the media which has been treated by CAP for 0.5, 1, 1.5, and 2 min. Then, the linear fitting between the measured H 2 O 2 concentration and the treatment time helped us to get cC. Results are presented as the mean±s.d. of three repeated experiments performed in sextuplicate. Student's t-test was performed, and the significance compared with the first bar (nominal concentration of 1 pt M) is indicated as *p<0.05, **p<0.01, ***p<0.005.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Preferred embodiments of the present invention are described with reference to the accompanying drawings. In a preferred embodiment of the present invention, the cold plasma jet generator uses helium as the carrying gas. Helium in cold atmospheric plasma previously was described in a study about the CAP effect on the cell surface integrins expression and the response of glioblastoma cells upon the CAP treatment. See, Shashurin, A. et al. Influence of Cold Plasma Atmospheric Jet on Surface Integrin Expression of Living Cells. Plasma Processes and Polymers 7, 294-300 (2010) and Cheng, X. et al. The Effect of Tuning Cold Plasma Composition on Glioblastoma Cell Viability. PloS one 9, e98652 (2014). As shown in FIG. 1A , the CAP system 100 has a high voltage power supply 110 , a gas source 120 , tube(s) 130 to provide for gas flowing from the gas source 130 , a Teflon accessory 140 , a central electrode 150 , a ring electrode 160 , and a quartz tube 170 . CAP was generated between central electrode 150 and ring electrode 160 and the plasma jet 180 flowed out of the quartz tube 170 . A flow meter 122 , for example, may be used to control the helium flow at a rate. In other embodiments, the gas and electrical controls may be combined into a single unit. A helium flow rate of 4.7 L/min was used in the examples. The input voltage of DC power was 11.5 V. The output voltage was 3.16 kV. The power supply was about 5 W.
[0027] As a preliminary step, cancer cells are cultured overnight. For example, the cancer cells may be cultured in an incubator under the standard conditions (a 37° C., 5% (v/v) CO 2 and humidified environment) for 72 hours. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), a colorimetric assay (Sigma-Aldrich) was harnessed to qualify the cell viability. The initial media which had been used to culture cancer cells overnight may be discarded prior to treatment with CAPs media. In the Examples below, Human U87 cells and Human MDA-MB-231 cells and MCF-7 cells were cultured for 24 hours in a complete media composed of Dulbecco's modified Eagle's medium (DMEM) (Life Technologies) supplemented with 10% (v/v) fetal bovine serum (FBS) (Atlantic Biologicals) and 1% (v/v) antibiotic (penicillin and streptomycin) solution (Life Technologies) under the standard cell culture conditions (a humidified, 37° C., 5% CO 2 environment).
[0028] A general process of treating the media in accordance with a preferred embodiment of the present invention is illustrated in FIG. 1B . A plasma jet 180 vertically irradiates the media 300 in each well 200 in a 6-well plate or tray 410 . After treatment, the CAPs media 300 a is transferred to cultured cancer cells 500 , which had been seeded in a 96-well plate or tray 420 .
Example 1
[0029] The Dose-Dependent NO, H 2 O 2 Accumulation in the CAPs Media.
[0030] First, 1 mL of complete media in a well on 6-well plate (Falcon) was treated by CAP for 0.5 min, 1 min, 1.5 min, and 2 min, respectively. The gap between the bottom of the quartz tube and the bottom of plate was 3 cm. 50 μL of CAPs complete media was immediately transferred to a well on a black 96-well clear bottom plate (Falcon) in triplicate. As the control, 50 μL of untreated complete media was also transferred to a well on the same plate in triplicate. Next, according to the standard protocols provided by Promega and Sigma-Aldrich, the NO and H 2 O 2 concentration in the CAPs media were measured, respectively. The absorbance at 540 nm and the fluorescence at 540/590 nm were read using a H1 microplate reader (Hybrid Technology).
[0031] The Liquid Surface-Dependent NO, H 2 O 2 Accumulation in the CAPs Media.
[0032] First, 1 mL of complete media in a well on 48-well, 24-well, 12-well, and 6-well plate (Falcon) were respectively treated by CAP for 1 min. The gap between the outlet of the quartz tube and the bottom of plate was 3 cm. Then, 50 μL of CAPs media from different multi-well plates were immediately transferred to a well on the black 96-well clear bottom plate in triplicate. For the control, 50 μL of untreated CAPs media was also transferred to a well on the same plate in triplicate. Ultimately, we measured the NO/H 2 O 2 concentration in the CAPs media.
[0033] The Dose-Dependent OH Accumulation in the MB Solution.
[0034] The MB solution was prepared by dissolving MB powder into deionized water. Then, 1 mL of 0.01 g/L MB solution in a well on 6-well plate was treated by CAP for 0.5 min, 1 min, 1.5 min, and 2 min. The gap between the outlet of the quartz tube and the bottom of plate was 3 cm. 100 μL of CAPs MB solution was immediately transferred to a well on the black 96-well clear bottom plate in triplicate. As the control, 100 μL of untreated MB solution was also transferred to a well on the same plate in triplicate. Ultimately, we measured the absorbance at 664 nm using a H1 microplate reader (Hybrid Technology).
[0035] The Liquid Surface-Dependent OH Accumulation in the MB Solution.
[0036] First, 1 mL of 0.01 g/L MB solution in a well on 48-well, 24-well, 12-well, and 6-well plate were respectively treated by CAP for 1 min. The gap between the outlet of quartz tube and the bottom of plate was 3 cm. Next, 100 μL of CAPs MB solution was transferred to a well on the black 96-well clear bottom plate in triplicate. 100 μL of untreated MB solution was also transferred to a well on the same plate in triplicate as the control. Ultimately, we measured the absorbance at 664 nm using a H1 microplate reader (Hybrid Technology).
[0037] The Dose-Dependent Anti-Cancer Capacity of CAPs Media.
[0038] For each cell line, the protocol was identical. Here, we used U87 cells as an example. First, U87 cells were seeded in 96-well plate with three confluencies (2×10 4 cells/ml, 4×10 4 cells/ml, and 8×10 4 cells/ml) and cultured in an incubator for 24 hours under standard conditions. Next, 1 mL of complete media in a well on 6-well plate was respectively treated by CAP for 0.5 min, 1 min, 1.5 min, and 2 min. The gap between the outlet of the quartz tube and the bottom of plate was 3 cm. 100 μL of CAPs media were immediately transferred to culture U87 cells in a well on the 96-well plate in sextuplicate. 100 μL of untreated complete media was also transferred to culture U87 cells in a well on the same plate in sextuplicate as the control. Before this step, the media that was used to culture U87 cells overnight was discarded. After that, U87 cells were cultured in the CAPs media for 72 hours. Ultimately, according to the standard method, the viability of U87 cells were qualified by MTT test and were read by a H1 microplate reader (Hybrid Technology) at the absorbance of 570 nm.
[0039] Reactive species accumulate in the CAPs media with a dose-dependent and liquid surface-dependent pattern. Among dozens of species, NO in RNS and H 2 O 2 in ROS are thought to play key roles in killing cancer cells. See, Ahn, H. J. et al. Atmospheric-pressure plasma jet induces apoptosis involving mitochondria via generation of free radicals. PloS one 6, e28154 (2011) and Ahn, H. J. et al. Targeting cancer cells with reactive oxygen and nitrogen species generated by atmospheric-pressure air plasma. PloS one 9, e86173 (2014). In addition, hydroxyl free radicals (.OH) in CAP are also proposed to kill cancer cells. Ninomiya, K. et al. Evaluation of extra- and intracellular OH radical generation, cancer cell injury, and apoptosis induced by a non-thermal atmospheric-pressure plasma jet. Journal of Physics D: Applied Physics 46, 425401 (2013). To date, most of these conclusions are based on the research for the direct CAP treatment on cancer cells. The understanding on the RNS and ROS accumulation in the CAPs media is far from clear. In connection with the present invention, generation of NO and H 2 O 2 in the CAPs complete media (90% DMEM+10% FBS) was studied via Griess Reagent System (Promega) and Fluorimetric Hydrogen Peroxide Assay Kit (Sigma-Aldrich), respectively.
[0040] Next, we harnessed methylene blue (Fisher) to qualify the generation of OH. In contrast to terephthalic acid, and more convenient probe, MB strongly reacts with OH in the aqueous solution and changes its color from blue into colorless, which can be detected by spectrophotometer at 664 nm. See, Riesz, P., Berdahl, D. & Christman, C. Free radical generation by ultrasound in aqueous and nonaqueous solutions. Environmental Health Perspectives 64, 233 (1985) and Yan, D., Wang, J. & Liu, F. Inhibition of the ultrasonic microjet-pits on the carbon steel in the particles-water mixtures. AIP Advances 5, 077159 (2015). The atmospheric plasma jet is a proven MB decomposition tool. Takemura, Y., Yamaguchi, N. & Hara, T. Decomposition of Methylene Blue by using an Atmospheric Plasma Jet with Ar, N2, O2, or Air. Japanese Journal of Applied Physics 52, 056102 (2013). We proved that MB was just sensitive to the species with a short half-life ( FIG. S1 ). Because MB is strongly absorbed by the proteins in the complete media, we investigated the generation of OH in the CAPs deionized water in this study.
[0041] Reactive species accumulate in the CAPs media with different patterns. To better illustrate these patterns, all data in FIGS. 2A-2D have been normalized to be the relative values via dividing the data from experimental group by the data from corresponding control group. RNS ( FIG. 2A ) and H 2 O 2 ( FIG. 2B ) in the CAPs media both increase as the treatment time increases. Because MB will be consumed after the reaction with OH, corresponding relative absorbance of the CAPs MB solution should be less than 1. However, as shown in FIG. 2C , noticeable OH generation was not observed even the treatment time was extended to 2 min. We performed the same experiment in the MB solution with a larger volume (2 mL) and found that the generation of OH was proportional to the plasma treatment time again ( FIG. 2D ). This volume-dependent pattern may be due to the interaction between plasma jet and solution. During the CAP treatment, the liquid below the plasma jet would be extruded, pushing the solution to the perimeter of well ( FIG. 2A ). When the volume of liquid was just 1 mL, the plasma jet could not touch liquid due to the exposure of the bottom of well. When the volume of liquid was up to 2 mL, the extrusion of liquid would be weaker and enabled the plasma jet to touch the liquid layer. However, even when the plasma jet does not touch the liquid, the reactive species are still able to dissolve into the liquid. Yonemori et al. observed that when an atmospheric-pressure plasma jet touched a glass surface, it flowed radically over the glass surface and formed a large area containing reactive species on the glass surface. Thus, the reactive species in the plasma jet should affect an area of liquid that is significantly larger than the diameter of the jet. The half-life of OH is only a few microseconds, however, which eliminates the possibility that OH diffuses over the liquid surface ( FIG. 2A ). Southorn, P. A. & Powis, G. Free Radicals in Medicine. I. Chemical Nature and Biologic Reactions. Mayo Clinic Proceedings 63, 381-389 (1988). In contrast, H 2 O 2 and NO with much longer half-life may enter the media by the diffusion over the whole surface of liquid. We denote that H 2 O 2 /NO area and OH area to represent the area mainly affected by H 2 O 2 /NO and OH on the liquid surface covered by plasma flow, respectively ( FIG. 2A ). Together, when the volume of media is relative small, OH will not be a main factor to directly affect the anti-tumor capacity of the CAPs media. OH may react with OH to form H 2 O 2 and affects the anti-tumor capacity indirectly.
[0042] If H 2 O 2 /NO area and OH area do exist as we depicted in FIG. 2 , it is reasonable to deduce that the surface of media irradiated by the plasma may affect the accumulation of H 2 O 2 /NO but not OH in the CAPs media. We proved this deduction by measuring the production of H 2 O 2 /NO and OH in the CAPs media and CAPs MB solution in distinct multi-well plates, respectively. The well diameters on 48-well, 24-well, 12-well, and 6-well plate were 10.2 mm, 15.4 mm, 21.4 mm, and 35.0 mm, respectively. We found that the H 2 O 2 /NO concentration in the CAPs media varied significantly with the well size on the plate. The larger diameter of well, the more H 2 O 2 /NO accumulated in the CAPs media ( FIGS. 3A-3B ). By contrast, the OH generation in the CAPs MB solution doesn't significantly vary with the well size ( FIG. 3C ), even when the volume of MB solution is up to 2 mL ( FIG. 3D ). The OH generation in the CAPs MB solution from a 6-well plate is noticeably lower than that from other plates ( FIG. 3C ).
[0043] A schematic illustration in FIG. 2B depicts the underlying mechanism of the well size-effect on the reactive species accumulation. A smaller well creates a smaller H 2 O 2 /NO area on the media surface. More H 2 O 2 /NO will diffuse into the CAPs media when the well size becomes larger. Additionally, the thickness of media in the well increases as the well size decreases. The calculated liquid thickness of 1 mL media in 48-well, 24-well, 12-well, 6-well plate are 12.2 mm, 5.4 mm, 2.8 mm, and 1.0 mm, respectively ( FIG. 2B ). Thus, the extrusion of media due to the plasma jet pressure will be weakened as the diameter of well decreases. When the volume of MB solution is just 1 mL, compared with the MB solution in 6-well plate, the MB solution in other multi-well plates is more likely to contact the OH in the CAP. Thus, more MB is consumed in the CAPs MB solution from 48-well, 24-well, and 12-well plate than that from 6-well plate ( FIG. 3C ). Even when the volume of MB solution is 2 mL, OH is only able to affect a small area on the media directly touched by the CAP jet, so the OH generation in the CAPs MB solution changes little when the well size is noticeably altered. In short, the distinct half-life among H 2 O 2 /NO and OH underlies the different well size-effect of reactive species observed in this study.
Example 2
[0044] The Well Size-Dependent Anti-Cancer Capacity of CAPs Media.
[0045] The protocols for three cell lines were identical. Here, we used U87 cells as an example. First, U87 cells were seeded in a 96-well plate with a confluence of 2×10 4 cells/ml and were cultured in an incubator for 24 hours under standard conditions. Next, 1 mL of complete media in a well on 48-well, 24-well, 12-well, and 6-well plate were treated with CAP for 1 min. The gap between the outlet of the quartz tube and the bottom of plate was 3 cm. Then, 100 μL of CAPs media were immediately transferred to culture U87 cells in a well on the 96-well plate in sextuplicate. As the control, 100 μL of untreated media was also transferred to culture U87 cells on the same plate in sextuplicate. Before this step, the media that had been used to culture U87 cells overnight was discarded. After that, U87 cells were cultured in the CAPs media for 72 hour. Ultimately, the cell viability was measured.
[0046] The Anti-Tumor Capacity of the CAPs Media is Dose-Dependent and Well Size-Dependent.
[0047] We further investigated the anti-tumor capacity of CAPs media on glioblastoma cells (U87), breast cancer cells (MDA-MB-231 and MCF-7) with distinct cell confluences. It was found that the anti-tumor capacity of the CAPs media increases as the treatment time (dose) increases and decreases as the cell seeding confluence decreases ( FIGS. 4A-4C ). Thus, it is the dose of CAP treatment exerting on a unit cell, rather than the whole CAP treatment dose that determines the fate of cancer cells. In addition, MDA-MB-231 cells and MCF-7 cells are more vulnerable to the CAPs media than U87 cells. The response of MDA-MB-231 cells and MCF-7 cells to the CAPs media is similar, though MCF-7 cells are a little easier to be killed.
[0048] We further investigated effect of well size on the anti-tumor capacity of the CAPs media on the same three cancer cell lines. We found that the anti-tumor capacity of the CAPs media decreased as the size of the wells decreased ( FIG. 4D-4G ). For U87 cells, the residual viability of cells cultured in the CAPs media from a 6-well plate is about ⅓ of the viability of cells cultured in the CAPs media from a 48-well plate ( FIG. 4D ). In other words, at least ⅔ of the anti-cancer ability of the CAPs media is wasted in the 48-well plate. A similar trend is also observed on MDA-MB-231 cells ( FIG. 4E ). However, the well size-effect on MCF-7 cells only appears when the seeding confluence is as high as 4×10 4 cells/ml ( FIG. 4G ), which may be due to the fact that even the CAPs media from a 48-well plate is adequate to kill almost all MCF-7 cells with a seeding confluence as low as 2×10 4 cells/ml ( FIG. 4F ). Accordingly, the 96-well plate should waste more reactive species. The dose-dependent and the well size-dependent anti-cancer features of the CAPs media is consisted with the dose-dependent and liquid surface-dependent reactive species accumulation.
Example 3
[0049] The Gap-Dependent NO/H 2 O 2 Accumulation in the CAPs Media.
[0050] First, when the gap between the outlet of the quartz tube and the bottom of the plate varied from 2 cm to 4 cm, 1 mL of complete media in a well on well plate was treated by CAP for 1 min. Then, 50 μL of CAPs media was immediately transferred to a well on the black 96-well clear bottom plate in triplicate. 50 μL of untreated complete media was also transferred to a well on the same plate in triplicate as the control. Ultimately, we measured the NO/H 2 O 2 concentration in the CAPs media.
[0051] The Gap-Dependent. OH Accumulation in the MB Solution.
[0052] First, when the gap between the outlet of the quartz tube and the bottom of the plate varied from 2 cm to 4 cm, 1 mL of 0.01 g/L MB solution in a well on 6-well plate was treated by CAP for 1 min. Next, 100 μL of CAPs MB solution was transferred to a well on the black 96-well clear bottom plate in triplicate. 100 μL of untreated 0.01 g/L MB solution was also transferred to the same plate in triplicate for the control. We measured the absorbance at 664 nm using a H1 microplate reader (Hybrid Technology).
[0053] The Gap-Dependent Anti-Cancer Capacity of the CAPs Media.
[0054] The protocol for the three cell lines was identical. Here, we used U87 cells as an example. First, U87 cells were seeded in 96-well plate with a confluence of 2×10 4 cells/ml and were cultured in incubator for 24 hours under standard conditions. Next, when the gap between the outlet of the quartz tube and the bottom of plate varied from 2 cm to 4 cm, 1 mL of complete media in a well on a 6-well plate was treated by CAP for 1 min. Then, 100 μL of CAPs media were immediately transferred to culture U87 cells in a well on 96-well plate in sextuplicate. 100 μL of the untreated complete media was also transferred to culture U87 cells in a well on 96-well plate in sextuplicate as the control. Before this step, the media that was used to culture U87 cells overnight was discarded. U87 cells were then cultured in the CAPs media for 72 hours. Ultimately, the cell viability was measured.
[0055] The Anti-Tumor Capacity of the CAPs Media Varies with the Gap Between Plasma Source and Media.
[0056] For the media in the well with identical volume, when the well size decreases, the height of the media in the well increases. Thus, the well size-dependent effect may be due to the altered size of the gap between the surface of the media and the plasma source. We investigated the generation of NO and H 2 O 2 in CAPs media by altering the gap between the bottom of plate and the nozzle of quartz tube. We found that the NO and H 2 O 2 in the CAPs media shown a distinct response to a change in gap. As the gap increases from 2 cm to 4 cm, the concentration of NO in the CAPs media shows a parabolic response. It reaches a peak at the gap of 3 cm and then decreases as the gap is increased to 4 cm ( FIG. 5 a ). The distribution of NO along the axial direction of the atmospheric pressure plasma jet has been measured by laser induced fluorescence and showed similar trend as we observed. See, van Gessel, A. F. H. et al. Temperature and NO density measurements by LIF and OES on an atmospheric pressure plasma jet. Journal of Physics D: Applied Physics 46, 095201, (2013). In contrast, the concentration of H 2 O 2 shows a stepwise change upon the gap increase. The concentration of H 2 O 2 in the CAPs media remains fairly constant over the gap of 2 cm to 3 cm. When the gap increased from 3 cm to 4 cm, the concentration of H 2 O 2 in the CAPs media decreased about 26% ( FIG. 5B ). Next, we investigated the viability change of three cancer cell lines upon the gap change. As shown in FIGS. 5C-5E , the anti-tumor capacity of the CAPs media dose not noticeably change until the gap increases to 3.5 cm or 4 cm. The gap-effect on the anti-cancer capacity is consistent with the gap-effect on the generation of H 2 O 2 but significantly differs from the gap-effect on the generation of NO. It indicates that H 2 O 2 rather than NO may dominate the death of cancer cells. Ultimately, FIG. 5 proves that the well size-effect on the CAPs media is not due the gap-effect. Because the smaller gap only tends to generate more reactive species, the actual well size—
Example 4
[0057] The Volume-Dependent NO/H 2 O 2 Accumulation in the CAPs Media.
[0058] First, 1 mL, 2 mL, 3 mL, and 4 mL of complete media in a well on 6-well plate were treated by CAP for 1 min. The gap between the outlet of the quartz tube and the bottom of the plate was 3 cm. 50 μL of CAPs complete media was immediately transferred to a well on the black 96-well clear bottom plate in triplicate. 50 μL of the untreated complete media was also transferred to a well on the same plate in triplicate for the control. Ultimately, we measured the NO/H 2 O 2 concentration in the CAPs media.
[0059] The Volume-Dependent OH Accumulation in the MB Solution.
[0060] 1 mL, 2 mL, 3 mL, and 4 mL of 0.01 g/L MB solution in a well on 6-well plate were treated by CAP for 1 min. The gap between the outlet of the quartz tube and the bottom of the plate was 3 cm. 100 μL of CAPs MB solution was transferred to a well on a black 96-well clear bottom plate in triplicate. 100 μL of untreated 0.01 g/L MB solution was also transferred to a well on the same plate in triplicate for the control. Ultimately, we measured the absorbance at 664 nm using a H1 microplate reader.
[0061] The Volume-Dependent Anti-Cancer Capacity of the CAPs Media.
[0062] The protocols for three cell lines were identical. Here, U87 cells were used as an example. First, U87 cells were seeded in 96-well plate with a confluence of 2×10 4 cells/ml and were cultured in incubator for about 24 hours under standard conditions. Second, 1 mL, 2 mL, 3 mL, and 4 mL of complete media in a well on 6-well plate were treated by CAP for 1 min. The gap between the outlet of the quartz tube and the bottom of the plate was 3 cm. Then, 100 μL of CAPs complete media was immediately transferred to culture U87 cells in a well on a 96-well plate in sextuplicate. 100 μL of the untreated complete media was also used to culture U87 cells in a well on same plate in sextuplicate for the control. Before this step, the media which has been used to culture U87 cells overnight was discarded. After that, U87 cells were cultured in the CAPs media for 72 hours. Ultimately, the cell viability was measured.
[0063] The Anti-Cancer Capacity is Volume-Dependent.
[0064] The strong anti-cancer capacity of the CAPs media always accompanies a high concentration of species in the media. Because the increase of media depth means the increase of media volume in the same container, the protecting role of media may just due to the dilution of reactive species in the media. We investigated the volume-effect on the anti-cancer capacity of the CAPs media. It was found that both the concentrations of H 2 O 2 ( FIG. 6A ) and NO ( FIG. 6B ) decreased as the volume of media increased. Furthermore, the killing capacities of the CAPs media on three cancer cell lines significantly decreased as the volume of media increased ( FIGS. 6C-6E ). In short, the protecting role of media is due to the dilution-effect of the reactive species. According to this principle, the optimized anti-cancer capacity of CAP treatment, direct or indirect, can be achieved when cells are surrounded by a few media.
Example 5
[0065] The Anti-Cancer Capacity of CAPs Amino Acids Rich DMEM.
[0066] The protocol for three cell lines was identical. Here, U87 cells were used as an example. First, U87 cells were seeded in 96-well plate with a confluence of 2×10 4 cells/ml and were cultured in an incubator for 24 hours under standard conditions. Second, we respectively prepared 2.4 mM specific amino acids rich DMEM by dissolving specific quantities of amino acids powers (Sigma-Aldrich) in DMEM (1% ABS). Because some amino acid rich DMEM would be gradually oxidized by the air during long storage even in the refrigerator, all prepared amino acid rich DMEM were discarded and renewed every two weeks. Next, all 20 specific amino acid rich DMEM and normal DMEM were treated by CAP for 1 min in a well on 6-well plate. The volume of solution in each well was 1 mL. The gap between the outlet of the quartz tube and the bottom of the plate was 3 cm. 100 μL of the CAPs amino acids rich DMEM and the CAPs normal DMEM were transferred to culture U87 cells in a well on 96-well plate in sextuplicate. As the control, 100 μL of the untreated amino acid rich DMEM and normal DMEM were also used to culture U87 cells in a well on 96-well plate in sextuplicate. Before this step, the media which has been used to culture U87 cells overnight was discarded. After that, U87 cells were then cultured in the CAPs media for 72 hours. Ultimately, the cell viability was measured.
[0067] Measurement of NO/H 2 O 2 in the CAPs Amino Acids Rich DMEM.
[0068] First, all 20 specific amino acids rich DMEM and normal DMEM were treated by CAP for 1 min in a well on 6-well plate. The volume of solution in each well was 1 mL. The gap between the outlet of the quartz tube and the bottom of the plate was 3 cm. 50 μL of the CAPs amino acid rich DMEM and the CAPs normal DMEM were immediately transferred to a well on the black 96-well clear bottom plate in triplicate. As the control, 50 μL of the untreated amino acid rich DMEM and normal DMEM were also transferred to a well on the same plate in triplicate. Ultimately, we measured the NO/H 2 O 2 concentration in the CAPs media.
[0069] Cysteine and Tryptophan are the Main Targets of Effective Species in the CAPs Media.
[0070] Here, we denote effective species to represent the effective reactive species which kill cancer cells. Understanding the chemical essence of the reaction between the effective species and the intracellular molecules is a prerequisite to understanding the mechanism underlying the anti-cancer capacity of CAP treatment. However, to study the intracellular reaction between RNS/ROS with the thousands of intracellular molecules directly is too challenging to be performed. We focused on revealing which amino acids significantly reacted with the effective species. The interaction between CAP and the amino acid solution have been studied via mass spectra. It was found that the sulfur-containing and aromatic amino acids in the aqueous solution were preferentially consumed in the CAP treatment. See, Takai, E. et al., “Chemical modification of amino acids by atmospheric-pressure cold plasma in aqueous solution,” Journal of Physics D: Applied Physics 47, 285403 (2014). Methionine, cysteine, tryptophan, phenylalanine, and tyrosine were the five most Consumed reactive amino acids upon the CAP treatment. However, some amino acids may be consumed by the species which do not kill cancer cells. The revealed reaction types between amino acids and plasma have not answered the question of which amino acids tend to react with the effective species.
[0071] We harnessed a novel strategy to reveal the reaction strength among effective species and specific amino acids. We used cancer cells as a cell probe to investigate whether the effective species in the CAPs media would be consumed by particular amino acids via comparing the anti-cancer capacity of a specific 2.4 mM CAPs amino acids rich DMEM with the corresponding untreated amino acids rich DMEM. Each amino acids rich DMEM was prepared by dissolving specific amino acids powers in DMEM.
[0072] Among 20 amino acids, cysteine and tryptophan showed the strongest reactivity towards the effective species in CAPs media. In contrast to DMEM, the cysteine rich DMEM consumes most effective species and almost completely eliminates the anti-tumor capacity of the CAPs DMEM on U87 cells ( FIG. 7 a ), MDA-MB-231 cells ( FIG. 7B ), and MCF-7 cells ( FIG. 7C ). Tryptophan has a similar but weaker capacity to consume effective species. A control group was also analyzed for each amino acid tested, because if a specific amino acid rich DMEM is toxic to cancer cells, the corresponding control group has a very low cell viability, which makes the relative cell viability in FIGS. 7A-C appear very large. As a result, we may get a delusion that a toxic amino acid consumes most effective species. In this study, for U87 cells and MCF-7 cells, tryptophan shows a strong resistance to growth of cancer cells ( FIGS. 4A-4C ). The mechanism underlying this toxicity is unclear. We also found that the tryptophan-rich DMEM did not resist the growth of MDA-MB-231 cells ( FIG. 4B ). Thus, the weak anti-tumor capacity of the CAPs tryptophan rich DMEM on MDA-MB-231 cells conclusively demonstrates that tryptophan is the second most sensitive amino acid to the effective species. In addition, the CAP treated DMEM tends to cause the most cell death among most CAPs amino acid rich DMEM. Thus, the effective species in CAP reacts with wide range of amino acids. Other than cysteine and tryptophan, arginine, lysine, asparagine, and glutamine also react significantly with the effective species in the CAPs media. Thus, they should also be the hot targets of effective species.
[0073] Furthermore, we studied the generation of H 2 O 2 and NO in the CAPs amino acid rich DMEM, which will reveal the species reacting strongly with specific amino acids. In contrast to NO, H 2 O 2 is more likely to be the effective species, because no significant difference of NO generation exists between different CAPs amino acids rich DMEM ( FIG. 8A ), while H 2 O 2 in the CAP simulated amino acid DMEM varied specifically with the amino acids in DMEM. Most of the hot targeted amino acids of effective species are also capable of consuming H 2 O 2 significantly in the CAPs DMEM (B). There are 15 amino acids that consume the H 2 O 2 generated in the CAPs DMEM, which is consistent with the conclusion made above that many amino acids react with the effective species in the CAP treated DMEM. Among them, cysteine rich DMEM consumes almost all H 2 O 2 . Despite tryptophan is the second most sensitive amino acids to H 2 O 2 , it just consumes about 23% of H 2 O 2 as cysteine does.
Example 6
[0074] Cancer Cells Consume the Reactive Species with a Cell Line-Dependent Pattern.
[0075] Due to the obscure essence of the effective species in the CAP, the consumption speed of the effective species by cancer cells has not been reported. Briefly, in this study, we harnessed one cancer cell line (MDA-MB-231) as the cell probe to investigate how much the effective species were left in the CAPs media which had been used to culture three cancer cell lines for a period of time ( FIG. 5 ). We denoted such CAPs media and such time as residual media and consumption time, respectively. The viability of cell probes (MDA-MB-231) was inversely proportional to the concentration of residual effective species in the residual media. The detailed protocols were illustrated in FIG. 5 . It has been found that the effective species in the residual media are gradually consumed by all three cell lines, which causes the viability of cell probe (MDA-MB-231 cells) cultured in residual media to increase as the consumption time increases ( FIG. 9A ). In addition, the cell probe (MDA-MB-231 cells) cultured in the residual media which has been used to culture U87 cells obtains higher cell viability than the cell probe cultured in the residual media which has been used to culture MDA-MB-231 cells and MCF-7 cells ( FIG. 9A ). In other words, U87 cells consume the effective species significantly faster than MDA-MB-231 cells and MCF-7 cells. For U87 cells, the residual CAPs media almost completely lose its anti-cancer capacity 3 hours after treatment. In contrast, for MDA-MB-231 cells and MCF-7 cells, the CAPs media still maintain significant anti-cancer capacity 3 hours after treatment. MDA-MB-231 cells and MCF-7 cells consumes the effective species similarly.
[0076] Because H 2 O 2 was regarded as the main effective species in the CAPs media, we further investigated the decay speed of H 2 O 2 in the residual media by measuring the evolution of H 2 O 2 in the CAPs media which had been used to culture three cell lines. We found that the H 2 O 2 in the residual media which had been used to culture U87 cells decayed noticeably faster than the cells in the residual media which had been used to culture MDA-MB-231 cells and MCF-7 cells ( FIG. 9B ). Thus, U87 cells are capable of consuming H 2 O 2 faster than MDA-MB-231 cells and MCF-7 cells.
Example 7
[0077] Measurement of the Consumption Speed of H 2 O 2 by Cancer Cells.
[0078] The protocol for the three cell lines is identical. Here, we used U87 cells as an example. First, U87 cells were seeded in 96-well plate with a confluence of 1×10 4 cells/ml and cultured in the incubator for 6 hours under the standard conditions. Then, 1 mL of complete media was treated by CAP in 6-well plate for 1 min. After that, 120 μL of the CAPs media was transferred to culture U87 cells on a 96-well plate. Since then, until the third hour, 50 μL of the residual media that was used to culture U87 cells was transferred to a well on the black 96-well clear bottom plate in triplicate. As the control, 100 μL of new complete media was also transferred to a well on the same plate in triplicate. Ultimately, we measured the H 2 O 2 concentration in the CAPs media.
[0079] The anti-cancer effect of H 2 O 2 rich media. The protocol for the three cell lines was identical. Here, U87 cells were used as an example. First, U87 cells were seeded in 96-well plate with a confluence of 2×10 4 cells/ml and were cultured in an incubator for 24 hours under standard conditions. Then, 1 μM, 5 μM, 10 μM, 20 μM, 25 μM, 50 μM, and 100 μM H 2 O 2 rich media was prepared by mixing 30 wt % H 2 O 2 solution (Sigma-Aldrich) with the complete media. 100 μL of these H 2 O 2 rich media was transferred to culture U87 cells in a well on 96-well plate in sextuplicate. 100 μL of normal complete media was also used to culture U87 cells in a well of the same plate in sextuplicate for the control. Before this step, the media which was used to culture U87 cells overnight was discarded. After that, U87 cells were then cultured in the incubator for 72 hours. Ultimately, the cell viability was measured.
[0080] H 2 O 2 Alone does not Equal to the CAPs Media.
[0081] To investigate whether H 2 O 2 was the sole factor in causing the death of cancer cells, we studied the response of three cancer cell lines to the H 2 O 2 rich media. The H 2 O 2 rich media was prepared by adding 30 wt % H 2 O 2 solution (Sigma-Aldrich) into the complete media. Because H 2 O 2 reacted with proteins in the complete media, the real concentration measured by Fluorimetric Hydrogen Peroxide Assay Kit (Sigma-Aldrich) was much less than the nominal concentration based on calculation in preparation. As shown in FIG. 10 , the growth of three cell lines presents a similar concentration (dose)-dependent response to the H 2 O 2 rich media. The growth of three cell lines will not be drastically suppressed until the concentration of H 2 O 2 is adequately large. It is not surprising, because high dose of H 2 O 2 produces cell death. See, Lopez-Lazaro, M. Dual role of hydrogen peroxide in cancer: possible relevance to cancer chemoprevention and therapy. Cancer letters 252, 1-8 (2007)
[0082] However, the responses of three cancer cells to H 2 O 2 are quite different. Generally, U87 cells and MCF-7 cells show stronger resistance to H 2 O 2 than MDA-MB-231 cells. U87 cells and MCF-7 cells share a similar response to H 2 O 2 except when the nominal concentration is between 20 to 50 μM. Clearly, the selective anti-tumor capacity of H 2 O 2 on three cells lines are distinct from that of the CAPs media on these cell lines ( FIG. 4 and FIG. 6 ). U87 cells are more resistant to the CAPs media than both MCF-7 cells and MDA-MB-231 cells. MDA-MB-231 cells are a slightly more Resistant to the CAPs media than MCF-7 cells. These differences demonstrate that H 2 O 2 is not the only reactive specie to cause the death of cancer cells. Some other species also play necessary role. Cysteine may react with not only H 2 O 2 but also other effective species in the CAPs media.
Discussion of Examples
[0083] So far, the anti-tumor capacity of CAP treatment has been regulated by controlling the treatment time, the gas sources composition, the gas flow rate, and the supply voltages. Gold nanoparticles and some small molecules such as osmolytes and 2-deoxy-d-glucose were also used to obtain a synergistic anti-cancer effect. In the present invention, we demonstrated several methods to obtain stronger anti-cancer capacity of the CAPs media. Specifically, the CAP treatment should be performed in a container with a large diameter. In addition, the gap between the plasma source and the media should be adequately small. To obtain high reactive species concentration, the volume of media should be relative small. Because these principles are fit for all cell lines involved in this study, they may be universal for other cancer cells.
[0084] Because 20 amino acids are the building blocks of all proteins, cysteine, the most reactive amino acid determined by cell probes, should also be the main targeted amino acid residue on the intracellular proteins or other small molecules. Intracellular ROS levels and redox balance are tightly regulated by multiple antioxidant defense systems, including small antioxidant molecules such as glutathione, NAD(P)H and ROS-scavenging enzymes such as catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, thioredoxin, thioredoxin reductase, and peroxiredoxin. Redox status of thiol group on the cysteine residue directly determines the function of glutathione peroxidase, thioredoxin, thioredoxin reductase, and peroxiredoxin. When thiold group on the cysteine residue was oxidized, corresponding normal function of some anti-oxidant enzymes or small molecules will be completely lost. Here, we take glutathione, the most abundant small molecular thiol inside mammalian cells, as an example. Reduced form of glutathione (GH) is a tripeptide with a cysteine residue in the middle. When GH is oxidized, the cysteine residue will form a disulfide bond with the cysteine residue on another GH. Such product is denoted as GSSG. GSSG loses the ability to be a anti-oxidant molecule. Actually, the weakened antioxidant system has been observed in the plasma treated cancer cells. The weakened intracellular anti-oxidant system facilitates the attack of extracellular ROS on cells, and ultimately results in serious ROS rise and oxidative damage including DSB and carbonyl content formation.
[0085] Like other ROS, the toxicity of H 2 O 2 to cells are dose-dependent. Only the high dose of H 2 O 2 can produce cell death. See, Lopez-Lazaro, M. Dual role of hydrogen peroxide in cancer: possible relevance to cancer chemoprevention and therapy. Cancer letters 252, 1-8 (2007). The toxicity of H 2 O 2 is exaggerated by the Fenton reaction between H 2 O 2 and Fe 2+ in cells, which generates high reactive OH and causes damage to DNA and other important intracellular molecules 57 . H 2 O 2 has been proposed as a key species to cause the death of cancer cells after CAP treatment. However, the biochemical analysis on the cancer cells following the treatment of CAP and H 2 O 2 demonstrates the distinct phosphorylation levels on c-Jun amino-terminal kinases and p38 protein kinases. Our study revealed that the H 2 O 2 rich media could not generate the same selective killing on cancer cell lines as well as the CAPs media did. Thus, the CAP treatment can not equate to the H 2 O 2 treatment.
[0086] In contrast to H 2 O 2 , NO was not likely to be the main effective species. However, the real role of NO in killing cancer cells was not deeply explored. Theoretically, NO may result in the general observed ROS increase and the death of cancer cells after CAP treatment. NO is able to increase intracellular ROS levels by blocking the electron transport chain in mitochondria and inactivating the glutathione peroxidase. NO reacts with superoxide to generate peroxynitrite, which will not only attack DNA but also weaken the antioxidant system via the inactivation of manganese-superoxide dismutase, glutathione peroxidase, glutathione reductase, catalase, and peroxiredoxin. In addition, other effective species which have not been studied may also contribute to the death of cancer cells. Thus, the number of species that codetermine the anti-cancer capacity of CAPs media is still unknown.
[0087] Recently, two trends regarding the response of cancer cells to the CAP treatment have been found. First, the anti-tumor capacity of CAP on cancer cells is proportional to the growth speed of cancer cell lines. Naciri, M., Dowling, D. & Al-Rubeai, M. Differential Sensitivity of Mammalian Cell Lines to Non-Thermal Atmospheric Plasma. Plasma Processes and Polymers 11, 391-400 (2014). Second, the cancer cells carrying mutated p53 genes are more vulnerable to the CAP treatment than the cancer cells carrying wild p53 genes. Ma, Y. et al. Non-Thermal Atmospheric Pressure Plasma Preferentially Induces Apoptosis in p53-Mutated Cancer Cells by Activating ROS Stress-Response Pathways. PloS one 9, e91947 (2014). The second trend might explain the first trend to some extent. Cancer cell lines carrying the mutated p53 gene tend to obtain malignant or metastasis phenotypes and overcome growth arrest and senescence. The cancer cells in metastasis stage own prosperous metabolism and high ROS level. Thus, the fast growing cancer cells without a normal, functional p53 gene are more vulnerable to the CAP treatment. In the above example, however, we found a new trend that the cancer cells that could absorb or eliminate the effective species in the surrounding environment faster would be more resistant to the CAPs media. Despite the fact that the intrinsic relationship between these trends was obscure, we demonstrated that the absorption capacity on the effective species and H 2 O 2 by cancer cells significantly varied with the cell lines.
[0088] The absorption of reactive species, mainly H 2 O 2 in this study, directly relates to the diffusion speed of reactive species across the cellular membrane. H 2 O 2 has been regarded as a molecule that is able to freely cross the phospholipid membrane. Recent investigations revealed that diffusion of H 2 O 2 across phospholipid membrane was limited by the membrane composition. Bienert, G. P., Schjoerring, J. K. & Jahn, T. P. Membrane transport of hydrogen peroxide. Biochimica et biophysica acta 1758, 994-1003 (2006). Due to the highly similarity among H 2 O 2 and water, aquaporins (AQPs), a membrane protein family facilitating the transport of water across the cellular membrane, also plays an important role in facilitating the passive diffusion of H 2 O 2 . Not all AQPs are able to transport H 2 O 2 . So far, only the transport of H 2 O 2 by AQP1 and AQP8 has been investigated. AQP1 with a relative smaller pore diameter in the selectivity filter region ((2.7 Å) cannot transport H 2 O 2 . By contrast, due to the larger pore diameter (3.2 Å), AQP8 is able to transport H 2 O 2 across the cellular membrane. AQPs are expressed to varying degrees in different types of human tumors. For example, AQP1, 4, and 5 highly express in breast cancer cell lines. AQP1, 4, 8, and 9 highly express in glioblastoma cell lines. The distinct expression pattern of AQP8 in glioblastoma cells and breast cancer cells can explain why H 2 O 2 is consumed faster by U87 cells than MCF-7 and MDA-MB-231. Nonetheless, if H 2 O 2 is the main effective species to kill cancer cells, the intracellular H 2 O 2 level should be at least codetermined by the diffusion speed of H 2 O 2 across the cell membrane and the intracellular H 2 O 2 scavenging system. Thus, we may not be able to predict the vulnerability of cancer cells to the CAPs media only based on the distinct consumption speeds of cancer cells. More research focusing the intracellular H 2 O 2 scavenging capacity in distinct cancer cells should be carried out in the future.
CONCLUSIONS
[0089] In summary, we demonstrated several principles to optimize the anti-tumor capacity of the CAPs media on glioblastoma cells and breast cancer cells. Specifically, a larger well, a closer gap between plasma source and media, and a smaller volume of media produce a stronger anti-cancer CAPs media. Breast cancer cells are more vulnerable to the CAPs media than glioblastoma cells. In addition, compared with NO, H 2 O 2 in the CAPs media is likely to be the main effective species to kill cancer cells. The effective species in the CAPs media mainly react with cysteine, which explains the rise of intracellular ROS in the CAP treated cancer cells. H 2 O 2 and the CAPs media cause distinct selective killing patterns in cancer cells, indicating that other reactive species may also affect the death of cancer cells. Glioblastoma cells are able to consume effective species and H 2 O 2 in the CAPs media significantly faster than breast cancer cells, which may relate to the distinct expressions of cell membrane proteins on cancer cells.
[0090] The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein.
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A method for preparing cold atmospheric plasma stimulated cell culture media with a cold atmospheric plasma system having a delivery port out of which an inert gas flows. The inert gas may be helium. The method comprises the steps of placing a cell culture media in a first well, the first well having a bottom and having a diameter greater than 20 mm; wherein the cell culture media placed in the first well has a volume of 4 ml or less, treating the cell culture media in the first well with cold atmospheric plasma, wherein the treating is performed with a gap between the delivery port and the bottom of the first well is between 2.5 cm and 3.5 cm, and transferring a portion of the treated media to cultured cancer cells in a second well. The cold atmospheric plasma may be applied for 0.5 minutes to 2 minutes.
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[0001] This application claims priority under 35 USC §119(e)(1) of Provisional Application No. 60/434,176 (TI-34670P) filed Dec. 17, 2002.
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Swoboda, Bryan Thome and Manisha Agarwala, filed on even date herewith, and assigned to the assignee of the present application; U.S. Patent Application (Attorney Docket No. TI-34666), entitled APPARATUS AND METHOD FOR TRACE STREAM IDENTIFICATION OF A PIPELINE FLATTENER SECONDARY CODE FLUSH FOLLOWING A RETURN TO PRIMARY CODE EXECUTION, invented by Gary L. Swoboda, Bryan Thome and Manisha Agarwala filed on even date herewith, and assigned to the assignee of the present application; U.S. Patent Application (Docket No. TI-34667), entitled APPARATUS AND METHOD IDENTIFICATION OF A PRIMARY CODE START SYNC POINT FOLLOWING A RETURN TO PRIMARY CODE EXECUTION, invented by Gary L. Swoboda, Bryan Thome and Manisha Agarwala, filed on even date herewith, and assigned to the assignee of the present application; U.S. Patent Application (Attorney Docket No. TI-34668), entitled APPARATUS AND METHOD FOR IDENTIFICATION OF A NEW SECONDARY CODE START POINT FOLLOWING A RETURN FROM A SECONDARY CODE EXECUTION, invented by Gary L. Swoboda, Bryan Thome and Manisha Agarwala, filed on even date herewith, and assigned to the assignee of the present application; U.S. Patent Application (Attorney Docket No. TI-34669), entitled APPARATUS AND METHOD FOR TRACE STREAM IDENTIFICATION OF A PAUSE POINT IN A CODE EXECTION SEQUENCE, invented by Gary L. Swoboda, Bryan Thome and Manisha Agarwala, filed on even date herewith, and assigned to the assignee of the present application; U.S. Patent Application (Attorney Docket No. TI-34671), entitled APPARATUS AND METHOD FOR TRACE STREAM IDENTIFCATION OF MULTIPLE TARGET PROCESSOR EVENTS, invented by Gary L. Swoboda and Bryan Thome, filed on even date herewith, and assigned to the assignee of the present application; and U.S. Patent Application (Attorney Docket No. TI-34672 entitled APPARATUS AND METHOD FOR OP CODE EXTENSION IN PACKET GROUPS TRANSMITTED IN TRACE STREAMS, invented by Gary L. Swoboda and Bryan Thome, filed on even date herewith, and assigned to the assignee of the present application are related applications.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention relates generally to the testing of digital signal processing units and, more particularly, to the signals that are transmitted from a target processor to a host processing unit to permit analysis of the target processor operation. Certain events in the target processor must be communicated to the host processing unit along with contextual information. In this manner, the test and debug data can be analyzed and problems in the operation of the target processor identified.
[0005] 2. Description of the Related Art
[0006] As microprocessors and digital signal processors have become increasingly complex, advanced techniques have been developed to test these devices. Dedicated apparatus is available to implement the advanced techniques. Referring to FIG. 1, a general configuration for the test and debug of a target processor 12 is shown. The test and debug procedures operate under control of a host processing unit 10 . The host processing unit 10 applies control signals to the emulation unit 11 and receives (test) data signals from the emulation unit 11 by cable connector 14 . The emulation unit 11 applies control signals to and receives (test) signals from the target processing unit 12 by connector cable 15 . The emulation unit 11 can be thought of as an interface unit between the host processing unit 10 and the target processor 12 . The emulation unit 11 processes the control signals from the host processor unit 10 and applies these signals to the target processor 12 in such a manner that the target processor will respond with the appropriate test signals. The test signals from the target processor 12 can be a variety types. Two of the most popular test signal types are the JTAG (Joint Test Action Group) signals and trace signals. The JTAG protocol provides a standardized test procedure in wide use in which the status of selected components is determined in response to control signals from the host processing unit. Trace signals are signals from a multiplicity of selected locations in the target processor 12 during defined period of operation. While the width of the bus 15 interfacing to the host processing unit 10 generally has a standardized dimension, the bus between the emulation unit 11 and the target processor 12 can be increased to accommodate an increasing amount of data needed to verify the operation of the target processing unit 12 . Part of the interface function between the host processing unit 10 and the target processor 12 is to store the test signals until the signals can be transmitted to the host processing unit 10 .
[0007] In the prior art, the trace streams carry test and debug data from the target processor to the host processing unit in signal groups, the signal groups including signal packets. The trace packets are groups of data, a plurality of packets typically being transmitted together. The packets can be relatively small, e.g., each packet has an 8 bit payload (information signal group) in the preferred embodiment. The small size of the packets permits great flexibility in transmission through non-standardized interfaces. One of the trace streams is typically a timing trace stream. Each timing packet group typically includes a header packet and a plurality of information packets. The timing data identifies an activity or a non-activity of the program counter during each clock cycle. Therefore, a logic signal must be transmitted for each clock cycle of the target processing unit in order to reconstruct the activity of the target processor. Moreover, an appreciable part of the bandwidth of the trace streams can be used in transmission of the timing data. Because of the large amount of data that must be transmitted from the increasingly complex target processors to host processing unit for analysis, minimizing the transmission of data is important.
[0008] A need has been felt for apparatus and an associated method having the feature of reducing the amount of information that must be transmitted by the trace stream to the host processing unit. It would be another feature of the apparatus and associated method to reduce the amount of information used to represent the timing parameters of target processing unit. It would be yet another feature of the apparatus and associated method to provide flexibility in transmitting data in timing packet groups. It would a still another feature of the apparatus and associated method to provide timing packet groups capable of compressing the timing information of the target processor. It is a more particular feature of the apparatus and associated method to replace a timing packet group in which each data bit position represents the same logic signal with a smaller timing packet group.
SUMMARY OF THE INVENTION
[0009] The aforementioned and other features are accomplished, according to the present invention, by providing timing trace generation unit that has a first storage unit wherein a sequence of logic signals relating to the activity of the program counter associated with each clock cycle is formed into packet groups. The contents of the first storage unit are typically transferred to the host processing unit for analysis. A second storage unit includes a count of the number of bit positions for storing the logic signals of the first storage unit. A logic unit determines when all of the signals in the first storage unit have the same logic value. When this determination is made, an indicia of the same logic value is stored in a header portion of the second storage unit and the contents of the second storage unit are transmitted to the host processing unit in place of the contents of the first storage unit. Because the second storage unit is smaller than the first storage unit, a saving in the amount of transmitted information is achieved.
[0010] Other features and advantages of present invention will be more clearly understood upon reading of the following description and the accompanying drawings and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a general block diagram of a system configuration for test and debug of a target processor according to the prior art.
[0012] [0012]FIG. 2 is a block diagram of selected components in the target processor used the testing of the central processing unit of the target processor according to the present invention.
[0013] [0013]FIG. 3 is a block diagram of selected components of the illustrating the relationship between the components transmitting trace streams in the target processor.
[0014] [0014]FIG. 4A illustrates format by which the timing packets are assembled according to the present invention; while FIG. 4B illustrates how the packets in the timing trace stream are formed from the timing signals.
[0015] [0015]FIG. 5A illustrates a packet group in a typical timing trace stream, while FIG. 5B illustrates a compressed packet group according to the present invention.
[0016] [0016]FIG. 6 is a block diagram for generating either a typical group of packets or a compressed group of packets according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] 1. Detailed Description of the Figures
[0018] [0018]FIG. 1A and FIG. 1B have been described with respect to the related art.
[0019] Referring to FIG. 2, a block diagram of selected components of a target processor 20 , according to the present invention, is shown. The target processor includes at least one central processing unit 200 and a memory unit 208 . The central processing unit 200 and the memory unit 208 are the components being tested. The trace system for testing the central processing unit 200 and the memory unit 202 includes three packet generating units, a data packet generation unit 201 , a program counter packet generation unit 202 and a timing packet generation unit 203 . The data packet generation unit 201 receives VALID signals, READ/WRITE signals and DATA signals from the central processing unit 200 . After placing the signals in packets, the packets are applied to the scheduler/multiplexer unit 204 and forwarded to the test and debug port 205 for transfer to the emulation unit 11 . The program counter packet generation unit 202 receives PROGRAM COUNTER signals, VALID signals, BRANCH signals, and BRANCH TYPE signals from the central processing unit 200 and, after forming these signal into packets, applies the resulting program counter packets to the scheduler/multiplexer 204 for transfer to the test and debug port 205 . The timing packet generation unit 203 receives ADVANCE signals, VALID signals and CLOCK signals from the central processing unit 200 and, after forming these signal into packets, applies the resulting packets to the scheduler/multiplexer unit 204 and the scheduler/multiplexer 204 applies the packets to the test and debug port 205 . Trigger unit 209 receives EVENT signals from the central processing unit 200 and signals that are applied to the data trace generation unit 201 , the program counter trace generation unit 202 , and the timing trace generation unit 203 . The trigger unit 209 applies TRIGGER and CONTROL signals to the central processing unit 200 and applies CONTROL (i.e., STOP and START) signals to the data trace generation unit 201 , the program counter generation unit 202 , and the timing trace generation unit 203 . The sync ID generation unit 207 applies signals to the data trace generation unit 201 , the program counter trace generation unit 202 and the timing trace generation unit 203 . While the test and debug apparatus components are shown as being separate from the central processing unit 201 , it will be clear that an implementation these components can be integrated with the components of the central processing unit 201 .
[0020] Referring to FIG. 3, the relationship between selected components in the target processor 20 is illustrated. The data trace generation unit 201 includes a packet assembly unit 2011 and a FIFO (first in/first out) storage unit 2012 , the program counter trace generation unit 202 includes a packet assembly unit 2021 and a FIFO storage unit 2022 , and the timing trace generation unit 203 includes a packet generation unit 2031 and a FIFO storage unit 2032 . As the signals are applied to the packet generators 201 , 202 , and 203 , the signals are assembled into packets of information. The packets in the preferred embodiment are 10 bits in width. Packets are assembled in the packet assembly units in response to input signals and transferred to the associated FIFO unit. The scheduler/multiplexer 204 generates a signal to a selected trace generation unit and the contents of the associated FIFO storage unit are transferred to the scheduler/multiplexer 204 for transfer to the emulation unit. Also illustrated in FIG. 3 is the sync ID generation unit 207 . The sync ID generation unit 207 applies an SYNC ID signal to the packet assembly unit of each trace generation unit. The periodic signal, a counter signal in the preferred embodiment, is included in a current packet and transferred to the associated FIFO unit. The packet resulting from the SYNC ID signal in each trace is transferred to the emulation unit and then to the host processing unit. In the host processing unit, the same count in each trace stream indicates that the point at which the trace streams are synchronized. In addition, the packet assembly unit 2031 of the timing trace generation unit 203 applies and INDEX signal to the packet assembly unit 2021 of the program counter trace generation unit 202 . The function of the INDEX signal will be described below.
[0021] Referring to FIG. 4A, the assembly of timing packets is illustrated. The signals applied to the timing trace generation unit 203 are the CLOCK signals and the ADVANCE signals. The CLOCK signals are system clock signals to which the operation of the central processing unit 200 is synchronized. The ADVANCE signals indicate an activity such as a pipeline advance or program counter advance (( )) or a pipeline non-advance or program counter non-advance (1). An ADVANCE or NON-ADVANCE signal occurs each clock cycle. The timing packet is assembled so that the logic signal indicating ADVANCE or NON-ADVANCE is transmitted at the position of the concurrent CLOCK signal. These combined CLOCK/ADVANCE signals are divided into groups of 8 signals, assembled with two control bits in the packet assembly unit 2031 , and transferred to the FIFO storage unit 2032 .
[0022] Referring to FIG. 4B, the trace stream generated by the timing trace generation unit 203 is illustrated. The first (in time) trace packet is generated as before. During the assembly of the second trace packet, a SYNC ID signal is generated during the third clock cycle. In response, the timing packet assembly unit 2031 assembles a packet in response to the SYNC ID signal that includes the sync ID number. The next timing packet is only partially assembled at the time of the SYNC ID signal. In fact, the SYNC ID signal occurs during the third clock cycle of the formation of this timing packet. The timing packet assembly unit 2031 generates a TIMING INDEX 3 signal (for the third packet clock cycle at which the SYNC ID signal occurs) and transmits this TIMING INDEX 3 signal to the program counter packet assembly unit 2031 .
[0023] Referring to FIG., 5 A, a typical packet group 50 in the timing stream is illustrated. The packet group consists of four packets 502 , each packet 502 having an 8 bit payload. In the preferred embodiment, an addressable memory location in the host processing unit stores 32 bits. The 2 bit control signals indicated that what is being transmitted in the timing trace stream is a series of 8 bit payload packets. As indicated above, the timing trace stream includes periodic sync markers that can synchronize the plurality of trace streams.
[0024] Referring to FIG. 5B, compressed packet group 55 , according to the present invention, is shown. In this packet group 55 , a 10 bit packet is transmitted. However, the control signals are selected to indicate that a different interpretation of the payload is required. In particular, the payload is an indication of the number of 32 bit timing packets, coincident with the memory location boundaries that transmit the same logic signal. If, for example, the packet group 50 included logic signals having the same value, then the packet group 50 is replaced by a packet 55 . Several consecutive packets groups 50 , in which the payload of each packet 502 has the same logic value, can be replaced by the packet 55 . The packet 55 identifies the number of packet groups 50 having the same logic signal group in the packet payloads. In this manner, the timing trace stream can be compressed.
[0025] Referring to FIG. 6, a block diagram of the timing stream generation unit 203 capable of performing the compression of the timing trace stream is shown. The packet assembly unit 2031 includes two storage units 20311 and 20312 , a logic unit 20314 , and a switch 20313 . The timing sequence signals, a logic “1” or a logic “0” during each clock cycle is applied to storage unit 20311 , to logic unit 30314 , and to storage unit 20312 . The timing sequence signals applied to storage unit 20311 fill the 32 bit (payload) positions in packet group 50 . At the same time, the timing sequence signals are applied to the logic bit position 551 A of the header packet 551 of the compressed packet group. In addition, the timing sequence signals are applied to the logic unit 20314 . When the first bit position is filled in the storage unit, the logic unit begins to count the applied logic signals. When the first signal is entered in the storage unit 20311 , the first count has been made in logic unit 20314 . When the count in logic unit 20314 reaches 32, a control signal is applied to switch 20313 . When all the logic signals of the timing sequence have the same value, a first control signal applied to the switch results in the contents of storage unit 20312 (i.e., packet group 55 ) being applied to the FIFO unit 2032 . Because the timing sequence signals are applied to the header location 551 A in storage unit 20312 , when the packet group from storage unit 20312 is transferred to the FIFO unit, the logic signal in location 551 A is the logic signal to which the 32 count of packet 55 refers. When the logic signals applied to logic unit 20314 have different logic states during the 32 clock cycles during which the storage unit 20311 is filled, a second logic signal from the logic unit 20314 applied to switch 20313 results in the contents of storage unit 20311 (i.e., packet group 50 ) being applied to the FIFO unit 2032 .
[0026] 2. Operation of the Preferred Embodiment
[0027] The present invention is directed toward minimizing the amount of data transferred from the target processor to the host processing unit while accurately reflecting the operation of the target processor. The present invention provides for the compression of the timing trace stream. This compression of the timing trace stream is the result of the recognition that many situations occur when a lengthy sequence of all logic “1”s or of all logic “0”s can occur. When the sequence of the same logic signals coincides with the a normal timing stream packet group as determined by the filling of the storage locations of the first storage unit in FIG. 6, a small packet group can be used to replace the typical normal timing stream trace group. The normal timing trace stream packet group has a predetermined payload (i.e., standard count of clock cycles) in each multi-packet group. This payload is selected to expedite storage of the logic signals in storage unit of the host processing unit.
[0028] As indicated in FIG. 5B, the standard count is included in information packet. A second packet is needed because it may be expedite for testing different target devices to be capable of programming signal group in the information packet. In addition, the logic unit may be chosen to identify one than one standard count of clock cycle. In this embodiment, the logic device can identify the number of standard count of clock cycles and enter this number in information packet. In this embodiment, the compressed timing packet group is transferred to the FIFO unit when, after the first standard count of clock cycles is completed, a different logic value is identified.
[0029] When the standard count of clock cycles is non-changing, than the transmission of the header packet alone can provide the information concerning the single logic signal during the standard count of clock cycles. When the logic signal does not change for more than one standard count of clock cycles, then the number of standard clock cycles can be included in the information packet or in the header packet of the compressed timing group.
[0030] While the present timing trace stream has used the control signals to describe the function of the associated packet, the used o packets groups with header could also be used to interpret the payload of the packet. The present invention provides a technique for compressing this timing trace stream format.
[0031] While the invention has been described with respect to the embodiments set forth above, the invention is not necessarily limited to these embodiments. Accordingly, other embodiments, variations, and improvements not described herein are not necessarily excluded from the scope of the invention, the scope of the invention being defined by the following claims.
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In a test and debug system, a plurality of trace streams, including a timing trace stream, are transmitted from the target processing unit to the host processing unit for analysis. The timing trace stream, the trace stream that indicates activity or non-activity of the program counter each clock cycle, can occupy a large percentage of the bandwidth of the transmitted data. The transmitted data is organized into groups of packets, each packet having a control signal portion and a payload portion. Each information packet has a logic signal stored at each location indicating an activity or a non-activity of the program counter. By identifying portion of the timing trace stream wherein the activity or non-activity does not change for one or more groups of timing packets, the information in a plurality of packets can be represented by a header and an information packet that describes a number of packets in which the activity or non-activity of the program counter does not change.
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TECHNICAL FIELD
[0001] The invention relates generally to the field of computer systems and, more particularly, to small cache systems in microprocessors.
BACKGROUND
[0002] High performance processing systems require fast memory access and low memory latency, to quickly get data to process. Because system memory can be slow to provide data to a processor, caches are designed to provide a way to keep data close to the processor with quicker access time for its data. Larger caches give better system performance overall but inadvertently can induce more latency and design complexities compared to smaller caches. Generally, smaller caches are designed to provide a fast way for a processor to synchronize or communicate to other processors in system applications level, especially in networking or graphics environment.
[0003] Processors send data to memory and retrieve data from memory, through Load and Store commands, respectively. Data from a system memory fills up the cache. A desirable condition is where most or all of data to be accessed by the processor is in the cache. This could happen if an application data size is same or smaller than the cache size. In general, cache size is usually limited by design or technology and can not contain the whole application data. This can be a problem when the processor accesses the new data, not in the cache, and no cache space is available to put the new data. Hence, the cache controller needs to find an appropriate space in the cache for the new data when it arrives from memory.
[0004] An LRU (Least Recently Used) algorithm is used by a cache controller to handle this situation. The LRU algorithm determines which location to be used for the new data based on the data access history information. If LRU selects a line which is consistent with the system memory, for example, shared state, then the new data will be over written to that location. When LRU selects a line that is marked Modified, which means that data is not consistent with the system memory and unique, cache controller forces the Modified data of this location to be written back to the system memory. This action is called a write back, or a castout, and the cache location that contains the write back data is called Victim Cache Line.
[0005] A bus agent, the bus interface unit that handles the bus command for the cache, attempts to complete the write back operation as soon as it could, by sending the data to the system memory via Bus operations. Write back (“WB”) or write back is a long latency bus operation since the data is going to the main memory.
[0006] There are two different kinds of cache control schemes. These are coherent cache scheme and non-coherent. In non-coherent, each cache has a unique copy of the data, and there can be no other cache with the same data. This approach is relatively easy to implement. However, this is inefficient, because there may be times when data should be distributed throughout a multiprocessor system. Therefore, a coherency cache scheme can be used, which ensures that the most up-to date data is used, distributed, or otherwise marked as valid.
[0007] One conventional technology that enforces coherency is the Modified, Exclusive, Shared, and Invalid (MESI) system. In MESI, data in a cache in a multiprocessor system is marked as one of the above, to ensure data coherency. The marking is done by hardware, the memory flow controller.
[0008] Snooping is the process whereby slave caches watch the system bus and compare the transferred address to addresses in the cache directory in order to keep the cache coherency. Additional operations can be performed in the case that a match is found. The terms bus snooping or bus watching are equivalent.
[0009] An invalidate command which is used as part of a snoop command, is issued to tell the other caches that their data is no longer valid and should mark that line invalid. In other words, the invalid state indicates that the line in the cache is invalid in the cache, or that the line is no longer available. Therefore, this line of data within the cache is free to be overwritten by other data transfers.
[0010] In a multi-processor system, some operations like test&set, compare&swap, or fetch&increment (or decrement) needs to be processed inseparably (that is, no other store to the same address can occur in between them). These operations are so called atomic operations. In general these operations are used for lock acquisition or semaphore operations. But some implementations provide only small building blocks like LL(Load-Locked) and SC(Store-Conditional) to build such a more functional operations. And some processors introduce Reservation flag to tie up these two operations (LL and SC) atomically together (that is, LL set up Reservation for lock variable, and SC can successfully store if that Reservation remains. Any store operation to same address can reset Reservation flag.)
[0011] In general Atomic-Facility is implemented at coherency point like a snoop cache to snoop other processor's store operations, and also to improve performance by caching a lock line. When performing atomic line data requests, there are a number of different commands. The first is load and reserve instruction. Load and reserve is issued by a source processor and looks at its associated cache to determine whether the cache has the data requested. If the target cache has the data, then a “reservation” flag is set for that cache. The reservation flag means that the processor is making a reservation for that line for lock acquisition. In another words, a lock acquisition (gaining a sole ownership) of a block of data in main memory is accomplished by first making a reservation using Load and Reserve and then modifying the reserved line to indicate its ownership via Store conditional instruction. Store conditional is conditional on the reservation flag is still active. Reservation can be lost by other processors wanting the same lock acquisition by executing Store conditional instruction or other reservation kill type snoop commands on the same line. The processor then copies the reserved information from the cache into the processor for processing Load and Reserve. Basically the processor is looking for an indication in the reserved line for unlocked data pattern so that Store conditional can be executed to complete the lock.
[0012] However, if the cache does not have the information, a BUS command is generated to try to get the information. If no other cache has the information, the data is retrieved from main memory. Once the data is received, reservation flag is set.
[0013] Due to the characteristic of the atomic operation tight loop and high likelihood of using the same lock again in normal programming, a reserved line from a first lock acquisition loop is needed for the future lock acquisitions. Hence this reserved data from the Load and Reserve instruction should not be written back to main memory as a write back, since the ownership of same data is needed for the subsequent lock acquisition loop. This improves performance since the reserved line write back and reload of same data from main memory is eliminated.
[0014] Therefore, there is a need for an atomic facility that addresses at least some of the problems associated with conventional atomic reservations.
SUMMARY OF THE INVENTION
[0015] The present invention provides for managing an atomic facility cache write back controller. A reservation pointer pointing to the reserved line in the atomic facility cache data array is established. An entry for the reservation point for the write back selection is removed whereby the valid reservation line is precluded from being selected for the write back. In one aspect, a write back selection is made by employment of a least recently used (LRU) algorithm. In a further aspect, the write back selection is made with respect to reservation pointer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following Detailed Description taken in conjunction with the accompanying drawings, in which:
[0017] FIG. 1 schematically depicts a multi-processing system;
[0018] FIG. 2 schematically depicts an atomic facility cache;
[0019] FIG. 3 schematically illustrates a Lock acquisition command example;
[0020] FIG. 4 illustrates a write back operation flow chart; and
[0021] FIG. 5 illustrates an example block diagram of an atomic facility cache.
DETAILED DESCRIPTION
[0022] In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without such specific details. In other instances, well-known elements have been illustrated in schematic or block diagram form in order not to obscure the present invention in unnecessary detail. Additionally, for the most part, details concerning network communications, electro-magnetic signaling techniques, and the like, have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the present invention, and are considered to be within the understanding of persons of ordinary skill in the relevant art.
[0023] In the remainder of this description, a processing unit (PU) may be a sole processor of computations in a device. In such a situation, the PU is typically referred to as an MPU (main processing unit). The processing unit may also be one of many processing units that share the computational load according to some methodology or algorithm developed for a given computational device. For the remainder of this description, all references to processors shall use the term MPU whether the MPU is the sole computational element in the device or whether the MPU is sharing the computational element with other MPUs, unless otherwise indicated.
[0024] It is further noted that, unless indicated otherwise, all functions described herein may be performed in either hardware or software, or some combination thereof. In a preferred embodiment, however, the functions are performed by a processor, such as a computer or an electronic data processor, in accordance with code, such as computer program code, software, and/or integrated circuits that are coded to perform such functions, unless indicated otherwise.
[0025] Turning to FIG. 1 , disclosed is a multi-processor system 100 with a general central processor unit (MPU 1 ) 110 , (MPU 2 ) 111 which can include an instruction unit, instruction cache, data cache, fixed point unit, floating point, local storage, and so on. Each processor is connected to a lower level cache called Atomic Facility (AF). Atomic Facility (AF 1 Cache) 120 , (AF 2 Cache) 121 is connected to the Bus Interface unit (Bus IF) 130 , (Bus IF) 131 and which in turn connects to the System Bus 140 . Other processor's caches are connected to the system bus via bus interface units to have inter-processor communications. In addition to processors, a memory controller (Mem Ctr 1 ) 150 is attached to the system bus 140 as well. A System Memory 151 is connected to the memory controller for common storage shared by multiple processors.
[0026] Generally, the system 100 provides a mechanism to disable write back operation on the reserved line from a Load and Reserve instruction of the lock acquisition software loop. The reserved line from the Load and reserve instruction is used in subsequent Store condition instruction in this lock acquisition loop. Hence, by keeping the reserved line in the cache, instead of writing back to memory and bring it back, is better in performance. By using various pointers, the victim line for write back is selected by LRU algorithm and the reservation line is not selected by skipping over this pointer.
[0027] Turning now to FIG. 2 , the view of an atomic facility 142 (hereafter referred to variably as “atomic facility” or “AF 142 ” is disclosed in more detail. Atomic facility includes data array circuitry 146 for data array and its control logic. Control logic includes a directory 147 , RC (Read and Claim) finite state machine 143 , to handle instructions from processor core, WB (write back) state machine to handle write back 144 and Snoop state machine 145 . Directory 147 holds the cache tags and its states.
[0028] The RC machine 143 executes atomic instructions called, load and reserve, store conditional instructions for inter process synchronization. One purpose of this series of instructions is to synchronize operations between processors by giving ownership of common data to a processor in orderly fashion in multi-processor system.
[0029] A purpose, generally, of this series of instructions, is to synchronize operations between processors by giving ownership of the data to one processor at a time in multi-processor system. WB machine 144 handles write back for the RC machine when cache miss occur for load or store operations issued by MPU and when the atomic facility (AF) cache is full, and victim entry is modified state. Snoop machine 145 handles snoop operations coming from the system bus to maintain memory coherency throughout the system.
[0030] Turning now to FIG. 3 , illustrated is an example of Lock acquisition scenario between 2 processors in a multi-processor system. Lock acquisition operation entails two main atomic instructions, a Load and Reserve atomic instruction, a Store conditional atomic instruction.
[0031] The Lock acquisition scenario as in MPU 1 will first loop on Load and Reserve at “A” instruction until the released lock data pattern, zero's for simplicity, is loaded. During this instruction, a reservation flag is set with the reservation address in the RC machine. Once a lock is released by another processor, it can continue on to the next instruction called Store Conditional at “A”. This is a step to finalize the lock by storing its processor ID into the atomic line at address “A”. However this Store is conditional on reservation flag still being active. Another processor could have issued a store command to acquire same lock right before this Store conditional instruction.
[0032] Since cache coherency protocol is engaged on Atomic Facility cache, this store can be snooped by receiving a cache-line-kill or a read-exclusive snoop command on the same lock line address, which kills the current reservation.
[0033] Once the lock is achieved by successful Store conditional, a reservation flag is reset. If lock acquisition is unsuccessful, it restarts from load and reserve again. Therefore, the processor has a full ownership of the common storage area to do its work. During this time, other processors are lock out for any access to the common area. Once the work is completed, it releases the lock by storing ‘0’ to address “A.” At this time, a second processor, MPU 2 can attain a lock when the second processor acquires the latest “A” data for the Load and Reserve instruction seeing the zero data pattern. The second processor continues with Store conditional instruction to finalize the lock as described above on the first processor.
[0034] Software has a tendency to reuse same lock line again, because in many cases lock acquisition is done in loop structure. So it is always good idea to preserve previous reservation line, because synchronization performance is critical for multi processor communication, and once lock line is invalidated from local cache, there is always serious performance degradation for atomic instructions.
[0035] Turning now to FIG. 4 , illustrated is one embodiment method 400 of write back operation. Generally, the method 400 describes a decision making process on the write back, as to whether write back is needed or not. Generally, this example implementation is such that the atomic facility (AF 142 ) has only one write back (WB) machine.
[0036] A write back request is dispatched by a ‘read and claim’ (RC) machine when load or store instructions and a directory lookup occur. In step 402 , it is determined whether there is an executed RC miss on DIR (Directory) lookup and there is no room in the AF. If there is not, then in step 407 (will add), it is determined that a write back is not needed, and the method ends.
[0037] In step 403 , the RC dispatches WB machine right after DIR lookup 301 and found a miss with no empty space ( 302 and 303 ) in Data Array. If there is an empty space in Data Array, then write back is not needed. If there is not an empty space, step 404 executes.
[0038] In step 404 , the victim entry is chosen by the least recently used algorithm. If the designated least-recently-used victim entry 404 is modified, WB has to write the modified line 405 back to memory in order to make a room in AF.
[0039] In step 405 , it is determined whether the victim entry is modified. If no, step 407 executes, and write back is deemed not to be needed. WB machine selects victim entry by using the Least Recently Used algorithm, modified and skips over the reservation entry. It continues with storing the victim entry to the memory to complete the write back operation 406 .
[0040] Turning now to FIG. 5 , illustrated is a system 500 to manage the Atomic Facility 120 , there is a pointer to point the cache line in Atomic Facility Data cache where Reservation exists. A victim pointer is used to write back a modified entry when there is a miss from an atomic instruction; the victim pointer denotes which information is to be written back out of the atomic cache, when the missed data is being reloaded. Since LRU algorithm never select Reservation pointer as victim pointer, the Load and Reserve data will never be written back to memory since it is used on subsequent Store conditional instruction. Therefore this capability will improve over all performance of an atomic operation in the Atomic Facility cache.
[0041] It is understood that the present invention can take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or the scope of the invention. The capabilities outlined herein allow for the possibility of a variety of programming models. This disclosure should not be read as preferring any particular programming model, but is instead directed to the underlying mechanisms on which these programming models can be built.
[0042] Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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The present invention provides for managing an atomic facility cache write back state machine. A first write back selection is made. A reservation pointer pointing to the reserved line in the atomic facility data array is established. A next write back selection is made. An entry for the reservation point for the next write back selection is removed, whereby the valid reservation line is precluded form being selected for the write back. This prevents a modified command from being invalidated.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2006-292581, filed on Oct. 27, 2006 and No. 2007-250167, filed on Sep. 26, 2007; the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a generating device of trigger signal which generates a trigger signal so as to shift the state of an appliance by receiving a radio signal.
2. Description of the Related Art
Such an electrical appliance as a television set can be generally switched on and off with the corresponding remote control. An optical signal emitted from the remote control is received at the electrical appliance so that the electrical appliance is switched on. In order to realize the operation of the switch-on of the electrical appliance, the optical receiver and the electrical power controller in the electrical appliance are always set operable. Namely, even though the electrical appliance is not switched on, some electrical power is always consumed because the optical receiver and the electrical power controller are set operable.
As described above, the remote control uses an optical signal. Since the remote control using the optical signal can be manufactured at low cost, the remote control can not perform the optical communication if an obstacle is located between the remote control and the electrical appliance. In this point of view, such a receiving structure as an RFID tag which utilizes an electromagnetic wave is proposed (refer to Reference 1). In Reference 1, in order to reduce the electric power consumption of the electrical appliance at the standby state thereof, a starting switch is inserted between the rectifier of the RFID tag and the electrical appliance. A power source is provided for the starting switch from the electrical appliance and no power source is provided for the rectifier.
The power source for the electrical appliance is controlled in on-off on the basis of the output state of the starting switch. When the starting switch outputs an off signal, the electrical appliance is switched off so that the electric appliance does not consume the electric power. When the staring switch outputs a signal, the electrical appliance is switched on. For example, with a television set, some images are displayed on the screen and some voices and sounds are created. The power source is provided for the starting switch from the electrical appliance, and the power source may be made from a CMOS inverter. In this case, no electrical current is supplied for the starting switch because the nMOS transistor or pMOS transistor of the inverter is set off irrespective of the operation state of the inverter.
The rectifier receives an external electromagnetic wave with the antenna and then, generates the electric voltage through the electric power originated from the electromagnetic wave. The output voltage of the rectifier becomes large as the input electric power into the rectifier becomes large. Since no electric power is supplied to the rectifier from the electric appliance, the standby electric power of the rectifier becomes zero. By inputting the output voltage of the rectifier into the starting switch, the on-off control signal for the electrical appliance can be generated. As a result, the electric power consumption at standby state of the remote control with the inverter as the power source can be reduced in comparison with the remote controller with the optical signal.
However, since the rectifier can generate a smaller electric voltage through the input of the electric power originated from the electromagnetic wave, the starting switch can not be switched on and off only if a larger electric power is input into the starting switch from the rectifier. Namely, it is required to apply a larger electric power to the RFID tag so that the distance between the electric appliance and the remote control can not be enlarged.
It is proposed in References 2 and 3 to render the electric power to be generated from the rectifier large. According to the improved rectifier disclosed in References 2 and 3, therefore, the operable distance of the remote control can be enlarged to some degrees.
[Reference 1] JP-A 2001-197537 (KOKAI)
[Reference 2] JP-A 2006-034085 (KOKAI)
[Reference 3] JP-A 2006-166415 (KOKAI)
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention, in view of the above conventional problem, to provide a generating device of trigger signal which is designed so as to shift the state of an appliance through the reception of a radio signal and configured so as to enlarge the operable distance from the wireless transmitter.
In order to achieve the above object, an aspect of the present invention relates to a trigger signal generating device including: a first power source terminal and a second power source terminal; a first current generator, receiving an input signal, to generate a first current with a first amplitude in accordance with the amplitude of the input signal; a second current generator, receiving the first current of the first current generator, to generate a second current with a second amplitude, the second current being flowed from the first power source terminal to the second power source terminal; a current mirror circuit to amplify the second current generated from the second current generator to obtain an amplified current; and a trigger signal generator to convert the amplified current into a trigger signal used for triggering a trigger device, the voltage amplitude of the trigger signal being corresponding to the current amplitude of the amplified current; wherein both of the first and second current generators are connected to either one of the first power source terminal and the second power source terminal.
In the trigger signal generating device, if a signal is input, the first current generator generates a current with a predetermined amplitude in accordance with the amplitude of the signal. The current is supplied to the second current generator so as to generate another current with another amplitude in accordance with the amplitude of the current. An other current is amplified at the current mirror circuit. Thereafter, the thus obtained amplified current is converted into the corresponding voltage (trigger signal). Therefore, even though the amplitude of the current generated at the first current generator is small, the intended trigger signal with a relatively large amplitude can be obtained. As a result, the state of the appliance can be shifted by the trigger signal so that the distance between a wireless transmitter and the appliance can be elongated.
If the signal is not input, the difference in electric potential between the power source terminal with which the second current generator is connected and the input terminal of the signal amplifier is set equal to the difference in electric potential of the power source terminal with which the first current generator is connected and the output terminal of the first current generator. Therefore, since no current is flowed in the first current generator and the second current generator even though the first current generator and the second current generator are switched off so that the electric consumption of the generators, that is, the trigger signal generating device can be reduced.
According to the aspect can be provide a generating device of trigger signal which is designed so as to shift the state of an appliance through the reception of a radio signal and configured so as to enlarge the operable distance from the wireless transmitter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a circuit diagram relating to the structure of the trigger signal generating device according to an embodiment.
FIG. 2 is a graph showing the input-output current characteristics of the current mirror circuits CM 1 and CM 2 of the trigger signal generating device shown in FIG. 1 .
FIG. 3 is a circuit diagram of the rectifier of the trigger signal generating device shown in FIG. 1 .
FIG. 4 is a circuit diagram relating to the structure of the trigger signal generating device according to another embodiment.
FIG. 5 is a circuit diagram of the power source controller shown in FIG. 1 .
FIG. 6 is a circuit diagram relating to the structure of the trigger signal generating device according to still another embodiment.
FIG. 7 is a circuit diagram of the current generating circuit shown in FIG. 1 .
FIG. 8 is another circuit diagram of the current generating circuit shown in FIG. 1 .
FIG. 9 is still another circuit diagram of the current generating circuit shown in FIG. 1 .
FIG. 10 is a further circuit diagram of the current generating circuit shown in FIG. 1 .
FIG. 11 is a circuit diagram relating to the structure of the trigger signal generating device according to a further embodiment.
FIG. 12 is a circuit diagram comprising the current-voltage converter shown in FIGS. 1 and 6 .
FIG. 13 is a concrete circuit diagram of the current-voltage converter shown in FIGS. 1 and 6 .
FIG. 14 is a graph showing the current-voltage characteristic of the pMOS transistor of the current-voltage converter in FIG. 13 .
FIG. 15 is a circuit diagram relating to the structure of the trigger signal generating device according to a still further embodiment.
FIG. 16 is a circuit diagram relating to the structure of the trigger signal generating device according to another embodiment.
FIG. 17 is a circuit diagram relating to the structure of the trigger signal generating device according to still another embodiment.
FIG. 18 is a flowchart showing the operation of the trigger signal generating device in FIG. 17 .
FIG. 19 is another flowchart showing the operation of the trigger signal generating device in FIG. 17 .
FIG. 20 is still another flowchart showing the operation of the trigger signal generating device in FIG. 17 .
FIG. 21 is a circuit diagram of a cellular phone using the trigger signal generating device in FIG. 17 .
FIG. 22 shows a situation where the cellular phone in FIG. 21 is used.
FIG. 23 is a circuit diagram of a wireless communication device using the trigger signal generating device in FIG. 17 .
DETAILED DESCRIPTION OF THE INVENTION
In an embodiment, the second current generator includes an additional current mirror circuit. In this embodiment, since the current mirror circuit is employed, a current amplifying function can be applied to the second current generator by changing the size(s) of the transistor(s) of the current mirror circuit. Since no current is flowed in the second current generator under the condition of off-state, the electric power consumption in the second current generator can be reduced.
In another embodiment, a plurality of additional current mirror circuits, connected in cascade, may be provided. In this case, the gain of the current amplification can be easily increased and the current direction can be freely controlled (namely, the current can be flowed in forward direction or opposite direction).
In still another embodiment, the first current generator includes a rectifier with an nMOS transistor which is configured such that a rectified voltage is applied to a drain and gate of the nMOS transistor and a standard voltage is applied to a gate of the nMOS transistor. In this case, the intended current with a predetermined amplitude can be easily generated by controlling the amplitude of the signal to be input therein.
In a further embodiment, the second current generator includes a first nMOS transistor and a second nMOS transistor which compose the current mirror circuit, and the current mirror circuit also includes: a first pMOS transistor which is configured such that a drain and gate of the first pMOS transistor are connected with a drain of the second nMOS transistor and a second standard electric potential is applied to a source of the first PMOS transistor; and a second pMOS transistor which is configured such that an amplified current through the signal amplifier is output from a drain of the second pMOS transistor.
In this embodiment, the second current generator generates the current from the first power source terminal to the second power source terminal as describe above and the current is amplified by the current mirror circuit so that the current amplification function can be applied to the second current generator.
In a still further embodiment, the second current generator includes a transistor, and the trigger signal generating device includes an offset compensator for compensating an offset current flowing in a drain of the transistor.
In this embodiment, the offset current (leak current) generated at the transistor of the second current generator can be compensated by the offset compensator when no rectified current is generated so as not to be supplied to the transistor. Therefore, the operations of the components after the second current generator are not affected.
In another embodiment, the trigger signal generator includes: a first nMOS transistor which is configured such that an amplified current through the signal amplifier is flowed from a drain/gate common connection of the first nMOS transistor to a source of the first nMOS transistor; a second nMOS transistor composing an additional current mirror circuit with the first nMOS transistor; a pMOS transistor which is configured such that a drain of the pMOS transistor is connected with a drain of the second nMOS transistor and a standard electric potential is applied to a source of the pMOS transistor; and a biasing voltage generator which is configured such that a voltage generated between a drain/gate common connection of the first nMOS transistor and the source of the first nMOS transistor is input so as to output a nonlinear voltage as a trigger signal in response to an amplitude of the voltage to a gate of the pMOS transistor, wherein the trigger signal is output from a connection node between the drain of the second nMOS transistor and the drain of the PMOS transistor.
In this embodiment, since the biasing voltage to be supplied to the gate of the PMOS transistor is generated by the biasing voltage generator as defined above, the resistance of the PMOS transistor as a load for the first nMOS transistor can be increased as occasion demands. Therefore, the output variable margin of the trigger signal generator can be enlarged. Herein, the trigger signal generator is an input-output inverted current-voltage converter because the voltage to be output is decreased as the amplified current is input.
In still another embodiment, the trigger signal generating device includes: a power source switch which is operated in response to the trigger signal so as to generate and maintain an on-state; a synchronizing circuit for generating a clock signal in synchronization with a variable frequency in output level of the trigger signal generator by the power supply control with the power source switch; a shift resistor for storing a variable hysteresis of the trigger signal generator through the input of the clock signal as a shift signal by the power supply control with the power source switch; a memory for storing a standard information by the power supply control with the power source switch; and a judging circuit for generating an indication signal to indicate that the variable hysteresis in output level is matched with the standard information through the comparison of the variable hysteresis with the standard information by the power supply control with the power source switch.
In this embodiment, the trigger signal is output as an output from the judging circuit and the ID information of the (RF) signal can be determined by the shift resistor and the like. Namely, the trigger signal is judged at the judging circuit whether the trigger signal is exclusively for the intended appliance and thus, can be output for the intended appliance if the trigger signal is exclusively for the intended appliance. In addition, since the synchronizing circuit, the shift resistor and the like is controlled in electric power supply by the power source switch, the electric power saving at off-state can be enhanced.
In a further embodiment, the memory stores a first standard information and a second standard information as the standard information, and the trigger signal generating device includes an additional power source switch which is operated in response to a first indication signal indicating that the variable hysteresis in output level is matched with the first standard information in the judging circuit so as to generate and maintain an off-state and in response to a second indication signal indicating that the variable hysteresis in output level is matched with the second standard information in the judging circuit so as to generate and maintain an on-state.
In this case, the trigger signal generating device can be used as the appliance is switched off by the transmission of the operation signal corresponding to the first standard information in a specific area from the wireless transmitter or the appliance is switched on by the transmission of the operation signal corresponding to the second standard information in a non-specific area. For example, when a cellular phone is employed as the appliance, the cellular phone is switched off compulsively (automatically).
Then, the embodiments will be described with reference to drawings. FIG. 1 shows a trigger signal generating device according to one embodiment. In FIG. 1 , an antenna 22 , a rectifier 21 and a starting circuit 10 constitute the trigger signal generating device, and an electric power controller 24 and an electrical appliance 23 constitute an object to be controlled in state shift by a trigger signal output by the trigger signal generating device. In this embodiment, the trigger signal is generated so as to switch on the power source of the electric appliance 23 via the electric power controller 24 . As the electric appliance 23 , a television set, a cellular phone and a wireless communication device for network can be exemplified. The trigger signal may be employed for another use except the switch-on operation as described above.
The antenna 22 receives an electromagnetic wave emitted from a wireless communication device (not shown) which belongs to the operational side and then, outputs an RF signal. The rectifier 21 rectifies the RF signal from the antenna 22 , and then, generates a rectified voltage (DC voltage). In this point of view, the rectifier 21 constitutes a voltage generator. Namely, the antenna 22 and the rectifier 21 constitute a power source to generate an electric power through the reception of the external energy. As shown in FIG. 1 , the rectifier 21 does not require the power source (as will described below, concretely). However, in order to define the standard voltage of the rectifier 21 , the ground of the rectifier 21 is connected with the starting circuit 10 . When the RF signal is not input into the rectifier 21 from the antenna 22 , the electric potential of the output terminal of the rectifier 21 is set equal to the electric potential of the power source terminal of the rectifier 21 . In this case, since the power source terminal is electrically grounded, the output terminal is also electrically grounded.
The starting circuit 10 outputs a trigger signal through the reception of the rectified voltage from the rectifier 21 . The trigger signal is supplied to the power source controller 24 so as to switch on the power source 23 on the basis of the supplied trigger signal.
The starting circuit 10 includes an electric current generator/electric current amplifier 11 , an electric current-voltage converter 12 and a battery power source 13 . The electric current generator is composed of an nMOS transistor M 1 so that the rectified voltage output from the rectifier 21 is applied between the drain/gate common connection and the source of the transistor M 1 on the basis of the ground voltage (standard voltage or second standard voltage), thereby generating an electric current at the electric current generator. The electric current amplifier is composed of an nMOS transistor M 2 , and pMOS transistors M 3 , M 4 so that the first current amplification can be carried out at the transistor M 1 and the transistor M 2 composing the first current mirror circuit CM 1 and the second current amplification can be carried out at the second current mirror circuit CM 1 composed of the transistors M 3 and M 4 .
The amplified current at the electric current generator/electric current amplifier 11 is output from the drain of the transistor M 4 and input into the electric current-voltage converter 12 so as to generate an electric voltage as a trigger signal on the basis of the amplitude of the current input into the converter 12 . The polarity of the output voltage may become positive or negative in dependence on the structure of the trigger signal generating device after the power source controller 24 . Herein, the connection from the electric current-voltage converter 12 to the ground is designated by the solid line. Then, the connection from the electric current-voltage converter 12 to the power source (second standard voltage or standard voltage) is designated by the broken line because the connection may be often omitted. The battery power source 13 functions as a power source of the starting circuit 10 while the battery power source 13 functions as power sources of the power source controller 24 and the electrical appliance 23 .
The starting circuit 10 consumes no electric power from the battery power source 13 under the condition that the rectified current is not input from the rectifier 21 , which is originated from that no electric current is flowed in the transistor M 1 under the condition of no rectified voltage so that no electric current is flowed in the current mirror circuits CM 1 and CM 2 , and in the electric current-voltage converter 12 because the current state of the converter 12 is stationed if the electric current-voltage converter 12 is composed of a CMOS circuit and the like. The power source controller 24 consumes no electric power from the battery power source 13 on the same reason as the starting circuit 10 . Namely, the power source controller 24 may be composed of a CMOS circuit and the like. The electric appliance 23 consumes some electric power from the battery source 13 when the electric appliance 23 is switched on by the trigger signal from the starting circuit 10 via the power source controller 24 . The electric appliance 23 consumes no electric current when the electric appliance 23 is switched off.
In this embodiment, since the potential difference V 1 between the rectifier 21 and the ground is set equal to the potential difference V 2 between the first current mirror circuit CM 1 and the ground, no electric current is flowed in the rectifier 21 and the first current mirror circuit CM 1 when the rectifier 21 and the first current mirror circuit CM 1 are switched off, so that the electric power consumption can be reduced effectively at standby state.
As a result, in FIG. 1 , the trigger signal generating device (the antenna 22 , the rectifier 21 and the starting circuit 10 ), the power source controller 24 and the electrical appliance 23 consume no current at standby state, which can exhibit an excellent advantage in view of electric power saving. The electric power consumption at the starting circuit 10 is performed when the antenna 22 receives the electromagnetic wave and the rectifier 21 generates the rectified current. When the electrical appliance 23 is switched on by the trigger signal, some electric power is consumed at the electrical appliance 23 . In such a case, however, when the antenna 23 receives no electromagnetic wave, the trigger signal generating device (the antenna 22 , the rectifier 21 and the starting circuit 10 ) and the power source controller 23 consume no electric current.
Not explained, a set/reset flip-flop (SR flip-flop) may be provided at the output of the electric current-voltage converter 12 so as to maintain the on-state of the electrical appliance 23 when the electromagnetic wave disappears so that no trigger signal is generated. Such a state-storing circuit as the SR flip-flop may be provided in the power source controller 23 or the electrical appliance 23 . In any case as exemplified above, if the SR flip-flop may be composed of a CMOS circuit, the SR flip-flop consumes no electric power at stationary state.
FIG. 2 shows input/output current characteristics of the current mirror circuits CM 1 and CM 2 in FIG. 1 . As shown in FIG. 2 , with each current mirror circuit, the output current Iout is generated in proportion to the input current Iin. In view of an integrated circuit, the proportional constant can be determined by adjusting the size ratio (gate ratio) of each MOS transistor. Namely, the proportional constant is defined as the size ratio of the MOS transistor.
According to the current amplification effect of the current mirror circuits CM 1 and CM 2 , the rectified voltage output from the rectifier 21 is converted into the corresponding current, which is amplified by the current mirror circuits CM 1 and CM 2 . The thus amplified current is converted into the corresponding voltage at the electric current-voltage converter 12 . In this way, the initial electric voltage from the rectifier 21 is converted into the corresponding amplified current. Therefore, since the rectified voltage is generated through the reception of the electromagnetic wave, the trigger signal generating device can generates a trigger signal strong enough to switch the state of the electrical appliance even though the intensity of the electromagnetic wave is weak (that is, weak electromagnetic wave). In other words, the distance between the electrical appliance and the wireless communication device (not shown) can be enlarged. If a plurality of current mirror circuits are connected in multistep, the amplification gain can be much enhanced.
According to the first current mirror circuit CM 1 which is located near the rectifier 31 , when the rectified voltage is beyond a predetermined voltage through the reception of too strong electromagnetic wave, the rectified voltage is reduced below the predetermined voltage. The reduction effect of the rectified voltage is originated from the reduction effect of the input impedance of the current mirror circuit. If the rectified voltage is reduced, the rectification effect of the rectifier 21 can be maintained high so as to reduce the electric power loss.
FIG. 3 shows the structure of the rectifier 21 of the trigger signal generating device as shown in FIG. 1 . The rectifier 21 is configured such that the nMOS transistor MR 1 is connected in series with then MOS transistor MR 2 and the gate of each transistor is short-circuited with the source of each transistor (namely, the transistors MR 1 and MR 2 constitute a sort of diode connection, respectively). Then, the intended RF signal is input in the rectifier 21 via the condenser C 1 . In this case, the RF signal is applied to the node located between the transistors MR 1 and MR 2 . Then, the smoothing condenser C 2 is provided is parallel with the transistors MR 1 and MR 2 so as to generate an output voltage (rectified voltage) between the drain of the transistor MR 1 and the source of the transistor MR 2 .
In the rectifier 21 shown in FIG. 3 , the electric current from the RF signal input therein is flowed subsequently in the transistor MR 1 , the condenser C 2 and the transistor MR 2 so as to generate a DC voltage (rectified voltage) at both sides of the condenser C 2 . In this case, the bottom terminal “DC−” is connected with the ground and the top terminal “DC+” is connected as the output terminal of the rectifier 21 with the starting circuit 10 .
In the trigger signal generating device shown in FIG. 1 , the first current mirror circuit CM 1 is composed of the nMOS transistors and is operated through the reception of the electric current. With the rectifier 21 to be connected with the first current mirror circuit CM 1 , therefore, the top terminal of the rectifier 21 functions as the output terminal of the rectified voltage as shown in FIG. 3 .
Contrary to the starting circuit 10 shown in FIG. 1 , the first current mirror circuit CM 1 may be composed of a pMOS transistor. In this case, with the rectifier 21 to be connected with the first current mirror circuit CM 1 , the bottom terminal (negative terminal) “DC−” functions as the output terminal of the rectifier voltage. The positive terminal “DC+” is connected with the VDD of the first current mirror circuit. In this case, the rectified voltage is applied to the first current mirror circuit CM 1 in the direction opposite to the direction of current flow from the current mirror circuit CM 1 . In this way, the current mirror circuit composed of the pMOS transistors can be operated. The rectifier 21 and the starting circuit 10 consume no electric power at standby state.
In the above case where the first current mirror circuit is composed of the pMOS transistor, the rectifier 21 and the structure around the current amplifier 11 can be configured as in FIG. 4 .
FIG. 5 shows the structure of the power source controller 24 shown in FIG. 1 . In this embodiment, the power source controller 24 is configured as an inverter (that is, CMOS inverter) composed of the pMOS transistor MS 1 and the nMOS transistor MS 2 . Since the power source controller 24 is configured as a CMOS circuit, the power source controller 24 consumes no electric power at standby state. The electrical appliance 23 to be connected with the power source controller 24 is configured so as to be switched on and off dependent on the voltage level of the output of the power source controller 24 .
FIG. 6 relates to a trigger signal generating device modified from the one in FIG. 6 . In this embodiment, the current generating circuit CM 1 ′ as shown in FIG. 7 is employed instead of the current mirror circuit CM 1 as shown in FIG. 1 . Like or corresponding components are designated by the same references.
In FIG. 6 , the rectifier 21 and the starting circuit 10 constitute the trigger signal generating device, and the electric power controller 24 and the electrical appliance 23 constitute an object to be controlled in state shift by a trigger signal output by the trigger signal generating device. In this embodiment, the trigger signal is generated so as to switch on the power source of the electric appliance 23 via the electric power controller 24 . As the electric appliance 23 , a television set, a cellular phone and a wireless communication device for network can be exemplified. The trigger signal may be employed for another use except the switch-on operation as described above.
The rectifier 21 rectifies the RF signal from the antenna 22 , and then, generates an rectified voltage (DC voltage). In this point of view, the rectifier 21 constitutes a voltage generator. The trigger signal is supplied to the power source controller 24 . The power source controller 24 switches on the electrical appliance 23 on the supplied trigger signal.
The starting circuit 10 includes the electric current generator/electric current amplifier 11 , the electric current-voltage converter 12 and the battery power source 13 . In the electric current generator/electric current amplifier 11 , the current generating circuit CM 1 ′ may be configured as shown in FIG. 7 , for example. The electric current generator is composed of an nMOS transistor MA 2 so that the rectified voltage output from the rectifier 21 is applied to the upper side of the capacitor CA 1 under the condition that the lower side of the capacitor CA 1 is electrically grounded (Namely, the electric potential of the lower side of the capacitor CA 1 is defined as a standard electric potential or second standard electric potential). In this case, a current is flowed in the electric current generator. The capacitor CA 2 is provided between the capacitor CA 1 and the gate of the nMOS transistor MA 2 so that a predetermined voltage is applied to the gate of the nMOS transistor MA 2 in accordance with the voltage to be applied to the capacitor CA 1 .
Then, the power source VA 1 is connected with the gate of the nMOS transistor MA 2 via the resistance RA 1 so that a predetermined voltage is applied between the gate and the source of the nMOS transistor MA 2 . The electric current amplifier is composed of an nMOS transistor MA 2 , and pMOS transistors M 3 , M 4 so that the first current amplification can be carried out at the transistor MA 2 and the second current amplification can be carried out at the second current mirror circuit CM 2 composed of the transistors M 3 and M 4 .
The amplified current at the electric current generator/electric current amplifier 11 is output from the drain of the transistor M 4 and input into the electric current-voltage converter 12 so as to generate an electric voltage on the basis of the amplitude of the current input into the converter 12 . The polarity of the output voltage may become positive or negative in dependence on the structure of the trigger signal generating device after the power source controller 24 . Herein, the connection from the electric current-voltage converter 12 to the ground is designated by the solid line. Then, the connection from the electric current-voltage converter 12 to the power source (second standard voltage or standard voltage) is designated by the broken line because the connection may be often omitted. The battery power source 13 functions as a power source of the starting circuit 10 while the battery power source 13 functions as power sources of the power source controller 24 and the electrical appliance 23 .
The starting circuit 10 consumes no electric power from the battery power source 13 under the condition that the rectified current is not input from the rectifier 21 , which is originated from that no electric current is flowed in the nMOS transistor MA 2 with no rectified voltage so that no electric current is flowed in the current mirror circuit CM 2 , and in the electric current-voltage converter 12 because the current state of the converter 12 is stationed if the electric current-voltage converter 12 is composed of a CMOS circuit and the like. The power source controller 24 consumes no electric power from the battery power source 13 on the same reason as the starting circuit 10 because the power source controller 24 may be composed of a CMOS circuit and the like. The electric appliance 23 consumes some electric power from the battery source 13 when the electric appliance 23 is switched on by the trigger signal from the starting circuit 10 via the power source controller 24 . The electric appliance 23 consumes no electric current when the electric appliance 23 is switched off.
In this embodiment, since the potential difference V 1 between the rectifier 21 and the ground is set equal to the potential difference V 2 between the output terminal of the current generating circuit CM 1 ′ and the ground, no current is flowed in the rectifier 21 and the current generating circuit when the rectifier 21 and the current generating circuit CM 1 ′ are switched off, so that the electric power consumption can be reduced effectively at standby state.
Then, the current generating circuit CM 1 ′ in FIG. 7 will be described. A predetermined voltage can be applied between the gate and source of the nMOS transistor MA 2 from the power source VA 1 . For example, when the voltage equal to the threshold voltage of the transistor MA 2 is applied, the transistor MA 2 does not conduct the amplification with no input signal, but the transistor MA 2 conduct the amplification to some degrees with input signal because the voltage applied to the transistor MA 2 is beyond the threshold value of the transistor MA 2 . Therefore, even though Therefore, even though the intensity of the input signal is low, the input signal is amplified by the transistor MA 2 .
The current generating circuit CM 1 ′ may be configured as shown in FIG. 8 . In order to apply a predetermined voltage between the gate and source of the nMOS transistor MA 2 , in this case, the nMOS transistor MA 3 with diode connection is provided between the current power source iA 1 connected with the VDD and the gate of the transistor MA 2 and the ground.
In this case, a predetermined current is supplied to the nMOS transistor MA 3 from the current power source IA 1 to generate a given voltage at the transistor MA 3 in dependence with the value of the current supplied thereto. The voltage generated at the transistor MA 3 is supplied between the gate and source of the transistor MA 2 . When the voltage generated at the transistor MA 3 is applied to the transistor MA 2 under the condition that the generated voltage is set equal to the threshold voltage of the transistor MA 2 , the transistor MA 2 does not conduct the amplification with no input signal, but the transistor MA 2 conduct the amplification to some degrees with input signal because the voltage applied to the transistor MA 2 is beyond the threshold value of the transistor MA 2 . Therefore, even though the intensity of the input signal is low, the input signal is amplified by the transistor MA 2 .
The current generating circuit CM 1 ′ may be configured as shown in FIG. 9 . In order to apply a predetermined voltage between the gate and source of the nMOS transistor MA 2 , in this case, the MOS transistors MA 3 and MA 4 are connected in series between the VDD and the ground so that the gate of the nMOS transistor MA 2 is connected with the node between the transistors MA 3 and MA 4 . In this embodiment, when an input signal is supplied to the transistor MA 4 , the transistor MA 4 is switched on, thereby supplying a current to the transistor MA 3 so that a predetermined voltage is applied between the gate and source of the transistor MA 2 from the transistor MA 3 .
When the voltage generated at the transistor MA 3 is applied to the transistor MA 2 under the condition that the generated voltage is set equal to the threshold voltage of the transistor MA 2 , the transistor MA 2 does not conduct the amplification with no input signal, but the transistor MA 2 conduct the amplification to some degrees with input signal because the voltage applied to the transistor MA 2 is beyond the threshold value of the transistor MA 2 . Therefore, even though the intensity of the input signal is low, the input signal is amplified by the transistor MA 2 .
The current generating circuit CM 1 ′ may be configured as shown in FIG. 10 . In order to apply a predetermined voltage between the gate and source of the nMOS transistor MA 2 , in this case, the MOS transistors MA 3 and MA 4 are connected in series so that an input signal is supplied to the source of the MOS transistor MA 4 and a predetermined voltage is supplied to the gate of the MOS transistor MA 4 from the VDD. As a result, the input signal is amplified at the transistor MA 4 and thus, a given current is supplied to the transistor MA 3 so as to generate a given voltage in dependence on the current supplied thereto. The voltage generated at the transistor MA 3 is applied between the gate and source of the transistor MA 2 .
When the voltage generated at the transistor MA 3 is applied to the transistor MA 2 under the condition that the generated voltage is set equal to the threshold voltage of the transistor MA 2 , the transistor MA 2 does not conduct the amplification with no input signal, but the transistor MA 2 conduct the amplification to some degrees with input signal because the voltage applied to the transistor MA 2 is beyond the threshold value of the transistor MA 2 . Therefore, even though the input signal is small, the input signal is amplified by the transistor MA 2 .
The trigger signal generating device shown in FIG. 6 consumes no electric current at standby, but generates a trigger signal when the signal detector 21 detects a signal, thereby switching on the electrical appliance 23 .
FIG. 11 relates to an embodiment modified from the embodiment relating to FIG. 1 . In this embodiment, the offset current compensating unit is provided. In FIG. 11 , like or corresponding components are designated by the same reference numerals in FIG. 1 .
The starting circuit 10 A includes the offset current compensating circuit 11 a in order to compensate the offset current (leak current) generated by the transistor M 2 provided at the output terminal of the first current mirror circuit CM 1 when no current is flowed in the transistor M 1 of the first current mirror circuit CM 1 . Although the offset current of the transistor M 2 is very small, the offset current often disturbs the normal operation of circuits provided after the current-voltage converter 12 without the offset current compensating circuit 11 a because the offset current is amplified.
The offset current compensating circuit 11 a includes the transistors M 5 , M 6 , M 7 and M 8 . The transistors M 5 and M 6 constitute a current mirror circuit configured in the same manner as the current mirror circuit CM 1 . The transistors M 7 and M 8 constitute a current mirror circuit configured in the same manner as the current mirror circuit CM 2 . Namely, the drain and the gate of the transistor M 5 corresponding to the transistor M 1 are connected with the ground. The connection state means that the rectified voltage is not input into the transistor M 1 . In this case, the electric current corresponding to the offset current generated by the transistor M 2 is generated at the transistor M 6 , and input into the transistor M 2 via the transistors M 7 and M 8 so that the electric current generated at the transistor M 3 can be compensated. In this way, the normal operation of the circuits after the second current mirror circuit CM 2 .
The size (gate width) of the transistor M 1 is set equal to the size of the transistor M 5 . The size (gate width) of the transistor M 2 is set equal to the size of the transistor M 6 . The sizes (gate widths) of the transistors M 3 , M 7 and M 8 are set equal to one another. However, each transistor may be set to any size only if the offset current of the transistor M 2 can be compensated by the transistor M 7 . In view of an integrated circuit, it is desired that the same size transistors are provided in the vicinity of one another so as to form the combination of the transistors.
Then, some components of the trigger signal generating device will be described. FIG. 12 shows the concrete structure of the current-voltage converter 12 in the above described embodiment relating to FIG. 1 . FIG. 12( a ) shows a simplest structure of the current-voltage converter 12 where the resistance RV 1 is provided between the input node and the ground. The intended output voltage can be obtained by the difference (the multiplication of the input current by the resistance RV 1 ) between the input voltage and the output voltage on the basis of the ground voltage. The current-voltage converter 12 consumes no electric current under the condition of no input current.
In FIG. 12( b ), the current-voltage converter 12 A is configured such that the current is input into the nMOS transistor V 1 with diode connection so as to generate the output voltage at the drain of the nMOS transistor MV 2 . The nMOS transistor MV 1 and the nMOS transistor MV 2 constitute the current mirror circuit. In this case, the resistance RV 2 is provided between the drain of the transistor MV 2 and the VDD (standard electric potential) so as to generate the output voltage. The polarity of the output voltage in the current-voltage converter 12 A in FIG. 12( b ) is opposite to the polarity of the output voltage in the current-voltage converter 12 A in FIG. 12( a ). The current-voltage converter 12 A consumes no electric current under the condition of no input current.
In FIG. 12( c ), the current-voltage converter 12 B includes the pMOS transistor MV 3 instead of the resistance RV 2 . In this case, the pMOS transistor MV 3 functions as an active load for the transistor MV 2 . The gate of the transistor MV 3 is fixed in electric potential (in this case, the ground potential). Since the resistance is not required, the layout area of the components such as transistors can be reduced. The current-voltage converter 12 B consumes no electric current under the condition of no input current.
In FIG. 12( d ), the current-voltage converter 12 C is configured such that the gate voltage of the transistor MV 3 is increased as the electric current to be input into the current-voltage converter 12 C is increased. The current is flowed into the resistance RV 3 via the nMOS transistor MV 4 and the PMOS transistors MV 5 and MV 6 so that the gate voltage of the transistor MV 3 can be increased. The nMOS transistor MV 4 and the transistor MV 1 constitute the current mirror circuit. The pMOS transistors MV 5 and MV 6 constitute the current mirror circuit located at the side of the VDD (second standard voltage). The resistance V 3 functions as a load for the transistor MV 6 .
FIG. 14 shows the current-voltage characteristic of the pMOS transistor MV 3 shown in FIG. 12( d ). In FIG. 14 , the reference character “Vgs-small” exhibits the current-voltage characteristic of the pMOS transistor MV 3 shown in FIG. 12( c ) and the reference character “Vgs-large” exhibits the current-voltage characteristic of the pMOS transistor MV 3 when the gate voltage of the transistor MV 3 is increased. In view of the physical property of a normal transistor, when the gate/source voltage Vgs is decreased, the drain current Id is decreased. Therefore, the direct-current resistance Vds/Id is increased. Namely, the transresistance of the current-voltage converter 12 C is increased when the input voltage is converted into the corresponding output voltage. Therefore, the output variation of the current-voltage converter shown in FIG. 12( d ) becomes larger than the output variation of the current-voltage converter shown in FIG. 12( c ). The current-voltage converter 12 C consumes no electric current under the condition of no input current.
In FIG. 12( e ), the current-voltage converter 12 D includes the nMOS transistor MV 7 instead of the resistance RV 3 . In this case, the nMOS transistor MV 7 functions as an active load for the transistor MV 6 . Since the resistance is not required, the layout area of the components such as transistors can be reduced. The current-voltage converter 12 D consumes no electric current under the condition of no input current.
In FIG. 12( f ), the current-voltage converter 12 E includes the nMOS transistor MV 8 with diode connection instead of the resistance RV 3 . In this case, the nMOS transistor MV 8 functions as an active load for the transistor MV 8 . Since the resistance is not required, the layout area of the components such as transistors can be reduced. The current-voltage converter 12 D consumes no electric current under the condition of no input current.
FIG. 13 shows the concrete structure of the current-voltage converter 12 . FIG. 13 relates to the total structure of the current-voltage converter 12 including the structure as shown in FIGS. 12( d ), 12 ( e ) and 12 ( f ). Like or corresponding components are designated by the same references.
In the current-voltage converter 12 shown in FIG. 13 , the current is flowed into the nMOS transistor MV 1 with diode connection so as to generate the output voltage at the drain of the nMOS transistor MV 2 . The transistors MV 1 and MV 2 constitute the current mirror circuit. The pMOS transistor MV 3 of which the source is connected with the VDD is provided between the VDD and the drain of the transistor MV 2 . The drain of the PMOS transistor MV 3 is connected with the drain of the transistor MV 2 so that the PMOS transistor MV 3 can function as an active load for the transistor MV 2 .
The variable power source Va 1 and the variable amplifier Aa 1 are connected in series with the input terminal so that the output of the variable amplifier Aa 1 is connected with the gate of the pMOS transistor MV 3 . The variable power source Va 1 varies the output voltage in accordance with the amplitude of the voltage generated at the nMOS transistor MV 1 . In the case that the output voltage from the variable power source Va 1 is increased, the gate voltage of the transistor MV 3 is increased so that the operational region of the transistor MV 3 is shifted from the linear region to the saturated region. In other words, the variable power source Va 1 varies the current-voltage characteristic of the transistor MV 3 .
When no signal is input for the input terminal, the electric potential of the variable power source Va 1 is set to the ground potential. Since the output voltage of the variable power source Va 1 is set to about zero volt, the absolute Value of the Vgs of the transistor MV 3 becomes large. In this case, the operation region of the transistor MV 3 is set to the linear region (corresponding to the linear region of the curve “Vgs-large” in FIG. 14 . Therefore, even though some noise signals are output from the transistor MV 2 , the corresponding noise signals are not generated at the transistor MV 3 because the impedance of the transistor MV 3 becomes low. The output voltage corresponds to the VDD (high state).
When a signal with an amplitude larger than the minimum input sensitivity of the variable power source Va 1 is input for the input terminal, a given voltage is generated at the input terminal so that the variable power source Va 1 generates the biasing voltage. In this case, the absolute Value of the Vgs of the transistor MV 3 becomes small so that the operational region of the transistor MV 3 is set to the saturated region (corresponding to the saturated region of the curve “Vgs-small”. Therefore, the impedance of the transistor MV 3 becomes large so that the output voltage of the output terminal becomes zero (ground potential). In this case, the output voltage corresponds to the low state.
The variable amplifier Aa 1 amplifies the output voltage of the variable power source Va 1 so that the variable range of the gate voltage of the transistor MV 3 can be enhanced, and thus, the variable load range of the transistor can be enhanced. Namely, the variable power source Va 1 and the variable amplifier Aa 1 , which are connected in series with one another, constitute the biasing voltage generating unit for the transistor MV 3 and can be defined as the non-linear component which can vary the output voltage remarkably in accordance with the voltage variation at the input side of the current-voltage converter 12 . It is desired that the variable amplifier Aa 1 is configured such that the gain of the amplifier Aa 1 becomes small when the voltage at the input side is small and the gain of the amplifier Aa 1 becomes large when the voltage at the input side is large.
According to the structure of the current-voltage converter 12 shown in FIG. 13 , the output voltage can be varied remarkably when the input current is beyond a predetermined threshold value. The current-voltage converter 12 F consumes no electric current under the condition of no input current. As described above, the variable amplifier Aa 1 and the variable power source Va 1 can be configured as in FIGS. 12( d ), 12 ( e ) and 12 ( f ).
Then, another embodiment will be described with reference to FIG. 15 . FIG. 15 shows a trigger signal generating device according to this embodiment. Like or corresponding components are designated by the same reference numerals, and thus, the explanation for the like or corresponding components will be omitted. In this embodiment, the signal detector 21 A is employed as the energy generator which generates electric power through the reception of external energy, instead of the rectifier 21 .
For example, the signal detector 21 A is composed of a rectification circuit using a diode and/or a MOS transistor or a photoelectric conversion element such as a photo voltaic power generating element using a PN semiconductor element. Namely, the signal detector 21 A includes at least an element which can generate a DC voltage in response to the input signal (e.g., optical signal) from an operational instrument (not shown).
In the case that the signal detector 21 A includes the photoelectric conversion element, if the photoelectric conversion element is formed as a Si-based PN junction element, the side of p-type semiconductor is connected with the ground potential and the side of n-type semiconductor is connected with the starting circuit 10 . Therefore, the side of n-type semiconductor is defined as the output of the signal detector 21 A. When an optical signal is input into the photoelectric conversion element, some electric charges are moved from the p-type semiconductor to the n-type semiconductor so as to increase the electric potential at the output on the basis of the photo-electric effect. According to the above-described operation, the input optical signal is detected so as to generate an electric voltage in accordance with the intensity of the input optical signal. When no optical signal is input, the electric charges are not moved because the photo-electric effect does not occur. Then, since the p-type semiconductor and the n-type semiconductor are connected with the ground (set to the ground potential), the signal detector 21 A consumes no electric power. As a result, the signal detector 21 A can be set as the standby state so as to receive the optical signal under the condition of no electric power consumption.
The starting circuit 10 is operated by the electric voltage generated by the signal detector 21 A in response to the optical signal input from an operational instrument (not shown), thereby outputting the trigger signal. When a signal train is generated by switching the optical signal, the starting circuit 10 can generate the corresponding signal data.
Then, still another embodiment will be described with reference to FIG. 16 . FIG. 16 shows a trigger signal generating device according to this embodiment. Like or corresponding components are designated by the same reference numerals, and thus, the explanation for the like or corresponding components will be omitted. In this embodiment, the battery power source 13 is electrically charged by the trigger signal.
In FIG. 16 , the electric power for the electrical appliance 23 A and the power source controller 24 A is supplied from the AC power source 25 , not the battery power source 13 . The electric power for the battery charger 26 is supplied from the AC power source 25 . When the trigger signal is input into the power source controller 24 A from the starting circuit 10 , the electrical appliance 23 A is switched on by the power source controller 24 and the battery charger 26 is switched on simultaneously. Then, the battery power source 13 is electrically charged by the battery charger 26 .
Namely, when the trigger signal is input into the power source controller 24 from the starting circuit 10 so as to switch on the power source controller 24 , the electrical appliance 23 A is operated by the output from the power source controller 24 A. Then, the battery charger 26 is operated by the output from the power source controller 24 A so as to generate a prescribed electric voltage to be applied to the positive electrode of the battery power source 13 . As a result, the battery power source 13 is charged to the prescribed electric voltage. Normally, the maximum charging voltage of the battery power source 13 is set to the prescribed voltage. The electric power for the electrical appliance 23 A, the power source 24 A and the battery charger 26 is supplied from the AC power source 25 (or an external DC power source) of which the output range is set larger than the output range of the battery power source 13 .
When the trigger signal is not output from the starting circuit 10 , that is, the starting circuit 10 is set off, the power source controller 24 A is set off so that the electric appliance 23 A and the battery charger 26 are set off. As a result, the electric power from the AC power source is not consumed.
In this embodiment, the battery power source 13 is electrically charged by the battery charger 26 when the electrical appliance 23 A is set on. As a result, the battery power source 13 is automatically charged when the electrical appliance 23 A is switched on, so that the exchange of the battery power source 13 due to battery exhaustion is not almost required.
Then, a further embodiment will be described with reference to FIG. 17 . FIG. 17 shows a trigger signal generating device according to this embodiment. Like or corresponding components are designated by the same reference numerals, and thus, the explanation for the like or corresponding components will be omitted. In this embodiment, the trigger signal generating device is configured such that an intended operation can be performed even though a plurality of electric appliances are provided in the elongated operational distance of the generating device.
In the trigger signal generating device according to this embodiment, the starting circuit 10 B includes the starting circuit-power source controlling circuit 31 , the synchronizing circuit 32 , the flip-flops 33 , 34 , 35 , the judging circuit 36 and the memory 27 .
The starting circuit-power source controlling circuit 31 is an electric power switch for controlling in on-off the power source of the starting circuit 10 B. In this case, the starting circuit-power source controlling circuit 31 is switched on by the trigger signal from the current-voltage converter 12 so as to switch on the power source of the starting circuit 10 B. Once the trigger signal is received, the state of switch on of the power source of the starting circuit 10 B can be maintained. When the starting circuit 10 B is switched on, the synchronizing circuit 32 , the flip-flops 33 , 34 , 35 , the judging circuit 36 and the memory 37 are operated. The electric consumption of the electric current generator/electric current amplifier 11 and the current-voltage converter 12 is already described above.
The synchronizing circuit 32 generates a clock signal with a given frequency and timing in response to the variation frequency of the output level of the current-voltage converter 12 . The clock signal may contain a PLL, for example. When the synchronizing circuit 32 is operated by the starting circuit-power source controlling circuit 31 , the output of the current-voltage converter 12 is varied at a given frequency in accordance with the preamble of a radio operating signal. Therefore, the synchronizing circuit 32 generates the clock signal in response to the frequency of the output of the current-voltage converter 12 . The clock signal is supplied at least to the flip-flops 33 , 34 , 35 .
The flip-flops 33 , 34 , 35 constitute the shift resistor. The shift operation of the shift resistor depends on the clock signal from the synchronizing circuit 32 . For example, when the flip-flops 33 , 34 , 35 are operated by the starting circuit-power source controlling circuit 31 , the output level (high state or low state) of the current-voltage converter 12 is varied in accordance with the ID information of the electrical appliance to be operated according to the ID information continued from the preamble of the radio operating signal. The thus obtained variation record is stored in the flip-flops 33 , 34 , 35 constituting the shift resistor, and transmitted to the judging circuit 36 .
The memory 37 stores in nonvolatility the ID information (standard information) of the electrical appliance 23 to be operated. For example, when the memory 37 is operated by the starting circuit-power source controlling circuit 31 , the ID information stored in the memory 37 is read out and transmitted to the judging circuit 36 .
The judging circuit 36 compares the ID information in the flip-flops 33 , 34 , 35 with the ID information in the memory 37 . When the ID information in the flip-flops 33 , 34 , 35 is matched with the ID information in the memory 37 , the judging circuit 36 outputs the result about the matching of ID information, which is supplied to the power source controller 24 . In order to maintain the judgment result by the judging circuit 36 , set/reset flip-flops (SR flip-flops) may be provided at the output of the judging circuit 36 . The SR flip-flops may be provided in the power source controller 24 or the electrical appliance 23 .
As described above, in this embodiment, the starting circuit-power source controlling circuit 31 , the synchronizing circuit 32 , the flip-flops 33 , 34 , 35 (shift resistor), the judging circuit 36 and the memory 37 are provided between the current-voltage converter 12 and the power source controller 24 as shown in FIG. 1 so as to confirm at least the ID information of the electrical appliance 23 . The number of flip-flop is not restricted to three as described in this embodiment, but may be set to any number in accordance with the amount of the ID information. For example, the number of flip-flop is set to four or more.
FIG. 18 shows the flowchart relating to the operation of the trigger signal generating device shown in FIG. 17 (at the state of switch on). According to the flowchart of FIG. 17 , the trigger signal generating device is set at standby state until the electromagnetic wave (radio operating signal) of which the intensity is beyond the detecting sensitivity of the device is received (Step 41 ). When the trigger signal generating device receives the radio operating wave, the received radio operating signal is converted into the corresponding electrical signal which is input into the starting circuit-power source controlling circuit 31 via the antenna 22 , rectifier 21 , the electric current generator/electric current amplifier 11 so as to switch on the starting circuit 10 B (Step 42 ). Therefore, the synchronizing circuit 32 and the like are operated.
Then, since the output voltage of the current-voltage converter 12 is varied in accordance with the preamble of the radio operating signal, the frequency of the synchronizing circuit 32 is set so as to be synchronized with the variation of frequency of the output voltage (Step 43 ). Then, since the output voltage of the current-voltage converter 12 is varied in accordance with the ID information continued from the preamble and the switching information (switching on) in the radio operating wave, the variation record of the output voltage is stored in the flip-flops 33 , 34 , 35 (shift resistor) (Step 44 ). Herein, the phrase “the ID information continued from the preamble and the switching information” is referred to the operation of switch on. The memory 37 stores the information corresponding to the ID information and the switching information.
The judging circuit 36 judges whether the information (one selected from among the variation record) stored in the shift resistor (flip-flops) is matched with the information stored in the memory 37 (Step 45 ). If not matched, the trigger signal generating device is set at standby state (designated “N” at Step 45 ). If matched, the power source controller 24 is operated by the output voltage from the starting circuit 10 B so as to switch on the electrical appliance 23 (Step 46 ). In this way, the operation of switch on of the electrical appliance 23 is finished. In this case, in view of electrical power saving, the power source of the starting circuit 10 B is switched off (Step 47 ). For example, the power source of the starting circuit 10 B is automatically switched off within a predetermined period of time which is managed in time by means of a timer (not shown). This operation can be applied for resetting the trigger signal generating device at standby state at Step 45 .
FIG. 19 shows the flowchart relating to the operation of the trigger signal generating device shown in FIG. 17 (at the state of switch off). Like or corresponding steps are designated by the same reference characters, and thus, the explanation for the like or corresponding steps will be omitted. In this flowchart, the process for switching off the electrical appliance 23 will be described in view of the electrical power saving after the electrical appliance 23 is switched on.
In the process, steps 41 to 43 are carried out in the same manner as in FIG. 18 . Then, since the output voltage of the current-voltage converter 12 is varied in accordance with the ID information continued from the preamble and the switching information (switching off) in the radio operating wave, the variation record of the output voltage is stored in the flip-flops 33 , 34 , 35 (shift resistor) (Step 54 ). Herein, the phrase “the ID information continued from the preamble and the switching information” is referred to the operation of switch off. The memory 37 stores the information corresponding to the ID information and the switching information.
The judging circuit 36 judges whether the information (one selected from among the variation record) stored in the shift resistor (flip-flops) is matched with the information stored in the memory 37 (Step 55 ). If not matched, the trigger signal generating device is set at standby state (designated “N” at Step 45 ). If matched, the power source controller 24 is operated by the output voltage from the starting circuit 10 B so as to switch off the electrical appliance 23 (Step 56 ). In this way, the operation of switch off of the electrical appliance 23 is finished. In this case, in view of electrical power saving, the power source of the starting circuit 10 B is switched off (Step 47 ) as shown in FIG. 18 . For example, the power source of the starting circuit 10 B is automatically switched off within a predetermined period of time which is managed in time by means of a timer (not shown). This operation can be applied for resetting the trigger signal generating device at standby state at Step 55 .
As shown in FIGS. 18 and 19 , when there are two information of “the ID information continued from the preamble and the switching information (switching on)” and “the ID information continued from the preamble and the switching information (switching off)”, if two sets of judging circuits 36 and the memories 37 are provided, the two information can be easily judged. If the starting circuit 10 B judges “the ID information continued from the preamble and the switching information (switching on)” and does not judges “the ID information continued from the preamble and the switching information (switching off)”, another power off function which can be remotely controlled may be provided for the electrical appliance 23 .
FIG. 20 shows the flowchart relating to the operation of the trigger signal generating device shown in FIG. 17 . In this case, the trigger signal generating device is kept to be switched on and then, the wireless operation to switch off the device is input. Like or corresponding steps are designated by the same reference characters, and thus, the explanation for the like or corresponding steps will be omitted. In this flowchart, the process relating to the flowchart shown in FIG. 18 is combined with the process relating to the flowchart in FIG. 19 . In the process relating to the flowchart shown in FIG. 18 , the starting circuit 10 B is not switched off after the electrical appliance 23 is switched on. Since it is considered that the electricity consumption of the starting circuit 10 B is relatively much smaller than the electricity consumption of the electrical appliance 23 after the electrical appliance 23 is switched on, such a condition as described above can be established on the switch on of the electrical appliance 23 .
An application of the trigger signal generating device shown in FIG. 17 will be described with reference to FIGS. 21 and 22 . FIG. 21 shows the structure of a cellular phone which uses the trigger signal generating device shown in FIG. 17 as application.
The cellular phone 70 includes the main body 230 , the antenna 231 , the battery power source 13 and the power source controlling circuit 100 equipped with the antenna 22 . The antenna 22 and the power source controlling circuit 100 can be configured in the same manner as shown in FIG. 17 . Herein, the output signal from the judging circuit 36 is input into the power source switch 101 . The power source switch 101 is located on the electric line from the battery power source 13 to the main body 230 of the cellular phone 70 . The power source switch 101 is switched on and off as occasion demands.
According to this embodiment, the main body 230 of the cellular phone 70 can be switched on and off through the reception of a radio operating signal at the antenna 22 . For example, as shown in FIG. 22 , the cellular phone 70 can be switched off compulsively and automatically through the reception of the radio operating signal from the base station 700 B for switching off the cellular phone in the area (e.g., music concert hall) which is considered as it is desired that the cellular phone 70 is switched off. The cellular phone 70 can be switched on automatically through the reception of the radio operating signal from the base station 700 A for switching on the cellular phone out of the area (e.g., music concert hall).
In the case that the operation of switch off of the cellular phone 70 is performed, if the user conducts the data transmission and reception or uses application(s), the cellular phone can be configured so as to recognize the user through the warning of switching off that the cellular phone will be switched off. In this case, the cellular phone can be also configured so as to be switched off under the condition that the cellular phone stores the setting condition and/or the using condition at present by the corresponding trigger signal. If the user switches on the cellular phone manually in the switching off-area as described above, the cellular phone can be configured so as to sound a warning to the user and then, to be switched off. Then, if the user comes in the switching on-area, the cellular phone can be configured so as to be switched on and then, reinstate the stored setting condition and/or the using condition. If the user does not desire to switch on the cellular phone 70 , the cellular phone can be configured so as not be automatically switched on by performing the mode setting in the cellular phone 70 in advance.
In this embodiment, the power source controlling circuit 100 is provided at the electrical line of the main body 230 of the cellular phone 70 , but another controlling circuit for remote-controlling the functional portion of the main body 230 of the cellular phone 70 such as a ring alert generating unit, a wireless communicating unit or a camera unit may be provided. For example, a cellular phone with a controlling circuit for controlling a wireless communicating unit is effective in a medical center. A cellular phone with a controlling circuit for controlling a camera unit is effective in a confidential information area.
Another application of the trigger signal generating device shown in FIG. 17 will be described with reference to FIG. 23 . FIG. 23 shows the structure of a wireless communication device (sensor network wireless communication node) which uses the trigger signal generating device shown in FIG. 17 as application.
The wireless communication device 71 includes the main body 230 A, the antenna 231 A, the battery power source 13 A, the power source controlling circuit 100 and the evocator 701 . The power source controlling circuit 100 can be configured in the same manner as shown in FIG. 17 . The power source switch 101 is located on the electric line from the battery power source 13 to the main body 230 A via the evocator 701 . The power source switch 101 is switched on and off as occasion demands. The antennas of the power source controlling circuit 100 and the evocator 701 are common with the antenna 231 A of the main body 230 A. The power source controlling circuit 100 is configured so as to output a given trigger signal as an indication signal to the evocator 701 .
According to this embodiment, the main body 230 A and the evocator 701 of the wireless communication device 71 can be switched on and off through the reception of a radio operating signal at the antenna 231 A. The evocator 701 is an electromagnetic wave-irradiating device which can irradiate the electromagnetic wave signal at the antenna 231 A. When the evocator 701 is switched on and receives an indication signal from the power source controlling circuit 100 , another wireless communication device, which is located apart from the wireless communication device as shown in FIG. 23 and configured in the same manner as in FIG. 23 , is switched on by the electromagnetic wave signal irradiated from the evocator 701 . In this way, a plurality of wireless communication devices, which are located apart from one another, can be subsequently switched on or off.
The wireless communication device in this embodiment is effective for the sensor network wireless communication node. With the sensor network wireless communication node, no electric power is supplied to the main body 230 A of the wireless communication device 71 through the control of the power source controlling circuit 100 under the condition that the communicating operation is not conducted so that the main body 230 A is rendered shutdown. In this case, the electricity consumption of the sensor network wireless communication node becomes almost zero. Namely, the electricity consumption of the sensor network wireless communication node can be maintained extremely low. When the communicating operation is conducted for the wireless communication node under the condition of extremely low electricity consumption, a wireless signal is supplied to the power source controlling circuit 100 so as to be switched on so that the wireless communication node can be switched on (operated). In this case, the wireless communication node can function as a normal sensor network device.
The evocator 701 can be configured so as to operate another wireless communication device instead of the wireless communication device 71 . For example, when the power source controlling circuit 100 receives an evocative indication from another wireless communication device, the power source controlling circuit 100 transmits the reception signal to the evocator 701 . The amplitude of the reception signal may be set larger than the amplitude of another signal to be transmitted at sensor network communication. If the above-described step is repeated, a plurality of wireless communication nodes, which are located apart from one another, are subsequently operated through the relay transmission of reception signal for the corresponding evocators. In the process, the main body 230 A not intended is not required to be operated so that the wireless communication network can be established while the total electricity consumption of the wireless communication network is maintained low.
The evocator 701 is composed of an oscillator with a frequency range adapted to the receiving band range of the power source controlling circuit 100 , a modulating device and an electric power amplifier. The antenna of the evocator 701 may be common with the antenna of the main body 230 A or the power source controlling circuit 100 . Alternately, the antenna of the evocator 701 may be provided independently.
Some embodiments are explained above. In this case, the rectifier 21 shown in FIGS. 1 , 6 and 17 may be configured as the one disclosed in JP-A 2006-34085 (KOKAI) and JP-A 2006-166415 (KOKAI). In this case, the electricity consumption of the rectifier at standby state may be increased to some degree, but the sensitivity of the rectifier is increased so that the electrical appliance, which is located much apart from the rectifier, can be operated.
Although the present invention was described in detail with reference to the above examples, this invention is not limited to the above disclosure and every kind of variation and modification may be made without departing from the scope of the present invention. Some featured components disclosed in the embodiments will be combined with one another. One or some components disclosed in the embodiments will be omitted.
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A trigger signal generating device includes a first power source terminal and a second power source terminal; a first current generator to generate a first current with a first amplitude in accordance with the amplitude of the input signal; a second current generator to generate a second current with a second amplitude, the second current being flowed from the first power source terminal to the second power source terminal; a current mirror circuit to amplify the second current generated from the second current generator to obtain an amplified current; and a trigger signal generator to convert the amplified current into a trigger signal used for triggering a trigger device, the voltage amplitude of the trigger signal being corresponding to the current amplitude of the amplified current; wherein both of the first and second current generators are connected to either one of the first and second power source terminals.
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BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a tunnel finisher of the type defined in the generic clause of patent claim 1.
Description of the Related Art
A tunnel finisher of this type is known from DE-PS 35 19 568. This tunnel finisher comprises pneumatic rollers each having a shaft composed of two sections releasably interconnected between the bottom- and top-side discs by means of a tubular connecting portion. The tubular connecting portion is axially displaceable for separating the connection between the upper shaft section carrying the top-side disc and fixedly retained in the housing, and the lower shaft section carrying the bottom-side disc and likewise fixedly retained in the housing. This separation permits the cylindrical envelope of the pneumatic roller extending between the discs to be replaced. There is the disadvantage, however, that replacement of the envelope is only possible with the pneumatic rollers mounted in the tunnel finisher. Since in this state the pneumatic roller is not readily accessible from all sides, the replacement of the envelope is a fastidious and time-consuming operation due to the compact construction of tunnel finishers. It is particularly difficult to raise the tubular connecting portion within the envelope for separating the shaft sections from one another and at the same time to remove the envelope downwards. Similar difficulties are encountered during the installation of a new envelope.
It is therefore an object of the invention to facilitate the replacement of the envelope of a pneumatic roller in a tunnel finisher of the type defined in the introduction.
SUMMARY OF THE INVENTION
According to the invention, this object is attained in a tunnel finisher of the type defined having the characteristic features as set forth in the characterizing clause of patent claim 1.
Since the shaft is provided with a releasable coupling between its upper section fixedly retained in the housing and its one-piece lower section carrying the discs, and since the one-piece lower section is tiltably supported on a tilt bearing, the pneumatic roller can be readily dismounted from the tunnel finisher by a simple operation. In the dismounted state, the pneumatic roller is readily accessible from all sides, to thereby permit the envelope to be readily and quickly replaced. It is particularly advantageous that only that part of the pneumatic roller has to be tilted or dismounted which is required for the replacement of the envelope. The upper shaft section and the drive transmission wheel mounted thereon thus remain in the tunnel finisher as the one-piece lower shaft section is being dismounted.
Another advantageous aspect of the tunnel finisher is set forth in claim 2. A Z-shaped joint is capable over extended periods of time to effectively transmit a drive torque, because the interengaged end portions of the upper and lower shaft sections are kept in surface contact with one another. The transmission of the driving torque is assisted in a particularly simple manner by a clamp sleeve covering the location of the joint. A coupling of this type is practically maintenance- and wear-free and permits the connection to be rapidly separated by releasing and axial displacement of the clamp sleeve, so that only very short downtimes of the tunnel finisher are required for replacing the envelope.
The characteristic according to claim 3 offers the advantage that a fastener extending longitudinally of the sheet material web greatly facilitates the replacement of the envelope on the lower section of the vertical shaft. This characteristic is thus effective to further reduce the time required for the replacement of the envelope.
Independent protection is claimed for this arrangement of the fastener, because this characteristic is useful independent of the remaining construction of a tunnel finisher.
The characteristic according to claim 4 is also useful, because a Velcro fastener is rather inexpensive and does not leave any impressions on the clothing pieces to be treated, particularly when it extends along a helical line as specified by claim 5.
The advantageous provision according to claim 6 permits the upper end of the envelope to be readily pulled off the upper end of the lower shaft section, or to be slipped thereonto, respectively, during replacement of the envelope. Additional fastener elements are not required.
The provision finally according to claim 7 enables the tension of the envelope to be advantageously readjusted when so required due to elongation of the envelope under the influence of the compessed air injected at its lower end.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention shall now be described by way of example with reference to the accompanying drawings, wherein:
FIG. 1 shows a perspective view depicting the general construction of a tunnel finisher,
FIG. 2 shows a front end view of the tunnel finisher with two pneumatic rollers disposed opposite one another,
FIG. 3 shows a sideview of pneumatic rollers similar to the ones shown in FIG. 2, with a different fastener arrangement, and
FIG. 4 shows a partially sectioned perspective view of the tunnel finisher during dismounting of a pneumatic roller.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Shown in FIG. 1 is a tunnel finisher 1 for the treatment of crumple-free finishing of clothing articles. Tunnel finisher 1 has a housing 2 defined by sidewalls 2a, 2b, a bottom wall 2c and a top wall 2d. Disposed in housing 2 are two chambers 3, 4 behind one another, the respective ends of which are defined by pairs of oppositely disposed pneumatic rollers 5a, b; 6a, b; 7a, b with vertically extending longitudinal axes, so as to define two substantially enclosed chambers. The pneumatic rollers are mounted at fixed locations in the housing at their ends, and adapted to be rotated by a drive mechanism 8. The pneumatic rollers 5a, 6a and 7a mounted adjacent sidewall 2a are thus rotatable in a counterclockwise direction while the pneumatic rollers 5b, 6b and 7b adjacent sidewall 2b are rotatable in the clockwise direction. Chamber 3 contains means for the steam treatment of a clothing article 9a from opposite sides, including a steam injector assembly 10 provided with steam nozzles (not shown) and connected to pipelines leading to a steam generator (not shown). Chamber 4 contains means for the subsequent drying and smoothing of the clothing articles, including a fan (not shown) operable to aspirate environmental air, to heat it, and to pass it through the chamber in the vertical direction.
The pneumatic rollers are shown in detail in FIGS. 2 and 3. Each pneumatic roller, for instance rollers 5a, 5b in FIG. 2, has a vertical shaft 11 with its upper end mounted in a bearing 12 secured to top wall 2d by means of a bearing support 13. The lower end of shaft 11 is supported in a tilt bearing 14 resting on a mounting plate 15. Shaft 11 is of two-piece construction including an upper section 11a mounted in bearing 12 and a lower section 11b supported in tilt bearing 14. Lower section 11b carries a top-side disc 16 adjacent its upper end, and a bottom-side disc 17 adjacent its lower end, disc 16 being releasably connected to shaft section 11b, while disc 17 is fixedly secured thereto. The cylindrical space extending between discs 16 and 17 is surrounded by an envelope 18 consisting of a flat sheet material web and provided with a fastener 19, preferably a Velcro fastener, extending vertically in die embodiment of FIG. 2, and along a helical line in the embodiment of FIG. 3. In the mounted state, envelope 18 has a circular hole 18a at its upper end, with an interior diameter slightly greater than the outer diameter of shaft 11, and at its lower end, an opening 18b having an inner diameter slightly greater than the outer diameter of bottom-side disc 17. The lower end of envelope 18 is sealingly secured to disc 17 by means of a clamp ring 20.
Bottom-side disc 17 is formed with a peripherally extending slot opening 21 communicating the interior of the pneumatic roller with the environment atmosphere (FIG. 3). Disposed below slot opening 21 and above tilt bearing 14 is a radially extending compressed air pipe 22 connected to a compressor (not shown) installed outside of housing 2. Compressed air pipe 22 is provied with nozzle-shaped openings 22a directed towards slot opening 21. As shown in FIG. 2, nozzle-shaped openings 22a enclose an angle of 90° between themselves to thereby ensure a uniform injection of compressed air into the pneumatic roller through slot opening 21.
The lower end of shaft 11 is formed to converge to a point. Complementary thereto, tilt bearing 14 is formed with a conical depression 14a, as a result of which the pneumatic roller automatically assumes its correct position in the tilt bearing and is safely retained thereat by its own weight.
Upper shaft section 11a has its upper end retained in bearing 12, its lower portion being supported by a mounting plate 23 fixedly secured to sidewalls 2a, 2b. A friction bearing 24 is disposed between upper shaft section 11a and mounting plate 23. Fixedly secured to upper shaft section 11a between bearings 12 and 24 is a drive transmission wheel 25, preferably in the form of a gear. The drive transmission wheels or gears 25 of the oppositely mounted pneumatic rollers of each pair are preferably dimensioned and arranged in such a manner that the two pneumatic rollers of each pair are rotatable by means of a common chain drive mechanism 26 disposed therebetween. The teeth of gears 25 are thus simultaneously engaged with chain drive mechanism 26. Chain mechanism 26 is surrouned on three sides by a casing rail 27 secured to mounting plate 23 and formed with longitudinally extending slots 27a at the locations of drive transmission gears 25 engaging chain mechanism 26. Secured to chain mechanism 26 at longitudinally spaced locations are downwardly projecting coat hooks 28 from which the clothing articles 9a, 9b are suspended by means of coat hangers 29 (FIG. 1). As shown in FIG. 1, chain mechanism 26 and casing rail 27 are disposed in the upper portion of housing 2 and extend in the longitudinal direction of tunnel finisher 1 through both chambers 3 and 4, to thereby enable clothing articles 9a, 9b to be conveyed through tunnel finisher 1.
Upper shaft section 11a is releasably connected to lower shaft section 11b by a coupling device 30. As shown in FIG. 2, coupling device 30 comprises a Z-shaped joint 31 and a clamp sleeve 32. To form Z-shaped joint 31, the lower end of upper shaft section 11a is formed with a recessed shoulder followed by an axially extending planar surface joining its free end face. The upper end of lower shaft section 11b is of complementary shape, the respective shoulders being of the same depth, so that in the joined state the two shaft sections present the appearance of a continuous shaft 11, with coupling device 30 ensuring effective transmission of the driving torque. This torque-transmitting connection is effectively secured by clamp sleeve 32 mounted for axial displacement on shaft 11.
For improved accessibility in the case of repair or maintenance operations on tunnel finisher 1, particularly for dismounting pneumatic rollers 6a, 6b, sidewall 2a or 2b is prpvided with a door 33.
Described in the following is the operation of the tunnel finisher described above, and the dismounting of a pneumatic roller.
To initiate the operation, the pneumatic rollers are supplied with compressed air via compressed air pipe 22 with its nozzle-shaped opening 22a and through slot openings 21 in bottom-side discs 17, to thereby cause envelopes 18 to be inflated to a cylindrical shape, so that the two pneumatic rollers of each pair come into contact with each other. The cloak hangers carrying clothing articles are suspended from coat hooks 28 and are then conveyed by chain mechanism 26 through the gap between the pneumatic rollers 5a, 5b of the first pair into first chamber 3 of the tunnel finisher. Since the envelope of each pneumatic roller yields to pressure, any creasing of the clothing articles is prevented. As soon as a clothing article has entered first chamber 3 by this continuous transport, steam injector assembly 10 is operated to inject steam onto the clothing article from at least two sides, causing the fabric to be relaxed. After the steam treatment of the clothing article 9b, the latter passes from first chamber 3 into second chamber 4, while a second clothing article 9a enters first chamber 3.
The above described process is repeated in first chamber 3, while the first clothing article 9b in second chamber 4 is treated with heated air supplied by the fan for drying and smoothing the fabric, so that the clothing article is free of creases after leaving second chamber 4.
The treatment carried out in second chamber 4 is then repeated for the second clothing article. The dwell times in the steam and hot air treatment chambers are variable by suitably controlling the chain speed. Since the compressed air-filled pneumatic rollers of each pair are in light contact with one another, each chamber is effectively isolated from the other one and from the surrounding atmosphere.
The replacement of the envelope of any pneumatic roller is suitably carried out after dismounting the respective roller from the tunnel finisher. The pneumatic rollers are accessible either from the front or from the rear of the housing, or through the door 33 provided in at least one sidewall. The dismounting operation is initiated by interrupting the supply of compessed air to the lower ends of the pneumatic rollers. Subsequently clamp sleeve 32 is unclamped on shaft 11 and pushed axially upwards onto upper section 11a to be clamped thereon. Shaft 11 may now be divided into the upper section 11a remaining in the tunnel finisher, and the lower section 11b to be dismounted therefrom. To this purpose lower section 11b is radially tilted to thereby disengage the recessed shoulders of the Z-shaped joint from one another. The lower section with the envelope to be replaced may then be lifted from its tilt bearing and removed from the respective chamber. The replacement of the envelope is initiated by releasing the clamp ring seated on the bottom-side disc. If the envelope is provided with a fastener, the latter is opened, so that the envelope can be readily pulled off over the top-side disc. Even if there is no such fastener, the envelope can be readily pulled off over the top-side disc, since the inner diameter of the cylindrical envelope is in any case greater than the outer diameter of the discs. The operations of fastening the new envelope on the lower shaft section and of remounting the pneumatic roller in the chamber are suitably carried out in the reverse sequence.
The invention is not limited to the embodiment described above by way of example. In the place of the axially displaceable clamp sleeve it is thus for instance possible to employ a divided clamp sleeve composed of two semi-circular sections. This would permit the height of the tunnel finisher to be reduced to smaller dimensions. The separable connection of the shaft sections could be accomplished by different coupling devices. The lower end of the upper shaft section might for instance be of quadrangular shape to be received in the upper end of the lower section. In this case, the clamp sleeve could be omitted, although the tilt bearing would have to be axially displaceable for separating the connection. The tilt bearing might also be formed with an upwards directed conical projection, in which case the lower end of the lower shaft section would have to be formed with a conical recess. It would also be possible to employ a zip-fastener instead of a Velcro fastener. The arrangement of the nozzle-shaped openings of the compressed air pipes may also be varied within a wide range, inasmuch as any position below the peripheral slot opening of the bottom-side disc may be suitable. Finally the envelope might also be secured to the top-side disc by means of a clamp ring. In this case, an envelope provided with a fastener would present the shape of a simple rectangular sheet.
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A tunnel finisher includes pneumatic rollers for defining an entrance and an exit for a pneumatic treatment chamber. The tunnel finisher is designed to facilitate the replacement of the envelope of pneumatic rollers.
The shaft of the pneumatic roller consists of an upper section fixedly mounted in the tunnel finisher housing, and a one-piece lower section carrying roller-supporting discs, with its upper end releasably coupled to the upper section, and its lower end tiltably supported on a tilt bearing.
The pneumatic rollers may thus be dismounted for simple and rapid replacement of the roller envelope, so that down-times of the tunnel finisher may be considerably reduced.
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RELATED APPLICATIONS
This application is a continuation-in-part of copending application Ser. No. 23,115, filed Mar. 23, 1979, now abandoned which is a continuation-in-part of Ser. No. 967,675, filed Dec. 8, 1978, now abandoned.
BACKGROUND OF THE INVENTION
The isolation and characterization of a peptide component of thymosin fraction 5 termed thymosin α 1 , was described in U.S. Pat. No. 4,079,127. Thymosin α 1 contained 28 amino acid residues and was an acidic peptide having a pl of about 4.0-4.3. It is further distinguished in having a blocked amino terminal (N-acetyl). Biologically thymosin α 1 is active in the MIF, E-rosette and mitogen assays but is not active in the mixed lymphocyte response (MLR) assay. The amino acid sequence for thymosin α 1 is as follows:
(N-acetyl)-Ser-Asp-Ala-Ala-Val 5 -Asp-Thr-Ser-Ser-Glu 10 -lle-Thr-Thr-Lys-Asp 15 Leu-Lys-Glu-Lys-Lys 20 -Glu-Val-Val-Glu-Glu 25 -Ala-Glu-Asn-OH
Goldstein et al., J. of Reticuloendothelial Society 23, 253 (1978) described partially purified thymosin β 3 and β 4 as components of thymosin fraction 5 and gross physical data is given. Additionally, Low and Goldstein in Year In Hematology 1978, Siber et al. ed. (Plenum Pub. Co. 1978) at p. 281 indicated that partially purified thymosin β 3 and β 4 induce TdT positive cells in T-cell populations.
The sequence for thymosin β 3 and β 4 advanced in the parent application, Ser. No. 967,675, has been revised in amino acids 24-35 by exchanging original sequence 30-35 for original sequence 24-29 of both peptides. This revision is based on additional data derived from thermolysin digests used in the peptide mapping.
DESCRIPTION OF THE INVENTION
The present invention relates to the isolation and chemical characterization of thymosin β 3 and β 4 , Thymosin β 3 has an isoelectric point of 5.2 and a molecular weight of 5,500. Thymosin β 4 has an isoelectric point of 5.1 and molecular weight of 4,982. They are the only two polypeptides isolated from fraction 5 thus far that can induce TdT positive cells. The induction of TdT by thymosin fraction 5 exhibits a bell shaped dose response curve. However, TdT response to thymosin β 3 and β 4 increases as the doses increase. The amino acid sequences for thymosin β 3 and β 4 are as follows:
Sequence of Thymosin β 3 ##STR1## -Lys-Phe-Asp-Lys-Ser 15 -Lys- -Leu-Lys-Lys-Thr 20 -Glu-Thr-Gln-Glu-Lys 25 -Asn-
-Pro-Leu-Pro-Ser 30 -Lys-Glu-Thr-Ile-Glu 35 -Gln-Glu-
-Lys-Gln-Ala 40 -Gly-Glu-Ser-(Asx, Glx, Ile,Thr)Ala-Lys-Thr-OH
Sequence of Thymosin β 4 ##STR2## -Lys-Phe-Asp-Lys-Ser 15 -Lys- -Leu-Lys-Lys-Thr 20 -Glu-Thr-Gln-Glu-Lys 25 -Asn
-Pro-Leu-Pro-Ser 30 -Lys-Glu-Thr-Ile-Glu 35 -Gln-Glu-
-Lys-Gln-Ala 40 -Gly-Glu-Ser-OH
Thymosin β 3 and β 4 were isolated from fraction 5A-PMSF by a combination of ion-exchange chromatography and gel filtration. Thymosin fraction 5A-PMSF was prepared according to the procedures as for thymosin fraction 5 (Hooper, et al., N.Y. Acad. Sci. 249, 125, 1975) with the following modifications. Protease inhibitor phenylmethylsulfonyl fluoride (PMSF) was added to the homogenizing media at a concentration of 0.1 mM. After the acetone precipitation, a 50-95% ammonium sulfate precipitation cut was made and was processed through ultrafiltration on DC-2 hollow fiber system and gel filtration on Sephadex G-25. The resulting protein peak was collected and was designated thymosin fraction 5A-PMSF. As summarized in FIG. 1, thymosin β 3 and β 4 were derived from thymosin fraction 5A-PMSF. Lyophilized thymosin fraction 5A-PMSF was chromatographed on a column packed with DEAE-cellulose in 10 mM Tris, 1 mM 2-mercaptoethanol, pH 8.5. Two stepwise linear gradients of 0-0.5 M NaCl and 0.5-1.0 M NaCl were used for the elution.
Thymosin β 3 was derived from the first retained peak and β 4 from the second retained peak of the DEAE-cellulose column. They were further purified by gel filtration on Sephadex G-75 in 6 M guanidine hydrochloride. The yield of thymosin β 3 from fraction 5 is about 1.7% and β 4 about 1.6%. Both preparations are free of carbohydrate and nucleotide.
Isoelectric focusing was conducted for 90 minutes using a constant power of 25 watts (LKB Model 2103 power supply). The gels were fixed in 20% trichloroacetic acid for one hour. They were stained in 0.1% Coomassie Blue in 20% trichloroacetic acid and destained in 10% trichloroacetic acid.
It should be noted that β 3 and β 4 failed to be stained with either isopropanol staining procedure as used for thymosin α 1 as set forth in U.S. Pat. No. 4,079,127 or the LKB procedure which uses sulfosalicylic acid, methanol and trichloroacetic acid in the staining solution.
For amino acid analysis, samples were hydrolyzed in 6 N HCl in evacuated sealed tubes for 24-120 hours at 110°. Amino acid analyzers used include a Beckman Model 119, a Beckman Model 121M, Beckman Model 119CL and a JEOL Model JLC-6AH. Thymosin β 3 and β 4 were also hydrolyzed with 3 N mercaptoethanesulfonic acid (Anal. Biochem. 60:45 (1974). Six normal hydrochloric acid containing 0.21 M dimethylsulfoxide (Anal. Biochem. 32:185 (1969)) was used for hydrolysis to determine content of cysteine or cystine.
Enzymatic digestion was performed in 1% ammonium bicarbonate at pH 8.3 for 2 to 3 hours at 37°. Trypsin or chymotrypsin were added to the protein solution for a final enzyme-substrate ratio of 1:50 (w/w). Cyanogen bromide cleavage was performed in 70% formic acid at room temperature for 4 hours. The ratio of cyanogen bromide to protein is 5:1 (w/w).
Cyanogen bromide was added in equal portions to the protein solution with stirring at intervals of one hour. At the end of four hours, the reaction product was diluted with five volumes of distilled water and lyophilized.
Partial acid hydrolysis was achieved in 0.03 M HCl at 110° for 4 to 16 hours in sealed evacuated tubes.
Separation of enzymatic digests or partial acid hydrolysis products of thymosin β 3 or β 4 was performed largely by paper electrophoresis and/or chromatography. In a two-dimensional separation, paper chromatography was carried out first, with n-butanol:glacial acetic acid:water=4:1:5 (v/v). This was followed by high-voltage electrophoresis at pH 1.9 for 30-50 minutes at 60 volts/cm. Peptides were detected with cadmium-ninhydrin reagent or with fluorescamine in acetone.
Separation of cyanogen bromide cleavage products was accomplished by gel filtration on Sephadex G-50 in 0.1 M NH 4 OH as shown in FIG. 2. Effluents were monitored by absorbance at 235 nm as well as by fluorescamine assay after alkaline hydrolysis as described by Nakai, et al. (Anal. Biochem. 58:563 (1974)). Peak 2 (CNBr fragment 1) was further purified by high-voltage paper electrophoresis at pH 1.9.
The amino acid sequence of the separated peptides were determined by Edman degradation procedures. The presence of amide groups on a peptide was deduced from the latter's mobility on high-voltage paper electrophoresis at pH 6.5.
Table 1 shows the amino acid composition of and the approximate molecular weight (MW) based on an approximate number of amino acid residues in thymosin β 3 . The molecular weight and number of amino acid residues in thymsin β 4 are based on the established amino acid sequence as shown on page 3. Thymosin β 3 and β 4 have very similar amino acid composition except that β 3 is larger and contains seven extra residues than β 4 .
TABLE 1______________________________________Amino Acid Composition of Thymosin β.sub.3 and β.sub.4Amino Acid β.sub.3 β.sub.4______________________________________Lysine 11.35(11) 8.71(9)Histidine 0.00(0) 0.00(0)Arginine 0.00(0) 0.00(0)Aspartic 4.91(5) 4.73(4)Threonine 4.68(5) 2.62(3)Serine 3.91(4) 3.73(4)Glutamic 13.70(14) 12.10(11)Proline 3.89(4) 4.85(3)Glycine 1.10(1) 1.35(1)Alanine 2.25(2) 2.30(2)Valine 0.00(0) 0.37(0)Methionine 0.52(1) 0.31(1)Isoleucine 2.35(2) 1.85(2)Leucine 2.58(3) 2.05(2)Tyrosine 0.00(0) 0.00(0)Phenylalanine 1.15(1) 0.85(1)Total 53 43MW 5,500 4,982pI 5.2 5.1Asp + Glu (%) 35.2 34.9______________________________________
Digestion of thymosin β 4 with trypsin produces 16 peptides. Table 2 lists their amino acid composition.
TABLE 2__________________________________________________________________________Amino Acid Composition of Tryptic Peptides of Thymosin β.sub.4Amino Acid T1 T1.2 T3 T4 T5 T6 6.1 8__________________________________________________________________________Lysine 2.14(2) 1.00(1) 1.26(1) 2.00(2) 1.86(2) 0.99(1) 0.97(1) 1.03(1)HistidineArginineAspartic acid 0.87(1) 0.61(1)Threonine 1.64(2) 0.95(1) 1.71(2) 0.86(1) 0.93(1)Serine 0.84(1) 1.31(1) 0.50 1.08(1)Glutamic acid 3.14(3) 2.42(2) 3.07(3) 2.03(2) 3.87(4)Proline 0.66(1) 0.72(1)Glycine 0.87(1) 0.57Alanine 0.46 0.30Valine 0.21MethionineIsoleucine 0.86(1)Leucine 0.84(1) 0.29 0.31TyrosinePhenylalanineTotal 3 1 3 7 9 6 7 7N terminal Leu Ser Lys Ser Thr═Ser Asx Glx(dansyl)__________________________________________________________________________Amino Acid T9 T9.1 T10 T11 T13 T14 T16__________________________________________________________________________Lysine 1.10(1) 0.96(1) 1.07(1) 1.01(1) 2.25(2) 1.10(1)HistidineArginineAspartic acid 1.07(1) 3.06(3) 0.97(1) 2.09(2) 1.17(1)ThreonineSerine 0.98(1) 0.85(1) 0.95(1) 0.97(1) 0.93(1)Glutamic acid 2.00(2) 2.18(2) 2.34(2) 0.76(1)Proline 1.85(2) 1.03(1) 1.10(1)Glycine 1.02(1) 0.75(1)Alanine 0.96(1) 0.80(1) 1.04(1) 0.24ValineMethionine 0.79(1)Isoleucine 1.09(1) 0.91(1)Leucine 0.79(1) 0.83(1)TyrosinePhenylalanine 0.91(1) 0.87(1) 0.87(1)Total 6 11 3 2 11 5 6N terminal Asx Phe Leu Glx(dansyl)__________________________________________________________________________
These peptides have been sequenced and the location of acids or amides assigned. These data, along with results obtained from cyanogen bromide cleavage of thymosin β 4 as well as partial acid hydrolysis of CNBr fragment 1, established the sequence of N-terminal 14-residue of thymosin β 4 as follows:
Blocked-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys
The N-terminal end of this 14-residue peptide as well as the intact thymosin β 4 are blocked. Other tryptic peptides isolated and sequenced are listed below:
T9: Asn-Pro-Leu-Pro-Ser-Lys
T4: Lys-Thr-Glu-Thr-Gln-Glu-Lys
T6: Thr-Glu-Thr-Gln-Glu-Lys
T8: Glu-Thr-Ile-Glu-Gln-Glu-Lys
T14: Gln-Ala-Gly-Glu-Ser
Tryptic peptide map of thymosin β 3 appeared very similar to that of thymosin β 4 . The only differences are that peptide T14 of β 4 was missing from the map of β 3 and an extra peptide was shown on β 3 map with the amino acid composition of (Asx, Thr 2 ,Ser,Glx 3 ,Gly,Ala 2 ,Ile,Lys).
Thus, it is seen that β 3 and β 4 have identical sequence at the N-terminal end of 43 residues and are differed at the C-terminal ends.
In order to completely elucidate the sequence of β 3 and β 4 , β 4 was digested with thermolysin and separated on a Bio-gel P-4 column in 0.1 M NH 4 OH. The separated pools were further fractionated on paper. Table 2a lists the amino acid composition of the isolated thermolysin peptides. These peptides were partially sequenced to provide overlaps for the tryptic peptides.
Additional tryptic digests of β 3 have provided the following peptides:
GR T 12 H Asx, Ser, Glx, Pro, Gly, Leu, Lys
GR T 13 H Glx, Gly, Ala
Further thermolysin digests of β 3 provided the following peptides:
GS 3H Asx, Thr, Ser, Glx 2 , Gly, Ala, Leu, Lys
GS 4G Leu(Lys, Lyd, Thr)
GS 8G Asx, Thr, Glx 3 , Lys
Based on GS 4G and GS 8G, peptide T 9 could be placed in the sequence at #30-35 while peptide T 6 is positioned in the sequence at #24-29. The full sequences for β 3 and β 4 reflect these assignments. Peptides GR T 12 H, GR T 13 H and GS 3H are believed to represent the C-terminal of β 3 .
TABLE 2a__________________________________________________________________________Amino Acid Composition of Thermolysin Peptides of Thymosin β.sub.4Amino Acid Th 1 Th 1 T 1 Th 1 T 2 Th 2 Th 2 T 1 Th 2 T 2 Th 2 T 3 Th 2 T 4 Th 2 T 5__________________________________________________________________________Lysine 2.04(2) 0.94(1) 1.00(1) 4.14(4) 2.12(2) 1.14(1) 0.98(1) 2.26(2) 1.01(1)HistidineArginineAspartic acid 0.97(1) 1.06(1) 1.03(1) 1.07(1) 1.10(1)Threonine 2.94(3) 2.00(2) 1.82(2)Serine 1.02(1) 0.96(1) 1.20(1) 0.98(1) 1.20(1)Glutamicacid 4.04(4) 3.17(3) 2.73(3)Proline 2.20(2) 1.45(2) 1.60(2)GlycineAlanineValineMethionineIsoleucineLeucine 2.02(2) 0.87(1) 0.89(1) 0.94(1) 0.71(1)TyrosinePhenylalanine 0.98(1) 0.93(1)Total 5 2 3 17 3 2 6 12 6N-terminal Phe Leu Asx(dansyl)__________________________________________________________________________ Amino Acid Th 2 T 6 Th 3 Th 5 Th 6 Th 9 Th 10__________________________________________________________________________ Lysine 0.85(1) 0.84(1) 0.90(1) 2.25(2) Histidine Arginine Aspartic acid 2.04(2) Threonine 0.91(1) Serine 0.97(1) 0.96(1) 1.02(1) Glutamic acid 1.09(1) 1.07(1) 4.10(5) 3.21(3) 1.31(1) 2.02(2) Proline 1.20(1) Glycine 1.12(1) 1.04(1) Alanine 1.02(1) 0.97(1) 1.03(1) Valine Methionine 0.56(1) Isoleucine 0.62(1) 0.62(1) 0.67(1) 0.86(1) Leucine Tyrosine Phenylalanine Total 2 4 10 5 3 11 N-terminal Ile (dansyl)__________________________________________________________________________
Partial acid hydrolysis of β 4 gave rise to several useful peptides for overlapping. The amino acid composition of these peptides are listed in Table 2b.
TABLE 2b__________________________________________________________________________Amino Acid Composition of Peptides Obtained by Partial and Hydrolysis ofThymosin β.sub.4Amino Acid P 1 P 1 T 1 P 1 T 2 P 1 T 3 P 1 T 5 P 2 P 3 P 4 P 8__________________________________________________________________________Lysine 5.01(5) 2.20(2) 2.04(2) 1.0(1) 2.10(2) 1.10(1) 1.07(1)HistidineArginineAspartic acid 1.00(1)Threonine 1.45(2) 1.68(2)Serine 1.26(1) 0.70(1) 1.00(1)Glutamic acid 2.81(3) 3.08(3) 2.02(2)Proline 0.70(1)GlycineAlanine 0.82(1)ValineMethionine 0.80(1)Isoleucine 1.02(1)Leucine 0.99(1) 0.91(1)TyrosinePhenylalanine 1.06(1)Total 12 7 3 1 3 2 1 1 7__________________________________________________________________________
Sequencer Run of Thymosin β 3
A sample of the cyanogen bromide (CNBr) clearage product of thymosin β 3 was applied to a sequencer (Beckman 890 c). The sample was precoupled with sulfophenylisothiocyanate (3-SPITC) in the reaction cup before the sequencer program was initiated. Beckman DMAA program (peptide program 102974) was used. The sequencer products were identified by high performance liquid chromatograph (HPLA) in a Hewlett Packard 1084B and/or analyzed by amino acid analysis after backhydrolysis with hydriodic acid. The results which are in total agreement with data obtained by manual sequence techniques are as follows:
Met-(ALA)-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-()-( )-Asx.
The first residue was not identifiable since the peptide was modified with 3-SPITC prior to the sequencer run. The overall sequencers for thymosin β 4 and β 3 are as follows:
Amino Acid Sequence of Thymosin Beta 4 ##STR3## -Lys-Phe-Asp-Lys-Ser 15 -Lys-Leu-Lys-Lys-Thr 20 -Glu-Thr-Gln-Glu-Lys 25 -Asn-Pro-Leu-Pro-Ser 30 -Lys-Glu-Thr-Ile-Glu 35 -Gln-Glu-Lys-Gln-Ala 40 -Gly-Glu-Ser-OH.
Amino Acid Sequence of Thymosin Beta 3 ##STR4## -Lys-Phe-Asp-Lys-Ser 15 -Lys-Leu-Lys-Lys-Thr 20 -Glu-Thr-Gln-Glu-Lys 25 -Asn-Pro-Leu-Pro-Ser 30 -Lys-Glu-Thr-Ile-Glu 35 -Gln-Glu-Lys-Gln-Ala 40 -Gly-Glu-Ser-(Asx, Glx 45 , Ile, Thr)Ala-Lys-Thr 50 -OH.
Although considerable research has dealt with the differentiation of immunologically mature T cells, few studies have addressed the control of differentiation of early T cells. The progression of T cell differentiation is thought to begin in the bone marrow. Further maturation then occurs in the thymus and terminally differentiated T cells localize in peripheral lymphoid tissues. This sequence of differentiation has been indicated primarily by ablation and reconstitution types of experiments, since specific markers for early thymocytes have been difficult to identify.
During the last few years, however, several studies have indicated that the enzyme terminal deoxynucleotidyl transferase (TdT) is uniquely associated with early T cell differentiation. In vitro, TdT polymerizes deoxynucleotides and although it requires a primer, it does not require a template. The function of the enzyme in vivo, however, is not known. TdT is found in the cortisone-sensitive, major thymus population, but not in immunologically committed, more mature T cells. Low levels of TdT are also found in bone marrow cells and this activity has been shown to be localized in a minor cell population separable by BSA gradient fractionation. This population of prothymocytes is Thy-1-negative, but can be induced in vitro to express Thy-1 by thymic hormones. In previous studies and in the results obtained herein the factors that control the differentiation of this prothymcyte population have been examined. The results demonstrate that the thymic hormone, β 3 and the related peptide β 4 induce TdT in an early prothymocyte population in bone marrow from athymic mice, demonstrating the thymic regulation of early prothymocyte differentiation in the bone marrow.
NIH Swiss nu/+, nu/nu and C57BL/6 specific pathogen-free mice used in the present experiments were obtained from the Frederick Cancer Research Center's Animal Production Area, Frederick, Maryland. Mice were 6 weeks old at the beginning of the experiments.
The method of Raidt et al., J. Exp. Med. 128, 681 (1968) was used to fractionate different cell suspensions from spleen, thymus, lymph nodes or bone marrow. Four layers of cells were formed at the interfaces of the discontinuous BSA gradient: Fraction A between 10% and 23% BSA; fraction B between 23-26%; fraction C between 26-29%; and fraction D between 29-33% BSA. BSA (Path-O-Cyte 5, lots 25 and 26) was obtained from Miles Research Products (Elkhart, Ind.). Fractionated cells were washed three times in Ham's F-12 medium.
The procedure for enzyme extraction has been described previously by Pazmino et al., J. Immunol. 119, 494 (1977).
The TdT assay was adapted from Kung et al, J. Exp. Med. 141, 855 (1975). One unit of enzyme activity was defined as the amount catalyzing the incorporation of 1 pmol of dGTP into acid insoluble material per hour. The specific activity was calculated from the total enzyme activity recovered from phosphocellulose per 10 8 nucleated viable cells.
Rabbit anti-Thy-1 serum was prepared by injecting 1×10 7 thymocytes from B6C3F 1 mice three times at weekly intervals. The rabbit was bled two weeks after the last injection. The serum was decomplemented and absorbed on B6C3F 1 liver cells twice and on NIH Swiss nu/nu spleen cells three times.
The indirect immunofluorescence method of Cerottini and Brunner, Immunology 13, 395 (1967) was used to determine the frequency of Thy-1-positive cells. BSA-fractionated bone marrow cells, which had or had not been incubated with thymosin (50 ng/ml) for two hours at 37° C., were incubated with rabbit anti-Thy-1 serum (1:200) at 37° C. for 30 minutes. The cells were centrifuged and washed three times in cold Ham's F-12 medium. The washed cells were suspended in 0.10 ml of a fivefold dilution of fluorescein-conjugated goat anti-rabbit IgG (Meloy Laboratories, Springfield, Va.) and incubated at room temperature for 30 minutes. The cells were washed twice with Ham's F-12 medium and resuspended in a drop of Bacto FA mounting fluid, pH 7.2 (Difco Laboratories, Detroit, Mich.). Smears of cells were made on the surface of microscope slides and then were examined by fluorescence microscopy.
Thymosin fraction 5 (Lot No. BPM390) and spleen fraction 5 (Lot No. 307), purified as previously described by Hooper et al. Ann. N.Y. Acad. Sci. 249, 175 (1975), were resuspended in saline solution at a concentration of 500 μg/ml.
Ten daily injections of 100 μg were given intraperitoneally to six-week-old NIH Swiss nu/nu, which were sacrificed 24 hours after the last injection. For the in vitro induction experiments, cells were washed three times after BSA gradient fractionation in Ham's F-12 medium containing 100 U/ml penicillin, 100 μg/ml streptomycin and 10 μg/ml gentomycin. After being washed, cell concentrations were adjusted to 1×10 8 cells/dish in 20 ml of Ham's F-12 medium containing antibiotics, 5% fetal bovine serum (Flow Laboratories, Rockville, Md.) and different concentrations of thymosin or spleen fraction 5 or of any of the different peptides isolated from thymosin. After incubation for various periods of time, cells were collected, washed twice with Ham's F-12 and extracted as previously described for TdT activity.
The following peptides, isolated from thymosin, were assayed for their ability to induce TdT in vitro: α 1 , β 1 , β 3 , β 4 , and synthetic α-1.
Actinomycin D at 0.5 μg/ml was incubated for 12 hours in the presence of thymosin with fraction B from the bone marrow of NIH Swiss nu/nu mice to study their effect on TdT induction. To follow the effect of Actinomycin D on RNA synthesis, cells were labeled with [ 3 H] uridine (10 μCi/ml) for the last 90 minutes of incubation.
In order to better assess the distribution of TdT in these tissues, thymus and bone marrow cell populations from NIH Swiss mice fractionated on discontinous BSA gradients were examined for TdT activity.
Thymosin activity was also tested by a in vivo TdT assay. Different doses of thymosin fraction 5 and other purified thymosin polypeptides were injected into hydrocortisone acetate treated C57BL/6J mice daily for 9 to 11 days. The animals were sacrificed, thymocytes prepared and TdT activity determined using the method described by Pazmino et al., J. Immunol. 119, 494 (1977). The ability of thymosin to induce the differentiation of pre-T cells to TdT positive thymocytes was demonstrated by the higher level of TdT activity, i.e., by increasing the number of TdT positive thymocytes. Table 2c gives the results of a typical TdT assay in vivo. One μg of β 3 is as active in inducing TdT in vivo as 100 μg of thymosin fraction 5.
TABLE 2c______________________________________In Vivo Induction of TdT in Thymocytes From HydrocortisoneAcetate Treated C57BL/6J MiceTreatment TdT Specific Activity*______________________________________Control saline 836.3Spleen fraction 5(100 μg/infection) 908.5Thymosin fraction 5(100 μg/infection) 2679.8Thymosin β.sub.3 (1 μg/infection) 2758.6Thymosin β.sub.3 (10 μg/infection) 2954.3______________________________________ *Values in p moles (.sup.3 HdGTP/30 min/10.sup.8 cells)
TABLE 3__________________________________________________________________________Distribution of TdT activity in fractionated tissues from NIH Swiss nu/+and nu/nu mice BSA fractions A B C D I II I II I II I II__________________________________________________________________________Thymus NIH nu/+ 185* 7 193 3 161 <0.1 <0.1 <0.1Bone marrow NIH nu/+ 145 <0.1 6 <0.1 1 <0.1 <0.1 <0.1Bone marrow NIH nu/nu 16 3 <0.1 1 1 <0.1 <0.1 <0.1__________________________________________________________________________ *Picomoles of dGTP incorporated/hour/10.sup.8 cells.
As illustrated in Table 3, TdT activity is evenly distributed in fractions A, B and C of BSA gradient fractionated thymocytes. These fractions contain 80% of the initial thymocytes. Using NIH Swiss thymocytes, only the peak I TdT activity was detectable, which is consistent with previous data demonstraing an age- and strain-dependent difference in peak II TdT expression. In contrast to thymocytes, however, fractionated bone marrow cells from NIH Swiss mice primarily had TdT activity associated with fraction A. Although this reaction constitutes only 5% of the total bone marrow, the specific activity of TdT in these cells was comparable to thymocytes suggesting that the majority of the cells in fraction A are TdT-positive. Also shown in Table 3 are the results obtained with bone marrow from NIH Swiss nu/nu mice. In contrast to the thymic-bearing NIH Swiss mice, only approximately 10% of the TdT activity was detectable. Comparable results (not shown) have been obtained with C57BL/6 mice in that TdT is found in the A, B, and C fractions of thymus cells, while only fraction A of bone marrow cells expresses TdT. Similarly, thymectomy of four-week-old C57BL/6 mice is followed by a rapid decrease of TdT-positive cells in the bone marrow. These results demonstrate that TdT is associated with most thymocyte subpopulations and a minor bone marrow population, presumably a prothymocyte population, and that the latter population may be under thymic regulation.
The restortation of various T cell fractions and the regulation of T cell differentiation of bone marrow cells have been shown to be influenced by thymic hormones. One such effect has been the ability of thymosin fraction 5 to induce the expression of theta in vivo. The BSA gradient fractions of bone marrow cells were therefore examined for the expression of theta and for their inducibility for theta expression. As shown in Table 4, the majority of bone marrow cells are theta-negative by immunofluorescence including the A fraction which is TdT-positive.
TABLE 4______________________________________Expression of Thy-1 in fractionated bone marrow cells fromC57BL/6 mice before and after in vitro incubation withthymosin fraction 5 Percent fluorescent cells* BSA fractions A B C D______________________________________Bone marrow before thymosin 3.5 2.5 1.3 2.5Bone marrow after thymosin 66.6 11.3 1.5 3.0______________________________________ *Thy-1-positive cells were determined by indirect immunofluorescence as described in the Materials and Methods.
These results demonstrate that TdT and theta antigen expression are independent and that TdT expression may precede theta expression in T cell differentiation. However, if fractionated bone marrow cells are incubated in vitro with thymosin fraction 5, the A fraction is inducible for theta expression. These results are consistent with previous studies suggesting that thymic hormones induce theta expression in TdT-positive bone marrow cells.
In order to next examine the effect of thymosin fraction 5 on TdT expression, NIH Swiss nu/nu mice were treated with thymosin fraction 5 and assayed fractionated bone marrow cells for TdT activity. As shown in Table 5, ten daily injections of 100 μg of thymosin fraction 5 increased TdT activity in the bone marrow fraction A to levels comparable to their heterozygous littermates.
TABLE 5______________________________________In vivo induction of TdT activity in bone marrow cells from nudemice with thymosin fraction 5* BSA fraction A B C D I II I II I II I II______________________________________Saline 22.sup.+ 4 9 1 <0.1 <0.1 <0.1 <0.1Spleen 18 <0.1 10 <0.1 3 <0.1 <0.1 <0.1fraction 5Thymosin 210 3 32 <0.1 3 <0.1 2 <0.1fraction 5______________________________________ *NIH Swiss nu/nu were given 10 daily injections of spleen fraction 5, thymosin fraction 5 or saline intraperitoneally. Twentyfour hours after the last injection, the mice were sacrificed and TdT was isolated as described in the Materials and Methods. .sup.+ Picomoles of dGTP incorporated/hour/10.sup.8 cells.
The induction is specific for thymosin fraction 5 in that neither saline nor spleen fraction 5 treatment had any effect. Interestingly, thymosin treatment of NIH Swiss nu/nu mice resulted in the appearance of peak I activity; however, when the same treatment is given to thymectomized C57BL/6 mice, both peaks I and II were induced to a specific activity comparable to that of the normal controls. No TdT activity was detected in fractionated cells from either the spleen or lymph nodes of thymosintreated mice. The results obtained after in vivo treatment with thymosin suggested that this hormone could promote TdT expression in bone marrow. However, it was not possible to differentiate between a direct inductive effect and a secondary effect on differentiation. Therefore the ability of thymosin fraction 5 to induce TdT in vitro in fractionated bone marrow and spleen cells from NIH Swiss nu/nu mice was examined. When fractionated spleen cells were treated with 25 ng/ml of thymosin fraction 5 for 18 hours, TdT was specifically induced in fraction B of bone marrow cells. Again, only peak I activity was induced. This time, however, the specific activity obtained was about 60% of the normal bone marrow fraction A population. Spleen fraction 5 had no inductive effect in vitro. These results, therefore, suggest a direct role of thymosin fraction 5 in the induction of TdT activity in the bone marrow cells from nu/nu mice.
The induction using 25 ng/ml in vitro is rapid such that within two hours a significant increase in TdT is evident. By four to six hours the cells are fully induced, and the enzyme activity remains constant up to 24 hours. The results obtained at 12 hours in the presence of 0.5 μg/ml of actinomycin D indicated that greater than 95% of the RNA synthesis is inhibited, as is the induction of TdT.
Since thymosin fraction 5 is a mixture of several different peptides, the ability of several purified peptides to induce TdT in vitro in BSA fraction B from the bone marrow was determined. As shown in Table 6, most of the peptides did not induce TdT. However, in the β group, β 4 was able to induce TdT to 30% of the thymosin fraction 5 level and β 3 had the highest activity and induced TdT to values close to 80% of that obtained with thymosin fraction 5.
TABLE 6______________________________________In vitro induction of TdT in fraction B bone marrow cellsfrom NIH Swiss nu/nu miceTreatment TdT specific activity*______________________________________Control saline 2.0Spleen fraction 5 1.0Thymosin fraction 5 214.0α-1 5.2β1 2.5β3 145.0β4 58.0Synthetic α-1 3.0______________________________________ *Values for peak I activity only (picomoles .sup.3 HdGTP/hour/10.sup.8 cells). Incubation was for 18 hours with 50 ng/ml of each peptide.
The concentration dependence for the induction of TdT in bone marrow fraction B cells by thymosin fraction 5, α 1 and β 3 is shown in FIG. 3. For thymosin fraction 5, concentrations as low as 3 ng/ml had a significant effect and approximately 30 ng/ml was optimal; however, at higher concentrations, there was a significant inhibitory effect, which was not associated with a loss of cell viability. In contrast, α 1 did not show any induction at concentrations ranging from 2 to 200 ng/ml. β 3 showed significant TdT induction at 1 ng/ml and the optimum was achieved at 10 ng/ml. In contrast to thymosin, however, no inhibition of induction was observed even at concentrations of 500 ng/ml. These results suggest that thymosin fraction 5 and β 3 specifically induce TdT in a manner comparable to the induction observed for other enzymes in response to specific hormones.
Thymosin β 3 and thymosin β 4 may be administered to warm blooded mammals by parenteral application either intravenously, subcutaneously or intramuscularly. The compounds are immunopotentiating agents with a daily dosage of β 3 in the range of about 1 μg/kg to 50 μg/kg and of β 4 in the range of about 30 μg/kg to 150 μg/kg of body weight per day for intravenous administration. Obviously the required dosage will vary with the particular condition being treated, the severity of the condition and the duration of the treatment. A suitable dosage form for pharmaceutical use is 4 mg of lyophilized thymosin β 3 or 12 mg of lyophilized thymosin β 4 per vial to be reconstituted prior to use by the addition of sterile water or saline.
Also included within the scope of the present invention are the pharmaceutically acceptable salts of thymosin β 3 and β 4 such as the alkali metal salts, e.g., the sodium or potassium salts, or the salts of strong organic bases such as guanidine. In addition, the counter ions of these cations as well as of lysine residues in thymosin β 3 or β 4 such as the hydrochloride, hydrobromide, sulfate, phosphate, maleate, acetate, citrate, benzoate, succinate, malate, ascorbate and the like, may be included in the preparation.
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Two related polypeptides, thymosin β 3 and thymosin β 4 , have been isolated from Thymosin fraction 5. These peptides have been characterized and sequenced. Thymosin β 3 has 50 amino acid residues while thymosin β 4 has 43 amino acid residues corresponding identically to the amino terminal 43 amino acids of thymosin β 3 . The compounds have useful biological activity as evidenced by their ability to induce terminal deoxynucleotidyl transferase (TdT) positive cells in T-cell populations. The invention described herein was made in part in the course of work under a grant or award from the Department of Health, Education and Welfare.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is based upon and claims the benefit of prior German Application No. 10 2014 005 524.8, filed on Apr. 15, 2014, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
The disclosure relates to a method for interrupting a current and, more particularly, a method, safety device, and associated device for interruption a current in an electrical arc.
BACKGROUND OF THE DISCLOSURE
In an electrical system of a vehicle with an operating voltage of 48V, for example, parallel electrical arcs may be created, which on the one hand limit the current in such a fashion that a melting fuse is not triggered, but on the other hand may cause a fire in the vehicle.
Furthermore, a cable break in the 48V electrical system may result in a serial electrical arc that cannot be protected by a melting fuse because the resulting current is less than the load current. This type of serial electrical arc can also cause a fire.
SUMMARY
One object of the present disclosure is to provide a solution for recognizing undesired states of an electrical system, in particular an electrical system of a vehicle.
This object is achieved according to the characteristics of the appended claims.
In accordance with the disclosure, there is provided a method for interrupting a current, wherein a signal of a supply line is integrated at least over a predetermined time period, and the current in the supply line is interrupted by means of a separating element if the signal that is integrated over at least the predetermined time period meets a predetermined condition.
In particular, a plurality of time periods, which may be different, can be integrated and evaluated in the scope of the predetermined condition.
The supply line signal can be a signal in the supply line or a signal that is determinable by means of the supply line. For example, it can be a current through a component that is connected to the supply line. It can also be a voltage drop at the component that is connected to the supply line.
In this context, it is an advantage that a precise signal determination (such as current determination) is possible per at least one time period, with the time period being designed flexibly. In particular, the at least one time period may be short compared to a time period in which a conventional (such as melting, for example) fuse would trigger. Another advantage is that a plurality of time periods can be determined and coupled with each other, for example to take into account a load characteristic of an electrical fault, such as an electrical arc, as precisely as possible. As a result, a conventional fuse with a predetermined triggering curve can therefore be upgraded with an active triggering curve that in particular takes into account time periods during which the energy detected in the fuse would not have been sufficient to trigger the fuse.
It is a development of the present disclosure that the current in the supply line is not interrupted, if the signal integrated over the at least one predetermined time period does not meet the predetermined condition, or if the signal integrated over the at least one predetermined time period meets another predetermined condition.
It is a further development of the present disclosure that the signal integrated over the at least one predetermined time period meets a predetermined condition if it reaches and/or exceeds a predetermined threshold value.
In particular, a plurality of threshold values may be provided, such as, for example, one each threshold value for each signal that is integrated over a predetermined time period.
In particular, it is a development of the present disclosure that the signal integrated over a predetermined time period is determined by averaging.
It is also a development of the present disclosure that the averaging is a squared averaging.
Furthermore, it is a development of the present disclosure that the signal is or comprises a current or a voltage.
In the scope of an additional development, the signal is a current through a fuse or a voltage drop at the fuse.
A further development is that the signal is a voltage drop at a fuse, with a resistance value of the fuse being determined at a temperature, and the resistance value and the voltage determining the current through the fuse.
In one embodiment, the signal is integrated by means of at least two integrators, with each of the integrators having its own integration time constant (meaning its own time period).
An alternate embodiment is that the predetermined condition is realized by means of a logical interconnection based on the results of the at least two integrators.
There are a plurality of potential logical interconnections. For example, the integrated signals may meet the predetermined condition if each signal is greater or equal to a threshold value (or a plurality of threshold values). For example, a logical AND-operation can be used for this purpose.
In some embodiments, the threshold value can take into account or depict a load characteristic of an electrical fault, such as a serial and/or a parallel electrical arc. In this way, the triggering curve of the fuse, which may be relatively slow, can be effectively and efficiently upgraded with a quick acting triggering curve. This results in a safety system that comprises the fuse as well as a detection unit with a separating element to detect electrical arcs, for example, and if an electrical arc is detected, the current relative to a load can be switched off.
In addition, it should be noted that the interruption of the current in the supply line can be temporary or permanent. In particular, an additional signalization can be performed, which indicates to a control device, for example, that an electrical arc has been detected. Optionally, the separating element could remain open until the fault can be corrected and/or a control device resets the circuit introduced here.
The explanations regarding the method also apply correspondingly to the other claim categories.
Also in accordance with the present disclosure, there is provided a device having a separating element, and a detection unit that is used to integrate a signal of a supply line over at least a predetermined time period. The detection unit is set up in such a fashion that a current in the supply line can be interrupted by means of the separating element if the signal integrated over at least a predetermined time period meets a predetermined condition.
It is a development of the present disclosure that the device comprises a fuse, with the signal being a current through the fuse, or a voltage drop at the fuse.
For example, the fuse may be a melting fuse in the current path of the supply line.
In some embodiments, the detection unit includes a differential amplifier, which is used to detect a voltage drop at the fuse, and an evaluation unit that compares the predetermined condition with the voltage drop at the fuse, and correspondingly triggers the separating element.
It is an additional development that the separating element is an electronic or a remotely activated switch.
Furthermore, a safety device comprising at least one of the devices described here is provided to attain the object of the present disclosure.
Said safety device can also be considered a safety system.
In the scope of a development of the present disclosure, the safety device can be used in an operating system, in particular a vehicle electrical system such as a 48V electrical system of a vehicle.
The solution presented here furthermore comprises a computer program product that can be loaded directly into a memory of a digital computer and comprises parts of program code that are suitable to perform the steps of the method described here.
In particular, the aforementioned detection unit and/or evaluation unit can be developed as a processor unit and/or a circuit arrangement that is at least partially firmly wired or logical, and is set up, for example, to execute the aforementioned process. Said detection unit and/or evaluation unit may be or comprise any type of processor or computer with the appropriate necessary peripheral devices (memory, input/output interfaces, input-output devices, etc.).
The above explanations relating to the method apply correspondingly to the device. The device may be executed in one component or distributed to a plurality of components.
The aforementioned properties, characteristics and advantages of this invention as well as the way in which they are achieved become clearer and more comprehensible in connection with the following schematic description of embodiments, which are explained in more detail in connection with the drawings. For the sake of clarity, the same or equally acting elements may have the same reference symbols.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram for the detection of a parallel electrical arc and for performing an appropriate action after the electrical arc is detected.
FIG. 2 shows an example of a timeline of a current in the case of the parallel electrical arc.
FIG. 3 is a diagram having a y-axis that shows a duration for a time period t RMS , during which a squared average (RMS) is formed, and the y-axis of said squared average having a current I(t) as a function of said time.
FIG. 4 shows a schematic diagram based on FIG. 1 in the case of a serial electrical arc.
FIG. 5 show a diagram with a plurality of time signal runs: a total current through the load, a voltage at the fuse, and a voltage at the load.
FIG. 6 shows the example of a circuit for the detection unit shown in FIG. 1 or FIG. 4 .
FIG. 7 shows an example of the mechanical integration of an analog filter.
DETAILED DESCRIPTION
The solution described here can be used for electrical systems, for example for electrical systems for vehicles, in particular for 48V electrical systems.
FIG. 1 shows a schematic diagram comprising a battery 101 , which in this example provides a voltage of about 48V relative to ground 102 . The positive pole of the battery 101 is coupled to the positive pole of a load 105 via a separating element 103 , a fuse 104 , and a supply line 110 . The negative pole of the battery 101 is coupled to the negative pole of the load 105 via a ground line 111 .
The load 105 may be any consumer circuit or any switching circuit, such as an operating device in a vehicle, for example.
A voltage drop at the fuse 104 is determined by a detection unit 107 in that one each terminal of the fuse 104 is connected to an input of a differential amplifier 108 . The output of the differential amplifier 108 is connected to an evaluation unit 109 , which, according to the output signal of the differential amplifier 108 , triggers the separating element 103 , e.g., opens or closes the separating element 103 .
The evaluation unit 109 and the differential amplifier 108 are examples of components of the detection unit 107 .
The detection unit 107 is therefore used to determine a voltage drop at the fuse 104 , and with said voltage drop an estimation is made as to a current through the fuse 104 , in particular a change of the current (dl/dt).
The evaluation unit 109 can be developed as a (micro) controller, a processor, or the like. Also, the evaluation unit 109 can be realized in form of an at least partially analog circuit (comprising an analog filter, for example).
The separating element 103 is a switch that can be electronically triggered, for example. For this purpose, a semiconductor switch, such as a transistor, MOSFET, JFET, IGBT, etc., and/or any other remotely activated switch (such as a relay) can be used.
FIG. 1 also shows the case of a fault in form of a parallel electrical arc 106 that forms between the supply line 110 and ground 102 (as a parallel short circuit). This type of intermittent electrical arc 106 limits the current through the fuse 104 in such a fashion that the energetic average is not sufficient for triggering the fuse 104 . Therefore, the electrical arc 106 remains unrecognized and may represent cause for a fire.
To prevent this, the voltage drop at the fuse 104 is supplied to the evaluation unit 109 , for example to an analog input of a microcontroller, via the differential amplifier 108 . In this way, the voltage drop at the fuse 104 can be measured and recorded continuously or at specific predetermined times, for example, by the evaluation unit 109 . For example, to that end, the evaluation unit 109 comprises an analogue-digital-converter that converts the signal provided by the differential amplifier 108 into digital values (samples) and then processes said digital values. In particular, a timeline of the digital values obtained in this manner, for example over a predetermined time period, can be taken into account to draw conclusions about a change in the voltage drop at the fuse 104 .
The temperature of the fuse 104 can be determined with a model of the fuse 104 or with a temperature sensor. The temperature is coupled to a resistance value of the fuse 104 , which, for example, can be determined by the evaluation unit 109 by means of stored data (for example in the form of a look-up table). With the (temperature-dependent) resistance value obtained in this manner, the current through the fuse can be determined using the known voltage drop at the fuse according to Ohm's Law (voltage drop divided by the resistance value).
The determined current can be averaged for at least one predetermined time period, for example. For example, time windows with durations of 0.1 ms, 1 ms, 10 ms can be used. In particular, averaging can be done by forming the squared average (also called RMS or QMW). In squared averaging, larger values have a greater influence than smaller values.
If multiple time periods are taken into account, the results of the averages determined for each time period can be coupled and the interconnection provides a signal that can be used to open the separating element 103 . The interconnection may be an AND-operation, for example. A comparison to a predetermined threshold value can also be made and used to determine an active triggering curve, e.g., a measurement for the opening of the separating element 103 .
FIG. 2 shows the example of a timeline of a current in the case of the parallel electrical arc. The parallel electrical arc causes irregular current peaks with high currents, some over 700 A. In the present case, said current peaks are too short for the energy they transmit to trigger the fuse 104 .
FIG. 3 shows a diagram where the y-axis shows a duration for a time period t RMS , during which a squared average (RMS) is formed, and where the x-axis shows a current I(t) as a function of said time.
A curve 303 represents a triggering curve of the fuse 104 . For example, the fuse 104 can trigger when a current of 100 A is permanently applied. However, if the current is applied for only a few milliseconds or a few tens of milliseconds, the fuse 104 will not trigger.
A curve 302 shows a load characteristic of the parallel electrical arc 106 , for example corresponding to the timeline shown in FIG. 2 . Because the time-dependent current I(t) of the electrical arc 106 does not reach the triggering curve of the fuse 104 (e.g. the curve 302 is positioned left of the curve 303 ), the electrical arc 106 does not lead to an activation and an interruption of the circuit by the fuse 104 .
By means of the detection unit 107 , the solution shown here facilitates that the triggering characteristic of the fuse 104 (curve 303 ) is upgraded with an active triggering characteristic according to a curve 304 , which in particular takes into account such time periods as are typical for an electrical arc, but are too short to trigger the fuse 104 . By means of the active triggering characteristic, the separating element 103 can already be opened and therefore the electrical arc 106 can be interrupted when the curve 304 is reached and/or exceeded (from left to right in FIG. 3 ). Because the curve 304 is near the curve 302 , i.e., near the load characteristic of the electrical arc 106 , the number of faulty triggers can be reduced and/or in particular minimized.
For example, the curve 304 can be realized in such a fashion that, for example, an associated current value 305 is predetermined for the time period t RMS =1 ms. Said current value 305 can be used for a first comparison of the output signal of the differential amplifier 108 . Optionally, a second comparison can be performed by specifying a second current value 306 based on the time period t RMS =0.1 ms. The first and the second comparison can be coupled in various ways to determine whether the separating element 103 should be opened. An example of the implemented interconnection is shown, for example, in FIG. 6 below.
Upgrading the triggering characteristic of the fuse 104 with the active triggering characteristic results in a maximum utilization range, as is shown by example left of a curve 301 .
FIG. 4 shows a schematic diagram similar to FIG. 1 . In this respect, reference is made to the explanations above. FIG. 4 differs to FIG. 1 in that it shows a serial electrical arc 401 in the supply line 110 . In addition, a capacity 402 is arranged parallel to the load 105 . Said capacity 402 can also be developed as part of the load 105 (for example, if the load 105 comprises a circuit with a capacitor that is arranged in parallel to said circuit). Preferably, the capacity 402 comprises at least one capacitor, with a capacitor value in the one-digit millifarad range and with a resistance of, for example, less than 20 mOhm being provided parallel to the load 105 . In particular, it is possible to customize the dimension of the capacity 402 for the specific user.
To ensure protection against this type of serial electrical arc 401 and the fire risk related thereto, the current through the fuse 104 is detected with the voltage drop at the fuse 104 , as described above in the case of the parallel electrical arc 106 .
The serial, intermittent electrical arc 401 briefly interrupts the connection to the load 105 , and the connection resumes after the interruption. Because the load 105 is supplied from the capacity 402 from the moment the load 105 is interrupted, the capacity 402 is discharged at least partially (or completely). As soon as the electrical arc resumes a conductive connection, large current peaks result to load the capacity 402 . Such current peaks can be used to detect the serial electrical arc 401 , as in the case of the parallel electrical arc 106 .
FIG. 5 shows a diagram with several time signal curves. A signal curve 501 shows a total current through the load 105 (and the fuse 104 ), a signal curve 502 shows a voltage at the fuse 104 , and a signal curve 503 shows a voltage at the load 105 .
In the example shown in FIG. 5 , the supply line 110 is interrupted at a point in time t 1 . The total current 501 and the voltage at the fuse 104 drop to 0; the voltage at the load 105 gradually drops to 0 because the load 105 is first supplied with the energy stored in the capacity 402 . From the point in time t 1 to a point in time t 2 , the intermittent serial electrical arc 401 interrupts the electric circuit. From the point in time t 2 on, the connection to the supply line 110 is temporarily restored; because of the previously discharged capacity 402 there will be high current peaks of the total current 501 , which are above the total current 501 in steady-state (in the present example, the current peaks are above 100 A and below −100 A, whereas in normal operation, the total current 501 is nearly constant at approximately 50 A). Correspondingly, the signal curve 502 results as voltage drop at the fuse. Said signal curve 502 can be evaluated so that the evaluation unit 109 can detect the serial electrical arc 401 and open the separating element 103 .
FIG. 6 shows an example of a circuit for the detection unit 107 . The voltage at the fuse 104 is determined by means of a differential amplifier 601 (which can correspond to the differential amplifier 108 mentioned above).
As explained above, current peaks during a parallel short circuit (caused by the parallel electrical arc 106 ) lead to a proportional voltage drop at the fuse 104 and/or current peaks result at the fuse 104 due to the charge of the capacity 402 parallel to the load 105 in the case of the serial electrical arc.
The output of the differential amplifier 601 is connected to the non-inverting input of an operational amplifier 602 and to the non-inverting input of an operational amplifier 603 . A capacitor C 1 is arranged between the inverting input of the operational amplifier 602 and its output, and a resistor R 1 is switched in parallel to said capacitor. The inverting input of the operational amplifier 602 is connected to ground via a resistor R 3 . A capacitor C 2 is arranged between the inverting input of the operational amplifier 603 and its output, and a resistor R 2 is switched in parallel to said capacitor. The inverting input of the operational amplifier 603 is connected to ground via a resistor R 4 .
The output of the operational amplifier 602 is connected to the first input of a comparator 604 . The output of the operational amplifier 603 is connected to the first input of a comparator 605 . The second input of the comparator 604 is connected to the second input of the comparator 605 , and is supplied with a reference voltage Uref via a node. The reference voltage Uref corresponds by example to the voltage that displaces the active triggering characteristic in the direction of the curve 304 .
The output of the comparator 604 is connected to the first input of an AND gate 606 and the output of the comparator 605 is connected to the second input of the AND gate 606 . The output of the AND gate 606 provides a signal 607 that indicates an electrical arc fault and with which the separating element 103 can be opened.
In the present example, according to FIG. 6 , the operational amplifiers 602 and 603 with respective wiring represent integrators that determine different time periods for the integration (integration time constants) as a function of the dimensioning of the wiring. The wiring of the operational amplifier 602 determines a time period T 1 according to
T1=2πR1C1,
and the wiring of the operational amplifier 603 determines a time period T 2 according to
T2=2πR2C2.
For example, the circuit can be designed for T 1 −1 ms and T 2 −10 ms.
At the output of each operational amplifier 602 and 603 , and for the time periods T 1 and/or T 2 , the voltage is proportional to an energy that was taken up by the fuse during that time period. The example lists two time periods T 1 and T 2 . A comparison to the reference voltage Uref is performed for each time period, with the signal 607 opening the separating element 103 only if the energy integrated in both of the two time periods T 1 and T 2 is already larger than a threshold value determined by a the reference voltage Uref.
As shown in FIG. 6 , the logical interconnection 608 of the output signals of the operational amplifiers 602 and 603 , resulting in the signal 607 , is one of many possible implementations. For example, other logical interconnections (such as different gates, for example) and/or multiple reference voltages may be provided. It is furthermore possible that only one single integrator or more than two integrators are provided.
One advantage of the solution presented here is that it is possible to determine a precise current value per at least one time period, with said time period optionally being designed flexibly. In particular, the at least one time period may be short compared to a time period in which a conventional fuse (such as a melting fuse, for example), would trigger. Another advantage is that multiple time periods can be predetermined and coupled, for example to take a load characteristic of a fault, such as an electrical arc into account as precisely as possible. As a result, a conventional fuse with a predetermined triggering curve can therefore be upgraded with an active triggering characteristic that in particular takes into account time periods during which the energy detected in the fuse is not sufficient for triggering the fuse.
FIG. 7 shows by way of example a mechanical integration of an analog filter 704 , such as according to the circuit shown in FIG. 6 , for example, for the detection of an electrical arc. FIG. 7 shows a fuse limiter 701 (such as 48V, for example) in a plan view 707 as well as a lateral view 702 , with the fuse limiter 701 being connected to the analog filter 704 via spacers 703 . Furthermore, FIG. 7 shows screw connections 705 .
By means of a connection line 706 , a plurality of the fuses with analog filter, as shown in FIG. 7 , can be connected in parallel.
Alternately, the analog filter 704 can also be inserted and/or fastened above the fuse limiter 701 .
Although the invention was illustrated and described in detail by the at least one embodiment, the invention is not limited to said embodiment and one skilled in the art may derive other variations within the protective scope of the invention.
LIST OF REFERENCE SYMBOLS
101 Battery
102 Ground
103 Separating element (such as an electronic switch or relay, for example)
104 Fuse (such as a melting fuse, for example)
105 Load
106 Parallel electrical arc
107 Detection unit
108 Differential amplifier
109 Evaluation unit
110 Supply line
111 Ground line
301 Curve (limit of the maximum usage range)
302 Curve (load characteristic of the electrical arc)
303 Triggering curve of the fuse 104
304 Active triggering curve
305 Current value
306 Current value
401 Serial electrical arc
402 Capacity (comprising at least one capacitor, for example)
501 Total current through the load 105 (and the fuse 104 )
502 Voltage at the fuse 104
503 Voltage at the load 105
601 Differential amplifier
602 , 603 Operational amplifier
604 , 605 Comparator
606 AND gate
607 Signal (Electrical arc fault)
608 Logical interconnection
R 1 , . . . , R 4 Resistance
C 1 , C 2 Capacitor
701 Fuse limiter
702 Lateral view
703 Spacer
704 Analog filter
705 Screw connection
706 Connecting line
707 Plan view
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A method for interrupting a current of an electrical power supply line includes integrating a supply line signal of the electrical power supply line over a predetermined time period to obtain an integrated signal, determining whether the integrated signal meets a predetermined condition, and using a current interrupting element to interrupt the current if the integrated signal meets the predetermined condition.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/592,567, filed Nov. 27, 2009 and issued a Notice of Allowance on Jul. 5, 2012, which further claims the benefit of U.S. Provisional Application No. 61/153,777 filed Feb. 19, 2009 and U.S. Provisional Application No. 61/156,565 filed Mar. 2, 3009, both of which are hereby incorporated by reference.
TECHNICAL FIELD
The present invention relates to a coupler for use with coiled optical fiber devices and, more particularly, to a device for adiabatic transformation of a propagating optical signal into a preferred modefield distribution for an optical signal propagating in an optical fiber coil.
BACKGROUND OF THE INVENTION
Optical pulse buffers are important for optical communications and ultra-fast computing. An exemplary preferred type of buffer, comprising an optical fiber coil, is disclosed in my co-pending US patent application [Sumetsky 13]. In this preferred buffer, the radii of the optical fiber and coil are selected to confine the propagating fundamental mode in a region that is shifted away from the center of the optical fiber, thus significantly reducing both propagation loss and bend loss along the device.
While the confinement of the propagating mode to a shifted, peripheral region of the optical fiber improves the performance of the device, difficulties remain in coupling an input signal to the optical fiber coil, or extracting an optical signal therefrom. One problem may be associated with the large mismatch between the coil and a conventional input/output waveguide or fiber in terms of, for example, physical dimension, modefield diameter and propagation constant.
There remains a need for providing low loss coupling from a conventional fiber (or, perhaps, a planar waveguide) into or out of the shifted fundamental mode of an optical signal propagating along an optical fiber coil.
SUMMARY OF THE INVENTION
The need remaining in the prior art is addressed by the present invention, which relates to an adiabatic optical coupler for use with coiled optical fiber devices and, more particularly, to an optical coupler for providing adiabatic transformation of an optical input signal propagating along the longitudinal axis of an incoming waveguide into a preferred off-axis (i.e., “shifted”) signal path along an optical fiber coil.
In accordance with the present invention, a section of optical fiber is utilized as an adiabatic optical coupler between a conventional input optical signal (propagating along an optical fiber or waveguide) and a coiled optical fiber device. The section of optical fiber may itself be coiled (or, at least, curved) to assist in transforming the conventional fundamental mode propagating along the longitudinal axis of the input fiber/waveguide to an off-axis fundamental mode that is shifted into a peripheral region of an associated coiled optical fiber device.
For embodiments where the adiabatic optical coupler is itself formed into a coil, the pitch of the coil can also be controlled to assist in the adiabatic transformation process.
In a preferred embodiment, the adiabatic optical fiber coupler remains physically separated from the turns of the associated coiled optical fiber device (as well as a central core rod, if included in the coiled optical fiber device) in order to ensure low loss transmission of the fundamental mode, without coupling any signal into the central core rod or individual turns of the coil.
Other embodiments and aspects of the present invention will become apparent during the course of the following discussion and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
So the manner in which the above-recited features of the present invention can be understood in detail, a more particular description of embodiments of the present invention, briefly summarized above, may be had by reference to embodiments that are illustrated in the appended drawings. It is to be noted, however, that the appending drawings illustrate only typical embodiments of the various embodiments encompassed within the scope of the present invention and, therefore, are not to be considered limiting, for the present invention may admit to other equally effective embodiments, wherein:
FIG. 1 illustrates an exemplary optical fiber coil optical device as fully described in co-pending application Ser. No. 12/587,767;
FIG. 2 illustrates an exemplary adiabatic tapered optical fiber coupler formed in accordance with the present invention;
FIG. 3 is a diagram illustrating the connections between an input optical signal path, an adiabatic coupler and an associated optical fiber coil;
FIG. 4 illustrates an exemplary coiled and tapered adiabatic optical fiber coupler formed in accordance with the present invention;
FIG. 5 shows the coupler of FIG. 4 in association with an input optical fiber;
FIG. 6 shows the coupler of FIG. 4 in association with an input optical waveguide;
FIG. 7 illustrates another embodiment of the present invention, utilizing an adiabatic optical fiber coupler formed as a coil having both a constant fiber radius and coil radius of curvature, using a variable pitch of the coil to provide the adiabatic transformation;
FIG. 8 ( a ) illustrates the conformal transformation of a curved optical fiber into a straight optical fiber;
FIG. 8( b ) shows the results of numerical simulation for a set of different transition lengths;
FIG. 9( a ) illustrates the conformal transformation of a coiled optical fiber into a straight optical fiber;
FIG. 9( b ) shows the propagation of the fundamental mode for a first taper length;
FIG. 9( c ) shows the propagation of the fundamental mode for a second, longer taper length;
FIG. 10( a ) illustrates a prior art configuration for coupling together two separate optical fiber coil devices; and
FIG. 10( b ) illustrates a coupling arrangement for interconnecting a pair of optical fiber coils in accordance with the present invention.
The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the term “may” is used in a permissive sense (i.e., meaning “having the potential to”), rather than the mandatory sense (i.e., meaning “must”). Similarly, the terms “include”, “including” and “includes” are considered to mean “including, but not limited to”. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures.
DETAILED DESCRIPTION
FIG. 1( a ) illustrates an exemplary optical fiber coil 1 as disclosed in my co-pending application. The propagating fundamental mode is shown in FIG. 1( b ) as being confined to an extreme outer peripheral region of each turn 2 of optical fiber along the coil. By confining the propagating mode to this region, the coupling between adjacent turns—as well as between the turns and a central core rod 3 —is significantly reduced, allowing for propagation with little or no scattering and/or bending losses.
While this configuration is considered a significant improvement over other types of optical delay devices, the ability to couple a propagating signal into or out of the desired extreme peripheral region of the fiber coil remains problematic. A suitable coupling arrangement needs to also address the physical size differences between standard input/output waveguides or fibers and the “micro” dimensions of an optical microfiber when using a microfiber to form coil 1 .
The present invention addresses these concerns, with FIG. 2 illustrating an exemplary adiabatic tapered optical fiber coil coupler 10 . As will be discussed in detail below, coupler 10 first couples a propagating optical signal from a single mode waveguide or fiber into a ‘straight’ section of optical microfiber. In an exemplary implementation of the present invention, an optical microfiber is used to form coupler 10 and is defined as a fiber having a diameter on the order of, for example, 5-100 μm, and may have no appreciable difference between the material or properties of a “core” region and a “cladding” region. The propagating optical signal thus continues to propagate along the longitudinal axis as it transfers from the single mode input signal path to the straight section of optical microfiber. A subsequent length of the microfiber is then outwardly tapered and curved (and, perhaps, coiled) to adiabatically transition the propagating signal into an off-axis signal that is shifted and confined to an extreme peripheral region of the microfiber coil. This specific configuration, utilizing an optical microfiber, is considered to be exemplary only, inasmuch as the principles of the present invention are equally applicable to arrangements using conventional fibers in the formation of a coiled device.
Referring to particular components in the embodiment of FIG. 2 , adiabatic coupler 10 is shown as including an input section 12 of optical fiber, which is coupled to an end termination of an input waveguide or fiber. At this point, input section 12 is shown as having (in this particular embodiment) a diameter of approximately one micron and supports a the propagating fundamental mode of an optical signal along its longitudinal axis. In accordance with the present invention, adiabatic coupler 10 further comprises an adiabatic transition section 14 formed of a curved section of optical fiber. In this instance, adiabatic transition region 14 is shown to have a radius of curvature R on the order of fifty microns. As further shown, adiabatic transition section 14 further exhibits an increase in fiber diameter d expanding outward from the one micron value at the interface with input section 12 to, in this case, a width of five microns. An output coupling section 16 , which comprises another section of optical fiber, is shown as disposed beyond adiabatic transition section 14 . In this embodiment, output coupling section 16 comprises an optical fiber of essentially constant diameter.
Also shown in FIG. 2 are diagrams of the modefield distributions at input location A and output location B of adiabatic coupler 10 . A circular modefield distribution is shown at the input (diagram A), with respect to the center of input section 12 of adiabatic coupler 10 . By the time the signal has propagated through adiabatic transition section 14 and entered output coupling section 16 , the modefield has shifted to an extreme peripheral portion of the (larger) optical fiber, now exhibiting a modefield distribution as shown in diagram B. Comparing this modefield distribution to that associated with the optical fiber coil of FIG. 1( b ), it is clear that adiabatic optical coupler 10 of the present invention is capable of forming an input signal that can be coupled into an optical fiber coil with little, if any, loss.
FIG. 3 is a diagram illustrating the connections between an input optical signal path, adiabatic coupler 10 and optical fiber coil 1 . As described above and further discussed below, the input optical signal path may comprise an input optical fiber, shown as optical fiber 13 in FIG. 3 , or a planar optical waveguide, shown as waveguide 15 in FIG. 3 , or any other suitable mode of providing single mode optical signal propagation. It is an aspect of the coupler configuration of the present invention that coupler 10 should not come into contact with core rod 3 of optical fiber coil 1 until the mode has shifted to the outer peripheral region of the microfiber—as shown in diagram B of FIG. 2 . Otherwise, contact between coupler 10 and core rod 3 will result in the unwanted coupling of a portion of the propagating signal into core rod 3 .
Also shown in FIG. 3 is the evolution of the transverse eigenvalues of the propagating modes along the length of adiabatic coupler 10 . The diagram associated with input section 12 of coupler 10 illustrates only the fundamental mode as being supported along the optical fiber. The dark line represents the effective index of the propagating mode relative to the index profile of the optical fiber. As is well known in the art, the profile is tilted to represent the influence of bending on the waveguiding properties of the optical fiber. As the optical fiber becomes larger in diameter, additional modes appear, as shown in the diagram associated with adiabatic transition section 14 . The inclusion of the curvature in conjunction with the larger diameter allows for the fundamental mode (shown as the darker line in the diagrams) to be retained; that is, an adiabatic (mode-preserving) transition occurs. Further increase of the fiber diameter introduces more modes at output coupling section 16 , while still retaining the adiabatic transition of the fundamental mode. It is to be noted that at output coupling section 16 , the mode represented by the dark line is displaced relative to the center of the waveguide. In accordance with the present invention, output coupling section 16 of adiabatic coupler 10 is then directly connected to optical fiber coil 1 (using a fused fiber technique, for example) to form the final structure.
In accordance with the present invention, therefore, an incoming single mode signal is first coupled into an optical fiber in a manner which maintains the distribution of the fundamental mode about the longitudinal axis of the waveguide. An adiabatic transformation is then performed to shift this signal off-axis to an outer peripheral region of the optical fiber. This transformation is provided in an adiabatic manner to maintain the propagation of the fundamental mode of the signal.
It is to be understood that while the concepts of the present invention have been described up to this point in the form of an “input” coupler, the same principles may be applied to form an “output” coupler, which is connected to the output of exemplary optical fiber coil 1 . In this case, an output coupler would first transition the output signal propagating along an outer peripheral region of the fiber back towards the longitudinal axis of an output waveguide through an adiabatic transition region that retains the fundamental mode.
FIG. 4 illustrates an alternative adiabatic coupler 20 formed in accordance with the present invention. In this example, adiabatic coupler 20 includes an input coupling section 22 , again comprising a section of optical fiber having a diameter on the order of one micron. As with the embodiment discussed above, input coupling region 22 is used to couple a propagating single mode optical signal (from an optical fiber or planar waveguide, for example) into the coupler. An adiabatic transition section 24 is then formed of a section of optical fiber (in this particular example, an optical microfiber) which expands in diameter from about one micron to about five microns, where in this case the optical fiber is coiled in the manner shown in FIG. 4 . By decreasing the spacing between adjacent turns in the coil forming adiabatic transition section 24 , the propagating optical signal is shifted to the desired outer peripheral region of the optical fiber (see diagram B in FIG. 2 ). This configuration is defined as exhibiting a variable coil “pitch”, where the pitch defines the spacing between adjacent turns of a coil, examples being P and P 2 in FIG. 4 . An output coupling section 26 , having the same dimensions as an associated optical fiber coil (not shown), is then used to ultimately couple the propagating signal into the optical fiber coil.
FIG. 5 illustrates adiabatic coupler 20 as used in conjunction with input optical fiber 13 . Also shown in FIG. 5 is the incoming, circular fundamental mode of the propagating signal at the junction between optical fiber 13 and input coupling section 22 of adiabatic coupler 20 (diagram A). The shifted output from coupler 20 , appearing along output coupling section 26 , is shown in diagram B in FIG. 5 . FIG. 6 is a similar arrangement, in this case coupling planar waveguide 15 to adiabatic coupler 20 .
FIG. 7 shows yet another embodiment of the present invention, where in this case an adiabatic coupler 30 comprises a section of optical fiber with a constant diameter—in contrast to the use of tapered fibers in the embodiments discussed above. As shown, coupler 30 includes an input coupling section 32 of optical fiber, followed by an adiabatic transition section formed as a coil, with an ever-decreasing pitch between adjacent coils. A bend-induced adiabatic transition causes the propagating fundamental mode to shift from its initial propagation along the longitudinal axis of the fiber to an off-axis position, as shown along output coupler section 36 . Without the use of a tapered fiber, however, a longer length of optical fiber (compared to coupler 20 ) is required to form the adiabatic transition section. However, in systems where the formation of optical fiber tapers, particularly in microfiber, is problematic, the embodiment of FIG. 7 may be preferred.
In each of these embodiments, the fundamental mode is propagating along longitudinal axis of the optical signal path prior to transformation. This is considered to be an important aspect of the adiabatic coupler of the present invention, since transformation of this signal to an off-axis, shifted location is more compact than prior art arrangements which first require coupling the signal out of a single mode fiber. The adiabatic coupler of the present invention can be accomplished with higher extinction, coupling less power into unwanted modes of the microfiber than prior art couplers. Further, prior arrangements did not take advantage of the benefit of controlling the spatial location of the shifted mode to reduce overlap with the central rod or glass surface of the microfiber (reducing loss).
As an example, consider a curved adiabatic coupler, such as coupler 10 , with constant radius r and bend radius R(z) which is changing from a very large value R 0 at z=0 (corresponding to the optical fiber input coupling section) to the coil radius R according to the law
R ( z ) = 2 ( R 0 - R ) exp ( z 2 / L 2 ) + 1 + R .
Here, L is the characteristic length of the transition region. Bending is modeled with a vector beam propagation model (RPM) by introduction of a local effective index variation corresponding to the local optical fiber curvature, as shown in FIG. 8( a ), which illustrates the conformal transformation of a curved optical fiber into a straight optical fiber. In this example, the fiber radius is set to r=10 μm and the final coil radius is set to R=1 mm. FIG. 8( b ) shows the results of numerical simulation (surface plots) for the transition lengths L=1, 2, and 6 mm. In surface plot 1 , L=1 mm and the launched fundamental mode of a straight microfiber experiences non-adiabatic transformation, which causes excitation of at least two modes, E 00 and E 01 . Interference of these modes shows up in oscillations of the field amplitude in the region of the coiled microfiber. The period of these oscillations can be found from the following equation:
Δ z = 2 1 3 ( t 1 - t 0 ) - 1 ( 2 π R ) 2 / 3 ( λ / n f ) 1 / 3 = 245.1 μm .
This value is in agreement with the period Δz≈245 μm found from the surface plot 1 of FIG. 8( b ). In surface plot 2 , L=2 mm and the transition region is still non-adiabatic, as indicated by oscillation of the field in the region of the coiled optical fiber. The period of oscillations found from surface plot 2 , Δz≈245 μm, is again in excellent agreement with the prediction from the above equation. Finally, in surface plot 3 , which corresponds to the transition length L=6 mm, no field oscillations are observed and the launched axially symmetric fundamental mode is adiabatically transformed into the shifted fundamental mode of the coiled microfiber. The total length of this adiabatically bent optical fiber is less than 10 mm, i.e., it does not exceed the length of two turns of an optical fiber coil with 1 mm radius of curvature.
Adiabatic propagation along the fundamental mode of a coiled adiabatic coupler, such as coupler 20 , is performed with exponentially small losses if the characteristic taper length, L t , satisfies the adiabatic condition L 1 >>1/(β 1 −β 0 ), where β 1 −β 0 is the smallest separation between the propagation constant of the fundamental mode, β 0 , and β 1 is the propagation constant of the next-highest mode that is excited by the introduced deformation. For a coiled optical fiber taper with monotonically decreasing separation of propagation constants, the adiabatic condition can be derived from the following:
L
i
>>
1
min
(
1.3
β
1
3
R
-
2
3
,
(
Rr
)
-
1
2
)
.
As an example, consider transformation of the fundamental mode of a single-mode optical fiber into the shifted mode of an optical fiber coil which has the parameters: R=2.5 mm, r=15 μm, λ=1.5 μm, and n f =1.5. Then, the above relation yields L 1 >>0.2 mm. The numerical simulation shown in FIG. 9 confirms that the requested transformation becomes low loss at L t ˜1 mm. Modeling of the bent optical fiber taper was performed with the vector BPM and conformal transformation, where a bend taper with refractive index n f was replaced by a straight taper with the effective refractive index n f (1+x/R), as illustrated in FIG. 9( a ). The taper radius variation was chosen in the form r(s)=r 0 +(r−r 0 )[1−exp(−s 2 /s 0 2 )]/[1+exp(−s 2 /s 0 2 )] with r(0)=r 0 and r(∞)=r. The initial and final radii of the taper are set to r 0 =1 μm and r=15 μm, respectively. FIG. 9( b ) shows the propagation of the fundamental mode launched at s=0 along the taper with z 0 =0.3 mm. It is seen that this taper is non-adiabatic and several interfering modes are excited. FIG. 9( c ) shows the propagation of the same mode along a longer taper with z 0 =1 mm. In this case, the taper adiabatically transforms the initial mode into a shifted fundamental mode of the coiled optical fiber. No transmission loss was detected within the accuracy of calculations. The size of the adiabatic taper shown in FIG. 9( c ) is negligible compared to the dimensions of an exemplary optical fiber coil device: its total length is only ˜2.5 mm, i.e., close to the diameter of an exemplary microfiber coil device.
As mentioned above, an aspect of the adiabatic optical fiber coupler of the present invention is that the fiber itself preferably remains in a spaced-apart arrangement with the optical fiber coil. FIG. 10 illustrates this concept in an arrangement for interconnecting two separate optical fiber coil devices. FIG. 10( a ) can be considered as a prior art arrangement, with a length of optical fiber extending from a first optical fiber coil 1 - 1 and thereafter coiled around a second optical fiber coil 1 - 2 . Inasmuch as the optical fiber remains in contact with central core rod 3 - 1 until extending to second optical fiber coil 1 - 2 (illustrated as point X in FIG. 10( a )), coupling of the propagating signal from the optical fiber into core rod 3 - 1 can occur. Similarly, additional loss will occur as the optical fiber contacts second central core rod 3 - 2 at point Y.
In contrast, and in association with the present invention, an adiabatic tapered optical fiber coupler is used to interconnect coils 1 - 1 and 1 - 2 , in the manner shown in FIG. 10( b ). In this case, the portion of fiber used to provide the interconnection is first extended away from central core rod 3 - 1 at point x, where thereafter the optical fiber is tapered and curved to provide an adiabatic transformation from the shifted, peripheral location of the coil into a conventional optical signal propagating along the longitudinal axis of a single mode microfiber. The optical fiber remains separated from both coils as shown in FIG. 10( b ), as the fiber nears second optical fiber coil 1 - 2 . Prior to coupling into optical fiber coil 1 - 2 , the coupling optical fiber is curved and enlarged in diameter, in the manner discussed above, to shift the optical signal propagating along the longitudinal axis into the peripheral region associated with along second coil 1 - 2 . Advantageously, by maintaining a separation between the adiabatic coupler and the fiber coils, propagation and coupling losses are minimized.
While the present invention has been particularly described and shown with reference to particular embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the claims appended hereto.
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An optical fiber coupler is formed of a section of optical fiber that is positioned between a conventional input fiber (for example, a single mode fiber) or waveguide and a coiled optical fiber device. The adiabatic coupler is coiled (or, at least, curved) to assist in transforming a conventional fundamental mode optical signal propagating along the longitudinal axis of the input fiber to an optical signal that is shifted into a peripheral region of the coiled optical fiber. Moreover, the pitch of an inventive coiled optical fiber coupler can be controlled to assist in the adiabatic transformation process.
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BACKGROUND
[0001] The present disclosure relates to synchronized wireless data concentrators. In particular, it relates to synchronized wireless data concentrators for airborne wireless sensor networks.
SUMMARY
[0002] The present disclosure relates to an apparatus, system, and method for synchronized wireless data concentrators for airborne wireless sensor networks. In one or more embodiments, the disclosed system for airborne wireless sensor networks includes at least one wireless data concentrator (WDC) operable as a router. The system further includes at least one processor that runs hosted applications related to at least one WDC operable as a router. Also, the system includes at least one network switch that is connected to at least one WDC operable as a router and connected to at least one processor. In addition, the system includes at least one node that is wirelessly in communication with at least one WDC operable as a router.
[0003] In one or more embodiments, at least one WDC operable as a router includes at least one standard router, and at least one node that operates as a standard node. In at least one embodiment, at least one standard router and/or at least one node operable as a standard node employ a Zigbee communications protocol. In some embodiments, at least one standard router transmits and receives signals to at least one node operable as a standard node. In one or more embodiments, at least one node operable as a standard node is powered by battery power, a wired power line, and/or strong harvested energy. In some embodiments, the strong harvested energy is harvested from thermoelectric power, vibration, and/or inductive coupling to a high voltage (e.g., a high voltage produced by generators).
[0004] In at least one embodiment, at least one WDC operable as a router includes at least one green router, and at least one node that operates as a green node. In one or more embodiments, at least one green router and/or at least one node operable as a green node employ the Zigbee communications protocol. In some embodiments, at least one green router receives signals from at least one node operable as a green node. In one or more embodiments, at least one node operable as a green node transmits its state three times sequentially in a row to at least one green router. In at least one embodiment, at least one node operable as a green node is powered by harvested energy. In some embodiments, the harvested energy is harvested from solar power and/or manual actuation power (e.g., the manual action of flipping a switch).
[0005] In one or more embodiments, at least one processor is an application server. In at least one embodiment, at least one network switch is an Ethernet switch (e.g., an IEEE-1588 Ethernet switch). In some embodiments, the disclosed system further includes at least one WDC operable as a coordinator. In at least one embodiment, at least one WDC operable as a coordinator employs the Zigbee communications protocol. In one or more embodiments, at least one WDC operable as a coordinator is in wireless communication with at least one WDC operable as a router. In at least one embodiment, at least one WDC operable as a coordinator coordinates communications with at least one WDC operable as a router.
[0006] In at least one embodiment, the disclosed method for airborne wireless sensor networks involves transmitting state information from at least one node. The method further involves receiving, by at least one wireless data concentrator (WDC) operable as a router, the state information from the node(s). In addition, the method involves transmitting the state information from at least one WDC operable as a router. Additionally, the method involves receiving, by at least one WDC operable as a coordinator, the state information from the WDC(s) operable as a router. Further, the method involves sending the state information, by at least one WDC operable as a coordinator, to at least one processor for processing. In one or more embodiments, the method further involves coordinating, by at least one WDC operable as a coordinator, communications with at least one WDC operable as a router. In at least one embodiment, the state information is sent from at least one WDC operable as a coordinator to at least one processor via a network switch.
[0007] In one or more embodiments, the disclosed wireless data concentrator (WDC) for airborne wireless sensor networks includes at least one router, where at least one node is in communication with the router(s). In addition, the disclosed WDC includes at least one microprocessor, where the microprocessor(s) processes signals received by the router(s) from the node(s). The disclosed WDC further includes at least one clock crystal, where the clock crystal(s) is used for synchronizing communications for at least one router.
[0008] The features, functions, and advantages can be achieved independently in various embodiments of the present inventions or may be combined in yet other embodiments.
DRAWINGS
[0009] These and other features, aspects, and advantages of the present disclosure will become better understood with regard to the following description, appended claims, and accompanying drawings where:
[0010] FIG. 1 shows a high level architectural view of the disclosed system for synchronized wireless data concentrators (WDCs) for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure.
[0011] FIG. 2 is a detailed diagram showing the process for how keys are securely managed within the system of FIG. 1 , in accordance with at least one embodiment of the present disclosure.
[0012] FIG. 3 is a diagram of a two-channel wireless data concentrator (WDC) that is employed by the system of FIG. 1 , in accordance with at least one embodiment of the present disclosure.
[0013] FIG. 4 is a diagram of a four-channel WDC, in accordance with at least one embodiment of the present disclosure.
[0014] FIG. 5 is a diagram of an eight-channel WDC, in accordance with at least one embodiment of the present disclosure.
[0015] FIG. 6 is a diagram of a sixteen-channel WDC, in accordance with at least one embodiment of the present disclosure.
[0016] FIG. 7 is a detailed diagram depicting the extended precision time protocol (PTP) operation on a two-channel WDC, in accordance with at least one embodiment of the present disclosure.
[0017] FIG. 8 is a table that shows the typical drift rate for the two crystal (Xtal) devices employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure.
[0018] FIG. 9 is a diagram depicting a modification of a standard Zigbee/IEEE-802.15.4 software stack which is employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure.
DESCRIPTION
[0019] The methods and apparatus disclosed herein provide an operative system for wireless data concentrators. Specifically, this system relates to synchronized wireless data concentrators (WDCs) for airborne wireless sensor networks. In particular, the present disclosure teaches a wireless data concentrator (WDC) architecture that significantly advances the flexibility, adaptability, utility, determinism, and security in a large network of wireless sensor network (WSN) devices, which are applied to a commercial aerospace environment. The application space for aircraft WSNs is diverse and poses challenges in reliability, bandwidth management, latency, and security domains. The present disclosure sets forth a broad architecture structure, and a WDC design, which can support the objectives of improved flexibility, adaptability, utility, determinism, and security more than the currently offered solutions.
[0020] Key aspects that are provided by the disclosed system are: 1.) precision time synchronization of nodes in a wireless sensor network to enable a system design pattern of time-based real-time programming; 2.) bandwidth, throughput, and latency management in a large IEEE-802.15.4 wireless sensor network through the use of a wired Ethernet backbone topology; 3.) a distributed trust center, a wired secure key-transport, and key management system; and 4.) parallel WSN channel operation for optimized wireless bandwidth.
[0021] Zigbee is a type of Low Power Wireless Personal Area Network (LP-WPAN) data communication protocol stack, which is used to standardize low data rate transmission between low power wireless devices. Zigbee does not describe the entire software communication stack, but is rather a set of networking framework layers built on top of the IEEE-802.15.4 standard. Systems and environments that typically deploy Zigbee are environments such as home automation, home entertainment, building automation and, most recently, smart energy. Aerospace non-essential systems represent a new area for LP-WPAN deployment so that smart wireless sensors can be distributed throughout the aircraft cabin, structures, and systems; and can provide monitoring, alerting, on-demand services, and non-essential control functions.
[0022] However, when considering employing Zigbee for a large scale architecture adaptable to a wide range of aerospace applications, it is important to understand some of the shortcomings imposed by Zigbee. Although Zigbee is a robust stack, certain design decisions have been made by commercial microprocessor/radio hardware chip manufacturers and Zigbee software stack vendors. These decisions have been made in order to accommodate the size of object code that can fit into current program memory and runtime variables in data memory within various low cost Zigbee/802.15.4 radios in today's marketplace. Some of these shortcomings are: lack of medium access control (MAC) and network (NWK) layer support for time-slotted or time-based design patterns, the data security is limited to symmetric-key algorithms, lack of a secure key management system, and lack of robust support for energy harvesting sensor devices.
[0023] The system of the present disclosure sets forth an architectural structure and a network topology that significantly improves over the limitations stated above to better address the additional environmental and application requirements of airborne systems. The main features of the disclosed system are: 1.) an introduction of a low cost, local host microprocessor within the wireless data concentrator, which is hardwire connected to both an Ethernet backbone and a plurality of wireless sensor network “router” devices; 2.) an inclusion of a system-wide hierarchical, precision time distribution means to bridge into the wireless sensor network area; 3.) a distributed security trust center mechanism for fast and secure management of network keys; and 4.) parallel Zigbee channel capability that can better handle throughput, latency, and energy harvesting performance demands on the system.
[0024] FIG. 1 shows a high level architectural view of the disclosed system 100 for synchronized wireless data concentrators (WDCs) 110 , 120 for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. In this figure, the system 100 is shown to include five (5) WDCs. Four (4) of the WDCs 120 are operating as routers, and one WDC 110 is operating as a coordinator. The one WDC 110 operating as a coordinator 115 communicates wirelessly (as denoted by the dashed lines in the figure) with the four WDCs 120 , and coordinates the communications of the four WDCs 120 , which are all situated in a single aircraft zone. In general, one WDC 110 operating as a coordinator is employed per aircraft zone. An aircraft zone is, for example, a specific defined area within the cabin and/or cockpit of an aircraft. The WDC 110 operating as a coordinator is wired (as denoted by the solid line in the figure) to an IEEE-1588 Ethernet switch 160 , and employs the Zigbee communications protocol.
[0025] The four WDCs 120 operating as routers are wired (as denoted by the solid lines in the figure) to the IEEE-1588 Ethernet switch 160 , which is connected to an application server 145 . The application server 145 , which includes at least one processor, is used to run host applications. In addition, a GPS receiver 155 is connected to an IEEE-1588 Grand Master 150 , which uses a GPS signal from the GPS receiver 155 for time synchronization. The Grand Master 150 is connected to the IEEE-1588 Ethernet switch 160 , and passes time synchronization data packets to the IEEE-1588 Ethernet switch 160 through that connection.
[0026] Each of the four WDCs 120 operating as routers is shown to include one Zigbee green router 125 and one Zigbee standard router 130 . It should be noted that in other embodiments, the system 100 may employ WDCs 120 that include various different quantities of Zigbee green routers 125 and Zigbee standard routers 130 . Both the Zigbee green router 125 and the Zigbee standard router 130 employ the Zigbee communications protocol. The Zigbee standard router 130 transmits and receives signals to Zigbee standard endpoint nodes 140 , which contain monitoring sensors and are situated about the aircraft cabin within the specific aircraft zone of the WDCs 110 , 120 . The signals include information regarding the state of the Zigbee standard endpoint nodes 140 , time synchronization information, as well as acknowledgement (ACK) information (e.g., acknowledgement information sent in ACK data packets) regarding the receipt of the state information. The Zigbee standard endpoint nodes 140 are powered by various means including, but not limited to, battery power, a wired power line, and strong harvested energy. It should be noted that types of strong harvested energy include, but are not limited to, thermoelectric power, vibration, and inductive couple to a high voltage.
[0027] The Zigbee green router 125 receives signals from Zigbee green endpoint nodes 135 , which contain monitoring sensors and are situated about the aircraft cabin within the specific aircraft zone of the WDCs 110 , 120 . It should be noted that the Zigbee green router 125 does not transmit signals, it only receives signals. The Zigbee standard endpoint nodes 135 periodically transmit their respective state three times sequentially in a row. Since the Zigbee green router 125 cannot transmit signals, the Zigbee green router 125 does not send acknowledgement signals regarding the receipt of state information to the Zigbee green endpoint nodes 135 . The Zigbee green endpoint nodes 135 are powered by harvested energy, which includes, but is not limited to, solar power and manual actuation power.
[0028] The system 100 of FIG. 1 is applicable to numerous applications within the aircraft. Examples of these applications include, but are not limited to, passenger control of reading lights; window dimming and flight attendant call lights from energy harvesting control buttons in the seats; aircraft systems monitoring functions, such as temperature and air flow within the passenger cabin; and sensors within the aircraft structure, engines, landing gear, wings, tail sections, power systems, hydraulic systems, or any other system within the aircraft that can benefit from prognostic monitoring of aircraft health and system state. The sensors of the endpoints 135 , 140 are designed to sense various things according to their function for the particular application(s) of the system 100 . Types of things that the sensors are designed to sense include, but are not limited to, temperature, light, power, and air flow. In this figure, a software application server 145 contains certain “hosted functions.” These “hosted functions” are software programs designed to receive information from various sensing elements. The programs then store and process this information into useful operations for passengers, crew, and/or maintenance personnel, as dictated by the requirements of the “function.” The “hosted functions” communicate with various sensors via the Ethernet switch 160 , which is connected to a plurality of WDCs 110 , 120 strategically positioned throughout an aircraft.
[0029] The disclosed system 100 uses the IEEE-1588 precision time protocol (PTP) as a baseline timing means that is extended to the various WDCs 110 , 120 through the IEEE-1588 compliant Ethernet switch 160 . In order to utilize IEEE-1588, a suitable PTP time generator, such as the Symmetricon “Timeprovider 5000”, is utilized to provide a grand master time base to the network. The IEEE-1588 grand master 150 typically gets its reference time from a GPS signal to provide better than a 100 nanosecond time synchronization to global Earth time. Precision time packets are distributed through the Ethernet switch 160 to each of the WDCs 110 , 120 , where the time synchronization is maintained at each WDC 110 , 120 within the typical performance limits of a typical IEEE-1588 Ethernet network (i.e. <microsecond). An important feature of this system 100 design is the bridging of the PTP protocol through the 802.15.4 Zigbee router devices 125 , 130 to Zigbee endpoints 135 , 140 served by each router 125 , 130 within a WDC 120 . In at least one embodiment, a single WDC 110 coordinator 115 starts the network in a traditional Zigbee protocol, but then can optionally distribute the coordinator function to selected WDCs 120 . This feature helps to improve the performance and management of large number of sensors within the purview of the WDC 110 selected for the distributed coordinator function, when the number of endpoints 135 , 140 exceeds a predetermined threshold.
[0030] FIG. 2 is a detailed diagram showing the process for how keys are securely managed within the system 100 of FIG. 1 , in accordance with at least one embodiment of the present disclosure. A typical Zigbee environment will have a single trust center manager (TC M ) designated at the WDC 110 that is operating as a coordinator of the network. The Zigbee address of the trust center manager is usually aligned with the address of the WDC 110 that is operating as a coordinator, but this is generally a programmable register within any WDC 110 , 120 on a Zigbee network such that an alternate trust center (e.g., TC A , TC B , TC C , or TC D ) at a different WDC 120 may be established. Zigbee Pro only defines support for symmetric encryption keys. Zigbee networks employ three types of keys: a network key, a link key, and a master key. A network key is applicable to every Zigbee WDC device 110 , 120 in a given personal area network (PAN) within the aircraft (i.e. a Zigbee local network is identified by one unique PAN identification (ID)). A link key is a key established between two WDC devices 110 , 120 of a Zigbee application. The master key is a key which is used to allow a Zigbee WDC device 110 , 120 to initially join a network. In a high security mode, as defined in the Zigbee Pro specification, the master key is used to establish link keys, and must be configured on new WDC devices 110 , 120 “out-of-band.” “Out-of-band” refers to programming or configuring a WDC device 110 , 120 in an environment different from the wireless network, such as manually typing a key into a WDC device 110 , 120 at the time of manufacturing.
[0031] FIG. 2 shows a preferred embodiment of a trusted supplier 210 providing device identifiers (“MAC addresses”) to a global universal trust 200 , which will then issue a set of trusted master keys corresponding to each of the WDC devices' MAC addresses. The trusted supplier 210 then pre-configures the WDC device 110 , 120 with the master key issued by the global universal trust 200 . In particular, as shown in this figure, a trusted Zigbee device supplier/manufacturer 210 sends a request 220 to the global universal trust center 200 for a key for a new WDC device 110 , 120 that it is manufacturing. The request that the supplier 210 sends to the trust center 200 includes the MAC address for the new WDC device 110 , 120 . The trust center 200 has a global key manifest 230 that contains a listing of the specific keys that correspond to particular WDC device MAC addresses. The trust center 200 sends to the supplier 210 a key 240 , which corresponds to the WDC device's MAC address according to the global key manifest 230 . In response, the supplier 210 sends a response 250 to the trust center 200 indicating that the supplier 210 successfully received the key (acknowledgement (ACK)) or did not successfully receive the key (no acknowledgement (NAK)).
[0032] Upon initial commissioning of WDC devices 110 , 120 on a new aircraft (or for replacement equipment on an existing aircraft), a trusted Internet connection must be made between the application server 145 and the global universal trust 200 (i.e. trust center 200 ). New WDC devices 110 , 120 that attempt to join the aircraft Zigbee network will cause an aircraft trust center (located at a WDC 110 , 120 ) to communicate with the trust center manager function (TC MGR) 260 , which will make a request to the global universal trust 200 for a master key for the new WDC device 110 , 120 requesting to join the network. Once a WDC device 110 , 120 has been authenticated by the trust center manager 260 , then a key exchange process will occur, and a new encrypted key will be delivered to the new WDC device 110 , 120 joining the Zigbee network. In particular, as shown in FIG. 2 , the trust center manager function (TC MGR) 260 sends a request 270 to the global universal trust 200 for a key for the new WDC device 110 , 120 that is requesting to join the network. The request 270 that the trust center manager function 260 sends to the trust center 200 includes the MAC address for the new WDC device 110 , 120 . The global universal trust 200 sends 280 to the trust center manager function 260 a key 240 , which corresponds to the WDC device's MAC address according to the global key manifest 230 . In response, the trust center manager function 260 sends a response 290 to the global universal trust 200 indicating that the trust center manager function 260 successfully received the key (acknowledgement (ACK)) or did not successfully receive the key (no acknowledgement (NAK)). It should be noted that additional keys and data can be exchanged on the network with the new WDC device 110 , 120 . This includes issuing a network key, which is required for all Zigbee devices 110 , 120 on a given PAN.
[0033] A feature of this key management method is an optional means to change the master key to a new value once the pre-determined master keys have been used to allow a WDC device 110 , 120 to join the network. The new master key may be additionally changed at a periodic rate with a last-known master key retained in the event of a master key change error event. If an original master key is lost, after being changed to a new master key, and having rolled past the last-known master key, it is gone forever. Only through a specific trusted new request sequence to the global universal trust 200 may a new pre-determined master key be delivered to a WDC device 110 , 120 whose master key becomes corrupt or lost. This level of security provides another long term layer of assurance that no rogue devices may be allowed to join an aircraft wireless sensor network.
[0034] Another feature is the use of a distributed trust center scheme. For large networks of many hundreds or thousands of WDC devices 110 , 120 , having one trust center for the entire network can become unwieldy, and have undesirable latency and memory problems. As such, a distributed trust center allows for a management of subnets (e.g., PANs) by distribution of the trust center key tables 295 efficiently through a secure wired transport. A trust center is also responsible for updating the network key in a normal Zigbee network, and having this distributed trust center function located at the WDC device 110 , 120 enables a more deterministic behavior to occur during a network key update. The additional security feature of changing the master key requires that a list 295 of master keys and of the last-known master keys is maintained at each trust center responsible for a given network. This updated list is also synchronized with the trust center manager hosted function 260 at the application server 145 level to ensure a coherent backup of the trust center data is maintained should a WDC device 110 , 120 , acting as a trust center become non-functional or is replaced. Finally, each trust center is designated as a primary or backup trust center on a given PAN. Stated another way, in at least one embodiment, each PAN has a minimum of two trust centers, where each trust center contains a duplicate of the key list 295 for the WDC devices 110 , 120 within that PAN.
[0035] FIG. 3 is a diagram of a two-channel wireless data concentrator (WDC) 120 that is employed by the system of FIG. 1 , in accordance with at least one embodiment of the present disclosure. Each WDC 120 , regardless of how many wireless router channels 125 , 130 are supported, includes a local host Ethernet gateway microprocessor 300 , which contains IEEE-1588 precision time protocol (PTP) hardware support within its TCP/IP MAC layer. Examples of devices that may be employed by the WDC 120 for the local host Ethernet gateway microprocessor 300 include, but are not limited to, a ST Micro STM32F107 device and a ARM Cortex-M3 32-bit RISC core microprocessor. The STM32F107 device, when employed by the local host Ethernet gateway microprocessor 300 for example, acts as the gateway microprocessor 300 and connects to both of the IEEE 802.15.4/Zigbee router microprocessors 125 , 130 by way of one of the serial peripheral interface (SPI) ports that are configured to clock data at a minimum rate of 4 megabits per second (Mbps). The local host microprocessor 300 also contains a software client 310 to handle the time management functions of the PTP network function, which provides the precise time. The local host microprocessor 300 also distributes a precise hardware interrupt signal to each of the 802.15.4/Zigbee router microprocessors 125 , 130 to enable the feature of extended precision time protocol, which is described later in the present disclosure.
[0036] FIG. 4 is a diagram of a four-channel WDC 400 , in accordance with at least one embodiment of the present disclosure. In this figure, the four-channel WDC 400 is shown to include one Zigbee green router 125 and four Zigbee standard routers 130 . FIG. 5 is a diagram of an eight-channel WDC 500 , in accordance with at least one embodiment of the present disclosure. In particular, in this figure, the eight-channel WDC 400 is shown to include two Zigbee green routers 125 and six Zigbee standard routers 130 . FIG. 6 is a diagram of a sixteen-channel WDC 600 , in accordance with at least one embodiment of the present disclosure. In this figure, the eight-channel WDC 400 is shown to include four Zigbee green routers 125 and six Zigbee standard routers 130 .
[0037] FIG. 7 is a detailed diagram depicting the extended precision time protocol (PTP) operation on a two-channel WDC 120 , in accordance with at least one embodiment of the present disclosure. The microprocessor 300 utilizes a 20.000 megahertz (MHz) (0.5 parts per million (ppm)) clock 700 , which enables a less frequent update period from the PTP master across the Ethernet network than a clock frequency that is less accurate. Also, a low cost 32.768 kilohertz (KHz) watch crystal (Xtal) 710 is used for the Zigbee devices that are nodes (i.e. the Zigbee green endpoint nodes 135 and the Zigbee standard endpoint nodes 140 ). In this case, if a node is battery operated (i.e. a battery operated Zigbee standard endpoint node 140 ), it will be sleeping most of the time at a very low current state. This will require a very low frequency clock source to keep backup time established so that a less frequent synchronization is required.
[0038] In this figure, the Zigbee standard router 130 is shown to be transmitting and receiving time synchronization signals to the Zigbee standard endpoint node 140 . In particular, at time T 1 , the Zigbee standard router 130 sends a synchronization signal 720 (i.e. Sync( 1 ) 720 ) to the Zigbee standard endpoint node 140 , and at time T 2 , the Zigbee standard router 130 sends a follow-up signal 730 (i.e. Follow_Up( 2 ) 730 ) to the Zigbee standard endpoint node 140 . At time T 3 , the Zigbee standard endpoint node 140 sends a delay request signal 740 (i.e. Delay_Req( 3 ) 740 ) to the Zigbee standard router 130 . And, finally, at time T 4 , the Zigbee standard router 130 sends a delay response signal 750 (i.e. Delay_Resp( 4 ) 750 ) to the Zigbee standard router 130 .
[0039] The PTP protocol introduces a hierarchical firewall nature of synchronization. To represent this synchronization firewall, a time synchronization firewall 760 (i.e. PTP Time Firewall 760 ) is shown to be present within the WDC 120 . This firewall 760 prevents any downstream extended PTP effect from disturbing the primary Ethernet PTP channels 125 , 130 . In other words, the time accuracy of the extended nodes 135 , 140 is strictly governed by the time accuracy and stability of the WDC 120 local host microprocessor 300 .
[0040] FIG. 8 is a table 800 that shows the typical drift rates for the two crystal (Xtal) devices employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. In particular, the table 800 shows that the 20 MHz Xtal has better stability (0.5 parts per million (ppm) +/− spec (i.e. nominal frequency)) than the 32.768 KHz Xtal (5 ppm +/− spec).
[0041] FIG. 9 is a diagram depicting a modification of a standard Zigbee/IEEE-802.15.4 software stack which is employed by the disclosed system for synchronized WDCs for airborne wireless sensor networks, in accordance with at least one embodiment of the present disclosure. In this modification, PTP time stamping support 900 is added to the MAC layer 910 to enable a low latency capture of the time when packets arrive on the 802.15.4 PHY layer 920 . This time stamp information is then communicated directly to the application layer 930 where a special PTP software application 940 is resident to compute the extended PTP synchronization. Once this operation is completed, then other application objects within the Zigbee endpoint nodes 135 , 140 may take advantage of a high accuracy time stamp. To allow for power down, drift trend information can be captured over time to determine the drift statistics. Referring to FIG. 8 again, one can see that the maximum drift count of the 32.768 Khz clock would be between 9 and 10 counts per minute. Once the drift is monitored in a real system (after synchronization is complete), then the drift can be managed by compensation based on the long term drift trend. A feature of this is a start up period where during certain periodic times, a higher frequency PTP synchronization occurs to determine the absolute drift during the non-critical time endpoint (i.e. node 135 , 140 ) operation period.
[0042] Although certain illustrative embodiments and methods have been disclosed herein, it can be apparent from the foregoing disclosure to those skilled in the art that variations and modifications of such embodiments and methods can be made without departing from the true spirit and scope of the art disclosed. Many other examples of the art disclosed exist, each differing from others in matters of detail only. Accordingly, it is intended that the art disclosed shall be limited only to the extent required by the appended claims and the rules and principles of applicable law.
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A system, method, and apparatus for a synchronized wireless data concentrator are provided for facilitating a precisely synchronized system of nodes in a wireless sensor network for airborne data systems. The wireless data concentrator contains a plurality of IEEE 802.15.4 radio/micro-processor subsystems, which are connected to a local host microprocessor, which is in turn connected to an aircraft data network. The airplane data network also contains a precision clock source and a plurality of specialized network switches, which have a low-jitter data-path routing capability.
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RELATED APPLICATIONS
This application is a divisional of and claims priority to U.S. patent application Ser. No. 10/978,778, filed on Nov. 1, 2004, and hereby incorporated by reference.
TECHNICAL FIELD OF THE DISCLOSURE
This invention pertains to computer calculations involving complex numbers and, more specifically, to a novel method of allocating space in registers for floating point representations of complex numbers.
BACKGROUND OF THE DISCLOSURE
One of the fundamental issues in computer science computation is the representation of numbers, specifically integers, real numbers and complex numbers. Although there are bit lengths that can easily accommodate the result of most integer and real number computations, problems arise when a required bit length is fixed or predetermined and the computation includes the manipulation and storage of complex numbers. The primary reason for this is that complex numbers include two (2) components, or a “real” and an “imaginary” component.
Each component is typically represented as a floating point number, which comprises three fields: a sign, a significand, or “mantissa,” and an exponent. The sign field represents whether the corresponding number is positive or negative. According to IEEE standard 754 for floating point numbers, the mantissa field is defined as an explicit or implicit leading bit to the left of the number's implied binary point and a fraction field to its right. The exponent field represents the power to which a base number must be raised to generate the represented number.
If sixteen (16) bits are reserved for each of the real and imaginary components of a complex number, typically, one (1) bit is employed for the sign, either two (2) or four (4) bits are employed for the exponent, and the remaining thirteen (13) or eleven (11) bits, respectively, are employed for the mantissa.
A method is needed for the storage of complex numbers in a computing or communication system. One such communication system that deals with complex numbers includes digital subscriber line type systems. The ADSL and VDSL are exemplary types of digital subscriber communication systems. The VDSL standard as provided by the ANSI T1E1.4 Technical Subcommittee, provides guidelines for the transmitter and receiver within the VDSL modem. Very high bit rate DSL (VDSL) is currently capable of providing speeds of 52 Mbps downstream and 16 Mbps upstream. ADSL is capable of 10 Mbps downstream and 800 Kbps upstream. Other standards beyond ADSL and VDSL are being considered by standards bodies. For example, VDSL2 is one such standard. To implement these current and upcoming standards, a discrete multitone (DMT) transceiver is required that can operate at higher bit rates efficiently. A method for dealing with complex numbers that allows digital subscriber line technologies to be efficient enhances the value of such technologies by reducing equipment size and maximizing communication throughput. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.
SUMMARY OF THE INVENTION
The invention provides a method of storage for complex numbers that employs shared bit fields. As mentioned above, complex numbers have real and imaginary components, each of which is represented by a floating point number, which has sign, significand and exponent fields. If, for the sake of an example, a floating point is stored in a sixteen (16) bit memory space, typically one (1) bit is reserved for the sign, eleven (11) bits are reserved for the significand and a four (4) bit field remains for the storage of the exponent. For the purposes of this Specification, the sign field and the significand fields are combined and referred to simply as a “signed mantissa.” Of course, as explained above, a complex number contains two (2) floating point numbers so a complex number is typically thirty-two (32) bits in length, or sixteen (16) bits for each of two floating point numbers.
In the disclosed implementation, rather than each floating point component of a complex number having its own distinct signed mantissa and exponent fields, each component only includes distinct sign and significand fields and a single exponent field is shared by the two components. If a four (4) bit exponent field is shared by the real and imaginary components of a complex number, then each component is able to include fourteen (14) bits rather than twelve (12) bits to store the signed mantissa. This two (2) bit advantage greatly increases the level of precision corresponding to the relevant floating point numbers and thus the system in which they are employed.
An embodiment is directed to a Fourier transform architecture for use in a communication system that includes a memory that stores complex numbers employing shared bit fields.
The example described above is not intended to limit the claimed subject matter. The techniques provided work in a wide variety of numerical configurations and memory storage schemes.
This summary is not intended as a comprehensive description of the claimed subject matter but, rather, is intended to provide a brief overview of some of the functionality associated therewith. Other systems, methods, functionality, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following brief descriptions taken in conjunction with the accompanying drawings, in which like reference numerals indicate like features.
FIG. 1 is a block diagram of an application specific integrated circuit (ASIC) configured as a VDSL/ADSL communication engine in accordance with an embodiment of the present invention.
FIG. 2 is an enhanced block diagram of portions the ASIC shown in FIG. 1 in accordance with an embodiment of the present invention.
FIG. 2A is a block diagram of portions of the ASIC shown in FIG. 1 illustrating a peripheral bus and peripheral memory configuration in accordance with an embodiment of the present invention.
FIG. 3 is a block diagram illustrating a transmit path in accordance with an embodiment of the present invention
FIG. 4 is a block diagram illustrating IFFT/FFT functionality interactions for a signal transmit path in accordance with an embodiment of the present invention.
FIG. 5 is a block diagram illustrating IFFT/FFT functionality interactions for a signal receive path in accordance with an embodiment of the present invention.
FIG. 6 is a block diagram illustrating decoder functionality in accordance with an embodiment of the present invention.
FIG. 7 is a timing diagram illustrating Showtime operation in accordance with an embodiment of the present invention.
FIG. 8 is a block diagram illustrating an IFFT/FFT architecture in accordance with an embodiment of the present invention.
FIG. 9 is a diagram of a radix-8 butterfly architecture in accordance with an embodiment of the present invention.
FIG. 10 is a block diagram of hardware components used to calculate partial products within a butterfly configuration for FFT and IFFT calculations in accordance with an embodiment of the present invention.
FIG. 11 is a flow diagram illustrating a method for addressing memory banks in an FFT and IFFT component in accordance with an embodiment of the present invention.
FIG. 12 is a table illustrating a plurality of banks for holding partial products during different stages of FFT and IFFT processing in accordance with an embodiment of the present invention.
FIG. 13 is a flowchart of a process for storing a complex number in a manner consistent with the claimed subject matter.
DETAILED DESCRIPTION
In order to facilitate an understanding of the present invention a glossary of terms used in the description of the present invention is provided below:
ADSL: Asynchronous Digital Subscriber Line
AFE: Analog Front End
AGU: Address Generation Unit
CRC: Cyclic Redundancy Code
DFT: Discrete Fourier Transform
DMA: Direct Memory Access
DMT: Discrete Multi Tone
DRS: De-interleaver/Reed-Solomon decoder and descrambler
DSP: Digital Signal Processor
FCP: FEQ Slicer
FEQ: Frequency Domain Equalizer
FIFO: First In/First Out Memory
FIR: Finite Impulse Response
FFT: Fast Fourier Transform
IFFT: Inverse Fast Fourier Transform
RXCP: Time Domain Receive Co-Processor
Showtime: Operations involving transfer of data
SRS: Framer/Scrambler/Reed-Solomon Encoder
TEQ: Time Domain Equalizer
TRACTOR: Trellis and Constellation Encoder/Bit and Tone Ordering component.
TXCP: Time Domain Transmit Co-Processor.
VDSL: Very high bit-rate Digital Subscriber Line
VOC: VDSL overhead control channel
The multicarrier engine 100 shown in FIG. 1 illustrates an area and power efficient architecture for multicarrier communication. Engine 100 includes a single DSP core 102 that interacts with multiple hardware coprocessor blocks to enable core 102 to perform higher level functions and control and allow the multiple hardware blocks to perform DMT calculations and data movement.
Engine 100 includes a DSP core 102 that can be implemented with a core compatible with a Motorola 56300 DSP with an X, Y, and P memory space 103 . In an embodiment, all of the memory required for VDSL or four channel ADSL operations are provided within engine 100 . In other embodiments, external memory can be added to engine 100 to support advanced features.
Engine 100 includes hardware co-processors, including encoder 104 , decoder 106 , FFT/IFFT coprocessor 108 , TXCP coprocessor 110 , RXCP 129 and an AFE interface control processor 112 . Co-processors 104 , 106 , 108 , 110 , 112 and 129 perform all DMT operations from framing to cyclic extension and are configured to handle current and future DSL configurations independent of significant attention from core 102 .
Engine 100 interfaces with a computer or network via one of three ports, 114 , 116 and 118 , shown as Utopia 114 , 100 Mbs MII 116 and host port 118 . Each of ports 114 , 116 and 118 interface with FIFOs 120 and 121 . FIFOs 120 and 121 are coupled to encoder 104 and DMA 122 . FIFO 120 can be implemented as a shared FIFO between ports 114 and 116 because only one of the ports 114 and 116 is active at a time. FIFO 121 can be implemented as a dedicated host port FIFO and can operate with ports 114 and 116 or alone. Ports 114 and 116 can also be configured to share logic and the like. DMA 122 and core 102 can also interact with an external memory interface 124 to support adding external memory to engine 100 for advanced features. The local memory installed within each hardware block 104 , 106 , 110 and 112 and DMA 122 is coupled via point-to-point buses to IFFT/FFT 108 to send and receive data. Encoder 104 is coupled to receive data from FIFOs 120 and provide encoded data to IFFT/FFT co-processor 108 . Encoder 104 is configured to include a framer/scrambler/Reed-Solomon encoder component (SRS) 105 , which is coupled to a trellis and constellation encoder/bit extracting/tone ordering (TRACTOR) 107 . SRS 105 is also coupled to interleaver memory 109 . Additional encoder 104 components are further shown and described below with reference to FIG. 3 .
IFFT/FFT 108 is coupled for transmitting cyclic prefixes to FIFO 126 , and to transmit time domain co-processor TXCP 110 and AFE 112 . AFE 112 operates to both receive and transmit via interface 132 . For the receive path, AFE 112 receives data via interface 132 , provides the data to TEQ/RXCP 128 / 129 ., which passes the data to receive FIFO 130 and through to IFFT/FFT 108 . IFFT/FFT 108 runs either an inverse or forward transform, depending on whether engine 100 is transmitting or receiving.
According to an embodiment, IFFT/FFT 108 can be used as the central timer for engine 100 . Alternatively, the IFFT/FFT 108 in combination with RXCP 129 can operate to provide timing for engine 100 . RXCP 129 can implement both an auto mode and a manual mode, each mode limited by the amount of time required to run transforms in IFFT/FFT 108 . IFFT/FFT 108 has the most critical timing issues in the system and is configured to use FFT processing time markers to setup hardware blocks for a next symbol. More specifically, IFFT/FFT 108 uses approximately one half of a symbol period to process a FFT or IFFT. The end of FFT processing marks the beginning of the next sample period. At this time, according to one embodiment, an option is to allow all hardware blocks to be idle except for the continuous time domain blocks (FIFOs 120 , TXCP 110 , and AFE interface 112 ). Core 102 could use this time marker to setup hardware blocks for the next symbol. IFFT/FFT 108 provides start symbols to encoder 104 and decoder 106 .
In alternate embodiments, hardware blocks can be configured to run as directed by either an auto mode or a manual trigger and generate an interrupt on completion. Thus, for example, core 102 can operate to receive an interrupt identifying a hardware block as having completed a function and generate a request for another hardware block. A hardware block can also run via an auto-mode request received by another hardware block over a point-to-point bus, for example. Each hardware block can perform different functions according to the trigger or request received. The frequency domain components, such as IFFT/FFT 109 and FCP 113 perform according to received requests. In the embodiment, frequency domain components can be configured to perform operations during about 90% of a symbol period.
Decoder 106 receives a signal to begin processing as soon as the FFT output has been written to a decoder 106 input FIFO 132 . Conversely, RX FIFO 130 triggers encoder 104 when a programmable threshold mark is reached in FIFO 134 . Then, encoder 104 triggers IFFT/FFT 108 when data is available. Optionally, engine 100 controls timing directly and hardware timing signals are ignored in such a case. In either case, however, encoder 104 and decoder 106 each have almost a full symbol period in which to perform their calculations. Decoder 106 is shown including de-interleaver/Reed-Solomon decoder and descrambler (DRS) 111 , which receives data from FEQ slicer/FCP 113 . Like encoder 104 , DRS 111 is coupled to de-interleaver memory 115 . Referring to FIG. 2 , co-processors 104 , 106 , 108 , 110 and 112 each include a set of registers 204 , 206 , 208 , 210 and 212 mapped in the X or Y peripheral address space for core 102 . A peripheral bus interface 214 is used for transferring control information between core 102 and co-processors 104 , 106 , 108 , 110 and 112 . Local memories 224 , 226 , 228 , 230 , 232 and 234 within each co-processor are also indirectly mapped into a peripheral address space via a memory port, which can be implemented as a set of registers including address and data registers and a state machine. Specifically, in an embodiment, data is written to the address and data registers of the memory port. Core 102 writes to the address register first, the other side of the address register is coupled to the address bus of a memory. Core 102 can then write to the data register and the data is written to the memory associated with the register. In one embodiment, the mapping gives core 102 the ability to setup DMA transfers of data to and from distributed memories in co-processors 104 , 106 , 108 , 110 and 112 . In one embodiment, the address register has an auto-update mode. More specifically, a number of modes can be provided for auto-update, such as increment, increment by two, decrement, decrement by two, and decrement or increment per specific block. As will be appreciated by those of skill in the art with the benefit of this disclosure, an auto-mode can implement one or several of the increment and decrement modes according to system requirements.
Due to the high bandwidth requirements at various stages of the transmitter and receiver, core 102 is not used for data movement. Rather, each hardware block 104 , 106 , 108 , 110 and 112 transfers data to the next under DSP control. In an embodiment, each transfer can be configured to be self-managing, controlled by core 102 initialized parameters. In the embodiment, hardware flags synchronize timing between processes.
As shown in FIG. 2 , data transfers can occur on dedicated point-to-point buses 270 , shown between each hardware block 104 , 106 , 108 , 110 and 112 and each next logical block in a path. Because buses 270 are point-to-point, they are much simpler than those used for the bi-directional peripheral and DMA buses. Point-to-point buses 270 are designed to efficiently support the dataflow requirements for data transmit and receive (hereinafter referred to as “Showtime”) operation. In one embodiment, point-to-point buses 270 are configurable to enable the different requirements during training of engine 100 . Each hardware block can perform a pass-through from input to output on point-to-point buses 270 allowing the point-to-point buses to form a ring structure.
Point-to-point buses 270 can include five sets of signals: target channel, data bus, transfer request, transfer active, and a target ready. Each hardware module 104 , 106 , 108 , 110 and 112 in the transmit and receive paths has a point-to-point connection to the next logical module in the path. A simple handshake is used to transfer data on the buses. When a module is ready to transfer data on the bus it puts the target address on the address bus, the data on the data bus, and asserts the transfer request. The next module in the chain indicates that it is ready to accept data on the bus by asserting the ready signal. A data transfer occurs on every cycle in which the transfer request and ready signals are asserted. The transfer active signal is used to frame a block transfer of data. Either the transmitter or receiver can throttle the block transfer using the handshake signals. Importantly, according to an embodiment, the handshake procedure is completed independent of round trip timing between receiver and transmitter. Thus, most of a clock cycle becomes available for transfer of data and control signals between hardware blocks. The timing is therefore localized thereby reducing routing issues for deep submicron implementation.
The hardware co-processor blocks can be triggered to begin performing calculations by core 102 or by a signal from another hardware block.
Transmit Path Operation
Referring now to FIG. 3 in combination with FIG. 1 , transmit path operation is now described. The data to be transmitted to a remote modem arrives on the Utopia 114 , MII 116 , or host Port 118 interfaces and is deposited into either FIFO 120 or 121 . Because Utopia 114 and Ethernet interfaces such as MII 116 do not generally require simultaneous operation, a single input FIFO 120 is shared by both interfaces 114 and 116 . Host port 118 does not share a FIFO with these interfaces because it can possibly be required to enable communication between two engine 100 s during Showtime. Thus, an embodiment provides that host port 118 has a separate smaller FIFO 121 . DMA controller 122 transfers FIFO data to X or Y data memory 123 for use by core 102 or directly to encoder 104 . In one embodiment, Utopia 114 and 100 Mbs MII 116 share large FIFOs, such as 4K bytes per channel for 16K bytes total bytes. Host port 118 can be configured to interface with a small 24 byte FIFO 121 . FIFO 121 can be used to shield block data from DMA latency and provide higher DMA performance. In one embodiment, FIFO 121 is configured to perform data conversions, including bit swapping, byte swapping, byte packing and the like.
The transfers of FIFO data and the subsequent processing only occur during Showtime operation. In an embodiment, the maximum data rate in the transmit direction is 120 Mbs. After core 102 receives data in memory, the data is available for processing or can be sent to encoder 104 via DMA 122 . In one embodiment, core 102 memory is used to provide additional flexibility and buffering. Since the data can also be DMA transferred directly to encoder 104 from a FIFO 120 , 121 , an embodiment provides for enabling sufficient space in the relevant FIFO to hold one sample period of input data. When multiple channels are employed, FIFO space can be divided evenly among the channels.
In FIG. 3 , encoder 104 is shown configured to perform framing, CRC generation, scrambling, interleaving, which are performed in SRS 105 , as well as bit extraction, constellation encoding, and tone ordering in TRACTOR 107 . Encoder 104 is shown in FIG. 3 as including SRS 105 , a 32 Kbyte interleave buffer 109 , TRACTOR 107 , which is coupled to both interleave buffer 109 and SRS 105 . TRACTOR 107 is shown coupled to bit load table 302 and to tone order map 304 . Tone order map 304 is coupled to IFFT input buffer 134 .
Encoder 104 functions are divided between SRS 105 and TRACTOR 107 modules. In an embodiment, encoder 104 is configured independent of fixed logic that would be required for these operations. Instead, SRS 105 and TRACTOR 107 are designed to be reasonably generic and programmable by core 102 . Thus, encoder 104 can be altered for future specification changes. Further, hardware components therein can be reused for training and other non-Showtime functions.
Regarding the functionality within encoder 104 , SRS 105 fetches data from core 102 memory or directly from FIFO 120 via DMA 122 and performs framing, CRC generation, scrambling, and Reed-Solomon encoding. Next, SRS transmits the data in the interleave memory. These functions can be performed serially, thus, SRS 105 has minimal local storage requirements. Four small input FIFOs are used to buffer the incoming DMA transfers. The four FIFOs are provided to support the four basic types of input data: fast mode payload, fast mode overhead, interleaved mode payload, and interleaved mode overhead. In one embodiment, FIFO 121 can be configured to be located within encoder 104 rather than as a separate entity. Thus, depending on system requirements, FIFO 121 can be configured to be duplicated or replaced with a FIFO 121 in SRS 105 , DRS 111 , Host Port 118 , and/or coupled to MII 116 interface and Utopia 114 interface.
SRS 105 issues a DMA request when one of the input FIFOs reaches a low water mark. When SRS 105 is ready to process a new frame of data, core 102 configures the block with all framing parameters, DMA parameters, and other controls and then starts the SRS 105 . From that point, SRS 105 operates independent of core 102 and fetches data from memory as needed. SRS 105 processes approximately one byte per system clock cycle. Thus, the only significant latency produced by SRS 105 is the latency produced by the interleaver function.
SRS 105 manages interleave memory 109 completely. More specifically, SRS 105 writes and reads samples using interleave memory 109 and provides them through a small FIFO to TRACTOR 107 . Interleave memory 109 is designed as a byte wide memory to simplify access for complex interleaver addressing modes. In the worst case, the bandwidth into and out of the buffer is a total of 25 MBs. Since core 102 has higher memory requirements for Training than Showtime and the interleaver is not active during Training, the 32 KB of interleave memory 109 is available for use by core 102 . Memory 109 can be accessed through the memory port of the SRS. Memory 109 appears as an 8K×32 memory block to core 102 .
TRACTOR 107 receives interleaved and non-interleaved data from SRS 105 and performs bit extraction, rotation, constellation encoding (with or without trellis), and tone ordering. TRACTOR 107 also includes circuitry for generating training symbols such as O/R-P-TRAINING, O/R-P-SYNCHRO, and O/R-P-MEDLEY as provided in the VDSL and ADSL specifications, as is known. In one embodiment, TRACTOR 107 includes a pseudo-random number generator and constellation rotator to assist in generating training symbols.
Processing in TRACTOR 107 occurs in bit order by first performing bit extraction and rotation and then performing constellation encoding. TRACTOR 107 performs tone ordering by writing to different locations in output memory. IFFT/FFT 108 sequentially receives data from TRACTOR 107 output memory. Thus, IFFT portion of IFFT/FFT 108 receives tone ordered data.
SRS 105 sends bytes to TRACTOR 107 . These bytes are received in TRACTOR input buffer 306 . TRACTOR input buffer 306 receives bytes and organizes the data into 16 or 32 bit words. TRACTOR input buffer 306 also serves to maintain data flow by preventing the different timing requirements of TRACTOR 107 and SRS 105 from causing excessive stalls.
In one embodiment, TRACTOR 107 processes low bit count constellations from the TRACTOR input buffer 306 before processing high bit count constellations from interleave memory 109 . Core 102 writes to bit load table 302 in tone order. The tables can be rearranged by core 102 in tone or bit order to enable a simplified or tone order configuration. TRACTOR input buffer 306 data passes to the constellation encoder. Depending on the path input to TRACTOR input buffer 306 , the processing of TRACTOR input buffer 306 will be dominated by the speed of the constellation encoder. Initially, the data with the fewest bits is sent first and TRACTOR 107 extracts multiple constellations from a byte of data. As constellation sizes grow, the SRS 105 operations adjust accordingly. For one path, when the higher bit loaded constellations of interleave memory 109 are processed, the processing time will be dominated by SRS speed. For the worst cases, TRACTOR input buffer 306 stalls will not dominate the processing because of the larger constellation size. In all cases, the delay through SRS 105 and TRACTOR 107 will be much less than a symbol period.
In multi-channel ADSL mode, SRS 105 and TRACTOR 107 functions must be shared between up to four channels. Each of SRS 105 and TRACTOR 107 completes an entire symbol of processing for one channel before moving to the next. In one embodiment, memory and other resources available for supporting VDSL are enough to support four ADSL channels with the exception of interleave memory 109 . ADSL channels can use more than the available 32 Kbytes of memory requiring external memory or core 102 memory to be used for the interleave function. After constellation encoding, TRACTOR 107 performs tone re-ordering and deposits the constellation points into TRACTOR output buffer 134 .
IFFT Functionality for Transmit
Referring now to FIG. 4 , a block diagram illustrates IFFT/FFT 108 functionality interactions for the transmit path. Specifically, TRACTOR output buffer 134 is coupled to transmit up to 1024 pairs of complex tones in 64 bits to IFFT engine 108 at a rate of about 64 bits per system clock to IFFT/FFT engine 108 . From IFFT/FFT engine 108 , data is transferred to and from FFT state ram 402 . Scaling table 404 is shown to store values such that each bin can be multiplied in the frequency domain, such that power is best allocated among the bins.
IFFT/FFT 108 operates on 4096 tones and copies data via point-to-point transfers from TRACTOR output buffer 134 into the correct transmit locations in internal memory based on a transmit and receive frequency map associated with the point-to-point transfers. IFFT/FFT 108 performs pre-scaling on the transmit tones during this transfer. In one embodiment, zeroing is accomplished by clearing all memory before an input transfer; writing to each of four banks at once; and clearing a state RAM in a number of clock cycles. The number of clock cycles can be 1024 or as system requirements dictate.
The output of IFFT/FFT 108 is transferred to transmit FIFO 126 at a bursting rate of about four 16-bit samples per clock. A 64 bit dedicated bus is used to limit the amount of FFT 108 processing time that is consumed by the transfer. Transmit FIFO 126 can be implemented as a single port RAM and the AFE interface 112 can require access to it once for every four AFE clocks. For the case where the system clock is four times the AFE clock the AFE interface will require a FIFO access once every 16 th system clock. In such a system, an IFFT output transfer can be configured to use 2176 clocks. The AFE 112 side of FIFO 126 requires a new sample every 16 system clocks because four samples are read from the FIFO per system clock and the system clock frequency can be implemented to be, for example, four times the sample clock. In other embodiments the engine 100 can be configured to be independent of an AFE 112 sample clock.
In the case of multiple ADSL channels, FIFO 126 is logically partitioned into multiple FIFOs with individual input/output pointers. The multiple FIFOs allow FFT coprocessor 108 to fill FIFO 126 in the same manner as VDSL. The AFE 112 side of FIFO 126 can read the data out from alternate channels on each system clock and send the data to the appropriate off chip AFE 112 . More specifically, AFE 112 can be configured to include a small, such as a four sample size FIFO on each channel. When an AFE 112 clock occurs for a channel, the channel can be considered as making a request for data. When a sample is requested from receive FIFO 130 , that channel can be considered as having a request serviced. The channel with the highest number of outstanding requests is the next to request data from FIFO 130 .
Transmit FIFO 126 contains hardware for performing cyclic prefix calculations. The cyclic prefix parameters (CE, CS, CP, and Beta) are fully configurable by core 102 . According to an embodiment, 2048 transfers occur for 8192 samples. IFFT/FFT 108 bursts an additional prefix extension making the size of the transfer depend on the cyclic extension size. Any size that is a multiple of four that is less than the transform size can be supported by an output transfer. For example, if the cyclic prefix and postfix extensions are 256 samples, then IFFT/FFT 108 starts the output transfer 256 samples before the end of the symbol. IFFT/FFT 108 transfers the last 256 samples, for example, four per clock, then transfers the entire symbol by wrapping back to address zero in FFT state memory. Finally, IFFT/FFT 108 transfers the 256 sample at the beginning of the symbol by wrapping to zero again. The wrapping to zero is accomplished by defining a starting logical sample address and a modulo value for the output transfer. The actual memory addresses can be calculated by applying digit reversal and then an appropriate algorithm, such as the FAST algorithm, which one of skill in the art will appreciate.
IFFT/FFT 108 can also assist the cyclic extension by transferring the data at the beginning of the symbol twice. In one embodiment, the two transfers include once at the beginning and once at the end. The Beta window as provided in the VDSL specification requires a table to store the window function. A FIFO can provide a separate register file for this purpose. Separate copies of the cyclic prefix parameters can be maintained for each ADSL channel in the register file since they are read out of the FIFO in a round robin fashion.
Core 102 is configured to be able to adjust the input and output pointers of FIFO 126 to perform symbol synchronization and timing advance. The TX FIFO 126 is sized at least 2.5 times the sample size to support the adjustment.
AFE 112 interfaces engine 100 to a VDSL AFE or up to four ADSL AFEs. AFE 112 can be designed to be flexible enough to support existing and future AFEs and support the data interfaces of multiple ADSL AFEs simultaneously. In addition to the data buses, a dedicated serial interface can be provided for use in controlling the AFEs. Thus, in one embodiment, AFE interface 112 can be configured to be flexible enough to support many devices.
In one embodiment, a programmable FIR engine is included for the transmit path at the front end of AFE interface 112 , shown as transmit time domain Co-Processor (TXCP) 110 . In another embodiment, TXCP 110 includes an FIR engine, a one to 32× interpolation stage, and a second FIR engine. In this embodiment, the additional components can be configured to support different specifications such as ADSL/2/2+ and to provide better digital filtering for VDSL.
Receive Path Operation
Referring now to FIG. 5 in combination with FIG. 1 , the receive path is shown in a block diagram. Like the transmit path, the receive path receives one 16-bit sample per sample clock, for example, from AFE 112 in VDSL mode. Received VDSL data is filtered by a TEQ filter in RXCP 129 before being stored in receive FIFO 130 . TEQ filter in RXCP 129 can be a 16 tap FIR that is calculated by RXCP (Receive Time Domain Co-Processor) 129 . RXCP 129 requires four multipliers to be able to calculate one TEQ output per 35.328 MHz clock. In VDSL Showtime operation RXCP 129 performs TEQ calculations in a serial fashion and writes its data to the receive FIFO 130 . However, for multi-channel ADSL modes RXCP 129 must perform calculations for up to four channels. Since ADSL sample rates are much lower, RXCP 129 requires no additional processing capabilities. However, RXCP 129 needs additional memory for the TEQ filter delay lines and coefficients.
In an embodiment, RXCP 129 can be configured to include a decimator, and FIR engine, a second decimator, and a second FIR engine to perform time domain equalization.
Like transmit FIFO 126 , receive FIFO 130 is implemented as a single port 64 bit wide ram. Receive FIFO 130 is configured with read and write pointers that are controllable by core 102 for use in symbol alignment. FIFO 130 can also be programmed to discard the cyclic prefix and can be logically partitioned into four FIFOs for multi-channel mode. After symbol synchronization is achieved, receive FIFO 130 can generate a symbol rate timing signal by comparing the number of input samples received to a core 102 defined threshold. The symbol rate timing signal defines the symbol boundary that can be used to trigger the FFT operation. For a normal symbol, core 102 is configured to adjust the FIFO pointers to effectively discard any cyclic extension (prefix and postfix). In engine 100 , symbol synchronization occurs once during training. During training, a timing change occurs between the receiver components and the transmit components. IFFT/FFT 108 has a fixed processing time, thus to line up timing components and allow IFFT/FFT 108 and other components to complete operations, symbol times are extended. Transmit FIFO 126 is configured to contain enough data to continue to supply AFE 112 during such an extension, up to one symbol.
FFT For Receive Functionality
Referring to FIG. 1 in combination with FIG. 5 , when IFFT/FFT 108 is available for performing an FFT, a symbol of data (8192×16) is burst transferred into IFFT/FFT 108 on a dedicated 64 bit bus. Similar to the transmit path, single-ported receive FIFO 130 causes the burst to lose cycles while TXCP 110 is writing the FIFO 130 . The cyclic prefix data is discarded by the FIFO logic and not transferred to FFT engine 502 within IFFT/FFT 108 . FFT engine 502 needs about 12000 cycles (including TX FIFO 126 input transfer) to perform the FFT and another 1024 to write the results to FCP 113 . FFT engine 502 takes advantage of the idle butterfly hardware to perform output scaling using scaling table 504 during the output transfer. Only the active receive tones are transferred, based on a TX/RX frequency map, which can be implemented as a set of registers in the IFFT/FFT 108 . The system clock can be run independent of the AFE sample clock in one embodiment, or can be run as dependent on the AFE sample clock, according to system requirements which can be appreciated by one of skill in the art. The time can be used for DMA access to the FFT state memory or scaling tables. The time may not be enough to DMA transfer the complete state memory of the FFT block if FFT/IFFT processing must continue at the symbol rate. However, the active bins can be DMA transferred out of the FCP 113 , instead or the state memory can be transferred using a core 102 memory copy. Core 102 controlled memory can copy one word per clock while DMA transfers require two clocks per word.
Referring now to FIG. 6 , receive paths through decoder 106 are illustrated. FFT output transfers are transmitted to decoder 106 FCP buffer 134 via point-to-point bus 270 . FFT output transfers have the highest priority for access to the FCP buffer 134 . Therefore, the FFT transfer will not be stalled by other FCP operations. FCP 113 is triggered to begin processing by core 102 or by the completion of the FFT transfer. FCP 113 performs the FEQ filtering (including filter training), slicing, Viterbi decoding, SNR calculations, and framing. To save processing time and hardware requirements the FCP 113 only operates on the active bins for the receive direction. FCP 113 performs reverse tone ordering as it reads the data out from buffer 134 . Therefore, the complex points are fetched from the buffer in the order they need to be reassembled to form a de-interleaver bit stream. FCP 113 is coupled to de-interleaver memory 115 , to pass data to DRS 111 . To facilitate training symbol recovery, in one embodiment, FCP 113 also has a pseudo-random number generator and tone rotator.
FCP 113 can be implemented as a specialized complex data processor that is capable of performing all FEQ, SNR, and slicing operations. FCP 113 can contain its own program space that is written by core 102 . Since FCP 113 works on one frequency bin at a time, it normally discards partial results and does not require a lot of temporary storage RAM. However, it can be programmed to load partial results, such as FEQ calculations, and the like, into the FCP input buffer 132 for access by core 102 . FCP 113 is coupled to bit load table 602 that can include signal to noise ratio memory and coefficient memory.
To guarantee that decoder 106 completes in one sample period FCP 113 is configured to complete its operations in about 75% of a sample period. For VDSL, that equates to 13 clocks per frequency bin in the worst case. Other decoder functions can occur in parallel with FCP 113 operations once enough data is available to start the pipelines.
When FCP 113 has re-assembled the bit stream it writes the data into a DRS input FIFO 608 via a point-to-point transfer. DRS input FIFO 608 is needed, in part, because the FCP 113 output is bursty while DRS 111 operation is pipelined. The front end of DRS 111 pipeline can be configured as a de-interleaver. De-interleave memory 115 is available for use by core 102 during training in the same fashion as SRS 105 interleave memory. DRS 111 can also perform Reed-Solomon decoding, CRC checking, and de-scrambling. The de-interleave function is performed by the addressing logic as data is fetched for Reed-Solomon decoding. Unlike the Reed-Solomon encoder, decoder 106 needs to have access to a full code word of data in case it needs to make corrections. Therefore, the Reed-Solomon decoder has a local 256 byte buffer 606 to hold the maximum sized Reed-Solomon code word. Reed-Solomon decoder in DRS 111 can be configured to wait for an entire codeword from input FIFO 608 to be available in the de-interleaver before starting the decode because a symbol of data does not necessarily contain an integer number of code words. Otherwise, temporary storage would be required to save the state in multi-channel mode.
In one embodiment, DRS input buffer 608 is treated like a FIFO with programmable watermarks. The watermarks can be used to trigger the FCFS circuitry for the DRS and select the next channel for processing. The watermarks can be configured to trigger when a codeword is available and is set to indicate a size, for example, for a full codeword for each channel.
After any corrections are made the data is de-scrambled. Cyclic redundancy check (CRC) checks are performed at superframe boundaries and for the VDSL overhead control channel (VOC) and other the fast bytes are extracted and stored in FIFOs for core 102 accesses. DRS 111 further includes de-framing logic with the same degree of programmability as the framer in SRS 105 . The final output of the block is DMA transferred to core 102 memory or directly to the interface FIFO. When data is sent to core 102 memory, another DMA transfer will be required to move it to the interface FIFOS.
Peripheral Memory Map
Referring now to FIG. 2A , engine 100 uses distributed processing and much of the memory is distributed as well. As shown, each peripheral processor module, including FFT/IFFT 108 , encoder 104 , decoder 106 , TX FIFO 108 , TXCP 110 , AFE 112 , RXCP 129 and RX FIFO 130 , can be configured to include local RAM and/or ROM. If all of these memories were mapped directly into engine 102 X/Y data space the clock rate of the device would be limited by the speed of those data buses. Also, if local memories are 32 bits wide, such a configuration makes it difficult to directly map them into the 24 bit data buses. To avoid these issues, local memories are configured to be indirectly mapped using a memory port 250 located in each peripheral module. Memory ports 250 provide core 102 access to all memories on engine 100 . More particularly, as shown, each of the memory ports 250 are coupled to bus 280 . The ports 250 can be designed to provide full speed access to the memories for block data transfers. Also shown in FIG. 2A , are direct connections 290 for purposes of testing. Direct connections 290 are shown between encoder 104 and decoder 106 ; and shown between RXCP 110 and RXCP 129 .
Each memory port 250 can be configured to include an X or Y peripheral I/O mapped address and data registers and an associated state machine. An address register can be used to specify the address for access within a local memory as well as an optional auto-increment or auto-decrement function. A data register can be used by core 102 as the data interface for all reads and writes to the local memory. When the Address register is written by core 102 , the state machine issues a read to the local memory and stores the memory output in a Data register. Core 102 can then read that memory location by reading the Data register. If the Address register is setup for auto-increment or auto-decrement then each core 102 read to the Data register will update the Address register and cause another local memory read. Since the data is always pre-fetched in anticipation of a read, the Data register can be read on every core 102 cycle after the Address register is setup. The operation is the same for writes except that the core 102 can issue a write to the Data register. Therefore, block transfers to peripheral memories via ports 250 can occur at the full speed of core 102 data buses. However, each random access to the memories requires a write to an Address register, then a cycle for pre-fetch, and finally an access to the Data register. Therefore, the random access bandwidth of the peripheral memories is about ⅓ of the core 102 data bus speed.
In an embodiment, peripheral memories are 32 bits wide and the memory port state machine maps 32 bit data into 24 bit core 102 buses. Two core 102 bus transactions can be used to transfer each 32 bit word. Accesses to even addresses affect the 16 MSBs of the 32 bit word and odd addresses affect the 16 LSBs. The 16 bit quantities are packed into the MSBs of the 24 bit word and the 8 LSBs are padded with 0s. Since two core 102 writes are required to update each memory location, the local memory write cycle will only occur after the second (odd) location is written.
The following table lists all of the distributed memories in engine 100 and shows how they are mapped into each peripheral's memory port 250 address space. As shown, the memories are addressed as 16 bit quantities and the Start and End addresses are the values that would be written to the Address register for that module.
TABLE 1
Start
End
Module
Memory
Size
Address
Address
FFT
State RAM 0
1K × 32
0000
07ff
State RAM 1
1K × 32
0800
0fff
State RAM 2
1K × 32
1000
17ff
State RAM 3
1K × 32
1800
1fff
FFT Post-Scale RAM
1K × 32
2000
27ff
IFFT Pre-Scale RAM
1K × 32
2800
2fff
Twiddle ROM 0
512 × 32
3000
33ff
Twiddle ROM 1
512 × 32
3400
37ff
SRS
Interleaver RAM
8K × 32
0000
3fff
DRS
De-Interleaver RAM
8K × 32
0000
3fff
Input FIFO
1K × 32
4000
47ff
TRACTOR
State RAM 0 & 1
3072 × 32
0000
17ff
1536 × 32 RAMS
interleaved addr.
FCP
State RAM 0 & 1
10240 × 32
0000
4fff
5120 × 32 RAMS
interleaved addr.
Reserved
6144 × 32
5000
7fff
Program RAM
512 × 32
8000
83ff
FIFO
RX FIFO RAM 0 & 1
7168 × 32
0000
37ff
3584 × 32 RAMs
interleaved addr.
FIFO Coefficient
64 × 32
4000
407f
RAM
Reserved
8160 × 32
4040
7fff
TX FIFO RAM 0 & 1
12288 × 32
8000
dfff
6144 × 32 RAMs
interleaved addr.
MUT
TX FIFO
4K × 32
0000
1fff
RX FIFO
4K × 32
2000
3fff
System Timing in Showtime
Referring now to FIG. 7 , a timing diagram illustrates that in VDSL or ADSL Showtime operations, the system is synchronized to a symbol timing signal of approximately 4 kHz. In the case of a customer premise equipment (CPE) modem, the symbol timing signal is extracted from the received symbols. For the central office (CO), the timing signal may be produced by dividing down a sample clock or by sampling an external timing reference.
In an embodiment, engine 100 provides that the system is timed around an event that is synchronous but out of phase with this signal by using the FFT completion interrupt. FFT completion is viewed as the start of symbol for system control purposes. This event was chosen because it is somewhat fixed in time due to the limited resources for performing FFTs and IFFTs.
Referring now to FIG. 7 , timing diagrams illustrate the system timing for VDSL. For four-channel ADSL mode the diagram is similar but runs at four times the symbol rate. FIG. 7 illustrates the end of FFT processing 702 , which also marks a start of a symbol period 704 . F blocks 706 represent times during which the FFT coprocessor is transferring data to and from FIFOs. During these times, the coprocessors that write and read the FIFOs must be idle. This requirement allows the FIFOs to use single-ported RAMs. Encoder 104 and decoder 106 each have a symbol period or FIFO time in which to process a frame of data. To keep hardware buffering to a minimum, SRS 716 and TRACTOR 712 operate on the same data frame, as shown. Since the TRACTOR requires data from the SRS it can only process when data is available. Therefore, there is a delay shown as the difference between RS encode frame 718 and CE encoding startup 714 to prevent possible pipeline stalls when data is not available. A similar situation exists for the FCP and DRS, as shown by the difference between FCP 708 and DRS 710 .
In one embodiment, RX FIFO 130 includes a programmable watermark that sets a watermark that can enable a programmable skew between the watermark and beginning of operations of encoder 104 . When a watermark is set, the timing reference becomes the watermark and replaces the FFT completion timing reference. When RX FIFO contains a full symbol, operations can begin.
FFT Functionality
Referring now to FIG. 8 in combination with FIG. 1 , an embodiment is directed to systems and methods associated with IFFT/FFT 108 . In general, IFFT/FFT co-processor 108 calculates FFT and IFFT transforms for a DMT data pump. FIG. 8 provides a block diagram of components within IFFT/FFT 108 , including a state RAM 802 coupled to receive generated addresses for FFT calculations from address generation unit (AGU) 804 . AGU 804 is further responsible for transfers between state memory and external modules location addresses and generates addresses for the state RAM 802 based on transmit and frequency map 806 . Blocks 804 and 806 are coupled to DMA and point-to-point bus interfaces 808 . DMA and point-to-point bus interfaces 808 are coupled to radix-8 butterfly 810 and to scaling tables 812 .
IFFT/FFT 108 performs FFT, IFFT, IFFT pre-scaling, FFT post-scaling, and frequency mapping and format conversion. Some operations occur during data transfers, including frequency mapping (IFFT in, FFT out), IFFT pre-scaling, FFT post-scaling, IFFT post-scaling with one scale value per symbol, and number format conversion (fixed to floating point for input, and floating point to fixed for output).
In an embodiment, IFFT/FFT 108 is in use for approximately 30000 clock cycles during a sample period. To achieve this speed, IFFT/FFT 108 can incorporate a programmable radix-8 hardware butterfly 810 , shown in detail in FIG. 9 .
As shown in FIG. 8 , state RAM 802 can be configured to hold four banks of 1024 complex samples, each complex sample being 32 bits in length, which can be organized with 16 bit-wide real and imaginary parts therein. State RAM 802 receives addresses and control signals from AGU 804 , the addresses of which determine the data fed to the radix-8 butterfly 810 . Transmit and receive frequency map 806 stores which FFT outputs are used for transmit and which FFT outputs are used for receive operations. Both AGU 804 and transmit and receive frequency map 806 interact with DMA and point-to-point bus interfaces 808 to receive instruction from core 102 . Additionally, the amount of data transferred over interfaces 808 is tracked for control purposes.
Butterfly 810 can be configured to calculate one complex radix-8 butterfly per 4 clocks. State RAM 802 and butterfly 810 have four buses there between. Two of the four buses 816 transmit two complex samples to butterfly 810 . Two of the four buses 816 transmit complex samples to state RAM 802 . Butterfly 810 transmits and receives samples to and from DMA and point-to-point bus interfaces 808 . More specifically, data received by interfaces 808 is scaled in butterfly 810 prior to transfer to and from state RAM 802 .
Butterfly 810 further interacts with scaling tables 812 , which can be configured with 2048 16 bit wide locations for holding scaling factors for use during FFT processing, and 2048 16 bit wide locations for holding scaling factors for use during IFFT processing. The scaling factors can be used to multiply each data point before or after IFFT and FFT processing. Scaling tables 812 are coupled to DMA and point-to-point bus interfaces 808 allowing the scaling factors to be written by core 102 .
DMA and point-to-point bus interfaces 808 provide a method to write and retrieve data and control information to butterfly 810 , scaling tables 812 and AGU 804 from other components in engine 100 , such as core 102 , TRACTOR 107 , FCP 113 , RX FIFO 130 and TX FIFO 126 . To control butterfly 810 and scaling tables 812 , an embodiment provides for a control bus 814 . DMA and point-to-point bus interfaces 808 enable the DMA and point-to-point buses to both supply data. In one embodiment, a peripheral bus provides primary control and the point-to-point bus provides an “active” signal to also provide some control. IFFT/FFT 108 listens for an active signal to determine when there is data available from the source (RXF or TRACTOR). IFFT/FFT 108 can be programmed to start running when that signal goes active. In one embodiment point-to-point input “active” signals could occur at the same time or in different orders. To better support an Automatic mode, IFFT/FFT 108 can be programmed to take the first available or to always toggle between running an FFT and an IFFT.
Butterfly 810 and state RAM 802 implement an in-place FFT algorithm and floating point calculations to reduce memory requirements, thereby overwriting prior calculations stored in state RAM 802 . Beneficially, an in-place FFT algorithm and floating point usage limits internal state memory, state RAM 802 , to 4096 complex samples of 32 bits each. The 4096 complex samples are separated into four banks of 1024 samples each to provide the memory bandwidth required by butterfly 810 . During FFT calculations, the butterfly hardware reads two complex samples and writes two complex samples per clock as shown by buses 816 .
According to an embodiment, during input and output data transfers all samples are passed through the butterfly logic before being written to state RAM 802 . Requiring all samples to pass through the butterfly logic prior to being written to state RAM 802 allows the butterfly to efficiently apply scaling coefficients as the data is read from or written to state RAM 802 .
To provide sufficient data to the butterfly on every clock cycle, a complex memory organization and addressing scheme can be employed. AGU 804 is responsible for generating the addresses for FFT calculations and for transfers between state memory and external modules. During FFT processing, AGU 804 generates two read and two write addresses per clock cycle. The read and write addresses are applied to four state memory banks 802 . During external module data transfers, AGU 804 can translate incoming/outgoing sample index into a state bank and RAM address. All state memory transfers except DMA involve pairs of samples. Thus, AGU 804 can perform two translations per clock.
IFFT/FFT 108 is used by both transmit and receive data paths and can have dedicated point-to-point buses 808 for both paths. For the transmit path, IFFT/FFT 108 receives data that was encoded in TRACTOR 107 via output FIFO 134 and sends data to transmit FIFO 126 . For the receive path, IFFT/FFT 108 receives data from the RX FIFO 130 and writes it to the FCP 113 at input FIFO 132 . Point-to-point buses 270 can be sized at 64 bits so that they can carry two complex samples and four real samples per clock. The bandwidth avoids having IFFT/FFT 108 spend excessive time doing data transfers and avoids requiring dual port RAMs in the input and output FIFOs 132 and 134 .
According to an embodiment, the central location of IFFT/FFT 108 is used to enable the buses 270 and DMA 122 useful for data routing requirements other than the normal Showtime data flow. Therefore, the bus interfaces 808 of IFFT/FFT 108 are capable of performing a loop back from TRACTOR 107 to the FCP interface 113 . More specifically, as shown in interfaces 808 , TRACTOR 107 and FCP 113 can be directly coupled through interface 808 for testing frequency domain components in isolation outside of Showtime.
The IFFT/FFT 108 interfaces 808 includes a DMA interface that can be used to transfer data to/from any internal memory on engine 100 . In one embodiment, DMA bus is logically connected to all memories. Therefore, a transfer can occur between the FFT and X/Y/P RAM, or the FFT and the RAM in another peripheral block. In an embodiment, IFFT/FFT 108 can be configured to be idle during state data transfers if internal memories are not dual ported.
Core 102 access to the FFT coprocessor 108 can be accomplished using program controlled I/O or DMA. In either case, the module appears as a set of registers to core 102 . Rather than memory mapping the FFT coprocessor's local memory in core 102 , an embodiment provides memory access port 818 via DMA and peripheral bus interfaces. More specifically, the peripheral bus interface is used when core 102 accesses a memory mapped register using a peripheral input/output interface. To core 102 , memory access port 818 appears as a set of memory mapped registers. The access port simplifies the integration of IFFT/FFT 108 into engine 100 without significant reduction in memory bandwidth for burst transfers.
In one embodiment, bus interface 808 includes peripheral input/output registers 820 that are used by IFFT/FFT 108 as part of the standard interface capable of interfacing with one or more of co-processors 104 , 106 , 108 , 110 , 112 and 129 . The interface can be implemented as a programmer's interface that shares qualities for each coprocessor. Input/output registers 820 can include a control register to hold general controls such as reset and interrupt enables; a status register can contain interrupt and other status information. The Memory Port registers 818 can be used to provide core 102 access to the IFFT/FFT 102 internal memories.
In one embodiment, IFFT/FFT 108 includes an auto-increment and other like addressing modes to facilitate DMA block transfers through memory access port 818 . The configuration register holds module specific configuration information such as the FFT size and radix.
In an embodiment, IFFT/FFT 108 is configured to hold five memory instances mapped into the address space of memory port 818 , which can be four 1Kx32 and one 2Kx32. Logically, the four 1Kx32 memories can be configured as state memory mapped into the memory port address space as one sequential 8Kx16 memory. Similarly, the 2Kx32 scale factor memory can be mapped into a sequential 4Kx16 address range. IFFT/FFT 108 can also be configured with two 512×32 ROMs mapped into memory port 818 address space for testing purposes. Memory port 818 address map can vary depending on the number of channels that IFFT/FFT 108 is configured to process as shown in the following tables.
TABLE 2
Memory Port Address Map - 1 channel
Name
Size
Start Address
End Address
State Ram 0
2K × 16
0000
07ff
State Ram 1
2K × 16
0800
0fff
State Ram 2
2K × 16
1000
17ff
State Ram 3
2K × 16
1800
1fff
FFT Post-
2K × 16
2000
27ff
Scale Ram
IFFT Pre-
2K × 16
2800
2fff
Scale Ram
Twiddle ROM 0
1K × 16
3000
33ff
Twiddle ROM 1
1K × 16
3400
37ff
TABLE 3
FFT Memory Port Address Map - 2 channel
Name
Size
Start Address
End Address
State Ram 0
2K × 16
0000
07ff
State Ram 1
2K × 16
0800
0fff
State Ram 2
2K × 16
1000
17ff
State Ram 3
2K × 16
1800
1fff
FFT Post-
1K × 16
2000
23ff
Scale Ram-
Channel 0
FFT Post-
1K × 16
2400
27ff
Scale Ram -
Channel 1
IFFT Pre-
1K × 16
2800
2bff
Scale Ram -
Channel 0
IFFT Pre-
1K × 16
2c00
2fff
Scale Ram -
Channel 1
Twiddle ROM 0
1K × 16
3000
33ff
Twiddle ROM 1
1K × 16
3400
37ff
TABLE 4
FFT Memory Port Address Map - 4 channel
Name
Size
Start Address
End Address
State Ram 0
2K × 16
0000
07ff
State Ram 1
2K × 16
0800
0fff
State Ram 2
2K × 16
1000
17ff
State Ram 3
2K × 16
1800
1fff
FFT Post-
512 × 16
2000
21ff
Scale Ram -
Channel 0
FFT Post-
512 × 16
2200
23ff
Scale Ram -
Channel 1
FFT Post-
512 × 16
2400
25ff
Scale Ram -
Channel 2
FFT Post-
512 × 16
2600
27ff
Scale Ram -
Channel 3
IFFT Pre-
512 × 16
2800
29ff
Scale Ram -
Channel 0
IFFT Pre-
512 × 16
2a00
2bff
Scale Ram -
Channel 1
IFFT Pre-
512 × 16
2c00
2dff
Scale Ram -
Channel 2
IFFT Pre-
512 × 16
2e00
2fff
Scale Ram -
Channel 3
Twiddle ROM 0
1K × 16
3000
33ff
Twiddle ROM 1
1K × 16
3400
37ff
In an embodiment, IFFT/FFT 108 is equipped with a low-power gated clock mode, which can be implemented with either an AND gate or an OR gate, for example coupled to a clock. Setting the soft reset bit of the control register will prevent any clocked circuits downstream from the clock gating logic from receiving transitions on the clock. Thus, all logic can be reset and will use minimal power due to the removal of the clock.
During Showtime operation, in one embodiment IFFT/FFT 108 can perform 4000 FFT and 4000 IFFT transforms per second. Rather than performing an 8192 point real to complex FFT, the architecture for IFFT/FFT 108 can provide for splitting the input into a real portion and an imaginary portion and perform a 4096 point complex FFT to reduce the number of operations required by approximately one half. The reduction is accomplished by performing 4096 point complex transforms and then post-processing the results to produce the required 8192 points. Thus, the required local storage is also reduced by one half. For IFFT processing, the input is also split into a real portion and an imaginary portion, resulting in a reduction in approximately of have of the number of operations.
In one embodiment, a clock appropriate for engine 100 can be a 141.312 MHz clock. As a result, IFFT/FFT 108 requires at least six hardware math units. In the embodiment, as shown in FIG. 9 , a pipelined hardware butterfly is used to perform the math units.
According to one implementation, for each 250 μs symbol period there are 35,328 clock periods available for FFT/IFFT processing. In the implementation, butterfly 900 performs a single transform in about 10,000 clocks using a radix-8 butterfly 900 . There are a number of ways that the radix-8 calculations could be scheduled across multiple clocks. Since there are 24 complex adds and nine complex multiplies per butterfly a four cycle butterfly requires at least six complex adders and 2.25 complex multipliers implemented as two complex multipliers and one real multiplier. In an embodiment, a minimal amount of hardware is used by having butterfly 900 vertically sliced across four logical time slices. Thus, the first time slice calculates (a 0 , a 4 , b 1 , b 3 , c 1 , c 5 ) in block 902 , the second calculates (a 2 , a 6 , b 1 , b 3 , c 0 , c 4 ) in block 904 , the third calculates (a 3 , a 7 , b 0 , b 2 , c 2 , c 6 ) in block 906 , and the fourth calculates (a 1 , a 5 , b 4 , b 6 , c 3 , c 7 ) in block 908 . Using vertical slicing keeps the six adders busy on every clock cycle but slightly under utilizes the multipliers. A temporary storage register shown as 1014 and 1020 in FIG. 10 at all locations in butterfly 900 where the arrows cross clock boundaries. However, the registers can be shared across multiple clocks so that only 12 are needed.
Butterfly 900 illustrates a simplified representation of the radix-8 butterfly pipeline. The maximum number of hardware elements required in any one block of butterfly 900 includes six complex adders and three complex multipliers. As shown, butterfly 900 illustrates different hardware configurations in blocks 902 , 904 , 906 , and 908 . The operations are scheduled over the blocks 902 , 904 , 906 , and 908 over multiple clock cycles. The pipeline is started once per FFT stage and operates continuously over 512 butterflies in order to perform a 4096 point FFT or IFFT. Although there is an initial delay while the pipeline is filled, the throughput of the pipeline is one butterfly per four clocks.
The pipeline accepts data in fixed point or floating point data formats. In one embodiment, format converters are provided for use at one or both of the beginning and ending of pipeline processing to provide flexibility. The format converters enable pipeline operations to occur in a floating point format with a four bit exponent and a mantissa that gains precision after each math operation. In an embodiment, rounding can occur at the end of the pipeline.
In one embodiment, butterfly 900 can be configured to alter the order of the additions and multiplies in Stage 3 such that they can be reversed to better support FFT/IFFT fold calculations. Also, j multipliers 910 can be applied to the register outputs to alter the sign of outputs and exchange real and imaginary components. Additional pipeline features can be controlled by microcode. Up to four pipeline instructions can be used to control the pipeline on consecutive clocks. The four instructions can be repeated continuously during the processing of an FFT/IFFT stage. In one embodiment, butterfly 900 can perform a radix-2 and radix-4 which require fewer microcode instructions. Referring to FIG. 10 , in one approach, a radix-4 requires the use of blocks 1016 , 1018 , 1022 , and 1024 and only two cycles of microcode instructions. For a radix-2, butterfly 900 uses blocks 1022 and 1024 and requires one microword instruction. To implement the alternative radix operations, an embodiment provides for a “no operation” (NOP) for portions of butterfly 900 that are not required.
Referring now to FIG. 10 in combination with FIG. 9 , a scheduling diagram 1000 illustrates hardware to perform an exemplary vertical slice as shown in FIG. 9 , blocks 902 , 904 , 906 and 908 . FIG. 10 further illustrates that several partial products must be saved in a register, such as register 1020 , for later use. The data flows from state RAM 1002 through two 32 bit buses into registers x, 1004 and x n+4 , 1006 and then to a complex adder 1008 and complex subtractor 1010 . Data from complex subtractor 1010 is multiplied at multiplier 1012 by e jπ/4 . The data is then provided to a register bank 1014 as shown. As shown, each register holds a different partial product. Register bank 1014 is coupled to complex adder 1016 and complex subtractor 1018 , which operate on the partial products in register bank 1014 . The outputs of complex adder 1016 and complex subtractor 1018 are provided to register bank 1020 .
Register bank 1020 illustrates that partial products b 1 , b 3 , b 4 and b 6 are present in two registers. Data is output from register bank 1020 and provided to complex adder 1022 and complex subtractor 1024 . Outputs of each adder 1022 and subtractor 1024 are then multiplied in respective multiplier 1026 and 1028 , by respective ROM coefficients 1030 and 1032 . Outputs of multipliers 1026 and 1028 are then provided to registers 1034 and 1036 , which are each coupled back to state RAM 1002 . Between registers 1034 and 1036 , write cache 1035 and state RAM 1002 , which operates to provide data to registers 1034 and 1036 .
Referring to ROM coefficients 1030 and 1032 , an embodiment provides for including 512 entries in each of ROM 1030 and 1032 . Using two ROMs allows two multiplies to occur in a single clock period. Although for much of FFT and IFFT processing ROMs 1030 and 1032 require 4096 entries, symmetry between the ROMs is applied to prevent redundant entries and reduce the number. According to an embodiment, for a 8192 point transform, such as for fold stages of processing, and the like, one entry from each of ROMs 1030 and 1032 are retrieved and interpolated to produce interpolated entries to enable the 8192 point transform.
As a result of the hardware described with reference to FIG. 10 , the b 6 partial product, for example, must be saved in a register for five clocks. In an embodiment, a control is provided that addresses the need to expand on a four clock operation. A simple toggle register is used to toggle the addressing and cause the b 4 and b 1 values to alternate between registers 3 and 5 and the b 4 and b 6 values to alternate between registers 4 and 6 . The operation of the toggle bit is controlled by instructions.
The radix-8 butterfly hardware reads two complex samples and writes two complex samples per clock. The four samples accessed on each cycle are configured to reside in separate memory banks to avoid needing dual port RAMs. The memory organization is further complicated by the data transfers between external blocks and state RAM. These transfers operate on sequential pairs of samples. To allow these transfers to occur at full speed, the even and odd samples are stored in separate memory banks via discarding bit 1 of a bit of a bank number calculated via an algorithm, such as the FAST algorithm. Bit 1 of the original address is used as part of the bank address. The IFFT pre-processing and FFT post-processing stages also put requirements on the memory organization. The following table summarizes the memory bank requirements. The table shows the indices of samples that must be stored in different memory banks for each stage of processing. Each cell in a row represents a separate memory bank. The cells within a column do not necessarily need to belong to the same memory bank. The tables assume application of the Sande-Tukey or decimation in frequency method.
TABLE 5
Memory Bank Requirements
Separate Memory Banks
FFT Stage 0
N
N + 4 (512)
N + 1 (512)
N + 5 (512)
N = 0 to
N + 2 (512)
N + 6 (512)
N + 3 (512)
N + 7 (512)
511
FFT Stage 1
N
N + 4 (64)
N + 1 (64)
N + 5 (64)
N = 0 to 63
N + 2 (64)
N + 6 (64)
N + 3 (64)
N + 7 (64)
FFT Stage 2
N
N + 4 (8)
N + 1 (8)
N + 5 (8)
N = 0 to 7
N + 2 (8)
N + 6 (8)
N + 3 (8)
N + 7 (8)
FFT Stage 3
N
N + 4
N + 1
N + 5
N = N + 8,
N + 2
N + 6
N + 3
N + 7
N < 4096
Pre/Post
N
4096 − N
process
N = 1 to
4095
Data
N
N + 1
transfers
For example, when N=0 the table shows that the samples in the following groups must reside in different memory banks: (0, 2048, 512, 2560), (0, 256, 64, 320), (0, 32, 8, 40), (0, 4, 1, 5), (2, 4094), and (0,1).
According to an embodiment, a method for addressing the memory banks is shown in FIG. 11 . More particularly, FIG. 11 provides a method for the addressing for a radix-8 FFT using eight memory banks. Block 1110 provides for expressing an index in radix-8 notation: I=I(3)*512+I(2)*64+I(1)*8+I(0). Block 1120 provides for computing the bank address for an eight bank memory: B=(I(3)+I(2)+I(1)+I(0)) modulo 8. Block 1130 provides for converting the bank address to a four bank memory by ignoring bit 1 : B=(b 2 b 1 b 0 ), B 4 =(b 2 b 0 ), and saving bit 1 for use as bit 0 of an A address. Block 1140 provides for calculating the address within the bank: A=I/4. In one embodiment, bits are concatenated as follows: A={I[11:3],I[1]}. Thus, A=((Integer(I/8))*2)+((Integer(I/2)) mod 2).
Referring now to FIG. 12 , table 1200 illustrates partial results during different stages of FFT and IFFT processing, RAM read access entries 1202 , Stage 1 calculations 1204 , Stage 1 storage 1206 , Stage 2 calculations 1208 , Stage 2 storage 1210 , Stage 3 Calculations 1212 , and RAM write access 1214 . As table 1200 illustrates, bank reduction is effective because samples separated by 2, 2*8, 2*64, and 2*512 can reside in the same bank. All calculations are power of two and thus involve simple bit manipulation independent of math blocks.
During butterfly and fold processing, a same memory bank may need multiple accesses during one cycle. When this occurs for the two read operations, the pipeline is stalled by one clock so that both values can be accessed. However, an addressing conflict is uncommon and performance reduction is negligible.
A more common conflict occurs when read and write or multiple writes access the same memory bank. To avoid a large performance penalty, an embodiment is directed to providing a write cache. The cache can store up to eight pending memory writes. During normal processing, the cache controller determines which memory banks are available for writing by verifying that the same banks are not being read. If the data coming from the pipeline is destined for an available bank then it is written directly to memory. If not, then it is written to the cache. During the same cycle the cache controller will write any data that is in the cache that is destined for an available memory bank. On occasion the cache will become full. In that case the controller stops the pipeline and flushes the entire cache.
Each memory location holds a complex sample using 32 bits of data. The sample can be in a fixed point format with 16 bits for the real value and 16 bits for the imaginary or one of two floating point formats. The first floating point representation (FP2) uses two bits for the exponent and 14 bits for the mantissa for both the real and imaginary values. The second format (FP4) uses 14 bits for each mantissa and a shared four bit exponent.
The data pipeline performs all floating point operations using a four bit exponent and a mantissa that grows in size from the front of the pipeline to the back. Data converters at the front and back of the pipeline allow the data to be read and written in any of the supported formats. Normally, the input transfers are fixed point but are converted to FP2 before being written to memory and the output transfers are also fixed point. All other operations required for FFT/IFFT processing use the FP4 format for storing temporary values.
The radix-8 pipeline is largely a fixed structure. However, some amount of programmability is required to allow the structure to be used for radix-8 butterflies, IFFT pre-processing, FFT post-processing, and state memory transfers. Rather than using hardcoded execution modes, a set of microcode registers are provided that control the pipeline dataflow. When combined with a programmable address generation unit this strategy allows the FFT algorithm to be modified or pipeline to be used for non-FFT calculations. Adding this capability does not significantly increase the size of the pipeline but makes the FFT coprocessor more flexible.
The tables provided below describe the datapath microde registers.
TABLE 6
Reset/
Bit
power-
(s)
Name
R/W
on
Description
23:21
Reserved
R/W
3′h0
Reserved
20:19
Stage C -
R/W
2′h0
Opcode for the stage C
Complement
complementors.
Opcode
2′h0 = NOP
2′h1 = Complement adder output
2′h2 = Complement subtractor
output
3′h3 = Auto complement based on
transform, adder for FFT,
subtractor for IFFT
18
Stage C
R/W
1′h0
Setup stage C for fold
Fold
processing. The order of the
adders and subtractors are
swapped.
17
Stage C
R/W
1′h0
When set the output of the
Swap
stage C adder and subtractor
are swapped before being used
by the next math block.
16:14
Stage C
R/W
3′h0
Selects two of the eight stage
Input
B registers into the front of
the stage C pipeline. The
selection is encoded into three
bits to save microcode space.
The three bits determine both
read addresses as follows:
Normal
Munged
Code
Addresses
Addresses
3′h0
0, 4
0, 2
3′h1
1, 5
1, 3
3′h2
2, 6
4, 6
3′h3
3, 7
5, 7
3′h4
0, 1
0, 1
3′h5
2, 3
2, 3
3′h6
4, 5
4, 5
3′h7
6, 7
6, 7
13:12
Stage C
R/W
2′h0
Opcode for stage C
Opcode
adder/subtractor
2′h0 = NOP
2′h1 = Add operand 0 to 1 and
subtract operand 1 from 0
2′h2 = Add operand 0 to 1 and
subtract operand 0 from 1
3′h3 = Same as 2′h1 but the
(0, j) multiplier is also
applied to operand 1 before
add/subtract
11
Stage B
R/W
1′h0
When set the output of the
Swap
adder and subtractor are
swapped before being written
into the stage B registers.
10
Stage B
R/W
1′h0
Affects the input and output
Munge
addressing of the stage B
registers. The munge bit
toggles a state bit that
controls the addressing. This
is needed to allow some stage B
values to be retained for more
than four clocks using only
four microwords.
9:8
Stage B
R/W
2′h0
Selects two of the eight stage
Output
B registers for writing by the
stage B pipeline.
Normal
Munged
Code
Addresses
Addresses
3′h0
0, 1
0, 1
3′h1
2, 3
4, 5
3′h2
4, 5
2, 3
3′h3
6, 7
7, 6
7:6
Stage B
R/W
2′h0
Selects two of the four stage A
Input
registers for input into the
stage B pipeline.
Code
Addresses
2′h0
0, 1
2′h1
2, 3
2′h2
0, 2
2′h3
1, 3
5:4
Stage B
R/W
2′h0
Opcode for stage B
Opcode
adder/subtractor
2′h0 = NOP
2′h1 = Add operand 0 to 1 and
subtract operand 1 from 0
2′h2 = Add operand 0 to 1 and
subtract operand 0 from 1
3′h3 = Same as 2′h1 but the
(0, j) multiplier is also
applied to operand 1 before
add/subtract.
3:2
Stage A
R/W
2′h0
Selects two of the four stage A
Output
registers for writing by the
stage A pipeline.
Code
Addresses
2′h0
0, 1
2′h1
2, 3
2′h2
0, 2
2′h3
1, 3
1:0
Stage A
R/W
2′h0
Opcode for stage A
Opcode
adder/subtractor
2′h0 = NOP
2′h1 = Add operand 0 to 1 and
subtract operand 1 from 0
2′h2 = Add operand 0 to 1 and
subtract operand 0 from 1
3′h3 = Same as 2′h1 but the π/4
multiplier is also applied to
operand 1 after subtraction.
The register shown in Table 5 define a set of eight datapath microwords that can be used by the sequencer. Each microword defines the multiplexing and other controls needed by the datapath logic for one clock. These microwords are decoded into the raw controls and stored in registers before being used by butterfly 900 to prevent the decoding from being in the critical paths. Each sequencer stage, such as butterfly, fold, and the like, can use up to four microwords in one embodiment.
Table 7, below illustrates frequency map registers:
TABLE 7
Bit
Reset/
(s)
Name
R/W
power-on
Description
23:12
End
R/W
12′h0
Ending frequency bin for a
FFT/IFFT passband
11:0
Start
R/W
12′h0
Starting frequency bin for
a FFT/IFFT passband
The frequency map registers define the passbands for the FFT and IFFT. The first four registers (0xFFF808-0xFFF80B) are used for the FFT and the last four are used for the IFFT. The available frequency map registers are divided evenly between the channels. For a single channel configuration there are four passbands available in each direction. For two channels there are two passbands per direction per channel and for four channels there is only one passband per direction per channel.
The frequency map is used during addressing calculations for input/output frequency domain data transfers and scaling. To save processing cycles the frequency domain transfers only include the frequency bins that are in the passbands. These registers are used to map those samples into the correct place in state memory. They are also used to select the correct scaling values since the scale factors are packed in memory.
TABLE 8
Sequencer Microword Registers
Reset/
Bit
power-
(s)
Name
R/W
on
Description
23
Multiplier
R/W
1′h0
Determines the source for the
Source
datapath stage C multipliers
during scaling operations: 0 =
scaling memory, 1 = Scaling
registers
22
Fold
R/W
1′h0
Setup the datapath pipeline
for Fold processing.
21:20
Input
R/W
2′h0
Number format at the input of
Format
the datapath pipeline (from
memory or point-to-point).
2′h0 = Force zeros as input
2′h1 = Fixed - 16 bit signed
2's complement
2′h2 = FP2 - Signed floating
point, 2 bit exponent, 14 bit
mantissa:
<real exp, real mant><imag
exp, imag mant>
2′h3 = FP4 - Signed floating
point, 4 bit shared exponent,
14 bit mantissa:
<exp[3:2], real
mant><exp[1:0], imag mant>
19:18
Output
R/W
2′h0
Number format at the output of
Format
the datapath pipeline (from
memory or P2P).
2′h0 = Force zeros as output
2′h1 = Fixed - 16 bit signed
2's complement
2′h2 = FP2 - Signed floating
point, 2 bit exponent, 14 bit
mantissa:
<real exp, real mant><imag
exp, imag mant>
2′h3 = FP4 - Signed floating
point, 4 bit shared exponent,
14 bit mantissa:
<exp[3:2], real
mant><exp[1:0], imag mant>
17
Data
R/W
1′h0
Input source for the data
source
pipeline:
0 = Memory, 1 = P2P
16
Data
R/W
1′h0
Output destination for the
destination
data pipeline:
0 = Memory, 1 = P2P
15:12
Pipeline
R/W
4′h0
Number of clock delays from
delay
the input of the pipeline to
the output. This value can be
used to adjust the pipeline
timing for different
configurations.
11:9
DP Uword 3
R/W
3′h0
Datapath microword for cycle 3 -
Selects from one of the 8
microcode registers.
8:6
DP Uword 2
R/W
3′h0
Datapath microword for cycle 2 -
Selects from one of the 8
microcode registers.
5:3
DP Uword 1
R/W
3′h0
Datapath microword for cycle 1 -
Selects from one of the 8
microcode registers.
2:0
DP Uword 0
R/W
3′h0
Datapath microword for cycle 0 -
Selects from one of the 8
microcode registers.
TABLE 9
IFFT OUTPUT GAINS - 4 REGISTERS
IFFT Output Gain Registers
Bit
Reset/
(s)
Name
R/W
power-on
Description
23:12
Mantissa
R/W
12′h0
Unsigned scale factor
mantissa
11:8
Exp
R/W
4′h0
Scale factor exponent
7:0
Reserved
R/W
8′h0
Reserved
There is one gain registers provided per channel. The value is multiplied by all time domain samples of an IFFT output as they are transferred to the TX FIFO.
TABLE 10
ADDRESS GENERATION MICROCODE - 12 REGISTERS
Data Transfer Control Register
Bit
Reset/
(s)
Name
R/W
power-on
Description
23:19
Reserved
R/W
5′h0
Reserved
18
Digit
R/W
1′h0
Apply digit reversal to all
Reverse
address calculations. For
radix-4 the digits are 2
bits and for radix-8 they
are 3 bits.
17:16
Multiplier
R/W
2′h0
Addressing mode for the
Mode
datapath multipliers:
2′h0 = NOP, multiply by 1
2′h1 = Twiddle factor
addresses for butterflies
2′h2 = Scale factor
addresses
3′h3 = Twiddle factor
addresses for fold stages
15:12
AGU Mode
R/W
4′h0
Address generation unit
mode - Determines the type
of memory addresses that
are generated by the AGU.
The AGU generates two read
and two write addresses for
each clock.
4′h0 = Butterfly stage 0
4′h1 = Butterfly stage 1
4′h2 = Butterfly stage 2
4′h3 = Butterfly stage 3
4′h4 = Butterfly stage 4
4′h5 = Butterfly stage 5
4′h6 = Butterfly stage 6
4′h7 = Butterfly stage 7
4′h8 = Increment
4′h9 = Fold - Start at (1,
FFT - SIZE − 1) and
increment by (1, −1)
4′ha = Frequency Map -
Increment through addresses
using the start and end
values of the frequency
map. When an end value is
reached, jump to the next
map.
4′hb = Modulo - Start at
the starting address in
the modulo register and
wrap to zero when the end
address is reached.
4′hc = Fill - Increment
through FFT - SIZE/4
addresses and apply each
address to all four state
RAM banks.
11:0
Clock
R/W
12′h0
Number of cycles to run the
count
sequencer and AGU
microwords.
TABLE 11
IFFT OUTPUT MODULO - 4 REGISTERS
Modulo Registers
Bit
Reset/
(s)
Name
R/W
power-on
Description
23:12
End
R/W
12′h0
Modulo address for the IFFT
output transfer. The memory
address wraps to 0 after
this limit is reached.
11:0
Start
R/W
12′h0
Starting memory address for
the IFFT output transfer
The IFFT modulo registers are provided to facilitate cyclic extension insertion. The output transfer to the TX FIFO can be setup to repeat both the beginning and end of the symbol. For example, if the start address is set to FFT_SIZE−128, the end address to FFT_SIZE, and the clock count is set to FFT_SIZE+256 then the output transfer will be <last 128 samples><full symbol><first 128 samples>. That will allow the TX FIFO to build the cyclic extension without needing random access to the FIFO memory.
Referring back to Table 8, an embodiment is directed to method for efficiently formatting the input and output data for floating point values. More particularly, for purposes of comparison, the following table represents an exemplary thirty-two (32) bits of computer memory for storing a complex number according to the prior art. It should be noted that there are many ways to implement such computer memory such as, but not limited to, RAM, latch memory and registers.
TABLE 12
Reset/
power-
Bit(s)
Name
R/W
on
Description
31
Sign
R/W
1′h0
Indicates whether the real
component of the
represented imaginary
number is positive or
negative
30:20
Significand
R/W
11′h0
Indicates an explicit or
implicit leading bit to the
left of the real component
of the represented number's
implied binary point and a
fraction field to the
right of the implied binary
point
19:16
Exponent
R/W
4′h0
Indicates the power to
which the base 2 number
must be raised to generate
the real component of the
represented number
15
Sign
R/W
1′h0
Indicates whether the
imaginary component of the
represented imaginary
number is positive or
negative
14:4
Significand
R/W
11′h0
Indicates an explicit or
implicit leading bit to the
left of the imaginary
component of the
represented number's
implied binary point and a
fraction field to the
right of the implied binary
point
3:0
Exponent
R/W
4′h0
Indicates the power to
which the base 2 number
must be raised to generate
the imaginary component of
the represented number
The table above includes bits representing the sign (31), i.e. positive or negative, and the significand (30:20) of the mantissa of the real component of the represented complex number. The exponent (19:16) of the real component of the represented complex number is also included. It should be noted that the exponent (19:16) does not include a bit for the sign, although in another example it may.
The table above includes bits representing the sign (15), i.e. positive or negative, and the significand (14:4) of the mantissa of the imaginary component of the represented complex number. The exponent (3:0) of the imaginary component of the represented complex number is also included. As with the real component, it should be noted that the exponent (3:0) does not include a bit for the sign, although in another example it may.
The table above represents the prior art in that the real and imaginary components of the represented complex number each have separate and distinct bits corresponding to their respective exponents.
The following table 12 represents an exemplary thirty-two (32) bits of memory for storing a complex number according to the claimed subject matter.
TABLE 13
Reset/
power-
Bit(s)
Name
R/W
on
Description
31
Sign
R/W
1′h0
Indicates whether the real
component of the imaginary
number is positive or
negative
30:18
Significand
R/W
13′h0
Indicates an explicit or
implicit leading bit to the
left of the real component
of the represented number's
implied binary point and a
fraction field to the
right of the implied binary
point
17:14
Exponent
R/W
4′h0
Indicates one component of
the power to which the base
2 number must be raised to
generate both the real and
imaginary components of the
represented number
13
Sign
R/W
1′h0
Indicates whether the
imaginary component of the
imaginary number is
positive or negative
12:0
Significand
R/W
13′h0
Indicates an explicit or
implicit leading bit to the
left of the imaginary
component of the
represented number's
implied binary point and a
fraction field to the
right of the implied binary
point
Like table 12 above that illustrates the prior art, the table directly above includes bits for the sign (31) and significand (30:18) of the mantissa of the real component of the represented complex number and sign (13) and significand (12:0) of the mantissa of the imaginary component of the represented complex number. Unlike table 12, table 13 includes only one set of bits (17:14) for storing an exponent. The bits (17:14) represent the exponent of both the real and imaginary components of the represented complex number. It should be noted that as a result of sharing an exponent, an additional two (2) bits are able to be allocated for the storage of the significands of the real and imaginary components. It should also be noted that, although the exponent described above does not include a bit for the sign, i.e. positive or negative, in another embodiment it could.
A process 1300 , described below in conjunction with FIG. 13 , illustrates one exemplary method for storing a complex number in such a 32-bit memory location.
The following table 14 represents an alternative embodiment of an exemplary thirty-two (32) bits of memory for storing a complex number according to the claimed subject matter.
TABLE 14
Reset/
power-
Bit(s)
Name
R/W
on
Description
31
Sign
R/W
1′h0
Indicates whether the real
component of the
represented imaginary
number is positive or
negative
30:19
Significand
R/W
12′h0
Indicates an explicit or
implicit leading bit to the
left of the real component
of the represented number's
implied binary point and a
fraction field to the
right of the implied binary
point
18:17
Exponent
R/W
2′h0
Indicates a component of
the power to which the base
2 number must be raised to
generate the real component
of the represented number
16
Sign
R/W
1′h0
Indicates whether the
imaginary component of the
represented imaginary
number is positive or
negative
15:4
Significand
R/W
12′h0
Indicates an explicit or
implicit leading bit to the
left of the imaginary
component of the
represented number's
implied binary point and a
fraction field to the
right of the implied binary
point
3:2
Exponent
R/W
2′h0
Indicates a component of
the power to which the base
2 number must be raised to
generate the imaginary
component of the
represented number
1:0
Multiplier
R/W
2′h0
Indicates a second
component of the power to
which the base 2 number
must be raised to generate
both the real and imaginary
components of the
represented number
Like table 12 above that illustrates the prior art with respect to the claimed subject matter, table 14 includes bits for the sign (31) and significand (30:19) of the mantissa and the corresponding exponent (18:17) of the real component of the represented complex number and sign (16) and significand (15:4) of the mantissa and the corresponding exponent (3:2) of the imaginary component of the represented complex number.
Unlike table 12 that illustrates the memory location corresponding to the prior art, the table 14 also includes a set of bits (1:0) for storing an exponent “multiplier”. The exponent multiplier is combined with both the real exponent bits (18:17) and the imaginary exponent bits (3:2) to arrive at the correct exponents for each component.
It should be noted that as a result of sharing an exponent multiplier, an additional one (1) bit is able to be allocated for the storage of the significands of the real and imaginary components. In effect, the multiplier enables the real and imaginary components to have a larger difference in magnitude before any rounding must occur, as described below in conjunction with FIG. 13 . It should also be noted that, although neither of the non-shared exponent bits described above do not include a bit for the sign, i.e. positive or negative, in another embodiment they could.
Referring now to FIG. 13 , a flow diagram illustrates process 1300 for storing a complex number in a manner consistent with the claimed subject matter. Process 1300 starts in a “Begin Store Complex Number” block 1302 and control proceeds immediately to a “Normalize Components” block 1304 . During block 1304 , process 1300 puts both the real and imaginary components of a subject complex number into a normalized form, i.e., each mantissa is adjusted to fall within predefined boundaries and the corresponding exponents are adjusted accordingly so that the each of the original component values are accurately reflected in the corresponding mantissa/exponent pair.
Process 1300 then proceeds to a “Compare Exponents” block 1306 during which the normalized exponents of the real and imaginary components are compared. In decision block 1308 , if the real exponent is larger than the imaginary exponent, then control proceeds to a “Right Shift Imaginary Mantissa” block 1310 during which the significand of the mantissa of the imaginary component of the represented complex number is right shifted by a value equal to the difference of the exponents. Process 1300 then proceeds to a “Truncate Imaginary Mantissa” block 1312 during which the right shifted significand is either truncated or rounded, depending upon the particular implementation, to a size that equals the size of the bits allocated for its storage.
Note that rounding can introduce a problem case where adding a 1 to the least significant bit would cause an increase in the exponent after re-normalization. However, since we only round the right shifted mantissa, this cannot occur. During Normalize Components block 1304 , there could be rounding as well, especially if the pipeline width is wider than the final memory width.
If, in block 1308 , the real exponent is less than or equal the imaginary exponent, then control proceeds to a “Right Shift Real Mantissa” block 1314 during which the significand of the mantissa of the real component of the represented complex number is right shifted by a value equal to the difference of the exponents. It should be noted that if the difference is equal to ‘0’, then significand of the mantissa of the real component of, the represented complex number does not need to be right shifted. Process 1300 then proceeds to a “Truncate Real Mantissa” block 1316 during which the right shifted significand is either truncated or rounded, depending upon the particular implementation, to a size that equals the size of the bits allocated for its storage.
Control proceeds from both blocks 1312 and 1316 to a “Store Complex Number” block 1318 during which the real and imaginary mantissa are stored in the appropriate place in memory and the exponent of the non-shifted component is stored in the shared exponent memory location. Control then proceeds to an “End Store Complex Number” block 1320 in which process 1300 is complete.
Process 1300 describes a method of storing a complex number when the allocated memory includes only a single shared set of bits for storing the exponents of the real and imaginary components of the represented complex number. As described above, another embodiment of the claimed subject matter includes a first and second set of bits for the exponents of the real and imaginary components and a third set of bits that represent a multiplier exponent. In this embodiment, Compare Exponents block 1306 determines whether or not the exponents of the real and imaginary components are close enough in value such that the multiplier can account for the difference. If not, a right shift is executed on the appropriate mantissa such that the multiplier is able to account for the difference. Then, in block 1318 , the exponents of the real and imaginary components are each factored into two components, one representing the shared multiplier and a second and third corresponding to values such that the corresponding exponent can be recalculated. The three values are then stored in the appropriate memory locations.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing embodiments of the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
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A method for storage for complex numbers that employs a shared exponent field is disclosed. Rather than each floating point component of an complex number having its own distinct signed mantissa and exponent fields, each component includes a distinct signed mantissa field and shares an exponent field, thereby increasing the possible size of each distinct signed mantissa field by as much as one half the number of bits formerly employed to store a single distinct exponent field.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a U.S. National phase of, and claims priority based on PCT/JP2008/053779, filed 3 Mar. 2008, which, in turn, claims priority from Japanese patent applications 2007-100800, filed 6 Apr. 2007. The entire disclosure of each of the referenced priority documents is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to a pneumatic tire, and more specifically, to a pneumatic tire designed so that a hook and loop fastener for attaching such an accessory as an acoustic material is fitted to the tire internal face of a pneumatic tire furnished with an inner liner layer consisting of a thermoplastic elastomer composition of a blend of thermoplastic resin and elastomer, or a thermoplastic resin.
BACKGROUND ART
In a tubeless pneumatic tire, an inner liner layer consisting of butyl-based rubber having an excellent air-impermeable property is integrally lined to the tire internal face thereof as an air-permeation preventing layer. However, since the butyl-based rubber is heavy, Patent Document 1 proposes to use a thermoplastic resin having a small specific gravity or a thermoplastic elastomer composition containing the thermoplastic resin as a main component, in place of the butyl-based rubber.
Meanwhile, recently, for the purpose of improving the performance of a pneumatic tire, in a hollow portion, an acoustic material for reducing resonance that generates at the hollow portion is attached, or a sensor for detecting air pressure or temperature is attached. For example, as an attachment method of the acoustic material, there are proposed an attachment method by fixing a hook and loop fastener to the surface of an inner liner layer through the use of an adhesive, and an attachment method by providing an anchor element on the surface of the inner liner side of the hook and loop fastener to be fixed to the tire internal face (for example, see Patent Document 2)
However, for above-described tires fitted with an inner liner layer consisting of a thermoplastic elastomer composition containing thermoplastic resin as the main component, or a thermoplastic resin, there occurs a problem that, when fixing a hook and loop fastener to the inner liner layer using an adhesive or the like, the hook and loop fastener can not follow the elongation of the inner liner layer caused by expanding the diameter at the time of the vulcanization molding of the tire. In addition, when providing a hook and loop fastener with an anchor element to be fixed penetratingly to the tire internal surface, there was such problem that air permeation-preventing properties lower because it damages the inner liner layer.
Patent Document 1: Japanese patent application Kokai publication No. 8-258506 Patent Document 2: Japanese patent application Kokai publication No. 2006-44503
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a pneumatic tire designed so that when a hook and loop fastener is fitted to the tire internal face of a pneumatic tire furnished with an inner liner layer consisting of a thermoplastic elastomer composition of a blend of thermoplastic resin and elastomer, or a thermoplastic resin, the hook and loop fastener can easily follow the elongation of the inner liner layer and is free from damaging of the inner liner layer.
The pneumatic tire of the present invention for achieving the above purpose is one furnished with an inner liner layer consisting of a thermoplastic elastomer composition composed of thermoplastic resin and elastomer, or a thermoplastic resin, on its internal face and is characterized in that integral forming of a multiplicity of interlocking elements protruding on the hollow side of the tire is effected on the surface of said inner liner layer.
The interlocking element preferably has a height of from 0.5 to 5.0 mm.
It is favorable to arrange the interlocking elements in a region corresponding to the tread portion of the pneumatic tire and to load an acoustic material consisting of a porous material to these interlocking elements.
It is favorable to provide a multiplicity of anchor elements buried in the tire internal face in a protruding condition on the surface of the inner liner layer opposite to the interlocking elements.
The anchor elements are preferably integrally molded with the inner liner layer.
When the anchor elements are composed of a supporting portion connected to the inner liner layer and an widening portion at the front edge of the supporting portion, it is favorable to allow the width Wa of the supporting portion and the greatest width Wb of the widening portion to satisfy the formulae (1) and (2) below, while denoting the height of the anchor elements by H:
1.6Wa≦H≦3.8Wa (1)
2.0Wa≦Wb≦3.5Wa (2)
Further, when arranging the anchor elements intermittently, the thickness T of the anchor element preferably satisfies the formula (3) below relative to the width Wa:
0.7Wa≦T≦1.3Wa (3)
Furthermore, the height H of the anchor elements from the inner liner layer main body is favorably from 0.1 to 0.5 mm.
According to the present invention, in a pneumatic tire in which the inner liner layer is formed from a thermoplastic elastomer composition, or a thermoplastic resin, the interlocking elements of a hook and loop fastener are integrally molded with the inner liner layer, and therefore, it is possible to allow the interlocking elements to follow integrally to the elongation of the inner liner layer at the time of vulcanization molding and to leave the inner liner layer to be free from damage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a half cross-sectional view in the tire meridional direction which shows one example of the embodiment of the pneumatic tire of the present invention.
FIG. 2 is a perspective explanatory view which shows one example of the embodiment of the inner liner layer for use in the present invention.
FIG. 3 is a perspective explanatory view which shows another example of the embodiment of the inner liner layer for use in the present invention.
FIG. 4 is an explanatory view that exemplifies the cross-section of the cut inner liner layer and carcass layer of the pneumatic tire of the present invention which uses the inner liner layer in FIG. 3 .
FIG. 5A to 5C are perspective explanatory views which show examples of the embodiment of the anchor element provided in a protruding condition on the inner liner layer for use in the present invention.
FIG. 6 is a perspective explanatory view which shows one example of molding process of the inner liner layer for use in the present invention.
4 carcass layer 4 a carcass code 4 b coating rubber 7 inner liner layer 8 interlocking element 9 anchor element 9 a supporting portion 9 b widening portion 10 acoustic material
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a half cross-sectional view in the tire meridional direction which shows one example of the embodiment of the pneumatic tire of the present invention.
In FIG. 1 , 1 indicates a tread portion, 2 indicates a side wall portion, 3 indicates a bead portion, and 4 indicates a carcass layer. The carcass layer 4 is mounted between a pair of right and left bead cores 5 buried in the bead portion 3 , and the both end portions thereof respectively are designed so as to be turned from the inside of the tire to the outside around bead core 5 . Inside the tread portion 1 , a pair of upper and lower belt layers 6 is arranged all the way around the tire outside the carcass layer 4 . Further, on the innermost side of the tire, an inner liner layer 7 formed from a thermoplastic elastomer composition consisting of thermoplastic resin and elastomer, or a thermoplastic resin, is lined as the air permeation-preventing layer.
A multiplicity of interlocking elements 8 are integrally molded on the surface of the tire hollow side of the inner liner layer 7 , and it is designed so that these interlocking elements 8 function as a hook and loop fastener and make it possible to fix removably such an accessory as an acoustic material 10 consisting of, for example, such a porous material as polyurethane foam. To the surface on the acoustic material side, a multiplicity of loops 11 removable relative to the interlocking elements 8 are provided as a hook and loop fastener on the other side.
The acoustic material 10 is composed of a porous material having sound-absorbing function, and when it is formed from a fiber structure consisting of a multiplicity of fibers, it can be joined directly because the structure itself has a multiplicity of loops.
On the surface of the inner liner layer 7 , the interlocking elements 8 may be arranged intermittently in lines in vertical and transverse directions as shown in FIG. 2 , or at random. When they are orderly arranged like the former, the column direction may be in the tire circumferential direction, or it may be in a tilted direction relative to the tire circumferential direction.
No particular limitation is imposed on the shape of the interlocking elements 8 only if the element exerts the function of interlocking with the hook and loop fastener and the like on the other side. The element may have a tabular shape of a T-letter or arrow by forming an widening portion at the front edge or distal end of a supporting portion erected on the surface of the inner liner layer, as exemplified in FIG. 2 , and in addition, a fungus shape formed by rotating the supporting portion around the central axis thereof. In any case, the shape is preferably one capable of being integrally molded with the inner liner layer.
Since the interlocking elements 8 constituting the hook and loop fastener are integrally molded with the inner liner layer as describe above, the inner liner layer is not damaged and the air permeation-preventing property is not worsened, as in the case of sticking or joining another independent hook and loop fastener to the inner liner layer surface. Further, since the interlocking elements are integrally formed with the inner liner layer, they follow the elongation of the inner liner layer in the diameter-expanding process at the vulcanization molding and no trouble such as falling off occurs.
No particular limitation is imposed on the position for arranging the interlocking elements 8 on the tire internal face. The elements may be arranged on the whole surface of the internal face, or a part thereof. When attaching the acoustic material 10 in such a manner as exemplified in the drawing, they are preferably arranged in the region corresponding to the tread portion.
The arrangement density of the interlocking elements on the inner liner layer 7 is preferably from 12 to 90 pieces/cm 2 . An arrangement density of the interlocking elements 8 less than 12 pieces/cm 2 can not give sufficient attaching strength of such an attaching member as the acoustic material 10 , and the density more than 90 pieces/cm 2 may occasionally lead to too narrowed distance between widening portions of the interlocking elements 8 with each other to thereby result in such trouble in interlocking that loops of the hook and loop fastener on another side are hardly hooked.
No particular limitation is imposed on the protruding height of the interlocking elements 8 from the surface of the inner liner layer 7 , but the height may preferably be from 0.5 to 5.0 mm. By setting the height of the interlocking elements 8 within the range, it is possible to make the attachment strength of such an accessory as the acoustic material sufficient.
On the other hand, a method for sticking the inner liner layer to the tire internal face may also be performed by sticking it to the surface of the carcass layer 4 directly or through the use of an adhesive, but preferably, as shown in FIG. 3 , it is favorable to provide a multiplicity of anchor elements 9 in a protruding condition to the surface opposite to the surface on which the interlocking elements 8 are formed, and to bury these multiplicity of anchor elements 9 in a coating rubber 4 b of the carcass layer 4 covering and extending between a plurality of carcass cords 4 a , as shown in FIG. 4 . The inner liner layer composed of a thermoplastic elastomer composition or a thermoplastic resin has poor adhesion to rubber, but by employing such constitution, it is possible to improve the joint strength between the inner liner layer and the tire internal surface. Further, an adhesive rubber layer may be laid between the inner liner layer 7 and the carcass layer 4 .
The arrangement of the anchor elements 9 on the surface of the inner liner layer 7 may be intermittent in lines in vertical and transverse directions as is the case for the interlocking elements 8 , or may be random. When they are orderly arranged like the former, the column direction may be in the tire circumferential direction, or it may be in a tilted direction relative to the tire circumferential direction.
No particular limitation is imposed on the shape of the anchor elements 9 , if the element has an anchor function. As is the case with the interlocking elements 8 , the shape of the anchor elements 9 having a widening portion formed at the front edge or distal end of the supporting portion erecting on the surface of the inner liner layer, and, in addition, the one formed by processing the side surface of the supporting portion into a saw-tooth configuration may be employed. But, preferably, one composed of a supporting portion and a widening portion at the front edge is favorable. The anchor elements 9 are not limited to ones formed in a shape of independent spots as the example shown in the drawing, but may be ones continuously formed in a rail shape (projecting strip).
FIG. 5A to 5C exemplify preferable shapes of the anchor elements 9 , which are composed of the supporting portion 9 a and the widening portion 9 b at the front edge. FIG. 5A and FIG. 5B show the cross-sectional shape of a T letter shape, and FIG. 5C shows the cross-sectional shape of an arrow shape. In all cases, after entering an unvulcanized rubber layer and then the vulcanization processing, the widening portion 9 b becomes hardly extractable to exert an anchor effect. Although examples as shown in the drawing have a flat plate shape, a shape of a fungus formed by rotating the supporting portion around the central axis may also be employed.
In the anchor elements 9 having the shapes of FIG. 5A to FIG. 5C , when denoting the height from the inner liner layer 7 by H, the width Wa of the supporting portion 9 a , and the greatest width Wb of the widening portion 9 b , preferably have the relation of the formulae (1) and (2) below:
1.6Wa≦H≦3.8Wa (1)
2.0Wa≦Wb≦3.5Wa (2)
Further, when the anchor elements 9 are tabular shape and are in a spot, the thickness T of the supporting portion 9 a and the width Wa preferably satisfies the relation of the formula (3) below:
0.7Wa≦T≦1.3Wa (3)
When the width Wa and the thickness T of the supporting portion 9 a are too small, the rigidity of the supporting portion 9 a lowers and it is likely to break easily, and when they are too great, it becomes difficult to enter unvulcanized rubber. Further, when the greatest width Wb of the widening portion 9 b is too small relative to the width Wa of the supporting portion 9 a , the joint strength-enhancing effect cannot be sufficiently obtained, and when it is too great, it becomes difficult to enter unvulcanized rubber.
The height H of the anchor element 9 may preferably be from 0.1 to 0.5 mm. When the height H is less than 0.1 mm, the joint strength with the carcass layer can not be sufficiently obtained, and when it is above 0.5 mm, it may occasionally touch the carcass code to thereby lower the durability.
The anchor elements 9 on the inner liner layer 7 have arrangement densities of preferably 2 to 60 pieces/cm 2 . When the arrangement density of the anchor elements is too small, the joint strength cannot be sufficiently obtained, and even if it is too great, the joint strength is also lowered, unpreferably.
The anchor elements 9 are preferably provided in a protruding condition on the whole surface of the inner liner layer 7 , but they do not always have to be provided on the whole surface. For example, anchor elements are provided in regions corresponding to the tread portion and/or bead portion of a pneumatic tire, and are not provided in other regions, or an adhesive rubber layer may be interposed. Further, in a shoulder region or the like which is susceptible to great shear deformation, the anchor element and the adhesive rubber layer may be used at the same time.
In the present invention, although no particular limitation is imposed on a method for integrally molding the inner liner layer and the interlocking element, but for example, as shown in FIG. 6 , by extruding a thermoplastic elastomer composition consisting of thermoplastic resin and elastomer, or a thermoplastic resin, from a die 12 of an extruder so that the inner liner layer 7 and the projecting strips of interlocking elements stand parallel, forming slits on the projecting strips of interlocking elements in a crossing direction intermittently at small pitches, and then performing stretching processing, it is possible to form into a shape in which a multiplicity of independent interlocking elements are arranged isolatedly and intermittently in the stretching direction.
As described above, by integrally molding the interlocking elements with the inner liner layer, it is possible to improve productivity and improve air permeation-preventing performance. In addition, the inner liner layer main body may be extruded in a cylindrical shape, subjected to inflation molding to be formed into a cylindrical film.
No particular limitation is imposed on a method for providing the anchor elements in a protruding condition relative to the inner liner layer. The anchor elements molded separately from the inner liner layer may be adhered or implanted to the layer, or the interlocking elements and the anchor elements may be integrally molded when molding the inner liner layer. Particularly, integral molding of the anchor elements with the interlocking elements and inner liner layer improves the productivity and improves the air permeation-preventing performance, preferably.
Regarding the method for integrally molding the anchor elements with the interlocking elements and inner liner layer, it may be molded in the same manner as the method for integrally molding the interlocking elements and inner liner layer. For example, it is favorable to perform the molding by using a die for forming the interlocking element on one surface of the inner liner layer and forming the anchor element on the opposite surface. Meanwhile, upon molding the anchor element, by performing the extrusion in a projecting shape from a die so as to line parallel, and directly stretching them without forming slits, the anchor element can be formed in a continuous projecting strip shape.
Examples of thermoplastic resin for forming the inner liner layer include polyamide-based resins [for example, nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), nylon 6/66 copolymer (N6/66), nylon 6/66/610 copolymer (N6/66/610), nylon MXD6, nylon 6T, nylon 6/6T copolymer, nylon 66/PP copolymer, and nylon 66/PPS copolymer], polyester-based resins [for example, aromatic polyesters such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene isophthalate (PEI), polybutylene terephthalate/tetramethylene glycol copolymer, PET/PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystalline polyester, and polyoxyalkylene diimidic acid/polybutylene terephthalate copolymer], polynitrile-based resins [for example, polyacrylonitrile (PAN), polymethacrylonitrile, acrylonitrile/styrene copolymer (AS), methacrylonitrile/styrene copolymer, and methacrylonitrile/styere/butadiene copolymer], poly(meth)acrylate-based resins [for example, polymethyl methacrylate (PMMA), polyethyl methacrylate, ethylene/ethyl acrylate copolymer (EEA), ethylene/acrylic acid copolymer (EAA), and ethylene methyl acrylate resin (EMA)], polyvinyl-based resins [for example, vinyl acetate (EVA), polyvinyl alcohol (PVA), vinyl alcohol/ethylene copolymer (EVOH), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), vinyl chloride/vinylidene chloride copolymer, and vinylidene chloride/methyl acrylate copolymer], cellulose-based resins [for example, cellulose acetate, and cellulose acetate butyrate], fluororesins [for example, polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), and tetrafluoroethylene/ethylene copolymer (ETFE)], and imide-based resins [for example, aromatic polyimide (PI)].
The thermoplastic elastomer composition for forming the inner liner layer is consisting of the above-described resin and an elastomer. The composition ratio of the thermoplastic resin and the elastomer may be suitably determined based on the balance of the thickness and flexibility of the inner liner layer, and is preferably within the range of 10/90 to 90/10 (weight ratio), and more preferably 20/80 to 85/15.
Examples of elastomers constituting such a thermoplastic elastomer composition include diene-based rubbers and hydrogenated products thereof [for example, NR, IR, epoxidized natural rubber, SBR, BR (high-cis BR and low-cis BR), NBR, hydrogenated NBR, and hydrogenated SBR], olefin-based rubbers [for example, ethylene propylene rubber (EPDM, EPM), and maleic acid-modified ethylene propylene rubber (M-EPM)], butyl rubber (IIR), isobutylene/aromatic vinyl or diene-based monomer copolymer, acrylic rubber (ACM), ionomer, halogen-containing rubbers [for example, Br-IIR, Cl-IIR, brominated product of isobutylene-paramethyl styrene copolymer (Br-IPMS), chloroprene rubber (CR), hydrin rubber (CHC, CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), and maleic acid-modified chlorinated polyethylene (M-CM)], silicone rubbers [for example, methyl-vinyl silicone rubber, dimethyl silicone rubber, and methyl-phenyl-vinyl silicone rubber], sulfur-containing rubbers [for example, polysulfide rubber], fluororubbers [for example, vinylidene fluoride-based rubber, fluorine-containing vinyl ether-based rubber, tetrafluoroethylene-propylene-based rubber, fluorine-containing silicon-based rubber, and fluorine-containing phosphazene-based rubber], and thermoplastic elastomers [for example, styrene-based elastomer, olefin-based elastomer, polyester-based elastomer, urethane-based elastomer, and polyamide-based elastomer].
The base material of the inner liner layer, interlocking elements, and the anchor elements may be composed of the same material, or different materials, and when different materials are used, two-color molding is preferable.
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A pneumatic tire designed so that when a hook and loop fastener is fitted to the tire internal face of a pneumatic tire furnished with an inner liner layer consisting of a thermoplastic elastomer composition of a blend of thermoplastic resin and elastomer, or a thermoplastic resin, the hook and loop fastener can easily follow the elongation of the inner liner layer and is free from damaging of the inner liner layer. There is disclosed a pneumatic tire furnished on its internal face with an inner liner layer ( 7 ) consisting of a thermoplastic elastomer composition composed of thermoplastic resin and elastomer, or a thermoplastic resin, characterized in that integral forming of a multiplicity of interlocking elements ( 8 ) protruding on the hollow side of the tire is effected on the surface of the inner layer ( 7 ).
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FIELD OF THE INVENTION
This invention relates generally to a method of treating intraocular tissues and of removing intraocular membranes by directing laser radiation into the eye. In particular, it relates to a method of performing surgical laser treatments of the eye without causing substantial damage to the fundus.
BACKGROUND OF THE INVENTION
The light absorption and light transmission characteristics of the tissues and fluids of the eye have been the subjects of study for a number of years. By means of various spectroscopic measuring devices, the absorption and transmission by the parts of the eye of light of a wide range of wavelengths have been determined with accuracy sufficient to permit reproduction of the results.
In order to produce light of a range of wavelengths, from the ultraviolet range through the infrared range, mercury vapor, xenon arc, halogen and laser light sources, among others, have been employed. These light sources were then utilized to determine the specific wavelength ranges in which the individual eye parts absorbed or transmitted light.
Among the findings of these studies was the finding that the transmission of ultraviolet light by the frontal portions of the eyes decreases with age, while the transmission of infrared light by those same portions of the eyes was essentially independent of age.
The use of laser light in ophthalmic treatments is a relatively recent development growing out of such studies, one which began in about 1965 with the use of the ruby laser. The use of the argon laser in ophthalmology began shortly thereafter, followed by the advent of the neodymium-doped yttrium-aluminum garnet laser (commonly known as the Nd:YAG laser).
Both the argon laser and the Nd:YAG have recently been utilized in numerous ophthalmic surgical procedures, among them the treatment of glaucoma and cataracts. With respect to treatment of the former condition, one procedure has involved directing a short, strong laser pulse through the pupil so as to form a hole between the anterior and posterior chambers, thereby equalizing intraocular pressure. In another procedure, a laser pulse aimed at the trabecular meshwork is utilized to open a blocked duct to the canal of Schlemm. Alternatively, the laser pulse is used to make a small mark in the trabecular meshwork, which, in the process of scar formation, pulls the surrounding tissue toward the mark. This tissue stretching causes the small ducts and canals of that region to open into the canal of Schlemm, thus restoring the circulation of fluid within the eye.
Other surgical procedures employing laser light are of great importance. Among them are the opening of the lens capsule and the breaking of membranes in the vitreous. With respect to the latter, it is well-known that capsular opacification is the major complication which occurs after extracapsular extraction of the lens and insertion of a posterior chamber implant. While meticulously clearing and polishing the posterior capsule reduce capsular opacification to some degree, the condition is never fully eliminated. Previous treatment of this secondary membrane condition has been accomplished by capsulotomy with a cytotome or knife, or, when the membranes are thick, by pars planar membranectomy. Both of these procedures require substantial intraocular manipulation and both therefore create the risk of intraocular infection or retinal detachment. Accordingly, the use of a laser as a non-invasive method of managing such secondary membranes is highly desirable. For the same reasons, it is desirable to disrupt other types of membranes, such as those which form behind other intraocular implants, by means of laser treatment.
A danger present in each of the laser surgical procedures discussed above, is that the laser light will penetrate beyond the tissues desired to be treated and will be transmitted to the retina where undesirable photocoagulation damage will occur. This is particularly true in the case of capsulotomies and in the case of the breaking of occluding membranes, whether pupillary or vitreous, wherein the laser beam is directed along the visual axis. In these cases, any damage to the fundus results in permanent vision impairment. Therefore, essentially no risk is tolerable in such procedures.
Thus, an important limitation is placed on the scope of use of ophthalmic laser treatments i.e., the need to avoid any substantial laserinduced damage to the fundus.
BRIEF DESCRIPTION OF THE PRIOR ART
It is well documented in the prior art that, unless precautionary measures are taken, laser surgical treatment of the anterior structures of the eye may result in substantial damage to the fundus. The extent to which such damage occurs is, of course, dependent upon the type of laser utilized, since each type emits a different wavelength and since different portions of the eye possess different light transmission and absorption characteristics.
The particular absorption and transmission characteristics of each distinct ocular structure were extensively studied by Boettner et al. in their paper entitled "Transmission Of The Ocular Media", published at pp. 776-783 of 1 Investigative Ophthamology 6 (December 1962). Boettner et al. found that the eye as a whole transmitted a significant percentage of light in the range from the ultraviolet (wavelengths of 300 nanometers and above) through the near infrared (wavelengths of up to about 2200 nanometers). Each structure of the eye, however, had one or more significant absorption bands corresponding to those of water.
With respect to the individual ocular structures, the findings were as follows: (1) Cornea--good transmittance throughout the studied range, but with sharp absorption bands at 1430 nanometers and at 1950 nanometers. (2) Aqueous humor--good transmittance from about 280 nanometers to about 1400 nanometers, with identifiable absorption bands at 980 nanometers and at 1200 nanometers. The aqueous has less than 1% transmittance from 220 to 260 nanometers, and reaches a level of only approximately 18% transmittance between about 1500 nanometers and about 1900 nanometers. There is virtually no transmittance beyond the absorption band at about 1950 nanometers. (3) Lens--range of transmission is from about 310 nanometers to about 1900 nanometers. Sharp absorption bands exist at about 360 nanometers and at about 1430 nanometers, while other identifiable bands occur at 980 nanometers and at 1200 nanometers. Transmission is quite high in the wavelength range from about 400 nanometers to about 1400 nanometers. (4) Vitreous humor--range of transmission is from about 300 nanometers to about 1450 nanometers, with a sharp absorption band at about 980 nanometers and an identifiable band at about 1200 nanometers. The transmission of the vitreous falls off sharply beginning at about 1100 nanometers.
Vassiliadis, "Photocoagulation Source Technology And Ocular Effects", ch. 2, pp. 5-19 of Ocular Photocoagulation (1975), teaches the desirability of using a laser having an output wavelength which is transmitted well by all the ocular media and is absorbed well by the target structure in those instances when it is the object of the procedure to produce photocoagulation effects in the fundus. This reference further notes that laser light sources generating wavelengths in the infrared region are of no utility for that purpose because of their absorption by water in the ocular media.
Yet where the object is to treat ocular structures anterior to the fundus, photocoagulation of the retina or its associated structures is highly undesirable. L'Esperance, Ocular Photocoagulation, (1975), ch. 14, "Complications", relates the effects of the penetration of an argon laser beam (having wavelengths of 457.9, 488.0 and 514.5 nanometers) to structures posterior to those desired to be treated. In performing argon laser treatments of the cornea, for example, it has been found that an area having an endothilial haze will require increased power to effect the treatment. When, however, the beam is then moved from such an area to another not having such a haze, the penetration of the beam will be such as to render retinal or choroidal rupture possible. This same danger may arise when it is the lens which is being treated, for an area of opacification of the lens will require a similar increase in the power delivered to the affected area in order to successfully complete the treatment. This power increase will similarly increase the likelihood of damage to the fundus in the event of a deflection or movement of the beam. Such dangers are also present when it is desired to effect laser treatment of the vitreous whenever blood cells or other debris is present therein.
Similarly, Stefani et al., "Q-Switched Ruby Laser Induced Damage Of The Adult Rabbit Lens Capsule", Graefes Arch. klin. exp. Ophthal. 206, 49-55 (1978), reported that an observed side-effect or complication arising from inducing rupture of the anterior lens capsule with a ruby laser was a very serious one, i.e., retinochoroidal rupture with localized preretinal hemorrhage.
Parallel findings have been recorded with respect to the use of the Nd:YAG laser (wavelength 1064 nanometers) in treatments of the iris in Roper-Hall et al., eds., Advances In Ophthalmology, Vol. 39 (1979), pp. 68-69. It is noted in this reference that precautionary measures are necessary to prevent retinal, corneal or lenticular damage when treating the iris with various types of lasers. In particular, it is taught that, in order to protect the retina, one must exactly focus the beam upon the treatment area and must insure that there is an oblique incidence of the beam upon the iris. The experimental procedure described, namely, the directing of a series of stepped energy increase Nd:YAG laser pulses at the iris, resulted in heavy chorio-retinal damage even at the lower to middle energy ranges.
Goldman et al., "Ocular Damage Thresholds And Mechanisms For Ultrashort Pulses Of Both Visible And Infrared Laser Radiation In The Rhesus Monkey", Exp. Eye Res. 24, 45-56 (1977), have reported, however, that there is no significant difference between the type of retinal damage produced by different exposure diameters at the Nd:YAG wavelength of 1064 nanometers. This retinal damage has been characterized by Marshall, "Thermal And Mechanical Mechanisms In Laser Damage To The Retina," Investigative Ophthalmology, pp. 97-115 (February 1970), as resulting from both the thermal and mechanical effects of the beam striking the retina. Marshall further observed that absorption of the beam by melanin granules appeared to be responsible for these effects.
Other evidence of the need to prevent the penetration side-effects of laser treatments of ocular structures is documented by Fuller et al., Carbon Dioxide Laser Surgery Of The Eye, pp. 214-225, who noted that a previous study involving CO 2 laser penetration of the sclera resulted in damage to the lens and to the cornea. Nonetheless, Fuller et al. teach the use of the CO 2 laser for treatment of tissues anterior to the anterior chamber, stating that the aqueous is opaque to the CO 2 laser beam and acts as a barrier to further intraocular penetration by the beam.
As reported by a number of investigators, substantial damage to the fundus is likely when laser devices are utilized in an effort to treat the anterior portions of the eye. Laser energy which penetrates the treated structures during the procedure is transmitted to the fundus by the intermediate ocular tissues, thereby causing injury from undesired photocoagulation. This danger is present when any of the three most widely used laser sources, namely the argon laser with its wavelengths in the visible range (i.e., 457.9, 488.0 and 514.5 nanometers), the ruby laser which also emits in the visible range (i.e., at 695.0 nanometers), and the Nd:YAG laser with its wavelength in the near infrared range (i.e., 1064 nanometers), are used for laser surgical treatments, as reported by Van der Zypen, "On The Effects Of Different Laser Energy Sources Upon The Iris Of The Pigmented And The Albino Rabbit", Int. Ophthalmology, 1,1:39-48 (1978). The danger of injury to the fundus is, as previously noted, known to be particularly great when these lasers are utilized for capsulotomies or for disrupting other intraocular membranes.
That severe retinal damage is caused by laser radiation in the infrared wavelength range, i.e., by the Nd:YAG laser emitting at 1064 nanometers, is therefore widely reported, despite the suggestions of some investigators, notably Boettner et al. and Vassiliadis, that such laser energy would not penetrate the eye sufficiently to cause photocoagulation. Accordingly, the dangers inherent in the ophthalmic surgical use of lasers emitting in the near infrared range are well-known.
SUMMARY OF THE INVENTION
In order to reduce and prevent damage to the fundus during laser surgery involving tissues and membranes of the eye anterior to the retina, a new ophthalmic surgical method is provided which comprises treating the desired area by exposing it to laser light having a wavelength such that at least about 80% or more of the laser light penetrating the treatment area is absorbed by the vitreous before it can reach and damage the retina. Thus, the method of the invention permits known laser surgical procedures to be performed with much greater safety to the retina and its associated structures.
The laser light to be utilized in the new method of the invention is in the near infrared range. In particular, we have found that laser light having a wavelength of from about 1100 nanometers to about 1350 nanometers, or having a wavelength of between about 1850 nanometers and about 2050 nanometers, would be suitable for this purpose. In these wavelength ranges the transmission of the cornea is as high as 80%, the transmission of the aqueous humor is as high as 70%, and the transmission of the lens is as high as 70%. The vitreous humor, however, transmits a maximum of from about 5% to about 8% of the laser light at these frequencies.
The preferred wavelength range for the laser light used in the present invention is from about 1100 nanometers to about 1350 nanometers. Laser radiation in this range is particularly useful for performing membrane disruption procedures, although the precise wavelength to be used depends upon the location and nature of the membrane. Laser light having wavelengths of from about 1100 nanometers to about 1200 nanometers is useful for disrupting pupillary membranes and for disrupting membranes or other floating tissue in the vitreous. While use of the laser in this wavelength range reduces the risk of damage to the cornea, there remains some danger of retinal damage, but not such danger as could not be easily avoided by proper aiming techniques. At these wavelengths approximately 70% to 80% of the laser energy is absorbed prior to reaching the retina. Thus, proper aiming may produce the desired treatments with minimal retinal damage.
When laser radiation having a wavelength of about 1300 nanometers (1300-1310 nanometers) is utilized in membrane disruption procedures, however, the retina cannot be damaged even if the laser beam is focused upon it. Most preferably, therefore, the method of the invention is carried out by utilizing an Nd:YAG laser source emitting radiation at a wavelength in the range of from about 1300 nanometers to about 1310 nanometers. A device found particularly useful for this purpose is the mode-locked "P/V YAG" laser, manufactured by Laser Tek OY, a corporation of Finland, which emits radiation in this most preferred wavelength range. Accordingly the method of the present invention permits a minimum amount of the laser radiation to penetrate to the fundus, and the danger of damage to the retina and its associated structures is therefore greatly reduced or even eliminated entirely. Moreover, by eliminating the need to employ numerous and awkward precautionary measures, the method of the invention enables the surgeon to choose the energy and location of the laser impacts so as to most effectively treat the desired area, rather than compromise that effectiveness out of concern for causing other damage.
The laser light utilized in the invention is preferably directed into the eye by means of a mirror (articulating) arm or by means of an optic fiber, or by other well-known means.
It is also preferable that the laser light source be equipped to generate pulsed laser light having a pulse duration of from about 10 to about 50 nanoseconds, each pulse delivering energy in the range of from about 100 milli-Joules to about 150 milli-Joules.
Accordingly, it is an object of the present invention to provide a method of treating anterior portions of the eye by laser radiation having a wavelength which substantially reduces the danger of injuring the fundus with that portion of the laser radiation which may otherwise penetrate the treatment area.
A further object of the invention is to provide a method of laser treatment or membrane disruption which permits the surgeon to effectively treat the desired area without being required to compromise that treatment (e.g., to change the angle of incidence of the laser beam) in order to avoid causing unwanted photocoagulation injury to the fundus.
Other objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description and claims.
DETAILED DESCRIPTION
Set forth in the following discussion are summaries of a number of laboratory and animal studies demonstrating the principles of the present invention.
Preliminary Evaluations
1. An infrared spectrophotometer was used to evaluate the transmission characteristics of the cornea, the aqueous, the lens and the retina. These characteristics were compared with those of normal saline and with those of water. These studies were conducted in an attempt to confirm the findings of Boettner et al. discussed above.
Virtually all of the studied materials showed a band of absorption between about 1300 nanometers and about 1500 nanometers. Another absorption peak was observed at about 1900 nanometers. From these results it was concluded that neither the proteins present in cornea and lens tissue nor hyaloronic acid played an important role in determining infrared absorption. It appears, instead, that the water content of ocular media and the thickness of the water-containing structures are the determinative factors in near-infrared absorption.
2. In choosing the wavelengths at which clinical studies involving the Nd:YAG laser treatments were to be carried out, the published infrared absorption characteristics of methyl methacrylate were considered, inasmuch as intraocular prosthetic lenses are commonly made of this material. Data published by a principal manufacturer of this material, Rohm & Haas Company, indicated that there an absorption minimum existed at about 1300 nanometers, while an absorption maximum (absorption=40-50%) appeared at about 1800 nanometers. Because a principal use of the Nd:YAG laser described herein is to perform capsulotomies, i.e., rupture of secondary membranes subsequent to extracapsular extraction of the lens, and because intraocular lenses are frequently implanted after such extractions, it was decided to conduct further work with laser light wavelengths in the region of about 1300 nanometers.
Equipment
As previously discussed, the commonly-available Nd:YAG laser emits light at a wavelength of 1064 nanometers. As also previously discussed, laser light of this wavelength is of great utility in disrupting membranes, but is capable of producing serious injury to the retina.
In order to conduct studies in the desired 1300-1310 nanometer wavelength range, it was necessary to utilize the Nd:YAG laser apparatus manufactured by Laser Tek OY, a corporation of Finland. This device is known as the "P/V YAG" laser, and emits light in the desired wavelength range of 1300-1310 nanometers (hereinafter simply referred to as a wavelength of 1300 nanometers). It is capable of producing a pulsed laser beam having a pulse energy of 120 milli-Joules and a pulse duration of 40 nanoseconds. A series of from one to ten pulses may be emitted from the apparatus. The beam emitted from the apparatus was focused by using either a Zeiss slit lamp (beam diameter 50 microns) or a +20 diopter lens (beam diameter 200 microns). Additionally, it has been found useful to employ so-called "mode-locking" in the laser apparatus in order to keep the focal point of the beam steady and to eliminate so-called "side-beams" of undesired wavelengths.
All personnel involved in these studies were provided with infrared absorbing goggles.
Experiment #1
Wavelength Comparison
Two Nd:YAG lasers were employed in this study; one emitting at 1064 nanometers, the other at 1300 nanometers.
In this study, pigmented and non-pigmented rabbit eyes were irradiated while the rabbits were under general anesthesia and while their pupils were dilated. This was accomplished by directing an unfocused laser beam into the eyes for various time intervals up to five minutes in length.
Neither laser produced any lesion in non-pigmented rabbit eyes, even after the maximum exposure time. On the other hand, large retinal photocoagulation effects were observed in the pigmented eyes when irradiated with the laser emitting at the 1064 nanometer wavelength. It was found to be impossible to induce any retinal lesion with the P/V YAG laser, emitting at a wavelength of 1300 nanometers, regardless of the exposure time.
This study established that the 1300 nanometer wavelength laser could safely be used even when focused along the visual axis.
Experiment #2
Transmission Of The 1300 Nanometer Wavelength Beam Of The P/V YAG Laser In Various Media
First, as a calibration technique, the transmission of the P/V YAG laser beam in air was measured by directing a series of 25 milli-Joule pulses at a photoelectric plate.
After this measurement was made, the absorption of each of the following media was evaluated: water, normal saline, vitreous, and albumen (egg white). Each material was placed in a series of cells placed between the laser output and the photoelectric plate and irradiated with the pulsed P/V YAG laser (wavelength =1300 nanometers). These cells had thicknesses varying from 5 to 20 millimeters.
All materials behaved similarly in these tests, indicating that the absorption characteristics were due principally to the presence of water in the media. It was further shown that a thickness of 20 millimeters of water, or the equivalent, absorbed virtually all of the laser radiation.
Experiment #3
Effect Of The 1300 Nanometer Wavelength Laser Upon The Cornea
These studies were conducted in vitro using rabbit, pig and monkey eyes which had previously been enucleated and in vivo using the eyes of rabbits placed under general anesthesia by ketamine.
The laser was focused on the front of each eye by means of a +20 diopter lens. After irradiation, the corneas were excised approximately 2 to 3 millimeters behind the limbus. Next, the endothilium was stained with trypan blue and alizarium red in accordance with the method of Spence and Peyman. Selected specimens were then fixed in 2% formaldehyde and glutaraldehyde. Following fixation overnight, the specimens were dehydrated in alcohol and then embedded in paraffin. The tissue thus prepared was cut with a microtome, stained with hematoxyline and eosin and studied under a light microscope.
Corneas which had been irradiated in front of the focal point of the beam showed no damage to the corneal stroma or to the endothilium. However, in those corneas irradiated at the focal point of the beam, the incidence of the beam upon the cornea-air interface had resulted in a spark, due to plasma formation, and in a clearly audible shock wave.
The tissue studies showed that on a clear cornea, only minimal damage was caused by irradiation by between 10 and 20 pulses. In contrast, greatly enhanced absorption effects were observed where a moderate haze existed in the epithelium or in the stroma. Where corneal damage was observed, the reactions were highly variable, ranging from modest damage to the epithelium to substantial damage to the stroma. Corneal perforation often resulted from repeated exposure to the laser pulse. When damage extended to between one-half and two-thirds of the stromal thickness, damage to the endothelium was also observed.
These findings were confirmed by histological sectioning of the studied tissues.
This study confirmed that the 1300 nanometer wavelength laser could be utilized for the treatment of intraocular tissues, membranes and fluids without substantial corneal damage, provided that the cornea itself contained no more than a minimal amount of haze.
Experiment #4
Effect Of The 1300 Nanometer Wavelength Laser Upon The Iris
Exposure of the iris to the focused 1300 nanometer laser beam resulted in damage ranging from moderate pitting of the tissue surface to tissue rupture, with accompanying hemorrhage and external gas bubble formation.
No damage to the cornea was observed as a result of these procedures, except when the focus of the laser beam was at the periphery of the iris in an eye having a hazy cornea. This phenomenon, one which has been reported by Van der Zypen et al., Advances In Ophthalmology, vol. 39, pp. 59-180 (1979), led to the conclusion that plasma formation can occur slightly in front of the focal point of the beam, but only when there is sufficient haze in the tissue forward of the focal point to result in absorption of the beam.
In this experiment it was shown that photocoagulation treatment of the iris may successfully be completed with the 1300 nanometer wavelength laser so long as the beam may be focused through a portion of the cornea which will not absorb any substantial part of the laser energy.
Experiment #5
Effect of the 1300 Nanometer Wavelength Laser Upon the Lens
The laser beam was focused upon the lens in two different fashions. In some instances the beam was focused through the cornea and anterior chamber, while in the others the cornea was removed before irradiation.
This study, using clear lenses, demonstrated that the lens could not be damaged by the beam. The only exception to this finding occurred when the laser was focused at the pupillary margin, in which case the lens absorbed a portion of the resulting shock wave and was caused to rupture.
The utility of the 1300 nanometer wavelength laser for disrupting occluding membranes in the vitreous and for removing other foreign bodies from the vitreous is clearly shown by this study, inasmuch as the lens is shown to be transparent to laser radiation at this wavelength.
Experiment #6
Efficacy Of The 1300 Nanometer Wavelength Laser For Capsulotomies
For this study, secondary membranes were produced in pigmented eyes of rabbits and in the eyes of cynomolgus monkeys by performing extra-capsular extraction of the lens. During this procedure, two of the monkey eyes were fitted with a J-loop type of intraocular lens.
Approximately one to two months after the above procedure, each eye was irradiated with the laser, successfully rupturing the membrane in each case. The reaction to the laser beam ranged from minimal rupture of thick membranes, accompanied by gas bubble formation, to complete tissue loss.
Neither of the intraocular lenses was damaged.
The results of this experiment confirm the utility of the 1300 nanometer wavelength laser for treatments involving the removal of membranes which obstruct the passage of light to the retina (occluding membranes). Moreover, this method of removal has been demonstrated to be useful whether or not the natural or a prosthetic lens is present.
Experiment #7
Effect Of The 1300 Nanometer Wavelength Laser On The Retina
Initial attempts to focus the laser beam upon the retina by means of a standard or modified contact lens were unsuccessful, inasmuch as the surfaces of such lenses were damaged by the beam. Accordingly the study was conducted by directing the beam into the eyes either through the cornea or after removal of the cornea.
It was found to be impossible to produce a retinal lesion, either in this study or in Experiment #6 above, with the laser emitting radiation having a wavelength of 1300 nanometers.
This study confirmed the preliminary finding of Experiment #1 that the 1300 nanometer wavelength laser is essentially harmless to the fundus.
Experiment #8
Effect Of The 1300 Nanometer Wavelength Laser On Methyl Methacrylate
Two types of intraocular implants were examined in this study, one which contained ultraviolet-absorbing material and one which did not. The particular devices used were manufactured by the Cilco Company.
The implants were irradiated by placing them in front of the focal point of the laser beam, slightly in front of the focal point, and at the focal point. Those placed in front of the focal point suffered no damage, while those placed at or slightly in front of the focal point showed varying degrees of damage.
The above-described studies have shown that the method of treatment of the eye using the 1300 nanometer wavelength Nd:YAG laser overcomes the serious drawbacks inherent in previous laser surgical methods. The method of the invention enables the surgeon to perform a variety of membranectomy and photocoagulation procedures without causing damage to the cornea (except in the circumstances heretofore described), without damage to the natural or prosthetic lens (with the one exception noted) and without any damage whatsoever to the retina and its associated structures, regardless of the degree of exposure of the fundus to the laser radiation. Accordingly, capsulotomies, secondary membrane treatments and the other procedures herein described may, by the method of the present invention, be successfully performed without any substantial risk of visual impairment.
While the method of the present invention has been described with reference to various preferred forms thereof and with reference to the use of certain surgical procedures and equipment, it is to be understood that the full scope of our invention is defined by the following claims.
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An ophthalmic laser surgical method for treating or removing intraocular tissue anterior to the fundus while reducing the likelihood of photocoagulation damage to the fundus. Laser radiation in the infrared wavelength range is directed at the tissue to be treated or removed, the wavelength range being selected so as to minimize transmission of the laser radiation to the fundus by the ocular structures anterior to the retina.
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BACKGROUND OF THE INVENTION
The present invention relates to apparatus for forming a wrapped thread from a fiber supply, the process being commonly referred to as wrap spinning, and more particularly to such apparatus in which the speeds of drafting rolls feeding a binder spindle are electronically controlled to maintain respective speeds which are individually preselectable proportions of the speed of the spindle.
In the wrap spinning of yarn, fibers are drawn or "drafted" from a supply of the fibrous material by a succession of drafting rolls. The successive rolls are run at increasing speed so as to draw out the fibers to an appropriate weight. From the drafting rolls the fibers are fed through a spindle which contains a supply of a filament binder. The binder spindle, operating at a relatively high rotational speed, wraps the binder filament around the fiber sliver thereby completing the yarn. As is well understood by those skilled in the art, the characteristics of the finished yarn are affected by the relative speeds of the successive drafting rolls and also by the relative speed of the binder spindle.
In conventional wrap spinning apparatus, it is common for a large number of wrap spinning stations to be driven from a common motive source, usually a large, variable speed electric motor. The speed differential between successive drafting rolls is established either by gearing between the shafts driving the successive roll stages or by providing different motors which are manually adjusted to appropriate speeds. All binder spindles are typically driven through a tangential belt drive from a variable speed motor, speed of such motor being operator selectable.
In the event of a malfunction at one wrap spinning station, i.e., due to a yarn break or the need to refill a binder spindle, all of the commonly powered stations must be stopped to service the malfunctioning station. Further, the restarting procedure is difficult to achieve without inducing further breaks or a deviation in the characteristics of the yarn since it is difficult to bring all speeds up to the desired final operating speeds while maintaining the desired speed relationships.
Among the several objects of the present invention may be noted the provision of apparatus for forming a wrap thread from fibers in which the speeds of successive drafting rolls are electronically controlled through respective roll motors to operate at respective speeds which are individually preselectable proportions of the speed of the binder spindle; the provision of such apparatus in which the speed of the spindle is electronically controlled to a speed corresponding to the operating frequency of a variable oscillator; the provision of such apparatus which facilitates the independent operation of a plurality of wrap spinning stations; the provision of such apparatus which facilitates the restarting of a wrap spinning station following the break of a thread or the restocking of supply materials; the provision of such apparatus which is highly reliable and which is of relatively simple and inexpensive construction. Other objects and features will be in part apparent and in part pointed out hereinafter.
SUMMARY OF THE INVENTION
Apparatus according to the present invention operates to form a wrapped thread from a fiber supply. The thread is wrapped with binder material by a binder spindle which is driven, by a spindle motor, at a preselectable speed determined by a control circuit, the spindle motor being operated at a speed corresponding to the operating frequency of a variable oscillator within the control circuitry. First, second and third sets of rolls are provided for drawing the sliver and feeding it to the binder spindle, a respective roll motor being provided for each set of rolls. Respective control circuits are employed for operating each of the roll motors at a respective speed which is an individually preselectable proportion of the speed of the spindle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side view of wrap spinning apparatus constructed in accordance with the present invention;
FIG. 2 is a block diagram of control circuitry employed in operating various motors employed in the apparatus of FIG. 1;
FIGS. 3 and 4 are block diagrams of alternate control circuitry for controlling the motors in the FIG. 1 apparatus; and
FIG. 5 is a block diagram control circuitry for controlling multiple wrap spinning stations.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the binder spindle which wraps a filament binder on a fiber supply is indicated generally by reference character 11. As is conventional, the binder spindle carries a supply of the filament binder material and the fiber to be wrapped passes through the spindle as well as through the hollow shaft of a variable speed induction motor 13 which drives the spindle.
A drafting roll assembly is indicated generally by reference character 15. The drafting roll assembly comprises five pairs of rolls arranged in three sets, each set operating at a respective preselectable speed as described hereinafter. The right hand five rolls are designated 21 through 25 and left hand rolls are designated 31 through 35. The five rolls to the right are driven and are mounted in a fixed frame while the five rolls to the left are allowed to free wheel and are mounted in a movable clamping frame. The left five rolls can thus be moved out of engagement with the driven rolls, i.e. for feeding a new input sliver, and then brought back into clamping engagement with their corresponding driven rolls to effect drafting of the fiber.
As indicated diagrammatically in FIG. 1, the driving shafts for rolls 21 and 22 are linked by a timing belt 27 so that they rotate at the same speed and they are driven by a stepper motor 29. Similarly, the driving shafts for the rolls 23 and 24 are linked by a timing belt 37 and are driven by a stepper motor 39. The driving shaft for the last of the drafting rolls, i.e. the roll 25, is linked by timing belt 41 to the driving shaft of the output roll 26 and this set of rolls is driven by a stepper motor 43. The completed wrapped yarn is gathered up by a take-up reel 45 which is driven by a torque motor (not shown) so as to maintain a suitable tension on the yarn.
Referring now to FIG. 2, a variable frequency oscillator is indicated generally by reference character 51. The operating frequency of oscillator 51 is an operator selectable parameter and, in the particular embodiment illustrated, constitutes a single control parameter for varying the speed of the binder spindle and all drafting rolls simultaneously. As will be understood by those skilled in the art, this availability of a single control for all speeds along the path of a given fiber supply greatly facilitates start up procedures following shut down of a particular station. The output signal from the variable frequency oscillator is supplied to a power amplifier 53 which drives the induction motor 13 at a speed corresponding to the operating frequency of the oscillator 51.
A tachometer pulse generator 55 is provided for generating a pulsatile signal at a frequency corresponding to the rotational speed of the induction motor 13 and spindle 11. An optical interruptor module is preferred for this function but it should be understood that magnetic sensors might also be used. Similarly, while one pulse per revolution has been found to be entirely adequate, a higher number of pulses might also be utilized if it were desired to provide a finer degree of resolution in the adjustability of the speed of the drafting rolls, this adjustability being obtained as described hereinafter. The output signal from the tachometer pulse generator 55 is applied to a prescaler 57 which scales the pulse rate to a value appropriate for facilitating the subsequent control circuitry.
Each of the stepper motors 29, 39 and 43 is provided with a respective stepper driver circuit 61-63. The stepper driver circuits generate the necessary phased signals for application to the various windings of the stepper motors in conventional fashion in response to a control signal, usually designated the step signal, which is provided to the driver circuitry.
The step signals for controlling the driver circuits 61-63 are generated by respective pulse rate scalers 65-67 which are in turn driven by the signal from the tachometer pulse generator as adjusted in rate by the prescaler 57. While the prescaler 57 and the pulse rate scalers 65-67 may, in the embodiment illustrated, be constituted by simple digital counters or dividers, it should be understood that a variety of pulse rate scaling or frequency synthesis techniques are known in the electronics art and might also be utilized, depending upon the characteristics of the various components most economically available for assembling the system of the present invention. Similarly, while the particular embodiment illustrated contemplates fixed scaling ratios for any given installation, it should be understood that, by incorporating latches or memories int the divider or scaler circuitry, the frequency division ratios might be changed on the fly under operator or programmatic control.
In operation, it can be seen that a given wrap spinning station can be loaded with a fiber and a supply of filament binder material and then easily brought up to operating speed merely by progressively advancing the frequency of operation of the oscillator 51 since the speed of each pair of the drafting rolls will be scaled to the speed of the spindle 11, the actual rate of speed of each of the rolls being individually preselectable by means of the scaling values provided by the respective pulse rate scaler circuits 65-67.
As is understood by those skilled in the art, stepper motors of the type used to drive the drafting rolls in the FIG. 2 embodiment inherently tend to lock or synchronize with the driving signals so that effectively synchronous or phase locked operation is obtained, as long as certain rate and rate change limitations are not exceeded. Thus, the use of stepper motors is presently preferred. On the other hand, it should also be understood that closed loop feedback control might also be employed to cause the speeds of the drafting rolls to follow the speed of operation of the binder spindle. Such an embodiment is illustrated in FIG. 3.
With reference to FIG. 3, it can be seen that the drafting rolls 21, 23 and 26 are driven by servo motors 71-73 rather than the stepper motors of the embodiment of FIG. 2. Each of the servo motors 71-73 is provided with a respective power amplifier 75-77, the power amplifiers in turn being controlled from respective phase comparator circuits 81-83. In this embodiment the output shaft of each of the servo motors is provided with a respective tachometer pulse generator 85-87, the output of each pulse generator being applied as one input to the respective phase comparator 81-83. The other input to each phase comparator is the pulsatile output signal from the respective pulse rate scaler 65-67. As will be understood by those skilled in the control art, this arrangement will provide closed loop positional control of the drive shafts for the successive drafting rolls, the speed of each roll being thereby controlled as a respective preselected proportion of the operating speed of the spindle as measured by the tachometer pulse generator 55.
Similarly, while it is currently preferred to utilize a tachometer pulse generator to directly measure the speed of the spindle thereby to precisely control speeds of the various drafting rolls, it should be understood that the output signal from the variable frequency oscillator 51 is, in fact, a quite good representation or indication of this speed, since it is this parameter which controls or varies spindle speed. Thus, rather than using a separate pulse generator, it should be understood that both the speeds of the drafting rolls and the speed of the binder spindle could be slaved directly to the variable oscillator. Such a system, otherwise similar to the open loop stepper motor version of FIG. 2, is illustrated in FIG. 4. This embodiment is similar to the FIG. 2 embodiment except that the input signal to the prescaler 57 is taken from the variable frequency oscillator 51 rather than from a tachometer pulse generator associated with the binder spindle. As will be understood, the scaling values provided by the prescaler and/or the scaler 65-67 will be adjusted or determined by the various operating frequencies required by the several components of the system. These scaling values, however, are relatively easily preselectable as is understood by those skilled in the control circuitry art.
In installations where a large number of stations are manufacturing the same product, it has been found advantageous to drive multiple spindles from a common oscillator/amplifier combination during steady state operations and to provide an auxiliary oscillator and power amplifier for allowing an individual station to be stopped and then be brought up to the desired speed. Such an arrangement is illustrated in FIG. 5. The overall system illustrated in FIG. 5 comprises a plurality of thread wrapping stations each having their own spindles 11A-11G and driving motors 13A-13G. Each wrapping station is also provided with stepper motors and stepper motor control circuitry, designated generally by reference characters 81A-81G, for driving the corresponding fiber drawing rolls at that station. The several stepper motor control circuitries 81A-81G may, for example, each be essentially identical to the corresponding portion of the circuit shown in FIG. 2.
A main variable frequency oscillator 83 drives a main power amplifier 85 having sufficient capacity to drive all of the spindle motors 13A-13G in the multi-station system. An auxiliary variable frequency oscillator 87 is provided which drives an auxiliary power amplifier 89 having sufficient capacity to drive one or two of the spindle motors. Each of the spindle motors 13A-13G can be connected to either the main power amplifier 85 or to the auxiliary power amplifier 89 or it can be disconnected from both by means of a suitable switch, these switches being designated by reference characters 91A-91G.
During normal running, all of the spindle motors 13A-13G will be connected to the main power amplifier 85 so that the character of the product is uniformly determined by the setting of the main variable frequency oscillator 83. However, if the thread at one station breaks, it can be disconnected from either of the power amplifiers and allowed to come to a stop. As will be understood, the speeds of the corresponding draw rolls will continue to scale to the spindle speed as it decelerates, since each station has its own control circuitry for the stepper motors which drive the draw rolls. When the station has been re-threaded, the spindle can be switched over to the auxiliary power amplifier 89 and the frequency of the auxiliary VFO 87 can be ramped up to bring the station up to a speed which matches that of the other stations. At this point, the re-started station can be switched back over to the main power amplifier 85.
At the start of the day or work shift, it is not necessary to bring the individual stations up to speed individually with the auxiliary VFO 85 but, rather, the main VFO 83 can be ramped up to speed, assuming all the stations are properly threaded and otherwise ready to go.
In view of the foregoing, it may be seen that several objects of the present invention are achieved and other advantageous results have been attained.
As various changes could be made in the above constructions without departing from the scope of the invention, it should be understood that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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In the thread wrapping apparatus disclosed herein a binder spindle is driven by control circuit at a speed corresponding to the operating frequency of a variable oscillator. First, second and third sets of drafting rolls which draw and feed a sliver of fibers to the binder spindle are driven by respective stepper motors through control circuits which operate each of the motors at a respective speed which is an individually preselectable proportion of the speed of the spindle.
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BACKGROUND
This disclosure relates to a tooling fixture used, for example, in an automated welding operation.
Tooling fixtures are frequently used in automated assembly processes, such as welding, riveting and clinching, to hold a workpiece during the operation. In one example, one or more tooling fixtures are indexed between various stations, for example, by using a vertical rotary table that operates in a ferris-wheel fashion, a linear sliding assembly, or a rotary table that operates in a horizontal plane. Often a worker will load and unload the workpiece to and from a tooling fixture at one station, and a robot will perform various operations on the workpiece mounted on the tooling fixture at another station. Trunnions are sometimes used to rotate the tooling fixture to a desired position for the worker and/or robot.
Typically, various locators, clamps and sensors are used to hold the part and detect the presence of the part to ensure proper positioning prior to performing operations on the workpiece. Tooling fixtures used for welding operations may also include components that transmit welding current, such as the workpiece lead, or provide cooling water and/or electrical or pneumatic connections.
Typical prior art welding fixtures present several problems. First, typical welding fixtures are highly customized such that they require significant reworking when being updated for a new workpiece, or the welding fixture must be scrapped. Second, it is difficult to accurately locate the various tooling such as locators, clamps and sensors within the welding fixture. This increases down time when the welding fixture is reconfigured for a new workpiece. Third, it is difficult to locate the welding fixture relative to any support structure, such as trunnions. The welding fixture must be accurately located relative the trunnions to prevent binding as the welding fixture is rotated into the desired position. Fourth, large portions of the electric and pneumatic lines are left exposed, which subjects them to damage when performing operations on the workpiece, for example, from welding sparks.
What are needed are more modular welding fixtures enabling quick and accurate positioning of both the tooling relative to the welding fixture and the welding fixture relative to the trunnions. It is also desirable to provide a welding fixture that provides better protection for electrical and pneumatic lines, for example.
SUMMARY
A tooling fixture is disclosed that includes a weldment having spaced apart lateral members interconnected by opposing side members. Spaced apart trunnions support the side members for rotation about an axis, in one example. A locating pin is arranged between each side member and trunnions to enable quick and accurate location of the tooling fixture relative to the trunnions. The pins are at a right angle relative to the axis, in one example.
Tooling plates are removable secured to each of the lateral members. Adjustable brackets are secured to the tooling plates and support tooling that cooperates with a workpiece supported on the tooling fixture. In one example, jack blocks, shims, squaring plates and stops are used to permit precise adjustment and repeatable relocation of the tooling in three directions.
The various locating features enable the tooling fixture to be removed from the work area and taken to a remote location for rework. The tooling can be quickly repositioned and verified at the remote location, for example, by using a coordinate measurement machine. The reworked tooling fixture can then be accurately mounted on the trunnions.
These and other features of the disclosure can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an example welding operation work area using an example welding fixture in a rotary table configuration.
FIG. 2 is a partially exploded perspective view of the welding fixture supported by trunnions.
FIG. 3 is a perspective view of example tooling mounted on opposing tooling plates, which are to be secured to the welding fixture.
FIG. 4 is a top elevational view of the tooling shown in FIG. 3 with the tooling plates secured to the welding fixture.
FIG. 5 is an exploded perspective view of an example bracket assembly used to secure the tooling to the tooling plate.
FIG. 6 is a partially exploded perspective bottom view of the welding fixture shown in FIG. 4 without the brackets or tooling.
FIG. 6A is an enlarged partially broken view of a connection panel.
DETAILED DESCRIPTION
An example welding operation work area 10 is shown schematically in FIG. 1 . A workpiece 14 , such as a vehicle bumper, is retained by a welding assembly 12 . A robot 16 performs various operations upon the workpiece 14 , such as spot welding.
The example welding assembly 12 includes a base 20 supporting a turntable 22 . A framework 24 supported on the turntable 22 and includes modular tooling fixture weldments, or tooling fixtures 26 , mounted on opposing sides of the framework 24 . During operation, a worker loads and/or unloads the workpiece 14 at one station on one of the tooling fixtures 26 , and the robot 16 welds the workpiece 14 with its tool 18 on the other tooling fixture 26 at another station. Although the example illustrates a rotary table having a pair of tooling fixtures, it should be understood that the modular tooling fixture 26 can be used in other welding assembly configurations. Furthermore, the example tooling fixture 26 can be used in operation other than welding.
In the example arrangement, a pair of arms 28 is secured to the framework 24 to support each of the tooling fixtures 26 . The arms 28 include trunnions 30 that rotate the tooling fixtures 26 about an axis A to move the workpiece 14 in a desired position relative to the robot 16 and/or worker. At least one of the trunnions 30 for each tooling fixture 26 includes a headstock 32 having a motor 34 that rotationally drives the tooling fixture 26 about the axis A. The other trunnion 30 rotationally supports the other side of the tooling fixture 26 .
Referring to FIGS. 1 and 2 , the example modular tooling fixture 26 is a box-shaped structure that includes side members 36 welded to spaced apart lateral members 38 . In one example, the trunnions 30 include supports 40 having a pad 42 . The side members 36 are supported by the pad 42 and secured relative thereto. The side members 36 must be located precisely relative to the pads 42 so that the tooling fixture 26 does not bind as the motor 34 rotates the fixture assembly 26 about the axis A. To this end, the side members 36 include locating plates 44 , which includes various locating features that will be discussed in more detail below.
Referring to FIGS. 2-4 and 6 , the lateral members 38 include tooling plate mounts 46 to which tooling plates 48 are secured. Brackets 58 , which support tooling 50 , are secured to the tooling plates 48 in desired positions. It is desirable to quickly and precisely locate the tooling 50 for a particular workpiece 14 to reduce maintenance time and cost as well as the cost associated with part changeovers.
Referring to FIG. 3 , typical tooling 50 employed for retaining the workpiece 14 includes locators 56 and clamps 54 , which hold the workpiece 14 in a desired position to ensure that the tool 18 engages the workpiece 14 at the desired locations. Shaping cylinders 52 are also employed in one example to exert forces on the workpiece 14 during welding operations to prevent distortion of the workpiece 14 from heat during welding.
Referring to FIGS. 4 and 5 , the example brackets 58 are multi-piece components that are adjustable relative to one another to enable quick and easy position adjustments of the tooling 50 . In one example, a first plate 60 is secured to and arranged generally horizontally relative to the tooling plate 48 . A second plate 62 extends from the first plate 60 at a right angle, for example. The tooling plate 48 includes multiple holes 70 for receiving fastener 64 , which are threaded bolts, for example, that extend through enlarged holes 68 in the first plate 60 . Washers 66 are arranged between the fastener 64 and the first plate 60 . In one example, the washers 66 are relatively thick to distribute the clamping load exerted by the fastener 64 on the first plate 60 . The enlarged holes 68 have a diameter that is substantially larger than the diameter of the fastener 64 to enable adjustment of the bracket 58 in a plane X-Y corresponding to the tooling plate 48 .
A jack block 72 is secured to the tooling plate 48 by fasteners 74 received by holes 75 . The fasteners 74 extend through enlarged holes 73 to permit adjustment of the jack block 72 . Fastener 76 extends through holes 77 in the jack block 72 to secure the first plate 60 to the jack block 72 . A shim 71 having notches 78 , which accommodate the fastener 76 , is arranged between the jack block 72 and the first plate 60 . In the example shown, shims 71 and jack blocks 72 are arranged on either side of the bracket 58 . The jack block 72 can be used to ensure that the first plate 60 can easily be secured in its previous location if removed for servicing, such as a tooling change.
In one example method of adjustment, the fasteners 64 , 74 are loosened and the shims 71 are removed. The large clearance between the fasteners 64 , 74 and the enlarged holes 68 , 73 enables the bracket to be adjusted in both the first and second directions in the X-Y plane. Once the bracket 58 is in a desired position, the fasteners 64 are tightened to secure the bracket 58 to the tooling plate 48 . New shims 71 , if necessary, are machined to a desired thickness for placement between the jack blocks 72 and the first plate 60 . The fasteners 76 are tightened to secure the jack blocks 72 and first plate 60 to one another. The bracket 58 can then be removed by leaving the jack blocks 72 secured and by removing the fasteners 64 , 76 and shims 71 . The jack blocks 72 and replacement of the fasteners 76 locate the bracket 58 in the same Y position, and replacing the shims 71 locates the bracket 58 in the same X position. In this manner, the bracket 58 can be removed and replaced quickly and accurately.
A tooling pad 86 supports the tooling 50 relative to the bracket 58 using fasteners 92 that extend through washers 66 and enlarged holes 88 to threaded holes 89 . Squaring plates 80 are used on either side of the tooling pad 86 to locate and square the tooling pad 86 relative to the second plate 62 and prevent adjustment of the tooling pad 86 in the Y direction. In the example, fasteners 82 extend through washers 84 and enlarged holes 81 and are received in holes 83 to secure the squaring plates 80 to the tooling pad 86 . One side of the squaring plate 80 is secured to the second plate 62 using fasteners (not shown) and does not provide adjustability of the squaring plate 80 relative to the second plate 62 in the example. The squaring plate 80 permits the tooling pad 86 to be slid and adjusted in the Z direction.
A jack block 72 and shim 71 may also be used adjacent to the tooling pad 86 to set the desired Z position. A stop 90 limits the adjustment of the tooling pad 86 in the Z direction and can be used to quickly relocate the tooling pad 86 relative to the bracket 58 subsequent to removal to obtain the desired Z position provided by the shim 71 , similar to the method described above. The fasteners 82 , 92 are loosened to permit adjustment of the tooling pad in the Z direction.
The tooling 50 can be positioned at a remote location by placing the tooling fixture 26 on a coordinate measurement machine. The brackets 58 and their tooling 50 can be adjusted and verified before the tooling fixture is mounted onto the framework 24 .
Referring to FIGS. 2 and 6 , the modular tooling fixture 26 includes locating features that facilitate precise alignment of the tooling fixture 26 relative to the pads 42 associated with the trunnions 30 . This ensures that the tooling fixture 26 can be quickly and precisely positioned relative to the trunnions 30 to prevent binding of the tooling fixture 26 as it rotates about the axis A. As a result, the tooling fixture 26 can be removed from the work area for more rapid or cost effective retooling or maintenance at a remote location.
A plate 94 is secured to each of the side members 36 , such as by welding. An insulating sheet 96 is arranged between the plate 94 and the locating plate 44 to prevent welding current from passing through the tooling fixture 26 and into the rest of the welding assembly 12 . Nuts 98 are captured in a backside of the locating plate 44 . The nuts 98 includes bosses 100 that extend through and are located relative to holes 101 in the locating plate 44 . Fasteners 99 extend through holes in the pads 42 and are received by the nuts 98 to secure the tooling fixture 26 to the pads 42 .
Insulating tubes 102 extend through holes in the locating plate 44 , insulating sheet 96 and plate 98 to precisely locate the locating plate 44 relative to the plate 94 . Fasteners 105 extend through the insulating tubes 102 secure the locating plate 44 relative to the plate 94 . Insulating washers 104 are arranged between the fasteners 105 and the locating plate 44 .
Bushings 106 are received by holes 107 in the locating plate 44 and support locating pins 110 ( FIG. 2 ) extending from each pad 42 . In one example, the bushings 106 are only received in the locating plate 44 and are isolated from the plate 94 by the insulating sheet 96 . This is desirable, for example, since the bushings 106 are subject to impact forces and wear when the tooling fixtures 26 are located and secured relative to the pads 42 . A locating pin 108 may also be provided on the plate 94 and received in a corresponding hole 109 in the pads 42 .
In the example tooling fixture 26 , the pins 108 , 110 and their corresponding holes 109 , 106 are arranged transverse to the axis A. The pins 108 , 110 are arranged perpendicularly, for example, relative to a plane P provided by the tooling fixture 26 . In this manner, the tooling fixture 26 can be raised vertically off and lowered vertically on the pads 42 during dismounting and mounting.
Referring to FIG. 6 , the tooling fixtures 26 includes enclosures 112 adjacent to the tooling plate 48 for protecting various tooling wires and lines from damage, for example, during workpiece loading and unloading and from welding sparks. Enclosure 112 includes walls 114 that provide a cavity 125 for housing the wires and lines. Access panels 116 are movable relative to the lateral members 38 about hinges 118 to an open position, providing access to the wires and lines within the cavity 125 . The access panels 116 are retained in a closed position by latches 120 . The side members 36 include access holes 122 that enable the wires and lines to be more easily routed through a passage 123 in the side members 36 between the lateral members 38 from an area exterior to the tooling fixture 26 .
Referring to FIGS. 6 and 6A , the enclosure 112 includes a connection panel 128 that provides access between the tooling 50 and the cavity 125 provided by the enclosure 112 . The connection panel 124 includes knock-outs 126 that when removed provide holes 128 . A connector 130 can be mounted within each hole 128 , for example, or the wires/lines 132 can be passed through the holes 128 from the cavity 125 to an area exterior to the tooling fixture 26 . The connector 130 is a quick connect pneumatic fitting, in one example.
In one example, the tooling fixtures 26 include a valve enclosure 134 , shown in FIG. 6 . The valve enclosure 134 at least partially encloses and protects valves 136 that are used to selectively actuate the cylinders 52 and clamps 54 , for example.
Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine their true scope and content.
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A tooling fixture is disclosed that includes a weldment having spaced apart lateral members interconnected by opposing side members. Spaced apart trunnions support the side members for rotation about an axis, in one example. A locating pin is arranged between each side member and trunnions to enable quick and accurate location of the tooling fixture relative to the trunnions. The pins are at a right angle relative to the axis, in one example. Tooling plates are removable secured to each of the lateral members. Adjustable brackets are secured to the tooling plates and support tooling that cooperates with a workpiece supported on the tooling fixture. In one example, jack blocks, shims, squaring plates and stops are used to permit precise adjustment and repeatable relocation of the tooling in three directions.
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BACKGROUND OF THE INVENTION
The present invention relates to an electroplating bath for the deposition of white palladium metal on various surfaces. More particularly, the invention is concerned with baths for producing thin deposits of white palladium metal.
As is known in the art, the use of conventional palladium baths produces deposits which are grey in color. There are rhodium baths, on the other hand, known to produce white deposits which are very useful in the decorative art industries. In view of the relatively high cost of rhodium as compared to palladium, it would be desirable to be able to obtain a white finish from palladium baths as a substitute for the rhodium finishes now being employed. Previous attempts to produce a white palladium metal deposit were unsuccessful because the deposit was not white enough for the intended purposes, e.g., as a substitute for the conventional white rhodium deposits. It would also be useful for commercial purposes to be able to obtain readily thin, white deposits of palladium metal.
U.S. Pat. No. 330,149 which issued to Pilet et al. 1885, does mention the production of a "white palladium deposit". The electroplating bath of Pitel et al. contained palladium chloride, ammonium phosphate, sodium phosphate or ammonia, and, optionally, benzoic acid. The operating pH of the bath is not disclosed, although it is stated that ammonia is "boiled" off and "the liquid which was alkaline, becomes slightly acid". As indicated, the use of benzoic acid is disclosed to be optional, but the patentees disclose that it bleaches the deposit and makes the deposit more striking on iron and steel.
Electroplating baths designed to improve the brightness of palladium or palladium alloy deposits on metal substrates are also known in the art. See, for example, U.S. Pat. No. 4,098,656, which issued to Deuber in 1978. In this patent the improved brightness is achieved by utilizing in the bath both a Class I and a Class II organic brightener and an adjusted pH range of from 4.5 to 12.
In the drawings, the single FIGURE is a graph which illustrates the whiteness of the palladium deposits of the present invention as compared to those of the prior art.
SUMMARY OF THE INVENTION
In accordance with the present invention it has now been discovered that thin white palladium metal deposits can be readily obtained from an electroplating bath formed from a bath soluble source of palladium and an ammonium salt, where the pH is within the range of about 8 to 10. The use of a phosphate matrix is preferred, since it results in superior whiteness. However, it should be understood that ammonium sulfate, for example, also gives acceptable results.
A further essential feature of the present invention is the need to have ammonium ions present in the system as part of the conductive salt and to use them as well for adjusting the pH, preferably raising the pH to about 9. It was found that if the bath contained disodium phosphate instead of the ammonium phosphate, the desired white deposit was not attained. Unsatisfactory results were also obtained when the pH was adjusted with either sodium hydroxide or potassium hydroxide. It should be understood, however, that the presence of sodium ions does not have a detrimental effect on the deposit, since sodium tetraborate is an acceptable buffer for the system.
DETAILED DESCRIPTION OF THE INVENTION
The bath soluble source of the palladium metal in the electroplating bath of this invention may be any palladium amine complex, such as the nitrate, nitrite, chloride, sufate and sulfite complexes. Typical of such complexes which may be used are palladium diaminodinitrite and palladosamine chloride, with palladium diaminodinitrite being preferred. The palladium content of the plating bath will be at least sufficient to deposit palladium on the substrate when the bath is electrolyzed but less than that which will cause darkening of the deposit. Typically, the palladium concentration will be about 0.1 to 20 grams/liter, with concentrations of about 1 to 6 grams/liter being preferred.
The conductive salt may be any bath soluble ammonium-containing inorganic salt, such as dibasic ammonium phosphate, ammonium sulfate, ammonium chloride, and the like. Mixtures of such salts may also be utilized. The amount of the ammonium salt in the plating bath will be at least that which will provide sufficient conductivity to the bath to effect the palladium electrodeposition, up to the maximum solubility of the salt in the bath. Typically, the ammonia conducting salt will be present in an amount of about 30 to 120 grams/liter, with amounts of about 50 to 100 grams/liter being preferred.
As discussed above, the third essential material employed in formulating the electroplating bath of this invention is ammonium hydroxide. This compound is used in an amount sufficient to raise the pH of the bath to the desired range, i.e. about 8 to 10 and preferably about 9 to 9.5. In general, the ammonium hydroxide is employed in amounts ranging from about 10 to 50 ml per liter of the plating bath.
Buffers such as ammonium biborate, sodium tetraborate, trisodium phosphate, and the like may be employed to ensure that the desired pH is maintained in the plating bath during plating. The amount of the buffering agent or agents employed in the plating bath may range from about 0 to 50 g/l, and preferably about 10 to 30 g/l.
The temperature of the palladium plating bath may be maintained between room temperature and 160° F. In order to avoid the emission of excess ammonia from the solution, the plating temperature will be preferably below about 130° F. For many purposes operations at room temperature are preferred. Current densities from about 0.1 to 50 ASF (i.e., about 0.01 to 5 Ad/dm 2 ) are suitable. In general, current densities of from 2 to 20 ASF, preferably about 10 ASF, may be employed.
A further feature of the present invention is to produce only thin deposits of palladium so as to further ensure the production of a white deposit. Thus, the deposit thickness may vary from about 0.01 to 0.5 microns, and preferably from 0.03 to 0.4 microns.
The "whiteness" characteristic of the present invention is quantified in terms of white light reflectivity measured by spectrophotometric methods such as utilizing a Perkin-Elmer 559 spectrophotometer and plating the deposits to be studied over 1 inch by 1 inch panels preplated with 0.5 mils copper and then 0.5 mils of nickel, hereinafter referred to as the nickel plated panels, to eliminate surface imperfections. The white light reflectivity of these panels is scanned in the transmittance mode from 400 to 700 nanometers against a magnesium oxide reference plate. The sample deposit scan is then compared to a similar scan of a rhodium deposit. Electroplating baths, having a pH of 9-9.5, according to the invention are as follows:
______________________________________Component Concentration______________________________________(A) Pd(NH.sub.3).sub.2 (NO.sub.2).sub.2 * 1 to 6 g/l (as Pd)(B) Conducting Salt 50 to 100 g/l(C) Ammonium Hydroxide 10 to 50 ml/l(D) Buffer 0 to 50 g/l______________________________________ *Palladium diaminodinitrite
The invention will be more fully understood from the following illustrative examples, wherein the temperatures are given in degrees centigrade.
EXAMPLE 1
A palladium electrolytic solution was prepared by dissolving the following ingredients in water:
______________________________________Component Concentration______________________________________Palladium Diaminodinitrite 2 g/l (as Pd)Dibasic Ammonium Phosphate 95 g/lAmmonium Hydroxide 24 ml/l______________________________________
The amount of ammonium hydroxide used in the above formulation adjusts the pH to about 9.2. Plating was performed at ambient temperature, a current density of 10 ASF for 45 seconds on a nickel plated panel, to produce a white palladium deposit having a thickness of 0.25-0.35 microns.
EXAMPLE 2
A plating bath similar to Example 1, but with the use of a buffer, was formulated as follows:
______________________________________Component Concentration______________________________________Palladium Diaminodinitrite 2 g/l (as Pd)Dibasic Ammonium Phosphate 96 g/lAmmonium Biborate 25 g/lAmmonium Hydroxide 24 ml/l______________________________________
The amount of ammonium hydroxide used in this formulation also adjusts the pH to about 9.2. Plating was performed at ambient temperature, a current density of 10 ASF for 45 seconds, on a nickel plated panel, to produce a white palladium deposit having a thickness of 0.25-0.35 microns. The ammonium biborate acted as a buffer to maintain the pH at the desired level.
EXAMPLE 3
A plating bath similar to that of Example 2, with the exception that sodium tetraborate was used as the buffering agent, was formulated as follows:
______________________________________Component Concentration______________________________________Palladium Diaminodinitrite 4 g/l (as Pd)Monobasic Ammonium Phosphate 50 g/lAmmonium Hydroxide 24 ml/lSodium Tetraborate 25 g/l______________________________________
The aqueous solution contained sufficient ammonium hydroxide to adjust the pH to 9. The plating operations were carried out under the same conditions as Examples 1 and 2 to produce a white palladium deposit having a thickness of 0.25-0.35 microns.
In the following table the white light reflectivity of the palladium deposits on the nickel-plated panels of Examples 1 through 3 was compared with a rhodium deposit on a nickel plated panel as well as deposits made in accordance with Example 3 of the Deuber U.S. Pat. No. 4,098,656 and the Pilet U.S. Pat. No. 330,149 (page 1, lines 77-102 and page 2, lines 1-8). The Deuber and Pilet deposits had a thickness of 0.25-0.35 microns. The Perkin-Elmer spectrophotometer and the test procedure described above were employed.
TABLE 1______________________________________ % REFLECTIVITYDEPOSIT 400 nm 500 nm 600 nm 700 nm______________________________________Rhodium 80.5 85.0 88.5 90.5Deuber 60.0 71.5 78.0 80.5Pilet 51.5 60.0 66.5 72.0Example 1 63.5 75.0 80.0 82.5Example 2 64.5 75.5 81.0 83.5Example 3 63.0 74.5 80.0 83.0______________________________________
The foregoing data reveal that the electroplating baths of this invention produce a significantly improved palladium metal deposit as to white light reflectivity when compared to both Deuber and Pilet. The visual difference in whiteness is so significant that for commercial applications it can be the difference between acceptance and rejection.
When the foregoing data are plotted, percentage reflectivity versus wavelength, as in the accompanying drawing, the resulting graph further reveals the significance between the results achieved by the practice of the present invention.
Scanning Electron Microscope (SEM) Micrographs were made of the deposit produced in Example 2 and those produced by the procedures of the Pilet et al and Deuber patents. These Micrographs show that the Pilet et al deposits have extensive dendritic deposits and surface roughness. The Deuber deposits, while showing somewhat reduced dendritic growth than Pilet et al, still have considerable surface roughness. In contrast, the deposit from Example 2, is very smooth with no dendritic deposits. This further illustrates the unique properties of the deposits produced by the present invention and indicates the correlation between the smoothness of the deposit and its white light reflectivity.
It will be further understood that the examples set forth above are illustrative only, and that the invention is subject to further changes and modifications within the broader aspects of the invention.
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Electroplating baths suitable for obtaining white deposits of palladium metal. The bath comprises diaminodinitrite, an ammonium salt, and a sufficient amount of ammonium hydroxide to obtain a bath pH of about 9. Buffers such as ammonium biborate may be employed to maintain the necessary bath pH during electroplating operations to produce a thin, white deposit of palladium metal. The process of using such electroplating baths to produce white deposits of palladium metal on substrates is also disclosed and claimed.
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FIELD OF THE INVENTION
The invention concerns a method for the correction of distortion of signals in an NMR (nuclear magnetic resonance) spectroscopy and/or imaging device whereby said signal distortion is caused by the switching of gradient magnetic fields and the eddy currents which said switching produces.
DESCRIPTION OF THE PRIOR ART
Correction methods for signal distortions due to the switching of gradient magnetic fields and the eddy currents associated with said switching are known in the art from the German laid open publication DE 3730148A1.
In an NMR spectroscopy and/or imaging device nuclear spins are subjected to a uniform and homogeneous magnetic field and are excited by means of a spin excitation signal from a transmitter. The transmitter emits a radio frequency electromagnetic wave whose frequency is such that there is a resonant matching to the natural Larmor precession frequency in the homogeneous magnetic field of those magnetic spins to be excited. After irradiation of the spin excitation signal the excited nuclear spins precess about the direction of the homogeneous magnetic field vector at a precession angle whose magnitude depends on the strength and duration of the spin excitation signal. If the homogeneous magnetic field is not constant in time but rather exhibits a time dependence then the precession frequency of the excited nuclear spins will change along with this time dependent homogeneous magnetic field. After the magnitude of the magnetic field again assumes the original constant value the precessing spins return to their original procession frequency. However the absolute phase of these spins is shifted with respect to the original phase by an amount depending on the sign, magnitude and duration of the time dependent portion of the B o magnetic field. A receiver is used to detect the free induction decay (FID) signal which consists of an oscillating part representing the precession frequency of the spins around the direction of the homogeneous magnetic field and an exponential-like envelope representing the relaxation of the spins due to interactions with the lattice (T1) or dipole-dipole interactions with other spins (T2). If detection of the FID signal is undertaken during a period of time in which the magnetic field is changing, the FID signal experiences an undesirable distortion which must be corrected or compensated for. An analogous situation obtains when, instead of the direct FID signal, an echo signal of a spin-echo sequence is detected.
NMR spectroscopy and/or imaging devices require gradient magnetic fields for either volume selective spectroscopy or imaging. The gradient magnetic fields are applied in order to encode certain volume regions of the sample and thereby allow for position sensitive measurements of the nuclear magnetic resonance signal. For three dimensional position measurement three gradient magnetic fields are required. Depending on the application, these fields are applied in sequences usually during differing time intervals and, in general, exhibit differing strengths and gradient directions. Inductive coupling of the current flowing through the coils generating these gradient magnetic fields to other conducting elements causes the current change associated with the switching on and off of a gradient magnetic field to induce current flow in said conducting elements and this current flow, in turn, produces its own magnetic fields. These subsequent magnetic fields are undesirable and, combined with the desired field, produce a total time dependent magnetic field which deviates from the optimum magnetic field for the purpose at hand. The symmetry properties of the generated eddy current magnetic fields reflect the geometry of the conducting elements as well as the symmetry properties of the primary switching field causing said eddy current fields. Particularly disturbing is the eddy current field monopole component, i.e. the uniform magnetic field B o component, although other components are also present and can also be disturbing as well. This time dependent change in the uniform magnetic field leads to the distortion of the FID or spin-echo signal discussed above. In DE 3730148 A1 the switching of gradient fields in a nuclear magnetic resonance imaging device and the associated production of eddy currents cause field distortions which result in a rapid decay of the echo signals associated with spin echo sequences. The desire, however, to utilize spin echo pulse sequences, in particular, sequences with many spin echos thereby requires a treatment or correction of the distortions due to these eddy current fields. In accordance with the method and procedure of DE 3730148 A1 the dephasing of the produced spin echo sequences due to the disturbing eddy current fields is compensated for by a rephasing condition which is imposed either between the first 90° pulse and the next 180° pulse of a spin echo sequence by changing the magnitude of the static magnetic B o field or by adjusting the time separation between the first 90° pulse and the subsequent 180° pulse to be one half of that between the subsequent 180° pulses.
The additional time dependent change in the main magnetic field which is required in order to compensate for the dephasing of the spin echo pulses is enacted through the use of an auxiliary correction coil which also produces a largely homogeneous static magnetic field in the same direction as the main field. Through the introduction of a pulse in this auxiliary coil rephasing of the spin echo pulse can be effected. For the rephasing condition to be satisfied, the time dependence of the auxiliary magnetic field is in and of itself unimportant: only the integral of the magnetic field strength must fulfill certain conditions. In particular the time integral of the magnetic field strength over the time interval between the first 90° pulse and the second 180° pulse has to be half as large as the time integral of the magnetic field strength over the interval between the 180° pulses.
The B o pulse disclosed by DE 3730148 A1 technique is effective and appropriate for the case of a spin echo pulse sequence since the main requirement is that the dephasing condition, on the average, be compensated for. However, the detailed behaviour of FID and spin-echo signals, in particular their phase distortion, reflect not only the average behaviour of the eddy current fields but also their specific time dependence, which, in this procedure is not taken into account.
Other methods for correcting distortions of signals due to eddy currents associated with the switching magnet field gradients are given in the Journal of Magnetic Resonance 90, page 264-278 (1990). This article concerns itself with the class of correction procedures known as preemphasis pulses. For these types of correction procedures, the time dependence of the switching current which is delivered to the magnetic field gradient is modified in such a fashion that the resulting magnetic field is the desired magnetic field. That is to say, the distortion of the magnetic field which would otherwise occur due to eddy currents, is compensated for by actually changing the current distribution and its time dependence fed into the switching gradient magnet in order to produce the gradient field desired. The required pulse current distribution is extracted through an analysis of the multi-exponential decaying eddy currents which lead to the undesired distortion of images and/or spectra. In particular, the correction current is determined through an analysis of the free induction decay signals, whereby both the time dependence of the gradient field and the B o shift associated therewith can be extracted. A multi-exponential fit through the measured time dependent behaviour of the gradient fields leads to the amplitudes and time constants of the various exponential decay currents caused by the eddy current fields. After compensation of the gradient field component is achieved, the time dependent shift in the B o field is measured and through further adjustment of exponential preemphasis current fit parameters, similarly corrected for. In order to effect the exact shape for the eddy current compensation pulses, a multi-exponential function is required.
Such preemphasis type corrections, which are basically intended to produce additional fields in order to compensate for the field distortions caused by the eddy currents, require complicated hardware capable of simulating multi-exponential current distributions. Such methods are difficult to realize and of limited effectiveness, in particular as is usually the case in magnetic resonance imaging tomography, when three perpendicular gradient fields with various strengths and time dependences must be compensated for.
Other techniques for the correction of signal distortion from B o field shifts due to eddy currents effectively involve a software deconvolution of the distorted signal. As discussed in Journal of Magnetic Resonance 69, 151-155 (1986) such software correction measurements can allow for the effective removal or correction of time dependent field shifts following gradient pulses. The correction term must be evaluated individually for each gradient pulse sequence and is then applied to all subsequent data taken with this pulse sequence. In such software correction procedures a reference spectrum is taken, for example, a water signal, under the influence of a certain sequence of gradient fields. The distorted reference resonance line is then essentially deconvoluted for the time dependent distortion due to the eddy current fields and, in this fashion, the signal distortion correction is extracted. The procedure is then verified by applying this software correction to the reference line itself. When the correction is properly applied the reference line shows a clean spectral shape without distortions. Once the correction algorithm has been optimized for the reference line, it is then applied to the other spectral lines. The procedure is therefore particularly suited for spectroscopic applications where an entire spectrum of lines is to be measured.
Software corrections of this nature can always be applied to spectra retroactively. However hardware corrections, where possible, are always preferable since they can be effected in real time, i.e. quickly, and have intrinsically superior signal to noise performance. Moreover the ability to perform a hardware correction does not preclude combining this correction with software enhancement techniques to thereby further improve performance.
Due to the above mentioned deficiences in prior art it is the purpose of the present invention to develop a method for the correction of distortions in an NMR spectroscopy and/or imaging apparatus induced by eddy current fields which is simple to effect, can be implemented in hardware, and does not require modification of currents flowing through gradient coils.
BRIEF SUMMARY OF THE INVENTION
The purpose according to the invention is achieved in that correction for the signal distortion is effected through a compensation of the signal by phase modulation of the transmitter and/or receiver. The invention takes advantage of the realization that the primary effect of the eddy current on the signal is a time dependent shift of the B o magnetic field which, in turn, leads to a time dependent phase modulation of the signal. The required correction is therefore essentially a phase modulation correction which can be applied in hardware at as early a stage as possible in order to correct the signal for the distortions due to eddy current fields. By enacting the correction as a hardware phase modulation of the transmitter and/or receiver signal, the signal emerging from the NMR apparatus is fully compensated for eddy current distortions prior to subsequent digitization and signal processing steps. In this fashion the correction is applied in hardware and at an earlier stage so that optimal signal to noise ratios and resolution performance can be effected in real time.
In a preferred embodiment of the invention the phase modulation is applied directly to the transmitter.
This measure has the advantage that the transmitter signal is phase modulated in such a fashion that the nuclear spins excited by the signal themselves experience a phase modulation which is such that distortions in the phase development of the signal which would otherwise occur as a result of the eddy currents are compensated for in the excitation of the nuclear spins themselves. In complicated pulse sequences nuclear spin systems are excited, focussed, and reexcited in a sequence of steps necessary to produce images or complicated spectroscopy. The phase and signal distortion resulting from eddy currents induced in previous portions of the pulse sequence therefore act as limitations to subsequent portions of the pulse sequence which degrade performance and limit possible applications. By correcting for eddy current distortions of the signal in the spin system itself the physics of this system is essentially "phase corrected" so that at a fundamental level, the spin system evolves as if the eddy current distortion never occurred.
In a variation of this embodiment the spin excitation signal is phase modulated in the presence of a gradient magnetic field.
In imaging sequences it is common to generate the spin excitation signal in the presence of a gradient, the so-called slice selection gradient. In this case eddy currents due to the switching-on of the slice selection gradient are present during the period of time in which the excitation pulse, in this case a slice excitation pulse, is irradiated. As a result, the spin excitation signal, which was tailored to effect a particular density distribution and thickness of excited spins for excitation in the presence of a slice selection gradient superimposed upon a constant B o magnetic field, due to the time dependent B o field, actually produces a distorted slice or slice density distribution. This undesirable excitation profile can be improved by phase modulation of the transmitter signal itself since, in this event, the spin system itself acts in proper phase relationship as if the time dependent magnetic field distortion due to eddy currents had never occurred.
In a further embodiment of the invention the FID signal is phase modulated.
This measure has the advantage that signal distortion in the detected FID signal is eliminated or greatly reduced thereby leading to improved signal-to-noise ratios and resolution. In this embodiment the phase modulation of the invention is actually a demodulation correction of unwanted phase modulations which had already occurred in this signal due to the presence of eddy currents leading to time dependent changes in the B o field.
In a particularly advantageous embodiment of the invention both the excitation signal and the FID signal are modulated.
This measure has the advantage that, by way of example, distortions of the slice selection excitation profile and/or of the time evolution of the spin system as well as phase distortion and resolution distortion effects related to the detection of a distorted FID signal can be compensated for.
In an embodiment of the method according to the invention a time dependent measurement of a fluctuation of the magnetic field is made for a given switching sequence and on the basis of this measurement the required phase demodulation for the particular sequence is extracted.
This measure has the advantage that the cause of the phase distortion, namely the time dependent shift of the magnetic field, is analytically evaluated and stored for subsequent use. Thereby the fundamental cause of the eddy current signal distortion namely the time changing magnetic field can be stored in a form which can be subsequently applied to any pulse sequence so that proper phase correction can be calculated and applied at any particular given time during subsequent pulse sequences.
In a variation of this embodiment the time dependence of the B o magnetic field is extracted by time dependent spherical harmonic expansion of the magnetic field.
This measure has the advantage that all general parameters of the magnetic field are in principal known. Spherical harmonic expansion is a most general manner of extracting all the necessary field information in order to provide a complete analysis of the distortion effects. The B o component, the component leading to the phase distortions which are to be corrected, can be extracted in a straightforward fashion from the full time dependence of the field and the spherical harmonic analysis.
Associated with the application of the method in accordance with the invention is an apparatus for carrying out said method which is characterized by a phase modulation interface unit with a digital NMR converter and an analog interface for effecting the required demodulation. This apparatus has the advantage that the required hardware modifications are included so that an existing NMR spectrometer or tomography apparatus can be retrofitted with the required hardware.
Further details of the invention are disclosed by and can be extracted from the following figures. Clearly these figures can be taken individually or combined with each other without departing from the framework of the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 The time variation of the Larmor frequency associated with the time variation of the B o magnetic field as a function of time following a three second preemphasized gradient pulse of 2.5 mT/m but without the modulation correction in accordance with the invention.
FIG. 2 The time variation of frequency of the NMR signal of FIG. 1 but following signal distortion removal in accordance with the invention.
FIG. 3 Block diagram of the utilization of a phase modulation unit in accordance with the invention to phase modulate the receiver signal.
FIG. 4 Block diagram of the utilization of a phase modulation unit in accordance with the invention to phase modulate the transmitter pulse.
FIG. 5 Block diagram of the phase modulation interference unit according to the invention in particular for use in phase modulation of the receiver.
FIG. 6a) A pulse spectrum from a water sample without any gradient pulses,
FIG. 6b) signal acquired as the same condition as in a) but 2 milliseconds after a 2.5 mT/m gradient pulse and without B o compensation according to the invention.
FIG. 6c) as in b) with the compensation scheme in accordance with the invention.
FIGS. 7a) and 7b) Sample positions utilized in the spherical harmonic analysis of the B field in accordance with the invention.
FIG. 8 Pulse sequence used to acquire eddy current field data in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the B o response of the system as reflected in the time dependence of the resonant Larmor frequency after a preemphasis y-gradient pulse has been applied. Data were taken with a modified BRUKER MSL 100 console and processed on a work station. The response at 30 temporal points was cubic spline interpolated to 60K points and numerically integrated to provide a digitized version of ##EQU1## where γ is the gyromagnetic ratio and σ(t) the time dependent signal phase shift due to eddy current induced time variation of B o . The free induction decay is of the form
S(t)=S.sub.0 exp (iwt+φ+σ(t)) exp (-t/T.sub.2.sup.*)(2)
where φ is a constant. The phase modulation σ(t) is, in accordance with the invention, negated and then applied to the receiver or transmitter reference phase. In this way the function to be applied for any sequence can be simply calculated from the B o harmonic for each of the three gradients at the appropriate switching points of a pulse sequence for given magnitudes of the gradient pulses. The timing for these calculations is slightly longer than the compilation time of the pulse program itself with its associated files.
After applying the correction in accordance with the invention to the receiver for the embodiment of FIGS. 3 and 5, the frequency shift of FIG. 1 is largely compensated f or as can be seen in FIG. 2. The residual oscillations are of high frequency character and, with suitable filtering, provide no significant degradation of lineshapes. Note, in particular, the largely expanded scale for the ordinate in FIG. 2. The large amplitude of the B o shift causing frequency and phase distortion of the signal has been largely compensated for using the phase demodulation method of the invention. The residual displacement of the frequency signal corresponds to approximately 3% of the original displacement.
FIG. 3 shows a block diagram of one embodiment of the invention in which the phase modulation is effected by means of a modulation of the receiver signal, whereby the embodiment is for use in a BRUKER MSL 100 spectrometer. In this embodiment the phase demodulation is triggered by TTL control lines synchronized with the gradient magnet switching. Control lines from the spectrometer feed a phase modulation interface unit 1, the details of which will be discussed in association with FIG. 5. The interface unit has two outputs in quadrature which are then fed into the "channel 5" modulator of the BRUKER MSL 100 system whose 100.16 MHz reference signal from the synthesizer is also represented in the figure. The reference signal output of the "channel 5" modulater thereby includes audio frequency phase modulation, and the modulated reference signal now becomes the new reference signal for the receiver. The preamplified NMR signal enters the receiver and is modulated to produce the audio frequency output signals of the quadrature detector. Clearly the standard BRUKER "channel 5" modulator system illustrated in FIG. 3 can be replaced with any industry standard reference modulator without departing from the framework of the present invention.
FIG. 4 shows a block diagram for effecting a phase modulation of the transmitter 6 and thereby of the spin excitation signal. The digital frequency synthesizer 5 normally used in an NMR spectroscopy or imaging apparatus for pulse programming of pulse shapes and durations as well as frequences, can be modified generally in software but, if necessary, also in hardware in order to effect, when driven by the phase modulation interface unit 1, the desired transmitter 6 phase modulation. Modern digital frequency synthesizers 5 allow for a very flexible programming of the phase of the transmitter 6 excitation signal, thereby allowing for a phase modulation to be easily enacted.
FIG. 5 shows greater detail of an embodiment of the phase modulation interface unit 1 used in the embodiment of FIG. 3 for receiver phase demodulation. This unit was used for testing purposes and consisted of PC based 386 SX system equipped with two 12 bit digital to analog converters 2 and an input/output card 4. The clock frequency was 33 MHz. The system could output a phase file at 50 μs sampling point intervals representing considerable oversampling of the phase signal and could respond with the delay of 5 to 10 μs to a spectrometer program gradient episode. The input/output card 4 consisted of two digital to analog converters each 12 bits and capable of 60,000 values per second each of which output into an analog interface 3 consisting of differential, level shift and gain amplifiers as well as a four pole Bessel filter whose transmission response was -3 dB at 50 kHz and an output buffer thereby providing two quadrature output phase modulation signals. As already mentioned, this phase modulation interface unit 1 is particularly useful for phase modulation of the receiver signal, but with appropriate modifications, could also be used to phase modulate the transmitter signal.
FIG. 6 shows a pulse spectrum acquired from a 27 cc spherical water sample 0.5 cm from isocenter along the z-axis using a surface coil transmitter/receiver coil. The acquisition time was approximately 200 ms. FIG. 6a shows the Fourier transformed signal without prior switching of a gradient magnet. 3 Hz of exponential line broadening was applied for the signal before Fourier transformation.
FIG. 6b shows a signal taken under the same conditions as in FIG. 6a except 2 ms after a 2.5 mT/m gradient pulse and without B o compensation according to the invention. The B o correction applied in accordance with the invention to the receiver which is associated with the residual B o field fluctuations of FIG. 2 leads to the results of FIG. 6c where the correction of the B o shift 2 ms following a preemphasized 100 ms 2.5 mT/m gradient pulse is clearly very good. The small side peaks in the corrected spectrum stem from the inability of the "channel 5" modulator to maintain constant RF fields when being phase modulated. This amplitude modulation of the reference resulted in small side band peaks; the origin of the peaks was verified by the use of various phase modulation patterns and spectral analysis of the reference signal. Clearly these small side peaks are residual and nonfundamental in nature and can be eliminated by proper modification of the modulation unit.
In a preferred embodiment of the invention, the time dependence of the B o shift is determined through a temporal spherical harmonic expansion of the magnetic field following the gradient pulse. This expansion gives the strength of the harmonic which has the same symmetry as the applied gradient and additionally provides data on more complex field harmonics. The most straightforward approach in obtaining a spherical harmonic expansion of the magnetic field is simply to measure the field at points on a spherical surface surrounding the magnet origin. The spherical harmonics take the form
B.sub.z.sbsb.nm =r.sup.n (a.sub.nm cos mφ+b.sub.nm sin mφ)P.sub.nm (cos Θ) (3)
and are solutions to Laplace's equation ∇ 2 B z =0. The field B z can be represented in terms of its spherical harmonic components B znm ##EQU2## where B znm is the spherical harmonic of order n and degree m, a nm and b nm are constants and r is the radial distance from the magnetic isocenter. P nm (cos θ) are the associated Legendre functions.
The spherical harmonic B znm and the surface spherical harmonic T nm where
T.sub.nm =(cos mφ+sin mφ)P.sub.nm (cos θ) (5)
have the property of being orthogonal to each other when integrated over the surface of the sphere ##EQU3## where u=cos θ. This integral provides the means by which the spherical harmonic coefficients a nm and b nm can be determined for each spherical harmonic B z .sbsb.nm. Substituting equations 3 and 5 into equation 6 gives ##EQU4## where B z .sbsb.nm has been replaced by the summation given in equation 4. The inner integral on the right hand side is evaluated by Fourier transforming B z (u,φ) with respect to φ for fixed u to give F(u), while the outer integral is evaluated using Gaussian numerical integration. That is ##EQU5## where W u are the Gauss weighting factors for each point u. The coefficients a and b can then be found by equating expressions 6 and 8. ##EQU6## where the superscripts c and s refer to cosine and sine Fourier transforms of the azimuthal data.
In experiments leading to the results of FIGS. 2 and 6, the harmonics were evaluated at 30 exponentially weighted temporal points, both during and after a long (3 s) gradient pulse and at 112 spatial positions in seven azimuthal plains over a sphere of 7 cm radius. The use of this type of field measurement provides a wealth of information concerning both the spatial and temporal response of the gradient magnet system.
FIG. 7 gives an example of the sample positions used for this spherical harmonic analysis. The field strengths were determined using a radio frequency (RF) probe consisting of seven water samples fixed in the positions indicated in FIG. 7a. The NMR resonance frequency of each sample was monitored by a small RF coil while a relay based switching system allowed for the selection of different coils. Azimutal positions in FIG. 7b were obtained by probe rotation. The water samples were 100 ml each and were mounted in a specially built probe and placed at the positions indicated in FIG. 7a. During the experiment the probe was rotated about the z-axis in 22.5° steps (FIG. 7b) until resonant frequencies from all 112 positions had been acquired.
As indicated in FIG. 8, the eddy field response following the application of a long (3 s) magnetic field gradient (Gy) of 5 mT/m was monitored by recording 30 free induction decays following excitations with the RF pulse train of FIG. 8 with delays τ of between 1 ms and 2.5 ms. Small tip angle RF excitation pulses were used in such a fashion that the free induction decays for a single coil could be obtained in a single measurement. For each free induction decay 256 complex data points were acquired in 1.28 ms. During this time the frequency and therefore the field was essentially constant. The delay between free induction decays was increased exponentially with time to allow for accurate fitting of exponentials to the resulting frequency data. Once the complete data set of 3,360 free induction decays was obtained, data were processed by calculating the frequency of each FID. This was done by zero-filling to 4K, Fourier transforming, and then picking the dominant peak position. Alternatively if the signal to noise ratio of the free induction decay was good, the frequency could be more accurately determined by measuring the total phase shift during the free induction decay.
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Temporal B o shifts in NMR spectroscopy and/or imaging systems arising from pulsed field gradient induced eddy currents result in the distortion of free induction decay signals. A method of compensation of this distortion through modulation of the sender and/or receiver signal in opposite concert with the induced B o shifts is introduced. The method has the advantage of having a fast response and of not altering the magnetic gradient field. (FIG. 4)
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NOTICE This invention was made with Government support under N00019-83-C-0166 awarded by Department of the Navy, Naval Air Systems Command. The Government has certain rights in this invention.
FIELD OF THE INVENTION
This invention relates generally to aircraft having relatively large rotors thereon, such as helicopters or tiltrotor aircraft. More particularly, but not by way of limitation, this invention relates to improved apparatus and method for folding and locking the rotor blades of rotary wing or tiltrotor aircraft wherein the blades are faired into the rotary drive hub.
BACKGROUND OF THE INVENTION
Rotary wing aircraft and tiltrotor aircraft are difficult to store due to the span covered by the relatively large rotors thereon. The problem has become particularly acute with the use of multi-rotor helicopters and with the advent of tiltrotor aircraft where the rotors are carried at the very tips of the wing. A large amount of space is required to store such aircraft and in some instances, such as on aircraft carriers, the space required for storing such aircraft with the rotors extended or deployed is not available.
With the early rotary wing aircraft, if folding was necessary, manual manipulation of the blades and lock pins retaining the blades was adequate. However, with larger aircraft and particularly with the tiltrotor aircraft where the blades are located very high and at the tips of the wing, power folding has become a virtual necessity.
U.S. Pat. No. 3,625,631 issued to Cecil E. Covington, et al. on Dec. 7, 1971. That patent describes a system for positioning pairs of rotor blades so that they are aligned parallel to the centerline of the fuselage. Since there are no wings on the aircraft, folding the rotor blades in this manner reduces the required storage area essentially to the width and length of the fuselage.
U.S. Pat. No. 3,749,515 issued July 31, 1973 to Cecil Covington, et al. The powered blade folding mechanism described in that patent, does fold one rotary blade relative to the other. Also, during the folding process a locking pin is withdrawn and reinserted automatically so that the blade will be locked in position when deployed.
It is contemplated in U.S. Pat. No. 3,749,515 that such power folding mechanism would be utilized on convert-a-planes so that the blades could be folded to reduce drag during level flight. In that type of aircraft, a separate propeller or propulsion means is utilized during horizontal flight so that the rotor blades are not used for this purpose. With the advent of the tiltrotor aircraft, the same power plant and same rotor blades are utilized for both horizontal and vertical flight. To convert from vertical flight to horizontal flight, the tiltrotors are rotated relative to the aircraft so that the rotors are oriented with the blades in the proper attitude to provide horizontal flight. To reduce the drag on the aircraft during horizontal flight, it is desirable to provide fairings over the rotor drive hub and over the connections between the blades and the rotor hubs. In the tiltrotor aircraft, it is virtually mandatory that such blades be arranged to be power folded if storage space is a consideration.
In order to power fold the blades of faired rotors, it is necessary to not only provide a lock which is automatically withdrawn before folding and which is reinserted after the blade is deployed, but it is also necessary to provide for the removal of a portion of the fairing or fairing door in the direction in which the blade is folded. It is also necessary that such fairing door be securely latched when the blade is deployed.
An additional problem, when the rotors are used in level flight, is that the blades need to be of an adjustable pitchtype. To control the position of the blades when folded and during storing on the tiltrotor-type aircraft, it is necessary that a lock be provided to prevent an inadvertent change in pitch angle.
Accordingly, an object of this invention is to provide an improved apparatus and method for power folding rotor blades that are of the variable pitch-type.
SUMMARY OF THE INVENTION
In one aspect, this invention provides apparatus for folding and locking an adjustable pitch rotor blade that comprises: a blade grip member connecting the blade to the rotor drive with the blade member being pivotal to adjust the pitch angle of the blade; a rotary actuator located in the grip member for pivoting the blade between deployed and folded positions; a blade lock on the grip member operably connected with moveable by the actuator for preventing inadvertent folding of the blade when the blade is in the deployed position; and a pitch lock on the grip member for preventing changing of the blade pitch angle when the blade is folded.
In another aspect, the invention contemplates a method of folding a variable pitch rotor blade having a folding apparatus enclosed in a fairing housing comprising the steps of: opening a fairing door forming part of the fairing housing to a position permitting the blade to fold; moving a blade lock pin to permit the blade to fold; inserting a pitch lock pin to prevent a change in the blade pitch angle; and pivoting the blade from a deployed position into a folded position.
BRIEF DESCRIPTION OF THE DRAWING
The foregoing and additional objects and advantages of the invention will become more apparent as the following detailed description is read in conjunction with the accompanying drawing wherein like reference characters denote like parts in all views and wherein:
FIG. 1 is a pictorial view of a tiltrotor aircraft incorporating powered, blade folding and locking apparatus that is constructed in accordance with the invention.
FIGS. 2a and 2b taken together illustrate the apparatus used for connecting the blade to the rotor drive and showing folding and locking apparatus that is constructed in accordance with the invention.
FIG. 3 is a side view of a portion of FIG. 2b with certain parts removed to show a cam utilized in the apparatus.
FIG. 4 is a view similar to FIG. 3, but showing an "overcenter" mechanism used in the apparatus.
FIG. 5 is a fragmentary view of a portion of the linkage showing a brake utilized in the device.
FIG. 6 is a pictorial view illustrating the folding and locking apparatus of the invention.
FIG. 7 is an enlarged, somewhat schematic view illustrating a lock pin utilized to lock the rotor blade in the deployed position.
FIG. 8 is a view similar to FIG. 4, but showing the apparatus in another operating position.
FIGS. 9a-98d illustrate a method according to the invention for folding the blade of the aircraft for storage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing and to FIG. 1 in particular, shown therein is a tiltrotor aircraft 10 generally designated by the reference character 10. The tiltrotor aircraft includes a centrally located fuselage assembly 12 having a wing assembly 14 affixed to the upper portion thereof and extending transversely with respect to the longitudinal axis of the fuselage 12. At each end of the wing assembly 14 there is provided a tiltrotor 16. Each tiltrotor 16 includes a nacelle 18 that is pivotally attached to the ends of the wing and encases an engine (not shown) for driving a rotor assembly 20. The rotor assemblies 20 each include a drive hub 22 encased in a fairing 24. Attached to the drive hub 22 are a plurality of rotor blades 26. As illustrated, the blades 26 have a circumferential spacing of about 120 degrees. The blades 26 are attached to the rotor drive hub 22 and the attachment thereof is covered by a fairing 28.
Enclosed within the fairing 28 of each rotor blade 26 is a blade grip member 30 pivotally connected to the hub 22 to permit variation in the pitch angle of the blades 26 as shown in FIGS. 2a and 2b. The rotor blades 26 are pivotally connected to the grip member 30 as is illustrated more clearly in FIGS. 5 and 7.
The rotor drive hubs 22 are powered by the engines (not shown) through shafts 32. To provide for the variation in the pitch angle of the blades 26, a lever arm 34 is mounted on each grip member 30. Each lever arm 34 is connected to a control link (not shown) which is actuated to cause the grip member 30 to rotate about the longitudinal axis of each blade 26.
Forming part of the lock and folding apparatus that is generally designated by the reference character 50 is a pitch lock assembly designated by the reference character 52. As shown in FIG. 2a, the pitch lock assembly 52 includes a pitch lock pin 54 slidingly mounted in a bracket 56 affixed to the grip member 30. Although not shown, it will be understood that the pin 54 will be inserted into an opening in the hub 22 which locks the grip member 30 to the hub 22 and prevents the rotation of the grip member 30 and the attached blade 26 about the axis of the blade. Connected to the pin 54 is a linkage 58 that is operably connected with a bell crank 60. As will be explained more fully hereinafter, actuation of the bell crank 60 at the appropriate time causes the linkage 58 to move the pin 54 into or out of locking engagement with the drive hub 22.
Referring again to FIGS. 6 and 8, it can be seen therein that the blade 26 is pivotally connected to the grip member 30 by a pair of spaced blade tangs 61 and a blade pivot pin 62 which extends therethrough. Mounted within the pivot pin 62 is a drive motor 64 which has planetary gear reducers 66 mounted on each end thereof. The gear reducers 66 each have a pair of output rings or members 68 and 70 that are arranged to move separately depending upon which is locked. The output rings 70 are mounted on the blade tangs 61 so that the blades 26 move with the output rings 70. The gear reducer 66 and output members 68 and 70 comprise a rotary actuator 71 for pivoting each blade 26.
The output ring 68 is connected by a linkage 72 with a bell crank 74 that changes the direction of motion of a linkage 76 that is also connected thereto. The linkage 76 is connected to a bell crank 78 carried by a shaft 80. It will be noted that the bell crank 60 associated with the pitch lock assembly 52 is also mounted on the shaft 80.
The motor 64 and the planetary reducer 66 comprise a rotary actuator for pivoting the blades 26. To control the movement of the output rings 68 and 70 of the planetary gear reducer 66, a pivotally mounted beam 82 carries a pair of cam followers 84 and 86 that engage the output members 68 and 70. The beam 82 is sized and arranged with respect to the output rings 68 and 70 so that the cam follower 84 remains in engagement with the output ring 68 and the cam follower 86 engages the outer surface of the output member 70.
In the deployed condition of the blade 26, the cam follower 86 is located in a detent (not shown) in the surface of the output member 70 preventing rotation of the member 70 while the output ring or member 68 is permitted to rotate in the direction of the arrow 88 (see FIG. 6) through an arc of about 54 degrees. After 54 degrees of travel of the gear reducer 66, the cam follower 84 drops into a recess or detent (not shown) in the surface of the output member 68 locking the member 68 against further movement. When this occurs, the cam follower 86 moves out of the detent in the ring 70 at which time the direction of rotation reverses and the blade 26 is folded toward the position illustrated in FIG. 8.
Although not previously mentioned, the blade 26 cannot fold until the door 90 in the fairing 28 is opened in the direction in which the blade 26 is to be folded. Also, it is necessary to securely latch the fairing door 90 in the closed position when the blade 26 is in the deployed position illustrated in FIG. 6. For this purpose, a latch member 92 is located on the output member 68 of the planetary gear 66. During the first few degrees of rotation of the output member 68, the latch 92 is rotated (compare FIGS. 6 and 8) to unlatch the door 90.
Opening and closing of the fairing door 90 is accomplished through door hinge members 94 which have one end attached to the fairing door 90 and the opposite end to a pivotal bell crank 96. The bell crank 96 is connected by a linkage 98 with a slotted bell crank 100 (see FIG. 3) which is mounted on shaft 80. The slotted bell crank 100 carries a cam follower 102 that rides in a fixed dwell cam 104.
As may be seen more clearly in FIG. 3, the dwell cam 104 includes a slot 106 which has a vertical portion 108 and a generally horizontal portion 110. The arrangement is such that as the first movement of the planetary output member 68 occurs, the slotted bell crank 100 is caused to rotate with the shaft 80. As this rotation occurs, the cam follower 102 rides upwardly in the vertical portion 108 of the dwell cam 104 and in the slotted bell crank 100. Accordingly, no motion occurs in the linkage 98 and no motion of the door hinge 94 occurs.
Also, during the first 54 degrees of rotary motion of the planetary output member 68, the shaft 80 drives the bell crank 60 in the counterclockwise direction as seen in FIG. 4 to move blade lock pin 114 out of locking engagement. The pin 114 is also illustrated in FIGS. 2b, 4, 6, 7 and 8.
In FIG. 7, it can be seen that the axis 116 of the lock pin 114 is disposed at an angle relative to the axis 118 of the blade 26. The slight angular disposition is preferred so that as the lock pin 114 moves into engagement with the tangs 61 on the rotor blade 26, a camming action occurs retaining the tang 61 of the blade 26 firmly against a blade stop member 118 located on the blade grip 30. Accordingly, and so long as the pin 114 is engaged as shown, the blade 26 is locked in the deployed position.
The blade lock pin 114 is connected by means of an over center mechanism 120 (see FIG. 3)to the bell crank 60. The over center mechanism 120 is provided so that when the pin 114 is in the locked position illustrated in FIGS. 2b, 4, 6 and 7, it cannot be inadvertently dislodged nor can the force of the blade 26 exerted thereon push the pin 114 out of the locked position. An adjustable stop 122 is provided so that the over center distance 124 of the over center mechanism 120 can be adjusted as desired.
FIG. 5 illustrates a brake 130 that is utilized to exert a frictional force against a bell crank 132 mounted on the shaft 80. The brake 130 includes a stacked spring 134 that urges friction brake members 136 and 138 into engagement with the bell crank 132.
The foregoing description refers primarily to a single folding and locking apparatus 50. It will be understood that each blade of the aircraft may be provided with such apparatus as desired or required.
FIGS. 9a through 9d illustrate schematically, a preferred method of folding the blades 26 on the tiltrotor aircraft 10 utilizing the folding and locking apparatus 50 which has been described in detail hereinbefore. As shown in FIG. 9a, the aircraft 10 has come to a stop on the ground, with the rotor blades 26 deployed in random fashion. In FIG. 9b the blades 26 have been rotated so that one of the blades 26 on each tiltrotor or nacelle 16 is generally aligned with the longitudinal axis of the wing 14. In FIG. 9c, it is shown that the remaining two blades 26 on each tiltrotor 16 have been folded so that they lie generally in juxtaposition alongside of the blades 26 which were initially aligned with the longitudinal axis of the wing 14.
If it is a disadvantage to have the tiltrotor 16 in the vertical position as illustrated in FIGS. 9a, b and c, the tiltrotors 16 can be tilted to a position wherein the blades 26 lie along and generally parallel to the leading edge of the wing 14 as shown in FIG. 9d.
From the foregoing, it can be seen that a substantial saving in storage area for the aircraft 10 has been accomplished. This becomes clearly apparent in viewing FIG. 9a as compared to FIG. 9d.
OPERATION OF THE PREFERRED EMBODIMENT
As previously mentioned, the folding and locking mechanism 50 is utilized to permit the aircraft 10 to be stored in a smaller space by folding of the rotor blades 26.
Assuming that the blades 26 are initially in the deployed position as illustrated in FIGS. 1, 6 and 9a, the rotary actuator 71 mechanism is actuated causing the motor 64 to rotate the planetary gears 66. When this occurs initially, the output member 70 is held in position by the beam 82 and the blade 26 remains stationary. However, the output ring 68 rotates counterclockwise, as seen in FIG. 6, pushing on linkage 72 and, through bell crank 74, pulling on linkage 76. Movement of linkage 76 rotates shaft 80 in the clockwise direction as seen in FIGS. 3, 4 and 8. When this occurs, the over center mechanism 120 immediately starts to withdraw the blade lock pin 114 from engagement with the blades 26 and the linkage 58 moves the pitch lock pin 54 into engagement with the rotor drive hub 22 locking the blade 26 against rotation in the pitch direction. When the blade lock pin 114 has been withdrawn sufficiently, the blade 26 is in condition to be folded.
Movement of the planetary member 68 in the clockwise direction also moves the fairing door latch 92 to the position illustrated in FIG. 8. This movement releases the fairing door 90 so that it can be opened.
During this same time period, the shaft 80 has rotated and attached the slotted linkage 100 in a clockwise direction moving the cam follower 102 upwardly in the vertical portion 108 of the slot 106 in the dwell cam 104. As previously mentioned, no motion occurs to the fairing door hinge 94 during this time period. However, upon reaching the horizontal portion 110 of the dwell cam 104, the linkage 98 is driven in the appropriate direction to cause the bell crank 96 to move the door hinge 94 in a counterclockwise direction as seen in FIG. 6 opening the fairing door 90 as shown in FIG. 8. The blade 26 is now in condition to be pivoted or folded.
Upon completion of the opening of the fairing door 90, the cam follower 84 drops into the detent provided in the planetary output member 68 locking that member against motion. As this occurs, the cam follower 86 moves out of the detent in the output member 70 and the planetary gear system move in a counterclockwise direction as seen in FIG. 6 and FIG. 8 moving the blade 26 to the folded position as shown in FIG. 8.
To prevent the inadvertent rotation of the shaft 80, the brake 130 engages the bell crank 132. The force necessary to overcome the brake 130 and cause rotation and movement of the shift 80 is exerted by the actuator 71.
When it is desired to deploy the blades 26, the rotary actuator 71 is again actuated. The planetary output member 70 is in the unlocked position and the planetary output member 68 is in the locked position, therefore, the blade 26 is first caused to pivot toward the deployed position illustrated in FIG. 6. The blade 26 pivots until it comes into engagement with the blade stop 118 located on the grip member 30. When this occurs, the cam follower 86 drops into the detent on the planetary output member 70 releasing the planetary member 68 so that it can rotate in the counterclockwise direction. Such rotation pulls the linkage 72 and pushes the linkage 76 due to the bell crank 74 and rotates the shaft 80 in the counterclockwise direction.
Since the cam follower 102 is on the flat portion 110 of the cam 104, the fairing door 90 is closed. Simultaneously, the bell crank 60 swings the over center mechanism 120 into position to move the lock pin 114 to the position illustrated in FIG. 7 locking the blade 26 against pivotal motion.
Simultaneously, the bell crank 60 moves in a direction to pull the linkage 58 away from the rotary drive hub 22 extracting the blade pitch lock pin 54 therefrom so that pitch adjustment of the blade 26 can occur.
The final action of redeploying the blade 26 occurs as the planetary output member 68 continues to rotate in the counterclockwise direction although no motion of the shaft 80 occurs due to the movement of the cam follower 102 through the vertical portion 108 of the slot 106. The final action is that the latch member 92 moves in engagement with the fairing door 90 latching it securely into the closed position.
It should be pointed out that on each of the blades 26 there is provided an upper and lower locking and folding mechanism which are essentially identical in construction. It should also be pointed out that although not described in detail, a number of sensors are located in the locking apparatus 50 that give warnings or signals related to the locked and unlocked condition of the various components of the blade locking and folding apparatus 50.
From the foregoing detailed description, it will be appreciated that the apparatus describes provides a powered, folding and locking apparatus that is effective to quickly and effectively fold and deploy the rotor blades of aircraft of the type described, thus providing an effective means of reducing the necessary storage area.
It will also be understood that only one embodiment has been described in detail hereinbefore and that many changes and modifications can be made thereto without departing from the spirit and scope of the invention.
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Folding and folding locking apparatus for rotor blades that includes a power actuator for rotating the blades and locking means for securing the blade in the deployed position and securing the blades against rotation of the pitch angle during and when the blades are folded. The apparatus also provides for the complete fairing of the blades at their connections with the rotary drive hub and provides a powered door in the fairing that can be opened and closed to permit the quick and easy folding and redeployment of the blades.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 13/002,729 filed on Jan. 5, 2011 which is a National Stage of International Application No. PCT/CN2008/001529 filed on Aug. 26, 2008, the entire contents of each of which are hereby incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to an access node device in an access network under an IPv6 environment, and more specifically, to a method and apparatus for forwarding packets in an access node device in an IPv6 access network.
DESCRIPTION OF THE RELATED ART
[0003] With the network evolution, the depletion of IPv4 addresses, and also more and more devices in the Customer Premises Network (CPN), such as the Home User network and the Enterprise Network, requiring to be Internet-enabled, an access network is beginning to its transition to support IPv6. The Broadband Forum has been working on standardization for evolving a Digital Subscriber Line (DSL) access network to be IPv6-enabled.
[0004] An Access Node (AN) is the first absolutely controlled device of an operator in the access network. Hence, checking validity of packets and removing invalid packets in the Access Node is of vital importance to network security of the operator. In an IPv4 access network, network security measures such as IP address anti-spoofing are implemented on the AN to secure the network and also avoid service theft. However, it is rather difficult to implement IP address anti-spoofing in an IPv6 environment in the same way as in IPv4. Reasons are presented below.
[0005] 1) As more and more devices are connected via the CPN to the AN of the operator, much more records for IP address anti-spoofing must be added to the AN, which will require the AN to have a high storage capacity and strong operation performance and further greatly increase the construction cost of access node devices in the IPv6 access network.
[0006] 2) Many User Terminals in the IPv6 CPN do not obtain IPv6 addresses from a network device such as a DHCPv6 server of the operator but form an IPv6 address list based on a stateless address auto-configuration mechanism or by interacting with a device, such as a Residential Gateway, using the local DHCPv6 server. Hence, the AN cannot obtain the IPv6 address list currently used by the User Terminals in the current CPN, let alone check validity of packets by checking whether the source IPv6 address in each packet is a currently used IPv6 address, just as it does in the IPv4 network.
SUMMARY OF THE INVENTION
[0007] Therefore, the present invention is proposed to solve the above technical problems that exist during implementing network security control, such as IP address anti-spoofing, in the IPv6 access network. Based on the present invention, valid network prefixes are saved in the access node device in the IPv6 access network, a network prefix in a source IPv6 address of a packet from the CPN is checked, and if it is found that the network prefix in the source IPv6 address of the packet belongs to the saved valid network prefixes, the access node device then forwards the packet. Since only the network prefix portion in IPv6 addresses is subjected to a check, a small quantity of valid network prefix information is saved in the access node device, which avoids a large storage space required for directly saving a large amount of valid IPv6 addresses. Preferably, the access node device can automatically obtain those valid network prefixes corresponding to the CPN by snooping network prefix allocation messages sent to the Residential Gateway.
[0008] According to a first aspect of the present invention, there is provided a method for forwarding a packet from a Residential Gateway in an access node device in an IPv6 access network. The access node device first receives a packet from the Residential Gateway, then obtains a network prefix in a source IPv6 address of the packet, judges whether the network prefix in the source IPv6 address of the packet is a valid network prefix of a CPN corresponding to the Residential Gateway, and if yes, forwards the packet finally.
[0009] According to a second aspect of the present invention, there is provided an apparatus for forwarding a packet from a Residential Gateway in an access node device in an IPv6 access network. The apparatus comprises a receiving unit for receiving a packet from the Residential Gateway, an obtaining unit for obtaining a network prefix in a source IPv6 address of the packet, a judgment unit for judging whether the network prefix in the source IPv6 address of the packet is a valid network prefix of a CPN corresponding to the Residential Gateway, and a forwarding unit for forwarding the packet finally.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other objects, features, and advantages of the present invention will become more apparent from the description of the non-limiting embodiments, when taken in conjunction with the figures wherein,
[0011] FIG. 1 illustrates a schematic topological structural view of an IPv6 access network according to a specific embodiment of the present invention;
[0012] FIG. 2 illustrates a message flow view of a method for forwarding a packet in an access node device in an IPv6 access network according to a specific embodiment of the present invention;
[0013] FIG. 3 illustrates a block diagram of an apparatus for forwarding a packet in an access node device in an IPv6 access network according to another specific embodiment of the present invention;
[0014] FIG. 4 illustrates a message flow view of a method for forwarding a packet in an access node device in an IPv6 access network according to another specific embodiment of the present invention;
[0015] FIG. 5 a illustrates a schematic structural view of IA_PD options in the DHCPv6 protocol; and
[0016] FIG. 5 b illustrates a schematic structural view of Iaprefix-options in the DHCPv6 protocol.
[0017] Like or similar reference numerals denote the same or similar step features or devices (modules) throughout the figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] In a schematic topological layout view of an IPv6 access network according to a specific embodiment of the present invention as illustrated in FIG. 1 , a Network Access Provider (NAP) is connected via an access node device with one or more Residential Gateways (RGWs) 31 . Each RGW 31 is connected with a Customer Premises Network (CPN). User Terminals In (n is a natural number equaling 1, 2, . . . ) is connected with the RGW 31 to obtain a network prefix or an IPv6 address from the RGW 31 and send a packet that contains the IPv6 address of the User Terminal as a source IP address, to the NAP via the RGW 31 . The NAP is connected with a network of one or more Network Service Providers (NSPs) via a network device such as an edge router, wherein the network device includes a Dynamic Host Configuration Protocol (DHCPv6) server, an Authentication, Authorization and Accounting (AAA) server, etc.
[0019] FIG. 2 illustrates a message flow view of a method for forwarding a packet in an access node device in an IPv6 access network according to a specific embodiment of the present invention. Hereinafter, the specific embodiment of the present invention as illustrated in FIG. 2 will be explained in detail in conjunction with FIG. 1 .
[0020] First of all, an access node device 41 receives a packet from the RGW 31 in step S 21 . The packet contains a source IPv6 address.
[0021] Optionally, varieties of communication techniques may be used for packet transmission between the access node device 41 and the Residential Gateway 31 , such as the Digital Subscriber Line (DSL) technique, an optical fiber connection, a cable connection, or wireless transmission techniques including IEEE 802.16.
[0022] Next, the access node device 41 obtains a network prefix in the corresponding source IPv6 address from the received packet in step S 22 .
[0023] Then, in step S 23 , the access node device 41 judges whether the network prefix in the source IPv6 address of the packet is a valid network prefix of the CPN corresponding to the RGW 31 . In the IPv6 network, IPv6 addresses used by all User Terminals within a CPN typically belong to one or more address spaces. That is, usually the same CPN is allocated one or more IPv6 address spaces, i.e., correspond to one or more network prefixes.
[0024] Optionally, these network prefixes may be allocated to the CPN by a network prefix allocation server (e.g., a DHCPv6 server), or they may be configured or specified by other configuration servers during network deployment in advance. During actual implementation of the present invention, after the CPN obtains the above valid network prefixes, these valid network prefixes may be reported by the RGW 31 to the access node device 41 connected with the RGW 31 , or the access node device 41 may obtain these valid network prefixes by snooping a relevant message sent by the network prefix allocation server or the configuration server to the RGW.
[0025] Hence, when the access node device 41 obtains the valid network prefixes of the CPN corresponding to the RGW 31 , it is possible to check whether the network prefix in the source IPv6 address of the packet sent via the RGW 31 from the User Terminal within the CPN is one of these valid network prefixes.
[0026] Preferably, the access node network 41 prestores the valid network prefixes corresponding to the CPN in the form of a set, i.e., the access node network 41 prestores a valid network prefix set for the CPN. In this manner, it is simply to judge in step S 23 whether the network prefix in the source IPv6 address obtained from the packet belongs to the valid network prefix set prestored for the CPN by the access node device 41 .
[0027] More preferably, for each set element or part of set elements of the valid network prefix set saved for the CPN by the access node device 41 , i.e., for each valid network prefix or part of valid network prefixes, valid lifetime information is saved to indicate during which time period the IPv6 address space represented by the valid network prefix is used by the corresponding CPN. Generally valid lifetime information of a valid network prefix may be expressed in the following forms:
[0028] 1) Specifying a Start Time and a Length of Time
[0029] For example, if the start time of valid lifetime information of the valid network prefix 3FFE:FFFF:0:C000::/54 is 20:00 on Aug. 8, 2008 and the length of time is 2000 seconds, it indicates that the valid network prefix is valid within 2000 seconds starting from 20:00 on Aug. 8, 2008, i.e., the User Terminal within the CPN may use the IPv6 address in the address space represented by the valid network prefix to send packets. At this point, the valid network prefix in the valid network prefix set may be expressed as (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 8, 2008, 2000 seconds). Table 1 shows a set of valid network prefixes having valid lifetime information expressed in the above form, wherein the set comprises three valid network prefixes and respective valid lifetime information.
[0000]
TABLE 1
Length
Serial Number
Network Prefix
Start Time
of Time
valid network
3FFE:FFFF:0:C000::/54
20:00 on
2000
prefix 1
August 8, 2008
seconds
valid network
3FFE:EEEE:0:C000::/54
20:00 on
200000
prefix 2
July 8, 2008
seconds
valid network
3FFE:DDDD:0:C000::/54
20:00 on
300000
prefix 3
June 8, 2008
seconds
[0030] 2) Specifying a Deadline
[0031] For example, if the deadline of valid lifetime information of the valid network prefix 3FFE:FFFF:0:C000::/54 is 20:00 on Aug. 24, 2008, it indicates that this valid network prefix is valid by 20:00 on Aug. 24, 2008, i.e., the User Terminal within the CPN may use the IPv6 address in the address space represented by the valid network prefix to send packets. At this point, the valid network prefix in the valid network prefix set may be expressed as (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 24, 2008). Table 2 shows a set of valid network prefixes having valid lifetime information expressed in the above form, wherein the set comprises two valid network prefixes and respective valid lifetime information.
[0000]
TABLE 2
Serial Number
Network Prefix
Deadline
valid network prefix 1
3FFE:FFFF:0:C000::/54
20:00 on
August 24, 2008
valid network prefix 2
3FFE:EEEE:0:C000::/54
20:00 on
August 24, 2008
[0032] As a preferred embodiment of the present invention, in the case that the valid network prefix set saved for the CPN by the access node device 41 further saves valid lifetime information of each prefix network prefix, the access node device 41 further judges whether each valid network prefix in the valid network prefix set has expired, according to valid lifetime information corresponding to each valid network prefix; if a certain valid network prefix has expired, the access node device 41 then deletes it from the valid network prefix set. For example, a valid network prefix in the valid network prefix set as shown in Table 2 is (3FFE:EEEE:0:C000::/54, 20:00 on Aug. 24, 2008). If the current system time is 20:05 on Aug. 24, 2008, it means that this valid network prefix has expired, i.e., the User Terminal within the CPN should not use the IPv6 address in the address space represented by this valid network prefix to send packets any more. At this point, the access node device 41 then deletes the valid network prefix (3FFE:EEEE:0:C000::/54, 20:00 on Aug. 24, 2008) from the valid network prefix set. Accordingly, after this valid network prefix is deleted, the valid network prefix set in Table 2 may be as shown in Table 3.
[0000]
TABLE 3
Serial Number
Network Prefix
Deadline
valid network prefix 1
3FFE:EEEE:0:C000::/54
20:00 on
September 8, 2008
[0033] Optionally, during actual implementation of the present invention, whether a valid network prefix has expired may be judged by periodically scanning each valid network prefix in the valid network prefix set and based on the corresponding valid lifetime information and the current system time; if a certain valid network prefix has expired, it is deleted from the valid network prefix set. Preferably, a corresponding timer may be initiated according to valid lifetime information corresponding to a valid network prefix; in the case of a timer timeout event, the corresponding valid network prefix is deleted from the valid network prefix set.
[0034] If a certain valid network prefix in the valid network prefix set has no corresponding valid lifetime information being saved, it is then believed that this valid network prefix is allocated to the CPN corresponding to the RGW 31 for use all along, i.e., this valid network prefix will not expire as time elapses.
[0035] Preferably, the RGW 31 corresponding to the CPN requests a valid network prefix of the CPN from the network prefix allocation server (e.g., the DHCPv6 server or other AAA server). Hence, the network prefix allocation server usually sends a network prefix allocation reply message to the RGW 31 . According to the topological structure of an IPv6 access network as illustrated in FIG. 1 , these network prefix allocation reply messages must pass through the access node device 41 before reaching the RGW 31 , so that the access node device 41 can conveniently, duly and efficiently snoop these network prefix allocation reply messages, obtain valid network prefixes allocated to the CPN and add them to a valid network prefix set saved for this CPN (at this point, if the access node device 41 contains no corresponding valid network prefix set, it first creates an empty valid network prefix set before performing the adding operation). When the access node device 41 obtains, from the snooped network prefix allocation reply message, a valid network prefix allocated to the CPN along with valid lifetime information corresponding to the valid network prefix, then the access node device 41 adds the valid network prefix and its corresponding lifetime information to the valid network prefix set. For example, if the allocated valid network prefix is 3FFE:FFFF:0:C000::/54 and valid lifetime information represented by a deadline is 20:00 on Aug. 24, 2008, then (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 24, 2008) may be jointly added to the valid network prefix set of the CPN corresponding to the RGW 31 . Specifically,
[0036] 1) if the valid network prefix set already contains a valid network prefix (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 21, 2008), then the valid lifetime information 20:00 on Aug. 21, 2008 corresponding to the valid network prefix is updated as 20:00 on Aug. 24, 2008, or (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 21, 2008) are deleted from the valid network prefix set and then (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 24, 2008) are added to the set.
[0037] 2) if the valid network prefix set already contains a valid network prefix 3FFE:FFFF:0:C000::/54 without corresponding valid lifetime information, then 20:00 on Aug. 24, 2008 is used as valid lifetime information of the valid network prefix, i.e., the updated valid network prefix set includes the member (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 24, 2008);
[0038] 3) in other cases, i.e., if the valid network prefix set does not contain the network prefix 3FFE:FFFF:0:C000::/54, (3FFE:FFFF:0:C000::/54, 20:00 on Aug. 24, 2008) are then added to the valid network prefix set as a new member.
[0039] Preferably, the above-mentioned network prefix allocation server comprises a DHCPv6 server or a Delegating Router, and the network prefix reply message sent to the RGW 31 comprises a DHCP Reply message for Prefix Delegation or a DHCP Reconfigure message for Prefix Delegation.
[0040] Preferably, during actual implementation of the present invention, the access node device 41 is usually connected with a plurality of different Residential Gateways. At this point, in order to easily differentiate a Residential Gateway to which the snooped DHCP Reply message or DHCP Reconfigure message will be sent, the access node device 41 further comprises the following steps:
[0041] First, the access node device 41 inserts a logical identifier, which is used by a local access device for identifying a Residential Gateway, into an upstream DHCP message (in the present application document, a DHCP message which is sent by the RGW 31 via the access node device 41 to the DHCPV6 server is referred to as an “upstream DHCP message” and a DHCP message which is sent by the DHCPv6 server via the access node device 41 to the RGW 31 is referred to as a “downstream DHCP message”) received from the Residential Gateway and then forwards the upstream DHCP message;
[0042] Second, upon receipt of a downstream DHCP message from the DHCPv6 server or the Delegating Router, the access node device 41 judges, according to the logical identifier used by the local access node device for identifying the Residential Gateway as contained therein, whether the downstream DHCP message is sent to the Residential Gateway corresponding to the contained logical identifier, and forwards the downstream DHCP message to the Residential Gateway. Different logical identifiers correspond to different Residential Gateways with which the access node device 41 is connected.
[0043] Specifically, the upstream DHCP message comprises a DHCP Solicit message, a DHCP Request message, a DHCP Renew message, a DHCP Rebuild message and the like in the DHCPv6 protocol; the downstream message comprises a DHCP Advertise message for Prefix Delegation, a DHCP Reply message for Prefix Delegation, and a DHCP Reconfigure message for Prefix Delegation.
[0044] Preferably, if the access node device 41 and the RGW 31 are connected via a Digital Subscriber Line, the access node device 41 typically uses a unique DSL line number to represent this Digital Subscriber Line. At this point, the DSL line number may be selected as a logical identifier used for identifying the Residential Gateway by the local access node device during actual implementation of the present invention.
[0045] Lastly, if the access node device 41 determines in step S 23 that the network prefix in the source IP address of the packet is one of valid network prefixes of the CPN or belongs to the valid network prefix set of the CPN, then the access node device 41 forwards the packet in step S 24 .
[0046] It should be noted that the above-described updates on the valid network prefix set, such as deletion and addition, may be implemented while the access node device checks and forwards the network prefix in the source IPv6 address of the packet. That is, there is no strict requirement on the time sequence between the updates on the valid network prefix set, such as deletion and addition, and steps S 21 -S 23 .
[0047] FIG. 3 illustrates a block diagram of an apparatus for forwarding a packet in an access node device in an IPv6 network according to another specific embodiment of the present invention. Hereinafter, the specific embodiment of the present invention as illustrated in FIG. 3 will be explained in detail in conjunction with FIG. 1 .
[0048] In the access node device 41 , the apparatus for forwarding a packet comprises a receiving unit 410 , an obtaining unit 411 , a judgment unit 412 , a forwarding unit 413 , a deletion unit 414 , and a snooping unit 415 . For the purpose of conciseness, the apparatus for forwarding a packet comprises many sub-means contained in the preferred embodiments. Under the teaching of the present application, those skilled in the art would appreciate that only the receiving unit 410 , the obtaining unit 411 , the judgment unit 412 , and the forwarding unit 413 are essential to implementation of the present invention and that other means may be optical means.
[0049] First of all, the access node device 41 receives a packet from the RGW 31 by means of the receiving unit 410 , wherein the packet comprises a source IPv6 address.
[0050] Next, the access node device 41 obtains a network prefix in the corresponding source IPv6 address from the received packet by means of the obtaining unit 411 .
[0051] Then, the access node device 41 judges, by means of the judging unit 412 , whether the network prefix in the source IPv6 address of the packet is one of valid network prefixes of the CPN corresponding to the RGW 31 . The judgment unit 412 saves all valid network prefixes of the CPN corresponding to the RGW 31 , i.e., network prefixes allocated to the CPN. In other words, the User Terminals within the CPN may use IPv6 addresses of IPv6 spaces represented by these network prefixes to send packets.
[0052] Preferably, the judgment unit 412 prestores valid network prefixes corresponding to CPN in the form of a set, i.e., prestores a valid network prefix set of the CPN. In this way, it is possible for the judgment unit 412 to simply judge whether the network prefix in the source IPv6 address obtained from the packet belongs to the prestored valid network prefix set of the CPN.
[0053] More preferably, for each set element or part of set elements of the valid network prefix set of the CPN as saved by the judgment unit 412 , i.e., for each valid network prefix or part of valid network prefixes, valid lifetime information is saved to indicate during which time period the IPv6 address space represented by the valid network prefix is used by the corresponding CPN. At this point, the deletion unit 414 judges whether each valid network prefix in the valid network prefix set has expired, according to valid lifetime information corresponding to each valid network prefix; if a certain valid network prefix has expired, the deletion unit 414 then deletes it from the valid network prefix set.
[0054] Optionally, during actual implementation of the deletion unit 414 , whether a valid network prefix has expired may be judged by periodically scanning each valid network prefix in the valid network prefix set and based on the corresponding valid lifetime information and the current system time; if a certain valid network prefix has expired, it is deleted from the valid network prefix set. Preferably, a corresponding timer may be initiated according to valid lifetime information corresponding to a valid network prefix; in the case of a timer timeout event, the deletion unit 414 deletes the corresponding valid network prefix from the valid network prefix set.
[0055] Preferably, the RGW 31 corresponding to the CPN requests a valid network prefix of the CPN from the network prefix allocation server (e.g., the DHCPv6 server or other AAA server). Hence, the network prefix allocation server usually sends a network prefix allocation reply message to the RGW 31 . At this point, the snooping unit 415 may conveniently, duly and efficiently snoop these network prefix allocation reply messages, obtain valid network prefixes allocated to the CPN and add them to a valid network prefix set corresponding to the CPN as saved by the judgment unit 413 (at this point, if the judgment unit 413 contains no corresponding valid network prefix set, it first creates an empty valid network prefix set before performing the adding operation).
[0056] When a network prefix allocation reply message contains both a valid network prefix allocated to the CPN and the corresponding valid lifetime information, the snooping unit 415 then obtains the valid network prefix allocated to the CPN along with the corresponding valid lifetime information by snooping the network prefix allocation reply message, and adds the valid network prefix and its corresponding valid lifetime information to the valid network prefix set saved by the judgment unit 413 .
[0057] Similarly, the snooping unit 415 may perform an adding operation to the valid network prefix set corresponding to the CPN as saved by the judgment unit 413 by using the method described above.
[0058] Preferably, the snooping unit 415 obtains the valid network prefix allocated to the CPN and the corresponding valid lifetime information by snooping a DHCP Reply message for Prefix Delegation or a DHCP Reconfigure message for Prefix Delegation which is sent by the DHCPv6 server or the Delegating Router to the RGW 31 .
[0059] Preferably, during actual implementation of the present invention, the access node device 41 is usually connected with a plurality of different Residential Gateways. At this point, in order to easily differentiate a Residential Gateway to which the snooped DHCP Reply message or DHCP Reconfigure message will be sent, the snooping unit 415 is further for the following use:
[0060] First, the snooping unit 415 inserts a logical identifier, which is used by a local access device for identifying a Residential Gateway, into an upstream DHCP message received from the Residential Gateway and then forwards the upstream DHCP message;
[0061] Second, upon receipt of a downstream DHCP message from the DHCPv6 server or the Delegating Router, the snooping unit 415 judges, according to the logical identifier used by the local access node device for identifying the Residential Gateway as contained therein, whether the downstream DHCP message is sent to the Residential Gateway corresponding to the contained logical identifier, and forwards the downstream DHCP message to the Residential Gateway.
[0062] Specifically, the upstream DHCP message comprises a DHCP Solicit message, a DHCP Request message, a DHCP Renew message, a DHCP Rebuild message and the like in the DHCPv6 protocol; the downstream message comprises a DHCP Advertise message for Prefix Delegation, a DHCP Reply message for Prefix Delegation, and a DHCP Reconfigure message for Prefix Delegation.
[0063] Preferably, if the access node device 41 and the RGW 31 are connected via a Digital Subscriber Line, the access node device 41 typically uses a unique DSL line number to represent this Digital Subscriber Line. At this point, the DSL line number may be selected as a logical identifier used for identifying the Residential Gateway by the local access node device during actual implementation of the present invention.
[0064] Lastly, if the judgment unit 413 determines that the network prefix in the source IP address of the packet is one of valid network prefixes of the CPN or belongs to the valid network prefix set of the CPN as prestored by the access node device 41 , then the packet is forwarded by means of the forwarding unit 414 .
[0065] FIG. 4 illustrates a message flow view of a method for forwarding a packet in an access node device in an IPv6 network according to another specific embodiment of the present invention. Hereinafter, the specific embodiment of the present invention as illustrated in FIG. 4 will be explained in detail in conjunction with FIGS. 1 , 5 a , and 5 b.
[0066] In the IPv6 access network according to this embodiment, the access node device 41 is connected with different Residential Gateways via different Digital Subscriber Lines; in the access node device 41 , different Digital Subscriber Lines are uniquely represented by different DSL line numbers (DSL line No.) and are connected with different Residential Gateways. In the meanwhile, the RGW 31 corresponds to a CPN where the User Terminals send packets to the access node device 41 via the Residential Gateway.
[0067] After being connected with the access node device 41 , the RGW 31 first sends a DHCP Solicit message to the DHCPv6 server in step S 31 , requesting the DHCPv6 server to allocate it a corresponding network prefix. The DHCP Solicit message contains IA_PD-option information as illustrated in FIG. 5 a.
[0068] Upon receipt of the DHCP Solicit message sent by the RGW 31 , the access node device 41 adds the DSL line number of the Digital Subscriber Line, which connects the access node device 41 with the RGW 31 , to the DHCP Solicit message by means of the Relay Agent Subscriber ID option defined in the DHCPv6 protocol and subsequently forwards the DHCP Solicit message to the DHCPv6 server, in step S 32 . It should be noted that this DSL line number may be replaced by a logical identifier used for differentiating a Residential Gateway by the access node device 41 , wherein the access node device 41 differentiates different Residential Gateways, which are connected therewith, according to different logical identifiers. For example, optionally, when the access node device 41 uses different serial numbers to uniquely denote different Residential Gateways connected therewith, the above DSL line number may be replaced by a serial number denoting the RGW 31 .
[0069] Upon receipt of a DHCP Advertise message sent by the DHCPv6 server, the access node device 41 removes the contained DSL line number from the message in step S 33 and forwards the DHCP Advertise message, which no longer contains the DSL line number, to the Residential Gateway corresponding to the DSL line number in step S 34 .
[0070] Similarly, the access node device 41 receives a DHCP Request message sent by the RGW 31 in step S 35 , wherein the DHCP Request message contains IA_PD-option as illustrated in FIG. 5 a , and the IA_PD option contains Iaprefix-option information as illustrated in FIG. 5 b . Subsequently, the access node device 41 adds the DSL line number of the Digital Subscriber Line, which connects the access node device 41 with the RGW 31 , to the DHCP Request message by means of the Relay Agent Subscriber ID option defined in the DHCPv6 protocol and forwards the DHCP Request message to the DHCPv6 server, in step S 36 .
[0071] Upon receipt of a DHCP Reply message for Delegation sent by the DHCPv6 server, the access node device 41 removes the contained DSL line number from the message in step S 37 and forwards the DHCP Reply message for Delegation, which no longer contains the DSL line number, to the Residential Gateway 31 corresponding to the DSL line number in step S 38 . The DHCP Reply message for Delegation contains the Iaprefix-option information as illustrated in FIG. 5 b , an IPv6 prefix contained in the Iaprefix-option is a network prefix allocated to the RGW 31 by the DHCPv6 server, and corresponding valid lifetime information represented by the network prefix is that the time when the RGW 31 receives the DHCP Reply message for Delegation is a start time and the valid-lifetime contained in the Iaprefix-option is a length of time.
[0072] With steps S 31 to S 38 , the access node deice 41 can obtain the valid network prefix allocated to the RGW 31 by the DHCPv6 server and the corresponding valid lifetime information from the snooped DHCP Reply message for Delegation. For example, if the access node device 41 receives a DHCP Reply message for Delegation sent by the DHCPv6 server to the RGW 31 , at 20:00 on Sep. 9, 2008, wherein the contained IPv6 prefix is 3FFE:FFFF:0:C000::/54, the contained valid-lifetime is 2000 seconds, and the access node device 41 saves no valid network prefix set for a CPN corresponding to the RGW 31 , then the access node device 41 will create a list as shown in Table 4 to save the valid network prefix 3FFE:FFFF:0:C000::/54 allocated to the CPN and the corresponding valid lifetime information.
[0000]
TABLE 4
Length
Serial Number
Network Prefix
Start Time
of Time
network
3FFE:FFFF:0:C000::/54
20:00 on
2000
prefix 1
September 9, 2008
seconds
[0073] Afterwards in step S 39 , a User terminal within the CPN obtains the valid network prefix information from the RGW 31 by means of the IPv6 address stateless auto-configuration mechanism and forms an available IPv6 address using the valid network prefix information in conjunction with its own device information. In step S 40 , the User Terminal sends a packet to the RGW 31 by using the newly formed IPv6 address as a source IP address of the packet. The RGW 31 then forwards the packet to the access node device 41 in step S 41 . For example, if a network prefix allocated to the RGW 31 is 3FFE:FFFF:0:C000::/54, a possible IPv6 address formed by the User Terminal is 3FFE:FFFF:0:C000:1111:2222:AAAA:BBBB. Then, the access node device 41 obtains in step S 42 the network prefix 3FFE:FFFF:0:C000::/54 from the source IPv6 address of the packet from the User Terminal as forwarded by the RGW 31 , compares in step S 43 this network prefix with the valid network prefix set of the CPN corresponding to the RGW 31 as shown in Table 4 to determine whether the network prefix belongs to the valid network prefix set as shown in Table 4, and finally forwards the packet to the NSP network or other device within the access network in step S 44 .
[0074] The specific embodiments of the present invention have been described above. It is to be understood that the present invention is not limited to the foregoing specific embodiment, and that those of ordinary skill in the art may make various variations or modifications within the scope of the appended claims. The technical solution of the present invention may be implemented in software or hardware.
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In view of the technical problems that exist during implementing IP address anti-spoofing in an access node device in an IPv6 access network, the present invention proposes a packet forwarding method and apparatus in an IPv6 Access Node, for forwarding a packet from a Residential Gateway. In the method, the access node device first receives a packet from the Residential Gateway, then obtains a network prefix in a source UPv6 address of the packet, judges whether the network prefix in the source IPv6 address of the packet is a valid network prefix of a CPN corresponding to the Residential Gateway, and if yes, forwards the packet finally. Particularly, in the present invention the access node device can automatically obtain valid network prefix using technical means such as snooping a network prefix allocation reply message. Therefore, the present invention greatly increases operation efficiency and security of the IPv6 access network and simplifies network management of the IPv6 access network.
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This application is a Continuation-in-Part of U.S. application Ser. No. 09/045,212, filed Mar. 20, 1998 now U.S. Pat. No. 6,146,007, the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates generally to asphalt plants. More specifically, the present invention relates to an asphalt plant which captures and mitigates fugitive emissions and which uses a centralized media burner to supply process heat energy to the various plant components.
BACKGROUND OF THE INVENTION
On asphalt plants it is desirable to have a variety of air pollution control measures. The asphalt making process, by its very nature of heating and processing the bituminous asphalt components, produces a considerable quantity of undesirable hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), particulate matter and other emissions which constitute the unfortunate signature plume of an asphalt plant, commonly referred to as “blue smoke.” In addition to being a source of air pollution, asphalt plants are noisy and visually unappealing, owing to their network of open conveyors, hoppers, bins, blowers and other heating and material handling equipment. Accordingly, asphalt plants in general are regarded as quite a nuisance, especially in and around residential areas.
The typical asphalt plant has high energy requirements. The drum dryer/mixer typically includes a gas burner to dry the aggregate material and to heat the mixing zone to foster adequate mixing of the aggregate with the liquid asphalt. The asphalt material contained in the asphalt storage tanks must be constantly heated to maintain the asphalt cement in its liquid state, and thus another gas burner or similar heating system is required in order to constantly heat the storage tanks. Thus, burner emission are created at both the asphalt storage tanks and at the drum dryer/mixer.
Moreover, the volatile components of the heated asphalt cement as well as the finished asphalt create a certain amount of fugitive emissions as the asphalt components and the finished asphalt are stored, mixed, and transported through the plant. Furthermore, the asphalt cement storage tanks and the asphalt storage silos are usually vented in order to prevent undue pressure build up, especially on hot days, which further complicates the fugitive emission problem. Additional fugitive emissions are created when the finished asphalt material is loaded onto trucks for transport to a job site.
One approach to alleviating the fugitive emission problem has been to enclose portions or all of the plant in order to minimize the amount of leakage from the ductwork and conveyors in the plant. Such an approach, an example of which is described more fully in U.S. Pat. No. 5,620,249, does not provide an improved mitigation system and is typically best suited for applications in which the plant can be made very compact, which is not always feasible.
Attempts have also been made to apply flameless media burner technology to asphalt plants. Media burner technology uses a bed or matrix of ceramic materials which act as a flame arrestor, thereby controlling the rate and temperature of the combustion process. Externally mixed fuel is added to the media burner, which is pre-heated until a self-sustaining combustion is initiated. Ideally, a very efficient centralized media burner should be able to supply heat to the various process components, so that the maximum amount of energy is extracted from the consumed fuel. Unfortunately, existing media burner technology has proven unsatisfactory for asphalt processing plants. The externally mixed fuel components have proven to be too explosive for safe, everyday applications.
Accordingly, there exists a continuing need for an improved asphalt plants.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, an asphalt plant includes a plurality of asphalt processing components, with the plurality of processing components including a first set of components producing volatile emission and a second set of components requiring process heat. A central burner assembly is disposed separately from each of the plurality of processing components, with the central burner assembly being adapted to supply heat energy in the form of heated gas to satisfy the process heat requirements of the second component set. A first duct system is in flow communication with the first component set and the central burner assembly, with the first duct system including a fan and being adapted to capture a portion of the volatile emissions produced by the first component set and to convey the captured emissions into the central burner assembly for mitigation. A second duct system is in flow communication with each of the components in the second component set and the central burner assembly, with the second duct system including a fan and being adapted to convey heated gas from the central burner assembly to the second component set.
In further accordance with a preferred embodiment, the first set of components may include an asphalt cement storage tank, an asphalt storage silo, a drum dryer/mixer having a mixing zone, and/or a truck loading area having a substantially sealed enclosure. At least one component of the first set of components may include an enclosure connected to the first duct system.
The central burner assembly may include an air inlet plenum, with the first duct system being connected to the air inlet plenum. Further, the second component set may include a rotary drum dryer/mixer, and the second duct system may include an insulated portion for conveying heat to the drum dryer/mixer. The asphalt plant may include a cement storage tank, with each of the storage tank and the central burner assembly including a heat exchange unit, with the heat exchange units being adapted to scavenge heat from the central burner assembly and convey the heat to the storage tank.
Preferably, the central burner assembly comprises a media burner having an enclosed combustion chamber defined in part by a top wall, a bottom wall, and an interconnecting sidewall. A portion of the combustion chamber preferably contains a matrix of ceramic members. The media burner preferably includes a fuel delivery system, with the internal delivery system being adjustable to permit the fuel to be injected at different locations within the media burner.
Still preferably, the first duct system may be connected to an air plenum for delivering captured fugitive emissions to the media burner, and an air valve may be provided for controlling the flow of air from the air plenum to the combustion chamber. The air valve may include a baffle slidably mounted adjacent an air inlet opening in the bottom wall, with the baffle being moveable between an open position removed from the air inlet opening and a closed position covering the air inlet opening.
In accordance with another aspect of the invention, a central media burner is provided for providing process heat in the form of heated gas to a selected set of asphalt processing components, with the central media burner being separate from each of the processing components. The central media burner comprises an enclosed combustion chamber defined in part by a top wall, a bottom wall, and an interconnecting sidewall. A portion of the combustion chamber contains a matrix of ceramic members, with at least one of the walls defining a gas outlet. The combustion chamber is adapted to supply thermal energy in the form of heated gas. An adjustable internal fuel delivery system delivers fuel to a selected location in the combustion chamber portion, and an air inlet plenum delivers combustion air to the combustion chamber. A duct system communicates the heated gas from the gas outlet to the selected set of processing components, whereby the heated gas is supplied through the duct system to each of the processing components to satisfy the process heat requirements thereof.
In accordance with yet another aspect of the invention, an asphalt plant comprises a plurality of asphalt processing components, with a first set of components producing volatile emissions, and a second set of components requiring process heat energy. A central media burner produces process heat energy in the form of heated gases, with the media burner having an enclosed combustion chamber defined in part by a top wall, a bottom wall, and an interconnecting sidewall, with a portion of the combustion chamber containing a matrix of flame arresting ceramic members. The central media burner, which is separate from each of the plurality of asphalt processing components, also includes an inlet and an outlet. A fuel delivery system is provided to deliver combustion fuel directly to the combustion chamber. A first duct system including a fan is in flow communication with the first component set and the central media burner inlet, and captures a portion of the volatile emissions produced by the first component set and conveys the captured emissions to the inlet of the central media burner for mitigation. A second duct system includes a fan and is in flow communication with the second component set and the central media burner outlet, and conveys heat energy from the outlet of the central media burner to the second component set.
In accordance with a still further aspect of the invention, an asphalt plant comprises a drum dryer/mixer requiring heat energy and producing volatile emissions, a flameless media burner assembly, a first duct system and a second duct system. The media burner assembly is remote from the drum dryer/mixer, with the media burner assembly having an enclosed combustion chamber and a fuel delivery system extending into the combustion chamber. A portion of the combustion chamber houses a matrix of ceramic members, and the fuel delivery system has a fuel port to convey fuel to the combustion chamber portion. The first duct system is in flow communication with the drum dryer/mixer and the media burner assembly, with the first duct system including a fan and being adapted to capture a portion of the volatile emissions produced by the drum dryer/mixer and to convey the captured emissions into the media burner assembly for mitigation. The second duct system is in flow communication with the drum dryer/mixer and the media burner assembly, with the second duct system including a fan and being adapted to convey heat energy in the form of heated gas from the media burner assembly to the drum dryer/mixer.
In accordance with yet another aspect of the invention, an asphalt plant comprises an asphalt processing component that produces volatile emissions and that requires process heat, a flameless burner assembly, and a first and second duct system. The flameless burner assembly supplies heat energy to the processing component, with the flameless burner assembly being separate and spaced apart from the processing component. The first duct system is in flow communication with the processing component and the flameless burner assembly and captures at least a portion of the volatile emissions produced by the processing component and conveys the captured emissions into the flameless burner for mitigation. The second duct system is in communication with the processing component and the flameless burner assembly, and supplies heat energy from the flameless burner assembly to the second component set to thereby substantially satisfy the process heat requirements thereof.
These and other objects, features and advantages of the present invention will become readily apparent to those skilled in the art upon a reading of the following description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan diagrammatic view of an asphalt plant incorporating the features of the present invention;
FIG. 2 is a fragmentary elevational view of the drum dryer/mixer and the baghouse filter illustrating the insulated duct from the media burner routed into the mixing zone of the drum dryer/mixer;
FIG. 3 is an enlarged elevational view in cross-section of the media burner having the internal add fuel injection system;
FIG. 4 is an enlarged fragmentary elevational view of the media burner internal fuel injection system;
FIG. 5 is an enlarged fragmentary elevational view taken along lines 5 — 5 of FIG. 4; and
FIG. 6 is an enlarged fragmentary plan view taken along lines 6 — 6 of FIG. 5 illustrating the air valve assembly.
DETAILED DESCRIPTION
The following detailed description is not intended to limit the invention to the precise form or forms disclosed. The embodiments described in detail have been chosen in order to best explain the principles of the invention so that others skilled in the art may follow its teachings.
Referring now to the drawings, FIGS. 1 and 2 illustrate an asphalt plant incorporating features of the present invention and generally referred to by the reference numeral 10 . The asphalt plant typically includes a variety of plant processing components, such as those components outlined in more detail in U.S. Pat. No. 5,620,249, the disclosure of which is incorporated herein by reference. Asphalt plant 10 typically includes a rotating drum dryer/mixer 12 . The drum dryer/mixer 12 is preferably of the counterflow design, although a parallel flow drunk dryer/mixer could also be used. Asphalt plant 10 also typically includes a plurality of virgin aggregate silos 14 , a recycled asphalt product (RAP) storage bin 16 , and a virgin aggregate hopper 18 . A conveyor 20 is provided to transport the virgin aggregate to the drum dryer/mixer 12 , while a RAP conveyor 22 is provided to transport the RAP to the drum dryer/mixer 12 . The conveyors 20 , 22 may be slat conveyors or other conventional designs. Each conveyor 20 , 22 is preferably enclosed by a duct 24 , 26 , respectively. One or more asphalt cement storage tanks 28 are provided which supply liquid asphalt to the drum dryer/mixer 12 via a feed line 30 as is well known in the art.
Finished hot mix asphalt produced in the drum dryer/mixer 12 is conveyed to a batcher silo 32 by a bucket conveyor 34 , from where the asphalt is transferred to one or more loadout silos 36 by a conveyor 38 . The bucket conveyor 34 and the conveyor 38 are each enclosed by a duct 40 , 42 , respectively. The loadout silos are preferably mounted over an enclosure 44 sized to receive a transport vehicle (not shown). Each of the drum dryer/mixer 12 , the conveyors 20 22 [ 22 , 24 ], 34 , 38 , and the silos 32 and 36 are likely to release volatile emissions, which are captured by a portion of the duct systems 24 , 26 , 40 , 42 and the enclosure 44 . The captured emissions are routed to a return duct 46 , and then to a central burner 48 as outlined below. Another return duct 47 is provided which routes captured emissions from the storage tanks 28 to the central burner 48 as will be discussed in greater detail below.
The central burner 48 is preferably a media burner employing flameless combustion technology. A more complete explanation of flameless combustion technology can be found in U.S. Pat. No. 5,165,884, the disclosure of which is incorporated herein by reference. The return duct 46 is connected to the burner 48 for routing the captured emissions within the duct 46 to the burner 48 for mitigation as will be explained in greater detail below. Burner 48 includes an insulated duct 50 which routes heat energy to the drum dryer/mixer 12 . Additional heat energy may be routed to other components as needed using additional ducts (not shown). Each of the above mentioned ducts preferably is insulated and includes one or more dampers for closing portions of the ducts during plant start up or as may otherwise be required.
As shown in FIG. 2, a filter or baghouse 52 is provided for capturing particulate emission from the drum dryer/mixer 12 in a manner well known in the art. An insulated duct 54 routes the exiting gas stream from the drum dryer/mixer 12 to the baghouse 52 , and duct 54 is also connected to return duct 46 for routing emissions to the burner 48 . The heat energy from the drum dryer/mixer 12 , which has been routed through the insulated duct 50 , enters the interior of the drum dryer/mixer 12 at an exit point 56 .
Also as shown in FIG. 2, the drum dryer/mixer 12 preferably includes a collar 58 for introducing RAP into the drum dryer/mixer 12 , a discharge hood 60 for routing finished hot mix asphalt out of the drum dryer/mixer 12 , and an insulated duct 62 having a damper 64 that connects the drum dryer/mixer 12 to the stack 66 of the baghouse 54 . A fan 68 in conjunction with a damper 70 controls the flow of gases from the mixing zone 73 of the drum dryer/mixer 12 to the insulated duct 50 via an insulated duct 72 . Another damper 74 controls the flow of gases into the duct 50 .
Referring now to FIG. 3, media burner 48 includes a top wall 76 , a bottom wall 78 , and continuous sidewalls 80 enclosing an internal combustion chamber 82 . A plurality of ceramic members 83 , such as saddles, balls, or other shapes, are disposed within the combustion chamber 82 . The ceramic members 83 function to control the combustion process and will exhibit very high thermal inertia. The ceramic members may be any suitable shape, such as saddle shaped, round or spherically shaped, or “dog bone” shaped. An air inlet plenum 84 , which is connected to outside air as well as to the return ducts 46 and 47 , is provided for routing air and captured emissions to the combustion chamber via an air inlet valve assembly 86 . The plenum 84 includes an auger 85 to permit periodic removal of the ceramic members 83 , which may be released through the valve assembly 86 if needed.
A fuel delivery assembly 88 is provided for routing combustion fuel to the combustion chamber 82 , and includes a fuel manifold 89 and a plurality of fuel injection lances or rods 90 . The sidewall 80 of burner 48 includes a heat exchange unit 91 having a plurality of oil lines 92 which scavenge heat from the burner 48 . The oil lines 92 route heated oil to a heat exchanger 94 on each of the asphalt cement storage tanks 28 via a feed line 96 , which helps to maintain the asphalt within the storage tanks 28 in a liquid state. Burner 48 also includes a hot air outlet 97 connected to the insulated duct 50 , a pre-heater 98 for heating the burner in preparation for start up, and a system of thermocouples 100 .
As shown in FIGS. 3-5, the fuel rods 90 are arranged in a plurality of rows. Each fuel rod 90 includes an outer tube 102 having a sidewall 104 enclosing a chamber 106 . A plurality of fuel ports, for example, 108 a , 108 b , 108 c , . . . 108 n , are provided in the sidewall 104 . An inner conduit 110 is slidably disposed within each of the outer tubes 102 , with each conduit 110 including a fuel flow passage 112 terminating in an orifice 114 . The fuel passage 112 is connected to the fuel manifold 89 by a flexible hose 116 connected to an inlet end 117 of the conduit 110 . Each inner conduit 110 includes an adjustable locking collar 118 , which permits the inner conduit 110 to be adjusted relative to the outer tube 102 . A pair of spaced apart seals 120 , 122 are connected to an outlet end 124 of the inner conduit 110 , with the orifice 114 being located between the seals 120 , 122 . Accordingly, fuel from the fuel manifold 88 is routed through the flexible hose 116 , into the fuel passage 112 , and into that the portion of the chamber 106 dictated by the present location of the inner conduit 110 (i.e., the present location of the seals 120 , 122 ) relative to the outer tube 102 . The fuel exits the chamber 106 via the closest adjacent fuel port 108 a , 108 b , 108 c , or 108 n , again depending on the position of the inner conduit 110 relative to the outer tube 102 .
Referring now to FIGS. 4 — 6 , the air valve assembly 86 includes a plurality of valves, for example 86 a , 86 b , 86 c , and 86 d , each of which is shown in a different position in FIG. 6. A plurality of spaced apart holes 125 are provided in the bottom wall 78 of the burner 48 , which holes 125 communicate air from the air inlet plenum 84 to the combustion chamber 82 . A baffle member 126 is slidably mounted to the bottom wall 78 and also includes a plurality of spaced apart holes 128 , which are spaced to match the spacing of holes 125 . Accordingly, the amount of air flowing through the holes 125 can be controlled by sliding the baffle member 126 back and forth on the bottom wall 78 having the holes 125 . For example, the air flow can be maximized by sliding the baffle member 126 to the position of valve 86 a at the top of FIG. 6, or minimized by sliding the baffle member 126 to the position of valve 86 d at the bottom of FIG. 6, with valves 86 b and 86 c being shown in intermediate positions.
Although certain exemplary embodiments constructed in accordance with the teachings of the invention have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments of the teachings of the invention fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.
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An asphalt plant includes a plurality of asphalt processing components including a first set of components producing volatile emissions and a second set of components requiring process heat. A separate central burner assembly is adapted to supply heat energy in the form of heated gas to satisfy the process heat requirements of the second set of components. A first duct system is provided which includes a fan and which is adapted to capture a portion of the volatile emissions produced by the first set of components and to convey the captured emissions into the central burner assembly for mitigation. A second duct system is provided and includes a fan and is adapted to convey heated gas from the central burner assembly to the second set of components.
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BACKGROUND OF THE INVENTION
The invention concerns a spinning frame having a fiber break guard and more particularly to a fiber break guard composed of a pair of fiber guides, one of which moves laterally upon breakage of one fiber to cause separation of the other fiber.
Such a spinning frame produces yarn from two fiber bands twisted together. Further, these fiber bands in the area between the drawing system and the union point are designated as single fibers. The point at which the two fibers meet and after which they are twisted together to form yarn is designated as the union point.
The twisting of the yarn can be accomplished by normal means, preferably by means of a spindle which coaxially penetrates a spinning ring upon which a traveller moved by the yarn can rotate. It is also possible, though, to have other devices for producing the rotation and for winding the yarn, for example a rotating spinning pan, a flyer spindle, or the equivalent.
The causation of a break in the resulting fiber is desirable because the movement of the remaining fiber onto the spinning location is normally not interrupted by the breaking of only one of the two individual fibers, which means that the yarn produced after one of the fibers breaks has a correspondingly low strength.
This defective spot easily can cause breakage of the yarn during later processing, and can lead to defective goods.
Each working location on the spinning frame at which yarn is produced is designated as a spinning location.
With respect to a known spinning frame of this type (DE-Gbm No. 79 12 423), every spinning location has a fiber break guard to produce a fiber break reaction; this guard has a fiber guide for the yarn supported on a holder and movable between two positions. In the first position it is held in equilibrium, but it can be brought out of equilibrium by the influence of the yarn moving past it if it is brought beyond its movement limitations--which happens when there is a break in one of the two individual fibers. In such a case it can swing about 180° down in the vertical plane and about 90° in the horizontal plane, re-routing the remaining fiber through the fiber guide, which is sooner or later supposed to produce the fiber break reaction. There can, however, be cases where this guard fails to produce the fiber break reaction because the rotation imparted by the spindle upon the remaining fiber (allows) the fiber to propagate itself through the fiber guide and onto the drawing system.
SUMMARY OF THE INVENTION
It is therefore a task of the invention to create a spinning frame of the type mentioned above, whereby when there is a fiber break a reaction break of the remaining fibers is accomplished quickly and dependably.
The fiber guide of the fiber break guard can either by entirely displaced from its normal operating position in order to produce a break reaction, or in some cases it is especially efficient to design it such that it is not totally displaced in order to cause the break, but rather has several displaceable members which are independent of one another, at least one of which then must be displaced from its normal position to cause the break.
In one embodiment the fiber break guard according to the invention, the clamping device can in many cases be such that the remaining fibers in it are clamped tight, i.e., can no longer move in the direction of the spindle or its equivalent. Thus the fiber break takes place very quickly for the remaining fibers between the clamping device and the drawing system.
It is, however, not absolutely necessary that the remaining fibers are firmly clamped in the clamping device, but rather it can be sufficient, at least in many cases, to design the clamping device such that instead of becoming clamped in it, the remaining fibers are weakly pinched in such a way that even though they can still move through the device, the weak clamping suppresses the twisting of the fiber in the direction of the drawing system. Thus, although the remaining fibers remain tensed in the area between the drawing system and the clamping device, since those fibers are still being drawn off, in this case there is still a very rapid fiber break if there is sufficient distance between the clamping device and the drawing system. This is so because the twisting of the remaining fiber, produced by the spindle or its equivalent, does not pass into the fiber area between the drawing system and the clamping device, or at least does not pass into it sufficiently, resulting in a quick fiber break due to too little twisting.
The clamping device can be arranged so that it is stationary on the fiber break guard or some other component, or it can preferably be cut in only as a consequence of the breaking of one of the two individual fibers, since at least one of its two components is a movable component which is set off by the breaking of one of the two fibers. In such a case the break causes the engagement of the fiber guide or at least one of its movable components into the position which forms a clampdown. The rapid cutting of the remaining fiber in another embodiment can be accomplished by means of any appropriate separation device. In a preferred design form it consists of a cutting device for cutting through the thread. Another design form which is advantageous in many cases has a hot wire as a cutting device. The wire is switched on by the movement of the fiber guide or one of its components and the hot wire then burns through the remaining fiber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a cross-sectional front view of a spinning location of a spinning frame (not illustrated in detail) with a fiber break guard in accordance with a first design example of the invention.
FIG. 2 shows a side view of the fiber break guard as in FIG. 1 but in enlarged size.
FIG. 3 is a rear view of the fiber break guard as in FIG. 2.
FIG. 4 shows a top view of the fiber break guard as in FIG. 2.
FIG. 5 shows a cross-sectional side view of a spinning location with a fiber break guard in accordance with a second design example of the invention.
FIG. 6 is a front view of the fiber break guard as in FIG. 5, in enlarged size.
FIG. 7 is the fiber break guard as in FIG. 6, but in a position which clamps down on the remaining fibers.
FIG. 8 is a partial front view of a spinning location with a fiber break guard in accordance with a third design example of the invention.
FIG. 9 is a top view of the fiber break guard as in FIG. 8, in enlarged view, whereby the electrical circuit for switching on the cutting device is schematically illustrated in part.
FIG. 10 is a variant of the spring of the fiber guide as in FIG. 9, with one of these springs being illustrated in side view, showing the use of the hot wire with the spring instead of the cutting device in FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 the delivery roller pair of a single or multiple drafting zone drawing system (not illustrated in detail here) of a ring spinning frame is designated as 10.
The drawing system draws at the illustrated spinning location 9 two parallel-running fiber bands 11, 12, which can preferably consist of combed wool or if the case may be, other fibers, and which are delivered preferably from a single supply spool (not illustrated), and which after drawing move out of the delivery roller pair 10 while still untwisted. The main drafting zone of the drawing system can have the usual apron leading between the two fiber bands 11, 12. These two fiber bands 11, 12 are guided with considerable clearance from one another by a fiber band guide, not illustrated, and after leaving the delivery roller pair 10 as single fibers 11', 12', they run together at acute angles and meet at the union point 13, where they are twisted together by means of a spindle 15 and traveller 17 rotating about a spin ring 16 in order to form yarn 14. The yarn 14 moves to a fiber guide 19 located above the spindle 15, upon which the so-called fiber balloon begins, which corresponds to the area of yarn which rotates around the spindle 15 and reaches from the fiber guide 19 to the traveller 17. The yarn 14 produced is then wound into a roll 20 on a bobbin placed on the spindle 15.
The union point 13 wanders up and down somewhat during operation, and also somewhat from side to side.
Adjacent the union point 13 a fiber break guard 22 is located on a rail-shaped carrier running horizontally along the given side of the spinning frame. The guard serves several functions and is illustrated in more detail in FIGS. 2 through 4. When both single fibers 11' and 12', and thus the yarn 14 moving to the spindle 15 are available, it serves to limit the lateral deviations of the union point 13 with respect to the direction parallel to the length of the carrier 21. It also serves to generate the thread breaking reaction for the remaining fiber when one of the individual fibers 11' or 12' breaks. This remaining fiber moves from the delivery roller pair 10 to the spindle 15 and is illustrated by way of example in FIG. 1 and designated at 14'. This fiber break guard 22 has a beam 23 attached firmly to the carrier 21 which is stiff and hook-shaped. On this hook-shaped beam is a pivotally-mounted fiber guide 24 made of a bent, stiff wire which pivots parallel to the lengthwise direction of the carrier 21. This fiber guide 24 juts out with its free upper basically straight arm 25 into the normal operational position of FIG. 2 between the two individual fibers 11', 12', and as a consequence of its own weight, which tends to turn it in a clockwise direction in relation to FIG. 2, lies upon the union point 13 of the two individual fibers 11', 12', and is thus pivoted along with the union point 13 during operation. As a result of its location on the union point, this fiber guide 24 serves to guide the yarn 14. In order that the two individual fibers 11' and 12', which have a necessary distance from one another, cannot bind with one another above the arm 25, which under certain circumstances could impair the function of the fiber guide 24, a separation lever 26 is located on the beam 23 of the swing axle, pivotally-mounted on the same axis as the pivot axle of the fiber guide 24. The lever 26 is movable from the position indicated by the dotted lines in FIG. 2 all the way to the fully extended operational position. The movement can be done by hand, and once completed the lever remains in the engaged position 27 due to its own weight. The upper carrier arm 26, which in operational position is roughly horizontal, is part of the right-angled separation lever 26 and juts out at a distance above the arm 25 of the fiber guide 24 and roughly parallel to it, and between the two individual fibers 11' and 12', thus preventing the fibers from the individual fibers 11', 12' from binding with one another above the arm 25.
At the bend of the shank 28 of the fiber guide 24, directed upward in FIG. 2, a cylinder 29 running parallel to the rotational axis 62 of the fiber guide 24 is firmly attached on the inner side. In case of a fiber break for one of the two fibers 11', 12' this cylinder moves into the lower position indicated by the dotted lines and clamps the remaining fibers 14' between itself and the opposite piece 30 which runs parallel to the carrier 21 is and mounted on the beam 23. This takes place as a consequence of the weight of the fiber guide 24 and the swinging of the guide in a clockwise direction (FIG. 2). This cylinder 29 thus forms, together with its opposite piece 30, a clamping device.
In this dotted-line "clamping position" of the fiber guide 24 its arm 25 lies on a narrow rear slit 31 of the opposite piece 30. If a fiber break is to be eliminated, the operating person swings the fiber guide 24 and the separation lever 26 into the upper position indicated by the dotted lines in FIG. 2, and after repairing the break, swings the fiber guide 24 and the separation lever 26 back into the operational positions indicated in FIG. 2. If thereafter one of the two individual fibers 11' or 12' should break, the fiber guide swings in a clockwise direction due to its own weight as already described, until it is considerably below the union point 13 and further than the maximum fiber length of the fiber bands 11 and 12, which corresponds to a clampdown position in which it clamps the remaining fiber 14' between itself and its opposite piece 30. Then it is unimportant for the rapidly following fiber break whether the clamping force was so strong that the fiber is immovable, or whether the fiber is merely pinched somewhat between parts 29 and 30 and can still move in the direction of the spindle 15. In either case the pinching of the remaining fiber 14' between the cylinder 29 and the opposite piece 30 prevents any propagation of the twist to the remaining fiber 14', by means of the traveller 17 rotating about the ring 16, beyond the clamping device where the remaining fiber 14' is clamped down. In either case the break of the remaining fiber located between the delivery roller pair 10 and the clamping device occurs very rapidly.
The free arm 25 of the fiber guide 24 is, in this design example, somewhat angled downward (cf. FIG. 2) so that the union point 13 will not wander out over the free end of the arm 25 during operation.
In the design example according to FIGS. 5 through 7, a fiber break guard 22 is arranged on a carrier 21 which runs horizontally along the spinning frame. It has as a fiber guide two springs 24', 24' which are located in a holding piece 23' mounted on the carrier 21; these springs are essentially straight and made out of spring wire. On their free ends they are angled off at right angles.
On both ends of the holding piece 23' there are two overlapping, leaf-shaped clamping pieces 32, 32' which are pivotally-mounted on parallel axles with relatively low angles to the horizontal. These two clamping pieces 32, 32' have the same shape and in their operational position as in FIG. 6 mirror each other, thus forming a wide entry channel 33 for entry of the yarn 14. This entry channel 33 widens into a basically round bay 34. The yarn 14 moves through the middle of the bay at an angle between the springs 24' 24" which bridge the bay and are open at the rear (FIG. 6) during normal operation. These springs 24',24" limit the lateral motion of the yarn 14 parallel to the lengthwise direction of the carrier 21 which results from normal operation. The clamping pieces 32, 32' are adjacent to the rear of the holding piece 23' as in FIG. 6 and have flanges 35 which are angled away so that they cannot be swung further outward but rather swing downward as a result of their own weight via the springs 24', 24" which are basically positioned to hold them straight as in FIG. 6. The force with which the downward-facing free ends of the springs 24', 24", in their situation at the nose of the clamping pieces 32, 32', actually hold these pieces in an upright position, is very small. Thus, if one of the two individual fibers 11' or 12' breaks and the remaining fiber 14' thereby deviates to the sides, the remaining fiber 14' causes the spring 24' or 24" to bend due to the friction between it and the nose of the related clamping piece 32 or 32', which in turn releases the appropriate clamping piece 32 or 32'. This clamping piece then immediately swings downward due to its own weight and brings the remaining fiber 14' with it, clamping it between itself and the other clamping piece 32 or 32'. If, for example, the right-hand individual fiber 12' breaks (cf. FIG. 6), the remaining fiber 14' first displaces itself to the left and presses the spring 24' to the left, away from the nose of the clamping piece 32. Thereby this clamping piece 32 swings downward into the position depicted in FIG. 7 and takes the remaining fiber 14' along with it and clamps it between itself and the other clamping piece 32' as in FIG. 7. This quickly leads to a fiber break of the remaining fiber 14', in which case the twist imparted on the fiber by the spindle can no longer be propagated beyond the two clamping pieces 32, 32'. Thus the remaining fiber area 14' between the delivery roller pair 10 and the clamping device quickly breaks.
For the design variation in FIGS. 8 and 9, a fiber break guard is attached to a carrier 21. The guard has a fiber guide consisting of two straight springs 24b, 24c. These springs 24b, 24c are firmly suspended on stiff holding arms 40, which in turn are located on a carrier 21, vertically in relation to it and angled somewhat foreward. The springs 24b, 24c extend parallel to the holding arms 40 go between them, and then extend roughly horizontally to the rear. The spread-out free ends of the holding arms border within themselves a funnel-formed gap 41 which branches into the fiber guide gap formed by the two springs 24b, 24c and through which the yarn 14 moves with side play. When the fiber break is being repaired, the yarn 14 can easily be threaded into the fiber guide gap by the operator.
In addition, a contact fork 43 insulated from the carrier 21 by electrical insulation is mounted on that carrier, between which the free ends of the two springs 24b, 24c intrude, carrying electrical contacts which can be depressed to close an electrical circuit with the contact fork 43. Each spring 24b and 24c thus forms an electric circuit 45, 45' with the contact fork 43. The contact fork 43 is connected to a voltage source 46 and the two springs 24b, 24c are grounded via the holder arms 40. A relay 47 is located in the line from the voltage source 46 to the contact fork 43; it opens and closes a switch 48 which is normally open and is closed by excitement of the relay. This switch 48 serves to open and close an electrical circuit 55 into which the exciter coil 51 of an electromagnet (not illustrated further) is connected and further serves to activate a cutting device 50, located below the fiber break guard 22, so as to cut the individual fiber 14' when one of the fibers 11', 12' has broken. This is shown by the dotted lines in FIG. 8. Since electrically activated cutting devices are basically known, they need no further explanation.
The relay 47 is preferably designed such that it only closes the switch 48 when the switch 45 or 45' which activates it is closed for a small minimum time without interruption. This is so because the springs 24b and 24c can be moved so as to close the switch 45 not only by the remaining fiber 14', but also by strong lateral deviations of the yarn 14, which can close the switch 45, 45' for a short period of time. On the other hand, the lateral deviation of the remaining fiber causes a longer closing of the relevant switch 45, 45' such that only a break in the fiber of 11', 12' leads to a closing of the switch 48 and thus to a cutting of the remaining fiber 14'.
This fiber break guard as in FIGS. 8 and 9 also ensures that a quick and dependable breaking of the remaining fiber will take place whenever there is a break in one of the individual fibers 11', 12'.
The cutting device 50 can also be replaced by another separation device for separating the remaining fiber. Thus, hot wires 52 can be used instead for burning through the fiber. Instead of the exciter coil 51, they are placed in series with the voltage circuit 55, or parallel to one another. These hot wires 52 should be arranged along both sides of the yarn 14 path such that at least one hot wire comes in contact with the remaining fiber 14' which is designated by dotted lines in FIG. 8 after there has been a break in one of the two individual fibers 11', 12'. The remaining fiber 14' causes the unaffected spring 24b and 24c to bend and close the appropriate switch 45 or 45'. The hot wires 52 are switched on by the relay 47 of the switch 48 by means of this switch 45 or 45' and the remaining fibers are quickly burnt through, and thus the break of the remaining fibers 14' is achieved.
Thereafter the spring 24b or 24c which was involved returns to its original position as illustrated in FIG. 9 upon opening of the switch 45 or 45', and switches the hot wires 52 off again.
The hot wires 52 can be arranged away from the springs 24b, 24c, but it is more advantageous and also simpler and safer to have them arranged along the lengthwise side of the springs 24b, 24c where they face the yarn 14, and to electrically insulate them, as is illustrated in FIG. 10. FIG. 10 shows such springs 24b and 24c in the corresponding side view, whereby the electrically isolated hot wire is designated as 52.
It is also possible to have an electromagnetically activatable clamping device for clamping down the remaining fiber 15', rather than a cutting device 50. The clamping device would clamp down the remaining fiber 14' so that it breaks whenever there has been a closing of the switch 45 or 45'.
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A spinning frame is provided with a fiber break guard having a fiber guide which as a consequence of the breaking of one of the individual fibers is displaced to cause the breaking of the other fiber. For a certain and rapid breaking of the remaining fiber, the displacement of the fiber guide caused by the remaining fiber, or at least the displacement of an associated member causes a pinching of the remaining fiber in a clamping device or the activation of a fiber separation device for cutting through the remaining fiber.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of swimming pool appliances, and more particularly to a novel attachment device for joining a tool or appliance to the end of a handle which permits detachable connection for tool or appliance replacement purposes.
2. Brief Description of the Prior Art
In the past, many attachment devices have been provided for securing a swimming pool tool or appliance to a handle, such as disclosed in U.S. Pat. Nos. 4,106,157 or 4,169,331. Although these prior devices have been useful for their intended purpose, problems and difficulties have been encountered which stem largely from the fact that the frame holding the tool or appliance is not readily releasably connected to the end of the handle so that changes can be made with ease and without the use of special tools. The tool or appliance requires replacement from time to time and it is preferred that such changeability take place at the pool site in a convenient manner. Such changeability is best performed by a person not requiring special skills and which may be accomplished with simple hand tools usually available at the home site.
Therefore, a long-standing need has existed to provide an attachment device for releasably securing a swimming pool tool or appliance to the end of a handle which is convenient and does not require special skills, and which will readily accommodate the joining of prongs carried on an appliance frame to a flattened tube ending so that the tool or appliance may be readily replaced or changed.
SUMMARY OF THE INVENTION
Accordingly, the above problems and difficulties are avoided by present invention which provides for a novel attachment device whereby a pair of prongs outwardly extending from the tool or appliance may be received into a flattened open-ended tubular receptacle which includes crimping or clamping means disposed on either side of the joint which includes a threadable fastener that bears against the joint when tightened so as to releasably retain the prongs within the receptacle. In one form of the invention, the crimping or clamping device includes a pair of washers disposed and separated on opposite sides of the joint with the fastener passing therethrough. In another form of the invention, a clamp member of U-shaped configuration in side elevation is employed having flattened sections residing on opposite sides of the joint and having a fastening means disposed therethrough. In still a further embodiment, a plug member is employed having a slotted opening for insertably receiving the prongs of the appliance whereby cantilevered sections of the plug reside on opposite sides of the prongs and fastener means passes therethrough for applying clamping pressure.
Therefore, it is among the primary objects of the present invention to provide a novel attachment device for joining a swimming pool tool or appliance to a handle which includes a clamping or crimping means to releasably hold the appliance to the handle, and which may be released without special equipment or special skills.
Another object of-the present invention is to provide a novel attachment device for releasably securing a swimming pool tool or appliance to the end of a handle whereby the device is changeable at the pool site.
Another object of the present invention is to provide a novel releasable clamping or crimping means for joining the prongs of a pool tool or appliance with the end of a handle employing a clamping pressure to hold the joint in place.
Still a further object of the present invention is to provide a novel attachment device for a swimming pool tool or appliance which is economical to manufacture and which is simple to install whereby the tool or appliance is removably and releasably attached to the end of a handle.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood with reference to the following description, taken in connection with the accompanying drawings in which:
FIG. 1 is a top plan view illustrating the novel attachment device for a swimming pool tool or device incorporating the present invention;
FIG. 2 is a side elevational view of the attachment device shown in FIG. 1 illustrating the self-returning feature of the joint;
FIG. 3 is an enlarged-transverse cross-sectional view of the attachment device shown in FIG. 1 as taken in the direction of arrows 3--3 thereof;
FIG. 4 is a top plan view of another embodiment of the present invention illustrating the pattern for the device;
FIG. 5 is an exploded perspective view showing the device formed from the pattern of FIG. 4;
FIG. 6 is an exploded perspective view showing another version of the present invention employing a plug in the attachment device;
FIGS. 7 and 8 are enlarged plan views illustrating the assembly of the joint with the attachment device as illustrated in FIG. 6;
FIGS. 9 and 10 illustrate another version of the present invention using a clamp or crimping means similar to that illustrated in FIGS. 4 and 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the figures, the present invention relates to a flexible hinge and attachment structure for connecting a swimming pool tool or appliance, such as a skimmer or scoop net, with a handle utilized to manipulate the working element.
Referring to FIG. 1, the handle is indicated by numeral 10 while the tool or implement or appliance intended to be manipulated is indicated by numeral 11 which takes the form of a net carried on a frame 12. The frame terminates in a pair of prongs 13 and 14 which are accepted into and held by an attachment device indicated in the direction of arrow 19.
The handle 10 is a hollow tubular member which may be a full length handle or it may be a short length of tubing to which an additional length of tubing may be suitably attached to provide the desired length. As is the conventional practice, the handle 10 has a working end which is adapted to receive the attachment means or device 19, which will be described hereinafter, and a second or connector end section 15 for connecting to a tubular extension 16. Connection of the handle 10 to the tubular extension may be made by any suitable means. For example, a standard V-shaped spring clip 18 having a pair of detents 20 and 20' projecting outwardly from the free ends thereof may be disposed within the connector end section 15 so that the spring-urged locking detents extend radially outwardly through a pair of aligned apertures 21 and 21' respectively which are defined by the connector section 15 along a diameter thereof. The handle extension 16 may be slipped over the depressible locking detents to snap the latter into locking position in the aligned openings respectively defined by the handle extension.
The skimmer 11 comprises an open frame formed into a desired shape with a net 23 suitably attached thereto and depending therefrom. The frame is formed from a resilient flexible metal which, because of its physical characteristics and diameter, can be bent into any desired shape, but which will retain the shape during normal skimmer use. The prongs 13 and 14 included with the frame are also composed of the resilient flexible metal material.
Referring now in detail to FIGS. 1-3 inclusive, the novel attachment means 14 of the present invention includes a selected end of the extension 16 being flattened, as shown in FIG. 3, so that the previous tubular construction defines a pair of receptacles indicated by numerals 24 and 25 suitable for insertably receiving the prongs 13 and 14 respectively. In this flattened configuration, the opposite sides of the tubular end are engaged with and between a pair of washers 26 and 27 which are drawn together in a crimping or clamping relationship by a threadable fastener 28. In a preferred form of the fastening means, a carriage bolt 30 is employed having a threaded shank 31 which passes through the washers 26 and 27 as well as through a pre-formed opening in the end of the extension section 16 which has been flattened. The opening is broadly indicated by numeral 32. Preferably, the opening in the washer 26 is of a square configuration in order to accommodate the square shoulder immediately under the head of the carriage bolt 30 so that the bolt will not slip during tightening by means of a thumbnut 33 threadably engaged with the shank 31 on the opposite side of the attachment means.
Therefore, it can be seen that upon placing the prongs 13 and 14 into the receptacles 24 and 25, followed by rotation of wingnut 33, the opposing surfaces of washers 26 and 27 will be drawn together against the opposite sides of the flattened end section of the extension 16. In so doing, the innersurface of the tubular section which has been flattened will bear against the prongs in a clamping action. In fact, the material of the tubular extension will or may deflect and physically deform to accommodate the clamping action. In order to retain the pair of washers in place when it is desired to unclamp or even remove the fastener 28, a spring roll pin 34 is included which passes through an opening in alignment with an opening in the washers and flattened portion of extension 16. The roll pin may be punched out when it is desired to remove the washers from installation on the extension section 16.
As illustrated in FIG. 3, the frame is composed of a flexible spring metal so that a hinge action is produced, as shown in broken lines, for the net or skimmer 11.
Referring to FIGS. 4 and 5, another embodiment of attachment means is illustrated in the general direction of arrow 35 which will releasably hold prongs 13 and 14 of the skimmer 11 in place on the end of extension 16. As illustrated, the extension is flattened in the same manner as previously described, and the flattened end is indicated by numeral 36. A U-shaped member 37 is slidably introduced over the end 36 until the terminating end bears against an end plate 38 separating an upper flange 39 and a lower flange 40. The end plate 38 is shorter than the width of the member so that opposite spaces 41 and 42 are available to insertably receive the prongs 13 and 14 respectively. Once the member 37 has been placed on the flattened end 36 of extension 16, a carriage bolt 43 having a square shoulder 44 and a threaded shank 45 is introduced through aligned openings 46 in the upper and lower flanges 39 and 40 and through the opening 47 in the flattened end 36 of extension 16. The shoulder 44 is fitted into the square opening 46 on the flange 39. When a thumb of wingnut 48 is threadably engaged with the threaded shank 45, the head 43 of the carriage bolt and the nut 48 will bear against the external surfaces of the flanges or plates 39 and 40. It is to be particularly noted that the central portion of the flanges or plates 39 and 40 include a flexible tang 50 and 51 which compress against the opposite sides of the flattened end 36 to cause the flattened end to crimp or clamp against the prongs which are inserted into the opening of the member 37 and in the hollow of the end 36. Thus, a clamping action is produced so that a strong interference fit exists between the inside surface of the flattened end and the prongs.
Referring now to FIGS. 9 and 10, another embodiment of the invention is illustrated in the general direction of arrow 60 wherein the prongs 13 and 14 of the skimmer 11 are introduced into the hollow of the flattened end 36 of the extension 16 by passing through an opening 61 in the end of a U-shaped member 62 having an upper plate 63 and a lower plate or flange 64. The-plates or flanges include aligned central openings, such as the square opening 65, so as to be in alignment with a hole or opening 66 in the end 36. When the member 63 is inserted onto the end 36 by passing the end through opening 61, the holes in the member and the end 36 are in alignment so that the carriage bolt 67 can be passed therethrough in the same manner as described with respect to the embodiment shown in FIGS. 4 and 5. A wingnut 68 is used to effect a clamping action on the member 63 so that its respective plates will bear against and crimp or clamp against the flattened end 36 causing it to grip the prongs 13 and 14.
Another embodiment. Of the novel attachment means is shown in FIGS. 6, 7 and 8 and is indicated in the general direction of arrow 70. This embodiment includes a cylindrical plug 71 having a through slot 72 for insertably receiving the prongs 13 and 14 of the skimmer 11. A clamping action is produced by means of threading the nut 73 onto the threaded shank of carriage bolt 74, as previously described. A central opening passes through the entire plug and is indicated by numeral 75. The shank of the carriage bolt enters the opening, passes between the prongs 13 and 14 within the slot 72, and continues through an aligned opening within the plug for threadable engagement with the nut 73. The slot 72 provides an upper section 76 and a lower section 77. By tightening the nut 73, the two plug sections are drawn together to engage with and hold the prongs 13 and 14.
With respect to FIGS. 7 and 8, different prongs are illustrated in that in FIG. 7 the prongs 13 and 14 are somewhat parallel to one another while in FIG. 8, the prongs are stepped at numerals 78 and 79 within the slot 72.
In view of the foregoing, it can be seen that the prongs 13 and 14 of the skimmer 11 can be removably connected and attached to the end of the extension 16 by either the arrangement shown in FIGS. 1-3 or in FIGS. 4-5 or FIGS. 9 and 10 or FIGS. 6-8 inclusive. Each of these ways is economical and provides a crimping or clamping action against the prongs once they are inserted into the extension whether the extension be a plug, such as plug 71, or a flattened end piece 36 connected with tube 16. The resultant connection, provides for flexibility and extablishes a hinge action, such as shown in broken lines in FIG. 2.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.
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An attachment device is disclosed incorporating a self-returning hinge releasably joining a pair of prongs disposed on a basket frame with a flattened open end of a tubular handle member. A crimping device is carried at the joint operable to be forcibly compressed to crimp or frictionally engage the device with the flattened open end to secure the prongs in place. The frame and prongs are composed of a flexible spring metal so as to constitute a self-returning hinge when the frame is bent or pushed to-either side of a handle center line.
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BACKGROUND
Prior Art
[0001] The following is a tabulation of various prior art that appears presently relevant:
[0000]
U.S. Patents
Pat. No.
Kind Code
Issue Date
Patentee
582,485
(N/A)
1897-5-11
Reeves, Reeves
4,574,914
A
1986-3-11
Flugger
7,219,764
B1
2007-5-22
Forbes
1,029,162
B1
2005-3-23
Flugger
5,434,374
A
1995-7-18
Tien-Chu Hsueh
20040108162
A1
2004-6-10
Gilles Couvrette
NONPATENT LITERATURE DOCUMENTS
[0000]
Wilder, Jim, Undercar Digest , “A Different Muffler, Going to Market Differently” (April 2009)
[0003] Since the advent of the internal combustion engine, people have sought to control its sound. Milton and Marshall Reeves were presumably the first to address this dilemma; their patent for “Exhaust-Muffler For Engines” was issued in 1897. Their muffler, along with other mufflers of the time (and today), was intended only to attenuate sound. Over time, a significant demand grew for mufflers with pleasing sound and greater exhaust gas flow. Greater flow results in better engine performance and increased fuel economy, but is difficult to achieve in mufflers due to the back-pressure created by manipulating exhaust. Muffler manufactures responded to the demand for greater flow with a limited degree of success.
[0004] Several designs (such as Flugger's) have sought to achieve low back-pressure, and (perhaps to a lesser extent) pleasing sound. Low back pressure (greater flow) results in better engine performance and increased fuel economy, but there is a limit on how much flow can be achieved. Virtually all mufflers rely on either physically altering the path of exhaust gasses (passive-reactive type), using sound absorbent material (absorptive type), or both. Due to this, undesirable back pressure is invariably created, and is particularly extreme on mufflers designed to fully silence.
[0005] Several ideas have been proposed to deal with the problem of back pressure, but virtually all fail to some degree. A particularly interesting proposition is the active-reactive muffler. In essence, active-reactive mufflers function by electronically monitoring the sound produced by exhaust, then sending noise canceling sound waves back into the exhaust system via a speaker. Although this seems promising at face value, it results in many new problems and limitations. Active-reactive mufflers have existed for decades, but have seen comparatively little commercial success. Reasons for this include:
[0006] (a) The sheer sophistication of the system results in the risk of component failure; the computer could malfunction, the sensors could degrade in the presence of exhaust gasses and heat, the speaker could rupture, the cables could corrode, etc.
[0007] (b) The expense of implementing such a system is typically much greater than a traditional muffler.
[0008] (c) It is likely unfeasible or perhaps impossible to selectively control sound cancellation well enough to compete in the performance exhaust market.
[0009] (d) It is difficult to account for different types of engines, and therefore difficult or impossible to fully incorporate into the aftermarket.
[0010] Amongst engine and automobile enthusiasts, we have found that pleasing sound is at least as important as exhaust flow. Although modern performance mufflers offer more sound than mufflers intended for silencing, there are still many problems that plague the industry. Attempts at correcting these problems have been mediocre at best.
[0011] A particularly notorious problem among exhaust (especially performance exhaust) is what is popularly known as “drone”. Especially prominent among “welded-type” mufflers (such as Flugger's), drone refers to a sustained low frequency tone that can be heard at certain RPMs. This noise is usually perceived as irritating and undesirable. Some mufflers are less prone to this problem, but have other problems in its place. Forbes has recently found a possible, partial solution to drone, but offers no indication that any other issues are addressed.
[0012] Another common problem we have found among performance mufflers is a popping sound, which usually occurs during rapid drops in RPM (such as releasing the accelerator pedal). This phenomenon is created by pockets of exhaust gasses building and releasing. This can be caused by engine issues, back-pressure, low pressure zones in mufflers, and a plethora of other variables. This problem is often exacerbated by tail pipes. Popping exhaust is a fairly common problem, but extremely difficult to circumvent with mufflers designed for medium to loud volume.
[0013] We have found that a lack of refined sound (a “muddy” tone) is extremely common across the entire performance muffler spectrum, and is often perceived among consumers as “unnatural”, “undesirable”, or just plain “ugly”. This is because it is difficult to improve the underwhelming sounds of a damaged or non-performance engine via exhaust. Although some attempts have been made to offer performance sound to stock and/or aging engines, we have found the results to be lackluster at best. While it is true that some muffler designs may make engine problems less audible, we have found that the sound is not at all comparable to a true performance engine.
Advantages
[0014] Accordingly, several advantages for one or more aspects are as follows: a muffler that has extremely low back-pressure, is highly reliable, is suitable for a wide variety of markets, that addresses problems such as “drone” and “popping”, that provides a crisp and natural sound, and that potentially corrects undesirable sounds produced by an engine. Other advantages of one or more aspects will become apparent after consideration of the drawings and ensuing description.
SUMMARY
[0015] In accordance with at least one embodiment: a muffler with a case comprising a body, at least one inlet, and at least one outlet. A plurality of elongated members produce resonance when subjected to flowing exhaust gasses, which results in noise canceling and/or sound enhancing tones. Sound altering devices, such as sound baffles, sound absorbent material, and/or electronic noise canceling may be used in addition to the elongated members.
GLOSSARY OF TECHNICAL TERMS
[0000]
Absorptive Muffler: A muffler that utilizes sound absorption.
Active-Reactive Muffler: A muffler that utilizes electronic sound cancellation.
Aftermarket: The market in which third-party parts companies compete.
Attenuation: To reduce sound levels.
Back Pressure: Restriction in the exhaust of an engine.
Body: In this specification, the body is the main section of a muffler. It typically (but not always) houses most or all of the internal components. A body is part of a case.
Branches: In this specification, “branches” refers to elongated members that stem from other elongated members.
Case: In this specification, the case is the body, inlet, and outlet of a muffler.
Cylinder: A three dimensional shape with straight parallel sides and a circular or oval section.
Drone: A sustained, usually low frequency tone that is typically considered undesirable.
Elongated Members: In this specification, “elongated members” refers to elongated members possessing resonating properties (refer to detailed description and operation for FIG. 1 , and claims for a specificities).
Holding Ring: A device that allows components to attach to the case.
Inlet: The entrance of a muffler. Part of the case.
Muffler: A device that alters the sound of exhaust produced by an internal combustion engine.
Outlet: The exit of a muffler. Part of the case.
Passive-Reactive Muffler: A muffler that utilizes sound deflection.
Perforation: Holes in an object.
Polyhedron: A three dimensional shape with multiple sides.
Popping: An undesirable sound that can occur in exhaust systems, particularly during rapid drops in RPM.
Resonance: Sound created as a reaction from a stimulus.
(Sound) Absorption: To absorb sound (through materials such as fiberglass, steel wool, etc.) for the purpose of noise canceling and/or altering tone.
(Sound [or Deflection]) Baffle: A device used to create sound deflection.
(Sound) Deflection: Manipulating the path of sound waves to create sound canceling effects.
Suspend: To hang.
Tail Pipe: Exhaust pipe after a muffler.
DRAWINGS
Figures
[0041] FIG. 1 shows a perspective view of the first embodiment, with two elongated members, and a small cylindrical-bodied case.
[0042] FIG. 2 shows an embodiment with a deflection baffle.
[0043] FIG. 3 shows an embodiment with a third elongated member.
[0044] FIG. 4 shows an embodiment with an oval deflection baffle, stemming from an outlet.
[0045] FIG. 5 shows an embodiment with a “v”-shaped deflection baffle, stemming from the outlet.
[0046] FIG. 6 shows an embodiment with multiple sets of elongated members.
[0047] FIG. 7 shows an embodiment with cylindrical elongated members.
[0048] FIG. 8 shows an embodiment with a set of perforated cylindrical elongated members, and a set of non-cylindrical elongated members.
[0049] FIG. 9 shows an embodiment with perforated cylindrical elongated members.
[0050] FIG. 10 shows an embodiment with elongated members attached inside a muffler body (in this case, using a holding ring).
[0051] FIG. 11 shows an embodiment with multiple sets of elongated members attached to the body (in this case, using a holding ring).
[0052] FIG. 12 shows an embodiment with a set of elongated members attached to an inlet, and a set of elongated members attached to the body (in this case, using a holding ring).
[0053] FIG. 13 is a plan view of an embodiment with flat (technically polyhedral) elongated members.
[0054] FIG. 14 shows an embodiment with a “v”-shaped deflection baffle (attached to the body).
[0055] FIG. 15 shows an embodiment with sound absorbent material.
[0056] FIG. 16 shows an embodiment with three elongated members.
[0057] FIG. 17 shows an embodiment with multiple, branching elongated members.
[0058] FIG. 18 shows an embodiment with a large cylindrical-bodied case.
[0059] FIG. 19 shows an embodiment with a large cylindrical-bodied and a deflection baffle.
[0060] FIG. 20 shows an embodiment with a large cylindrical-bodied case and elongated members attached to the body (in this case with a holding ring).
[0061] FIG. 21 shows an embodiment with a large cylindrical-bodied case and multiple sets of elongated members.
[0062] FIG. 22 shows a perspective view of an embodiment with a full baffling system.
[0063] FIG. 23 shows a plan view of the embodiment in FIG. 22 .
[0064] FIG. 24 shows an embodiment with a polyhedron case.
[0065] FIG. 25 shows an embodiment with curved elongated members
DRAWINGS
Reference Numerals
[0000]
50 A: small cylindrical-bodied case
50 B: large cylindrical-bodied case
50 C: polyhedral-bodied case
10 : small cylindrical body
10 B: large cylindrical body
10 C: polyhedral body
12 : inlet
14 : outlet
16 A- 16 MM: elongated member
18 A- 18 M: elongated member assembly
20 : deflection baffle
24 : oval deflection baffle
26 : suspended “v”-shaped deflection baffle
28 A- 28 D: holding ring
30 : body-mounted “v”-shaped deflection baffle
32 : sound absorbent material
34 : baffle assembly
36 : baffle assembly front cradle
38 : baffle assembly holding ring
40 : perforated baffle 1
42 : perforated baffle 2
44 : perforated baffle 3
DETAILED DESCRIPTION
FIG. 1 —First Embodiment
[0088] One embodiment of the muffler is illustrated as a perspective view in FIG. 1 . The figure shows a small cylindrical-bodied case 50 A, comprised of a small cylindrical body 10 , an inlet 12 , and an outlet 14 . An elongated member assembly 18 A, comprised of two elongated members 16 A and 16 B, is attached inside the inlet 12 . The elongated members 16 A and 16 B are made of steel in this embodiment, but can be made of any material capable of sufficient resonance. The elongated members in this embodiment are partial cylinders.
OPERATION
FIG. 1 —First Embodiment
[0089] When the inlet 12 is attached to the exhaust system of an engine (not shown), exhaust gasses are allowed to pass through the small cylindrical-bodied case 50 A. As the gasses (and their sound waves) pass by elongated member assembly 18 A, elongated members 16 A and 16 B respond by vibrating. This is possible because the members are made of a resonant material (in this embodiment, steel), and because they extend sufficiently past their final attaching point (in this embodiment, the inlet 12 ). As a result of the vibrations, resonant tones are generated. These resonant tones can be noise canceling, sound enhancing, or both. Because the members are directly excited by the exhaust gasses, the tones generated are directly correlated to the natural sound of the exhaust. The members are capable of producing sound waves opposite of some or all of those produced by an engine. This phenomenon results in the sound waves collapsing, creating noise cancellation. It is also possible for the members to generate additive tones when vibrating, which results in a more pleasing sound. Because there is very little to physically get in the way of exhaust gasses, back-pressure is extremely low. As of this time, we have found that 2 half-pipe-shaped steel members about 20 centimeters long works well across a wide variety of applications for a combination of noise canceling and pleasing sound. However, the device is not limited to these specifications in any way. Different materials, lengths, shapes, different numbers of members, etc. can be used.
DETAILED DESCRIPTION
FIG. 2 —Second Embodiment
[0090] FIG. 2 shows the same elements as FIG. 1 , with the addition of a deflection baffle 20 .
OPERATION
FIG. 2 —Second Embodiment
[0091] After passing by elongated member assembly 18 A (the effect described in the operation of FIG. 1 ), some of the exhaust gasses flow directly out of the case 50 A, while some are forced to the sides of deflection baffle 20 , where they deflect between the baffle and the small cylindrical body 10 . This results in further noise cancellation. The gasses eventually flow out of the case 50 A via the outlet 14 .
DETAILED DESCRIPTION
FIG. 3 —Third Embodiment
[0092] FIG. 3 shows the same elements as FIG. 1 , with elongated member assembly 18 AA in place of elongated member assembly 18 A. Elongated members 16 Z, 16 A, and 16 B make up elongated member assembly 18 AA.
OPERATION
FIG. 3 —Third Embodiment
[0093] As described in the operation of FIG. 1 , elongated members 16 A and 16 B create resonance as exhaust gasses flow by them. The addition of elongated member 16 Z changes the nature of the resonance. As well, the “v”-shaped tip of elongated member 16 Z slows down the exhaust gasses, allowing them to be further altered.
DETAILED DESCRIPTION
FIG. 4 —Fourth Embodiment
[0094] FIG. 4 shows the same elements as FIG. 1 , with the addition of an oval deflection baffle 24 which is attached to the outlet 14 and protrudes into the small cylindrical body 10 .
OPERATION
FIG. 4 —Fourth Embodiment
[0095] After passing by elongated member assembly 18 A, the flow of the exhaust gasses is interrupted by oval deflection baffle 24 . Exhaust gasses are forced to go around the baffle, which slows down the flow, as well as creates noise canceling deflection between the baffle and the small cylindrical body 10 .
DETAILED DESCRIPTION
FIG. 5 —Fifth Embodiment
[0096] FIG. 5 shows the same elements as FIG. 1 , with the addition of a suspended “v”-shaped deflection baffle 26 which is attached to the outlet 14 and protrudes into the small cylindrical body 10 .
OPERATION
FIG. 5 —Fifth Embodiment
[0097] FIG. 5 operates the same as FIG. 4 , with suspended “v”-shaped deflection baffle 26 in place of the oval deflection baffle 24 . This results in different sound characteristics than other embodiments.
DETAILED DESCRIPTION
FIG. 6 —Sixth Embodiment
[0098] FIG. 6 shows the same elements as FIG. 1 , with an elongated member assembly 18 B (comprised of two elongated members 16 E and 16 F) in place of elongated member assembly 18 A. In addition, another elongated member assembly 18 C, comprised of elongated members 16 C and 16 D, is attached to the outlet 14 .
OPERATION
FIG. 6 —Sixth Embodiment
[0099] After passing by elongated member assembly 18 B (functionally virtually the same as elongated member assembly 18 A), the exhaust gasses are further altered by elongated member assembly 18 C. Elongated member assembly 18 C operates the same as elongated member assembly 18 A, but is attached to the outlet 14 , allowing the exhaust gasses to be further altered before exiting.
DETAILED DESCRIPTION
FIG. 7 —Seventh Embodiment
[0100] FIG. 7 shows the same elements as FIG. 1 , with an elongated member assembly 18 D, comprised of two elongated members 16 G and 16 H, in place of elongated member assembly 18 A. Elongated members 16 G and 16 H are both cylindrical in shape, open on both ends, and attached to the inlet 12 .
OPERATION
FIG. 7 —Seventh Embodiment
[0101] FIG. 7 operates the same as FIG. 1 , but elongated members 16 G and 16 H are cylindrical, which allows exhaust gasses to flow through the members as well as by them. This results in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 8 —EIGHT EMBODIMENT
[0102] FIG. 8 shows small cylindrical-bodied case 50 A, and an elongated member assembly 18 E, comprised of two elongated members 16 i and 16 J, attached to the inlet 12 . The elongated members 16 i and 16 J are both cylindrical in shape, open on both ends, and perforated. Another elongated member assembly 18 C is attached to the outlet 14 , and is comprised of elongated members 16 C and 16 D.
OPERATION
FIG. 8 —Eighth Embodiment
[0103] FIG. 8 operates the same as FIG. 6 , but with an elongated member assembly 18 E replacing FIG. 6 's elongated member assembly, 18 B. Perforation allows exhaust gasses to flow in and out of the cylindrical members. This results in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 9 —Ninth Embodiment
[0104] FIG. 9 shows the small cylindrical-bodied case 50 A, and elongated member assembly 18 E, comprised of elongated members 16 i and 16 J, attached to the inlet 12 . The elongated members 16 i and 16 J are both cylindrical in shape, open on both ends, and perforated.
OPERATION
FIG. 9 —Ninth Embodiment
[0105] FIG. 9 operates the same as FIG. 7 , but with elongated members 16 i and 16 J, which are both perforated and cylindrical. This allows exhaust gasses to flow in and out of the members, resulting in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 10 —Tenth Embodiment
[0106] FIG. 10 shows the small cylindrical-bodied case 50 A, and an elongated member assembly 18 F, comprised of two elongated members 16 K and 16 L, attached to a holding ring 28 A, which is in turn attached to the small cylindrical body 10 .
OPERATION
FIG. 10 —Tenth Embodiment
[0107] FIG. 10 operates the same as FIG. 1 , but instead of elongated members 16 A and 16 B, this embodiment uses elongated members 16 K and 16 L, attached to the holding ring 28 A, which in turn is attached to the small cylindrical body 10 . This results in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 11 —Eleventh Embodiment
[0108] FIG. 11 shows the same elements as FIG. 10 , with the addition of another elongated member assembly 18 J, comprised of two elongated members 16 W and 16 X, and a holding ring 28 B.
OPERATION
FIG. 11 —Eleventh Embodiment
[0109] FIG. 11 operates the same as FIG. 10 , but with a second elongated member assembly 18 J. This allows the exhaust gasses to be further manipulated, resulting in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 12 —Twelfth Embodiment
[0110] FIG. 12 shows the same elements as FIG. 1 , with the addition of another elongated member assembly 18 J, comprised of elongated members 16 W and 16 X, and the holding ring 28 B.
OPERATION
FIG. 12 —Twelfth Embodiment
[0111] FIG. 12 operates the same as FIG. 11 , but with one of the elongated member assemblies 18 A attached to the inlet 12 . This results in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 13 —Thirteenth Embodiment
[0112] FIG. 13 shows a plan view of an embodiment comprising of small cylindrical-bodied case 50 A, and an elongated member assembly 18 G, comprised of two elongated members 16 M and 16 N, attached inside the inlet 12 . Elongated members 16 M and 16 N are flat (technically polyhedral, as all physical objects have depth).
OPERATION
FIG. 13 —Thirteenth Embodiment
[0113] FIG. 13 operates the same as FIG. 1 , but with elongated member assembly 18 G in place of 18 A. This results in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 14 —Fourteenth Embodiment
[0114] FIG. 14 shows the same elements of FIG. 13 , with the addition of a body-mounted “v”-shaped deflection baffle 30 .
OPERATION
FIG. 14 —Fourteenth Embodiment
[0115] FIG. 14 operates the same as FIG. 13 , with the addition of body-mounted “v”-shaped deflection baffle 30 . Exhaust gasses are forced to go around the baffle, which slows down the flow, as well as creates noise canceling deflection between baffle 30 and the small cylindrical body 10 .
DETAILED DESCRIPTION
FIG. 15 —Fifteenth Embodiment
[0116] FIG. 15 shows the same elements as FIG. 13 , with the addition of sound absorbent material 32 (examples of sound absorbent materials include (but is not limited to) fiberglass packing and steel wool).
OPERATION
FIG. 15 —Fifteenth Embodiment
[0117] FIG. 15 operates the same as FIG. 13 , with the addition of sound absorbent material 32 . Some of the exhaust gasses are caught by the sound absorbent material 32 , which results in lower volume and altered tone quality.
DETAILED DESCRIPTION
FIG. 16 —Sixteenth Embodiment
[0118] FIG. 16 shows the same elements as FIG. 13 , with the addition of a third elongated member 16 o , which along with elongated members 16 M and 16 N, make up the elongated member assembly 18 H.
OPERATION
FIG. 16 —Sixteenth Embodiment
[0119] FIG. 16 operates the same as FIG. 13 , with the addition of a third elongated member 16 o . This results in different resonant frequencies than those produced by the embodiment illustrated in FIG. 13 .
DETAILED DESCRIPTION
FIG. 17 —Seventeenth Embodiment
[0120] FIG. 17 shows a plan view of an embodiment comprising of small cylindrical-bodied case 50 A, and the elongated members assembly 18 i (which is comprised of elongated members 16 P, 16 Q, 16 V, 16 R, 16 S, 16 T, and 16 U). Elongated members 16 R, 16 S, 16 T, and 16 U are referred to as “branches” because they stem from elongated members 16 P, 16 Q, and 16 V, respectively. Elongated member assembly 18 i is attached to the inlet 12 .
OPERATION
FIG. 17 —Seventeenth Embodiment
[0121] FIG. 17 operates the same as FIG. 1 , with elongated member assembly 18 i in the place of elongated member assembly 18 A. Elongated members 16 P, 16 Q, 16 R, 16 S, 16 T, and 16 U all interact with each other as exhaust gasses flow past them, resulting in a complex array of resonant frequencies.
DETAILED DESCRIPTION
FIG. 18 —Eighteenth Embodiment
[0122] FIG. 18 shows a large cylindrical-bodied case 50 B, comprised of a large cylindrical body 10 B, inlet 12 , and outlet 14 . An elongated member assembly 18 K, comprised of elongated members 16 Y and 16 AA, is attached inside the inlet 12 .
OPERATION
FIG. 18 —Eighteenth Embodiment
[0123] FIG. 18 operates the same as FIG. 1 , with elongated member assembly 18 K in the place of elongated member assembly 18 A, the large cylindrical-bodied case 50 B in the place of the small cylindrical-bodied case 50 A, and the large cylindrical body 10 B in the place of the small cylindrical body 10 A. The large case results in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 19 —Nineteenth Embodiment
[0124] FIG. 19 shows the same elements as FIG. 18 , with the addition of deflection baffle 20 .
OPERATION
FIG. 19 —Nineteenth Embodiment
[0125] FIG. 19 operates the same as FIG. 18 , with the addition of deflection baffle 20 . After passing the elongated member assembly 18 K, some of the exhaust gasses flow directly out, while some are forced to the sides of the deflection baffle 20 , where they deflect between the baffle 20 and large cylindrical body 10 B. This results in further noise cancellation. The gasses eventually flow out of the case 50 A via the outlet 14 .
DETAILED DESCRIPTION
FIG. 20 —Twentieth Embodiment
[0126] FIG. 20 shows the large cylindrical-bodied case 50 B, an elongated member assembly 18 L (comprised of elongated members 16 BB and 16 CC), and holding ring 28 C (which is attached to the large cylindrical body 10 B).
OPERATION
FIG. 20 —Twentieth Embodiment
[0127] FIG. 20 operates the same as FIG. 18 , but instead of elongated members 16 Y and 16 AA, this embodiment uses elongated members 16 BB and 16 CC, attached to the holding ring 28 C, which in turn is attached to the large cylindrical body 10 B. This results in different sound characteristics than those produced by other embodiments.
DETAILED DESCRIPTION
FIG. 21 —Twenty First Embodiment
[0128] FIG. 21 shows the large cylindrical-bodied case 50 B, an elongated member assembly 18 M (comprised of elongated members 16 DD, 16 EE, 16 FF, 16 GG, 16 HH, 16 ii , and holding ring 28 D). The elongated member assembly 18 M is attached to the body 10 B.
OPERATION
FIG. 21 —Twenty First Embodiment
[0129] After entering the large cylindrical body 10 B via the inlet 12 , the exhaust gasses flow into one of the three holes in holding ring 28 D. Inside each hole is a set of elongated members. As the exhaust gasses pass through the elongated members, they vibrate amongst each other, creating complex resonant frequencies. The exhaust gasses then exit through outlet 14 .
DETAILED DESCRIPTION
FIG. 22 AND FIG. 23 —Twenty Second Embodiment
[0130] FIG. 22 and FIG. 23 show the large cylindrical-bodied case 50 B, an elongated member assembly 18 N (comprised of elongated members 16 JJ and 16 KK and attached to the inlet 12 ). In addition, FIGS. 22 and 23 show a baffle assembly 34 , comprised of a baffle assembly front cradle 36 , baffle assembly holding ring 38 , perforated baffle 1 40 , perforated baffle 2 42 , and perforated baffle 3 44 .
OPERATION
FIG. 22 AND FIG. 23 —Twenty Second Embodiment
[0131] After passing by the elongated member assembly 18 N, the exhaust gasses flow into either perforated baffle 2 42 or perforated baffle 3 44 . From there the exhaust gas either flows out of the perforations, or travels to the end of their respective baffles before hitting the large cylindrical body 10 B, then turning around and flowing into perforated baffle 1 40 (this is possible because the baffle assembly holding ring 38 is open in its center). The exhaust gasses then exit through outlet 14 .
DETAILED DESCRIPTION
FIG. 24 —Twenty Third Embodiment
[0132] FIG. 24 shows a polyhedral-bodied case 50 C, comprised of a polyhedral body 10 C, inlet 12 , and outlet 14 . An elongated member assembly 18 K, comprised of elongated members 16 Y and 16 AA, is attached inside the inlet 12 .
OPERATION
FIG. 24 —Twenty Third Embodiment
[0133] FIG. 24 operates the same as FIG. 18 , with polyhedral-bodied case 50 C in place of the large cylindrical-bodied case 50 B.
DETAILED DESCRIPTION
FIG. 25 —Twenty Fourth Embodiment
[0134] FIG. 25 shows the same elements as FIG. 18 , with elongated member assembly 18 M in place of elongated member assembly 18 K. Elongated member assembly 18 M is comprised of elongated members 16 LL and 16 MM, which are both curved.
OPERATION
FIG. 25 —Twenty Fourth Embodiment
[0135] FIG. 25 operates the same as FIG. 18 , with elongated member assembly 18 M in place of elongated member assembly 18 K. Because the members comprising elongated member assembly 18 K are curved, different sounds are created in comparison to other embodiments.
CONCLUSIONS, RAMIFICATIONS, AND SCOPE
[0136] Accordingly, the reader will see that resonance generating mufflers of the various embodiments are capable of generating tones that are noise canceling and/or sound enhancing. These mufflers are capable of extremely low back pressure, even when used to silence, and are capable of extraordinarily pleasing tones when used to enhance engine sound. Furthermore, a resonance generating muffler has additional advantages such as:
Providing a crisp, natural tone. A lack of annoying low frequency “drone”. The potential to reduce or eliminate popping exhaust sounds. The potential to specifically reduce unpleasant tones without sounding dull and artificial. The ability to solve the problem of high back pressure (and its consequential reduction of efficiency) in mufflers intended to silence.
[0142] Although the above description provides many specificities, they should not be construed as limiting the scope of the invention or its embodiments. Rather, these specificities should be seen merely as examples of what is possible under the claims. Many other variations are possible as well. For example, any body shape may be used. In addition, any number of elongated members may be used, in any combination or form, as long as they fall under the description in the claims. Any combination of sound baffles, sound absorbent material, and/or other sound altering devices (for example, active electronic noise canceling) may be used in addition to the members, providing such implementation is legal under intellectual property law.
[0143] Accordingly, scope should be determined not by the examples given, but by the appended claims and their legal equivalents.
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In accordance with at least one embodiment: a muffler with a case (comprised of at least one inlet, at least one outlet, and a body), and elongated members comprised of material capable of a predetermined resonance. The elongated members have sufficient length after their final point of attachment to vibrate when exposed to flowing exhaust gasses. This vibration results in resonance that is noise canceling and/or sound enhancing. The muffler may also contain any combination of sound baffles, sound absorbent material, and other sound altering devices.
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BACKGROUND OF THE INVENTION
[0001] Certain embodiments of the present invention relate to reducing forces transmitted from one structure to another. More particularly, certain embodiments of the present invention relate to reducing forces transmitted to a diagnostic medical system during shipment.
[0002] Diagnostic medical systems, such as a diagnostic X-ray system having a large C-arm, are complex, large, heavy, and expensive systems that need to be protected from damage due to shock and vibration during shipment. Units are typically shipped all around the world in vehicles experiencing various road conditions.
[0003] Various packaging systems and methods have been used in shipping medical systems. For example, one method includes mounting the medical system directly onto a wooden base with the chassis of the system elevated and supported on wooden strips. Another method includes sandwiching expanded polyurethane (EP) foam between two layers of plywood and mounting the system on the top layer. The two methods typically do not provide the required isolation from shock and vibration. Other methods include using a high-density polyethylene (HDPE) pallet with the system mounted on the pallet. The tooling cost and per unit production cost of the HDPE pallet often prove to be prohibitive, however.
[0004] Some methods include using relatively sophisticated isolators incorporated into relatively sophisticated configurations. For example, a method described in U.S. Pat. No. 5,808,866 to Porter describes having isolators mounted between a case and a card cage within the case. U.S. Pat. No. 5,149,066 Snaith, et al. describes an isolator having a plurality of arched elements arranged circumferentially about an axis between two structures. U.S. Pat. No. 4,269,400 to Jensen describes an isolator having a plurality of concentrically-arranged, nested, bell-shaped components stacked in parallel about a common axis. U.S. Pat. No. 4,783,038 to Gilbert, et al. describes an isolator with flexural support element pairs being located and offset in planes at acute angles from the horizontal defined by a base means.
[0005] The methods and systems described above tend to be complex, expensive, and/or inadequate for reducing shock and vibration. For example, the isolators described above have multiple damping elements arranged in complex configurations.
[0006] A need exists for a simple damper with a single damping element capable of providing resistance to shock and vibration forces in multiple orthogonal spatial directions. A need also exists for a relatively simple packaging system that uses a plurality of the simple dampers in a simple configuration.
SUMMARY OF INVENTION
[0007] An embodiment of the present invention provides for a packaging system for reducing transmission of force from a base platform to a floating platform by employing a plurality of dampers mounted between the base platform and the floating platform. The dampers each comprise a single damping element having at least two contact arms affixed to either the base platform or the floating platform. A plurality of side panels attach to the base platform to enclose equipment that is mounted to the floating platform.
[0008] Apparatus is provided for reducing transmission of force from a base structure to a supported structure. The apparatus comprises a single damping element having at least two contact arms affixed to either the base structure or the supported structure. An affixing base plate is mounted between the damping element and the base structure and an affixing offset plate is mounted between the damping element and the supported structure. The single damping element provides resistance to force in multiple orthogonal spatial directions.
[0009] A method is also provided for reducing transmission of force from a base structure to a supported structure. The method includes mounting a plurality of dampers between the base structure and the supported structure. The dampers each include a single damping element having at least two contact arms affixed to either the base structure or the supported structure. The base structure is mounted to a transportation vehicle. The supported structure includes a diagnostic medical system mounted on a floating platform.
[0010] Certain embodiments of the present invention afford an approach to providing resistance to shock and vibration forces in multiple orthogonal spatial directions using simple dampers each having a single damping element. Certain embodiments also provide for a relatively simple packaging system that uses a plurality of the simple dampers in a simple configuration.
BRIEF DESCRIPTION OF DRAWINGS
[0011] [0011]FIG. 1 is an isometric drawing of a damper having a single damping element in accordance with an embodiment of the present invention.
[0012] [0012]FIG. 2 is a top perspective view of a double-X damping element in accordance with an embodiment of the present invention.
[0013] [0013]FIG. 3 illustrates the method of mounting a diagnostic medical system on a floating platform by employing a plurality of the dampers of FIG. 1 in accordance with an embodiment of the present invention.
[0014] [0014]FIGS. 4 a , 4 b , and 4 c illustrate several views of a simple configuration of a plurality of the dampers of FIG. 1 arranged between a base platform and a floating platform in accordance with an embodiment of the present invention.
[0015] [0015]FIG. 5 illustrates a packaging system employing a plurality of the dampers of FIG. 1 in accordance with an embodiment of the present invention.
[0016] The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.
DETAILED DESCRIPTION
[0017] [0017]FIG. 1 is an isometric view of a damper 10 showing certain elements of the damper 10 in accordance with one embodiment of the present invention. The damper 10 comprises a base plate 30 , an offset plate 20 , and a single damping element 40 . The single damping element 40 is a single molded piece of rubber having four contact arms 50 , 60 , 70 , 80 forming a three-dimensional X shape in one embodiment of the present invention.
[0018] The two lower contact arms 70 and 80 connect to the base plate 30 and the two upper contact arms 50 and 60 connect to the offset plate 20 . The base plate 30 and the offset plate 20 are made of steel in one embodiment of the present invention. A chemlac bonding process may be used to bond the contact arms 50 - 80 of the rubber damping element 40 to the steel base plate 30 and steel offset plate 20 .
[0019] The base plate 30 and the offset plate 20 each have a through-hole 90 and 100 , respectively. The through-holes 90 and 100 may be used to bolt the damper 10 between a base platform and a floating platform of a packaging system. When mounted between two platforms, the damper 10 reduces transmission of shock and vibration forces in all three orthogonal spatial directions x, y, and z as shown in FIG. 1.
[0020] The rubber contact arms 50 - 80 of the damping element 40 allow the transmission of force to be reduced from the base plate 30 to the offset plate 20 by flexing when force is applied to the base plate from an external source. The X-shape and the rubber material of the damping element 40 provide flexure between the base plate 30 and offset plate 20 in all three spatial directions x, y, and z. The density and thickness of the rubber material of the damping element 40 determine the amount of flexure (resistance to force) provided by a single damper 10 .
[0021] Some typical specifications that are met by the X-damper design are shown in Table 1. The packaging system is designed such that the permissible shock values are limited within that shown in Table 1. Shock values that exceed the specifications are damped by the packaging system. The specifications in Table 1 are representative of the shock forces permissible, as per the GMTC (Global Mechanical Technology Center) standards, by the equipment within the packaging system when on a truck making a 2000 km trip. [t 1 ]
TABLE 1 ½sine wave shock pulses (representing a 2000 Km trip by truck) Duration Amplitude Number of (Milliseconds) (m/s 2 ) [g] Occurrences 7.5 96.1 [9.8] 324 12.5 39.2 [4.0] 216 17.5 32.4 [3.3] 162 22.5 25.5 [2.6] 135 27.5 16.7 [1.7] 81
[0022] More specifically, the dimensions of one embodiment of the X-shaped damper 10 are set based on shipping a medical diagnostic X-ray system with a large C-arm and meeting the specifications of Table 1. The height of the damper along the z direction, including the base plate 30 and offset plate 20 , is 100 millimeters, the length along the x direction is 110 millimeters, and the width along the y direction is 70 millimeters. The thickness of the steel base plate 30 and offset plate 20 are each 10 millimeters. The rubber material of the single damper is as follows: Specification of the rubber:
Material: Natural Rubber (No synthetic Variables, Re- Cyclable) Service Temp: 70° C. Hardness: 80 Shore A Specific Gravity: 0.83 Tensile Strength: 22 MP
[0023] Other materials may be used for the damping element 40 to achieve various levels of flexure and, therefore, damping for various combinations of density and thickness of the other materials. Materials and dimensions of the damping element may be customized for different equipment having various weights and centers of gravity.
[0024] The fact that the damping element 40 is a single molded piece having a relatively simple shape makes it easy to manufacture and keeps molding and per unit costs down. Of course, other shapes may be configured for the single damping element. For example, FIG. 2 shows a top view of a double-X configuration, having one X crossing orthogonally through another X, manufactured as a single piece. As a result, four contact arms 51 , 52 , 61 , and 62 extend from above the center intersection 55 of the double-X and four contact arms (not shown) extend from below the center intersection 55 of the double-X. The double-X configuration may potentially allow more similar damping to be provided along the x and y directions.
[0025] [0025]FIG. 3 illustrates the method of mounting a diagnostic medical system on a floating platform by employing a plurality of the dampers of FIG. 1 in accordance with an embodiment of the present invention. A diagnostic medical system 140 is mounted on top of a floating platform 110 . A plurality of X-shaped dampers 130 - 133 are shown being mounted between the floating platform 110 and the base platform 120 . The dampers are typically bolted to the floating platform and base platform. Various attachment methods may be used to secure the system 140 to the floating platform 110 , such as employing brackets and mounting screws, depending on the configuration of the system 140 .
[0026] [0026]FIGS. 4 a , 4 b , and 4 c show various views of a typical damper configuration between a base platform 120 and a floating platform 110 . In this example, eight dampers 130 - 137 are configured in a rectangular, symmetrical pattern. The base plates of the dampers are bolted to the base platform and the offset plates of the dampers are bolted to the floating platform. Any forces that are experienced by the base platform are damped by the dampers and, therefore, the floating platform experiences less force than that experienced by the base platform. As a result, equipment that is mounted to the floating platform is protected from the full force applied to the base platform.
[0027] [0027]FIG. 5 is a three-dimensional view of a packaging system 200 , illustrating how a diagnostic medical system 140 may be packaged using the damper concept. The medical system 140 is mounted to the floating platform 110 . The dampers ( 134 - 137 are shown in this view) are mounted between the floating platform 110 and the base platform 120 . Side panels 150 are mounted around the base platform 120 to enclose the medical system 140 on the floating platform 110 . When the medical system 140 is shipped, the base platform 120 may be mounted to the floor of a shipping vehicle such as a truck. In one embodiment of the present invention, the specifications of Table 1 are met. When the base platform 120 experiences the g-forces expected on a 2000 Km road trip, the diagnostic medical X-ray system 140 with its large C-arm 141 may not experience shock values that exceed the specification of Table 1.
[0028] As a comparison to other methods of damping, a 70 km road test was performed for three designs. The first design uses the expanded polyurethane (EP) foam, the second design uses a HDPE pallet, and the third design uses the X-shaped dampers. During the 70 km road test, the number of force events over 1.5 g experienced by the diagnostic medical system were measured. The EP foam design experienced 16 events, the HDPE design experienced 7 events, and the X-shaped damper design experienced zero events clearly illustrating the superior damping performance of the X-shaped damper design.
[0029] As an alternative, other configurations of dampers may be used depending on the weight and center of gravity of the equipment to be shipped. For example, a circular configuration of dampers may provide better overall damping for equipment where the weight is distributed mostly along the outer perimeter of the equipment. As a further alternative, dampers of differing designs may be employed in a single shipping configuration. For example, in the rectangular configuration of FIG. 4 a , dampers 130 , 131 , 134 , and 135 may be X-shaped, and dampers 132 , 133 , 136 , and 137 may be double-X shaped. As a result, the damping of forces experienced by the front half of the packaging system (corresponding to dampers 132 , 133 , 136 , and 137 ) may be more uniform in the x and y-directions. The damping of forces experienced by the back half of the packaging system (corresponding to dampers 130 , 131 , 134 , and 135 ) may be greater in the x-direction and less in the y-direction. Such a configuration may be desirable for certain types of equipment to be shipped.
[0030] In summary, the advantages and features include, among others, providing a simple damper with a single damping element capable of providing resistance to forces in multiple orthogonal spatial directions and a relatively simple packaging system that uses a plurality of the simple dampers in a simple, low cost configuration.
[0031] While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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A method and apparatus are disclosed for reducing transmission of force from a base structure to a supported structure. The method includes mounting a plurality of dampers between the base structure and the supported structure. Each damper includes a single damping element having at least two contact arms affixed to either the base structure or the supported structure. Damping of forces is achieved by each damper in multiple orthogonal directions. The base structure is mounted to a transportation vehicle. The supported structure includes equipment mounted on a floating platform.
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BACKGROUND OF THE INVENTION
The present invention relates generally to storage containers and more particularly, storage containers that are used to store computer disks or compact discs.
DESCRIPTION OF THE PRIOR ART
Computer disks, which are used to store digital information, typically are available in two widely accepted sizes: five and one-quarter inch and three and one-half inch. In addition, digital information is encoded on compact discs. Computer disks and compact discs hold vast amounts of digital data. Computer programmers often store computer disks and compact discs in plastic molded cases or in specially designed trays that hold either one or both sizes of the computer disks and/or the compact discs. Examples /f cases or trays for holding computer disks can be found in patents issued to O. Urban, et al., U.S. Pat. No. 5,022,516; S. Ferraroni, U.S. Pat. No. 4,776,457; R. Press, U.S. Pat. No. 4,776,463; B. Nemeth, U.S. Pat. No. 4,735,309; and A. Northrup et al., U.S. Pat. No. 4,640,416. The disadvantage with these types of cases and trays is that they do not contain separate enclosures or storage areas for holding the handwritten, typed or printed hard copy of instructions or code ("documentation") relating to such computer disks or compact discs.
In order to overcome the disadvantage cited with respect to conventional cases or trays, the computer disks or compact discs are sometimes stored together with the documentation by placing such computer disks or compact discs in flexible, loose-leaf vinyl plastic pages that are punched with holes for placement in a ring-type notebook binder. Software programmers and others then type or print the computer documentation on loose-leaf paper pages and place them in the ringed binder. A disadvantage of storing computer disks or compact discs with the documentation in this manner is that commercially available flexible, loose-leaf vinyl plastic pages used to hold computer disks or compact discs are not constructed in a manner which prevents the computer disks or compact discs from falling out should the ringed binder be inadvertently turned sideways or inverted. The impact and contact of the computer disk or compact disc with a surface containing foreign particles or contaminants could result in the destruction of all or portions of the digitally encoded information on such fragile computer disk or compact disc.
Two examples of rigid plastic pages, as opposed to flexible, vinyl plastic page, for holding computer disks which overcomes the disadvantage reference above can be found in R. Rose, U.S. Pat. No. 4,957,205 and J. Cohen, U.S. Pat. No. 4,928,828. These two patents illustrate rigid plastic pages with snap mechanisms which retain computer disks firmly in place should the ringed binder in which they are placed be turned sideways or inverted. An example of a notebook for storage of computer disks and loose-leaf documentation which also overcomes the disadvantage can be found in R. Rose, U.S. Pat. No. 4,765,462. This patent illustrates a notebook with a ring assembly which has incorporated therein a ridged portion in the bottom wall thereof in which a computer disk of a predetermined size can be inserted. The ridge assembly serves to retain the computer disk in place. However, the structure of the ridge in this notebook restricts the number of computer disks that can be inserted therein. In addition, the above referenced examples of the rigid plastic pages and the ridged notebook do not overcome another disadvantage inherent in using a ringed binder to hold both documentation and computer disks or compact discs. That disadvantage is that the documentation must be punched with holes that conform to the number of rings and spacing of rings in the ringed binder. Most commercially available software is accompanied with bound documentation which is often of a thickness which is not easily adaptable to being punched with holes for placement in a ringed binder. This problem is exacerbated because software publishers often package software and bound documentation in paperboard boxes which deteriorate. In the event the original package comes apart, users of such commercially available software are not able to avail themselves of the ringed binder as a method to store the computer disk or compact disc with the bound documentation. Therefore, such users often resort to storing the computer disks or compact discs in cases or trays such as those referenced above, apart from the bound documentation. Even if the documentation which accompanies the software is easily adaptable to the ringed binder cited herein, it may still become detached from the binder if it should tear at the punched holes.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a storage container which, when closed, provides two separate enclosures, the first of which contains storage space for bound or unbound documentation, the second of which serves as a shell of additional protection for computer disks or compact discs which are inserted in flexible, vinyl plastic pages or pockets.
In a preferred embodiment, the integral, molded plastic storage container consists of four hingedly connected walls, with four side walls molded perpendicular to the inner, planar surface of a bottom wall. An interior wall is hingedly connected to the top edge of the side wall near the right side edge of the bottom 7all. The front edge and the back edge of the interior wall fit just within the side walls proximate the front edge and the back edge, respectively, of the bottom wall such that when the inner, planar surface of the hinged, interior wall is moved into a facing relationship with the inner, planar surface of the bottom wall, the bottom, interior, and side walls form an enclosure for holding bound or unbound documentation. A rear wall (spine) is hingedly connected to the left side edge of the bottom wall. The right side edge of a top wall is hingedly connected to the left side edge of the spine. A side wall is molded perpendicular to the inner, planar surface of the top wall near the left side edge of the top wall.
Attached to the inner, planar surface of the top wall are several flexible, loose-leaf type, vinyl plastic pages containing recess or pockets of varying dimensions. The pockets can be used to store computer diskettes, compact discs, program templates, quick reference cards and other related material. A clear, one-layer, vinyl plastic sheet covers is fused to the edges of the top, rear and bottom walls so as to create a pocket between the inner surface of the plastic sheet and the container. Title pages or other printed or written matter describing the contents of the container can be inserted, and clearly seen, in such pocket.
An advantage of the storage container of the present invention is that it provides two enclosures inside one storage container. One enclosure is for bound or unbound documentation related to software and the second enclosure for protection of computer disk or compact discs inserted in vinyl plastic pages. In such manner, the bound or unbound computer documentation can be stored in close proximity to the related computer disks or compact discs.
Another advantage of the storage container of the present invention is that when the storage container is in the closed and latched position, the storage container provides a sealed, dust-free environment which prevents the computer disks or compact discs and documentation from falling out should the storage container be turned sideways or inverted.
Another advantage of the present invention is that it is fabricated substantially from plastic material in an injection plastic molding process so as to facilitate manufacturing.
These and other objects and advantages of the present invention will become apparent following a reading of the following detailed description of the preferred embodiments which are illustrated in the several figures of the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following drawings which form a part of the Specification and are to be read in conjunction therewith and in which like reference numerals are to be used to indicate like parts in the various views:
FIG. 1 is a perspective view of a molded plastic, hinged, storage container in accordance with the present invention for computer disks or compact discs, templates and related documentation shown in the open position. The container is shown without the software or documentation;
FIG. 2 is a top plan view of the storage container shown in FIG. 1 in a fully open position;
FIG. 3 is a view similar to that shown in FIG. 2 illustrating the opposite surface of the storage container in a fully open position;
FIG. 4 is a partial cross section side view of the storage container, illustrating the back aligning ridge integrally molded to the inner, planar surface of the top wall and the upper edges of a stack of flexible, vinyl plastic pages attached to the top wall with one of the rivets;
FIG. 5 is a partial cross section side view of the storage container, illustrating the front aligning ridge integrally molded to the top wall and the lower edges of a stack of flexible, vinyl plastic pages. The female portion of the snap attached to the covering vinyl plastic sheet is shown unsnapped from the male portion of the snap which protrudes through the top wall;
FIG. 6 is a cut-away side elevational view of the storage container shown in FIG. 1, illustrating the two enclosures that are formed when it is in the fully closed and latched position;
FIG. 7 is a view of the storage container of FIG. 1, shown from a side elevational view, in a fully open position;
FIG. 8 is a view of a clear, flexible, vinyl plastic page holding 5.25 inch computer disks, with two holes near the upper edge through which the page is to be attached to the storage container shown in FIG. 1 with rivets;
FIG. 9 is a front elevational view of the storage container shown in FIG. 1; and
FIG. 10 is a view of the inner, planar surface of the top wall of an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the storage container of the present invention for storing computer disks or compact discs and documentation is illustrated in perspective view in FIG. 1 and is designated generally by the numeral 10. As shown therein, the storage container 10 is in the nature of a hinged enclosure. The container 10 includes a bottom wall 12 which has an inner, planar surface 13, a front edge 14, an opposed back edge 15 (seen in FIG. 2), a left side edge 16 and an opposed right side edge 17. Rigidly molded around the inner, planar surface 13 of the bottom wall 12 near the front edge 14, the left side edge 16, the back edge 15 and the right side edge 17, are four side walls extending from, and perpendicular with, the inner, planar surface 13.
A front side wall 18 is near, and parallel to, the front edge 14 of the bottom wall 12.
A back side wall 19 is near, and parallel to, the back edge 15 of the bottom wall 12 and is opposed from the front side wall 18. As illustrated in FIG. 9, the back side wall 19 is the same height as the front side wall 18.
A left side wall 20 is near, and parallel to, the left side edge 16 and is connected to the front side wall 18 and the back side wall 19. The left side wall 20 is about two-thirds the height of the front side wall 18 and the back side wall 19. As can be seen in FIG. 7, integrally molded as part of the left side wall 20 is a hingedly connected internal latch 21. As illustrated in FIG. 6, there is sufficient space between an outer surface 22 of the left side wall 20 and an inner, planar surface 23 of a rear 7all 24 (seen in FIG. 2), such that when the storage container 10 is in the latched and closed position, clearance is provided for an overhanging right side edge 25 of an interior wall 26 and to provide clearance for the internal latch 21.
A right side wall 27 is near the right side edge 17 and is connected to front side wall 18 and the back side wall 19. The right side wall 27 is opposed from the left side wall 20. The right side wall 27 is the same height as the left side wall 20. Integrally molded along a top edge 28 of the right side wall 27 is the interior wall 26.
Referring to FIG. 1, a back rib 29 is integrally molded into an inner, planar surface 30 of the back side wall 19. Referring to FIG. 9, a front rib 31 is integrally molded into an inner, planar surface 32 of the front side wall 18. The top of the front rib 31 is level with the top edge 28 (seen in FIG. 1) /f the right side wall 27 and a top edge 33 (seen in FIG. 7) of the left side wall 20. When an inner, planar surface 34 of the interior wall 26 is brought into a facing relationship with the inner, planar surface 13 of the bottom wall 12, a back edge 35 of the interior wall 26 is supported by the back rib 29 and a front edge 36 of the interior wall 26 is supported by the front rib 31 as seen in FIG. 6.
The preferred embodiment of the present invention includes a notch 37 in the interior wall 26 centered between the front edge 36 and the back edge 35 near a left side edge 39 as seen FIG. 2. The outline of the notch 37 matches the outline of a recess 40 when the inner, planar surface 34 of the interior wall 26 is moved into a facing relationship with the inner, planar surface 13 of the bottom wall 12. This allows an external catch 41 to clear the left side edge 39 of the interior wall 26 and rest in the recess 40 as seen in FIG. 6.
The internal latching mechanism consists of the hingedly attached internal latch 21 (seen in FIG. 6) and an internal catch 42 (seen in FIG. 1). The internal latch 21 is hingedly molded to the outer surface 22 of the left side wall 20. The longitudinal center line of the internal latch 21 is an equal distance from the back side wall 19 and the front side wall 18. The internal catch 42 is rigidly molded to, and is perpendicular with the inner, planar surface 34 near the right side edge 25 of the interior wall 26. The longitudinal center line of the internal catch 42 is an equal distance from the back edge 35 of the interior wall 26 and the front edge 36 of the interior wall 26. When the inner, planar surface 34 of the interior wall 26 is moved into a facing relationship with the inner, planar surface 13 of the bottom wall 12, the internal catch 42 comes to rest in a recess 43 of the left side wall 20.
Referring to FIG. 2 and FIG. 3, the rear wall 24 serves as the spine of the storage container 10. The rear wall 24 has a front edge 44, an opposed back edge 45, a ]eft side edge 46 and an opposed right side edge 47. Referring to FIG. 1, the distance from the left side edge 46 to the right side 47 across the front edge 44 of the rear wall 24 is equal to the distance from the inner, planar surface 13 of the bottom wall 12 beginning near the base of the front side wall 18 to a top edge 48 of the front side wall 18, such that when the inner, planar surface 23 of the rear wall 24 is moved into a facing relationship with the outer surface 22 of the left side wall 20, the left side edge 46 of the rear wall 24 is even with the top edge 48 of the front side wall 18. The left side edge 16 of the bottom wall 12 is hingedly connected to the right side edge 47 of the rear wall 24. The left side edge 46 of the rear wall 24 is hingedly connected to a right side edge 49 of a top wall 50.
The top wall 50 is the final wall that is moved in order to fully enclose the storage container 10. The top wall 50 has an inner, planar surface 51, a front edge 52, an opposed back edge 53, the right side edge 49 and an opposed left side edge 54. A side wall 55, which is near, and parallel to, the left side edge 54 extends from, and is perpendicular with, the inner, planar surface 51. The side wall 55 is rigidly molded to the inner, planar surface 51. When viewed in the fully open position illustrated in FIG. 7, the side wall 55 is about one-third the height of the front side wall 18.
Referring to FIG. 2, a front aligning ridge 56 and a back aligning ridge 57 are rigidly molded to the inner, planar surface 51 of the top wall 50. Referring to FIG. 9, the back aligning ridge 57 is just inside the inner, planar surface 30 of the back side wall 19 and the front aligning ridge 56 is just inside the inner, planar surface 32 of the front side wall 18 when the storage container 10 is in the closed position. The back aligning ridge 57 and the front aligning ridge 56 serve to keep the back side wall 19 and the front side wall 18 from flexing inward should inward pressure be applied to the back side wall 19 or the front side wall 18. The aligning ridges also prevent any material or software that may have dislodged in the second, outer enclosure of the storage container from slipping out between a top edge 58 of the back side wall 19 or the top edge 48 of the front side wall 18 and the inner, planar surface 51 of the top wall 50.
Referring to FIG. 1, a front paired aligning ridges 59 are formed on the inner, planar surface 23 near, and parallel to, the front edge 44 of the rear wall 24. A back paired aligning ridges 60 are formed on the inner, planar surface 23 near, and parallel to, the back edge 45 of the rear wall 24. The front paired aligning ridges 59 and the back paired aligning ridges 60 serve to guide the rear wall 24 into position perpendicular to the bottom wall 12, for latching when the storage container 10 is closed.
Referring to FIG. 6, a peg 61 is rigidly formed on, and extends away from, the top edge 48 of the front side wall 18. The peg 61 mates in an aperture 62 which is cut through the top wall 50 when the storage container 10 is closed. Referring to FIG. 1, a peg 63 is rigidly formed on, and extends away from, the top edge 58 of the back side wall 19. The peg 63 mates in an aperture 64 which is cut through the top wall 50 when the storage container 10 is closed. The mating of each of the pegs in each of the apertures serves to keep the rear wall 24 perpendicular with the bottom wall 12 and the top wall 50 when the storage container 10 is in the closed and latched position.
Referring to FIG. 1, flexible vinyl plastic pages 65 are fastened to the inner, planar surface 51 of the top wall 50, just inside the back aligning ridge 57, with two rivets 66. The flexible vinyl plastic pages 65 are made of vinyl with anti-static characteristics. The two rivets 66 can be constructed of either metal or plastic. One of the two rivets 66 is located near the left side edge 54. The other of the two rivets 66 is located near the right side edge 49. Referring to FIG. 4, a cover sheet 67 serves as a cover for the flexible vinyl plastic pages 65. Each of the flexible vinyl plastic pages 65 underlying the cover sheet 67 is constructed of two or more sheets of overlaying vinyl plastic which are fused together to form pockets or recesses suitable for holding computer disks, compact disks and templates or other related material. FIG. 8 illustrates one of the flexible vinyl plastic pages 65 holding five and one-half inch computer disks. Depending upon the use of the storage container 10, additional or fewer flexible vinyl plastic pages 65 may be attached to the inner, planar surface 51 of the top wall 50 in the assembly process.
The cover sheet 67 has embedded in the lower, centered portion thereof a female portion 68 of a snap 69 which engages with a male portion 70 of the snap 69 which protrudes through the inner, planar surface 51 of the top wall 50. Referring to FIG. 5, the male portion 70 of the snap 69, constructed of metal or plastic, is attached to the top wall 50 and protrudes through the inner, planar surface 51 of the top wall 50. The female portion 68 is embedded through the cover sheet 67. Referring to FIG. 2, the snap 69 is located about equal distance between the left side edge 54 and the right side edge 49 of the top wall 50 just inside the front aligning ridge 56.
Referring to FIG. 1 and FIG. 9, the external latching mechanism consists of the external catch 41 and a hingedly connected external latch 71. The external catch 41 is rigidly molded to the side wall 55. The longitudinal center line of the external catch 41 is an equal distance from a back edge 72 of the side wall 55 and a front edge 73 of the side wall 55. The longitudinal center line of the external latch 71 is an equal distance from the back edge 72 of the side wall 55 and the front edge 73 of the side wall 55 when the inner, planar surface 51 of the top wall 50 is moved into a facing relationship with an outer, planar surface 74 of the interior wall 26 and the external catch 41 comes to rest in the recess 40 of the right side wall 27. The external latch 71 is integrally molded to an outer, planar surface 75 of the right side wall 27 as illustrated in FIG. 9. Pressure on the outside surface of the external latch 71 will cause an inverted L molded to the inner surface of the external latch 71, to come into contact with an external catch inverted L 76 on the external catch 41. The terminating end of the inverted L on the external latch lies slightly below the terminating end of the external catch inverted L 76 when the two are in contact. When the external latch 71 comes into contact with the external catch 41, pressure is required on the outer surface of the external latch 71 to force the terminating end of the inverted L on the external latch 71 to snap into a locked position over the terminating end of the external catch inverted L 76. Pressure applied underneath the inner surface of the external latch 71 forces the terminating end of the inverted L on the external latch 71 in the opposite direction, eventually forcing the terminating end of the inverted L on the external latch 71 to flex and snap over the terminating end of the external catch inverted L 76. The internal latching mechanism consists of the internal latch 21, the internal catch 42, an inverted L 77 of the internal catch 42 and a corresponding inverted L on the internal latch 21. The internal latch 21 and the internal catch 42 interface in the same manner as the outside latching mechanism. The external catch inverted L 76 and the corresponding inverted L on the external latch 71 are each integrally molded to the inner surfaces of the external catch 41 and the external latch 71, respectively, of a resilient material thick enough to withstand continual latching and unlatching. However, the terminating end of the external catch inverted L 76 and the corresponding terminating end of the inverted L on the external latch 71 are semi-flexible to allow latching and unlatching of the storage container 10 without undue pressure.
Referring to FIG. 2, the boundary where the right side edge 49 of the top wall 50 and the left side edge 46 of the rear wall 24 converge is a hinge 78. The boundary where the right side edge 47 of the rear wall 24 and the left side edge 16 of the bottom wall 12 converge is a hinge 79. The boundary where the top edge 28 of the right side wall 27 and the left side edge 39 of the interior wall 26 converge is a hinge 80. The boundary where the internal latch 21 converges with the left side wall 20 is a hinge 81. The boundary where the external latch 71 converges with the right side wall 27 is a hinge 82. The hinges (commonly referred to as "living" hinges) are each formed of a resilient material and are thick enough to provide the strength required to withstand continual flexing due to closure of the storage container 10 and latching thereof.
As seen in FIG. 3, a clear vinyl plastic sheet 83 covers the outer, planar surface of the top wall 50, the rear wall 24 and the bottom wall 12. The clear vinyl plastic sheet 83 is pulled taut and fused to the molded plastic storage container 10 continuously along the left side edge 54 and the front edge 52 of the top wall 50, the front edge 44 of the rear wall 24, and the front edge 14 and the right side edge 17 of the bottom wall 12. The clear vinyl plastic sheet 83 is not fused to the storage container 10 along the back edge 53 of the top wall 50, the back edge 45 of the rear wall 24 or the back edge 15 of the bottom wall 12. In this manner a pocket is created between the inner surface of the clear vinyl plastic sheet 83 and the outer, planar surface of the top wall 50, the outer, planar surface of the rear wall 24 and the outer, planar surface of the bottom wall 12, in which can be placed title pages or other printed or written matter describing the contents of the plastic container 10.
Referring to FIG. 10, another embodiment is illustrated. In this embodiment computer disks and compact disks are stored in pockets between the inner, planar surface 51 of the top wall 50 and the inner, planar surface of the clear vinyl plastic sheet 83, which is fused to the inner, planar surface 51 of the top wall 50 in a manner so as to form pockets suitable for storing computer disks and compact discs. In such embodiment, neither rivets nor a snap are utilized.
Except for the flexible vinyl plastic pages 65 which hold the computer disks, compact disks, the clear vinyl plastic sheet 83 fused to outer, planar surfaces of the storage container 10 and the two rivets 66 and the snap 69 (in the preferred embodiment), the storage container 10 is made from a plastic resin in a plastic injection molding process. The use of plastic resin allows each of the hinges to be integrally molded with the top wall 50, the rear wall 24, the bottom wall ]2, the interior wall 26 and the latching mechanisms. The only additional manufacturing steps required are fusing the clear vinyl plastic sheet 83 around the outer, planar surface of the top wall 50, the outer, planar surface of the rear wall 24 and the outer, planar surface of the bottom wall 12, as described herein, and manufacturing the flexible vinyl plastic pages 65 and assembling the flexible vinyl plastic pages 65 to the inner, planar surface 51 of the top wall 50 with the two rivets 66, and attaching the male portion 70 of the snap 69 through the top wall 50 and the female portion 68 of the snap 69 through the cover sheet 67. In the alternative embodiment, which does not use the two rivets 66 and the snap 69, the additional manufacturing step, in lieu of assembling the flexible vinyl plastic pages 65 to the inner, planar surface 51 of the top wall 50 with the snap 69 and the two rivets 66, is fusing the vinyl plastic sheet to the inner, planar surface 51 of the top wall 50.
The terms "front", "back", "left", "right", "rear", "bottom", "top", "inner", "outer", "interior" and "side" and words of similar import as used herein are intended to apply only to the position of the parts as illustrated in the drawing, since it is well known that storage containers of the general type illustrated may be oriented in many positions.
While the invention has been particularly shown and described with certain preferred embodiments, it will be understood by those skilled in the art that various alterations and modifications in form and detail may be made therein. Accordingly, it is intended that the following claims cover all such alterations and modifications as fall within the true spirit and scope of the invention.
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An injection molded storage container is provided which is formed with three covers or walls and a spine for storing magnetic media and documentation. Two living hinges on either side of the spine are connected to the edges of the first wall and the second wall, respectively. Two sets of opposed sidewalls, molded to and perpendicular from the first wall, are connected to form a recess for holding documentation. A third wall is hinged to the top of the opposed sidewall which is parallel to and furthest from the spine. The third wall is sized to fit within the first set of opposed sidewalls. The inner surfaces of the first wall, third wall and opposed sidewalls form an interior enclosure. Vinyl pages for holding magnetic media are attached to the inner surface of the second wall. The second wall and spine fold over the interior enclosure.
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BACKGROUND OF THE INVENTION
i. Field of the Invention
This invention relates to an electrolysis system including an electrolytic cell of the diaphragm-type particularly suitable for the production of chlorine and caustic. It relates, more specifically, to an electrolysis system including an improved diaphargm-type electrolytic diaphragm-type and apparatus containing multiple such diaphragm-type unit cells and to a method of operating such system. The present invention also relates to an improved such diaphragm-type electrolysis apparatus and improved electrolysis process using such improved diaphragm-type cells.
II. Description of the Prior Art
The benefits of the use of metal electrodes in the manufacture of chlorine-alkali, chlorate, perchlorates, etc. have been indicated in many publications: Canadian Pat. No. 771,140 issued Nov. 7, 1967 to S. I. Burghardt relates to the advantages of metal electrodes; Canadian Pat. No. 631,022 issued Nov. 14, 1961 to R. G. Cottam and M. G. Derlez relates to improvements in anodes of that type.
Diaphragm-type electrolytic cells have also advanced in performance with the availability of dimensionally stable anodes, e.g., metal anodes. In the chlor-alkali industry these anodes were proven successful commercially after 1966. However, electrolytic cell design has not changed too significantly even while imploying the new anodes.
It has recently been suggested that perfluorinated ion exchange membranes, especially that known by the Trade Mark of Nafion (Du Pont) be used as the diaphragm for chlorine and caustic production using such diaphragm-type electrolytic cells. It was suggested that if such diaphragm were successful in performance, the electrolytic cell employing this type of membrane would substantially eliminate several of the disadvantages of diaphragm cells, e.g., health hazard to personnel from ythe asbestos fibres heretofore used in the diaphragm. This would also obviate the requirement of salt crystallization and separation of catholyte which is not a necessity for the catholyte from the membrane cell. The membrane cell, however, offers challenges in design for efficient utilization of the properties inherent with membranes and the utilization of modules for ease of assembly and maintenance, as well as for optimum conditions.
For example, in chlorine/caustic production, the following are the reactions:
I. Anode reaction:
2C1.sup.- → Cl.sub.2 + 2e.sup.-
Brine is fed into the anode compartment of the cell and the spent brine plus chlorine is released from the compartment and cell.
ii. Cathode reaction:
2H.sub.2 O + 2e.sup.- → 2OH.sup.- + H.sub.2
water is fed into the cathode compartment of the cell and caustic plus hydrogen is released from the compartment and cell.
iii. Membrane:
The membrane provides an ionically conductive impermeable barrier substantially completely to prevent mixing of the gaseous products and electrolytes respectively. The membrane allows sodium ions to pass into the cathode compartment, but largely excludes both chloride and hydroxyl ions (caustic). The caustic thus formed in the cathode compartment is essentially salt free.
The diaphragm-type cells heretofore provided were of the single cell system-type which involves many concentrations and units for commerical production. This type is likely to be high in capital cost, difficult to control, high in maintenance cost and subject to production interruptions. If larger units are used, the amperage load would tend to be high, which increases power equipment cost and generally makes it difficult to design such cells for efficient and safe operations.
It has previously been found that the dimensions of the membrane, i.e., the width and length respectively, linearly expand up to 20% in the cell. This generally results in blockage of product flow and often results in cracking of the membrane. To minimize dimensional increase and also to strengthen the membrane, such membranes are generally available with a polytetrafluoroethylene fabric, e.g. that known by the Trade Mark of Teflon, on one side. The linear increase is less in this case, but still is significant (approximately 3%). The cell voltage tends to increase and in some cases the fabric results in a sealing problem.
It is known that the membrane must effectively divide the anode and cathode compartments without hydraulic leaks of electrolyte from one compartment to the compartment on the opposite side. Even a pinhole leak would, in most cases, be sufficient drastically to reduce the efficiency and would tend to jeopardize successful operation. Thus, a liquid-tight seal is of utmost importance.
It is also known that the membrane will fail with time as will other parts of the electrolyte system. The electrolytic system should, therefore, be of the type that may be easily disassembled and the parts thereof readily replaced.
The electrolyte flow rate should preferably be many times higher than material balance requirement in order to achieve highest efficiency. Minimum flow control is also desirable.
It is also desirable that the electrodes be spaced as closely as possible in order to minimize cell voltage, but they should not be spaced so closely that they block the flow of electrolyte and gaseous products.
It is also known that the current efficiency is drastically reduced at higher strength catholyte because of back migration of hydroxyl into the anode compartment.
SUMMARY OF THE INVENTION
i. Aims of the Invention
It is therefore an object of this invention to provide an electrolytic system, including modules, to yield satisfactory results and be an advancement in technology of electrolytic system employing membrane members ro separate anode and cathode products respectively. It is another object of this invention to provide high electrolyte flow rate by means of cascade flow and/or recirculation by hydraulic or gas lift and also by means of an hydraulic brine system, thereby not only tending to eliminate the need for flow control, but also allowing for use for temperature control if desirable.
It is yet another object of this invention to provide optimum electrode spacing by means of a module design.
It is a further object of this invention to provide proper balance in product strength and current efficiency by means of cascade modules within an electrolytic system in order that the end product be relatively high in strength while sacrificing only a minimum of current efficiency.
ii. Statement of the Invention
This invention provides, broadly, an anode unit for a diaphragm cell, the unit comprising a generally rectangular parallelepiped framework including a pair of spaced-apart, grid-like, structurally rigid, peripheral outer side walls; an ionically conductive gas impermeable membrane secured against the inner face of each outer peripheral walls; an anode sealingly disposed between the membrane to provide a pair of liquid-tight anode compartments; means for feeding anolyte to the anode compartments; and means for withdrawing spent anolyte and entrained and/or occluded gaseous products of electrolysis therein from the anode compartments.
This invention also provides an electrolyzer cell box comprising: (A) a plurality of rows of banks of interleaved anode units and cathode, with each bank comprising alternating anode units and cathodes, each anode unit/cathode comprising a generally rectangular parallelepiped framework including a pair of spaced-apart grid-like structurally rigid peripheral outer side walls; an ionically conductive gas impermeable membrane secured against the inner face of each such outer peripheral walls; an anode disposed between the membranes to provide a pair of anode compartments, the anode extending beyond the anode unit to provide a cathode, the cathode being provided with spacing electrically non-conductive buttons thereon; means for feeding anolyte to the anode compartments including a channel member along one edge thereof and a lower trough for feeding and distributing anolyte to the anode compartments; a header for receiving spent anolyte and entrained and/or occluded gaseous products of electrolysis and enabling the withdrawal thereof from the unit and for withdrawing spent anolyte and entrained and/or occluded gaseous products of electrolysis therein from the anode unit; and means associated with the inlet channel for separating and withdrawing entrained and/or occluded gaseous products of electrolysis from the anolyte before the anolyte is fed to the anode compartments; (B) an anode connecting means connected to the last anode of each row of anode units; (C) a cathode connecting means connected to the first cathode of each row of cathodes; (D) anolyte inlet means to the last anode unit of each row of anode units; (E) means for connecting the downstream anode unit to the immediately adjacent upstream anode unit in each row of anode units for cascading anolyte upstream and removing gaseous products of electrolysis; (F) spent anolyte outlet means from the first unit of each row of anode units; (G) catholyte inlet means to the cathode chambers; (H) spent catholyte outlet means; and (I) catholyte gas outlet means.
This invention, provides, still further, an electrolyzer cell box comprising a generally rectangular parallelepiped box containing: (A) a plurality of rows of banks of interleaved anode units and cathodes, with each bank comprising alternating anode units and cathodes, each such anode unit/cathode comprising a generally rectangular parallelepiped framework including a pair of spaced-apart grid-like structurally rigid peripheral outer side walls; an ionically conductive gas impermeable membrane secured against the inner face of each such outer peripheral walls; an anode disposed between the membranes to provide a pair of anode compartments, the anode extending beyond the anode unit to provide a cathode, the cathode being provided with spacing electriocally non-conductive buttons thereon; means for feeding anolyte to the anode compartments including a channel member along one edge thereof and a lower trough for feeding and distributing anolyte to the anode compartments; a header for receiving spent anolyte and entrained and/or occluded gaseous products of electrolysis and enabling the withdrawal thereof from the unit and for withdrawing spent anolyte and entrained and/or occluded gaseous products of electrolysis therein from the anode unit; and means associated with the inlet channel for separating and withdrawing entrained and/or occluded gaseous products of electrolysis from the anolyte before the anolyte is fed to the anode compartments; (B0) an anode connecting means connected to the last anode of each row of anode units; (C) a cathode connecting means connected to the first cathode of each row of cathodes; (D) anolyte inlet means to the last anode unit of each row of anode units; (E) means for connecting the downstream anode unit to the immediately adjacent upstream anode unit in each row of anode units for cascading anolyte upstream and removing gaseous products of electrolysis; (F) spent anolyte outlet means from the first unit of each row of anode units; (G) catholyte inlet means to the cathode chambers; (H) spent catholyte outlet means; (I) catholytic gas outlet means; (J) a downwardly sloping front wall; and (K) wedge means disposed between an adjacent anode unit of each bank and the front wall, thereby to hold the anode units in place.
This invention, also provides an electrolyzer cell box comprising a generally rectangular parallelepiped box containing: (A) a plurality of rows of banks of interleaved anode units and cathodes, with each bank comprising alternating anode units and cathodes, each such anode unit/cathode comprising a generally rectangular parallelepiped framework including a pair of spaced-apart grid-like structurally rigid peripheral outer side walls; an ionically conductive gas impermeable membrane secured against the inner face of each such outer peripheral walls; an anode disposed between the membranes to provide a pair of anode compartments, the anode extending beyond the anode unit to provide a cathode, the cathode being provided with spacing electrically non-conductive buttons thereon; means for feeding anolyte to the anode compartments including a channel member along one edge thereof and a lower trough for feeding and distributing anolyte to the anode compartments; a header for receiving spent anolyte and entrained and/or occluded gaseous products of electrolysis and enabling the withdrawal thereof from the unit and for withdrawing spent anolyte and entrained and/or occluded gaseous products of electrolysis therein from the anode unit; and means associated with the inlet channel for separating and withdrawing entrained and/or occluded gaseous products of electrolysis from the anolyte before the anolyte is fed to the anode compartments; (B) an anode connecting means connected to the last anode of each row of anode units; (C) a cathode connecting means connected to the first cathode of each row of cathodes; (d) anolyte inlet means to the last anode unit of each row of anode units; (E) means for connecting the downstream anode unit to the immediately adjacent upstream anode unit in each row of anode units for cascading anolyte upstream and removing gaseous products of electrolysis; (F) spent anolyte outlet means from the first unit of each row of anode units; (G) catholyte inlet means to the cathode chambers; (H) spent catholyte outlet means; (I) catholyte gas outlet means; (J) a downwardly sloping front wall; (K) wedge means disposed between an adjacent anode unit of each bank and the front wall, thereby to hold the anode units in place; (L) the anolyte inlet means being disposed near the top of the cell box; (M) a plurality of riser pipes extending upwardly from each anode unit, the riser pipes in each bank leading to a common connecting header, each common connecting header leading to an associated common outlet riser which in turn leads to a main anolyte gas outlet header pipe; (N) catholyte inlet means to the top of the seled cover; (O) spent catholyte outlet overflow weir means from the sealed cover disposed an optimum distance from the catholyte inlet means to provide controlled catholyte level and catholyte gas space; and (F) circulation means provided by internal pumping action due to the construction and arrangement of the cathodes and anode units and the rising gaseous products of the electrolysis of the catholyte, with the outlet means from the electrolyzer providing at least a partial separation of entrained gaseous products of electrolysis of the catholyte from the spent catholyte.
iii. Other Features of the Invention
By one variant of this invention, the unit includes a channel member along one edge thereof and a lower trough for feeding and distributing anolyte to the anode compartments, especially where the lower trough comprises a lower conduit provided with a plurality of upper spaced-apart apertures for feeding anolyte to the anode compartments.
By another variant, the unit includes an upper header for receiving spent anolyte and entrained and/or occluded gaseous products of electrolysis and enabling the withdrawal thereof from the unit, especially where the upper header comprises an upper conduit provided with a plurality of lower spaced-apart apertures for withdrawing anolyte and entrained and/or occluded products of electrolysis from the anode compartments.
By still another variant, the unit includes means associated with the inlet channel for separating and withdrawing entrained and/or occluded gaseous products of electrolysis from the anolyte before the anolyte is fed to the anode compartments, especially where the inlet channel comprises a conduit provided with an upper "I" member, disposed on its side, the horizontal portion providing a liquor/gas inlet, the lower vertical portion providing a liquor inflow conduit, the upper vertical portion providing a gas outflow conduit.
By yet another variant, the unit includes means for recirculating anolyte within the anode compartments of the anode unit.
By a variation thereof, such means comprises a vertical channel member provided with vertical flanges for holding the anode, the flanges being provided with upper and lower recirculation perforations, especially where sealing gaskets are provided between the vertical flanges and the anode.
By another variant, the anode extends beyond the anode unit to provide a cathode.
By a variation of such variant, the cathode is provided with spacing electrically non-conductive buttons thereon.
By still another variant, the anode unit is provided as a plurality of components bolted together by peripherally disposed bolts, especially where the bolts pass through mating apertures in opposed peripheral portions of the framework, the apertures being provided with sealing sleeves or gaskets.
By yet another variant, the anode is titanium, or titanium having a coating thereon of ruthenium oxide, platinum or platinum/iridium thereon.
By a further variant, the cathode is titanium, low carbon mild steel, or nickel alloys.
By a still further variant, the membrane is a thin unsupported film of plastic material, e.g. a polytetrafluoroethylene fabric reinforced thin plastic material, or a perfluorinated ion exchange membrane.
By yet another variant, the grid-like outer walls comprise a structurally rigid membrane supporting sheet provided with openings or perforations.
By a variation of such variant, the framework is provided with three inwardly facing channels, within which the plurality of components are disposed, the anode being disposed in the mid-channel, with sealing members disposed between the structurally rigid membrane, supporting sheet and outer flanges defining a limit of the outer channels.
By a still further variant, the grid-like outer walls comprise expanded metal, e.g. titanium, sheeting.
By still another variant, the grid-like outer walls comprise porous sintered powder sheeting, e.g. are formed of titanium or plastic; the sheet to have at least 45% open area.
By yet another variant, the grid-like outer walls and membranes are in the form of a single unit comprising porous sintered powdered titanium sheeting of 70% or more porosity within whose pores are disposed powdered perfluorinated ion exchange material.
By yet another variant, there is a sealing gasket provided between the membrane and spacing members disposed adjacent the anode.
By yet another variant of this invention, the cover slopes upwardly from the catholyte inlet to the catholyte gas outlet, especially wherein the catholyte gas outlet leads directly from the cover, from a point adjacent the greater cross-sectional area end thereof.
By a second variant of this invention, the cover includes a tray comprising an external extension of the cover, through which the common outlet risers extend.
By yet another variant, the wedge extends for substantially the entire height of the cell box.
By still another variant, the wedge cooperates only with the top portion of the cell box.
By a still further variant, the liquor outflow means from each anode unit includes a degasifier zone and an outflow riser pipe leading from the degasifier zone to the connecting header.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings,
FIG. 1 is a side elevational view of an anode/membrane/cathode unit of one aspect of this invention;
FIG. 2 is a section along the line II--II of FIG. 1;
FIG. 3 is a side elevational view of the module frame used in a variant of this invention;
FIG. 4 is a section along the line IV--IV of FIG. 3;
FIG. 5 is a sectional view, similar to FIG. 3, showing another variant of this invention;
FIG. 6 is a side elevational view, partly shown in phantom, of an electrolysis system of another aspect of this invention provided with the anode/membrane/cathode unit of an aspect of this invention;
FIG. 7 is an end elevational view of the electrolysis system of FIG. 6, shown partly in phantom;
FIG. 8 is a section along the line VIII--VIII of FIG. 6;
FIGS. 9A and 9B are cross-sectional views, partially in broken lines, of the assembled units of one aspect of this invention, in an electrolysis system of another aspect of this invention; and
FIG. 10 is a section similar to that of FIG. 8, but of a different embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
i. Description of FIGS. 1 and 2
As seen in FIGS. 1 and 2, the anode/membrane/cathode unit 10 of one aspect of this invention is a hollow rectangular parallelepiped including two outer side walls comprising generally rectangular structural supports 11 which are generally of the same rectangular shape as the unit 10. It is essential that the structural supports 11 be porous. The structural sheeting 11 employed herein according to variants of the invention has openings, or perforations, 12 or is provided as expanded sheeting or porous fused powder sheeting. Plastic sheeting is possible, but titanium is preferred because of its structural advantages and best performance. By this invention, it is possible to take advantage of the structural strength and support characteristics and perforations. Structurally, the sheet substantially prevents the membrane from "flexing" against the cathode.
Disposed against each of the inside faces of each of the structural sheetings 11 is an internal membrane 13. The membrane provides an ionically conductive impermeable barrier, as described hereinabove. One particularly effective material for the membrane 13 is Nafion film, 1 to 20 mils thick, available from Du Pont.
Sealingly held centrally within the hollow rectangular parallelepiped is an anode 14 providing a pair of anode compartments 15. One end of the anode 14 is set within the spaced-apart flanges 16 of a vertically positioned anolyte recirculation channel member 17. While not shown, the flanges 16 at the top and bottom of the channel member 17 are each provided with perforations to enable anolyte flow. The channel member 17 is held against, but maintained in liquid-tight relationship to, membrane 13, by means of gasket 18.
The other end of the anode 14 projects beyond the anolyte chambers 15 and is held in liquid-tight contact by means of gaskets 19 in contact with the anode 14, and 20 in contact with the membrane 13, as well as suitable spacers 21. The anode module section is held together by a plurality of peripherally spaced bolt 22 and nut 23 units.
The portion of the anode 14 which protrudes from the anode compartments 15 of the module 10 is the cathode 25. The cathode 25 preferably is titanium but may also be other cathodic material, e.g. steel; in such case, there should be an overlap at the bolt joint. The cathodes 25 are equipped with plastic buttons or rivets 26. Suitable materials include Teflon, polyvinyl chloride (PVC), etc. The purpose of these buttons is by means of the electrically resistant buttons to space the cathode sheet from an adjacent module to ensure that they do no short circuit. Furthermore, without adjustment and alignment by loosely fitting against each other, proper and desirable spacing for the catholyte is established by these means.
The length of the cathode 25 is shorter than the length of the anode module section. This provides a channel 91 (see FIGS. 6A and 6B) for recirculation of catholyte, if desired, by hydrogen gas lift driving force.
Provided on the upstream side of the anode unit 10 is a downcomer channel support anolyte inlet 27. Anolyte inlet 27 has a height greater than the height of the anode unit 10, and so provides a space 28 for gas/liquid separation. The gas is drawn off via anolyte gas outlet 28a, while the liquor is led to a horizontal distributor base trough 29 leading freely to the anode compartments 15. The anolyte rises by gas lift to an upper header 30 which is provided with a common liquor and gas outlet pipe 31. This may be connected to an elbow 32 to an inlet 33 to anolyte inlet 27.
In one embodiment of the invention, the porous structural support was a perforated 0.3 mm thick titanium sheet, 2 mm holes about 45% open area. This gave a differential voltage increase of 0.1 volt at 1500 amps per square meter. A plastic sheet would have to be thicker (up to 1 mm) and voltage increase becomes significant (0.5 and higher).
In a further embodiment of this invention in producing the membrane, Nafion powder, 0.2 to 0.5 mm in size was ground under liquid nitrogen freezing conditions. Porous powder titanium sheeting (70% porosity, 10-30 micron pore size) was plugged with this powder and successfully operated as a dimensionally stable membrane, i.e., in this case the module would not require any structural member.
2 mm thick sheeting is about the maximum to achieve reasonable voltage readings; 1 mm is preferred and 0.2 mm would be the extreme minimum due to the low mechanical strength. For thicker sheets it is important electrically to short circuit this membrane with the cathode/anode, otherwise the cell voltage could significantly increase (probably gas build-up inside the plate if partially working as a cathode).
The membrane may be of different types:
a. a film about 0.03 to 0.3 mm thick; this film is the "membrane" without additives. This film is lower in voltage but has less mechanical strength and readily swells with very large width and length linear dimensional increase at the normal cell conditions up to 20%. Thus, when used in a dimensional stable frame the film, after a few days, appears as a corrugated mesh (i.e., expansion occurs in both directions) which could seriously upset good flow conditions as well as seal itself against the electrodes in some areas which also contributes to increased voltage. This uncontrolled dimensional swelling also lowers the life cycle of the film.
b. a film as above but reinforced with Teflon fabric. This does mechanically improve the film as well as lower its linear dimensional increase to less than 5%; however, even this is large. Furthermore, the cell voltage is significantly increased by the resistance of Telfon fabric (up to 1 volt at 1600 amps per square meter).
By another embodiment of this invention, the above-noted membranes may be used, i.e. by the use of a structural member, in association with the membrane. In all cases, some member (frame or flange) is required to cause an effective seal of the membrane against the gasket.
With a pressure higher inside the module than outside, the linear expansion is directed into the perforated holes. Thus, voltage actually is reduced by the enlarged surface area. The sheeting will have the appearance of multi-indentations from the anode side after being used in the cell. The thin structural member extends the life of the membrane by the multi-unit swellings which is "gentle" on the film. The perforated member is, by the small thickness, able to flex just sufficiently not unduly to wear the membrane. Using a powder, either porous or perforated, the sheet gives a slight improvement at about double the sheet thickness compared to the solid perforated sheet, but the cost is significantly higher and this sheet has a tendency of cracking and breaking up. A thicker sheet which structurally is satisfactory shows poorer voltage performance (up to 0.5 volt differential voltage). A 2 mm thick, 70% porosity, 10 micron pore size, machined to make 4 mm diameter indentations to about 1.8 mm deep (i.e., not perforated) did not improve on the result of the thin perforated solid sheet.
An inherent property of titanium is that is oxidizes as the anode and the sheet for practical purposes becomes inactive under normal cell conditions. Already after 20 minutes operating current flow to and from the structural member is less than 0.6% and after 24 hours it is less than 0.2%.
The anode module section comprises structural members having a dual purpose, namely: (i) to channel the anolyte, and (ii) to support and frame the membrane. The active anolyte flows between the anode and the membrane which is spaced on each side of the anode. The spacing is controlled by gaskets of suitable material, e.g. silastic rubber and spacers of titanium, hard rubber, Teflon or other chemically resistant material. The spacing for the anolyte flow is not more than 15 mm (voltage increase with spacing); on the other hand, not less than 1 mm since restriction of flow also causes high voltage. The channels have a dual purpose, namely: (i) to provide firm flanges for sealing the anode compartment which is essential in order to achieve acceptable products and current efficiency; and (ii) anolyte is recirculated within the module compartment, if desirable, by employing a channel to allow anolyte to flow back from the top to the bottom by means of up-lift of gas produced onto the anode. This is important only if anolyte velocity would be low (below 15 meter per hour). The flanges must be perforated for the top and the bottom flanges in order to allow the anolyte to enter the compartment and leave, respectively, into the top channel to discharge through the outlet nozzle and for recirculation via the channel if desirable.
The channel member 17 may be titanium (which structurally is more stable) or a plastic extrusion, e.g. polyvinyl dichloride (PVDC) or polypropylene. It should be noted that although the rectangular profile is the most compact module design, a circular tube may also be used. In case titanium is used, care must be taken electrically not to short circuit the cells. This is avoided by allowing the gasket 18 to extend and fold over the bolt head 33 and nut 23 respectively. The bolts preferably are of plastic material, e.g. polypropylene, which will minimize buttons on the cathodes. However, titanium machine bolts and countersunk screws, respectively, may be used without problems.
ii. Description of FIGS. 3 and 4
As seen in FIGS. 3 and 4, the module frame 120 includes a pair of spaced-apart peripheral bars 118, 119 extending completely around to provide the main framework. A plurality of equally spaced-apart apertures 121 are provided for the bolts 122 which hold the components together. Along the upstream vertical side 123 is an inlet conduit 127, which in this variant, is a tubular conduit. Tubular conduit 127 leads directly to a bottom feeder 129, which, in this variant, is a tubular conduit. Tubular conduit 129 is provided with a plurality of spaced-apart apertures 128 for the feeding of anolyte liquor to the anolyte chambers 115. A header 130 is provided at the top, the header 130 being fed by a plurality of spaced-apart apertures 131 for the outflow of anolyte and cell gas from the anolyte chambers 115. The downstream vertical side of the frame is provided with a transverse spacer bar 132.
As seen in FIG. 3, the apertures 121 are each provided with gaskets 133 to prevent liquor leakage. The gaskets are preferably formed of silastic. By these means, leakage through the bolt holes is greatly minimized.
iii. Description of FIG. 5
As seen in FIG. 5, the peripheral framework is provided by flanged members 220 provided with central U-channel 221 defined by flanges 222, 223, and external channels 224, 225, defined by flanges 226 and 222, and by flanges 223 and 227, respectively. Each of flanges 222, 223, 226 and 227 extends completely around the internal periphery of the frame members 220. The downcomer channel support anolyte inlet 327 is disposed on the outside of channel framework 220. The membrane supports 211 are disposed in channels 224 and 225 and are sealed against the inside faces of flanges 226 and 227 by O-ring seals 228, 229 formed, e.g. of "Vitron" rubber or "Teflon". The usual gaskets 218 are provided in channels 224, 225 between the membranes 213 and the flanges 222, 223. The membranes 213 are sealed against the flanges, or against the gaskets if the surface of the flanges is not sufficiently flat, by compression of O-rings. The O-rings are squeezed into position and are held by the upper flanges. This provides a substantially leak-free construction.
Thus, as described above, special care must be taken to provide a seal, e.g. of silastic rubber, between the bolts and the holes, to minimize and even substantially to avoid leakage of anolyte. Bolting can be eliminated by using the design of another embodiment of this invention by pressing the membrane against a flange using a wedge or an O-ring seal.
iv. Description of FIGS. 6 and 7
Turning now to FIGS. 6 and 7, the container 50 for the electrolysis system is a generally rectangular tank 51 including a back wall 52, a downwardly inwardly sloping front wall 53, a bottom 54, a pair of end closures 55 and a top cover 56. The top cover slopes upwardly 57 toward the anolyte inlet end where anolyte is fed to the electrolysis unit via anolyte inlet 58. A tray extension 59 surrounding the cover 56 is provided associated with the cover 56, for a purpose to be explained hereinafter. The catholyte is fed in through an upper catholyte inlet tube 60 and spent catholyte is withdrawn via weir overflow 67. The catholyte gases accumulate in the upper region 56a of the cell below the cover 56 and are led out via catholyte gas outlet 61. The anolyte enters through anolyte inlet tube 58 and is withdrawn via spent anolyte tube 62. The anolyte gases are accumulated in outlet lines 63 and are fed to gas header 64 from whence they are drawn off through outflow pipes 65 to header pipe 66.
The tray 59 allows anolyte gas outlet pipes 65 to outlet on the outside of the cover 56 (which is sealed) and through tray 59, thereby maintaining catholyte liquor level below the cover 56, and a gas pressure less than the available liquor seal head which is established by outlet (catholyte finished product) weir pipe 67. All anolyte gas pipes 65 are discharged into the header pipe 66. The cover 56 is preferably sloped at 57 to lead catholyte gases to the outlet mozzle 61, thus minimizing gas volume at the top 56a of the electrolyzer 50. The liquor level should not reach the cover 56; an actual gas zone 56a is required in order not to pump liquor by gas lift to the adjacent cell which would cause internal curculation and mixing, which is not desired for maximum efficiency result. The gas zone requirement is least at the first cell; the last cells have the accumulated gases from all cells (catholyte gases). The gas outlet may be at the centre of the length sloping both sides which would require less gas zone, but it is generally more convenient to have the outlet at one end.
The liquor feed inlet 60 for the catholyte is located at the opposite end of the weir pipe outlet 67 in order gradually to increase the strength of the catholyte product. The strength increases linearly when plotted against the cell member. The differential increase in concentration depends upon current load and flow rate.
v. Description of FIGS. 9A and 9B
The container is required to be electrically resistant to establish multi-cell assembly; for chlor/alkali system, a polyester resin tank, glass fibre reinforced, is satisfactory. Since the catholyte only is in contact with the container, the corrosion attack is not severe. This design is preferred also since it minimizes health risks by gas leaks should the cover lift or the seal fail. Actually it would not be practical to employ the liquor seal by electrolyte if it was anolyte from a chlorine cell since some chlorine would be vaporizing from seal liquor. It is, however, possible to reverse conditions using catholyte inside the module member. However, it is advantageous to have catholyte in the main container.
Disposed within the cell container 50 are a plurality of rows n, n + 1, n + 2, etc. and columns N, N + 1, N + 2, etc. of interleaved anode units 10 and cathodes 25. Thus, there are a number of rows, n, n + 1, n + 2, n + 3, n + 4, etc., and in each row there are a plurality of interleaved anode units 10 and cathodes 25, i.e. N, N + 1, N + 2, etc. As seen in FIGS. 9A and 9B, the cathode 25 from unit 2n is disposed between anode units n + 1 and 2(n + 2). The cathodes 25 in the first row n are each connected to a cathode connector 75 by means of entry into a slot 76 and being held in place by bolt 77 and nut 78 unit passing through registering appertures 79. Similarly, each anode unit 10 at the end is provided with an anode extension 80 disposed in a slot 81 in an anode connector 82 and is held therein with bolt 83 and nut 84 unit passing through registering apertures 85.
The plastic buttons 26 on cathodes 25 provide a means of spacing the cathodes from the anode units 10, thereby providing cathode chambers 90 between anode unit 10/cathode 25 couples in the same column, and catholyte channel 91 between cathode 25/anode unit 10 of adjacent columns.
vi. Description of FIG. 8
The anolyte interconnections are as shown in FIG. 8 by means of anolyte gas and liquor outlet 31 of an anode unit 10 of one column, i.e. 2(2 + 4) to the inlet downcomer channel 27 of an anode unit 10 of an adjacent, upstream column, i.e., n + 3, and the outlet pipe 31 of that anode unit 10, i.e. n + 3, feeds the inlet downcomer channel 27 of an adjacent, upstream column, i.e. 2(n + 2).
The forward anode unit 10 of each column is held in place within the cell container 50 by means of cooperation between its peripheral framework and a wedge 86 contacting the sloping front wall 53. This takes up any variations in width of the anode unit 10 without making the cell tank 50 of different width for each column of anode unit 10/cathode 25 couple.
vii. Operation of Preferred Embodiments
The number of cells depends on the supply voltage. The module member is set upright onto the bottom of the unit container. A second module is connected longitudinally via a connector. The third module is connected via a connector to the second, etc., until all the cells are assembled and the last module member connected to the outlet connector.
For an amperage load of about 20,000 amps approximately 50 modules would be employed in each cell. To make installation easy and to secure spacing between modules, a wedge member, e.g., polycarbonate member, is found to be very desirable.
Current connectors are at each end of the container. Current flow through the unit is shown as in the prior art. Current leakage between cells is defined by ohms (low) with voltage potential equal to the average cell voltage and cross-sectional area of the electrolyte communicating/channelling between cells. This channelling is clearly defined for anolyte by the module connectors and the channels, and since the current path would normally be long, the current leakage is insignificant. To minimize the current leakage for catholyte (mainly in the channel above the module members), cell divider sheets may be employed at the top (not shown: vertical sheets along the imaginary line between the anode and the cathode). For most units the current leakage would be less than 1% without employing divider sheets (depending upon current load; higher load gives less current leakage percentagewise).
With anolyte, the gas produce on the anode (i.e. chlorine) will be discharged as well as dispersed via a connector to an inlet. Gas leaving through the discharge with the anolyte flows downwardly by hydraulic effect (brine feed head and static head in the pipe risers) through a channel through bottom opening into another channel and further into the anode compartment for a new cycle to the next module.
The anolyte flow may be described as follows: The fresh brine enters via inlet pipe 58 to the downcomer channel 27. It then flows downwardly to the horizontal distributor trough 29 where it leads by unencumbered slots directly to the anode chambers 15 within the anode unit. The brine flows upwardly in the anode chambers and is subjected to electrolysis to provide brine plus entrained and/or occluded chlorine gas, and this mixture is accumulated in the anode unit header 30. The liquor/gas mixture flows to the adjacent anode unit, i.e. via outlets 31, 32, 33 to the downcomer channel 27. Since the downcomer channel 27 includes a portion 28 at a higher level, a gas/liquid interface is formed. The anolyte may also be recirculated through perforations in the flanges 16 of the channel 18. The chlorine is drawn off via line 28a, while the brine is fed downwardly to be further electrolyzed in the next upstream anode unit 10.
The catholyte flow may be described as follows. It enters through the upper catholyte inlet pipe 60 and passes downwardly through the cathode chambers 90 and channels where it is electrolyzed. The catholyte then rises by gas lift, and is withdrawn as caustic via weir overflow 67. The catholyte gas, i.e. hydrogen, passes through the cover header 56a and is withdrawn via outlet pipe 61.
The current flow may be described as follows. Current in the anode 14 flows longitudinally along the anode 14 and transversely across the anolyte in chamber 15, through the membrane 13, across the catholyte in chamber 90 and then longitudinally along the cathode 25 until it once again becomes a flow along the length of the anode 14. The cathode connectors 75 draw off this anode flow.
The system of an aspect of this invention provides the means which could achieve high efficiency and favourable manufacturing factors. It also offers the option of a choice of conditions and material selections. These options likely affect result, but the flexibility is desirable to make maximum use of the know-how and availability of material. In the case of a chlorine/alkali cell, e.g.:
i. The anode may be titanium, surface coated with ruthenium oxide, platinum, or platinum/iridium, respectively, and the voltage performance would normally be slightly different, but depending on application of coating, could differ in result as much as 20%.
ii. the cathode may be low carbon mild steel, surface treated titanium, nickel, or alloys. The choice of cathode could affect result drastically (up to 20% on voltage). Titanium is preferred, which has been surface treated to give an overvoltage potential equal or better than mild steel.
iii. The membrane thickness and polymer equivlent weight are factors on cell voltage; less thickness and equivalent weight polymer result in lower cell voltage, but also lower current efficiency and product purity.
iv. Flow rate of liquor through the system, current density, operating temperature, are other factors affecting result, i.e., efficiency of power consumption per unit production and product purity.
viii. Description of FIG. 10
The embodiment of FIG. 10 is similar to that of FIG. 8 except that the cathode 25 is provided with an elbow portion 725. In this way, the connecting tubes 32 need not be laterally offset to connect anode units in different rows as well as differnet colums. It is then possible to provide interleaved, but not offset, anode/cathode assemblies.
SUMMARY
In conclusion, the improvment provided herein provides for flexibility and high efficiency under set conditions.
From the foregoing description, one skilled in the are can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and mofifications of the invention to adapt it to various usages and conditions. Consequently, such changes and modifications are properly, equitably, and "intended" to be, within the full range of equivalence of the following claims.
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A novel anode unit is provided for a diaphragm cell. The anode unit comprises a generally rectangular parallelepiped framework including a pair of spaced-apart grid-like structurally rigid peripheral outer side walls; an ionically conductive gas impermeable membrane secured against the inner face of each such outer peripheral walls; an anode sealingly disposed between the membranes to provide a pair of fluid-tight anode compartments; means for feeding anolyte to the anode compartments; and means for withdrawing spent anolyte and entrained and/or occluded gaseous products of electrolysis therein from the anode unit. Novel diaphragm electrolytic cells including such anode units are also provided.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/405,021 filed on Apr. 14, 2006, which claims the benefit of U.S. Provisional Application No. 60/674,781 filed on Apr. 26, 2005. The disclosures of the above applications are incorporated herein by reference.
FIELD
[0002] The present teachings relate to compressors, and more particularly, to a compressor information network.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] Compressors are used in a variety of industrial and residential applications to circulate refrigerant within a refrigeration, heat pump, HVAC, or chiller system (generically “refrigeration systems”) to provide a desired heating or cooling effect. In each application, it is desirable for the compressor to provide consistent and efficient operation to ensure that the refrigeration system functions properly. To this end, a compressor may be operated with an associated protection and control system.
[0005] The protection and control system may monitor operating signals generated by compressor or refrigeration system sensors and determine compressor or refrigeration system operating data. For example, the protection and control system may determine whether compressor or refrigeration system faults have occurred. Such data, however, may be lost when the protection and control system is turned off and/or when the protection and control system is no longer associated with the compressor.
[0006] A particular protection and control system may be compatible with a number of different compressor models and types of varying capacities. Traditionally, during installation it is necessary to load compressor specific data including, for example, numerical constants corresponding to the compressor model, type, and capacity into the protection and control system. Such compressor data is generally published by the compressor manufacturer, and used during refrigeration system design. The compressor data may be used during operation of the compressor by the protection and control system to control, protect, and/or diagnose the compressor and/or refrigeration system.
[0007] Loading the compressor data into the protection and control system is an additional step performed by the installer in the field. An error by the installer in the field while loading the compressor data may not be immediately apparent and may cause future compressor or refrigeration system operational problems. Further, if either the protection and control system, or the compressor, are replaced, the compressor data must be reloaded. In the field, such compressor data may be lost when the protection and control system and the compressor are no longer associated.
SUMMARY
[0008] A system is provided including a compressor having a first non-volatile memory connected to a module. The module has a processor and a second non-volatile memory. The first non-volatile memory is associated with the compressor. The module is selectively attached to the compressor and the processor is configured to access the first and second non-volatile memories.
[0009] In other features, the first non-volatile memory is embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0010] In other features, the system further includes a connector block attached to the compressor to allow an electrical connection between an interior and an exterior of the compressor and the first non-volatile memory is embedded within the connector block.
[0011] In other features, the system further includes an RFID device that includes the first non-volatile memory.
[0012] In other features, the first non-volatile memory stores compressor specific data including at least one of: compressor model type data; compressor serial number data; compressor capacity data; compressor operating coefficient data comprising numerical constants associated with said compressor and used to calculate compressor operating data.
[0013] In other features, the first non-volatile memory stores compressor specific data including at least one of: compressor bill of materials data; compressor build sheet data; compressor build date data; compressor build plant data; compressor build shift data; compressor build assembly line data; compressor inspector data.
[0014] In other features, the first non-volatile memory stores compressor specific data including at least one of: compressor energy efficiency ratio data; compressor low voltage start data; compressor wattage data; maximum compressor electrical current data; compressor refrigerant flow data.
[0015] In other features, the first non-volatile memory stores compressor specific data including at least one of: compressor installation location data; compressor installation date data; compressor installer data; compressor purchase location data.
[0016] In other features, the first non-volatile memory stores compressor specific data including at least one of: compressor repair date data; compressor repair type data; compressor repaired parts data; compressor service technician data.
[0017] In other features, the first non-volatile memory stores compressor specific data including at least one of: suction pressure data; discharge pressure data; suction temperature data; discharge temperature data; electrical current data; electrical voltage data; ambient temperature data; compressor motor temperature data; compression element temperature data; compressor bearing temperature data; oil temperature data; compressor control data.
[0018] In other features, the first non-volatile memory stores refrigeration system data including at least one of: condenser temperature data; evaporator temperature data.
[0019] In other features, the first non-volatile memory stores compressor fault history data.
[0020] In other features, the system includes a communication device connected to the module to perform writing data to the first non-volatile memory and/or reading data from said first non-volatile memory.
[0021] Additionally, a compressor is provided having a non-volatile memory that stores manufacturing data related to the compressor.
[0022] In other features, the non-volatile memory is embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0023] In other features, the compressor has a connector block attached to the compressor to allow an electrical connection between an interior and an exterior of the compressor, the non-volatile memory embedded within the connector block.
[0024] In other features, the compressor has an RFID device that includes the first non-volatile memory.
[0025] In other features, the manufacturing data includes at least one of: model type data of said compressor; serial number data of said compressor; capacity data of said compressor; operating coefficient data of said compressor comprising numerical constants associated with said compressor and used to calculate compressor operating data.
[0026] In other features, the manufacturing data includes at least one of: bill of materials data of said compressor; build sheet data of said compressor; build date data of said compressor; build plant data of said compressor; build shift data of said compressor; build assembly line data of said compressor; inspector data of said compressor.
[0027] In other features, the manufacturing data includes at least one of: energy efficiency ratio data of said compressor; low voltage start data of said compressor; wattage data of said compressor; maximum electrical current data of said compressor; refrigerant flow data of said compressor.
[0028] A method is provided for a compressor having a non-volatile memory. The method includes storing manufacturing data related to the compressor in the non-volatile memory.
[0029] In other features, the storing the manufacturing data related to the compressor in the non-volatile memory includes storing the manufacturing data in the non-volatile memory embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0030] In other features, the storing the manufacturing data related to the compressor in the non-volatile memory includes storing the manufacturing data in the non-volatile memory embedded in a connector block attached to the compressor, the connector block allowing an electrical connection between an interior and an exterior of the compressor.
[0031] In other features, the storing the manufacturing data related to the compressor in the non-volatile memory includes storing the manufacturing data in the non-volatile memory in an RFID device.
[0032] In other features, the storing the manufacturing data includes storing at least one of: model type data of the compressor; serial number data of the compressor; capacity data of the compressor; operating coefficient data of the compressor comprising numerical constants associated with the compressor and used to calculate compressor operating data.
[0033] In other features, the storing the manufacturing data includes storing at least one of: bill of materials data of the compressor; build sheet data of the compressor; build date data of the compressor; build plant data of the compressor; build shift data of the compressor; build assembly line data of the compressor; inspector data of the compressor.
[0034] In other features, the storing the manufacturing data includes storing at least one of: energy efficiency ratio data of the compressor; low voltage start data of the compressor; wattage data of the compressor; maximum electrical current data of the compressor; refrigerant flow data of the compressor.
[0035] Additionally, a method is provided including accessing a first non-volatile memory associated with a compressor using a processor associated with at least one of a second non-volatile memory and an operating memory. The method also includes storing compressor data from the second non-volatile memory or the operating memory in the first non-volatile memory, and accessing the compressor data in the first non-volatile memory to evaluate compressor performance.
[0036] In other features, the accessing the first non-volatile memory includes accessing the first non-volatile memory embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0037] In other features, method further includes electrically connecting an interior and an exterior of the compressor through a connector block wherein the accessing the first non-volatile memory includes accessing the first non-volatile memory embedded in the connector block.
[0038] In other features, the accessing the first non-volatile memory includes accessing the first non-volatile memory in an RFID device.
[0039] In other features, the storing the compressor data includes storing at least one of: compressor model type data; compressor serial number data; compressor capacity data; compressor operating coefficient data comprising numerical constants associated with said compressor and used to calculate compressor operating data.
[0040] In other features, the storing the compressor data includes storing compressor operating coefficient data comprising numerical constants associated with the compressor, the method further including calculating compressor operating data based on the compressor numerical constants.
[0041] In other features, the storing the compressor data includes storing at least one of: compressor bill of materials data; compressor build sheet data; compressor build date data; compressor build plant data; compressor build shift data; compressor build assembly line data; compressor inspector data.
[0042] In other features, the storing the compressor data includes storing at least one of: compressor energy efficiency ratio data; compressor low voltage start data; compressor wattage data; maximum compressor electrical current data; compressor refrigerant flow data.
[0043] In other features, the storing the compressor data includes storing at least one of: compressor installation location data; compressor installation date data; compressor installer data; compressor purchase location data.
[0044] In other features, the storing the compressor data includes storing at least one of: compressor repair date data; compressor repair type data; compressor repaired parts data; compressor service technician data.
[0045] In other features, the storing the compressor data includes storing at least one of: suction pressure data; discharge pressure data; suction temperature data; discharge temperature data; electrical current data; electrical voltage data; ambient temperature data; compressor motor temperature data; compression element temperature data; compressor bearing temperature data; oil temperature data; compressor control data.
[0046] In other features, the method further comprises storing refrigeration system data from the second non-volatile memory or the operating memory in the first non-volatile memory, wherein the storing refrigeration system data includes storing at least one of: condenser temperature data and evaporator temperature data.
[0047] In other features, the storing the compressor data includes storing compressor fault history data.
[0048] Additionally, a performance evaluation method for a compressor having a removable module including a processor and a first non-volatile memory is provided. The method includes accessing compressor data stored in a second non-volatile memory associated with the compressor and evaluating the compressor data to determine compressor performance.
[0049] In other features, the accessing the compressor data stored in the second non-volatile memory includes accessing the second non-volatile memory embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0050] In other features, the method further includes electrically connecting an interior and an exterior of the compressor through a connector block wherein the accessing the compressor data includes accessing the second non-volatile memory embedded in the connector block.
[0051] In other features, the accessing the compressor data includes accessing the second non-volatile memory in an RFID device.
[0052] In other features, the accessing the compressor data includes accessing at least one of: compressor model type data; compressor serial number data; compressor capacity data; and compressor operating coefficient data comprising numerical constants associated with said compressor and used to calculate compressor operating data.
[0053] In other features, the accessing the compressor data includes accessing at least one of: compressor bill of materials data; compressor build sheet data; compressor build date data; compressor build plant data; compressor build shift data; compressor build assembly line data; compressor inspector data.
[0054] In other features, the accessing the compressor data includes accessing at least one of: compressor energy efficiency ratio data; compressor low voltage start data; compressor wattage data; maximum compressor electrical current data; compressor refrigerant flow data.
[0055] In other features, the accessing the compressor data includes accessing at least one of: compressor installation location data; compressor installation date data; compressor installer data; compressor purchase location data.
[0056] In other features, the accessing the compressor data includes accessing at least one of: compressor repair date data; compressor repair type data; compressor repaired parts data; compressor service technician data.
[0057] In other features, the accessing the compressor data includes accessing at least one of: suction pressure data; discharge pressure data; suction temperature data; discharge temperature data; electrical current data; electrical voltage data; ambient temperature data; compressor motor temperature data; compression element temperature data; compressor bearing temperature data; oil temperature data; compressor control data.
[0058] In other features, method further includes accessing refrigeration system data from the second non-volatile memory associated with the compressor, including accessing at least one of: condenser temperature data; evaporator temperature data.
[0059] In other features, the accessing the compressor data includes accessing compressor fault history data.
[0060] Additionally, a system is provided that includes a remote module operable to communicate with a plurality of local modules. Each local module includes a processor and a first non-volatile memory associated with the processor. The processor communicates with the first non-volatile memory and a second non-volatile memory associated with a compressor. The remote module includes a database of information copied from the second non-volatile memory.
[0061] In other features, the second non-volatile memory is embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0062] In other features, the system further includes a connector block attached to the compressor to allow an electrical connection between an interior and an exterior of the compressor, wherein the second non-volatile memory is embedded within the connector block.
[0063] In other features, the system further includes an RFID device that includes the second non-volatile memory.
[0064] In other features, the local module is selectively attached to the compressor.
[0065] In other features, the local module is one of: a compressor protection and control system, a system controller, or a hand-held computing device.
[0066] In other features, the local module and the remote module are connected via a computer network.
[0067] In other features, the compressor has a connector block attached to the compressor to allow an electrical connection between an interior and an exterior of the compressor wherein the second non-volatile memory is embedded within the connector block.
[0068] In other features, the second non-volatile memory stores compressor specific data including at least one of: compressor model type data; compressor serial number data; compressor capacity data; compressor operating coefficient data comprising numerical constants associated with the compressor and used to calculate compressor operating data. The local module communicates the compressor specific data to the remote module for storage in the database.
[0069] In other features, the second non-volatile memory stores compressor specific data including at least one of: compressor bill of materials data; compressor build sheet data; compressor build date data; compressor build plant data; compressor build shift data; compressor build assembly line data; compressor inspector data. The local module communicates the compressor specific data to the remote module for storage in the database.
[0070] In other features, the second non-volatile memory stores compressor specific data including at least one of: compressor energy efficiency ratio data; compressor low voltage start data; compressor wattage data; maximum compressor electrical current data; and compressor refrigerant flow data. The local module communicates the compressor specific data to the remote module for storage in the database.
[0071] In other features, the second non-volatile memory stores compressor specific data including at least one of: compressor installation location data; compressor installation date data; compressor installer data; compressor purchase location data. The local module communicates the compressor specific data to the remote module for storage in the database.
[0072] In other features, the second non-volatile memory stores compressor specific data including at least one of: compressor repair date data; compressor repair type data; compressor repaired parts data; compressor service technician data. The local module communicates the compressor specific data to the remote module for storage in the database.
[0073] In other features, the second non-volatile memory stores compressor specific data including at least one of: suction pressure data; discharge pressure data; suction temperature data; discharge temperature data; electrical current data; electrical voltage data; ambient temperature data; compressor motor temperature data; compression element temperature data; compressor bearing temperature data; oil temperature data; compressor control data. The local module communicates the compressor specific data to the remote module for storage in the database.
[0074] In other features, the second non-volatile memory stores refrigeration system data including at least one of: condenser temperature data; evaporator temperature data. The local module communicates the refrigeration system data to the remote module for storage in the database.
[0075] In other features, the second non-volatile memory stores compressor fault history data. The local module communicates the compressor fault history data to the remote module for storage in the database.
[0076] Additionally, a compressor performance evaluation method is provided for a remote module in communication with a plurality of local modules. The method includes, for each local module, accessing a first non-volatile memory associated with a compressor using a processor associated with a second non-volatile memory or an operating memory, and storing compressor data from the second non-volatile memory or the operating memory in the first non-volatile memory. The method also includes, for the remote module, accessing the compressor data in each first non-volatile memory, storing the compressor data in a database, and accessing the database to evaluate compressor performance.
[0077] In other features, the accessing the compressor data in each first non-volatile memory includes accessing the compressor data with a computer network connection.
[0078] In other features, for the remote module, the accessing the compressor data includes accessing at least one of: compressor model type data; compressor serial number data; compressor capacity data; compressor operating coefficient data comprising numerical constants associated with said compressor and used to calculate compressor operating data.
[0079] In other features, for the remote module, the accessing the compressor data includes accessing at least one of: compressor bill of materials data; compressor build sheet data; compressor build date data; compressor build plant data; compressor build shift data; compressor build assembly line data; compressor inspector data.
[0080] In other features, for the remote module, the accessing the compressor data includes accessing at least one of: compressor energy efficiency ratio data; compressor low voltage start data; compressor wattage data; maximum compressor electrical current data; compressor refrigerant flow data.
[0081] In other features, for the remote module, the accessing the compressor data includes accessing at least one of: compressor installation location data; compressor installation date data; compressor installer data; compressor purchase location data.
[0082] In other features, for the remote module, the accessing the compressor data includes accessing at least one of: compressor repair date data; compressor repair type data; compressor repaired parts data; compressor service technician data.
[0083] In other features, for the remote module, the accessing the compressor data includes accessing at least one of: suction pressure data; discharge pressure data; suction temperature data; discharge temperature data; electrical current data; electrical voltage data; ambient temperature data; compressor motor temperature data; compression element temperature data; compressor bearing temperature data; oil temperature data; compressor control data.
[0084] In other features, for each local module, the method further includes storing refrigeration system data from the second non-volatile memory or the operating memory in the first non-volatile memory. For the remote module, the method further includes accessing the refrigeration system data in each first non-volatile memory and storing the refrigeration system data in the database.
[0085] In other features, for the remote module, the accessing the refrigeration system data includes accessing at least one of condenser temperature data and evaporator temperature data.
[0086] In other features, for the remote module, the accessing the compressor data includes accessing compressor fault history data.
[0087] Additionally, a method is provided including providing a warranty for a compressor having a non-volatile memory; receiving a claim under the warranty; examining data stored in the non-volatile memory; and responding to the claim based on the examining.
[0088] In other features, the examining the data stored in the non-volatile memory includes examining the non-volatile memory embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0089] In other features, the examining the data stored in the non-volatile memory includes examining the non-volatile memory embedded in a connector block that provides an electrical connection between an interior and an exterior of the compressor.
[0090] In other features, the examining the data stored in the non-volatile memory includes examining the non-volatile memory in an RFID device.
[0091] In other features, the providing the warranty includes providing terms by which the compressor may be replaced or repaired.
[0092] In other features, the providing the warranty includes defining misuse of the compressor. The responding to the claim includes determining compressor misuse based on the data and the warranty and refusing to replace or repair the compressor when the data indicates compressor misuse.
[0093] In other features, the defining misuse includes defining an allowable operating range for the compressor and wherein the determining compressor misuse includes comparing the data with the allowable operating range.
[0094] In other features, the defining the allowable operating range includes defining at least one of: a refrigerant level range, a refrigerant pressure range, a refrigerant temperature range, an electrical current range, an electrical voltage range, an ambient temperature range, a compressor motor temperature range, a compressor bearing temperature range, and an oil temperature data range.
[0095] In other features, the providing the warranty includes defining misuse of the compressor. The responding to the claim includes determining compressor misuse based on the data and the warranty and replacing or repairing the compressor when the data does not indicate compressor misuse.
[0096] In other features, the responding to the claim includes refusing to replace or repair the compressor when the data indicates that the compressor is functioning.
[0097] In other features, the responding to the claim includes determining a cause of a compressor malfunction based on the examining and repairing the compressor based on the determining.
[0098] In other features, the examining the data includes examining at least one of: compressor model type data; compressor serial number data; compressor capacity data; compressor operating coefficient data comprising numerical constants associated with the compressor and used to calculate compressor operating data.
[0099] In other features, the examining the data includes examining at least one of: compressor bill of materials data; compressor build sheet data; compressor build date data; compressor build plant data; compressor build shift data; compressor build assembly line data; compressor inspector data.
[0100] In other features, the examining said data includes examining at least one of: compressor energy efficiency ratio data; compressor low voltage start data; compressor wattage data; maximum compressor electrical current data; compressor refrigerant flow data.
[0101] In other features, the examining the data includes examining at least one of: compressor installation location data; compressor installation date data; compressor installer data; compressor purchase location data.
[0102] In other features, the examining the data includes examining at least one of: compressor repair date data; compressor repair type data; compressor repaired parts data; compressor service technician data.
[0103] In other features, the examining the data includes examining at least one of: suction pressure data; discharge pressure data; suction temperature data; discharge temperature data; electrical current data; electrical voltage data; ambient temperature data; compressor motor temperature data; compression element temperature data; compressor bearing temperature data; oil temperature data; compressor control data.
[0104] In other features, the examining the data includes examining at least one of: condenser temperature data; evaporator temperature data.
[0105] In other features, the examining the data includes examining compressor fault history data.
[0106] Additionally, a method is provided including: warranting a compressor having a non-volatile memory; receiving a claim for repair or replacement of the compressor; accessing data stored in the non-volatile memory to determine if the compressor was misused; denying the claim for repair or replacement of the compressor when the data indicates that the compressor was misused; and replacing or repairing the compressor when the data indicates that the compressor was not misused.
[0107] In other features, the accessing the data in the non-volatile memory includes accessing the non-volatile memory embedded in the compressor or affixed to the compressor in a tamper-resistant housing.
[0108] In other features, the accessing the data in the non-volatile memory includes accessing the non-volatile memory embedded in a connector block that provides an electrical connection between an interior and an exterior of the compressor.
[0109] In other features, the accessing the data in the non-volatile memory includes accessing the non-volatile memory in an RFID device.
[0110] In other features, the warranting the compressor includes defining compressor misuse.
[0111] In other features, the defining the compressor misuse includes defining an allowable operating range for the compressor.
[0112] In other features, the defining said allowable operating range includes defining at least one of: a refrigerant level range, a refrigerant pressure range, a refrigerant temperature range, an electrical current range, an electrical voltage range, an ambient temperature range, a compressor motor temperature range, a compressor bearing temperature range, and an oil temperature data range.
[0113] In other features, the accessing the data stored in the non-volatile memory to determine if said compressor was misused includes comparing the data with the allowable operating range and determining if the compressor was misused based on the comparison.
[0114] 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
[0115] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
[0116] FIG. 1 is perspective view of a compressor in accordance with the present teachings;
[0117] FIG. 2 is a perspective view of a protection and control system attached to a compressor in accordance with the present teachings;
[0118] FIG. 3 is an exploded view of a protection and control system and compressor memory system in accordance with the present teachings;
[0119] FIG. 4 is a schematic view of processing circuitry of a protection and control system in accordance with the present teachings;
[0120] FIG. 5 is a flow chart illustrating a data access control algorithm for a compressor memory system in accordance with the present teachings;
[0121] FIG. 6 is a schematic representation of a compressor information network in accordance with the present teachings; and
[0122] FIG. 7 is a flow chart illustrating a warranty administration method in accordance with the present teachings.
DETAILED DESCRIPTION
[0123] 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.
[0124] As used herein, the terms module, control module, and controller refer to one or more of the following: an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, or other suitable components that provide the described functionality. Further, as used herein, computer-readable medium refers to any medium capable of storing data for a computer. Computer-readable medium may include, but is not limited to, CD-ROM, floppy disk, magnetic tape, other magnetic medium capable of storing data, memory, RAM, ROM, PROM, EPROM, EEPROM, flash memory, punch cards, dip switches, or any other medium capable of storing data for a computer.
[0125] A protection and control system may monitor operating signals generated by compressor or refrigeration system sensors and determine compressor or refrigeration system operating data. The protection and control system may be of the type disclosed in assignee's commonly-owned U.S. patent application Ser. No. 11/059,646, Publication No. 2005/0235660, filed Feb. 16, 2005, the disclosure of which is incorporated herein by reference. It is understood, however, that other suitable systems may be used.
[0126] The protection and control system may be communicatively connected with a compressor and physically mounted on, but separable from, the compressor. The protection and control system may be physically separable from the compressor insofar as the protection and control system may be removed or separated from the compressor. For example, the protection and control system may be replaced or repaired and then re-mounted to the compressor.
[0127] The protection and control system may monitor compressor and/or refrigeration system operation. For example, the protection and control system may determine an operating mode for the compressor and may protect the compressor by limiting operation when conditions are unfavorable. Further, the protection and control system may determine whether compressor or refrigeration system faults have occurred.
[0128] With reference to FIGS. 1 to 4 , a compressor 10 may include a generally cylindrical hermetic or semi-hermetic shell 12 with a welded or bolted cap 14 at a top portion and a welded or bolted base 16 at a bottom portion. The cap 14 and base 16 may be fitted to the shell 12 such that an interior volume 18 of the compressor 10 is defined. The cap 14 may be provided with a discharge fitting 20 , while the shell 12 may similarly be provided with an inlet fitting 22 , disposed generally between the cap 14 and base 16 . A terminal box 30 with a terminal box cover 32 may be attached to the shell 12 .
[0129] The terminal box 30 may house the protection and control system 34 . The protection and control system 34 may have a protection and control system housing 36 and an integrated circuit (IC) 40 with processing circuitry 42 . The protection and control system 34 may be a module and may include processing circuitry 42 that may include a data processing means such as a processor 39 . The processor 39 may be a central processing unit (CPU) or a microprocessor. The processing circuitry 42 may also include random access memory (RAM) 41 and a non-volatile memory such as a read only memory (ROM) 43 . Alternatively, the data processing means may be implemented by an application specific integrated circuit (ASIC), an electronic circuit, a combinational logic circuit, or other suitable components that may provide the described functionality.
[0130] The protection and control system 34 may operate according to an operating program stored in the ROM 43 to perform in the manner described herein. The RAM 41 may function as an operating memory during operation of the protection and control system 34 . The processor 39 may access both the RAM 41 and the ROM 43 .
[0131] The protection and control system housing 36 may include a housing face portion and a housing back portion. The protection and control system 34 may be matingly received by a hermetic connector block 44 , which may be located within the terminal box 30 and fixedly attached to the compressor shell 12 . The hermetic connector block 44 may maintain the sealed nature of the compressor 10 while allowing power to be delivered to the compressor motor (not pictured) via power leads 47 as discussed in more detail below. The protection and control system 34 may be mounted to the shell 12 using two studs 49 which may be welded or otherwise fixedly attached to the shell 12 .
[0132] An embedded memory system 45 may include non-volatile memory 46 embedded within the compressor 10 . Specifically, the non-volatile memory 46 may be embedded within the hermetic connector block 44 . The memory system 45 may include a memory connector 48 interfaced with the non-volatile memory 46 . The non-volatile memory 46 may contain compressor specific data including, for example, numerical constants corresponding to the compressor model, type, and capacity. In other words, certain compressor pedigree or identification information may be stored in the non-volatile memory 46 .
[0133] The non-volatile memory 46 may remain within the hermetic connector block 44 , attached to or embedded within the compressor 10 , for the entire operating life of the compressor 10 . In this way, the compressor specific data may remain with the compressor 10 , stored in the non-volatile memory 46 , regardless of whether the compressor is moved to a different location, returned to the manufacturer for repair, or used with different protection and control systems.
[0134] Alternatively, the non-volatile memory 46 may be located in a tamper resistant housing elsewhere on or in the compressor 10 . For example, the non-volatile memory 46 may be in a tamper resistant housing embedded within, or attached to, the terminal box 30 or terminal box cover 32 . In addition, the non-volatile memory 46 may be embedded within the compressor shell 12 , or located within the interior volume 18 of the compressor 10 . The non-volatile memory 46 may be located at any suitable location that is generally inaccessible to a user, customer, repair person, or technician. The tamper resistant housing may include a sealed package affixed, adhered, or otherwise attached to the compressor 10 and configured to house the non-volatile memory in an inaccessible and protected fashion. Additionally, the non-volatile memory 46 may be located within the protection and control system 34 on the processing circuitry 42 .
[0135] The non-volatile memory 46 may be in-molded in a compressor component, such as the hermetic connector block 44 , the terminal box 30 , terminal box cover 32 , or other suitable component for maintaining the non-volatile memory 46 in an isolated and tamper resistant manner. In this way, the non-volatile memory 46 may remain with the compressor 10 for the operating life of the compressor 10 .
[0136] The hermetic connector block 44 may be configured with a memory connector 48 in communication with the non-volatile memory 46 . In this way, the non-volatile memory 46 may be read from, or written to, via the memory connector 48 . As shown in FIG. 3 , the memory connector 48 may include an eight pin connector. However, other connector configurations, with more or less pins, may be utilized. Further, other types of connectors may be utilized to provide an interface with the non-volatile memory 46 . For example, a serial data connection may be made with the non-volatile memory 46 . Additionally, a wireless device, such as an RFID device, may be used to communicate with the non-volatile memory 46 .
[0137] As an example, the non-volatile memory 46 may be a two kilobyte or four kilobyte erasable programmable read-only memory (EPROM) chip or an electrically erasable programmable read only memory (EEPROM) chip. Other types and other sizes of memory devices may be utilized including flash memory, magnetic media, optical media, or other non-volatile memory suitable for storing data. Additionally, an RFID device may be used. The RFID device may include non-volatile memory and may wirelessly communicate data. If an RFID device is used, the memory connector 48 may be a wireless data communication device that allows communication with the RFID device.
[0138] As used herein, non-volatile memory is intended to refer to a memory in which the data content is retained when power is no longer supplied to it, such as an EPROM or EEPROM. Additionally, non-volatile memory may include a traditionally volatile memory configured with an independent source of power to retain data. For example, a random access memory (RAM) may be used and embedded within the compressor 10 with an independent power source, such as a battery with an expected battery life that is greater than the expected operating life of the compressor 10 .
[0139] The IC 40 may be configured with an IC connector 50 such that the IC connector 50 may be matingly received by the memory connector 48 when the protection and control system 34 is attached to the hermetic connector block 44 . In this way, the non-volatile memory 46 may communicate with the processing circuitry 42 , via the IC connector 50 and memory connector 48 . The processing circuitry 42 may read from or write to the non-volatile memory 46 .
[0140] The non-volatile memory 46 may receive electrical power from the memory connector 48 and the protection and control system 34 , or other device, connected to the memory connector 48 . In this way, the non-volatile memory 46 may not require an independent source of electrical power.
[0141] The hermetic connector block 44 may be configured with three power leads 47 electrically connected to internal compressor components, such as a compressor motor (not pictured). Three phase electrical power may be delivered to the compressor 10 via a power cord 52 received by the terminal box 30 . The power cord 52 may attach to the ends of three conductive studs 54 via apertures 37 on the face of the housing 36 . The hermetic connector block 44 may receive the three conductive studs 54 . Each of the three conductive studs 54 may be connected to a separate phase of the three phase electrical power delivered by the power cord 52 . At installation, the power leads 47 may be bent over, such that an aperture in each of the power leads may receive one of the three conductive studs 54 . In this way, the power leads 47 may be electrically connected to the conductive studs 54 and three phase electrical power may be delivered from the power cord 52 to the compressor 10 .
[0142] While delivery of three phase power to the compressor 10 is described, the compressor 10 may alternatively receive single phase power. Further, any other system for delivery of power to the compressor 10 may be used.
[0143] Electrical power may also be delivered to the IC 40 and processing circuitry 42 via at least one of the conductive studs 54 . While the compressor 10 may be powered by three phase electrical power, the IC 40 and processing circuitry 42 may be powered by single phase electrical power from one of the conductive studs 54 .
[0144] The processing circuitry 42 may receive various operating signals generated by compressor or refrigeration system sensors. The processing circuitry 42 may determine or derive compressor or refrigeration system operating data. Electrical current sensors 56 may be located on the IC 40 and may generate electrical current signals corresponding to the amount of electrical current drawn by the compressor 10 . The processing circuitry 42 may monitor the electrical current signals generated by the electrical current sensors 56 . Generally, the level of current drawn by the compressor corresponds to the present load on the compressor. The current drawn by the compressor 10 generally increases as the present load on the compressor 10 increases.
[0145] Additional compressor sensors may be located within the compressor shell 12 . Such internal compressor sensors may include a motor temperature sensor, a discharge line temperature sensor, a suction pressure sensor, or the like. Another hermetic connector block 58 may be fixedly attached to the compressor shell 12 and configured with conductive terminals 60 connected to each of the internal compressor sensors. The processing circuitry 42 may receive the operating signals generated by the internal compressor sensors. The processing circuitry 42 may also receive additional operating signals from additional system or compressor sensors external to the compressor 10 . Based on the various operating signals, the processing circuitry 42 may determine an operating mode for the compressor 10 , and may generate compressor or system fault alerts.
[0146] The protection and control system 34 may be configured with a communication terminal 62 connected to the processing circuitry 42 via an aperture 63 in the face of the housing 36 . The communication terminal 62 may be connected to a number of network/communication devices. As described in more detail below and in assignee's commonly-owned U.S. patent application Ser. No. 11/059,646, Pub. No. 2005/0235660, filed Feb. 16, 2005, the communication terminal 62 may be operable to connect to, and communicate with, a handheld computing device, a system controller, or other suitable communication/network device.
[0147] Referring now to FIG. 5 , a flow chart illustrating a data access control algorithm for a memory system 45 is shown. Prior to normal operation, the memory system 45 may be loaded with initialization data, including compressor specific data, in grouped steps 98 . When the compressor 10 is initially assembled and configured with the memory system 45 , the compressor manufacturer, for example, may load the memory system 45 with compressor specific data in step 100 . The compressor specific data may include manufacturing data related to the specific compressor 10 with which the memory system 45 is associated.
[0148] For example, the initialization data may include the compressor model, serial number, and capacity size. A bill of materials, i.e., the list of part numbers of all the individual components of the compressor, may also be loaded into the memory system 45 . The build sheet, or sequence of operations carried out in the assembly of the compressor 10 , may also be loaded. Data as to the date, shift, plant, assembly line, and inspector that built and inspected the compressor 10 may also be loaded.
[0149] Compressor specific data may also include test data information loaded into the memory system 45 by the compressor manufacturer. Test data may include an energy efficiency ratio, which relates the compressor's BTU's/Hr to input power in watts. Test data may also include a low voltage start number, which represents the lowest line voltage at which the compressor 10 may start. Test data may also include a Watts number, related to the electrical power that may be input to the compressor 10 . Test data may also include a maximum current drawn by the compressor 10 at maximum load. Test data may also include the amount of refrigerant flow under given test conditions.
[0150] Compressor specific data may also include compressor operating coefficient data. Each compressor 10 is associated with certain compressor-specific numerical constants to be utilized by the protection and control system 34 when making certain calculations and operating data determinations. For example, as disclosed in assignee's commonly-owned U.S. patent application Ser. No. 11/059,646, Pub. No. 2005/0235660, filed Feb. 16, 2005, the protection and control system 34 may utilize compressor-specific numerical constants to calculate data about other refrigeration system components.
[0151] For example, the protection and control system 34 may determine a condenser temperature or an evaporator temperature based on the following formula:
P = C 0 + ( C 1 × T COND ) + ( C 2 × T EVAP ) + ( C 3 × T COND 2 ) + ( C 4 × T COND × T EVAP ) + ( C 5 × T EVAP 2 ) + ( C 6 × T COND 3 ) + ( C 7 × T EVAP × T COND 2 ) + ( C 8 × T COND × T EVAP 2 ) + ( C 9 × T EVAP 3 ) , ( 1 )
[0152] where P is compressor power, T COND is condenser temperature, T EVAP is evaporator temperature, and C 0 to C 9 are constants that are specific to the particular compressor model and capacity size.
[0153] Likewise, the protection and control system may determine compressor capacity according to the following equation:
X = Y 0 + ( Y 1 × T COND ) + ( Y 2 × T EVAP ) + ( Y 3 × T COND 2 ) + ( Y 4 × T COND × T EVAP ) + ( Y 5 × T EVAP 2 ) + ( Y 6 × T COND 3 ) + ( Y 7 × T EVAP × T COND 2 ) + ( Y 8 × T COND × T EVAP 2 ) + ( Y 9 × T EVAP 3 ) ( 2 )
[0154] where X is compressor capacity, T COND is condenser temperature, T EVAP is evaporator temperature, and Y 0 to Y g are constants that are specific to the particular compressor model and size.
[0155] Numerical constants C 0 to C 9 and Y 0 to Y 9 , which are traditionally published by the compressor manufacturer and loaded into the protection and control system 34 at the time the compressor is installed in the field, may be preloaded into the nonvolatile memory 46 of the memory system 45 by the compressor manufacturer at the time the compressor 10 is built. In this way, compressor specific data is loaded into the memory system 45 , thereby decreasing the installation burden on the installer in the field and minimizing the chance for installation error.
[0156] Information related to the specific refrigeration system connected to a compressor may be loaded into the memory system 45 by a system manufacturer in step 102 . For example, the refrigeration system manufacturer may receive a compressor 10 configured with a memory system 45 that has been loaded by the compressor manufacturer with compressor specific information. The refrigeration system manufacturer may then use the compressor 10 as a component in a refrigeration system, with, for example, an evaporator or a condenser. The refrigeration system manufacturer may load refrigeration system information, such as component model and serial number information for the system components, such as the evaporator and the condenser, into the memory system 45 .
[0157] Installation data may be loaded into the memory system 45 by the installer at the time the compressor is installed at the field location in step 104 . As discussed above, the memory system 45 is configured with a memory connector 48 . In the field, the memory system 45 may be accessed by the installer with a handheld device connected directly to the memory connector 48 . Alternatively, the memory system 45 may be accessed after the protection and control system 34 is installed. In such case, the installer may access the memory system 45 with a handheld device connected to the communication terminal 62 of the protection and control system 34 . In this way, the memory system 45 is accessible by the handheld device, via the communication terminal 62 , processing circuitry 42 , IC connector 50 , and memory connector 48 . Similarly, the memory system 45 may be accessed by other devices connected to the communication terminal 62 of the protection and control system 34 .
[0158] Installation data loaded into the memory system 45 may include the installation location, the installation date, the installer's name, and the dealer from whom the compressor 10 was purchased. Additionally, subsequent to installation, if the compressor 10 is ever serviced, service information, such as a service description and a listing of replacement parts, may be loaded into the memory system 45 at that time in the same manner.
[0159] With continuing reference to FIG. 5 , once the compressor 10 has been installed at the field location, the compressor 10 may enter normal operation in grouped steps 106 . A normal operating cycle is generally shown in grouped steps 106 . During normal operation 106 , the compressor 10 may perform operating functions at step 108 . During normal operation, the protection and control system 34 may monitor operating signals generated by compressor or refrigeration system sensors and may generate compressor or refrigeration system operating data. The protection and control system 34 may determine an operating mode for the compressor 10 and may determine whether compressor or refrigeration system faults have occurred.
[0160] During normal operation, the protection and control system 34 may write operating data to the memory system 45 in step 110 . In a memory system 45 that utilizes a two kilobyte or four kilobyte EEPROM, operating data for the most recent two to three minutes of operation may be stored in the memory system 45 . Longer periods of operating data may be stored if a memory system 45 with a greater amount of memory is utilized. When the memory allocated for storing operating data is full, the protection and control system 34 may write over the oldest operating data first. Additionally, the protection and control system 34 may partition the memory allocated for storing operating data into discrete segments. When the allocated memory is full, the oldest segment may be erased and rewritten with more recent operating data.
[0161] Operating data written to the memory system 45 may include any number of predetermined signals and parameters monitored or generated by the compressor, the refrigeration system, or the protection and control system 34 . For example, operating data may include data related to electrical current drawn, compressor voltage, ambient temperature, discharge line temperature, intake line temperature, compressor motor winding temperature, compression element temperature, bearings temperature, oil temperature, discharge line pressure, intake line pressure, and the like. Operating data may also include refrigeration system data such as condenser temperature and evaporator temperature. Operating data may also include refrigeration system communication inputs, such as a refrigeration system call for cooling or heating, a defrost command, or the like.
[0162] Fault history data may also be stored in the memory system 45 . The protection and control system 34 may determine whether a compressor 10 or system fault has occurred in step 112 . When a fault has occurred, the protection and control system 34 may update the fault history data in the memory system 45 in step 114 . Fault history data may include information related to the date, time, and type, of the most recent faults. For example, a seven day fault history may be stored in the memory system 45 . Information related to the last fault, such as the last fault compressor motor temperature, last fault voltage or current, last fault oil level, last fault number of cycles, etc. may be stored in the memory system 45 .
[0163] In step 116 , the protection and control system 34 may determine whether a request for memory system data has been made by a device connected to the communication terminal 62 . When a device requests data from the memory system 45 , via the communication terminal 62 , the protection and control system 34 may retrieve the requested data from the memory system 45 and provide it to the requesting device via the communication terminal 62 in step 118 . The protection and control system 34 then loops back to step 108 .
[0164] In this way, compressor specific data, system data, installation data, and operating data may be stored in the memory system 45 and accessed by the protection and control system 34 , as well as any other devices connected to the protection and control system 34 via the communication terminal 62 .
[0165] The data stored in the memory system 45 may be used to evaluate compressor performance or refrigeration system performance. For example, by examining the data stored in the memory system 45 , operating data may be evaluated in light of the compressor model and capacity size, as well as in light of the installation location of the compressor. The data stored in the memory system 45 may provide insight into the operation of the compressor based on the various factors that may affect performance and based on the specific compressor specifications. In this way, the data stored in the memory system 45 may provide evaluation assistance when a new compressor is being considered for purchase or when a new compressor is being designed.
[0166] The protection and control system 34 may be connected to a network via the communication terminal 62 . In such case, the memory system 45 may be accessible to other devices connected to the network. The compressor specific data, system data, and operating data may then be used to diagnose the compressor, diagnose the refrigeration system, schedule maintenance, and evaluate compressor warranty claims.
[0167] Referring now to FIG. 6 , a compressor information network 150 is shown. The protection and control system 34 , or multiple protection and control systems 34 , may be connected to a network. The protection and control systems 34 may be connected to the network via the communication terminal 62 which is communicatively connected to the processing circuitry 42 . Alternatively, the protection and control system 34 may be connected to the network via a system controller 152 , such as a refrigeration system controller. Further, the protection and control system 34 may be connected to the network via a hand-held computing device 154 or other suitable network device. The protection and control system 34 may be connected to the internet 158 via a wired or wireless internet connection 160 .
[0168] The protection and control system 34 may be connected to a computer network such as the internet 158 . Further, the protection and control system 34 may be connected to a database server 156 via the internet 158 . The database server 156 may be a module configured to communicate with the protection and control systems 34 and with a computer information database stored in a computer readable medium 164 . In this way, the contents of the memory system 45 may be accessible to other devices connected to the network, including the database server 156 .
[0169] The database server 156 may collect information from the memory system 45 via a memory system information transaction initiated by the database server 156 , the protection and control system 34 , the system controller 152 , the hand-held computing device 154 , or other network device. The database server 156 may build a comprehensive compressor information database based on the contents of multiple memory systems 45 connected to the network. In this way, the database server 156 may store compressor information including compressor identity, location, operation history, service history, fault history, fault data, etc., for multiple compressors 10 connected to the network and located in multiple locations around the world.
[0170] The compressor information database may be used to evaluate compressor operation. The database may be used to improve future compressor or refrigeration system design, to improve field service technician training, and/or to determine trends related to certain similar environmental conditions. The database server information may also be used for asset management purposes as a tool to analyze sales and marketing activities. The information may also be shared with system manufacturers or system component manufacturers to assist in the design and implementation of refrigeration systems and system components. In other words, the database may provide compressor operation data, tied to geographic installation locations, compressor type and capacity, and other compressor specification data.
[0171] Referring now to FIG. 7 , information stored in the memory system 45 may be used during the administration of compressor warranty claims. A compressor may be covered by a manufacturer's warranty. The warranty may include the terms by which the compressor may be replaced or repaired. The warranty often includes an expiration date. Further, the warranty may include terms by which compressor misuse and other warranty voiding events may be defined. The warranty voiding events may include certain misuse circumstances. For example, the warranty may include certain acceptable operating ranges, including a refrigerant level range, a refrigerant pressure range, a refrigerant temperature range, an electrical current range, an electrical voltage range, an ambient temperature range, a compressor motor temperature range, a compressor bearing temperature range, and an oil temperature data range. If the user ignores a misuse condition for a certain period of time, and allows the compressor to operate under misuse circumstances, the warranty may be voided.
[0172] When a compressor fault occurs, a claim may be made under the compressor manufacturer's warranty that the compressor 10 , or a compressor component, is defective or otherwise subject to repair by the manufacturer under the terms of the warranty. In such case, the owner of the compressor may return the compressor 10 to the manufacturer with the claim indicating the reason for return. The compressor manufacturer may receive the warranty claim information in step 200 .
[0173] When a compressor 10 with a memory system 45 is returned to the manufacturer under a warranty claim, the manufacturer may access the memory system 45 and examine the fault history data and operating data. The data from the memory system 45 may be retrieved by the compressor manufacturer in step 202 . By examining the memory system data, the manufacturer may confirm whether the compressor 10 was the cause of the fault. When refrigeration system data is stored in the memory system 45 , the manufacturer may determine that a non-compressor system component, like a condenser or evaporator, was the cause of the fault complained of in the warranty claim. In such case, the manufacturer may be able to quickly determine that the compressor 10 is not defective or in need of repair. The compressor manufacturer may determine whether a non-compressor component was at fault in step 204 .
[0174] In addition, by examining the contents of the memory system 45 , the manufacturer may be able to determine whether a warranty voiding event occurred prior to the compressor fault. For example, the memory system 45 may reveal that a low refrigeration fluid condition was ignored for a period of time prior to the compressor fault occurring. In such case, the manufacturer may determine that the warranty claim is void due to the compressor owner ignoring the low refrigeration fluid condition. The compressor manufacturer may determine whether a warranty invalidating event has occurred in step 206 .
[0175] When the compressor 10 is at fault in step 204 , and when a warranty invalidating event has not occurred in step 206 , the compressor manufacturer may repair or replace the compressor under the terms of the warranty in step 208 . When a non-compressor component is at fault, or when a warranty invalidating event has occurred in steps 204 or 206 , the compressor manufacturer may notify the compressor owner in step 210 .
[0176] When the memory system 45 is remotely accessible to the manufacturer via a network device, as discussed above, the manufacturer may be able to make a preliminary warranty claim determination prior to the compressor 10 being sent to the manufacturer. For example, prior to disconnecting the compressor from the system for return to the manufacturer, the compressor owner may simply notify the manufacturer that it believes a problem covered by the warranty has occurred. The manufacturer may then access the compressor's memory system 45 and examine the memory system data to make a preliminary determination as to the warranty claim. When a warranty voiding event has occurred, the manufacturer may inquire with the compressor owner as to the occurrence of the warranty voiding event. The compressor manufacturer may also be able to make a preliminary determination as to whether the problem complained of originated with a non-compressor component fault. Such a preliminary determination will save time and money previously lost due to unnecessary or uncovered warranty claims.
[0177] During a warranty claim, if it is determined that the compressor failure was due to failure of a non-compressor system component based on the data contained in the memory system 45 , this data can be shared with the manufacturer of the non-compressor system component. In this way, data and information may be shared with other component and system manufacturers to assist in the administration of their warranty claims as well.
[0178] The description is merely exemplary in nature and, thus, variations are intended to be within the scope of the teachings. Such variations are not to be regarded as a departure from the spirit and scope of the teachings.
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A compressor information network includes a remote module operable to communicate with a plurality of local modules. Each local module includes a processor and a first non-volatile memory associated with the processor. The processor communicates with the first non-volatile memory and the second non-volatile memory associated with a compressor. The remote module includes a database of information copied from the second non-volatile memory.
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This invention relates to fountains, faucets and other fixtures that supply water or other liquids and, in particular, to such fixtures that are provided with special effects.
BACKGROUND OF THE INVENTION
Amusement parks and theme parks provide a variety of rides and shows for the amusement and entertainment of their patrons. Some patrons visit the parks for the exhilarating rides, others come to view the special effects associated with the shows. Many simply appreciate the pleasurable diversions they encounter during their visit.
To make their patrons' visits more comfortable, the parks provide drinking fountains, restrooms and other facilities on the park grounds. These facilities, however, typically are not part of the show and do not incorporate the special effects that are associated with other features in the park. It should be appreciated, therefore, that adding special effects to drinking fountains and the like, would serve as another source of entertainment and novelty to the patrons.
Lighting effects have been previously known in connection with fountains and water faucets. See, e.g., U.S. Pat. Nos. 4,749,126 and 4,901,922 to Kessener et al. In these patents, a light is introduced into the fluid stream and may be controlled to provide various visual effects. The latter patent also describes the use of a piezoelectric device for producing sound waves in the sonic or ultrasonic region. The sound waves are created, however, for the purpose of producing vibrations in the liquid medium, resulting in a particular visual effect. Neither of these patents discloses a fountain, faucet or other fixture having audible sounds that are intended to be heard by the patron.
From the above, it will be appreciated that there is still a need for a drinking fountain, faucet or other fixture that incorporates sound effects with the use of the fixture. The present invention satisfies this need.
SUMMARY OF THE INVENTION
The present invention is embodied in a fountain, faucet or other fixture that has associated therewith a sound system that plays audible sound upon operation of the fixture by a patron. For example, in one preferred embodiment, a guest depresses a push button on a drinking fountain to get a drink of water. A sound effect can occur at the instant that the button is depressed, after an electronically timed delay, when the button is released or when triggered by some other event or sensor (e.g., a motion detector). Possible sound effects include gurgling, a voice saying "ahhhh", or any number of other sounds, sound effects, or music.
The fixture of the present invention includes a spout for delivering pressurized fluid, a human actuatable valve for controlling the delivery of the pressurized fluid from the spout, and an audio system having a speaker. A feature of the invention is that the speaker may be acoustically coupled to a drain pipe of the fixture such that the sound emanates from the drain. An acoustic pipe having the speaker mounted at one end thereof may be connected to the drain pipe in such a way as to provide a sound passage from the speaker through the acoustic pipe into the drain pipe, while minimizing the possibility of drain water entering the speaker.
A further feature of the present invention is that an audio system may be used that is responsive to actuation of the valve such that it plays an audible sound from the speaker in response to the actuation. In addition, the audio system may include a prepared sound clip that is played back in response to a preselected mode of actuation of the valve. For example, the sound clip may be triggered when the valve is turned on by a patron or, alternatively, when the valve is turned off. Also, the sound clip may be triggered at any predetermined time after the valve is actuated.
Another feature of the present invention is that the audio system may include many prepared sound clips in sequence such that each time the valve is actuated a different sound clip is played. This provides an additional element of surprise and novelty to those who return at a later time to use the fountain, faucet or fixture.
Other features and advantages of the present invention will become apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a drinking fountain combined with a sound effects system;
FIG. 2 is a functional block diagram of the drinking fountain and sound effects system of FIG. 1; and
FIG. 3 is a functional block diagram of a simplified drinking fountain and sound effects system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A fixture 10 combined with a sound effects system 12 is shown schematically in FIG. 1. In the preferred embodiment, the fixture is a conventional drinking fountain 14 having a water supply line 16, a spout 18, a basin 20, a push button 22 and a drain line 24. Upon actuating the push button 22, a valve 26 is activated (see FIGS. 2 and 3), permitting water to flow from the spout 18. While the button is depressed, a patron may take a drink, fill a container, permit others to drink, etc. When done, the button is released and the valve shuts off the water supply to the spout. The basin 20 collects the unconsumed water and directs it to the drain line 24. In one embodiment (FIG. 2), the valve is actuated by a solid state relay 28. A conventional solid state or relay based control system 30 may be used to trigger the solid state relay when the button 22 is pressed. In a simplified embodiment (FIG. 3), the push button 22 is depressed to close a contact, pole 1, which completes an electrical circuit to trigger the valve 26.
Although a drinking fountain is described in the preferred embodiment, it will be appreciated that the sound effects system to be described below may be used with other fixtures, such as a faucet for a sink or tub, a sewer drain, a hose or other types of fountains. Also, actuating devices for actuating the valve, other than a push button, may be used with the present invention. For example, there are a variety of valve types known to those in the art for turning a faucet on and off. Additionally, motion detection systems or other similar systems may be used, which do not require the patron to actually contact the fixture to actuate the valve.
With reference to FIGS. 1 and 2, the sound effects system 12 includes the control system 30 and an audio system 32. The audio system 32 includes an electronic solid state analog or digital audio storage/playback unit. One preferred system is commercially available from the company "360 Systems" of Tarzana, Calif. under the name "Quadfile." The audio system may be powered by a VDE-Grade power transformer (not shown) that provides a power supply for low voltage items, e.g., 13.5 VDC 7A/10A PK.
In one preferred embodiment, the audio system 32 has at least two separate sound sources, a background sound source 34 and a sequential sound source 36. The background sound source may continuously run a musical piece, such as from a tape or disk or preferably EPROM chips. For example, ten 4 MEG EPROMS may be used to play a musical piece loop that lasts up to 6 minutes at 10 KHZ BW or that lasts up to 4 minutes at 15 KHZ BW. The sequential sound source runs a series of sound effects clips and may similarly be a device such as a tape, disk or EPROM chips. Each sound effects clip may have one of a variety of sounds, such as human sounds (gurgling, gulping, gargling), spoken words ("That's cold"), music clips, special effects sounds or any other audible effect desired.
Typical commercial audio systems provide many desirable options for controlling the sound sources. For example, the background sound source may be operated in a loop mode, which runs the tape, disk or EPROM chips continuously until desired otherwise. A "run at boot" command may also be operated to start the musical piece for the background sound source when the audio system is turned on. Another option would restart the background sound source music piece when the push button for the fixture is actuated ("restart on RCV CMD"). Manual controls 38 are provided for turning the background sound source on and off.
With regard to the sequential sound source, a "pause" mode may be used wherein each of the sound effects clips are separated from one another by a pause command, such that upon receiving a start signal, one sound effects clip is played. The pause command then prevents further clips from being played until another start signal is received. The sound effects clips may be arranged such that the full sequence is repeated upon completion of the last sound effects clip.
The sequential sound system may also have a "run on command only" option. When connected to a suitable relay at the push button of the drinking fountain, this option results in a patron activating a sound effects clip when he or she takes a drink from the drinking fountain. Another desirable option is a "message status out" feature. This is a signal to the control system 30, which identifies whether a sound effects clip is playing or not. This signal may then be used by the control system to ignore repeated actuations of the push button by a patron during the time that a sound effects clip is already being played. Manual controls 40 are provided for turning the sequential sound source on and off.
When activated, the background and sequential sound sources 34, 36 transmit electrical signals to a speaker system 42. The speaker system converts the signals into acoustical energy that is audible to nearby patrons. In the preferred embodiment, the speaker system for the background and sequential sound sources includes a compression driver 44 and a woofer 46.
In particular, a signal 48 from the background sound source 34 is split into a first signal 50 and a second signal 52. The first signal 50 passes through a mute circuit 54, a summing amp 56, a high pass filter 58, and a mid-high amplifier 60 before reaching the compression driver 44. The second signal 52 passes through a low pass filter 62 and a bass amplifier 64 before reaching the woofer 46. A signal 66 from the sequential sound source 36 is transmitted to the summing amp 56 where it can be mixed with the first signal 50 from the background sound source 34, then transmitted to the high pass filter 58 and mid-high amplifier 60 before entering the compression driver 44. The amplifiers 60, 64 may be provided with controls 68 to adjust the volume of the sound. The mute circuit 54 permits the first signal 50 from the background sound source to be suppressed, if desired, as will be explained below.
All of the components set forth above are generally available commercially. The mute circuit 54 is preferably a relay or other electrically-controlled switching device. The summing amp 56 is preferably a general purpose audio mixing circuit. A DC power supply (not shown), e.g., +/-15 VDC 100 MA analog power, may be used to power the summing amp. The high pass filter 58 and low pass filter 62 may be general purpose electronic filters sometimes referred to as "tone" controls. The high pass filter may be, for example, approximately 2.4 KHz and the low pass filter may be approximately 3 KHz. The mid-high amplifier 60 and bass amplifier 64 may be general purpose audio amplifiers and may be powered by the VDE-Grade power transformer, referred to above in connection with the audio system 32. Suitable power for the amplifiers would be 25 watts. The compression driver 44 may be a general purpose mid-range or mid-to-high frequency audio compression driver. The woofer 46 may be a general purpose low frequency speaker.
The sound system components may be located in an enclosure (not shown) under the basin of the drinking fountain. This permits ready access to the manual controls of the audio system and to the volume controls of the amplifiers.
In the preferred embodiment, the compression driver 44 is mounted to the drain pipe 24 of the drinking fountain 14 and directs sound into the drain pipe 24. With reference to FIG. 1, an acoustic pipe 70, having a first end 72 and a second end 74, acoustically couples the driver 44 to the drain pipe 24. In particular, the driver is mounted to the first end 72 of the acoustic pipe and the second end 74 of the acoustic pipe is coupled to the drain pipe, providing an unobstructed sound path through the acoustic pipe into the drain pipe. Preferably, the angle of orientation between the acoustic pipe and the drain pipe is such that the driver directs sound waves into a portion 76 of the drain pipe that goes to the basin 20. Thus, when a sound effects clip is played, the sound will emanate from the opening where the basin 20 meets the drain pipe 24. It is also desirable that the acoustic pipe 70 be located above the drain pipe to minimize the amount of water that may come into contact with the driver. Alternatively, a water isolation membrane 75, such as a thin plastic diaphragm, may be fixed in the acoustic pipe to prevent passage of liquid from the drain pipe to the driver. For example, the acoustic pipe may include two pieces, with one piece having the membrane placed over an end of it and then press fit into the other piece.
The acoustic pipe and the drain pipe may be made of metal or plastic. The acoustic pipe may be connected to the drain pipe by a "tee" adapter. The driver may be connected to the acoustic pipe by a conventional threaded pipe connection.
As mentioned above, the control system 30 may be a solid state or relay-based system that controls actuation of the valve and certain operations of the audio system 32. With respect to the valve, the control system sends a valve open command to the solid state relay 28 when a patron depresses the push button on the drinking fountain (FIG. 2). This energizes the solenoid valve. Releasing the push button, deenergizes the valve.
When the patron pushes the button, the control system may also be designed to send a pulse to the sequential sound source 36, causing it to run a sound effects clip. Pressing the push button can also trigger the mute circuit 54, which suppresses the background sound source 34 while a sound effects clip is being played. Alternatively, the control system can be designed to trigger the sequential sound system and mute circuit upon release of the push button or after any desired time delay.
The control system can also be designed to continuously monitor the "message status out" signal of the audio system 32, previously mentioned, to confirm whether or not a sound effects clip is being played. If a sound effects clip is being played, the control system ignores depressions of the button that occur during the clip's playback and continues to mute the background music. If a sound effects clip is not being played, the control system will permit another pulse to be transmitted to the sequential sound source, which starts the next clip in sequence. The design of a control system such as described above is well known to those skilled in the art and need not be described in detail herein.
With reference to FIG. 3, a preferred simplified embodiment of the sound effects system is shown. In this embodiment, the push button 22 closes two contacts, at pole 1 and pole 2. Closure at pole 1 completes a 24 VDC circuit to activate the solenoid valve 26 to supply water to the spout of the fixture. Closure at pole 2 triggers the audio system 106. In this embodiment, the audio system is preferably an electronic solid state analog or digital audio storage/playback unit, such as that sold by the company "360 Systems" under the name "Series 1000." This type of audio system includes a sequential sound source that can run a series of sound effects clips, such as from a tape, disk or EPROM chips. For example, the "Series 1000" audio system accepts eight 4 MEG EPROMS to play sound clips that together last up to three minutes. Each clip may also be provided with a delay such that the audible portion of the sound effects clip will not be heard until a predetermined amount of time has passed after the push button has been pressed. The delay permits water to begin flowing into the drain before the sound effect is played.
In this embodiment, the audio system itself is programmable such that it may be triggered to play one sound clip at a time upon actuation of the push button and to ignore repeated actuations of the push button while a sound clip is playing. This eliminates the necessity of the separate control system 30 shown in FIG. 2. When activated, the sequential sound source transmits an electrical signal to a speaker 108, which converts the signal into acoustical energy that is audible to nearby patrons. As in the embodiment shown in FIG. 2, the speaker may be mounted to the drain pipe of the drinking fountain and directs sound into the drain pipe. The simplified embodiment also omits the background music source, thus eliminating the need for the mute circuit and the summing amp. The low pass filter, bass amplifier and woofer may also be eliminated in this design.
It should be appreciated from the foregoing description that the present invention combines a drinking fountain, faucet or other fixture with a sound effects system. The sound effects may be pre-recorded or pre-produced and played back when a person uses the fixture. Thus, the invention includes an audio playback system that is cued to the use of the fixture. Alternatively, the sound effects system may simply be a speaker connected to any audio source, such as a radio or microphone. A real time synthesis unit may also be used. The invention also concerns the connection of the speaker to the drain pipe such that the sound effects emanate from the drain of the fixture. The present invention is particularly suitable in amusement parks and theme parks, where it is likely to bewilder those who use it for the first time and amuse and entertain those who have tried it before.
Although the invention has been described in detail with reference only to the preferred embodiment, those having ordinary skill in the art will appreciate that various modifications can be made without departing from the invention. Accordingly, the invention is defined with reference to the following claims:
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A drinking fountain having a spout, a human actuatable valve for controlling the flow of water from the spout, a basin for collecting the water and a drain pipe. An audio system includes a speaker wherein the speaker is mounted to the drain pipe in such a manner as to direct soundwaves into the drain pipe. The audio system is responsive to actuation of the valves such that it plays an audible sound from the speaker in response to the actuation. The audio system may include a sequential sound source having a plurality of sound clips that are playable in response to respective actuations of the valve.
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TRADEMARKS
[0001] IBM® is a registered trademark of International Business Machines Corporation, Armonk, N.Y., U.S.A. Other names used herein may be registered trademarks, trademarks or product names of International Business Machines Corporation or other companies.
BACKGROUND OF THE INVENTION
[0002] 1 . Field of the Invention
[0003] This invention relates to printed circuit board fabrication, and particularly to methods and systems for reducing noise coupling in high-speed digital systems.
[0004] 2. Description of Background
[0005] FIG. 1 illustrates a conventional printed circuit board having a core layer 105 having a return current reference layer 106 , a pre-preg layer 110 and a core insulator layer 120 having a return current reference layer 115 and a number of single layer nets 125 . Cross-talk noise coupling on adjacent nets 125 (i.e., victim nets) can result in poor signal integrity in high speed system. The effects of cross-talk noise can be intensified with increased signal speeds.
[0006] Currently, many techniques have been proposed to reduce noise and cross-talk coupling, but often rely on complex digital signal processing (DSP) techniques and filtering algorithms to achieve noise isolation.
[0007] There is currently a need to detect and implement, and at the same time, achieve high noise isolation.
SUMMARY OF THE INVENTION
[0008] Exemplary embodiments include a printed circuit board apparatus having reduced noise coupling, the apparatus including a core layer having an upper and lower surface, the upper and lower surface each including a copper sheet layer, a pre-preg layer having an upper surface and a lower surface, the upper surface of the pre-preg layer coupled to the lower surface of the core layer, a core insulating layer having an upper surface and a lower surface, the upper surface of the core insulating layer coupled to the lower surface of the pre-preg layer, a return current reference layer disposed on the lower surface of the core insulator layer and high-speed signal traces disposed on the upper surface of the core insulating layer, each of the high speed signal traces disposed on a pedestal defined by a section of the pre-preg layer and the core insulating layer, each pedestal being separated by an air gap disposed between adjacent pedestals.
[0009] Further exemplary embodiments include a printed circuit board fabrication method, including etching a plurality of high speed signal traces onto a core insulating layer, forming trenches on respective sides of the plurality of high speed signal traces, thereby removing insulating material adjacent to the plurality of high speed signal traces and forming pedestals having remaining insulating material, the plurality of high speed signal traces disposed on and coupled to the remaining insulating material, coupling pre-preg material on the high speed signal traces, removing the pre-preg material adjacent the trenches, thereby retaining the pre-preg material aligned with the high speed signal traces, wherein a width of a trench portion disposed in the pre-preg material is greater than a width of a trench portion disposed in the core insulating layer and heating and pressing a core layer to the pre-preg layer, and heating and pressing the pre-preg layer to the core insulating layer, wherein the plurality of high-speed signal traces disposed on an upper surface of the core insulating layer, each of the plurality of high speed signal traces disposed on a pedestal defined by a section of the pre-preg layer and the core insulating layer, each pedestal being separated by an air gap disposed between adjacent pedestals.
[0010] System and computer program products corresponding to the above-summarized methods are also described and claimed herein.
[0011] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention ale described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
TECHNICAL EFFECTS
[0012] As a result of the summarized invention, technically we have achieved a solution which cross-talk noise coupling from adjacent nets on PCBs is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0014] FIG. 1 illustrates a conventional printed circuit board;
[0015] FIG. 2 illustrates a PCB apparatus that reduces cross-talk for single-ended nets in accordance with exemplary embodiments,
[0016] FIG. 3 illustrates a PCB apparatus that reduces cross-talk for differential nets in accordance with exemplary embodiments;
[0017] FIG. 4 illustrates a flowchart of a printed circuit board fabrication method for reducing cross talk in accordance with exemplary embodiments; and
[0018] FIG. 5 illustrates a graph of noise coupling simulation results.
[0019] The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In exemplary embodiments, the systems and methods described herein reduce cross-talk coupling or noise induction created by capacitive and inductive coupling. Capacitive coupling occurs due to the presence of dielectric medium. In exemplary embodiments, the systems and methods described herein include adjacent printed circuit board (PCB) stripline structures that are surrounded with air. A PCB trace on an inner layer is supported in an air cavity by a pedestal of insulating material. The pedestal is created by digging trenches in core laminate and pre-preg. In exemplary embodiments, pre-preg (pre-impregnated) refers to a layer of exemplary structures described herein, of insulation material inserted between the etched cores. In exemplary embodiments, the pre-preg can be a combination of mat, fabric, non-woven material or roving with resin, usually cured to the B-stage, ready for molding. A standard pre-preg contains more resin than is desired in the finished part; excess resin is bled off during cure. A net resin pre-preg contains the same resin content that is desired in the finished part; no resin bleed. Pre-preg containing a chemical thickening agent is called a mold-mat and those in sheet form are called sheet molding compounds.
[0021] In exemplary embodiments, the systems and methods described herein reduce cross-talk noise coupling from adjacent nets on PCBs. In exemplary embodiments, the systems and methods described herein decrease spacing between adjacent traces without any increase in noise coupling.
[0022] Capacitive coupling occurs due to presence of a dielectric medium as discussed above. The higher the value of the dielectric constant, Dk, of the dielectric medium, the stronger the capacitive coupling. In exemplary embodiment, trenches are cut and scoured out on each side of the signal traces with a laser (or any other etching mechanism, such as chemical, etc.). A pedestal of high dielectric constant material supports the trace. The thickness of core and pre-preg determine the distance of the trace from the conducting layer on other side of core. By the proximity rule, the return path is on the conducting layer(s) closest to the signal trace.
[0023] In exemplary embodiments, air is trenched in the dielectric between the adjacent side by side signal traces. Since the relative dielectric of the material between the signal and the reference layers is much greater than air, the result is a structure where the capacitance from signal trace to return path is much greater than the capacitance for signal trace to signal trace. Since the cross talk is define by coupling ratio of coupled capacitance to total capacitance, the trace can be closer in proximity with little coupling and the current will return through the reference planes and does not couple with adjacent traces.
[0024] Exemplary embodiments described herein include systems and methods for both single-ended and differential nets as now described.
[0025] Turning now to the drawings in greater detail, FIG. 2 illustrates a PCB apparatus 200 that reduces cross-talk for single-ended nets. In exemplary embodiments, the apparatus 200 includes a core layer 205 , a pre-preg layer 210 and a core insulating layer 220 having a return current reference layer 215 and a number of single layer nets 225 . In exemplary embodiments, the core layer 205 and the core insulator layer 220 are an insulating material. In exemplary embodiments, the core layer 205 includes copper sheets 206 bonded on each surface of the core layer 205 , in which the lower layer is a return current reference layer. In exemplary embodiments, an upper copper sheet bonded on an upper surface on the core insulating layer 220 is etched to create the single layer nets 225 . A lower copper sheet bonded to the lower surface of the core insulating layer 220 is retained as the return current reference layer 215 . In exemplary embodiments, the apparatus 200 further includes trenches 230 that have been etched into both the core insulating layer 220 and the pre-preg layer 210 . In exemplary embodiments, the formation of the trenches 230 further defines distinct pedestals 235 , each pedestal 235 supporting a single layer net 225 . As described herein, the trenches 230 ′are cut and scoured out on each side of the single layer nets 225 (i.e., the signal traces), thereby creating air gaps between respective pedestals 235 .
[0026] FIG. 3 illustrates a PCB apparatus 300 that reduces cross-talk for differential nets in accordance with exemplary embodiments. In exemplary embodiments, the apparatus 300 includes a core layer 305 , a pre-preg layer 310 and a core insulating layer 320 having a return current reference layer 315 and a number of differential nets 325 . In exemplary embodiments, the core layer 305 mid the core insulator layer 320 are an insulating material. In exemplary embodiments, the core layer 305 includes copper sheets 306 bonded on each surface of the core layer 305 , in which the lower layer is a return current reference layer. In exemplary embodiments, an upper copper sheet bonded on an upper surface on the core insulating layer 320 is etched to create the differential nets 325 . A lower copper sheet bonded to the lower surface of the core insulating layer 320 is retained as the return current reference layer 315 . In exemplary embodiments, the apparatus 300 further includes trenches 330 that have been etched into both the core insulating layer 320 and the pre-preg layer 310 . In exemplary embodiments, the formation of the trenches 330 further defines distinct pedestals 335 , each pedestal 335 supporting a differential net 325 . As described herein, the trenches 330 are cut and scoured out on each side of the single layer nets 325 (i.e., the signal traces), thereby creating air gaps between respective pedestals 335 .
[0027] FIG. 4 illustrates a flowchart of a printed circuit board fabrication method 400 for reducing cross talk in accordance with exemplary embodiments. At block 405 , traces (i.e., the single layer nets 225 or the differential nets 325 ) are etched onto the core insulator layers 220 , 320 . At block 410 , the trenches 230 , 330 are cut on each side the high speed signal trace so that all insulating material in the proximity of the nets 225 , 325 is removed. The pedestals 235 , 335 are formed from the remaining insulating material under the nets 225 , 325 . At block 415 , sections of the pre-preg layers 210 , 310 are cut, removed, and aligned above the target high speed signal trace (e.g., the nets 225 , 325 ), which had trenches 230 , 330 on each and supported by a pedestal 235 , 335 . In exemplary embodiments, the cut out sections are larger in the pre-preg layers 210 , 310 than the core insulating layers 220 , 320 to prevent the pre-preg layers 210 , 310 from expanding into the trenches 230 , 330 that are in formation. At block 420 , the stack of core layers 205 , 305 , core insulating layers 220 , 320 and the pre-preg layers 210 , 310 are pressed and heated.
[0028] FIG. 5 illustrates a graph 500 of noise coupling simulation results. The graph 500 plots noise level versus frequency comparing a noise coupling plot 505 in conventional PCBs against a reduced noise coupling plot 510 of a PCB in accordance with exemplary embodiments.
[0029] The capabilities of the present invention can be implemented in software, firmware, hardware or some combination thereof.
[0030] As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately.
[0031] Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided.
[0032] The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
[0033] While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.
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Methods and systems for reducing noise coupling in high-speed digital systems. Exemplary embodiments include a method, including etching a plurality of high speed signal traces onto a core insulating layer, forming trenches on respective sides of the plurality of high speed signal traces, thereby removing insulating material adjacent to the plurality of high speed signal traces and forming pedestals having remaining insulating material, the plurality of high speed signal traces disposed on and coupled to the remaining insulating material, coupling pre-preg material on the high speed signal traces, removing the pre-preg material adjacent the trenches, thereby retaining the pre-preg material aligned with the high speed signal traces, and heating and pressing a core layer to the pre-preg layer, and heating and pressing the pre-preg layer to the core insulating layer.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of priority to International Patent Application No. PCT/EP2009/007185 filed 7 Oct. 2009, which further claims the benefit of German Patent Application No. 10 2008 051 678.3 filed 15 Oct. 2008, the contents of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] Disclosed embodiments relate to a pneumatic brake cylinder.
BACKGROUND
[0003] Brake cylinders of this type are used, inter alia, in rail vehicles. There, they are frequently used to actuate a brake caliper, with the aid of which brake linings are pressed onto a brake disk. Here, the piston stroke is to always be approximately equally great, independently of the wear of the brake linings. For this purpose, an adjusting device is usually provided which has a spindle which is guided in a piston tube and an adjusting nut. During the normal braking operation, the adjusting nut is blocked in such a way that only a linear movement in the direction of the longitudinal axis of the brake cylinder is permitted, but not a rotational movement. A rotation of the adjusting nut may only be permitted for the adjusting operation when a certain wear of the brake linings has taken place. In order to control the rotational movement of the adjusting nut, what is known as a control sleeve is used which is arranged within the piston tube such that it can be displaced on the spindle.
[0004] A toothing system which can engage into a corresponding toothing system of the adjusting nut is usually provided on that side of the control sleeve which faces the adjusting nut. Since the control sleeve has to absorb high loadings, it is produced nowadays from a heavy metal continuous casting. Although this material ensures a high strength which is sufficient for this use, it permits only a relatively rough formation of the toothing system. This factor greatly limits the accuracy during the adjustment of the brake cylinder.
SUMMARY
[0005] The disclosed embodiment configure a pneumatic brake cylinder in such a way that, in the case of wear of the brake linings, very exact adjustment of the brake cylinder can take place. The production costs for the brake cylinder are to be reduced despite the improved adjustment.
[0006] According to the disclosed embodiments, the use of a control sleeve which is configured as a composite part which has a metallic coupling ring and a sliding sleeve made from plastic, the production costs can be reduced in comparison with the previously customary continuous casting. The metallic coupling ring can be configured, for example, as an extruded steel part. This makes the inexpensive production of a very fine and precise toothing system possible. The use of plastic for the sliding sleeve has likewise proven to be very inexpensive. The plastic of the sliding sleeve has a pronounced damping action during the absorption of the torque which is exerted by the adjusting nut. As a result, the wear of the toothing system, despite the higher degree of fineness, is reduced in comparison with the control sleeve made from a continuous casting. The weight of the pneumatic brake cylinder could also be reduced by the use of the novel control sleeve.
BRIEF DESCRIPTION OF THE FIGURES
[0007] Further details and advantages of the disclosed embodiments result from the description of one exemplary embodiment which will be explained in detail using the drawing, in which:
[0008] FIG. 1 shows a section through a pneumatic brake cylinder according to the disclosed embodiments,
[0009] FIGS. 2 and 3 show detail illustrations of the brake cylinder which is shown in FIG. 1 ,
[0010] FIG. 4 shows a three-dimensional illustration of one preferred exemplary embodiment of a control sleeve with inserted sliding blocks,
[0011] FIG. 5 shows the control sleeve from FIG. 4 in a sectioned illustration,
[0012] FIG. 6 shows a section through the coupling ring of the control sleeve from FIGS. 4 and 5 ,
[0013] FIG. 7 shows the coupling ring in a three-dimensional illustration,
[0014] FIG. 8 shows a three-dimensional illustration of the preferred exemplary embodiment of the control sleeve without locking arms,
[0015] FIG. 9 shows the coupling ring of the control sleeve from FIG. 8 without a sliding sleeve,
[0016] FIG. 10 shows a second exemplary embodiment of a control sleeve in a three-dimensional illustration with integrally formed locking arms, and
[0017] FIG. 11 shows the coupling ring of the control sleeve from FIG. 10 without a sliding sleeve.
DETAILED DESCRIPTION
[0018] In accordance with disclosed embodiments, the coupling ring is particularly advantageously encapsulated using injection molding by the sliding sleeve or the sliding sleeve is injection molded into the coupling ring. In this way, a fixed connection is brought about between the sliding sleeve and the coupling ring, without it having been necessary to perform an additional mounting step.
[0019] The coupling ring is advantageously provided with apertures in the region which is connected to the sliding sleeve. During the injection molding of the control sleeve, this leads to the apertures being filled with plastic. The connection between the coupling ring and the sliding sleeve is strengthened as a result. In particular, greater torques can be transmitted from the coupling ring to the sliding sleeve as a result.
[0020] The coupling ring has a toothing system for the positively locking engagement into a toothing system of the adjusting nut. Since the toothing system of the coupling ring can be of very fine configuration, very precise adjustment of the brake cylinder is possible. As a result of the positively locking connection between the coupling ring and the adjusting nut, a great torque can be transmitted despite the fine toothing system.
[0021] The toothing system is advantageously attached on the free end side of the coupling ring and is configured as an oblique internal toothing system. A great engagement surface area is thus ensured in conjunction with an oblique external toothing system on an end side of the adjusting nut. The oblique position of the two toothing systems also at the same time brings about a centering action, with the result that the toothing system of the control sleeve and the toothing system of the adjusting nut are in each case in engagement with one another over their full surface area.
[0022] According to disclosed embodiments, a locking device is provided which prevents rotation of the control sleeve. In this way, the torque which is transmitted by the adjusting nut can be absorbed reliably. The locking device is configured in such a way that only the rotation of the control sleeve is prevented. In contrast, a displacement of the control sleeve in the direction of the longitudinal axis of the brake cylinder is permitted in a predefined range.
[0023] A piston tube is advantageously provided which is actuated by the piston. Said piston tube has slot-shaped openings, through which the locking arms extend. The slot-shaped openings are dimensioned in such a way that the movement of the control sleeve can be decoupled from the movement of the piston tube.
[0024] The locking arms engage with their free end into slot-shaped cutouts. The width of the slot-shaped cutouts is adapted to the width of the locking arms. In this way, rotation of the control sleeve is prevented reliably.
[0025] The longitudinal extent of the slot-shaped cutouts is dimensioned in such a way that the cutouts act as a stop for the control sleeve and restrict a sliding movement of the control sleeve. Here, the permitted sliding section of the control sleeve corresponds to the spacing of the brake linings from the brake disk plus the elastic deformation of the parts which transmit the braking force between the brake cylinder and the brake linings.
[0026] In one exemplary embodiment, the slot-shaped cutouts are provided in the housing of the brake cylinder or a part which is connected to the latter. The locking arms are connected fixedly to the sliding sleeve and are advantageously injection molded onto the latter. In this exemplary embodiment, the locking arms move together with the sliding sleeve.
[0027] In another exemplary embodiment, the slot-shaped cutouts are provided in the sliding sleeve itself. In contrast, the locking arms are configured as sliding blocks and are connected fixedly to the housing of the brake cylinder, in particular are screwed to it. In this particularly advantageous exemplary embodiment, the sliding blocks do not have to be moved. As a result, the weight of the control sleeve can be reduced further. The lower weight of the control sleeve makes itself felt by reduced inertia during its movement. As a result, even higher precision is possible in the adjustment of the brake cylinder.
[0028] It should be noted, that the disclosed embodiments may have been described above and below with respect to different subject-matter. In particular, some embodiments may be described with reference to apparatus components, whereas those or other embodiments have been described with reference to methodologies. However, a person skilled in the art will gather from the above and the following description that, unless notified otherwise, in addition to any combination features belonging to one type of subject-matter also any combination between features relating to different subject-matter, in particular between features of apparatuses and features of methodologies, is considered to be disclosed with this application.
[0029] The design of the novel control sleeve can be gathered from FIGS. 4-11 , one preferred exemplary embodiment being shown in FIGS. 4-9 . The control sleeve 1 is constructed as a composite part, a coupling ring 4 having been connected to a sliding sleeve 2 . The coupling ring 4 is configured as an extruded steel part and comprises a toothed ring 9 and a connecting ring 10 . The connecting ring 10 and the toothed ring 9 have the same internal diameter, whereas the external diameter of the toothed ring 9 is dimensioned to be greater than the external diameter of the connecting ring 10 . As a result, the step 12 is produced in the outer contour of the coupling ring 4 . The free end side of the toothed ring 9 is provided with an oblique internal toothing system 5 . The connecting ring 10 has a number of round apertures 11 .
[0030] Two sliding channels 3 which lie opposite one another are machined into the sliding sleeve 2 . The sliding blocks 6 engage into the sliding channels 3 . The width of the sliding blocks 6 is adapted exactly to the width of the sliding channels 3 , with the result that no rotational movement of the sliding sleeve 2 is possible if the sliding blocks 6 are fixed. In order for it to be possible to fix the sliding blocks 6 , the fastening holes 7 are provided which serve, in particular, to receive screws. The longitudinal extent of the sliding channels 3 is dimensioned in such a way that the feed gap 8 remains during engagement of the sliding blocks 6 . The significance of the feed gap 8 will be explained in greater detail further below during the functional description of the brake cylinder.
[0031] During the production of the control sleeve 1 , the coupling ring is inserted into the injection molding die. During the injection molding of the control sleeve 1 , the plastic also fills the step 12 of the coupling ring 4 and enters the apertures 11 of the connecting ring 10 . As a result, an excellent connection is ensured between the coupling ring 4 and the sliding sleeve 2 . The plastic in the apertures 11 prevents the components from being able to rotate with respect to one another.
[0032] FIGS. 10 and 11 show a further exemplary embodiment of a control sleeve. The coupling ring 15 which is used here has a stepless outer circumference. The step for receiving the sliding sleeve 14 is situated here on the inner side of the coupling ring 15 . While the coupling ring 4 is plugged in the sliding sleeve 2 in the first exemplary embodiment according to FIGS. 4-9 , the sliding sleeve 14 is plugged in the coupling ring 15 in this exemplary embodiment. Here too, apertures are provided which, filled with the plastic of the sliding sleeve 14 , bring about an antirotation safeguard between the sliding sleeve 14 and the coupling ring 15 .
[0033] In the exemplary embodiment according to FIGS. 10 and 11 , locking arms 16 are injection molded directly onto the sliding sleeve 14 . The locking arms 16 have runners 17 , by way of which the locking arms engage into a stop ring which is screwed to the brake cylinder. Here too, recesses are provided in accordance with the sliding channels 3 of the first exemplary embodiment, with the result that a certain longitudinal displacement of the runners 17 is possible. The extent of the displacement corresponds to the feed gap 8 in the first exemplary embodiment.
[0034] The use of the novel control sleeve will be explained using the pneumatic brake cylinder which is shown in FIG. 1 . The fastenings 21 for a brake caliper are situated firstly on the yoke 20 and secondly on the housing 19 . In order to actuate the brake, the brake caliper (not shown here) has to be pressed apart. This means that the spacing between the yoke 20 and the housing 19 has to be enlarged.
[0035] The piston 22 is provided in the housing 19 . The pressure space 30 is situated between the piston 22 and the housing 19 . The compressed air connection, via which compressed air is fed to the pressure space 30 , cannot be seen in this illustration. The piston tube 23 is actuated by the piston 22 . However, the piston 22 is not connected fixedly to the piston tube 23 , but rather is inserted loosely into the brake cylinder. The actuation of the piston tube 23 takes place merely via an annular bearing face, with which the piston 22 presses onto the piston tube 23 .
[0036] Slots are provided in the piston tube 23 , through which slots sliding blocks 6 extend which are screwed to the housing 19 . This measure prevents rotation of the piston tube 23 with respect to the housing 19 , but in contrast permits a longitudinal displacement of the piston tube 23 . In the case of the longitudinal displacement, the piston tube 23 is supported by the annular sliding bands 31 on the inner wall of the housing 19 . The piston 22 and the piston tube 23 are held in their rest position by the piston return spring 26 which is supported on the housing 19 and the piston tube 23 .
[0037] The spindle 24 is situated in the piston tube 23 . The position of the spindle 24 is controlled by the adjusting nut 25 . The adjusting nut 25 and spindle 24 are connected to one another via a thread which is not self-locking, with the result that a force in the direction of the longitudinal axis of the spindle 24 exerts a torque on the adjusting nut 25 . This force is exerted on the spindle 24 by the conical spring 28 which is supported on the yoke 20 and the piston tube 23 . The conical spring 28 therefore exerts a force which attempts to pull the spindle 24 out of the cone tube 23 .
[0038] On its oblique end side, the adjusting nut 25 has an external toothing system 34 (see, in particular, FIGS. 2 and 3 which illustrate the part denoted by A in FIG. 1 on an enlarged scale and in different working states). The internal toothing system 5 of the control sleeve 1 is normally in engagement with the external toothing system 34 of the adjusting nut 25 . The control sleeve 1 is prevented from rotating via the sliding blocks 6 which are screwed to the housing 19 . As a result of the engagement of the internal toothing system 5 of the control sleeve 1 with the external toothing system 34 of the adjusting nut 25 , the latter is likewise prevented from rotating. The control sleeve 1 is prestressed via the locking spring 27 which is supported on the control sleeve 1 and on the piston tube 23 . A toothed ring which is connected to the spindle 24 is pressed into a toothing system of the yoke 20 with the aid of the disk spring 29 , with the result that rotation of the spindle 24 with respect to the yoke 20 is prevented.
[0039] In the following text, the function of the brake cylinder 18 is to be described:
[0040] The piston 22 is pressed to the left by an increase of the pneumatic pressure in the pressure space 30 . Here, it actuates the piston tube 23 and likewise presses it to the left, counter to the force of the piston return spring 26 . The control sleeve 1 which is prestressed by the locking spring 27 is pressed with its internal toothing system 5 onto the external toothing system 34 of the adjusting nut 25 and likewise moves to the left together with the piston tube 23 , spindle 24 , adjusting nut 25 and yoke 20 . In contrast, the piston tube toothing system 33 is not in engagement with the external toothing system of the adjusting nut 25 . This state is shown in FIG. 2 .
[0041] At the moment, at which the control sleeve 1 has been displaced so far to the left that the feed gap 8 between the sliding blocks 6 and the boundary of the sliding channels 3 is closed, the brake linings (not shown here) come into contact with the brake disk. From this point in time, a counterpressure is built up via the yoke 20 . Since the feed gap 8 has now been closed, the control sleeve 1 can no longer participate in a further movement of the piston tube 23 .
[0042] The piston tube 23 is then displaced further to the left by a small amount, counter to the force of the conical spring 28 , while the yoke 20 , spindle 24 and adjusting nut 25 remain at the same location. As a result of this displacement of the piston tube 23 with respect to the adjusting nut 25 , the external toothing system 34 of the adjusting nut 25 comes out of engagement with the internal toothing system 5 of the control sleeve 1 . At the same time, however, the external toothing system 34 comes into engagement with the piston tube toothing system 33 .
[0043] In the case of a further build up of pressure in the pressure space 30 , the brake linings are pressed against the brake disk, the piston tube 23 being pressed with great force against the adjusting nut 25 . As a result of these forces which are directed counter to one another of the piston 22 and piston tube 23 on one side and of the yoke 20 , spindle 24 and adjusting nut 25 on the other side, a torque is exerted on the adjusting nut 25 . This torque is absorbed by the piston tube toothing system 33 and transmitted to the piston tube 23 . The torque passes to the housing 19 via the sliding blocks 6 . The housing 19 is connected to the brake caliper via the fastenings 21 in such a way that the torque is finally absorbed here. This state of the piston tube 23 , adjusting nut 25 and control sleeve 1 is shown in FIG. 3 .
[0044] When the brake is released, the piston tube toothing system 33 is also released again from the external toothing system 34 of the adjusting nut 25 . At the same time, the external toothing system 34 of the adjusting nut 25 comes into engagement again with the internal toothing system 5 of the control sleeve 1 .
[0045] Whereas no rotation of the adjusting nut 25 is permitted during a normal braking operation, the adjusting nut 25 has to be able to rotate when an adjustment becomes necessary on account of wear of the brake linings. If a certain amount of wear of the brake linings has taken place, the gap between the brake linings and the brake disk has also increased. As a result, a greater piston stroke is necessary, in order to bring the brake linings into contact with the brake disk.
[0046] The braking process is initiated as in the case of a normal braking operation. The piston 22 , piston tube 23 and control sleeve 1 move together to the left. The control sleeve 1 participates in this movement until the feed gap 8 is closed. The internal toothing system 5 of the control sleeve 1 is then decoupled from the external toothing system 34 of the adjusting nut 25 . In contrast with a normal braking process, however, no counterpressure is then built up, since the brake linings are not yet in contact with the brake disk. As a result, the piston tube toothing system 33 does not yet couple into the external toothing system 34 of the adjusting nut 25 . A force is exerted via the conical spring 28 on the yoke 20 and spindle 24 , which force attempts to pull the spindle 24 to the left out of the piston tube 23 . Here, a torque acts on the adjusting nut 25 . Since, in this state, the external toothing system 34 of the adjusting nut 25 is coupled neither to the internal toothing system 5 of the control sleeve 1 nor to the piston tube toothing system 33 , the adjusting nut 25 can yield to the torque and rotates on the spindle 24 . As a result of this rotation of the adjusting nut 25 , the spindle 24 can be pulled out to the left relative to the adjusting nut 25 .
[0047] The rotation of the adjusting nut 25 continues until the brake linings have come into contact with the brake disk. At this moment, a counterpressure is built up again which brings about coupling of the piston tube toothing system 33 to the external toothing system 34 of the adjusting nut 25 . The adjusting operation is therefore finished and further braking processes take place again without adjustment until a certain amount of wear of the brake linings has occurred once again.
[0048] If an adjustment is no longer possible, the brake linings have to be changed. Here, the brake cylinder 18 also has to be reset into its original state again. To this end, force is applied to the return hexagon 32 and the spindle 24 is turned completely into the piston tube 23 again. During the first braking process, after the mounting of the new brake linings, an adjustment takes place again, with the result that here too the predefined spacing between the brake linings and the brake disk is automatically set correctly.
LIST OF DESIGNATIONS
[0000]
1 Control sleeve
2 Sliding sleeve
3 Sliding channel
4 Coupling ring
5 Internal toothing system
6 Sliding block
7 Fastening hole
8 Feed gap
9 Toothed ring
10 Connecting ring
11 Aperture
12 Step
13 Further exemplary embodiment of a control sleeve
14 Sliding sleeve
15 Coupling ring
16 Locking arm
17 Runner
18 Brake cylinder
19 Housing
20 Yoke
21 Fastening for brake caliper
22 Piston
23 Piston tube
24 Spindle
25 Adjusting nut
26 Piston return spring
27 Locking spring
28 Conical spring
29 Disk spring
30 Pressure space
31 Sliding band
32 Return hexagon
33 Piston tube toothing system
34 External toothing system of the adjusting nut
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The invention relates to a pneumatic brake cylinder including a piston for transferring the pneumatic pressure to a brake, and a device for automatic adjustment in the event of wear of the brake linings, the device comprising a spindle, an adjusting nut, and a control sleeve that can be engaged with the adjusting nut. According to the invention, the control sleeve is embodied as a composite part including a metallic coupling ring and a sliding sleeve of a plastic material.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of copending U.S. provisional patent application Ser. No. 61/638,939, filed Apr. 26, 2012, and co-pending U.S. provisional patent application Ser. No. 61/651,910, filed May 25, 2012, each of which applications is incorporated herein by reference in its entirely.
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH OR DEVELOPMENT
[0002] The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) in which the Contractor has elected to retain title.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not Applicable
FIELD OF THE INVENTION
[0005] The invention relates to semiconductor fabrication methods in general and particularly to methods useful in making submillimeter-wave and terahertz devices.
BACKGROUND OF THE INVENTION
[0006] Submillimeter-wave heterodyne receivers are important for a number of applications, from providing quantitative molecular abundance profiles in atmospheres to detecting contra-band. The current generation of receivers relics on metal waveguide blocks made using conventional precision machining tools such as end mills. For real time imaging capabilities and for large fields of view it is highly desirable to have two dimensional detector arrays, and therefore novel approaches to building compact waveguide architectures are needed.
[0007] CNC metal machining is a highly refined method capable of producing terahertz circuits, but the cost is high due to the serial nature of the process.
[0008] Micromachining of submillimeter-wave and terahertz circuits is a very attractive approach for terahertz waveguide components since it offers the potential for lower cost and better precision fabrication. See, for example, V. Lubecke, K. Mizuno, and G. Rebeiz, “Micromachining for terahertz applications,” Microwave Theory and Techniques, IEEE Transactions on , vol. 46, no. 11, pp. 1821-1831, November 1998, Micromachining offers the potential for batch fabrication at photolithographic accuracies, thus reducing the cost per component-while improving precision and uniformity. This type of fabrication technology could enable the development of multi-pixel terahertz systems and novel components that are not compatible with CNC metal machining.
[0009] Several different micromachining techniques exist for fabrication of terahertz circuits. Thick, permanent resist such as SU-8 is used to build waveguide structures and has attracted attention due to the minimal equipment requirements and the high aspect ratio features it can produce. See, for example, X. Shang, M. Re, Y. Wang, and M. Lancaster, “Micromachined W-band waveguide and fiber with two embedded H-plane bends,” Microwaves, Antennas Propagation, IET , vol. 5, no. 3, pp. 334-339, 21 2011; and C. H. Smith, H. Xu. and N. Barker, “Development of a multi-layer SU-8 process for terahertz frequency waveguide blocks.” Microwave Symposium Digest, 2005 IEEE MTT - S International , pp. 439-442, June 2005.
[0010] LIGA is a German acronym for Lithographic, Galvanoformung, Abformung (Lithography, Electroplating, and Molding) that describes a fabrication technology used to create high-aspect-ratio microstroctures. See W. Bacher et al., The LIGA technique and its potential for microsystems-a survey, IEEE Trans. Industrial Electronics, 42, 431-441, October 1995. The LIGA technique offers the possibility to manufacture microstructures with arbitrary lateral geometry, lateral dimensions down to below 1 μm and aspect ratios up to 500 from a variety of materials (metals, plastics, and ceramics). LIGA focuses on thick resists similar to SU-8 as molds for electroplating, and thus can be used to build-up metal waveguides. See, for example, J. Stance and N. Barker. “Fabrication and integration of micromachined submillimeter-wave circuits,” Microwave and Wireless Components tellers, IEEE , vol. 21, no. 8, pp. 409-411, August 2011; C. Nordquist, M. Wanke, A. Rowen, C. Arrington, M. Lee, and A. Grine, “Design, fabrication, and characterization of metal micromachined rectangular waveguides at 3 THz,” in Antennas and Propagation Society International Symposium, 2008, AP - S 2008. IEEE , July 2008, pp. 1-4; and E. Cullens, L. Ranzani, K. Vanhille, E. Grossman, N. Ehsan, and Z. Popovic. “Micro-fabricated 130-180 GHz frequency scanning waveguide arrays,” Antennas and Propagation, IEEE Transactions on , vol. 60, no. 8, pp. 3647-3653, August 2012.
[0011] These resist based technique have some disadvantages. SU-8 processes are very challenging to stabilize and the resist is difficult to deposit uniformly, reducing the precision of each layer thickness or requiring an additional processing step such as lapping. LIGA suffers from similar problems, as electroplating a flat layer of tens to hundreds of microns thick is very difficult, so lapping is also usually required to planarize each layer.
[0012] Recent studies have been successful in the fabrication of silicon micromachined components but there is still alack of effective methods to characterize those circuits. In particular, coupling between the micromachined waveguide and standard metal waveguide flanges suffers from misalignment problems due to the difficulty of aligning to non-metal machined waveguide components.
[0013] There is a need for improved methods for fabricating and using submillimeter wave and terahertz devices.
SUMMARY OF THE INVENTION
[0014] According to one aspect, the invention features an alignment pin having a first end and a second end. The alignment pin comprises a compressible structure having a central axis, the compressible structure having a arcuate surface having a surface roughness of less than tens of microns disposed about the central axis, the compressible structure having an aperture oriented along the central axis defined within the compressible structure, the compressible structure having two opposed projections each oriented in a direction perpendicular to the central axis, the compressible structure configured to assume a relaxed configuration in which the two opposed projections are spaced apart when no mechanical force is applied to the two opposed projections and the compressible structure is configured to assume a compressed configuration upon the application of a mechanical force to the two opposed projections.
[0015] In one embodiment, the compressible structure is made of silicon
[0016] In another embodiment, the compressible structure has a length of tens of microns or more measured parallel to the central axis.
[0017] In yet another embodiment, the two opposed projections are spaced apart by a distance measured in tens of microns when the mechanical force is not applied to the two opposed projections.
[0018] In still another embodiment, the first end and the second end each have a dimension d measured along a line perpendicular to and intersecting the central axis, the line having each of its two ends situated on the arcuate surface when the mechanical force is not applied to the two opposed projections and wherein the first end and the second end each have a dimension c smaller than the dimension d measured along a line perpendicular to and intersecting the central axis and having each of its two ends situated on the arcuate surface upon the application of mechanical force to the two opposed projections.
[0019] According to another aspect, the invention relates to a method of aligning two, component layers of a multilayer device. The method comprises the steps of providing an alignment pin having a first end and a second end, the alignment pin comprising a compressible structure having a central axis, the compressible structure having a arcuate surface having a surface roughness of less than tens of microns disposed about the central axis, the compressible structure having an aperture oriented along the central axis defined within the compressible structure, the compressible structure having two opposed projections each oriented in a direction perpendicular to the central axis, the compressible structure configured to assume a relaxed configuration when no mechanical force is applied to the two opposed projections wherein the first end and second end each have a dimension d measured along a line perpendicular to and intersecting the central axis, the line having each of its two ends situated on the arcuate surface, and the compressible structure configured to assume a compressed configuration upon the application of a mechanical force to the two opposed projections wherein the first end and second end each have a dimension c smaller than the dimension d measured along the line perpendicular to and intersecting the central axis, the line having each of its two ends, situated on the arcuate surface; providing a first layer of a multilayer device, the first layer having a first layer aperture defined in a surface of the first layer, the first layer aperture having a dimension larger than the dimension c and smaller titan the dimension d; providing a second layer of the multilayer device, the second layer having a second layer aperture defined in a surface of the second layer, the second layer aperture having a dimension substantially equal to the first layer aperture, the second layer aperture designed to be in registry with the first layer aperture when the first layer and the second layer are aligned; applying mechanical force to the two opposed projections of the compressible structure to provide the compressible structure in the compressed configuration; inserting the first end of the alignment pin in the compressed configuration into the first layer aperture defined in the surface of the first layer; releasing the mechanical force from the two opposed projections of the compressible structure, thereby mating the first end of the alignment pin with the first layer of the multilayer device; and mating the second layer aperture of the second layer of the multilayer device with the second end of the alignment pin, thereby bringing the first layer and the second layer of the multilayer device into alignment.
[0020] In one embodiment, the alignment of the first layer of the multilayer device and the second layer of the multilayer device is an alignment to within 5 μm
[0021] In another embodiment, at least one of one of the first layer of the multilayer device and the second layer of the multilayer device is fabricated from a semiconductor wafer.
[0022] In yet another embodiment, at least one of one of the first layer of the multilayer device and the second layer of the multilayer device is fabricated from a metal.
[0023] In still another embodiment, the method further comprises the step of securing the first layer of the multilayer device and the second layer of the multilayer device in an assembled state.
[0024] The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The objects and features of the invention can be better understood with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawing, like numerals are used to indicate like parts throughout the various views.
[0026] FIG. 1A is an image of a silicon micromachined waveguide.
[0027] FIG. 1B depicts the results of an AFM measurement on a portion of the surface of the silicon micromachined waveguide shown in FIG. 1A and indicates that 18 nm rms surface roughness can be achieved.
[0028] FIG. 2A is an image of an etched waveguide structure produced using fixed plasma power.
[0029] FIG. 2B is an image of an etched waveguide structure produced using power increase (ramping up) during etching, which results in better surface quality of the waveguide structures as compared to the results shown in FIG. 2A .
[0030] FIG. 3 is an SEM image of an etch pattern with the Bosch effect on the sidewall, where scalloping is visible.
[0031] FIG. 4 is an SEM image showing the improvement of the sidewall smoothness and angle by modifying the etching and passivation step duty cycles.
[0032] FIG. 5A is an SEM image of DRIE etched patterns with 5° sidewall vertical angle.
[0033] FIG. 5B is an SEM image of DRIE etched patterns with 8° sidewall vertical angle.
[0034] FIG. 6 illustrates a silicon donut 610 and etched pockets 620 which together are used to achieve precise wafer-to-wafer alignment in one embodiment.
[0035] FIG. 7 is an exploded view of a stack of silicon wafers comprising a submillimeter-wave receiver front-end.
[0036] FIG. 8 is an SEM image of a Si-based W-band amplifier, showing a double-step each 280 μm-11.5 μm.
[0037] FIG. 9 is an SEM image of Si-based etched cavities and waveguides fabricated for the 560 GHz Radiometer-On-A -Chip architecture.
[0038] FIG. 10 is a graph showing the measured performance as a function of frequency of the 1st and 2nd ROC stages featuring a W-band metal pre-amplifier and silicon-based power amplifier MMICs measured separately and cascaded.
[0039] FIG. 11 is a graph showing the measured performance of the 3rd and 4th ROC stages showing the DSB mixer conversion losses and noise temperature vs. central RF range.
[0040] FIG. 12 is an SEM image of improved Si-etched cavities and waveguides for the 560 GHz Radiometer-On-A-Chip architecture.
[0041] FIG. 13 illustrates assembled layers 1305 , 1307 with circular cavities 1310 , 1320 and donuts 1330 .
[0042] FIG. 14 illustrates cavities 1410 , 1420 having a range of diameters.
[0043] FIG. 15A is a perspective view of the bottom half of the silicon micromachined 3 dB waveguide hybrid coupler.
[0044] FIG. 15B is an exploded view of the complete test package.
[0045] FIG. 16A is a diagram of the silicon compression pin showing the relevant dimensions of one embodiment.
[0046] FIG. 16B is an image of the compression pin during assembly as it is squeezed by the tweezers to insert it into the alignment pocket or cavity.
[0047] FIG. 16C is an image of the compression pin after it has been released into the alignment pocket or cavity.
[0048] FIG. 17A is an image of a model showing the vernier on two mating wafers.
[0049] FIG. 17B is a photomicrograph taken during an alignment measurement showing 1 μm misalignment.
[0050] FIG. 18A is a perspective drawing of an assembled test apparatus showing the mating of the metal waveguide fixture to the silicon waveguide.
[0051] FIG. 18B is a closeup of the test apparatus showing the E-plane cross-section and illustrating the alignment of the silicon bosses to the metal alignment pockets.
[0052] FIG. 18C is a closeup of the test apparatus showing the H-plane cross section and illustrating the etch angle of the backside silicon etch.
[0053] FIG. 19A is a graph showing a measurement of s 11 vs frequency for the E-plane of the waveguide.
[0054] FIG. 198 is a graph showing a measurement of s 11 vs frequency for the H-plane of the waveguide.
[0055] FIG. 19C is a graph showing the measured waveguide loss per millimeter of the E and H-plane split silicon waveguides.
[0056] FIG. 20 is a graph showing a comparison of the repeatability of the silicon boss alignment to that of the UG-386 precision flange.
[0057] FIG. 21 is an image of the waveguide hybrid measurement apparatus,
[0058] FIG. 22A is a graph of the measured S-parameters as a function of frequency for a 3 dB hybrid coupler.
[0059] FIG. 22B is a graph of the phase balance a function of frequency between the direct and coupled ports.
DETAILED DESCRIPTION
[0060] Advanced semiconductor nanofabrication techniques are utilized to design, fabricate and demonstrate a super-compact, low-mass (<10 grams) submillimeter-wave heterodyne front-end. RF elements such as waveguides and channels are fabricated in a silicon wafer substrate using deep reactive ion etching (DRIE). Etched patterns with sidewalls angles controlled with 1° precision are reported, while maintaining a surface roughness of better than 20 nm rms for the etched structures. This approach is also used to build compact 2-D imaging arrays in the THz frequency range.
[0061] In another example, the techniques are used to assemble and measure micromachined submillimeter-wave waveguide circuits operating from 500 to 750 GHz. A novel micromechanical compression pin (or alignment pin) has been developed to improve wafer-to-wafer alignment to less than 1 μm. Connection between the silicon waveguide and a VNA is aligned through a silicon boss that inserts into the custom-waveguide flange. Waveguide loss Ls characterized for both E and H-plane split waveguides and is found to be similar to standard metal waveguides. Measurement of a 3 dB hybrid coupler operating from 500 to 600 GHz is also described.
EXAMPLE 1
A Compact 530-590 GHz Receiver Front-End in an All-Silicon Waveguide Structure
[0062] We demonstrate the use of advanced semiconductor nanofabrication technologies to build a compact 530-590 GHz receiver front-end in an all-silicon waveguide structure. The receiver block comprises a stack of precisely etched silicon wafers aligned to one another using silicon pins. The wafers are processed using deep reactive ion etching (DRIE) techniques to form channels for mounting low parasitic GaAs Schottky diode chips and custom waveguide matching circuits for coupling THz power both laterally and vertically with low return loss. We also describe the ability to etch silicon waveguides with precisely controlled vertical angles, which may enable the integration of high-performance all-silicon conical beam horns for coupling energy to and from free space.
Micromachining of Silicon
[0063] The utilization of micromachined silicon for THz circuits places a number of important constraints on the structures. First, THz frequency waveguides and device channels need very smooth sidewalls and bottom surfaces in order to minimize ohmic losses. The cross sections of the waveguide walls also have to be precisely rectangular in order to minimize scattering from geometric inhomogeneities and integrate MMIC amplifiers, multipliers, and mixers successfully. Finally, a robust and accurate alignment scheme is needed to assure good impedance matching across vertical wafer-to-wafer waveguide transitions.
[0064] Silicon wafers are processed with conventional UV lithography, and Deep Reactive Ion Etching (DRIE) techniques using thick AZ9260 resist as etching mask. The DRIE technique used is the well-known Bosch process based on the alternative exposures to SF 6 and C 4 F 8 gases. With optimized plasma power and etching gas ratios, we can achieve a selectivity of 50:1 for etching at low rates (2 μm/min) and up to 75:1 for long and deep etches (4 μm/min). The second recipe is mainly used for etch-through waveguide openings where 1 mm of silicon is etched with a 15 μm resist mask and where sidewalls and bottom surfaces roughnesses are less critical.
Etched Pattern Surface Roughness
[0065] To avoid losses during signal transmission, it is advantageous that the DRIE waveguide structures have a surface roughness of less than 50 nm. With these smooth surfaces, the excess attenuation coming from the surface roughness is expected to be negligible compared to the total ohmic losses. As shown in FIG. 1 , our optimized DRIE process can achieve an 18 nm rms surface roughness on the bottom of a 280×280×40 μm waveguide channel etched in a 500 μm thick silicon wafer.
[0066] During the DRIE Bosch process, the SF 6 is used to etch the silicon, while the C 4 F 8 passivities the etched surfaces. This alternation of etching and passivation steps results in anisotropic etch of the silicon and it can introduce unwanted modulation in the sidewall profile. With the control of the gas flows and pressures, this scalloping effect can be significantly reduced. To achieve the small levels of surface roughness shown in FIG. 1A and FIG. 1B , a specific etching recipe was developed with a ramp up of the plasma power during the etch cycle, instead of keeping it constant. FIG. 1A is an image of a silicon micromachined waveguide. FIG. 1B depicts the results of an AFM measurement on a portion of the surface of the silicon micromachined waveguide shown in FIG. 1A and indicates that 18 nm rms surface roughness can be achieved.
[0067] FIG. 2A and FIG. 2B compare two similar waveguides, both 500 μm×300 μm and 100 μm deep. FIG. 2A is an image of an etched waveguide structure produced using fixed plasma power. FIG. 2B is an image of an etched waveguide structure-produced using power increase (ramping up) during etching, which results in better surface quality of the waveguide structures as compared to the results shown in FIG.
Sidewall Smoothness and Vertically
[0068] In addition to having small surface roughness, the etched sidewalls must be perpendicular to the top surface with a maximum error of 1°. This is to ensure two important criteria: first, pattern size variations will affect the characteristic impedance, and second, accurate alignment between wafers depends on the high tolerances of the dowel pin/hole mating structures we use. FIG. 3 and FIG. 4 show how changing the ratio of “etching” versus “passivation” can improve the sidewall quality. FIG. 3 is an SEM image of an etch pattern with the Bosch effect on the sidewall, where scalloping is visible. FIG. 4 is an SEM image showing the improvement of the sidewall smoothness and angle by modifying the etching and passivation step duty cycles.
[0069] While vertical sidewall profiles are important for waveguides, some RF structures such as horns need sidewalls with controlled slopes. For example, submillimeter-wave Pickett-Potter feed horns are widely used for submillimeter wave components. The typical Pickett horn has a slope of 13.5° but this angle can be reduced to 5°, if the total height of the horn is redesigned to control the sidelobes of the propagation modes. FIG. 5A and FIG. 5 B show two SEM images of DRIE patterns with intentionally angled sidewalls of 5° and 8° from normal. Theses angles can be obtained by addition of power ramps and various cycle times of etching and passivation steps.
Precise Wafer-to-Wafer Alignment
[0070] A technique using circular etched pockets and silicon donut-shaped dowel pins has also been developed to align two wafers together. The donut shape was selected to prevent trapped air under the silicon pin during the assembly and to make it easier to handle with tweezers. FIG. 6 illustrates a silicon donut 610 and etched pockets 620 which together are used to achieve precise wafer-to-wafer alignment in one embodiment. With this technique, we can achieve a 5 μm alignment or better. In other embodiments, the silicon pins described hereinafter can be used to effect the alignment between the various layers.
560 GHZ Radiometer-On-A-Chip
[0071] Utilizing the silicon nanofabrication techniques discussed above, a super-compact 560 GHz receiver front-end has been designed, fabricated and tested. FIG. 7 is an exploded view of a stack of silicon wafers comprising a submillimeter-wave receiver front-end. As shown in FIG. 7 , the structure includes a plurality of layers including heat sink 1 , power amplifier (PA) 2 , interface layer 3 , submillimeter receiver 4 , spacer layer 5 , and antenna 6 , Each layer is individually fabricated and the stack is then assembled by fitting and aligning each respective layer to its neighbor or neighbors. The LO signal from the input waveguide is amplified, multiplied and mixed with the RF signal from the antenna.
[0072] The first and second stages of this receiver-on-a-chip (ROC) feature a W-band power amplifier (PA) MMIC packaged in a silicon micro-machined block. The transitions are chosen to have the input/output waveguide interfaces with external waveguides on the flat surface of the wafers. FIG. 8 is an SEM image of a Si-based W-band amplifier, showing a double-step etch 280 μm-115 μm.
[0073] The third and fourth stages of the ROC feature an integrated 265-300 GHz tripler and 530-600 GHz subharmonic mixer using MMIC planar Schottky diode devices. These two stages require 4 silicon pieces and nine DRIE etches with depths ranging from 20 μm to 750 μm (etchthrough). FIG. 9 is an SEM image of Si-based etched cavities and waveguides fabricated for stages 3 and 4 of the 560 GHz Radiometer-On-A-Chip architecture. These silicon pieces were fabricated before those presented previously, and therefore the bottom of the etched patterns is very rough.
Measurement Apparatus and Results
[0074] The first and second stages of the ROC were tested first in order to measure the amount of output, power available at W-based to pump the following stages. FIG. 10 is a graph showing the measured performance as a function of frequency of the 1st and 2nd ROC stages featuring a W-band metal pro-amplifier and silicon-based power amplifier MMICs measured separately and cascaded. Using a conventional metal machining pro-amplifier cascaded with a silicon packaged MMIC power amplifier, an output power of 40-140 mW was measured between 92 and 104 GHz.
[0075] The third and fourth stages of the ROC have been tested using a fundamental LO source consisting of an Agilent ES257D synthesizer, an Agilent 83558A W-band source, a W-band pre-amplifier stage and a W-band rotary vane attenuator. As shown in FIG. 11 , preliminary results give a DSB mixer noise temperature of 4860 K and DSB mixer conversion losses of 12.1 dB at 540 GHz. FIG. 11 is a graph showing the measured performance of the 3rd and 4 th ROC stages showing the DSB mixer conversion losses and noise temperature vs. central RF range.
[0076] Simulated results with a 20 nm rms surface roughness suggest that the mixer performance should be better by about 3 dB. However, as mentioned before, the silicon pieces used for these measurements were very rough, so we can in part attribute these worse than expected results to that high surface roughness. Nonetheless, the receiver performance of FIG. 11 provides proof of concept that nanofabrication technologies can be utilized to make compact and low-mass submillimeter wave receiver front ends.
[0077] Other silicon waveguide structures have been fabricated using the DRIB recipes reported hereinabove. In the SEM image shown in FIG. 12 , etched cavities and waveguides have the 18 nm rms smooth surface similar to that illustrated in FIG. 1B . This technique provides the flexibility of building a radiometer-on-a-chip and is expected to be useful in fabricating large format array receivers, multi-frequency imaging arrays, and beam-steering capabilities for heterodyne array receivers.
EXAMPLE 2
Silicon Micromachined Waveguide Components
[0078] The process adopted in this example is silicon DRIE. Many of the problems above such as control of the etch angle and etch depth have be overcome by extensive process development. In addition, by having the bulk of the packaging in a high-resistivity material, DC biasing circuitry and thru-wafer vias can be directly integrated to circuit density and reduce assembly time.
[0079] A new flange alignment scheme enabling repeatable connection to metal waveguide components is described and test results are presented.
[0080] We also describe a novel technique for a precise and controllable alignment between each silicon wafer. As the frequency of operation increases, the alignment tolerance between the split-waveguide structures rapidly decreases for devices such as mixers, multipliers and complex passive structures like orthogonal mode transducers. Since silicon micromachined components cannot rely on press-fit alignment pins that are used to align metal waveguide blocks, a new alignment approach based on micromachined silicon compression pins is described.
[0081] We present results of the measurement of passive silicon micromachining waveguide components operating in the WR-1.5 band (500 to 750 GHz). Through lines are first tested to characterize the micromachined waveguide and the waveguide loss is similar to that of metal machined waveguides, and measurement of the 3 dB quadrature hybrid coupler shown in FIG. 15A and FIG. 15B is presented. FIG. 15A is a perspective view of the bottom half of the silicon micromachined 3 dB waveguide hybrid coupler. FIG. 15B is an exploded view of the complete test package.
Fabrication
[0082] The micromachined components are fabricated from a 100 mm diameter, 1 mm thick low-resistivity silicon wafer A combination of photoresist masks and thermal oxide masks are used to etch the patterns in DRIE. A detailed characterization of die silicon etch process has been presented hereinabove. Once the desired number of etches has been performed to create the desired depth of the structure, the component are released by etching from back of the wafer. 2 μm of gold is finally deposited by sputtering.
Wafer Alignment and Silicon Compression Fins
[0083] An important aspect of the operation of split-waveguide circuits is accurate alignment between the two halves. Metal waveguide blocks can use press-fit pins to achieve very high precision placement of alignment pins to the milled features. Silicon is too brittle for such an approach. In addition, when the two halves are mated, the metal of block might be scratched or dented, by an error in position of the alignment pin but silicon will crack, often destroying the wafer.
[0084] To align the wafers, silicon pegs are initially used to align pockets that were etched into each half of the circuit. This technique requires the pin diameter to be several microns smaller than the pocket so that the pin does not damage the wafer when inserted and aligned. This inaccuracy (or “slop”) results in a measured alignment precision of ±6 μm. Tighter fitting pins can improve the alignment precision, but their use dramatically increases the assembly time and the risk of damage to the micromachined package.
[0085] Since the primary source of misalignment when using the stalk silicon pegs is the slop required to insert the pin into the pocket, a compliant silicon pin has developed.
[0086] FIG. 16A is a diagram of the silicon compression pin, showing the relevant dimensions of one embodiment. In various embodiments, the distance between the two projections that are squeezed can be any convenient distance, for example some tens of microns (25 μm, 50 μm, 75 μm, and up to a few hundred microns, such as 100 μm, 125 μm, 150 μm, 200 μm). In the structure shown in FIG. 16A , the outer surface of the silicon alignment pin is circular, but it is believed that any convenient arcuate shape could also be used. FIG. 16B is an image of the compression pin during assembly as it is squeezed by the tweeters to insert it into the alignment pocket or cavity. When released, the pin expands to fill the pocket. A tight fit is ensured by choosing the relaxed pin diameter (or relaxed dimension), d, to be greater than the pocket diameter. FIG. 16C is an image of the compression pin after it has been released into the alignment pocket or cavity. It is recognized that in a compressed state, as when the silicon alignment pin is in contact with the alignment pocket or cavity defined in a layer to be aligned, the outer surface of the silicon alignment pin may no longer be circular in shape, but rather curvilinear or arcuate.
[0087] The spring constant of the pin is controlled by the thickness of the ring, t, and must be designed to allow sufficient compression during assembly while generating as much force as possible to preserve the alignment between the two wafers.
[0088] The package is assembled by mounting two compression pins in the bottom half of the package. The top half of the package is then placed on the bottom wafer and is gently slid in small circles to align the top wafer's pockets with the compression pins. At this point a gentle force is applied and a tiny ‘click’ can be heard when the two wafers come into place. The two wafers are then screwed between two metal blocks which compress the wafers together and provide screw-holes for attaching to waveguide flanges, as shown in FIG. 15 .
[0089] A study of different spring thicknesses (t) and relaxed diameters (d) was conducted to find an optimum design. The alignment precision of each pin design is characterized by measuring the misalignment on four sides of an assembled package 3 times. The positional and angular offsets are then calculated based on the dimensions of the package. Table I shows the different spring thickness and relaxed diameters tested. Positional offsets were all under 2 μm and the angular offsets were all less than 0.06°. This study found a spring thickness of 100 μm and diameter of 1.025 mm provided die lowest positional offset.
[0090] Springs thicker than 100 μm break before they could be compressed into the alignment pocket. The thinnest compression pins failed to produce enough force to maintain the alignment so that when the screws that bold the assembly together are tightened the two wafers twist out of alignment. In an alternative embodiment if the silicon pins are aligned on the through holes in the wafers, a rod that fit inside the pins after the compressive force is released could be used to hold the assembly together, because the rods would eliminate the possibility that the silicon pins could be compressed.
[0000]
Average Positional
t (μm)
d (mm)
Offset (μm)
40
1.020
1.77
80
1.020
0.70
80
1.025
0.77
80
1.030
0.38
100
1.020
0.35
100
1.025
0.24
100
1.030
1.17
[0091] Before different alignment techniques can be compared, a method for measuring the misalignment between wafers is needed. This is done by etching a vernier scale into each half of the component, shown in FIG. 17A . This scale measures the alignment between the two sets of marks by offsetting the spacing of each mark by a known. When two teeth are lined up, one has an indication of the amount of misalignment. This allows rapid evaluation of the misalignment without the need for a calibrated microscope. Precision is limited by the offset distance between each tooth. The 1 μm resolution used in this work proved to be sufficient The test alignment between two wafers in FIG. 17B , indicates that the misalignment between the two halves is less than 2 μm.
Measurement System and Interfacing to Metal Waveguide Components
[0092] The micromachined components are characterized using an Agilent PNA-X network analyzer with VDI WR-1.5 extension heads measuring from 500 to 750 GHz. All measurements are calibrated to the waveguide flange with a TRL calibration kit provided with the extension heads.
[0093] Coupling the micromachined components to metal waveguide presents a difficult challenge and has limited the development of micromachined components for many years. Recently, an effective approach has emerged that couples perpendicularly to the split-waveguide plane so that a UG-386 flange can be patterned into the micromachined structure. While this approach enables alignment to the waveguide with the flange's alignment pins, it relics on a waveguide bend at the input and output ports, introducing uncertainty into the measurement. In addition, the area consumed by the UG-386 alignment pin-hole pattern is large compared to the size of the components testing, so signficant wafer area is wasted.
[0094] FIG. 18A is a perspective drawing of an assembled test apparatus showing the mating of the metal waveguide fixture to the silicon waveguide.
[0095] FIG. 18B is a closeup of the test apparatus showing the E-plane cross-section and illustrating the alignment of the silicon bosses to the metal alignment pockets.
[0096] FIG. 18C is a closeup of the test apparatus showing the H-plane cross section and illustrating the etch angle of the backside silicon etch.
[0097] All these issues can be avoided by measuring from the edge of the wafer as shown in FIG. 18A , but this approach has its own problems. First, the edge of the wafer, which is defined by the etch process, is not flat. Second, there is no area for the UG-386 flange alignment pins to mate, so some other alignment feature is required.
[0098] The latter problem is addressed by tight control over the etch angle defining the front edge of the wafer. This etch is more shallow on the waveguide side of the wafer so a slower etch process can be used that has a smaller etch angle. The bulk of the wafer is then etched from the backside with a faster etch rate process. This fester process suffers from a higher etch angle process, but this is not a concern since the waveguides are not interfacing in this region. The etch angles for the front and back sides of the tested devices are 2° and 5°, respectively. A cross section showing the profile of these etches is shown in FIG. 18C .
[0099] The alignment of the silicon pieces to the metal waveguide is accomplished by bosses etched on the edge of the wafer that insert into pockets milled on custom waveguide flanges. FIG. 18A shows the flange design with the mating silicon component. Alignments the waveguide plane is accomplished by the width of the etched silicon bosses. The out of plane alignment is accomplished by the thickness of the silicon.
[0100] Both of these alignment features are controlled within ±5 μm which results in an overall alignment tolerance of ±7 μm. This is slightly better than the tolerances held by the machining of the flange alignment slip-fit pin holes of ±8 μm and is more than sufficient for these frequencies. The primary drawback to this approach is that the custom flange is only compatible with a single wafer thickness.
Thru-Line Measurements
[0101] Thru lines are fabricated to characterize the waveguide loss and the repeatability of the alignment scheme. Both E and H-plane split waveguides are tested since H-plane waveguide are better indicators of the gap between the two waveguides halves. FIG. 19A is a graph showing a measurement of s 11 vs frequency for the E-plane of the 12.5 mm long split waveguide. FIG. 19B is a graph showing a measurement of s 11 vs frequency for the H-plane of the 12.5 mm long split waveguide. FIG. 19C is a graph showing the measured waveguide loss per millimeter of the E and H-plane split silicon waveguides. The measured loss of a metal machined waveguide and the ideal waveguide loss are included for comparison. The irregularities around 556 GHz are due to the H 2 O absorption line.
[0102] The effect of the gap at the flange interface created by the etch angle is seen as a ripple in the return loss of the thru waveguide measurements. The E-plane waveguide is more affected since the broad-wall is oriented along the etch direction, resulting in a larger gap at the narrow-wall due to the etch angle. The H-plane waveguide has less of a gap since the etch depth is half as much as the E-plane guide.
[0103] The behavior of the return loss across the frequency band is a result of the gap either being on the narrow or broad-wall of the guide. The gap is on the narrow walls of the E-plane split waveguide which can be approximated as a shunt capacitance. For the H-plane. waveguide the gap in the broad-wall presents as a series capacitance.
[0104] FIG. 19C compares the insertion loss per millimeter through the silicon micromachined waveguides to a metal machined waveguide and the calculated ideal waveguide loss with a conductivity of 1.5e7. Remarkably, the H-plane waveguide performs just as well if not better than the E-plane guide, indicating that there is very little gap between waveguide halves. The H-plane waveguide performing better than the E-plane guide in the upper half of the band is a result of the bottom surface of the waveguide etch having a lower roughness than the sidewalls. The RMS roughness of the bottom surface of the etch is measured to be 20 nm, whereas the sidewall is measured to be 110 nm.
Flange Repeatability
[0105] FIG. 20 is a graph showing a comparison of the repeatability of the silicon boss alignment to that of the UG-386 precision flange. FIG. 20 compares the standard deviation of S 11 of the silicon boss alignment scheme with the precision UG-386 flange standard and the drift of the VNA. This standard deviation is calculated as:
[0000]
20
log
10
1
n
∑
i
=
1
n
Γ
i
-
Γ
_
2
where
,
Γ
_
=
1
n
(
∑
i
=
1
n
Re
{
Γ
}
+
j
∑
i
=
1
n
Im
{
Γ
}
)
[0106] Twelve connect-disconnect cycles were included in this measurement. This formulation of the variation between measurements captures the minimum reflection coefficient that can be measured with this alignment scheme.
[0107] FIG. 20 shows that despite the tolerances of the alignment bosses being comparable to that of the metal flange the repeatability is not. There are two possible sources of this reduction in repeatability. The first is that wear of the silicon alignment bosses against the metal pockets could gradually decrease the alignment over multiple connection cycles.
[0108] The second source of error is that the angular alignment of the wafer plane to the flange is not controlled well due to the need for contact to be made to the silicon and not the metal flange as seen in FIG. 18C . There is a gap of 125 μm between the silicon and the metal fixture resulting in possible angular misalignment of ±0.8°. The discontinuity created by the gaps between the silicon and metal flange would be affected by this angular variation. This source of error could be improved with longer alignment bosses at the risk of being more fragile or by reducing the gap between the metal fixture and the flange.
[0109] Although the silicon boss alignment scheme is 20 dB worse than the metal flange alignment, the 40 dB repeatability this approach provides is sufficient for most measurements at these frequencies. More importantly, this measurement shows that the current approach to measuring from the side of the wafer is limited by the reflections at the interface and not the alignment to the mating metal components.
Quadrature Hybrid Coupler
[0110] As a final demonstration that complex, waveguide circuits can be fabricated and measured with our silicon micromachining process, a 3 dB quadrature hybrid coupler operating from 500 to 600 GHz is tested. The circuit is a 5 branch Chebyshev design, which is then tuned in HFSS to compensate for the capacitive effects of the T-junctions.
[0111] As shown in FIG. 21 , the coupler is measured with only two-ports at a time, so the other two ports must be matched. To match the isolated port, a waveguide wedge load was inserted into the isolated port. This load is a 5° tapered wedge load ground from Emerson & Cumming Eccosorb MF-116 material. The other uncoupled port is matched with a load provided in the calibration kit of the VNA through one of the silicon mating flanges as shown in FIG. 21 .
[0112] FIG. 21 is an image of the waveguide hybrid measurement apparatus.
[0113] FIG. 22 A is a graph of the measured S-parameters as a function of frequency for a 3 dB hybrid coupler. As seen in FIG. 22A the return loss is less than 20 dB and the amplitude balance is less than 1 dB across designed band. The isolation is measured between the direct and coupled ports since the wedge load is mounted in the isolated port. The minimum isolation is 16 dB, which is limited by the reflection of the wedge load.
[0114] FIG. 22B is a graph of the phase balance a function of frequency between the direct and coupled ports, which by design should be 90°±1°. The measured phase imbalance is less than 10° throughout most of the band. This offset from the design is likely due to variations in the silicon surface between the direct and coupled ports, creating different phase shifts through the flange interface.
[0115] While the alignment pins described herein have been constructed from silicon, it is believed that other materials of construction could also be used to fabricate such alignment pins. In particular any material that can be fabricated with good surface smoothness, for example having a surface roughness measured in tens of microns, and that can be compressed as described hereinabove can be used.
Definitions
[0116] Unless otherwise explicitly recited herein, any reference to an electronic signal or an electromagnetic signal (or their equivalents) is to be understood as referring to a non-transitory electronic signal or a non-transitory electromagnetic signals.
Theoretical Discussion
[0117] Although the theoretical description given herein is thought to be correct, the operation of the devices described and claimed herein does not depend upon the accuracy or validity of the theoretical description. That is, later theoretical developments that may explain the observed results on a basis different from the theory presented herein will not detract from the inventions described herein.
[0118] Any patent, patent application, patent application publication Journal article, book, published paper, or other publicly available material identified in the specification is hereby incorporated by reference herein in its entirety. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material explicitly set forth herein is only incorporated to the extent that no conflict arises between that incorporated material and the present disclosure material. In the event of a conflict, the conflict is to be resolved in favor of the present disclosure as the preferred disclosure.
[0119] While the present invention has been particularly shown and described with reference to the preferred mode an illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be affected therein without departing from the spirit and scope of the invention as defined by the claims.
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A silicon alignment pin is used to align successive layer of component made in semiconductor chips and/or metallic components to make easier the assembly of devices having a layered structure. The pin is made as a compressible structure which can be squeezed to reduce its outer diameter, have one end fit into a corresponding alignment pocket or cavity defined in a layer of material to be assembled into a layered structure, and then allowed to expand to produce an interference fit with the cavity. The other end can then be inserted into a corresponding cavity defined in a surface of a second layer of material that mates with the first layer. The two layers are in registry when the pin is mated to both. Multiple layers can be assembled to create a multilayer structure. Examples of such devices are presented.
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[0001] This application is a Continuation-In-Part of U.S. patent application Ser. No. 12/405,956, filed Mar. 17, 2009, which is a Continuation of U.S. patent application Ser. No. 11/161,933, filed Aug. 23, 2005, now issued U.S. Pat. No. 7,503,083, the entire disclosures of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] A strainer in the plumbing field is the mechanism in the bottom of a sink, bathtub, or the like through which waste water flows from the receptacle. Strainers usually have valves or the like which control the flow of water therethrough. Most of these valve assemblies are threadably mounted within a threaded aperture located in the strainer.
[0003] Existing strainers have a vertically disposed externally threaded sleeve which engage corresponding threads on a fitting adjacent a vertically disposed aperture in the bottom of the water receptacle. The upper end of the sleeve terminates in a circular horizontal flange which engages and is sealed to the bottom of the receptacle around the aperture in the bottom of the receptacle. A hub with a threaded bore and with radially extending spokes is often located in a horizontal plane in the bottom of the strainer to support various closure valves.
[0004] Occasionally it is necessary to change the strainer of a given receptacle because the flange thereof has become tarnished, disfigured, or because the flange is incompatible esthetically with the owner's sense of ornamentation. Removal of the strainer is often a difficult task, particularly when the strainer has been in place for a long time. Conventional tools are typically insufficient for use in removal of the strainer. Further, there is a possibility that the threads of the replacement strainer will not be compatible with the threads of the fitting or bushing associated with the aperture of the receptacle. In addition, when the strainer is removed there is nothing to retain the back drain system and it falls away.
[0005] Some attempts have been made to place a substitute flange over the existing flange by providing structure whereby the substitute flange can be threadably secured to threaded bores of the strainer which originally threadably received the valve assembly of the strainer. This approach to the installation of a substitute flange is not satisfactory because variations of thread sizes in the original strainers are often incompatible with the thread sizes of the substituted flange adapter.
[0006] It is therefore an aspect of this invention to provide a cover and method for covering the flange of an existing strainer without removing the existing strainer.
[0007] A further aspect of this invention is to provide a cover and method for covering the flange of an existing strainer which will permit easy installation, and which will be well within the ability of those not being skilled in the plumbing art.
[0008] These and other aspects will be apparent to those skilled in the art.
SUMMARY OF THE INVENTION
[0009] A waste water insert has a cylindrical wall surrounding a cylindrical bore. A flange extends outwardly from the upper end of the wall and has a lip formed on its outer periphery.
[0010] The flange of the waste water insert is superimposed over the flange of a waste water strainer located in a bathtub, sink or the like. The lip at the outer perimeter of the flange of the insert fits over the outer periphery of the horizontal flange of the waste water strainer to center the insert on the strainer. The cylindrical wall of the insert extends downwardly through the cylindrical wall of the waste water strainer with the two walls being spaced from each other by virtue of the cylindrical wall of the insert having a smaller diameter than that of the strainer. The cylindrical wall of the strainer extends below the cylindrical wall of the insert, and has a lower circular edge. One or more grooves are positioned within the cylindrical wall of the insert that receive one or more resilient ring members that engage the cylindrical wall of the strainer.
[0011] It is one aspect of the present invention to provide an insert with a wall that has a portion that engages the wall of the waste water strainer. More specifically, as described above, some embodiments of the present invention employ one or more grooves that receive one or more resilient ring members to engage the wall of the waste water strainer. One skilled in the art, however, will appreciate that there are multiple ways to engage the wall of the waste water strainer. For example, one embodiment of the present invention employs seals that do not require a groove. That is, enlarged seals, broken seals, shim seals, and angled seals are contemplated. In some embodiments, the wall of the strainer is comprised of two different materials, such as a steel or aluminum flange and interconnected plastic or rubber wall.
[0012] It is a similar aspect of the present invention to provide an insert having a wall that has one or more engaging lips. In operation, an outer edge of the lip engages the cylindrical wall of the waste water strainer to center the insert. A centering feature may not comprise a continuous ring, but may instead include discontinuous extensions that act in concert to center the device. The wall engaging portions, e.g. lip(s), may be located adjacent to the insert flange, the end of the insert's wall, between the flange and the end of the wall, or a combination thereof. Frictional contact between the engaging lip and the strainer wall helps maintain the position of the insert. In some embodiments of the present invention, the insert's wall is conical wherein the diameter at a lowermost portion of the insert is greater than that of the opening in the flange. It is contemplated that insertion of the insert's cylindrical body into the strainer would require some deflection of the insert wall. After insertion, the wall of the insert will deflect outwardly to firmly engage the strainer wall. One of skill in the art will appreciate that a plurality of walls or tabs may be provided as opposed to a continuous insert wall. In still other embodiments of the present invention, the wall of the insert is angled or conical such that the lowermost portion has the smallest diameter. Here, a ring may be inserted into the insert to splay the insert wall outwardly to engage the strainer wall.
[0013] Still other embodiments of the present invention employ an adhesive positioned between the insert flange and the flange of the waste water strainer or set screws to secure the insert in place.
[0014] The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detail Description, particularly when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions.
[0016] FIG. 1 is a partial perspective view of a bathtub with a waste water strainer located in the bottom thereof;
[0017] FIG. 2 is an exploded view showing a preliminary step in mounting the waste water insert onto the existing waste water strainer;
[0018] FIG. 3 is an unexploded cross sectional view of the assembly shown in FIG. 2 ;
[0019] FIG. 4 is an unexploded cross sectional view similar to that of FIG. 3 showing a modified form of insert;
[0020] FIG. 5 is a cross sectional view of an assembly of an insert of another embodiment of the present invention that employs an enlarged seal;
[0021] FIG. 6 is a cross sectional view of an insert of another embodiment of the present invention that employs a plurality of buttons;
[0022] FIG. 7 is a cross sectional view of an insert of an alternate embodiment of the present invention that employs a plurality of seal shims;
[0023] FIG. 8 is a cross sectional view of FIG. 7 ;
[0024] FIG. 9 is a cross sectional view of an insert of another embodiment of the present invention that employs an angled sealing member;
[0025] FIG. 10 is a cross sectional view of an insert of another embodiment of the present invention that employs an engaging lip;
[0026] FIG. 11 is a cross sectional view of an insert of another embodiment of the present invention that employs an outwardly extending conical portion;
[0027] FIG. 12 is a cross sectional view of an insert of another embodiment of the present invention that employs an inwardly extending conical portion;
[0028] FIG. 13 is a cross sectional view of an insert of another embodiment of the present invention that employs adhesives;
[0029] FIG. 14 is a cross sectional view of an insert of another embodiment of the present invention that employs at least one set screw;
[0030] FIG. 15 is a cross sectional view of an insert of another embodiment of the present invention that receives an edge engagement member for selective engagement with a strainer body;
[0031] FIG. 16 is a cross sectional view of the insert of FIG. 15 that receives an edge engagement member of an alternate configuration;
[0032] FIG. 17 is a bottom plan view of the insert of FIG. 15 showing the edge engagement members of FIG. 15 or 16 ;
[0033] FIG. 18 is a bottom plan view of the insert of FIG. 15 that receives an edge engagement member that has an extended outer portion;
[0034] FIG. 19 is a cross sectional view of the insert of one embodiment of FIG. 15 that receives a continuous edge engagement member;
[0035] FIG. 20 is a cross sectional view of the insert of FIG. 15 that receives an edge engagement member similar to that shown in FIG. 19 but that has elongated inner and outer portions;
[0036] FIG. 21 is a bottom plan view of the insert in combination with the edge engagement member of FIG. 19 or FIG. 20 ; and
[0037] FIG. 22 is a bottom plan view of the insert of FIG. 15 associated with an edge engagement member that has a plurality of grooves.
[0038] To assist in the understanding of one embodiment of the present invention, the following list of components and associated numbering found in the drawings is provided below:
[0000]
#
Component
10
Fluid compartment
12
Bottom
14
Bottom surface
16
Waste water aperture
20
Waste water strainer
22
Upper end
24
Flange
26
Outer perimeter
28
Cylindrical wall
30
Threads
34
Insert
36
Flange
38
Lip
40
Cylindrical wall
42
Center opening
43
Space
44
Groove
46
Resilient ring member
50
Raised surface
52
Resilient ring member
54
First portion
58
Second portion
60
Conical portion
66
Enlarged seal
70
Tapered surface
74
Button
78
Holes
82
Shims
86
Indentation
90
Angled seal
94
Lip
98
Conical wall
102
Inner lip
106
Ring
110
Adhesive
114
Set screw
118
Edge engagement member
122
Outer portion
126
Finger
130
Inner surface
134
Bottom edge
138
Extended outer portion
142
Inner portion
146
Outer portion
150
Groove
[0039] It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
DETAILED DESCRIPTION
[0040] The numeral 10 designates a fluid compartment or receptacle such as a tub or a sink. Compartment 10 has a bottom 12 with an interior bottom surface 14 . A waste water aperture 16 is located in bottom 12 .
[0041] A waste water strainer 20 is shown in FIG. 2 . Strainer 20 has an upper end 22 from which a circular flange 24 extends. The outer perimeter 26 of flange 24 engages the interior bottom surface 14 ( FIG. 1 ) surrounding aperture 16 . The strainer 20 has a downwardly extending cylindrical wall 28 and external threads 30 . The typical closure valves which may be associated with strainer 20 have not been shown.
[0042] The numeral 34 designates a waste water insert. Insert 34 has a flange 36 with the periphery thereof terminating in a downwardly extending lip 38 . As best shown in FIG. 3 , the lip 38 extends downwardly and over the outer perimeter 26 of flange 24 of strainer 20 . The lip 38 engages the bottom 12 of compartment 10 when installed.
[0043] Insert 34 has a downwardly extending wall 40 which surrounds a center opening 42 . The diameter of wall 40 is less than the diameter of the cylindrical wall 28 of strainer 20 so that a space 43 ( FIGS. 3 and 4 ) exists between the two walls. The lip 38 on the outer perimeter of the flange 36 of insert 34 centers the cylindrical wall 40 within the cylindrical wall 28 of strainer 20 ( FIG. 3 ). In one embodiment, the waste water insert 34 includes a wall 40 with a cylindrical first portion 54 and a cylindrical second portion 58 with a conical portion 60 therebetween. The diameter of the cylindrical first portion 54 is greater than the diameter of the cylindrical second portion 58 such that the space 43 is reduced adjacent to the cylindrical first portion 54 .
[0044] The cylindrical wall 40 extends downwardly and has a first groove 44 in the lower end. The groove 44 receives a resilient ring member 46 that engages the cylindrical wall 28 of the strainer 20 to hold the insert 34 in place. In one embodiment, the resilient ring member 46 is an O-ring.
[0045] Alternatively, the waste water insert 34 , as shown in FIG. 4 , has a second groove 48 in spaced relation to the first groove 44 with a raised surface 50 therebetween. The second groove 48 receives a second resilient ring member 52 that also engages the cylindrical wall 28 of strainer 20 . Additional grooves and rings may be added as desired.
[0046] The insert is installed by inserting the cylindrical wall 40 of the insert 34 into the opening 16 ( FIG. 2 ) of the strainer 20 until the insert is in place. At this point the resilient ring or rings of the insert will engage the cylindrical wall 28 of the strainer 20 to hold the insert 34 in place. No tools are required and the inserts are quickly, easily, and securely installed to achieve their required purpose.
[0047] FIG. 5 shows another embodiment of the present invention where the insert 34 is used in conjunction with an enlarged seal 66 . Here, the seal 66 extends from a lower surface of the flange 36 to a lowermost portion of the insert 34 . One skilled in the art, however, will appreciate an enlarged seal 66 of any shape may be employed. The seal 66 blocks the space 43 between the insert 34 and the strainer 20 and centers the insert 34 . The seal 66 may have a tapered surface 70 to facilitate insertion into the waste water strainer 20 .
[0048] FIG. 6 shows an insert 34 of the present invention that uses a plurality of resiliently deflectable buttons 74 , which are integrated or inserted into holes of the insert 34 to help maintain the insert's 34 position within the strainer 20 . For example, an insert 34 having a plurality of holes 78 radially drilled through the wall 40 may be provided. The buttons 74 , which are preferably made of an elastomeric material, are inserted within the holes 78 and extend out from the wall 40 such that the effective outer diameter of the wall 40 is increased to correspond with the inner diameter of the strainer 20 . Thus, the frictional engagement between the buttons 74 and the strainer 20 help secure the insert 34 within the strainer 20 . Although three buttons 74 are shown, one skilled in the art will appreciate that any number of buttons may be integrated into the insert 34 .
[0049] Referring now to FIGS. 7 and 8 , another embodiment of the present invention is shown that employs a plurality of elongated shims 82 . Here, the strainer 20 includes a wall 40 having a plurality of indentations 86 that receive elongated elastomeric shims 82 . The shims 82 are similar to that of the buttons described above and are sandwiched between the strainer wall 28 and the wall 40 of the insert 34 to hold it in place. Here, the insert wall 40 includes a plurality of indentations 86 for receiving the shims 82 . One skilled in the art, however, will appreciate that the strainer wall 28 may have openings that extend completely therethrough that receive the shims 82 . Further, although three shims 82 are shown, one skilled in the art will appreciate that any number of shims 82 may be employed without departing from the scope of the invention. The shims 82 may extend from the lower portion of the insert to the underside of the flange 36 or only extend a portion of the length of the insert wall 40 as shown.
[0050] FIG. 9 shows an insert 34 that is associated with a strainer 20 with an angled seal 90 . The angled seal 90 may rest in a groove incorporated in the insert wall 40 .
[0051] Referring to FIGS. 10-12 , another embodiment of the present invention is shown where the insert 34 includes an engaging lip 94 positioned at the lowermost portion of the wall 40 . The lip 94 engages the strainer wall 28 and frictionally aligns the insert 34 to help maintain the position of the insert 34 within the strainer wall 28 . In one embodiment of the present invention shown in FIG. 11 , the insert wall 40 is angled outwardly (2) and thus must be deflected inwardly for insertion into the strainer wall 28 . When the force applied to deflect the wall 40 inwardly is removed the insert wall 40 will deflect outwardly, thereby increasing friction between the lip 94 and the strainer wall 28 . To facilitate insertion of the angled wall, a taper (not shown) may be provided on the lip 94 so that when engaged onto the strainer wall 28 , the insert wall 40 will be deflected inwardly. Furthermore, those of skill in the art will appreciate that opposed to a continuous insert wall 40 , many elongated tabs or walls may be provided.
[0052] FIG. 12 is an alternate embodiment wherein a conical wall 98 is provided. The conical wall 98 includes an inner lip 102 that receives a sliding ring 106 . In operation, the sliding ring 106 is placed into the strainer wall 28 and moved downwardly, thereby deflecting the sides of the insert wall 40 outwardly to place the lip 94 in engagement with the strainer wall 40 . Again, one skilled in the art will appreciate that opposed to a continuous wall, many tabs or subwalls may be provided by this embodiment of the present invention.
[0053] FIG. 13 , an alternate embodiment of the present invention is shown wherein an adhesive 110 is used between the insert flange 36 and the strainer body flange 24 . An engaging lip 38 may also be included to help center the insert 34 with respect to the strainer body 20 .
[0054] FIG. 14 shows yet another embodiment of the present invention where a plurality of set screws 114 are used to secure the insert 34 into the strainer 20 . An engaging lip 38 may also be included in this embodiment to help center the insert 34 into the strainer 20 . In view of the foregoing, one of skill in the art will appreciate that the methods of inserting and securing the insert into the strainer may be combined. More specifically, embodiments employing the set screw 114 or an engaging lip 38 may also include seals, buttons or other centering and sealing mechanisms described herein.
[0055] FIGS. 15-22 show an insert 34 of another embodiment of the present invention that is positioned within the waste water strainer 20 by way of one or more edge engagement members 148 . The edge engagement members have an outer portion 122 that selectively engages the waste water strainer 20 . The edge engagement member 118 also includes a finger 126 that interfaces with the inner surface 130 of the insert 34 . The outer portion 122 and finger 126 are spaced to provide a gap for receipt of the cylindrical sidewall 40 of the insert 34 . In one embodiment of the present invention, the edge engagement member 118 is abutted against a bottom edge 134 of the cylindrical sidewall 40 . The gap provided between the finger 126 and the outer portion 122 may be slightly smaller than the thickness of the cylindrical sidewall 40 to provide an interference fit between the edge engagement member 118 and the cylindrical sidewall 40 .
[0056] Referring specifically to FIGS. 15 and 16 , the edge engagement member 118 may have a bulbous outer portion 122 for selective engagement to the strainer body 20 . In operation, a plurality of edge engagement members 118 are interconnected to the cylindrical sidewall 40 and firmly secured to the bottom edge 134 thereof. The insert 34 is then forced within the strainer body 20 , which deflects the outer portions 122 of the edge engagement members inwardly. After insertion, the resilient nature of the edge engagement members 118 of one embodiment will expand to secure the insert 34 . The outer portion may be tapered to facilitate insertion into the strainer body. Further, as shown in FIG. 16 , the fingers 126 may be elongated so that more of the inner surface 130 is contacted. Although three edge engagement members 118 are shown, one of skill in the art will appreciate that any number of edge engagement members 118 may be employed without departing from the scope of the invention.
[0057] FIG. 17 is a bottom plan view of the insert 34 showing a plurality of edge engagement members 118 associated with the bottom edge 134 of the cylindrical sidewall 40 . FIG. 18 shows an alternative configuration where an extended outer portion 138 is provided that increases surface contact with the strainer body. That is, the extended outer portion provides 360° engagement between the insert 34 and the strainer body. One of skill in the art will appreciate that the extended outer portion may be non-continuous to provide less than 360° of contact.
[0058] FIGS. 19 and 20 show an edge engagement member 118 of an alternative configuration wherein an inner portion 142 is provided that contacts the inner surface 130 of the insert 34 . Similar to the embodiments described above, an outer portion 146 is spaced from the inner portion 142 . The outer portion 146 may be bulbous, of a constant cross section, or tapered. As shown in FIG. 20 , the outer portion 146 and the inner portion 142 may be elongated to increase the amount of contact area between the cylindrical sidewall 40 and the strainer body 20 .
[0059] FIG. 21 is a bottom plan view of an insert 34 associated with the edge engagement member 118 of FIGS. 19 and 20 . FIG. 22 is a bottom plan view of an edge engagement member of another embodiment of the present invention where cut-outs or grooves 150 are provided that facilitate interconnection with the insert 34 . The grooves 150 may be of such a depth as to expose the inner surface 130 of the cylindrical sidewall 40 .
[0060] While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims.
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A waste water insert has a wall surrounding a vertical bore. A horizontal flange extends outwardly from the upper end of the wall and has a lip formed on its outer periphery. The horizontal flange of the waste water insert is super-imposed over the horizontal flange of a waste water strainer located in a bathtub, sink or the like. The wall of the insert extends downwardly through the cylindrical wall of the waste water strainer with the two walls being spaced from each other by virtue of the cylindrical wall of the insert having a smaller diameter than that of the strainer.
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[0001] The present invention relates to, claims priority from, and expressly incorporates by reference U.S. Provisional Appl. Ser. No. 60/521,570 filed May 26, 2004, entitled “Method Of Increasing DDR Memory Bandwidth In DDR SDRAM Modules.”
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to memory devices, and more particularly relates to increasing the bandwidth of DDR (double data rate) SDRAM (synchronous dynamic random access memory) modules.
[0004] 2. Description of the Related Art
[0005] In the past, the widely held opinion was that the SPD (Serial Presence Detect) should be optimized primarily for the lowest possible timings of the CAS (column access strobe) latency. Less care was taken in the remaining three timings—t RP (RAS Precharge (precharge-to-activate delay)), t RCD (RAS to CAS delay), and t RAS (Active to Precharge delay)—accordingly the overall bandwidth of the module was not optimized to the degree possible.
[0006] By minimizing only the CAS latency, the module has a lower bandwidth, meaning that actual data transfer to and from the module is less than it could be.
SUMMARY OF INVENTION
[0007] The present invention provides a method of increasing DDR memory bandwidth in DDR SDRAM modules.
[0008] DDR memory has an inherent feature called the Variable Early Read command, where the read command is issued one CAS latency before the end of an ongoing transfer. By using the Variable Early Read command the effect of the CAS latency is minimized in terms of the effect on bandwidth. The enhanced bandwidth technology achieved with this invention optimizes the remaining two access latencies (t RP and t RCD ) for optimal bandwidth. These optimizations in the SPD allow for much better bandwidth in real world applications
BRIEF DESCRIPTION OF DRAWINGS
[0009] The present invention will be described, by way of example, with reference to the accompanying drawings, in which:
[0010] FIG. 1 is a schematic overview of an internal bank of a memory device: After a row has been selected and activated (highlighted area on left), the Column Address Strobe (CAS) can select a block of logically coherent addresses within this row (right). The number of page hits is limited among other factors by the limited number of column addresses within each page. Note that, per DRAM convention, rows are running vertically and columns horizontally.
[0011] FIG. 2 is a timing diagram for two modules, one running at t RCD − 4 .CL− 2 . 5 , t RP − 4 (bottom) and the second with t RCD − 3 , CL− 2 . 5 −t RP − 2 (top) showing two consecutive bursts of 8 from two different pages which is one of the most common scenarios in real world applications. The effective bandwidth is the ratio between data transfers (diamonds): NoOps (arrows) which, in the case of EB is 8:7 without EB, this ratio is 8:10, meaning that every transfer of 16 bits is penalized with either 7 or 10 subsequent bus idle cycles (Abbreviations used: t RCD ; RAS-to-CAS delay; CL: CAS latency; t RP : precharge-to-activate delay; Clk: clock; Act: row activate command; Rd: read command; Pr: Precharge command, NoOp: No Operation).
[0012] FIG. 3 shows the effect of issuing an Early Read Command on back-to-back transactions of consecutively requested data blocks within the same page. Following one Row Activate Command, three Read commands are given at a CAS Latency of either 2, 2.5 or 3. The squares are the data transfers that belong to the square-shaped Read Command. The graph shows that the net effect of increasing the CAS latency is a single cycle delay within a string of (in this case) 12 consecutive transfers but no degradation of bandwidth. The double-arrows indicate the CAS latency which is amended by moving the read command further to the left (relative to the end of the previous burst). (Abbreviations used: Clk: clock; Act: row activate command; Rd: read command; Pr: Precharge command, CL: CAS Latency).
[0013] FIG. 4 illustrates an alternate embodiment of the present invention.
DETAILED DESCRIPTION
[0014] The present invention provides enhanced bandwidth (EB) technology as a means of increasing memory bandwidth through the optimization of memory latencies for the best possible interaction between the system memory and the chipset and memory controller. Through thorough analysis of memory traffic and benchmark results under various operating conditions as defined by different memory latency settings in the CMOS setup of the BIOS, we have pinpointed the bottlenecks relevant for performance. Some conventional wisdom regarding some memory latencies were also found to no longer hold true. Using those findings, we redesigned our memory products to be optimized for delivering the highest possible bandwidth to any computer system.
[0015] Memory bandwidth is influenced by two major factors; frequencies and latencies. Transfer frequency, or data rate, is important since the theoretical peak bandwidth is defined by the bus width (in number of bits) multiplied by the frequency. Theoretical peak bandwidth is defined as the physical limit of the number of bytes that can be transferred from sender to receiver without counting idle bus period. Thus, with a fixed bus width, the total theoretical peak bandwidth is a factor of the operating frequency alone. In real life, however, this equation is not adequate. No computer system, regardless of how well it is optimized, is able to achieve peak transfer rates in a sustained fashion since only a limited number of back-to-back transactions can be carried out. Initial access latencies, along with memory-internal parameters such as page boundaries within the memory devices, pose an effective barrier to the actual peak bandwidth.
[0016] Some memory benchmarks work around these problems through implementation of prefetch algorithms to utilize the in-order queues, i.e., pipelined prefetch buffers on the chipset, along with bank interleaving on the memory device itself. The result is approximately 90 to 95% bus utilization based on the idea that recurrent access latencies can be hidden behind already pipelined data output from either I/O buffers on the DIMMs or the chipset. This is why some benchmarking programs return “Inflated” bandwidth scores that do not accurately reflect real world applications.
[0017] However, in most real world applications, only a small fraction of accesses stay “In page,” meaning that the requested data are found within the address range of the currently open memory page. The ratio of page hits vs. page misses varies from one application to another. In network router and server applications, accesses are mostly random and result in almost no page hits, whereas a memory address pattern analysis we conducted demonstrated that in streaming video editing or gaming applications the number of page hits can reach 70 to 80%.
[0018] In most cases, the memory access pattern follows the general scheme that one page is opened with a row access and, subsequently, a small number of column addresses within that page get hit. Each page hit specifies a block of 64 column addresses that results in an output of eight transfers of eight bits each (in the case of an x8 memory device). In Interleaved mode, subsequent blocks do not need to follow a contiguous column address pattern as long as the sequence is predetermined. This is important for the understanding how, within a given page, the Column Address Strobe (CAS) can jump back and forth between higher and lower addresses without missing the page. However, given the limited number of column addresses within each page, there: is a limit to how many page hits can occur before a page boundary is finally met and the next memory request will miss the currently open page. Every such page miss will result in a complicated sequence of events. First, the currently open page must be closed. Since a read from a DRAM memory cell is destructive, data that were read out to the primary sense amplifiers within the array must be written back to the memory cells, after which the RAS lines need to be precharged: Closing a page takes between two and four clock cycles, during which time no other page can be activated. Only after a “virgin” state of the memory array has been reestablished can the next Row Activate command be issued. The performance penalties stemming from a precharge in an open-page situation will vary in severity depending on the number of latency cycles associated with the precharge-to-activate delay (t RP ), because the number of number of latency cycles of t RP will determine the number of “No Operation” (NoOp) cycles during which no data can be transferred. Keep in mind that with a DDR protocol, the penalties are doubled since each idle cycle causes a delay or miss of two transfers resulting in a severe reduction in effective bandwidth.
[0019] Before the next read (page hit) can occur, another page needs to be opened which includes a sequence that is the reverse of the precharge. First, a row address is decoded, followed by the row access strobe moving to the respective row address to pull the signal low for a logical true. This, in turn, opens the pass-gates to all memory cells within this row. The memory cells then discharge their contents to the primary sense amplifiers. After a voltage differential for each bitline pair has been sensed and amplified, a read command is issued. The time taken for this entire process is the RAS-to-CAS delay (t RCD ). Both t RP and t RCD are the two main factors that cause a reduction in effective memory bandwidth.
[0020] On average, there are three to four page hits following an initial page access. In those cases, the CAS latency (CL) determines the number of penalty cycles incurred between the read command and the start of data output to the bus. However, a read command can be issued concurrent with an ongoing data burst. This means that the read command for the next data burst can be issued before an ongoing data transfer is exhausted with the result that the latency cycles are hidden behind the previous transfer. CAS latency (CL), therefore plays a much smaller role in limiting bandwidth than RAS-to-CAS Delay or Precharge latency.
[0021] The diminished importance of CL is in contrast, though, to conventional wisdom that has labeled CL as the most important memory latency. However, this used to hold true for single data rate SDRAM, which is the reason why, until recent years, most memory manufacturers only listed their CL specifications and not the other latency parameters.
[0022] EB technology further capitalizes on another feature possible in DDR through the Variable Early Read Command. Early Read Command compensates for higher CAS latencies by changing the time at which a read command is issued relative to an ongoing transfer. More precisely, if there is an ongoing burst of data with a CL- 2 , the read command is issued two cycles before the end of the burst with the result that the next data output seamlessly follows the previous. With a CL- 3 , the read command is issued three cycles before the end of the ongoing transfer and this scheme can be extended to higher CAS latencies as well. Therefore, within any page, the bandwidth reduction by an increased CL is negligible.
[0023] EB technology series uses low t RP and t RCD latencies in combination with a Variable Early Read Command to allow for the highest possible effective data bandwidth. In most applications, the 2.5-2-3 (CL−t RP −t RCD )will deliver bandwidth that is indistinguishable from CL- 2 modules, and t RP and t RCD latencies that are both lower than the CAS latency CL, such as 2.5,-2,-2 (CL−t RP −t RCD ), will work even better.
[0024] Current computer technology uses a dedicated memory controller that is either part of the chipset or else integrated directly on the CPU itself. This memory controller generates the addresses and commands at pre-specified timing intervals. However, one embodiment of the current invention, illustrated in FIG. 4 , uses a memory controller integrated on the memory module 400 that includes a data buffer 410 and is fanning out to the individual memory integrated chips 420 to generate the addresses and commands at the specified latencies. Such a fully buffered module, connected to the core logic 500 via a high-speed serial bus 510 will see the same or better improvement of bandwidth according to the method of the invention.
[0025] While the invention has been described in terms of a specific embodiments. It is apparent that other forms could be adopted by one skilled in the art. Accordingly, it should be understood that the invention is not limited to any specific embodiment. It should also be understood that the phraseology and terminology employed above are for the purpose of disclosing the invention, and do not necessarily serve as limitations to the scope of the invention.
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The present invention provides a method of increasing DDR memory bandwidth in DDR SDRAM modules. DDR memory has an inherent feature called the Variable Early Read command, where the read command is issued one CAS latency before the termination of an ongoing data burst By using the Variable Early Read command the effect of the CAS latency is minimized in terms of the effect on bandwidth. The enhanced bandwidth technology achieved with this invention optimizes the remaining two access latencies (t RP and t RCD ) for optimal bandwidth. These optimizations in the SPD allow for much better bandwidth in real world applications.
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CROSS REFERENCE
This is a Continuation-In-Part application of U.S. application based on PCT10/089,105, filed Feb. 19, 1998, which is in turn a Continuation-In-Part application of U.S. Ser. No. 08/517,259, filed Aug. 23, 1995 for OPEN HELICAL ORGANIC TISSUE ANCHOR AND METHOD OF FACILITATING HEALING now U.S. Pat. No. 5,662,683.
FIELD OF THE INVENTION
The present invention relates to tissue anchors as well as to methods of promoting healing or repairing hard or soft, living, organic tissue using an open helical anchor. Further, the invention relates to a method of making the tissue anchor. In a further embodiment, the helical anchor comprises a filament which has a taper along its longitudinal length.
BACKGROUND OF THE INVENTION
The present invention relates to an anchor (or connector) which can be used to fasten organic tissue in close proximity in order to afford the tissue the opportunity to heal. The anchor of the present invention can be used to anchor and clamp dense, regular and/or dense, irregular connective tissue in place in relation to bone. The anchor can also be used for tissue transplants, i.e., for holding tissue in fixed relation to bone, and can also be used in bone as a buttress, such as for buttress plating techniques, or to fasten pieces of bone together as a screw substitute. Further, the anchor can be used in soft tissue applications. Thus, as used herein “tissue anchor” relates broadly to the invention used as a screw, clamp, or anchor in the narrow sense of the word which holds organic tissue, i.e. bone to bone, soft tissue to bone, or soft tissue to soft tissue.
As compared to the prior art, the anchor of the present invention allows a method of holding together organic tissue with minimal disruption to the biological environment or to the tissue itself. For example, prior art devices and methods customarily require a large hole for insertion of the anchoring device, causing not only structural damage to the implantation site, but also inflicting further trauma to the biological site such as generating heat, introducing further possibility for infection, and destroying bone which may be needed to help heal the repaired area. Such trauma is amplified in cases where prior art devices malfunction during the implant procedure. Hooks or screws can get stuck and further obscure the operating site or require tedious removal.
The anchor of the present invention may be very useful for applications such as anchoring ligaments or tendons when performing soft tissue surgical reconstruction, rupture tendons, or torn ligaments, in which the surgeon wants to reconstruct or repair connective tissue with respect to the bone or with respect to other soft tissue.
The anchor device functions to hold together the tissue (such as connective tissue to bone) for a relatively limited time frame e.g., six to twenty-six weeks, during which time the biological system will heal.
The anchor of the present invention can be used with advantage in many of the same applications in which cancellous screws are used in addition to applications in which traditional prior art anchoring techniques are unsatisfactory. The anchor of the present invention is far less invasive to implant than cancellous screws or hook-style anchors, i.e., the implant has a minimized mass, the insertion point is small relative to the size of the implant, and the device involves minimal removal of native tissue. In addition, the area of bone or other tissue which is needed to secure the present invention can be of poorer quality than for prior art devices.
Additionally, the anchor of the present invention can be removed and minimally reangulated in order to utilize the same surgical site. Prior art devices require a large hole (relative to implant size) to be drilled in order to implant the device, and once the hole is contaminated by malfunction or misalignment of the device, it is necessary to drill another hole far enough away to achieve stability in a new location. Given the surgical context, this is extremely inconvenient.
The anchor of the present invention can be used in methods of ligament, tendon, or other tissue repair. For example, the anchor can be used for a method involving cartilage transplant and it can be used alone or in conjunction with a plate for a method of buttressing bone where the quality of bone may be questionable due to trauma or degenerative disease. The anchor may be used in methods of fixation involving connective tissue repair and replacement and may be inserted using a plunge-handle or “T” handle inserter which utilizes longitudinal travel in order to achieve rotational insertion. The handle and insertion tool may be a standard screwdriver or a jig-outer cannula system for a hex head or headless helix, respectively.
Specifically, the anchor is used in a ligament or tendon in which a pilot hole, having a diameter much smaller than the outer diameter of the helical anchor, is drilled in the cortex of the bone. The angle of implantation can be varied as necessary. The anchor is subsequently mounted or loaded into the insertion tool, threaded into the pilot hole, and screwed into the bone an appropriate distance so that the anchor head can be accessed but is not obtrusive. The ligament or tendon is attached to the anchor, such as by suturing.
In addition, the anchor of the present invention can be used to anchor plates and is particularly useful in instances where the bone is of poor quality. The head can be a bend in the wire which forms a cross bar and which can be implanted using a slotted instrument. A particularly desirable head for some applications has an internal hex slot to permit the anchor to be implanted. In addition, the head has a transverse through slot to hold a suture. The head has a low, rounded profile with a distal stem which fits inside a ring of the helix and is laser-welded thereto. In an alternative embodiment, the anchor has a solid cylindrical head which extends from the spiral and has the same outer diameter. This head also has an internal torque receiving hexagon, which has a hole in the center of the bottom surface of the hex shaped recess. This hole allows for cannulation for implantation. Further, the head has a hole (or more precisely, two aligned holes), in a direction transverse to the longitudinal axis of the spiral to allow a suture to be attached to the head. For the screw used with a plate, the screw may have a head with a diameter that exceeds the diameter of the helix, or a conical washer may be used which allows for angulation of the head in the plate, or the head may include external threads that mate with internal threads in the plate. In an alternative embodiment, the head comprises a rivet or clamp, which can be fixed to a boss formed at the top of the helical structure. This version of the anchor can be driven into bone using matching Male-Female head.
Moreover, in accordance with an aspect of the invention, the structure is made by forming a screw type blank having an externally threaded member which extends from a cylindrical head having an internal torque receiving recess, preferably a hexagon. The blank is subsequently drilled internally to form an open helical structure attached to the solid head. The material removed is tapered along the long axis decreasing in the direction of the top of the helical structure where the apex of the cone is at the proximal position of the helix. This places more material at the driver level where the helix joins the head and takes the driving torque. The conical opening may still include a through hole for cannulation. In addition, it has been found to be an advantage for the helix to include a taper from the insertion end toward the head in the direction of the longitudinal length of the filament. This provides for significantly higher test results in the pull-out strength.
SUMMARY OF THE INVENTION
The anchor in accordance with the invention comprises an open helical structure which is a constant or varied-diameter, elongate member, fiber, filament or thread comprised of a relatively rigid, biocompatible material such as a wire having a diameter which may vary optimally from about 0.2 millimeters to about 5.0 millimeters. The length of the anchor will depend upon the particular application, but will range generally from about 3.0 millimeters to about 75.0 millimeters with the upper ranges being useful for buttressing techniques. The outer diameter of the helix will also vary in accordance with the application, but it will range generally from about 1.5 millimeters to about 15.0 millimeters. A suitable rate of slope for the helix is from about 0.5 to about 10 turns per centimeter. The aspect ratio of the helix, which as used herein means the ratio of the helix outer diameter to the fiber diameter, is an important ratio in order to achieve the proper stiffness to enable insertion and to firmly seat in the bone; a suitable range is 3.5 to 4.5.
Advantageously, the anchor of the present invention involves relatively simple, cost-effective manufacturing processes. The present anchor is also less intimidating to doctors and patients than prior art devices and can be used with simple, straight-forward instrumentation. Finally, since the device is relatively noninvasive, several can advantageously be used together in instances where more than one prior art device could not be used. It is preferred, but not necessary, that the helical structure has a constant circular diameter and a constant slope (meaning the rate of turn per unit of longitudinal length). Likewise in another embodiment, it is preferred that the filament that comprises the helical structure does not have a constant circular cross-section, but rather has a taper which increases from the insertion tip to the head, and which can have a cross-section other than a circle, such as a modified triangle or a thread shape. The increase is an increase of up to about 100% of the initial diameter, with a preferred range being in the 10–50%, and a more preferred range being in the range of 15 to 30% with the optimal taper being bout 25%.
For its connective applications, the anchor includes an attachment head at one end which is suitable for securing the tissue or suture which is to be held. For example, in the case of a filamentary anchor, the anchor may have a hook, crossbar or eyelet. For applications in which the anchor secures material such as cartilage or a buttressing plate, the head may have a surface which is designed to distribute the load evenly over the material.
In a second embodiment, the anchor will have a modular head. For example, the helical anchoring portion may terminate at the superficial end in a post that will accommodate one of several head options. These head options may include a button, clamp, clip, snap, or rivet. At the other end, the anchor includes a cutting or self-tapping point. The head may be a solid cylindrical construction which is integral to and the same diameter as the helical structure in order that the head will countersink into the fastening surface. In other words, the anchor does not have a smaller diameter area or necked area which fastens the head to the helix, likewise, the head does not extend beyond the outer diameter of the helix like an upholstery button that would be apt to wind or unwind during implantation. An outer cannula may be needed to support the helix and retain rigidity as it is driven into the bone. For example, it is envisioned that the helix, when used as anchor, may be packaged in a translucent medical grade plastic cannula that allows support to the helix and visualization as it is being driven in. This is a disposable piece that is discarded after implantation of the helix.
In accordance with another embodiment of the invention, a buttressing system is provided which comprises a plate having at least two through bores which are each engaged by an open-helix anchor.
In accordance with a method of the present invention, an anchoring site is surgically accessed, the helical anchor is screwed into the anchoring site, and connective tissue is secured to the attachment head of the anchor.
In accordance with another method of the invention, a bone is buttressed by surgically accessing an implant site, aligning a plate having at least one aperture over the site, and securing the plate to the implant site by inserting an open-helix anchor through the aperture and into the implant site to anchor the plate with respect to the implant site.
In accordance with another embodiment of the invention, a method of making the anchor comprises making an externally threaded blank of a relatively constant outer diameter, and consequently reaming the blank to form an open helical structure. Preferably, the blank is reamed so as to cause a conical removal of material at the apex of the cone, proximate the join of the head and the helix. This places more material at the driver level and tapers the threads. This strengthens the helix at the driver for transmission of torque. The resulting wedge shape to the threads increases the anchoring into the bone.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of the anchor device showing the attachment head in side elevation;
FIG. 2 is a top view taken of FIG. 1 ;
FIG. 3 is an elevational view similar to FIG. 1 , but showing the anchor rotated 90° to the right so that the attachment head is seen in an end view;
FIG. 4 illustrates the pilot hole in the bone prior to insertion of the anchor;
FIG. 5 illustrates an anchor in place in the cancellous portion of the bone with the attachment head projecting above the surface of the bone in order to allow attachment of the soft tissue to the anchor;
FIGS. 6 and 7 illustrate the tool which may be used for inserting the anchor;
FIG. 8 is an elevational assembly of a second embodiment of the anchor having a modular head;
FIG. 9 is a top view of the head illustrating the slot in phantom,
FIG. 10 is a side view of the second embodiment of the anchor device in accordance with the invention;
FIG. 11 is an elevation view of the embodiment shown in FIG. 8 rotated 90°;
FIG. 12 is a bottom end view of the helix portion of the embodiment shown in FIG. 10 ;
FIG. 13 is an elevational view of a third alternative embodiment of the invention;
FIG. 14 is a top view of the embodiment shown in FIG. 13 and;
FIG. 15 is an elevational view of a fourth embodiment of the present invention;
FIG. 16 is a top view of the embodiment shown in FIG. 15 ;
FIG. 17 is an elevational view of a fifth embodiment of the present invention;
FIG. 18 is a top view of the embodiment of the invention shown in FIG. 17 ; and
FIG. 19 illustrates an uncoiled filament which may be wound in a manner to comprise the embodiment shown in FIGS. 17–18 .
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention, FIGS. 1–3 illustrates the anchoring device in accordance with the invention enlarged to show the invention in detail generally at 10 . The anchoring device 10 comprises an open helix 12 having a pointed insertion tip 14 at one end and an attachment head 15 at the other end.
Preferably, the anchoring device is comprised of a rigid, biocompatible material having a high-yield strength such as stainless steel or titanium. The device can also be made from a biodegradable material such as polyglycolic acid (“PGA”), polylactic acid (“PLA”), polydiaxone hydroxy apatite (“PDA”), and the like. For example, the device 10 may be made from surgical-grade titanium or stainless steel wire having a wire diameter ranging from about 0.4 millimeters to about 3.0 millimeters, and more specifically from about 0.5 millimeters to about 2.0 millimeters, and most specifically from about 1.0 millimeters to about 2.0 millimeters. Optionally, the helix diameter may be of variable cross-section ranging from a smaller-diameter wire at the insertion tip to a larger-diameter wire near the attachment head 15 .
The “slope” of the helix is used herein to mean the number of turns (i.e., one 360° rotation) per unit length and varies from about 0.5 turn per centimeter to about 10 turns per centimeter, and more specifically from about 0.5 turn to about 4 turns per centimeter, and most specifically from about 1 to about 2 turns per centimeter. The anchor generally comprises a length of helix sufficient to achieve from 0.75 to 4 complete 360° revolutions, or more specifically from about 1 to about 3 revolutions. Accordingly, the length of the anchor for most general fastening or anchoring applications is from about 3 to about 18 millimeters, and more specifically from about 4 to about 15 millimeters, and most specifically from about 8 to about 15 millimeters. For plating or buttressing applications, the length of the anchor will generally range from about 5 to about 75 millimeters, preferably from about 5 to about 40 millimeters and most preferably from about 10 to about 20 millimeters.
The overall outer diameter of the open helix portion 12 of the anchoring device 10 , ranges from about 1.5 to about 11 millimeters, and more specifically from about 3 to about 9 millimeters, and most specifically from about 5 to about 7 millimeters. The wire is generally circular in cross-section, although it is envisioned that it may be angular such as diamond-shaped or rhombohedral. In accordance with an additional embodiment of the invention, the anchor has an integral head which has the same outer diameter as the helical structure. And further, the elongate member which forms the helix can have a generally triangular cross-section so that the overall impression is of a cutting thread with no core. It should however be noted that the open structure does not act like a screw in its performance, and in particular in the method of failure. In the embodiment shown in FIGS. 17–19 , the filament has a taper in the diameter which decreases toward the insertion end. While this is shown as a circular cross-section, it can have the taper in alternative shapes, such a the triangular or thread-like shape. The taper represents a substantial improvement in the strength required.
It is important that the anchor have an aspect ratio of from about 3 to about 5, preferably from 3.5 to 4.5, and most preferably around 4. As used herein, aspect ratio means the ratio of the helix outer diameter to the wire diameter. If the ratio is too large, the device is too rigid, whereas if the ratio is too small, the device is overly flexible.
The attachment head 15 of the anchoring device 10 may vary according to the specific application. For example, it may be desirable to include a broader compression area for direct attachment of connective or soft tissue to bone, as compared to suture techniques involving suturing or wiring the soft tissue in place with respect to the anchoring device. Examples of attachment heads suitable for suturing or wiring connective tissue include crossbars, hooks and eyelets.
FIG. 1 illustrates an attachment head 15 having a crossbar 17 which arches slightly above the last helical turn and is attached such as by spot welding 18 at the terminal end. It may be further preferable to include an opening 19 or cannulation in the crossbar to allow for cannulated surgical techniques (i.e., placement of the anchor over a positioned wire which may be subsequently removed). The opening may range in size from 0.5 millimeters to 1.5 millimeters depending on the application.
The device and method of the invention are illustrated in FIGS. 3–5 . In particular, FIG. 4 illustrates a section of bone generally at 20 having a cortex 22 and a cancellous portion 24 . A pilot hole 25 has been drilled in the cortex 22 in order to ease insertion of the anchoring device 10 . A countersink hole 26 through the cortex is also illustrated.
FIG. 5 illustrates the anchoring device 10 as it has been partially implanted through the pilot hole 25 into the cancellous portion of the bone. In some instances where the cortex is particularly thin, a pilot hole may be unnecessary. The soft tissue is attached to the anchoring device when the device is in position such as by suturing or wiring to the attachment head 15 of the anchoring device 10 .
FIGS. 6 and 7 illustrate an instrument which can be used for the implantation of the anchor in accordance with the present invention.
Specifically, the instrument includes a central shaft 30 having a T-shaped handle 32 designed to allow the surgeon to easily grasp the handle 32 and rotate the shaft 30 to screw the anchor 10 into the bone through the optional pilot hole. The placement guide 34 includes a bottom surface 36 which can rest against the cortical surface where the anchor 10 is to be implanted. The guide 34 further includes an internal opening 38 having a diameter sufficient to receive the top portion of the anchor 10 . The guide 34 further includes a bore 40 which provides a bearing surface for the shaft 30 . At its lower end, the shaft 30 includes a head 42 having an internal slot 44 which receives the crossbar of the anchor 10 to enable the surgeon to apply torque to the anchor. The head 42 has an external diameter which cooperates with the internal diameter of the anchor 10 . Optionally, the shaft 30 may also include a longitudinal, internal opening to receive a guide wire to allow for further cannulated surgical techniques.
During use of the anchor of the present invention, the attachment location is approached with standard surgical exposure. A pilot hole is drilled through the near cortex only and a drill sleeve is used to protect surrounding soft tissues. The hole consists of removal of cortex such that the head of the helix may be countersunk below the cortical surface. A tap, or a helical tool is fabricated from a material with a high modulus of elasticity, and that cuts the threads for the helix. The anchoring device 10 is inserted with an insertion tool such that the attachment head 15 is left out of the bone. The angle of insertion may be perpendicular to the bone surface or at a 45° angle. A suture may be passed under the exposed crossbar 17 of the attachment head 15 once or twice, depending on the surgeon's choice. The attachment tool is then used to countersink the attachment head 15 below bone level. The ligament or tendon is then sutured into place with a preferred suturing method such as Bunnell, whip, or modified Kessler. The wound is subsequently closed and the procedure is completed in standard fashion, or the head of the anchor may be used to attach the tissues without the use of structure.
FIGS. 8 through 12 show a second embodiment of the anchor 80 having a modular head 82 attached to a helix 84 . The helix 84 engages the bone as shown in the earlier embodiments. This version rotates through 540° (1 full rotations) and terminates at one end in a three-sided point 86 . At the other end, the helix 84 is formed into a ring 88 to form a seat for the head 82 . The ring 88 may be a complete circle if it is welded together, or less than a circle, so long as it forms a good seat for the head 82 . Preferably the ring 88 is the same diameter as the helix and the head 82 has the same outer diameter as the ring in order to allow the head to be countersunk into a plate or bone.
Preferably both the head 82 and helix 84 are formed of implant-grade stainless steel (such as SS 22-13), or other biocompatible metals or polymers about 0.02 to 0.2 inch, and preferably from 0.05 to 0.1 inch from the top surface of the helix ring 88 . The head 82 also includes an internal hex opening 90 to receive an anchor driver. The head 82 also includes a transverse through slot 92 shown in phantom in FIG. 9 . The slot can be used to hold sutures in order to anchor tendons or ligaments. On the opposite side, the head 82 includes a necked area or stem 94 which is a constant diameter cylinder welded or otherwise adhered along the bottom edge to the ring 88 . This may be fabricated from a solid piece of material. FIGS. 13 and 14 show a third embodiment of the anchor 100 , having an integral head 102 which is formed as an integral continuation of the helical portion 104 of the anchor. The head 102 has a compound profile with a lower junction 103 between the helix and the head, a middle cylindrical body 105 , and an upper enlarged button 107 that may fasten a suture or overlap a plate. Again, the helix 104 has a pointed insertion tip 106 , and the elongate member which forms the helix may have a cutting surface formed by a triangular cross-section, or a buttress type thread. The head has a depth of from about 0.03 to about 0.25 inch, and includes a torque receiving recess, preferably an internal hexagon 110 which has a point to point measurement of about 0.15 to about 0.25 inch. Further, the head includes a through slot (or slots) 112 which can receive a suture. The head includes an internal through bore 114 for cannulated surgical techniques.
FIGS. 15 and 16 show a fourth embodiment of the invention in which the head 122 is a cylindrical member 123 that extends from the helical member 124 . The head 122 further includes an internal hexagonal torque driving recess 126 which may have a through bore 128 connection to the open upwardly tapering portion 130 of the helix 124 . Through slots 132 may receive a suture. The taper 130 of the helix 124 results in a wedge shaped area 134 of the helix which is self-reinforcing for driving the helix into the bone. The blank is subsequently reamed using a conical auger, or a hot wire technique to form the tapering open helical structure of the present invention.
FIGS. 17–19 represent a fifth embodiment of the helix 130 in accordance with the invention. The helix includes a cross bar 132 which has a bore 134 for cannulated techniques. The helix is made from a coiled filament 136 which can have a round cross-section or a thread-like cross section. The filament includes an insertion tip 138 and tapers along at least a part, and preferably all of its length by a slight amount, i.e. from 5 to 100% of the value of the diameter adjacent the insertion tip, and preferably from about 10 to about 50% of this value, and most preferably from about 15 to about 30% of this value.
EXAMPLE
Six samples of surgical-grade, stainless steel bone anchors in accordance with the invention were placed in a sample of artificial cancellous bone. Two samples each had a total longitudinal length of about 20 millimeters. The other four samples each had total lengths of about 13 millimeters. The other diameter of all samples was 5 millimeters and the wire diameter was 1.5 millimeters. Both long samples and two short samples had attachment heads which were crossbars and were attached by heliarc spot welding. The other short samples had crossbar attachment heads which were not welded.
Pullout tests were conducted using an MTS instrument. Straight, longitudinal pull was applied to the embedded anchors; this reproduced the least favorable condition for pullout characteristics. The results are shown in the table below. “Displacement” refers to bending of the crossbar in the longitudinal direction.
TABLE 1 PLASTIC DEFORMATION SHORT/NON-WELDED SHORT/WELDED LONG/WELDED Average 48 lbs. with 2 Average 52 lbs. with Average 58 lbs. with millimeters of 2.2 millimeters of 2.4 millimeters of displacement displacement displacement
All of the numbers represent desirable anchoring values.
While in accordance with the patent statutes the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.
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The invention relates to a tissue anchor which is an open helix of biocompatible material having a slope of from 0.5 to 10 turns per centimeter, a length from 3 to 75 millimeters, a diameter of from 1.5 to 11 millimeters, and an aspect ratio of from about 3 to about 5 to 1. The anchor can have a head which is capable of securing or clamping tissue together, such as holding a suture to secure a ligament or tendon to bone. The anchor can also have a head which causes an inward, compressive loading for use in fastening bone to bone, orthopedic plates to bone, or cartilage to bone. The head may be an integral member and may include a self-reinforcing wedge which joins the helix to the head. Further, the elongate member, or filament that forms the helix may have a tapering diameter along its length.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and apparatus for dispensing and, more particularly, but not by way of limitation, to a method and apparatus for dispensing food products and food product concentrates, such as pizza sauce, soft ice cream, mustard, ketchup, mayonnaise, soup, salad dressing, juice concentrates, and the like.
[0003] 2. Description of the Related Art
[0004] The viscosity of food products varies widely and ranges from relatively hard (e.g., soft ice creams) to semi-liquids (e.g., pizza sauce, ketchup, and mustard) to liquids (e.g., soups). Problems associated with viscous products or soups that contain solids arise because an employee or a customer typically manually dispenses such products. These problems relate to consistency, quality, cost, cleanliness, and the like.
[0005] For example, ketchup and mustard usually have separate dispensers that each consist of a container having a pump. Although employees do not directly dispense ketchup and mustard, an employee must fill the dispensers when they are empty. This results in direct employee contact with both the dispensers and the ketchup and mustard. Furthermore, if the dispensers are not routinely cleaned or are cleaned improperly, an unsanitary condition situation arises.
[0006] As another example, some food products, such as pizza sauce or soup, come in concentrate packages. An employee opens the concentrate package and empties the package into a large, typically open container. The employee then adds water and mixes the concentrate and water to form the final product. Then, as needed for final preparation or consumption, an employee or customer ladles the final product from the large open container. Thus, the final product can remain uncovered for long periods and employees or customers often contact the final product, both of which are unsanitary.
[0007] Manual dispensing of food products occurs because heretofore the cost for dispensers suitable to dispense such products has been prohibitive. Accordingly, a product dispenser and a method of dispensing food product are needed that permit self-contained dispensing of food products and food product concentrates, such as pizza sauce, soft ice cream, mustard, ketchup, mayonnaise, soup, salad dressing, and the like.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, a product dispenser includes a support housing, a disposable or non-disposable pump, a disposable or non-disposable product package connectable to the pump, a pump driver connectable to the pump, and a dispensing station.
[0009] The dispensing station may also include a platform secured to a support housing, a base residing on the platform over the pump driver and defining a pump slot that receives the pump therein, and a container supported by the base that receives the disposable product package therein. The disposable product package and the pump driver connect to the pump. The pump driver operates the pump to draw product from the disposable product package. When the disposable product package is empty, the disposable product package and the pump if disposable are removed from the dispensing station and disposed.
[0010] The disposable product package may include a bag and a fitting secured to the bag wherein the fitting snap fits into an inlet of the pump adapted to receive the fitting therein. A mixing chamber is connectable to an outlet of the pump, whereby the mixing chamber is disposable with the pump if disposable when the disposable product package is empty. The mixing chamber includes a diluent inlet that introduces diluent into the mixing chamber for combination with product delivered into the mixing chamber by the disposable pump. A product delivery device may be coupled to an outlet of the mixing chamber.
[0011] The pump driver may include a driving fork connectable to the pump and a driver unit coupled with the driving fork, whereby the driver unit operates the driving fork to facilitate the drawing of product by the pump from the disposable product package. The pump driver may further include a frame mountable to the dispensing station and adapted to link the driving fork with the driver unit.
[0012] The driver unit may include a motor coupled with the driving fork via a drive shaft engageable with the driving fork and a gearbox coupled with the drive shaft and with the motor for transferring the driving force of the motor to the drive shaft. The driver unit may further include a clutch unit mountable onto the drive shaft for interfacing the drive shaft with driving fork. The driving fork includes an interface that engages a piston of the pump to couple the driving fork with the pump and a drive slot that engages the drive shaft of the driver unit to couple the driving fork with the driver unit.
[0013] A method of dispensing product includes inserting a disposable pump into a dispensing station. A disposable product package is inserted into a dispensing station. The disposable product package is connected to the disposable pump. A pump driver is connected to the disposable pump. The disposable pump is operated via the pump driver to draw product from the disposable product package. The disposable product package and the disposable pump are removed from the dispensing station and disposed when the disposable product package is empty.
[0014] Another method of dispensing a product measures diluent flow and controls a disposable pump, based on the measured flow, to pump the product. The diluent and the product are mixed and dispensed. The method further includes shipping the product and the pump, coupling the product to the pump at a location where dispensing occurs, and installing the coupled product and pump in a dispenser. Conversely, the product and pump may be coupled during installation in the dispenser. Alternatively, the method further includes coupling the product and the pump, shipping the coupled product and pump to a location where dispensing occurs, and installing the coupled product and pump in a dispenser.
[0015] Still another method of dispensing a product includes shipping a disposable pump, shipping the product, coupling the product to the pump at a location where dispensing occurs, pumping the product in the pump, and dispensing the product. The method further includes installing the coupled product and pump in a dispenser or, conversely, coupling the product and pump during installation in the dispenser. Alternatively, the product and pump may be shipped together. The method still further includes mixing the product with a diluent and dispensing the mixture of the product and the diluent.
[0016] A further method of dispensing product includes coupling the product to a disposable pump, shipping the coupled product and pump to a location where dispensing occurs, installing the coupled product and pump in a dispenser, pumping the product, and dispensing the product.
[0017] It is therefore an object of the present invention to provide a product dispenser that receives a disposable product package and a disposable pump therein.
[0018] It is another object of the present invention to provide a product dispenser that includes a pump therein and receives a disposable product package therein.
[0019] It is still another object of the present invention to provide a product dispenser that combines a product concentrate with a diluent during dispensing to form and end product thereof.
[0020] It is a further object of the present invention to provide a product dispenser suitable for connection with an end product delivery device.
[0021] Still other objects, features, and advantages of the present invention will become evident to those of ordinary skill in the art in light of the following. Also, it should be understood that the scope of this invention is intended to be broad, and any combination of any subset of the features, elements, or steps described herein is part of the intended scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is a perspective view including cut-away portions illustrating a product dispenser according to the preferred embodiment.
[0023] [0023]FIG. 2 is a side view illustrating a product package according to the preferred embodiment.
[0024] [0024]FIG. 3 is an exploded perspective view illustrating a pump driver according to the preferred embodiment.
[0025] [0025]FIG. 4 illustrates a driving fork of the pump driver. FIG. 4 a is a perspective view illustrating the driving fork. FIGS. 4 b and 4 c are cross-sectional views illustrating the driving fork.
[0026] [0026]FIG. 5 is an exploded perspective view illustrating the driving fork connectedly engaged with a pump plunger of a pump.
[0027] [0027]FIG. 6 illustrates a clutch unit of the pump driver. FIG. 6 a is a perspective view of the clutch unit. FIGS. 6 b - d are cross-sectional views of the clutch unit.
[0028] [0028]FIG. 7 illustrates methods of dispensing product. FIG. 7 a is a flowchart of a dispense controlled according to a diluent flow rate. FIGS. 7 b - c are flowcharts of a dispense preceded by the delivery and installation of a pump and a product package.
[0029] [0029]FIG. 8 is a perspective view illustrating a product dispenser according to an alternative embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. It is further to be understood that the figures are not necessarily to scale, and some features may be exaggerated to show details of particular components or steps.
[0031] As illustrated in FIG. 1, a product dispenser 300 includes a support housing 301 and a cover 302 mounted removably atop the support housing 301 . The support housing 301 supports and houses the components of the product dispenser 300 . Similarly, the cover 302 surrounds and thus protects the components of the product dispenser 300 .
[0032] The support housing 301 includes at least one dispensing station 303 secured to the support housing 301 at an upper portion thereof and a pump driver 100 supported by the dispensing station 303 . The dispensing station 303 includes a platform 304 , a base 305 residing on the platform 303 over the pump driver 100 , and a container 306 supported by the base 305 . This preferred embodiment discloses the product dispenser 300 including four dispensing stations 303 and four pump drivers 100 to illustrate the dispensing of multiple products, such as ketchup, mustard, mayonnaise, salad dressing, and the like. Nevertheless, only one dispensing station 303 and one pump driver 100 may be used.
[0033] As illustrated in FIGS. 1 - 6 , the pump driver 100 drives a pump 220 to facilitate the dispensing of product from a product package 308 . The pump 220 includes a piston 225 as in FIG. 5 engageable with the pump driver 100 to effect the drawing of product from the product package 308 . The dispensing station 303 provides a housing that holds the pump 220 and further permits the attachment of the pump 220 to the pump driver 100 via the piston 225 . Particularly, the base 305 includes a pump slot 309 for receiving the pump 220 therein. The pump slot 309 includes tabs 310 that engage flanges 311 on the pump 220 to aid in holding the pump therein.
[0034] The pump 220 includes an inlet 221 suitable for connection with the product package 308 and an outlet 222 suitable for connection with a mixing chamber 223 . The mixing chamber 223 in turn connects to a dispensing outlet 224 via a tube 227 . Although this preferred embodiment discloses a dispensing outlet 224 , the mixing chamber 223 may connect to any other suitable end product delivery device, such as a pizza sauce spreader and the like. The mixing chamber 223 includes a diluent inlet 228 connected to a diluent source that delivers a diluent (e.g., water) into the mixing chamber 223 . In this preferred embodiment, the mixing chamber 223 includes a mixing device suitable to facilitate the combining of the product and diluent. Consequently, the pump 220 delivers product, typically in concentrate form, into the mixing chamber 223 , and the diluent source delivers diluent into the mixing chamber 223 via the diluent inlet 228 , resulting in the product and diluent combining in the mixing chamber to form an end product dispensed from the dispensing outlet 224 . Although a mixing chamber 223 has been disclosed, those of ordinary skill in the art will recognize that the pump 220 may directly connect to the dispensing outlet 224 when the product does not require a diluent or when mixing before dispensing is not required.
[0035] To ensure desired mixed concentrations of product and diluent, a suitable flow control device may be provided between the diluent source and the diluent inlet 228 , and the pump driver 100 could be controlled to operate the pump 220 at a preset rate. Alternatively, a suitable metering device could be provided between the diluent source and the diluent inlet 228 . The metering device provides metered amounts of diluent and further measures diluent flow to produce a signal thereof, which is used to control the pump driver 100 and drive the pump 220 such that the pump 220 delivers a desired amount of product for combination with diluent. An example of a suitable metering device is disclosed in U.S. patent application Ser. No. 09/245,549, the disclosure of which is herein incorporated by reference.
[0036] The pump 220 in this preferred embodiment is a reciprocating piston type pump commonly associated with product dispensing. Although this preferred embodiment discloses a reciprocating piston type pump, any suitable alternative, such as progressive cavity pump, may be used.
[0037] The product package 308 includes a bag 312 coupled with a fitting 313 whereby the fitting inserts into the inlet 221 of the pump 220 . The fitting 313 includes an inlet 314 , a base 315 , and an outlet 316 . The base 315 engages the bag 312 and is permanently secured thereto using any suitable means such as a heat or sonic weld or suitable adhesive. The outlet 316 snap fits into the inlet 221 of the pump 220 to facilitate the delivery of product thereto. In this preferred embodiment, the bag 312 is constructed from flexible plastic material; however, other materials, such as, without limitation, plastic (e.g. PET) may also be used. Also, the pump may be adapted to receive product from any type of source, and the snap fit described herein is exemplary only.
[0038] The dispensing station 303 provides a housing that holds the product package 308 and further permits the attachment of the product package 308 to the pump 220 . Particularly, the container 306 includes an opening 317 that receives the product package 308 therethrough to permit placement of the bag 312 within the container 306 such that the fitting 313 resides over the pump slot 309 of the base 305 . Consequently, with the insertion of a pump 220 into the pump slot 309 , the outlet 316 snap fits into the inlet 221 of the pump 220 to facilitate the delivery of product thereto. The fitting 313 is secured to the bag 312 in a position permitting easy location of the fitting 313 over the pump slot 309 upon placement of the product package 308 into the container 306 . Although this preferred embodiment discloses a separate pump 220 and product package 308 , the dispensing station 303 may be adapted to receive an integral pump 220 and a product package 308 shipped together as a single unit.
[0039] The pump driver 100 , particularly illustrated in FIGS. 1 and 3- 6 , includes a driving fork 110 connectedly engaged with the pump 220 for providing a requisite motion to drive the pump 220 . Moreover, the pump driver 100 includes a driver unit 150 cooperatively linked with the driving fork 110 , whereby the driver unit 150 controls the rate by which the driving fork 110 moves and, thus, the rate by which product is pumped from the product package 308 . The driver unit 150 includes a standard motor 157 and a drive shaft 154 coupled to the motor 157 via a gearbox 152 . The gearbox 152 transfers the driving force of the motor 157 to the drive shaft 154 as well as permits variable control in the direction and speed of the drive shaft 154 . The gearbox 152 mounts onto the platform 304 of the dispensing station 303 to locate the drive shaft under the base 305 , while the motor 157 mounts underneath the platform 304 . Although this preferred embodiment discloses the driver unit 150 as including a gearbox 152 and a drive shaft 154 , the motor 157 could connect directly to the driving fork 110 .
[0040] In this preferred embodiment, the driver unit 150 includes a clutch unit 159 that facilitates attachment of the drive shaft 154 to the driving fork 110 . Nevertheless, the clutch unit 159 is not necessary as the requisite attachment mechanism could be incorporated directly onto the drive shaft 154 .
[0041] The preferred pump driver 100 further includes a frame 130 mountable to platform 304 of the dispensing station 303 for linking the driving fork 110 and the driver unit 150 in cooperative engagement. The frame 130 includes alignment bearings 132 engagedly coupled with the drive shaft 154 to ensure desirable operation of the driver unit 150 . The frame 130 further includes a locking subassembly 135 for securing the driving fork 110 with the frame 130 .
[0042] The driving fork 110 as illustrated in FIG. 4 c includes a body 115 , preferably constructed as a single piece. Moreover, the driving fork 110 is preferably divided into two portions, a head portion 11 a for engagement with the pump 220 and a lever portion 111 b extending outwardly from the head portion 111 a . The lever portion 111 b includes a lever arm 115 a preferably spanning the length of the lever portion 111 b for imparting motion to the head portion 111 a . The lever portion 111 b may include fork coupling elements 118 opposite the head portion 111 a and extending outwardly from the lever arm 115 a . As illustrated in FIG. 3, the fork coupling elements 118 are hingedly engaged with the frame 135 via corresponding locking notches 135 a provided by the locking subassembly 135 .
[0043] The head portion 111 a includes an interface 112 for contactedly engaging the piston 225 to thus drive the pump 220 . Specifically, in this preferred embodiment, the interface 112 defines a receiving slot 113 for engagement with corresponding piston ears 226 extending outwardly from the piston 225 . As illustrated in FIG. 5, the piston ears 226 slideably engage the receiving slot 113 so that the piston 225 is coupled with the pump interface 112 .
[0044] The head portion 111 a includes a drive slot 117 contactedly engaged by the clutch unit 159 . In operation, the clutch unit 159 traverses the drive slot 117 , thereby furnishing a desired motion to the driving fork 110 and, ultimately, to drive the pump 220 . The drive slot 117 in this preferred embodiment is substantially elliptical in shape to facilitate an up and down motion of the driving fork 110 and the piston 225 , as indicated in FIG. 3 by directional arrow 119 . Nevertheless, other suitable shapes for the drive slot 117 may be used that are suitable to supply a correspondingly desired motion thereof.
[0045] Furthermore, as illustrated in FIG. 4 b , a releasable member 116 forms the drive slot 117 and secures to the body 115 to the body 115 using any suitable means. Accordingly, the releasable member 116 facilitates ease of exchange with other releasable members having clutch unit slots of different configurations that supply correspondingly different motions to the driving fork 110 and the piston pump driver 220 . It should be added that other embodiments contemplate the drive slot 117 as defined by the body 115 .
[0046] As indicated by directional arrow 155 in FIG. 3, the driver unit 150 of the pump driver 100 preferably supplies a rotary motion so that the driving fork 110 may assume an up and down motion to drive the pump 220 . However other suitable motive directions of the driver unit 150 may be used for driving the pump 220 .
[0047] The clutch unit 159 interfaces the drive shaft 154 and the driving fork 110 . In particular, FIG. 1 illustrates the clutch unit 159 disposed on the drive shaft 154 for converting the motion of the drive shaft 154 to the requisite motion for operating the driving fork 110 and the pump 220 . Thus, as the clutch unit 159 rotates cooperatively with the drive shaft 154 , it preferably slides about the drive slot 117 , thereby establishing a desired up and down motion for the driving fork 110 and, ultimately, for the piston 225 of the pump 220 .
[0048] As illustrated in FIG. 6, the clutch unit 159 in this preferred embodiment is a one-way clutch. In FIG. 6 a , the clutch unit 159 includes a cam 161 , a spring 162 extending outwardly from the cam 161 , and a knob 160 extending outwardly from the cam 161 opposite the spring 162 , whereby the cam 161 , the spring 162 , and the knob 160 are preferably formed as one piece. The clutch unit 159 further includes a clutch unit bore 165 extending from the spring 162 through the cam 161 for securedly receiving the drive shaft 154 .
[0049] In operation, the motor 157 via the gearbox 152 propels the drive shaft 154 in the direction indicated by directional arrow 155 in FIG. 3. The drive shaft 154 in turn propels the cam 161 and the spring 162 . The cam 161 and the spring 162 rotate cooperatively with the drive shaft 154 , thereby allowing the knob 160 to slide about the drive slot 117 so as to ultimately drive the pump 220 . In effect, the knob 160 acts as a lever and is positioned on the cam 161 so that the shape of the cam 161 provides a sufficient lever arm for the knob 160 , as shown in FIG. 6 b . Accordingly, the pump driver 100 drives the pump 220 in the following manner. The drive shaft 154 turns the clutch unit 159 disposed thereon so that the knob 160 of the clutch unit 159 engages the drive slot 117 , thereby allowing for the interface 112 of the driving fork 110 to drive the pump 220 .
[0050] The driver unit 150 includes the clutch unit 159 to facilitate easier engagement of the drive shaft 154 with the drive slot 117 . Specifically, to link the drive shaft 154 with the drive slot 117 via the clutch unit 159 , the motor 157 may be controlled to implement a reverse rotational motion, as indicated for example in FIG. 3 by directional arrow 156 . When the drive shaft 154 rotates in reverse, the clutch unit 159 no longer rotates cooperatively with the drive shaft 154 but instead floats substantially freely about the turning drive shaft 154 . While the clutch unit 159 floats substantially freely about the drive shaft 154 , the knob 160 thus slides against the driver slot 117 with less force than required for drive shaft 154 to operatively drive the pump 220 . By sliding with less force, the knob 160 moves the driving fork 110 at a rate sufficient for readily coupling with the piston 225 of the pump 220 . In particular, it is relatively easy to engage the piston ears 226 of the pump 220 with the receiving slot 113 of the driving fork 110 due to the substantially free floating of the clutch unit 159 . Once the driving fork 110 is connectedly engaged with the piston 225 of the pump 220 , the motor 157 switches from reverse rotational motion to a rotational motion suitable for operating the pump 220 .
[0051] To facilitate the dispensing of product as illustrated in FIGS. 7 a - c , a product package 308 and a pump 220 are shipped either together or separately to a location containing a product dispenser 300 . In some instances, the pump product package 308 and the pump 220 may be coupled together prior to shipping. The cover 302 is removed from the support housing 301 , the pump 220 is inserted into the pump slot 309 , and the pump 220 is connected to the pump driver 100 . The mixing chamber 223 , which is also typically disposable, is placed in the product dispenser 300 and connected to the dispensing outlet 224 via the tube 227 . It should be understood that the mixing chamber 223 may be integral with the pump 220 or connected prior to shipping or installation. Further, the diluent inlet 228 is connected to a diluent source using any suitable means, such as tubing. The product package 308 is placed within the container 306 such that the fitting 313 resides over the pump slot 309 , and the outlet 316 is snap fit into the inlet 221 of the pump 220 to facilitate the delivery of product thereto. Alternatively, the pump 220 and the product package 308 are loaded into the dispensing station 303 as an integral unit when the pump 220 and the product package 308 are coupled together either prior to shipping or prior to installation. The cover 302 is then returned onto the support housing 301 to place the product dispenser 300 in condition to dispense product.
[0052] Product dispenser 300 delivers product responsive to the activation of a user interface device, typically a switch, that connects the motor 157 to a power source, typically a regulated power supply receiving input power from a standard 115V/120V line or 230V/240V line. The user interface device may further facilitate activation of a flow control device associated with diluent delivery, typically a valve, flow controller, or suitable metering device as previously described. The activation of the motor 157 facilitates the actuation of the pump 220 via the pump driver 100 as previously described. The pump 220 draws product from the product package 308 and delivers the product from the dispensing outlet 224 . A dispense associated with a metering device involves the metering device measuring the flow of diluent and outputting a signal thereof. A controller, such as a microprocessor of other known control system, drives the pump driver 100 and thus the pump 220 at a speed determined by the output signal such that the pump 220 delivers a desired amount of product for mixture with diluent. Upon the deactivation of the user interface device, the product dispenser 300 ceases the delivery of product due to the corresponding deactivation of the motor 157 and flow control device.
[0053] After the emptying of a product package 308 , the cover 302 is again removed from the support housing 301 , and the outlet 316 of the fitting 313 is disconnected from the inlet 221 of the pump 220 . The product package 308 is then removed from within the container 306 . The mixing chamber 223 is disconnected from the dispensing outlet 224 , and the diluent inlet 228 is disconnected from the diluent source. The mixing chamber 223 is then removed from the product dispenser 300 . Conversely, the mixing chamber could be washable in place and thus remain within the product dispenser 300 . The pump 220 is disconnected from the pump driver 100 and removed from the pump slot 309 . Alternatively, the pump 220 and the product package 308 are removed together as an integral unit when the pump 220 and the product package 308 are coupled together either prior to shipping or prior to installation. The product dispenser is thus ready for reloading as described above. The removed product package 308 , pump 220 , and mixing chamber 223 are disposed, which makes the product dispenser 300 sanitary, as the product is not exposed to the environment.
[0054] Accordingly, when a product package 308 containing concentrated product is employed, the product dispenser 300 provides a significant cost saving in terms of product shipping and storage costs. Moreover, significant quality and cost advantages are achieved because the food product is consistently dispensed, as opposed to the inconsistencies in ratio and quantity that result from manual dispensing.
[0055] Although this preferred embodiment contemplates a disposable pump, those of ordinary skill in the art will recognize that the pump 220 could be a non-disposable pump mounted within the pump slot 309 of the dispensing station 303 and utilized with multiple disposable product packages 308 . In this instance, the pump 220 could be washable in place and thus remain within the dispensing station 303 .
[0056] As illustrated in FIG. 8, an alternative embodiment of a product dispenser 400 provides a configuration that uses a cartridge 200 , which may be a permanent or disposable container, to supply product to the product dispenser 400 . The product dispenser 400 is similar to the product dispenser 300 and like parts have been labeled with like numerals, except the base 401 of the dispensing station 402 includes rails 385 defining a slot 390 that receives the cartridge 200 therein. Similar to the product package 308 , the cartridge 200 includes a fitting suitable for insertion into the inlet 221 of the pump 220 . Consequently, after the loading of the product dispenser 400 with the cartridge 200 , the product dispenser 400 operates identically to the product dispenser 300 in the dispensing of product.
[0057] Although the present invention has been described in terms of the foregoing embodiment, such description has been for exemplary purposes only and, as will be apparent to those of ordinary skill in the art, many alternatives, equivalents, and variations of varying degrees will fall within the scope of the present invention. That scope, accordingly, is not to be limited in any respect by the foregoing description; rather, it is defined only by the claims that follow.
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A method and apparatus for dispensing a product includes a support housing, a disposable or non-disposable pump, a disposable product package connectable to the pump, a pump driver connectable to the pump, and a dispensing station on the support housing. The dispensing station supports the pump driver and is adapted to receive the pump and disposable product package. The disposable product package and the pump driver connect to the pump. The pump driver operates the pump to draw product from the disposable product package. When the disposable product package is empty, the disposable product package and the pump if disposable are removed from the dispensing station and disposed.
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This is a divisional of application Ser. No. 08/440,516 filed on Jun. 16, 1995 U.S. Pat. No. 5,836,020 which are described in this specification.
The invention disclosed and claimed herein deals with a series of devices for moving an invalid or handicapped person from a poolside into a pool, and back to the poolside, wherein the invalid or handicapped person may be responsible for the total movement without the aid of a second person except for one embodiment of the invention. The devices of this invention have a novel feature, which is that fact that they can be moved and controlled during that movement without the use of direct electrical power.
There is further disclosed in this invention, a novel valve for controlling the flow of air, water, or hydraulic fluid, respectively, for the powering of the devices of this invention.
More specifically, this invention deals with a series of non-electrically powered devices which allow independent movement into and out of a pool of water, which devices may or may not be under the control of the invalid or handicapped person, and further, the devices of this invention have an enhanced security for the invalid or handicapped person from falling, or slipping from the support of the device, or being immersed in the pool for a time longer than desired or for a depth that is not desired, or from being moved to dangerous heights above the poolside, in order to accommodate the movements of the devices, and which allow for the mounting of the device away from the edge of the pool, and which provides a barrier to accidental slippage into the pool. The device of this invention have a further security for the invalid or handicapped individual in that the novel chain stabilizer mechanism provided with the devices of this invention allow for the smooth, essentially horizontal movement of the chair from and to the pool.
Thus, in addition to the above, it is a further object of this invention to provide devices which can be operated by the person deriving the benefits of the device, without the intervention or help of a second party.
It is still another object of this invention to provide devices that have no electrical power directly associated with them in order to prevent accidental electrocution in and around a body of water.
It is finally an object of this invention to provide a series of devices that have low maintenance, will not provide potential problems with the environment and which will allow a handicapped or invalid person to utilize in relative safety because of loading of the support device well away from the water in the pool.
BACKGROUND OF THE INVENTION
A variety of lift devices are known in the prior art for moving invalid or handicapped person from one position to another. In fact, there are several devices disclosed in the prior art which have been found useful specifically for moving persons from the poolside to the pool and back again, or movement to and from a bathtub and the like.
Such devices suffer from flaws in operation, safety, or convenience and the inventor herein, familiar with such devices as a result of having worked in the field for several years, noted these flaws and devised a series of apparati which tend to overcome most, if not all, of such shortcomings.
One such device, and a device believed by the inventor herein as being the closet prior art device, can be found in U.S. Pat. No. 4,996,728, which issued Mar. 5, 1991 to John Nolan. The nolan device is hydraulically powered and is mounted near the pool edge. However, the Nolan device is comprised of a stabilized single post mounted on a solid substrate, and a hydraulic piston driven assembly which is rigidly mounted to the single post. The lifting chair, attached to the piston shaft has a capability of swinging in a limited arc, to bring the lift chair from the solid substrate to a position over the water, which then allows the piston to drive the lift chair in a downwardly motion. This device requires that the occupant must load and unload very near the edge of the pool, contributing to the advent of accidents.
Most significantly however is the fact that the device of Nolan does not have the movement of the lift chair within the immediate control of the occupant at all times and therefore, the occupant may be unable to stop or reverse it until the end of its travel.
The inventor herein also wishes to note for those skilled in the art that there exists a U.S. Pat. No. 5,383,238, in the name of the inventor herein, which issued on Jan. 24, 1995, in which there is shown a lift device that is electrically powered and which has an electromagnetic brake to control the movement of the lift chair.
THE INVENTION
The invention herein deals with a series of non-electrical powered devices comprising a first device which is an independent lift comprising two spaced apart, vertical posts, wherein each vertical post has a top end and a bottom end, and a front and a back. Each vertical post is capable of being secured by the bottom end to a solid substrate and each vertical post has a plate rigidly affixed near the bottom end. The bottom plate has a top surface and the bottom plate has a connector means detachedly fixed to the top surface.
There are two independent lifting arms and each lifting arm has a near end and a distal end, a midpoint, and a back surface. Each lifting arm is attached to a first rotatable shaft at its near end. Each first rotatable shaft has an outer end and an inner end, and is supported on each of its outer and inner ends by a bearing situated in a first bearing housing, wherein the shaft is supported by the respective bearing within each of the first bearing housings.
Each first bearing housing is fixedly attached to the top respectively, of each vertical post and each first bearing housing has fixedly mounted near its near end, a non-rotating sprocket, which is a rolling chain sprocket.
Each lifting arm is secured near the distal end to a second bearing housing and there is a lifting bar common to both lifting arms which is rotatably secured in each of the second bearing housings and is supported by the a bearing within each of the second bearing housings.
The lifting bar extends through the bearing housings to provide a support for a rotating sprocket rigidly affixed to the lifting bar near the end thereof, said sprocket being similar to the non-rotating sprocket, in that it has a rolling chain sprocket configuration.
The non-rotating sprocket and the rotating sprocket are connected by a non-rotating chain.
Each lifting arm has a rigid brace with a near end and a distal end fixedly attached at the near end to the back surface of the lifting arm at or near the midpoint of the lifting arm.
There are two, essentially identical hydraulic assemblies, having a fixed end and a shaft end, and the hydraulic assemblies have a housing, a movable piston therein and a piston shaft attached to the piston. Each such hydraulic assembly is mounted on the top surface of the bottom plate by the respective connector means and each piston shaft is pivotally attached to the distal end of the rigid brace on each of the respective lifting arms.
The lifting bar has a lifting chair rigidly attached to it by chair support shafts and the chair is provided with a control for the control of the pistons in the hydraulic assemblies.
Each vertical post has a lower bearing housing fixedly attached near the lower end of the vertical post and containing therein a bearing. The independent lift has a lower rotating bar common to the vertical posts and the lower rotating bar extends from one vertical post to the other vertical post and through the lower bearing housing and is supported by the bearings located therein.
There is a set of lower sprockets detachedly fixed to each end of the lower rotating bar and such that these sprockets are capable of being rotated simultaneously with the rotation of the lower rotating bar. Each of the lower sprockets is connected to a middle sprocket by a rotatable chain.
One of the vertical posts has attached on its back, a manifold to accommodate the power means for the lift which means powers the piston in each piston assembly.
It is contemplated within the scope of this invention that the chains and the respective drive mechanisms can be covered with covers to prevent accidents.
With regard to a second device of this invention there is provided an independent lift comprising a single vertical post, wherein the post has a top end and a bottom end and each vertical post is capable of being secured by the bottom end to a solid substrate.
There is an independent lifting arm, and the lifting arm has a near end and a distal end and the lifting arm is attached to a first rotatable shaft at its near end. The first rotatable shaft has an outer end and an inner end and is supported on each of its outer and inner ends by bearings situated in a first bearing housing, the shaft being supported by a bearing within the first bearing housing.
The first bearing housing is fixedly attached to the top of the vertical post and has mounted near its near end, a non-rotating sprocket which is a rolling chair sprocket.
The lifting arm is secured near the distal end to a second bearing housing and a lifting bar is rotatably secured in the second bearing housing and is supported by a bearing within the second bearing housing.
The lifting bar extends through the bearing housing to provide support for a rotating sprocket rigidly affixed to the lifting bar and the rotating sprocket is similar to the non-rotating sprocket in that it is essentially the same size and is a rolling chain sprocket.
The non-rotating sprocket and the rotating sprocket are connected by a non-rotating chain.
There is a first gear fixedly attached to the first rotatable shaft at the outer end, and a second gear aligned and meshing with the first gear, said second gear mounted on a shaft which is rigidly mounted on the vertical post. There is a drive shaft attached to the second gear and capable of turning simultaneously with the second gear. Although it is not shown, there can be used a housing to enclose the first and second gears in order to provide safe operation.
The lifting bar has a lifting chair rigidly attached to it by a chair support shaft.
There is yet a third device within this series, said device being an independent lift comprising a single vertical post wherein the post has a front, a back, a top end and bottom end and the vertical post is capable of being secured by the bottom end to a solid substrate.
The vertical post has a plate rigidly affixed to the bottom end and the plate has a top surface which has a connector means detachedly fixed to said top surface.
There is an independent lifting arm and the lifting arm has a midpoint, a near end, a distal end, and a back surface and the lifting arm is attached to a first rotatable shaft at the near end, wherein the first rotatable shaft has an outer end and an inner end and is supported on each of the outer and inner ends by a bearing situated in a first bearing housing whereby the shaft is supported by the respective bearing within the first bearing housing.
The first bearing housing is fixedly attached to the top of the vertical post and the first bearing housing has mounted near the near end, a non-rotating sprocket which is a rolling chain type of gear.
The lifting arm is secured near the distal end to a second bearing housing and there is a lifting bar rotatably secured in the second bearing housing and being supported by a bearing within the second bearing housing.
The lifting bar extends through the bearing housing to provide support for a rotating sprocket rigidly affixed to the lifting bar, this rotating sprocket being similar to the non-rotating sprocket in size and configuration, which is a rolling chain sprocket. The non-rotating sprocket and said rotating sprocket are connected by a non-rotating chain.
The lifting arm has a rigid brace with a near end and a distal end and the rigid brace is fixedly attached at the near end to the back surface of the lifting arm, and at or near the midpoint of the lifting arm.
There is a hydraulic assembly having a fixed end and a shaft end wherein the hydraulic assembly has a housing, a movable piston therein and a piston shaft attached to the piston, the hydraulic assembly being mounted on the top of the solid substrate and fastened thereto by the connector. The piston shaft is pivotally attached to the distal end of the rigid brace on the lifting arm.
The lifting bar has a lifting chair rigidly attached to it by a chair support shaft and the chair is provided with a control for the control of the piston in the hydraulic assembly.
The independent lift is provided with a means to power the piston. The vertical post has attached on the back surface, a manifold to accommodate the power means.
Finally, there is a fourth device of this inventive series which is an independent lift comprising a single vertical post wherein the post has a front, a back, a top end and a bottom end and the vertical post is capable of being secured by the bottom end to a solid substrate.
There is an independent lifting arm and the lifting arm has a near end and a distal end and the lifting arm is attached to a first rotatable shaft at the near end wherein the first rotatable shaft has an outer end and an inner end and is supported on each of the inner and outer ends by a bearing situated in a first bearing housing, wherein the shaft is supported by the respective bearing within the first bearing housing.
The first bearing housing is fixedly attached within a rack and pinion housing fixedly surmounting the vertical post and it has mounted near the near end, a non-rotating sprocket, which sprocket is of the rolling chain sprocket.
The lifting arm is secured near the distal end to a second bearing housing and the lifting bar is rotatably secured in the second bearing housing and the lifting bar is supported by the bearing therein.
The lifting bar extends through the bearing housing to provide support for a rotating sprocket rigidly affixed to the lifting bar, said rotating sprocket being similar to the non-rotating sprocket in that its is essentially the same size and type of sprocket which has a rolling chain sprocket configuration. The non-rotating sprocket and said rotating sprocket are connected by a non-rotating chain.
The lifting bar has a lifting chair rigidly attached thereto by a chair support shaft, the chair being provided with a control.
The first rotating shaft has mounted on the distal end a spur pinion gear in parallel axis alignment with a rack, one end of said rack having threadedly adapted thereto in linear alignment with said rack, a threaded, elongated bar having a distal end, said distal end of the elongated bar linearly extending through and outside the rack and pinion housing.
There is a piston and the piston has a center aperture and an outside perimeter wherein the piston is detachedly mounted on the elongated bar through said aperture and the piston is housed in a piston housing having an inside surface. The piston has one or more seals around its outside perimeter to seal the piston against the inside surface of the piston housing. The piston housing has two separable ends, each separable end having an outside perimeter and at least two rod openings near said outside perimeter, each said end being coupled to the piston housing by two or more elongated rods, each said elongated rod having threaded ends, said coupling being provided by threaded fasteners on each of the threaded ends, each said threaded fastener being compressed tightly against said separable ends to enclose the piston.
There is a means of powering the piston and a means of controlling the movement of the piston.
Yet another aspect of this invention is a new and novel valve device that is used to control the devices of this invention that are powered with hydraulic fluid, water, air, or other gasses.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a full front view of the first device of this invention, showing a lift chair with control, support, and drive mechanism, wherein the middle sprockets and lower sprockets are shown as being moved away from the vertical post and without pressure hoses, all for purposes of clarity.
FIG. 2 is a full front view of the first device of this invention showing pressure hoses useful on the device and the protective covers in place.
FIG. 3 is a full side view of the device of FIGS. 1 and 2, where there is shown in phantom the forward movement of the chair with occupant.
FIG. 4 is an enlarged sectional side view of the first bearing housing and mechanism associated therewith through line 300--300 of FIG. 2.
FIG. 5 is an enlarged sectional side view of the second bearing housing and mechanism associated therewith through line 400--400 of FIG. 2.
FIG. 6 is an enlarged cross sectional view of the lower bearing housing of FIG. 2, through the lines 900--900.
FIG. 7 is a full side view of a second device of this invention in which the device is powered by a hand crank.
FIG. 8 is a full front view of the device of FIG. 7 where there is shown in phantom the sideward motion of the chair into a pool.
FIG. 9 is an enlarged sectional side view of the first bearing housing of the second device of this invention and the mechanism associated therewith, through line 500--500 of FIG. 7.
FIG. 10 is an enlarged sectional side view of the second bearing housing of the second device of this invention and the mechanism associated therewith, through line 600--600 of FIG. 7.
FIG. 11 is a full side view of a third device of this invention in which the device is powered by a single piston assembly.
FIG. 12 is a full front view of the device of FIG. 11 wherein there is also shown the sideward movement of the chair in phantom.
FIG. 13 is a full side view of the fourth device of this invention.
FIG. 14 is a full front view of the device of FIG. 13 also showing in phantom the sideward movement of the chair in phantom.
FIG. 15 is a sectional side view of the first bearing housing and associated mechanism taken through a the line 700--700 of FIG. 13.
FIG. 16 is a sectional side view of the second bearing housing and associated mechanism taken through the line 800--800 of FIG. 13.
FIG. 17 is an enlarged side view of the piston and rack and pinion of FIG. 14 shown the relationship of the piston, rack and pinion and the first rotatable shaft.
FIG. 18 is an enlarged side view of the piston and rack of FIG. 17.
FIG. is a full side view of a novel control valve of this invention.
FIG. 20 is a full top view of the wall block of FIG. 19.
FIG. 21 is a full righ end view of the wall block of FIG. 20.
FIG. 22 is a full side view of the back of the control block of FIG. 19 showing the seals and the center core in phantom.
FIG. 23 is a full top view of a control block of FIG. 19 showing the side outlets, seals, and center core in phantom.
FIG. 24 is a full side view of the front of the control block of FIG. 19 showing the seals and center core in phantom.
FIG. 25 is a full end view of a control block of this invention from the right side, shown the center core and holes for fastening the block to the wall block in phantom.
FIG. 26 is a full top view of a valve stem of the control valve of FIG. 19.
FIG. 27 is a full end view of the stem cover of the control valve of FIG. 19, showing the fastening means and, the indentions and center apertures in phantom.
FIG. 28 is a full side view of the stem cover of the control valve of FIG. 19, showing the fastening means, the indentions,m and the center apertures, all in phantom.
DETAILED DESCRIPTION OF THE INVENTION
Now, with reference to FIG. 1, there is shown a first device of this invention, which is an mechanical independent lift 1, having two spaced apart, vertical posts 2 and 2', wherein each vertical post 2 and 2' has a top end 3, a bottom end 4, a front 5, and a back 6. Each of the vertical posts 2 and 2' is capable of being secured by the bottom end 4, to a solid substrate 7. Each of the vertical posts 2 and 2' has a plate 8 rigidly affixed to the bottom end 4 and the plate 8 has a top surface 9 which is surmounted with a fixedly attached connector means 10.
The independent lift 1 has two independent lifting arms 11 and 11'. Each of the lifting arms 11 and 11' have a near end 12 and a distal end 13, a midpoint 14, and a back surface 15. With reference to FIG. 4, each of the lifting arms 11 and 11' is attached to a first rotatable shaft 16 at its near end 12 (lifting arm 11 shown only). The first rotatable shaft 16 has an outer end 17 and an inner end 18. The rotatable shaft 16 is supported on its outer end 17 and its inner end 18 by a bearing 19 which is situated in first bearing housing 20. The shaft 16 is supported by the bearing 19 within the first bearing housings 20 and 20'.
Each first bearing housing 20 and 20' has a near end 21 and 21' and a distal end 22 and 22', and is fixedly attached to the top respectively, of each vertical post 2 and 2'. In some instances, this connection may have to have support brackets 23 to help stabilize the housings 20 and 20'.
Each of the bearing housings 20 and 20' has fixedly mounted near their near ends 21 and 21' a non-rotating sprocket 24. This sprocket 24 is a roller chain type of sprocket.
With regard to FIG. 5, each of the lifting arms 11 and 11' are secured respectively near their distal end 13 to a second bearing housing 25 and 25'.
There is a lifting bar 26, common to both lifting arms 11 and 11'. The lifting bar 26 is rotatably secured in each of the second bearing housings 25 and 25' and the lifting bar 26 is supported by the bearings 27 and 27' within the second bearing housings 25 and 25'.
The lifting bar 26 extends through the second bearing housing 25 and 25' to provide a support 28 for a rotating sprocket 29, which is rigidly affixed to the lifting bar 26 at the support 28. The non-rotating sprocket 24 and the rotating sprocket 29 are connected by a non-rotating chain 30.
With reference to FIG. 3, each of the lifting arms 11 and 11' has a rigid brace 31 with a near end 32 and a distal end 33, fixedly attached at the near end 32, to the back surface 15 of the of the lifting arms 11 and 11', at or near its midpoint 14.
There are two essentially identical hydraulic assemblies 34 and 34' having a housing 35, a moveable piston 36 (shown in phantom in the left hydraulic assembly), and a piston shaft 37 (in phantom inside the hydraulic housing) attached to the piston 36. Each hydraulic assembly 34 and 34' are mounted on the top surface 9 of the bottom plate 8 by the connector means 10. Each piston shaft 37 is pivotally attached to the distal end 33 of the rigid brace 31 on each of the respective lifting arms 11 and 11'.
The lifting bar 26 has a lifting chair 38 rigidly attached to it by chair support shafts 39. The lifting chair 38 is provided with a control 40 for the control of the pistons 36 in the hydraulic assemblies 34 and 34'.
The independent lift 1 has a rotating bar 41 common to the vertical posts 2 and 2', which extends through the vertical posts 2 and 2' to provide a support means 42 for two lower rotating sprockets 42 and 42'. The rotating bar 41 is attached to the vertical posts 2 and 2' near the bottom end 4 of each respective vertical post 2 and 2'. The rotating bar 41 is supported at each of its ends 44 and 44' by bearings 45 and 45', (not shown) which are located in third bearing housings 46 and 46', which are shown in enlarge detail in FIG. 6. There is a rotating chain 48 connecting the lower rotating sprocket 42 and the middle rotating sprocket 29, and a rotating chain 48' connecting the lower rotating sprockets 42' and the middle rotating sprocket 29' such that when one set of sprockets moves, the second set of sprockets moves simultaneously. This configuration allows for the simultaneous movement of the lifting arms 11 and 11' so that there is no twist or torque associated with the lifting bar 26. Also, this configuration lends a braking effect to the device such that the lifting chair 38 always moves in a smooth arc, with the lifting chair 38 always at the lowest possible level during the swing of the lifting chair 38 through the moving arc.
One of the vertical posts 2, for example, has attached on its back 6, a manifold assembly 43 for the independent lift 1. The independent lift 1 is adapted by means to power the pistons 36 in the piston assemblies 34 and 34'.
As discussed above, the sprockets 24 and 29 are connected together by chain 30. When the hydraulic assemblies 34 and 34' are activated by the control 40, the pistons 36 move within the housings (cylinders), which in turn moves the shafts 37, which in turn moves the lifting arms 11 and 11'. Because the shafts 37 are pivotally attached to the rigid braces 31, the lifting arms 11 and 11' move simultaneously with the movement of the piston shafts 37 to raise or lower the lifting arms 11 and 11'. When the lifting arms 11 and 11' are moved, the lifting bar 26 rotates because the weight in the lift chair allows the chair 38 to seek the lowest possible position because of the force of gravity. However, the sprocket 29 is rigidly attached to the lifting bar 26 and that sprocket turns when the lifting bar 26 turns. This could potentially create a swinging motion to the chair. Because the lower sprocket 24 is fixed, that is, it does not rotate, the chain 30 is held essentially motionless and the chair 38 is smoothly carried through the descending or ascending arc without swinging or moving rapidly through the arc. The movement of the lifting arms 11 and 11' turn the first rotating shafts 16 which in turn rotate the middle sprockets 29 and 29', which rotates the chains 48 and 48', which move simultaneously and rotate the lower rotating sprockets 42 and 42' which commonly drive the rotating bar 41. By this means, the movement of the chair 38 is smooth and because the lifting arms 11 and 11' operate simultaneously with the rotating lifting bar, the height of movement of the chair 38 from the ground level is not very high. On the other hand, the length of the lifting arms 11 and 11' allows one to move the chair lift 38 a goodly distance from the edge of the pool, mount the chair 38 in relative safety, and still have the flexibility to lower the chair lift 38 to a considerable depth in the pool as can be observed from FIG. 2.
FIG. 3 is a full side view of the first device of this invention showing in phantom, the forward movement of the chair and occupant into a pool. There is also shown in phantom therein the forward movement of the piston assembly and the lifting arm to accommodate the forward movement of the chair and occupant.
The devices of this invention are powered by hydraulics, water pressure or air/gas pressure. With regard to FIG. 2, there is showing one embodiment of the pressure hoses 49 of this invention in a typical hook up to the device 1.
As can be observed from FIG. 2, the inventor herein, for each of the devices described and claimed herein, contemplates the use of safety shields 47 and 47' over the moving chains 48 and 48', and the rotating sprockets 42, 42', 29 and 29'. FIG. 2 shows the extensive placement of the pressure hoses, the controls, and the manifolds that are required to power the devices of this invention, and such items have been essentially left off of the remainder of the Figures for the sake of clarity, it being understood that except for the second device of this invention, each such device will need the hoses, controls and manifolds similar to those shown in FIG. 2.
The chair lift 38 can be operated by the person in the chair 38 and this person has complete control over the movement of the chair 38. Finally, there are no electrical problems to worry about like when one uses an electrically powered unit. It should be noted by those skilled in the art that the chain and sprockets of this device can operate as a brake for the chair, as well as a means of moderating the rate of movement of the chair.
Turning now to FIGS. 7 and 8 and the second device of this invention, there is shown an independent lift 50. In contrast to the first device of this invention, this independent lift has a single vertical post 51, said post 51 having a top end 52 and a bottom end 53. The vertical post 51 is capable of being secured by the bottom end 53 to a solid substrate 55.
With respect to FIGS. 7 and 8, and in more detail in FIGS. 9 and 10, there is shown an independent lifting arm 56, said lifting arm 56 having a near end 57 and a distal end 58. The lifting arm 56 is attached to a first rotatable shaft 59 at the near end 57. The first rotatable shaft 59 has an outer end 60 and an inner end 61, the first rotatable shaft 59 being supported on each of its outer end 60 and inner end 61 by a bearing 62 situated in a first bearing housing 54, the first rotatable shaft 59 being supported by the bearing 62 within the first bearing housing 54. The first bearing housing 54 is fixedly attached to the top 52 of the vertical post 51. The first bearing housing 54 has mounted near it near end 63, a non-rotating sprocket 64. The lifting arm 56 is secured near its distal end 58 to a second bearing housing 65.
There is a lifting bar 66 rotatably secured in the second bearing housing 65, said lifting bar 66 being supported by a bearing 67 within the second bearing housing 65. The lifting bar 66 extends through the second bearing housing 65 to provide support 68 for a rotating sprocket 69 rigidly affixed to the lifting bar 66 by the support 68. The non-rotating sprocket 64 and the rotating sprocket 69 are connected by a non-moving chain 70.
There is a first gear 71 fixedly attached to the first rotatable shaft 59 at its outer end 60. A second gear 72 is aligned and meshes with the first gear 71, the second gear 72 being mounted on the vertical post 51.
There is also provided a drive shaft 73 attached to the second gear 72 which is capable of turning simultaneously with the second gear 72. A housing 74 shown in FIG. 8, but not shown in FIG. 7 for clarity, encloses the first gear 71 and the second gear 72.
The lifting bar 66 has a lifting chair 75 rigidly attached to it by a chair support shaft 76. The drive shaft 73 has attached to it some means of powering it and as shown in FIG. 7, there is a crank handle 77. However it is contemplated within the scope of this invention to equip the drive shaft 73 with other means of power, such as for example, adapting a water pump to the drive shaft 73.
The second device is a much simplified version of the first device and it can be observed that the same principle applies with regard to the non-rotating sprocket 64, the rotating sprocket 69 and the stationary chain 70. This device is intended to be economical in that it can be powered by a hand crank associated with a set of gears. This device allows for the safe mounting of the lift chair from a goodly distance away from the pool, yet allows for the person in the chair to be lowered a considerable distance into the pool. This device differs from the first device in that it requires that a person other than the person using the lift chair to operate the power means.
With regard to the third device of this invention, reference is made to FIGS. 11 and 12 wherein there is shown a device 78 which is a single post, piston driven device.
There is shown therein a single vertical post 79 and the post has a front 80, a back 81, a top end 82, and a bottom end 83. The vertical post 79 is capable of being secured by the bottom end 83 to a solid substrate 84.
There is shown an independent lifting arm 85 and the lifting arm 85 has a midpoint 86, a near end 87, a distal end 88, and a back surface 89. The lifting arm 85 is attached to a first rotatable shaft 90 at the near end 87 and the first rotatable shaft 90 has an outer end 91 and an inner end 92. The first rotatable shaft 90 is supported on each of its outer ends 91 and 92 by a bearing 93 which is situated in a first bearing housing 94. The first rotatable shaft 90 is supported by the bearing 93 within the first bearing housing 94.
The first bearing housing 94 is fixedly attached to the top end 82 of the vertical post 79 by welding or some other convenient means. The first bearing housing 94 has mounted near its near end 95, a non-rotating sprocket 96. The lifting arm 85 is secured near the distal end 88 to a second bearing housing 97.
There is a lifting bar 98 rotatably secured in the second bearing housing 97 and is supported by a bearing 98 within the second bearing housing 97.
The lifting bar 98 extends through the second bearing housing 98' to provide support 100 for a rotating sprocket 99 which is rigidly affixed to the lifting bar 98 by the support 100.
The non-rotating sprocket 101' and said rotating sprocket 99 are connected together by a non-rotating chain 101.
The lifting arm 85 has a rigid brace 102 with a near end 103 and a distal end 104 and the rigid brace 102 is fixedly attached at the near end 104 to the back surface 89 of the lifting arm 85 and at or near the midpoint 105 of the lifting arm 85.
There is a hydraulic assembly 106 having a fixed end 107 and a shaft end 108, said hydraulic assembly 106 has a housing 109, a movable piston 110 therein and a piston shaft 111 attached to the piston 110, said hydraulic assembly 106 is mounted on the top 112 of a plate 113, which is mounted on the top of the solid substrate 84, the piston shaft 111 is pivotally attached to the distal end 104 of the rigid brace 102 on the lifting arm 85.
The lifting bar 98 has a lifting chair 114 rigidly attached to it by a chair support shaft 115, said chair 114 being provided with a control 116 for the control of the piston 110 in the hydraulic assembly 106. The vertical post 79 has attached on the back surface 117, a manifold 118 for the independent lift 78. The independent lift 78 is adapted by means to power the piston 110 in each piston assembly 106, which power means is not shown in the Figures.
The detail of the rotating shafts, sprockets, and the like is analogous to that found in FIGS. 9 and 10.
With regard to the fourth device of this invention and with reference to FIGS. 13 and 14, there is shown a device 119 which comprises a vertical post 120 wherein the vertical 120 has a front 121, a back 122, a top end 123, and a bottom end 124. The vertical post 120 is capable of being secured by the bottom end 124 to a solid substrate 125. With reference to FIGS. 13, 14, and 15, there is an independent lifting arm 126 and the lifting arm 126 has a near end 127 and a distal end 128. The lifting arm 126 is attached to a first rotatable shaft 129 at its near end 127 and the first rotatable shaft 129 has an outer end 130 and an inner end 131. The first rotatable shaft 129 is supported on each of the inner end 131 and the outer end 130 by a bearing 132, the bearing 132 being situated in a first bearing housing 133, the first rotatable shaft 129 being supported by the bearing 132 within the first bearing housing 133. The first bearing housing 133 is fixedly attached within a rack and pinion housing 134 which fixedly surmounts the vertical post 120.
The lifting arm 126 is secured near the distal end 128 to a second bearing housing 135. A lifting bar 136 is rotatably secured in the second bearing housing 135 which has a bearing 137 located therein and the lifting bar 136 is supported by the bearing 137 therein.
The lifting bar 136 is rotatably secured in the second bearing housing 135 and the lifting bar 136 is supported by the bearing 137 located in the second bearing housing 135. The lifting bar 136 extends through the second bearing housing 135 to provide a support 138 for a rotating sprocket 139 rigidly affixed to the lifting bar 136 by the support 138. The non-rotating sprocket 140 and the rotating sprocket 139 are connected together by a non-rotating chain 141.
The lifting bar 136 has a lifting chair 142 rigidly attached thereto by a chair support shaft 143, the chair 142 being provided with a control 144.
The first rotating shaft 129 has mounted on the outer end 130, a spur pinion gear 145 in parallel axis alignment with a rack 146, one end of the rack 146 has threadedly adapted thereto in linear alignment with said rack 146, a threaded, elongated bar 147 having a distal end 148, and the distal end 148 of the elongated bar 147 linearly extends outside the rack and pinion housing 134.
There is a piston 149 having a center aperture 150 and an outside perimeter 151, and the piston 149 is detachedly mounted on the elongated bar 147 through the aperture 150. The piston 149 is housed in a piston housing 152 having an inside surface 153 and the piston 149 has one or more seals 154 around the outside perimeter 151 to seal the piston 149 against the inside surface 153 of the piston housing 152.
The piston housing 152 has two separable ends 155 (right end 155' is shown in phantom in FIG. 17), each separable end 155 and 155' has an outside perimeter 156 and at least two rod openings 157 near the outside perimeter 156. Each of the ends 155 being coupled to the piston housing 152 by two or more elongated rods 158 (shown in phantom in FIG. 17), each said elongated rod 158 having threaded ends 159.
The coupling is provided by threaded fasteners 160 on each of the threaded ends 159, each said threaded fastener 160 being compressed tightly against the separable ends 155.
There is a means of powering the piston 149 which is not shown, but the connections 203 are shown in FIG. 17, and a means 204 of controlling the movement of the piston 149 is shown in FIG. 17 at the vertical post 120.
FIG. 18 shows an enlarged view of the connection of the elongated bar 147 to the piston 149 and the threading of the elongated bar 147 into the rack 146. There is shown the center aperture 150 in the piston, seals 205, bolts 206, and the centering plate 207.
Turning now to FIG. 19, associated with the devices of this invention is a novel control valve 161 that is used on the lift chairs thereof. The novel control valve 161 comprises a base 162 and surmounted on said base 162, are two independent, essentially identical control blocks 163 and a solid wall block 164, one such control block 163 being surmounted by the wall block 164, the other control block 163 surmounting the wall block 164.
There is a means 165 (shown in phantom in FIG. 19) of locking the blocks 163 and 164 in a rigid configuration.
The wall block 164 (FIG. 20) has two side walls, a front side wall 166 and a back side wall 166', a top surface 167, a bottom surface 168 not shown in FIG. 20, a left end 169 and a right end 170. The wall block 164 extends beyond the control blocks 163 on the right end 170, and the wall block 164 has an elongated notch 171 at the right end 170 thereof. As shown in FIG. 21, the notch 171 extends through the wall block 164 from the top surface 167 through the bottom surface 168, said wall block 164 having an aperture 172 through the right end 170 extending from the front side wall 166 through the back side wall 166'.
As shown in FIG. 19, each control block 163 has a front side wall 173 and a back side wall 174 (equivalent but not shown in FIG. 19), a right end 175 and a left end 176 and an open center core 177 (Figure) having an internal surface 178, said open center core 177 running through each said control blocks 163 from the right end 175 to the left end 176. Each of the front side walls 173 has two ports 206 therein extending through to the open center core 177. The ports 206 are spaced apart and located nearer the right end 175 of the front side walls 173 of the control blocks 163. Each of the back side walls 174 have two ports 179 therein extending through to the open center core 177 (FIG. 23), said ports 179 being spaced apart and located nearer the left end 176 of the back side walls 174 of the control block 163. The ports and the center core are intended to openly communicate with each other when the valve stems are activated.
With reference to FIGS. 22 to 25, each said open center core 177 contains four elastomeric seals 180, said seals 180 being circular in configuration and conforming essentially to the diameter of the internal surface 178 of the open center core 177. As shown in FIG. 22, one each of the seals 180 is positioned such that it is located adjacent a port 179 opening through the back side wall 174 to prevent leakage of air or fluid around the valve stems 181.
There are two identical valve stems 181 in each control valve 161 capable of having an active position and being located respectively in the open center core 177 such that the valve stems 181 extend beyond each of the left ends 182 and right ends 183 of the combination of control blocks 163 and wall block 164.
Each valve stem 181 has a right end 184 and a left end 185, a front side wall 186 and a back side wall 187. Each valve stem 181 has spring supports 188 on the left end 185 thereof, each said spring support 188 having a compressible spring 189 slidably mounted thereon.
Each of the valve stems 181 have two notches or grooves 190 in each of the side walls 186 and 187, extending from the top 191 to the bottom 192, each notch 190 in the front side walls 186 being aligned with a respective port 178 in the front side wall 173 of the control blocks 163 when the valve stem 181 is in an active position and each notch 190 in the back side wall 187 of the valve stem 181 being aligned with a respective port 179 in the back side wall 174 of the control blocks 163 when the valve stem 181 is in an active position.
There is additionally, a means to retain each valve stem 181 in the open center core 177, such as a retainer ring 191.
At the left end, a valve stem reception cover 192 covers the left end 185 of the valve stem 181 and compressible spring 189, said cover 192 (FIGS. 27 and 28) has a back wall 193 (not shown) with an internal surface 194 (not shown) and said cover 192 being detachedly fixed by a fastener 207 to the combination of control blocks 163 and wall block 164.
The internal surface 194 of said back wall 193 has a centered indention 195 therein to accommodate the spring support 188 when a respective valve stem 181 is advanced in the open center core 177, each indention 195 having an aperture 196 centered therein through the back wall 193 thereof to allow for the release of air that is pushed into the indentions 195 when the valve stems 181 advance.
Returning to FIG. 19, the extended right end 184 of each of the valve stems 181 is contacted by a control handle 197, said control handle 197 being comprised of an elongated rod 198 surmounted by a gripping knob 199, said elongated rod 198 having a lower end 208, said lower end 208 having an aperture 200 therethrough, the aperture 200 in said control handle 197 being aligned with the aperture 172 in the side walls 201 of the right end 170 of the wall block 164 and having a pin 202 inserted therethrough to lock the control handle 197 in the wall block 164 such that the lower end 208 of the elongated rod 198 does not rest on the base 162.
The control valve 161 is hooked into a pressurized system through the ports 179 and 206 to provide a power means for operating the control valve 161. With regard to FIG. 19, the control valve 161 is operated by moving the control handle 197 either forward or backward to actuate the valve stems 181. In FIG. 19, if the control handle 197 is pushed forward (towards the control valve 161), the top valve stem 181 is activated and when the control handle 197 is pulled away from the control valve 161, the bottom valve stem 181 is activated. By activation, the inventor herein means that the ports and valve stem are aligned such that two sets on either the upper or lower level of the control valve blocks allow the passage of air or liquid to drive the lift chair of the devices of this invention.
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The disclosure herein deals with a series of devices for moving an invalid or handicapped person from a poolside into a pool, and back to the poolside, wherein the invalid or handicapped person may be responsible for the total movement without the aid of a second person. The devices have a novel feature, which is the fact that they can be moved and controlled by the occupant of the lift chair during that movement without the use of direct electrical power.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to fans for cooling engines and to the control of such fans for accurately matching the cooling needs of the engine.
[0003] 2. Description of the Related Art
[0004] Engines, such as the engines of automotive vehicles, generate heat during use and are subject to broad ranges of environmental heat. Accordingly, engines must be cooled to prevent overheating. The cooling needs of the engine are dependent upon characteristics of the engine, ambient temperature and the operating speed of the engine. Most engines are cooled by a liquid coolant that flows through channels in proximity to the engine. Heat from the engine is transferred to the coolant, and the heated coolant then passes through a heat exchanger or radiator. A fan directs cool air through the radiator to effect the cooling of the liquid.
[0005] The cooling rate is dependent partly upon the temperature of the cooling liquid, the temperature of the air and the rate of flow of the cooling air. The rate of flow of cooling air is dependent upon the rotational speed of the fan, and the speed of the vehicle.
[0006] Some prior art engines are configured to have the fan rotate sufficiently fast to accommodate all anticipated cooling needs. However, the fan is driven by the engine, and hence the engine operates less efficiently when there is more energy diverted to the operation of the fan. Additionally the rotating fan creates noise that is roughly proportional to the rotating speed of the fan. Thus, the fans in these prior art systems often generate more fan noise than is required.
[0007] Problems associated with fan noise and engine operating efficiencies are well known in the art, and there have been many efforts to match the fan speed to the cooling needs of the engine. The assignee of the subject invention has done considerable work in the field of fan fluid clutches that have proved to be very effective in matching the fan speed to the cooling needs of the engine.
[0008] The typical fan fluid clutch has a driving disc fixedly mounted to a rotating shaft of an engine. Thus, the driving disc rotates at the speed of the shaft of the engine. A housing is mounted rotatably to the shaft by bearings. Thus, the rotating shaft does not rotate the housing directly. Fan blades are mounted to the exterior of the housing. The interior of the housing includes a torque transmission chamber that surrounds the drive disc and an oil reservoir spaced from the torque transmission chamber. However, one or more oil supply holes and an oil recirculation passage provide communication between the oil reservoir and the torque transmission chamber.
[0009] A torque transmission fluid is placed in the oil reservoir and can flow into the torque transmission chamber via the oil supply hole between the oil reservoir and the torque transmission chamber. The torque transmission fluid transmits torque from the drive disc to the housing in proportion to the contact area of the torque transmission fluid with both the drive disc and the housing.
[0010] A valve is mounted in the housing and controls the oil supply hole between the oil reservoir and the torque transmission chamber. The valve opens when cooling needs are high. Hence, more oil will flow into the torque transmission chamber at these times. The greater amount of oil in the torque transmission chamber results in greater torque transmission between the drive disc and the housing. Under these conditions, the housing and the fan blades thereon rotate faster to provide more cooling. The valve closes the oil supply hole between the oil reservoir and the torque transmission chamber when cooling needs are low. As a result, less oil will flow into the torque translation chamber and the drive disc will transmit less torque to the housing. Under these conditions, the housing rotates more slowly and the fan blades on the housing direct less cooling air towards the engine. Additionally less energy is diverted from the engine to the fan when cooling needs are low, and therefore the engine operates more efficiently.
[0011] Fan fluid clutches are described extensively in the patent literature, including many U.S. patents assigned to the assignee of the subject invention. The simplest of these devices provides a temperature sensor, such as a bi-metal strip, at an exterior position on the housing. The temperature sensor communicates with the valve to open the oil supply hole during periods of high temperature and to close the oil supply hole during periods of lower temperatures.
[0012] More sophisticated fan fluid clutches have been developed in recent years and provide more inputs for controlling the movement of the valve that opens and closes the oil supply hole between the oil reservoir and the torque transmission chamber. These more sophisticated systems measure conditions such as: ambient temperature, vehicle speed, engine speed, air conditioning operating parameters, transmission oil temperature and the like. A controller is programmed with logic to determine a target fan speed (TFS) based on an analysis of these inputs. The controller then operates an electromagnet to move the valve relative to the oil supply hole. More particularly, the controller is programmed and calibrated to turn the electromagnet on and off for opening and closing the valve at a “duty rate” (DR) that is intended to achieve the appropriate volume of oil in the torque transmission chamber, and hence to achieve the target fan speed TFS. A prior art system that provides for outside control of the fan coupling is shown, for example in U.S. Pat. No. 6,550,596 and U.S. Pat. No. 6,915,888, which are assigned to the assignee of the subject invention. The disclosures of U.S. Pat. No. 6,550,596 and U.S. Pat. No. 6,915,888 are incorporated herein by reference.
[0013] Some recent efforts in the field of externally controlled fan drives employ “smart fluid” in a torque transmission chamber. These systems use a constant volume of fluid in the torque transmission chamber, and hence avoid the use of condition responsive valves to control the volume of fluid in the torque transmission chamber. Rather, these recent efforts attempt to control the torque transmission characteristics of a fixed volume of fluid. For example, a magnetic field can be applied in a controlled manner to alter the viscosity of the torque transmission fluid. Examples of these externally controlled fan drives are described in U.S. Pat. No. 5,960,918, U.S. Pat. No. 6,032,772, U.S. Pat. No. 6,102,177, U.S. Pat. No. 6,318,531 and U.S. Pat. No. 6,585,092, the disclosures of which are incorporated herein by references.
[0014] Prior art externally controlled fan devices (ECFD's) are better at achieving the target fan speed when the engine and the fan coupling apparatus are new. However, the ability to achieve the target fan speed TFS deteriorates over time. This deterioration is due to gradual wear of components in the fan coupling device and/or changes in the viscosity of the torque transmission fluid. These externally controlled fan devices measure the actual fan speed AFS and compare the actual fan speed AFS to the target fan speed TFS. These devices then change the duty rate DR in an effort to narrow or eliminate the difference between the target fan speed TFS and the actual fan speed AFS. However, the control logic in the prior art controller is calibrated based on new fan coupling apparatus and hence may not consistently match the target fan speed TFS if the externally controlled fan drive undergoes deterioration over time. As a result, these recent prior art externally controlled fan drives tend to swing the actual fan speed AFS substantial amounts to one side or the other of the target fan speed TFS. Prior art externally controlled fan drives that focus directly on the duty rate DR often provide less cooling than is required or more cooling, and hence less efficient engine operation. U.S. Pat. No. 6,807,926 is one example of a prior art externally controlled fan drive that includes actual fan speed as an input to the controller. This system has plural oil supply holes and plural valves. The duty rate DR of the respective valves are changed independently of one another in an effort to bring the actual fan speed AFS closer to the target fan speed TFS. However, a plural valve system is more complex then a single valve system. Furthermore, externally controlled fan drives that focus primarily on the duty rate DR are known to swing widely on one side or the other of the target fan speed TFS, as explained above.
[0015] Accordingly, an object of the subject invention is to provide an outside control-type fan coupling apparatus that provides optimum cooling for an engine substantially uniformly over a long period of time.
SUMMARY OF THE INVENTION
[0016] The invention relates to an adaptive control system for an externally controlled fan drive. The mechanical components of the externally controlled fan drive may be similar to the fan drive developed by the assignee of the subject invention and disclosed in the above-referenced U.S. Pat. No. 6,550,596 or U.S. Pat. No. 6,915,888. In particular, the fan drive may include a drive disc mounted to a shaft that is rotatably driven by the engine. The fan drive further includes a housing rotatably mounted relative to the shaft by bearings. An array of fan blades may be mounted to the exterior of the housing.
[0017] A fluid reservoir and a torque transmission chamber may be formed in the housing. The torque transmission chamber surrounds the drive disc with a small gap therebetween. An oil supply hole may be formed in the housing to provide communication between the fluid reservoir and the torque transmission chamber. A recirculation passage then may be provided at a radially outer position on the housing to provide a return flow path between the torque transmission chamber and the fluid reservoir.
[0018] A torque transmission fluid is provided in the housing and may circulate from the fluid reservoir to the torque transmission chamber back to the fluid reservoir. The torque transmission fluid has a consistency and viscosity to transmit torque from the drive disc to the housing. Thus, the torque transmission fluid enables the housing to be rotated in response to rotation of the drive disc. The amount of torque transmitted from the drive disc to the housing may be a function of the amount of torque transmission fluid in the torque transmission chamber. However, the amount of torque transmitted also may be a function of the characteristics of the fluid (e.g. viscosity) for a system using a fluid with controllable torque transmission characteristic.
[0019] A valve may be provided in the housing for selectively opening and closing the oil supply hole between the fluid reservoir and the torque transmission chamber. Thus, the amount of torque transmission fluid that can flow into the torque transmission chamber may be determined by the operation of the valve. The valve preferably is operated by an electromagnet that repeatedly opens and closes the valve at a duty rate for controlling the flow of torque transmission fluid through the oil supply hole. Alternatively, an electromagnet may be used to vary the viscosity of the torque transmission fluid.
[0020] The fan drive of the subject invention further includes an external controller. The controller is operative to receive input data relating to parameters that affect cooling needs. The inputs to the controller may include the throttle position, vehicle speed, engine speed, air conditioner operating conditions, transmission oil temperature, ambient temperature, actual fan speed and the like. The output of the controller may be a specified duty rate intended to achieve a target fan speed.
[0021] As noted above, the efficiency of the prior art external control apparatus for a fan fluid coupling changes over time. Even though the control apparatus works well initially, effectiveness and efficiency degrade over time. Accordingly, the externally controlled fan drive of the subject invention includes an adaptive controller that continuously adjusts the control logic based on the sensor inputs, including the past and existing actual fan speeds. The adaptive controller may use a deterministic autoregressive moving average (DARMA) model where the current output is represented as a linear combination of past outputs and past and present inputs. Alternatively, other adaptive models may be used. Furthermore, a recursive least square algorithm may be used to continuously estimate the coefficients of the model. As a result, the adaptive controller does not merely change the duty rate, but continually revises the control logic based on a continual analysis of past and present outputs and inputs. Furthermore, the assessment of trends performed by the adaptive controller permits the adaptive controller to predict performance trends. Thus, in certain instances, the control logic can be altered preemptively to avoid a time delay between an assessment of operating conditions and a response to those operating conditions. Accordingly, the adaptive controller provides the optimum control algorithm for the current operating condition of the fan drive. The adaptive controller also can be used to compensate for changes to original equipment in a vehicle (e.g., air conditioning vs. no air conditioning or automatic transmission vs. standard transmission) without a complex recalibration of the controller.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a longitudinal view of an external control fan coupling device in accordance with the subject invention.
[0023] FIG. 2 is a schematic view of the adaptive controller and fan device of the subject invention.
[0024] FIG. 3 is a schematic view of an alternate adaptive controller with means for fixed control during a short interval prior to startup of an engine.
[0025] FIGS. 4 a - 4 d show the performance of an adaptive externally controlled fan coupling device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] An externally controlled fan device (ECFD) in accordance with the invention is identified generally by the numeral 10 in FIG. 1 . The fan device 10 is used with an engine 12 , such as the internal combustion engine of an automotive vehicle. The engine 12 generates heat and must be cooled to ensure continued efficient performance. Accordingly, a cooling fluid is circulated in and near critical parts of the engine 12 . Heat from the engine is transferred to the coolant, thereby raising the temperature of the cooling fluid. The heated cooling fluid then is circulated through a radiator that is identified generally by the numeral 14 . The fan device 10 is operative to generate a flow of air adjacent to the various heat exchange channels in the radiator 14 for cooling the fluid that had been heated by the engine 12 . The cooler fluid then is recirculated back to the engine 12 . The cooling needs of the engine 12 vary in accordance with several parameters, including the throttle position, the speed of the engine 12 , ambient air temperature, air conditioning operating characteristics, coolant temperature and such. The externally controlled fan coupling device 10 functions to generate flow of cooling air sufficient to achieve a heat transfer in the cooling fluid so that the cooling fluid can cool the engine appropriately.
[0027] The fan coupling device 10 is mounted to a shaft 16 that is driven by the engine 12 . A drive disc 18 is mounted fixedly to an end of the shaft 16 , and hence rotates at the input speed of the shaft 16 and the engine 12 .
[0028] A sealed housing 20 is mounted rotatably on the shaft 16 . More particularly, the sealed housing 20 includes a casing 22 mounted around a portion of the shaft 16 by bearings 24 . Thus, the shaft 16 rotates substantially independently of the casing 22 . The casing 22 is formed to define an oil reservoir 26 that is enclosed by a partition 28 . The drive disc 18 is mounted to a portion of the shaft 16 that projects beyond the casing 22 and the partition 28 . The sealed housing 20 further includes a cover 30 mounted substantially rigidly to the casing 22 . Thus, the casing 22 , the partition 28 and the cover 30 are rotatable in unison and substantially independently of the shaft 16 and the drive disc 18 . Fan blades 32 are mounted to the exterior of the sealed housing 20 and rotate with the sealed housing 20 to generate a flow of cooling air across the radiator 14 .
[0029] The casing 22 , the partition 28 and the cover 30 are configured to define a torque transmission chamber 34 that surrounds the drive disc 18 . An oil supply hole 36 extends through the partition 28 at a substantially radially outer position of the oil reservoir 26 to provide communication between the oil reservoir 26 and the torque transmission chamber 34 . An oil recirculation passage 38 is formed through the casing 22 and provides communication between a radially outer position in the torque transmission chamber 34 and the oil reservoir 26 . A dam 40 is disposed at a radially outer position in the torque transmission chamber 34 and in proximity to the oil recirculation passage 38 .
[0030] A viscous oil is disposed initially in the oil reservoir 26 , but can flow through the oil supply hole 36 and into the torque transmission chamber 34 . Oil in the torque transmission chamber 34 will transfer torque from the drive disc 18 to the sealed housing 20 . As a result, the sealed housing 20 will rotate with the drive disc 18 , and the fan blades 32 on the sealed housing 20 will generate a flow of cooling air across the radiator 14 . Centrifugal forces will urge the oil into outer positions in the torque transmission chamber 34 . The dam 40 then will urge the oil into the oil recirculation passage 38 and back to the oil reservoir 26 .
[0031] The amount of torque transferred from the drive disc 18 to the sealed housing 20 varies in accordance with the amount of oil in the torque transmission chamber 34 . More oil in the torque transmission chamber 34 transmits more torque from the drive disc 18 to the sealed housing 20 . This greater torque results in greater rotational speeds of the sealed housing 20 and hence a higher flow of cooling air generated by the fan blades 32 . Less oil in the torque transmission chamber 34 results in a lower torque transfer from the drive disc 18 to the sealed housing 20 . The lower torque results in lower rotational speeds of the sealed housing 20 and hence a lower flow of cooling air generated by the fan blades 32 .
[0032] The amount of oil in the torque transmission chamber 34 is controlled by a valve 42 mounted in the oil reservoir 26 in a position for selectively opening and closing the oil supply hole 36 . More particularly, the valve 42 includes a leaf spring 44 with a fixed end 46 and a movable end 48 . The leaf spring 44 can be deflected from a position where the movable end 48 of the leaf spring 44 closes the oil supply hole 36 to a position where the movable end 48 of the leaf spring 44 opens the oil supply hole 36 . Movement of the leaf spring 44 into a position for closing the oil supply hole 36 will interrupt the flow of oil into the torque transmission chamber 34 without interrupting the flow of oil from the torque transmission chamber 34 , through the oil recirculation passage 38 and back into the reservoir 26 . Hence, movement of the leaf spring 44 into a position for blocking the oil supply hole 36 will result in a gradual reduction of the amount of oil in the torque transmission chamber 34 , thereby resulting in less torque transmitted from the drive disc 18 to the sealed housing 20 . As a result, the closing of the oil supply hole 36 by the leaf spring 44 lowers the rotational speed of the sealed housing 20 and decreases cooling effect achieved by the fan blades 32 . Conversely, movement of the leaf spring 44 into a position for opening the oil supply hole 36 results in a greater flow of oil from the oil reservoir 26 into the torque transmission chamber 34 . As a result, movement of the leaf spring 44 into position for opening the oil feed hole 36 permits a greater torque transfer from the drive disc 18 to the sealed housing 20 . Consequently, the sealed housing 20 will rotate faster and the fan blades 32 will generate a higher flow of cooling air.
[0033] The opening and closing of the oil supply hole 36 is controlled by an electromagnet 50 mounted rotatably on the shaft 16 and opposed to a portion of the casing 22 near the valve 42 . In particular, activation of the electromagnet 50 will attract an armature 52 on the leaf spring 44 and will urge the leaf spring 44 away from the oil supply hole 36 . Conversely, the leaf spring 44 will return resiliently to a position for closing the oil feed hole 36 when the electromagnet 50 is deactivated. The electromagnet 50 is pulse width modulated PWM to sequentially open and close the oil supply hole 36 . The duty rate DR of the pulse width modulated signal controls the proportion of time that the valve 42 remains open. The pulse width modulated duty rate DR can vary between 0%, corresponding to a valve 42 that is not opened and 100%, corresponding to a valve 42 that is open continuously. During most operating conditions, the duty rate DR will be between these two extremes. The valve 42 will open more often and/or for longer times to generate greater flows of cooling air. Conversely, the valve 42 will close more often and/or for longer periods of time to achieve less cooling.
[0034] The duty rate DR achieved by the electromagnet 50 is based on a control signal that is input to the electromagnet 50 from an adaptive controller 54 b , which in turn receives input from an external input analyzer 54 a . The external input analyzer 54 a generates a target fan speed TFS required to achieve the necessary cooling based on information from different sensors, such as engine coolant temperature sensors, intake air temperature sensors, a vehicle speed sensor, an engine speed sensor, a throttle position sensor and a sensor for air conditioner operating conditions. The algorithm or logic utilized by the external input analyzer may vary from one vehicle to another and typically the logic or the algorithm will be developed by the vehicle manufacturer. The control signal will dictate a target fan speed TFS appropriate for achieving the necessary cooling. This differs from the prior systems where the control signal generates a precalibrated duty rate DR associated with a target fan speed TFS.
[0035] As noted above, physical characteristics of the externally controlled fan device 10 may result in an actual fan speed AFS that differs from the target fan speed TFS that was intended to have been produced by the duty rate DR dictated by the controller. This difference between the actual fan speed AFS and the target fan speed TFS can be caused by dimensional differences attributable to manufacturing tolerances. Alternatively, the difference between the actual fan speed AFS and the target fan speed TFS can be attributable to physical changes in the externally controlled fan device 10 that develop over time. For example, the viscosity of the oil may change, wear debris may accumulate in the oil, the resiliency of the leaf spring 44 can change, the bearing 24 can wear or parts of the fan coupling device 10 may be damaged due to unintended contact. Any of these changes can cause the actual fan speed AFS to be less than the target fan speed TFS or greater than the target fan speed TFS. Additionally, any of these conditions can cause the actual fan speed AFS to be greater than the target fan speed TFS under certain operating conditions, but less than the target fan speed TFS under other operating conditions.
[0036] In view of the above, the controller 54 b of the externally controlled fan coupling device 10 is an adaptive controller. The adaptive controller 54 b is operative for measuring the actual fan speed AFS and then using the measured actual fan speed AFS as an input. The duty rate DR also is an input. The adaptive controller 54 b then uses the various inputs over time, including the duty rate DR and the actual fan speed AFS, and generates an updated control algorithm or logic to achieve a duty rate DR that will keep the actual fan speed AFS at or very near the target fan speed TFS.
[0037] The application of the adaptive controller 54 b to the fan device 10 is illustrated schematically in FIG. 2 . More particularly, the target fan speed TFS illustrated in FIG. 2 is determined based on sensors at various locations in the vehicle. The specification of the sensors may vary from one vehicle manufacturer to another. However, as noted above, sensors may be operative to identify ambient temperature, coolant temperature, engine speed, vehicle speed and the like. These data are inputs to the external input analyzer 54 a . The external input analyzer 54 a includes certain logic, i.e. an algorithm, that relate these inputs to a target fan speed TFS. The target fan speed TFS is an input to the adaptive controller 54 b and specifically to the valve control algorithm unit 56 thereof. The algorithm includes certain coefficients and produces a duty rate DR as an output to the externally controlled fan device 10 . The existing duty rate DR also is provided as an input to the control law update unit 58 of the adaptive controller 54 b . Torque is transmitted to the sealed housing 20 and rotates the housing 20 at an actual fan speed AFS based on the duty rate DR and physical characteristics of the fan device 10 existing at a particular point in time. The actual fan speed AFS and the duty rate DR then are inputs back to the control law update unit 58 of the controller 54 b . The control law update unit 58 may employ a deterministic autoregressive moving average (DARMA) model or other such model to represent the performance of the ECFD 10 . A DARMA model representation of the externally controlled fan device (ECFD) 10 input-output behavior may be given by the relationship:
a 0 AFS ( t ) = - ∑ j = 1 n 1 a j AFS ( t - j ) + ∑ j = 0 m 1 b j DR ( t - j - d ) ; t ≥ 0
More particularly, the control law update unit 58 uses certain algorithms, like the recursive least square algorithm, along with past values of AFS and present and past values of DR to estimate the model coefficients a j and b j that will best represent the present behavior of the ECFD 10 . After these model coefficients are identified, they are used in the control law update unit 58 for solving a series of equations to estimate new control coefficients (p 1 , p 2 , I 1 , I 2 , M, etc) to determine a new duty rate DR value. The valve control algorithm 56 to calculate the duty rate may be substantially as follows:
DR ( t ) = 1 l 1 [ M ( TFS ( t ) ) - ( p 1 AFS ( t ) + p 2 AFS ( t - 1 ) ) - l 2 DR ( t - 1 ) ]
As a result, the control law update unit 58 may use the model coefficients to update the control logic in order to dictate a new duty rate DR for more closely matching the actual fan speed AFS to the target fan speed TFS. This process is carried out continually to ensure that the actual fan speed AFS is at or very close to the target fan speed TFS throughout the operation.
[0038] FIGS. 4 a - 4 d demonstrates actual test data. The test was carried out using a temperature control test bed referred to herein as a “hot box”. The hot box is an enclosed system having a main drive motor with a speed control. The inside temperature is maintained constant at preset values with the help of a PLC controller. The fan clutch system was coupled to the shaft of the motor and positioned in a shroud of known diameter to simulate the in-vehicle system resistance. The electric motor use in the test is capable of running at speeds up to 4,500 RPM. A fiber-optic speed sensor was mounted in the hot box near the motor shaft to measure the in put shaft speed (IS).
[0039] The experimental adaptive controller used a rapid prototyping system for converting each signal into signals that can be inputted into a computer with provisions for interfacing the clutch cable and the fiber-optic speed sensor. Frequency to-voltage converters were used to convert the input speed reading and the fan speed reading from frequency to voltage signals, which were then fed to two channels of an A/D board. Tests then were performed at various input speeds and various target fan speeds. The test results are illustrated in FIGS. 4 a - 4 d . In each of these figures, the horizontal line IS represents the input speed, which correspondence to the rotational speed of the shaft 16 shown in FIG. 1 . The stepped rectangular line shown in these figures represents the target fan speed entered as an input to the test apparatus. In actual practice, the target fan speed TFS would be developed based on inputs from various sensors on the vehicle. The actual fan speed AFS is represented by the non-rectangular and non-linear line on the grafts. These grafts show that the adaptive externally controlled fan drive 10 was able to have the actual fan speed AFS closely follow the target fan speed TFS at different input speeds and with frequent changes in the target fan speed TFS.
[0040] The above-described procedure cannot be used directly when the engine is started because there is no history for assessing the ability of the duty rate DR to achieve the actual fan speed AFS. Accordingly, FIG. 3 shows a controller that further includes a fixed gain PID controller that utilizes a known specified algorithm to produce a duty rate DR that ideally would achieve the target fan speed TFS. The apparatus of FIG. 3 further includes a switch 60 that switches to the above-described adaptive controller 54 b after a sufficient history of duty rates DR and actual fan speeds AFS can be developed following the engine startup. The switch 60 typically can be activated after 60-120 seconds of engine operation.
[0041] The adaptive controller 54 can be used for other purposes as well. For example, the externally controlled fan coupling device 10 may be calibrated for a particular vehicle with a specific array of accessories. A vehicle manufacturer may provide different arrays of accessories for certain vehicles in a particular line of vehicles. For example, some vehicles from a manufacturer may have a unique air conditioning system that could significantly affect the externally controlled fan device 10 . In the prior art, such a change would require a complex, time consuming and costly recalibration of the controller for externally controlled fan coupling device 10 . However, the adaptive controller 54 can avoid such complex recalibration. In this regard, the adaptive controller 54 will generate signals to adjust the duty rate DR up or down so that the actual fan speed AFS conforms to the cooling requirements.
[0042] The invention has been described with respect to a preferred embodiment of an externally controlled fan device 10 . However, it will be understood by those skilled in the art that the adaptive controller of the subject invention can be used with other types of fluid clutches. For example, the adaptive controller can be used with the above-identified fluid clutches that employ a “smart fluid” with a viscosity that can be varied for altering the torque applied to the casing of the fan device. More particularly, the adaptive controller may update the control logic that operates the electromagnet to change the viscosity of the liquid in much the same way that the duty rate of a valve is varied.
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An externally controlled fan drive includes a fluid clutch that alters torque delivered to a fan housing to rotate the fan housing at a target fan speed. An adaptive controller measures the actual fan speed and adaptively updates the control logic to compensate for variable physical characteristics of the fan device.
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FIELD OF THE INVENTION
[0001] The present invention relates to new chemical entities and the incorporation and use of the new chemical entities as fragrance materials.
BACKGROUND OF THE INVENTION
[0002] There is an ongoing need in the fragrance industry to provide new chemicals to give perfumers and other persons ability to create new fragrances for perfumes, colognes and personal care products. Those with skill in the art appreciate how differences in the chemical structure of the molecule can result in significant differences in the odor, notes and characteristics of a molecule. These variations and the ongoing need to discover and use the new chemicals in the development of new fragrances allows perfumers to apply the new compounds in creating new fragrances.
SUMMARY OF THE INVENTION
[0003] The present invention provides novel chemicals, and the use of the chemicals to enhance the fragrance of perfumes, toilet waters, colognes, personal products and the like. In addition, the present invention is directed to the use of the novel chemicals to enhance fragrance in perfumes, toilet waters, colognes, personal products and the like.
[0004] More specifically, the present invention is directed to the novel compounds, represented by the general structures of Formula I and Formula II set forth below:
wherein R is a hydrocarbon moiety consisting of 2 to 10 carbon atoms, including cyclopentyl, cyclohexyl, phenyl, benzyl, or phenylethyl. R1 is either methyl or ethyl.
[0005] Another embodiment of the invention is a method for enhancing a perfume by incorporating an olfactory acceptable amount of the compounds provided above.
[0006] These and other embodiments of the present invention will be apparent by reading the following specification.
DETAILED DESCRIPTION OF THE INVENTION
[0007] In Formula I and Formula II above, R represents a hydrocarbon, a cyclic, or an aromatic group consisting of 2 to 10 carbon atoms, most preferably, R is a pentyl group. Hydrocarbon, cyclic or aromatic R groups include, but are not limited to the straight alkyl, cyclic, and aromatic chains. Suitable straight hydrocarbon moieties include ethyl, propyl, butyl, cyclopentyl, cyclohexyl, and the like. Suitable branched hydrocarbon moieties include isopropyl, sec-butyl, tert-butyl, 2-ethyl-propyl, and the like. Suitable hydrocarbon moieties containing double and triple bonds include ethene, propene, 1-butene, 2-butene, penta-1-3-deine, hepta-1,3,5-triene, butyne, hex-1-yne and the like. Suitable aromatic moieties include phenyl, benzyl, phenylethyl and the like. In Formula II above, R1 represents a methyl or an ethyl group. Those with skill in the art will recognize that the compound of Formula I of the present invention has a chiral center, thereby providing several isomers of the claimed compound. As used herein the compounds described herein include the isomeric mixtures of the compounds as well as those isomers that may be separated using techniques known to those with skill in the art. Suitable separation techniques include chromatography, particularly gel chromatography.
[0008] The compounds of the present invention may be prepared from the following compound of Formula III:
[0009] The preparation and use of the compound of Formula III is discussed in U.S. Pat. No. 4,585,662, the contents of which are incorporated herein by reference. In the Formula III, R has the same definition as set forth above.
[0010] The compound of Formula I may be prepared from the compound of Formula III by following the Oppenauer oxidation reaction procedure (see Example A). The amount of ketone recovered after the reaction is completed is from about 70% to about 95% by weight of the product mixture. We have discovered that the compounds of Formula I have green, pleasant notes that are well suited for use as a fragrance ingredeint.
[0011] The compound of Formula II may be prepared by nucleophilic addition of an appropriately substituted alkyl, cyclic or aromatic Grignard reagent or alkyl lithilum to the compound of Formula I (see Example C). We have discovered that the compounds of Formula II have a banana fruity note with violet, soft green tones that are well suited for use as a fragrance ingredient.
[0012] The use of the compound of the present invention is widely applicable in current perfumery products, including the preparation of perfumes and colognes, the perfuming of personal care products such as soaps, shower gels, and hair care products as well as air fresheners and cosmetic preparations. The present invention can also be used to perfume cleaning agents, such as, but not limited to detergents, dishwashing materials, scrubbing compositions, window cleaners and the like.
[0013] In these preparations, the compounds of the present invention can be used alone or in combination with other perfuming compositions, solvents, adjuvants and the like. The nature and variety of the other ingredients that can also be employed are known to those with skill in the art.
[0014] Many types of fragrances can be employed in the present invention, the only limitation being the compatibility with the other components being employed. Suitable fragrances include but are not limited to fruits such as almond, apple, cherry, grape, pear, pineapple, orange, strawberry, raspberry; musk, flower scents such as lavender-like, rose-like, iris-like, carnation-like. Other pleasant scents include herbal and woodland scents derived from pine, spruce and other forest smells. Fragrances may also be derived from various oils, such as essential oils, or from plant materials such as peppermint, spearmint and the like.
[0015] A list of suitable fragrances is provided in U.S. Pat. No. 4,534,891, the contents of which are incorporated by reference as if set forth in its entirety. Another source of suitable fragrances is found in Perfumes, Cosmetics and Soaps , Second Edition, edited by W. A. Poucher, 1959. Among the fragrances provided in this treatise are acacia, cassie, chypre, cyclamen, fern, gardenia, hawthorn, heliotrope, honeysuckle, hyacinth, jasmine, lilac, lily, magnolia, mimosa, narcissus, freshly-cut hay, orange blossom, orchid, reseda, sweet pea, trefle, tuberose, vanilla, violet, wallflower, and the like.
[0016] Olfactory effective amount is understood to mean the amount of compound in perfume compositions the individual component will contribute to its particular olfactory characteristics, but the olfactory effect of the perfume composition will be the sum of the effects of each of the perfumes or fragrance ingredients. Thus the compounds of the invention can be used to alter the aroma characteristics of the perfume composition, or by modifying the olfactory reaction contributed by another ingredient in the composition. The amount will vary depending on many factors including other ingredients, their relative amounts and the effect that is desired.
[0017] The level of compound of the invention employed in the perfumed article varies from about 0.005 to about 10 weight percent, preferably from about 0.5 to about 8 and most preferably from about 1 to about 7 weight percent. In addition to the compounds other agents can be used in conjunction with the fragrance. Well known materials such as surfactants, emulsifiers, polymers to encapsulate the fragrance can also be employed without departing from the scope of the present invention.
[0018] Another method of reporting the level of the compounds of the invention in the perfumed composition, i.e., the compounds as a weight percentage of the materials added to impart the desired fragrance. The compounds of the invention can range widely from 0.005 to about 70 weight percent of the perfumed composition, preferably from about 0.1 to about 50 and most preferably from about 0.2 to about 25 weight percent. Those with skill in the art will be able to employ the desired level of the compounds of the invention to provide the desired fragrance and intensity.
[0019] The following are provided as specific embodiments of the present invention. Other modifications of this invention will be readily apparent to those skilled in the art. Such modifications are understood to be within the scope of this invention. As used herein all percentages are weight percent unless otherwise noted, ppm is understood to stand for parts per million and g is understood to be grams. IFF as used in the examples is understood to mean International Flavors & Fragrances Inc.
EXAMPLE A
Preparation of 4-methyl-3-decene-5-one
[0020] To a dry 2 liter multi-neck round bottom flask fitted with an air stirrer, nitrogen inlet condenser and an addition funnel 208 g of a 98% solution of Aluminum Isopropyloxide and 400 g of acetone (obtained from the Acros Organics) was added. The resulting mixture was stirred and gently heated. As the temperature of the mixture reached 64° C., 378 g of 90% solution of 3-decene-4-methyl-5-ol was slowly added over 90 minutes. The resulting mixture was aged for 90 minutes. At this point the temperature reached 80° C. and a first sample of the product was taken. Two hours later, as the temperature reached 85° C., a second sample was taken. The mixture was maintained at a constant temperature of 85° C. for 35 minutes, the heating source was removed and 100 ml of acetone was added. After 25 minutes, as the mixture reached 80° C., the mixture was cooled and quenched with 1 L of 10% hydrochloric acid. The products were allowed to settle. Then the organic layer was separated from the acid layer, washed with water and neutralized with 10% NaHCO 3 solution.
[0000] The NMR spectrum of the 4-methyl-3-decene-5-one is as follows: 0.88 ppm (m, 3H); 0.96 ppm (m 3H); 1.39 ppm (m, 2H); 1.51 ppm (m, 2H); 1.82 ppm (s 3H); 2.21 ppm (m, 2H); 2.71 ppm (m, 2H); 6.27 ppm (m, 1H)
EXAMPLE B
Incorporation of 4-methyl-3-decene-5-one into a Fragrance Formulation
[0021] A fragrance was prepared according to the following formulation:
Material Parts TRIPLAL EXTRA 1.00 AMBROXAN DIST 10.00 AMYL SALT 5.00 GERANIUM EGYPT SPECIAL 4.00 METH OCTIN CARBONATE 10% DPG 2.00 METH IONONE BETA COEUR 10.00 TIMBEROL DRAG 5.00 TONALID 50.00 ISO E SUPER 100.00 IONONE BETA EXTRA 8.00 ISO GAMMA SUPER 40.00 LYRAL 50.00 MANDARIN OIL YELLOW GATTO 30.00 POLYSANTOL (ELINCS) 5.00 VERAMOSS 5.00 ANETHOLE USP 1.00 PATCHOULI INDONESIA MD REF A LMR 2.00 PEACH ALD COEUR SPECIAL 10% DPG 0.50 LIFFAROME “PFG” 10% DPG 7.00 COUMARIN 5.00 ORANGE OIL SWEET GUINEA PECT + BHA 35.00 BERGAMOT OIL DEFUROCOUMARINIZED GATTO 42.00 FLORHYDRAL (ELINCS) 0.50 HEXENYL ACET, CIS-3 1.00 ETH LINALOOL HLR 45.00 ADOXAL 0.50 STYRALYL ACET 2.00 SANJINOL 50.00 LAVANDIN SUPREME CHAU 8.00 DIHYDRO MYCENOL 60.00 ROSEMARRY FRENCH VILLECROZE 1.00 ALLYL AMYL GLYCOLATE 5.00 HELIONAL 15.00 CANTHOXAL 15.00 CYCLOGALBANATE 3.00 FLORALOZOLE 5.00 LILIAL 50.00 NONADIENAL, 2-TR-6-CIS-“F + F” 0.1% DEP 6.00 RHODINOL COEUR 9.00 GALAXOLIDE BENZ SAL 50 PCT 250.00 SANDAL WOOD RECO 2004 YC-973 15.00 GALBASCONE 1% DPG 5.00 MANDARINAL 32048 SAE 3.00 DAMAROSE 0.50 CARVONE SPECIAL L-10% DPG 8.00 AURANTIOL GIV 10% DPG 6.00 SAGE CLARY FRENCH OIL REF A LMR 4.00 HEXENYL SAL, CIS-3 15.00 AMBREINE PURE 181400/3 BROWN 1% DEP 3.00 3-DECENE-4-METHYL-5-ONE 5.00
[0022] The above fragrance was found to be a pleasing fragrance with pleasing green notes. The above fragrance formulation was presented to demonstrate the effectiveness of the compounds of the present invention was enhancing, improving or modifying the performance of the formulations in which they are incorporated.
EXAMPLE C
Preparation of 4.5-Dimethyl-3-decene-5-ol
[0023] To a dry 5 liter multi-neck round bottom flask fitted with an air stirrer, nitrogen inlet condenser and an addition funnel 1.617 g of CH 3 Li was added and stirred. 336 g of 4-methyl-3-decene-5-one (see example A for preparation of 3-decene-4-methyl-5-one) was added dropwise over 105 minutes. The temperature of the reaction rose to 63° C. The reaction mixture was aged for 150 minutes and a first sample was taken at 37° C. 30 minutes later, a second sample was taken at 30° C. The mixture was quenched with acetic acid, allowed to settle and layers separated. The aqueous layer was washed twice with 100 ml of toluene. The toluene extracts were added to the organic layer and washed with Na 2 CO 3 .
[0000] The NMR spectrum of the 4.5-Dimethyl-3-decene-5-ol is as follows: 0.88 ppm (t, 3H); 0.94 ppm (t, 3H); 1.28 ppm (s, 3H); 1.15-1.35 ppm (m, 6H); 1.50 ppm (s, 1H); 1.55 ppm (s,1H), 2.05 ppm (m, 2H); ; 5.45 ppm (m, 1 H)
[0000] The IR spectrum of the 4.5-Dimethyl-3-decene-5-ol is as follows: OH-stretch broad at 3416 cm −1 . CH-stretch saturated at 2960, 2933, 2872 cm −1 double bond stretch at 1680 cm −1 , 1462 and 1372 due to CH stretch.
EXAMPLE D
Preparation of Alpha-[1-Methyl-1-Butenyl]-Cyclopentanemetanol
[0024] To a dry 2 liter multi-neck round bottom flask fitted with an air stirrer, nitrogen inlet condenser and an addition funnel 800 ml of 2 M of cyclopentyl magnesium chloride was added and stirred. 139 g of 2-methyl-2-pentenal was added over the next 90 minutes. The reaction mixture was aged for another 90 minutes and the first sample was taken. 25 minutes later the reaction mixture was quenched with water, aged for 30 minutes and the organic layer was separated and washed with 2 one liter portions of water.
[0000] The NMR spectrum of the Alpha-[1-Methyl-1-Butenyl]-Cyclopentanemetanol is as follows: 1.00 ppm (s, 3H); 1.1-1.2 ppm (s, 1H); 1.4-1.5 ppm (s, 2H); 1.5-1.7 ppm (m, 4H); 1.8 ppm (s, 1H); 2.1 ppm (m, 3H); 3.7 ppm (d, 1H); 5.4 ppm (t, 1H)
EXAMPLE E
Preparation of 1-Phenyl-4-Methyl-4-Hepten-3-one
[0025] To a dry 2 liter multi-neck round bottom flask fitted with an air stirrer, nitrogen inlet condenser and an addition funnel 168 g of 65% 1-Phenyl-4-Methyl-4-Hepten-3-ol, 51 g of 98% Aluminum Isopropoxide, (obtained from the Acros Organics) and 200 g of Acetone and 200 g of Toluene were added and stirred. The reaction mixture was slowly heated at reflux to 85° C. The samples were collected every our when the temperature of the reaction mixture was between 70° C. and 80° C.
[0000] The NMR spectrum of the 1-Phenyl-4-Methyl-4-Hepten-3-one is as follows: 1.0 ppm (t, 3H); 1.8 ppm (s, 3H); 2.2 ppm (m, 2H); 2.9-3.0 ppm (m, 2H); 6.6 ppm (t, 1H) 7.2 ppm (m, 3H); 7.28 ppm (s,1H), 7.3 ppm (s, 1H).
EXAMPLE F
Preparation of 1-cyclohexyl-3-methyl-3-hexene-1-ol
[0026] To a dry 2 liter multi-neck round bottom flask fitted with an air stirrer, nitrogen inlet condenser and an addition funnel 800 ml of 2 M of cyclohexyl magnesium chloride was added and stirred. The flask was cooled to 10° C. 146 g of 99% 2-methyl-2-pentenal was added over the next 135 minutes. The cooling was removed. The first sample was taken 50 minutes later at 13° C. The second sample was taken 35 minutes later at 18° C. 75 minutes later the reaction mixture was quenched with 1000 ml of 20% HAc with cooling. The layers were allowed to settle and the organic layer extracted with 100 ml of toluene.
[0000] The NMR spectrum of the 1-cyclohexyl-3-methyl-3-hexene-1-ol is as follows: 0.7-0.9 ppm (q, 1H); 0.9-1.0 ppm (t, 4H); 1.1-1.3 ppm (m, 3H); 1.6 ppm (s, 3H); 1.6-1.8 ppm (m, 4H); 2.0-2.1 ppm (m, 3H); 3.7 ppm (d, 1H); 5.4 ppm (t, 1H)
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The present invention is directed to novel ketone and alcohol compounds and the use of these novel compounds in creating fragrances, and scents in items such as perfumes, colognes and personal care products.
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FIELD OF THE INVENTION
This invention is directed to a unit configured so that a plurality of identical units can be snapped together to form a web which is sufficiently flexible to pass around supporting drums, with an article-supporting arm forming part of each unit so that articles are successively brought forward upon belt motion.
BACKGROUND OF THE INVENTION
The display of neckties for merchandising is extremely difficult because of the narrow width, long length, and flexibility thereof. Present-day merchandising displays of such articles are static, and to conserve space the several ties hanging upon the display device are necessarily close together and are, thus, not fully capable of properly displaying each tie. Other articles of similar configuration, such as belts, are also subject to the same problems.
The display problem is closely related to the storage problem because, when such articles are closely packed for dense storage, they cannot be properly displayed so that a selection can be made. Thus, there is need for an economic, compact and convenient structure where such articles can be stored and successively displayed.
SUMMARY OF THE INVENTION
In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to an article-supporting web-forming unit wherein a plurality of such web-forming units can be engaged together to form a flexible web, with each of the web-forming units having an article-supporting arm thereon. Each of the web-forming units has a panel thereon. A hook is secured to the inner end of the panel and is offset the thickness of the panel. Openings in the panel adjacent its outer end can be engaged by the hook on the adjacent identical panel so that a plurality of such panels are secured together to form a web. An article-supporting arm is secured to the panel.
It is, thus, a purpose and advantage of this invention to provide an article-supporting web-forming unit which is identical to adjacent such units and configured so that the adjacent units can snap together to form a flexible web, with each unit having an article-supporting arm thereon for successive display of an article.
It is another purpose and advantage of this invention to provide an article-supporting web-forming unit wherein an article can be supported on each such unit and the articles can be successively brought forward for display by moving the web formed by the units.
It is another purpose and advantage of this invention to provide a unit which is economic in construction and which can be interengaged with adjacent identical or similar such units to form a web which can be incorporated into a storage and display unit so that articles can be successively brought forward for display.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further purposes and advantages thereof, may be best understood by reference to the following description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a display unit incorporating the article-supporting web-forming unit of this invention.
FIG. 2 is an exploded view, showing two of the article-supporting web-forming units of this invention ready to be engaged together.
FIG. 3 is a side-elevational view of one of the article-supporting web-forming units of this invention.
FIG. 4 is a side-elevational view of two of such units engaged together.
FIG. 5 is a plan view of one of the units.
FIG. 6 is a section taken generally along the line 6--6 of FIG. 3.
FIG. 7 is a rear elevational view of the structure of FIG. 4.
FIG. 8 is a display unit incorporating a web formed by a plurality of the units of this invention, with parts broken away.
FIG. 9 is a section taken generally along the line 9--9 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The article display system 10 indicated in FIGS. 1, 8 and 9 incorporates web 12 shown in FIGS. 8 and 9. The web 12 is made up of a plurality of units with unit 14 shown in FIGS. 2, 3, 4, 5 and 6. Unit 14 is one of a plurality of identical interlocking units, and it is shown associated with unit 16 in FIGS. 2 and 4.
Considering unit 14 in detail, it is configured so that it can be injection-molded as a unitary structure of thermoplastic synthetic polymer composition material in a simple die. Unit 14 has a rectangular central panel 18 which has an inside surface 20 and an outside surface 22. These surfaces refer to the inside and outside of the web which is ultimately formed by joining a plurality of the units. At the outer end 24 of central panel 18, there are formed two slots 26 and 28. Toward the inner end 30 there are formed two slots 32 and 34. At the inner end 30 of the panel are attached upper and lower retainer hooks 36 and 38. These hooks are U-shaped when seen in plan view, as in FIGS. 5 and 6, with the inside of the U offset in the direction of outside 22 to be in alignment with the outside surface 22. The hooks are bifurcated and have barbs thereon, as is best seen on the corresponding upper and lower hooks 40 and 42 on unit 16 shown in FIG. 2. The barbs on the hooks are sufficiently far out on the hooks so that the distance from the lower surface of the barbs to the inside of the U of the retainer hooks is at least equal to the thickness of the panel 18. The retainer hook slots 26 and 28 are as long as the distance over the outer ends of the barbs when they are not compressed. Slots 32 and 34 are shorter, in the top-to-bottom direction seen in FIG. 3, so that the bifurcated fingers must be squeezed together to permit the tips of the barbs to enter therethrough. Once the hooks are pressed through the slots 32 and 34, the bifurcated fingers spring apart due to the resiliency of the material so that the barbs engage upon the inside surface 20 of the panel. The spacing between the barbed ends of the hooks and their connections with the panel members is greater than the spacing between slots 26 and 32 and slots 28 and 34. In assembling the structure, the upper and lower retainer hooks 36 and 38 are inserted first through the slots 44 and 46 of unit 16 and then the unit 14 is rotated to bring the barbed ends of the retainer hooks 36 and 38 out through slots 48 and 50 of unit 16. Dog 52 extends from the inside surface and is positioned between the slots 48 and 50. The dog and the ends of the retainer hooks beyond the barbs form a bar which is used to guide and propel the web, as is later described. It is, thus, seen that successive central panels with their barb retainer hooks successively engage together to form the web 12. The web is in effect a flexible belt.
In order to provide the article-supporting function, article support arm 56 is integrally molded with the central panel 18. As is seen in FIG. 8, the self-hinge 58 is a thin panel of the material of which the unit is molded. The material is sufficiently flexible so that a small amount of hinging is possible at the hinge 58. FIG. 2 shows the self-hinge 58 on unit 16 and self-hinge 60 on the unit 16. The unit 16 has an article support arm 62. The support arms extend away from the hinges and have a wide, shallow notch in the top. Notch 64 is shown with respect to support arm 56. Upstanding finger 66 defines the outer limit of notch 64 and serves to define a notch 64 which is sufficiently wide to receive a tie folded thereover. For some kinds of articles to be displayed, it may be desirable to secure them in place rather than simply drape them over the support arm. For this reason, clip 68 (see FIG. 2) is provided. Clip 68 is resilient and in the form of an inverted U-shaped structure. The arm 62 is provided with a upper notch 70 and a lower notch 72 for cooperation with the clip 68. With the tie in place over the arm, the clip resiliently engages into the notches 70 and 72 to retain the tie in place. In this way, a plurality of ties can be successively draped over serially connected units so that they hang to the same length as shown in FIG. 1. If they were free, such ties would soon move to uneven positions.
As is seen in FIG. 8, a plurality of units, including units 14 and 16, are linked together to form an endless web 12. As is seen in FIG. 9, web 12 is constrained between upper cap 74 and lower cap 76. The caps have drums 78 and 80 pivoted therebetween. Drum 78 is seen in FIGS. 1, 8 and 9, while drum 80 is seen only in dashed lines in FIG. 1. Between the drums, the web lies in a straight line. The web is constrained by guides 82 and 84 on lower cap 76. These guides are on the inside of the straight run of the web between the drums. Similarly, inner guides 86 and 88 extend downwardly from upper cap 74 and correspond to the guides 82 and 84. However, upper cap 74 also carries outer guides 90 and 92 which engage on the outside of the upper edge of the web to prevent it from tilting outward. The web may be driven by hand or may be driven by means of a motor 94 which drives drum 78 through gears 96, 98 and 100. As seen in FIG. 8, the drums have flats thereon which correspond to the central panels on the units. Between the flats on the drums, there are notches such as notch 102 which receive the bars 54 formed of the dog 52 and the adjacent hooks. As is seen in FIG. 8, bar 54 is engaged in notch 102 as the drum rotates and as the web advances. Also as seen in FIG. 8, the article support arms hinge outwardly on their own self-hinges in order to accommodate the overlapping of successive arms and the thickness presented by the articles draped over the arms. For appearance purposes, cover 104 engages over the top of the webs. The cover leaves the web open at the ends so that a selected article may be removed from its support arm. As indicated in FIG. 1, the display system 10 may be supported in any convenient way, such as on a horizontal bar.
This invention has been described in its presently contemplated best mode, and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.
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Each web-forming unit is configured to snap into an identical adjacent unit so that a plurality thereof form a web which flexes at the joints. Each unit has an article-supporting arm thereon upon which a long, narrow item may be hung and displayed. The web is mounted on rotatable drums so that the web may be advanced around the drums to successively bring forward articles supported on the arms.
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FIELD OF THE INVENTION
The present invention relates to a substantially organic solvent free aqueous composition that when applied as a coating to a rubber or polymer substrate such as a vehicle weatherstrip reduces the amount of noise of the substrate upon contact with an article and maintains the initial static coefficient of friction therewith over a period of time.
BACKGROUND OF THE INVENTION
Heretofore, vehicle weatherstrips while providing a barrier to exterior elements such as wind, rain, snow, and sleet, have generally not diminished, and can even contribute to, the interior noise level of the vehicle. Vehicles thus have had an interior noise level often well above 40 dBA.
Vehicle weatherstrips, such as automotive weatherstrips, have been coated for several years, initially with solvent borne urethane systems and more recently with aqueous urethane systems. While such coatings must pass a variety of automotive performance tests (varies depending upon the Original Equipment Manufacturer (OEM), they generally have an undesirable noise level. Moreover, retention of low coefficient of friction (COF) values is generally not maintained because the coating contains various fillers such as waxes or silicones which migrate to the surface of the weatherstrip and eventually are removed and result in an increased coefficient of friction.
Japanese Abstract 61155432 relates to obtaining a coating composition which, when applied to the surface of a polymeric elastomer such as an object, especially, a nonpolar rubber, allegedly improves the adhesion, lubricity, water repellency, resistance to freezing, abrasion resistance, etc., of the elastomer, by using a curable polyurethane, a curable silicone and a tackifier as the principal components of the coating composition.
Japanese Abstract 61155431 relates to obtaining a coating composition, which, when applied to the surface of an nonpolar polymeric elastomer such as EPT rubber, can allegedly improve its adhesion, lubricity, water repellency, abrasion resistance, resistance to freezing, etc., by using curable polyurethane, a polyorganosiloxane composition and a tackifying agent as the principal components of the coating composition.
Japanese Abstract 61138636 relates to providing a composition containing a curable polyurethane composed of a polyvalent isocyanate and a polyol and a curable silicone as the film-forming elements, giving a firm bond by one-coat treatment, and forming a surface allegedly having excellent slipperiness, water-repellency, sound-proofing property and abrasion resistance.
Japanese Abstract 58071233 relates to preventing friction noise and allegedly improve sliding resistance and adhesion by forming a covering fixing coat using a surface treating agent containing polymer with a specific compounding for polyurethane coating material.
U.S. Pat. No. 6,742,784 relates to a weather strip or glass run for an automotive vehicle. The weather strip comprises a main body formed of an elastomer. A slidably contacting section to which a part other than the weather strip is slidably contactable is fixedly formed on the main body and contains a material having at least one of hydrophilicity and water absorbability. The slidably contacting section may be integral with the main body to form a one-piece structure, in which the slidably contacting section is formed of the elastomer, and the elastomer of the main body and the slidably contacting section contain the material having at least one of hydrophilicity and water absorbability.
BRIEF DESCRIPTION OF THE DRAWING
The drawing relates to a cross-sectional view of a typical vehicle weatherstrip having a coating of the present invention thereon.
SUMMARY OF THE INVENTION
An aqueous dispersion composition as a coating for a rubber or a polymer comprises a polymer blend including at least one polysiloxane per se in an amount of from about 50% to about 85% by weight and at least one heat curable polyurethane per se derived from an aliphatic diisocyanate in an amount of from about 15% to about 50% by weight based upon the total weight of all of said polysiloxane and all of said polyurethane polymers. Various fillers such as a high heat resistant high molecular weight polyolefin polymer are incorporated in an amount of from about 5 to about 35 parts by weight based upon the total weight of the polymer solids such as the at least one polysiloxane and the at least one heat curable polyurethane. Other fillers such as various polyamides, silicas, polytetrafluoroethylene, silicone rubber powder and ceramic spheres generally reduce dry noise values, but do not generally reduce wet noise values. The resulting dispersion coating is substantially free of organic solvents and upon application to a polymer or rubber substrate such as an EPDM weatherstrip lowers the interior noise level of a vehicle to less than about 38 dBA. The coatings also provide a low friction surface that, unlike typical coated weatherstrips, will not increase over time.
DETAILED DESCRIPTION OF THE INVENTION
The physical aqueous dispersion coating composition of the present invention contains at least one polysiloxane preferably in the form of an aqueous dispersion having at least one repeat unit having the formula:
wherein R 1 and R 2 , independently, is an alkyl having from 1 to about 4 carbon atoms with a methyl group. Accordingly, (polydimethyl siloxane) is a preferred polysiloxane. The one or more polysiloxanes provide abrasion resistance and reduce coefficient of friction values once the coating has been applied to a substrate and cured. Suitable number average molecular weights generally range from about 100,000 to about 500,000 and desirably from about 200,000 to about 400,000. Such polysiloxanes are known to the art and to the literature and are commercially available and generally have a solid content of from about 20% to about 50% by weight, and desirably from about 25% to about 40% by weight in water.
The polysiloxanes of the present invention are substantially free of amine end groups. That is, generally less than about 10% by weight, desirably less than about 5% by weight, and preferably less than about 2% or about 1% by weight of the total weight of all polysiloxane polymers have an amine group thereon. It is most preferred that the polysiloxane polymers have no amine end group thereon. The total amount of the at least one polysiloxane per se, that is the total polymer(s) itself (100% solids and no water), based upon the total weight of all of the one or more polysiloxanes and all of the one or more polyurethanes per se, that is the total polyurethane polymer(s) (100% solids and no water), is generally from about 50% or about 53% to about 85% by weight, desirably from about 55% to about 80% by weight, and preferably from about 60% to about 75% by weight.
The various one or more polyurethanes preferably in the form of an aqueous dispersion provide structural integrity and durability with regard to weather elements such as wind, rain, sleet, and snow as well as durability with regard to extreme cold and hot temperatures. Such polyurethanes are commercially available and are derived from one or more polyisocyanates and one or more hydroxyl terminated intermediates such as polycarbonate intermediates, polyester intermediates, or polyether intermediates, or combinations thereof, with polycarbonate intermediates being preferred.
The polycarbonates, also referred to as dimer diol carbonates, are known to the art and to the literature and are linked together by carbonate groups, i.e.:
and contain one or more hydrocarbon groups having from about 1 to about 20 carbon atoms, with Bisphenol A being a very common and desired group. Desirably the polycarbonate is prepared from one or more aromatic diols such as bisphenol A, tetrabromo bisphenol A, tetramethyl bisphenol A, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 3,3-bis(para-hydroxyphenyl) phthalide, or bishydroxyphenylfluorene. The polycarbonates can be prepared from raw materials by any of several known processes such as interfacial, solution or melt processes. As is well known, suitable chain terminators and/or branching agents can be employed to obtain the desired molecular weights and branching degrees. The polycarbonate can be derived from two or more different aromatic diols, or an aromatic diol and a glycol, or a hydroxyl- or acid-terminated polyester, or a dibasic acid in the event a polycarbonate copolymer or heteropolymer is desired rather than a homopolymer.
The polyether intermediates are well known to the art and to the literature and generally have the repeat unit —R—O— wherein R is an alkylene group having from 1 to 6 carbon atoms with 2 or 3 carbon atoms, that is ethylene or propylene being preferred. Examples of water-borne polyurethane dispersions and processes for the preparation thereof are known to the art and to the literature, and the same are described in U.S. Pat. Nos. 5,312,865; 5,555,686; 5,696,291; 4,876,302; and 4,567,228, hereby fully incorporated by reference. Generally, hydrophilic polyether urethanes can be prepared using a polyether polyol having at least two, preferably three, hydroxyl groups, and a number average molecular weight in the range of from 2,000 to about 20,000, desirably about 2,000 to about 5,000, and preferably about 4,000 to about 5,000, and having random ethylene oxide units in a mole ratio of ethylene oxide (EO) to higher alkylene oxide of 1:1 to 4:1. The alkylene oxide can be selected from propylene oxide (PO), butylene oxide, pentylene oxide, hexylene oxide, trimethylene oxide, tetramethylene oxide, and mixtures thereof. The hydrophilic polyol is preferably a polyoxyethylene-propylene polyol comprising, for example, about 50% to about 70% EO and about 30% to about 50% PO. A particularly preferred polyether triol is one comprising approximately 68% EO and approximately 32% PO. Alternate ratios of EO:PO can be used in preparing the hydrophilic polyol provided that the hydrophilicity of the resulting polyol is not significantly adversely affected. These ratios can be determined by routine testing.
The various hydroxyl terminated polyesters include the linkage of the formula:
are generally made by the reaction of a dicarboxylic acid or an anhydride thereof having from about 2 to about 10 or about 20 carbon atoms with a diol having from about 2 to about 20 carbon atoms, with from about 2 to about 6 or about 8 carbon atoms being preferred. Examples of dicarboxylic acids and anhydrides include maleic acid, maleic anhydride, succinic acid, glutaric acid, glutaric anhydride, adipic acid, suberic acid, pimelic acid, azelaic acid, sebacic acid, chlorendic acid, 1,2,4-butane-tricarboxylic acid, phthalic acid, the isomers of phthalic acid, phthalic anhydride, fumaric acid, dimeric fatty acids such as oleic acid, and the like, and mixtures thereof. Examples of diols include various alkylene glycols, e.g., ethylene glycol, 1,2- and 1,3-propylene glycols, 1,2-, 1,3-, 1,4-, and 2,3-butylene glycols, hexane diols, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, and other glycols such as bisphenol-A, cyclohexane diol, cyclohexane dimethanol (1,4-bis-hydroxymethylcycohexane), 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, caprolactone diol, dimerate diol, hydroxylated bisphenols, halogenated diols, and the like, and mixtures thereof. Preferred diols generally include ethylene glycol, propylene glycol, butylene glycol, and hexane diol. Such polyester polyols are well known to the art and to the literature.
The hydroxyl terminated polyurethane intermediates of the present invention can also contain other hydrophilic groups in order to improve the dispersion of the polyurethane in water. Such hydrophilic groups are generally pendant from the backbone chain and include hydroxyl groups, carboxyl groups, and the like and can be crosslinked and result in cure of the urethane. Examples of hydroxyl groups are well known and include the glycols set forth hereinabove with regard to the formation of the polyester intermediate which are hereby fully incorporated by reference. Examples of carboxyl groups are also known to the art and to the literature and can include hydroxy-carboxylic acids having the general formula (HO) x Q(COOH) y′ , wherein Q is a straight or branched hydrocarbon radical containing 1 to 12 carbon atoms, and x and y, independently, are 1 to 3. Examples of such hydroxy-carboxylic acids include, but are not limited to, citric acid, dimethylolpropanoic acid (DMPA), dimethylol butanoic acid (DMBA), glycolic acid, lactic acid, malic acid, dihydroxymalic acid, dihydroxytartaric acid, and the like, and mixtures thereof.
The various isocyanates that are reacted with the one or more hydroxyl terminated intermediates are preferably an aliphatic or a cycloaliphatic diisocyanate to impart good weatherability to the polyurethane. Examples of such suitable diisocyanates having from 4 to about 20 carbon atoms include dicyclohexylmethane 4,4′-diisocyanate (H12MDI) 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (isophorone diisocyanate) or IPDI), tetramethylene diisocyanate, 1,3-bis(isocyanatomethyl) cyclohexane, hexamethylene diisocyanate (HDI), and dodecamethylene diisocyanate. Of course, if a tri- or a tetra-isocyanate is utilized, it will result in crosslinking of the polyurethane.
The formation of the polyurethanes utilized in the present invention are well known to the art and to the literature and are commercially available as is the preparation thereof. Thus, reaction is usually carried out in an organic solvent such as methyl ethyl ketone, or n-methyl pyrrolidone, and the like. Neutralizing agents are desirably added to render the polyurethane more water compatible. Neutralizing agents include amines such as N-methyl morpholine, triethylamine, dimethyl ethanolamine, methyl diethanolamine, morpholine dimethyl isopropanolamine, 2-amino-2-methyl-1-propanol, and the like, and mixtures thereof. Chain extension is usually desired and while various diols can be utilized, diamines having a total of from about 2 to about 20 carbon atoms are desired. Examples include ethylendiamine, 1,6-diaminohexane, piperazine, tris(2-aminoethyl)amine and amine tertinated polyethers, and mixtures thereof, and the like. Water is generally added after neutralization. Subsequently, the organic solvent can be removed through various known techniques such as evaporation, utilization of extraction techniques, and the like with the result being a high molecular weight aqueous polyurethane.
The number average molecular weight of polyurethanes of the present invention generally range from about 50,000 to about 500,000 with about 150,000 to about 400,000 being preferred. The amount of urethane solids in water is generally from about 20% to about 50% by weight and desirably from about 25% to about 40% by weight. The polycarbonate based polyurethanes are preferred.
The amount of the one or more polyurethanes, per se, that is the total polymer(s) (100% solids and no water) utilized in the aqueous dispersion compositions of the present invention is generally from about 15% to about 50% by weight, desirably from about 20% to about 45% by weight, and preferably from about 25% to about 40% by weight based upon the total weight of all of the polymers, that is the one or more polysiloxane solids, and the one or more polyurethanes.
While various additives may contain some organic solvent, the total amount of any one or more organic solvents is low, that is generally less than about 7% by weight, desirably less than about 5% by weight and preferably less than about 2% by weight based upon the total weight of the aqueous dispersion composition including the various additives therein. The aqueous dispersion compositions of the present invention are thus environmentally friendly and yet provide low noise and low coefficients of friction when applied to a rubber or polymer substrate.
The polyurethanes of the present invention can be crosslinked after the aqueous dispersion composition has been applied to a substrate. By crosslinking or curing it is meant that an individual polyurethane chain is chemically bound to at least one, preferably at least two other different polyurethane chains at a point other than their terminus. A preferred crosslinking mechanism of the present invention is through one or more pendant carboxylic acid groups of the polyurethane. Suitable crosslinking agents include various carbodiimides that are known to the art and to the literature. Alternatively, various aziridines can be utilized which have two or more aziridine groups thereon such as trimethylolpropane-tris-(B—(N-Aziridinyl)Propionate), and Pentaerythritol-tris-(B—(N-Aziridinyl)Propionate). Carbodiimide and polyaziridine crosslinking agents are desired and are curable at temperatures from about 50° C. to about 200° C. and desirably from about 80° C. to about 190° C. in relatively short periods of time as from about 2 to about 30 minutes. Naturally, the crosslinking reaction should not be carried out until the aqueous dispersion composition has been applied to an end substrate. The amount of crosslinker generally ranges from about 0.5% to about 10% and desirably from about 1% to about 5% by weight based upon the total weight of the polysiloxane-polyurethane dispersion composition.
An important aspect of the present invention is the utilization of one or more polyolefins and preferably polyethylenes such as powdered crystalline high temperature resistant polyethylenes since they lower both the dry and wet noise level when applied to a vehicle seal such as an automobile weatherstrip. Such polyethylenes are commercially available and thus known to the art and to the literature. The amount of the polyolefins such as the noted polyethylene generally ranges from about 5 or about 8 to about 35 parts by weight and desirably from about 10 or about 15 to about 25 or about 30 parts by weight per 100 parts by weight of the one or more polysiloxanes per se and one or more polyurethanes, per se, that is free of water and solvents. The weight average molecular weight of the preferred polyethylene is generally very high and ranges from about 2 million to about 5 million and desirably from about 3 million to about 4 million and thus can be classified as an ultra high molecular weight polyethylene. The size of the polyethylene powder can vary with a mean or average particle diameter of from about 20 to about 50 microns.
Various additives such as fillers, ceramic spheres, gloss control agents, pigments, rheology modifiers, wetting agents, and the like can be used to impart various properties to the aqueous dispersion coating composition and/or the cured coating thereof.
Fillers are utilized to lower costs and often to lower COF and noise. Desirably the fillers are various polymers such as nylon, polytetrafluoroethylene, polyolefins, and silicone rubber powder. These fillers aid in reducing the coefficient of friction of the dried aqueous dispersion coatings of the present invention. However, with regard to noise reduction, they generally only show improved results with regard to dry noise properties.
Halogenated polymers are avoided because they have generally been found not to reduce noise levels, either wet or dry, and are usually expensive. Such polymers include polyvinyl chloride, and various fluorocarbon polymer such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, and polychlorotrifluoroethylene. If utilized, the amounts thereof are small such as generally less than about 10 parts by weight, desirably less than about 5 parts by weight, preferably less than 2 or 1 part by weight, and preferably nil, that is no parts by weight per 100 total parts by weight of the one or more polysiloxanes per se and the one or more polyurethanes per se.
Another class of compounds that are avoided are various tackifiers since they generally destroy low coefficient of friction values, are sticky and do not give quick release with respect to metals, plastics, and the like, and pick up dust and dirt. Examples of avoided tackifiers include various aromatic and aliphatic hydrocarbon resins, various rosins such as tall oil rosins and esters of rosins, pine tar, various phenolic resins, various alkylphenol formaldehydes, and the like. Any amount thereof utilized is very small such as generally less than about 10 or less than about 5 parts by weight, desirably less than about 2 parts by weight and preferably 1 part or less, or nil, that is no parts by weight based on 100 total parts by weight of the one or more polysiloxanes per se, and the one or more polyurethanes per se.
Another class of fillers includes ceramic spheres which are generally utilized as an extender and the same are known to the art and to the literature. Suitable spheres include ceramic beads that have an average diameter of from about 1 to about 12 microns. The amount thereof is generally from about 10 or about 20 to about 35 or about 40 parts by weight per 100 parts by weight of said one or more polysiloxanes per se and said one or more polyurethanes per se.
Various gloss control agents in amounts from about 2 or about 4 parts to about 7 or about 9 parts by weight per 100 parts by weight of the one or more polysiloxanes per se and the one or more polyurethanes per se can be utilized to lower the gloss of the cured coating. A suitable gloss control agent are known to the art and to the literature such as various synthetic wax coated silicas.
It is often desired to use various pigments so that the applied coating can generally match the color of the polymer substrate. Since weatherstrip seals are often black, various black pigment dispersions can be utilized the majority of which are various carbon blacks that are well known to the art and to the literature. The amount of such pigments can vary as from about 0.1 to about 5.0 parts by weight per 100 parts by weight of the one or more polysiloxanes per se and the one or more polyurethanes per se.
In order to keep the aqueous dispersion coating composition from dripping, pooling, sagging or running when applied to a substrate and also to keep the polymer particles dispersed in water, a rheology modifier or thickener is often utilized. Numerous types of commercially available thickeners can be utilized in amounts of from about 0.5 or 1.5 to about 2.5 or about 3 parts by weight per 100 parts by weight of the one or more polysiloxanes per se and the one or more polyurethanes per se. Thickeners include various rheology modifiers such as a urethane based associative thickener.
Rheological additives also include numerous wetting agents with fluorinated anionic surfactants generally being desired. Depending upon the specific formulations of the aqueous dispersion coating composition, the amounts can vary greatly such as from about 0.05 to about 0.5 parts by weight per 100 parts by weight of the one or more polysiloxanes per se and the one or more polyurethanes, per se.
The aqueous dispersion composition of the present invention is made by adding the polysiloxane aqueous dispersion as well as the polyurethane aqueous dispersion together and mixing. Subsequently, the gloss control agent can be added and blended under shear. Then the remaining components can be added either separately or all together, mixed and stored until needed. Before application to a substrate, in any conventional manner such as dipping or brushing, with spraying being preferred, a crosslinking agent is optionally added in an amount of from about 1% to about 5% by weight based upon the total weight of the aqueous dispersion coating.
The substrates can be any rubber or polymer to which a low coefficient of friction coating is applied, and/or to a substrate that has an end use where it is desired to emit a low level of noise upon contact with an article such as generally about 42 dBA or less, desirably about 40 dBA or less, and preferably about 38 dBA or less, and more preferably 36 dBA or less. In addition to the present invention obtaining good low noise values, with regard to both wet and dry conditions, an important aspect is that good stability values are obtained. That is, when the formulations of the present invention are applied to a weatherstrip substrate, the coefficient of friction with regard to time does not increase but surprisingly and unexpectedly decreases. Initial static coefficient of friction values of the compositions of the present invention according to ASTM Test D-1894-95 are generally very low such as about 0.40 or less, desirably about 0.35 or less, and preferably 0.32 or less. Such values actually decrease with time and an important aspect of the present invention is that upon aging the composition of the present invention have a lower static coefficient of friction after 12 weeks, 16 weeks, 20 weeks, 28 weeks, and even after 40 weeks which is lower than the initial value. This is very unusual inasmuch as heretofore, prior art coatings would invariably increase. Similarly, the kinetic coefficient of friction values dropped with time and took several months according to ASTM Test D-1894-95 before they rose to the initial value. Thus, both the static test and the kinetic test show that coefficient of friction values are stabilized with time whereas with prior art coats, increases with time were always generally obtained. The various substrates can be fully coated upon all surfaces thereof but generally are only partially coated as upon a surface which would bear against painted metal or plastic and/or require a low coefficient of friction engagement. Substrates include various rubbers, i.e. elastomers, such as, but not limited to, those derived from natural rubber, butadiene, isoprene, butadiene and styrene, as well as ethylene-propylene-diene rubber. Polymer substrates include, but are not limited to, the various acrylics, various vinyl or vinylidene polymers such as polyvinyl chloride and polystyrene, various types of polyamides, various types of polyesters, various types of polyurethanes, various types of polyolefins, various types of thermoplastic olefins, and various types of thermoplastic elastomers or vulcanizates such as thermoplastic polyurethanes. A preferred end use of a composition is to coat a vehicle weatherstrip to lessen the noise generally created by vibration thereof as against a metal or plastic article or part. Vehicles include various types of trucks such as pickup trucks, vans, sport utility vehicles, automobiles, and the like. Weatherstrips include any weatherstrips used on a vehicle and especially weatherstrips for use on doors, windows, hoods, and trunk lid seals.
Referring to the drawing, weatherstrip 10 generally made from EPDM contains body fastening portion 12 which is affixed to a vehicle part such as door flange. EPDM sponge bulb 16 can engage or contact a body portion of a vehicle such as a door frame to create a weatherseal therewith. The aqueous coating composition 18 of the present invention is applied to the sponge bulb 16 which will contact the body of the vehicle.
The invention will be better understood by reference to the following examples which serve to illustrate, but not to limit the present invention.
The aqueous dispersion coatings of the present invention are environmentally friendly inasmuch as they are water based compositions and contain very low amounts of solvents, if any. They exhibit low term coefficient of friction values as well as low noise values when utilized as a weatherstrip on a vehicle.
The coated rubber weatherstrip was tested with accordance with a General Motors test, i.e. GM9842P Rev A. The test description is duplicated as follows:
GM Engineering Standards, Test Method, GM9842P, Rev A.
1. Scope
This specification describes a test to evaluate and rank the acoustic output of 2 similar or dissimilar materials in dynamic contact.
Note: Nothing in the specification, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.
Note: In the event of a conflict between the English and the domestic language, the English language shall take precedence.
2. References
Note: Only the latest approved standards are applicable unless otherwise specified.
2.1 Normative.
Not Applicable.
2.2 GM.
GM9840P GM9842P
3 Test Equipment
3.1 Sound Isolation. A semi-anechoic chamber capable of reducing the interior ambient sound pressure to a level of 30 dB(A) maximum (vibration system operating with the fixture). Additionally, the chamber shall permit the conditioning of the air to the specified temperature and humidity limits (Section 5.1).
3.2 Vibration System. A vibration system capable of the sine and random specification (Section 5.3). The vibration system chosen will normally be of the electro-dynamic type but may include other types capable of low noise generation so as to minimize the interference of acoustic measurements of the parts under test.
3.3 Measurement System. A calibrated ANSI Type 1 microphone and sound data acquisition system (SDAS) capable to yielding A weighted stable average Sound Pressure levels (SPL) and ⅓ octave band frequency domain charts across the 20 Hz to 20 kHz frequency range. The system should additionally provide the capability for recording the sound output of the parts under test to a digital file for audio playback at later date.
3.4 Fixtures. Fixturing systems should enable close approximation of materials, deflection and fit of the vehicle components.
4 Test Material
4.1 Test Specimens. Three specimens must be tested. Specimens shall be individual pieces or cut sections of rubber, plastic, or substrate 150 mm in length or mutually acceptable and appropriate to component use. Mating surface should, where possible, approximate the profile and surface in actual use to accommodate the probable displacement or interference force of the specimens.
5 Test Method
5.1 Standard Test Conditions. Unless otherwise specified, the standard test environment shall be 21±1° C. and 75±5% relative humidity. Unless otherwise specified, the standard test surface shall be DuPont RK8010A Clearcoat. The compression height must be specified at the time of part submittal and must be derived from the nominal value on the part drawing.
5.2 Calibration and Ambient Noise Record. Prior to any measurements, the microphone and sound data acquisition system must be calibrated with an NIST traceable 1 kHz tone calibrator. The calibration tone points of 94 dB amplitude and 104 dB amplitude shall be used. These results must be entered on the report form. Adjust the microphone to the test interface distance of 150 mm. This distance shall remain constant for the duration of these tests and must be documented in the test report. Prior to test sample contact, start the vibration system with the specified sine or random vibration profile and record the ambient noise for 10 seconds. This value must not exceed 30 dB(A) and must be documented on the report form. This must be performed prior to each test session, or where vibration parameters are changed. The ambient noise spectrum shall become part of the report.
5.3 Vibration Profiles. The following tables (Tables 1 and 2) specify both sine and random vibration profiles for sample testing.
TABLE 1
Random Vibration Profile
Frequency
PSD (g 2 /Hz)
Displacement (pk-pk)
5 Hz
.0065
.308 inches (7.82 mm)
12.5 Hz
.063
.242 inches (6.14 mm)
20 Hz
.0995
.151 inches (3.83 mm)
32.5 Hz
.1480
.089 inches (2.26 mm)
50 Hz
.036
.023 inches (0.58 mm)
PSD (Power Spectral Density
Total G(RMS) = 1.945
TABLE 2 Sine Vibration Profiles Frequency Displacement (pk-pk) Substrate 9 Hz 0.2 inches (5 mm) Elastomer (<65 Shore A) 9 Hz 0.04 inches (1 mm) Plastic (≧65 Shore A)
Each of the two above sine profiles is specific to the hardness of the compound formulation.
5.4 Sample Preparation. All surfaces shall be clean and free of dirt or oils. All test samples or parts shall be cleaned with water, followed by drying at ambient temperature for a 12 hour period. Glass, paint or metal surfaces shall be cleaned with isopropyl alcohol prior to test unless otherwise agreed upon.
5.5 Dry Interface Test. Start the sound analysis system and the vibration mechanism and record output for 10 seconds as a digital frequency domain file. Repeat twice for a minimum of three readings. Interval between readings shall be 2 minutes. Reading shall be taken at initiation of vibration, at 2 minutes from start, and at 4 minutes from start. If noise data is unstable, the test duration may be extended. Repeat for a total of three part samples, with three measurements for each sample.
5.6 Wet Interface Test. With pipette, add 2±0.25 mL of distilled water to the interface. Record output as described in Section 5.5.
(Option) Long Term Durability Test. Optionally, the test sample may be permitted to vibrate in the dry interface mode for an extended number of cycles or period of time to assess the long-term acoustic properties.
6 Evaluation and Rating
6.1 The results shall be reported as calculated values from the mean of 3 (initial, two minutes, four minute) stable average amplitude readings in dB(A) (relative to 20 micropascal base).
6.2 The test in GM9842P result in a total of twelve values (four random-dry, four random-wet, four sine-dry and four sine-wet) for each of the three submitted weatherstrip specimens.
TEST REPORTING MATRIX
CONDITIONS
Random/Dry
Random/Wet
Sine/Dry
Sine/Wet
Sample #1
READINGS
Initial Reading
Initial Reading
Initial Reading
Initial Reading
2-min Reading
2-min Reading
2-min Reading
2-min Reading
4-min Reading
4-min Reading
4-min Reading
4-min Reading
VALUES
Mean
Mean
Mean
Mean
Sample #2
READINGS
Initial Reading
Initial Reading
Initial Reading
Initial Reading
2-min Reading
2-min Reading
2-min Reading
2-min Reading
4-min Reading
4-min Reading
4-min Reading
4-min Reading
VALUES
Mean
Mean
Mean
Mean
Sample #3
READINGS
Initial Reading
Initial Reading
Initial Reading
Initial Reading
2-min Reading
2-min Reading
2-min Reading
2-min Reading
4-min Reading
4-min Reading
4-min Reading
4-min Reading
VALUES
Mean
Mean
Mean
Mean
Any mean value exceeding 40 dBA will be considered unacceptable.
6.3 Values greater than 40 dB(A) will be considered unacceptable.
7 Report
The following information must be reported: The test lab must provide frequency domain spectra with a minimum resolution of ⅓ octabe across the frequency span. The finished report shall further document the test sample environment including the ambient noise measurement, temperature and relative humidity conditions, and a copy of the NIST calibration certificate. Parameters applied to the sample, such as counter surface, vibration frequency, stroke length, degree of deflection or normal force load, duration of test, and condition of the interface between the sample and mating surface (dry, wet, etc.) must be reported.
8 Approved Sources
Engineering qualification of an approved source is required for this specification. Only sources listed in the GM Corporate Materials File under this specification number have been qualified by engineering as meeting the requirements of this specification. Sources are available through the on-line MATSPC System.
9 Safety
This method may involve hazardous materials, operations and equipment. This method does not propose to address all the safety problems associated with its use. It is the responsibility of user of this method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
9 Coding System
This test procedure shall be called up in other documents, drawings, VTS, CTS, etc. as follows: “Test to GM9842P”
10 Release and Revisions
10.1 Release. This standard was developed with the cooperation of Custom Acoustic Research and Environmental Screening Test Laboratories (ESTL). The standard was originated by the Weatherstrip Specialist Team in December 1997 and first published in September 1998.
10.2 Revisions.
Originating
Organization/
Rev.
Date
Description/Reason
Committee
A
December
Changed specification number
Weatherstrip
1998
form GM9840P to GM9842P.
Specialist Team
Number incorrectly assigned.
Moved from General Book to
Procedures Book
B
January
Changed format; changed
Weatherstrip
2002
Background limit to 30 dB(A);
Specialist Team
added standard test
conditions; added seal
deflection requirements;
added test reporting matrix
EXAMPLE A
Formulation A relates to an aqueous dispersion coating of the present invention which produces low wet and dry noise levels when applied to an EPDM weatherstrip substrate. The weatherstrip utilized in all of the Examples is described as a typical sculptured sponge bulb primary door seal which contains a typical EPDM composition as shown in the drawing.
FORMULATION A
%
Total Parts
Solids
by Weight
Aqueous Polyurethane - polycarbonate based
39%
17.21
Ultra High Molecular Weight Polyethylene
100%
4.00
Powder (filler)
Ceramic Beads (fillers) average diameter
100%
6.40
1-12 microns
Synthetic Wax Coated Silica (gloss control
100%
1.14
agent)
Silicone Resin - aqueous dispersion
35%
40.15
Pigment - carbon black dispersion
30%
1.93
Water (DI)
0%
26.86
Rheological Additives
21%
2.31
Total Weight
100.00
The polyurethane dispersion and the polysiloxane or silicone resin dispersion were added to a vessel and mixed along with approximately one half by weight of the wetting agent for approximately 15 minutes. The silica gloss control agent was then added and mixed under moderate shear using an air-powered Hochmeyer blade for approximately 15 minutes. Subsequently, the remaining ingredients were added in any order and blended while mixing. Once all the various components were added, the mixture was further mixed for approximately 20 minutes, then filtered and packaged for storage. Prior to use, approximately 3% by weight of a carbodiimide crosslinking agent was added with mixing. Crosslinking agents were also utilized in all of the following examples. The mixed coating composition was then applied using a Turbo spray or a HVLP spray gun to the EPDM substrate. Typical application viscosities ranged between 20 to about 50 seconds on a Zahn #3 cup. The total solids content of the coating composition generally ranged from about 30% to about 35% by weight and the dry coating or film thickness was from about 0.2 to about 0.6 mil.
The coated substrate was then tested in accordance with GM Test Method GM9842P, Rev A. The following data was obtained as set forth in Table 1.
TABLE 1
(dBA)
(dBA)
(dBA)
(dBA)
Composition
Random Dry
Random Wet
Sine Dry
Sine Wet
Formulation A
35
38
26
27
As apparent from the above data, good low dBA values were obtained with regard to random wet and dry test and very good data was obtained to the wet and dry sine test.
EXAMPLES B, C, D, AND E
The formulation for additional aqueous dispersion coatings of the present invention are set forth as follows:
FORMULATIONS B, C, D, AND E
FORMULATIONS
(total parts by weight)
Ingredient
% Solids
B
C
D
E
Aqueous Polyurethane -
39%
16.64
16.64
16.64
16.64
polycarbonate based
Ultra High Molecular Weight
100%
3.87
3.87
3.87
3.87
Polyethylene Powder (filler)
Ceramic Beads (fillers)
100%
6.19
6.19
6.19
6.19
average diameter 1-12 microns
Synthetic Wax Coated Silica
100%
1.10
1.10
1.10
1.10
(gloss control agent)
Silicone Resin - aqueous
(35%)
(35%)
(50%)
(40%)
dispersion (% solids)
38.82
38.82
27.18
33.98
Pigment - carbon black
30%
1.87
1.87
1.87
1.87
dispersion
Water (DI)
0%
29.67
29.67
41.31
34.51
Rheological Additives
21%
1.84
1.84
1.84
1.84
Formulations B through E were prepared in a manner as set forth with regard to Example A and tested with respect to the same GM test on the same type of weatherstrip substrate. The results are set forth in Table 2.
TABLE 2
(dBA)
(dBA)
(dBA)
(dBA)
Formulation
Dry, Random
Wet, Random
Dry, Sine
Wet, Sine
B
33.0
36.6
25.4
27.1
C
33.7
36.3
27.2
27.3
D
31.4
35.0
26.1
27.8
E
33.3
37.8
25.6
26.8
As apparent from the above, very good low dBA readings were obtained with regard to both the wet and dry sine test as well as the wet and dry random test.
By way of comparison with respect to Tables 1 and 2, Table 3 sets forth data obtained utilizing the same GM test and EPDM weatherstrip substrate as set forth above. Lord Corporation Products #1, #2, and #3 were utilized as controls and were tested with regard to noise levels.
TABLE 3
(dBA)
(dBA)
(dBA)
(dBA)
Coating
Random Dry
Random Wet
Sine Dry
Sine Wet
Lord Product #1
50
65
41
63
Lord Product #2
34
55
28
50
Lord Product #3
30
62
25
61
As apparent from Table 3, very high dBA values were obtained with regard to both random wet as well as the wet sine tests. In comparison, the data set forth above with regard to Formulations A through E unexpectedly achieved much lower values, that were in some cases greater than 50% lower.
EXAMPLES F AND G
Formulations F and G are similar to Formula A except that generally a different polysiloxane was utilized in Formulation F as well as in Formulation G and the Formulation G additionally contained about 3 parts by weight of polyethylene.
FORMULATION F and G
Formulation F
Formulation G
Percent
Total Parts
Total Parts
Ingredient
Solids
by Weight
by Weight
Aqueous Polyurethane -
39%
16.64
13.21
polycarbonate based
Ultra High Molecular Weight
100%
3.87
2.93
Polyethylene Powder (filler)
Ceramic Beads (fillers)
100%
6.19
6.30
average diameter 1-12
microns
Synthetic Wax Coated Silica
100%
1.10
—
(gloss control agent)
Silicone Resin - aqueous
50%
27.18
—
dispersion
40%
—
39.69
Pigment - carbon black
30%
1.87
1.90
dispersion
Water (DI)
0%
41.31
25.55
Rheological Additives
21%
1.84
1.87
m-pyrrolidone
0%
—
8.55
Three commercial products were also tested at the same time, that is Competitive Products #1, and #2, as well as Lord Product #3.
TABLE 4
(dBA)
(dBA)
(dBA)
(dBA)
Coating
Dry Random
Wet Random
Dry Sine
Wet Sine
Formulation F
30.4
30.6
24.9
24.2
Formulation G
31.5
35.1
24.2
26.7
Competitive
34.1
42.7
27.0
40.6
Product #1
Competitive
37.8
47.1
29.2
40.4
Product #2
Lord Product #3
27.6
57.2
23.5
57.1
As apparent from Table 4, Formulations F and G of the present invention gave excellent low noise values even with regard to the wet random values and wet sine test values whereas the commercial products gave very high noise values.
EXAMPLES H, I, J, AND K
Further formulations with regard to coatings for weatherstrips are set forth as follows.
Formulations H, I, J, and K
% Silicone resin
%
47%
57%
66%
75%
Solids
H
I
J
K
Aqueous Polyurethane -
39%
28.21
23.21
18.21
13.21
polycarbonate based
Ultra High Molecular Weight
100%
2.93
2.93
2.93
2.93
Polyethylene Powder (filler)
Ceramic Beads (fillers)
100%
6.30
6.30
6.30
6.30
average diameter 1-12 microns
Silicone Resin - aqueous
40%
24.69
29.69
34.69
39.69
dispersion
Pigment - carbon black
30%
1.90
1.90
1.90
1.90
dispersion
Water (DI)
0%
25.55
25.55
25.55
25.55
m-pyrrolidone
0%
8.55
8.55
8.55
8.55
Rheological Additives
21%
1.87
1.87
1.87
1.87
Total
100.00
100.00
100.00
100.00
Formulations H, I, J, and K were prepared in a manner as set forth with regard to Example A and tested with respect to the same GM test on the same types of substrates as set forth in Example A. The noise results are set forth in Table 5.
TABLE 5
FORMULATIONS
Noise (dBA)
H
I
J
K
Random Wet
40.7
36.7
36.6
35.9
Sine Wet
26.8
25.9
26.7
27.0
Random Dry
34.1
33.1
31.7
32.3
Sine Dry
24.8
25.2
24.6
24.8
As apparent from Table 5, once again very low dBA noise levels were obtained in the various tests. Moreover, with regard to the wet tests, and especially the random wet test, with the exception of Formulation H, values below 38 dBA were readily obtained. Example H demonstrates that generally high amounts of silicone resin, i.e. in excess of 50% by weight, and in combination with about 3 wt % of PE powder are generally desired in order to obtain good random wet properties.
EXAMPLES L, M, AND N
The aqueous dispersion compositions of the present invention were also tested with regard to long term retention of static and dynamic coefficient of friction properties. Formulations with regard to such aqueous dispersion compositions are set forth in Formulations L, M, and N wherein different fillers have been utilized and yet good low dBA were obtained as well as good stability values.
Formulations L, M, and N
%
FORMULATION
Solids
L
M
N
Aqueous Polyurethane -
39%
28.68
28.68
17.21
polycarbonate based
Ultra High Molecular
100%
2.98
2.98
2.98
Weight Polyethylene
Powder (filler)
Ceramic Beads (fillers)
100%
6.40
6.40
6.40
average diameter
1-12 microns
Fluorinated Polymer
50%
—
2.98
—
Dispersion
Silicone Resin -
35%
28.68
28.68
40.15
aqueous dispersion
Pigment - carbon
30%
1.93
1.93
1.93
black dispersion
Water (DI)
0%
30.69
30.69
30.69
Rheological Additives
21%
2.31
2.31
2.31
Total
101.67
104.65
101.67
After the above ingredients were mixed to form the noted formulations and just prior to application to an EPDM weatherstrip substrate in accordance with GM 9842P, Rev. A, 3% weight based upon the total weight of the formulation of the above-noted crosslinking agent is added and mixed.
Test values with regard to noise level, gloss, and coefficient of friction are set forth in Table 6.
TABLE 6
FORMULATION
L
M
N
Dry Sine (dBA)
24.4
23.9
24.7
Wet Sine (dBA)
27.8
27.4
28.4
Dry Random (dBA)
30.7
28.6
32.9
Wet Random (dBA)
35.0
34.6
35.4
As apparent from the data, once again excellent low noise dBA were obtained including the wet random test.
Formulations L and N were tested in accordance with ASTM Test D1894-95 with regard to static coefficient of friction as a function of time. The results were as follows.
TABLE 7
Formulation L
Formulation N
Time/Weeks
Static
Kinetic
Static
Kinetic
0
0.325
0.236
0.298
0.216
4
0.243
0.156
0.202
0.145
8
0.193
0.126
0.221
0.134
12
0.212
0.170
0.179
0.152
16
0.291
0.257
0.267
0.217
20
0.279
0.228
0.229
0.182
28
0.266
0.244
0.244
0.200
40
0.330
0.269
0.248
0.227
As apparent from the above, the standard coefficient of friction with time at the various indicated week periods was always lower than the initial coefficient of friction. Consistent COF is important over time to maintain good ice release and low dirt pick-up on the door seal.
While in accordance with the patent statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.
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An aqueous dispersion coating for rubber and polymer substrates comprises a blend of a polysiloxane and a curable polyurethane and various additives such as a urethane crosslinking agent, a heat resistant filler, and the like. The aqueous dispersion coating reduces the noise upon contact or movement of the coated substrate with an article and maintains the initial static coefficient of friction therewith over a period of time. A desired end use is as a coating on vehicle weatherstrips such as for doors, trunks, and other enclosing articles.
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RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. application Ser. No. 10/606,655, filed Jun. 26, 2003, which is a continuation-in-part of U.S. application Ser. No. 09/332,518, filed Jun. 14, 1999, which claims the benefit of U.S. Provisional Application No. 60/130,445, filed Apr. 21, 1999. The entire teachings of the above applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to wireless local area network systems and more particularly to a distribution network for coupling wireless local area network signals between centrally located internetworking devices and remotely located access points.
[0003] The most common user applications for personal computers now require a connection to a computer network of some type. Such applications include the viewing of e-mail, sharing of data files, and accessing the Internet and the World Wide Web. Various techniques are used for connecting computers together so that they may send data to and receive data from each other, more or less in real time. Most often this so-called physical layer is implemented using wires and the bits of data to be exchanged are converted into electrical signals that move through the wires. Traditionally, local area networks (LANs) were implemented using privately installed wiring, such as coaxial cable or twisted pair type cable and network adapter circuits. Later, it became possible to construct LANs through the use of the public switched telephone network and modem equipment.
[0004] However, networks that use infrared light or radio frequency energy at the physical layer are growing in popularity. These so-called wireless local area networks (“wireless LANs”) convert the bits of data into radio waves to enable their transmission over the air, which in turn minimizes the need for hard wired connections.
[0005] Wireless LANs have tended to find application where user mobility and portability is important, such as in the healthcare, retail, manufacturing, and warehousing industries. This limited use has no doubt been the result of the added cost of the required wireless network adapters. However, they are also becoming more widely recognized as a general purpose alternative for a broad range of business applications as the cost of mobile computing equipment such as laptop computers and personal digital assistants (PDAs) continues to decrease. With a wireless LAN, users can access shared information without first stopping to find a place to plug-in their equipment. In addition, network managers can set up or augment such networks without installing or moving wires around from place to place.
[0006] The simplest wireless LAN configuration is an independent type network that connects a set of computers with wireless adapters. Anytime any two or more of the wireless adapters are within radio range of one another, they can set up a network. More common is a type of multi-user LAN wherein multiple devices referred to as access points collect signals at a central location. The access points collect signals transmitted from personal computers equipped with wireless network adapters, and distribute them over wire physical media to other internetworking devices such as repeaters (hubs), bridges, routers, and gateways, to provide interconnectivity to larger networks.
[0007] The range of a wireless LAN is limited by how far the signals can travel over the air between the access points and the network adapters connected to the PCs. Currently, the Institute of Electrical and Electronic Engineers (IEEE) 802.11 wireless LAN standard, which is the most widely used, specifies power output levels which carry signals over a few hundred feet.
[0008] To extend coverage beyond this limited range, a network of access points with overlapping radio ranges must be located throughout the desired coverage area. These so-called infrastructure wireless LANs are implemented in a manner which is similar to a cellular telephone system. At any given time, a mobile personal computer equipped with a wireless LAN adapter communicates with a single access point within the current microcell within which it is located. On the landline side, the access points are interconnected using network-compatible twisted pair wiring such as that which is compliant with the Ethernet/802.3 10 baseT or 100 baseT standard. The network signals can then be further forwarded to a local- or wide-area network using standard internetworking protocols and devices.
SUMMARY OF THE INVENTION
[0009] The present invention provides a simple and low cost architecture for coupling wireless local area network (“wireless LAN”) signals between geographically distributed access points and centrally located internetworking devices. The invention eliminates complexities involved with the deployment of such systems in the past, which have typically required the computer network-compatible wiring to be extended to each access point directly from an internetworking device such as a repeater, bridge, router, or gateway.
[0010] The present invention makes it economically efficient to deploy wireless local area networking equipment in locations where wired network infrastructure is not readily available. In particular, any convenient existing physical wiring, such as may be provided by the existing coaxial cable used to distribute cable television signals, or the existing twisted pair cabling used to distribute standard telephone signals, is used as a physical layer transport medium to carry the wireless local area network signals between the access points and centrally located network hub equipment.
[0011] According to the invention, an architecture is provided that couples wireless local area network (WLAN) signals between an internetworking device and a remotely located access point using a transport network. The access point is coupled to the transport network for communicating with the internetworking device. The access point includes a wireless local area network (WLAN) access point and an access point remote converter. The WLAN access point receives wireless local area network signals from wireless computing equipment and converts such signals to local area network compatible signals. The access point remote converter receives the local area network compatible signals from the WLAN access point and converts the signals to transport modulated format signals suitable for transmission over the transport network. The transport network also provides a power signal to power at least some components of the access point.
[0012] The transport network can be implemented as an analog signal transport medium. In one particular embodiment, the transport network is a twisted pair telephone cabling and the access point remote converter converts the local area network signals to a Digital Subscriber Line (xDSL) format. The access point further includes a power supply connected to be energized by the power signal from the transport network to supply power to at least some components of the access point.
[0013] In another particular embodiment, the transport network is an optical fiber network and the access point remote converter converts the local area network signals to an optical wavelength compatible with the fiber network. The access point further includes a power supply connected to be energized by the power signal from the optical fiber network to supply power to at least some components of the access point.
[0014] A power inserter can be used for inserting the power signal onto the transport network and a signal coupler can also be used to couple the power signal from the transport network to the access point.
[0015] A head end access point that includes a head end remote bridge can be connected to receive the transport modulated format signals from the transport network and to convert such signals to data network compatible signals. A local area network hub can then be used to receive the data network compatible signals from the head end remote bridge and to forward such signals to the internetworking device.
[0016] In further particular embodiments, an access point is associated with each wireless local area network microcell. The access point includes access point equipment for communicating with portable computing equipment located within the microcell, such as may be provided in accordance with standard wireless network specifications such as the Institute of Electrical and Electronic Engineers (IEEE) 802.11 wireless LAN standard.
[0017] Rather than couple the wire line side of the access point directly through local area network format cabling such as 10 baseT or 100 baseT, an access point remote converter first converts such signals to a convenient transport format. The transport format implemented by the remote converter depends upon the available cabling.
[0018] The available transport cabling can also provide a power signal to power at least some portions of the access point.
[0019] The transport signals are collected at a central distribution or headend access point (HAP). At this location, a remote bridge then converts the signals from the convenient transport format back to the wired local area network format such as Ethernet/802.3 10 baseT or 100 baseT. These Ethernet signals are then suitable for coupling to a local area network hub, or other internetworking equipment such as repeaters, bridges, routers, gateways and the like.
[0020] As a result, it is not necessary to deploy Ethernet-compatible or other data network cabling directly to the physical location of each access point within the desired coverage area. Rather, the access points may be deployed in configurations wherever there is available transport cabling, without consideration for the cost and/or logistics of deploying local area network compatible cabling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0022] FIG. 1 is a diagram of a system for providing wireless local area network access using transport cabling according to the invention.
[0023] FIG. 2 is a more detailed block diagram of a cable access point and head end access point making use of a cable television transport media.
[0024] FIG. 3 is a block diagram of a cable access point and head end access point making use of a cable transport with IEEE 802.14 cable modem compatible interconnects.
[0025] FIG. 4 is a block diagram of a cable access point and head end access point using a twisted pair transport media.
[0026] FIG. 5 is a more detailed block diagram of the typical equipment deployed at the head end.
[0027] FIG. 6 is a more detailed diagram of the head end access point making use of a wireless local area network bridge and translation stage.
[0028] FIG. 7 is a more detailed block diagram of an alternative implementation of the cable access point.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Turning attention now to the drawings, FIG. 1 is a generalized diagram of a wireless data network 10 configured according to the invention. The wireless data network 10 makes use of multiple remotely located wireless local area network (LAN) access point locations to provide wireless LAN interconnectivity over a broad coverage area. The wireless data network 10 uses widely available, already installed cabling such as a coaxial cable, optical fiber, or twisted pair as a transport medium. This architecture provides an inexpensive way to deploy wireless LAN coverage from a centralized internetworking device without the need to distribute LAN compatible cabling to each access point location in a geographic region 11 .
[0030] More specifically, the wireless data network 10 consists of a number of microcells 12 - 1 , 12 - 2 , . . . , 12 - 4 distributed throughout a geographic region. Some of the microcells 12 may be located adjacent to other microcells and located in areas of particularly high population density, such as in an office park. Other microcells 12 may be located in residential and/or rural areas, such as microcell 12 - 4 , and may have no adjacent microcells 12 .
[0031] The present invention allows the implementation of wireless data network 10 in areas where data network wired backbone infrastructure is not readily available. For example, in the residential or rural area 12 - 4 , such data network infrastructure is not available. Likewise, the invention can be advantageously deployed even in areas such as the office park in microcell 12 - 3 where such backbone connections may already be available. In this case, the invention provides a way to distribute access points throughout a wide geographic region 11 without the need to provide network connectivity to each access point, such as through leased data lines or other transport media requiring expensive monthly rental payments.
[0032] Each microcell 12 has associated with it a corresponding cable access point (CAP) 14 - 1 , 14 - 2 , . . . , 14 - 4 . The cable access points 14 are connected to one another either serially or in parallel via an intercell transport medium 15 . It will be understood shortly the transport medium 15 is advantageously selected to be an existing wiring located in the region 11 . For example, the transport medium 15 is selected to be a cable television (CATV) cable plant, or twisted pair cabling used to provide plain old telephone service (POTS).
[0033] Heretofore, it has been required to provide a high speed, wired connection such as an Ethernet/802.3 10 baseT or 100 baseT compatible connection to each of the microcells 12 - 1 in order to carry wireless local area network signals from the access points 14 back to an internetworking device such as a LAN repeater or hub 18 . However, the invention uses especially adapted cable access points 14 and head end access points (HAPs) 16 in order to transport the wireless local area network signals over the available transport media 15 .
[0034] The head end access point (HAP) 16 couples the LAN signals between the available transport medium 15 and internetworking equipment such as a LAN repeater or hub 18 . From the LAN hub 18 , the signals may then be fed through LAN switches 20 to wired LANs 22 , through routers 22 to corporate networks 26 or public backbone Internet connections 28 , or to other internetworking equipment.
[0035] FIG. 2 is a more detailed diagram of a CAP 14 - 1 and HAP 16 - 1 that make use of existing CATV plant transport medium 15 - 1 . The CAP 14 - 1 includes an access point 34 - 1 , a remote bridge 36 - 1 , a radio frequency (RF) translator 38 - 1 , power extractor 40 - 1 and power supply 42 - 1 . Although only a single CAP 14 - 1 is shown connected to the CATV plant 15 - 1 , it should be understood that other CAPs 14 are similarly connected to the HAP 16 - 1 .
[0036] The CAP 14 - 1 receives wireless LAN signals from computing equipment 17 - 1 and 17 - 2 located within its respective microcell 12 - 1 . For example, mobile computing equipment 17 - 1 such as a laptop computer or personal digital assistant (PDA) may be fitted with a wireless LAN adapter 30 - 1 which transmits and receives wireless LAN signals 32 - 1 to and from a wireless LAN access point 34 - 1 . It should be understood that in addition to the portable type computing equipment 17 - 1 , there may also be desktop computers 17 - 2 located within the microcell 12 , equipped with wireless LAN adapters 30 - 2 .
[0037] The following discussion considers the path of a reverse link direction signal that is traveling from the computer 17 towards the LAN hub 18 . However, it should be understood that communication paths in a network are full duplex and therefore must travel in both directions; the analogous inverse operations are therefore carried out in the forward link direction.
[0038] The radio signals transmitted by the wireless LAN adapter 30 - 1 and the wireless access point 34 - 1 are preferably in accordance with the known standardized signaling format such as the Institute of Electrical and Electronic Engineers (IEEE) 802.11 wireless LAN standard. The access point 34 - 1 and wireless LAN adapter 30 - 1 are therefore available as inexpensive, off-the-shelf items.
[0039] The network side port of the access point 34 - 1 is, in the preferred embodiment, most commonly provided as a standardized Ethernet type signal compatible with 10 baseT or 100 baseT standard signaling. The remote bridge 36 - 1 thus converts the Ethernet signals provided by the access point 34 - 1 to a format suitable for connecting such signals over long distances, depending upon the available transport medium 15 .
[0040] In the case of the illustrated CATV plant 15 - 1 , the bridge 36 - 1 modulates such signals to a standard line signaling formats such as T1 carrier format. However, rather than bring the T1 compatible telecommunication line signaling directly to the location of the CAP 14 - 1 in the microcell 12 , the T1 formatted signal is instead provided to a translator 38 - 1 . The translator 38 - 1 up-converts the T1 signal to an appropriate intermediate frequency (IF) carrier for coupling over the CATV plant 15 - 1 . For example, the 1.5 MHz bandwidth T1 signal may, in the reverse link direction, be upbanded to a carrier in the range of from 5-40 MHz. In the forward link direction, that is, signals being carried from the central LAN hub 18 towards the computers 17 , the translator 38 - 1 receives signals on the intermediate frequency carrier in a range from 50-750 MHz and translates them down to a baseband T1 signaling format.
[0041] The power inserter 45 may be located at any point in the CATV plant 15 - 1 , and inserts a suitable low frequency alternating current (AC) power signal. This signal energizes the power extractor 40 - 1 and power supply 42 - 1 to generate a direct current supply signal for the CAPs 14 . A signal coupler 43 couples this AC power signal and the intermediate frequency signal energy from the translator 38 - 1 to the CATV plant 15 - 1 , and vice versa.
[0042] The head end access point (HAP) 16 - 1 contains a power supply 48 - 1 , translator 44 - 1 , and remote bridge 46 - 1 . The translator 44 - 1 provides the inverse function of the translator 38 - 1 . That is, in the reverse link direction, it converts the T1 formatted signals from the intermediate frequency carrier in a range of from 5-40 MHz back down to the baseband T1 format.
[0043] In the forward link direction, the translator 44 - 1 accepts signals converted from the LAN hub 18 through the bridge 46 - 1 , upbanding them onto a convenient carrier such as in the range of from 50-750 MHz for coupling over the CATV plant 15 - 1 .
[0044] For more information concerning the details of a suitable translator 38 - 1 and 44 - 1 , reference can be had to a co-pending U.S. patent application Ser. No. 08/998,874 filed Dec. 24, 1997 entitled “Remotely Controlled Gain Control of Transceiver Used to Interconnect Wireless Telephones to a Broadband Network.”
[0045] The remote bridge 46 - 1 then reconverts the translated reverse link signals back to Ethernet compatible signals, such as 10 baseT or 100 baseT signals which may then be processed by the LAN hub 18 or other compatible internetworking devices.
[0046] It should be understood that the CATV plant 15 - 1 may be replaced by other types of broadband distribution networks which may be conveniently available within the area 11 . The one consideration which cannot be altered is that the end-to-end propagation delays of the remoting medium must be considered to comply with the end-to-end delay criteria specified by the Ethernet/802.3 standard. For example, optical transport media may also be used in the place of the coaxial cable used for the CATV plant 15 - 1 , such as described in a co-pending U.S. patent application Ser. No. 09/256,244 filed Feb. 23, 1999 entitled “Optical Simulcast Network with Centralized Call Processing.”
[0047] FIG. 3 is a block diagram of an embodiment of the CAP 14 and HAP 16 using cable modem equipment. In this embodiment, a cable modem 37 - 1 replaces the bridge 36 - 1 and translator 38 - 1 . The cable modem 37 - 1 may be IEEE 802.14, Multimedia Cable Network System (MCNS), or Data Over Cable Service Interface Specification (DOCSIS) compatible. The net result is the same in that the Ethernet signals used for communication wit the access point 34 - 1 are converted to cable signals in the 5-750 MHz bandwidth.
[0048] FIG. 4 illustrates an alternative embodiment of the CAP 14 - 2 and HAP 16 - 2 which use twisted pair type transport medium 15 - 2 . As before, a wireless LAN compatible access point 34 - 2 provides Ethernet/802.3 compatible signals to a remote bridge 36 - 2 . In this instance, the remote bridge 36 - 2 provides a high speed digital output signal compatible with digital subscriber line (xDSL) signaling technology. Such xDSL technology uses sophisticated modulation schemes to pack data onto standard copper twisted pair wires.
[0049] Likewise, the bridge 46 - 2 disposed within the HAP 16 - 2 is compatible for converting xDSL signaling to Ethernet/802.3 signaling. The embodiment of FIG. 4 may typically be more advisable to use in areas 11 having readily available twisted pair copper wires such as used for carrying standard telephone signaling, and wherein such signaling requires only a short run to a local central telephone office of 20,000 feet shorter distance compatible with xDSL specifications.
[0050] The understanding therefore is that the bridge 36 - 1 or 36 - 2 and 46 - 1 or 46 - 2 may be any suitable type of layer two (L 2 ) bridging to the appropriate available transport media 15 - 1 or 15 - 2 , be it up-converted T1 over cable or fiber, or xDSL.
[0051] A complete implementation for a local area network 10 may thus be as shown in FIG. 5 . In particular, the subscriber site 52 contains the remotely located computers 17 . They exchange wireless local area network signaling with devices located with the CAPs 14 located at the stranded plant microcell sites 54 . In turn, the CAPs 14 use an analog distribution network implemented using whatever transport medium 15 that is readily available. The HAP 16 may itself use other analog distribution networks converts such analog signals back to appropriate Ethernet/802.3 signal formatting and forwards them to the hub 18 . The hub 18 thus provides local area network signals such as compatible with the 10 baseT standard, to network router 58 which may provide such signals to other networks over whatever long distance digital signaling is appropriate, such as to other local sub-networks over Ethernet/802.3 10 baseT type signaling, or to other remote locations such as over frame relay trunks.
[0052] FIG. 6 is a detailed view of an alternate embodiment of the HAP 16 . Here, the 802.11 air interface signal is translated in frequency to CATV transport frequencies between the HAP 16 and CAP 14 . The HAP 16 consists generally of a translating stage 60 and bridging stage 62 . A translating stage 60 provides an radio frequency translation function, accepting signals from the transport medium 15 and converting their radio band of operation. In this particular embodiment of the HAP 16 , the bridging stage 62 is provided by an 802.11 compatible wireless bridge. This device accepts signals from a wireless local area network at baseband and converts them to the 802.11 protocol for frequency conversion by the translating stage 60 . In this instance then, the translating stage 60 disposed between the bridging stage and the transport medium 15 converts the IF signaling used on the CATV transport medium 15 in the range of 5-750 MHz to the signaling in the ISM band compatible with the 802.11 wireless bridging stage 62 .
[0053] Finally, FIG. 7 shows an alternate embodiment of the CAP 14 that uses a direct RF translator 38 - 3 to interface between the CATV transport medium 15 and the 802.11 format signals in the unlicensed ISM bands (e.g., 2.4 GHz or 5.8 GHz). In particular, the analog distribution network signals in the 5-750 MHz band are translated in frequency up to an ISM band carrier by the RF translator 38 - 3 .
[0054] 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.
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An architecture is provided for coupling wireless local area network (WLAN) signals between an internetworking device and a remotely located access point using a transport network. The access point is coupled to the transport network for communicating with the internetworking device. The access point includes a wireless local area network (WLAN) access point and an access point remote converter. The WLAN access point receives wireless local area network signals from wireless computing equipment and converts such signals to local area network compatible signals. The access point remote converter receives the local area network compatible signals from the WLAN access point and converts the signals to transport modulated format signals suitable for transmission over the transport network. The transport network also provides a power signal to power at least some components of the access point.
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This application is a division of application Ser. No. 544,422, filed Oct. 21, 1983, now U.S. Pat. No. 4,531,139.
FIELD OF THE INVENTION
The present invention relates to novel color developers for use in carbonless copy papers (CCP) and thermal imaging papers (TP) which will produce a stable intense mark when placed in contact with colorless dye precursors. The present invention also relates to record material sheets bearing a coating which contains such novel color developers.
BACKGROUND OF THE INVENTION
Pressure-sensitive or heat-sensitive recording papers rely on two components to form color. One component is a colorless or slightly colored dyestuff or color precursor. The other component is an acidic material or color developer which is capable of forming a color by reaction with the dyestuff or color precursor. Marking of the recording papers is effected by pressure or heat which transfers one reactant to the other.
Pressure-sensitive recording material consists, for example, of at least one pair of sheets which contain at least one dyestuff or color precursor, dissolved in an organic solvent, and a color developer. The dyestuff or color precursor effects a colored marking at those points where it comes into contact with the color developer.
In order to prevent the color precursors contained in the pressure-sensitive recording material from becoming active prematurely, they are usually separated from the developer. This can advantageously be accomplished by incorporating the color precursors in foam-like, sponge-like, or honeycomb-like structures. Preferably, the color formers are enclosed in microcapsules which usually can be ruptured by pressure.
In a common method of manufacture of pressure-sensitive recording papers, better known as carbonless copy papers, a layer of pressure-rupturable microcapsules containing a solution of colorless or slightly colored dyestuff or color precursor, is normally coated on the backside of the front sheet of paper of a carbonless copy paper set. This coated backside is known as the CB coating. In order to develop an image or copy, the CB coating must be mated with a paper containing a coating of suitable color developer on its front. This coated front color developer coating is called the CF coating. Marking of the pressure-sensitive recording papers is effecting by rupturing the capsules in the CB coating by means of pressure to cause the dyestuff precursor solution to be exuded onto the front of the mated sheet below it. The colorless or slightly colored dyestuff, or dyestuff precursor, then reacts with the color developer in the areas at which the pressure was applied, thereby affecting the colored marking. Such mechanism or the producing technique of pressure-sensitive recording papers is well known.
Various developers for use in thermoreactive recording material are also well known. Thermoreactive recording material usually contains at least one carrier, one color precursor, one solid developer and, optionally, also a binder. The thermoreactive recording systems comprise, for example, heat-sensitive recording and copying materials and papers. These systems are used, for example, for recording information, e.g., in electronic computers, teleprinters or telewriters, or in recording and measuring instruments. The image (mark) formation can also be effected manually with a heated pen. Laser beams can also be used to produce heat-induced marks. The thermoreactive recording material can be so composed that the color precursor is dispersed or dissolved in one binder layer and the developer is dissolved or dispersed in the binder in a second layer. Another possibility consists in dispersing both the color precursor and the developer in one layer. By means of heat, the binder is softened at specific areas and the color precursor comes into contact with the developer at those points where heat is applied and the desired color develops at once.
Color precursors are well known to those experienced in the field and any such color former may be used in conjunction with the present invention, e.g., those belonging to the classes of the phthalides, fluoranes, spiropyranes, azomethines, triarylmethane-leuco dyes, of the substituted phenoxazines or phenothiazines, and of the chromeno or chromane color formers. Examples of such suitable color precursors are: crystal violet lactone, 3,3-(bisamino-phenyl)-phthalides, 3,3-(bisubstituted indolyl)-phthalides, 3-(aminophenyl)-3-indolylphthalides, 6-diaalkylamino-2-n-octylaminofluoranes, 6-dialkylamino-2-arylaminofluoranes, 6-dialkylamino-3-methyl-2-arylaminofluoranes, 6-dialkylamino-2- or 3-lower alkylfluoranes, 6-dialkylamino-2-dibenzylaminofluoranes, 6-dialkylamino-2-dibenzylaminofluoranes, 6-diethylamino-1,3-dimethylfluoranes, the lactonexanthenes, the leucoauramines, the 2-(omega substituted vinylene)-3,3-disubstituted-3-1-1-indoles, 1,3,3-trialkylindolinospirans, bis-(aminophenyl)-furyl-, phenyl- or carbazolylmethanes, or benzoyl-leucomethylene blue.
Known color developers for use in such pressure-sensitive or heat-sensitive recording papers have included:
(1) novolac phenolic resins made by acid catalyzed condensation of phenol, recorcinol, pyrogallol, cresols, xylenols, or alkyl phenols such as p-tertiary butyl phenol, with aldehydes such as formaldehyde, acetaldehyde, benzaldehyde, and butyraldehyde;
(2) Metal salts of aromatic carboxylic acids with an OH group at the ortho position, such as zinc salts of salicylic acid, 3,5-di-tert-butyl salicylic acid, octyl salicylic acid, and 1-hydroxy-2-naphthoic acid, and
(3) acid-treated clays such as kaolinites and attapulgites.
The search has continued for other developers having high developing power, rapid developing speed, good light resistance and time stability. Examples of some colored developers which have been developed in the past which are somewhat related to those of the present invention are disclosed in U.S. Pat. No. 4,291,901 to Petitpierre and Japanese patent disclosure No. 1979-111905.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a novel color developer for use in pressure-sensitive or heat-sensitive recording papers.
It is another object of the present invention to provide an improved record sheet coated with such a novel color developer.
A further object of the present invention to provide such a color developer with excellent color developing properties.
These and other objects of the present invention are obtained by means of the novel color developers of the present invention which are, in part, N-monosubstituted sulfonamides which contain at least one electron-withdrawing group. The simple sulfonamides and n-monoalkyl sulfonamides (RSO 2 NH 2 and RSO 2 NHR' respectively) have acidities that are too weak for these materials to be very useful as primary color developers. They are useful as film modifiers and/or secondary color developers. However, the addition of an electron-withdrawing group not more than five (5) atoms from the NH group on the sulfonamide increases its acidity (via the inductive effect), and makes the sulfonamides suitable for use as primary color developers. Where applicable, the pK a (--log K a , where K a is the acid dissociation constant) of the sulfonylamide (--SO 2 --NH--) group should be in the range of 9.5 to 2.5, and preferably in the range of 8 to 4. Suitable electron-withdrawing groups are those substituents which possess positive Hammett or Taft constants. The novel color developers can also be N-monosubstituted, N'-mono or di-substituted sulfamides [R'"(R o ")--N--SO 2 NHR o ']. Again for the reasons stated above, an electron-withdrawing group must be no more than 5 atoms from the NH group.
The maximum color developing potential is realized when these N-monosubstituted sulfonamides or N,N'-substituted sulfamides are used in conjunction with some source of metal or metal compound. Specifically, the sulfonamines or sulfamides may be
(1) mixed with or dissolved in an organic metal salt such as zinc oleate, zinc octoate, and zinc acetate,
(2) precipitated onto a metal oxide hydroxide, or carbonate such as zinc oxide, zinc hydroxide, or zinc carbonate,
(3) co-precipitated from water with soluble metal salts like zinc chloride, zinc ammonium chloride, or zinc sulfate, or
(4) chemically modified by a metal so as to incorporate the metal into the sulfonamide or sulfamide molecules.
The latter will take the form of organic acid salt formation by reacting either an extra ##STR1## group or a COOX group in the sulfonamide or sulfamide with a basic metal oxide or carbonate. The salt may also be formed by reaction of alkali salt of the sulfonamide (or sulfamide) with a soluble acidic metal salt such as zinc sulfate. The above examples are restricted to zinc for the sake of being concise. Other metals such as aluminum, barium, bismuth, calcium, cerium, cesium, lithium, magnesium, tin, and titanium may be used in place of zinc.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention comprehends all compounds which include a sulfonylamide (--SO 2 NH--) group and also include an electron-withdrawing atom or moiety within five atoms of the NH group. However, the compound must be free of any basic group, for example, epoxy or NH 2 . Any additional NH groups within the compound must be no more than one carbon away from an SO 2 group, or to a C═O, C.tbd.N, or NO 2 group. The present invention further excludes such compounds in which the electron-withdrawing group is a carboxy phenyl group connected through the nitrogen atom of the sulfonylamide group or in which the sole electron-withdrawing group is a carboxyphenyl group. Also excluded are compounds having a CHOH group directly connected to a nitrogen atom.
Particularly preferred sulfonylamide compounds in accordance with the present invention have electron withdrawing groups on both sides of the sulfonylamide grouping.
Subject to the above conditions, the electron withdrawing group can be any of the following: --NO 2 , --SO 2 R, --CN, --SO 2 Ar, --COOH, --SO 2 NH 2 , --SO 2 NHR, --SO 2 NR 2 , --F, --Cl, --Br, --I, --OAr, --COOR, --COOAr, --OR, --OH, --SR, --SH, --COR, --COAr, --C.tbd.CR, --Ar, --CH═CR 2 , wherein R is an alkyl group of up to 18 carbon atoms, preferably 3-8 carbon atoms, and Ar is any aryl group, preferably phenyl or naphthyl. The R and Ar groups may be optionally substituted as long as the above conditions are met.
Particularly useful compounds for use as color developers in accordance with the present invention are N-monosubstituted sulfonamides represented by formula ##STR2## where R 1 and R 2 are alkyl (branched or linear), preferably with no more than 18 carbon atoms and most preferably with 3-8 carbon atoms, aryl, preferably phenyl or naphthyl, or a combination of both, each of which may be substituted or unsubstituted, said substituents, if any, being any group other than a basic group, such as epoxy or NH 2 , and if --NH-- it must be no more than one carbon atom away from a SO 2 , C═O, C.tbd.N or NO 2 group;
G is an electron withdrawing group as defined above and is not more than five atoms away from the --NH-- group, with the proviso that G is not --OH or --SH when n is 1 and with the further proviso that --(R 2 ) n --G is not ##STR3## and n is 0 or 1.
Other sulfonamides useful in the practice of the present invention are those in accordance with formula ##STR4## wherein n, R 1 , R 2 and G are as defined above with the proviso that R 1 is not ##STR5## and with the further proviso that G is not COOH in formula II when all of the following three conditions apply: R 2 is aryl, n is 1, and R 1 does not comprehend or include an electron-withdrawing group (as defined above for G) within 5 atoms of the NH group.
Analogous to the sulfonamides above, the N-mono-substituted, N'-mono or di-substituted sulfamide color developers, which are also particularly useful in accordance with the present invention, are represented by formula III below: ##STR6## where R 2 , G and n are as defined above and R 3 and R 4 are as defined above for R 1 and R 2 although one of R 3 and R 4 may be H; furthermore, when one of R 3 and R 4 is H, the other may be an electron withdrawing group as defined above for G.
The usefulness of the N-monosubstituted sulfonamides as color developers is enhanced further by placing electron-withdrawing groups on both sides of the sulfamoyl group.
Preferred such compounds useful in the practice of the present invention are represented by formula IV: ##STR7## wherein n, R 2 and G are as defined above and G' is an electron withdrawing group as defined above with respect to G.
While the substituents with respect to formulae I-IV and the remainder of the generic formula as discussed above may include any functional group not specifically proscribed, it particularly may include additional --SO 2 NH--, alkyl, aryl and electron withdrawing (as defined above for G) groups, and may, in fact, be a polymer containing repeating units of any of the above.
Examples of compounds within formula (I) are as follows:
______________________________________N(phenyl sulfonyl)-p-toluenesulfonamide ##STR8##Nphenyl-benzene sulfonamide ##STR9##n-butyl-N(phenylsulfonyl)-p-aminobenzoate ##STR10##Nα-(p-toluenesulfonyl)-DLphenylalanine ##STR11##N(carboxymethyl)-p-toluenesulfonamide ##STR12##N[o-(p-toluenesulfonamido)phenyl]-p-toluenesulfonamide ##STR13##______________________________________
With respect to examples of compounds of formula (II), it should be noted that in Japanese patent disclosure 1979-111905, comparative compound example 3, i.e. N-(octadecyl)-o-carboxybenzene sulfonamide, is taught as being a poor developer, particularly in comparison with the anthranilic developers disclosed by the Japanese patent. It has surprisingly been discovered, however, that the addition of another electron withdrawing group, this time on the nitrogen side of the sulfonamide, further increases the color developing property and such compounds thus become preferred compounds of the present invention. Examples of compounds in formula (II) including the above described preferred compounds are as follows:
______________________________________n-butyl-N(o-carboxyphenylsulfonyl)-p-amino-benzoate ##STR14##N(o-carboxyphenylsulfonyl)-4-aminobenzophenone ##STR15##N(o-carboxyphenylsulfonyl)4-aminobenzenesulfonamide ##STR16##N(4-n-butylphenyl)-o-carboxybenzenesulfonamide ##STR17##N(4-octylphenyl)-o-carboxybenzenesulfonamide ##STR18##N(4-dodecylphenyl)-o-carboxybenzenesulfonamide ##STR19##N(2,4-diethylphenyl)-o-carboxybenzenesulfonamide ##STR20##______________________________________
With respect to all of the above acids, the preferred form is that of the metal salt, particularly an alkaline earth metal salt, and more particularly a zinc salt.
Examples of formula (III) are:
______________________________________N(dimethylsulfamoyl)-p-toluenesulfonamide ##STR21##Nphenyl-N'isopropylsulfamide ##STR22##Nbenzoyl-N'isopropylsulfamide ##STR23##Nphenyl-N',N'dimethylsulfamide ##STR24##N(dimethylsulfamoyl)-α-aminophenylacetic acid ##STR25##N(o-(N',N'dimethylsulfamoylamido)-phenyl)-dimethylsulfamide ##STR26##______________________________________
With respect to compounds under formula (IV), note the compounds already set forth hereinabove as examples under formula (II).
In addition to the above formulas, an infinite number of polyfunctional molecules can be synthesized. However, the functional group or repeating unit in each of these molecules would still be a N-monosubstituted sulfonamide or sulfamide as depicted in formulas (I) through (IV). For instance, the polysulfonamides prepared from aromatic disulfonyl chlorides and aromatic diamines, such as polycondensate of benzene disulfonyl chloride and p,p'-diaminodiphenylmethane (also called methylene dianiline): ##STR27## With respect to the above reaction scheme, the molecular weight can be controlled by carboxymethoxybenzene sulfonyl chloride as a reaction terminator. Another such a polycondensate is the product of a mild, selective hydrolysis of the methyl esters of the reaction product of two moles carboxymethoxy benzene sulfonyl chloride (CBC from Sherwin-Williams Co.) with trimethylene glycol di-p-aminobenzoate (Polacure 740M from Polaroid Corporation), trimethylene bis(N-o-carboxylphenylsulfonyl)-p-aminobenzoate ##STR28## An even superior compound is the complex of mixed zinc salt that results from reacting the above compound with more basic zinc salts.
The synthesis of all of the above compounds is quite straightforward. They are prepared by reacting the appropriate sulfonyl (or sulfamoyl) chloride with an amine, amide, or sulfonamide. The reaction (for amines) can be performed in an aqueous solution or suspension by using the Schotten-Baumann technique with sodium carbonate as base (see Scheifele and D. F. Detar, Org. Syn. Coll. Vol. 4, 34 (1963)). Alternatively, the reaction (for amides and sulfonamides) may be performed in an inert solvent such as acetonitrile (see E. Muller, ed. Methoden der Organischer Chemie (Houben-Weyl), vol. 9, 4th ed., Georg Thieme Verlag, Stuttgart, West Germany, pp. 398-404, 605-648 (1955)).
The following compounds are further examples of the present invention:
______________________________________Ntoluenesulfonyl-α-aminophenylacetic acid(Ntoluenesulfonyl-α-phenylglycine) ##STR29##Nphenylsulfonyl-α-aminophenylacetic acid ##STR30##N(m-carboxybenzoyl)-p-toluenesulfonamide ##STR31##N(m-carboxybenzoyl)-benzenesulfonamideN(m-carboxybenzoyl)-N',N'dimethylsulfamideN(o-carboxybenzoyl)-p-toluenesulfonamide ##STR32##N(o-carboxybenzoyl)-benzenesulfonamideN(o-carboxybenzoyl)-N',N'dimethylsulfamideN(m-nitrobenzoyl)-p-toluenesulfonamide ##STR33##N (m-nitrobenzoyl)-benzenesulfonamideN(m-nitrobenzoyl)-N',N'dimethylsulfamideN(p-nitrobenzoyl)-p-toluenesulfonamide ##STR34##N(p-nitrobenzoyl)-benzenesulfonamideN(p-nitrobenzoyl)-N',N'dimethylsulfamideN(phenylsulfonyl)-p-toluenesulfonamide ##STR35##N(phenylsulfonyl)-benzenesulfonamide4,4'-oxybis[N(phenylsulfonyl)-benzenesulfonamide] ##STR36##______________________________________
It should be noted that the most preferred electron withdrawing groups (G and G') are --SO 2 R; --COOH; --OR; --COOR; --COR; --NO 2 ; --CN; and the halides. The most preferred set of electron-withdrawing groups are --SO 2 R; --COOH; --OR; --COOR; and --COR.
The following preparative example shows a method of synthesis of one of the compounds used in the present invention. It should be understood that all of the other compounds can be made by analogous synthesis or in manners which are already known to the prior art, or could be derived from methods known to the prior art without undue experimentation. Throughout all of the present examples and claims all percentages are by weight unless otherwise indicated.
PREPARATIVE EXAMPLE
Preparation of N-(p-n-butylphenyl)-o-carboxybenzene sulfonamide ##STR37##
The first stage of the reaction (as shown in reaction scheme I hereinabove) is carried out by dissolving 254.4 g (2.4 moles) of sodium carbonate (granular, 99+%, ACS reagent grade) in 1.5 liters of water. The solution is heated to 50° C., and at 50°-60° C., 149.2 g or 157 ml (1 mole) of p-n-butylaniline (97% purity) and 281.6 g of carbomethoxybenzene sulfonyl chloride (commercially available under the name CBC) are added alternately in five portions each. The dual additions of the five portions of each reactant are timed at approximately 5 minute intervals. That is, 31.6 ml of butylaniline is added and followed directly by the addition of 56.32 g of CBC. After 5 minutes have passed, the next portions are added again in immediate succession, i.e., 31.6 ml butylaniline followed by 56.32 g CBC. This continues until all five portions of each reactant have been added. Sodium hydroxide may be added in case carbon dioxide is evolved which occurs if an insufficient amount of sodium carbonate is present.
After all of the reactants have been added, the temperature is raised to 80° C. and held for 25 minutes, and the mixture then cooled to room temperature. ##STR38##
Reaction scheme II is carried out by slowing adding the cooled reaction mixture into a 4 liter beaker containing 250 ml water and 300 ml of hydrochloric acid (37%), and equipped with an efficient stirrer, taking care that the mixture does not foam over. The dispersion is chilled in a refrigerator over night. The crude N-(p-n-butylphenyl)-o-carbomethoxy benzene sulfonamide settles on the bottom of the beaker as a brownish, viscous mass. The water layer is poured off and replaced by a solution of 80 g sodium hydroxide in 1.5 liter of water. The resulting solution is heated for 2 hours at 85° C. to hydrolize the methyl ester (reaction scheme III). ##STR39##
The solution is filtered at room temperature to remove a very small amount of black precipitate. The solution is again poured into a 4 liter beaker containing 250 ml water and 300 ml hydrochloric acid (37%). (Reaction scheme IV) ##STR40##
The product is isolated by filtration using a Buchner funnel, and is washed with water on the filter. The filtrate is allowed to air dry, and then pulverized to a light brown to beige powder. The yield is approximately 90% (based on butylaniline) and purity is approximately 96%. The procedure could be simplified by consolidating reactions I and III, as well as II and IV, thereby avoiding the difficult to handle methyl ester. The procedure is an adaptation of the related preparation of p-toluenesulfonyl anthranilic acid as submitted by H. J. Scheifele, Jr. and D. F. DeTar in Organic Synthesis, Collective, volume 4, p. 37 (1963).
The following examples show methods of formulating coatings containing the developers of the present invention for application to pressure-sensitive recording papers. The coatings are formulated to be porous. This permeability is usually obtained through the use of fillers, such as aluminum oxide, zinc oxide, silicon dioxide, clay or organic thixotropes. The binders are predominantly saturated aliphatic or aromatic compounds. The number of extraneous, organic, polar groups in the final, dried coating are kept to an absolute minimum. Acid groups and their metal salts are the notable exceptions. The color developer should be the predominant, non-fugitive, polar material in the CF coating. For example, in the moisture set ink below, the full color developing potential appears only after the solvents (diethylene glycol, triacetin, and absorbed water) leave the film during the setting process. It will be understood that other fillers, binders and solvents can be used to complete the compositions of the present invention, all as are conventional in this art and well known.
EXAMPLE 1
An Aqueous Coating
5.4% trimethylene bis(N-(o-carboxylphenylsulfonyl)-p-aminobenzoate) was added to 3.7% ammonium hydroxide in 26% aqueous solution and 50% water, and mixed until completely dissolved. Thereupon 10% Pencoate RBB 725 (an oxidized starch from Penick and Ford, Division of Pacific Resins and Chemicals, Inc.), 1% zinc ammonium chloride and 30% zinc oxide were added and mixed thoroughly in a high speed mixer or mill.
As an alternative to the above approach of incorporation, the sulfonamide (or its zinc salt) may be pulverized in a ball mill, and then simply mixed with the rest of the components. If zinc salt is used, then the ZnO may be replaced by hydrated alumina.
EXAMPLE 2
A Letterpress Coating--Moisture Set Ink
A kettle was charged with 24.7% diethylene glycol and 24.7% triacetin (glyceryl triacetate). 5% Lacros 294 (an acid modified rosin resin from Crosby Chemicals, Inc.) was added and heated to 95° C. for 30 minutes or until dissolved. Thereupon, 30.0% n-butyl-N-(o-carboxyphenylsulfonyl)-p-aminobenzoate was added and, upon dissolution, 4.0% Kadox 15 (zinc oxide-chemical grade from New Jersey Zinc Co.) was added. The temperature was maintained at 100°-105° C. for one hour, although a longer heating period may be required for more inert grades of ZnO. 5.0% of diethylene glycol monostearate, 5.0% zinc octoate and 0.1% benzotriazole were added in quick succession and cooled to 65° C. Then 1.5% (or less, if preferred) Crayvalac SF (organic thixotrope from Cra-Vac Industries, Inc.) was added and dispersed thoroughly with a high speed mixer, and drained through a mesh filter. The active ingredient is the zinc salt n-butyl-N-(o-carboxyphenylsulfonyl)-p-aminobenzoate.
EXAMPLE 3
A Flexo-Gravure Coating
10% trimethylene bis(N-o-carboxyphenylsulfonyl)-p-aminobenzoate) and 16.0% Lacros 294 were dissolved in 62% ethyl alcohol. To this solution, 10.0% zinc octoate (18% Zn) were added while stirring. Into this clear solution were dispersed 2.0% Alumina Oxide C (fumed aluminum oxide from Degussa Corp.) or 2.0% fumed silica (trade name "Aerosil" 200 or R 972 from Degussa Corp.).
EXAMPLE 4
Transfer Litho (Letterpress) Ink
A mixture of 37.0% mineral seal oil and 30.3% zinc octoate (96% pure with remainder as mineral seal oil) is heated to 100° C. and then 10.2% zinc resinate (Poly Tac 100 from Reichhold Chemicals Inc.) is added. After a clear solution is obtained, 18% N-(p-n-butylphenyl)-o-carboxybenzene sulfonamide prepared by the method of the preparative example above, is added. 2.2% zinc oxide (Kadox 15 from New Jersey Zinc Co.) is dispersed into the solution and the solution is heated for 11/2 hours at 100°-117° C. The mixture is cooled down to 80° C. and 1.5% Cravalac SF is dispersed with a high speed mixer. If the texture of the ink is too coarse, the ink is passed through a 3-roll mill. The color developer is present in the form of a fine dispersion.
EXAMPLES 5 AND 6
Following the same general procedure as set forth in example 4, other transfer litho (letterpress) inks can be made using different sulfonamides. Two examples of same showing the relative amounts of components are set forth hereinbelow in Table I:
TABLE 1______________________________________ Examples 5 6Components wt. % wt. %______________________________________Mineral seal oil 33.7 32.4Zinc octoate 28.0 25.4Zinc resinate 6.7 5.9N--(4-n-octylphenyl-o-carboxy- 26.4 0benzenesulfonamideN--(4-n-dodecylphenyl)-o-carboxy- 0 32.4benzenesulfonamideZinc oxide 2.7 2.9Cravalac SF 1.5 1.1______________________________________
The color developers in 5 and 6 are present in solution.
Table 2 shows the color developing power of the products of examples 4, 5 and 6, as compared to a commercial product:
TABLE 2__________________________________________________________________________ Coating Wt. of Color Developer Coating Wt. NCR - Blue (CB) NCR - Black (CB) Test CB.sup.1 - Black (g/m.sup.2) of Ink BNL No..sup.2 Color BNL No. Color BNL No. Color__________________________________________________________________________Example 4-CF 0.11 0.6 g/m.sup.2 69 ± 2 Violet 50 ± 1 Reddish- 39 ± 1 Reddish- Black BlackExample 5-CF 0.21 0.8 g/m.sup.2 59 ± 1 Blue 49 ± 2 Reddish- 33 ± 3 Black (Reddish) BlackExample 6-CF 0.24 0.75 g/m.sup.2 63 ± 2 Blue 47 ± 2 Reddish- 33 ± 2 BlackCommercial 0.8-1.2 Aqueous 43 ± 3 Blue 42 ± 3 Black 31 ± 1 Greenish-NCR-CF Coating Black__________________________________________________________________________ .sup.1 An approximately 5 g/m.sup.2 coating of a 40% by weight capsule slurry containing a solution of CibaGeigy Pergascript IBR Dye in diisopropyl biphenyl (7% dye on oil by weight). .sup.2 Reflectance Scale 0-100; the lower the number, the darker the imag
EXAMPLE 7
Comparative Example
The following is a comparison proving the superiority of the compounds of the present invention to those of comparative compound 3 in Japanese patent application 1979-111905.
1(a) 10 g zinc salt of N-(4-dodecylphenyl)-o-carboxybenzenesulfonamide was dissolved in 50 ml of ethyl acetate, as described in "Application 1" of JP 1979-111905. This solution was applied to 11 lb. paper stock (41 g/m 2 ) at a coating weight of 0.2 g/m 2 . The resulting CF1 sheet was mated with commercial NCR CB paper (15#), and the 2-ply formset was fed through a mini-calander set at 30 psi pressure to produce 37 kg/cm. After one hour, the image intensity was measured on a BNL-2 Opacimeter from Technidyne Corporation as reflectance percent of the imaged area relative to the sheet.
1(b) A CF2 was made and tested as above except the coating solution contained 10 g N-(4-dodecylphenyl)-o-carboxybenzenesulfonamide and 10 g zinc octoate in 50 ml ethyl acetate.
2(a) The above procedure 1(a) was repeated using the zinc salt of N-(octadecyl)-o-carboxybenzenesulfonamide as the color developer to produce CF3.
2(b) A CF4 sheet was prepared as in 1(b) except N-(octadecyl)-o-carbonylbenzenesulfonamide was used as the color developer.
Results: A low reflectance value, R, represents an intense image.
TABLE 3______________________________________ ReflectanceCF Sheet % Comments______________________________________Zn[N--4-dodecylphenyl)-o- 58 The preferred colorcarboxybenzenesulfonamide].sub.2 developers of theCF1 present inventionN--(4-dodecylphenyl)-o- 54carboxybenzenesulfonamideCF2Zn[N--octadecyl)-o- 96* The comparativecarboxybenzenesulfonamide].sub.2 compound 3 inCF3* JP 1979-111905N-octadecyl)-o- 87carboxybenzenesulfonamideCF4Plain 11 lb (41 g/m) 100Paper stockCommercial NCR 46 Phenolic resin usedCF paper 15# as color developer. Coat weight ≈ 0.8-1.2 g/m.sup.2______________________________________ *The coating solution of CF3 was not homogeneous. As a result, CF2 and CF is better comparison
The preferred color developer is significantly better than the comparative compound 3.
It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is described in the specification.
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Color developers for use in pressure-sensitive or heat-sensitive recording papers comprise N-monosubstituted sulfonamides which contain at least one electron-withdrawing group within five atoms of the amido group of the sulfonamide. The N-monosubstituted sulfonamide may be in the form of an N-substituted, N'-mono or di-substituted sulfamide, or a polyfunctional molecule containing such an N-monosubstituted sulfonamide as the functional or impeding group thereof. The maximum color developing potential is realized when these compounds are used in conjunction with a source of metal or metal compound.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to the prevention of metal dusting corrosion, and in particular to preventing or inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube heat exchanger, such as a gas heated reformer.
[0002] The invention is discussed herein with respect to gas heated reformers. However, persons skilled in the art will recognize that the invention may be applied to any shell-and-tube heat exchanger wherein a shellside gas may cause metal dusting to occur on the back of a tubesheet.
[0003] Syngas (a mixture of hydrogen and carbon monoxide) is produced by steam reforming and/or partial oxidation of natural gas or other hydrocarbons. Syngas processes are being developed which teach the use of hot reformed gas as a heat source to provide heat for the endothermic reforming of more feedstock. Such processes often use a “gas heated reformer,” a shell-and-tube heat exchanger type device comprising tubes containing catalyst used for the reforming and a shell in which hot gases from a second reforming step provide the thermal energy required for the endothermic reaction.
[0004] There are two basic types of gas heated reformers. The first is a classical shell-and-tube heat exchanger in which the heating and cooling streams do not mix. The second is a “2 in 1 out” type of reformer in which the reacting stream mixes with the heating stream within the unit.
[0005] The selection of materials of construction for gas heated reformers is a concern because most metals are prone to “metal dusting,” a form of localized degradation or corrosion that occurs in environments containing carbon and hydrogen compounds but almost no oxygen. Metal dusting occurs when carbon monoxide gases are cooled such that the equilibrium of the reaction in equation 1 moves to the right hand side:
2 CO C+CO2 Equation 1
[0006] The carbon formed by this reaction diffuses into metal surfaces forming metal carbides. The metal carbide separates from the parent metal and leaves the system. This process is collectively referred to as metal dusting.
[0007] At temperatures sufficiently high where the equilibrium of the reaction in equation 1 favors the left side, no carbon can form and thus metal dusting cannot take place. At low temperatures, the kinetics for the reaction in equation 1 are low and the reaction rate is extremely slow so that metal dusting does not occur, or if it does occur, it is at a rate so low as to cause no concern. At intermediate temperatures, generally between about 800° F. and 1,300° F., metal dusting is a concern. Most proposed gas heated reformers will operate within the range of temperatures where metal dusting does occur.
[0008] Some commonly used techniques or methods to reduce metal dusting provide dense layers of alloys or other materials on the metal surface which prevent the gas from contacting the base metal. Examples are sulfides or oxides coupled with alumina and silica. However, the temperatures in the process and the thermal expansions and contractions caused by the temperature changes bringing the unit from ambient to operating temperature can produce defects in the surface oxide and sulfide layers. Some alloys, such as Alloy 601 H, provide resistance to metal dusting. Another technique is to use a pack cementation process which produces an aluminum-rich layer on the treated metal.
[0009] The pack cementation process is a process that deposits an aluminum rich layer on a metallic surface. The metal piece(s) is (are) placed in a retort and covered with an aluminum containing powder. The powder also contains a halide which is used to move the aluminum (as an aluminum halide) to the base metal surface where it alloys with the base metal forming a metal aluminide. The process needs high temperatures to mobilize the aluminum, so it takes place in a furnace at temperatures or about 1700-2000° F. depending on the base metal and the amount of aluminum to be deposited. One company that can apply such an aluminum rich coating is Alon Surface Technologies Inc.
[0010] Air Products and Chemicals, Inc. has developed a gas heated reformer in which the tubes are protected using such a pack cementation process. The shell walls are protected by refractory, but the back of the tubesheet has no metal dusting corrosion protection. This is due to the metallurgy of the tubesheet and the potential for thermal distortion of the tubesheet during the pack cementation process and the difficulty of attaching tubes to the tubesheet afterwards. Once the tubes have been attached to the tubesheet, the assembly is too large to be so protected. The problem is how to prevent the back of the tubesheet in this type of gas heated reformer from undergoing metal dusting attack.
[0011] A similar gas heated reformer is taught in U.S. Pat. No. 4,919,844 (Wang), which discloses an enhanced heat transfer reformer (EHTR). Metal dusting was not a concern in the operation of the first EHTR's, since the operating conditions were deliberately chosen such that the temperature of the syngas contacting the back of the tubesheet was not in the range where metal dusting occurs. However, to take advantage of the full potential of the EHTR, later versions and processes in which EHTR units have been incorporated operate at conditions at which the back of the tubesheet are exposed to gas that will result in metal dusting.
[0012] In the 2 in 1 out type EHTR, a first stream comprising a mixture of natural gas and steam is fed to the top of the tubesheet, and the mixture then passes through catalyst containing tubes. The gas is heated as it passes through the tubes and reacts to form a mixture (syngas) of hydrogen, carbon monoxide, and carbon dioxide according to the steam reforming and water gas shift reactions. The feed mixture may or may not be subjected to an adiabatic pre-reforming step prior to being fed into the EHTR. The feed mixture also may contain any hydrocarbon other than natural gas that is normally reformed to provide syngas.
[0013] A second stream of hot reformed gas from a conventional steam methane reformer, autothermal reformer, or other syngas generating device known in the industry. Since it has been reformed, this second stream is somewhat hotter than the first stream. The heat contained in the second stream is used to provide the energy for reforming the first stream. This second stream enters the EHTR at the end of the unit where the first stream is exiting from the tubes; it mixes with the gas exiting the tubes and then passes up the unit on the shellside giving up its heat as it goes. The heat transferred from the shellside to the tubeside of the unit is sufficient for the reaction occurring inside the tubes. Once the shellside gas reaches the top of the unit, it exits the unit for further processing.
[0014] As the EHTR has been incorporated into additional processes, the need for greater efficiency has resulted in modified operating conditions (e.g., temperatures and pressures) such that the exiting gas is within the range where metal dusting occurs. Therefore, there is a need to protect the back of the tubesheet from metal dusting. The prior art has not adequately addressed this need.
[0015] U.S. Pat. No. 5,935,517 (Röll et al.) discloses a method to protect a refractory lined transfer line from metal dusting. Gas tight chambers are formed within the refractory with a ring, and the chambers are purged with a CO-free gas (e.g., water vapor, H 2 , N 2 , CO 2 or mixtures thereof) that does not result in metal dusting, the purge gas diffusing through the generally porous refractory.
[0016] An article entitled “Mega-ammonia round-up” in Nitrogen & Methanol, No. 258, July-August, 2002, which discusses the KBR (Kellogg, Brown & Root) KRES reactor, states on page 45 at column 3, last paragraph, that: “By limiting the mixed feed inlet temperature to 580-610° C. and applying a refractory face to the shell side of the tubesheet . . . in a lower-grade material than the alloy 601 used in previous units . . . .” This seems to imply that KBR has chosen to use a material selection (alloy 601 or refractory lining) to avoid metal dusting on the back of the tubesheet for a gas heated reformer of the 2 in 1 out type.
[0017] An article entitled “Improve steam reformer performance” in Hydrocarbon Processing, March 1996, states in the first paragraph on page 73 that: “Several design strategies can be implemented to prevent MDC [Metal Dusting Corrosion]: Displace syngas by a suitable purge.” The article goes on to describe a methodology for utilizing an inert purge along with other design details to mitigate the potential for metal dusting in a collection manifold from a steam methane reformer, as opposed to a gas heated reformer.
[0018] It is desired to have an apparatus and method to protect the back of a tubesheet from metal dusting in a shell-and-tube heat exchanger.
[0019] It is further desired to have an apparatus and a method to prevent or inhibit metal dusting corrosion of a tubesheet inside a gas heated reformer.
[0020] It is still further desired to have an apparatus for heat exchanging at least one process fluid in which a tubesheet in the apparatus is protected from metal dusting.
[0021] It is still further desired to have a method for assembling a heat exchanger for heat exchanging at least one process fluid which includes a means for preventing or inhibiting metal dusting corrosion of a tubesheet in the heat exchanger.
[0022] It also is desired to have an apparatus and method for inhibiting metal dusting corrosion of a tubesheet inside a heat exchanger which affords better performance than the prior art, and which overcomes many of the difficulties and disadvantages of the prior art to provide better and more advantageous results.
BRIEF SUMMARY OF THE INVENTION
[0023] The present invention is an apparatus and a method for inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube heat exchanger. The invention also includes a method for assembling a shell-and-tube heat exchanger for heat exchanging at least one process fluid, and a process for heat exchanging at least one process fluid, the process including a method for inhibiting metal dusting corrosion.
[0024] With regard to the apparatus, a first embodiment is an apparatus for inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube heat exchanger having at least one exit nozzle for transmitting at least one process fluid from the shell-and-tube heat exchanger. The apparatus includes: an isolation baffle disposed inside the shell-and-tube heat exchanger at a location between a first exit nozzle and the tubesheet, whereby an isolated space exists between the tubesheet and the isolation baffle; and a means for purging the isolated space with a purging fluid.
[0025] There are several variations of the first embodiment. In one variation, the purging fluid is a portion of the process fluid. In another variation, the tubesheet has a substantially circular shape having a first radius from a center of the isolation baffle and the plurality of apertures are in a substantially circular pattern within the tubesheet at a second radius approximately equal to the first radius multiplied by {square root}{square root over (2/)}2.
[0026] In another variation, the tubesheet has a plurality of apertures and at least a portion of the purging fluid passes through the apertures into the isolated space. In a variant of that variation, the first exit nozzle is at a first location and a second exit nozzle is at a location opposite the first location, and at least a majority of the apertures are aligned in the tubesheet in a substantially straight line substantially perpendicular to another straight line extending from the first location to the second location.
[0027] In yet another variation, the means for purging the isolated space also includes an inlet nozzle in fluid communication with the isolated space. In a variant of this variation, at least a portion of the purging fluid is steam. In another variant, the apparatus also includes a means for passing at least a portion of the purging fluid through the isolation baffle, whereby the purging fluid mixes with at least a portion of the process fluid.
[0028] A second embodiment is similar to the first embodiment but also includes a means for passing at least a portion of the purging fluid through the isolation baffle, whereby the purging fluid mixes with at least a portion of the process fluid.
[0029] A third embodiment is an apparatus for inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube gas heated reformer having a shell adapted to contain a shellside process fluid in at least one tube adapted to contain a tubeside process fluid, the shell-and-tube gas heated reformer having at least one exit nozzle for transmitting at least a portion of the shellside process fluid from the shell-and-tube gas heated reformer. This apparatus includes: an isolation baffle disposed inside the shell-and-tube gas heated reformer at a location between the exit nozzle and the tubesheet, whereby an isolated space exists between the tubesheet and the isolation baffle; a means for purging the isolated space with a purging fluid, wherein the purging fluid is a portion of the tubeside process fluid, and wherein the tubesheet has a plurality of apertures and at least a portion of the purging fluid passes through the apertures into the isolated space; and a means for passing at least a portion of the purging fluid through the isolation baffle, whereby the purging fluid mixes with at least a portion of the shellside process fluid.
[0030] A fourth embodiment is an apparatus for heat exchanging at least one process fluid, which includes: an elongated shell enclosing an interior region; a tubesheet disposed in the interior region; at least one exit nozzle adapted to transmit at least a portion of the process fluid from the interior region to an exterior location; an isolation baffle disposed inside the interior region at an interior location between the exit nozzle and the tubesheet, whereby an isolated space exists in the interior region between the tubesheet and the isolation baffle; and a means for purging the isolated space with a purging fluid.
[0031] A fifth embodiment is similar to the fourth embodiment but also includes a means for passing at least a portion of the purging fluid through the isolation baffle, whereby the purging fluid mixes with at least a portion of the process fluid.
[0032] With regard to the method, a first embodiment is a method for inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube heat exchanger having at least one exit nozzle for transmitting at least one process fluid from the shell-and-tube heat exchanger. The method includes multiple steps. The first step is to provide an isolation baffle inside the shell-and-tube heat exchanger at a location between a first exit nozzle and the tubesheet, whereby an isolated space is created between the tubesheet and the isolation baffle. The second step is to purge the isolated space with a purging fluid.
[0033] There are several variations of the first embodiment of the method. In one variation, the purging fluid is a portion of the process fluid. In another variation, the tubesheet has a substantially circular shape having a first radius from a center of the tubesheet and the plurality of apertures are in a substantially circular pattern within the isolation baffle at a second radius approximately equal to the first radius multiplied by {square root}{square root over (2/)}2.
[0034] In another variation, the tubesheet has a plurality of apertures and at least a portion of the purging fluid passes through the apertures into the isolated space. In a variant of this variation, the first exit nozzle is at a first location and a second exit nozzle is at a second location opposite the first location, and at least a majority of the apertures are aligned in the tubesheet in a substantially straight line substantially perpendicular to another straight line extending from the first location to the second location.
[0035] A second embodiment of the method is similar to the first embodiment but includes an additional step of passing at least a portion of the purging fluid through the isolation baffle, thereby mixing the purging fluid with at least a portion of the process fluid.
[0036] A third embodiment of the method is similar to the first embodiment but includes two additional steps. The first additional step is to provide an inlet nozzle in fluid communication with the isolated space. The second additional step is to feed a stream of the purging fluid to the isolated space from the inlet nozzle. In a variation of this embodiment, at least a portion of the purging fluid is steam.
[0037] A fourth embodiment is a method for inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube gas heated reformer having a shell adapted to contain a shellside process fluid in at least one tube adapted to contain a tubeside process fluid, the shell-and-tube gas heated reformer having at least one exit nozzle for transmitting at least a portion of the shellside process fluid from the shell-and-tube gas heated reformer. This embodiment includes multiple steps. The first step is to provide an isolation baffle inside the shell-and-tube gas heated reformer at a location between the exit nozzle and the tubesheet, whereby an isolated space is created between the tubesheet and the isolation baffle. The second step is to purge the isolated space with a purging fluid, wherein the purging fluid is a portion of the tubeside process fluid, and wherein the tubesheet has a plurality of apertures and at least a portion of the purging fluid passes through the apertures into the isolated space. The third step is to pass at least a portion of the purging fluid through the isolation baffle, thereby mixing the purging fluid with at least a portion of a shellside process fluid.
[0038] Another aspect of the invention is a process for heat exchanging at least one process fluid, the process including a method for inhibiting metal dusting corrosion as in any of the above embodiments of the method or variations thereof.
[0039] The invention also includes a method for assembling a shell-and-tube heat exchanger for heat exchanging at least one process fluid. The method for assembling includes multiple steps. The first step is to provide an elongated shell enclosing an interior region. The second step is to install a tubesheet in the interior region. The third step is to provide at least one exit nozzle adapted to transmit at least a portion of the process fluid from the interior region to an exterior location. The fourth step is to install an isolation baffle inside the interior region at an interior location between the exit nozzle and the tubesheet, whereby an isolated space is provided in the interior region between the tubesheet and the isolation baffle. The fifth step is to provide a means for purging the isolated space with a purging fluid.
[0040] A second embodiment of the method for assembling is similar to the first embodiment but includes the additional step of providing a means for passing at least a portion of the purging fluid through the isolation baffle, whereby the purging fluid mixes with at least a portion of the process fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The invention will be described by way of example with reference to the accompanying drawings, in which:
[0042] [0042]FIG. 1 is a schematic diagram illustrating a side view of a gas heated reformer incorporating one embodiment of the present invention;
[0043] [0043]FIG. 2 is a schematic diagram illustrating the top view of a tubesheet with edge purge ports used in the embodiment shown in FIG. 1;
[0044] [0044]FIG. 3 is a schematic diagram illustrating a side view of a gas heated reformer incorporating another embodiment of the present invention;
[0045] [0045]FIG. 4 is a schematic diagram illustrating a top view of a tubesheet having central purge ports used in the embodiment illustrated in FIG. 3; and
[0046] [0046]FIG. 5 is a schematic diagram illustrating a side view of a gas heated reformer having an inlet nozzle for use in purging in yet another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0047] The present invention includes an apparatus and method to protect the tubesheet of a shell-and-tube heat exchanger, such as a gas heated reformer or enhanced heat transfer reformer (EHTR), from metal dusting. This includes partially isolating the tubesheet from the process gas by means of an isolation baffle and sweeping the volume between the tubesheet and the isolation baffle with a gas that will not promote metal dusting, thereby protecting the back of the tubesheet.
[0048] The present invention provides a means and arrangement to keep the hot process gas on the shell side of the unit from contacting the backside of the tubesheet by providing a zone (isolated space) to be swept with a purge gas that inhibits metal dusting, introducing said purge gas into the zone, and allowing that purge gas to mix with the balance of the syngas leaving the unit for further processing.
[0049] [0049]FIG. 1 illustrates a side view of a gas heated reformer such as an EHTR 20 incorporating one embodiment of the present invention. In this embodiment, the purge ports 22 are near the edge of the tubesheet 18 , as shown in FIGS. 1 and 2. Some other key features of the invention are discussed below.
[0050] A gas distribution baffle 38 is provided below the exit nozzle 14 to ensure even flow of gas over all the tubes as the gas travels vertically up the shell side of the EHTR 20 . Without this baffle, the gas would tend to short circuit to the exit bypassing those tubes located opposite the shell from the exit nozzle.
[0051] An isolation baffle 12 is located above the exit nozzle 14 separating the flow path of the combined synthesis gas (syngas) from a protected or isolated space 16 between the isolation baffle and the tubesheet 18 .
[0052] The purge ports 22 in the tubesheet 18 allow a small portion of feed gas to leak through the tubesheet and purge the isolated space 16 between the tubesheet and the isolation baffle 12 . The flow through the purge ports is carefully calibrated to provide a minimum velocity in the annuli (not shown) between the tubes 26 and the isolation baffle 12 , and the annulus (not shown) between the isolation baffle 12 and the inner wall 28 of the EHTR 20 . The location and spacing of the purge ports is chosen to provide one of several flow patterns in the isolated space between the tubesheet and the isolation baffle. The selection depends on the relative clearances (the annuli) between the tubes and the isolation baffle, and between the isolation baffle and the inner wall of the EHTR. In the embodiment shown in FIGS. 1 and 2, the flow is generally across the tube bundle toward the exit nozzle 14 from the inner wall of the EHTR diametrically opposite the exit nozzle.
[0053] [0053]FIG. 2 illustrates the tubesheet 18 with the catalyst containing tubes 26 and the purge ports 22 in the tubesheet. The flow from the purge ports is designed to sweep the entire volume of the isolated space 16 between the isolation baffle 12 and the tubesheet 18 , as shown in FIG. 1.
[0054] [0054]FIGS. 3 and 4 illustrate another embodiment of the invention with the purge ports 22 located more centrally in the tubesheet 18 . In this embodiment, the purge ports are located on a circle with radius
R Hole Circle =R Tubesheet * {square root}{square root over (2/)}2 Equation 2
[0055] so that there is an equal area inside and outside the “hole circle.” In this embodiment the flow from the purge ports is from the purge ports outward and inward in the area between the isolation baffle 12 and the tubesheet 18 . In this case, since the purge gas flow does not have as far to travel, there is a greater probability that the flow will be more uniform through the annuli between the tubes 26 and the isolation baffle 12 , and the annulus between the isolation baffle 12 and the inner wall 28 of the EHTR 20 .
[0056] While the embodiments shown in FIGS. 1-4 use a portion of the process fluid as the purge gas or sweep gas, there may be situations where that is not desirable. For example, since the purge gas will not be reformed, the concentration of higher hydrocarbons may be unacceptable for downstream processing, or the methane in the feed may increase the overall methane concentration to an unacceptable level. In these cases, a purge gas other than the feed gas may be desired. For example, a stream 32 of steam may be used for purging, as shown in FIG. 5. Steam will adequately purge the isolated space 16 between the isolation baffle 12 and the tubesheet 18 ; and since it introduces no impurities into the process stream, the steam can be added at higher levels than feed gas, if needed.
[0057] While an internal manifold (not shown) could be constructed within the feed enclosure of the EHTR 20 , it is simpler to add the steam through a single external nozzle (inlet nozzle) 34 in the sidewall 36 of the EHTR. In this case, since the steam (purge gas) will be introduced at a single point rather than in a distributed manner, slightly more steam may be needed to adequately ensure that the steam is properly distributed across all of the annuli between the isolation baffle 12 and the tubes 26 , and the annulus between the isolation baffle 12 and the inner wall 28 of the EHTR.
[0058] Other hole patterns through the tubesheet 18 can be used if it is desired to direct the purge gas in a particular manner. For example, the EHTR 20 may have two exit nozzles 14 rather than one. If the exit nozzles are arranged 180° apart, the most preferred manner to arrange the purge ports 22 is on the diameter perpendicular to the diameter between the two exit nozzles. Other patterns may be preferred for different orientations of the exit nozzles to ensure adequate purging of the isolated space 16 .
[0059] Although illustrated and described herein with reference to certain specific embodiments, the present invention is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention.
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An apparatus and a method for inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube heat exchanger having at least one exit nozzle for transmitting at least one process fluid from the shell-and-tube heat exchanger include and use: an isolation baffle disposed inside the shell-and-tube heat exchanger at a location between a first exit nozzle and the tubesheet, whereby an isolated space exists between the tubesheet and the isolation baffle; and a means for purging the isolated space with a purging fluid.
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BACKGROUND OF THE INVENTION
[0001] Hot cathode ionization gauges are the most common non-magnetic means of measuring very low pressures and the most widely used version worldwide was disclosed in U.S. Pat. No. 2,605,431 in 1952. A typical ionization gauge includes an electron source or a cathode. The electrons emitted by the electron source collide with gas atoms and molecules in an ionization volume and produce ions. The rate at which the ions are formed is directly proportional to the density of the gas (pressure at a constant temperature) in the gauge.
[0002] Two types of ionization gauges exist: hot cathode and cold cathode. The most common hot cathode ionization gauge is the Bayard-Alpert (B-A) gauge. The B-A gauge includes a heated filament (cathode) that emits electrons toward a cylindrical wire grid (anode) defining an ionization volume (anode volume). The temperature spread for most commonly used cathodes is about 1,500 degrees Celsius to about 2,200 degrees Celsius. An ion collector electrode is disposed within the ionization volume. Electrons travel from the electron source toward and through the anode, and are eventually collected by the anode. In their travel, the electrons impact molecules and atoms of gas and create ions. The ions are attracted to the ion collector electrode by the electric field within the anode volume. The pressure of the gas within the ionization volume can be calculated from ion current (I ion ) generated in the ion collector electrode and electron current (I electron ) generated in the anode by the formula P=(1/S)(I ion /I electron ), where S is a coefficient with the units of 1/torr and is characteristic of particular gauge geometry, electrical parameters and pressure range.
[0003] The operational lifetime of a typical B-A ionization gauge is approximately ten years when the gauge is operated in benign environments. However, these same gauges fail in hours or even minutes when operated at too high a pressure or in gas types that degrade the emission characteristics of the gauge's electron source (hot cathode). Examples of such hot cathode interactions leading to decreased operational lifetime range from degradation of the electron emission properties of the oxide coating on the hot cathode to exposure to water vapor. Degradation of the oxide coating dramatically reduces the number of electrons generated by the cathode, and exposure to water vapor results in the complete burnout of a tungsten cathode.
[0004] Cold cathode gauges come in many varieties. They include the Penning, the magnetron, the inverted magnetron, and the double inverted magnetron. The cold cathode inverted magnetron ionization gauge, sometimes referred to as a glow discharge gauge, also includes a cathode and an anode; however, the cathode is barely heated, and may heat to about a twenty degree Celsius rise over ambient temperature. The initial source of electrons is by a spontaneous emission event, or by a cosmic ray. As the electrons circle about the anode, the electrons ionize gas molecules and atoms through electron impact ionization, and other electrons are released by this event. As the cathode captures the ions, a current is generated in the cathode. This current is used as an indication of gas density and pressure. The capture of ions at the cathode also releases more electrons which are contained by the crossed electric and magnetic fields and sustains the discharge. In this way, a “cloud” of electrons and ions known as a plasma is formed in the ionization volume. However, cold cathode gauges suffer from relatively large inaccuracies due to uncontrolled discharge of electrons and surface phenomena.
SUMMARY OF THE INVENTION
[0005] An ionization gauge or corresponding method in accordance with an embodiment of the present invention eliminates the hot cathode or filament, but maintains the same level of precision of gas density measurements provided by a hot cathode ionization gauge. The ionization gauge includes a cold electron source, a collector electrode disposed in an ionization volume, and a regulated electrostatic shutter. The electrostatic shutter controls the flow of electrons between the electron source and an ionization volume based on the number of electrons in the ionization volume. The collector electrode then collects ions formed by the impact between the electrons and gas molecules in the ionization volume. In another embodiment of the present disclosure, the ionization gauge may also include multiple, or at least two collector electrodes. The collector electrodes may be positioned in the same location or in different locations relative to one another.
[0006] The ionization gauge can include an anode which defines the ionization volume and retains the electrons in a region of the anode. The collector electrode can be disposed within the ionization volume. The ionization gauge can include elements of a Bayard-Alpert type vacuum gauge. The electron source can be an inverted magnetron cold cathode gauge or glow discharge ionization gauge.
[0007] In yet another embodiment of the present disclosure, there is provided an ionization gauge. The ionization gauge has a source that generates electrons and a collector electrode. The collector electrode is disposed in an ionization volume and collects ions. The ionization gauge also has an electrostatic shutter that is configured to control the flow of electrons between the electron source, and the ionization volume. The ionization gauge also has an envelope that surrounds the source. The electrostatic shutter and the envelope permit electrons from a predetermined electric potential region to enter into the ionization volume.
[0008] In another embodiment, the anode of the electron source is connected to ground, and the envelope is connected to a negatively charged voltage potential. This permits electrons that are located near the anode to enter the ionization volume.
[0009] The ionization gauge may also be configured to have an annular ring of an electrostatic shutter (or shutters), which is located near the periphery of the envelope, or end. The electron source can be a cold cathode ionization source, which has an anode connected to a voltage source. The envelope can be grounded. This allows electrons that are located near the envelope to enter the ionization volume.
[0010] In yet another embodiment, there is provided a method of measuring gas pressure. The method generates electrons, and regulates the flow of electrons from a source to the ionization volume. The method also controls the energy of the electrons from the source, and then collects ions. The electron energy can be controlled by operating the anode at a ground potential and operating an envelope that surrounds the electron source at a predetermined negative potential. The electron energy can be controlled by operating the anode at a predetermined voltage, and operating an envelope that surrounds the anode at a ground potential.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0012] FIG. 1 is a schematic view of an ionization gauge according to an embodiment of the present invention;
[0013] FIG. 2 is a flow diagram according to an embodiment of the present invention;
[0014] FIG. 3 is a schematic view of an ionization gauge according to a different embodiment of the present invention having a second collector electrode; and
[0015] FIGS. 4 and 5 show a schematic view of other embodiments of the ionization gauge for controlling electrons to allow electrons from a low potential region to enter the ionization volume.
DETAILED DESCRIPTION OF THE INVENTION
[0016] A description of preferred embodiments of the invention follows.
[0017] As shown in FIG. 1 , an ionization gauge 100 according to an embodiment includes a typical B-A ionization gauge 112 without a hot cathode but with a cold electron source 122 . The B-A ionization gauge 112 may be a nude or non-nude type ionization gauge. The cold electron source 122 may be a cold cathode ionization gauge such as a glow discharge cell, of which one version is the inverted magnetron. The glow discharge cell generates an electron cloud using crossed electrostatic and magnetic fields. Other cold cathode ionization gauges that may be used as the cold electron source 122 include the Penning gauge, magnetron and the double inverted magnetron.
[0018] Generally, the inverted magnetron type gauge has two electrodes with an electric field between them caused by an anode being positive with respect to a cathode. Likewise, the cathode is negative with respect to the anode. The inverted magnetron type gauge is surrounded by a magnet (not shown) which has lines of force going lengthwise through the volume perpendicular to the electric field. Generally, the anode attracts electrons which cannot go directly to the anode due to the crossed magnetic fields. The cathode attracts positively ionized atoms and molecules. The cathode generates electrons when ions impact it, and the cathode is generally sufficiently large so the ions do not miss the cathode during travel. The cold electron source 122 may also be a field emission electron source that includes a cathode or an array of cathodes with a gradient or a sharp point at the emitting end of the cathodes.
[0019] The cold electron source 122 includes an anode 125 that receives power from an anode voltage source 130 . The cold electron source 122 opens into a measurement chamber 119 of the B-A ionization gauge 112 through an electrostatic shutter 120 . The B-A ionization gauge 112 includes a collector electrode 105 and an anode or grid 110 . The grid 110 defines an anode or ionization volume. The grid 110 can take the form of a helical coil grid or a cylindrical mesh grid or any other shape that allows electrons to enter an ionization volume. A grid bias power supply 136 provides a constant positive voltage with reference to ground to the grid 110 . An ammeter 140 connects to the grid 110 and provides an output signal to an electron source control 150 . The electron source control 150 , in turn, provides an output signal to the electrostatic shutter 120 . Finally, the collector electrode 105 connects through an amplifier 160 to an electrometer 175 .
[0020] In operation, molecules and atoms of gas enter the measurement chamber 119 through a vacuum port 117 . The cold electron source 122 generates an electron cloud or plasma of copious amounts of energetic electrons. The electrostatic shutter 120 allows a regulated or controlled quantity of these electrons to exit from the cold electron source 122 into the B-A ionization gauge's measurement chamber 119 by, for example, providing a well-regulated, modulated high voltage power supply pulse at the exit to the cold electron source 122 . Alternatively, instead of a pulse as mentioned above, other configurations may also be possible to allow a controlled or regulated quantity of electrons to exit from the cold electron source 122 to the chamber 119 .
[0021] In another embodiment, a control voltage may vary continuously and the pulse may vary in height, width or shape in order to allow a controlled or regulated quantity of electrons to exit from the cold electron source 122 to the chamber 119 . Various configurations are possible and within the scope of the present disclosure. Most electrons do not strike the grid 110 immediately but pass through the grid 110 and into the ionization volume defined by the grid 110 where they create positive ions through electron impact ionization.
[0022] The ions, once created by electron impact ionization, tend to stay within the grid 110 . The ions formed within the grid 110 are directed to the collector electrode 105 by the electric field produced by a difference in potential between (a) the anode grid 110 at a potential that is positive with respect to ground and (b) the collector electrode 105 which is at a potential which is near ground potential (i.e., negative relative to the anode grid potential). The ions are collected by the collector electrode 105 to provide an ion current in the collector electrode 105 . The collector current is then amplified by the amplifier 160 and provided to an electrometer 175 . The electrometer 175 provides an indication of the magnitude of the collector current that is calibrated in units of pressure.
[0023] The ammeter 140 measures an electron current generated in the grid 110 from electrons that arrive at the grid 110 . This measured current represents the number of electrons being provided to the ionization volume from the cold electron source 122 . The measured current information from the ammeter 140 is provided to an electron source control unit 150 which uses the current information as feedback to control the electrostatic shutter 120 .
[0024] The electrostatic shutter 120 may act as a controlling grid (that is insulated from a mounting) at the port of the attachment of the cold electron source 122 to the ionization envelope 115 . A value of the grid 110 current measured by the ammeter 140 dictates the voltage on the controlling grid, which then controls the quantity of electrons flowing from the cold electron source 122 to the ionization gauge 100 when the controlling pulse occurs. It is envisioned that, in one embodiment, the ammeter 140 provides a signal and then, subsequently, the controlling voltage pulse occurs. The electron source control unit 150 regulates the quantity of electrons supplied to the ionization volume from the cold electron source 122 to ensure optimum ionization.
[0025] FIG. 2 is a flow diagram of a process of measuring a gas pressure 200 according to an embodiment of the present invention. After the process starts ( 205 ), an electron source generates electrons ( 210 ). Then, the flow of electrons between the electron source and an ionization volume is regulated ( 220 ) based on the number of electrons in the ionization volume. Finally, ions formed by impact between the electrons and the gas molecules and atoms in the ionization volume are collected ( 230 ). The process 200 then repeats ( 235 ).
[0026] In another embodiment of the present disclosure, the method 200 may further include filtering the flow of electrons to limit the flow to a predetermined energy range. Other embodiments of the electrostatic shutter are shown in FIGS. 4 and 5 . The filtering can be electrostatic filtering, and a geometry of the gauge can be changed or modulated in order to further assist with filtering. The method 200 may also further include modulating a voltage of the electron source in response to pressure. In yet another embodiment, the method 200 may further include that a gauge geometry may also be modified to produce an electron current in response to a pressure.
[0027] Turning now to FIG. 3 , in a further embodiment of the present disclosure. Here, the Bayard-Alpert ionization gauge 100 includes a second ion collector electrode 105 ′ in addition to the ion collector electrode 105 . Here, the second ion collector electrode 105 ′ is positioned inside the anode grid 110 to assist in better ion collection. The ions, once created by electron impact ionization, tend to stay within the anode grid 110 , while at higher pressures the ions also tend to stay outside the grid 100 . The collector current is then amplified by the amplifier 160 and provided to an electrometer 175 . The electrometer 175 provides an indication of the strength of the collector current that is calibrated in units of pressure.
[0028] Turning now to FIG. 4 , there is shown an alternative embodiment of an ionization gauge 100 that has a cold electron source 122 . The electrostatic shutter 120 of FIG. 1 is replaced with an annular electrostatic shutter generally shown as 120 a and 120 b which is located at the periphery of the opening of the envelope 125 a or end of cold electron source 122 . One electrostatic shutter 120 is also envisioned with portions 120 a and 120 b, and the present disclosure is not limited to any specific number of shutters. The ionization gauge 112 also includes a cold electron source 122 that releases electrons into the ionization envelope 115 . Again, the shutter 120 a, 120 b acts as a controlling grid to envelope 115 ; however, in this embodiment, electrons escape from the cold electron source 122 from a relatively low electrical potential region. This allows electron control in the envelope 115 . FIG. 4 shows a configuration where electrons, from a low potential region, escape from the cold electron source 122 to the ionization volume 119 . Preferably, the cold cathode/glow discharge gauge has the anode 125 at a high voltage which is connected to anode voltage source 130 . Preferably, the anode 125 is housed in a cold cathode envelope 125 a which is connected to the ground. Cold cathode envelope 125 a preferably is a cylindrical shaped member with a circular cross section; however, the cold cathode envelope 125 a is not limited to this shape, and may have a different shape. Thus, electrons near the cathode envelope 125 a escape and are released into the ionization envelope 115 . This allows only electrons, which are located near the cold cathode envelope 125 a to escape. This allows the energy spread of electrons to be controlled, and the ionization gauge 100 releases electrons at a relatively low potential into the ionization envelope 115 .
[0029] Turning to FIG. 5 , there is shown yet another embodiment of the present ionization gauge 100 . In this embodiment, electrons near the anode 125 escape and enter the ionization volume 119 . In this embodiment, the center anode 125 of the cold electron source 122 is connected to ground, while the cold cathode envelope 125 a is operated at a negative, high voltage value, and is connected to anode voltage source 130 . This permits electrons to escape from the cold electron source 122 at a low energy to control the energy spread of electrons by the value of the anode voltage source 130 , and by using an electrostatic shutter 120 .
[0030] 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 scope of the invention encompassed by the appended claims.
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An ionization gauge that eliminates a hot cathode or filament, but maintains a level of precision of gas density measurements approaching that of a hot cathode ionization gauge. The ionization gauge includes a collector electrode disposed in an ionization volume, an electron source without a heated cathode, and an electrostatic shutter that regulates the flow of electrons between the electron source and the ionization volume. The electrostatic shutter controls the flow of electrons based on feedback from an anode defining the ionization volume. The electron source can be a Penning or glow discharge ionization gauge.
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TECHNICAL FIELD
[0001] The present invention relates to an improved form of elongate solar cell and an improved method for fabricating elongate solar cells.
BACKGROUND
[0002] Any discussion of the background art throughout the specification should in no way be considered as an admission that such background art is prior art, nor that such background art is widely known or forms part of the common general knowledge in the field.
[0003] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.
[0004] In this specification, the term “elongate solar cell” refers to a solar cell 100 as shown schematically in FIG. 1 being of generally parallelepiped form with mutually opposed edges 101 and 101 a , mutually opposed faces 103 and 103 a and mutually opposed ends 105 and 105 a . The cell 100 generally has a high aspect ratio in that its length l is substantially greater (typically some tens to hundreds of times larger) than its width w and its thickness t. Additionally, the zo width w of an elongate solar cell 100 is substantially greater (typically four to one hundred times larger) than its thickness t. The length l and width w of an elongate solar cell 100 define the maximum available active or useable surface area for photovoltaic power generation (the active “face” or “faces” 103 and 103 a of the solar cell), whereas the length l and thickness t of an elongate solar cell 100 define the optically inactive longitudinal surfaces or “edges” 101 and 101 a of the cell 100 that are used to make electrical contact to the cell. A typical elongate solar cell is l≈10-120 mm long, w≈0.3-3 mm wide, and t≈10-200 microns thick, although the present invention is applicable to all elongate solar cells and is not to be construed as being limited to elongate solar cells having any particular dimensions.
[0005] Elongate solar cells can be produced by processes such as those described in International Patent Application Publication No. WO 02/45143 (“the Sliver patent application”). That document describes processes for simultaneously producing a large number of thin (generally <150 μm) elongate silicon substrates from a single standard silicon wafer, whereby the number and dimensions of the resulting thin elongate substrates are such that the total useable surface area is greater than that of the original silicon wafer. Such elongate substrates are also referred to as Sliver substrates. The word “SLIVER” is a registered trademark of Origin Energy Solar Pty Ltd, Australian Registration No. 933476. The Sliver patent application also describes processes for forming an individual solar cell from each sliver substrate, the resulting elongate solar cells being referred to as ‘Sliver solar cells’. However, the word ‘sliver’ generally refers to a sliver substrate that may or may not incorporate one or more solar cells.
[0006] In general, elongate solar cells can be single-crystal solar cells or multi-crystalline solar cells formed on elongate substrates using essentially any solar cell manufacturing process. As shown in FIG. 2 , elongate substrates are preferably formed in a batch process by is machining (for example by anisotropic wet chemical etching) a series of parallel elongate rectangular slots or openings 202 of a selected width (w s ) completely through a silicon wafer 204 of thickness w so that the unetched silicon 206 strips with thickness t remaining between the newly formed openings 202 defines a corresponding series of parallel elongate parallelepiped substrates or ‘slivers’ 206 of silicon. The length l of the slots 202 is generally less than, but similar to, the diameter of the wafer 204 so that the elongate substrates or slivers 206 remain joined together by the remaining peripheral portion 208 of the wafer, referred to as the wafer frame 208 . Each elongate substrate 206 is considered to have two longitudinal edges 210 and 210 a with thickness t which are coplanar with the two wafer surfaces, two (newly formed) faces 212 and 212 a perpendicular to the wafer surface with width w (i.e. the same as that of the wafer thickness), and two ends 214 and 214 a , which initially remain attached to the wafer frame 208 . In particular arrangements, the thickness of the elongate substrates (strips of silicon remaining after the machining of the slots) and the slot width are selected for division of the wafer such that the thickness of the wafer (corresponding to the width, w, of the elongate substrate) is greater than the sum of the strip thickness and the slot width (w>t+w s ) so that the total surface area of the faces 212 and 212 a of all the elongate substrates formed by the manufacturing process is greater than that of the surface area of the top and bottom faces of the semiconductor wafer.
[0007] Also as shown in FIG. 2 , solar cells can be partially formed from the elongate substrates 206 while they remain retained by the wafer frame 208 ; the resulting elongate substrates 206 can then be separated from each other and from the wafer frame 208 , and further processing performed if necessary, to provide a set of individual elongate solar cells. A large number of these sliver solar cells can be electrically interconnected and assembled together to form a solar power module, concentrator receiver, or other photovoltaic device.
[0008] When elongate substrates are formed in this way, the transverse width of the elongate slots (w s ) and the thickness (t) of the elongate silicon substrates (slivers) are in the plane of the wafer surface, and each sliver/slot pair effectively requires a surface area of l×w s ×t of the wafer surface, where 1 is the length of the elongate substrate. For example, if the width of the slot and the substrate thickness are both about 0.05 mm, then each sliver/slot pair effectively requires a surface area of 1×0.1 mm of the wafer surface. However, due to the thickness of the silicon wafer w (typically between ≈0.3 to 3 mm), the surface area of each of the two newly formed faces of the sliver (perpendicular to the wafer surface) is l×w (where w ˜0.3 to 3 mm), thus providing an increase in useable surface area of the wafer by a factor of between 5 to 30 relative to the original wafer surface (neglecting any useable surface area of the wafer frame). The thickness of the slot, w s , can be varied between about 0.005 and 0.1 mm, for example, about 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095 or about 0.1 mm. Also, the thickness t of the elongate substrates (strips) in the plane of the wafer surface may also be varied between about 0.001 and about 0.2 mm, for example, about 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, or about 0.2 mm. Also, the thickness of the wafer may also vary between about 0.1 to about 5 mm, for example about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or about 5 mm in accordance with requirements and manufacturing tolerances. Accordingly, the increase in the useable surface area of the wafer may be increased further. The length of the elongate substrates may be similar to that of the diameter of the wafer, or may be less, depending on the orientation of the slots formation (e.g. a plurality of groups of slots may be formed at different orientations and/or length in the wafer to form a corresponding plurality of groups of substrates). The length of the substrate may typically be in the range of about 20 mm to about 100 mm, although longer cells may also be formed, e.g. up to about 150 or 200 mm or more, if larger diameter wavers are used.
[0009] The fabrication of an elongate or Sliver solar cell involves several steps, including the formation of one or more p-n junctions for the collection of photocurrent generated in the device; the passivation of most or all of the surfaces of the silicon strip with a dielectric or insulating layer; and the formation of electrical contacts to the p-type and n-type regions of the device. Additional optional but preferred steps include the application of an antireflection coating to one or both faces in order to reduce the reflection of light from the silicon strips, and the texturing (roughening) of one or more of the faces of each strip in order to reduce the reflection of light and also to confine light within the silicon strip.
[0010] Insulating coatings, usually fabricated from dielectric materials, are placed on most it) surfaces of efficient solar cells for the purpose of decreasing surface recombination of electrons and holes, reducing reflection losses (by acting as an antireflection coating), and preventing metal from contacting silicon except where desired.
[0011] In practice, more than one of the above steps can be effected by a single process step. For example, the application of a layer of silicon nitride by plasma-enhanced chemical vapour deposition (PECVD) can serve to both passivate a silicon surface and also to provide an antireflection coating.
[0012] It is generally desirable to be able to fabricate solar cells with high conversion efficiency. Consequently, it is preferred that the solar cells be made from a material with a high minority carrier diffusion, length, have well-passivated surfaces, and have good optical properties.
[0013] The metal contacts to a solar cell should generally occupy a small area consistent with obtaining adequately low contact resistance. The reason for this is that these contact regions have high minority carrier recombination rates. For a given metal-semiconductor contact area, the amount of recombination can be minimised by heavily doping the surface beneath the metal contact with an appropriate n-type or p-type dopant. However, the heavily doped regions themselves are regions of elevated recombination rates, and so their area should be minimised. In the case of a typical sliver cell, the edges constitute about 5% of the total surface area of the cell. Thus heavily doping and metallising an entire edge meets the criterion that such regions occupy a small fraction of the surface area of the cell.
[0014] The cost of fabricating a solar cell will generally be reduced if the cell fabrication process sequence is short, delivers a high yield of efficient cells, and uses a minimum of consumables and expensive process equipment. For a given wafer throughput, a more complex process will entail a larger fabrication facility, more process equipment, and higher costs for maintenance, consumables, and waste disposal. A long fabrication process will typically have a lower yield than a similar but shorter process.
[0015] As in other applications of semiconductor processing, the processing steps involved in the manufacture of solar cells from semiconductor wafers are often found to be non-ideal in practice, and consequently can give rise to imperfect and/or unintended structures or artefacts, referred to generically herein as “processing defects”, that degrade the performance of the resulting solar cells. For example, some processing defects can cause electrical shunting paths (short circuits) to form between n-type doped regions and p-type doped regions of an elongate solar cell, and/or between the metal contacts to those doped regions. Some processing defects can cause excessive recombination of photogenerated carriers within the cell, thus decreasing the efficiency of the cell. Some processing defects can allow n-type and/or p-type dopants to appear in regions where they were not intended to be. They can also allow metal to contact the semiconductor in unintended regions, which may form shunt paths (short circuits).
[0016] It is desired to provide an elongate solar cell and a method for producing an elongate solar cell that alleviate one or more difficulties of the prior art, or that at least provide a useful alternative.
SUMMARY OF THE INVENTION
[0017] In any of the aspects or arrangements described herein, the apparatus, system or method may also comprise one or more of any of the following either taken alone or in any suitable combination.
[0018] In accordance with a first aspect, there is provided an elongate solar cell. The elongate solar cell may comprise a semiconductor body comprising two mutually opposed faces. At least one of the mutually opposed faces may be an active face for receiving incident light. The semiconductor body may further comprise two mutually opposed edges substantially orthogonal to the mutually opposed faces. The edges may comprise electrical contacts thereon for conducting electrical current generated by the solar cell from the incident light. The electrical contact to at least one of the edges may comprise an electrically conductive material that contacts only a portion of the at least one edge of the semiconductor body to improve the performance of the solar cell.
[0019] In an arrangement of the first aspect, there is provided an elongate solar cell, comprising a semiconductor body comprising two mutually opposed faces, at least one of the faces being an active face for receiving incident light, and two mutually opposed edges substantially orthogonal to the faces, the edges comprising electrical contacts thereon for conducting electrical current generated by the solar cell from the light; wherein the electrical contact to at least one of the edges includes an electrically conductive material that contacts only a fractional portion of the at least one edge of the semiconductor body to improve the performance of the solar cell.
[0020] The fractional portion of the edge contacted by the electrically conductive material may comprise less then 100% of the surface area of the edge and may be less than or substantially less than 99% of the surface area of the edge. In particular arrangements, the electrically conductive material may contact a surface area of the edge comprising less than 100% of the surface area of the edge, and may be between about 1% and about 99%, or alternatively between about, 1% and 95%, 1% and 90%, 1% and 80%, 1% and 70%, 1% and 60%, 1% and 50%, 1% and 40%, 1% and 30%, 1% and 20%, 1% and 10%, 1% and 5%, or between 10% and 90%, 10% and 75%, 10% and 50%, 10% and 25%, 25% and 90%, 25% and 75%, 25% and 50%, 50% and 98%, 50% and 90%, or between about 50% and about 75%. For example, the electrically conductive material may contact about 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or about 99% of the surface area of the edge.
[0021] By arranging for the electrically conductive material to contact only a relatively small portion of the edge of the semiconductor body, the impact of processing defects or other factors that degrade the performance of the solar cell is correspondingly reduced. Thus a solar cell in accordance with the present invention has improved performance relative to an otherwise identical solar cell but in which the electrically conductive material contacts substantially all of the at least one edge of the cell.
[0022] The electrically conductive material contacting the edge of the semiconductor body may be of elongate form and may be substantially centrally disposed along a longitudinal axis of the at least one edge of the semiconductor body. The electrically conductive material may contact the semiconductor body at mutually spaced contact regions of the edge. The regions of the edge not contacted by the electrically conductive material may be contacted by a dielectric material. The contact regions may be of elongate form. The contact regions may be of elongate form, mutually parallel, and may be inclined to a longitudinal axis of the at least one edge. The contact regions may be of non-elongate form and distributed over the at least one edge.
[0023] In a particular arrangement, the electrically conductive material may contact less than about 100%, and may contact between about 0.01% and about 100% or between about 0.01% and 99%, and may contact about 0.01%, 0.05%, 1%, 5%, 10%, 25%, 50%, 75%, 90%, 95%, or about 99% of the surface area of the edge of the semiconductor body (where the edge surface area is the length, l, of the elongate body multiplied by its thickness, t).
[0024] In a further arrangement, the electrically conductive material may contact approximately equal to or less than about one half (≈≦50%) of the surface area of the edge of the semiconductor body. Alternatively, the electrically conductive material may contact substantially less than one half (<<50%) of the surface area of the edge of the semiconductor body. The electrically conductive material may contact less than or substantially less than about 10% (≈<10% or <<10%) of the surface area of the edge of the semiconductor body. The electrically conductive material may contact less than or substantially less than about 1% (≈<1% or <<1%) of the surface area of the edge of the semiconductor body. The electrically conductive material may contact between about 0.01% and about 10% of the surface area of the edge of the semiconductor body, or alternatively between about 0.01% and about 5%, or between 0.01% to 10%, 0.01% to 25%, 0.01% to 50%, 1% to 5%, 1% to 10%, 1%, to 25%, 1% to 50%, 5% to 10%, 5% to 25%, 5% to 50%, 10% to 25%, 10% to 50%, or between about 25% to about 50%, for example about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or about 50%.
[0025] In a still further arrangement, the electrically conductive material may contact approximately equal to or greater than about one half (≈≧50%) of the surface area of the edge of the semiconductor body. Alternatively, the electrically conductive material may contact substantially greater than one half (>>50%) of the surface area of the edge of the semiconductor body. The electrically conductive material may contact greater than or substantially greater than about 75% (≈>75% or >>75%) of the surface area of the edge of the semiconductor body. The electrically conductive material may contact less than or substantially greater than about 90% (≈>90% or >>90%) of the surface area of the edge of the semiconductor body. The electrically conductive material may contact between about 50% and about 99% of the surface area of the edge of the semiconductor body, or alternatively between about 50% and about 95%, or between 50% to 90%, 50% to 75%, 75% to 99%, 75% to 90%, 75% to 80%, 80%, to 99%, 80% to 95%, 80% to 90%, 90% to 99%, 90% to 95% or between about 95% to about 99%, for example about 50%, 55%, 60%, 65%, 7%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 4%, 95%, 96%, 97%, 98%, or about 99%.
[0026] In a second aspect, there is provided a process for producing an elongate solar cell. The elongate solar cell may comprise a semiconductor body comprising two mutually opposed faces. At least one of the faces may be an active face for receiving incident light. The elongate solar cell may further comprise two mutually opposed edges substantially orthogonal to the faces. The edges may comprise electrical contacts thereon for conducting electrical current generated by the solar cell from the light. The process for producing the elongate solar cell may comprise forming an electrical contact to at least one of the edges The electrical contact may comprise an electrically conductive material. The electrically conductive material may contact only a fractional portion of the at least one edge of the semiconductor body to improve the performance of the solar cell. The fractional portion may be a relatively small portion of the at least one edge.
[0027] In an arrangement of the second aspect, there is provided a process for producing an elongate solar cell, the elongate solar cell comprising a semiconductor body comprising two mutually opposed faces, at least one of the faces being an active face for receiving incident light, and two mutually opposed edges substantially orthogonal to the faces, the edges comprising electrical contacts thereon for conducting electrical current generated by the solar cell from the light; the process comprising forming an electrical contact to at least one of the edges, the electrical contact comprising an electrically conductive material that contacts only a relatively small portion of the at least one edge of the semiconductor body to improve the performance of the solar cell.
[0028] The process may further comprise forming the electrically conductive material in elongate form. The elongate formation of electrically conductive material may be substantially centrally disposed along a longitudinal axis of the at least one edge of the semiconductor body.
[0029] In a particular arrangement, the electrically conductive material may contact the semiconductor body at mutually spaced contact regions of the edge. The regions of the edge not contacted by the electrically conductive material may be contacted by a dielectric material. The contact regions may be of elongate form. The contact regions may be of elongate form, mutually parallel. The contact regions may be inclined to a longitudinal axis of the at least one edge. Alternatively, the contact regions may be of non-elongate form and may be distributed over the at least one edge.
[0030] The process may further comprise forming a dielectric or electrically insulating coating on the at least one edge of the semiconductor body. The coating may comprise one or more openings therein to expose a fractional portion of the at least one edge of the semiconductor body. The process may further comprise forming the electrically conductive material in the one or more openings to contact respective contact regions of the at least one edge exposed by the openings. The forming of the coating may comprise forming the one or more openings in an existing dielectric or electrically insulating coating. The coating may comprise a plurality of openings therein to expose respective regions of the at least one edge. The openings may be created using either a laser, a mechanical scribing process, an etch paste, or etching techniques such dry etch techniques, e.g. reactive ion etching or plasma etching, or other etching techniques as would be appreciated by the skilled addressee. The openings may be formed by any other means capable to remove portions of the coating including, for example, short pulses of ultra violet light generated by a laser, or by application of an etching paste to selectively remove portions of the coating without causing significant damage to the underlying semiconductor body.
[0031] The electrically conductive material may be deposited either by vacuum evaporation, screen printing, electroplating, electroless plating, inkjet printing, aerosol printing, or another deposition process. In some arrangements, the deposition method may be a directional process.
[0032] In the directional deposition process the electrically conductive material may be directed substantially perpendicular to the plane of the surface upon which the electrically conductive material is to be deposited (typically the edge of the cell). In other arrangements, electrically conductive material may be directed at an inclined angle to the surface upon which the electrically conductive material is to be deposited (typically the edge of the cell). In the inclined directional process, the electrically conductive material may be deposited both on the edge of the cell, and also on a portion of a contiguous or adjacent surface to the edge, such as for example at least one face of the cell.
[0033] The process may further comprise forming heterojunction electrical contacts within the openings.
[0034] The semiconductor body may comprise a background doping of a first polarity type (either p-type or n-type), and only one of the edges of the semiconductor body may comprise a surface doping layer of a second polarity type opposite to the first polarity type (either n-type or p-type respectively), wherein the openings are formed only on the edge having the surface doping layer of the second polarity type.
[0035] Alternatively, the semiconductor body may comprise a background doping of a first polarity type (either p-type or n-type), and only one of the edges of the semiconductor body may comprise a surface doping layer of the first polarity type (either p-type or n-type), wherein the openings are formed only on the edge having the surface doping layer of the first polarity type.
[0036] The openings may be formed as a plurality of substantially non-elongate openings. Alternatively, the openings may be formed as a plurality of elongate openings having longitudinal axes inclined to a longitudinal axis of the at least one edge.
[0037] The electrically conductive material may be a metal selected to form: 1) a good electrical contact to the one or more regions of the at least one edge of the semiconductor body exposed by the one or more openings, the one or more exposed regions comprising a surface doping layer of a first polarity type (either p-type or n-type) and a first dopant concentration; but 2) poor electrical contact to any regions exposed by any unintended openings in the coating and comprising a second doping concentration substantially different to the first doping concentration and/or comprising a surface doping layer of a second polarity type opposite to the first polarity type (either n-type or p-type respectively). The electrically conductive material of any one of the aspects of the invention disclosed herein may be a metal selected from the group comprising cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), titanium (Ti), silver (Ag), aluminium (Al) or other suitable alternative as would be appreciated by the skilled addressee. Alternatively, the metal may be a compound or combination comprising, but not limited to, one or more metals selected from the group of Co, Ni, Pd, Pt, Ti, Ag, Al or other suitable metal.
[0038] The openings may be formed by depositing the electrically conductive material over the coating, and driving the electrically conductive material through the coating at mutually spaced locations to form the openings. The electrically conductive material may be driven through the coating only at mutually spaced regions of the coating by localised heating by a process comprising selectively heating corresponding mutually spaced regions of the electrically conductive material. The localised heating may be achieved using a directed laser beam.
[0039] Alternatively, the electrically conductive material may be deposited only at mutually spaced regions on the coating. This allows the electrically conductive material to be locally driven through the coating using a process of uniform heating such as furnace heating, for example.
[0040] The process may further comprise selectively doping only those regions of the at least one surface of the semiconductor body exposed by the openings, and forming the electrically conductive material to contact the resulting doped regions. The doped regions may intersect or abut at least one of the faces of the semiconductor body along only a fractional portion of the intersection of the at least one face with at least one corresponding edge of the semiconductor body to reduce the likelihood of the doped regions forming an electrical short to a doped region of the at least one corresponding edge. The fractional portion may be a relatively small portion of the intersection of the at least one face with at least one corresponding edge of the semiconductor body.
[0041] Advantageously, the electrically conductive material may include a dopant species, and the contact regions may be doped by selectively heating corresponding regions of the electrically conductive material formed over the dielectric coating to selectively drive the heated regions of the electrically conductive material through the dielectric coating to contact the edge of the semiconductor body and to drive the dopant species into the semiconductor body.
[0042] Alternatively, the electrically conductive material may include a dopant species, and zo the contact regions may be doped by selectively depositing the electrically conductive material at mutually spaced locations on the dielectric coating, and subsequently heating the electrically conductive material to drive it through the dielectric coating to contact the edge of the semiconductor body and to drive the dopant species into the semiconductor body.
[0043] Alternatively, the contact regions may be doped by laser chemical processing utilising a liquid-jet-guided laser beam in conjunction with a jet-liquid containing the desired dopant atoms. The liquid-jet-guided laser beam locally forms openings in the dielectric coating and at the same time dopes the exposed regions of the semiconductor body.
[0044] Alternatively, the contact regions may be doped by locally heating a material containing a dopant species using a laser without liquid guiding to drive the dopant species into the semiconductor body. If a dielectric layer is disposed between the doping material and the semiconductor body, it is found that the laser disrupts the dielectric layer to allow the dopant species to dope the corresponding regions of the semiconductor body.
[0045] The faces of each elongate solar cell may be doped with a dopant of a first polarity (either p-type or n-type), and an edge of the elongate solar cell doped discontinuously in mutually spaced doped regions with a dopant of a second polarity opposite to the first polarity (either n-type or p-type respectively), wherein the doped regions of the faces and the doped regions of the edge intersect or abut over only a relatively small portion of the length of each intersection of the edge and the corresponding face.
[0046] According to a third aspect, there is provided a process for producing an elongate solar cell. The elongate solar cell may comprise a semiconductor body comprising two mutually opposed faces. At least one of the faces may be an active face for receiving incident light. The elongate solar cell may further comprise two mutually opposed edges substantially orthogonal to the faces. The edges may comprise electrical contacts thereon for conducting electrical current generated by the solar cell from the light. The process may comprise forming a plurality of mutually spaced doped regions in at least one of the edges so that the at least one edge is doped discontinuously to improve the performance of the solar cell.
[0047] In an arrangement of the third aspect, there is provided a process for producing an elongate solar cell, the elongate solar cell comprising a semiconductor body comprising two mutually opposed faces, at least one of the faces being an active face for receiving incident light, and two mutually opposed edges substantially orthogonal to the faces, the edges comprising electrical contacts thereon for conducting electrical current generated by the solar cell from the light; the process comprising forming a plurality of mutually spaced doped regions in at least one of the edges so that the at least one edge is doped discontinuously to improve the performance of the solar cell.
[0048] The at least one active face may comprise a doped region of a first polarity (either p-type or n-type) and the at least one edge is doped to form doped regions of a second polarity opposite to the first polarity (either n-type or p-type respectively), wherein the doped region of the at least one face intersects or abuts at least one of the oppositely doped regions of the at least one edge. The doped regions in the at least one edge may occupy only a fractional portion of the at least one edge.
[0049] In a particular arrangement, the doped regions in the at least one edge may occupy less than about 100% of the at least one edge, and may occupy between about 0.01% and about 100% or between about 0.01% and 99%, and may contact about 0.01%, 0.05%, 1%, 5%, 10%, 25%, 50%, 75%, 90%, 95%, or about 99% of the at least one edge.
[0050] In a further arrangement, the doped regions in the at least one edge may occupy a relatively small portion of the at least one edge and may occupy approximately equal to or less than about one half (≈≦50%) of the at least one edge.
[0051] Alternatively, the electrically conductive material may contact substantially less than one half (<<50%) of the surface area of at least one edge of the semiconductor body. The electrically conductive material may contact less than or substantially less than about 10% (≈<10% or <<10%) of the surface area of the at least one edge of the semiconductor body. The electrically conductive material may contact less than or substantially less than about 1% (≈<1% or <<1%) of the at least one edge.
[0052] In a still further arrangement, the doped regions in the at least one edge may occupy a relatively large portion of the at least one edge and may occupy approximately equal to or greater than about one half (≈≧50%) of the at least one edge.
[0053] Alternatively, the electrically conductive material may contact substantially greater than one half (>>50%) of the surface area of at least one edge of the semiconductor body. The electrically conductive material may contact greater than or substantially greater than about 75% (≈>75% or >>75%) of the surface area of the at least one edge of the semiconductor body. The electrically conductive material may contact greater than or substantially greater than about 90% (≈>90% or >>90%) of the surface area of the edge of the semiconductor body.
[0054] The doped regions in the at least one edge may form respective p-n junctions with the doped region of the corresponding at least one face.
[0055] The process may further comprise heating the elongate solar cell to lower the surface concentration of at least one of the doped regions of the faces and the doped regions of the at least one edge. The heating may reduce the reverse breakdown voltage of the p-n junctions.
[0056] According to a fourth aspect, there is also provided an elongate solar cell produced by any one of the above aspects.
[0057] According to a fifth aspect, there is provided an elongate solar cell. The elongate solar cell may comprise a semiconductor body comprising two mutually opposed faces. At least one of the faces may be an active face for receiving incident light. The elongate solar cell may further comprise two mutually opposed edges substantially orthogonal to the faces. The edges may comprise electrical contacts thereon for conducting electrical current generated by the solar cell from the light. At least one of the edges of the elongate solar cell may comprise a plurality of mutually spaced doped regions so that the at least one edge is doped discontinuously to improve the performance of the solar cell.
[0058] In an arrangement of the fifth aspect, there is provided an elongate solar cell, the to elongate solar cell comprising a semiconductor body comprising two mutually opposed faces, at least one of the faces being an active face for receiving incident light, and two mutually opposed edges substantially orthogonal to the faces, the edges comprising electrical contacts thereon for conducting electrical current generated by the solar cell from the light; wherein at least one of the edges of the elongate solar cell comprises a plurality of mutually spaced doped regions so that the at least one edge is doped discontinuously to improve the performance of the solar cell.
[0059] The at least one active face may comprise a doped region of a first polarity (either p-type or n-type) and at least one of the edges is doped to form doped regions of a second polarity opposite to the first polarity (either n-type or p-type respectively), wherein the doped region of the at least one face intersects or abuts at least one of the doped regions of the at least one edge. The doped regions in the at least one edge may occupy a fractional portion of the at least one edge. The fractional portion may comprise less than 100% of the surface area of the at least one edge. The fractional portion may comprise between about 0.01% and about 99% of the surface area of the at least one edge. The fractional portion may comprise between about 0.01% and about 50% of the surface area of the at least one edge. The fractional portion may comprise between about 50% and about 99% of the surface area of the at least one edge. The doped regions in the at least one edge may form respective p-n junctions with the doped region of the corresponding at least one face.
[0060] It is an object of the present invention to substantially overcome or at least ameliorate one or more of the disadvantages of the prior art, or at least to provide a useful alternative to existing electrical contacts for elongate solar cells.
BRIEF DESCRIPTION OF THE DRAWINGS
[0061] Arrangements of the elongate solar cells will now be described, by way of example only, with reference to the accompanying drawings, wherein:
[0062] FIG. 1 is a schematic perspective view of an isolated elongate solar cell, showing a section line A-A′;
[0063] FIG. 2 is a schematic perspective view of a set of prior art elongate semiconductor bodies or substrates retained within a semiconductor wafer frame, a quarter of which has been removed in order to view half of the elongate substrates;
[0064] FIG. 3 is a schematic cross-sectional view of an elongate solar cell (through the to section line A-A′ shown in FIG. 1 ) during production (prior to formation of the electrical contacts on the edges of the cell), illustrating the differently doped surface layers coated with a dielectric (typically SiO 2 , where the semiconductor is Si);
[0065] FIGS. 4A to 4C are schematic cross-sectional views of the top-left corner of an idealised elongate solar cell at different stages of its production;
[0066] FIGS. 5A to 5C are schematic cross-sectional views corresponding to FIGS. 4A to 4C , but for a typical actual (i.e., non-idealised) elongate solar cell;
[0067] FIG. 6A is a schematic depiction of three (idealised) example cell structure options with full edge width metallic contacts for minimising the probability of shunting by the contact;
[0068] FIG. 6B is a schematic depiction of two (idealised) example cell structure options with fractional edge metallic contacts for minimising the probability of shunting by the contact;
[0069] FIG. 7 is a schematic illustration of the angled deposition of metal on elongate substrates;
[0070] FIG. 8 is a view of intermittent openings in a surface insulating dielectric layer, in this case orthogonal to the long axis of each sliver;
[0071] FIG. 9 is a view of a face and edge of a cell before (LHS) and after (RHS) thermal treatment, showing the n-type face doping extends onto the surface of the edge, causing a short circuit to appear between n and p type regions after metallisation, and the effect of thermal treatment to avoid the short-circuit;
[0072] FIG. 10 is a schematic diagram showing perspective and plan views of an edge of an elongate semiconductor body that is selectively doped along an elongate region centrally disposed along the longitudinal axis of the edge and spaced from the two faces of the semiconductor body that intersect the edge;
[0073] FIG. 11 is a schematic diagram showing a defect in the form of a pinhole in a dielectric coating causing an electrical short circuit between an oppositely doped edge and face, following angled evaporation of a metal contact. If the metal is discontinuous along the length of the edge, then the probability of including a pinhole within one of the metallised regions is correspondingly reduced
[0074] FIGS. 12A to 12C are schematic cross-sectional views of the edge of an elongate solar cell at different stages of its production to form a fractional edge contact;
[0075] FIGS. 13A to 13E are schematic cross-sectional views of the edge of an elongate solar cell depicting alternative fractional edge contacts;
[0076] FIGS. 14A to 14F are schematic cross-sectional views of a method for forming an elongate solar cell having fractional edge contacts.
DEFINITIONS
[0077] The following definitions are provided as general definitions and should in no way limit the scope of the present invention to those terms alone, but are put forth for a better understanding of the following description.
[0078] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention belongs. For the purposes of the present invention, the following terms are defined below.
[0079] The articles “a” and “an” are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the article. By way of example, “an element” refers to one element or more than one element.
[0080] The term “about” is used herein to refer to quantities that vary by as much as 30%, preferably by as much as 20%, and more preferably by as much as 10% to a reference quantity.
[0081] Throughout this specification, unless the context requires otherwise, the words “comprise”, “comprises” and “comprising” will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements.
[0082] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are described. It will be appreciated that the methods, apparatus and systems described herein may be implemented in a variety of ways and for a variety of purposes. The description here is by way of example only.
DETAILED DESCRIPTION
[0083] As described above, when forming elongate or sliver solar cells from a wafer by etching parallel slots through a semiconductor wafer, the anisotropic etching process can cause undesirable structures that increase the probability that metal simultaneously contacts both n-type and p-type regions, thus causing an electrical shunt that short circuits the solar cell, thus degrading its efficiency or even rendering it inoperative.
[0084] For example, FIG. 3 is a schematic cross-sectional view through a typical elongate solar cell 300 during its production prior to formation of the electrical contacts on edges 101 and 101 a of the cell (the cross-section being through the section line A-A′ shown in FIG. 1 ), with both faces 103 and 103 a and both edges 101 and 101 a of the cell being coated with a layer of electrical insulator or dielectric 301 . Suitable fractional edge electrical contacts for cell 300 are depicted with reference to FIGS. 6B , 8 , 9 , 10 , 12 C, 13 A to 13 E and 14 E and 14 F.
[0085] In the usual case where the solar cells are formed from the semiconductor silicon, the dielectric 301 is often SiO 2 . Beneath the dielectric coating, the two opposed faces 103 and 103 a of the cell 300 are lightly doped with a dopant species 303 of the opposite polarity type to that of the background doping of the silicon wafer from which the cell was formed. Typically, the starting wafer is lightly doped with a p-type dopant (e.g. boron), and the faces 303 are lightly doped with an n-type dopant (e.g. phosphorus). One of the two opposed edges 305 of the cell (the lower edge in FIG. 3 ) is also doped with the same dopant species (e.g. phosphorus) used to dope the two faces of the cell, but to a much higher concentration to facilitate a good Ohmic electrical contact to the cell. The other edge 307 of the cell is fairly heavily doped with a p-type dopant dopant species (e.g. boron) of the opposite polarity type to provide a highly doped p-type surface layer to facilitate good Ohmic contact to that edge. Alternatively, the starting wafer may be lightly doped with an n-type dopant (e.g. phosphorus), and the faces 303 are lightly p-doped with a p-type dopant (e.g. boron). One of the two opposed edges 305 of the cell (the lower edge in FIG. 3 ) is also doped with the same p-type dopant species (e.g. boron) used to dope the two faces of the cell, but to a much higher concentration to facilitate a good Ohmic electrical contact to the cell. The other edge 307 of the cell is fairly heavily doped with a n-type dopant species (e.g. phosphorus) of the opposite polarity type to provide a highly doped p-type surface layer to facilitate good Ohmic contact to that edge 307 . Alternative n-type dopants may also be used instead of phosphorus, for example arsenic; and alternative p-type dopants may also be used instead of boron, for example gallium.
[0086] Starting with this structure, subsequent process steps remove the dielectric coating 301 to from the edges and deposit an electrically conductive material (usually a metal) onto the exposed highly doped edge surfaces in order to make good, low resistance electrical contacts to the cell. FIGS. 4A to 4C are schematic cross-sectional for an idealised elongate solar cell at different stages of its production which illustrate these steps, namely: FIG. 4 A—just after formation of a dielectric coating; FIG. 4 B—just after removal of the top-facing portion of the dielectric is coating; and FIG. 4 C—after formation of an electrically conductive material (typically metal deposition) on the exposed surfaces of the solar cell FIGS. 4A to 4C show only the top-left corner of the cell of FIG. 3 , as indicated by the dashed circles 310 in FIG. 3 .
[0087] In a typical process, starting with the structure of FIG. 3 , the edges 101 and faces 103 are coated with the dielectric 301 . A corner detail 310 of the cell cross section is shown in FIG. 4A FIG. 4A for instructional purposes. A subtractive process (which may be a directional process, for example, reactive ion etching or plasma etching) is applied from the top 401 of FIG. 4A to remove the dielectric 301 from only the top-facing surfaces (i.e., the edges), whilst leaving the coating 301 on the faces 403 , resulting in the structure shown in FIG. 4B . Next, a deposition process (which may be a directional process, for example, vacuum evaporation) is used to deposit the contact metal 407 as shown in FIG. 4C onto the exposed highly doped p-type edge, thus forming a good Ohmic contact to that edge.
[0088] However, FIGS. 4A to 4C shown an idealised structure wherein the edge 401 and face 403 are perfectly orthogonal and abut one another. In practice, and in particular where the elongate substrate from which the cell is formed is formed by anisotropic etching as described in the sliver patent application, as shown in FIG. 5A the edge 501 and face 503 of many elongate solar cells in a given wafer do not meet at a right angle along the entire intersection of the edge and face, but instead, some regions are joined by an intermediate surface 505 that is an artefact of the (imperfectly selective) etching process used to form the elongate semiconductor body of the cell. It has been found that, during typical practical manufacturing processes, if the same steps are repeated to remove the dielectric layer from the edge 501 then intermediate edge 505 a exposes the n-type doping on the face 503 . Depositing a metal contact 507 onto the edge, as is apparent from FIG. 5C , the initial intermediate surface 505 causes the p-type edge 501 and the n-type face 503 to become short-circuited by the overlaying metal contact layer 507 (compare the idealised structure of FIG. 4C where shorting does not occur). Moreover, a variety of different geometrical shapes can arise at such processing defects, and the particular processing defect illustrated in FIGS. 5A to 5C is only one example of these.
[0089] Because the orientation of the intermediate surface 505 is intermediate between the orthogonal orientations of the (vertical) face 503 and (horizontal) edge 501 , highly directional additive and subtractive processes such as reactive ion etching, vacuum evaporation of metal, or laser processing that are intended to act only upon the horizontal surfaces (e.g. edge 501 as shown in FIGS. 4A to 4C ) will also act upon the intermediate surface 505 .
[0090] A consequence of this is that, when the dielectric is removed from the upwardly facing p-type edge surface 501 , it is also removed from the n-type intermediate surface 505 , as shown in FIG. 5B to expose the underlying n-type material (surface 505 a ). Similarly, when the contact metal 507 is deposited, it is deposited not only onto the exposed p-type surface of the edge, but also onto the exposed n-type intermediate surface 505 a , as shown in FIG. 5C . It will be apparent that this results in the p-type edge and the n-type face becoming short-circuited by the overlaying metal layer 507 (compared with the idealised structure of FIG. 4C where shorting does not occur).
[0091] Additionally, pinholes in dielectric materials can form at any stage of the processing of a cell, and can cause a variety of problems, including doping unintended regions or electrical short circuits forming through the pinholes. This situation is depicted schematically in FIG. 11 (idealised) where the pinhole 1101 in the dielectric layer 1103 ( a ) causes a short circuit between the p-type edge and the n-type face when the metal contact layer 1005 is added (b). The use of discontinuous, mutually spaced doping regions, metallisations, openings, and dielectric regions as described herein reduce the probability of including a pinhole in doped or electrically contacted regions.
[0092] Therefore, cell structure and metallic contact designs must be considered with the aim of separating the metallic contacts from the doped semiconductor contact/junction layers. A selection of cell structure options (idealised) for counteracting the above shorting issues induced during process are depicted in FIG. 6A . Cell structures 610 , 620 , and 630 depict options whereby the metal contact ( 615 , 625 , & 635 respectively) to the doped emitter region ( 611 , 621 , & 631 respectively) is sufficiently separated from the doped base region ( 613 , 623 , & 633 respectively) such that shorting is unlikely to occur. In each of cell structure options 610 , 620 , and 630 , the metal contact ( 615 , 625 , & 635 respectively) covers the entire edge of the elongate cells. There still may be concerns using these cell structures of shunting occurring during typical manufacturing processes as discussed above and/or due to other imperfections that are common in practice which may cause a shunt. For example, metal 635 in cell structure 630 may be extended further along the cell face, where possible pinholes described above will cause formation of a shunt. Generally by reducing the area coverage of the metal (i.e. by using a fractional contact) there is a chance to reduce the probability that these imperfections cause a shunt.
[0093] The aspects and arrangements of the elongate solar cells and manufacturing processing methods for obtaining these as described herein mitigate these and other forms of undesirable processing artefacts or processing defects that adversely affect the performance of elongate solar cells. This is achieved by forming the electrical contact to at least one of the edges of each cell so that it contacts only a fractional portion of the edge of the elongate substrate/solar cell, in some cases only a relatively small portion, thus reducing the impact of such defects and thereby improving the performance of the elongate solar cell.
[0094] In contrast, to the cell structures described above, cell structure options 640 (with active faces 644 and 644 a ) and 650 (with active faces 654 and 654 a ) depict the metallic base contact ( 645 & 655 respectively) contacting only a fraction ( 647 & 657 respectively) of the base region ( 641 & 651 respectively) on the edge ( 642 & 652 respectively) of the cell. The fraction of the base region contacted by the metallic contact may vary between 0.01% of the surface area of the edge of the cell to just less than 100% of the surface area (e.g. about 98-90%). In this and similar arrangements, the fractional portion of the edge which is contacted by the metal may be between about 1% and about 99% of the total surface area of the edge. For example, the metallic contact may contact with about 1%, 5%, 10%, 20%, 25%, 35%, 50%, 60%, 70%, 80%, 90% 95%, 98% or about 99% of the surface area of the edge. Cell structure 650 also has additional advantages since the base and emitter diffusion regions ( 651 and 653 respectively) are abutting which provides reverse breakdown protection for the cell.
[0095] Aspects and arrangements of the elongate solar cells are described herein in the context of elongate solar cells formed by anisotropic chemical etching of p-type silicon wafers having a thickness of 0.3-2 mm, although wafers with thickness in the range of about 0.1 to about 5 mm can also be used. However, it should be understood that the invention can also be applied to elongate solar cells made by other means, from other semiconductors, and/or doped using other dopant species and/or using different doping configurations to those described herein, which have been selected because they represent the most typical arrangements used today. For example, the n-type and p-type wafers and doped diffusion regions in the structures and example disclosed herein can be interchanged simply by replacing “p-type” with “n-type” and vice versa to obtain a solar cell with emitter area of the different polarities.
[0096] In a particular arrangement as depicted in FIG. 8 , a fractional metallic contact to an edge 101 can be achieved by forming one or more openings 801 (also referred to as ‘windows’) is in the dielectric coating 803 (rather than removing the entire coating on the edge) of the slivers and then depositing the contact metal (not shown) onto the resulting structure so that the metal only contacts the edge 101 and the intermediate surface in those exposed regions 801 .
[0097] In a further, an alignment technique such as photolithography can be used to confine electrical contact to the cell edges 101 entirely to the centre of each edge, so that the contact does not intersect with the face at all, the complementary region of the edges around the contact remaining coated with the dielectric. In this and similar arrangements, the fractional portion of the edge which is contacted by the metal may be less than 100% of the surface area of the edge, for example between about 0.01% and about 99% of the total surface area of the edge. For example, the metallic contact may contact with about 0.01%, 0.05%, 1%, 5%, 10%, 20%, 25%, 35%, 50%, 60%, 70%, 80%, 90% 95% 98% or about 99% of the surface area of the edge, where the edge surface area is the length, l, of the elongate cell multiplied by its thickness, t.
[0098] In addition, as depicted in cell structure 640 of FIG. 6B , the base doping region 641 on the edge 642 can be confined entirely to the centre of the edge 642 , so that the edge-doping does not intersect with the doped emitter regions 643 on the cell faces 643 at all.
[0099] In a further arrangement, a process for fabricating the cell structures 650 of FIG. 6B is depicted in FIGS. 12A to 12C . A typical actual structure with imperfect corners between the edge 1201 and face 1203 (and also face 1204 ), similar to FIGS. 5A to 5C . As before, the cell is coated with a dielectric coating 301 on both the edges and the faces ( FIG. 12A ). In FIG. 12B a direction subtractive process has been used to remove a portion of the dielectric coating from the edge 1201 to create a void 1210 which exposes a fractional portion of the surface area of the doped base region 1205 on edge 1201 . Next, a directional deposition process is used to deposit the metal contact material onto the edge 1201 of the cell, whereby the metal fills the void 1210 and therefore contacts the base region 1205 in only a fractional portion of the surface area of the edge 1201 . As depicted in FIGS. 13A to 13C the fractional portion of the base region 1305 may be used to create metal contact area according to requirements, for example to just less than 100% of the surface area of the top surface of the cell ( FIG. 13A ), to about 50% of the surface area of the top surface top ( FIG. 13B ), or only a relatively small portion of the surface area of the top surface ( FIG. 13C ), or alternatively any fractional portion therebetween. Alternatively, multiple contact regions may be formed as depicted in FIGS. 13D and 13E showing two and three regions respectively where the metal contacts with the base region 1305 of the cell. In all cases, the fractional portion of the edge which is contacted by the metal may be less than 100% of the surface area of the edge, for example between about 0.01% and about 99% of the total surface area of the edge. For example, the metallic contact may contact with about 0.01%, 0.05%, 1%, 5%, 10%, 20%, 25%, 35%, 50%, 60%, 70%, 80%, 90% 95% 98% or about 99% of the surface area of the edge.
[0100] However, these arrangements also have some disadvantages. In particular, an alignment step is required to ensure that the openings in the insulating dielectric for the electrical contacts are midway between, and parallel to, the edges of each cell. Options for aligning and forming these openings are reduced if this step is performed after etching of the slots between the cells, because traditional techniques such as photolithography can no longer be readily used. Additionally, some type of processing defects are quite large, and can extend well into the edge region, and so the problem of defects may persist.
[0101] To alleviate these shortcomings, other embodiments reduce the effects of processing defects not so much by avoiding those regions of the edge located at or near the cell faces, but rather by reducing the total proportion of the edge surface to which contact is made, thereby correspondingly reducing the number of defects that are exposed to the electrical contacts. The regions of the edge surfaces not contacted remain coated by the dielectric to reduce their potential for deleterious effects.
[0102] Moreover, rather than contact each edge at a single (but long) contact region, in some embodiments each edge is contacted at a plurality of (shorter/smaller) contact regions in order to relax or avoid any need to precisely align the desired pattern of contact regions with the edges of the elongate substrates.
[0103] For example, in one embodiment, many small openings are formed in the dielectric on at least one of the edges of each elongate cell, so that the combined area of these openings comprises only a fractional portion of the total surface area of the edge. In this case, the process may be well suited where the fractional portion is only a small portion of the total surface area, for example less than about 30% to about 50%, of the total area of the edge. The fraction portion may be higher, i.e. greater than 50% to about 99%, with the trade of the yield of cells without defects will be lower. For example, where the fractional portion is about 10% of the total surface area of the edge, the expected reduction of the reject rate of cells due to specific defects will be ×10. Similarly, where the fractional portion is about 90% of the total surface area of the edge, the expected reduction of the reject rate of cells due to specific defects will be only about 10%, that is, the reduction of the overall exposure to defects will be lower as the fractional portion of the edge contacted increases. Subsequently, a metal is deposited over the dielectric and the openings so that the metal contacts the doped silicon only in the regions exposed by the openings, thereby reducing the overall exposure of the electrical contact to processing defects by about a factor dependent on the fraction of the surface area exposed by the openings (e.g. where the total exposed surface area is only about 10%, this process would reduce the overall exposure of the electrical contact by a factor of ten, assuming the openings are uniformly distributed).
[0104] Such contacts to only a relatively small portion (e.g. less than about 10%) of each edge are nevertheless still sufficient to provide reliable low resistance electrical contacts, provided that the doping concentration in the contacted semiconductor regions is high enough to sufficiently reduce contact resistance losses. This is easily achieved by doping the relevant regions of the edges heavily to achieve a sufficient surface doping concentrations, according to well-established standard semiconductor process protocols, which differ for contacts to n and p type regions. Typical boron (p-type) and phosphorus (n-type) surface doping density is in the range 10 18 -10 21 cm −3 . Alternatively, heterojunction contacts can be formed. Heterojunctions are well known methods of contacting a semiconductor, and include a different semiconductor material than the semiconductor substrate, whereby the two semiconductors have different work functions. Typically, a heterojunction contact will be fabricated from a wider bandgap semiconductor. An example that has been used for silicon solar cells comprise crystalline and amorphous silicon material.
[0105] The openings in the dielectric coating can have essentially any shape, but are preferably in the form of small dots or lines. In the latter case, if the lines are inclined relative to the longitudinal axis of each edge, then they will occupy a known proportion of the cell edge that depends only upon the width and pitch of the lines. The spacing of the dots or lines can be selected by performing standard electrical resistance calculations in order to avoid excessive series resistance associated with the transport of electrons and holes to the electrical contacts.
Patterning
[0106] Various methods can be used to create diffused and metallised patterns of openings (windows) in insulating or dielectric layers or coatings. It is straightforward to use photolithography prior to the etching of slots through the wafer. However, once the slots have been formed, the resulting topography inhibits the use of conventional photolithography.
[0107] A laser or a mechanical scribing process can also be used to create patterns. In is principle, these methods can be successfully used at any stage in the process sequence because they can cope with rugged topography.
[0108] Some patterning methods, such as photolithography, reactive ion etching, etching pastes or the use of ultrafast UV lasers, can remove dielectric layers with minimal damage to the underlying silicon. This has the advantage that removal of the dielectric layer can be accomplished without damage to the underlying silicon or the removal of diffusion layers near the surface of the silicon. Other patterning methods in addition to those described above are also possible and may be useful.
[0109] However, it is advantageous to reduce process complexity and cost, for example by reducing or eliminating the use of photolithography, where possible. In particular, photolithographic alignment of a pattern to an existing pattern requires relatively sophisticated and expensive technology. The cost of precise alignment can be significant, regardless of whether photolithography or some other patterning technique is used.
Reduced Area/Fractional Contacts
[0110] It is not necessary to make openings in the dielectric layer prior to metal deposition in order to make electrical contacts through it. In a particular arrangement, a contact metal is deposited over the dielectric layer without any openings having been formed in the dielectric coating. Subsequently, a laser beam is used to locally heat the contact metal in selected region(s) (e.g. at a plurality of mutually spaced locations) to drive the metal through the dielectric in those region(s), and thereby make electrical contact to the underlying silicon only at those region(s).
[0111] In another arrangement, the contact metal is deposited only at mutually spaced location(s) on the dielectric layer (e.g., in the form of dots or stripes), and driven through the dielectric layer by heating the whole wafer, thereby making electrical contact to the silicon underlying the region(s) of deposited metal. These dots or stripes of metal are then electrically interconnected by depositing an additional layer of metal that electrically connects the previously deposited metal regions together.
Reduced Area Diffusions
[0112] In the arrangements described above, the entire surface of each edge is relatively highly doped to enable Ohmic electrical contact to the cell to be formed, even though electrical contact is directly made only to a fractional portion of the edge surface. In otherarrangements, the edge surface is highly doped only in localised regions corresponding to the regions where the contact metal directly contacts the semiconductor. This provides several advantages.
[0113] Firstly, minority carrier recombination losses associated with the highly doped regions are reduced. Although heavy doping (usually with phosphorus or boron dopants, as appropriate, if the semiconductor is silicon) of the semiconductor surface layer to be contacted reduces zo electrical contact resistance losses and suppresses minority carrier recombination at the metal-semiconductor interface, the high concentration of dopant atoms in the doped bulk regions below the surface increases minority carrier recombination. Consequently, by reducing the volume of highly doped semiconductor, the minority carrier lifetime and hence the efficiency of the cell are correspondingly increased.
[0114] Secondly, the perimeter length over which doped p-type and doped n-type regions abut is also correspondingly reduced. Doped emitter and base regions of opposite polarity that abut are associated with increased recombination rates in the compensated region that forms at the intersection which provides reverse breakdown protection for the cell. In addition, electrical short-circuiting by carrier tunnelling is possible. These problems are exacerbated when the doping concentrations of the abutting regions are both high. Although this problem can be managed by careful adjustment of doping concentrations (for example, by driving-in dopants at high temperature to reduce peak dopant concentrations), such management can be difficult and/or inconvenient. Consequently, the reduction in the length of the perimeter between diffused regions of opposite polarity mitigates these difficulties.
[0115] Additionally, the reduction of highly doped regions reduces the probability of forming inadvertent electrical shunt paths. For example, the reduction in the area of heavily doped regions reduces the probability of inadvertent diffusion of dopant atoms through processing defects such as pinholes in a masking dielectric layer. The creation of such inadvertently doped regions (for example, within the boundaries of an oppositely doped region) can lead to electrical short circuits.
[0116] In another arrangement, localised doping and metal contact are achieved in a single processing step by incorporating dopant atoms within the contact metal and then either locally heating the metal to drive it through the dielectric, as described above, or locally depositing the metal and heating it, as described above.
[0000] Reducing or Eliminating Intersection of Diffused Regions with Slot Edges During Etching
[0117] Finally, the reduction in the volume of highly doped semiconductor at and near the edge can also be achieved by patterning the doped regions in a manner that improves the quality of the elongate substrates formed by anisotropic etching.
[0118] When many elongate substrates are formed from a single wafer by anisotropic etching, the substrate edges, which are co-planar with the wafer surface, are usually heavily doped by doping (oppositely) the entirety of both wafer surfaces prior to the anisotropic etching step. However, the resulting surface doping can interfere with the anisotropic etching by changing the etch rates at one or both wafer surfaces. For example, in the case of silicon, phosphorus and boron doping changes the etch rate in a variety of etching solutions. Heavy boron doping generally reduces etch rates in anisotropic etch solutions, whereas heavy phosphorus doping can accelerate etch rates, potentially causing undesirable lateral etching at the n-type wafer surface, leading to widening of the etch slots. Indeed, heavy diffusion of dopants of either polarity into the wafer surfaces can create defects in the silicon that lead to accelerated lateral etching. Additionally, the adhesion of masking layers that nominally resist etching by the silicon etching solution may be compromised by heavy boron and phosphorus diffusions.
[0119] Consequently, heavy diffusions, particularly those that intersect the edge of the etched slots, can complicate slot formation by etching. If very narrow slots are to be created, then this is particularly problematical.
[0120] In a particular arrangement, heavily doped surface regions of one or both polarities are formed prior to etching by dopant diffusion through a patterned mask in order to form mutually spaced doped surface regions that are also spaced from the wafer surface regions corresponding to the slots subsequently formed by etching. FIG. 10 , depicts is a schematic diagram showing perspective and plan views of an edge of an elongate semiconductor body. Selectively doped surface regions along the edge 1001 can be achieved by confining the doped region to one (e.g. plan view 1010 ) or more (e.g. two stripes in plan view 1020 ) narrow stripes down what will become the centre line of the elongate substrates. The edge 1001 is selectively doped along an elongate region centrally disposed along the longitudinal axis of the edge and spaced from the two faces of the semiconductor body that intersect the edge. This selective doping reducing the probability of the doped regions abutting or intersecting the doped surface regions of the two faces. this Because the diffused regions are narrower than the edges of the elongate substrates, then the diffused regions will not intersect with or overlap the slots formed by etching. However, this embodiment requires an aligned patterning step to ensure that the diffused regions and the slots do not overlap, intersect or abut in any way.
[0121] In other arrangements, this difficulty is overcome by patterning the dielectric for masked doping to form doped surface regions in the shape of parallel stripes that are inclined at a substantial angle to the longitudinal axes of the elongate substrates. If the stripes are relatively narrow compared with their spacing (pitch), then the length of intersection between the diffused regions and the slots is controllable and relatively small. The extent of difficulties arising during slot etching caused by the intersection of diffused regions and the slots is reduced in proportion to the reduction in length. A particular advantage of these embodiments is that the problem can be reduced without needing to align the patterned windows in the dielectric with the slots.
[0000] Delaying Heavy Phosphorus and/or Boron Diffusions Until after Slot Formation
[0122] As an alternative to the arrangements discussed above, diffusions of one or both dopant polarities into respective edges of each elongate substrate can be performed after slot etching. This reduces or eliminates the problems described above and arising from the overlap, intersection or abutment of diffused regions with the slots subsequently formed by etching.
[0123] In general, the selective doping of the elongate substrate edges after the substrates have been formed can be accomplished by selectively removing the dielectric layer only from the substrate edges (using a directional etching technique such as reactive ion etching that can be used to preferentially etch regions that are substantially parallel to the surface of the wafer) and then doping the exposed edges of the silicon (typically by furnace diffusion). If the silicon is coated with multiple layers, then a combination of methods can be used. For example, where the silicon is coated with silicon dioxide layer and a silicon nitride layer, reactive ion etching can be used to remove the overlying silicon nitride layer, and then (isotropic) wet etching used to remove the underlying silicon dioxide layer.
[0124] In some arrangements, mutually spaced regions of at least one of the edges of each substrate are selectively doped after the substrates have been formed. In some embodiments, this is accomplished by selective removal of corresponding mutually spaced regions of a masking dielectric layer using a laser, mechanical scriber, or selective application of an etch paste, followed by a dopant diffusion step.
[0125] In some arrangements, one or more selected portions of each edge are doped by forming corresponding openings in the dielectric masking layer, where the openings are in the form of elongate stripes that run along the centre line of each edge. Each edge can have a single opening, or multiple openings. In one embodiment, a directed laser is used to form each opening in the dielectric layer. However, these embodiments have the disadvantage that they require alignment of the openings with the substrate edges. Where the openings are formed after the elongate substrates have been formed, such alignment can be difficult because the substrates, particularly if they are very thin, sometimes do not remain parallel but rather become curved, thus making alignment difficult and in some cases impractical.
[0126] In one particular arrangement, the need to precisely align the openings is relaxed or avoided by forming the openings in the dielectric coating as an array of parallel stripes inclined at a substantial angle to the longitudinal axes of elongate substrates; in another the openings are in the form of a regular or random array of spots or other non-elongate shape, thus avoid the need for precise alignment of the openings with the elongate substrates. This is a major advantage if each substrate is not perfectly positioned and straight, as is often the case in practice.
[0127] In further arrangements, the introduction of dopant atoms into the substrate edges after slot etching is achieved using a liquid-jet-guided laser beam in conjunction with a jet-liquid containing the desired dopant atoms, using a liquid-guided laser system based on a Laser MicroJet™ system manufactured by Synova SA, as described at http://www.synova.ch. For example, where n-type doping of silicon is desired, phosphoric acid can be used as the laser guiding liquid. This is particularly advantageous because the doping is performed at a relatively low temperature, and in a manner that does not require masking of other areas of the cell to avoid inadvertent diffusion into unintended regions. Application of this doping technology to elongate cells, as described herein, allows discontinuous edge doping of mutually spaced doped regions to be directly and easily formed.
[0128] In one particular arrangement, a liquid-jet-guided laser beam is used to locally form one or more openings in a dielectric coating and optionally also to simultaneously dope one or more corresponding regions of the semiconductor body. For example, a liquid-jet-guided laser forms a shallow (e.g., about 10-15 μm) trench in the semiconductor while at the same time disrupting an overlying dielectric coating (typically a silicon nitride layer). If the liquid jet contains a dopant species, then the walls of the trench are simultaneously doped in the same process step. One or more electrical contacts to the semiconductor body can then be formed by depositing an electrically conductive material, either locally at each opening, or more broadly to cover not only the openings, but also the remaining dielectric coating. In either case, the electrically conductive material only contacts those regions of the semiconductor body that are exposed by the openings formed by the liquid-jet-guided laser beam.
[0129] In an alternative arrangement, one or more localised regions of the semiconductor body are selectively doped by laser doping, but without requiring a liquid-jet-guided laser beam. In this embodiment, a layer of doping material containing a dopant species (e.g., phosphorus oxide glass) is deposited over the semiconductor body, and is subsequently locally heated with a laser beam to drive the dopant species into corresponding regions of the semiconductor body. The layer of material containing the dopant species can contact the semiconductor body directly, or alternatively can be separated from the semiconductor body by a layer of dielectric material. In the latter case, the laser beam is strongly absorbed in the underlying semiconductor and the resulting heating disrupts the dielectric coating to allow the dopant species to be driven into the exposed surface(s) of the semiconductor body. As with the arrangements described above, one or more electrical contacts to the semiconductor body are then formed by depositing an electrically conductive material, either locally, or more broadly. In either case, the electrically conductive material only contacts those regions of the semiconductor body that are exposed by the openings formed by the laser beam.
Thermal Treatments
[0130] Although the processes described above reduce the impact of processing defects on the performance of elongate solar cells, particularly those formed by anisotropic etching, thermal treatments can be used in conjunction with those processes to further improve solar cell performance.
[0131] It is well known that intersecting regions that are heavily doped with opposite polarity doping can have electrical short circuits appearing between the two regions due to electron tunneling. Devices such as the tunnel diode take advantage of this phenomenon. In a solar cell, such a short circuit will generally reduce performance, and is usually best avoided. Adjacent heavy diffusions of opposite polarity into the silicon surface can give rise to such difficulties if they intersect, for example at the boundary between an edge and a face in an elongate solar cell. Thermal treatments can be used to lower the concentration of dopants in one or both of the doped regions where they are highest, which is generally at or near the surface. However, such thermal treatments are problematical in this example, because two problems should be simultaneously addressed: the need to avoid short circuits between intersecting heavily doped regions, and the need to ensure that one doping type predominates across the entire surface of the edge. Careful adjustment of both the doping dose/fluence and the subsequent thermal history can avoid both of these problems. For example, in the case of an elongate cell with phosphorus diffused faces and one boron diffused edge, where the sheet resistance of the two diffusions after drive in is in the vicinity of 100 Ohms per square and 40 Ohms per square, respectively, a drive-in heating step at 1100 degrees C. for 60 minutes eliminates short circuits whilst preserving boron as the dominant impurity across the whole of the edge of the cell.
[0132] The left-hand side of FIG. 9 is a schematic view of a face 901 and edge 903 of an elongate solar cell at one stage during its production, showing how the n-type (or alternatively, p-type) face doping 902 extends to the surface of the p-type (or alternatively, n-type) edge 901 at one region 904 , causing a short circuit to appear between n and p type regions 902 and 908 after formation of the metallisation contact layer 906 . The right-hand side of FIG. 9 shows the effect of the thermal treatment described above, which causes the heavier boron p-type doping 908 on the edge 901 to diffuse into the short-circuit region 904 , thereby dominating across the entire surface of the edge 901 and, counter-doping the initially n-type region 902 near the edge 901 so that the entire surface of the edge 901 becomes p-type, thereby avoiding a short circuit.
[0133] For conventional elongate solar cell designs, processing defects will have a less severe effect if they are at an edge of the opposite doping polarity to the background doping of the semiconductor body of the cell. The reason for this is that the faces are also doped oppositely to the substrate of the cell, and so shorting the face to the edge does not cause a short circuit in the solar cell because the face and edge have the same doping polarity.
EXAMPLES
Example 1
[0134] In a first example a plurality of elongate solar cells held in a frame of a semiconductor wafer, each cell having fractional edge contacts, was formed using the following process.
[0135] An n-type dopant (e.g. phosphorus or arsenic) was initially diffused into one surface (e.g. the top surface, corresponding to one edge of the cell after formation of the elongate cells) of a p-type (110) oriented 1 mm thick silicon wafer to achieve sheet resistance (R s ) in the range is of about 20 to about 350Ω/□ (Ohms-per-square) and a p-type dopant (e.g. boron or gallium) diffused into the reverse surface to achieve sheet resistance, R s , in the range of between about 20 to about 80Ω/□ (i.e. heavily doped), taking steps to avoid cross-doping. After further processing (to form slots in the wafer and form the elongate substrates of FIG. 2 ), these surfaces will become the edges of the elongate solar cells. Alternative wafer thicknesses may also be used, where the thickness of the wafer may be selected between about 0.2 mm and about 5 mm. As would be appreciated by the skilled addressee, the dopant types may be reversed mutandis mutandi by replacing “n-type” with “p-type” and vice versa.
[0136] A protective dielectric coating was applied to the top and bottom surfaces of the wafer, and elongate windows in this coating were opened using lithography (e.g. photolithography) and reactive ion etching operations. A plurality of deep and narrow trenches were etched through the entire wafer in the region of the elongate windows to form the plurality of elongate substrates held within a frame as depicted in FIG. 2 . The sidewalls of these trenches become the faces of the elongate solar cells. Alternatively, the trenches may be formed nearly through the wafer, for example greater than 95% of the wafer thickness or to within about 50 μm or less of the rear surface of the wafer. The small portion of remaining wafer at the bottom of the trench may assist in maintaining the separation of the elongate substrates during subsequent processing steps.
[0137] The wafer was next diffused with a n-type dopant (e.g. phosphorous or arsenic) using a gas phase deposition process. A suitable dopant source for phosphorous diffusion is POCl 3 . All dielectric layers were removed in an acid solution (e.g. HF) and then the wafer was oxidised in an oxygen atmosphere at 1000° C. to form silicon dioxide.
[0138] A regularly spaced array of elongate contact openings if formed in the silicon dioxide coatings on both edges of the elongate cells (i.e. in the plane of the top and bottom surfaces of the wafer). The elongate contact openings are formed orthogonal to the longitudinal axis of each elongate substrate (cell), with a selected pitch (for example, about 0.5 to about 10 mm), such that the openings expose a fraction of the surface area of the top and bottom edges of the elongate substrates. The fraction of the surface area of each substrate that is exposed may be selected between about 0.01% and about 99% of the total surface area of the edges, e.g. about 1%, 10%, 25%, 50%, 75%, 90% 95%, 98% or about 99%. A perspective and plan view of the orthogonal is openings in the dielectric material to expose the fractional portion of the edges is depicted in FIG. 8 .
[0139] A metal is then evaporated onto each edge to form a fractional contact to the elongate solar cell. This metal will make intermittent contact to the openings in the dielectric layer on the slot edges. Examples of metals that may be used in this and in the subsequent examples for evaporation onto each edge include Co, Ni, Pd, Pt, Ti, Ag, Al and others. The metal structure may also contain a combination of those. The probability of a defect being present within these openings (which could cause a short circuit between n and p regions) is reduced by about a factor proportionate to the surface area of the edge contacted by the metal. The metal may be evaporated at an inclined angle 710 with respect to the faces, for example about 45° as depicted in FIG. 7 .
[0140] The plurality of elongate solar cells held in the frame of the semiconductor wafer may then be separated from the wafer frame in further processing to form a plurality of individual separated elongate solar cells, each elongate solar cell having fractional edge contacts.
Example 2
[0141] In a second example, a plurality of elongate solar cells held in a frame of a semiconductor wafer, each cell having fractional edge contacts, was formed using the following process.
[0142] An n-type dopant (e.g. phosphorus or arsenic) is diffused into one surface (e.g. the top surface, corresponding to one edge of the cell after formation of the elongate cells) of a p-type (110) oriented 1 mm thick silicon wafer to achieve a sheet resistance of about R s ≈20 to about 350Ω/□. Alternative wafer thicknesses may also be used, where the thickness of the wafer may be selected between about 0.2 mm and about 5 mm. As would be appreciated by the skilled addressee, the dopant types may be reversed mutandis mutandi by replacing “n-type” with “p-type” and vice versa.
[0143] A protective dielectric coating is deposited onto the surfaces of the wafer and elongate windows opened in this coating using lithography (e.g. photolithography) and reactive ion etching operations. A plurality of deep and narrow trenches were etched through the entire wafer in the regions of the elongate windows to form a plurality of elongate substrates held within a frame as depicted in FIG. 2 . The sidewalls of these trenches become the faces of the elongate solar cells. Alternatively, the trenches may be formed nearly through the wafer, for example greater than 95% of the wafer thickness or to within about 50 μm or less of the rear surface of the wafer. The small portion of remaining wafer at the bottom of the trench may assist in maintaining the separation of the elongate substrates during subsequent processing steps.
[0144] An n-type dopant (e.g. phosphorus or arsenic) is diffused into both sidewalls of the trenches to achieve sheet resistance R s in the range of between about 40Ω/□ and about 200Ω/□, therefore providing doping on the faces of the elongate substrates. A passivating oxide is grown on the faces and the n-type dopant is driven in at a high temperature in order to adjust the doping profiles of the diffused regions on the top surface of the wafer and on the faces of the elongate substrates. Next, a diffusion barrier material, such as silicon nitride, is formed on the faces of the elongate substrates.
[0145] Next, a regularly spaced array of openings in the dielectric coatings on the undoped edge of the elongate solar cells (the edge in the plane of the wafer that was undoped i.e. the bottom wafer surface), orthogonal to the longitudinal axis of each elongate solar cell (similar to that depicted in FIG. 8 ), with a selected pitch (for example, about 0.5 to about 10 mm) such that the openings expose a fraction of the surface area of the top and bottom edges of the elongate substrates. The fraction of the surface area of each substrate that is exposed may be selected between about 0.01% and about 99% of the total surface area of the edges, e.g. about 1%, 10%, 25%, 50%, 75%, 90% 95%, 98% or about 99%.
[0146] A p-type dopant (e.g. boron or gallium) is next diffused into this array of openings using a gas phase diffusion process. A suitable dopant source for boron doping is BBr 3 . The boron silicate glass formed during the diffusion process is removed afterwards in an acid solution (e.g. HF).
[0147] Next, a regularly spaced array of openings is created in the dielectric coatings on the n-type (phosphorus) doped edge (in the plane of the top surface of the wafer) of the elongate solar cells, orthogonal to the longitudinal axis of each elongate solar cell, with a selected pitch (for example, about 0.5 to about 10 mm), such that the openings expose a fraction of the surface area of the top and bottom edges of the elongate substrates. The fraction of the surface area of each substrate that is exposed may be selected between about 0.01% and about 99% of the total surface area of the edges, e.g. about 1%, 10%, 25%, 50%, 75%, 90% 95%, 98% or about 99%.
[0148] A metal is then evaporated onto each edge to form a fractional contact to the elongate solar cell. This metal will make intermittent contact to the openings in the dielectric layer on the slot edges. The metal may be evaporated at an angle 710 with respect to the faces, for example 45° as depicted in FIG. 7 .
[0149] The plurality of elongate solar cells held in the frame of the semiconductor wafer may then be separated from the wafer frame in further processing to form a plurality of individual separated elongate solar cells, each elongate solar cell having fractional edge contacts.
Example 3
[0150] In a third example, a plurality of elongate solar cells held in a frame of a semiconductor wafer, each cell having fractional edge contacts, was formed using the following process.
[0151] A p-type dopant (e.g. boron or gallium) is diffused into one surface (e.g. the top surface) of a p-type (110) oriented 1 mm thick silicon wafer to achieve sheet resistance, R s , in the range of about 20 to about 80Ω/□ (i.e. heavily doped). Alternative wafer thicknesses may also be used, where the thickness of the wafer may be selected between about 0.2 mm and about 5 mm. As would be appreciated by the skilled addressee, the dopant types may be reversed mutandis mutandi by replacing “n-type” with “p-type” and vice versa.
[0152] A protective dielectric coating is deposited onto the surfaces of the wafer and elongate windows opened in this coating using lithography and reactive ion etching operations, and a plurality of deep and narrow trenches etched through the entire wafer in the regions of the elongate windows to form a plurality of elongate substrates held within a frame as depicted in FIG. 2 . The sidewalls of these trenches become the faces of the elongate solar cells. Alternatively, the trenches may be formed nearly through the wafer, for example greater than 95% of the wafer thickness or to within about 50 μm or less of the rear surface of the wafer. The small portion of remaining wafer at the bottom of the trench may assist in maintaining the separation of the elongate substrates during subsequent processing steps.
[0153] A n-type dopant (e.g. phosphorous or arsenic) is diffused into both sidewalls of the trenches to achieve sheet resistance R s in the range of between about 40Ω/□ and about 200Ω/□, therefore providing doping on the faces of the elongate substrates. A passivating oxide is grown on the faces and the n-type dopant (phosphorus) is driven in at a high temperature in order to adjust the doping profiles of the diffused regions on the top surface of the wafer and on the faces of the elongate substrates.
[0154] Next, a surface electrical passivation material, such as silicon dioxide, is formed on the faces of the elongate substrates.
[0155] Using a liquid jet guided laser in combination with phosphoric acid, a regularly spaced array of openings is formed in the dielectric coatings and the surface region of the silicon on the hitherto undoped edge (i.e. in the plane of the bottom surface of the wafer) of the elongate solar cells, orthogonal to the long axis of each elongate solar cell (similar to that depicted in FIG. 8 ), with a selected pitch (for example, about 0.5 to about 10 mm), such that the openings expose a fraction of the surface area of the top and bottom edges of the elongate substrates. The fraction of the surface area of each substrate that is exposed may be selected between about 0.01% and about 99% of the total surface area of the edges, e.g. about 1%, 10%, 25%, 50%, 75%, 90% 95%, 98% or about 99%. The diffusion glass is then removed from the openings.
[0156] Next, a regularly spaced array of openings is created in the dielectric coatings on the p-type (boron) doped edge (in the plane of the top surface of the wafer) of the elongate solar cells, orthogonal to the longitudinal axis of each elongate solar cell, with a pitch of selected pitch (for example, about 0.5 to 10 mm), such that the openings expose a fraction of the surface area of the top and bottom edges of the elongate substrates. The fraction of the surface area of each substrate that is exposed may be selected between about 0.01% and about 99% of the total surface area of the edges, e.g. about 1%, 10%, 25%, 50%, 75%, 90% 95%, 98% or about 99%.
[0157] A metal is then evaporated onto each edge to form a fractional contact to the elongate solar cell. This metal will make intermittent contact to the openings in the dielectric layer on the slot edges. The metal may be evaporated at an angle 710 with respect to the faces, for example 45° as depicted in FIG. 7 .
[0158] The plurality of elongate solar cells held in the frame of the semiconductor wafer may then be separated from the wafer frame in further processing to form a plurality of individual separated elongate solar cells, each elongate solar cell having fractional edge contacts.
Example 4
[0159] In a fourth example, a plurality of elongate solar cells held in a frame of a semiconductor wafer, each cell having fractional edge contacts, was formed using the following process.
[0160] A p-type dopant is diffused into one surface (e.g. the top surface) of an n-type (110) oriented 1 mm thick silicon wafer. Alternative wafer thicknesses may also be used, where the thickness of the wafer may be selected between about 0.2 mm and about 5 mm. As would be appreciated by the skilled addressee, the dopant types may be reversed mutandis mutandi by replacing “n-type” with “p-type” and vice versa.
[0161] A protective dielectric coating is deposited onto the surfaces of the wafer and elongate windows opened in this coating using lithography and reactive ion etching operations, and a plurality of deep and narrow trenches etched through the entire wafer in the regions of the elongate windows to form a plurality of elongate substrates held within a frame as depicted in FIG. 2 . The sidewalls of these trenches become the faces of the elongate solar cells. Alternatively, the trenches may be formed nearly through the wafer, for example greater than 95% of the wafer thickness or to within about 50 μm or less of the rear surface of the wafer. The small portion of remaining wafer at the bottom of the trench may assist in maintaining the separation of the elongate substrates during subsequent processing steps.
[0162] A p-type dopant is diffused into both sidewalls of the trenches to achieve sheet resistance R s in the range of between about 40Ω/□ and about 200Ω/□, therefore providing doping on the faces of the elongate substrates. A passivating oxide is grown on the faces and the p-type dopant is driven in at a high temperature in order to adjust the doping profiles of the diffused regions on the top surface of the wafer and on the faces of the elongate substrates.
[0163] Next, a surface electrical passivation material, such as silicon dioxide, is formed on the faces of the elongate substrates.
[0164] Using a liquid jet guided laser in combination with phosphoric acid, one or more openings are formed in the dielectric coating on the edge of the elongate substrates in the plane of the wafer surfaces, perpendicular to the long axis of each elongate substrate (similar to that depicted in FIG. 8 ), such that the openings expose a fraction of the surface area of the top and bottom edges of the elongate substrates. The fraction of the surface area of each substrate that is exposed may be selected between about 0.01% and about 99% of the total surface area of the edges, e.g. about 1%, 10%, 25%, 50%, 75%, 90% 95%, 98% or about 99%. The diffusion glass is then removed from the openings.
[0165] A metal is then evaporated onto each edge to form a fractional contact to the elongate solar cell. The metal may be evaporated at an angle 710 with respect to the faces, for example 45° as depicted in FIG. 7 .
[0166] The plurality of elongate solar cells held in the frame of the semiconductor wafer may then be separated from the wafer frame in further processing to form a plurality of individual separated elongate solar cells, each elongate solar cell having fractional edge contacts.
Example 5
[0167] In a fifth example a plurality of elongate solar cells held in a frame of a semiconductor wafer, each cell having fractional edge contacts, was formed using the following process as depicted in FIGS. 14A to 14F .
[0168] An n-type dopant (e.g. phosphorus) was initially diffused into one surface of a p-type (110) oriented 1 mm thick silicon wafer to achieve sheet resistance (R s ) in the range of between about 20 to about 350Ω/□ (Ohms-per-square) and a p-type dopant (e.g. boron) diffused into the reverse surface with R s in the range of about 20Ω/□ to about 80Ω/□ (i.e. heavily doped), taking steps to avoid cross-doping. Alternative wafer thicknesses may also be used, where the thickness of the wafer may be selected between about 0.2 mm and about 5 mm. As would be appreciated by the skilled addressee, the dopant types may be reversed mutandis mutandi by replacing “n-type” with “p-type” and vice versa.
[0169] A protective dielectric coating is deposited onto the surfaces of the wafer consisted of silicon dioxide ( 1403 ) and silicon nitride ( 1405 ) as depicted in FIG. 14 and elongate windows opened in this coating using photolithography and reactive ion etching operations. A plurality of deep and narrow trenches are then etched through the entire wafer in the regions of the elongate windows to form a plurality of elongate substrates held within a frame as depicted in FIG. 2 . The sidewalls of these trenches become the faces of the elongate solar cells. Alternatively, the trenches may be formed nearly through the wafer, for example greater than 95% of the wafer thickness or to within about 50 μm or less of the rear surface of the wafer. The small portion of remaining wafer at the bottom of the trench may assist in maintaining the separation of the elongate substrates during subsequent processing steps.
[0170] An n-type (or n-type) dopant is diffused into both sidewalls of the trenches to achieve sheet resistance R s in the range of between about 40Ω/□ and about 200Ω/□, therefore providing doping on the faces of the elongate substrates. A passivating silicon nitride is deposited on the faces and the n-type (or p-type) dopant is driven in at a high temperature in order to adjust the doping profiles of the diffused regions on both sides of the wafer and on the faces of the elongate substrates.
[0171] Next, as depicted in FIG. 14B , the silicon oxide and silicon nitride layers are then etched with an etchant that etches the silicon oxide faster than the silicon nitride to form a recess 1407 .
[0172] A local-oxidation of silicon (LOCOS) oxidation is performed, wherein oxide grows where the silicon nitride is not on silicon, to form the structure as depicted in FIG. 14C with silicon oxide protrusions 1409 .
[0173] Next, the silicon nitride and silicon oxide are etched sequentially to expose the doped edge 1401 of the elongate substrate 1400 , thereby exposing a fractional portion of the surface area of the edge as depicted in FIG. 14D . The fraction of the surface area of each substrate that is exposed may be selected between about 0.01% and about 99% of the total surface area of the edges, e.g. about 1%, 10%, 25%, 50%, 75%, 90% 95%, 98% or about 99%.
[0174] A metal layer is then evaporated onto the edge 1401 to form a fractional contact 1411 to the elongate solar cell 1400 , as depicted in FIG. 14E . The metal may be evaporated at an angle 710 with respect to the faces, for example 45° as depicted in FIG. 7 . Depending on the method of depositing the metal layer, the metal may also form on a small portion of the faces of the elongate cells, for example as depicted in FIG. 14F .
[0175] The plurality of elongate solar cells held in the frame of the semiconductor wafer may then be separated from the wafer frame in further processing to form a plurality of individual separated elongate solar cells, each elongate solar cell having fractional edge contacts.
[0176] In other arrangements of this example, a stack of silicon oxide, silicon nitride, silicon oxide, and silicon nitride is deposited onto the edge. In this arrangement, the stack is firstly etched with an etchant that attacks oxide much faster than nitride (e.g. buffered oxide etch), then next etched with a chemical that attacks nitride faster than oxide (e.g. phosphoric acid). This provides a cleaner structure without the overhang shown in the FIG. 14B . The LOCOS oxidation can then be undertaken and the process continued as above.
[0177] The process of this example are particularly suited to larger contact fractions, greater than say about 50%, as this requires the formation of smaller recesses.
[0178] Although embodiments of the present invention have been described above in terms of doping silicon using thermal diffusion, it will be apparent to those skilled in the art that the invention can be applied to other semiconductors, and that doping can be achieved by any of a variety of different methods, including ion implantation, for example.
[0179] Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention as hereinbefore described with reference to the accompanying drawings.
[0180] It will be appreciated that the methods and solar cell devices described/illustrated above at least substantially provide an improved solar cell comprising a fractional edge contact.
[0181] The processes, methods and solar cell devices described herein, and/or shown in the drawings, are presented by way of example only and are not limiting as to the scope of the invention. Unless otherwise specifically stated, individual aspects and components of the processes, methods and solar cell devices may be modified, or may have been substituted therefore known equivalents, or as yet unknown substitutes such as may be developed in the future or such as may be found to be acceptable substitutes in the future. The processes, methods and solar cell devices may also be modified for a variety of applications while remaining within the scope and spirit of the claimed invention, since the range of potential applications is great, and since it is intended that the present processes, methods and solar cell devices be adaptable to many such variations.
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An elongate solar cell, comprising a semiconductor body having two mutually opposed faces, at least one of the faces being an active face for receiving incident light, and two mutually opposed edges orthogonal to the faces, the edges comprising electrical contacts thereon for conducting electrical current generated by the solar cell from the light; wherein the electrical contact to at least one of the edges includes an electrically conductive material that contacts only a fractional portion of the at least one edge of the semiconductor body to improve the performance of the solar cell.
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The present invention relates to a process for the preparation of highly crystalline high melting 1,5-hexadiene cyclopolymers and products thus obtained.
It is known how to prepare 1,5-hexadiene cyclopolymers with Ziegler-Natta catalyst, as reported in the J. Am. Chem. Soc. 1958, 80, 1740, where the catalyst used is the TiCl 4 /Al(C 4 H 9 ) 3 mixture in various proportions.
However, the data reported in the above mentioned article show that for the 1,5-hexadiene cyclopolymer thus obtained, the cyclopolymerization is not complete (from 5 to 8% on the monomeric units contained in the chain maintain a double bond), and the melting points are low (85°-90° C). Moreover, long polymerization times are needed (from 50 to 70 hours) in order to obtain high monomer conversion.
In the J. Polym. Sci. part A 1964, 2, 1549, the polymerization of 1,5-hexadiene with TiCl 4 /Al(C 2 H 5 ) 3 , TiCl 3 . 0.22 AlCl 3 /Al(C 2 H 5 ) 3 and TiCl 2 . 0.5 AlCl 3 /Al(C 2 H 5 ) 3 catalyst systems is discussed. The polymers thus obtained have melting points from 119° to 146° C.
An in-depth structural study of this type of cyclopolymers (obtained by polymerizing the 1,5-hexadiene with a TiCl 3 /Al(C 2 H 5 ) 2 Cl catalyst system) is reported in the J. Appl. Polymer. Sci. 1988, 35, 825, where NMR analysis demonstrates that the units which occur in the polymer chain are mainly groups having the ##STR1## structure, where the cyclopentane rings can be either in cis- or trans- configuration. The data reported in said article proved that the polymers obtained with the above mentioned catalyst system contain cyclopentane rings in cis- and trans-configuration in a ratio of about 1/1.
The J. Am. Chem. Soc. 1990, 112, 4953, describes how by using a mixture of a zirconocene and a methylalumoxane in the cyclopolymerization of the 1,5-hexadiene one can control the configuration of the polymer cyclopentane rings. In particular, by using the Cp 2 ZrCl 2 (Cp=cyclopentadienyl), a cyclopolymer predominantly of trans-configuration is obtained, while by using Cp* 2 ZrCl 2 (Cp*=pentamethylcyclopentadienyl) a cyclopolymer predominantly of cis- configuration is obtained. However, according to the above mentioned article, particularly in the case where it is desired to obtain cyclopolymers predominantly of the cis-configuration, the procedure must be carried out at very low temperatures. The best result (86% of rings with the cis-configuration) is obtained by carrying out the polymerization at -25° C.
Now the Applicant has found that the crystallinity in the 1,5-hexadiene cyclopolymer is particularly high in relation to the high content of rings in the cis- configuration of the polymer chain, as demonstrated see by comparing the attached FIGS. 1 and 2.
BRIEF DESCRIPTION OF THE DRAWINGS
In fact, FIG. 1 shows the X-ray diffraction spectrum (CuKα) of a poly (1,5-hexadiene) sample containing 87.9% of cyclopentane rings in cis- configuration (obtained according to Example 1 below). In this Figure a single nondiffused peak typical of a crystalline phase can be seen. In FIG. 2, on the other hand, an X-ray diffraction spectrum of a poly (1,5-hexadiene) sample containing about 40% of cyclopentane rings in cis- configuration is shown, whereby a peak which is diffused and has little intensity, typical of a prevalently amorphous phase, can be seen.
The melting point is also particularly high in relation to the high contents of rings in cis- configuration, as demonstrated by the examples of the present invention.
Therefore, it would be very beneficial to have a process of polymerization which would allow one to obtain, economically (particularly without having to operate at extremely low temperature), highly crystalline high melting cyclopolymers of the 1,5-hexadiene, since this type of cyclopolymers offer high heat stability and good processability.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly, the present invention provides a process for the preparation of 1,5-hexadiene cyclopolymers which comprises the polymerization of monomers in the presence of a catalyst consisting essentially of:
A) a metallocene compound having either the formula
(C.sub.5 R.sub.5).sub.2 MX.sup.1 X.sup.2 (I)
where M is Zr or Hf, preferably Zr; the R radicals are the same or different and are hydrocarbon radicals, in particular C 1 -C 7 alkyls; X 1 and X 2 are the same or different and are H, halogens, C 1 -C 20 hydrocarbon radicals, in particular C 1 -C 20 alkyl, or C 7 -C 20 arylalkyl or alkaryl radicals, or --OR --OH, --SR or SH radicals, where R has the meaning defined above; or the formula
Q(C.sub.5 R.sub.4).sub.2 MX.sup.1 X.sup.2 (I')
where M, R, X 1 and X 2 have the same meaning defined for the compound (I); Q is a bivalent radical C 2 R' 4 or Si 2 R 4 , where the R' radicals are the same or different and are hydrogen or are the same as R;
B) one or more alumoxane compounds of the formula: ##STR2## where R' is a C 2 -C 20 alkyl or alkene radical, or C 7 -C 20 alkaryl radical; n is a number from 1 to 20. Particularly preferred are the compounds of the formula (I) where the R radicals are methyl and/or ethyl, and the compounds of formula (II) where the R' radicals are isobutyl.
Examples representative of metallocene compounds of formula (I) are:
(C 5 Me 5 ) 2 ZrCl 2 ; (C 5 Me 5 ) 2 ZrMe 2 ; (C 5 Me 5 ) 2 ZrClMe; (C 5 Me 5 ) 2 ZrCliBu; (C 5 Me 5 ) 2 ZrCl(CH 2 C 6 H 5 ); (C 5 Me 5 ) 2 ZrClCH 2 SiMe 3 ; (C 5 Me 4 Et) 2 ZrCl 2 ; (C 5 Me 5 ) 2 HfCl 2 ; (C 5 Me 5 ) 2 HfMe 2 ; (C 5 Me 5 ) 2 HfCliBu; and (C 5 Me 5 ) 2 HfCl(CH 2 C 6 H 5 ); where Me=methyl, Et=ethyl, Bu=butyl.
Examples representative of alumoxane compounds of formula (II) are:
Et 2 AlOAlEt 2 ; iBu 2 AlOAliBu 2 ; iEs 2 AlOAliEs 2 ; and iBu 2 AlOAl(iBu)OAliBu 2 ; where Es=hexyl.
These alumoxane compounds can be used alone or in a solution in hydrocarbon, such as hexane, heptane, benzene and toluene.
Moreover, the alumoxane compounds can contain variable quantities of trialkyl aluminum, such as AlEt 3 or AliBu 3 . Said aluminum trialkyl can be the same used to prepare the alumoxane compound. The quantity of said aluminum trialkyl affects the activity of the catalyst and is preferably less than 50% in moles, more preferably less than 20%, according to what can be determined from the NMR analysis, with respect to the total Al content.
The polymerization can be carried out either in monomer alone, or mixed with a hydrocarbon such as hexane, heptane, and toluene.
The molar ratio between the (A) and (B) catalyst components is preferably from 20 to 5000, more preferably from 500 to 2000.
The (A) and (B) components can be added directly to the monomer, or monomers, to be polymerized, or can be previously mixed in a hydrocarbon solution.
The polymerization temperature is preferably from -20° to 20° C.
The examples will show that an additional advantage of the process of the present invention is the fact that, compared to processes known in the art which use methylalumoxane as component (B), the instant process allows one to obtain 1,5-hexadiene cyclopolymers with higher molecular weight.
Moreover, according to the process of the present invention, the polymerization of 1,5-hexadiene can be carried out in the presence of other monomers such as ethylene, or higher α-olefins, in particular C 3 -C 8 , thus obtaining copolymers whose properties depend on the quantity and type of comonomers used.
Therefore, the definition of 1,5-hexadiene cyclopolymers according to the present invention comprises both the 1,5-hexadiene homopolymers, which are the preferred ones, and 1,5-hexadiene copolymers with one or more α-olefin, including ethylene.
The preferred 1,5-hexadiene cyclopolymers obtained with the process of the present invention have a percentage of cyclopentane rings in the cis-configuration greater than 87, for example from 87 to 95; crystallinity greater than or equal to 50%, measured with X-ray diffractometry; and a melting point greater than or equal to 175° C., generally from 175° to 185° C. Moreover, the intrinsic viscosity of the above mentioned polymers, measured in tetrahydronaphthalene at 135° C., is preferably greater than or equal to 0.5.
The following examples are given in order to illustrate and not limit the present invention.
In the examples, the percentage of cyclopentane rings in the cis-configuration has been measured by way of 13 C NMR.
The 13 C NMR spectra have been determined by way of a Bruker 200 MHz instrument, using C 2 D 2 Cl 4 as solvent, at 100° C. The melting points were measured with a Perkin Elmer DSC7 instrument with a 10° C./min scanning rate. The values relate to the highest point in the peak during the second melt.
The intrinsic viscosity was measured in tetrahydronaphthalene at 135° C.
Synthesis of the tetraisobutyl dialumoxane (TIBAO) (Method 1)
Into a 250 ml flask with three necks, equipped with magnetic agitator, in nitrogen atmosphere, are introduced 120 ml of anhydrous toluene and 16.64 g of AliBu 3 recently distilled, and the solution is cooled to 0° C. In a glass container connected to the reaction flask are introduced 0.755 ml of distilled water. By way of a diaphragm compressor, the system gases are circulated between the flask and the water container until all the water is used up, and then for an additional 10 minutes after that. The clear and colorless solution is concentrated to 100 ml by flashing the solvent at reduced pressure. The 1 H NMR analysis shows that the AliBu 3 content not reacted is at <5%.
Preparation of the tetraisobutyl dialumoxane from the commercial product Schering (Method 2)
From 250 ml of heptane solution at 20% in declared weight of tetraisobutyl dialumoxane (Schering commercial product) the solvent is removed by evaporation at 0.2 torr pressure and 50° C.
The oily product thus obtained is dissolved in 30 ml of toluene, heated to 50° C. under vacuum, and then the solvent is flashed.
This treatment is repeated 4 times. The 1 H NMR analysis shows the presence of 8% of AliBu 3 (percentage of iBu moles of AliBu 3 based on the total iBu moles), while the quantity of said moles in the starting product was 30%.
EXAMPLES 1-3 AND COMPARATIVE EXAMPLE 1
The 1,5-hexadiene has been distilled in the rectifying column, and dehydrated with CaH 2 . The purity of the monomer thus treated was higher than 99%.
POLYMERIZATION
The desired quantity of 1,5-hexadiene is introduced into an armed glass cylinder in nitrogen atmosphere. In another armed cylinder is introduced the aluminum compound solution in the desired solvent, then the proper quantity of Cp* 2 ZrCl 2 dissolved in toluene is added. The ingredients are reacted at room temperature for 5 minutes, and then the resultant solution thus obtained is added to the monomer to be polymerized, which has been thermoregulated at the polymerization temperature.
The polymerization is interrupted by adding methanol, then HCl is added in order to dissolve the catalyst residues, and the content is filtered and then washed with methanol. The polymerization conditions, and the properties of the products obtained are shown in Table 1.
By comparing the intrinsic viscosity of Example 2 and comparative Example 1, it can be seen that with the process of the present invention cyclopolymers having a high intrinsic viscosity and therefore higher molecular weight are obtained.
EXAMPLE 4: 1,5-HEXADIENE/ETHYLENE COPOLYMERIZATION
Into a 250 ml glass autoclave in an ethylene atmosphere and containing 13.8 g of 1,5-hexadiene and 30 ml of toluene, is introduced a solution, maintained for 5 minutes in the absence of monomer, of 20 ml of toluene, 1.96 mg of Cp* 2 ZrMe 2 , and 0.743 g of TIBAO prepared according to Method 2. The ethylene pressure is brought to 2 atm, and it is stirred for 15 minutes at constant pressure and 20° C. 4.15 g of solid polymer are obtained. The DSC shows only one melt peak, with T m =121° C.
Other features, advantages and embodiments of the invention disclosed herein will be readily apparent to those exercising ordinary skill after reading the foregoing disclosure.
In this regard, while specific embodiments of the invention have been described in considerable detail, variations and modifications of these embodiments can be effected without departing from the spirit and scope of the invention as described and claimed.
TABLE 1__________________________________________________________________________ AlEx. (μ Al/Zr Hexadiene PT Pt Toluene Tm I.V.n. Alumoxane moles) (molar) (g) (°C.) (h) ml Yield* °C. % Cis dl/g__________________________________________________________________________1 TIBAO.sup.1 28.7 840 36.7 20 26 28 3070 179.5 87.9 --2 TIBAO.sup.2 15 1000 41.5 20 4 60 10300 176.3 89.6 0.573 TIBAO.sup.2 15 1000 13.8 0 4 4 2190 183.8 91.5 --comp MAO 3 1000 13.8 20 1 5 16400 172.3 -- 0.44__________________________________________________________________________ *(g polymer/g Zr) .sup.1 Prepared according to method 1 .sup.2 Prepared according to method 2 MAO: methyl alumoxane Shering dried under vacuum PT: Polymerization temperature Pt: Polymerization time Tm: Melting temperature I.V.: Intrinsic viscosity
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Highly crystalline high melting 1,5-hexadiene cyclopolymers are prepared by carrying out the polymerization in the presence of a catalyst comprising a specific Zr or Hf metallocene compound and specific alumoxane compounds.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional of co-pending patent application Ser. No. 10/599,477 filed Sep. 29, 2006, now U.S. Pat. No. 7,744,674 which is a national stage application filed under 35 USC 371 based on International Application No. PCT/SE2005/000497 filed Apr. 6, 2005, and claims priority under 35 USC 119 of Swedish Patent Application No. 0400937.9 filed Apr. 7, 2004.
TECHNICAL FIELD
The present invention relates to a method of producing a product that can be used as a fluxing agent in steel production. The invention also relates to a method in connection with steel production, preferably of a stainless steel, comprising production of a steel heat, decarburization of the steel heat whereby a slag is applied on top of said steel heat. Finally, the invention also relates to a product produced according to the invention.
PRIOR ART
The production of steel, especially stainless steel, comprises annealing and pickling processes. The annealing is a heat treatment operation that aims at recrystallizing the microstructure of the steel and making it ductile. In the annealing, an oxide layer is formed on the surface of the steel, and a chromium-depleted layer is formed directly beneath the oxide layer. Both of these two layers are removed by pickling.
Pickling means that the annealed steel product is treated by acid, most often a mixture of different acids, by which the undesired metal deposits in the surface are taken away. A mixture of nitric acid, HNO 3 , and hydrofluoric acid, HF, is the most efficient for pickling of stainless steel. The dissolved metals form metal complexes and deposits that have to be removed from the process. Especially, it is difficult to handle spent pickling liquids that contain mixed acids, such as a mixture of nitric acid (HNO 3 ) and hydrofluoric acid (HF), containing fluorides. Also the content of e.g. iron, chromium and nickel oxides in the production of stainless steels, constitutes a handling problem.
After the pickling treatment, the steel product is flushed by water, whereby acidic flushing water is formed. The dissolved metals in the form of metal complexes and deposits, as well as the acidic flushing water, constitute waste matters of severe environmental impact, and must be subjected to special handling in order not to cause severe environmental damages. Similarly to the case in other process industries, there is also a strive within the steel industry to recover waste products and to close the cycle.
Several different methods are known to try to regenerate the free acids (HNO 3 and HF) of the spent pickling liquid. A technique for this, which has been used for long by the present applicant, is the acid retardation process, commonly referred to as SAR (Scanacon Acid Retardation). A SAR plant operates to keep the metal concentration in the pickling bath at a low and stable level, and consists of one mechanical and one chemical process step. The mechanical step separates the acid and the metal sludge (metal oxide, metal fluoride), in a solid phase. The chemical step separates the acid and dissolved metal ions, by aid of a resin bed. From the SAR plant, a free concentrated acid with a low metal content is recycled back to the pickling bath. In order to recover yet more free nitric acid an electro-dialysis step can be used that separates anions and cations in the acid by means of membrane technique. The separation of ions are accelerated by an electrical DC-source. The separated metal ions, together with a weak free acid, and the sludge, are pumped to the neutralizing plant for destruction.
Another technique, called the Pyromar process, makes use of thermal decomposition of metal fluoride complexes in order to recover hydrofluoric acid, nitric acid and metals. By spray-calcination, a spent pickling liquid is converted to gas phase, where after it can be converted to a reusable acid by one or more absorption columns. The metals form metal oxides and must be subjected to reduction before being used again in the melting shop. The process has several drawbacks. Large amounts of nitrous fumes (NO x ) are formed by the spray-calcination, and these fumes must de destroyed by e.g. selective catalytic removal control (SCR). By the formation of NO N , large amounts (about 30-40%) of the nitric acid disappear, which causes an imbalance in the recovered amounts of hydrofluoric acid and nitric acid. Yet another drawback is that the metal oxides is in dust form, has a low density (0.5 g/cm 3 ), and that it contains high amounts of fluorides (>1%) that make it difficult to reduce the oxide product to a metallic form.
Yet another technique is called OPAR (Outokumpu Pickling Acid Recovery), in which sulphuric acid is used to decompose the metal fluoride complexes in the spent pickling liquid, by reacting with it and forming metal sulphates. The mixed acid of HNO 3 and HF, thus recovered, is separated by evaporation and condensation. The condensate is recycled back to the pickling bath, and metal sulphates formed in the process are heat treated, filter pressed and finally neutralised by calcium hydroxide and spent slag from the melting shop. The process is very costly and the neutralisation process results in a volume increase of 4-5 times, thereby generating large amounts of metal calcium sulphate and metal hydroxide sludge that has to be dumped. No technique for recycling metal oxides and sulphuric acid exists today.
In the neutralisation plant, the spent pickling liquid is neutralised by calcium hydroxide, Ca(OH) 2 , whereby a sludge results that consists of different metal hydroxides Me(OH) x , calcium fluoride (CaF 2 ) and calcium sulphate (CaSO 4 ). Today, such sludge is dumped.
In case of rain, there is a risk that some metals are leached out from the landfill, which means that the leaching water has to be handled and returned to the neutralisation plant.
During recent years, more stringent environmental demands have among other things led to stronger demands on landfill designs, which has resulted in highly elevated costs. Furthermore, a landfill tax may be introduced in the future. This has led to commenced investigations considering the possibility to keep down the amount of dumped sludge.
In Swedish patent no. SE 519776 of the present applicant, a method of reutilising metal-containing hydroxide sludge from a pickling step, is disclosed. The hydroxide sludge is mixed with an admixture having a content of a substance in group 14 of the periodic table, and is allowed to solidify by hardening or polymerisation, whereby the water content sinks to below 15%. The solidified mixture may then be recycled to a steel heat in connection with steel production in an arc furnace. The method also allows for powdery or finely dispersed residual products comprising metals, metal oxides and metal hydroxides, to be recycled to the steel manufacturing. It is also shown that the metals in the product go into the steel heat, that carbon leaves as carbon dioxide, water as water vapour (in small amounts), and that silicon, oxides, fluorides etc. go into the slag. The drawbacks of the method are that fluorides wear on the arc furnace lining, and that water must be driven off which increases the processing time in the arc furnace.
It is known from DE 36 34 106 to use a pickling agent distillation residue containing metal salts, such as a fluoride-containing component, in the production of a slag-forming additive for steel production. Also, a method for production of the slag-forming additive is described, which comprises distillation of the pickling liquid in order to drive off the free acids nitric acid and hydrofluoric acid, and to crystallize metal fluorides as moist sludge. Thereafter, the sludge is filtered in order to remove additional water and acid, and the dewatered sludge is mixed with caustic lime, CaO. This mixture can be added to a steel heat as a slag-forming additive. The slag-former will be relatively porous, which makes it difficult to handle. Any remaining moist may also cause steam explosions, and gaseous components will give increased NO x emissions constituting a load on the gas cleaning plant of the steel works. Other drawbacks of the method are that the distillation process is costly, and that it is difficult to recycle the nitric acid. About 40% of the nitric acid leaves together with the steam that is driven off, and this nitric acid must be destroyed in the SCR in the gas cleaning plant.
BRIEF ACCOUNT OF THE INVENTION
The invention relates to the handling of hydroxide sludge formed in the neutralisation of spent metal-contaminated pickling agents from a pickling step for steel, preferably stainless steel. The controversial idea forms the basis of the invention, that instead of previously focusing on recovery of the metals of the hydroxide sludge, now focusing on the calcium fluoride content, and considering this calcium fluoride to be a resource instead of a load. The present applicant has striven to find a method that enables handling of the calcium fluoride in the hydroxide sludge, in order to use it as a replacement for natural fluorspar (commonly called flux) as a fluxing agent. This is achieved by a method of producing a fluxing agent that can be used in production of steel, preferably stainless steel, characterised in that as a raw material for the production of said fluxing agent is used a hydroxide sludge resulting from neutralisation of metal-contaminated pickling liquid from a pickling step for a steel, said hydroxide sludge containing at least one fluoride-containing compound, and that said hydroxide sludge is calcined. The invention also provides a method in connection with steel production, preferably stainless steel, comprising production of a steel heat and decarburization of the steel heat, whereby a slag is formed on top of said steel heat, characterised in that a product according to the invention is added to said slag. Preferably, the product is added to the slag in an amount that partly or totally corresponds to the requirement of CaF 2 in order to achieve a desired fluxing effect.
By the invention, it is also possible to achieve one or some of the following advantages:
hydroxide sludge can be recycled to the steel production essentially without any process drawbacks hydroxide sludge can be recycled to the steel production essentially without any health hazards to the personnel the metals in the hydroxide sludge can be recovered hydroxide sludge may replace natural fluorspar essentially without impairing the properties of the produced steel hydroxide sludge already dumped and originating from acidic, metal-contaminated pickling liquids, can be taken care of hydroxide sludge can be processed into a mechanically stable product that may constitute a fluxing agent a fluxing agent can be produced by a method that in its essentials is simple and cost-efficient a fluxing agent can be produced essentially without health hazards for the personnel
The invention has been developed primarily for use in connection with the production of stainless steels, but it can also be used in connection with other types of steel production, such as production of carbon steel.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 is a flowsheet for the process,
FIG. 2 shows a graph over the contents of Cr 6+ in an exhaust emission control plant.
DETAILED DESCRIPTION OF THE INVENTION
The inventive process is described below with reference to the flowsheet in FIG. 1 .
Acidic, metal-contaminated and spent pickling liquids that can be handled according to the invention are chemically acidic pickling liquids 1 as well as neutral pickling liquids for electrolytic pickling. Such spent pickling liquids comprise residual acids, such as hydrofluoric acid, nitric acid, sulphuric acid, salts of such acids, including sodium sulphate e.g., and dissolved metal fluorides and metal oxides. In connection with the method, a per se known neutralisation 2 of the spent pickling liquid is performed to a pH of about 9-10, by addition of alkali, usually milk of lime, Ca(OH) 2 , but also other alkaline additives may be used, for example CaCO 3 , NaOH. Prior to the neutralisation chromium reduction of the liquid from the neolyte pickling step 9 (pH 6-6.5) may take place 3 . Regeneration of free acids in the pickling acids is performed in a SAR-step 4 and electro-dialysis step 5 . Reduction of nitrous fumes (NO x ) can be obtained by selective catalytic removal control (SCR) or hydrogen peroxide treatment 10 .
After the neutralisation, the neutralised pickling liquid is dewatered 6 , suitably mechanically in a filter press e.g., to a dry substance content of at least 30% by weight, preferably at least 50% by weight and up to 80% by weight, but normally not more than up to 70% by weight. Effluent water containing some nitrates (Ca(NO 3 ) 2 , pH 9-10) can be led to the recipient.
The dewatered product is called hydroxide sludge. The hydroxide sludge contains e.g. CaF 2 , CaSO 4 and Fe-, Cr-, Ni-hydroxides and Ca- or Fe-molybdate, at least in the case that hydrofluoric acid is used in the pickling liquid and in the case of stainless steel production. The hydroxide sludge is dried and calcined or sintered 7 to a mechanical stable product before it is added as a fluxing agent in the AOD-converter 8 in the steel production.
With the purpose of finding suitable methods for treatment of the hydroxide sludge, extensive experiments have been conducted in order to obtain a product capable of constituting a fluxing agent.
Undertaken Experiments
Introductory experiments for the treatment of hydroxide sludge have comprised:
calcination and melting in a 3 kg Tamman furnace (>1500° C.), melting in a 20 kg rotating furnace, calcination in a small scale Kanthal furnace (1100° C.), calcination in a bell-type furnace, 500 kg/heat, calcination in a pilot scale Kaldo converter (6 tons), by aid of a LPG burner, drying in a drying chamber (200° C.), treatment in a pilot scale DC furnace (10 tons and 3 MW).
Of these experiments, it is the calcination experiments in an electrically heated, stationary bell-type furnace and the calcination experiments in an LPG heated, rotating Kaldo converter that will be described further. By these experiments, a well sintered, mechanically stable and dustless product has been achieved, which product has then been used in subsequent experiments for evaluation of the properties of the calcined sludge as a fluxing agent in a converter instead of or in combination with regular fluorspar.
In a preferred embodiment of the invention, an electrically heated, stationary furnace (of bell-type) is used for the calcination of hydroxide sludge. From the description below, it is evident that this results in a product having very good properties in terms of mechanical stability, sintering degree and piece/particle size, but according to undertaken pilot experiments, a Kaldo converter can also be used for the calcination. Furthermore, undertaken experiments of calcining in a rotary kiln have shown to give a stable product. These experiments will not be described further since the hydroxide sludge had an exceptional high moisture content of 55-60% which resulted in abnormal problems during the calcining. However, one conclusion from the experiment is that the fines fraction is likely to be reduced if the moisture content in the hydroxide sludge and the rotating speed of the rotary kiln are sufficiently low.
The process for calcination of hydroxide sludge in a stationary furnace (bell-type) or rotary kiln which is electrically heated or heated by LP-gas or oil, can be described according to the following:
heating to 150-200° C., evaporation of free water in the sludge heating to 600-900° C., evaporation of crystal water, whereby the material becomes completely dehydrated heating to 1000-1200° C., sintering to a mechanically stable product (hydroflux)
The process for calcination of hydroxide sludge in a converter (Kaldo converter type) which is LPG heated, can be described according to the following:
a) heating to 150-200° C., evaporation of free water in the hydroxide sludge
b) heating to 600-900° C., chemically bonded water leaves
c) heating to 1200-1300° C., the hydroxide sludge melts
d) discharging the molten hydroxide sludge from the furnace to cool down to ambient temperature during solidification to form a mechanically stable product (hydroflux)
e) crushing of the solidified hydroflux product
Pilot Experiments
For the calcination was used 10 tons of hydroxide sludge having a relatively high sulphur content, and 2 tons of hydroxide sludge having a relatively low sulphur content. The high sulphur content hydroxide sludge was split into 3 portions that were calcined in a Kaldo converter after first having been dried in a chamber furnace at 200° C. Portions 1 and 2 were heated to 900° C. in the Kaldo converter, and portion 3 was melted in the Kaldo converter. The low sulphur content hydroxide sludge was split into two portions, whereof one portion, portion no. 4, was dried in a chamber furnace according to the above, and the other portion, portion no. 5, was air dried at ambient temperature. These two low sulphur content portions were calcined in a bell-type furnace.
The average composition of the two categories of hydroxide sludge at 85% dry content, i.e. after drying at 110° C. but before calcination, are shown in the table below.
TABLE 1
CATEGORY
Fe(OH) 3
Cr(OH) 3
Ni(OH) 2
MoO 3
CaF 2
CaSO 4
C
Na 2 O
CaO
High sulphur content
23.4
10.4
3.2
0.3
44.2
3.2
0.95
0.1
9.2
Low sulphur content
24.1
5.1
3.6
0.3
43.6
0.3
0.5
0
8.5
In the table below, properties and amounts of the calcined hydroxide sludge that was obtained, and the temperature during calcination for the respective portions, are shown.
TABLE 2
TEMPERATURE
PORTION
WEIGHT (KG)
(° C.)
PROPERTIES
1
Totally 1850
900
small, loosely sintered
2
lumps, 10-20 mm,
of poor strength
3
450
1300
Hard, molten lumps,
must be crushed
before use
4
Totally 670
1000-1100
Hard, sintered lumps
5
having a size
of 10-40 mm
During calcination, the carbon content was decreased by carbon leaving as carbon dioxide. The carbon originates from calcium carbonate that accompanies the lime in the neutralisation process. The materials from portions no. 1 and 2 were agglomerated, but had a very poor strength and small size. The material from portion no. 3 was very much similar to natural fluorspar, in respect of strength and size.
During calcination in the bell-type furnace, it was noted that the carbon content was low to even in this case. The material from portions no. 4 and 5 had very good strength properties, in practice equally good as the molten material from portion no. 3.
The materials from portions no. 1 and 2 were judged unsuitable for continued experiments, due to the risk of dusting and due to poor strength. The materials from portions no. 3, 4 and 5 had none or a very small ratio of fines fraction, and were judged suitable to be used in subsequent experiments. The composition of these materials is shown in the table below (% by weight):
TABLE 3
PORTION
Fe 2 O 3
Cr 2 O 3
NiO
MoO 3
CaF 2
CaSO 4
C
Na 2 O
CaO
SiO 2
MgO
1
25.2
11.8
3.1
0.3
47.8
3.0
0.01
0.1
7.1
1.8
0.6
2
25.4
11.6
3.0
0.2
47.6
2.9
0.01
0.1
7.3
1.9
0.6
3
25.3
11.7
3.0
0.2
41.0
2.8
0.01
0.1
14*)
2.0
0.5
4
27.9
6.1
3.4
0.3
51.5
0.4
0.02
0
10.5
1.9
0.4
5
27.6
5.9
3.5
0.2
51.2
0.4
0.02
0
10.8
2.1
0.4
*)Given as residual content up to 100%
During the experiments, no measurements were made in respect of occurrence of HF or SO 2 , both of which are irritating already at low contents. The table shows however, concerning portion no. 3, that CaF 2 is partially lost at temperatures close to 1300° C. No loss of CaF 2 has been noted concerning portions no. 1, 2, 4 and 5.
Natural fluorspar normally used in the melting shop, has the following approximate composition (% by weight):
TABLE 4
Composition of natural fluorspar
PORTION
CaF 2
SiO 2
CaCO 3
MgO
Fe 2 O 3
S
K 2 O
Pb
P
Fluorspar
≧90
7.5-8
≦0.5
~0.05
~0.2
~0.03
~0.02
≦0.01
≦0.01
In principle, the calcined hydroxide sludge is a chemically produced synthetic fluorspar, although having a maintained content of metal oxides and a small surplus of calcium oxide. In the following, the product is called hydroflux. The subsequent experiments aimed at investigating the properties of the hydroflux as a fluxing agent. A secondary purpose was to investigate whether the metal oxides would be allowed to be reduced into the steel heat.
Nine heats of 6 tons each and being of a stainless steel of the type ASTM 304 were produced in an arc furnace, for the pilot experiments. The respective heats were tapped into a heated tapping ladle, and were transported to a 6 ton AOD-converter for decarburization. The amount of slag accompanying from the arc furnace, was minimised. Before the experiments, the AOD-converter in question was provided with a new lining, in order thereby to be able to decide whether the hydroflux had an influence on the same.
The nine heats constituted test materials for an experimental campaign that was run in series in the AOD-converter. The experiments were conducted with varying mixing ratios of natural fluorspar and hydroflux. In five experiments, hydroflux from portions no. 4 and 5 were used, since this hydroflux had lower sulphur content, but two experiments with hydroflux from portion no. 3 were also included in the experimental campaign. Two reference heats with solely natural fluorspar were run. In order to reduce the metal oxides, primarily Cr 2 O 3 but also Fe 2 O 3 , and NiO, it was found that an extra addition of FeSi was needed. The amount of FeSi required for the metal reduction is proportional to the metal oxides in the hydroflux. Moreover, an extra addition of CaO is required to maintain the basicity of the slag, which should be about 1.5-2.0. These extra additives result in that the amount of slag increases with up to 10%.
In the pickling, different types of steel result in different amounts of metal hydroxides in the sludge. One advantage of the invention is that you are not bound to use hydroxide sludge from the pickling of the same or essentially the same type of steel as the one you intend to produce. Therefore, the skilled person will realise that the invention is very easy to integrate in the existing steel production process. Thanks to the invention, it is also possible to handle already dumped hydroxide sludge, converting it to a valuable fluxing agent, and recovering its metal content.
The mixing ratios of the respective heats of the pilot experiment campaign are given in the table below. The numbers in parenthesis relate to the portion in question of the hydroflux:
TABLE 5
Mixing ratio of natural fluorspar and hydroflux
Heat no.
CaF 2 from natural fluorspar
CaF 2 from hydroflux
1
100
0
2
50
50
(4 + 5)
3
50
50
(4 + 5)
4
60
40
(4 + 5)
5
50
50
(4 + 5)
6
25
75
(4 + 5)
7
65
35
(3)
8
100
0
9
50
50
(3)
The AOD-process may be described according to the following:
Charging of 6 tons of steel from a tapping ladle Temperature measurement directly after charging Lollipop and chill mould testing for analysis of carbon content and steel composition
Decarburization:
Addition of lime and dolomite just after commenced oxygen blowing, guideline value C=0.40% Addition of lime, continued oxygen blowing and also nitrogen gas, guideline value C=0.15% Continued oxygen and nitrogen gas blowing, guideline value C=0.07%. Sampling for carbon content and temperature.
Optional addition of cooling scrap. Sampling for carbon content and temperature.
Reduction:
Addition of hydroflux, lime, FeSi, fluxing agents (natural fluorspar), SiMn, optionally cooling scrap. Argon gas blowing for stirring.
Sampling of steel, slag and temperature
Tapping
In addition to the above described process steps, a continuous measurement of gas flows to the AOD-converter (O 2 , N 2 ), exhaust gas flows from the AOD-converter (CO, CO 2 , O 2 ), and material weight to different hoppers, took place. In order to investigate whether the use of hydroflux generates additional Cr 6+ , the content of Cr 6+ was analysed in the water pool of a venturi scrubber in an exhaust emission control plant, see FIG. 2 . The content was analysed after the respective experimental heats. The arrows indicate the reference heats with addition solely of natural fluorspar. From these measurements it is clear that the use of hydroflux does not give rise to increased Cr 6+ formation, compared to the use of natural fluorspar, which is seen in FIG. 2 .
The slag samples from the 9 experimental heats were analysed and their compositions are given in the table below.
TABLE 6
Composition of slag samples from the 9 experimental heats
AOD 1
AOD 2
AOD 3
AOD 4
AOD 5
AOD 6
AOD 7
AOD 8
AOD 9
Cr 2 O 3
5.0
3.6
1.1
1.0
0.2
0.2
0.3
0.4
0.1
FeO
0.4
0.6
1.3
0.3
0.2
0.3
0.4
0.6
0.3
MgO
3.7
4.3
7.4
10.6
9.1
8.6
10.3
10.2
10.1
SiO 2
32.7
31.6
32.6
30.4
30.4
29.6
29.6
31.5
30.4
CaO
54.7
57.6
56.2
56.4
62.7
62.9
60.2
57.5
61.8
F
4.6
4.4
4.2
4.5
3.9
5.0
4.1
3.6
3.5
CaF 2
9.5
9.0
8.6
9.2
8.0
10.2
8.4
7.4
7.2
CaO calc
47.9
51.1
50.2
49.8
56.9
55.5
54.2
52.2
56.6
MnO
1.2
0.9
0.4
0.4
0.1
0.1
0.1
0.2
0.1
Al 2 O 3
0.7
0.9
1.4
2.4
1.6
1.6
2.7
2.5
1.9
CaSO 4
<0.3
<0.3
<0.3
<0.3
<0.3
<0.3
2.7
<0.3
2.7
Basicitet
1.5
1.6
1.5
1.6
1.8
1.9
1.8
1.7
1.9
It is clear from the table that a few introductory experimental heats were required to find the optimum conditions for reduction of the chromium oxide. During these introductory experimental heats, the required amount of extra FeSi was found. Experimental heats no. 7 and 9 were produced with sulphuric containing hydroflux, and in these cases a small increase of the sulphur content in the slag could be noted. An analysis of the sulphur content of the steel indicates that sulphur is not re-introduced into the heat, and therefore one may assume that a small part of the sulphur ends up in the slag and the main part leaves with the exhaust gases as SO 2 .
Experience from the conducted pilot experiments surprisingly shows that the hydroflux is also suitable for use as a fluxing agent in connection with carbon steel production. In connection with carbon steel production, the use of fluorspar has, as is well known, mainly been terminated. Instead, lime and iron oxide is used. The applicant would all the same point out the option of using hydroflux in these applications. In such a process, it is not necessary to reduce the metal oxides in the slag, why the extra addition of FeSi and CaO can be omitted. The purpose of CaF 2 in the hydroflux is also in this case to render the slag fluid.
As a conclusion, the pilot experiments have shown that:
Hydroxide sludge can be calcined into a mechanically stable product, suitable for use as a fluxing agent in an AOD-converter. No dusting has been observed. The product, so called hydroflux, can be produced by a simple and cost-efficient method The use of hydroflux has not shown any negative effects on the reduction process in the AOD-converter The formation of slag by aid of hydroflux is equivalent with the one aided by natural fluorspar, and the slag has a good reactivity The reduction slag in the AOD-converter had essentially the same properties independent of if hydroflux or natural fluorspar was used, among other things a low viscosity and the same colour. The extra metal oxides in the hydroflux may be efficiently reintroduced into the heat by addition of FeSi. No uptake of S and C in the heat could be observed at the use of hydroflux.
Full-Scale Experiments
Three sets of full scale experiments have been performed:
1. Initial test campaign. Screened, low sulphur hydroflux added to the AOD-converter in tilted position 2. 2 nd test campaign. Screened, high sulphur hydroflux added to the AOD-converter in upright position 3. 3 rd test campaign. Unscreened, high sulphur hydroflux added to the AOD-converter in upright position
Initial Test Campaign
For full scale experiments, four heats were produced in an arc furnace, each of about 90 tons in a sequence of a steel grade called ASTM 304L, i.e. of type ASTM 304 with low carbon content. By “sequence” is meant a production of several heats with the same steel code, after each other. The first heat of the sequence is an experimental heat, and the rest are reference heats. Routine samples of the steel's initial composition were taken from the arc furnace in the transfer ladle, before the de-slagged steel was discharged into an AOD-converter and the decarburization was commenced. After the decarburization with oxygen and argon in the AOD-converter, the reduction was commenced.
Hydroflux corresponding to about 40% of the required CaF 2 was added from a box that usually is used for cooling scrap. The hydroflux had a particle size of at least 12 mm, without any fines, and was well sintered and mechanically stable. The addition was made as a first step in the reduction, and with the AOD-converter in tilted position. Thereafter, the converter was raised to operating position, and the rest of the reduction mixture was added from the hoppers of alloying elements above the converter. The composition of the used hydroflux is shown in the table below.
TABLE 7
Composition of the hydroflux (% by weight)
used in the initial campaign
CaF 2
51
Fe 2 O 3
27
Cr 2 O 3
5
NiO
4
CaSO 4
0.3
SiO 2
2
S
0.06
C
0.01
In order to form a reducing slag, the following additions were made to the AOD-converter during the reduction step:
TABLE 8
Additives to the reduction step (kg)
Heat no.
Test heat
Reference 1
Reference 2
Reference 3
FeSi, (Si, 75%)
1302
1063
1653
1331
FeSiMn
1687
1702
1699
1412
Burnt lime (CaO)
1535
1375
2814
1752
Fluorspar
750
983
1333
1140
(CaF 2 , 90%)
Hydroflux
780
—
—
—
(CaF 2 , 51%)
The following amounts of steel (tons) have been charged into and discharged from the converter:
TABLE 9 Steel amounts in the AOD-converter (tons) Test heat Reference 1 Reference 2 Reference 3 Initial Weight 92.0 87 83 86.1 Final Weight 101.5 99.7 100.2 94.6
Results from the Production of the Four Sequence Heats
The production of the four sequence heats followed a normal course. Normal production samples and extra slag samples were taken from the reduction step. Corresponding samples were taken from the three reference heats. The analyses of the steel samples after reduction are shown in table 10. The slag samples from the reduction are shown in Table 11.
TABLE 10
Steel samples (ASTM 304L) from the
AOD-converter after reduction
Element
Test heat
Reference 1
Reference 2
Reference 3
C
0.015
0.013
0.016
0.017
Si
0.30
0.19
0.22
0.12
Mn
1.65
1.61
1.46
1.53
P
0.023
0.023
0.024
0.021
S
0.010
0.009
0.013
0.011
Cr
18.18
18.00
17.72
17.91
Ni
8.17
8.05
8.13
8.09
Mo
0.34
0.31
0.32
0.41
Cu
0.25
0.22
0.22
0.20
N
0.092
0.077
0.079
0.077
TABLE 11
Slag samples after reduction (% by weight)
Element
Test heat
Reference 1
Reference 2
Reference 3
SiO 2
35.4
35.6
37.2
36.7
MnO
1.2
1.2
2.4
1.4
P 2 O 5
0.0
0.0
0.0
0.0
S
0.04
0.03
0.01
0.05
Cr 2 O 3
1.0
1.1
2.1
1.3
NiO
0.05
0.04
0.04
0.04
TiO 2
0.30
0.26
0.36
0.33
Al 2 O 3
1.6
1.0
0.8
1.4
V 2 O 5
0.01
0.01
0.02
0.02
MgO
5.2
6.1
5.3
5.6
CaO
55.7
55.8
52.7
54.9
CaO, Calc.
49.9
50.8
47.5
49.0
FeO
0.3
0.2
0.3
0.3
CaF 2
8.1
6.9
7.1
7.4
Basicity
1.4
1.4
1.3
1.4
The addition of hydroflux in the initial campaign worked according to the expectations, and the observations can be summarised as follows:
No dusting or strong reaction took place at the addition of the hydroflux The appearance of the slag was similar, and it was well fluid for all four heats The content of Cr 2 O 3 in the reduction slag was equal in all heats No changing of properties for the ladle furnace slag were observed before tapping into the tundish in the continuous casting plant for the test heat in comparison with the reference heats.
Results of the Evaluation of the Final Material
The test heat and the reference heats have been compared in respect of the quality of the materials. 12 steel strips were made from the material, and the qualities of these were investigated according to the following:
Investigation of the weldability of the strips Investigation of slag inclusions in the strips Establishing strength values Manual inspection of the surface quality in respect of surface defects
Comparison of Weldability
Comparative welding tests have been performed by certified welders according to a method called MMA/SMAW, using an electrode type called 308L/MVR AC/DC. No visual difference could be seen in respect of weldability, such as flow and slag release, when comparing test and reference heats.
Comparison of Slag Inclusions in the Materials
All together, 6 samples have been evaluated in respect of the occurrence of slag inclusions. 3 samples were taken from the test heat and 1 sample each was taken from the reference heats. The samples have been analysed in a PC controlled metal microscope at Avesta Research Centre (ARC) and according to regulation SS 111116, i.e. the method that the ARC uses for routine control of slag inclusions in stainless materials. All 6 samples show low occurrence of slag inclusions.
Strength Analysis and Manual Inspection of Surface Quality
The strength tests were approved for all 12 strips. The surface inspection revealed no deviations as compared to other strips produced during the same period in the strip mill in question.
2 nd Test Campaign
Twenty-two heats in three sequences of the steel grades called ASTM 304L and ASTM 316L were produced. Seven reference heats were included in the sequence. A total of 19 tons of hydroflux was added to the heats in various amounts. 50-100% out of the total requirement of fluxing agent in each heat respectively was provided by addition of hydroflux which can be seen in table 13 below. Three reference heats were produced with natural fluorspar as the only fluxing agent. The hydroflux was added in a conventional manner to the AOD-converter in upright position from a hopper above the converter.
The hydroflux used was produced in a stationary electric furnace where the hydroxide sludge was dried and calcined/sintered at a final temperature of 1050° C. The hydroflux was screened to a particle size above 4 mm. The hydroxide sludge used originated from four different neutralisation plants that was mixed. In this way the hydroflux produced obtained realistic variations in its compositions depending on that particular mixture. The composition of the hydroflux varied within the ranges shown in table 12 below.
TABLE 12
Variations in the composition of the used hydroflux
(% by weight) in the test campaign
CaF 2
40-60
Fe 2 O 3
22-30
Cr 2 O 3
5-8
NiO
3-5
CaO
2-20
SiO 2
1.5-2
CaSO 4
0.5-14
C
0.01-0.02
TABLE 13 Additives (kg) to the heats in the test campaign Heat Steel grade no. CaF 2 kg CaO kg 75 FeSi FeSiMn Hydroflux 2323 844117 1006 856 1723 0 0 2323 844118 479 854 1610 0 1027 2323 844119 517 1704 2125 0 1040 2323 844120 502 1760 2216 0 1047 2323 844121 516 1552 2200 0 1043 2323 844122 1002 1697 2051 0 0 1358 844123 1021 1118 1175 1402 0 1358 844124 521 1321 1332 1354 1037 1358 844125 523 937 1302 1227 1027 1358 844126 214 1509 1381 1321 1530 1358 844127 208 1405 1218 1243 1520 1358 844128 0 2500 1556 1122 2017 1358 844129 0 946 1071 1335 1832 1358 844130 986 1252 1297 1252 0 2323 844167 258 1859 2324 0 1515 2323 844168 262 1168 2027 0 1448 2323 844169 981 1083 1786 0 0 1358 844172 1219 2766 1467 1054 0 1358 844173 631 2032 1469 1362 820 1358 844174 535 2105 1100 1478 1200 1358 844175 547 1300 901 1736 994 1358 844176 965 766 826 1887 0
Results from the Production of the Nineteen Sequence Heats
The production of the nineteen sequence heats followed a normal course. Normal production samples and extra slag samples were taken from the reduction step. Corresponding samples were taken from the seven reference heats. The analyses of the steel samples after reduction are shown in table 14, 16 and 18 and the slag samples from the reduction are shown in Table 15, 17 and 19.
TABLE 14
Steel samples (ASTM 316L) from the AOD-converter after reduction
Heat
844117
844118
8488119
844120
844121
844122
844167
844168
844169
Element
REF 4
Test 2
Test 3
Test 4
Test 5
REF 5
Test 6
Test 7
REF 6
C
0.019
0.015
0.014
0.016
0.012
0.013
0.011
0.012
0.012
Si
0.40
0.47
0.55
0.43
0.35
0.39
0.42
0.43
0.46
Mn
0.91
0.84
0.85
0.84
0.97
0.93
1.03
0.99
0.89
P
0.026
0.023
0.024
0.024
0.027
0.026
0.026
0.026
0.026
S
0.007
0.006
0.008
0.009
0.012
0.008
0.005* )
0.007* )
0.004
Cr
16.92
16.72
16.66
16.64
16.89
16.70
16.73
16.84
16.92
Ni
10.15
10.16
10.19
10.16
10.36
10.16
10.09
10.12
10.06
Mo
1.94
2.00
2.04
2.00
2.10
2.03
2.18
2.00
1.96
Cu
0.45
0.33
0.33
0.34
0.42
0.44
0.34
0.37
0.35
N
0.053
0.039
0.052
0.058
0.053
0.053
0.040
0.055
0.053
*)≈75% out of the total requirement of fluxing agent added as hydroflux with 4-6% CaSO 4 doesn't effect the sulphur content in the steel
The hydroflux was added in connection to the reduction step. In order to evaluate the efficiency of the fluxing agent the amounts of Cr 2 O 3 remaining in the slag was measured. A well working reduction produces a slag where the amount of Cr 2 O 3 remaining in the slag is max. 1.0%.
TABLE 15
Slag samples after reduction ASTM 316L (% by weight)
Heat
844117
844118
8488119
844120
844121
844122
844167
844168
844169
Element
REF 4
Test 2
Test 3
Test 4
Test 5
REF 5
Test 6
Test 7
REF 6
S
0.20
0.15
0.13
0.11
0.13
0.16
0.13
0.14
0.12
F
4.4
3.6
4.5
3.8
4.1
4.2
4.3
3.9
5.1
MnO
0.2
0.2
0.2
0.3
0.3
0.2
0.3
0.4
0.2
P2O5
0
0
0
0
0
0
0
0
0
Cr2O3
0.7
0.5
0.7
0.6
0.5
0.5
0.4
0.4
0.3
NiO
0.04
0.04
0.04
0.05
0.04
0.04
0.04
0.04
0.05
TiO2
0.33
0.22
0.17
0.19
0.18
0.27
0.19
0.28
0.25
V2O5
0.01
0.01
0.02
0.01
0.02
0.03
0.02
0.01
0.01
Al2O3
1.7
1.2
1.2
1.2
1.2
1.3
1.0
1.1
1.1
CaF2
9.1
7.3
9.1
7.7
8.4
8.5
8.7
8.0
10.5
CaO
59.5
58.1
59.0
58.5
57.6
58.7
59.0
57.4
59.2
CaO
ber 53.0
52.8
52.4
53.0
51.6
52.6
52.7
51.6
51.7
FeO
0.1
0.1
0.2
0.2
0.2
0.1
0.2
0.7
0.3
MgO
5.8
6.4
5.3
5.1
5.6
5.6
7.6
6.4
6.6
Basicity
1.6
1.5
1.6
1.5
1.6
1.6
1.6
1.5
1.6
TABLE 16
Steel samples (ASTM 304L) from the AOD-converter after reduction
Heat
844123
844124
844125
844126
844127
844128
844129
844130
Element
REF 7
Test 8
Test 9
Test 10
Test 11
Test 12
Test 13
REF 8
C
0.020
0.015
0.015
0.015
0.013
0.020
0.010
0.015
Si
0.36
0.19
0.26
0.28
0.26
0.27
0.21
0.20
Mn
1.62
1.67
1.66
1.68
1.68
1.57
1.65
1.67
P
0.023
0.027
0.029
0.029
0.029
0.028
0.029
0.026
S
0.006
0.006
0.011
0.007
0.006
0.015*)
0.011*)
0.010
Cr
17.88
17.85
17.95
18.08
17.97
17.77
17.86
18.00
Ni
8.17
8.08
8.09
8.09
8.05
8.09
8.03
8.05
Mo
0.36
0.36
0.38
0.37
0.42
0.37
0.36
0.36
Cu
0.18
0.20
0.33
0.30
0.30
0.30
0.31
0.29
N
0.079
0.073
0.085
0.079
0.074
0.068
0.083
0.081
*)100% out of the total requirement of fluxing agent added as hydroflux with 4-6% CaSO 4 has a marginal effect on the sulphur content in the steel
TABLE 17
Slag samples after reduction ASTM 304L (% by weight)
Heat
844123
844124
8488125
844126
844127
844128
844129
844130
Element
REF 4
Test 2
Test 3
Test 4
Test 5
REF 5
Test 6
Test 7
S
0.070
0.10
0.27
0.28
0.23
0.04
0.17
0.13
F
4.4
4.3
4.9
5.5
5.3
4.1
4.1
3.4
SiO2
33.2
33.2
32.5
31.9
31.6
34.3
32.3
34.3
MnO
0.4
0.5
0.5
0.3
0.3
1.1
0.6
0.6
P2O5
0
0
0
0
0
0
0
0
Cr2O3
0.4
0.4
0.3
0.2
0.2
1.0
0.4
0.5
NiO
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
TiO2
0.37
0.24
0.23
0.25
0.27
0.30
0.26
0.30
V2O5
0.01
0.01
0.01
0.01
0.01
0.02
0.01
0.01
Al2O3
0.9
0.9
0.9
1.0
1.0
1.1
0.9
1.1
CaF2
9.0
8.7
10.0
11.3
10.9
8.4
8.3
6.9
CaO
58.2
57.7
57.5
58.8
58.8
54.8
58.4
57.2
CaO calc
51.7
51.4
50.3
50.7
51.0
48.8
52.4
52.2
FeO
0.1
0.1
0.2
0.1
0.1
0.4
0.2
0.1
MgO
6.7
7.3
7.7
7.6
8.3
6.4
7.9
6.5
Basicity
1.6
1.5
1.5
1.6
1.6
1.4
1.6
1.5
TABLE 18
Steel samples (ASTM 304L) from the AOD-converter after reduction
Heat
Ele-
844172
844173
844174
844175
844176
ment
REF 9
Test 14
Test 15
Test 16
REF 10
C
0.012
0.013
0.014
0.016
0.014
Si
0.17
0.18
0.19
0.15
0.27
Mn
1.57
1.59
1.64
1.66
1.65
P
0.025
0.028
0.025
0.023
0.023
S
0.008
0.015* )
0.020* )
0.015* )
0.011
Cr
17.83
17.97
17.95
18.11
18.04
Ni
8.14
8.00
8.10
8.15
8.12
Mo
0.58
0.32
0.37
0.34
0.37
Cu
0.32
0.29
0.34
0.32
0.32
N
0.069
0.070
0.070
0.085
0.069
*)45-56% out of the total requirement of fluxing agent added as hydroflux with 12-14% CaSO 4 has a marginal effect on the sulphur content in the steel
TABLE 19
Slag samples after reduction ASTM 304L (% by weight)
Heat
844172
844173
844174
844175
844176
Element
REF 9
Test 14
Test 15
Test 16
REF 10
S
0.070
0.10
0.27
0.28
0.23
F
4.4
4.3
4.9
5.5
5.3
SiO2
33.2
33.2
32.5
31.9
31.6
MnO
0.4
0.5
0.5
0.3
0.3
P2O5
0
0
0
0
0
Cr2O3
0.4
0.4
0.3
0.2
0.2
NiO
0.04
0.04
0.04
0.04
0.04
TiO2
0.37
0.24
0.23
0.25
0.27
V2O5
0.01
0.01
0.01
0.01
0.01
Al2O3
0.9
0.9
0.9
1.0
1.0
CaF2
9.0
8.7
10.0
11.3
10.9
CaO
58.2
57.7
57.5
58.8
58.8
CaO calc
51.7
51.4
50.3
50.7
51.0
FeO
0.1
0.1
0.2
0.1
0.1
MgO
6.7
7.3
7.7
7.6
8.3
Basicity
1.6
1.5
1.5
1.6
1.6
Given the experiments performed hitherto, it seems that sulphur in the hydroflux does not significantly affect the steel production process. The main part of the sulphur leaves together with the effluent gas from the AOD-converter as SO 2 .
The addition of hydroflux in the 2 nd test campaign worked according to the expectations, and the observations can be summarised as follows:
The hydroflux could be transported to the hoppers without any negative influence on the mechanical properties The addition of hydroflux from the hoppers worked without any problems No dusting took place at the addition of the hydroflux The appearance of the slag was similar, and it was well fluid for all heats Variations within the content of CaF 2 didn't effect on the properties of the slag The content of Cr 2 O 3 in the reduction slag was equally low in all heats The basicity of the slag where the same (1.4-1.6) for all heats Natural fluorspar could be completely substituted to hydroflux without any negative effects Hydroflux with 14% CaSO 4 did not effect the sulphur content in the steel Hydroflux gave a somewhat more fluid slag than natural fluorspar No changing of properties for the ladle furnace slag were observed before tapping into tundish in the continuous casting plant
3 rd Test Campaign
Unscreened, high sulphur hydroflux added to the AOD-converter in upright position. Nine heats in a sequence of the steel grades called ASTM 304L were produced. Three reference heats were included with natural fluorspar as the only fluxing agent. A total of 7 tons of unscreened, high sulphur hydroflux was added into the six test heats in amounts of 50-75% out of the total requirement of fluxing agent in each heat respectively. The hydroflux was added in a conventional manner to the AOD-converter in upright position from a hopper above the converter. The hydroflux contained approximately 20% fines with particle sizes smaller than 4 mm. The composition of the hydroflux varied within the ranges shown in table 20 below.
TABLE 20
Variations in the composition of the used hydroflux
(% by weight) in the test campaign
CaF 2
45-60
Fe 2 O 3
24-30
Cr 2 O 3
5-9
NiO
3-5
CaO
2-24
SiO 2
1.5-2
CaSO 4
5-7
C
0.01-0.02
In order to form a reducing slag, the following additions were made to the AOD-converter during the reduction step in the campaign:
TABLE 21
Additives (kg) to the heats in the test campaign
Steel grade
Heat no
CaF 2 kg
CaO kg
75 FeSi
FeSiMn
Hydroflux
1358
451132
1000
800
850
1380
0
1358
451133
274
1492
1304
1518
1069
1358
451134
622
809
863
1387
1045
1358
451135
614
722
1196
1223
1060
1358
451136
1022
815
1029
1261
0
1358
451137
522
1361
1294
1396
1069
1358
451138
363
1557
1379
1520
1547
1358
451139
372
1482
1460
1276
1541
1358
451140
1027
1936
1574
1149
0
TABLE 22
Steel samples (ASTM 304L) from the AOD-converter after reduction
Heat
451132
851133
851134
851135
851136
851137
851138
851139
851140
Element
REF 11
Test 17
Test 18
Test 19
REF 12
Test 20
Test 21
Test 22
REF 13
C
0.012
0.013
0.014
0.016
0.014
0.018
0.018
0.017
0.016
Si
0.17
0.18
0.19
0.15
0.27
0.39
0.14
0.16
0.25
Mn
1.57
1.59
1.64
1.66
1.65
1.61
1.57
1.61
1.53
P
0.025
0.028
0.025
0.023
0.023
0.028
0.026
0.027
0.026
S
0.008
0.015* )
0.020* )
0.015* )
0.011
0.008
0.012*)
0.005
0.004
Cr
17.83
17.97
17.95
18.11
18.04
18.07
18.29
18.03
17.92
Ni
8.14
8.00
8.10
8.15
8.12
8.16
8.24
8.13
8.01
Mo
0.58
0.32
0.37
0.34
0.37
0.36
0.36
0.37
0.31
Cu
0.32
0.29
0.34
0.32
0.32
0.36
0.43
0.47
0.31
N
0.069
0.070
0.070
0.085
0.069
0.077
0.084
0.079
0.079
*)70% out of the total requirement of fluxing agent added as hydroflux with 5-7% CaSO 4 cause a small increase on the sulphur content in the steel
TABLE 23
Slag samples after reduction ASTM 304L (% by weight)
Heat
451132
851133
851134
851135
851136
851137
851138
851139
851140
Element
REF 11
Test 17
Test 18
Test 19
REF 12
Test 20
Test 21
Test 22
REF 13
S
0.13
0.09
0.17
0.08
0.16
0.12
0.12
0.15
0.09
F
5.5
3.0
5.5
4.5
5.4
4.2
4.2
4.1
4.4
SiO2
30.0
34.3
31.1
33.2
30.9
33.7
34.3
33.2
33.1
MnO
0.5
1.4
0.8
1.3
0.3
1.1
1.4
1.0
0.5
P2O5
0
0
0
0
0
0
0
0
0
Cr2O3
0.6
0.8
0.6
0.9
0.6
0.8
0.7
0.6
0.7
NiO
0.05
0.07
0.11
0.06
0.04
0.05
0.05
0.05
0.05
TiO2
0.25
0.37
0.25
0.27
0.23
0.21
0.19
0.24
0.15
V2O5
0.01
0.03
0.01
0.02
0.02
0.01
0.01
0.02
0.02
Al2O3
1.1
1.4
1.1
1.2
1.2
1.2
1.1
1.1
1.2
CaF2
11.3
6.2
11.3
9.1
11.1
8.7
8.6
8.4
9.1
CaO
59.5
55.7
56.8
54.6
61.1
57.2
56.2
56.0
58.8
CaO calc
51.4
48.7
48.7
48.1
53.1
50.9
50.0
49.9
52.3
FeO
0.4
0.7
1.3
0.6
0.1
0.4
0.4
0.6
0.3
MgO
9.2
7.1
7.5
7.8
7.6
6.7
6.5
7.1
6.9
Basicity
1.7
1.5
1.6
1.5
1.7
1.5
1.5
1.5
1.6
The experiments showed that fines with particle sizes of max 1-2 mm or less have a tendency to be caught by the mixing gas that is blown through the heat and these fines are transported and deposited in the gas cleaning plant which is undesired. Suitably the hydroflux is screened such that a hydroflux product with particle sizes of at least 2 mm is obtained. The fines fraction can be formed to briquettes whereby they can be used in the converter as well.
Results of the Evaluation of the Material Produced During 2 nd and 3 rd Campaign
The test heats and the reference heats all have been compared in respect of weldability, surface quality, slag inclusions and strength according to the same procedure as in the initial full scale experiments. Not a single defect has been observed.
Alternative Embodiments
In a preferred embodiment of the invention, an electrically heated, stationary furnace (of bell-type) is used for the calcination of hydroxide sludge. Performed experiments have showed that this results in a product having very good properties in tenns of mechanical stability, sintering degree and piece/particle size. However, the invention is not limited to this, but according to undertaken experiments, a Kaldo converter can also be used for the calcination. The person skilled in the art will realise that other types of equipments can be used too, for example a belt furnace, an electrical or LP-gas or oil-heated stationary or batch type furnace such as a tunnel kiln or a walking beam furnace, a CLU-, OBM- or LD-converter, enabling the production of a product having the desired properties.
In the pilot experiments, the hydroflux had a piece/particle size of between 12-40 mm. These experiments were conducted without any dusting tendencies of the hydroflux at the handling after calcination and at the recycling to the AOD-converter. In the pilot experiments, the hydroflux was added via a material hopper above the AOD-converter that was in an upright position. It is also possible to add the hydroflux after charging of the steel, while the converter is still in tilted position. In the full scale experiments, hydroflux of different particle sizes have been used. The experiments have shown that a hydroflux product according to the invention can be added to the AOD-converter in conventional manner, i.e. added from the material hoppers above the AOD-converter when the converter is in upright position. Suitably the hydroflux is screened such that a hydroflux product with particle sizes of at least 2 mm is obtained. The fines fraction can be formed to briquettes whereby they can be used in the converter as well.
The concept of the invention also comprises use of the hydroflux product in other applications in which natural fluorspar is used, e.g. in the slag purification that is performed directly before continuous casting in a ladle furnace. In such an application, it is conceivable to allow the hydroflux to have a particle size smaller than 10 mm, suitably smaller than 5 mm, preferably 2-4 mm, and to add it via a squirt, to the ladle furnace.
It is also realised that a calcined hydroflux that risks dusting or not to penetrate into the slag as is desired, can be packed in individual portions in order to allow handling and addition without said drawbacks.
In the experiments, the addition of the calcined hydroxide sludge has taken place in connection with a reduction step in an AOD-converter. The person skilled in the art will however realise that the invention is not limited thereto, but that the calcined hydroxide sludge can be used as a fluxing agent in connection with a decarburization and/or reduction step in some other equipment, such as a CLU-converter.
It is furthermore realised that the content of CaF 2 in the hydroflux can be varied because the product can be used as a supplement to natural fluorspar. In a preferred embodiment, the content of CaF 2 in the hydroflux is 40-65% by weight, but with the metal contaminated pickling agents occurring in various pickling plants as a starting point, it is likely that the content of CaF 2 will vary between 20 and 80% by weight.
According to a preferred embodiment, a hydroxide sludge is used that has a natural low content of sulphur, in the form of calcium sulphate. The sulphur content of a hydroxide sludge that has a natural low content of sulphur is less than 0.1%. The invention is however not limited to the use of essentially low sulphur containing hydroxide sludge. Hydroxide sludge containing amounts of sulphur, suitably less than 15%, e.g. in the form of calcium sulphates, can also be used, as demonstrated in the full scale tests. Such contents occur in hydroxide sludge from production in an annealing and pickling line containing both a neolyte pickling section and a mixed acid section and in hydroxide sludge existing in landfills of today. Given the experiments performed hitherto, it seems that sulphur does not significantly affect the steel production process, but a higher content >15% of calcium sulphates seem to result in a somewhat increased content of sulphur in the steel and the slag. The main part of the sulphur leaves together with the effluent gases, as SO 2 .
The major part of the hydroxide sludge produced in a neutralisation plant of the applicant originates from pickling liquids from the acid retardation plant, SAR, from spent pickling baths, and from neutralised flushing water from the pickling baths. A minor amount, about 5-10%, originates from a chromium reduced electrolyte from a neolyte pickling step, which is a pre-pickling method especially designed for cold-rolled surfaces before pickling with mixed acid. The neolyte pickling step contains sodium sulphate (Na 2 SO 4 ) as an electrolyte. In this neutralisation plant the filtering of hydroxide sludge is however performed in seasons, why it is possible to obtain a hydroxide sludge having low sulphur content. In the other neutralisation plants of the applicant, all pickling liquids are mixed before they are led to the neutralisation plant, which results in a higher sulphur content in the produced hydroxide sludge.
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A method of producing a fluxing agent that can be used in production of steel, preferably stainless steel, employs as a raw material a hydroxide sludge that results from neutralization of metal-contaminated pickling liquid from a pickling step for a steel and contains at least one fluoride-containing compound. The hydroxide sludge is calcined. Steel, preferably stainless steel, is produced by decarburizing a steel heat, whereby a slag is formed on top of the steel heat, and adding a fluxing agent to the slag.
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BACKGROUND OF THE INVENTION
The present invention relates to a mechanism for automatic inking at predetermined points on a paperboard printing machine.
For a traditional paperboard press, ink is applied to the rollers of the press by an operator using an ink brush. Since the rollers rotate at high speed, the operator has to stand beside the rollers when applying ink to the rollers. Accidents frequently happen when an ink brush or even the hand of operator is unexpectedly clamped by the rotating rollers. Apart from the accidents, disadvantages from manual inking based on visual judgement, such as variable amount of ink applied, unevenly and untimely applied ink, error in inking positions, missed application of ink, etc. might very possibly cause the resulted printing on the paperboard to be smudgy, unclear, poor effect, etc.
Articles to be printed on a paperboard press are usually unfolded paperboard used to making cartons. The paperboard (which is generally the so-called corrugated board) is usually printed with what we commonly refer to as shipping marks. The marks can be further classified into a master mark which is larger in size and is shown on the front side of a carton for showing the description of the article contained therein or trademark thereof, and a side mark which is smaller in size and is shown on side and/or bottom faces of a carton for showing address and/or phone number of the consignee, or other descriptive letterings. Usually, amount of ink used relates to the size of printed marks or letters. For the master marks in which larger letters are used, ink of higher consistency and richer amount is required, and, for the side marks, less ink is required.
To eliminate the drawbacks existed in the traditional manual-inking press, automatic inking printing machines are developed. However, such conventional automatic inking printing machines would usually cause additional loss or consumption of ink because the entire surface of the roller must be applied with ink; besides, amount of ink applied to print the paperboard is the same for every part of the board, that is, the ink consistency for printing master marks and for side marks is the same, and therefore, not every marks or letters may have desired degree of clearness, that is, smaller letters would be smudged if the larger letters got the desired clearness, and reversely, the larger letters might be too light if the smaller letters got the desired clearness.
In view of these disadvantages, it is necessary to have another improved automatic inking mechanism which may evenly supply adequate amount of ink to the roller to meet different ink consistency required by printed marks or letters in different sizes lest ink should be unnecessarily wasted.
SUMMARY OF THE INVENTION
The automatic inking mechanism according to the present invention is installed at a proper position above the top roller of a common paperboard printing machine. The machanism mainly consists of a framework which is reciprocatively movable on a pair of rails when driven by a motor, an ink reservoir which may be driven by an actuated cylinder connected to bottom of the framework to shift up and down above the roller, and an induction member provided on the framework which may sequentially induce a plurality of inducers separately disposed at adequate positions along one of the rails on which the framework reciprocates. When the framework moves, the induced inducers causes the cylinder to to actuate the ink reservoir to supply ink to the top roller of the printing machine at preset points.
When the present invention is properly installed on a traditional paperboard printing machine above the top roller, ink may be economically saved through the automatic inking at preset points while better printing quality may be achieved through ink applied with even consistency and clear printed marks or letters.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a three-dimensional perspective showing a paperboard printing machine installed with the present invention;
FIG. 2 is a three-dimensional perspective showing the cylinder and the ink reservoir used in the present invention;
FIG. 3 is a front elevational view showing the cylinder and the ink reservoir in FIG. 2 above the top roller of the paperboard printing machine; and
FIG. 4 shows an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Please refer to FIG. 1 in which the referential number of A is designated to the uppermost roller of a common paperboard printing machine. A common paperboard printing machine has a group of cylinders or rollers arranged from top to bottom. When the uppermost roller A is applied with ink, ink thereon shall be passed to the bottom roller through the frictional transmission by the intermediate rollers. The purpose of the present invention is to timely supply adequate amount of ink at preset points on the uppermost roller A of the common paperboard printing machine.
To install the present invention on a paperboard printing machine, a pair of supporting frames 12 are mounted on top of the printing machine at adequate positions near two ends thereof to support two rack rails 11 parallelly extending across the printing machine such that they are generally located above the roller A. A framework 21 is disposed on the pair of rack rails 11 and is reciprocatively movable thereon by means of four gears 22 provided at four corners of the framework 21 engageable with the rack rails 11 when the framework 21 is driven to move by a motor 23. A transmission belt 24 is used to connect a first belt wheel 25 of the motor 23 and a second belt wheel 27 provided on a bottom shaft of the framework 21 so that the motor 23 can drive the framework 21 to move. An induction member 28 is provided on front edge of the framework 21 at a proper position. A plurality of inducers 13 are adjustably disposed along one of the rack rails 11 adjacent to the induction member 28. Below the framework 21, a panel 29 is connected thereto and a cylinder 31 (as shown in FIG. 2) is fixed on the panel 29 at a proper position. When the induction between the induction member 28 and the inducers 13, the motor 23 and the cylinder 31 are actuated.
Please refer to FIG. 2, the cylinder 31 is vertically fixed to the panel 29 and has a downward extended pushrod 32 to bottom end of which an L-shaped plate 33 is fixedly connected. An ink reservoir 41 is screwed to the L-shaped plate 33 with fixing screws 34. Ink as required may be contained in the ink reservoir 41. The ink reservoir 41 has a generally V-shaped bottom portion with a slit 44 extending full length of the ink reservoir 41. An embossed roller 42 is disposed in the ink reservoir 41 such that it lies on the slit 44 with its two ends separately extending out of two ends of the ink reservoir 41 and connected to the ink reservoir 41 by bolts 43. The bolts 43 also serve as adjusting screws to adjust gap between the embossed roller 42 and the slit 44. Please refer to FIG. 3, the ink reservoir 41 may move up and down through the reciprocation of the pushrod 32 of the cylinder 31 in vertical direction. When the ink reservoir 41 is at a down position, the embossed roller 42 is allowed to adequately contact the uppermost roller A of the paperboard printing machine. When the roller A rotates, the embossed roller 42 is frictionally driven to rotate. The embossed surface of roller 42 in rotation shall cause the ink in the ink reservoir 41 to be applied to the roller A more evenly than by manual inking.
To operate the present invention, first adjust the inducers 13 so that their positions correspond to where a shipping mark, for example, is to be printed on a paperboard. The initial induction position is where the framework 21 stops at the left end of the rack rails 11, at where the induction member 28 induces the first inducer 13. The framework 21 is then caused to move rightward until the induction member 28 induces the second inducer 13, i.e. the inducer at where the shipping mark is to be printed (as shown in FIG. 4). At this point, the framework 21 stops moving and the pushrod 32 of the cylinder 31 is actuated to move downward, causing the ink reservoir 41 to move down, too, allowing the embossed roller 42 to contact and press against the roller A. The rotation of roller A causes the embossed roller 42 to rotate, the rotating embossed roller 42 in turn evenly passes ink in the ink reservoir 41 to the roller A, and then to the other rollers for printing. A time switch in a control switch box B located adjacent to one end of the roller A may be set to control the duration for which the cylinder 31 is moving downward. Since the time switch is a known art, it is not particularly described herein. To speak more specifically, the amount of ink applied to the roller A at a certain location is controlled by the time for which the embossed roller 42 contacts with the roller A. When the application of ink is completed by allowing the embossed roller 42 in the ink reservoir 41 to fully contact the roller A for the preset period of time, the cylinder 31 actuates the pushrod 32 to move upward and the framework 21 shall move rightward to the third, fourth inducers 13, etc. one after another, repeating the same movement as described above. The induction at each position to be printed and the time for which the embossed roller 42 contacts with the roller A are preset based on the size of the letters and the desired ink consistency. When the printing on a paperboard is completed, the framework 21 with the induction member 28 moves to and induces the last inducer 13, the motor 23 runs in reverse direction, causing the framework 21 to move leftward. When the framework 21 moves leftward, the application of ink to the roller A may or may not be actuated depending on actual need. When the framework 21 returns to the most left or the first inducer 13, the previously described movement may be repeated to print another paperboard.
According to the above description, the amount and position of the inducers 13 may be adequately adjusted depending on the size of paperboard and the location to be printed to save a lot of time for printing and ink to use. Since the amount of ink applied may be controlled through the duration the embossed roller contacting with the roller A, different but adequate consistency of ink for letters or marks at different printing positions may be desirably controlled and thereby gives better printing effect.
The printing ink is a kind of viscous fluid in a semi-solid state, it would not leak from the slit 44 at bottom of the ink reservoir 41 even when the embossed roller 42 is not in rotating, so long as the slit 44 is not more than 0.20 mm in width. Moreover, the bolts 43 screwing the embossed roller 42 to the ink reservoir 41 are usually adjusted to allow the gap between the embossed roller 42 and the slit 44 suitable for normal printing requirements. However, the gap between the embossed roller 42 and the slit 44 may be enlarged by means of adjusting bolts 43 to allow more ink to be passed to the roller A for printing patterns to be fully printed. In the event ink of different color is required, just loose the fixing screws 34 fastening the ink reservoir 41 to the L- shaped plate 33, and replace it with another ink reservoir 41 containing ink of desired color.
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The present invention relates to an automatic inking mechanism used on a common paperboard printing machine, it mainly comprises a framework reciprocatively movable on a pair of rack rails. Induction means disposed on the framework actuates a cylinder attached to the framework to move up and down an ink reservoir from which adequate amount of ink can be automatically applied to rollers of the printing machine for printing patterns at preset positions on a paperboard with even ink consistency and clear printed letters or patterns. Both the quality and efficiency of printing are largely improved.
| 1
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CLAIM TO PRIORITY
[0001] This application claims priority of our co-pending U.S. provisional patent application entitled “A Magnetic Radiator arranged with Decoupling Means”, filed on Nov. 28, 2007 and assigned Ser. No. 61/004,600; and which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to portal article detection means.
[0004] 2. Description of the Prior Art
[0005] Portal article detection means are known per se. For example, they are contemporary used in many department stores and usually comprise multiple magnetic radiators arranged in each other's vicinity, for example multiple exit ports. The magnetic radiator may be composed of a suitable plurality of radiator elements, which may be used to provide a single detection port bar, wherein said radiator elements are arranged consecutively, for example in a vertical order. The radiator elements generate respective magnetic fields. A magnetic field generated by a first radiator element will induce voltage in other radiator elements positioned in its vicinity. This means phase of the other radiator elements will be influenced in such a way that, for example, the phase will be equal and/or opposite to the phase of the first radiator element. Preferably, the phase of the radiator element is defined by the radiator elements source.
[0006] Also, the amplitude will be influenced in such a way that, for example, the amplitude will increase and/or decrease compared to the desired value defined by the radiator elements source.
[0007] However, it may be desirable to control radiator elements separately, for example to alter phase and the amplitude of one radiator element without altering radiation parameters of the other radiator elements.
[0008] It is a disadvantage of the known radiator elements that mutual coupling of radiator elements constituting a magnetic radiator of a portal article detection means can make it impossible to control the radiator elements separately. More particularly, if the magnetic radiators are in resonance on a certain frequency, the mutual coupling may alter the resonance frequency into multiple resonant frequencies, which is undesirable. This is undesirable because it is important to control each radiator element separately, in such a way that radiator elements positioned in each other's vicinity have a minimal influence on an individual resonance frequency of each radiator element constituting the magnetic radiator.
SUMMARY OF THE INVENTION
[0009] It is an object of the invention to provide a portal article detection means comprising a plurality of radiator element circuits, wherein said plurality of radiator elements may be individually controlled.
[0010] To this end, the portal article detection means according to the invention comprises an electronic component arranged in electrical connection between said radiator element circuits for substantially decoupling the radiator elements in the same frequency range.
[0011] The technical measure of the invention is based on the following insights, which shall be explained with respect to an equivalent circuit of a magnetic radiator circuit comprising three radiator elements implemented as three inductors L 1 , L 2 , L 3 .
[0012] It will be appreciated that the inventive insight are applicable to any number of inductors. If the coupling factor between two certain radiator elements is negative, the equivalent inductance L ij will have a negative value too. A similar effect can be created by altering the polarity of the radiator elements. If one of the elements has an inverted polarity, the coupling factors to this particular element will be inverted as well. By suitably decoupling the equivalent inductors L 11 , L 22 and L 33 using electronic components the undesirable effects of coupling are substantially reduced and the three inductors can be used independently in the electrical circuit of the magnetic radiator.
[0013] Preferably, the electronic component is selected to decouple the radiator elements on the resonant frequency of the radiator. More preferably, the electronic component is selected to decouple the radiator elements over a broad frequency band containing the resonant frequency of the radiator. Depending on the used component, the decoupling circuit may be resonant on a certain frequency, range of frequencies or not resonant at all. In case of a decoupling circuit containing mainly inductive components a non resonant decoupling circuit will be realized. In case of a decoupling circuit containing mainly capacitive components, a resonant decoupling circuit will be realized. The decoupling circuit may also contain a combination of capacitive and inductive components, either in series or parallel or a combination of both to obtain the desired decoupling impedance.
[0014] This may be implemented by using a tuneable electronic component which may be tuned in operation for compensating either any drift of the working frequency or a purposeful alteration of the working frequency. This has an advantage that the decoupling can be controlled in a broad band of useful frequencies. Preferably, the radiator elements and the electronic component are arranged on a common printed circuit. This has an advantage of increased durability of the circuit.
[0015] In case when the electronic component is arranged tuneable, the printed circuit may comprise suitable control unit and microprocessor for enabling alteration of decoupling as a function of selected frequency in use. Examples of tuneable circuits are mechanically trimmed capacitors and inductors, varicaps or multiple capacitive and/or inductive components with switching elements to alter the total impedance of the decoupling circuit.
[0016] These and other aspects of the invention will be further discussed with reference to drawings, wherein like reference signs represent like items.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 presents in a schematic way coupling effects arising in a magnetic radiator comprising circuits of radiator elements.
[0018] FIG. 2 presents in a schematic way an equivalent electrical circuit for a magnetic radiator comprising three radiator element circuits.
[0019] FIG. 3 presents in a schematic way respective equivalent electrical circuits for magnetic radiators comprising three and four radiator element circuits.
[0020] FIG. 4 presents the circuits of FIG. 3 , wherein electronic component is arranged for decoupling only adjacent radiator elements.
DETAILED DESCRIPTION
[0021] FIG. 1 presents in a schematic way coupling effects arising in a magnetic radiator comprising radiator element circuits. For the sake of simplicity a magnetic radiator having three radiator element circuits is shown. It will be appreciated that the radiator element circuits may be arranged within the magnetic radiator so that either a negative or a positive coupling between the radiator element circuits occurs. Elements 1 , 2 , 3 represent a setup wherein respective radiator element circuits are negatively coupled, i.e. coupling factors k 12 , k 23 , k 13 are negative, due to the fact that magnetic fields B 12 , B 23 , B 13 are counter-aligned. The elements 1 ′, 2 ′, 3 ′, are arranged in such a way that individual magnetic fields (not shown) align resulting in a co-aligned net magnetic field B. In this case the coupling factors k 12 , k 3 , k 13 (not indicated) are positive.
[0022] It is understood, that if the coupling factor between two certain elements is negative, the equivalent inductance L ij will have a negative value too. To decouple the radiator elements, the inductors L ij , must be made infinitively large which can be done by adding impedance Z ij in parallel to L ij . Z ij //jωL ij =∞ can only be realized when Z ij =−jωL ij . In particular case where the coupling factor k ij is negative, the value of L ij is negative, a suitable value of Z ij can thus be realized by adding an electronic component, for example a positive inductor coil equal to |L ij |. If L ij is positive, the same decoupling effect can be realized by adding a capacitor in parallel to this virtual equivalent inductance. Any component with a given complex impedance can be used as long as Z=−Z ij at the frequency of interest.
[0023] It is further understood that in practice, for small values of k ij , the values of the inductors L 11 , L 22 and L 33 are equal or close to L 1 , L 2 and L 3 . Three inductors can be placed between the ports of the radiator elements L 1 , L 2 and L 3 thereby effectively decoupling radiator elements of the magnetic radiator by compensating mutual coupling only between adjacent radiator elements. It shall be appreciated that the same approach is applicable for any number of radiator elements constituting a magnetic radiator.
[0024] FIG. 2 presents in a schematic way an equivalent electrical circuit 20 for a magnetic radiator comprising three radiator element circuits. The equivalent circuit of a magnetic radiator with multi elements can be seen as an N-port transformer T with a certain coupling factor. If 3 magnetic radiators are used, the equivalent electrical circuit of this transformer with coupling factors k 12 , k 13 and k 23 is as shown in FIG. 2 , item 22 . The corresponding values of the equivalent inductances L ij and L ii are given by:
[0000]
L
ij
=
(
1
-
k
ij
2
k
ij
)
·
L
i
L
j
[0025] L ii ≈L i for small values of k 12 , and k 13 , or
[0000]
L
ii
=
1
-
k
itot
2
L
i
-
1
-
k
itot
·
L
i
-
0.5
·
L
itot
-
0.5
,
where
[0026] L itot =(L i+1 ·L i+2 · . . . ·L n ) 1/n−1 is total opposite inductance facing L i ;
[0027] k itot =1−[(1−k ij )·(1−k ik )· . . . ·(1−k ii+n−1 )] represent total coupling factors involving L i .
[0028] When the equivalent circuit of the radiator has been defined, a solution for the decoupling problem can be found in the definition of the inductors L 12 , L 13 and L 23 . For compensating for the decoupling inductances real electric components, like inductances or capacitances can be used, as is described with reference to FIG. 1 . In this way the coupling factors k ij , which can be either negative or positive depending on the structure of the magnetic radiator, are compensated. Preferably, such compensation is performed only for adjacent radiator element circuits constituting the magnetic radiator.
[0029] FIG. 3 presents in a schematic view 30 of respective equivalent electrical circuits 31 , 32 for magnetic radiators comprising three and four radiator element circuits, respectively. In the equivalent electric circuit 31 , mutual coupling between radiator elements is illustrated by electric components −L 12 , −L 23 , −L 13 . As have been explained earlier, equivalent negative inductances may be compensated by using a positive inductive element in the real electrical circuit. In case when the equivalent inductance is positive, it can be compensated by providing a real capacitive element connected in parallel to corresponding portions of the equivalent circuit. In these ways coupling effects are minimized. In the equivalent circuit 32 , representing a configuration where four radiator elements are used the following equivalent electronic components (negative inductances) are shown: −L 12 , −L 23 , −L 34 , −L 13 , −L 24 , −L 14 . It will be appreciated that in depicted exemplary embodiments the electronic component necessary to compensate for effects caused by the equivalent electronic components comprised a set of sub-components L 12 , L 23 , L 13 or L 12 , L 23 , L 34 , L 13 , L 24 , L 14 for effectively decoupling radiator elements constituting a suitable magnetic radiator.
[0030] FIG. 4 presents a schematic view 40 of the circuits of FIG. 3 , wherein electronic component is arranged for decoupling only adjacent radiator element circuits. Also in this exemplary embodiment the electronic component comprises sub-components −L 12 , −L 23 or −L 12 , −L 23 , −L 34 . The present embodiment is based on the insight that a coupling factor between adjacent radiator elements are substantially larger that the coupling factors between non-adjacent radiator elements. For this reason it is found to be sufficient to substantially mitigate coupling effects in a magnetic resonator comprising a plurality of radiator elements circuits by placing a suitable decoupling electronic component only between adjacent radiator element circuits. Again, equivalent negative inductances may be compensated by using a positive inductive element in the real electrical circuit. In case when the equivalent inductance is positive, it can be compensated by providing a real capacitive element connected in parallel to corresponding portions of the equivalent circuit. In these ways coupling effects are minimized.
[0031] While specific embodiments have been described above, it will be appreciated that the invention may be practiced otherwise than as described. The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described in the foregoing without departing from the scope of the claims set out below.
|
A portal article detection means ( 10, 20 ) having a plurality of radiator elements ( 1, 2, 3 , L 1 , L 2 , L 3 ) for generating a magnetic field (B), wherein the magnetic radiator further comprises an electronic component (−L 12 , −L 23 , −L 13 ) arranged in electrical connection between said radiator elements for substantially decoupling the radiator elements (L 1 , L 2 , L 3 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a paper feeder for storing recording media and an image forming apparatus having the paper feeder, and particularly relates to a paper feeder capable of locking each paper feed cassette to prevent recording media stored in the paper feed cassette from being taken out freely from the paper feed cassette, and an image forming apparatus having the paper feeder.
2. Background Art
Paper feed cassettes of an image forming apparatus such as a printer are generally filled with sheets of plain paper. Occasionally, however, by use of mica toner containing magnetic powder or the like, numeric characters may be printed on securities such as checks charged into a paper feed cassette. The checks or the like subjected to printing thus can be used immediately for economic transactions. From such convenience, printers have been increasingly used for such applications in recent years.
When a printer is used for such applications, it is necessary to protect the securities in the paper feed cassette from theft. In order to prevent theft, therefore, in the background art, a locking unit or the like is provided for preventing recording media in a paper feed cassette from being taken out freely when printing is performed on securities (see JP-A-2001-121795, page 3, FIG. 1).
SUMMARY OF THE INVENTION
In the aforementioned document, the case for only one paper feed cassette is taken into consideration, but the case for a plurality of paper feed cassettes is not taken into consideration. When a plurality of paper feed cassettes are provided in the technique disclosed in the aforementioned document, a plurality of locking units must be provided for the paper feed cassettes respectively, and a user must lock the paper feed cassettes individually. Such an operation is troublesome for the user and also disadvantageous in terms of cost. With the number of paper feed cassettes increasing, the technique is more disadvantageous in terms of workability or cost.
A paper feeder capable of locking a plurality of paper feed cassettes in an easy operation, and an image forming apparatus having the paper feeder is disclosed herein.
According to an aspect of the invention, a paper feeder includes: a first paper feed cassette in which to store a recording medium with a lock state that is selected from an unlocked state where the recording medium can be taken out therefrom and a locked state where the recording medium cannot be taken out therefrom; a locking portion that determines whether to bring the lock state of the first paper feed cassette into the unlocked state or the locked state; a second paper feed cassette in which to store a recording medium, capable of selectively entering an unlocked state where the recording medium can be taken out therefrom and a locked state where the recording medium cannot be taken out therefrom; and a lock state transmitting portion that transmits the lock state of the first paper feed cassette to the second paper feed cassette to bring the second paper feed cassette into the unlocked state or the locked state in accordance with the lock state of the first paper feed cassette.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be more readily described with reference to the accompanying drawings:
FIG. 1 is a front perspective view showing a laser printer according to a first embodiment of the invention, with an explanatory side view of a gang lock unit provided in the laser printer.
FIG. 2 is a schematic perspective view showing a printer body in the laser printer in FIG. 1 .
FIG. 3 is a sectional view taken on line III-III in FIG. 2 .
FIG. 4 is a front perspective view showing a laser printer according to a second embodiment of the invention, with an explanatory side view of a gang lock unit provided in the laser printer.
FIG. 5A is a schematic perspective view showing a printer fixing bar provided in a support base for supporting the laser printer according to the first embodiment of the invention.
FIG. 5B is a schematic perspective view showing a printer fixing bar provided in a support base for supporting the laser printer according to the second embodiment of the invention.
FIG. 6 is a front perspective view showing a laser printer according to another embodiment of the invention, with an explanatory side view of a gang lock unit provided in the laser printer.
FIG. 7 is a front perspective view showing a laser printer according to another embodiment of the invention, with an explanatory side view of a gang lock unit provided in the laser printer.
FIG. 8 is a front perspective view showing a laser printer according to another embodiment of the invention, with an explanatory side view of a gang lock unit provided in the laser printer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will be described below with reference to the drawings.
FIG. 1 is a front perspective view showing a laser printer according to a first embodiment of the invention, with an explanatory side view of a gang lock unit provided in the laser printer. The laser printer 1 is constituted by a printer body 1 a and a stack of three paper feed cassette units 1 b , 1 c and 1 d disposed under the printer body 1 a . The paper feed cassette units 1 b , 1 c and 1 d are separate from the printer body 1 a and have the same configuration as one another. Each paper feed cassette unit 1 b , 1 c , 1 d can be removably attached to the printer body 1 a . A user can remove the paper feed cassette unit desirably or install another paper feed cassette unit having the same configuration additionally. More in particular, the printer body 1 a and the paper feed cassette units have foot portions in their bottom surface respectively (only foot portions 61 of the lowest paper feed cassette unit 1 d are shown in FIG. 1 ). The printer body 1 a and the paper feed cassette units are disposed in a stack without any misalignment due to the foot portions 61 engaging with lower units respectively.
Here, each member is denoted by a reference numeral with a suffix “a”, “b”, “c” or “d” showing which one of the printer body 1 a and the paper feed cassette units 1 b , 1 c , 1 d the member belongs to.
A paper feed cassette 6 a storing securities such as checks as recording media is provided in the printer body 1 a removably in a direction perpendicular to the paper of FIG. 1 . Similarly in each paper feed cassette unit 1 b , 1 c , 1 d , a paper feed cassette 6 b , 6 c , 6 d is provided removably in a unit body 60 b , 60 c , 60 d . Incidentally, a recess portion 16 a , 16 b , 16 c , 16 d for making the user easier to put his/her fingers therein when he or she pulls out each paper feed cassette 6 a , 6 b , 6 c , 6 d is formed at the front of the paper feed cassette 6 a , 6 b , 6 c , 6 d.
A gang lock unit is provided on the front left side of each paper feed cassette 6 a , 6 b , 6 c , 6 d . The gang lock unit performs gang locking as follows. That is, as soon as the paper feed cassette 6 a provided in the printer body 1 a is brought into a locked state, the gang lock unit automatically brings the paper feed cassettes 6 b , 6 c and 6 d of the paper feed cassette units 1 b , 1 c and 1 d stacked under the printer body 1 a , into the locked state.
Incidentally, the locked state means a state where the paper feed cassette 6 a , 6 b , 6 c , 6 d is prohibited from being pulled out, so that checks 3 in the paper feed cassette 6 a , 6 b , 6 c , 6 d cannot be taken out. An unlocked state means a state where the paper feed cassette 6 a , 6 b , 6 c , 6 d is allowed to be pulled out so that the checks 3 can be taken out.
A tag 14 is exposed to the apparatus front on the left side of the paper feed cassette 6 a of the printer body 1 a (see FIG. 2 ), while a lock gear 51 a , a cylinder 54 a fixed to the back side of the lock gear 51 a , and so on, are stored in the apparatus. That is, all the members of the gang lock unit but the tag 14 provided on the left side of the paper feed cassette 6 a of the printer body 1 a are stored in each unit but invisibly from the front surface. However, in order to make the description easier, those members are shown by the solid lines in the front view on the right side of FIG. 1 , and shown schematically in the explanatory view on the left side of FIG. 1 .
A key hole 14 a to which a key 90 can be inserted is formed in the tag 14 . The key hole 14 a is formed continuously in the lock gear 51 a and the cylinder 54 a in the printer body 1 a which will be described later. That is, the front end of the key 90 is designed to penetrate the tag 14 and the lock gear 51 a and reach the inside of the cylinder 54 a.
Lock gears 51 a , 51 b , 51 c and 51 d are provided correspondingly to the paper feed cassette 6 a of the printer body 1 a and the paper feed cassettes 6 b , 6 c and 6 d of the paper feed cassette units 1 b , 1 c and 1 d respectively. Each lock gear 51 a , 51 b , 51 c , 51 d is a circular plate-like member having a gearing groove formed in its circumferential edge. A columnar cylinder 54 a , 54 b , 54 c , 54 d is fixed to the back side of the lock gear 51 a , 51 b , 51 c , 51 d.
A hook 53 a , 53 b , 53 c , 53 d and a locking bar 52 a , 52 b , 52 c , 52 d are fixed to the circumferential surface of the cylinder 54 a , 54 b , 54 c , 54 d in turn in order of increasing distance from the tag 14 . Accordingly, the cylinder 54 a , 54 b , 54 c , 54 d rotates with the rotation of the lock gear 51 a , 51 b , 51 c , 51 d in the locking operation, so that the hook 53 a , 53 b , 53 c , 53 d and the locking bar 52 a , 52 b , 52 c , 52 d fixed to the cylinder 54 a , 54 b , 54 c , 54 d also rotate together.
Each locking bar 52 a , 52 b , 52 c , 52 d is a bar-like member which is received in a recess portion 55 a , 55 b , 55 c , 55 d provided in the locking-portion-side side surface of the paper feed cassette 6 a , 6 b , 6 c , 6 d in the locked state. In FIG. 1 , the locking bars 52 a , 52 b , 52 c and 52 d in the locked state are shown by the solid lines and in the unlocked state are shown by the broken lines.
A grappling portion is formed at the tip of each hook 53 a , 53 b , 53 c , 53 d . The hooks 53 a , 53 b and 53 c except for the lowest hook 53 d engage with hook destinations 80 b , 80 c and 80 d provided to project on the top of the unit bodies 60 b , 60 c and 60 d in the paper feed cassette units 1 b , 1 c and 1 d , respectively. Each hook destination 80 b , 80 c , 80 d is a bar extending perpendicularly to the paper of FIG. 1 . The hook destination 80 b , 80 c , 80 d is attached to be put between two vertical members (not shown) attached to the top of the paper feed cassette unit 1 b , 1 c , 1 d . Thus, the hook destination 80 b , 80 c , 80 d is disposed to project on the top of the unit body 60 b , 60 c , 60 d.
On the other hand, the hook 53 d provided for the paper feed cassette 6 d closest to a support base 200 supporting the apparatus engages with a printer fixing bar 201 provided in the support base 200 . The printer fixing bar 201 is a U-shaped member, which is attached to project from the surface of the support table 200 as shown in FIG. 5A . The support base 200 provided with the printer fixing bar 201 thus is sold, particularly as a support of the laser printer 1 according to this embodiment, in set with the laser printer 1 .
Incidentally, in the same manner as the locking bars 52 a , 52 b , 52 c and 52 d , in FIG. 1 , the hooks 53 a , 53 b , 53 c and 53 d in the hooked state are also shown by the solid lines and in the unhooked state are also shown by the broken lines.
The lock gears 51 a and 51 b are connected to each other through three transmission gears 70 a , 71 b and 72 b disposed between the lock gears 51 a and 51 b . The lock gears 51 b and 51 c are connected to each other through three transmission gears 70 b , 71 c and 72 c disposed between the lock gears 51 b and 51 c . The lock gears 51 c and 51 d are connected to each other through three transmission gears 70 c , 71 d and 72 d disposed between the lock gears 51 c and 51 d.
Accordingly, when the key 90 is inserted into the key hole 14 a of the tag 14 provided in the printer body 1 a and the key 90 is rotated in the illustrated arrow direction (clockwise), the lock gear 51 a rotate in the arrow direction together with the tag 14 . This rotation is transmitted to the lock gears 51 b , 51 c and 51 d in the lower paper feed cassettes 6 b , 6 c and 6 d through the transmission gears 70 a , 71 b , 72 b , 70 b , 71 c , 72 c , 70 c , 71 d and 72 d . In such a manner, all the gears rotate in the arrow direction in FIG. 1 substantially concurrently.
Incidentally, in this embodiment, the printer body 1 a has one lock gear and one transmission gear, and each paper feed cassette unit 1 b , 1 c , 1 d has one lock gear and three transmission gears. The lowest transmission gear 70 d provided in the paper feed cassette unit 1 d disposed undermost does not serve to transmit the gear rotation. For example, when another paper feed cassette unit is further stacked under the paper feed cassette unit 1 d , the transmission gear 70 d will serve as a transmission gear.
With the rotations of the plurality of gears, the locking bars 52 a , 52 b , 52 c and 52 d and the hooks 53 a , 53 b , 53 c and 53 d fixed to the cylinders 54 a , 54 b , 54 c and 54 d respectively also rotate in the arrow direction in FIG. 1 , respectively. As soon as the key 90 rotates to reach the position of the locked state, the locking bars 52 a , 52 b , 52 c and 52 d are received in the recess portions 55 a , 55 b , 55 c and 55 d of the paper feed cassettes 6 a , 6 b , 6 c and 6 d , while the hooks 53 a , 53 b , 53 c and 53 d move in the unit stack direction, that is, downward so as to engage with the hook destinations 80 b , 80 c and 80 d and the printer fixing bar 201 fixed onto the support base 200 , respectively.
Incidentally, the locking bars 52 a , 52 b , 52 c and 52 d are removable. For example, therefore, when only the locking bar 52 b is removed, only the paper feed cassette 6 b in the paper feed cassette unit 1 b will avoid gang locking and keep its unlocked state even if the other three paper feed cassettes 6 a , 6 c and 6 d are brought into the locked state.
The locking gears 51 a , 51 b , 51 c and 51 d , the locking bars 52 a , 52 b , 52 c and 52 d , the hooks 53 a , 53 b , 53 c and 53 d and the transmission gears 70 a , 71 b , 72 b , 70 b , 71 c , 72 c , 70 c , 71 d , 72 d and 70 d constituting the gang lock units are stored in the printer body 1 a and the paper feed cassette units 1 b , 1 c and 1 d respectively, and prevented from projecting outside the apparatus even when the paper feed cassettes 6 a , 6 b , 6 c and 6 d are in the locked state.
Next, the printer body 1 a of the laser printer 1 will be described in detail with reference to FIGS. 1 to 3 . FIG. 2 is a schematic perspective view showing the printer body 1 a in the laser printer 1 in FIG. 1 . FIG. 3 is a sectional view taken on line III-III in FIG. 2 .
As shown in FIGS. 1 and 2 , a manual paper feed tray 13 is installed openably and closably above the paper feed cassette 6 a of the printer body 1 a . An operating portion 15 is provided in a surface formed further above the manual paper feed tray 13 and obliquely from the side surface of the printer to the top thereof as shown in FIG. 2 . The operating portion 15 is provided with a liquid crystal display 15 a and a plurality of buttons 15 b . Settings in the laser printer 1 are shown in the liquid crystal display 15 a . When the user pushes the buttons 15 b , the user can do various settings on the laser printers 1 .
The check 3 fed from the paper feed cassette 6 a or the manual paper feed tray 13 in the printer body 1 a is subjected to print processing through the process in which the check 3 is carried along a feed path inside the printer body 1 a as will be described later. Then, the check 3 is delivered onto a paper outlet tray 36 by the rotations of a paper delivery roller pair 35 shown in FIGS. 2 and 3 .
Here, the internal configuration of the printer body 1 a will be described with reference to FIG. 3 . First, a pressure plate 8 , a paper feed roller 9 and a separation pad unit 10 are provided inside the paper feed cassette 6 a mounted in the lower portion of the printer body 1 a . The paper feed roller 9 is provided above a one-end-side end portion of the paper feed cassette 6 a . The paper feed roller 9 rotates intermittently.
The pressure plate 8 has a top on which the checks 3 can be laid, and a bottom urged upward by a spring 8 a . In addition, the pressure plate 8 is supported swingably at one end more distant from the paper feed roller 9 . Thus, the other end of the pressure plate 8 closer to the paper feed roller 9 is made movable in the up/down direction. The paper feed roller 9 and the separation pad unit 10 are disposed to face each other. A separation pad (not shown) made from a member having a high friction drag is pressed toward the paper feed roller 9 by a spring 10 b disposed on the back side of a pad backing 10 c in the separation pad unit 10 .
The check 3 fed from the paper feed cassette 6 a is fed to a feed roller pair 11 and a resist roller pair 12 through the paper feed roller 9 and the separation pad unit 10 along a feed path 7 shown by the chain line in FIG. 3 . The check 3 is corrected for skewing in the position of the resist roller pair 12 . The check 3 corrected for skewing is then sent to an image forming position P of the process unit 18 (a contact portion between a photoconductor drum 23 and a transfer roller 25 which will be described later, that is, a transfer position where a toner image on the photoconductor drum 23 is transferred to the check 3 ), and subjected to printing therein.
The process unit 18 is constituted by a drum cartridge, a developing cartridge 24 , and so on. The drum cartridge includes the photoconductor drum 23 , a Scorotron type charger 37 serving as a charging unit, the transfer roller 25 serving as a transfer unit, and so on. The developing cartridge 24 can be removably attached to the drum cartridge. The developing cartridge 24 has a toner storage portion 26 , a developing roller 27 serving as a developing unit, a layer thickness limiting blade (not shown), a toner feed roller 29 , etc. Incidentally, the toner storage portion 26 is filled with mica toner containing magnetic powder and suitable for the check 3 used as a recording medium as in this embodiment. A toner image carried on the surface of the photoconductor drum 23 is transferred to the check 3 when the check 3 passes between the photoconductor drum 23 and the transfer roller 25 .
In addition, a scanner unit 17 is disposed on the lower surface side of the paper outlet tray 36 . The scanner unit 17 has a laser beam emitting portion (not shown), a polygon mirror 20 to be driven to rotate, lenses 21 a and 21 b , a reflecting mirrors 22 , etc. Then, a laser beam emitted from the laser beam emitting portion in accordance with given image data is passed through or reflected on the polygon mirror 20 , the lens 21 a , the reflecting mirrors 22 and the lens 21 b in that order. Thus, the surface of the photoconductor drum 23 serving as a photoconductor in the process unit 18 is scanned and irradiated with the laser beam at a high speed.
A fixing unit 19 serving as fixing means to thermally fix the image on the check 3 is disposed on the downstream side of the process unit 18 along the feed path 7 . The fixing unit 19 has a heating roller 30 , a pressure roller 31 disposed to press the heating roller 30 , and a feed roller pair 32 provided on the downstream side of the rollers 30 and 31 . The heating roller 30 is made from metal such as aluminum, and provided with a heater such as a halogen lamp for heating so that the toner transferred onto the check 3 in the process unit 18 is fixed thermally when the check 3 passes between the heating roller 30 and the pressure roller 31 . After that, the check 3 is carried to the position of the paper delivery roller pair 35 by the feed roller pair 32 .
Incidentally, the laser printer 1 according to this embodiment can perform double-sided printing. However, the laser printer 1 is generally set for single-sided printing when the check 3 is used as a recording medium. In setting of single-sided printing, the check 3 carried to the delivery roller pair 35 after the single-sided printing is delivered onto the paper outlet tray 36 by the rotation of the paper delivery roller pair 35 .
On the other hand, for example, assume that setting is done for double-sided printing when a sheet of plain paper is used as a recording medium. In such a case, the front and back of the sheet of plain paper fed to the paper delivery roller pair 35 after single-sided printing are reversed due to the reverse rotation of the paper delivery roller pair 35 , and fed toward the resist roller pair 12 again along a reverse path 41 and a refeed path 40 a following the reverse path 41 . In the refeed path 40 a , the sheet of paper is carried while being held between a plurality of pairs of refeed rollers 43 a and 43 b disposed at a distance from one another, and fed to the resist roller pair 12 again through a refeed guide 45 . Then, the sheet of paper is subjected to printing on the other unprinted side thereof by the process unit 18 . The sheet of paper after the double-sided printing is delivered onto the paper outlet tray 36 due to the rotation of the paper delivery roller pair 35 as described above.
Incidentally, description has been made above on the case where the check 3 is fed from the paper feed cassette 6 a provided in the printer body 1 a . However, the check 3 can be selectively fed also from the paper feed cassette 6 b , 6 c , 6 d in the paper feed cassette unit 1 b , 1 c , 1 d shown in FIG. 1 , through a paper feed cassette unit feed path 46 (see FIG. 3 ). Incidentally, a mechanism or control for feeding recording media selectively from paper feed cassette units disposed in a stack are known well. Therefore, their detailed description will be omitted here.
As described above, the laser printer 1 according to the first embodiment has the four paper feed cassettes 6 a , 6 b , 6 c and 6 d so that various kinds of prints can be stored in the paper feed cassettes 6 a , 6 b , 6 c and 6 d severally. To bring the paper feed cassettes 6 b , 6 c and 6 d into the locked state, only the paper feed cassette 6 a having a locking portion is operated so that the other paper feed cassettes 6 b , 6 c and 6 d can be also brought into the locked state concurrently by gang locking. Such a configuration can reduce the cost in comparison with the case where a locking portion is provided for each of the four feed cassettes 6 a , 6 b , 6 c and 6 d . In addition, the locking operation becomes easy for the user because it will go well if locking is performed on only the paper feed cassette 6 a having the locking portion without any necessity of performing locking on the paper feed cassettes 6 a , 6 b , 6 c and 6 d individually.
When all the paper feed cassettes 6 a , 6 b , 6 c and 6 d are brought into the locked state by gang locking, paper feed cassettes used frequently or unnecessary to be protected from theft are also locked. This may be disadvantage for the user. Such disadvantageous can be solved in this embodiment. That is, the locking bars 52 a , 52 b , 52 c and 52 d are made removable. A locking bar corresponding to a paper feed cassette unnecessary to be locked is removed, and recording media unnecessary to be protected from theft are stored in the paper feed cassette.
In addition, an apparatus which can solve the disadvantage that a paper feed cassette used frequently or unnecessary to be protected from theft is locked can be realized by a comparatively simple configuration in which the locking bars 52 a , 52 b , 52 c and 52 d are made removable thus. In addition, the operation to remove the locking bars 52 a , 52 b , 52 c and 52 d is comparatively easy for the user.
In addition, in response to locking, the hook 53 d provided in the paper feed cassette 6 d closest to the support base 200 projects toward the support base 200 , and engages with the printer fixing bar 201 provided in the support base 200 . The laser printer 1 can be fixed to the support base 200 in concurrence with locking by such a comparatively simple configuration. The event that securities are carried away and stolen together with the laser printer 1 can be prevented easily and at a low price.
Although the three paper feed cassette units 1 b , 1 c and 1 d are used in this embodiment, a desired number of paper feed cassette units can be attached to the printer body 1 a . Thus, the options of the user can be broadened and the degree of freedom of the laser printer 1 is improved.
When gang locking is performed in response to locking, the printer body 1 a and the paper feed cassette units 1 b , 1 c and 1 d removably attached to the printer body 1 a are fixed to one other. It is therefore possible to prevent the event that securities are stolen together with each paper feed cassette unit 1 b , 1 c , 1 d removed from the printer body 1 a.
More in particular, in response to locking, the lock gears 51 a , 51 b and 51 c rotate so that the hooks 53 a , 53 b and 53 c move toward the paper feed cassette units 1 b , 1 c and 1 d , and engage with the hook destinations 80 b , 80 c and 80 d provided in the paper feed cassette units which are destinations of the hooks 53 a , 53 b and 53 c , respectively. Thus, the printer body 1 a and the paper feed cassette units 1 b , 1 c and 1 d disposed in a stack are fixed to one another. Accordingly, a desired number of paper feed cassette units can be installed so that the degree of freedom of the laser printer 1 is improved. In addition, the event that securities are stolen together with each paper feed cassette unit removed from the printer body 1 a can be prevented easily, at a low price and with a comparatively simple configuration.
In addition, the gang lock unit is constituted by a plurality of gears such as lock gears and transmission gears. Due to such a comparatively simple configuration, a laser printer which can lock a plurality of paper feed cassettes with an easy operation can be manufactured easily and at a low price.
Next, a laser printer according to a second embodiment of the invention will be described with reference to FIG. 4 . Here, parts similar in structure to those in the laser printer 1 according to the first embodiment are denoted by the same reference numerals correspondingly, and their description will be omitted. FIG. 4 is a front perspective view showing the laser printer according to the second embodiment of the invention, with an explanatory side view of a gang lock unit provided in the laser printer.
This embodiment is different from the first embodiment in the configuration of the gang lock unit. First, as shown in FIG. 4 , each hook 153 a , 153 b , 153 c , 153 d in this embodiment is received in its corresponding unit in the unhooked state as shown by the broken line in FIG. 4 , but it projects downward outside the unit in the hooked state as shown by the solid line.
Hook destinations 180 b , 180 c and 180 d and a printer fixing bar 202 are disposed in positions corresponding to the tips of the hooks in the locked state. In the first embodiment, each hook destination 80 b , 80 c , 80 d is disposed on the top of the unit body 60 b , 60 c , 60 d while the printer fixing bar 201 is attached to project from the surface of the support base 200 . In this embodiment, however, each hook destination 180 b , 180 c , 180 d is disposed inside a unit body 160 b , 160 c , 160 d without projecting from the unit body 160 b , 160 c , 160 d , while the printer fixing bar 202 is disposed inside a hole 200 x formed in the surface of the support base 200 as shown in FIG. 5B .
Each transmission gear is received in the printer body or each unit in the first embodiment. In this embodiment, however, each transmission gear projects outside the apparatus. That is, a transmission gear 170 a provided in a printer body 101 a projects downward from the bottom of the printer body 101 a , and lowest transmission gears 170 b , 170 c and 170 d provided in paper feed cassette units 101 b , 101 c and 101 d respectively project downward from the bottoms of the paper feed cassette units 101 b , 101 c and 101 d respectively. Incidentally, in spite of such a structure where the transmission gears project outside the apparatus, the lowest transmission gear 170 d is received in a hole 200 x formed in the surface of the exclusive support base 200 as shown in FIG. 4 when the paper feed cassette unit 101 d is mounted on the exclusive support base 200 . Thus, the laser printer 101 can be supported adequately on the support base 200 .
As described above, in the laser printer 101 according to the second embodiment, differently from the laser printer 1 according to the first embodiment, the printer fixing bar 202 does not project from the support base 200 . Accordingly, it is possible to avoid such a disadvantage that something is caught by the printer fixing bar 202 after the laser printer 101 has been moved.
However, in this embodiment in which the printer body 101 a and the paper feed cassette units 101 b , 101 c and 101 d are stacked vertically and supported on the support base 200 , they may be put on a support base which is not the exclusive support base 200 having the hole 200 x formed in the surface. In such a case, at the time of locking, there is a fear that the surface of the support base is injured by the tip of the hook 153 d provided in the lowest paper feed cassette unit 101 d , or the hook 153 d is damaged. On the other hand, in the first embodiment, the hook destinations 80 b , 80 c and 80 d are formed on the tops of the unit bodies 60 b , 60 c and 60 d of the paper feed cassette units 1 b , 1 c and 1 d respectively. It is therefore unnecessary to make the tips of the hooks 53 a , 53 b and 53 c project into the unit bodies 60 b , 60 c and 60 d of the adjacent paper feed cassette units 1 b , 1 c and 1 d respectively. Accordingly, even in the locked state, each hook 53 a , 53 b , 53 c is kept in the printer body 1 a or the unit body 60 b , 60 c , 60 d of the paper feed cassette unit 1 b , 1 c , 1 d provided therewith. It is therefore possible to solve the disadvantage that the support base is injured or the hook 153 d is damaged.
Although the preferred embodiments of the invention have been described above, the invention is not limited to the embodiments. Various changes in design can be made on the invention without departing from the claimed scope thereof.
For example, although the embodiments have been described on the case where a laser printer is adopted as an example of an image forming apparatus according to the invention, the invention is also applicable to various image forming apparatuses including other printers of an inkjet type and the like, copying machines, facsimile machines, and so on.
In addition, the toner storage portion 26 in the process unit 18 maybe filled with regular nonmagnetic toner. Although it is suitable to fill the toner storage portion 26 with mica toner containing magnetic powder when securities such as the checks 3 are used as recording media as in the embodiments, it may be filled with nonmagnetic toner when sheets of plain paper are used as recording media.
Although the unlocked/locked state of each paper feed cassette 6 a , 6 b , 6 c , 6 d is selected by use of a mechanical configuration, that is, a plurality of gears in the embodiments, for example, the unlocked/locked state may be selected by an electronic lock (power lock) or the like.
For example, FIG. 6 shows a configuration using a power lock. As shown in FIG. 6 , the printer body 1 a and the paper feed cassette units 1 b , 1 c and 1 d are provided with power lock portions 1101 a , 1101 b , 1101 c and 1101 d . The power lock portions 1101 a , 1101 b , 1101 c and 1101 d are connected through a bus 1102 to a controller 1103 that is provided in the printer body 1 a . The controller 1103 is configured to control a locked state and an unlocked state of each of the power lock portions 1101 a , 1101 b , 1101 c and 1101 d . When the key 90 is inserted into the power lock portion 1101 a and the key 90 is rotated in the illustrated arrow direction (clockwise), the power lock portion 1101 a brings the paper feed cassette 6 a into a locked state. Concurrently, the controller 1103 detects that the power lock portion 1101 a to be in a locked state, the controller 1103 controls the power lock portions 1101 b , 1101 c and 1101 d to bring into the locked state in accordance with the locked state of the power lock portion 1101 a . In such a manner, the locked state of the power lock portion 1101 a is transmitted to the other power lock portions 1101 b , 1101 c and 1101 d . In addition, the controller 1103 may transmit the unlocked state of the power lock portion 1101 a to the power lock portions 1101 b , 1101 c and 1101 d . The controller may be operated through the operation portion 15 .
Further, the unlocked/locked state of each paper feed cassette 6 a , 6 b , 6 c , 6 d is selected by use of alternative mechanical configuration, such as a link member, or a belt. FIG. 7 shows a configuration in which the unlocked/locked state of each paper feed cassette 6 a , 6 b , 6 c and 6 d is selected by use of link members 1201 . FIG. 8 shows a configuration in which the unlocked/locked state of each paper feed cassette 6 a , 6 b , 6 c , 6 d is selected by use of belts 1301 . In these configurations, the lock gears 51 a , 51 b , 51 c and 51 d are mechanically connected with each other by the link members 1201 or the belts. Accordingly, rotation of the lock gear 51 a is transmitted to the other lock gears 51 b , 51 c and 51 d and gang lock of the paper feed cassette 6 a , 6 b , 6 c and 6 d are realized.
The transmission gears may be omitted in the embodiments. In this event, adjacent lock gears are designed to be connected to each other directly. Further, various configurations may be adopted for the gang lock unit if it can perform so-called gang locking in which when at least one of paper feed cassettes with a locking portion is brought into the locked state, the other paper feed cassettes having no locking portion are also brought into the locked state automatically.
Although the embodiments have been described on the case where the paper feed cassette 6 a which is one of the four paper feed cassettes and which is provided in the printer body 1 a is provided with the key hole 14 a and so on as a locking portion, the invention is not limited to such a configuration. For example, the locking portion may be provided not in the printer body 1 a but in one of the paper feed cassette units. Alternatively, a plurality of locking portions may be provided in the paper feed cassette units respectively. The number or assignment of locking portions can be modified variously. However, when the locking portion is provided in the printer body 1 a while no locking portion is provided in any paper feed cassette unit as in the embodiments, the paper feed cassette units can be made to have the same configuration as one another. It can be therefore noted that the configuration in the embodiments is advantageous in terms of manufacturing or selling of the paper feed cassette units.
Although the paper feed cassettes are provided in the printer body 1 a and the paper feed cassette units 1 b , 1 c and 1 d separate from one another respectively in the embodiments, two or more paper feed cassettes may be provided in the printer body 1 a while no paper feed cassette unit is provided. In this case, at least one of the paper feed cassettes provided in the printer body 1 a is provided with a locking portion.
In addition, the arrangement of the plurality of paper feed cassettes is not limited to a vertical line as in the embodiments. Paper feed cassettes may be arranged horizontally. Alternatively, a plurality of paper feed cassettes are disposed both vertically and horizontally. The same thing applies not only to the arrangement of a plurality of paper feed cassettes provided in one unit but also to the arrangement of paper feed cassette units.
Although the locking bar 52 a , 52 b , 52 c , 52 d is made removable to avoid gang locking in the embodiments, the invention is not limited to such a configuration. Gang locking may be avoided by various other means. Alternatively, such a unit capable of avoiding gang locking may be not provided.
Although the embodiments have been described on the case where the printer fixing bar 201 , 202 provided in the support base 200 for supporting the printer is engaged with a hook provided in a paper feed cassette unit so that the printer can be fixed to the support base concurrently with gang locking of the printer, the invention is not limited to such a configuration. The printer may be fixed to the support base concurrently with gang locking by various other means. Alternatively, such an apparatus fixing unit maybe not provided.
When paper feed cassette units separate from the printer body are provided removably, the printer body and the paper feed cassette units are fixed to one another concurrently with gang locking by engagement between hooks and hook destinations in the embodiments. The invention is not limited to such a configuration. The body and the units may be fixed by various other means. Alternatively, such a unit fixing unit may be not provided.
In the embodiments, the hook provided in a paper feed cassette unit having another paper feed cassette unit disposed thereunder serves to fix the units to each other, while the hook provided in a paper feed cassette having no paper feed cassette unit disposed thereunder and being closest to the support base serves to fix the printer to the support base. That is, each hook has different functions in accordance with its disposition. This is advantageous in terms of reduction in number of parts. However, a unit fixing unit and an apparatus fixing unit may be provided separately. For example, another hook may be provided as an apparatus fixing unit.
While the invention has been described in conjunction with the specific embodiments described above, many equivalent alternatives, modifications and variations may become apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention as set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.
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A paper feeder includes: a first paper feed cassette in which to store a recording medium with a lock state; a locking portion that determines whether to bring the lock state of the first paper feed cassette into the unlocked state or the locked state; a second paper feed cassette in which to store a recording medium, capable of selectively entering an unlocked state and a locked state; and a lock state transmitting portion that transmits the lock state of the first paper feed cassette to the second paper feed cassette to bring the second paper feed cassette into the unlocked state or the locked state in accordance with the lock state of the first paper feed cassette.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of copending International Application No. PCT/DE01/00465, filed Feb. 7, 2001, which designated the United States and was not published in English.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a semiconductor component having an MIM capacitor and to an associated fabrication method.
To produce integrated electronic circuits, integrated passive components such as resistors, inductors and capacitors are also needed. For many applications, integrated capacitors need to have series resistances and losses whose magnitudes are as negligible as possible, while having a low area requirement and a low coupling to the substrate. The demand for low series resistances can be met ideally by using metal-insulator-metal (MIM) capacitors. If the metallization planes and intermetal dielectrics normally present in a multilayer metallization are used, capacitors with a very small specific capacitance per unit area (typically below 0.1 fF/μm 2 ) and relatively high tolerances above 20% can be produced. For optimized MIM capacitors, a separate insulating layer and usually a separate thin top metal electrode are generally used.
When integrating an MIM capacitor into a fabrication process for an integrated circuit, there are fundamentally two problems. The process cycle and to some extent also the layer sequence are significantly changed to some extent in the case of the usual methods. The differences between the fabrication methods for components with an integrated MIM capacitor and without an MIM capacitor result in different properties for the metallization system, particularly as regards reliability of the circuit. It is also difficult to achieve high specific capacitance per unit area values for the MIM capacitor, since reliability and tolerance problems quickly arise when using relatively thin capacitor dielectrics. The reason for this is that the typical granular structure of the bottom electrode, which is normally AlCu or AlSiCu, results in that the electrode has a relatively rough surface which can even change in the rest of the process cycle. In addition, with the normal method, the surface is subjected to a series of process steps that can impair the surface quality further. Following deposition and before the top electrode is applied, the capacitor dielectrics are also subjected to process steps which can adversely affect their surface or their layer property.
U.S. Pat. No. 5,391,905 describes an integrated circuit and an associated method for fabricating the circuit, where a top electrode made of polysilicon for a capacitor is deposited together with a contact electrode for a transistor after a bottom electrode made of polysilicon for the capacitor and a capacitor dielectric have been produced.
Published, Non-Prosecuted German Patent Application DE 198 38 435 A1 describes a method for fabricating a semiconductor memory where a bottom capacitor electrode made of polysilicon is deposited into an opening in an insulating film.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a semiconductor component and a fabrication method which overcome the above-mentioned disadvantages of the prior art devices and methods of this general type, which can easily be fabricated using conventional fabrication processes and in which the difficulties specified in the introduction are circumvented.
With the foregoing and other objects in view there is provided, in accordance with the invention, a semiconductor component. The semiconductor component contains a topside for making electrical contact, and a capacitor having a bottom electrode, a top electrode disposed closer to the topside than the bottom electrode, and a capacitor dielectric. The bottom electrode is formed by a specially provided metal electrode layer, and the top electrode is formed by a metallization plane for interconnects.
In the case of the inventive component, the capacitor dielectric and the thin top electrode are not, as is usual, applied to a relatively thick, rough metal layer originating from the standard metallization, but rather, conversely, an optimum thin bottom electrode layer with an optimally protected capacitor dielectric is first produced and structured. A metallization plane is applied thereto and structured, which metallization plane is provided for the normal interconnects and electrical connections of further integrated components. The capacitor dielectric can therefore be deposited on a very smooth, preferably metal (bottom electrode), surface (e.g. TiN) and, following deposition, can be sealed and protected by a thin, likewise preferably metal, layer (e.g. TiN), so that it is not thinned or damaged by other process steps. A particular advantage is that the additionally provided layer which forms the bottom electrode of the MIM capacitor is provided only in the region of the MIM capacitor, which results in that the rest of the layer configuration is not altered as compared with a configuration without a capacitor. The inventive component therefore allows a capacitor with small manufacturing tolerances to be integrated using a normal fabrication process without the previous semiconductor structures of a configuration without a capacitor needing to be changed.
In accordance with an added feature of the invention, a further dielectric is provided and covers and forms the topside. The further dielectric is a passivation layer or an intermetal dielectric layer. The capacitor dielectric that is disposed between the bottom electrode and the top electrode has a relatively high dielectric constant.
In accordance with an additional feature of the invention, the capacitor dielectric is formed of Si 3 N 4 or tantalum oxide.
In accordance with a further feature of the invention, the top electrode has a given surface and the bottom electrode has a surface having a lower roughness than the given surface of the top electrode. The capacitor dielectric covers the surface of the bottom electrode.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for fabricating a semiconductor component having an integrated capacitor. The method includes applying a passivation to a topside of a component structure, depositing a metal layer onto the passivation and the metal layer functions as a bottom electrode of the integrated capacitor, depositing a dielectric layer on the metal layer, and depositing a metallization plane on the dielectric layer. The metallization plane is structured to form interconnects and/or contact areas, and to form a top electrode of the integrated capacitor. At least one covering dielectric is deposited and contact holes for at least one of the bottom electrode and the top electrode are formed in the covering dielectric. The contact holes are then filled with an electrically conductive material.
In accordance with an added mode of the invention, there are the steps of producing further contact holes in the passivation before performing the step of depositing the metal layer, and filling the further contact hoes with contact hole fillings formed from an electrically conductive material for producing an electrically conductive connection to a contact area situated below the passivation and for electrically connecting the bottom electrode. The metal layer is deposited above the contact hole fillings during the step of depositing the metal layer.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a semiconductor component and a fabrication method, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1F are diagrammatic, sectional views showing steps for the construction of a first embodiment of a semiconductor component according to the prior art;
FIGS. 2A-2F are diagrammatic, sectional views showing steps for the construction of a second embodiment of the semiconductor component according to the prior art;
FIGS. 3A-3E are diagrammatic, sectional views showing steps for the construction of a third embodiment of the semiconductor component according to the prior art;
FIGS. 4A-4F are diagrammatic, sectional views showing steps for the construction of a first embodiment of the semiconductor component according to the invention; and
FIGS. 5A-5F are diagrammatic, sectional views of the construction of a second embodiment of the semiconductor component according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawing in detail and first, particularly, to FIGS. 1A-1F thereof, there is shown various intermediate product stage of a known fabrication method. In the case of the layer structure shown in cross section in FIG. 1A , right at the bottom, there is a passivation 10 which can be applied to a semiconductor layer structure 100 as an insulating layer, for example, or can be a top dielectric layer of a metallization with intermetal dielectrics which contain one or more metallization planes. In this example, a standard metallization applied thereto has a sandwich structure with a bottom electrically conductive layer 11 and a top electrically conductive layer 12 which have an insulating layer 13 situated between them. The top electrically conductive layer 12 is used as the bottom electrode of the MIM capacitor. Onto the layer 12 , a capacitor dielectric 3 is deposited (e.g. a plasma nitride with a thickness of less than 0.1 μm) followed by a further thin metal layer 2 used as the top electrode 2 of the capacitor (e.g. TiN with a thickness of approximately up to 0.1 μm). A suitable mask is used to structure the top electrode 2 , with either the capacitor dielectric 3 or the electrically conductive layer 12 below that being used as an etching stop layer. The result of the step is shown in FIG. 1 B. This is followed, in line with FIG. 1C , by structuring of the standard metallization 1 to form a portion for the MIM capacitor 123 and a portion for the interconnect 14 . FIG. 1D shows that a topside of the structure is embedded into a covering dielectric 5 . In line with FIG. 1E , contact holes 6 provided for electrical connection of the metallizations are etched into the dielectric 5 . The contact holes 6 are filled in a manner that is known per se, so that the structure shown in FIG. 1F is produced. A base metal 7 (usually Ti/TiN) can also first be deposited in the contact holes 6 before the actual contact hole filling (typically tungsten) is introduced into the contact holes 6 . This produces the electrical connections for the bottom capacitor electrode (contact hole fillings 81 ), for the top capacitor electrode (contact hole fillings 82 ) and for the interconnects (contact hole fillings 83 ).
An alternative to the known method is shown in FIGS. 2A to 2 F. Again, starting from the standard metallization 1 , the metallization is now structured in line with FIG. 2B before the top capacitor electrode is applied. Only when the interconnects 14 have been structured are the capacitor dielectric 30 and the thin electrically conductive layer 20 provided for the top capacitor electrode applied. When the top conductive layer 20 has been structured, the capacitor dielectric 30 also remains in the region of the interconnects 14 on the topside of the structure, which results in that the interconnects 14 are surrounded by the dielectric 30 on three sides. In line with FIGS. 2D to 2 F, the covering dielectric 5 is then applied, the contact holes 6 are etched and the base metal and the contact hole fillings are introduced into the holes, in line with the variant shown in FIGS. 1D to 1 F. When etching the contact holes 6 in line with FIG. 2E , it is also necessary to etch through the capacitor dielectric 30 . If the capacitor dielectric 30 is completely removed from the rest of the surfaces at the same time as the top capacitor electrode is structured, then there is the risk that the normally applied top antireflective layer (usually TiN) will also be removed from them. The antireflective layer, the actual interconnect material (e.g. AlCu) and the base metal situated below that form a sandwich structure whose integrity is crucial for the electromigration strength of the metallization system. The etching process destroys or at least damages the sandwich structure. In the region outside the MIM capacitor that is to be produced, the capacitor dielectric is therefore not removed from the surfaces of the conductive layers (generally metal layers) until the contact holes 6 are produced.
Another option for producing MIM capacitors is, in line with FIGS. 3A to 3 E, to follow the application of an intermetal dielectric 4 to the structured standard metallization with the production of a cutout 9 in the dielectric 4 , shown in FIG. 3B , as a window above the top conductive layer 12 . The capacitor dielectric 30 is then deposited on the surface and into the cutout 9 , in line with FIG. 3 C. The contact holes 6 are then etched in line with FIG. 3 D. When the contact hole fillings are introduced after the base metallization 7 has possibly also been applied, the electrical connections for the bottom capacitor electrode (the contact hole filling 81 ) and for the interconnect (the contact hole filling 83 ) are then produced. The cutout 9 is likewise filled with the metal for contact hole filling. This produces a top capacitor electrode 80 . Drawbacks of this method are that, before the base metalization is deposited, a cleaning step needs to be performed in order to improve the contact resistances. The cleaning step thins the capacitor dielectric exposed at this time and possibly also damaging it, and that the capacitor dielectric is retained as an additional layer in the layer structure with the intermetal dielectric 4 and can have an adverse effect on the properties of the metallization system (stress, barrier effect for H 2 diffusion)
FIGS. 4A to 4 F and 5 A to 5 F show cross-sectional views of intermediate products after various steps in fabrication methods according to the invention.
As FIG. 4A shows, the thin conductive layer 2 , preferably a metal, is first deposited on the insulating passivation 10 (this can be an intermediate oxide or an intermetal dielectric) as a bottom electrode 2 . As soon as possible thereafter, an electrically insulating layer 3 is applied thereto as a capacitor dielectric 3 . The capacitor dielectric 3 likewise has the smallest possible layer thickness and is preferably made of a material with a high dielectric constant (e.g. Si 3 N 4 or tantalum oxide). Finally, a conductive top layer 11 can be applied to seal the dielectric 3 and is a top electrode 11 of the capacitor that is to be produced. Quickly sealing the capacitor dielectric 3 with the conductive layer 11 protects the dielectric 3 from thinning and from other damage resulting from further process steps. The layers 2 , 3 , 11 can be produced using normal method steps such as sputtering, vapor deposition, chemical vapor deposition (CVD), physical vapor deposition (PVD) or electrodeposition.
In line with FIG. 4B , the deposited layer sequence 2 , 3 , 11 is then structured using a photographic technique and a suitable etching step. Following removal of the photoresist used in this context and any necessary cleaning, the processing as customary in a multilayer metallization process continues with deposition of a metallization layer (e.g. interconnect metal and antireflective layer) and the structuring thereof.
FIG. 4C shows such a structure with a standard metallization 1 and an interconnect 14 structured therein. The top electrode 11 of the capacitor is now part of the standard metallization 1 . In this example shown in FIG. 4D , more extensive structuring exposes part of the capacitor dielectric 3 . In this case too, the standard metallization 1 contains, as an example, a sandwich structure containing the conductive layer 11 , a top conductive layer 12 and an insulating layer 13 disposed between them. The structure is covered with the dielectric 5 in which the contact holes 6 are produced in line with FIG. 4 E. In the region of the contact holes 6 provided for the bottom electrode, the capacitor dielectric 3 exposed there in a prior structuring step is etched through. In line with FIG. 4F , the contact hole fillings produced on the base metal 7 in accordance with the prior art are used to produce the electrical connections for the bottom electrode (the contact hole filling 84 ), the top electrode (the contact hole fillings 85 ) and the interconnects (contact hole fillings 83 ). The contact holes 6 can each be individual cylindrical openings. As shown by the illustration of the cross sections in FIGS. 4E and 4F , a circular annular opening disposed along the edge of the respective capacitor electrode can also be produced, however.
The structuring of the metallizations applied above the capacitor dielectric 3 in order to obtain the structure shown in FIG. 4C can also entail the capacitor dielectric 3 even then being removed from the regions of the surface of the bottom electrode 2 which are at the side of that region above which the top electrode 11 of the finished capacitor is disposed. When producing the contact holes 6 as shown in FIG. 4E , the dielectric 5 can then be etched out directly on that surface of the bottom electrode 2 which is not covered by the capacitor dielectric 3 . This simplifies etching of the contact holes 6 , since it is only necessary to etch through one dielectric 5 and not additionally through the capacitor dielectric 3 that is preferably made of a material having a relatively high dielectric constant.
In the embodiment shown in FIGS. 5A to 5 F, production of the connection for the bottom electrode 2 differs from that in the exemplary embodiment already described. FIG. 5A shows that, in the case of the embodiment, the contact holes in the passivation 10 which are filled with a contact hole filling 18 , preferably on a base metal 17 , before the bottom electrode 2 is deposited are provided for connecting the bottom electrode 2 . The rest of the method steps are based on the exemplary embodiment in FIGS. 4A-4F , but with the difference that, in line with FIG. 5E , no contact holes need to be produced in the dielectric for the bottom electrode 2 of the capacitor.
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A thin lower electrode layer having an optimally protected capacitor dielectric is produced and structured. A conventional metallization layer for strip conductors is placed thereon as an upper electrode and structured. The capacitor dielectric can be deposited on a very even, preferably metallic surface (e.g. preferably TiN), sealed by a thin, preferably metallic layer (e.g. TiN) and protected so that is does not become thinned or damaged by other process steps.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application Ser. No. 60/546,685, entitled “Oil Free Head Valve for Pneumatic Nailers and Staplers,” filed Feb. 20, 2004 which is herein incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention generally relates to the field of power tools, and particularly to a head valve assembly for pneumatic fasteners, such as pneumatic nailers and staplers.
BACKGROUND OF THE INVENTION
Pneumatic power tools are commonly employed in a variety of work places in order to accomplish various tasks. Typical pneumatic power tools include pneumatic fasteners, such as pneumatic nailers and pneumatic staplers. A typical system within a pnemutic fastener generates the desired hammering force by employing compressed air (typically supplied by a separate air compressor), a valve assembly including a valve plunger, and a piston assembly including a sliding piston that drives a long blade. In such system, the piston is forced downward when the air pressure above the piston head is greater than below it. Moreover, the piston is forced into an “up” position when the air pressure below the piston is greater than above it. In addition, a trigger assembly is employed to allow a user to control the actuation of the pneumatic fastener.
In use, the pneumatic fastener is actuated by a user activating the trigger assembly. Upon actuation, the trigger assembly closes the trigger valve while opening a passageway to the atmosphere as such compressed air is prevented from flowing above the valve plunger whereby pressure beneath the plunger is greater than pressure above the plunger. This configuration causes the valve plunger to rise up and compressed air to travel to the piston head. The piston and the blade are then driven downward by the compressed air causing a fastener (e.g. a nail or staple) to be propelled from the chamber. The downward sliding of the piston, in turn, channels the air inside the cylinder through a series of holes into a return air chamber. When a user then releases the trigger assembly, the plunger is pushed back into place by the compressed air and air flow to the piston head is blocked. In the absence of downward pressure, the piston head is also pushed back up by the compressed air in the return air chamber. As a result, the air above the piston head is forced out of the gun and into the atmosphere.
Although the standard pneumatic fastener, such as a nailer, works well for driving even thick nails through hard material such fasteners are disadvantageous in many respects. First, the standard pneumatic fastener typically employs functional features for controlling and directing air flow which involve expensive and time consuming manufacturing processes and result in decreased performance characteristics. For example, many pneumatic fasteners require a cross hole to be drilled and plugged through an outer cap or an angled hole to be drilled through such cap in order to get supply air from the air source, through the outer cap and to the back side of the valve piston chamber. One disadvantage associated with this design is possible significant increases in manufacturing costs, which in turn may be passed onto the consumer. An additional disadvantage associated with such configuration is that employment of machined holes provide rough surfaces (e.g. edges) over which the air must travel. The rough surfaces may increase air flow turbulence/friction thereby reducing the efficiency of air flow travel and possibly decreasing the efficiency of the pneumatic fastener. Current solutions to overcome increased friction typically involve the application of a lubricant to the rough surfaces. Utilization of such lubricants may increase the cost of operating pneumatic fasteners while also possibly simultaneously resulting in decreased productivity as the pneumatic fasteners must halt operation in order to have the lubricant provided. In addition, the aforementioned disadvantage is continuous for the lubricant has a limited useful lifespan and must be continuously replaced to assist in smoothing the surfaces over which the air must travel.
Therefore, it would be desirable to provide a pneumatic fastener which requires neither the machining of the outer cap to establish air flow patterns nor application of a lubricant to prevent increases in air flow friction.
SUMMARY OF THE INVENTION
Accordingly, in a first aspect of the present invention a head valve assembly for a pneumatic fastener including a piston assembly reciprocated within a cylinder assembly for driving a fastener and a housing having an end cap for at least partially enclosing the head valve assembly is provided. In an exemplary embodiment, the head valve assembly includes a valve piston for causing supply pressure to be ported to the piston assembly for moving the piston assembly within the cylinder assembly from a non-actuated position to an actuated position for driving the fastener. Further, an inner cap is disposed within the end cap around the valve piston. The inner cap includes an inlet port for porting pressure to the valve piston. In addition, a main seal is coupled to the valve piston for sealing the cylinder assembly from supply pressure while pressure is ported to the valve piston by the inner cap for holding the piston assembly in the non-actuated position. The main seal seals pressure ported to the valve piston by the inner cap from supply pressure ported to the piston assembly.
In specific embodiments of the instant head valve assembly, the inner cap may further include an exhaust port for porting exhaust from the head valve assembly. Further, the inner cap may be formed of a lubricious plastic. In additional embodiments, the main seal includes a lip seal for forming a seal with the inner cap and may provide shock absorption to the piston assembly. In further embodiments, the main seal may be coupled to the valve piston by a snap-lock mechanism. In such embodiment, the main seal may include a plurality of legs while the valve piston may include a plurality of leg receivers for coupling the main seal to the valve piston. For example, the snap-lock assembly comprises a plurality of legs extending from the main seal and a plurality of leg receivers disposed in an inner surface of the valve piston, each of the plurality of legs being received in a corresponding one of the plurality of leg receivers for coupling the main seal to the valve piston. In such embodiment, the piston assembly may include a projection, the plurality of legs for receiving and retaining the projection upon return of the piston assembly from the actuated position to the non-actuated position. In further exemplary embodiments, a lip seal is disposed between the valve piston and the inner cap.
In additional specific embodiments of the head valve assembly, a compression spring may be employed for biasing the valve piston toward the piston assembly and causing the main seal to seal the cylinder assembly from supply pressure. For instance, the compression spring may trap the plurality of legs for preventing the main seal from separating from the piston valve by the piston assembly as the piston assembly moves from the non-actuated position to the actuated position. It is contemplated that the present head valve assembly may be coupled to various types of pneumatic fasteners including a pneumatic nailer and a pneumatic stapler.
In an additional exemplary aspect of the present invention, a fastener device including dual actuation mode capability is disclosed. The apparatus of the present invention permits a user to select between a contact actuation mode in-which a user pulls or draws a trigger and actuation of the fastener device is initiated by a contact safety assembly and a sequential actuation mode in-which the contact safety assembly is depressed first and the trigger initiates actuation of the fastening event. The fastener device includes a sliding contact safety assembly which is configured to reciprocate towards/away from a driver housing. The contact safety assembly includes a contact member for contacting a workpiece. A rotating rod is pivotally operable with respect to an intermediate linkage. A pivot pin may be attached to the intermediate linkage. The rotating rod may include a recess for receiving the pivot pin. The pivot pin is configured with a first shoulder or ledge and a second shoulder which is off-set from the first shoulder. The second shoulder is further away from an end of the rod, opposite the linkage, than the second shoulder. The rod may be rotated to orientate either the first or the second shoulders toward a trigger assembly. The trigger assembly is pivotally coupled, via a pivot pin, to the driver housing. Trigger assembly is constructed so that a portion of the trigger contacts with the selected shoulder on the rotating rod so that the rod acts a stop for the trigger. A trigger lever is preferably included for actuating a valve or the like for permitting compressed air (in the case of a pneumatic fastener) to enter a driver chamber for forcing a piston with a driver blade attached thereto to secure a fastener. A toggle switch may be included to engaged with the rod to allow for efficient rotation. Preferably, a toggle switch is configured to remain in a fixed position while the contact safety assembly slides.
In a further aspect, a depth adjustment system is included to permit varying the depth to which a fastener to be secured will be driven. In this aspect of the invention, a threaded thumb wheel is included to engage with a threaded portion of a pivot pin included on the intermediate linkage. A washer, biased into engagement with the thumb wheel, having a series of detents is included to secure the thumb wheel in the desired position along the pivot pin. The thumb wheel may be manipulated to increase or decrease the overall length of the contact safety system thereby varying the extent to which a fastener will be driven into a workpiece.
In a further exemplary aspect of the present invention, an adjustable handle exhaust assembly is provided. The adjustable handle exhaust assembly includes a base, which includes a base plate and a protrusion protruding from the base plate. The protrusion is centrally hollow and includes an inner surface and an outer surface. The base plate includes an inlet opening and an exhaust opening defined therethrough. The inlet opening is interconnected with a channel defined by the inner surface of the protrusion. A cap is coupled to and supported by the base and includes an exit opening. A quick connector coupler is positioned inside the channel defined by the inner surface of the protrusion. When coupled to a pneumatic fastener, the quick connector coupler is suitable for connecting to an air supply hose to input compressed air to the pneumatic fastener via the channel defined by the inner surface of the protrusion and the inlet opening, and exhaust from the pneumatic fastener may exit through the exhaust opening and the exit opening.
In a still further exemplary aspect of the present invention, a pneumatic fastener is provided. The pneumatic fastener includes a handle which includes an inlet channel and an outlet channel. An adjustable handle exhaust assembly is coupled to the handle for connecting to an air supply hose to input compressed air to the pneumatic fastener via the inlet channel and outputting exhaust of the pneumatic fastener via the outlet channel to outside. The adjustable handle exhaust assembly includes a base, a cap and a quick connector coupler. The base includes a base plate and a protrusion protruding from the base plate. The protrusion is centrally hollow and includes an inner surface and an outer surface. The base plate includes an inlet opening and an exhaust opening defined therethrough. The inlet opening is interconnected with a channel defined by the inner surface of the protrusion. The cap is coupled to and supported by the base and includes an exit opening. The quick connector coupler is positioned inside the channel defined by the inner surface of the protrusion. The quick connector coupler is suitable for connecting to the air supply hose to input the compressed air to the pneumatic fastener via the channel defined by the inner surface of the protrusion, the inlet opening, and the inlet channel, and the exhaust may exit through the outlet channel, the exhaust opening and the exit opening.
In another exemplary aspect of the present invention, a handle for a pneumatic fastener is provided. The handle includes an inlet channel for inputting compressed air into the pneumatic fastener, an outlet channel for outputting exhaust of the pneumatic fastener to outside, and an adjustable handle exhaust assembly coupled to the handle. The adjustable handle exhaust assembly includes a base, a cap, and a quick connector coupler. The base includes a base plate and a protrusion protruding from the base plate. The protrusion is centrally hollow and includes an inner surface and an outer surface. The base plate includes an inlet opening and an exhaust opening defined therethrough. The inlet opening is interconnected with a channel defined by the inner surface of the protrusion. The cap is coupled to and supported by the base and includes an exit opening. The quick connector coupler is positioned inside the channel defined by the inner surface of the protrusion. The quick connector coupler is suitable for connecting to an air supply hose to input the compressed air to the pneumatic fastener via the channel defined by the inner surface of the protrusion, the inlet opening, and the inlet channel, and the exhaust may exit through the outlet channel, the exhaust opening and the exit opening.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and together with the general description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which:
FIG. 1 is an illustration of a pneumatic fastener in accordance with an exemplary embodiment of the present invention;
FIG. 2 is an exploded view of the pneumatic fastener including a head valve assembly coupled with a piston assembly in accordance with an exemplary embodiment of the present invention;
FIG. 3 is a cut away view of a handle of the pneumatic fastener including a handle adapter coupled with an inlet channel and an exhaust channel coupled with a handle exhaust;
FIG. 4 is an illustration of the head valve assembly, the inner cap having an inner diameter coupled with a main seal and valve piston;
FIG. 5 is an illustration of the main seal connected with the valve piston through use of a snap lock mechanism;
FIG. 6 is an isometric illustration of the head valve assembly coupled with a housing and a cap of the pneumatic fastener, wherein the head valve assembly at least partially occupies a fully defined recessed area of the pneumatic fastener;
FIG. 7 is an isometric illustration of the housing including a housing inlet port and a housing outlet port;
FIG. 8 is a cross-sectional view of the pneumatic fastener including the head valve assembly coupled with the piston assembly and the housing, the main seal and valve piston shown in a down position relative to the inner cap of the head valve assembly, in accordance with an exemplary embodiment of the present invention;
FIG. 9 is an expanded cross-sectional view of the pneumatic fastener wherein the main seal and valve piston are shown in an up position relative to the inner cap of the head valve assembly;
FIG. 10 illustrates the head valve assembly of the present invention employing a diaphragm coupled with the inner diameter of the inner cap;
FIG. 11 is a partial side view illustration of a pneumatic fastener including a dual actuation mode assembly;
FIG. 12 is an exploded view of the contact safety illustrated in FIG. 11 ;
FIG. 13A is a cut-away side view of a dual actuation mode assembly;
FIG. 13B is a cut-away side view of the dual actuation mode assembly illustrating a rotating rod in contact actuation mode;
FIG. 13C is a cut-away side view of the dual actuation mode assembly illustrating a rotating rod in sequential actuation mode;
FIG. 14 is an illustration of an adjustable handle exhaust assembly for use with a pneumatic fastener; and
FIG. 15 is an exploded view of the adjustable handle exhaust assembly.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.
Referring now to FIG. 1 , an exemplary embodiment of a pneumatic fastener 100 in accordance with the present invention is provided. In the exemplary embodiment, the pneumatic fastener 100 includes a handle 102 having a first end 103 and a second end 105 . In the present embodiment, a housing 104 is coupled with the first end 103 of the handle 102 . The handle 102 further includes a handle adapter 156 , which enables the coupling of a compressed air supply to the pneumatic fastener 100 . In addition, a trigger assembly 108 for controlling the firing of the pneumatic fastener 100 may be coupled with the handle 102 , proximal to the first end 103 .
Referring now to FIG. 2 , in the exemplary embodiment the housing 104 defines a housing recessed area 125 within which a piston assembly including a cylinder 130 and a piston 134 may be mounted. The cylinder 130 is slidably coupled with the piston 134 which includes a piston projection 136 . It is understood that the piston 134 may operationally engage a driver blade for driving a fastener by providing force to the driver blade. The piston projection 136 , in the current embodiment, is enabled in a generally cylindrical shape. Alternatively, the piston projection 136 may be configured in various shapes, such as rectangular, spherical, and the like.
In an exemplary embodiment, the housing 104 includes a first end 107 and a second end 109 . The first end of the housing 107 may couple with various mechanical devices to enable the functionality of the nailer, such as a nose casting assembly, which may enable the operation of the driver blade. The second end 109 of the housing 104 includes a first housing fastening point 110 , a second housing fastening 111 , a third housing fastening point 112 , and a fourth housing fastening point 113 . In an advantageous embodiment, the fastening points allow the coupling of an outer cap 114 with the second end 109 of the housing 104 . It is understood that the outer cap 114 may be composed of various materials, such as aluminum, steel, plastic, and the like. The fastening points may enable the use of a variety of fasteners. Suitable fasteners may include a screw, bolt, clip, pin, and the like. In the current embodiment, the cap 114 includes a first cap fastening point 115 , a second cap fastening point 116 , a third cap fastening point 117 , and a fourth cap fastening point 118 . The cap fastening points align with the housing fastening points to enable the fasteners to engage with the housing 104 and the cap 114 thereby securely affixing their position relative to one another.
In the exemplary embodiment, the housing recessed area 125 is defined on one end by the first end 107 of the housing 104 and on the other end by the second end 109 of the housing 104 . The cap 114 further defines an outer cap recessed area 119 . When the cap 114 is coupled with the housing 104 , a fully defined recessed area 129 (as illustrated in FIG. 6 ), of the pneumatic fastener 100 is established. It is understood that various configurations of the housing 104 and the cap 114 may define variously configured recessed areas 129 . It is contemplated that the configurations of the housing 104 and the cap 114 may partially encompass the recessed area 129 . Further, the housing 104 and the cap 114 may be configured for aesthetic and/or functional purposes. For example, contouring may establish the housing 104 and the cap 114 with an advantageous appearance, which may also provide for increased functionality by providing a contoured grip region. Still further, grip regions may be established with material for grasping engagement by the hand of the user of the pneumatic fastener 100 , including soft grips and the like.
As illustrated in FIG. 2 , the housing 104 may further define an inlet (supply) port 121 and an outlet (exhaust) port 123 . The configuration of the housing inlet port 121 and the housing outlet port 123 may vary. In a preferred embodiment, the housing inlet port 121 is of a generally cylindrically shaped conduit extending through the housing 104 while the housing outlet port 123 is of a generally rectangularly shaped conduit extending through the housing 104 . It is understood that the shape and/or configuration of the housing inlet and outlet ports may be varied as contemplated by those of ordinary skill in the art. For instance, the diameter of the housing inlet port 121 may be increased or decreased to alter the characteristics of the supply pressure. As shown in FIG. 3 , the housing inlet port 121 acts as a conduit for the supply of compressed air coming through the inlet channel 126 via the handle adapter 156 connection. In addition, the housing outlet port 123 acts as a conduit for the air exhausted after the firing of the pneumatic fastener, directing the exhaust to the outlet channel 128 and then through a handle exhaust 158 of the handle 102 .
In further exemplary embodiments, as illustrated in FIG. 2 , the pneumatic fastener 100 includes a head valve assembly with an inner cap 150 for directing the flow of air to and from the piston 134 of the piston assembly of the fastener 100 . In an exemplary embodiment, a basket 132 is included within the inner cap 150 for stabilizing the piston 134 . In an alternative embodiment, the basket 132 is not included within the inner cap 150 , but directly seated upon the cylinder 130 .
In the present exemplary embodiment, the head valve assembly at least partially occupies the recessed area 129 . Further, a main seal 142 is adjustably coupled with an inner diameter 151 of the inner cap 150 . The main seal 142 is further coupled with the piston 134 and a valve piston 144 . In a preferred embodiment, the main seal 142 is seated upon the piston 134 . This coupling allows the main seal 142 to provide shock-absorption to the piston 134 of the pneumatic fastener 100 . The main seal 142 , in a preferred embodiment, may be composed of a urethane material. Alternative materials, such as other plastics, metals, and the like, may be employed as contemplated by those of skill in the art which include the desired durability. Additionally, in such advantageous embodiment, the valve piston 144 is composed of a plastic material. It is further preferred that the plastic be an acetal which includes compounds that are characterized by the grouping C(OR) 2 , such as Delrin®, a registered trademark owned by the E.I. du Pont de Nemours and Company. Such composition provides the valve piston 144 with a reduced frictional coefficient while still enabling a secure coupling with the main seal 142 .
As further illustrated in FIG. 2 , in an exemplary embodiment, an O-ring gasket 190 connects the top side 180 , of the inner cap 150 , with an inner wall 120 of the cap recessed area 119 of the aluminum cap 114 . The O-ring gasket 190 provides a seal between the aluminum cap 114 and the inner cap 150 . It is understood that the O-ring gasket 190 may enable various degrees of stretching and/or deflecting depending on the materials used to establish the O-ring gasket 190 . This seal assists in directing the air flow provided into and out of the head valve assembly 140 via the inner cap inlet conduit 182 and the inner cap outlet conduit 184 . In a preferred embodiment, the O-ring gasket 190 may nest in a groove established in the inner wall 120 of the aluminum cap 114 . In an alternative embodiment, the O-ring gasket 190 may nest in a groove established in the top side 180 of the inner cap 150 . It is further contemplated that the O-ring gasket 190 may be integrated with either the inner wall 120 of the aluminum cap 114 or the top side 180 of the inner cap 150 .
As illustrated in FIG. 4 , the inner cap 150 is further comprised of an inner cap exhaust conduit 184 . The inner cap outlet conduit 184 directs the flow of exhausted air to the housing outlet port 123 , established in the second end 109 , of the housing 104 , which is connected to the exhaust channel 128 within the handle 102 . Thus, the exhausted air is removed from the head valve assembly 140 via the inner cap 150 .
It is contemplated that the coupling of the main seal 142 with the valve piston 144 may be accomplished in a variety of ways. For example, in an exemplary embodiment, the main seal 142 is coupled with the valve piston 144 via a snap lock mechanism. In an advantageous embodiment, as illustrated in FIGS. 4 and 5 , the snap lock mechanism is enabled by a first leg 160 , a second leg 162 , and a third leg 164 which are connected to the main seal 142 . In configuration, the legs 160 through 164 generally extend from the main seal 142 and include a tapered undercut on a flange included within each of the three legs. Further, on the end opposite the connection to the main seal 142 , each leg terminates in a tab, which generally extends from the leg. The legs are formed about a piston projection receiving point 166 . In the current embodiment, the piston projection receiving point 166 is an aperture, which extends through the main seal 142 .
As illustrated in FIG. 5 , in an exemplary embodiment, the legs 160 through 164 of the main seal 142 couple with a first leg receiver 172 , a second leg receiver 174 , and a third leg receiver 176 , respectively. In the present embodiment, the leg receivers are disposed within a valve piston inner diameter of the valve piston 144 . In a preferred embodiment, the three leg receivers are established by a ledge 171 . In such embodiment, the ledge 171 includes three grooves for receiving the three legs of the main seal 142 . In an alternative embodiment, the three leg receivers may be established as pockets disposed within the inner diameter of the valve piston 144 . The three leg receivers 172 through 176 are configured with a matching profile to that of the three legs 160 through 164 .
In operation, the three legs of the main seal 142 may be inserted within the three leg receivers of the valve piston 144 . Upon being fully inserted, the tabs formed at the terminus of each leg may snap into place with respect to the leg receivers. The snapping into place may be accomplished in a variety of manners. In the present example, the material composition and configuration of the legs provide the force which snaps the tabs into place. The tabs assist in securing the position of the main seal 142 relative to the valve piston 144 by coupling the tabs against the valve piston 144 . In alternative embodiments, the snap mechanism may be enabled as a spring loaded assembly and the like as contemplated by those of ordinary skill in the art. It is further contemplated that the main seal 142 and the valve piston 144 may be an integrated single unit.
In further exemplary embodiments, a secondary coupling of the valve piston 144 with the main seal 142 occurs via a tongue and groove assembly. The valve piston 144 includes a tongue member disposed about the circumference of a bottom edge of the valve piston 144 . In a corresponding circumferential position on the main seal 142 , a groove is established. Thus, when the main seal 142 is coupled with the valve piston 144 , via insertion of the plurality of legs into the plurality of leg receivers, the tongue is inserted within the groove to provide secondary coupling support. It is contemplated that the secondary coupling characteristics may be provided through various alternative mechanisms. For example, the secondary coupling may be established by employing a friction lock mechanism, a compression lock mechanism, a latch mechanism, and the like, without departing from the scope and spirit of the present invention.
As illustrated in FIG. 6 , in an exemplary embodiment, the piston projection receiving point 166 is configured to receive the piston projection 136 . Therefore, as the configuration of the piston projection 136 is altered so to may the piston projection receiving point 166 and the three legs 160 , 162 , and 164 be altered to accommodate this change. The three legs 160 through 164 , in a preferred embodiment, are enabled to trap and hold the piston projection 136 when extended through the piston projection receiving point 166 .
The securing of the piston projection 136 by the three legs may be accomplished using various mechanisms. In a preferred embodiment, the three legs serve as a piston catch by providing a friction fit for engaging against the piston projection 136 . Alternatively, the enabling of the piston catch may occur through the use of compression assemblies, ball joint assemblies, and the like. It is understood that the three legs trap and hold the piston projection 136 when the piston 134 is established in an “up” position (as illustrated in FIG. 9 ). It is further contemplated that the cylinder 130 may include a counter bore to further assist in maintaining the piston in the “up” position. The “up” position is the pre-fire position or the position the piston 134 returns to after the pneumatic fastener 100 has fired, using the compressed air to drive the piston 134 into a “down” position (as illustrated in FIG. 8 ). The “down” position provides the force for driving the driver blade through the nose casting, engaging with a nail located within the nose casting, and driving the nail into a surface against which the nose casting is set. The piston catch established by the present invention may provide increased efficiency by reducing any unwanted travel by the piston 134 towards the “down” position when the pneumatic fastener 100 is not being fired. For instance, when the pneumatic fastener 100 is set in a position to fire the user may tap the surface, inadvertently, being operated upon with the gun. This tap may result in the piston 134 traveling towards the “down” position. This travel may reduce the operational effectiveness of the pneumatic fastener 100 by limiting the range of travel of the piston 134 during firing of the gun 100 , thereby, limiting the force provided by the piston 134 in driving the fastener, such as the nail, by the pneumatic fastener 100 . This limited force may result in the fastener failing to reach the desired depth, such as by not recessing properly, which may have the effect of requiring additional time spent to accomplish a task. This may limit productivity and increase expenses associated with completing the task.
In an exemplary embodiment, as illustrated in FIGS. 8 and 9 , a compression spring 148 is coupled against a bumper seal 152 on one end and the three legs 160 , 162 , and 164 , snapped in position relative to the valve piston 144 , on the opposite end. In the exemplary embodiment, the compression spring 148 extends through a spring receiving point 181 (as shown in FIG. 4 ) of the inner cap 150 . In the current embodiment, as shown in FIG. 4 , the spring receiving point 181 is an aperture through a top side 180 of the inner cap 150 . The coupling against the three legs snapped into position relative to the valve piston 144 enables the compression spring 148 to “trap” the legs (as illustrated in FIG. 9 ), thereby, assisting in preventing the main seal 142 from being pulled away from the valve piston 144 by the piston 134 when fired.
The functionality of the compression spring 148 in combination with the snap fit of the main seal 142 with the valve piston 144 assists in enabling the main seal 142 to establish and maintain a seal between the supply pressure and the pressure behind the valve piston 144 . In the current embodiment, the main seal 142 includes a main lip seal 143 to further assist in providing the above mentioned functionality. The main lip seal 143 further enables the main seal 142 to slidably couple with the inner diameter 151 of the inner cap 150 . Thus, the main lip seal 143 enables the main seal 142 to travel within the inner cap 150 and maintain the seal between the supply pressure and the pressure behind the valve piston 144 . It is understood, that the travel of the main seal 142 translates into a travel of the valve piston 144 , within the inner cap 150 , and the compression or extension of the compression spring 148 . A secondary lip seal 146 is set upon the valve piston 144 . The secondary lip seal 146 is set on the side opposite the coupling of the main seal 142 against the valve piston 144 . The secondary lip seal 146 may assist in providing a seal between the valve piston 144 and the inner cap 150 .
It is contemplated that the inner cap 150 may be composed of various materials. For example, the inner cap 150 may be composed of Delrin®, a registered trademark owned by the E.I. du Pont de Nemours and Company. A composition including Delrin® is advantageous for Delrin® is an acetal which is a lubricious plastic providing a surface which may reduce the amount of turbulence/friction involved with the travel of the compressed air into or out of the head valve assembly 140 of the present invention. Further, the use of Delrin® for the valve piston 144 , as stated previously, may reduce the amount of turbulence/friction encountered by the valve piston 144 during travel of the valve piston 144 within the inner diameter 151 of the inner cap 150 . The materials used for the inner cap 150 may further comprise alternative plastics, Teflon® (a registered trademark of DuPont), silicone, and the like. While the present invention is enabled with the inner cap 150 , which directs the air flow into and out of the head valve assembly 140 without requiring lubricants to be added, it is contemplated that various lubricants may be used in conjunction with the present invention. Lubricants, such as Teflon® based lubricants, silicone based lubricants, and aluminum disulfide based lubricants may be employed without departing from the scope and spirit of the present invention.
In an alternative embodiment, the main seal 142 and valve piston 144 may be replaced by a diaphragm 198 , as illustrated in FIG. 10 . The diaphragm 198 provides the functionality of the main seal 142 coupled with the inner diameter 151 of the inner cap 150 , of the head valve assembly 140 . The diaphragm may also couple with the cylinder 130 , at least partially surrounding the cylinder 134 . The diaphragm may be composed of various materials, which provide various degrees of stretching and/or deflecting of the diaphragm. This stretching and/or deflecting may translate into movement by the diaphragm 198 within the inner diameter 151 . As previously stated, this may further translate into the extension and/or compression of the compression spring 148 . It is still further contemplated that the use of the diaphragm 198 may eliminate the need for the compression spring 148 . It is understood that the configuration of the diaphragm 198 may be altered to accommodate the needs of the manufacturer, consumer, or those of ordinary skill in the relevant art. It is further contemplated that the diaphragm 198 may be employed in conjunction with the main seal 142 and the valve piston 144 . The diaphragm 198 may couple with the main seal 142 and any stretching/deflecting of the diaphragm 198 within the inner diameter 151 of the inner cap 150 may translate into movement of the main seal 142 and valve piston 144 within the inner diameter 151 .
During use, compressed air travels through the inner cap 150 and into the head valve assembly 140 via an inner cap inlet conduit 182 . The inner cap inlet conduit 182 establishes an air flow pattern through the inner cap 150 from the inlet channel 126 of the handle 102 . The housing inlet port 121 , established on the second end 109 of the housing 104 , enables the compressed air being provided through the inlet channel 126 , to flow into the inner cap inlet conduit 182 . The compressed air supplied through the inner cap inlet conduit 182 enables the head valve assembly 140 to operate the pneumatic fastener 100 , i.e., the firing of the piston 134 to drive the fastener into a surface or work piece.
Referring to FIGS. 11–13C , a pneumatic fastener 1100 including a dual actuation mode assembly 1102 is discussed. Those of skill in the art will appreciate that while a pneumatic fastener is discussed, the principles of the present invention may equally apply to devices utilizing a combustion event or a detonation event to secure a fastener such as a nail, a staple, or the like. The dual actuation mode assembly 1102 permits user selection of the type of actuation the fastener device is to operate (e.g. in a contact fire mode or sequential actuation mode). In contact actuation mode, a user pulls (and holds) the trigger 1104 and subsequently the contact safety assembly 1106 is depressed or pushed inwardly toward a driver housing 1108 thereby activating a pneumatic valve 1109 for releasing compressed air to drive a piston and driver into contact with a nail or fastener disposed in the driver's path of travel. Subsequent fastening events, in contact actuation mode, may be initiated by movement of the contact safety towards the driver housing such as when the pneumatic fastener 1100 has been repositioned and pressed against a workpiece. In sequential fire mode, the contact safety assembly is depressed toward the driver housing and subsequently the trigger is pulled to initiate a fastening event (the driving of a nail, staple or the like).
With particular reference to FIGS. 11 and 12 , the pneumatic fastener 1100 includes the driver housing 1108 for housing a reciprocating piston including a driver blade attached thereto for driving a fastener disposed within the path of travel of the driver blade. A contact safety assembly 1106 is adjustably mounted to the driver housing 108 in order to permit the contact safety assembly to slide towards and away from to the driver housing/the nose 1110 of the driver housing. In various embodiments, the nose may be formed as a separate structure or may be integrally formed with the main portion of the driver housing 1108 . Preferably, the contact safety assembly 1106 is biased, such as by a main spring or the like, into a remote position or away from the nose 1110 of the driver housing. Biasing the contact safety assembly away from the main portion of the fastener permits the contact safety system to function as a lock-out mechanism so that the pneumatic fastener cannot actuate. Additionally, as described above, the contact safety assembly 1106 may be utilized to initiate a fastening event (in contact mode).
The contact safety assembly 1106 includes a contact pad 1114 or foot for contacting with a workpiece. Additionally, a no-mar tip may be releasably connected to the contact pad for preventing marring of the workpiece, if the contact pad is formed of metal or includes a serrated edge for engaging a workpiece (such as in a framing nailer). For example, the contact pad 1114 may be shaped so as to translate or slide along the nose 1110 of the driver housing 1108 . In the present embodiment, the contact pad 1114 is generally shaped as a hollow cylindrical structure for sliding along the generally cylindrical nose. An intermediate linkage 1116 is coupled to the contact pad 1114 to generally position a cylindrical rod 1118 along the driver housing 1108 . For example, the movement of the intermediate linkage may permit the cylindrical rod 1118 to be variously positioned with respect to the driver housing 1108 and thus, a trigger assembly which is 1104 pivotally mounted to the driver housing 1108 and/or a handle 1120 fixedly secured to the driver housing 1108 . In the current embodiment, the intermediate linkage 1116 is secured via a fastener to the contact pad 1114 . In further embodiments, the contact pad and linkage may be unitary. In the present example, the intermediate linkage is constructed in a general L-shape to position the rod 1118 adjacent the trigger (i.e., towards the handle 1120 ). Additionally, the intermediate linkage may be constructed so as to generally conform to the driver housing, to avoid other pneumatic fastener components, i.e, avoid fastener magazine components, for aesthetic purposes or the like. Moreover, in the present instance, the intermediate linkage 1116 includes a pivot pin 1122 coupled to an end of the linakge 1116 . The pivot pin 1122 may be secured via a fastener, a friction fit or unitarily formed with the intermediate linkage. In the present embodiment, the pivot pin 1122 is received in an aperture defined in a tab which extends generally perpendicular to a leg of the generally L-shaped linkage. A portion of the pivot pin 1122 may be received in a corresponding cylindrical recess formed in the rod 1118 for at least partially supporting/pivotally connecting the rod 1118 to the intermediate linkage via the pivot pin 1122 .
Referring to FIGS. 12 and 13A , in an additional aspect of the present invention, the contact safety assembly 1106 includes an optional depth of drive or recess adjustment capability. A depth adjustment system permits a user to select to what extent the fastener is to be driven into the workpiece via selecting the extent to which the contact safety extends towards/away from the driver housing. Those of skill in the art will appreciate that a variety of factors will influence the depth to which a fastener will be driven. For example, a user may wish to leave the head of a nail above the surface of the workpiece (i.e. leave the nail proud) or may select to recess the nail head into the workpiece such that putty or filler may be filled into the recess thereby covering over the nail head (e.g., when building cabinetry or the like). In the present instance, the pivot pin 1122 includes a threaded portion 1124 or section for threading with a thumb wheel 1126 . A thumb wheel 1126 includes a corresponding aperture having a threaded portion 1130 such that the thumb wheel 1126 may travel along the threaded length of the pivot pin 1122 . The thumb wheel thereby may extend the overall length of the contact safety assembly and thus, vary the depth to which a fastener may be driven through interaction with the pneumatic valve 1109 for controlling the flow of compressed air into the driver cylinder. In the foregoing example, the thumb wheel 1126 may frictionally interconnect with a washer 1128 , disposed between the thumb wheel 1126 and a lip/flange 1134 included on the rod, via a series of rib/grooves, detents and protrusions or the like. It is to be appreciated that the rod 1118 is permitted to freely pivot (e.g., not in threaded engagement) about the pivot pin 1122 . For example, the rod 1118 and thus, the washer 1128 may be biased such as via a spring 1132 towards or into engagement with the thumb wheel 1126 . Preferably, the washer 1128 may be geometrically shaped or include protrusions such that the washer 1128 does not rotate with the thumb wheel 1126 , e.g., remains in a fixed orientation with respect to the driver housing and/or a secondary housing or contact safety housing 1136 coupled to the driver housing for at least partially encompassing at least a portion of the contact safety assembly. The series of protrusions/detents may act to retain the thumb wheel 1126 in a desired position along the pivot pin 1122 . Those of skill in the art will appreciate that the depth adjustment mechanism may be formed with a threaded projection in threaded connection with an end of a rod so as to effectively extend/retract the overall length of the rod. In the previous example, the projection is received in a recess formed in an intermediate linkage such as a tab included on an end of the linkage. For example, a rod may include a threaded portion along which a thumb wheel is in threaded engagement while the terminal portion of the rod is inserted in an aperture in an intermediate linkage.
In further embodiments, a depth of drive mechanism may be disposed between the contact pad 1114 and an intermediate linkage 1116 . Additionally, if a depth of drive or recess adjustment is not desired, the rod 1118 may extend into a recess or aperture included in a tab extending from an end of an intermediate linkage. In still further embodiments, a partially threaded pivot pin may be threaded into an aperture in the intermediate linkage and function as a pivot pin for the rod 1118 . Alternatively, a rod may include an extension which may be received in an aperture in the intermediate linkage for achieving substantially the same functionality.
With particular reference to FIGS. 12 and 13 A–C, the rod 1118 includes a first shoulder 1146 and a second shoulder 1148 . The first and the second shoulders are formed at offset distances along the length of the rod 1118 such that the orientation of a trigger 1152 and thus, a trigger lever 1142 pivotally coupled via a trigger lever pivot pin 1140 to the trigger may be varied. For example, the orientation/lateral position of the trigger lever 1142 permits selecting contact actuation mode (as illustrated in FIG. 13B ) when the first shoulder 1146 is orientated or rotated towards the trigger 1152 . While sequential actuation (as observed in FIG. 13C ) 1148 is achieved when a second shoulder which is further from the terminal end of the rod 1118 than the first shoulder 1146 is orientated or rotated towards the trigger 1152 . The particular actuation mode selected (i.e., contact actuation or sequential actuation) is determined by the change in orientation/lateral position of the trigger 1152 /trigger lever 1142 as the trigger assembly 1104 pivots about a trigger pivot pin 1156 and the selected shoulder contacts the trigger 1152 . For example, as the trigger 1152 pivots about the trigger pivot pin 1156 and contacts with the select shoulder, included on the rod, such that the shoulder acts as a stop against which the trigger 1152 is positioned. Those of skill in the art will appreciate that the interface of the rod/trigger is off-centered from the trigger pivot pin 1156 thereby varying the point (along the trigger lever 1142 ) at which the valve 1109 will contact the trigger lever 1142 due to the relative orientation/position of the trigger lever 1142 . In further embodiments, the trigger lever 1142 /trigger 1152 is biased away from the pneumatic valve 1109 by a spring 1154 or the like such that a user is required to overcome the biasing force to activate the valve 1109 . In the present embodiment, a central cylindrical projection extends beyond the first and the second shoulders 1146 and 1148 , respectively. In this instance, the trigger lever and trigger, such as the lipped portion of the trigger for engaging a shoulder, may include a curved recess to permit passage of the projection. The trigger lever 1142 may be configured to engage with the rod 1118 so as to prevent a repeated fastening event when sequential actuation or firing mode is selected. In further instances, the first and the second shoulders may be formed by milling flattened portions into a rod. Preferably, the shoulders are arranged at 180° (one hundred eighty degrees) from each other to permit sufficient engagement of the trigger and the selected shoulder.
With continued reference to FIGS. 11–13C , orientation of the rod 1118 may be achieved by rotating the rod 1118 such that a selected shoulder (the first shoulder 1146 or the second shoulder 1148 ) is aligned with a lip included on the trigger 1152 . A toggle lever or switch 1138 is coupled to the rod 1118 . In the present embodiment, the toggle switch 1138 is positioned below the trigger 1152 (with respect to the handle 1120 ) in order to permit a user to rotate the rod 1118 and thus, vary the pneumatic fastener's actuation mode by utilizing his/her forefinger and thumb. This positioning is additionally advantageous as a user may efficiently select between actuation modes without the complexity previously experienced. In the foregoing manner, a user may select between actuation modes more frequently thereby increasing efficiency over systems which require complex, time consuming manipulation. Preferably, the toggle switch defines an aperture through which the rod 1118 passes. In the present embodiment, a protrusion 1139 is formed by the toggle switch for extending into a keyway or channel extending longitudinally along at least a portion of the rod. In further embodiments, a setscrew may be utilized to accomplish this function. Those of skill in the art will appreciate a variety of mechanical interconnect systems may be implemented to achieve this function. For example, a portion of the rod may have a hexagonal cross section while a toggle switch includes a hexagonal aperture, a portion of the rod may be milled off or have a flattened portion or the like. Inclusion of a keyway or the like structure permits the toggle switch to remain in a fixed position (held in place via the contact safety housing 1136 ) with respect to the contact safety housing 1136 /the driver housing 1108 while the rod is permitted to variously position along the driver housing. Those of skill in the art will appreciate that the toggle may be fixedly secured to the rod as well so that the toggle switch travels with the rod 1118 as the contact safety assembly 1106 is manipulated generally along the driver housing.
In further examples, the toggle switch 1138 may include a detent for engaging with the contact safety cover in order to frictionally secure the toggle switch in a desired orientation (i.e. contact actuation or sequential fire). Moreover, the toggle switch may include a cam shaped outer surface for frictionally engaging the contact safety housing to retain the toggle in a desired orientation. For example, a detent and/or cam surface may be included to secure the toggle switch in sequential fire mode. Those of skill in the art will appreciate that the lever portion of the toggle may act as an indicator or indicia of the selected actuation mode to permit ready recognition. Additional symbols or markings may be included on the driver housing, the contact safety housing or provided as an adhered label to one of the housing to alert the user as to the mode selected. Preferably, the toggle switch is orientated at 90° (ninety degrees) or perpendicular to a main axis of the trigger so that the selected contact mode is readily observed. For example, the toggle lever may be orientated approximately 180° (one hundred eighty degrees) when disposed in contact actuation mode than when disposed in sequential actuation mode.
Referring now to FIGS. 14 and 15 , an additional embodiment of the present invention is illustrated wherein an adjustable handle exhaust assembly 1400 (see FIGS. 14 and 15 ) is provided. Such assembly 1400 may be coupled to a second end of a handle of a pneumatic fastener, such as a pneumatic nailer, to replace the handle exhaust 158 and handle adapter 156 as illustrated in FIG. 3 . The adjustable handle exhaust assembly 1400 may be used to input compressed air into the inlet channel 126 and may enable an operator to direct the flow of exhaust coming from the outlet channel 128 in a desired direction (e.g., away from the operator). The exhaust assembly 1400 includes a base 1402 , which includes a base plate 1404 and a cylindrical and centrally hollow protrusion 1406 protruding from and normal to the base plate 1404 . Preferably, the base plate 1404 includes an inlet opening defined therethrough and includes a first portion 1408 and a second portion 1410 . Both portions 1408 , 1410 have a circular shape and are attached to each other. The first portion 1408 is smaller than the second portion 1410 . That is, the diameter of the first portion 1408 is smaller than the diameter of the second portion 1410 so that a perimeter 1412 of the second portion 1410 is exposed for supporting a cap 1414 . The base plate 1404 includes a plurality of openings 1416 and an exhaust opening 1418 defined therethrough. A plurality of bolts 1420 may be inserted into the corresponding plurality of openings 1416 to securely couple the base 1402 to the second end 105 of the handle 102 of the pneumatic fastener 100 . The protrusion 1406 includes a threaded inner surface defining a channel for receiving a quick connector coupler 1422 and a partially threaded outer surface for receiving a compression ring 1426 . The channel defined by the threaded inner surface of the protrusion 1406 is interconnected with the inlet opening of the base plate 1404 . The cap 1414 may be made of metal, plastic, rubber, or the like. The cap 1414 includes an exit opening 1424 on its outer surface 1430 for letting the exhaust air exit the pneumatic fastener 100 . Preferably, the cap 1414 is donut-shaped with a central hole 1428 defined therein. The cap 1414 is placed on top of the base 1402 so that the protrusion 1406 protrudes from the central hole 1428 and the cap 1414 is supported by the perimeter 1412 of the second portion 1410 . Preferably, the cap 1414 is securely coupled to the base 1402 by the compression ring 1426 fastened on the partially threaded outer surface of the protrusion 1406 so that the exhaust inside the cap 1414 may exit to outside through the exit opening 1424 . The cap 1414 may be easily rotated to change the position of the exit opening 1424 whereby exhaust air exiting the exit opening 1424 can be directed in a desired direction (e.g., away from an operator).
The adjustable handle exhaust assembly 1400 may be securely coupled to the second end 105 of the handle 102 of the pneumatic fastener 100 by the bolts 1420 to replace the handle adapter 156 and the handle exhaust 158 . Preferably, the inlet opening of the base plate 1404 is interconnected with the inlet channel 126 , and the exhaust opening 1418 is interconnected with the outlet channel 102 . The quick connector coupler 1422 is connected to an air supply hose for supplying compressed air to the pneumatic fastener 100 . The compressed air flows from the air supply hose into the inlet channel 126 , via the quick connector coupler 1422 , the channel defined by the threaded inner surface of the protrusion 1406 , and the inlet opening of the base plate 1404 . The exhaust in the outlet channel 128 flows into the cap 1414 via the exhaust opening 1418 and exits the cap 1414 via the exit opening 1424 . An operator may rotate the cap 1414 easily to change the position of the exit opening 1424 so that the exhaust air exiting the exit opening 1424 is directed in a desired direction (e.g., away from the operator).
In a further exemplary embodiment directed to the present invention, a method of manufacturing a pneumatic fastener, such as the pneumatic fastener 100 , is provided. In a first step a housing including a piston assembly is provided. The housing may be of various configurations to support the functional operation of the pneumatic fastener and address aesthetic and/or ergonometric considerations. The housing is further provided with a housing inlet port and a housing exhaust port. The next step involves positioning a handle, including a handle adapter for receiving compressed air and a handle exhaust for exhausting the compressed air, to be coupled with the housing. The handle including an inlet channel coupled with the handle adapter and an outlet channel coupled with the handle exhaust. The inlet channel is further coupled with the housing inlet port and the outlet channel is further coupled with the housing exhaust port. Next, a head valve assembly including an inner cap of the present invention, is established in operational connection with the piston assembly. The inner cap further includes an inner cap inlet conduit which couples with the housing inlet port and an inner cap exhaust conduit which couples with the housing exhaust port. An outer cap is then fastened to the housing, the outer cap at least partially encompassing the head valve assembly and coupling with the inner cap.
It is contemplated that the method manufacturing may further include the establishment of a groove into the outer cap. The groove being enabled to receive an O-ring gasket and for providing a seal between the outer cap and the inner cap. In an alternative embodiment, the method of manufacturing may include the establishment of a groove in the inner cap for receiving an O-ring gasket and establishing a seal between the outer cap and the inner cap.
It is understood that the specific order or hierarchy of steps in the methods disclosed are examples of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the method can be rearranged while remaining within the scope and spirit of the present invention.
It is believed that the present invention and many of its attendant advantages will be understood by the forgoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof. Further, it is to be understood that the claims included below are merely exemplary of the present invention and are not intended to limit the scope of coverage which has been enabled by the written description.
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The present invention provides a head valve assembly for a pneumatic fastener including a piston assembly reciprocated within a cylinder assembly for driving a fastener and a housing having an end cap for at least partially enclosing the head valve assembly. The head valve assembly includes a valve piston for causing supply pressure to be ported to the piston assembly for moving the piston assembly within the cylinder assembly from a non-actuated position to an actuated position for driving the fastener. Further, an inner cap is disposed within the end cap around the valve piston. The inner cap includes an inlet port for porting pressure to the valve piston. In addition, a main seal is coupled to the valve piston for sealing the cylinder assembly from supply pressure while pressure is ported to the valve piston by the inner cap for holding the piston assembly in the non-actuated position. The main seal seals pressure ported to the valve piston by the inner cap from supply pressure ported to the piston assembly.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 60/500,259, filed Sep. 5, 2003, which is incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention pertains to polymer beads for removing arsenic from aqueous fluids such as groundwater.
BACKGROUND OF THE INVENTION
[0003] Arsenic is a toxic and ubiquitous metalloid element that can be found in groundwaters around the world at levels well above the maximum containment level of 10 μg/L recommended by the World Health Organization (WHO). Arsenic poses a serious threat to millions of people worldwide, and geogenic (natural) contamination has been reported in many countries, including countries having large populations such as India and China. In the U.S., the Environmental Protection Agency (EPA) has recently decreased the limit of arsenic in drinking water from 50 μg/L to 10 μg/L, and all systems for treating drinking water must comply with the new standard by January 2006.
[0004] Arsenic occurs mainly as arsenate As(V) (having a +5 oxidation state) and arsenite As(III) (having a +3 oxidation state) in groundwaters. Different compounds can be formed with arsenic in groundwater depending on the arsenic oxidation state. The distribution of As(III)/As(V) varies significantly in groundwater. As(III) can represent in the range of about 30% to about 98% of the total arsenic in groundwaters.
[0005] Conventional systems for removing arsenic have suffered from a number of drawbacks such as low efficiency and/or specificity. For example, some ion exchange systems have less affinity for As(V), particularly when other ions (e.g., sulfate, chloride, and/or phosphate ions) are present in the fluid being treated. Typically, As(III) is pre-oxidized to As(V) so that the oxidized form can subsequently be removed.
[0006] Alternatively, or additionally, some ion exchange systems require regeneration after a relatively short period of time. For example, Clifford has estimated bed volumes for 10 percent and 50 percent breakthrough of influent arsenic (FIG. 3-15, J. AWWA, 86:4:10 (1995)), showing the regeneration frequencies for ion exchange columns as a function of influent sulfate concentration. Regeneration can involve using brine solution, and this creates another arsenic-containing waste stream that must also be processed. While brine solutions can be re-used, the resultant arsenic concentration can exceed the technology based local limits (TBLL), and the spent solution must be treated and/or disposed of.
[0007] The present invention provides for ameliorating at least some of the disadvantages of the prior art. These and other advantages of the present invention will be apparent from the description as set forth below.
BRIEF SUMMARY OF THE INVENTION
[0008] An embodiment of the invention provides a chelate-forming material comprising a crosslinked polymeric bead having bound chelate-forming groups and a volume capacity of about 1.5 mmol/mL or less, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine, and have the capability of forming a chelate with As(V) and/or compounds thereof.
[0009] Alternatively, or additionally, another embodiment of the invention provides a chelate-forming material comprising a crosslinked polymeric bead having bound chelate-forming groups and a nitrogen content of about 2.4 mmol/g or more, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine, and have the capability of forming a chelate with As(V) and/or compounds thereof.
[0010] In some embodiments, the protonated N-methyl-D-glucamine is in chloride form, or in sulfate form.
[0011] An embodiment of a method for treating an arsenic-containing aqueous fluid according to the invention comprises contacting an As(V)-containing fluid with crosslinked polymeric beads each having bound chelate-forming groups and a volume capacity of about 1.5 mmol/mL or less, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine and have the capability of forming a chelate with arsenate(V) and/or compounds thereof, forming the chelate with As(V) and/or a compound thereof, and separating the chelated As(V) and/or compound thereof from the fluid.
[0012] Yet another embodiment of a method for treating an arsenic-containing aqueous fluid according to the invention comprises contacting an As(V)-containing fluid with crosslinked polymeric beads each having bound chelate-forming groups and a nitrogen content of about 2.4 mmol/g or more, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine and have the capability of forming a chelate with arsenic(V) and/or compounds thereof, forming the chelate with As(V) and/or a compound thereof, and separating the chelated As(V) and/or compound thereof from the fluid.
[0013] In another embodiment, a process for preparing a chelate-forming crosslinked polymeric bead having a volume capacity of about 1.5 mmol/mL or less and/or a nitrogen content of about 2.4 mmol/g or more, wherein the bead is comprised of a crosslinked polymer bound to chelate-forming groups, comprises obtaining a crosslinked polymeric bead having functional groups, reacting the functional groups with N-methyl-D-glucamine, and producing a protonated N-methyl-D-glucamine.
DETAILED DESCRIPTION OF THE INVENTION
[0014] An embodiment of the invention provides a crosslinked polymeric bead having bound chelate-forming groups and a volume capacity of about 1.5 mmol/mL or less, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine, and have the capability of forming a chelate with As(V) and/or compounds thereof. In a preferred embodiment, the bead has a volume capacity of about 1.3 mmol/mL or less.
[0015] Alternatively, or additionally, another embodiment of the invention provides a crosslinked polymeric bead having bound chelate-forming groups and a nitrogen content by dry weight basis of about 2.4 mmol/g or more, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine, and have the capability of forming a chelate with As(V) and/or compounds thereof. In a preferred embodiment, the bead has a nitrogen content by dry weight basis of about 2.5 mmol/g or more.
[0016] In some embodiments of crosslinked beads according to the invention, the protonated N-methyl-D-glucamine is in chloride form, or sulfate form.
[0017] In an embodiment, the crosslinked polymeric bead comprises poly(vinylbenzylchloride) or chloromethylated styrene wherein the chelate-forming groups are bound to at least a portion of the —CH 2 groups of the benzyl moieties. In another embodiment, the crosslinked polymeric bead comprises poly(glycidyl methacrylate) wherein the chelate forming groups are bound to at least a portion of the glycidal groups of the acrylate moieties.
[0018] In some embodiments, the crosslinked polymeric bead comprises a polymerized bi-, tri-, or tetra-functional monomer, or any combination thereof, to provide the crosslinks. The bi-, tri-, or tetra-functional monomer can be selected from the group consisting of ethylene glycol diacrylate, di(ethylene glycol) diacrylate, tetra(ethylene glycol) diacrylate, ethylene glycol dimethacrylate, di(ethylene glycol) dimethacrylate, tri(ethylene glycol) dimethacrylate, butanediol diacrylate, hexanediol diacrylate, N,N-methylenebisacrylamide, N,N-(1,2-dihydroxyethylene) bisacrylamide, and divinylbenzene, or any combination thereof.
[0019] A system for treating arsenic-containing aqueous fluid according to an embodiment of the invention comprises a bed comprising crosslinked polymeric beads each bead having bound chelate-forming groups, and a volume capacity of about 1.5 mmol/mL or less and/or a nitrogen content by dry weight basis of about 2.4 mmol/g, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine, and have the capability of forming a chelate with As(V) and/or compounds thereof.
[0020] An embodiment of a method for treating an arsenic-containing aqueous fluid according to the invention comprises contacting an As(V)-containing fluid with crosslinked polymeric beads, each bead having bound chelate-forming groups, and a volume capacity of about 1.5 mmol/mL or less and/or a nitrogen content by dry weight basis of about 2.4 mmol/g or more, wherein the chelate-forming groups comprise protonated N-methyl-D-glucamine, and having the capability of forming a chelate with arsenic(V) and/or compounds thereof, forming the chelate with As(V) and/or a compound thereof, and separating the chelated As(V) or compound thereof from the fluid. A preferred embodiment of the invention comprises separating As(V) from groundwater.
[0021] In another embodiment, a process for preparing a chelate-forming crosslinked polymeric bead having a volume capacity of about 1.5 mmol/mL or less and/or a nitrogen content of about 2.4 mmol/g or more, wherein the bead is comprised of a crosslinked polymer bound to chelate-forming groups, comprises obtaining a crosslinked polymeric bead having functional groups, reacting the functional groups with N-methyl-D-glucamine, and producing a protonated N-methyl-D-glucamine. In some embodiment of the process, the crosslinked polymeric bead having functional groups comprises a poly(vinylbenzylchloride) bead, a chloromethylated polystyrene bead, or a poly(glycidyl methacrylate) bead. The functional groups on the crosslinked polymer bead can be haloalkyl groups or epoxy groups.
[0022] The present invention is preferably used to treat source water, such as municipal drinking water, water from natural sources such as lakes, rivers, reservoirs, surface water, groundwater and storm water runoff, or industrial source water, or wastewater, such as industrial wastewater or municipal wastewater. Source water may also include treated wastewater which has, for example, been purified after industrial use.
[0023] Embodiments of the invention can also be used to treat As(V)-containing brine.
[0024] Advantageously, in view of the affinity, selectivity, and sorption capacities of the beads according to the invention, beds including the beads can be used to treat greater volumes of water and/or treat the water for longer periods of time, before replacement and/or regeneration, than beds including conventionally available beads. Additionally, since the beds can be used for longer periods of time before regeneration, less regeneration treatment fluid is needed for a given period of time and/or there is less process downtime for the beds, compared to that for beds including conventionally available beads.
[0025] The invention provides for the removal of As(V) from influent aqueous fluids, typically source water having a pH in the range of from about 1 to about 11, preferably, having a pH in the range of from about 4 to about 6.5. As used herein, removal of As(V) includes removal of the arsenic-containing negatively charged compounds typically formed in natural waters at a pH in the range of 2 to 11, i.e., H 2 AsO 4 −1 and HAsO 4 −2 . In some embodiments, the invention provides for the removal of the arsenic-containing uncharged compound, H 3 AsO 2 , formed in aqueous fluids at a pH of about 1 to about 1.5.
[0026] Embodiments of the invention can efficiently remove As(V) from groundwater having a sulfate concentration of greater than 120 mg/T, e.g., up to about 800 mg/L, or more and/or can efficiently remove As(V) from groundwater having a phosphate concentration of up to about 400 mg/L, or more. Alternatively, or additionally, embodiments of the invention can remove As(V) from aqueous fluids in the presence of 1M NaCl.
[0027] The chelate-forming groups of the present invention comprise protonated N-methyl-D-glucamine represented by formula (I):
[0000]
[0028] The chelate-forming group, N-methyl-D-glucamine (NMDG), can be quantified by a variety of techniques, including elemental analysis. Elemental analysis is performed to determine the amount of nitrogen, or equivalents of nitrogen, present in the chelate-forming group. Since the chelate-forming group is the sole group that contains nitrogen, the equivalents of nitrogen are directly related to the equivalents of the chelate-forming group present on the bead. This can be further defined as “theoretical specific capacity”, (IUPAC Compendium of Analytical Nomenclature, section 9.2.5.4, 1997, 3rd ed.) which is the amount (mmol) of ionogenic group per mass (g) of dry ion exchanger.
[0029] Illustrative elemental analytical techniques for determining the nitrogen content of beads according to the invention are ASTM D 5373 (2002) “Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Laboratory Samples of Coal and Coke” and ASTM D 5291 (2003) “Test Method for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants.”
[0030] For example, when analyzed in accordance with ASTM D 5373, crosslinked beads according to embodiments of the invention, comprising the protonated N-methyl-D-glucamine, have a nitrogen content, or a dry weight basis, of 2.35 mmol/g or more. Typically, when analyzed in accordance with ASTM D 5373, crosslinked beads according to embodiments of the invention have a nitrogen content, on a dry weight basis, of 2.46 mmol/g or more.
[0031] In accordance with some embodiments of the invention, the crosslinked bead comprising the protonated N-methyl-D-glucamine, has a nitrogen content, on a dry weight basis, of about 2.4 mmol/g or more, preferably, a nitrogen content of about 2.5 mmol/g or more, more preferably, a nitrogen content of about 2.6 mmol/g or more, and in some embodiments, a nitrogen content of about 2.7 mmol/g or more.
[0032] In accordance with the invention, the bead (or particle) is preferably a non-porous bead, although it may have pores having diameters of 50 Angstroms or less, e.g., micropores. The bead is crosslinked. Preferred crosslinked polymeric beads comprise poly(vinylbenzylchloride) copolymer beads and poly(glycidyl methacrylate) copolymer beads. Other embodiments include, for example, crosslinked chloromethylated polystyrene copolymer beads, and crosslinked polymer beads functionalized with amine reactive chemistries such as epichlorohydrin and azlactone.
[0033] In some embodiments, the crosslinked polymeric bead comprises a polymerized bi-, tri-, or tetra-functional monomer, or any combination thereof, to provide the crosslinks. The bi-, tri-, or tetra-functional monomer can be selected from the group consisting of ethylene glycol diacrylate, di(ethylene glycol) diacrylate, tetra(ethylene glycol) diacrylate, ethylene glycol dimethacrylate, di(ethylene glycol) dimethacrylate, tri(ethylene glycol) dimethacrylate, butanediol diacrylate, hexanediol diacrylate, N,N-methylenebisacrylamide, N,N-(1,2-dihydroxyethylene) bisacrylamide, and divinylbenzene (DVB), or any combination thereof.
[0034] A variety of crosslinkers can be used in preparing beads according to the invention. Preferred crosslinking agents include compounds with two or more groups. Exemplary crosslinkers include ethylene glycol di(meth)acrylate (EGDMA), ethylene glycol diacrylate, di(ethylene glycol) diacrylate, tetra(ethylene glycol) diacrylate, ethylene glycol dimethacrylate, di(ethylene glycol) dimethacrylate, tri(ethylene glycol) dimethacrylate; butanediol diacrylate, hexanediol diacrylate, methylenebisacrylamide, N,N methylenebisacrylamide, N,N-(1,2-dihydroxyethylene)bisacrylamide), and divinylbenzene (DVB).
[0035] The degree of crosslinking is preferably about 7% or less, more preferably, about 5% or less, and in some embodiments, about 3% or less. The desired range can be varied depending on, for example, the hydrophilicity of the backbone polymer and the structure of the crosslinking agent. Illustratively, the degree of crosslinking can be in the range of from about 2% to about 7% (e.g., wherein the bead includes a more hydrophilic backbone polymer such as, for example, poly(glycidyl methacrylate)), or from about 2% to about 5% (e.g., wherein the bead includes a more hydrophobic backbone polymer, such as, for example, poly(vinylbenzylchloride) or chloromethylated polystyrene).
[0036] Without being limited to any particular mechanism(s), it is believed the polymer chains (e.g., polystyrene backbone) forming the bead are flexible, and this flexibility, and the level of crosslinking are important, so that the lower level of crosslinking (about 7% or less) allows increased swelling of the bead, allowing more reactive groups to bind NMDG to the bead, providing more available surface area allowing a greater amount of the NMDG to be bound to the bead, and allowing more of the protonated NMDG to be accessed by the As(V) in the fluid to be treated. As a result, more of the protonated NMDG is available for selectively forming a chelate with the As(V) and/or compounds thereof.
[0037] In some embodiments of the invention, the crosslinked polymeric bead having bound chelate-forming groups has volume capacity of about 1.5 mmol/mL or less, preferably, about 1.3 or less. In some embodiments, the volume capacity is in the range of from about 1.5 mmol/mL to about 1.1 mmol/mL. Without being bound to any particular mechanism, it is believed the volume capacity can be generally correlated with the degree of crosslinking.
[0038] As used herein, the volume capacity is, as defined in IUPAC Compendium of Analytical Nomenclature, section 9.2.5.4, 1997, 3rd ed., the amount (mmol) of ionogenic group per volume (cm 3 ) of swollen ion exchanger. The ionic form of the ion exchanger and the medium should be stated. In accordance with the present invention, the ionic form of the ion exchanger is the protonated amine, and the medium is water.
[0039] In an embodiment of the invention, the swelling ratio is about 1.5 or more, preferably about 2.3 or more. Typically, the swelling ratio is in the range of from about 1.5 to about 2.5, and in some embodiments, can be greater than about 2.5.
[0040] As used herein, the swelling ratio refers to the increase in volume when comparing the volume of the beads after a specified time in water to the volume of vacuum dried beads. The specific swelling ratios referenced in the Examples section herein were determined using 2 mL of vacuum dried beads that were placed in a 10 mL cylinder of water, wherein the volume was determined after 19 hours.
[0041] In accordance with the invention, the process for preparing a chelate-forming crosslinked polymeric bead comprises obtaining a crosslinked polymeric bead having funnctional groups, and reacting these functional groups with NMDG to bind the NMDG to the crosslinked bead. Preferred functional groups are haloalkyl groups, i.e., chloromethyl, or epoxy groups. In those embodiments wherein the crosslinked polymeric bead comprises poly(vinylbenzylchloride) or chloromethylated polystyrene, the reactive functional groups are chloromethyl groups, and the NMDG becomes bonded to the —CH 2 groups of the benzyl moieties via a nucleophilic substitution reaction at the chloromethyl group. In those embodiments wherein the crosslinked polymeric bead comprises poly(glycidyl methacrylate) or epichlorohydrin, the reactive functional groups are epoxy groups, and the N-methyl-D-glucamine becomes bonded to the glycidal groups of the acrylate moieties via a ring-opening reaction of an epoxy group.
[0042] The resulting bead is conditioned with a dilute acidic solution such as, for example, HCl or H 2 SO 4 , to produce a protonated amine moiety on the chelate-forming group. For example, the bead can be conditioned with HCl to provide protonated N-methyl-D-glucamine in chloride form, or conditioned with H 2 SO 4 to provide protonated N-methyl-D-glucamine in sulfate form. If desired, one form can be exchanged to the other, e.g., the sulfate form can be exchanged to the chloride form, or the chloride form can be exchanged to the sulfate form. For example, the chloride form can be soaked in water, and subsequently conditioned with NaOH, water, H 2 SO 4 , and water.
[0043] The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope.
EXAMPLE 1
[0044] This example describes of the preparation of chelate-forming beads according to an embodiment of the invention.
[0045] 2.0 grams of crosslinked beads comprising polymerized vinylbenzylchloride (VBC) and divinylbenzene (DVB) (crosslink level 2 wt. %) were swelled in 50 ml dioxane and transferred into a 250 mL round bottom flask equipped with a condenser and an overhead stirrer. 20 g of NMDG was added to 10 mL of water and 100 mL 1,4-dioxane. The mixture was heated at reflux for 17 hours. After washing, the beads were conditioned with 1 L each of water, 4% aq. NaOH, 4% aq. HCl, and water.
EXAMPLE 2
[0046] This example describes of the preparation of chelate-forming beads according to another embodiment of the invention.
[0047] 1.5 grams of crosslinked beads comprising polymerized glycidyl methacrylate (GMA) and DVB (crosslink level 8 wt. %) were swelled in 50 ml dioxane and transferred into a 250 mL round bottom flask equipped with a condenser and an overhead stirrer. 10 g of NMDG was added to 10 mL of water and 100 mL 1,4-dioxane. The mixture was heated at reflux for 3 hours. After washing, the beads were conditioned with 1 L each of water, 4% aq. NaOH, 4% aq. HCl, and water.
EXAMPLE 3
[0048] This example demonstrates the swelling ratio of chelate-forming beads according to an embodiment of the invention.
[0049] 2 mL of the beads described in Example 1 are vacuum dried and placed in a 10 mL cylinder filled with water. After 19 hours, the volume of the beads is 4.6 mL, and thus, the swelling ratio is 2.3.
EXAMPLE 4
[0050] This example demonstrates the volume capacity of chelate-forming beads according to an embodiment of the invention.
[0051] Beads are prepared as described in Example 1. Elemental analysis is performed, and combined with the swelling ratio determined as in Example 3, it is determined the beads have a volume capacity of 1.19 mmol Nitrogen/mL.
EXAMPLE 5
[0052] This example demonstrates the selective formation of chelates with As(V) of chelate-forming beads according to an embodiment of the invention as compared to commercially available beads and fibers including NMDG, particularly in the presence of sulfate.
[0053] Polymerized VBC-DVB (crosslink level 2 wt. %) beads including NMDG are prepared as described in Example 1. Additionally, the following commercially available beads including NMDG are obtained: Diaion CRB-02 (Mitsubishi Chemical), Purolite S-108 (Purolite Co.), and Amberlite IRA-743 (Rohm and Haas). The following commercially available cotton fibers including NMDG are also obtained: GCP, GRY, and GRY-L (Chelest Corp.). Each set of beads and fibers is placed in contact with As(V) solutions as described below.
[0054] The beads and fibers are all conditioned with 1 L each of water, 4% NaOH, water, 4% HCl and water, and vacuum dried at 70° C. Nitrogen elemental analysis is performed on each set of beads and fibers, and beads and fibers containing 0.3 meq of nitrogen are placed in contact with the As(V) solutions.
[0055] Two sets of As(V) solutions are prepared using sodium hydrogen arsenate Na 2 HAsO 4 , 7H 2 O (AlfaAesar). The solutions are 20 mL As(V) 100 ppm. One set of As(V) solutions includes a concentration of 560 mg/L SO 4 2− (pH 6.0). The set of As(V) solutions without SO 4 2− has a pH of 5.8.
[0056] Each set of As(V) solutions is placed in contact with a separate set of beads and fibers, i.e., beads prepared in accordance with Example 1 are contacted with the solutions, and each of the commercially available beads and fibers are contacted with the solutions. In placing the As(V) solution in contact with the beads and fibers, 20 mL of the solution is placed in a Nalgene 40 mL bottle containing the beds or fibers, on a shaker. The total contact time is 3 days.
[0057] Arsenate concentrations are analyzed by the molybdenum blue method (Charlot) using a spectrophotometer Spectronic 21 D (Milton Roy) equipped with ½″ test tube. For lower concentrations, solutions are analyzed by ICP-MS (Hewlet Packard)
[0058] All of the beads and the GRY and GRY-L fibers remove more than 99% (the GCP fibers remove 98.6%) of the arsenic present in solution from the solution without SO 4 2− . CRB-02 achieves a residual As(V) concentration of 80 ppb, S-108 achieves a residual As(V) concentration of 890 ppb, IRA-743 achieves a residual concentration of 300 ppb, and the VBC-DVB beads prepared in accordance with Example 1 remove 99.9% of the arsenic with a residual As(V) concentration of less than 50 ppb.
[0059] The equilibrium solution concentrations (mg/L) and sorption capacities (mg/g) at equilibrium solution concentration are, respectively: 0.03 mg/L and 16.4 mg/g (VBC-2% DVB bead), 0.30 mg/L and 14.7 mg/g (IRA-741), 0.08 mg/L and 14.9 mg/g (CRB-02), 0.89 mg/L and 14.8 mg/g (S-108), 1.42 mg/L and 8.88 mg/g (GCP), 0.04 mg/L and 6.92 mg/g (GRY), and 0.04 mg/L and 7.45 mg/g (GRY-L).
[0060] With respect to the As(V) solution including a concentration of 560 mg/L SO 4 −2 , the efficiency of removal of As(V) drops for the commercially available beads when compared to the solution without SO 4 2− , i.e., CRB-02 drops from 99.9% to 90.3%, S-108 drops from 99.1% to 77.9%, and IRA-743 drops from 99.7% to 79.4%. The efficiency of removal for each of the GCP, GRY, and GRY-L fibers is, respectively, 98.8%, 97.8%, and 98.9%.
[0061] The equilibrium solution concentrations (mg/L) and sorption capacities (mg/g) at equilibrium solution concentration are, respectively: 20.7 mg/L and 13.3 mg/g (IRA-741), 9.70 mg/L and 13.7 mg/g (CRB-02), 22.2 mg/L and 11.8 mg/g (S-108), 1.21 mg/L and 9.06 mg/g (GCP), 2.22 mg/L and 6.87 mg/g (GRY), and 1.04 mg/L and 7.46 mg/g (GRY-L).
[0062] The VBC-2% DVB beads prepared in accordance with Example 1 essentially maintain the removal efficiency and sorption capacity, in that the removal efficiency is 99.4%, and the sorption capacity (at an equilibrium solution concentration of 0.63 mg/L) is 16.6 mg/g.
EXAMPLE 6
[0063] This example describes of the preparation of chelate-forming beads according to another embodiment of the invention, and the selective formation of chelates with As(V) of the chelate-forming beads.
[0064] 2.0 grams of beads comprising polymerized chloromethylated polystyrene DVB beads (Sybron Chemicals Inc.) (crosslink level 3 wt. %) were swelled in 20 ml dioxane and transferred into a 250 mL round bottom flask equipped with a condenser and an overhead stirrer. 20 g of NMDG was added to 10 mL of water and 100 mL 1,4-dioxane. The mixture was heated at reflux for 17 hours. After washing, the beads were conditioned with 1 L each of water, 4% aq. NaOH, 4% aq. HCl and water.
[0065] Nitrogen elemental analysis is performed in accordance with ASTM D 5373 and beads containing 0.3 meq of nitrogen are placed in contact with the As(V) solutions as described in Example 5.
[0066] The beads remove 99.9% of the As(V) present in solution from the solution without SO 4 2− , and achieve a residual As(V) concentration of 65 ppb. The beads remove 96.3% of the As(V) present in solution from the solution with a concentration of 560 mg/L SO 4 2− .
EXAMPLE 7
[0067] This example describes of the preparation of chelate-forming beads according to another embodiment of the invention.
[0068] 2.0 grams of beads comprising polymerized VBC and EGDMA (crosslink level 2 wt. %) are swelled and placed in a 250 mL round bottom flask equipped with a condenser and an overhead stirrer. 20 g of NMDG (Arcos Organics) is added to 10 mL of water and 100 mL of dioxane. The mixture is heated at reflux for 17 hours. After washing, the beads are conditioned with 1 L each of water, 1N NaOH, water, 1N HCl, and water, then vacuum dried at 70° C. for 17 hours and characterized by FTIR and nitrogen elemental analysis.
EXAMPLE 8
[0069] This example demonstrates the selective formation of chelates with As(V) using crosslinked beads having the sulfate form of protonated NMDG according to another embodiment of the invention.
[0070] Beads are prepared as described in Example 7 to provide beads having the chloride form of protonated NMDG. The beads are treated to exchange the chloride form for the sulfate form by soaking the beads in 1 L of water for 2 hours, followed by conditioning with 1 L of 1N NaOH, 1 L of water, 1 L of 1 N H 2 SO 4 , and 1 L of water.
[0071] Six ml of the beads are arranged in a 1 cm diameter 10 cm long minicolumn, and, in accordance with the ANSI/NSF 53 protocol, challenge water containing 50 ppb As(V), 50 ppm sulfate, 40 ppb phosphate, 2 ppm nitrate, 71 ppm chloride, and 1 ppm fluoride ions is continuously passed through the column. The As(V) concentration in the effluent is consistently reduced below 10 ppb and no breakthrough is observed after 1000 bed volumes.
EXAMPLE 9
[0072] This example describes of the selective formation of chelates with As(V) of chelate-forming beads according to an embodiment of the present invention in the presence of different concentrations of chloride or sulfate ions.
[0073] 1.6 grams of crosslinked beads comprising VBC and polymerized DVB (crosslink level 2 wt. %) are swelled and placed in a 250 mL round bottom flask equipped with a condenser and overhead stirrer. 20 g of NMDG (Arcos Organics) is added to 10 mL of water, and 100 mL of dioxane. The mixture is refluxed for 17 hours. After washing, the beads are conditioned with 1 L each of water, 1M NaOH, water, 1 M HCl, and water, then vacuum dried at 70° C. for 17 hours and characterized by FTIR and nitrogen elemental analysis.
[0074] Additionally, Amberlite IRA-900 beads (Rohm and Haas) are obtained and conditioned and dried as set forth above.
[0075] Six sets of As(V) containing solutions are prepared, each containing 100 mg As(V)/L in 0.01, 0.10, and 1.0 M of either Cl − or SO 4 2− , respectively. 100 mg of each type of dry beads is contacted with 20 mL As(V), 100 mg/L, pH 6.5, at each concentration of either sulfate or chloride ions.
[0076] Arsenate is analyzed by the molybdenum blue method using a Spectronic 21D spectrophotometer. At lower concentrations, and in the presence of phosphate, solutions are analyzed by ICP-MS (Hewlett-Packard 4500 series).
[0077] At 0.10 M of either Cl − or SO 4 2− , the beads prepared according to an embodiment of the invention sorb 96% and 83% of the arsenate, respectively, while IRA-900 sorbs less than 10% As(V) in the presence of either competing ion. The trends are identical at all three concentrations. Sulfate ions interfere more than chloride ions. However, with respect to 0.01 M solutions, the effect is much more pronounced with IRA-900 than with the beads prepared according to an embodiment of the invention.
EXAMPLE 10
[0078] This example describes the preparation of chelate-forming beads according to other embodiments of the invention, and the selective formation of chelates with As(V) of the chelate-forming beads as compared to commercially available resins including NMDG, particularly in the presence of sulfate.
[0079] 1.6 grams of crosslinked beads comprising VBC and polymerized DVB (crosslink levels 2 wt. %, 5 wt. %, 8 wt. %, and 12 wt. %) are swelled and placed in a 250 mL round bottom flask equipped with a condenser and overhead stirrer. 20 g of NMDG (Arcos Organics) is added to 10 mL of water, and 100 mL of dioxane. The mixture is heated at reflux for 17 hours. After washing, the beads are conditioned with 1 L each of water, 1M NaOH, water, 1 M HCl, and water, then vacuum dried at 70° C. for 17 hours and characterized by FTIR and nitrogen elemental analysis.
[0080] 1.6 grams of 3 wt. % DVB-crosslinked chloromethylated polystyrene beads including NMDG are also prepared as described above.
[0081] Additionally, the following commercially available beads including NMDG are obtained as described in Example 5: Purolite S-108, Diaion CRB-02, and Amberlite IRA-743.
[0082] Beads containing 0.3 mmol of nitrogen are placed in contact with the As(V) solutions for 21 hours.
[0083] Two sets of As(V) solutions are prepared. One solution is 20 mL As(V), 100 mg/L, pH 6. The other solution is 20 mL As(V), 100 mg/L+560 mg/L SO 4 2− , pH 6.
[0084] Each set of As(V) solutions is placed in contact with a separate set of beads, i.e. NMDG beads prepared as described above at each crosslink density are contacted with the solutions, CRB-02 beads are contacted with the solutions, S-108 beads are contacted with the solutions, and IRA-743 beads are contacted with the solutions.
[0085] Arsenate is analyzed by the molybdenum blue method using a Spectronic 21D spectrophotometer. At lower concentrations, solutions are analyzed by ICP-MS (Hewlett-Packard 4500 series).
[0086] With the exception of the 12 wt. % DVB-VBC NMDG beads, all of the beads remove more than 99% of the arsenate present in solution from the solution without SO 4 2− . The 12% DVB-VBC NMDG beads remove about 95% of the arsenate present in solution from the solution without SO 4 2− .
[0087] With respect to the As(V) solution including a concentration of 560 mg/L SO 4 −2 , the efficiency of removal of As(V) drops for the commercially available beads when compared to the solution without SO 4 2− , i.e., CRB-02 drops to about 73%, S-108 drops to about 50%, and IRA-743 drops to about 55%.
[0088] With the exception of the 8 wt. % and 12 wt. % DVB-VBC NMDG beads, all of the other prepared non-commercially available crosslinked NMDG beads (having 2%, 3%, and 5% crosslinking levels) remove over 90% of the arsenate present in solution from the solution with SO 4 2− . The 8 wt. % and 12 wt. % DVB-VBC NMDG beads remove about 55% and about 40%, respectively, of the arsenate present in solution from the solution with SO 4 2− .
EXAMPLE 11
[0089] This example describes of the higher nitrogen content by dry weight basis of the chelate-forming beads according to other embodiments of the invention as compared to three commercially available products.
[0090] Crosslinked beads comprising polymerized VBC and DVB (crosslink levels 2 wt. %, 5 wt. %, 8 wt. %, and 12 wt. %) including NMDG are prepared as described in Example 10. Crosslinked beads comprising polymerized VBC crosslinked with EGDMA (crosslink levels 2% and 4%) including NMDG are prepared as described in Example 7.
[0091] The following commercially available beads including NMDG are also obtained: Amberlite IRA-743, Diaion CRB-02, and Purolite S-108.
[0092] Nitrogen elemental analysis of the beads is performed in accordance with ASTM D 5373.
[0093] The results are as follows:
[0000]
Bead including NMDG
Nitrogen content (mmol/g)
2% DVB gel polyVBC
2.62
3% DVB gel chloromethylated
2.68
polystyrene
5% DVB macroporous polyVBC
2.58
8% DVB macroporous polyVBC
2.21
12% DVB macroporous polyVBC
1.81
2% EGDMA polyVBC
2.69
4% EGDMA polyVBC
2.58
IRA-743
2.24
CRB-02
2.26
S-108
2.27
[0094] The table shows that, when analyzed in accordance with ASTM D 5373, prepared beads having less than 8% crosslinking have a nitrogen content by dry weight basis of greater than 2.35 mmol/g, and commercially available beads have a nitrogen content by dry weight basis of 2.27 mmol/g or less.
[0095] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0096] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value failing within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0097] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
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Crosslinked polymeric beads for removing arsenate from water, as well as methods for preparing and using the beads are disclosed.
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FIELD OF THE INVENTION
[0001] This invention relates to patient care apparatus, and particularly to apparatus for caring for infants. More particularly, the present disclosure relates to cribs and bouncers for caring for infants. Most particular the present disclosure relates to cribs and bouncers for caring for premature infants, and special needs infants.
BACKGROUND OF THE INVENTION
[0002] Premature born or ill infant is spending significant time after his or her birth in sophisticated patient care apparatus in a hospital. Patient care apparatus, such as incubators, are used to provide a special, tightly controlled environment for premature infants in the hospital. An incubator for an infant provides conditions for special care and protects the infant from infections. The U.S. Pat. No. 3,610,716 describes an isolator crib bank having a module for filtering air delivered to ganged cribs for neonates. This invention teaches an isolator crib bank for use in the hospital. The isolator crib bank is bulky, energy consuming and can be used only in hospital environment. After releasing from the hospital premature infants may require special care because they are very sensitive to infections and very often experienced serious, life threatening complications after contracting respiratory infections.
[0003] Conventional apparatus for caring for infants after releasing from the hospital provide support for infant body, and means for preventing an infant, from falling out. Among these conventional apparatuses for caring for infants are different types of cribs and bouncers. There are number of apparatus for caring for infants, such as cribs, and bouncers which provide safe and comfortable positioning of the infant. The U.S. Pat. No. 5,787,534 discloses a safety pad or mattress such as for use in a crib, which prevents sudden infant death syndrome by ensuring an oxygenated breathing space for the infant. According to this patent, an embedded air tube is interconnected with an air pump which circulates fresh, i.e., oxygenated, air in the breathing space of the infant. While the U.S. Pat. No. 5,787,534 teaches a pad or a mattress which prevents sudden infant dead syndrome, it does not teach a prevention of an infant from disease contracted from airborne infections.
[0004] The U.S. Pat. No. 7,404,219 discloses portable infant bed with side wall ventilation. The side wall has a vent positioned at a level near the sleeping surface, the vent permitting air to pass freely through the side wall. While the U.S. Pat. No. 7,404,219 teaches an infant bed with improved passage of air across the child sleeping surface, it does not teach an infant bed protecting an infant from airborne infections.
[0005] These conventional apparatus for caring for infants, where the infant spends most of his or her time, lack of means for protection of the infant from contracting respiratory infections.
[0006] There are a number of means which reduce risk of contracting of airborne infection in adults. Among these means are different types of masks and protective gear. The U.S. Pat. Nos. 6,941,949; 6,945,249; 4,488,547 disclosed the examples of face masks.
[0007] The disadvantage of known protective masks and protective gear is that they cannot be used in infants because they have resistance to breathing, create uncomfortable feeling, sense of isolation from the environment, and could be dangerous to infants.
[0008] None of the above inventions and patents, taken either singly or in combination, is seen to teach the apparatus for caring for infants preventing from contracting respiratory infections.
[0009] Accordingly, there is presently a need for an apparatus for caring for infants that reduces or eliminates some of the risks associated with respiratory infections.
[0010] The present invention has been developed in response to the problems and needs in the present state of art that have not yet been solved by currently available apparatus for caring for infants. Accordingly, the present invention has been developed to provide an apparatus for caring for infants protecting an infant from airborne infections.
SUMMARY OF THE INVENTION
[0011] An apparatus for caring for infants which is used for caring for the infant at home or during visits of doctor's offices, public places or private homes.
[0012] The apparatus includes an infant body support structure, with a bottom, high ends, side guard means, air nozzles, a chamber, a fluid communication means, fan means, an ultraviolet light emitter, and a filter means in said chamber to provide filtering the air through said filter means. The apparatus also includes an energizing means, to provide the energy supply for said ultraviolet light emitter and for said fan means.
[0013] The air nozzles preferably mounted on the infant body support structure. The air nozzles located at the end of the infant body support structure supporting the head of the infant, above the head of the infant. The air nozzles have at least one nozzle. The air nozzles provide an air flow of disinfected air. The air flow of disinfected air protects the infant from airborne infections.
[0014] The chamber is mounted preferably under the bottom of the infant body support structure. The chamber has an air inlet at one end and an air outlet at the opposite end.
[0015] The fluid communication means preferably has at least one air duct. The fluid communication means connected with the air outlet of the chamber at one end and with the air nozzles at another end.
[0016] The fan means preferably disposed at the chamber to generate the air flow through the chamber, fluid communication means, and the air nozzles.
[0017] The ultraviolet light emitter mounted at the chamber to produce germicidal means for killing microorganisms in the air flow.
[0018] The filter means preferably disposed at the chamber to provide filtering the air through the filter means.
[0019] The energizing means preferably provide electric energy for the ultraviolet light emitter and for the fan means.
[0020] Preferably the apparatus for caring for infants has air nozzles located above the head of the infant. The air nozzles providing the air flow of disinfected air parallel to the part of the bottom supporting the back and the head of the infant.
[0021] Preferably the apparatus for caring for infants has air nozzles disposed at opposite sides of the side guard means and facing each other.
[0022] Preferably the apparatus for caring for infants has air nozzles located behind of a head of the infant.
[0023] Preferably the apparatus for caring for infants recited in claim 1 wherein, an axis of the air flow coming from the air nozzles is parallel to the part of the bottom supporting the back of the infant and a head of the infant.
[0024] Preferably the apparatus for caring for infants has an ultraviolet lamp which emits ultraviolet germicidal radiation and irradiating the air passing the chamber.
[0025] Preferably the apparatus for caring for infants has light emitting diodes emitting germicidal ultraviolet radiation and irradiating the air passing the chamber.
[0026] Preferably the apparatus for caring for infants has the ultraviolet lamp enclosed in a substantially parabolic reflector, the reflector having an aperture for passing filtered air towards the lamp.
[0027] Preferably the apparatus for caring for infants has the ultraviolet lamp enclosed in the substantially parabolic reflector producing substantially collimated germicidal beams.
[0028] Preferably the apparatus for caring for infants has ultraviolet emitter situated at the inlet end of the chamber. The ultraviolet emitter emits germicidal beams towards the outlet end of the chamber.
[0029] Preferably the apparatus for caring for infants has ultraviolet light emitter situated at one sidewall of the chamber. The ultraviolet emitter emits germicidal beams towards other sidewall of the chamber.
[0030] Preferably the apparatus for caring for infants has the ultraviolet light emitter situated coaxially with a long axis of the chamber.
[0031] Preferably the apparatus for caring for infants has the energizing means. Preferably the energizing means is the electricity coming from electrical wiring of a room to energize the ultraviolet emitter and fan means. Preferably the apparatus for caring for infants electrically connected with electrical wiring of the room by flexible cord.
[0032] Preferably the apparatus for caring for infants has a battery located at the infant body support structure. Preferably the battery electrically connected with the ultraviolet emitter and fan means. The battery provides the electricity to energize the ultraviolet emitter and fan means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The invention will be described by way of example and with reference to the accompanying drawings in which:
[0034] FIG. 1 is a schematic view of a preferred embodiment of the invention showing a bouncer as an apparatus for caring for infants with air nozzles disposed at opposite sides of the side guard means and facing each other.
[0035] FIG. 2 is a schematic view of a preferred embodiment of the invention showing a bouncer as an apparatus for caring for infants with air nozzles located behind of a head of the infant.
[0036] FIG. 3 is a schematic side view of a preferred embodiment of the invention showing a bouncer as an apparatus for caring for infants with air nozzles located behind of a head of the infant.
[0037] FIG. 4 is a schematic view of a preferred embodiment of the invention showing a crib as the apparatus for caring for infants and all its components.
[0038] FIG. 5 is a schematic view of a preferred embodiment of the invention showing a cross sectional view of a chamber and its components wherein the ultraviolet light emitter is situated at the inlet end of the chamber and emits germicidal beams towards the outlet end of the chamber.
[0039] FIG. 6 is a schematic view of a preferred embodiment of the invention showing a cross sectional view of the chamber and its components wherein, the ultraviolet light emitter is situated coaxially with a long axis of the chamber.
[0040] FIG. 7 is a schematic view of a preferred embodiment of the invention showing a cross sectional view of the chamber and its components wherein the ultraviolet lamp enclosed in a substantially parabolic reflector, the reflector having an aperture for passing filtered air towards the lamp.
DETAILED DESCRIPTION OF THE INVENTION
[0041] The present invention provides an apparatus for caring for an infant, generally referred to by reference 100 . The preferred embodiment of the invention is shown in FIG. 1-FIG . 7 .
[0042] The apparatus for caring for an infant 100 , includes, the infant body support structure, with the bottom 1 , 2 , high ends 3 , 4 , side guard means 5 , 6 . The air nozzles 10 , 11 , and 12 mounted on the infant body support structure and located at the end of the infant body support structure supporting the head 31 of the infant 30 . The air nozzles 10 , 11 , and 12 located above the head 31 of the infant 30 , and provide the air flow 20 , 21 of disinfected air. The air flow 20 , 21 of disinfected air is parallel to the part of the bottom 1 supporting the back and the head 31 of the infant 30 . The chamber 7 is mounted at the lower part of the infant body support structure. The chamber 7 has the air inlet 8 at one end and the air outlet 9 at the opposite end.
[0043] The fluid communication means 23 connects the air outlet 9 of the chamber 7 at one end with the air nozzles 10 , 11 , 12 at the another end. The fan means 24 is mounted at the chamber 7 , and generates air flow through the chamber 7 .
[0044] According to the preferred embodiment the ultraviolet light emitter 25 is mounted at the chamber 7 to produce germicidal means for killing microorganisms in the air flowing through the chamber 7 .
[0045] The filter means 22 is located at the inlet opening 8 of the chamber 7 . The filter means 22 provides filtering the air flow, entering the chamber 7 .
[0046] The energizing means provide the energy for the ultraviolet light emitter 25 , and for the fan means 24 .
[0047] According to the preferred embodiment the air nozzles 11 , 12 disposed at opposite sides of the side guard means 5 , 6 above of a head 31 of the infant 30 , and facing each other.
[0048] According to another preferred embodiment the air nozzles 10 located behind and above of a head 31 of the infant 30 .
[0049] According to the preferred embodiment, the axes of the air flows 19 , 20 , 21 coming from the nozzles 10 , 11 , 12 are parallel to a part of the bottom 1 supporting the back of the infant and the head 31 of the infant 30 .
[0050] According to the preferred embodiment the ultraviolet light emitter 25 includes the ultraviolet lamp.
[0051] According to another preferred embodiment ultraviolet light emitter includes the light emitting diode.
[0052] According to the preferred embodiment the ultraviolet light emitter 25 enclosed in a substantially parabolic reflector 28 , the reflector having an aperture for passing filtered air towards the ultraviolet light emitter.
[0053] According to the preferred embodiment the germicidal means for killing microorganisms in the air flow include substantially collimated germicidal beams.
[0054] Preferably the ultraviolet light emitter 25 is situated at the inlet end of the chamber 7 and emits germicidal beams towards the outlet end of the chamber 7 .
[0055] Preferably the ultraviolet light emitter 25 is situated at the one sidewall of the chamber 7 and emits the germicidal beams towards the other sidewall of the chamber 7 .
[0056] Preferably the ultraviolet light emitter 25 is situated coaxially with the long axis of the chamber 7 .
[0057] Preferably the energizing means has the electricity coming from electrical wiring of the room. A flexible electrical cord 26 (not shown) connects electrical wiring of the room with the fan means 24 and the ultraviolet emitter 25 . The electricity powers the fan means 24 , and the ultraviolet emitter 25 . The ultraviolet emitter 25 produces and sends germicidal beams to irradiate the air flow inside of the chamber 7 to kill infections viruses and bacteria. The fan means 24 moves the air flow through the filter means 22 , the chamber 7 , fluid communication means 23 , and air nozzles 10 , 11 , 12 .
[0058] According to another preferred embodiment the energizing means has the electricity from a battery 27 (not shown). The battery 27 located at the infant body support structure. The battery 27 is connected with the fan means 24 and the ultraviolet emitter 25 by electrical wires. The electricity powers the fan means 24 , and the ultraviolet emitter 25 . The fan means 24 moves the air flow through the filter means 22 , the chamber 7 , fluid communication means 23 , and air nozzles 10 , 11 , 12 . The ultraviolet 25 emitter produces and sends germicidal beams to irradiate the air flow inside of the chamber 7 and to kill infections viruses and bacteria.
[0059] In the present invention an apparatus for caring for infants provides a protection for the infant from respiratory infections. The protection for the infant 30 disposed on the bottom 1 , 2 of the infant body support structure may be reached by providing of the air flow 19 , 20 , and 21 of infections free air into breathing zone of the infant.
[0060] 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.
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An apparatus for caring for infants, which is used for caring for infants at home or during visits of doctor's offices, public places or private homes. The apparatus relates to cribs and bouncers for caring for infants and protects infants from respiratory infections.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] Not Applicable
FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
SEQUENCE LISTING OR PROGRAM
[0003] Not Applicable
BACKGROUND OF INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to the drying a paper webs, specifically with configurations for through-air-drying of those webs.
[0006] 2. Background of the Invention
[0007] Paper products, e.g., tissues, have conventionally been manufactured by forming a wet paper web on a fabric-carrying sheet, which then carries the paper web through a pressing section to remove the excess water from the web. After pressing the web to remove excess water, the paper web would then be fed to a separate drying section to fully remove the remaining moisture from the web. This step of pressing the web, however, reduces bulk and absorbency. Therefore, as opposed to leaving the web as a flat sheet on a single plane, rotatable air-heated drum dryers over which the web traveled were utilized in combination with an imprinting fabric sheet. Dryer hoods and air supply ducts are widely used in connection with these rotary drums, wherein pressurized drying air is introduced into the roll or at various points in the hood to contact one exposed surface of the wet web as it progresses around the dryer with the exit path for the air being positioned on the other side of the rotary drum. This process is known as through air drying (TAD). U.S. Pat. No. 3,303,576 issued to Sisson discloses one such drying assembly in which a moving stream of pressurized drying air is circulated about a paper web traveling about the periphery of a rotatable roll having apertures formed therein. Sisson utilizes a system where the hot drying air travels from the inside of the rotatable roll to the outside through the apertures, while the web travels about the outer surface of the roll. With such rotatable rolls usually being composed of metal, this inside-to-outside type drying requires smaller diameter, multiple rolls because a larger diameter results in the web and fabric sheet lifting away from the roll surface at the air flows and pressures of commercial interest.
[0008] U.S. Pat. No. 3,432,936 to Cole et al. avoids the problems with inside-to-outside drying by employing a configuration, which moves drying air from the exterior of a rotatable roll through the paper web and into the interior of the rotatable roll, otherwise known as outside-to-inside drying. Web and fabric sheet lifting do not impose airflow restrictions in outside-to-inside drying, because the air is blowing them onto the roll surface. Also, this configuration positions the metal rotatable roll on the cool side of the paper web, which allows for improved maintenance and drum life. However, when two or more of these rotatable rolls employing outside-to-inside drying are used, at least two carrying rolls must contact the paper web. Whenever wet paper webs contact carrying rolls, machine run ability problems as well as product quality problems may be encountered, especially when the web is wet in the range of 65% moisture and higher moisture. One of the most important shortcomings associated with this paper drying machine is that the paper web must come into contact with a carrying roll whenever more than one rotatable drying roll is employed. Further, machines that have one roll have limited drying capacity and are therefore of limited commercial interest.
[0009] However, the most efficient use of space in these machines would be to use a combination of inside-to-outside drying rolls with outside-to-inside drying rolls. U.S. Pat. No. 1,718,573 issued to Millspaugh discloses a paper making machine which discloses removing moisture from a paper web in an outside-to-inside fashion using a suction roll followed by an inside-to-outside removal of moisture by forcing steam through the paper web as it passes over a blower roll. It should be noted, however, that the device disclosed by Millspaugh utilizes steam with its blower roll. Because of the water content of steam, the medium cannot be used to dry a sheet to the required solids content. Furthermore, it is economically more efficient and proficient to employ heated air rather than a combination of air and steam when using a blowing device to dry a wet paper web.
[0010] U.S. Pat. No. 5,636,452 to Thorp et al. discloses a drying apparatus having two TAD rolls with one TAD employing inside-to-outside drying air and the other TAD roll employing outside-to-inside drying air. Thorp et al. is limiting in that its drying capacity is not sufficient to reach world class speeds found in present drying machines. The surface drying area of the two TAD rolls of Thorp et al. is less than that found in typical new TAD drying machines. Additionally, the configuration of Thorp et al. produces limited wrap of the paper web around its outside-to-inside drying drum, providing less drying surface area. In order to increase wrap, without the use of an outside roll that would touch the paper web, both TAD rolls of Thorp et al. are oriented at an angle. This leads to the need to have the exhaust hoods positioned at an angle as well, resulting in a complex and expensive design, especially when retrofitting existing machines.
[0011] U.S. Pat. No. 6,581,301 to Thorp et al. discloses a paper drying machine that reduces some of the difficulties inherent in prior known devices by permitting all of the hoods to be positioned in the customary vertical position, to provide greater flexibility and take advantage of vertical space, which is typically more available when retrofitting existing drying machines. However, the invention requires at least two separate hot air systems, which is both capital intensive and requires additional building space. Secondly, it does not benefit from the added drying inherent in between the rotary drums or rolls that is possible if one hot air system can be used that continually dries the web path from the first drum to the last.
[0012] It is an object of the present invention to provide a paper drying machine that reduces or wholly overcomes some or all of the difficulties in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of preferred embodiments.
SUMMARY
[0013] The principles of the invention may be used to advantage to provide a drying machine having improved drying capacity within a limited amount of space. Such a construction advantageously uses only one hot air system, one supply plenum hood and one exhaust hood system to supply all TAD section drums and rolls. This provides greater flexibility, and takes better advantage of vertical and horizontal space, which is typically more important when retrofitting existing drying machines. Additionally, the present invention may provide greater wrap around its air permeable drying drums in certain embodiments. A further benefit of the new approach is the potential addition of smaller diameter air-permeable or non-air-permeable carrier rolls touching the paper web, once the dryness of the sheet has achieved the level required to avoid roll build up, in contrast to previous inventions that used only air permeable drying drums with high open area for drying. This addition of more closely spaced carrier rolls can be utilized to substantially increase the TAD drying length possible within an existing machine.
[0014] A paper drying apparatus to dry a paper web carried on a fabric sheet includes a first rotatable drum to carry a paper web. A second rotatable drum (or carrier roll) to carry the paper web is positioned downstream of the first rotatable drum with respect to the paper web carried by the first and second rotatable drums. A third rotatable drum (or carrier roll) to carry the paper web is positioned downstream of the second rotatable drum (or roll) with respect to the paper web carried by the first, second, and third rotatable drums. Since the drums are arranged in a serpentine fashion, the same, vertical direction of air can be used to supply all rolls and always blow the sheet into the carrier fabric, while it is being dried, ensuring that it remains attached to the carrier fabric during the drying process, even though some rotatable drums have inside-to-outside air flow and others have outside-to-inside air flow.
[0015] By the nature of the sheet and dryer support fabric remaining inside the drying system in between rotatable drums and carrier rolls, the maximum drying benefit is derived from the system, avoiding the cooling affect between stations of previous inventions.
[0016] From the foregoing disclosure, it will be readily apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this area of technology, that the present invention provides a significant advance. Preferred embodiments of the paper drying machine of the present invention can provide improved drying capacity, while reducing the cost of retrofitting existing paper drying machines. These and additional features and advantages of the invention disclosed here will be further understood from the following detailed disclosure of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The preferred embodiments are described in detail below with reference to the appended drawing. FIG. 1 is a schematic side view of a paper drying machine in accordance with a preferred embodiment of the present invention. The figure referred to is not drawn necessarily to scale and should be understood to present a representation of the invention, illustrative of the principles involved. Some features of the serpentine paper drying machine depicted in the drawings have been enlarged or distorted relative to others to facilitate explanation and understanding. Paper drying machines as disclosed herein, will have configurations and components determined, in part, by the intended application and environment in which they are used.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] Referring now to FIG. 1 , a paper drying device 1 in accordance with a preferred embodiment of the present invention is illustrated for removing moisture from a wet paper web 4 , which is the product of a paper making machine, not shown here. Paper drying device 1 is supported on a floor or other surface 3 . Paper web 4 is carried from a paper making process (not shown) to drying device 1 by a fabric sheet 2 , wherein fabric sheet 2 travels about the perimeter of a couch roller 5 and a roller 6 . In between rollers 5 and 6 , paper web 4 is contacted by and transferred to a fabric sheet 8 as fabric sheet 8 passes by a pick-up device or shoe 10 . Pick-up shoe 10 may comprise a transfer roller, transfer shoe or any other structure to transfer paper web 4 from fabric sheet 2 to fabric sheet 8 . Such transfer devices often employ a vacuum to aid in the transfer of the paper web from one transfer fabric to another. Fabric sheet 8 conveys paper web 4 throughout drying device 1 and forms a closed loop through drying device 1 , returning to the paper web transfer area at pick up shoe 10 . The paper web 4 is transferred to fabric sheet 8 , fabric sheet 8 carries paper web 4 through the drying chamber 12 . As paper web 4 passes downstream through paper drying device 1 , it passes past a sealing roll, 13 , and then around a first rotatable drum 14 , a second rotatable drum, 15 , and then a series of serpentine carrier rolls, 16 to a seal roll 17 at the other end of the drying chamber. The drying chamber has a heated air supply 18 and an exhaust hood 19 for providing an exit for the heated air from within the drying chamber.
[0019] Rotatable drums 14 and 15 have a porous surface permeable to air so that the drying air supplied by air supply 18 passes through the surface of drum 14 and to the interior 20 of drum 14 . and on through the web to the exhaust hood 19 . The web continues down around rotatable drum 15 as air continues to be supplied by drying chamber 18 and exhausted from the interior 21 of roll 15 and into the exhaust hood 19 . At this point the web is dry enough that it can be contacted by air permeable or solid carrier rolls 16 which are located in a serpentine arrangement until the desired moisture of web 4 has been achieved. The diameters and numbers of rotatable rolls 14 and 15 can be varied based on process requirements to achieve dryness that will permit a carrier roll to contact the web. The illustrated embodiment, employs through-air-drying (TAD) to remove moisture from paper web 4 while it travels around the perimeter of rotatable drum 14 . Thus, air supply 18 forces air in the direction of arrow A into the interior 20 of drum 14 on which fabric sheet 8 does not travel. The air then travels from the interior 20 of drum 14 through the porous surface of drum 14 in the direction of arrow A toward exhaust hood 19 . Accordingly, after the air passes through the permeable surface of the drum, the air is forced through paper web 4 and fabric sheet 8 , both of which are traveling about the surface of rotatable drum 14 . The path of the drying air is known as inside-to-outside TAD, because the air is traveling from the inside of drum 14 to the outside of drum 14 while it is removing moisture from paper web 4 . While the inside-to-outside drying air exits rotatable drum 14 and passes through paper web 4 , the air applies a force to lift fabric sheet 8 and paper web 4 from the surface of drum 14 , wherein the tautness of fabric sheet 8 resists this force and holds paper web 4 in abutment to drum 14 . The restricting force due to the tension of fabric sheet 8 is calculated as F=T divided by R, where T is the tension of the fabric sheet in pounds per linear inch, and R is the radius of the roll in inches. Since this restraining force is inversely proportional to the roll radius, larger rolls have a lower restraining force. Therefore, rolls having inside to outside air flow typically have a diameter less than 10 feet. The size of rotatable drum 14 will be dependent on fabric tension capabilities and layout constraints.
[0020] After leaving rotatable drum 14 , the fabric sheet 8 and paper web 4 continue to drum 15 which employs TAD to further dry the paper web 4 ; however, second rotatable roll 15 employs outside-to-inside drying air, as opposed to the inside-to-outside drying air used in rotatable roll 14 . Fabric sheet 8 enters second rotatable drum 15 and travels about its outer surface, whereon fabric sheet 8 is in abutment with the surface of rotatable drum 15 . The heated air supply 18 now forces heated air, in the direction of arrow A, initially through paper web 4 and then passes through fabric sheet 8 , and finally the air passes through the air permeable surface of rotatable drum 15 into the interior 21 or rotatable drum 15 .
[0021] After passing into the interior of drum 15 , the air passes in the direction of arrow A through a portion of rotatable drum 15 on which fabric sheet 8 does not travel, and subsequently to exhaust hood 19 . While rotatable drum 15 may be similar in size to rotatable drum 14 , rotatable drum 15 can be larger in diameter than drum 14 , as the drying air does not exert a lifting force on the fabric sheet or paper web, A larger drum is generally more effective in removing moisture from the paper web.
[0022] After leaving second drying chamber 30 , fabric sheet 8 next carries paper web to a series of carrier rolls 16 . After traveling through third drying chamber 12 , fabric sheet 8 conveys paper web 4 from seal roll 17 to a final rotatable drying drum 22 , a steam heated drum conventionally known as a Yankee or crepe dryer. Drum 22 typically has a hood (not shown), and provides the opportunity to crepe (also not shown). Drying drum 22 and its associated creping impart dry bulk, softness, drapability, and machine direction stretch to paper web 4 . Fabric sheet 8 and paper web 4 proceed between the periphery of a pressure roll 23 and drying drum 22 , wherein pressure roll 23 abuts fabric sheet 8 and transfers paper web 4 from fabric sheet 8 to the perimeter of drying drum 22 . Paper web 4 then rotates along with the perimeter of drying drum 22 in a final drying procedure for paper web 4 . Fabric sheet 8 then continues to travel along its loop about the perimeter of a series of carrier rolls 24 , returning to pick up shoe 10 and then repeating the above stated process of drying paper web 4 . As fabric sheet 8 travels back to pick up shoe 10 , it passes through a fabric cleaning and conditioning device 25 to remove residual fibers, fabric release agents, and paper making chemicals from fabric sheet 8 . In addition, a guide roll 26 is adjustably mounted so that its position may be altered to modify the position of fabric sheet 8 as it travels through the drying loop. There is also a stretch roll (not shown) to adjust the length and tension of fabric sheet 8 . After passing through fabric cleaning and conditioning device 25 , fabric sheet 8 is treated by shaping box 27 . Shaping box 27 provides for wet shaping of paper web 4 by pulling the fibers of the web into interstices of fabric sheet 8 . As paper web 4 is dried, voids, or pillows, are created in the web, providing increased absorbency for the paper web. Following shaping box 58 , fabric sheet 8 is treated by vacuum box 28 , providing additional de-watering and shaping of fabric sheet 8 if needed. It is to be appreciated that in certain preferred embodiments, the position of shaping box 27 and vacuum box 28 are reversed with respect to one another so that fabric sheet 8 is first treated by vacuum box 27 and then by shaping box 28 .
[0023] In a preferred embodiment, the direction of each of arrow A, and thus, the direction of airflow through the drying chambers, is substantially perpendicular to surface 3 . Consequently, the exhaust hood is located vertically above a corresponding air supply. In this configuration, drying chamber 12 is considered to be aligned vertically with respect to surface 3 and drying device 1 . The vertical orientation of the drying chambers allows greater use of vertical space in drying device 1 , which is typically more available than horizontal space, especially in existing drying machines. This configuration enables existing drying machines to be retrofitted with TAD dryers in a cost effective manner, utilizing existing designs and avoiding costly reconstruction of these large and expensive machines. The minimal space required for this TAD roll configuration allows current paper drying machines to be adapted to include this improved configuration without having to move the large components in the drying process, such as the Yankee dryer 22 , while providing greater drying capacity. Therefore, the operational downtime of a paper drying machine which would result from adapting the paper drying machine to incorporate this improved TAD roll configuration would be minimal.
[0024] The configuration of the TAD rolls and fabric sheet 8 in the present invention provides greater drying length and improved drying capacity. Preferred embodiments of the present invention can provide sufficient drying capacity to achieve world class speeds on the order of 5,000 feet per minute on 13 pound per 3,000 square feet tissue or towel product. The configurations rotary drum and carrier roll diameters can vary in size and numbers dependent on the process requirements and the physical restraints of the practical installation.
[0025] Such a configuration is also an improvement over TAD machines having a wet creping action followed by drying with no Yankee dryer or dry creping. The present invention provides an improved product with dry crepe, and, therefore, ample machine direction stretch for desired converting functions. In light of the foregoing disclosure of the invention and description of the preferred embodiments, those skilled in this area of technology will readily understand that various modifications and adaptations can be made without departing from the scope and spirit of the invention. All such modifications and adaptations are intended to be covered by the following claims.
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A paper drying apparatus to dry a paper web carried on a fabric sheet includes a first rotatable drum to carry a paper web. A second rotatable drum or carrying roll is positioned downstream to the first drum with respect to the paper web carried by the first drum and second drum or roll. Successive drums or rolls are positioned downstream of the first two rolls to carry the paper web through the complete drying system. A common air supply system is utilized to direct air through the initial and successive rolls, with the direction of the drying air always contacting the sheet before the carrier fabric.
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FIELD OF THE INVENTION
[0001] The invention relates to an electrochemical energy source, comprising: a substrate, and at least one stack deposited onto said substrate, the stack comprising at least the active layers: an anode, a cathode, and an intermediate solid-state electrolyte separating said anode and said cathode. The invention also relates to an electronic device provided with an electrochemical energy source according to the invention. The invention further relates to a method for the manufacturing of an electrochemical source according to the invention, comprising the step of: A) depositing at least one stack deposited onto a substrate, the stack comprising at least the following active layers: an anode, a cathode, and an intermediate solid-state electrolyte separating said anode and said cathode.
BACKGROUND OF THE INVENTION
[0002] Electrochemical energy sources based on solid-state electrolytes are known in the art. These (planar) energy sources, or ‘solid-state batteries’, efficiently convert chemical energy into electrical energy and can be used as the power sources for portable electronics. At small scale such batteries can be used to supply electrical energy to e.g. microelectronic modules, more particular to integrated circuits (IC's). An example hereof is disclosed in the international patent application WO2005/027245, where a solid-state thin-film battery, in particular a lithium ion battery, is fabricated directly onto a structured silicon substrate provided with multiple slits or trenches in which an electron-conductive barrier layer, and a stack of a silicon anode, a solid-state electrolyte, and a cathode are deposited as active layers successively. The slits or trenches are provided in the substrate to increase the contact surface area between the different components of the stack to improve the rate capacity of the battery. The structured substrate may comprise one or more electronic components to form a so-called system-on-chip. The barrier layer is adapted to counteract diffusion of intercalating lithium into said substrate, which diffusion would result in a significant diminished storage capacity of the electrochemical source. Although the known battery exhibits commonly superior performance as compared to conventional solid-state batteries, the known battery has several drawbacks. It has been found that a major drawback of the known battery is that the active layers of the stack will commonly easily degrade due to an non-optimum choice of layer materials and/or the deposition order of the active layers of the stack. This degradation of one or more active layers may be manifested in that these active layers may decompose, may react with adjacent active layers to form interfacial layers with inferior properties and/or may (re)crystallize to form phases with unwanted properties.
[0003] It is an object of the invention to provide a relatively stable electrochemical energy source.
SUMMARY OF THE INVENTION
[0004] This object can be achieved by providing an electrochemical energy source according to the preamble, characterized in that each active layer of the stack which is deposited prior to a subsequent active layer of the stack has a higher annealing temperature than the annealing temperature of the subsequent active layer. It has been found that the degradation of active layers in conventional energy sources known from the prior art, is often caused during deposition, in particular during annealing (also known as curing), of an active layer at a relatively high annealing temperature which may easily overheat, and consequently degrade adjacent active layers already deposited onto the substrate and annealed at a relatively low annealing temperature. This overheating of active layers of the stack deposited earlier may result in decomposition of these layers, allowing these layers to react with other adjacent layers to form detrimental interfacial layers with inferior properties, and/or allowing these layers to (re)crystallize to form phases with undesired properties. By gearing the annealing temperatures of the different active layers, and hence the active layers as such, into a successive order, degradation of these active layers can be prevented in a relatively efficient manner. According to the invention, the deposition order of the different active layers of the stack of the electrochemical energy source according to the invention is dictated by the order of the successive annealing temperatures, or temperature ranges, of the active layers to obtain a relatively stable electrochemical energy source having a relatively reliable performance, and which be manufactured in a relatively reliable manner. During manufacturing of the energy source according to the invention this means in general that the active layer deposited firstly can be deposited and/or annealed at any temperature (as long as the substrate allows it). The subsequent active layer of the stack shall be deposited/annealed at a temperature lower, and preferably significantly lower (about 50° C.), than the first active layer, and so on. This inherently means that the final active layer of the stack shall be deposited at the lowest temperature. Commonly, the annealing process is considered as being a (final) part of the deposition process of an active layer, wherein each active layer has its own optimum annealing temperature, or annealing temperature range, with which this active layer will acquire the specific material properties needed to function properly in the battery stack. Besides the critical deposition order which is applied to the electrochemical energy source according to the invention, preferably the materials of the different active layers are mutually chemically stable and compatible. A reaction between two chemically incompatible materials should preferably be avoided at any (annealing) temperature to secure a durable and adequate functioning of the electrochemical energy source according to the invention.
[0005] In a preferred embodiment the solid-state electrolyte is deposited on top of the cathode, and the anode is deposited on top of the solid-state electrolyte. According to this embodiment a stack is applied, wherein the cathode, the solid-state electrolyte, and the anode are deposited successively onto the substrate. The reason to apply this specific deposition order is that commonly the annealing temperature of the cathode is higher than the annealing temperature of the solid-state electrolyte which is thereupon higher than the annealing temperature of the anode. Although it is expected that commonly this deposition order will be applied in most electrochemical energy sources according to the invention, the invention is not limited to this specific deposition order. It could also be conceivable for a person skilled in the art to apply a reverse stack of an anode, on top of which an electrolyte is deposited, on top of which electrolyte a cathode is deposited. This reverse stack will probably be applied in case the annealing temperature of the anode is higher than the annealing temperature of the electrolyte which is thereupon higher than the annealing temperature of the cathode.
[0006] The electrochemical energy source preferably comprises at least two current collectors connected to the anode and to the cathode of the stack respectively. It is generally known to apply current collectors as electrode terminals. In case e.g. a Li-ion battery with a LiCoO 2 cathode is applied, preferably an aluminium current collector is connected to the LiCoO 2 cathode. Alternatively or in addition a current collector manufactured of, preferably doped, semiconductor such as e.g. Si, GaAs, InP, as of a metal such as silver, gold, platinum, copper or nickel may be applied as current collector in general with solid-state energy sources according to the invention. The current collectors are not part of the stack as defined above. Current collectors are commonly deposited at room temperature. Preferably a corrosion resistant current collector, such as a platinum current collector, is deposited onto the substrate, in case the first active layer of the stack is to be deposited in an oxygen environment at an annealing temperature (considerably) higher than room temperature. In case said first active layer is deposited in an inert environment, wherein practically no oxygen is present, at an increased annealing temperature the current collectors may be made of a material which is (significantly) less corrosion resistant, such as copper for example.
[0007] In a preferred embodiment of the energy source according to the invention the substrate and the anode are separated by means of an electron-conductive barrier layer adapted to at least substantially preclude diffusion of intercalating active species into said substrate. This preferred embodiment is commonly very advantageous, since intercalating reactive species taking part of the (re)charge cycles of the energy system according to the invention often diffuse into the substrate, such that these reactive species do no longer participate in the (re)charge cycles, resulting in a reduced storage capacity of the electrochemical source. Commonly, a monocrystalline silicon conductive substrate is applied to carry electronic components, such as integrated circuit, chips, displays, et cetera. This crystalline silicon substrate suffers from the drawback that the intercalating species diffuse relatively easily into said substrate, resulting in a reduced capacity of said energy source. For this reason it is considerably advantageous to apply a barrier layer onto said first substrate to preclude said unfavourable diffusion into the substrate. Migration of the intercalating species will be blocked at least substantially by said barrier layer, as a result of which migration of these species through the substrate will no longer occur. It is in particularly advantageous to apply a barrier layer in case the anode is connected to the substrate, wherein the anode is adapted for storage of active species in an atomic state. In lithium ion batteries commonly an (amorphous) silicon anode is deposited onto a (monocrystalline) silicon substrate, said silicon anode being adapted to store lithium species in an atomic state. To prevent a loss of effective active species preferably a barrier layer as defined above is applied to mutually separate the (silicon) anode and the (silicon) substrate. In case the anode is, however, not adapted to store active species in atomic state but rather in ionic state, commonly the application of a barrier layer is no longer required. An example of an anode which is adapted to store active species in ionic state is an oxygen containing anode. In this latter case, preferably a relatively corrosion resistant current collector, which may be made of platinum, is connected to the oxygen containing anode to counteract oxidation of the current collector during deposition of the anode layer. In case an electron-conductive barrier layer is applied this barrier layer may (also) be used to function as a current collector for the anode. In a preferred embodiment the barrier layer is preferably at least substantially made of at least one of the following compounds: tantalum (Ta), tantalum nitride (TaN), titanium (Ti), and titanium nitride (TiN). These compounds have as common property a relatively dense structure which is permeable for electrons and impermeable for the intercalating species, among which lithium (ions). The material of the barrier layer is however not limited to these compounds.
[0008] Preferably, the electrochemical energy source is formed by at least one battery selected from the group consisting of alkaline batteries and alkaline earth batteries. Alkaline (earth) storage batteries such as nickel-cadmium (NiCd), nickel-metal hydride (NiMH), or lithium-ion (Li-ion) storage batteries are commonly highly reliable, have a satisfying performance, and are capable of being miniaturized. For these advantages, they are used both as the power sources of portable appliances and industrial power sources, depending on their size. Preferably, the at least one electrode of the energy source, preferably formed by battery, is adapted for storage of ions of at least one of following elements: hydrogen (H), lithium (Li), beryllium (Be), magnesium (Mg), copper (Cu), silver (Ag), aluminium (Al), sodium (Na) and potassium (K), or any other suitable element which is assigned to group 1 or group 2 of the periodic table. So, the electrochemical energy source of the energy system according to the invention may be based on various intercalation mechanisms and is therefore suitable to form different kinds of batteries, e.g. Li-ion batteries, NiMH batteries, et cetera.
[0009] In a preferred embodiment the cathode is made of at least one material selected from the group consisting of: LiCoO 2 (600-800° C.) LiMn 2 O 4 (˜600° C.), LiFePO 4 (˜700° C.), V 2 O 5 (˜500° C.), MoO 3 (˜280° C.), WO 3 (˜300° C.), and LiNiO 2 . It is has been found that at least these materials are highly suitable to be applied in lithium ion energy sources and, moreover, these materials have a predefined optimum annealing temperature range or temperature range (cited above in parentheses), based upon which an optimum deposition order may be determined. Examples of a cathode in case of a proton based energy source are Ni(OH) 2 and NiM(OH) 2 , wherein M is formed by one or more elements selected from the group of e.g. Cd, Co, or Bi. It may be clear that also other cathode materials may be used in the electrochemical energy source according to the invention. The anode is preferably made of at least one material selected from the group consisting of: Si (<<600° C.), SnO x (˜350° C.), Li 4 Ti 5 O 12 (600-800° C.), SiO x , LiSiON, LiSnON, and LiSiSnON, in particular Li x SiSn 0.87 O 1.20 N 1.72 . As the cathode materials, these materials are suitable to be applied in a lithium ion battery, and, moreover, have a predefined optimum annealing temperature or temperature range (cited above in parentheses). The solid-state electrolyte is made of at least one material selected from the group consisting of: Li 5 La 3 Ta 2 O 12 (Garnet-type class; 600-700° C.), LiPON (˜room temperature), LiNbO 3 (˜400° C.), LiTaO 3 (˜400° C.), and Li 9 SiAlO 8 (˜900° C.), These solid-state electrolyte materials are suitable to be applied in lithium ion batteries, and have a known optimum annealing temperature (cited above in parentheses). Other solid-state electrolyte materials which may be applied smartly are lithium orthotungstate (Li 2 WO 4 ), Lithium Germanium Oxynitride (LiGeON), Li 14 ZnGe 4 O 16 (lisicon), Li 3 N, beta-aluminas, or Li 1.3 Ti 1.7 Al 0.3 (PO 4 ) 3 (nasicon-type). A proton conducting electrolyte may for example be formed by TiO(OH), or ZrO 2 H x .
[0010] In a preferred embodiment the substrate is at least partially made of silicon. More preferably, a monocrystalline silicon conductive substrate is applied to carry electronic components, such as integrated circuit, chips, displays, et cetera. This crystalline silicon substrate suffers from this drawback that the intercalating active species diffuse relatively easily into said substrate, resulting in a reduced capacity of said energy source. For this reason it is considerably advantageous to apply a barrier layer onto said substrate to preclude said unfavourable diffusion into the substrate.
[0011] The invention also relates to an electronic device provided with at least one electrochemical energy source according to the invention. An example of such an electric device is a shaver, wherein the electrochemical energy source may function for example as backup (or primary) power source. Other applications which can be enhanced by providing a backup power supply comprising an energy system according to the invention are for example portable RF modules (like e.g. cell phones, radio modules, et cetera), sensors and actuators in (autonomous) micro systems, energy and light management systems, but also digital signal processors and autonomous devices for ambient intelligence. It may be clear this enumeration may certainly not being considered as being limitative. Another example of an electric device wherein an energy source according to the invention may be incorporated (or vice versa) is a so-called ‘system-in-package’ (SiP). In a system-in-package one or multiple electronic components and/or devices, such as integrated circuits (ICs), chips, displays, et cetera, are embeddded at least partially in the substrate, in particuarly a monocrystalline silicon conductive substrate, of the electrochemical energy source according to the invention.
[0012] The invention further relates to a method according to the preamble, characterized in that during step A) the active layers of stack are deposited in a deposition order wherein an subsequent active layer of the stack which is deposited onto a prior active layer of the stack has a lower annealing temperature than the annealing temperature of said prior active layer of the stack. Advantages of this method have already been elucidated above in a comprehensive manner. Preferably, during step A) the cathode, the solid-state electrolyte, and the anode are deposited successively onto the substrate. Commonly this deposition order will be in harmony with a decrease in an optimum annealing temperature for the active layers of the stack respectively. In a preferred embodiment the method further comprises step B) of depositing a first current collector onto the substrate prior to step A), on top of which current collector the stack is deposited during step A). In another preferred embodiment the method further comprises step C) of depositing a second current collector onto the stack deposited onto the substrate during step A). Particular examples of materials of active layers of the stack, and of the current collector(s) to be applied have already been elucidated above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention is illustrated by way of the following non-limitative examples, wherein:
[0014] FIG. 1 shows a schematic cross section of an electrochemical energy source according to the prior art, and
[0015] FIG. 2 shows a schematic cross section of an electrochemical energy source according to the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0016] FIG. 1 shows a schematic cross section of an electrochemical energy source 1 known from the prior art. An example of the electrochemical energy source 1 shown in FIG. 1 is also disclosed in the international patent application WO2005/027245. The known energy source 1 comprises a lithium ion battery stack 2 of an anode 3 , a solid-state electrolyte 4 , and a cathode 5 , which battery stack 2 is deposited onto a conductive substrate 6 in which one or more electronic components 7 are embedded. In this example the substrate 6 is made of doped silicon, while the anode 3 is made of amorphous silicon (a-Si). The cathode 5 is made of LiCoO 2 , and the solid-state electrolyte is made of LiNbO 3 . Between the battery stack 2 and the substrate 6 a lithium barrier layer 8 is deposited onto the substrate 6 . In this example, the lithium diffusion barrier layer 8 is made of tantalum. The conductive tantalum layer 8 acts as a chemical barrier, since this layer counteracts diffusion of lithium ions (or other active species) initially contained by the stack 2 into the substrate 6 . In case lithium ions would leave the stack 2 and would enter the substrate 6 the performance of the stack 2 would be affected. Moreover, this diffusion would seriously affect the electronic component(s) 7 embedded within the substrate 6 . In this example, the lithium diffusion barrier layer 8 also acts as a current collector for the anode 3 in the known electrochemical energy source 1 . The energy source 1 further comprises an additional current collector 9 made of aluminium which is deposited on top of the battery stack 2 , and in particularly on top of the cathode 5 . Deposition of the individual layers 3 , 4 , 5 , 8 , 9 can be achieved, for example, by means of CVD, sputtering, E-beam deposition or sol-gel deposition. Deposition of the different active layers 3 , 4 , 5 of the stack 2 in the deposition order as shown in FIG. 1 may likely yield problems, which are detrimental for the performance of the energy source 1 both in short term and in long term. These problems to be expected can be deduced from the following table (Table 1) in which more details are given regarding the materials, especially the required phases and optimum annealing temperatures needed to obtain these preferred phases for each individual material.
[0000] TABLE 1 Depo- Optimum sition Preferred annealing order Type Material phase temperature 1 barrier and Ta — ~room temperature current collector 2 anode a-Si amorphous <<600° C. 3 solid electrolyte LiNbO 3 amorphous <450° C. 4 cathode LiCoO 2 HT- >>600° C. crystalline preferably 800° C. rombohedral 5 current collector Al — ~room temperature
Considering the entire deposition of the different active layers 3 , 4 , 5 , 8 , 9 and in particular the active layers 3 , 4 , 5 of battery stack 2 again, including the data given in Table 1, several possible problems due to a non-optimum deposition order are expected to occur. The deposition of the first layer 1 , id est the barrier layer 8 , onto the substrate 6 at room temperature using Atomic Layer Deposition (ALD) will be readily feasible, as well as the deposition of the silicon anode 3 (substantially) below 600° C., preferably at a few hundred degrees Celsius. Deposition of the solid-state electrolyte 4 made of LiNbO 3 at temperatures below 450° C. will yield amorphous material as required. However, deposition of LiNbO 3 will require an oxygen atmosphere and temperatures around 200° C. in order to decompose metal-organic precursors used during deposition. This can result in the formation of SiCO 2 at the Si/LiNbO 3 interface of the anode 3 and the electrolyte 4 , which is unwanted as SiCO 2 will probably act as a blocking layer.
[0017] Subsequent deposition of LiCoO 2 to form the cathode 5 at temperatures below 600° C. will yield merely amorphous material, which is electrochemically inferior to the preferred HT crystalline phase. However, post annealing at 800° C., in order to crystallize the cathode 5 will cause additional phenomena in the underlying and already deposited layers; the LiNbO 3 electrolyte 4 has a crystallization temperature of about 470° C., and will hence crystallize at this relatively high annealing temperature, resulting in inferior Li-ion conducting properties. The amorphous Si of the anode 3 crystallizes to polycrystalline Si, which is not detrimental to the Li-intercalating behave of the anode 3 . Hugely increasing the annealing temperature of the cathode 5 will result in severe intermixing at the Si/LiNbO 3 interface of the anode 3 and the electrolyte 4 as both are not chemically stable. The deposition of the last layer, the cathode current collector 9 , can be done under relatively mild conditions once again at room temperature and no problems are expected during this deposition step. The above shows that deposition of the active layers 3 , 4 , 5 of the battery stack 2 is not straight-forward and might yield potential bottlenecks.
[0018] FIG. 2 shows a schematic cross section of an electrochemical energy source 10 according to the invention. The electrochemical energy source 10 differs from the electrochemical energy source 1 as shown in FIG. 1 in that the energy source 10 shown in FIG. 2 is characterized by a consistent and smart choice of materials of and subsequent smart deposition order of the different materials as will be elucidated hereinafter. The electrochemical energy source 10 according to the invention comprises a lithium ion battery stack 11 of an cathode 12 , a solid-state electrolyte 13 , and a anode 14 , which battery stack 11 is deposited onto a conductive substrate 15 in which one or more electronic components 16 are embedded. In this example the substrate 15 is made of doped silicon, the cathode 12 is made of LiCoO 2 , the electrolyte 13 is made of Li 5 La 3 Ta 2 O 12 , and the anode 14 is made of amorphous silicon (a-Si). Between the battery stack 11 and the substrate 15 a cathode current collector 17 made of platinum is deposited. On top of the anode 14 an anode current collector 18 is deposited. The anode current collector 18 is made of tantalum in this example, as a result of which conductive tantalum layer 18 may also act as a chemical barrier to preclude diffusion of active species into the substrate 15 in case the anode 14 is brought in (direct) connection with the substrate 15 . Deposition of the individual layers 12 , 13 , 14 , 17 , 18 can be realized again by means of e.g. CVD, sputtering, E-beam deposition or sol-gel deposition. As will be clear the material choice of particular layers 13 , 17 has been modified with respect to corresponding layers 4 , 9 of the energy source 1 shown in FIG. 1 . Moreover, it will be clear the stack 11 has been deposited in reverse order with respect to the deposition order of the stack 2 as shown in FIG. 1 . The improved deposition order can be elucidated by means of the relevant material data given in table 2.
[0000] TABLE 2 Depo- Optimum sition Preferred annealing order Type Material phase temperature 1 cathode current Pt — ~RT collector 2 cathode LiCoO 2 HT- >>600° C. crystalline pref. 800° C. rombohedral 3 solid electrolyte Li 5 La 3 Ta 2 O 12 Garnet-type 600-700° C. 4 anode a-Si amorphous <<600° C. 5 current collector Ta — ~RT
Considering this improved deposition order, it can be seen that the optimum annealing temperature to obtain an active material layer 12 , 13 , 14 of the stack 11 in the preferred phase is lower for each subsequent active layer 13 , 14 than the optimum annealing temperature for each active layer 12 , 13 deposited earlier than the subsequent layers 13 , 14 of the stack 11 . During manufacturing of the electrochemical energy source 10 as shown in FIG. 2 , the deposition of the platinum layer 17 will be readily feasible. The deposition of the LiCoO 2 to form the cathode 12 at an optimum annealing temperature (>>600° C., preferably about 800° C.) will yield the preferred rombohedral phase. As platinum is highly resistant against corrosion, even at temperatures of 600-800° C. in an oxygen environment, no interfacial (blocking) oxide layers will be formed between the Pt and LiCoO 2 . Subsequent deposition of the Garnet-type solid electrolyte 13 utilizing appropriate metal-organic precursors (preferably Li, La, and Ta) can be realised at reduced temperature (600-700° C.) in an oxygen atmosphere. Studies that have been performed show that the Garnet-type electrolyte 13 and LiCoO 2 based cathode 12 are chemically compatible with each other. The deposition of a-Si to form the anode 14 can be readily done at mild temperatures of a few hundred degrees Celsius. The deposition of the anode current collector 18 made of tantalum can be realised at or near room temperature again. It is clear that if a revised deposition order is chosen, and care is taken that the materials are chemically stable versus each other, a complete battery stack 11 can be deposited without any obvious interface phenomena or decomposition. It is noted that the materials opted for in the shown example, in particular as listed in Table 2, can be readily replace by other materials, as long as the requirements stated above are met.
[0019] It should further be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
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An electrochemical energy source, comprising: a substrate, and at least one stack deposited onto said substrate, the stack comprising at least the active layers: an anode, a cathode, and an intermediate solid-state electrolyte separating said anode and said cathode. An electronic device provided with an electrochemical energy source according to the invention and a method for the manufacturing of an electrochemical source according to the invention.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a bundle of heat exchanger tubes connected downstream of a thermal cracking installation with a bundle of heat exchanger tubes held between two tube plates, a method to coat a tube plate as well as the application of a packing material.
Such bundles of heat exchanger tubes are used, for example, in ethylene plants for the production of ethylene by thermal cracking on the upstream side of a transfer line of a cracking oven and described as cracked gas coolers.
2. Description of the Background
Cracked gas coolers must satisfy extraordinarily high requirements with regard to the construction and material properties. The hot reaction mixture (approx. 850° C.) emerging from the cracking oven during the pyrolysis of hydrocarbons like naphtha, heavy petrol or even ethane has to be cooled quickly in the cracked gas coolers to prevent undesirable secondary reactions. The cracked gas coolers or the bundle of heat exchanger tubes serve as an evaporating boiler, in which high-pressure steam is produced by evaporating feed water supplied from the casing.
The cracked gas arriving at great speed from the cracking oven usually enters in the cracked gas cooler from below via a bonnet socket in which the transfer line is axially arranged and impacts on the bottom tube plate and after passing through the heat exchanger tubes of the cracked gas cooler is conveyed to an oil wash and further processing.
Despite the short residence times and high speeds of approx. 300 m/s the cracked gas already contains coke particles, which have a strong eroding affect at these speeds. As far as the construction of the apparatus is concerned, it is not practically feasible to charge evenly all internal tubes of the cracked gas cooler. consequently, the tubes provided in the central regions of the base plate as well as in the core zone region will erode more than those in the peripheral regions.
From EP-A-0 567 674 heat exchangers for the cooling a synthesis gas generated in a coal gasification plant is known, wherein the tube plate on the side of the gas inlet comprises individual parallelepiped-shaped nozzles, provided next to each other and abutting on the outer edges, while each nozzle has a tapered orifice, narrowing to a tubular cross-section protruding into a heat exchanger tube. This solution does not provide a gas-tight seal between the individual parallelepiped-shaped elements. In the cracked gas coolers of an olefin plant this would lead to coke formation in the intermediate spaces and destroy the materials. Furthermore, the ends of the nozzles used form a tear-off edge in the tube, which in the case of the flow velocities of approx. 300 m/s, used in cracked gas coolers, would cause strong whirling resulting in additional erosions.
Furthermore it is known to provide cooling tubes, installed in a reactor, with an erosion-retarding refractory coating (cf. U.S. Pat. No. 4 124 068), for the purposes of reducing the risk of failure of the tube and the ingress on cooling water into the surrounding. reaction mixture at elevated temperatures.
An attempt has been made to encounter the problem of a considerably stronger flow and load occurring in the core zone when compared with the edge zones by, inter alia, tapered baffles (cf. U.S. Pat. No. 35 52 487) or by diffusor-like deflection devices without baffles (German patent 21 60 372) in the bonnet socket.
Furthermore, to even out the flow-through the bonnet socket on the entry side and also to protect the tube plate from erosion it has been suggested to provide the bundle of heat exchanger tubes with baffles made of bars, bent into rings, wherein the rings are provided along the surface of a taper, the tip of which is directed toward the gas inlet (cf. EP 0 377 089 A1.).
This should slow down the coke particles carried away in the region of the core flow by the gas flowing at high velocity and deflect them partly radially outwards, so that they will no longer result in erosion damages on the tube plate or in the tube. On the other hand such baffles result in an undesired pressure difference and loss of yield due to the corresponding increase of the residence tile.
SUMMARY OF THE INVENTION
The invention follows another path, wherein an effective erosion protection is strived for by reinforcing the base plate. The erosions on the lower tube plate made periodic shut-downs of the cracked gas cooler necessary, while this has been remedied by restoring the base plates to the necessary wall thickness by build-up welding. This method is expensive and may not be satisfactory with regard to the resistance of the material applied by welding either. In the case of cracked gas coolers it makes it more difficult that the base plate works not only as an impact plate and as such is subjected to particular erosion, but simultaneously it has to be relatively thin to enable to achieve an as low as possible boundary surface temperature. This is desirable from the point of view of the construction of the apparatus as well as of advantage, . since the entering gases should be cooled as quickly as possible without causing undesirable secondary reactions.
To eliminate the disadvantages mentioned a bundle of heat exchanger tubes is suggested in accordance with claim 1. Advantageous embodiments are described in the sub-claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a tube plate according to the invention in top view (viewed from below).
FIG. 2 shows a section across a cracked gas cooler having a coating according to the invention, in the region of the base plate.
DETAILED DESCRIPTION OF THE INVENTION
The coating is carried out, by means of a packing material having a thickness of 10 to 50, preferably 15 to 30 mm.
For a better adhesion of the packing material or of the coating, anchors, having preferably V-, T-, S- or Y-shapes, in particular having a diameter of approx. 5 mm or a sheet metal construction with a honeycomb structure, having preferably a height of 5 to 10 mm, are welded on the tube plate.
Such anchors are known in the furnace-technology as ECO-VINs for various coating strengths with linings welded on steel plates with masonry behind them, whereby for a better anchoring of the packing material the legs of the anchor can be bent to approx. 60° C. The anchors can be welded to the lower tube plate in a non-spread or spread state.
The coating with the packing material, made of a chemically bonded refractory erosion-resistant material, is applied either by hand or for larger areas by spraying and compacted manually, for example with a flat iron bar and hammer, or by electric tools.
As packing material, described occasionally as piling material, predominantly chemically setting materials, consisting of inorganic raw materials, are used. The setting takes place in the presence of air. A main raw material is, for example, conundrum. A typical composition of such a material is, for example, 85% by weight Al 2 O 3 , 7% by weight SiO 2 , 0.3% by weight Fe 2 O 3 , 3.1% by weight MgO, 4.5% by weight P 2 O 5 and 0.1% by weight alkalies (approximate values). The maximum grain size of the individual components should not exceed 4 mm. To process or produce the packing material this inorganic mixture is diluted with waiter and subsequently processed. It takes at least 24 hours after the application of the packing material for this to settle. This is followed by drying or baking. For this purpose hot air at a temperature of 150-200° C. is circulated for approx. 6 hours over the packing material and afterwards the temperature is increased to approx. 350° C. within 4 hours maximum. Depending on the operating temperature and the possible additives, like steel pins, the thermal conductivity of the set packing material or coating is between 1.5-3.5 W/mK. The abrasion of this coating is less than 8 cm 3 (according to ASTM C-704).
As packing material RESCO-CAST, for example, is suitable, a product of the RESCO Products Inc. Other commercially available suitable products, described as packing material, are PLIRAM Cyclone-Mix D by the Plibrico GmbH. The products mentioned are used, as is known from practice, for example for the internal coating of parts of a FCC (Fluid-Catalytic-Cracker) plant. Such parts of the plant will be cloated, in which the liquefied FCC catalyst moves at a speed of 20-30 m/s at a temperature of approx. 750° C. There is, however, no indication that the packing materials mentioned are suitable for the carrying out of the subject matter of the invention. Rather the reservations, that under special conditions the coating in a cracked gas cooler does not hold and falls into the cracked gas oven, leading to stoppages, had to be overcome, The basis of these reservations is that there was the danger that between the base plate and the coating and/or in the cracks of the coating, layers of growing coke will form similarly to linings with ceramic formed parts, which would finally blow off the coating.
For the purpose of improving the ability to withstand the temperature changes of the coating under the high requirements, steel pins or corrugated steel fibres (C-mix) could be added, inter alia, to the packing material, preferably in a proportion of 1-2% by weight.
In the case of a bundle of heat exchanger tubes of the type mentioned above with a bundle of tubes held between two base plates, the diameter of the transfer line from the cracking oven is usually increased to the diameter of the tube plate in the form of a bonnet socket.
In principle, in such a construction only the zone region in the centre of the tube plate needs to be coated. According to the invention, the erosiorn-protective coating can be applied to both new, not yet used base plates as well as to base plates, whose wall has been restored to the necessary thickness by build-up welding.
Furthermore, the invention concerns a method to coat a tube plate in a bundle of heat exchanger tubes. For this purpose the tube orifices are closed by plugs on the entry side tube plate. These plugs project from the tubes at least up to the thickness of the coating to be applied. Subsequently the packing material is applied. This can be carried out manually by spatula and trowel or by spraying. This is followed by mechanical compacting of the packing material by, for example, hammer blows transferred by a flat iron bar. After the setting of the packing material, usually at least after 24 hours, the plugs are removed and the packing material is possibly dried and baked.
The described packing materials are best suitable for coating base plates in bundles of heat exchanger tubes connected downstream of a thermal cracking installation.
The application of a coat to a base plate of a cracked gas cooler of an ethylene plans is described in the following in detail, wherein the procedure chosen for the application, the materials mentioned and the special case of application for a cracked gas cooler are to be understood not as limitations hut in the sense of an embodiment.
EMBODIMENT
V-anchors or ECO-VIN anchors, having the construction illustrated in FIGS. 1 and 2, made of authentic steel (1.4841), are welded. to a base plate. The internal tubes of the bundle of heat exchanger tubes are closed by tapered wooden plunges, so that the packing material is held both by the anchors and the plugs. The packing material, consisting of PLIRAM Cyclone-Mix D, is mixed with 2% by weight of corrugated steel fibres C-mix 25 (1.4841 material).
The application of the packing material is carried out manually with spatula and trowel. Following this the packing material applied is compacted section by section by hammer blows transferred by a flat iron bar to result in a cavity-free coating. After a setting time of approx. 25 hours at normal ambient temperature the tapered wooden plugs are removed.
The drying of the packing material and the subsequent baking is carried out according to a specified temperature graph following the manufacture's instructions.
By applying the coating, previously damaged base plates can be protected from further erosions The base plates coated according to the invention are subjected also to erosion by the coke particles. In comparison with the unprotected metallic material of the base plate, the erosion of base plates coated according to the invention is clearly slower, so that the availability of the corresponding plant parts is improved. Incidentally, when worn, a removal and renewed application of the coating according to the invention is possible.
By virtue of the good heat. insulating property of the coating the problem of the boundary temperature, mentioned in the introduction, is also diminished. This results in the further advantage that the metallic base plate does not need to be that thin, but can be made thicker. Due to the constructive stabilising resulting from this, the anchor bolts necessary for the stabilisation can be dispensed with, at least partly.
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Described is a heat exchanger comprising a nest of heat-exchange tubes held between two end plates, the heat exchanger being designed for connection downstream of a thermal-cracking installation. In order to reduce erosion of the base plate, the plate at the input end is coated on the side facing the oncoming gas with an erosion-resistant, fireproof coating of a chemically bound compound, leaving clear the apertures for the heat-exchange tubes.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. National Phase Application of International Application PCT/EP2012/061306 filed Jun. 14, 2012 and claims the benefit of priority under 35 U.S.C. §119 of German Patent Application DE 10 2011 078 132.3 filed Jun. 27, 2011, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to hub arrangements, in particular for twin wheels, with two hub parts that are rotatable relative to one another and associated braking arrangement.
BACKGROUND OF THE INVENTION
It is generally known and usual to provide axles with twin wheels on heavy-duty utility vehicles, for example on forklift trucks for large ship containers, in order to be able to guarantee extreme loading capacities. In this case it is desirable to arrange the twin wheels to be rotatable relative to one another in order to avoid undesirable slip during turning maneuvers of the vehicle and to avoid severe wear of the tyres of the twin wheels associated with this. U.S. Pat. No. 7,757,795 B2 shows a suitable hub arrangement for this type of twin wheels, in which the wheel hub parts carrying the two twin wheels are rotatably mounted on a (third) intermediate hub part, which on the other hand forms the input of a differential gear driving the wheel hub parts. For this purpose, gear wheels are arranged rotatable on an axially middle portion of the intermediate hub about axles which are perpendicular to the circumference of the intermediate hub part. These gear wheels mesh with toothing rings on the axial ends of the wheel hub parts facing one another, so that the wheel hub parts are only rotatable in directions opposing one another relative to the intermediate hub part. The intermediate hub part is driven via a planetary gear set and braked by means of a wet multiple disc brake. In order to be able to transmit to each wheel hub part a predetermined minimum driving moment or minimum braking moment, slide bearings which are subject to friction are provided in each case between the intermediate hub part and the wheel hub parts, while the differential arrangement additionally operates with friction predetermined by design as well.
All the same, this known hub arrangement is always problematic during braking manoeuvres when the twin wheels, because of road irregularities, are clearly loaded differently and have a correspondingly different traction. The same applies also when the twin wheels roll over road sections with very different friction coefficients. In all these cases it can happen that during a braking manoeuvre the twin wheel with good traction continues to roll largely unbraked while the twin wheel with poor traction slips with direction of rotation opposite to that of the former twin wheel.
A similar arrangement by design and function is the subject of U.S. Pat. No. 2,267,362. In this case, design measures for inhibiting the differential arrangement between the wheel hub parts are provided. In this connection it is utilized that gear wheels of the differential arrangement displace hydraulic lubricants in the differential arrangement in the manner of gear pumps. In this case, increased throttling resistances have to be overcome through design measures according to U.S. Pat. No. 2,267,362 so that the intermediate hub part during driving and braking operation transmits corresponding minimum moments to the wheel hub parts each. All the same, the case may arise under unfavorable conditions that the utilizable braking moments only have the (comparatively low) dimension of the aforementioned minimum moments.
EP 1 288 054 B1 shows the drive of the wheel hub parts of twin wheels via a differential arrangement. In this case, the wheel hub parts are each formed as a hollow wheel of a planetary gear set with planet wheels being rotatably mounted on a stationary planet carrier. The planet wheels each mesh with a sun wheel, which on the other hand is driven via one of the output shafts of the differential arrangement. No measures for transmitting braking forces onto the wheel hub parts are described whatsoever.
EP 1 145 894 B1 shows a twin wheel arrangement, in which the wheel hub parts can be non-positively coupled to one another and only one hub part is directly driven or braked. In this case, it must therefore be always ensured during braking maneuvers on a problematic surface that the wheel hubs are coupled together, which is technically difficult and associated with major construction effort.
EP 1 162 082 B1 on the other hand shows a twin wheel arrangement, the wheel hub parts of which are driven via a differential arrangement. In this case, the differential arrangement is combined with a step-down transmission on the input side in order to be able to transmit high driving moments to the output sides of the differential arrangement if required. No measures whatsoever for enforcing a synchronisation of the wheel hubs are shown.
SUMMARY OF THE INVENTION
This is where the invention starts in that at least each of two hubs is assigned a braking arrangement, which can be actuated jointly with the respective other braking arrangement.
In particular, it is an object of the invention to ensure with absolute safety, with a hub arrangement of the type stated at the outset, that on actuating the braking arrangement, braking moments of comparable magnitude become active on both hub parts.
According to the invention, this object is attained in that the braking arrangement comprises braking devices assigned to the hub parts, and in that on actuating the braking device assigned to the one hub part reaction forces that occur act as actuation force of the braking device assigned to the other hub part.
The invention is based on the general idea of discharging the forces, which are necessary for actuating the one braking device, to stationary parts via the other braking device. Thus, the two hub parts are necessarily braked jointly with comparable moments.
In the case of a hub arrangement provided for twin wheels, in which the wheel hubs are driven via a differential arrangement, the invention can also be realized in that the one braking device is assigned to a wheel hub part and the other braking device to an intermediate hub part of the differential arrangement.
Otherwise, it can be provided for driving the wheel hub parts to merely drive one hub part directly and to couple the other hub part to this hub part in a non-positive and/or positive manner when required.
With respect to further advantageous features, reference is made to the claims and the following explanation of the drawing, with the help of which a particularly preferred embodiment of the invention is described in more detail.
Protection is not only claimed for stated or shown feature combinations, but generally also for any combinations of the stated or shown individual features. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an axial sectional view of an embodiment of the hub arrangement according to the invention; and
FIG. 2 is an axial sectional view of a similar embodiment with additionally provided possibility of coupling the twin wheels when using the hub arrangement for said twin wheels.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular, the sectional images of FIGS. 1 and 2 each show “half sections”, in which only the region above a central axis 100 is shown and the region below this axis 100 is symmetrical to the shown section.
According to FIG. 1 , the shown hub arrangement comprises an axle tube 1 , which receives a drive input shaft 2 . On the left end of FIG. 1 , the drive input shaft 2 carries a sun wheel 3 which is positively connected to the shaft 2 , which sun wheel 3 meshes with planet wheels 4 in the manner known in principle, which circulate in a hollow wheel 5 provided with teeth on the inside, which is connected to the axle tube 1 in a rotationally fixed manner by means of a bell-like carrier 6 . The planet wheels 4 are rotatably mounted on axle journals of a planet carrier 7 , which on the other hand is connected to a hub part 8 in a rotationally fixed manner, which is rotatably mounted on rolling bearings 9 and 10 , which are arranged on the axle tube 1 or a cylindrical extension (not shown) of the hollow wheel carrier 6 arranged on the axle tube 1 .
The hub part 8 comprises a section 8 ′ supported on the bearings 9 and 10 and a section 8 ″ axially projecting beyond the bearing 10 . In this case, the left section 8 ′ serves for holding the rim 11 ′ of an outer twin wheel. The right section 8 ″ of the hub part 8 carries a further hub part 12 , which is rotatably mounted on the section 8 ″ of the hub part 8 by means of rolling bearings 13 and 14 arranged there. The hub part 12 has a same outer diameter as the hub part 8 in the region of the rim 11 ′. Accordingly, a same type of rim 11 ″ can be arranged on the hub part 12 for an inner twin wheel.
In FIG. 1 , at the right end of the axle tube 1 , a brake housing 15 , which is connected therewith in a fixed manner, is arranged. The brake housing 15 is open, on a side of the brake housing 15 , facing the hub parts 8 and 12 in such a manner that the outer circumference of the axle tube 1 and the edge of the opening of the brake housing 15 a ring opening is formed, through which the hub parts 8 and 12 with cylindrical axial end regions project. In this case, the axial end region of the hub part 8 or of the part 8 ″ project further into the brake housing 15 in axial direction than the axial end region of the hub part 12 arranged radially above.
Radially between the inner circumference of the brake housing 15 and the outer circumference of the axial end region of the hub part 12 or of the axial end region of the hub part 8 , brake disc packs 16 and 17 each are arranged. Each of brake the disc packs 16 and 17 include braking discs on the brake housing side, which in an inner circumferential toothing of the brake housing are arranged axially displaceably however in a rotationally fixed manner, and braking discs on the hub side, which are arranged in analogous manner on outer circumferential toothings of the axial ends of the hub parts 8 and 12 in a rotationally fixed manner, however axially displaceably. In this case, braking discs on the brake housing side and hub part side are alternately arranged in axial neighborhood in the known manner, i.e. a brake disc on the hub part side each is axially arranged between two braking discs on the brake housing side. Axially between the braking disc packs 16 and 17 , a ring plate 18 is arranged on the inner toothing on the brake housing side in an axially displaceable and rotationally fixed manner.
Within the brake housing 15 , an axially displaceable ring piston 19 is furthermore arranged. The ring piston 19 has a right end in FIG. 1 that is designed stepped in such a manner that, in the region of the piston step between the brake housing wall and the ring piston 19 , a ring chamber 20 is formed, which via a bore 21 can be controllably supplied with pressure fluid. The ring piston is thereby axially pushed against the brake disc packs 16 and 17 with corresponding force against the resistance of a resetting spring arrangement (not shown), wherein the axial pressure of the ring piston 19 exerted on the brake disc pack 17 is discharged via the axially displaceable ring plate 18 to the brake disc pack 16 and subsequently to the stationary brake housing 15 . As a result, both brake disc packs 16 and 17 thus effect braking, so that both hub parts 8 and 12 are simultaneously braked with the twin wheels 11 ′ and 11 ″ arranged thereon.
The embodiment of FIG. 2 differs from the embodiment of FIG. 1 initially in that the drive input shaft 2 and the hub part 8 are drive-connected to one another via a two-stage planetary gear set. The drive input shaft 2 on the other hand carries a sun wheel 3 which is connected to it in a rotationally fixed manner, which on the other hand meshes with planet wheels 4 , which on the other hand circulate in an internally toothed hollow wheel 5 . The planet wheels 4 on the other hand are rotatably mounted on axle journals of the planet carriers 7 . This planet carrier 7 is connected to a further sun wheel 31 in a rotationally fixed manner, which sun wheel 31 meshes with planet wheels 41 , which circulate in an internally toothed hollow wheel 51 , which like the hollow wheel 5 is stationarily held on the axle tube 1 via the bell-shaped carrier 6 . The hollow wheels 5 and 51 as a rule form a single hollow wheel, which has a corresponding axial width and accordingly interacts with an in the drawing right axial section with the planet wheels 4 and with an in the drawing left axial section with the planet wheels 41 . The planet wheels 41 are rotatably mounted on axle journals of a planet carrier 71 , which on the other hand is connected to the hub part 8 in a rotationally fixed manner.
Within the brake housing 15 , a first and a second ring piston 19 and 191 are arranged, wherein the ring piston 19 on the other hand can be pushed axially against the brake disc packs 16 and 17 through pressure loading of the ring chamber 20 , so that the hub parts 8 and 12 are necessarily braked simultaneously. The further ring piston 191 is pushed through springs 192 against the facing face end of the ring piston 19 in such a manner that the aforementioned brake disc packs 16 and 17 are again axially compressed and effect braking because of this. Through pressure loading a ring chamber 201 , which can be supplied with a pressure fluid via a bore 21 , the ring piston 191 can be shifted to the right against the force of springs 192 , so that the ring piston 19 is unloaded of the ring piston 191 and can merely impress the brake disc packs 16 and 17 effecting braking in axial direction when the ring chamber 20 assigned to the ring piston 19 is loaded with pressure fluid via the bore 21 . Through the shown double piston arrangement 19 , 191 , an automatic parking brake can thus be ensured on the one hand, when the ring chamber 201 is pressureless and the ring piston 191 axially presses against the ring piston 19 through the springs 192 . During driving operation, the ring chamber 201 is pressure loaded so that the ring piston 191 is held axially moved away or spaced from the ring piston 19 and the brake disc packs 16 and 17 only effect braking when the ring chamber 20 assigned to the ring piston 19 is loaded with pressure.
Otherwise, the possibility of positively coupling the hub parts 8 and 12 to one another is provided with the embodiment of FIG. 2 . To this end, a dog ring 50 is arranged axially displaceably but rotationally fixedly on the hub part 8 , and the hub part 12 is connected to a dog ring 51 in a fixed manner. These dog rings face one another with dogs arranged on the face end. The dog ring 50 can be axially pushed against the dog ring 51 against the force of a resetting spring 52 by means of a ring piston 53 , so that the dogs of the two rings 50 and 51 enter into engagement. The ring piston 53 is formed as a stepped piston on its side facing away from the dog ring 50 and together with a corresponding step-like (stepped) outer circumferential surface on the hub part 8 limits a ring space 54 , which via a bore in the hub part 8 which is not shown or a pressure lead-through in the axle housing which is likewise not shown can be loaded with pressure fluid or unloaded of pressure fluid, i.e. upon pressure loading of the ring space 54 , the dog ring 50 is brought to engage with the dog ring 51 , so that the two dog rings 50 and 51 and accordingly the hub parts 8 and 12 are positively coupled to one another. Upon pressure unloading of the ring space 54 , the resetting spring 52 shifts the dog ring 50 again into the shown left end position, in which the dog rings 50 and 51 are decoupled from one another and the hub parts 8 and 12 can rotate relative to one another. If required, the hub parts 8 and 12 and accordingly the rims 11 ′ and 11 ″ of a twin wheel arrangement can thus be simultaneously driven in synchronisation.
Deviating from the representation of FIGS. 1 and 2 , the hub 12 instead of via the rolling bearings 13 and 14 could also be rotatably mounted via the slide bearings on the hub 8 , so that the two hubs 8 and 12 always remain coupled to one another through a non-positive connection predetermined by the friction of the slide bearings.
With respect to the assembly of the rims 11 ′ and 11 ″ on the hubs 8 and 12 , FIG. 1 and FIG. 2 show an advantageous possibility of arranging rims 11 ′ and 11 ″ of twin wheels on axially adjacent hubs 8 , 12 with same outer diameters. For fastening twin wheels on the associated hubs 8 , 12 , lobe-like (lobe flanges or hub flanges) flanges are provided. Each of the hub flanges radially projects to the outside in a radial plane. The hub flanges are spaced from one another in circumferential direction. The rims 11 ′, 11 ″ have, on the inner circumferential side, lobe-like (lobe flanges or rim flanges) flanges which are substantially complementary to the hub flanges and are directed radially inwardly. The rim flanges are provided in such a manner that on the one hand the rims 11 ′, 11 ″, in a position that is concentric to the hub axis upon appropriate rotary position, are axially moveable over and beyond the radial plane and, on the other hand, the hub flanges on the hub side and the rim flanges on the rim side, upon suitable rotary position of the rim, can be placed onto one another for the fastening of the respective rim 11 ′, 11 ″ to the respective hub 8 , 12 .
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A hub arrangement has hub parts which are rotatable relative to one another. Each hub is assigned a braking device, which is actuatable jointly with the braking device of the respective other hub.
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FIELD OF THE INVENTION
The present invention relates to a method for producing tridimensional knitting goods.
BACKGROUND ART
Generally, with circular knitting and hosiery machines, efficient and aesthetically appreciable effects of tridimensional tricot are only obtained with the reciprocating movement of the cylinder needle, but this method greatly increases production costs. Alternatively, in the case of hose with the so-called pouch heel, which is known to those skilled in the art, the method enables similar results to be achieved, but with a significant loss in quality and yarn due to the presence of a great number of cut threads. More generally, in order to increase the value of some knitted goods, during the manufacturing process, various pockets or loops are added by subsequent cut and sew operation, so that the cost of the finished articles is greatly increased.
In addition, in the hosiery field, the presence of pockets or similar horizontal openings is widely unknown.
In everyday as well as in sports activities, are often required or necessary garments that are adapted to protect from impacts (shinpads in football, for example) or that are capable of meeting a higher standard in terms of practical use and comfort (such as multi-pocket jackets for hiking people, fishermen and hunters, or containers for golf clubs) and satisfying other needs of an aesthetic or functional character.
Taking into account the great development in the clothing field for sports and free time, knitted garments in general, socks in particular, have enjoyed little consideration as a possible support for innovations or more interesting functions; they are, yet, mere single-fabric or single-layer knitted tubes supplied with an elastic top: thus they still represent a mere or fortuitous thin wall between foot and shoe.
SUMMARY OF THE INVENTION
In recent years great interest was awakened when circular knitting machines of the full electronic type with differentiated diameters were introduced on the market, because the versatility of these machines enables a wide variety of semifinished knitted goods to be produced: brassieres, pants, dresses, trousers, skirts, bodies, bathing costumes, sports garments and still others. But, due to some inherent technical restrictions, among which lack of pockets, said knitted goods require additional labourious sewing operations for garment finishing. Otherwise, they merely remain without pockets and consequently less competitive.
That being stated, the invention intends to reduce or at least partly eliminate some of the above mentioned technical and production limits; with a production method having original economic, technical, aesthetic and commercial aims.
Consequently, it is a main object of the present invention to provide a method for producing knitted goods in general, hose in particular, having tridimensional effects, preferably fitted with at least one pocket automatically produced with the continuous movement of the cylinder needle. It is a further object of the invention to provide a method for producing knitted goods in general, socks in particular, also characterized by the presence of pockets formed of at least two layers or cloths, even adapted to be partly turned inside out.
It is an additional object of the invention to provide a method for producing knitted goods such as brassieres, pants, woollen underwear and knitwear, skirts, pants and technical items in general, characterized by the presence of at least one pocket or pouch. Another main object of the invention is to provide a method for producing knitted goods with at least one flounce formed of multi layers or fabrics and having the function of an inner lining.
The above mentioned objects are substantially achieved by a method for producing knitted goods, characterized by automatically producing on said goods at least one open pocket of multy-layer fabrics obtained with the continuous motion of a needle bed and with a prolonged but temporary and programmed exclusion of a suitable number of needles.
Further features of the invention and the advantages resulting therefrom will be more fully understood from the following description of some preferred but not exclusive embodiments of a method according to the invention now given by way of non-limiting example. The description will be taken with reference to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a structure of jersey knitted fabric material provided with a floating yarn;
FIG. 2 shows a knitted fabric obtained by working needles alternated with excluded needles;
FIG. 2 a shows a closed knitted flounce formed by two layers of cloths;
FIG. 3 is a front view of a knitted fabric provided with a series of short floating yarns;
FIG. 3 a is a sectional view of the fabric of FIG. 3;
FIG. 4 shows a side view of a sock obtained with the method of the present invention;
FIG. 5 is a front view of another sock obtained with the present method;
FIG. 6 shows a front view of the sock of FIG. 4 turned inside out;
FIG. 7 shows a tubular fabric with an alternative form of pocket;
FIG. 8 shows a side view of a sock having a pocket as wide as half the needle cylinder;
FIG. 9 shows in a more schematically way the pocket of FIG. 8;
FIG. 10 shows a pair of knitted pants provided with a pocket;
FIG. 11 shows a sweater provided with a pocket;
FIG. 12 shows a sweater provided with a series of pockets;
FIG. 13 shows a brassiere provided with two pockets;
FIG. 14 shows a body stocking with outer and inner pockets;
FIG. 15 shows a skirt or a pair of trousers provided with two side pockets.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention relates to a method which can find application in the field of the textile machines in general, and of knitting and of circular machines in particular.
Most of the description is made with reference to an essentially circular machine equipped with at least one needle bed or a cylinder rotating against stationary cams or vice versa, with at least one complete feed and therefore provided with: one or more yarn feeders; electronic or mechanical, or electromechanical needle selection, adapted to control the elements taking part in formation of the stitch or knitted fabric according to a pattern or working cycle.
Said circular knitting machine is additionally equipped with at least one dial provided with needles or hooks preferably to be selected by an electronic system or with the aid of usual cams adapted to select the jacks or needles butts, conveniently arranged. The invention is first embodied by preparing a jacquard pattern or motif, or information directed to the needles or jacks or other elements taking part in tricot formation, by a control or memory device or by electromechanical, magnetic, optical apparatus, or any other apparatus adapted for the purpose.
Contrary to the custom, an important part of said pulses or information is not sent to the needles or part of them, according to a defined scheme or program and according to the original pattern. This gives rise to exclusion from the tricot-formation process of the needles devoid of inputs or commands; this exclusion which may be complete or per defined regions, produces floating yarns instead of the loops, as Y in FIG. 1 .
Consequently, the knitted fabric tube is submitted to a structural deformation caused by a differentiated growing of the knitted fabric as a whole, adapted to preestablish tridimensional shapes of the fabric and suitable to conform to the human anatomy: sock heels and toes; or hips, bust, breasts, etc.
Said floating yarns can be further handled with some working needles duly spaced apart in said region of complete exclusion, with a dual purpose, i.e. that of reducing the floating yarn length and that of creating, if required, important interlacements of stitches.
Then by disposing some working needles in the concerned area and operating in a single or double (crossed) diagonal direction, braid-like effects are obtained, instead of the free floating yarns. This improves both the aspect and wearing quality of the knitted item, having said braids an aesthetic value of great effect, as F in FIG. 3 .
The invention is fully carried out by further handling said floating yarns and converting-them into a knitted fabric produced with only part of the needles present in the areas already defined as completely excluded from the tricot-formation process.
In this case the invention is accomplished by sending inputs or information to only part of the needles of the pattern areas previously already excluded, according to an established order.
For instance, only odd needles or only needles in alternating pairs will be excluded, i.e. in groups of three working needles followed by one or more excluded needles, etc.
The simultaneous presence of working needles and loops B, alternated with excluded needles and loops A, FIG. 2, over defined regions and for A relatively long time, (corresponding to a high number of stitch courses) is a sufficient and necessary premise for the production of a new fabric, formed by the working needles and relative loops B, but interrupted and also braided with the excluded needles and loops A, in order to produce a closed or open knitted flounce formed of two layers or cloths B 1 , FIG. 2, internally of the usual knitted tube. This fabric growing or additional flounce B 1 is characterised on the right side of the fabric by a perfect suture caused by elongation of the loops or needle stitches A out of work and therefore excluded from production of said flounce which can be repeated and varied both in height and in width.
In this case, the width is determined by the number of the excluded needles or the periodic entry and exit in the tricot-formation process of one or more needles or other movable elements taking part in tricot formation at the edges or vertical outer limits of the pocket, denoted by S in FIGS. 9 and 10.
The method hereinbefore described is shown in FIG. 4, referred to a sports sock 1 , seen laterally, with the usual elastic top 2 . In this case said flounce B 1 formed of two layers or cloths 5 and 6 , is placed internally of the knitted tube 4 and extends from top to bottom, i.e. from the work circumference 7 , being only partly interstitched with the outer knitted tube 4 , until 8 , i.e. an inner free welt that can be turned inside out, depending on circumstances.
At the upper portion 7 , flounce B 1 is interstitched only along half the needle cylinder, therefore the open area becomes a pocket or pouch 3 , disposed laterally, having an upper edge B formed of two layers that approximately extends over the second half of said cylinder.
The described configuration is illustrated in a different way in FIG. 6, in which sock 1 , slightly pressed at arrows F 1 and F 2 until it takes a downwardly cone-shaped configuration, shows flounce B 1 externally of the knitted tube 4 , drawn out of the pocket or pouch 3 of FIG. 4 . Interstitched close to the point denoted by X is about half of the inner flounce B 1 in FIG. 4, corresponding to the knitted area or interstitched circumference denoted by 7 and therefore opposite to pocket 3 .
In FIG. 6, the knitted fabric portion or flounce B 1 forming the inner circle W is practically internally of the knitted tube denoted by arrow Y 1 .
The inner portion of the knitted fabric circle W is produced with a lower number of needles than the outer portion denoted by B 1 . FIG. 5 shows an embodiment similar to the preceding one, with the difference that sock 1 is provided with a pocket 3 located at the shin and that a small central pattern or ornamental motif is added. FIG. 7 shows sock 1 produced in accordance with the invention with an alternative solution showing the pocket 3 and relative upper edge B turned upwardly.
In this case the inner flounce B 2 is turned inside out and up beyond the elastic top 2 ; the inner welt 8 of FIGS. 4 and 6 is completely turned inside out and up and this alternative solution causes reversal of the position of pocket 3 , which is a further hypothesis that, in addition to increasing flexibility of the invention, is particularly useful for other specific knitted items, in addition to socks.
In fact, looking at FIG. 7 in a reversed position, a very wide pocket or pouch may also be obtained which is ideal for knitwear items, with the additional advantage of the elastic top 2 . Shown again in FIG. 8 is the same sock 1 of FIG. 5, seen laterally with addition of holes H at the inner flounce B 1 interstitched with the outer cloth or layer for about half the needle cylinder, whereas on the remaining part flounce B 2 itself, open, forms a pocket 3 completed with the upper edge B.
Said holes H are created by the prolonged exclusion of some needles from the tricot-formation process. Practically, the effects of the pneumatic pulling action of the sock and the tensions of the loops or stitches still retained by the needles are combined together.
The sizes of said holes depend on the machine needles per inch, or gauge, the number of the excluded needles, the exclusion time and employed yarns count. By coordinating in an appropriate manner the various technical-textile factors, it is therefore possible to establish the final effect of holes H. An additional embodiment of the invention is shown in FIG. 8 concerning the anatomic conformation of heel T caused by the inner flounce located at the dashed area N-M coming out of the wide pocket 3 following the direction of the arrows. With the aid of mobile stitch cams controlled by a computer, the knitted fabric can be only widened in order to emphasize the shaping or anatomic conformation effect of the knitted fabric at the heel.
FIG. 9 is a sectional view of the configuration of pocket 3 and related upper edge B, formed of layers or cloths F 1 and F 2 concentric with the inner fabric F 3 .
Identified by 3 A is a hypothetical additional pocket the width of which is determined by the number of needles employed or by needles, or jacks, or hooks alternatively operating for the purpose, possibly housed in another needle bed. In order to implement the functions or the aesthetic aspect of the knitted item being the object of the invention, one or more floating yarns 7 can be inserted, by known techniques, within the flounce formed of layers F 1 -F 2 -F 3 , FIG. 9 . The invention development goes far beyond the hosiery field; in fact, FIG. 10 shows a pair of pants 30 produced with a circular machine of medium diameter with an elastic top 2 and a central pocket 3 delimited at lines S. In accordance with the invention, during knitting, that may indifferently take place either from the elastic top or from the opposite part, the usual work cycle is interrupted by the programmed exclusion of an appropriate number of needles retaining the relative loops, whereas the remaining needle part goes on production. The dashed portion 31 corresponds to the inner flounce which, knitted with appropriate yarns, in accordance with the invention, also performs the functions of an additional aesthetically-invisible body support or containment element.
FIG. 11 shows a different application of the invention concerning a sweater 20 fitted out with a main pocket 3 and a small pocket 3 A placed on one of the sleeves, preferably produced with a small diameter circular machine.
The embodiment in FIG. 12 shows a general knitted item 40 characterized by a series of multi-purpose pouch-like pockets, progressively denoted by 3 - 3 A- 3 B- 3 C. The item in FIG. 13 on the contrary shows a T-shirt or brassiere provided with two pockets 3 , obtained with an electronic circular knitting machine, according to the teachings of the invention.
In addition, these pockets can be further widened and, with the aid of selective stitch-forming cams, i.e. cams only operating at the knitted fabric region corresponding to the breast or pockets, the amount of stitches can be increased and the knitted fabric conformation can be modified in order to stress the shaping or anatomic conformation effect obtained by turning the inner fabric inside out, in the same manner as previously described for heel T in FIG. 8 .
The embodiment in FIG. 14 refers to a body stocking 50 fitted with a central pocket 3 produced in accordance with the present invention and obtained from an inner flounce 58 , as wide as area 55 . In this embodiment too the presence of one or more additional flounces 57 is provided and can be turned inside out or movable according to arrow F.
The relative band 56 , knitted with elastomer yarns, becomes a region for invisible anatomic support and containment. The knitwear item 70 in FIG. 15 diagrammatically shows a pair of trousers or a skirt fitted with pockets 3 and 3 A.
In the case of a skirt 70 , the inner flounce 71 duly lengthened or aesthetically enriched with known techniques (appropriate interlacements, yarns or knitted fabric structures) in accordance with the invention, automatically produces an additional cloth having a function of under-dress, petticoat or lining, which may be more or less visible or transparent, depending on the user's wishes. For best comprehension of the invention potentialities, some remarks on the presence and function of the previously described flounces are necessary; also because such flounces in other embodiments greatly characterize the knitted items. In fact, a plurality of additional inner flounces are provided, which may be different in height, width and thickness, and obtained by a differentiated growing of the fabric having different functions and aims, for a better comfort and protection.
Finally, increasing the solidity of the pocket object of the invention is possible by means of particular yarns, elastic, or provided with tiny hooks and eyelets, to be used only at the upper edge of said pockets and/or at the immediately-opposite knitted fabric region in order to achieve a better closure of the said pocket.
The wide flexibility of the invention enables the shape and functions of at least part of the present knitwear and hosiery production to be greatly modified, with the effects and results only partly described herein.
The proper use of the reciprocating movement within the scope of the invention also produces other original results such as hems or inner and outer borders, variously disposed.
The advantages of the invention are better emphasized with reference to the single drawings.
In FIG. 1 a structure of jersey knitted fabric is shown with a floating yarn Y produced by the complete absence of needles. FIG. 2 shows a knitted fabric obtained by working needles and loops B alternated with the excluded needles and loops A. This production providing differentiated growing of the knitted fabric produces an inner two-layer flounce B 1 , seen in section in FIG. 2 a . This flounce is variable in height and width. In FIG. 3 and 3 a it is shown, in front sectional view a series of very short floating yarns, corresponding to 3-4-5 needles alternated with selected needles disposed in a double and crossed direction. This interlacing aims at tying the floating yarns Y in FIG. 1 in order to obtain an aesthetically pleasant braid.
In FIG. 4 sock 1 is fitted with an elastic top; flounce B 1 , formed of cloths 5 and 6 , is at the inside of fabric 4 . Said flounce is half interstitched by the cylinder needles at 7 , whereas the second half is open and forms the side pocket 3 , with a two-layer upper edge B. The same sock 1 is further seen in FIG. 6 after taking the inner flounce B 1 out of said pocket 3 or turning it inside out. The fabric circle identified by W goes back to the inside of the knitted tube 4 , in the direction of arrow Y 1 . In FIG. 5 sock 1 is provided with a front pocket placed at the shin. This pocket, among other things, can be used as a container for plastics shinpads in sport activities or for other purposes requiring strong protection against impacts. An alternative form of pocket 3 , which is directed upwardly due to the reversed position of the inner flounce B 1 , in addition to the elastic top 2 is shown in FIG. 7 .
Sock 1 , shown in FIG. 8, represents a pocket or pouch 3 which is as wide as half the needle cylinder, whereas the second half of the knitted tube is characterized by a continuous series of horizontal holes H produced by distortion of loops as a result of a prolonged exclusion of the related needles from the tricot-formation process. The sock portion T, corresponding to the heel, is optionally produced in accordance with the invention; thus, the knitted fabric region within dashed lines M-N comprises the already described inner flounce and pocket 3 and the inner cloth partly comes out of it for achieving a wrapping effect.
This is obtained with the aid of computerized stitch cams, which are adapted to modify the loop thickness during tricot formation only for the needles corresponding to heel T. Pocket 3 of the preceding figure in a more diagrammatic manner, formed of cloths F 1 and F 2 which are opposite to and concentric with the inner cloth F 3 . Identified by 7 are the floating yarns inserted between the layers of the flounce and/or in the pocket. Identified by S are the outer limits of a hypothetical additional pocket.
Different pockets 3 - 3 A in pants and other knitwear items are shown in FIGS. 10 and 11.
Other embodiments concerning a knitted item with a series of multi-purpose pockets 3 - 3 A- 3 B- 3 C, are shown in FIG. 12 .
A brassière 60 with two pockets 3 is shown in FIG. 13, which pockets, if very wide, are capable of opening for turning inside out part of the inner cloth 61 thus a high wrapping effect. FIG. 14 shows a body stocking 50 with a central pocket 3 together with inner flounces 57 and 58 , at the respective areas 56 and 57 , to be widely used for additional effects of targeted anatomic containment. Longer as 71 it is an alternative solution for possible petticoats as in the case of skirt 70 in FIG. 15, also provided with two side pockets 3 and 3 A.
The present invention which is necessarily limited, offers wide margins of innovation to those skilled in the art, all falling within the scope of the invention.
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The invention relates to a method for producing knitted goods in general, hose in particular, with tridimensional effects or shaped goods, preferably fitted with at least one pocket automatically produced with the continuous motion of the needle cylinder. The usual knitted fabric production is modified by excluding, according to a preestablished order, sequences of needles (retaining the last loop or stitch) that are preferably alternated (1:1-2:2-3:1-etc.), even by groups. The knitted tube production goes on, even over several courses, with a differentiated growing, i.e. regions having full needles or ribs and regions having non-full needles or ribs, forming knitted layers or tubes ( 5, 6 ) concentric with the inner knitted tube folded upwardly and only partly interstitched or closed in the horizontal direction. The remaining part, which is open, corresponds to the two-layer pouch-like pocket, being the object of the invention.
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BACKGROUND
[0001] Technical Field
[0002] The present disclosure relates to a device for contraception in a man, in particular to a device for temporarily interrupting the sperm flow within the sperm ducts (ductus deferens or vas deferens) of a man.
[0003] Description of the Related Art
[0004] The options available to a man for birth control are the known condom, which still presents an element of risk, and the almost conclusive, but reliable, vasectomy. Vasectomy reversal is associated with a great deal of effort and is not always possible. This option is therefore usually chosen only after a man has had his desired number of children.
[0005] Recently, the number of men who have undergone a vasectomy years ago and now wish to have the vasectomy reversed due to a change in living situation has increased. According to press releases by various pharmaceutical companies, the development of hormonally active medicaments intended to influence the fertility of a man has been discontinued due to a lack of success.
[0006] Devices for temporarily interrupting the sperm flow are implanted in the sperm ducts in the man's scrotum.
[0007] U.S. Pat. No. 4,200,107 describes a cylindrical vascular connector which is fitted around the sperm ducts. U.S. Pat. No. 6,513,528 describes a silicone cylinder that is to be introduced into the sperm ducts. To subsequently reverse the sperm duct blockage, in both cases a further operation is required.
[0008] Patent application PCT WO 2010/047644 A1 describes a very complicated technical solution, in which the sperm-carrying ducts are blocked by a sleeve that has to be implanted, which sleeve constricts the ducts and is operated by means of a pump device that also has to be implanted. Said pump device is supplied with energy and controlled from outside through the skin of the user. To this end, a remote control and an inductive energy transmitter are also necessary. The implantation is associated with a great deal of effort since, inter alia, at least a spinal anesthesia is necessary to eliminate pain. This leads to high surgery costs and to an increased health risk for the patient. The large number of different mechanical, hydraulic and electronic components required for said device moreover increases the risk of technical failure, and further energy costs are incurred for operation of the device.
[0009] The patent DE 19909427 C1 describes a valve which is implanted in the sperm ducts of a man and can be felt through the user's scrotum and thus opened or closed by way of a switch lever. These valves are constructed in such a way that it is possible for the user himself to influence from outside his ability to conceive, without further surgical interventions.
BRIEF SUMMARY
[0010] Embodiments of the present invention provide a device for blocking the sperm duct of a man for the purpose of contraception, which device is improved in comparison to such devices from the prior art, particularly with regard to the valve switching.
[0011] The device according to embodiments of the invention will be referred to below as a sperm duct valve.
[0012] Disclosed is an implantable sperm duct valve for contraception in a man or male animal, for controlling the sperm flow in the sperm duct (“ductus deferens” or “vas deferens” in Latin) within the scrotum. It comprises a valve and two valve connection pieces which can respectively be attached to the testicular end and abdominal end of a sperm duct that has been severed beforehand, wherein the testicular sperm duct end is the end coming from the testicle (“testis” in Latin) and the abdominal end leads to the abdomen. The valve has a manual switch, by which on the one hand the switching state of the valve can be ascertained from outside by feeling or palpation and on the other hand a change between an open and closed state can be effected.
[0013] According to aspects of the invention, the sperm duct valve has a through-channel and at least one run-off channel, wherein the through-channel in the open state of the valve leads from the valve connection piece on the testicular sperm duct to the valve connection piece at the abdominal end of the sperm duct. In the closed valve state, the end of the through-channel facing towards the abdominal sperm duct end is closed. In this closed state of the valve, a run-off channel leads from the valve connection piece at the testicular end of the sperm duct out of the valve and into the body of the man.
[0014] In one embodiment of the invention, the switch of the sperm duct valve is configured as a rocker switch.
[0015] In another embodiment of the invention, the sperm duct valve has a release pin which first has to be actuated in order to open the valve.
[0016] Embodiments of the present invention have the advantage that, in the closed state of the valve, only the abdominal sperm duct end is closed, while the testicular sperm duct end is open and the sperm can continue to be transported unhindered from this end. In addition, the run-off channel or the plurality of run-off channels allows the discharging of sperm coming from the testicular sperm duct end, which sperm can thus flow out of the valve and the housing thereof and can pass into the body of the man. Therefore, by virtue of the valve according to embodiments of the invention, no build-up of the exiting sperm occurs in the region of the epididymis. Instead, sperm pass into the tissue in the scrotum and are broken down there by the body's own mechanisms. Current knowledge suggests that this has no pathological effects.
[0017] Since the risk of sperm build-up is now omitted, the sperm duct valve according to embodiments of the invention can be implanted in the sperm duct at any location in the region of the scrotum. It is no longer absolutely necessary for the implant to be placed so close to the epididymis. This has the advantage that the implant can be implanted by the surgeon at a location best suited to the patient.
[0018] Embodiments of the present invention provide a passive implant within the sperm duct (ductus deferens) in the scrotum of a man.
[0019] The implantation of the valve requires only a simple, low-risk, inexpensive, out-patient operation under local anesthesia, similar to a vasectomy, and can be performed by any trained urologist. As in the case of a vasectomy, the sperm ducts are severed and the resulting two ends of the sperm duct are pushed onto the connection pieces of the valve which are provided for this purpose, and are fixed thereto. The sperm duct valve is able to move freely along with the sperm duct attached thereto and the testes in the scrotum. The valve is generally used in pairs, since usually there are also two testes.
[0020] The valve is constructed in such a way that the switching state of the valve, that is to say open or closed, can be ascertained by the user himself, without further surgical intervention, by feeling (palpation) from outside, through the soft skin of the scrotum, and can if necessary be changed by actuating the rocker switch. When actuated, the mechanism in each case latches in a precise, secure and perceptible manner into a respective end position: open or closed. For example, the surfaces of the rocker switch are flush with the surface of the valve body in the respective open and closed valve positions.
[0021] The valve is directional. In other words, during the implantation, care must be taken to ensure that the abdominal end of the sperm duct valve is also attached to the abdominal end of the sperm duct and, in the same sense, the testicular end of the sperm duct valve is connected to the testicular end of the sperm duct.
[0022] To this end, as is customary in all technical valves, a marking of the flow direction is applied by means of an arrow. The applied arrow thus always points in the natural rising flow direction of the sperm towards the abdomen of the person in question.
[0023] It is possible to ascertain, by feeling, whether the valve is open or closed.
[0024] The valve is open when the surface of the rocker switch located on the abdominal side of the valve is flush with the valve body and the testis-side or testicular edge of the rocker switch protrudes from the valve body.
[0025] The valve is closed when the testis-side or testicular surface of the rocker switch is flush with the valve body and the abdominal edge of the rocker switch protrudes from the valve body.
[0026] In order to close the valve, the rocker switch protruding on the side of the valve pointing towards the testis is pushed towards the testis with a rolling movement. As a result, the edge of the rocker switch pointing towards the body or towards the abdomen becomes raised and the valve position is fixedly set in a latching manner.
[0027] In order to open the valve, the release pin at the lower corner of the valve pointing towards the testis is pressed and the rocker switch is pushed with a rolling movement towards the sperm duct leading to the body. As a result, the rocker switch becomes raised on the testicular side of the valve leading to the testis.
[0028] As in the case of a vasectomy, even in the closed state the man has an almost complete ejaculation since only the amount coming from the testes, around 3-5% by volume, is missing. The feeling and switching of the valve proceeds best when the scrotum is in a soft, stretched state. The scrotum serves the purpose of controlling the temperature for the testes. For optimal sperm iogenesis, the latter require a temperature of around 3° C. below the person's body temperature. If the ambient temperature is cold, the scrotum contracts in order to warm the testes. In warm to hot conditions, it becomes soft and stretches and increases its surface area in order to cool the testes. Prior to any desired switching of the sperm duct valve, therefore, the user should warm the testes region.
[0029] The selected switch position should logically be the same for both valves.
[0030] The sperm duct valve is not perceptible in the scrotum from outside since the sperm ducts always extend from the rear side of the testis.
[0031] Embodiments of the present invention provide a simple and reliable means by which a man can himself determine, at any point in time, whether he would like to become a father in a given living situation. In a heterosexual partnership, he alone is able to and can decide whether, when and after which time interval he would like to father a child. This is made possible for him by virtue of embodiments of the invention, since he simply flips the switch. He does not have to take any medicaments or hormones and there are no ongoing costs for him. His partner does not have to risk her health by using existing contraceptives. The man need never abstain from sex and/or use any paraphernalia or keep a supply of such paraphernalia. Embodiments of the invention disclosed herein provide a novel medical product for male contraception and therefore should or can be correctly called a “contra-generative”. This term does not yet exist in the nomenclature. Even this alone shows that in specialist circles it is assumed that birth control is a matter for women. This is because there are numerous options for contraception for a woman. However, the use of these means is still associated with risks and side-effects. Embodiments of the invention described herein is thus an alternative to the types of birth control known to date. It enables the man to have sole responsibility for birth control. It can be used universally due to the simplicity, the high degree of reliability, the extremely minimal side-effects and risks, and the low costs.
[0032] Exemplary embodiments and the advantages thereof will be explained in more detail in the following description, with reference to the figures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0033] FIG. 1 shows a schematic cross-section through the genitals of a man, illustrating the position of the sperm duct valve according to an embodiment of the invention in the sperm duct in the region of the scrotum.
[0034] FIG. 2 shows the view of the sperm duct valve according to an embodiment the invention in the open position, said valve being connected to the ends of a severed sperm duct. The flow direction of the sperm through the sperm duct valve from the testicular sperm duct end to the abdominal sperm duct is denoted by arrows and “Flow”.
[0035] FIG. 3 shows the sperm duct valve connected to the sperm duct ends as in FIG. 2 , but in the closed position. The flow direction of the sperm through the testicular sperm duct to the sperm duct valve is denoted by the arrows and “Flow”. The sperm flow through the abdominal sperm duct is interrupted by the rocker switch in the closed position.
[0036] FIG. 4 shows a vertical longitudinal section through the sperm duct valve in the open state.
[0037] FIG. 5 shows a vertical longitudinal section through the sperm duct valve in the closed state.
[0038] FIG. 6 shows a valve connection piece of the sperm duct valve for insertion into a sperm duct.
[0039] FIG. 7 shows the valve connection piece inserted in a sperm duct.
[0040] FIG. 8 shows the sperm duct with a widened valve connection piece.
[0041] FIG. 9 shows two valve cap halves ( 4 ) and the integration thereof with the sperm duct valve connection piece of FIGS. 6-8 .
[0042] FIG. 10 shows the assembly of the combination of sperm duct valve connection piece and valve cap halves, produced in FIG. 9 , with the sperm duct valve of FIGS. 2 and 3 .
[0043] In the figures, identical references have been used in each case for identical elements, and first-instance explanations relate to all figures unless mentioned otherwise.
DETAILED DESCRIPTION
[0044] The sperm duct valve 22 according to the example embodiment of the invention can be implanted in the sperm duct 16 , 17 in the scrotum 19 of a man, as shown in FIG. 1 . To this end, the sperm duct extending from the testis 20 is first severed, the end at the testicular part of the sperm duct 16 and the end at the abdominal part of the sperm duct 17 not being closed, as is the case for example in a vasectomy. In the diagram, the sperm duct valve 22 is implanted between the epididymis 21 and the vesicular gland (glandulae vesiculosa) 23 , but still in the region of the scrotum 19 . It need not necessarily be located close to the epididymis 21 . The sperm duct valve 22 consists of a valve body 1 having side walls 3 , valve connection pieces connected to the ends of the testicular and abdominal sperm ducts 16 and 17 , as well as a rocker switch 2 and a release pin 10 . Like the testes and the sperm ducts, the sperm duct valve is freely movable to a certain extent within the scrotum, according to any type of physical activity by the man. As shown in FIGS. 2-5 , the illustrated embodiment of the invention consists of a valve body 1 which serves to accommodate valve connection pieces 9 with valve caps 4 , said valve connection pieces being fitted laterally and opposite one another and being shown on the right and on the left in FIGS. 2 to 5 , as well as the rocker switch 2 and the other mechanical parts. The valve body 1 has for example the shape of a cuboid with rounded, in some cases significantly rounded, corners and edges on all sides. The rounding prevents any trauma to the surrounding tissue. The valve body 1 has for example a length of around 18 mm, a height of 10 mm and a depth of around 7 mm. However, dimensions of up to 50% larger are also conceivable. The smaller the valve, the greater the wearing comfort. However, the user friendliness of the rocker switch 2 then decreases, and vice versa. The specified dimensions have been tried by self-experimentation and have been confirmed to be a good compromise.
[0045] Most parts are preferably made of implant plastic, such as for example PEEK, and are worked by micro-injection molding and/or CNC milling. The valve connections 9 may be made of metal alloys, such as for example titanium alloys (for example nitinol) or a suitable implant steel (for example the material 1.4441/316 LVM), or of plastic or of a combination of both types of material. However, the lattice-type small tube 9 c may also be made for example of metal and may be incorporated by means of injection molding into the parts 9 b and 9 a made of plastic for example. The necessary compression springs may be made of implant spring steel or platinum alloys.
[0046] The valve body 1 has, in the top third in the longitudinal direction, a through-channel 1 a having a diameter of around 0.7 mm, which extends through the rocker switch 2 and the valve connection pieces 9 and through which sperm can flow in the open state of the valve. Located at the end sides of the cuboid-shaped valve body, axial to the through-channel 1 a, are wedge-shaped cutouts 1 d and circular cutouts 1 e for receiving the valve caps 4 and stepped bores 1 b for receiving the valve connection pieces 9 during implantation. Located transversely to the through-channel 1 a and extending from the large flat surface 3 of the valve body is a large stepped bore which is perpendicular to the through-channel 1 a , said large stepped bore having for example a diameter of 12 mm and a depth of 5 mm. Located in the same axis and in the bottom of the large stepped bore is a smaller blind bore having for example a diameter of 2 mm and a depth of 0.7 mm. This small blind bore serves to receive and rotatably mount the rocker switch 2 . The large stepped bore intersects the upper edge of the valve body, as a result of which the installed rocker switch 2 protrudes from the valve body. Located in the bore wall in the lower region of the stepped bore are two identical cutouts 1 c which are mirror-symmetrical to one another and each have the shape of at least one segment of a circle. These serve as a guide and stop for a sprung wheel axle 7 which brings the rocker switch 2 into the two end positions. The wheel axle 7 provides for the switching of the rocker switch 2 . It has the shape of a dumbbell. In the region of the axle, it is pressed by means of the axle spring 13 , which is a normal compression spring, out of its guide in the rocker switch 2 . The pair of wheels on the axle must thereby automatically follow the shape of the cutouts 1 c in the valve body 1 and thus force the rocker switch 2 into the respective end stop for “open” or “closed”. The valve can thus assume only a fully closed or fully open state.
[0047] Located in the left-hand bottom corner, at an angle of for example 40° to the through-channel 1 a, there is a continuous stepped bore and a wedge-shaped cutout for accommodating a securing device consisting of the release pin 10 , a release pin spring 15 and a securing plate 14 .
[0048] Due to the bores and rounded areas, the cuboid-shaped valve body 1 has a sickle-shaped main surface. Located on this narrow edge are a plurality of, for example 6 , cylindrical pins. The valve body 1 can thus be connected to the valve cover 3 for example by means of ultrasonic spot welding. The valve cover 3 thus closes off the entire valve technology with respect to the outside.
[0049] The rocker switch 2 has the shape of a cylinder of small height, the cylinder jacket of which faces towards the valve connections, with a cylinder bottom and cylinder top which are oriented parallel to the side walls 3 of the valve body. The cylinder jacket of the rocker switch 2 has a cutout with surfaces 2 a and 2 b, which extends over barely one-quarter of its circumference. The cutout in the rocker switch 2 thus consists of two surfaces 2 a and 2 b which are perpendicular to the cylinder bottom and cylinder top and form the angle of the cutout, for example 140°. In the open position of the valve 22 , the surface 2 b is flush with the valve body 1 while the surface 2 a protrudes from the valve body. In the closed position, the surface 2 a is flush with the body while the surface 2 b protrudes. In addition, the surface 2 a is located close to the testicular inlet end of the valve (in FIGS. 2-4 , the inlet end of the valve is denoted by the arrow “Flow” pointing into the valve), said surface running flush with the valve body at the inlet end when the valve is closed. In a corresponding manner, the surface 2 b is located close to the abdominal outlet end of the valve and runs flush with the valve body at the outlet end of the valve when the valve is open. (In FIGS. 2 and 4 , the outlet end of the valve is denoted by the arrow “Flow” pointing out from the valve.)
[0050] The rocker switch 2 is rounded on all sides and has a plurality of bores. Among these, a first bore 2 c leads parallel to the cylinder top and cylinder bottom and through the center of the cylinder 2 and parallel to the surface 2 b. This bore enables sperm to flow when the valve 22 is open, and to this end accommodates sliding tubes having an outer seam 5 and a sliding tube having an inner seam 6 , which are pressed outwards by a compression spring 11 . As a result, a passage for the sperm which is sealed off from the outside is provided in the open state of the sperm duct valve 22 as a result of the spring and the suitably curved geometry of the outer end faces of the sliding tubes 5 and 6 and the bores 5 a and 6 a thereof together with the through-bores 1 a in the valve body and the bore 9 a in the valve connection piece 9 . Further bores 2 d and 2 f likewise extend parallel to the cylinder top and lead from a first opening on the cylinder jacket in the region of the inlet end 4 a of the valve, axial with the opposite stepped bore 2 g of the valve, and from a second perpendicular bore in the surface 2 a into the interior of the rocker switch 2 , wherein the bores 2 d and 2 f meet at a point of intersection. A further bore 2 e intersects this point of intersection at right angles to said bores 2 d and 2 f and is aligned with a bore on the side of the valve 22 which leads to the outside. In the closed state of the sperm duct valve 22 , the bore 2 e is also aligned with a bore 3 a in the valve cover 3 and a bore in the wall of the valve body 1 located precisely opposite the latter. The aforementioned bores serve to convey sperm away to the outside and into the interior of the scrotum 19 when the valve is closed.
[0051] The two surfaces 2 a and 2 b form the touch surfaces for switching the valve 22 . When the surface 2 b for “open” is pressed, the rocker switch 2 rotates in the valve body 1 through a predefined angle, for example 40°, and securely latches at this position. Pressing on the other surface 2 a for “closed” causes the rocker switch 2 to spring back through 40° in the other direction. The rocker switch 2 accommodates in a blind bore 2 g a blocking pin 8 and a pin spring 12 as sealing elements. The bore axis of the stepped blind bore 2 g for accommodating the blocking pin 8 and the pin spring 12 extends parallel to the surface 2 a “closed” and crosses at right angles the longitudinal axis of the cylindrical rocker switch 2 . The sliding tube arrangement with bores 5 a and 6 a is located in a position rotated through the same predefined angle, for example 40°, relative to the bore axis for the blocking pin 8 and thus parallel to the surface 2 b “open”.
[0052] Located in a further bore 2 h, which is diametrically opposite the surface 2 a and 2 b, is the wheel axle spring 13 which pushes the wheel axle 7 out of the rocker switch 2 and ensures the latching effect. To this end, the wheel axle 7 is guided in precisely dimensioned guide grooves in the rocker switch 2 in the region around the bore 2 h. Additionally arranged in the valve body on this side of the rocker switch 2 are two cutouts 1 c , in which the sprung wheel axle 7 is received with little play and with a precise displacement travel. The cutouts, on the sides thereof facing towards the connection pieces, are shaped as a segment of a circle so that the wheel axle 7 is arrested there. The cutouts 1 c, on the side thereof facing towards the middle of the valve, each have a surface angled upwards towards the rocker switch 2 , said surfaces meeting in the center line of the valve 22 .
[0053] In the closed position of the valve, the wheel axle 7 is held in the outlet-side cutout 1 c (on the left-hand side in the figure), and when the valve 22 is switched the wheel axle is moved into the inlet-side cutout 1 c and is held therein (on the right-hand side in the figure). The sliding tube with the outer seam 5 and the sliding tube with the inner seam 6 , which are mounted in the rocker switch 2 , are manufactured in such a way that they can be inserted into one another and pushed out of one another by means of the compression spring 11 , which is a normal compression spring. This seals off the through-channel 5 a and 6 a from the through-channel 1 a of the valve body 1 . The outwardly protruding ends of the sliding tubes to this end additionally have a curved geometry which corresponds to the shape of the large stepped bore in the valve body 1 . When the valve is open, the sliding tube arrangement extends in the same axis as the valve passage. When the valve is closed by rotating the rocker switch 2 through 40°, the opening of one sliding tube points outwards into free space. The other sliding tube latches into the bore of the securing plate 14 at the bottom right-hand side. When the valve is to be closed, the release pin must first be pressed from below counter to the resistance of a release pin spring 15 . Only then can the valve at the same time be opened. Like the sliding tubes, the release pin 10 has a through-bore 10 a and in the closed state of the valve allows the cavities to be filled with the body fluid of the sliding tubes. A securing plate 14 is an inwardly curved trapezoidal plate with a stepped bore and is pushed into the corresponding cutout in the valve body 1 during assembly of the valve following the insertion of the release pin 10 and the release pin spring 15 . The release pin spring 15 may be configured as a multi-component plate spring or as a normal compression spring. With the plate spring variant, a click effect can be achieved which indicates that the release pin 10 has been released.
[0054] The actual stoppage of the sperm flow, by the closed valve, is ensured by the blocking pin 8 . As the valve is closed, said blocking pin is pushed in front of the abdominal through-hole in the valve interior, that is to say the outlet opening of the valve in the region of the outlet end thereof. Correspondingly, the outlet end in FIG. 5 in the blocked scenario is denoted by an arrow “Stop”, wherein the sperm nevertheless flow off through the run-off channel 2 f, 2 e and 2 d. The blocking pin 8 is pressed against the large stepped bore wall of the valve body by means of the pin spring 12 , which is a normal compression spring, and on the surface which makes contact with the valve body 1 has the same curved geometry. In this way, the sperm duct valve 22 does not require any elastic sealing materials which are subject to wear. It does not lose its sealing effect over a long period of use, as is usually the case with valves. By virtue of the low friction in the region of the path described by the blocking pin on the valve body 1 , both sides actually grind into one another and accordingly an increasingly improved sealing effect is achieved. Then again, given the low switching frequency of probably less than 10 times over the lifelong period of use, the expected wear is negligible.
[0055] For a sperm having a head diameter of around 3.5 micrometers, there is no way through this barrier, especially since the sperm in the region of the sperm duct are still within an acid barrier, in other words are themselves unable to move.
[0056] A cylindrical journal (not shown) on each side of the rocker switch 2 serves as the rotation axle, precisely in the mid-point of the rocker switch 2 , said cylindrical journals protruding from the surface of the cylinder top and cylinder bottom. The journals enter the blind bores (not shown) of the valve body on one side and the blind bore of the valve cover 3 on the other side.
[0057] The valve cover 3 is in principle a mirror image of the large side wall of the valve body. After assembly, it closes off the entire mechanism from the outside. To this end, it has a plurality of, for example 6 , bores 3 b for receiving corresponding pins on the valve body 1 , in order to be able to be welded to the latter with a precise fit. Alternatively, however, the valve cover 3 could also be screwed to the valve body 1 or connected to the valve body 1 by latching.
[0058] As shown in FIGS. 6-9 , the valve connection pieces 9 have a large flange 9 b which, during implantation, is clamped by the two-part valve cap 4 in the grooves 4 a of the latter. Located on the connection-side direction of the valve body 1 is a cylindrical connector which, during assembly of the unit consisting of sperm duct 16 / 17 , valve connection 9 and the two-part valve cap 4 , can be plugged into the bore 1 b of the valve body 1 as shown in FIG. 9 . Located on the opposite side is a thin-walled small tube 9 c for holding the respective sperm duct end. The valve connection piece 9 has a continuous opening which leads through the connector, the flange and the small tube and ensures the flow of the sperm. In one embodiment of the invention (not shown), the small tube 9 c has a plurality of fine conical graduations, as in the case of a hose fitting. During implantation, a plurality of finely graduated different internal diameters of the small tube are available for the purpose of adapting to the sperm duct. In a further embodiment of the invention, the small tube 9 c is provided with a lattice-like structure in the outer surface. As in the case of a stent, the lattice structure is compressed somewhat prior to implantation. Moreover, this end is also sheathed with a thin silicone layer (not shown), for example a silicone hose or a similar elastic inert material, in order to ensure the sealing of the inner sperm duct mucosa to the valve connection piece 9 in the region from 9 c to 9 b. Once the valve connection pieces 9 have been inserted into the sperm ducts 16 , 17 , they are widened from inside onto the nominal inner mass. This takes place by pulling an elongate, needle-like element 18 with a wedge-shaped head out of the valve connection piece 9 .
[0059] The valve connection piece 9 with a minimal external diameter can thus easily be inserted into the small lumen of the sperm duct. By means of special pliers (not shown), similar to the principle of blind riveting pliers, the element 18 is pulled out of the valve connection piece 9 and slightly widens the lumen of the valve connection in the region of the lattice structure together with the sperm duct 16 , 17 itself.
[0060] Another variant of the widening of the lattice structure of the valve connection piece 9 is also possible using the reverse principle by pressing inwards a cylindrical mandrel having a conical tip, instead of the illustrated embodiment 18 , with the aid of similar special pliers which are likewise not shown.
[0061] By virtue of their bulging rounded shape, the hollow-cylindrical valve caps 4 protect the sperm ducts 16 , 17 against piercing by the valve connections in the event of extreme movements. The outer surfaces of the valve caps 4 are provided with bores all around, through which the sperm duct ends always remain in contact with the natural fluid of the surrounding tissue and enable substance exchange. A valve cap 4 consists of two halves which are provided with hooks 4 d and cutouts. By virtue thereof, the two halves can be plugged together and at the same time the valve connection piece 9 can be fixed therein.
[0062] When plugged together, the two halves form a hollow cylinder. On the side facing towards the sperm duct 16 , 17 , it has a large rounded edge and an inwardly directed bead. The internal diameter of the bead should correspond to the external diameter of the sperm duct. Facing towards the valve, the valve caps 4 have in the interior a groove 4 a for receiving a flange 9 b of the valve connection 9 . To this end, use is made of special pliers (not shown) which are provided with a holding device for the valve cap halves 4 . The two halves can thus be pressed together in a secure, precise and forceful manner. The valve cap halves 4 latch into one another.
[0063] Microneedles 4 e are also incorporated in the halves. Said microneedles are arranged in such a way that they pierce the muscular walls of the sperm duct tangentially when the valve cap halves are pressed together, and enter holes formed on the opposite valve cap half 4 without exiting from the other side thereof. This ensures a secure connection of the sperm duct valve to the sperm duct 16 , 17 without restricting or jeopardizing the blood supply to the sperm duct through strangulation or any other suture. The large flange of the valve connection piece 9 embeds in the internal groove 4 a of the valve cap halves 4 .
[0064] Finally, the resulting unit consisting of connection piece 9 , sperm duct 16 , 17 and valve cap halves 4 is plugged into the sperm duct valve. By virtue of the hooks 4 f, it likewise latches therein into the latching elements 1 d and the circular groove-like cutout 1 e of the valve body 1 . The described steps in FIGS. 6 to 10 take place both with the abdominal sperm duct end 17 and with the testicular sperm duct end 16 . A non-releasable connection of the sperm duct to the valve is thus obtained. This connection could also be constructed in such a way that it can be released again by means of a further special tool.
[0065] Inert materials are preferably used for the sperm duct valve according to embodiments of the invention. The surfaces of the individual parts thus require no anti-adhesion coatings and medicaments to avoid rejection reactions of the human body.
[0066] In one embodiment of the invention, a surface treatment which is limited to individual parts or is widened to all parts of the sperm duct valve 22 is optionally provided for the aforementioned purpose.
[0067] In order to be able to react to the different anatomical dimensions of the sperm ducts 16 , 17 of different men, the valve connections 9 and valve caps 4 are accordingly manufactured in different sizes. The surgeon can thus choose the appropriate size during implantation. The valve body 1 itself, along with the internal parts, could always remain the same size. An implantation of the sperm duct valve according to aspects of the present invention is thus also suitable as an alternative to a vasovasectomy when the two sperm duct ends 16 , 17 of a sperm duct have different dimensions, as is often the case after a vasectomy that took place years earlier.
[0068] Upon closing the sperm duct valve, the user is not sterile immediately but rather only after weeks to months. This need not be viewed as a disadvantage. Once pregnancy has been achieved for example in a partnership where there is a desire for children, the valve is closed. The user is then sterile at the latest at the time the child is born, that is to say around 9 months after conception. Further contraceptive measures by the woman or the man are no longer necessary. Only when there is a desire for a further child, for example after 2-4 years, will the sperm duct valves be opened. Things then happen more quickly. Sperm could be detected in the ejaculate for example after 4 weeks or already at the time of first ejaculation after implantation of the newly developed sperm duct valve, even though the man had previously been sterile for a year.
[0069] Apart from the condom, all male contraceptives, including medicaments and also the invention described herein, have the disadvantage that the user is not sterile immediately after activating the blocking function or taking the medicament. Sperm may still remain for weeks or months in the organs downstream of the respective device, such as the prostate gland 25 (Prostata) and the vesicular gland 26 (Glandulae vesiculosa), and may trigger undesired fertilization with an ejaculation during sexual intercourse.
[0070] It is therefore advisable to have the desired sterility scientifically confirmed beforehand by means of a sperm iogram.
[0071] In addition, these methods do not protect against infectious diseases. Aspects and features of the embodiments described above may be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.
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The disclosure relates to a vas deferens valve for contraception for use in a man and for implanting in the vas deferens within the scrotum, enabling the regulating of sperm flow in the vas deferens. There is a manually activated rocker switch which can be activated through the skin of the scrotum and which has a through-channel which, in the opened state, leads from a valve connection piece on the testicular vas deferens to a valve connection piece on the abdominal end of the vas deferens and, in the closed valve state, can be blocked on the end of the through-flow channel which faces the abdominal vas deferens end. The valve additionally has at least one outlet channel which, in the closed state of the valve, leads from the valve connection piece on the testicular end of the vas deferens out of the valve to the outside in the body of the man.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. nationalization under 35 U.S.C. §371 of International Application No. PCT/US2013/065525, filed Oct. 17, 2013, which claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/714,916, filed Oct. 17, 2012. The disclosures set forth in the referenced applications are incorporated herein by reference in their entireties.
BACKGROUND
The present disclosure includes a hinge assembly for use in a hinged attachment of a panel relative to a frame and providing movement of the panel relative to the frame. A link which provides an extension or reach motion and positioning of the assembly, shown for purposes of illustration and not limitation in the form of a gooseneck arm, is provided in the hinge assembly to facilitate an extended range of motion of the hinge assembly. A first spherical bearing assembly and a second spherical bearing assembly are operatively associated with a bearing end of the link to provide multiple degrees of motion while securely retaining the panel relative to the frame. The hinge is intended to provide universal application of a single version of a hinge which can be used in multiple locations as facilitated by the multiple degrees of motion provided by the bearing end of the link.
By way of background, a variety of gooseneck hinges have been developed for attachment of a panel or door to a frame. Such gooseneck assemblies provide a plate and flange attached to a frame with a gooseneck arm pivotally attached to the flange. A point of rotation allows the arm to move relative to the flange. The arm generally extends along a predefined path and includes attachment points such as a corresponding plate and flange assembly on an end distal from the frame end attached to the flange. The distal end of the arm is attached to the panel at a specific location so that when the panel is closed relative to the frame the gooseneck can retain the hinge end of the panel. Often times a latch assembly is positioned spaced from the hinges to provide a locking feature to retain the panel in a closed position over the opening defined by the frame.
Some gooseneck hinges are provided with a locking mechanism to allow the hinge to lock in an open position once the panel is displaced relative to the frame. This allows the panel to be held by the hinges in an open position. The locking feature of the gooseneck hinge can be useful to further reduce the number of parts that are required in an assembly. It may be useful to reduce the number of parts because it can decrease initial installation time and can reduce the cost associated with the hinge assembly maintenance, and repair. As an example, prior art designs may have used a separate hold open rod to hold the panel in the open position relative to the frame once it is displaced to the open position. The use of a locking mechanism associated with the hinge helps eliminate such a hold open rod assembly space use, installation, cost, weight, and maintenance.
As an additional matter, some prior art hinge assemblies are custom designed for each specific application. In this regard, multiple hinge assemblies may be designed to hold and hinge a single panel. Other hinge assemblies can be designed for other panels. However, it would be useful to reduce the number of parts managed, parts inventories maintained, and increase the number of parts bought by having a single more universal hinge assembly which can be used for a variety of panel and frame assemblies. In this regard, it would be useful to provide a hinge assembly which increases the degree of motion to facilitate movement of the panel relative to the frame thereby facilitating the use of a single type of hinge for multiple applications. The use of a gooseneck hinge can be useful in this application because it can provide extended displacement of the panel relative to the frame.
This background information is provided to provide some information believed by the applicant to be of possible relevance to the present disclosure. No admission is intended, nor should such admission be inferred or construed, that any of the preceding information constitutes prior art against the present disclosure. Other aims, objects, advantages and features of the disclosure will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will be described hereafter with reference to the attached drawings which are given as a non-limiting example only, in which:
FIG. 1 is a perspective view to illustrate a panel in a closed position over an opening defined by a corresponding body portion, the body portion being a section of an aircraft with the panel being displaceable on a hinge assembly disclosed herein to facilitate access to areas within the body of the aircraft;
FIG. 2 is an illustration showing the panel displaced relative to the body to provide an opening facilitating access to the inside of the aircraft for a variety of purposes including such activities as maintenance of components retained within the aircraft;
FIG. 3 is a perspective view of the hinge assembly showing a frame mounting portion, a link in the form of a gooseneck arm portion, and a panel mounting portion with a latch retained relative to the frame mounting portion for facilitating retaining the hinge in an open position;
FIG. 4 is an illustration of the latch as shown in FIG. 3 which has been displaced to rotate a bearing end of the gooseneck arm relative to the frame mounting and showing displacement of the panel away from an opening defined by the frame with the latch assembly retaining a portion of the bearing end;
FIG. 5 is an exploded perspective view of the components of the hinge assembly showing the various specific components comprising the frame mounting, bearing assembly carried on the bearing end of the gooseneck arm, a panel mounting portion, and the latch assembly;
FIG. 6 is a cross-sectional side elevational view taken along line 6 - 6 in FIG. 3 showing the relationship of the various structures of the hinge assembly; and
FIG. 7 is a cross-sectional view taken along line 7 - 7 in FIG. 3 providing additional information about the relationship of a first spherical bearing to a second spherical bearing which helps facilitate multiple degrees of motion of the bearing end to facilitate movement of a panel attached to the mounting end of the gooseneck arm.
The exemplification set out herein illustrates embodiments of the disclosure that are not to be construed as limiting the scope of the disclosure in any manner. Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.
DETAILED DESCRIPTION
While the present disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, embodiments with the understanding that the present description is to be considered an exemplification of the principles of the disclosure. The disclosure is not limited in its application to the details of structure, function, construction, or the arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of various phrases and terms is meant to encompass the items or functions identified and equivalents thereof as well as additional items or functions. Unless limited otherwise, various phrases, terms, and variations thereof herein are used broadly and encompass all variations of such phrases and terms. Furthermore, and as described in subsequent paragraphs, the specific configurations illustrated in the drawings are intended to exemplify embodiments of the disclosure. However, other alternative structures, functions, and configurations are possible which are considered to be within the teachings of the present disclosure. Furthermore, unless otherwise indicated, the term “or” is to be considered inclusive.
As shown in FIGS. 1 and 2 various aircraft and other devices have an outer portion or body which may be interrupted, as needed by design, to provide access to equipment and other systems located within the body 20 . In such circumstances, the body is formed with an opening 22 which may be defined in general by a frame element 24 having a panel 26 being used to close the opening 22 . FIG. 1 shows the panel 26 in a generally closed position over the opening 22 . FIG. 2 shows the panel 26 displaced from the opening 22 showing the panel oriented in an open position. In the closed position a latch or other locking device 28 alone or in combination with other similar systems is used to retain the panel in the closed position. As shown in FIG. 2 , one or more hinge assemblies 30 may be attached to the panel to retain it relative to the frame 24 . The hinge assemblies 30 facilitate displaceable retention and movement of the panel 26 relative to the frame 24 . With further reference to FIGS. 3 and 4 , the hinge assembly 30 is shown in a closed position ( FIG. 3 , analogous to FIG. 1 ) and an open position ( FIG. 4 , analogous to FIG. 2 ). These structures and functions of the hinge assembly 30 will be described in greater detail herein below.
As shown in FIGS. 3 and 4 , the hinge assembly 30 includes the frame mounting portion 34 and a panel mounting portion 38 . A link 42 is illustrated in the form of a gooseneck arm. References is broadly made to the link 42 so that the broadest possible interpretation of the structure moveably attached to the frame mounting 34 and attached to the panel mounting 38 can be defined in the present description. While a “gooseneck” structure can be used, a variety of other configurations presently known or hereafter developed are also considered to be appropriate for the link 42 . While the link 42 is illustrated as a single component it is possible that a multipiece link which is fixed or articulable could be used While the following description will make reference to the link 42 as being a gooseneck configuration the structure is intended to be interpreted in the broadest possible manner and is provide as an illustration but not a limitation of the present invention.
Similarly, while the panel mounting portion 38 is typically a pair of brackets 46 attached to a distal end 50 of the link 42 other variations on the panel mounting 38 can be envisioned. As such, the panel mounting portion, while shown as being a fixed element could be any version of elements required to achieve the structural and functional objections of the hinge assembly 30 . As such, the panel mounting portion 38 as shown herein is provided by way of illustration and not limitation.
The frame mounting portion 34 includes a pair of frame brackets 54 which are defined by corresponding pairs of slate 58 and extending flanges 60 . The flanges include mounting passages 152 for a shaft 64 extending from one flange to the other flange providing an axis 68 of attachment and movement relative to the frame bracket 54 . As will be described in greater detail below, a first spherical bearing assembly 70 is carried on and moves relative to the shaft 64 along the axis of attachment and movement. The spherical bearing assembly 70 includes the end of the link at the bearing end 74 which provides structure to house and retain a spherical bearing 78 .
A second spherical bearing assembly 82 is spaced from the first spherical bearing assembly 70 . The second spherical bearing assembly 82 includes a shaft 88 extending through the bearing assembly 82 . A pair of generally arcuate passages 90 are defined in the corresponding flanges 60 , 60 of the corresponding frame bracket 54 , 54 . The shaft 88 helps maintain the position of the link 42 relative to the frame mounting assembly 34 .
As noted above, the first spherical bearing assembly 70 is retained along the axis of attachment and movement 68 . As such, a degree of side to side movement or angular movement of the link 42 is facilitated by the bearing assembly 70 . This helps to allow the hinge attached to the panel 26 to be securely retained relative to the frame 24 but to provide a degree of linear as well as angular displacement movement of the panel 26 relative to the frame 24 .
The second spherical bearing assembly 82 similarly provides a degree of movement but generally limits movement to translational movement along an axis 94 extending through the shaft 88 associated with the second spherical bearing assembly 82 . The combination of the first and second spherical bearing assemblies provides a degree of movement or articulation of the hinge which compensates for panel contours relative to the frame assembly. For example, if a panel provides a variety of contours the movement of the hinge may not merely be along a linear path. Rather, movement of the panel relative to the frame using the hinge may require more complex adjustable movements during the opening and closing of the panel relative to the frame. The hinge assembly as disclosed herein accommodates the variations associated with panels and frames. Also, the use of the hinge as disclosed facilitates use of a single type of hinge with a variety of panels having a variety of contours.
The hinge assembly 30 as described herein also includes a latching feature which allows the hinge to be latched in an opening position (see FIGS. 2 and 4 ) thereby eliminating the need for an additional structure to maintain the panel 26 in an open position relative to the frame 24 . In this regard, the shaft 88 includes ends 98 which extend beyond the outboard surfaces of the corresponding flanges 60 . These ends provide a structure which can be captured by a latching notch 100 defined by a latching arm 104 carried on a latch assembly 108 . The latch assembly includes the latching arm, a rod 112 extending through the latching arms 104 , the corresponding flanges 60 . The rod 112 defines an axis of rotation 114 to facilitate movement of the latching arms 104 relative to the flanges 60 .
In the unlocked position, a spring 118 biases the latch assembly 108 in a “locking” position. In this position, the latching arms 104 are positioned in a spring biased orientation towards the frame 24 . As the shaft 88 is rotated towards a head 120 of the latching arms 104 it draws against the arms and the spring force to engage in the latching notch 100 . The extent of movement of the shaft 88 in the arcuate passages 90 is designed to be at approximately the same position as the latching notch 100 . As such, the shaft 88 can dead stop in the arc 90 and be retainably latched by the latching arms 104 in a locked “open” position.
When the latching assembly 108 is to be disengaged the operator presses against the arms 122 on the latch to overcome the spring force and disengage the shaft 88 from the latching notch 100 . Rotary movement of the latching assembly 108 about the axis of rotation 114 results in disengaging the notch 100 from the corresponding ends 98 of the shaft 88 . Disengagement of the latching assembly 108 from the shaft 88 of the second spherical bearing assembly 82 allows the panel to be repositioned over the opening 22 to close the opening.
Turning now to more detail discussion of the individual parts used in the described operation, referenced made to the exploded perspective view of the hinge assembly 30 as shown in FIG. 5 in combination with the cross sectional illustrations as shown in FIGS. 6 and 7 .
With regard to FIG. 5 , the exploded perspective view shows the numerous components of the latch assembly identified in relation to the other corresponding components. For example, it can be seen that the gooseneck arm 42 has a bearing end 74 and a distal end 50 . The bearing end includes the first bearing assembly 70 and the second bearing assembly 82 . Both bearing assemblies include corresponding sleeves 130 positioned on either side of the corresponding circle bearings which include a race 132 and a corresponding ball 134 retained within the race 132 . The assembled sleeves and bearings are retained in the corresponding bores 138 , 140 . The first bearing assembly 70 also includes corresponding spacers 142 positioned on either side of the bearing assembly 78 to facilitate angular movement that restrict translational movement. The spacers 142 are not provided with regard to the second bearing assembly 82 so as to provide some degree of translational movement relative to the shaft 88 .
The distal end 50 includes the brackets 46 with corresponding fasteners 144 , shown in the form of a rivet, to retain the brackets 46 on the distal end 50 . A passage 146 has been formed in the distal end to provide additional weight reduction of the overall assembly. Similarly, a recessed area 148 is formed a central arcuate portion 150 of the gooseneck 42 . This area has also been engineered to reduce the mass of the assembly without compromise of the structural function and integrity of the assembly.
As also shown in FIG. 5 , the shaft 64 extends along the axis 68 through the corresponding passages 152 formed through the flanges 60 . The central portion of the shaft 64 extends through the corresponding spacers 142 , sleeves 130 , bearing assembly 78 and bore 138 . Corresponding washers 154 are provided on either end of the flange 60 with a threaded end 156 of the shaft 64 engaging the corresponding nut 158 to retain the assembly 70 in engagement at the bearing end 74 .
The second bearing assembly 82 is similarly assembled with the shaft 88 extending through the passages 90 , sleeve 130 , bearing assembly 78 and bore 140 . Corresponding washers 160 , bushings 162 , flat washers 164 and engaging screws 166 retain the second assembly 82 in position at the bearing end 74 .
With further reference to FIG. 5 , the latch assembly 108 is shown with the latching arms 104 extending from a corresponding cross bar 168 with the arms 122 extending therefrom. Pivot knuckles 170 include passages 172 extending there through for receipt of the rod 112 . The rod extends through the corresponding bushings 176 and passages 178 on the corresponding flanges 60 . As assembled the latch assembly 108 positions the pivot knuckles 170 on the outside portion of the flanges 60 with the biasing spring 118 contained inwardly of the corresponding flanges 60 . Retained ends 180 , 180 of the spring 118 are engaged in the corresponding flanges 60 , 60 and a leading end 182 of the spring 118 between the coils 184 is positioned against the cross bar 168 . The bushings 176 are positioned between the pivot knuckles 170 and the corresponding outside surface of the flanges 60 .
With regard FIGS. 6 and 7 , cross sectional views have been taken along corresponding lines 6 - 6 in FIGS. 3 and 7-7 in FIG. 3 . These cross sectional views show the assembled relationship of the bearing assembly 70 ( FIG. 7 ) and the corresponding assembled relationship of the latch assembly 108 .
In use, the hinge assembly 30 is attached to a corresponding frame 24 and panel 26 with the frame mounting end 34 and the panel mounting end 38 , respectively. A pair of bearing assemblies 70 , 82 is operatively retained on the frame mounting end 34 whereas the panel mounting end 38 is generally fixed to the panel. A gooseneck arm extends between these mounting locations to facilitate movement of the panel 26 relative to the frame 24 . In an open position a latch assembly 108 can retain the hinge assembly 30 in an open position. At the discretion of the user, the latch assembly 108 can be released to allow the hinge to facilitate closure of the panel 26 over the opening 22 in the frame element 24 .
The first bearing assembly 70 includes the spherical bearing 78 to facilitate a degree of angular motion relative to the mounting 34 . Similarly, the second bearing assembly 82 includes a second bearing 78 to facilitate additional angular motion. However, the operative association of the components facilitates translational motion of the second bearing assembly 82 carried on shaft 88 along and coaxial with the axis 94 . The combination of the bearing assemblies 70 , 82 facilitates additional movement and control of the hinge assembly 30 .
The foregoing terms as well as other terms should be broadly interpreted throughout this application to include all known as well as all hereafter discovered versions, equivalents, variations and other forms of the abovementioned terms as well as other terms. The present disclosure is intended to be broadly interpreted and not limited.
While the present disclosure describes various exemplary embodiments, the disclosure is not so limited. To the contrary, the disclosure is intended to cover various modifications, uses, adaptations, and equivalent arrangements based on the principles disclosed. Further, this application is intended to cover such departures from the present disclosure as come within at least the known or customary practice within the art to which it pertains. It is envisioned that those skilled in the art may devise various modifications and equivalent structures and functions without departing from the spirit and scope of the disclosure as recited in the following claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
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The present disclosure includes a hinge assembly for use in a hinged attachment of a panel relative to a frame and providing movement of the panel relative to the frame. A link which provides an extension or reach motion and positioning of the assembly, shown for purposes of illustration and not limitation in the form of a gooseneck arm, is provided in the hinge assembly to facilitate an extended range of motion of the hinge assembly. A first spherical bearing assembly and a second spherical bearing assembly are operatively associated with a bearing end of the link to provide multiple degrees of motion while securely retaining the panel relative to the frame. The hinge is intended to provide universal application of a single version of a hinge which can be used in multiple locations as facilitated by the multiple degrees of motion provided by the bearing end of the link.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/206,241, filed May 23, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to electric conduit box mountings and, more specifically to a mounting strap for retaining an electric conduit box within a retaining wall or cavity.
2. Description of Related Art
A variety of mounting devices have been devised for permanently and temporarily securing outlet boxes within the interior of a wall or cavity as a combination attachment. Many of the conventional electrical fixtures such as outlet boxes and the like require a number mechanical fasteners for mounting. Typically, when an outlet box is mounted to a wall, there is no remote need for having the box secured thereto, other than locally attaching a face plate for aesthetic appeal or residual wiring.
Although mechanical fasteners have proven effective for mounting electrical fixtures involving sheet rock or wall structures (i.e. non-conducting materials) having wood as interior support beams, etc., the installation of conduit boxes with cement or concrete casting become nearly impossible with conventional techniques. This effectiveness of the conventional techniques primarily rest with the workable qualities of wood, sheet rock or similar material. These materials unlike the physical properties of cement, concrete and the like are not brittle and are easy to cut and repair. While there is a tendency for mechanical fasteners to become unattached or unthreaded within these particular materials, as a result of wall repairs, replacements, etc. mechanical fasteners or threaded fasteners are typically easy to replace after material refillings, replacement of studs, or locating another place within the wall for securing the fastener accordingly.
This is not the case for concrete structures or the like which house electrical conduit boxes. Several difficulties arise which require new or unconventional methods to resolve. First of all, mechanical fasteners for concrete or similar material have a tendency to destroy the integrity of the building structure. These materials simply do not lend themselves to replacements as recited above. Secondly, electrical conduit boxes require not only secure attachment for local wiring or common electrical finishing, but require secure attachment for remote conveying of wires through conduits from level to level of various residential and industrial building interiors. In this regard, a need exists wherein electrical conduit boxes can be retained without the use of conventional techniques or mechanical fasteners as described herein. An electrical conduit box mounting strap which mounts conduit boxes without the use of mechanical fasteners as recited above are lacking.
For example, U.S. Pat. No. 1,246,107 issued to Kendig discloses a support for electrical fixtures comprising a frame provided with laterally extended flanges adapted to engage the front face of a wall and having supporting members on the side of the frame for engaging the wall behind the front face by insertion. These type of supports are considered conventional fixtures used for retaining power socket conduits or the like within an interior portion of a wall.
U.S. Pat. No. 3,115,265 issued to Mulkey et al. discloses an electrical outlet box having an expandable protector. The protector is a substantially rectangular three-piece insertable band for mounting the outlet box within a wall. The band includes two pairs of connected corner pieces which interconnect around the box as male and female interconnected pieces.
U.S. Pat. No. 2,605,806 issued to Tinnerman discloses a fastening device which accommodates the use of conventional mechanical fasteners such as nuts, bolts, screws, rivets and similar studs as a spring loaded fastening device. The device comprises a spring actuated hook-type attachment means which is designed for clip or snap fastening of a bolt or nut to prevent the accidental removal or displacement while turning or otherwise threading the respective element within an a complimentary threaded aperture.
U.S. Pat. No. 1,818,814 issued to G. R. Riggs et al. discloses an electrical outlet box support comprising a substantially C-shaped construction. Two sets of dual retaining apertures for mechanical fasteners are disposed on front top and bottom portions of the C-shaped support for attaching the support in combination with an outlet box to a wall.
U.S. Pat. No. 3,674,913 issued to Yates discloses a temporary support for an electrical outlet box comprising a transverse member which extends across an outer portion of a outlet box. The transverse bar member is spring loaded for attachment with an end of the outlet box for temporary mounting. Detachably connected to the transverse member is a support bracket having a general U-shape. The base of the U-shaped support is reduced in size for receiving loop-like ends from the tension springs for connections therewith in opposite directions.
U.S. Pat. No. 3,963,204 issued to Liss discloses an outlet box holder comprising a generally U-shaped strap member which is adapted to be inserted into an opening formed in a wall member. The strap member includes a base portion and a pair of legs which depend therefrom. Each leg has an outward directed extension end formed orthogonal thereto for attachment with a respective retainer. A retainer is adjustably and slidably mounted on each of the legs and has a first portion adapted to engage the inner surface of the wall member. Each of the retainers also has a second portion which is adapted to extend through the opening. The outlet box is inserted into the opening and is received between the retainers. The box holder is a distinctive three-piece outlet box retainer.
U.S. Pat. No. 4,693,438 issued to Angell discloses an electrical box retainer made of thin sheet metal. The retainer has a folded and flattened work hardened nose, a two layer leading protrusion, a divergent barb, an elongated shank and a multiple outward flange having a grasping catch for receiving an insertion tool. At least two retainers are needed to adequately secure an outlet-box within the interior of a wall.
U.S. Pat. No. 5,641,940 issued to Whitehead discloses a poke-through electrical connection assembly retainer which includes an elongate generally tubular housing member and at least one retaining clip for securing the connector in an interfloor passage. The retaining clip includes a transverse flexure portion and at least one anchor point dimensioned and angled from the flexure portion for substantially radially-directed engagement with the wall of the interfloor passage.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The electrical conduit box mounting strap according to the invention is a single unitary structure for mounting conduit boxes as a fixed rigid composite structure within the volume of an internal void or cavity of concrete, cement or similar block material. The mounting strap provides a rigid and stable electrical fixture for conveying electrical wire through conduit. The strap is shaped to form a number of different attachment ends for securing an outlet box within a number of different materials.
Accordingly, it is a principal object of the invention to provide an electrical conduit box mounting strap which retains conduit boxes within concrete, cement or similar wall structures as a stationary conduit box for conveying wiring or the like therethrough.
It is another object of the invention to provide an electrical conduit box mounting strap which attaches to and/or secures conduit boxes without the use of mechanical fasteners.
It is a further object of the invention to provide an electrical conduit box mounting strap which is flexible and structurally rigid as a conduit box retainer.
Still another object of the invention is to provide an electrical conduit box mounting strap as a single unitary retaining structure.
It is an object of the invention to provide improved elements and arrangements thereof in the electrical conduit box mounting strap for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental, perspective view of a conventional electrical conduit box mounted within a concrete block.
FIG. 2 is an environmental perspective view of the electrical conduit box and strap according to the present invention.
FIG. 3 is a perspective view similar to FIG. 2, the concrete block being broken away to reveal interior detail.
FIG. 4 is a perspective view similar to FIG. 3 of the electrical conduit box and strap according to a second embodiment.
FIG. 5 is a top view of the electrical conduit box and strap according to a third embodiment.
FIG. 6 is a top view of the electrical conduit box and strap according to a fourth embodiment.
FIG. 7 is front view of the electrical conduit box according to the fourth embodiment, illustrating side and rear insertable slots for inserting the strap as a conduit box retainer.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is an electrical conduit box mounting strap for mounting conduit boxes within various material structures. The preferred embodiments of the present invention are depicted in FIGS. 2-7, and are generally referenced by numerals 8 , 9 , 10 and 11 respectively.
As diagrammatically illustrated in FIG. 1, there is shown a conventional electrical conduit box assembly 7 comprising a conduit box 12 disposed within a cement, concrete or similar block material 14 having at least one interior cavity 16 . This particular arrangement is shown without a retainer which allows the electrical conduit box 12 to move within the cavity 16 when electrical cables or the like (not shown) are pulled through the conduit 13 to be conveyed to another physical layer of a building or similar structure for electrical power output. The pulling force F typically required for electrical cable conveyance or the like usually causes the unrestrained conduit box 12 to bang or dangle within the cavity 16 thereby causing unwanted damage to the conduit 13 or the box 12 .
As best seen in FIGS. 2 and 3, the electrical conduit box and mounting strap assembly 8 according to the preferred embodiment of the present invention comprises a strap 20 having a substantially rectangular configuration for mating and abutting attachment with at least one interior cavity 16 formed within a cement, concrete or similar block of material 14 . The attachment of the strap 20 within the cavity is retained by friction between at least one surface S of the strap 20 and at least one interior surface S i of a cavity 16 formed within a respective material 14 . This particular method of attachment also includes wherein the strap 20 is made contiguous with at least one surface S cb of the conduit box or similar box material 12 . As in the conventional conduit box assembly 7 , the conduit box 12 has at least one conduit 13 attached thereto for conveying electrical wires or the like therethrough.
According to the preferred embodiment, the strap 20 comprises a first 20 a , second 20 b , third 20 c , fourth 20 d and fifth 20 e surface S for respective attachment with a distinct first 16 a second 16 b , third 16 c , fourth 16 d , and fifth 16 e interior surface S i of the cavity 16 . Depending on the specific electrical needs, the number of conduit boxes 12 installed within a single block of material 14 can vary as a matter of design choice by one having ordinary skill in the art. Notwithstanding, the strap 20 is mounted within the cavity 16 having at least one surface S of the strap 20 attached or mounted contiguous with at least one surface S cb of a conduit box 12 . The conduit box 12 comprises first, second, and third mating surfaces for attachment with corresponding sixth 20 f , seventh 20 g , eighth 20 h and ninth 20 i surfaces S of the strap 20 .
The conduit 13 of the conduit box 12 is preferably centrally disposed on a top surface 12 e of the conduit box 12 and is substantially cylindrical. FIG. 3 illustrates the abutting and mating attachment of the strap 20 with both the interior walls of the cavity 16 and the respective surfaces of the conduit box 12 made contiguous therewith.
Other variations of the electrical conduit box mounting strap assembly 8 , are diagrammatically illustrated in FIGS. 4-6 according to embodiments 9 , 10 and 11 , respectively. As illustrated in FIG. 4 according to a second embodiment, the mounting strap 30 has similar abutting and mating surface attachments within the cavity 16 as previously recited above, except that the strap 30 is made to mount the conduit box 12 via contiguous attachment with a surface portion of the substantially cylindrical conduit 13 . The strap 30 includes respective first and second conduit abutting surfaces 30 a , 30 b which are shaped to the contour of the conduit 13 .
As diagrammatically illustrated in FIG. 5 according to a third embodiment, the strap 40 is configured with respective first and second orthogonal recessed planar ends 40 a and 40 b for mating and abutting attachment with a respective first and second protruding orthogonal planar surface corner 42 and 44 of the conduit box 12 . This particular arrangement provides alternative fixed security within an interior cavity 16 of the block of material 14 as similarly recited above.
For additional structural reinforcement according to the third embodiment, FIG. 6 schematically illustrates that the box 12 further comprises at least one insertable slot 50 permanently fixed thereto for insertable attachment of the respective first and second orthogonal recessed planar ends 40 a , 40 b of the strap 40 . Each slot 50 is more clearly shown and identified in FIG. 7 from a front view of the electrical conduit box 12 .
Other advantages of the strap according to the invention includes making the respective straps 20 , 30 and 40 out of a flexible yet structurally rigid metallic or composite material.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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An electrical conduit box mounting strap is described having a single unitary structure. The strap is used for mounting conduit boxes as a fixed rigid composite structure within a volume of an internal void or cavity of a concrete, cement or similar block of material. The strap is shaped and configured to stabilize the conduit box, particularly as conduit wires are pulled therethrough.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to the field of urethane catalysts. More particularly, this invention relates to the use of certain amines as urethane catalysts.
2. Description of the Prior Art
The use of a catalyst in preparing polyurethanes by the reaction of a polyisocyanate, a polyol and perhaps other ingredients is known. The catalyst is employed to promote at least two, and sometimes three major reactions that must proceed simultaneously and competitively at balanced rates during the process in order to provide polyurethanes with the desired physical characteristics. One reaction is a chain extending isocyanate-hydroxyl reaction by which a hydroxyl-containing molecule is reacted with an isocyanate-containing molecule to form a urethane. This increases the viscosity of the mixture and provides a polyurethane containing secondary nitrogen atom in the urethane groups. A second reaction is a cross-linking isocyanate urethane reaction by which an isocyanate-containing molecule reacts with a urethane group containing a secondary nitrogen atom. The third reaction which may be involved is an isocyanate-water reaction by which an isocyanate-terminated molecule is extended and by which carbon dioxide is generated to blow or assist in the blowing of the foam. This third reaction is not essential if an extraneous blowing agent, such as a halogenated, normally liquid hydrocarbon, carbon dioxide, etc., is employed, but is essential if all or even a part of the gas for foam generation is to be generated by this in situ reaction (e.g. in the preparation of "one-shot" flexible polyurethane foams.)
The reactions must proceed simultaneously at optimum balanced rates relative to each other in order to obtain a good foam structure. If carbon dioxide evolution is too rapid in comparison with chain extension, the foam will collapse. If the chain extension is too rapid in comparison with carbon dioxide evolution, foam rise will be restricted, resulting in a high density foam with a high percentage of poorly defined cells. The foam will not be stable in the absence of adequate crosslinking.
It has long been known that tertiary amines, such as trimethylamine, triethylamine, etc., are effective for catalyzing the second crosslinking reaction. Other typical tertiary amines are set forth in U.S. Pat. Nos. 3,925,268; 3,127,436; and 3,243,389 and German OLS 2,354,952 and 2,259,980. Some of the tertiary amines are effective for catalyzing the third water-isocyanate reaction for carbon dioxide evolution. However, tertiary amines are only partially effective as catalysts for the first chain extension reaction. To overcome this problem, the so-called "prepolymer" technique has been developed wherein a hydroxy-containing polyol component is partially reacted with the isocyanate component in order to obtain a liquid prepolymer containing free isocyanate groups. This prepolymer is then reacted with additional polyol in the presence of a tertiary amine to provide a foam. This method is still commonly employed in preparing rigid urethane foams, but has proven less satisfactory for the production of flexible urethane foams.
For flexible foams, a one-step or "one-shot" process has been developed wherein a tertiary amine, such as triethylenediamine, is employed in conjunction with an organic tin compound. Triethylenediamine is particularly active for promoting the water-isocyanate reaction and the tin compound is particularly active in synergistic combination with the triethylenediamine for promoting the chain extension reaction. However, even here, the results obtained leave much to be desired. Triethylenediamine is a solid and must be dissolved prior to use to avoid processing difficulties. Also, triethylenediamine and other of the prior art amines can impart a strong amine odor to the polyurethane foam.
In addition to problems of odor and handling due to solid character other tertiary amines suffer still further deficiencies. For example, in some instances the compounds are relatively high in volatility leading to obvious safety problems. In addition, some catalysts of this type do not provide sufficient delay in foaming, which delay is particularly desirable in molding applications to allow sufficient time to situate the preform mix in the mold. Yet other catalysts, while meeting specifications in this area, do not yield foams with a desirable tack-free time.
Lastly, while certain tertiary amines are somewhat suitable in this catalysis often even they nevertheless do not have a sufficiently high tertiary amine content in terms of the number of tertiary amines compared to overall molecular weight. It is believed that the higher the tertiary amine content the more rapid the catalytic activity in the polyurethane art.
It would therefore be a substantial advance in the art if a new class of amine catalysts were discovered which overcome some of the just enumerated disadvantages of the prior art.
SUMMARY OF THE INVENTION
A new class of compounds have been found useful as polyurethane catalyst. The compounds have the following structural formula: ##STR2## where R is lower alkyl and X is hydrogen or CONR 1 R 2 where R 1 and R 2 are independently selected from the group consisting of hydrogen, alkyl and aryl with the single proviso that both R 1 and R 2 may not be aryl.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The compounds here may be prepared by resorting to a wide variety of synthetic techniques. However, preferably these compositions are prepared by first making bis(dialkylaminopropyl)-amine which I have also found useful as a urethane catalyst. The bis-amine again may also be prepared by a variety of known techniques. However, one excellent mode or preparation involves reaction of dimethylamine with acrylonitrile followed by hydrogenation of the resultant condensate to produce dimethylaminopropylamine. In producing the dimethylaminopropylamine, one also produces bis-(dimethylaminopropyl)amine which may be removed from dimethylaminopropylamine by conventional means such as distillation and the like.
The bis-amine, which as noted above has itself been found useful as a urethane catalyst is then reacted with urea or alkyl or aryl isocyanates to form the urea or substituted urea adducts. When an alkyl isocyanate is utilized as a reactant, it is preferred that it be a lower alkyl isocyanate whereas the alkyl group contains 1-4 carbon atoms. Preferably, when an aryl isocyanate is utilized, it is a phenyl isocyanate or a substituted phenyl isocyanate where the substituent is a halo, nitro, cyano or alkyl substituent.
It is believed that where R 1 and R 2 are hydrogen the compound prepared is itself novel. Thus, X in such instance is CONH 2 .
The compounds here possess a number of useful characteristics making them exceptionally attractive as polyurethane catalysts. For example, the just defined compounds have a high tertiary amine content and resultant rapid catalytic activity in the polyurethane foam area. Tertiary amine content is calculated as the number of tertiary amines divided by the molecular weight times 1,000. For example, N,N-bis(dimethylaminopropyl)urea has a tertiary amine content of 8.7 meq/g. Further catalysis of the urethane reactions is gained from the urea function in the catalyst compound. In addition, the compounds here are also relatively non-volatile and possess little if any odor. With respect to the products, there are no solids handling problems such as are present with well known polyurethane catalysts as triethylenediamine. The catalysts of the invention are particularly desirable in foaming urethane formations in that they provide a sufficient delay in the foaming operation to aid in processing. Yet the catalysts also give good foams with desirable tackfree times. As noted above, this delay time is particularly desirable in molding applications to allow sufficient time to situate the prefoam mix in the mold. Further, the compounds are easily prepared as typically described above, and are relatively inexpensive. Lastly, since the compounds possess an active hydrogen in the molecule the catalyst will be chemically bound to the finished urethane and will have no tendency therefore to diffuse out causing odor and/or oily film problems.
The successful use of compounds such as bis-(dimethylaminopropyl)-amine as urethane catalysts is somewhat unexpected, since such compounds may be considered easily deactivated as catalysts due to their immobility after their combination with isocyanate groups in the reacting polymer and polyisocyanate. The basic NH linkage is very reactive with isocyanates. Thus, it is surprising that such amines give a cured foam when it is used as the exclusive catalyst. It is believed that even if this novel catalyst does react with an isocyanate, a high amine equivalent catalyst remains in the reacting polymer mixture, namely a urea function which is apparently still an effective catalyst.
To prepare polyurethanes using the catalysts here any aromatic polyisocyanate may be used. Typical aromatic polyisocyanates include m-phenylene diisocyanate, p-phenylene diisocyanate, polymethylene polyphenylisocyanate, 2,4-toluene diisocyanate, 2,6-tolylene diisocyanate, dianisidine diisocyanate, bitolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylene-4,4'-diisocyanate, aliphatic-aromatic diisocyanates, such as xylylene-1,4-diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, bis(4-isocyanatophenyl) methane, bis(3-methyl-4-isocyanatophenyl) methane, and 4,4'-diphenylpropane diisocyanate.
Greatly preferred aromatic polyisocyanates used in the practice of the invention are 2,4- and 2,6- toluene diisocyanates and methylene-bridged polyphenyl polyisocyanate mixtures which have a functionality of from about 2 to about 4. These latter isocyanate compounds are generally produced by the phosgenation of corresponding methylene bridged polyphenyl polyamines, which are conventionally produced by the reaction of formaldehyde and primary aromatic amines, such as aniline, in the presence of hydrochloric acid and/or other acidic catalysts. Known processes for preparing the methylene-bridged polyphenyl polyamines and corresponding methylene-bridged polyphenyl polyisocyanates therefrom are described in the literature and in many patents, for example, U.S. Pat. Nos. 2,683,730; 2,950,263; 3,012,008; 3,344,162; and 3,362,979.
Most preferred methylene-bridged polyphenyl polyisocyanate mixtures used here contain from about 20 to about 100 weight percent methylene diphenyldiisocyanate isomers with the remainder being polymethylene polyphenyl diisocyanates having higher functionalities and higher molecular weights. Typical of these are polyphenyl polyisocyanate mixtures containing about 20 to 100 weight percent methylene diphenyldiisocyanate isomers, of which 20 to about 95 weight percent thereof is the 4,4'-isomer with the remainder being polymethylene polyphenyl polyisocyanates of higher molecular weight and functionality that have an average functionality of from about 2.1 to about 3.5. The isocyanate mixtures are known commercially available materials and can be prepared by the process described in U.S. Pat. No. 3,362,979, issued Jan. 9, 1968 to Floyd E. Bentley.
The hydroxyl-containing polyol component which reacts with the isocyanate may suitably be a polyester polyol or a polyether polyol having a hydroxyl number ranging from about 700 to about 25, or lower. When it is desired to provide a flexible foam, the hydroxyl number is preferably in the range from about 25 to 60. For rigid foams, the hydroxyl number is preferably in the range from 350 to 700. Semi-rigid foams of a desired flexibility are provided when the hydroxyl number is intermediate to the ranges just given.
When the polyol is a polyester, it is preferable to use, as the polyester, a resin having a relatively high hydroxyl value and a relatively low acid value made from the reaction of a polycarboxylic acid with a polyhydric alcohol. The acid component of the polyester is preferably of the dibasic or polybasic type and is usually free of reactive unsaturation, such as ethylenic groups or acetylenic groups. The unsaturation, such as occurs in the rings of such aromatic acids as phthalic acid, terephthalic acid, isophthalic acid, or the like, is nonethylenic and non-reactive. Thus, aromatic acids may be employed for the acid component. Aliphatic acids, such as succinic acid, adipic acid, sebacic acid, azelaic acid, etc., may also be employed. The alcohol component for the polyester should preferably contain a plurality of hydroxyl groups and is preferably an aliphatic alcohol, such as ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, glycerol, pentaerthyritol, trimethyloethane, trimethylolpropane, mannitol, sorbitol, or methyl glucoside. Mixtures of two or more of the above identified alcohols may be employed also if desired. When a flexible urethane foam is desired, the polyol should preferably have an average functionality of from about 2 to about 4 and a molecular weight of from about 2,000 to about 4,000. For rigid foams, the functionality of the polyol component is preferably from about 4 to about 7.
When the hydroxyl-containing component is a polyether polyol for use in flexible polyurethane foam, the polyol may be an alkylene oxide adduct of a polyhydric alcohol with a functionality of from about 2 to about 4. The alkylene oxide may suitably be ethylene oxide, propylene oxide, or 1,2-butylene oxide, or a mixture of some or all of these. The polyol will suitably have a molecular weight within the range of from about 2,000 to about 7,000. For flexible polyether polyurethane foams, the alkylene oxide is preferably propylene oxide or a mixture of propylene oxide and ethylene oxide and the hydroxyl number is preferably within the range of about 25 to 60.
For rigid polyether polyurethane foams, the polyol should have a functionality of from about 4 to about 7 and a molecular weight of from about 300 to about 1200. Polyols for rigid polyether polyurethane foams may be made in various ways including the addition of an alkylene oxide as above to a polyhydric alcohol with a functionality of from 4 to 7. These polyols may also be, for example, Mannich condensation products of a phenol, an alkanolamine, and formaldehyde, which Mannich condensation product is then reacted with an alkylene oxide. See U.S. Pat. No. 3,297,597.
The amount of hydroxyl-containing polyol compound to be used relative to the isocyanate compound in both polyester and polyether foams normally should be such that the isocyanato groups are present in at least an equivalent amount, and preferably, in slight excess, compared with the free hydroxyl groups. Preferably, the ingredients will be proportioned so as to provide from about 1.05 to about 1.5 mol equivalents of isocyanato groups per mol equivalent of hydroxyl groups. However, for certain shock absorbing foams we have found that by using the catalysts of our invention the mol equivalents of isocyanate to hydroxyl groups can be as low as 0.4.
When water is used, the amount of water, based on the hydroxyl compound, is suitably within the range of about 0.05 to about 5.0 mol per mol equivalent of hydroxy compound.
It is within the scope of the present invention to utilize an extraneously added inert blowing agent such as a gas or gas-producing material. For example, halogenated low-boiling hydrocarbons, such as trichloromonofluoromethane and methylene chloride, carbon dioxide, nitrogen, etc., may be used. The inert blowing agent reduces the amount of excess isocyanate and water that is required in preparing flexible urethane foam. For a rigid foam, it is preferable to avoid the use of water and to use exclusively the extraneous blowing agent. Selection of the proper blowing agent is well within the knowledge of those skilled in the art. See for example U.S. Pat. No. 3,072, 082.
The catalysts discovered here as useful in the preparation of rigid or flexible polyester or polyether polyurethane foams based on the combined weight of the hydroxyl-containing compound and polyisocyanate, are employed in an amount of from about 0.05 to about 4.0 weight percent. More often that the amount of catalyst used is 0.1-1.0 weight percent.
The catalysts of this invention may be used either alone or in a mixture with one or more other catalysts such as other tertiary amines or with an organic tin compound or other polyurethane catalysts. The organic tin compound, particularly useful in making flexible foams may suitably be a stannous or stannic compound, such as a stannous salt of a carboxylic acid, a trialkyltin oxide, a dialkyltin dihalide, a dialkyltin oxide, etc., wherein the organic groups of the organic portion of the tin compound are hydrocarbon groups containing from 1 to 8 carbon atoms. For example, dibutyltin dilaurate, dibutyltin diacetate, diethyltin diacetate, dihexyltin diacetate, di-2-ethylhexyltin oxide, dioctyltin dioxide, stannous octoate, stannous oleate, etc., or a mixture thereof, may be used.
Such other tertiary amines include trialkylamines (e.g. trimethylamine, triethylamine), heterocyclic amines, such as N-alkylmorpholines (e.g., N-methylmorpholine, N-ethylmorpholine, etc.), 1,4-dimethylpiperazine, triethylenediamine, etc., aliphatic polyamines, such as N,N,N'N'-tetramethyl-1,3-butanediamine.
Conventional formulation ingredients are also employed, such as, for example, foam stabilizers also known as silicone oils or emulsifiers. The foam stabilizer may be an organic silane or siloxane. For example, compounds may be used having the formula:
RSi[O--(R SiO).sub.n --(oxyalkylene).sub.m R].sub.3
wherein R is an alkyl group containing from 1 to 4 carbon atoms; n is an integer of from 4 to 8; m is an integer of 20 to 40; and the oxyalkylene groups are derived from propylene oxide and ethylene oxide. See, for example, U.S. Pat. No. 3,194,773.
In preparing a flexible foam, the ingredients may be simultaneously, intimately mixed with each other by the so-called "one-shot" method to provide a foam by a one-step process. In this instance, water should comprise at least a part (e.g., 10% to 100%) of the blowing agent. The foregoing methods are known to those skilled in the art, as evidenced by the following publication: duPont Foam Bulletin, "Evaluation of Some Polyols in One-Shot Resilient Foams," Mar. 22, 1960.
When it is desired to prepare rigid foams, the "one-shot" method or the so-called "quasi-prepolymer method" is employed, wherein the hydroxyl-containing component preferably contains from about 4 to 7 reactive hydroxyl groups, on the average, per molecule.
In accordance with the "quasi-prepolymer method," a portion of the hydroxyl-containing component is reacted in the absence of a catalyst with the polyisocyanate component in proportions so as to provide from about 20 percent to about 40 percent of free isocyanato groups in the reaction product, based on the polyol. To prepare a foam, the remaining portion of the polyol is added and the two components are allowed to react in the presence to catalytic systems such as those discussed above and other appropriate additives, such as blowing agents, foam stabilizing agents, fire retardants, etc. The blowing agent (e.g., a halogenated lower aliphatic hydrocarbon), the foam-stabilizing agent, the fire retardant, etc., may be added to either the prepolymer or remaining polyol, or both, prior to the mixing of the component, whereby at the end of the reaction a rigid polyurethane foam is provided.
Urethane elastomers and coatings may be prepared also by known techniques in accordance with the present invention wherein a tertiary amine of this invention is used as a catalyst. See, for example, duPont Bulletin PB-2, by Remington and Lorenz, entitled "The Chemistry of Urethane Coatings."
The invention will be illustrated further with respect to the following specific examples, which are given by way of illustration and not as limitations on the scope of this invention.
EXAMPLE 1
To a 500 ml reactor was charged 200 g of dimethylaminopropylamine reactor bottoms (containing about 75% by weight bis-(dimethylaminopropyl)amine, (BDMAPA) and 69.5 g urea. Nitrogen was passed over the mixture as it was stirred and heated for 9 hr. at 150° C. Ammonia evolved during the heating period. The product was a viscous liquid containing 8.1 meq/g amine by titration. NMR and IR spectroscopy confirmed that the major material present was N,N-bis(dimethylaminopropyl)urea.
EXAMPLE 2
To a dry 500 ml reactor containing 73 g of distilled BDMAPA was added dropwise 42.4 ml of phenyl isocyanate by means of a constant addition funnel. The exothermic, stirred reaction was cooled by immersing the reactor in a water bath, never allowing the reaction temperature to exceed 50° C. A nitrogen atmosphere was maintained throughout the reaction. After the addition of phenyl isocyanate, the viscous reaction mixture was heated to 80° C and a vacuum applied to 0.4 mm of mercury and maintained for 30 min. After cooling, 119 g, 99.6% of N,N-bis(dimethylaminopropyl)-N'-phenylurea was isolated; this structure was confirmed by NMR and IR spectroscopy. The amine equivalent of the product was 6.69 meq/g. Viscosity was 207 cp. at 25° C.
EXAMPLE 3
To a 250 ml reactor containing 93.5 g of distilled BDMAPA equipped with a stirrer, thermometer, a nitrogen atmosphere, and an addition funnel was added dropwise over 0.5 hr 28.5 g of methyl isocyanate. Viscosity increased during the addition. The mixture was then stirred and heated by a hot water bath while applying a 0.5 mm vacuum for 0.5 hr. N,N-bis(dimethylaminopropyl)-N'-methylurea was isolated in 98.4% yield. NMR and IR spectroscopy confirmed the structure. Amine content was 8.0 meq/g. Viscosity was 148 cp at 25° C.
EXAMPLE 4
This example illustrates utility of compounds disclosed here as urethane catalysts in a flexible urethane formulation. The experiment consisted of mixing 48.4 parts toluene diisocyanate on a high speed mixer with the following blend of components:
______________________________________THANOL® F-3520 polyol.sup.1 100 partsWater 4 partsSilicone surfactant 1 partStannous octoate 0.6 partsTest catalyst 0.1 parts______________________________________ .sup.1 A glycerine based polyether polyol of 3500 molecular weight containing 15% ethylene oxide available from Jefferson Chemical Co., Houston, Texas.
The blended components were poured into a mold and allowed to rise. Results:
______________________________________TEST CATALYST RISE TIME FOAM APPEARANCE______________________________________Catalyst of Example 1 100 sec GoodCatalyst of Example 2 97 sec Good______________________________________
EXAMPLE 5
This example illustrates further utility of the urethane catalysts of this invention. The components below were blended with a high speed stirrer, then poured into a standard mold and allowed to rise to provide a rigid foam.
______________________________________ PARTS BLENDED______________________________________MONDUR® MR Polyisocyanate 46.62500 parts THANOL® RS-700 Polyol.sup.2 52.434 parts Silicone surfactant880 parts Fluorocarbon blowing agentCatalyst Tested 1.0______________________________________
The results are recorded below:
______________________________________ CREAM TACK FREE RISECATALYST TESTED TIME TIME TIME______________________________________Catalyst from Example 3 56 sec 190 sec 305 secBDMAPA 40 sec 147 sec 160 sec______________________________________ .sup.1 Polyphenylmethylene polyisocyanate of average functionality 2.7, a product of Mobay Chemical Corp. .sup.2 A nine mole propoxylate of sorbitol
EXAMPLE 6
This example illustrates further use of catalysts in a flexible urethane formulation. The experiment was performed by mixing 49.7 parts of toluene diisocyanate with the formulation below on a high speed stirrer, then allowing the formulation to rise in a standard mold.
______________________________________THANOL® F-3000 Polyol 100 partsWater 4.0 partsSilicone surfactant 1.0 partsTin catalyst 0.7 partsCatalyst tested 0.1 parts______________________________________ .sup.1 A 50 mole propoxylate of glycerine.
Results:
______________________________________ CREAM TIME RISE TIMECATALYST TESTD (SEC) (SEC)______________________________________Catalyst from Example 1 10 87______________________________________
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Covers a method of producing a polyurethane by utilizing compounds of the structure below as catalysts in reacting an organic polyisocyanate with an organic polyester polyol or polyether polyol in the presence of said catalyst: ##STR1## where R is lower alkyl and X is hydrogen or CONR 1 R 2 where R 1 and R 2 are independently selected from the group consisting of hydrogen, alkyl and aryl with the proviso that both R 1 and R 2 may not be aryl.
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FIELD OF THE INVENTION
The invention relates to a process for the removal of wood extractives from wood particulates without significantly affecting the integrity of cellulosic components of the wood or removing lignin. More particularly, the process of the invention uses solvent extraction techniques to remove volatile organic compounds, as well as higher molecular weight pitch compounds, from wood particulates thereby facilitating the further processing of the wood into composite boards, paper, and pulp products while significantly reducing the release of potentially harmful byproducts into the environment.
BACKGROUND OF THE INVENTION
As a preliminary matter, wood can be viewed as consisting of two major components, carbohydrates and lignin. Other components constitute a minor part of the wood and manifest as intercellular material, and extraneous substances that are related to the growth of the cells of the tree. The cell walls of the wood are composed of polysaccharides, the chief of which is cellulose. Lignin, on the other hand, is an amorphous substance, partly aromatic in nature, that has been called a "cementing material" or an "encrusting substance." It is insoluble in water and in most common organic solvents. It is also insoluble in acids, but undergoes condensation reactions in the presence of strong mineral acids. Lignin is partly soluble in alkaline solutions and is readily attacked and solubilized by oxidizing agents.
The extraneous substances of wood are deposited as cells grow, or after they reach maturity. Most of these substances are relatively simple compounds, having a low molecular weight. These low molecular weight substances include pectins, proteins, and like substances that are soluble in water or neutral organic solvents. The extraneous substances also include "wood extractives" that include pitch and volatile organic compounds.
To produce boards (oriented strand board, particleboard, veneerboard) composite wood products, and paper and pulp products, raw logs or wood fibrous material must be reduced to wood chips, flakes or sawdust. These wood particulates are then further processed, either by bonding together with a suitable glue to make board products, or undergoing pulping and forming processes to produce a variety of papers, paper boards and absorbent products. However, the processing of logs into wood particulates, and thence into finished products, poses several challenges. Some of these arise from the nature of wood, namely, that it includes not only cellulosic fibers and lignin but also "wood extractives," as discussed above. These naturally-occurring wood extractives are found in both resin canals within the structure of the wood, as well as within the parenchyma cells of the wood. In general, the extractives may be divided into a higher molecular weight, higher boiling point fraction, commonly known as "pitch", and a lower molecular weight, lower boiling point fraction that falls within the definition of "volatile organic compounds." The United States Environmental Protection Agency (EPA) has determined that volatile organic compounds (VOCs) pose an environmental hazard when they are released into the atmosphere. These VOCs are defined in 40 CFR Part 51(s) as "any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions." Typically, these are volatile, low molecular weight organic compounds. The EPA has promulgated regulations limiting the quantity of VOCs that a manufacturing facility may release into the atmosphere.
The release of VOCs into the atmosphere is a long-standing problem in the pulp and paper industry. Since VOCs occur naturally in timber, the processing of timber into wood particulates facilitates the migration or diffusion of VOCs to chip surfaces from which the compounds vaporize into the surrounding atmosphere. As a practical matter, since the industry requires a large inventory of wood chips for processing into board products and as feedstock in the pulp and paper processes, significant amounts of VOCs are released into the atmosphere from wood chip storage piles. Further, as illustrated in FIG. 1, VOCs are also released into the atmosphere during the processing of the wood chips into wood pulp products. As shown, logs 5' are processed into chips in chip mill 10' releasing VOCs 2' to the atmosphere. In pulping process operations, the chips are stored in mounds 7' as inventory for the process. These mounds continue to release VOCs 4' to the atmosphere. Some species of wood produce more VOCs than others. For example, loblolly pine is higher in VOC content than hemlock, and Douglas fir is intermediate between these two. The VOC-containing chips are then processed in a pulp mill 12', either a mechanical, thermomechanical, semi-chemical, or a chemical pulp mill, to produce cellulosic and fibrous pulps. During this pulping process, cellulosic fibers of the wood are separated from each other thereby allowing entrapped VOCs to diffuse to fiber surfaces and vaporize into the surrounding atmosphere. The cellulosic pulp produced may be bleached, and is then formed into a continuous web and dried on a pulp drier or paper machine 14'. During these processes, a further significant amount of VOCs may be released into the atmosphere. The combined chipping, crushing, pulping, and paper or absorbent product making processes release about one-third of the total natural extractives in the wood into the atmosphere (shown by arrows 2', 4', 6', and 8') as VOCs, and another one-third into effluent water (arrows 20', 22' and 24'). The papermill product 15', such as newsprint, writing paper, or absorbent products, includes the residual of about one-third of the total amount of extractives, mainly pitch with low amounts of VOCs.
As illustrated, wood particulates are also used as a raw material in composite wood boardmaking processes. The logs are usually debarked and reduced to flakes, fibers or other particulates on site then stored in bins as inventory for the boardmaking. Before being consolidated into boards, under heat and pressure, the wood particulates are dried to a desired moisture content in ovens. VOCs are emitted into the environment from the drying ovens and also from presses used to consolidate the dried particulates, with a binder, into boards. Thus, a board manufacturing process 26' also emits VOCs 28' while making boards 30'.
While the percentage of VOCs released into the atmosphere may appear small, relative to wood particulate mass, the actual quantity is nevertheless very significant. For example, a facility may process about 1,000-6,000 tons of wood chips per day. A 6,000 ton per day facility could produce 120 tons per day of VOCs. The EPA proposes limiting the amount of VOCs that any wood chip processing facility releases into the atmosphere by regulations requiting permits. Since a wood chip processing facility represents a significant capital investment, operators must take steps to limit VOC emissions while at the same time ensuring that processing equipment operate at or near full capacity for an adequate return on investment. To date, methods for limiting the quantity of VOC emissions have focused on enclosing the atmosphere surrounding any wood chip process that may release VOCs and subjecting air within the enclosure to treatment for the removal of VOCs, before release of the air into the environment. These methods require expensive equipment including large hoods to enclose equipment, fans and ducts for transporting air containing VOCs, and incinerators for combusting VOCs in the air. The methods also have high combustion fuel costs.
The higher boiling portion of the wood extractives, the pitch, presents separate and different problems in the processes for treating wood chips to produce boards or mechanical and thermomechanical paper and pulp products. In the pulp mill, the pitch separates from the cellulosic fibers and gradually builds up a scale within the process equipment and ducting of the mill. Ultimately, the pulp mill must be shut down so that this pitch scale may be manually removed. To reduce the frequency of shut-downs to remove pitch scale, sodium aluminate and alum is added to the pulping process in an attempt to fix the pitch to the surface of the cellulosic fiber. While this alleviates the equipment fouling problem, it does not eliminate the problem. Indeed, the addition of aluminum chemicals also poses a waste disposal problem since these chemicals are present in the process water. Although this water is recycled, a portion must be treated and disposed of. Pitch control requires additional operating costs for treatment chemicals, labor and facilities, and disposal.
Pitch also causes significant equipment fouling problems in pulp dryers and papermaking machines. In these capital intensive high speed machines, the pulp is formed into continuous sheets on high speed belts, dewatered, and dried. During these processes, colloidal pitch and pitch adhering to the fibers is transferred to the rolls and machine "clothing" of the pulp or papermaking machines to form a tacky, gummy surface deposit. This ultimately results in reduced product quality and machine efficiency. Removing the gum can require shutting down the papermaking machine, chemical cleaning or removing the clothing, and cleaning all affected surfaces. This results not only in cleaning costs and paper wastage losses, but also in significant machine downtime with consequent economic loss. Other methods of treatment include the use of continuous cleaning chemicals and equipment. Some of these chemicals may contribute to the release of VOCs and compositions with high biological oxygen demand (BOD) and/or high chemical oxygen demand (COD) into the environment.
There exists a need to reduce or eliminate the release into the environment of volatile organic compounds from processing operations that convert logs into wood particulates and that convert the particulates into other useful products. Further, there also exists a need to reduce or eliminate the downtime of wood pulping facilities and papermaking machines caused by fouling of equipment by pitch that occurs naturally in wood.
SUMMARY OF THE INVENTION
The invention provides a process for removing volatile organic compounds and pitch from wood particulates. As a result, the invention substantially reduces the emission of volatile organic compounds from board making processes, chip pulping, and pulp and paper forming and drying processes. The process of the invention also substantially reduces the mount of pitch in wood particulates, thereby reducing or substantially eliminating pitch fouling of equipment in pulp processing and papermaking processes. Further, the process of the invention allows the production of a paper pulp of superior strength, brightness, and optical properties.
According to the invention, wood particulates are contacted with a solvent for the removal of wood extractives including VOCs and pitch. The solvent extracts a proportion of naturally-occurring VOCs and pitch from the particulates, and is separated as a "miscella" from the leached wood particulates. The miscella, including solvent, water, VOCs, and pitch, is subjected to a separation process that reclaims the solvent for reuse, and produces a VOC product and a pitch product, which may be sold as a chemical feedstock or used as a fuel. The leached wood particulates, containing solvent, are subjected to a compression stage to express residual solvent. Optionally, or in combination, heat may be applied to vaporize and remove residual solvent. The vaporized solvent is condensed and recycled with expressed solvent for reuse in the extraction process. The leached wood particulates, now having substantially reduced VOCs and pitch concentrations, may then be subjected to processes for the production of composite board products or pulp products or absorbent products or paper products, with significantly reduced emissions of VOCs.
The process of the invention removes from about 50 to about 100 wt % of the VOCs present in the raw wood particulates. Further, the process also removes from about 40 to about 80 wt % of the pitch. In certain embodiments of the invention it may be preferred to use a mixture of solvents, one solvent that is highly effective for the removal of VOCs, and another solvent that is highly effective for the removal of higher molecular weight pitch products. Alternatively, the wood particulates may be subjected to a two-stage treatment process: One stage using a solvent to remove saponifiable extractives (also known as "hydrophilic" extractives), and another stage using a second solvent to remove unsaponifiable extractives (also known as "hydrophobic" extractives).
The invention solves a long-standing environmental problem by reducing the amount of VOCs released into the atmosphere in processes for converting wood into useful products such as particle board, oriented strand board, paper, absorbent products, and the like. Also, by removing pitch from the wood particulates, the invention permits the realization of significant cost savings in pulp mills and papermaking machine operations. The process of the invention also allows a substantial reduction in pitch scale formation in pulp mills, and on pulp and paper machines. This results in significant improvements in mill efficiencies and reduced use of pitch treatment chemicals, in pulp processes and process water, that pose a disposal problem. Further, the removal of pitch from wood particulates provides brighter wood particulates that resist age-darkening. This allows the production of wood-containing pulp (also known as "mechanical pulp") of higher brightness, thereby reducing the demand for chemical bleaches. Additionally, the BOD and COD of process water are reduced, alleviating the need for post environmental treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying simplified process flow-type drawings, not to scale, showing important process aspects of the invention and the prior art wherein:
FIG. 1 is a schematic block flow diagram of wood chip processing showing VOCs emissions in a prior art papermaking process and a prior art chipboard process; and
FIG. 2 is a schematic flow diagram of an embodiment of the process of the invention for VOC and pitch removal from wood chips;
FIG. 2A is a schematic flow diagram of an embodiment of a VOC-solvent-water separation process of the invention;
FIG. 2B is a schematic flow diagram of another embodiment of VOC-solvent-water separation process of the invention;
FIG. 3A is a schematic diagram of an embodiment of a chip extractor of the invention;
FIG. 3B is a schematic diagram of another embodiment of a chip extractor of the invention;
FIG. 3C is a schematic diagram of another embodiment of a chip extractor of the invention; and
FIG. 3D is a schematic diagram of another embodiment of a chip extractor of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The continuous process of the invention uses an extractive solvent, that is either a single liquid chemical compound or a mixture of such compounds, for dissolving and removing naturally occurring wood extractives from wood particulates suitable for use as chargestock in pulp and paper operations or board manufacture. The term "wood particulates" refers to wood chips, sawdust, flakes, shavings, and other such solid wood in particulate form. It should be understood, that although the following description may refer to "wood chips" the process of the invention is equally applicable to other wood particulates.
The term "wood extractives," as used in the specification and claims, refers to VOCs and pitch, and is measured as the extractives removed from wood using an ether soxhlet extraction in accordance with TAPPI Standard Test No. T204 om88 (modified to use diethyl ether as the extraction solvent). This test does not distinguish between VOCs and pitch but measures both as ether extractables of the wood. The percent wood extractives removed by the extraction process of the invention is arrived at by measuring the difference between the ether wood extractables in samples of the wood particulates before and after undergoing the extraction process of the invention.
While the specification and claims refer to VOCs and pitch as separate components of wood extractives, it is recognized that in prior art processes, not using the technology of the invention, emissions into the environment include both VOCs and pitch. Under process conditions, a proportion of non-VOC components also volatilizes and accompanies the VOCs as an emission from the process. Frequently, these volatilized wood extractives subsequently condense on process equipment, resulting in fouling. According to the present invention, VOCs and volatilized wood extractives are removed by extraction from the wood particulates.
The percentage of VOCs extracted from wood particulates is estimated by subjecting the extracted wood particulates to an oven heating procedure at 105° C. for 24 hours. The weight loss of wood particulates during this procedure corresponds to the residual VOCs remaining in the extracted particulates. Similarly, the quantity of VOCs in the raw particulates, before extraction, may be estimated by heating the particulates to 105° C. for 24 hours. Thus, the proportion of VOCs extracted may be readily estimated from the measured amounts of VOCs present in the particulates before and after extraction. The amount of pitch present before and after extraction may be found by the difference, since the total amount of wood extractives is determined by the TAPPI method, as explained above.
The term "significantly reduced pitch content" with reference to extracted wood particulates, means that at least about 40% of the naturally-occurring pitch has been extracted from the particulates. Preferably, from about 40% to about 80%, and more preferably from about 45% to about 75%, of the pitch is extracted.
The term "substantially reduced VOC content" referring to extracted wood particulates, means that at least about 40% of naturally occurring VOCs have been removed by extraction, preferably from about 50% to about 100%, most preferably from about 75% to about 95%.
Preferably, the solvent used in the extraction process of the invention is of a type that can be recycled for reuse in the process. To minimize solvent recovery costs when distillation is used in the recovery process, and to maintain the efficiency of the extraction process, it is preferred that the extractive solvent is miscible with water under process conditions and either does not form an azeotrope with water, or forms only a minimal azeotrope. In preferred embodiments, the solvent is applied to raw wood particulates that have not undergone a drying treatment to remove water, and consequently commingles with water. This process is preferred since it avoids costly drying processes. For ease of extraction, the extractive solvent should have a high affinity for wood, i.e., the solvent should readily diffuse or enter into spaces between cellulosic fibers to leach out wood extractives. To facilitate recovery and reuse of the solvent, the solvent should preferably have a physical property that allows ready separation from water, for example, a preferred solvent boils in the temperature range from about 40° to about 75° C. under atmospheric pressure conditions, to facilitate separation by distillation using steam as a heating medium. Alternatively, the solvent could boil at a temperature higher than water, although this is undesirable from an energy usage standpoint. Moreover, the solvent could be immiscible with water, as long as it is able to leach out VOCs or pitch, or both from wood particulates.
As indicated above, the extractive solvent may include a mixture of solvents. In particular, the mixture may include a first solvent that has a particularly high affinity for saponifiable components ("hydrophilic") of the extractives, and a second solvent that has a high affinity for the unsaponifiable ("hydrophobic") components. As a further alterative, according to the invention, the wood particulates may be sequentially subjected to one extractive process using a solvent for the removal of saponifiable components, and another extractive process using a different solvent for the removal of unsaponifiable components. The order of these two extraction processes is not important.
Preferably, the extraction process is carried out under as mild conditions of temperature and pressure as would require an extraction time of from about two hours to about 10 minutes, or less, to minimize equipment size for a particular rate of chips treated, in tons per hour. Most preferably, the time of extraction is about 30 minutes to about one hour for economical extraction equipment sizing. Extraction time, and hence size of equipment, is also solvent dependent. Certain solvents remove extractives at a faster rate and their leaching or solvent capability is not as strongly adversely affected by increasing concentrations of extractives in the solvent. Such solvents potentially minimize solvent recovery costs because of their faster extraction rates requiting smaller volumes of solvent.
Preferably, the mass ratio of solvent to wood particulates is in the range of from about 6:1 to about 1:1, more preferably about 4:1 to about 1:1, most preferably about 2:1. However, solvent:wood ratio also depends on extraction time and temperature and pressure conditions. Thus, longer extraction times allow a lower solvent:wood ratio for the same degree of extraction for a particular solvent. Also, higher temperatures and pressures allow reduced extraction time and reduced solvent:wood ratios. The mass ratio of solvent to wood is measured as the total mass of solvent that a particular mass of wood will encounter in a typical extractor. Thus, even if the extractor is charged with "dirty" solvent that is recycled, without first removing all wood extractives and water, the solvent:mass ratio refers to the sum of the mass of pure make-up solvent and the mass of solvent in the dirty recycled solvent stream, relative to the mass of dry wood in the extractor.
Temperature and pressure conditions also impose constraints on the selection of the solvent or solvents. Those solvents that are able to effectively remove wood extractives from wood particulates, under mild conditions of temperature and pressure, i.e., conditions that do not cause significant dissolution of lignin or significant attack of wood cellulosic components, are useful. Thus, it is preferred, within the equipment economic size constraint mentioned above, that the extraction process operate at a temperature in the range of from about 10° to about 150° C., more preferably from about 20° to about 130° C. Preferred pressure conditions range from about atmospheric pressure (14.7 psi) to about 50 psi, most preferably from about 15 to about 25 psi. Again, the combination of temperature, pressure and time of extraction should be selected to remove wood extractives without significantly affecting yield, as discussed above.
According to the invention, the preferred solvent for the extraction of VOCs is methylene chloride, 1,1,1-trichloroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, trichlorofluoromethane, dichlorodifluoromethane, chlorodifluoromethane, trifluoromethane, 1,2-dichloro 1,1,2,2-tetrafluoroethane, chloropentafluoroethane, 1,1,1-trifluoro 2,2-dichloroethane, 1,1,1,2-tetrafluoroethane, 1,1-dichloro 1-fluoroethane, 1-chloro 1,1-difluoroethane, 2-chloro-1,1,1,2-tetrafluoroethane, pentafluoroethane, tetrafluoroethane, trifluoroethane, difluoroethane, parachorobenzotrifluoride, cyclic, branched, or linear completely-methylated siloxanes, acetone, methyl ethylketone, methyl isobutylketone, trichloromethane, ethyl ether, diethyl ether, methanol, ethanol, pyridines, hexanes, benzene, and the like. Other solvents may also be useful. Acetone is the most preferred solvent since it is miscible with water, forms a minimal azeotrope with water, boils at about 55° C., and has a high affinity for wood, while also being an excellent solvent for VOCs. In a preferred embodiment, wood particulates are extracted by the method of the invention without predrying of the particulates. In this embodiment, a polar solvent or mixture of solvents or a hydrophilic solvent is preferred.
In accordance with the invention, solvents for the extraction of pitch are also exemplified by the group described above. However, since pitch is of higher molecular weight, these higher molecular weight extractives are best extracted with a less polar solvent or solvent mixture. Preferably, the solvent or solvent mixture is hydrophobic in nature, for example, kerosene, cyclic saturated alkanes, such as hexane, octane, and the like. Aromatic solvents, such as benzene, xylene and toluene, are also useful, but temperature and pressure conditions should be controlled to avoid significant dissolution of lignin. Such solvents are best employed after the wood has been dried to remove water that may interfere with extraction. Most preferably, however, the solvent is acetone, in which case the wood does not have to be dried and a single solvent may be used for the extraction of both VOCs and pitch. This also facilitates recovery of the solvent by eliminating any requirement for duplication of solvent recovery apparatus. Acetone also provides ease of separability from water, low boiling point, relatively low cost, low toxicity and a favorable environmental classification.
For ease of understanding the process of the invention, an embodiment of the invention is illustrated in FIG. 2. As shown, raw logs 50 are charged to a chipper 52 and then an optional chip crusher 53 for increase in internal surface area. In prior art processes, during the chipping, chip crushing and storage stages, VOCs are released and emitted into the surrounding environment. As explained above, the EPA has set stringent standards on the amount of VOCs that may be emitted. The chipping and chip crushing processes may, therefore, optionally be enclosed within substantially airtight, enclosed equipment from which air containing VOCs is continuously removed, through ducts under an induced draft. This VOC-containing stream may then be purified by passage through air scrubbers and then optionally activated charcoal filters, or through activated charcoal filters only.
Following the processing of solid product, the wood chips produced in crusher 53, are charged to an extraction operation 56 that removes pitch and VOCs from the wood chips. Preferably, this process is carried out in a counter-current operation. By "countercurrent" it is meant that the freshest solvent entering the extractor contacts chips that have already flowed through most of the extractor volume, and fresh chips entering the extractor first contact solvent that has already flowed through most of the extractor. Ideally, in this type of flow arrangement, influent solvent containing the lowest concentration of extractable material, contacts chips from which a proportion of the extractives have already been removed, so that the highest driving force for extraction is maintained. This driving force is proportional to the difference between the concentration of extractives in the solvent and the concentration of extractives in the wood chips.
In the wood chip extractor shown in FIG. 3A, the extractor has a cylindrical housing 300, preferably having a length-to-diameter ratio of about 4:1. Wood chips enter the compression screw feeder 302 that includes a progressively tapering screw thread within a sleeve. Thus, as the screw thread conveys the chips toward the extractor, the chips are progressively compressed in the tapering sleeve. This type of feeder is favored because it can express some water from the chips, facilitating subsequent solvent recovery. Any water expressed in the screw feeder is drained and removed in conduit 303 and routed to VOC, pitch and solvent recovery processes. The compressed chips enter the extractor near its top and flow downward under gravitational force, and the mass of chips continuously added to the extractor. The base of the extractor is supplied with a plurality of screw feeders 304 aligned with the longitudinal axes parallel to the base of the extractor. As these screw feeders 302 rotate about the axes, they convey the chips towards the outlet compression screw feeder 306. During compression of the chips in this outlet screw feeder, residual solvent is removed from the chips. This solvent drains into conduit 307 and is routed to a used solvent storage tank 308.
In order to remove wood extractives from the chips, solvent is added in at least two points in the extractor. In order to mimic, as closely as possible, countercurrent flow conditions, fresh solvent is injected near the base of the extractor; and "dirty" solvent that has already passed through the extractor, and that contains water and wood extractives, is injected nearer the middle or upper section of the extractor. Thus, dirty solvent is controlledly pumped from the used solvent storage tank 308 through outer concentric conduit 310 into the extractor at a location about midway along the length of the extractor. Flesh solvent is injected in an inner concentric conduit 312 that terminates near the base of the extractor. Thus, as fresh solvent rises in the extractor, moving toward the exit pipe 314, it encounters chips that have already undergone extraction with dirty solvent. Consequently, the chips with the lowest concentration of wood extractives come into contact with solvent having the lowest concentration of wood extractives. This provides an optimum driving force for further extraction of wood extractives from the chips. In the upper part of the extractor, entering chips, containing naturally occurring levels of wood extractives, first encounter dirty solvent. This dirty solvent is still able to extract wood extractives from the chips because of the high concentration of extractives present in the chips.
Ideally, flow of solvent in the extractor is of a plug-flow type. Thus, there is little mixing between fresh and dirty solvent in the portion of the extractor below the fresh solvent injection point. Under these circumstances, the fresh solvent rises in the extractor as a "front" until it meets with upwardly rising dirty solvent. At that point, commingling takes place and the combined solvent mass, including extracted wood extractives, rises upward through the extractor while leaching wood extractives from chips, until the solvent exits the extractor in conduit 314 and is routed to used solvent storage 308. A portion of this solvent is continuously removed and charged through conduit 60 to a solvent reclamation process.
In an alternative embodiment of the extractor according to the invention, shown in FIG. 3B, the extractor 320 has a cylindrical body inclined at an angle of about 60° to the horizontal. The extractor is supplied with an internal screw 322 that has a longitudinal axis extending along the central longitudinal axis of the extractor and that is coupled to a drive motor 323. Threads of the screw extend outward from the root of the screw at a screw pitch angle, toward the inner surface of the extractor body 320, without touching the inner surface. Thus, the inclined screw 322 is free to rotate, under mechanical power, within the extractor. Chips are fed into the solvent-filled extractor at an inlet near the extractor base by means of a compression screw feeder 324. These chips are captured between the helical threads of the rotating inclined screw of the extractor and conveyed upward until they are expelled from the extractor through a chip outlet 325 near the upper end of the extractor into an outlet compression screw feeder 326. As explained before, the outlet compression screw feeder compresses the chips and expresses residual solvent from the chips. In order to achieve near countercurrent conditions, acetone is injected into the inclined extractor through a conduit 327 near the top of the extractor, and removed from the extractor in an outlet conduit 328 near its base supplied with a chip filter 329.
In yet another embodiment of the chip extractor of the invention, shown in FIG. 3C, the extractor 330 is inclined at an angle of about 60°, and is supplied with an internal pan conveyor 332. As is conventional, the pan conveyor includes an endless belt extending substantially along the central axis of the extractor. Containers, or "pans," for carrying chips are formed along the belt by planar sheets, typically of metal, mounted on, and extending at right angles from, the belt at spaced intervals. The sheets extend toward, but do not touch the internal wall of the extractor. Thus, chips are captured in the spaces between the plates and are carried in the direction of movement of the belt. Chips are fed into the extractor inlet 335 by a compression screw feeder 334, located near the top of the extractor, on one side of the pan conveyor belt, and exit from the extractor through an outlet 336 on the opposite side of the pan conveyor belt, near the top of the extractor. The chips are carried away in a compression screw feeder 337. Solvent enters into the extractor through a conduit 338 near the outlet of the chips, and exits from the extractor through a conduit 340 near the chip inlet 335. Thus, the flow through the extractor is not completely countercurrent, but approximates countercurrent conditions for at least the partially-extracted chips on the exiting side of the pan conveyor.
In a further alternative embodiment of the chip extractor of the invention, shown in FIG. 3D, the extractor 350 is cylindrical (with a horizontal longitudinal axis) with a vee-shaped bottom to allow drainage of solvent. Thus, chips enter through an inlet 352 near one end of the extractor, fed by a rotary valve feeder 356. This type of feeder is an alternative that may also be substituted for the screw feeders shown at the chip inlets of the extractors of FIGS. 3A, B and C. The chips pour onto and are carried by a centrally-mounted longitudinally-extending pan conveyor 358 toward the opposite end of the extractor, while solvent is sprayed over the chips from solvent distributor 362. The chips exit off the end of the conveyer and fall into an exit chute 360. A compression screw feeder 364 then removes the extracted chips for processing into pulp. The solvent is removed through a conduit 366 that has a chip filter 365 and that is located at the base of the extractor.
As can be seen from the above, the extraction of wood extractives from wood chips may be achieved with a variety of extractor designs of the invention. The nature of wood chips, and wood particulates, impose certain limitations on the nature of the equipment. Wood chips, for example, tend to interlock and form stable packed structures when placed within a container, such as an extractor, or a silo. The above-described designs overcome this tendency by providing either inclined screws, pan conveyors, or screws near the base of the extractor to facilitate chip movement in the extractor and chip removal from the extractor. The designs, especially those of FIGS. 3B, 3C and 3D, also reduce channeling of wood chips from inlet to outlet of the extractor and facilitate control of chip residence time in the extractors.
In the extraction stage 58, the wood chips are immersed in the extraction solvent supplied in conduit 148 from solvent storage 146. Mild agitation, while preferred, is not necessary. During the immersion, solvent surrounds and penetrates the wood chips dissolving and leaching wood extractives, including VOCs and pitch, from the structure of the wood chip. Preferably, the solvent penetrates to and removes extractives from the resin canals of the wood as well as the parenchyma cells of the wood. This removal or "leaching" of extractives from the wood takes place under conditions of temperature and pressure that do not cause substantial attack of the ligninor cellulosic component of the wood. Thus, the high temperatures and pressures used in prior art processes designed to delignify wood or to pulp wood using solvents (omen in combination with catalysts) are not employed. Instead, the integrity of the cellulosic component is maintained as wood extractives are leached out. Moreover, the lignin component of the wood is also not affected, or only insignificantly affected, so that the wood particulates are not pulped. Only removal of a sufficient proportion of extractives to substantially reduce subsequent VOC release from the leached wood chips and to reduce the need for pitch-scale treatment chemicals in subsequent pulping operations, is required according to the invention. In certain instances, external heat may be supplied to facilitate leaching. Moreover, in certain instances, pressure may be applied in the extraction process to prevent vaporization of the solvent. However, in the preferred embodiment using acetone as a solvent, external heat may not be needed, nor may pressure have to be applied. Thus, the leaching or extraction can take place at ambient conditions of temperature and at about atmospheric pressure.
The extracted wood chips are separated from solvent in the extractor(s) and transported to optional chip pressing operations 62 for removal of residual solvent and extractives, for instance in screw presses. The solvent, containing water, pitch and VOCs, now called a "miscella" is removed in conduit 60 for processing to recover solvent for reuse, and pitch and VOCs for sale or combustion.
In the optional screw presses, the extracted wood chips are subjected to mechanical pressure causing squeezing and compression of the chips. As a result, residual solvent containing pitch is expressed from the chips. This liquid is conveyed in a conduit 63 to the solvent and pitch recovery processes, as will be described later. The compressed wood chips, still containing residual solvent, are charged to a solvent removal stage 66.
Solvent removal may be effected by conventional means, such as charging to a rotary drum dryer, or continuous dryers that comprise a multiplicity of drying stages enclosed in a housing and subjected to direct contact steam that removes solvent from a substrate to be dried. Solvent vapors removed during this stage are carried by conduit 68 to processes for solvent recovery. The substantially solvent-free leached chips, with reduced VOC and pitch content, are charged to board making or pulping processes, generally designated by the numeral 72. As a result of the extraction of VOCs and pitch, in the process of the invention, VOC emissions during the boardmaking or pulping operations are significantly reduced. Furthermore, as explained above, paper and absorbent product manufacturing processes are enhanced, by the virtual elimination of pitch that causes fouling of equipment and related loss in efficiency and production. The quality of paper and pulp products is also improved, as explained above. Further, if the chips are used in boardmaking, then bonding strength is improved so that board quality is enhanced while VOC emissions are substantially reduced.
In an important aspect of the invention, the extractive solvent used in the VOC and pitch extraction stage is recovered and recycled for reuse. As shown in the illustrative embodiment of FIG. 2, liquid streams 60, 63 and 68 containing solvent, from extractor(s) 56, optional chip pressing 62, and solvent removal 66, respectively, are gathered in header 70 which charges the solvent-containing fluids to a first distillation column 72. The distillation column preferably has three stages of separation, when acetone is used as a solvent. Clearly, the number of stages will vary depending upon physical properties of the extractive solvent used. However, the distillation column may be readily designed with the aid of commercially available multi-component distillation software, such as ASPEN PLUS, supplied by Aspen Technology Inc. of Cambridge, Mass.
In the embodiment shown in FIG. 2, distillation column 72, preferably under partial vacuum pressure, is supplied with steam 74 as a heating medium to raise the liquid in the base of the distillation column to a temperature at or above its bubble point. Under these conditions, vapors containing acetone, VOCs and some water vapor, rise to the top of the distillation column 72 and are removed in overhead conduit 80. These overhead vapors are condensed in cooler-condenser 76, supplied with water at about 20°-25° C. (or cooler) as a cooling medium. The cooler-condenser 76 may be of conventional shell and tube construction, plate and frame construction, and the like. Condensate is removed from the cooler-condenser in conduit 82 and is charged to a solvent, VOC and water storage tank 100.
A bottom product stream 78 is also withdrawn from the first distillation column 72. This bottom product stream contains a much lower proportion of solvent than the charge supplied to the distillation column in conduit 70, but yet contains some solvent, as well as water and pitch. In one embodiment, substantially all of the VOCs are removed in the overhead product from column 72. The substantially VOC-free bottom product is charged to a second distillation column 84 for recovery of solvent. This distillation column 84 is preferably also under partial vacuum, but a greater vacuum than in the first column, is supplied with heat, preferably through higher pressure steam than supplied to the first column, as shown by arrow 88. As a result of the higher temperature at the base of the distillation column and the increased vacuum, any remaining solvent is stripped from the charge to the distillation column. Consequently, a bottom product stream, substantially free of solvent and VOCs, is withdrawn from the distillation column in conduit 90 and charged to separator 120, as will be discussed later. An overhead product stream, containing mainly solvent, some water, and any residual VOCs, is removed from an overhead portion of the distillation column through conduit 86. This vapor stream is condensed in cooler-condenser 92. As before, the cooling medium in this cooler-condenser may be cooling water at about 20°-25° C., or colder. Condensate is carried from the cooler-condenser in conduit 94 and charged to the solvent, VOC, and water storage tank 100.
As explained above, the bottom product stream carried in conduit 90 from the second distillation column 84 contains an insignificant amount of residual solvent, in addition to pitch and water. This bottom product is charged to separator 120, preferably a heated tank, where heat is supplied by internal heating coils to raise the temperature of liquid to a temperature that favors separation of pitch and water, with the aid of a de-emulsifier, and that maintains the pitch in a pumpable viscosity range. Pitch separates from the water and accumulates in a layer. This pitch layer is then withdrawn in conduit 124 for potential sale. As an alternative, the pitch may be burned as a fuel since it has a heating value approximately 85% of that of No. 6 fuel oil. Mother product stream 126, containing mainly water, is also removed from the separator 120. This water is suitable for reuse within the process, as process water, or may be released to other mill uses or recycled back to 84 for further separation.
Rectifier 130 receives charge from the solvent, VOC and water storage tank 100. Thus, rectifier 130 is essentially utilized to separate solvent and VOCs from water, although minor quantities of pitch may also be present. Preferably, rectifier 130 is supplied with steam 134 near its base as a reboil heating medium. As a result of heating liquid in the base of rectifier 130 to its bubble point or above, a bottom product substantially free of VOCs and solvent is produced. This predominantly water-containing product stream is removed in conduit 132, for use in other mill processes or for separation in the separator 120, if it contains significant amounts of residual pitch.
At the same time, the rectifier also produces an overhead product, rich in solvent, that is removed in conduit 136 and charged to a cooler-condenser 140. In this cooler-condenser, the solvent is condensed and the condensate is transported away in conduit 138 to dry solvent storage 146 for reuse in the extraction process. A side drawoff stream from the rectifier 120, containing mainly VOCs, is cooled in cooler 148 and the cooled liquid is routed through conduit 144 to VOC storage tank 150. The stored VOCs are routed to a combustion process 154 for disposal or to sales.
In an alternative, preferred embodiment, the VOCs are produced as two separate products. With reference to FIG. 2A, the first distillation column 72 produces an overhead product cooled in cooler condenser 76, containing light VOCs (LVOCs) that is stored in LVOC, solvent, and water storage tank 200. The second distillation column 84, produces an overhead product condensed in cooler condenser 92 containing heavier VOCs (HVOCs), and water. Consequently, instead of combining the overhead products by charging both to a single solvent, VOC and water storage tank, the overhead products are kept separate and are charged to separate storage tanks. This allows the production of separate LVOC and HVOC products. In order to produce the separate products, the mixture of LVOCs, solvent and water from storage tank 200 is charged to a rectifier 210 for separation into a bottom stream 218 containing mainly water is routed to reuse or disposal. A middle drawstream 222 containing mainly solvent is condensed in a condenser 220. The condensed solvent is routed to the dry solvent storage tank 146, as in the process described in FIG. 2. Referring again to FIG. 2A, an overhead LVOC product of the rectifier 210 flows through conduit 212 to cooler-condenser 214. The condensed LVOC product is stored in an LVOC storage tank 216.
The HVOC product is produced by charging the mixture in storage tank 202 to a rectifier 224. In this rectifier, the mixture is separated into an overhead product, containing mainly solvent, that is cooled and condensed in a condenser 226 before being charged to dry solvent storage tank 146. A mid-column drawoff stream, containing mainly HVOCs, is cooled in a cooler 228 and then routed to HVOC product storage tank 230. The rectifier bottom product, carried in conduit 232, contains mainly water and pitch. This mixture is routed in conduit 232 to a heated de-emulsifier tank 234 where the pitch separates from the water. The pitch is removed in conduit 233, for sale or use as fuel, while the water is routed in conduit 235 for use in the process, or disposal.
Clearly, the process described in FIG. 2A can also be operated with a single rectifier operating on two cycles. In one cycle, the rectifier is used to separate the mixture from tank 200 into LVOCs, water and solvent. In another cycle, the rectifier is used to separate the mixture from storage tank 202 into HVOCs, solvent and water. Storage tank sizing and distillation columns 72 and 84 overhead product volumes dictate the length of each of the cycles.
In a further alternative more preferred embodiment, shown in FIG. 2B, the rectifier 130 has an overhead product drawoff, two side product drawoff streams, and a bottom product stream. The overhead stream is rich in LVOCs; an upper near-top-column drawoff stream is rich in solvent; a lower near mid-column draw off stream is rich in HVOCs; and the bottom stream is substantially free of VOCs and solvent but contains pitch and water. This clearly assumes that the boiling point of the selected solvent is intermediate the LVOCs and the HVOCs. If not, then the drawoff configuration may readily be altered to accomplish the separation. Regardless, in the type of rectifier, pump arounds may have to be installed in order to remove or add heat to the distillation column to facilitate separation between the LVOCs, HVOCs, and solvent. The function of these pumparounds is to controlledly modify the temperature profile of the distillation column, thereby facilitating separation of LVOCs and HVOCs and solvent. A person of ordinary skill in the art, having read this disclosure, and having access to distillation column design software, such as the software named above, would readily be able to design a rectifier with appropriate pumparound volume and temperature to achieve the separation.
It is important to note that the volatile organic compound product produced, and the pitch product produced, are not necessarily "pure." Rather, the VOC product may contain at least some, although minimal, amount of solvent, as well as water. Preferably, the amount of solvent in the VOC product is minimized to reduce the cost of adding makeup solvent to the process. Nevertheless, at least some proportion of the solvent will be lost in the VOC, and possibly pitch, products for economical distillation operation.
The pitch product will contain pitch as well as water. Pitch by itself solidifies at room temperature and is difficult to handle. While the pitch may be spray-dried into pellets for handling, it is preferred that the pitch product contain less than about 50 wt % solids so that it may be maintained in a liquid state, either at ambient temperature or with the addition of economically minor amounts of heat or waste heat. This liquid pitch product is more readily pumped into heated tank cars for sale.
The process of the invention removes volatile organic compounds from wood particulates thereby allowing processing of these wood particulates without the release of VOCs into the environment. Moreover, the process of the invention removes pitch from wood particulates thereby facilitating further processing of the wood particulates into useful products. Further, the invention provides two additional useful products, namely, VOCs and pitch, that may be sold as byproducts or used as fuel, thereby enhancing the economics of the process of the invention.
The following examples are illustrative of aspects of the invention and do not in any way limit the scope of the invention, as described above and claimed herebelow.
EXAMPLES
Example 1
Comparison of Solvents for the Removal of Wood Extractives
A series of solvents were tested to determine which was most effective for the extraction of wood extractives, including volatile organic compounds and pitch. In each of the tests, 50 gram batches of oven dried Lodgepole Pine wood chips were extracted with solvent at a solvent:wood mass ratio of 4:1. Samples of each batch were each analyzed for wood extractives, using a modified TAPPI test method T204 om88 with diethyl ether as the extraction solvent, before and after extraction with the test solvents.
In each case, the batch of wood chips was subjected to a batch extraction process. The wood chips were not predried, so that their condition approximated that of wood chips normally received for treatment in a wood pulping facility, or used in a composite wood product manufacturing facility. The wood chips were preheated with atmospheric steam for 30 minutes. During this time, the wood chip temperature rose to about 95° C. The wood chip batch was then immediately submerged in the extraction solvent. In each case, the solvent:wood ratio was 4.0 and the extraction time was 30 minutes. After extraction, solvent was drained from the chips, and the chips were subjected to a second heating cycle of 30 minutes with atmospheric steam. Thereafter, the chips were subjected to a second extraction cycle using the same solvent at the same solvent:wood ratio. After draining solvent from the chips, the chips were analyzed to determine the amount of residual wood extractives. The percent wood extractives removed was calculated for each batch and the results are reported in the accompanying Table 1.
TABLE 1______________________________________Treatment Solvent Percent Extraction______________________________________Peracetic Acid 45.8Caro's Acid 14.2Hypochlorous Acid 37.5Deionized Water 41.0Acetone/Water 80/20 54.4Acetone 100% 65.0______________________________________
These results indicate that acetone is the best solvent for the removal of wood extractives from Lodgepole Pine. Acetone has advantages over the use of an 80/20 acetone/water mixture, and is also superior to the other solvents tested. It is theorized, without being bound, that oxidized acids (or alkaline reagents), depend upon chemical reactions that convert wood resins in order to achieve extraction. Not only is this from a thermodynamic perspective not as effective as direct solution of the extractives in an organic solvent, but alkaline extractions have several disadvantages. These include the darkening of wood fibers which would result in higher fiber bleaching costs. Moreover, the nonselective nature of caustic treatments result in loss of yield. Also, caustic extracts are extremely toxic and costly to treat.
Example 2
Process Conditions for the Removal of Wood Extractives
A series of acetone extractions were conducted to determine conditions suited for the efficient removal of wood extractives. In each case, a 50 gram batch of oven dried wood chips was treated in a solvent:wood ratio of 4.0. The wood chip species evaluated were seven batches Ponderosa Pine (PP) and four batches of Douglas Fir (DF) as well as a PP control batch. During the extraction processes, steam preheating time, acetone extraction time, and post-steaming times were varied. Steam was supplied at ambient pressure, and the extractions were carried out at ambient temperatures and pressures. In each case, the extracted wood chips were finally squeezed in a press at 1500 psi for 5 minutes. A modified TAPPI test method, T204 om88, using diethyl ether as the extraction solvent, was used to determine the percentage of wood extractives removed from the samples. The results are shown in Table 2.
TABLE 2__________________________________________________________________________ Steam #1 Extraction #1 Steam #2 Extraction #2 Press Extractiontime, minutes 0 15 30 15 30 0 15 30 15 30 5 %__________________________________________________________________________PP1 X X 62.5PP2 X X X 48.6PP3 X X X 53.3PP4 X X X 64.6PP5 X X X X X 58.5PP6 X X X 78.2PP7 X X X X X 73.0Control PP H.sub.2 O X 17.6DF X 48.5DF X X 53.6DF X X X X 54.2DF X X X X 57.4__________________________________________________________________________
From the above table, presteaming with atmospheric steam did not appear to enhance extraction. Indeed, presteaming appears to reduce extraction. While multi-stage extractions show slight increases in overall extraction, this increase may not justify the additional equipment required in a commercial operation. Increasing the extraction time, in a single- or multiple-stage extraction, is effective in increasing the percent wood extractives removed.
Example 3
Variation of Percentage of Wood Extractives Removed with Extraction Time, Using Acetone as a Solvent
A batch of Lodgepole Pine chips was sampled and tested as described in TAPPI T204 om88, modified to use diethyl ether as a solvent, to ascertain the amount of wood extractives in the chips. Then, samples of the chips were each treated with acetone for 3, 5, 10, and 20 minutes, respectively. Each extracted chip sample was then air dried, ground to 1 mm size particulates, and extracted in the same modified TAPPI method to determine residual wood extractives. The percent wood extractives removed was calculated for each extracted sample and the results were tabulated in Table 3.
TABLE 3______________________________________Time of EtherExtraction Extractables Extraction(min) (wt. %) %______________________________________0 2.9 03 2.3 215 1.9 3510 1.5 4820 0.75 74______________________________________
The results show that wood extractives were reduced from 2.9% in the raw Lodgepole Pine chips to 0.75 wt. % in 20 minutes. This represents an extraction of about 75% of the wood extractives. Moreover, after only 5 minutes, 35% of the wood extractives have been removed. Tests indicated that volatile organic compounds were virtually completely removed from the chips, even after only 5 minutes. Thus, longer extraction time are only needed if it is desired to remove increasing quantities of pitch. It is theorized, without being bound, that lower molecular weight wood extractives are more soluble and are therefore extracted at a faster rate than the higher molecular weight components. Consequently, VOCs are first removed, followed by those wood extractives that are likely to become volatilized under wood chip pulping conditions, and composite board making conditions. Therefore, extraction need only proceed to remove these components, unless higher molecular weight, less soluble pitch must also be removed for other purposes.
Example 4
Comparison of Alternative Solvents for the Removal of Wood Extractives
A series of wood chip extractions were conducted with organic solvents to determine their relative ability to leach extractives from wood. The solvents include methanol, ethanol, 2-propanol, methyl iso-butyl ketone, hexane, acetone, and water.
Samples of raw Lodgepole Pine wood chips were each extracted according to TAPPI T204 om88, modified to use diethyl ether as a solvent, to determine initial wood extractives content. In a first comparison, batches of wood chips were each extracted with a specific solvent, at its boiling point, for either 20 minutes or 4 hours, respectively. The extracted wood chips were then air dried, ground to 1 mm size, and again extracted with diethyl ether, in the modified TAPPI test method T204 om88, to determine residual wood extractives.
A second set of wood chip samples were first air dried, then ground to 6 mm particle size, before being extracted for 4 hours at the solvent boiling point. Thereafter, the extracted wood particulates were ground to 1 mm size, and extracted with diethyl ether, as above, to determine residual wood extractives.
Finally, samples of wood meal were also extracted with each solvent for 4 hours at the solvent boiling point to determine the limit of wood extractives removal achievable with the particular solvent. The percentage of wood extractives removed in each extraction was calculated and the results are tabulated in Table 4.
TABLE 4______________________________________ % Extractives Removed 20 minute 4 hour 4 hourExtraction Reflux Reflux RefluxConditions chips chips woodSample Type 6 mm 6 mm meal______________________________________Methanol 68 75 95Ethanol 62 73 962-Propanol 66 75 94Acetone 67 75 96Methyl Isobutyl Ketone 41 70 96Hexane NA 18 86Water 21 17 38______________________________________
As can be seen from the above table, the hydrophilic solvents appear to be superior to the hydrophobic solvent, hexane, as an extraction solvent. Moreover, percent extraction increases with time of extraction, although the increase is small relative to the increase in time required. Methanol and acetone appear to be the best solvents. However, methanol poses toxicity issues.
Based on the percentage extraction achieved with wood meal, the practical upper limit of wood extractive removal appears to be about 95%. However, as explained before, virtually all volatile organic compounds will be removed, and the residual wood extractives are expected to comprise only the higher molecular weight, and specifically, more hydrophobic, wood extractive components.
Example 5
Determination of the Effect of Wood Particle Size and Handling Conditions on Removal of Wood Extractives
In order to test the effect of particle size, wood chips were treated in equipment that would either (1) reduce average particle size or, (2) cause fractures in the wood chips opening internal surfaces and reducing average chip thickness. A batch of chips was treated with a Rader DynaYield Chip Conditioner, designed to squeeze those wood chips that have a thickness greater than 1.5 mm. In this conditioner, the greater the thickness of the charged wood chip, the more work is applied to the wood causing delamination along the wood grain. In effect, this reduces the apparent particle thickness without significantly decreasing chip size or integrity.
Another batch of chips was treated in a Prex screw press. This equipment causes a larger size reduction. However, it is also known that the quality of pulp produced from chips treated through a screw press, or like equipment, such as the Sprout-Bauer Pressifine, French Oil Press, and Prex screw is minimally affected.
A sample of the wood chips was extracted using TAPPI T204 om88 test method, modified to use diethyl ether as a solvent, to determine the percent wood extractives present. Those chip batches treated in the Rader Chip Conditioner and the Prex screw feeder and a control batch were each separately extracted with acetone, under the same conditions of concentration, solvent:wood ratio, temperature and pressure. A sample of the extracted chips was again analyzed by the TAPPI method to determine residual wood extractives. The percentage of wood extractives removed was calculated. The results are shown in Table 5.
TABLE 5______________________________________Wood Chip Size Control Chip Rader Conditioner Prex Screw______________________________________Over Thick > 10 mm 60% 72% --<10 mm 58% 78% 84% <6 mm 65% 67% 88%Pins 82% -- --Fines 91% -- --______________________________________
As shown in the table, treating chips in a Rader conditioner allows some increase in the removal of wood extractives, especially for larger size wood chips. This is to be expected, since fracturing the larger wood chips allows better penetration of the solvent into the interior of the chip.
The effect of increased extraction is even greater with chips treated with the Prex Screw equipment. Again, this is explained by the greater degree of size reduction and fracturing of the chips that is achieved with this equipment that facilitates penetration by the solvent into the chip and removal of wood extractives.
While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
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A process for extracting volatile organic compounds and pitch from wood particulates, thereby virtually eliminating the emission of volatile organic compounds into the atmosphere during the processing of wood particulates into commercially useful products, such as oriented strandboard, particle board, chipboard veneers, and pulp and paper products. The removal of pitch permits the production of pulps of higher brightness, requiring less chemical bleaching agents. Moreover, removal of pitch eliminates pitch scale formation in pulp mills and on pulp and paper machines with resultant improved efficiencies and reduced use of pitch treatment chemicals. In the extraction process, a solvent or blend of solvents, leach wood extractives, including volatile organic compounds and pitch, from the wood particulates to produce a miscella. The miscella is separated from the leached wood particulates and solvent contained in the miscella is recovered and recycled for reuse. The wood extractives of the miscella may be sold as chemical feedstocks or used as a fuel. Any volatile organic compounds released as vapors in wood processing operations prior to the extraction step are collected, absorbed onto activated carbon particulates, and recovered for sale or combustion.
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This applicational is a divisional of Ser. No. 07/514,700, now U.S. Pat. No. 5,291,667.
BACKGROUND OF THE INVENTION
The present invention relates to a control system and method for the operation of a clothes dryer.
It is well known to provide clothes dryers with a lint filter to remove lint picked up from the articles or load being dried. If the filter becomes clogged by excessive lint, the airflow through the dryer is restricted and the necessary time to dry the load is increased.
The status of the lint filter may be monitored by means of airflow and pressure sensors that provide indication of blockage during the time air is flowing through the dryer. Typically, serious blockages of airflow result in excessive temperatures in the area of the air heater, resulting in the intermittent opening of a high limit thermostat that deactivates the heater. The sensors or thermostats can be connected to an indicator to apprise the operator of the condition. However, these methods provide an indication of air blockage only during airflow through the dryer.
It is desirable to know the degree of dryness of the load. This is useful for operator removal of the load at a given dryness or for helping the operator predict the time remaining to dry.
The dryness of the load may be monitored by such means as sensing the rapid rise in exhaust temperature when the load is nearly dry and by actual humidity sensors. Unfortunately, the monitoring of exhaust temperature does not provide entirely satisfactory results and humidity sensors represent a substantial increase in sensor costs.
SUMMARY OF THE INVENTION
The present invention provides a simple, integrated means for alerting the operator that an air blockage has occurred and for indicating the degree of dryness exhibited by the load. In addition, the operator is provided with an estimated drying time, allowing convenient scheduling and planning.
The dryer control system for a dryer including a heater, an air inlet receiving air from the heater, and an air exhaust exhausting the air from the dryer comprises: a control means; an inlet temperature measuring means connected to the control means; an exhaust temperature measuring means connected to the control means; an estimated drying time display means connected to the control means; a dryness display means connected to the control means; and a blockage indicator means connected to the control means. The control means samples the inlet temperature at a first and second time, samples the exhaust temperature at a first and second time, forms a first difference between the second and first inlet temperatures, forms a second difference between the second and first exhaust temperatures, calculates the estimated drying time as a function of the first and second differences, and displays the estimated drying time on the estimated drying time display. Also, the control means monitors the inlet temperature, increments a number each time the inlet temperature exceeds a predetermined value, and activates the blockage indicator means when the number exceeds a predetermined threshold. In addition, the control means monitors the exhaust temperature, deactivates the heater when the exhaust temperature exceeds a predetermined maximum exhaust temperature, activates the dryness display means when the inlet temperature drops below a predetermined inlet temperature, and activates the heater when the exhaust temperature drops below a predetermined minimum exhaust temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a clothes dryer according to the invention.
FIG. 2 is a flow chart diagram of a method according to the invention for detecting an air blockage in the dryer.
FIG. 3 is a flow chart diagram of a method according to the invention for measuring the dryness of a load in a dryer.
FIG. 4 is a flow chart diagram of a method according to the invention for estimating the drying time for a load in a dryer.
FIG. 5 is a flow chart diagram of a method according to the invention for detecting an air blockage, measuring the dryness of a load in the dryer, and estimating the drying time for the load.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A clothes dryer 10 according to the invention is shown in FIG. 1. A heater 12 provides heated air to a load 14 of clothes or other articles. The heater 12 may be, for example, of the resistive electric type or the combustion type.
After moving about the load 14, the air is exhausted from the dryer 10. The temperature 16 of the inlet air and the temperature 18 of the exhaust air is measured, for example, by thermistors or resistors with known temperature/resistance characteristics.
The temperatures 16, 18 are provided to a controller 20. In the preferred embodiment, the controller 20 comprises a microprocessor which is programmed to perform the functions described below. The controller 20 also includes the necessary support circuitry to activate and deactivate the heater 12 and to monitor the temperatures 16, 18.
In addition, the controller 20 controls the display of information on a time to dry display 22, a dryness display 24, and an air blockage indicator 26.
The time to dry display 22 may be, for example, a numeric display of the vacuum fluorescent type. The air blockage indicator 26 may be, for example, a simple signal light or it may be an indicia such as "CLEAN FILTER" on a vacuum fluorescent display. The dryness display 24 may be, for example, a vacuum fluorescent display capable of displaying a series of numerical or word indicia indicating dryness, or a series of lights capable of being sequentially activated, each member of the series indicating a level of dryness. Alternatively, the dryness display 24 may be, for example, a single light that simply indicates that the load 14 is dry.
FIG. 2 shows a flow chart of a method for detecting an air blockage according to the invention. Initially, all variables are initialized and the heater 12 is activated. The controller 20 compares the measured inlet temperature 16 to an inlet high limit temperature T IH . This temperature may be, for example, 150° C.
If the inlet temperature 16 is greater than T IH , the variable COUNT is incremented. In the preferred embodiment, the heater 12 is also deactivated at T IH to prevent excessive temperatures about the heater 12. If desired, the heater 12 could be deactivated at some higher temperature and still provide the desired protection.
If COUNT is equal or greater than a threshold N (e.g. 2), the blockage indicator 26 is activated and remains so whether air is flowing through the dryer 10 or the heater 12 is on or off.
In this way, the operator has a much better opportunity to notice the blockage indicator 26.
When the inlet temperature 16 drops below an inlet low limit temperature T IL (e.g. 100° C.) the heater 12 is reactivated and the process continues.
FIG. 3 shows a flow chart of a method according to the invention for measuring the dryness of the load 14 in the dryer 10. Initially, all variables are initialized and the heater 12 is activated. The controller 20 compares the measured exhaust temperature 18 to an exhaust high limit temperature T EH . This temperature may be, for example, 55° C. for cotton or 40° C. for knits.
If the exhaust temperature 18 exceeds T EH , the heater 12 is deactivated. The controller 20 then compares the measured inlet temperature 16 to a threshold dryness temperature T ID . This temperature may be, for example, 55° C.
If the inlet temperature 16 drops below T ID , the dryness display 24 is incremented (e.g. either a numerical value is incremented, or a light in a sequence is illuminated) and the DRY FLAG is set. If a simpler display is desired, the dryness display 24 may simply provide the same indication after the first time it is activated until the variables are again initialized.
Whether the inlet temperature 16 drops below T ID , or not, the exhaust temperature 18 is monitored by the controller 20. If the exhaust temperature 18 drops below an exhaust temperature lower limit T EL (e.g. 30° C. for cotton or 25° C. for knits), the cycle starts over. Otherwise, if the DRY FLAG is set, the controller 20 continues to monitor the exhaust temperature 18 with respect to T EL . If the DRY FLAG is not set, the controller 20 goes back to monitoring the inlet temperature 16.
If the incrementing display is used, the dryness display 24 indicates successively dryer states of the load 14 as operation of the dryer 10 continues. This allows the operator to remove the load 14 at a given dryness, or estimate the remaining time required.
There is a correlation between the inlet and exhaust temperatures 16, 18 near the beginning of a drying cycle to the time required to dry the load 14. It has been found that a linear equation using the inlet and exhaust temperatures 16, 18 provides a good estimate of the drying time required for the load 14.
The inlet temperature 16 is measured at the start of the drying cycle to give a value T IO and at a time t m to give a value T Im . The time t m may be, for example, 3 minutes into the drying cycle.
Similarly, the exhaust temperature 18 is measured at the start of the drying cycle to give a value T EO and at the time t m to give a value T Em . It would of course be possible to use a time near the beginning of the cycle other than t m .
It has been found that the following equation provides a good estimate of the required drying time D:
D=K+W.sub.I (T.sub.Im -T.sub.Io)+W.sub.E (T.sub.Em -T.sub.EO)
where K, W I , and W E are constants that depend on the type of load 14 being dried.
For example, if D is measured in seconds, the temperatures measured in Celsius degrees and t m =3 minutes, the following values may be used:
COTTON: K=3809, W I =7.19, and W E =-87.7
PERMANENT PRESS: K=2232, W I -11.5615, W E =-108.25
FIG. 4 shows a flow chart of a method according to the invention for estimating the drying time required for a load 14.
Initially, the inlet temperature 16 is stored to T IO and the outlet temperature 18 is stored to T EO . All steps are then bypassed until the time, t, into the drying cycle equals t m . Then the inlet and exhaust temperatures 16, 18 are measured again and the calculation described above performed to find the estimated drying time.
The calculated drying time is then displayed on the time to dry display 22. The time displayed may be the estimate itself, the estimate minus the elapsed time, or, with a time of day clock added, the estimated time of day for completion.
By having the estimated drying time, the operator can have a general idea of when the load 14 will be complete. During a cycle where the clothes may need to be removed right away to avoid wrinkling, if the cycle is completed earlier then the estimated time, the load can be periodically tumbled to balance out the remaining time.
FIG. 5 shows a flow chart combining the above-described methods into a single method according to the invention for providing a coordinated, single control system for the dryer 10. The block labeled DRY TIME ROUTINE performs the method set forth in FIG. 4.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
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A control system for a clothes dryer is disclosed. A microprocessor monitors the heated inlet air temperature and the exhaust temperature. If the inlet temperature exceeds a high limit value a given number of times, an air blockage indicator is activated. Degrees of dryness are measured by the number of times the inlet temperature has dropped below a threshold value while the heater is off because the exhaust temperature has exceeded a desired value. An estimated drying time is calculated and displayed to the user based on a linear function of the inlet and exhaust temperatures measured at the beginning of the cycle and again a short time later.
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CLAIM OF PRIORITY
This application claims priority to an application entitled “METHOD FOR ASSIGNING WAVELENGTHS IN WAVELENGTH DIVISION MULTIPLEXING RING COMMUNICATION NETWORKS,” filed in the Korean Intellectual Property Office on Jul. 27, 2002 and assigned Serial No. 2002-44403, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical communication network, and more particularly to a method of setting-up optical paths and assigning wavelengths with a minimum number of wavelengths in a wavelength division multiplexing (WDM) ring communication network.
2. Description of the Related Art
An optical ring network using a wavelength division multiplexing (WDM) is a network topology that is popular because of its easiness of establishing a network. It is also has the additional advantages of being able to swiftly recover from network-cut failures and its low start-up cost. This has led to the increased worldwide use WDM ring networks.
Conventional WDM ring communication networks provide every node forming part of the network with full-mesh connectivity. Such optical ring networks use wavelengths from two optical fibers in order to form optical paths between each two nodes. The two optical fibers include both a forward-direction optical fiber link through which an optical signal travels in the clockwise direction and a backward-direction optical fiber link through which an optical signal travels in the counterclockwise direction.
When the optical rink network is established, the setting of optical paths is performed, considering facts such as swift recovery from network-cut failures, the number of wavelengths required to realize full-mesh connectivity network, and network extensions.
The set-up process usually gives particular attention to configuring optical paths and assigning wavelengths with a minimum number of wavelengths. In such a process, a network with full-mesh connectivity can be established with a smaller number of wavelengths, and therefore the network can have a larger transmission capacity. Although, when new nodes are added to such an optical ring network, it is necessary to minimize change of the configuration of the already-existing network in forming optical paths between nodes.
FIG. 1 is a block diagram showing a ring communication network 10 including five nodes 11 - 15 with full-mesh connectivity. In such a communication network with full-mesh connectivity, an optical path must be provided between any two nodes. The ring communication network 10 includes a pair of optical links. One optical link is a forward-direction optical fiber link through which an optical signal travels in the clockwise direction, and the other is a backward-direction optical fiber link through which an optical signal travels counterclockwise direction. A number of channels are multiplexed in each optical fiber link using a wavelength division multiplexing method.
In the ring communication network 10 , it is necessary to minimize the number of wavelengths required for achieving full-mesh connectivity. Accordingly, a method of forming optical paths using a minimum allowable number of wavelengths and a method of assigning wavelengths to each optical path should be used. In addition, when wavelengths are assigned to each optical path in the ring communication network 10 , it is necessary that optical paths sharing the same optical fiber link not use the same wavelength.
To accomplish this, a lower limit value of the number of wavelengths required to configure the ring communication network 10 must be determined. This is assuming that the optical path formed between two nodes is the shortest possible path there between. In this regard, referring again to FIG. 1 , an optical path from a node 1 to a node 3 is not formed in the counterclockwise direction, but in the clockwise direction. This method of forming the optical path is reasonable because it utilizes available resources optimally. Under this assumption, the following facts can be obtained. First, the maximum distance Lmax between any two nodes is (N−1)/2 when N is an odd number, and N/2 when N is an even number. Here, the term “distance” means the number of “hops”, i.e., the number of nodes between any two nodes, and therefore the distance between two neighboring nodes becomes 1.
There are many ways of expressing optical paths formed between each two nodes, for an example, a matrix expression method proposed by Ellinas is used in the following description of the optical paths (See, e.g., G. Ellinas, K. Bala and G.-K. Chang, “A Novel Wave-length Assignment Algorithm for 4-fiber WDM Self-Healing Rings,” Proc. of ICC ' 98, 1998, pp. 197-201.)
FIG. 2 is a block diagram of a conventional method for assigning wavelengths in a ring communication network 20 including four nodes 21 - 24 . In this configuration, when the number of nodes is 4, the maximum distance is 2. An optical path 25 may be formed between a node 1 and node 3 using a wavelength W 1 in the clockwise direction, and an optical path 26 may be formed between a node 2 and a node 4 using the same wavelength W 1 in the counterclockwise direction.
In the case where the number of nodes is an even number and not a multiple of 4, (the number of nodes becomes a multiple of 4 if two nodes are not considered), the number of wavelengths required in such a case can be obtained by adding one to the number of wavelengths required when the number of nodes is a multiple of 4. Accordingly, when an optical path is formed between each two nodes using the shortest path, the minimum number of wavelengths required is (N2−1)/8 when the number of nodes N is an odd number, N2/8 when the number of nodes N is an even number and a multiple of 4, and (N2+4)/8 when the number of nodes N is an even number but not a multiple of 4.
However, these calculations do not consider a requirement in forming the optical paths that optical paths sharing the same optical fiber link must have different wavelengths, and therefore the values obtained by the calculations are a lower limit value of the required number of wavelengths.
FIG. 3 is a block diagram a conventional method for assigning wavelengths in a ring communication network 30 including five nodes 31 - 35 . In FIG. 3 , an optical path 36 is formed from nodes {A, B, D} to nodes {B, D, A}, using a wavelength W 2 , and the optical path 36 may be expressed by a matrix in the following table 1.
TABLE 1
A
B
C
D
E
W2
1
2
X
2
X
In table 1, each numeral indicates a length of the corresponding optical path (the number of hops between two nodes). Accordingly, “1” in the first column means that an optical path is formed from the node A to the node B, and “2” in the second column means that an optical path is formed from the node B to the node D. “X” in the third column means that no optical path is formed, starting from the node C using the wavelength W 2 . In such a manner, optical paths formed using each wavelength can be easily expressed. The matrix of expressing the formed optical paths has the following requirements. One requirement is related to the row and the other the column.
Requirement in the Row
1. When there is a numeral “K” in a position (i, j), only X exists between positions (i, j) and (i, (j+K) mod N). This requirement means that when optical paths share the same optical fiber link, they cannot use the same wavelength.
2. The summation of all values in one row is N. This requirement means that utilization of a given number of wavelengths should be optimized.
Requirement in the Column
1. There is no same value in one column. Existence of the same value means that a plurality of optical paths is formed between two nodes. Therefore, in order to minimize the minimum number of wavelengths, one column should have no two values the same.
2. One column should have all values, from 1 to Lmax. Here, Lmax denotes the maximum distance. This means that full-mesh connectivity should be satisfied. However, this requirement is satisfied only when the number of nodes is an odd number, and may not be satisfied in some matrixes when the number of nodes is an even number. In particular, in this case, the two most-distant nodes to be connected by an optical path formed in one optical fiber link may be also connected by another optical path formed in the opposite optical fiber link, and therefore the optical path interconnecting the most-distant nodes may not be formed in the one optical fiber link. However, this requirement should be satisfied when the number of nodes is an odd number.
Accordingly, when the optical paths are expressed with a matrix, such requirements can be used to check whether the wavelengths are assigned suitably.
The wavelength assignment method proposed by Ellinas may be classified into three cases: (I) when the number of nodes is an odd number, (II) when it is an even number, and (III) when the number of nodes is increased.
I. The Wavelength Assignment Method when the Number of Nodes is an Odd Number
The method for assigning wavelengths when the number of nodes is an odd number may be expressed by a matrix as follows.
1. A matrix is prepared where the number of columns is equal to the number of nodes, and the number of rows is equal to the lower limit value of the number of wavelengths required when the number of nodes is N.
2. A set of numerals {1, 2 . . . Lmax} are sequentially assigned to locations of the first column. “X” is written in each empty locations of the first column, assigned no numeral. When a numeral is assigned to a location in the first column, a number of X's equal to the hop number represented by the numeral minus 1 are written in locations to the right of the numeral and in the same row as the numeral.
3. A set of numerals {Lmax, 1 . . . 2}, obtained by rotating the set of numerals {1, 2 . . . Lmax} used in the first column, are sequentially assigned to locations of the second column. However, no numeral is assigned to locations in the second column where “X” is already written. In addition, “X” is assigned to empty locations of the second column.
4. In the same manner, a set of values, obtained by rotating the used set, are assigned to locations of the next columns, and “X” is assigned to empty locations with no numeral assigned. This procedure is repeated until the matrix is completed.
Illustratively, when this method is applied to a ring communication network having 7 nodes (i.e., N=7). Because N is 7, the number W of wavelengths is (7 2 −1)/8=6, and the maximum distance is (7−1)/2=3. The following table 2 shows a completed matrix in such a case.
TABLE 2
A
B
C
D
E
F
G
W1
1
3
X
X
3
X
X
W2
2
X
2
X
1
2
X
W3
3
X
X
1
2
X
1
W4
X
1
3
X
X
3
X
W5
X
2
X
2
X
1
2
W6
X
X
1
3
X
X
3
As shown in table 2, a set of numerals {1, 2, 3} are assigned to locations of the first column, and a rotated set of numerals {3, 1, 2} are assigned to locations of the second column. The reason why no numeral is assigned to the second and third rows of the second column is that numerals 2 and 3 are assigned to their previous columns (the first column), respectively, and this means that the corresponding wavelengths are already used there.
II. The Wavelength Assignment Method when the Number of Nodes is an Even Number
When the number of modes is an even number, the above-mentioned method cannot be used. Instead, after the wavelength assignment method is performed for a communication network including an odd number (N−1) of nodes, the number of nodes is increased. However, there is a little difference in this method between the case where the number of nodes is a multiple of 4 and the other cases.
II-1. The Wavelength Assignment Method when the Number of Nodes is an Even Number and Also a Multiple of 4
1. A matrix expressing the wavelength assignment in the case where the number of nodes is N−1 is formed.
2. A column is added at any position, extending the number of columns.
3. Tracking to the left from the added column, a first encountered numeral for each row is selected. That is, for each row, a numeral on the left nearest to the added column is selected.
3-1. If the value of the selected numeral is not Lmax, the value is increased by 1, and “X” is written in the corresponding row of the added column.
3-2. If the value is Lmax, the value is decreased by q, and “(q+1)” is written in the corresponding location (row) of the added column. Here, q represents the number of Xs that are passed by when tracking to the right from the added column until a first numeral is encountered. That is, q means the number of Xs that exist between the added column and a numeral on the right nearest to the added column.
3-3. A number of new rows equal to (N/4) are added, and longest optical paths having the maximum distance are formed using the new wavelengths corresponding to the added rows.
Illustratively, when such this method is applied to a communication network having 8 nodes, the following table 3 is obtained. In table 3, a node E is added between nodes D and F.
TABLE 3
A
B
C
D
E
F
G
H
W1
1
3 → 3
X
X
1
3
X
X
W2
2
X
2 → 3
X
X
1
2
X
W3
3
X
X
1 → 2
X
2
X
1
W4
X
1
3 → 2
X
2
X
3
X
W5
X
2
X
2 → 3
X
X
1
2
W6
X
X
1
3 → 1
3
X
X
3
W7
4
X
X
X
4
X
X
X
W8
X
X
4
X
X
X
4
X
Referring to the first row of the matrix of table 3, the numeral on the left nearest to the added column E is 3, Lmax, and thus the value of the nearest numeral on the left is not increased. In addition, the number q of Xs on the right before the right-nearest numeral 3 is 0. Therefore, the value keeps its original value 3, and the value of the first row of the added column E keeps its original value 1. The same method is applied to the second through sixth row. Because N is 8, the number of added wavelengths is 2. The longest optical paths are formed by selecting any two nodes. In this case, a wavelength W 7 is used for forming an optical path (nodes A → E, nodes E → A), and a wavelength W 8 is used for forming an optical path (nodes C → G, nodes G → C). An optical fiber link in the opposite-direction is used for forming both optical paths between nodes B and F, and between nodes D and H, using wavelengths W 7 and W8.
II-2. The Wavelength Assignment Method when the Number of Nodes is an Even Number and Not a Multiple of 4
1. This method is the same as the method used for the case where the number of nodes is a multiple of 4, but the following difference exists in the procedure of assigning wavelengths to the longest optical paths (with the maximum distance) using the added wavelengths.
2. When wavelengths are assigned to the longest optical paths, an added wavelength is used for each four nodes and the other wavelength is used for the other two nodes. In this case, the used wavelength remains unused in the opposite-direction optical fiber link.
Illustratively, when this method is applied to a communication network having 6 nodes, the following table 4 is obtained. In table 4, a node D is added between nodes C and E.
TABLE 4
A
B
C
D
E
F
W1
1
2 → 2
X
1
2
X
W2
2
X
1 → 2
X
1
1
W3
X
1
2 → 1
2
X
2
W4
3
X
X
3
X
X
W5
X
X
3
X
X
3
Because the number of nodes is 6, four nodes are considered as one group, and two nodes are considered as the other group. In table 4, nodes A, B, C, D and E are considered as one group, and nodes C and F are considered as the other group. A wavelength W 4 is used in optical paths A → D, D → A, and optical paths E → B, B → E are formed through the opposite-direction optical fiber link. A wavelength W 5 is used in optical paths C → F, F → C, and the wavelength W 5 is not used in the opposite-direction optical fiber link.
As mentioned above, the conventional method of assigning wavelengths is simple, but provides only a static method. Of course, it is possible to change the configuration of the method such that the rows are exchanged in the matrix, or rotation of the column is performed with the nodes fixed, but this modified configuration is also inevitably limited to a specific form.
III. The Wavelength Assignment Method when the Number of Nodes is Increased
First, a wavelength assignment is performed according to the above-mentioned method so as to achieve full-mesh connectivity in a ring communication network with any number of nodes. Thereafter, when a node is added at any position, a communication network is configured to have full-mesh connectivity with a minimum number of wavelengths while minimizing the change of the already-existing communication network.
When the number of the nodes is increased from an odd number to an even number, the above-mentioned method is applied; it is found that even when the number of nodes is increased, a minimum number of wavelengths may be used. Before the increase of the number of nodes, the wavelength W 1 is used for forming an optical path from the node B to the node F. However, after the increase of the number of nodes, because the nodes are changed such as node B → node E, node E → node F, a modification is needed in the nodes B and F of the already-existing communication network. However, regarding the wavelength W 2 , the optical path from the node C to the node F is not changed even after the increase of the number of nodes. Accordingly, when the number of nodes is increased in such a method, it is necessary to change the corresponding nodes regarding the wavelengths W 1 , W 4 , and W 6 . When the number of nodes is increased from an even number to an odd number, the method for assigning wavelengths using a matrix is as follows.
1. A new column is added in a position where a node is added, and the number of rows is also increased by the number of wavelengths that is needed to be added due to the increase of the number of columns.
2. The already-used wavelengths are processed using the same method as applied to the already-used wavelengths in the case where the number of nodes is increased from an even number to an odd number.
3. Each column of a new row corresponding to the new wavelength is assigned a numeral, if any, not used in the same column, and if not, it is assigned “X”.
When this method is applied to a communication network where the number of nodes N is increased from 6 to 7, a matrix represented by the following table can be obtained. In this example, a node D is added between a node C and a node E.
TABLE 5
A
B
C
D
E
F
G
W1
1
1
2 → 3
X
X
2
X
W2
2
X
1 → 2
X
1
1
1
W3
X
2 → 3
X
X
2
X
2
W4
3 → 3
X
X
1
3
X
X
W5
X
X
3 → 1
3
X
X
3
W6
X
2
X
2
X
3
X
In table 5, when the number of nodes N is 7, the lower limit value of the number of wavelengths is 6, and therefore one row is added. In the row of wavelength W 1 , a numeral on the left nearest to the column D is 2, and therefore the nearest numeral is modified to 3. In the row of wavelength W 5 , the nearest numeral is 3, Lmax, and therefore it cannot be modified to 4. Instead, because the number of Xs that exist between the added column D and a numeral on the right nearest to the added column D is 2, its value is reduced to 1, and 3 is written in the new added column D of the row of W 5 . In addition, because one of each of the three numerals 1, 2, 3 must exist in each column to achieve full-mesh connectivity, each column of the row of the added wavelength W 6 is assigned a numeral if the numeral does not exist in the corresponding column, and is assigned “X” if all three numerals exist in the corresponding column. The matrix is completed by such a procedure. Here, it is found that it is necessary to modify the already-existing communication network with respect to wavelengths W 4 and W 5 .
For reference, the following tables 6 through 9 show the results of Ellinas' wavelength assignment in the case where the number of nodes is increased from 5 to 8. “<W>” shown in the following tables indicates that an optical path corresponding to a wavelength W is changed by the addition of a new node.
TABLE 6
Ellinas' wavelength assignment method when
the number of nodes is 5
A
B
F
G
H
W1
1
2
X
2
X
W2
2
X
1
1
1
W3
X
1
2
X
2
TABLE 7
Ellinas' wavelength assignment method
when the number of nodes is 6
(Node C is added between nodes B and F)
A
B
C
F
G
H
<W1>
1
1
2
X
2
X
<W2>
2
X
1
1
1
1
W3
X
2
X
2
X
2
W4
X
X
3
X
X
3
W5
3
X
X
3
X
X
TABLE 8
Ellinas' wavelength assignment method
when the number of nodes is 7
(Node D is added between nodes C and F)
A
B
C
D
F
G
H
W1
1
1
3
X
X
2
X
W2
2
X
2
X
1
1
1
W3
X
3
X
X
2
X
2
<W4>
X
X
1
3
X
X
3
<W5>
3
X
X
1
3
X
X
W6
X
2
X
2
X
3
X
TABLE 9
Ellinas' wavelength assignment method
when the number of nodes is 8
(Node E is added between nodes D and F)
A
B
C
D
E
F
G
H
<W1>
1
1
2
X
2
X
2
X
W2
2
X
3
X
X
1
1
1
<W3>
X
3
X
X
1
2
X
2
<W4>
X
X
1
1
3
X
X
3
W5
3
X
X
2
X
3
X
X
W6
X
2
X
3
X
X
3
X
W7
4
X
X
X
4
X
X
X
W8
X
X
4
X
X
X
4
X
As mentioned above, the conventional method of assigning wavelengths in a WDM ring communication network has an advantage in that an optical path between two respective nodes and a wavelength to be assigned to each optical path can be determined easily and systemically using a matrix. However, the conventional method has a problem that there is only provided a static type method of assigning wavelengths, thereby reducing flexibility in implementing a communication network.
Accordingly, there is a need in the art for an improved method of assigning wavelengths in a WDM ring communication network.
SUMMARY OF THE INVENTION
Therefore, the present invention has been made in view of the above problem, and it is an object of the present invention to provide a method of assigning wavelengths in a wavelength division multiplexing ring communication network wherein optical paths are set and wavelengths are assigned using a minimum number of wavelengths.
It is another object of the present invention to provide a method of assigning wavelengths in a wavelength division multiplexing ring communication network which allows forming of optical paths between each two nodes with a minimum number of wavelengths, while minimizing change of the configuration of the already-existing communication network when a node is added to the already-existing communication network.
In accordance with one aspect of the present invention, a method for assigning a predetermined wavelength between two different nodes in a wavelength division multiplexing ring communication network that has an N number of nodes and at least one pair of optical fibers sequentially connecting the N number of nodes is provided. The method includes the steps of:
forming a matrix that represents optical-path configuration and wavelength assignment for an N−1 number of nodes;
extending the matrix by adding a column at any position of the matrix and then assigning X to locations of the added column;
adding an N/2 number of rows in the matrix;
tracking along each row toward the left, from the added column, to find a firstly encountered numeral and increasing the found numeral by one;
assigning numerals 1, 2, . . . , N/2 sequentially to locations corresponding to the added column in the added rows, and assigning X to locations next to the numeral-assigned locations, the number of X-assigned locations being equal to a hop-number corresponding to the assigned numeral minus 1; and
tracking along each of the added rows toward the right to find an empty location and assign thereto a numeral not used in the same column as the empty location, among the numerals 1, 2, . . . , N/2, and assigning X to locations next to the empty location, the number of X-assigned locations being equal to a hop-number corresponding to the assigned numeral minus 1,
where N represents an even number and X representing that an optical path of the corresponding node is not formed.
In accordance with another aspect of the present invention, a method for assigning a predetermined wavelength between two different nodes, in a case where the number of nodes is increased, in a wavelength division multiplexing ring communication network that has an N number of nodes and at least one pair of optical fibers sequentially connecting the N number of nodes is provided. The method includes the steps of:
expressing, by a matrix, optical-path configuration and wavelength assignment of the network before extending the number of nodes;
extending the matrix by adding a column to extend the number of nodes at a corresponding position of the matrix and then assigning X to the added column;
tracking along each row toward the left, from the added column, to find a firstly encountered numeral and increasing the found numeral by one, and, if the numeral exceeds a maximum number of hops (Lmax=(N−1)/2)) after being increased, modifying the numeral to a hop-number from a column corresponding to the firstly-encountered numeral to the added column;
tracking along each row toward the right, from the added column, to find a firstly encountered numeral and assigning, to each row of the added column, a hop-number from the added column to a column corresponding to the firstly-encountered numeral; and
assigning X to an empty location of the added column,
where N represents an odd number and X representing that an optical path of the corresponding node is not formed.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram showing a conventional ring communication network including five nodes with full-mesh connectivity;
FIG. 2 is a block diagram illustrating a conventional method for assigning wavelengths in a ring communication network including four nodes;
FIG. 3 is a block diagram illustrating a conventional method for assigning wavelengths in a ring communication network including five nodes;
FIG. 4 is a diagram illustrating a method for assigning wavelengths in a ring communication network when the number of nodes is 8, according to an embodiment of the present invention; and
FIG. 5 is a diagram illustrating a method for assigning wavelengths in a ring communication network when the number of nodes is increased from 8 to 9, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will be described in detail with reference to FIGS. 4 and 5 . In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. For the purposes of clarity and simplicity, a detailed description of known functions and configurations incorporated herein will be omitted as it may make the subject matter of the present invention unclear.
A WDM-type wavelength assignment method according to the present invention is performed based on the following basic principle.
Basic Principle
1. Optical paths are formed as uniformly as possible using each wavelength.
2. Each wavelength should be assigned exactly once in the entire optical fiber link. This requirement is to improve the efficiency of utilizing wavelengths.
As mentioned in the description of the conventional wavelength assignment method, when the number of nodes is N, the entire number of optical paths to be formed is N(N−1). In addition, the minimum number of wavelengths needed to assign one optical path between each two nodes in a WDM ring communication network, is (N 2 −1)/8 in the case where N is an odd number, N 2 /8 in the case where N is an even number and a multiple of 4, and (N 2 +4)/8 in the case where N is an even number and not a multiple of 4.
The method of assigning wavelengths and setting optical paths according to one embodiment of the present invention classifies the WDM ring communication networks into three cases: (1) when the number of nodes is an even number, (2) when the number of the nodes is increased, and (3) for recovery from network-cut failures.
I. A Method of Assigning Wavelengths and Setting Optical Paths when the Number of Nodes is an Even Number
When the number of nodes N is an even number, a method is used such that after a wavelength assignment is performed for a communication network where the number of nodes is (N−1), that is, odd, the number of nodes is increased.
1. A matrix representing a wavelength assignment when the number of nodes is (N−1) is formed.
2. A node is added at any position to generate a new column in position corresponding to the added node, extending the number of nodes, and then “X” is written in each location of the added column.
3. N/2 rows are added.
4. Tracking to the left from the added column, a first encountered numeral for each row is selected. That is, a numeral on the left nearest to each row of the added column is selected, and the selected numeral is increased by 1.
5. Numerals 1, 2 . . . N/2 are written sequentially in the added rows of the added column. Accordingly, for each added row, a number of Xs equal to the number of hops corresponding to the written numeral minus 1 are written in positions next to the added column.
6. Shifting one by one to the right in each added row from the added column, a numeral of the numerals 1, 2, . . . N/2, unused in the corresponding column, is written in an empty position. Accordingly, for each added row, a number of Xs equal to the number of hops corresponding to the written numeral minus 1 are written in positions next to the added column.
Illustratively, when this method is applied to a communication network having 8 nodes, an optical-path setting matrix is obtained as shown in the following table 10. This is also schematically shown in FIG. 4 . In this example, a node E is added between nodes D and F.
TABLE 10
A
B
C
D
E
F
G
H
W1
1
3->4
X
X
X
3
X
X
W2
2
X
2 -> 3
X
X
1
2
X
W3
3
X
X
1 -> 2
X
2
X
1
W4
X
1
3 -> 4
X
X
X
3
X
W5
X
2
X
2 -> 3
X
X
1
2
W6
X
X
1
3 -> 4
X
X
X
3
W7
X
3
X
X
1
4
X
X
W8
X
X
2
X
2
X
4
X
W9
X
X
X
1
3
X
X
4
W10
4
X
X
X
4
X
X
X
1. A matrix representing a wavelength assignment when the number of nodes is (8-1) is formed.
2. A node E is added between nodes D and F to generate a new column in position corresponding to the added node, extending the number of nodes, and then “X” is written in each row of the added column.
3. 8/2 rows (W 7 , W 8 , W 9 , W 10 ) are added.
4. Tracking to the left from the added column, a first encountered numeral for each row is selected. That is, a numeral on the left nearest to each row of the added column is selected, and then the selected numeral is increased by 1. Regarding a wavelength W 1 , a numeral 3 is selected, and therefore its value is modified to 4.
5. Numerals 1, 2, 3 and 4 are sequentially placed in positions of the added rows W 7 , W 8 , W 9 , and W 10 , corresponding to the added column E, and, for each added row, a number of Xs equal to the number of hops corresponding to the newly placed numeral minus 1 are written in positions next to the added column.
6. Shifting one by one to the right in each added row from the added column, a numeral of 1, 2, . . . N/2, unused in the corresponding column, is written in an empty position. Accordingly, a number of Xs equal to the number of hops corresponding to the written numeral minus 1 are written in positions next to the added column.
II. A Method for Setting Optical Paths and Assigning Wavelengths when the Number of Nodes is Increased
The following description is provided for a method wherein, in a ring communication network with any number of nodes, after a WDM ring communication network with a minimum number of wavelengths is implemented and when a new node is added, a communication network is reconfigured with a minimum number of wavelengths.
II-1. When the Number of Nodes is Increased from an Odd Number to an Even Number
The above-mentioned method (I. Method of assigning wavelengths and setting optical paths when the number of nodes is an even number) is applied.
II-2. When the Number of Nodes is Increased from an Even Number to an Odd Number
1. A matrix is defined that represents a wavelength assignment for (N−1) number of nodes.
2. A node is added at any position to generate a new column in a position corresponding to the added node, extending the nodes, and then “X” is written in each row of the added column.
3. Tracking to the left from the added column, a first encountered numeral for each row is selected. That is, a numeral on the left nearest to each row of the added column is selected, and the selected numeral is increased by 1.
4. If the selected numeral is more than the maximum number of hops (Lmax=(N−1)/2) after being increased, the selected numeral is modified to a numeral corresponding to the number of hops up to the added column, and then the number of hops from the added column to a numeral on the right nearest to the added column is written in each corresponding row of the added column.
5. X is written in each empty place of the added column.
The following table 11 represents an optical-path setting matrix obtained by applying such a method to a communication network where the number of nodes N is increased from 8 to 9. This is also shown schematically in FIG. 5 . In this example, a node I is added between nodes E and F.
TABLE 11
A
B
C
D
E
I
F
G
H
W1
1
4->4
X
X
X
1
3
X
X
W2
2
X
3->4
X
X
X
1
2
X
W3
3
X
X
2->3
X
X
2
X
1
W4
X
1
4->3
X
X
2
X
3
X
W5
X
2
X
3->4
X
X
X
1
2
W6
X
X
1
4->2
X
3
X
X
3
W7
X
3
X
X
1->2
X
4
X
X
W8
X
X
2
X
2->3
X
X
4
X
W9
X
X
X
1
3->4
X
X
X
4
W10
4
X
X
X
4->1
4
X
X
X
For reference, the following tables 12 through 15 show the results of the wavelength assignment according to the above described embodiments of the present invention (referred to collectively as “ABC wavelength assignment method”) when the number of nodes is increased from 5 to 8.
TABLE 12
ABC wavelength assignment method
when the number of nodes is 5
A
B
F
G
H
W1
1
2
X
2
X
W2
2
X
1
1
1
W3
X
1
2
X
2
TABLE 13
ABC wavelength assignment method
when the number of nodes is 6
(Node C is added between nodes B and F)
A
B
C
F
G
H
W1
1
3
X
X
2
X
W2
3
X
X
1
1
1
W3
X
2
X
2
X
2
W4
2
X
1
3
X
X
W5
X
1
2
X
3
X
W6
X
X
3
X
X
3
TABLE 14
ABC wavelength assignment method
when the number of nodes is 7
(Node D is added between nodes C and F)
A
B
C
D
F
G
H
<W1>
1
2
X
2
X
2
X
<W2>
3
X
X
1
1
1
1
W3
X
3
X
X
2
X
2
W4
2
X
2
X
3
X
X
W5
X
1
3
X
X
3
X
<W6>
X
X
1
3
X
X
3
TABLE 15
ABC wavelength assignment method
when the number of nodes is 8
(Node E is added between nodes D and F)
A
B
C
D
E
F
G
H
W1
1
1
2
X
2
X
2
X
W2
2
X
3
X
X
1
1
1
W3
X
3
X
X
1
2
X
2
W4
X
X
1
1
3
X
X
3
W5
3
X
X
2
X
3
X
X
W6
X
2
X
3
X
X
3
X
W7
4
X
X
X
4
X
X
X
W8
X
X
4
X
X
X
4
X
III. The Number of Wavelengths Required for Recovery from Network-cut Failures
Optical communication networks typically handle a large quantity of data, and therefore there is a need to prepare a backup device and channel to swiftly recover from a network-cut failure generated in any link. In the following embodiment of the present invention, the number of backup wavelengths required for such a recovery from network-cut failures is equal to the number of wavelengths required when the longest paths (a path having the maximum number of hops) are excluded.
In more detail, referring to table 10 above, and assuming that a link from the node C to the node D is cut when the number of nodes is 8, a backup is required for each of wavelengths W 2 , W 3 , W 5 , W 6 , W 7 , and W 8 , except wavelengths W 1 , W 4 , W 9 , and W 10 that each include the maximum number of hops 4, and therefore six additional wavelengths are needed.
Meanwhile, in the above description, it is assumed that a network for forming the optical paths includes two optical fibers, on which optical signals travel in the clockwise and counterclockwise directions, respectively.
The above-described matrixes represented by tables 1 through 15 express an optical-path setting arrangement for a clockwise-direction optical fiber. An optical path in the counterclockwise direction can be considered as twinned with an optical path in the clockwise direction. That is, numerals in a row are rotated in the clockwise direction. For example, when an optical path is set in the clockwise direction as a node A → a node D, an optical path is set in the counterclockwise direction as the node D → the node A.
In more detail, referring to table 10, numerals in the first and third rows are written in the sequence 1 → 4 → 3 and 3 → 2 → 2 → 1, respectively. Therefore, the numerals are rotated in the clockwise direction to be replaced with numerals in the sequence 3 → 1 → 4 and 1 → 3 → 2 → 2.
As apparent from the above description, in the present invention, optical paths are set and wavelengths are assigned using a minimum number of wavelengths in a WDM ring communication network, thereby improving the transmission capacity in the network.
In addition, when any node is added to an already-existing ring network, inter-node optical paths can be formed using a minimum number of wavelengths, minimizing change in the configuration of the already-existing ring network.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. For example, the present invention is not applied only to a ring network composed of just two optical fibers, but also to any type of ring network.
Accordingly, the scope of the present invention should not be limited to the description of the preferred embodiment, but defined by the accompanying claims as well as equivalents thereof.
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A method for assigning a predetermined wavelength between two different nodes in a wavelength division multiplexing (WDM) ring communication network that has an N number of nodes and at least one pair of optical fibers sequentially connecting the N number of nodes is disclosed. A matrix is formed by an algorithm representing optical-path configuration and wavelength assignment for nodes representing three cases: (1) when the number of nodes is an even number; (2) when the number of nodes is increased; and (3) for recovery from network-cut failures.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application Ser. No. 12/421,379 filed Apr. 9, 2009. The entire contents of this application is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention pertains to the field of automatic transmissions for motor vehicles and, more particularly, to a friction element load sensor that directly measures torque transmitted by a friction element of an automatic transmission.
BACKGROUND OF THE INVENTION
A step-ratio automatic transmission system in a vehicle utilizes multiple friction elements for automatic gear ratio shifting. Broadly speaking, these friction elements may be described as torque establishing elements although more commonly they are referred to as clutches or brakes. The friction elements function to establish power flow paths from an internal combustion engine to vehicle traction wheels. During acceleration of the vehicle, the overall speed ratio, which is the ratio of a transmission input shaft speed to a transmission output shaft speed, is reduced during a ratio upshift as vehicle speed increases for a given engine throttle setting. A downshift to achieve a higher speed ratio occurs as an engine throttle setting increases for any given vehicle speed, or when the vehicle speed decreases as the engine throttle setting is decreased.
Various planetary gear configurations are found in modern automatic transmissions. However the basic principle of shift kinematics remains similar. Shifting a step-ratio automatic transmission having multiple planetary gearsets is accompanied by applying and/or releasing friction elements to change speed and torque relationships by altering the torque path through the planetary gearsets. Friction elements are usually actuated either hydraulically or mechanically.
In the case of a synchronous friction element-to-friction element upshift, a first pressure actuated torque establishing element, referred to as an off-going friction element, is released while a second pressure actuated torque establishing element, referred to as an on-coming friction element, engages in order to lower a transmission gear ratio. A typical upshift event is divided into preparatory, torque and inertia phases. During the preparatory phase, an on-coming friction element piston is stroked to prepare for its engagement while an off-going friction element torque-holding capacity is reduced as a step toward its release. During the torque phase, which may be referred to as a torque transfer phase, on-coming friction element torque is raised while the off-going friction element is still engaged. The output shaft torque of the automatic transmission typically drops during the torque phase, creating a so-called torque hole. When the on-coming friction element develops enough torque, the off-going friction element is released, marking the end of the torque phase and the beginning of the inertia phase. During the inertia phase, the on-coming friction element torque is adjusted to reduce its slip speed toward zero. When the on-coming friction element slip speed reaches zero, the shift event is completed.
In a synchronous shift, the timing of the off-going friction element release must be synchronized with the on-coming friction element torque level to deliver a consistent shift feel. A premature release leads to engine speed flare and a deeper torque hole, causing perceptible shift shock for a vehicle occupant. A delayed release causes a tie-up of gear elements, also resulting in a deep and wide torque hole for inconsistent shift feel. A conventional shift control relies on speed measurements of the powertrain components, such as an engine and a transmission input shaft, to control the off-going friction element release process during the torque phase. A conventional torque phase control method releases the off-going friction element from its locked state through an open-loop control based on a pre-calibrated timing, following a pre-determined off-going friction element actuator force profile. This conventional method does not ensure optimal off-going friction element release timing and therefore results in inconsistent shift feel.
Alternatively, a controller may utilize speed signals to gauge off-going friction element release timing. That is, the off-going friction element is released if the controller detects a sign of gear tie-up, which may be manifested as a measurable drop in input shaft speed. When a release of the off-going friction element is initiated prematurely before the on-coming friction element develops enough torque, engine speed or automatic transmission input shaft speed may rises rapidly in an uncontrolled manner. If this so-called engine speed flair is detected, the controller may increase off-going friction element control force to quickly bring down automatic transmission input speed or off-going friction element slip speed. This speed-based or slip-based approach often results in a hunting behavior between gear tie-up and engine flair, leading to inconsistent shift feel. Furthermore, off-going friction element slip control is extremely difficult because of its high sensitivity to slip conditions and a discontinuity between static and dynamic frictional forces. A failure to achieve a seamless slip control during the torque phase leads to undesirable shift shock.
In the case of a non-synchronous automatic transmission, the upshifting event involves engagement control of only an on-coming friction element, while a companion clutching component, typically a one-way coupling, automatically disengages to reduce the speed ratio. The non-synchronous upshift event can also be divided into three phases, which may also be referred to as a preparatory phase, a torque phase and an inertia phase. The preparatory phase for the non-synchronous upshift is a time period prior to the torque phase. The torque phase for the non-synchronous shift is a time period when the on-corning friction element torque is purposely raised for its engagement until the one-way coupling starts slipping or overrunning. This definition differs from that for the synchronous shift because the non-synchronous shift does not involve active control of a one-way coupling or the off-going friction element. The inertia phase for the non-synchronous upshift is a time period when the one-way coupling starts to slip, following the torque phase. According to a conventional upshift control, during the torque phase of the upshifting event for a non-synchronous automatic transmission, the torque transmitted through the oncoming friction element increases as it begins to engage. A kinematic structure of a non-synchronous upshift automatic transmission is designed in such a way that torque transmitted through the one-way coupling automatically decreases in response to increasing oncoming friction element torque. As a result of this interaction, the automatic transmission output shaft torque drops during the torque phase, which again creates a so-called “torque hole.” Before the one-way coupling disengages, as in the case previously described, a large torque hole can be perceived by a vehicle occupant as an unpleasant shift shock. An example of a prior art shift control arrangement can be found in U.S. Pat. No. 7,351,183 hereby incorporated by reference.
A transmission schematically illustrated at 2 in FIG. 1 is an example of a prior art multiple-ratio transmission with a controller 4 wherein ratio changes are controlled by friction elements acting on individual gear elements. Engine torque from vehicle engine 5 is distributed to torque input element 10 of hydrokinetic torque converter 12 . An impeller 14 of torque converter 12 develops turbine torque on a turbine 16 in a known fashion. Turbine torque is distributed to a turbine shaft, which is also transmission input shaft 18 . Transmission 2 of FIG. 1 includes a simple planetary gearset 20 and a compound planetary gearset 21 . Gearset 20 has a permanently fixed sun gear S 1 , a ring gear R 1 and planetary pinions P 1 rotatably supported on a carrier 22 . Transmission input shaft 18 is drivably connected to ring gear R 1 . Compound planetary gearset 21 , sometimes referred to as a Ravagineaux gearset, has a small pitch diameter sun gear S 3 , a torque output ring gear R 3 , a large pitch diameter sun gear S 2 and compound planetary pinions. The compound planetary pinions include long pinions P 2 / 3 , which drivably engage short planetary pinions P 3 and torque output ring gear R 3 . Long planetary pinions P 2 / 3 also drivably engage short planetary pinions P 3 . Short planetary pinions P 3 further engage sun gear S 3 . Planetary pinions P 2 / 3 , P 3 of gearset 21 are rotatably supported on compound carrier 23 . Ring gear R 3 is drivably connected to a torque output shaft 24 , which is drivably connected to vehicle traction wheels through a differential and axle assembly (not shown). Gearset 20 is an underdrive ratio gearset arranged in series with respect to compound gearset 21 . Typically, transmission 2 preferably includes a lockup or torque converter bypass clutch, as shown at 25 , to directly connect transmission input shaft 18 to engine 5 after a torque converter torque multiplication mode is completed and a hydrokinetic coupling mode begins. FIG. 2 is a chart showing a clutch and brake friction element engagement and release pattern for establishing each of six forward driving ratios and a single reverse ratio for transmission 2 .
During operation in the first four forward driving ratios, carrier P 1 is drivably connected to sun gear S 3 through shaft 26 and forward friction element A. During operation in the third ratio, fifth ratio and reverse, direct friction element B drivably connects carrier 22 to shaft 27 , which is connected to large pitch diameter sun gear S 2 . During operation in the fourth, fifth and sixth forward driving ratios, overdrive friction element B connects turbine shaft 18 to compound carrier 23 through shaft 28 . Friction element C acts as a reaction brake for sun gear S 2 during operation in second and sixth forward driving ratios. During operation of the third forward driving ratio, direct friction element B is applied together with forward friction element A. The elements of gearset 21 then are locked together to effect a direct driving connection between shaft 28 and output shaft 26 . The torque output side of forward friction element A is connected through torque transfer element 29 to the torque input side of direct friction element B, during forward drive. The torque output side of direct friction element B, during forward drive, is connected to shaft 27 through torque transfer element 30 . Reverse drive is established by applying low-and-reverse brake D and friction element B.
For the purpose of illustrating one example of a synchronous ratio upshift for the transmission of FIG. 1 , it will be assumed that an upshift will occur between the first ratio and the second ratio. On such a 1-2 upshift, friction element C starts in the released position before the shift and is engaged during the shift while low/reverse friction element D starts in the engaged position before the shift and is released during the shift. Forward friction element A stays engaged while friction element B and overdrive friction element E stay disengaged throughout the shift. More details of this type of transmission arrangement are found in U.S. Pat. No. 7,216,025, which is hereby incorporated by reference.
FIG. 3 depicts a general process of a synchronous friction element-to-friction element upshift event from a low gear configuration to a high gear configuration for the automatic transmission system of FIG. 1 . For example, the process has been described in relation to a 1-2 synchronous ratio upshift above wherein friction element C is an oncoming friction element and low/reverse friction element D is an off-going friction element, but it is not intended to illustrate a specific control scheme.
The shift event is divided into three phases: a preparatory phase 31 , a torque phase 32 and an inertia phase 33 . During preparatory phase 31 , an on-coming friction element piston is stroked (not shown) to prepare for its engagement. At the same time, off-going friction element control force is reduced as shown at 34 as a step toward its release. In this example, off-going friction element D still retains enough torque capacity shown at 35 to keep it from slipping, maintaining transmission 2 in the low gear configuration. However, increasing on-coming friction element control force shown at 36 reduces net torque flow within gearset 21 . Thus, the output shaft torque drops significantly during torque phase 32 , creating a so-called torque hole 37 . A large torque hole can be perceived by a vehicle occupant as an unpleasant shift shock. Toward the end of torque phase 32 , off-going friction element control force is dropped to zero as shown at 38 while on-coming friction element apply force continues to rise as shown at 39 . Torque phase 32 ends and inertia phase 33 begins when off-going friction element D starts slipping as shown at 40 . During inertia phase 33 , off-going friction element slip speed rises as shown at 41 while on-coming friction element slip speed decreases as shown at 42 toward zero at 43 . The engine speed and transmission input speed 44 drops as the planetary gear configuration changes. During inertia phase 33 , output shaft torque indicated by profile 45 is primarily affected by on-coming friction element C torque capacity indirectly indicated by force profile 46 . When on-coming friction element C completes engagement or when its slip speed becomes zero at 43 , inertia phase 33 ends, completing the shift event.
FIG. 4 shows a general process of a synchronous friction element-to-friction element upshift event from the low gear configuration to the high gear configuration in which off-going friction element D is released prematurely as shown at 51 compared with the case shown in FIG. 3 . When off-going friction element 1 ) is released, it breaks a path between automatic transmission input shaft 18 and automatic transmission output shaft 24 , depicted in FIG. 1 , no longer transmitting torque to automatic transmission output shaft at the low gear ratio. Since on-coming friction element C is yet to carry enough engagement torque as indicated by a low apply force at 52 , automatic transmission output shaft torque drops largely, creating a deep torque hole 53 which can be felt as a shift shock. At the same time, engine speed or transmission input speed rapidly increases as shown at 54 , causing a condition commonly referred to as engine flare. A large level of engine flare can be audible to a vehicle occupant as unpleasant noise. Once on-coming friction element C develops sufficient engagement torque as indicated by a rising control force at 55 , automatic transmission input speed comes down and the output torque rapidly moves to a level at 56 that corresponds to on-coming friction element control force 55 . Under certain conditions, this may lead to a torque oscillation 57 that can be perceptible to a vehicle occupant as unpleasant shift shock. FIG. 5 shows a general process of a friction element-to-friction element upshift event from the low gear configuration to the high gear configuration in which off-going friction element release is delayed as shown at 61 compared with the case shown in FIG. 3 . Off-going friction element D remains engaged even after on-coming friction element C develops a large amount of torque as indicated by a large actual control force at 65 . Thus, transmission input torque continues to be primarily transmitted to output shaft 24 at the low gear ratio. However, large on-coming friction element control force 65 results in a drag torque, lowering automatic transmission output shaft torque, creating a deep and wide torque hole 63 . This condition is commonly referred to as a tie-up of gear elements. A severe tie-up can be felt as a shift shock or loss of power by a vehicle occupant.
As illustrated in FIGS. 3 , 4 , and 5 a missed synchronization of off-going friction element release timing with respect to on-coming friction element torque capacity leads to engine flare or tie-up. Both conditions lead to varying torque levels and profiles at automatic transmission torque output shaft 24 during shifting. If these conditions are severe, they result in undesirable driving experience such as inconsistent shift feel or perceptible shift shock. The prior art methodology attempts to mitigate the level of missed-synchronization by use of an open loop off-going friction element release control based on speed signal measurements. It also attempts to achieve a consistent on-coming friction element engagement torque by an open-loop approach during a torque phase under dynamically-changing shift conditions.
FIG. 6 illustrates a prior art methodology for controlling a friction element-to-friction element upshift from a low gear configuration to a high gear configuration for automatic transmission 2 in FIG. 1 . The prior art on-coming control depicted in FIG. 6 applies to a conventional torque phase control utilized for either a synchronous or non-synchronous shift. In this example off-going friction element D remains engaged until the end of torque phase 32 . Although the focus is placed on torque phase control, FIG. 6 depicts the entire shift control process. As shown the shift event is divided into three phases: a preparatory phase 31 , a torque phase 32 and an inertia phase 33 . During preparatory phase 31 , an on-coming friction element piston is stroked (not shown) to prepare for its engagement. At the same time, off-going friction element control force is reduced as shown at 34 as a step toward its release. During torque phase 32 controller 4 commands an on-coming friction element actuator to follow a prescribed on-coming friction element control force profile 64 through an open-loop based approach. Actual on-coming friction element control force 65 may differ from prescribed profile 64 due to control system variability. Even if actual control force 65 closely follows prescribed profile 64 , on-coming friction element engagement torque may still vary largely from is shift to shift due to the sensitivity of the on-coming friction element engagement process to engagement conditions such as lubrication oil flow and friction surface temperature. Controller 4 commands enough off-going element control force 61 to keep off-going element D from slipping, maintaining the planetary gearset in the low gear configuration until the end of torque phase 32 . Increasing on-coming friction element control force 65 or engagement torque reduces net torque flow within the low-gear configuration. Thus, output shaft torque 66 drops significantly during torque phase 32 , creating so-called torque hole 63 . If the variability in on-coming friction element engagement torque significantly alters a shape and depth of torque hole 63 , a vehicle occupant may experience inconsistent shift feel. Controller 4 reduces off-going friction element actuator force at 38 , following a pre-calibrated profile, in order to release it at a pre-determined timing 67 . The release timing may be based on a commanded value of on-coming friction element control force 62 . Alternatively, off-going friction element D is released if controller 4 detects a sign of significant gear tie-up, which may be manifested as a detectable drop in input shaft speed 44 . Inertia phase 33 begins when off-going friction element D is released and starts slipping as shown at 67 . During inertia phase 33 , off-going friction element slip speed rises as shown at 68 while on-coming friction element slip speed decreases toward zero as shown at 69 . Transmission input speed 44 drops as the planetary gear configuration changes. During inertia phase 33 , output shaft torque 66 is primarily affected by on-coming friction element torque capacity or control force 65 . The shift event completes when the on-coming friction element comes into a locked or engaged position with no slip as shown at 70 .
FIG. 7 illustrates another prior art methodology for controlling torque phase 32 of a synchronous upshift process from the low gear configuration to the high gear configuration. In this example, controller 4 allows off-going friction element D to slip during torque phase 32 . Although the focus is placed on torque phase control, FIG. 7 depicts the entire shift event. During preparatory phase 31 , an on-coming friction element piston is stroked to prepare for its engagement. At the same time, off-going friction element control force 86 is reduced as a step toward its slip. During torque phase 32 , on-coming friction element control force is raised in a controlled manner. More specifically, controller 4 commands on-coming friction element actuator to follow a prescribed on-coming friction element control force profile 87 through an open-loop based approach. An actual on-coming friction element control force 88 may differ from the commanded profile 87 due to control system variability. Even if actual control force 88 closely follows commanded profile 87 , on-coming friction element engagement torque may still vary largely from shift to shift due to the sensitivity of on-coming friction element engagement process to engagement conditions such as lubrication oil flow and friction surface temperature. Increasing on-coming friction element control force 88 or on-coming friction element engagement torque reduces net torque flow within the low-gear configuration. This contributes to output shaft torque 99 being reduced during torque phase 32 , creating a so-called torque hole 85 .
If the variability in on-corning friction element engagement torque significantly alters the shape and depth of torque hole 85 , the vehicle occupant may experience inconsistent shift feel. A deep torque hole may be perceived as an unpleasant shift shock. During torque phase 32 , off-going friction element control force is reduced as shown at 82 to induce an incipient slip 83 . Controller 4 attempts to maintain off-going friction element slip at a target level through a closed-loop control based on off-going friction element speed 96 which may be directly measured or indirectly derived from speed measurements at pre-determined locations. A variability in off-going friction element control force 82 of off-going element slip torque may alter the shape and depth of torque hole 85 , thus affecting shift feel. If controller 4 inadvertently allows a sudden increase in off-going friction element slip level, automatic transmission input speed or engine speed 90 may surge momentarily, causing the so-called engine speed flair or engine flair. The engine flair may be perceived by a vehicle occupant as an unpleasant sound.
Controller 4 initiates off-going friction element release process at a predetermined timing shown at which may be based on a commanded value of on-corning friction element control force 93 . Controller 4 lowers off-going friction element control force, following a pre-calibrated profile 94 . If a release of off-going friction element D is initiated prematurely before on-coming friction element C develops enough torque, engine speed or input shaft speed may rise rapidly in an uncontrolled manner. If this engine speed flair 90 is detected, controller 4 increases off-going friction element control force to delay off-going friction element release process. Alternatively to the pre-determined off-going friction element release timing, controller 4 may utilize speed signals to determine a final off-going friction element release timing. When a sign of significant gear tie-up, which may be manifested as a measurable drop in input shaft speed, is detected, off-going friction element D is released following a pre-calibrated force profile. Inertia phase 33 begins when off-going friction element torque capacity or control force drops to non-significant level 95 . During inertia phase 33 , off-going friction element slip speed rises 96 while on-coming friction element slip speed decreases 97 toward zero. The transmission input shaft speed drops as shown at 98 as the planetary gear configuration changes. During inertia phase 33 , the output shaft torque 99 is primarily affected by on-coming friction element torque capacity, which is indicated by its control force 100 . When on-coming friction element C becomes securely engaged at 101 , the shift event completes.
In summary, a prior art methodology, which is based on an open-loop on-coming friction element control during a torque phase, cannot account for control system variability and dynamically-changing shift conditions during the torque phase, resulting in inconsistent shift feel or unpleasant shift shock. A pre-determined off-going friction element release timing with a pre-calibrated control force profile cannot ensure an optimal timing under dynamically changing shift conditions, resulting in inconsistent shift feel or unpleasant shift shock. The alternative approach to gauge off-going friction element release timing based on speed signals often results in a hunting behavior between gear tie-up and engine flair, leading to inconsistent shift feel. Furthermore, off-going friction element slip control is extremely difficult because of its high sensitivity to slip conditions. In addition, a large discontinuity exists between static and dynamic friction coefficients, introducing a large torque disturbance during an incipient slip control. A failure to achieve a seamless off-going friction element slip control during the torque phase leads to undesirable shift shock.
As can be seen from the above discussion the controllability of both off-going friction element and on-coming friction element is desirable in order to deliver a consistent and seamless shift quality. The prior art does not have a cost effective design solution to the problem of directly measuring torque passing through either a multiple disc clutch or a band brake and therefore is a need in the art for a transmission control system that minimizes shift shock during a gear ratio change that does not rely solely on traditional speed signal measurement or a predetermined open-loop control and instead relies on measuring friction element load level in either a multiple plate clutch or a band brake for consistently controlling its torque level through a closed loop approach.
SUMMARY OF THE INVENTION
The present invention is directed to a load sensor assembly for measuring an amount of torque transmitted through a torque establishing element of an automatic transmission. The assembly comprises a core mounted on a transmission housing and a load sensor mounted on the core and positioned against a portion of the torque establishing element whereby a portion of the amount of torque transmitted through the torque establishing element travels through the load sensor and is measured by the load sensor assembly. Preferably, a cable is connected to the load sensor for transmitting a signal representative of the amount of torque to a transmission controller. A cover or sleeve extends over the core and the sensor.
In a preferred embodiment, the torque establishing element is a multiple disk friction element including an end plate and a spline connection between the transmission case and the end plate. The connection has teeth that extend from the transmission case and cooperate with teeth extending from the end plate. The load sensor assembly is mounted on the transmission housing between two spline teeth extending from the end plate and in a location where a spline tooth would normally be located. Preferably, the core is made of metal and the sleeve is made from one of rubber, plastic and metal. The sensor may have several different configurations. In one configuration, a pin is fixed to the end plate and the load sensor is placed against the pin. In another configuration, the force sensor is a load-resistive elastomer deposited on a thin film and the core is a tooth of a friction element plate. An example of such a thin film force sensor can be found in U.S. Pat. No. 6,272,936, which is incorporated herein by reference. In yet another configuration, the core is a metal beam securely anchored to the transmission case and the load sensor is a strain sensor that measures an amount of strain on the beam caused by the torque.
In another embodiment the torque establishing element is a band brake including an anchor bracket and a band brake strap. The core may engage the strap in many ways. In one configuration, the band brake strap has a block extending therefrom and the core passes through the transmission housing and engages the block. The load sensor is located between the core and the block. In another configuration, the band brake strap has a hook extending therefrom formed by punching a hole in the strap. The core passes through the transmission housing and engages the hook and the load sensor is located between the core and the hook. In yet another configuration, the anchor bracket has a pin extending therefrom. The core passes through the transmission housing and engages the pin. The load sensor is located between the core and the pin. Preferably, a cushion is located between the load sensor and the cover.
In yet another embodiment, the torque establishing element is a band brake including an anchor bracket and a hand brake strap while the core is an anchor pin, which does not necessarily have a cover, mounted in the transmission case. The anchor pin extends out of the transmission case and engages the anchor bracket. The load sensor is mounted between the anchor pin and the transmission case whereby torque is transferred to the band strap, pushes on the anchor pin and is sensed by the load sensor. Preferably, a cushion is located between the load sensor and the anchor pin. The core includes an anchor pin mounted in the transmission case. The core extends out of the transmission case and is connected to an anchor strut which, in turn, engages the anchor bracket. The load sensor is mounted between the anchor pin and the transmission case. Torque is transferred to the band strap where it pushes on both the anchor strut and pin, with the torque being sensed by the load sensor. Preferably, the transmission housing includes a hole for supporting the anchor pin. A nut is mounted in one end of the hole and secures the anchor pin to the housing. A plug and a support are located between the nut and the anchor pin. With this arrangement, torque passing through the friction elements of a transmission may be directly measured and shift shock and engine flair may be reduced.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings, wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a gearing arrangement for an automatic transmission system according to the prior art;
FIG. 2 is a chart showing a clutch and brake friction element engagement and release pattern for establishing each of six forward driving ratios and a single reverse ratio for the transmission schematically illustrated in FIG. 1 ;
FIG. 3 is a plot of a general process of a synchronous friction element-to-friction element upshift event from a low gear configuration to a high gear configuration for the prior art automatic transmission system of FIG. 1 ;
FIG. 4 is a plot of the general process of a synchronous friction element-to-friction element upshift event from the low gear configuration to the high gear configuration in which the off-going friction element is released prematurely compared with the case shown in FIG. 3 ;
FIG. 5 is a plot of the general process of a synchronous friction element-to-friction element upshift event from the low gear configuration to the high gear configuration in which off-going friction element release is delayed compared with the case shown in FIG. 3 ;
FIG. 6 is plot of a prior art synchronous friction element-to-friction element upshift control from a low gear configuration to a high gear configuration based on speed measurements of powertrain components for the automatic transmission system in FIG. 1 wherein an off-going friction element remains locked during the torque phase;
FIG. 7 is plot of a prior art synchronous friction element-to-friction element upshift control from a low gear configuration to a high gear configuration based on speed measurements of powertrain components for the automatic transmission system in FIG. 1 , wherein an off-going friction element is slipped during the torque phase;
FIG. 8 is a schematic diagram of a gearing arrangement for an automatic transmission system including load sensor locations in accordance with a first preferred embodiment of the invention;
FIG. 9 is a plot of a synchronous friction element to friction element upshift control from a low gear configuration to a high gear configuration for the automatic control system in FIG. 8 based on direct measurements or estimates of torsional load exerted onto an off-going friction element in accordance with a preferred embodiment of the invention;
FIG. 10 is a flow chart showing an on-coming friction element control method in accordance with a preferred embodiment of the invention;
FIG. 11 is a flow chart showing an off-going element release control method in accordance with a preferred embodiment of the invention;
FIG. 12 is a plot of the process used to determine an ideal release timing of the off-going friction element in accordance with first preferred embodiment of the invention;
FIG. 13 is a flow chart showing a shift control method in accordance with a preferred embodiment of the invention;
FIG. 14 is a plot of a synchronous friction element-to-friction element upshift from a low gear configuration to a high gear configuration for the automatic transmission control system in FIG. 8 based on the direct measurements or estimates of torsional load exerted onto an off-going friction element and an on-coming element in accordance with another preferred embodiment of the invention;
FIG. 15 is a flow chart showing an on-coming friction element shift control method in accordance with another preferred embodiment of the invention;
FIG. 16A depicts a load sensor assembly in accordance with another preferred embodiment of the invention installed between two teeth of a endplate of a friction element for measuring a relative load level on the friction element;
FIG. 16B depicts the load sensor assembly of FIG. 16A installed in a transmission case;
FIG. 17A depicts a load sensor assembly in accordance with another preferred embodiment of the invention placed against a pin extending from an endplate of a friction element for measuring a relative load level on the off-going friction element;
FIG. 17B depicts the load sensor assembly of FIG. 17A installed in a transmission case;
FIG. 18 depicts a load sensor in accordance with another preferred embodiment of the invention formed of a thin film-type load sensor and attached to a tooth for measuring a relative load level on the off-going friction element;
FIG. 19 depicts a load sensor assembly in accordance with another preferred embodiment of the invention formed of a metal beam for measuring a relative load level on the off-going friction element;
FIG. 20 depicts a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element;
FIGS. 21A-21C depict a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element;
FIGS. 22A and 22B depict a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element;
FIG. 23 depicts a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element;
FIG. 24 depicts a chart in accordance with another preferred embodiment of the invention;
FIG. 25 depicts a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element;
FIG. 26 depicts a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element;
FIG. 27 depicts a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element;
FIG. 28 depicts a load sensor assembly in accordance with another preferred embodiment of the invention installed on a band brake type friction element for measuring a relative load level on the friction element; and
FIG. 29 depicts a chart in accordance with another preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With initial reference to FIG. 8 , there is shown an automotive transmission employing the invention. As this automatic transmission arrangement is similar to the one schematically illustrated in FIG. 1 all the same parts have been indicated with corresponding reference numbers and therefore a duplicate discussion of these parts will not be made here. Instead, of particular importance is the addition of a torque sensor 120 located in friction element C, a load sensor 130 located in friction element D, and a torque sensor 131 located in transmission output shaft 24 , all connected to controller 4 for controlling various functions of transmission 2 as will be more fully discussed below.
FIG. 9 shows a torque phase control method according to a preferred embodiment of the invention for a synchronous friction element-to-friction element upshift from a low gear configuration to a high gear configuration for the automatic transmission system in FIG. 8 . The on-coming friction element control method illustrated here is also applicable to non-synchronous shift control. The shift event is divided into 3 phases: preparatory phase 31 , torque phase 32 and inertia phase 33 . During preparatory phase 31 , an on-coming friction element piston is stroked to prepare for its engagement. At the same time, off-going friction element control force or its torque capacity is reduced as shown at 404 as a step toward its release. During torque phase 32 , on-coming friction element control force is raised in a controlled manner as shown at 405 . More specifically, controller 4 commands on-coming friction element actuator to follow a target on-coming friction element engagement torque profile 406 through a closed-loop control directly based on the measurements of on-coming friction element engagement torque 407 during torque phase 32 . On-coming friction element torque 407 may be directly measured using a load sensor according to this invention as more fully described below. On-coming friction element engagement torque directly affects transmission output torque that is transmitted to the vehicle wheels. This torque-based close-loop control eliminates or significantly reduces the undesirable effects of on-coming friction element engagement torque sensitivity to hardware variability and shift conditions, achieving a consistent shift feel, regardless of shift conditions.
Alternatively to the direct measurements, on-coming friction element torque can be determined from the measurements of transmission output shaft torque using torque sensor 131 depicted in FIG. 8 . Mathematically, on-coming friction element torque T OCE can be described as a function of measured output shaft torque T OS as:
T OCE ( t )= G OCE T OS ( t ) Eq. (1)
Where G OCE can be readily obtained based on a given gear set geometry.
Yet alternatively, on-coming friction element torque T OCE can be estimated through the following Eq. (2), based on a slight change in transmission component speeds ω i at pre-determined locations (i=1, 2, . . . , n),
T OCE ( t )= F trans (ω i ,t ) Eq. (2)
where t indicates time and F trans represents a mathematical description of a transmission system. More specifically, as on-coming friction element engagement torque rises 407 , torque levels transmitted through various transmission components change. This creates small, but detectable changes in ω i . A transmission model, F trans , can be readily derived to estimate on-coming friction element engagement torque when off-going friction element remains locked during torque phase 32 .
Controller 4 commands enough off-going friction element control force 408 to keep it from slipping, maintaining the planetary gearset in the low gear configuration during torque phase 32 . As on-coming friction element engagement torque 407 increases, a reaction torque goes against a component that is grounded to a transmission case. More specifically, in this case, torque transmitted through off-going friction element or torsional load 409 exerted onto off-going friction element D decreases proportionally. Off-going friction element load level 409 can be directly monitored using a torque sensor such as is more fully discussed below. Alternatively, off-going friction element load level T OGE 409 can be calculated from measured or estimated on-coming friction element engagement torque T OCE 407 when off-going friction element remains locked during torque phase 32 according to:
T OGE ( t )= F OCE/OGE ( T OCE ( t )) Eq. (3)
where F OCE/OGE represents a torque ratio between on-corning friction element C and off-going friction element D at the low gear configuration and can be obtained based on gear set geometry. According to this invention, off-going friction element D is released at an ideal timing when torque load exerted onto off-going friction element D becomes zero or a near-zero level. Transmission controller 4 initiates a release process of off-going friction element D as shown at 410 as off-going friction element load 409 approaches zero at 411 . Off-going friction element torque is dropped quickly as shown at 412 with no slip control. Since no off-going friction element slip control is involved, the method is insensitive to off-going friction element break-away friction coefficient variability. In addition, the quick release of off-going friction element D shown at 412 induces little disruption in output shaft torque at 413 because off-going friction element load level is near zero as shown at 411 at the moment of release. Off-going friction element D starts slipping 411 once its control force reaches a non-significant level. During inertia phase 33 , a conventional control approach may be utilized based on on-coming friction element slip measurements. Off-going friction element slip speed increases as shown at 415 while on-coming friction element slip speed decreases as shown at 416 . The transmission input speed drops as shown at 417 as the planetary gear configuration changes. During inertia phase 33 , output shaft torque 418 is primarily affected by on-coming friction element torque level 419 . Alternatively to the conventional control, a closed loop control that is based on measured or estimated on-corning friction element torque may continue to be employed. When on-coming friction element C completes engagement or when its slip speed becomes zero as shown at 420 , the shift event completes.
FIG. 10 shows a flow chart of closed-loop on-coming friction element engagement torque control during the torque phase depicted in FIG. 9 . Step 430 is the beginning of torque phase 32 . Controller 4 chooses a desired on-coming element torque at step 431 and measures or estimates an actual torque at step 432 . At step 433 , the on-coming friction element actuator is then adjusted by controller 4 based on the difference between the measured/estimated torque level and the actual torque level. At step 434 , controller 4 determines if torque phase has ended and if so controller 4 starts inertia phase 33 at 436 .
FIG. 11 shows a flow chart of an off-going friction element torque control process during torque phase 32 depicted in FIG. 9 . The process starts at step 440 at the beginning of torque phase 32 . A load transmitted through locked off-going friction element D is directly measured or estimated at step 441 . At step 442 , when its load level drops below a predetermined level, off-going friction element D is promptly released at step 444 . The control process ends at step 445 at the end of torque phase 32 .
Alternatively to the measurements or estimates of absolute load levels, FIG. 12 illustrates the process to determine the ideal release timing of off-going friction element D based on relative load measurements or estimates according to this invention. FIG. 12 depicts an actual load profile 451 exerted on off-going friction element D and a relative load profile L(t) 452 measured by torque sensor 130 during the upshift event in FIG. 9 . The preferred embodiment requires only relative load profile L(t) 452 . Relative load profile L(t) 452 is preferably constructed from uncalibrated sensor output that reflects actual load profile 451 , but not its absolute levels. This feature eliminates the need of a full sensor calibration across the entire load range. It also makes the preferred embodiment insensitive to sensor output drift over time. However, the preferred embodiment relies on knowledge of sensor measurement L 0 453 which corresponds to zero off-going friction element load level 454 . Sensor measurement L 0 453 can be readily identified, as often as required, by sampling sensor output while vehicle transmission 2 is in a neutral or a similar condition where no load is exerted onto off-going friction element D. Transmission controller 4 collects relative load data 455 during torque phase 32 to dynamically construct relative load profile L(t) 452 . Then, controller 4 extrapolates L(t) to predict t 0 457 where L(t 0 )=L 0 . Once t 0 457 is obtained in advance, controller 4 predicts when to initiate an off-going friction element release process. Specifically controller 4 starts the release process at a time equal to t 0 −Δt shown at 458 , where Δt is the time required to quickly drop off-going friction element control force to zero. In this way, off-going friction element D starts slipping at or near ideal timing t 0 457 when the actual off-going friction element load level is at or close to zero as shown by reference numeral 454 .
FIG. 13 presents a flow chart of the new upshift control method according to this invention. During preparatory phase 31 at step 461 of a synchronous upshift event, off-going friction element torque capacity or apply force is reduced to a holding level without allowing any slip at step 462 while on-coming friction element piston is stroked at step 463 . During torque phase 32 , transmission controller 4 measures at step 465 a relative load level exerted onto off-going friction element D at a pre-specified sampling frequency using torque sensor 130 described further below. Controller 4 repeats this measurement step 465 until enough data points are collected at step 466 for dynamically constructing a relative load profile at step 467 that shows load as a function of time L(t). Once relative load profile L(t) is obtained, controller 4 predicts the ideal off-going friction element release timing t 0 at step 468 so that L(t 0 )=L 0 where L 0 corresponds to a substantially zero load level on off-going friction element D. Controller 4 initiates an off-going friction element release process at t 0 −Δt as shown as step 469 where Δt is a pre-specified time required to quickly drop off-going friction element apply force to zero. Alternatively, controller 4 may initiate the off-going friction element release process at t thres such that L(t thres )=L thres where L thres is a predetermined threshold. No slip control is required for off-going friction element D during torque phase 32 . Inertia phase 33 starts when off-going friction element D is released. The control methodology illustrated in FIG. 10 is preferably applied to on-coming friction element C during torque phase 32 . A conventional on-coming friction element control may be applied during inertia phase 33 based on speed signals. When on-coming friction element C becomes securely engaged at step 473 , the shift event completes at step 474 .
FIG. 14 illustrates another preferred embodiment of the invention relating to a transmission system with an on-coming friction element actuator which may not have a sufficient control bandwidth compared with a sampling time of load measurements. At the beginning of torque phase 32 , a transmission controller raises on-coming friction element actuator force based on a pre-calibrated slope 480 over a time interval Δt between t 0 and t 1 as shown at interval 481 . During interval 481 , on-coming friction element load is either measured or estimated with a sampling time finer than Δt to construct an engagement torque profile 482 . If the measured or estimated torque profile 482 indicates a slow rise compared with a target torque profile 483 , controller 4 increases a slope of commanded on-coming friction element control force for a next interval 485 between t 1 and t 2 . On the other hand, if the actual torque is rising faster than a target profile, controller 4 reduces a slope of commanded on-coming friction element control force. For example, during interval 485 between t 1 and t 2 , on-coming friction element load is either measured or estimated with a sampling time finer than Δt to construct an engagement torque profile 486 . The measured or estimated slope 486 of the engagement torque is compared against a target profile 487 to determine a slope 488 of commanded force profile for the following control interval. This process is repeated until the end of torque phase 32 . The off-going friction element release control remains the same as that shown in FIG. 9 .
FIG. 15 shows a flow chart of alternative closed-loop on-coming friction element engagement torque control during torque phase depicted in FIG. 14 . The start of torque phase 32 is shown at step 520 . Following path 521 , the off-coming friction element torque is measured or estimated at step 522 and torque profile 482 is created therefrom at step 523 . The method may have to go through several iterations as shown by decision block 524 and return loop 525 . Torque slope profile 486 or an average derivative of torque profile 482 is calculated at 526 and while a desired target slope profile 487 is calculated at 527 and compared with torque slope profile 486 at 528 . The actuator force slope is increased 529 or decreased 530 and the process continues 531 , 532 until the end of torque phase 32 . The process then proceeds to inertia phase 33 at 533 .
While the shift control has been discussed above, attention is now directed to the structure of the various load sensor assemblies. FIG. 16A , 16 B, 17 A, 17 B, 18 and 19 depict several preferred embodiments of load sensor assemblies for measuring a relative load level exerted on off-going friction element D or on-coming element C according to preferred embodiments of the invention. FIG. 16A shows a cross-sectional view of a load sensor assembly 601 design according to a preferred embodiment. In FIG. 16A , sensor assembly 601 is installed between two teeth 602 , 603 of an end plate 604 of off-going friction element D. Assembly 601 includes a core 605 , a load sensor 606 and a sleeve 607 . Core 605 is preferably made from a metal, such as steel or aluminum, and is securely grounded to a transmission case 608 through anchor bolts 609 . Load sensor 606 is preferably a film-type sensor constructed with a pressure-resistive material. Sensor 606 generates an electrical signal that corresponds to a relative level of loading force 610 . Sleeve 607 , which protects sensor 606 , is preferably made from rubber, plastic or metal. While cover 607 is referred to as either a sleeve or a cover, it is to be understood that the terms are interchangeable. FIG. 16B illustrates an installation of sensor assembly 601 in transmission case 608 . Sensor assembly 601 is securely positioned in a location where a spline tooth is normally located otherwise. When off-going friction element plates are installed, end plate 604 fits snugly around sensor assembly 601 , providing a preload to sensor 606 . That is, sensor 606 preferably indicates non-zero output L 0 even when no load is exerted on off-going friction element D or its end plate 604 . When the torque load is exerted as shown by arrow 610 during a shift event, the output from sensor 601 provides a relative measure of the load on off-going friction element D. When this embodiment is employed to measure relative load exerted onto an off-going friction element such as when torque sensor 130 is used to measure the load on friction element D, it is readily understood that optimal friction element release timing is identified when the sensor output level approaches to L 0 corresponding to zero load level.
FIGS. 17A and 17B depict another sensor assembly 611 which has a similar structure to assembly 601 in FIG. 16A . Assembly 611 includes a grounded core 612 , a force sensor 613 and a sleeve 614 . However, as illustrated in FIG. 17A , assembly 611 is placed against a pin 615 that is fixed to an end plate 616 of off-going friction element D. Sensor 613 is preloaded against pin 615 , providing non-zero output in the absence of torque load on off-going friction element end plate 616 ( FIG. 17B ). When a torque load is exerted on off-going friction element D, pin 615 is pressed with a force 617 against sensor 613 across sleeve 614 . This enables sensor 613 to provide the relative measure of torque load on off-going friction element D. FIG. 17B shows a view of sensor assembly 611 and off-going friction element end plate 616 with pin 615 in a transmission case 618 .
FIG. 18 shows another potential embodiment of this invention wherein a thin film-type force sensor 621 is directly attached to a tooth 622 of a friction element plate 623 , covered with a protective sleeve 624 . Sleeve 624 is preferably made from rubber, plastic or metal. When plate 623 is installed into a transmission case 625 , sensor 621 directly measures contact load 626 between friction element tooth 622 and a spline 627 through sleeve layer 624 , providing a relative measure of the load exerted onto off-going friction element D.
FIG. 19 shows another preferred embodiment of the invention wherein a metal beam 631 , which is securely anchored to a transmission case 632 , is installed and positioned between two teeth 633 , 634 of an off-going friction element plate 635 . As a load level 636 exerted on plate 635 varies, a strain level of beam 631 changes. The level of the strain is detected through a strain sensor 637 , providing a relative measure of is torque load exerted on off-going friction element D. Optionally, a cover may be added to protect strain sensor 637 .
FIGS. 20 , 21 A, 21 B, 21 C, 22 A, 22 B and 23 - 29 show various preferred embodiments of the invention relating to directly measuring torque in a friction element. More specifically, FIG. 20 shows a partial view of a band brake system 700 with a load sensing assembly 731 . Brake system 700 includes an anchor end of a band strap 732 , a pin or a hook 733 , and an anchor bracket 734 . Band strap 732 is preferably either a single-wrap or double-wrap type. Load sensor assembly 731 includes an assembly core 735 , a load sensing unit 736 and a protective sleeve or cover 737 . Assembly core 735 is made of a metal and securely mounted to a transmission case 738 with a bolt 739 or any other means. Cover 737 may be made of metal, rubber, plastic or any other materials. Cover 737 protects sensor unit 736 from direct contact with pin or hook 733 for reduced sensor material wear. Cover 737 may be made of a thermally-insulated material to protect sensor 736 from heat. Cover 737 also acts as a protective shield against any other hostile conditions that include electro-chemical reaction with transmission oil. Load sensing unit 736 , which may be a pressure resistive film-type, is positioned between core 735 and cover 737 . The tip of sensor 736 is positioned against pin 733 across cover 737 . When a band engagement is commanded, strap 732 is pulled by a hydraulic servo (which is described below) in the direction shown with an arrow 740 . Band strap 732 stretches slightly, pushing pin or hook 733 against load sensor 736 . Load sensor 736 generates an electrical signal according to a magnitude of the contact force. That is, sensor 736 provides a relative measure of band tension at the location of pin 733 . The electrical signal is transmitted to a data acquisition unit (not shown) and then to controller 4 through an electrical cable 741 .
FIGS. 21A , 21 B and 21 C depict band strap designs in detail. In FIG. 21A , a band strap 732 has a part punched out and bent to form a pin or a hook 753 and a hole 752 . Hole 752 also acts as an oil drain during band engagement. In FIG. 21B , a small pin or a block 754 is riveted, screwed or welded to strap 732 . Alternatively, a pin or a hook 755 can be formed as a part of an anchor bracket 734 as shown in FIG. 21C . A pin 755 is attached to a band anchor bracket 734 instead of a strap 732 . Sensor assembly 731 is positioned against the pin 755 . Since bracket 732 is stiffer than the strap 732 , its strain is smaller under loaded conditions during both holding and engagement. Thus, a level of force exerted onto a load sensor 736 through a micro displacement of pin 755 is reduced significantly. The lower stress level improves the life of the sensor assembly 731 while enabling the use of a sensor 736 rated for a lower maximum force.
FIG. 22A illustrates sensor functions during a band engagement process. When the engagement is initiated, transmission controller 4 sends an electrical signal I(t) to raise and regulate a hydraulic force 761 applied to a servo piston 762 . As servo piston 762 is stroked, a servo rod 763 pulls one end 764 of band strap 732 . Tension around strap 732 builds up, squeezing out lubrication oil 766 from a band-drum interface. During the engagement, brake torque from strap 732 to a drum 767 is partly transmitted through viscous shear across oil 766 . The brake torque is transmitted through a mechanical frictional force once strap 732 makes physical contact with drum 767 . According to a conventional analysis, the relationships between engagement torque T eng , band tension at a pin F pin 733 and band tension at a servo F servo 769 can be written as follows, assuming a Coulomb friction model as a primary torque transfer mechanism between band strap 732 and drum 767 :
T eng =F servo R ( e μβ −1) Eq. (4)
F pin =F servo e μβ Eq. (5)
where R=drum radius, m=a Coulomb friction coefficient, b=a band wrap angle 770 assuming that pin 733 is positioned sufficiently close to an anchor 734 . Drum 767 rotates in the same direction 772 as the hydraulic force 761 . Substituting Eq. (5) into Eq. (4) yields:
T
eng
=
F
pin
R
(
1
-
ⅇ
-
μβ
)
or
F
pin
=
T
eng
R
(
1
-
ⅇ
-
μβ
)
Eq
.
(
6
)
Since the electrical output signal S pin from the sensor is approximately linear with band tension F pin :
S pin =kF pin Eq. (7)
where k is a proportional constant. Substituting Eq. (7) into Eq. (6) yields:
S pin = k R ( 1 - ⅇ - μβ ) T eng = k ′ T eng or ⅆ S pin ⅆ t = k ′ ⅆ T eng ⅆ t
where Eq . ( 8 ) k ′ = k R ( 1 - ⅇ - μβ ) Eq . ( 9 )
According to Eq. (8), the sensor output S pin provides a relative measure of band brake engagement torque T eng .
This embodiment provides a relative measure of T eng and its derivative (dT eng /dt) that enables a closed loop control of on-coming friction element engagement process during torque phase 32 . It significantly improves band engagement control, mitigating a sudden rise of band brake torque known as “grabbing” behaviors. Alternatively, the sensor signals may be utilized to adaptively optimize open-loop calibration parameters such as a rate of pressure rise as a function of oil temperature in order to achieve a consistent (dT eng /dt). The similar analysis can be applied to the so-called “de-energized” band engagement where the drum spins in the opposite direction of the servo.
FIG. 22B illustrates sensor functions while band strap 732 is securely engaged around drum 767 under a holding condition without any slippage. In this case, the band tension F pin at pin 733 reflects both the level of the band tension F servo 784 at the servo and the level of torque load T load 785 exerted onto band 732 and drum 767 from the adjoining components (not shown). It is important that one should clearly differentiate T load from T eng which is brake torque exerted from the band to the drum under slipping conditions.
According to a conventional analysis, the relationships between F pin , F servo and T load can be algebraically written as:
F pin = F servo + T load R or T load = R ( F pin - F servo ) Eq . ( 10 )
Substituting Eq. (10) into Eq. (7), the sensor output S pin can be described as a function of F servo and T load as:
S pin = kF pin = kF servo + k R T load Eq . ( 11 )
Note that F servo is a function of an electrical signal I commanded to a hydraulic control system from a transmission controller. That is:
F servo =F servo ( I ) Eq. (12)
Substituting Eq. (12) into Eq. (11) results in:
S pin = kF pin = kF servo ( I ) + k R T load Eq . ( 13 )
In the absence of T load , Eq. (13) becomes:
S pin =kF servo ( I )≡ S pin noload ( I ) Eq. (14)
where S pin noload is defined as the sensor output measured under no load condition for a given level of I. In practice S pin noload can be readily obtained, as required, by sweeping the servo actuator with a varying level of I while a vehicle is in a stationary condition. Substituting Eq. (14) into Eq. (13) yields:
S pin - S pin noload ( I ) = k R T load Eq . ( 15 )
Thus, S pin −S pin noload (I) provides a relative measure of torque load T load for a given electrical input I. The optimal timing to release off-going friction element during a synchronous shift is when the load exerted onto off-going friction element or T load becomes zero. This can be readily determined by sampling S pin and evaluating S pin −S pin noload (I) for a given electrical signal I. The use of the load sensor assembly according to this embodiment significantly improves band release controllability during a synchronous shift under all the operating conditions.
FIG. 23 shows a cross-sectional view of another sensor assembly 811 including a cushion element 812 inserted between a load sensor 813 and a pin or a block 814 that is attached to a band strap or an anchor bracket. Cushion element 812 is preferably made of a rubber. Alternatively, cushion element 812 may be made of a metal in the form of a spring such as a disk spring or a conical spring. A protective cover 815 is preferably positioned between cushion element 812 and block 814 . Cover 815 is readily slidable at a nominal force under loaded conditions. The loading force is transmitted from block 814 to load sensor 813 by deformation of cushion element 812 . Accordingly, cushion element stiffness is used to specify a force range at sensor 813 for a given range of loading force at block 814 . The force transmitted to load sensor 813 becomes limited once the cushion element surface becomes flush with surface 817 of the assembly core. This non-linear characteristic indicated at 818 enables high resolution force measurement for a targeted load range 819 as shown in FIG. 24 while protecting sensor 813 from excessive loading.
FIG. 25 shows an alternative embodiment of this invention. In this design, a load sensor 821 is placed at the bottom of a band anchor pin 822 inside a transmission case 823 . Electrical cable 824 attached to sensor 821 is routed outside through case 823 . The tip of pin 822 is inserted into an anchor bracket 826 , which is attached to band strap 825 . When the band brake system is actuated, strap 825 is hydraulically or mechanically tightened around a drum such that anchor bracket 826 pulls pin 822 in the direction of anchor load 828 as represented by an arrow. Accordingly, load sensor 821 directly measures an anchor load 828 exerted onto pin 822 from the anchor bracket 826 . A cushion element 831 is preferably placed between the bottom of an anchor pin 822 and load sensor 821 . Note that the sensing area of sensor 821 is smaller than the surface area of cushion element 831 . The anchor load supported by pin 822 is distributed over the surface of cushion element 831 . Accordingly, only part of the anchor load is transmitted to load sensor 821 . This enables the use of a sensor rated for a lower maximum force.
In FIG. 26 , a strut 841 is inserted between an anchor bracket 826 and an anchor pin 843 . Strut 841 enables the flexible placement of anchor pin 843 with respect to band strap 825 and transmission case 823 . Also, an angle 845 between strut 841 and pin 843 may be adjusted to optimize a level of the axial loading that bracket 876 exerts onto pin 843 through strut 841 . Cushion element 831 and the reduced axial loading allow the use of a sensor 821 rated for a lower maximum force. Alternatively, angle 845 may be adjusted to reduce the side loading onto pin 843 to minimize sensor output hysteresis caused by sticky pin displacement under the loaded conditions.
The embodiment of the invention in FIG. 27 shares many of the same features described in connection with the embodiment in FIG. 26 . First, anchor pin 853 is inserted into an unthreaded hole 852 inside transmission case 823 . Its large head 854 prevents pin 853 from falling through hole 852 . A cushion element 836 and a load sensor 821 are placed against pin head 854 . Cushion element 836 may be made of a rubber and act as a seal to protect the sensor 821 from transmission oil. Behind sensor 821 and cushion element 836 is a sensor support dish 857 , which may be made of a metal. Sensor support dish 857 is backed by a large plug 858 inserted into a threaded hole 859 . The position of plug 858 may be adjusted and locked with a nut 860 in order to set anchor pin 853 to a desirable position with respect to anchor bracket 826 and strut 841 .
The embodiment of the invention shown in FIG. 28 shares features with the embodiment for FIG. 27 . Specifically, a load sensor 821 is placed behind a cushion element 872 inside support dish 874 with a raised retaining wall 873 . Cushion element 872 is preferably made of rubber. Alternatively, cushion element 872 may be made of metal in the form of a spring such as a disk or a conical spring. Under a no load condition, the surface of cushion element 872 is in contact with that of a pin 875 , while the end of retaining wall 873 is away from the surface of pin 875 . When the anchor load is below a predetermined level, the entire load is transmitted to sensor 821 through the elastic deformation of cushion element 872 . As the anchor load increases, cushion element 872 becomes compressed. Once the surface level of cushion element 872 becomes flush with the end of retaining wall 873 , retaining wall 873 starts supporting the load exerted on pin 875 , limiting the load on sensor 821 .
As shown in FIG. 29 , cushion element stiffness determines where the sensor output starts leveling off at 876 . This embodiment of the invention enables the sensor performance to be targeted for a specific load range, maximizing a measurement resolution 877 . In addition, sensor output voltage at limiting load level 876 and at zero load level 878 can be used to auto-calibrate sensor 821 for enabling absolute load measurements. That is when the sensor output reaches its maximum plateau, a transfer function between sensor output voltage and load level can be mapped based on two point calibration. This feature is extremely useful, especially if sensor characteristics drift over time or vary under different operating conditions. This load-limiting feature also protects the sensor from overloading, preventing its failure.
Based on the above, it should be readily apparent that the present invention provides numerous advantages over prior friction element control during a torque phase of gear-ratio changing. The preferred embodiments provide a consistent output shaft torque profile for a powertrain system with a step-ratio automatic transmission system during a synchronous friction element-to-friction element upshift, which reduces shift shock. Also, there is a significant reduction in shift feel variability for a powertrain system with a step-ratio automatic transmission system during a synchronous friction element-to-friction element upshift. The preferred embodiments of the invention permit the use of either absolute or relative load levels which are directly measured or estimated. The use of a relative load profile, instead of absolute load levels, eliminates the need of full-sensor calibration, while the use of a relative load profile only requires one point sensor calibration that corresponds to zero load level and improves robustness against sensor drift over time. The preferred embodiments also provide for reduced output shaft torque oscillation at the beginning of the inertia phase due to the release of the off-going friction element at or near the ideal release timing where its load level is zero or close to zero and robustness against the variability of off-going friction element breakaway friction coefficient by means of a quick release of the off-going friction element at the ideal synchronization timing.
Further advantages include a consistent output shaft torque profile and significant reduction in shift feel variability for a powertrain system with a step-ratio system during a torque phase of a synchronous friction element-to-friction element upshift and during a torque phase of a non-synchronous upshift with an overrunning coupling element. Further, the system provides robustness against the variability of off-going friction element breakaway friction coefficient by means of a quick release of an off-going friction element at an ideal synchronization timing during a synchronous shift and against the variability of a friction element actuation system for both synchronous and non-synchronous shifts.
A clutch load sensor assembly provides a relative measure of torque load exerted to the clutch while it is engaged. A band brake load sensor assembly provides a relative measure of engagement torque (brake torque) and its derivative during an engagement process while a band slips against a drum and a relative measure of torque load exerted onto a band and a drum while the band is securely engaged to the drum without slippage. Sensor output may be calibrated with respect to a command signal to a band servo actuator while torque load is zero. Use of a protective cover in the sensor assembly prevents a direct contact between a load sensing material and the pin for reduced sensor material wear; and shields the sensor from hostile conditions that include heat and electro-chemical interaction, such as with transmission oil.
Although described with reference to preferred embodiments of the invention, it should be understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For example, the invention could be extended to a double-wrap band brake system. In general, the invention is only intended to be limited by the scope of the following claims.
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A load sensor assembly for measuring an amount of torque transmitted through a torque establishing element includes a core mounted on a transmission housing and a load sensor mounted on the core. The load sensor is positioned against a portion of the torque establishing element whereby a portion of the amount of torque transmitted through the torque establishing element travels through the load sensor and is measured. A cable is connected to the load sensor for transmitting a signal representative of the amount of torque to a transmission controller.
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